Surface treatment agent of the zinc-based plating for steel and surface treated zinc-plated steel sheet

摘要

PROBLEM TO BE SOLVED: To provide a surface treatment agent with which stable surface treatment can be performed and a chromium-free surface treated galvanized steel sheet having excellent corrosion resistance, electrical conductivity and workability can be obtained.;SOLUTION: The surface treatment agent is an aqueous solution comprising: (a) one or more kinds of metal ions selected from Al, Mn, Mg, V and Zn; (b) phosphoric acids; (c) organic resins; and (d) one or more kinds selected from amines, the derivatives thereof, aminopolycarboxylic acids and amino acids by prescribed ratio, and having a pH of 1 to 4 and free acidity of 3 to 20 expressed in terms of 0.1 normal sodium hydroxide.;COPYRIGHT: (C)2008,JPO&INPIT