“Novel” Radiation Curing

Q. I just read some literature regarding UV radiation curing of organic coatings and the benefits it brings to the coatings industry. I would like to know whether this technology can be extended to paints for exterior applications with moderate or high solids and PVCs. More importantly, where can I get a list of companies who supply this novel technology? V.G.

 

A. V. G., where have you been hiding? I wouldn’t call radiation curable coatings novel since they have been commercial for more than 25 years. I’d call that mature. More than 25 years ago, I managed a program that was funded by the U.S. Department of Energy to develop ultraviolet (UV) light radiation curable coating for 3D objects. Before that, we developed UV-curable wire enamels, using a three-story wire tower at the Westinghouse Research Labs. At the same time, there were commercial lines mostly coating flat objects.

Owing to the chemistry of the UV-curable coatings, (though this isn’t a forum for specific formulations), they are certainly useful for exterior applications. The resins and reactive diluents used in their formulation are naturally weather resistant. Since they use low-viscosity reactive diluents in place of solvents, they’re already high-solids materials. They can also be formulated with moderate to high PVCs.

Electron beam radiation (EB) curable coating, another notable process, is also mature. In the past, there was a flurry of activity on these coatings in the automotive industry, and we also investigated these coatings at the labs. It’s against the policy of Painting Clinic to name specific suppliers. However, suppliers are listed under Coatings, radiation curable, on pages 245–246 of the Products Finishing DIRECTORY AND TECHNOLOGY GUIDE. There’s also a trade association, RadTech International North America. Visit www.radtech.org for more specific information on both processes.