Surface treatment liquid for zinc-based metal material and method for surface-treating zinc-based metal material

A surface treatment method for a zinc-based metallic material comprising a surface treatment process in which a surface of a zinc-based metallic material is:

• acid cleaned;
• brought into contact with a surface treatment liquid comprising components:
• (A) at least one metallic element selected from the group consisting of Ti, Zr, and Hf;
• and
• (B) at least one compound selected from the group consisting of an imino compound, aminated polysaccharide, amino-modified phenol, and derivatives thereof, wherein
• the total concentration of the metallic elements of said component (A) is 500 to 2000 mg/L, and
• the total concentration of the compounds of said component (B) is 300 to 3000 mg/L
• dried by being heated;
• wherein:
• Component (A) comprises Zr;
• Component (B) comprises 1-propane imine;
• and
• the surface treatment liquid further comprises:
• (C) fluorine in an amount of 5-50 ppm;
• (D) metallic elements Mg, Zn and Cu, wherein total concentration of the metallic elements of said component (D) is from 1000 to 5000 mg/L;
• and
• (E) oxidizers selected from the group consisting of HNO3, HNO2, H2O2, and salts thereof.

A surface treatment method for a zinc-based metallic material comprising:

• cleaning and conversion coating a surface of a zinc-based metallic material by contacting the surface with a surface treatment liquid comprising components:
• (A) at least one metallic element selected from the group consisting of Ti, Zr, and Hf wherein total concentration of the metallic elements of said component (A) is 500 to 2000 mg/L;
• (B) at least one compound selected from the group consisting of an imino compound, aminated polysaccharide, amino-modified phenol, and derivatives thereof wherein total concentration of the compounds of said component (B) is 300 to 3000 mg/L;
• (C) 5-50 ppm fluorine;
• and
• (D) at least one metallic element selected from the group consisting of Mg, Al, Zn, Cu and Co, wherein total concentration of the metallic elements of said component (D) is 500 to 10000 mg/L;
• wherein the surface treatment further comprises at least one surfactant;
• Component (A) comprises Zr;
• and Component (B) comprises 1-propane imine wherein Component (D) comprises Cu and at least one of Ma and Zn.