| 摘要 |
PROBLEM TO BE SOLVED: To provide an aluminum-made cap which has a coating film having excellent adhesion and excellent corrosion resistance after formation and contains a large amount of a pigment. SOLUTION: A chemical film for treating the above aluminum substrate is a film of chromate phosphate having an amount of Cr deposited of 1-30 mg/m<SP>2</SP>and an amount of C in the surface of≤50 mg/m<SP>2</SP>. On the substrate film, a polymer of an acrylic acid compound having at least one carboxyl group per a weight average molecular weight of 500 and a weight average molecular weight of 1,000-1,000,000 is formed in a deposit amount of 5-5,000 mg/m<SP>2</SP>, and a coating film containing a pigment in an amount of≥5 mass% relative to the dry weight of the substrate film is formed on the substrate film. COPYRIGHT: (C)2008,JPO&INPIT |
