Thermosetting high solid coating composition

Claim 1

A thermosetting high solid coating composition usable for spray coating at a temperature below 70° C. which comprises: A. a mixture of: a. 80 to 60 parts by weight of alkyd resin having a fatty acid content of 10 to 20% by weight and a phenyl group content of 10 to 25% by weight, and further the hydroxyl group equivalent and dibasic acid ratio (the molar ratio of dibasic acid/polyhydric alcohol) of said resin existing on or within the four sides of the tetragon as defined by four points of (300, 0.700), (300, 0.775), (500, 0.775) and (500, 0.850) on a coordinate of said hydroxyl group equivalent as abscissa and said dibasic acid ratio as ordinate; and b. 20 to 40 parts by weight of melamine resin comprising hexakisalkoxymethylmelamine of the formula: ##STR2## in which 2 to 6 of R's are alkyl groups having each 2 to 4 carbon atoms and the remainder are methyl groups, and an amount up to less than one half of said hexakisalkoxymethylmelamine of another melamine resin containing not more than an average of 5.5 moles combined formaldehyde per one mole of melamine resin and being modified with alcohols of 1 to 4 carbon atoms; B. 0.05 to 1.00 parts by weight of aliphatic or aromatic sulfonic acid or its amine salt per 100 parts of said mixture; and C. 80 to 20 parts by weight of solvent per 100 parts by weight of said mixture, said solvent being able to dissolve simultaneously the components in said mixture.