High-solids polyester and aminoplast coating composition

Claim 1

A coating composition of a film-forming blend and a solvent for the blend wherein the blend is at least 50% by weight of the combined weight of the blend and the solvent and consists essentially of (a) 30-70% by weight, based on the weight of the blend, of a polyester polyol that is the reaction product of (1) pentaerythritol and at least one branched-chain glycol selected from the group consisting of neopentyl glycol, pinacol, and mixtures of these, wherein the molar ratio of glycol to pentaerythritol is from 2:1 to 6:1, (2) an aromatic or aliphatic monocarboxylic acid, or mixtures thereof, having no more than 18 carbon atoms, wherein the molar ratio of monocarboxylic acid to pentaerythritol is from 1:1 to 2.5:1, and (3) a mixture of an aromatic and a aliphatic dicarboxylic acid wherein the molar ratio of aromatic acid to aliphatic acid is from 2:1 to 6:1, wherein the polyol has a hydroxyl content of 5-9% by weight; (b) 4-35% by weight, based on the weight of the blend, of an epichlorohydrin-bisphenol-A epoxy resin, the esterification product of said resin with a monocarboxylic acid, or mixtures of these; and (c) 25-35% by weight, based on the weight of the blend, of an aminoplast resin.