A fast curing, high solids coating composition which upon curing forms a hard, glossy, durable coating exhibiting excellent resistance to solvents and water. The coating composition which is particularly adapted for use as an automotive topcoat, contains greater than about 60 percent by weight of nonvolatile solids and, exclusive of pigments, solvents and other nonreactive components, consists essentially of: (A) a bifunctional copolymer bearing hydroxy functionality and pendent epoxy functionality, having a number average molecular weight (M.sub.n) of between about 1500 and about 10,000 and a glass transition temperature (Tg) of between about -25.degree. C. and about 70.degree.; (B) a reactive catalyst comprising at least one oligomeric hydroxy functional organophosphate ester selected from certain mono- and diesters of phosphoric acid; (C) an amine-aldehyde crosslinking agent; and (D) optionally, a hydroxy functional additive. The oligomeric hydroxy functional organophosphate ester is included in the composition in an amount sufficient to provide between about 0.8 and about 1.5 equivalents of acid functionality for each equivalent of pendent epoxy functionality in copolymer (A), and the amine aldehyde crosslinking agent is included in the composition in an amount sufficient to provide at least about 0.4 equivalents of nitrogen crosslinking functionality for each equivalent of hydroxy functionality included in the composition.
一种快速固化、高固体份涂层组合物,固化后形成一种坚硬、光泽、耐溶剂和
水的持久涂层。该涂层组合物特别适用于用作汽车面漆,含有大于约60%的非挥发性固体份,除
颜料、溶剂和其他非反应性成分外,基本上由以下组成:(A)一种具有羟基功能和悬挂环氧功能的双官能团共聚物,其数均分子量(M.sub.n)介于约1500和约10000之间,
玻璃转移温度(Tg)介于约-25℃和约70℃之间;(B)至少一种寡聚羟基功能有机
磷酸酯反应催化剂,选自某些
磷酸的单酯和双酯;(C)胺-醛
交联剂;以及(D)可选的羟基功能添加剂。寡聚羟基功能有机
磷酸酯以足够的量包含在组合物中,以为共聚物(A)中的每个悬挂环氧功能提供约0.8到约1.5当量的酸功能,并且胺醛
交联剂以足够的量包含在组合物中,以为组合物中包含的每个羟基功能提供至少约0.4当量的氮交联功能。