No title

Primer 09 | 10

Intelligence… … said William Faulkner, is the ability to cope with environment. Smart coatings not only cope with their environment but go one step further by responding to external influences. What these different influences are and exactly how coatings react is described by Jamil Baghdachi, Eastern Michigan University, in his overview article, which starts on page 17. How functional properties, such as easy-to-clean, have influenced the development of modern coating systems is explained by Dr. Christian Eger, nanoresins AG, and Saulo Franco, Barpimo S.A. (page 14 and 16). Meanwhile, on page 36, it’s all about clean surfaces for Thomas Stingl and his co-authors from Bayer MaterialScience. They present waterborne PURs for formulating virtually VOC-free coatings that boast outstanding cleanability. Dr. Sonja Schulte

There can be no doubt that the increasingly rigorous VOC legislation has driven the development of environmentally friendly systems. Chris Flanagan from IRL sheds light on how it has influenced the decorative paints sector in Western Europe (page 9).

Source: Becker Acroma/Fotolia.com, BASF, Eric Isselée/Fotolia.com

www.european-coatings.com

ECJ_2010_09_A_Primer.indd 3

09 l 2010

European Coatings J OURNAL

3

25.08.2010 13:50:53

Market Watch Industry news Interview Bio-based powder coatings

“Bio-based powder coatings are still in an embryonic phase” Maurizio Crippa, Hexion s.r.l. The demand for eco-friendly coatings is increasing. Maurizio Crippa, Business Director, Powder Resins – EMEA at Hexion s.r.l., speaks about market potentials of bio-based and low temperature cured powder coatings. According to him, there is a growing interest for these types of coatings. _How do you rate the market for bio-based and low temperature cured powder coatings? Do you expect growth in demand for these coatings? Maurizio Crippa: With regard to the biobased powder coatings, this is still in an embryonic phase and would need time to develop, but the use of renewable resources is well perceived by all the coating producers we have interviewed. Instead the low temperature cure concept is of immediate interest, either for energy saving purposes and also to enlarge the powder coating applications to heat sensitive substrates. We expect an increasing demand driven by the need of reducing either the VOC and the CO2 emission. _ Currently, what are the main fields of application for these powder coatings? To what extent do these coatings offer the possibility to open new fields? Crippa: Both technologies give the benefit of reducing energy consumption, so the

target applications are across all segments already covered with conventional powder coatings. However, talking about specific fields which could benefit more from low temperature curing, these are GI (heavy metal) and agricultural equipments. New application areas are a clear goal for all our customers and this can be achieved if obtaining characteristics equal or are even better than what is available today with standard technologies. The next challenge for Hexion will be to provide polymers that enable reaction at temperatures even lower than what is obtainable up to now, with the aim to apply heat-sensitive substrates, such as plastics and wood. _What are trends for bio-based, low temperature cured powder coatings in the future? Crippa: We see a growing interest, at the moment more for low temperature curing than the bio resins, but we believe the growing pressure on crude oil/feedstock prices, plus other factors linked to sustainability, will drive the bio-based materials to be used more and more in the next future. The most immediate target for both technologies is to ensure the application of all paint finishes, such as low gloss and special effects, plus to be in compliance with the existing international standards as Qualicoat and GSB. Without any doubt the possibility to increase the bio-derivate content in a powder coating formulation, together with the target to coat non-metal substrates are one of the most exciting challenges to continue having a bright future for the powder coating industry.  (gag)

Source: Hexion s.r.l.

6

European Coatings J OURNAL

ECJ_2010_09_C_Market Watch.indd 6

09 l 2010

Specific fields which could benefit more from low temperature curing are heavy metal and agricultural equipments

 Resins DIC Performance Resins GmbH optimises product portfolio Japan-based DIC Corporation has agreed to form a constructional joint venture with Spolchemie in the Czech Republic. According to the contract, DIC’s Austrian subsidiary DIC Performance Resins GmbH will transfer its production of alkyd resins to the Czech partner by end of 2010. Through the shift of its alkyd resins production the Austrian specialty resins manufacturer will now focus stronger on acrylic powders, multiple polyoland dispersion technologies for the coatings and adhesives industry. www.dic.co.at

 Investment Rhodia increases surfactants capacity at two sites Rhodia has announced investments at its Halifax (U.K.) and University Park (USA) industrial sites. The company will optimize and increase production capacity and enhance competitiveness at its speciality surfactants sites. In the U.K., the company plans to consolidate surfactants production lines currently at Leeds and Halifax on a single platform to reinforce its long-term competitive position in Europe. The phased transfer of assets from Leeds to Halifax and accompanying investments will generate additional synergies and bring about the critical mass for new growth projects. At the same time, to meet increasing demand in North America, the chemical producer will launch an investment program at the University Park facility to upgrade and increase surfactant production capacities in the region. www.rhodia.com

 Pigments Bodo Möller Chemie and BendaLutz to cooperate Distribution company Bodo Möller Chemie and Austrian pigment manufacturer BendaLutz have signed a cooperation sales contract. Under the agreement the distributor will market primary aluminum pigments of the Austrian company in Sweden, Denmark and Finland through its subsidiaries. www.bm-chemie.de

www.european-coatings.com

25.08.2010 14:01:39

DCM_I

Market Watch Industry news

 Study

Interview Dispersions

"Less competition in the dispersion market" Gerd Hardy, EOC Belgium EOC Belgium's Emulsion Division has signed an agreement to partner with distribution company MT Merk Trading in Switzerland and Liechtenstein. Gerd Hardy, Business Unit Manager EOC Emulsion Division, expects disproportionately high growth in these markets. However, the Belgian company will also keep focusing on other regions in Europe. _Your latest cooperation refers to the markets in Switzerland and Liechtenstein. How do you rate these markets? Gerd Hardy: We are following our strategy, aiming to introduce new products in Switzerland, especially high value applications for printing inks, clear coats and acrylates. The same applies to Liechtenstein of course. During the last years we have grown in Europe annually by 10 %. Therefore, we have high expectations for Switzerland and Liechtenstein. Growth in both markets is expected at a considerably aboveaverage rate i.e. in the triple digit range. _On what other markets will you focus? What developments do you expect? Hardy: A focus remains on our domestic markets in the Benelux countries and France. For these markets we expect moderate growth at 2 to 4 %. In future we will concentrate more on Germany, Austria, Switzerland and Italy. These markets show further growth potential. We aim to expand our presence in England as well. However, this is more difficult. On the one hand because of the Euro and on the other hand, the market there is more driven by price than quality. Our expectations for Eastern Europe are high as well. This market will grow by 5 to 10 %, as the region has only hardly been affected by the crisis. _To what extent will you establish further cooperations in these regions? Hardy: We are looking for smaller partners with extensive knowledge about the re-

8

European Coatings J OURNAL

ECJ_2010_09_C_Market Watch.indd 8

09 l 2010

spective markets instead of companies that do business throughout Europe. _What segments stimulate demand for dispersions? What segments show a downward trend? Hardy: In Eastern Europe the construction industry is the driver. In South Europe it is the wood industry. A lot of solventborne products are still used in both markets. Therefore, we expect growing market shares for our dispersions. In terms of eco-friendly products, demand in the printing inks industry is increasing steadily. We can observe this development for dispersions as well as for adhesives. The downward trend prevails in the segments decorative paints, industry application and sealants. _The economic situation has challenged the coatings industry. How do you act in this environment? Hardy: Innovations are significant tool for retaining existing customers and attracting new customers. Consequently, we will keep investing in our innovative strength. Nowadays supply security is a crucial topic, too. We have invested in a new reactor, which will go on stream in January, increasing our capacity in Europe by 20 %. Additionally, we will increase our capacities in Thailand by 40 %. _What are the trends and challenges in the dispersion market? Hardy: The trend is towards products that are eco-friendly and do not present any health risk. Meeting these requirements will help open up new markets in the future. Furthermore, reducing VOC and odor in coatings and printing inks, for example in the food contact area, is very important. We also expect less competition in the dispersion market in general. (gag)

Market for synthetic latex polymer consumption in Europe to grow The outlook for synthetic latex polymer consumption in Europe remains optimistic despite a negative GDP growth in 2009. This growth for synthetic latex polymer would primarily be driven by applications like printing inks & overprint varnishes, construction and paints & coatings, according to market research firm Kline & Company. From 2010 to 2014 a probable case scenario predicts average growth of 0.9 %. In 2009, the volume of synthetic latex polymers consumed in Europe was in excess of 2.4 million dry tonnes. X-SB is the leading latex with respect to both volume and value, closely followed by pure acrylics and then PVAc. Paper and Paperboard is the leading application in the European market, followed by paints and coatings. The leading five application markets account for 84% of the volume of synthetic latex polymers consumed in Europe. www.klinegroup.com

 Resins Eastman to expand production at two sites

Source: Eastman Chemical Company

Eastman increases production capacity of hydrogenated hydrocarbon resins Eastman Chemical Company has announced plans to expand production of hydrogenated hydrocarbon resins at both its Middelburg, The Netherlands, and Longview, USA, facilities. The Middelburg expansion will increase current capacity by more than 20 %. It is expected to be completed in the second half of 2011. In the USA, the company is planning a capacity increase of greater than 10 %. This expansion is planned for completion in early 2011. The company’s hydrogenated hydrocarbon resins are used as raw materials essential in for example hot-melt and pressure sensitive adhesives. www.eastman.com

www.european-coatings.com

25.08.2010 14:01:42

Market Watch

Source: Sebastian Duda/Fotolia.com

Decorative Paint

Greening of the decorative paint sector in Western Europe Chris Flanagan, IRL The Western European market for paints and coatings was estimated at 6.05 million tonnes in 2009, reflecting a contraction of demand across the construction and industrial coatings sectors across much of Western Europe. The top five leading economies; Germany, Italy, Spain, France and the UK, have all been hit hard by the recessionary period, which has been a major consequence of the global economic crisis rooted in 2008.

A

s investor sentiment falls and unemployment rises, so the decorative paint markets are being tilted more towards growth in the decorative DIY segment, rather than the professional or construction segment. Consumers are currently keen to save money and many are spending on small jobs such as interior

www.european-coatings.com

ECJ_2010_09_D_Market_Watch_Hauptartikel.indd 9

decorating, abstaining from spending on big projects and use of professionals.

Eco-orientation drives the industry A host of factors continue to drive the decorative coatings market. The ever-present aspects of price and quality are still major factors, but more than ever environmental awareness is driving eco-orientation within the industry, while innovation is in high demand by the consumer and the paintmaker alike. Legislation continues to drive decorative paints towards low-, if not totally zeroVOC formulations. This prompted IRL to conduct a survey of the greening of the decorative coatings sector, as part of its most recent ‘Profile of the Western European Paint Industry,’ published in 2009. The background to this survey, entitled ‘The Greening of the Decorative Paint Sector in Western Europe,’ is rooted in the upsurge of information and industry investment in

09 l 2010

* Contact: Chris Flanagan Analyst, IRL T: +44 2088327830 [email protected]

European Coatings J OURNAL

9

25.08.2010 14:04:01

Market Watch Decorative Paint bio-based raw materials and a number of marked trends within the paint industry which have indicated significant strides in the decorative paint sector going green. In mature economies such as those of Western Europe and the USA, increasing pressure is being exerted upon the industry for environmentally-friendly products, not only from legislation but also from corporate and individual customers alike.

Increasing share of VOC paints

Figure 1: Expected share of zero-VOC decorative coatings in 2014 decorative sales by company type

Figure 2: Economical-ecological balance of professional paint consumer according to company type

Figure 3: Economical-ecological balance of DIY paint consumer according to company type

10

European Coatings J OURNAL

ECJ_2010_09_D_Market_Watch_Hauptartikel.indd 10

09 l 2010

The current standing of the industry, based on the varied sample of top paintmakers responding to the survey, is that about 70% of decorative paintmakers in Western Europe produce zero-VOC decorative paints. Of these companies some 51% see zero-VOC paints accounting for between 10 and 50% of their decorative paint sales in their home country, while 21% of them have no, or almost no, sales of zero-VOC paints. The remaining 28% of companies see the majority of their decorative paint sales in zero-VOC types. By 2014, many companies expect to have improved on these positions, particularly with some going for 100% decorative sales being zero-VOC, as shown in Figure 1. However half of the respondent companies have indicated that they only expect between 10-30% of their decorative coatings to be free of VOCs by 2014. Respondents from large multinational paint producers have indicated a varied difference in opinion regarding this with some only expecting to see 10% of their decorative paint products being VOC-free, and others expecting to fully convert their decorative sales to be VOC-free. The companies have been classified according to their size, namely large or small multinationals, regional players or domestic players. This has been defined according to how many different countries each company sells decorative paints in. The target consumers sought by manufacturers of zeroVOC decorative paints are fairly equal across the professional/DIY balance, some companies going purely for DIY consumers and some in pursuit of only professional consumers. Interestingly, professional consumers tend to have the least interest in environmental concerns.

Wide variation: paintmakers' focus on sustainable raw materials With regard to sustainable or renewable raw materials, resins were considered the most interesting prospect by the companies concerned, with 47% of companies thinking they would be a good option. Some 12% of decorative paintmakers have no interest at all in renewable raw materials; for them the emphasis is plainly on quality at the moment. Wide variation is observed in the importance of being seen as a coatings producer working with sustainable raw materials; across a whole range of decorative paint companies, scoring varies from 0/10 to 10/10 in terms of importance. Most, however, consider that the importance of this will increase to some degree in the future. A majority of companies identify interior paints as being the best application prospect for sustainable raw materials. Just 50% think that they would be most suitable for stains, while increasing numbers acknowledge their potential for use in trim paints and wall paints. The greater

www.european-coatings.com

25.08.2010 14:04:03

Market Watch Decorative Paint demands made on exterior coatings of all types render renewable raw materials less useful in that part of the market, in the eyes of the industry. Considering the different approaches to formulating environmentally-friendly decorative paints, efficiency is placed just ahead of sustainability as the leading approach, this therefore disposing the industry towards the use of fewer raw materials but to greater effect. After energy conservation (from the aspect of the paintmaker’s processes in formulation and production), carbon footprint reduction was placed near the bottom of the list and efficacy last - relating to the formulation of coatings with long lifetimes to reduce maintenance and re-application in the future. By far the most attractive target area for the continued greening of decorative paint offerings is the complete elimination of VOCs from decorative coatings (58%) followed by the use of alternative packaging. Over half of the decorative paint companies surveyed were active in environmental education or initiatives aimed at consumers. Of those companies which are not engaged in such measures in 2009, a further 56% consider that they would be likely to embark upon such drives in the future. Some die-hard companies clearly will not. With regard to recycling or reclamation of paint or paint packaging nearly two-thirds of decorative paintmakers are involved in such measures, sometimes internally (their own paint waste) and/or externally (their consumers’ paint (or paint packaging)) waste. A further half of those companies not active in this area plan to become so in the future.

finished. The Olympic focus is on sustainability, with the idea of the London Olympics being the greenest ever, which shows that organisers are very much in tune with the times. Post-2010, the EU decorative paint market will be firmly fixed by the effects of the tightening EU legislation, so the question will be just how eco-friendly any coatings used are – will they be merely zero-VOC rated or will they too be up to the challenges of sustainability by then as well? ‘A Profile of the Western European Paint Industry, 4th Edition’, is available to buy now and contains information on the decorative and selected industrial coatings markets, as well as IRL’s survey on the greening of the decorative paint sector. The cost of the full report (344 pp and 261 tables) is EUR 3,250. More info: www.informationresearch.co.uk

The World’s Most Widely Used Weathering Tester

Balance between economy and ecology When paintmakers were asked about the relative balance between economy and ecology by the professional and DIY consumers in their own countries, 38% of respondent companies see the emphasis by professional painters on absolute economy, with just 11% going as a far as a 50-50 trade-off between economy and the ecology as shown in Figure 2. In the DIY segment however, as seen in Figure 3, the shift is more ecological, with 38% of decorative paintmakers witnessing a 50-50 balance between weighing up cost with ecology, while 12% see their customers putting the environment ahead of costs. This nonetheless still leaves 50% of companies saying that their customers place cost ahead of environmental matters. Despite the recession, the UK paint market could potentially emerge as one of the best growth areas in the next decade, largely due to the arrival of the Olympic Games in London in 2012. This is almost certain to create strong demand for paints and coatings across a host of infrastructure and venue projects in the coming years, and continued demand for paints and coatings as the ongoing redevelopment of parts of East London takes shape once the games are

www.european-coatings.com

ECJ_2010_09_D_Market_Watch_Hauptartikel.indd 11

Accelerate the damaging effects of sunlight, moisture & high temperatures.

• Best simulation of short-wave UV sunlight • Meets world wide test methods • Trusted by customers world wide for 40 years

40 th Anniversary QUV Weathering Tester 1970-2010

Q-Lab, The Most Trusted Name in Weathering Q-Lab Europe Ltd. • [email protected] • www.q-lab.com Q-Lab Deutschland GmbH • [email protected] • www.q-labdeutschland.de

09 l 2010

European Coatings J OURNAL

11

25.08.2010 14:04:03

Associations CEPE

Safety data sheets – more changes and challenges ahead CEPE helps preparing its members by providing an SDS guide Safety data sheets (SDS) are an important element of hazard communication to professional and industrial users of chemical substances and mixtures. Whereas labelling conveys basic information on the dangers of a product, the SDS allows more detailed information to be passed down the supply chain, enabling users to take all necessary measures to ensure the protection of health and safety in the workplace, as required by European legislation. Formal SDS requirements in Europe date from the early 1990s. The Safety Data Sheet Directive 91/155/EEC came into force on 8 June 1991 and was amended twice, in 1993 and 2001. It was finally repealed, along with its transposing legislation in each EU Member State, on 1 June 2007 and replaced by Article 31 and Annex II of REACH (Regulation (EC) No. 1907/2006, published on 30 December 2006). The detailed requirements set out in Annex II were similar to those of the SDS Directive, with the now-familiar 16 sections, but introduced amendments both to accommodate other provisions of REACH and to align with SDS provisions in the UN Globally Harmonised System of classification and labelling (GHS). The most immediate changes were the inversion of sections 2 and 3 and the addition of an e-mail address for the person responsible for the SDS. The practical difficulties of implementing these purely administrative changes in only five months, and of re-issuing every SDS to accommodate them (bearing in mind that some companies issue hundreds or even thousands of different SDS each year), were pointed out by industry and acknowledged by the Commission Working Group on REACH in March 2007. As a result an informal transition period was agreed until 1 December 2010, during which companies were permitted to defer the format update until the first substantial change in the content of the SDS.

Annex II changes reflect CLP deadlines

Janice Robinson, Director Product Regulations, CEPE

12

Even while some companies are still taking advantage of this transitional measure, Annex II is changing. Commission Regulation (EU) No. 453/2010, which was published on 31 May and came into force on 20 June 2010, amends Annex II to align it more closely with the UN GHS and Regulation (EC) No. 1272/2008 on the classification, labelling and packaging of substances and mixtures (CLP). It in fact contains two replacement versions of Annex II, the first effective from 1 December 2010 and the second from 1 June 2015; the two differ only slightly and

European Coatings J OURNAL

ECJ_2010_09_E_Association CEPE.indd 12

09 l 2010

reflect the CLP deadlines for substances and mixtures respectively.

Quite substantial changes The changes introduced by Regulation 453/2010 are quite substantial, but represent an evolution rather than a revolution. For example the 16 sections now include 48 mandatory sub-headings, and a number of physical/ chemical and toxicological properties – previously left to the discretion of the supplier - are now compulsory. If data are unavailable or a property is not applicable, reasons must be given; no blanks are permitted. Suppliers of chemical substances and mixtures, and the software providers on whom they rely to create SDS, face a challenge in implementing these new requirements within only six months. Two factors help to mitigate this impact slightly: »»Draft versions of the regulation have been available throughout its preparation, allowing industry to comment and software developers to begin preliminary programming; »»A two-year grace period is granted for substances already placed on the market, and for mixture SDS which have already been issued at least once, before 1 December 2010. Nonetheless all substance SDS for new shipments, and all new or revised SDS for mixtures, are required to comply with the new format as of 1 December this year. Additional logic and phrases (with of course all the necessary translations) are needed to deliver the new requirements.

SDS Guide: CEPE to publish new edition Draft guidance on the compilation of safety data sheets has been prepared for the European Chemicals Agency (ECHA), but thanks to the moratorium on guidance updates announced by ECHA on 2 June, this will now be published after 1 December 2010 – too late to be useful to those who need to comply immediately. In the meantime some industry associations are filling the gap with guidance tailored to their own membership. Among these is CEPE, which has been publishing an SDS guide for the paint, printing ink and artists’ colours industry since the early 1990s. Its 9th edition, based on the new regulation, will be available to members from late summer onwards to help them prepare for the changes.

www.european-coatings.com

25.08.2010 14:06:00

?

Expert Primer Voices Smart coatings

Be smart and show it Functional coatings are widely spread and highly recommended Developments of resins and additives like minerals are the basic parts for the required functional coatings. The coating becomes smarter with every new additional property, like scratch-resistance for flooring products, Saulo Franco, Barpimo S.A., explains. The co-existence of functionalities is the next step regarding latest developments, Dr. Christian Eger of nanoresins AG says.

“Some genuinely smart developments get lost in the huge world of smart coatings.”

1

How relevant are functional properties, such as easy-to-clean, for the development of new coatings?

2smart What are the current trends in coatings and their raw materials?

Dr. Christian Eger Business Unit Manager Coatings & Electronics Materials nanoresins AG Geesthacht, Germany [email protected]

1

I think functional properties are becoming more and more relevant. Customers today ask for special features of coatings like scratch an abrasion resistance, anti-fogging, anti-fingerprint, soft-touch or easy-to-clean, and they ask for it over the whole lifetime of a product. Examples are parquet, laminate, mobile phones or visors for helmets. These products have to withstand the rigours of daily life, and new ways to introduce functional properties have to be found. It is usually our products wich confer such functionality. By that I mean that customers come to us looking for specific new properties for their own products - in addition to all of the other properties. Our products end up in parquet flooring, furniture coatings, automotive interior and flim coatings that need to be more scratch and abrasion resistant. This property is especially important for film coatings being used for credit cards or identity cars. A topic for the future is avoiding fingerprints on various surfaces such as kitchen worktops and stainless steel. This is one topic of which I believe a proper solution still has to be found. The term “smart coatings” though has become a household word that unfortunately is used indiscriminately and with much hyperbole. As a result, some genuinely smart developments get lost in the huge world of smart coatings

14

European Coatings J OURNAL

09 l 2010

ECJ_2010_09_F_Focus_Expert Voices_mit_Köpfen.indd 14

– such as anti-fogging coatings which, are soft from a chemical point of view, and need to be made scratch-resistant. Our research on new products focuses on developing new binder systems modified with nanosilica, the use of other nanoparticles like ATO (antimony tin oxide) as well as nanosilica modification of bulk engineering plastics.

2vogue.Renewable raw materials are very much in Customers come to us with a raw material, which we modify with nanoparticle to provide more functional properties. In some cases, the raw materials, such as binder systems, are made renewable raw materials. We modify those raw materials with nanoparticles and the formulators then try them out. Another trend consists in imbuing a smart coating not only with one property, but several simultaneously, such as scratch resistance, and antistatic and fungicidal properties. A great challenge is combining thermoforming properties and scratch resistance in one coating: thermoforming is a widely used process that requires some flexible properties of the coating - but customers want it to be more scratch resistant, too. Functional coatings are in great demand in the wide field of film coating, e.g. for laminate or security films.

www.european-coatings.com

25.08.2010 14:08:08

?

Expert Primer Voices Expert voices

“The scratch resistance of smart coatings is also very important.”

Saulo Franco Director R&D Resins Barpimo S.A. Nájera, Spain [email protected]

1

In our case, the resins are crucial to further developments to reach the cleanability. Normally we are focused on the use of the additives to reach certain properties. In some cases with simple modifications of the resins, these properties can be obtained, too. This minimises the use of additives to avoid collateral effects. Additives based on polytetraflurooethylen (PTFE) are very helpful to reach the cleanabiltity, especially for their capacity to change the surface tension and obtain a smooth apperance. We are currently trying to establish whether it is better to incorporate it into the paint or into the resin. The scratch resistance of smart coatings is also very important. If we can’t offer it , our

“Nanomaterials and Surface Engineering” Jamal Takadoum www.wiley.com

16 www.european-coatings.com

02 l 2010

ECJ

products suffer, especially floor coatings. In that event, matt products offer better scratch resistance than their high-gloss counterparts. For high-gloss products, a balance needs to be struck. They must retain their gloss level but cede some scratch resistance because their surfaces are smooth – this is particularly true where there is a high volume of pedestrian traffic. In most cases, it is the type of flooring which matters. Parquet and other floor coatings deteriorate as the years pass, losing gloss by natural degradation. There is therefore scope here for developing improved decorative coatings.

2

The Spanish market is in difficulties at the moment, especially given the decline in construction business. As a result, new technologies are not being adopted so quickly. But of course there is an opportunity to offer new solutions with equilibrium on cost and performance. I believe functional smart coatings will be big here in about 5 to 8 years. Apart from smart coatings, one major trend at the moment is that of renewable raw materials. The entire coatings sector is totally dependent on the petroleum industry. Although we use conventional polyols to make synthetic resins, we are replacing it in our latest developments with vegetable based polyols to improve them even further. This is another way in which developments can be made in smart coatings. Everybody is looking to find substitutes for a specific raw material that operates on the same principle. The question then is one of availability of supply. I think substitutes can be found for 60 – 70 % of raw materials. In general for every new project, we strength to use the maximum percentage of renewable raw material.

09 l 2010

www.european-coatings.com

Source: Plant leaf/Fotolia.com ECJ_2010_09_F_Focus_Expert Voices_mit_Köpfen.indd 16

25.08.2010 14:08:11

Technical Paper

Source: Eric Isselée/Fotolia.com

Smart coatings

Horses for courses The bespoke design of smart coatings

Jamil Baghdachi Smart coatings detect changes in their environment, interact and respond in an appropriate and predictable manner. Today, a range of smart coatings are on the market. Raw materials needed for designing and developing most types of smart coatings already exist in the industry today, although combining them in correct way requires a number of new developments and background knowledge. These novel coatings offer technological capabilities which conventional coatings do not have. Many of the coatings currently under development will find their way into mainstream coatings applications in the not too distant future.

O

ver the past 25 years, coatings technologies have been influenced by the need to lower the level of volatile organic compounds (VOC) as well as to reduce the use of costly, petroleum-based solvents. Therefore, the application of waterborne, powder, UVcurable and high-solids coatings has grown significantly. More recently, initiatives such as green chemistry and sustainability have had a significant impact on the coatings industry. Industrial input into the “green-chemistry”

www.european-coatings.com

ECJ_2010_09_G_Bagdachi.indd 17

movement world wide has led to the development of sustainable chemistry in which products and processes should not only be “green” but recyclable.

Coatings combine several functions A recently published study [1] in Europe defined a research agenda in surface technology based on perceived future research demands in the broad field of industrial coatings. It was found that coatings should combine several functions and/or should be composed of multiple layers in order to satisfy increasingly complex property profiles. The most important, non-traditional functions of desired coatings were defined as follows: »»Easy-clean and self-cleaning properties »»Scratch and mar resistance and generally adjustable tribological properties »»Coatings that enable the recycling of the substrate being treated, such as plastics, by delamination using an external stimulus »»Switchable colour, electrochromy, and electroluminescence »»UV/IR absorption properties

09 l 2010

* Corresponding author: Prof. Jamil Bagdachi Eastern Michigan University, USA T +1 734 487 3193 [email protected]

European Coatings J OURNAL

17

25.08.2010 14:10:25

Technical Paper Smart coatings »»Biological activities such as antifouling and antibacterial processes »»Photovoltaic activity »»Integrated product identity and antenna properties In the past few years, coatings research has taken a new turn. This was in part fuelled by nano-science and nanotechnology. This new direction has also been made possible by the development and availability of new raw materials, innovative particles, polyelectrolytes, liquid crystals, conductive polymers and as nano-structured sol-gel systems. In addition to the availability of these new materials, innovative technologies for the design and formulation of novel coatings have also been developed. Other advances have been in the field of raw material design, including polymers made through atom transfer radical polymerization (ATRP), layer-by layer, self-assembly and novel polymer-bound additives. More recently, there has been growth in research and development and the subsequent generation of commercially available coatings which have “stimuli responsive” properties and functions. These products sense and interact with their environment in addition to having the traditional protection and decorative functions. They are often referred to as “smart coatings”, the definition of which is still being debated. What is clear, however, is that a high-performance coating using certain nano-materials cannot come in this category. More specifically, a smart coating is one which detects changes in its envi-

Results at a glance There has been a recent growth in research and development and commercial product generation of so-called “smart coatings”. These are materials which have “stimuli responsive” properties and functions. European coatings conference Smart coatings 9/10 November 2010, Berlin www.europeancoatings.com/ events

Multifunctional smart coatings exist that sense and interact with environmental conditions such as corrosion, pressure, and temperature. There are protective and decorative coatings that are self-healing that are already commercially available. The raw materials needed for designing and developing most types of smart coatings already exist. They must be combined in the correct way. Smart coatings that change colour with a change in temperature have been developed. Made-to-measure smart coatings that regulate a range of physical properties are available.

Video interviews with Jamil Bagdachi: www.europeancoatings.com/ videos/

18

Reversible, thermochromic and photochromic coatings have wide uses. Unidirectional, stimuli-responsive coatings have been developed for, among others, medical and military applications

European Coatings J OURNAL

ECJ_2010_09_G_Bagdachi.indd 18

09 l 2010

ronment, interacts and responds to them, but nevertheless maintains compositional integrity. The changes to which it may respond include light, pH, biological factors, pressure, temperature, polarity, etc. Hence, a smart coating is tailored in such a way that one or more of the above functions may be “switched on” or “switched off” depending on the type and strength of an external signal. However, not all such materials are capable of switching from one state to another. Antimicrobial, self-healing, and self-stratifying coatings, and so on, are among those whose actions are triggered by certain stimuli. The resulting change is unidirectional. Nevertheless, because of such novel functions, this family of coatings offers significant added value.

Sensing the environment Multifunctional smart coatings exist that sense corrosion, pressure, and temperature [2]. Additionally, protective and decorative coatings that are self-healing are already commercially available. Smart coatings also play a major role in the field of medicine by offering permanent antimicrobial and anti-inflammatory medical devices, including implants and release-on-demand medications. Certain smart coatings can be designed and prepared by using responsive polymers, additive molecules or responsive pigments and dyes or by strategically designing polymer structures and coatings that respond to either internal or external stimuli. In principle, in order to obtain responsiveness, two actions must happen together as well as selectively [3]: »»a stimulus must be initiated and the signal be received by the material »»a chemical or physical process must be induced by this signal In general, two main categories of stimulus exist that can be used to design a smart coating. The physical stimuli can include, light, temperature, electrical field, solubility, acoustic and electromagnetic waves, pH, ionic strength, pressure, electrical and surface-tension gradients. The physical signals are abundant, more tuneable and perhaps less complicated than their chemical counterparts. The chemical stimuli include acid-base, photochemical, electrochemical, redox and biochemical reactions as well as chemical-bond formation and breaking. For example, structural or configurational change or colour change of a simple reversible system containing diazobenzene is limited to cis-trans conformation, whereas, minimal structural change is observed in a silver–containing, antimicrobial coating [3].

Raw materials choice is key The raw materials needed for designing and developing most types of smart coatings already exist in the industry, although combining them in proper way requires a degree of background knowledge and certainly some new developments. To design and formulate a smart coating, in addition to the ordinary design and formulating know how, one of the following ingredients, or a combination of a number of them, is required: Switchable or responsive pigments, responsive additives, and strategically designed and responsive polymers.

www.european-coatings.com

25.08.2010 14:10:25

www.altana.com

Technical Paper

Smart coatings

Our business is

Future

Figure 1: Pigment colour change makes “HOT” becomes visible to indicate bath temperature.

Carbon nanotubes (CNTs) have attracted major interest as a coatings ingredient due to their unique properties [4-5]. CTNs can be used to detect small concentrations of molecules with high responsiveness under ambient conditions. Therefore, they have potential use as chemical sensors in coatings [4-5]. Thermochromic pigments and dyes have been used extensively for decades in many coatings and inks. (Figure 1.) Thermochromism is the ability of a substance to take on another colour with a change in temperature. A mood ring, baby bottles (which change colour when the contents is cool enough to drink) and kettles are examples of this. Thermochromic pigments based on liquid crystals are used in precision applications, as their responses can be engineered to precise temperatures, but their colour range is limited by their operation principles. Along with many other inorganic pigments, montmorillonite clay has been tested for use in self-healing coatings. Indium tin oxide (ITO) has been used in glass coatings in transition lenses. Other inorganic pigments such as zinc oxide, nickel sulphate, mercury (II) iodide and vanadium dioxide are commercially available pigments that revers-

www.european-coatings.com

ECJ_2010_09_G_Bagdachi.indd 19



European Coatings J OURNAL

Shaping the future means having the courage to branch out in new directions. This is precisely the principle that guides all our thinking and actions at ALTANA. Specialty chemicals are our business. A business we pursue with passion and dedication in more than 100 countries. Four specialized divisions work together to ensure that ALTANA‘s unrivalled competence and service excellence continue to improve and expand. With a clear vision of what our customers expect of us, it is our ambition at all times to develop solutions that turn opportunities into future reality.

19

25.08.2010 14:10:27

Technical Paper Smart coatings ibly change colour as a function of temperature. Vanadium dioxide has been used as window coating to block infrared transmission and reduce the loss of the interior heat of a building through its windows. In addition, silver in both the powder, encapsulated or and nano forms and various types of titanium dioxide have been used in unidirectional, antimicrobial smart coatings.

Dyes change colour with temperature

Figure 2: Schematic representation of a solvent-initiated morphology change.

Figure 3: Representative chemical structures of acid and base functional polymers.

Leuco dyes allow wider range of colours to be used, but their response temperatures are more difficult to set with accuracy. The most commonly used temperatureresponsive dyes are spirolactones, fluorans, and spiropyrans. While they may not be considered as coatings, the interesting application of leuco dyes is in the Duracell battery that indicates the amount of charge left in the battery. A survey of the recent literature indicates that smart coatings based solely on the responsive polymers are derived from proprietary and captioned technologies, examples of which are polymers such as inherently antimicrobial, drug delivery, self-healing, shape-memory and super hydrophobic/hydrophilic materials. The most studied and used polymers include N-isopropylacrylamide (NIPAM), N,N-diethylacrylamide (DEAAM) poly(Nvinylcaprolactam) (PVCL), poly(ethylene glycol), (PEG) or poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO). These materials and their derivatives are available commercially from laboratory chemical suppliers. Furthermore, many custom-made supramolecules (dendrimers, hyperbranched molecules) and hydrogels are routinely used in drug delivery systems that can be used in smart coatings. In addition, certain polymeric materials containing quaternary salts and derivatives of halamine as well as small molecules have been traditionally employed as antimicrobial agents in many coatings.

Made-to-measure design The modification of surfaces by chemical and physical means to regulate properties such as adhesion, adsorption and wettability is a well-known and widely used approach [6]. The ability to reversibly switch the properties of a solid surface from being strongly hydrophobic to strongly hydrophilic can be achieved by grafting various polymers onto polymeric and non-polymeric solid materials [7]. A schematic representation of surface modification and its response to solvent-initiated morphology is shown in Figure 2. The well-known pH indicator phenolphthalein changes from colourless to red as the pH rises. This phenomenon has been applied in the detection of the corrosion of aluminium [8]. Examples of acid and base functional polyCmers are shown in Figure 3.

Figure 4: Schematic representation of switching behaviour of mixed PE brush upon change of pH: below isoelectric point (A) and above the isoelectric point(B).

20

European Coatings J OURNAL

ECJ_2010_09_G_Bagdachi.indd 20

09 l 2010

Switching properties in response to pH Acid-based reactions that respond to pH variations have also been used to demonstrate switching behaviour of

www.european-coatings.com

25.08.2010 14:10:29

Technical Paper Smart coatings

Figure 5: Schematic representation of self-healing sequences in a polymeric coating. brush-like polymers (Figure 4). Polyacrylic acid (PAA) and poly(2-vinylpyridine) (P2VP) polyelectrolyte brushes were grafted to a silicone wafer [9]. At high and low

pH values, µ, the top of the sample is occupied by hydrophilic protonated P2VP and dissociated PAA respectively and therefore, the brush remains hydrophilic in the

"European Coatings Handbook" Brock, Groetklaes, Mischke www.europeancoatings.com/books

When you formulate with Mowilith®…

the only thing she smells is her coffee. Mowilith VAE emulsions for low odour paints

When you formulate low odour, interior coatings with Mowilith VAE emulsions, VOCs and odour don’t interfere with the homeowner’s ability to enjoy everyday pleasures, like the rich aroma of freshly-brewed coffee. Painters will also love your eco-friendly paints because they are easy to apply and durable. For more than a decade, Celanese has been a leader in the development of emulsions for eco-friendly paints. Let us put our technology and experience to work for you.

Your future is our focus…worldwide.

Check out the latest in low odour technology for paints today. Contact us: +49 (0) 69 305 2876 [email protected]

www.Celanese-Emulsions.com www.european-coatings.com

formulate. ECJ_2010_09_G_Bagdachi.indd 21

09 l 2010

manufacture.

market.

European Coatings J OURNAL

paint.

21

live 25.08.2010 14:10:30

Technical Paper Smart coatings

Figure 6: Microcapsule with healing agent (a), release of healing agent on exposure to high humidity and high temperatures (b), embedded microcapsules in coating medium (c)

www.ecc.com "infos und tips" [email protected]

22

entire range of pH except in the neutral region, where a compensation of the charges takes place. At a pH 2, PAA brush is hydrophobic with a contact angle of 70° whereas at pH 10, it behaves hydrophilic with a contact angle of about 20° while a P2VP brush demonstrates an opposite behaviour. The responsive behaviour of such systems is of potential interest for drug delivery systems and smart nano-devices. The use of organic and inorganic thermochromic pigments and polymers offers a convenient way of designing smart coatings. Certain conjugated polymers and cholesteric liquid crystalline polymers are well-established classes of single-component polymers that exhibit thermochromic properties. In some liquid crystalline polymers, the annealing of the photo-oriented films above the glass-transition temperature within the mesophase results in a strong amplification of the optical anisotropy under special circumstances. Reversible thermochromic materials are widely used as safety devices. High-temperature, reversible indicators give a visible sign that a surface is hot. They are used on automobile radiator caps and fire-resistant doors to prevent burns. In addition to industrial applications, the technology has been applied to kitchenware in the form of saucepan handles which turn red when they reac about 45°C. Photochromic coatings which darken reversibly on exposure to light have already found commercial applications. They are mostly based on organic photochromic materials such as spirooxazine, and pyrans, incorporated into organic polymeric or inorganic composites by a sol-gel process. These coatings with response times of about few seconds are applied onto transparent substrates (glass, polymers) or on non-transparent substrates (ceramics, polymers, paper) with dry film thicknesses in the range of 5-50 µm. Smart window-coating materials are characterized by their ability to adjust to light transmission upon application of an electrical potential. Materials used for this purpose include suspended particles, liquid crystals and electrochromics [10]. Work on unidirectional, stimuli-responsive coatings has also produced commercially available coatings. Antimicrobial and anti-inflammatory coatings are being used on medical devices (drug eluting), military clothing and on household appliances and hospital equipment. Self-

European Coatings J OURNAL

ECJ_2010_09_G_Bagdachi.indd 22

09 l 2010

healing, corrosion sensing, radio frequency identification and intumescent coatings, as well as self-erasing inks, are examples other unidirectional responsive coatings.

Act on demand coatings Structural polymeric materials have been developed that possess the ability to self-heal. They are inspired by biological systems such as cells and bones in which damage triggers restructuring, reshaping, rebuilding and healing. In one approach, microencapsulated healing agents and chemical catalysts are dispersed in an epoxy coating layer [11-14]. When damage occurs in the polymer, a crack propagates through the matrix and thus rupturs the microcapsules in the crack path. The ruptured microcapsules release the healing agent which is then drawn into the crack through capillary action. Once the healing agent within the crack plane comes into contact with the embedded catalyst, a chemical reaction is triggered and polymerization of the healing agent occurs. Another approach [15], takes advantage of ordinary everyday stimuli in the environment. Most coatings are exposed to natural phenomena such as water in the atmosphere, various forms of electromagnetic radiation and a wide range of temperatures. The natural process of mechanical, hygrothermal fatigue and chemical attack degrade a coating matrix and initiate micro cracks within it. Propagation of micro cracks may result in fracture, loss of barrier properties, delamination and coating failure. Coating degradation upon exposure to atmospheric elements and subsequent self-healing is demonstrated schematically in Figure 5. Microencapsulated healing agents are dispersed in the coating medium. The capsules are designed to rupture upon exposure to harsh and abusive conditions such as high temperature, humidity and mechanical forces, thus releasing the healing agent. The reactants are then drawn into the crack through capillary action. Chemical reactions between healing agents take place. This triggers on-site polymerization and the healing of the damaged area. The SEM images of encapsulated healing agents and the cross section of coating containing healing agents are shown in Figure 6. The healing of the coating is demonstrated by comparing the stress-strain behaviour of exposed and unexposed samples

www.european-coatings.com

25.08.2010 14:10:31

Technical Paper Smart coatings

Figure 7: Control without healing agent (A), -Control unexposed, -- Control exposed at 75% RH, 45°C; sample with healing agent (B), -- SH-unexposed, -- SH-exposed. of it. As can be seen from the dynamic mechanical analysis curves in Figure 7, the sample containing self-healing agents responds favourably to exposure conditions by an increase in modulus, while the control (without healing agent) is apparently plasticized by exposure to water and high temperatures.

Refereces

Think Global. Paint Local.

[1] U  hlman P., Frenzel R., Voit B., Mock U., Szyska B., Schmidt B., Ondratschek D., Gochaermann J., Roths K., “Research Agenda Surface Technology: Future Demands for Research in the Field of Coatings Materials”. Prog. Org. Coat. 2007, 122-126. [2] Shen Y., et al, Polymer Preprints 2002, 43(1) 69-70.

Dow Microbial Control is ready to help preserve your in-can paint, protect your dry-film applications and improve your plant hygiene.

[3] Laschewsky A., Lotsch D., Seeboth A., Storsberg J., Stumpe J. Smart Coatings III 2004 European Coatings, Vincentz. [4] Wildoer J.W., Venema L. C., Rinzler A.G., Smalley R.E.,

We offer the broadest line of antimicrobial products available, including many cost-effective BDP-supported options. Plus, our Customer Application Center in Singapore provides the best in region-specific technical, regulatory and market support.

and Dekker C., Nature, 1998, 391, 59, [5] Jung H. Y., Jung S. M., Kim J., Suh J.S., Appl. Phys. Letters, 2007, 90, 153114. [6] Minko S., Motornov M., Eichhorn K., Nitschke M., Simon F., Stamm M., Langmuir 2003, 19, 8077-8085. [7] Minko S., Müller M., Motornov M., Nitschke M.,

Paint a bright future for your products—and your reputation.

Grundke K., Stamm, M., J.Am. Chem. Soc. 2003, 125, 3896-3900. [8] Minko S., Motornov M., Eichhorn K., Nitschke M., Si-

Ask More of Us. www.dowmicrobialcontrol.com

mon M., Stamm, M., Langmuir, 2003, 19, 8077-8085. [9] Zhang J. G., Fenkel J., paper presented at the Material research Society meeting, Boston, 1997. [10] Xu C., Liu L., Legenski S., Ning D., Taya M., J. Mater. Res., 2004, 19(7), 2072.

Celso Magri Ask Us Expert Dow Microbial Control

[11] S anterre J.P., Labow R.S., Duguay DG, Erfle D, Adams GA. J. Biomed. Mater Res 1994, 28, 1187-1199. [12] White S. R., Sottos N. R., Geubelle P.H., Moore J.S., Kessler M.R., Sriram S. R., Brown E. N., and Viswanathan S., Nature. 2001, 409, 794. [13] Brown E. N., Sottos N. R., White S. R., Experimental Mechanics , 2002, 42, 372. [14] K  essler M. R., Sottos N. R., White S. R., Composites

Ask a local expert. +603 7958 3392

www.dowmicrobialcontrol.com

Part A., 2003, 34, 743. [15] Baghdachi J., Unpublished results.

www.european-coatings.com

09 l 2010

ECJ_2010_09_G_Bagdachi.indd 23

European Coatings J OURNAL

23

25.08.2010 14:10:31 DMC Paint&Coat 2010 SEANZ ACPJ Sep10 ISL.indd 1

C

Technical Paper Plastic coatings

Locked up for protection Non-migrating light stabilisers enhance coating performance on plastics

* Corresponding author: Dr. Christian Schaller BASF SE T +49 621 60 48952 christian.schaller@ basf.com

Christian Schaller* Adalbert Braig Coatings for plastic automotive components must not only match the steel body in colour and appearance, but also achieve the same durability. A major challenge has been that light stabilisers may migrate from the coatings into the plastic substrate, accelerating coating degradation. Non-migrating HALS can greatly improve performance, while some migrateable types degrade certain substrates.

L

ight stabilisation of coatings has been a challenge for the industry for a long time [1]. To ensure the durability of coatings and to protect their decorative and protective characteristics it has been common practice to combine UV absorbers (UVA) with hindered amine light stabilisers (HALS). The role of the UVA is to filter out the harmful wavelengths of the light spectrum and to prevent photochemical reactions that lead to degradation of the coating and consequently of the substrate [2]. HALS compounds effectively scavenge free radicals at the coating surface where protection by the UVA is least, retard the photo-oxidative degradation of polymers (i.e. both coatings and plastics) and thus help to prevent surface degradation [3]. The application of UVA and HALS for coatings over impermeable substrates such as steel can be considered as being state-of-the-art and fully understood. However, there is still a knowledge gap and some need for special consideration when using light stabilisers for coatings on plastic substrates.

How substrate properties affect coating degradation Historically, coatings on plastic have not been able to achieve the same weatherability as coatings on steel. Examples of inadequate coating performance on plastic car body parts are shown in Figure 1. Here, delamination

of the clear coat (CC) on a side mirror (Figure 1a) and a rear spoiler (Figure 1b) has taken place, whereas the coatings on the steel car body remain fully intact. Figure 1c shows a headlamp which turned turbid due to insufficient protection of the coating. These durability problems may result from the coating on the flexible plastic having a different composition from that on the rigid steel. They may also be caused by migration of low molecular weight components from the plastic into the coating, as well as migration of light stabilisers from the coating into the plastic [4]. The migration of light stabilisers from the coating into the underlying plastic substrate results in a depletion of the stabiliser in the CC, producing a significant reduction in durability of the coatings. One solution to the migration problem is modification of the light stabiliser structure to include a functional group that can react into the coating. However, until recently the need for reactable stabilisers has been comparatively small for conventional automotive basecoat/clearcoat (BC/CC) systems. In coatings applied on steel, reactability shows little visible advantage. With the increased use of coated plastic for automotive exterior body parts, however, the need for reactive and therefore non-migrating light stabilisers is increasing.

Factors affecting choice of light stabilisers For conventional solventborne (SB) clearcoat technology, a variety of UVA and HALS light stabilisers are available. The best performing UVA for 2K-PUR systems is based on hydroxyphenyl-s-triazine (HPT) technology. HPT is known for its superior photostability along with excellent thermal and migration stability (see structure in Figure  2)  [2]. For coating applications, the most important HALS types are difunctional piperidine derivatives linked by diesters or triazine rings as also shown in Figure 2 (generally referred to as HALS 1, 2 and 3).

D

U Figure 1: Examples of inadequate coating performance on plastic car body parts: side mirror (1a), rear spoiler (1b) and head lamp (1c)

24

European Coatings J OURNAL

ECJ_2010_09_Ha_Schaller.indd 24

09 l 2010

www.european-coatings.com

25.08.2010 14:17:09

Technical Paper Plastic coatings

Figure 2: Chemical structures of hindered amine light stabilisers (HALS) and hydroxyphenyl-s-triazine (HPT) UV absorber (UVA) HALS-1 is a basic multipurpose product for 2K-PUR coatings applied over metal, which exhibits excellent longterm stability and solubility in most paint systems. The non-basic aminoether (NOR) HALS-2 gained wide acceptance in the paint industry for application where HALS-1 cannot be used due to its basicity [5]. Basic HALS can, for example, interfere with the catalysts used in acid-cata-

Results at a glance The use of plastics for structural automotive components has significantly increased in recent years. Coatings for these plastic components must not only match the steel body in colour and appearance, but also meet the same durability criteria. A major challenge with coated plastics in exterior use has been the tendency of light stabilisers to migrate from the coatings into the plastic substrate. Test results confirm that this migration can lead to a substantial loss of HALS from the coating, which reduces weathering resistance. HALS-3, which bonds into the coating, greatly reduces this loss and allows similar durability to be achieved over both steel and plastics. "Automotive Paints and Coatings" H.-J. Streitberger/ K.-F. Dosssel www.wiley.com

26

In addition, some HALS are alkaline. Their basicity can cause problems with the curing reactions of some coatings, and accelerate the degradation of certain plastics, including polycarbonate.

European Coatings J OURNAL

ECJ_2010_09_Ha_Schaller.indd 26

09 l 2010

lysed or air-drying systems such as alkyds or oil based paints [3]. The NOR HALS-3 has in addition a reactable primary hydroxyl (OH) functionality (see Figure 2). The OH group can react with melamine and isocyanate crosslinkers, resulting in chemical bonding to the polymer matrix which in turn improves compatibility and resistance to migration out from coatings on plastics and other permeable substrates [4]. Some analytical data and weathering results for conventional SB coatings on plastic substrates are presented below. In particular, the migration behaviour of both non-reactable and reactable HALS in 2K-PUR coatings applied on different plastic and steel substrates is discussed, along with effect of the light protection on long-term performance. The examples shown clearly indicate that a careful selection of light stabilisers is the key to optimal coating performance on plastics.

Test procedures summarised The types of HALS and UVA tested are summarised in Table 1 (corresponding to the structures in Figure 2). The coating systems for different application tests were conventional SB 2K-PUR CC and SB or waterborne (WB) basecoats (BC). The substrates for evaluation were commercially available thermoplastic olefin (TPO), acrylonitrile butadiene-styrene (ABS) or polycarbonate (PC) substrates. The HALS oxidation technique was used to quantify the HALS concentration in both the coatings and the substrate [4]. For the concentration versus depth profiles, the samples were microtomed, and the HALS level in the individual microtomed layers was quantified.

www.european-coatings.com

25.08.2010 14:17:09

Technical Paper Plastic coatings Artificial weathering studies were performed according to SAE J1960 and DIN EN ISO 11341 A (also referred to below as the Xe-WOM CAM 7 cycle) using an Atlas “Weather-Ometer Ci-65 A”. The gloss evaluation was performed at 20 ° according to DIN 67530. Cracking evaluation was performed visually according to crack formation scale 353 from TNO. Crosshatch values were determined in accordance with DIN 53151 and ASTM D3359.

Migration reduces weathering resistance over plastic The migration behaviour of the reactable and non-reactable HALS from the coating into the substrate was first considered. Figure 3 shows a concentration versus depth profile for HALS-2 and HALS-3 in combination with HPT as UV absorber in an SB 2K-PUR BC/CC system on TPO after 3000 hours SAE J1960 exposure. Both CC and BC were stabilised with 2.7 % HPT + 1 % HALS. After weathering, the non-reactive HALS-2 can be detected at least as far as 250 μm deep inside the TPO substrate. In comparison, the reactive HALS-3 remains fully in the CC and BC but is not present in the TPO. The depletion of the HALS in the coating accounts for a significantly inferior durability of coatings applied over

www.european-coatings.com

ECJ_2010_09_Ha_Schaller.indd 27

Figure 3: Concentration versus depth profile for HALS-2 and HALS-3 in SB 2K-PUR CC/BC system stabilised with 2.7 % HPT + 1 % HALS on TPO substrate after 3000 hours SAE J1960 exposure

09 l 2010

European Coatings J OURNAL

27

25.08.2010 14:17:12

Technical Paper Plastic coatings Table 1: UV absorber (UVA) and types of hindered amine light stabilisers (HALS) tested Light stabiliser

Description

CAS name

HALS-1

basic HALS

bis/mono (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate

HALS-2

non-basic HALS

bis (2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl)ester

HALS-3

non-basic reactable HALS

2,4-bis [N-Butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) amino]-6-(2-hydroxyethylamine)-1,3,5-triazine

HPT

UVA

2-[4-[(2-Hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4dimethylphenyl)-1,3,5-triazine

plastic compared to steel. This reduced performance, i.e. the loss in protection against surface defects such as loss of gloss, is clearly demonstrated in Figures 4 and 5. Figure 4 shows the 20 ° gloss retention of the system described above. HALS-3 shows essentially the same gloss retention both over steel and plastic substrates,

Table 2: Crosshatch resistance of 2K-PUR CC over silver metallic BC on PC after 6800 h Xe-WOM CAM 7 exposure Light stabiliser, 1.5 % HPT-1 plus:

Crosshatch according to: DIN 53151

ASTM D3359

No HALS

1

4

1.0 % HALS-1

4

1

1.0 % HALS-2

0

5

1.0 % HALS-3

0

5

whereas HALS-2 shows clearly inferior performance when applied over TPO. This can be explained by the tendency of HALS-2 to migrate, which leads to its depletion in the topcoat, and subsequently to reduced prevention of surface defects. Over impermeable substrates, reactability and/or migration resistance cannot be considered to be decisive factors affecting long term performance. This example therefore clearly shows that a proper light stabiliser combination can significantly influence the overall performance of a coating system. Figure 5 shows a similar performance pattern for nonreactable HALS-1/2 and reactable HALS-3 in a 2K-PUR over a silver metallic BC on ABS during Xe-WOM CAM 7 exposure. Without light stabiliser or with HPT alone there is severe loss of gloss even after 1000 h and cracking after 1250 h exposure because of the absence of any protection from surface defects. With the migrating basic HALS-1 the performance is improved to 1600 h to reach 50 % gloss loss. The migrating non-basic HALS-2 achieves 1800 h and the best performance (2200 h) is obtained using the non-migrating nonbasic HALS-3.

HALS migration can also cause substrate degradation

Figure 4: 20 ° gloss retention of SB 2K-PUR stabilised with 2.7 % HPT + 1 % HALS over BC on TPO and a steel substrate during SAE J1960 exposure

28

European Coatings J OURNAL

ECJ_2010_09_Ha_Schaller.indd 28

09 l 2010

These examples clearly demonstrate that the choice of a HALS that is inadequate because of its migration does not significantly improve the overall long term performance of the coating. In both examples, however, the migrating HALS does not interact or interfere with the plastic substrate. However, migration of basic HALS can cause severe problems if the plastic substrate is sensitive to basic components. Such a situation exists for polycarbonate (PC), a plastic widely used for lighting (headlamps) and glazing. Here it is well known that the presence of any basic material, including that due to migration of basic HALS into the PC matrix, can cause hydrolysis reactions when it is exposed to light, elevated temperature and humidity. This hydrolysis can ultimately cause cracking or delamination of the coating layers from the substrate [6]. Figure 6 shows a headlamp based on PC coated with SB CC containing a basic HALS-1 after two years in the field. In this example it was evident and confirmed by analytical

www.european-coatings.com

25.08.2010 14:17:12

Technical Paper Plastic coatings investigation that the basic HALS-1 caused hydrolysis reactions at the PC/coating interface and this finally caused cracking of the coating. Another example of different HALS in coatings on PC and the influence of HALS basicity on coating adhesion is shown in Table 2. Here the crosshatch values according to DIN 53151 and ASTM D3359 of a 2K-PUR CC stabilised with 1.5 % HPT and 1 % HALS over a silver metallic BC on PC after 6800 h Xe-WOM CAM 7 exposure are shown. Based on the crosshatch values, it can be seen that without HALS and with 1.5 % HPT UVA alone the adhesion is only slightly reduced (crosshatch values 1 and 4). In the presence of the basic HALS-1, however, severe adhesion problems with delamination after crosshatch are found (4 and 1) indicating migration with hydrolysis at the coating plastic interface. Both the non-basic HALS-2 and 3 in the presence of UVA show perfect adhesion with crosshatch values of 0 and 5 respectively. It can therefore be stated that HPT combined with HALS-2 or 3 are the products of choice for coatings over polycarbonate parts which are exposed to weathering. However, it has already been shown that the non-migrating HALS species outperform others in terms of long-term protection effects against surface defects.

Coatings on plastics can match performance on metals These examples clearly demonstrate that the right choice of UVA and HALS light stabilisers are keys to ensure optimal long-term performance of coated plastic parts exposed to weathering. Here the following statements can be made: » very little migration of stabilisers from topcoat to substrate occurs during initial cure; » migration of light stabilisers occurs predominantly during subsequent exposure; » there is a direct relationship between weathering performance and the extent of migration of the stabilisers from the topcoat; » for polycarbonates, only non-basic HALS can be used.

Figure 6: Severe cracking of polycarbonate-based headlamp coated with SB CC containing basic HALS-1 after two years in the field The recommended light stabiliser package for exterior coatings over plastics for high-performance applications such as automotive coatings thus consists of the hydroxyl-phenyl-s-triazine based HPT UVA in combination with the non-basic and non-migrating HALS-3. This light stabiliser combination exhibits excellent long term performance along with the highest photopermanence, thermal and migration stability to match the performance of coatings over impermeable substrates. With these optimised light stabiliser combinations it is possible to close the performance gap between coatings on steel car body parts and attached plastic parts.

REFERENCES [1] Valet A., Light Stabilizers for Paints, ISBN 3-87870-443-7, C. R. Vincentz Verlag, Hanover, Germany, 1997, pp 45-128. [2] Schaller C., Rogez D., Braig A., Hydroxyphenyl-s-triazines: advanced multi-purpose UV-absorbers for coatings, Jnl. Coat. Tech. Res., 2008, Vol 5(1), pp 25-31. [3] Schaller C., Synergy in the sunlight, Europ. Coat. Jnl., 2010, No 1, pp 28-32. [4] Cliff N., Adamson K., Kanouni M., Yaneff P., Migration of reactable UVA and HALS in automotive plastic coatings, Jnl. Coat. Tech. Res., 2004, Vol 1(3), pp 201-212. [5] Schaller C., Rogez D., Braig A., Hindered amine light stabilizers in pigmented coatings, Jnl. Coat. Tech. Res., 2008, Vol 6(1), pp 81-88.

Figure 5: 20 ° gloss retention of 2K-PUR stabilised with 0.6 % HPT + 0.6 % HALS over silver BC on ABS during SAE J1960 exposure

www.european-coatings.com

ECJ_2010_09_Ha_Schaller.indd 29

[6] Gaines, G. L., Acceleration of hydrolysis of bisphenol-A polycarbonate by hindered amines, Polymer Degradation Stability, 1989, Vol

European Coatings Symposium "Modern coatings for plastics" 29 October, 2010, Düsseldorf, Germany www.europeancoatings.com/ events/

27, pp 13-18.

09 l 2010

European Coatings J OURNAL

29

25.08.2010 14:17:14

Technical Paper Functional fillers

Benefits extended Opaque polymer can be used in both solvent- and waterbased coatings

Alain Garzon Dow Coating Materials T +33 493 95 53 68 [email protected]

Alain Garzon An opaque hollow sphere polymer has been synthesised for use in architectural solventborne alkyd paints. It can help to cut costs by allowing TiO2 usage to be reduced while maintaining opacity. As the polymer is supplied as a dispersion in water it reduces VOC levels, and it can also replace existing opaque polymers in waterborne paints.

T

he general economic environment, combined with tight raw material supplies in the paint industry, has encouraged producers to look for cost-effective alternative raw materials that will provide similar performance in their formulations. In the case of white and light shades, the two main contributors to cost in a paint formulation are evidently the binder and the TiO2 pigment. A well-established industry practice to reduce their usage levels in waterborne

Figure 1: Typical effects of reducing TiO2 content on the contrast ratio of a paint

Figure 2: Scattering (blue) varies linearly with film thickness, unlike contrast ratio (red)

30

European Coatings J OURNAL

ECJ_2010_09_Hb_Garzon.indd 30

09 l 2010

paints, without compromising quality, is to add opaque polymers (OP). This hollow sphere technology has become a standard raw material for many formulators, allowing overall cost reduction in formulations. Associated benefits include lowering of the density of the final formulation, a lower carbon footprint which implies sustainability benefits, and easy handling and incorporation due to the liquid form of this extender. Performance-related benefits in the applied coatings can include enhanced whiteness and tint retention, improved dirt pick-up, scrub resistance and cracking resistance in exterior applications.

Reversing the trend: from waterborne to solventborne For many years, OP technology was only usable in waterborne paints. However, recent advances in material design mean that this technology is now also available for the formulation of architectural solventborne alkyd paints. This more recent OP formulation is also delivered in water, but is designed to resist solvents commonly used in paints. It not only permits a reduction in the TiO2 content for alkyd-based systems, but it also contributes, through water inclusion, to VOC reduction. The performance benefits offered by opaque polymers in waterbased systems also apply to this material. Moreover, the same new material can be used in waterbased formulations, which will allow formulators less complexity in their materials management when purchasing OP for both alkydand waterbased systems.

Scattering provides best measure of opacity benefits Reducing the TiO2 content in a solventborne paint formulation naturally reduces the hiding performance. Figure 1 shows the impact on hiding performance of an incremental reduction of the PVC of TiO2 in a paint formulation. The experiment was conducted at constant total PVC by adjusting the extender PVC accordingly. Measurements were made using the Contrast Ratio method. It can be seen that below 90-85 % of the initial TiO2 level the contrast ratio is dramatically reduced. The contrast ratio method of measuring hiding performance is easy to perform and is widely used by paint formulators when developing and testing their paint formulations. However, this method can be very sensitive to the applied paint film thickness, and small variations in thickness can induce significant differences in results. This is particularly true at low film thickness. This method of opacity measurement integrates both light scattering and light absorption. In order to obtain a more precise idea of the contribution of OP to hiding performance, the measurement of scattering power is preferable. This can be calculated

www.european-coatings.com

25.08.2010 14:19:50

Technical Paper Functional fillers from the Kubelka-Munck equation, which includes both S (scattering) and K (absorption) coefficients. The scattering method has the advantage of being more accurate than the contrast ratio method and, unlike the latter, varies linearly with film thickness as shown in Figure 2. The introduction of opaque polymer for solventborne alkyds (OPSB) can help to compensate for the loss of hiding or opacity resulting from the TiO2 reduction. Depending on the amount of OPSB added, the hiding performance can vary significantly as illustrated in Figure 3. The results obtained by the scattering and contrast ratio methods are consistent with each other, but the former gives the formulator the true contributions of TiO2 and OPSB to opacity performance in their formulations. As with waterborne systems, attention to the manner in which the alkyd-compatible OP is formulated is needed in order to optimise matching of the opacity and control of the viscosity.

Basic reformulation procedure summarised Opacity performance matching can be achieved through a protocol based on the experience developed with the reformulation of aqueous-based systems with high quality opaque polymers for waterborne paint (OPWB). Typically, the original TiO2 PVC content is reduced by a factor of 15 % to 20 %. Each “unit” of PVC removed is then replaced by 3 to 4 PVC units of OP. The total PVC is then raised by 3-5 units by adjusting the extender PVC.

Results at a glance Improvements in hollow sphere polymer technology have created an opaque polymer which can be formulated into architectural solventborne alkyd paints. It has sufficient resistance to the solvents normally used in these formulations to retain its particle integrity. The use of this opaque polymer can allow a significant reduction in TiO2 usage while maintaining opacity, and can help reduce formulation costs. As the polymer is supplied as a dispersion in water, it also contributes to the reduction of VOC emissions by including water in the alkyd paint. It appears possible to control any consequent increase in viscosity by adjusting the thickener levels. This opaque polymer can also replace existing opaque polymers in waterborne paints, thus avoiding any need to increase the number of raw materials stocked.

www.european-coatings.com

ECJ_2010_09_Hb_Garzon.indd 31

09 l 2010

European Coatings J OURNAL

31

25.08.2010 14:19:55

Technical Paper Functional fillers Table 1: Reformulation of a white paint to reduce TiO2 content but retain opacity Raw materials

Reference paint

Reformulation

Weight %

PVC %

Weight %

PVC %

TiO2

32.7

22.0

28.7

18.2

Extenders

22.5

22.0

15.5

14.4

OPSB

0

0

11.7

14.8

Total PVC

44.0

47.4

Scattering

5.2

5.6

Contrast ratio

96.3

96.6

Table 1 illustrates the reformulation of a solventborne alkyd paint to which this protocol has been applied.The opacity measurements, taken by both the contrast ratio and scattering methods, show that the opaque polymer advantageously contributes to the replacement of TiO2 in the formulation thanks to its inherent light scattering property. The light scattering efficiency of opaque polymers depends mainly on two factors: » uniform distribution in the paint film; » optimised size of the inner void space. Figure 4 shows an ideal dispersion of opaque polymer, where there is a visibly good distribution of the polymer voids throughout a dry solventborne alkyd paint film. If it is not well dispersed, its efficiency is distinctly lowered leading to poor opacity. It is therefore recommended to add the OPSB at high shear to ensure proper dispersion.

Viscosity must be checked when reformulating

Figure 3: Contrast ratio and scattering values correlate

The addition of water to solventborne alkyd formulations is already an established practice aimed at reducing VOC or formulation cost. It is known that this addition can induce a viscosity change in the paint formulation. Experience has shown that it is the low shear viscosity which is more likely to be impacted, sometimes leading to a high in-can viscosity. The change in viscosity can occur at the initial stage of the paint preparation, after one to two days equilibration, or after longer term ageing. Specific additives are available on the market to facilitate the inclusion of water and improve the stability of the resulting heterogeneous, non-miscible mixture. These are marketed as surfactants, wetting agents, coupling agents, etc. Because OPSB is supplied in water, additives can also be used to optimise the rheology behaviour in the reformulated alkyd-based paints. In order to achieve better control of the low shear viscosity, it is advisable to start the reformulation by removing any thixotropic resin or thickening agents from the original formulation. These can be re-introduced at a later stage when fine-tuning the rheological profile.

VOC levels are significantly reduced

Figure 4: OPSB voids well distributed in an alkyd paint film

Equilibrated and aged viscosity remain within control "Fillers for paints" Detlef Gysau www.europeancoatings.com/books

32

The other aspect to consider in order to control viscosity is the stage at which the opaque polymer is added. This can affect both the equilibrated and aged viscosity. Experience has demonstrated that its addition toward the end of the formulation preparation, rather than just after the pigment and extender dispersion, is preferable. The choice of addition stage will, however, depend on manufacturing capabilities. The protocol thus described

European Coatings J OURNAL

ECJ_2010_09_Hb_Garzon.indd 32

09 l 2010

The initial viscosity at low shear can be controlled by maintaining the solvent to alkyd resin ratio of the original reference formulation. Table 2 shows examples of the reformulation with OPSB at different solvent to alkyd ratios, where the thixotropic resin and thickening agent have been removed. Too great a reduction in the solvent to resin ratio can lead to a high initial viscosity (reformulation 1). If the initial ratio is maintained, on the other hand, the viscosity is readily matched (reformulation 2). As far as the level of Volatile Organic Compounds (VOCs) is concerned, Table 2 shows that although reformulation 2 has the same solvent to resin ratio as the reference paint, its VOC is lower. This demonstrates that the incorporation of OP can contribute to an attractive reduction in the emission of solvent. (It is true that a simple water addition also contributes to VOC reduction but this can be at the expense of hiding performance.)

www.european-coatings.com

25.08.2010 14:20:00

10-01-0

Technical Paper Functional fillers Table 2: Viscosity of a reformulated paint can be readily controlled by careful reformulation (column 3) Raw materials

Reference paint Weight %

Reformulation 1 – low solvent/resin ratio

PVC %

31.2

31.2

Thickeners

2.2

0

0

PVC %

TiO2

32.7

22.0

28.7

18.2

28.7

18.2

Extenders

22.5

22.0

15.5

14.4

15.5

14.4

14.8

11.7

14.8

OPSB

0

11.7

Solvent

11.9

8.3

11.9

VOC g/l

320

255

285

Solvent/resin ratio

37 %

26 %

37 %

Initial viscosity (Krebs units)

75

95

74

Brookfield 6 rpm (mPa.s)

1500

4200

1400

Brookfield 60 rpm (mPa.s)

950

2000

880

Reference paint

Reformulation PVC %

Weight %

PVC %

Alkyd resin

30.2

Thickeners

2.2

TiO2

32.7

22.0

28.7

18.2

Extenders

22.5

22.0

15.5

14.4

OPSB

0

11.7

14.8

Solvent

31.2

11.9

11.9 44.0

47.4

Density, g/cm3

1.501

1.354

TiO2 per litre, g

488

388

Scattering

5.2

5.6

Contrast ratio

96.3

96.6

VOC g/l

320

285

Viscosity values

Initial

Equilibrated

Aged

Initial

Equilibrated

Aged

Krebs units

75

88

93

83

94

100

Brookfield 6 rpm (mPa.s)

1500

4000

7200

3500

3600

3900

Brookfield 60 rpm (mPa.s)

950

2300

2930

1540

1970

2580

can itself be sufficient to control viscosity adequately. In cases where additional control of viscosity is needed, the use of additives can help. The typical use level for these additives is 1 % of the total formulation, representing 10 % of the amount of opaque polymer used for the reformulation. Figure 5 compares the equilibrated and aged Brookfield viscosities of a reference paint with a reformulated one where OPSB had been added at two different stages in

European Coatings J OURNAL

09 l 2010

the presence of an additive. The reference paint contained a thixotropic resin and thickening agent. The reformulated ones did not. This shows that in both examples of reformulation the viscosity achieved is below that of the reference paint, and that there is still room for final adjustment with thixotropic resin and thickening agent.

LoVOCo

Tuning the final formulation

0.5

Total PVC %

ECJ_2010_09_Hb_Garzon.indd 34

Weight %

30.2

Weight %

34

PVC %

Alkyd resin

Table 3: Comparison of the original paint and the optimised reformulation with opaque polymer and reduced thickener level Raw materials

Weight %

Reformulation 2 – same solvent/resin ratio

Once the opacity performance and viscosity control steps have been completed, the thixotropic resin and the thickening agent can be re-introduced into the formulation. It is advisable to work with incremental levels of each ingredient. Based on experience, the “demand” for each of them may be lower than in the reference paint. Table 3 shows the final optimised formulation with OPSB. It can be seen that the viscosity profile could be matched to the reference paint by using a lower amount of rheological ingredients, while still maintaining good ageing stability. The reformulation with opaque polymer made it possible to produce a paint having equal, if not better, opacity performance at a significantly lower TiO2 concentration (by ca 100 g/litre of paint, as shown in Table 3) and lower VOC. Although not considered in this paper, the influence of opaque polymer on properties such as gloss and drying were also studied. The control of gloss was achieved through extenders in a similar manner to using opaque polymer in waterbased systems. As far as drying characteristics are concerned, the use of OPSB appeared to have no or limited effect on either “touch dry” or “through dry” times.

New OP is also a ‘drop-in replacement’ in waterbornes The development of an opaque polymer for solventborne alkyd formulations represents a clear improvement in the technology of hollow sphere polymers. Naturally the new polymer has been engineered to the same exacting standards as the best-performing opaque polymer for waterbased paints. This means both particle size and inner void fraction are optimised

www.european-coatings.com

25.08.2010 14:20:00

Technical Paper Functional fillers and combined with uniform particle size distribution. The combination of these parameters leads to optimal hiding performance for enhanced paint film properties. In addition to the compatibility with solventborne alkyds and potential for VOC reduction, the use of this product can be extended into waterborne systems, and it is in fact designed to be interchangeable with existing premium quality opaque polymers that are limited to waterborne paints. This is still possible as OPSB is still supplied as an aqueous dispersion. When tested as a one-to-one replacement in waterborne paints, the product demonstrated similar performance in all types of formulation, from below to above critical PVC, and with binder technologies covering pure acrylic, styreneacrylic, VaVeoVa (ie, poly(polyvinyl acetate-vinyl versatate)) and vinyl copolymers. The possibility of using a single opaque polymer for both water- and solventborne systems offers the advantage of reduced raw material management complexity (single purchasing, reduced number of storage tanks, etc).

Figure 5: Reformulation of alkyd paint with OPSB produces lower viscosities than the original, if the thickening materials are omitted (BKF = Brookfield viscometer)

ACKNOWLEDGEMENTS The author wishes to acknowledge the support of the following: D. Fasano and J. Bardman, Dow Coating Materials, Springhouse, USA, for their support in development of the product and synthesis; G. Lejeune, Dow Coating Materials, Valbonne, France, for her help in the testing and development of formulation techniques. LoVOCoat ad English 06-10 (half page):Layout 1

LoVOCoat polymeric surfactants for high performance, low VOC coatings

28/6/10

14:54

Page 1

Formulating cost effective, low VOC alkyd based coatings with minimum effort LoVOCoatTM Form 100 and LoVOCoatTM Stable 100 polymeric surfactant technology offers the ability to formulate solvent borne alkyd resins into high quality, low VOC trim paints, varnishes and stains. Recommended surfactants allow the incorporation of up to 30% water as a partial hydrocarbon replacement. Performance benefits � easy formulation of low VOC coatings � no compromise on performance versus conventional alkyd coatings � easy to handle & apply - minimal effect on rheology and flow characteristics � cost efficient VOC compliance For more information please visit: www.crodacoatingsandpolymers.com or email: [email protected]

www.european-coatings.com

ECJ_2010_09_Hb_Garzon.indd 35

_ Europeannatural Croda Coatings & Polymers choice 35 09 l 2010 your Coatings J OURNAL

25.08.2010 14:20:01

Technical Paper Waterborne polyurethanes

Cleaner by design Low VOC waterborne PU coatings are hard-wearing and graffiti-resistant Thomas Stingl Peter Schmitt Jeanette Eastman

Coatings must meet several emission requirements

Martin Melchiors Kathy Allen Steven Reinstadtler

Two-pack polyurethanes are well established as high-performance coatings, but stricter regulations on emissions of VOCs both during and after application make it desirable to move to waterborne types. The latest waterborne formulations can now provide surfaces with outstanding cleanability, even with matt finishes. Floor sealing systems which resist tyre marking and spillages can also be formulated.

T

wo-component polyurethane coatings [1] are well established in the construction industry. They are frequently used as floor and wall coatings as they offer high scratch and abrasion resistance, are resistant to chemicals and also have good colour and UV stability. In addition to the requirements of high quality and economic efficiency, the coatings market is also driven by the call for systems that release a minimum of volatile organic compounds (VOCs). Just like other coating systems, polyurethane coatings are under pressure from various regulations. Recent studies show that waterborne two-component polyurethane systems that are virtually free of VOCs can be used to produce wall coatings with outstanding cleanability. They can also produce excellent results in floor sealing systems, protecting the floors of production halls from mechanical loads and indoor parking areas from tyre marks. They are also resistant to the effects of water and chemicals.

For use on building sites, the most important regulation is the Decopaint Directive (2004/42/EU), which limits the total content of VOCs in certain paints and varnishes for painters and decorators. In addition, the REACH regulation, (EC) no. 1907/2006, has to be considered. When this regulation came into force, it triggered a new era for producers of chemicals and products containing them because it meant they must now evaluate their products comprehensively. If a substance is produced or imported in quantities of more than 10 metric tons per year, it is necessary, in order to appraise any potential harmful effect on human health, to define a "limit value" for this effect (the Derived No Effect Level or DNEL). This DNEL is to be compared with the level of human exposure to the substance. If the exposure is lower than the DNEL, the risk is considered to be adequately controlled. What has to be taken into account is not only the shortterm exposure of the painters who handle the paints on the building sites, but also that of the people who later live in the buildings and painters and decorators who work with the paints for long periods. National regulations also exist. In Germany, for example, the "Committee for the health-related evaluation of building products” (AgBB) has drawn up test criteria and developed an evaluation program for VOC emissions from building products that are intended for indoor use. Based on the AgBB evaluation program, the “Deutsches Institut für Bautechnik” (DIBt), which is responsible for the certification of building products, published in August 2004 its "Principles for health assessment of construction products used in interiors". Summarising, this means that organic compounds that escape from the polymer matrix must be assessed by

Table 1: Coating formulations used in the cleanability tests Formulation

Resin Isocyanate Viscosity (cPs) % solids content by volume Corresponding author: Frank Rothbarth Bayer MaterialScience AG T +49 214 30 25363 [email protected]

36

Theoretical VOC [g/l] Finish

2

3

4

5

PES A

PAC Disp. B

PAC Disp. B

PAC Disp. C

PAC Disp.C + PAC Disp. D

HDI biuret N HDI trimer 1

HDI trimer 2 HDI trimer 1

HDI trimer 1

110

1280

3180

1250

640

47.49

55.28

57.95

61.55

55.31

476

97

91

8.3

3.5

glossy

matt

matt

glossy

matt

PES = polyester, PAC = polyacrylate

European Coatings J OURNAL

ECJ_2010_09_Hc_Stingl.indd 36

1 (solventborne)

09 l 2010

www.european-coatings.com

25.08.2010 14:23:16

Technical Paper Waterborne polyurethanes

Figure 1 – Gloss as a function of the blend ratio of two hydroxy-functional resins measuring their concentration under realistic conditions and comparing this with limit values. It is therefore advisable to avoid any significant emissions of such organic compounds in the first place. This can be done with waterborne two-component polyurethane systems. Tests presented here show that, with virtually VOC-free formulations, coatings for the construction industry can nowadays be produced to match the quality level of corresponding solventborne systems. The development of easy-to-clean waterborne wall coatings is discussed below. Possible applications as floor coatings, which require above-average mechanical and chemical resistance, are also considered.

Five formulations compared for graffiti resistance A study was carried out to test five polyurethane topcoat formulations to see how easily the substances used to create graffiti could be removed from them. The formulations were first applied to a test area by roller to a dry film thickness of 75 micrometres. The coatings were then cured for seven days before the graffiti were applied. The cleanability tests were performed in accordance with ASTM D 6578. This considers how defined graffiti can be removed by a defined series of cleaning processes, ranging from repeated wiping with a dry cloth and careful cleaning with mild reagents to the defined use of aggressive detergents. The solventborne Formulation 1, polyester A/HDI-biuret, (Table 1) serves as the basis for comparison and, like all the other formulations, contains normal additives. Binders and hardeners that have proved themselves, among other applications, in anti-graffiti coatings for railway stock and other large vehicles, were then used in waterborne formulations. Formulations 2 and 3 are each based on the same polyacrylate dispersion B, but differ in the polyisocyanate hardener used.

38

European Coatings J OURNAL

ECJ_2010_09_Hc_Stingl.indd 38

09 l 2010

Formulations 4 and 5 each contain the polyacrylate dispersion C. Both of these are “secondary dispersions” in which the polymer was initially formed in a homogeneous organic phase. The resin has a molecular weight approaching that of conventional solvent-borne acrylic resins. In a second step, the resin is then dispersed in water. With Formulation 5, the proportion of secondary dispersion C was reduced compared with Formulation 4, in favour of dispersion D, which is produced directly in the aqueous phase by emulsion polymerisation. Through careful selection of the ratio of dispersion C to dispersion D, both the drying rate and also the appearance of the final coating can be controlled, as shown in Figure 1. The high values for gloss on the left in the graph are those of Formulation 4, while the values for the 60 ° gloss angle

Pre-

Results at a glance Two-pack polyurethanes are well established as high-performance coatings, but stricter regulations on emissions of VOCs both during and after application make it desirable to move to waterborne types. Waterborne PUs that are almost VOC-free can now create wall coatings with outstanding cleanability. It is even possible to produce matt coatings of this type that are cleaned from graffiti. It is also possible to formulate these coatings to cure under adverse conditions and provide excellent results. These coatings are resistant to the effects of water and chemicals and robust enough to protect not only walls but also the floors of production halls from mechanical loads and parking areas from tyre damage.

www.european-coatings.com

25.08.2010 14:23:25

F w p

P

 

Technical Paper Waterborne polyurethanes below 10 (on the right of the graph) correspond to those of Formulation 5. Formulation 4 thus produces a glossy coating and Formulation 5 a matt coating.

Even matt waterborne finishes can be easy to clean As expected, solventborne polyurethane Formulation 1 forms a glossy finish that is easy to clean. The situation is different with the matt coatings produced from the waterborne formulations 2 and 3. Figure 2a shows a good example: The epoxy graffiti paint cannot be removed from the substrate (Formulation 3) even with the strongest cleaning agent in the test, butane-2-one (methyl ethyl ketone, MEK). Waterborne coatings 4 and 5, however, are relatively easy to clean. Figure 2b shows the result for Formulation 5. The epoxy graffiti paint can be removed with an aqueous citrus cleaning agent so that no aggressive detergents are needed. Because Formulation 5 forms a matt film, it is of particular interest for many building applications. It can, for example, be used to protect certain areas of walls that are particularly prone to soiling without their appearance being impaired in any way. For use on exterior walls, it should nevertheless be borne in mind that, especially at low exterior temperatures, the coatings take several weeks to cure thoroughly and assume their final properties. Should graffiti be sprayed on during this period, or if the walls should become soiled, the protective effect of the coatings is limited.

Figure 2: Cleanability of Formulation 2 (figures 2a) versus Formulation 5 (figure 2b)

European Coatings Conferences Berlin/Germany

Pictures: Dmitry Koksharov - Fotolia.com, © Renate Tröe/Pixelio.com Daniel Saint horant - Fotolia.com

Extra

ce tutorials Pre-conferen

Focusing on current developments in raw materials as well as mechanisms and standards the European Coatings Conferences will provide you with ideal networking opportunities and up-to-date information, presenting a suite of high-level technical papers, given by invited international experts. Coming up next!

Packaging coatings

12 – 13 October 2010

Smart coatings

 Sustainable packaging coatings  Printable coatings

 Heat seal lacquers  Hybrid barrier films

 Stimuli responsive polymeric coatings  Anti-icing coatings

9 – 10 November 2010

sponsored by

www.european-coatings.com

ECJ_2010_09_Hc_Stingl.indd 39

Detailed programmes, abstracts and online registration at www.european-coatings.com

Matthias Janz · Project Manager Events Tel. +49 511 9910-273 09 l 2010 [email protected]

 Sensing properties of carbon nanotube composites  Electrically heatable hightech coatings

European Coatings J OURNAL

39

25.08.2010 14:23:26

Technical Paper Waterborne polyurethanes Table 2: Surface energies of three formulations producing matt topcoats Surface energies [ J/m²] Total γs

Water

MI *

Water Receding

γsp (polar cpt)

γsd (dispersive cpt)

Advancing

Advancing

Formulation 2

1.5

29

30.5

93.8 (1.3)

56.8 (0.6)

43

Formulation 3

2.0

21.8

23.8

97.3 (0.8)

69.1 (1.7)

47

Formulation 5

11.0

20.1

31.1

77.0 (1.4)

67.0 (1.8)

42

* MI = methylene iodide (used as the non-polar liquid)

To find out why the matt coatings from Formulations 2, 3 and 5 behaved so differently when it came to cleaning, their surface energy was measured (Table 2). The surprising result was that the surface energy of the three coatings is fairly similar. This contradicts the general view that a good cleaning effect can be achieved by making the surface energy of the coating lower than the surface adhesion of the dirt, which in this case is the graffiti paint. In fact, however, the surface energy

of coating 5 is actually the highest of all, despite the fact that this coating is significantly easier to clean than the others. To explain this surprising result, all the paint films were examined under an atomic force microscope. The coatings from Formulations 1 and 4 (Figure 3a) have a smooth finish as would be expected with a glossy paint film. The matt coatings from the other formulations are all significantly rougher, but to a differing extent. Coatings 2 (Figure 3b) and 3 (Figure 3c) show higher surface roughness

a) Formulation 1+4, AFM scan, roughness RMS value 5.0 nm

b) Formulation 2, AFM scan, roughness RMS value 414 nm

c) Formulation 3, AFM scan, roughness RMS value 337 nm

d) Formulation 5, AFM scan, roughness RMS value 229 nm

Figure 3: AFM scans showing the surfaces of Formulations 2, 3, 4 and 5 (note that the horizontal scales are the same, but vertical (Z) scales differ)

40

European Coatings J OURNAL

ECJ_2010_09_Hc_Stingl.indd 40

09 l 2010

www.european-coatings.com

25.08.2010 14:23:39

Technical Paper Waterborne polyurethanes Table 3: Chemical resistance at different curing conditions 8 °C and 40 % rel. air humidity

8 °C and 85 % rel. air humidity

25 °C and 35 % rel. air humidity

30 °C and 90 % rel. air humidity

Ethyl acetate [1 h]

3

3

3

3

Water (demin.) [16 h]

5

5

5

5

Ethanol (48 % in H2O) [1 h]

5

5

5

5

Red wine [5 h]

5

3-4

5

3-4

Mustard [5 h]

3

3

5

4

Shoe polish [5 h]

5

5

4

4-5

“Forsan” wipe-on floor care [16 h]

5

5

5

5

Ammonia (12.5 %) [1 h]

4-5

4-5

4-5

4-5

Acetic acid (20 %) [1 h]

4-5

4-5

4-5

4-5

Mineral oil [16 h]

4-5

4-5

4-5

4-5

5/5

5/5

5/5

5/5

Chemicals

Impact test [height of fall 0.5 m / 1 m] 5 = best result, no changes; 0 = worst result, film destroyed

than Coating 5 (Figure 3d). This is assumed to be the reason for the better cleanability of Coating 5: the more perfect and smoother the surface, the less easy it is for dirt and paint to stick to the finish.

Good properties obtained under all curing conditions Waterborne two-component polyurethane systems are also used to seal floor coatings. In the past, first-generation products still showed weaknesses in their mechanical and chemical resistance. Under unfavourable circumstances, paint films that came into contact with plasticisers, oil or petrol turned brown. In most cases, however, contact with these media made the paint film swell within a few hours, thereby losing their mechanical properties. Nowadays, however, waterborne sealants based on polyacrylate dispersions such as C or D referred to above and the HDI trimer 1 are noted for the fact that not only are the mechanical properties of the coatings retained even after exposure to liquid media, but also that this is largely independent of the application conditions on the building site (as shown by the test results in Table 3, where grade 5 means "no visible change"; while grade 0 means that the test area is greatly changed or destroyed.) It was found that the coatings are in any case highly resistant to water, cleaning agents and ethanol. Of particular significance for applications in underground parking areas and car showrooms is the fact that the new systems also have good resistance to plasticisers, oil and super grade fuel. The weakness of earlier water-borne polyurethane systems is thus a thing of the past, because the recently developed versions based on these new binders have significantly improved properties.

Resistance to tyre contact also requires high Tg An important issue in the application of waterborne two-component polyurethane systems for the sealing of floors that carry motor traffic is their tyre resistance. Special winter tires with their soft rubber compounds can lead to ugly tyre marks.

www.european-coatings.com

ECJ_2010_09_Hc_Stingl.indd 41

In addition, when vehicles park on the sealants, their tires are usually warm; the normal tyre temperatures under such circumstances of 50–60 °C are above the glass transition temperature of many sealing systems. The result is that the tyre and coating fuse. When the vehicle drives off, it destroys the floor sealant. Extensive tests and practical experience from the last few years have shown that these demands can be satisfied with waterborne two-component polyurethane systems. When formulating the system and selecting the raw materials, particular attention has to be paid to obtaining the right glass transition temperature and crosslink density of the coatings. The production of low-VOC sealing systems based, for example, on PAC dispersion C or D and HDI trimer 1 is possible. The mechanical properties such as hardness and extensibility – which are also needed at low temperatures to comply with the crack-bridging requirements – can be specifically adjusted and are above average.

Green PU coatings are easily mixed and applied With the coating systems described here, no special mixing units are required for stirring in the hardener. They can thus be mixed by hand. Productivity can be further increased through the selection of special internally activated binders [2]. They cure particularly quickly without the potlife being shortened. For example, a polyacrylate dispersion has recently been developed that allows similar formulations to cure almost twice as fast as dispersion C, but still retains its other properties. With waterborne "green" two-component polyurethane systems of the present generation, topcoats can be efficiently produced for walls and floors that satisfy even the strictest specific requirements on chemical and mechanical resistance. Using these waterborne formulations is the most promising strategy to comply with all the environmental and health protection regulations that govern building applications.



REFERENCES [1] Meier-Westhues U., Polyurethanes, Vincentz Verlag, 2007.

European Coatings Conference Polyurethanes for high performance coatings VI 7. & 8. December 2010, Berlin www.europeancoatings.com/ events

"Polyurethanes” Ulrich Meier-Westhues www.europeancoatings.com/books

[2] Irle Ch., Speeding up production, Europ. Coat. Jnl., 2008, No 6, pp 44-49.

09 l 2010

European Coatings J OURNAL

41

25.08.2010 14:23:39

Scientific Paper Anticorrosive coatings

Strength in unity PVDC emulsion plus inorganic binder improves saltspray resistance

* Corresponding Author: Do-hyung (Dohn) Lee KCC Central Research Institute T +82 31 288-3146 [email protected]

Do-hyung (Dohn) Lee* Jae-sung Kim Sung-won Cho A waterborne hybrid protective coating system has been developed which provides very high salt spray resistance with very low VOC levels. Careful selection of the binder system was required to maximise performance, also using a zinc-free anticorrosive pigment to avoid heat degradation. Mechanical properties showed a good balance between hardness and flexibility.

R

ecently, concern with environmental preservation has been growing worldwide, and various environmental preservation measures are being researched and proposed. For this reason, the coating industry has also been trying to progressively reduce VOC emissions from coating materials and also to develop more eco-friendly coatings such as high solids, solventfree and waterborne (WB) paints. The technology that will be described here is an organic-inorganic hybrid waterborne anticorrosive coating which has been Coating material

Permeability, mg/cm2 per day

PVDC

0.31

Nitrocellulose

Table 1: Permeability of various coating materials to moisture

4.8

Phenolic resin

1.1

Chlorinated rubber

1.0

Polyester

1.3

Polyurethane

1.4

Monomer

Table 2: Selected monomers and their reactivity with VDC, quoted from [1]

r1

Styrene

0.14

2.00

Vinyl chloride

3.20

0.30

Acrylonitrile

0.37

0.91

Methyl methacrylate

0.24

2.53

Vinyl acetate

6.00

0.10

Parameter

Values

Monomer composition Appearance Density, g/cm

42

Total solids, wt % pH

1.2 ~ 1.5 55 ~ 60 % 1.0 ~ 3.0

MFFT

10 ~ 13 °C

Particle size

< 250 nm

European Coatings J OURNAL

ECJ_2010_09_Hd_Lee.indd 42

VDC/VC/other acrylic monomer Creamy white liquid

3

Table 3: Specifications of the experimental PVDC copolymer emulsions

r2

09 l 2010

improved through innovative design to surpass the performance of conventional waterborne anticorrosive coatings. This has been achieved by combining a poly(vinylidene chloride) (PVDC) copolymer, a binder that has good barrier properties to both oxygen and moisture, with a nano-scale inorganic binder that has strong mechanical properties and outstanding adhesion properties on various metal substrates. This coating material is eco-friendly, and it shows a striking improvement in anticorrosive properties and water resistance. It also has a good durability due to improvements in toughness and scratch resistance.

Basic concepts of the hybrid system The basic theoretical concept of this anticorrosive coating is to combine a flexible organic material that has low oxygen and moisture permeability as a polymer matrix with a nanoscale inorganic binder that is strong and also has very strong adhesion to metal substrates. By combining this hybrid binder system with an electrochemical anticorrosion mechanism, better anticorrosive performance can be achieved. Over the past few decades, a considerable number of studies on blends or hybrids of organic materials based on synthetic polymers with inorganic materials based on nanoparticles of metal oxide have been actively conducted. As regards the organic materials, poly(vinyl acetate), poly(methyl methacrylate), epoxy, and various other materials have been successfully incorporated into an inorganic matrix. In this study, the hybrid of two materials, a PVDC copolymer organic emulsion binder having excellent barrier properties (see Table 1) and a nano-scale silica based inorganic binder having strong mechanical properties, was created.

Why a poly(vinylidene chloride) copolymer was chosen A binder with vinylidene chloride (VDC) as the main monomer has good impermeability to oxygen and humidity because of its high crystallisation rate and density. Because of these characteristics, PVDC has been used as a barrier resin in solventborne form. The organic binder matrix that will be discussed in this paper does not differ greatly from this, and it inherits these traditional characteristics. However, polymers that use VDC as the main monomer and that have been copolymerised with other vinyl types of monomers are more widely used for coating. A VDC homopolymer emulsion provides a barrier effect, but is not stable. Due to its unusually rapid crystallisation under ambient conditions, it is very difficult to obtain a continuous coating film on the substrate. Therefore, pure PVDC emulsions have hardly ever been used as a coating material. In order to apply PVDC in coatings, it has been necessary to prevent crystallisation in the emulsion during storage, and induce controlled crystallisa-

www.european-coatings.com

25.08.2010 14:28:21

Table 4: Properties of the nano-scale silica binder used Parameter Stabilising counter-ion

Values Sodium/ammonium/chloride

Average particle size

10 ~ 50 nm

Specific surface area

130 ~ 350 m2/g

SiO2 content

25 ~ 50 wt %

pH (25 °C)

4.0 ~ 11.0

Specific gravity

1.18 ~ 1.40

Viscosity (25 °C)

4 ~ 40 cP

Particle charge

negative/positive

tion of the polymer after coating. This can be accomplished by a proper combination of co-monomers with VDC. In order to obtain a satisfactory level of film-forming ability, several co-monomers, such as vinyl chloride and acrylic types (see Table 2), have been used. Sometimes, a small amount of vinyl carboxylic acid or sulfonate monomer is also used to improve the adhesion and storage stability. By means of experiments on the stability of film formation by polymerisation of suitable co-monomers, a more stable organic binder that has an optimum MFFT (Minimum Film Forming Temperature) and can be used under ambient drying conditions could be obtained. The general properties of the experimental PVDC copolymer emulsions which were evaluated in this research are shown in Table 3 and an FT-IR analysis is presented in Figure 1.

Criteria for selecting a nano-scale silica binder The inorganic binder in hybrid coatings is an important material that reinforces the mechanical performance of the final

Results at a glance A waterborne hybrid protective coating has been developed which provides a high level of salt spray resistance with very low VOC levels. The basic concept employs an organic binder with low permeability (a PVDC copolymer) combined with a non-scale silica based inorganic binder that enhances substrate adhesion as well as improving the barrier properties. Since anticorrosive pigments containing zinc can cause degradation of the PVDC at elevated temperatures, a zinc-free active anticorrosive pigment was chosen. The final system shows good anticorrosive performance, low VOC content, a good balance of hardness and flexibility and strong mechanical properties. Research is continuing on improving the weathering resistance of this system, by modifying the organic polymer and/or developing a suitable topcoat.

www.european-coatings.com

ECJ_2010_09_Hd_Lee.indd 43

coating. It is spread uniformly within the organic polymer matrix, and then forms strong bonds between inorganic and organic groups. This coating material can enhance long-term durability under severe environmental conditions, providing heat resistance, non-flammability, good hardness, scratch resistance and water/ seawater resistance. Over the past few decades, various metal oxide based composites have been researched as coating materials. In particular, in this research, the most economical nano-scale silica based inorganic binder was selected. However, traditional alkali silicate inorganic binders were excluded. They were considered unsuitable for the experimental coating due to their content of highly water soluble salts, which causes osmotic film degradation. Thus, the chosen nano-scale silica binder has a relatively low water soluble salt content, instead of being based on alkali silicates. The nano-scale silica binder is a stable inorganic binder which is stabilised by an electrostatic repulsion balance due to an electric double layer in water. When the balance collapses, the particles begin to agglomerate with each other or change into gel or condense. Because the film-forming ability of the nano-scale silica binder itself as a main binder was poor in the experimental coating, it was used as a subsidiary binder to reinforce the organic polymer matrix. The general properties of the nano-scale silica binder used in these experiments are shown in Table 4.

Achieving a stable binder mixture is not simple According to reference [2], when a film is formed by a solventborne PVDC matrix including well dispersed nano-scale silica particles, its surface structure is formed in the manner shown in Figure 2(b). When the content of nano-scale silica particles is at an optimum level, the water vapour permeability is dramatically reduced and reaches its minimum point. If it exceeds a certain critical point, however, the coating becomes more porous and water vapour permeability increases, as shown in Figure 3. Based on this principle, the organic and inorganic binders discussed in the previous sections were combined for this experiment. However, this hybridising work was not simple as it involved combining two materials that are unstable for several distinct reasons. A low pH and the existence of chloride ion in the organic binder had a serious effect on the stability of the inorganic binder when the two were mixed.

09 l 2010

European Coatings J OURNAL

43

25.08.2010 14:28:22

Scientific Paper Anticorrosive coatings

P(VDC-co-AN) film

P(VDC-co-AN)/SiO2 hybrid film

Figure 2: Topographic views of organic-inorganic hybrid films [2] Figure 1: FT-IR analysis of an experimental PVDC copolymer In practice, some of the experimental hybrid compounds immediately changed into a gel when they were mixed. Table 5 shows the results of the stability tests of the nano-scale silica binders in relation to the stabilising mechanism, with the same organic polymer. As can be seen in Table 5, the mixture of PVDC copolymer emulsion and nano-scale silica binder has better stability when the silica surface has a more negative charge, a larger particle size, and a lower pH. In particular, the nano-scale silica binder with most of the alkali ion removed showed the most stable tolerance to low pH and various ionic substances of the PVDC emulsion. In this study, organosilane was also introduced in order to increase cohesion and particle stability at the interface of the organic emulsion and nano-scale silica particles. Organosilane was adopted without regard to its specific type, but the one which was the most stable in the pres-

Figure 3: H2O permeability of organic-inorganic hybrid films [2]

European Coatings J OURNAL

ECJ_2010_09_Hd_Lee.indd 44

Zinc-based pigments promote heat degradation A PVDC coating film containing zinc compounds showed excellent corrosion resistance in practice, but it also showed an irreversible breakdown at high temperatures of over 90 °C. This therefore means that the use of anticorrosive pigments such as zinc phosphate and zinc dust, which impart a cathodic passivation effect or cathodic protection effect, is limited and they should be carefully selected. Zinc compounds accelerate the degradation of the coating film caused by the dehydrochlorination phenomenon of PVDC copolymers at high temperatures. Heat stability can be enhanced by using corrosion inhibiting materials that do not contain zinc compounds. However, the anticorrosive performance then normally drops significantly. Organic-inorganic hybrid technology offers a possible solution to this problem. In the test results, the experimental hybrid coating film containing a corrosion inhibiting material such as calcium ion exchanged silica rather than zinc compounds showed good heat stability with synergistic effects on the anticorrosive properties.

Good corrosion resistance and physical properties

Figure 4: 1000 x magnification of coating films: (a) organic-inorganic hybrid surface without organosilane; (b) with organosilane

44

ence of the aqueous solution or the aqueous dispersion after hydrolysis was selected. When this was added to the experimental WB protective coatings, several further advantages, such as better adhesion to metal substrates, film density and smoothness of the coating film surface, could also be obtained (see Figure 4). The results of this study on organic-inorganic hybrid WB anticorrosive coating showed significantly upgraded coating film properties compared to the corresponding conventional WB organic coating.

These experimental results led to the conclusion that, compared to conventional WB protective coatings, improved film performance could be obtained from this WB PVDC/nano-silica hybrid protective coating. Figure 5 reveals the results of a 1000 hours salt spray test (to ASTM B117). These results showed that the new ex-

09 l 2010

www.european-coatings.com

25.08.2010 14:28:23

Scientific Paper Anticorrosive coatings

Test/panel ref.

Scribed area

A: WB organicB: Conventional inorganic hybrid WB acrylic protective coating (100 µm thick) (100 µm thick)

C: 2K SB epoxy (100 µm thick)

D: 2K SB epoxy (250 µm thick)

E: 1K WB epoxy ester (100 µm thick)

Rust

9

5

1

4

1

Blister

10

4M

2F

4F

2MD 1 mm

Creep

0.3 mm

1 mm

3 mm

1 mm

Unscribed area

Rust

10

5

5

10

9

Blister

10

4D

2MD

10

2M

A

B

C

D

E

Figure 5: 1000 hours salt spray test results of protective coatings on steel substrates according to the panels.

perimental WB anticorrosive coating outperformed even anticorrosive systems based on 2K solventborne epoxy coating, a conventional 1K waterborne epoxy ester and waterborne acrylic emulsion paint. In particular, the corrosion-inhibiting performance in the scribed area of the test panels was significantly different from the condition of the control samples. Furthermore, premature coating film failure, such as heat induced blistering and peel-off phenomena, which were noted at high temperatures above 90 °C, was improved without any reduction of the anticorrosive properties. This means it can be concluded that one of the major obstacles to expanding the use of WB PVDC protective coating in the industrial field has been resolved. In addition to the performance described above, the new protective coating also has good mechanical performance. In conventional general protective coatings, a barrier effect can be achieved by making the coating film thick, but sometimes this also makes the coating film very brittle. However, by the complementary combination of the flexible characteristics of an organic emulsion binder and the reinforcing effect of an inorganic binder, this WB coating is not only tough but also flexible. And it also showed barrier properties even at low film thickness. This can be demonstrated through the bending test and impact resistance test results (see Figure 6).

Research continues on improving weathering resistance By performing a series of general property evaluations on this new waterborne protective coating, it has been demonstrated that some technological improvements have been achieved. In this study, an advanced WB protective coating technology with a good anticorrosive performance was successfully obtained by use of the ideal combination of a PVDC copolymer and a nanoscale silica binder. The heat degradation of the coating film was also minimised without any loss of anticorrosive properties, and the mechanical properties of the WB anticorrosive coating were enhanced.

www.european-coatings.com

ECJ_2010_09_Hd_Lee.indd 45

However, the weatherability of PVDC itself still seems to be limited. Improvements to the weatherability of PVDC based WB coatings have been investigated by introducing pure acrylic monomers or by blending it with other highly weatherable polymers. Additionally, to overcome this weak point, further research on a new waterborne topcoat based on highly weatherable binders including silicone-acrylic emulsion is currently in progress. This technology would provide a complete durable waterborne protective coating system.

í

A

Figure 6: Mechanical properties of WB PVDC/nano-scale silica binder coating: (A) bending test, 2 mm mandrel pass; (B) impact resistance test, 120 lb-in pass

B

Table 5: Stability tests on organic-inorganic hybrids Variables Stabilising ion Type of inorganic binder

Particle size (nm) Particle charge pH (25 °C)

Stability

Seeding Thickening % **

1*

2

3

4

5

Na+

Na+

Na+

NR4+

Cl-

20

10

20

20

20

-

-

-

-

+

5

10

9

9

4

none

few

none

few

severe

20

100

50

gel

gel

* Deionised nano-scale silica binder ** Comparing final and initial viscosity in Krebs units

REFERENCES [1] Wessing R. A. et al., Vinylidene chloride monomer and polymers, 1997, Vol. 24, John Wiley & Sons, pp 882-923 [2] Hwang T. et al, Synthesis and barrier properties of poly(vinylidene chloride-co-acrylonitrile)/SiO2 hybrid composites by sol-gel process, Jnl. of membrane science, 2009, Vol. 345, pp 90-96.

09 l 2010

European Coatings J OURNAL

45

25.08.2010 14:28:24

Events CoSi

Source: Gerard Scholten

Attendees of the CoSi conference 2010 took the opportunity to engage in lively discussions

Scientific backgrounds Coatings Science International Conference presents latest coating developments

Kirsten Wrede In the beautiful Dutch seaside village of Noordwijk, the Coatings Science International Conference - in short: CoSi 2010 – took place from 28 June to 2 July, 2010. As in the past years, the conference put a clear focus on the scientific backgrounds of the newest technological developments relevant to coatings.

Video interviews on new developments: www. european-coatings. com/videos/

46

A

gain, the CoSi conference offered a convenient platform for free exchange of scientific knowledge between both academic and industrial scientists from all over the world. As chairman Prof. Rolf van Benthem, Eindhoven University of Technology, put it, 2010 was a special year for the conference. For the first time, more than 160 abstracts had been submitted for the conference program. 32 of them were finally selected for presentation, with 20 talks given by university speakers

European Coatings J OURNAL

ECJ_2010_09_I_Events_Cosi.indd 46

09 l 2010

and 12 lectures coming from industrial institutions. With 140 attendees – 85 from academia and 55 from the industry – also the number of participants was higher than ever before. While the majority of the attendees from 27 different countries came from Europe, van Benthem emphasised that also Asia was well represented. The conference was divided into ten sessions, covering weathering and degradation, hybrid materials and nanocomposites, material characterisation and modeling, pigments and colorants, corrosion protection, functional coatings, waterborne systems, textured coatings, and applied coatings.

Subjects of the conference Due to different expectations and backgrounds of the attendees, it is hardly possible to pick out “the” highlights of the conference. Nevertheless, several interesting talks will be summarised in the following.

www.european-coatings.com

25.08.2010 14:31:00

Events CoSi The very first presentation kicked off the session on weathering and degradation. Dr. Tinh Nguyen, National Institute of Standards and Technology, USA, investigated the degradation and nanoparticle release of an amine-cured epoxy coating containing multiwalled carbon nanotubes and silica nanoparticles exposed to UV radiation. Based on experimental results, one of his conclusions was that polymer chains in amine-cured epoxy nanocomposite coatings undergo photodegradation under UV radiation, resulting in a substantial mass loss and a marked increase of nanoparticle concentration on the coating surface. According to Nguyen, the results of his study provide valuable information to assess the potential risk of nanoparticle release from expoxy coatings during service.

Biobased approach A lot of attention was paid to a biobased approach: Dr. Funda Tihminlioglu, Izmir Institute of Technology, Turkey, presented a study that investigated the feasibility of prepared novel corn-zein nanocomposite (CZNC) coated polypropylene film (CZNC-PP) structures for food packaging applications. The good oxygen barrier of corn zein was successfully combined with mechanically strong PP for food packaging. The incorporation of organomodified montmorillonite layered silicate into the corn-zein matrix improved the oxygen barrier and the mechanical properties of the corn-zein coated bilayer PP film. The results of the study showed that corn-zein nanocomposite coatings could be used as a barrier layer in food packaging applications.

Source: Gerard Scholten

Dr. Volkmar Stenzel (left) received the Innovation award from Prof. Bert de With

Sonochemical coating Two sessions were dedicated to functional coatings, reflecting the high interest in this exciting field of technology. Prof. Aharon Gedanken, Bar-Ilan University, Israel, talked about the coating of surfaces by sonochemical methods. When ultrasonic waves collapse near a solid surface microjets are being formed directed towards the solid surface. These microjets are moving at very high speeds >200 m/sec. This phenomenon can be used for coating nanoparticles on metals, polymers, glasses, ceramics, textiles, and paper. In his presentation Gedanken explained a few applications of this method, one of which is the coating of antibacterial nanoparticles on textiles and glass.

Spectrally selective coatings Polymer-based pigment coatings on flexible substrates with spectrally selective characteristics to improve the thermal properties were the topic of Dr. Jochen Manara, Bavarian Center for Applied Energy Research, Germany. Spectrally selective coatings on flexible substrates considered in his work combine a customised colour (or visual appearance) with a low emittance in the infrared spectral range. In order to realise the desired properties, polymer-based pigment coatings were developed, optimised and characterised.

www.european-coatings.com

ECJ_2010_09_I_Events_Cosi.indd 47

Networking and award winners The local organisation of the conference was handled by van Benthem and Prof. Bert de With, along with their team of Eindhoven University of Technology. In addition to the technical presentations, the conference was complemented by various networking opportunities. At the end of the conference the CoSi awards for Science, Innovation and Creativity were given to this year’s winners. Prof. Christine Jérôme, Center for Education and Research on Macromolecules (CERM), University of Liège, Belgium, received the Science award for the best scientific paper. She presented her research on biomimetic coatings with robust antibacterial properties. Dr. Volkmar Stenzel, Fraunhofer Institute for Manufacturing Technology and Applied Materials Research (IFAM), Germany, won the Innovation award for the most interesting new development presented at the conference. His presentation focused on drag reducing paints for the reduction of fuel consumption in aviation and shipping. The Creativity award for the best poster went to Dr. Catarina Esteves, Eindhoven University of Technology, The Netherlands, for her presentation on superhydrophobic self-replenishing coatings through the design of surface topology and chemistry. The jury consisted of members of the CoSi organising committee.



09 l 2009

Find more information at www.coatingsscience.com

European Coatings J OURNAL

47

25.08.2010 14:31:05

Market Place Novel products Inline tester for evaluating surfaces With “SurfMax”, Carl Zeiss is offering a configurable inline tester for the surface evaluation of 3D parts. This gives objective and reproducible results which are not subject to the fluctuations caused by the subjective nature of visual inspections. The results are documented automatically, allowing the operator to take decisions to optimise the production process and to present them to customers as logged data. The instrument thus helps increase quality and efficiency in production, and it supports parts of readily manageable size as are common with visual inspections. The technology used and the configuration possibilities allow a wide range of uses for different materials and processing and coating methods. Possible applications include metal, plastic or ceramic surfaces, from matt to glossy. Carl Zeiss OIM GmbH DE-Wangen [email protected] www.zeiss.de/oim

Contact angle measurement in bird’s-eye view

Spray drying for minimal sample sizes

A new measuring technique from Krüss is moving analytical surface science forward. The “Top View Analyzer TVA100” measures the contact angle from above, using the distance between spots of light reflected from the curved drop surface. The system allows measurements on concave surfaces or surfaces in recesses in which it would not be possible to measure the contour with the illumination, sample and optics in a single plane; examples include microtitre plates or mounted PCBs. In addition, viewing from above makes uneven wetting immediately apparent. Thanks to the non-sensitive precision drop deposition, it is possible to determine the surface free energy with a wide range of liquids. The measuring head is available as a module for the existing range of Krüss instruments, or as an independent portal system for contact-free measurement on large samples.

Spray drying on a laboratory scale is becoming a more and more important method: it is universally applicable and easy to perform, and can be scaled to almost any sample size. With the technology and equipment dimensions available previously, it was limited to a particle size range of 1 – 25 μm. Now the “Nano Spray Dryer B-90” is opening up new possibilities: the piezoelectric spray head has a very thin vibrating membrane which, using spray drying, can generate particles even in the range from 300 nm to 5 μm without difficulty. The membrane has an array of micron-sized holes and vibrates at ultrasonic frequency. Millions of precise droplets with a narrow size distribution are produced every second by the spray head. Three different membranes are available, with hole diameters of 4.0, 5.5 and 7.0 μm respectively, giving droplet sizes of 8 – 21 μm. The dried particles are collected in an electrostatic particle separator which can attain yields of 90 %.

Krüss GmbH DE-Hamburg [email protected] www.kruss.de

Büchi Labortechnik GmbH DE-Essen [email protected] www.buechigmbh.de

48

European Coatings J OURNAL

ECJ_2010_09_J_Market Place.indd 48

09 l 2010

Waterborne epoxy dispersion offered for protective coatings Cytec Industries announced the launch of “Beckopox EP 2384w/57WA” – a new solvent-free waterborne epoxy dispersion. This product is designed for high performance waterborne ambient cure twocomponent epoxy monocoats and primers for metallic substrates. When used with “Beckopox VEH 2188w/80WA” waterborne amine hardener, it enables customers to formulate below 50 g/l VOC, while exceeding 1000 hours salt-fog without the need for anti-corrosion pigments. Furthermore, coatings are fast drying and hard. These additional benefits provide early handling, fast top coating and early water resistance. According to the manufacturer, the new dispersion outperforms other waterborne epoxy dispersions, while maintaining very low VOC, especially in corrosion and water resistance. The product is suited for factory applied coatings as well as field applied protective coatings. Cytec Industries Inc. USA-Woodland Park [email protected] www.cytec.com

Determine the charge of aqueous solutions with precision Charge conditions in aqueous solutions often play a critical role, whether the field is the treatment of waste water, surface treatments, or the manufacture of drinks, foodstuffs, ceramic materials, paints, cosmetics or textiles. This broad range of applications is covered by the “Mütek PCD-04 Particle Charge Detector” from BTG, which measures the charge of the colloidal substances in an aqueous sample, giving reliable results even with high conductivity values. The unit comes in two variants: a “travel” version with integrated titrator, and a standard version without. Used in a research and development environment, both can be combined with the “PCD-T3” titrator. This allows both polyelectrolyte titration and acid/base titration in order to determine the pH value at the isoelectric point. Software with a wide range of functionalities makes it possible to handle and document data to GLP standards. BTG Instruments GmbH DE-Herrsching [email protected] www.btg.com

www.european-coatings.com

25.08.2010 15:05:39

Market Place Novel products Additive for spray application of waterborne coatings A new substrate wetting additive from Evonik Tego Chemie GmbH guarantees fine atomisation and defect-free films in spray-applied waterborne coatings systems even at minimal film thickness. This reduces both defect rates and remedial work in the painting process. “Tego Wet 240” provides good substrate wetting, regardless of co-solvent content, even in the newest binder systems. With its good anti-cratering characteristics and problem-free overpainting, this solventfree additive can be widely used and is particularly suitable for spray-applied industrial coatings and coatings for plastics. Evonik Tego Chemie GmbH DE-Essen [email protected] www.tego.de

Automatic film applicator The robustness of many products, including paints, varnishes, inks and adhesives, is directly related to the quality of many of the laboratory tests carried out on material samples. The “Elcometer 4340” is an instrument for preparing various product samples. Adhesives, paints and other products can be applied to a variety of substrates consistently and reproducibly. Unlike film applicators that are operated manually, with this automatic unit there is no variation in pressure or speed, since the human factor is eliminated. The instrument is versatile, rugged and precise, and is designed to allow concurrent applications. Whereas glass is commonly used as the table material, in this applicator the tables are made of precision-engineered aluminium. This gives a high flatness rating of up to +/- 2 µm, making it possible to test both thin and thick substrates to the most demanding requirements. Elcometer Instruments GmbH DE-Aalen [email protected] www.elcometer.de

Self-curing core-shell dispersion Alberdingk Boley has launched a new highperformance dispersion in the form of its new self-curing core-shell product, “Alberdingk AC 2782”. The main application for this acrylic copolymer dispersion is that of industrial furniture coatings. As a result of its good drying properties, formulations based on this binder can be used even in equipment with short production cycles, so coating is cost-efficient. Among the properties of the product is good resistance to hot water. The integrated self-curing system means that the binder also guarantees good chemical resistance, particularly to water and ethanol. Other advantages of the dispersion include good grain enhancement properties, rapid sandability and, uniquely, its good water resistance in heavily matted systems. Alberdingk Boley GmbH DE-Krefeld [email protected] www.alberdingk-boley.de

Dispenser measures out minute quantities The new “ViscoPro-M” dispenser from ViscoTec GmbH allows very small quantities to be applied reliably. This system makes it possible to dispense minute quantities accurately, right down to 0.004 ml. It has been designed for use in industry, and is compatible with any axial or robotic system, but may also be used manually. Based on the principle of the ViscoTec endless piston, the new dispenser has no problems with dripping, stringing or variations in viscosity. Since the system has no valves, it is suitable even for extremely high viscosities and for abrasive materials or those sensitive to shear. The only process parameter is the speed of rotation at which the quantity output is regulated. The result is a vast range of applications, from dot dosing or bead dosing to encapsulation. It is even possible to make dynamic changes in volume while dosing is being performed. ViscoTec Pumpen- u. Dosiertechnik GmbH DE-Töging a. Inn [email protected] www.viscotec.de

50

European Coatings J OURNAL

ECJ_2010_09_J_Market Place.indd 50

09 l 2010

Building blocks are food contact approved Croda Coatings & Polymers launches “Pripol-F”, a new range of biobased building blocks designed for food contact applications. The “Pripol C36” dimer fatty acid product range is based on natural fatty acids, a green and renewable resource. Its branched structure offers flexibility to the resins and the hydrocarbon character imparts water repellency. The new hydrogenated dimer grades can be used in a wide range of materials that are intended to come into contact with food such as food packaging adhesives, coatings on food packaging, coatings for food processing equipment and laminate foils for microwave food packaging. The new product range is food contact approved in Europe (EU directive on food contact plastic materials) and is FDA compliant. Croda Coatings & Polymers NL-Gouda www.crodacoatingsandpolymers.com

Wax emulsion additive can improve scratch resistance Michelman’s “Michem Lube 190” is an anionic polyethylene wax emulsion additive that significantly improves the mar and scratch resistance, and water repellency, of architectural and decorative paints, stains, sealants and numerous other interior and exterior coatings. It is commonly used in exterior wood coatings when abrasion resistance is required along with water beading, and can provide blocking resistance as well. This low-VOC surface modifier is also used in rub resistant high gloss OPVs and topcoats where water sensitivity is important. It produces good results at 5 % in styrenated acrylics from 200 to 500 strokes. Michelman USA-Cincinatti [email protected] www.michelman.com

Looking for more novel products? Browse the EC Market Navigator, your supply network: www.european-coatings.com/ marketnavigator

www.european-coatings.com

25.08.2010 15:05:45

Market Place Novel products Metering pump with controlled solenoid drive

Polyester resin focuses on epoxy-free coatings

Cellulose-based additive for waterborne coatings systems

The “Delta” diaphragm metering pump with solenoid is equipped with the “Opto Drive” controlled drive, which means that the suction and pressure strokes can be fully monitored. The manufacturer reports that this allows optimum adaptation to different metering tasks. The integrated injection control unit “Opto Guard” monitors the hydraulic peripheral devices. The metering pump is suitable for almost any application thanks to numerous drive options and the use of “Profibus” or CANbus to connect to the central control station. Where the “Process Timer” option is fitted, the pump can be used as the control centre in cases where programmable logic controllers would otherwise be required.

DSM Powder Coating Resins expands its portfolio of polyester resins for epoxy-free coatings with a new resin in its “Uralac Veranda” polyester resins range. The range is based on a patented technology and it meets a demand for epoxy-free alternatives to hybrid powder coatings. The new “Uralac Veranda P 542” features good flow in highly filled coatings and improved processing properties. The product, furthermore, is HAA curable and designed for coating systems that can replace epoxy hybrid systems with an equal or better performing system. The products of the polyester resin range provide good chemical and staining resistance, good boiling water resistance, as well as improved outdoor durability with reduced yellowing.

Prominent Dosiertechnik GmbH DE-Heidelberg [email protected] www.prominent.de

DSM Powder Coating Resins NL-Zwolle [email protected] www.dsm.com

Eastman Chemical Company is poised to introduce its newest „Solus” performance additive, “Solus 3050”, which is specifically engineered to help formulators meet VOC, performance and productivity goals in waterborne coatings systems. It is scheduled to launch at the end of 2010. Derived from natural and renewable cellulose material, the additive will be of interest to the automotive, industrial metal, and consumer electronics coatings markets. Its performance benefits include smoother finish, optimal metallic flake control, better redissolve/strike-in resistance, superior flow and leveling, improved atomisation, and greater adhesion to galvanised steel. Additionally, it offers faster dry time and early hardness, application consistency over varying climatic conditions, improved wetting, increased sag resistance, and it enables flexibility in aluminum flake selection. Eastman Chemical Company USA-Kingsport www.eastman.com

Extension to deflected flame spray systems Dissolver with special vacuum system The distinguishing feature of the “Dispermat VE25” vacuum dissolver from VMA Getzmann is the particular design of the vacuum system: the dispersion system comprises a cubic, vacuum-tight base unit with a large hinged door, a floor that can be slid out horizontally to support the containers, and an integrated container clamp system. This allows any vessel with a capacity of between 3 and 25 litres to be clamped inside the vacuum chamber simply and conveniently. The machine’s powerful 4-kW drive gives fast and effective dispersion results. VMA Getzmann GmbH DE-Reichshof [email protected] www.vma-getzmann.de

www.european-coatings.com

ECJ_2010_09_J_Market Place.indd 51

Metallisation has launched a new deflected flame spray extension to fit its “MK73” and “MK61” flame spray systems. The new extension has been developed as a direct result of customer requests for a system that can apply good quality coatings to difficult access areas. The new robust deflected flame spray extension has been designed specifically for onsite use. It comes in three lengths, 150 mm, 300 mm and 450 mm and can be used with either 3.17 mm or 4.76 mm wires. The new extension has been designed to use the same consumable spares as the standard flame spray pistols. The extension unit can spray directly forward or at a deflected angle, which can range from 0º to 90º by varying the deflector air pressure. The deflection nozzle can also be rotated through 180º to allow spraying in a 360º arc around the pistol. Flame spray coatings form a dense, strongly adherent coating suitable for corrosion protection. Metallisation GB-Dudley [email protected] www.metallisation.com

09 l 2010

European Coatings J OURNAL

51

25.08.2010 15:05:45

Calendar of Events 2010

European Coatings Symposium

Conferences 15 – 17 September 2010 CIS Coatings and Raw Materials Market 2010 Alushta, Crimea/Ukraine www.b-forum.ru



Modern coatings for plastics

16 - 17 September 2010 Feica European Adhesives & Sealants Conference 2010 Helsinki/Finland www.feica-conferences.com/ invitation/welcome

29 October 2010 | Düsseldorf/Germany

Plastic coating – Challenges and solutions

22 - 24 September 2010 CEPE Annual Conference & General Assembly Istanbul/Turkey www.cepe.org

They are still notoriously difficult – when it comes to coatings and coating processes, plastic parts, with their low surface energy and their often complicated shape, pose some of the hardest challenges. This symposium provides an overview of the most recent developments in this field, ranging from new coating raw materials, to new coating systems and new surface modifications. The event is especially dedicated to innovative materials and technologies for the coating of plastic substrates - including coatability and pretreatment aspects of the substrate material itself, novel raw materials and formulations for coatings, as well as application aspects. Several presentations will be focused on waterborne technology, as this is one of the most important future technologies for the coating of plastics. Also functional coatings will be addressed as well as UV technology and renewable materials.

Pictures: Doc RaBe - Fotolia.com, Sulabaja - Fotolia.com, Maria Cristina Sterra - Fotolia.com

3 - 4 November 2010 Car Body Painting 2010 Bad Nauheim/Germany www.automotive-circle.com



Exhibitions 23 - 26 September 2010 Paint Istanbul 2010 Istanbul/Turkey www.paintistanbul.com

5 - 6 October 2010 Coatings Trends & Technologies (CTT) Conference Lombard, IL/USA www.coatingsconference.com

27 - 29 September 2010 Chinacoat 2010 Guangzhou/China www.chinacoat.net



An excellent opportunity to get more mission critical information in less time.

13 – 14 October 2010 North African Coatings Congress 2010 Casablanca/Morocco www.coatingsgroup.com

23 - 26 September 2010 Paint Istanbul 2010 Istanbul/Turkey www.paintistanbul.com

11 - 13 October 2010 2010 Tappi Advanced Coating Fundamentals Symposium Munich/Germany www.tappi.org

For the first time this event takes place in Düsseldorf/Germany, contemporaneously with the K 2010, the world’s leading trade fair for the plastics and rubber industry.

12 - 14 October 2010 5th World Congress on Emulsions Lyon/France www.cme-emulsion.com

12 - 13 October 2010 Wood Coatings Congress Amsterdam/The Netherlands www.pra-world.com 12 – 13 October 2010 European Coatings CONFERENCES: Packaging coatings Berlin/Germany www.european-coatings.com/ events/ecc.cfm



More coatings events at www.european-coatings.com events/coatings_calendar

12 - 14 October 2010 COROSAVE Stuttgart/Germany www.corosave.de 9 - 11 November 2010 Eurocoat 2010 Genoa/Italy www.eurocoat-expo.com

New events in our list  

or events with changes.

Would you like to include your company event in our Events section? For more information please contact our advertising sales team: Sabine Wilkens Tel. +49 511 9910-255, [email protected]

All detailed information at Vincentz Network Plathnerstr. 4c 30175 Hannover Germany Contact: Nicole Steinbach · T +49 511 99 10-274 52 [email protected] http://www.european-coatings.com/events/ecc-symposium.cfm

ECJ_2010_09_K_Calendar of Events.indd 52

25.08.2010 14:37:43