Isocyanate-Free Polyurethane Technology for Automotive Refinish Applications

By Nahrain Kamber, John Argyropoulos, Paul Popa, Brian Wood, Yanxiang Li, Rebecca Ortiz, David Pierce,

Two-component polyurethanes are used in a variety of industrial coating applications due to their excellent weatherability, toughness, and chemical resistance. When formulated as ambient-cured systems, traditional two-component polyurethanes typically must balance cure speed for pot life. This article describes automotive refinish applications for a novel ambient-cure, two-component isocyanate- free polyurethane coating technology based on the reaction of polycarbamates with polyaldehydes.

One significant benefit is the ability to decouple pot life from cure speed, facilitating the development of coating formulations with longer pot life without sacrificing fast hardness development and quick dry time. For the applicator, these attributes can offer faster return to service, higher production throughput, and less material waste. Additional coating benefits, including good chemical and humidity resistance and fast sandability, are described for automotive refinish primer surfacer coatings at conventional and low-VOC levels. Examples of isocyanate-free PU clearcoats are also presented.