Rad-Cure Coatings

If niche coatings are described as products developed for a specific market with somewhat limited application opportunities, how much longer will radiation-cured coatings fall into this category? The marketshare that UV/EB technology holds within some segments, and the coatings industry as a whole, remains small, but interest continues to grow rapidly.

The Freedonia Group, Cleveland, OH, reports that the U.S. rad-cure coatings market will increase at a rate of 10% per year to 102 million pounds in 2003, compared to 63 million pounds in 1998. The number of market segments that use UV/EB coatings also continues to grow, wood, packaging, industrial and automotive coatings are just a few of the end-use markets that have recognized the advantages of the technology's instant cure abilities.

Why is UV/EB, a technology first introduced to the industry more than 30 years ago, now growing at such a fast pace?

"Demand is steadily rising due to environmental factors and the need for increased productivity and lower applied cost," said Ben Curatolo, director of technology, UV Coatings Limited, Berea, OH.

"The benefits of UV/EB systems, no VOC, very fast cure and low energy requirements, make the technology very attractive," said Jim Yosh, business manager, Tego Chemie Service.

Once known as a coatings system offering mainly environmental benefits, rad-cure technology now also boasts improved performance properties that make it a viable alternative to other coatings systems.

"Environmental reasons are still a dominant reason for choosing a UV cured coating, though the productivity benefits of their fast cure time are equally important," said Clai Bachmann, senior vice president, marketing and communications, Dymax Corporation, a manufacturer of conformal coatings for the protection of printed circuit boards. "Even with the higher cost per pound of the UV coatings, all of the savings in time, labor, energy and lower use of plant space often make them the much more economical choice."

"Green technology will always be important, but we are also seeing the UV/EB industry focus on the enabling properties," said Chris Bradford, senior technical service representative, BASF automotive OEM coatings group. "UV/EB enables the end-user to develop balanced properties and processes that no other technology can approach. UV/EB is truly an enabling technology."

Jim Raymont, director instrument markets, EIT, said another factor driving growth of rad-cure coatings is the availability of better finished products that may offer increased durability and higher gloss. "UV products are also allowing end-users to achieve greater productivity," he said.

Ramesh Narayan, commercial development manger, Cognis energy cure chemicals, added, "Product performance, increased productivity and throughput, lower capital (space and equipment) requirements to start new facilities and significantly lower waste disposal costs are also key drivers for growth in this market."

Continued improvements in equipment used with UV/EB coatings have also made the technology more attractive to end-users.

"In the past, the acceptance of UV and EB systems were limited by 'mechanical' constraints," said Mr. Yosh. "The industry grew up around flat stocks where the curing lamps could be aimed directly down on the substrate being coated and cured. As time has passed, coatings and equipment manufacturers have worked together to eliminate many of the shadow cure problems of the past. This opened the industry to applications as numerous as the coatings industry itself."

"Another growth driver has been the development of dispensing and sensing equipment that allows precisely controlled placements of the coatings," said Ms. Bachmann. "In the case of conformal coatings, this means that waste is virtually eliminated. Since the materials do not contain solvents, there is no need for expensive ventilation and reclamation equipment."

A good illustration of the technology's continued growth comes from Star Technology. According to Donn R. Starkey, president of the Waterloo, IN-based coatings manufacturer, in 1990, approximately one out of 20 inquiries were for a UV product. "That has now changed to about one out of two inquiries," he said.

Racing Ahead
As rad-cure coatings manufacturers continued to improve the technology's performance properties and capabilities, it was only a matter of time before the automotive industry jumped on the UV/EB bandwagon.

"Automotive is an emerging market for rad-cure coatings," said Mr. Bradford of BASF. "These systems can offer the economic and environmental savings that are critical to the long-term direction and profitability of the industry."

"Every car has some sort of UV/EB cured product on it," said Gary M. Cohen, executive director, RadTech International, North America. "The potential is really big."

One reason rad-cure technology could become the wave of the future for the automotive industry down the road is the improved performance properties it offers.

"Rad-cure in automotive paint offers large opportunities that have made it a major focus of development work by paint companies and car makers," said Godwin Berner, head business line coatings, coating effects segment, Ciba Specialty Chemicals. "This is driven primarily by features like improved scratch resistance in OEM and increased productivity in refinish paints. Thus, rad-cure is seen as one of the most promising technical options to make automotive topcoats scratch resistant, which is essentially done by an increased crosslinking of the paint surface by a UV flash following conventional curing. The significantly reduced dry time in refinish paint shops will enable the owners to significantly increase productivity of their booths."

Another reason UV/EB coatings systems are becoming more attractive to automakers is the first reason the rest of the industry began to take notice, environmental benefits. "The recent trend in the automotive industry to improve both economic and environmental efficiencies has prompted interest in alternative technologies," said Mr. Bradford. "Rad-cure technology is one of a very few technologies that will allow them to meet these directives. In addition, UV and EB are enabling solutions as the industry looks for innovative ways to accomplish seemingly impossible tasks."

But before rad-cure topcoats become commonplace, the industry is much more likely to see UV/EB coatings for under-hood applications.

"The long-term weatherability of UV-cured coatings for exterior automotive applications needs further improvement before they find wider acceptance," said Mr. Narayan of Cognis.

"Although the automotive market has not seen wide use of UV products in the trim and vehicle finish areas, UV cure technology is widely used in sub-assemblies such as air moving motors, gaskets and sealants in under-hood applications," said Mr. Starkey of Star Technology.

But while performance properties are improved, application uses are expanded and costs come down, rad-cure coatings technology still might find itself at the back of the pack.

"Solventborne coatings have a long history of use in the automotive industry," said Mr. Bradford. "In the past 20 years, waterborne technologies have become a very competitive, viable alternative. Rad-cure coatings do not have this same history in the automotive industry. They have maintained a position of curiosity; being used on trim, under-hood and lighting components. The presumed apprehensions of durability and three-dimensional cure have limited the market entrance. As companies invest more resources and research and development efforts in advancing this technology, we will see a more progressive raw material base, fundamental solutions to historic hurdles and coatings that exceed the potential of current technologies."

Industrial Coatings
While automotive coatings might be one of the latest segments to embrace radiation-cured technologies, IAL Consultants, London, England, reports that the leading application for UV curing systems in Europe is industrial coatings with a 59% marketshare.

"As a whole, the general industrial market segment presents the most opportunities for rad-cure technology," said Mr. Bradford of BASF. "Although this large market segment is very diverse, a few well-designed products can meet the needs of many end-users. UV technology allows the end-user to remove temperature and substrate from the equation, and target specific properties and performance. This means that one product can fit in a variety of applications."

"There are so many opportunities for rad-cure technology to fit into industrial applications," said Steve Lapin, vice president, technical director, Northwest Coatings. "This is only the beginning."

UV Coatings Limited has made progress in a segment where others thought rad-cure wouldn't fit. "We have found good opportunities for full opaque metal coatings with good corrosion resistance, a market for which the general industry consensus was that UV would not work, but with proper formulations it does," said Dr. Curatol.

Mr. Lapin said one challenge facing manufacturers of rad-cure coatings for the industrial market is "getting good adhesion to non-porous substrates. It's much better than years ago, but an area where improvements would be worthwhile."

Packaging
From food products to cans and containers, packaging also presents opportunities for rad-cure coatings.

ICI's packaging coatings group reports that demand continues to rise for rad-cure coatings in the packaging arena. "As long as the end customer demands quality packaging then there are good opportunities in most of our chosen markets," said Ray Good, international technology director, ICI Packaging Coatings. "Special effect UV coatings such as pearl and interference effects are becoming more popular in enhancing the external decoration."

There has been some concern, though, regarding rad-cure and some segments of the packaging market. "In certain food packaging applications, there is a concern with odor," said Mr. Lapin of Northwest Coatings. "UV/EB technology is widely used in food packaging, but certain segments are very cautious about using rad-cure coatings in food packaging applications."

DuPont Performance Coatings has introduced UV-GL-5310, a new type of odorless, food-approved and high glossy UV topcoats suitable for food packaging, flexible packaging and folding carton applications. According to DuPont, this solvent-free 1K material does not require mixing, does not have a limited potlife and has safe application characteristics.

"Its optimum flow and brilliant characteristics make the new UV lacquer a low-cost recyclable alternative to gloss foil lamination," according to DuPont. "Fully cured immediately, it enables a quick quality control."

Market News
As rad-cure coatings continue to gain recognition in industry and find applications in more markets, coatings manufacturers are making moves to strengthen their position in this growing market

Dymax has acquired Bomar Specialty Chemicals, a manufacturer of oligomers for furniture and flooring applications. According to the company, Bomar's oligomers are used in formulations that Dymax makes for the assembly industry.

BASF manufactured its first UV-cured coatings in the early 1970's, and continues to focus on taking the technology to the next level. "Although BASF has not made any acquisitions related to rad-cure coatings, the company continues to approach the global market with technology and information transfer on a global basis," said Mr. Bradford. "In Asia, our BASF NOF Coatings joint venture in Japan is taking a strategically important and necessary step forward for us in UV coatings. Supplementing our automotive and industrial coatings product portfolio with the powder coatings, coil coatings, plastic coatings and UV coatings of NOF are a perfect fit."

Last fall UV Coatings Limited earned ISO 9001 certification. According to the company, the investment in time and manpower to obtain this level of quality continues to demonstrate the dedication of the company to customer satisfaction, continuous improvement and providing superior coatings products to the marketplace.

To strengthen the company's position in the rad-cure market, Northwest Coatings recently completed a major plant expansion that doubled its capacity for UV/EB products.

Fact or Fiction?
It can take only a very short time for rumors to start, but years to dispel them. Misconceptions continue to be one reason end-users are reluctant to invest in the equipment and make the switch to rad-cure coatings.

"There are a lot of misconceptions about UV coatings," said Mr. Raymont of EIT. "When an end-user works with formulators, substrate suppliers, equipment manufacturers and attaches process control, the transition can be much easier."

Problems encountered years before continue to plague the rad-cure industry. "The main hurdle that UV/EB coatings still have to overcome in order to challenge waterborne and solventborne coatings for marketshare is the perception of the marketplace that UV/EB won't work in many applications because it may have been tried in its infancy," said Dr. Curatolo of UV Coatings Limited. "There are now more raw materials available that are safer and easier to use than the first available raw materials, with improved capabilities to satisfy challenging applications."

In a phone survey conducted by Rad-Tech International last year, Mr. Cohen said both manufacturers and suppliers identified perception as the biggest hurdle standing in the way of opportunities for radiation-cured coatings. "End-users do not realize how widespread the technology is," he said. "Several years ago the technology wasn't as developed as it is now. The misconceptions out there now are based on past experience with the technology."

Helping the cause is the continued work of Rad-Tech, but Mr. Cohen said the association can only do so much. While Rad-Tech membership is growing, he said "there are a still a lot of people who do not understand the concept of UV/EB curing. It is a completely different way to cure coatings."

The Cost Factor
No one disputes that the cost of materials used for manufacturing radiation-cured coatings are higher compared to other coatings technologies, but prices are coming down. Manufacturers and suppliers both emphasize that end-users should also look at total applied cost when considering a switch to UV/EB.

"Per pound UV coatings may cost more, but you need to consider the complete business model," said Mr. Raymont. "UV coatings systems can be less expensive than other conventional technologies."

Sometimes, incorporating rad-cure technology into their portfolio might be a lot easier than end-users realize. "In some instances, adapting a line to UV may seem like a major retrofit, but ends up being a very economical and relatively simple addition of a UV station to an existing line," said Kevin Berger, market manager, energy cure chemicals, Cognis Corporation.

As demand for rad-cure continues to grow, there are indications that prices will continue to fall. "Costs will come down as more companies supply the industry," said Mr. Cohen. "You must factor in productivity and applied cost when comparing the cost to that of conventional coatings."

To help end-users become more familiar with rad-cure coatings, Star Technology has taken an approach that Mr. Starkey compared to Kodak's philosophy of selling cameras at cost in the 1950s to create a market for film. "Star Technology actually offered a lab-sized UV cure flood lamp at approximately $1,500, virtually our cost, just to put customers into the position of being able to cure UV products on a small scale in their labs or prototype shops. Once they see the advantages of UV, many will make the jump to purchasing production quality curing lamps," said Mr. Starkey.

News from Suppliers
As more end-users convert to UV/EB coatings systems, coatings manufacturers will look to both raw material and equipment suppliers for products that will help them improve product performance and meet their customers' demands.

Tego has introduced a range of different additives for low VOC coatings. TEGO Rad 2250, a crosslinkable additive for improved flow and slip properties, is suitable for plastic and wood coatings. "Rad 2250 improves scratch resistance without adverse effect on a film's optical clarity," said Mr. Yosh.

Designed for wood and industrial coatings, Tego Glide 432 "exhibits excellent flow and leveling properties without recoatability problems," said Mr. Yosh. Another new additive from Tego is LA-D 490, which gives formulators uniform pigment wetting throughout their coatings, according to the company.

Among the new introductions from Ciba for rad-cure applications are Irgacure 819 DW, a stable dispersion for waterborne, UV and daylight curing systems, and the Irgacure 2000 blend series for the curing of white/colored pigmented systems, putties and UV stabilized clearcoats.

Mr. Berner estimates that about seven percent of Ciba's sales are reinvested into rad-cure R&D. Among future research projects being worked on are the "radiation curing of pigmented materials that combine our know how in pigments and additives; low emission, low odor photoinitiators for the packaging area; and low volatile photoinitiators for UV powder coatings," he said.

ChemFirst Fine Chemicals (CFC) has commercialized BD initiators, its new series of photoinitiators. FirstCure BD-1 and FirstCure BD-3 can be used for curing clearcoats. According to the company, the development of the BD initiators is a breakthrough in photoinitiator development because CFC researchers have shown, for the first time in the UV curing field, that an abstraction type indicator like BD-3 can exhibit higher efficiency than cleavage type initiators.

Eastman Chemical Company's CAP UV100 resin was developed for the aesthetic and performance requirements of the global UV cure market. According to Eastman, UV cured coatings containing CAP UV100 exhibit very good adhesion as well as chemical and scratch resistance. The company added that because CAP UV100 completely crosslinks into the film, finishers can now obtain the viscosity control they need without adversely affecting the final properties of the cured film.

Cognis has also developed a number of new products for the energy cure market. Photomer 4361 and Photomer 4362 offer good flexibility as well as improved pigment wetting for better color development, according to the company. Cognis has designed Photomer 5806 specifically for use in pigmented systems such as UV flushes where it provides fast water displacement, excellent pigment wetting and flush shelf stability. "Given its unique rheology, incorporating Photomer 5806 into UV/EB coatings can eliminate the need for non-reactive fillers sometimes used to build body and viscosity," said Mr. Berger.

Also new from Cognis is Photomer 3691, a low viscosity epoxy diacrylate oligomer designed for water-based UV applications. "It is more flexible than the industry standard aromatic bisphenol-A based epoxy acrylates but can be diluted with up to 30% water," said Mr. Berger. "It can be used in ink jet inks, and EB coatings requiring low extractables. This hydroxy functional oligomer can also be used in hybrid UV- 2K urethane coatings system."

ISP has introduced Gafgard radiation-curable coatings, 100% solids vinyllactam-polyacrylate based formulations that can be cured using either UV or EB technology. Possible applications include credit card magnetic strips, interior solar polyester films and as abrasion resistant clear coatings for polycarbonate lenses. The cured coating is optically clear and issued to impart hardness and a high level of abrasion, solvent and stain resistance, according to the company.

EIT has developed the Palm Probe, a new measurement tool designed specially for UV applications where it is tough to use standard radiometers, according to Mr. Raymont. The light guide of the Palm Probe has a non-conductive coating for operator safety. "This instrument rounds out our product line and more easily addresses UV measurement and process control on web and flexo systems," said Mr. Raymont.

New from IST America is the IST UV-S3 sensor, a new stationery UV energy measuring device that continuously measures and controls the output of UV energy on converting equipment and printing presses.

Break out the Shades: Rad-Cure's Future Looks Bright
Before rad-cure coatings can begin to challenge proven technologies for marketshare, there are areas where continued development of the technology is needed.

"Limits to rad-cure are of course the curing of three-dimensional parts because the UV light will have problems accessing shadow areas," said Mr. Berner of Ciba. "On the other hand there is a significant amount of work ongoing to combine conventional and rad-cure technology in so called hybrid curing systems, which combine positive elements of both technologies and overcome the three-dimensional cure issue. Very often also waterborne or powder technology are not competing technologies but rather complementary. Thus waterborne UV curing materials are increasingly used in the area of parquet coatings."

"Despite recent advances in photoinitiator and energy sources such as improved UV lamps and less expensive EB machines, the challenges associated with curing thick films, coating and curing odd shaped objects or obtaining near-zero extractables which is essential for direct food contact use, remain more difficult than those involved with water-based or solvent based systems," said Mr. Narayan of Cognis.

A few companies offered a preview of what's to come in the rad-cure arena.

"We feel that the specialty wood coatings market holds the most promise for volume of use at this time," said Mr. Starkey of Star Technology. "One of our largest R&D efforts is in UV wood coatings. We are working on products that exhibit high slip and mar resistance, but still have good impact and scratch resistance."

Northwest Coatings continues to focus R&D efforts on the flexible packaging segment. "This is one of the largest growth areas in packaging," said Mr. Lapin. "UV/EB technology doesn't have much penetration in this market and there are strong opportunities for growth in this segment."

But technological improvements alone cannot solve the technology's major obstacle, convincing end-users to give rad-cure coatings a try.

"Many UV installations happen when new plants or new lines go in, or when there is a champion willing to keep pushing for the change," said Susan Mitchell, business development manager, Fusion UV. "Nobody likes change, and often switching to rad-cure technology is seen as a risk. However I like to point out to people that not changing is also a risk, just a different one."

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