Rad-Cure Raw Materials & Equipment Update

When come it comes to formulating quality coatings, you must start with the basics. Quality raw materials and equipment are key foundations for success-especially in a growing market that demands performance such as the rad-cure industry. A coatings formulator needs to be sure its technology will meet, if not exceed, the demands of its customers. And if it doesn't, they'll know.

"Coatings suppliers produce products that are QC checked throughout the process and are generally very, very consistent day-to-day or batch-to batch," said Jim Raymont, director, instruments markets, EIT. "When conditions change at their coatings, the coatings supplier is usually the first one to get a call complaining that the coating is 'bad' and not working this time. How the coatings supplier deals with and responds to these calls determines if they retain and flourish with the customer."

There are definite opportunities to flourish in the rad-cure market for many coatings companies. Although double-digit growth rates are no longer the norm, the rad-cure market continues to post numbers coatings companies want to see. According to a recent survey from RadTech International North America, market growth over the next three years is projected to reach six to nine percent. IAL Consultants, London, reports that demand for the main curable chemicals-such as monomers, oligomers and photoinitiators-used in UV, EB and cationic radiation curing systems was estimated to be 126 million lbs. (57,060 tons) in 2001.

There are market segments in which rad-cure has already established itself as a proven technology-fiber optics, CDs/DVDs, overprint varnish on paper, coated labels, RTA furniture and pre-finished hardwood flooring-as well as areas where the technology is just now breaking in and becoming a choice with finished product manufacturers.

"There are a number of applications where UV/EB is establishing a foothold and industry penetration is expected to grow significantly,"' said DSM Desotech's James Reese, who is also RadTech president. According to RadTech, growth areas include UV powders, PSAs, non-food can coatings, laminating and structural adhesives and release coatings among others. According to RadTech's recent poll of its membership, coatings for plastics is another area that, although it is in its infancy, shows the greatest probability for widespread success for UV/EB applications by 2007.

It is growth areas like that which attract attention from coatings makers and their suppliers. Recent industry advances noted by RadTech's membership suggest that one of the major factors driving growth of the market is better raw materials.

"R&D efforts for new products and innovative curing technologies are targeted towards new applications, such as coatings for exterior use, coatings for metal decoration, automotive and 3D applications with sprayable coatings," said Werner Peter, business director, coating, performance chemicals, BASF Corp.

Some companies are taking their expertise from one area of the market and expanding it to other segments. For example, Clariant is developing waxes as additives for coatings and printing inks and applying these improvements to the coatings market, according to Ernst Krendlinger, research and development manager-waxes, Clariant Pigments & Additives, and Romesh Kumar, a specialist in pigments with Clariant. Clariant's range includes TP Ceridust 5091, a micronized ester wax with an average particle size of 9.5 �m, that can give UV-curable coatings a matte finish.

New Product Technologies
New technologies continue to come from the lab and fabrication shops of many suppliers.

In the industrial coatings area, UCB's R&D efforts have been focused on the creation of higher scratch and abrasion resistant systems; lower viscosity systems for spray and vacuum applied coatings; and UV curable polyurethane dispersions. The company reports that it is continuing the process of introducing the Raylok line of engineered systems for industrial applications. The line has been designed to deliver higher performance in the areas of scratch, abrasion, chemical and weather resistance to markets that include wood flooring and automotive paints.

In addition, capacity expansion at UCB's North August, SC plant will be completed by the end of the third quarter and a new monomer plant in Shanghai, China is now in full production.

Rahn USA, Aurora, IL, has a new UV curable oligomer that is intended for use in low gloss UV inks and coatings. In combination with suitable fillers and additives, gloss levels of 10% can be achieved in 100% solids systems while maintaining a low viscosity. Other film properties delivered with this low viscosity oligomer include good scratch resistance, flexibility and non-yellowing, according to the company. Dependent on filler selection, soft-touch films can be produced. Good adhesion to PP and PE has been determined, according to Rahn.

Morflex, Inc. offers VEctomer 1312 oligomer, a new vinyl ether performance modifier. This oligomer has an average of four vinyl functional moieties and a typical molecular weight of ~1800. According to Morflex, its viscosity is lower for an oligomer, i.e., ~4300 cps range at 27�C. VEctomer 1312 shows exceptional UV coatings enhancement when used with acrylate or epoxy UV formulations and improves flexibility, hardness, impact, water and abrasion resistance.

Fusion UV Systems, Inc. has added three new UV curing chambers for curing of small parts and assemblies. The company says that they are ideal for uniform curing in lab and pilot plant applications as well in light volume manufacturing. The DRE-3 is designed for use with the PowerCure 3 UV curing system. Made of a see-though acrylic that shields employees from UV rays, the chamber comes standard with an exposure shelf that can be combined to raise the sample two to six inches from the bottom.

Fusion UV's DRE6-110 is a curing chamber built for the PowerCure 3 and all six-inch lamps models. Made of metal, it features an adjustable sample stage as well as an optional turntable and exposure timer. Deluxe Model DRE6/10-10 is available with the company's six- and 10-inch microwave-powered UV lamp systems. The unit features heat shielding, an adjustable speed turntable and a shielded viewing port.

Also on the equipment side, EIT now offers UV PowerMap (four-channel) and Map Plus (single channel) advanced self-contained UV profiling systems that measure and store UV energy, UV irradiance and temperature information received in a UV curing system.

Following its merger with Union Carbide, Dow Chemical now offers UV coatings formulators Cyracure cycloaliphatic epoxides for use in high-performance cationic UV cure applications. Performance advantages of these resins include good chemical resistance, excellent gloss, good color stability and good weathering characteristics. Processing advantages include fast cure response, broad formulating latitude and minimization VOC usage, according to the company.

Ashland Specialty Chemicals has developed a patented technology to provide self-initiating, radiation-curing resins for UV coatings. Novacure resins have been developed for use without the need for UV photoinitiators, according to the company.

According to Godwin Berner, head global business line coatings, coating effects segment, Ciba Specialty Chemicals is currently developing a new photoinitiator with a good cost/performance ratio, good solubility and high dissolving speed in major components of UV-curable formulations, low emission, migration, extractability (including photo products) and an initial color before and after cure that is within acceptable limits for clears.

Companies will continue to focus R&D efforts in this area to match the growth prospects the market holds. As Mr. Kumar of Clariant said, "This is a young, developing technology where there is a great deal of room to grow and change in the future.
 

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