| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively form a nonchromium film which can exhibit corrosion resistance, weldability and finish coating properties equal to above those of the conventional chromate film on the surface of a galvanized steel sheet. SOLUTION: A treatment solution consisting of an aqueous solution of pH 2.0 to 6.5 which contains a water soluble resin (a) consisting of polymer molecules having a repeated unit expressed by the formula (1), and at least either a titanium compound of a zirconium compound (b), and can contain a silane coupling agent (c), and does not contain chromium is applied, and drying is performed at 50 to 200°C, so that a film is formed; in the formula (1), Y<SB>1</SB>and Y<SB>2</SB>are respectively, individually, a hydrogen atom or a Z group expressed by the following formula (2) or (3); and R<SB>1</SB>, R<SB>2</SB>, R<SB>3</SB>, R<SB>4</SB>and R<SB>5</SB>are respectively, individually, a hydrogen atom, a 1 to 10C alkyl group or a 1 to 10C hydroxyalkyl group, and the mean substitution number of the Z group per benzene ring in the polymer molecules is 0.2 to 1.0. COPYRIGHT: (C)2003,JPO
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