CHROMATE-FREE TREATED METAL STRIP HAVING EXCELLENT CORROSION RESISTANCE AND ALKALI RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a chromate-free metallic sheet which does not contain hexavalent chromium, has reduced environmental loads, and has excellent corrosion resistance and alkali resistance in the market. SOLUTION: The surface of a metal or or plated metal strip is provided with a film containing (a) a titanium compound of 10 to 200 mg/m2expressed in terms of titanium, or a zirconium compound of 10 to 200 mg expressed in terms of zirconium, or a titanium compound and a zirconium compound of 10 to 200 mg/m2as the total of the contents expressed in terms of titanium and zirconium, respectively. A film containing (b) a phosphoric compound and (c) a guanidine compound in it is formed. COPYRIGHT: (C)2004,JPO