| abstract |
This invention provides a highly corrosion-resistant, colored thin film-coated steel sheet having excellent press-processability and spot-weldability, which comprises a plated steel sheet, a first layer of a sparingly soluble chromate film formed on surface(s) of the plated steel sheet and having a water soluble content of 1 to 30%, a Cr6+/Cr3+ ratio of 0.01 to 1.0 and a total chromium build-up of 10 to 150 mg/m2 on one surface, and a second layer of a 0.3 to 5 mu thick solid coating film formed of an organic solvent-type coating composition, the solid coating film being comprised, based on the weight of the nonvolatile content, of (a) a urethanated epoxy ester resin having a number average molecular weight of 300 to 100,000: 30 to 90%, (b) a hydrophilic polyamide resin having a polymerization degree of 50 to 1,000: 5 to 40%, (c) a silica powder having an average particle diameter of 1 to 100 mu m: 5 to 40%, (d) a lubricant: 1 to 20%, and (e) at least one member selected from a group consisting of inorganic, and insoluble azo-type, azolake-type or phthalocyanine-type organic pigments having an average particle diameter of 0.05 to 5 mu m: 0.1 to 20%. |