A novel tetrahydroxy oligomer crosslinkable with amine-aldehyde resins to form a coating composition adapted for use as an automotove topcoat and which upon curing forms a hard, glossy, coating with outstanding durability and excellent resistance to solvents and water. The coating composition comprises:
(A) a tetrahydroxy oligomer having a number average (Mn) molecular weight of between about 600-2000 and being the reaction product of:
(i) an ester containing pendant hydroxyl and carboxyl functionality and being made by reacting:
(a) a C3-C10 aliphatic diol, and
(b) an alkyl hexahydrophthalic anhydride, wherein (a) and (b) are combined in the reaction mixture in an amount sufficient to allow reaction in about a 1:1 molar ratio: and
(ii) a diepoxide having a number average molecular weight between about 130-1500, wherein (i) and (ii) are combined in the reaction mixture in an amount sufficient to allow reaction in about a 2:1 molar ratio,
(B) an amine aldehyde or polyisocyanate crosslinking agent; and
(C) optionally a hydroxyl functional additive.
一种新型四羟基低聚物,可与胺-醛
树脂交联形成一种涂料组合物,适合用作汽车面漆,固化后形成坚硬、有光泽的涂层,具有出色的耐久性和优异的耐溶剂和耐
水性。该涂料组合物包括
(A) 四羟基低聚物,其数均(Mn)分子量在约 600-2000 之间,是下列物质的反应产物
(i) 含有羟基和羧基官能团的酯,通过以下反应制得:
(a) C3-C10 脂肪族二元醇,和
(b) 烷基六氢
邻苯二甲酸酐,其中(a)和(b)在反应混合物中的结合量足以使反应以大约 1:1 的摩尔比进行:和
(ii) 平均分子量在 130-1500 之间的二
环氧化物,其中(i)和(ii)在反应混合物中的混合 量足以使反应以大约 2:1 的摩尔比进行、
(B) 一种胺醛或多
异氰酸酯交联剂;以及
(C) 可选的羟基官能添加剂。