FIELD: chemistry.
SUBSTANCE: invention relates to a paint composition providing staining resistance of coated steel sheets. Paint composition comprises a hydroxyl group-containing resin (A), a crosslinking agent (B) which reacts with hydroxyl groups, a radical copolymer (C), and an organosilica sol (D). In this case, the copolymer (B) obtained by radical copolymerization is characterized by a monomer composition with respect to the total weight of the polymerizable monomers, by weight: amide of carboxylic unsaturated acid from 70.0 to 99.8, a radically polymerizable organosiloxane from 0.2 to 10.0 and another radically polymerizable monomer of 0 to 29.8, has a weight average molecular weight of from 1,500 to 15,000, and has a number of hydroxyl groups which is from 10 to 50 mg KOH / g. Organosilica sol (D) is of average particle diameter from 1 to 30 nm, a mass ratio of the solid fraction, represented by {the above-mentioned component (C) + the above-mentioned component (D)} / {the above-mentioned component (A) + the above-mentioned component (B)} is from 0.03 to 0.30, and the mass ratio of the solid fraction represented by {the above-mentioned component (C) / the above-mentioned component (D)} is from 0.2 to 5.0.
EFFECT: technical result is staining resistance both shortly after coating and over a long period of time, and by which the characteristics of the paint film that are required for coated steel sheets, such as water resistance and bending, are satisfactory.
6 cl, 4 tbl, 27 ex
