Inorganic-organic composite-treated zinc-plated steel sheet

A treated zinc-plated steel sheet comprising:

• a zinc-plated steel sheet surface;
• a first coating of zinc phosphate, in a coating weight of 0.3 to 5 g/m2, on the zinc-plated steel sheet surface, and
• a second coating on said first coating, in a coating weight of 0.01 to 1 g/m2, containing 0.1 to 10% by weight of at least one compound (A) selected from the group consisting of thiocarbonyl group-containing compounds, sulfide group-containing compounds and guanidyl group-containing compounds,
• 40 to 80% by weight of an organic resin (B),
• 5 to 30% by weight of a crosslinking agent (C) and
• 10 to 40% by weight of an inorganic corrosion inhibitor (D);
• wherein said organic resin (B) comprises a neutralized ethylene-unsaturated carboxylic acid copolymer (B1) and at least one resin (B2) selected from the group consisting of acrylic resins, polyester resins, polyurethane resins and epoxy resins,
• said copolymer (B1) having a degree of neutralization with an alkali metal of 30 to 90%,
• said resin (B2) having at least one functional group selected from the group consisting of carboxyl, hydroxyl and amide groups,
• and the weight ratio between said copolymer (B1) and said resin (B2) being 100:0 to 20:80.