Patent ID: 7339017

Claim:
An acryl-modified polyester resin composition for coating a pre-coated metal steel sheet, comprising: an acryl-modified polyester resin produced by a polymerization of a polyester resin intermediate of formula (1) and an acryl monomer: R—CH 2 —O—CO—CH═CH—X (1) wherein R represents a polyester polymer residue, and X represents a methyl or carboxylic group, and wherein the polyester resin intermediate has a hydroxyl value of about 1 to 20 mgKOH/g and an acid value of 15 to 30 mgKOH/g; and a solvent comprising cyclohexanone, isophorone, or a combination thereof, wherein the acryl-modified polyester resin composition has a Gardener bubble viscosity of X to Z3 and a paint film comprising the acryl-modified polyester resin composition has a pencil hardness of H or harder according to NCCA-II-12.