JPS6321691B

PURPOSE:To lower the baking temperature of polyurethane polymer paint containing a blocked isocyanate, by employing a specified organotin compound as a catalyst. CONSTITUTION:A monoalkyltin monocarboxylate salt, e.g., monobutyltin 2-ethylhexanoate, is employed as a dissociation catalyst for lowering the dissociation temperature of a blocked isocyanate compound. That is, a mixture containing an active hydrogen-containing compound, e.g., polyether-polyol, and a blocked isocyanate compound, e.g., a reaction product between tolylene diisocyanate and ethylene glycol is mixed with about 0.1-5%, based on active hydrogen-containing compound, monoalkyltin monocarboxylate salt. Next, the resulting paint is applied to a substrate, e.g., iron plate, and cured by baking to form a polyurethane polymer film.