Patent ID: 7875684

Claim:
A thermosetting water-based paint comprising water-dispersible acrylic polymer particles (A), crosslinking agent (B) and pigment (C), wherein: the water-dispersible acrylic polymer particles (A) are obtained by multi-stage emulsion polymerization of a radical polymerizable unsaturated monomeric component using an ammonium salt of a sulfonic acid group-containing compound as a reactive emulsifying agent, the particles have a hydroxyl value within a range of 1-70 mgKOH/g and an acid value within a range of 15-50 mgKOH/g, the radical polymerizable unsaturated monomeric component comprises an amido-containing radical polymerizable unsaturated monomer having at least two radical polymerizable unsaturated groups per molecule, methacrylic acid and a hydroxyl-containing radical polymerizable unsaturated monomer, the content of the amido-containing radical polymerizable unsaturated monomer is within a range of 0.1-5% by weight, based on the total radical polymerizable unsaturated monomeric component, and the water-dispersible acrylic polymer particles (A) have a core/shell structure of which the core part is crosslinked and the shell part is substantially non-crosslinked, wherein the weight ratio of the core part/shell part is within a range of 95/5-50/50.