| 摘要 |
A surface treated steel plate, which comprises a steel plate having a plating layer containing a metal selected from zinc and aluminum, a first layer coating film being provided on the steel plate and containing (alpha) 1 to 2000 mg/m2 of silica in terms of SiO2, (beta) 1 to 1000 mg/m2 in total of phosphate groups in terms of P, (gamma) 0.5 to 800 mg/m2 in total of one or more metals selected from Mg, Mn and Al in terms of a metal element and (delta) 0.1 to 50 mg/m2 in total of tetra-valent vanadium compounds in terms of V, and a second layer coating film being provided on the first layer, containing a resin (A) having a functional group selected from an OH group and a COOH group and a rust inhibiting additive (B) selected from (a) a phosphoric acid salt, (b) a silica being ion-exchanged with Ca, (c) molybdic acid salt, (d) (d) silicon oxide and (e) a triazole, a thiol, a thiadiazole, a thiazole and a thiuram, and having a film thickness of 0.1 to 5 mum. The surface treated steel plate is free of hexa-valent chromium, exhibits excellent corrosion resistance, and is excellent in the appearance of a coating film. |
