New polyester-urethane system for high performance exterior powder coatings: chemistry and applications

摘要

The main objective of the coatings Industry is to reduce the volatile organic compounds (VOC) emission to the atmosphere. Powder coatings technology continues to grow, giving the Paint Industry an environmentally friendly alternative. This paper persents a novel system for weather-stable thermally curing polyurethane powder coatings. This new system is based on solid blocked hexamethylene-diisocyanate trimer (HDT) and special hydroxylated polyesters and catalysts. The HDT is blocked by a proprietary agent based on p-hydroxybenzoic acid derivatives partly esterified, a well-known non-toxic chemicals, used in the food industry.