Abstract: Disclosed herein is a paint composition comprising a carboxyl group containing resin comprising two or more carboxyl groups per molecule, having an acid number of from 100 to 300 mgKOH/g and a weight average molecular weight of from 2,000 to 30,000, obtained by the copolymerization of a carboxyl group containing radically polymerizable monomer and another radically polymerizable monomer, wherein the carboxyl group containing resin comprises 5 to 50 weight percent of structural units based on a lactone compound, based on resin solids; an epoxy group containing resin, comprising two or more epoxy groups per molecule; an ultraviolet absorber; and a light stabilizer having a pKb value of at least 9; wherein the molar ratio of the carboxyl groups of the carboxyl group containing resin to the epoxy groups of the epoxy group containing resin is 3:1 to 1:3.

Abstract: Disclosed herein is a clear paint composition, comprising (A) an acrylic copolymer comprising from 35 to 50 wt % ?-caprolactone structural units, based on the resin solid fraction, and wherein the hydroxyl number is from 200 to 340 mgKOH/g and the weight average molecular weight is from 5,000 to 15,000 and (B) a non-yellowing type polyisocyanate compound, wherein the isocyanate group of the (B) component is included in a proportion of from 0.5 to 2 equivalents per 1 equivalent of hydroxyl group of the (A) component, wherein the Young's modulus of the hardened paint film obtained from said paint composition is not more than 1.5 Pa, wherein the molecular weight of intercrosslinking of the cured coating film (Mc) is not more than 350 g/mol, and wherein the glass transition temperature (Tg) of the hardened paint film is at least 65° C.

Abstract: Disclosed herein is a heat-hardenable paint composition comprising a base resin, wherein the base resin comprises (A) a lactone modified resin comprising hydroxyl groups, wherein 20 to 70 weight percent of the structural units are based on the lactone compound, and the hydroxyl group value is from 50 to 400 mgKOH/g, and (B) an acrylic resin comprising hydroxyl groups and cyclic structures, wherein 10 to 80 weight percent of structural units are based on a radically polymerizable monomer comprising a cyclic structure, the hydroxyl group value is from 50 to 150 mgKOH/g, and the crosslinking resin is an isocyanate compound, wherein the weight ratio of the solid fractions of (A):(B) in the base resin is from 95:5 to 20:80.

Abstract: Disclosed herein is a paint composition comprising a hydroxyl group containing resin (A), comprising structural units based on 2,2-dimethylolalkanoic acid, having a hydroxyl group value of from 200 to 400 mgKOH/g, and comprising less than 25 weight % in the resin solid fraction of structural units based on a lactone compound; a hydroxyl group containing resin (B), having a hydroxyl group value from 50 to 200 mgKOH/g, and comprising from 25 to 75 weight % in the resin solid fraction of structural units based on a lactone compound; and a crosslinking agent (C) comprising at least two OH-reactive functional groups per molecule; wherein the resin solid fraction weight ratio (A)/(B) of the hydroxyl group containing resin (A) and the hydroxyl group containing resin (B) is from 90/10 to 10/90.