Surface treatment for metal materials, surface treatment process, and surface- treated metal materials

Abstract

A surface treatment for metal materials obtained by incorporating an anionic water-dispersible resin (A) having a glass transition temperature of 0 DEG C or above and at least one member (B) selected from the group consisting of alkali metal silicates and basic zirconium compounds in water, wherein the alkali metal silicates have M2O / SiO2 mass ratios of 1 / 1000 to 6 / 10 with M being at least one element selected from the group consisting of lithium, sodium and potassium; a surface treatment process; and surface-treated metal materials. The invention provides a chromium-free surface treatment for metal materials which is useful for imparting excellent corrosion resistance, chemical resistance, thermal discoloration resistance and weather resistance to metal materials. Additional incorporation of one or more members selected from among silane coupling agents, vanadium compounds, titanium compounds, organophosphonic acids, polyhydric alcohol phosphates, inorganic acids, salts thereof, metal fluorides, and metal oxides brings about further improvement in the performance of the treatment.

Description

technical field [0001] The present invention relates to a metal surface treatment agent for forming a chromium-free film that can impart corrosion resistance, chemical resistance, thermal discoloration resistance, and weather resistance on the surface of a thin plate coil or a molded product made of metal, and surface treated metal materials. More specifically, the present invention relates to building materials such as automobile parts, home appliances, outer wall materials, and pillars of agricultural plastic greenhouses made of iron, zinc, galvanized steel, galvanized aluminum alloy steel, aluminum, and aluminum alloys. Products, guard rails, sound insulation walls, drainage ditches and other civil engineering products such as sheet coils, formed products, castings, etc. are formed to provide excellent corrosion resistance, chemical resistance, heat discoloration resistance and weather resistance, and does not contain A surface treatment agent for a chromium film, a surfac...

AI Technical Summary

Problems solved by technology

[0010] Japanese Patent Laid-Open No. 2004-183015 and Japanese Patent Laid-Open No. 2003-13252 have the advantage of not containing hexavalent chromium and excellent corrosion resistance. However, in terms of technology that has both thermal discoloration resistance and chemical resistance not enough

[0011] Japanese Patent Application Laid-Open No. 2005-3069094 is a two-stage surface-treated steel sheet formed of upper and lower layers, which is uneconomical, and the corrosion resistance of the damaged part is not sufficient.

Images