Surface-treated steel sheet

Abstract

A surface-treated steel sheet including a Zn—Al—Mg-based coated steel sheet having an amount of coating weight per one surface, of from 20 to 60 g/m2, and a paint film placed on at least one main surface of the Zn—Al—Mg-based coated steel sheet, in which the paint film includes a binder resin, a doped zinc oxide particle, and a rust inhibitor, an average thickness of the paint film is from 0.5 to 3 μm, an average particle size of the doped zinc oxide particle is from 0.1 to 2 μm, a content of the doped zinc oxide particle is from 20 to 40% by mass with respect to the paint film, and a content of an inorganic substance other than a Zn-containing compound in the paint film is from 0 to 1% by mass with respect to the paint film.

Dependencies are inferred from the claim text.