Method for making 1,2,4-Triazole blocked polyisocyanate crosslinkers, coating compositions and coatings prepared therefrom

摘要

A solvent-free method for making a powder crosslinker for a polyurethane powder coating composition by reacting (a) certain bis(4-isocyanatocyclohexyl) methane derivatives (or mixtures of bis(4-isocyanatocyclohexyl) methane derivatives) and (b) 1,2,4-triazole under conditions which produce a processing melt that is entirely a liquid at a temperature of about 150°C or less. The invention is also directed to a polyurethane powder coating composition and coatings made with the powder crosslinker.