Method of treating surface of metal base metallic material treated by the surface treatment method and method of coating the metallic material

摘要

A metal surface treatment method for a metal base material in order to improve the uniformity of a cathodic electrodeposition coating film, the method including: a surface treatment step for forming a chemical conversion film on a metal base material by contacting the metal base material with a metal surface treatment composition including zirconium and/or titanium ions and an adhesive imparting agent characterized in being at least one selected from the group consisting of (A) silicon-containing compound, (B) adhesive imparting metal ion, and (C) adhesive imparting resin; and a heating/drying step to heat and dry the metal base material, on which the chemical conversion film is formed, at 60° C. to 190° C. for at least 30 seconds.

主权项

1. A surface treatment method comprising:
contacting a metal base material with a metal surface treatment composition to form a chemical conversion film on the metal base material, the metal surface treatment composition comprising:
(a) at least one of zirconium ions or titanium ions; and(b) at least one adhesive imparting agent selected from the group consisting of (i) a silicon-containing compound which is at least one of a silane coupling agent that is an aminosilane or hydrolysis-polycondensate of the aminosilane, having at least one amino group, (ii) an adhesive imparting metal ion selected from the group consisting of magnesium, zinc, calcium, aluminum, gallium, indium, copper, iron, manganese, nickel, cobalt, silver, and tin, and (iii) an adhesive imparting resin that is a polyamine compound; and contacting the metal base material on which the chemical conversion film has been formed with water under atmospheric pressure or pressurized conditions at 60° C. to 120° C. for 2 seconds to 600 seconds; and applying a cathodic electrodeposition coating film onto fine portions of the metal base material with curves and bag portions, wherein the total amount of the zirconium and titanium ions in the metal surface treatment composition is 10 ppm to 10000 ppm based on metal element content, wherein the total amount of the aminosilane, the hydrolysis-polycondensate of the aminosilane, or both, in the metal surface treatment compositions ranges from 1 ppm to 2000 ppm based on silicon element content, and the ratio of the total amount of zirconium and titanium elements to the total amount of silicon element contained in the aminosilane, the hydrolysis-polycondensate of the aminosilane, or both, is 0.5 to 500, and wherein the adhesive imparting metal ion is present in an amount of from 1 ppm to 5000 ppm in the metal surface treatment composition.