Patent ID: 6372365
Filing Date: 2002-04-16
Classification: B05D,C23C,Y10T

Abstract:
A resin-coated Alâ€”Zn alloy coated steel sheet, which is composed of an Alâ€”Zn alloy coated steel sheet as a substrate and a resin film formed on said substrate by use of a chromate containing resin composition, and produced by the steps of:compounding (A) a silane coupling agent having amino group, (B) chromium ion, and (C) at least one alcohol selected from the group consisting of trihydric alcohol and dihydric alcohol having a carbon number of 2 to 3 into (D) an acrylic polymer resin emulsion including carboxyl group and glycidyl group and having an acid value of 10 to 60; adjusting a pH of the resultant mixture within a pH range of 7 to 9 to obtain said chromate containing resin composition; applying said chromate containing resin composition on said substrate to form an applied film; and drying said applied film to obtain said resin film, wherein a compounding amount of said silane coupling agent (A) is within a range of 0.5 to 3.0 wt % with respect to a resin solid component of said acrylic polymer resin emulsion (D), a compounding amount of said alcohol (C) is within a range of 25 to 150 wt % with respect to the chromium ion, the weight of said resin film is within a range of 0.5 to 3.0 g/m2, and the content of the chromium ion (B) in said resin film is within a range of 5 to 50 mg/m2.