Patent ID: 7875363

Claim:
A surface-treated galvanized steel sheet, comprising: a steel sheet; a zinc coating disposed on the steel sheet; and a film disposed on the zinc coating, the film having a thickness in the range of 0.01 to 3 μm and containing a resin compound (A) represented by a general formula (I) and a cationic urethane resin (B) having a quaternary ammonium salt group at an A:B mass ratio of from 7:3 to 4:6, 2% to 20% by mass of vanadium compound (C), 2% to 20% by mass of zirconium compound (D), 5% to 30% by mass of compound (E) having a phosphate group, and 0.1% to 5% by mass of at least one acid compound (F) selected from the group consisting of hydrofluoric acid, acetic acid, nitric acid, sulfuric acid, and salts thereof, on the basis of the total amount of A and B, wherein said formula (I) is as follows: wherein Y 1 and Y 2 on benzene rings independently represent hydrogen or a Z group represented by a general formula (II) or a general formula (III), and the mean number of substituent Z groups per benzene ring is in the range of 0.2 to 1.0, n is an integer in the range of 2 to 50, wherein said formula (II) and said formula (III) are as follows: wherein R 1 , R 2 , R 3 , R 4 , and R 5 independently represent an hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a hydroxyalkyl group having 1 to 10 carbon atoms, and A − represents a hydroxide ion or an acid ion.