High solids coating composition of an acrylic polymer a polyester polyol and an alkylated melamine crosslinking agent

A high solids coating composition comprising at least 40% by weight of a binder of film-forming constituents and up to 60% by weight of a nonaqueous liquid carrier;

• in which the film-forming constituents consist essentially of about
• (1) 10-50% by weight, based on the weight of the binder, of an acrylic polymer consisting essentially of
• (a) 10-50% by weight, based on the weight of the polymer, of styrene, methylmethacrylate or mixtures thereof;
• (b) 30-70% by weight, based on the weight of the polymer, of an alkyl methacrylate, or an alkyl acrylate each having 2-12 carbon atoms in the alkyl group, and
• (c) 15-50% by weight, based on the weight of the polymer, of a hydroxyl alkyl acrylate or methacrylate having 2-4 carbon atoms in the alkyl group;
• and
• the polymer having a number average molecular weight of 500-20,000;
• (2) 10-60% by weight, based on the weight of the binder, of a polyester polyol having a number average molecular weight of 1500 or less and an acid number of 20 or less which is the reaction product of
• (a) neopentyl glycol and at least one other hindered diol containing two methylol groups wherein each methylol group is attached directly to a cycloaliphatic or aromatic structure or to a tertiary carbon atom, the molar ratio of neopentyl glycol to hindered diol being 2:1 to 6:1, and
• (b) a mixture of aromatic and aliphatic dicarboxylic acids wherein the molar ratio of aromatic acid to aliphatic acid is from 1.5:1 to 10:1,
• wherein the molar ratio of (a) to (b) is from 1.3:1 to 1.9:1 and wherein the polyol has a hydroxy content of about 3.0-10.0% by weight;
• (3) 15-40% by weight, based on the weight of the binder, of a fully or partially alkylated melamine formaldehyde crosslinking agent having 1-4 carbon atoms in the alkyl group.