Additives for Plastics Handbook
2nd Edition
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Additives for Plastics Handbook 2nd Edition
John Murphy
ELSEVIER ADVANCED TECHNOLOGY
UK USA JAPAN
Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK Elsevier Science Inc, 360 Park Avenue South, New York, NY 10010, USA Elsevier Science Japan, Tsunashima Building Annex, 3-20-12 Yushima, Bunkyo-ku, Tokyo 113, Japan Copyright © 2001 Elsevier Science Ltd. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means: electronic, electrostatic, magnetic tape, mechanical, photocopying, recording or otherwise, without permission in writing from the publishers. First edition 1996 Second edition 2001 I S B N l 85617 370 4 Second impression 2003
No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Published by Elsevier Advanced Technology, The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK Tel: +44(0) 1865 843000 Fax:+44(0) 1865 843971 Typeset by Variorum Publishing Ltd, Rugby Printed and bound in Great Britain by Biddies Ltd, www.biddies,co.uk
CONTENTS List of Tables
xvii
List of Figures
xxi
Preface and Publishers' note
xxiii
Chapter 1
An Overview of Additives
1
Chapter 2
Types of Additive and the Main Technical Trends
5
2.1
2.2
2.3 2.4 2.5 Chapter 3
Chapter 4
Current Lines of Development 2.1.1 Fillers 2.1.2 Pigments 2.1.3 Plasticizers 2.1.4 Stabilizers 2.1.5 Flame retardants Special Additives 2.2.1 Antistatic and conductive additives 2.2.2 Food contact and medical additives 2.2.3 Clarifiers, nucleating agents, compatibilizers Multi-functional Formulations Masterbatches Dendritic Polymers
5 6 7 7 8 8 9 9 9 10 10 10 11
The World Market
13
3.1 3.2 3.3 3.4 3.5
13 15 15 16 16
World Consumption of Additives The Market for Masterbatch Overall Commercial Trends Growth of Specialist Compounders Regional Factors
Modifying Specific Properties: Mechanical Properties - Fillers
19
4.1
21 21 21 21 21
Effect of Fillers 4.1.1 Mechanical properties 4.1.2 Thermal properties 4.1.3 Moisture content 4.1.4 Reinforcement mechanism of
fillers
vi
Additives for Plastics Handbook
4.2 4.3
4.4 4.5 4.6
Chapter 5
Factors for Compounding 4.2.1 Aggregation of fillers Types of Fillers 4.3.1 Calcium carbonate Kaolin 4.3.2 Magnesium hydroxide (talc) 4.3.3 4.3.4 WoUastonite Silica 4.3.5 Metal powders 4.3.6 Microspheres 4.3.7 Expandable microspheres 4.3.8 Cellulose fillers 4.3.9 Surface Modification Modification Particle geometry 4.4.1 4.4.2 Coating Nano-technology 4.5.1 Processing nano-composites Commercial Trends
22 23 24
24 26 26 27 27 28 28 29 30 30 30 31 32 32 35
Modifying Specific Properties: Mechanical Properties Reinforcements
5.1 5.2
5.3
5.4 5.5 5.6 5.7
5.8
Fibres: The Basic Properties Types of Reinforcing Fibre 5.2.1 Aramid fibres Carbon or graphite fibres 5.2.2 Glass fibre 5.2.3 5.2.3.1 E-CRglass 5.2.3.2 Other developments 5.2.3.3 Forms of glass fibre 5.2.3.4 Chopped/milled products 5.2.4 Polyester fibre Polyethylene fibre 5.2.5 Hybrid fibres 5.2.6 Other Fibres Asbestos fibre 5.3.1 Boron fibre 5.3.2 Nylon fibre 5.3.3 Natural Fibres Forms of Reinforcement Long-fibre Reinforcement New Developments Polyurethane/long fibres 5.7.1 ABS/long fibres 5.7.2 Shaped fibres 5.7.3 Commercial Trends
37
39 40 40 41 43 45 46 47 47 48 48 49 49 49 49 49 50 51 51 53 54 54 54 55
Contents Chapter 6
Modifying Specific Properties: Appearance - Colorants, Pigments, Dyes, Special Effects
6.1
6.2 6.3 6.4
6.5 6.6 6.7 6.8 6.9 6.10 6.11
6.12 Chapter 7
Main Types ofPigment and Colorant 6.1.1 Mixed metal oxides 6.1.2 Dyes 6.1.3 Liquid colours Addition of Colorants Replacement of Cadmium Pigments for Special Effects 6.4.1 Aluminium pigments 6.4.2 Pearlescents 6.4.3 Light interference pigments 6.4.4 Fluorescents 6.4.5 Thermochromic and photochromic pigments 6.4.5.1 Intelligent' heat protection for food products 6.4.5.2 High-performance dyes for CD manufacture 6.4.5.3 Solar heat Laser Marking Pigment Dispersants Multi-functional Systems Pigments for Engineering Plastics The Effect of Pigments on Dimensions Colorants for Food and Medicals Recent Developments 6.11.1 Colour strength 6.11.2 Weathering 6.11.3 Natural effects 6.11.4 New forms of pigment 6.11.5 Surface treatment 6.11.6 New pigment chemistry Market Trends
Modifying Specific Properties: Appearance - Black and White Pigmentation
7.1
Types of White Pigment 7.1.1 Titanium dioxide 7.1.1.1 Surface treatments 7.1.1.2 Titanium dioxide grades 7.1.1.3 Opacity and tinting strength 7.1.1.4 Colour 7.1.2 Zinc sulphide 7.1.3 Other white pigments and extenders 7.1.3.1 Aluminium silicates 7.1.3.2 Barium sulphate ('blanc fixe')
vii
57
58 58 58 59 60 61 62 63 63 63 64 64 65 65 65 66 66 67 67 68 69 69 69 69 70 70 70 70 71
73
73 73 74 76 76 78 78 80 80 80
viii
Additives for Plastics Handbook
7.2
7.3 7.4 Chapter 8
7.1.3.3 Calcium silicate 7.1.3.4 Magnesium silicate 7.1.4 White masterbatch 7.1.5 New developments Black Pigments 7.2.1 Types of carbon black 7.2.1.1 Thermal oxidative decomposition processes 7.2.1.2 Thermal decomposition processes 7.2.1.3 Effect of particle size and structure on properties of carbon blacks 7.2.1.4 Testing for properties: structure effect and determination 7.2.2 Other black pigments 7.2.3 Black masterbatch 7.2.4 Recent developments Commercial Trends: Titanium Dioxide Commercial Trends: Carbon Black
85 86 86 87 89 90 91 92 92
Modifying Specific Properties: Resistance to Heat - Heat Stabilizers
8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8
8.9 8.10 Chapter 9
80 81 82 82 84 84
How They Work Antioxidants 8.2.1 Primary antioxidants 8.2.2 Secondary antioxidants Blends Replacement of Heavy Metals 8.4.1 Organotins Effect of Silica on the Activity of Stabilizers Benzoxazolone Derivatives for PVC New Chemistry for Stabilizers 8.7.1 Lactone chemistry 8.7.2 Vitamin E Recent Developments 8.8.1 Pipes and fittings 8.8.2 Foamed pipe 8.8.3 Cable insulation 8.8.4 Medical products Other Stabilizers Commercial Trends
Modifying Specific Properties: Resistance to Light - UV Stabilizers
9.1 9.2 9.3 9.4
How They Work UV Screening Pigments Absorbers Energy Transfer Agents/Quenchers
93
93 95 95 96 97 97 98 99 100 100 100 102 103 103 104 104 104 105 105 107
107 108 109 109
Contents
ix
Scavengers: Hindered Amine Light StabiUzers Synergists with HALS Polymeric Stabilizers Blends Replacement of Heavy Metals Selection of Antioxidants for Use with UV Stabilizers Concentrates, Masterbatches New Chemistry Recent Developments
109 110 111 111 111 112 113 113 113
Mod if)^ing Specific Properties: Flammability - Flame Retardants 10.1 How They Work 10.2 Summary of FR additives 10.2.1 Reactive FRs 10.2.2 Additive FRs 10.2.2.1 Inorganics 10.3 Halogenated Compounds 10.3.1 Chlorinated compounds 10.3.2 Brominated compounds 10.4 Other Flame Retardants 10.4.1 Melamine cyanurate (MC) 10.4.2 Zinc borate 10.4.3 Zinc hydroxystannate (ZHS) and zinc stannate (ZS) 10.4.4 Zinc sulphide 10.4.5 Metal hydrates 10.5 Phosphorus 10.6 Intumescent Flame Retardants 10.7 Halogen-free Systems 10.7.1 Wire and cable compounds 10.8 Combinations of Flame Retardants 10.9 Synergistic Reactions 10.10 Health and the Environment 10.11 Recycling 10.12 New Developments 10.13 Nano-composites 10.14 Commercial Trends
115 115 116 118 118 118 120 121 122 123 123 124
9.5 9.6 9.7 9.8 9.9 9.10 9.11 9.12 9.13
Chapter 11 Modifying Specific Properties: Conductivity - Antistatic/Conductive Additives
11.1 11.2 11.3 11.4 11.5 11.6
Classificationof Antistatic Additives Conductive Additives ESD (Electrostatic Discharge) Compounds EMI (Electromagnetic Interference) Compounds Metallic Additives Coated Polymers
125 125 125 126 127 128 129 130 132 135 136 137 138 139
141
143 143 144 144 144 147
X Additives for Plastics Handbook
11.7 11.8 11.9
Intrinsically Conductive Materials Moulded Circuitry Recent Developments
Chapter 12 Modifying Processing Characteristics: Curing and Cross-linking
12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 12.10 12.11 12.12 12.13
The Curing Process Terminology Curing Agents, Accelerators Inhibitors Curing with Accelerators Curing without Accelerators Selecting a Curing System Curing Agents for Epoxy Systems Cure Promoters UV Cure Initiators New Developments Thermoplastics Cross-linking Commercial Trends
Chapter 13 Modifying Processing Characteristics: Couplings Compatibilizing Agents
13.1
New Developments
Chapter 14 Modifying Processing Characteristics: Plasticizers
14.1 14.2
14.3 14.4 14.5 14.6 14.7
The Function of Plasticizers Main Types of Plasticizers 14.2.1 Phthalates 14.2.2 Sebacates and adipates 14.2.3 Fatty acid esters 14.2.4 Oligomeric/polymeric plasticizers 14.2.5 Epoxies Extenders and Secondary Plasticizers Health and Safety of Plasticizers Reducing the Level of Plasticizers Recent Developments Commercial Trends
Chapter 15 Modifying Processing Characteristics: Blowing Agents
15.1 15.2 15.3 15.4
15.5
The Function of Blowing Agents Physical Blowing Agents Chemical Blowing Agents (CBAs) Structural Foams 15.4.1 In-house gas generation 15.4.2 Nucleating agents 15.4.3 Dispersion agents Syntactic Structural Foam
148 148 149 151
151 152 152 153 154 154 155 157 160 160 160 162 164
167
168 169
169 170 170 171 171 172 173 173 173 174 175 175 177
177 178 179 180 181 181 181 181
Contents
15.6
15.7
Replacement of CFCs 15.6.1 Flexible foams 15.6.2 Rigidfoams 15.6.3 Pentane 15.6.4 Expanded polystyrene 15.6.5 Economics of CFC replacement 15.6.6 Testing the insulation value of blowing agents New Developments 15.7.1 Liquid carbon dioxide
Chapter 16 Modifying Processing Characteristics: Modifiers and Processing Aids
16.1
Impact Modification 16.1.1 Impact modifiers for PVC 16.1.1.1 MBS modifiers 16.1.1.2 ABS modifiers 16.1.1.3 Acrylic modifiers 16.2 Elastomer Modification 16.2.1 Acrylic rubber 16.2.2 Styrenics 16.2.3 Polyolefins 16.2.4 Polybutene 16.3 Dimer Acids 16.4 Calcium Carbonate 16.5 Modification of CPEE Polymers 16.6 Modification of PMMA with Silicon and Phosphorus 16.7 Impact Modifiers for Thermosetting Resins 16.8 Processing Aids 16.8.1 Low-temperature flexibility 16.9 Clarifying/Nucleating Agents 16.10 Fluoropolymers 16.11 New Developments 16.11.1 Core-shell rubbers 16.11.2 Silicones 16.11.3 Modification of engineering thermoplastics Chapter 17 Modifying Processing Characteristics: Lubricants^ Mould Release Agents, Anti-slip and Anti-blocking
17.1 17.2
Lubricants for Performance Improvement Lubricants as Processing Aids 17.2.1 Metallic stearates 17.2.2 Hydrocarbons 17.2.3 Fatty acid amides and esters 17.2.5 Polyolefin waxes 17.2.6 Polyamides 17.2.7 Fluoropolymers
xi
182 183 183 184 185 186 186 186 187
189
189 190 190 190 191 192 193 193 194 195 195 196 196 197 197 198 200 200 202 203 203 204 204
205
205 206
207 207 208 210 210 211
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Additives for Plastics Handbook
17.3 17.4 17.5 17.6
17.2.8 Silicones 17.2.9 Boron nitride Combination and Modification Release Agents for Thermosets Anti-blocking, Anti-slip Additives New Developments
Chapter 18 Other Types of Additive: Miscellaneous Additives
18.1
Anti-bacterials and Biocides 18.1.1 Anti-allergy agent 18.2 Degradation Additives 18.3 Shrinkage Modifiers, Low-profile Additives 18.4 Improved Barrier Properties 18.4.1 Gas barrier coating 18.4.2 Resorcinol additives 18.4.3 Plasma technology 18.4.4 Oxygen absorption in food packaging 18.5 Hard Coatings 18.6 Thermal Insulation 18.7 Fragrance 18.8 PVC Matting Agent 18.9 Anti-fogging 18.10 Acoustic Insulation 18.11 Surfactants, Foam Control Additives 18.12 Mould Treatment Agents Chapter 19 Other Types of Additive: Additives for Rubber
19.1 19.2
Guidance on Safety New Developments 19.2.1 Silica
Chapter 20 Other Types of Additive: Additives for Recycling
20.1 20.2 20.3 20.4 20.5 20.6 20.7 20.8
Stabilizing, Re-stabilizing Stabilizers Improvement of Properties 20.3.1 Fibres/compatibilizers/impact modifiers Desiccants PE/PVC Compatibilizing Melt Flow/Viscosity Modification Additives for Identification of Plastics Equipment for Recycling
212 213 213 214 216 216 219
219 221 221 222 222 223 223 224 224 225 22 5 226 226 226 227 228 229 231
233 233 233 237
23 7 238 239 239 239 240 240 241 244
Chapter 21 Background Information: Equipment - Mixings Compounding^ and Dosing
21.1 21.2
Incorporation of Additives Mixing Thermosets
245
245 246
Contents
21.3
21.4 21.5
Mixing Thermoplastics 21.3.1 Drymixers 21.3.2 Calendering 21.3.3 Extrusion compounding 21.3.4 Compounding mineral fillers 21.3.5 Fine talc masterbatch 21.3.6 Single- and twin-screw extruders 21.3.7 Adjustable screw geometry Colour Dosing Recent Developments
Chapter 22 Background Information: Health and Safety
22.1
22.2
22.3
22.4
22.5 22.6
Hazards by Additive 22.1.1 Carbon black 22.1.2 Titanium dioxide 22.1.3 Flame retardants 22.1.4 Glassflbre 22.1.5 Styrene monomer 22.1.6 Isocyanates Hazards During Production, Storage, and Transportation (Workers) 22.2.1 Fire/explosion 22.2.2 Emissions 22.2.3 Skin/body contact 22.2.4 Dust Hazards During Use (Direct Consumer and General Public) 22.3.1 Toxicity-food contact 22.3.2 Flame retardants 22.3.3 Plasticizers Hazards During Disposal (Workers and General Public) 22.4.1 Landfill-heavy metals 22.4.2 Incineration HealthandSafety at the Workplace: Some Guidelines 22.5.1 Reduction ofemissions at the workplace New Developments: Solvents
Chapter 23 Background Information: Legislation and Testing
23.1 23.2 23.3 23.4 23.5 23.6
xiii
247 247 248 248 249 249 250 251 252 253 257
257 257 258 259 259 2 59 260 260 261 261 261 262 262 263 263 264 266 266 267 267 268 268 269
Blowing Agents 269 Flame Retardants 269 23.2.1 Halogenated and brominated flame retardants 2 71 Heavy Metals/Cadmium Pigments 2 71 Plasticizers 2 72 Food Packaging 2 73 Migration Levels 2 74
xiv
Additives for Plastics Handbook
23.7
Moves to Establish a Threshold of Regulatory Concern (TRC) 23.7.1 US history 23.7.2 European history 23.8 The User's Viewpoint 23.9 Medical Products and Packaging 23.10 Waste and Recycling 23.10.1 Packaging 23.10.2 Electrical and electronics 23.10.3 Automobiles 23.11 Physical Testing 23.11.1 Mechanical tests 23.11.1.1 Tensile strength and modulus 23.11.1.2 Flexural strength and modulus (ISO 178 and ISO 3597) 23.11.1.3 Compressive strength (ISO 3604) 23.11.1.4 Shear strength 23.11.1.5 Impact strength 23.11.2 Thermal testing 23.11.2.1 Heat stability 23.11.2.2 Light stability 2 3.11.3 Electrical properties 23.11.3.1 Surface and volume resistivity 2 3.11.3.2 Surface resistivity 23.11.3.3 Electrostatic discharge 23.11.3.4 Static decay 23.11.4 Flammability 23.11.5 Heatrelease 23.11.6 Ease of ignition 23.11.6.1 Calorificvalue: ISO 1 7 1 6 calorific value of materials 23.11.6.2 Flamespread 23.11.7 Smoketests 23.11.7.1 AS 1530: Part 3 - t e s t for early fire hazard properties of materials 23.11.7.2 DIN 4102 Part 1 - B l Brandschacht test 23.11.7.3 VDE 0472 Part 804 23.11.7.4 FAR Part 2 5: Federal Aviation Regulations for materials used in aircraft 23.11.8 Fire tests for building materials 23.11.9 Combustibility 23.11.10 Floor covering
2 76 276 2 76 2 77 2 77 277 278 2 78 279 279 280 280 280 280 281 281 282 282 283 283 283 283 284 284 284 286 286 286 286 287 288 288 288 288 288 289 290
Contents
23.11.11 New developments 23.11.12 Analysis 23.11.13 Surface quality tests 23.11.13.1 Barcol hardness test 23.11.13.2 Acetone sensitivity 23.11.13.3 Surface analysis 23.11.14 Colour testing 23.11.14.1 Colour stability Database Appendix A: Conversion Tables Appendix B
xv
292 292 292 292 293 293 293 294 294 295 299
Technical Terms Standards and Testing Institutions Recommended Books and Journals Manufacturers'handbooks Journals covering additives for plastics and rubber
299 302 303 303 304
Appendix C: Standard Abbreviations for Plastics and Elastomers
307
Appendix D: Trade Names
311
Appendix E: Directories
327
Directory of Suppliers Industry Associations and Federations
32 7 3 64
Fillers and extenders Reinforcements, fibrous and microspheres Pigments, colorants, whites, blacks Antioxidants and stabilizers: heat and light Flame retardants Antistatics and conductive additives Curing, cross-linking agents Property modifiers, processing aids Plasticizers Blowing Agents, Dispersants, Miscellaneous Additives Lubricants, release agents, slip/anti-block
369 386 392 399 405 414 417 420 423 428 430
Data Sheets
369
Editorial Index
445
Index of Advertisers
471
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LIST OF TABLES Table 1.1 Table 1.2 Table 1.3 Table 3.1 Table 3.2 Table 3.3 Table 4.1 Table 4.2 Table 4.3 Table 4.4 Table 4.5 Table 4.6
Table Table Table Table
5.1 5.2 5.3 5.4
Table 5.5 Table 5.6 Table 5.7
Types and uses of additives The main effect of additives on the properties of a compound Main types of additive for plastics, and their functions World production and consumption of major thermoplastics, 1 9 9 9 - 2 0 0 5 (thousand tonnes) Regional production and consumption of thermoplastics, 1 9 9 9 - 2 0 0 5 (% of total) Recent mergers and takeovers in the additives sector, 1 9 9 7 - 2 0 0 0 At a glance: fillers Common fillers and reinforcements for plastics Some properties of silica particles and the amounts of added silanes for surface treatment Properties of a nano-composite P A6 compound, compared with conventional reinforcement Polypropylene nano-composite made by a slurry process compared with conventional compounds Physical properties of nano-tubes in polycarbonate At a glance: fibre reinforcements A quick guide to the relative properties of fibres Comparison of commonly used reinforcing fibres Typical properties of continuous pitch-based carbon fibres (based on BP Amoco Thornel grades) Typical properties of continuous P AN-based carbon fibres (based on BP Amoco Thornel grades) Main properties of glass fibre Glass fibre: comparison of E-and E-CR glass
14 17 17 19 20 17 33
34 35
37 39 40 42 42 44 45
xviii
Additives for Plastics Handbook
Table 5.8 Table 5.9 Table 5.10 Table 5.11 Table 5.12 Table 6.1 Table 6.2 Table 6.3 Table 7.1 Table 7.2 Table 7.3 Table 7.4 Table Table Table Table
7.5 7.6 7.7 7.8
Table 7.9 Table 7.10 Table Table Table Table Table
7.11 8.1 8.2 8.3 8.4
Table 8.5 Table 8.6 Table 8.7 Table 9.1 Table 9.2
Long fibre-reinforced thermoplastics: effect of fibre length 52 Properties of typical long-fibre thermoplastic compounds 53 Long-fibre plastics compared with die-cast metals (2 3°C) 53 Cost comparison between glass fibre and carbon fibre, specific mechanical properties (glass cost = 1.00) 56 Capacities for carbon fibre, worldwide, 56 1 9 9 6 - 2 0 0 0 (tonnes) At a glance: pigments, dyes, special effects 58 Replacements for cadmium pigment master62 batches Influence of pigment type on dimensional plates 68 At a glance: white pigments 73 Melt flow index of polycarbonate, pigmented with 5% Ti02 showing the effect of various surface treatments 75 Comparison of the hardness of pigments 78 Zinc sulphide compared with titanium dioxide for glass-reinforced thermoplastics 79 Properties of white pigments and fillers 81 82 Typical grades of white masterbatch 84 At a glance: black pigments Effects of changing particle size or structure on 86 specific peoperties of carbon black Effects of changing both particle size and structure on specific peoperties of carbon black H7 Variations in carbon black produced by different processes 89 Typical grades of black masterbatch (universal) 90 93 At a glance: heat stabilizers 95 Polymer heat stabilizers: selection guide Stabilizer systems in different PVC applications 99 Extrusion compound for window profiles; comparison between a classical lead formulation and tin maleate (Thermolite 410) 99 Flexible PUR foam scorch evaluation: delta E after microwave test 101 Effect of the structure of HAS on the colour strength of a compound 102 World consumption of stabilizers (thousand 106 tonnes) 107 At a glance: UV stabilizers 112 UV stabilizers: selection guide
List of Tables xix
Table 9.3 Table 10.1 Table 10.2 Table 10.3 Table 10.4 Table 10.5 Table 10.6 Table 10.7 Table 10.8 Table 10.9 Table 10.10 Table 10.11 Table Table Table Table
10.12 10.13 10.14 10.15
Table 11.1 Table 11.2 Table 11.3 Table Table Table Table
11.4 12.1 12.2 12.3
Table Table Table Table
12.4 12.5 12.6 12.7
Table 12.8 Table Table Table Table
13.1 14.1 14.2 15.1
Typical UV stabilizing systems in masterbatch form At a glance: flame retardants Summary of the main FR additives Eff'ectofchlorinatedFR additives on PE and PP compounds Effect of varying ratios of chlorine and bromine on ABS compounds Effectofindividualfillers (UL 94 test ofPP) Influence of intumescent gel coats on fire behaviour of composites (RTM process) Examples of halogen-free flame-retardant grades (M A Hanna Group) General wire and cable specifications to meet BS7211 Effect of a mineral filler/melamine combination with PP on LOT and UL 94 tests FR formulations using various synergists Halogen compounds found effective with antimony oxide Flame retardants: selection guide Cost and properties of flame-retarded PP ConsumptionofFRsby major region ConsumptionofFRsby type and region, 1998 (thousand tonnes) At a glance: anti-static/conductive additives Classification of electrical insulation/ conductivity Performance of stainless steel fibres at various loadings Comparison ofdifferent conductive systems At a glance: curing systems Applications of organic peroxides Cross-linking with peroxides: dosage of peroxide per 100 parts polymer Curing systems and when/where to use them Curing agents for epoxy resins General specifications for BS7211 Advantages and disadvantages of available cross-linking methods Use of radiation-cured products in the USA, 1 9 8 9 - 2 0 0 3 (tonnes) At a glance: coupling, compatibilizing agents At a glance: plasticizers Main types of plasticizers At a glance: blowing agents
113 115 116 121 123 126 12 7 128 129 131 132 134 135 138 139 139 141 142 147 147 151 152 153 155 161 163 164 165 168 169 170 177
XX Additives for Plastics Handbook
Table 15.2 Table 15.3 Table 15.4 Table 16.1 Table Table Table Table
16.2 16.3 16.4 16.5
Table 16.6 Table 17.1 Table 17.2 Table 17.3 Table 17.4 Table 18.1 Table 19.1 Table 20.1 Table 20.2 Table 22.1 Table 23.1 Table 23.2 Table 23.3 Table 23.4 Table 23.5 Table 23.6 Table 23.7 Table 23.8
Blowing gases for plastics Typical processing temperatures for thermoplastics Replacement of blowing gases for expanded polystyrene At a glance: process modifiers and processing aids A quick guide to impact modifiers Kraton G as a compatibilizer Typical processing aids Clarified polypropylene compared with other transparent packaging materials Eff'ectsofPPA-l onprocessability ofHDPE resins (capillary rheometry 190°C) Typical lubricants for various thermoplastics Characteristics of acrylic processing aids Effect of an internal lubricant on injection moulding of electrical housing and cap Typical high-slip and anti-blocking masterbatches Acoustic properties of some commonly used materials Additives used in rubber compounding At a glance: additives for recycling Forms of waste, processing lines and potential recycled products Typesof additives and their potential hazards Summary of relevant environmental legislation German BGA limit values for migration of elements from raw materials (DIN 53 7 70) Permissible migration in toys (European Norm EN 71-3) A guide to food-contact additives Tests designed mainly for rigid materials Tests designed mainly for flexible materials UL 94 requirements EC classification of fire tests for construction products
178 180 186 189 191 194 199 202 203 205 209 210 215 228 2 32 2 37 243 2 58
2 70 2 74 274 2 75 285 285 287 291
LIST OF FIGURES Figure 2.1
Figure 2.2
Figure 4.1. Figure 5.1.
Figure 6.1.
Figure 7.1.
Figure 11.1.
Figure 11.2. Figure 16.1.
Acting like a plastic 'sponge', Accurel is one of the new systems for introducing additives homogeneously to a granular compound. (Photograph: Akzo Nobel) 6 Many types of additives, such as stabilizers, are now supplied in forms that are easier and safer to handle and use. (Photograph: Akcros Chemicals) 8 A typical compounding line for reinforced thermoplastics. (Illustration: FTP Co) 22 Polypropylene is reinforced with chemically coupled glass fibre for injection moulding this Whirlpool washing machine tub, giving high performance for low cost. (Photograph: Ticona) 38 Structures of inorganic pigments: (top) rutile-cassiterite structure of inorganic colour pigments and (bottom) the spinel structure. (Illustration: Ferro Corporation) 59 Diagram of carbon black molecules illustrates how the size and structure influence the processing and properties. (Illustration: Cabot Corporation) 85 Carbon black additives can also conduct electricity, offering a simple and effective means of providing anti-static properties or EMI shielding. (Photograph: Cabot Corporation) 145 Carbon black particles. (Photograph: Cabot Corporation) 146 A new dimension for polypropylene is signalled by the development of clarifying agents, such as Millad. (Photograph: Milliken Chemical) 201
xxii
Additives for Plastics Handbook
Figure 17.1.
Figure 21.1.
Figure 21.2.
Figure 21.3.
With an average particle diameter of 4.5 /xm, Tospearl is an advanced silicone anti-blocking agent. (Photograph: GE Silicones) 217 For better compounding efficiency, recent barrier screw designs by Davis-Standard include (top) DSB-V, with variable-pitch barrier flight, and DSB-V I, with a dual-barrier design and variable lead barrier flight. (Photograph: Davis-Standard) 2 52 Powerful shearing and homogenizing of sensitive materials, retaining vital rheological properties, is provided by Farrel Corporation's Advex. (Photograph: Farrel Corporation) 2 53 Looking towards a new market demand, the Davis-Standard Woodtruder combines in a single system the latest plastics extrusion technology with technology for processing wood fibre. (Photograph: Davis-Standard) 2 54
Preface Both technically and economically, additives form a large and increasingly significant part of the polymer industry, both plastics and elastomers. In the five years since the first edition of this handbook, there have been wide-ranging developments, covering the chemistry and formulation of new and more efficient additive systems and the safer use of additives, both by processors in the factory and, in the wider field, as they affect the general public. It has also become clear that, to meet today's requirements, the budgets for research and development and the structure needed to maintain a global presence are beyond the resources of individual companies, resulting in many mergers and takeovers, leading to the creation of a few world-scale giant producers, complemented by a number of specialists. This second edition follows the successful formula of the first, presenting a comprehensive view of all types of additives, concentrating mainly on their technical aspects (chemistry/formulation, structure, function, main applications) with notes on the commercial background of each. Whereas reports concentrate on only one sector (such as pigments or 'performance' additives), in this handbook we have again expanded the field to include any substance that is added to a polymer to improve its use, so including reinforcing materials (such as glass fibre), and carbon black and titanium dioxide. As with the first edition, this information is again presented in a more 'userfriendly' form, starting from the information requirement of the user, and so classifying additives by the properties that they offer and the appUcations in which they are used. To avoid excessive cross-referencing, there may be some repetition, but it is hoped that the advantages of this form of presentation will outweigh any disadvantage. JSM, June 2001 Publishers' note Sadly, just before completion of this book the author, John Murphy, passed away. Elsevier Advanced Technology has endeavoured to complete this work to John's very high standards. We hope that Additives for Plastics Handbook will live up to John's expectations and prove to be an invaluable aid.
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Adding value to polymers
Slip & Antiblocking Fatty Acid Amides Amides Concentrates
Antistatic Fatty Amine Ethoxylates Fatty Amide Ethoxylates Glycerolmonosteatate Sodium Alkane Sulphonate Concentrates High Purity
Electroconductive Black Non-Aromatic
Flame Retardant Processing Aids
1U_ AKZO NOBEL
www.poiymerchemicals.com
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CHAPTER 1 An Overview of Additives From the very beginnings of the plastics industry, it has been necessary to add materials to a basic polymer resin in order, at least, to make it processable. It has also been clear that additive materials are necessary to modify a resin, to improve properties that are desirable, and to eliminate or mitigate properties that are undesirable. In developing additive systems, the plastics industry has learnt much from the earlier experience of the rubber industry, but the pace of development responding to market needs has produced research in completely new fields, developing additive systems using new chemistry. While the plastics industry is a major user of additives, it is not the only one. Additives overall can be classified as follows:
Table 1.1 Types and uses of additives Type
Main applications
Additives
Products, normally used in small quantities, which enhance the value of materials such as plastics, paints, colour prints, and lubricants, by improving their processability, performance, and appearance during manufacture and in use.
Antimicrobials
Substances that prevent the growth of microbes and give consumer products such as soaps and toothpastes a medicated property.
Coatings
The broad term for paints, inks, and lacquers. While often associated with decoration, coatings also protect surfaces from corrosion and damage.
Colours
Can be soluble dyes for textiles, leather, paper, or insoluble pigments for plastics, coatings, and printing inks.
Fine chemicals
Highly complex functional intermediates or ingredients for 'high-tech' applications; for example, in the pharmaceutical, agrochemical, and electronic industries.
Heat and light stabilizers
Additives that prevent the degradation of plastics and coatings under the effects of heat, oxygen, and light.
Optical brighteners
Chemicals which impart whiteness to textiles, detergents, paper, fibres, and plastics.
2
An Additives for Plastics Handbook
Type
Main applications
Photo/repro additives
Additives that, when irradiated with light, promote the hardening of printing inks, coatings, and adhesives, and chemically fix images used in electronic or graphic materials.
Pigments
Colorants that remain undissolved before, during, and after application: they are used to colour plastics, inks, paints, and synthetic fibres.
UV curing
Hardening of coatings and adhesives by means of ultraviolet light.
Water treatments
Help purify water for industrial and domestic applications. They also modify water as an agent for the processing of minerals and oils, and have a variety of properties to process water (for example, flocculants separate water from solid particles).
Source: Ciba Specialty Chemicals
For plastics, the range of additives is very large, involving the improvement of many properties:
Table 1.2 The main effect of additives on the properties of a compound
Physical properties Thermal conductivity Heat deflection temperature Abrasion resistance Impact strength Tensile strength Flexural strength Compressive strength Dielectric constant Processing Exotherm Thixotropy Machinability Cost reduction Key: - decreases; ++ increases; = essentially no effect.
Calcium carbonate, calcium silicate. powdered aluminium. or copper
Chopped Mica, Alumina, flint powder. glass silica. carborundum. powdered or flaked silica, molybdenum glass disulphide
Metallic Colloidal fillers or silica, alumina bentonite clay
++ ++
++ ++
++ ++
++ ++
++ ++
=
= -
++
-
-
++
++ ++ ++ ++ ++ ++
++
= = =
++
= = =
++
= = = =
-
=
= -
=
-
++
=
++
-
++
++
-
++ ++ ++
An Overview of Additives
3
Table 1.3 Main types of additive for plastics^ and their functions Type
Examples
Functions
Fillers and mineral reinforcements
Calcium carbonate, talc, mica
Adding bulk to a compound: increasingly used to improve stiffness, surface hardness
Fibre reinforcements
Aramid, carbon, glass, natural fibres
Mechanical strength: used as short fibre, long fibre, spheres
Colorants
Pigments, liquid colours, colour pastes, dyestuffs, special effects
Virtually unlimited, added as powders or liquids: easier mixing, replacement of heavy metals
Black and white pigments
Carbon black, titanium dioxide
Also for improved UV resistance and (carbon black) electrical conductivity
Heat resistance
Antioxidants and stabilizers
Act to delay/prevent oxidation of polymer under heat, during processing or application
UV resistance
UV stabilizers
Delay/prevent oxidation of end-product under prolonged exposure to sunlight
Flame retardants
Reactive, additive, other systems
Prevent ignition of polymer, promote extinguishing: types not producing smoke or fumes
Antistatics, conductives
Antistatic/conductive additives
Increase electrical conductivity, to prevent electrostatic discharge, sticking/clinging (e.g. films)
Curing systems for thermosets
Accelerators, curing agents, and catalysts
Initiate and control the cure of thermosetting resins
Cross-linking, coupling, compatibilizing
Forming cross-links between suitable polymer and other molecules
Cross-linking agents for thermoplastics; coupling agents, compatibilizers to promote bonds between polymers and additives
Plasticizers
Mainly phthalates, but many systems are used
Improvement in processability, flexibility: used mainly in PVC, but limited use in other plastics
Process modifiers, processing aids
Lubricants and plasticizers, nucleating agents
Improvement of mixing/blending; control of viscosity
Blowing agents
Inert gas or gas-forming chemicals injected or mixed into a compound to react during processing
Production of foams and expanded plastics; replacement of chlorofluorocarbons (CFCs)
Lubricants
Lubricants, mould release agents, slip and anti-block
Improvement in processing; release properties; reduced slippage and blocking with films
Other types
Barrier properties, shrinkage, acoustics, surfactants, antimicrobials
Giving specific properties
RecycUng additives
Impact modifiers, stabilizers
Used to improve/protect properties of waste plastics during mechanical recycling
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CHAPTER 2 Types of Additive and the Main Technical Trends Additives are becoming more technical, doing more work, offering greater value, and so commanding a higher price. PVC is still by far the largest user, in volume terms, but polyolefins have emerged as a growing second-runner and the development of engineering plastics has opened up a fast-growing market for speciality additives, ranging from flame retardants to stabilizers, pigments, and processing aids that will resist the higher processing and service temperatures involved. These naturally impose more critical performance requirements. Many additives have more than one effect on a plastics compound. Plasticizers will often aid in processing and lubrication. Light stabilizers also have an effect of weathering. Carbon black, which is widely used as a pigment, also functions as a light shield, as an electrically conductive component, and as a reinforcement.
2.1 Current Lines of Development
A main line of development now is multi-functional additives, such as reinforcing fillers: talc is added to polypropylene to improve stiffness and heat stability, pigments can aid in UV protection, plasticizers also function as lubricants and anti-static agents. A potentially fertile field is that of synergism between components, where better performance in vital properties such as weathering and flammability can be achieved by using lower concentrations of synergistic additives. The aim, all along, is to simplify operations at the compounding or processing level and to remove the need for precision weighing and metering of very small amounts. Delivery of additives in a more convenient and safer form is also high on priority lists. This obviously calls for significant research and development budgets and capital expenditure in more sophisticated production/processing plants, which has the effect of raising the entry cost all the time for new producers. A further cost pressure is the necessity of complying with legislation, often worldwide - and to be able to provide customers right down the line with documentation to prove compliance. There is also active development of surface-modification technology, to render fillers of all types (especially inexpensive mineral fillers) more acceptable
6
Additives for Plastics Handbook
Figure 2.1. Acting like a plastic 'sponge', Accurel is one of the new systems for introducing additives homogeneously to a granular compound. (Photograph: Akzo Nohel)
to the matrix and improve interfacial bonding, for better, more durable mechanical properties. A third major line of development is to meet increasingly strict regulations for health and safety, both in the workplace and in public use. This particularly affects flame retardants (where concern has been expressed about possible escape of flame-retardant components during storage, under heat and flame, and in recycling) and pigments (where legislation has centred on the use of heavy metals in pigment formulations, possibly creating hazards in disposal of the product). 2.7.7 Fillers
Filler technology is shaping an entirely new and 'active' role for these very traditional materials, especially using coating and other surface treatments to confer other properties, such as pigmentation and processing assistance. Expandable fillers continue to be promising. Calcium carbonate is the most important filler, in terms of volume, but is relatively low in value. In the plastics industry, it has mainly been used in PVC compounds, but 'engineered' grades (produced by adjusting particle size or geometry, and/or modifying the surface) are opening up a large potential market in polyolefins, where the aim is not to extend the bulk of the compound but to offer positive properties, such as reducing cycle time and improving physical properties. For example, very fine particles give marked increases in the
Types of Additive and the Main Technical Trends
7
strength of films. Stearic acid-coated grades give good mechanical properties and improved processing. Suitable calcium carbonates can be used in part replacement of white pigment and to achieve high gloss (and to offset the reduction in gloss produced by replacement of lead stabilizers with calcium/zinc systems). Other mineral fillers are coming into prominence, as users demand more and more of compounds. Talc, mica, and wollastonite improve stiffness, heat stability, and expansion/shrinkage, and certain clays in sub-micrometre particle sizes (nano-particles) are currently the focus of research, to improve mechanical and also barrier properties, for very small percentage loadings. A new area of development is to incorporate the filler permanently into the polymer matrix, by use of coupling reactions. This can increase impact strength and thermal properties of polyamides and modify the anisotropy of partially crystalline plastics, such as polyamides and polyesters. In polypropylene, bonding with kaolin can also improve scratch resistance, which is a useful benefit for automobile interior applications. Surface modification of fillers such as silica, mica, and wollastonite allows these to penetrate markets that were formerly the province of reinforcements such as carbon black and glass fibre. 2.7.2 Pigments
Regulations are still the key problem, as manufacturers strive to come up with effective pigments that also meet the heavy metal-free legislation. High concentrations are also important, to save costs, but there is also fast-growing interest in pigments to produce special effects, such as pearlescence and edgeglow, and also strong interest in systems for laser marking. The main trend is still the development of alternatives to classic pigments based on heavy metals, such as cadmium. While, ironically, voices are now being raised questioning whether cadmium pigments are really such a danger to the environment, new pigment systems are being commercialized that can effectively replace them and give brilliance that is comparable. Colorants in liquid form are another area of study, to give processors the flexibility of changing colours within a production run, and pigments that give novel effects (such as metallics, pearlescents, and 'flip-flop' colour changes) are increasing in popularity. 2.7.3 Plasticizers
While the plasticizers sector (which is almost totally bound up with PVC) has been dominated in recent years by controversy over the use of phthalates, there has been significant development in systems based on other materials, such as polymeric plasticizers. Lubricants and processing aids also come into this classification, where the trend is towards adaptation to other plastics compounds, both standard and engineering plastics, and new systems that reduce or overcome migration, for use especially in food contact and medical/ healthcare applications.
8
Additives for Plastics Handbook
Figure 2.2 Many types of additives, such as stabilizers, are now supplied informs that are easier and safer to handle and use. (Photograph: Akcros Chemicals)
2.1.4 Stabilizers
Stabilization (against both heat and light) is a main object of development, using new chemistry and fulfilling new market niches. Stabilizers are increasingly needed in engineering plastics, to stabilize the compound during processing at higher temperatures and/or to provide stability for the application during continued exposure to elevated temperatures and/or outdoor conditions. In this direction, the development of hindered amine light stabilizers (HALS) has been the most significant achievement, and there is also considerable research into the synergistic effects of employing two stabilizer systems in a compound. Replacement of heavy metal formulations is influencing all development, and the introduction of cadmium/zinc systems in a more effective form is significant. Classically, stabilizers have used lead compounds and, on environmental grounds, manufacturers have volunteered to reduce levels to about 60% of today's usage by 2010. Calcium/zinc systems are now not included in the European Commission Ust of heavy-metal stabilizers, and these are seen as a key material for the future. 2.7.5 Flame retardants
Flame retardants are probably the most researched group of additives today, to meet performance requirements under increasingly tight environmental conditions (which now also include behaviour during disposal of products by incineration). Recent development has been aimed especially at systems also
Types of Additive and the Main Technical Trends
9
offering zero or very low emission of smoke and fumes when exposed to the heat of combustion. There is continuing controversy over the use of halogenated flame-retardant systems, and a general move towards non-halogenated/zero smoke types (especially among European legislators). The critical end products involved are housings for consumer and office electronics equipment, wire and cable sheathing, and (as a result of recent tragedies) electrical equipment and rolling stock used for railways. There is a move (also in Europe) to limit or prevent the use of flame retardants based on brominated systems, on the grounds of alleged difficulty in recycling, but this is being strongly opposed by the industry (and there is disagreement also among legislators). A consequence of the need for investment in research and development will be the rationalization of the number of types on the market, and the emergence of a limited number of grades (possibly with fewer manufacturers).
2.2 Special Additives
In terms of functions, the emphasis is now on improvement of film processing, anti-static additives, 'special effect' pigments, multi-functional fillers, and stabilizing systems for engineering plastics. Many of the new developments in individual additives are now being offered at the same time in safe, convenient technical masterbatch formulations. 2.2.7 Antistatic and conductive
additives
Conductive additives such as high-purity carbon blacks are commonly added to compounds where there is a potential hazard from electrostatic discharge. There is also extensive development of systems based on metal fibres, to give higher protection or shielding against electromechanical interference. 2.2.2 Food contact and medical
additives
Special purity requirements naturally have to be met for the many types of additives used for applications in contact with foodstuffs (such as packaging) and for medical products. For many years, world authorities have operated a degree of control over the use of additives in critical applications such as food contact and medical products. A review of the relevant legislation is given in Chapter 2 3 . In the USA, the relevant authority is the Food and Drug Administration (which also exerts considerable influence over products worldwide). In Europe, the European Union (EU) is the legislative authority. In July 2000 it ratified an EU directive on food contact, listing additives in food-contact plastics that will require migration testing. Production of compounds for use in the medical sector has become an attractive (if very demanding) 'niche' for highly qualified specialists, able to operate globally, with strong financial resources.
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Additives for Plastics Handbook
2.2.3 Clarifiers, nucleating agents,
compatibilizers
Clarifiers and nucleating agents are making considerable progress, especially in polypropylene compounds, where they improve the clarity of the compound while assisting processability and set-up. The advantages show themselves particularly in medical products and packaging. Compatibilizers are increasingly used to aid the more effective use of other additives.
2.3 Multi-functional Formulations
There is a marked trend towards multi-functional formulations (sometimes based on upgraded fillers or pigments) and single-pack formulations, such as for PVC. The aim, all along, is to simplify operations at the compounding or processing level and to remove the need for precision weighing and metering of very small amounts. Delivery of additives in a more convenient and safer form is also high on priority lists. This obviously calls for significant research and development budgets and capital expenditure on more sophisticated production/ processing plants, which has the effect of raising the entry cost all the time for new producers. A further cost pressure is the necessity to comply with legislation - often worldwide - and to be able to provide customers right down the line with documentation to prove compliance.
2.4 Masterbatches
Most resins can be coloured by masterbatch or colour concentrate, or modified with an increasing range of special additive concentrates, at dosing rates of 0 . 5 10%, but usually around 2%. The use of self-colouring, however, is growing again, with the availability of more reliable and cheaper dosing equipment, with greatest growth being in gravimetric systems. Apart from the technical advantages, including reduction/rationalization of inventory, masterbatch has economic advantages, it is claimed. Specialist Hanna notes that the cost of pre-colouration can generally be taken as about the same as that of compounding, which is about 0.2 7-0.3 kg"^. Masterbatch at 7.5 kg~^, dosed at 2% to colour a natural resin costing 0.90 kg~^ produces a cost of 0.13 kg~^. Adding the cost of the dosing equipment adds about 0.015 kg"^ to the total. Most major suppliers now offer masterbatches containing special additive formulations. A typical range is that produced by Chrostiki. It includes Mastertint black, white, colour, and special effect, Masterad slip, anti-static, and cleaning agent. Filolen masterbatch offers calcium carbonate with very high softness and dispersion, giving very high whiteness and high purity. Addition levels range from 2 to 5% for polypropylene woven tapes and big bags, to 5-20% for polyolefin injection mouldings, and 20-50% for biaxially oriented polypropylene film, thermoforming and pipe, sheet, and profiles.
Types of Additive and the Main Technical Trends
11
2.5 Dendritic Polymers
DSM has commercialized new dendritic (highly branched) polymers, under the name Hybrane. Related to the original dendrimer, Astramol, these performance additives are described as 'hyperbranched'. They do not require such a perfect structure as a dendrimer, but they generally retain many of the properties characteristic of these materials. They can assume a globular-like structure, leading to low melt viscosity because there is little entanglement between the molecules. The globular molecules can also act as hosts for small *guest' molecules. Interesting results can be obtained by combining different functional groups on the same polymer. For example, one type of end-group can give compatibility with the matrix while another can provide surface-active effects or facilitate take-up of other molecules. DSM sees potential applications in plastics as rheology modifiers and compatibilizers, and, in the wider field, in adhesives, toners, detergents, and cross-linkers. Hybrane additives have also been studied for dyeing polypropylene fibres. When used as compatibilizers, they can form links with other additives such as fillers, flame retardants, stabilizers, anti-statics, and fungicides. They can take up 2 0 - 2 5% of their own weight in water (compared with the maximum 10% of which linear polymers are capable) and can easily be modified by the addition of other functional groups, including groups to regulate the migrating power of the additive in the compound during processing, possibly producing an enrichment of additive at the surface.
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CHAPTER 3 The World Market Additives form a growing and valuable sector of speciality chemicals that has been selected by a number of manufacturers as a business sector. It is difficult to give an accurate estimate of the world market for additives for polymers, because the figure depends very much on what is defined as an 'additive'. There are as many different estimates as there are forecasters. Most tend to limit the field to the so-called 'performance' additives - such as plasticizers, lubricants, stabilizers, flame retardants, and anti-statics - that confer a specific property or protection on the compound. This excludes fillers and pigments, but increasingly significant portions of these are now also developed and marketed as 'performance' fillers or pigments, special carbon blacks, or titanium dioxides. So it is not surprising that there is some difference in estimates, arising to some extent from such overlaps. As well as regular market forces, other forces acting on the additives market include environmental and health issues, new technologies, inter-material competition, strategic repositioning for increased shareholder value, and customer-driven factors.
3.1 World Consumption of Additives
While the volume of additives worldwide increased by 6% from 1996 to 1998, value actually fell, by 1%, due to the Asian crisis. Trying to find some common ground between the best forecasts, it appears that the world additives market amounts to about 7.8 million tonnes, valued at about US$16 billion and is growing overall at about 3.5-4% per year. Fillers account for an estimated 50% by volume but in value they make up only 15% - and here Ues the stimulus for much current development. Asia Pacific is the largest global user of additives, accounting for some 35% of demand, by value. North America and Europe are about equal, at 28 and 25%, respectively, while the rest of the world takes up the remaining 12%. There have been dramatic changes in the additives market. The research agency Townsend considers that the world market for performance additives (flame retardants, stabilizers, anti-oxidants, modifiers, and lubricants) today
14
Additives for Plastics Handbook
amounts to about 2.72 million tonnes, worth nearly US$16 billion. Flame retardants make up 3 1 % of the volume (nearly 850 000 tonnes) and stabilizers, modifiers, and lubricants each account for around 16-17% (about 430 000 to 460 000 tonnes). There is some agreement, however, over flame retardants, where forecasting agencies estimated the world market in 1996 at about 850 000 tonnes with a value of some US$2 billion, and the Western European sector in 1995 at 316 000 tonnes. Additives with a significant value have a smaller volume, and so the next largest segment is probably plasticizers, which are estimated to account for 1 million tonnes in Europe alone, worth US$1.8 billion. Next are pigments and colorants, which might account for around 2 million tonnes worldwide - but it is unclear whether this figure includes titanium dioxide and carbon black (Rapra estimates the European colorants market at 728 000 tonnes, worth US$1.2 billion).
Table 3.1 World production and consumption (thousand tonnes)
of major thermoplastics, Consumpti on
Production 1999 Polypropylene PVC Polyethylene, high density Polyethylene, low density Polystyrene Polyethylene, linear low density ABS Total
27 26 20 16 10 12
1999-2005
2005
Growth rate(%)
1999
2005
Growth rate(%)
870 188 889 121 668 033
39 924 31 821 29 160 18 147 13 307 18881
6.17 3.30 6.71 1.99 3.75 7.79
2 7 608 25 538 21075 16538 10 596 11 302
40 098 32 008 29 229 18 304 13 339 18829
6.42 3.83 5.60 1.70 3.91 8.88
3966 117735
5227 156467
4.71 4.85
3940 116597
5230 157037
4.83 5.09
Source: Enichem/ParpineUi
In terms of additive type, the best estimates suggest that, in volume terms, performance additives break down as: 69% modifiers (including plasticizers), 23% polymer extenders, and 8% process additives. In sales value, modifiers represent 51%, polymer extenders 41%, and processing aids 8%. By polymer matrix, PVC compounds account for 73% of additives by volume. Polyolefins make up 10% and styrenics 5%, while the other polymers make up the remaining 12%. In value terms, PVC drops to 59%, while polyolefins rise to 17%. Styrenics account for 7% and other polymers increase their share to 17%. This sharp difference in volume and value is a key factor in the technical development in the industry, where the trend is to upgrade performance, introducing new technology and, where possible, to simplify use of presentation with the development of multi-functional additives in a safe, more convenient form.
The World Market
15
3.2 The Market for Masterbatch
An important market for additives is in masterbatch - concentrated formulations that offer the processor a convenient means of handling additives, particularly pigments, by 'diluting' with natural material beside or actually in the processing machine. They also offer advantages in inventory size and raw materials storage space. The international compounding group Ampacet estimates that worldwide consumption of masterbatch will reach 2.15 million tonnes in 2 0 0 1 . This is a somewhat higher estimate than that given by market researchers Applied Market Information, probably due to different product classifications. Both, however, agree that the mature markets in North America, Europe, and Japan are currently consuming about 76% of the world total, and Ampacet forecasts that this share will fall to 73% in 2 0 0 1 , as demand rises in Southeast Asia and Latin America. Film (blown and cast), blow moulding, and injection moulding make up about 70% of consumption. About 56% of the total polymer consumption in masterbatch is polyolefins, estimates Ampacet, with polyethylenes making up 41.14 million tonnes and polypropylenes 24 million tonnes. Ampacet identifies the main world market trends in masterbatch as: (i) more customers are expanding worldwide; (ii) masterbatch growth is slowing in North America and Europe; and a two-tier industry will continue to evolve.
3.3 Overall Commercial Trends
The number of small suppliers is decreasing. Recent years have seen companies building and exchanging their portfolios and global giants emerging, such as Ciba Specialty Chemicals (US$5.5 billion turnover), Clariant (US$5.23 biUion), W R Grace (US$3.7 billion), Morton (US$3.33 billion), and Great Lakes (US$2.5 billion). Looking at the pattern of recent takeovers and share exchanges (see table blow), three clear trends can be identified: •
•
Globalization. Following the key end-users (especially in automobiles, electronics, medicals, and packaging) as they set up manufacturing worldwide, to be able to deliver exactly the same formulation, anywhere. This has been a feature of many recent mergers and partnerships, and also of new investment (such as in carbon black, by Columbian). Redefinition of core business and identification of key sectors, to concentrate on new technology and product development. Great Lakes has identified flame retardants as a core sector and is now looking to improve its position in stabilizers; DuPont, Millennium, and KerrMcgee have decided to stay in titanium dioxide, purchasing the assets of ICI and Bayer; and Elf Atochem has identified hydrogen peroxides as a core business. A global position in phosphates (partly as a source for flame retardants)
16
Additives for Plastics Handbook
•
was also the aim of the mergers and takeovers involving FMC, Solutia, and Rhodia. Cost of new product development. Driven by competitive pressures, patent expirations, environmental regulations, and the opportunities presented by the growth of metallocene-catalyzed polyolefins and engineering resins, companies appear to be adopting a ^horizontal' approach (to concentrate on specific industries, meeting specific regulatory requirements) as well as the Vertical' approach (concentrating on specific materials and chemistries).
All in all, the additives business in recent years has emerged as a major global segment of value-added speciality chemistry.
3.4 Growth of Specialist Compounders
A significant trend in the industry is the emergence of a number of companies, usually compounders, which have identified specific product areas. A typical specialist producer is AlphaGary (itself recently taken over), which identified medical compounds as one of its key business sectors. The company claims to be the leading North American and European supplier of performance compounds, specializing in compounds for disposable medical components, as well as closures and seals, and data transmission cables. A comprehensive range of engineering plastics for medical applications has been developed by the US specialist Boedeker Plastics. Aimed particularly at equipment components and housings, it ranges from polystyrene and ABS to polycarbonate and polysulphones, meeting USP and FDA requirements. Another specialist in high-specification moulding compounds is RTF, which has commercialized a series of speciality compounds based on alloys of polycarbonate and poly(methyl methacrylate), offering greater impact strength than polycarbonate alone while maintaining the ease of processing associated with acrylics (including food-contact grades). Coded RTF 1800A Series, it incorporates selected additives such as flame retardants, EMI shielding, permanent anti-static protection, anti-wear additives, and colouring.
3.5 Regional Factors
The rate of growth of plastics consumption varies in different parts of the world, and a lesson that Western producers have had to learn in recent years is that the focus of growth is shifting away from them and towards Asia and Latin America and there is no evidence that the recent financial crises have done anything more than to delay that growth. The highest rates of growth are expected in all areas of Asia, and also in the Middle East and Africa. The world market divides roughly into four even segments, each of about 1 8 0 0 - 2 0 0 0 tonnes (US$3.7 billion-4 billion): the USA and North America, Europe, Japan, and the Asia/Facific region.
The World Market
17
Naturally, the size of each segment is directly related to the production and particularly the consumption of plastics. The relative growth of the Asia/Pacific area, both as a producer and consumer of plastics, will have a significant effect on additives, and it lies behind the number of mergers and takeovers that are occurring in the additives sector. This is clearly driving producers of fillers and additives to follow the polymer producers and adopt a more 'global' outlook, by direct investment in other regions, or by forming partnerships and alliances with local producers in other regions. This has been a key factor behind much of the recent restructuring in the industry. Table 3.2 Regional production and consumption of thermoplastics, 1999-2005 (% of total) Consumpt ion
Production 1999
2005
1999
Growth rate
2005
(%) Western Europe Eastern Europe CIS USA Canada Latin America Middle East Africa Japan Eastern Asia'' Asia/Pacific'' Total
Growth rate
(%)
24.35
23.09
3.57
24.18
21.26
3.22
2.54 1.58 24.85 2.86 5.69 3.79 1.16 8.44 16.84 7.90 100
2.57 1.75 23.09 2.65 6.61 5.36 1.37 6.82 19.25 9.48 100
5.03 6.64 3.57 3.53 7.48 11.48 7.96 1.19 7.21 8.08 4.85
2.21 1.58 24.16 2.16 7.08 1.98 2.41 7.12 18.69 7.77 100
2.27 1.53 21.26 2.00 7.52 2.24 2.46 6.62 22.52 10.17 100
5.52 4.58 2.87 3.76 6.18 7.31 5.44 3.81 7.46 9.90 5.09
'' China, Hong Kong, Korea, and Taiwan. ^Australia, Bangladesh, India, Indonesia, Malaysia, and New Zealand. Source: Enichem/Parpinelli
Table 3.3 Recent mergers and takeovers in the additives sector, 1997-2000^ Date
Purchaser
Product/division
Seller
January 1997 January 1997 January 1997 March 1997 June 1997 June 1997 November 1997 December 1997 February 1998 April 1998 March 1998 March 1998 October 1998
Joint venture Hoechst DSM Melamine Ciba Speciality Clariant ICI Great Lakes Anzon Millennium Ciba Merger Kerr-McGee Elementis Rheox Columbian
Additives Organic pigments Flame retardants Additives Red phosphorus Speciality chemicals Flame retardants Titanium dioxide 100% Carbon black/plastics Titanium dioxide Rheological additives Carbon black
Clariant (Sandoz)/Hoechst Cookson DSM/DSM Chemie Linz Merger Ciba/Sandoz Albright and Wilson Unilever Cookson R-P Thann et Mulhouse Allied Colloids Degussa/Hiils Bayer NL Industries Copebras SA
18
Additives for Plastics Handbook
Date
Purchaser
Product/division
Seller
November 1998 July 1998
Akzo Ciba/Witco
Elementis Witco/Ciba
July 1998 July 1998 November 1998 March 1999 March 1999 April 1999 May 1999 May 1999 June 1999 June 1999
Millennium Elf Atochem Cabot Columbian Rohm and Haas Imetal Huntsman Rhodia Great Lakes Merger
June 1999 July 1999
Ampacet Merger
50% share in Akcros Heat stabilizers/epoxies Titanium dioxide Hydrogen peroxide Aventis aerogels Carbon black Additives Calcium carbonate Titanium dioxide Flame retardants Flame retardants Phosphorus chemicals Concentrates Additives, polymers
November 1999 December 1999 March 2()()() March 2()()()
Joint venture Rohm Velsicol Albemarle
Speciality peroxides PVC processing aids Sodium benzoate Flame retardants
" This is not necessarily a comprehensive list. Source: Additives for Polymers
Titanio do Brazil Air Liquide 50% share Hoechst Korea Kumho Petro 100% Morton 100% ECC ICI Tioxide 100% Albright and Wilson FMC Corp FMC/Solutia Equistar Crompton + Knowles/Witco Akzo/Coin Chem, Taiwan Degussa/Bayer DCV Inc Ferro
CHAPTER 4 Modifying Specific Properties: Mechanical Properties — Fillers Fillers have been used by the plastics industry since its inception. It was the discovery that wood flour made it possible to mould the liquid resin phenol formaldehyde that effectively launched the industry at the beginning of the twentieth century, and subsequently PVC has proved a major user of fillers. In the intervening years, however, the use of fillers for plastics has changed significantly. While the original, basic low-performance materials such as clays and chalks are still used very widely, the modern market is placing increasing pressure on manufacturers to offer fillers that give some additional value, such as improvement in mechanical properties. They are increasingly called upon to provide other value-added functions, such as mechanical properties, UV or heat stability, thermal or electrical conductivity, dimensional stability, or flame retardancy. Increased interest in environmental aspects is creating demand now for fillers that are based on vegetable materials such as cellulose. The potential offered by a filler is determined essentially by its chemistry, and especially by its physical aspects, such as the size and geometry, surface area, and surface energy of its particles. Nevertheless, the weight of the filler remains important. Some fillers (such as barytes) are especially selected for their heavy weight, giving the compound an improvement in acoustic-deadening properties. There is also considerable interest also in fillers that are lightweight, such as hollow particles, usually ceramic or glass microspheres.
Table 4.1 At a glance: fillers Function
The basic purpose is to 'fill' a compound (increase bulk at low cost). To do this the mix must be homogeneous, with good filler/polymer adhesion, and the filler also begins to improve mechanical properties. Most particulate fillers have a higher specific gravity than polymers, but some have been developed that can reduce the weight of the compound. Geometry and surface texture fundamentally influence adhesion properties: these can be improved by surface treatment.
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Additives for Plastics Handbook
Properties affected
Stiffness, hardness, shrinkage/dimensional stability; thermal stability and flame retardancy may also be improved.
Materials/characteristics
Clays, calcium carbonates, talc, silicates. Pigments such as titanium dioxide and carbon black may also have a reinforcing effect. Glass or ceramic microspheres can also offer good properties.
Disadvantages
Compounding may present problems, but surface treatments and dispersing agents will help. Solid mineral fillers add to weight.
New developments
Improved surface treatments for better dispersability, multi-functions, lightweight fillers; nano-composites.
Table 4.2 Common fillers and reinforcements for plastics Type
Characteristics/main applications
Alumina trihydrate
Extender; serving as flame retardant and smoke suppressant
Barium sulphate
Filler and white pigment; increases specific gravity, frictional resistance, chemical resistance
Boron fibres
High tensile strength and compressive load-bearing; expensive
Calcium carbonate
Most widely used extender/pigment or filler for plastics
Calcium sulphate
Extender; also enhances physical properties, increases impact, tensile, and compressive strengths Filler; used as pigment and anti-static agent, or as an aid in cross-linking; electrically conductive
Carbon black Carbon/graphite fibres
Reinforcement: high modulus and strength; low density, coefficient of expansion, coefficient of friction; conductive
Feldspar, nepheline syenite Speciality filler; easily wetted and dispersed; gives transparency/translucency; resistant to chemicals and weathering Glass fibre
Largest volume reinforcement: giving high strength, dimensional stability, heat resistance, chemical resistance
Kaolin
Second-largest extender/pigment by volume: mainly used in wire and cable, PVC flooring, SMC/BMC
Metal fillers, filaments
Electrical and/or thermal conductivity or magnetic properties; reduce friction: expensive
Mica
Flake-form reinforcement: improves dielectric, thermal, and mechanical properties; low in cost
Microspheres (hollow)
Reduced weight; improved stiffness and impact resistance
Microspheres (solid)
Improved flow properties and stress distribution
Organic fillers
Extenders/fillers (wood flour, nutshell, corncobs, rice, peanut hulls)
Polymeric fillers
Reinforcement; Ughtweight
Silica
Filler/extender/reinforcement; makes more thixotropic, aiding plate-out in PVC; acts as flatting agent
Talc
Filler/extender/reinforcement: improves stiffness, tensile strength, resistance to creep Improves strength, reduces moisture absorption, higher heat/dimensional stability, improved electrical properties; high loadings possible
Wollastonite
Source: Based on Plastic Compounding Redbook
Modifying Specific Properties: Mechanical Properties - Fillers
21
4.1 Effect of Fillers 4.7.7 Mechanical
properties
Impact strength and flexural modulus are the mechanical properties that can most be improved by careful selection of mineral fillers, and the shape of the particle is important. Fibre-like woUastonite particularly improves the flexural modulus while cube-shaped calcium carbonate can improve both impact strength and modulus. Talc offers many options because it is capable of many different modifications and surface treatments. The high aspect ratio of glass fibres means that they can provide the greatest improvement in mechanical properties. 4.7.2 Thermal
properties
Fillers usually have a thermal conductivity about 20 times higher than plastics, and the specific heat is about 50%. By improving the heat transfer in the melt, the use of a filler may therefore give a faster set-up when moulding, and so improve the cycle time. In applications, the same effect may be useful in engineering components, improving heat dissipation and/or producing a thermal expansion closer to that of metal. 4.7.3 Moisture
content
Water-soluble compounds in the filler (such as sodium or potassium salts) may be affected by outdoor exposure, so damaging the performance of the compound. For example, an outdoor application with a calcium carbonate-filled compound may have its outer layer converted to calcium sulphide and then to calcium sulphate (gypsum) by the effect of sulphur dioxide in the air. Fortunately, gypsum is virtually insoluble in water and cannot be washed out. However, in products with a high percentage of dolomite, the magnesium carbonate eventually combines with sulphur dioxide to form water-soluble magnesium sulphate, producing efflorescence. 4.7.4 Reinforcennent mechanism of fillers
Reinforcement depends on two features: the number of interactions at the interface between polymer and filler (which is mainly controlled by the low primary particle size in conjunction with the surface activity) and the hydrodynamic effects of particle aggregation and agglomeration (which are linked with shear modulus and hysteresis during dynamic or static deformation). One key is the shape and size of the primary aggregates, which are largely dependent on the manufacturing process, but the distribution of the particles is also important, which is largely controlled by processing conditions. This is particularly true in the case of elastomeric matrices. Recent thinking is that the differences in the aggregate size distributions are particularly responsible for the processing and vulcanization characteristics of the compound.
22
Additives for Plastics Handbook
Methods currently used to determine this require the filler to be comminuted by means of ultrasound - but this causes severe degradation of the agglomerates in carbon blacks, and also distorts the distribution of silicas. An alternative method has been developed using transmission electronic microscopy, in which the filler morphology retained is similar to that obtained in the incorporation process. Anisometry and fractal dimension are also used as parameters for characterizing fillers, the former to predict various mechanical properties of filled compounds and vulcanizates and the latter to investigate the surface structure. Anisometry, which is always subject to distribution, is found to widen with the fillers investigated, with an increase in the dimensions of the objects detected.
4.2 Factors for Compounding
Modern compounding, especially for technical or 'engineering' plastics, may require the addition of a complex range of materials, each with its own characteristics. The sequence in which these are introduced into the compounder (and the position down the screw) is fundamentally important. Fillers, with their weight and volume, are usually brought in first, but the latest technology, in which polymerization or cross-linking takes place in the extruder, may alter the sequence. When compounding there may often be an adhesion problem between a nonpolar polymer matrix and a filler, so it is essential to obtain perfect 'wetting' of the particles by the matrix. Before it can do anything, a filler has to bond effectively with the polymer matrix. The size and geometry of the filler particles influence
Glass fibres
Granulator
RTP pellets
Figure 4.1. A typical compounding line for reinforced thermoplastics. (Illustration: FTP Co)
Modifying Specific Properties: Mechanical Properties - Fillers
23
the ease with which it can be compounded and the bond strength with the other components. Surface energy influences the polymer/filler interaction, and hence the mechanical properties, particularly of polar plastics. The surface energy of fillers (stated in mj m~^) is not measurable directly. High surface energies produce dispersion problems, reducing mechanical properties, but surface energy may be improved to some extent by surface coating. To assist in obtaining a good dispersion of filler/reinforcement in a compound, it may be useful to employ a dispersing agent (see Chapter 17). Typical are phosphoric esters of fatty alcohols, used to improve dispersion of alkaline fillers and pigments in thermoplastics, including polyolefins, polystyrenes, and plastisols. The additive can be introduced before the filler is added or can be premixed with the filler. In polypropylene, it is claimed that calcium carbonate loadings can be increased to 70% without significant change in mechanical properties, while Charpy impact strength is improved by better dispersion. An aggregate of calcium carbonate with a multiple surface coating (such as Omyalene G200) allows calcium carbonate to be added directly to thermoplastics during processing. The granulated product can be mixed easily with the thermoplastic and fed directly into the machine. Redispersion is very good. It can be used with all thermoplastics, and in all processes. Dosing ranges from 2 to 15% by weight for film to 10-50% for cables, sheeting, and profiles. Abrasion can be serious when using mineral fillers. Fillers with alpha-quartz components have by far the highest abrasion rate, but heavy and tabular spars and dolomite also show high abrasion compared with some calcium carbonates. The measurement value usually cited is the Mohs hardness scale, but this is not a decisive indicator. 4.2.1 Aggregation
of fillers
A continuing problem with particulate fillers is that they often will not flow smoothly, but tend to aggregate, leading to irregular distribution of the particles in a compound, with attendant processing problems, poor surface quality, and reduction in mechanical properties. Research has shown that aggregation is determined by the relative magnitude of attractive and separating forces, the most important factors influencing the homogeneity of polymer composites being the size of the particles, their surface tension, and the shear forces acting on them during homogenization. The extent of aggregation is always determined by the relative magnitude of the forces attracting and separating. In polymer composites, the most important attractive force is adhesion, while hydrodynamic forces (such as shear) lead to separation of particles. The size and surface tension of the particles strongly influence aggregation. Although the specific surface area tends to give a good indication of the aggregation tendency of a filler, the particle size distribution is more important, since individual particles tend to interact with each other. The results obtained also indicate that the properties of the powder and the suspension may yield valuable indirect information about aggregation. The
24
Additives for Plastics Handbook
extent of aggregation may be reduced by non-reactive surface treatment and increased shear.
4.3 Types of Fillers 43.1 Calcium
carbonate
In terms of weight, calcium carbonate is the most important filler for plastics and it is also widely used in rubber and paints. Calcium carbonate is, in fact, much more than 'chalk' (as it is universally described in the plastics industry). The term covers natural chalk, limestone, and marble - and also precipitated calcium carbonate, which has a very fine particle size, is relatively expensive, and offers some interesting properties in polymer compounds. The natural deposits in various parts of the world have large differences in chemical purity making each suited to specific applications. The material is generally very well suited to additional surface treatment and this, together with closer control over particle size and distribution, has given most producers a range of grades serving as functional additives rather than mere fillers. Calcium carbonate is still a long way from the end of its potential. In plastics, it is used mainly in PVC, both flexible and rigid. Coarser particles are mainly used, but as compound specifications become more exacting fine-particle stearic acidcoated grades are used for better mechanical and processing properties. Being white, these grades can also aid in pigmentation and can also assist gloss, including compensating for loss of gloss where lead stabilizers have been replaced by calcium/zinc systems. It is also an important component of polypropylene, alone or with talc, for rigidity and whiteness that resists weathering. Metalloceneproduced polypropylenes, with greater self-reinforcement, can tolerate higher loadings, for better whiteness. Unsaturated polyesters, such as bulk and sheet moulding compounds, make extensive use of calcium carbonate. Polymer-coated calcium carbonates based on Carrara marble and aluminium hydroxide, with pigment integrated into the coating, have been developed to overcome the problem of irregular distribution of pigments in highly engineered polyesters, such as shrink-free formulations. The latest products offer a high concentrate of 90% CaC03/10% polyolefin binder (compared with 60-70%, which is usually regarded as the limit) in pellet form, so that moulders and extruders can add the mineral direct, with good dispersion. In the mix, the mineral also acts as a heat conductor, so aiding processing and reducing the cycle time. Applications include bottles, household articles, caps and closures, and industrial packaging. For polyolefin films, grades in powder or pellet form comprise very fine particles, averaging 1 jiim in diameter, with narrow particle size distribution and surface coated with a substance compatible with organic compounds. At loadings of 60% or higher there are increases in film strength that are described as 'dramatic'. Among recent developments are grades claiming 10-40% improvement in moulding productivity as a result of faster cooling. Electrical grades for
Modifying Specific Properties: Mechanical Properties - Fillers
25
thermosetting electrical insulation offer good electrical and mechanical properties, including very high operating temperatures, including calcined clay giving cost-effective performance in rubber extrusions and low-voltage cable and wire insulation. Recent modified grades of calcium carbonate (from ECC International) include an ultrafine stearate-coated grade made from pure Italian marble, giving high whiteness in rigid PVCs and optimization of the cost-performance of titanium dioxide. Special types of calcium carbonate include: • fine calcined clays: produced from highly refined china clays, and have excellent optical properties; • treated with vinyl functional silane: for use with peroxide and other free radical cross-linking systems; designed for very high-voltage EP rubber cable insulation; • treated with vinyl functional silane and a coupling agent: eliminating surface acidity; designed as an inert carrier for organic peroxides in wire/ cable applications; silane treatment gives cable insulation high electrical stability in water; • coated with aminosilane coupling agent (also used as an opacifying extender for matt emulsion paints). High-whiteness calcium carbonate (derived from pure Italian marble) comes in various grades: • • •
Milled below 45 |im: exceptional whiteness, controlled particle size, good matting characteristics; for PVC plastisols, emulsion paints, and unsaturated polyesters; Milled below 30 }im: good dispersion, low oil absorption; for PVC cables, PVC plastisols, masterbatches, DMC/BMC, acrylic sealants, and paints; Milled below 10 )im: uncoated/coated with stearic acid; high gloss, toughne ss/rigidity in thermoplastics; for uPVC extrusions, plasticized PVC cables and extrusions, polypropylene mouldings, masterbatch, and silicone sealants.
Calcites come in various forms: • • •
Microcrystalline: good colour with extremely fine particle size and amorphous shape; for PVC compounds, rubber, and high-quality paints; crystalline, surface modified with stearic acid: spherical shape, low binder demand, capable of high loadings in PVC compounds; crystalline: surface modified with calcium stearate; functional performance in compounds, capable of high loadings; for PVC and uPVC calendered sheet, injection mouldings, and polyethylene cable sheathing.
26
Additives for Plastics Handbook
Chalk whitings are used as general purpose extenders. High-quality china clays provide low-cost fillers: • •
predispersed china clays; with alkaline pH, dispersing readily in aqueous media without the need for deflocculant addition; various particle sizes and brightness; highly refined china clays; ultrafine particle size and brightness.
Ball clays. These are secondary clays, processed to reduce the level of coarse particles to a minimum. They are low-cost, semi-reinforcing clays for use where colour is not important. 432
Kaolin
Kaolin was produced 150 million years ago. Its main content is kaolinite, occurring with other silicates such as mica, feldspar, and quartz or metallic oxides such as hematite and rutile. In form it consists of thin pseudo-hexagonal lamellar particles. When heated to above 500°C, kaohnite loses its water of crystallization and changes to metakaolinite, which is stable up to 960°C. Kaolin has an increasing number of uses in plastics, often related to its coupling characteristics. It is used for anti-blocking in polyethylene and PET films and as an infra-red absorber in agricultural film. This also offers the use of this additive for laser marking of moulded packaging. In PVC cables, metakaolinite can increase resistance by removing harmful ions from the matrix. Hydroxyl groups on the surface of calcined kaoUn can also participate in coupling reactions, increasing impact strength and heat resistance of polyamides. Anisotropy can also be adjusted in partially crystalline plastics, with or without glass fibre. New kaolins give excellent tensile and tear strength, and abrasion resistance in general purpose compounds where colour is not a critical factor. They also offer the processability and particle shape advantages of kaolin, and can be used as a partial replacement for carbon black, where they give good cost effectiveness. There are also grades that can partially replace carbon black, improve the flow properties of glass-reinforced nylon, reinforce tyres, and significantly improve air retention. They can also produce 'low-profile' mouldings with good colouration, zero shrinkage, and high gloss, add flame retardancy, produce a matt finish and scuff resistance, or prevent blocking in films. 433
Magnesium hydroxide
(talc)
Hydrated magnesium silicate has a lamellar structure of thin sheets of magnesium hydroxide sandwiched between layers of silica. In plastics (especially polypropylene) it gives a good balance of rigidity and impact strength. Advanced milling technology is used to obtain the finest talcs without reducing the reinforcing power of the lamellar structure. High purity gives very good longterm thermal stability, making compounds good for use in packaging (including
Modifying Specific Properties: Mechanical Properties - Fillers
27
odour-sensitive food-contact applications). With whiteness and low yellow index, talc-filled compounds are easier to colour, with a reduced pigment requirement. Some grades will also reduce shrinkage and warpage in larger mouldings. 43.4 Wollastonite WoUastonite is the subject of much development today, as a potential replacement of calcined clay and other minerals used in thermoplastics and engineered resins, and also on health grounds. New grades under development will have a higher aspect ratio in the smaller particle size ranges, where the mineral can provide increased flexural modulus and flexural strength, with improvement also in heat distortion temperature and dimensional stability. Work on high-aspect-ratio grades also demonstrates improved resistance (compared with talc) to scratching and marring, maintenance of flexural modulus, improved cold and room temperature impact strength, and reduced stress cracking at knit lines. 43.5 Silica When a particulate filler is introduced into a ductile polymer compound, the yield stress is normally decreased but, where the filler is a silica and is treated with a coupling agent it can in fact improve the yield stress. Untreated silicas in PVC compounds show a decrease in yield stress with increasing particle content and size, which is higher when the filler particles are irregular in shape than when the compounds are filled with particles of spherical shape. To improve the adhesion at the particle/matrix interfaces, treatment with a silane coupling agent (y-aminopropyl methyldiethoxysilane) increases the yield stress generally, and more so with irregular shaped than spherical particles.
Table 4.3 Some properties of silica particles and the amounts of added silanes for surface treatment Shape
Mean particle size ()im)
Specific surface area(gm"^)
Added APDES^^ (phr^)
Added HMOS"^ (phr^)
Irregular Irregular Irregular Irregular Spherical Spherical Spherical Spherical Spherical Spherical
5 11 17 27 2 6 11 17 30 51
7.8 3.0 1.9 1.2 10.9 6.2 3.0 2.1 1.5 0.9
1.91 0.73 0.46 0.29 2.67 1.52 0.73 0.51 0.37 0.22
0.26 0.10 0.06 0.04 0.37 0.21 0.10 0.07 0.05 0.03
^ y-Aminopropyl methyldiethoxysilane. ^ Hexamethyl disilazane. ^ Parts per hundred filler by weight. Source: Polymers and Polymer Composites
28
Additives for Plastics Handbook
The use of ultrafine silica as a reinforcement for the treads of tyres has come into prominence in recent years because, as well as offering better resistance to wet skidding than does carbon black reinforcement, it also gives better low-loss properties to the tread compound, with consequent improvement in resistance to rolling and therefore a reduction in fuel consumption. Silica resembles carbon black in its particle morphology, but the surface properties are very different (see Chapter 19). 4.3.6 Metal
powders
Metal powders for highly dense plastics compounds have been developed by Ametek Specialty Metal Products, USA. Stainless steel alloys can be used in lock hardware, appliance parts, and exhaust system components. A 50:50 mixture of irregular stainless steel powder and PTFE gives parts with cross direction elongation of 200-240%, 69065 Shore D hardness, and a bulk density of 6 0 0 1000 g 1~^. The recommended moulding pressure is 500 kg cm~^ and maximum sintering temperature is 3 75°C. 4.3.7
Microspheres
Microscopic solid glass spheres added to a plastics compound give smoothness, hardness, and excellent chemical resistance, with low oil absorption. The spheres can be used with both thermoplastic and thermosetting resins, lowering the viscosity of most resin mix systems - in fact, acting as miniature 'ball bearings' to improve flow. They have the appearance of a fine white odourless powder, in diameter ranges up to 850 jim. The precise geometry of the spheres allows even dispersion, close packing, and easy wetting out, for high filler loadings that add significantly to the dimensional stability of finished products, by reducing shrinkage and improving flatness. Specially formulated coupling agents are incorporated in coatings on the spheres for optimum performance in specific resin systems. High loadings can also increase flexural modulus, abrasion resistance, and surface hardness, and also improve stress distribution. In thermoplastic compounds, solid glass spheres can be added to most materials and used in most processes. The advantages can be summarized as:
Smooth spherical shape
- 'ball bearing'-like action improves flow in difficult mouldings - improvement in processability in fibre-reinforced compounds: better loading capacity, dispersion, and flow, improved stress distribution - up to 60% improvement in cycle time (in some cases) - low, uniform shrinkage; low warpage; close tolerances - even distribution in the resin matrix - improvement in surface finish - improved distribution of stress - reduction in wear on equipment, compared with angular fillers - very low resin absorption
Modifying Specific Properties: Mechanical Properties - Fillers High crush strength
- easily processed in injection moulding machine or extruder - virtually no breakage, even in high-shear mixing - reduction in deformation under load
Chemically inert
- no health hazard during use - can be used in most compounds
Chemically resistant
- can be used in harsh environments
Hardness
- improved abrasion resistance
Temperature resistant
- low coefficient of thermal expansion - high thermal resistance
29
- resistant to most chemicals
Hollow glass spheres will displace the same volume of resin as solid spheres, but are lighter in weight: the typical density is 1.1 g cm~^ (where most mineral fillers have a density of 2.4-2.9 g cm~^). Although hollow, they will stand up to the high pressure of injection moulding with insignificant breakage of spheres. Dimensional stability, lower viscosity, and improved flow are the main advantages, but there are also improvements in mechanical properties. Loadings are generally from 5 to 15%, but some thermoplastics have been tested to 25% loading, with good results. Spherical particles can also be added to conventional glass-fibre reinforcement to compensate for directional orientation and improve the overall reinforcement effect. Tensile, flexural, and impact properties of compounds filled with hollow glass spheres are similar to those with solid spheres and research shows that there are significant benefits in properties when organosilane coupling agents are used. Lightweight, hollow, inert ceramic microspheres (Cenospheres), formed during the burning of pulverized fuel, have gained interest as a complement or alternative to hollow glass microspheres. They have a specific gravity in the range 0.55-0.75 g cm"^ (significantly lighter than conventional fillers and polymer matrices). Application depends essentially on reduction in volume cost of the compound. A plastics compound can be filled to a level of 40% by volume and still be a readily mouldable material, but without the additional weight of a solid filler such as talc. The microspheres can be direct-dosed into the moulding machine. Expanded perlite particles are friable and vulnerable in thermoplastic processing equipment, unless added at a late stage in plasticizing, where there is considerably lower shear. With a smaller size and tougher particles, ultrafine expanded perlite is claimed to offer advantages under such conditions. It is virtually impossible to avoid damaging these microspheres but, even when there is a substantial degree of breakage under processing conditions, a thin ceramic flake is produced with good potential for reinforcing and hardening the surface of a thermoplastics compound. 43.8 Expandable
microspheres
Another approach is to use thermoplastic microspheres encapsulating a gas, in unexpanded or pre-expanded form. When heated (usually at about 100°C), the
30
Additives for Plastics Handbook
thermoplastic shell softens and the vapour pressure of the encapsulated gas increases, expanding the sphere 34-50 times, creating an ultralight microsphere with resilient properties. The expansion also results in reduction of surface defects, voids, and hollow parts. Expanding polyacrylonitrile microspheres, filled with pressurized iso-pentane which expand when the shell softens at moulding temperatures, are offered by Akzo Nobel Casco Products Division, under the Expancel name. New applications include shoe soles and slush-moulded PVCs. Fly ash ^floaters' - tiny hollow spheres of ash from the scrubbers of power plants - are used by the US processor Power Composites for mechanical and acoustic properties in a polyurethane mix, for moulding automobile loudspeaker enclosures. They flow easily and uniformly in the mould as part of the polyurethane mixture, giving good additional strength to the enclosure. 43.9 Cellulose fillers
The growing interest in environmentally friendly materials has produced a reevaluation of cellulose materials as fillers in plastics and, with the advantages of modern technology, some progress has been made in producing materials that are technically consistent. A cellulose granule claimed to have wide applications as an extender in plastics is derived from the woody ring of the corn cob. Named Grit-0'Cobs (marketed by Andersons) it is very hard, dense, and absorbent. Environmentally inert and biodegradable, it is reported to be virtually non-dusting and capable of absorbing more than 95% water, while retaining free-flowing characteristics. It has a pH value of 4.9, making it compatible with a wide range of active agents. Particle sizes range from grade mesh 8 to 'flour'; bulk density and absorption characteristics can be modified to suit the application and colorants can easily be added.
4.4 Surface Modification
4.4.7 Particle
geometry
To offer better value, fillers are usually coated and surface modified, and special manufacturing processes are used to control the size and geometry of the particles. Researchers are now going down to the microscopic - and even to nanoscopic - scales to modify the surface of the material and improve the interface bond. The latest work on nano-sized particles show that these submicroscopic particles can give, at 5% addition, the sort of mechanical reinforcement that needs around 40% of a conventional filler such as talc. Small particle geometry generally does not improve mechanical characteristics, except for providing more rigidity. Lamina or fibre structures with larger particle geometry normally give stabilization with improved mechanical characteristics.
Modifying Specific Properties: Mechanical Properties - Fillers
31
But smaller particles may well also give increased stabilization by the increased cohesion between filler surface and polymer chain. Particle-type mineral additives are classified as two- and three-dimensional. The two-dimensional silicates in layers (such as talc and mica) essentially give rigidity and thermal stability but do not completely reach the stiff'ening effect of fibre-type reinforcements. They share high precision with three-dimensional fillers such as calcium carbonate, due to lower shrinkage anisotropy. The surface determines the number of potential polymer/filler adhesion points: a large surface gives many points, with better mechanical characteristics, but too large a surface can give dispersion problems or uncontrollable viscosity in processing. Fillers can be surface treated to improve adhesion and improve mechanical properties. The process can also improve moisture resistance, reduce surface energy and melt viscosity, improve dispersion and processing characteristics, reduce the need for stabilizers and lubricants, and improve the end-product surface. Special silane coupling agents that produce a chemical reaction with the polymer may improve stiffness and/or toughness considerably, but they tend to be expensive, and other routes are worth investigating. Thermo-oxidative stability is also important, and is influenced by trace amounts of heavy metals (iron, magnesium, copper) in most carbonates and silicates. These also influence UV stability for outdoor applications. 4.4.2 Coating Coating is increasingly used to enhance the properties of fillers. One of the most widely used materials is stearic acid. Metal stearates are particularly effective as coatings for reactive particulate fillers, such as magnesium hydroxide (MH), producing polypropylene compounds with better impact resistance than those containing uncoated, or stearic acid-coated fillers. Stearic acid will react to produce stearates, while stearates melt and form coatings. In some cases stearic acid or products of the intermediate melting temperature are produced later in the process, presumably by hydrolysis. Stearic acid produces the best coverage on calcium carbonate, but the poorest on MH. Of the metal stearates, the best filler coverage is produced when zinc stearate is used. An advantage is that hydrated inorganic fillers, in particular MH and aluminium hydroxide (ATH) and certain inorganic tin compounds such as zinc hydroxystannate (ZHS), are established fire-retardant additives for polymers. When specially coated with ZHS, MH and ATH confer significantly increased combustion resistance and lower levels of smoke evolution on plastizised PVC and polychloroprene. This permits large reductions to the additive loading without sacrificing flame-retardant or smoke-suppressant performance. Under certain conditions, ZHS and other tin compounds may also inhibit combustion in the vapour phase, functioning as non-toxic alternatives to antimony trioxide in halogen-containing formulations. Physical mixtures of ZHS and ATH also appear to give synergistic effects in PVC.
32
Additives for Plastics Handbook
4.5 Nano-technology
The intimacy of the filler/matrix bond is the main key to the performance of fillers and, with the latest technology, it is possible to achieve very good dispersion and an almost molecular bond. Tiny filler particles - sub-microscopic and also nanosized - have been shown to produce better mechanical properties at considerably lower loadings, and also give better flow, high barrier properties, inherent flame retardancy, and difl'erent surface textures in the same moulded part. Incorporated in a polymer matrix, typically to improve its barrier properties, they literally form a labyrinth' in the matrix, which considerably impedes the passage of substances like gases, oils, and greases. Alternatively, they can be incorporated in coatings to perform a UV screening function, with the significant advantage that, being smaller than the wavelength of visible light, the coating remains transparent. The unique properties arise mainly from the aspect ratio - a single gram has a surface area of more than 750 m^. Some automobile companies have been testing compounds: GM has been working with Montell on a thermoplastic olefin elastomer with 5% smectite clay from Southern Clay Products, giving stiffness equivalent to 2 5-35% talc and Dow Automotive Group has been working with Magna. Nano-particles may also play a significant role in development of 'hard' coatings on plastics glazing for automobiles. Incorporation of somewhat larger particles provides another interesting technology being developed by Bayer, in the field of polyurethanes. The company, with its machinery subsidiary Hennecke, has developed a new mixing head which enables expanded graphite in the form of millimetre-sized particles to be processed as a filler for rigid foams. The graphite particles must not be physically damaged during mixing, even under high pressure, and also have to be uniformly distributed in the foam, which is a real challenge to chemical engineering. A process has been developed and patented which could make it possible to produce flame-retardant polyurethane rigid foams without the use of halogenated additives. This new development could be especially important in the thermal insulation of buildings. Nano-scale hollow carbon tubes thousands of times smaller in diameter than carbon fibres are also of interest. Compounder RTP has commercialized a range of Nanotube Compounds (NTCs) that deliver uniform and precise surface resistivity throughout a spectrum from strong electrostatic discharge (ESD) to strong anti-static (typically ranging from 10^ to 10"^ ^/sq). To achieve similar levels of conductivity using conventional additives such as carbon fibre or carbon black would require higher loadings that may affect physical properties such as strength and toughness/impact, processing, and surface finish. 4.5.7 Processing
nano-composites
The key components of polymeric nano-composites are water-swellable synthetic and natural layered silicates such as montmorillonites (the main
Modifying Specific Properties: Mechanical Properties - Fillers
33
fraction of the clay mineral bentonite). These are commonly used for a number of other purposes and are commercially available in different types. The high aspect ratio of the layers strongly influences the properties of the host polymer and polypropylene provides one of the most interesting of these. To obtain the value of the properties, the layers have to be separated (called 'exfoliation'). For addition to a polymer melt the layered silicates are usually swollen, making exfoliation much easier than with dry silicates. The swelling agent has to have a boiling point higher than the melting temperature of the polymer but noticeably lower than the permissible melt processing temperature. In the case of polypropylene, swelling agents with boiling points between 180 and 200°C have been used. The consistency of the mixture of silicate and swelling agent depends on the silicate/swelling agent relationship, the 'swellability' of the silicate, the type of swelling agent, and the temperature, and can range from liquid through slurry to a crumbly paste. The are two basic ways of making polymer/clay hybrids. Direct polymerization in the presence of clay platelets has been used successfully for polyamides and for epoxy and other resins. But, at a less exotic and more flexible level, compounding offers an economic way of modifying polypropylene - in theory - and there has been some active development of processes to produce polypropylene/clay hybrids by melt mixing. To achieve the high level of dispersion required, slurry processes are being developed both as a means of opening up the fine clay particles and separating the plate-like layers, and also to incorporate sub-microscopic particles of calcium carbonate into polypropylene. The filler is introduced as a slurry in 2 5% water at the start of the process and with polypropylene in powder form. During plasticizing, the water content of the slurry vaporizes and is vented by the usual degassing aperture. Researchers at Dresden University and at Elf Atochem's research and development centre at Serquigny, France, have been working on modification of a standard Werner and Pfleiderer in which, rather than adding the filler to the melt, the filler is brought in at the beginning of the process, as a slurry in water, and mixed with a powdered form of polypropylene.
Table 4.4 Properties of a nano-composite PAG compound, compared with conventional reinforcement
Tensile strength (psi) Flexural modulus (1000 psi) Notched Izod impact strength Heat distortion temperature (°C) Specific gravity Source: RTP Co
Unfilled
3-5% organo-clay
30% mineral
30% glass fibre
7250 120 1.2 66 1.13
11 800 500 1.2 110 1.14
8000 650 1.6 120 1.36
23 000 1100 1.8 194 1.35
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Additives for Plastics Handbook
Table 4.5 Polypropylene nano-composite made by a slurry process compared with conventional compounds Unit
Reference (pure polypropylene)
Conventional compound
Slurry process
Chalk
wt%
().()
24.9
22.5
Flexural modulus
MPa
992
1428
1379
Elongation at break
%
639
125
594
Unnotched Charpy impact, 23°C Notched Charpy impact, 2 3°C
kjm-^
NB
140 1()0%B
kjm-^
13.7
10.3
160 40% B 60% NB 50.0
Multiaxial impact total energy, 3 mm. 4.3ms-^23°C
J
80 (ductile)
35 (semi-ductile)
74 (ductile)
Melt flow index, 23()°C, 5 kg
g(l()min)-i
10.5
4.0
4.5
Sourcc: Elf Atochcin
RTP has developed a technology for incorporating organo-clay hybrids into extruded nylon sheet or film via the compounding process. This form of lightweight composite requires only a loading of the order of 2-8% to exhibit properties equivalent to or better than typical mineral-filled compounds at 0 30% loadings. Much of the original w^ork on nano-composites came out of the Toyota Central Research Laboratories in the 198()s and the original licensee v^as Ube Industries, which has since been pursuing work on nylon 6 compounds. Other Japanese researchers have been concentrating their efforts on methods for the production of nano-sized carbon and fullerene tubes. These are tiny hollow fibres of carbon atoms arranged in rolled hexagonal lattices. Discovered by NEC's Sumio Ijima in 1991, they are creating interest in the plastics and automotive sector as conductive reinforcements for plastics, with possible large-scale use in automotive bodywork panels. Carbon nano-tubes are reported to be effective in assisting electrostatic painting at as low as 2% addition, and they also offer a better surface finish. But they are still expensive. Resin masterbatches containing 15-20% loadings are around US$44 kg~^ but producers expect these prices levels to fall with increasing use. GE Plastics reports that several automobile manufacturers in various parts of the world are running tests on filled mouldings for body panels, with the first commercial applications expected in 2 0 0 1 . Hyperion Catalysis International has introduced a range of graphite nano-tubes, under the trade name Fibril, for conductive applications in plastics.
Modifying Specific Properties: Mechanical Properties - Fillers
35
Table 4.6 Physical properties of nano-tubes in polycarbonate Property Tensile strength (kpsi) Tensile modulus (kpsi) Elongation (%) Flexural strength (kpsi) Flexural modulus (kpsi) Izod impact un-notched (ft lb in~^) Heat distortion temperature at 264 psi (°C) Shrinkage (%) Specific gravity
Base polymer
3.5% nano-tubes
5.0% nano-tubes
10.0
8.7 364 24 13.4 372 NB 129 0.5 1.21
8.9 399 30 14.5 401 26.5 124 0.5 1.25
-
125 14.0 340 NB 129 0.5 1.20
Source: Hyperion Catalysts
4.6 Commercial Trends
It is virtually impossible to place a value on the world fillers market, but specific sectors involving speciality types with higher economic potential have been surveyed. The best documentation comes from the US market, and it can be expected that the markets in Europe and Japan/Asia will be about the same size. US consumption of fine particle-sized calcium carbonates (which improve brightness and reduce absorption in a variety of polymer matrices) is expected to reach about 176 500 tonnes by 2003, valued at US$38.6 million. Use of fineparticle kaolin and other clay-based fillers in plastics will total 5 7 600 tonnes, valued at US$21.7 million, and compounders and resin producers are expected to increase use of fine-particle and surface-treated alumina trihydrate by 6.2% per year, from about 30 800 tonnes in 1998 to 41 700 tonnes by 2003. Antimony oxide fillers are now seen not only as useful flame retardants but also as providing valuable synergistic abilities (acting as potential replacements for titanium dioxide), while also controlling opacity, colour, and tone in various resin systems. MH fillers continue to gain market acceptance as alternatives to ATH and halogen-based flame-retardant systems. There is renewed interest in halogen-free formulations with smoke-suppressing properties and thermal stability, driving an annual growth rate of 6.1 % over the next five years. The global market for speciality silicas, including precipitated silica, silica gel, fumed silica, and colloidal silica, is estimated (by Kline, Belgium) at a value of US$1.7 billion. Demand is fairly evenly divided between Western Europe (34%), Asia/Pacific (32%), and North America (2 7%), with other regions accounting for approximately 7%. The market is expected to grow at a rate of about 4% a year in real terms, excluding significant inflation, to exceed US$2 billion by 2002. Precipitated silica is expected to grow at nearly 5% a year, because of expanding manufacture of rubber footwear in Asia, as well as emerging growth in 'green tyre' applications. Fumed silica, which is heavily dependent on silicone rubber, has an expected growth rate of more than 5% a year. The largest producers, Degussa, PPR, and Rhone-Poulenc, account for about two-thirds of global capacity for precipitated silica.
This Page Intentionally Left Blank
CHAPTER 5 Modifying Specific Properties: Mechanical Properties - Reinforcements The reinforcement used with plastics, both thermosetting resins and thermoplastics, is usually a fibre or filament, used either on its own, or in mixtures. Non-fibrous materials can also be used in some cases. Reinforcing fillers are also used, including glass flakes, mica platelets, fibrous and finely divided minerals, and hollow and solid glass microspheres. Table 5.1 At a glance: fibre reinforcements Function
Fibrous materials offer good reinforcement to plastics, depending on the strength and length of the fibre and the effectiveness of the fibre/matrix bond. Being fibrous, however, the main constraint is processability. For injection moulding and reaction injection moulding of polyurethanes, fibres must be very short, limiting the effectiveness of the reinforcement. Long and continuous fibres can be used in thermoset compression moulding, but these may require some form of preforming. Surface treatment of reinforcing fibre influences adhesion properties; coupling agents can improve properties with materials such as polypropylene.
Properties affected
Tensile strength, elasticity, dimensional stability under heat, wear properties; carbon and metal fibres/filaments/whiskers also give anti-static/electrically conductive properties.
Materials/characteristics
Glass fibre (overwhelmingly the most important). High-performance fibres (aramid, boron, carbon) are mainly of interest for thermosetting resin composites: growing use of high-performance thermoplastics will extend use of fibres.
Disadvantages
Adaptation of a two-dimensional fibrous reinforcement to a three-dimensional moulded component.
New developments
Long-fibre injection moulding compounds; improved surface treatment/coupling agents; use of high-performance fibres in forms more suitable for injection moulded thermoplastics.
The method by which the compound will be moulded or shaped naturally dictates the form of reinforcement. In thermoplastic compounds (which will be predominantly injection moulded), short-length fibre or particulate reinforcement is used, but there has been important development of so-called Tong'-fibre compounds, with a higher ratio of reinforcement to resin matrix and a longer
38
Additives for Plastics Handbook
length of fibre, delivering to the compound more of the basic strength of the reinforcement. In thermosetting compounds (which are in various forms for moulding by compression or by a modified form of injection), fibre lengths can be much higher. These are known as bulk moulding compounds (BMCs) or dough moulding compounds (DMCs). A third form of both thermoplastics and thermosetting compounds takes the form of a sheet material that is press-moulded or stamped. It comprises a mat of reinforcement (which can include non-woven or woven structures, with chopped or continuous filament reinforcement) impregnated with the thermoplastic or thermosetting resin. The mechanical properties of the compound are largely dictated by the reinforcement and its positioning (or orientation): a high reinforcement content
Figure 5.1. Polypropylene is reinforced with chemically coupled glass fibre for injection moulding this Whirlpool washing machine tub, giving high performance for low cost. (Photograph: Ticona)
39
Modifying Specific Properties: Mechanical Properties - Reinforcements
produces high tensile strength, but not necessarily high rigidity. As resin content increases, so does resistance of the moulding to chemical attack and weathering. The resin/reinforcement ratio is therefore one of the most important factors determining the properties of a reinforced plastics structure.
5.1 Fibres: The Basic Properties
Fibrous materials act to reinforce a matrix material by transferring the stress under an applied load from the weaker matrix to the much stronger fibre. Polymers provide valuable and versatile materials for use as matrices. For an efficient composite under stress, the elongation of the fibre must be less and its stiffness modulus higher than that of the matrix. Stress transfer along the all-important fibre/matrix interface can be improved by use of sizings, binders, or special coupling agents. The diameter of the fibre also plays an important part in maximizing stress transfer. Smaller diameters give a greater surface area of fibre per unit weight, to aid stress transfer in a given reinforcement context. Glass is predominantly the most important and widely used fibre in reinforced plastics. Other fibres are natural (cotton, sisal, jute), synthetic (nylon, polyester, acetate, rayon), or organic and inorganic high-performance fibres (aramid, boron, carbon/graphite). Fibres are used mainly in the form of short or long chopped filaments/strands, mats made of random chopped strands, or woven fabrics of varying density. Woven and non-woven fabrics can be used to improve surface qualities such as appearance, impact resistance, abrasion, and chemical resistance. To improve distribution and orientation of fibres in a three-dimensional moulding, there has been considerable development of preforming techniques, and machine-made three-dimensional arrangements of fibre, which offer better 'drape' in a mould. When more than one fibre is used, the composite is termed a hybrid. Table 5.2 A quick guide to the relative properties of fibres Property
Aramid
Carbon
Glass
Tensile strength Tensile modulus Compressive strength Compressive modulus Flexural strength Flexural modulus Impact strength Interlaminar shear strength In-plane shear strength Density Tension-tension fatigue
0 0
0
0 ++ 0
++ ++ ++ ++ ++ ++ 0 ++
0 ++ 0
++ 0 ++
Key: ++ = best,
0 = average,
-
0
-
- = poorest.
0 0 0 ++ ++
40
Additives for Plastics Handbook
Table S.3 Comparison of commonly used reinforcing fibres Fibre/grade
Density (gcm-^)
Tensile strength (MPa)
Flexural modulus (GPa)
Specific modulus (Mm)
Carbon HT Carbon IM Carbon HM Carbon UHM Aramid LM Aramid HM Aramid UHM E-glass R-glass Quartz glass Aluminium Titanium Steel (bulk) Steel (extruded) Steel(stainless)
1.8 1.8 1.8 2.0 1.45 1.45 1.47 2.5 2.5 2.2 2.8 4.5 7.8 7.8 7.9
3500 5300 3500 2000 3600 3100 3400 2400 3450 3700 400 930 620 2410 1450
160-2 70 270-325 325-440 440+ 60 120 180 69 86 69 72 110 207 207 197
90-150 150-180 180-240 200+ 40 80 120 27 34 31 26 24 26 26 25
5.2 Types of Reinforcing Fibre
5.2.7 Aramid fibres
These have a low density/high tensile strength ratio and are produced by spinning a liquid crystal polymer, usually as filament yarns, rovings, or chopped fibres. They are produced from an aromatic polyamide and have a characteristic bright golden yellow colour. The fibre has high strength and relatively low density, with very high specific tensile strength. All grades are particularly good in resistance to high impact; lower modulus grades are widely used in antiballistic applications. The compressive strength, however, is unexceptional and only equivalent to that of glass. Aramids represent a large part of the world market for high-performance fibres, which totalled some 40 000 tonnes in 1990, with a growth rate estimated at 10% annually. Applications are no longer limited to the very high-performance sector; in fact, a large part of the business of aramid fibres is in combinations with other reinforcements, giving precise properties precisely where they are required. To date, however, the majority of applications have been in fairly large structures with thermosetting resins (as in aerospace and transport). Outside the thermosetting resins, aramid fibre is also used in speciality tyres and, as commingled yarns, in production of thermoplastic composites, using a polymer melt, solution, or powder, or a hybrid yarn or fabric, suitable for high drapability and coping with very sharp fillet radii.
Modifying Specific Properties: Mechanical Properties - Reinforcements
41
An interesting development for thermoplastics is a technique for pulping or fibrillation that greatly increases the surface area of short-length fibres of paraaramid, and renders them suitable for reinforcement of plastics and elastomers. While a typical staple fibre will have a surface area of about 0.1 m^ g~^, the new compounding process increases this to 7-9 m^ g~^, so increasing the area available for adhesion to the matrix polymer. The bond achieved will improve properties of the compound, particularly abrasion resistance. High strength/low weight, mechanical stiffness, and resistance to thermal and chemical attack are other advantages. The development has been commercialized (by DuPont) as a masterbatch for elastomers (for power transmission belting, hose, tyre bead and tread areas, bearings, packings, and seals) and for thermoplastics (for a wide variety of applications). A similar development has been reported by Akzo. Techniques for production of three-dimensional structures of high-tenacity aramid fibre have also been developed, offering excellent fatigue resistance to abrasion, flexure, and stretching. One such system is on a wire frame basis, with mechanized frame building, and is proposed as a reinforcement for concrete pillars and other structures. As well as the strength of the fibre, this application exploits the high chemical resistance of aramid to acids, alkalis, and cement. 5.2.2 Carbon or graphite fibres
These are widely used in high-performance applications, well repaying their high cost. The fibre ranges from amorphous carbon to crystalline graphite, depending on manufacturing method. Stiffness or Young's modulus can range from less than glass to three times that of steel; the most widely used types have a modulus of 2 0 7 - 2 6 8 GPa. The fibre is available as short-length fibres, twisted and non-twisted yarns, continuous filament, and tows. Carbon/graphite fibre is produced by controlled oxidization and carbonization of precursors in fibre form. The usual precursors are cellulose, polyacrylonitrile (PAN), lignin, and pitch, of which PAN is most commonly used as it has a high carbon content. Treatment at temperatures up to 2 600°C produces a high-strength fibre and increasing the temperature to 3000°C produces a high-modulus graphite fibre. This chemically changes the fibre, yielding high strength/weight, high stiffness/ weight properties obtained through oxidation, carbonisation, and graphitization. Successive surface treatment and sizing improves bonding and ease of handling. The resulting fibre is stronger than steel, lighter than aluminium, and stiffer than titanium. Fibre can also be produced from a pitch precursor, but the elongation of these fibres tends to be low. The usual grades of carbon fibre (indicated by their initials) are high strain (HS), high strength (HT), and intermediate grades, such as intermediate modulus (IM). The most common form is a high-tensile-strength fibre, produced by most suppliers. Carbon fibres have the highest specific stiffness and very high strength in both tension and compression. Their impact strength is lower than that of glass or aramid fibres, and carbon is often combined with these to form hybrid materials.
42
Additives for Plastics Handbook
Table 5.4 Typical properties of continuous pitch-based carbon fibres (based on BP Amoco Thornel grades)
Tensile strength (GPa) Tensile modulus (GPa) Density (gem'^) Elongation at break (%) Filament diameter (|im) Carbon assay (%) Surface area (m- g~^) Electrical resistivity ()i ohm-m) Thermal conductivity (W m"^ K~^) CTEat2rC(ppm°C"M
Carbon
Graphite
Ultra-high conductivity graphite
1.38-2.07 159-3 70 1.90-2.0 0.9-0.5 11-10 97+-99+ 0.70-0.35 13-8.5 22-120 -().60to-1.3
2.10-2.41 517-82 7 2.00-2.17 0.4-0.3 10 99 + 0.3 5-0.40 7.0-2.2 18 5-640 -l.14to-l.45
2.34-3.10 896-965 2.17-2.20 0.3 10 99 + 0.40 1.2-1.3 800-1000 -1.45
Source: BPAmoco
Table 5.5 Typical properties of continuous PAN-based carbon fibres (based on BP Amoco Thornel grades)
Tensile strength (GPa) Tensile modulus (GPa) Density (gem ^) Elongation at break (%) Filament diameter ().im) Carbon assay (%) Surface area (m- g ') Electrical resistivity (|.i ohm-m) Thermal conductivity (Wm 'K ') C T E a t 2 r C ( p p m ° C ')
T-3()()^'
T-3()()C
T-65()/35''
T65()/35
3.75 231 1.76 1.4 7.0 92 0.45 18 8 -0.60
3.75 231 1.76 1.4 7.0 92 0.45 18 8 -0.60
4.28 255 1.77 1.7 6.8 94 0.50 15 14 -0.60
4.28 255 1.77 1.7 6.8 94 0.50 15 14 -0.60
'' Development grades. Source: BPAmoco
Carbon fibre can be supplied as continuous or cliopped fibre. Continuous fibre can be combined witli virtually all thermoset and thermoplastic resin systems and is used for weaving, braiding, pre-preg manufacture, and filament winding. Chopped fibres can be used in moulding compounds for compression and injection, giving parts with high resistance to corrosion, creep, and fatigue, with high strength and stiffness. In thermoplastics, carbon fibre is particularly used in reinforcement of nylon, where a 30% (by weight) fibre content will increase fiexural strength by about three times, and fiexural stiffness may be increased by a factor of seven. Electrical properties, friction behaviour, and wear resistance may also be improved. Electrical applications fall into two categories: to impart conductivity, to prevent build-up of electrostatic discharge (which may cause short circuits, or
Modifying Specific Properties: Mechanical Properties - Reinforcements
43
explosions when handling hazardous materials); and to screen components from electromagnetic interference. Frictional and wear properties are very good in comparison with nonreinforced or glass fibre-reinforced compounds. Non-reinforced PA 6 has static and dynamic friction coefficients about 2 5 and 40% higher than those of a carbon-reinforced PA 6, while the abrasion factor is 10 times higher. Combined with the higher thermal conductivity of carbon-reinforced compounds, this produces higher pv values (p = bearing pressure, v = sliding velocity), which are a measure of the heat generated by parts sliding in contact with each other. 5.23 Glass fibre
This is the most widely used reinforcing material, both for thermosetting and thermoplastic composites. It has high tensile strength combined with low extensibility (3.5%), giving exceptional tensile, compression, and impact properties, with a relatively high modulus of elasticity and good bend strength. It also has high-temperature resistance and low moisture pick-up, giving good dimensional stability and weather resistance. Finally, low moisture absorption makes it possible to produce mouldings with good electrical properties that do not deteriorate, even under adverse weather conditions. Glass fibre also exhibits virtually elastic behaviour. It will stretch uniformly under stress to its breaking point without yielding and, on removal of the tensile load short of breaking point, the fibre will return to its original length. This lack of hysteresis (which is not found in conventional metal and organic fibres), together with high mechanical strength, makes it possible for glass fibre to store and release large amounts of energy without loss. This capability, together with dynamic fatigue resistance, if protected from abrasion, has been put to effective use in springs for automobiles, trucks, trailers, and furniture. The fibre is produced by blending together the raw materials (sand, kaolin, limestone, and colemanite) and feeding the mix into a batch oven heated to about 16()()°C. The liquid glass fiows into channels and the fibres are drawn through electrically heated bushings, each of which can produce thousands of filaments of 10-24 |im in diameter. The filaments are coated with size to ensure cohesion and protect them from abrasion (also providing properties essential for subsequent processing operations). Finally, the wet fibre is dried and processed into its finished form. There are several types of glass: • •
A-glass (for 'alkali') is the original type of glass fibre. This is a high-alkalicontent material, with a chemical composition similar to that of window glass. It has been largely replaced now by other forms. E-glass (for 'electrical') is a calcium alumino-borosilicate composition, of low alkali content and stronger than A-glass. This is regarded as the pioneer type and is the type usually specified for reinforcement purposes, unless operating stresses are relatively low. It has good tensile and
44
Additives for Plastics Handbook
• • •
compressive strength and stiffness, good electrical properties, and relatively low cost, but impact resistance is relatively poor. C-glass (for 'chemical') is a grade with improved resistance to chemical attack, mainly used for surface tissue. D-glass has particularly good dielectric characteristics and is used mainly in the electronics industry. R- and S-glasses have a different chemical composition, giving a higher tensile strength and modulus, and better wet strength retention. They were developed to meet the demand for higher technical performance from the aerospace and defence industries. They have smaller filament diameters, which increase the surface area so improving interlaminar strength and wet-out properties. S-glass is produced in the USA and R-glass in Europe; the properties are broadly similar and the density is the same as that of E-glass.
Table ?.6 Main properties of glass fibre Unit
E-glass
R-glass
Mechanical properties (new, untreated filament) Ultimate tensile strength MPa lO^psi Flexural modulus GPa lO^psi Elongation at break % Poisson's ratio
493
638
10.5 4.4-4.5 0.22
12.7 5.2
General properties Specific gravity (in bulk) Specific gravity (in filaments) Mohs hardness
2.60-2.82 2.50-2.59 6.5
2.55 2.53
2.80
2.30
1.550-1.566 Opaque
1.541
Thermal properties (glass in bulk) Coefficient of thermal expansion
10-
Optical properties Refractive index (at 2 5°C) UV transmission (at 2 5°C) Electrical properties DC volume resistivity (logi Q 150-400°C) Dielectric constant at 10^ Hz (30 mm diameter disc 3 mm thick) Chemical properties Alkalinity (Na20 equivalent) Solvent resistance Alkali resistance Acid resistance
ohm.cm ohm.cm
17.7-10.4 6.5-7.0
6.0-8.1
% % % %
0.3 Good Good Except hydrofluoric
0.4 Good Good Except hydrofluoric
Modifying Specific Properties: Mechanical Properties - Reinforcements
45
5.2.3.1 E-CR glass The development of the different types of glass fibre has been in response to demand from specific markets, and the latest call is for improvement in long-term resistance to chemicals. The whole sector termed *anti-corrosion' is now one of the most important applications for glass fibre-reinforced materials, embracing the industries of marine products, chemicals, pulp and paper, and food manufacture as well as water treatment, anti-pollution, power plant desulphurisation, and many other important sectors dealing with environmental protection. E-glass fibre is widely used for its high strength/cost ratio, but glass generally is not totally inert in chemically corrosive environments and to meet many design codes requiring a corrosion barrier or liner to be incorporated in a laminate, to protect the structural integrity of the glass-reinforced substrate, a resin-rich layer supported by C-glass, or an organic fibre veil such as polyester or acryfic, has been used, to act as an impermeable protective layer. However,
Table 5.7 Glass fibre: comparison of E- and E-CR glass
Average glass composition (indicative only) (%) SiOi AI2O5 B2O3 CaO MgO Na20 + K20 Fe203 ZnO Ti02 Properties Tensile strength (MN m^) -virgin fibre 23°C -virgin fibre 100°C -virgin fibre 196°C E-modulus of elasticity (GN m^) Density (gem"^) Refractive index Coefficient of linear thermal expansion {°C~^) Dielectric constant, 23°C - 6 0 Hz - 1 0 ^ Hz Loss tangent, 23°C - 6 0 Hz - 1 0 ^ Hz Volume resistivity, 2 3°C and 500 V DC (^/cm) Dielectric strength (kV mm)
E-glass
E-CR glass
52-56 12-16 5-11 15-2 5 0-5 0.5-2.0 0.05-0.5
52-56 10-15
-
0-1.0
18-25 0-5 0.5-2.0 0.05-0.5 2-5 0-3.0
3331 3185 5320 72.5 2.52-2.62 1.556 5.0 10-^
3330 3240 5280 72.5 2.70-2.72 1.576 5.9 10-^
6.4 6.2
7.1 7.0
0.003 0.004 1014 9.80
0.004 0.003 1014 9.96
-
46
Additives for Plastics Handbook
sustained stresses and corrosive attack by strong acids or alkalis act synergistically, gradually deteriorating E-glass fibres. E-CR glass (for 'corrosion resistant') was developed to cater for this market. It has significantly better resistance to acid corrosion than E-glass, although its composition does not differ greatly, the main difference being that it does not contain boron oxide. It is listed for improved resistance to acidic corrosion in ASTM D5 78 and ISO 2078, and under DIN 12 59 is classified as aluminium limesilicate glass that is particularly designed for reinforcement of plastics submitted to acidic environments. Grades of this glass have Lloyds approval and are certified to meet the Boeing BMS-8-79 specification. The sUghtly higher density of E-CR glass is not a serious factor, as the diameter ranges are within the tolerances of traditional E-glasses. A slightly higher refractive index may give E-CR glass laminates a slightly more yellowish tint, which is barely distinguishable. Tests for laminate properties indicate that the moduli and stiffness of laminates made with each type of glass are identical. Tensile, flexural, and shear strengths are generally equal or slightly higher with E-CR. Long-term behaviour (tension creep in air) is identical. 5.2.3.2 Other developments Among other recent developments are new types of glass fibre roving designed for use in sheet moulding compound (SMC) and giving both good processing characteristics and mechanical strength. These are a medium-hard/mediumsoluble reinforcement with high integrity for SMC automotive and industrial applications where the mouldings are either pigmented or painted. They wet-out quickly and thoroughly, and offer good composite mechanical properties, especially tensile and flexural strength. New glass fibre-reinforcement products for use in fibre-directed preform processes are another focus of development, designed specifically for liquid composite moulding applications such as resin transfer moulding with thermoset polyesters. A new E-glass roving gives fast wet-out with polyester, vinyl ester, epoxy, phenoUc, urethane, and furan resin systems, due to low sizing content. Low loss on ignition means that there is not an excessive amount of sizing to be broken down by the styrene in the resin. Owens Coming's Miraflex fibre is two different forms of glass fibre fused together in a single filament, resisting typical textile processes such as carding and needling: the fibres are random twisted, flexible, soft-touch, and virtually itch free. Also working on mixtures, Vetrotex CertainTeed has developed Twintex - a commingled reinforcement of unidirectional glass fibre rovings and polypropylene filaments. PPG Industries has introduced MatVantage - a continuous strand mat for pultrusion, offering unique laminate characteristics - and new low-catenary conventional rovings plus three new chopped strands for thermoplastics. Type 2016 roving is for direct-draw filament winding for oilfield composite pipe and
Modifying Specific Properties: Mechanical Properties - Reinforcements 4^7
other corrosion applications, Type 5530 roving is for Class A automotive painted parts, pigmented applications, and others, and GPN chopped strand mat is for composites with general-purpose polyesters. A glass reinforcement said to offer superior mechanical properties in compounding polypropylene, enhancing the performance of both coupled and uncoupled formulations, is Star Stran from SchuUer Mats and Reinforcements. It is a high-strand integrity product with good fibre feed and handling characteristics, in 3.175 and 4.76 mm chopped lengths. 5.2.3.3 Forms of glass fibre The form in which glass fibre can be used for reinforcement is of course largely dictated by the moulding process. For thermoplastics, where the main process is injection moulding, the glass is used in short (about 0.3 mm) fibre lengths, which will pass through the nozzle of the machine without being too severely damaged in the process. There has been much development, therefore, of treatments to the surface of the glass fibre and improvement of the fibre/polymer interface, to provide a degree of lubrication and prevent damage to the fibre. The process of injection into a closed mould also means that the orientation of the fibre (which essentially provides the strength) is difficult to control, and there has also been much work on mould design to encourage flow and orientation in desirable directions. An important development in recent years has been the introduction of thermoplastics compounds with longer fibre lengths (called 'long-fibre' compounds), in which the fibre and resin are combined in a different manner, giving higher lubrication and allowing higher fibre/resin ratios to be employed. These compounds are described in more detail below. For reinforcement of thermosetting plastics (where the moulding processes are manual with an open mould, various forms of compression/contact moulding, or actual winding of reinforcement onto a former), glass fibre is used in continuous and discontinuous forms, as roving, bonded mats, or a wide variety of woven or knitted textile forms. An increasing amount of glass fibre is suppUed as continuous roving that is chopped into small lengths in resin mixing and spraying units. Using roving rather than continuous strand mat has an important economic benefit because the glass costs less, and there is less waste. An important area of development is how best to preform the fibre reinforcement, and a key advantage of the fibre-directed preform process is the ability to change reinforcement strand geometry simply by changing the input: impact strength increases as the roving strand geometry becomes more coarse, while tensile and fiexural strengths are only minimally affected. Another area of current development is design of 'three-dimensionaF fabrics, which will provide bulk and/or lend themselves easily to the shape of a required moulding without the need for expensive preparation stages. 5.2.3.4 Chopped!milled products Continuous-strand/high-modulus fibre is chopped to 3.2-50 mm (|of an inch to 2 inches) or milled/ground into shorter lengths for use in moulded composite
48
Additives for Plastics Handbook
parts; pre-preg products are a standard grade modified with (typically) an epoxy resin curing at 120°C, as unidirectional pre-preg rolls. Milled fibres are produced by hammer milling, giving lower stiff'ness and strength than chopped fibre, but controUing heat distortion and improving surface finish. They are normally used in liquid component mixing/ injection processes such as reinforced reaction injection moulding (RRIM) of polyurethanes. Because of fibre length and Ughtness, they can cause dust and irritation in the production shop and should only be handled in closed systems. Glass flakes are used in resin-based coatings, to reduce permeability to moisture, vapours, and solvents; they have also been used in reaction moulded polyurethanes to improve surface finish. 5.2.4 Polyester fibre
This offers a low-density, high-tenacity fibre with good impact resistance but low modulus. It is used in areas where high stiffness is not required, but where low cost, low weight, and high impact or abrasion resistance are important. Polyester is used mainly in surface tissue for laminates, but also offers high impact resistance, good chemical resistance, and good abrasion resistance. The advantages of polyester are that it does not need binders that have to be dissolved in the resin matrix, it has high conformability, and excellent strength/ weight ratio. As a surfacing material, the fibre is easy to sand. Fabrics are half the weight of equivalent glass material, with excellent energy absorption, chemical resistance, and dielectric/electrical insulating properties. They are internationally certified by Lloyd's Register of Shipping and the American Bureau ofShipping. Polyester fibre does not specifically feature in thermoplastics compounds at present, but there has been some interesting work reported (by DSM), compatibilizing thermoplastic polyesters to accept polyester fibre as a reinforcement, which might greatly simplify the recycUng of fabric-covered automobile interior panels (if they were moulded in polyester in the first place). 5.2.5 Polyethylene
fibre
Recent work has produced a very low-density fibre from ultrahigh-molecularweight polyethylene (UHMW PE), which offers strengths that (for the density of the fibre) are among the highest to be found anywhere. It is made up of aligned polymer chains with high elongation and good impact resistance. But, although the fibre has remarkable properties, its low modulus and ultimate tensile strength and the relatively high cost of treating the fibre surface to improve the fibre/matrix bond mean that PE fibre is not often used in reinforced plastics structures. Performance figures show that specific gravity is low, at 0.97 (aramid is 1.44, polyester 1.38). The fibre is 35% stronger than aramid and has a high energy/ break ratio, giving remarkable ballistic properties. It exhibits impact energy
Modifying Specific Properties: Mechanical Properties - Reinforcements
49
absorption in composites 20 times that of glass, aramid, and graphite and also has excellent vibration damping properties. The melting point is 147°C. Possible applications for composites include boat hulls, sports equipment, radomes, structural components, pressure vessels, and in aerospace and industrial applications. 5.2.6 Hybrid fibres
An almost unlimited field of possibilities opens up with the combination of different fibres as 'hybrids', which with an appropriate resin matrix can most closely fill a specific closely identified application. In most cases, however, this is a matter for specialists, backed by an exhaustive database of fibre forms and properties. A typical off-the-shelf hybrid might be a boron/graphite pre-preg, composed of small-diameter graphite fibres dispersed between 76 and 100 [iui diameter boron fibres, in an epoxy matrix, to 70-80% total fibre content. This is claimed to achieve a hybrid effect with properties superior to composites based on either fibre. The flexural stiffness and strength is twice that of carbon and 40% higher than that of boron. Interlaminar shear strength also exceeds that of carbon and boron. The resin matrix can be a toughened epoxy or a polyimide.
5.3 Other Fibres
Other reinforcing fibres, of less commercial importance, include: asbestos, boron, and nylon fibres. 5.3.7 Asbestos fibre
This has been used in the past with both reinforced thermosets and thermoplastics, offering good rigidity, chemical resistance, and particularly fire resistance. Its use has, of course, ceased following discoveries of the health hazards associated with asbestos fibre. It may, however, be encountered in recovery of old mouldings, and advice should be sought immediately on the precautions necessary in handling it. 53.2 Boron fibre
This is of very high cost and is used with epoxy resins in specialized aerospace applications. 533
Nylon fibre
This may be used with epoxy resins, for high impact, abrasion resistance, and chemical resistance. In moulding compounds with thermoplastics matrices it has very widespread use.
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5.4 Natural Fibres
Natural fibres such as jute and sisal are inexpensive and readily available. Jute is used particularly in developing countries in cloth and yarn. Sisal fibre may be used in some DMCs, although more with phenolic matrices than with polyesters orepoxies. Good fibre strength and rigidity, plus low cost and environmental advantages encourage the use of vegetable bast and hard fibres such as flax, hemp, jute, ramie, or sisal for reinforcement of thermoplastics. Production of large and low/ medium stressed components in polypropylene reinforced with flax mat is gaining in popularity. With fight but extremely rigid parts, flax fibre-reinforced plastics could compete with glass-reinforced materials for applications such as automobile interiors, but the possibilities of this material in highly stressed structural components depend of the properties of the composite under dynamic stress. However, there is virtually no information yet available on this. The normal test for dynamic evaluation of materials or components is the Wohler fatigue test, to characterize fatigue behaviour. Hysteresis measurements are carried out on flax and glass mat-reinforced polypropylene, with a needlepunched flax mat using green and retted fibres to make plates with a quasiisotropic composite structure, and with treatment by a coupling agent. Green and retted fibres differ in the degree of fibre digestion and physical data. Green flax fibres are stronger and much coarser (fineness > 4 tex), but their modulus of elasticity is lower than that of retted fibres. Retted fibre has intensive fibre digestion, due to the action of moisture during retting, producing fine fibres with a high modulus and low strength as a result of decomposition during retting. Green flax has less intensive fibre degradation due to only brief exposure to moisture, producing a coarser fibre bundle with high strength and low modulus due to good elongation at break. Unlike glass fibres, which have a round section, industrial flax fibres are made up of numerous individual fibres or fibrils bonded together by vegetable substances and have a rough surface, meaning that they can already be regarded as composite materials. Flax fibres have a lower strength and composites did not achieve the tensile strength values of glass mat-reinforced polypropylene with the same fibre content. But high values are determined for modulus of elasticity. High-quality green flax has a better reinforcing effect than retted flax: a content of some 40% by weight produces tensile stress values in the range of those for glass matreinforced polypropylene at a content of 30%. Silane-treated fibres at 30% fibre content nearly reach the strengths and stiffnesses of 40% flax/polypropylene composites. The improvement in fibre matrix adhesion is found in both green flax and retted flax-reinforced compounds. Polypropylene compounds reinforced with flax and glass mat, at comparable fibre contents, have similar fatigue strengths when exposed to dynamic repeated tensile stresses. The flax fibre composites are characterized by their high material damping, which is attributable to the specific properties of flax fibres. Tests at
Modifying Specific Properties: Mechanical Properties - Reinforcements
51
microscopic level show that it is usually microcracks, tending to run transverse to the stress direction, which are responsible for the failure of fibre composites. Increasing the fibre content and improving the fibre/matrix adhesion improves fatigue strength.
5.5 Forms of Reinforcement
The available forms of reinforcement broadly follow terminology and technology 'borrowed' from the textile industry. The basic forms described above for glass are used, as appropriate, with all types of fibre, including hybrid mixtures. There are also thermoplastic equivalents, such as high-performance carbon/ PEEK tapes, which are 'pre-pregs' in which continuous filament and matrix have been closely combined by a form of pultrusion process and require only placing in position (often by winding or layering) and heating, to fuse the thermoplastic matrix. Technology extending the principle to continuous filament and polypropylene matrices has been developed more recently. A further variation is to bring both the reinforcement and thermoplastic matrix together in the form of fibres, which are then readily combined (described as commingled), giving an improved interfacial bond. An advanced form of this is based on biaxial thermoplastics in the form of fibres (PA, PBT, PET, PP/PPS, PEI, APC-2, or PSUl), with carbon, aramid, and glass pre-impregnated tape. The pre-preg is unidirectional and interlaced in a biaxial form in continuous lengths. The manufacturers claim that an unprecedented width (up to 3.04 m) is possible. Overall, the material maintains and improves the properties of unidirectional cross-ply laminates, giving the benefit of unidirectional tape in larger and more easily processed formats. With very good drape characteristics, it is claimed to be the first real alternative to the compromise often necessary with woven composites. Parallel to thermosetting SMCs and BMCs are thermoplastic moulding compounds in sheet form, known as glass mat thermoplastics (GMTs), and compounded into standard granules for injection moulding and extrusion. Most thermoplastics are theoretically capable of such combination with reinforcement, but the main types used commercially at present are polyamide (PA) and polypropylene (PP).
5.6 Long-fibre Reinforcement
In the production of a moulding compound (especially on a thermoplastic matrix), some amount of mechanical working is indispensable, with the result that any fibrous reinforcement is inevitably broken up into very short lengths. Anticipating this, very short lengths of fibre (typically 0.3 mm) have been used in thermoplastic moulding compounds. The mechanical properties of the compounds, however, are closely related to the length of the reinforcing fibre.
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For example, in an ideal PA 66 compound, reinforced with 50% glass fibre and with all fibres aligned along the length of the moulding, the flexural and tensile moduli increase rapidly as the fibre length is increased from 0.1 to 1.0 mm. As a result, technology has been developed to enable the use of long fibres (around 2 mm) in a thermoplastic resin matrix. These are produced, not by classical physical mixing, but by a process analogous to the 'pultrusion' process with thermosetting resin matrices, with internal lubrication additives to counteract the chopping effect of injection moulding. Similar effects have been measured with other fibres, such as aramid and carbon, and with other matrices, such as polypropylene and poly(phenylene sulphide). Long-fibre technology was pioneered by LNP Plastics when it was a subsidiary of ICI (and has since developed as a major independent compounder). Another compounder active in the field is the US group RTP. Ticona is another producer and a recent entry has been the French group Atochem (now AtoFina), which has developed a polypropylene material under the name Pryltex, in a joint venture between Appryl Composites and Multibase. Appryl's Pryltex range offers fibre lengths of 12, 18 and 25 mm and can accommodate glass contents of 10-50% by weight. The process is patented and involves coating the glass fibre roving with polypropylene and combining and cutting to the specified lengths after cooling. Compared with 20 and 30% glass-reinforced nylon, PP with 30% long glass fibre is claimed to be 10% fighter and faster and easier to mould. A long fibre-reinforced polypropylene material system, designed for automotive applications, is under development by the resin manufacturer DSM and the glass manufacturer Owens Corning, in a joint venture. Described as bridging the gap between injection moulded short fibre-reinforced plastics and press-moulded glass mat thermoplastics, the technology uses modified polymers and special mould design to allow longer lengths of glass fibre to be injection moulded, obtaining better mechanical performance. LNP Engineering Plastics published results of tests on a selection of die-cast metals compared with a 60% long glass fibre-reinforced polyamide 66 compound (Verton RF700-12EM). The conclusion was that (for moisture-conditioned samples) with a density lower than metals with the exception of certain magnesium alloys, a long fibre-reinforced PA 66 compound shows reasonable tensile strength, high impact, and good elongation. Flexural modulus, however, remains low. Table 5.8 Long fibre-reinforced tiiermoplastics: effect of fibre lengtfi Fibre length number average (mm)
Fibres longer than 0.2 mm (%)
Notched Izod impact strength (kjm-^)
0.2 7 0.32 1.38 3.54
35 57 89 99
17.0 29.5 32.5 39.0
Modifying Specific Properties: Mechanical Properties - Reinforcements
53
Table 5.9 Properties of typical long-fibre thermoplastic compounds^
Fibre content Density Notched Izod impact Flexural modulus Tensile strength Heat distortion temperature
Unit
PA66/ glass
PA66/ glass
PA66/ glass
PA66/6 glass^
PA6/ glass
PA/ aramid
PP/ glass
% gm"^ kj m-^
35 1390 20.0
50 1570 27.0
60 1700 32.0
40 1420 22.0
50 1570 30.0
40 1240 8.3
40 1220 20.0
GPa
11.0
15.8
19.0
12.0
15.0
7.1
7.5
MPa
210
230
250
200
200
117
110
°C
256
261
261
218
218
246
156
^ Blends of PA 66 and 6 have similar properties, with a heat distortion temperature about 16-18°C lower. ^ Hot oil/grease grade.
Table 5.10 Long-fibre plastics compared with die-cast metals (23°C)
Ultimate tensile strength Yield strength. 0.2% offset (MPa) Elongation (%) Young's modulus (GPa) Charpy impact (un-notched) (J) Shear strength (MPa) Density (kg m-^)
Zamak 3
Zamak 5
Mg AZ91D
Mg AS41A
Mg AM60
Al A380
Verton RF70012EM
283 221 10 8 5.5 57 214 6600
331 228 7 8 5.5 65 262 6700
234 159 3 44.8 3 138 1827
210 140 4 45 4.1 n.d. 1770
220 130 6-8 45 6.1 n.d. 1800
324 165 3 71 4 186 2713
230 4 16 10 115 1700
Source: LNP Engineering Plastics
5.7 New Developments
The technology for compounding long-fibre materials is sophisticated, but a costefficient system (which might open the way for smaller companies to become involved) has been demonstrated by Krupp Werner and Pfleiderer, Germany. The process is claimed to offer pellets at a cost lower than pultruded forms and only slightly more expensive than conventional short glass-fibre reinforced pellets. It is more flexible than pultrusion and permits the combination of various matrix materials, and degassing of the compound. The key component in the equipment is a patented impregnating head, in which the glass rovings are wetted with polymer melt before they are fed into the compounding extruder, rather than being wetted inside the machine, as is normal. The fibres are then mixed, the melt is degassed, and the product is discharged. The key point is that, as the filaments are already wet when they
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enter the machine, it has been possible to develop a screw configuration that gives gentle action and so causes little damage to the fibres. 5.7.7 Polyurethane/long
fibres
Long-fibre technology has also been extended to polyurethane reaction injection moulding (LFI-PUR) and has been used by Elastogran for mass production of large 1.3-7 kg mouldings for a heavy trucks, in LFI-PUR at the rate of 25 000 a year by KVG Kunststoff-Verarbeitungs, Geilenkirchen, Germany. Instead of using glass fibre in the form of a mat to reinforce the moulding, the LFI process uses glass-fibre rope, dispensed from a robot-controlled mixer casing, cut to length, and introduced into the open mould together with the liquid polyurethane. The technology is more flexible than using glass mat, particularly for threedimensional components, and allows the reinforcement density to be adjusted and apertures to be accommodated, in realistic series production. Waste is minimized and costs considerably reduced. Within a couple of months of startup, KVG was moulding 200 parts per shift and the target for full-scale throughput was reached in six months. Novel technology involving reinforcement of PVC with long glass fibre has been developed in the USA and will be commercialized by Decillion LLC, a 60:40 joint venture between glass fibre manufacturer Owens Corning and PVC manufacturer Geon. Technically, any combination of glass fibre and PVC is usually regarded as very difficult because of the high viscosity of the matrix polymer, but the new material, with up to 40% glass, is three times as stiff as unreinforced PVC, with a heat distortion point higher than 9 3°C. 5.7.2 ABS/long fibres
New technology for reinforcing ABS with long fibres has been developed by Dow Plastics. It is described as 'Vitamins' (because it can be introduced in the feed hopper of a plastics processing machine) and involves the use of a thermoplastic polyurethane as a compatibilizer between the glass and the ABS matrix (for it has good compatibility with both). The polyurethane/glass fibre can be added to the ABS matrix at loadings of from 20 up to 60%, producing a reinforced thermoplastic compound with physical and chemical properties similar to those of semi-crystalline engineering thermoplastics such as nylon, but at a more attractive price. The limitation, at present, is on the operating temperature, which is given as 98.8°C. Dow claims it has some commercial applications, citing office furniture, sports equipment, and luggage, but the technology could be particularly interesting in production of sheet (included co-extruded types) for thermoforming. 5.7.3 Shaped fibres
Short fibres with lumps at each end could prove a useful and practicable way of improving the strength of composites - simply by providing a mechanical key in
Modifying Specific Properties: Mechanical Properties - Reinforcements
55
the matrix to prevent pull-out of the reinforcement, according to researchers at the Los Alamos National Laboratory (LANL). Working with shaped fibres made from commercially available polyethylene grades in a polyester matrix, they have found that the fibres are firmly anchored into the matrix at each end by virtue of the wedge shape, but are only weakly bonded along their length. This allows the fibre to help carry the loading, and it has proved possible to configure the shape and size of the bone-shaped ends so that they do not undergo the stresses that often snap fibres and so limit the performance of a short-fibre composite. Compared with composites made of the identical materials but with straightended fibres, the bone-shaped fibre composites shows higher toughness and strength. Significantly, they are also much more resistant to crack-propagation, as the mechanically anchored fibres actually bridge the crack and hold firm. Computer modelling is now being introduced to help better understand the experimental results and aid in predicting the results of using other materials or different designs of fibre.
5.8 Commercial Trends
Sales of advanced and inorganic fibres are expected to increase globally at 9.3% a year up to the year 2002, according to Business Communications Co. Inc. (BCC). In the USA, the growth rate will be 10.8% a year, to reach a total market value of over US$1 billion. Development of high-performance fibres and the markets for them have been strongly infiuenced by the demand from military applications (which promoted the development of both carbon fibre and S-glass fibre). But, as the 'Cold War' ended, much of the military budget for new weapons also faded away, while the ever-increasing spiral of costs has also forced the military to examine more cost-effective solutions. As a result, manufacturers of fibres are now trying to maximize the commercial potential of advanced organic and inorganic fibres. The world market was over US$1 billion in 1997, with the US market by far the largest segment, representing over 60%. This situation will continue for the next five years forecasts BCC. The use of high-performance carbon fibre is expected to grow as prices are reduced. As a result of improved production technology and increased capacity, prices of carbon fibre, which were in the region US$26.5-33 kg~\ have come down to the lower level, but are still prohibitive for applications in automobiles and railways. However, a level of US$11 kg~^ (representing a 50% reduction) has been put forward as a guideline for large users. Compared with glass fibre, carbon delivers comparable physical properties at around 2 5% the weight, but this is not enough to offset a cost increase of some 4.4 times. But, at a price of US$ 11 kg~^ (as projected by Zoltec) the cost penalty is only 1.8 times where the user is looking only for tensile strength and comes down to 1.3 times where the key property is tensile modulus.
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As the cost of the precursor can account for as much as 70% of the total production cost of carbon fibre, an important contribution to cost reduction has been the development of other precursors. Table 5.11 Cost comparison between glass fibre and carbon fibre, specific mechanical properties (glass cost = 1.00) E-glass
Structural requirement
Compressive strength Tensile strength Tensile modulus
Carbon (2000)
Carbon (1997)
Weight
Cost
Weight
Cost
Weight
Cost
1000 1000 1000
1.00 1.00 1.00
419 267 147
6.91 4.40 3.14
419 267 147
2.88 1.84 1.30
Source: Reinforced Plastics
Table 5.12 Capacities for carbon fibre, worldwide, 1 9 9 6 - 2 0 0 0 (tonnes) Company
Location
Precursor
Capacity (1996)
Capacity (2000)
Toray Toho Rayon Amoco Hexcel Mitsubishi Zoltek Akzo Nobel SGL Totals
Japan Japan USA USA Japan USA/Hun gary USA/Holl;and UK/Germany
Special Special Special Special Special Textile Textile Textile
3700 2900 1900 1800 1800 1600 1 ()()() 900 1 5 700
7700 5100 1900 2100 3400 18 100 4800 2 700 45 900
Source: Reinforct.'d Plastics
CHAPTER 6 Modifying Specific Properties: Appearance - Colorants, Pigments, Dyes, Special Effects The use of pigments by people goes back to cave-dwelling times, but it is only in the last century or so that colour has become one of the foundation stones of the modern chemicals industry. The development of the plastics industry, however, brought colour to levels that could never have been attempted before. It has also raised fundamental questions about colour and how it is produced that have led to an explosion in development. The almost limitless possibilities of colour in plastics - particularly in transparent matrices like polystyrene - in turn gave birth to the compounding industry, as polymer manufacturers became unable to deliver the wide choice of colours demanded by markets such as cosmetics and packaging, and promoted a new industry of companies specializing in matching colours and compounding small batches, with great flexibility and rapid response. Most of those pioneers are still in existence (in some form), supplying formulations worldwide, with consistent batch-to-batch quality, saving processors time and inventory costs. As compounding developed, other additives were included in compounds, and colours themselves were developed offering other technical properties. Apart from soluble dyestuffs (which are used to a small extent in transparent and fluorescent products, for internal reflection and absorption) the colorants used in plastics are basically insoluble organic and inorganic pigments. From the beginning they have been mixed into plastics by the processors (often using the most basic equipment) but it is vital that they are properly dispersed in the matrix - and this is probably the most powerful argument in favour of separate compounding. Generally, inorganic pigments have good temperature and light stability, while organics meet the most demanding colour requirements. Toxicity and environmental considerations. Governing the use of pigments in plastics in contact with foodstuffs (such as packaging, food handling and processing equipment, kitchen appliances, working surfaces), most countries have their own legislation based either on actual permitted content of a specific ingredient, or maximum permitted extraction. There is concern in some countries about the effects of heavy metals entering the environment (as via dumped plastics waste). This has produced a trend away
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from pigments based, notably, on cadmium and the search is on to replace these with others of equal effectiveness. Table 6.1 At a glance: pigments, dyes, special effects Function
Colorants act either by absorbing parts of the spectrum and reflecting other parts (solid pigments, dyes), or by transmitting only certain wavelengths (transparent colours); these effects can be combined with multi-layer structures, also using interference patterns to achieve an effect
Properties affected
Colour, appearance: some pigments can also give shielding against UV light
Materials/characteristics
Organic; inorganic; pearlescent; metallic; special effects
Disadvantages
Can contaminate other materials/equipment unless kept separate or used in dust-free/non-polluting form; migration if not correctly compounded; thermal stability in processing at high temperatures: replacement of heavy metals with pigments of comparable performance
New developments
Easier forms for use/incorporation in compounds; colour concentrates, liquid colours; improved dispersibilty, better thermal stability; replacement of heavy metals; introduction of new chemistry
6.1 Main Types of Pigment and Colorant
Pigments are usually supplied as dry powders of various specific gravity and bulking value. Care is needed in handling, not simply because of the cost of the pigment, but also because it may present a dust hazard. Safe, dust-free formulations are now the general rule, but with so many other priorities many processors have clearly decided that colour is not their problem, and prefer to buy material ready-coloured. 6.7.7 Mixed metal oxides
These pigments are synthetic minerals. The desired colour is achieved by selecting specific metal oxides, based on metals such as chromium, nickel, antimony, titanium, manganese, cobalt, aluminium, zinc, iron, and copper. They are characterized by good heat stability, insolubility, excellent chemical resistance, non-bleeding/non-migrating, excellent weathering and lightfastness, good dispersability, good hiding power, strong, bright colours, and nonwarping. 6.7.2 Dyes
These are transparent and give bright colours in light. Most have relatively poor light fastness and limited heat stability, but will tend to retain their colour better
Modifying Specific Properties: Appearance - Colorants, Pigments, Dyes, Special Ejfects
59
than pigment systems because, as with all colorants, it is the surface layer that is affected by exterior conditions such as light and, while dyes will similarly suffer fading on the surface, their transparency gives a real depth of colour unaffected by surface influences. Dyes can also be subject to migration of colour, which is the subject of legislation for critical products, such as food-contact applications and toys. The choice between pigment or dyestuff depends on the compatibility of the resin matrix and the need for solubility. Other factors influencing selection include stability of colour during use, especially on exposure to light, air, and moisture, but also during processing. Some thermoplastics, such as the engineering types, require higher temperatures for moulding or extrusion, which may discolour a pigment system that is perfectly satisfactory with other materials at lower processing temperatures. Other important factors are strength/depth of colour, electrical properties, and resistance to migration. 6.7.3 Liquid
colours
A third form in which colorants are supplied is in liquid form, using a very precise metering unit mounted on the processing machine. As a direct method of colouring on the machine, this technology has been held back by technical
Figure 6.1. Structures of inorganic pigments: (top) rutile-cassiterite structure of inorganic colour pigments and (bottom) the spinel structure. (Illustration: Ferro Corporation)
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difficulties, particularly at the dosing stage, but its popularity is growing and it is becoming clear that it is complementary to masterbatch, rather than in competition with it. It is widely considered best suited to long runs, where dosing can be more controlled, but the latest equipment (such as Colortronic's new lowrate gravimetric additive feeder, Graviblend S) is claimed to bring colour changes down to seconds. Recent development has concentrated on liquid colours for PET, to meet the huge demand from the packaging sector. Ferro's SpectraFlo Type 99 is opaque, complementing its range of transparent colours, meeting FDA rules and offering a rapid colour change at a let-down ratio of 1000:1. A clear-tint PET green from Milliken is said to have advantages over other liquid pigment dispersions for PET, with cost savings over pre-coloured PET.
6.2 Addition of Colorants
Originally, pigments were dispersed in plastics simply by dry blending in a tumble-mixer - or in an oil drum. The plasticizing function of an extruder or injection moulding machine also offered a reasonably good method of dispersing a pigment but the penetration of plastics into more critical markets brought demands for greater homogeneity and consistency. To achieve best results, however, pigmented compounds need to be prepared before moulding, using dedicated equipment such as a compounding extruder, or pigments must be formulated as concentrates, in a form giving trouble-free mixing with virgin material alongside the moulding machine. Concentrates or masterbatches are consistent, simple, and safe. They usually come in a granular form, in which the concentrated pigment is dispersed in a polymer carrier (such as polyethylene) that is compatible with the matrix resin. The let-down ratio is usually 0.5-2%, depending on colour, host material, and part thickness. The advantages claimed include cost savings due to less handling, quick colour changes, savings with lower inventory and reduced storage requirements, no pollution from colour particles in the air, and easy and clean to use. Colour dispersion is so good that precise measuring and mixing are not essential (but good screw back-pressure is recommended), while there is no adverse effect on the physical properties of the host material. A typical range will cover around 400 colours, with a minimum order quantity of 25 kg, but some suppliers can supply down to 1 kg at a surcharge. Colour matching can also be done, usually on a minimum quantity of 50 kg. There are around 200 producers of colour masterbatch, the leaders being Cabot, Schulmann, Ampacet, andFerro. Whether the colour is added by a specialist compounder or by a good technical processor, the quality depends on dispersion and match. The pigment is dispersed by 'wetting' the particles with the resin, and the size and shape of the particles are therefore of great importance, as also are the rheological properties of the resin matrix. Apart from colour fidelity, good dispersion also plays a role in
Modifying Specific Properties: Appearance - Colorants, Pigments, Dyes, Special Ejfects
61
maintaining the physical properties of the compound, while inadequately mixed pigment may even damage the processing equipment. Dispersion of a critical pigment in a ^difficult' resin matrix may be promoted by special dispersant additives. Pigments are generally robust, but over-mixing can be as serious a problem as under-mixing. Stability of the pigment is an important factor. Many pigments can deteriorate when exposed to excessive heat and, where the matrix is an engineering thermoplastic, a pigment with higher thermal stability is needed, to resist the higher processing temperature. Generally, large-particle pigments, such as titanium dioxides, are easier to handle - but carbon blacks, by their very nature, demand specialist handling (and are usually compounded in dedicated sealed units). Organic pigments also have fairly large particles, but they tend to be light and 'fluffy', and may also carry electrostatic charges, all of which makes them difficult to disperse. Smallerparticle pigments provide a denser colour in the plastics matrix but their specific gravity can provide problems in metering/weighing. The sequence of blending, as well as the use of dispersing aids, is critical.
6.3 Replacement of Cadmium
Probably the main challenge to pigment development during the past 10 years has been the ecological drive to replace heavy metals which, it was feared, could leach out from landfills into the environment. Lead had already been phased out on the grounds of toxicity but, in Europe, there were national and supranational moves to ban the use of cadmium pigments also. The latest study (by the EU itself) concludes that cadmium pigments do not present any significant threat to human health or to the environment. A more far-reaching report on cadmium and cadmium oxide is expected. Technically it is not easy to produce an exact 'drop-in' replacement (especially at the same cost level). A key problem has been to produce a yellow that is as effective as cadmium. Economically there are also problems. Respondents to a survey by the Cadmium Association said that costs increased by 2-5 times: over 50% found that productivity fell by 10-25% when moving to non-cadmium pigments, particularly with polyolefins. Organic pigments are bringing their own strengths and weaknesses as they move into markets formerly held by cadmium and lead. In general they have excellent colour characteristics, but they can have lower stability, while increasing formulation costs. New pigments are being designed as blends of organic and inorganic compounds, using features of both to tailor to a specific application - but blends can retain weak properties from their individual constituents. The need to replace heavy metals has also stimulated the introduction of new chemistry. An important development has been that by Rhone-Poulenc of inorganic pigments based on sulphur, with a crystalline structure that can be doped with various metal elements (rare earths). The colour strength is reported
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to be 3 0 - 3 5 % lower than that of cadmium but the opacity and dispersion characteristics are comparable. All are characterized by excellent heat stability (up to 2 50°C), as well as having high resistance to weathering and UV light. Ciba has developed a range of yellow pigments based on bismuth vanadate (BVA) some of which resist up to 30()°C. This type of pigment is known for its liveliness and freshness of tint, but heat stability is at present insufficient relative to the cadmium yellows. BVA yellow pigments are mainly used in semicrystalline polyolefins (such as HDPE) since they do not show any phenomenon of warping. Another possible alternative to cadmium yellows, lead chromates, and diarylid yellows is yellow chromophtal HRP - a brilliant all-round pigment with very good heat and light stability, which can be used in PVC, polyolefins, styrenics, and polypropylene fibres. Clariant has added more than 50 colours to its cadmium-free Universal range, making a total of 180 colours. Special effects have been extended to include wood, pearlescence, and edge-glow effects. Colloids has also added 15 stock film grade colour masterbatches to its existing 35 colours to meet the restriction on heavy metals in the EC Directive on Waste Packaging, 94/62/EC, Article 1 1 . Table 6.2 Replacements for cadmium pigment masterbatches Product
Pigment concentration
High-temperature suitability
Contains cadmium pigment
Heat stability (°C)
Light stability
(%) Yellow
5 5--60 40
Yes No
Yes No
300 260-2 70
7-8 6-7
Cream
60 55
Yes Yes
Yes No
300 3{)()
7-8 7-8
Beige
65 65
Yes No
Yes No
300 260
7-8 7-8
Orange
60 40- -45
Yes No
Yes No
270
7-8 7
Red
50- -55 35
Yes No
Yes No
300 2 70
7-8 7
Blue
5 5--60 40
Yes Yes
No No
280 280
7-8 7-8
Green
60 45
Yes No
Yes No
280 2 70
7-8 7
Grey
60 50- -65
Yes Yes
No No
300 300
7-8 7-8
3(){)
Source: Colloids
6.4 Pigments for Special Effects
New pigment technology (which is largely concerned with light-scattering techniques) offers a very wide range of special effects.
Modifying Specific Properties: Appearance - Colorants, Pigments, Dyes, Special Effects 6.4.7 Aluminium
63
pigments
These offer effects such as bright metallic lustre, bright sparkle, pearlescent effects, and glitter. The pigments are entirely encapsulated by the polymer carrier, allowing easy and gentle dispersion. Dosage uses standard volumetric and gravimetric units, with little tendency to contaminate. A high metal content permits low dosage: 0.1-3% for moulded articles and up to 5% for film will provide good opacity. In engineering plastics a pigment content of 1-5% may produce a 5-15% reduction in strength, which may be offset by using a higher grade. Plastics coloured with aluminium can be recycled, and it is also possible to improve the appearance of recycled thermoplastics by the addition of aluminium pigments. Metallic pigments, especially for automobile applications such as bumpers, door panels, grips, buttons, hub covers, and scooter panels and wings, are a focal point of current development by Clariant Masterbatches Division. The company also claims it has the first colour masterbatch series for HDPE packaging with an anodized aluminium appearance, giving high reflectivity, chrome, and lustre. 6.4.2 Pearlescents
These are pigments based on thin platelets of transparent mica, coated with titanium dioxide or iron oxide, producing interference patterns. Titanium dioxide (Ti02)-coated mica pigments have a 2-10 )am particle size, for increased lustre, whiteness, and coverage; there are also silver sparkle effects. A two-tone effect can be obtained with absorption colours deposited directly on interference pigments of TiOi-coated mica (such as Mearlin Dynacolor). A 'frosty' effect can be obtained by combining pearlescent pigments with ultrafine titanium dioxide of 20 |im particle size, compared with the normal 200 |im, as a coating on the mica platelets The pigments (from Kemira Pigments) reflect different colours according to the angle of viewing. The coating strongly absorbs radiation in the UV part of the spectrum and shows most of its scattering power in the blue. TekPearLite colour concentrates give pearlescent effects: they include FDA-approved grades for cosmetics, toys, and food packaging. Colour and effect masterbatches have been developed by Hanna's subsidiary Victor International. They include a highly concentrated colour masterbatch (Hi-Strength) that can reduce inventory costs and is seen as particularly suitable for packaging where high opacity is required. There is also a new translucent pearl effect masterbatch range (Trans-Pearl) that includes thermochromic, marble, pearlescent, edge-glow, photochromic, laser marking, frosted, metallic, and speckled effects. 6.4.3 Light interference
pigments
These have recently been taken a stage further with the development of so-called 'flip-flop' pigments that present a different colour according to the angle from
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which the surface is viewed. This effect (which uses the same phenomenon as the wing of a butterfly or the shell of a beetle) is at present exploited mainly in special automobile topcoats, giving a car body that seems to change colour as it approaches and passes by. Considerable work on this technology has been carried out by BASF. A novel silicone polymer comprising a powder-like hquid crystal material is being developed by Wacker Chemie for the same effect. Helicone flakes make it possible to reproduce all shades within the spectrum, and also to produce shifts of colour as the viewing angle changes. So far, iridescent colours that shift with different angles and different substrates have been developed. Just four grades - copperred, gold, green, and blue - make it possible to reproduce all the shades within the spectrum. 6.4.4 Fluorescents
These have been developed in recent years, together with light-conducting pigment and dye systems, giving exciting possibilities, especially in display media. Luminescent solar concentration (LSC) units based on acrylic (PMMA) or polycarbonate (PC) sheets contain a fluorescent dye that collects daylight along the edge and can be used with photovoltaic cells, or to give increased visibility of printing in signs and signals. Some typical systems are BASF's Lumogen F range of fluorescent dyes, offering about eight years' resistance to UV light, and Hanna offers a full range of transparent fluorescent colours giving a light tint to flat transparent surfaces, scattering light and strong colour to the edges, and giving a surface-glow effect, used with GP styrenes, acrylics, and PC. 6.4.5 Thermae hromic and photochromic
pigments
These are micro-encapsulated liquid crystal systems, giving precise colour changes at specific temperatures, or when exposed to light. They are particularly interesting for packaging for food or pharmaceuticals, giving an indicator of storage or cooking state. Photochromic pigments change from colourless to highly coloured when exposed to UV light (such as sunlight) and revert when removed from radiation. They are organic, with excellent colouration in a wide range of polymers, and can be mixed to form a spectrum of colours or mixed with conventional dyes. Agricultural applications are particularly interesting, where use in 'polytunnels' can protect plants from over-exposure to ultraviolet and infra-red radiation. Other applications include sunglasses, security equipment, protective equipment such as welding helmets, and novelty products. Thermochromic pigments change colour with temperature, and there are compounds and masterbatches for injection, blow moulding, or extrusion. The pigments comply with FDA food contact regulations and can be used for novelty products and for products requiring warning indicators, such as baby bottles, thermometers, and kettles. Possible colour changes are: green to yellow, magenta to blue, and coloured to colourless. Typical ranges include Hanna/
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65
Victor's Chameleon organic pigment concentrate for polyolefins and styrenics, with colour changes activated in 10°C bands from - 2 5 to +58°C, and a range from Sibner Hegner, which changes from coloured to colourless at 5-15°C or 65-75°C. A breakthrough in photoluminescent concentrates is claimed by Ampacet, with the launch of four grades under the name Lumi. Based on a new concept that overcomes most of the limitations that have prevented widespread use of luminescent systems relying on radioactive elements, they demonstrate good hysteresis (enabling them to be charged and recharged many times without losing the ability to re-emit light) and retain their luminescence for several hours without exposure to a light source. They are highly heat stable (resisting temperatures above 300°C) and have good resistance to chemicals, but the most significant benefit is that they are non-toxic and non-radioactive, which opens the way to new application possibilities. A colour change that is triggered by light rather than heat has been introduced by Polycolour Plastics, with its new Dual Colour system. New longer-lasting phosphorescent pigment technology (activated with minimal light but then glowing for 2 0 - 3 0 minutes) has been introduced by Hanna Color (FX Nite Brite) which, with a proprietary laser marking system, will prove of great interest for applications such as emergency signalling and illuminated latches in automobiles. A series of innovative 'glow-in-the-dark' coloured compounds has also been introduced by RTF, offering designers a wider range of pastel colours (such as peach, pink, blue, cream, and green), for applications such as back fighting. 6.4.5.1 'Intelligent' heat proteetion for food products This is offered by a pigment system developed by Sachtleben Chemie, Germany. It can be incorporated in plastic films and food packaging, to control the temperature in heat-sensitive products. Visible light is kept away and heat may escape unhampered from the package. The product is said to be of interest for projects sponsored by the World Health Organization, aimed at prolonging the preservation of foodstuffs in developing countries, and for disaster relief operations. 6.4.5.2 High-performance dyes for CD manufacture These are offered by CMR Technology, Connecticut, USA, including CMR 1000 blended dye powder, a blend of dye powder and stabilizer (which requires only a single solvent, saving time and money). CMR claims to be the world's only independent source of dyes for CD-R and DVD-R and dye process technology. 6.4.5.3 Solar heat Epilin Heat Shield 900 is a dye that absorbs infra-red radiation while allowing transmission of visible fight, so blocking solar heat. It can be used in polycarbonate for automobile sunroofs and other glazing and can be added to polymer films for window and greenhouse film.
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6.5 Laser Marking
Demand for laser marking and, consequently, suitable colorants, is growing rapidly in packaging and technical products. Until comparatively recently it has been difficult to produce effective laser marking on plastics (such as for date/ batch-coding on packaged goods) but the development of suitable pigment systems has produced materials giving clearly contrasted marking on many types of plastics, no matter what the base colour. The effect is created by reaction both in the pigment and the polymer matrix and is irreversible. The pigments can be easily incorporated into existing formulations, with no major influence on the properties of the material, since they react at relatively low intensity in areas close to the surface of the moulded object. Transparent and naturally coloured plastics can be marked from light to dark without loss of transparency; light-coloured materials can be marked with sharp dark grey to black marking and contrasting colours from black to white can be applied to dark-coloured and black media. Pigments have been developed for both CO2 and Nd:YAG laser systems. Low pigment concentrations (from about 0.1%) provide dark marking and higher concentrations (up to 1.5%) show a light-coloured marking. Items can be marked at up to 6000 a minute (pulse CO2) and up to 2000 mm s~^ (Nd:YAG). A new pigment system that reacts to the laser beam itself, independent of the polymer matrix, is being developed by Merck, in addition to its present range of conventional laser marking pigments, based on mica coated with metal oxides such as selenium and ferric. A colourless energy-absorbing dye, compounded into a plastics material, or printed or painted on the surface, makes possible a novel laser welding technique, creating a joint that is almost invisible to the naked eye. Until now the normal practice has been to introduce an opaque absorber (usually carbon black) to act as the medium that heats in the laser beam to produce the weld. The new system, however, developed by the UK welding research association, TWI, Advanced Materials and Processes Department, permits two similar transparent plastics to be joined, with no visible weld line. The dye is Filtron, from Gentex, applied by painting or printing, compounding or inserted as a film.
6.6 Pigment Dispersants
Although desirable, organic pigments present problems because they are more resistant to breakdown and dispersion, with limited heat stability and less interaction with the matrix. No single dispersant has been able to correct this. Polyethylene and polypropylene waxes are used as carriers for pigments, but it has been difficult to ensure complete avoidance of agglomerates. AlliedSignal's Aclyn range of low molecular weight ionomer colour dispersants is claimed to offer improvements in division as well as wetting and
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distribution, aiding breakdown of any agglomerate in the pigment powder into smaller particles, preventing re-agglomeration by comprehensive wetting of the pigment surface. More intense colour can be obtained with the same pigment concentration that is heat stable to over 2()0°C and allowing high pigment loadings (as high as 70% for organic pigments). A new dispersion developed by Hiils (Vestowax P930 V) is claimed to produce increased colour strength in injection moulding and extrusion, allowing reduction in the pigment concentration used.
6.7 Multi-functional Systems
There is also a trend towards multi-functional pigment systems, such as CombiBatch concentrates from ReedSpectrum, which incorporate colour and functional additives. They can be used from PE to PET and include antiblocks, anti-static agents, flow modifiers, nucleating agents, and UV stabilizers. A new colour additive package from Morton (Injecta Color) includes lubricants and heat stabilizers, giving reduced cycle time without impairing colour and without warpage.
6.8 Pigments for Engineering Plastics
Increasing use of engineering plastics for Visible' applications, such as equipment housings, produce a demand for good colours that remain stable at higher processing temperatures. Yellow chromophtal GTAD (Ciba) is an anthraquinone-based material and is self-dispersing in resins and polyolefin fibres. Unlike classic pigments, it recrystallizes on return to ambient temperature and so offers a high thermal stability (up to 280°C). The pigment is also transparent and non-warping. A range of encapsulated heavy-metal-free single-pigment dispersions and custom colour matches that can be added at any point in the compounding process, developed by Holland Colors under the name Engineering Holcobatch, is claimed to improve the properties of filled (mainly glass-filled) plastics. Organic yellow, Bayplast Yellow G Y-5680 (Bayer), exhibits a unique spectral curve with heat stability and light fastness. It can be used with most thermoplastics, including polycarbonate and nylon (processing temperatures up to 320°C have been obtained). Cerdec's chrome titanate yellow is also recommended for engineering plastics, because of its above-average heat stability. A novel blue-shade red azo pigment, Engeltone 1115 (Engelhard), is an alternative to high-performance organics, complying with FDA limits for food contact and comparable in heat stability with many high-performance bright reds, such as DPPs (up to 300°C in ABS) - which it could replace, with up to 50% savings.
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6.9 The Effect of Pigments on Dimensions
A side-effect of replacing heavy-metal-containing inorganic pigments has been the need to accept organic alternatives that do not necessarily offer the same standard of performance. Pigments such as phthalocyanine blue and quinacridone red, for example, are less thermally stable and (although they cost less and offer excellent colouring ability and resistance to ageing) they have a reputation in the moulding industry as a cause of problems in shrinkage, warpage, and, occasionally, poor product performance. The UK National Physical Laboratory (NPL) has shown that phthalocyanine blue is an 'active' pigment, having a pronounced effect on the crystallization behaviour of semi-crystalline polyolefins, such as polyethylene and polypropylene. In effect, it acts as a nucleating agent, changing the temperature of crystallization and the nature of crystalline structures formed by the host polymer, as a result of heterogeneous nucleation. The shrinkage sensitivity of a compound appears to depend on the type of pigment used. Pigments affect dimensional stability: yellow 93 appears to cause most distortion but least shrinkage; a 15:3 modified blue pigment produces less out-ofplane distortion than other pigmented and unpigmented materials. Changes observed in crystallization behaviour, morphology, and anisotropic shrinkage in the pigmented compound are reflected in Young's modulus, yield stress, and failure strain (in the flow direction). Material ductility increases in HDPE, amplified in direct blending and impact performance using the falling weight method shows a statistically significant pigment/mix dependence. The research could be important for the packaging industry, where some problems have been encountered in tamper-proof bottle caps moulded in compounds using phthalocyanine blue. Table 6.3 Influence of pigment type on dimensional plates" Shrinkages
Shrinkages
Warpage W
Warpage W
Angle score
Yellow 62 Virgin Blue 15:3 (mod) Blue 15:3 Yellow 93
Virgin Yellow 62 Blue 15:3 (mod) Blue 15:3 Yellow 93
Yellow 62 Blue 15:3 Virgin Blue 15:3 (mod) Yellow 9 3
Yellow 62 Yellow 93 Blue 15:3 (mod) Blue 15:3 Virgin
Yellow 62 Blue 15:3 (mod) Blue 15:3 Yellow 93 Virgin
RW.
RWei
RWe2
RWe,
RWe4
Yellow 93 Blue 15:3 Yellow 62 Virgin Blue 15:3 (mod)
Yellow 62 Yellow 93 Blue 15:3 Virgin Blue 15:3 (mod)
Yellow 93 Blue 15:3 Yellow 62 Virgin Blue 15:3 (mod)
Yellow 93 Yellow 62 Blue 15:3 Virgin Blue 15:3 (mod)
Yellow 9 3 Blue 15:3 Yellow 62 Virgin Blue 15:3 (mod)
" Pigments are ranked in decreasing stability for both thick and thin order of importance, with those causing the most distortion at the top. Cells containing two or more pigments are equally ranked. Source: Polymers and Polymer Composites
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6.10 Colorants for Food and Medicals
Colorants are necessary materials in most forms of packaging, and they are critical to extraction and toxicity. This has been recognized from the beginning, and there are many pigments with satisfactory performance that are accepted for food-contact and medical applications.
6.11 Recent Developments
Technically, the development stress is now on high-performance pigments that also offer other properties, such as resistance to weathering, heat, light, and solvents, non-toxicity, and optical effects. The industry has been forced away from heavy-metal-containing inorganic pigments, leaving gaps that have only partly been filled by technical advances for mixed metal oxides. There have not been exact replacements matching the desired performance qualities in certain applications, such as anti-corrosive chromate-based primers. There is still a strong market in traditional materials, which will be replaced as technology introduces viable alternatives. 6.77.7 Colour
strength
BASF's range of azoic yellows (Paliotol) allows bright tints to be produced that are resistant to heat and light and suitable for food contact. Families of Paliotol yellows based on isoindoline and reds based on perylene can be used in polyolefins and also in the more technical plastics. From Engelhard is Meteor Plus 9384, which is claimed to have 70% greater colour strength than comparable reds (for use in PVCs, nylons, and engineering plastics). Also new is a barium-free yellow-shaded red, claimed to be less hygroscopic than barium products. New in the Microlen range are high-concentration pigment preparations based on polyolefins, giving good dispersion and suitability for automatic metering for masterbatch production, compounds, and colouring of elastomers. A new mixed-phase rutile yellow pigment (introduced by Bayer: Lightfast Yellow 62R) differs from conventional chrome rutile yellows in that it has higher tinting strength, better hiding power and gloss promotion, is suitable for lightfast, water-stable, and heat-stable pigmentation of plastics and coatings, satisfies purity requirements for food-contact applications. 6.77.2
Weathering
Cerdec Drakenfeld has introduced Yellow 10411, a yellow high tint strength chrome titanate, and 10411 greenish clean-shade for high-reduction PVC and polyolefins, and engineering plastics with above-average heat stability. Brown 10421, for rigid PVC, offers good weathering resistance and new black pigments also have high weathering resistance.
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BASF's Sicopal Yellow FK 42 3 7 FG is a heat-stable bismuth vanadate in a lowdusting form, designed for bright light weather-fast colours, especially in HDPE, ABS, and PA. Color-Chem International offers Amaplast Orange GXP, Red DJ, Violet PK, and Blue HB as new weather-resistant solvent dyes for engineering polymers, especially polyamides. They are claimed to offer better heat and light stability than existing solvent dyes and organic pigments, and good migration/ extraction resistance. 6.77.3 Natural effects
Customers are looking for products with a more 'natural' look, according to Hanna. Trend-setting applications now include white stone and earthenware (terracotta) effects, created for indoor and outdoor products, as well as 'wooden' chairs and tables. Building on its experience with fibres, beads, pearlescent, and fluorescent effects, the company has developed a range of natural effects. 6.77.4 New forms of pigment
Transforming the traditionally hard-to-use powder form of organic pigment into a unique microgranular form, Bayer's Coatings and Colorants Division has announced its new Bayplast Gran pigments, giving low dusting, high bulk density, and excellent dispersability in plastics and fibres. As well as contributing to a cleaner and safer environment, they also reduce waste, increase productivity, and provide more efficient shipping and storage. The process produces hollow microgranular spheres ranging from 150 to 175 |im, which contribute directly to high flow rate and low static cling. 6.77.5 Surface treatment
A surface treatment for organic pigments by Engelhard is said to contribute to lower volatile organic compound (VOC) levels, reduced costs, and improved performance. It also forms the basis for an improved naphthol red 170 organic pigment (Harshaw RX 3170). Holliday Pigments' Prestige R is pre-wetted to produce less dust, also increasing bulk density and boosting feed rates with volumetric feeders. Said to be the first time glass pigments have been offered coated with titanium dioxide, giving a brilliant star-like glitter, with depth and multiple colours, another range by Engelhard, under the name Firemist, offers exceptional chroma, colour purity, brightness, transparency, and reflectivity. 6.77.6 New pigment
chemistry
A family of organic pigments has been introduced by Ciba based on new colour chemistry, named diketo-pyrrolo-pyrrol (DPP). Chromophtal DPP products, ranging from yellow-shade to mid-shade red, are claimed to be the brightest, cleanest, and most opaque organic pigments available, offering bright, transparent
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colours with good durability and improved processing characteristics. They are heat stable to 2 70-285°C and can be used with polyolefins, PVC, polystyrene, and ABS, and can also be mixed with other pigments because they are inherently non-reactive. Isoxindigo is a new type of chemistry developed by Ciba Specialty Chemicals mainly for the engineering plastics market. Pure and brilliant shades of polymersoluble colorants, offering users new solutions, can be highly transparent, providing a broad scope of possibilities with very good fastness. They are also claimed to be very economical in use, giving good value both to processors and end-users for colouration of styrenics and engineering plastics. Unique resin technology is claimed to lie behind the introduction, by Elementis under its Tint-Ayd brand name, of a new range of colorants for all types of powder coatings, and new high-performance pigments for low- and zero-VOC waterborne coatings. It was developed covering a variety of types, including white epoxy/polyester, white polyester/triglycidyl isocyanurate (TGIC), and clear urethane/polyester. Differing from conventional phosphorescent pigments based on zinc sulphide or radioisotopes is a range based on strontium oxide aluminate chemistry, by Nemoto, Japan (LumiNova). Originally developed for watch and clock dials, they have many other applications, in appliances, sign boards, and emergency equipment, giving an afterglow period up to 10 times that of ZnS-based systems, activation by a wide wavelength band, up to 10 times greater initial afterglow brightness, and excellent weather and light fastness. For use in plastics, the preferred system is masterbatch or compound, as the pigment is a very hard substance with needle-like particles that are difficult to incorporate directly into a resin. For masterbatch, the processing temperature should be about 10°C higher than normal and the recommended machine configuration is one with a distributive screw design and twin hoppers, using the first to feed in resin and additives and the second to dose the pigment into the melt.
6.12 Market Trends
European consumption of pigments and colorants is estimated (by Rapra Technology) at about 728 000 tonnes in 1997, rising to nearly 900 000 tonnes in 2002. An estimate by BCC values the market at nearly US$ 1.4 billion. Production of colour compound is estimated at 1.5 million tonnes in Europe, mainly for cable and pipe grades and engineering resins. Demand is likely to slow down, in preference to coloured masterbatch. Pigmented masterbatches are used to modify an estimated 53% of polymers processed (and 45% of all performance additives used in Europe are incorporated via masterbatch). Compounder Ampacet estimates that worldwide consumption of masterbatch will reach 2.15 million tonnes in 2 0 0 1 . Film, blow moulding, and injection moulding make up about 70% of consumption. There are around 200 producers of colour masterbatch, the leaders being Cabot, Schulmann, Ampacet, and Ferro.
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Intertech estimates the world market for high-performance pigments at over 550 000 tonnes a year, and showing an annual growth rate of 5-7%. The main segments of the market are inks and paints (55%) and plastics (35%), with other applications sharing the remaining 10%.
CHAPTER 7 Modifying Specific Properties: Appearance - Black and White Pigmentation
Table 7.1 At a glance: white pigments Function
White pigmentation, high reflectance; modification of other colours, increased brightness
Properties affected
Appearance and surface; may also give higher UV protection to the plastic, improved weather resistance: some mineral whites will also improve mechanical properties
Materials/characteristics
Titanium dioxide; zinc sulphide; blanc fixe; white calcites
Disadvantages
Possible problems of handling in powder form, needing extra ventilation: titanium dioxide can act as photocatalyst, unless suitably treated
New developments
Improvement of presentation and dispersability: high-performance masterbatches with other additives
7.1 Types of White Pigment
7.7.7 Titanium
dioxide
Titanium dioxide (Ti02) is the most important white pigment used in the plastics industry. It has a higher refractive index than any other white pigment and has good chemical stability. It is also non-hazardous and possesses very good dispersability and good thermal stability. There are two commercially useful forms: rutile and anatase. Rutile has higher opacity and is considerably less photocatalytically active than anatase. It also has a slightly higher refractive index (2.70 as against 2.55), giving better light-scattering power. Rutile-type Ti02 also accepts surface treatments more readily, bonding better than anatase.
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Anatase is used mainly in paper and elastomers: in thermosetting resins systems, it retards gel time and may prevent cure altogether. The pigment is extracted from crude ore, removing impurities such as iron oxide. There are two manufacturing processes: Sulphate (46% of production, and declining): a multi-stage wet chemical process, batch or continuous. Titanium dioxide is dissolved in the raw materials by concentrated sulphuric acid, precipitating the hydrous salt. This is then calcined to produce one of the two crystalline forms, anatase orrutile. Chloride (54% of production, and rising): a two-stage process, at high temperature. Titanium ore is reacted with coke and chlorine to produce titanium tetrachloride. Purified titanium tetrachloride is then reacted with oxygen to produce rutile titanium dioxide. The chloride produced is recycled to the first stage. The process cannot produce commercial quantities of anatase. It is a more modern process and is considered preferable on environmental grounds.
7.1.1.1 Surface treatments Titanium dioxide absorbs much of the IJV radiation which would otherwise degrade a polymer matrix and so it also protects the polymer photochemically. Untreated, however, the pigment itself is photocatalytic. Although it converts most of the UV energy to heat, the remaining energy creates active or radical sites on the surface of the pigment particle. The reaction at these sites accelerates the breakdown of the surrounding polymer, leading to the well-known weathering effects of 'chalking' and loss of gloss. Virtually all titanium dioxide used in plastics pigmentation is surface treated. For use in PVC, the main purpose is to minimize photocatalytic activity but other effects should also be considered. On the negative side, high levels of surface treatment reduce the proportion of titanium dioxide in the pigment, thus significantly reducing opacity and tinting strength. However, by modifying the interfacial interactions between polymer and pigment, the treatment may also aid dispersion and reduce the requirements of power and shear when mixing. Especially for PVC, most Ti02 pigments also employ an organic coating, aiding the development of an optimal state of pigment dispersion and so ensuring that the maximum opacity and durability potential of the pigment is realized. The combination of inorganic and organic treatments determines whether the pigment is best suited to giving resistance to weathering and discolouration (for example, in UPVC window profiles) or to giving viscosity control and opacity (for example, in plastisols). The technology of treating titanium dioxide pigments is thus very complex. Property differences arise from the type, thickness, combination and method of application of surface treatment, as shown in the following:
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75
Table 7.2 Melt flow index of polycarbonate, pigmented with 5% Ti02 showing the eff"ect of various surface treatments Virgin resin RutileTi02, with Rutile Ti02, with Rutile Ti02, with Rutile Ti02, with RutileTi02, with
modified siloxane 0.5% alumina, 0.5% polyol 1 % alumina, 0.5% polyol 1% alumina, 0.5% siloxane 3.25*)^) alumina, 1.5% silica, 0.5% siloxane
11.4 13.2 21.5 2 5.3 2 3.7 2 5.2
Source: Kronos
The level of photocatalytic activity may be reduced by surface treatment of the base pigment with suitable inorganic compounds. For pigmentation of plastics, including PVC, these are usually alumina or a combination of alumina, silica, siloxane, and polyol, or sometimes zirconia. The treatments function mainly by placing a physical barrier between the pigment surface and the polymer matrix, blocking the active sites and minimizing degradation. The effectiveness of a particular surface treatment depends on several factors, including the type of chemical compounds used, the amount applied, uniformity of treatment, and density of coating on the pigment particle. The original surface treatment, which is still the most popular, is alumina. Among other inorganics, silica is used less frequently and zirconium rarely. Inorganics are usually added to improve properties of the end product, but they also enhance slightly the dispersion characteristics. In addition, by forming a barrier between the titanium dioxide and the matrix resin, they inhibit undesirable chemical reactions. Organic surface treatments are, most often, polyols. Amines, siloxanes, and phosphated fatty acids are also used. Organics generally act as aids to processing and dispersion, promoting de-agglomeration, wetting, and dispersion of the pigment. All the major effects of organic treatments are concentrated on the surface of the particle and the figure for percentage composition usually indicates the amount on the surface. Alumina (aluminium oxide). This is used at levels from 0.5 to 3.5%, applied during manufacturing. It is compatible with all main resin systems, but can give problems by outgassing of its water of crystallization at elevated temperatures, the water vapour remaining as a 'pocket' in the melt and finished product. In thin films this causes voids (known as 'lacing'). When processing at above 250-300°C it is recommended to use particles with 0.5% alumina or below. Silica (silicon dioxide). This is used with alumina to improve the weathering resistance of certain grades of titanium dioxide (as for PVC rigid compounds for outdoor applications). The alumina and silica together form a surface impermeable to UV light, preventing pigment/matrix reactions that are triggered by exposure to UV light.
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Polyols and amines. These enhance wetting and dispersion in almost all polymer systems, giving broadly the same results (but polyol treatments are possibly better with vinyl compounds). Siloxanes. These give about the same performance as polyols and special grades are effective in retarding undesirable reactions in polycarbonates. In excessive proportions, however (above about 1%), siloxanes can separate from the Ti02 and migrate to the surface, affecting printability and sealing characteristics. 7.7.7.2 Titanium dioxide grades A typical range of grades includes: • • • • • •
Stabilized, surface-treated micronized rutile, chloride process. This gives the highest weather stability in resin systems, especially PVC and polyolefins; good dispersability, brightness, and tinting strength. Stabilized, surface-treated micronized rutile. This has good weather stability and very good dispersability, especially in PVC. Stabilized, surface-treated micronized rutile. This has very good photochemical stability and dispersability in aqueous systems; good for urea and melamine moulding compounds and rigid PVC. Surface-treated micronized rutile. This gives brilliant shades in colour compounds, high tinting strength, and good dispersability; good economic value; weather stability limited in PVC with lead stabilizers. Surface-treated micronized anatase. This has high tinting strength, bluish colour tone, outstanding brightness, and dispersability. It is less abrasive than rutile pigments, but not recommended for outdoor applications. Untreated micronized anatase. This has very good brightness, bluish colour tone, high tinting strength, and good dispersability in aqueous systems.
7.1.1.3 Opacity and tinting strength Key criteria for all pigments (and particularly whites) are opacity and tinting strength. Opacity is particularly important in thin-section applications, where a highly opaque pigment can serve well, even at a lower concentration. In thicker sections it may be less important - but it is as well to remember the other side of the coin: lower concentrations of Ti02 pigment may detract from durability. Tinting strength measures how well a given amount of pigment affects the overall colouring of the moulded product. With Ti02 this means how well it lightens a coloured compound, or adds whiteness and brightness to a white system. This is important not only in white compounds but also in compounds where the colouring influence of other additives must be masked. With titanium dioxide, the development of opacity and tinting strength depends on light-scattering power, which is governed by refractive index, particle size distribution, Ti02 content, and dispersion in the polymer.
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77
The greater the difference between the refractive index of the pigment and its surrounding medium, the higher the light-scattering power, and therefore the opacity and tinting strength. Control of particle size distribution is critical if the maximum opacity potential of Ti02 is to be realized. For the most efficient light scattering, the particle diameter should be about 50% of the wavelength of the Ught to be scattered. So, some grades of Ti02 pigments are produced to maximize the number of particles in the range 0.20-0.40 jam, which is approximately half the 4 0 0 - 7 0 0 nm range of the visible light spectrum. The effect on properties of particle size distribution of titanium dioxide is: • •
0.2-0.4 |im: particles develop opacity 0.4-1.0 jim: particles affect durability
The actual Ti02 content of a pigment is an important factor in the opacity developed by a specific pigment. Typical grades have a content of 8 8-9 7%. Good dispersion is also a key criterion in developing high opacity and tinting strength. Maximum values will be developed only if the number of aggregates and agglomerates is few (and those that are present are well distributed throughout the polymer matrix). Undertone is the term used to describe the influence of a Ti02 pigment on the colour of a tinted system, resulting from the small differences in the proportion of light scattered at different wavelengths in the visible spectrum. Differences in undertone are less apparent in white compounds than in tinted compounds. Undertone is usually expressed as the difference between the red and blue reflectance, normalized against the green reflectance, as measured in a grey tint: Undertone = — where Rr = red reflectance, R\j = blue reflectance, and Kg = green reflectance. The more negative is this value, the bluer will be the undertone of the pigment. The undertone may also be expressed as a CIE b-value measurement in a standard grey flexible compound, and compared with the b-value of a standard Ti02 in the same system. Undertone is a function of pigment particle size. Ti02 pigments with an average particle size of close to 0.20 )Lim impart a bluer undertone to thick sections than do pigments of a larger particle size. Larger particle sizes give a more neutral or yellow undertone. But for thin, translucent items the appearance of colour arises from the transmitted light, and the effect of particle size is reversed: for bluer transmitted light, larger particle sizes, neutral or yellow undertone products, are selected. When colour matching tinted compounds, it is usually necessary to use a titanium dioxide with the correct undertone - although compensation for small differences can sometimes be made by adjusting the tinting system.
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Additives for Plastics Handbook
7J. 1.4 Colour Pure titanium dioxide scatters all wavelengths of visible light uniformly, and therefore appears as brilliant white in a colourless plastic. Pigment colour is essentially dependent on purity, so maximizing the potential for producing a brilliant white. 7.7.2 Zinc
sulphide
Zinc sulphide (ZnS) offers a good alternative to Ti02 pigments, where these cause technical problems. Pigments have various concentrations of barium sulphate, characterized by high brightness and very good light stability. ZnS pigments absorb less UV radiation than Ti02 pigments. They therefore have a wider UV 'window', giving the highest efficiency of optical brightener: fluorescent additives also retain their effectiveness, giving a brilliant appearance, and photoinitiators in UV-curable paints remain effective when pigmented with zinc sulphide. Tinting strength depends on ZnS content. Micronized grades are easily and homogeneously dispersed in plastic compounds. Particle size is 0.3 )Lim (regarded as optimum for a sophisticated white pigment). Because of low Mohs hardness, ZnS pigments cause virtually no wear on moulds and do not impair the mechanical strength of fibre-reinforced plastics (in contrast to abrasive pigments such as Ti02). Their main applications are in thermosetting compounds, glass fibre-reinforced thermosets and thermoplastics, and polyolefins. Table 7.3 Comparison of the hardness of pigments Mineral
Mohs hardness rating
Diamond
10
Corundum
9
Topaz
8
Quartz
7
-silicate
6
-phosphate
5
Fluorspar
4
Limestone
3
Rock salt
2
Talc
1
Pigment
Titanium dioxide (rutile) Titanium dioxide (anatase)
Barium sulphate, zinc sulphide
Source: Sachtlehen
Compared with rutile titanium dioxide, zinc sulphide offers white pigments for plastics that are non-abrasive, catalytically inactive, dry lubricants. They can reduce friction, polymer decomposition, and the wear of processing equipment.
Modifying Specific Properties: Appearance - Black and White Pigmentation
79
Uncoated and surface-treated (HDS) grades are available, to improve dispersion. The micronized grades in particular are easy to disperse and are suitable for dissolver grinding. Low oil absorption (13 compared with about 20 for titanium dioxide) allows higher loadings while maintaining good rheological behaviour and improved flow properties of pigment pastes. Good dielectric properties make the pigments particularly suitable for electrical and insulation applications. Table 7.4 Zinc sulphide compared with titanium dioxide for glass-reinforced thermoplastics Compound
Concentration
(%)
Retention of original values (%) Tensile strength
Izod impact
Gardner impact
TiO,
ZnS
TiO,
ZnS
Ti02
ZnS
Polyamide 66, 30% glass
0.05 0.50 1.00 2.00
89 84 83 81
86 86 82 87
72 60 60 60
100 100 100 100
68 69 59 56
100 100 100 100
Polycarbonate, 10% glass
0.05 0.50 1.00 2.00
83 83 83 81
96 95 92 91
73 73 73 63
90 90 77 73
100 100 100 100
100 100 100 100
Polypropylene, 30% glass
0.05 0.50 1.00 2.00
94 89 86 85
100 100 100 100
92 83 83 67
68 68 68 65
96 100 100 lOO
100 100 100 100
Polystyrene. 20% glass
0.05 0.50 1.00 2.00
98 98 99 100
85 87 93 100
84 100 100 100
69 73 76 78
85 100 100 100
85 87 90 93
SAN. 20% glass
0.05 0.50 1.00 2.00
95 92 91 89
100 100 100 100
60 56 55 50
82 87 75 70
100 100 100 100
92 95 100 100
ZnS pigments are characterized by low binder requirement, good rheological properties, resistance to flocculation, and suppression of floating. They also have good anti-corrosion properties, and can be compared with zinc phosphate pigments. In some cases, ageing resistance can be improved. Weather stability is very good in polyamides and melamine compounds, but limited in most other plastics. Partial substitution of Ti02 pigments with double the quantity of ZnS does not impair brightness, pigment dispersion, or melt flow index of a masterbatch, but reduces friction and abrasion and increases temperature stability. It can thus act as a processing aid, especially in linear LDPE. The pigments are, for all practicable purposes, free of heavy metals: they are hsted in the US FDA Code of Federal Register (Part 178) and meet the pigments Recommendation IX of the German Federal Health Ministry (EGA), but not the French Circulaire No. 176 (dated 2 December 1959), which sets a maximum limit of 0.2% for acid-soluble zinc.
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Additives for Plastics Handbook
7.13 Other white pigments and extenders
A number of other fine-particle minerals offer very good whiteness properties and dispersability and can often be used as extenders to titanium dioxide, reducing the overall cost. 7.1.3.1 Aluminium silicates Fine-particle aluminium silicates (kaolin) have a high specific surface and low grit content and are easily dispersible in plastics, increasing the hardness and elasticity. Mechanical properties are generally lower than with the more coarse fillers. Thermo-optic treated grades have high whiteness and can be used to extend titanium dioxide and other more costly pigments. Calcined kaolins have good electrical properties, low compression set, and low water absorption, for use in cable formulations. 7.1.3.2 Barium sulphate (/blanc fixe') Precipitated barium sulphate ('blanc fixe') is an inert white filler, resistant to acid and alkalis, and has very good weathering resistance. It does not absorb light from the ultraviolet to the infra-red range and so does not impair the briUiance of colour pigments. Particle sizes range from 0.7 to 3.0 |im. DispersabiUty and lack of grit are high: hardness and stiffness of plastics are improved without effect on surface quality (especially gloss and colour brilliance). It is also used to increase density and X-ray opacity, especially for toys and medical articles, and improves sound insulation values. Special grades increase light scattering without absorption in semi-opaque compounds such as lampshades, PC and PMMA sheets, and PVC film. Ultrafine particle grades (less than 0.2 jim) have been developed as nucleating agents for partially crystallized thermoplastics. Natural barium sulphates (barytes) are inert and allow very high loadings: fine-particle grades are preferred to increase the density of a plastics compound, while coarse particles are better for acoustic applications, especially in automobiles. Blanc fixe micro is a white inorganic powder for plastics and coatings, comprising barium and sulphate. It is practically insoluble in water, organic solvents, and acids/alkalis. It is produced from barytes, with removal of impurities, achieving a narrowly defined particle size distribution. Titanium dioxide production technology is used for finishing. Its particles are almost as fine as those of titanium dioxide pigments (barytes, 4 |am; synthetic barium sulphate, 3 |im; blanc fixe micro,0.7 |im; titanium dioxide,0.3 \xxn). In use it is notable for low binder replacement, ready dispersability, extreme fineness, low agglomerate content, and (in coatings) high gloss. It can also act as a 'spacer' between white or coloured pigments, potentially reducing titanium dioxide by 5-15%, or reducing pigment costs, or raising solids content. Cost can be reduced by about 5% without detriment to properties. 7.1.3.3 Calcium silicate A needle-like, non-toxic calcium silicate (wollastonite) is used to reinforce thermoplastic and thermosetting resins. Various grades, with and without
Modifying Specific Properties: Appearance - Black and White Pigmentation
81
organic surface coating, are available. Wollastonite also has interesting properties as a reinforcing filler and is expected to become more widely used in future. 7.1.3.4 Magnesium silicate Very pure, white platelet magnesium silicate (talc) is used to reinforce and nucleate partially crystalline thermoplastics, especially polypropylene and polyamide. It is used more as a reinforcement, giving good stiffness and dimensional stability. Table 7.5 Properties of white pigments and fillers Surface modified
Relative tint reduction^ (approx.)
pH value (approx.)
Density
Weather resistance
Light fastness
Titanium dioxides Rutile chloride
Al203Si02org.
102
8
4.0
Very good
Rutile
Al2O3SiO.org.
90
8
4.0
Good
Rutile
AI2O 38102
90
7
4.0
Good
Rutile Anatase Anatase
AbOiOrg. Al203org.
102 87 85
8 8 8
4.1 3.9 3.9
Moderate Fair Fair
Very good Very good Very good Good Moderate Fair
Type
VAnc sulphates Micronized ZnS normal 60% 30% Micronized 30%
org. D:org. D: org. org.
62 55 37 24
7 6-7 7 8
4.0 4.0 4.2 4.3
Fair^ Fair^ Fair^^ Fair^
Good^ Good^ Good^ Good^
D: org.
22
7
4.3
Fair^
Good^'
9
4.4
Very good
9
4.4
Very good
Very good Very good
Barium sulphates 1.0-3.0 |Am
—
Micronized
org.
Other materials Barytes
-
-
7-10
4.0-4.3
Very good
Kaolin
-
-
5
2.6
Very good
Talc
-
-
9
2.8
Very good
Wollastonite
-
-
10
2.9
Good
"
Very good Very good Very good Good
^ In PVC according to DIN 53 775, with 0.025% carbon black and 3% pigment (ref pigment standard Ti02 = 100). ^ Depends on system: very good in polyamides and melamine/formaldehyde moulding compounds. Source: Sachtleben
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Additives for Plastics Handbook
7.1.4 White
masterbatch
White masterbatch is produced typically with 50-75% additives, for let-down at 3-4% (film), 1-2% (universal grades), and 3% (blow and injection moulding). Table 7.6 Typical grades of white masterbatch Base polymer
Colour index pigment
Recommended applications
(%) 50
White 6
50
White 6, blue 29
High pigment concentration, for extrusion and injection moulding High pigment concentration, for sheet extrusion, moulding
70
White 6, white 18
75 60 60
White 6. white 15 White 6, 18, blue 29 White 6
75
White 6, white 18
70
White 6, white 18
70
White 6. white 18
50
White 6
Economic masterbatch for injection moulding and film requiring anti-blocking Blow moulding, injection moulding, film Blued white for blow moulding, extrusion High-quality thin-gauge film, especially suitable for HDPE film Medium-gauge film, where good anti-blocking is needed Economic masterbatch for film, moulding, extrusion Low-cost masterbatch for film extrusion, moulding High-quality thin-gauge film
Polypropylene
50 60
White 6 White 6. white 18
Injection moulding polypropylene Sheet and pipe extrusion polypropylene
Universal
75
White 6, white I 8
75
White 6
60 60
White 6, blue 29 White 6 plus optical brightener
Injection moulding; disperses well in polyolefins, styrenics and engineering polymers Injection moulding; disperses well in polyolefins, styrenics, and engineering polymers Injection moulding, multi-purpose High pigment concentration, for sheet extrusion, moulding
60
White 6
Additive
Polystyrene
Polyethylene
Polyamide
High pigment concentration, for polyamide extrusion and injection moulding
Source: Colloids
7.1.5 New
developments
A novel process for producing ultrafine particles of titanium dioxide, which are optically transparent but retain their opacity to ultraviolet radiation, has been developed by DuPont. Based on work of its speciality chemicals group, it is a
Modifying Specific Properties: Appearance - Black and White Pigmentation
83
hydrothermal process using amino titanium oxalate as the precursor, which differs from other such processes by producing exclusively rutile particles, instead of a mixture of Ti02 phases, such as rutile and anatase. It does not require additional calcination stages, which are expensive and may also produce agglomerates, impairing the transparency of the Ti02 particles. Particles made by the process have a uniform size distribution of less than 100 nm. They could be used in plastics food packaging, coatings, and automotive clearcoats, and in many other sectors vulnerable to UV light. The company has also introduced Ti02 pigments with outstanding optical and rheological performance at masterbatch loadings up to 80% pigment/20% resin (Ti-Pure), to meet a worldwide trend towards highly loaded masterbatches. A new generation of Ti02 concentrates, giving brighter colours with exceptional hiding power (50, 70, 80%), has been introduced by Ampacet, aimed at cast film and extrusion coating, heat stable at 343°C. TST/200 is a new series of highly loaded white concentrates for high-temperature/high-speed extrusion coating and cast film. It has good pigment dispersion, reduced die build-up, lower moisture pickup, bluest undertone, and is compatible with a wide range of polyolefin let-down resins. A 60% white concentrate gives better rheology, whiteness, dispersion, and screen life in blown film, cast film, and extrusion coating, with all ingredients acceptable for food contact in North America. White PE MB9 is a 50% titanium dioxide concentrate in LDPE with similar food-contact acceptability, giving high opacity in film and coating, particularly for resins with melt indices higher than 5. Ampacet has also introduced a range of controlled rheology white masterbatch (11989-1), for blown and cast film and extrusion coating. New masterbatches for Dow's new Affinity polyolefins have been introduced, plus a new generation of EBS-based anti-slip/anti-block masterbatch, for high EVA content resins. Surface-treated Ti02 (TiOna, from SCM Chemicals), has an organic surface treatment which is said to give superior colour and processing stability with easy dispersion at high concentrations. It is particularly designed for polyolefins, but there is also a grade for PVC. New from Schulmann is the NG range of white film masterbatches, designed to minimize lip deposits. A Ti02 grade especially for use in masterbatches for production of film and flexible packaging, resisting die build-up, has been introduced by Tioxide under the name Tioxide TR2 7. Intended for high technical performance at the most extreme temperatures necessary for high throughput in production of thinner film, it has been designed to minimize emission of volatiles, so significantly reducing problems such as die build-up and (in extreme cases) lacing. Ease of dispersion into the polymer matrix results in significantly higher levels of throughput. Other advantages include high levels of brightness, colour, and opacity. A new white from Cabot is Plaswite PE7474, to help overcome die deposit in white film production. MFI is l l g (10 min)~^ at 2.16 kg/190°C, giving easy dilution. It is formulated to be compatible with a wide range of polyethylenes, either pre-blended or added direct at the hopper.
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Additives for Plastics Handbook
7.2 Black Pigments Table 7.7 At a glance: black pigments Function
Black pigmentation, high absorption of light
Properties affected
Colour; carbon black also has useful anti-static properties, can provide electrical conductivity; black pigments also give effective UV screening; also used as a reinforcement in rubber compounds (the largest overall use)
Materials/characteristics
Carbon black: different types according to manufacturing process, giving a wide range of particle sizes and shapes, governing the application. Black antimony sulphide is interesting as it is also a flame retardant
Disadvantages
High potential to contaminate other materials/equipment unless kept separate or used in dust-free/non-polluting form
New developments
Improvement in stability, dispersability; forms for easier use/faster mixing; large use of masterbatch forms
7.2.7 Types of carbon black
Carbon black might be described as an ideal universal additive: it can provide pigmentation, reinforcement, ultraviolet shielding, and anti-static properties but always provided that the final colour is black. It is used in several different forms, produced by different production processes for its various applications. There are about 100 different grades today, each of which is matched to an individual application. In thermosetting resins, most carbon blacks tend to inhibit cure and should be avoided. The major user of black is the rubber industry, particularly for tyres, where addition of carbon black contributes to reinforcement and resistance to tearing, abrasion, flex, and fatigue. In the USA it is estimated that a little less than 0.5 lb (0.25 kg) of black on average is used for every 1 lb of rubber used. Plastics are the largest and fastest-growing non-elastomer use for carbon black. A number of production processes are used, of which furnace black is by far the dominant process, accounting now for 9 7 - 9 8 % of total world production (of approximately 6 million tonnes a year). Production processes come under two main classifications: • •
thermal oxidative decomposition (furnace black, Degussa gas black, lampblack, from coal tar or petrochemical-based aromatic oils, natural gas, and coal tar distillates); and thermal decomposition (thermal black and acetylene black, using natural gas or oils, and acetylene; an electric arc process has been used in the past but is no longer commercially significant).
Modifying Specific Properties: Appearance - Black and White Pigmentation
85
7.2.1.1 Thermal oxidative decomposition processes Furnace black is the newest but also overwhelmingly the predominant process. Liquid feedstock is atomized, sprayed into a flame inside a ceramic-lined furnace, and then quenched, cooled, and filtered. The process offers technical and economic advantages, with the facility to produce a wide range of types, with adjustment of particle size and specific surface area. Particle aggregation can also be controlled by addition of very small amounts of an alkali metal salt. Particle size ranges from 10 to 100 [im. Black made by this process has a very low bulk density and is difficult to handle in this form. It is therefore pelletized or further densified. Wet-pelleting enables carbon black to be converted with water
Typical Performance Properties of Carbon Blacks
rger
Particle Size & Properties
A
^^R Higher
Structure & Properties
lighter
Masstone
• darker
higher
V'isc<)slty
weaker
Ttntiiig Strength
• stronger
lower
Ivcuiding
• higher
bluer
Tinting I'ndertone
• browner
easier
Dispcrsabiiity
• harder
* lower
lower
Vbcosity
• higher
lower
(iloss
• higher
easier
Dispersability
• harder
higher
Conductivity
• lower
lower
IJV protection
• higher
slightly weaker; Colour bluer
Large Size, Low Structure Lowest Viscosity Highest Loading
Large Size, High Structure Easiest to Disperse Weakest Colour
Small Size, Low Structure Most Difficult to Disperse Strongest Cofour
Small Size, High Structure Highest Viscosity Lowest Loading
• slightly stronger; browner
Figure 7.1. Diagram of carbon black molecules illustrates how the size and structure influence the processing and properties. (Illustration: Cabot Corporation)
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Additives for Plastics Handbook
to spherical pellets: the majority of carbon blacks are processed this way, especially grades for the rubber industry. For pigments, blacks are densified and packaged as carbon black powder, or are dry-pelletized. The gas black (channel black) process, based on gas feedstock, was originally developed in the USA using natural gas, but is now obsolete. As natural gas was not readily available in Europe at the time (in the mid-1930s), a similar process using coal tar distillates was developed by Degussa, known as the gas black process, and this is still operated. Gas is burned in large numbers of small flames, impinging on water-cooled rollers, depositing carbon black on the rollers and also in the air. The black from the two streams is combined. The process is flexible, producing particle sizes from 10 to 30 jiim, but the structure cannot readily be controlled. The carbon blacks resulting are highly rated as pigments for their efficient dispersion properties and high colour depth. The blacks react as distinctly acidic in an aqueous solution, due to surface groups containing oxygen, which can be increased by oxidative aftertreatment, making grades that are particularly useful in coatings and printing inks. The lampblack process is one of the oldest commercial processes, in which the fuel is burned in a pan beneath a fume hood lined with refractory bricks and cooled: process gases containing carbon black are cooled and filtered. The process is used today for standard grades of pigment and rubber black: they have coarse primary particles and broad distribution of sizes from 60 to over 200 jim. Despite development of alternatives, it has not yet been possible to replace these grades in their specific applications. 7.2.1.2 Thermal decomposition processes The thermal black process is discontinuous, using natural gas or higher hydrocarbons and oils. A unit consists of two reactors one of which is heated in cycles of 5-8 minutes with fuel and air, while the other is heated with fuel without air, giving alternating heating and decomposition cycles. Actual formation of the carbon black occurs more slowly in the absence of oxygen and at a decreasing temperature, giving large, solid particles with a coarse particle size, ranging from 120 to 200 jim or from 300 to 500 |im, depending on whether the natural gas is diluted with inert gases. The acetylene black process relies on the exothermic decomposition of acetylene into carbon and hydrogen at elevated temperatures, the heat released sustaining the reaction. Acetylene blacks have average particles sizes in the 3 0 40 jLim range, but the particle shape is more branched than the spherical shape of thermal blacks. 7.2.1.3 Effect of particle size and structure on properties of carbon blacks The size of a particle and its shape (structure) have a fundamental effect on the properties of the particular type of carbon black, particularly the colour strength, dispersability, and electrical conductivity. The basic effect of higher/lower particle size and structure on the properties of carbon black is illustrated in Table 7.8.
Modifying Specific Properties: Appearance - Black and White Pigmentation
87
Table 7.8 Effects of changing particle size or structure on specific peoperties of carbon blaclc Particle size
Tint depth Tint strength Tone Oil adsorption/viscosity Dispersability Electrical conductivity
6())im
13 |am
More grey Weaker More blue Lower Easier Lower
Darker Stronger More brown Higher More difficult Higher
Structure
Oil adsorption/viscosity Black concentration Dispersability Gloss Electrical conductivity Colour
Low
High
Lower Higher More difficult Higher Lower Stronger/more brown
Higher Lower Easier Weaker Higher Weaker/blue
Source: Cabot Corporation
When these influences are combined, the effect of a combination of particle size and structure are as shown in Table 7.9. Table 7.9 Effects of changing botti particle size and structure on specific peoperties of carbon blacli Particle size
Structure Low
High
Large
Lowest viscosity; highest carbon black concentration; lowest electrical conductivity
Easiest dispersability; lowest tint strength; bluest colour tone
Small
Most difficult dispersability; strongest colour; brownest colour tone
Highest viscosity; lowest carbon black concentration; highest electrical conductivity
Source: Cabot Corporation
7.2.1.4 Testing for properties: structure - effect and determination Using an electron microscope, carbon black can be seen to be a variety of chained or cluster-like branched aggregates of approximately spherical primary particles, with an overall diameter of 1 0 - 5 0 0 )im. Specific surface area (m^ g ^). smaller primary particles have a larger specific surface area. If it were possible to form a string of primary carbon black particles
88
Additives for Plastics Handbook
from the Earth to the Sun, the total weight would be about 1 g. The specific surface area is normally determined by iodine adsorption, and is stated in m^ g~^. With pre-dried samples, this is a quick and simple method. However, both surface groups and adsorbed PAHs influence the method and it is therefore important that volatile content is below 1.5% and toluene extract below 0.25%. The method is limited to furnace blacks and lampblacks. It is not usually stated for pigment blacks, but it is possible to avoid this limitation if the black is heated to 950°C in the absence of air, before determination. DBP absorption. Only indirect methods are available for determination of the structure, the best known of which is DBP absorption. In this method, dibutyl phthalate (DBP) is added drop by drop to a certain amount of carbon black, placed in a calibrated kneading machine. During this titration, the torque exerted by the kneading machine is registered, on the principle that when all voids between the carbon black aggregates have been filled with DBP the surface will have been wetted, which will be reflected in a change in torque. From the amount of DBP required to achieve this stage, it is possible to determine the degree of aggregation of the black. The higher the DBP absorption (in ml (100 g)~^), the higher is the structure of the carbon black. However, the structure of the carbon black in its normal pelletized state is made up of two components: the primary (or permanent) structure, as formed in the reactor when the primary particles fuse to form aggregates, which is regarded as indestructible; and a secondary (or temporary) structure formed by weak agglomeration of the primary aggregates, which can easily be destroyed by the forces of mixing and processing. To take this into account, the so-called 24M4 or 'crushed' DBP absorption methods are used, in which the sample of black is mechanically pressed four times under a specified pressure, before normal DBP measurement. Values are lower than DBP numbers of the pelletized material and the difference between the two is often referred to as the 'delta' DBP. Oil absorption. This is also used to characterize pigment blacks. Carbon black is ground into linseed oil and the oil absorption is the maximum amount of oil permitting a non-deliquescent cone to be formed from the mixture. This test gives information more relevant to production of paints. Nitrogen surface area. This is based on covering the surface with nitrogen, a molecule of which has a known space requirement, and which can readily be converted to m^ g"^. The smaller nitrogen molecule can also penetrate pores and surface imperfections inside the carbon black particle. Geometrical surface area. This can be determined from particle size, by measurement of particle size, determination of distribution curves, and calculation of surface area values, with the aid of an electron microscope. Although of fundamental importance, this method is too time consuming for production of characteristic data for everyday use.
Modifying Specific Properties: Appearance - Black and White Pigmentation
89
Cetyl trimethyl ammonium bromide (CTAB). This has a greater space requirement than nitrogen and the CTAB number most closely approaches the determination of geometrical surface area (the surface without pores), correlating well with primary particle size. Tint strength. This represents a coloristic parameter, determined in comparison with a white pigment (zinc oxide). As it is influenced by particle size, distribution, and structure (the smaller the particle size, the higher the tint strength value), tint strength also offers an indirect measure of surface area or particle size. A low structure gives a higher tint strength value. Care must therefore be exercised when relating tint strength to the reinforcing potential of the black, since increasing the surface area and the structure both influence the tint strength, but in opposite directions. Consequently it is possible to have two carbon blacks with the same tint strength but with significantly different reinforcing potentials. Jetness. This is a measure of 'blackness', expressed as a value (My). When carbon black is ground in linseed oil, a practised eye can distinguish up to 100 different levels of carbon black. Technical measurement techniques can also detect slight residual reflections. The current test uses a spectrophotometer. The smaller the particle size, the higher the My value. Table 7.10 Variations in carbon black produced by different processes'* Unit
Nitrogen surface area Iodine adsorption Particle size DBP absorption Oil absorption Jetness (My) Tinting strength Volatile content pH^
Thermo-oxidative decomposition
Thermal decomposi tion
Lampblack
Degussa gas black
Furnace black
Thermal black
Acetylene black
m^g-^
16-24
90-500
15-450
6-15
~65
mgg-^ nm ml (100 g)-^ g(100g)-i
23-33 110-120 100-120 250-400 200-220 25-35 1.0-2.5 6-9
NA 10-30 NA 220-1100 230-300 90-130 4.0-24 4-6
15-450 10-80 40-200 200-500 210-2 70 60-130 0.5-6 6-10
6-10 120-500 37-43 65-90 170-190 -20 0.5-1.0 7-9
~100 32-42 150-200 400-500 225 NA 0.5-2.0 5-8
%
•^ NA = not applicable. ^ In the case of oxidised carbon blacks, pH may fall as low as 2. Source: Degussa
722
Other black
pigments
Black antimony sulphide (Anzon) has a strong black colour and is of interest as a pigment in plastics such as PE, polyesters, and PVC. It also confers flameretardant properties. It comes as a pulverized treated ore (as a soft powder) or as a chemically precipitated sulphide (as a dried filter cake). Materials have a
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Additives for Plastics Handbook
trisulphide or stibnite structure. It has a fine particle size and high infra-red reflectance. A novel approach is a reactive black liquid colorant (by Milliken Chemical), claimed to bridge the cost/performance gap between polymeric colorants and pigment when producing black polyurethane parts. Reactint Black X95A/B has been developed for most nonflexible PU applications: it is a polyol, reacting with isocyanate to produce a polyurethane and thus offers advantages against solid black dispersions. It can be used in most reaction injection moulded (RIM) or semi-rigid automotive parts, including bumpers, door panels, and steering wheels. It does not settle out and has a colour strength factor 4 - 6 times stronger than a typical solid carbon black dispersion. It reduces equipment wear and cleaning and will not absorb or interfere with catalysts used in the PU process. Clean up is easy as the material is water soluble. 7.2.3 Black masterbatch
To meet demand from compounders for higher loadings of carbon black in colour concentrates, new grades of black are being developed to allow higher loading without the penalty of increased viscosity. The trend towards higher loading is related to the issue of concentrate purity. For ease of processing, carbon blacks are usually compounded with a carrier resin in masterbatches which are then let down into the base resin. Higher loading decreases the amount of carrier resin required which, in turn, increases the concentration of the desired resin and performance of the end product. But the traditional drawback is increased viscosity. Black masterbatch is produced typically with 2 5-50% loading, for let-down at ratios from 1-2 to 3-6%, depending on grade and application. Table 7.11 Typical grades of black masterbatch (universal) Black Colour Nigrometer MFIlO.Skg content value of index atl9{)°C (%) black
Bulk density (gl ')
Application
50
118
74
5
6 50
50 40
50 92
96 87
10 5
700 700
40
120
74
5
680
50
125
73
1
700
50 40
92 92
87 87
10 5
700 700
50
120
74
1
700
High jetness and colour strength: forABS.PS.andPP Ceneral purpose, economical colouring High colour strength, superior surface gloss, good compatibility with a wide range of polymers High jet black with good flow properties, particularly suitable for moulding Highest jetness and colour strength: superior compatibility with ABS and PS Good colour strength Economical masterbatch: particularly suitable for compounding Superior jetness and colour strength
Source: Colloids
Modifying Specific Properties: Appearance - Black and White Pigmentation 7.2.4 Recent
91
developments
New pigment blacks have been developed by Degussa for improved processing and cost reduction. A pigment black, Colcolor E 60R, is a substitute for pigment black at the usual 10-20% chalk content often used as an extender for economical masterbatches: the resulting strength also makes it effective in recycling that requires black over-colouring. An improved flow concentrate, Colcolor UNI 51, preserves the desirable properties of grade UNI 50 and optimizes others, with good colour depth and coverage, using polymeric binders rather than fillers and extenders. Improved distribution is featured and improved flow behaviour has a positive effect on re-dilution. Printex Alpha (for films, fibres, tubes, and cable sheathing) gives optimized dispersability and improved moisture absorption, while Printex 12 is claimed to be an economical low-colour furnace black for injection moulding and recycfing plastics. A micro-granular formulation, combining the advantages of a free-flowing, nearly dust-free state with high pigment concentration (95%), easy dispersabiUty, and economy has been introduced by Brockhues under the name Granufin Carbon P95. Suitable especially for rigid and flexible PVC compounding, it contains only a smafl percentage of wetting and dispersing agents. New Cabot grades include a universal black masterbatch (Plasblak) for PS, ABS, SAN, and PVC, said to have improved dispersion and a new furnace black for semiconducting shielding of medium voltage power cables (Black Pearls) which prolongs life and improves processability. Black Pearls 800 has the ash level reduced from over 0.245% to lower than 0.1%, for engineering resins, improving dispersion and processability; and Black Pearls 3 700 is an extra-clean furnace black, showing smoothness and processing characteristics in semiconducting shields comparable with more costly acetylene blacks. Elftex TP ultra-clean carbon black is designed for pipe, cable jacketing, and fibres, giving a much lower pressure drop when the compound is extruded through a screen pack. A range of special carbon-based masterbatches has been developed by Hubron: • •
•
Black Fibre - for staple and continuous tape and fibre extrusion, characterized by a very high level of dispersion, with a carbon black content of 30-40%. Black Silk - for polyethylene film in technically demanding applications calling for superior dispersion, dilution at high additions, and downgauging with good opacity and UV protection. For best UV protection, it contains carbon black of 20-2 5 nm particle size at 40% content, and ingredients meeting European food contact requirements. Black Tek - for engineering plastics, where it is often unsuitable to use universal carrier systems. The grades are polymer specific (nylon 6, polycarbonate, styrene/acrylonitrile, and acetal), using a jet black grade at loadings from 10 to 30%, givingmouldings with jetness and gloss.
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A low-cost replacement for carbon black petroleum-based products has been introduced by DJ Enterprises: a custom-ground, high-purity metallurgical carbon, superheated to drive off organic 'tramp' elements. A non-marking black masterbatch, for moulding components of domestic appliances such as vacuum cleaners, which will not leave marks on walls or furniture, has been introduced by DuPont.
7.3 Commercial Trends: Titanium Dioxide
Following a number of important acquisitions, a major restructuring of the titanium dioxide industry worldwide has been taking place. The biggest deal in the industry was the fusion of the first- and second-largest producers by the purchase by DuPont of ICI's Tioxide business outside the USA, increasing the world leader's market share from 21 to 35%. The world number three manufacturer. Millennium, acquired the number nine producer, Thann et Mulhouse, and Kerr McGee moved into fourth place by buying 80% of Bayer's Ti02 business, which was the number eight producer. The three developments involved the transfer of nearly 800 000 tonnes a year of production capacity. Still to come (in the opinion of observers) is the repurchase of Tioxide's US assets by NL Industries (which sold its Rheox subsidiary to raise US$460 million for the deal) and a restructuring of the Ti02 industry in Japan, which is the logical conclusion of the recent sale by Ishihara Sangyo of its US agrochemicals business, for US$500 million. Also significant is the fact that both Millennium and Kerr McGee are divesting themselves of other activities, to concentrate on titanium dioxide.
7.4 Commercial Trends: Carbon Black
World production of carbon black accelerated from a growth rate of 1.8% a year in 1 9 8 7 - 1 9 9 6 to 3% a year during 1 9 9 6 - 2 0 0 1 . By the year 2 0 0 1 , total world production will be 7.8 million tonnes, according to a new forecast from Freedonia Group. Use of carbon black as a reinforcement in rubber tyres and other products will account for 94% of the total demand (including 68% for tyres), but special grades for use in plastics, printing inks, and paints, will make up the most rapid growth, commanding considerably higher values per kilogram than commodity furnace blacks. Demand for special carbon black will continue to be dominated by applications in plastics and printing inks, which account for 75% of this sector. The largest gains will be in the Asia Pacific region, mainly due to the development of the tyre industry in China. But the financial crises in Asian countries will depress growth to below the earlier projections. Markets in North America will continue to expand, while Western Europe and Japan will show modest gains as they recover from a 'low' in the first half of the 1990s.
CHAPTER 8 Modifying Specific Properties: Resistance to Heat - Heat Stabilizers
Table 8.1 At a glance: heat stabilizers Function
Used to prevent oxidation of plastics by heat, especially during processing but also in application; widely used in PVC compounds. Heat stabilizers act by stopping oxidation, or by attacking the decomposed products of oxidation.
Properties affected
Stability during processing; resistance to thermal breakdown of component under mechanical stress or loading; retention of colour, transparency.
Materials
Metallic salts: lead; combinations of barium, cadmium, zinc; organotin compounds. Hindered phenolics, secondary aromatic amines (primary anti-oxidants). Phosphites/phosphonites, thioethers, soya-based epoxies (secondary anti-oxidants). Synergistic combinations of these.
Disadvantages
No serious drawbacks: stabilizers have been around so long, they have become an accepted part of the process; lead and cadmium systems are being replaced in response to environmental pressure.
New developments
Multi-functional stabilizer systems, development of synergistic reactions, improved retention of colour and transparency, more convenient forms for handling; replacement of heavy metal compounds.
8.1 How They Work
Organic stabilizers can react with molecular oxygen in a process called autoxidation, initiated by heat, light (high-energy radiation), mechanical stress, catalyst residues, or reaction with impurities, to form alkyl radicals. The free radicals can, in turn, react to cause the polymer to degrade, causing embrittlement, melt flow instability, loss of tensile properties, and discolouration. Oxidation can be slowed by chain-breaking anti-oxidants, to reduce rate of propagation, or preventative anti-oxidants, which prevent initial formation of free radicals. Antioxidants deactivate the sites by decomposing the hydroperoxide or by terminating the free radical reaction.
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Because of its structure, PVC is particularly sensitive to heat and is by far the largest user of heat stabilizers. Other vulnerable polymers are chlorinated polyethylene and PVC/ABS blends. The increasing use of engineering plastics in applications involving prolonged exposure to heat also calls for special stabilizer systems. Another important growth area for heat stabilizers is recycled materials, where they will be used increasingly in inhibiting degradation and secondly in re-stabilizing post-use plastics waste. There are many different stabilizer systems for plastics, depending on the type and products of oxidation. Metallic salts were originally used to stabilize PVC, the most common being based on barium, cadmium, lead, or zinc, often mixed together to obtain a synergistic effect. Organometallic compounds are also used, mainly based on tin. A third group is non-metallic organic stabilizers, in which phosphites play an important role, improving transparency, initial colour, and light fastness. Epoxies (particularly derivatives of soya bean oil) are also used, acting also as plasticizers, for non-toxic products. Traditional stabilizer systems for polyolefins are based on a combination of a phenolic anti-oxidant and a phosphorus-based melt processing stabilizer, the phenolic providing melt processing stability as a donor of hydrogen atoms and a scavenger of free radicals, and a level of thermal stability. The phosphorus-based additive functions as a hydroperoxide decomposer during the melt compounding stage. For applications in contact with food, FDA and EGA regulations recommend liquid anti-oxidants based on vitamin E. These have been developed as patented systems and also open up new areas of application in polyolefins and polyurethane foam systems. Development in recent years has centred on technical improvement of the product, and easier handling and dispersion. The main technical objectives have been more durable effect at lower dosage levels, with good retention of colour and transparency when required. Improvement of toxicological properties, for food-contact and medical applications, has also been a continuing aim of developers. For improved handling, pelletized and liquid systems have been introduced, and there is a general trend towards greater use of masterbatch. The most expensive stabilizers are organotin stabilizers. Lead compounds are the cheapest. Liquid stabilizers can be lubricating or non-lubricating and can contribute to colour and/or volatility, firstly throughout the process and subsequently in the finished product. They include barium/cadmium (zinc), barium/zinc, and calcium/zinc in technical and low-toxicity grades and stabilizer/activator combinations. Liquid barium/cadmium/zinc has been used for many years for the most demanding outdoor applications, such as coil coating. Antioxidants are frequently recommended as part of a multi-component package to help achieve the best possible protection against photodegradation. Chemistries include: phenolics - highly efficient; ABS - good FDA approval; phenolic/phosphite blends - exceptional resistance to discoloration; thioesters exceptional heat stabilization in blend/synergy with phenolics.
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95
Table 8.2 Polymer heat stabilizers: selection guide
ABS
X
X
Fibres Polyamide Polyesters Polyethylene Polypropylene Polystyrene Polyurethane
x x x x x x x
x x x x x x x
PVC
X
Elastomers
x
x x x X
X
x
Key: A, hindered phenolic anti-oxidants; B, phosphite anti-oxidants; C, thio anti-oxidants. Source: Great Lakes Chemical
8.2 Antioxidants
Antioxidants fall into two classes, according to their mechanism in interrupting the degradation process: (i) chain-terminating primary anti-oxidants; and (ii) hydroperoxide-decomposing secondary anti-oxidants. It is possible to use more than one type of anti-oxidant, producing a desired result by different routes. Synergism between two stabilizers can often produce better results than a single system at the same concentration and, in polymers such as polyethylene and polypropylene, the total effect of synergism can be to improve efficiency of the anti-oxidant by up to 200%. 8.2.1 Primary
anti-oxidants
Primary anti-oxidants react rapidly and are termed ^radical scavengers'. The most important are sterically hindered phenolics and secondary aromatic amines. Hindered phenolics are high molecular weight anti-oxidants for polymer systems that are sensitive to thermal and oxidative degradation, due to formation of free radicals and peroxides. They protects against degradation at high processing temperatures and are highly efficient, low in volatility, and nonstaining, with wide toxicological clearance and are effective at very low dosages (0.01-0.1%). The efficiency can be enhanced by using them with other antioxidants, such as phosphites and thioesters, producing synergistic effects for effective and economical formulations. They are normally available as freeflowing powders, but 50% aqueous dispersions are also available. There is a trend towards non-dusting products, including pelletized solids and liquids. They are used in low- and high-density polyethylene (especially carbon blackfilled grades for pipe and copper cable insulation), polypropylene (especially hot water applications), high-impact polystyrene, ABS and MBS, and polyamides. They can also be added to PVC plasticizers (in which they can be dissolved) to
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inhibit oxidative degradation and embrittlement of PVC wire and cable insulation. They are losing ground in their use in PU foam because of volatility, as the use of non-CFC blowing agents requires higher processing temperatures. 8.2.2 Secondary
anti-oxidants
Secondary anti-oxidants react with hydroperoxides to produce non-radical products and are therefore often termed 'hydroperoxide decomposers'. They differ from primary phenols and amines in that they are decomposed by reaction with hydroperoxide, rather than containing it. They are particularly useful in synergistic combinations with primary anti-oxidants. Systems that do not contain a phenolic can provide good colour stability and gas-fade resistance, which are important properties in polypropylene fibres and other applications. A breakthrough was claimed by Ciba with FS Systems, the first of which was based on a new hydroxylamine, a high molecular weight compound offering outstanding compatibility with polypropylene, which functions through several different stabilization mechanisms to give both processing and long-term thermal ageing stability. Phosphite/phosphonites are generally regarded as the most effective stabilizers during processing, protecting both the polymer and the primary anti-oxidant. Hydrolytically stable phosphites are the most frequently used processing stabilizer in high-performance additive systems. Recent developments include systems with better colour fidelity and handling properties. Dover's Doverphos HiPure 4 and 4-HR are high-purity trisnonylphenyl phosphite (TNPP) processing and heat stabilizers, claimed to reduce overall costs. With 0.1% residual nonyl phenol, they are FDA-approved for food-contact applications and also used in medicals, colour-critical polyolefins, and styrenic block copolymers. They are effective also in acrylics, elastomers, nylon, polycarbonate, polyurethanes, polystyrene, PVC, ABS, and PET. Hydrolytic stability in apphcations such as food-contact packaging and medical devices is afforded by Doverphos S9228, which is claimed to offer better colour and stability than 2,4-di-t-butylphenyl phosphite, and also to function as an effective secondary anti-oxidant in combination with hindered phenols. Based on its pentaerythritol diphosphite technology, it can be used as a stabilizer for non-olefinic polymers, including PET, PBT, polycarbonate, and nylons. A solid phosphite anti-oxidant has been developed, introduced by GE Specialty Chemicals, in its Ultranox range. Designed to meet the demand for a highactivity stabilizer with superior hydrocarbon stability and improved handling characteristics, it is based on butyl ethyl propane diol chemistry, rather than the usual pentaerythritol. It has been granted FDA approval for food contact in certain applications and is expected to find applications in polyolefins, styrenics, PVC, engineering thermoplastics, elastomers, and adhesives. New stabilizer technologies based on phosphorus and other high-performance chemistries, to achieve better cost effectiveness, are under development by GE Specialty Chemicals. A general-purpose phosphite, Ultranox 668, complements
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97
the high-performance Ultranox 626 and 641 grades. It gives better processing both with polypropylene and polyethylene, including reduced screen plugging (a problem in fibre production, when molten polymer goes through fine screen packs in the extruder and leaves some impurities behind). It also virtually eliminates the problem of film build-up on the die-lip of the extruder.
8.3 Blends
Blends of primary anti-oxidants and a high-temperature hydrolytically stable organophosphite secondary anti-oxidant have been developed for hightemperature processing of polyolefins, polyamides, and polycarbonates in colour-critical applications. Irganox LM blends of primary anti-oxidants and a new phosphite processing stabilizer offer melting at 90°C and can be applied to polymer reactor products, especially polyolefins, linear polyesters, polycarbonates, polyamides, HIPS, ABS, SAN, and elastomers. Liquid blended systems (such as GE's Weston blends of trisnonylphenyl phosphite and octadecyl-3.5-di-i-butyl-4-hydrozyhydrocinnamate) reduce the number of feeders required and eliminate on-site mixing, reduce loss from dusting, and give more accurate feeding ratios. Thioesters increase long-term stability in conjunction with phenolic antioxidants. Their use is limited to applications where possible effects on odour or taste and negative interaction with HALSs (hindered amine light stabilizers) are not important.
8.4 Replacement of Heavy Metals
Environmental concern has promoted the development of systems to replace lead (especially from cables and cellular products). Cadmium-based stabilizers are also being phased out. To achieve the same effect, however, the replacements have to be complicated mixtures of salts. Organotin and calcium/zinc systems are favoured at present, but much will depend on the shape of any legislation in the future. In general, alternatives based on calcium and zinc are less effective, but are cheaper than those based on aluminium or magnesium. Water absorption can be a problem with systems not using heavy metals. In the USA, OSHA issued a Notice of Proposed Rulemaking, significantly reducing the permissible exposure limits for cadmium, pending a new risk assessment study on lead toxicity. In the meantime, individual states have passed their own laws restricting the use of cadmium and lead. In Europe, after introducing increasing restrictions on the use of cadmium over the last 20 years, the latest study concludes that cadmium pigments (at least) do not present any significant threat to human health or to the environment, but it is unlikely that there will be any dramatic reversal of the legislation.
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Typical systems include: • • • • •
zinc stabilizers are preferred for automotive applications, giving lowfogging, odour-free, long-term heat stability; non-toxic calcium/zinc has been used for many years in food-approved plasticized products such as blown packaging film and in toys and medical products; barium/zinc is used for plastisol processing, with a wide range of grades covering most semi-rigid and plasticized applications; metal soaps (liquid): barium/zinc, calcium/zinc (including pastes), barium/cadmium/zinc, and barium/cadmium; metal soaps (singles): stearates, laureates, myristates, barium, calcium, lead, and zinc.
8.4.1 Organotins Much interest has centred recently on organotin systems. The main materials and their key features include: • • • • •
butyl tin mercaptides: excellent for technical applications and have proved satisfactory in PVC processing for many years; butyl tin carboxylates: give excellent light and weathering stability; mixtures of tin mercaptides and tin carboxylates: may be used to replace pure carboxylates and are best used in extrusion of rigid PVC; liquid octyl tin mercaptides: approved in many countries for food packaging based on rigid PVC; methyl tins: used for extrusion, injection moulding, and calendering, where high thermostability is required.
Methyl tin stabilizers are used to improve the performance of colour development during processing, and to add strength and stability to PVC products. They can be used in the production of rigid PVC exterior building products such as window profiles, fencing, and siding, and also in bottles, calendered sheet, pipe, and injection moulded fittings. Performance comparable with lead, together with greater thermal stability, better weathering than CaZn, and improved processability is claimed by Elf Atochem for an organo tin, ThermolitePA24()(). Solid tin maleate stabilizers developed by Elf Atochem are claimed to give benefits in outstanding weathering properties without the previous difficulties of stickiness leading to difficulty in processing and chemical structure leading to low intrinsic thermal stabilizing effects. The originality of sulphur-free tin stabilizers comes from their specific oligomeric structure and use of high molecular weight maleic esters. As a consequence, formation of volatile maleic esters is avoided during processing. The high molecular weight of the stabilizer itself provides good self-lubrication and simple combinations of lubricants can be used.
Modifying Specific Properties: Resistance to Heat - Heat Stabilizers
99
Table 8.3 Stabilizer systems in different PVC applications Application UnplasticizedPVC (PVC-U) Pipe Injection moulding Profile extrusion Sheet Film Bottles PlasticizedPVC(PVC-P) Cable Coatings Imitation leather Profiles
Pb
Ba/Cd/Pb
Ba/Zn
+++ ++ +++ ++
Ca/Zn
Zn
+
+ + ++ +4+++ +
+ + ++
+++ ++ ++ ++ ++
+ + + + +
Source: Henkel/Sidobre Sinnova/Plastiques Modernes et Elastomeres
Table 8.4 Extrusion compound for window profiles; comparison between a classical lead formulation and tin maleate (Thermolite 4 1 0 )
S-PVCK67 TiOi pigment CaCO 5 filler Acrylic impact modifier Acrylic processing aid Thermolite 410 Calcium stearate Fatty ester, internal lubricant 0-PE wax, external lubricant Lead one-pack
Tin maleate formulation (Thermolite 410)
Lead formulation (standard one-pack)
100 4 5 7 1
100 4 5 7 1
6.5
Source: ElfAtochem
8.5 Effect of Silica on the Activity of Stabilizers
Silica is one of the most widely used inorganic additives in polyolefin compounds. The role it plays is constrained by its surface properties and, when stabilizers are present, they may be chemisorbed or physisorbed to the silica surface, restricting their mobility and reducing their role of inhibiting degradation reactions. Additives grafted to polymers have often been found to be less effective than their
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unrestricted counterparts and the individual properties of silicas (such as particle size, pore and surface morphology, Bronsted and Lewis acid sites, and adsorption behaviour) may be important in defining such behaviour. Silica enhances the crystallinity of a polymer (and hence reduces clarity) during ageing, by acting as a nucleating agent. This is moderated, however, when the stabilizers are bound to the silica. Distinct differences in the stabilization performance of anti-oxidants and HALSs when pre-bound to silica are attributed to the ability of the stabilizers to desorb selectively, depending on the environmental conditions.
8.6 Benzoxazolone Derivatives for PVC
Derivatives of benzoxazolone may provide useful heat stabilizers for PVC. During the thermal breakdown of PVC, the stabilizing effect of benzoxazolone can be observed in a reduction in an overall concentration of polyenes in the macromolecules, an increase in the induction period of formation of hydrogen chloride, and a reduction in the dehydrochlorination rate of the PVC. When N-methacryloylbenzoxazolone is introduced, the temperature at which thermal breakdown commences is raised by about 30-4()°C from the unstabilized compound. This compares with an increase of only about 1()°C when calcium stearate is used as the stabilizer. Experiments with other derivatives indicate that salts of benzoxazolone derivatives raise the thermo-oxidative decomposition temperature by about 15°C, depending on the nature of the metal of the salt and the presence of substituents in their molecules. Sodium and cobalt salts raise the level by about 2()°C. The stabilizing action of sodium and cobalt salts seems to be due to inhibition of free radical breakdown of the PVC by acceptance of the HCl formed, and replacement of the labile chlorine atom of PVC by benzoxazolone groups. Copolymerization of vinyl chloride with unsaturated benzoxazolone derivatives produces a copolymer belonging to the class of self-stabilized polymers. In comparison with PVC, these copolymers have increased thermooxidative stability. The maximum effect of stabilization is gained at a content of up to 2 mol%.
8.7 New Chemistry for Stabilizers
8.7.1 Lactone
chemistry
During oxidation of a polymer, carbon-centred free radicals are generated that react rapidly with oxygen to form peroxy radicals, which may further react with the polymer chains, leading to formation of hydroperoxides. These decompose, yielding highly active alkoxy and hydroxy radicals - which in turn produce new
Modifying Specific Properties: Resistance to Heat - Heat Stabilizers
101
carbon-centred polymeric radicals. The ideal anti-oxidant system should be capable of interrupting the oxidation cycle at each degradation step. For special applications synergistic combinations of hindered amines and dialkylhydroxylamine can be used, in which the latter acts as a radical trap. The accepted system has been binary blends of selected sterically hindered phenolics (primary) and phosphites (secondary), but none of these is a carbon-centred radical scavenger. In 1997 Ciba introduced a lactone stabilizer, HP-136, which functions as a carbon-centred radical scavenger, inhibiting autoxidation as soon as it starts and capable of regenerating phenolic anti-oxidants, so providing additional stability during processing and long-term use. The technology is based on a combination of a high-performance phosphite or phosphonite processing stabilizer and a hindered phenolic anti-oxidant, offering an improved cost/ performance profile compared with traditional two-component systems based on a phosphite/phosphonite and a phenolic anti-oxidant. The addition of HP-136 to the classic binary phenol/phosphite systems significantly improves performance both in melt flow and colour, enabling a producer and converter to tailor the formulation to meet specific cost targets. In some cases it is possible to reduce the concentration of the classic binary system by more than 50%. In combination with high-performance phosphites there is also a dramatic improvement, with significant reductions in overall concentration of stabilizer without loss of performance. In polypropylene tape applications, HP-136 is very effective when used with a classic phenolic or in a ternary blend and, compared with a traditional binary blend, data indicate that there is potential for a 50% reduction in total stabilizer concentration, with comparable melt flow stability, improvement in colour, and an improvement in water carry-over, again providing a significant margin for optimization of formulation. In polypropylene fibre applications, a combination of HP-136 with a hindered amine and a phosphite shows melt flow and colour comparable with a traditional binary system, but superior gas-fade resistance and UV stability in phenol-free blends. This improvement is seen at 40% less concentration. Irganox HP makes it possible to process at higher temperatures (above 300°C) than is possible with conventional anti-oxidant systems. It also permits as much as 50% reduction in overall additive loading, giving an attractive cost/ performance profile and potential for improved additive compatibility. New HP-136 blends can also make a major contribution to stabilizing polyurethane foams. In the drive to meet the lower use of CFCs required in the Montreal Protocol, higher concentrations of water are used as a blowing agent in production of slabstock foam. This gives a more exothermic reaction, with greater risk of scorch, resulting in loss in quality of the foam. The use of flame retardants in polyols can lead to higher discolouration in FR foams. The new blends provide excellent scorch resistance both in conventional and flame-retarded foams, with reduction in discolouration, so permitting producers to develop BHT-free formulations, and thereby lower the potential for discolouration of textile fabrics, while improving the thermal stability of the foam.
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Table 8.5 Flexible PUR foam scorch evaluation: delta E after microwave test^ Antoxidant (ppm) AO-4 hindered phenol
A0-3aminic AO
4000 4000 2000 4500
1000 1000 2000
HP-136
-
-
-
500 500 1000 500 300
4500 4000 1500 1600
3000 3200
Foam core colour, delta E
28.3 (noFR) 61.5 (with FR) 53.3 28.4 12.7 16.5 13.3 14.0
^ Flame retardant system: Antiblaze AB-lOO chlorinated phosphate ester (5 wt%); total additive concentration 0.5% for all formulations: only first entry contains no FR.
Table 8.6 Effect of the structure of HAS on the colour strength of a compound HAS in concentrate with pigment blue 15:1
Delta E of plaque" versus reference*^
HAS molecular weight distribution
HAS 3 HAS 3 HAS 5 HAS 6
12 0.5 0.3 15
Broad Narrow Narrow Broad
>NH, 2° >NCH3.3° >NH. 2° >NH. 2°
'' All plaques contain 0.25% HAS and 0.30% pigment in PP homopolymer prepared from a concentrate containing 12.5% HAS and 15% pigment. ^ Reference contains pigment only - no hindered amine stabilizer (HAS). Source: Ciha Specialtij Chemicals
8.72 Vitamin E
There has been much interest in stabiUzers based on vitamin E, which, in its bioactive form, is a-tocopherol. For applications in contact with food, FDA and BGA regulations recommend Uquid anti-oxidants based on vitamin E. These have been developed as patented systems and also open up new areas of appUcation in polyolefins and polyurethane foam systems. It is said to be highly efficient in small concentrations (100-300 ppm), especially with polyolefins. The effectiveness is due to the ability of the stabilizer and its major transformation products to deactivate all damaging free radicals. Problems of polymer discolouration can be minimized by the use of co-additives, such as phosphite anti-oxidants. For medical applications in particular, Ciba has turned to vitamin E, with a version for plastics under the trade name Ciba Irganox E, following an agreement with Roche to use its Ronotec raw materials. Vitamin E, or a-tocopherol, is a fully substituted aromatic chromanol with a phenolic group situated para to the oxygen of the chroman ring. This molecular configuration allows it to act as an extremely effective scavenger of free radicals, either alone or with a phosphite,
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103
giving better performance and economics than a typical phenolic. It can be used effectively almost universally, in polyolefins, PVC and engineering thermoplastics, polyurethanes, elastomers, and adhesives. It is classified as Generally Recognized as Safe (GRAS) by the US Food and Drug Administration when used as an anti-oxidant, and it is approved for use worldwide in foodcontact applications.
8.8 Recent Developments
Development in recent years has centred on technical improvement of the product, and easier handling and dispersion. The main technical objectives have been more durable effect at lower dosage levels, with good retention of colour and transparency when required. Improvement of toxicological properties, for food-contact and medical applications, has also been a continuing aim of developers. For improved handling, pelletized and liquid systems have been introduced, and there is a general trend towards greater use of masterbatch. The most expensive stabilizers are organotins. Lead compounds are the cheapest. Phosphite/phosphonites are generally regarded as the most effective stabilizers during processing, protecting both the polymer and the primary anti-oxidant. Hydrolytically stable phosphites are the most frequently used processing stabilizer in high-performance additive systems. Among recent developments are systems with better colour fidelity and handling properties. Dover's Doverphos HiPure 4 is a high-purity tris-nonylphenyl phosphite (TNPP) processing and heat stabilizer, which is claimed to reduce overall costs. With 0.1% residual nonyl phenol, it is FDA-approved for food-contact applications and is also used in medicals, colour-critical polyolefins and styrenic block copolymers. It is effective also in acrylics, elastomers, nylon, polycarbonate, polyurethanes, polystyrene, PVC, ABS, and PET. A soUd phosphite anti-oxidant has been developed by GE Specialty Chemicals, in its Ultranox range. Designed to meet the demand for a high-activity stabilizer with superior hydrocarbon stability and improved handling characteristics, it is based on butyl ethyl propane diol chemistry, rather than the usual pentaerythritol. It has been granted FDA approval for food contact in certain applications and is expected to find applications in polyolefins, styrenics, PVC, engineering thermoplastics, elastomers, and adhesives. 8.8.1 Pipes and fittings
Offering a better alternative for metal-free stabilization, a stabilizer system for pipes and fittings has been developed by CK Witco. It uses solid multi-component blends based on a patented organic molecule, and acts synergistically with costabilizers for good initial colour and long-term heat stability. The performance and broad processability (such as a retarded cross-linking behaviour compared with existing systems) is unique. The organic core components act as colour improvers due to their heterocyclic structure with highly nucleophilic reaction
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sites. They act at a very early stage in the PVC degradation mechanism, providing a new mode of action that explains the special properties and advantages of the system. 8.8.2 Foamed pipe
Chemson reports that its additive systems for foamed core pipe production have reached a stage at which they will permit recycled material to be incorporated, without any trade-off in terms of quality. The company suggests that, for a foamed core pipe plant with an output of about 350 kg per hour, the savings in materials costs could run to a six-digit amount during a year. Multi-layer technology for pipes has been on the market for about one and a half years and has been widely accepted for extrusion of large-diameter pipe for sewer ducts. Today, virtually no pipe of this type is produced without a core of foamed PVC between the inner and outer skins. The three-layer structure, in which the central core constitutes about 60% of the total material, reduces the weight of the pipe by about one-third, compared with conventional technology for production of a pipe of the same diameter. The blowing agent is nitrogen, directly metered into the machine as azodicarbonamide. 8.8.3 Cable
insulation
Developed for PVC cable insulation compounds, Akcros has developed a special CaZn-based system under the Interlite name, especially for formulations containing flame-retardant additives, many of which are known to have detrimental effects on properties such as initial stability and ageing performance. Included is a grade for formulations containing phosphorus-based plasticizers, developed with Akzo Nobel's Phosflex range. A new stabilizer generation for wire and cable has been introduced in the Mark EZ range, including grades with high thermostability comparable with commercial lead systems and better than calcium/zinc stabilizers, mainly for insulation in medium- and high-performance cables and in low-performance cables where good water absorption is required. Ageing properties are comparable with commercial products, with comparable results in Congored value and mechanical properties, plus flame retardancy. Mark EZ 760 is also a universal product that can be used in transparent cables, at up to 4 phr dosage. 8.8.4 Medical
products
A formulation for clear, flexible PVC compounds for medical products by Teknor Apex Plastics, Rhode Island, USA, allows processors to run at higher output, with less downtime because of the need to change the filter screen packs on the extruder. The key feature of the new system is that, unlike conventional FDAapproved stabilizers for medical applications, increasing the addition level does not reduce the resistance of the compound to sterilization by gamma rays. Resin degradation is also reduced (at 180°C, the time to onset of degradation is
Modifying Specific Properties: Resistance to Heat - Heat Stabilizers
105
extended from a normal 29 to 46 minutes) and retention of colour after radiation is also a little better. Barlocher has patented a stabilizer based on calcium/aluminium hydroxyphosphite, which is claimed to be an environmentally friendly raw material superior to all other known systems in external applications.
8.9 Other Stabilizers
Other stabilizers include special zincs for plasticized applications such as cable and organics added to calcium/zinc or used for pipe extrusion and co-stabilizers for metal soap and tin, improving long-term heat stability. ^Kickers' (liquid barium/zinc and potassium/zinc) are PVC stabilizers that catalyse the decomposition of a blowing agent to be effective at lower temperatures, and can be used for sponge leather calendering. Epoxidized compounds are effective co-stabilizers in most systems; chelators with metal soap improve heat stability. New amine oxide stabilizers designed for use with polypropylene have been developed by GE Specialty Chemicals in its Genox EP range. They are nonhygroscopic, inherently resistant to hydrolysis, and essentially insoluble in water. Derived solely from vegetable sources, the material is claimed to comply with formulations requiring non-animal additives. It shows melt processing and colour stability equivalent to a blend of GE's Ultranox 668 and 13114 at about one-third of loading level, overcoming the disadvantages of phosphite/phenolic formulations, such as colour development on processing and on exposure to nitrogen oxide gas fading. The light fastness of some pigments in polymer systems can be significantly improved by the addition of a UV stabilizer. Cytec has developed a novel material of the di-t-butylhydroxybenzoate class that has a dual role of heat and light stabilization in natural and pigmented polyolefin systems. Flame retardancy to V-2 rating has also been achieved (for moulded stadium seating), using a 3:1 ratio of tetrabromobisphenol A bis(2,3-dibromopropyl ether), with a synergistic amount of antimony trioxide. Nano-technology has been used for a zinc oxide UV absorber by Elementis Pigments: Decelox UV. A particle size of only 5 0 - 6 0 nm gives enhanced UV performance compared with conventional products plus transparency and a biostatic effect. A biostatic additive using the same technology is also being launched under the name Decelox Bio.
8.10 Commercial Trends
With a world consumption of around 280 000 tonnes, consumption of heat stabilizers is considerably larger than of UV stabilizers. PVC is overwhelmingly the largest user but, as thermoplastics are processed faster and at higher temperatures (while also intended for applications at higher temperatures),
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there are many niche opportunities opening up for other materials such as polyolefins and engineering plastics. Great Lakes estimates the global UV stabilizer market at about 28 000 tonnes, worth US$600 million (53% HALSs, 4 1 % BZT, by value). Within the total there will be significant changes in materials, in response to environmental concerns. There is a decUne in the use of lead compounds (the most popular type) and the threatened phase-out of cadmium will have a major impact, but will signal opportunities for other stabilizers. The most significant of the heat stabilizers are lead compounds, which accounted for nearly 68% of volume in 1989, but by 1994 had declined to 64%. Barium/cadmium compounds are the next most important, followed by organotin compounds (which actually come second in value terms). Barium/ zinc and calcium/zinc compounds have a high growth rate due to substitution in some cases of barium/zinc for barium/cadmium because of fears for the effects of cadmium on the environment and health, after it had been found that soluble cadmium products could have an adverse effect on the environment when used at above certain critical levels. Lead stabilizers hold about 60% of the European PVC stabilizer market and organotins 10-15%, while the remainder is liquid or paste combinations of calcium and barium salts with zinc (according to estimates by Akcros). Stabilizers for UPVC window profile are lead-based materials at 68%, barium, cadmium and lead, and barium cadmium at 29%, and calcium- and zinc-based materials at 3%. In the US$2()0 million US market, the main heat stabilizers include lead compounds, organotin compounds, and mixed metal/salt blends based on chemicals such as barium, cadmium, and zinc, and significant changes are expected. Over US$75 million of the business is in lead- and cadmiumcontaining stabilizers, but these are under increasing scrutiny on health and safety grounds. Table 8.7 World consumption of stabilizers (thousand tonnes)
;at stabilizers ^ stabilizers !at and UV stabilizers
World
USA
Western Europe
Japan/Asia
280 16 296
66 7 73
150 5.5 155.5
64 3.5 67.5
Sources: based on estimates by Business Communications Co, Rapra and Townsend
Globalization is increasing the need for broader distribution channels, intensifying competition and pushing prices lower. In response, mergers and acquisitions are common, as large companies search for candidates to broaden their product lines and add distribution channels or technology. The research agency Frost and Sullivan identified at least 170 competitive companies in the US plastics additives market in 1997, with competition at all levels of the supply chain.
CHAPTER 9 Modifying Specific Properties: Resistance to Light - UV Stabilizers
Table 9.1 At a glance: UV stabilizers Function
Blocking harmful UV radiation, or cleaning away any oxidized components
Properties affected
Mechanical properties, resistance to ageing, colouring, outdoor/weathering properties, appearance
Materials
Screening pigments (carbon black, calcium carbonate, titanium dioxide); benzophenones/benzotriazoles, nickel stabilizers, hindered amines (HALSs), polymeric stabilizers
Disadvantages
The chemistry is complex and is still not fully understood
New developments
HALS systems; multi-functional/synergistic effects; replacement of heavy metals
9.1 How They Work
UV stabilizers are used to prevent or terminate the oxidation of plastics by UV light. They therefore act to protect the moulded product during its life, and are particularly used for building products. They act by absorption of energy, deactivating the by-products of oxidation, and decomposition of by-products (or a combination of these). The action is similar to heat stabilizers and antioxidants, and some types also offer these functions. To be strictly accurate, UV affects all types of plastics, but a few (such as acrylonitriles and methyl methacrylates) show better resistance than most. The UV part of sunlight (and in some instances UV light from artificial sources) breaks down the chemical bonds in a polymer in a process called photodegradation, ultimately causing cracking, chalking, colour changes, and loss of physical properties such as impact strength, tensile strength, elongation, and others. Ultraviolet radiation can cause colour change and degradation of physical properties, especially in polyolefins, ABS, PVC, PC, and PU. Stabilizers to protect plastics compounds against the effect of UV light (especially sunlight) act to prevent oxidation from that source. To counteract this, UV additives offer three
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basic mechanisms (which can often be employed together, when two or more are used in the same compound): •
• •
Absorption of, or screening from, UV light. UV absorbers are receptive to UV radiation and dissipate the energy harmlessly as heat. UV screening can, of course, be effected by some pigments, the most effective of which is carbon black - but its application is obviously limited. Titanium dioxide can also be used, but it is expensive and there can be side effects, as noted below. Quenching the energy by means of deactivating metal ions. Quenchers intercept the energy before it can break any molecular bonds, but in a different way. Decomposition of hydroperoxides to non-radicals (^scavengers'). Scavengers inhibit the free radicals generated by UV light, and stop any further decomposition.
Antioxidants are often confused with UV stabilizers, but they are not UV deactivators as such. However, their decomposition by-products can degrade the electromagnetic energy of incoming light and redistribute it as thermal dissipation in the polymer without formation of free radicals, which is a mechanism comparable to that of UV absorbers such as benzotriazoles and benzophenones. UV stabilizers have varying approval worldwide for use in food-contact applications, ranging from broad clearance to no approval: suppliers should be consulted with specific questions. Halogenated or sulphur-based pesticides or fumigants as used in agricultural/horticultural compounds today may chemically deactivate UV stabilizers, and care should be taken in selecting these.
9.2 UV Screening Pigments
A compound can be shielded from the effect of UV by the use of suitable pigments that also have a UV screening effect. Calcium carbonate offers valuable properties in polymer compounds. It is used mainly in PVC, both flexible and rigid. Coarser particles are used mainly but, as compound specifications become more exacting, fine-particle grades coated with stearic acid are used for better mechanical and processing properties. Being white, these grades can also aid in pigmentation and can also assist gloss, including compensating for loss of gloss where lead stabilizers have been replaced by calcium/zinc systems. It is an important component of polypropylene, alone or with talc, for rigidity and whiteness that resists weathering. Metallocene-produced polypropylenes, with greater self-reinforcement, can tolerate higher loadings, for better whiteness. Surface-treated rutile titanium dioxide pigment meets the durability and optical requirements of the European plastics industry, without compromising
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109
dispersion and ease of processing. Technical acceptance has been particularly strong in the uVC market in Europe and manufacturers have accumulated a considerable amount of data on weathering, for various formulations and exposure conditions.
9.3 Absorbers
These additives preferentially absorb the incident UV radiation and so protect the polymer from the radiation. UV absorbers do not themselves degrade rapidly, but they convert UV energy into harmless levels of heat energy, which are dissipated throughout the polymer matrix. UV absorbers are limited in their effectiveness because of the physical limitations of the absorption process, and their ability to absorb is governed by the need for high concentrations of additive and thickness of polymer before sufficient absorption will occur to retard the photodegradation effectively. However, high concentrations of additive would be uneconomic and technically limited, while many applications (such as polyolefins) are in very thin sections, such as film and fibre. Benzophenones are good general-purpose UV absorbers for clear polyolefin systems, and can also be used in pigmented compounds. Benzotriazoles are used mainly in polystyrene. Both can also be used in polyesters. Concentrations are usually about 0.25-1.0%.
9.4 Energy Transfer Agents/Quenchers
These function by returning 'excited' state molecules to their stable 'ground' state. In the absence of a mechanism to achieve this, homolytic bond cleavage can occur, resulting in the formation of free radicals. Nickel stabilizers are believed to function as energy transfer agents.
9.5 Scavengers: Hindered Amine Light Stabilizers
Much attention has centred on hindered amine light stabilizers (HALSs), which are efficient scavengers and function by inhibiting degradation of polymers that have already formed free radicals (see also Chapter 7). Commercially, they are now the single most important light stabilizers, followed by benzophenones and benzotriazoles. Tetramethyl piperidines were first identified as potent traps for free radicals in the 1960s and the first generation of HAS was commercialized in the 1970s as effective light stabilizers for polyethylene, polyamides, and acrylics. But the mechanism by which HAS act to stabilize polymer radicals is still not entirely clear.
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HALSs are suitable for use with most commodity resins. An important advantage is that they bind additives to the polymer at the molecular level, causing less antagonism towards other additives. However, the degree of protection may be reduced by migration of the stabilizer and by interaction with environmental agents such as acid rain and agricultural chemicals. They can also interact with other additives, particularly anti-oxidants, under high processing temperatures or prolonged exposure of the product to elevated temperature. The mechanism is not fully understood. Hydroperoxide decomposition and free radical scavenging certainly play a part, as also does the regeneration of HALSs, where UV absorbers are frequently consumed as a result of their operation. There are several theories for how this works - possibly by energy transfer, free radical termination, or peroxide decomposition. Significant stabilization is achieved at relatively low concentrations and it appears that the HALS is actually regenerated by the stabilization process, rather than consumed by it. Theory suggests that the hindered amine oxidizes to form amine-ether, which is a non-radical species. The effectiveness of HALS systems does not depend on the thickness of the plastics product and they are therefore particularly useful for protection of surface layers and in thin sections. Agents are of low or high molecular weight. Polymeric HALSs offer superior compatibility, low volatility, excellent resistance to extraction, and contribute to heat stability. Combination of two high molecular weight grades gives a good balance of properties in greenhouse film, which is the main use of HALSs in LDPE film. Claimed to be the first tertiary HALS of its type to be sanctioned by the US Food and Drug Administration as an indirect food additive, a new high-performance additive has been introduced by Cytec Industries, under the name Cyasorb UV 3 529. The company adds that it has applied for the European equivalent to FDA approval. It has low reactivity towards co-additives and environmental agents, making it a good choice for pesticide resistance and lower pigment interaction. Lower pigment interaction leads to dramatic improvements in colour yield and UV stabilization in coloured plastics applications. High molecular weight provides the polymer permanence required for products today.
9.6 Synergists with HALS
A number of beneficial effects can be obtained by using other light stabilizers in conjunction with a HALS system. Specific cyanoacrylate-based UV absorbers offer particular benefits, for example in ABS and PA, and as individual components in rigid or plasticized PVC, polyurethane foams, and SB rubber. Broadband absorbers based on benzophenone can be used, for example, in sunshading sheet. Ferro's UV-Chek AM 340 is a hydroxybenzoate ester light stabilizer that is used in conjunction with a HALS. It functions initially as a radical-free
Modifying Specific Properties: Resistance to Light - UV Stabilizers
111
terminator and later, in the presence of light, slowly rearranges itself into a hydroxybenzophenone, when it acts as an absorber. New patented polyfunctional additives from Ciba are claimed to act as both primary and secondary anti-oxidants. Based on hydroxylamines, functioning as free radical scavengers, peroxide decomposers, and reducing agents, they have low colour and act synergistically with HALS UV stabilizers. Coded FS, they are designed to replace blends of phenolic, a phosphite, or thioester and a HALS, and are aimed initially at PP fibres, but early trials show similar benefits in PP films and thick-section parts. BASF has developed HALSs and UV absorbers in the Univul range: three HALS grades are especially suitable for ABS, PA, PP, HDPE, and PMMA and include a grade with outstanding light fastness at high temperature (for automobile applications, for example). Schulmann has introduced a new HALS UV stabilizer with good resistance to pesticides. For greenhouse and agricultural films, a HALS offering excellent clarity and outstanding UV resistance and an alternative nickel quencher have been introduced by Colortech for apphcations where conventional stabilizers may be exposed to chemical deactivation (as when exposed to halogenated or sulphur-based pesticides or fumigants).
9.7 Polymeric Stabilizers
An acrylate terpolymer (Sunigum P7395 from Goodyear) is intrinsically resistant to both heat and UV light. Designed for both halogenated and halogenfree polar resins, it can be used as an elastomeric modifier or as the main polymer in soft thermoplastic elastomers. Potential applications include 'soft-touch' interior automotive parts (skins, mouldings, and profiles), glazing gaskets, wire and cable, sheet, and consumer products. It costs about US$4.60 kg~^ (DM7 kg~ ^), offering higher value to non-halogenated materials.
9.8 Blends
Ciba's Tinuvin 791 and 783 are blends that exploit the advantages of combining low and high molecular weights to give superior light stabilization in thick PP sections and talc-filled grades. Low molecular weight Tinuvin gives low mobility and superior stabilization; high molecular weight Tinuvin and Chimassorb give good compatibility, extraction resistance, and long-term thermal stability.
9.9 Replacement of Heavy Metals
Innovative sulphur-free tin stabilizers for PVC have been introduced by Elf Atochem under the Thermolite 410 (for white and coloured rigid applications,
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such as window profiles) and Thermolite 450 (specifically developed for translucent applications, such as roofing) names. The additives, available in solid tablet form and easy to handle, ensure that rigidity is maintained in the PVC compound. Being free of sulphur, there is no unpleasant odour during handling and extrusion. They have good self-lubricating properties and give end products a high level of weather resistance, offering a technical and cost-effective alternative to stabilizers based on heavy metals. A new direction in development is signalled by ColorMatrix Europe with an additive giving UV protection to PET bottles. It is claimed to block all radiation up to 380 nm and achieve the same level of UV screening as other products at half the dosage level.
Table 9.2 UV stabilizers: selection guide
ABS Fibres Polyamide Polyesters Polyethylene Polypropylene Polystyrene Polyurethane PVC Elastomers
X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Key: A, benzophenone UV absorbers; B, benzotriazole IIV absorbers; C, HALSs; D. special stabilizer blends. Source: Great Lakes Chemical
9.10 Selection of Antioxidants for Use with UV Stabilizers Care is needed in selecting anti-oxidants for use in combination with effective light-stabilization systems. High molecular weight stabilizers provide high levels of heat stability at normal application temperature. To avoid colour shifts (especially yellow discolouration), BHT-free resins should be used with HALS formulations. Sulphur-containing organic compounds used as thio-synergists are known to reduce the light stability level conferred by HALS, and high levels should be avoided.
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113
9.11 Concentrates, Masterbatches Table 9.3 Typical UV stabilizing systems in masterbatch form** PE food contact
PE greenhouse film
PP coloured food contact
General purpose
PP tapes, mouldings
PP coloured food contact
Base resin
PE
PE
PP
PE
PP
PP
HMW-HALS
Yes
Yes
Yes
Yes
Low molecular weight
Yes
Benzophenone Yes
Yes
Yes
Food eontact
Yes^'
Yes"
Yes
Yes
Thermal stabilization
Good
Good
Very good
Very good
Good
Application^ and let-down
Heavy-duty sacks: 1.5-2.5%; film: 1.25-1.75%, 2.5-3.5% (24m); mouldings: 1.5-3%
Heavy-duty sacks: 1.5-2.5%; greenhouse film: 1.25-1.75%, 2.5-3.5(24m)
Tapes: 1-3%; fibre: 1-3%; mouldings: 0.5-2.5%
Shrink wrap: 0.75-1.5%; greenhouse film: 1-1.5%; HDPE crates: 0.2 5-0.5%; mouldings: 0.5-2.0%
Tapes: Food crates: 0.5-2.0%; 0.5-1.5%; mouldings: tapes: 0.5-2.5% 1-3%: black tapes: 1-3%
Yes Limited
" Except fatty foods in Ck>rmany. '' Application examples are for UK usage, except HDPE crates, pigmented (European usage). Sowrc: Colloids
9.12 New Chemistry
Patented photoreactive chemistry is used in a new^ type of HALS by Clariant Huningue, under the name Sanduvor PR-31. The technology, w^hich is triggered by exposure of the product to UV light for 5 to 20 days, grafts the HALS molecules to the matrix polymer, forming an outer layer that absorbs UV and improves the long-term weathering resistance. Volatility, extraction, and migration are all reduced. The stabilizer is especially suitable for pigmented and unpigmented polyolefins and also for selected engineering resins. Elf Atochem has carried out work in the USA on incorporation of reactive groups linking the agent into the molecular structure, to give long-term stabilization. Results to date include a HALS system, Luchem HA-RIOO, using a hydrazide end-group (N-2,2,6,6-tetramethyl-4-piperidynyl-N-aminooxamide) to provide a site for chemical binding. In the form of an odourless white powder, it is designed for long-term stabilization of polyolefins and engineering polymers.
9.13 Recent Developments
A range of high-performance UV stabilizer masterbatches for polyesters has been introduced by Chemiehandel SE, Switzerland, under the Sukano name. They are
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in carriers suitable for crystallizable PET and amorphous polyesters, to improve UV resistance for indoor and packaging applications, and enhance weather resistance. Montell's Xantrix ADS 13015 UV stabilizer is a concentrate to meet automotive standards for weather resistance of moulded parts: it is added at 1 2.5 wt% level. A specially formulated black masterbatch, incorporating a high-weathering grade of carbon black with a full stabilization package, has been introduced by Cabot Plastics (Plasblak PE4441) to meet the need for a high-performance stretch and protective film requiring a high level of resistance to weathering and minimal development of perforations and pinholes. The quality of the carbon black used ensures very uniform dispersion within the host polymer which, combined with the stabilization package, results in a high level of UV protection and good resistance to thermal degradation during processing and working life. Cyasorb 1084 is a nickel phenolate light stabilizer by Cytec Industries, reported to be in strong demand worldwide for applications ranging from agricultural film to artificial turf. Three nickel-free UV stabilizer masterbatches for horticultural film applications have been introduced by Cabot Plastics. Also new are a universal black masterbatch giving high gloss colouration and a specialized grade for silage film. The new additive masterbatches are products that are free of nickel quenchers, improving the stability of polyethylene films and developed specifically for horticultural films likely to be contaminated by pesticides. They will provide protection for up to four years, even in high-radiation areas such as the Mediterranean. Among recent developments in HALS from Great Lakes Chemical is a tertiary amine HALS, Uvasil 816, offering better performance (including better resistance to pesticides) in applications such as polyethylene greenhouse film. New BZTs include Lowilite 55, for processing at high temperatures, and Lowilite 94 for PP, with food-contact approval. Nylostab S-EED is an aromatic HALS used as a multi-functional additive in polyamides. Due to a novel chemical structure, it combines the effect of a light and heat stabilizer, resulting in fiow improvement particularly in fibres, and its action in the improvement of colour strength with pigments and dyes. Hycite EXM and Sorbacid EXM (Sud-Chemie) are extremely fine magnesium/ aluminium hydrotalcites, for use as co-stabilizers for polyolefins and PVC, respectively. They effectively neutralize acids from catalyst residues or decomposition products of primary and secondary stabilizers. Corrosiveness of polymers is decisively reduced by absorptive immobilization of anions, especially chloride. Sorbacid is mainly used in environmentally friendly and non-toxic formulations free of heavy metals, together with Ca/Zn systems. It has excellent dispersion in small particles, which, with a special surface modification and a refractive index close to that of PVC, gives formulations for transparent applications without any restrictions.
CHAPTER 10 Modifying Specific Properties: Flammability - Flame Retardants Table 10.1 At a glance: flame retardants Function
Acting to retard ignition, control/douse burning, reduce smoke evolution: flame retardants function either by generating extinguishers at fire heat (water, steam, gases) and/or by forming a non-flammable char layer on the surface, to insulate and exclude oxygen. Some plastics (PVC, polyphenylenes) have a degree of inherent flame retardancy, but may require boosting.
Properties affected
Ignitability, flame support/propagation, emission of smoke and fumes, smouldering/afterglow.
Materials/characteristics
Some inorganic flllers. Nitrogen-donors: melamine compounds. Antimony compounds with halogen donors. Halogenated: containing chlorine, bromine. Halogen-free systems: aluminium trihydroxide (ATH), magnesium hydroxide, zinc borate. Intumescent systems: phosphorus compounds.
Disadvantages
Evolution of noxious (possibly toxic) smoke/fumes from certain types: some flame retardants are possible carcinogens; difficulty of obtaining relevant performance data which is reproducible; depending on concentration: effect on colouring/appearance; processability; food-contact properties.
New developments
Replacement of halogenated types; reduction in emissions; synergistic effect of combinations; multi-functional systems combining two or more fire control functions.
10.1 How They Work
Nearly all plastics are based on hydrocarbons and are combustible. For use where safety is essential - such as aircraft, building/construction, public transport, and increasingly in housings for electrical/electronics equipment they must be rendered incombustible, or at least difficult to ignite and burn. Certain thermoplastics, such as PVC and modified PPO, are to some extent inherently resistant to burning, but may need to be supplemented by additives. Flame retardant (FR) additives work by breaking one of the links that produce and support combustion: heat, fuel, and air. They may quench a flame by
1 16
Additives for Plastics Handbook
depriving it of oxygen or may absorb heat and produce water, so reducing the temperature. Increasingly, FR additives are used in combination, often with a synergistic effect. But experience has shown that fire itself is not the real hazard: far more dangerous to people are the toxic by-products generated during combustion, and dense smoke that prevents people from escaping in time. The control of these is becoming the decisive factor in assessing FR additives. The way in which materials burn is extremely complex and still not fully understood. Equally complex methods are needed to prevent or retard burning, and the answers are becoming ever more sophisticated. Although a few plastics, such as PVC and PPO compounds, possess a degree of inherent flame retardancy and may not readily burn, FR additives by definition act after combustion has started, and operate by interfering with the combustion process. The usual mechanism is to cool the flame (often simply by releasing water), or to starve it of oxygen by releasing nitrogen or halogens, or by forming a carbonaceous char layer over the burning plastic. Some FRs perform more than one of these actions, or can be combined to produce a sequence of useful reactions in a fire. Bitter experience has shown that, as well as controlling and smothering the flame, it is vital that the FR system does not produce toxic, dense, or noxious smoke and fumes. Moreover, it should assist in preventing burning material from dripping and so spreading the fire, and should reduce the afterglow. The key tests for FRs are: • • •
peak rate of heat release, indicating how far and rapidly a fire will spread; limiting oxygen index (LOI), determining relative flammability of polymeric materials: the higher the LOI value the more flame retardant the test specimen; smoke suppression, indicating relative hazard from inhalation of smoke and toxic fumes.
10.2 Summary of FR additives
The main FR additives are summarized in the following table. Table 10.2 Summary of the main FR additives Type
Mechanism/comments
Aluminium trihydrate (ATH)
In volume, the most widely used FR additive: also an economical filler/ extender. Acts by endothermic dehydration, simultaneously absorbing heat energy: maximum processing temperature is about 200°C. Necessary high loading can impair mechanical and electrical properties.
Antimony trioxide
Synergistic effect with most halogenated FRs. It is also used in plasticized PVC because of its synergy with chlorine. Antimony oxide should not be used if translucency is required.
Modifying Specific Properties: Flammability - Flame Retardants
117
Type
Mechanism/comments
Magnesium hydroxide
Temperature stable to 3 32°C, allowing processing with a wide variety of thermoplastics and use where aluminium trihydrate is not sufficiently stable. Lower smoke ratings than with halogenated additives can usually be obtained. It is used particularly in cable sheathing, polypropylene, and polyamides. Prospects generally good.
Phosphorus compounds
Reduced smoke obscuration and corrosivity: development of halogen/phosphorus synergism could lead to wider use as a substitute for antimony oxide. Halogen-free phosphorus compounds are expected to boost sales in volume and value.
Chlorinated FRs
Effective FR action by quenching flame, but not favoured on environmental grounds and steadily being phased out.
BrominatedFRs
General: heavier than chlorine, more efficient; decomposition products less volatile at high temperatures.
Polybrominated diphenyl oxide (PBDO) Decabromodiphenyl
Widely used in plastics such as ABS; uncertain future because possible pollution during incineration. Especially useful in polyamides and PBTs polyesters; good resistance to high processing temperatures and weathering, good colour stability; used at low concentrations.
Dibromoneopentyl glycol(DBNPG)
Mainly for polyester resins: high chemical and flame resistance, minimal thermal discoloration, excellent light stability; can also be used with polyurethane rigid foams.
Pentabromobenzyl acrylate
Polymerized in extruder; gives V-O ratings without loss of properties in nylon 6 and 66, PBT and polycarbonate.
Tribromoneopentyl alcohol (TBNPA)
Reactive FR; exceptionally stable, particularly thermal, hydrolytic and light; highly soluble in polyether polyols; particularly suitable for polyurethane polymers.
Melamine cyanurate
Stable up to 32()°C; compounds exhibit high E-modulus, elongation at break, and Charpy impact strength.
Zinc borate
Stable up to 29()°C, promoting char (enhanced by liner particles); also suitable for use in translucent halogenated polyester resin, improve fire performance retaining clarity.
Source: Plastics Additives and Compounding
FR additives may be inorganics, such as aluminium trihydrate (ATH), antimony oxide, or zinc borate, or organics such as phosphate esters or halogenated compounds of various types. Most FR additives contain bromine, chlorine, phosphorus, antimony, or aluminium. Among the main types are brominated hydrocarbons: additive and reactive; phosphate esters: non-halogenated and halogenated; antimony oxide: trioxide and pentoxide, and sodium derivatives; chlorinated hydrocarbons: chlorinated paraffins, chlorinated cycloaliphatics. Other types include chlorinated/ brominated compounds, fluorinated compounds, magnesium carbonate, magnesium hydroxide, melamine, molybdenum compounds, silicone polymer,
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and zinc borate. Such is the importance of FR capability, within very tight environmental legislation, that the list is being added to almost daily. There are two basic types of flame-retardant chemicals: reactive FRs and additive FRs. Reactive FRs are usually introduced during the polymerization stage and copolymerized, together with other monomers. They therefore have only minimal effect on mechanical properties. Typical examples are tetrabromobisphenol A, dibromoneopentyl glycol, vinyl chloride, and bromo- or dibromostyrene. Additive FRs are introduced during a subsequent compounding stage. These include chlorinated paraffins, brominated organics, phosphate esters, aluminium trihydrate, magnesium hydroxide, borates, and antimony trioxide. A third approach employs an additive which, under high heat, will intumesce, forming a barrier which is not only non-combustible but also acts as a thermal insulator, so protecting the substrate. The lowest-cost additive is aluminium trihydrate, which finds its largest application in polymers processed at low temperatures, such as epoxy resins, unsaturated polyesters, polyethylene, and PVC. High loadings are required, which can affect the physical properties of the polymer. Chlorinated paraffins offer low cost and application in all polymers that are processed at less than 240°C. Bromine, on a weight for weight basis, is a more effective FR but, on cost/ performance, chlorinated paraffins can be more effective than aromatic bromines. 70.2.7 Reactive FRs
These are mainly relevant to thermosetting resins, such as unsaturated polyesters and epoxies. For polyesters, the main reactive retardants are HET acid (based on chlorine) or dibromoneopentyl glycol (DBNPG). Brominated FRs are said to be 70% more efficient than HET acid (which has also become expensive). With epoxies, the best system (on present evidence) appears to be reactive phosphorus organic compounds, which are toxicologically harmless in fire and are chemically linked to the resin matrix, so that mechanical and chemical properties are not affected. 70.2.2 Additive FRs
Additive FRs are more frequently used and are very numerous, depending on the precise conditions in which the additive is expected to operate (and also the desired cost level). 10.2.2.1 Inorganics Aluminium trihydrate (ATH) is also known as hydrated alumina. It is the most widely used FR additive in volume terms, representing 43% of all flame-retardant chemicals in volume (but only about 29% in value). As well as flame retarding and smoke suppressing, it is an economical filler/extender. In a fire, it undergoes an endothermic dehydration with a twofold action, simultaneously absorbing
Modifying Specific Properties: Flammability - Flame Retardants
119
the heat energy needed to sustain combustion and releasing water vapour that dilutes the combustion gases and toxic fumes. It is used mainly in unsaturated polyesters in the building/construction industry, and in cable sheathing compounds. Use is limited by a maximum processing temperature of about 200°C, and the high loading needed to achieve good flame-retardant performance can be detrimental to mechanical and electrical properties. It is not stable at high temperature, due to loss of water. To improve the performance, surface-modified grades have been developed with enhanced processability and chemical coupling. Improved compatibility with the matrix polymer aids rapid and complete dispersion while a significant reduction in viscosity can give improved processability or increased loading levels, while maintaining acceptable processability. Selected surface modifications (particularly based on organofunctional silanes) can also improve specific properties, by increasing the ATH/ polymer interfacial adhesion. Typical improvements are flame/smoke properties, mechanical properties (including increased tensile, flexural, impact, and elongation), and better resistance to water permeation, which may improve electrical properties. Metal hydroxides such as aluminium trihydroxide and magnesium hydroxide (MDH) have a significant twofold action, as FRs and smoke suppressants. The mechanism includes cooling due to endothermic reaction, a dilution effect on the polymer (by supplying less fuel), formation of a char barrier, and reduced oxygen concentration due to the presence of a vapour. In common with inorganic fillers, however, metal hydroxides often exhibit hydrophilic properties, attracting moisture at their surface and producing poor compatibility with a hydrophobic plastic or elastomer. New metal hydroxides (from Alusuisse Martinswerk) are surface treated with polar OH groups (often fatty acids), producing a strong filler/ filler interaction leading, especially at high loadings, to increased viscosity. Aluminium trihydroxide begins to decompose at temperatures above 18()°C, with an endothermic reaction that absorbs 1-2 kj g~^ of energy. This has the effect of decreasing the rate of heat release from a burning polymer filled with aluminium trihydroxide, also decreasing the time to ignition and surface spread of flame. It is also an excellent smoke suppressant, due partly to the fact that a high loading naturally reduces the amount of available combustible material, but also because the high-surface-area aluminium oxide formed during combustion will also adsorb fine smoke particles, and will act to catalyse crosslinking reactions, promoting formation of a solid char rather than smoke. Controlled viscosity and ultralow viscosity grades (allowing exceptionally high loadings) are among developments (by Alcan), while modification of particle shape with a reduction in coarse particles offers many advantages during compounding. Surface-modified grades by Huber Engineered Minerals (Hymod) give better dispersion with increased compatibility with the resin matrix, resulting in lower viscosity or increased loading, for improved processing and properties. Magnesium hydroxide can impart flame retardancy and smoke suppression to a wide variety of thermoplastics and elastomeric formulations. It is temperature
120
Additives for Plastics Handbook
stable to 332°C, allowing processing with a wide variety of thermoplastics and use where aluminium trihydrate is not sufficiently stable. Lower smoke ratings than with halogenated additives can usually be obtained. It is used particularly in cable sheathing, polypropylene, and polyamides. Magnesium hydroxide offers a cost-effective replacement for ATH in flame retardancy and smoke suppression. It produces more char and dilutes the fuel available to sustain combustion. It allows processing at up to 100°C higher than ATH, and can significantly improve efficiency. It is also less abrasive than ATH, giving longer life to processing equipment. During combustion the chemical generates a highly reflective coating of magnesium oxide, deflecting the heat of the flame. It contains about 30% bound water, which starts to be released at 330°C, blanketing the flame and limiting the oxygen available. It also absorbs 17% more heat than ATH, so reducing the likelihood of continued burning. Grades (such as MagShield from Martin Marietta) exhibit low toxicity (LDSQ (oral/rat) > 5 0 0 0 mg kg~^) and are non-corrosive compared with flameretardant systems containing halogen or phosphorus. Antimony trioxide has a synergistic effect with most halogenated FRs. It is also used in plasticized PVC because of its synergy with chlorine. Antimony oxide should not be used if translucency is required. In some cases ferric oxide is used in its place, for similar physical properties but improved electrical properties. It has been shown by extensive research to be non-carcinogenic. For polymers apart from PVC, a 50% replacement of antimony trioxide is possible with virtually all polymer systems. In particular with both plain and glass-reinforced nylons, excellent flame retardation can be achieved with a suitable combination of zinc sulphide and melamine cyanurate, eliminating both halogens and antimony trioxide.
10.3 Halogenated Compounds
These are mainly chlorinated or brominated compounds. Economically they have been the most important but, under strong pressure from environmental lobbies, use of chlorine as a flame-retardant component has been sharply reduced and the attack has now turned to bromine flame-retardant compounds. These are more numerous than chlorinated, because their efficiency is significantly better due to the fact that bromine is heavier than chlorine and decomposition products are less volatile at high temperatures. The plastics industry claims that there is no scientific evidence to support the belief that dangerous compounds can be released on incineration and the safety of bromine-based retardants has been confirmed by bodies such as the US Environmental Protection Agency, the United Nations, the World Health Organization, and the Organization for Economic Cooperation and Development. Nevertheless, some compounds have been withdrawn. Halogenated phosphate esters are also suitable for PS and PU foams and thermosetting resins.
Modifying Specific Properties: Flammability - Flame Retardants 70.3.7 Chlorinated
121
compounds
These were originally seen as important FRs, particularly in reinforced thermosetting plastics, but the emission of chlorine compounds has also been shown to be a hazard to health and, with water (as, for example, from firefighting apparatus), a cause of HCl with corrosion damage to metal parts. Chlorinated FRs have been used for many years in combination with antimony oxide in polyethylenes. The optimum FRrantimony oxide ratio is 1:1, but the oxide can be minimized by increasing the ratio to 2:1 and even 3:1. For a UL 94 V-0 rating, the amount of additive required depends on the melt index of the polymer; high levels being required for higher loadings. Chlorinated paraffins are claimed to be one of the lowest cost FRs besides the hydrated metal oxides. They can be used with antimony oxide as FRs in unsaturated polyester resin systems. Special grades have been developed by Dover Chemical in its Hordaresin and Chlorez ranges for flame retarding highimpact polystyrene, offering an absence of polyhalogenated biphenyls or dioxins, low cost, improved melt flow, and better UV stability than aromatic brominated FRs. They are also used in rubber compounds, where they can also improve tensile and tear properties of neoprene, SBR, and nitrile, and in EPDM rubber for electrical or roofing products. Dover Chemical quotes data from Ford Motor Co. that its Hordaresin NP 70 and Chlorez 700 grades can also function as coupling agents in mica-filled polypropylene. The compounds show sufficiently low cost and high modulus to make them economic replacements for certain applications where steel is normally used. Use of lower-cost mica in place of glass fibre can also offer potentially large cost savings. Table 10.3 Effect of chlorinated FR additives on PE and PP compounds Polyethylene
FR additive Antimony oxide Stabilizer UL 94, 3.0 mm Total burning time (s) Drip characteristics Cotton ignition Oxygen index Araphoe smoke (%) Shore hardness A/D Izod impact (J m~^) Tensile (MPa) Elongation (%)
Polypropyl ene
A
B
C
A
B
C
100
66
72
100
62
60
24 10
20 8
27 10 1
29 10 1
v-o
v-0
Burns 10 Drip
10 Non-drip
-
18.5 2 96/45 32 7NB 10.1 150
24.0 11 98/54 105HB 10.1 50
24.5 12 98/52 172HB 10.7 75
v-o
V-0
Non-drip
Burns
-
Drip Yes 18.0 3 95/64 5.33PB 22.1 187
23 Non-drip No 2 7.0 13 96/71 43.7CB 27.6 38
10 Non-drip No 27.0 10 97/70 53.3CB
-
Key: 5 samples - 10 ignitions (10 s each). NB = no break; HB = hinge break; PB : partial break; CB • complete break. Source: Dover Chemical Corp
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Additives for Plastics Handbook
10.3.2 Brominated
compounds
New brominated FRs are being introduced almost daily, making it impossible to give a comprehensive list. Great Lakes, the leading manufacturer, lists 26 grades, in six main chemical types. Other manufacturers are working on other types. The main groups are summarized here. Polyhrominated diphenyl oxide (PBDO) compounds are suitable for most plastics, except PS foam. They have an uncertain future because of fears about possible air pollution during the incineration of plastics waste. Dibromoneopentyl glycol (DBNPG) is a reactive FR containing 60% aliphatic bromine. Thermosetting polyester resins can be formulated with this over a wide range of compositions to provide a broader selection of resin properties than are available with anhydride FRs. Resins formulated with types of DBNPG have high chemical and flame resistance, minimal thermal discoloration, and excellent light stability. It can also be used with polyurethane rigid foams. Dibromostyrene and derivatives include graft copolymers with polypropylene. They are recommended with ABS and stryenes, most engineering thermoplastics, unsaturated polyester resins, and polyurethane foams. They are not recommended for PVC, PS foam, and rigid PU foam. Hexabromocyclododecane is used with high-impact polystyrene, polyolefins, and PS foam. Pentabromobenzyl acrylate (developed for engineering thermoplastics and now in full production by Dead Sea Bromine Group) can be polymerized or copolymerized in the extruder, giving UL 94 V-O ratings without loss of physical or mechanical properties in host resins such as nylon 6 and 66, PBT, and polycarbonate. Tetrabromobisphenol A grades are available for use with most resins, except polyamides, PVC, and rigid and flexible PU foams. Tetrabromophthalic anhydride and derivatives are used mainly with thermosetting resins and PUs; also with PVC and thermoplastic elastomers. Trihromoneopentyl alcohol (TBNPA) is a reactive FR containing more than 70% aliphatic bromine. It is exceptionally stable and is particularly suitable where thermal, hydrolytic, and light stability are required. It is highly soluble in polyether polyols, making it particularly suitable for use in polyurethane polymers. Tribromophenol and derivatives (also known as brominated epoxy oligomers) are used with ABS and styrenes, polycarbonate, polyamide, PS, and PU foams, and thermosetting resins; not suitable with polyolefins and PVC. Renewed development and marketing effort is expected with brominated epoxy oligomers, now in the hands of Resolution Performance Products, following a sell-off from Shell. These materials are well established for thermosets, such as epoxy resins, phenolics, and vinyl esters, but modified grades have recently been introduced aiming at thermoplastics, such as styrenic and (significantly, because of its potential in electrical and electronics equipment) ABS. Thermoplastic polyesters, elastomers, and polyolefins can also be flame retarded with these materials which have a bromine content of 50-60% weight
Modifying Specific Properties: Flammability - Flame Retardants
123
for weight, and are thermally stable at above 300°C. A low softening temperature of 110°C makes for easy compounding. In ABS, BEOs offer good UV stability and relatively high flow, while maintaining high Vicat and heat distortion values, pointing to applications in business equipment, where there are thin parts requiring high flow, good colour stability, and good thermal properties. Flame retarding of ABS produces a loss of impact strength, but this is less with a high-bromine-content additive. For thermal properties, the user has a range of FR grades giving much the same performance, and considerably lower and higher values. Similarly, a range of results gives an effective span of LOI values, and for the standard UL 94 flammability test. Table 10.4 Effect of varying ratios of chlorine and bromine on ABS compounds l:lCl:Brph as varying ratios of antimony trioxide
Varying ratios of chlorine and bromine Formulation: ABS CI FR-2 Antimony trioxide (Sb203) BrFR-1 Properties LOI UL 9 4 - 3 . 2 m m UL 9 4 - 1 . 6 m m Notched Izod (J m M Heat distortion temperature (°C) Halogen ratios C\ (%) Br (%) Total halogen (%)
A 78.1 16.9 5
-
-
B 75.55 8.45 5 11
25.75 V-O NC 64
31.25 V-O V-O 97
27.25 V-O NC 97
-
-
-
11
5.5 5.5 11
-
-
11
C 73 5 22
11 11
A 81.7 8.45 2 7.85"
B 77.65 8.45 6.1 7.85"
C 73.7 8.45 10 7.8 5"
24.25 NC
30.75 V-O
29.25 V-O
-
-
-
5.5 5.5 11
5.5 5.5 11
5.5 5.5 11
174 95
136 94
105 95
' Br FR-2.
10.4 Other Flame Retardants 70.4.7 Melamine cyanurate
(MC)
Development of MC in Europe has been stronger than in other regions, largely due to local availability of raw material, and by the mid-1980s the main application was in polyurethane foam. Significant also is the expiry of a Japanese patent for MC in polyamides, but the most important development has been the evolution of suitable compounding technology. As one of the major producers of melamine, DSM has made this material a special Business Group, marketing under the name Melapur. Whereas most FRs act by interfering with one of the three main supports for combustion, heat, fuel, and oxygen, MC acts against all three. In the initial stage
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Additives for Plastics Handbook
it creates a heat sink by endothermic actions and subsequent decomposition of melamine vapours. It provides only about 40% of the heat of combustion of hydrocarbons, and the combustion then generates nitrogen, which acts as an inert diluent. It can also retard the loss of other flame-retardant components (such as bromine and phosphorus), capturing these volatile components by formation of salts while still showing flame-retardant activity at a later stage. Finally, it can also make a considerable contribution to formation of char in the intumescent stage and a strong nitrogen/phosphorus synergistic effect is ascribed to formation of nitrogen/phosphorus substances that remain in the char, providing protection against further oxidation. It can also act as a blowing agent in the char, enhancing the barrier functionality of the char layer. Melamines must be employed at a large loading (up to 65% by weight) to meet adequate fire retardance effectiveness, with possible reduction of physicomechanical performances of end products. Melamine is also used as an organic filler to fire retard polymeric materials, which particularly improves UL 94 behaviour of polypropylene (PP) when used at the same overall loading. However, introduction of melamine or inorganic fillers causes processing and compounding difficulties. For all fillers examined, mixtures containing 40% of melamine and 25% of mineral filler (60/40 w/w) show the best compromise between LOI and UL 94. DSM's Melapur 200 is a melamine polyphosphate, and is expected to have a major impact on fire retarding electrical and electronics products. It follows the same mechanisms as MC grades but offers higher thermal stability. The advantages have been shown so far with nylon 66 - and it represents a breakthrough in that, where MC is difficult to use with glass-fibre reinforcement, Melapur 200 is specifically targeted at glass-reinforced nylons. Corrosion behaviour is significantly better than halogenated FRs - up to 7 times in 100 hours - and there are improvements in gas emissions and smoke opacity. 70.4.2 Zinc borate
This, in ultrafine grades with surface areas from 10 to 15 m^ g~^ and thermally stable up to 290°C, functions mainly in the condensed phase, promoting the formation of a char, which can be enhanced by the finer particle size. Grades are also suitable for use in translucent halogenated polyester resin systems, to improve fire performance while retaining clarity, and/or with a refractive index of 1.5 9 (similar to that of glass and many polyester resins). In a fire, zinc borate on its own forms a vitreous mass on the polymer surface providing a barrier between the flame and the source of support. In antimony- or halogen-based systems it helps formation of Sb-O-Cl groups, extinguishing the flame and suppressing fumes while promoting formation of polyaromatic structures. The Borax material has until now been used mainly for total (or more recently, partial (40-75%)) replacement of the more expensive antimony oxide in PVC, polyolefins, nylons, and elastomers. Borax has grades in its Firebrake range which retain their thermal stability up to 415 and 500°C and are therefore well suited to uses in technical plastics.
Modifying Specific Properties: Flammability - Flame Retardants
125
Firebrake ZB 415 with Dechlorane Plus gives flame-retardant properties superior to those of antimony oxide alone. Grade ZB 500 makes it possible to suppress fumes from fluoropolymers, and gives good flame-retardant properties to poly(ether ketone)s and poly(ether sulphone)s. Other key applications are talc-reinforced PP replacing PVC, ABS, and PA 66 in electrical/electronic applications, and EVC cable compounds. 10.43 Zinc hydroxystartnate
(ZHS) and zinc stannate (ZS)
These, developed by the tin industry research organization, ITRI, UK, provide good synergists for replacement of antimony trioxide. They are non-toxic, cost effective, and offer technically superior alternatives, including outstanding smoke suppression, non-toxicity, lower heat release rates, dual-phase action, and synergy with inorganic fillers. They can effectively be used with rigid and flexible PVC, polyester resins, chlorinated rubbers, and polyamides. 70.4.4 Zinc
sulphide
Zinc sulphide can be used to replace antimony trioxide in many systems, including rigid PVC but, until now, its properties have been optimized for white pigmentation rather than for flame retardancy. Flame-retardant grades have now been produced for use both alone and in synergistic compounds. The flameretardant mechanism is not yet fully understood, but it appears to lie in the formation of a non-combustible layer of carbon char, reducing the supply of combustible gases feeding the flame and significantly reducing the generation of undesirable combustion gases and particles. Improvements are also reported in thermal stability, ageing resistance, pigmentation properties, processing properties, and dry-lubrication. Advocates see zinc sulphide as an ideal FR for a wide range of polymer systems. LOI testing shows a significant increase in value compared with pure PVC and PVC with antimony oxide, but the best indices are given by a combination of zinc sulphide and antimony oxide. 70.4.5 Metal hydrates
These may present some problems in incorporation into compounds while maintaining the desired physical properties, but a zero-halogen magnesium hydroxide flame-retardant concentrate on a polyolefin base (by Uvtec under the name Safe FR 5000) can easily be dispersed into polyolefin products. It is predispersed to run on existing PVC production equipment and is non-corrosive and non-abrasive to processing equipment. It is halogen free, with low smoke and no acid combustion gas. There is no leaching of the flame-retardant component and it is recyclable and environmentally safe, available in UVstabilized formulations. Based on zinc and molybdenum, Sherwin Williams' Kemgard is a complete line of smoke suppressants for PVC and other polymers. At 3-10 phr dosing, they
126
Additives for Plastics Handbook
offer up to 80% smoke reduction and promote formation of char, giving a lowcost replacement for antimony oxide. Table 10.5 Effect of individual fillers (UL 9 4 test of PP) Filler
Melamine
Talc
Kaolin
A1(0H)3
Mg(0H)2
MgCOi
B
-
B B B B
B B
v-o v-o
B B B B V-1 V-1
B B B B B V-1
V-o
v-o
v-o
(%) 0 15 30 45 60 65 75
B B B V-0 V-0 V-0
v-o
B
10.5 Phosphorus
Phosphorus-based retardants are effective in thermoset resins, by dehydrating the pyrolysing polymer, forming unsaturated compounds with subsequent charring. The non-volatile polymeric phosphates thus formed provide a glassy coating for the carbonaceous layer that is forming simultaneously, inhibiting the pyrolysis reaction and shielding the underlying polymer from oxygen and radiant heat. With special synergists, a protective coating in the form of an intumescent layer can be formed in case of flaming, and phosphorus FRs are also good suppressors of afterglow and smoke. These properties make phosphorus-based retardants of particular interest in gel coats. The reduction of smoke obscuration and corrosivity favour this group of flameretardant chemicals, especially in the US market, while market penetration is broadened by their use as alternative compounds to complement standard halogenated products. Further development of halogen/phosphorus synergism could lead to wider use as a substitute for antimony oxide. High value-added, halogen-free phosphorus compounds are expected to boost sales in volume and value. FRs based on red phosphorus are effective in all types of thermosetting resins and in elastomers, often in combination with aluminium hydroxide, or magnesium hydroxide in elastomers. Clariant is one producer offering a range of red phosphorus, which has very high efficiency with only a low dosage needed to satisfy high flame-retardancy requirements. A wide range of dispersions and concentrates based on special treated red phosphorus is also available, with the advantage (compared with powder grades) that they are easier to handle and safer to transport and store. The company has an extensive range of FRs on a non-halogen ammonium polyphosphate base in its Exolit range. These are non-toxic and colourless with a broad application range, and include micro-encapsulated, synergistic, and intumescent systems, organophosphorus compounds - specially adapted to the
Modifying Specific Properties: FlammabiUty - Flame Retardants
12 7
plastics matrix and chemically bonded, for very low emissions. The electrical properties of the composite are not affected by these additives, and they have little impact on the physical properties of the laminates produced. A special grade meets the demand for halogen-free materials for pultrusion, resin transfer moulding, filament winding, and hand lay-up processes, giving highly retarded composites at a comparatively low addition rate. With this additive, at approximately 50 parts per hundred resin (phr), the Epiradiateur NF 92-501 test - one of the most stringent in Europe - can be passed with a classification of Ml, where 250 phr is required with aluminium hydroxide. With epoxy resins, the same low smoke density is produced as with polyester laminates, at addition levels of 2 0 - 5 0 phr. The aviation standard FAR 25.853 can be passed with an addition of 2 5 - 3 5 phr. A liquid-form additive is available where no powder additive can be used.
10.6 Intumescent Flame Retardants
Intumescent materials swell to many times their original thickness at high temperature, so producing a thick insulating layer with good resistance to erosion by fire and hot gases. Some low-toxicity alternatives to antimony trioxide in halogenated polymer systems work synergistically to form a char in conjunction with halogenated polymers. During combustion the vapour phase changes the flame chemistry to inhibit fire growth by removing free radicals that support combustion. Additional effects in the condensed phase produce advantages not seen with traditional antimony trioxide systems. A hard carbonaceous char is formed that further retards flame propagation and reduces the amount of smoke and carbon monoxide during combustion. Grades are thermally stable up to 2()()°C, suitable for brominated polyesters, PVC, and halogenated polyethylene, or thermally stable in all polymer systems. Table 10.6 Influence of intumescent gel coats on fire behaviour of composites (RTM process) Composite system
Flame retardancy
UP laminate/UP gel coat UP laminate/UP gel coat + Exolit AP 740 Epoxy laminate-foam sandwich/epoxy gel coat Epoxy laminate-foam sandwich/epoxy gel coat + Exolit AP 740
DIN 4102: not classified Bl DIN 4102: Bl passed DIN 5 510: not classified DIN 5 510: S4 SR2 ST2
Source: Reinforced Plastics
Expandable graphite acts by intumescence. It is grey-black with a metallic sheen and is used in some applications as a special effect pigment. Nord-Min, from Nordmann Rassmann, Hamburg, has been developed from Chinese raw material sources with flame-retarding plastics in mind. It is a halogen-free fire barrier additive, based on natural graphite flakes with intercalated acids. Depending on raw material and acid treatment, the expansion rate is up to 2 50 times the original volume. Grades treated with sulphuric acid begin to expand at around
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Additives for Plastics Handbook
200°C; with nitric or acetic acid treatment expansion starts at about 150°C. This is too low for many technical thermoplastics and a key target of development is to raise the expansion point to 3()()°C. It can be used alone as a smoke suppressant with a heat insulation effect but, for some applications, the expanded carbon layers are too unstable and other FRs, such as zinc borate, ammonium polyphosphate, or ethylene diamine phosphate, can be used as stabilizers, giving a good span of properties and applications. An intumescent phosphorus/nitrogen complex (Uniplex FRX 44-94S) gives superior thermal stability and excellent flame-retardant properties, allowing it to be compounded into polyolefins and other thermoplastics at up to 2()5°C. Bayer has developed a FR based on halogen-free chemicals, forming a carbon foam designed to prevent the fire from spreading from room to room.
10.7 Halogen-free Systems
Although bromines may eventually gain a clean bill of health, many manufacturers of plastics are playing it safe, and development of effective nonhalogenated flame-retardant grades is a top priority, while in Japan the Ministry of International Trade and Industry (MITI) has put up a budget of ¥ 2 0 - 3 0 million in 1999 (US$170 0 0 0 - 2 5 0 000) towards development of nonhalogenated flame-retardant systems, believing that the lack of them will hinder Japanese trade with the rest of the world. In Europe, BASF is looking towards nitrogen organic compounds and magnesium hydroxide for its Ultramid KR 4205 and 445 5 polyamide, and a reinforced PA6 uses a nitrogen compound, giving V-2 rating and resistance to glow wire at 96()°C with greater toughness, good stiffness, and much better flow properties, all at a lower density. The company is also working on poly(butylene terephthalate)s (PBTs): it has a non-halogenated grade (Ultradur B4()()0) which achieves V-2 and 96()°C glow wire, with low flue gas density and high tracking resistance, and predicts that it will have a V-O-rated PBT on the market. Table 10.7 Examples of halogen-free flame-retardant grades (M A Hanna Group) Base polymer
'gamidPA6
'gamid 66.6 'gamidPA66
Filler
IJL 94/glow wire test (°C)
CTI (comparative tracking index)
Example
Notes
-
600 600 500 600
-
V-2/960
600
B70() B7001JF B70G/Mi20UF B70G15UF Mul33 AB700UF
UL listed UL listed
Glass/mineral glass
V-2/96() V-0/96() V-2/96() V-0/96()
-
V2-/960^' V-0/960
600 425
A 700 A700G30USO ABOTio-35
UL listed UL listed
Glass
UL listed
Modifying Specific Properties: Flammability - Flame Retardants
129
In Japan, Teijin uses a phosphorus-based system for a halogen-free PBT compound meeting the UL 94 specification at a V-0 classification, and replacing antimony oxide with a special auxiliary. Kyowa Chemical Industry and Taheto Chemical Industries have also been developing non-halogenated retardants, using magnesium hydroxide. 70.7.7 Wire and cable
compounds
As European standards agencies have been updating their specifications to harmonize with European Union codes, one significant document to emerge has been that covering the insulation of single-core unsheathed electrical cables: European Harmonization Document HD 22.9, published by CENELAC. Single-core unsheathed cables are designed for low-voltage ( 4 5 0 - 7 5 0 V) point-to-point wiring between machinery and light sources in manufacturing plants, where they directly replace the PVC-based 649IX cable range. The specification for the insulation calls for low smoke, zero halogen material that maintains the levels of flame retardancy, cost and processing speed experienced with PVC, while reducing the potential risk of combustion products. In a fire, conventional PVC-based cables tend to produce black smoke and acid gas, arising from the use of plasticizers in the compound, and the presence of
Table 10.8 General wire and cable specifications to meet BS7211 Specification requirements Mechanical properties (BS /^'N 6()H 1 1) Minimum tensile strength Minimum elongation at break Heat-acjedproperties (BS EN 6()S 1 1) '{'ensile strength: maximum variation Elongation at break: maximum variation Hi(}h-temperaturcproperties (BS l^NCiOS J J) Pressure test at 1 ()()°C: maximum penetration Hot set test at 2()()°C 30C, mechanical stress: 0.20 Nmm^^ Maximum elongation Maximum permanent elongation
lO.OMPa 12 5% Temperature: 1 3 5°C 2°C, duration: 2 days 30% 30% 50%
100% 25%
Low-temperature properties (BS EN6()S 11) Cold bend a t - 1 5 ° C Cold impact at - 1 5°C Cold elongation at -15°C
No cracks No cracks 30% minimum
Fire test properties Flame propagation, BS 4066 Part 1 Smoke emission, lEC 61034 Halogen acid gas emission, BS 642 5 Part 1 Acid gas emission, BS 642 5 Part 2 Conductivity of effluent gases
50 mm minimum 60% maximum 0.5% maximum 4.3 pH minimum 10 |aS mm~^ maximum
Source: BICC General Compounds Division
130
Additives for Plastics Handbook
chlorine in the polymer. Replacement materials must be able to match the advantageous points (cost, processing, and flame retardancy) while removing the undesirable side eff'ects. This has led to the development of compounds containing large amounts of hydrated mineral fillers that release water during combustion to extinguish the burning, without the side effects of PVC. Early compounds of this type had poor processability and physical properties and improvements have come in the shape of new polymers that permit high loadings of these mineral fillers, plus additional chemical additives that stabilize the fillers in the polymer matrices and improve the characteristics of ageing and processability.
10.8 Combinations of Flame Retardants
Some industrial minerals have flame-retardant properties and can be used in systems to replace synthetic retardants. A number of minerals have equal synergistic action with organic halogenated and phosphorated FRs and synergistic processes have also been observed in thermosets, between borates, and other hydrated minerals. Incorporation of minerals in intumescent formulations makes it possible to manage better the morphology of the expanded structure that develops on exposure to flame. With brominated FRs, a partial substitution with minerals makes it possible to improve certain of the mechanical properties and reduce the opacity and corrosivity of the fumes generated. This in turn makes it possible to reduce the environmental hazards arising from the incineration of fumes. The use of pure talcs of fine particle and high lamellarity index, in combination with a new generation bromohalogenated compound, makes it possible to obtain optimum mechanical properties and fire resistance as well as limitation of emission of corrosive products, compared with traditional and more costly solutions. Among the minerals studied, special Luzenac talcs show a high resistance to flame in polyolefins in synergy with bromine compounds, and are recommended for various applications, such as connectors, and in electrical appliances. The talc/polymer interface characteristics influence both the mechanical and ignition resistance characteristics of the compound. Increasing the nucleating effect produced by the mineral gives better adhesion of the polymer to the filler and a stronger reinforcing effect. This effect, which is amplified by increase of specific surface, leads also to improved fire properties as a result of the energy consumed to make the crystallites melt and the limitation of heat transfer produced by a layer of mineral particles of a strong specific surface ratio. Used with other retardants, addition of melamine to mineral filler fire retardants for PP generally improves the UL 94 behaviour, eliminating at the same time the afterglow phenomenon which is typical of mineral fillers used alone. Unfortunately, this additive is not sufficiently thermally stable and requires special precautions in processing, which still have to be improved. Melamine also reduces the specific weight of fire-retarded PP, which results in an
Modifying Specific Properties: Flammahility - Flame Retardants
131
economical advantage and allows the use of relatively cheap, inert fillers such as kaolin and talc, which, used alone, do not show fire-retardant effects. Melamine is the most effective fire retardant in terms of UL 94 leading to a V-0 rank at 45% of loading; 60% of A1(0H)3 leads to a V-0 rank and 60% of Mg(0H)2 to a V-1 rank. It is necessary to increase the loading at 65% in order to get a V-1 behaviour using MgCO^. Talc and kaoHn are ineffective up to 75% of loading. The situation is different for LOI criteria: Al(0H)3 and Mg(0H)2 are the most effective and talc and kaolin (which only act as a diluent) still show a very little effect. Increased fillers concentration improves fire retardance but also impairs physico-mechanical properties. Therefore there is interest in the minimum loading conferring the minimum fire-retardance level acceptable for a generalpurpose appUcation (such as LOI 2 5; UL 94; V-0). Melamine improves UL 94 rating of PP compared with the mineral filler alone. Combustion times are considerably shortened by increasing the amount of melamine and afterglow is completely eliminated. The LOI decreases with increasing amount of melamine. A 40% melamine/25% mineral mixture shows an excellent compromise between LOI and UL 94. Magnesium and aluminium hydroxides specially coated with ZHS confer significantly increased combustion resistance and lower levels of smoke evolution to these polymers. This permits large reductions to additive loading relative to unmodified filler, without sacrificing flame-retardant or smokesuppressant performance. Table 10.9 Effect of a mineral filler/melamine combination with PP on LOI and UL 9 4 tests Filler
%
Melamine
LOI
UL94
(%)
Time of combustion (s)
AKOH)^
65 40 32.5 25
0 25 32.5 40
34.0 27.2 26.3 25.0
vo v-0 v-o v-0
5 2 1 1
Mg(0H)2
65 40 32.5 25
0 25 32.5 40
28.5 25.8 25.7 25.2
v-0 v-0 v-0 v-0
4 2 1
MgCOs
65 40 32.5 25
0 25 32.5 40
26.2 26.0 25.6 25.0
v-1 v-0 v-0 v-0
13^ 4 2 1
Kaolin
65 40 32.5 25 0
0 25 32.5 40 65
21.1 23.4 23.5 23.5 25
B v-0 v-0 v-0 v-0
-
^ Afterglow. Source: Euro-•Fillers Congress '99
9a
5 4 0 0
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10.9 Synergistic Reactions Although the mechanism is not properly understood, synergistic reactions are increasingly harnessed in the formulation of additive systems, especially in the development of multi-functional systems (such as pigments that that act as stabilizers, and vice versa, and lubricants and mould-release agents that also provide other useful properties). In FR technology, synergistic reactions do not simply produce more efficient systems. They also make it possible to reduce the amounts of other FR agents employed, and may often make a positive contribution towards delivering efficient flame retardancy within increasingly stringent FR regulations. The most important synergistic FR components at present are antimony oxide and chlorine-donor compounds. Metal oxides and other metal compounds are also promising, particularly in engineering thermoplastics compounds. By selecting the halogen source, it is possible to produce complete or partial substitutes in certain polymer systems. Compounds such as ferric oxide, zinc oxide, zinc borate, and zinc stannate have been employed successfully, most of which are effective with polyamides and epoxies when using a chlorinated FR. A range of low-toxicity alternatives to antimony trioxide works synergistically in halogenated polymer systems. During combustion the vapour phase changes the flame chemistry to inhibit fire growth by removing the free radicals that support combustion. In the condensed phase of combustion, there are additional effects producing advantages that are not seen with traditional antimony trioxide systems. A hard carbonaceous char is formed that further retards flame
Table 1 0 . 1 0 FR formulations using various synergists Formulation (wt%)
Base resin Glass fibre Dechlorane Plus Antimony trioxide Bis(tribromophenoxy)ethane Brominated epoxy Zinc oxide Zinc borate Melamine cyanurate Performance: UL 9 4 - 3 . 2 mm UL94-1.6mm LOI Tensile strength (MPa) Notched Izod impact (J m~^) CTI ^ NC = no class. Source: Occidental Chemical
Nylon 66
PBT
A
A
70 20 10
B 48 25 18
-
56 30 8 6
HiPS
ABS B
A
40 25 12
-
B
77.0
78.2
-
16.9 6.1
6.1 15.7
A
B
78
75.5
18 4
9 4 11.5
8 15
9
V-0 V-0 58 275
V-O
v-o 121.1 375
v-o v-o 98.9 250
v-o
V-o
V-0
NC^
V-1
V-0
-
-
-
-
64
347
59
67
27.25
25.25
24.75
25.75
71 300
Modifying Specific Properties: Flammability - Flame Retardants
133
propagation and reduces the amount of smoke and carbon monoxide during combustion. Typical materials are thermally stable up to 200°C (making them suitable for brominated polyesters, PVC, and halogenated polyethylene), or can be thermally stable in all polymer systems. On present experience, the most efficient synergist appears to be ferric oxide, which gives a UL 94 V-0 at 1.6 mm with only 15% total flame-retardant package (compared with up to 2 7% flame retardant and synergist with other systems). Where electrical performance is predominant, a zinc oxide synergist gives a very high comparative tracking index (CTI). Zinc stannate and zinc molybdate/ magnesium silicate in combination with zinc borate give UL 94 V-0 ratings down to 1.6 mm and the CTI values are 500 V, compared with 450 V for the same formulation using antimony oxide alone. Nylon 66 can be flame retarded with a chlorinated FR using as synergists antimony oxide, zinc oxide, zinc borate, ferric oxide, zinc stannate, zinc molybdate/magnesium silicate, and zinc phosphate. The use of mixed synergists allows the total FR package to be reduced, while often improving properties of the compound. For example, in nylon 6 and 66 and in epoxies, with mixed synergists the levels of FR agents can be reduced. PBT can be flame retarded with synergists other than antimony but, for PET at present, it is necessary to continue to use antimony oxide as a synergist. Antimony/zinc blends (60% antimony) give the same FR properties as an equal weight of antimony oxide and, where antimony is used with zinc borate, the blend can replace inorganic FRs. It can also control the afterglow problems often associated with the use of metallic oxide FRs and can deliver a lower tint strength than normal grades of antimony oxide, so allowing coloured compounds to be produced with less pigment than usual. Similarly, antimony/magnesium/zinc and antimony/magnesium/zinc phosphate complexes, acting as combined FRs and smoke suppressants in PVC compounds, offer the double benefit of a cost lower than antimony oxide and a reduction in the use of pigment due to their lower tint strength. Typically, the smoke evolution can be reduced by up to 50% and the pigment loading by up to 40%. Both types are effective in semi-rigid PVC compounds and the antimony/ magnesium/zinc blend is particularly effective in highly plasticized compounds. An antimony oxide/mineral silicate complex (from Anzon) also provides costeffective formulations with a low tint strength. It is especially suitable for plasticized PVC wire and cable sheathing and wall linings and can also be used, with a halogenated compound, in polypropylene, polystyrene, ABS and polyesters. A free-flowing chlorine-containing cycloaliphatic compound (Occidental's Dechlorane Plus - a diadduct of hexachlorocyclopentadiene and 1,5cyclooctadiene) can be used with antimony oxide, and also with other synergists, and is particularly effective in nylon 6 and 66 and epoxies. Its aliphatic rather than aromatic structure does not absorb UV radiation, so reducing the potential for discolouration after prolonged ageing. Halogenated resins can generate smoke and toxic fumes in combustion. Aluminium hydroxide (ATH) offers a halogen-free alternative, but high loadings
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are needed. Synergistic blends of halogen-free FRs based on phosphorus can meet safety requirements at a much lower loading, and so there is less impact on weight and density and mechanical properties. They also exhibit a very low smoke density, so making them particularly interesting to the transport sector. Low-smoke formulations have also been developed for wire and cable applications using as key ingredients a zinc stearate talc and an iron compound. At four minutes, they produce a Dg rating of 100 (compared with 3 0 0 - 6 0 0 for a brominated material) and 10% light transmission (compared with 0.01%). Brominated and chlorinated FRs can also react synergistically with each other in plastics compounds. OccidentaFs proprietary chlorinated FR can be used with decabromodiphenyl oxide (DBDPO) to flame retard ABS, and mixtures of chlorinated and brominated FRs can be used in polyolefins. Work on ABS formulations suggests that the highest oxygen index is obtained at a 1:1 chlorine/bromine mixture, which also gives UL 94 V-0 rating at both 3.2mm and 1.6 mm. Work with an N-alkoxy hindered amine (NOR) has shown that it can exhibit synergistic behaviour when used in combination with conventional brominated and phosphorus FRs in polyolefin fibres and moulded articles, according to Ciba Specialty Chemicals. Table 10.11 Halogen compounds found effective with antimony oxide Type
Polymer
Applications/comments
Solid chlorinated paraffins
Polyolefins, epoxies, unsaturated polyesters
Blown LDPE film
Decabromodiphenyl oxide
Polyolefins, polystyrene, ABS, epoxies, unsaturated polyesters
General purpose additive, high bromine content
Octabromodiphenyl oxide
Polystyrene, ABS
Hexabromocyclododecane
Polystyrene
Bis-tribromophenoxyethane
Polystyrene, ABS
Tetrabromobisphenol A
ABS
Ethylene bis-tetrabromophthalimide
Polyolefins
High processing temperatures, good UV stability
Bis(2,3-dibromopropyl ether) of tetrabromo-bisphenol A
Polyolefins
Melt-blendable for optimum physical properties
Ethylene bisdibromonorbornene dicarboximide
Polyolefins
Gives V-2 rating for polypropylene
Alicyclic chlorine compounds
Epoxies
Pentabromodiphenyl oxide
Epoxies, polyesters
Source: Anzon
Modifying Specific Properties: Flammability - Flame Retardants
135
Table 10.12 Flame retardants: selection guide Host polymer ABS High-impact polystyrene Expanded polystyrene Polypropylene Polyethylene Polyamide Polycarbonate PC/ABS blends PPO/impact PS blends PBT PET PVC Thermoplastic elastomers Epoxies Unsaturated polyesters Phenolics Rigid PU foam Flexible PU foam Adhesives Textiles
A
B
x
c
D X
X
X
X
X
X
X
E
F
G
H
I
X
X
J
X
X
X
X
X
X
X
X
X
X
X
X
X X X
X
X X
X
X
X
X
X
X
X
X
X
X
X X
X
X
X
X
X
X
X
X
X
X
X X X
X
X
X
X X X
X X
X X X
X
X
K
X X
X
X
X
X
X
X
X
X
X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Key:
A, dibromostyrene and derivatives; B, tetrabromophthalic anhydride and derivatives; C, hexabromocyclododecane and derivatives; D, tetrabromobisphenol A and derivatives; E, brominated diphenyl oxides; F, tribromophenol and derivatives; G, intumescent FRs; H, triaryl phosphate esters; I, bisphosphates; J, trialkyl phosphates; K, antimony-based and other synergists. Source: Great Lakes Chemical
10.10 Health and the Environment
Apart from doubts as to the intrinsic health hazards of certain FRs in plastics, the formation of corrosive substances and generation of smoke must also be considered. Recent development has tended towards halogen-free FRs, largely under pressure from legislators and environmental lobbies, but there is growing evidence that brominated compounds (which are excellent FR agents) are not the hazard that they were supposed to be. There is also considerable interest now in combining different FRs - and this is where the synergies start to appear. The synergistic action between antimony oxide and most types of halogenated FRs has been used with plastics for many years, and there are many highly efficient antimony/halogen systems in use. The combination is particularly effective, in controlled amounts, in plasticized PVC compounds. In other polymers that do not contain a halogen, a suitably chlorinated or brominated compound needs to be added to achieve the required properties. A special grade should be used if translucency is required. Antimony is not classified as a carcinogen, but it is a hazardous material and its use in most countries is controlled by the relevant regulations for conditions
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Additives for Plastics Handbook
in the workplace. The generally accepted threshold limit value (TLV) for antimony-containing dust is 0.5 mg m~^. Use as a dry powder can cause dust problems unless local ventilation is employed, but formulations that are damped, paste, or masterbatch can reduce and completely eliminate dust. Ranges of dustfree and reduced-dust (95-100% reduction) grades are also available, and masterbatches containing the chemical fully dispersed in a polymer matrix are used to give advantages in handUng and application. There is therefore some urge to replace or reduce the use of antimony oxide, and this is where synergistic reactions have a useful role to play.
10.11 Recycling
The behaviour of FRs during recycling, either by melt processing or by incineration, has been the subject of some controversy, with most of the argument centring on brominated retardants, which are particularly suitable for moulded housings of electrical and electronics equipment. The European Commission, in its draft directive for recycling. Waste Electrical and Electronic Equipment (WEEE), proposed that such components should be removed from equipment and treated separately from the rest of the waste stream, which could amount to a ban. Studies by the GfA laboratory and the University of Erlangen, Germany (commissioned by the industry-based Bromine Science and Environmental Forum - BSEF), however, suggest that there is no cause for concern. They showed that high impact polystyrene (which is one of the most widely used plastics in electronics equipment housings), flame retarded with decabromyldiphenyl ether (DecaBDE) meets the requirements of the German Chemicals Banning Ordinance, which is regarded as one of the strictest in the world. The research concluded: •
•
•
Formation of dioxins/furans: a compound containing standard loadings of DecaBDE was injection moulded and reground to simulate recycling, for five cycles, and then analysed for brominated dioxins/furans (PBDD/F). The virgin compound showed no detectable amounts. The recycled forms showed amounts of PBDD/F below the limit of the German Dioxin Decree by a factor of about 40. Debromination: the same compound was analysed for possible degradation of the flame-retardant additive. Comparison of concentrations before and after recycling showed no change, indicating that no decomposition (debromination) had occurred. Workplace exposure: a flame-retarded PS was subjected to two successive simulated recycling cycles and workplace exposure to PBDD/F was monitored during processing. At all stages, exposure to dioxins/furans was below the German workplace limits by about two orders of magnitude. A study at a recycling plant in Sweden showed that workers were being exposed to diphenyl ethers and BSEF is working with the company to
Modifying Specific Properties: Flammability - Flame Retardants
137
develop best practice for its processes. Information will be shared with other recyclers. In Japan, where manufacturers of office copiers are specifying that new lines on the domestic market must have 2 5-30% content of recycled material including use of brominated FRs, Ricoh and Fuji-Xerox have reported favourable results with a recycling loop for moulded components. Comparing recycling of an ABS compound flame retarded with a brominated epoxy oligomer with that of eight other compounds retarded with organic phosphate esters, they found that the recycled brominated ABS met the highest levels of fire safety, as represented by the classification UL 5-V, which is the test with which most manufacturers comply.
10.12 New Developments
A flame-retarding system of Si (3 wt%) and SnCl2 (2 wt%) in polypropylene and nylon 66 acts as an efficient inhibitor of gas-phase combustion, and can be considered as a new type of ecologically safe, binary fireproofing agent, according to Russian research. Researchers noted the formation of 'preceramic structures' during the high-temperature solid-phase pyrolysis preceding the combustion of silicon-containing polymer compounds. It is hypothetically possible to create a carbonized *preceramic' structure on the surface of a polymer that can exceed by hundreds of degrees the heat stability of coke-type carboncontaining structures. This could open the way to production of highperformance polymer systems for use under extreme conditions, such as are encountered in aviation or astronautics. Another new development is the use of three reactive brominated flameretardant monomers, introduced as innovative molecules which can be used as building blocks or tailored during synthesis or compounding to modify commercial resins. They are readily soluble in styrene monomer, allowing reaction into systems such as unsaturated polyesters and can also be incorporated by reactive extrusion (for example, in a glass-reinforced PBT compound). Recent work in Russia suggests the possibilities of thermoplastic elastomers for possessing inherent flame retardancy should be examined. Researchers at the Russian Academy of Sciences have been following what they claim is a fundamentally new approach to flame retarding thermoplastics, by examining the influence of the morphological features of the structure of plastic/rubber systems on their flammability. They say this could lead to a solution to reduce flammability of polymers, offering better ecological effects than conventional additive systems. Isotactic polypropylene (PP) have been compounded with an ethylene/ propylene terpolymer (SKEPT) at blends of 3 7.5 and 61.5% PP by weight. Data obtained suggest that the mixing of the two polymers leads to the formation of an interphase layer, the chemical composition of which depends on the composition
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Additives for Plastics Handbook
of the blend. Other studies have shown that the chemical structure of the interphase layer influences its reactivity. Autoxidation of PP/SKEPT blends begins with oxidation of the more active PP component, which initiates chains of oxidation in the SKEPT in the interphase layer, which appears to play a stabilizing role during oxidation. As the blend is changed from 3 7.5% PP to 61.5% PP, the interphase layer is enriched with SKEPT, leading to a reduction in reactivity. The researchers suggest that their work proposes a method for lowering the flammability of polymeric materials by modifying their morphology. With blends of polypropylene and ethylene/propylene terpolymer from 61.5 to 37.5% PP, a method for ecologically safe flammability reduction of composites has been shown.
10.13 Nano-composites
Nano-composites are the subject of intense research for a number of properties such as improved barriers to gas, higher mechanical strength, and improved flame retardancy. Plate-like particles of special clays, one nanometre (one billionth of a metre) thick by 1000 nanometres in diameter, are being studied as FRs in plastics by the US National Institute for Standards and Technology (NIST), Gaithersburg, Maryland. Initial research showed that the addition of as little as 5% of nano-sized clay particles could produce a 63% reduction in the Table 10.13 Cost and properties of flame-retarded PP System Composition (%) PP-B FR-2()-120 FR-1808
NoFR
Inorganic
BFR
Ternary
100
40 60
60
-
30 10
60 20 15 5
Sb202
-
-
Compound costs €1-1 €m^^
900 820
1450 2080
2090 2570
1650 2050
NR
V-1
V-0 >924
V-0 640
19
30
26
25
26 19 1200 8 No break
15 0.8 3800 6 23
21 4.2 1600 3 30
21 3.5 1900 5 No break
Flammability (s - 3.2 mm) UL94 Smoke density (NBS DM flaming mode) L0I(%02) Properties Tensile strength (MPa) Elongation at yield Flexural modulus (MPa) Charpy impact (kj m^^ notched) Charpy impact (kJ m"^) Source: AddconWorld 2000/Eurobrom BV
Modifying Specific Properties: Flammability - Flame Retardants
139
flammability of nylon 6. More recent studies have shown that flame retardancy in many other polymers can be boosted by dispersing clay at the molecular level.
10.14 Commercial Trends
According to the producer Eurobrom BV, the world FR market is worth more than US$2.3 billion, embracing some 1 5 0 - 2 0 0 grades, based mainly on halogens, phosphorus, inorganics, and melamine compounds, and making up about 2 7-31 % of the US$8.6 billion performance additives market. The US and European markets are estimated at about the same (respectively US$758 million and US$800 million per year). In volume terms, researchers BCC and lAL put the US and Western European segments at, respectively, 344 000 tonnes (1998) and 316 000 tonnes (1996). Table 1 0 . 1 4 Consumption of FRs by major region 1989 USA Western Europe Japan Other Asia Total
1992
1995
1998
Average annual growth 1 9 9 8 - 2 0 0 3 (%)
470 332
480 559
585 631
630 685
2.8-3.6 3-4
250 n/a >1052
317 n/a >1356
348 >244 1808
373 >390 2078
3.8 5.1 3.5-4.0
Source: SRI Consulting
Table 10.15 Consumption of FRs by type and region, 1 9 9 8 (thousand tonnes)
Brominated Organophosphorus Chlorinated Alumina trihydrate Antimony oxides Other types Total
USA
Western Europe
Japan
Other Asia
Total
Value (US$ million)
68.3 57.1 18.5 259.0 28.0 42.7 474.6
51.5 71.0 24.7 160.0 23.0 29.8 360.0
47.8 26.0 2.1 42.0 15.5 10.5 143.9
97.0 19.0 20.0 >9.0 >20.0 >83.0 > 165.0
264.6 175.1 65.3 >470 >86.5 > 149.5 1144.5
790 435 116 260 327.5 n/a 2078
Source: SRI Consulting
In value terms (%), the main 'families' of FRs are: brominated FRs, 39; phosphorus-based, 23; inorganics, 22; chlorinated, 10; melamines, 6. For the foreseeable future, the largest single flame retardant material will continue to be alumina trihydrate, with a moderate growth rate of 3.1% a year, but continuing to offer the most cost-effective system. Other types, particularly brominated compounds, will show stronger growth rates. Roskill estimates that
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Additives for Plastics Handbook
world production of brominated FRs is growing at an average rate of 8% a year. FRs now represent the largest single use of bromine, accounting for about 30% of total consumption. World production of bromine should reach 468 000 tonnes a year by the end of the twentieth century. Consumption of chlorine-based compounds, however, is depressed (to 2.1% a year) by environmental concerns, but interest in reducing smoke obscuration and corrosion favours use of phosphorus-based compounds. Other FRs (mainly boron-, molybdenum-, and nitrogen-based compounds) will continue to find markets as synergists and partial replacements for higher-priced chemicals. Magnesium hydroxide is attracting interest. Differing pressures will show themselves in the different materials, as legislation for health and safety and the environment comes to bear on consumer and technical products, which use large quantities of engineering thermoplastics. • • • • • • •
Polyolefins: the market is for non-blooming, non-plate-out types; there is also a demand for non-halogens and improved thermal stability. Styrenics: demand is for non-halogens for ABS and high-impact polystyrene; there is movement away from resorcinol diphosphate in PC/ ABS blends. Engineering thermoplastics: the need here is for high thermal stability driven by need for miniaturization; non-halogens; there is wider use of polymer blends for FR performance. PVC: there is increased concern over smoke generation; better lowtemperature flexibility is required in wire and cable. Thermosets: non-halogen PCBs are now made to FR-4; higher heat distortion temperatures. Polyurethanes: compatibility with CFC replacements is needed, and nonDPO-basedFRs. Phosphorus: interest in reducing smoke obscuration and corrosion favours use of phosphorus-based compounds, which, with a growth rate of 7.0%, will become the third-largest FR additive.
CHAPTER 11 Modifying Specific Properties: Conductivity - Antistatic/Conductive Additives Although it consumes only about 5-7% of plastics, the electrical and electronics market sector exercises large demands on additives, which will certainly grow in volume and value. Covering both consumer and industrial products, 'E and E' involves housings and enclosures for all types of equipment and an increasing volume of moulded connectors and circuitry. Insulation and sheathing for wire and cable, with its own specific demands, can also be included. As well as the stabilizers and processing aids required for most massproduction moulded components, E and E has a significant and growing sector where some form of positive conductivity is needed (at the least, to prevent internal static discharge, but increasingly to shield delicate components against external electromechanical interference).
Table 11.1 At a glance: anti-static/conductive additives Function
Reducing/eliminating the tendency of plastics to retain an electrostatic charge, by providing a surface layer (often activated by atmospheric moisture) or establishing a conductive network within the plastic compound.
Properties affected
Attraction of (especially) lightweight plastics (films, fibres, etc.) to each other and to other materials; improved operation of high-speed machinery (e.g. for packaging); shielding equipment against electromagnetic interference; reduction/elimination of spark hazard in handling electronics, chemcials, medical equipment.
Materials/characteristics
Liquids: quaternary ammonium, polymeric anti-statics. Solids: carbon black, coated metal particles, glass spheres. Intrinsically conductive polymers: polyanilines.
Disadvantages
Possible effect on surface, limiting finishing treatments (e.g. printing); susceptibility to moisture.
New developments
Improved conductivity at lower addition levels; better/more uniform dispersability.
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Additives for Plastics Handbook
The development problem is how to impart long-term and even permanent anti-static properties, without the possibility of migration or leaching. A polymer solution may be the way. A vital requirement for effectiveness is limited compatibility (solubility) with the host polymer and controlled mobility (rate of diffusion) in the matrix. For polymers with a low glass transition temperature (such as polyolefins), continuous migration of the anti-static agent is important to achieve the desired effect, while for polymers with a glass transition rate considerably above ambient temperature (such as PVC, ABS, and polystyrene), the decisive factor is the compatibility at the moment of cooling. A wide range of additives can be compounded into both thermosetting and thermoplastic composites to produce the required degree of conductivity, including reinforcements (such as fibres of carbon or metal, or metallized fibres) or powders. Table 11.2 Classification of electrical insulation/conductivity Surface resistivity (^/sq)
Type of material
10^4
W W
Insulative plastics
W IQi"
10^ 10« 10^ 10^ 10^
Dissipative composites
10^ Conductive composites 10^ 10 10-1 10-^ 10-^ 10-4
ESD shielding composites (carbon powder/fibre)
10-
Metals
Antistatic agents are added to plastics before or during processing. In many plastics they migrate continuously to the surface, where a deposit of the material may occur, even if it is frequently removed. Possible interactions with the polymer must be borne in mind when choosing the anti-static additive (such as lubrication, haze, and effects on thermal stability). Some grades of anti-static agents must not be discharged into waste water but, if handled correctly, anti-static agents are available that present no problems. Suitable grades are also available that comply with most food regulations.
Modifying Specific Properties: Conductivity - Antistatic/Conductive Additives
143
11.1 Classification of Antistatic Additives
Antistatic additives can be classified by application method, as internal and external, and by chemistry, as anionic, cationic, and non-ionic. Internal agents are normally compounded at 0.1-3.0% by weight and have a slight compatibility with the polymer, but the molecule has a hydrophilic head forcing it to migrate to the surface and attract moisture from the environment, which increases the surface conductivity. These are easy to use and have low addition rates, often also providing other benefits such as improved processability and mould release. External additives are basically the same type of molecule, but are applied to the surface of the processed product, as a water- or alcohol-based solution, by spraying, wiping, or dipping. They have immediate effect but are susceptible to accidental removal and the anti-static effect cannot be reinstated. The main cationic anti-static agents are alkyl ammonium salts, with a long molecular chain giving good compatibility with the polymer. They are widely used with PVC, but tend to be heat sensitive. Other anti-static agents are glycerol stearate, acid esters, ethoxylated amines, and others, which act by migrating to the surface, attracting moisture and ions from the air, and so setting up a conductive path to dissipate static charges. Anionic anti-static agents are usually alkali salts of alkyl sulphonic and sometimes phosphonic or carboxylic acids. Sodium alkyl sulphonates are recommended for styrenics. Non-ionic anti-static agents are the most important group, comprising ethoxylated alkylamines or amides, fatty acid esters, and esters or ethers of polyols. Glycerol monostearate (GMS) and ethyloxylated amines (EA) make up more than 50% of the total classical anti-statics market. They are mainly used in polyolefins and styrenics. There is a further class of non-ionics based on amides that overcomes the corrosiveness of EA, which can harm packaged goods. Permanent anti-static additives have been the subject of much development, including highly conductive fillers such as carbon black and incorporation of intrinsically conductive polymers such as polyaniline and polythiophene. While being effective, these suffer from disadvantages in their effect on colour and limited solubility. Special care is needed during processing to build up an antistatic network throughout the polymer, processing at a temperature higher than the melting point of the additive.
11.2 Conductive Additives
Conductive additives usually come in granular or fibre form, offering a wide range of conductivity, according to their nature and the level of loading. Compatibility with the host polymer is a key criterion, as is processability. In conjunction with FRs, they are now a key sector for E and E applications, where they come under increasingly strict regulation regarding performance and evolution of fumes, while the proposed extension of recycling legislation in
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Europe to cover Waste Electrical and Electronics Equipment (WEEE) is proving a point of serious controversy throughout the industry. Thermoplastics have high resistivity (typically 10^^-10^^ ^ ) and are receptive to build-up of static electricity. The most familiar manifestation of this is attraction of dust to the surface of a plastics product. Among the more serious consequence (in ascending order) are: impairment of the operation of fast machinery such as flexible packaging machinery, electric shocks, and discharge as sparks - which can have catastrophic results in areas where there is risk of the presence of explosive gases. In compounding for anti-static properties, the easiest solution is to add carbon black, which makes the plastic more or less electrically conductive (but also makes it black). Where feasible it is used, and most 'conductive' compounds are based on carbon black. For most electrical applications, there are two types of compound, related to performance, discussed below.
11.3 ESD (Electrostatic Discharge) Compounds
These compounds have a resistivity in the region of lO^'-lO^^ ^ / s q and are designed for use where slow and controlled dissipation of static charges is required. EMI shielding compounds, for protection of electronic components from electrostatic discharge, offer a surface resistivity of lower than 10^' ^/sq, with volume resistivity of lower than 1 Q cm and up to 5 5 dB attenuation. Compounds dissipate a surface charge and can be processed by normal thermoplastic methods. Typical applications are boxes and in-plant handling containers for electronic components or chemicals where there is a risk of explosion from a spark. Medical products also increasingly have ESD specification, especially for use in an operating theatre. Packaging products such as flexible films also require some form of anti-static treatment, either by means of an additive, or by using external field generators.
11.4 EMI (Electromagnetic Interference) Compounds
These compounds screen out undesirable electrical frequencies by means of additives which form a shield. Typical applications are housings for equipment vulnerable to EMI. Because of the nature of the additive shield, they may require special processing, but better understanding of the technology is leading to development of formulations that are compatible with injection moulded thermoplastics, such as ABS.
11.5 Metallic Additives
EMI shielding compounds based on stainless steel fibres are supplied as masterbatch compounds that can be added at low levels, ensuring minimal effect
Modijying Specific Properties: Conductivity - Antistatic/Conductive Additives
14b
on colour and processability. The compounds are non-abrasive and can be pigmented. Shielding levels of 50 dB can be obtained with 1% addition of fibres, by volume. With the widespread use of clean room systems for manufacturing and packaging critical products (such as medicals and pharmaceuticals) there has also been growing interest in improved materials for construction and fitting out. The specialist formulator TBA Electro Conductive Products caters for this need with its new ECP 2000 static dissipation series, designed for 'clean room' applications where the need is for washability, low off-gassing, and low particulate contamination. Offered in a range of polymer matrices, the formulations are permanently conductive and can be moulded on standard equipment, in colours. Potential applications include packaging for medical products, in-process carriers, fixturing devices, chip rails, vacuum tubing, and machinery components. Extremely thin-drawn filaments of stainless steel have been developed by Bekaert under the name Beki-Shield, meeting EMI and ESD specifications at very low loadings. Maximum effectiveness is reached at about 15% by weight. The mechanical and physical properties of the plastic are only minimally affected and
Figure ILL. Carbon black additives can also conduct electricity, ojjeriny a simple and effective means of providing anti-static properties or EMI shielding. (Photograph: Cabot Corporation)
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it is claimed that designers have the same freedom as when working with the original resin. While not used as reinforcement, the fibres can be used with reinforcing fibres without degrading conductivity. In a plastics compound they create an electrically conductive network in the moulded part. The fibres are available as a continuous bundle and in chopped fibre form. The latter are bound with polymeric binders specific for various resins, forming concentrates of stainless steel fibres, designed for easy dispersion into the matrix. Dry blends or melt compounds with the fibre are also available worldwide. Work on metallic additives has been particularly to the fore in Japan. A process to produce very fine metal fibres has been developed at the Nippon Institute of Technology (NIT), Saitama, Japan, and has been commercialized in a joint venture with NV Bekaert, Belgium, under the name Bekinit KK. Described as coil shaving, it is faster and more versatile than traditional methods. Fibres of 2 0 100 Jim in diameter can be produced from titanium, aluminium, nickel, copper, and stainless steel, which offer improved conductivity in plastics compounds. Filter media, heat-resistant fabrics, and motorcycle silencers are among other potential applications.
Figure 11.2. Carbon black particles. (Photograph: Cabot Corporation)
Modifying Specific Properties: Conductivity - Antistatic/Conductive Additives
147
Table 11.3 Performance of stainless steel fibres at various loadings Vol.% fibre
Weight % fibre
Volume resistivity (^cm)
Performance (30-1000 MHz range of shielding)
0.25-0.5 1.0 1.5 >1.5
4 8 12 15
2 0.5-2 0.1-0.5 <0.1
ESD protection 3 0 - 5 0 dB EMI shielding 50-60 dB EMI shielding > 60 dB EMI shielding
Source: Bekaert
Table 11.4 Comparison of different conductive systems
Loads for comparable ESD behaviour (wt%) Cost of part Reinforcement Reduced impact strength Moulding Colour Influence on shrinkage Riskofwarpage Emigration of carbon (sloughing) Toxic contamination
Carbon black
Pitch carbon fibres
PAN carbon fibres
Stainless steel fibres
40
20
15
5
Low No Somewhat Reduced Black only Small Small High High
Medium Yes Yes Reduced Black only High High Medium High
Medium Yes Yes Reduced Black only High High Medium Low
Medium No No No influence Colours possible No No No Low
Source: Bekaert
11.6 Coated Polymers
A process for coating synthetic fibres such as polyester and nylon and also natural fibres including cotton with metal to produce a shield against electromagnetic radiation (EMR) has been developed by Daiwobo Co, Japan. Using a palladium catalyst, the coating is a film of copper or nickel less than 1 ^m thick. It costs about 25% as much as silver-plated fibres and provides shielding up to 99.9% of EMR over the range of frequencies from 30 MHz to 30 GHz. It is being sold for applications in cellular telephones and personal data devices. Conductive systems are a fast-growing group of speciality thermoplastics and thermosets, but they have disadvantages, particularly in compatibility, processing with the required high loadings, and reduction in mechanical properties. However, the use of inherently conductive polymers (ICPs) - also known as synthetic metals - is generally limited by their poor thermal stability (usually up to about 180°C). A solution that addresses both deficiencies could be a high-performance conductive filler that is produced by polymerization deposition of a coating of an ICP onto the surface of carbon black particles (which are also conductive).
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Developed by Eeonyx, USA, it is claimed that conductive blends can be produced in a number of polymer matrices with improved electrical and mechanical properties. Melt flow and compounding are improved, with easier end-product fabrication. For example, in some systems (such as ABS, nylons, and polyesters) only half as much of the additive is needed to achieve the same conductivity level as a typical carbon black loading. The coated particles possess greater thermo-oxidative stability than ICPs (300-3 50°C), so accommodating the majority of thermoplastics and thermosets currently used in industry without degradation or loss of conductivity. The filler has a greatly reduced surface area and pore volume compared with the original carbon black. In a number of plastics matrices, conductive blends can be produced with improved electrical, and mechanical properties.
11.7 Intrinsically Conductive Materials
Several companies have developed intrinsically conductive polymers. Notable is a range of conductive dispersions based on ICPs such as polyaniline and polypyrrole, developed by DSM and marketed under the name ConOuest. The first commercial applications are emerging, and the company claims to have overcome the problem of poor processability in common solvents by using a dispersion of a conductive polymer and a waterborne binder resin. This uses only a low percentage of the conductive polymer and, as the functional part is located in the optimal position, the coating is more cost effective. The carrier system - basically a polypyrrole shell and a polyurethane carrier resin - can be modified by changing either component. A range of additives based on polymeric or inorganic powders has also been developed which could be used as alternatives to carbon black to achieve 'tuneable' conductivity or avoid contamination. Mechanical properties are relatively good due to the low loading required. At very thin layers, the coating can be more transparent than is usually observed with standard polypyrrole systems, because the high conductivity is obtained with only a low amount of polypyrrole. There is a relatively high absorption of infra-red radiation. At a layer thickness of 2 jim visible light transmission is 90%, reflecting 35% of infra-red radiation. At higher layer thickness, close to 100% reflection can be achieved. A possible application might be for treatment of camouflage netting.
11. 8 Moulded Circuitry
Given that some basic technical problems can be overcome, metallic additives have an exciting future with the possibility of moulding the complex electrical and electronics circuits in electronics equipment, as are used now in automobiles, rather than using printed circuitry. While printed circuits go a long way, the next stage is to mould three-dimensional circuitry, and mixing metallic
Modifying Specific Properties: Conductivity - Antistatic/Conductive Additives
149
particles into the compound makes it possible to build the circuitry into the components while they are being moulded. There has been some work aiming at using standard injection moulding equipment and the project has been assigned to Sinto Kogyo for further development.
11.9 Recent Developments
Some recent applications illustrate the present scope of conductive additives. A non-migrating LDPE-based carbon black compound (Cabelec 4540) is combined with additives that facilitate opening and sealing of conductive bags for electronics components. The special carbon black absorbs only little moisture and so does not usually need to be dried before processing. Bags made from the compound can be used for packaging explosive powders, pigments, and other products needing to be protected from static discharge. The typical tensile strength is 19.4 MPa and elongation at break is > 550%. The typical surface resistivity on 100 jim film is 10 ^ ^/sq. An innovative carrier for semiconductor wafers designed in the USA is made of two polymers: polycarbonate over-moulded with a speciality conductive PEEK compound from RTP. The polycarbonate base gives dimensional strength at a low cost, with transparency and toughness (clear, red, blue, or green tints provide easy identification from all angles), and the conductive PEEK overmoulding provides an electrical grounding path and protective lining for the carrier in areas where it may come in contact with a wafer or production or handling equipment. Although the usual carrier in masterbatch systems is LDPE, electrically conductive compounds have been introduced based on polypropylene and polyacetal. Cabot's Cabelec 3898 is a PP compound that is particularly suitable for the production of corrugated sheets used for packaging of products (such as electronics components) that are sensitive to electrostatic discharge. It is said to show an excellent balance of rigidity and impact strength. It offers particular advantages to the sheet extruder by non-hygroscopic behaviour, easy processability (close to nonconductive PP grades) and ability to reuse production scrap without loss of the conductive properties. The acetal compound Cabelec 3899 is suitable for injection moulding and is designed, typically, for applications such as automobile fuel inlets, where permanent conductivity, coupled with good dimensional stability, is increasingly required to reduce explosion hazards. For greater durability, Croda is offering amine-free, long-term anti-statics (for applications in sensitive electronics packaging), using materials that have never been used for this purpose before. The additives are also thermally stable and suitable for use in a wide range of polymers. Permanent anti-static properties are claimed to exist in certain grades of Elf Atochem's Pebax polyether block amide engineering copolymers, which has led to their use as additives in ABS and other thermoplastics. In some cases it has been found advisable to include a compatibilizing agent. Pebax MV 1074 and MH 1657 have surface resistivities
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lower than 3 1 0 ^ ^ cm~^ under the ASTM D 257 standard, and a half-discharge time of less than 1 second. In concentrations of 5-10%, they can impart permanent anti-static properties to the matrix polymer, effective across a wide range of moisture levels and in the event of abrasion of the moulded product. They have no effect on colour or on the flexural modulus of the host polymer, and will not migrate. They also possess excellent thermal stability, breaking down at above 400°C - well above the processing temperature of most thermoplastics. A system developed by Ciba in its Irgastat range is based on the principle of hydrophilic copolymers in which additive filaments form a percolating system, with diameters of 0.2-15 |Lim. These are used mainly in styrenics and acrylics but, for polyolefins, high loadings of up to 30% would be required, while mechanical properties are significantly changed. The latest developments, however, point towards systems that are also suitable for polyolefins, with a larger processing 'window' to include low-density polyethylene blown film. These grades are colourless, migration free, show no deterioration of the surface, and are effective at very low relative humidity. Very pure superconductive carbon blacks are produced by Akzo Nobel under the name Ketjenblack. Due to their unique morphology, substantially lower amounts can be used compared with conventional blacks, giving improved processing and mechanical properties for electroconductive products. High concentrates of anti-static, slip, and anti-blocking additives on a polymer carrier are offered by Akzo Nobel, using its Nourymix patented technology. They have uniform granular form and are easy to handle and pre-mix with polymers.
CHAPTER 12 Modifying Processing Characteristics: Curing and Cross-linking Table 12.1 At a glance: curing systems Function
Effecting cross-linking of thermosetting resins: initiation of reaction, control of speed of reaction.
Properties affected
Resin production: fundamental to development of desired mechanical and chemical properties.
Materials/characteristics
Organic peroxides. Cobalt/amine/vanadium compounds. Aliphatic amines. Ketones, anhydrides, etc.
Disadvantages
Special precautions required in storage and use: danger of lire, health and safety precautions must be observed.
New developments
Improved stability; better formulations for health and safety in the workplace.
12.1 The Curing Process
Thermosetting resins differ fundamentally from thermoplastic resins in that they are prepared for processing in an uncured state, and they are cured during the processing stage, by the application of heat with the assistance of chemical agents, in a once-only reaction. This makes them (usually) hard and infusible, with relatively good resistance to heat. Cross-linking is also an important, but highly specialized, sector of thermoplastics processing, especially for the production of wire and cable sheathing. Curing agents are therefore an important group of additives that influence curing: they can initiate the cure by catalysing and promoting, or can control the cure by accelerating or retarding it. Thermosetting resins are processed by means of a change in their molecular structure, in which, under certain circumstances, the individual molecular chains can be made to link up in an irregular fashion, forming a solid infusible network. This is called 'curing', and will happen, in time, by normal processes (in fact, it was this phenomenon which first attracted the interest of researchers in the last century). For industrial purposes, curing (or 'cross-linking') can be activated by means of special chemicals, heat, or irradiation.
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12.2 Terminology
Several different terms are used in the industry to cover curing agents: 'catalyst' (not technically accurate, but widely used), 'hardener', or 'initiator'. 'Activators' (also called 'promoters' or 'accelerators') are used to speed up the cure. 'Inhibitors' perform the opposite function.
12.3 Curing Agents, Accelerators
Peroxides are used as catalysts for unsaturated polyester resins, generating free radicals and causing cross-linking, acting at either elevated or ambient temperature. Development of peroxide and peroxyester systems for room temperature curing of thermosets is a priority. Curing of polyurethane systems requires a balance between control of the isocyanate/polyol reaction (causing cross-linking) and isocyanate/water reaction (causing foaming). Replacement of CFCs must also take this into account. Polyester resins are usually cured by addition of special chemicals that decompose to free radicals, offering a simple technique that can easily be controlled, regarding rate and length of cure. Polyester resins can also be cured Table 12.2 Applications of organic peroxides A Cross-Uukinfi PE CM EAM EPM EKM VMQ SBR Curincj Contact moulding Rotational casting Continuous processing Press moulding Casting Coating Wood varnishes Wood impregnation Other Styrenation Graft copolymers PP degradation Furane curing Flame retardancy Additives Source: Peroxid-Chemie
B
C
X
D
E
X
X
X
X
X
X
X
X
I
J
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
F
G
H
K
X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X X
X
X
X X
X X
X
X
X
X X
X
X X X
Modifying Processing Characteristics: Curing and Cross-linking
153
by heat or irradiation and newest technology is to offer resins that cure under the effect of UV. The usual chemical curing agent is an organic peroxide, which is a more or less stable chemical compound comprising carbon, hydrogen, and oxygen, easily decaying in extremely active radicals. For curing polyester resins, a wide range of organic peroxides is available for various thermal stability requirements, ranging from compounds which decompose rapidly to free radicals at ambient temperature to those active only at higher temperatures. The former are not normally used for curing unsaturated polyester resins. More often used are peroxides that are stable at ambient temperature and decompose at 50-150°C. At ambient this is not sufficiently active to cure the resin, and reducing agents such as tertiary aromatic amines, heavy metal salts of cobalt, vanadium, and iron are used to accelerate decomposition. Organic peroxides are derivatives of hydrogen peroxide. They can be used to initiate a polymerization reaction, and influence the quality and final properties. In the context of additives, they can be used to cure unsaturated polyester resins, and cross-link thermoplastics (such as polyethylene and EVA) and elastomers. There is a very large number of different types. They are produced in liquid form and as masterbatch, in powder and granule, paste, and flake, and as dispersions. Persulphates (inorganic diperoxysulphates of ammonium, potassium, and sodium, and triple salt potassium monopersulphate) are used as initiators in the polymer and fibre industry, as weU as other applications in other industrial sectors. Table 12.3 Cross-linking with peroxides: dosage of peroxide per 1 0 0 parts polymer Polymer
Perketale
Dicumyl
Di-benzene
Dimethyl hexane
Polyethylene Chlorinated PE Ethylene vinyl acetate Natural rubber/isoprene Polybutadiene Chloroprene Styrene/butadiene Ethylene propylene/EPDM Cross-linking temperature (°C) Manufacturing temperature (°C)
1.5-7.5 6.8-10.5 2.6-5.2 2.3-4.6 1.0-2.0 1.1-3.0 1.9-4.0 6.9-11.0 150 110
1.4-6.6 6.1-9.4 2.4-4.5 2.0-4.0 0.9-2.0 1.0-2.6 1.7-3.6 6.0-10.0 170 120
0.8-4.0 3.8-5.8 1.5-3.0 1.3-2.4 0.5-1.1 0.6-1.6 1.1-2.2 3.8-6.2 180 130
1.2-6.3 5.7-9.1 2.2-4.4 1.9-3.8 0.8-1.8 1.0-2.6 1.6-2.4 5.8-9.5 180 130
Source: Perg an
12.4 Inhibitors
Compounds that prevent undue polymerization of the resin are called inhibitors, typically monohydric or polyhydric phenols and some quinones. They are usually added during manufacture of the resin to ensure stability in storage.
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They can prolong the pot Ufe of a resin system containing peroxide and accelerator, particularly with cobalt systems. Inhibitors can also influence the ratio of cure to gel time, as they mainly prolong gel time. p-^Butylcatehol extends gel time and pot life at room temperature and at elevated temperatures; 2,6-di-t-butylparacresol is used with BPO/amine systems, to give lower peak exotherm and gradual cure.
12.5 Curing with Accelerators
Use of accelerators to aid curing is the most popular method: curing is possible at below 100°C with organic peroxides in combination with accelerators, or preaccelerated resins. Post-curing at 80-120°C is normally required. The normal curing system is a ketone peroxide (based on either methyl ethyl ketone, cyclohexanone, or acetyl acetone) with cobalt octoate or naphthenate. Alternatively, diactyl peroxides such as benzoyl peroxide are accelerated with diethylaniline, dimethylaniline, and dimethyl-p-toluidene. Amine acceleration gives a fast curing cycle but can produce tackiness in thin layers and very strong discolouration during ageing. A ketone peroxide with cobalt acceleration therefore forms the most popular curing system. • • • •
Cobalt: cobalt octoate (mainly used with ketone peroxides for polyesters at room and elevated temperatures); Amine: dimethylaniline with dibenzoyl peroxide at room temperature, normal/long gel times), dimethyl-p-toluidine (very short gel times); Cobalt/amine: very high reactivity with ketone peroxides for very fast cure (for example, polymer concrete); Vanadium: special for ketone peroxide, hydroperoxide, and peroxy esters, giving short gel times, and very high cure speed.
12.6 Curing without Accelerators
Without use of accelerators, external heat is required, making a system suitable for mechanical processes, such as hot press moulding and continuous impregnation of sheet and profile. Temperatures in the range 120-160°C are used to cure in a short cycle: accelerators offer no advantage as the rate of cure depends on thermal decomposition of the peroxide, and typical cycle times are 1 10 minutes. Usually a combination of long shelf life of the uncured compound with short curing cycle is required, calling for adequate thermal and chemical stability. Organic peroxides for high temperatures are peresters and perketals. Low initiation temperature with adequate curing performance is given by dimyristyl peroxy dicarbonate or methyl isobutyl ketone peroxides (in the latter case limiting shelf life to a few hours). Combinations of peroxides can be used: the more active types reduce initiation temperature while more stable types give a better degree of cure.
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155
12.7 Selecting a Curing System
A number of factors must be considered in processing conditions, in descending order of importance: • • • • •
high-output production; batch or continuous process with/without external heat; moulds closed or open to air; required shelf life of the activated compound: immediate/days/weeks/ months; possibility of using resin + peroxide and resin + accelerator as separate components in a 'two-pot system'.
Thick-walled castings or thermally insulated mouldings, which can reach a peak exotherm of over 200°C, producing cracks from internal stress or shrinkage, can be moulded better with less-active curing systems. Surface coatings (with no exotherm and slow cure with possible air inhibition) can better use very active curing systems. Where colour is important, accelerators must be kept to a minimum: amines are not suitable, ketone peroxides/metal salts are preferable.
Table 12.4 Curing systems and w h e n / w h e r e to use them Type/form
Main characteristics
Ketone peroxides for 'cobalt curing' at ambient temperatures Methyl ethyl ketone peroxide: Standard for all resins, including bisphenol liquid, high activity and vinyl esters; relatively short gel times, moderate heat evolution, little internal stress
Processes A, B, c, D, E, f
Liquid, low activity
Versatile type for all resins, particularly vinyl esters; relatively long gel times, short mould release times; good for large parts and/or use in hot countries
A, c, D, E, G
Liquid, superactivity
Special for buttons/button sheets
a,b,d, e,f
Acetyl acetone peroxide; liquid, normal activity
Versatile type for ortho-or isophthalic-based resins; relatively short cure time, strong heat evolution; suitable for thin-wall mouldings
a,B,C,d,F,G
Liquid, low activity
Specialfor thick-wall mouldings; variable gel times, reduced peak exotherm, short mould release times
a,b,c
Liquid, low activity
Special for very thick-wall mouldings; relatively long gel times, little heat, acceptable mould release times
a, b, c
Cyclohexanone peroxide; Uquid, normal activity
Versatile type for nearly all resins; variable gel times, moderate heat, little stress; suitable for large or thick-wall mouldings
a
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Type/form
Main characteristics
Processes
Liquid, high activity
Versatile type for nearly all resins (also vinyl esters); variable gel times, relatively short mould release times, reasonable mould release factor
a,b,C,E
Benzoyl peroxide for 'amine curing' at ambient temperatures Dibenzoyl peroxide: 50%, Rapidly dissolving in all resins, include, bisphenol a, b, c, g powder with phthalate A and vinyl ester; variable gel times, strong heat evolution, relatively short mould release times; no accelerator required above 70-80°C 50%, suspension
Pourable/pumpable suspension, dissolves rapidly; curing performance as above
a, b, c, G
40%, suspension
Pourable/pumpable suspension, dissolves rapidly; special type for easy dosing/metering; curing performance as above
a, b, c, G
Organic peroxides for curing at 60-120° C Dimyrstylperoxy dicarbonate: Special type for curing above 50°C, but only with techn. pure, flakes more thermally stable peroxides; suitable for all resin types
f
Methyl isobutyl ketone peroxide: liquid, normal activity
Versatile type for curing above 5 5°C, possible with e, f more thermally stable peroxides and/or cobalt accelerators; suitable for all resin types
t-Butylperoxy-2-ethylhexanoate: techn. pure, liquid
Versatile type for curing above 7()°C, possible with more thermally stable peroxides and/or cobalt accelerators; suitable for all resin types
f.g.h
Dibenzoyl peroxide: 50%, power with phthalate
Versatile type for curing above 7()°C, possible with more thermally stable peroxides and/or amine accelerators; suitable for all resin types
U
Cumene hydroperoxide: 80%, liquid
Special type for curing above 8()°C, with cobalt accelerators
1,1 -Di(t-butylperoxy) trimethyl cyclohexane: liquid, high activity
Versatile type for curing about 80°C; 'quick-set' in range 120-15()°C for hot press moulding SMC or BMC; can be accelerated by promoters
F,G,H
50%, solution in aliphatics
Special for SMC/BMC at 130-160°C without accelerator; not sensitive to fillers, pigments and promoters
g,h
1,1 -Di(t-butylperoxy) cyclohexane: Standard for SMC/BMC at 130-160°C without 50%, solution in alphatics accelerator; not sensitive to fillers, pigments and promoters
g.H
t-Butylperoxy benzoate: techn. pure, liquid
Standard for SMC/BMC at 130-160°C; can be accelerated by promoters; sensitive to some fillers and pigments (e.g. carbon black)
50%, powder with chalk
Standard for granulated moulding compounds at 130-160°C without accelerator; can easily be mixed in as free-flowing powder
Modifying Processing Characteristics: Curing and Cross-linking
Type/form
Main characteristics
t-Butylcumyl peroxide: techn. pure, liquid
Special for SMC/BMC with deep flow at 130-160°C; not sensitive to fillers, pigments and promoters
1,3-Di(t-butylperoxy isopropyl) benzene: tech. pure, flakes
Special for granulated moulding compounds at 140-1 70°C without accelerator; not sensitive to fillers, pigments and promoters; also available as 40% powder with chalk
Accelerators Cobalt octoate: in phthalate with 1% cobalt
157
Processes
h,I
Standard for ortho- or isophthalic acid resins with ketone peroxides or peresters; gel and cure times vary according to peroxide; 20-100°C
In xylene with 6-10% cobalt
Special for large batches or high usage; can be diluted; performance as for above
A,B,C,D,e, f.g
Cobalt octoate/dimethyl aniline: liquid mixture in phthalate
Special for bisphenol-A or vinyl esters, with ketone peroxides or peresters; short gel/cure times; 10-100°C
a,b,c,d,E,G
Dimethyl-p-toluidene: 10% solution in phthalate
For short gel/cure times with dibenzoyl peroxide; suitable for all resins; 10-1 ()()°C
a, c, G
Dimethyl aniline: 10% solution in phthalate
For medium gel/cure times with dibenzoyl peroxide; suitable for all resins; 1 5-10()°C
a, b, c, G
Diethyl aniline: 10% solution in phthalate
For long gel/cure times with dibenzoyl peroxide; suitable for all resins; 1 5-l()()°C
a, b, c, g
Inhibitors Di(t-butyl)-p-cresol: techn. pure powder, 40% solution in xylene (SETA flash point-30) t-Butylcatechol: techn. pure, powder, 10% solution in styrene (SETA flash point-31)
Prolongs up to weeks/months shelf life (gel time f, g, H. of resin + peroxide) at ambient temperature; effect on cure times diminishes with rise in temperature; efficient with many types of resin and peroxide Prolongs up to many hours pot life (gel time of resin + ketone peroxide + cobalt accelerator) at ambient temperature; mould release factor improved; also efficient at elevated temperatures
a, c, d, e, f, g.h,i
Key: upper case letter = very suitable; lower case letter = suitable. A = hand lay-up; B = spray lay-up, C = injection/vacuum forming; D = centrifugal casting; E = filament winding; F = continuous impregnation; G = wet press moulding; H = hot press moulding (SMC/BMC); I = hot press moulding (granular moulding compound).
12.8 Curing Agents for Epoxy Systems
Dicyandiamide, organic acid anhydrides and adipic dihydrazine are widely used as latent curing agents for epoxies. Latent epoxy systems obtained from these hardeners have fairly good storage stability but must be heated at higher temperatures for a long time to establish the curing reaction. To improve curing
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conditions, accelerators such as aromatic tertiary amines or imidazole derivatives are used, but these tend to reduce the latency, resulting in very short pot life. Liquid aliphatic polyamines and their adducts are convenient to handle and give good physical properties for the cured resin, including excellent resistance to chemicals and solvents. Mix ratios are critical for optimum performance. Aliphatic amides offer fast curing at elevated temperatures, but their short pot life and high exotherm in thick sections or large masses can lead to thermal decomposition. Good long-term retention of properties is possible at temperatures up to 100°C. Short-term exposure to higher temperatures can be tolerated. Aliphatic amines will blush under very humid conditions. Adducted aliphatic polyamines offer the advantages of lower vapour pressure, reduced blush tendency, and less-critical mix ratios. Cycloaliphatic amines give the cured resin improved thermal resistance and toughness (compared with aliphatic polyamines). Glass transition temperatures approach those of aromatic amines and percentage elongation can be doubled. Because they are less reactive than aliphatic polyamines, they can be used to obtain longer pot life and give the ability to cast larger masses. Aromatic amines are solids at room temperature and are routinely melted at elevated temperatures and blended with warmed resin. Eutectic mixtures of metaphenylene and methylene dianiline exhibit a depressed melting point, producing an aromatic hardener that remains liquid over short periods of time. Pot life is considerably longer that that of aliphatic polyamines. Cure at elevated temperature is needed to develop optimum properties, which are maintained at up to 150°C. Aromatic amines have better chemical and thermal resistance than aliphatic polyamines. Polyamides are the most commonly used polyamines. They are the condensation products of dimerized fatty acids and aliphatic amines such as diethylene triamine. A range of molecular weights is available, making these curing agents versatile in a variety of applications. They react with epoxide groups through the unreacted amine functional groups in the polyamide backbone. Due to their relatively high molecular weight, the ratio of polyamide to epoxy is more 'forgiving' (can vary more) than with lower molecular weight polyamines. Polyamides also offer the advantage of curing without blushing, and improved adhesion - but they are much darker in colour. The various molecular weight polyamides show different degrees of compatibility with epoxies. To ensure optimum properties the polyamide/epoxy mixture must be allowed to react partially before being used. This partial reaction assures compatibility and is known as the 'induction' period. Because polyamides have a long pot life, the induction time does not significantly shorten the usable time of the system. Polyamide-cured epoxies lose structural strength rapidly with increasing temperature, limiting their use to applications that will not be subjected to temperatures above 65°C. Amidoamines are derivatives of monobasic carboxylic acid (such as ricinoleic acid) and an aliphatic polyamine. Like the polyamides, amidoamines can be used
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over a range of additive levels to enhance a specific property. The reactivity of amidoamines with epoxies is similar to that of polyamides, but the former offer several advantages over both polyamides and aliphatic amines: lower viscosity and colour than polyamides and more convenient mix ratios, increased flexibility, and better moisture resistance than aliphatic amines. Dicyandiamide (Dicy) is a solid curing agent which, ball-milled into liquid epoxy resins, provides one-package stability for up to six months at ambient temperature. The cure occurs when heated to 150°C; a tertiary amide accelerator is needed for rapid cures. *Dicy' offers the advantage of being latent (it reacts with epoxy on heating and stops reacting when the heat is removed). This partially cured (or 'B-stage') state is ideal for pre-preg applications. Resin systems made from dicyandiamide-cured epoxy have high rigidity and good chemical resistance. Derivatives, such as biguanides, condensation products with aldehydes, and metal complexes can also be used as curing agents for epoxies. Typically, dicyandiamide is used at levels of 5-7 parts per 100 parts liquid epoxy, and at 3-4 parts per 100 solid epoxy resin. It can be used for onecomponent formulations with long shelf life. The moderately high curing temperature can be reduced by adding accelerators such as amines, imidazoles, or urea derivatives. Applications include prepregs and composites, printed circuit boards, structural adhesives, powder coatings, and lacquers and varnishes. Catalytic curing agents are a group of compounds that promote epoxy/epoxy reactions without being consumed in the process. Stable one-package systems can be developed with many catalytic curing agents, such as the boron trifiuoride complexes. Tertiary amines and amine salts have pot lives generally ranging from 2 to 24 hours. The latent catalysts are activated by heat and cause a dissociation of the active catalysts from the blocking group. The amount of catalyst used may vary from 2 to 10 parts per 100 parts resin. To determine the best catalyst/resin ratio, several different catalyst levels should be evaluated for the one giving the best properties. Several common catalytic curing agents are: benzyldimethylamide (BDMA), boron trifiuoride mono-ethylamine (BF3.MEA), and 2-methylimidazole (2-MI). Anhydrides, both liquid and solid, are used widely for curing epoxy resins. The reactivity of some is slow and an accelerator (usually a tertiary amine) is often used at 0.5-3.0% to speed gel time and cure. The optimum amount is usually critical, depending on the anhydride and resin, and the cure schedule. Amounts above or below the correct level will reduce the high-temperature performance. The optimum balance should be established by experiment. Eutectic mixtures to depress the melting points may be prepared. Compared with aliphatic amine cures, the pot life of anhydride cures is usually long and exotherm is low. Elevated-temperature cures at up to 200°C are necessary and long post-cures are required to develop ultimate properties. Electrical and physical strength properties are good over a wide temperature range. Compared with amine-cured systems, anhydride cures offer better chemical resistance to aqueous acids, and less chemical resistance to some reagents. Melamine/formaldehydes cross-link with epoxy resins to give low-colour coatings with good physical properties, chemical resistance, and no effect on
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taste. They will react with epoxide or secondary hydroxyl groups, with varying degrees of reactivity and compatibility. Urea/formaldehydes react in a similar manner, giving exceptionally low colour with good colour retention, hardness, and solvent resistance. Phenol/formaldehyde resole resins cure with epoxies through the secondary hydroxyl groups in the epoxy backbone. Elevated temperatures of above 150°C are necessary to promote cure and use of an acid accelerator is desirable. The resulting systems give hard chemical-resistant coatings, with a wide temperature range. Epoxy/phenolic ratios normally range from 80/20 to 6 5 / 3 5 : increasing the phenolic level improves chemical and solvent resistance, but at the sacrifice of some adhesion and flexibility. Phenol/formaldehyde novolac resins react with epoxy groups at elevated temperatures to give highly cross-hnked systems, with a high service temperature >150°C and excellent chemical resistance. The typical epoxy/ novolac ratio is 0.9 to stoichiometric: a tertiary amine accelerator is necessary for complete cure. Isophorone diamine (IPDA) hardeners are used in epoxy resin formulations mainly for preservation of structures and for composite materials with strong mechanical properties and high resistance to corrosion. The derivative isophorone di-isocyanate (IPDI) is also finding increasing use as a material for light-fast polyurethane coatings.
12.9 Cure Promoters
Cure promoters include metal compounds, for optimal cure hot press moulding; acetylacetone, with ketone peroxides and cobalt accelerator for a short geltime, giving a fast cure at room temperature and at elevated temperature; and tertiary dodecyl mercaptane, for a gradual cure and moderate peak exotherm, in filament winding.
12.10 UV Cure Initiators
UV cure initiators include aromatic ketone, used in printing ink and paper coating; benzoine ether, a general UV cure initiator for FRP laminates, putties and lacquers, particularly effective with fillers; and a mixture of ketones, used with an amine accelerator for UV-curing FRP laminates.
12.11 New Developments
Designed for epoxy resin systems, Anquamine 401 and Ancamide 2424 (by Air Products) are a modified aliphatic curing agent at 70% solids in water for waterborne two-component epoxy coatings; and a modified polyamide curing agent for liquid epoxy resins in two-component structural adhesives.
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Table 12.5 Curing agents for epoxy resins Type
Advantage
Disadvantage
Typical applications
Polysulphides
Moisture insensitive; quick set time; flexible
Odour; poor performance at elevated temperature
Adhesives, sealants
Aliphatic amines
Convenient; cures at room temperature; low viscosity; low formulation cost
Critical mix ratios; strong skin irritant; high vapour pressure; blushing
Civil engineering, adhesives, grouts, casting, electrical encapsulation
Polyamides
Convenient; cures at room temperature; low toxicity; flexibility/ resilience; good toughness
Higher formulation cost; high viscosity; low heat resistance; low vapour pressure
Civil engineering, adhesives, grouts, castings, coatings
Amidoamines
Reduced volatility; convenient mix ratios; good toughness
Construction adhesives, Poor performance at elevated temperature; concrete bonding, some incompatibility trowelling compounds with epoxy resin
Aromatic amines
Moderate heat resistance; good chemical resistance
Solid at room temperature; long cure schedules at elevated temperature
Filament-wound pipe, electrical encapsulation, adhesives
Dicyandiamide
Latent cure; good properties at elevated temperature; good electrical properties
Long cure at elevated temperature; insoluble in resin
Powder coatings, electrical laminates, one-component adhesives
Catalytic
Very long pot life; high heat resistance
Long cure schedules at elevated temperature; poor resistance to moisture
Adhesives, electrical encapsulation, powder coatings, electrical laminates
Anhydrides
Good heat resistance; Long cure schedules good chemical resistance at elevated temperature; critical mix ratios
Filament-wound pipe, electrical encapsulation, adhesives
Melamine/formaldehyde Good hardness/ flexibility; one-pack stability; solvent-free systems
Cures at elevated temperature
Waterborne coatings, primers and topcoats
Urea/formaldehyde
Good film colour; one-pack stability; good intercoat adhesion
Cures at elevated temperature
Fast-bake enamels, primers and topcoats
Phenol/formaldehyde
Solid; poor weather Good properties at reistance elevated temperature; good chemical resistance; good hardness/flexibility
Powder coatings, moulding compounds
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For cationically cured resin systems, new photoinitiators, CD-1010 triaryl sulphonium hexafluoroantimonate and CD-1011 triarl sulphonium hexafluorophosphate, have been developed by Sartomer. Cure enhancers for UV/EB and peroxide-cure systems are low-volatiUty Uquid monomer SR-502 ethoxylated trimethylolpropane triacylate, curing rapidly in systems to increase flexibility, weather resistance, chemical resistance, shrinkage, abrasion resistance, and impact strength, for coatings, PVC flooring, and photopolymers; and CD-501 propoxylated trimethylolpropane triacrylate, for low shrinkage in acrylics, adhesives, coatings, electronics, and photopolymers.
12.12 Thermoplastics Cross-linking
Production of high-performance thermoplastics cable requires cross-Unking, usually by one of three methods: peroxide, silane (Monosil or Sioplas), and electron beam, each requiring a different compound to achieve the right properties. Peroxide cross-linking employs the thermal degradation of a peroxide to form free radicals. These then abstract a hydrogen atom from the polymer, producing a free radical site. Two radicals then combine to produce a chemical bond. The peroxide is usually present in the polymer as supplied and is not added as a separate material. The thermal reaction usually takes place in a hightemperature continuous vulcanization (CV) tube, immediately after the compound has left the extruder die. The residence time of the cable in the high-pressure CV tube determines the extent of the reaction and so dictates the speed of the extrusion line. The temperature in the extruder is also critical, as too high a level will initiate the decomposition of the peroxide and the reaction will start to occur in the extruder. Silane cross-linking - specifically the *one-shot' system - employs a threecomponent mix (of peroxide, silane, and tin catalyst, either in the form of liquid of dry masterbatch) that is added separately to the compound during extrusion. The reaction is in two stages, the temperature of extrusion being used to decompose the peroxide in order to react the silane molecule onto the polymer backbone. This material is then extruded, forming the cable, and the silane units are then hydrolysed together in a secondary stage off-line from extrusion, using moisture and the tin catalyst. Cross-linking can be achieved either by placing the cable drum in a water tank, or in a steam room, or by allowing atmospheric moisture to complete the reaction. Since the cross-linking stage is separate from extrusion, the line speed is determined by the output of the extruder, not the rate of the cross-linking reaction. A dry silane masterbatch for cable extrusion applications has been developed by the Hanna group, Wilson Color. It is claimed to reduce costs in formulation of in-house grafted compounds, providing a route to cost-effective, one-step crosslinked polyethylene cable extrusion. A range of grades is available, to give a broad application 'fit'. Because the active cross-linking agent is in a dry solid
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form, the masterbatch eliminates the need for Uquid injection and can be used in all standard extruders. Other advantages include a higher set-up temperature, which gives higher thermal stability during grafting and extrusion and reduces the risk of plate-out on the extruder screw, producing higher grafting efficiency. The masterbatch maintains the required level of anti-oxidants and metal stabilizer in the final compound, forming a completely homogeneous mix. Special stabilizers prevent premature polymerization. Another technological advance has been the development of cross-linking methods, giving the polymer improved physical properties, better resistance to chemicals, and retention of shape at temperatures significantly above the melting point of the polymer itself, so prolonging its life in the event of a fire. Electron beam curing is similar to peroxide cross-linking, except that no peroxide is necessary. The cable is passed in front of a radiation source that generates radicals on the polymer backbone by removing hydrogen atoms, which then react together to produce a chemical bonding between the polymer chains. The eventual density of cross-linking is determined by the number of passes through the radiation source, and its intensity, so controlling the rate of production. Manufacturers such as BICC General Compounds have developed ranges of halogen-free, low-smoke and low-fume compounds, specifically for manufacture Table 12.6 General specifications for BS7211 Specification requirements Mechanical properties (BS EN 60811) Minimum tensile strength Minimum elongation at break Heat-aged properties (BS EN 60811) Tensile strength: maximum variation Elongation at break: maximum variation High-temperature properties (BS EN 60811) Pressure test at 100°C: maximum penetration Hot set test at 200°C 3°C; mechanical stress, 0.20 N mm~^: maximum elongation Maximum permanent elongation
lO.OMPa 12 5% Temperature:! 3 5°C2°C; duration: 2 days 30% 30% 50% 100% 25%
Low-temperature properties (BS EN 60811) Cold bend at-15°C Cold impact at-15°C Cold elongation at -15°C
No cracks No cracks 30% minimum
Fire test properties Flame propagation, BS 4066 Part 1 Smoke emission, lEC 61034 Halogen acid gas emission, BS 642 5 Part 1 Acid gas emission, BS 642 5 Part 2 Conductivity of effluent gases
50 mm minimum 60% maximum 0.5% maximum 4.3 pH minimum 10 |iS mm~^ maximum
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by any of these three routes. For peroxide cross-Unking, the compound has been selected to maximize the speed of the line by providing maximum scorch safety time during extrusion, while giving maximum residence time in the CV tube. The version for silane processing has been formulated to minimize silane doses and avoid side reactions with the curing system, while the compound for electron beam curing contains special promoters to maximize cross-link density.
Table 12.7 Advantages and disadvantages of available cross-linking methods Peroxide
Monosil
Electron beam
Set-up costs
High: needs expensive CV tube and heating equipment
Low: can use conventional PVC extrusion line
Very high: needs expensive radiation s ource and appropriate safety equipment
Manufacturing speeds
Limited by residence time in CV tube, which determines line speed
Normal extrusion limits: i.e. head pressure and rpm
Limited by exposure time to radiation source, which dictates line speed
Health and safety
Compound contains peroxide
Silane requires special handling and storage
Special controls and procedures needed for radiation source
Other factors
Start-up scrap through the CV line
Requires curing off-line. Can use either ambient cure or water tank/sauna
Short cross-linking time
Source: BICC General Compounds Division
12.13 Commercial Trends
No market figures are available for curing agents, but their size and growth are closely related to the use of thermosetting resins and polyurethanes. The overall technical trend is towards systems that are more rapid and safe in use. A specific area of growth is radiation curing, in which the resin system is cured by exposure to a radiation source. This technique is particularly effective for products that can be cured continuously, rather than in batches. Demand for radiation-cured products is increasing at more than 10% a year in the USA, and will reach some 90 000 tonnes by the year 2 0 0 3 . Prices will remain at well above the levels of conventionally cured alternatives, such as coatings, inks, and adhesives, so that the total value of the market will increase at nearly the same rate, to US$1.3 billion. Freedonia concludes that coatings will remain the largest segment, at 5 1 % of total volume, with the advantages of coating onto heat-sensitive materials, overall better finished product quality and near-instantaneous cure. Flooring and furniture will be the main uses, with packaging, printing, and electrical and electronics providing other large markets.
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Table 12.8 Use of radiation-cured products in the USA, 1 9 8 9 - 2 0 0 3 (tonnes)
Coatings Inks Adhesives Other products Total demand Value of production (US$ million) Source: Freedonia
1989
1998
2003
% change (1989- -1998)
% change (1998-2003)
9980 6805 455 1360 18 600 275
28 575 19 050 1815 5900 55 340 800
46 270 30 390 2720 11 340 90 720 1270
12.4 12.1 14.8 19.8 13.0 12.6
10.1 9.8 10.3 13.4 10.4 9.7
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CHAPTER 13 Modifying Processing Characteristics: Couplings Compatibilizing Agents Coupling agents may have a significant influence on mechanical properties, including impact strength, by acting as molecular 'bridges' chemically formed at the interface between two substrates, such as an inorganic fibre or filler and an organic polymer matrix, to improve the bond between the two. The Coupling Agent Index (Intertech) identifies six main types: • • • • • •
Organosilanes Organozircoaluminates Chartwell adhesion promoters Functionalized organic polymers Organotitanates Organozirconates
Organosilanes have long been used to improve the chemical bond between a variety of thermosetting resins and glass fibre and other silaceous surfaces, but they are essentially non-functional with organic-based fibres, such as graphite or aramid. Organometallic coupling agents, based on titanium or zirconium, offer a wider compatibility, in glass fibre-reinforced composites with epoxy and polyester and in aramid- and carbon-reinforced composites with epoxy, polyurethane, and vinyl ester. Significant improvements in wetting out and bonding and in the chemical resistance of thermosetting systems have been gained by, respectively, use of 0.2% aromatic aminozirconate with epoxy resin and an aromatic aminotitanate with a vinyl ester, using silane-sized glass in both cases. Improved process rheology has also been shown in thermoplastic matrices such as reinforced polyphenylene sulphide and polycarbonate. In thermoplastics, the organometallics appear mainly to provide a catalytic support bed for in situ re-polymerization of the polymer matrix, which reflects itself in improved processing. A test on a 40% polycarbonate/glass compound showed improvements in mechanical properties, together with significant improvements in productivity. Titanium-derived coupling agents are unique in that, by reacting with free protons at the inorganic interface, organic monomolecular layers are formed on
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the inorganic surface. Titanate-treated inorganics tend to be hydrophobic, organophilic, and organo-functional. When incorporated into polymer systems they can improve impact strength, promote adhesion, catalyse, and improve dispersion and rheology. They do not create embrittlement but can improve mechanical properties and make inorganic loadings of about 50% desirable, preventing phase separation and inhibiting corrosion. The use of organotitanate and/or organozirconate coupling agents, either independently or optionally together with other surface-reactive materials, such as organosilanes, also significantly improves the properties and processability of fibre-reinforced polymers, and their resistance to chemical attack and corrosion. Zirconate coupling agents provide a functional equivalent alternative to the silanes and titanates, correcting some of their disadvantages. They do not interact with hindered amines (HALS, used as light stabilizers and/or antioxidants) and, in unfilled plastics, they often improve ultraviolet stability, compared with titanates. Recent manufacturing improvement has reduced the original high cost. Table 13.1 At a glance: coupling, compatibilizing agents Function
To form chemical linkages between molecules that are normally incompatible
Properties affected
Mechanical strength, processability
Materials/characteristics
Organosilanes, adhesion promoters, functionalized organic polymers, organotitanates, zirconates
Disadvantages
Complex chemistry, only partly understood
New developments
Could be significant in creating new polymer systems and making useful polymers from recovered waste
13.1 New Developments
Two additions to its range of polymer modifiers have been introduced by Uniroyal Chemical, in its Polybond chemically modified polyolefins and Royaltuf modified ethylene/propylene terpolymer (EPDM) elastomers. Polybond 3109 is for polyolefins to improve the bonding between the non-polar resins and fillers and reinforcements such as glass, wood flour, and non-halogenated flame retardants. Produced from linear low-density polyethylene, functionalized with 1% grafted maleic anhydride, it has a melt flow index of 30 (six times higher than Polybond 3009), giving easier mixing and better performance. Royaltuf 498 is designed for nylon 6 resins, giving better impact resistance at low temperature. It is produced from EPDM, functionalized with 1% maleic, and has a Mooney viscosity of 30. Applications include housings for hand-held power tools and sporting goods.
CHAPTER 14 Modifying Processing Characteristics: Plasticizers
Table 14.1 At a glance: plasticizers Function
Added to make a compound more flexible, easier to process; mainly used with PVC; also for cellulosics.
Properties affected
Flexibility, viscosity.
Materials
Monomeric: esters of phthalates, adipates, benzoates, mellitates. Polymerizable esters: di-phthalate ester.
Disadvantages
Migration; strict compliance with food contact regulations.
New developments
Greater efficiency at lower addition levels, easier mixing; replacement of potentially hazardous types; reduction of leaching/migration.
14.1 The Function of Plasticizers
Many thermoplastics require an additive to plasticize them, either to render the basic material processable, or to extend the range of properties, either to render it repeatedly flexible, or to improve flexiblity at low temperature (sub-zero and well below). Plasticizers are low molecular or oligometric additives that are compatible with rigid thermoplastic polymers, rendering them semi-rigid or leathery/rubbery in behaviour. They can be either non-polymeric materials or polymer impact modifiers. Some forms of copolymerization can also produce a degree of internal plasticizing. Certain plasticizers can also perform other functions, assisting in viscosity control, in the dispersion of particulate additives such as fillers and pigments, and general lubrication of the compound (including mould release). Plasticizers are used mainly (about 80%) in PVC compounds, both flexible and rigid, which is unprocessable without a plasticizer. Over the years, certain of them have been withdrawn on the grounds of potential toxicity. Recently, phthalates have come under intense pressure due to fears of carcinogenicity and oestrogen interference.
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14.2 Main Types of Plasticizers The main types of plasticizers are summarized below. Table 14.2 Main types of plasticizers Phthalic acid esters Diethylhexyl phthalate (usually called dioctyl phthalate - DOP)
Most widely used: good gelling, relatively non-volatile under heat, satisfactory electrical properties and highly elastic compounds with reasonable cold strength
Diisotridecyl phthalate (DITDP)
Long-term heat resistance up to 105°C
Phthalates of straight-chain CyHn alcohols
Good non-volatile behaviour and good low-temperature properties
Esters ofadipic and sebacic acid Diisodecyl adipate (DIDA)
Less volatile than dioctyl ester (DOA, DOS)
Citric acid esters
Physiologically harmless: used in food industry
Polyglycol fatty acid esters
Good low-temperature resistance (to -30°C) and long-term heat resistance (100°C): addition of 0.05% bisphenol A prevents splitting of oxoalcohol ester plasticizers under heat stress
Tricresyl phosphate (TCP, TCP)
Outstanding heat resistance, good electrical properties, weather resistance, flameproof; not resistant to low temperatures; should not be used for products in contact with the skin. Other phosphates have lower resistance to heat
Parafflnic sulphonic acid phenyl ester
Midway between DOP and TCP in plasticizing properties: widely used in Germany
Oligomeric/polymeric plasticizers
Suitable for pastes (oligomeric) and extrusion/calendering compounds (polymeric); non-migratory, scarcely volatile, low dependency on temperature; some types resist extraction by aliphatic hydrocarbons, mineral oils or fats; some difficult to incorporate/compatible with PVC only in
PVC/EVA graft polymer
Soft films without plasticizer
Epoxidized soyabean oil, epoxidized esters
Combine functions of plasticizing and stabilizing
Source: Manufacturers' literature and International Plastics Handbook
14.2.1
Phthalates
Phthalates (phthalic acid esters) are among the most widely studied and best understood of all compounds. They are very efficient and are among the most important, and are certainly the most controversial, on grounds of alleged health hazard. This particularly concerns phthalates used in critical applications
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171
such as infant care and teething products, which are likely to be placed in the mouths of babies. They combine superior performance and cost effectiveness to create vinyl medical products that have led to improved and affordable patient care. Like many other chemicals, both synthetic and natural, phthalate plasticizers may be absorbed in small quantities by the fluids with which they come into contact, but this is a known occurrence and the safety of products is regularly reviewed and stringently monitored by both industry and regulatory authorities. The industry argues, however, that it has some 30 years of experience in using phthalates for another critical application, medical products. Phthalates account for 92% of all plasticizers and European production is running at about a million tonnes a year and growing at 3.7% a year. The breakdown of use of different types is: diethyl hexyl phthalate (DEHP), 51%; diisodecyl phthalate (DIDP), 2 1 % ; diisononyl phthalate (DINP), 11%; and others, 17%. As can be seen, the most widely used phthalate by far is di-2-ethylhexyl phthalate (DEHP), sometimes known as di-octyl phthalate (DOP). It gives good gelling, is relatively non-volatile under heat, and offers satisfactory electrical properties and highly elastic compounds with reasonable cold strength. It is also the preferred phthalate for medical devices because of its properties, which include maintaining flexibility at low temperatures combined with a resistance to high-temperature sterilization. Due to DEHP's unique properties, many different PVC formulations can be developed, ranging from glassy compositions to soft, highly flexible materials. It also enables the construction of transparent PVC products, a factor important in many medical applications. Its advantages in medical tubing include a high resistance to kinking to ensure that critical fluids reach a patient in prescribed doses. Phthalic acid esters of high-molecular-weight alcohols are used as special plasticizers for PVC, in liquid or semi-solid form. Diisotridecyl phthalate (DITDP) in liquid form is used for heat-resistant cables, offering long-term heat resistance up to 105°C. Dimethylcyclohexyl phthalate (liquid) is a special plasticizer for underbody automobile coating. Phthalates of straight-chain C7H11 alcohols offer good non-volatile behaviour and good low-temperature properties. 74.2.2 Sebacates and adipates
These materials provide good low-temperature plasticizers for PVC, in liquid form, with fairly general food-contact approval. Dibutyl sebacate is a highly efficient primary plasticizer for low-temperature applications, and is used in films and containers for packaging. 74.2.3 Fatty acid esters
Esters of fatty acids and monocarboxylic acids can be used as viscosity depressants for PVC pastes and also as secondary plasticizers for plasticized PVC compounds. They are in liquid form. Advice should be sought on food-contact
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approval. Stearic acid esters are used as plasticizers and processing agents for various plastics and also as lubricants for polystyrene. They are semi-solid and have general food-contact approval. 74.2.4 Oligomeric/polymeric
plasticizers
Oligomeric and polymeric plasticizers (usually polyesters, based on adipic acid) extend the life of PVC end-products considerably. They reduce migration, extraction, and volatility. They are suitable for pastes (oligomeric) and extrusion/calendering compounds (polymeric). They are non-migratory, scarcely volatile, and have low dependency on temperature. Some types resist extraction by aliphatic hydrocarbons, mineral oils, or fats; some are difficult to incorporate or are compatible with PVC only in mixes. The molecular weight has a significant influence on performance but other factors also determine characteristics and performance. Typical applications include coated fabrics, protective clothing, electrical tapes, conveyor belting, food wrapping, laminated films, adhesive-coated films, heat-resistant cables, oil-resistant cables, oil and petrol hose, refrigerator gaskets, and roofing membranes. In PVC, monomeric plasticizers offer generally good low-temperature performance. They can be derived from a number of sources, such as phthalic anhydride, trimellite anhydride, benzoic acid, or adipic acid with monofunctional alcohols. They are oily limpid liquids with boiling points (at 760 mm Hg) higher than 300°C. They are highly compatible with PVC, with good gelling power and relatively low volatility. They can easily be incorporated into products giving high plasticity, low-temperature resistance, and glossy surface. Phthalic plasticizers are mainly used for standard applications with PVC. Trimellitates may be considered as special plasticizers, as they show less volatility and lower migration. Trimellitic acid ester (in liquid form) is a highly heat-resistant plasticizer, pre-stabilized for cable applications. Adipates are generally used in mixtures with other plasticizers, to increase plasticization and improve low-temperature properties. Benzoates are high solvating speciality plasticizers, used either alone or as primary components, but with interest now centred on development of new blends with specific characteristics. Monomeric plasticizers are also used to plasticize cellulose acetate. Some polymerizable esters can be used as a copolymerizable internal plasticizer in technical applications. The best known of the group is diallyl phthalate (DAP), which is used to replace styrene, divinyl benzene, or methyl methacrylate in unsaturated polyester resins. It has a very low vapour pressure (300°C boiling point), leading to significant reduction in loss through evaporation. It considerably improves properties such as hardness, chemical resistance, hydrolysis resistance, electrical properties, and product Ufe. It is particularly used in electrical applications, can be employed (after suitable preparation) in cold-cure systems, and shows high affinity to glass fibre. DAP can also be used as a reactive plasticizer with PVC resins.
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74.2.5 Epoxies
Epoxy plasticizers are used as stabilizing plasticizers offering properties of migration resistance in PVC compounds, alkyd resins, and chlorinated paraffins, and as pigment dispersing agents in plasticized PVC. They are recommended especially for food-contact and medical applications, giving low dosage levels, low odour, and good resistance to extrusion with good colour control. Specific grades are also good low-temperature plasticizers and effective co-stabilizers. Alkyl epoxy stearate plasticizers are used as low-viscosity stabilizers, especially in PVC pastes, with some grades providing good low-temperature properties. They are in liquid form. Soya bean versions have widespread approval for food contact. Advice should be sought for other types.
14.3 Extenders and Secondary Plasticizers
Extenders or secondary plasticizers are relatively cheap materials that gel with PVC without themselves providing adequate plasticizing. Some fatty acid esters and hydrocarbon products can improve the flow properties of pastes. Chlorinated paraffins are flame retardant. Monomeric glycol methacrylate reduces viscosity of pastes, but polymerizes in the presence of an added catalyst on gelation to the end product, and increases its hardness.
14.4 Health and Safety of Plasticizers
Concern about the effect of certain plasticizers on human health, particularly the carcinogenic and oestrogenic effects, has been expressed from some quarters and there has been extensive study and testing to establish the facts. The products particularly under scrutiny have been PVC compounds for medical products and baby- and infant-care products, especially those designed to be put in the mouth. DEHP, which is particularly suitable for medical products, has been most under examination. DEHP has for several years been recognized as non-carcinogenic (or unlikely to be carcinogenic) by most international authorities, including the World Health Organization, the European Commission, and Health Canada. Until now, however, the world's leading authority, the International Agency for Research on Cancer (lARC) classified it as 'possibly carcinogenic to humans', based on early studies on rodents. The lARC has concluded that more extensive recent research has shown that effects observed in rats and mice are not relevant to humans and the plasticizer is 'not classifiable as to carcinogenicity to humans'. There is a safety margin of about 14 000 in the estimated current intake of DEHP plasticizer, according to studies (by BASF). The plasticizer is considered detrimental to human reproductive organs after oral administration, at a level of 69 mg kg~^ body weight day~^. Several studies have indicated an average daily
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lifetime exposure of 2.3-2.8 jig kg~^ day~^ in Europe and 4 jig kg~^ day~^ in the USA. Research has recently turned towards oestrogenic effects, and has proved a controversial subject. Work suggests that the most commonly used phthalates do not produce any effect on human reproductive organs. A European Commission decision in 1990 confirmed that DEHP should not be classified or labelled as a carcinogenic or an irritant substance. Another study examined the possible health risk to humans from DEHP, particularly via its use in medical equipment, and concluded that a cancer risk is unlikely, even in haemodialysis patients, who are most exposed to the chemical. One of the world's leading manufacturers of medical devices, Baxter (which had been widely reported to be abandoning the use of PVC), estimates that acute and chronic exposure to DEHPplasticized medical products totals 5-7 billion and 1-2 billion patient days, respectively. DEHP is currently the plasticizer recommended in the European Pharmacopoeia for medical devices, and PVC containers are the only type listed for use for blood, blood components, and for aqueous solutions for intravenous infusion. Other materials can only be used subject to approval in each case by the national authority responsible for licensing them. An EU risk assessment, published at the end of 2000, concluded that no environmental classification was necessary for DINP (diisononyl phthalate) and DIDP (diisodecyl phthalate). This means that there are no product labelling requirements to indicate an environmental hazard. More significant is the finding that no further information or risk reduction measures are needed beyond those already applied. The conclusion is valid throughout the EU and represents an internationally accepted view.
14.5 Reducing the Level of Plasticizers
Although there needs to be constant vigilance regarding the intrinsic health and safety of plasticizers, leading to constant research to improve formulations, there has also been parallel work on the reduction in the use of these materials. Plasticizers enter the environment mainly by evaporation during processing of the plastics compound - estimated to range from 0.03% in injection moulding to up to 2% in coating processes. These levels are continually being reduced by installation of incineration, scrubbing, and filtration systems in processing plants. In PVC wall and floor covering, the use of plasticizer can result in small quantities of plasticizer vapour being present in room air: at 25°C, the maximum level of DOP which can be present in 1 m^ of air is approximately 0.01 mg and in recent emission chamber measurements, 1 m^ of PVC flooring tested for 96 hours showed no detectable level of plasticizer emission (at 4 parts per billion limit). Another line of recent development work has been to adjust the particle distribution of the resin system, to improve flow and use of plasticizer. Researchers at Hydro Polymers have confirmed that, in plastisols, it is possible to
Modifying Processing Characteristics: Plasticizers
17 S
reduce the consumption of plasticizers and diluents by using resin systems with perfectly spherical particles with an optimal particle size distribution. The level of plasticizer was reduced from 50 to 30 phr without changing the flow behaviour of the plastisol significantly. There was no sedimentation, and extremely thin films could be produced. An increased level of 15 jim monodisperse particle resin blended into a fine particle resin (0.2-2 |im) increased the amount of free plasticizer in the system.
14.6 Recent Developments
Benzoate esters have been used as plasticizers in a number of PVC formulations for many years but, although they had been known to exhibit excellent stain resistance, UV resistance, and gelation properties (much valued, for example, in the PVC resilient flooring sector), their use has to some extent been limited by relatively high viscosity. New blending technology developed by Velsicol Chemical promises to bring these plasticizers back to the fore, with enhanced processing and properties and also better environmental performance. In PVC compounds, they act as high solvators but, unlike benzoate esters of older technology, they are low in volatile organic compounds (VOCs). Compared with other plasticizers they are often more efficient (up to 20% more efficient than DINP, it is claimed) and it may be necessary to reformulate some plastisols. They are also claimed to have Very desirable' environmental, health, and safety profiles. A halogenated flame-retardant plasticizer is produced by Uniplex, containing bromine and chlorine. It improves low-temperature brittleness and provides lower smoke than conventional brominated phthalate diesters, for use primarily in wire and cable applications of flexible PVC, EPDM, and thermoplastic olefins.
14.7 Commercial Trends
World capacity for plasticizers stands at present at some 4.5 million tonnes, due to growth in the higher weight molecular plasticizers DINP and DIDP at the expense of the commodity plasticizers. An 8% a year increase in demand is expected in these materials, compared with a 5% a year increase in commodity types. The average global rate of increase across the industry is predicted at 3.5% a year, producing a world market of some 6 million tonnes in 2010, led by Asia, Eastern Europe, and Latin America. The industry faces heavy overcapacity, however, as Asia becomes selfsufficient and export potential from European producers becomes more limited. A radical restructuring is expected.
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CHAPTER 15 Modifying Processing Characteristics: Blowing Agents Table 15.1 At a glance: blowing agents Function
Creating a cellular structure during processing, usually by formation of an inert gas at the processing temperature; used for foams and expanded materials, injection moulded structural foam.
Properties affected
Cellular structure, stiffness/rigidity, lightness in weight; reduced shrinkage (especially at thick sections); reduction in moulding pressure.
Materials/characteristics
Physical blowing agents; low-boil hydrocarbons. Chemical blowing agents: fluorocarbons (for polyurethane and PS foams); sodium bicarbonate/citric acid or azo compounds, etc., for moulded structural foams.
Disadvantages
Structural foam blowing agents may produce 'swirl' effect on surface of mouldings, requiring treatment before painting.
New developments
Replacement of CFC blowing agents (in polyurethane and polystyrene foams).
15.1 The Function of Blowing Agents
Blowing agents are added to (mainly thermoplastic) compounds to produce foamed materials which have the advantages of lightness and thermal insulation, and may sometimes also offer better stiffness and rigidity. There is also growing interest in direct injection of an inert gas during the injection moulding sequence, to form a core in a solid moulding, pressing the melt against the mould surface, preventing visible shrinkage, and allowing thick or hollow sections to be moulded without the usual penalty of sink marks. An expanded material has a cellular structure which, depending on the material, can be produced by physically introducing bubbles (usually of air or an inert gas), or by producing them chemically by means of blowing agents which decompose during the process (usually by heat) to release a suitable gas. Chemical blowing agents are used to produce polyurethane foams and PU foam mouldings (with integral skins) and to injection mould structural foam versions
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of thermoplastics. The cells may or may not be interconnected (which can additionally be a property of the additives, or of subsequent physical processing of the expanded material to rupture the cell walls). Polyurethane foam is by far the largest user of blowing agents and has traditionally used chlorofluorocarbons (CFCs). Due to fears that these may harm the ozone layer, according to the Montreal Protocol the use of CFC gases for production of both polyurethane foam and expanded polystyrene has been virtually phased out, and a number of alternatives have been developed. To improve control of the formation of the foam during the process, and to achieve a uniform cell structure, other additives (called nucleating agents) are often used. It is also possible to extrude some thermoplastics in an expanded form by means of direct gassing, together with nucleating agents. The main gases used as blowing agents are listed below. Table 1 S.2 Blowing gases for plastics^ Name/type Alkane group n-Butane Isobutane M-Pentane Isopentane CFC group Rll R12 R114
Formula C4Hi() QHio C5H12 CsHi2
Molecular weight
Boiling point (°C)
58.1 58.1 72.2 72.2
-0.5 -11.7 36.0 28.0
CFCI3 CF2CI2 CF2CI-CF2CI
137.4 120.9 170.9
23.8 -29.8 3.6
H'CFC/HFAgroup R22 R123 R134A R141B R142B
CHF2CI CHCI2-CF3 CH2F-CF3 CCI2F2-CH5 CCIF2-CH5
88.5 152.9 102.0 116.0 100.5
-40.8 27.8 -26.5 31.7 -9.8
Other gases Argon Carbon dioxide Nitrogen
Ar CO2 N2
39.9 44.0 28.0
-163.8 -78.4 -195.8
'*Abbreviations: CFC, chlorofluorocarbon; HFA, hydrofluoroalkane; H-CFC, hydrochlorofluorocarbon. Source: Boehringer Ingelheim
15.2 Physical Blowing Agents
These can be low-boiling organic solvents (preferably hydrocarbons) that cause foaming by their vapour pressure during the conditions of processing, or in the form of compressed gas or volatile liquids that undergo a phase change at elevated temperature. These include (with their boiling points): pentane and heptane (30-100°C), chlorinated hydrocarbons such as methyl chloride (24°C),
Modifying Processing Characteristics: Blowing Agents
179
methylene chloride (40°C), trichlorethylene (87°C), and chlorfluoralkane ( 4 0 50°C). For expanded polystyrene beads they are usually incorporated during polymerization, for expandable polystyrene beads, or introduced into an extruder, for extruded expanded PS sheet. In some processes, plasticized PVC in a compression mould or other types of thermoplastic in a special injection moulding machine are saturated with nitrogen under about 200 bar pressure, the gas expanding the mouldings on secondary heating, or in the injection mould. Compressed air or CO2 is mixed into PVC plastisols for foams, which are subsequently gelled, for backing floor covering or conveyor belting.
15.3 Chemical Blowing Agents (CBAs)
CBAs are solid organic compounds that release nitrogen gas at a specific processing temperature. They are finely distributed solids, decomposing under heat, to release a gas. They may range from simple salts such as ammonium or sodium bicarbonate to complex nitrogen-releasing agents. Most CBAs generate nitrogen. Sodium bicarbonate releases carbon dioxide, but the reaction also produces water, which can cause rust on steel moulds. The CBA group also includes the CFC replacements, such as hydrochlorofluorocarbons (HCFCs). Polyurethane foams have also been developed using carbon dioxide as the blowing agent. Examples of chemical blowing agents are azo compounds, N-nitrosocompounds, and sulphonyl hydrazides, which yield 1 0 0 - 3 0 0 cm^ of nitrogen per gram of compound at temperatures of 90-275°C. Azodicarbonamide is widely used, having a decomposition temperature of 230-235°C, which can be reduced to 155-200°C by means of metal compounds such as lead and zinc stabilizers. It can thus match the temperatures at which the melt viscosity of many polymers is suitable for foaming, and is used (typically) in calendered PVC and PVC plastisols and in structural foam forms of polyethylene, polypropylene, PVC, polystyrene, and ABS. Chemical blowing agents are added to the granular compound either in separate batch mixers or in a blending unit mounted on top of the injection moulding machine. With powder products it is recommended to add 0.1% adhesive to avoid subsequent separation. Liquid blowing agents can be added directly into the injection cylinder by a dosing pump, operating in parallel to the material feed. Chemical blowing agents can be classified as exothermal or endothermal, according to their energy requirements during decomposition. Exothermal blowing agents release more energy during decomposition than is needed for the reaction. Once started, decomposition continues spontaneously (and can continue after the energy supply has stopped). Parts blown this way must be cooled intensely, to avoid post-expansion. Typical agents are hydrazides and azo compounds. Due to possible skin irritation, precaution should be taken when handling these substances. Azo compounds are characterized by a yellow colour, which can lead to changes in colour of the mouldings produced.
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Endothermal blowing agents require energy for decomposition and gas release therefore stops quickly after the supply of heat is terminated. Shorter cooling periods are needed and moulding cycles are therefore shorter. The base materials are bicarbonate and citric acid - which are also used as food additives, and present no handling problems. Other blowing agents are under development for foaming engineering polymers and/or to overcome problems occurring, such as corrosion of screws, barrels, and moulds, and uneven cell structure.
15.4 Structural Foams
Thermoplastics can be foamed, giving useful structural properties while also saving in material weight and cost, with improved thermal and acoustic insulation. There are two basic technologies: direct gassing and the use of chemical blowing agents. Direct gassing is a process in which physical blowing agents (such as fluorocarbons, hydrocarbons, nitrogen, and carbon dioxide) are introduced into the thermoplastic melt during processing. Good distribution of the agent and thus a regular fine-cell structure are obtained by adding a nucleating agent. Chemical blowing agents decompose during processing to form gaseous decomposition products that produce a cellular material. They can be mixed directly with the plastics compound, in granular form. The main criteria are: good gas yield, regular cell structure, harmless decomposition products, and minimal influence on properties and colour of the finished product. Most blowing agents conform to international health and food regulations, and are classified as GRAS (Generally Recognized as Safe) under FDA regulations Table 15.3 Typical processing temperatures for thermoplastics Resin/application
LDPE/EVA LDPE (direct gassed injection) HDPE/PP TPE/TPU/TPR PS PS (direct gassed injection) ABS PPO/PPE/engineering resins Painted parts (PS/ABS/PPO) PET extrusion Co-injection of PP (foam core) Co-injection of PS, ABS (foam core) PC (reinforced) PVC boards, pipes, profiles Polyamide
Melt temperature °C
op
180-210 190-200 210-230 170-210 210-230 210-230 230-360 240-270 210-260 230-260 220-240 210-260 280-310 170-190 240-270
350-410 370-390 410-450 330-410 410-450 410-450 450-500 460-520 410-500 450-500 430-460 410-500 530-590 330-370 460-520
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and meeting German food regulations (Bundesgesundheitsamt C III-2 7063365/79). Chemical blowing agents can be processed on standard injection moulding machines. It is advantageous to use a shut-off nozzle to prevent the melt from premature foaming and 'drooling'. To achieve a uniform foam distribution together with a solid skin, the gas should expand in the melt after injection into the mould and injection speed should be as high as possible (possibly with the aid of a gas pressure accumulator). Dedicated foam-making machines have a separate plasticizing unit and transfer cylinder for faster injection. Blowing agents will, typically, comprise a range of grades which commence decomposition at 135-240°C, with recommended processing temperatures ranging from 170-215°C to 285-310°C. Typical processing temperatures for thermoplastics are shown in Table 15.3. 75.4.7 In-House gas generation
For larger users of nitrogen blowing agents, an in-house gas generation system has been developed by Air Products (under the name Prism HP). It separates 99.5% pure nitrogen gas from the air and stores it in a low-pressure storage buffer. From there, the gas is passed to a high-pressure compressor, which takes it up to 350 bar, and then to high-pressure buffer storage. It can then be delivered to the moulding machine(s) in the factory through a high-pressure distribution network, via localized control units with user-friendly graphic interfaces. 75.4.2 Nucleating
agents
Nucleating agents and regulators of pore size play an important part in physically and chemically blown thermoplastic foams, helping to produce a uniform cell structure. They are fine-particle solids or mixtures that release CO2 (such as sodium bicarbonate, with solid organic acids such as citric acid). 75.4.3 Dispersion
agents
These allow improved dispersion of fillers, especially useful when high loadings of alumina trihydrate are required for low smoke, halogen-free FR formulations. A small addition to the resin allows more filler to be added without increasing viscosity.
15.5 Syntactic Structural Foam
As an alternative to blowing agents, it is also possible to introduce lightweight void-forming pellets or 'prill', manufactured from ultrafine ceramic foam. These are strong, insulating, and flame resistant, with a density of 1 0 0 - 2 0 0 kg m"^. Grades (such as Tecpril, from Filtec) are stable to 1050°C and exhibit no
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dimensional change due to changes in humidity, from 0 to 100% at 20°C. They cannot generate smoke or hazardous gases at high temperatures and resist attack by most chemicals. A syntactic foam produced by mixing a polyurethane compound with millions of tiny gas-filled microspheres has been used for high-performance footballs. Developed by the sports company Adidas and Bayer, the foam makes up the top one-third of the outer skin of the footballs. When a football is kicked, the microspheres restore its shape very quickly, producing a very high elastic recovery compared with other football constructions, with the effect that the ball deviates very little from its initial flight path.
15.6 Replacement of CFCs
CFCs have long been the most effective blowing agents for polyurethane foams, and many processes, such as rigid foam and integral skin moulding, have virtually been built around them. But, due to concern about the possible effect of chlorine-containing chemicals on the stability of the Earth's ozone layer, it was decided internationally through the Montreal Protocol to reduce the use and manufacture of CFCs and replace them with other chemicals. For polyurethanes this has been achieved with the introduction of other chemical systems, including water-based systems that generate CO2. There is no direct alternative blowing agent for polyurethane foams that combines the advantageous properties of CFCs and the trend has been to develop replacements specific to individual applications. Much has been achieved but the present blowing systems are widely regarded as interim solutions: in the longer term, the solution is seen in pentane-based compounds. The main CFC to be replaced is CFC R l l (trichlorofluoromethane), which offers high molecular weight and therefore low thermal conductivity, low boiling point and therefore good blowing action, high chemical stability, non-toxicity, non-flammability, and low price. The first potential substitutes were partially halogenated CFCs (HCFCs). These have significantly lower ozone depletion potential (ODP) than R l l , but it is still not zero. They are regarded therefore as only an interim solution and a complex withdrawal programme for HCFCs was agreed at the follow-up conference to Montreal, in Copenhagen in 1992 -essentially a stepwise reduction from 1996, reaching total removal by 2030. Additional national legislation has been enacted in some countries, concerned that this timescale was too long (current US environmental regulations call for complete phase-out of production and importation of HCFC by 1 January 2003). Future conferences may shorten the period. In addition to ozone depletion, the 'greenhouse effect' is important. Greenhouse warming potential (GWP) of a compound depends primarily on its reactivity towards hydroxyl free radicals, which in turn determines their concentration in the stratosphere. A second factor is their absorption capacity for infra-red radiation, primarily determined by bonds between carbon and
Modifying Processing Characteristics: Blowing Agents
183
fluorine. This is an argument against HCFCs and also against another possible CFC substitute, HFCs. Some companies have therefore concentrated on completely halogen-free alternatives, but it is evident that there is no universal replacement, and the subject is better dealt with on a material-by-material basis, as discussed in the following. 75.6.7 Flexible foams
Carbon dioxide formed through reaction of isocyanate groups during polymerization can serve directly as the blowing agent. The urea groups also formed are a problem, causing hardening of the PUR matrix, and new polyols have been developed to counter this effect. CFC R l 1 has therefore been replaced in virtually all types of flexible PUR foam. Foaming of PUR in a closed metal mould produces a temperature gradient in the foam in which the areas in contact with the good thermally conductive mould are cooler than the centre. If the blowing agent is selected so that it has a higher bofling point than the temperature in these areas, the resulting moulded product will exhibit a low-density foamed core surrounded by virtually unfoamed dense skins, making a useful structural foam component. The boiling point of the replacement agent is therefore critical. Flexible structural foams (as for shoe soles, steering wheels, and armrests) need a soft elastic core and a suitable R l 1 replacement is n-pentane, which has a boiling point of 3 6°C, only slightly higher than that of R11, with similar foaming properties. Flammability was a problem, but this has now been solved and many users have now switched to n-pentane. A non-flammable alternative is water adsorbed onto solid support material such as zeolite, silica gel, or activated charcoal, no longer reacting spontaneously with the isocyanate groups, but at an elevated temperature, desorbed from the support and able to react. Choice and modification of the support allows the temperature profile of the foam to be converted to a corresponding density profile by the amount of water liberated, and the process is now used successfully for production of automobile components. Rigid structural foams release more heat during the reaction and a blowing agent with a higher boiling point is needed - but this could cause severe foaming problems. A completely different solution has therefore been adopted, using tertiary butanol that reacts with isocyanate to form isobutene, carbon dioxide, and amine (which reacts with isocyanate to form urea). The first reaction is highly temperature dependent and therefore fits well with the desired temperature profile for formation of rigid structural foams, and has been largely adopted by producers. 75.6.2 Rigid foams
Replacement of CFCs in rigid polyurethane foams has been a much more serious problem, since the main use of these foams is as heat insulators and the main property required is therefore low thermal conductivity. Blowing gases of high
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molecular weight would be advantageous, but the boiling point of inert organic compounds also increases with molecular weight rendering them less suitable as blowing agents. Apart from halogen compounds, it is thought that there is no organic substance known that simultaneously meets all of the criteria of the user: a boiling point lower than 50°C and thermal conductivity less than 10 mW mK~ ^. Non-polar compounds such as hydrocarbons come closest to CFCs and HCFCs and cyclopentane is nearest to the ideal (though not perfect). After optimization and adaptation to cyclopentane, foam formulations are now giving insulation values for refrigerators virtually identical to those of R 11 with similar diffusion results. The European refrigerator industry has converted to cyclopentane, and the changeover is also starting in other sectors. Safety concepts for cyclopentane are essentially based on experience with n-pentane. The French public health administration (Counseil superieur d'hygiene publique de France) has expressed a favourable opinion on the use of Forane 141b as a blowing agent for rigid polyurethane foams for refrigerators and freezers. This was the first product to be granted this official approval and was the conclusion of more than five years of studies carried out by Elf Atochem with different partners to check that, within the framework of the present regulations, Forane 141b can fully meet users' requirements. The studies have demonstrated that this non-flammable product has toxicological characteristics that allow its use in existing industrial facilities and, in particular, in refrigerator wall panels. It has physical properties leading to a thermal insulation efficiency that is higher than other industrial processes. A non-ozone-depleting chemical blowing agent developed by AUiedSignal is HFC-245fa (hydrofluorocarbon), for use in rigid polyurethane and polyisocyanurate foam insulation applications, including refrigerator and freezer insulation foam, and also in boardstock for roofing and sheathing and spray foam for construction. The new agent is non-flammable and is not considered to be a volatile organic compound. The insulation performance matches that of HCFC-141b and is superior to other non-ozone-depleting products, such as hydrocarbons and HFC-134a, claims AUiedSignal. For the USA, the EPA has scheduled HCFC-141b for phase-out on 1 January 2003. Honeywell's new HCFC replacement, HFC-245fa, has received approval from the EPA. It is intended as a replacement for HCFC-141b in a range of rigid polyurethane and polyisocyanurate foam insulation applications, including foam for insulation of refrigerators and freezers, boardstock foam for construction of roofing and sheathing, and spray foam, also for construction. The new blowing agent is non-flammable and is not considered a volatile organic compound, offering worldwide a safe alternative to use of hydrocarbons. It also offers an insulation performance matching the HCFC it replaces and superior to other non-ozone-depleting products, such as hydrocarbons and HFC-134a. 75.6.3 Pentane
It is expected that the trend towards use of carbon dioxide will continue but, where it is not possible to achieve the necessary properties, flammable organic
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185
compounds will be used. Expensive, partially fluorinated HFCs with their relatively high GWP will only be used where non-flammability is essential. Chlorine-containing compounds, however, must be replaced completely. Pentane presents itself as a possible solution to finding an efficient blowing agent which also meets environmental regulations, and years of experience in using it have shown that processing can be safe, as long as safety devices are fully implemented. Bayer's PU machinery subsidiary, Hennecke GmbH, has developed a state-of-the-art system that monitors all critical control points along the processing chain, to ensure safe production. Among the features are: • • • • •
completely encapsulated machinery and units (including in-line blenders, work tank, and high-pressure reaction casting machine), also aerated and fitted with exhaust devices, pentane gas sensors, and other safety devices; a metering and blending supervisory system (Pentament), also permanently vented to prevent gas build up; an electronic security system controlling all safety features, which can shut down operations, if necessary; pentane gas warning sensors monitoring all critical components; and an independent decentralized control system, alerted to all trouble indicators from primary and secondary sensors and monitors.
The modifications were designed to add safety checks to all critical points, first pinpointing all potential hazards (such as ignition sources, leakage points, and static charging) and then developing integrated safeguards. Bayer and Apache Products have discovered that, by extrusion mixing of high levels of fillers and/or diluents in a PU formulation, loadings of 10-50% filler by weight can be achieved while maintaining or improving key physical properties. The technology makes it possible to handle high-viscosity dispersions effectively, which may reduce production costs of rigid boardstock. Use of solid fillers, solid combustion modifiers, and hollow fillers was studied, suggesting that the higher cost of hollow fillers can be offset by density reduction in the foam board and increase in compressive strength. Use of this more environmentally friendly alternative may be facilitated for manufacturers of domestic appliances following the introduction of new safety features in the CycloFlex and LinFlex systems for refrigerator cabinet production. Hennecke Machinery has developed a comprehensive safety system for pentanebased foam production, meeting many of the reservations of US manufacturers of PU board. 75.6.4 Expanded
polystyrene
The blowing agent for expanded polystyrene in the past was dichlorodifluoromethane (R 12), with a co-blowing agent. The progressive replacement is shown in the table below, leading to carbon dioxide and replacement of the co-blowing agents methyl chloride and ethyl chloride by ethanol for toxicological reasons.
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Table 1 ?.4 Replacement of blowing gases for expanded polystyrene Period
Blowing gas composition
Comment
Until 1985 1985-1988 From 1988 From 1990 From 1992 From 1994
R 1 2 + methyl chloride R 1 2 + ethyl chloride R 12 + ethyl chloride + carbon dioxide R 142b + ethyl chloride + carbon dioxide R 142b + ethanol + carbon dioxide Carbon dioxide
Methyl chloride in Class 111 b^ R 12 reduction HCFC instead of CFC Ethyl chloride in Class 111b'' HCFC elimination
^ German hazardous substances regulations. Source: BASF
75.6.5 Economics of CFC
replacement
The investment required for switching to an HFC-245fa PU system may be less than originally believed, according to a study of appliance manufacturer Whirlpool. A major concern of the appliance industry has been the relatively low boiling point of the blowing agent (at 15°C), but the research shows that this does not demand processing at temperatures lower than those generally in use in the appliance industry today. Additionally, the processing window for HFC-245fa foams does not appear to be radically more limited than HCFC-14lb systems. Existing foam equipment should be capable of processing good-quality foam blown with the new agent, concluded Bayer and Whirlpool. 75.6.6 Festing the insulation value of blowing
agents
A method of testing the conductivity of various blowing agents in the vapour phase, providing a means of predicting the insulation value of the resulting foam, has been developed by Bayer. The insulating properties of the foam are primarily determined by the blowing agent. Essentially an experimental procedure based on the transient hot wire method, with apparatus developed in cooperation with the University of Stuttgart, Germany, it has been tested for vapour-phase thermal conductivity of 10 blowing agents, of which CFC-11 showed the lowest level. Of the alternatives, cyclopentane showed the next best results, especially at low temperatures (which is a key point for refrigeration). The method is claimed to give accurate results and provide absolute values. No calibration is required (as, for example, when a gas chromatograph is used) and the method and resulting data are useful in modelling and predicting the insulation value of the foam produced with the blowing agent.
15.7 New Developments
Endex ABS 50 is a new endothermic foaming agent for a wide range of thermoplastics, including polycarbonate, polyphenylene ether, nylon.
Modifying Processing Characteristics: Blowing Agents
187
polyethylene, polypropylene, and PET. A 50% active pelletized concentrate, it generates fine closed-cell foams leading to high-quality mouldings and extrusions. Faster cycle times and extrusion rates are combined with elimination of sink marks, functioning as an effective nucleating agent for direct-gassed products. Environmental Products' EPIcor 972 is a 70% active endothermic foaming agent concentrated in a universal carrier resin, claimed to have the highest gas yield of any on the market. EPIcell 700 is an exothermic chemical foaming agent for cellular plastics and rubber, for use with PE, PVC, EVA, and TPO. For structural foam in PC and PC/ABS, POLYcor 263 is an endothermic/endothermic mixture in a polystyrene carrier, and POLYcor 288 a combination of an acid/ carbonate and 5-phenyl tetrazole in one pellet. The former gives a finer structure, reducing cycle time with excellent surface properties and fast gassing. Quantum has introduced Spectratech chemical blowing agent concentrates giving high gas yields at low processing temperatures: FM 2169H is endothermic, compatible with PS; FM 2171H is endothermic, compatible with styrenics; and FM 2182H is compatible with polyolefins. A blend of hydrocerol and azodicarbonamide blowing agents is offered by Bl Chemicals, for PVC, thermoplastic elastomers, and other low-temperature processing thermoplastics, in appUcations requiring high gas yield and weight reduction. It is in the form of a yellowish free-flowing powder, reported to have good storage stability. Decomposition begins at 120-140°C and working temperatures of 120-170°C or higher are recommended. 75.7.7 Liquid carbon
dioxide
New technology allowing the use of liquid carbon dioxide as a blowing agent for flexible polyurethane foam products has been developed by Gusmer-Admiral, Ohio, USA. It is being used commercially by Japanese manufacturers who are reported to have found it both reliable and affordable. The process is claimed to offer a solution to the challenges presented to the industry by the mandated phase-out of commonly used blowing agents such as methylene chloride. Rather than pre-blending the blowing agent with a polyol before injection into the foam mixing chamber, the process uniquely introduces a stream of liquid carbon dioxide directly into the mixing head. This allows the moulder to stop and start injections of short duration, without altering the concentration of carbon dioxide in the reacting mixture, and without the need to re-circulate the gas back to the day tank of the machine. It uses a double-acting piston pumping system, providing precise control of the liquid carbon dioxide. The system allows re-circulation at pressures of up to 3000 psig, and the control system provides for very tight control of temperature of the re-circulating liquid, with built-in capacity to account for changes in carbon dioxide density with respect to temperature. The mixing head also allows either of two polyols to be selected for reaction with the isocyanate, and the moulder has the choice of pouring with or without carbon dioxide, on an intermittent basis, allowing better control over dispersion, solubility, andpre-expansion.
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CHAPTER 16 Modifying Processing Characteristics: Modifiers and Processing Aids Table 16.1 At a glance: process modifiers and processing aids Function
Improvement of processability of compounds: lubrication, higher output/lower energy; modification of polymer properties: nucleation for greater product homogeneity; clarifying agents for improved transparency
Properties affected
Productivity; product quality, transparency
Materials/characteristics
Fluoropolymers; sorbitol clarifying agents; elastomeric property modifiers, polybutene, acrylic; silicone modifiers; MBS, acrylic impact modifiers; fatty acid dispersion aids
Disadvantages
No significant disadvantages known
New developments
Improvement in productivity, energy requirement for processing
16.1 Impact Modification
The improvement of physical properties, particularly impact strength, is the role of an important group of additives, both for thermoplastics and thermosets. The aim is to compensate for inherent brittleness, or embrittlement occurring at subzero temperatures, notch sensitivity, and crack propagation. The mechanism is normally to introduce a component that can absorb the energy of an impact, or dissipate it. One of the main methods is to introduce microscopic particles of rubber, but there is also considerable interest in the surface treatment of fillers and other additives, such as pigments, to give them an impact modification function also and so add to their value. An key requirement of an impact modifier is its ability to bond, either mechanically or, more recently, chemically, with the matrix polymer. It is important, however, to differentiate between impact modification and reinforcement. In some polymer matrices, reinforcement such as glass fibre actually makes the matrix more brittle (and an impact modifier has to be included).
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Early development concentrated on the improvement of standard plastics, such as the thermosets, phenolic and polyester resins, and the thermoplastics, polystyrene, PVC, and polyolefins. More recently there has been considerable development of impact modification systems for engineering thermoplastics. 76.7.7 Impact modifiers for PVC
Impact modifiers for PVC include methyl butadiene styrene (MBS) and acrylics. MBS modifiers improve the impact strength of PVC compounds without sacrificing the other characteristics. They are used for a variety of rigid and semirigid appUcations and processes, such as blow moulding of bottles, calendering of film and sheet, extrusion of profiles, and injection moulding of technical parts. Some types can also be tailored to suit specific requirements. Acrylic modifiers also significantly improve impact characteristics, but offer particularly good weather resistance. The main applications are profiles, pipes and sheets. Co-monomers are used in the reactor, but additive forms are gaining in popularity. 16.1.1.1 MBS modifiers MBS impact modifiers are used for PVC (transparent and low temperature applications, mainly in packaging), and for engineering thermoplastics, especially for low temperature applications (PC, PBT and blends). Rohm and Haas' Paraloid range covers a very wide range of applications. For example, KM 3 55 gives low die swell, resulting in low post-extrusion shrinkage (reversion), improving throughput rates. In free-flowing powder form, it can be handled in automatic weighing and conveying systems. A new grade is Paraloid HIA 80, giving high impact performance with good clarity and weather resistance, for use in outdoor applications. Paraloid KM 377 is an impact modifier for construction products, with improved impact and weather resistance and good gloss-holding properties and BTA 730 and 751 are MBS modifiers, respectively, for clear sheet and film and opaque non-weatherable applications. Paraloid BTA 780-S is a methyl methacrylate butadiene styrene (MBS) for PVC packaging applications, in particular for film and sheet, claiming a unique combination of impact, crease whitening resistance and clarity. 16.1.1.2 ABS modifiers Claimed to provide better optical properties than is normally available from MBS modifiers, with especially good haze and transparency, is an ABS-based high impact modifier for PVC, by GE Specialty Chemicals in its Blendex range. Blendex 415 also differs from conventional MBS modifiers by offering the superior chemical resistance and low crease-whitening performance associated with ABS. It will perform well in even the most demanding applications, giving good impact strength, melt strength and formability, at competitive cost. It is expected to find widespread use in extrusion applications, including manufacture of PVC bottles.
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16.1.13 Acrylic modifiers Acrylic impact modifiers are used for rigid PVC (particularly for weatherable building applications) and for engineering thermoplastics (polyamides, PC, PBT, PET). Table 16.2 A quick guide to impact modifiers Type
Application
Some typical brand names
Styrenics
Mainly for styrenes and ABS; latest types also for polyolefins and engineering plastics; can also be used with SMC/BMC
KratonG-Shell
Olefinic
Mainly for PE and PP; also for PBTs; function as compatibilizers
Dutral - Ausimont Nordel IP - DuPont/Dow Royaltuf- Uniroyal Exxelor, Escor AT - Exxon
Polybutadiene
PS, ABS
Diene - FirestoneKrynac - Bayer Taktene-Bayer
Polybutenes
Use with ABS, also for PP/EP blends
Acrylic elastomer
Gives 'super-toughness' to nylon 6
Dimer acids
Modification of polyamides and polyesters
Calcium carbonate, talc
Engineered (surface-modified) grades improve polyolefins
Cimpact (talc) - Luzenac Hi-Flex - Specialty Minerals Hydrocarb - Omya PoleStar,ZytoCal-ECC Winnofil-ICI
Silicones
'Core-shell particles' developed for compatibility with organic polymers: low temperature flexibility
WackerChemie Albidur - Hanse Chemie
MBS
Widely used in PVC; can also be used with engineering plastics (PC, PBT and blends), especially for low-temperature impact modification
Paraloid - Rohm and Haas
ABS/nitrile
For PVC, claimed to give better optical properties
Baymod-Bayer Blendex - GE Specialty Chemicals
Acrylic
Weather-resistant impact modifiers for PVC
Durastrength, Metablen Elf Atochem Kane Ace - Kaneka Paraloid - Rohm and Haas
EVA/PVC graft
Improves impact resistance of PVC, light-fast, good weathering, can also reduce plasticizer migration
Levapren-Bayer VinnoUt - Wacker
Coupling agents
Improve compatibility, bond strength between polymer and reinforcement or filler
Epolene - Eastman Hostaprime - Clariant Ken-React, Ken-Stat-Kenrich
Europrene - EniChem
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Kane Ace FM is an acrylic high weather-resistant impact modifier for PVC products such as window profiles, siding and business machine housings, based on Kaneka technology. It imparts good processability, gelation behaviour, heat stability and low die-swell in lead-stabilized compounds, at addition levels of 8phr. Elf Atochem's new generation Durastrength 300 is an acrylic modifier, for PVC profile and cladding. It offers improved rheology and low torque, optimizing mechanical properties together with processability, with higher screw speeds and improved output. Increases of 2 5-50% in output for the same impact strength have been demonstrated. Low-temperature properties are also superior. Also from Elf Atochem is Metablen S-2001, a silicone-modified acrylic impact modifier, for high impact strength and good weatherabilty in PVC. Rohm and Haas has added Paraloid KM 355 to its range, offering improved efficiency and cost-saving. It has low die swell resulting in low post-extrusion shrinkage (reversion), improving throughput rates. In free-flowing powder form, it can be handled in automatic weighing and conveying systems. A recent grade is Paraloid HIA 80, giving high impact performance with good clarity and weather resistance, for use in outdoor applications. Paraloid KM 377 is for extruded vinyl products for the construction industry, with improved impact and weather resistance and good gloss-holding properties. A graft polymer developed by Wacker (Vinnolit VK 802), based on ethylene vinyl acetate and polyvinyl chloride, improves the toughness of rigid, semi-rigid and flexible PVC mouldings. It can be used to product impact-resistant PVC films for pipe insulation, furniture films and credit card lamination, as well as selfadhesive films and labels. Available as a free-flowing white powder, it also features Ught-fastness and resistance to weathering and ageing and can also reduce plasticizer migration in flexible mouldings.
16.2 Elastomer Modification
Rubber has always been used as a component or additive to plastics. Essentially the rubber provides a network of 'buffers' in the plastic matrix, forming an energy-absorbing or dissipating phase, that will physically absorb or dissipate the energy of an impact, over a broad range of temperature (especially at the lower rather than the higher end of the scale). It is important, though, to choose a rubber with the right volume fraction, morphology and interaction with the plastic matrix is commonly obtained by in-situ reactor polymerization, grafting or melt blending. The classic technology is the modification of general purpose polystyrene with styrene butadiene to produce high impact PS. Butadiene has also long been used, especially in ABS. Polyisoprene is a more recent modifier. InitiaUy, modification could be achieved simply by compounding but, with improvement in technology, copolymers were developed and the function was taken upstream to the reactor. With the advent of polyolefins, a different system was needed, especially when, with the development of PP, it was clear that its useful mechanical properties fell
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off rapidly at temperatures below 0°C. A compatible elastomer, EPDM was used again, first as a mechanical blend and subsequently as a reactor-made combination. 76.2.7 Acrylic
rubber
Acrylic elastomers have previously been used only in the rubber industry and conventional polymers (EEA or core-shell acrylate polymers) are based on the rubber in hard phases. Based on the soft phase only, however, EniChem's Europrene AR uses original technology for modification of PA 6 with conventional acrylic rubber in granule form. It increases the specific rubber efficiency in the impact resistance characteristics, so differing from other traditional elastomers (EPR, SEBS) used in modification of nylon. A 'super-toughness' level is obtained with only 17% Europrene AR and impact resistance characteristics are better than those obtained with 2 0 - 2 5 % of other elastomers. Both the low level of rubber and intrinsic characteristics of the softphase acrylic increase the resistance to high temperature (Vicat B = 170°C) and the flexural modulus of modified nylon. The high thermal/mechanical inertia and the polarity of these rubbers also allow post-treatments to the nylon that were not previously possible. 76.2.2 Styrenics
Styrenic block copolymers and their compounds have been in widespread commercial use for many years, with many applications. With the latest technology, they have become particularly interesting as impact modifiers for plastics, both thermoplastics and thermosets. Most polymers are thermodynamically incompatible with others polymers and mixtures tend to separate into two phases, even when they are part of the same molecule, as in block copolymers. Poly(styrene-P-elastomer-P-styrene) copolymers, in which the elastomer is the main constituent, give a structure in which the polystyrene end-segments form separate spherical regions ('domains') dispersed in a continuous phase. At room temperature, the polystyrene segments are hard and act as physical cross-links, tying the elastomer chain together in a three-dimensional network, not unlike the network that is formed by cross-linking of thermosetting rubber during vulcanization. Well-known materials are the Kraton polymer range, originally developed by Shell, and are produced in several types. The D series has an unsaturated rubber midblock - styrene/butadiene/styrene (SBS), and styrene/isoprene/styrene (SIS) - and the G series has a saturated midblock - styrene ethylene/butylene styrene (SEBS) and styrene ethylene/propylene (SEP). The G series has increased resistance to oxidation and weathering, higher service temperature and better processing stability. The development of a second generation (such as the Kraton G series) introduced selective hydrogenation technology, allowing conversion of
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polybutadiene or polyisoprene into, respectively, polyethylene/butylene (S-ES-S) or polyethylene/propylene (S-EP-S) rubber. They can be compounded with other polymers, fillers, flame retardants, and other additives, often to as little as 25% of the S-EB-S polymer. They can be used in polymer modification of thermoplastics and SMC/BMC materials. Hydrogenated S-EB-S block-copolymers can be used with olefinic plastics such as PP and PE because of their higher temperature allowance, and even with engineering plastics that usually need melt temperatures well above 275°C. But for polar engineering plastics, such as PA 6 and 66, maleic anhydride functionalized polymers have been developed and commercialized. Systems available to improve impact resistance of high-performance plastics are given in the table below. Table 16.3 Kraton G as a compatibilizer Plastic
Kraton G-type
%
Impact (Izod, notched, 23°C)(kJm-^)
Without Kraton G
PA 6 PA 66 PET PBT PC Mod PPG
FG/G FG-1901 FG-1901 FG-1901 G-1651 G-1650
13/7 20 20 20 10 15
65 100 100 100 70 30
<5 <5 <5 <5 <10 <5
Source: Shell Chemicals
16.23
Polyolefins
Polyolefin impact modifiers are playing an increasing role, particularly with the flexibility of tailoring molecules offered by new catalyst technology. For example, DuPont Dow Elastomers has grades of ethylene propylene terpolymer elastomer (EPDM) based on Dow's Insight 'constrained geometry' catalyst technology, for modification of plastics. Under the Nordel IP name, they offer significant advantages, especially in improving low temperature impact. The proprietary catalyst technology allows a measure of control on the bond angle of the long-chain polymer, presenting a large and unhindered site for monomers to react. The reactivity of large monomers, such as ethylidene norbornadiene (ENB) is therefore high, producing a much more uniform polymerization. A modified ethylene/propylene/non-conjugated diene (EPDM) elastomer, Royaltuf X330 (Uniroyal Chemical), is offered as a toughness improver for PBT and produced as a finely dispersed phase, for easy processing. Extrusion-grafted functionalized polyolefin-based polymers (such as Exxon's Exxelor) - maleated or aminated - offer better polymer/filler adhesion as well as impact improvement in engineering polymers and compatibilization in blends and alloys. They function as impact modifiers, compatibilizers and adhesion
Modifying Processing Characteristics: Modifiers and Processing Aids
promoters, giving a valuable combination of properties for applications such as: • • • •
195
high-value
impact modification of engineering thermoplastics; compatibilization of polymer blends, in alloying and recycling; adhesion enhancement of polyolefins to metal, glass, and polar substrates, by coextrusion, CTR, and extrusion coating; polymer/matrix adhesion to reinforcing agents, such as glass fibre and inorganic fillers, and to flame retardants, such as magnesium hydroxide.
Adhesion of EPDM elastomers to polar substrates, for radiator hoses and V-belts, and of general purpose rubbers to carcass in tyre sidewall compounds is also improved, as is co-vulcanization of EPDM with polar rubbers. They also offer low levels of residual ungrafted monomers, minimizing industrial hygiene problems and offer good colour with low level of contaminants and easy handling in compounding operations. Escor AT acid terpolymers can also be used, for better impact resistance. 76.2.4 Polybutene
Polybutenes (which have been used for many years as modifiers and extenders in butyl rubber) are now showing significant advantages in plastics, including polyethylene, polystyrene, and ABS. They have inherent tackiness, chemical and oxidative stability, and low permeability and also exhibit excellent colour and colour stability and are virtually non-toxic. Improvement in impact strength is also given to ABS, where low molecular weight polybutenes give best results. They can also be used in thermoplastic elastomers. In polypropylene/ethylene-propylene elastomer blends, polybutene modifiers give flexible compounds with good impact strength and processability. A study by Amoco showed that, at a level of about 50% elastomer content, there is no break impact at -20°C while flexural modulus values are high and melt flow is 80-100% higher than the unmodified blends (contributing to better processability). Polybutene tends to reduce the tensile strength, heat distortion temperature, and hardness of the blends, but compounds have a good general balance of properties. Potential applications include flexible automotive components such as airbag door covers and mudguards, gasketing, and wire jacketing and also the replacement of plasticized PVC in toys, sporting goods, tools, and other consumer items.
16.3 Dimer Acids
Dimer acids and their derivatives, dimer diol and dimethyldimerate, are longchain polymer grade fatty acids which act as good modifiers for condensation polymers. High amounts of aromatic structure and linear structure increase hardness and impact properties, respectively. They can be used to modify
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thermoplastic polyamides and polyesters (PBT, PET), and thermoplastic polyurethanes gain increased flexibility, hydrolytic resistance and low moisture absorption.
16.4 Calcium Carbonate
Modified calcium carbonate can serve also as a modifier, used mainly in PVC, both flexible and rigid. Coarser particles are used mainly, but, as compound specifications become more exacting, fine-particle stearic acid-coated grades have been introduced to give better mechanical and processing properties. Being white, these grades can also aid in pigmentation and can also assist gloss (including compensating for loss of gloss where lead stabilizers have been replaced by calcium/zinc systems). Hydroxyl groups on the surface of calcined kaolin can also participate in coupling reactions, increasing impact strength and heat resistance of polyamides. Anisotropy can also be adjusted in partially crystalline plastics, with or without glass fibre. Described as 'functional additives', ECC developed a range of products offering a high concentrate of 90% CaC03/10% polyolefin binder (compared with 6 0 70%, which is usually regarded as the limit) in peHet form, so that moulders and extruders can add the mineral direct, with good dispersion. In the mix, the mineral acts also as a heat conductor, so aiding processing and reducing the cycle time. The pellets are useful for bottles, household articles, caps and closures, and industrial packaging. For polyolefin films, ECC's FilmLink, in powder or pellet form, comprises very fine particles, averaging 1 |im in diameter, with narrow particle size distribution and surface coated with a substance compatible with organic compounds. Loadings are 60% or higher. They give increases in film strength that are described as 'dramatic'. Following introduction of an engineered calcium carbonate performance additive, ZytoCal, ECC launched a grade designed to provide a higher impact strength, ZytoCal SI. The additives are designed for use with polyolefins, in injection and blow moulding and other thermoplastic processes. Depending on the process and design of the moulding, productivity improvements ranging from 10 to 40% have been achieved consistently, claims ECC. The grade is based on an ultrafine engineered calcium carbonate in a self-dispensing pellet form.
16.5 Modification of CPEE Polymers
Mineral fillers can have a valuable modifying effect on block copolyether/ester elastomers (CPEE), materials which fill a useful gap between the classical thermoplastics and elastomers. The specific properties of CPEEs are related to their two-phase microstructure, built up of alternating flexible amorphous segments based on polyoxytetramethylene glycol and rigid crystalline segments
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197
based on poly(butylene terephthalate). They have good mechanical properties over a wide temperature range. Incorporation of fillers into CPEE, however, presents a problem, since the polymer is in the continuous phase and the filler in a dispersed phase. Intermediate layers of 0.001-120 jim thick are formed between filler and polymer particles, with a non-homogeneous structure depending on the properties if the polymer and filler and on the method of production of the system. A chemically active preparation of the filler surfaces is used industrially to increase adhesion and fillers containing an aminosilane or epoxy preparation are recommended. Materials with spherical particles (whiting, quartz flour, glass microspheres) have a filling effect, giving an increase in shape retention at elevated temperatures with reduced manufacturing cost. Fibrous fillers (glass, cotton, carbon) have a marked reinforcing effect, while flaky materials (talc, mica, graphite, molybdenum disulphide) have an intermediate effect. Calcium metasilicate causes an increase in flexural stress value while the impact strength is retained at its original high level. The elastomeric properties are retained if the mass percent of filler does not exceed 30%, as a result of the significantly lower L/D ratio of calcium metasilicate compared with that of glass and cotton fibre. Spherical fillers make it possible to retain the elastomeric properties and to increase the strength by almost 100%. A marked reduction in compound cost can also be gained, since most of the fillers are some 5-10 times less expensive than CPEE.
16.6 Modification of PMMA with Silicon and Phosphorus
Poly(methyl methacrylate) (PMMA) is a rigid and highly transparent thermoplastic, available as an injection moulding material and as cast or extruded sheet, that is widely used for glazing and advertising signs, both indoors and outdoors. It has good mechanical properties at room temperature but these deteriorate rapidly with a rise in temperature. PMMA is classified as slow burning (placing it on about the same level as wood). Any improvement on the thermal and flammability characteristics that may be produced by structural modification by use of additives is therefore very desirable. Work in Taiwan has centred on examination of polydimethylsiloxane (PDMS), which has unusual properties such as high dynamic flexibility, low entropy of dilution, high oxidative stability, and low glass transition temperature. The initial work was directed towards incorporating the functionalized polymer PDMS into vinyl block polymers, producing copolymers that are of considerable interest in fields such as adhesion, coating and printing.
16.7 Impact Modifiers for Thermosetting Resins
A wide variety of chemicals can be used to modify specific properties of the resin, such as resistance to mechanical or thermal shock, increased elongation and
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higher impact strength and flexibility. Usually this will involve a 'trade-off' of some other property, such as physical strength, electrical properties, resistance to chemicals or solvents, and/or performance at elevated temperatures. To improve impact strength, there are two routes (which may well be best used in combination): to modify the resin, or to improve the interface bond between the resin and reinforcement. There is a wide variety of chemicals that can be used to modify specific properties of the resin, such as resistance to mechanical or thermal shock, increase elongation, and higher impact strength and flexibility. Usually this will involve a trade-off of some other property, such as physical strength, electrical properties, resistance to chemicals or solvents, and/or performance at elevated temperatures. For epoxies, there are DER-type flexible resins and monofunctional epoxide compounds, such as epoxidized cashew nut oil flexibilizer. Typically 30% or less by weight of these can be used, they can also be used at ratios of 1:1 to obtain a flexible and rubbery cured composition. The additives are also shelfstable when blended with the resin. Modifiers that may also be reactive as curing agents (such as polysulphides, triphenyl phosphite, and some polyamides) can be used. Polysulphide polymers used on their own will react slowly with expoxies. One to three parts of an active catalytic amine or amine salt can be used to accelerate cure. Triphenyl phosphite reduces viscosity and lowers cost. Ratios up to 2 5 phr appear to have no severe effect on physical properties at room temperature. Although reactive with epoxy, triphenyl phosphite is not an effective curing agent by itself; it needs also a polyfunctional amine. About 75% of the normal stoichiometric amount of amine gives optimum results when 2 5 phr triphenyl phosphite is used with a resin such asDER331. Carboxyl-terminated butadiene acrylonitrile rubbers (CTBNs) are used as additives to flexibilize, toughen and improve the adhesion of certain epoxy systems, typically used at 3.5-20 phr. Nitrogen-containing curing agents are usually used with this resinous modifier to promote the reaction of the CTBN carboxyl groups with the epoxide groups of the resin, precipitating the rubber to form a two-phase matrix. The high viscosity of these resinous modifiers can, however, be a hindrance. Non-reactive modifiers such as dibutyl phthalate, pine oil, and glycol ethers are not used widely because they can cause severe reduction in cured resin properties. Their primary function is to lower cost and the chief requisites are that they are compatible with the resin both before and after cure, do not vaporize or foam during cure, and do not migrate excessively from the cured composition.
16.8 Processing Aids
As raw materials prices go up, more attention is being paid to additives that make materials go further in processing - and there is every likelihood that this trend will continue. Processing aids, based on a variety of chemicals, are increasingly
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used to make extrusions run thinner and faster, and to shorten moulding cycles. The compounds involved are PVCs and polyolefins, but nylons and other engineering plastics are beginning to benefit also. In effect, the focus is switching from the cost of the basic material to the cost of the processed product. Table 16.4 Typical processing aids Type
Function and main applications
Calcium carbonates
Surface-treated grades improve heat transfer, give faster set-up in moulding, improve bubble stability for blown film
Methyl styrenes
Standard processing aids for PVC: impact modifiers
Styrenes, acrylics
High molecular weight acrylic copolymers: improve processability of PVC compounds, good weatherability; lubricant grades reduce adherence of melt to processing equipment
Clarifying/nucleating agents
For polypropylene: increase rate of crystal initiation, improved clarity, better flow, faster set-up
Lubricants
Normal: reduce resin viscosity without adverse effect on properties: better flow at lower temperatures, reduced flow marks and knit lines. Nylon types: increased production, higher throughput and improved quality of film
Fluoropolymers
Forming a non-stick film in extrusion die, to reduce die build-up, avoid 'sharkskin' melt fracture, improve output, less equipment down-time
Silicone oils
Long-used as processing aid/internal lubricant, but difficult to handle
Engineered silicones
'Core-shell particles': organic shell makes particles highly compatible with other organic polymer systems, allowing selective adjustment of the silicone-modified phase. UHMW siloxanes: improved processing in polyolefins at 0.1-1.0% addition, reduced melt fracture/lower torque in extrusions, better mould filling and release, reduced warpage in mouldings
Functionalized polymers
Mainly for improved impact in engineering polymers; used as compatibilizers in blends and alloys
A long-standing name in PVC modification is GE's Blendex. A grade for PVC calendering, Blendex 590 process aid reduces surface defects and improves processing at a lower loading (30-50%) than conventional acrylic process aids. From the original methyl butadiene styrene (MBS) processing aids used for PVC, and silicone oils used to aid processing of other plastics, new technology has considerably expanded the field. Additives with specific functions (such as flame retardants, anti-statics, and conductives) are now also expected to make a contribution to facilitating processability. Traditional fillers, such as calcium carbonates, are surface modified to give them additional value and, at the other end of the spectrum, highly sophisticated polymers such as fluoroplastics are being modified to play key roles as processing aids. A new generation of process aid masterbatch is claimed by Cabot. Plasadd comes in two grades, for linear low-density polyethylene film with, respectively.
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3 and 2% addition of a generic process aid. The results include high output, potential temperature reduction, elimination of melt fracture and reductions in die pressure, torque, and addition levels. Using a 50% start-up concentration, melt fracture can be eliminated in 6-8 minutes. Up to 50% improvement in output has been achieved with a 2% addition level and, at 1% addition level, 10°C reduction in melt temperature, with no effect on output rate. Dispersion agents promote improved dispersion of fillers. This can be especially useful when high loadings of alumina trihydrate are required for low smoke, halogen-free flame-retardant formulations, but can also be effective in obtaining optimum performance from an impact modifier. A small addition to the resin allows more filler to be added without increasing the viscosity. A colourless odourless chemically inert polymer additive based on fluorinated synthetic oil that increases the abrasion resistance of both thermoplastics and thermosets, has been introduced by DuPont Performance Lubricants. Named Fluoroguard, it is for use in gears, bushings, automotive weather stripping, footwear, 0-rings, seals, and polymer films, along with many other applications. It also offers benefits in processing, by improving melt flow and release properties, reducing machine torque and die build-up, and increasing extrusion rates. 76.8.7 Low-temperature
flexibility
Resistance to extremely low temperature, with better thermal insulation, improved wear and better grip are some of the advantages claimed for a new compound for production of heavy-duty boots for construction workers. AW Compounder's Ultralex compound uses a Kraton G polymer additive, introducing advanced technology to the safety footwear sector. The polymer was chosen because it operates well in very cold conditions (down to -5()°C), as encountered in Canada, without cracking or losing thermal insulation. The extra grip in the sole helps the wearer to stand safely on uneven or wet surfaces, and the compound also provides good resistance to chemicals. Methyl butadiene styrene (MBS) and acrylic (PMMA), which are used widely as impact modifiers for PVC and engineering resins, also function as processing aids, for rigid and semi-rigid processes and applications, such as blow moulding, calendering, profile extrusion, and injection moulding of technical parts. Some types can also be tailored to suit specific requirements.
16.9 Clarifying/Nucleating Agents
Polypropylene normally crystallizes slowly into relatively large crystals known as spherulites which are larger than the wavelength of visible light and reflect light, reducing clarity and increasing haze in the material. Clarifying (or nucleating) agents increase the rate of crystal initiation and, because more crystals are growing in the same space, they are all smaller in size. A side effect is to improve the processing characteristics.
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201
Widely used in thin-wall moulded PP packaging are Milliken's Millad range, which have been shown to give a strong nucleation effect, contributing to faster processing, as well as giving high levels of clarity, gloss and moisture barrier properties. Grades can also be processed at temperatures above 260°C without plate-out or transfer of odour. According to Milliken, the 3988 grade makes it possible for clarified PP to match the aesthetics of more expensive packaging materials such as PET. In fact, an Italian processor claimed to be able to produce high-clarity PP packaging at halfthecostofPET. Plastic packaging made with the agent is claimed to eUminate taste and odour transfer to foods, liquids and cosmetics previously experienced with polypropylene clarified with earlier products. The additive is also said to give the best clarity and transparency available for polypropylene, leading to better consumer acceptance and giving package designers the flexibility to choose the economy and performance of this resin rather than others. In addition, because it does not 'plate-out' even at processing temperatures of 285°C (typical for many polypropylene fabrication processes), it significantly reduces the problems that tend to clog production equipment and cause considerable downtime.
Figure 16.1. A new dimension for polypropylene is signalled by the development of clarifying agents, such as Millad. (Photograph: Milliken Chemical)
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Table 16.5 Clarified polypropylene compared with other transparent packaging materials
Transparency/glass Cost/unit volume Hot-fill capability Moisture barrier Lower density Taste/odour transfer Drop impact strength Flexibility Stiffness Chemical resistance Oxygen barrier
PET
PS
PVC
=
=
=
++ ++ + ++ -1-
+
+ ++ ++ +
=
++ ++
+ ++ + ++ +
= -
-
= -
-
=
-
+
+
HDPE
PC
Glass
++ ++ ++ ++
++
Key: -H-, much better; +, better; =, comparable; -, worse. Source: Milliken Chemical
16.10 Fluoropolymers
New additives based on fluoropolymers have been introduced by DuPont and by Dyneon, to promote free flowing in polyolefins for extrusion and blown film production. They appear to act by coating the interior surface of the extrusion die with a microscopically thin non-stick film, which reduces friction at the resin/die interface and allows the extrusion compound to flow freely and more rapidly through the die opening. The non-stick properties also prevent accumulation of resin particles at the exit of the die, so eliminating the major cause of die build-up. The coating is continuously renewed by the additive through the extrusion process. The DuPont product is named Viton FreeFlow SC and RC and, unlike earlier types of fluoropolymer additives, they can be mixed into many pigmented masterbatches, with less interaction. The Dyneon grades are marketed as Dynamar PPA. The latest fluorocarbons comply with most world food contact legislation. Fluoropolymers help production of clear smooth film and other products with less surface defects, shifting the point at which 'sharkskin' melt fracture begins. They can be used to combat build-up problems with pigments and fillers and reduce surface defects in extrusion blow moulded products, pipe, wire, and cable. Small amounts can be combined with other ingredients, such as pigments, antioxidants, ultraviolet stabilizers and the like, to provide compounds with built-in protection against melt fracture and die build-up during processing. As well as improved output, processors gain extended use of equipment and greater flexibility in speed, temperature, pressure, and gauge control, with a wider choice of blend ratios. There is less downtime for cleaning die apertures and start-up is also easier. The latest types can also be mixed into many pigmented masterbatches with less interaction. The effects become apparent after the additive has coated the metallic surfaces of the equipment, requiring 15-60 minutes 'conditioning time', depending on
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203
equipment and processing conditions. Addition level should start low ( 2 0 0 - 4 0 0 ppm) and then increased in 1 0 0 - 2 0 0 ppm increments every 3 0 - 6 0 minutes, or until processing criteria have stabilized. The evaluation resin should contain enough anti-oxidant to prevent thermal degradation from causing rheological changes during evaluation. Most other additives - such as anti-oxidants, slip additives, and acid scavengers - are compatible; some, such as stearates, antiblocking agents, inorganic pigments, and hindered amine light stabilizers, may interfere with performance at high levels of loading. Table 16.6 Effects of PPA-1 on processability of HDPE resins (capillary rheometry 190°C) Resin (melt flow rate)
PPA type (level, ppm)
Apparent viscosity (Pa) 600 s-i
1000 s-i
HDPE-1 (0.4)
No PPA, melt mixed resin PPA-1 (1000)
355
278
260
200
Matte < 600 s'^ CMFat2900s-i Glossy at 3000 s-i
No PPA, melt mixed resin PPA-1 (1000)
390
272
Matte at 600 s"^
390
250
Glossy at 1600 s-^
No PPA, melt mixed resin PPA-1 (800)
515
378
320
264
Sharkskin < 2 0 0 s - i CMF at 1000 s-' Glossy at 1600 s-'
HDPE-2(0.5)
HDPE-3(1.4)
Melt fracture behaviour^
" CMF = cyclic melt fracture. Source: 3M Company, Specialty Fluoropolymers Dept
16.11 New Developments 76.77.7 Core-shell
rubbers
Simple blending of polybutadiene or a conventional styrenic block copolymer into a polar thermoplastic does not usually improve impact strength, as the process does not produce the necessary particle size or the required degree of interfacial adhesion. So-called 'core-shell' rubbers, however, offer a composite nature that is attractive, since a rubbery core provides the impact resistance while a glassy grafted shell gives rigidity over a range of particle sizes and shape, across a range of processing conditions. This approach is used with polycarbonate, because of the good compatibility of a PMMA shell with the matrix polymer. It can also be used to toughen PBT, particularly if the blend also contains some polycarbonate to facilitate dispersion. In polyesters, most of the attention has been directed towards poly(butylene terephthalate) (PBT), but recent work has focused on seeing whether the same concept holds good for toughening poly(ethylene terephthalate) (PET). PET is chemically similar to PBT, but has a higher melting point and slower rate of crystallization. Because of this, toughening systems used in PBT may thermally degrade in PET.
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Additives for Plastics Handbook
An alternative approach is to incorporate reactive functional groups into the elastomer, producing an in-situ graft copolymer. This reduces interfacial tension, improving dispersion in processing, and improves the adhesion of the rubber to the thermoplastic in the solid state. A maleated polystyrene/poly(ethylene-cobutylene)/polystyrene triblock copolymer (SEBS) has been used successfully to toughen polyamides and polyesters. It has been found that as little as 1% SEBS-^-MA in PET increases the fracture strain by more than 10 times. The graft copolymer acts as an emulsifier to decrease interfacial tension and reduces the tendency of dispersed particles to coalesce, while promoting adhesion between the phases in the blend. 16.112 Silicones
Core-shell technology has also been applied to the development of silicones as modifiers. They offer a combination of properties that makes them interesting as modifiers for plastics, improving impact resistance and giving resistance to change in temperature and weathering. But, because they are not compatible with organic polymers, it has often proved difficult to incorporate them into organic polymer systems. In particular, distribution and domain size of the silicone phase has been difficult to control. Wacker Chemie, however, has developed what it describes as 'core-shell particles': flexible silicone cores surrounded by an organopolymer shell, with precisely defined particle sizes and very narrow particle size distribution. The organic shell makes the particles highly compatible with other organic polymer systems, allowing selective adjustment of the silicone-modified phase in the host polymer compound. Properties that can be conferred by these additives include low-temperature fiexibility, resistance to changing temperatures and UV resistance. Undesirable effects, such as release and depression of surface tension, which in the past have been caused by migration of the silicone, have not been observed. 76.77.3 Modification
of engineering
thermoplastics
A new series of alloying agents has been introduced by Bennet Europe, aimed at improving the properties of polymer blends based on diverse materials such as polyethylene, polypropylene, polystyrene, polyamide, PET, and ABS, as well as allowing normally incompatible components to be combined with a chemical bond. Described as 'High Activity' (HA), they offer improved reactivity and have achieved higher melt flow with greater whiteness - features that result in improved end properties in the blends. The additive can also be used as a cleaning compound and improves pigment dispersion, allowing the required percentage of colour additive to be reduced. Cycle time in injection moulding polyethylene-, polypropylene-, or polystyrene-based materials can also be reduced.
CHAPTER 17 Modifying Processing Characteristics: Lubricants^ Mould Release Agents^ Anti-slip and Anti-blocking Lubricating additives can have both performances and processing functions in plastics compounds, and (within strict limits) they can be either internal or external. The same or similar additives can be used to reduce the slip and blocking tendencies (of, for example, plastic films). Table 17.1 Typical lubricants for various thermoplastics Host polymer
Typical lubricants
Polystyrene (crystal)
Clear-melt zinc stearate (bis-stearamides are usually adequate); secondary bis-amides assist flow
ABS
Metallic stearates in combination with glycerol monostearate; secondary bis-amides assist flow
Styrene/acrylonitrile
Fatty acid amines, amides, secondary bis-amides
PVC
Concentrations of calcium stearate and hydrocarbon waxes (serving, respectively, as internal and external lubrication): low molecular weight polyethylenes are said to be among the most efficient external lubricants; most systems also incorporate processing aids, to give faster fusion and higher gloss; primary amides improve non-stick of plastisol sealing gaskets; acrylic and styrene copolymers
Polyolefins
Primary amides for slip/antiblock agents in LDPE, LLDPE, PP films. Lubricants can tie up catalyst residues, usually calcium stearate; stearates and ethylene bis-stearamide waxes are sometimes used in processing of fine powdered polyolefins; erucamides preferred for films and mouldings; fluoropolymer 'alloys' give better use of machinery; methacrylate-reactive silicones
Polyamides
Special polyamide formulations improve film processing and performance
Engineering thermoplastics
Secondary amides (oleyl palmatamide, stearyl erucamide); cetyl palmitate and cetyl sebacate are used; epoxy-reactive silicones
17.1 Lubricants for Performance Improvement
For specific performance improvements, typical lubricating additives such as graphite, molybdenum disulphide, PTFE, polyethylene (and even lubricating oil
206
Additives for Plastics Handbook
itself) can be added to engineering plastics for applications in bearings and sliding elements. However, there are problem areas. Lubricants themselves are extremely complex, with widely differing properties. A slight difference in chemical composition of the lubricant can produce a marked change in properties of the host plastic and, as the lubricants are used up, materials can be formed which can damage the plastic; the effects on plastics of the many lubricants in use are still not fully known. Internal stresses can be also produced in the plastics during processing, which can have an adverse effect on the lubricant. Lubricants may be internal (incorporated into the host resin during production or compounding) or external (placed between the sliding surfaces before or during operation). Addition of PTFE to host polymers such as polyamide, polyacetal, polyphenylene sulphide, and PETP polyester considerably reduces their friction coefficients. Internal lubrication is not always the answer, however. In some cases (such as polyamide with 2 wt% silicone oil sliding against steel at a moderate speed and a low load), internal lubrication has been observed actually to increase friction. Practical experience shows that external lubrication, using oil or grease, is more effective than internal lubrication in reducing friction and wear of plastics, because there is a much wider choice of low-cost lubricants (including water, milk, and brine) and the friction of plastics can be reduced to a considerably greater degree than the friction of metals. Plastics can be lubricated to increase their load-bearing capacity and reduce friction, provided that there are no technical or economic obstacles to this. The effect of lubricants on processing should also be noted: they can improve the viscosity and flow of the compound, but they also tend to leach out of the compound, with results that may be difficult to predict. With new proprietary lubrication technology using polyamides, the US specialist compounder RTP has launched a range of compounds for low-cost bearing materials in lubricated environments. Under the name Splash Lube Gold, the compounds offer superior retention of tribological, tensile, and flexural properties, even after ageing for more than 4000 hours both in air and oil at 120°C. The toughness is said to be superior, with retention of more than 95% weld line strength. The compounds are designed to deliver top-level wear performance over a wide pressure/velocity (PV) 'window'. Typical applications will be thrust washers, wear sleeves, sealing rings, and pump bushings for heavy equipment, small engines, and transmissions.
17.2 Lubricants as Processing Aids
In processing, internal lubricants can be used to improve throughput, while external lubricants may be used as for mould release, again improving productivity. Lubricants usually act by modifying the viscosity of the melt, by introducing different surface energies at the interface between the phases. But simple sticking between the melt and the processing machinery (screws, barrels.
Modifying Processing Characteristics: Lubricants, Mould Release Agents, Anti-slip and Anti-blocking
207
and dies) can also be a significant brake on throughput (not to mention requiring frequent stoppages for cleaning down), and development and selection of lubricants has also been directed towards improving this. The efficiency of a particular lubricant represents its functional compatibility or ability to solubilize the host resin. Unfortunately, an external lubricant or mould release relies on incompatibility, forcing it to the surface of the part during the moulding cycle and very often significantly altering physical properties. Certain materials can be used for both internal lubrication (at a low addition) and for mould release (at a higher level), aiming at a balance in solubility and insolubility. The trend towards multi-functional systems, in which an apparently high-priced lubricant can more than pay for itself by modifying other properties, such as impact strength, low-temperature performance, improved distribution of other additives, and even moisture and gas barrier properties. The addition level is usually about 0.5-3.0%, depending on the individual recipe and process, but some of the new (expensive) high-performance grades can be effective at as low as 0.1% dosage. It is important to get the balance right. Under-lubrication can cause degradation and higher melt viscosities, but overlubrication can cause excessive slippage and reduced output. An imbalance of lubricant and stabilizer can cause plate-out or migration of pigment from the melt, so a certain amount of testing may be advisable. The key criteria for selecting lubricants are: compatibility/solubility with the host resin; no adverse effect on properties; the rate of migration; easy addition and a suitable melting point. There must be approval for specific appUcations (such as food or pharmaceuticals) and zero (or almost zero) retarding effect on gelation. The lubricant should not produce a reduction in melt strength and extensibility, but should have good transparency and good plate-out performance. Suitable materials for lubricants are metallic stearates, hydrocarbons, fatty acids and alcohols, esters, amides, and polymeric additives. 77.2.7 Metallic stearates
These are inexpensive and able to modify melt viscosity without delaying fusion and are probably among the most widely used internal lubricants. Among the disadvantages are that they are generally supplied as fine powders and so can cause a dust hazard or nuisance in processing. They also tend to exude from the polymer compound, leaving a surface residue, and are not generally suitable for mouldings that will require secondary finishing such as printing, painting, bonding or electroplating. 77.2.2
Hydrocarbons
These are non-polar materials including mineral oils, paraffin, microcrystalline waxes, and partially oxidized polyethylenes. These are inert and lack internal functionality. Incompatibility with the resin gives good action as external lubricants, but can also mean that the surface of the part is easily contaminated, particularly with simple waxes as opposed to low molecular weight polyethylenes.
208
Additives for Plastics Handbook
17.23 Fatty acid amides and esters
These are the classic lubricants, derived from natural oils and fats and acting by migrating to the surface. A wide range of fatty acid esters of polyols and other compounds is used as internal lubricants, especially in PVC. Good flow, surface finish and improved clarity can be achieved in most processes, using either compounded or dry blend formulations. According to type, they can improve mould release, melt flow, lubricity, and scratch/scuff resistance and reduce static build-up and wear. Primary amides include stearamide, oleamide, and erucamide. Amide wax is widely used, in rigid PVC as an internal flow-promoting lubricant, giving better slip and surface sparkle in rigid film and as an anti-block in plasticized PVC. In polyolefins it acts as an external lubricant, and promotes internal flow in styrenes and ABS. It also gives a considerable improvement in flow in engineering plastics. It can also be used as polymer and pigment carrier and as a wetting agent and viscosity modifier in pigment concentrates. Amides are used as slip and anti-blocking agents in polyolefins and other polymers, their selection and concentration depending on the degree of lubricity required. Generally, stearamide give the best anti-block performance, eoleamide and erucamides the best slip properties. Erucamide tends to be preferred for LDPE, LLDPE, and PP films, with good oxidative stability and low volatility. It also offers good release properties for injection moulding. Stearic acid and hydroxy stearic acid are good external lubricants, giving good release properties and smooth surface finish. Secondary amides include oleyl palmitamide and stearyl erucamide. These have good thermal stability, showing no appreciable breakdown below about 350°C, and are therefore suitable for lubricants for engineering/technical plastics with processing temperatures above 300°C. Secondary bis-amides are used as lubricants in styrenics and ABS, assisting in flow, mould release, and anti-caking properties. They are also used in PVC formulations as lubricants and antiblocking agents in film and sheet. Compounds of adipates, palmitates, sebacates, and stearates are used as lubricants and plasticizers for many types of plastics, including PVC and engineering plastics. Cetyl palmitate can be used in place of natural wax and can act as a lubricant for engineering plastics. Octyl and iso-octyl palmitate are clear oily liquids with anti-blocking properties and additional heat stability that are also used as plasticizers for PVC and as a viscosity modifier for plastisols. The stearates are used, broadly, as viscosity stabilizers in PVC and lubricant/flow promoters in PS and ABS, particularly where low-temperature properties are required. Cetyl stearate is used as a lubricant for engineering plastics. Acrylic, styrene copolymers. Copolymers of acrylics and styrene produce lubricants and processing aids for PVC that significantly reduce the tendency of the melt to adhere to processing machinery. They can be are used for most rigid and semi-rigid PVC production processes and for secondary processing such as thermoforming of film and sheet. They act by upgrading gelation from a slow
g
Table 17.2 Characteristics of acrylic processing aids
Y1
2.
Description: high molecular weight acrylic copolymers, as white free-flowing powders, to improve processability of PVC compounds: lubricant grades reduce adherence of melt to processing equipment
cn
Property
f2.
Unit
?. a
Typical grades PA- 1 0
PA-20 (tin)
PA-20 (CaIZni
PA-30 (tin)
PA-30 (lead)
PA-101 (tin)
PA-101 (Calzn)
0.5 5 3 1 .O 0.5 0.2-30.1 90
0.553 1 .O 0.5 0.2-30.1 90
0.540 2.7 0.4 0.2-33.2 33
0.540 2.7 0.4 0.2-33.2 33
0.518 0.13 0.5 0.2-29.9 14
0.518 0.13 0.5 0.2-29.9 14
h I? F
cv
Specific gravity Specific viscosity Volatile content Particle size distribution Bubble fish eye
g cm-' SP '%)
4951147
0.548 0.7 0.5 0.1-2 5 90
2. n
-$ C 4 53
m,
Procrssingproprrti~s(dosuge: 115 phr) Gelation (max.) s Constant torque Nm Die swell ( 3 0 rpm) '1, Roll torque Nm Heat stability min Haze %!
" Profile extrusion: screw torque (Nm).
E
70/60 27.9130.1 22.1j25.5 1491168 163 11.4
67/61 27.8131.2 24.8130.9 1491183 I60 10.1
54/47 21.3123.7 42.2J55.0 44.3158.8 100 11.5
65/47 29.2135.3 24.9134.3 1571214 160 12.8
192/116 22.1126.2 36.0/44.0 72.8193.6" 285
84/68 27.4126.6 26.311391134 200 9.3
114183 18.6118.9 36.51102/101 122 16.5
'$ 4
2-. z
G' n 4
2-.
210
Additives for Plastics Handbook
non-homogenous state to a fast homogenous melting process. Some types can also aid dispersion of other additives, improve production speed and rheological properties of a PVC melt, and enhance the mechanical properties and surface finish. 77.2.5 Polyolefin waxes These are highly effective external lubricants for PVC, with positive effect on gelation and surface quality of finished products. Polar polyethylene waxes have a pronounced anti-sticking effect and high molecular types are suitable for transparent items. Other waxes improve pigment dispersion and permit production of highly concentrated masterbatches with better colour yield. Montan waxes are excellent lubricants for many thermoplastics and thermosets. They are mainly used in PVC, where they have wide-range internal and external lubricating effect and worldwide approval under food legislation. The property profile of waxes in PVC is characterized by high anti-sticking effect and good flow improvement. In contrast with lubricants based on fatty acids these do not affect melt strength or Vicat softening point. They are compatible with other components even when added in large quantities. They are particularly suitable for critical processes making high demands on the lubricant, such as production of calendered film, blow moulded articles and products stabilized with calcium/zinc. They give good release properties with engineering plastics. Table 17.3 Effect ofan internal lubricant on injection moulding ofelectrical housing and cap'' Open/close (s)
Injection (s)
Cooling (s)
Holding (s)
Total cycle (s)
Improvement {%)
15 15 15 15 15
6 6 6 6 6
41 31 26 26 26
25 25 20 15 10
87 77 67 62 57
Control 11.5 23.0 28.75 34.5
" Shot size: 245.5 g; material: lO'X)filledpolypropylene. Source: Axel Plastics Research Laboratories
17.2.6 Polyamides There have been many developments of compatible lubricant systems for the improvement of productivity in processing polyamide resins (for food and medical products packaging). For example, AlliedSignal has developed a new optimized 'package', with performance equal or exceeding current industry standards, on a reduced additive content. The system has been developed specifically to exploit the improvements that have been achieved in film production equipment over the past few years, giving a spread of benefits that add up to increased production, higher throughput and improved quality of film.
Modifying Processing Characteristics: Lubricants, Mould Release Agents, Anti-slip and Anti-blocking
211
The new package is available with both homopolymer and copolymer materials, for nucleated and non-nucleated resins. EMS Chemie has developed Grilon MB additives, based on PA 6 or compatible copolyamides, for modification of nylon film. In masterbatch formulation, they improve processing speed by more rapid crystallization and presence of nonblocking agents. It is also possible to improve slip properties for the film and reduce coefficient of friction between film and steel, giving faster running on packaging machinery. An improvement in technology for lubrication of polyamide resins in packaging for food and medical products, is a new optimized package developed by AUiedSignal Plastics, for use with its Capron resins. Performance is said to equal or exceed current industry standards, with a reduced additive content. Among the advantages are: 100% dust-free system, virtually zero gel level, reduction of screen pack changes, and improved aesthetics for finished films. 77.2.7
Fluoropolymers
Fluoroplastic processing aids are designed for use in extrusion of polyolefins (including blown and cast film, wire and cable and blow moulding). They can be used to eliminate melt-fracture in blown film extrusion and combat problems arising from die build-up when running resins with pigments and fillers in LDPE and PE blends and in EVA, and can reduce surface defects in extrusion blow mouldings, pipe, wire, and cable. Additional benefits include extended equipment utility and greater flexibility in processing speed, die pressure, melt temperature, and gauge control and also permit down-gauging with linear LDPE or high molecular weight HDPE without loss of product quality or alteration to existing equipment. They are available as powder, pellet, or masterbatch concentrate and are effective at very low levels. The latest types can also be mixed into many pigmented masterbatches with less interaction. They act by coating the interior surface of the extrusion die with a microscopically thin non-stick film, which reduces friction at the resin/die interface and allows the extrusion compound to flow freely and more rapidly through the die opening. The non-stick properties also prevent accumulation of resin particles at the exit of the die, so eliminating the major cause of die buildup. The non-stick film is continuously renewed by the additive through the extrusion process. In effect, the additive shifts the processing point at which 'sharkskin' melt fractures begin when extruding polyolefin film, so giving higher production rates and improved appearance. They can also reduce the apparent melt viscosity, allowing processors to use high viscosity, high molecular weight resins in cast and blown films, and in blow moulding applications, producing bottles, pipes, and other high molecular weight products with superior gloss and improved quality at only minimal cost. The cost/performance ratio is optimized, it is claimed, because only a small amount of the additive is required to obtain superior results. For processors, as well as improved output, there is the advantage of extended use of equipment and greater flexibility in speed, temperature, pressure and
212
Additives for Plastics Handbook
gauge control, while there is also a wider choice of blend ratios. The time between scheduled cleaning of equipment can be lengthened, while there is less downtime for cleaning the die aperture. Start-up is also easier. Most also comply with regulations for indirect food contact, and food regulations for polyethylene and polypropylene. They do not contain any toxic chemicals and meet the requirements of the US Food and Drug Administration (FDA) as an extrusion aid in manufacturing extruded polyolefins for continuous contact with food. They are also stable at standard formulating and processing temperatures (see also Chapter 15). 17.2.8 Silicones
Conventional silicone oils have been used in plastics processing for a long time as internal and external lubricants. But, while they have produced the desired results across a broad range of polymer types and applications, they have in the past presented some problems in handling. They offer a number of advantages in terms of texture, strength, pliability and special finishes. Their excellent lubrication properties improve productivity while also offering other properties. The way in which the siloxane gravitates to the surface means that it can be used at addition levels that are many times lower, it is claimed, for the same properties and performance. At addition levels of 0.1-1.0% siloxane by weight in polyolefin compounds, the processing aid advantages are highlighted, giving reduced melt fracture and lower torque in extrusion processes, better mould filling and release with reduced warpage of parts in moulding operations. When the level is raised to around 5%, the lubrication effects are intensified, giving films with better lubricity and slip and a lower coefficient of friction, while moulded products gain better mar resistance. An epoxy-reactive grade can be used with polyamides, polycarbonate, PPO, PBT, and PET polyesters and thermoplastic elastomers; a methacrylate-reactive grade is suitable for polypropylene, polyethylene, PVC, polystyrene, and ethylene propylene elastomers. To improve handling properties without reducing functional properties, Dow Corning has developed a range of silicone masterbatches as granulates with a high (50%) silicone content. Although chemically similar, the silicone component differs from the conventional silicone oils and, depending on the amount added, the coefficient of friction is reduced further, over a wide range of shear rates, and is substantially more uniform than when oils are used. Other advantages include absence of colour and odour, and approval for use in foodcontact applications. In PP extrusion compounds containing from 0.2 to 10% silicone, the output rate was found to increase with increase in silicone content. From 0.2 to 1% silicone, a 19% increase in output produced an increase of only 10% in power consumption. In general, tests show that, as silicone content is increased, the mechanical properties are somewhat impaired. This is less marked at lower processing temperatures.
Modifying Processing Characteristics: Lubricants, Mould Release Agents, Anti-slip and Anti-blocking
• • •
213
Up to 1%: SI powders reduce machine torque and power demand and may improve gloss and resistance to marring and abrasion; masterbatch gives improved internal lubricity, surface slip, abrasion resistance; 1-5%: increased surface lubricity, slip properties; restores impact strength lost in heavily loaded FR systems; Up to 15%: influences FR properties, significant reduction of heat release, slowing of CO and smoke generation.
The carrier resins are polyethylene, polypropylene, polystyrene, ABS, poly amide 6 and 66, polyacetal, and thermoplastic polyester elastomer. Dow Corning has also introduced a system that locks the lubricating additive into the surface, preventing migration. The system is termed 'surface segregation functionality', and is claimed to be a unique technology using new ultrahigh molecular weight siloxane masterbatches and offering a full range of lubrication, from improved processing to better slip and resistance to marring. New technology to utilize the properties of silicones more effectively in additives has also been developed by Wacker Chemie with what it describes as *core-shelI particles': flexible silicone cores surrounded by an organopolymer shell, with precisely defined particle sizes and very narrow particle size distribution. The organic shell makes the particles highly compatible with other organic polymer systems, allowing selective adjustment of the silicone-modified phase in the host polymer compound. Properties that can be conferred by these additives include low temperature flexibility, resistance to changing temperatures, and UV resistance. Undesirable effects, such as release and depression of surface tension, which in the past have been caused by migration of the silicone, have not been observed. 77.2.9 Boron
nitride
High-purity boron nitride (BN) powders have been shown to improve the lubricity in a variety of plastics matrices, according to Advanced Ceramics Corp, Cleveland, USA, the world's largest producer of standard and custom-made boron nitride powders. BN is a natural lubricant, which is used to improve parts that must be highly resistant to wear. It is also thermally conductive and an electrical insulator and can bring these properties to a plastics compound, as well as providing nucleation. The powders are large single-crystal materials with mean particle (crystal) sizes of 50 and 35 )im, respectively. Typical BN crystals are 15 |im or smaller, and agglomerates are also produced giving larger particle sizes, or over 250 jim.
17.3 Combination and Modification
As lubricants act by the precipitation of substances introduced to the phase interface of the heterogeneous polymer system - and this process is governed by the difference in surface energies of the components of the system approaching
214
Additives for Plastics Handbook
thermodynamic stability - it has been shown that pairs of typical lubricants, such as stearic acid, stearic acid amide, polyethylene wax PV-300, oxidized PE wax PVO-30, lignite wax, and hydroxyethylated lignite wax, can be effective at an addition level of 0.3% in a viscous low density polyethylene. Modification (such as oxidation of polyethylene wax and hydroxyethylation of lignite wax) leads to a reduction in the coefficient of surface tension, so making it possible to increase the effectiveness of the lubricant. But chemical modification that increases the surface tension (such as stearic amide) makes the lubricant less effective.
17.4 Release Agents for Thermosets
Release agents are required particularly when moulding thermosetting resins, such as polyester, epoxy and polyurethane laminates. An environmentally friendly, water-based external mould release, replacing solvent-based systems in tough polyester SMC/BMC and other highly filled resin moulding applications, has been introduced by Axel Plastics Research Laboratories, USA. A non-flammable product, it is an emulsion containing fluoropolymers, phosphate esters and fatty acids, enriched with a small percentage of alcohol to speed the drying process. The fluoropolymer component provides heat resistance with minimal transfer of the mould release to the moulded product. Multiple releases from a single application can contribute to reduced manufacturing costs and improved mould maintenance. The same company has developed a semi-permanent mould release agent designed for resin transfer moulding. Designated Xtend 19W, it gives a clean release with the toughest resin, including methyl methacrylate resins. In tests, the cost of the operation is claimed to be about 30-50% less than that obtained with other comparable products, while there are no signs of the usual build-up of a deposit on the mould surface. An advanced internal lubricant promotes flow and dispersion of additives in textured PVC panels (as used for automobiles and trucks). Called MoldWiz INTVP2 50, it is said to avoid the excess build-up in the detail areas of a textured mould that often occurs with conventional release agents and, unlike stearates, it does not exude, which is often the cause of uneven surface areas. Cycle times are also reduced, together with moulding temperature and pressure. It does not adversely affect the physical properties of the moulding, or impair secondary operations such as decorating, printing, bonding, or plating. For best results, an addition of 1-10 parts per 1000 resin is recommended. The additive can be used in 100% active powder or pellet form, and can easily be dry tumbled, gravitationally fed or compounded directly into the resin to make a masterbatch. As well as improving mould release. Axel's latest Mold-Wiz pellets can reduce the resin viscosity without adverse effect on physical properties. This makes for better flow of the resin at lower temperatures, and reduced flow marks and knit lines on moulded products - all of which make a significant contribution to increased productivity. Compared with commodity lubricants, the MoldWiz
Table 17.4 Typical high-slip and anti-blocking masterbatches Slip agents
Let-down:LDPE film pm - 1 0 0 pm LLDIEVA 1 0 0 pm
- 50
Processing temperature ("C) Food contact Slip regulation Anti-block Comments
Source: Colloids
Anti-blocking
Combination
Non-food contact
Food contact
High clarity
High percentage
High clarity/non-food contact
High clarity/food contact
0.50-2.0 0.25-1.50
0.40-1.75 0.20-1.30
1.75-2.25 1.25-1.75
1.75-2.25 1.25-1.75
1.75-2.25 1.25-1.75
1.75-2.25 1.25-1.75
1.0-1.50
1.50-2.0
1.0-1.50
1.0-1.50
2 30 275 No Yes Very good Very good None None Permits extruder to incorporate correct amount of slip
300 300 Yes Yes None None Very good Very good Permits smooth unwinding of film; reduces film sticking together
230 275 No Yes Very good Very good Very good Very good Combination masterbatches permit controlled quantity of slip and anti-block
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Additives for Plastics Handbook
pellets will not leave a residue on moulded parts. The pellets are now available in several resin-specific proprietary formulations, containing no binders or fillers that could contaminate the resin. They are claimed to be highly effective at addition rates of as low as 0.2 5% by resin weight.
17.5 Anti-blocking, Anti-slip Additives
These additives are important in processing film and sheet, especially in downstream operations. They follow different forms, from incorporation of mineral particles in the polymer matrix to produce a microscopically roughened surface, to more truly chemical. Slip can be described as the ability of a film to slide over itself or another film. It is one of the factors which helps describe how easily films can separate (or bags can be opened). The use of slip additives may affect the performance of other agents (such as anti-static agents). The presence of fillers and pigments may also affect the performance of the sfip additive. Anti-blocking agents reduce the tendency of layers of film to stick together in tightly wound reels or stacked sheets. The use of an anti-blocking agent may affect the performance of other additives (such as slip or anti-static). It is therefore important that a full evaluation is carried out to determine the suitability of combinations of additives. Primary amides (erucamide, oleamide, and stearamide) can modify the surface of polyolefins so that the coefficient of friction and tendency towards blocking are reduced. After processing, the amides migrate to the surface: the choice and concentration depends on the required surface properties. They are often used in conjunction with anti-blocking agents such as silica or talc, showing a positive synergistic effect on final slip and antiblocking properties. Stearamide can also be used as a processing aid and impact modifier in ABS. Combination masterbatches have been developed to give the film extruder greater control over the quantities of slip and anti-block agent in the film, with a good balance of other properties such as clarity and freedom for use in contact with food.
17.6 New Developments
A fine-particle silicone additive has been developed by GE Silicones to improve the surface and surface interaction characteristics of polymers, rubbers and similar materials. A key application for the additive (Tospearl) is an antiblocking agent for thin plastics film. Added to the resin during compounding, the fine particle spheres (0.5±12 |im) protrude from the surface of the blown film to form a uniformly uneven surface that prevents adhesion between film layers. The particle size is selected depending on film thickness. The spherical shape of the particles, combined with good inherent lubricity of silicone, also improves the slip characteristics of the film.
Modifying Processing Characteristics: Lubricants, Mould Release Agents, Anti-slip and Anti-blocking
217
Being fully cross-linked, the additive does not act like other release materials such as silicone oil, migrating to the surface of the film and giving it a slippery feel, but is bound into the film surface, making it easier to handle in a processing environment. In addition to anti-blocking properties, the additive (which is approved for use in food-contact packaging) improves film clarity and increases the abrasion resistance. Ampacet: Product 100520 is a mineral anti-block that does not require hazard labelling as it does not contain heavy metals or diatomaceous earth. At 2.5% usage the 20% loaded LDPE-carried anti-block attains 5000 ppm active antiblock, with films showing 96% light transmission and 12.8% haze. Slip and antiblock agents based on Dow's Affinity polyolefin plastomers include: Ampacet 100329 (slip), which contains 5% erucamide, and 110342 (anti-block), which contains 20% diatomaceous silica. Daniel Products' Slip-Ayd surface conditioner range numbers 14 polyethylene micronized powdered waxes, giving a range of particle sizes and hardnesses, with improved resistance to blocking and abrasion. For rapid reduction in the coefficient of friction of blown film there is a highly loaded oleamide slip concentrate from Colortech: with high content (10%) of active ingredient, it can be used cost effectively as a mould release agent for
Figure 17.1. With an average particle diameter of 4.5 /xm, Tospearl is an advanced silicone anti-blocking agent. (Photograph: GE Silicones)
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injection moulding polyolefin elastomers and as a friction reducing ingredient in thermoplastic cap and lid gaskets. Croda Universal claims that proposed amide blends, replacing up to 50% of inorganic anti-blocks, overcome the tendency of conventional inorganic additives such as silica and talc to reduce gloss and transparency in films and possibly lead to scratching and adsorption of other additives. Products in the Crodamide range of fatty acid amides can impart controlled levels of medium slip, consistently and repeatably, giving coefficients of friction of 0.2-0.4, at low concentrations.
CHAPTER 18 Other Types of Additive: Miscellaneous Additives
18.1 Anti-bacterials and Biocides
Anti-microbial additives and fungicides are added to plastics to increase their resistance to micro-organisms such as bacteria, fungi, and algae, which can cause black pitting, pink staining or odour, impairment of properties, and reduction of product life. Polymers such as polysulphides and polyester-based polyurethanes are vulnerable, but the main culprits for microbial growth are additives such as plasticizers, starch fillers, lubricants, thickening agents, and oils. A main area is PVC, which is also used in many vulnerable applications. Plasticized PVC film can be attacked by micro-organisms, especially fungi, which use the plasticizer or other ingredients as a carbon source, producing discolouration, bad odour, tackiness and eventual embrittlement over a period of time. Microbial attack can be prevented by incorporation of a fungistatic agent during processing. Biocides act by interfering with the metaboUsm of microorganisms by blocking one or more of the enzyme systems. To be effective, however, the additive should migrate to the surface, a process that is influenced both by its chemistry and compatibility. Also influential is the internal structure of the PVC film (ingredients), as well as the processing conditions. Many chemicals have anti-microbial properties, such as quaternary ammonium salts, but few are suitable for use in plastics, requiring low cost, compatibility, thermal stability during processing, environmental stability, and safe and easy handling. Microbial agents must migrate to the surface of the plastic and prevent bacterial growth. Additives for preservation of plastics will, however, undergo a significant shift in consumption patterns, away from arsenic-based products (which currently account for over 70% of the market). The market leader is OBPA (10,10'oxybisphenox arsine), which, although seen as the most efficient and costeffective preservative for plastics and accepted by the Environmental Protection Agency as able to be used safely, is regarded as dangerous by consumers. However, the total US market is estimated to be worth only about US$30 million, and manufacturers are working more on adaptation of preservation additives used in other industries. It is estimated that the overall market will
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increase at a rate of about 6% year for the next five years, but the demand for non-arsenic based formulations will rise at 10-20% a year. N-(trichloromethylthio)phthalamide (Folpet) and isothiazolin will be the main additives preferred, but other active ingredients will also gain from the changeover. Offering an effective alternative technology for biological control, the range of JMAC biocides from Johnson Matthey has recently received food contact approval from the US FDA and German BGA. These are potent broad-spectrum antimicrobials, based on controlled release of silver ions. They are non-hazardous, non-irritant, and non-sensitizing, even in concentrated form as supplied, and are gaining wide acceptance in the polymer emulsion industry. The latest approvals cover use in paper coatings with aqueous and fatty foods, and resinous coatings. Good anti-mildew and algicide properties are claimed for a non-arsenic-based anti-microbial agent, Amical from Argus Chemical, which is also non-irritating. It is approved by the US EPA for plastics use. Low levels of dosage in plasticized PVC, polyurethane, rubber, and other products prevent embrittlement and premature decay. Akcros' Intercide ABF-2711 is a special formulation of OBPA biocide - 2% solution in di-(heptyl. nonyl. undecyl) phthalate plasticizer - for PVC pool- and pond-liners, tarpaulins, and marine upholstery. Ferro's Micro-Chek anti-microbial is an EPA-registered as an industrial antimildew agent for PVC, PIU and other polymers, particularly in stressful outdoor applications such as roof membranes. A biocide developed by Akcros Chemical in its Intercide range is a solid product in granular form, readily dispersing in low-density polyethylene and other polyolefins during processing, to give anti-microbial, fungicidal properties on the surface of the processed product. An important development in recent years has been the introduction of Microban, by the company of that name. Microban is an odourless, tasteless, and colourless ingredient that is incorporated into the structure of the polymer during compounding, using proprietary technology that introduces the additive into the empty spaces forming part of the structure. It acts by neutralizing the ability of organisms to function, grow or reproduce and is built directly into the structure of the gelcoat, so promising to last for the useful life of the product. Following extensive testing and evaluation, the biocide additive has been approved for food contact by the US organization NSF International. The certification means that the additive meets the requirements of ANSI/NSF Standard 5 1 , covering safety of plastics materials and components developed for contact with food in the USA. The NSF mark can now be featured on products containing the ingredient and in promotional literature and will also encourage manufacturers of food equipment, who already hold NSF approval, to use the additive in their products. DuPont has also introduced an anti-microbial product range based on inorganic additives which have lower active agents and are safe for use in applications such as medical packaging. Under the name MicroFree, it offers light-coloured powders that are unaffected by solvents and able to withstand high temperatures.
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A masterbatch has been introduced by compounder Hanna's UK subsidiary, Victor International Plastics. Under the name Neutrabac, the masterbatch can either inhibit or destroy bacteria on moulded products, depending on the addition rate. It has been formulated to work across a broad product range, but is particularly suited to polypropylene and polyethylene compounds. It has minimal effect on colours and is unaffected by other additives, including HALS and anti-statics, while being heat stable under normal processing conditions, to 250°C. The company sees considerable scope for the masterbatch in cooking utensils, cosmetic packaging, baby care products, bathroom accessories, and other germ-critical environments. It conforms to European Pharmacopoeia and used industry-recognized standards so that 3% addition will inhibit bacterial growth and 5% will destroy a wide variety of bacteria. A sheet from Royalite is based on an anti-microbial masterbatch, Actifresh initially with high impact polystyrene and polypropylene sheet incorporating Actifresh - for applications in food processing, white goods and bathroom products, but to be extended as demand increases for formed sheet in applications where fungus or germ propagation is a problem. A polyester gelcoat, based on Microban technology, has been introduced by Neste. The company sees it as particularly interesting for gelcoats on shower and bathroom equipment, sinks, tubs, vanity tops, food preparation equipment, and interior components for hospitals and boats. 18.1.1 Anti-allergy
agent
A fibre containing a repellent for dust mites (one of the leading sources of human allergies) has been introduced by the French specialist Rhovyl. Where previously the method was to treat finished textile products with massive amounts of acaricide sprays or moist powders, the French company has approached the problem by introducing a mite repellent in the fibre itself, using some unique technology. The new fibre, named RhovylAS+, incorporates an acaricide agent which is well known to allergy specialists, but the unique feature is that the agent is added prior to extrusion of the fibre. Products made with the fibre are claimed to retain their properties throughout their life, offering permanent effectiveness, proved by the Techniques Environnement Consultants (TEC) laboratory in Anglet, France. The fibre also contains the antibacterial agent already used in Rhovyl'AS antibacterial fibre. It can be used alone or in combination with other synthetic or natural fibres, to adjust technical qualities to meet all uses.
18.2 Degradation Additives
The urge towards recycling has also created strong interest in additives which might render plastics degradable, but experience has shown that the practical use of such materials is less than was originally estimated (see Chapter 20).
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18.3 Shrinkage Modifiers, Low-profile Additives Using fillers as a partial replacement for a reactive resin which shrinks on curing can reduce the shrinkage of the completed system. Any inert filler will decrease shrinkage, but the most commonly used are silica, clay, calcium carbonate, alumina talc, powdered metals, and lithium aluminium silicate. A new and revolutionary approach to obtaining low- and zero-shrink DMC and BMC mouldings is with the use of a combination of low-profile additive (LPA) and calcium carbonate. The degree of shrinkage that can be achieved gives low profile mouldings with gloss levels rarely obtained before. The materials can be easily dispersed, giving exceptionally even pigmentation with none of the colour variations experienced previously with LPAs because of phase separation. In these additives, the calcium carbonate particle is coated with the appropriate polymer, resulting in a more efficient low profile action. Low- and zero-shrink grades are available, in natural white or black, which can be blended to achieve a specific shrinkage control to match the resin system. The products are in the form of beads of 80 jim mean diameter and are free flowing and less dusty than other powders. During compounding they disperse easily. Thermoplastic additives in RP help control shrinkage during cure, permitting good control of tolerances, dimensional accuracy, and surface finish to A classification.
18.4 Improved Barrier Properties Additives that improve the barrier properties of compounds (to liquid, gas, and oil) are a key but specialized area of activity. Development has been stimulated by the growing understanding of nano-technology. Selar platelet technology was developed a few years ago by DuPont for use in packaging and automobile fuel tanks. Ube Industries reports that the addition of clay to the nylon source material caprolactam before polymerization can reduce the gas permeability of nylons. The company terms the resulting compound a nylon clay hybrid (NCH) and has applied the technology to types 6, 66, and 12, with emphasis on food packaging grades. The clay is a stratiform silicate, added in 1 nm thick platelets. It reduces oxygen permeation from 45 ml m~^ per 24 hours for a standard PA 6 to 15-22 and in PA 6/66 from 44 to 9-23 m~^ per 24 hours. There is a small reduction in tensile strength, but the process improves stiffness and heat resistance. A high barrier nylon film has been developed by Bayer, also using nanoadditives and Nanocor, USA, has developed an aluminosilicate with platelet-type particles in the nanometer (0.001 |im) size range has been shown to reduce permeability to gases by up to 45 times in polyolefin, PET, or EVOH films. Correctly added, the platelets overlap and present a difficult path to migration of molecules through the film.
other Types of Additive: Miscellaneous Additives 18.4.1 Gas barrier
223
coating
A new generation of gas barrier coatings for PET bottles has made its debut in the USA, on single-serve juice bottles produced by Graham Packaging. It has been developed by PPG Industries, in its Bairocade range. Fully compatible with existing recycling technology, the coatings are an epoxy amine, applied by electrostatic spray and cured on infra-red ovens which create the gas barrier and produce a glossy finish that resists scuffing and improves the hazy look typical of PET containers. Bairocade coatings comply with US Food and Drug Administration regulations and do not alter the identification code of PET for recycling. Coated bottles can be processed through existing recycling systems, as has been proved in three industrial scale trials and independent laboratory tests, confirming that conventional recycling technology separates the coating from the PET for disposal as non-hazardous waste, allowing the bottles to be recycled back to fibre, strapping, sheet or even single-layer food and beverage containers. The coatings are being applied initially as clear coats, but the chemistry can provide a broad spectrum of colours (including amber, for the beer industry), that can be appUed to clear PET bottles without reducing the value of the recycled material. 18.4.2 Resorcinol
additives
Resorcinol chemistry can aid in developing high barrier polymeric materials, according to Indspec Chemical Corp. Three relevant derivatives are resorcinol dioxyacetic acid (RDOA), bis-(hydroxyethyl)-ether of resorcinol (HER) and resorcinol diglycidyl ether (RDGE). Six major breweries have successfully bottled beer in plastic containers: Miller, Heineken, Bass, Feldschlossen, Carlton United, and Carlsberg. The bottle for Miller Lite was developed by Continental PET Technologies, using five layers, with a PA (nylon MXD6) barrier layer less than 5 wt% of the container. In Australia, Carlton United introduced a monolayer bottle coated with PPG Industries' Bairocade coating. Since the main component of these bottles is PET with a relatively low barrier, the expected shelf life is around three months but, with the development of improved oxygen permeability (P02) and carbon dioxide (PCO2), of the barrier materials, it should be possible to deliver bottles with a shelf life of 6-9 months. The industry is aiming at polymer combinations offering values of P02 < 0.5 BU andPco2 < 2 - 3 BU. P02 values and tensile strength of polyamides and polyesteramides incorporating RDOA monomer suggest that there is a tremendous opportunity for development of high barrier packaging materials, considers Indspec. The lowest P02 values indicate that monolayer containers with high gas barrier properties can be made and used for preserving the taste of beer over an extended period of time, without further modifications. MXD6 is a polyamide made from the reaction of MXDA and adipic acid, giving a P02 value of 0.6 BU. But a polyamide made from MXDA and RDOA shows a
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value of 0.25 BU. The very low oxygen permeability obtained suggests that a multi-layer container using RDOA-based polyamides can extend shelf life of products such as beer for longer than MXD6. Resorcinol chemistry is unique due to the meta-phenylene linkage of the resorcinol molecule. The asymmetrical nature of the derivatives offers improvements in products and processes and, for gas barrier polymers, such materials are expected to be more amorphous than crystalline, suggesting that packaging materials can be highly transparent. Meta-linkages are the reason for the exceptionally high gas barrier performance and the high flexibility of the linkages increases chain-to-chain close packing, and thus provides a compact backbone structure. Based on experimental results, polymers containing meta-phenylene linkages showed 30-40% reduction in oxygen permeability compared withp-phenylene groups. As well as offering high barrier materials, RDGE-based thermoplastics could compete with EVOH in many applications and a thermoset coating based on RDGE gives a good opportunity to modify the low barrier monolayer PET container, providing an efficient and cost-effective container for beer.
18.43 Plasma technology
Plasma technology has been harnessed on a commercial scale by the French machinery company Sidel to produce PET bottles with barrier properties claimed to be unmatched. Up to 30 times the normal barrier to oxygen and seven times stronger barrier to carbon dioxide are claimed for the bottles. This makes them comparable with glass bottles and metal drink cans, and offers a new approach to packaging in PET one of the most difficult products: beer. The process is called ACTIS (Amorphous Carbon Treatment on Internal Surface). It consists of coating the internal surface of a standard single-layer PET bottle with a layer of highly hydrogenated amorphous carbon, obtained from food gas in its plasma state. The coating creates a thin (about 0.1 jum thick) barrier inside the bottle. The food safety quality has been approved by the Dutch standards authority (which is also accredited to the European Union), and the coated bottle is 100% recyclable. The plasma treatment is carried out downstream from the PET blow-moulding machine, and is of a design based on the company's own well-proven rotary high-output technology. The first model, ACTIS 20, has 20 stations and can treat 10 000 PET bottles up to 0.61 litre size an hour. According to Sidel calculations, the cost price of 33 and 50 cl size containers is, in fact, less than competitive packages.
18.4.4 Oxygen absorption
in food
packaging
The presence of oxygen in packaged foods has long been known to be a key problem of preservation and shelf-life, producing colour degradation, loss of nutrient, changes in flavour and odour, and microbial spoilage.
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A more effective additive system, producing a clear packaging film incorporating a polymeric oxygen scavenging system that absorbs oxygen in modified atmosphere packages (MAP), has been introduced by Cryovac Sealed Air Corp. Named OS 1000, it is claimed to reduce the oxygen concentration inside the pack to less than 10% of that in conventionally packaged foods. The technology has been known for some time and, to minimize degradation, oxygen-scavenging (OS) films have been developed, containing pouches of iron powder or with special coatings. The action of existing OS films has been 'triggered' by excessive heat or moisture, but this system has had its limitations. Polymer-based scavenging systems can oxidize prematurely if exposed to moisture or high humidity prior to the products being packaged. The Cryovac system is believed to overcome this problem, with a film that is activated totally independent of moisture. An organic additive is used that does not oxidize until it is exposed to UV light. In addition, the film improves colour retention in processed meats and delays the growth of yeasts and moulds. It also slows the onset of aerobic microbial growth in fresh pasta. Data produced by Cryovac shows that, when stored at 4°C, the oxygen level in fresh pasta increases from 0.35 to 4% after 15 days when packaged in conventional MAP, and then falls steadily to about 0.03%. But, in the OSIOOO film, it immediately falls rapidly to a constant level of about 0.05% (03/99).
18.5 Hard Coatings
By using chemical vapour deposition (CVD) technology at a relatively low temperature, Nissin Electric, Kyoto, Japan, claims it is able to apply diamond-like carbon coatings to materials such as plastics and rubber, improving their properties of friction, abrasion resistance and insulation. Conventionally, this type of coating is applied by plasma at a temperature of about 200°C, which has limited its appUcation of surfaces such as metals and ceramics. The CVD technology, however, enhanced by a plasma source operated only intermittently (PECVD), can function at around 50-80°C. Combined with plasma washing in a specific atmospheric gas, it has been possible to coat thermoplastic materials with much lower softening points. Surface properties (such as sliding friction, abrasion resistance and insulation) are claimed to be equal to, or better than, fluorine-treated surfaces and can be achieved at lower cost. In addition, the coated surfaces have good long-term reliability. Nissin also reports that it has developed a flexible diamond-like coating, which can be stretched up to 300%.
18.6 Thermal Insulation
Hollow nylon filaments that contain ceramics, to store heat, have been developed in Japan by Unitika. The company has been producing Microart
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fabrics woven from hollow nylon incorporating a ceramic to give an effective thermal insulation, but its new advanced TM fibre contains the ceramic inside the hollow fibre itself. A special spinning technology and an advanced method of controlling the polymer have been developed. The company claims that the fabrics made from these fibres are bulky, light in weight and also water-repellent. It plans to start marketing them for outerwear, and is looking for sales of some 100 000 metres in the first year.
18.7 Fragrance
Additive masterbatches with fragrance have been developed by Clariant Masterbatches. Five flavours are available, initially for use with polyethylene, with let-down ratios of 2-10%. Formulations for other plastics are under development.
18.8 PVC Matting Agent
A novel matting agent for PVC, comprising very fine pearls of a cross-linked copolymer containing acrylic monomers, has been introduced by Elf Atochem's additives subsidiary Ceca. Under the name Acrylperl, it has a very fine powder structure (typically 2 0 - 3 0 }im) that promotes homogeneous distribution and outstanding dispersion in the polymer melt during processing. It is effective at addition rates as low as 0.3 phr (of resin): normal use is at 0 . 3 4 phr, depending on the degree of matt finish required. It is also stable at elevated temperatures and has no impact on the thermal stability of the PVC compound. There is no effect on mechanical properties, and the additive (which, unlike other matting agents, has no yellowing effect) is intrinsically UV resistant. In the finished product, it produces an even matt or frosted appearance as the particles on the surface diffuse light. It can be used effectively in many rigid, flexible and PVC plastisol applications, and is reported to be in demand in the construction sector, for door panels, skirting boards, window ledges, electrical boxes, cable runs, pipe connections, furniture, cladding, and floor and wall coverings. It remains effective in thermoforming, as the bead-Uke structure is cross-linked and is not affected by heat. It also functions, at lower addition rates (of 0.1 phr) as an anti-blocking agent in calendered or blown films, the finely frosted finish imparted by the beads significantly reducing the tendency of films to stick together.
18.9 Anti-fogging
Anti-fogging - resisting the release of ingredients that can be deposited on nearby surfaces and cause fogging - is particularly demanded by the automotive industry for materials used inside a car. It especially affects PVC and
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227
polyurethane formulations but, in most cases, is tackled by manufacturers at the polymer level. Fogging can also occur in packaging, and most additive suppliers have developed formulations and concentrates. Typically, Ampacet Antifog PE MB is a new blown film concentrate in LDPE/ LLDPE carrier combination, with optimum anti-fog properties at typical let-down of 8%, acceptable for food contact in North America and Europe. An anti-fogging concentrate for food packaging film is Accurel 95CM209. Based on an LDPE microporous carrier containing 25% by weight of a special glycerol ester with high glycerol monooleate content, it is claimed to be very effective in preventing build-up of condensation inside food packages, which showing low tendency to plate-out. The recommended dosing level is 1.0%, and the system has good thermal stabiUty at processing temperatures, not impairing the clarity of the film.
18.10 Acoustic Insulation Development and use of additives to improve sound insulation properties of plastics compounds (especially required by the automotive industry) has been a strong theme of recent development. In the past, insulation theory has taken it that the most significant factor is mass, and by increasing it, insulation can be improved. This has led to use of heavy loadings of heavy fillers, such as barytes, but it goes diametrically against the other requirement of the automotive industry, reduction in weight. New technology has centred on diversion of some of the coherent molecular movement of acoustic pressure waves into random movement of heat, by molecular bonding within a material to increase internal friction (a small amount of water added to urethanes, for example, can disrupt internal bonding). This approach has been shown that a 1.02 mm thick flexible silicone rubber sheet can have greater attenuation than six inches of concrete and it may be applied to a wide range of materials. Experimental evidence suggests that the impedance of a material is more important than its mass. Mixing of materials with differing impedance (low and high) together in a matrix has demonstrated improvement in attenuation. Particle types tested ranged from hollow glass microspheres to iron and lead, and matrices included different types of silicone rubber, urethane, and epoxy resin. The phase of reflections from localized reflecting nodes (particles) is a function of the relationship of characteristic acoustic impedance of the particle, relative to the matrix material. A higher impedance particle will produce an in-phase reflection; a lower impedance will produce an out-of-phase reflection. Simultaneous in-phase and out-of-phase reflections within a particular locale greatly increase the possibility of phase cancellation, which is accomplished if both high- and low-impedance particle types are mixed together in a matrix material, or if two or more particle types with merely different acoustic impedance characteristics are combined. When two or more particle types are mixed into a matrix material base in the correct proportions, a synergistic effect
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causes the compound to have more acoustical attenuation than the sum of the components. Table 18.1 Acoustic properties of some commonly used materials Material
Density (kgm-^)
Velocity of sound (ms"^)
Impedance (ZinRayls)
Tungsten carbide Nickel, unmagnetized Iron, electrolytic Steel, mild Copper, annealed Brass(70%Cu, 30%Zn) Zinc, rolled Lead, annealed Glass, borosilicate Magnesium, annealed Marble, ground Acrylic Nylon 66 Polystyrene Rubber, polychloroprene Polyethylene Paraffin Cork flour Air, dry Hydrogen
13 800 8850 7900 7850 8930 8600 7100 11 400 2320 1740 2600 1180 1110 12 060 1330 900 900 250 1293 0.0899
6655 5480 5950 5960 4760 4700 4210 2160 5640 5770 3810 2680 2620 2350 1600 19 50 1300 500 331.45 1284
9.18x10^ 4.85x10^ 4.70x10^ 4.68x10^ 4.25x10^ 4.04x10^ 2.99x10^ 2.46x10^ 1.31x10^ 1.00x10^ 9.91x10^ 3.16x10^^ 2.91x10^ 2.49x10^^ 2.13x10^ 1.76x10^^ 1.17x10^^ 1.25x10^ 4.29x10^ 1.15x10^
Source: Modern Plastics International
18.11 Surfactants^ Foam Control Additives
Surfactants are used, especially in water-based formulations, to improve wetting, dispersion, slip and mar properties and defoaming. The group includes ethoxylated products, acetylenic alcohols and diols and proprietary additives. A new near-zero VOC nonionic wetting agent, said to be ideal for highperformance water-borne applications, is an acetylenic glycol-based material (Dynol 604, Air Products). It has the ability to reduce both equilibrium and dynamic surface tension to a degree not found in other surfactant chemistries, and its property mix allows use in difficult-to-wet substrates requiring good flow and levelling under various application conditions. Foaming can often be a serious problem in production and processing of polymer dispersions and latices, and silicone-based control systems have been developed to counter this effect. A range of products is available, giving choice of an appropriate grade to achieve high antifoam efficiency and/or high compatibility with specific products. Some foam control systems conform to the guidelines of the US Food and Drug Administration (FDA) and the German Health Office (BGA), for use in products, such as coated and printed packaging materials, which come into contact with foodstuffs.
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Two developments have been reported (by Wacker Chemie) supplementing its range of foam-control systems: Silicone Antifoam Emulsions SE 84 and SE 85. Based on organically modified silicone fluids, they reduce or prevent flow defects in polymer films. Air Products' Surfynol CT-324 is a pigment grind aid for high-solids coatings, providing pigment wetting and dispersion, dispersion/viscosity stability and low foam generation. Surfynol DF-62 is liquid 100% active ether-modified silicone defoamer, giving knockdown defoaming and long-term anti-foaming. Non-hydrolysable silicone surfactants (for Asian PU foam producers) are Dabco DC2583 and DCS 188, respectively reducing surface skin and producing open-cell foam at low mould temperatures, and producing fine even-cell structure and improved emulsification in flexible slabstock systems. A nucleating agent for PS foam A 27608 (Polycom Huntsman) improves cell uniformity, for FDA compliance: a natural talc-filled nucleating agent A 2 7678 is recommended for fine cell PS foam, GP and high impact grades. To minimize air entrapment in plastisol manufacture and application, promoting faster air release and quicker de-gassing under vacuum, methyl alkyl polysiloxane and silicone-free compounds of polyalkylane derivatives are used. Addition should not exceed 0.5 phr or 0.2-1.0% depending on plastisol formulation.
18.12 Mould Treatment Agents
Although not strictly additives, agents for cleaning and maintenance of moulds are important, and the following notes may therefore be helpful. Pulisol-9 (WIZ chemicals) is an effective solvent for cleaning moulds, metals, and similar articles. A blend of high activity and penetration solvents, which is neutral and evaporates slowly, it is a transparent liquid which can remove traces of polyurethanes, polyesters, epoxy and phenolic resins, as well as release agents, waxes, rubbers, and fats. The flash point is 31°C. The cleaner is used undiluted and applied with a cloth or brush, left to act for a few minutes and then wiped with a clean, absorbent cloth. For used moulds, more than one application may be necessary; for new moulds, one application is sufficient. Protective gloves should be worn. Wilax (also from WIZ chemicals) is a mould sealant and conditioner in paste form, for use with metal and glass fibre-reinforced resin moulds. It deals efficiently with porous or rough areas of the mould surface and gives moulded parts a glass finish, making release easier. A water-based emulsion of high molecular weight resins with small quantities of solvents, it is a non-flammable cream white paste. It can be applied after the mould has been cleaned, using a clean cloth and allowing drying for a few minutes before polishing with a soft cloth. An external release agent can then be applied. The whole operation should be repeated whenever the mould is polished or washed.
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CHAPTER 19 Other Types of Additive: Additives for Rubber The rubber industry was the original user of additives, and much of current technology for plastics - both chemicals and equipment - derives from compounding rubber. This chapter gives a brief overview. Classically, rubber is a thermosetting polymer, which requires curing (crosslinking), in a reaction which must be controlled (by initiators, accelerators, retarders, and other agents). The discovery that sulphur-based compounds initiated the reaction was fundamental. The rubber compound also requires pigmentation (leading to the discovery that carbon black could also act as a reinforcement), stabilization (against heat in processing and application, weathering and ozone), plasticizing (to improve processability) and extension (by means of low-cost fillers). Experience in compounding rubber established many of the principles of compounding plastics (especially PVC), in particular the mechanism of interface adhesion between polymer matrix and particulate and fibrous additives, and the process of compounding materials of differing size, shape, and chemical composition. Rubber compounds are very elaborate, in which the rubber component often functions mainly as a binder for the additives. These may include: process aids (peptizers, plasticizers, softeners and extenders, tackifiers); accelerators; accelerator activators; curing agents; anti-degradants fillers; colorants; and other additives (retarders, blowing agents). Reinforcements, such as natural or synthetic fibres or fabrics and steel wires also play a key role in manufacturing of rubber products, but it is normal to mix the compound first and then lay it up in the 'green' state together with the reinforcement, before moulding and curing the whole in a press or by passing it through an extruder.
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Sulphur curing takes place at about 140°C - but, even with a high dosage o sulphur (8-10 phr) this would take up to eight hours if sulphur alone were used. Addition of metal oxides, such as zinc, calcium, magnesium, or lead will reduc cure time at about the same dosage level. Accelerators, such as aniUne and i derivatives, are therefore used to increase still more the speed of curing an reduce the dosage of sulphur. Curing of rubbers is also aided by peroxides, metal oxides, amines, a^ derivatives and oximes, and other agents. High-energy radiation is also used, with appropriate chemicals. Plasticizers can be used as a processing aid to give particular properties vulcanizates. Processing can be improved by lowering mixing viscosity* improving mouldability and ease of calendering, improving filler uptake a n d increasing tackiness of the compound. Plasticizers can also affect hardness a n d modulus, increase elasticity of the vulcanizate or low-temperature flexibilit^y' improve flame retardant properties, and reduce smoke density in the event of i^^^ The compounding and moulding process is largely controlled by the chemi<-' a l additives employed, particularly with anti-oxidants and anti-scorch agents ^^^ Table 19.1 Additives used in rubber compounding Typical chemicals used
Additive
Function
Peptizers
Chemically assist breakdown Thiobenzoate,zinc-2-benzamidothiophenate, of rubber chains, to increase thio-p-naphthol efficiency of mastication
Processing aids
Soften and tackify rubber, for easy uniform mixing
Pine tar, mineral oil, wax, factice, coumarone-indene resins, petroleum resins, high styrene resins, phenolic resins
Plasticizers
Plasticizing, tackifying
Esters: phthalates, phosphates. Polymerizable: ethylene glycol dimethacrylate
Fillers: non-black
Mainly for cost reduction; reinforcement from (inely ground fillers
Non-black: china clay, whiting, magnesium carbonate, hydrated alumina, anhydrous/hydrated silicas (slate powder, talc, French chalk)
Fillers: black
Improved modulus, tear strength, abrasion resistance, hardness; may also assist cure
Carbon black (mainly from furnace process)
Anti-degradants Protection from attack by oxygen and ozone
Staining (amines): phenyl naphthylamines. 4,4-dialkyl or dialkoxydiphenyl-amines, N,N-dialkyl or diaryl-p-phenylenediamines; staining (phenols): styrenated phenols, substituted phenols, a- or p-bridged substituted phenols
Vulcanizing agents
Accelerators: guanidines, thiazoles, sulphenamides, dithiocarbamates, thiuram sulphides, xanthates, aldehydeamines; retarders: phthalic anhydride, N-nitroso diphenylamine; activators: zinc oxide/stearic acid
Curing, cross-linking: control of reaction to achieve balance of optimum properties without scorch, in economic time
Source: Based on 'Polymer Science andTechnology of Plastics and Rubbers'
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233
prevent thermal decomposition. Adhesion promoters are used to improve the bonding with reinforcement (particularly steel wire). To protect the cured rubber product during its lifetime, other additives are introduced into the compound to confer resistance to ozone, ultraviolet, and internal heat build-up (hysteresis) as the compound is stressed. A vital part of the compound is carbon black, which is used in rubber for its performance as a reinforcement, rather than for pigmentation. The compound is mixed, usually in a sequence of operations, in open or closed roller mills, and the sequence in which the additives are introduced is critical to good mixing, to bring them into the mix at a stage best-suited to the physical and chemical structure of each additive. Mixing may be in batches or continuous, depending on the compound and the application. It is normal to store compounds in their uncured state (for ageing as well as production requirements), requiring further additives.
19.1 Guidance on Safety
A guide to health and safety in the rubber industry is presented in the Code of Practice of the British Rubber Manufacturers' Association (BRMA) Toxicity and Safe Handling of Rubber Chemicals, now in its fourth edition. A combined work with Rapra Technology, the book contains updated information on hundreds of different rubber chemicals, with new data from manufacturers and suppliers and from standard sources of health and safety data. Many rubber chemicals are examined individually in the form of abbreviated safety data sheets. They are listed under their categories of use: reinforcing agents and fillers, accelerators and retarders, vulcanizing agents, antidegradants, organic peroxides, peptizers and processing aids, ester plasticizers, blowing agents, bonding agents, latex auxiliaries, pigments, and miscellaneous chemicals. Each chemical is given a data sheet including trade names, suppliers, physical data, fire hazards (including explosion risk), regulatory labelling, health hazards, emergency first aid and food contact listings (FDA and BgVV). New in this edition is the addition of CAS and EINECS numbers, to aid identification of materials. The book includes an introduction to the regulations governing the labelling and use of chemicals, together with definitions of toxicity, carcinogenicity, mutagenicity, and effects on reproduction.
19.2 New Developments 79.2.7 S/7/ca
An important driving force for new development is the automotive industry, and particularly the possibility that minerals such as silica will help to improve the fuel efficiency of tyres without the usual penalty of a trade-off in reduced grip in
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wet conditions. New technology has been growing rapidly in this field, suggesting that an ultimate aim must be to design and develop novel polymers that can provide a wet skid performance comparable with silica but without the need for it. This will call for a precise analysis of the phenomena that occur between the road surface and silica compounded rubber, and then incorporation of this functionality into the polymer itself. Although silica resembles carbon black in its particle morphology, the surface properties are very different. Silica is covered with silanol groups, which means that it has a poorer affinity with polymers than has carbon black, and this makes it difficult to obtain satisfactory reinforcement. It is therefore no match for carbon black in properties related to reinforcement, such as rupture strength and wear resistance, and this has been one major target of developers. The problem can essentially be solved by compounding with silane coupling agents, which chemically bond the polymer to the surface of the silica particle but, as these contain sulphur atoms, they may often cause processing problems due to scorching when the processing temperature is raised. Moreover, the coupling agents are expensive and have to be used in large quantities, so raising the cost of the compound. The tyre and synthetic rubber industries have responded to this challenge by developing technology for the addition of a silica particle bonding function to the rubber polymer, to allow direct bonding or other interaction between a silica filler and polymers without recourse to coupling agents. Recent approaches have centred on modification (by amine or amide, alkoxysilane, amine plus alkoxysilane, and epoxy) and compounding (assurance of reinforcement with polymer and compounding agents). Amine or amide modification involves coupling the anionic polymer chains with a tertiary amine to obtain tread rubber compositions that meet tyre requirements for wet skid, roUing and wear resistance. Heat emission and wear resistance can be further improved by quaternizing the tertiary amino groups. Alkoxysilane termination forms new bonds between the silicon of the alkoxysilane and the carbon polymer atoms in the polymer end group. Wear resistance is improved by about 50% and tensile strength is increased by some 30%. Further developments aim to maximize the effect by reacting an organoUthium compound with a polymer in the presence of an alkali metal alkoxide, producing a polymer in which the main chain has been metallated with a plurality of lithium atoms, and then attaching a plurality of alkoxysilane molecules to the chain. Amine plus alkoxysilane, from modification at one end of the polymer chain only, opens the way to modification at both ends, by the amine and alkoxysilane respectively, so achieving an acid/base reaction and alkoxy reaction with silica simultaneously and with the same polymer. An improvement of nearly twofold in tensile strength, wear resistance and heat emission can be achieved. Active anions have been used so far with epoxies, but epoxidation can be obtained by other means, as long as the polymer contains double bonds. It is possible to react an epoxidized conjugated diene polymer with a white filler, forming chemical bonds between rubber and silica without using a coupling
other Types of Additive: Additives for Rubber
235
agent, which is claimed to facilitate dispersion and afford better properties. Examples are markedly superior in strength, heat emission and wear resistance to unmodified examples. Copolymerization of a polar monomer with SBR, chiefly in production of emulsion-polymerized SBR, is also being researched. In this approach the copolymer is combined with zinc white and fatty acid salts as compounding agents. This approach is claimed to prevent poor dispersion of the silica and to improve processability, and also to give a substantial improvement in heat emission, tensile strength and wear resistance. In parallel with these developments there has been a more effective method of measurement of reinforcement. Methods currently used to determine this require the filler to be comminuted by means of ultrasound, but this causes severe degradation of the agglomerates in carbon blacks, and also distorts the distribution of silicas. An alternative method has been developed using transmission electronic microscopy, in which the filler morphology retained is similar to that obtained in the incorporation process. As well as improvement of mixing and processing of filler-reinforced compounds today, the researchers believe it will be possible in future to use the AIBN procedure to develop new fillers more selectively.
This Page Intentionally Left Blank
CHAPTER 20 Other Types of Additive: Additives for Recycling The arrival of recycling as a system increasingly demanded by legislation could open up significant markets for additives (a) to enhance the properties of plastics recovered from waste and also (b) additives which will facilitate the recycling process, particularly for providing fast and effective identification of types of plastics.
Table 20.1 At a glance: additives for recycling Function
Treatment of waste plastics (especially post-consumer/mixed/ contaminated waste); re-stabilizing (mainly heat), restoring properties (e.g. impact); compatibilizing differing ingredients
Properties affected
Processability; viscosity; heat stability; mechanical properties; ageing properties
Materials/characteristics
Heat stabilizers/anti-oxidants; impact modiiiers; pigments, fillers, reinforcements
Disadvantages
No disadvantages yet reported
New developments
Technology is still very new: possible development of identification 'tracer' additives
20.1 Stabilizing^ Re-stabilizing
In principle, it is reasonable to assume that recycled industrial scrap may be regarded as virgin polymer from the point of view of stabilization, and should therefore be re-stabilized in the same way as the original material, prior to re-processing. This holds good also for stabilization of post-consumer recycled plastics but, in this case, other factors should also be considered, such as degree of degradation, amount of residual stabilizers and extent of contamination. Establishment of a well-stabilized compound in the first place can, however, have only a beneficial effect. Combination of a hindered phenol with a hydrolysis-resistant phosphite has been shown to have a spectacular effect on
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polypropylene, with only 0.05% addition of phosphite exhibiting good inhibition of degradation during up to five extrusion passes. The phosphite not only protects the polymer but also protects and conserves other stabilizers that are important for long-term stabilization, such as hindered phenols. However, a key problem when reprocessing post-consumer waste is the lack of knowledge of the type of materials used in the original formulation (but there are analytical techniques for establishing and identifying these). Depending on the concentration of active stabilizers in the waste material, and the long-term requirements for thermal stability, it may be necessary to re-stabilize the reprocessed compound. Good results have been demonstrated (for example, with HDPE bottle waste) in re-stabilizing with 0.2-0.3% of a phenolic anti-oxidant blend. Several companies have been looking at the potential of additives in recycling plastics as materials by physical reprocessing ('mechanical recycling'). Typical is Ciba Geigy which, in 1990, formed a specialized group based on its Marienberg subsidiary. It has already developed stabilizer blends for commingled plastics (Recyclostab) and has a special project working on 'tracer' additives, which would help in automatic separation of different types of plastics. Another aspect is destabilization/degradation of plastics post-use, aiming at a degradation product that is in the domain of the basic raw materials (namely oil or monomers), for which it does not see an immediate solution.
20.2 Stabilizers Most manufacturers have added to their stabilizer ranges suitable formulations for recycled material. Akcros has developed calcium/zinc stabilizers containing a number of co-stabilizers in its Interlite range, for PVC flooring and profile recycling. Ciba Geigy's Irganox 245 anti-oxidant cuts (to 25%) the yellowing index of recycled PS yoghurt pots during ageing. Irgastab CZ 2000 calcium/zinc stabilizer at 2% addition reduces the yellowing index of PVC window profiles. A 4:1 blend of Irgafos 168 and Irganox 1010 at 0.3% addition aids PET to retain more of its intrinsic viscosity through repeated processing (up to five times). Work by Ciba-Geigy also shows that reactive additives and stabilizers (Recyclostab range) can improve ultimate elongation of material reclaimed from painted PP bumpers by a factor of three. Resistance to thermal degradation is doubled compared with straight reclaim. Rohm and Haas offers EXL 3600, an encapsulated rubber additive that can restore the melt strength of low molecular weight PC to about the same level as virgin. It can also improve notched Izod impact from less than 50 J m~^ (for normal recyclate) to about 300 J m~^ at 20% addition level. Electrical properties are virtually identical to virgin material. Quantum offers a Spectratech line of colorant and additive concentrates for recycling: the anti-oxidants boost heat stability and improve the oxidation resistance of the recyclate.
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20.3 Improvement of Properties 20.3.7 Fibres/compatibilizers/impact
modifiers
The properties of commodity and engineering thermoplastics can be boosted by compounding with mineral fibres and a special compatibilizer, report two Dutch companies, Bennet BV and Lapinus Fibres BV. Polyolefins (HDPE and PP copolymer) and poly amide 6 have been successfully upgraded with 35 and 25% respective addition of Rockfil fibres and Bennet compatibilizer. Tests in conjunction with injection moulder Heudijk Kunststoffen BV and masterbatch producer Curver Colour Department indicated that mechanical, stability and processability properties are improved, with improved heat distortion and FR performance, good surface finish and recyclability. In the PA6 compounds it was concluded that 25% increase in E modulus and 60% in notched impact strength (and better) could be obtained, while heat distortion temperature could be raised from 75 to 156.5°C by the addition of 20% fibre. The two companies plan to develop upgrades of other thermoplastics, both commodity and engineering, aiming specifically at tailoring certain properties prior to reinforcing. Bennet BV, Ede/Netherlands, is a member of the Danapak Group and Lapinus Fibres is part of Rockwool International. The fibre/ compatibilizer mix will be marketed under the name Rocknet by Lapinus Fibres BV (Roermond/Netherlands). Bennet also finds that addition of its BRC 200 compatibilizer to a mixed waste stream of equal parts of LDPE, LLDPE, HDPE, VLDPE, and PP homopolymer and copolymer boosted impact strength, to higher than the single components, in injection moulded parts. Compatibilizers containing branched ethylene, EVA, and elastomers, are added to scrap LDPE, HDPE, and PP to make drainage pipes. Dexco (Exxon/Dow) has developed styrenic block copolymers as compatibilizers, to improve impact strength. Vector SBS (not containing halide salts) gives better heat stability than conventional block copolymers due to absence of residual halides, which can lead to property degradation. It can boost ultimate elongation and impact strength of PS waste. GE Specialty Chemicals supplies Blendex 338 impact modifier to upgrade ABS, SAN,andPVC. Rohm and Haas has targeted waste PET, which has low viscosity and poor impact strength. Dosing with EXL 5375 additive at about 20% restores properties to virgin levels. DuPont Fusabond compatibilizers (in a number of grades, mainly based on maleic anhydride-grafted polyolefins) have been used in Finland with multilayer film waste, allowing the recycler to reprocess it as video film cassettes or bottles.
20.4 Desiccants
Use of desiccant additives based on calcium oxide can have important costeffective benefits in processing plastics and rubber, eliminating the need for
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pre-drying and avoiding porosity and metal corrosion problems. The additives are also valuable in processing recycled materials, reports Croxton and Garry. As little as 0.02% moisture content can cause problems in mouldings or sheet materials. C and G supplies a range of calcium oxide desiccants which operate by exothermic reaction with water, producing calcium hydroxide as an inert filler in the moulding with a decomposition point of about 530°C - well above the processing and service temperatures of both plastics and rubbers. The Fluorox grades differ mainly in particle size; Garosorb products are either damped powders or pourable pastes which are readily dispersed, while Multisperse E-CAO-80P is a non-dusting polymer-bound granular form. Reclaimed thermoplastics often contain significant amounts of water. Addition of calcium oxide (and some grades are able to scavenge up to 32% of their own weight in moisture) makes it possible to mould at only marginally extra cost. In inherently hygroscopic materials such as polyamides, calcium oxide may often avoid the use of prolonged oven drying. Moreover, fillers can import moisture into poly olefin compounds that can contain as much as 25%, leading to porosity in mouldings.
20.5 PE/PVC Compatibilizing
PVC has for long been the main material for cable sheathing but, with higher specifications and pressure from environmental lobbies, the use of cross-linked polyethylenes has been increasing - presenting problems when it comes to recycling. A compatibilizer technology has been developed by Sumitomo Electric Industries for recycling this polymer sheathing. Rather than having to separate mixtures of polyvinyl chloride and polyethylene, as has been necessary until now, it is claimed that the new technology can be used to produce a polymer 'alloy' of the two materials, that can be reused as cable sheathing.
20.6 Melt Flow/Viscosity Modification
A peroxide concentrate for polypropylene has been developed as an alternative to liquid peroxide for melt flow modification of recyclate and off-grade PP material by Polyvel. It is safe to touch, with 20% active peroxide level, which is constant until used. A high level of active peroxide is said to make the material very economical: a 1% loading can increase the melt flow rate of standard PP to over 150 g (10 min)"^. A further cost-reduction for plastics pipe is promised by Chemson, with continuing development of its technology in PVC stabilizers. The company reports that its additive systems for foamed core pipe production have reached a stage at which they will permit recyclate material to be incorporated, without any trade-off in terms of quality. The company suggests that, for a foamed core pipe plant with an output of about 350 kg h"^, the savings in materials costs could run to a six-digit amount during a year.
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241
Multi-layer technology for pipes has been widely accepted for extrusion of large diameter pipe for sewer ducts. Today, virtually no pipe of this type is produced without a core of foamed PVC between the inner and outer skins. The three-layer structure, in which the central core constitutes about 60% of the total material, reduces the weight of the pipe by about one-third, compared with conventional technology for production of a pipe of the same diameter. The blowing agent is nitrogen, directly metered into the machine as azodicarbonamide.
20.7 Additives for Identification of Plastics
Much interest has been expressed in the possibility of developing safe and reUable additive systems which could act as 'markers' in waste plastic products, reflecting X-ray or infra-red signals and triggering separation mechanism. There are major problems to be overcome, however, in developing a system that can operate on a fully commercial scale (for example, mounted over a conveyor belt and accurately scanning many tonnes of mixed plastics waste per hour). An organic marker system which can be added to a polymer molecule has been developed by Eastman Chemical. The company claims to have demonstrated the feasibility in the laboratory, but there is much more work needed to develop a commercial application. If successful, it is envisaged that such a marker would provide a relatively economical means of identification and therefore separation of different types of plastics, which could be operated on a continuous industrial scale. The system is said to work both with transparent and opaque plastics. Chlorine and bromine components, heavy metals and various types of fillers can be identified in plastics, by means of a number of technologies being developed for identification of plastics in post-consumer waste. If the process can be made rapid enough it will be one of the keys to economical recycling of plastics. Generally, agencies and companies concerned with recycling still have to fall back on manual sorting, which costs an estimated DM0.6-1.2 kg~^ - with the result that it is difficult to produce a recyclate material that is pure enough to command a respectable price. Additives can add problems to recycling of plastics, but they could also be one of the means of identification, which might simplify the process. The vital factor is that any method of automatic selection (and separation) must be able to operate on a large scale, over large volumes of plastics waste, probably conveyorized. Elements of high atomic weight, such as chlorine and bromine can be identified rapidly by means of X-ray fluorescence. This technique could be used to separate compounds containing chlorinated or brominated flame retardants, but to date it has been used in practice only for separating PVC bottles from other plastics. Transparent bottles can be separated from opaque green-coloured bottles by detecting the difference in transparency with the aid of transmission sensors which determine the transmission of waves of a specific length, so making it possible to separate PET from HPDE.
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Using a combination of X-ray and transmission detectors greatly extends the scope of a system, enabling it to deal with the most common types of plastics entering the waste stream, from retail packaging sources: polyethylene, polypropylene, PET, polystyrene, and PVC. Rapid spectroscopic methods include (a) analysing the whole polymer molecule without altering composition - optical, near-infra-red (NIR), midinfra-red (MIR), Raman spectroscopy (FTR), and X-ray methods; and (b) using pyrolytic decomposition. With packaging, identification can be restricted to PE, PP, PVC, PS, and PET and, as each item weighs only a few grams, the system must be fully automatic and capable of handling large tonnages. For waste such as automobile parts, there is a wider mix of materials, often assembled. Disassembly is economically justified only if components weigh more than 100 g, and sorting is often best carried out manually. MIR and FTR spectrometry can be used. The only systems used on an industrial scale so far are believed to be based on X-ray and IR, mainly for bottles, since the high cost of PET providing an incentive. X-ray absorption systems are made by National Recovery Technologies, USA, and Giovani, Italy. X-ray fluorescence detectors are made by Magnetic Separation Systems (MSS) and Asoma Instruments, both of the USA. InstaUations have been used by the UK PVC recycling specialist Reprise, and also by Tecoplast, in Italy, and Micronyl-Wedeco, in France. Operating at a throughput of 1-2.4 tonnes per hour, they have been able to separate bottles made from PVC, PET, and HDPE. A combination of detectors in used in the MSS BottleSort system, using X-ray for PVC and an IR system (by Biihler, Germany) to separate PET, HDPE, PP, and PS, giving recyclate up to 99.8% purity. Such a system has been used since 1994 by Miiller Recycling, Switzerland. NIR systems are also used in many parts of the world, and a combination of NIR with a colour-identifying system has been developed by Binder, Austria, with Massen Machine Vision Systems, offering simultaneous sorting of up to 10 fractions at 1200 kg h ~ \ to 99.9% accuracy. Autosort, designed by Elopak, Norway and used in Germany, uses NIR, and handles 2 tonnes per hour. A basic drawback with the NIR method is that it is not well adapted to the detection of plastics containing a large amount of fillers, and/or certain types of flame retardants, or to compounds that are grey or black. This type of waste can be identified, however, by infra-red radiation in the socalled IT radiation region, which relies on the fact that the adsorption of IR radiation by carbon black is significantly lower, allowing measurements in reflected Ught to be made. Other spectrometry technologies include sliding spark (AGR and the University of Duisberg, Germany), identifying a wide range of plastics and additives, and laser-induced emission (LIESA), by Krupp, the University of Kaiserslautern, and BASF Magnetics. The measurement is carried out by a special probe attached to a spectrometer, which is applied to the surface of the material. An electrical discharge between two electrodes causes momentary evaporation of a small fragment of the
Table 20.2 Forms of waste, processing lines and potential recycled products Waste
Form of waste Film
Pure material/solid PS. PE. PP ABS, PET, etc. PVC rigid PVC flexible Foamed PE Foamed PS Mixed PS. PE. PP Mixed ABS. PET, etc.
Source: Hrrstorfl
x
x
Fibre
x -
-
x
x x x
-
State of waste Particles
Protile pipe
Slight
Heavy
Wood
x
-
-
-
x
x
x
-
-
-
X
-
x
-
-
X
X
-
-
-
x x x -
x
-
-
x x
-
-
-
-
x
x
x x
-
x -
x
-
x
x x
-
x x
x x
-
Contaminated metal
x x x -
x x
x x
-
Pure
-
Machine (BerstorFf)
Product
R-AE/G R-ZE/G R-KE/H R-CE/G R-KE/G
Pellets Powder Semi-finished Products Ground stock Pellets
R-KEIH x
Pellets, powder Semi-finished products
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compound and gaseous products specific to the material are emitted. The analysing system coupled to the spectrometer makes it possible to determine the chemical structure of the specimen and identify the material positively. The detection time is about one second, and the system can recognize plastics irrespective of their pigmentation, working with a wide range of thermoplastics, chlorinated and brominated polymers, heavy metal additives such as cadmium and lead, fillers such as whiting and talc and glass-fibre reinforcement. Laser-induced emission spectroscopy analysis (LIESA) is a similar technology, in which a beam of laser light is directed onto the surface of the specimen. This induces a short-lived hot plasma that comprises free electrons, excited atoms, and ions of very high electric charge. Laser light is also used in thermo-optical methods of identification, creating local heating on the specimen by directing a beam from a CO2 laser for a fraction of a second. Depending on the coefficient of absorption, thermal conductivity or heat capacity characteristic of the material, there are differing temperature distributions. The technique is being studied at the Laser Centre in Hanover, Germany and has been used successfully to date in the identification of polymers including polyamides, fluoropolymers, polycarbonates and acrylics, with detection at speeds greater than 0.1 seconds with moving objects. It is a particularly interesting technology, because the error of measurement is not affected by factors such as colouring, additives such as plasticizers, or the contamination of the surface. The automobile company Ford has developed, in conjunction with Southampton University, a hand-held instrument for identifying the basic types of polymers and additives, and the research agency PIRA is reported to be working on similar equipment, in conjunction with Bayer AG.
20.8 Equipment for Recycling
Depending on the state of the incoming waste, standard equipment can be used for reprocessing waste thermoplastics, following size reduction of the incoming products to a rough-chopped flake or granule that can be fed into an extruder/ compounder. Special equipment or modifications may be required where the waste stream is of mixed plastics, contaminated plastics (such as by oil, chemicals, foodstuffs or printing) or where non-plastics materials such as metal or wood cannot be separated. The preceding table suggests the suitability of equipment to various waste streams and conditions.
CHAPTER 21 Background Information: Equipment - Mixings Compounding^ and Dosing
21.1 Incorporation of Additives
Additives are introduced into polymer compounds is by means of physical mixing, using a paddle-blade mixer or roll calender, for powdered materials, or a compounding extruder, for thermoplastic melts. The key criteria are the type and nature of additive and the point at which it should be introduced, the degree of precision in measurement of polymer/additive ratios and the work that has to be carried out to ensure good homogeneous mixing, with even dispersion of the additive. Modern polymer compounds, with many different types of additive, present strong challenges to the designers of the system. Other equipment, particularly dosing systems, can be mounted on the extruder, and is increasingly used for precise direct metering of very small quantities of additives such as liquid colour systems. The last few years have seen major developments in more efficient design of mixers and extruders. There has also been important development on the materials side, to make additives easier and more suitable for compounding, opening up to smaller compounders the possibility of making special compounds. This will be mainly to offer a range of colours, while only needing to hold stocks of natural material, or to add or boost specific properties, such as UV stability, anti-static properties or flame retardancy. To facilitate in-plant compounding, most suppliers have developed systems that efficiently and reproducibly deliver a controlled package of additives to a compound, using either a specialized concentrate or a masterbatch formulation. Compounding as a separate industry was originally devoted mainly to the addition of colouring, especially for special colour matches. This gradually developed to skill in short-run production, with high efficiency in distribution, to meet the demand from plastics processors for small volumes of special grades. Many independent compounders now operate under franchise from polymer producers, while also marketing their own formulations. From this base, compounders have extended their activities to production of technical compounds, incorporating special additives and chopped glass-fibre
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reinforcement. Modern compounding equipment is based mainly on extrusion mixing and incorporates a number of points at which other materials can be introduced, at various stages in the process, possibly including satellite extruders to produce blends. In the most sophisticated operations, there are facilities for reactive compounding, in which additives and other polymers are chemically reacted with the main polymer system. Modern compounding may involve the introduction of several different ingredients and, for all equipment, the crucial aspect is to produce homogeneous mixing, often with very precise measurement of the various components. Most suppliers of compounds include a wide choice of such packages in their standard range and can readily formulate customized systems, to meet a specific requirement. Some of the polymer manufacturers have also made available advanced additive delivery systems that they have often developed originally for their own use.
21.2 Mixing Thermosets
Thermosets are mainly viscous liquid resins, presenting their own compounding requirements. Liquid mixing systems of varying degrees, from the most basic to highly sophisticated are used, depending on the type of resin, additives, and volume output required. The amount of additive by weight which can be incorporated will depend on the particle size, density and oil absorption properties. For example, addition of porous high oil absorption fillers (such as diatomaceous silicas) and chopped glass can greatly increase the viscosity of a resin system at low filler loadings of only 1-50 phr. Medium weight granular fillers, such as powdered aluminium and alumina may be used at loadings of up to 200 phr. The non-porous lower oil absorption fillers, such as aluminium oxide, silica and calcium carbonates can be incorporated at levels of 700-800 phr without making the formulation unworkable. Loadings can be increased by adding a diluent, but this may not always be desirable, as the diluent may detract from other desired properties. Organotitanates can be added to improve filler wetting, enabling higher loadings at the same viscosity. Fine particles are easier to incorporate and there is a lesser tendency for them to settle. Coarse and heavy fillers will settle and *cake' on standing, but this may be countered by adding lightweight fillers such as the colloidal silica compounds. It goes without saying that the crucial aspect is to obtain a completely homogeneous mixture of polymer and additive. This is a difficult target, bearing in mind the viscosity of the polymer and the often particulate nature of the additive. To make things easier, additive producers have and still improve their products to facilitate mixing. Pre-heating fillers before mixing with polymer or resin can improve the mixing rate, reduce energy consumption in processing, reduce wear on equipment and improve product quality, it is reported. Addition of fillers cold has a number of
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247
disadvantages, not the least of which is the difficulty of maintaining consistent mixing cycles or production rates during seasonal changes in temperature or humidity, especially if the filler is stored out of doors. During winter, unheated fillers may have greater levels of condensed and absorbed surface moisture than in the summer and can require as much as 1 5 20% longer mixing time. Moreover, since mixing relies heavily on frictional shear heating to achieve plasticizing and dispersion, there can be excessive wear on compounding equipment blades, screws, barrels, and walls. High friction can also break down the aspect ratio of the filler, degrading properties of the finished compound.
21.3 Mixing Thermoplastics
Additives can be introduced at various stages in production and moulding of a thermoplastics compound, depending on the type and form of the additive. Comonomers may be also regarded as additives and introduced during polymerization, depending on the polymer matrix, but most additives conferring special properties, such as reinforcement, colouring or modification, are added to the polymer matrix in a secondary compounding stage. Depending on volumes, this may be carried out by polymer producers themselves, in their own in-plant facilities, or under contract, or by independent compounding organizations. Large special-purpose extruders are used, designed for very efficient mixing with close control over temperature and shear rate, and high output. An important qualification is that the compounds are heat sensitive, calling for a closed system with accurate control over temperature. Regarding the latter, it should also be remembered that the shear action of compounding may produce its own heat, which must also be considered. 27.3.7 Dry mixers
The basic form of mixer operates on a batch process, using dry materials such as powders, or pastes. For the simplest work, a tumble mixer design has been used for many years, for addition of colour or mixing with masterbatch concentrate. More technical demands, however, have called for mixers normally using the Z-blade design, giving precise control over ingredients and times. This system is widely used in production of PVC compounds, which can be mixed in dry powder or paste form. In this sector, there has is always been an argument about whether it is better for the processor to mix compounds in-house, or buy in compounds ready-made. The answer lies very much in the type and volume of work, and particularly in the cost of handling hazardous substances with the safety and consistency that is demanded in processing today. In PVC processing, volume is a clear criterion, and it is unusual to be a large processor without having in-house mixing facilities. Centrally made PVC compounds are one of the strongest growth sectors of the business, and all resin producers have invested strongly in this sector.
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An alternative design employs one or two kneading rotors, working inside a fixed stator housing. This can be of various sizes, and offers considerable scope regarding the geometry of the rotor flights and stator walls, to optimize the mixing process. Continuous PVC compounding is claimed by Colortronic for its Novablend system with automated gravimetric blender and liquid doser, with a specially designed horizontal mixing screw and a high-speed Waeschle mixing turbine. Precision blends and flexible formulations can be produced with greater accuracy and at lower cost. Unlike conventional systems, the system creates sufficient nominal friction to raise the temperature of the PVC powder high enough to absorb liquid stabilizers for rigid PVC. A mixer particularly suited to free-flowing powders, has been introduced by Hosokawa Mikron BV. Operating by the use of shear forces, the Cyclomix is conical and is filled to about 50% of its capacity. A central high-speed rotating shaft is driven from the mixer cover (so removing seals and bearings from the area of the product). Paddle-shaped mixing elements rotate close to the inner wall and their high speed plus the conical shape of the mixing vessel transport the product from the bottom of the chamber to the top, intermixing the particles by friction against the wall. On reaching the top, the product flows down again into the centre. Special features of the Cyclomix are: fast intensive mixing, widespread applications, self-emptying, no seals and bearings in the product zone and good control over the product temperature. A feeder unit with flexible polyurethane walls has been developed by Brabender Technologic, which offers high reliability particularly for poorly flowing ingredients. The Flex-Wall uses massage paddles instead of agitators and can be employed as a 'stand alone' volumetric feeder or as a loss-in-weight feeder in conjunction with a Brabender scale. Removal of the screw tube and dismounting of the screw is rapid and, if necessary, the flexible hopper can easily be removed for further dry or wet cleaning. The feeder is particularly suited to systems where processes have to be interchanged frequently, where the entire hopper can be exchanged together with its contents, without the need for emptying. 27.3.2 Calendering Calendering is a method of mixing in which polymer and additives are introduced into a stack of rollers, which apply work and heat and progressively reduce the thickness of the mix to that of sheet or film, with the facility also of adding an embossed surface. The equipment, which has been 'borrowed' from the rubber industry, is usually large and costly, but laboratory-scale systems are also available, for small-scale testing of compounds and formulae. 27.3.3 Extrusion compounding Extrusion compounding is the main method of compounding thermoplastics. The base polymer is fed continuously by means of a hopper into a plasticizing
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chamber or barrel, in which it is worked by means of a rotating Archimedes-type screw, while heat is applied by elements in the barrel and screw, as required. At appropriate locations there are ports through which additives can be fed as required. Glass fibre, for example, requires specific handUng. Pigments may be added on the shop floor (enabling raw materials stocks to be rationalized to natural material only), but there may be potential health hazards. When the required homogeneous mix has been achieved, the output of the machine is extruded as strands of polymer melt, which are cooled in a water bath and are chopped into free-flowing granules, for packaging and shipment. As the geometry of the granule has an important influence on processing properties, the design and technology of the granulating stage is critical. The system offers great flexibility in the speed and geometry of the screw and the number and location of heating elements. Single or co-rotating twin-screw systems are used. Much has been learnt during the past few years and several new machine designs have been introduced to the market. There is also a trend now towards modular construction, giving compounders a large degree of flexibility in rapidly modifying a machine for a special grade. 213.4 Compounding
mineral fillers
With the increasing use of mineral fillers to improve mechanical properties of a compound, the demands on the compounding extruder have risen. Fillers can be added in concentrations ranging from 20 to 80% by weight, meaning that it is not possible to have a single standard feed system. They can be fed at different positions through one of a number of side feeders. All fillers contain air and moisture, which must be removed during compounding, along with other volatiles. Most machines therefore have at least one degassing zone in the melt section, downstream from the filler addition, usually operating under vacuum. 27.3.5 Fine talc masterbatch
Among recent compounding developments by Buss Compounding Systems is production of masterbatch concentrates using fine grades of talc, especially for automobile components, where the industry is looking for a system capable of dosing a talc masterbatch directly into a base polymer, at the injection moulding machine. This calls for fine talc masterbatches at 70-80% loadings, but fine talc is difficult to compound due to the low bulk density of the powder. A Buss MKS 70 mm 20L/D machine was adapted, with the kneading chamber configured to permit vertical feeding of polymer and filler in the first barrel module, and side-feeding of filler and vacuum degassing downstream. A split feed technique was used, introducing one-third of the talc together with the polymer at the first inlet and the rest downstream, directly into the melt. The interaction between the fixed pins and reciprocating screw flights in the Buss kneader, giving multiple mixing as the material moves down the chamber, provides a high degree of surface renewal and optimum wetting and degassing. Samples at 70% loading have been successfully produced.
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213.6 Single- and twin-screw
extruders
Two basic designs of extruder are in use today, equipped with one or two screws. The single-screw design is generally considered a more simple but rugged machine, with good endurance, and is best suited for long continuous runs of the same formulation. The twin-screw design, however, is more complex but gives greater flexibility in mixing special compounds. In polymer mixing, a distinction can be made between distributive and dispersive mixing. The former method aims to improve the spatial distribution of the components, without cohesive resistance playing a role. It is also called simple or extensive mixing. Dispersive mixing has to overcome cohesive resistances to achieve finer levels of dispersion. It is also called intensive mixing. Dispersive mixing is the more difficult and, in single-screw extruders, is thought to be inefficient because the mixing is achieved primarily in shear and the compound is exposed to the mixing action of the high stress region only once. Twin-screw extruders provide a uniform and reliable feed of the polymer and mineral fillers, with effective degassing in the melt zone. There must be complete wetting of the filler by the polymer melt and good dispersive mixing of the fillers into the melt, while the heat and shear history of the matrix is reduced to a minimum, to avoid degradation. Specialized screw kneaders have been developed, based on co-rotating twin-screw machines in single- or two-stage versions. The screw speed does not influence the physical properties, provided that there is constant torque utilization. Additionally, the number of filler additions has only a negligible effect, giving the compounder good flexibility and permitting adjustment of rate to suit market demands. While most of the development work has been carried out on filled polypropylene, Werner and Pfleiderer has also been working with polyethylene butylate, nylon 6 and 66, and ABS. The company's MEGAcompounder is a twinscrew design that is being produced with capacity to supply extra torque, making it possible to raise the screw speed from 400 to 500 rpm, so allowing an increase of about 50% in throughput. Higher speeds have been run with nylon without adversely affecting the properties. Krupp Werner & Pfleiderer has a number of new developments. The ZSK 50 Mc filling a gap in the range, with 2 5 0 - 1 0 0 0 kg h~^ output, has a new design concept with tie-rod tensioning of the block barrels and three-point support for base-frame and gearbox. The biggest yet co-rotating twin-screw (ZSK 380 Mc), with a screw diameter of 380 mm and output up to 75 tonnes per hour, it uses a special drive concept and new measuring devices can examine the entire bore length within half a day, to identify barrel wear without dismantling. The machine also features improvement in internal mixers: an HESC (high-efficiency supercooling) four-wing rotor, interchangeable with existing rotors, and a PES 5 contour-milled rotors for better quality and higher output with hydraulic feed ram replacing pneumatic ram (for energy savings and reproducibility) with simpler cooling via the piston rod. A new disposable mixer that is claimed to reduce costs of production of reactive resins has been developed by Sulzer Chemtech, Switzerland. The design
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is based on a unique arrangement of mixing baffles, giving a mixer with a low pressure drop that can achieve the required degree of mixing with only half the volume needed by conventional spiral mixers. The degree of mixing can be predicted mathematically, leading to consistently high quality. The advantages add up (it is claimed) to lower waste, improved use of material, and lower cost. Sulzer also claims a reduction of as much as 40% in the use of masterbatch by fitting a new design of static mixer to the nozzle of an injection moulding machine. The mixer improves the homogeneity of the melt, allowing reductions to be made in use of pigment without the usual penalty of streaks appearing in the moulded part. Pay-back times of 4 - 6 weeks are not unusual, claims the manufacturer, arguing that companies often use more masterbatch than is necessary, to compensate for poor mixing. In addition to improving the use of masterbatch, the mixer can be used to reduce cycle times, to increase the amount of regrind that can be added to the mix and to reduce overall scrap rates. It is designed to produce a very low pressure drop and, because of this, can be used with shear-sensitive materials such as PET. 213.7 Adjustable screw
geometry
In twin-screw extruders, the elongational flow, which is the mixing action created, achieves more efficient dispersive mixing, but the main mixing action occurs not in the intermeshing region but in the region between the pushing flight flank and the extruder barrel. Twin-screw machines make good dispersive mixers because this space is wedge-shaped, creating elongational flow as the mix is forced through the flight clearance. Developments by Rauwendaal Extrusion Engineering, force the material through the high-stress regions several times, creating elongational flow in two ways. The company's CRD mixer uses a slanted pushing flight flank, to stretch the material as it is forced through the flight clearance, and the flanks have tapered slots, which serve to increase distributive as well as dispersive mixing. The same company has also introduced an adjustable grooved feed extruder, which overcomes some of the disadvantages of the existing non-adjustable design. Grooved feed machines have been in use since the 1960s, giving higher throughput, better stability and the ability to process very high molecular weight polymers, but with disadvantages in higher load on the motor, greater likelihood of wear and high pressure in the grooved region. APV has developed extruders with a segmented agitator system to process all types of plastics compounds. The machines have a 'clamshell' design of barrel that opens hydraulically, to give easy access for efficient cleaning or maintenance of screws. A new, segmented liner system allows rapid replacement of liners and reduced maintenance costs. Liner materials are selected to match the specified processing duty in each extruder zone. Melt temperature, specific energy input, and residence time can all be precisely controlled. High-torque or high-free-volume versions allow the machine specification to be matched to the requirement and an option of 1200 rpm drive maximizes output potentials and adds extra versatility to the capabilities of the Advanced Compounder.
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Figure 21.1. For better compounding efficiency, recent barrier screw designs by Davis-Standard include (top) DSB-V, with variable-pitch barrier flight, and DSB-V1, with a dual-barrier design and variable lead barrier flight. (Photograph: Davis-Standard)
21.4 Colour Dosing
Colour changes in seconds are claimed by Colortronic GmbH, for a low-rate gravimetric additive feeder, Graviblend S. It provides feed rates of 8 0 - 1 0 0 g h ~ \ according to bulk density, and is designed with quick-action clamps for the dosing hopper and screw on the micro ingredient feeding system, to allow the user to change dosing systems and make colour changes quickly and efficiently. Any cleaning required for the dosing hopper and screw can be carried out offline. The unit has been designed for continuous feeding of bulk material for applications where precise low feeding rates for granules are needed, such as fibre, cable, filament and tubing, and laboratory lines. Its construction and advanced technology brings optimization to low-rate-feeding applications, with compact construction for easy and quick installation. Low weight causes good mass resolution of the metered material and a special damping system offers reliable protection against mechanical disturbances such as vibrations. A significant improvement in accurate blending of ingredients in liquid colour dosing is claimed by Maguire Products, USA. The company has been working on liquid colour systems since its formation and, in 1996, it developed a system in which the colour was fed directly to the weigh chamber of a gravimetric blender. This differs from the conventional systems, which rely on either dosing the liquid colour directly into the feed throat of the extruder or moulding machine, or employ a process to pre-coat the plastic pellets with colour before they are dosed. The company has also developed new software for accurately controlling very small additions of highly concentrated ingredients, which are typically added at a rate of 1% or lower. It can also control the addition of poorly flowing waxy additives, such as blowing agents, and long glass fibre concentrates, where the geometry of the pellet may inhibit consistent flow. A liquid colorant metering system from Hanna Group offers a simple, clean and less expensive alternative to cleaning machinery and shop floors. It incorporates a three-way valve that temporarily diverts colorant from the moulding equipment to a special calibration section for weighing, keeping this
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operation separate. Normally liquid colorant tube sets are disposable, as part of the tubing wears out, sometimes after several weeks, as a result of being flattened by the peristaltic pump. The Hanna system, however, makes it possible for the processor to replace only the worn part. Offering a new level of user input and sophisticated programming techniques to increase productivity and profits, the latest version of the ProPalette colour formulation system by GretagMacbeth is designed specifically for the plastics, paint and coatings industries. For 'single-hit' colour matching at all levels of opacity, the latest version (which gives a seamless transition for existing users of the system) has database improvements which offer users considerable flexibility with data, as well as improvements to the user interface giving better efficiency. Innovative colour utilities are also provided, which streamline the analysis of the data and improve the productivity of the system.
21.5 Recent Developments
Machinery manufacturer Farrel has developed a two-stage compounder that it claims will have the highest dispersive mixing capability of any unit yet developed. It combines a two-stage continuous mixer with a single-screw extruder, and is aimed at a wide variety of new and demanding applications,
Figure 21.2. Powerful shearing and homogenizing of sensitive materials, retaining vital rheological properties, is provided by Farrel Corporation's Advex. (Photograph: Farrel Corporation)
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such as dispersion of pigments in fibre grade matrices, direct injection of plasticizers, and liquid stabilizers into PVC, polymer alloying, and processing of temperature-sensitive materials and rubber-based products. Reflecting current and expected market demands, it is also designed for the addition of wood flour and high levels of inorganic fillers, and for mixing of nano-composites. The company is also developing dedicated two-stage mixing rotors for specific applications. Key features are extra mixing length and residence time, with a greatly expanded processing window. There is a variable operating LD ratio from 5:1 to 10:1, and the counter-rotating mixer has rotor speeds of up to 1000 rpm. As well as using rotor speed, fill factor and temperature as control variables, the machine also introduces the possibility of variation in clearances of the chamber wall
Figure 21.3. Looking towards a new market demand, the Davis-Standard Woodtruder combines in a single system the latest plastics extrusion technology with technology for processing wood fibre. (Photograph: Davis-Standard)
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between the two stages. This allows selection of the intensity of first-stage mixing. In the second stage, a variable orifice can be adjusted to provide increased dispersive mixing, vacuum venting or downstream addition of fibres, additives or supplementary polymers. Vacuum venting is used to remove volatiles and moisture from the two-stage extruder. With its high speed and variabiUty of fill factor in two stages, the machine can disperse higher concentrations of low bulk density fillers, while the high frequency of product surface renewal gives high levels of moisture removal. Farrel claims that a 10% moisture content in wood flour can be reduced to less than 1% over a 5D process length, using atmospheric venting. Two-stage mixing, vacuum venting in the mixing stage, and use of a vented extruder will reduce the level much further. Among latest developments from Werner and Pfleiderer has been the adaptation of a slurry process (originally used for rubber/SAN compounding to produce ABS) for the production of nano-composites, in which the problem of handling such tiny particles is solved by delivering them in a water slurry. A special screw design makes it possible to incorporate long glass-fibre strands into a polypropylene compound, and further development delivers the compound not as extruded strands but as a compact hot extrudate, which can be fed directly to a hydraulic press for moulding a complete part such as an automobile front end. The next step will be direct extrusion of the long glass fibre compound through a sheet die onto a stack of cooling rolls. Whereas extrusion compounding with glass fibre is a continuous process, yet another development envisages integration with the injection moulding process, using a screw configuration that, in a twin-screw layout, can provide enough mixing/melting to allow the incorporation of glass rovings into the polymer melt even at low speeds, as during the first rotation of the screws at the beginning of the plasticizing cycle.
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CHAPTER 22 Background Information: Health and Safety Whatever the material or process, health and safety is vital and must be seen at three levels: • • •
hazards to workers in production, processing, storage, and transportation; hazards to the direct consumer and the public as a whole, in use of the product; and hazards to workers and the general public during disposal of the product.
The basic hazards can arise from skin contact, respiration and actual ingestion of the chemicals, and from other effects, such as fire or explosion, that may be caused by inadequate caution in handling some of them. Latest thinking on environmental care also spotlights the potential long-term effect of chemicals such as additives. Alongside extensive research into direct hazards to health, there has also been considerable development of safer forms in which to offer additives, to prevent or control escape into the atmosphere. A trend of recent years has been to supply additives processed into safe forms, in pellets, capsules, liquids and masterbatch concentrates and so, for the compounder and processor, the hazards have largely been taken out, but it is still important that they should be aware of them. For most compounders and processors of thermoplastics, the hazard from additives can now be safely contained upstream, during manufacture of the additives. In moulding and fabricating wet polymer systems, such as polyesters and polyurethanes, however, it is essential to take precautions.
22.1 Hazards by Additive 22.7.7 Carbon black
Although it can be considered a nuisance dust, there is no health hazard attributable to carbon black and most countries have accepted the US Threshold Limit Value (TLV) of 3.5 mg m~^, referred to total dust. Carbon blacks are not classified as hazardous materials or dangerous goods. Allegations that carbon blacks affect human health have occasionally been made, but there has been
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Table 22.1 Types of additives and their potential hazards Additive type
Possible hazard
Methods of avoidance
Carbon black
Escape into atmosphere, contamination of environment
Use masterbatch systems; if not possible, use effective packaging, in a dedicated area
Flame retardants
Possible formation of toxic fumes during a fire
Use only FRs approved by relevant authorities for the specific application and circumstances
Fillers, powders
Dust; respiration
Ventilation; use breathing masks where necessary; prefer non-dusting or hquid systems
Glass fibre
Skin irritation; dust
Use protective clothing; provide adequate ventilation
Pigments
Dust: contamination of products and workplace, escape to outside; possible dust explosion; heavy metals (cadmium)
Use formulated systems, liquids or masterbatch; where powder is essential, ensure good packaging, if possible use a dedicated area; ventilate; cadmium being phased out
Plasticizers
Leaching out, potential carcinogens
Ensure that compounding is carried out effectively. Known carcinogens have been phased out. Especially for food contact, medical or baby/toy products, use only grades approved by the appropriate authorities for the application or environment specified
Solvents
Escape into atmosphere; potential respiratory hazard; fire/explosion
Ensure adequate ventilation
Stabilizers, anti-oxidants
Heavy metals, food contact
Some heavy metals being phased out
confusion between carbon black and soot (as emitted from coal-, oil-, or gas-fired combustion plants) or coal dust. A compilation of relevant literature is contained in Bulletin No 4, Carbon black and health, published by the European Committee for Biological Effects of Carbon Black (ECBECB). Despite their very finely dispersed nature, carbon blacks usually do not burn well: when ignited in air, they smoulder slowly. Under certain conditions (with very high ignition energy and appropriate distribution) it is possible to make a carbon black dust/air mixture explode. Recommendations for safe handling are contained in the corresponding Material Safety Data Sheets (MSDS). 22.7.2 Titanium
dioxide
Local regulations for exposure limit should be followed. If these are exceeded, airpurifying respirators with a particulate filter should be used. As a principle of good industrial hygiene, safety spectacles with side-shields or better protection should be worn when handling titanium dioxide.
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22.7.3 Flame retardants
The use of antimony oxide in most countries is subject to regulations regarding conditions at the workplace. The generally accepted TLV for dust containing antimony oxide is 0.5 mg m~^. All grades are now available in low-dust or nondusting forms, such as: • • •
damped, paste, and plasticized grades, with the addition of 4% dioctyl phthalate (DOP), phosphate plasticizer, ethylene glycol, chlorinated paraffin, or water; granules, with a wax binder: cylindrical, free flowing, easy dispersing; masterbatches at 80-85% content, pre-dispersed in a wide range of compatible polymer carriers.
Antimony trioxide is classified in the USA as a Class B poison and must not be ingested. After handling the powder, hands should be washed. Food must be strictly forbidden in areas where it is dispensed and mixed. 22.1.4 Glass fibre
Recommendations for safe working with glass fibre were published in April 1995 by the European Glass Fibre Producers' Association (AFPE), Brussels. They concluded the following. After nearly a decade of international examination, there is no evidence for classifying continuous glass fibres as carcinogenic. Continuous filament glass fibres are safe (no danger) during production and use, if the recommended working methods are applied carefully. The great majority of glass fibres have a diameter of at least 6 |im (which never decreases, even after processing): for a fibre to have a pathogenic potential it has to be inhaled deeply into the lung, but this does not occur with for fibres larger than 3 \im. Although glass fibres can cause purely mechanical irritation to the skin, eyes or the upper respiratory system, this is not an allergic reaction and these mechanical effects can easily be avoided if the instructions in the safety data sheet are obeyed. 22.1.5 Styrene
monomer
Styrene is used in polyester resins as a solvent until cross-linking takes place, when it becomes an integral part of the thermoset. Unused styrene remaining in the resin is encapsulated or released into the atmosphere in gaseous state. Emissions of styrene produce a noticeable odour and at certain levels can produce a narcotic effect. Unsaturated polyester resins typically contain 3 5-50% styrene monomer as a cross-linking agent, and it is unavoidable that some of this will escape as vapour during open moulding and other processes that expose large surface areas of uncured resin during fabrication. At the least, styrene monomer vapour is an irritant and every effort must be made to minimize it at the
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workplace. The effect of various concentrations can be roughly classified as follows (measured in parts per miUion in the atmosphere): • • • •
100 ppm: maximum allowable concentration (MAC) 400 ppm: moderate irritation to eyes and lungs 1200 ppm: extreme irritation to eyes and lungs 10 000 ppm: may be fatal
There is considerable research by resin manufacturers to offer resins and processes that minimize emissions of styrene, to conform to increasingly tight legislation at the workplace. Styrene is not known to present any hazard to the general public, during the use of moulded products. 22.7.6 Isocyanates The main health risks to workers exposed to isocyanates include asthma and rhinitis. The chemicals are also irritants, and splashes in the eyes may cause chemical conjunctivitis, while contact on the skin can lead to dermatitis. Practical and authoritative advice on precautions which employers and managers need to take to prevent or control exposure to isocyanates - a legal requirement in many countries (in the UK, under the Control of Substances Hazardous to Health Regulations 1999) - is set out in a Guidance Note from the UK Health and Safety Executive (HSE). It recommends that where respiratory protective equipment is needed for use with exposure to isocyanates, from activities such as spraying, this will usually mean a correctly fitted full-face mask (to BS EN 136) attached to either a compressed airline breathing apparatus (topr EN 12419 or BSEN 139), or a selfcontained breathing apparatus (to BS EN 13 7). The revised guidance should now be followed. Other significant changes and additions in the guidance include a revised section on decontamination and spillages; information on the notification of reportable disease; and new information on short-term peak exposures.
22.2 Hazards During Production, Storage, and Transportation (Workers)
In the workplace, the current trend towards formulation of additives in safe forms, such as pellets, encapsulation and masterbatch systems has the advantage of preventing dust and contamination, both in processing and in storage. It also has the practical advantage of providing precisely measured amounts, so avoiding in-plant measuring with potential inaccuracies as well as potential health hazards. Workers therefore generally do not come into direct contact with the additives unless they are used on a large scale, for example in PVC compounding, where special precautions must certainly be taken. But here also, pre-measured, pre-dispersed 'one-pack' systems are growing in popularity. An area of particular activity has been plasticizers, where work has also been carried out on reduction of levels of plasticizer during processing. Plasticizers enter the environment mainly by evaporation during processing - estimated to
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range from 0.03% in injection moulding up to 2% in coating processes. These levels are continually being reduced by installation of incineration, scrubbing and filtration systems in processing plants. Another line of recent development work has been to adjust the particle distribution of the resin system, to improve flow and use of a plasticizer. Researchers have shown that, in plastisols for flooring applications, it is possible to reduce the consumption of plasticizers and diluents by using resin systems with perfectly spherical particles with an optimal particle size distribution. The level of plasticizer can be reduced from 50 to 30 phr without changing the flow behaviour of the plastisol signiflcantly. There is no sedimentation, and extremely thin films can be produced. An increased level of 15 jim monodisperse particle resin blended into a fine particle resin (0.2-2 )Lim) increased the amount of free plasticizer in the system. 22.2.7
Fire/explosion
Catalysts and activators can react with each other with explosive violence, and must never be mixed directly with each other. Activators and monomers are flammable and have a shelf life of about three months, stored at 20°C, in the dark. Resins and curing agents are flammable and must be kept away from naked flames. Smoking must not be allowed when using these materials. 22.2.2 Emissions
The most frequently encountered emissions in plastics processing are probably solvents (from adhesives and paints) and styrene monomer (from polyester/glass lamination). There may be a health hazard from curing agents: ahphatic aminetypes can cause serious irritation (even burns) and there is also a serious rash/ asthmatic-type response. Liquid organic peroxides, such as MEKP, should be treated with extreme caution. They are sensitive to heat, are themselves combustible and will promote combustion. 22.2.3 Skin/body
contact
Aromatic amines are less hazardous from skin contact; they are usually solids and there is no vapour hazard unless at elevated temperature. Anhydrides can cause severe eye and skin irritation and even burns. Polyamide types are less hazardous and are considered to present a low level of health hazard. The catalytic types are too diverse to make a general statement, and intending users should discuss appropriate precautions with the supplier. Some reactive diluents are hazardous to handle and can produce skin/eye irritation. They are considered somewhat more hazardous than aliphatic aminetype curing agents and considerably more than liquid epoxy. They may also present inhalation hazards. Resin modifiers vary considerably and it is not possible to make any general statement. Intending users should discuss appropriate precautions with the supplier.
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In sufficient concentration, styrene monomer vapour (used as a solvent in polyester resins) will irritate the eyes and can cause burns if it is not washed off immediately with plenty of warm water. Particular care must be taken with liquid catalysts and promoters: liquid organic peroxides, such as MEKP, should be treated with extreme caution and may irritate the eyes, skin and respiratory passages. Protective goggles should be worn, as a necessary precaution. 22.2.4 Dust By their nature, fillers vary greatly in degree of hazard, from non-hazardous types (such as clays), to serious inhalation, explosion and/or fire hazard for dusts of glass, silica-bearing powders, and powdered metals. There can be the risk of dust explosion, especially in areas for finishing or machining mouldings. Adequate ventilation, sensible layout, and good clear working space are essential. Legislation covers this in various countries. A typical respirable dust limit is 5 mg m"^ as a minimum time-weighted average over an eight hour period. In practice, sanding FRP, if there are no engineered solutions, may well exceed this limit. Glass fibres can break during processing, forming fine particles which can irritate the skin and can easily be inhaled. Dust produced by grinding/sanding of fibre-reinforced products should not be inhaled and, wherever these are produced, operators should be provided with facemasks or respirators. Skin exposed to fibre dust may develop a rash, and frequent washing of hands, arms and face is recommended. Barrier creams applied lightly to the hands and arms will reduce sensitivity. Dust from carbon fibre can be electrically conductive. There are two methods of dust control: •
•
Dilution: installation of a booth in which air can be moved at high volumes, lowering the concentration of possibly hazardous dust, and passing through a filtration system. Workers are still exposed to dust and must wear protective clothing and a system can be costly due to the high volume of air, and possible loss of heating (or cooling) if it is exhausted externally. Directed airflows around the workplace are a possible improvement. Capture: where possible, capturing dust at source is more effective, but there is no single totally effective method. Realistic expectations are 6 0 95% effectiveness, depending on shape and composition of the product being finished. The best solution recommended is a combination of both dilution and capture.
22.3 Hazards During Use (Direct Consumer and General Public)
Under normal circumstances, additives locked in by efficient compounding should not escape - except, of course, for those (such as flame retardants) whose function is to escape. The secondary effects of combustion on these additives.
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possibly involving evolution of fumes and smoke, is therefore a crucial aspect of selection. The latest developments in materials seek to avoid this, but burning of older compounds could present problems. For the consumer, a key question is the potential toxicity of additives, particularly their extractability and the circumstances under which they might be extracted, either directly (for products which are or could be chewed, such as baby soothers and toys) and indirectly, in the packaging of foodstuffs, or in equipment and surfaces in contact with foodstuffs during processing. 22.3.7 Toxicity - food contact
Toxicity is probably the longest and best-researched sector of plastics additives, with extensive documentation on both sides of the Atlantic (under regulations of the EU and the US Food and Drug Administration (FDA)). For as long as research has been carried out, the argument has turned on the inherent content of a compound, and the extractability of potentially hazardous substances. Legislation has tended towards inherent content (although it has constantly been argued that, under such a provision, glass would be excluded as a packaging material, since it contains lead - although it is not extractable). However, as the 'latest arrivals at the party', plastics have had to bear the brunt of latest analytical technology. In Europe, permissible additives for food contact applications are officially listed, and there is a wealth of information, from national plastics federations and from the EU. 223.2 Flame retardants
Flame retardants for plastics operate by starving a flame of oxygen, reducing the temperature, or by forming an insulating and quenching intumescent layer. Statistics show, however, that the most injuries and fatalities in a fire are caused not by heat but by chemical asphyxiation. So, as well as their effectiveness in extinguishing flame and not supporting subsequent combustion, flame retardant additives must also be assessed for by-products evolved as a result of combustion or exposure to high temperatures. The potential hazard to health and safety has long been a subject for argument and research. Early flame retardant systems that relied on the release of chlorine to douse a fire have been removed from use, and (although they are efficient and the scientific evidence them is still slight) there is constant vigilance on all systems using halogens, and some manufacturers prefer not to use them at all. The possibility that dioxins and furans can be produced from brominated diphenyl ether (PBDE), which is a highly effective flame retardant for high impact polystyrene, polyethylene, and polypropylene, was first identified in 1986 and, although the industry maintains that there is considerable evidence that PBDEs do not present a health risk, these flame retardants have also been phased out. Other systems based on bromine compounds are very effective, and are constantly being researched. The most recent regulatory developments include
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the International Programme on Chemicals Safety (IPCS) environment health criteria, and a revised German Ordinance on dioxins. For brominated flame retardants, the IPCS recommends: • • •
decabromodiphenyl ether: appropriate industrial hygiene measures, environmental exposure minimized by effluent and emission control, purities of more than 9 7% and controlled incineration; octabromodiphenyl ether: the same handling precautions, with improved purity (minimized levels of hexa and lower); pentabromodiphenyl ether: the IPCS expressed concern over its persistence in the environment and in organisms.
22.3.3 Plasticizers
Concern about the effect of certain plasticizers on human health, particularly their carcinogenic and oestrogenic effects, has been expressed from some quarters and there has been extensive study and testing to establish the facts. The products particularly under scrutiny have been PVC compounds for medical products and baby- and infant-care products, especially those designed to be put in the mouth. DEHP, which is particularly suitable for medical products, has been most under examination. It is known that some phthalate esters may produce testicular atrophy at high dose levels in sexually mature rodents. Massive doses have been shown to produce tumours in rats and mice, but now appears that this is specific to the species and safety factors in consumer products are at least 75 times higher. On the latest evidence, the safety factor of 75 for DINP can effectively be raised to 200-1170. Work on oestrogenic effects has shown that the most commonly used phthalates do not produce any effect on human reproductive organs. Work on BPP, octyl phenol, octyl phenol polyethoxylate, and diethyl stilbestrol that had earlier suggested a reduction in testicular size in rats is being reinvestigated. In medical products, the main plasticizer used (DEHP) is that recommended in the European Pharmacopoeia. DEHP has for several years been recognized as non-carcinogenic (or unlikely to be carcinogenic) by most international authorities, including the World Health Organization, the European Commission, and Health Canada. Until now, however, the world's leading authority, the International Agency for Research on Cancer (lARC) classified it as 'possibly carcinogenic to humans', based on early studies on rodents. The I ARC has concluded that more extensive recent research has shown that effects observed in rats and mice are not relevant to humans and the plasticizer is 'not classifiable as to carcinogenicity to humans'. There is a safety margin of about 14 000 in the estimated current intake of DEHP plasticizer, according to studies (by BASF). The plasticizer is considered detrimental to human reproductive organs after oral administration, at a level of 69 mg kg~^ body weight per day. Several studies have indicated an average daily
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lifetime exposure of 2.3-2.8 |ig kg~^ per day in Europe and 4 |ig kg~^ per day in the USA. A European Commission decision in 1990 confirmed that DEHP should not be classified or labelled as a carcinogenic or an irritant substance. Another study examined the possible health risk to humans from DEHP, particularly via its use in medical equipment, and concluded that a cancer risk is unlikely, even in haemodialysis patients, who are most exposed to the chemical. For teething rings, the industry decided many years ago to limit use of diethylhexyl-phthalate (DEHP), on grounds of potential carcinogenicity. More recent studies have also linked the replacement plasticizer, diisononyl phthalate (DINP), to cancer and other health risks but, at the time of writing, no test has produced a reliable correlation between how much DINP was in a product and how much was extracted. In a scientific opinion, the EU Scientific Committee states that phthalate plasticizers can safely be used in the production on soft PVC toys, provided that migration limits are observed. The Committee bases its opinion on an extensive review of the available data, and suggests guideline migration limits for each of six phthalate plasticsers. An EU risk assessment, published at the end of 2000, concluded that no environmental classification was necessary for DINP (diisononyl phthalate) and DIDP (diisodecyl phthalate). This means that there are no product labelling requirements to indicate an environmental hazard. More significant is the finding that no further information or risk reduction measures are needed beyond those already applied. The conclusion is valid throughout the EU and represents an internationally accepted view. The US 'Blue Ribbon' Panel, under the chairmanship of the former US Surgeon General Dr C Everett Koop, exhaustively reviewed a variety of published and unpublished scientific literature from North American and European sources, to evaluate any potential health risk from DEHP and DINP and concluded that these materials are neither carcinogenic nor have any other harmful effects, at the levels to which consumers are exposed. Regarding medical devices, the panel concluded that DEHP would not lead to negative health effects even for people who where highly exposed (such as those using dialysis machines). It also recognized the technical value of the plasticizer in conferring important physical properties for medical devices, such as transparency and resistance to kinking. On toys, the panel recommended further studies to expand knowledge of the exposure of children, but it took the view that DINP in toys was not harmful for children who use these toys normally. The panel also underscored the need for thorough testing of any alternative plasticizers. Another important finding is on the relevance to humans of the findings from feeding trials on rats. The US Panel came down firmly on the side of the industry, affirming that there is *a critical difference between the toxicology and mechanisms for the chemicals between rodents and humans'. This agrees with a European finding, by the Dutch Consumer Panel, which concluded that it was not reliable to assume that effects observed in rodent trials were automatically applicable to humans also.
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22.4 Hazards During Disposal (Workers and General Public)
Where compounds are broken down physically (such as in machining or finishing mouldings and blank workpieces - and increasingly today in size reduction, granulation, and reprocessing for recycling) there may be cases where additives are exposed, particularly as dust, and precautions (especially protective masks) must be taken. As with disposal of asbestos-containing building products, companies and organizations concerned with size-reduction and disposal must keep themselves well informed as to the likely content of the products they are called upon to handle. 22.4.7 Landfill - heavy metals
It has long been known that lead is a hazardous material to the general public, whether ingested by a child from a pigment in an old (and illegal) compound or breathed in from traffic fumes by people living close to motorway junctions. Although it has been proved to be an excellent stabilizer, in line with the general consensus, lead has been phased out of plastics additive formulations. Following work on landfill sites, it has become apparent that another heavy metal, cadmium, can also remain in the environment with potentially dangerous implications to general health, and this material (again, although excellent in bits function) is also being removed from formulations for pigments and stabilizers. While agreeing that heavy metals (mainly in pigments and dyes but also in compounds such as stabilizers, lubricants and anti-oxidants) produce trace amounts in the polymer, the Colour and Additive Compounders Division of the US Society of the Plastics Industry (SPI) argues that this is at levels far below those which might pose a significant threat to health and the environment. It also argues that the metal-containing materials are encapsulated in the polymer matrix that, under typical conditions, does not break down chemically. The bioavailability of the metals is thus so limited as not to present a concern. Regulations by OSHA require that facilities using regulated metals and metal compounds must evaluate and disclose information on exposure levels to employees, but these do not present a health safety threat. Studies on cadmiumbased pigments indicate that medium to high levels do not generate workplace concentrations above the limits. In landfilling, pigments in plastics will not dissociate and are insoluble in water. On incineration, air pollution control systems on modern solid-waste combusters meet US Federal Clear Air Act requirements for fly ash, and bottom ash is usually treated to mitigate migration ofmetals. Replacement of certain heavy metals has also occurred in PVC stabilizers (and nearly 60% of PVC applications are for products with a designed lifetime of longer than 15 years). Following replacement of stabilizers containing cadmium, the move is on to substitute lead. It was estimated that, by the end of the year 2000, 15-20% of lead-based stabilizers had been replaced by Ca/Zn systems and, if necessary, in combinations with pure organic co-stabilizers. In
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France, Italy, and Scandinavia cable sheathings stabilized with lead have recently been replaced with Ca/Zn. According to Henkel/Sidobre Sinnova, most window profiles in Europe are stabilized with lead, using systems based on lead phosphite, lead stearate, calcium powder, anti-oxidant, and lubricants. Systems containing cadmium, which are still used a little in Europe, are being increasingly replaced by lead compounds or calcium/zinc. 22.4.2
Incineration
Where compounds containing additives are burnt (as in energy-recovering incineration) there is again the potential release of additives and formation of dangerous substances. In efficient incineration this should not present any problem, but there are still not many efficient incinerators around. Again, products having a short life cycle will incorporate the latest technology, anticipating and avoiding such problems. But for older products (such as building products), manufactured before the potential hazards were identified, advice may be needed when it comes to disposal. A more recent concern (which is also contended) is the possible formation of dioxins during municipal incineration of plastics waste. This comes up regularly (and is as regularly refuted) in the case of PVC, but there seems no doubt that inefficient combustion (of anything) can produce dioxins.
22.5 Health and Safety at the Workplace: Some Guidelines
Safe processing of plastics is essentially a question of good housekeeping: good working conditions, cleanliness, ventilation, sensible plant layout, and suitable protective clothing: • • • • • • •
•
Avoid human contact. Maintain strict cleanliness, good housekeeping. Provide continuing instruction for employees. Wear suitable protective clothing to prevent skin contact. Impervious clothing can increase the hazard, if it becomes contaminated on the inside. Minimize contamination of the work area by placing clean, disposable paper on tables and benches. It should be replaced twice daily, or immediately after severe contamination. Reduce physical contact with materials by using disposable utensils, such as paper dippers, containers, etc. Prevent contact with vapours by providing ventilation sufficient to remove all vapour from point of use. Ensure that machines and robot devices are safely guarded, according to local regulations or manufacturers' recommendations. Give generous space around machines, for access. Allow wide gangways, especially if there are moving vehicles in the factory. Ensure that dust from the finishing process is kept under control by installation of collection devices and efficient ventilation.
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22.5.1 Reduction of emissions at the
workplace
In a commercial fabrication plant there are, basically, three approaches: • • •
organize working practices to minimize emissions; install effective ventilation, where it is most needed; employ (where practicable and available) low-emission resins.
22.6 New Developments: Solvents
Conventional solvents, which include chlorofluorocarbons, chloroform, and trichloroethylene, are the focus of increasing regulation around the world, on grounds of damage to the ozone layer, respiratory and explosion hazards, and pollution of ground water. Ethyl lactate, however, is non-toxic and biodegradable, occurring naturally in beer, wine, and soy products, but production cost has been too high to compete with conventional solvents (normally selling at US$3.52-4.40 kg~^ compared with about US$2 kg~^ for conventional solvents). A process developed by Argonne National Laboratory, Illinois, USA, is claimed to bring the price down to well below US$2.20 kg~^. The process is based on fermentation of a dextrose-based feedstock such as corn starch, with three key advantages: greater efficiency by reducing the number of steps in the conventional process; electrically driven advanced membrane separation stage, eliminating an undesirable salt by-product; patented purification-separation system (seen as the key to the economics of the process). In the conventional process the presence of water limits the reaction to only about 60% completion. The Argonne system enables excess water to be selectively removed, making it possible to increase the reaction to nearly 100% completion, with higher purity and lower processing costs.
CHAPTER 23 Background Information: Legislation and Testing Legislation governing the safety in manufacture, processing, use and disposal of plastics products has become a key feature of recent years and, while it is aimed mainly at plastics compounds and products, much legislation necessarily impacts on additives.
23.1 Blowing Agents
Following the agreement of the Montreal Protocol, the plastics industry has been highly successful in developing replacements for CFC blowing agents, used in polystyrene and polyurethane foams. As in many other cases, there was difficulty at first in rapidly introducing 'drop-in' replacements, and development of suitable blowing agents for self-skinned PU foams (as used for automobile interior components) and for rigid PU foams for insulation proved especially difficult. On the latest information, however, new technology has enabled the industry to meet the Montreal provisions - and, in some cases (as with waterblown MDI-based foams) it has even been possible to develop superior products.
23.2 Flame Retardants
The European situation regarding polybrominated biphenyls and biphenyl oxides (PBBs and PBBOs) has been set out by the European Brominated Flame Retardant Industry Panel (EBFRIP), a Sector Group of the European Chemical Federation (CEFIC). The Dutch Ministry of the Environment (VROM) in particular has long been concerned about PBBs and PBBOs and has considered introducing its own legislation, strongly opposed by the Dutch Plastics Federation (NEK) and against evidence by the Dutch National Institute for the Environment (RIVM) that studies of municipal waste incineration did not show any relation between bromine content of disposed waste and formation of brominated dioxins. In 1990, the EC Commission carried out a risk analysis which concluded that, although there was a potential for release of furan from incineration of waste.
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this was 'not confirmed by actual emission measurements'. Subsequently, with the support of some countries, a proposal was published to ban use of PBBO, but the Commission later decided to halt a proposed Directive until a new proposal on improved fire safety standards in furniture and furnishings was published. At an EC meeting in 1993, all member states (except The Netherlands) expressed their preference for a common EC policy and the Dutch plastics bodies were successful in convincing the Environment Ministry that the original risk Table 23.1 Summary of relevant environmental legislation Type
Regulation
Notes
Food contact
EC Directive 90/128/EEC
Positive list of authorized monomers. The Commission is now publishing its first Ust of additives which will require testing for migration in food-contact applications in a Directive
Flame retardants
EC Directive
Proposed Directive on polybrominated diphenylethers has not progressed
International Programme ofChemical Safety (IPCS) environmental health criteria
Recommends safety levels and handling/disposal for special brominated FRs
German Chemicals Banning (Dioxin) Ordinance
Revised 1994 to include brominated and chlorinated dioxins/furans: limits up to 10 ppb to July 1999 and 1 ppb afterwards on certain tetra and penta BDDs and BFDs and up to 60 ppb to July 1999 and S ppb after on total levels of specified hexa, penta and tetra BDDs and BDFs
Directive (91/3 38/EEC)
Harmonizes regulations on use of cadmium-based pigments, limiting use. Cadmium-based pigments may not be used in plastics materials where there are other satisfactory substitutes
Cadmium-based pigments
European Union VOC Solvent Solvents/volatile organic compounds Emissions Directive
Seeks to reduce VOC emissions from solvent-using installations by 6 5 7% by 2007, based on 1990 levels
Waste and recycling
Directive on Packaging and Packaging Waste (94/62/EC)
By 2 0 0 1 , to recycle at least 1 5% of each material in the packaging waste stream and 2 4 - 4 5 % of the totafity of packaging materials; 50-65% of packaging waste must be recovered
End of Life Vehicles (ELV) Directive EC 31/7/96
Restriction of use of heavy metals in car components. Recycling of end-life vehicles to 80% by 2006 and 85% by 2015. Entitles consumers to free take-back of end-of-life vehicles by 2006
Waste Electrical and Electronic Aims to control the use of certain materials and encourage re-use and recycling of all Equipment (WEEE) Directive electrical and electronic components
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assessment should be re-evaluated, with participation from industry. There has also been growing anxiety in Holland about the economic consequences of the proposed legislation, and it is difficult to predict the timetable, or whether legislation will be implemented at all. 23.2.7 Halogenated and brominated
flame retardants
Pressures to introduce restrictive legislation in Europe have eased as the debate has moved from the political arena to focus on assessment and management of risk. The main health and environment issue centres on halogen-based FRs, for possible formation of dioxin-related products such as brominated dioxins/furans by polybrominated biphenyl ethers (PBBE) under combustion conditions. These are very effective flame retardants and are widely used in polystyrene, polyethylene and polypropylene. Only a few of 75 identified brominated dioxin ionomers and 135 brominated furan ionomers are toxic, and they are only present in low concentrations in combustion. Less-toxic furans tend to be formed more than dioxins, and brominated dioxine/furans are less toxic than their chlorinated counterparts. The most recent regulations include the International Programme of Chemical Safety (IPCS) environmental health criteria and the revised German Ordinance on dioxins. IPCS recommendations for decabromodipentyl ether and octabromodiphenylether include hygiene measures, control of effluent and emissions, over 97% purity and controlled incineration. The IPCS expressed concern over the persistence of pentabromodiphenyl and polybrominated biphenyls and recommended that commercial use should cease until safety could be demonstrated. In 1994 the German Chemicals Banning (Dioxin) Ordinance was extended to include brominated dioxins/furans as well as chlorinated dioxins/furans. Certain tetra and penta-BDDs and BFDs were restricted (up to 10 ppb to July 1999 and 1 ppb thereafter) and higher limits (up to 60 ppb to July 1999 and 5 ppb thereafter) were imposed on total levels of specified hexa-, penta-, and tetra-BDDs and BDFs. Three German studies found that a compound containing standard loadings of DecaBDE showed no detectable amounts of brominated dioxins/furans (PBDD/F) and recycled forms showed amounts about 40 times lower than the limit of the German Dioxin Decree. Secondly, comparison of concentrations before and after recycling showed no change, indicating that no decomposition (debromination) had occurred. Finally, workplace exposure to PBDD/F was monitored during processing and at all stages, it was below the German workplace limits by about two orders of magnitude.
23.3 Heavy Metals/Cadmium Pigments
Regulations restricting or banning the use of heavy metals impact more on additive manufacturers than on plastics compounders. The main effect is in forcing replacements for lead stabilizers and pigments, and cadmium-based
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pigments. Lead stabilizers (which mainly concern PVC compounding) have now been effectively replaced by other systems, notably by tin and mixed metal (such as cadmium/zinc) systems. EC member states have voted that there should be no further restriction on the marketing and use of cadmium pigments for plastics. The International Cadmium Association (ICA) believes that this should now be safeguarded for the next three years, when a more far-reaching report on cadmium and cadmium oxide is expected. A Directive (91/338/EEC) was adopted by the EC to harmonize restrictions on the use of cadmium-based pigments that had been introduced by different countries. It does not ban the use of these materials but limits their use. For example, cadmium-based pigments may not be used in plastics materials where there are other satisfactory substitutes. Polypropylene and polystyrene are specifically listed as polymers where non-cadmium pigments must be used where possible. Other polymers where there is a restriction include thermoplastic polyesters, poly(methyl methacrylate), cross-linked polyethylene and melamine, urea, and polyester resins. A position paper by the Colour and Additive Compounders Division of the US Society of the Plastics Industry (SPI) claims that, at the normal levels of use (mainly in pigments and dyes but also in compounds such as stabilizers, lubricants and anti-oxidants) only trace amounts are produced in the polymer, at levels far below those which might pose a significant threat to health and the environment.
23.4 Plasticizers Phthalate plasticizers have been the target of a worldwide onslaught in the past few years, from consumer and environmental groups, on grounds of potential carcinogen and possible endocrine modulating effects. Evidence of both has been discovered in tests with rodents, but not in mammals, and there has been some dispute as to whether such results can be translated across the species barrier. The highest scientific body of the European Union, the EU Scientific Committee for Toxicity, Ecotoxicity and the Environment (CSTEE), concluded in 1998 on the basis of an extensive review of the available data, that there are safe migration limits for phthalates. In a scientific opinion, the Committee stated that phthalate plasticizers can safely be used in the production on soft PVC toys, provided that migration limits are observed. It suggested guideline migration limits for each of six phthalate plasticizers. In parallel with the European conclusions, an important judgement was reached in the USA by the 'Blue Ribbon' panel, which concluded that (far from being a hazard to health) the phthalate plasticizer used in PVC medical devices in fact makes a significant contribution to the effectiveness of the product, and its removal 'would actually pose a significant health risk to individuals who depend on these devices'. On the latest evidence, the safety factor for DINP can effectively be raised from 75 to 2 0 0 - 1 1 7 0 .
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ECPI and groups representing the toy industry are pressing for migration limits to be built into the new DG3 proposal, which would form an amendment to the Marketing and Use Directive. They could be based on agreed test methods, such as the Dutch method and the UK test.
23.5 Food Packaging
The ingredients used in products coming into contact with food and drink have been regulated for many years but, with new materials (particularly additives) constantly being introduced, and also with growing understanding of what actually constitutes a hazard, the legislation is under continuous revision. Toxicity is probably the longest and best-researched sector of plastics additives, with extensive documentation on both sides of the Atlantic. Legislators have tended towards controlling the inherent content of a compound (though, by the same token, glass should be excluded as a packaging material, since it contains lead). But the point is that the lead cannot be extracted, and the point is now being accepted when drawing up new legislation. For many years the effective international control has been the US Food and Drug Administration (FDA) and most plastics and additives are tested to these standards. In Europe, there is extensive national legislation and one of the most influential bodies has been the German Federal Health Ministry (Bundesgesundheitsamt CBGA) which is frequently cited in material specifications. The European Union legislation goes back to the 1990 Directive 9()/128/EEC, which was originally a positive list of authorized monomers. The Commission is publishing a list of additives that will require testing for migration in foodcontact applications. The Usted additives will need to be tested to show that the plastics compounds in which they are used comply with EC legislation for materials in contact with food, and the process of listing restricted additives will be continued by means of amendments to the 1990 Directive. The 5th Amendment contains some restrictions mostly in the form of specific migration limits; the proposed 6th Amendment is likely to contain all the remaining additives so far evaluated, together with their restrictions, which will again be primarily specific migration limits. The 5th Amendment contains the following restrictions: • • • •
specific migration limits maximum permitted quantity (QM) of the substance in the finished material or article maximum permitted quantity (OMA) of the substance in the finished material of article, expressed as mg per 6 dm^ of the surface in contact with foodstuffs any other restriction specifically laid down.
Some specifications for a few additives will also be listed.
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It also sets a total migration limit SML(T) applying to a number of additives, listed separately but treated as a group for control purposes, since they have similar toxicology.
23.6 Migration Levels Table 23.2 German BGA limit values for migration of elements from raw materials (DIN 53 770) Maximum migrated element in mg kg~^ raw material
Pigments^
Fillers''
Sb As Ba Cd Cr Pb Hg Se
500 100 100 100 1000 100 50 100
50 100 100 100 100 5
^ 178 Mitteilung, Bundesgesundheitsblatt 31, 363 (1988): Colouring agents for plastics and other polymers for consumer goods. ^ 167 Mitteilung, Bundesgesundheitsblatt 27,289 (1984): Extenders for plastics for consumer goods. Source: Sachtleben Chemie
Table 23.3 Permissible migration in toys (European Norm EN 71-3) Maximum migrated element in mg kg'Hoy material
All defined materials, excepting dough and finger-paint
Dough and finger-paints
Sb As Ba Cd Cr Pb Hg Se
60 25 1000 75 60 90 60 500
60 25 250 50 25 90 25 500
Source: Sachtleben Chemie
Amendments will be permitted to introduce new concepts which should make future testing more effective, such as food consumption factors, and migration modelling and functional barriers. It is almost impossible to present an exhaustive list of additives that have been accepted by the various authorities for use in contact with food. The following is a brief guideline:
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Table 2 3 . 4 A guide to food-contact additives Stabilizers/anti-oxidants Phosphites/phosphonites
Plasticizers Polymeric
Generally regarded as the most effective: main technical objectives have been more durable effect at lower dosage levels, with good retention of colour and transparency when required. Improvement of toxicological properties a continuing aim. FDA and BGA regulations recommend liquid anti-oxidants based on vitamin E.
Usually polyesters, based on adipic acid - extend the life of PVC end-products considerably; retarding migration, extraction and volatility.
Esters of fatty acids/ monocarboxylic acids
Liquid form: can be used as viscosity depressants for PVC pastes and secondary plasticizers for plasticized PVC compounds. Seek advice on food-contact approval.
Sebacates, adipates
Liquid form: provide good low temperature plasticizers for PVC, with fairly general food-contact approval.
Epoxidized grades (soya bean oil, linseed oil)
Stabilizing plasticizers with migration resistance in PVC compounds, alkyd resins and chlorinated paraffins; pigment dispersing agents in plasticized PVC. Soya bean versions have widespread approval for food contact. Advice should be sought for other types.
Colorants Dyes
Transparent, giving bright colours in light, but can be subject to migration.
Pigments
Azoic yellows (BASF - Paliotol) allows bright tints to be produced, suitable for food contact. New mixed-phase rutile yellow pigment (Bayer - Lightfast Yellow 62R) has higher tinting strength, satisfies food-contact requirements. Novel blue-shade red azo (Engelhard-Engeltone 111 5) alternative to high performance organics, meets FDA approval.
Thermochromic/ photochromic pigments
Micro-encapsulated liquid crystal systems, giving precise colour changes at specitic temperatures, or when exposed to light; particularly interesting for food packaging, indicating storage or cooking state.
'Intelligent' pigment systems
Developed by Sachtleben Chemie; can be incorporated in food packaging to control temperature of heat-sensitive products: under study by World Health Organization.
Pigment dispersants
Low molecular weight ionomers promote good pigment dispersion and come within the regulations of many countries for colour concentrates in food contact.
Processing aids Fluoropolymers Nucleating agents
Most fluoropolymer processing aids comply with indirect food contact regulations and can be used in PP and PE. MiUiken's Millad is widely approved for PP compounds for food contact applications.
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23.7 Moves to Establish a Threshold of Regulatory Concern (TRC) 23.7.7 US history
On 12 October 1993, the FDA published a proposal for a Threshold Concept, the final rule of which was published on 17 July 1995. FDA The Threshold of Regulation for substances used in food contact articles in covered under Par. 170.39 of CFR 2 1 . It provides that: • •
dietary concentration less than 0.5 ppb or dietary exposure less than 1.5 |ig/person/day (1.5 kg solid food/1.5 kg liquid food) substance is not a carcinogen or suspected carcinogen.
FDA Threshold Petitions must state the chemical composition, and give detailed information on condition of use, data showing that concentration is below 0.5 ppb: validated migration data (worst case), amount used in manufacture, residual level; results of analysis of existing toxicological data on the substance and its impurities; information on environmental impact. 23.7.2 European
history
SCF opinion on the scientific basis of the concept (requested by the EU Commission), published on 8 March 1996, found it a sound concept, but requested an up-to-date review covering more end-points than carcinogenicity, and possibly two Thresholds (non-genotoxic and genotoxic substances). It also noted that the FDA risk assessment process is different from Europe. APME formed a Task Force with the chemicals industry body CEFIC-FCA in 199 5 to evaluate a regulatory concept. ILSI (the International Life Science Institute) formed a Task Force on Threshold of Toxicity in 1996. ILSI is publishing its proposals for Threshold of Toxicological Concern (ToTC), aimed at establishing a human exposure threshold below which no toxicity data would be necessary, avoiding the need to expend valuable resources, costs and time on developing safety materials and their uses, and ensure that they comply with national and international legislation. A fundamental difficulty with the current EU system is that conventional exposure limits are based on 1 kg of food, 6 dm^ of plastics and a 60 kg person, which are felt to be too simplistic and conservative. An alternative system would divide plastics into two groups: 'commonly used' and 'minor' plastics, which would be up-dated with regular market surveys of use of plastics, monomers and additives, to ensure that the classifications as 'common' or 'minor' are consistent. This would treat commonly used plastics according to specification, and commonly used plastics that are not in compliance with these, according to a general list in which no plastics use factors were applied. Minor polymers would be treated according to a general list, with a plastics use factor applied.
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23.8 The User's Viewpoint
From the user's point of view, packaging is a long and sometimes complex chain, in which it is increasingly vital that manufacturers and suppliers at all the different levels pass down to their customer the safety data specific to their part of the chain. Upwards or upstream traceability is of paramount importance today, because manufacturers of consumer goods must be able to document the origin of raw materials, including packaging Since 1994, both Nestle and Unilever have such systems, operating at three levels, according to risk: simple applications (e.g. for unprinted plastic film), qualitative composition and/or purity of material (for can and closure coatings, mineral hydrocarbons, plasticizers and auxiliary items when there is contact with the mouth) and a dossier of compliance for ovenable packs, inner printing and recycled materials. It concludes that chemical substances present in the diet that are consumed at levels below 1.5 |Lig/person/ day pose no appreciable risk. For each application, an appropriate exposure assessment method needs to be applied. A ToTC needs to be 'translated' into an application-specific TRC. 23.9 Medical Products and Packaging
The United States Pharmacopeia (USP), which is responsible for establishing legally recognized product standards from drugs and other health-related articles, has considerable influence worldwide. In the 196()s, methodology and requirements were established for plastics used for pharmaceutical containers and closures and these were subsequently adopted by manufacturers of medical devices. USP tests measure the biological reactivity of plastics in contact with mammalian cell cultures {in vitro) and via implantation and injection of extractables into laboratory animals {in vivo). In Europe, medical devices are strictly regulated by the EU's Medical Device Directive (93/42/EEC). Other influential bodies are the World Health Organization (WHO), the European Commission, Canada Health, and the International Agency for Research on Cancer (lARC). In the absence of adequate guidance in the past on use of plastics in manufacture of medical devices, the medical industry has tended to use Class VI materials, which were, in fact, an 'overdesign', on the assumption that the advanced level of testing involved reduces the biological and legal risks. On the deficit side, there is no differentiation in assessment or control between the plastics commonly in use and those with low exposure to the diet, or between monomers and additives with known high or low migration potential. The result is the cost of compliance and enforcement is much higher than the lower risks require. 23.10 Waste and Recycling
There is an increasing amount of legislation worldwide concerning the avoidance and disposal of waste, notably European Directives on packaging.
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automobiles and electrical/electronics goods, some of which impacts on additives. The broad frameworks of the EU Directives are as follows.
23.70.7 Packaging A Directive on Packaging and Packaging Waste was agreed in December 1994 (94/62/EC), to minimize the amount of packaging used in the market and to set challenging targets for recovery and recycling of waste packaging, to be achieved by the year 2 0 0 1 . The overall targets are: at least 15% of each material in the packaging waste stream must be recycled; 2 4 - 4 5 % of the totality of packaging materials must be recycled; 5 0 - 6 5 % of the packaging waste must be recovered (meaning the sum total of the amount recycling and the amount sent for energy recovery of combustible packaging in energy-from-waste plants). This has no direct impact on additives (see Chapter 20), but the assembly and processing of large amounts of mixed plastics waste will increasingly raise the need for development of suitable compatibilizers. Reprocessing of materials may well call for improved stabilizers and additives to boost mechanical properties of compounds. A useful list of the regulations covering disposal of packaging materials in the countries of the European Union is published by the Association of European Plastics Converters, EuPC {A Practical Guide for complying with the Packaging and Packaging Waste Directive). It summarizes in a simple way the legislation in each member state and identifies the particular obligations placed on packaging manufacturers in each country.
23.102 Electrical and electronics A similar effect may be expected from the EU Directive WEEE (Waste Electrical and Electronic Equipment). This aims to control the use of certain materials and to encourage re-use and recycling of all electrical and electronic components (defined as 'that equipment which is dependant upon electric currents or electromagnetic fields in order to work properly'). For compounders, the immediate implication is to control the use of flame retardants, and a specific aim of the WEEE Directive is to reduce or eliminate halogenated flame retardant additives in the plastics compounds used for E and E products. The deadline for this is 2004, but there will obviously be much discussion as to which FRs should be phased out. WEEE will also require products to be certified as containing recycled material. As a result, supply of compounds will need to be certified - as by ISO 9001 certification for compounding. Compounds sourced from recycling of appropriate scrap will be certified as to their content of recyclate, physical properties and colour. The ISO 9000 system will provide the means for auditing, to provide the information required by the WEEE Directive.
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Automobiles
In Europe, the European Commission DGXI set three main objectives in its End of Life Vehicles (ELV) Directive EC 3 1 / 7 / 9 6 . The original dates of implementation were put back by a further two years, after strong representations from the automotive industry: • • •
Restriction of the use of heavy metals (such as lead, cadmium and hexavalent chromium) in car components - but many parts are exempted from a general ban. Increasing the level of recycUng of end-life vehicles (currently 75% by weight) to 80% by 2006 and 85% by 2015. Entitlement of consumers to free take-back of end-of-life vehicles, also by 2006: states have insisted it is up to them whether car producers pay all take-back costs, public authorities would meet any shortfall.
There is also a strong demand from automobile manufacturers (especially in Germany) to include a percentage of material of proved recycled origin in the 'new' materials that they employ, which will call for testing and quality control facilities at the compounder level.
23.11 Physical Testing
With the movement to make manufacturers at all levels responsible for the performance and safety of their products, it is likely that plastics compounders will increasingly have to become involved with testing for quality control and assurance. Comparison of property data on materials and composites is only possible when there are standardized methods of sample preparation and testing. Although internationally agreed standards are progressively being issued by the International Organization for Standardization (ISO) which will in time be adopted by member countries as national standards, we are still to some extent in an interim stage, and data is often still presented according to national procedures laid down by the USA (ASTM), Germany (DIN), Britain (BSI), and France. Testing of additives falls largely within the existing criteria for testing resins: • • • • • • • •
property test method predictive significance hydroxyl number ASTM E2 2 2 corrosion resistance and thickening rate (indicating molecular weight) acid number ASTM D16 3 9 gel SPI test reactivity and demoulding time vapour phase osmometry
280
• • • • • • •
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gel permeation chromatography number and average molecular weight and distribution composition infra-red spectroscopy (also qualitative test for cured resins) composition NMR spectroscopy (qualitative and quantitative test) non-volatile material SPI test monomer content (with viscosity it indicates molecular weight) viscosity ASTM Dl 824, D2196, SPI test (also indicates molecular weight).
23.77.7 Mechanical tests
23.11.1.1 Tensile strength and
modulus
Tensile strength is the maximum tensile stress which a material is capable of developing. It is calculated from the maximum load carried during a tensile test and the original cross-sectional area of the specimen. The type of specimen to be used is prescribed in ISO 52 7 and 3268 (the latter deals exclusively with glass fibre composites and describes some special forms of test specimens). The tensile test provides an insight into the stress/strain behaviour of a material under uniaxial tensile loading and makes it possible to distinguish between brittle and ductile materials. It is a useful tool for quality control and general comparison of properties, but it cannot be considered representative for applications with load/time scales widely different from those of the standard test. The tensile modulus is taken as the tangent to the initial linear part of the stress/strain diagram. 23.11.1.2 Flexural strength and modulus (ISO 178 and ISO 3597)
Flexural strength is determined on bar-shaped specimens with rectangular or circular cross-section, by supporting the specimen horizontally and applying a load vertically. The deformation of the flexed beam generates tensile and compressive stresses in the outer layers of the specimen, with a neutral zone approximately in the middle. Shear stress may develop along the neutral axis, depending on the ratio of support distance to specimen thickness used. Generally a span/thickness ratio of 16 is used but, for materials which tend to fail in an interlaminar shear mode (such as unidirectionally reinforced composites), a ratio of 20 is to be preferred. Flexural strength is a convenient method for comparing properties, because it involves a stress/deformation mode that is often encountered under service conditions, and the test specimens are relatively small. 23.11.1.3 Compressive strength (ISO 3604)
This is possibly to be incorporated into ISO 3597. Compressive strength is the maximum stress carried during a compressive test. Whereas the ISO standard describes compressive testing of cylindrical specimens made from unidirectionally reinforced rods, the US standard ASTM D-695 deals with
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compressive testing of flat panels and laminates and, to prevent buckling, a special fixture has to be used. Although not generally applied for characterizing the properties of composites, the test may be valuable for evaluating the effect of environmental conditions on composites, with an emphasis towards interfacial phenomena. 23.11.1.4 Shear strength Shear strength is the maximum load required for complete shear of the specimen, divided by the shearing area. There are several ways in which the shear can be applied: • • • • • •
punch-type shear tests; horizontal shear by means of a short-span flexural test; interlaminar shear testing of filament-wound ring segments; torsional testing of solid rods or filament-wound tubes; panel shear, by applying tension load along one diagonal and compression load along the other; off-axis tensile testing of directionally reinforced specimens.
The most widespread method for testing interlaminar shear strength (ILSS) is the short-span flexural test. If, despite the short span to thickness ratio, the specimen fails in a flexural rather than a shear mode, the result of the test should not be reported as ILSS. Short-span flexural testing is applicable to composites with unidirectional and bidirectional reinforcement, but does not give satisfactory results with planar random and three-dimensionally random short fibre composites. ILSS data are often used to specify the quality of a composite. The ILSS value is considered to be a direct function of interfacial adhesion. 23.11.1.5 Impact strength Impact strength is probably the most widely quoted (and least understood) of all tests on plastics. In fact, it is not a design property, but can be used for comparative tests, bearing in mind that the outcome relates to the test specimen and its processing conditions, rather than to the material itself. The effect of temperature is also significant, and some impact tests can be carried out at different temperatures, to show up a possible brittle-to-ductile transition. Three basic types of test can be differentiated: • tensile impact; • flexural impact on supported or cantilever beams; • multiaxial impact on a supported plate specimen. Tensile impact is not usually applied to composites. In flexural impact tests, the specimen can be freely supported and loaded centrally (Charpy) or it can take the form of a cantilever beam (Izod) and, in both cases, the impact is by a pendulum. Specimens can be tested either notched or unnotched. The configuration of the test is such that the impactor has an impacting energy greater than that needed to break the specimen. The energy lost by the
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impactor is divided by the cross-sectional area of the specimen and stated as 'impact strength'. In the Charpy test, this may give erroneous results when the specimen does not break into separate pieces, but folds around the impactor, so adding a frictional component to the absorbed energy, unrelated to the impact strength. In addition, it is rarely necessary in service to know the amount of energy needed to destroy an article, but rather the amount of impact that can be sustained without serious damage. In this respect, instrumented tests can contribute to better evaluation of impact characteristics, but composite materials may present some problems in reading the initial damage point from the force/deformation curve. In multiaxial impact testing, a projectile (either free-falling or driven) hits a plate supported on an annulus. By increasing the impact energy stepwise, the limiting value for onset of damage can be established. When the inherent energy of the projectile is sufficient to break through the specimen, a force/deformation curve can be recorded by means of a transducer mounted on the impactor. With a driven impactor, the effect of strain rate variation can be studied. 23.77.2 Thermal testing 23.112.1 Heat stability
Oxygen induction time (OIT) measurement is sometimes used for accelerated thermal ageing testing of polyolefins, and is still used as the basis for many national and international norms. Measured by DSC or DTA, usually at temperatures above 200°C with the polymer in the molten state, the OIT method produces rapid results - but these correlate only poorly with corresponding oven-ageing data from the polymer in the solid state, even if only phenolic antioxidants are used. For HALS, a negligible contribution is usually shown in tests in the molten state, whereas outstanding results emerge from tests on the solid material, more closely related to actual ageing. Accelerated tests in the melt can be used for quality control purposes, with a constant polymer/stabilizer system, but they do not permit selection of a stabilizer formulation with respect to its performance under actual use conditions. A new test for heat-ageing of plastics that gives more realistic data has been developed by the Dutch resins group, DSM. It produces what the company terms an 'Absolute Real Operating' (ARO) value, providing designers with a much more accurate measure of actual performance in use. DSM maintains that the accepted tests for heat ageing. Continuous Use Temperature (CUT), Temperature Index (TI) and Relative Temperature Index (RTI), give predictions that do not correspond to actual measurements in ageing. They identified three sources of error: • • •
measuring parameters at room temperature, after the plastic had cooled and strengthened; using relative values; extrapolating from accelerated ageing results.
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DSM's ARO value gives the absolute value rather than a relative value, with predictions based on real ageing (5000 hours) rather than accelerated ageing. Most important, it gives this value at the operating temperatures, rather than at room temperatures. 23.77.2.2 Light stability
Accelerated test methods using artificial light sources reduce the time span of a test, but outdoor exposure is the only real means of obtaining reliable information. Most manufacturers use data based on trials in Florida, USA. Outdoor exposure data are reported in kiloLangleys - a unit of energy irradiation (1 kLy = 1 kcal cm~^). On average, ~ 1 4 0 kLy relate to one year of exposure in Florida and ~ 190 kLy to one year in Arizona. 23.77.3 Electrical
properties
23.113.1 Surface and volume
resistivity
The most widely accepted test for determining conductivity of plastics is ASTM D257, which details procedures for measuring surface and volume resistivity. Where the intention is to find out dissipation of electrostatic charges, the more meaningful is surface resistivity. Volume resistivity measurements are useful in indicating the dispersion of a conductive additive throughout the matrix. Resistivity is the inverse measure of conductivity of a material; as it increases, so conductivity decreases. It should not be confused with resistance. Resistivity is calculated from measurement of resistance, using an equation that takes into account the geometry of the sample and electrodes. Under ASTM D257, surface resistivity is determined from measurement of surface resistance between two electrodes forming opposite sides of a square. Values are stated in Q per square. Volume resistivity (also termed bulk resistivity) is taken from the volume resistance between opposite faces of a 1 cm cube of material, and values are reported in Q cm. G=Gap distance between electrodes Pv = Rv^/T = ^ cm where Ry - volume resistance, A - area of electrode, T = thickness. 23.77.3.2 Surface resistivity
This is given by
Ps = RsP/G = ^ / s q where G = gap distance between electrodes, R^ = surface resistance, P = perimeter of electrodes.
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23.1133
Electrostatic
discharge
The main tests for assessment of electrostatic discharge are (USA) the following. ASTM D 257-75 (reapproved 1983) - standard test methods for DC resistance or conductance of insulating materials. Federal Test Method Standard No lOlC - 13 March 1980, Method 4046.1 - 8 October 1982 (charge notice # 1 ) . This measures the charge decay time of materials in film and sheet form. The maximum time accepted for charge dissipation is two seconds (as stated in M1L-B81705B-2, February 1972). 23.113.4 Static decay
ASTM D257 gives measurements which are the reciprocals of conductivity, not anti-static behaviour. Surface resistivity does not take into account the ability of the material to transfer an electric charge to the atmosphere or ground and samples that exhibit high surface resistivities under this test may still have excellent anti-static properties. A test for static decay is set out in US Federal Test Method 4046, which involves application of a 5000 V charge to the surface of the material, measuring the maximum charge accepted and then recording the time required to dissipate the charge once grounded. Results are reproducable and reliable. The procedure is now used in the US Military Standard MIL-B81705B, detailing acceptable decay times for packaging materials for electrosensitive devices and explosives. This Standard specifies that the charge induced by the application of 5000 V at A widely used procedure for measuring static decay uses an electrometer fitted with a sensor head capable of detecting momentary voltage changes through a high resolution timer. The test sample is shielded from external electrostatic interference by a Faraday cage and the apparatus is best used inside a chamber where humidity can be controlled. 23.77.4 Flammability
This section is based on descriptions of tests set out in the publication 'Principles of flame retardancy and test methods' by Anzon Limited (Technical Memorandum 1 & 2 and ITRI Ltd (Technical Bulletin No 4)). Flame retardants take effect only during the early stages of a fire. Criteria are therefore: • • • • •
Ease of ignition Combustibility Spread of flame Rate of heat release Smoke evolution
Because of the difficulty of precise measurements, testing of flame retarded plastics in the past has used classifications such as 'self-extinguishing' and 'nonburning', which can give misleading interpretations regarding actual fire performance. Some rationalization of test methods has been attempted by (for
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example) the International Standards Organization (ISO) and the International Electrotechnical Commission (lEC) - but this has often led to new tests being devised, rather than old tests being rationalized. Table 23.5 Tests designed mainly for rigid materials Specification Orientation Ignition source of specimen
Similar tests Time of application of ignition source
Comments
ANSI/ASTM Horizontal D635-77
Bunsen burner
30s
BS2782:508A
1: For self-supporting plastics 2: Used in u s Building Codes 3: Similar test used in UK Building Regulations
BS3532: 1962
Horizontal
Alcohol burner
30s
SABS 713 SABS 141
For unsaturated polyester resin systems only
VDE03()4
Horizontal
Silicon carbide rod (glowbar) heated to950°C
180 s
BS2782:508E DIN 53459 NFT51-015 UNE53035 ISO 181
Used in regulations for electrical equipment
Table 23.6 Tests designed mainly for flexible materials Specification
Orientation of specimen
Ignition source
Time of application ofignition source
Similar tests
Comments
ANSI/ASTM D568-77
Vertical
Bunsen burner
15s max
BS 2782:5086 DIN 4102 Pt. 1-B2 DIN 53906 SIS 650082 CSERF2/75/A ISOR1326
1: Used in US Building Codes 2: Similar tests used in Building Regulations in Germany and Sweden
BS 2782: 1970 Method 508C
Semi-circular
0.1 ml alcohol
Time for alcohol to burn
_
Source: Anion Ltd
1. For thin PVC sheeting 2. Used in UK Building Regulations
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23.11.5 Heat release
The rate of heat release is seen as the most important property predicting a fire hazard, since is governs both the rate of growth of fire and its maximum intensity. Most of the heat release tests are carried out with the cone calorimeter, which uses the oxygen consumption principle, to provide a reliable means of measuring the rate of heat release. The instrument can simulate a range of fire intensities, producing results that correlate well with results from full-scale tests. Most commercial instruments are also designed to measure several other key parameters: Time to ignition (TTI) is determined visually and is the period required for the entire surface of the sample to burn with a sustained luminous flame. Peak rate of heat release (PeakRHR) is the value of the rate of heat release versus a time curve. This is considered to be the variable best expressing the maximum intensity of a fire, indicating rate and extent of fire spread. Average rate of heat release (Av. RHR, 3 min) is the average value of heat release during the period between ignition and three minutes after ignition. This is thought to correlate best with the heat release in a room burn situation, where not all of the material is ignited at the same time. Fire performance index (FPI) is the ratio of TTI to Peak RHR. It has been suggested that it relates to the time to flashover (or time available for escape) in a full-scale fire situation. Smoke parameter (SP) is defined as the product of the average specific extinction area (smoke obscuration) and Peak RHR. It indicates the amount of smoke generated in a full-scale situation. Limiting oxygen index (LOI) is specified widely for determining the relative flammability of polymeric materials. It expresses flammability performance as a numerical value of the minimum concentration of oxygen in a nitrogen/oxygen mixture that is just enough to support combustion of the test sample, under the conditions of the test. Higher values indicate greater flame retardancy. It conformstoIS04589-2,ASTMD2863,andBS 2782 P a r t i , Method 1 4 1 . 23.11.6 Ease of ignition 23.11.6.1 Calorific value: ISO 1716 - calorific value of nnaterials
A bomb calorimetric method is used to measure calorific potential of materials. Similar tests are described in DIN 51900, NF M03-005 and in Italian regulations. This type of test is often used in conjunction with flammability test methods to determine classifications of materials for legislation (for example, in French Building Regulations, only materials with a calorific value of less than 2500 kj kg~^, as determined in NF MO3-005, can be considered for MO, the highest classification). 23.11.6.2 Flame spread
FMVSS 302: flammability of interior materials - passenger cars, multi-purpose passenger vehicles, trucks, and buses. Specified in regulation for flammability of
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vehicle interiors in USA, Germany and Japan. A 14 x 4-inch specimen is held horizontally. Flame from a Bunsen burner is applied to the underside for 15 seconds and the rate of burning is recorded. A sample which burns at less than 4 inches per minute passes the test. Similar tests are described in DIN 75200, ISO 3795 andJISD 1 2 0 1 . UL 94: Part 3 - vertical burning test. This test, devised by the US Underwriters Laboratory, is used worldwide to specify all types of plastics materials used in electrical devices and appliances It is one of the most widely used tests for electrical equipment, such as TV cabinets. A specimen is mounted vertically and a standard gas flame is applied to the lower edge for two periods of 10 seconds. The classification depends on the time for flame to be extinguished and whether the material drips during the test. The highest rating, V-0, is given when the sample is extinguished within five seconds and does not drip flaming particles. The classification also cites the thickness of the specimen. Table 2 3 . 7 UL 9 4 requirements Condition of test (time in seconds) Burning time after first ignition Burning time after second ignition Total burning time (5 samples/10 ignitions) Time for glowing combustion - second ignition Ignites cotton
Criteria for classification
v-o
V-1
V-2
<10 <10 <50 <30 No
<30 <30 <250 <60 No
<30 <30 <250 <60 Yes
23.77.7 Smo/ce tests
Measurement of the density of smoke evolved from a burning or smouldering specimen has been widely studied and several tests proposed. They differ mainly in that some measure the density of hot smoke as evolved from the specimen, while others allow the smoke to cool and stabilize before density is measured. Other tests use a gravimetric method for smoke determination. NBS Smoke Box. Devised by the US National Bureau of Standards, this has long been the most widely used laboratory-scale method for measuring smoke generated from burning materials. Specimens may be burned in either the flaming mode or non-flaming (smouldering) mode. The specific optical density of the resulting smoke is measured photometrically. Data are usually presented graphically as cumulative optical density (Ds) versus time curves, and the maximum corrected specific optical density values are quoted as either Dmc or Dmc/g. The test conforms to ASTME662, NFPA 258 and BS 6 4 0 1 . Other smoke tests include: •
Arapahoe Smoke Chamber: this test employs a cylindrical combustion chamber with a chimney connected to a vacuum source. A l . 5 x 0 . 5 x 0 . 1 2 5
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inch specimen is ignited by a Bunsen flame and allowed to burn for 30 seconds. The smoke evolved is collected on a filter at the top of the chimney and is weighed and calculated as a percentage of the amount of specimen burned. Michigan Chemical Ol/Smoke Densitometer: This equipment is designed to fit above the apparatus for determining limiting oxygen index. The specimen is ignited in an atmosphere of 1.15 xLOI condition and the smoke evolved is measured by a photometric method. Smoke generation is calculated from the optical density/time curve and specimen weight loss. To date, this test has not been used in legislation.
23.11.7.1 AS 1530: Part 3 - test for early fire hazard properties
of materials
A 6 0 0 x 4 5 0 mm specimen is mounted vertically and moved at a predetermined rate towards a radiant gas burner. The radiation intensity of the burning specimen is measured for at least 2 minutes after ignition, and a Spread of Flame Index is calculated from the time taken for the radiation intensity to increase by 1.4kWm-2. 23.77.7.2 DIN 4102 Part 1 - B1 - Brandschacht test
Specified for building materials and railway carriages in Germany. Four 190 X1000 mm specimens are placed at right angles to each other to that they form a shaft. A gas burner at the base of the shaft impinges on the specimens for 10 minutes. Bl classification is achieved if the mean residual length is at least 150 mm and the smoke gas temperature does not exceed 200°C. 23.77.7.3 VDE 0472 Part 804
Specified, together with similar tests, for cables worldwide. Pieces of cable 3.4 m long are assembled in a cableway approximately 25 cm wide, in a 4 m-high frame. A propane flame is applied for 20 minutes to the lower part of the cables. The test is passed if any flames extinguish themselves and the fire damage does not reach the upper end of the cableway. Similar tests are described in IEEE 383 andSS424 14 75. 23.11.7.4 FAR Part 25: Federal Aviation Regulations for materials used in aircraft
Specified by most aircraft manufacturers for materials used i n crew and
passenger compartments of commercial aircraft. Tests include flame spread of materials in horizontal, vertical, 45 and 60° positions. In addition to these tests, some manufacturers (such as Airbus Industrie and Lufthansa) also specify smoke and toxic gas emission criteria. 23.11.8 Fire tests for building
materials
USA: ANSI/ASTM D 1929-77- ignition properties of plastics. Specified in some US Building Codes. This test is also known as the 'Setchkin' test. A specimen 3 g in weight is assessed to determine the minimum temperature at which the vapour produced will ignite when subjected to a heated wire.
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BS 476:1968 Part 6 - fire propagation hox. Specified in UK Building Regulations, for definition of class 0. A 2 2 8 x 2 2 8 mm specimen forms one side of a box, the other sides of which are made from asbestos of a specified density. The panel is subjected to heat from electric bar elements and to small gas flames which impinge on its surface. Over a duration of 20 minutes, the temperature of the gases emitted from a flue at the top of the box is measured continuously and compared with temperatures obtained when a standard asbestos panel is used in place of the test specimen. Indices of performance are calculated from the differences. No method of classification is given, but fire propagation indices are used in the definition of Class 0 in the UK Building Regulations (1976). BS 476:1968 Part 7 - surface spread of flame. Specified in Building Regulations in UK, Netherlands, Denmark and France. A 900 mm long specimen is mounted in front of a radiant panel in such a way as to be subjected to a specific hat intensity gradient. Six specimens of each material are tested and, if five show no more than 165 mm spread of flame and the sixth no more than 190 mm, the material is classified as Class 1. There is also a small-scale test, with specimens 300 mm long. Similar large-scale tests are described in NEN 3883 and DS 1058:3. NF P 92-506 can be compared with the small-scale test. NF P 92-503 - electric burner test. Specified in France as one of the tests for classification of building materials. A 600 x 180 mm specimen is mounted at 30° and subjected to heat from an electric burner, with a pilot flame impinging on the lower edge. The highest classification is given when the specimen flames for no more than five seconds and there is no flame spread. Nordtest NT Fire 002 - ignitability test. Specified in Scandinavia in conjunction with other tests to classify building materials. Two 8 0 0 x 3 0 0 mm specimens are placed vertically and parallel to each with 50 mm gap between them. A propane flame is appUed to one until both burn. The highest classification is given if the specimen not exposed to the direct flame fails to ignite within 15 minutes. ISO/DP 5657 - ignitabilitij of building materials. Under development but could be adopted by various countries in Building Regulations. A 165 mm square specimen is placed horizontally in the apparatus and subjected to heat from a radiator cone and ignited by a dipping pilot flame. The highest classification is given when the specimen does not ignite. 23.77.9
Combustibility
ISO 1182-1979 - non-combustibilitg test. Combustibility tests are normally used to classify building materials. In this test, a 45 mm diameter x 50 mm cylindrical specimen is heated in a tube furnace at 850°C for 20 minutes. Thermocouples measure the temperature of the furnace wall and interior and exterior temperatures of the specimen. It is classified an non-combustible if: • • •
average temperature rise of furnace and specimen does not exceed 50°C duration of flaming of the specimen does not exceed 2 0 seconds weight-loss of the specimen is not greater than 50%.
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Australia: AS 1530 Part 3 - ignitabilitij index. Specified in Australian Building Regulations. A 6 0 0 x 4 5 0 mm specimen is mounted vertically and moved at a predetermined rate towards a radiant gas burner mounted opposite and parallel to it. The Ignitability Index is calculated from the time taken for the specimen to ignite. The same apparatus is used to measure Spread of Flame and Heat Release. Israel: SI 755 - ignitability test. Specified in Israeli Building Regulations. A 120 m m x l 2 mm specimen is mounted at 45° and a gas flame applied to the lower edge for 30 seconds. The best classification is given if there is no ignition of the specimen on contact with the flame. ANSI/ASTM E 84-79a - method of test for surface burning characteristics of building materials (Steiner tunnel). A 24-foot-long specimen is held horizontally as the roof of a 25-foot-long chamber. The ignition source is two gas burners, applied to the underside of one end. Flame spread is measured visually and instruments are used to determine fuel contribution and smoke density. The test is identical with UL 723 and ULC-S 102:1978, used in Canadian Building Regulations. Austria: AS 1530: Part 2 - test for flammability of materials. A 5 3 5 x 7 5 mm specimen is held vertically and an alcohol flame is applied to the bottom and allowed to burn for a maximum of 160 seconds. The flames are then extinguished and the rate of burning is recorded. The test is designed primarily for thin flexible sheets and textiles. France: NF P92'501 - radiation test for rigid materials. A 400 m m x 4 0 0 mm specimen is mounted at an angle of 45° and parallel to an electrically heated radiation source. Two propane gas burners are positioned close to the upper and lower faces of the specimen, to ignite flammable gases evolved from it. The test is carried out for a total of 20 minutes and flame spread is recorded. Surface spread of flame is also measured in test method NF P92-504. Scandinavia: Nordtest NT Fire 007. Also known as the Swedish hot box, the former uses 2 3 0 x 2 3 0 mm specimens to form four sides of a box, and flame from a propane gas burner is applied top the surface of one specimen. The class rating depends on the temperature of the effluent gases. The EC has harmonized fire tests for construction products, implementing Article 20 of Directive 89/106/EEC on construction products and mandating CEN to develop standards. The current classification is shown in Table 23.8. 23.11.10 Floor
covering
SABS 961 -fire index of floor coverings. A specimen is placed horizontally on the floor of a tunnel furnace incorporating a radiant gas burner. It is ignited with a pilot flame and flame spread is observed. A Spread of Flame Index is calculated from the distance burned. SABS 960 describes a similar test for building materials, in which the specimen is mounted at 30° from the horizontal. Scandinavia: Nordtest NT Fire 004. The test is designed to measure the ability of floor covering to resist fire spread and smoke development, a flaming wood crib is placed on a 1 0 0 0 x 4 0 0 mm specimen. After 15 seconds the blower and suction fans are switched on to give a specified airflow. Highest classification
Table 23.8 EC classification of fire tests for construction products Fire situation Fully developed fire in a room
Euro-class Class of product Level of exposure more A than 60 kW m->
B
Single burning item in a room
Level of exposure: C radiation on a limited area of max. 1 0 kW m-l
D
Small fire attack Level of exposure: on a limited area burning cigarette of a product
Test methods
No contribution to fire
Very limited calorific content and heat release. No flaming combustion. Limited mass loss
Documents: CEN/TC 12 7/N 2 2 9 and CEN/TC 12 7/N 2 3 0 , and list of non-combustible products
Very limited contribution to fire
Very limited calorific Documents: content and/or heat release. CEN/TC 127/N 2 2 9 and Limited mass loss. CEN/TC 12 7/N 2 3 0 Physically no spread of flame. Very limited smoke production
Limited contribution Very limited spread offlame Documents: to fire and smoke production CEN/TC 12 7/N 1 2 5
Acceptable contribution to fire
E
Acceptable reaction to fire
F
No performance determined
Documents: CEN/TC 12 7/N 1 2 5
Limited spread of flame and smoke production
Documents: Methanamine 'pill' test
Critical flux 1 0 kW m-2. Test: 3 0 minutes. Observation: extent of spread of flame, smoke production. Assess: passlfail Critical flux 4.5 kW m-'. Test: 30 minutes. Observation: extent of spread of flame. smoke production. Assess: pass/fail Extent of damaged area
g X-
'F:
e 3
52 E 3
6
S.
-
L -. o 31 n
5
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is given if flame spread is less than 550 mm and smoke density does not exceed 30%. 23.11.11 New
developments
Two new standards for testing fire hazards published by lEC/ISO, will be valuable tools to ensure international standardization of test methods, protocols and procedures, reports the International Electrotechnical Commission (lEC). As part of the lEC 60695-11 series, they will replace the lEC standards 6 0 6 9 5 2-4/0 and 60695-2-4/2 and also the ISO standards 1210 and 10351. They will also harmonize several pre-eminent international standards, including the US standard UL 94 Test for flammability of plastic materials for parts in devices and appliances, and ASTMD635,D3801andD5048. 23.11.12 Analysis
New technology for the determination of additives in polymers has been developed by Shimadzu, after a programme in cooperation with Volkswagen AG. The package includes a unique library of 468 fragment spectra from 174 additives, to make quality control analysis faster, easier and more effective. The system does not require any pretreatment of the sample. It is pyrolysed and all pyrolyte fragments are analysed by GCMS. The data is then reduced to an additive (fragment)-specific ion chromatogram, using re-analysis methods within the package. Ion chromatogram peaks are identified by means of a search of the library records and retention time information. Information on all additive fragments is then grouped together to give a complete determination. A fast, reliable, accurate, and cost-effective method of determination of phthalate levels is claimed by Shimadzu, Japan, a specialist in chromatography and spectroscopy. It uses two analytical methods, HPLC and GC, together, or comparing the UV spectra of the sample with those of a standard, Shimadzu has recorded a total analysis time of 16 minutes on six phthalates using HPLC and can separate phthalates by GC inside eight minutes. Both techniques have been demonstrated to yield accurate and consistent phthalate recovery rates (of 9 3 103%), in a rapid process requiring little manual time and effort. 23.11.13 Surface quality tests 23.11.13.1 Barcol hardness test
The Barcol hardness test is a good indication of cure. Barcol readings will vary with different resin systems; for example, the more resilient resins will normally give lower Barcol readings. The US Department of Commerce Product Standard PS-15-69 and ASTM D3299 indicate that readings should be specified at 90% of the manufacturer's recommendation for a particular cast resin. Laminates containing thixotropic agents and/or antimony trioxide have readings 3-5 units higher. Use of paraffin, synthetic fibre overlays, or an unreinforced gel coat may reduce the Barcol reading by 3-10 units.
Background Information: Legislation and Testing
23.11.13.2 Acetone
293
sensitivity
Not all air-inhibited surfaces can be detected by the Barcol hardness tests. It is recommended that the acetone sensitivity test should also be used, where appropriate. This involves application of a small amount of acetone to the resin surface. The wetted surface is then rubbed lightly with the finger until the acetone has evaporated. If the surface softens or becomes tacky, the resin has not fully cured. 23.11.13.3 Surface analysis A variation of the LORIA test uses new technology to evaluate the surface quality of Class A automotive body panels, eliminating subjective visual methods. It uses a low-intensity visible laser to detect surface deviations and imperfections. The beam is projected and scanned across the area, reflected on screen and captured by a high-resolution video camera. There is no contact with the surface, no stylus and no damage. Low-angle scanning allows study of flat or curved surfaces. During analysis, the scanning process is utilized more than 20 times across the part; data is stored by computer and mathematically reduced by special software to a quantified surface quality number, called 'Ashland Index'. 23.11.14 Colour testing As key end users, such as the automobile industry, become more stringent about the colour-fidelity of mouldings, particularly if they are to match or tone in with bodywork or other colours, it should be noted that the standard test for colour (which is used, where appropriate, in the reinforced plastics industry) is ISO. 105 (B02). This specifies a method for determining the resistance of the colour (of textiles) to action of an artificial light source representative of natural dayUght (xenon fading lamp test). Known as the 'Blue Wool Reference' and developed in the USA, the test method is to expose the colour patterns alongside a series of references of known light fastness, such as pieces of wool cloth dyed with blue dyes to a series of different degrees of fastness. As the pattern fades it is compared with the known references and coded under eight classifications, from 1 = most fugitive to 8 = most resistant. Each coding is twice as resistant as the preceding one. A typical range of pigments for polyester resins scores 7+ for most grades, the lowest reading being 4 - 5 . A dedicated software package developed to meet the need of colour analysis has been introduced by Bio-Tek Kontron Instruments, UK. Named Color View, it enables the user to define basic parameters, such as observation degree and illuminant. The user can also customize an illuminant definition. Colour analysis is achieved using a choice of evaluation modes from an extensive list of options. The colour comparison function in the equipment determines the difference between two samples, calculated according to the evaluation modes selected by the user. A hand-held instrument to measure colour quickly, easily and accurately on almost any type of surface - claimed to be the only such device - has been
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Additives for Plastics Handbook
developed by GretagMacbeth. The ColorEye XTH spectrophotometer makes it possible to measure both sample stepped chips and finished products, so ensuring consistency throughout the processing operation. Unlike heavier instruments, it can easily be used to check the colour at any stage. 23.11.14.1 Colour stability To enhance the prediction of light stability of plastics, the ASTM is revising its Standard D 46 74. Entitled Test Method for Accelerated Testing for Color Stability of Plastics Exposed to Indoor Fluorescent Lighting and Window-Filtered Daylight, determines the resistance to a plastic compound to colour change in a typical office environment, under prevailing illumination conditions. The current test method specifies the use of cool white fluorescent lamps and UVB313 sun lamps. The revision, according to Patrick Brennan, Chairman of the ASTM Subcommittee D20.50 on Durability, responsible for the standard, will admit to the test procedure other types of interior lighting sources, which will allow the method to be used to simulate a number of indoor environments.
23.12 Database A comprehensive database on chemical legislation in 25 countries has been published as a CD-ROM by the United Nations Economic Commission for Europe (UN/ECE). It covers 15 sectors of the industry, including materials in contact with foodstuffs, and transport and labelling of dangerous chemicals. Over 600 text summaries are given, with full references to the original legislative acts. Including Directives of the European Community, the database is intended to provide useful information and guidelines for countries worldwide that still have little or no legislation controlling chemicals. It also provides manufacturers, traders, legislators, and lawyers with instant access to information that is normally difficult to obtain.
APPENDIX A Conversion Tables Standard SI units and their derivatives Quantity
Special name
Symbol
Other recognized units
Multiples
Relations
Area
-
m2
Volume
-
m^
a (are), ha (hectare) litre
la=102m2, Iha^lO^m^ 1 litre = 1 dm^
Mass
-
kg
tonne
dm^, cm^, mm^ dm^ cm^, mm^ Mg, g.mg, mg
Linear density
-
kgm"'
tex
Density
-
kgm~^
Time
Frequency Velocity Acceleration Force Pressure Stress
s
l t e x = l()-^kgm-' = 1 gkm"^ kgdm'^ gcm~^
min (minute), h (hour), d (day)
Hertz
Hz
-
ms^^ ms"^
Newton Pascal
N Pa
bar
Pascal
Pa, N m-2
N tex-i
J
eV, kWh
Energy, work Joule quantity of heat Power Watt Viscosity Temperature Celsius Linear coefficient of expansion Thermal conductivity Heat transfer coefficient
lHz= I s ' I k m h - i = 1/3.6 m s - '
kmh-i
MPa,GPa, mbar MPa, Nmm"^ kj
W
kW
Pas
mPas
Wm-iR-i W m-^ K-'
1 tonne = 1 Mg
1 N = 1 kg m s~^ Ibar^lO^Pa, 1 Pa = 1 N mm-^ lNtex= lNkmg-\ 1 mPa = 1 N mm"^ lJ=lNm=lWs, l k W h = 3.6MJ 1 W = 1 J S-' 1 Pa s = 1 N s m-2
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Additives for Plastics Handbook
Conversion of US measure to metric US units
Metric
SI units
Length: 1 foot (ft) 1 inch (in) 1 thou
0.3049 m 2.54cm 0.0254mm
25.4mm
Area: 1 square yard 1 square foot 1 square inch
0.8361 m^ 0.0929 m2 6.451 cm^
Volume: 1 cubic yard 1 cubic foot 1 cubic inch
0.7645 m^ 0.0283 m^ 16.387m3
Liquid: 1 gallon (UK) 1 fluid ounce
4.5459 litres 28.4130cm^
Weight: 1 ton 1 pound (lb) 1 ounce (oz)
1.10160 tonnes 0.4536kg 28.349gm^
Force: llbf 1 Ibfin- (psi)
0.457 kgf 0.0703 kgfcm^
4.4482 N 6.8948 kNm
Density: llbft^ llbin-^
16.()18kgm 27.68gcm-^
27.68 Mgm
(1.8°C)+32 251.996gcal 0.00413 cal cm cm"^ s"' °C"'
1.0550 0.1442 Wm"^°C-'
645.16 mm^
28.317dm^
4.5459 dm^
Thermal: op
IBTU 1 BTU ft"^ h^
Appendix A: Conversion Tables Conversion of metric units to US measure Metric units
US
Length: 1 metre (m) 1 centimetre (cm) 1 millimetre (mm)
3.2808 feet 0.3937 inches 0.0393 Zinches
Area: 1 square metre 1 square centimeter Volume: 1 cubic metre
1.1959 yards^ 10.7639 feet^ O.lSSOinches^
1 cubic centimeter
1.3079 yards^ 35.3147feet^ 0.061 inches^
Liquid: 1 litre 1 cubic centimeter
0.2199 gallons (UK) 0.035 3 fluid ounces
Weight: 1 tonne (te) 1 kilogram (kg) 1 gram(g)
0.9842 tons 2.20461b 0.03 53 ounces
Force: Ikgf 1 kgfcm - (psi)
2.2046 Ibf 14.22 3 31bfin -
Density: 1 kg m~ ^ 1 gcm~^
0.0624 lb ft^ 0.0361 Ibin-^
Thermal: °C
SI units
(°F-32)/1.8 241.9BTUinft^^h"i°F 1
1dm
9.8066 N 98.0665 k N m -
418.68Wmm-
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APPENDIX B Technical Terms
The following are technical terms commonly used in the plastics additives sector: Acetone: Activator: Additives:
Anatase: Antimony trioxide: Aromatic hydrocarbon: Aspect ratio: Brookite: Catalyst: Complementary colours: Copolymerization: Coupling agent:
co-product with phenol in cumene oxidation process, building block in methyl methacrylate and bisphenol A, used in solvents. (also called an accelerator or promoter) a chemical compound used with a catalyst to permit polymerization at room temperature. the term used for a large number of specialist chemicals that are added to resins/compounds to impart specific properties (such as flame retardancy, impact improvement, UV resistance). a crystalline form of titanium dioxide (Ti02) in which every TiOf, octahedron in the crystal lattice has four edges common to other TiO^ octahedra. a commonly used flame-retardant additive for plastics, especially polyesters. a hydrocarbon chain with a benzene ring. the length/diameter ratio of a particle or fibre. A crystalline form of titanium dioxide (Ti02) in which every TiOe octahedron in the crystal lattice has three edges common to other TiO^ octahedra. (also called hardener) a chemical compound (usually an organic peroxide) which initiates polymerization of a resin. mixed or spectral colours that together appear white. incorporation of more than one monomer into a polymer chain. a substance that promotes or establishes a stronger bond at the resin matrix/reinforcement interface.
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Additives for Plastics Handbook
the process of hardening of a thermosetting resin (by cross-linking of the molecular structure), under the influence of heat and/or curing agents. chemical compounds used to cure thermosetting resins. Curing agents: Curing time: the time taken for a resin to cure (polymerize) to its full extent. With a cold-curing resin, the time is measured from addition of either activator or catalyst. Curing time can be influenced by other chemical aids - retarder or accelerator. Did: a dihydric alcohol. Dye: intensely colouring substances which, when applied to a substrate, impart colour to it by a process which at least temporarily destroys any crystal structure of the colouring substances. oriented growth of crystals from two difl'erent minerals. Epitacy: The epitaxy relates to the considerable analogy of the structures of the partners. Ester: a compound produced by reaction between an acid and an alcohol. Esterification: condensation of acids with alcohols. Exotherm/ a polymerization reaction that generates heat/description exothermic: ofreaction. Fibre: a unit of matter of relatively short length, characterized by a high ratio of length to thickness or diameter. Filament: a single textile element of small diameter and very long length, considered as continuous. Filler: material (usually low-cost) added to a resin to extend it, or give special properties. Flow: the movement of a plastic compound, thermosetting or thermoplastic, under heat and pressure, to fill a mould. Gel: the state of a resin that has set to a jelly-like consistency, solid, but not yet hard. Goniospectral a colorimetric instrument which in increments of (e.g.) 1 photometer: nm in a wavelength range of 3 5 0 - 7 0 0 nm from the whole visible spectrum, reproduces the reflected light of a sample depending on the angle of incidence. Haematite: red-brown a-Fe203 with a corundum structure, the most stable form of iron (III) oxide. Hardener: see Catalyst. saturated dicarboxylic acid anhydride, containing HEX acid anhydride: chlorine. a resin or reinforcement made from two or more different Hybrid: polymers or reinforcement materials. decomposition of chemical compounds by water. Hydrolysis: a technically important titanium mineral (FeTiOs). Ilmenite: saturation of reinforcement with a liquid resin. Impregnation: Cure:
Appendix B: Technical Terms
Inhibitor: Interface: Interference:
Interphase: Light initiator: Magnetite:
Monoester: Monomer: Optical density:
Peroxides: Pigment:
Plasticizer: Polycondensation: Polyester: Polymer: Polymerization: Promoter: Reactive resins: Refractive index: Release agent:
301
an additive that retards or prevents chemical reactions (such as cure). the contact area between reinforcement and matrix resin. superimposition of oscillations and waves. Light waves can interfere when they are coherent (i.e. when they are split by reflection, refraction or diffraction from one and the same wave train). the area surrounding the interface, extending into the matrix resin area. a compound that starts a reaction by being activated by light. the most stable form of iron with an inverse spinel structure Fe"Fe2^04, strongly ferromagnetic. It occurs in nature as black magnetic iron ore (loadstone). a simple ester. a compound containing a reactive double bond, capable of polymerizing or copolymerizing. in an optically more dense medium the speed of light is slower than in a less dense medium. The refraction of a ray of light occurs at the crossover from an optically less dense to a more dense medium towards the perpendicular of incidence; at the crossover from an optically more dense to a less dense medium it occurs away from the perpendicular ofincidence. oxygen-rich compounds used to cure polyester resins. intensely colouring substances usually applied in vehicle and retaining to some degree their crystal or particulate structure. Some pigments have the additional value of conferring magnetic or corrosion protection properties. a chemical compound added to some plastics to render them softer or more flexible. preparation of polyesters with liberation of water. the usual term for an unsaturated polyester resin. a long-chain molecule, consisting of many repeating units. the chemical reaction (linking of monomers) to produce a polymer. see Activator. liquid resins which can be cured by catalysts and hardeners to form solid materials. according to Snell's law, during refraction the quotient of the sine of the angle ofincidence 8 and the sine of the angle of refraction 8 remains constant. a substance which prevents a moulding from sticking to the mould surface, thus facilitating its release from the mould after curing; also known as a parting agent: it may
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Additives for Plastics Handbook
Room temperature: Rutile: Separating compound: Sink mark:
Styrene: Thermoplastic: Thermoset:
Thixotropy: Viscosity: Wet-out:
be a chemical compound or a solid material such as a cellulose or plastics film. room temperature (RT) is taken as 20°C (68°F). A crystalline form of titanium dioxide (Ti02) in which every TiOe octahedron in the crystal lattice has two (opposite) edges common to other TiOe octahedra. see Release agent. a depression on the surface of a moulding, usually caused by local internal shrinkage associated with variation in thickness (frequently can occur on the 'good' side of a moulding, where there is a rib or boss on the underside). an unsaturated monomer, widely used with polyester resins. a plastic that softens each time it is heated. a plastic that flows and then sets permanently on first heating, as a result of setting up a three-dimensional cross-linked molecular structure, and subsequently will not soften or dissolve. the ability of resins to change their viscosity, liquefying on being shaken or stirred. the resistance of a Hquid to flow (and therefore to mixing/ processing); high viscosity is thick, low viscosity is thin. complete wetting/saturation of a particulate or fibrous surface with a resin or carrier.
Standards and Testing Institutions
The following are the commonly encountered abbreviations designating the standards and tests operated by the leading world institutions: ANSI AS ASTM BS CSE DIN DS FAR FMVSS ISO JIS NEN
American National Standards Institute, USA Standards Association of Australia, Australia American Society for Testing and Materials, USA British Standards Institution, UK Centro Studi ed Esperienze dei Vigili del Fuoco, Italy Deutsches Institut fiir Normung eV, Germany Dansk Standardiseringsrad, Denmark Federal Aviation Regulations, USA Federal Motor Vehicle Safety Standard, USA International Standards Organization Japanese Industrial Standards Committee, Japan Nederlands Normalisatie-Institut, The Netherlands
Appendix B: Technical Terms
NF NS ONORM SABS SFS SI SIS UL ULC UNE UTE VDE
303
Association Frangaise de Normalisation, France Norges Standardiseringsforbund, Norway Osterreichisches Normungsinstitut, Austria South African Bureau of Standards, South Africa Suomen Standardisoimisliitto r.y., Finland Standards Institution of Israel, Israel Sveriges Standardiseringskommission, Sweden Underwriters' Laboratory Inc., USA Underwriters' Laboratory of Canada, Canada Instituto Nacional de Racionalizacion y Normalizacion, Spain Union Technique deFElectricite, France Verband Deutscher Electrotechniker e.V., Germany
Recommended Books and Journals
For additional reading on specific topics, the following books are particularly recommended: Advanced materials: source book and directory (annual: Elsevier Advanced Technology) Composites - a profile of the worldwide reinforced plastics industry market and suppliers (Elsevier Advanced Technology) Data book ofthermoset resins for composites (Elsevier Advanced Technology) Handbook for plastics processors (J A Brydson; published by Heinemann Newnes/ PRI) Handbook ofplastic and rubber additives (Gower) Handbook of polymer composites for engineers (ed. Leonard HoUaway, published by Woodhead) International plastics handbook (H-J Saechtling, published by Hanser) Plastics engineering handbook of the Society of the Plastics Industry (ed. Michael L Berins, published by Van Norstrand Reinold/SPI) Polymer engineering principles (Richard C Progelhof and James L Throne, published by Hanser) Polymer science and technology of plastics and rubbers (Premamoy Ghosh, pubUshed by Tata McGraw-Hill) SMC - Sheet moulding compounds, science and technology (ed. Hamid G Kia, published by Hanser)
Manufacturers'
handbooks
There is also a wealth of information contained in literature produced by manufacturers and suppliers.
304
Additives for Plastics Handbook
journals covering additives for plastics and rubber
Argentina Plasticos Magazine, Salguero 1939, 1425 Buenos Aires Australia Plastics News International PO Box 2 1 3 1 , St Kilda W 3182 Austria OsterreichischeKunststojf-Zeitschrift, Ebendorfer StraSe 10, A-lOlO Vienna Belgium Plastics and Machinery News, Av Carsoel 1268, B-1180 Brussels Brazil Journal de Plasticos, Rua Miguel de Frias 88-Gr 804, 24220-Niteroi Rio de Janiero Plasticos em Revista, Rua Piaui 1164 - Casa 8,01241Sao Paulo - SP China (Republic) China Plastics and Rubber, 21/F Tung Wai Commercial Building, 1 0 9 - 1 1 1 Gloucester Road, Hong Kong Denmark Plast Panorama Scandinavia, Struenseegade 7-9, 2200 Copenhagen N Finland Muoviyhdistys Tiedottaa, Mariankatu 26, SF-00170 Helsinki France Plastiques Modernes etElastomeres, 4:2 ruedes Jeuneurs, F-75002 Paris Plastiques et Caoutchoucs, 5 rueJulesLefebvre, 75009 Paris Plastiques Flash, 78 Route de la Reine, F-92100 Boulogne/Seine Germany Gummi Fasern und Kunststojfe, Dr Heinz Gupta Verlag GbR, Postfach 10 41 25, D-40852Ratingen K-PIflsiic2dii/n^,AufderHeide 20, Postfach 12 01 6 1 , D-30916Isernhagen Kunststoffe, Marburgerstrasse 13, D-64289 Darmstadt Kunststoff'Information, SaalburgstraGe 15 7, D-61350 Bad Homburg Kunststojf Journal, Thomas-Dehler-StraEe 27, Postfach 83 03 5 1 , D-81737 Munich 83 Plastics Industry Europe, Saalburgstrafi 157, D-613 50 Bad Homburg Plastverarbeiter, Im Weiher 10 Postfach 10 28 69, D-69018 Heidelberg Prodoc-Kunststojftechnik, Postfach 40 06, D-6100 Darmstadt
Appendix B: Technical Terms
305
India Popular Plastics, 126 A, Dhurwadi, off Dr Nariman Road, Prabhadevi, Bombay 400 02 5 Italy Industria della Gomma, Via C Battisti 21,1-20122 Milan Macplas, Centro Commerciali Milanofiori, 1 Strada - Palazzo F/2, 1-20090 Assago/MI Materie Plasticine ed Elastomeri, Editrice OVEST Sri, via Simone d'Orsenigo 22, 20135 Milan PoliplastiePlastichiRinforzati, ViaMecenate 91,1-20138 Milan Japan Japan Plastics, Kogyo Chosai Publishing Co Ltd, 14-7 Hongo 2-chome, Bunkyo-ku, Tokyo PlasticsIndustryNewsXentra\FOBoxNoll76,Tokyo 100-91 Netherlands Kunststofen Rubber, Postbus 71, NL-2600 AB Delft Norway Metaal en Kunststof, Postbus 71, NL-7000 BA Doetinchem Norsk Plast, Postboks 235 Skoeyen, N-0212 Oslo 2 South Africa Plastics Southern Africa, PO Box 704, Cape Town 8000 SA Plastinews, PO Box 792, Pinetown 3600 SA Spain Revista de Plasticos Modernos, Juan de la Cierva 3, 28006 Madrid Sweden Plast'Forum Scandinavia, Box 601, S-2 51 06Helsingborg Plast Nordica, Box 91 13, S-250 09 Helsingborg Switzerland Kunststoffe-Plastics, Vogt-Schild AG, ZuchwilerstraEe 2 1 , CH-4501 Solothurn Modern Plastics International, 14 avenue d'Ouchy, CH-1006 Lausanne United Kingdom British Plastics and Rubber, 3 7 Nelson Road, Caterham, Surrey CR3 5PP European Plastics News, PO Box 109, Maclaren House, 19 Scarbrook Road, Croydon CR9 1 OH European Rubber Journal, 20-22 Bedford Row, London WC1R4EW Plastics Additives and Compounding, Elsevier Advanced Technology, PO Box 150, Kidlington, Oxford 0X5 IAS
306
Additives for Plastics Handbook
Plastics and Rubber Weekly, PO Box 109, 19 Scarbrook Road, Croydon, Surrey CR9 1 OH Reinforced Plastics, Elsevier Advanced Technology, PO Box 150, Kidlington, Oxford OX5 IAS Technical Textiles International Elsevier Advanced Technology, PO Box 150, Kidlington, Oxford 0X5 IAS United States Modern Plastics, 1221 Avenueofthe Americas, New York, NY 10020 Plastics Engineering, 14 Fairfield Drive, Brookfield Center, CT 06804 Plastics Focus, PO Box 814, Amherst, MA 01004 Plastics World, 2 75 Washington Street, Newton, MA 02158 Plastics Machinery and Equipment, 1129 E 17th Avenue, Denver, CO 80218 Plastics Technology, 633 Third Avenue, New York, NY 10017 PlasticsWeek, 1221 Avenueofthe Americas, New York, NY 10020 Yugoslavia Polimeri, Kaptol 22, YU-41001 Zagreb
APPENDIX C Standard Abbreviations for Plastics and Elastomers
A ABSM
Acrylonitrile/butadiene/styrene
C CA CAB CAP CFC CN CP
Cellulose acetate Cellulose acetate butyrate Cellulose acetate propionate Chlorofluorocarbon Cellulose nitrate Cellulose propionate
E EPDM EPM EPS EVA, EVAC EVOH
Ethylene propylene terpolymer Ethylene propylene copolymer Expanded polystyrene Ethylene vinyl acetate Ethylene vinyl alcohol
F FEP FPM FR
Fluorinated ethylene propylene (also perfluoro ethylene/propylene) Vinylidene fluoride/hexafluoropropylene copolymers Flame retardant
G GP
General purpose
308
Additives for Plastics Handbook
H HD HI HMW
High density High impact High molecular weight
L LD LFI LLD
Low density Long-fibre injection moulding Linear low density (polyethylene)
M MD MF
Medium density Melamine/formaldehyde
O OPP
Oriented polypropylene (film)
p PA PAN PBTP PC PE PETP PETG PF PMMA POM PP PS PTFE PUR PVAC PVAL PVC PVDC PVDF PVF
Polyamide (also known as nylon) Polyacrylonitrile, Polybutylene terephthalate (polyester) Polycarbonate Polyethylene, Polyethylene terephthalate (polyester) Polyethylene terephthalate (glycol co-monomer) Phenol/formaldehyde Polymethyl methacrylate (also known as acrylic) Polyoxymethylene (also known as acetal, polyacetal) Polypropylene Polystyrene Polytetrafluoroethylene Polyurethane Polyvinyl acetate (also PVA) Polyvinyl alcohol Polyvinyl chloride Polyvinylidene chloride (also PVdC) Polyvinylidene fluoride Polyvinyl fluoride
R RIM R-RIM
Reaction injection moulding Reinforced reaction injection moulding
Appendix C: Standard Abbreviations for Plastics and Elastomers
s S-PVC
Suspension PVC
U UF UHMW uPVC
Urea formaldehyde Ultra-high molecular weight Unplasticized (rigid) PVC
V VLD
Very low density (polyethylene)
Sources: ISO 1043-1978
(DIN 7 7 28 Parti), DIN ISO 1629, industry practice
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APPENDIX D Trade Names
A Abril Abril Abril A-C Aclyn Acrawax Aerolite Aerosol Actimer Aetirox Aeumist Adeka Adimoll Advapak Advapak Akrochem Akro Aktisil Albidur Albiflex Albipol Albipox Albisil Alehemix Alfrimalsmall Alkanox Alkasperse Almax Almical Aloxan Alsilanlayered
fatty amide waxes Cosmie polyearboxylic aeid wax Paradigm fatty amide waxes polyethylene copolymer modifiers ionomer pigment dispersants bis-amide wax lubricants organic pigments solvent dyes flame retardants modified zinc phosphate micronized polyethylene waxes additives plasticizers lubricating stabilizers multifunctional stabilizers iron, oxide, red, black, yellow Pakone-pack blends functional fillers silicone toughness improver epoxy/silicone additives polyurethane-based resins epoxy-based resins silicone-based resins fillers, release agents particle reinforcing fillers anti-oxidants, phosphite liquid pigment dispersions alumina fibre semi-reinforcing fillers semi-reinforcing fillers silicate
Abril Abril Abril AUiedSignal AUiedSignal Lonza Acrol Acrol Solem Colores Hispania AUiedSignal Asahi Denka Bayer Morton Int Morton Int Akrochem Akcros Hoffmann Hanse Chemie Hanse Chemie Hanse Chemie Hanse Chemie Hanse Chemie Alchemic Alpha Calcit Great Lakes Colloids Mitsui Alpha Calcit Alpha Calcit Alpha Calcit
312
Additives for Plastics Handbook
Alsitalclayered Amgard CPC Amgard N Amgard P Amical Ancamide Ancamine Anox Anquamide Antistatic CB Apicolor Aqualiftmould Armid Armoslip Armostat Armoslip Armowax Atmer Axel Mold-Wiz
silicate FR: red phosphorus, masterbatch FR: phosphates FR: organophosphorus calcium carbonate epoxy curing agent epoxy curing agents antioxidants, phenol epoxy curing agents carbon black antistatic pigment concentrates release agents slip/anti-blocking agents slip agents antistatic agents anti-slip, anti-blocking agents impact modifiers anti-fogging agents, antistatics mould release agents
Calcit Albright & Wilson Albright & Wilson Albright & Wilson KMG Minerals Air Products Air Products Great Lakes Air Products Inducolor API Dexter Akzo-Nobel Akzo-Nobel Akzo-Nobel Akzo Nobel Akzo-Nobel Ciba Axel
B Baco ATH Baropol Bayfomox Bayplast Bewaxmould BFR Binisil Black Diamond Black Pearls Bloomgard Brancolor Bruggolen C Bruggolen F Bruggolen H Bruggolen L Bruggolen M Bruggolen P BurnEx Busanll-M2
flame retardants additive systems flame retardants pigments release agent blended flame retardants silicone lubricant masterbatch carbon black dispersions carbon black granule flame retardants additive/colour concentrates additives for cast nylon flame retardants heat stabilizers weathering agents impact modifiers, plasticizers lubricants, mould release agents flame retardants barium metaborate
BYK BYK-A BYK-WBMC
styrene emission suppressants air release for polyester resins wetting/dispersion agents
Alcan Chemicals Barlocher Bayer Bayer Diversey Anzon Micropol Chinghall Cabot Great Lakes Branco Briiggemann Briiggemann Briiggemann Briiggemann Briiggemann Briiggemann PO Corporation Buckman Laboratories Byk Chemie Byk Chemie Byk Chemie
Appendix D: Trade Names
c
313
Cabelec Calcilit Calciplast Capow Casabond Casamid Casastablatex Catafor Cereclor
electrically conductive masterbatch high purity calcium carbonates high purity calcium carbonates powder coupling agent bonding agents non-reactive polyamides thickening agents anti-static agents chlorinated paraffins, FR agents
Charmax Chemica Chimassorb Chlorezflame Chromoflo Clean-Wiz
flame retardants reinforcing filler (mica) light/UV stabilizers retardants pigment dispersions (low vise) cleaning, stripping agents
Coatex Coathylene Colormatch Colour Diamond Combibatch Comistab Conbio Condeg Conduct-o-Fil Conselect Constab Constab Colour Corducell Cordulen CordumaUV Cordustat Crodamide Cryoflex Cyanox Cyasorblight
phosphoric ester dispersing agents microfine thermoplastic powders pigment dispersions pigment dispersions additive/colour masterbatches stabilizers agricultural film masterbatches degradable additive masterbatches conductive additives special agricultural masterbatches additive masterbatches pigment/dye masterbatches chemical blowing agents slip/anti-block/antioxidants/FR stabilizers anti-statics fatty acid amides plasticizers anti-oxidants stabilizers
Cabot Alpha Calcit Alpha Calcit Kenrich Thomas Swan Thomas Swan Thomas Swan Rhone-Poulenc ICI ChlorChemicals Marshall Incemin Ciba-Geigy Dover Plasticolors Axel Plastics Research Coatex Herberts Polymer Plasticolors Chinghall Sarma Comiel Constab Constab Potters-Ballotini Constab Constab Constab Nemitz Nemitz Nemitz Nemitz Croda Sartomer Cytec Cytec
D Dantosperse Dechlorane Plus Dehydrat Denka Denka Malecca
hydantoin ester dispersants chlorinated anti-static, anti-fogging agents fused silica silica filler maleimide copolymer
Lonza FROccidental Henkel Mitsui Mitsui
314
Additives for Plastics Handbook
Deplastol Deltaplast Deltavinil Devolite Dicalite Dimodanhigh Diolpate Diplast Disflamoll Disperplast Dolofil DorkafiU Dovernoxsolid Doverphos Drapex Dualite Duhor Durawool
plasticizer masterbatch colour masterbatch for PVC medium-size alkaline china clay diatomite, perlite functional fillers concentration anti-statics polymeric plasticizers PVC plasticizers flame retardants/plasticizers wetting and dispersion additives calcium/magnesium carbonate fillers china clay extenders anti-oxidants organophosphites epoxidized stabilizers polymeric microspheres magnesium hydroxide FR steel wool (fibres)
Dyhard Dyhard Dynamar Dynol
curing agent, powder coatings epoxy resin accelerators polymer processing additives PVAl wetting agent
E Eastobrite Ecosphere
optical brightening agent hollow glass microballoons
Edenol Elastolor Elbaplast Electrafil Elftex Elvaloy EMAC
plasticizers thermoplastic elastomer additives solvent dyes conductive compounds carbon black powder and granule plasticizers impact modifier/compatibilizer
Emopasta Endex Epilink
pigment concentrates additives epoxy curing agents
Epodil Epolene Esperaldicumyl EsperfoamMEK Esperox
epoxy modifiers coupling agent/compatibilizer peroxide peroxide peroxyester
Henkel Deltacolor Deltacolor ECC Redland Danisco Kemira Polymers Lonza Bayer Byk Chemie Redland Dorfner Dover Dover CKWitco Pierce & Stevens Duslo a s Sala Overbeck Handelsges SKWTrostberg SKWTrostberg 3M Air Products
Eastman Emerson & Cuming Henkel Plasticolors HoUiday Chemical DSM Cabot Erbsloh Chevron Chemical Inducolor Endex Corp Air Products (prev. Akzo) Air Products Eastman Witco Witco Witco
Appendix D: Trade Names
315
Eupolen Evatane Exocerol
organic pigments modifiers/processing aids exothermic blowing agents
Exolit Expancel Expansor Exterplast Exxelor
flame retardants thermoplastic microspheres blowing agents monomeric plasticizers polyolefinic modifiers
BASF ElfAtochem Boehringer Ingelheim Clariant Expancel Repi Coim Exxon
F Faradex FF680 Fiberglas Filolencalcium Firebrake ZB Firemaster Fireshield Flamtard S Flamtard Flanagen Fleka Flexaryl Fordacal FRCROS FR-930 Frekote FS Ftalidap Fyreblocflame Fyrol
conductive compounds bis(tribromophenoxy)ethane glass fibre carbonate masterbatch zinc borate flame retardants antimony oxide FR zinc stannate magnesium, zinc borate FR azodicarbonamide blowing agents granulated glass flake extender for PU and epoxies high-whiteness marbleE ammonium polyphosphate flame retardants mould release agents Systems stabilizers phthaUc anhydride retardants flame retardants
DSM Great Lakes Owens Corning Chrostiki US Borax Great Lakes Laurel Industries Alcan Chemical Alcan Chemicals Inbra Industrias NGF Europe Monsanto CC Anzon Akzo-Nobel Frekote Ciba-Geigy Lonza Great Lakes Akzo-Nobel
G GADDS Garbefix Geniset Genitron Geode Getren Giadds Glicogum Glycolube Glycomul Glycosperse
modifiers for PVC, eng. plastics phosphite anti-oxidants nucleating agents blowing agents inorganic pigments release agents PVC modifiers, processing aids rubber auxiliaries lubricants/release agents emulsifiers, slip agents, dispersants PVC antistatic/anti-fog agents
Gharda Chemicals Great Lakes Hoechst Bayer Ferro Goldschmidt Gharda Chemicals Great Lakes Lonza Lonza Lonza
316
Additives for Plastics Handbook
Glycostat Granufin Grinitmast Grinitmicro Grinitpearl Grinitpulv Grinsted Mono Grinsted PGE Grinsted SMS Grit-0'Cobs GTY H Heliogen Hercules Hexafil Hexafort HiMod Hi-Sil Hispafos SP Hombitan Hordaresin Hostaflam Hostalub Hostamont Hostanox Hostaprime Hostastat Hostavin Hybon Hycite EXM Hydrosodium Hydrocarb Hydrocerol
I ICAliquid Iceberg Icecap K Idrosow Imicure Inbraflex Incoblend
anti-static, anti-fog microgranule carbon pigments pellet masterbatches micronized masterbatches microballoon masterbatches non-dusting powder masterbatches anti-static/cling agents polyglycerol ester anti-fog agent sorbitan ester antifog agent cellulose extender medium-size china clay
phthalocyanine pigments graphite fibres ball clays ball clays mica reinforcing silicas for rubber small particle zinc phosphate titanium dioxide pigments flame retardants FR agents waxes, lubricants release agents anti-oxidants coupling agents/compatibilizers antistatics HALS benzophenone stabilizers glass fibre roving stabilizers hydrosulphite ultrafine calcium carbonate blowing and nucleating agents
coupling agents calcined clays aluminium silicates colour pastes epoxy curing agents epoxidized soyabean oil concentrated conductive polymer
Lonza Brockhues Grinit Plast Grinit Plast Grinit Plast Grinit Plast Danisco Danisco Danisco Andersons ECC
BASF Hercules ECC ECC KMG Minerals PPG Colores Hispania Sachtleben Dover Hoechst Clariant Clariant Clariant Hoechst Clariant Clariant PPG Sud-Chemie Transpek Omya Boehringer Ingelheim
Kenrich Burgess Pigments Burgess Pigments Repi Air Products Inbra Industrias Zipperling Kessler
Appendix D: Trade Names
317
InFilm Intercide Interlite Interox Interstab Interwax Irgaclear Irgafos Irganox Irgasan Irgastat Irgazin
anti-blocking agents anti-microbial additives PVC stabilizers organic peroxides PVC stabilizers lubricants clarifying agents processing stabilizers anti-oxidants/heat stabilizers anti-microbials anti-static agents pigments
ECC Akcros Akcros Peroxid-Chemie Akcros Akcros Ciba Ciba Ciba Ciba Ciba Ciba
Jaycaswax 100 Jaycaswax Jaycopls Jaylubes Johoku UV
lubricants/dispersing agents lubricants, slip/anti-block agents coupling agents lubricants/anti-fogging agents UV absorber
Jayant Jayant Jayant Jayant Mitsui
K Kadox911
zinc oxide
Kane Ace Kane Ace-B Kane-Ace PA Kanstick Kapronet Kemgard Ken-React Ken-Stat Ketjen black EC Kevlar Ketjenblack Kosmos Kotamide Kronitex Kronos KSS
FM weather-resistant impact modifiers impact modifiers MMA processing aid for PVC external mould release agents purging compound zinc phosphates, silicates coupling agents coupling agents conductive carbon black aramid fibre special carbon black tin catalysts coated calcium carbonate natural phosphate flame retardants titanium dioxide flame retardant
Zinc Corp. of America Kaneka, Mitsui Kaneka, Mitsui Mitsui Specialty Products GE Plastics Sherwin Williams Kenrich Kenrich Akzo-Nobel DuPont Akzo Nobel Goldschmidt ECC Great Lakes Kronos Seal Sands
Lankroflex Lankromark
speciality plasticizers liquid PVC stabilizers
Akcros Akcros
Oil Mills Oil Mills Oil Mills Oil Mills
318
Additives for Plastics Handbook
Latha Lazer Flair Leucopur Levagard Lightfast Lipinol Listabmetal Lithol Lithopone Lonzacure Lonzest Lotader Lotryl Lowilite Lowin Loxamid Loxiol LSFR Lubriol Lubristat Lumogen Luperox Luzenac Lysopac
carbon black, activated carbon laser-marking additive optical brighteners flame retardants pigments viscosity depressant stearates pigments zinc sulphide pigments aromatic amine chain extenders sorbitan ester anti-static/anti-fog agents modifiers/processing aids EMA/EBA modifiers/processing aids light/UV stabilizers oxanti-oxidants lubricants, slip agents dispersing aids. low smoke flame retardant lubricants lubricant dyes organic peroxides talc organic pigments
Latha Chemical EM Industries Sarma Bayer Bayer Hills Chemson BASF Sachtleben Lonza Lonza Elf Atochem Elf Atochem Great Lakes Great Lakes Henkel Henkel Laurel Industries Comiel Comiel BASF Luperox Luzenac Cappelle
M Macrolex Magnesia Magnifin MagShield Marbocote Markep Marklube Markstab Markstab Markstat Martinal Masterad Mastersafe Mastertint Mastertint Matchwel MatVantage Maxithen Maxwhite
pigments magnesium oxide magnesium hydroxide FRs flame retardant release agents oxidized compounds, lubricants lubricants organic phosphites PVC liquid stabilizer anti-static agents aluminium trihydrate FRs anti-slip, anti-static masterbatch aluminium pigment concentrate pigment masterbatch colour masterbatches colour concentrates continuous strand mat colour masterbatches calcined china clay
Bayer Magnesia Lonza Martin Marietta Zychem Witco Witco Witco Witco Witco Lonza Chrostiki Obron Atlantic Chrostiki Krostiki Hawley PPG Gabriel 20 Microns
Appendix D: Trade Names
Mearlin Melax
lustre pigments mould conditioners, sealants
Menatalc Meramid, Arax Mesamoll Metablen Microglas Micron Microtalc Microtem Mikhart Mikrobrite Mikrofine
magnesium silicates rubber curing accelerators speciality plasticizers impact modifiers glass flake talc, barytes, calcium carbonate mirconized talc white calcite calcium carbonate calcined chalks additives
MikroXtra Millad Millicarb Minfil Miralex Mistron ZSC
calcined chalks clarifying agents for PP calcium carbonate white calcites twin-form glass fibre talc
Modifix Mogul Mold-Wiz
processing aids carbon black powder lubricants, release agents
Monarch Mono-Pak
carbon black powder additive packages
N Naftolube Naftomix Naftosafe Naftovin Neviflam Nevimaster Nevisylon Nicalon Norpol Noury
PVC lubricants stabilizer/lubricant systems stabilizer/lubricant systems heat/Ught stabilizers self-extinguishing masterbatches colour/additive masterbatches anti-sticking agent silicon carbide fibre resins, gelcoats, fillers bond adhesion promoters
Nourymix Nyad Nyglos Nylostab
additive concentrates woUastonite (untreated) ultrafine woUastonite light stabilizers
319
Mearl Axel Plastics Research Dorfner Great Lakes Bayer Elf Atochem NGF Europe 20 Microns 20 Microns Redland Provencale Faxe Kalk High Polymer Labs Faxe Kalk Milliken Omya Redland Owens-Corning CyprusInd Minerals Sarma Cabot Axel Plastics Research Cabot Catalyst Systems
Chemson Chemson Chemson Chemson Nevicolor Nevicolor Nevicolor Mitsui Jotun Polymer Air Products (prev. Akzo) Akzo Nobel Nyco Minerals Nyco Minerals Clariant
320
Additives fur Plastics Handbook
o Omya Omyalene Oncor Ongard Optiwhite Oracet Orevac Orgamin Ortegol
calcium carbonate dispersion agent flame retardants flame retardants calcined aluminium silicates polymer-soluble colorants modifiers/processing aids lead-free decorative pigments wetting/softening agents
Omya Omya Great Lakes Great Lakes Burgess Pigments Ciba Elf Atochem Colores Hispania Goldschmidt
P Paliotol Paraflint Paraloid Pationic Pepton Pergan Pergosperse Petcat Phthalotint Pionier Plasadd Plasblak Plasgrey Plastabil
pigments Fischer-Tropsch waxes MBS/acrylic impact modifiers internal lubricants peptizers organic peroxides polyethylene glycol dispersants polyester antimony catalyst pigment dispersions lubricants additive masterbatches black masterbatch grey masterbatch PVC stabilizers
Plastigel Plastipasta PlastiStab Plastolein Plastolor Plaswite Plaxter Polarite Polastech Polcarb PoleStar Polimix Polyace Polyad Polyaldo Polymekon Polymica Polyplastol
SMC/BMC thickeners pigment concentrates mixed metal heat stabilizers low-temperature plasticizers additive concentrates white masterbatch PVC polymeric plasticizers treated calcined clays technical masterbatch fine/ultrafine calcium carbonates calcined clays, metakaolin PVC plasticizers copolymers preblends polyglycerol ester dispersants EPS defoamers mica rubber processing promoters
BASF Schumann Sasol Rohm and Haas Patco Thomas Swan Pergan Lonza Laurel Industries Krostiki Dahleke Cabot Cabot Cabot Diadema Industrias Plasticolors Inducolor OM Group Henkel Plasticolors Cabot Coim ECC Cabot ECC ECC Lonza AlUedSignal Ciba Lonza Goldschmidt KMG Minerals Great Lakes
Appendix D: Trade Names
321
Polytint Polyvel Porofor PP1345
pigment concentrates melt flow modifiers, concentrates blowing agents chopped glass fibre for PA, PP
Preadd Prelux Premier Prestige Primax Primglos Priplast Pripol Pripol Pyro Chek
additives colour control system ultramarine pigments ultramarine pigments surface-modified UHMW PE ultrafine wollastonite PVC plasticizers, polyol additives dimer acid modifying agents polyurethane additives flame retardants
Krostiki Polyvel Bayer GlassTech Scandinavia Premix Oy ColorMatrix HoUiday Pigments Holliday Pigments Air Products Nyco Minerals Unichema Unichema Unichema Erbsloh
Ouartzel Oueensfil Quickset
fused quartz yarn chalk whitings MEKP
Quartz & Silice ECC Witco
R Rainbow Rakusol Reablend Reactint Readd Reaflakes Reagens Realube Rea-tin-or Recycloblend Regal Remap Reofos Reomol Repiplast Replas Repsil Reseda Reversacol Rhenodiv Rhodialux Rhodianox
coloured masterbatch liquid colours stabilizers, lubricants for PVC reactive colourants polyurethane adducts stabilizers, lubricants for PVC PVC additives lubricants organotin derivative stabilizers stabilizer systems for recycling carbon black powder and granule colour pastes (thermoplastics) phosphate flame retardants flame retardants colour pastes (PVC, PU) polymeric plasticizers colour pastes (silicon rubber) graft copolymer compatibilizer photochromic dyes release agents benzophone stabilizers phenolic antioxidants
Cabot BASF Reagens Milliken Townsend Reagens Reagens Reagens Reagens Ciba Cabot Repi Great Lakes Great Lakes Repi Townsend Repi Mitsui HolUday Chemical Rhein Chemie Great Lakes Great Lakes
0
322
Additives for Plastics Handbook
Ricinolts Ricon Riowax
stabilizers colorants rubber anti-degradants
Jayant Oil Mills Rite Systems Great Lakes
Sachtolith Safe FR 5000 Safoam Safolin Safolite Sandin Sandostab Sanduvor Sanduvor Sanitized Santicizer Sarmacal Sarmacarb Sarmaclean Sarmadrop Sarmaflam Sarmaglass Sarmagrip Sarmagum Sarmalube Sarmalyte Sarmamid Sarmapor Sarmastab Sarmastat Sarmastyr Sarmasyn Sarmatene Sarmatherm Sarmawax Secudur Secupurnu SecurocAFR: SecurocBFR: Securoc CFR: SecurocDFR: Securoc PBT/PP Securoc Polyamide Securoc Resin, Resin Plus
zinc sulphide pigments flame retardants chemical blowing agents zinc formaldehyde sulphoxylate sodium formaldehyde sulphoxylate anti-statics anti-oxidants light stabilizers UV stabilizer anti-microbial agents benzyl phthalate plasticizers calcium carbonate masterbatches colour masterbatches - PC purging agent anti-fogging masterbatch flame retardants colour masterbatches - PMMA anti-slip masterbatch colour masterbatches lubricant for polyamides anti-degradation masterbatches colour masterbatches - PA blowing agent masterbatch heat/light stabilizers anti-static agents colour masterbatches - PS colour masterbatches - PVC colour masterbatches - PO radiation barriers/UV stabilizers anti-slip/anti-blocking/lubricants synthetic woUastonite cleating/anti-blocking agents aluminium hydroxide magnesium hydroxide magnesium/calcium carbonate/hydrate magnesium/calcium carbonate FRforPBT,PP FR for polyamides
Sachtleben Uvitec Inc Reedy Intl Transpek Transpek Clariant Clariant Clariant Clairant Sarma Monsanto Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Sarma Incemin Incemin Incemin Incemin Incemin Incemin Incemin Incemin
FR for thermosets
Incemin
Appendix D: Trade Names
323
Selar Shawinigan Sicomin Sicopal Sicotan Sicotrans Silene Silstrip Slipwax Smokebloc Snowfort Sorbacid EXM Special Diamond Speswhite Sphericel Spheriglas Spinflam Spray-Lite Sprayset Stabilox Stabinex Stabiol Stabiol Star Stran Stat-Kon Stat-Rite Stockalite Stone-Tex Subar Suconox Sukano UV Sulfatran Superox Supreme Surfynol Synchnrolube Syncomat
barrier-forming additives conductive additive organic pigments pigments pigments pigments reinforcing silicas for rubber silicone solvent/remover mould release agents flame retardants calcium carbonate stabilizers additive dispersions ultrafine high-purity china clay hollow glass spheres solid glass spheres halogen-free flame retardants fillers dilute MEKP CaZn lead stabilizer for PVC aZn stabilizers lubricants glass reinforcement conductive compounds anti-static polymer additive alkaline high purity china clay granite effect fillers barium sulphate polyamide antioxidant masterbatches for PET accelerators, curing agents cure initiator ultrafine high-purity china clay surfactants fatty acid ester, stearic lubricants glass reinforcement
DuPont Shawinigan BASF BASF BASF BASF PPG Penn-White Diversey Great Lakes Croxton & Garry Sud-Chemie Chinghall ECC Potters-Ballotini Potters-Ballotini Montell Marshall Witco Henkel Mitsui Henkel Henkel SchuUer LNP Plastics BF Goodrich ECC Marshall Provencale Seal Sands Chemiehandel Transpek Reichhold ECC Air Products Croda Syncoplas
T Tafmer Tecfil Technora Tegiloxan Tego AB-M Tego Antiflamm
elastomer modifier for polyolefins ceramic microspheres aramid fibre release agents chemical blowing agents flame retardants
Mitsui Filtec Mitsui Goldschmidt Goldschmidt Goldschmidt
324
Additives for Plastics Handbook
Tego Conduct Ultra Tego Entschaumer Tego RC Tegoamin Tegocolor Tegokat Tegopren Tegosil Tegosipon Tegostab Tegotens Tegotrenn TekNeonLite Tenax Tersar Tersar ThermalGraph Thermoguard S Thermoplast Thornel Timonox Tinstab Tint-Ayd TinuvinUV Tinuvin TiONA Tital Topanol Tospearl Tracel Transcure Trapex Trawax Triacetin/Tegda Tudalen Turmosil Turmsilon Twaron Twintex
semiconducting tin dioxide PVC defoamer release coatings amine catalysts colour pastes glycerol fatty acid esters process auxiliaries release agents deaerators PU foam stabizers glycerol fatty acid esters release agents colorants carbon fibre colour masterbatches PET optical brightener carbon fibre antimony oxide dyes pitch-based carbon fibres antimony oxide PVC stabilizers (tin) pigment dispersions absorbers, HALS light/heat stabilizers titanium dioxide reinforcing filler anti-oxidants silicone anti-blocking agent blowing agents accelerators, curing agents lubricants, release agents lubricants, release agents plasticizers plasticizers silicone-free release agents/lubricant silicone release agents/lubricant aramid fibre commingled glass fibre
Goldschmidt Goldschmidt Goldschmidt Goldschmidt Goldschmidt Goldschmidt Goldschmidt Goldschmidt Goldschmidt Goldschmidt Goldschmidt Goldschmidt Teknor Color Akzo Sarma Sarma BP Amoco AtoChem BASF BP Amoco Anzon Akcros Daniel Products Ciba Ciba-Geigy SCM Chemicals Incemin Seal Sands GE Silicones Tramaco Transpek Tramaco Tramaco Bayer Dahleke Consult Consult Akzo Vetrotex
U Ultrafibe Ultrafine Ultramoll Unicell
surface-treated wollastonite antimony oxide FR plasticizers chemical blowing agents
Nyco Laurel Industries Bayer Tramaco
Appendix D: Trade Names
325
Unifilo Unimax Unimoll Uniplex Unislip United Unitex Univul Univul Univul Uniwax UV Chek Uvasil Uvitex
continuous strand glass mat colour concentrates plasticizers flame retardants slip/anti-block agents carbon black granule optical brighteners light stabilizers and anti-oxidants light stabilizers, UV absorbers light stabilizers, UV absorbers slip/anti-block agents light stabilizers HALS light/UV stabilizers optical brightening agents
Vetrotex Gabriel Bayer Unitex Corp Unichema Cabot Ciba BASF BASF BASF Unichema Erbsloh Great Lakes Ciba-Geigy
V Valu-Fil Variocrom Versicon Vetrotex Vibatan Vinylube Viscobyk Vulcabond Vulcan
calcium sulphate colour-variable pigments conductive polymer glass fibre range of additives ester anti-static/anti-fog/lubricants viscosity depressants for plastisols PVC bonding agents carbon black powder and granule
Marshall BASF Zipperling Kessler Vetrotex Viba Lonza Byk Chemie Akcros Cabot
W WG325 Wollastocoat
mica, wet-ground surface-modified wollastonite
KMG Minerals Nyco Minerals
X Xantrix
additive delivery systems
Montell
Y Y-200 YLO-2288D
high-conductivity acetylene black iron oxide, yellow
SN2A Pfizer
Zerogen 35
magnesium hydroxide
Solem Divn J M Huber
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APPENDIX E Directories Directory of suppliers
3M Specialty Fluoropolymers Department, 3M Center, Building 220-lOE-lO, St. Paul, MN 55144-1000, USA; tel: +1-612-733-6760; fax: +1-612-7377686 3M European Chemical Business Center, 3M (Antwerp) Belgium SA/NV, Canadastraat, B-2070 Zwijndrecht, Belgium; tel: +32-3-2 52-0711 3M Nederland BV, Industrieweg 24, NL-2382 NW Zoeterwoude, The Netherlands; tel:+31-75-5540-450; fax:+31-71-5540-212 A ABB Industry Oy, PO Box 184, FIN-00381 Helsinki, Finland; tel: +358-10-2223281; fax:+358-10-222-2681 ABB-IR Waterjet Systems AB, PO Box 2, Chorley New Road, Bolton BL6 6JN, UK ABC Group Ltd, 100 Ronson Drive, Rexdale, Ontario M9W 1B6, Canada; tel: + 1-416-246-1782; fax:+1-416-246-1552. Abril Industrial Waxes, Sturmi Way, Village Farm Industrial Estate, Pyle MidGlamorgan CF33 6NU, UK; tel: +44-1656-744-362; fax: +44-1656-742471 AC Technology Europe, PO Box 545, 7500 AM Enschede, The Netherlands; tel: + 31-53-836331; fax:+31-53-836332 Accrapak Systems Ltd, Burtonwood Industrial Centre, Warrington WA5 4HX, UK ACE Industrial Plastics Ltd, Brittania House, Lockway, Ravensthorpe Industrial Estate, Dewsbury, West Yorkshire WF13 3SX, UK; tel: +44-924-492244; fax:+44-924-490334 Acrison International, 20 Empire Boulevard, Moonachie, NJ 07074, USA; tel: + 1-201-440-8300; fax: +1-201-440-4939 Acrol Ltd, Everite Road, Ditton, Widnes WA8 8PT, UK; tel: +44-151-424-1341; fax:+44-151-495-1853 Additive Polymers Ltd, Unit 4 Kiln Road, Burrfields Road, Portsmouth P03 5LP, UK; teh+44-1705-678-575; fax:+44-1705-678-564 Addmix, Unit 20, Cygnus Business Centre, Dalmeyer Rd, London NWIO 2XA, UK; tel:+44-181-459-7477; fax:+44-181-459-7433
328
Additives for Plastics Handbook
Advanced Ceramics Corp, 11907 Madison Avenue, Lakewood, OH 44107, USA; tel:+1-215-529-3964; fax:+1-216-529-3954 Advanced Elastomer Systems NV/SA, Avenue de B(31e 1, Bazellaan, 1140 Brussels, Belgium; tel:+32-2-706-3311; fax:+32-2-76-3310 Advanced Elastomer Systems, 260 Springside Drive, Akron, OH 44334, USA; tel:+1-216-668-3763. Advanced Surface Technology Inc, 9 Linnell Circle, Billerica, MA 01821-3902, USA; tel: +1-508-663-7652; fax: +1-508-663-7746 AESJapan; tel:+81-3-3584-9341; fax:+81-3-3584-9342 Agema Infrared Systems Ltd, Arden House, Leighton Buzzard LU7 7DD, UK; tel:+44-1525-375660; fax:+44-1525-379271 Air Products and Chemicals de Mexico SA de CV, Rio Guadiana 23 piso 5, Colonia Cuauhtemoc, Mexico DF 06500, Mexico; tel: +52-5-546-7064/ 0415;fax:+52-5-592-3018 Air Products and Chemicals Inc, Polymer Chemicals, 7201 Hamilton Boulevard, AUentown, PA 18195-1501, USA; tel: +1-610-481-6799; fax: +1-610481-4381 Air Products Chemicals Division - Europe, PO Box 3193, NI-3502 GD Utrecht, TheNetherlands; tel:+31-30-285-7100; fax:+31-30-285-7111 Air Products pic, Hersham Place Molesey Road, Walton-on-Thames KT12 4RZ, UK; tel: +44-1932-249-273; fax: +44-1932-249-786 Airex AG Speciality Foams, Anglo-Swiss Aluminium Co Ltd, Mander House, Mander Centre, Wolverhampton WVl 3ND, UK; tel: +44-902-310610; fax:+44-902-29160. Airshrink Europe Ltd, Baird Court, Park Farm Industrial Estate, Wellingborough, Northamptonshire NN8 60J, UK; tel: +44-933-402977; fax: +44-933402144. Akcros Chemicals (Asia-Pacific) Ltd, 7500A Beach Road, Z 15-309 The Plaza, Singapore 199591; tel: +65-292-1966; fax: +65-292-9665 Akcros Chemicals America, 500 Jersey Avenue, PO Box 638, Nev^ Brunswick, NJ 0 8 9 0 3 , USA; tel: +1-908-247-2202; fax: +1-908-247-2287 Akcros Chemicals GmbH & Co KG, Kreuzauer Strafie 46, Postfach 100 146, D-52301Duren, Germany; tel:+49-2421-59502; fax:+49-2421-595191 Akcros Chemicals Ltd, PO Box 1, Eccles, Manchester M30 OBH, UK; tel: +44161-789-7300; fax:+44-161-788-7886 Akro-Plastik GmbH, Industriegebiet Scheid, D-56651 Niederzissen Postfach 67, Germany; tel: +49-2636-97-42-0; fax: +49-2636-97-42-31 Akzo Coatings Inc, 1696 Maxwell Street, Troy, MI 48084, USA; tel: +1-313649-3266; fax:+1-313-649-5256. Akzo Colour & Additive Concentrates, 2 rue de Tlndustrie, 5330 Assesse, Belgium; tel:+32-83-655021; fax:+32-83-656005 Akzo Nobel Casco Products Division Akzo Nobel NV, Velperweg 76, PO Box 9300, 6800 SB Arnhem, The Netherlands; tel: +31-26-366-4343; fax: +31-26-366-4940 Akzo Nobel Chemicals BV, Stationsplein 4, NL-3818 Amersfoort, The Netherlands; tel: +31-33-467-6767; fax: +31-33-467-6100
Appendix E: Directories
329
Akzo Nobel Faser AG, Accurel Systems, D-63 784 Oldenburg, Germany; tel: +496022-81-478; fax:+49-6022-81-823 Akzo Nobel NV, Velperweg 76, PO Box 9300, 6800 SB Arnhem, The Netherlands; tel:+31-26-366-4343; fax:+31-26-366-4940 Akzo-Nobel Polymer Chemicals, PO Box 247, 3800 AE Amersfoort, The Netherlands; tel:+31-33-467-767; fax:+31-33-467-6151 Albemarle Corp, 451 Florida Street, Baton Rouge, LA 70801, USA; tel: +1-504388-7040; fax: +1-504-388-7686 Albright & Wilson UK Ltd, Flame Retardants Plastics, PO Box 3,210-222 Hagley Road West, Oldbury, B68 ONN, UK; tel: +44-121-420-5312; fax: +44121-420-5111 Alcan Chemicals Europe, Chalfont Park, Gerrards Cross SL9 OQB, UK; tel: +441592-411-000; fax:+44-1753-233-444 Alcan Metal Centres, Birmingham New Road, Tipton DY4 9AG, UK; tel: +441902-880444; fax: +44-1902-880404 Alchemic Ltd, Brookhampton Lane, Kineton CV35 OJA, UK; tel: +44-1926-641600; fax: +44-1926-641-698 Allied Colloids Ltd, PO Box 38, Cleckheaton Rd, Low Moor, Bradford, West Yorkshire BD12 OJZ, UK; fax: +44-12 74-606499 AlliedSignal Europe NV, Performance Additives, Haasrode Research Park, B-3001 Heverlee, Belgium; tel: +32-16-391-210; fax: +32-16-391 371 AlliedSignal Inc, 101 Columbia Road, Morristown, NJ 07962-2245, USA; tel: + l - 2 0 1 455 2000; fax: +1-201-455-2288 AlliedSignal Inc, Engineered Materials, PO Box 1087, Morristown, NJ 079621087, USA; tel: +1-201-455-2000 AlliedSignal Inc, Fluorine Products, PO Box 108 7, Morristown, NJ 07962-108 7, USA; tel:+1-201-455-6073; fax:+1-201-455-2586 AlliedSignal Inc, High Performance Fibers, PO Box 3 1 , Petersburg, VA 23804, USA; tel: +1-804-520-3242 AlliedSignal Plastics, Haasrode Research Park, B-3001 Heverlee, Belgium; tel: + 32-16-391-320; fax: +32-16-400-103 Alpha Calcit FuUstoff GmbH & Co, KG, 5000 Koln 50, Postfach 1106, Germany; teh +49-2236-89-14-0; fax: +49-2236-40-644 AlphaGary Corp. (HO), 170 Pioneer Drive, Leominster, MA 0 1 4 5 3 , USA; tel: + 1 978-537-8071; fax:+1-978-840-0015 AmeriBrom Inc, 52 Vanderbilt Ave, New York, NY 10017, USA; tel: +1-212286-4000; fax: +1-212-286-4475 American Cyanamid Co, 1 Cyanamid Plaza, Wayne, NJ 07470, USA; tel: + 1-201-831-4619; fax:+1-201-831-2813 American Materials and Technologies (AMT), Los Angeles, Paul Pendorf; tel:+1-310-841-5200; fax:+1-310-837-2845 Americhem Inc, 225 Broadway E, Cuyahoga Falls, OH 4 4 2 2 1 , USA; tel: +1-216929-4213, fax+1-216 929 4144 Americhem Inc, Cawdor Street, Eccles, Manchester M30 OOF, UK; tel: +44-161789-7832;fax:+44-161-787-7832
330
Additives for Plastics Handbook
Amherst Process Instruments (Europe) Ltd, Mill Street, Tewkesbury GL20 5SB, UK; tel: +44-1684-291966; fax: +44-1684-293567 Amoco Chemical (Europe) SA, 15 Rue Rothschild, CH-1211 Geneva 2 1 , Switzerland; tel:+41-22-715-0701; fax:+41-22-738-8037 Amoco Chemical Belgium NV, Amocolaan 2, B-2440 Geel, Belgium; tel: +3214-86-43-45; fax: +32-14-86-73-72. Amoco Chemicals, Mail Code 7802, 200 East Randolph Drive, Chicago, IL 60601-7125, USA; tel:+1-312-856-3092; fax:+1-312-856-4151 Amoco Polymers Business Group, 4500 McGinnis Ferry Road, Alpharetta, GA 30205-2203, USA; tel: +1-770-772-8200; fax: +1-404-772-8547 Ampacet Corp, 660 White Plains Rd, Tarrytown, NY 10591, USA; tel: +1-914631-6600; fax:+1-914-631-7278 Ampacet Europe SA, Rued'Ampacet 1, Messancy B-6780, Belgium; tel: +32-6338-13-00;fax:+32-63-38-13-93 Ampacet Europe SA, Rue des Scillas 45, L-2529 Howald, Luxembourg; tel:+352-29-20-99-1; fax:+352-29-20-99-595 Amspec Chemical Corporation, Foot of Water Street, Gloucester City, NJ 08030, USA; tel: +1-609-456-3930; fax: +1-609-456-6704 Andersons, PO Box 119, Maumee, OH 43537, USA; tel: +1-419-891-6545; fax:+1-419-891-6539 Angus Chemical Co, 1500 E Lake Cook Rd, Buffalo Grove, IL 60089, USA; tel:+1-708-215-8600; fax:+1-708-215-8626 Anzon Inc, 2545 Aramingo Ave, Philadelphia, PA 19125, USA; tel: +1-215427-3000; fax:+1-215-427-6955 Anzon Limited, Cookson House, Willington Quay, Wallsend, Tyne and Wear NE26 6UQ, UK; tel:+44-191-262-2211, fax+44-191 263 4491 AP & T Ltd, Unit 11a, Talisman Business Centre, Bicester 0X6 OJX, UK API Spa, Via Dante Alighieri 27, 36065 Mussolente (Vi) Italy; tel: +39-424579-711; fax:+39-424-579-800 API SpA, Via Dante Alighieri 27,1-36065 Mussolente (Vi), Italy; tel: +39-424579-511;fax:+39-424-579-800 APV Baker Ltd, Industrial Extruder Division, Speedwell Road, Parkhouse East, Newcastle-under-Lyme ST5 7RG, UK; tel: +44-782-565656; fax: +44782-565800. Arco Chemical Inc, 3801 West Chester Pike, Newtown Square, PA 190732387,USA;tel:+1-215-359-2000; fax:+1-215-359-2722 Argus Chemical Co, 520 Madison Avenue, New York, NY 10022, USA; tel: + 1 212-605-3600 Aristech Chemical Corporation, PO Box 2219, 600 Grant St, Pittsburgh, PA 15219, USA; tel: +1-412-433-7800; fax: +1-412-433-7721 Asahi Chemical Industry Co Ltd, Hibiyamitsui Building, 1-1-2, Yaraku-cho, Chiyoda-ku, Tokyo 100, Japan; teh +81-3-3507-2730; fax: +81-3-35072005 Asahi Denka Kogyo KK, Furukawa Building 3-14, Nihonbashi-Muromachi 2-chome,Chuo-ku, Tokyo 103, Japan; tel:+81-3-5255-9017; fax:+81-33270-2463
Appendix E: Directories
331
Ashland Chemical Co, Box 2219, Columbus, OH 43216, USA; tel: +1-614-8894191;fax:+l-614-889-3735 Ashland Chemical Co, Composite Polymers Division, 5200 Blazer Parkway, Dublin, OH 43017, USA; tel: +1-614-790-3445; fax: +1-614-790-3503 Ashland Chemical Inc, PO Box 2219, Columbus, OH 43216, USA; tel: +1-614889-3333; fax:+1-614-889-3503 Ashley Polymers Inc, 5114 First Hamilton Parkway, Brooklyn, NY 11219, USA; tel:+l-718-851-8111;fax:+1-718-972-3256 ASM International, Materials Park, OH 44073-0002, USA; tel: +1-216-3385151; fax:+1-216-338-4634 Aspanger Geschaftsbereich, Jungbunzlauer GmbH, A-2870 Aspang, Postfach 32, Austria; tel:+43-2642-52355; fax:+43-2642-52673 Astab, c/o Croxton & Garry Ltd, Curtis Road, Dorking RH4 IXA, UK; tel: +441306-886-688; fax:+44-1306-887-780 Aston Industries Ltd, 38 Nine Mile Point Ind. Estate, Crosskeys NPl 7HZ, UK; tel: +44-1495-200-666; fax: +44-1495-200-616 Astor Wax Corp, 200 Piedmont Court, Doraville GA 30340, USA; tel: +1-404448-8083 Asiia Products SA, Ctra Sangroniz 20, E-48150 Soldica (Bilbao), Spain; tel: +344-453-16-50; fax: +34-4-453-35-66 Asua Products, Ctra. Sangroniz 18-20, 4 8 1 5 0 Sondica (Vizcaya), Spain; tel: +34-9-4453-5206; fax: +34-9-4453-3566 ATEM, Via Modena, Angolo Piazza Milano, 24040 Zingonia Ciserano, Italy; tel:+39-35-883255;fax:+39-35-885131 Atlanta, GA 30339, USA; tel:+1-404-951-5700 Atlas SETS BV, BaumstraSe 39, D-47198 Duisburg, Germany; tel: +49-2066560-34; fax: +49-2066-106-19 Avon Rubber pic, Bradford-on-Avon, Wiltshire, UK; tel: +44-1225-861-100; fax:+44-1225-861-199 Axel Plastics Research Laboratories Inc, Box 77 0855, Woodside, NY 11377, USA; tel: +1-718-672-8300; fax: +1-718-565-7447 Axon AB Plastics Machinery, S-265 39 Astorp, Sweden; tel: +46-42-570-80; fax:+46-42-541-52
B BA Chemicals Ltd, Chalfont Park, Gerrards Cross, Bucks SL9 OQB, UK; tel: +441735-887373, fax+44-1753 889602 Barco NV Automation, Kennedypark 35, 8500 Kortrijk, Belgium Barlocher GmbH, RiesstraKe 16, D-80992 Munchen, Germany; tel: +49-89-1437-30,fax+49-89 14 37 33 12 Barlocher USA, West Davis St, PO Box 545, Dover, OH 44622, USA; tel: +1-216364-4000; fax: +1-216-343-7025 Barmag AG, Leverkuser StraEe 65, D-42897 Remscheid, Germany; tel: + 4 9 - 2 1 9 1 - 6 - 7 0 , f a x + 4 9 - 2 1 9 1 6 7 1 7 38
332
Additives for Plastics Handbook
BASF AG, 67056 Ludwigshafen, Germany; tel: +49-621-600; fax: + 4 9 - 6 2 1 602-0129 BASF Corporation, Colorants and Additives for Plastics, 3000 Continental Drive North Mount Olive, NJ 07828, USA; tel:+1-201-426-2600 Battenfeld Gloenco Extrusion Systems, Berry Hill Industrial Estate, Droitwich, Worcs.WR9 9RB, UK; tel:+44-1905-775611, fax+44-1905-776716 Battenfeld Holding GmbH, Scherl 10, Postfach 1164/65, D-5882 Meinerzhagen, Germany; tel: +49-2354-720; fax: +49-2354-72565 Baxenden Chemicals Ltd, Applied Chemicals Division, Union Lane, Droitwich WR9 9BB, UK; tel: +44-1905-794795; fax: +44-1905-794002 Baxenden Chemicals Ltd, Speciality Chemicals Division, Paragon Works, BaxendenBB5 2SL, UK; tel:+44-1254 872278; fax:+44-1254 8 7 1 2 4 7 Bayer AG, Bayerwerk, D-51368 Leverkusen, Germany; tel: +49-214-30-1, fax +49-214 30-7407 Bayer AG, D-51368 Leverkusen, Germany; tel: +49-214-30-1; fax: +49-21430-8923 Bayer Corp, 100 Bayer Road, Pittsburgh, PA 15205-9741, USA; tel: +1-412777-2000 BayerLtd,Tokyo,Japan; tel:+81-3-3280-9785; fax:+81-3-3280-9789. BBU, Bleiberger Bergwerks Union AG, RadetzkystraEe 2, Postfach 95, A-9010 Klagenfurt, Austria; tel: +43-42-22-555-25 Bekaert NV, SA, Bekaert straat 2, B-8550 Zwevegem, Belgium; tel: +32-56230511; fax:+32-56-230585 Berga Kunststoffproduktion, mbH & Co KG, Thyssen Strafie 19-21, D-1000 Berlin 51, Germany; tel: +49-330-414-3030; fax: +49-330-41440-95 Hermann Berstorff Maschinebau GmbH, Karen Scheffel, Hannover, Germany; tel:+49-511-57-02-397;fax:+49-511-56-19-16 BI Chemicals Inc Henley Division, 50 Chestnut Ridge Road, Montvale, NJ 07645, USA; tel: +1-201-307-0422; fax: +1-201-301-0424 BICC Compounds, BICC Cables Ltd, Leigh, Lancashire WN7 4HB, UK Biesterfeld Plastic GmbH, FerdinandstraKe 4 1 , D-20095 Hamburg, Germany; tel: +49-40-3-20-08-0; fax: +49-40-3-20-08-442 Bio-Tek Kontron Instruments Ltd, 8 Marlin House, Croxley Business Park, Watford, WD18YA, UK; tel:+44-1923-691300; fax:+44-1923-691301 BIP Chemicals Ltd, PO Box 6 Popes Lane, Oldbury, Warley, W Midlands B69 4PD, UK; tel:+44-121-551-1551; fax:+44-121-552-4267 Blackfriars Ltd, 5 Roman Way, Market Harborough, LE 16 7P0, UK; tel: +441858-462249; fax: +44-1858-464755 Blancs Mineraux de Paris (BMP), 40 rue des Vignobles, F-78402 Chatou Cedex, France; tel: +33-1-39-52-32-63; fax: +33-1-30-71-46-83 BMBiraghi SpA, ViaErcolano 11,1-20052 Monza, Italy; tel: +39-83-31-31; fax: + 39-2-84-09-15 BOC Gases, The Priestley Centre, Surrey Research Park, Guildford GU2 5XY, UK; tel:+44-1483-244-116; fax:+44-1483-244-658 Bock, Otto, Kunststoff GmbH & Co, IndustriestraEe Postfach 12 60, D-3408 Duderstadt, Germany; tel:+49-55-27-82-1; fax:+49-55-27-823-80
Appendix E: Directories
333
Boehringer Ingelheim KG, Geschaftsgebeit Chemikalien, D-55216 Ingelheim, Germany; tel:+49-6132-77-38-73; fax:+49-6132-77-46-17 Bohlin Instruments Ltd, Unit 6 The Corinium Centre, Cirencester GL7 lYJ, UK; tel:+44-1285-644407; fax:+44-1285-644314 Bollore Technologies, Industrial Division, BP 29111 Scaer, France; tel: +33-9859-4038 Boy Ltd, 60-70 Tanners Drive, Blakelands, Milton Keynes MK14 5BP, UK; tel: +44-908-613916; fax: +44-908-216401 Brabender Instruments Inc, 50 East Wesley Street, South Hackensack, NJ 07606, USA; teh +1-201-343-8425; fax: +1-201-343-0608 Brabender Technologic KG, KulturstraBe 55-73, PO Box 35 01 38, D-47032 Duisburg, Germany; tel: +49-203-9984-0; fax: +49-203-9984-164 Brampton Engineering Inc, 8031 Dixie Road, Brampton, Ontario, Canada L6T 3Vl;teL+1-905-793-3000; fax:+1-905-793-1753 Branco Industria e Comercio Ltda, Rua Manoel Pinto de Carvalho 229, CEP 02712-120 Sao Paulo SP, Brasil; tel: +55-11-265-8666; fax: + 5 5 - 1 1 872-3735 British Technology Group Ltd, 101 Newington Causeway, London SEl 6BU, UK; tel:+44-171-403-6666; fax:+44-171-403-7586 Britton's Plastics Ltd, Westwood Road, Witton, Birmingham B6 7JE, UK; tel:+44-21-327-0436; fax:+44-21-322-2285 Brockhues AG, D-65396 Walluf, Muhlstrafie 118, Germany; tel: +49-6123-797-403; fax: +49-6123-797-418 Bronkhorst High-Tech BV, Nijverheidsstraat lA, 7261 AK Ruurlo, The Netherlands; tel:+31-573-458800; fax:+31-573-458808 Brookhouse Patterns Ltd, India Mill, Darwen, BB3 IAD, UK; tel:+44-1254 706000 Brown Machine Divn, John Brown Plastics Machinery Ltd, 681 Mitcham Road, Croydon, CR9 3AP, UK; tel: +44-181-684-9082; fax: +44-181-684-9070 Brush Wellman Ltd, Units 4&5, Ely Road, Theale Commercial Estate, Reading RG7 4BQ, UK; tel: +44-734-303733; fax: +44-734-303635 BTG British Technology Group Ltd, 101 Newington Causeway, London SEl 6BU,UK;teL+44-171-403-6666;fax:+44-171-403-7586 BTR Fluoroline, BTR Silvertown Ltd, Horninglow Road, Burton on Trent, Staffs DE13 0SN,UK;teL+44-1283-510510; fax:+44-1283-510113 Buhler Kunststoffe Farben u Additive GmbH, Ritzenschattenhalb 1, D-87480 Weitnau, Germany; tel: +49-8375-920-10; fax: +49-8375-920-130 Burgess Pigments Inc, PO Box 349, Sandersville, GA 31082, USA; tel: +1-912552-2544; fax:+1-912-552-1772 Bush Boake Allen, Terpene Products, Dans Road, Widnes WAS ORE, UK; tel:+44-151-423-3131; fax:+44-151-424-3268 Busing & Fasch GmbH & Co, Abt. Kunststoffe, Cloppenburger StraEe 13 8-140 Buss AG, Basel, CH-4133 Pratteln 1, HohenrainstraEe 10, Switzerland; tel: + 4 1 61-8256-111, fax+41-61-8256-699 Byk-Chemie GmbH, AbelstraSe 14, Postfach 10 02 45, D-46483 Wesel, Germany; tel: +49-281-6-70-0; fax: +49-281-6-82-45
334
Additives for Plastics Handbook
Byk-Chemie USA, 524 South Cherry St, PO Box 5670 Wallingford, CT 06492 USA; tel: +1-203-254-2086; fax: +1-203-284-9158
C Cabot Corporation, Special Blacks Division, 157 Concord Rd, Billerica, MA 0 1 8 2 1 , USA; tel: +1-508-670-7042 Cabot Plastics International, Interleuvenlaan 5, 3001 Leuven, Belgium; tel:+32-16-3901-ll;fax:+32-16-4012-53 Cabot Plastics International, rue E Vandervelde 131, B-4431 Ans/Loncin, Belgium; tel:+32-41-46-82-11; fax:+32-41-46-54-99 Cairn Chemicals Ltd, Cairn House, Elgiva Lane, Chesham HP5 2JD, UK; tel: +441494-786-066; fax: +44-1494-791-816 Campine America Inc, 3676 Davis Road, PO Box 526, Dover, OH 44622, USA; tel:+l-216-364-8533;fax:+1-216-364-1579 CEI-Europe, PO Box 910, S-612 2 5 Finspong, Sweden; tel: +46-122-17570; fax: +46-122-14347 Celanese GmbH, Lurgiallee 14, D-60439 Frankfurt, Germany; tel: +49-69-30582319;fax:+49-69-31-7295 CEM, 3100 Smith Farm Road, PO Box 200, Matthews, NC 28106-0200, USA; tel:+l-704-821-3331;fax:+1-704-821-7894 Cerdec Corporation Drakenfeld Products, West Wylie Avenue, PO Box 519, Washington PA 15301, USA; tel: +1-412-223-5900; fax: +1-412-2283170 Certainteed Corporation - FRD, PO Box 860, Valley Forge, PA 19482, USA; tel:+1-215-341-7770; fax:+1-215-293-1765 CFB pic, CFB House, 8-10 Malew Street, Castletown, Isle of Man IM9 lAB, UK; tel:+44-1624-825472; fax:+44-1624-825660 Chapman and Hall, 2-6 Boundary Row, London SEl 8HN, UK; tel: +44-71-5229966; fax: +44-71-522-9623. Chavanoz Industrie, BP 56, 38232 Pont de Cheruy Cedex, France; tel: +33-47246-7900; fax: +33-4-7202-3887 Chemax Inc, Box 6067 Greenville, SC 29606, USA; tel: +1-803-277-7000; fax: 1-803-277-7807 Chemiehandel SE AG, PO Box, CH-8834 Schindellegi, Switzerland; tel: +41-1785-0949; fax: +41-1-785-0143 Chemische Werke Lowi GmbH, Teplitzer Strafie, Postfach 16 60, D-8264 Waldkraiburg, Germany; tel: +49-86-38-4011; fax: 49-86-819-42 Chemoxy International pic, All Saints Refinery, Cargo Fleet Road, Middlesbrough TS3 6AF, UK; tel: +44-642-248555; fax: +44-642-244340 Chemson GmbH, Trakehner Strage 3, D-60487 Frankfurt/Main, Germany; tel: +49-69-7165-0; fax: +49-69-7165-2236 Chemson Ltd, Northumberland Dock Rd, Wallsend NE28 OPB, UK; tel: +44-191258-5892; fax: +44-191-296-1466
Appendix E: Directories
335
Chemson Polymer-Additive Gesellschaft mbH, Gailitz 195, A-9601 Arnoldstein, Austria; tel: +43-4255-2226; fax: +43-4255-2435 Chesterfield S41 9QB, UK; tel: +44-1246-260-222; fax: +44-1246-455-420 Chevron Chemical Co, Olefins and Derivatives Division, PO Box 3766, Houston, TX 77253, USA; tel: +1-713-754-2000 ChinghallLtd, Ward Road, Bletchley, MKl IJA, UK; tel: +44-1908-76227 Chromatics Inc, USA; tel; +1-203 743 6868; fax: +1-203-743-1102 Chronos Richardson Ltd, Arnside Road, Bestwood, Nottingham NG5 5HD, UK; tel:+44-115-9835-1351; fax:+44-115-960-6941 Chrostiki, PO Box 22, 194 00 Koropi, Greece; tel: +30-1-6624-692; fax: 30-16623-873 Chuo Kagaku Co Ltd, 3-5-1, Miyagi, KonosuCity, Saitana Prefecture 365, Japan; teL+81-485-42-8631;fax:+81-485-43-3258 Ciba Additive GmbH, PO Box 1640, D-68619 Lampertheim, Germany; tel: +496206-5020; fax:+49-6206-5021-368 Ciba Additives, Hulley Road, Macclesfield SKIO 2NX, UK; tel: +44-1625665000; fax: +44-1625-502-674 Ciba Specialty Chemicals Corp, 540 White Plains Road, PO Box 2005, Tarrytown, NY 10591-9005, USA; teh +1-914-785-2000 Ciba Specialty Chemicals Corp, Pigments Division, 205 South James Street, Newport, DE 19804-2490, USA; tel: +1-302-633-2000 Ciba Specialty Chemicals, PO Box, CH-4002 Basel, Switzerland; tel: +41-61696-3478; fax: +41-61-696-3019 Ciba-Geigy (Japan) Ltd, 10-66 Miyuki-cho, Takarazuka-shi, Hyogo 665, Japan; tel/fax:+81-797-74-2472 Ciba-Geigy Corporation, Chemicals Division, 410 Swing Road, Greensborough, NC 27409-2080, USA; tel: +1-919-632-6000; fax: +1-919-632-7008 Cincinnati Milacron Austria, Laxenburger StraSe 246, A-1239 Wien, Austria; tel: +43-1-61006-267; fax: +43-1-61006-288 Cincinnati Milacron UK Ltd, Plastics Machinery Division, PO Box 505, Kingsbury Road, Birmingham B24 OOU, UK; tel: +44-21-351-5719; fax: +44-21-313-1966 Cincinnati Milacron, Plastics Machinery Division, 4165 Halfacre Road, Batavia, OH45103,USA;tel:+1-513-536-2000; fax:+1-513-536-2552 Cinpres Ltd, Apollo, Lichfield Road Industrial Estate, Tamworth B79 9TA, UK; tel:+44-827-55559; fax:+44-827-53558 CJC Napier Ltd, Unit 3 7, Enterprise City, Green Lane, Spennymoor DLl 6 6JF, UK; t e h + 4 4 - 3 8 8 - 4 2 0 7 2 1 ; fax:+44-388-420718 Clariant Corp, 4000 Monroe Road, Charlotte, NC 28205, USA; tel: +1-704-3317029; fax:+1-704-331-7112 Clariant GmbH, Pigments and Additives Division, Am Unisys-Park 1, 65843 Sulzbach, Germany; teh+49-6196-757-8130; fax:+49-6196-757-8862 Clariant International, RothausstraEe 6 1 , CH-4132 Muttenz 1, Switzerland; tel: +41-61-469-6969; fax: +41-61-469-6999 Clariant Masterbatches Division, Ave de Bpie, BP 149, F-68331, Huningue, France; tel: +33-3-8989-6000; fax: +33-3-8989-6290
336
Additives for Plastics Handbook
Climax Molybdenum Co, 2275 Swallow Hill Road Building 900, Pittsburgh, PA 15220-1672,USA;tel:+1-412-279-4200; fax:+1-412-279-4710 Coatex, 35 rue Ampere, ZILyonNord, F-6972 7, Genay Cedex, France; tel: +3372-08-2000; fax: +33-72-08-2040 COIM SpA, 1-20019 Settimo Milanese (MI), Via A Manzoni 28, Italy; tel: +39-233505-1; fax: +39-2-33505-249 Colloids Ltd, Dennis Road, Widnes WA8 OSL, UK; tel: +44-151-424-7424; fax: +44-151-495-1715 Color System SpA, Via S. Quasimodo 9, 1-20025 Legnano (Mi), Italy; tel: +39331-577-607; fax:+39-331-464-248 Colorant Chromatics AG, Switzerland; tel: +41-41-741-0101; fax: +41-41741-0102 Colorant GmbH, Justus-Staudt-StraKe 1, D-6250 Limburg-Offheim, Germany; tel:+49-6431-53391 Color-Chem International Corp, 8601 Dunwoody Place, Bldg 334, Atlanta, GA 30350, USA; tel: +1-770-993-5500; fax: +1-770-993-4780 Colores Hispania, Josep Pla 149, Barcelona 08019, Spain; tel: 34-3-307-1350; fax:+34-3-303-2505 Colores y Compuestos Plasticos SA, C/Fedanci, 8 al 10 bajos 2^, Pare Empresarial ColorMatrix Europe Ltd, Unit 9 Unity Grove, Knowsley Industrial Park South, Knowsley L34 9GT, UK; tel: +44-151-548-3100; fax: +44-151-5483800 Color-Plastics-Chemie, Postfach 12 05 10, D-5630 Remscheid 11, Germany; tel:+49-2191-530-059; fax:+49-2191-516-95 Color-Service GmbH, Offenbacher Landstrafie 107-109, D-63512 Hainburg/ Hess, Germany; tel: +49-6182-4034-37; fax: +49-6182-668-86 Colortech Inc, 5712 Commerce Boulevard, Morristown, TN 37814, USA; tel: + 1-905-792-0333; fax:+1-905-792-8118 Colortronic (UK) Ltd, Matilda House, Carrwood Road, Chesterfield Industrial Estate Columbian Chemicals Co, 1600 Parkwood Circle, Suite 400 Comiel SpA, Via Bessarione 1, 1-20139 Milano, Italy; tel: +39-2569-341; fax: + 39-2569-181 Compounding Technology AG, Baumgartenweg 4, CH-4106 Therwil (Basel), Switzerland; tel: +41-61-722-0526; fax: +41-661-722-0529 Conair Europe Ltd, Riverside Way, Uxbridge UBS 2YF, UK; tel: +44-895850500; fax: +44-895-850555 Condux, Maschinenbau GmbH & Co, Rodenbacher Chaussee 1, D-6450 Hanau 11, Germany; tel:+49-6181-50601; fax:+49-6181-571270 Constab Polymer-Chemie GmbH & Co, Mohnetal 16 Postfach 112 7, D-59602 Ruthen/Mohne, Germany; tel: +49-2952-8190; fax: +49-2952-3140 Continent Machinery Industries, No 5 Ching Pu Tsuen, Liou Chia Hsiang, Tainan, Taiwan; tel: +886-6-698-6666; fax: +886-6-698-6238 Cookson Pigments Inc, 56 Vanderpool Street, Newark, NJ 07114, USA; tel: + 1 201-242-1800; fax: +1-201-242-7274 Cookson Plastics Ltd, Uttoxeter Road, Meir, Stoke-on-Trent ST3 7YA, UK; tel:+44-1782-599-111; fax:+44-1782-312-409
Appendix E: Directories
337
Cookson Specialty Additives, 1000 Wayside Road, Cleveland, OH 44110, USA; tel:+1-216-531-6010; fax:+1-216-486-6638 Corduplast GmbH, Postfach 1227, D-4417 Althenberge, Germany; tel: +492505-2186 Costenoble GmbH, Postfach 5205, D-6236 Eschborn, Germany; tel: +49-6196440-20; fax: +49-6196-481-283 CPM GmbH, Werner-von-Siemens-StraEe 19, D-49124 Georgsmarienhutte, Germany; tel: +49-5401-82940; fax: +49-5401-8294-29 Cp-Polymer-Technik, Berliner StraKe 3-5, D-2863 Ritterhude, Germany; tel: +49-4292-1034 Cristal, National Titanium Dioxide Co Ltd, PO Box 13586, Jeddah 21414, KingdomofSaudiArabia; tel:+966-2-651-9883; fax:+966-2-651-8757 Croda Universal Inc, 4014 Walnut Pond Drive, Houston, TX 77059, USA; tel: +1-713-282-0022; fax: +1-713-282-0024 Croda Universal, Division of Croda International pic, Cowick Hall, Snaith, Goole DN14 9AA, UK; tel: +44-1405-860551; fax: +44-1405-860205 Crompton & Knowles Corp, PO Box 33188, Charlotte, NC 2 8 2 3 3 , USA; tel: + 1 704-372-5890; fax:+1-704-372-1522 Crowley Chemical Co Inc, 261 Madison Ave, New York, NY 10016, USA; tel: + 1 212-682-1200; fax: 1-212-953-3487 Croxton & Garry Ltd, Curtis Road, Dorking RH4 IXA, UK; tel: +44-1306-886688; fax: +44-1306-887-780 CT Compounding Technology AG, Baumgartenweg 4 Postfach, CH-4106 Therwil (Basel), Switzerland; tel: +41-61-7220-526; fax: +41-61-7220529 C-Tech Corporation, 5-B, 5th Floor, Himgiri 12 77 Hatiskar, Marg, Mumbai 400 025, India; tel: +91-22-422-5939; fax: +91-22-430-9295 Cytec Industries Inc, Five Garret Mountain Plaza, West Paterson, NJ 07424, USA; tel:+1-201-357-3100
D Daicel Chemical Industries, 1, Teppo-cho, Sakai-shi, Osaka 590, Japan; tel: + 8 1 722-27-3111;fax:+81-722-27-3000 Dai-ichi Kogyo Seiyaku Co. Ltd, New Kyoto Center Building, 614 Higashishiokoji-cho, Shimukyo-ku, Kyoto 600, Japan; tel: +81-75-3431181;fax:+81-75-343-1421 Dainippon Ink & Chemicals Inc, 3-7-20, Nihonbashi, Chuo-ku, Tokyo 103, Japan;tel:+81-3-3272-4511;fax:+81-3-3278-8558 Daltex Medical Sciences Inc, 50 Kulick Road, 2nd Floor, Fairfield, NJ 07004, USA; tel: +1-201-227-5066; fax: +1-201-227-6339 Daniel Products Co Inc, 400 Claremont Ave, Jersey City, NJ 07304, USA; tel: + 1 201-432-0800; fax: +1-201-432-0266 Danisco Ingredients, Edwin Rahrsvej 38, Brabrad DK-8220, Denmark; tel: +4589-43-5000; fax: +45-86-25-1077
338
Additives for Plastics Handbook
Datacolor International, 6 St Georges Court, Dairyhouse Lane, Altrincham WA14 SUA, UK; tel: +44-161-929-9441; fax: 44-161-929-9059 Davis Standard Asia, Room 1211 Peninsula Centre, 6 7 Mody Road, Tsimshatsui Kowloon, Hong Kong; tel: +852-2-723-1787; fax: +852-2-724-4263 Davis-Standard Compounding Systems, 1 Extrusion Drive, Pawcatuck, CT 06379, USA; tel: +1-203-599-1010; fax: +1-2-3-599-6258 Davis-Standard Europe, Tricorn House, Cainscross Stroud GL5 4LF, UK; tel:+44-1453-765-111; fax:+44-1453-750-819 Davy Process Technology, 68 Hammersmith Road, London W14 8YW, UK; tel: +44-71-603-6633; fax: +44-71-872-8741 DBL International Inc, Nijvelsebaan 9 1 , B-Overijse, Belgium; tel: +32-2-6880782; fax: +32-2-646-4677 DCE Limited, Humberstone Lane, Thurmaston, Leicester LE4 8HP, UK; tel: +44116-269-6161 Dead Sea Bromine Compounds, PO Box 180, beer Sheva 8 4 1 0 1 , Israel; tel:+972-7-297-265; fax:+972-7-280-444 Decillion LLC, c/o Owens Corning World HQ, Fiberglas Tower, Toledo, OH 43659, USA; tel: +1-419-248-8000 Degussa AG, GB Anorganische, Chemieprodukte (AC-KP), D-60287 Frankfurtam-Main, Germany; tel: +49-69-218-01; fax: 49-69-218-3218 Degussa-Hiils AG, WeiSfrauenstraKe 9, D-60287 Frankfurt-am-Main, Germany; tel: +49-69-218-2055; fax: +49-69-218-3743 Deltacolor SA, Delta Tecnic SA, Poligono Industrial Moli de les Planes - c/Rec Moli de les Planes, s/n, 08470 Sant Celoni (Barcelona), Spain; tel: +34-93867-4284; fax: +34-93-867-5229 Denko Kagaku Kogyo Co Ltd, Sanshin Building, 1-4-1, Yuraku-cho, Chiyoda-ku, Tokyo 100, Japan; tel: +81-3-3507-5032; fax: +81-3-3508-2739 Department of Trade and Industry, 1 Victoria Streeet, London SWIH OET, UK; tel:+44-171-215-5000;fax+44-171 215 6740 Desco Industries Inc, 761 Penarth Avenue, Walnut, CA 91789, USA; tel: + 1 909-598-2753; fax: +1-909-595-7028 Diadema Industrias Quimicas Ltda, Av Fagundes de Oliveira 190, Piraporinha Diadema,SP 09950-907, Brazil; tel:+55-11-745-4133; fax:+55-11-7462011 Diversey Ltd, Waston Favell Centre, Northampton NN3 4PD, UK; tel: +44-1604405-311 DJ Enterprises Inc, Box 31366, Cleveland, OH 44131-0366, USA; tel: +1-216524-3879 Doeflex pic, Holmethorpe Avenue, Redhill, Surrey RHl 2NR, UK; tel: +44-73 7771221;fax:+44-737-772461 Dover Chemical Corp, ICC Industries Inc, 3676 Davis Rd NW, PO Box 40, Dover, OH 44622, USA; tel:+1-216-343-7711; fax:+1-216-364-1579 Dover Chemical Ltd, Amsteldijk 166, NL-1079 LH Amsterdam, The Netherlands Dow Chemical Co, 2040 Dow Center, Midland, MI 46874, USA; tel: +1-517636-2303;fax:+1-517-638-9752
Appendix E: Directories
339
Dow Corning Europe, Rue General de Gaulle 62, B-1310 La Hulpe, Belgium; tel: 32-2-655-2111; fax:+32-2-655-2001 Dow Corning GmbH, SchoSburgstraBe 24, D-65201 Wiesbaden, Germany; tel:+49-611-928-630; fax:+49-611-246-28 Dow Europe SA, BachtobelstraSe 3, PO Box, CH-8810 Horgen, Switzerland; tel:+41-l-728-2111;fax:+41-1-728-2935 Dow Information Centre, Schurenbergweg 5, 1105 AP Amsterdam-Zuidoost, TheNetherlands; tel:+31-2069-16268 Dow Plastics, 26200 American Drive, Southfield, MI 48034, USA; tel: +1-313358-1300; fax:+1-313-948-1708 DSM NV, PO Box 6500, 6401 JH Heerlen, The Netherlands; tel: +31-45-5782422; fax: +31-45-574-0680 DSM Performance Polymers BV, PO Box 43, 6130 AA Sittard, The Netherlands; tel:+31-46-477-3965; fax:+31-46-477-0070 DSM Resins, PO Box 615, Zwolle NL 8000, The Netherlands; tel: +31-38-284911;fax:+31-38-284-284 Du Pont (UK) Ltd, Maylands Avenue, Hemel Hempstead HP2 7DP, UK; tel: +44442-218500; fax: +44-442-249463. DuPont Asia Pacific Ltd, 1122 New World Office Building, East Wing, Salisbury Road, Kowloon, Hong Kong; tel: +852-734-5345; fax: +852-724-4458 DuPont de Nemours & Co, 1007 Market Street, Wilmington, DE 19898, USA; tel: +1-302-774-1000; fax: +1-302-774-7321 DuPont de Nemours (Luxembourg) SA, Specialty Chemicals, L-2984 LuxembourgContern, Luxembourg; tel: +352-3666-5646; fax: +352-3666-5015 DuPont de Nemours International SA, Chemin du Pavilion 2, PO Box 50, CH-1218 Le Grand-Saconnex, Switzerland; tel: +41-22-717-5111; fax:+41-22-717-5109 DuPont Dow Elastomers, CH-1218 Le Grand-Saconnex, Switzerland; tel: + 4 1 22-717-5111; fax:+41-22-717-5109 DuPont Far East Inc, Kowa Building No 2, Akasaka 1-chome, Minato-ku, Tokyo 107,Japan;teL+81-585-5511 DuPont Japan Ltd, Shin Nikko Building, Du Pont Tower, 2-10-1, Toranomon, Minato-ku, Tokyo 105, Japan; tel: +81-3-3585-5511; fax: +81-3-32248992. Dynamit Nobel AG, Sparte Chemikalien, D-5210 Troisdorf, Germany; tel: +4922-41-850; fax: 49-22-41-8527-93 Dyneon GmbH, Hammfelddamm 11, D-41460 Neuss, Germany; tel: + 4 9 - 2 1 3 1 14-2727; fax:+49-2131-14-3857 Dyneon LLC, 6744 33rd Street North, Oakdale, MN 55128, USA; tel: +1-612737-6700; fax: +1-612-737-7686 Dyno Industrier AS, PO Box 779, Sentrum N-0106 Oslo, Norway; tel: +47-2231-7000; fax:+47-22-3178-56. Gebr. Dorfner GmbH & Co, D-92242 Hirschau, Germany; tel: 49-9622-820; fax: +49-9622-8269 Georg Deifel KG, Mainberger StraBe 10, D-8720 Schweinfurth, Germany; tel:+49-9721-1774; fax:+49-9721-185-099
340
Additives for Plastics Handbook
E C H Erbsloh, Dusseldorfer StraEe 103, D-47809 Krefeld, Germany; tel: +492151-52500; fax:+49-2151-525-152 C H Erbsloh, KaistraBe 5 Postfach 29 26, D-2000 Hamburg 11, Germany; tel:+49-211-390-0161; fax:+49-211-390-0121 Eastman Chemical Co, 1540 Broadway, New York, NY 10036, USA; tel: + 1 212-782-5200; fax:+1-212-782-5212. Eastman Chemical Co, Polymer Additives and Specialty Monomers Business Unit, POBox 4 3 1 , Kingsport, TN 37662, USA; tel: +1-615-229-2000; fax: + 1-615-224-0648 Eastman Chemical, Europe, Middle East and Africa Ltd, Tobias Asserlaan 5, 2517 KC The Hague, The Netherlands; tel: +31-70-370-1722; fax: + 3 1 70-3 70-1702 ECC International pic, John Keay House, St. Austell PL25 4DJ, UK; tel: +441726-74482; fax:+44-1726-623019 ECC International SA, 2 rue du Canal, B-4551 Lioxhe, Belgium; tel: + 3 2 - 4 1 7998-ll;fax:+32-41-7982-79 ECC International, 100 Mansell Court East, Suite 300, Roswell, GA 30076, USA; tel: +1-770-594-0660; fax: +1-770-645-3384 ECC Japan Ltd, 10th Central Building, 10-3 Ginza 4-chome, Chuo-ku, Tokyo 104,Japan; tel:+81-3-3456-8250; fax:+81-3-3456-8255 Eckart-Werke GmbH, Kaiserstrage 30, D-90763 Furth, Germany; tel: + 4 9 - 9 1 1 99-78-0; fax:+49-911-78-238 Elan Corp; 174 Post Road West, Westport, CT 06880, USA; tel: +1-203-2227399; fax:+1-203-222-1819 Elastogran GmbH, Postfach 1140 D-49440 Lemforde, Germany; tel: + 4 9 - 5 4 4 3 12-0; fax: +49-5443-12-2100 Elementis pic. One Great Tower Street, London EC3R 5AH, UK; tel: + 4 4 - 1 7 1 711-1400 Elementis Specialties, 400 Claremont Avenue, Jersey City, NJ 07304, USA; tel: + 1-201-432-0800; fax: +1-201-432-0266 Elf Atochem Deutschland GmbH, TersteegenstraBe 28, D-40474 Dusseldorf, Germany; tel:+49-211-4552-304; fax:+49-211-4552-349 Elf Atochem North America, 2000 Market Street, Philadelphia, PA 19103, USA; tel:+1-215-419-7000; fax:+1-215-419-7413 Elf Atochem UK Ltd, Colthrop Way, Thatcham, Newbury RG13 4LW, UK; tel: +44-635-870000; fax: +44-635-870050. Elf Atochem, Cedex 42, 92091 Paris-La-Defense, France; tel: +33-1-49-008018; fax: +33-1-49-00-8050 Ellis & Everard Pic, 119 Guildford St, Chertsey, Surrey KT16 9AL, UK; tel: +441932-566033;fax:+44-1932-560363 EM Industries Inc, 5 Skyline Drive, Hawthorne, NY 10532, USA; tel: +1-914592-4660; fax: +1-914-592-9469 Emerson & Cuming, Composite Materials Inc, 77 Dragon Court, Woburn, MA 01888,USA;tel:+1-617-938-8630; fax:+1-617-933-4318
Appendix E: Directories
341
EMS-Chemie AG, 7013 Domat/Ems, Switzerland; tel: +41-81-36-7345; fax: +41-81-36-7454 Endex International, 111 Main Street, Box 381, Kingston, IL 60145, USA; tel:+1-815-784-2446; fax:+1-815-784-6012 Endex Polymer Additives Inc, 2198 Ogden Ave, Suite 131, Aurora, IL 60504, USA Engel Vertriebsgesellschaft mbH, A-4311 Schwertberg, Austria; tel: +43-7262620-0; fax: +43-7262-620-308 Engelhard Corp, 101 Wood Ave, Iselin, NJ 08830-0770, USA; tel: +1-908-2055 0 0 0 ; f a x + l - 9 0 8 321 0250 Engelhard Corp, Performance Minerals Group, 101 Wood Ave S. CN 770, Iselin, NJ 08830-0770, USA; tel:+1-908-205-5000; fax:+1-908-205-6711 EniChemPolimerisrl, ViaRossellini 15-17,1-20124, Italy; tel:+39-263-331 EPI (UK) Ltd, European HQ, Chatsworth Technology Park, Chesterfield S41 8XA, UK; tel: +44-1246-261882; fax: +44-1246-261883 EPI Environmetal Products Inc, 103 Longview Drive, Conroe, TX 77301, USA; tel: +1-409-788-2998; fax: +1-409-788-2968 Epolin Inc, 358-364 Adams St, Newark, NJ 07105, USA; tel: +1-201-465-9495; fax:+1-201-465-5353 Esseti Plast Sri, Via IV Novembre 98, 1-21058 Olona (Va), Italy; tel: + 3 9 - 3 3 1 641-159;fax:+39-331-375-182 Ethyl SA Chemicals Group, London Road, Bracknell RG12 2UW, UK; tel: +441344-780-378; fax:+44-1344-773-860 European Vinyls Corporation International SA/NV, Boulevard du Souverain 360, B-1160 Brussels, Belgium; tel: +32-2-674-0967; fax: +32-2-6601181 Europol pic, Fauld Industrial Estate, Tutbury, Burton-on-Trent, Staffs DEI 3 9HR, UK; tel:+44-1283-815-611; fax:+44-1283-813-139 Eurotherm Controls Ltd, Faraday Close, Durrington, West Sussex BNl 3 3PL, UK; tel: +44-1903-268500; fax: +44-1903-265982 EVAL Co of America, 1001 Warrenville Rd, Suite 2 0 1 , Lisle, IL 60532, USA; tel:+1-630-719-4615 EVC International SA/NV, Boulevard du Souverain 360, B-1160 Brussels, Belgium; tel: +32-2-674-0967; fax: +32-2-660-1181 Everlight Chemical industrial Corp, 6 Floor, Chung Ting Bldg, No 77 Sec 2 Tun Hua S Road, Taipei, RC; tel: +886-2-706-6006; fax: +886-2-708 1254 Evode Plastics Ltd, Wanlip Road, Syston, Leicester LE7 8PD, UK; tel: +44-1533696-752; fax:+44-1533-692-960 Exatec GmbH & Co KG, Friedrich-Ebert-StraBe, D-51429 Bergisch Gladbach, Germany; tel:+49-2204-84-2700; fax:+49-2204-84-2705 Exatec LLC, 31220 Oak Creek Drive, Wixom, MI 4 8 3 9 3 , USA Expancel, Box 13000, 850-13 Sundsvall, Sweden; tel: +46-60-1340-00; fax: +46-60-5695-18 Exxon Chemical Europe Inc, Mechelsteenweg 363, B-1950 Kraainem, Belgium; + 32-2-769-3562; fax:+32-2-769-3446
342
Additives for Plastics Handbook
Exxon Chemical Europe Inc, Vorstlaan 280, Bid du Souverain, B-1160 Brussels, Belgium; tel:+32-2-674-4111; fax:+32-2-674-4129 Exxon Chemical Europe, Mechelesteenweg 363, B-1950 Kraainem, Belgium; tel:+32-2-769-3111; fax:+32-2-769-3225 Exxon Chemical Ltd, PO Box 122, 4600 Parkway, Fareham, Hampshire P 0 1 5 7AP, UK; tel: +44-489-884406; fax: +44-489-884477 Exxon Corp, PO Box 140369, Irving, TX 75014-0369, USA; tel: +1-972-4441000
F Faerch Plast A/S, PO Box 10 40, DK-7500 Holstebro, Denmark; tel: +45-97425122; fax:+45-97-401476 Fagerdala World Foams AB, S-13900 Vaermdoe, Sweden; tel: +46-766-45200; fax:+46-766-45940 Fahr Bucher GmbH, GewerbestraGe 3 1 , D-78240 Gottmadingen, Postfach 1164, Germany; tel: +49-7731-904-0; fax: +49-7731-904-151 Fairmount Chemical Co Inc, 117 Blanchard Street, Newark, NJ 0 7 1 0 5 , USA; tel:+1-201-344-5790; fax:+1-201-690-5298 Fanuc Ltd, Oshinomura, Minami-Tsurugun, Yamanashi Prefecture 401-05, Japan; tel:+81-555-84-5555; fax:+81-555-84-5512; tx: 3385402 Farrell Corporation, 25 Main Street, Ansonia, CT 0 6 4 0 1 , USA; tel: +1-203-7365500 Faxe Kalk, Frederiksholms Kanal 16, PO Box 2183, DK-1017, Copenhagen K, Denmark; tel:+45-33-13-7500; fax:+45-33-12-7874 FCM Parco Sri, Via Sansovino 243/50, 10151 Turin, Italy; tel: +39-11-9840814;fax:+39-11-984-0114. Ferro Chemicals Group, 1000 Lakeside Ave, Cleveland, OH 44114, USA; tel: + 1 216-641-8580 Ferro Corp, World Headquarters, 1000 Lakeside Avenue, Cleveland, OH 441141183, USA; tel:+1-216-641-8580; fax:+1-216-696-6958 Ferro Plastic Europe, v. Helmenstraat 20, NL-3029 AB Rotterdam; tel: +31-10478-4911; fax:+31-10-477-8202 Ferrofluidics Ltd, Talisman Business Centre, Bicester, Oxford 0X6 OJX, UK; tel: +44-1869-363200; fax: +44-1869-363201 Fibrolux GmbH, Oberlindau 23, D-6000 Frankfurt/Main, Germany; tel: +49-6972-8903; fax: +49-69-724-1212 Filtec Ltd, Constance House, Waterloo Road, Widnes, Cheshire WAS OQR, UK; tel:+44-151-495-1988; fax:+44-151-1407 Fina Chemicals, Rue de Tlndustrie 52, B-1040 Brussels, Belgium; tel: +32-2288-3143; fax: +32-2-288-3322 Karl Finke GmbH & Co KG, Hatzfelder StraBe 174-176, D-42281 Wuppertal, Germany; tel: +49-202-70-9060; fax: +49-202-70-3929 FMC Corporation, Chemical Products Group, 1735 Market Street, Philadelphia, PA 19103, USA; tel:+1-215-299-6000; fax:+1-215-299-5999
Appendix E: Directories
343
Foboha GmbH, SchwarzwaldstraSe 4, D-7612 Haslach, Germany; tel: +497832-7980; fax: +49-7832-798-88 Formold Ltd, Ruscombe Park, Ruscombe Lane, Twyford RGIO 9JZ, UK; tel: +44734-340443; fax: +44-734-342160. Forsheda Polymer Engineering Group, Lambourn Court, Abingdon 0X14 lUH, UK; tel:+44-1235-555570; fax:+44-1235-536359 Forward Ultrasonics, l i e Cosgrove Way, Luton LUl IXL, UK; tel: +44-582429335; fax: +44-582-456359. Foster Wheeler Corp, Perryville Corporate Park, Clinton, NJ 08809-4000, USA; tel: +1-908-730-5262; fax: +1-908-730-5315 Foster Wheeler Ltd, Foster Wheeler House, Station Road, Reading, Berkshire RGl ILX, UK; teL +44-734-585211; fax: +44-734-396333. Franklin Industrial Minerals, 612 Tenth Avenue North, Nashville, TN 3 7203, USA; tel:+1-615-259-4222; fax:+1-615-726-2693 Frekote Inc, 164 Folly Mill Road, Seabrook, NH 03874, USA; tel: +1-603-4745541 Frekote Mold Release Products, Dexter Corp, One Dexter Drive, Seabrook, NH 03874-4018, USA; tel:+1-603-474-5541; fax:+1-603-474-5545 Freudenberg Carl, Postfach 180, D-6940 Weinheim, Germany; tel: + 4 9 - 6 2 0 1 801; fax: 49-6201-69300 Frisetta GmbH, Postfach 49, D-7869 Schonau/Schwarzwald, Germany; tel:+49-76-73-10014 Fuji Heavy Industries Ltd, 1-7-2, Nishi-Shinjuku, Shinjuku-ku, Tokyo 160, Japan; tel: +81-3-3347-2024; fax: +81-3-3347-2338
G
Gabriel Chemie GmbH, Industriestrafie 1, A-2352 Gumpoldskirchen, Austria; tel:+43-2252-636-300; fax:+43-2252-636-60 Gabriel-Chemie UK Ltd, Transfesa Road, Paddock Wood TNI2 6UT, UK; tel: +44892-836566; fax: +44-892-836979. Gas Injection Ltd, Kiltearn House, Hospital Street, Nantwich CW5 5RL, UK; tel: +44-270-625678; fax: +44-270-626646. Gaypa Sri, Via Tribollo 6/8, Minticello Conte Otto (Vi), Italy; tel: +39-444-946088; fax: 39-444-946-027 GE Speciality Chemicals, General Electric Plastics BV, Plasticslaan 1, PO Box 117, NL-4600 AC Bergen op Zoom, The Netherlands; tel: +31-164032911;fax:+31-1640-32940 GE Specialty Chemicals, PO Box 1868, 501 Avery Street, Parkersburg, WV 26102-1868, USA; tel: +1-304-424-5411; fax: +1-304-424-5871 GenCorp Polymer Products, 165 S. Cleveland Avenue, Mogadore, OH 44260, USA; tel:+1-216-628-6542; fax:+1-201-515-2468 The Geon Company, One Geon Center, Avon Lake, OH 44012, USA; tel: +1-440930-1000 George Fischer (Great Britain) Ltd, Paradise Way, Walsgrave Triangle, Hinckley Road, Coventry CV2 2SP, UK; tel: +44-203-535535; fax: +44-203-530450
344
Additives for Plastics Handbook
Georgia Marble Co, 1201 Roberts Blvd, Bldg 100, Kennesaw, GA 30144-3619, USA; tel:+1-404-421-6500; fax:+1-404-421-6507 Gevetex Texilglas GmbH, Postfach 1160, D-5120 Herogenrath, Germany; tel: +49-2406-810; fax: +49-2406-792-86 GF Axxicon BV, PO Box 3229, NL-5902 RE Venlo, The Netherlands; tel: +31-77820055; fax: +31-77-824465. GFI (UK) Ltd, Marie Place, Brenchley, Tonbridge, UK; tel: +44-1892-724-534 fax:+44-1892-724-4099 Gharda Chemicals Ltd, 48 Hill Road, Bandra (W), Bombay 400 050, India tel: +91-22-642-6852; fax: +91-22-640-4224 Gildemeister (UK) Ltd, Unitool House, Camford Way, Sundon Park, Luton, UK tel:+44-582-570661; fax:+44-582-593700. GlassTech Scandinavia AB, Box 1013, Angelholm 262-21, Sweden; tel: +46431-250-75; fax: +46-431-250-76 Goldmann GmbH & Co KG, Postfach 3405, Bielefeld 1, Germany; tel: +49-5213-5046; fax: +49-5-213-224-52 Th. Goldschmidt AG, Postfach 10 14 6 1 , D-45116 Essen, Germany; tel: +49201-173-2365; fax:+49-201-173-1838 Goldschmidt Chemical Corp, 11 West 17th Street, Suite G3, Costa Mesa, CA 92627, USA; tel: +1-714-650-2161; fax: +1-714-642-9478 Goldschmidt Industrial Chemical Corp, Pitt Metals and Chemicals Divn, 941 Robinson Highway, PO Box 2 79, McDonald, PA 15057-02 79, USA; tel:+l-412-796-1511;fax:+1-412-922-6657 B F Goodrich Chemical, Goerhtzer StralSe 1, D-4040 Neuss, Germany; tel: +4921-01-180-50; fax:+49-21-01-1800 B F Goodrich Specialty Chemicals, 9911 Brecksville Road, Cleveland, OH 4 4 1 4 1 3247, USA; tel:+1-216-447-5000; fax:+1-216-447-5750 Goodyear Chemical, Av des Tropiques, ZA Courtaboef 2, F-91955 Les Ulis Cedex, France; tel: 33-216-796-8295 Goodyear Tire & Rubber Co, Akron, OH 44316, USA; tel: +1-216-796-8295; fax:+1-216-796-3199 Great Lakes Chemical (Deutschland) GmbH, Overather Strafie 50-52, D-51429 Bergisch Gladbach, Germany; tel: +49-2204-954-30; fax: +49-2204-56862 Great Lakes Chemical (Europe) GmbH, JuchstraSe 45, CH-8500 Frauenfeld, Switzerland; tel: +41-52-723-4400; fax: +41-52-723-4499 Great Lakes Chemical (Europe) Ltd, PO Box 44, Oil Sites Road, Ellesmere Port, L65 4GD, UK; tel: +44-151-356-8489; fax: +44-151-356-8490 Great Lakes Chemical Corp, PO Box 2200, West Lafayette, IN 47906, USA; tel:+1-317-497-6100 GretagMacbeth Ltd, Pacific Road, Altrincham WA14 5BJ, UK; tel: +44-161926-9822; fax: +44-161-926-9835 Grinit Plast Sri, 22076 Mozzate (Co), Strada Statale 223, 1126, Italy; tel: +39331-831-625;fax:+39-331-833-731 Gulf Lubricants, Rosehill, New Barn Lane, Cheltenham GL52 3LA, UK; tel: +441242-225588;fax:+44-1242-225507
Appendix E: Directories
345
Gusmer Machinery Group Inc, One Gusmer Drive, PO Box 2055, Lakewood, NJ 08701-8055, USA; tel: +1-908-370-9000; fax: +1-908-905-8968 Gusmer-Admiral Inc, 305 West North Street, Akron, OH 4 4 3 0 3 , USA; tel: + 1 330-253-1353; fax:+1-330-253-7715
H G E Habich's Sohne, Postfach 67, D-3512 Reinhardshagen, Germany; tel: +4955-44-1071; fax:+49-55-44-79172 Hager & Kassner GmbH, Postfach 4 49, D-4730 Ahlen 1, Germany; tel: +49-2140-9074; fax:+49-23-82-5151 Hampton Colours Ltd, Toadsmoor Mills, Brimscombe, Stroud GL5 2UH, UK; tel: +44-1453-731-555; fax: +44-1453-731-234 Handy & Harman Automotive Group Inc, Auburn Hills, MI, USA; tel: +1-810377-0700; fax:+1-810-377-2085 Hanna Company - Wilson Color, 161 Dreve de Richelle, 1410 Waterloo, Belgium; tel: +32-2-352-0550; fax: +32-2-353-0566 M A Hanna Company, Suite 36-5000, 200 Public Square, Cleveland, OH 441142304, USA; tel: +1-216-589-4000; fax: +1-216-589-4200 Hanse Chemie GmbH, Charlottenburger StraSe 9, D-21502 Geesthacht, Germany; tel: +49-41-5280-920; fax: +49-41-5279-156 Harcros Chemicals UK Ltd, Lankro House, Silk St PO Box 1, Eccles, Manchester M300BH,UK;tel:+44-161-789-7300; fax:+44-161-787-8313 Hartmann Drukfarben GmbH, Postfach 60 03 49, D-6000 Franfurt/Main, Germany; tel: +49-69-4000-1; fax: +49-69-4000-286 W Hawley & Son Ltd, Colour Works, Duffield, Belper DE56 4FG, UK; tel: +441332-840-294; fax:+44-1332-842-570 Henkel Corp, 11501 Northlake Drive, Cincinnati, OH 45249, USA; tel: +1-513530-7415; fax:+1-513-530-7581 Henkel KGaA, Plastics Technology, D-40191 Dusseldorf, Germany; tel: +49211-7970; fax:+49-211-798-9638 Heraeus Equipment Ltd, Unit 9, Wates Way, Brentwood, Essex CM15 9TB, UK; tel:+44-277-231511;fax:+44-277-261856. Herberts GmbH, Christbusch 25 Postfach 2002 44, D-5600 Wuppertal 2, Germany; tel: +49-202-8941; fax: +49-202-8995-73 Herberts Polymer Powders SA, PO Box 140, CH-1630 Bulle, Switzerland; tel:+41-26-913-5111; fax:+41-26-912-7989 Herbold Granulators UK Ltd, 6 Dewar Court, Astmoor, Runcorn WA7 IPT, UK; tel: +44-928-581309; fax: +44-928-581306 Hettinga Equipment Inc, 2123 North West 111th Street, Des Moines, lA 503253 788, USA; tel:+1-515-270-6900; fax:+1-515-2 70-1333 High Polymer Laboratories, Vishal Bhawan, 95 Nehru Place, New Delhi 110 019, India; tel:+91-11-643-1522; fax:+91-11-647-4350 Hitox Corp. of America, PO Box 2544, Corpus Christi, TX 78403, USA; tel: + 1 512-882-5175; fax:+1-512-882-6948
346
Additives for Plastics Handbook
Hoechst AG, Business Unit Additive, Gersthofen Postfach 10 15 67, D-86005 Augsburg 1, Germany; tel: +49-821-4790; fax: +49-821-479-2890 Hoffmann Mineral, Postfach 14 60, D-86619 Neuburg (Donau), Germany; tel: +49-84-31-530; fax: +49-84-31-53-330 Holland Colors America Inc, 1501 Progress Drive, Richmond, IN 47374, USA; tel:+1-317-935-0329; fax:+1-317-966-3376 Holland Colours Apeldoorn BV, Halvemaanweg 1 Postbus 720, 7300 AS Apeldoorn,TheNetherlands; tel:+31-55-366-3143; fax:+31-55-366-2981 Holliday Chemical Holdings pic, Brikby Grange, 85 Birkby Hall Rd, Huddersfield HD2 2XB, UK; tel: +44-1484-828-200; fax: +44-1484-828-230 Holliday Pigments Ltd, Morley Street, Kingston-upon-Hull HU8 8DN, UK; tel:+44-1482-329-875; fax:+44-1482-223-114 Holometrix Inc, 25 Wiggins Avenue, Bedford, MA 01730-2323, USA; tel: + 1 617-275-3300; fax;+1-617-275-3 705 J M Huber Corp, Solem Division, 4940 Peachtree Industrial Blvd, Suite 340 Norcross, GA 30071, USA; tel: +1-770-441-1301; fax: +1-770-368-9908 Hubron Manufacturing Divn Ltd, Albion Street, Failsworth, Manchester M35 OFP, UK; tel:+44-161-681-2691; fax:+44-161-683-4658 Hiils AG, Paul-Bauman-Str 1 Postf 1320, D-45 764 Marl, Germany; tel: +49-236549-1; fax:+49-23-49-4179 Hiils America Inc, 80 Centennial Ave, PO Box 456, Piscataway, NJ 0 8 8 5 5 0456, USA; tel: +1-908-980-6800; fax: +1-908-981-5497 Huntingdon Fusion Techniques Ltd, Stukeley Meadows, Huntingdon PE18 6EJ, UK; tel: +44-480-412432; fax: + 4 4 - 4 8 0 - 4 1 2 8 4 1 . Huntsman Corporation, 500 Huntsman Way, Salt Lake City, UT 84108, USA; tel: +1-801-584-5700; fax: +1-801-584-5791 I ICI Chlor-Chemicals, PO Box 14, The Heath, Runcorn WA7 40G, UK; tel: +441928-513846;fax:+44-1928-569459 Image Automation Ltd, Kelvin House, Worsley Bridge Road, London SE26 5BX, UK; tel:+44-181-461-5566. Inbra Industrias Quimicas Ltda, Av Fagundes de Oliveira 190, Piraporinha Diadema, SP 09950-907, Brazil; teh +55-11-745-4133; fax: +55-11-7462011 Incemin AG, Schachen 82, CH-5113 Holderbank, Switzerland; tel: +41-62-532627;fax:+41-62-893-2017 Incoe Corp, 2111 Stephenson Highway, PO Box 485, Troy, MI 4 8 0 8 3 , USA; tel:+1-313-689-0220; fax:+1-313-689-3278. Indspec Chemical Corp, 411 Seventh Avenue, Suite 300, Pittsburgh, PA 15210, USA; tel: +1-412-765-0439; fax: +1-412-765-1200 Inducolor SA, De Bavaylei 66, B-1800 Vilvoorde, Belgium; tel: +32-2-2512604; fax:+32-2-252-4567 Industrie Generah SpA, Via Milano 2 0 1 , PO Box 28, 1-21017 Samarate (Va), Italy; tel: +39-331-220-537; fax: +39-331-222-492
Appendix E: Directories
347
Instron Ltd, Coronation Road, High Wycombe HP12 3SY, UK; tel: +44-1494464646; fax: +44-1494-456124 IRG Plastics Ltd, Old Wolverton Road, Milton Keynes MK12 5PS, UK; tel: +441908-225600; fax: +44-1908-222607 Ishikawajima-Harima Heavy Industries Co Ltd, 2-2-1, Ohtemachi, Chiyoda-ku, Tokyo 100, Japan; tel: +81-3-3244-5111; fax: +81-3-3244-5131; tx: 22232. Italmaster Sri, Via Somma 72, 1-20012 Cuggiono (Milano), Italy; tel: +39-29724-1328; fax:+39-2-9724-1333 Itoh, C & Co Ltd, 4-1-13, Kyutaromachi, Chuo-ku, Osaka 541, Japan; tel: +81-6241-2121; fax:+81-6-241-3167; tx: 63260.
I Jackdaw Polymers Ltd, Stockton Street, Littleborough 0L15 8YJ, UK; tel: +441706-377115;fax:+44-1706-37793 Jayant Oil Mills, 13 Sitafalwadi, Dr Mascarenhas Road, Mazgaon, Bombay 400 010, India; tel:+91-22-373-8810; fax:+91-22-373-8107 Jayell Plastics (Mktg) Ltd, 4 Hawthornden Manor, Bramshall Road, Uttoxeter ST14 7PH, UK; tel: +44-1889-566-647; fax: +44-1889-566-648 Johnson Controls, Manchester, MI, USA; tel: +1-313-428-8371; fax: +1-313428-9237. Johnson Matthey Electronics, East 15128 EucHd Avenue, Spokene, WA 99216, USA; tel: +1-509-924-2200 Johnson Matthey pic, Precious Metals Division, Orchard Road, Royston SG8 5HE,UK;tel:+44-1763-253-385;fax:+44-1763-253-419 Jotun Polymer A/S, PO Box 2 0 6 1 , Sandefjord N-3201, Norway; tel: +47-334570-00; fax: +47-334-64614 JPSElastomerics,c/oB.LeMonte,Polymar, Belgium; fax+32-3 650 1690 K Kabi Pharmacia AB, 75182 Uppsala, Sweden; tel: +46-1816-3006; fax: +461869-2864 Kali-Chemie AG, Hans-Bockler-Allee 20, Postfach 220 D-3000 Hannover 1, Germany;tel:+49-511-8571; fax:+49-511-282-126 Kalle Pentaplast GmbH, PO Box 11 65, D-56401, Montabaur, Germany; teL+49-2602-915-130; fax:+49-2602-915-179 Kaneka Belgium NV, Nijverheidsstraat 16, B-2260 Westerlo-Oevel, Belgium; tel:+32-1421-494; fax:+32-1321-6223 Kaneka Corp, 3-12, 1-Chome, Motoakasaka, Minato-ku, Tokyo, Japan; tel: + 8 1 3-3479-9647; fax: +81-3-3479-9699 Kaneka Texas Corp, 17 South Briar Hollow, Houston, TX 77027, USA; tel: + 1 713-840-1751; fax:+1-713-552-0133 Karle Finke Farbstoffe, Hatzfelder StraSe 174-176, D-56000 Wuppertal 2, Germany; tel: +49-202-7040-51
348
Additives for Plastics Handbook
Kautschuk Gesellschaft mbH, Reuterweg 14, D-6000 Frankfurt, Germany; tel: +49-69-1590; fax: +49-69-1592-125 Kawasaki Steel Corp, 2-2-3, Uchi-Saiwaicho, Chiyoda-ku, Tokyo 100, Japan; tel:+81-3-3597-3111;fax:+81-3-3597-4868 KD Thermoplastics, 119 Guildford Street, Chertsey KT16 9AL, UK; tel: +441932-566033;fax:+44-1932-560363 Kemira Pigments Oy, Speciality Products, FIN-28840 Pori, Finland; tel: +35839-341-000; fax: +358-39-341-919 Kemira Pigments SA, Ave Einstein 11, B-1300 Wavre, Belgium; tel: +32-10232-711;fax:+32-10-229-892 Kemira Polymers, Station Road, Birch Vale, Cheshire SK12 5BR, UK; tel: +441663-746518; fax: +44-1663-746605 Kemutec Group Ltd, Hulley Road, Macclesfield SKIO 2ND, UK; tel: +44-1625428733; fax:+44-1625-427319 Kenrich Petrochemicals Inc, 140 East 22nd Street, PO Box 32, Bayonne, NJ 07002-0032, USA; tel: +1-201-823-9000; fax: +1-201-823-0691 Kerry Ultrasonics Ltd, Hunting Gate, Wilbury Way, Hitchin SG4 OTQ, UK; tel: +44-1462-450761; fax: +44-1462-420712 Kistler Instrument Corp, Amherst, NY 14228-2171, USA; tel: +1-716-6915100; fax:+1-716-691-5226. Kistler Instrumente AG, CH-8408 Winterthur, Switzerland; tel: +41-52831111; fax:+41-52-257200 KMG Minerals, Divn of Franklin Industrial Minerals, 1469 South Battleground Avenue, Kings Mountain, NC 28086, USA; tel: +1-704-739-3616; fax:+1-704-739-7888 Korlin Concentrates, 501 Eric Street, Stratford, Ontario N5A 2N7, Canada; tel:+1-519-271-1680 Krahn Chemie GmbH, Grimm 10, D-2000 Hamburg 11, Germany; tel: +49-403292-0; fax: +49-40-3292-322 Krauss-Maffei AG, Krauss-Maffei-Strafie 2, D-80997 Miinchen, Germany; tel: +49-89-8899-3551; fax: +49-89-8899-2230 Kronos International Inc, Peschstrafie 5, D-513 73 Leverkusen, Germany; tel:+49-214-3560; fax:+49-214-421-50 Kronos Ltd, Barons Court, Manchester Road, Wilmslow SK9 IBQ, UK; tel: +441625-547-200; fax:+44-1625-533-123 K-Tron Great Britain Ltd, 4 Southlink Business Park, Oldham, Lancashire 0L4 IDE, UK; tel: +44-161-626-4580; fax: +44-161-624-2853 Kuraray Co Ltd, Synthetic Rubber and Resin Dept, Maruzen Bldg 3-10, 2-chome, Nihonbashi, Tokyo 103, Japan; tel: +81-3-3277-6654; fax: +81-3-32776666 Kureha Chemical Industry Co Ltd, 1-9-11 Nihonbashi-Horidomecho, Chuo-ku, Tokyo 103-8552, Japan; tel: +81-3-3249-4666; fax: +81-3-3249-4601 Kvaerner A/S, PO Box 100, Skoyen N-0212 Oslo, Norway; tel: +47-22-967000; fax:+47-22-520122 Kyowa Chemical Industry Co. Ltd, 305 Yashima-Nishimachi, Takamatsu-shi, Karawa761-01,Japan; tel:+81-877-47-2500; fax:+81-877-47-4208
Appendix E; Directories
349
L Lab Craft, Church Road, Harold Wood, Romford RM3 OHT, UK; tel: +44-708349320; fax: +44-708-376394. Lanstar Ltd, Liverpool Road, Cadishead, Manchester M30 5DT, UK; tel: +44-61775-2644; fax: +44-61-776-1077 Laporte Worldwide Compounding Group, 170 Pioneer Drive, Leominster, MA 01453, USA; teL +1-978-537-8071 Laporte-AlphaGary Ltd, Wanlip Road, System, Leicester LE7 IPA, UK; tel: +44116-269-6752; fax:+44-116-269-2960 Lapp Insulator Co, 6 Apollo Drive, Batavia, NY 14020, USA; tel: +1-716-3441284; fax:+1-716-344-3872. Latha Chemical Co, 7 Kumarappa Maistry St, Madras 600 0 0 1 , India; tel: + 9 1 518-653 Lati Industria Thermoplastica, Via Baracca 7, 1-21040 Vedano Olona, Italy; tel:+39-332-409-111 Laurel Industries Inc, 30195 Chagrin Blvd, Cleveland, OH 44124-5794, USA; tel:+l-216-831-5747;fax:+1-216-831-8479 Lehmann & Voss & Co, Alsterufer 19, D-2000 Hamburg 36, Germany; tel: +4940-44197-1; fax: +49-40-441-97219 Llewellyn Ryland Ltd, Haden Street, Birmingham B12 9DB, UK; tel: +44-121440-2284; fax:+44-121-440-0281 Lloyd Instruments Ltd, 12 Barnes Wallis Rd, Fareham P015 5SH, UK; tel: +441489-574221; fax:+44-1489-885118 LNP Engineering Plastics Europe BV, Ottergeerde 22-30, NL-4941 VM Raamsdonksveer, The Netherlands; tel: +31-1621-87600; fax: + 3 1 1631-87730 Lodige Maschinenbau GmbH, Postfach 2050, D-33050 Paderborn, Germany; tel: +49-5231-3090; fax: +49-5231-309-123 Lohmann GmbH & Co KG, Irlicher StraSe 55, Postfach 1201 10, D-5450 Neuwied 12, Germany; tel: +49-2631-7860; fax: +49-2631-786467 Lonza AG, Postfach, 5643, Sins, Switzerland; tel: +41-42-660-111; fax: + 4 1 42-662-316 Lonza Inc, 17-17 Route 208, Fair Lawn, NJ 07410, USA; tel: +1-201-7942400; fax:+1-201-794-2515 Lonza SpA, Via Vittor Pisani 31,1-20124 Milan, Italy; teL +39-2-669-991; fax: + 39-2-669-876-30 Lonza-Werke GmbH, Postfach 1580, D-7858 Weil amRhein, Germany; tel: +497621-7030; fax:+49-7621-703-255 Lucky Ltd, Twin Towers Bldg 20 Yoido-Dong, Yongdeung Po-ku, PO Box 672, Seoul, S. Korea; taL +82-2 789 7407; fax: +82-2-787-7766 Luperox GmbH, Denzinger Strafie 7, Postfach 1354 D-8870 Gunzburg/Do, Germany; teL 49-8221-980; fax:+49-8221-98166 Luzenac, 131 Ave Charles de Gaulle, F-92200 Neuilly, France; teL +33-1-47459040; fax: +33-1-4747-5805 Lyondell Chemical Europe Inc, Bridge House, Maidenhead SL6 lYB, UK; tel: +44-1628-77500; fax: +44-1628-775180
350
Additives for Plastics Handbook
M Macbeth Divn. of Kollmorgen Instruments Corp., New Windsor, NY, USA; tel:+1-914-565-7660 Magnesia GmbH, PO Box 2168, D-21311 Luneburg, Germany; tel: + 4 9 - 4 1 3 1 52011;fax:+49-4131-53050 Mallinckrodt Specialty Chemicals, 16305 Swingley Ridge Drive, Chesterfield, MO 63017, USA; tel: +1-314-895-2000; fax: +1-314-530-2562 Mannesmann Demag Kunststofftechnik, Altdorfer StraSe 15, D-905 71 Schwaig, Germany; Tel:+49-911-50-61-232; Fax:+49-911-50-09-653. Marcel Dekker Inc, 2 70 Madison Avenue, New York, NY 10016, USA; tel: + 1 212-696-9000. Marine Magnesium Co, 995 Beaver Grade Road, Coraopolis, PA 15108, USA; tel: +1-412-264-0200; fax: +1-412-264-9020 Marion Merrell Dow Inc, 9300 Ward Parkway, PO Box 8480, Kansas City, MO 64114-0480, USA; tel: +1-816-966-4000; fax: +1-816-966-3802 R J Marshall Co, 26776 W Twelve Mile Road, Southfield, MI 48034-7807, USA; tel:+1-313-353-4100; fax:+1-313-948-6460 Martin Marietta Energy Systems Inc, PO Box 2008, Oak Ridge, TN 37831-6266, USA; tel:+1-615-574-4160. Martin Marietta Magnesia Specialties Inc, PO Box 15470, Baltimore, MD 212200470, USA; tel: +1-510-780-5500 Mason Chemical Co, Carolyn House, Dingwall Rd, Croydon CRO 9XF, UK; tel:+44-181-686-5625;fax:+44-181-686-1408 Mastio & Co, 802 Francis Street, St. Joseph, MO 6 4 5 0 1 , USA; tel: +1-816-3646200; fax: +1-816-364-3606. Mayzo Inc, 6577 Peachtree Industrial Blvd, Norcross, GA 30092, USA; tel: + 1 770-449-9066; fax: +1-770-449-9070 Mearl Corp, PO Box 3030, 320 Old Briarcliff Road, Briarcliff Manor, NY 10510, USA; tel: +1-914-923-9500; fax: +1-914-923-9594 Mearl Corporation, 41 East 42nd Street, New York, NY 10017, USA; tel: + 1 212-573-8500; fax:+1-212-557-0742 Mearl International BV, Emrikweg 18, 2031 BT Haarlem, The Netherlands; tel:+31-23-318-058;fax:+31-23-351-365 Megret Ltd, Woodlands, Ashcroft Road, Knowsley Industrial Park, Merseyside L33 7TW, UK; tel:+44-151-548-6800; fax:+44-151-547-5700 Meiki Co Ltd, 2, Ohne, Kitazaki-cho, Ohbu City, Aichi Prefecture 474, Japan; tel:+81-562-48-2111;fax:+81-562-47-2316 Mercator Inc, 560 Sylvan Avenue, Englewood Cliffs, NJ 07632, USA; tel: + 1 201-569-3533; fax:+1-201-569-7368 Merck E, Sparte Pigmente und Kosmetik, Frankfurter StraKe 250, D-64293 Darmstadt 1, Germany; tel: +49-6151-72-6309; fax: +49-6151-72 7684 Mergon International Ltd, 1 0 9 - 1 1 1 Ballards Lane, Finchley, London N3 IXY, UK; tel: +44-81-346-0744; fax: +44-81-346-2699. Merit (Malta) Ltd, PO Box 117, Valletta, Malta; tel: +356-484-184; fax: +356446-679
Appendix E: Directories
351
Merritt Davis Corp, 15 Marne Street, Hamden,CT 06514, USA; tel:+1-203-2308100; fax: +1-203-230-8989 Metalgesellschaft AG, Postfach 10 15 0 1 , Reuterweg 14, Frankfurt am Main 1, Germany; tel:+49-69-1590; fax:+49-69-159-2125 Mettler Toledo Ltd, 64 Boston Road, Leicester LE4 lAW, UK; tel: +44-116-2357070; fax:+44-116-236-6399 MGI-Coutier, 27 rue de Lisbon, Paris 75008, France; tel: +33-1-4289-3122; fax:+33-1-4562-8985. Microban International, 1221 Avenue of the Americas, 24th Floor, New York, NY 10020, USA; tel: +1-212-332-8730; fax: +1-212-332-8739 Micromet Instruments Inc, 7 Wells Avenue, Newton Centre, MA 02159, USA; tel:+1-617-969-5060; fax:+1-617-959-5040 Micropol Ltd, Bayley Street, Stalybridge, Cheshire SK15 IQQ, UK; tel: +44-161330-5570; fax:+44-161-330-7687 MilesIncMobayRoad, Pittsburgh, PA 15205-9741, USA; tel:+1-412-777-2000 Millennium Inorganic Chemicals Inc, 200 International Circle, Suite 5000, Hunt Valley, MD 21030, USA; tel: +1-410-229-4400; fax: +1-410-2294488 Milliken Chemical Divn, Milliken & Co, M-400 PO Box 192 7, Spartanburg, SC 29304-1927, USA; tel: +1-864-503-2200; fax: +1-864-503-2430 Milliken Chemical, Ham 18-24, B-9000 Gent, Belgium; tel: +32-9-265-1084; fax:+32-9-265-1195 Millinckrodt Specialty Chemicals Europe, Postfach 1268, Industriestrafie 19-21, D 6110 Dieburg, Germany; tel: +49-6071-200-40; fax: +49-6071-200-444 MIR UK Ltd, Unit 2, 15 Headley Road, Woodley, Reading RG5 5JB, UK; tel: +44734-441037; fax: +44-734-441045. MIRC Europe SA, 54 rue Vandenhoven, B-1150 Brussels, Belgium; tel: +32-2762-2781; fax:+32-2-771-7248 MIRC USA, 2525 Charleston Road, Mountain View, CA 9 4 0 4 3 , USA; tel: + 1 415-961-9000; fax:+1-415-961-5042 MIRC/NSI Japan, Schon Lebrn Yoshida Building, 3-9-15, Nishi-Gotanda, Shinagawa- ku, Tokyo 141, Japan; tel: +81-3-5434-2730; fax: +81-35434-2733. Mitsubishi Chemical Co Ltd, 2-5-2, Marunouchi, Chiyoda-ku, Tokyo 100, Japan; tel:+81-3-3283-6111;fax:+81-3-3287-0833 Mitsubishi Kasei Corp, 2-5-2, Marunouchi, Chiyoda-ku, Tokyo 100, Japan; tel:+81-3-3283-6254; fax:+81-3-3283-6787 Mitsubishi Petrochemical Co Ltd, 2-5-2, Marunouchi, Chiyoda-ku, Tokyo 100, Japan; tel: +81-3-3283-5700; fax: +81-3-3283-5805 Mitsubishi Rayon Co Ltd, 2-3-19 Kyobashi, Chuo-ku, Tokyo 104-0031, Japan; tel: +81-3-3245-8765; fax: +81-3-3245-8782 Mitsui & Co Deutschland GmbH, Konigsallee 63-65, D-40215 Diisseldorf, Germany;tel:+49-211-9386-347; fax:+49-211-9386-348 Mitsui Petrochemical Industries Co Ltd, Kasumigaseki Building, 3-2-5, Kasumigaseki, Chiyoda-ku, Tokyo 100, Japan; tel: +81-3-3580-3616; fax: +81-3-3593-0028.
352
Additives for Plastics Handbook
Mitsui Toatsu Chemicals Inc, 3-2-5, Kasumigaseki, Chiyoda-ku, Tokyo 100, Japan; tel:+81-3-3592-4111; fax:+81-3-3592-4267 Moldflow Singapore, Orchard, PO Box 0745, Singapore 9123; tel: +65-7386760; fax:+65-738-2783. Moldflow (Europe) Ltd, Central Court, Knoll Rise, Orpington BR6 OJA, UK tel:+44-1689-878-111; fax:+44-1689-878-678 Monsanto Chemicals SA, Av de Tervuren 2 70-272, B-1150 Brussels, Belgium tel:+32-2-761-4111; fax:+32-2-761-4040 Monsanto Company, 800 N. Lindbergh Boulevard, St Louis, MO 63167, USA tel:+1-314-694-5274 Montedison SpA, Fuoro Buonaparte 31,1-20121 Milano, Italy; tel: +39-2-62 705519;fax:+39-206270-5268 Montell Polyolefins, Functional Chemicals, Three Little Falls Centre, 2801 CentervilleRoad,POBox 15439, Wilmington, DE 19850-5981, USA Montell Polyolefins, Woluwe Garden, Woluwedal 24, B-1932 Zaventem, Belgium; tel: +32-2-715-8164; fax: +32-2-715-8264 Morton International Inc, Morton Plastics Additives, 2000 West Street, Cincinnati, OH45215-3431, USA; tel:+1-513-733-2100; fax:+1-513-733-2133 Multibase Inc, 3835 Copley Road, Copley, OH 4 4 3 2 1 , USA; tel: +1-216-8675124;fax:+1-216-666-7419 Multibase SA, ZI du Guiers, F-38380 Saint-Laurent-du-Pont, France; tel: + 3 3 76-67-1212; fax: +33-76-67-1292 Murtfeldt GmbH & Co KG, Postfach 120161, D-4600 Dortmund 12, Germany; tel:+49-231-251-012; fax:+49-231-251-021
N NEC Corp, 5-7-1 Shiba, Minato-ku, Tokyo 108-8001, Japan; tel: +81-3-3454llll;fax:+81-3-3457-7249 Negri Bossi spa, Viale Europa 64, 20093 Cologno, Monzese, Milan, Italy; tel:+39-2-273-02545; fax:+39-2-253-8264. Nemitz Kunststoff-Additive GmbH, PO Box 122 7, D-48338 Altenberge, Germany; tel: +49-2505-674; fax: +49-2505-3042 Neocrin Co, 1202 East Neocrin Avenue, Santa Ana, CA 92 705, USA; tel: + 1 714-541-1606; fax: +1-714-541-5423. Neste Chemicals, PO Box 20, SF-02151 Espoo, Finland; tel: +358-0-450-5044; fax:+358-0-450-4985 Neste Oy, Corporate Head Office, Keilaniemi, PO Box 20, SF-02151 Espoo, Finland; tel:+358-0450-1; fax:+358-0450-4447 Neste Polymer Compounds AB, Sweden; tel: +46-8-709-6552; fax: +46-8-7096590. Neu Engineering Ltd, Planet House, Guildford Road, Woking GU22 7RL, UK; tel:+44-1483-756-565; fax:+44-1483-755-177 Nevicolor SpA, Via Maso 2 7, 1-42045 Luzzara (Regio Emilia), Italy; tel: +39522-9764-21; fax: +39-522-9765-69
Appendix E: Directories
353
Nihon Kakaku Sangyo Co Ltd, 20-5 Shitaya 2-chome, Taito-ku, Tokyo 110, Japan; tel:+81-3-3876-3131; fax:+81-3-3876-3278 Niigata Engineering, 1-4-1 Kasumigaseki, Chiyoda-ku, Tokyo 100, Japan; tel:+81-3-3504-2182; fax:+81-3-3595-2648 Nikkan Kogyo Shimbun Ltd, International Division Office, 5F, Kobu Building, 1-2-14, Shinkawa, Chuo-ku, Tokyo 104, Japan; tel: +81-3-5543-0144; fax:+81-3-5543-0212. Niplast Engineering, 187 Higher Hillgate, Stockport SKI 3JG, UK; tel: + 4 4 - 6 1 477-6777; fax: +44-61-429-8413. Nippon Paint Co Ltd, 2-1-2, Oyodokita, Kita-ku, Osaka 5 3 1 , Japan; tel: +81-6458-1111; fax:+81-6-455-9260 Nippon Shokubai Co Ltd, Kogin Building, 4-1-1, Koraibashi, Chuo-ku, Osaka 541,Japan; tel:+81-6-223-9111;fax:+81-6-201-3716 Nippon Steel Chemical Co Ltd, 5-13-16, Ginza, Chuo-ku, Tokyo 104, Japan; tel:+81-3-3542-1321; fax:+81-3-3546-3575 Nippon Steel Corp, 2-6-3, Ohtemachi, Chiyoda-ku, Tokyo 100-71, Japan; tel:+81-3-3242-4111;fax:+81-3-3275-5611 Nissei Plastic Industrial Co. Ltd, 2110 Minamijo, Sakaki-machi, Nagano 383-06 Japan; tel: +81-268-81-1070; fax: +81-268-81-1098 Nissin Electric Co Ltd, 47 Umezu-takase-cho, Ukyo-ku, Kyoto 615, Japan; teL+81-75-861-3151;fax:+81-75-872-0742 Nitto Chemical Industry, 1-5-1 Marunouchi, Chiyoda-ku, Tokyo 100, Japan; tel:+81-3-3271-0251; fax:+81-3-3287-2725 NOP Corporation, Yurakucho Bldg 2-8 Toranomon 1-chome, Chiyoda-ku, Tokyo 100, Japan; tel: +81-3-3283-7295; fax: +81-3-3283-7178 Normann Rassmann GmbH & Co, Kajen 2, D-2000 Hamburg 11, Germany; tel: +49040-368-70; fax: +49-40-368-7249 Norsk Hydro Petrochemicals Division, Bygdoy AUe 2, N-0240 Oslo 2, Norway Novalis Fibres, 129 rue Servient BP 3052, Lyon Cedex 03, France; tel: +33-786280-47 Nyco Minerals Inc, 124 Mountain View Drive, Willsboro, NY 12996-0368, USA; tel:+1-518-963-4262; fax:+1-518-963-4187 Nyco Minerals Inc, Europe, Ordrupvej 24, PO Box 88, DK-2920 Charlottenlund, Denmark; tel:+31-64-3370; fax:+31-64-3710
O Obron Atlantic Corporation, PO Box 747, Painsville, OH 44077, USA; tel:: + 1 216 3 5 4 0 4 0 0 ; fax:+1-216-354-6224 Occidental Chemical Corp, Occidental Tower, LBJ Freeway, Dallas, TX 75244, USA; tel: +1-214-404-3800; fax: +1-214-404-2333 Occidental Chemical Corp, Technology Center, 2801 Long Road, Grand Island, NY 14072, USA; tel: +1-716-773-8100 Occidental Chemical Europe SA, Holidaystraat 5, B-1831 Diegem, Belgium; tel: +32-2-715-6600; fax:+32-2-725-4676
354
Additives for Plastics Handbook
Oima SpA, Via Feltrina Sud 172, 31044 Montebelluna/TV, Italy; tel: + 3 9 - 4 2 3 6 0 0 5 4 1 ; fax:+39-423-24035 Olin Corporation, 120 Long Ridge Road, PO Box 1355, Stamford, CT 06904, USA; tel:+1-203-356-3036; fax:+1-203-356-3273 Olin Japan Inc, Shiozaki Bldg, 7-1 Hirakawa-cho 2-chome, Chiyoda-ku, Tokyo 102,Japan;tel:+81-3-263-4615; fax:+81-3-023-24031 OM Group Inc, 2301 Scranton Road, Cleveland, OH 4 4 1 1 3 , USA; tel: +1-216781-8383; fax:+1-216-781-5919 Omya GmbH, Brohler StraBe 11a, D-50968 Koln, Germany; tel: +49-221-3775-0; fax:+49-221-3718-64 Ore and Chemical Corp, 520 Madison Ave 2 7th Floor, New York, NY 10022, USA; tel:+1-212-715-5237; fax:+1-212-486-2742 Ormecon Chemie GmbH & Co KG, Ferdinand-Harten-StraEe 7, D-22949 Ammersbek, Germany Osi Specialties Inc, 39 Old Ridgebury Rd, Danbury, CT 06810-5124; tel: + 1 203-794-3402; fax: +1-203-794-3088 Otsuka Chemical Co, 2-2 7 Ote-dori 3-chome, Chuo-ku, Osaka 540, Japan; tel:+81-6-943-7711; fax:+81-6-946-0860 Overbeck Handelsgesellschaft mbH & Co, Breitenweg 29-33, D-28195 Bremen, Germany; tel: +49-421-3092-204; fax: +49-421-3092-337 Owens Corning Europe, Chaussee de la Hulpe, B 1170 Brussels, Belgium; tel:+32-2-674-8211-178;fax:+32-2-660-8572 Owens Corning World HQ, Fiberglas Tower, Toledo, OH 43659, USA; tel: + 1 419-248-8000 Oxford Instruments Inc. Analytical Systems Division, 130a Baker Avenue Extension, Concord, MA 01742, USA; tel: +1-508-371-9009; fax: + 1 508-371-0204 Oxyplast Belgium NV/SA, Nek-kersputstraat 189, D-9000 Gent, Belgium; tel:+32-9-216-8870; fax:+32-9-227-4116 P Pan Polymers Ltd, Unit K, Penfold Works, Imperial Way, Watford WD2 4YY, UK; tel:+44-923-211244; fax:+44-923-253530. Papenmeier GmbH Mischtechnik, Postfach 2140, D-32828 Augustdorf, Germany; tel: +49-5237-690; fax: +49-5237-692-31 Patco Polymer Additives, American Ingredients Co, 3947 Broadway, Kansas City, MO 64111, USA; tel: +1-816-561-9050; fax: +1-816-561-0422 PCD Polymere, DanubiastraSe 21-25, A-2323 Schwechat-Mannsworth, Austria; tel:+43-1-701-11; fax:+43-1-701-11-310 PCI, Yautepec 133, Col Condesa, Mexico DF 06140; tel: +52-5553-1172; fax: + 52-5256-3354 PCME Ltd, Clearview Building, Edison Road, St Ives PE17 4GH, UK; tel: +441480-468200; fax: +44-1480-463400 PEC GmbH, KonigstraSe 37-43, D-5202 Hennef 1, Germany; tel: +49-22425091; fax: +49-2242-1244
Appendix E: Directories
355
Penn-White Ltd, Radnor Park Trading Estate, CongletonCN12 4XJ, UK; tel: +441260-279-631; fax:+44-1260-278-263 Pergan GmbH, Schlavenhorst 71, D-46395 Bocholt, Germany; tel: + 4 9 - 2 8 7 1 99-020; fax: +49-2871-99-0250 Peroxid-Chemie GmbH, Dr-Gustav-Adolph-StraSe 3, D-82049 Pullach, Germany; tel: +49-89-74422-0; fax: +49-89-74422-203 Phillips Chemical Co, 411 Keeler, Bartlesville, OK 74004, USA; tel: + 1 - 9 1 8 - 6 6 1 4400; fax: +1-918-661-7636 Phillips Petroleum International NV, Haendorpweg 1 - Haven 122 7, B-9130 Kallo-Beveren, Belgium; tel:+32-3-570-2611; fax:+32-3-570-2626 Phipps Group, Unit 5, Hattersley Industrial Estate, Hyde, Cheshire SKI4 30T, UK; tel: +44-161-367-8789; fax: +44-161-367-8787 Pierce & Stevens Corporation, 710 Ohio Street (14072) Box 1092, Buffalo, NY 14240, USA; tel: +1-716-856-4910; fax: +1-716-856-7530 Pilot Industries, Technical Center, 2319 Bishop Circle East, Dexter, MI 48130, USA; tel:+1-313-426-4376; fax:+1-313-426-8160 Plalloy MTD BV, Postbox 3035, 6460 HA Kerkrade, The Netherlands; tel: + 3 1 45-546-4653;fax:+31-45-536-2523 Plastichemix Industries, 6 Kirti Towers, Tilak Road, Vadodara 390 0 0 1 , India; tel: +91-265-421-844; fax: +91-265-422-129 Plasticolors Inc, 2600 Michigan Avenue, Ashtabula, OH 44004, USA; tel: + 1 216-997-513 7; fax:+1-216-992-3613 Plastics Plus Ltd, Unit 9, Wulfrun Trading Estate, Stafford Road, Wolverhampton WV10 6HR, UK; tel:+44-902-715131; fax:+44-902-715096 Plast-0-Matic Valves Inc, 430 Route 46, Totowa, NJ 07512, USA; tel: + 1 - 2 0 1 256-3000; fax: +1-201-256-4745 Polar Minerals, 5060 North Royal Atlanta Drive, Suite 22, Tucker, GA 30084, USA; tel:+1-404-934-4411; fax:+1-404-934-43 76 Polycolour Plastics Ltd, Unit F l , Halesford 2 1 , Telford TF7 4NX, UK; tel: +441952-581814; fax:+44-1952-581815 Polymer Corp, 2120 Fairmont Avenue, PO Box 14235, Reading, PA 196124235,USA; tel:+1-215-320-6600; fax:+1-215-476-1196. Polymer Laboratories Ltd, Essex Road, Church Stretton SY6 6AX, UK; tel: +441694-723581; fax:+44-1694-722171 Polyplastics Co Ltd, Kasumigaseki Building, 3-2-5 Kasumigaseki, Chiyoda-ku, Tokyo 100,Japan; tel:+81-3-3593-2444; fax:+81-3-3580-0629 Polyrex Additives, Rte de Lausanne 23, CH-1400 Yverdon-les-Bains, Switzerland; tel: +41-24-2245-63; fax: +41-24-2245-64 Polyvel Inc, 120 N White Horse Pike, Hammonton, NJ 0803 7, USA; tel: +1-609567-0080; fax: +1-609-567-9522 Porous Plastics Ltd, 8 Little Park Farm Rd, Segensworth, Fareham P 0 1 5 5TB, UK; tel: +44-1489-577623. Portwood Colour Co. Ltd, 17-19 Rochdale Road, Bury BL9 OQB, UK; tel: +44161-764-5891; fax:+44-161-761-5763 Potters Industries Inc, Southpoint Corporate Headquarters, PO Box 840, Valley Forge, PA 19482-0840, USA; tel: +1-610-651-4700; fax: +1-610-408-9723
356
Additives for Plastics Handbook
Potters-Ballotini, Postfach 12 03 33, D-40603 Dusseldorf, Germany; tel: +49211-29608-0; fax:+49-211-29608-18 PPG Industries Fiber Glass BV, PO Box 50, NL-9600 AB Hoogezand, The Netherlands; tel:+31-5980-13911; fax:+31-5980-99649 PPG Industries Inc, One PPG Place, Pittsburgh, PA 15272, USA; tel: +1-412434-2261; fax: +1-412-434-2821 PQ Corporation, Box 840, Valley Forge, PA 19482, USA; tel: +1-610-651-4200; fax:+1-610-251-9124 Prayon-Rupel SA Societe Chimique, Gansbroekstraat 3 1 , B-2870 Puurs (Ruisbroek-Antwerp), Belgium; tel:+32-3-860-9200; fax:+32-3-886-3038 Precision Polymer Engineering Ltd, Clarendon Road, Blackburn BBl 9SS, UK; tel:+44-1254-679916; fax:+44-1254-680182 Premix Oy, PO Box 12, 05201 Rajamaki, Finland; tel: +358-0-290-1066; fax: + 358-0-290-3135 Provencale SA, 29 av Frederick Miatral, 83174 Brignoles Cedex, France; tel: +33-4-9472-8300; fax: +33-4-9459-0455 Priiftechnik AG, Oskar-Messter-Strafie 19-21, Postfach 1263, 8045 Ismaning, Germany; tel: +49-89-99616-0; fax: +49-89-99616-200.
Q Quantum Chemical Co, 11500 Northlake Drive, PO Box 429550, Cincinnati, OH 45249, USA; tel:+1-513-530-6500; fax:+1-513-530-6313 Quantum Materials, 9938 Via Pasar, San Diego, CA 92126, USA; tel: +1-619695-1716;fax:+1-619-695-0951 Quartz & Silice, BP 103, F-77793 Nemours Cedex, France; tel: +33-1-64454600; fax:+33-1-6428-4511 Quimica Roveri Commercial Ltda, Rua Alvaro Fragoso 344, Vila Carioca, Sao Paolo/SP04223-000,Brazil;tel:+55-11-2 74-3466; fax:+55-11-63-5659 R James Robinson Ltd, PO Box 83, Hillhouse Lane, Huddersfield HDl 6BU, UK; tel:+44-1484-435-577; fax:+44-1484-435-580 Raschig AG, Postfach 211128, D-6700 Ludwigshafen, Germany; tel: + 4 9 - 6 2 1 56180; fax:+49-621-5828-85 Raychem Ltd, Faraday Road, Dorcan, Swindon SN3 5HH, UK; tel: + 4 4 - 1 7 9 3 528171;fax:+44-1793-572276 Reagens, 1-40016 San Giorgio di Piano (Bologna), Italy; tel: +39-51-897-157; fax:+39-51-897-561 Redland Minerals, PO Box 2, Retford Road, Worksop S81 7QQ, UK; tel: +441909-537-800; fax:+44-1909-537-801 ReedSpectrum, Holden Industrial Park, Holden, MA 10520, USA; tel: +1-508829-6321 Reedy International Corp, 25 East Front St, Suite 200, Keyport, NJ 0 7 7 3 5 , USA; tel:+1-908-264-1777; fax:+1-908-264-1189
Appendix E: Directories
357
Reheis Inc, PO Box 609, 235 Snyder Ave, Berkeley Heights, NJ 07922, USA; tel: +1-908-464-1500; fax: +1-908-464-7726 Reichhold A/S, PO Box 2061,N3202 Sandefjord, Norway Reichhold Chemicals Inc, Research Triangle Park, NC 27709, USA; tel: +1-919990-7500 Reifenhauser GmbH, Spicher StraSe 46-48, 53839 Troisdorf-Sieglar, Germany; tel:+49-2241-4810; fax:+49-2241-408778 Reinhold Chemie AG, CH-5212 Hansen bei Brugg, Switzerland; tel: +41-56482-222; fax:+41-56-482-376 Repi SpA, Via del Vecchia Stazione 104-106, 1-21050 Gorla Maggiore (Va), Italy; tel:+39-331-614-001; fax:+39-331-619-537 Resart GmbH, Postfach 34 40, D-6500 Mainz, Germany; tel: +49-6131-631-0; fax:+49-6131-631-142 Research Development Corp, 2-5-2, Nagata-cho, Chiyoda-ku, Tokyo 100, Japan; tel: +81-3-3507-3052; fax: +81-3-3581-1486. Research Engineers Ltd, Orsman Road, London N l 5RD, UK; tel: +44-171-7397811; fax:+44-171-739-6615 Resinas Sinteticas, SA, Ctra. Olzinelles, s/n, E 08470 Sant Celoni, Spain; tel: +34-3-867-4000; fax: +34-3-867-2454 Recticel Nederland BV, Spoorstraat 69, 4041 CL Kesteren, Postbus 1, 4040 DA Kesteren,TheNetherlands; tel:+31-8886-9999; fax:+31-8886-2863. Rhein Chemie Rheingau GmbH, Postfach 81 04 09, D-68204 Mannheim, Germany; tel: +49-621-8907-0; fax: +49-621-8907-555 Rheochem Manufacturing Co, 775 Mountain Boulevard Ste 214, Watchung, NJ 07060, USA; tel: +1-908-757-0300; fax: +1-908-757-0607 Rheometric Scientific Ltd, Kiln Lane, Epsom KT17 IJS, UK; tel: +44-13 72743386; fax:+44-1372-727102 Rhone-Poulenc Chemicals, Secteur Specialites Chimiques, Cedex No 29, F-92097, Paris-La Defense, France; tel: +33-1-4768-1234; fax: +33-14768-1331 Rhone-Poulenc Chimie, Les Miroirs, La Defense 3, Cedex 29, 92097 Paris La Defense, France; tel: +33-1-47-68-1234; fax: +33-1-47-68-1911 Rhone-Poulenc Inc, CN 7500 Cranbury, NJ 08512-7500, USA; tel: +1-609860-4000 Rika International Ltd, 3C Brookside Business Park, Chadderton, Oldham M24 IGS, UK; tel:+44-161-655-4100; fax:+44-161-655-4200 Rim Cast, Cunliffe Drive, Kettering NN16 8LD, UK; tel: +44-536-510616; fax: +44-536-411236 Rite Systems, 1131 Douglas Road, Batavia, IL 60510, USA; tel: +1-630-8799700; fax: +1-630-879-9490 Roche Products Ltd, Heanor Gate, Heanor DE75 7SG, UK; +44-1773 536500; fax:+44-1773-536600 Rockware Plastics Ltd, Skerne Road, Kingston-upon-Thames, Surrey KT2 5AE, UK; teh +44-181-546-1161; fax: +44-181-547-0204 Rogers Corp, 1 Technology Drive, Rogers, CT 0 6 2 6 3 , USA; tel: +1-203-7749605;fax:+1-203-774-1973.
358
Additives for Plastics Handbook
Rogers Corporation, Molding Materials Division, PO Box 550, Manchester, CT 06045, USA; tel: +1-860-646-5500; fax: +1-860-649-2389 Rohm & Haas Co, Independence Mall West, Philadelphia, PA 19105, USA; tel:++l-215-592-3000 Rohm and Haas Co, Independence Mall West, Philadelphia, PA 19105, USA; tel:+1-215-592-3000 Rohm and Haas Deutschland GmbH, In der Kron 4, D-1000 Frankfurt/Main 90, Germany; tel: +49-69-789-960; fax: +49-69-789-5356 Rohm GmbH, Postfach 10 01 4 1 , D-64201 Darmstadt, Germany; tel: +496151-18-01; fax:+49-6151-18-02 Rosand Precision Ltd, Balds Lane, Lye, Stourbridge DY9 8SH, UK; tel: +441384-422991; fax:+44-1384-422755 Roth Scientific Co Ltd, Roth House, 12 Armstrong Mall, The Summit Centre, Farnborough, Hampshire GU14 ONR, UK; tel: +44-252-513131; fax: +44252-543609. RTP Co, 580 E Front Street, PO Box 5439, Winona, MN 55987-0439, USA; tel: +1-507-454-6900; fax: +1-507-454-8130 Ruhr-Chemie, HugenottenstraSe 105, Postfach 1429, D-6382 Friedrichsdorf, Germany; tel:+49-6172-733-283; fax:+49-6172-733-141 RV Chemicals Ltd, Widnes, Cheshire WAS OTE, UK; tel: +44-151-424-6101; fax:+44-151-420-4330 S A. Schulman Inc. 3550 West Market Street, Akron, OH 4 4 3 3 3 , USA; tel: + 1 216-666-3751 Sachtleben Chemie GmbH, Postfach 170454, D-47184 Duisburg, Germany; tel: +49-2066-22-0; fax: +49-2066-22-2000 Sandvik Process Systems Ltd, PO Box 3506 Manor Way, Halesowen B62 8QX, UK; tel:+44-121-550-7671 Sanyo Chemical Industries Ltd, 11-1 Ikkyo Nomoto-cho, Hashiyama-ku, Kyoto 605,Japan;tel:+81-75-541-4311;fax:+81-75-551-2557 Sarma, Via Lainate 26, lOOlO PogUano Milanese (Mi), Italy; tel: +39-2-93255363 Sartomer Co Oaklands Corporate Center, 468 Thomas Jones Way, Exton, PA 19341,USA;tel:+l-215-363-4117;fax:+1-215-363-4140 Satim, 57 Z.l route de Lesgor, 40370 Rion-des-Landes, France; tel: +33-58571887;fax:+33-5857-1718. Saudi Basic Industries Corp, PO Box 5 1 0 1 , Riyadh 11422, Saudi Arabia; tel: +966-1-401-2033; fax: +966-1-401-3831 SCJ Plastics Ltd, F-3/10-11, Okha Industrial area, Phase-1, New Delhi 119 020, india;tel:+91-ll-681-5566;fax:+91-11-681-4455 Scapa Polymeries, Columbine St, Manchester M i l 2LH, UK; tel: +44-161-3203636; fax:+44-161-335-0104 Schenck Ltd, Station Approach, Bicester 0X6 7BZ, UK; tel: +44-869-321321; fax:+44-869-321111.
Appendix E: Directories
359
Schering AG, Waldstrafie 14, D-4709 Bergkamen, Germany; tel: +49-2307651; fax: 49-2307-69805 Schuller Mats and Reinforcements, PO Box 517, Toledo, OH 43697-0517, USA; tel:+1-419-878-1504 SCM Chemicals - Asia/Pacific, Lot 4 Old Coast Road, Australind, WA 6230, Australia; tel:+61-97-251-261; fax:+61-67-252-504 SCM Chemicals - Europe, PO Box 26, Grimsby South Humberside DN3 7 8DP, UK; tel: +44-1469-571000; fax: +44-1469-571234 SCM Chemicals World HQ, 7 St Paul St, Suite 1010, Baltimore, MD 21202, USA; tel:+1-410-783-1120; fax:+1-410-783-1087 Scortec European Marketing, BTG, 101 Newington Causeway, London SEl 6BU, UK; Tel: +44-20 7403-6666; Fax: +44-20 7403 7586 Sekisui Chemical Co Ltd, 2-4-4, Nishi-Tenma, Kita-ku, Osaka 530, Japan; tel: 81-6-365-4122;fax:+81-6-365-4370 SFR Industries Inc, 652 Tower Drive, PO Box 3 70, Cadott, WI 5472 7-03 70, USA;tel:+1-715-289-4440; fax:+1-715-289-4446 SGL Carbon Group, Speciality Graphite Business Unit, DrachenburgstraKe 1, D-53170 Bonn, Germany; Tel: +49-228-841-0; Fax: +49-228-841-456 SGL Technik GmbH, Werner von Siemens Strage 18, Postfach 1233, D-86405 Meitingen, Germany; tel:+49-8271-832149; fax:+49-8271-832351 Shell International Chemical Co Ltd, Shell Centre, London SEl 7PG, UK; tel: +44-171-934-1234;fax:+44-171-934-5252 Sherwin-William Chemicals, 1700 W Fourth Street, Coffeyville, KS 673 3 7, USA; tel:+1-316-7276 Shimadzu Europa UK, Mill Court, Featherstone Road, Milton Keynes MK12 5RE, UK; tel:+44-1908-552200; fax:+44-1908-552211 Showa Denko KK, 1-13-9, Shiba-Daimon, Minato-ku, Tokyo 105, Japan; tel: + 81-3-5470-3111; fax:+81-3-3431-6442 Silberline Ltd, Banbeath Road, Leven, Fife KY8 5HD, UK; tel: +44-1333-424734; fax: +44-1333-421-369 Silicone Altimex Ltd, 49 Pasture Road, Stapleford, Nottingham NG9 8HR, UK; tel:+44-115-949-1413; fax:+44-115-949-0468 Simco (Nederland) bv, Postbus 11, NL-7240 AA Lochem, The Netherlands; tel:+31-5730-88333; fax:+31-5730-57319. Simeon Kunststofftechnische Software GmbH, D-52134 Herzogenrath, Germany; tel: +49-2407-5088; fax: +49-2407-59453 Sinloihi Co. Ltd, Kita-Yaesu Bldg, 3F 3-2-11 Nihonbashi, Chuo-ku, Tokyo, Japan;tel:+81-3-3281-1255;fax:+81-3-3281-1881 Sintex Ltd, Pavilion 3, Segensworth West, Fareham P015 5TB, UK; tel: +44489-577623;fax:+44-489-885325. Sintimid Hochleistungs Kunststoffe GmbH, Postfach 138, A-6600 Reutte/Tirol, Austria; tel: +43-5672-702625; fax: +43-5672-70501 SIPA SpA, Via Podgora, 31029 Vittorio Veneto TV, Italy; tel: +39-438-501447 SKWTrostberg AG, POBox 1262, D-83303 Trostberg, Germany; tel: + 4 9 - 8 6 2 1 86-2460; fax: 49-8621-86-2020 Slide Products Inc, PO Box 156, Wheeling, IL 60090, USA; tel: +1-708-541-7220
360
Additives for Plastics Handbook
SN2A, BP 98, F-13133 Berre TEtang, France; tel: +33-42-10-2242; fax: + 3 3 42-74-1015 SNCI, F-74490 Saint-Jeoire-en-Faucigny, France; tel: +33-50-35-9520; fax: + 33-50-35-9701 SNC-Lavalin, 2 Place Felix Martin, 14th Floor, Montreal, Quebec, Canada H2Z 1Z3; tel: +1-514-393-1000; fax: +1-514-954-0267. Snia BPD Group, Via Stabilimenti 11, 20020 Ceriano Laghetto (Mi), Italy; tel:+39-2-96161 Soarus LLC, 3930 Ventura Drive, Suite 440, Arlington Heights, IL 760004, USA; tel: +1-847-255-1211; fax: +1-255-4343 Solem Europe, PO Box 2 4 1 , NL-9640 AE Veendam, The Netherlands; tel: + 3 1 5987-51390; fax:+31-5987-51393 Solomat Partners LP, 652 Glenbrook Road, Stamford, CN 06906, USA; tel: + 1 203-977-8161; fax:+1-203-977-8237. Solutia Europe NV/SA, Rue Laid Burniat 3, Pare Scientifique - Fleming, B-1348 Louvain-la-Neuve (Sud), Belgium; tel: +32-10-48-13-21; fax: +32-10-4812-24 Solutia Inc, 10300 Olive Boulevard, PO Box 66760, St Louis, MO 63166-6760, USA; tel:+1-314-674-1000 Solvay Deutschland GmbH, Hanover, Germany; tel: +49-511-85 7-3023; fax: +49-511-857-2305. Solvay et Cie, Rue du Prince Albert 33, B-1050 Brussels, Belgium; tel: +32-2509-6111; fax:+32-2-509-51393 Solvay Engineered Polymers Inc, 1200 Harmon Road, Auburn Hills, MI 48326, USA; tel: +1-248-391-9500; fax: +1-248-391-9501 Sonics & Materials Inc, Kenosia Avenue, Danbury, CT 06810, USA; tel: +1-203744-4400; fax:+1-203-798-8350. Sorema SRI, Via Per Cavolto 17, 22040 Anzano del Parco, Como, Italy; tel: +3931-631637; fax:+39-31-631911. Stalo-Chemicals GmbH, Postfach 1606, D-49383 Lohne, Germany; tel: +494442-9430; fax: +49-4442-943-200 Statoil Petrochemicals & Plastics, Stig Mattsson, Poland; tel: +48-51-807872; fax:+48-51-805560. Struktol Co of America, 201 E Steels Corners Road Box 1649, Stow, OH 442240649 USA; tel: +1-216-928-5188; fax: +1-216-928-8726 Subhash Chemical Industries, S Block Shed W-2 MIDC, Bhosari Poona, 411026 MaharashtraState, India; tel:+91-212-790-632; fax:+91-212-792-554 Sudwest-Chemie GmbH, Postfach 2120, D-7910 Neu-Ulm, Germany; tel: +49731-70141; fax: +49-731-707-0764 Sulzer Technology Corp, Sulzer Marketing Services, Farnborough GU14 7LP, UK; tel:+44-1252-525336 Sumitomo Chemical Co Ltd, 4-5-33, Kitahama, Chuo-ku, Osaka 5 4 1 , Japan; tel:+81-6-220-3272; fax:+81-6-220-3345 Sun Chemical Corporation, 222 Bridge Plaza South, Fort Lee, NJ 07024, USA; tel: +1-201-224-4600; fax: +1-201-224-4392 Synco Sri, Via G Rossini 21,1-50041 Calenzano (Fi), Italy; tel: +39-55-8878-201
Appendix E: Directories
361
Syncoglas NV, Drukkerijstraat 9, B-9240 Zele, Belgium; tel: +32-52-457-611; fax:+32-52-449-502 Synthecolor SA, 7 rue des Oziers, ZI du Vert Galant, F-95310 Saint-Ouen L'Aumone, France; tel:+33-1-3440-3950; fax:+33-1-3464-0515 Thomas Swan & Co Ltd, Crookhall, Consett DH8 7ND, UK; tel: +44-1207-505131; fax:+44-1207-590-467 T Targor GmbH, RheinstraEe 4 G, D-55116 Mainz, Germany; tel: + 4 9 - 6 1 3 1 2070; fax: +49-6131-207-555 TEA Electro Conductive Products, PO Box 56, Rochdale 0L12 7EY, UK; tel: +441706-47718; fax:+44-1706-46170 Technical Fibre Products, Burneside Mills, Kendal, Cumbria LA9 6PZ, UK; tel:+44-1539-818264;fax:+44-1539-733850 Techno-Polymer, Postfach 1250, D-5982 Neuenrade, Germany; tel: +49-23926355; fax: +49-2392-64000 Tecnon Ltd, 12 Calico House, Plantation Wharf, York Place, London SWl 1 3TN; tel:+44-171-924-3955; fax:+44-171-978-5307 Teijin Ltd, 1-6-7, Minami-Honmachi, Chuo-ku, Osaka 541, Japan; tel: +81-6268-2132; fax:+81-6-268-3205 Teknor Apex International, 505 Central Avenue, Pawtucket, RI 0 2 8 6 1 , USA; tel:+1-401-725-8000 Tekuma Kunststoff GmbH, MoUner LandstralSe 75, D-2000 Oststeinbeck, Germany; tel: +49-40-712-0057 Telsonic AG, IndustriestraKe, CH 9552, Bronschhofen, Switzerland; Tel: + 4 1 73-225-353. Tempress Inc, 701 South Orchard, Seattle, WA 98108, USA; tel: +1-206-7621410 Tenax Fibers GmbH & Co KG, D-42097, Wuppertal, Germany; tel: +49-202-322338; fax: +49-202-32-2360 Ter Hell Plastic GmbH, Postfach 11648, D-4690 Heme, Germany; tel: +492323-496-10 Textron Inc, 40 Westminster Street, Providence, RI 0 2 9 0 3 , USA; tel: +1-401421-2800; fax:+1-401-421-2878 Thai Oleochemicals Co Ltd, 87 Yotha Road, Taladnoi, Sampantawong Bangkok 10100, Thailand; tel: +66-2-235-9565; fax: +66-2-235-8448 Thermofil Polymers (UK) Ltd, New Lane, Havant P09 2N0, UK; tel: +44-705486350; fax: +44-705-472388. Ticona GmbH, D 65926, Frankfurt am Main, Germany; tel: +49-69-305-3 73 7; fax:+49-69-305-83194 Tigerwerk Lack u Farbenfabrik GmbH, NegrellistraSe 36, A-4600 Wels, Austria; tel: 43-72-42-400; fax: +43-72-42-54476 TI-K VIV, Desguinlei 214, B-2018 Antwerpen, Belgium. Tintometer Co, Waterloo Road, Salisbury SPl 2JY, UK; tel: +44-1722-327-242; fax:+44-1722-412-322
362
Additives for Plastics Handbook
Tioxide International, Lincoln House 13 7-143 Hammersmith Rd, London W14 0OL,UK;tel:+44-20-7331-7746; fax:+44-20-7331-7711 Toho Chemical Industry Co Ltd, No 1-1-5 Shintomi, Nihonbashi, Chuo-ku, Tokyo 104,Japan;tel:+81-3-3555-3731; fax:+81-3-3555-3755 Tonen Chemical Corp, Togeki Building, 4-1-1, Tsukiji, Chuo-ku, Tokyo 104, Japan; tel:+81-3-3542-7361; fax:+81-3-5565-1402 Tool-Temp UK, 60-68 Tanners Drive, Blakelands, Milton Keynes MK14 5BP, UK; tel:+44-908-211718; fax:+44-908-216401. Toray Industries Inc, Toray Building, 2-1, Nihonbashi-Muromachi 2-chome, Chuo-ku, Tokyo 103,Japan; tel:+81-3-3245-5113; fax:+81-3-3245-5459 Toshiba Corp, 1-1-1, Shibaura, Minato-ku, Tokyo 105, Japan; tel; +81-3-3457 2104; fax: +81-3-3456-4776 Tosoh Corp, 1-7-7, Akasaka, Minato-ku, Tokyo 107, Japan; tel: +81-3-35853311; fax:+81-3-3582-7846 TowaChemicalCoLtd,Japan;tel:+81-6-723-5700; fax:+81-6-723-3509 Townsend Chemicals Pty Ltd, 114-126 Dandenong-Frankston Road, Dandenong VIC 3175, Australia; tel: +61-3-9793-6000; fax: +61-3-974-0723 Toyobo Co Ltd, 2-2-8, Dojimahama, Kita-ku, Osaka 530, Japan; tel: +81-6-3483111;fax:+81-6-348-3192 Tramaco GmbH, SiemensstraKe 1-3, D-25421 Pinneburg, Germany; tel: +494101-706-02; fax: +49-4101-706-200 Transpek Industry Ltd, KalahRoad, Atladra, Vadorara 390 012, India; tel: + 9 1 265-335-444; fax: +91-265-334-141 U Ube Europe GmbH, Nylon Resin Department, Germany; tel: +49-211-178-8325; fax:+49-211-361-3297 Ube Industries Inc, 315 E Eisenhower Ste 214, Anne Arbor, MI 48108, USA; tel:+l-313-769-5751 UCB SA, Chemical Sector, Specialities Group, Anderlecht Street 33, B-1620 Drogenbos, Belgium; tel: +32-2-334-5735; fax: +32-2-334-5924 Ulmer Fullstoff Vertrieb GmbH, Postfach 1240, D-7906 Blaustein, Germany; tel:+49-7304-8171; fax:+49-7304-8176 UMC International pic, Mayflower Close, Chandlers Ford Industrial Estate, EastleighS05 3AR, UK; tel:+44-703-269866; fax:+44-703-253198 Unichem Products, Divn of Colorite Polymers, 101 Railroad Avenue, Ridgefield, NJ07657,USA;tel:+1-201-941-2900; fax:+1-201-941-0308 Unichema Germany, Postfach 10 09 63, D-46429 Emmerich, Germany; tel:+49-2822-720; fax:+49-2822-72276 Unichema International, Postbus 2, 2800 Gouda, The Netherlands; tel: + 3 1 1820-42911;fax:+31-1820-42250 Unichema North America, 4650 South Racine Ave, Chicago, IL 60609, USA; tel:+1-312-376-9000; fax:+1-312-376-0095 Union Carbide Corporation, Old Ridgebury Rd, Danbury, CT 06817 USA; tel: + 1 203-794-2382; fax:+1-203-794-3088
Appendix E: Directories
363
Unipoly SA, Sherwood House II, 8a Upper High St, Winchester S23 8UT, UK; tel:+44-1962-878117;fax:+44-1962-878102 Uniqema, 30 Queen Anne's Gate, London SWl A 9AB, UK Uniroyal Chemical Co Inc, World Headquarters, Benson Road, Middlebury, CT 06749, USA; tel: +1-203-573-2000; fax: +1-203-573-2489 United Carbon India Ltd, NKM International House, Babubhai M Chinai Marg, Bombay 400 020, India; tel: +91-2021-914; fax: +91-285-0406 United Mineral and Chemical Corp, 1100 Valley Brook Ave, Lyndhurst, NJ 07071-3608, USA; tel: +1-201-507-3300; fax: +1-201-507-1506 Unitika Ltd, 4-1-3, Kita-Kyutaromachi, Chuo-ku, Osaka 5 4 1 , Japan; tel: +81-6281-5695; fax:+81-6-281-5697 US Borax, 26877 Tourney Road, Valencia, CA 91355-1847, USA; tel: +1-805287-5464; fax: +1-805-287-5545 US Gypsum Co, 125 S Franklin Street, Chicago, IL 60606, USA; tel: +1-312606-4018; fax: +1-312-606-4519 Uvalight Technology Ltd, 9th Floor, St. Martins House, Bull Ring, Birmingham B5 5DT, UK; tel: +44-21-643-2463/2472; fax: +44-21-643-3879. UVTEC Inc, 1121 108th Street, Arlington, TX 76011, USA; fax: +1-817-6400133. V Vanetti Colori, Viale Kennedy 856, 1-21050 Marnate (Va), Italy; tel: +39-331365-267;fax:+39-331-365-297 Velsicol Chemical Corp, 10400 W Higgins Road, Suite 600, Roesmont, IL 60018, USA; tel: +1-847-298-9000; fax: +1-847-298-3642 Vetrotex CertainTeed Corp, Fiber Glass Reinforcements, 750 E Swedesford Road, PO Box 860, Valley Forge, PA 19482, USA; tel: +1-215-341-7000; fax: + 1-215-293-1765 Vetrotex International, 767 Quai des Allobroges BP 929, F-73009 Chambery Cedex, France; tel: +33-79-75-5300; fax: +33-79-75-5405 Vinnolit Kunststoff GmbH, Carl-Zeiss-Ring 25, D-85737 Ismaning, Germany; tel: +49-89-96-1030; fax: +49-89-96-103103 Vista Chemical Co, PO Box 19029, Houston, TX 77224, USA; tel: +1-713-5883000; fax:+1-713-588-3119. Vulcan Catalytic Systems, High Point Road, PO Box 855, Portsmouth, RI02 8 71, USA; Tel: +1-401-683-2070; Fax: 1-401- 683-6450.
W Wacker Chemie GmbH, Hanns-Seidel-Platz 4, D-81737 Miinchen, Germany; tel:+49-89-62-7901; fax:+49-89-79-1770 Wayne Machine & Die Co, 100 Furler Street, Totowa, NJ 07512-1896, USA; tel:+1-973-256-7374; fax:+1-973-256-1778 Weko (UK) Ltd, Weko House, 2 Park Road, Kingston-upon-Thames KT2 6AY, UK; teh+44-81-549-8039; fax:+44-81-547-1119.
3 64
Additives for Plastics Handbook
Werner & Pfleiderer GmbH, TheodorstraEe 10, D-70469 Stuttgart, Germany; tel:+49-711-8970; fax:+49-711-897-3999 Westdeutsche Ouartzwerke Dr. Muller GmbH, Postfach 680, D-42 70 Dorsten, Germany; tel: +49-2362-200-50; fax: +49-2363-200-599 Whitford Plastics Ltd, Christleton Court, Manor Park, Runcorn, Cheshire WA7 ISU, UK; tel:+44-1928-571-000; fax:+44-1928-571-010 Wilson Color SA, 2 rue Melville Wilson, B-5330 Assesse, Belgium; tel: +32-83660-211; fax:+32-83-660-363 Wilson Colour & Additive Concentrates, 2 Rue de Tlndustrie, Zoning de la Fagne, B-5330 Assesse, Belgium; tel: +32-83-655-021; fax: +32-83-656-005 Windmoller & Holscher, Postfach 1660, 49516 Lengerich, Germany; tel: +495481-14-2929; fax:+49-5481-14-3355 Witco Corporation, One American Lane, Greenwich, CT 06831-2559, USA; tel: +1-203-552-3294; fax: +1-203-552-2886 Wittmann UK; 19 Faraday Court, Park Farm (North) Industrial Estate, Wellingborough NN8 6XY, UK; tel: +44-933-401455; fax: +44-933674116. WIZ Chemicals, Via G Deledda 11, 1-20025 Legnano (Mi), Italy; tel: + 3 9 - 3 3 1 545-654; fax: +39-331-546-900 WLT Ltd, 250 Thornton Road, Bradford BDl 2LB, UK Worlee Chemie GmbH, GrusonstraSe 22, D-22113 Hamburg, Germany; tel: +49-40-733-330; fax: +49-40-733-33296
Z Zeneca Specialties, PO Box 42, Hexagon House, Blackley, Manchester M9 8ZS, UK; tel: +44-161-740-1460; fax: +44-161-795-6005 Zipperling Kessler & Co, PO Box 1464, D-22904 Ahrensburg, Germany; tel: +49-4102-515-10; fax:+49-4102-487-169 Zoltek, Carbon and Graphite Divn, 3101 McKelvey Road, St Louis, MO 63044, USA; tel:+1-314-291-5110; fax:+1-314-291-8536 Zychem Ltd, 72 Grasmere Road, Gatley SK8 4RS, UK; tel: +44-161-428-9102; fax:+44-161-428-3686
Industry associations and federations
The following are associations and federations representing the plastics industry, for commercial and technical interests: Argentina CAIP Camara Argentina de la Industria Plasticoa, Jeronimo Salguero 1 9 3 9 / 4 1 , RA-1425 Buenos Aires Australia The Plastics Industry Association Inc, 4 1 - 4 3 Exhibition Street, Melbourne 2000
Appendix E: Directories
365
Austria FDCIO: Fachverband der Chemischen Industrie Osterreichs, Wiener HaupstraKe 63, POBox 325, A-1045 Vienna Belgium Belgian Plastics and Rubber Institute, c/o ABIC/BVR, Sqare Marie-Louise 49, B-1040Brussels;tel:+32-2-238-9778; fax:+32-2-231-1301. Fechiplast: Federation des Industries Chimiques de Beige, Square Marie-Louise 49, B-1040 Brussels Brazil ABIPLAST: Associacao Brasileira das Industrias Plasticos, Avenida Paulista 2 4 3 9 - 8 andar, 01311 Sao Paolo SP Canada SPI: Society of the Plastics Industry of Canada, 1262 Don Mills Road, Suite 104, Don Mills, Ontario M3B 2 W7 Chile ASIPLA: Asociacion de Industriales del Plasticos de Chile, Avda Pefro de Valdivia 1481, Casilla (POBox) 1460, Correo 2 1 , Santiago Czech Republic Polymer Institute Brno, Tkalcovska 2, 656 49 Brno; tel: +42-5-45-321-249; + 4 2 - 5 4 5 2 1 1 141 Denmark Plastindustrien i Danmark, Radhuspladsen 5 5, DK-15 50, Copenhagen V Finland FIPIF: FinskaPlastindustriforbundet, Mariankatu 26 B 9, SF-00170 Helsinki France SPMP: Syndicat Professionel des Producteurs de Matieres Plastiques, Tour Aurore, Cedex 5, F-92080 Paris-La Defense Franplast: Federation de la Plasturgie, 65 ruedeProny,F-75854Paris, Cedex 17 Symacap: Syndicat des Constructeurs Francais de Material pour le Caoutchouc et les Matieres Plastiques, 39/41 rue Louis Blanc, Cedex 72, F-92038 Paris-La Defense Germany AVK: Arbeitsgemeinschaft Verstarkte Kunststoffe eV, Am Hauptbahnhof 12, D-6000 Frankfurt/M. 1 AgPU: Arbeitsgemeinschaft PVC und Umwelt eV, Adenauerallee 45, D-53129 Bonn 1 DKI: Deutsches Kunststoff-Institut, SchloBgartenstrafie 6R, D-64289 Darmstadt
366
Additives for Plastics Handbook
EWVK: Entwicklungsgesellschaft fur die Wiederverwertung von Kunststoffen mbH, RheingaustraEe 190, D-6200 Wiesbaden GKV: Gesamtverband Kunststoffverarbeitende Industrie eV, Am Hauptbahnhof 12, D-60329 Frankfurt/Main 1 Institut fiir Kunststoffverarbeitung an der RWTH Aachen, Pontstrafie 49, D-5100 Aachen VKE: Verband Kunststofferzeugende Industrie eV, KarlstraEe 2 1 , D-60329 Frankfurt/Main 1 VDI-Gesellschaft Kunststofftechnik, PO Box 10113 9, D-4000 Dusseldorf 1 VDMA-Fachgemeinschaft Gummi- und Kunststoffmaschinen, Lyoner StraSe 18, D-6000 Frankfurt/Main Hungary Association of the Hungarian Plastics Industry, PO Box 40, 1406 Budapest 76 India AIPMA: All-India Plastics Manufacturers Association, Jehangir Building, 3rd Floor, 133 Mahatma Ghandi Road, Bombay 400 023 Ireland Plastics Industries Association, Confederation House, Kildare Street, Dublin 2 Israel Society of Israeli Plastics and Rubber Industries, 29 Hamered Street, PO Box 50022, Tel Aviv 61500 Italy Assoplast, Via Accademia 33,1-20131 Milan Unionplast, Via Pettiti 216,1-20149 Milan Assocomaplast, Centro Commerciale Milanofiori, Palazzo, F/2, Casella Postale 24, 20090 Assago Japan JPIF: Japan Plastics Industry Federation, Tokyo Club Building, 3-2-6 Kasumigaseki, Chiyoda-ku, Tokyo 100 Japan PVC Association, lino Building, 2-1-1, Uchisaiwai-cho, Chiyoda-ku, Tokyo 100 Korea (Republic) Korea Plastic Industry Cooperative, Korea Plastic Building, No 146-2, Sangrimdong, Choong-ku, Seoul Mexico ANIPAC: Asociacion Nacional de Industrias del Plastico, AC, Sullivan No. 165, A P 4, Mexico City 4, DF
Appendix E: Directories
367
The Netherlands NFK: Nederlandse Federatie voor Kunststoffen, Polanerbaan 15, Postbus 344, NL-3440AHWoerden TNO Centre for Polymeric Materials, Schoemakerstraat 97, NL-2 600 JA Delft New Zealand PINZ: New Zealand Manufacturers Federation Inc, Enterprise House, 3-9 Church Street (off Boulcott Street), Wellington 1 Norway Plastindustriforbundet, Parkveien 5, N-0350 Oslo 6 Portugal Associacao Portuguesa Industria Plasticos, rue d'Estefania 32-2, P-1000 Lisbon Romania Societer Comerciala ROMPLAST SA, Str Ziduri Mosi, Nr 23-25, Sector 2, 73342, Bucharest South Africa PES A: Plastics Federation of South Africa, PO Box 1128, Edenvale 1610 Spain ANAIP: Asociacion Espanola de Empresarios de Plasticos, Raimundo Fernandez, Villaverde 57, E-28003 Madrid Sweden Sveriges Plastforbund, Sveavagen 35-3 7, S-11134 Stockholm Foreningen Sveriges Plastfabrikanter, Torsgatan 2, S-111 85 Stockholm Switzerland ASKI: Arbeitsgemeinschaft der Schweizerischen Kunststoffindustri, NordstraBe 15, CH-8006 Zurich KVS: Kunststoff-Verband Schweiz, Schachenallee 29, CH-5000 Aarau VKI: Verband Kunststoffindustri der Schweiz, TurnerstraSe 10, CH-8033 Zurich Taiwan Taiwan Plastics Industry Association, 7th Floor, 162 Chang An East Road, Sec. 2 Taipei 104 Turkey State Statistics Institute, Necatibey Cad No 114, Ankara United Kingdom British Plastics Federation, 6 Bath Place, Rivington Street, London EC2 A 3JE Institute of Materials, 1 Carlton House Terrace, London SWIW 5DB
368
Additives for Plastics Handbook
United States of America International Institute of Synthetic Rubber Producers Inc - IISRP, 2077 South Gessner Rd, Suite 133, Houston, TX 77063-1123; tel: +1-713-783-7511; fax:+1-713-783-7253 Plastics Institute of America Inc, 2 7 7 Fairfield Road, Fairfield, NJ 07004-1932 SPI: Society of the Plastics Industry Inc, 12 75 K Street, N W, Suite 400, Washington, DC 20005 The Society of the Plastics Industry Inc, 355 Lexington Avenue, New York, NY 10017 European Union Association of Plastics Manufacturers in Europe - APME, Avenue E Van Nieuwenhuyse 4, B-1160 Brussels, Belgium BSEF: Bromine Science and Environmental Forum, 118 Av de Cortenbergh, 1000 Brussels, Belgium; tel: +32-2-733-93 70; fax: +32-2-735-6063 CEFIC: European Chemical Industry Council, Av E Nieuwenhuyse 4, Box 1, B-1160 Brussels, Belgium ECETOC: European Centre for Ecotoxicology and and Toxicology of Chemicals, Ave E Van Nieuwenhuyse 4, bte 6, B-1160 Brussels, Belgium ECVM: European Council of Vinyl Manufacturers, Ave E Van Nieuwenhuyse 4, Box 4, B-1160 Brussels, Belgium; tel: +32-2-675-2971; fax: +32-2-6753935 EUROMAP: European Committee of Machinery Manufacturers for the Plastics and Rubber Industries, Technical Committee; c/o VDMA e.V, Fachgemeinschaft Gummi- und Kunststoffmaschinen, PO Box 71 08 64, D-60498 Frankfurt, Germany European Centre for Plastics in the Environment, Ave E van Nieuwenhuyse 4, Box 5, B-1160 Brussels, Belgium ECPI: European Council for Plasticizers and Intermediates, Av E van Nieuwenhuyse 4, bte 2, B-1160 Brussels, Belgium; tel: +32-2-676-7260; fax:+32-2-676-7216 EFCTC: European Fluorocarbon Technical Committee, c/o CEFIC, Av E van Nieuwenhuyse 4, bte 1, B-1160 Brussels, Belgium; tel: +32-2-676-7211; fax:+32-2-676-7301 EuPC: European Plastics Converters Association, Ave de Cortenburgh 66, B-1000 Brussels, Belgium; tel: +32-2-732-4124; fax: +32-2-732-4218 AFPE: European Glass Fibre Producers' Assocation, 89 Avenue Louise, B-1050, Brussels, Belgium European Isocyanate Producers' Association, Ave E van Nieuwenhuyse 4, Box 1, B-1160 Brussels, Belgium ES-VOC-CG: European Solvents VOC Coordination Group, 4 Avenue Van Nieuwenhuyse, 1160 Brussels, Belgium; tel: +32-2-676-7264; fax: +322-676-7301 Eutraplast: Committee of Plastics Converters' Associations in W Europe, Rue Souveraine 97, B-1050 Brussels, Belgium
DATA SHEETS The following charts present basic data on different types of additive, based on data from manufacturers. Where possible, manufacturers' data have been harmonized, but there will be cases where data are not comparable. Data are presented as a guide to the general properties and applications of each material: specific points should be checked with potential suppliers. Fillers and extenders
Fillers and extenders
Calcium carbonate Description: Most widely used filler for plastics: forms vary according to geographical source. Surface treatments greatly improve properties and controlled particle size makes functional fillers possible: improved flow properties, low-profile anti-shrinkage, anti-blocking additives; treatment with aluminium trihydroxide (ATH) gives some flame retardancy Property
Typical grades
l^^nit
Chemical analysis
CaCOi
97.9
97.9
97.9
97.9
Specific gravity
g/cm^
2.7
2.7
2.7
2.7
Mohs hardness
3
3
pH value
9.1
8.5
8.5
9.0
2.2
2.2
3.2
2.2
Refractive index Specific surface
m^/g
Abrasion
g/m-
22-23
23
18
25
|im
0.8-20
0.8-2 5
0.8-10
0.8-20
g/lOOg
22
Loose bulk density
kg/m^
5 50-600
Tamped volume
kg/m^
750-800
Whiteness FMY
% % nS/cm
Particle size distr. Oil absorption
Moisture Conductivity
22 1790
1200
600
85
89.4
92.0
84.0
100
160
160
110
© 2001 Elsevier Science Ltd
3 70
Additives for Plastics Handbook
Fillers and extenders
Calcium carbonate Description: Most widely used filler for plastics: forms vary according to geographical source. Surface treatments greatly improve properties and controlled particle size makes functional fillers possible: improved flow properties, low-profile anti-shrinkage, anti-blocking additives: treatment with aluminium trihydroxide (ATH) gives some flame retardancy Property
Chemical analysis Specific gravity
Typical grades
Unit Vfine
Fine, easy dispense
Surface-coated
Coated easy dispense
CaC03
98
98
98
98
g/cm^
2.7
2.7
2.7
2.7
Mohs hardness
3
3
3
3
Refractive index
1.59
1.59
1.59
1.59
9
9
9
9
(im
1.6
2.7
2.4
5.5
g/lOOg
17
16
14
13
1.0
1.3
1.2
1.5
93.5
90.5
83
88
0.3
0.2
0.2
0.2
pH value Specific surface
m^/g
Abrasion
g/m^
Av. particle size Oil absorption Loose bulk density
kg/m^
Packed bulk density
g/cm^
Whiteness Ry Moisture Conductivity
% % }iS/cm
© 2001 Elsevier Science Ltd |
Datasheets
371
Fillers and extenders
Calcium carbonate Description: Most widely used filler for plastics: forms vary according to geographical source. Surface treatments greatly improve properties and controlled particle size makes functional fillers possible: improved flow properties, low-profile anti-shrinkage, anti-blocking additives; treatment with aluminium trihydroxide (ATH) gives some flame retardancy Property
Chemical analysis Specific gravity
Typical grades
Unit V fine/surface c
Ultrafine/surface c
Ultrafine/surface c
CaCOs
98
98
98
g/cm^
2.7
2.7
2.7
Mohs hardness
3
3
3
Refractive index
1.59
1.59
1.59
9
9
9
l^m
1.4
0.85
1.0
16
17
18
1.0
0.8
0.8
88
94
89
0.2
0.35
0.3
pH value Specific surface
m^/g
Abrasion
g/m^
Av. particle size Oil absorption
g/lOOg
Loose bulk density
Kg/m^
Packed bulk density
g/cm^
Whiteness Ry Moisture Conductivity
% % )iS/cm
© 2001 Elsevier Science Ltd
1
i 11
Additives for Plastics Handbook
Fillers and extenders
China clay Description: Water-washed china clay dehydrated to produce a very white extender, with high opacity Chemical analysis: Si02 = 55.3, AI2O3 = 42.6, Fe203 = 0.33, TiO- = 0.35,K2O = 0.70, Na20 - 0.08, CaO = 0.03, MgO - 0.07, P2O5 = 0.24, Mn02 0.01 Property
Unit
Specific gravity
g/ml
pH value
Typical grades 2.6
2.6
6-7
6-7
Specific surface
m^/g
4.0
4.2
Av. particle size
}xm
4.7
4.3
Sedimentation analysis: 10-40 j^m
% % %
12
10
80
82
8
8
g/lOOg
62
63
2-10 |im < 2 |im Oil absorption Loose bulk density Whiteness Ry Loss on ignition
g/ml
0.3
0.3
%
90.2
90.7
0.12
0.12
1
© 2001 Elsevier Science Ltd |
Datasheets
373
Fillers and extenders
Magnesium silicate Description: Extra-high-purity, high-whiteness platelet Chemical analysis: Si02 = 63.2, MgO = 3 1 . 7 , AI2O3 = 0.17, Fe203 = 0.03, CaO 0.01 1 Property Specific gravity
Unit g/ml
Typical grades 2.75
2.75
2.7
2.3
2.1
4.3
2.7
1 pH value Specific surface
m^/g
Av. particle size
)im
j Sedimentation analysis: 10-40 ^im 2-10 j^m < 2 [im
Oil absorption Tamped bulk density Whiteness Ry
% % %
41
31
74
60-55
59
69
26
5-2
58
48
41-33
g/lOOg g/ml
0.35
0.35
0.58
0.68-0.99
%
92
94
94
92
4.8
4.8
4.8
4.8 < 0.3
Loss on ignition Moisture
7-14 40-43
%
<
<
<
0.3
0.3
0.3 © 2001 Elsevier Science Ltd
3 74
Additives for Plastics Handbook
Fillers and extenders
China clay/kaolin Description: Finely elutriated kaolin, dehydrated to produce a low grain size fraction > 20 |im; used as very white filler clay in plastics, cable insulation and rubber Chemical analysis: Si02 = 55.1, Al203 = 42.7, Fe203 = 0.33, Ti02 = 0.35, K20 = 0.71, Na20 = 0.08, CaO - 0.20, MgO = 0.10, P2O5 = 0.20, Mn02 0.01 Property
Unit
Specific gravity
g/ml
pH value
Typical grades 2.6 6-7
Specific surface
m^/g
Av. particle size
\xm
1.7
Sedimentation analysis: 10-40 ^im
% % %
0.5
2-10 fxm < 2 ^m Oil absorption Loose bulk density Whiteness Ry Loss on ignition
g/lOOg
39.5 60
68
g/ml
0.3
%
91.5
1 1
0.20 © 2001 Elsevier Science Ltd |
Datasheets
375
Fillers and extenders
Aluminium silicates Description: Silane surface-modified calcined clays; very pure high brightness/low residue: clay/silane/polymer interaction improves tensile strength and compression set: used for cross-linked PE and polyester, EP elastomers; amino silane for mineral-filled PA Chemical analysis: Si02 = 51.0-52.4, AI2O3 = 4 2 . 1 - 4 4 . 3 , Fe203 = trace, Ti02 = 1.56-2.50 Property
Specific gravity
g/ml
pH value Specific surface
m^/g
Av. particle size
|am
Sedimentation analysis: 10-40 ^im
% % %
2-10nm < 2 )im
Oil absorption Loose bulk density Whiteness Ry
Vinyl silane
Amino silane
SiUcone
Proprietary silane
2.63
2.63
2.63
2.63
6.7-8.0
8.0-10.0
n/a
6.5-8.0
1.3
1.3
1.5
1.4
90-92
90-93
90-92
90-92
1.62
1.62
1.62
1.62
0-1.0
0-1.0
0-1.0
0-1.0
0.5
0.5
0.5
0.5
g/lOOg lb/ft ^
%
Refractive index Loss on ignition Moisture
Typical grades
Unit
%
© 2001 Elsevier Science Ltd
376
Additives for Plastics Handbook
Fillers and extenders
Aluminium silicate Description: Anhydrous aluminium silicates, aminosilane surface-treated: mineral-filled polyamides: low warpage/high impact Chemical analysis: Si02 51.0-52.4; AI2O3 4 2 . 1 - 4 4 . 3 ; FeOs trace; Ti02 1.56-2.50 Property
Unit
Specific gravity
Typical grades 2.63
Mohs hardness Refractive index
1.62 9.0-10.3
pH value Ignition loss
%
0-1.0
Specific surface Particle size
mm
1.3
Particle size distr. Oil absorption Loose bulk density Tamped volume GE brightness Moisture
90-93
%
0.5 (0 2001 Elsevier Science Ltd
Datasheets
377
Fillers and extenders
Aluminium silicates (anhydrous) Description: Aminosilane surface-treated grades, giving improvements in physical properties compared with untreated fillers, esp. low warpage, high impact strength: specially developed for mineral-filled polyamides: can also be used in polyesters, urethane, PVC and other thermoplastics: white colour 1 Chemical analysis: Si02 = 51.0-52.4, AI2O3 = 4 2 . 1 - 4 4 . 3 , Fe203 = trace, Ti02 = 1.56-2.50 1 Property
Unit
1 Specific gravity
g/ml
pH value
Typical grades 2.63
2.63
9.0-10.3
9.0-10.0
1.3
Specific surface
m^/g
Av. particle size
|im
1.3
Sedimentation analysis: 10-40 |im
% % %
63
2 - 1 0 |im < 2 }im
Oil absorption Loose bulk density Whiteness Ry
g/lOOg
18
Ib/ft^ 90-92
90-93
Refractive index
1.625
1.62
Loss on ignition
0-1.0
0-1.0
Moisture
%
%
1
0.5 © 2001 Elsevier Science Ltd |
378
Additives for Plastics Handbook
Fillers and extenders
Aluminium silicates (hydrous) 1 Description: Chemical analysis: Si02 = 44.8-45.3, AI2O3 = 37.5-39.7, Fe203 = trace, Ti02 = 1.35-2.27 Property
Specific gravity
Typical grades
Unit
g/ml
Fine particle
Ultrafine particle
Air floated
2.63
2.63
2.63
0.5-1.4
0.2
0.6-1.4
43-35
40
40-32
85-90
87-90
pH value Specific surface
m^/g
Av. particle size
|im
Sedimentation analysis: 10-40 |im 2-10 ^im < 2 [im
Oil absorption Loose bulk density Whiteness Ry
% % % g/lOOg lb/ft ^
%
77-82 1 1.56 1
Refractive index
1.56
1.56
Loss on ignition
13.7-14.1
13.7-14.1
13.7-14.1
1.0
1.0
Moisture
%
1.0
1
© 2001 Elsevier Science Ltd |
Datasheets
379
Fillers and extenders
White calcites Description: Crystalline and micro-crystalline calcites; surface modified with calcium stearate: used with PVC, UPVC extrusion, calendered sheet; injection moulding, PE cable compounds. Organic coating gives functional performance, high loadings possible Property
Specific gravity
Unit
Typical grades Microcrystalline
CrystaUine surface mod
CrystaUine surface mod
Crystalline surface mod
1.5
4.8
3.5
1.5
g/cm^
Mohs hardness Refractive index pH value Specific surface
m^/g
Abrasion
g/m^
Particle size: average -maximum -less than 2 jam Oil absorption DOP absorption
|am jim
6
25
15
6
wt%
65
30
35
65
g/lOOg
29
14
16
17
33
18
15
19
94
93
93.5
95
g/lOOg
Loose bulk density
kg/m^
Packed bulk density
g/cm^
Dry brightness Moisture Conductivity
% %
'
|aS/cm © 2001 Elsevier Science Ltd |
380
Additives for Plastics Handbook
Fillers and extenders
Calcined clays Description: Surface-modified, high brightness low residue calcined kaolin, giving direct reaction 1 with compatible polymer compounds in presence of a peroxide Chemical analysis: Si02 51.0-52.4; AI2O3 4 2 . 1 - 4 4 . 3 ; FeOs trace; Ti02 1.56-2.50 Property
Typical grades
Unit
Specific gravity
Vinyl silane
Aminosilane
Silicone
Prop, silane
2.63
2.63
2.63
2.63
1.62
1.62
1.62
1.62
6.7-8.0
8.0-10.0
n/a
6.5-8.0
Mohs hardness Refractive index pH value Ignition loss
%
0-10
Specific surface Particle size 325 mesh residue
mm
1.3
1.3
1.5
1.4
% max
0.04
0.02
0.03
67
65
63
0.03 60
90-92
90-93
90-92
90-92
0.5
0.5
0.5
0.5
Oil absorption
1 1
Loose bulk density Tamped volume GE brightness Moisture
%
Notes: Cross-linked polyethylene and polyester systems, EPR, EPT: amino silane-treated for mineral-filled PA © 2001 Elsevier Science Ltd |
Datasheets
381
Fillers and extenders
Magnesium silicate (talc) Description: Micronized from high purity steatitic source, giving very high brightness: highly laminar, with high aspect ratio, for higher stiffness Chemical analysis: MgO 32.22; Si02 61.39; CaO 0.38% Property
Typical grades
Unit 5030
2050/
Specific gravity
lO/lOP/20
45/70
2.7
2.7
7-14
Mohs hardness Refractive index pH value
8.2
8.2
Particle size
5-lOM
2-3 7 M
2.1-4.3 mm
Particle size distr.
1.5-3 M
5-8 M
1-20 mm
Oil absorption
42-50
30-37
48-58
10% sol
Specific surface
Loose bulk density
g/ml
Tamped volume
g/ml
Dry brightness Moisture
%
2-45
0.18-0.28
41-33 1 0.35-0.52 1
0.35-0.58
0.68-0.99
91-96
80-86
92-94%
0.2
0.2
< 0.3 g/ml
92 <0.3
1 1
© 2 001 Elsevier Science Ltd |
382
Additives for Plastics Handbook
Fillers and extenders
Mica Description: Property
Unit
Typical grades G/GH
N
SG
SFG
Chemical analysis 2.85
2.85
2.85
2.85
Mohs hardness
2.5
2.5
2.5
2.5
Refractive index
1.56
1.56
1.56
1.56
9.5
9.5
9.5
9.5
8
10
7
12-21
Specific gravity
g/cm^
pH value Specific surface
m^/g
1:20-1:30
1:20-1:30
1:20-1:30
1:20-1:40
|im
11-5.4
9.4-4.6
14.5-7.4
9.2-2.7
g/lOOg
28
31
25
41-43
Aspect ratio Particle size distr. Oil absorption
g/1
490
460
500
3 70-200
Tamped volume
g/1
860
860
890
740
Whiteness FMY
% %
76-81
77-82
75-80
80-87
91
91
66
172-225
Loose bulk density
Moisture Conductivity
fiS/cm
© 2001 Elsevier Science Ltd
Datasheets
383
Fillers and extenders
Muscovite mica Chemical analysis (%): Si02 46.5; AI2O3 35.7; Na20 8.8; FeOs 2.1 Grade 5
Grade 10
Grade 45
~2.8
~2.8
~2.8
Mohs hardness
2.0-2.5
2.0-2.5
2.0-2.5
Refractive index
1.58
1.58
1.58
pH value
7-9
7-9
7-9
m^/g
> 18
> 15
> 5
\im
5.5
8.0
36.0
Particle size dist. dgy
|im
< 12
< 16
< 64
Loss on ignition (%)
1100°C
~5
~5
-5
% %
r^77
-75
~65
< 1.0
<0.6
Specific gravity
Specific surface Particle size dist. dso
Whiteness FMY Moisture
g/cm^
< 1.5
© 2001 Elsevier Science Ltd
384
Additives for Plastics Handbook
Fillers and extenders
Wollastonite Description: Natural p-wollastonite changes to a-type on heating to 1100°C; synthetic grade is a-wollastonite, has very low loss on ignition, retains crystal structure during heating, giving constant chemical composition Chemical analysis: CaO = 47.5, Si02 = 51.0. Fe203 = 0.4, AI2O3 = 0.2, MnO = 0.1: -(synthetic): CaO = 45.2, Si02 = 52.5, MgO = 0.6, Fe203 0.3, AI2O3 = 0.3 Property
Typical grades
Unit High aspect
Specific gravity
g/cm^
Molecular weight
325-400 mesh
Fine particle size
Synthetic grade ~2.9
2.9
2.9
2.9
116
116
116
Mohs hardness
4.5
4.5
4.5
Refractive index
1.63
1.63
1.63
pH value
9.9
9.9
9.9
Specific surface
~5
11-11.5 1
m^/g
~0.7
Particle size: average
Hm
17-70
-US screen max
% %
- 1 0 0 = 99
- 3 2 5 = 99
-20=100
- 3 2 5 = 65
- 4 0 0 = 98
- 1 0 = 96
g/lOOg
45
20-22
32
Loose bulk density
kg/m^
0.40
0.72-0.64
0.48
Packed density
g/cm^
0.80
1.12-0.96
0.80
GE brightness
% %
85
94
95
> 83* 1
1000°C
< 1.0
< 1.0
< 1.0
~0.4 1
- US screen min Oil absorption
Moisture Loss on ignition
18
1
~1.0
< 0.3 © 2001 Elsevier Science Ltd |
385
Datasheets
Functional fillers
Magnesium silicate hydrate Description: High purity, high whiteness; micronized to various particle size distributions, maintaining extreme lamellarity with high aspect ratio Chemical analysis: Si02 62; AI2O3 0.3; MgO 31.2; FeOs 0.1% 1 Property Specific gravity
Unit
Typical grades
Extender
g/cm^
2.77
2.77
2.77
2.77
Mohs
~1
~1
~1
^1
Refractive index
1.57
1.57
1.57
1.57
pH value
~9
~9
~9
~9
>22->13
>9->5
>3->3.5
>22
dsodgy
0.9-1.9 <5-<10
3.5-5<25
10-8 < 4 5
0.9 < 5
Loss on ignition
1100°C
<6%
<6%
<6%
~6%
Whiteness ISO
% %
~97-96
-96-95
~95
~97n
<0.5
Hardness
Specific surface 1 Particle size Particle size distribution
m^/g |j.m
(lim)
Oil absorption Loose bulk density
Moisture
< 0 . 2 - < 0.3
<1
© 2 0 0 1 Elsevier Science Ltd |
386
Additives for Plastics Handbook
Reinhrcemerits,
fibrous and
microspheres
Reinforcements
Glass fibre Description: The main fibrous reinforcement for thermoplastics and thermosets, giving high tensile strength but low stiffness: sizing/coupling agents give better bond: used for thermoplastics, longer 1 fibres giving higher reinforcement; long, continuous, mat or woven fibres used for thermosets Property
Density
Unit
g/cm^
Bulk density Mohs hardness
Typical grades E-glass
R-glass
Quartz
2.5
2.5
2.2
2.60-2.82
2.55
6.5
Tensile strength
MPa
2400
3450
3700
Flexural modulus
GPa
69
86
69
Specific modulus
Mm
27
34
31
%
4.4-4.5
5.2
0.22
-
Elongation (break) Poisson's ratio
lQ-f>Op-l
2.80
2.30
Refractive index
at25°C
1.55-1.566
1.541
UV transmission
at25°C
opaque
Volume resistivity
Qcm
17.7-10.4
Dielectric constant
^cm
6.5-7.0
Coeff. therm, exp.
Alkalinity Solvent resistance Alkali resistance Acid resistance
6.0-8.1
Na20 %
0.3
0.4
% % %
good
good
good
good
exc. hydrofluoric
exc. hydrofluoric © 2001 Elsevier Science Ltd |
Datasheets
387
Reinforcements
Glass fibre Description: The main fibrous reinforcement for thermoplastics and thermosets, giving high tensile strength but low stiffness: sizing/coupling agents give better bond: very short fibres used for thermoplastics (injection moulded); longer fibres giving higher reinforcement now becoming accepted; long, continuous, mat or woven fibres used for thermosets Property
Tensile strength
Typical grades
Unit E-glass
R-glass
3331
3330
3185
3240
MNm^
I -virgin fibre 23°C - virgin fibre 100°C
5320
5280
Modulus of elasticity
GNm^
72.5
72.5
Density
gcm^
2.52-2.62
2.70-2.72
1.556
1.576
-virgin fibre 196°C
Refractive index Coeff. linear thermal expansion
1/°C
5.0x10-^
5.9x10-^
Diel. constant: - 60 Hz
23°C
6.4
7.1
6.2
7.0
23°C
0.003
0.004
0.004
0.003
- 1 0 ^ Hz Loss tangent 60 Hz - 1 0 ^ Hz Volume resistivity: - 5 0 0 V DC Dielectric strength (kV mm)
^/cm23°C
10^4
10^4
9.80
9.96
© 2001 Elsevier Science Ltd
388
Additives for Plastics Handbook
Reinforcements
Carbon fibre Description: High performance/high stiffness: used with high performance engineering thermoplastics (injection moulding), but mainly with thermosetting resins, as long/continuous fibre reinforcement, often woven or with other fibres Property
Density
Unit
Typical grades
g/cm^
HT
IM
HM
UHM
1.8
1.8
1.8
2.0
Tensile strength
MPa
3500
5300
3500
2000
Flexural modulus
GPa
160-270
270-325
325-440
440+
Specific modulus
Mm
90-150
150-180
180-240
200+
© 2 001 Elsevier Science Ltd
Reinforcements
Aramid fibre Description: High performance fibre, high stiffness, low weight: used esp. in composites with other fibres: also developed as chopped fibre, powder additive or masterbatch for improved lubrication/wear resistance in injection moulded engineering thermoplastics Property
Typical grades
Unit LM
HM
UHM
g/cm^
1.45
1.45
1.47
Tensile strength
MPa
3600
3100
3400
Flexural modulus
GPa
60
120
180
Specific modulus
Mm
40
80
120
Density
© 2001 Elsevier Science Ltd
Datasheets
389
Reinforcements
Glass spheres (solid) Description: Solid soda-lime glass: used as reinforcing filler in thermoplastic and thermosetting moulding compounds: improves stiffness, heat distortion, shrinkage; can also improve flow properties: grades differentiated by size (90% beads of designated diameter): other size ranges are produced Property
Unit
Typical grades 3-80 ^im
0.5-19.3 |im
2.45 2.55
Specific gravity Hardness
0.8-70 ^im
Mohs
6 1.51-1.52
Refractive index Av diameter
\xm
27-36
12-26
3.5-7.0
Surface area
m^/cm^
0.40-0.80
1.05-1.75
1.75-3.30
Oil absorption
g/lOOg
17
/K
7.75 10-^
Tensile modulus
N/mm^
6.89 10^
Flexural modulus
N/mm^
2.96X
Coeff. thermal exp
0.21
Poisson's ratio Volume resistivity
Gfim
300
Dielectric strength
kV/cm
4500
Dielectric constant
IKHz
7.6
Power factor
0.9 © 2001 Elsevier Science Ltd |
390
Additives for Plastics Handbook
Reinforcements
Glass spheres (hollow) Description: Hollow borosihcate glass: white powder, spherical, non-porous; low alkah leach, insoluble in water: hghter weight than solid glass; can be damaged in moulding process, but 1 properties of compound are still useful Property
Unit
Typical grades
1 Chemical analysis: Specific gravity
1.08
Crush strength (% volume loss)
3000 psi lOOOOpsi
neglig. 13%
1 Colour value
90.0 min
Av diameter
8.4
Particle size distr.
Surface area
10% 50% 90%
4.2 8.7 14.0
m^/ml
0.47
pH value
8.3
Conductivity
52
mmoh/cm
Notes: In a variety of thermoplastics, good whiteness/opacity suggests possible use as low-cost pigment extender © 2001 Elsevier Science Ltd
Reinforcements
Thermoplastic spheres (expandable) Description: Gas-filled thermoplastic spheres, expanding at processing temperature: can form useful syntactic foam structure Approx. solid content (%) WU 65
67
65
63
Number average
5-8
5-8
5-8
3-5
Weight average
10-16
10-16
10-16
6-9
°C
81-96
90-95
99-104
99-104
Particle size average
mm
Thermomechanical Tstart
T
°C
122-132
132-140
142-150
136-144
TMA density
kg/m^
<25
<17
<17
<25
Residual monomer CAN
mg/kg
<100
<150
<150
<150
**
***
***
Solvent resistance
*
Key: solvent resistance: * fair; ** good; *** very good; ****excellent © 2001 Elsevier Science Ltd
|
Datasheets
391
Reinforcements
Thermoplastic spheres (expandable) Description: Gas-filled thermoplastic spheres, expanding at processing temperature: can form useful syntactic foam structure Approx. solid content (%) WU 63 Particle size average
60
60
65
mm
Number average
6-10
4-7
3-5
5-8
Weight average
18-24
9-15
6-9
9-15
Thermomechanical Tstart
°C
99-104
104-110
104-110
112-117
T
°c
145-155
144-152
140-148
146-154
J-max
TMA density
kg/m^
<20
<20
<20
<25
Residual monomer CAN
mg/kg
<150
<150
<150
<300
***
****
****
****
Solvent resistance
Key: solvent resistance: * fair; **; good; *** very good; **** excellent © 2001 Elsevier Science Ltd |
Reinforcements
Thermoplastic spheres (expandable) Description: Gas-filled thermoplastic spheres, expanding at processing temperature: can form useful syntactic foam structure Approx. solid content (%) WU 75 Particle size average
75
70
mm
Number average
6-9
8-12
10-20
Weight average
10-16
18-24
18-24
Thermomechanical Tstart
°C
99-104
99-104
124-132
T
°C
142-150
146-154
178-188
TMA density
kg/m^
<20
<17
<17
Residual monomer CAN
mg/kg
<300
<300
<400
***
***
****
Solvent resistance
Key: solvent resistance: * fair; ** good; *** very good; **** excellent © 2001 Elsevier Science Ltd
392
Additives for Plastics Handbook
Pigments, colorants, whites, blacks Pigments
Inorganic Description: Based on iron oxide: strong bright colours Unit
Property
Typical grades Ferrox red
Ferrox yellow
Ferrox black
Ferrox brown
Chemical analysis
Fe203
90-98
82-88
58-97
91-96
Specific gravity
g/cm^
4.8-5.1
4.0-5.2
4.6-4.8
4.4-4.8
Tamped density
g/cm^
0.6-1.7
0.3-1.0
0.8-1.5
0.6-1.3
spherical
acicular
spherical
irregular
4-8
3.5-10
4-10
4-8.5
Av. particle size Particle shape pH value
15-28
16-60
15-21
22-30
0.3-3.0
11-15
2.0-4.0
1.5-6.0
Oil absorption Heat resistance
%loss, 1000°C
Fastness: light Fastness: weather (0 2001 Elsevier Science Ltd |
Pigments
Inorganic Description: Chrome; and specialities Property
Unit
Typical grades Chrome oxide
Lightfast
Heat-resistant
5.2
3.8-4.6
3.8-5.2
5.0
Anti-corrosion
Chemical analysis Specific gravity Tamped density Av. particle size
Jim
Particle shape pH value Oil absorption Heat resistance
% loss, 100°C
1.0-1.3
0.5-1.4
0.4-1.2
1.1-1.3
0.3-0.35
0.1-0.6
0.1-0.7
0.12
spherical
spherical/ prismatic
acicular
spherical
5-10
7-10
3.5-10
7-11
11
15-35
14-65
22
0.4
0.5-3.0
0.5-15
Fastness: light Fastness: weather © 2001 Elsevier Science Ltd
Datasheets
393
Pigments
Inorganic Description: Based on mixed metal oxides, ground to optimum fine particle size: good colour 1 strength, resistance to heat Property
Unit
Typical grades Yellow
Brown
Blue
Green
4.50-4.70
4.66-5.60
3.82-4.60
4.53-5.26
0.68-1.30
0.66-2.60
0.90-1.40
1.20-1.70
Chemical analysis Specific gravity Tamped density Av. particle size Particle shape 7.0-10.0
4.0-8.3
7.9-10.3
6.7-9.7n
14.0-23.3
15.0-29.0
17.0-56.0
17.0-29.0!
1000
500-1000
1000
1000
Fastness: light
8
8
8
8
Fastness: weather
5
5
5
5
pH value Oil absorption Heat resistance
°C
1
© 2001 Elsevier Science Ltd |
Pigments
Inorganic Description: Based on mixed metal oxides, ground to optimum fine particle size Property
Typical grades
Unit Violet
Black
3.70-3.80
5.0-5.31
0.90-1.10
0.40-3.90
7.2-7.5
6.9-9.5
Chemical analysis Specific gravity Tamped density Av. particle size Particle shape pH value
22.0-23.0
15.2-33.0
450
800-1000
Fastness: light
8
8
Fastness: weather
5
5
Oil absorption Heat resistance
°C
© 2001 Elsevier Science Ltd
394
Additives for Plastics Handbook
Pigments
Organic 1 Description: Property
Typical grades
Unit
Structure Colour shade
a-Blue
a-Blue
p-Blue
Barium
crystallng.
non-cryst.
non-cryst.
red
red
green
red
4
4
4
4
Solvent fastness: -Xylene 1 -Ethanol -MEK
5
5
5
4
5
5
5
4 5
-Min. spirits
5
5
5
- Water
5
5
5
5
1
°C
204-220
260-288
260-274
274
1
op
400-425
500-550
500-525
525
7-S
7-8
7-8
4-5
Heat resistance Fastness: light Fastness: weather
Key: solvent resistance: 5 = insoluble/1 = very soluble: light fastness: 10 = no change/2 = strong change: figures are for full-tint © 2 0 0 1 Elsevier Science Ltd |
Datasheets
395
Pigments
Organic Description: (based on Cookson data) Property
Typical grades
Unit Calcium
Calcium
Naphthol
Naphthol
opaque
transpt.
opaque
transpt.
red
red
red
red
- Xylene
5
4-5
4
4
-Ethanol
4
4
4
4
\
-MEK
5
5
4
4
\
1
Structure Colour shade Solvent fastness:
-Min. spirits
5
5
5
5
-Water
5
5
5
5
260-274
260-274
191
191
500-525
500-525
375
375
6-4
6-4
8-6
7-5
Heat resistance
°C op
Fastness: light
1
Fastness: weather Key: solvent resistance: 5 = insoluble/1 = very soluble; light fastness: 10 = no change/2 = strong change; figures are for full-tint © 2001 Elsevier Science Ltd |
Pigments
Pearlescent Description: Coated particles giving pearlescent and other light effects by internal refraction/interference patterns: popular for moulded cosmetics packs Property
Density Bulk density Av. particle size
Unit
Interference
Gold lustre
Metal lustre
g/cm^
2.7-3.3
3.1-3.7
2.8-3.3
2.9-3.7
g/lOOml
17-40
31-49
27-42
25-37
}xm
1-180
5-60
5-100
5-125
4-11
8-11
6-11
3-7
50-80
40-65
40-75
45-65
anatase/rutile
rutile
anatase/rutile
-
pH value Oil absorption Modification Ti02
Typical grades Silver
g/lOOg
© 2001 Elsevier Science Ltd
396
Additives for Plastics Handbook
Pigments
White: titanium dioxide Description: The main white pigment for plastics, used on its own as a brilliant white, also for modification of coloured pigments: relatively expensive, can be supplemented by less costly whites: data are for high purity grades for plastics Property
Ti02
Unit
Typical grades Neutral
Blue
High brightness
Durable/ brightness
98.7
98-7-96.5
96.5-98.5
91.2
1.0
1.0-3.0
3.2-1.0
3.3
wt%
Alumina Silica Organic treatment
-
-
-
5.5
yes
yes
yes
no
4.2
4.2
4.1-4.2
3.9
Colour
CIEL
98.5-99.2
99.2
99.2-99.0
99.6
Av. particle size
mm
0.32-0.29
0.29-0.23
0.22
0.35
Specific gravity
Oil absorption
11.0
11.0-14.0
14.0
102-110
110
110
-0.040
0.035
g/lOOg
Vinyl tint strength Vinyl undertone
18.0 1 90 1 -0.030 1
0.035-030
(0 2 001 Elsevier Science Ltd |
Pigments
Carbon black Description: Main characteristics of carbon black, produced by various manufacturing processes (n/a = not applicable: pH may drop as low as 2 for oxidized blacks) Property
Unit
Thermo-oxidative decomposition processes Lampblack
Gas black (Degussa)
Furnace black
16-24
90-500
15-450
Nitrogen surface area
m^/g
Iodine adsorption
mg/g
23-33
n/a
15-450
Mean particle size
|im
110-120
10-30
10-80
ml/lOOg
100-120
n/a
40-200
g/lOOg
250-400
220-1100
200-500
My
200-220
230-300
210-270
Tinting strength
IRE 3 = 100
25-35
90-130
60-130
Volatile content
%
1-2.5
4-24
0.5-6
6-9
4-6
6-10
DBP absorption Oil absorption Jetness
pH value
© 2001 Elsevier Science Ltd
Datasheets
397
Pigments
Carbon black Description: Main characteristics of carbon black, produced by various manufacturing processes (n/a = not applicable: pH may drop as low as 2 for oxidized blacks) Unit
Property
Thermal decomposition processes Thermal
Acetylene
6-15
~65
Nitrogen surface area
m^/g
Iodine adsorption
mg/g
6-10
~100
Mean particle size
?m
120-500
32-42
ml/lOOg
DBP absorption Oil absorption Jetness
37-43
150-200
g/lOOg
65-90
400-500
My
170-190
225
Tinting strength
IRB3 = 100
~20
n/a
Volatile content
%
0.5-1.0
0.5-2.0
7-9
5-8
pH value
1
© 2001 Elsevier Science Ltd |
Pigments
Carbon black Description: Furnace grades - used mainly for colour and UV shielding Property
Unit
High strength
Medium strength
UV protection
Fine grain/UV
Nitrogen surface area
m^/g
240-560
200-210
115
140
|im
13-16
17-18
22
20
65-117
114
113
Mean particle size DBP absorption Oil absorption
ml/100 g
50-105
g/lOOg
Colour depth
index
69-60
78-73
88
87
Tinting strength
index
140-109
148-150
115
123
Volatile content
%
2.0-9.5
1.5
1.5
1.5
2.5-7.0
8.0
8.5
9.0
pH value Tamped density: - powder -beads
g/l
176-273
144-240
230
230
g/1
385-465
304-430
335
344
© 2001 Elsevier Science Ltd
398
Additives for Plastics Handbook
Pigments
Carbon black Description: Furnace grades, used for colour Property
Unit
Highest strength
General purpose
Nitrogen surface area
m^/g
112
84
35
jim
24
27
50
ml/lOOg
60
102
91 96
Mean particle size DBP absorption
Economy grade
Oil absorption
g/lOOg
Colour depth
index
83
90
Tinting strength
index
137
103
59
Volatile content
%
1.0
1.0
1.0
7.5
8.5
8.5
230
435 1
pH value Tamped density: -powder
g/1
240
-beads
g/1
497
368
© 2001 Elsevier Science Ltd |
Datasheets Antioxidants
399
and stabilizers: heat and light
Stabilizers
Anti-oxidants (primary) Description: Sterically hindered phenols (radical scavengers): good high-temperature, long-term thermal stabilizers; good resistance to discoloration and extraction Property Appearance Specific gravity
white powder
TGAat20°C/min
white powder
white powder
white powder
1.15
1.0-1.02
1.05-1.21
1.11-1.13
1178
643-531
775-695
553-784
110-125
50-68
241-260
218-229
l%loss
310
270-230
290-280
240-280
10% loss
355
310-290
340-315
280-330 1
g/ml
Molecular weight Melting range
Typical grades
Unit
°C
© 2001 Elsevier Science Ltd
Stabilizers
Antioxidants (secondary) Description: Thioethers (long-term stability of polyolefins); phosphite/phosphonite (superior processing stability): both with phenolic antioxidants Property
Unit
Appearance Specific gravity
G/ml
Molecular weight Melting range TGAat20°C/min
Typical grades Thioethers
Phosphite/ phosphonite
white powder
white powder
white powder
off-white powder
1.04
0.98
1.03
1.06
515
683
647
991
°C
39-41
63-66
180-186
85-110
1 % loss
180
210
230
170
10% loss
280
260
260
275
© 2001 Elsevier Science Ltd
400
Additives for Plastics Handbook
Stabilizers
Lead-based stabilizers 1 Description: Master compounds for PVC extrusion: lead sulphates, lead phosphites, for pipes Property
Unit
Typical grades Universal (pipes)
1 Appearance
Universal (hi-flow)
Universal (FR)
Universal (black)
white granules
Specific gravity
approx
1.5-1.7
1.4-1.5
1.7
1.3
Metal content
approx
24.8-39.5
27.9-33.0
37.5
24.0
Stabilizer
phr
1.8-2.2
1.8-2.2
1.8-2.2
1.8-2.2
DiNP/DiDP
phr
Filler (chalk)
phr
2.0-6.0
2.0-6.0
2.0-6.0
2.0-6.0
low/med
low
med
med
Formulation: 1 S-PVC=100phr
Lubrication: int. Lubrication: ext. Dosage
phr
med/high
high
med
1.8-2.2
1.8-2.2
1.8-2.2
med
1.8-2.2 1
© 2001 Elsevier Science Ltd |
Stabilizers
Lead-based stabilizers Description: Master compounds for PVC extrusion: lead sulphates, for corrugated pipe, injection moulding, cable sheathing: low-dust coated grade with 15% fatty acid esters Property
Typical grades
Unit Corrug. pipes
Appearance
Injection moulding
Cable compound
Low-dust coated
white granules
Specific gravity
approx
1.5-1.8
1.5-2.2
2.5-3.0
3.3
Metal content
approx
34.8-43.6
34.4-54.6
53.0-66.0
69.7-72.3
Stabilizer
phr
3.0-3.5
4.0-7.5
3.5-5.0
DiNP/DiDP
phr
Filler (chalk)
phr
2.0-6.0
2.0-6.0
2.0-6.0
-
Formulation: S-PVC=100phr 30-60
Lubrication: int.
low/high
med
med
high
Lubrication: ext.
high/low
med
med
low
3.0-4.5
4.0-7.5
3.5-5.0
0.5-5.0
Dosage
phr
© 2001 Elsevier Science Ltd
Datasheets
401
Stabilizers
Lead-based stabilizers Description: Master compounds for PVC extrusion: lead phosphites Property
Typical grades
Unit
Profile grades Appearance
Low-dust coated
white granules
Specific gravity
approx
1.7-2.0
2.8
Metal content
approx
42.8-44.0
69.3
phr
3.5-4.0 2.0-6.0
-
med/high
med
Formulation: S-PVC = 1 0 0 phr Stabilizer DiNP/DiDP
phr
Filler (chalk)
phr
Lubrication: int. Lubrication: ext. Dosage
phr
med/low
med
3.5-4.0
0.5-5.0 © 2001 Elsevier Science Ltd
stabilizers
Cadmium, barium stabilizers Description: Master compounds for PVC extrusion: cadmium/zinc for lead-free pipes, barium/zinc for flexible compounds Property
Unit
Typical grades Cadmium/zinc
Appearance
Barium/zinc
white granules
Specific gravity
approx
1.1
1.1
Metal content
approx
-
-
phr
2.5-3.0
1.5-2.5
2.0-6.0
2.0-6.0
Formulation: S-PVC = 100 phr StabiUzer DiNP/DiDP
phr
Filler (chalk)
phr
Lubrication: int.
med
med
Lubrication: ext.
med
med
2.5-3.0
1.5-2.5
Dosage
phr
© 2001 Elsevier Science Ltd
402
Additives for Plastics Handbook
Stabilizers
Organotins Description: Used with most PVC compounds and ABS/MBS blends; physical and chemical properties depend on groups linked to central tin atom. Can be used at low dosages, give high level of transparency; good compatibility with other PVC additives Property
Unit
Typical grades Butyltin mercaptides
Appearance Specific gravity
g/ml
Gardner colour
Butyltin carboxylates
clear liquid
powder
clear liquid
powder
1.055-1.13
0.60-0.63
1.045-1.34
0.50-0.70
max. 2
-
max. 2-3
-
•
•
-
120-123
-
98-100
Light stability
2-3
3
1
1-2
Transparency
1
1
Melting range
Self-lubricating Organoleptic
°C
1
some
some
1-3
2
1
1
PVC; ABS blends
PVC; ABS blends
PVC
PVC
1
Food packaging Applications
Key:1=very gooc , 2 = good, 3 = satisfactory © 2001 Elsevier Science Ltd |
Data sheets
403
Stabilizers
Organotins Description: Mercaptides give excellent early colour/colour-hold in PVC processing. Octyltins have 1 low toxicity, good migration resistance Property
Typical grades
Unit Butyltin mercaptide/ carboxylates
Octyltin mercaptides
Octyltin carboxylate
clear liquid
clear liquid
clear liquid
1.065-1.15
1.085-1.107
max. 2
max. 2
-
-
->
Light stability
2
3
1
Transparency
1-2
1
1
Appearance Specific gravity
g/ml
Gardner colour Melting range
°C
Self-lubricating 2
Organoleptic Food packaging Applications
PVC; some ABS
2
1
for rigid PVC up to 1.5%
for rigid PVC up to 1.2%
PVC; ABS blends
PVC
Key: 1 = very good, 2 = good, 3 = satisfactory © 2001 Elsevier Science Ltd |
stabilizers
Light stabilizers Description: Property
Unit
Diphenyl acrylates
Benzophenones
Cinnamic esters
powder: light green
white powder/ yellow vise. liq.
yellowish powder
pale colourless liquid
g/ml
1.13
1.05-1.16
1.06-1.34
1.00
573
361-277
326-214
290
°C
273-282
96
48-197
-
l%loss
230
10% loss
270
Appearance
Specific gravity Molecular weight Melting range TGAat20°C/min
Typical grades Nickel quencher
220 260 © 2001 Elsevier Science Ltd
404
Additives for Plastics Handbook
stabilizers
Light stabilizers Description: Property
Unit
Diphenyl acrylates
Benzophenones
Cinnamic esters
powder: light green
white powder/ yellow vise. liq.
yellowish powder
pale colourless liquid
g/ml
1.13
1.05-1.16
1.06-1.34
1.00
573
361-277
326-214
290
°C
273-282
96
48-197
-
Appearance
Specific gravity Molecular weight Melting range TGAat20°C/min
Typical grades Nickel quencher
l%loss
230
220
10% loss
270
260 © 2001 Elsevier Science Ltd |
Stabilizers
Light stabilizers - HALS Description: Hindered amine light stabilizers (HALS) Property
Unit
Typical grades Various formulations powder: colourless/ pale yellowish
powder/ granule colourless/ yellowish
viscous liquid: pale yellow
white powder/ yellowish granule
1.18
1.01
0.99
0.99-1.24
(283)n Mn > 2500
(599)n Mn > 2500
509
5050-502
°C
55-70
100-135
liquid
95-267
l%loss
275
300
225
10% loss
325
375
Appearance
Specific gravity
g/ml
Molecular weight
Melting point TGAat20°C/min
275 © 2001 Elsevier Science Ltd
Datasheets
405
Flame retardants Flame retardants
Aluminium hydroxide Description: Broad range of flame retardants: acting by endothermal decomposition, with release of water vapour and alumina: modified grades for thermosetting resins Chemical analysis (%): AI2O3: 65.0, Na20: 0.30, Si02: 0.01, Fe203: 0.01 1 Property
Unit
Typical grades
Modified grades
Specific gravity
g/cm^
~2.4
~2.4
-2.4
Bulk density
g/cm^
~0.5
~0.7
~ 0.7-0.8
~2.4
Mohs hardness
2.5-3.6
2.5-3.6
2.5-3.6
2.5-3.6
Refractive index
1.57-1.58
1.57-1.58
1.57-1.58
1.57-1.58 8-10
8-10
8-10
8-10
Av particle size dso
pH value |im
2.9
7.2
8.5-16.0
7
Av particle size d97
|im
< 8
< 24
< 24-64
<48
m^/g
> 8
>4
> 3-1
>4-5
Surface area Oil absorption
g/lOOg
Loss on ignition
1100°C
~34.5
~34.5
~34.5
~34.5
%
< 0.6-2.0
< 0.5
< 0.5-0.4
< 0.5-0.3
Moisture content
Notes: Processed in c(impounds at up to 200°C; surface-modified grades for higher processing temperatures © 2001 Elsevier Science Ltd
1
1
406
Additives for Plastics Handbook
Flame retardants
Aluminium trihydroxide Description: White crystalline powders using release of water on heating to give high performance flame retardant and smoke suppressant properties to a wide range of plastics and elastomers: median particle size 5-80 jim; coatings include silanes, stearates, and plasticizers Chemical analysis (%): AI2O3: 65.1, H2O: 34.5, Na20: 0.2, CaO: 0.02, Si02: 0.01, Fe203: 0.006, V2O5: 0.002, Cu: 0.001, Mn: 0.0001 Property
Specific gravity Bulk density
Typical grades
Unit
g/cm^
Mohs hardness Refractive index pH value
Standard milled
Medium milled
Fine milled
Precipitated
2.42
2.42
2.42
2.42
1.2-0.9
0.8-0.7
0.6-0.55
0.9-0.75
2.5-3.5
2.5-3.5
2.5-3.5
2.5-3.5
1.57
1.57
1.57
1.57
9.0-9.5
9.5
9.5-10.5
9.5-10.5
27
21-14.5
9.5-6.5
20-7
Av particle size
max)am
Av particle size
min jim
17
15-9.5
7.5-6.5
Residue on sieve
53 |im
95-20
5-0.1
-
Residue on sieve
45|im
-
-
0.1
Surface area Oil absorption Elect, conductivity
m^/g
0.05-0.5
1.0-1.3
2.9-6.0
1.0-0.1 1 0.5-1.1 1
g/lOOg
15-22
23-26
27-28
21-24
|iS/cm
5
5
10-15
Notes: For thermosetting resins, PVC, elastomers. Precipitated grades have rounder particles and lower surface area, for denser packing, reduced resin adsorption giving lower viscosity: SMC/DMC, other resin/glass processes. © 2001 Elsevier Science Ltd |
Datasheets
407
Flame retardants
Aluminium trihydroxide Description: For glass-reinforced thermosetting resins: modified particle shapes offer choices of higher loadings, better processing (lower viscosity) and physical properties, smoother finish. 1 Superfine grades for thermoplastic and elastomer cable compounds and mouldings Chemical analysis (%): AI2O3: 65.1, H2O: 34.5, Na20: 0.25, CaO: 0.02, Si02: 0.01, Fe203: 0.008, 1 V2O5: 0.002, Cu:0 0 0 1 , Mn: 0.0015 Property
Unit
Typical grades Modified particle
Optimized particle
Modified morph.
Superfine
2.42
2.42
2.42
2.42
Bulk density
0.9-0.7
1.0-0.7
0.75-0.65
0.25-0.2
Mohs hardness
2.5-3.5
2.5-3.5
2.5-3.5
2.5-3.5
Refractive index
1.57
1.57
1.57
1.57
pH value
9.5
9.3-9.7
9.6-9.8
10
21-11
55-12
17-6.0
1.4-0.5
Specific gravity
Av particle size
max|xm
Av particle size
min|im
Residue on sieve
53 )im
Residue on sieve
45 )im
5.0-0.1
65-2.0
3 5-0.1
0.1
Surface area
m^/g
0.5-1.3
1.2-1.7
1.2-1.7
4-11
g/lOOg
21-2 5
16
12-18
|iS/cm
5
Oil absorption Elect, conductivity
36-44 7.0-13*
Notes: *Electrical grades
1 |
© 2001 Elsevier Science Ltd
408
Additives for Plastics Handbook
Flame retardants
Ammonium polyphosphates Description: Dehydrating agent for intumescent coatings/sealants: effective catalytic action and low water solubihty reduce leaching from system Property
Unit
Phosphorus P2O5 Phosphorus (P) Nitrogen
% % %
71
67
72
31
29
31.5
14
15
14
5
6
6
g/100 ml
3.5
2.2
0.3
53 |j.m
2%
2%
0.5%
)im
15
15
15
phase
1
1
2
pH 10% slurry Solubility in water Residue on sieve Av particle size Crystal type
Typical grades
Notes: White free-flowing powders, easily dispersed in polymers: mainly used in intumescent paints: also in sealants, PU foams, epoxy resins, non-halogenated FR PP © 2001 Elsevier Science Ltd |
Flame retardants
Antimony oxide Description: Widely used flame retardant, for use with halogen source. Fine powders, easily dispersed in plastics and paints: granular, damped and paste forms also available, for easier handling. Also available as masterbatch Property
Antimony oxide Arsenic Iron Lead Acidity
Typical grades
Unit
% % % % 0/
/o
Non-pigmented
Standard white
Colour unimportant
Low tint
99.7
99.7
99.1
99.5
0.12
0.15
0.3
0.1
0.002
0.003
0.005
0.2
0.03
0.05
0.3
0.01
0.01
0.01
0.05
Av particle size
|am
1.25
1.25
1.30
10
Residue on sieve
53 |im
0.002%
0.002%
0.005%
0.5%
Notes: Used with suitable chlorinated or brominated compound in non-halogenated plastics: can be used direct in plasticized PVC. Negligible content of 'coarse' particles allows use in thin films and sheet. Low tint grade has 15-18% tint strength of standard grades, for translucent or high colour products, allowing lower pigment addition © 2001 Elsevier Science Ltd
Data sheets
409
Flame retardants
Antimony oxide Description: Lower cost blends, special grades Property
Antimony oxide
Typical grades
Unit Blue
Low-cost grade
Blended
Smoke suppress
99.8
25
60.0
30-50
0.07
0.1
0.1
0.1
0.1
0.1
0.1
0.01%
0.02
0.02%
25
60
50-70
0.002
Acidity
% % % % %
Av particle size
|im
1.25
53 |im
0.002%
Arsenic Iron Lead
Residue on sieve Tint strength
%
0.06 0.01
Notes: Blue used in certain pigments and as flame retardant for low lead and arsenic content. Low-cost grade is cost-effective FR with lower tint strength, esp. for wire and cable and general thermoplastics. Antimony/zinc blend is lower cost, can control afterglow. Blends with magnesium/zinc complex combine FR and smoke suppression for PVC; also reduce use of pigment © 2001 Elsevier Science Ltd |
410
Additives for Plastics Handbook
Flame retardants
Magnesium hydroxide Description: High purity: acts by endothermal decomposition of metal hydroxides with release of water vapour: reaction commences at about 320°C; additive is suitable for high processing temperatures Property
Unit
Typical grades
Polyamide gradex
Chemical analysis (%): MgO - 65; CaC - 2.4, Na20: 0.20, Fe203: 0.35 Loss on ignition
1100°C
~31%
~31%
~31%
Specific gravity
g/cm^
~2.4
~2.4
~2.4
Bulk density Mohs hardness
2.4-2.6
2.4-2.6
2.4-2.6
Refractive index
1.56-1.59
1.56-1.59
1.56-1.59
~94
~88
-94
~10
~10
-10
|im
2.3
16
2.3
|im
< 12
< 64
< 12
m^/g
> 8
~3
> 8
<0.5
<0.5
Whiteness
%
pH value Particle sizeci5() Particle size d9 7 Surface area Oil absorption Moisture content
g/lOOg
%
<0.5 ((]) 2001 Elsevier Science Ltd
Datasheets
411
Flame retardants
Magnesium calcium carbonates Description: Produced by micronization of natural mixed mineral (huntite, hydromagnesite); hydrate is efficient FR for processing temperatures up to 2 60°C, also acid scavenger in chlorine-containing compounds; magnesium calcium carbonate is for processing temperatures up to about 400°C, with improvement to mechanical properties from platelet structure and high aspect ratio Property
Typical grades
Unit Mag/calc/carb/hydrate
Mag/calc/carb
PBT/PP grade
Chemical analysis (%):MgO= 36.5-33.6; CaO= 10.5-14.5, Si02: 0.4-1.5, Fe203: < 0.1 Loss on ignition
llOO^C
~52
-49.5
- 52%
Specific gravity
g/cm^
~2.5
-2.5
-2.5
Bulk density
g/cm^
-0.24
-0.24
-0.24
Mohs hardness
2-3
2-3
2-3
Refractive index
1.56
1.56
1.56
> 93
> 93
> 93
Whiteness
%
-10
-10
-10
|im
0.5
0.4
0.5
l^m
< 5.0
< 5.0
< 5.0
m^/g
> 10
> 12
> 10
<0.5
<0.5
< 0.5
pH value Particle size dso Particle size d9 7 Surface area Oil absorption Moisture content
g/lOOg /o
Notes: PBT/PP grade has special surface treatment © 2001 Elsevier Science Ltd |
412
Additives for Plastics Handbook
Flame retardants
Melamine cyanurate, phosphate Description: Fine white crystalHne powders: melamine cyanurate has two endothermal peaks - at 335°C (decomposition of remaining free melamine) and 412°C (decomposition of melamine 1 cyanurate) Property
Typical grades
Unit
Cyanurate 1 Specific gravity
1.60
1 Molecular weight Nitrogen content Water content
% %
Melting range
°C
pH value Particle size < 25 |xm Bulk density
Phosphate
% g/ml
Solubility:-water
255.2
224.13
48-50
37.5
0.6 none
340*
~8.0
2.2
98 ~0.33
~0.35 0.5
-ethanol
g/lOOg
insoluble
-acetone
solvent
insoluble
at
0.04
30°C
0.03
- dimethylformamide -trichlorethylene
Notes: *Temperature is for reference value only: gradual NH j separation is assumed to occur far below this level © 2001 Elsevier Science Ltd
|
Datasheets
413
Flame retardants
Zinc borates Description: Multi-functional flame retardants and smoke suppressants for wide range of polymers (esp. PVC leathercloth, foil, calendered film, cable); generally used with antimony trioxide. Boric acid content can fuse to form glassy ablative layer, while zinc oxide cross-links PVG chains, reducing smoke; release of crystallized water also cools flame. Good afterglow control, esp. for back-coating of cotton textile, conveyor belting Property
Unit
Typical grades 45.7
37.4
37.4
39.1
48.1
48.1
.Hydration water
% % %
15.2
14.5
14.5
Av particle size
)j.m
4
5
1.5
1.57
1.59
1.59
g/lOOml
0.04
0.10
0.10
°C
200
280
280
380 420
ZnO content B2O3
Refractive index Solubility (water) TGAl%loss 5% loss
°C
245
380
10% loss
°c
285
420
1 1
Notes: Low-smoke cable formulations. Low refractive index allows translucent and deep-coloured formulations, at low cost © 2001 Elsevier Science Ltd |
414
Additives for Plastics Handbook
Antistatics and conductive
additives Conductive additives
Carbon black 1 Description: Conductive grades (furnace process) Property
Unit
High conduct.
Conduct/ antistatic
Conduct/ UV shield
Ultrapure
Nitrogen surface area
m^/g
1475
254
140
130
|xm
15
30
20
20
DBP absorption
ml/lOOg
330
178
116
98
Oil absorption
g/lOOg
Mean particle size
Colour depth
index
67
87
88
88
Tinting strength
index
130
87
104
103
Volatile content
%
2.0
1.5
1.5
1.5
8.6
5.0*
8.5
8.5
pH value Tamped density: -powder -beads
g/1
-
97
192
-
g/1
152
273
332
384
Notes: *Powder: pH = ^^.5 © 2 0 0 1 Elsevier Science Ltd
415
Datasheets
Conductive additives
Quaternary ammonium compounds Description: Control electrostatic discharge at low concentration; minimal effect on processing reactivity; minimal effect on other polymer properties. Available as 100% active products or as fluids in a variety of solvents. Stable in dilute acids, unstable in strong alkalis; compatible with nonionic and cationic surface active agents; incompatible with soaps and anionic surfactants Property
Density
Typical grades
Unit 100% active
n-Butanol solvent
Butane, ethane diol solvent
-
0.930-0.950
0.995-0.998
1.131
yellow waxy solid, brown paste
brown or yellow liquid
pale yellow liquid
white or pale yellow liquid 50
g/cm^
Appearance
TCPP
Activity
%
100
80
80
Pour point
°C
70
4-5
5
8
Flash point PMCC
°c
-
40
> 100
> 100
1
Resistivity: -powder
Qcm
-end-product
^cm
Notes: TCPP (trichloropropyl/phosphate) is often used in polyurethanes at 8-15% as a flame retardant: dosage may be reduced with this additive © 2001 Elsevier Science Ltd |
Conductive additives
Glass fibre, spheres Description: Glass reinforcement in various forms, coated with silver Property
Density
Unit
Particle size distr. Silver content
Coated glass fibre
Coated solid spheres 1.2-1.4
0.9
0.2
cylindrical
spherical
spherical
spherical
5 0 - 7 5 10-15
92-34
124
46 5
60-120/15-50
1-30
g/cm^
Shape Particle size av.
Typical grades
mean )im jim
%
8
Colour L value Powder resistivity
^cm
End-product resistivity
^cm
Coated solid spheres
< 2m
Coated hollow spheres
33 1 75-55
55-60
79
n/a
n/a
1.710-^
© 2001 Elsevier Science Ltd
416
Additives for Plastics Handbook
Conductive additives
Metal particles Description: Granule, flake and other particles of metal, coated with silver Property
Unit
Typical grades Copper granules
Density
g/cm^
Shape Particle size av.
)am
Particle size distr.
|im
Silver content
%
Colour Lvalue
Copper
flakes
Copper needles
2.2
0.6
irregular
flake
needle
45
1.4
<30
171
18
18
65 min
Resistivity: -powder
ficm
-end-product
ficm
0.1m
0.6 10-^
<0.15m
1
(0 2001 Elsevier Science Ltd |
Conductive additives
Miscellaneous particles Description: Aluminium and inorganic (mica) coated with silver, and uncoated aluminium-compatible particles Property
Unit
Typical grades Aluminium particles
Density
g/cm^
1.6 spherical
Shape Particle size av.
|im
Particle size distr.
}im
Silver content
Aluminium-compatible particles
%
Inorganic flakes (mica) 4.8 flake
40
552 5-25
20
18
Colour Lvalue
49 min.
Resistivity: -powder
^cm
-end-product
^cm
0.7 10-^
5 10"^
0.1m <0.15m © 2001 Elsevier Science Ltd
Datasheets
417
Curing, cross-linking agents Cross-linking agents
Organic peroxides
Type
Dialkyl peroxides
Dialkyl peroxides
Dicumyl peroxide
Perketales
powder or granulate on chalk
liquid
powder or granulate on chalk
powder or granulate on chalk
Peroxide/active Oxygen content
%
40-95
98
40-98
40
Storage/transport temperature
°C
2 5 max
30 max
30 max
2 5 max
SADT
°C
~70
~80
~90
~70
no danger/org peroxide solid D 6b
org peroxide liquid E 7b
no danger/org peroxide solid F 10b
org peroxide solid D 6b
PE and rubber atl80°C, dust-free
PEand rubber atl90°C
PE and rubber atl70°C, dust-free, no blooming
PE and rubber at 150°C. dust-free
Dangerous goods classification
Applications/properties
© 2001 Elsevier Science Ltd
418
Additives for Plastics Handbook
Curing agents
Catalysts (peroxides) Ketone peroxides
Type
Methyl ethyl ketone
Acetyl ketone
Cyclohexanone
Mixtures
paste, solution
solution in phthalate
solution
solution
Peroxide/active Oxygen content
%
-/5.45-9.80
-/4.20
-/5.10-9.80
-/5.20-9.00
Storage/transport temperature
°C
25 max
25 max
25 max
2 5 max
Control/emergency temperature/SADT
°C
-/-/~60
-/-/^70
- / - / ~ 50-60 50-60
Applications/ properties
high activity, fast cure
translucent sheet, concrete
resins, buttons, gelcoats
short/long gel, with fast/slow cure
© 2001 Elsevier Science Ltd |
Curing agents
Catalysts (peroxides) Ketone peroxides
Type
Diacyl peroxides
Alkyl hydroperoxides
Dialkyl peroxides
suspension, paste, powder
solution
powder, granule, liquid
Peroxide/active oxygen content
%
20-50/1.32-3.30
40-70/4.20-12.43
40-98/2.35-10.80
Storage/transport temperature
°C
2 5-30 max
25 max
1 5 - 3 0 max
Control/emergency temperature/SADT
°C
- / - / ~ 50-80
-/-/-50-80
- / - / ~ 70-90
unsat. polyesters; easy dispersion
hot cure; room temp, vinyl ester
curing SMC and BMC
Applications/ properties
© 2001 Elsevier Science Ltd
Datasheets
419
Curing agents
Catalysts (peroxides)
Type
Perketales
Alkyl peresters
Peroxy dicarbonates
Peroxycarbonate esters
powder, solution
powder, liquid, solution
powder, suspension
liquid, powder on chalk
Peroxide/active oxygen content
%
40-65/ 4.20-6.18
50-98/ 3.47-8.07
40-95/ 1.12-3.80
50-95/ 3.25-6.81
Storage/transport temperature
°C
15-30 max
0-30 max
15 max
2 5 max
Control/emergency temperature/SADT
°C
20/25/ 40-70
20/25/ 40-60
30/35~45
-/-/50
curing SMC and BMC: good stability
curing SMC and BMC at 80-140°C
hot curing above r = 60°C
curing SMC and BMC: long flow process
Applications/ properties
© 2001 Elsevier Science Ltd |
420
Additives for Plastics Handbook
Property modifiers, processing aids Modiflers/compatibilizers
Ethylene/methyl acrylate copolymer Description: (EMAC) Used as an impact modifier and compatibilizer: good tie-layer in 1 coextrusion, with broad temperature range: translucent/clear colour Property
Unit
Typical grades 2202
Melt index Methyl acrylate Density
2220
2252
0.4
2-6
20
0.6
/o
21
20-24
20
21
g/cm^
0.942
0.942-947
0.942
0.949
g/lOmin
Hardness shore A
90
86-89
88
90
Hardness shore D
38
26-33
29
38
2000 1
Tensile (break)
psi
2000
1270-1620
1100
Elongation (break)
%
680
780-800
780
680
Flexural stiffness
psi
5000
Brittleness temp.
°C
<-76
<-76
<-76
<-76
Melting point
°c
85
53-59
54
-
>360
>360
100
>360
no
no
ESCR(l()%lgepalat5()°C) Slip/anti-block
no
yes 1
© 2001 Elsevier Science Ltd
Data sheets
421
Processing aids
Acrylic copolymers Description: High molecular weight acrylic copolymers, as white free-flowing powders, to improve processability of PVC compounds: lubricant grades reduce adherence to melt to processing equipment Property
Unit
Typical grades PA-10
PA-20(tin)
PA-20(Ca/Zn)
g/cm^
0.548
0.553
0.553
Specific viscosity
SP
0.7
1.0
1.0
Volatile content
%
0.5
0.5
0.5
0.1-25
0.2-30.1
0.2-30.1
90
90
90
s
70/60
67/61
54/47
Nm
27.9/30.1
27.8/31.2
21.3/23.7
Specific gravity
Particle size distr.
495/147
Bubble fish eye Processing properties (dosage: 1/5 phr) Gelation-max -constant torque
%
22.1/25.5
24.8/30.9
42.2/55.0
Roll torque
Die swell 30rpm
Nm
149/168
149/183
44.3/58.8
Heat stability
min
163
160
100
%
11.4
10.1
11.5
Haze
© 2001 Elsevier Science Ltd |
422
Additives for Plastics Handbook
Processing aids
Acrylic copolymers Description: Property
Specific gravity Specific viscosity Volatile content Particle size distr.
Unit
Typical grades PA-30 (tin)
PA-30 (lead)
PA-101 (tin)
PA-101 (Ca/Zn)
g/cm^
0.540
0.540
0.518
0.518
SP
2.7
2.7
0.13
0.13
0.4
0.4
0.5
0.5
0.2-33.2
0.2-33.2
0.2-29.9
0.2-29.9
33
33
14
14
% 495/147
Bubble fish eye Processing properties (dosage: 1/5 phr)
65/47
192/116
84/68
114/83
-constant torque
29.2/35.3
22.1/26.2
27.4/26.6
18.6/18.9
Die swell 30rpm
24.9/34.3
36.0/44.0
26.3/-
36.5/-
157/214
72.8/93.6*
139/134
102/101
Heat stability
160
285
200
122
Haze
12.8
9.3
16.5
Gelation-max
Roll torque
1
Notes: *Profile extrusion : screw torque (Nm) C) 2001 Elsevier Science Ltd |
Datasheets
423
Plasticizers Plasticizers
Monomeric/polymeric Description: Good resistance to extraction and migration: polyesters, based on adipic acid; liquid Property
Acid value Colour
Typical grades
Unit
max
Monomeric
Polymeric med. vise.
Polymeric high vise.
Polymeric highperf.
0.5
3.0
3.0
3.0
Gardner
1
3
7
5
cP
16
3-3500
3 5 - 4 5 000
8-10 000
Hydroxyl value
max
3
35
20
10-20
Relative density
25°C
0.92
1.09
1.08
1.08
°C
142
151
166
150
Dynamic viscosity
SGTT
phr
47
66
69
80
Modulus
kg/cm^
88
87
86
86
Tensile strength
kg/cm^
182
186
180
170
Efficiency cone.
Elongation (break) Hardness Brittle point Volatility (7days)
%
367
376
403
360
Shore A
74
75
74
73
°C
-60
-22
-2 3
-16
-1.1
-0.9
-2.1
105°C
-6.7
1
(0 2001 Elsevier Science Ltd |
424
Additives for Plastics Handbook
Plasticizers
Phthalates Description: DOP is the most widely used plasticizer: other grades are for special purposes, heat-resistant cable, etc. Property
Unit
Typical grades Dioctyl phthalate
Acid value
max
Saponification val. Viscosity
Phthalic acid ester
Diisotridecyl
Dimethyl cyclohexyl
<0.5
<0.5
<1.5
160-235
208-217
305-320
50-70
250-350
15-25 000
Relative density
0.913-953
0.946-954
1.06-1.08
Flashpoint
>220-230
>210
>200
Refractive index
1.477-485
1.482-486
1.447-448
SGTT
°C
118
Efficiency cone.
phr
54
Modulus
kg/cm^
83
Tensile strength
kg/cm^
Elongation (break) Hardness Brittle point Volatility (7days)
186
%
359
Shore A
75
°C
-29
1()5°C
-10.0 © 2001 Elsevier Science Ltd |
Datasheets
42 b
Plasticizers
Epoxy-based Description: Used as stabilizing plasticizers and pigment dispersing agents for PVC: alkyl epoxy stearate for low viscosity and low temperature performance Unit
Property
Acid value
Typical grades Epoxidized soya bean oil
Epoxidized linseed oil
Alkyl epoxy stearate
max
<0.3-0.5
<0.7-1.0
<0.4
mPas
500-600
1000-1500
20-40
6.3-7.0
8.5-9.7
3.5-5.5
0.992-0.999
1.020-1.040
0.900-0.930
Saponification val. Viscosity Epoxy content Relative density
20°C °C
>300
>300
>210-220
20°C
1.472-1.474
1.475-1.479
1.453-1.459
general
limited
limited
Flash point Refractive index Food contact
© 2001 Elsevier Science Ltd
Plasticizers
Ester-based Description: Monocarboxylics used as viscosity depressant for PVC pastes, secondary plasticizer for flexible PVC: stearic acid is a general plasticizer and processing agent for plastics and PS lubricant: polyglycol is PVC paste viscosity depressant Property
Acid value
Typical grades
Unit
max
Saponification val.
Monocarboxylic
Fatty acid
Stearic acid butyl
Fatty acid polyglycol
<0.5
<1.0
<0.5
<0.7
145-150
187-199
170-177
140-150
Viscosity
mPas
12-17
4-9
6.5-7.5
47-49
Relative density
20°C
0.850-0.861
0.850-0.890
0.847-0.853
0.984-0.988
°C
>210
>150-155
>190
>150
20°C
1.447-1.454
Flash point Refractive index Food contact
Europe
1.439-1.442 general
Europe
© 2001 Elsevier Science Ltd
42 6
Additives for Plastics Handbook
Plasticizers
Sebacates, adipates Description: Good low-temperature plasticizers for PVC Property
Acid value
Typical grades
Unit Dioctyl sebacate
Dibutyl sebacate
Diisodecyl adipate
Dioctyl adipate
<0.2
<0.2
<0.2
<0.1
max
255-273
350-36-
261-270
295-310
Viscosity
mPas
19-23
8-10
25-30
13-15
Relative density
20°C
0.912-0.916
0.933-0.937
0.913-0.919
0.925-0.926
Saponification val.
Flash point Refractive index
°C
>200
>180
>215
>210
20°C
1.449-1.452
1.441-1.444
1.452-1.454
1.447-1.448
general
general
limited
general
Food contact
© 2001 Elsevier Science Ltd
Plasticizers
Monomeric plasticizers Description: Relatively high molecular weight organic esters, derived from phthalic anhydride, trimellite anhydride or adipic acid with mono-functional alcohols; highly compatible with PVC, with good gelling power, high boiling point/low volatility Typical grades Di-2-ethyl hexyl phthalate
Di-2-ethyl hexyl adipate
Trimellitates
390.56
3 70.6
546.0
mgKOH/g
2872
304 2
305 3
Boiling point
°C
327
208-218
~282
Melting point
°C 1.486-1.487
0.925-0.927
0.985-0.992
Molecular weight Saponification no.
Density
Notes: Adipates are used in mixtures with other plasticizers to modify properties; trimellitates are special plasticizers with less volatility, lower migration (0 2001 Elsevier Science Ltd
Datasheets
427
Plasticizers
Monomeric plasticizers (phthalates) Description: Relatively high molecular weight organic esters, derived from phthalic anhydride, trimellite anhydride or adipic acid with mono-functional alcohols; highly compatible with PVC, with good gelling power, high boiling point/low volatility Typical grades
Molecular weight
Dibutyl, di-isobutyl phthalates
Di-n-heptyl phthalate
Di-iso nonyl/, di-iso decyl phthalates
Di-n-octyl phthalate
278.34
362
418.6,446.7
390
Saponification no.
mgKOH/g
403 3
309 2
2692,2512
2873
Boiling point
°C
327-340
370
413,248
220
Melting point
°C 1.040-1.049
0.991-0.993
0.985-0.987, 0.968-971
0.979-0.981
Density
Notes: Phthalic plasticizers are most often used with PVC © 2 0 0 1 Elsevier Science Ltd |
428
Additives for Plastics Handbook
Blowing agents, dispersants, miscellaneous additives Blowing agents
Azodicarbondiamide Description: Chemical blowing agents for cellular plastics, in powder form, active over processing 1 temperature 140-210°C Typical grades
Physical form Odour
EVA
PVCLDPEEVA
Wide range PVC
pale yellow
pale yellow
orange none
none 116
116
116
Moisture content
Molecular weight
%
0.5
0.5
0.5
Decomposition temp.
°C
125
193
190-200
N2/CO
N2/CO
N2/CO
Gas composition Gas/gram pH (5% suspension)
225 25°C
7.5-8.0
7.0
Mesh size (%)
w/w max
1
0.5
0.1
Ash content (%)
w/w max
0.5
0.5
1
4.5-22
1
Av particle diameter Solubility -insoluble in: -soluble in:
|im
water
water/benzene DMF, DMSO
© 2001 Elsevier Science Ltd |
Datasheets
429
Blowing agents
Other chemicals Description: A = p-toluene sulfonyl semicarbazide: general injection moulding; B = 2,2'-azobisisobutyronitrile: low-temperature blowing agent for rigid PVC; 1 C = 4,4'-oxybis(benzene sulfonyl hydrazide): PVC, LDPE/EVA foams Typical grades A Physical form
B
C
white
white
off-white
Odour
none
none
none
Molecular weight
229
164
358 0.5
Moisture content
%
0.5
0.2
Decomposition temp.
°C
200-240
45-90
151-60
N2/CO
N2
N2/steam
7.0
, 6.5 •
Gas composition Gas/gram
135
pH (5% suspension)
25°C
Mesh size (%)
w/w max
Ash content (%)
w/w max
1
Av particle diameter
l^m
4-6
Insoluble in:
Soluble in:
7.0
120 0.2
0.5
water acetone toluene
water
water benzene
DMSO
aliphatic hydrocarbons
DMF DMSO
1
(0 2001 Elsevier Science Ltd |
430
Additives for Plastics Handbook
Lubricants, release agents, slip/anti-block Anti-blocking agents
Magnesium silicate hydrate Description: Chemical analysis: Si02 62; AI2O3 0.3; MgO 31.2; FeOs 0.1 % Property 1 Specific gravity Hardness
Unit
Typical grades
g/cm^
~2.77
Mohs
1
m^/g
>5
Refractive index pH value Specific surface Particle size
?m
Particle size distr.
|im
d5()3,d97<9
iKxrc % %
~5.5%
Oil absorption Loose bulk density Loss on ignition Whiteness ISO Moisture
~96 <0.5
1 1
© 2001 Elsevier Science Ltd |
Datasheets
431
Nucleating agents
Magnesium silicate hydrate 1 Description: Very fine particles optimize nucleating activity in PE and PP Chemical analysis: Si02 62; AI2O3 0.3; MgO 31.2; FeOs 0.1% 1 Property
Unit
Typical grades
Specific gravity
g/cm^
~2.77
Hardness
Mohs
1
m^/g
>22
Refractive index pH value Specific surface Particle size
|im
Particle size distr.
)im
d5()0.9,d97 < 5
Loss on ignition
1100°C
~6%
Whiteness ISO
% %
~97
Oil absorption Loose bulk density
Moisture
<1 © 2001 Elsevier Science Ltd |
432
Additives for Plastics Handbook
Lubricants
Mould release agents (internal) Description: Alcohol phosphates, mixtures of fatty alcohols, acids and derivatives with microcrystalline waxes, amides and organic acid derivatives and mixtures of synthetic resins: liquid or powder, added to thermoplastics or thermoset compound to migrate to surface and prevent adhesion to a mould Property
Physical state Colour Solids Active content Viscosity (2 5°C) Density
% %
Applications
Fatty alcohol/ acid with wax
Fatty alcohol/ acidderiv.
Amides/ organic acid deriv.
clear liquid
solid pellets
liquid
powder
colourless
beige
amber
white
100
100
100 100
cP
280 0.99
150 0.87
0.95
0.54
non-flam
non-flam
non-flam
1.8-2.0
Flashpoint
Shelflife
Alcohol phosphates
g/ml
pH( 15% in water)
Melt/solidification point
Typical grades
Unit
non-flam °C
|
70-140
87 one year
one year
one year
one year
UP
Rubbers
TP,SR
TP*
Notes: *Especially good for styrene polymers Q 2001 Elsevier Science Ltd
1
Datasheets
433
Lubricants
Mould release agents (internal) Description: Alcohol phosphates, mixtures of fatty alcohols, acids and derivatives with microcrystalline waxes, amides and organic acid derivatives and mixtures of synthetic resins: liquid or powder, added to thermoplastics or thermoset compound to migrate to surface and prevent adhesion to a mould Property
Physical state 1 Colour Solids Active content Density
Typical grades
Unit Secondary amide
Synthetic resin/ glyceride/acid
Ethylene bis-stearamide
Ethylene bis-oleamide
micropearl
powder
powder*
powder
ivory
yellow/wh
cream
cream
100
100
% %
>99
g/ml
0.77
98 0.54
Acid value (max) Colour (max)
Gardner
1 Amine value Moisture (max)
%
Melting point
°C
70
Flashpoint
0.99
0.99
5-10
5-10
5
10
5
5
0.5
0.5
70-140
140-145
115-120
non-flam
~300
300
universal slip agent anti-block
slip agent anti-block
Shelf life
one year
one year
Applications
TP, PVC
roto-moulding
FDA status
indirect food contact
Notes: *Also beads, prilled, atomized, aqueous dispersion © 2001 Elsevier Science Ltd |
434
Additives for Plastics Handbook
Lubricants
Mould release agents (internal) Description: Used also as slip agents, anti-blocking, dispersants Property
Physical state Colour Solids Active content Density
Stearamide ethyl alcohol
Fatty acid amide ester
Polycarboxylic acid amide
Dioleoylethylenediamide
powder
powder
powder
beads
cream
cream
white
tan
0.99
0.97
0.99
% % g/ml
Acid value (max) Colour (max)
Typical grades
Unit
< 10 mg
<3 Gardner
Amine value Moisture (max)
%
Melting point
°C
Flashpoint
75-78
78-82
~300
~300
slip agent anti-block
universal
186-210
110-117 271
Shelflife Applications
engineering plastics
printable PVC*
Notes: Stearamide is particularly compatible in polyester film manufacture: amide ester acts also as dispersant: polycarbonylic for high-temperature processing. *internal or external; also release agent for thermoplastic urethanes © 2001 Elsevier Science Ltd |
Datasheets
435
Lubricants
Mould release agents (external) Description: Fluoropolymers and high molecular weight polymers in solvent or water emulsion: applied direct to mould, forming film to prevent adhesion of plastic compound Property
Typical grades
Unit Fluorocarbon insolvent
Fluoropolymer in water
PE waxes insolvent
Fatty acids in water
Physical state
liquid
Colour
white
liquid
liquid
liquid
white
yellow/white
white
% %
4.9
11.5
6.1
1.5
cps
55
8
g/ml
0.85
1.0
0.95
1.0
Flash point
°C
10
non-flam
30
non-flam
Melt/solidification point
°C one year
6 months
6 months
6 months
TS.TP
FRP. TP
TS resins
BMC SMC
Solids Active content Viscosity (2 5°C) Density
5
pH( 15% in water)
Shelf life Applications
3.75
Notes: Non-flammable versions are usually available © 2 0 0 1 Elsevier Science Ltd |
436
Additives for Plastics Handbook
Lubricants
Mould release agents (external)
Description: Fluoropolymers and high molecular weight polymers in solvent or water emulsion: applied direct to mould, forming film to prevent adhesion of plastic compound Property
Typical grades
Unit Highmol. wt fluoropolymer
Highmol. wt resins
High mol. wt resins
Resins in water/alcohol
Physical state
liquid
liquid
liquid
liquid
Colour
transp.
yellow
amber
yellow
4.3
9
6
3.9
8
2500
1.0
0.95
0.706
0.87
36
<21
31
Solids Active content
% %
Viscosity (2 5°C)
cP
Density
g/ml
pH( 15% in water)
55
neutral
Flash point
°C
non-flam
Melt/solidification point
°C
stable to 2 5(rC
Shelf life
6 months
6 months
one year
one year
Applications
TS resins rubber
PUR foam,
TP, PVC, epoxy
PU foam, TS resins
elastomer (1^2001 Els evier Science Ltd
Datasheets
4:3 7
Lubricants and plasticizers
Adipates Description: Dioctyl adipate: low-viscosity water-white plasticizer with high efficiency, good processing, outstanding low-temperature performance; may also be blended with DOP for low-temperature flexibility and good electrical, weathering, heat, UV and 'feel' properties: PVC-coated fabrics for automobile, upholstery and clothing, wire insulation, garden hose, low temperature PVC packaging films Property
Unit
Typical grades Dioctyl
Acid value Colour
MgKOH/g
0.03
Hazen
5
Saponification val.
MgKOH/g
303
Hydroxyl value
MgKOH/g
0.07
Solubility in mineral oil Melting point Viscosity at 2 7°C Density at 2 7°C
miscible all propns
|
°C cP
11.5-11.8
g/ml
0.93-0.95
Freezing point
°C
Pour point
°C
-70 (c) 2001 Elsevier Science Ltd |
438
Additives for Plastics Handbook
Lubricants and plasticizers
Fatty acid esters 1 Description: Fatty acid esters of polyol, fatty alcohol Property
Unit
Typical grades Esters (liquid)
Esters (solid)
Alcohol
Liquid/solid
liquid
solid
solid
Acid value
below 1
below 5
below 0.2
Iodine value
70-120
70-120/below 10
below 1
°C
-
84-90
48-54
Freezing point
°C
-10
-
-
Flashpoint
°c
Melting point
Viscosity at 30°C
est
35-610
~24
4 - 6 (80°)
Density at 3 0°C
g/ml
0.905-0.985
0.895*
0.790-0.802**
Refractive index
20-30°C
1.460-1.478
-
1.427-1.430
internal
internal
internal
clear
clear
clear
Function Transparency
|
Dosage: uPVC -plasticizedPVC Notes: *Density at 10 0°C: **density at 80°C. Generally approved (in Europe) for food-contact applications: separat e approval for (Irinking water may be required in Germany, Italy, and Holland © 2 0 0 1 Elsevier Science Ltd |
Datasheets
439
Anti-blocking agents
Fatty acid amides Description: Fatty acid amides (primary), manufactured from natural oils and fats: used as slip and anti-block agents by migration to the surface: good oxidative stability, low volatility (data is for refined grades) Unit
Property
Typical grades
Liquid/solid
Stearamide
Oleamide
Erucamide
bead or powder
bead or powder
bead or powder
max
Acid value Iodine value
5.0
1.0
1.0
2 max
87-95
75-82
96-102
70-73
75-82
Melting point
°C
Colour (max)
Gardner
5
2
2
Amide purity
97.0
98.0
98.0
0.2
0.2
0.2
Moisture-bead
% % %
0.5
0.4
0.4
Flashpoint
°C
214
208
229
Moisture - powder
Notes: Erucamide is an excellent release agent and can also aid post-moulding assembly. Evaluate addition level at 1% © 2001 Elsevier Science Ltd
Lubricants
Fatty acid amides Description: Fatty acid amides (secondary) and bis-amides, manufactured from natural oils and fats: high thermal stability - recommended as lubricants for plastics with processing temperatures about 300°C. Bis-amides aid flow, release, anti-caking in styrenics and ABS Property
Typical grades
Unit Oleyl palmitamide
Stearyl erucamide
Ethylene bis-stearamide
Ethylene bis-oleamide
max
2.0
2.0
5.0
5.0
Melting point
°C
60-66
70-75
140-145
115-120
Colour (max)
Gardner
3
3
5
10
Amine value
max
2
2
5
5
0.5
0.5
0.5
0.5
Liquid/solid Acid value Iodine value
Moisture (max)
%
© 2 0 0 1 Elsevier Science Ltd
440
Additives for Plastics Handbook
Lubricants, anti-blocking
Palmitates Description: Cetyl palmitate: heavy, rich, non-greasy; used in place of natural wax: lubricant for engineering plastics. Octyl palmitate, iso-octyl palmitate: clear oily liquid, virtually insoluble in water but readily soluble in vegetable and mineral oils: plasticizer for PVC with anti-blocking properties and additional heat stability; viscosity modifier for plastisols Property
Typical grades
Unit Cetyl
Octyl
Iso-octyl
MgKOH/g
1.0
0.05
0.05
Hazen
5
Saponification val.
MgKOH/g
116
152
152
Hydroxyl value
MgKOH/g
1.0
0.07
0.07
miscible all propns
miscible all propns
miscible all propns
Acid value Colour
Solubility in mineral oil Melting point Viscosity at 2 7°C Density at 2 7°C Freezing point
°C
5
5
54
est
14-15
14.1-14.9
g/ml
0.80-0.81
0.80-0.81
°C
7-8
7-8
(r) 2001 Elsevier Science Ltd
Datasheets
441
Lubricants
Paraffins, waxes Property
Unit
Typical grades Paraffin
Wax esters
Liquid/solid
solid
solid &liq
Acid value
below 0.1-below 0.5
below 1-below 2
below 1-below 2
below 1-below 2
°C
-
46-77
Freezing point
°C
-
below 7
Flash point
''C
210-280
2 1 0 - 2 50
Iodine value Melting point
est
4-6(100")
5-10*
Density at 30°C
g/ml
-
0.816-0.863*
Refractive index
20-30°C
-
1.43-1.45*
Viscosity at 3 ( r c
Function
external
int/extern
Transparency
opaque
clear/cloudy
Dosage: uPVC
0.1-0.6
0.5-1.5
-
0.5-1.5**
-plasticized PVC
Notes: *At 8()°C; **liquid grade. Generally approved (in Europe) for food-contact applications: separate approval for drinking water may be required in Germany and Holland ((') 2001 ElsevierScienceLtd
1
442
Additives for Plastics Handbook
Plasticizers
Sebacates Description: Dibutyl sebacate: highly efficient primary plasticizer for low-temperature applications: used in films and containers for food packaging. Dioctyl sebacate: low viscosity plasticizer with excellent low-temperature performance and good drape characteristics: widely used for PVC compounds involving low temperature use: also upholstery fabric, outdoor wear, electrical insulation and strippable coatings Property
Acid value
Typical grades
Unit
Mg KOH/g
Dibutyl
Dioctyl
0.03
0.02
Hazen
5
5
Saponification val.
Mg KOH/g
357
263
Hydroxyl value
Mg KOH/g
0.07
0.07
miscible all propns
miscible all propns
Colour
SolubiUty in mineral oil Melting point Viscosity at 2 7°C Density at 2 7°C Freezing point
°C cP
9.10-9.30
34.5-34.7
g/ml
0.93-0.94
0.932
°C
-11
-44 ((•) 2001 Elsevier Science Ltd
Data sheets
443
Lubricants and plasticizers
Stearates Description: Cetyl stearate: heavy, rich, non-greasy; used in place of natural wax: lubricant for engineering plastics. Iso-cetyl stearate, iso-stearyl stearate: comparable with natural waxes but low freezing point makes them liquid at low temperatures: viscosity stabilizers for PVC and plastisols; lubricant/flow promoters for PS and ABS, pigment dispersion aids Property
Typical grades
Unit Cetyl
Iso-cetyl
Iso-stearyl
MgKOH/g
1.0
1.0
1.0
Hazen
5
5
5
Saponification val.
MgKOH/g
110
110
110
Hydroxyl value
MgKOH/g
1.0
1.0
1.0
miscible all propns
miscible all propns
miscible all propns
0.84-0.86
0.84-0.86
-5
-5
Acid value Colour
Solubility in mineral oil Melting point Viscosity at 2 7°C Density at 2 7°C
°C
54
cps g/ml
Freezing point
°C
Pour point
°C
C) 2001 Elsevier Science Ltd |
444
Additives for Plastics Handbook
Lubricants and plasticizers
Stearates Description: Butyl stearate, iso-butyl stearate, iso-octyl stearate; oily colourless liquids, insoluble in water, readily soluble in vegetable and mineral oils, acetone and ether: lubricant/flow promoters for PS and ABS, pigment dispersion aids: octyl (2-ethyl hexyl) stearate is also a viscosity stabilizer for PVC and plastisols Property
Unit
Typical grades Butyl
Iso-butyl
Iso-octyl
Octyl
Mg KOH/g
0.07
0.07
0.03
0.03
Hazen
5
5
5
5
Saponification val.
Mg KOH/g
172
172
147
147
Hydroxyl value
Mg KOH/g
Acid value Colour
Solubility in mineral oil Melting point
0.07
0.07
0.07
0.07
miscible all propns
miscible all propns
miscible all propns
miscible all propns
°C
Viscosity at 2 7°C
cP
8.60-8.90
8.60-8.80
13.4-13.7
13.2-13.6
Density at 2 7°C
g/ml
0.875
0.875
0.86-0.88
0.86-0.88
26
26
10
10
Freezing point
°C
Pour point
°C
((') 2001 Elsevier Science Ltd
EDITORIAL INDEX A A-glass 43 abrasion and wear 2 3 , 4 3 , 7 8 , 2 0 0 , 217; see also anti-blocking; slip agents ABS alloying agents 204 anti-static/conductive additives 1 4 2 , 1 4 4 , 1 4 8 , 149-50 blowing agents 179, 180, 187 compounding equipment 2 50, 255 heat stabilizers 94, 95, 96, 97, 103 impact modifiers 1 9 2 , 1 9 5 lubricants 2 0 5 , 2 0 8 pigments 70, 71, 91 recycling 1 3 7 , 2 3 9 , 2 4 3 UV stabilizers 1 0 7 , 1 1 0 , 1 1 2 world production and consumption 14 ABS-based impact modifiers 190, 191 accelerators 3, 1 5 2 - 4 , 1 5 7 , 158, 232 Accurel95CM209 22 7 acetate fibres 39 acetone sensitivity test 293 acetylacetone 160 acetylene black process 84, 86, 89 acid esters 143 Acifresh 221
Aclyn 66 acoustic insulation 3 , 1 9 , 2 2 7-8 acrylic impact modifiers 190, 191-2 acrylic lubricants 2 0 8 - 1 0 acrylic processing aids 199, 200, 208-10 acrylics anti-static additives 1 4 3 , 1 5 0 cure enhancers 162 fluorescent pigments 64 heat stabilizers 96, 103 laser identification 244 and luminescence 64 UV stabilizers 109 acrylonitriles 1 0 7 , 2 0 5 Acrylperl 226 ACTIS (Amorphous Carbon Treatment on Internal Surface) 224 activated charcoal 183 activators 1 5 2 , 2 6 1 adhesion 2 3 , 1 6 7 , 1 6 8 , 1 9 5 , 233 adhesives 1 0 3 , 1 3 5 , 1 6 1 , 1 6 2 adipates 1 7 0 , 1 7 2 , 2 75 Advanced Ceramics Corp. 213 Advanced Compounder 251 Affinity 8 3 , 2 1 7 afterglow 1 3 1 , 1 3 3 AGR 242 agricultural applications 6 4 , 6 5 , 110,111,113 Air Products 160, 181, 228, 229 Akcros 1 0 4 , 1 0 6 , 2 2 0 , 2 3 8
446
Additives for Plastics Handbook
Akzo 1 8 , 4 1 Akzo Nobel 5 6 , 1 0 4 , 1 5 0 Albemarle 18 Alcan 119 algicides 220 aliphatic curing agents 158, 160, 161,261 aliphatic poly amines 158 alkane blowing gases 178-9 alkyl ammonium salts 143 alkyl sulphonic salts 143 AlliedSignal 6 6 , 1 8 4 , 2 1 1 alloying agents 204 AlphaGary 16 alumina 2, 75 aluminium 2 , 1 0 5 , 167 aluminium fibres 4 0 , 1 0 5 , 1 4 6 aluminium hydrotalcites 114 aluminium pigments 58,63 aluminium silicates 80 aluminium trihydrate (ATH) coating for fillers 31,35 as filler 2 0 , 3 5 as flame retardant 116,117, 1 1 8 - 1 9 , 1 2 0 , 1 3 1 , 133-4, 200 aluminosilicate for gas permeability reduction 222 Alusuisse Martinswerk 119 Amcamide 2424 160 Amical 220 amide wax lubricants 208 amidoamine curing agents 15 8-9, 161 amine accelerators and curing agents 153, 154, 1 6 1 , 2 3 2 , 2 6 1 amine anti-static additives 143 amine oxide stabilizers 105; see also hindered amine amine surface treatment of titanium dioxide 75,76 amine-ether 110 amino titanium oxalate 8 3 aminosilane coupling agent 2 5 ammonium polyphosphate flame retardant 128
ammonium salts, as blowing agents 179 Amoco 56 Amorphous Carbon Treatment on Internal Surface (ACTIS) 224 Ampacet 15, 18, 60, 65, 70, 83, 217,227 anatase 7 3 , 7 4 , 7 6 , 7 8 , 8 1 anhydride curing agents 159, 161, 261 Anquamine 401 curing agent 160 anthraquinone-based pigments 6 7 anti-allergy agent 221 anti-bacterials 2 1 9 - 2 1 anti-blocking agents 3,67, 150, 208,211,215,216-18 anti-caking 208 anti-corrosion anti-statics 143 and glass fibre 4 5 , 4 6 and pigments 79 stabilizers 114 anti-degradants 232 anti-fogging additives 2 2 6 - 7 anti-microbials 1 , 3 , 2 1 9 - 2 1 anti-mildew agent 220 anti-static/conductive additives 3, 9,32,42,67,141-50,216 antimony 58, 1 3 5 - 6 , 2 74 antimony oxide 35, 121, 132, 133, 134,135-6,259 antimony sulphide (Anzon) 8 9 - 9 0 antimony trioxide 116, 118, 120, 132,259,292 antioxidants 3, 9 3 - 1 0 6 , 163, 238 for food contact use 2 75 health and safety 258 legislation 2 72 and UV light 108 and UV stabilizers 1 1 2 - 1 3 Anzon 8 9 - 9 0 , 1 3 3 Apache Products 185 Appryl Composites 5 2 APV 251 aramid 3 , 3 9 , 4 0 - 1 , 5 1
Editorial Index
argon 178 Argus Chemical 220 aromatic coupling agents 167 aromatic oils 84 arsenic 2 1 9 - 2 0 , 2 7 4 asbestos 4 9 , 2 6 6 Asoma Instruments 242 ATH see aluminium trihydrite Atochem {now AtoFina) 5 2 automotive industry legislation 2 7 0 , 2 79 Autosort 242 autoxidation 93 AW Compounder 200 Axel Plastics Research Laboratories 214 azo compounds 179, 2 4 1 , 275
B Bairocade range 223 ball clays 26 Barcol hardness test 2 9 2 - 3 barium 20, 8 0 , 9 4 , 9 8 , 1 0 5 , 1 0 6 , 2 7 4 Barlocher 105 barrier property improvement 3, 222-5 barytes 1 9 , 8 0 , 8 1 , 2 2 7 BASF 6 4 , 6 9 , 7 0 , 1 1 1 , 1 2 8 , 2 4 2 , 264,275 Bayer 15, 32, 67, 69, 70, 92, 128, 186,222,244 Bayplast Gran pigments 70 BDMA (benzyldimethylamide) 159 beer bottles 2 2 3 - 4 Bekaert 1 4 5 , 1 4 6 Beki-Shield 145 BekinitKK 146 Bennet 2 0 4 , 2 3 9 bentoniteclay 2, 33 benzoate plasticizers 172, 175 benzoine ether for UV curing 160 benzophenone UV absorbers 109, 110,112 benzotriazole UV absorbers 109, 112
447
benzoxazolone derivative heat stabilizers 100 benzyldimethylamide (BDMA) 159 BI Chemicals 187 BICC General Compounds 163 Binder 242 Bio-Tek Kontron Instruments 293 biocides 2 1 9 - 2 1 biostatic effect 105 bismuth vanadate 6 2 , 7 0 bis(tribromophenoxy)ethane 132, 134 Black Fibre 91 Black Pearls 91 black pigments 3 , 6 9 , 8 4 - 9 2 , 9 3 , 114 Black Silk 91 Black Tek 91 blackness 89 blancfixe 80 Blendex 1 9 0 , 1 9 9 , 2 3 9 blowing agents 3, 1 7 7 - 8 7 , 2 4 1 , 269 blue pigments and dyes 6 8 , 2 9 3 Blue Wool Reference 293 BMC (bulk moulding compounds) 38, 5 1 , 1 5 7 , 191, 222 Boedeker Plastics 16 borate flame retardants 117, 118, 124-5 Borax 124 boron fibres 2 0 , 3 9 , 4 9 boron nitride lubricant 213 boron trifluoride monoethylamine 159 boron-based flame retardants 140 Brabender Technologic 248 BRC 200 compatibilizer 239 brittleness 1 8 9 , 2 2 0 Brockhues 91 brominated flame retardants 9, 117,118,120,122-3,132,134, 137,140,263,271 brown pigments 6 9 BS7211129,163
448
Additives for Plastics Handbook
Biihler 242 bulk moulding compounds see BMC Buss Compounding Systems 249 butadiene 190, 191, 198, 200; see also polybutadiene butanol 183 butyl ethyl propane diol chemistry 96 butyl tin carboxylates 9 8 butyl tin mercaptides 9 8 di-t-butylhydroxybenzoate 105
C-glass 44 Cabalec range 149 cable see wire and cable Cabot 18, 60, 71, 83, 9 1 , 114, 199 cadmium 7, 58, 266, 274, 279 in heat stabilizers 9 4 , 9 7 - 8 , 106 in pigments 61-2, 266, 2 70 cadmium/zinc stabilizers 8,94, 267,272 calcites 2 5-6 calcium alumino-borosilicate glass fibre 4 3 - 4 calcium carbonate 2 , 6 - 7 fillers 3 , 6 - 7 , 2 0 , 2 4 - 6 modifiers 1 9 1 , 1 9 6 - 7 processing aids 199 shrinkage modifiers 222 for U V screening 108 calcium metasilicate filler 197 calcium oxide dessicants 2 3 9-40 calcium silicate 2 , 8 0 - 1 calcium stearite 25 calcium sulphate filler 2 0 calcium/zinc stabilizers 9 7 , 9 8 , 104,105,106,238,266-7 calendering 105,248 carbon 3 , 9 2 , 2 2 4 carbon blacks 3, 9, 14, 20, 61, 66, 84-2,232,233,234 as anti-static/conductive additives 1 4 4 - 8 , 1 4 9 , 1 5 0 grades 84
health and safety 2 5 7-8 masterbatches 9 0 , 9 1 , 9 2 particle size and structure 8 6 - 7 production processes 8 4 - 6 , 8 9 properties 8 5 , 8 6 - 9 , 1 0 8 , 1 4 4 testing 87-9 trends 92 carbon dioxide blowing agents 1 7 8 , 1 8 7 carbonfibres 20, 39, 40, 4 1 - 3 , 51, 55-6 grades 4 0 , 4 1 carbon fillers 197 carbon foam flame retardant 128 carbon tubes, nano-scale 32, 34-5 carbon/PEEK tapes 51 carborundum 2 carboxylic acids 143,2 75 cashew nut oil flexibilizer 198 catalysts 3 , 1 5 2 , 1 5 9 , 1 6 1 , 1 6 2 , 194,261,261,262 CD-R manufacture 65 Ceca 226 cellulose 19, 30,41 CENELAC 129 Cenospheres 29 centrifugal casting 157 Cerdec 6 7 , 6 9 cetyl thimethyl ammonium bromide (CTAB) 8 8 - 9 CFCs 1 7 8 , 1 8 2 , 1 8 6 replacement 3, 101, 140, 152, 182-3,269 chalk 24 chalking 74 Chameleon 65 channel black process 86 Chartwell adhesion promoters 167 chemical vapour deposition (CVD) 225 Chemson 1 0 4 , 2 4 0 Chimassorb 111 china clays 2 5,26 Chlorez 121 chlorfluoralkane 179
Editorial Index
chloride process, titanium dioxide manufacture 74 chlorinated paraffins 1 1 8 , 1 7 3 , 259 chlorine-based flame retardants 1 1 7 , 1 1 8 , 1 2 0 , 1 2 1 , 132,133,140 chloroprene, cross-linking 153 chopped products 4 7-8 chorinated paraffin flame retardants 118, 134 Chrokisti 10 chrome titanate yellows 67,69 chromium 58,2 74,2 79 chromophotal DPP 70-1 Ciba 6 2 , 6 7 , 7 0 , 9 6 , 1 0 1 , 1 0 2 , 111,150 CibaGeigy 238 Ciba Specialty Chemicals 15, 17, 71 Ciba/Witco 18 CKWitco 103 Clariant 1 5 , 1 7 , 6 2 , 6 3 , 1 1 3 , 1 2 6 , 226 clarifying agents 10,199, 200-2 clay, and oxygen permeation reduction 222 clay particle flame retardants 138-9 clays 7 , 2 5 , 2 6 , 3 2 , 2 2 2 5 '*clean room" applications 145 cleaning compounds 204, 229 CMR Technology 65 co-stabilizers 114 coal tar 84 coating offiUers 31 of titanium dioxide 74 coatings 1 , 4 8 , 7 1 , 8 3 , 2 2 5 curing 161, 162 pigments for 71,83 cobalt 5 8 , 1 5 3 , 1 5 4 , 1 5 5 Colcolor range 91 Colloids 62 Color View 293 Color-Chem International 70
449
colorants see pigments and colorants ColorEyeXTH 294 ColorMatrix Europe 112 Colortech 111 Colortronic 6 0 , 2 4 8 colour dosing equipment 245, 252-3 colour testing 2 9 3 - 4 colour-changing pigments 6 4 - 5 colour-identifying systems 242 colours, liquid 3, 7, 5 9 - 6 0 , 252-3 Columbian 15,17, 18 CombiBatch 67 combustibility tests 2 8 9 - 9 0 commingling 51 compatibilizers 3, 48, 54, 167-8, 191,194,195,199,239 trends 1 0 , 1 1 , 2 7 8 compounding equipment 2 4 5 - 5 1 compounding industry 1 6 , 5 7 , 245-6 condensation prevention 22 7 conductive additives 3 , 9 , 2 1 , 1 4 1 50 conductivity, inherent 147-8 conductivity testing 283 ConOuest 148 Continental PET Technologies 223 continuous vulcanization (CV) tube 1 6 2 , 1 6 4 copper 2, 58 core-shell particles 1 9 1 , 1 9 9 , 204, 213 core-shell rubbers 2 0 3 - 4 cotton 3 9 , 1 4 7 , 1 9 7 coupling agents 3 , 2 5 , 2 7 , 1 2 1 , 167-8,191,234 coupling reactions 7,196 CPEE (copolymer/ester elastomers) 1 9 6 - 7 CRD mixer 251 Croda 1 4 9 , 2 1 8 cross-linking 3, 11, 151, 152, 153 of epoxy resins 1 5 9 - 6 0 PE/PVC 240
450
Additives for Plastics Handbook
of rubbers 232 of thermoplastics 162-4 Croxton and Garry 240 Cryovac Sealed Air Corp. 225 CTAB (cetyl trimethyl ammonium bromide) 88-9 CTBN (carboxyl-terminated butadiene acrylonitrile rubbers) 198 curing 3 , 1 5 1 accelerators 1 5 2 - 4 , 2 3 2 agents 3 , 1 5 1 , 1 5 2 - 6 1 , 1 9 8 commercial trends 164 enhancers 162 health and safety 261 initiators 152, 153,160 low-profile additives 222 promoters 160 of rubber 232 tests 2 9 2 - 3 of thermoplastics cable 162-4 Curver 2 39 Cyasorb 1 1 0 , 1 1 4 Cycloflex 185 Cyclomix 248 cyclopentane 184, 186 Cytec 1 0 5 , 1 1 0 , 1 1 4 D D-glass 44 DabcoDC2583A 229 DaiwoboCo 147 Daniel Products 217 DAP (diallyl phthalate) 172 database on chemical legislation 294 Davis-Standard 2 5 2 , 2 5 4 DBP (dibutyl phthalate) 88, 198 Dead Sea Bromine Group 122 debromination 136 decabromodiphenyl oxide (DBDPO) 134 decabromodiphenyls 117,264, 269,271
decabromyldiphenyl (DecaBDE) 1 3 6 , 2 7 1 Decelox 105 Dechlorane Plus 132, 133, 134 DecillonLLC 54 degassing 249 degradation additives 2 2 1 , 2 3 8 Degussa 91 Degussa black process 84, 86, 89 DEHP (diethylhexyl-phthalate or DOP) 1 7 0 , 1 7 1 , 1 7 3 - 4 , 2 5 9 , 264-5 dendritic polymers 11 dessicant additives 2 3 9-40 detergents 11 Dexco (Exxon/Dow) 239 diactyl peroxides 154 dialkylhydroxylamine 101 diallyl phthalate (DAP) 172 dibromoneopentyl glycol (DBNPG) 1 1 7 , 1 1 8 , 1 2 2 dibromostyrene 118,122 dibutyl phthalate (DBP) 8 8 , 1 9 8 dichlorodifluoromethane (R 12) 1 7 8 , 1 8 5 dicyandiamide curing agent 157, 159,161 DIDA (diisodecyl adipate plasticizer) 170 DIDP (diisodecyl phthalate) 171, 174,175,265 diethyl stilbestrol 264 diethylaniline 154 diethylhexyl-phthalate see DEHP diisodecyl phthalate see DIDP diisononyl phthalate see DINP diisotridecyl phthalate (DITDP) 1 7 0 , 1 7 1 diketo-pyrrolo-pyrrols (DPPs) 67, 70-1 dimer acid modifiers 191, 19 5-6 dimethyl-p-toluidene 154 dimethy laniline 154 DINP (diisononyl phthalate) 1 7 1 , 174,175,265,272
Editorial Index
dioxins 1 2 1 , 1 3 6 - 7 , 263, 264, 267,269-71 dipheny 1 ethers 13 7,263 dispersion agents 23, 6 1 , 66-7, 181, 200, 226; s^ea/so pigments, dispersal dispersive mixing 2 5 0 , 2 5 1 , 2 5 3 5,255 DITDP (diisotridecyl phthalate) 170, 171 DJ Enterprises 92 DMC (dough moulding compounds) 3 8 , 5 0 , 2 2 2 dolomite 21 DOP see DEHP dosing equipment 245, 248, 252-3 dough moulding compounds (DMC) 3 8 , 5 0 , 2 2 2 Dover 121 Doverphos 96, 103 Dow 3 2 , 5 4 , 8 3 , 9 4 Dow Corning 2 1 2 - 1 3 Dow Insight ''constrained geometry' 194 DPPs (diketo-pyrrolo-pyrrols) 67, 70-71 DSM 1 1 , 1 7 , 4 8 , 5 2 , 1 2 3 , 1 4 8 , 282-3 DuPont 15, 4 1 , 82, 92, 194, 200, 202,220,222,239 Durastrength 300 modifier 192 dustcontrol 2 6 2 , 2 6 6 dust mites 221 DVD-R manufacture 6 5 dyes and dyeing 3 , 1 1 , 5 7 , 5 8-9, 64,65,66,70,275 DynamarPPA 202 Dyneon 202 Dynol 604 228
E-CR glass 4 5 , 4 6 E-glass 4 0 , 4 3 - 4 , 4 5 - 6 earthenware effect pigments
70
451
Eastman Chemical 241 ECC 196 ECP 2000 anti-static 145 edge-glow effect 7,62 Eeonyx 148 elastomer flame retardants 137 elastomer modifiers 192-5 elastomers 32 blowing agents 187 cross-linking 153 flame retardants for 1 2 2 , 1 2 6 , 135 heat stabilizers 95, 96, 97, 103 lubricants 212 modifiers 1 9 6 - 7 pigments 69 reinforcement 41 UV stabilizers 112 electrical and electronic applications 9, 2 4 - 5 , 141, 143-4,148-9,287 waste and recycling 1 3 6 , 1 4 4 , 270,278 electrical properties, testing 28 3-4 electromagnetic interference (EMI) compounds 144-7 electron beam curing 163-4 electrostatic discharge (ESD) compounds 144 Elementis 17, 71, 105 Elf Atochem 15, 18, 33, 111, 149, 184,192,226 ElftexTP 91 Elopak 242 EMI (electromagnetic interference) compounds 1 4 4 - 7 EMSChemie 211 enamels 161 EndexABS 50 foaming agent 186 Engelhard 6 7 , 7 0 , 2 75 Engineering Holcobatch 6 7 engineering plastics 5, 8, 16 anti-static properties 1 4 9 - 5 0 blowing agents 180 compounding 2 2 - 4 curing 151
452
Additives for Plastics Handbook
flame retardants 122, 126-7, 132,140 heat stabilizers 103,105 lubricants 205, 206, 208, 210 modifiers 1 9 0 , 1 9 1 , 195, 204 pigments 10, 63, 67, 69-70, 71, 80,91 processing aids 1 9 9 , 2 0 0 recyclability 239 trends 16 UV stabilizers 113 EniChem 193 environmental considerations 4 5, 57-8,97,105,106,114; see also health and safety Environmental Products 187 EPDM 121, 138, 153, 168, 175, 193-5 EPIcell700 187 EPIcor972 187 Epilin Heat Shield 900 65 epoxidation 234 epoxies coupling agents 167 curing 157-60 flame retardants 1 1 8 , 1 2 2 , 1 2 7 , 133,134,135 as heat stabilizers/ plasticizers 9 4 , 1 0 5 , 173,2 75 impact modifiers 198 equipment compounding 245-6 dosing 2 4 5 , 2 4 8 , 2 5 2 - 3 mixing 2 4 5 , 2 4 6 - 5 1 recycling 244 erucamide 2 0 8 , 2 1 6 ESD (electrostatic discharge) compounds 144 ethanol 185 ethoxylated alkylamines 143 ethoxylated amines 143 ethyl chloride 185 ethylene diamine phosphate 128 ethylene propylene terpolymer elastomer see EPDM ethylene vinyl acetate see EVA
ethylene vinyl alcohol (EVOH) 222 ethylidene norbornadiene (ENB) 194 ethyloxylated amines (EA) 143 EuropreneAR 193 EVA (ethylene vinyl acetate) 153, 180,187,191,211 EVOH (ethylene vinyl alcohol) 222 exfoliation 33 EXL 3600 238 Exolit 126 extenders 1 4 , 1 7 3 extrusion compounding 245, 248-51 Exxelor 194
Parrel 2 53 fatty acid amides and esters 143, 170-3,208-10,218,275 feeders 248,2 52 feldspar filler 20 Ferro 6 0 , 7 1 , 1 1 0 , 2 2 0 fibre/compatibilizers 2 39 fibres 3,3 7-56 anti-static/conductive coating 147 commercial trends 5 5-6 fibrillation 41 forms of reinforcement 51 glass see glass fibre heat stabilizers 95 high-performance 3 9 , 4 0 , 4 1 - 3 , 55 hybrid 3 9 , 4 9 , 5 1 long-length 3 7 - 8 , 4 7 , 5 1 - 4 , 2 5 5 natural 3 9 , 5 0 - 5 1 , 1 4 7 properties 3 9 - 4 0 pulping/fibrillation 41 shaped 54-5 short-length 3 7, 47, 51, 54-5 synthetic 39 with thermal insulation 2 2 5 - 6 UV stabilizers for 1 1 2 , 1 1 4 Fibril 34
Editorial Index
filament winding 46,127,157, 160 fillers 3 , 1 9 - 3 5 , 8 0 - 8 1 , 1 9 6 - 7 , 249 aggregation 2 3 - 4 coating 31 commercial trends 3 5 compounding/mixing 22-4, 246-7,249,254 forCPEE 1 9 6 - 7 health and safety 2 5 8 , 2 6 2 mineral 1 9 6 - 7 , 2 4 9 nano-technology 3 0 , 3 2 - 5 particle geometry 2 1 - 3 , 30-1 reinforcing 3 7-56 for rubber 232 surface modification 3 0 - 1 , 1 9 9 white 8 0 - 1 world trends 6 - 7 , 3 2 Filolen 10 Filtec 181 Filtron 66 Firebrake 1 2 4 , 1 2 5 Firemist 70 flame retardants 3 , 8 - 9 , 1 1 5 - 4 0 and char formation 124,125, 126,127 combinations 130-1 fillers 3 1 , 3 2 , 3 5 halogen-free 128-9 halogenated 9, 35, 117, 120-3 health and safety 1 3 5 - 6 , 2 5 8 , 259,263-4 intumescent 12 7-8 legislation 2 6 9 - 7 1 , 2 7 8 new developments 13 7-9 reactive 118 recycling 9, 1 3 6 - 7 , 2 4 1 synergism/blends 116,120, 126,127,132-5 tests 1 1 6 , 2 8 4 - 9 5 trends 6 , 8 - 9 , 1 5 , 1 3 9 - 4 0 world consumption 14,139 flammability tests 2 8 4 - 9 2 fiax fibres 5 0 - 1 Flex-Wall 248
453
flexibilizers 198 flint powder 2 ''flip-flop" pigments 7 , 6 3 - 4 flow modifiers 6 7 , 2 0 2 - 3 , 2 0 8 , 210,240-41,252 fluorescent pigments 64 Fluoroguard 200 fluoropolymers 125, 199, 2 0 2 - 3 , 211-12,244,275 Fluorox 240 fly ash ''floaters" 30 EMC 16 foam control additives 2 2 8 - 9 foamed materials 177-87 food contact anti-static additives 142-2 barrier property improvement 2 2 2 - 5 biocides 2 2 0 , 2 2 1 blowing agents 1 8 0 - 8 1 fluoroplastic processing aids 212 foam control systems 228 health and safety 263 heat stabilizers 94, 96, 98, 102-3 legislation 263, 2 70, 2 73-7, 294 lubricants 2 1 0 - 1 1 pigments 6 7 , 6 9 , 8 3 , 9 1 plasticizers 7, 171, 173 processing aids 2 0 2 - 3 , 2 1 2 slip and anti-blocking agents 2 1 5 , 2 1 6 - 1 8 special additives 9 UV stabilizers 1 1 3 , 1 1 4 footballs, high-performance 182 Forane 141b 184 Ford 244 formaldehyde 159-60, 161 fractal dimension 22 fragrance additives 226 free radicals 93, 1 0 0 - 1 , 102, 108, 109-10 and curing 152, 153, 162, 163 andHCFCs 182-3
454
Additives for Plastics Handbook
friction reduction 7 8 , 4 3 , 2 0 6 , see also anti-blocking; slip FS Systems 9 6 , 1 1 1 fuUerene tubes 34 functionalized polymer processing aids 199 fungicides 2 1 9 - 2 1 furans 136-7, 263, 2 6 9 - 7 1 furnace black process 84, 8 5-6, 89,232 furnace blacks 8 8 , 9 1 , 9 2 Fusabond compatibilizers 239 FXNiteBrite 65
gamma ray sterilization resistance 104 Garosorb 240 gas barrier coating 223 gas black process 84, 86, 89 gas generation, in-house 181 gas-forming chemicals 3 gassing, direct 180 GE Silicones 2 1 6 - 1 7 GE Specialty Chemicals 9 6 - 7 , 103, 105,190,199,239 gel coats 1 2 6 , 1 2 7 , 2 2 0 , 2 2 1 , 292 GenoxEP 105 Gentex 66 geometrical surface area 8 8 Geon 54 Giovani 242 glass 3 chopped 2 flaked 2,48 pigments 70 powdered 2 glass fibre flame retardant 132 glass fibres 20, 39, 40, 4 3 - 8 , 56, 79,255 forms 4 7 - 8 , 5 1 - 4 health and safety 2 4 9 , 2 5 8 , 2 5 9 , 262 preforming 4 7
glass fillers 197; see also microspheres glass mat thermoplastics (GMT) 51 globalization 15 gloss 7 , 7 4 , 1 0 8 , 1 7 2 , 1 9 6 , 2 1 8 , 222,223 ''glow-in-the-dark"pigments 65, 71 glycerol monostearate (GMS) 143 glycerol stearate 142 glycol ether modifier 198 glycol methacrylate 173 GM 32 Grace (WR) 15 Graham Packaging 223 GranufinCarbonP95 91 graphite 32 fibres 2 0 , 3 9 , 4 1 , 4 9 fillers 2 0 , 3 4 , 3 9 , 4 1 , 4 9 , 1 9 7 flame retardant 12 7-8 lubricant 205 nano-tubes 34 GraviblendS 60,2 52 GreatLakes 15, 17, 18, 105, 114, 122 green fibres 50 greenhouse applications 6 4 , 6 5 , 110,111,113,114 greenhouse effect 182 GretagMacbeth 2 5 3 , 2 9 4 GrilonMB 211 Grit-0'Cobs 30 grouts 161 Gusmer-Admiral 187 gypsum 21
H H-CFC (hydrochlorofluorocarbon) 178 halogenated CFCs (HCFCs) 1 8 2 - 3 , 184,186 halogenated flame retardants 9, 35, 117, 1 2 0 - 3 , 1 3 3 , 2 6 3 - 4 , 2 7 1 , 278 halogenated flame-retardant plasticizer 175
Editorial Index
HALS 8 , 9 7 , 1 0 9 - 1 1 , 1 1 2 , 1 1 3 , 114,168,282 hand lay-up processes 1 2 7 , 1 5 7 Hanna 63, 64, 65, 70, 128,162, 252 hard coatings 225 hardeners 1 5 2 , 1 5 7 hardness 7 8 , 2 9 2 - 3 HAS (hindered amine stabilizers) 1 0 2 , 1 0 9 hazards see health and safety; testing HCFCs (halogenated CFCs) 1 8 2 - 3 , 184,186 HDPE blowing agents 180 fibre/compatibilizers 239 and pigments 62, 63, 68, 70 processing aids 211 recycling 238, 239, 2 4 1 , 242 world production and consumption 14 health and safety 5,6, 1 3 5 - 6 , 2 3 3 , 249,257-68 guidelines 2 6 7 - 8 see also food contact; medical/ healthcare applications; toxicity heat ageing 281-2 heat protection for food products 65 heat release rate 286 heat resistance additives 3 heat stability, of pigments 62, 67, 69,71,238 heat stability testing 281-2 heat stabilizers 9 3 - 1 0 6 blends 97 and heavy metals 9 4 , 9 7 - 8 , 1 0 6 legislation 97 new chemistry 100-3 trends 105-6 heavy metal reducing agents 153 heavy metals 7 , 8 , 2 6 6 - 7 in fillers 31 legislation 2 7 0 , 2 7 1 - 2 , 2 7 9 in pigments 5 7-8, 61-2, 79, 266,270,271-2
455
in stabilizers 9 4 , 9 7 - 8 , 1 0 6 , 111-2,266 helicone flakes 64 Hennecke 3 2 , 1 8 5 heptane 178 HEX acid 118 Heudijk Kunstofl'en BV 239 hexabromocyclododecane 122, 134 Hexcel 56 HFA (hydrofluoroalkane) 178 HFCs (hydrofluorocarbons) 184, 185,186 Hi-Strength 63 High Activity (HA) 204 hindered amine light stabilizers see HALS hindered amine (NOR) 134 hindered amine stabilizers see HAS hindered phenolics 95, 1 0 1 , 2 3 7 Hoescht 17 Holland Colors 67 HoUiday Pigments 70 Honeywell 184 Hordaresin 121 horticultural applications 6 4 , 6 5 , 110,111,114 Hosokawa Mikron 248 HP-136 101 Huber 119 Hubron 91 Hiils 67 Huntsman 18 Hybrane 11 HyciteEXM 114 hydrazide blowing agents 179 hydrocarbon extenders 173 hydrocarbon lubricants 2 0 5 , 2 0 7 hydrofluorocarbons (HFCs) 184, 185 hydrogen peroxides 15 hydroperoxide decomposition 94, 100 hydrophilic copolymers 150 hydroxyalamines 96, 111 hydroxybenzoate ester 1 1 0 - 1 1
456
Additives for Plasties Handbook
hydroxybenzophenone 111 Hymod 119 hyperbranched additives 11 Hyperion Catalysis International 11 hysteresis 50,65
I ICI 15,17 identification of plastics 2 4 1 - 4 Imetal 18 impact modifiers 3 , 1 8 9 - 9 2 , 203-4,207,239 impact strength tests 281-2 incineration 2 6 7 , 2 6 9 - 7 0 infrared marker systems 2 4 1 , 242 infrared radiation, and HCFCs 182-3 infrared radiation protection pigments 6 4 , 6 5 , 8 9 inherently conductive polymers (ICP) 147-8 inhibitors 152, 157 initiators 1 5 2 , 1 5 3 , 160 Injecta Color 67 injection moulding 4 8 , 1 4 9 , 1 5 7 , 181,187,208 insulation see acoustic insulation; thermal insulation intensive mixing 250 Intercide range 220 interfacial bonding 6 Interlite range 104,238 Intertech 72 intumescent flame retardants 12 7-^ IPDA (isophorone diamine) 160 IPDI (isophorone di-isocyanate) 160 Irgafos 168 stabilizer 238 Irganoxrange 97, 101, 102, 238 IrgastabCZ2000 238 Irgastat range 150 iridescent polymers 64 iron oxides 58, 63, 66, 120, 132, 133
iron reducing agents 153 iso-pentane 30 isocyanates 152, 187, 260 isoindoline 69 isophorone di-isocyanate (IPDI) 160 isophorone diamine (IPDA) 160 isoprene, cross-linking 153 Isozindigo 71
I jetness 8 9 , 9 0 JMACbiocides 220 Johnson Matthey 220 jute fibres 3 9 , 5 0 K Kane Ace FM 192 kaolin 7 , 2 6 , 4 3 fillers 2 0 , 2 6 , 3 5 , 1 3 1 pigments and extenders 80, 81 Kemgard 12 5 Kemira Pigments 63 Kerr-McGee 1 5 , 1 7 , 9 2 ketones, for curing 1 5 4 , 1 6 0 ''kickers" 105 Kraton polymer range 193-4, 200 Krupp 242 Krupp Werner and Pfleiderer 5 3, 2 50 K VG Kunstoff-Verarbeitungs 5 4 Kyowa 129
lactone chemistry for stabilizers 100-2 lampblack process 84, 86, 89 lampblacks 88 landfill hazards 2 6 6 - 7 Lapinus Fibres 239 laser marking 7 , 6 5 , 6 6 laser welding 66
Editorial Index
laser-induced emission (LIESA) technology 2 4 2 - 4 laureates 98 LDPE blowing agents 180 lubricants 208 processing aids 211 recycling 239 slip and anti-blocking 2 1 5 , 2 1 7 UV stabilizers 110 world production and consumption 14 lead 263, 2 7 1 - 2 , 273, 274, 279 in pigments 6 1 - 2 , 2 7 1 - 2 in stabilizers 7, 8, 94, 97, 99, 106,266-7 legislation 6 , 9 , 1 0 , 2 6 9 - 7 9 database on CD/ROM 294 light interference pigments 63-4 light stability 6 2 , 1 0 5 , 2 8 2 light stabilizers 1 1 0 - 1 1 , 1 1 4 ; see also UV stabilizers light-conducting pigments 64 lignin 41 limiting oxygen index (LOI) 116, 286 LinFlex 185 linseed oil plasticizer 275 liquid colours 3, 7, 59-60, 2 52-3 liquid mixing systems 2 4 6 - 7 liquid stabilizers 94, 98, 105 LNP Plastics 52-3 low-profile additives 222 low-temperature flexibility 200, 204,207,213 Lowilite 114 lubricants 3, 7, 199, 172, 2 0 5 14 combination and modification 2 1 3 - 1 4 legislation 2 72 for performance improvement 2 0 5 - 6 in pigments 67, 78 as processing aids 2 0 6 - 1 3 world consumption 14
457
LuchemHA-R100 113 luminescent pigments 64, 65 LumiNova 71 Lumogen F 64
M magnesium hydrotalcites 114 magnesium hydroxide 3 1 , 3 5 , 1 1 7 , 118, 119-20, 125, 126, 128, 131, 140; see also talc magnesium silicate 8 1 , 1 3 3 magnesium sulphate 21 Magnetic Separation Systems (MSS) 242 MagShield 120 Maguire Products 252 manganese 58 MarkEZ 104 marker additives 2 3 8 , 2 4 1 - 4 Martin Marietta 120 Massen Machine Vision Systems 242 masterbatches 245, 249, 251 of anti-static additives 144-5 for elastomers 41 electrically conductive carriers 149 of fine talc 249 with fragrance 226 of lubricants 211 with mould release agents 2 1 4 16 ofpigments 6 0 , 6 3 , 6 7 , 6 9 , 7 1 , 80,202,211 black 9 0 , 9 1 , 9 2 white 8 2 , 8 3 silicone 212 slip and anti-blocking 2 1 5 , 2 1 6 for thermoplastics 4 1 , 1 6 2 - 3 trends 1 0 , 6 0 , 7 1 UV stabilizers 113-14 world market 15 mats, reinforcement 3 8 , 3 9 , 4 6 - 7 , 47 MatVantage 46
458
Additives for Plastics Handbook
MBS (methyl butadiene styrene) 9 5 , 1 9 0 , 1 9 1 , 2 0 0 Mearlin Dynacolor 63 medical/healthcare applications anti-static additives 144, 145 heat stabilizers 9 6 , 1 0 3 , 1 0 4 - 5 legislation 2 72,2 77 lubricants 2 1 0 - 1 pigments 6 9 , 8 0 plasticizers 7 , 1 7 1 , 1 7 3 - 4 , 265 special additives 9 MEGAcompounder 2 50 melamine 79, 1 5 9 - 6 0 , 1 6 1 , 272 flame retardants 117, 120, 1 2 3 4,130-1,132 Melapur 1 2 3 - 4 mercaptane 160 Merck 66 mercury 2 74 mergers and takeovers 17-18 MetablenS-2001 192 metakaolinite 26 metal filaments 20 metal hydroxide flame retardants 1 1 9 , 1 2 5 - 6 , 1 3 2 metal soaps 98, 105 metaUic anti-static additives 1 4 4 7,148-9 metallic cure promoters 160,232 metallic fillers 2 , 2 0 , 2 8 metallic pigments 5 8 , 6 3 , 6 6 metallic reducing agents 153 metallic stabilizers 94, 98, 105 metallic stearate lubricants 205, 207 metallurgical carbon 92 metaphenylene 158 Meteor Plus 69 methyl alkyl poly siloxane 229 methyl butadiene styrene see MBS methyl chloride 178,185 methyl methacrylates 1 0 7 , 2 1 4 methyl styrene processing aids 199 methyl tin stabilizers 9 8 methylene chloride 179 methylene dianiline 158
2-methylimidazole (2-MI) 159 mica 2 , 3 , 7 filler 2 0 , 3 1 , 1 9 7 , 1 2 1 in pigments 6 3 , 6 6 Microart fabrics 2 2 5 - 6 Microban 220 Microfree 220 Microlen 69 Micronyl-Wedeco 242 microspheres expandable 2 9 - 3 0 gas-filled 182 hollow 2 0 , 2 9 microgranular 70 polyacrylonitrile 30 solid 2 0 , 2 8 , 1 9 7 migration of elements 2 73-4 Mikro-Chek 220 Millad range 2 0 0 1 , 2 75 milled products 4 7-8 Millennium 1 5 , 1 8 , 9 2 Milliken 6 0 , 9 0 , 2 0 1 , 2 75 mineral flame retardants 1 3 0 - 1 Miraflex fibre 46 Mitsubishi 56 mixing equipment 245, 2 4 6 - 5 1 ; see also compounding modified atmosphere packages (MAP) 22 5 modifiers 3, 11, 14, 1 8 9 - 9 8 , 234, 240-1,261 MoldWiz INT-VP2 50 2 1 4 - 1 6 molybdenum disulphide 2 , 1 9 7 molybdenum disulphite lubricant 205 molybdenum-based flame retardants 1 2 5 - 6 , 1 4 0 Montan waxes 210 Montell 3 2 , 1 1 4 montmorillonites 32 Morton 1 5 , 6 7 mould release agents 3 , 2 0 6 - 7 , 208,214-16,217-18,229 mould sealant and conditioner 229 mould treatment agents 229 moulded circuitry 148-9
Editorial Index
Miiller Recycling 242 multi-functional systems 132,207 Multibase 52 Multisperse 240 myristates 98
5,10, 67,
N N-alkoxy hindered amine (NOR) 134 nano-technology 3 2 - 5 , 1 0 5 , 1 3 8 9,254,255 Nanocor 222 National Recovery Technologies 242 natural effects pigments 70 naturalfibres 39, 5 0 - 1 , 147, 197 natural gas 84 Nemoto 71 neoprene 121 nepheline syenite 20 Nestle 2 77 Neutrabac 221 nickel 5 8 , 1 0 9 , 1 1 1 , 1 1 4 , 1 4 6 Nissin Electrical 225 nitrile flame retardants 121 nitrogen blowing agents 178,179, 241 nitrogen surface area 8 8 nitrogen-based curing agents 198 nitrogen-based flame retardants 128, 140 NL Industries 92 Nord-Min 127 NordellP 194 Nourymix technology 150 Novablend 248 nucleating agents 3, 10, 67, 178, 180,181,199-202,229,275 nylon clay hybrid (NCH) 222 nylon fibre reinforcement 39,49 nylons anti-static/conductive additives 1 4 7 , 1 4 8
459
blowing agents 186 coupling agent 168 fibres with thermal insulation 2 2 5 - 6 flame retardants 1 2 0 , 1 2 2 , 1 2 3 , 132,133,137 gas permeability 222 heat stabilizers 9 6 , 1 0 3 impact modifiers 1 9 1 , 1 9 3 lubrication 211 processing aids 199 reinforcement with carbon fibre 42 twin-screw extruders 250 Nylostab S-EED 114
O OBPAbiocides 2 1 9 , 2 2 0 Occidental 133, 134 octabromodiphenyl 1 3 4 , 2 6 4 octyl phenol 264 octyl phenol polyethoxylate 2 64 octyl tin mercaptides 9 8 oil absorption 88 oleamide 2 0 8 , 2 1 6 olefinic impact modifiers 191 oligomeric plasticizers 170, 172 opacity 25, 76-7 optical brighteners 1; see fl/so whiteness organic fillers 20 organo-clay fillers 34 organometallic coupling agents 167-8 organometallic heat stabilizers 94, 97,98-9,103,106 organotin heat stabilizers 9 7 , 9 8 9,103,106 organotitanates 246 Owens Corning 46, 52, 54 oxidation prevention 3 oximes 232 oxygen absorption 2 2 4 - 5 oxygen scavaging (OS) 225 ozone depletion 182
460
Additives for Plastics Handbook
PA (polyamides) 7, 51, 54-5, 70, 110 packaging 9 anti-fogging 22 7 anti-static 143, 144 legislation 2 70,2 73-8 lubrication 211 masterbatches 83 oxygen absorption 2 2 4 - 5 pigments 6 8 , 6 9 plasticizers 171 waste 6 2 , 2 4 2 , 2 7 7 , 2 7 8 ; see also recycling Paliotol 69,2 75 PAN (polyacrylonitrile) 41 paraffinic sulphonic acid phenyl ester 170 paraffins, chlorinated 1 1 8 , 1 7 3 , 259 Paraloid range 190, 192 particle geometry carbon blacks 8 6 - 7 fillers 2 1 - 2 , 2 3 , 8 0 pigments 6 1 , 77, 80, 8 2 - 3 , 8 6 - 8 and plasticizers 174-5, 261 particulate reinforcement 3 7-8 PBDD/F 136 PBDE (brominated diphenyl ether) 263 PBT flame retardants 122, 128-9, 132,133,135,137 lubricants 212 modifiers 1 9 0 , 1 9 1 , 1 9 6 , 2 0 3 reinforcement 51 PC see polycarbonate PCBs 140 PDMS (polydimethylsiloxane) 197 PE see polyethylene pearlescents 7 , 6 2 , 6 3 Pebax copolymers 149-50 PEEK compound 149 pentabromobenzyl acrylate 117, 122 pentabromodiphenyl 134,264
pentane 1 7 8 , 1 8 3 , 1 8 4 - 5 peptizers 232 peresters 154 perketals 154 perlite 29 peroxide curing agents 152-7, 162,232,261,262 perylene 69 PET alloying agents 204 blowing agents 1 8 0 , 1 8 7 flame retardants 133, 135 and gas permeability 2 2 2 - 5 heat stabilizers 9 6 , 1 0 3 liquid colours 60 lubricants 212 modifiers 1 9 1 , 1 9 6 , 2 0 3 - 4 recycling 223, 238, 239, 2 4 1 , 242,243 UV stabilizers 1 1 2 , 1 1 4 phenol/formaldehyde curing agent 1 6 0 , 1 6 1 phenolic antioxidants 9 4 , 9 5 - 6 phenolic/phosphite blends 94 phenolics, flame retardants 122, 135 phosphate ester flame retardants 118, 120 phosphated fatty acids 7 5 phosphates 15-16 phosphites/phosphonites 9 4 - 7 , 101,103,198,237,275 phosphonic acid 143 phosphorescent pigments 6 5 , 7 1 phosphorus-based flame retardants 117, 118, 120, 126 7,128,134,140 phosphorus-based modifiers 197 photo/repro additives 2 photochromicpigments 64, 275 photodegradation 107 photoinitiators 162 photoluminescent pigments 6 5 photopolymers, cure enhancers 162 photoreactive chemistry 113
Editorial Index
photovoltaic cells 64 phthalates 3, 7 , 1 6 9 - 7 1 , 2 6 4 - 5 , 272-3,292 phthalocyanine blue 68 pigments and colorants 2 , 3 , 7 , 5 7 72,249 black see black pigments chemistry 5 9 , 7 0 - 1 dispersal 57, 6 0 - 1 , 66-7, 77, 78,204,275 for food contact use 2 75 health and safety 249, 258 high performance 6 9 - 7 1 , 7 2 inorganic 57,59 ''intelligent systems" 2 75 legislation 57-8, 2 70, 2 71-2 light fastness 6 4 , 1 0 5 , 2 75 metallic 7,58 microgranular 70,91 multi-functional 6 7 opacity 76-7 organic 5 7 , 6 1 , 6 4 , 6 5 , 6 7 , 70-1 particlesize 6 1 , 7 7 , 8 2 - 3 recent developments 6 9 - 7 1 , 2 7 5 for recycling 238 special effects 7, 6 2 - 5 , 70, 12 7 tinting strength 76-7 trends 6 , 7 , 6 1 - 2 , 7 1 - 2 , 9 2 for UV screening 108-9 warpage and shrinkage 62, 68 white see white pigments world consumption 14 pine oil modifier 198 PIRA 244 pitch-based carbon fibres 4 1 , 4 2 , 147 Plasadd 1 9 9 - 2 0 0 Plasblak 9 1 , 1 1 4 plasma technology 2 2 4 , 2 2 5 plasticizers 3, 7 , 1 6 9 - 7 5 , 220, 232 for food contact use 2 75 health and safety 2 5 8 , 2 5 9 , 260-1,264 legislation 2 72-3 migration reduction 191
461
world production and consumption 1 4 , 1 7 5 plastisols 7 4 , 1 7 4 - 5 , 1 7 9 , 226, 229,261 PlaswitePE7474 83 PMMA barium sulphate filler 80 legislation 2 72 and luminescence 64 modifiers for 197 as processing aid 200 PMMA shell 203 polyacetal 206 polyacrylonitrile (PAN) 41 polyalkylane derivatives 229 poly amide modifiers 198 polyamides alloying agents 204 for beer bottles 2 2 3 - 4 blowing agents 180 curing agents 1 5 8 , 1 6 0 , 1 6 1 , 261 dessicants 240 fibre/compatibilizers 239 flame retardants 122, 128, 135 heat stabilizers 9 5 , 9 7 , 114 laser identification 244 lubricants 205, 206, 2 1 0 - 1 1 , 212 modifiers 1 9 1 , 1 9 6 , 2 0 4 UV stabilizers 1 0 9 , 1 1 2 , 1 1 4 weather stability 79 poly aniline 148 Polybond 168 polybrominated diphenyl oxide (BPDO) 1 1 7 , 1 2 2 , 2 6 9 - 7 0 polybutadiene 1 5 3 , 1 5 3 polybutenes 1 9 1 , 1 9 5 poly(butylene terephthalate)s see PBT polycarbonate/PEEK semiconductor wafer carrier 149 polycarbonates blowing agents 1 8 0 , 1 8 6 , 1 8 7 coupling agents 167 filler 80
462
Additives for Plastics Handbook
flame retardants 122,135 heat stabilizers 96, 9 7 , 1 0 3 impact modifiers 1 9 0 , 1 9 1 , 203 laser identification 244 lubricants 212 pigments 6 4 , 6 5 recycling 238 UV stabilizers 107 POLYcor range 187 polydimethylsiloxane (PDMS) 197 polyesters anti-static/conductive additives 147,148 black pigment 89 coupling agents 167 curing 152-3 fillers 24 flame retardants 118, 1 2 1 , 1 2 2 , 124,127,133,134,135,137 health and safety 257 heat stabilizers 9 5 , 9 7 legislation 2 72,2 75 modifiers 1 9 1 , 1 9 4 , 1 9 6 , 2 0 3 , 204 mould release agents 214 plasticizers 172 polyester fibre reinforcement 48 trends 7 UV stabilizers 109,112, 113-14 see also FBT;FET poly (ether ketone)s 125 poly (ether sulphone)s 12 5 polyethylene alloying agents 204 anti-static additives 150 ballistic properties 48 blowing agents 1 7 9 , 1 8 7 chlorinated 94 cross-linking 1 5 3 , 2 4 0 fibre 4 8 - 9 flame retardants 1 1 8 , 1 2 1 , 1 2 7 , 135 health and safety 263 heat stabilizers 9 5 , 9 7 legislation 2 71,275 lubricants 212
in masterbatches 15 masterbatches with fragrance 226 modifiers 1 9 1 , 1 9 5 pigments 6 8 , 8 3 , 8 9 , 9 1 processing aids 211 recycling 2 4 0 , 2 4 2 , 2 4 3 twin-screw extruders 250 ultrahigh-molecular-weight 48 UV stabilizers 1 0 9 , 1 1 2 , 1 1 3 , 114 world production and consumption 14; se^fl/soHDPE;LDPE;PET polyethylene lubricant 205 polyethylene wax dispersants 6 6 polyisocyanurate foam insulation 184 polyisoprene modifier 192 polymeric additives 7,20, 111, 167,170,172 poly(methyl methacrylate) see PMMA polyolefin impact modifiers 194-5 polyolefin waxes 210 polyolefins 5, 6-7, 15 anti-blocking agents 216 anti-static agents 1 4 2 , 1 4 3 , 150 blowing agents 187 co-stabilizers 114 colour-critical 96, 103 coupling agents 168 dessicants 240 fibre/compatibilizers 239 fillers 24 flame retardants 122, 125, 128, 130,134,140 gas permeabihty reduction 222 heat stability testing 282 heat stabilizers 94, 96, 97, 102-3,105,114 fight stabilizers 1 0 5 , 1 1 4 lubricants 2 0 5 , 2 0 8 , 2 1 2 metallocene-catalyzed 16 modifiers 1 9 1 , 1 9 2 - 3 , 1 9 6
Editorial Index
and pigments 62, 67, 68, 69, 71, 83 plasticizers 175 processing aids 1 9 9 , 2 0 2 - 3 UV stabilizers 107, 109, 113, 114 world production and consumption 14 polyols 7 5 , 7 6 , 1 4 3 , 1 5 2 , 1 8 7 polyphenylene ether 186 polyphenylene sulphide 167,206 polypropylene 7 , 1 1 , 1 5 alloying agents 204 blowing agents 179, 180,187 clarifying/nucleating agents 200-2 compounding equipment 250, 255 coupling agents 121 dyeing 11 fillers 24 flame retardants 1 2 1 , 1 2 2 , 1 2 4 , 125,130-1,133,135,137, 138,175 health and safety 263 heat stabilizers 9 5 , 9 7 , 101 impact modifiers 191, 192, 194 legislation 2 71,2 72 lubricants 2 0 8 , 2 1 2 , 2 7 5 pigments 6 2 , 6 8 processing aids 1 9 9 , 2 0 0 - 2 , 212 recycling 238, 239, 240, 243 reinforcements 5 3 UV stabilizers 1 0 8 , 1 1 1 , 1 1 2 , 113 world production and consumption 14 polypropylene fibres 5 0 - 1 , 6 2 polypropylene filaments 46 polypropylene nano-composites 34 polypropylene wax dispersants 6 6 polypyrrole 148 polystyrene alloying agents 204 anti-static agents 142
463
blowing agents 179, 180, 185-6, 187 flame retardants 120, 1 2 1 , 122, 132,133,134,135,136 health and safety 1 3 6 , 2 6 3 heat stabilizers 9 5 , 9 6 , 9 7 , 103 legislation 2 71 lubricants 172, 205, 208, 212 modifiers 1 9 1 , 1 9 2 , 1 9 5 nucleating agent 229 pigments for 6 2 , 7 1 , 9 1 recycling 1 3 7 , 2 3 9 , 2 4 2 , 2 4 3 UV stabilizers 109 world production and consumption 14 polysulphides 1 6 1 , 1 9 8 , 2 1 9 polyurethane/glass fibre reinforcement 54 polyurethanes anti-fogging arMiliveii 2 2 6 - 7 anti-microbials 2 1 9 , 2 2 0 black pigments 90 blowing agents 1 7 7-8 7 coupling agents 167 curing 152, 1 60 flame retardants 120, 122, 123, 135, 140 health and safety 2 57 heat stabilizers 9 4 , 9 5 , 9 6 , 101-2,103 legislation 269 reaction injection moulding 48, 54,90 UV stabilizers 1 0 7 , 1 1 0 , 1 1 2 Polyvel 240 potassium 105 PP see polypropylene PPG Industries 4 6 , 2 2 3 PPO 115, 1 1 6 , 1 3 5 , 1 8 0 , 2 1 2 pre-impregnated products 4 8 , 49, 51 press-moulded compounds 38 Prestige R 70 "prill" 181-2 primary amides 2 0 5 , 2 0 8 , 2 1 6 Printex 91
464
Ackliilves for Plastics Handbook
Prism HP 181 processing aids 3, 7, 14, 189, 1 9 8 200,231-2,275 promoters 152, 160, 167, 195, 232,233,262 ProPalette 253 Pryltex 52 PTFE 2 0 5 , 2 0 6 PU see polyurethanes PuIisol-9 229 pulping 41 pultrusion 51,12 7 PVC anti-fogging additives 2 2 6 - 7 anti-microbials 2 1 9 , 2 2 0 anti-static agents 1 4 2 , 1 4 3 blowing agents 179,180, 187 co-stabilizers 114 cure enhancers 162 flame retardants 118, 120, 122, 1 2 7 , 1 3 3 , 135,140 glass fibre reinforcement 54 health and safety 260, 264, 266, 267 heat stabilizers 94, 9 5, 96, 98, 99,100,103-4,105,106 impact modifiers 190-2 inherent flame retardancy 115, 116 legislation 2 72,2 75 lubricants 205, 208-10, 212 matting agent 226 mixing 2 4 7 - 8 mould release agents 214 pigments 62, 69, 71, 74, 83, 89, 91 plasticizers 169-75 processing aids 1 9 9 , 2 0 0 recycling 2 3 8 , 2 3 9 , 2 4 0 , 2 4 1 , 242,243 UV stabilizers 107, 108, 110, 111-12,114 world production and consumption 14 PVC/EVA graft polymer 170
0 Quantum 1 8 7 , 2 3 8 quartz glass 40 quenchers 108, 109 quinacridone red 68 R R-glass 4 0 , 4 4 radiation curing 1 6 4 - 5 , 2 3 2 radical scavengers 9 5 , 1 0 1 , 1 0 8 , 109-11,225 radioactive elements in pigments 65 ramie fibres 50 rare earths 61 Rauwendaal Extrusion Engineering 2 51 rayon fibres 39 reaction injection moulding 4 8 , 5 4 recycled materials 63, 94, 104, 240 recycling 3, 143-4, 2 2 1 , 2 3 7-44, 2 70 and flame retardants 9 , 1 3 6 - 7 , 241 Recyclostab 238 red phosphorus 126 red pigments 6 7 , 6 8 , 6 9 , 2 7 5 reducing agents 15 3, 179 ReedSpectrum 67 refrigeration applications 184, 185,186 reinforcement 2 1 - 2 , 1 4 2 , 1 8 9 , 231,233,235,246 Reprise 242 resin transfer moulding 12 7 resistivity testing 283 resorcinol additives 2 2 3 - 4 retted fibres 50 Rhodia 16,18 Rhovyl 221 Rockfil 239 Rocknet 239 RohmandHaas 1 8 , 1 9 0 , 2 3 8 Royaltuf 1 6 8 , 1 9 4
Editorial Index
RTP 16, 32, 34, 52, 65, 149, 206 rubber 2 3 1 - 5 accelerators 232 anti-microbials 220 blowing agents 187 carbon blacks 84, 92, 232, 233, 234 cross-linking 153,232 curing 232 flame retardants 121 health and safety 233 modification 2 3 4 - 5 processing aids 231 reinforcement 2 3 1 , 2 3 3 , 2 3 5 tyre skid performance 2 3 3 - 4 UV stabilizers 110 rubber-based additives 1 9 2 - 5 , 2 3 8 rutile 73, 74, 76, 78, 81, 83, 1 0 8 9,275
S-glass 44 Sachtleben Chemie 65,275 Safe FR500 12 5 safety sec health and safety; legislation SAN 9 1 , 9 7 , 2 3 9 SanduvorPR-31 113 Sartomer 162 SB rubber 1 1 0 , 1 2 1 , 2 3 5 scavengers 95, 101, 108, 1 0 9 - 1 1 , 225 Schulmann 6 0 , 7 1 , 8 3 SCM Chemicals 83 scorch resistance 101-2 sealants 161 sebacates 170 selar platelet technology 222 selenium 6 6 , 2 74 self-colouring 10 SGL 56 Sherwin Wilhams 125 Shimadzu 292 shrinkage and warpage 3 , 6 2 , 6 8 , 222
465
SibnerHegner 65 Sidel 224 silane 2 5 , 2 7 , 3 1 , 5 0 , 1 6 2 - 3 , 167, 168,234 silica 2 , 7 , 3 2 - 3 , 3 5 effect on activity of stabilizers 9 9 - 1 0 0 and skid performance 2 3 3 - 4 silica anti-blocking agents 216 silica fillers 20,2 7 - 8 , 3 5 silica gel 3 5 , 1 8 3 silica treatment of titanium dioxide 75 silicon modifiers 1 9 1 , 1 9 7 , 204 silicon-based flame retardant 13 7 Silicone Antifoam Emulsions 229 siUconelubricants 199, 205, 2 1 2 13 silicone polymer 64 siloxanes 75 silver-based antimicrobials 220 SintoKogyo 149 sisal 39, 50 SKEPT (ethylene/propylene terpolymer) 138 skid performance 2 33-4 shding spark technology 242 slipagents 3, 1 5 0 , 2 0 8 , 2 1 1 , 2 1 5 , 216-18 Slip-Ayd 217 slurry processes 3 3-4, 2 55 smectite 32 smoke suppression 9 , 3 1 , 3 5 , 1 1 6 , 128,134 smoke tests 2 8 7 - 8 sodium alkyl sulphonates 143 sodium bicarbonate 179 solar heat blocking pigments 6 5 Solutia 16 solvents 229, 2 5 8 , 2 5 9 , 2 6 1 , 262, 2 70 SorbacidEXM 114 sound insulation 3, 19,22 7-8 soya bean oil 170, 1 7 3 , 2 7 5 special effect pigments 3 , 6 2 - 5 SpectraFlo 60
466
Additives for Plastics Handbook
Spectratech 187,238 spectrometry techniques for recycling 2 4 1 - 4 Splash Lube Gold 206 spray lay-up 157 stabilizers 3, 7,8, 1 4 , 1 5 , 1 1 1 effect of silica 9 9 - 1 0 0 for food contact use 2 75 health and safety 258 for recycled material 2 3 7-8 see also heat stabilizers; light stabilizers; UV stabilizers static decay 284 stearamide 2 0 8 , 2 1 6 stearate heat stabilizers 9 8 stearate lubricants 172, 205, 207, 208 stearate plasticizers 170, 172, 173 stearic acid-coated fillers 7 , 2 5 , 3 1 steel 2 8 , 4 0 , 1 4 4 - 7 strength tests 280-82 strontium oxide aluminate pigments 71 structural foams 180-82 styrenemonomer, safety 2 5 9 - 6 0 , 261,262 styrene processing aids 1 9 9 , 2 6 0 styrenic impact modifiers 191, 192,193-4 styrenics anti-static additives 1 4 3 , 1 5 0 blowing agents 187 cross-linking 153 flame retardants 122,140 heat stabiUzers 96, 103 impact modifiers 191 lubricants 2 0 5 , 2 0 8 pigments 6 2 , 6 4 world production and consumption 14 Sud-Chemie 114 sulphate process, titanium dioxide manufacture 74 sulphonyl hydrazide 179 sulphur-based pigments 61-2 Sulzer Chemtech 2 5 0 - 1
Sumitomo Electric Industries 240 surface conditioner 217 surface modification 5 - 6 , 7 , 2 3 , 70,74-6,83 surface quality tests 293 surface segregation functionality 213 surface-glow effect 64 surfactants 3 , 2 2 8 - 9 SurfynolCT-324 229 swelling clays 3 2 - 3 synergism 5 , 8 , 3 1 , 9 5 , 1 0 1 flame retardants 116, 117, 120, 132-5 syntactic structural foam 181-2 synthetic metals (ICPs) 14 7-8
Taheto 129 talc 3 , 7 , 2 1 anti-blocking agents 216 fillers 2 0 , 2 6 - 7 , 3 1 , 8 1 , 1 3 1 , 197 flame retardants 13 0 impact modifiers 191 masterbatches 249 see also magnesium hydroxide TBA Electro Conductive Products 145 TCP/TCF (tricresyl phosphate plasticizer) 170 Tecoplast 242 Tecpril 181-2 Teijin 129 Teknor Apex Plastics 104 TekPearLite 63 temperature control for heat sensitive products 6 5 , 2 7 5 temperatures, low 200, 204, 207, 213 terracotta effect pigments 70 testing 2 79-94 tetrabromobisphenol A 1 1 8 , 1 2 2 , 134 tetrabromophthalic anhydride 122
Editorial Index
tetr amethy I piperidines 109 textile reinforcements 4 7 textiles, flame retardants for 135 Thann and Mulhouse 9 2 thermal black process 84, 86, 89 thermal decomposition processes 8 4 , 8 6 thermal insulation 104, 184, 225-6 thermal testing 282-92 thermo-oxidative instability 31, 84-6,89 thermochromic pigments 6 4 - 5 , 275 Thermolite 9 8 , 1 1 1 - 1 2 thermoplastic microspheres 2 9 - 3 0 thermoplastics glass-reinforced, pigments for 79 mixing 2 4 7 - 5 5 production and consumption 14, 17 reinforcement 3 7 - 8 , 40, 49, 5 1 4,247 thermosets curing and cross-linking 3 , 1 5 1 65 fibre reinforcement 3 8 , 4 0 impact modifiers 197-8 mixing 2 4 6 - 7 thioesters 9 4 , 9 5 , 9 7 Threshold of Regulatory Concern (TRC) 2 7 6 , 2 7 7 Threshold of Toxicological Concern (ToTC) 2 7 6 , 2 7 7 Ti-Pure 83 Ticona 52 tin catalyst 162 in flame retardant 137 in heat stabilizers 94, 97, 98-9, 103,105,106 in UV stabilizers 111-12 Tint-Ayd 71 tinting strength 7 6 - 7 , 8 9 , 1 3 3 , 275 Tinuvin 111
467
TiOna 83 Tioxide 8 3 , 9 2 titanium dioxide 3,14, 6 1 , 7 3 - 8 , 83-4 for coating of pigments 6 3 , 7 0 dispersion 77 extenders 8 0 - 1 grades 76 health and safety 258 manufacturing processes 74 opacity 76-7 particle size 77, 8 2 - 3 properties 81 surface treatments 74-6 tinting strength 76-7 trends 15,92 undertone 77 titanium fibres 4 0 , 1 4 6 titanium-based coupling agents 167-8 Toho Rayon 56 Toray 56 Tospearl 2 1 6 - 1 7 toxicity 2 6 3 , 2 7 3 - 5 from combustion 1 1 6 , 2 6 2 - 3 ; see also flame retardants pigments 5 7 - 8 , 6 9 plasticizers 169, 1 7 0 - 7 1 , 1 7 3 4,258-61,259,264-5 rubbers 233 see also health and safety; legislation Toyota 34 tracer additives 238, 2 4 1 - 4 transmission detectors 2 4 1 - 2 tribromoneopentyl alcohol (TBNPA) 117,122 tribromophenol 122 trichlorethylene 179 trichlorofluoromethane (R 11) 1 7 8 , 1 8 2 , 1 8 3 , 1 8 4 , 186; see a/so CFCs tricresyl phosphate (TCP, TCP) plasticizer 170 triglycidyl isocyanurate ((TGIC) 71 tris-nonylphenyl phosphite (TNPP) 9 6 , 9 7 , 1 0 3
468
Additives for Plastics Handbook
TWI 66 Twintex 46 U Ube Industries 34,222 UHMWPE 48 Ultralex 200 Ultranox 9 6 , 9 7 undertone 77 Unilever 2 77 Uniplex 175 Uniroyal Chemicals 168, 194 Unitika 2 2 5 - 6 Univul 111 urea resins 2 72 urea/formaldehyde curing agent 1 6 0 , 1 6 1 UV absorbers 108,109 UV curing 2 , 1 6 0 , 1 6 2 UV resistance additives 3,204, 213,226 UV resistance of pigments 64, 74, 75,78,83,91 UV screening pigments 108-9 UV stabilizers 3 , 6 7 , 1 0 5 , 1 0 7 - 1 4 , 168 blends 111,112 masterbatches 113-14 in multi-functional pigment systems 67 world market 10 5-6 UV-ChekAM 340 light stabilizer 110-11 Uvasil 114 Uvtec 125
vacuum venting 255 vacuum-forming 157 vanadium 153 Vector SBS 239 Velsicol 18,175 VestowaxP930V 67 Vetrotex Certain Teed 4 6
Victor International 6 3 , 6 5 , 2 2 1 VinnolitVK802 192 vinyl chloride 118 vinyl esters 1 2 2 , 1 6 7 vinyl functional silane 2 5 vinyl products 171, 173-4, 192 viscosity additives 208, 2 4 0 - 1 , 275 vitamin E stabilizers 94, 1 0 2 - 3 , 275 ''Vitamins" 54 Viton FreeFlow 202 void-forming pellets 181-2 volatile organic compounds (VOC) 7 0 , 8 3 , 2 7 0 vulcanizing agents 232
W Wacker Chemie 64, 192, 204, 213, 229 warpage and shrinkage 3, 62, 68, 222 waste 6 2 , 2 4 2 , 2 7 7 - 9 ; see also recycling water treatments 2 waxes for pigment dispersal 6 6 - 7 wear see abrasion and wear weathering-resistant pigments 6 9 70, 74, 79, 108 Werner and Pfleiderer 2 5 0 , 2 5 5 wetting agents 2 0 8 , 2 2 8 Whirlpool 186 white pigments 3, 7, 7 3 - 8 3 , 93; see also titanium dioxide whiteness 1, 2 4 - 6 , 73, 78, 108, 204 Wilax 229 Wilson Color 162 wire and cable applications curing and cross-linking 161, 162-4 flame retardants 129-30, 133, 134,140 heat stabilizers 104 plasticizers 171, 175
Editorial Index
processing aids 211 recycling 240 smoke tests 288 WIZ Chemicals 229 wollastonite 7 , 2 0 , 2 7 , 8 0 - 1 wood effect pigments 6 2 , 7 0 wood flour 2 5 4 , 2 5 5 world market additives 13-18 fibres 55,56 flame retardants 139 heat stabilizers 105-6 pigments 72,92
X-ray marker systems 241-2 Xantrix ADS 13015 UV stabilizer 114 Xtendl9W 214
yellow pigments 70,275
469
61-2,67,68,69,
zeolite 183 zinc hydroxystannate (ZHS) coating for fillers 3 1 , 1 3 1 zinc-based flame retardant 117, 120,124-6,128,132-3 zinc-based heat stabilizers see calcium/zinc stabilizers zinc-based pigments and fillers 78-9,81 zirconia 75 zirconium-based coupling agents 167, 168 Zoltec 5 5 , 5 6 ZytoCal 196
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INDEX OF ADVERTISERS Akzo Nobel Chemicals bv, PO Box 247, 3800 AE Amersfoort, The Netherlands Tel: +31 33 467 67 67Fax: +31 33 467 61 00 OppositePage 1 Baerlocher GmbH, Freisinger Strasse 1, D-8 5 716 Unterschleissheim, Germany Tel: +49 89 14 37 30Fax: +49 89 14 37 33 12 OppositePage 96 APV Baker, Manor Drive, Paston Parkway, Peterborough PE4 7AP, UK Tel:+44 1733 2 8 3 0 0 0 F a x : + 4 4 1733 283004 OppositePage248 Martin Marietta Magnesia Specialties Inc, PO Box 15470, Baltimore, MD, USA 21220-0470 Tel: +1 410 780 5500Fax: +1 410 780 5777 OppositePage 128 Nubiola Pigmentos si. Gran Via de les Corts Catalanes, 648, 08010 Barcelona, Spain Tel: +34 933 435 750Fax: +34 933 435 771 Opposite Page 64
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nubiola i n o r g a n i c
p i g m e n t s
ultramarine blues and violets chrome oxide green anticorrosive pigments synthetic iron oxides micaceous iron oxides zinc ferrite lead chromates and molybdates USA
•
COLOMBIA
•
SPAIN
•
JAPAN
•
INDIA
•
ROMANIA
nubiola pigmentos, s.l. G r a n V i a de les C o r t s C a t a l a n e s , 6 4 8 0 8 0 1 0 B a r c e l o n a -ESPANA / SPAIN T e l : + ( 3 4 ) 933 4 3 5 7 5 0 Fax: + ( 3 4 ) 9 3 3 4 3 5 7 7 1 e-mail:nubiola®nubiola.es - http://www.nubiala.e5
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All in one Baerlocher Additive Systems
TeJ. +1 33 03 6^
BAERLOCHER USA /is Road, NW, P.O. Box 545 Dover • OH 4462*2 - USA 3 0 - F a x + 1 33 03 43 70 25
BAERLOCHER G m b H - Strasse 1 • D-85716 UNTERSCHLEISSHEIM +49 89 14 37 30 • Fax +49 89 14 37 33 12 www.baerlocher.com
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Magnesium Hydroxide for Flame Retardancy and Smoke Suppression Non-halogenated flame retardance with a price-performance advantage! MagShield advantages: • Priced competitively to ATH • Higher thermal process stability than ATH • Non-toxic and Non-corrosive P.O. Box 15470 Baltimore, MD 21220-0470 800-648-7400 or 410-780-5500 FAX: 410-780-5777 www.magspecialties.com e-mail:
[email protected]
Martin Marietta Magnesia Specialties
ISO 9 0 0 2 QUALITY
A
A
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WE HAVE A NAME FOR SOLVING PLASTICS PUZZLES If you've got a plastics extrusion problem that's hard to solve, ^V) the solution is really very easy. Simply talk to us at APV Baker. ^I
With over 30 years experience in plastics compounding extrusion technology, we're renowned for tackling the |i/
issues that other manufacturers would prefer to avoid.
y.^^ To find out more about our expertise and our range of machines call us on +44 (0)1733 283000.
«mAPv The Problem Solvers APV Baker. Manor Drive, irough PE4 7AP .(0)1733 283001
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