PAINT COMPOSITION WHICH HAS EXCELLENT STAINING RESISTANCE AND PAINT FILMS OBTAINED BY COATING SAME

摘要

[ Problem] To provide a paint composition with which it is possible to obtain paint films which not only provide staining resistance in a short period of time after coating but with which excellent staining resistance is retained over a long period of time, and with which the paint film performance required of coated steel sheets, such as water resistance, bending workability and the like, is satisfactory. [Means of Resolution] The present invention concerns a paint composition which includes 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 which the aforementioned radical copolymer (C) : (a) has a monomer composition, with respect to the total mass of radically polymerizable monomer, of from 70.0 to 99.8 mass % unsaturated carboxylic acid amide, from 0.2 to 10 mass % radically polymerizable organosiloxane and from 0 to 29.8 mass % other radically polymerizable monomer, (b) is of weight average molecular weight from 1,500 to 15,000, and (c) has a hydroxyl group value of from 10 to 50 mgKOH/ g, the aforementioned organosilica sol (D) is of average particle diameter from 1 to 30 nm, the solid fraction mass ratio represented by {the aforementioned (C) component + the aforementioned (D) component } / { the aforementioned (A) component + the aforementioned (B) component} is from 3 to 30% and the solid fraction mass ratio represented by {the aforementioned (C) component / the aforementioned (D) component} is from 0.2 to 5Ø