TRANSIENTLY INHIBITED UREA AND URETHANE-UREA HYBRID COATING COMPOSITIONS

摘要

A solvent borne, curable coating composition includes a resin formed to have an amine functional moiety, and, optionally, a hydroxyl functional compound; at least one polyisocyanate, and; at least one volatile, salt-forming organic acid and an inert solvent. The compositions may further include an organometallic catalyst. It is believed that the volatile organic acid temporarily drives the formation of amine salts in the composition, thereby inhibiting amine/isocyanate crosslinking, and, where an organometallic catalyst is present, inhibits catalysis. Both of these inhibitory effects are reversed upon acid evaporation, which may substantially occur after the composition has been applied to a substrate. The delay in crosslinking achieved by use of the acid, however, may facilitate more complete evaporation of solvents from the coating, resulting in improved coating properties.