Aluminum-based metal surface treatment bath, the surface treatment method, the surface treated aluminum product, and surface-treated aluminum cans

摘要

PROBLEM TO BE SOLVED: To form a thin film with high uniformity and to provide a protective film excellent in external appearance, corrosion protecting property, and adhesion of coating film. ;SOLUTION: A surface treatment bath for aluminum type metal, containing 20-80 ppm, expressed in terms of phosphoric acid, of at least one kind among phosphoric acid and its salts, 20-80 ppm, expressed in terms of zirconium, of at least one kind among zirconium salts, at least 1 ppm, expressed in terms of fluorine, of effective fluoride, 50-200 ppm, expressed in terms of phosphorous acid, of at least one kind among phosphorous acid and its salts, and 150-350 ppm, expressed in terms of nitric acid, of at least one kind among nitric acid and its salts and also having pH 2.6 to 3.1, is brought into contact with aluminum products and aluminum cans, by which surface treatment can be applied to the aluminum products and the aluminum cans.;COPYRIGHT: (C)1998,JPO