AQUEOUS COMPOSITION FOR METALLIC MATERIAL SURFACE TREATMENT

摘要

PROBLEM TO BE SOLVED: To provide an aqueous composition for metallic material chromate treatment that has a long-term pot life, allows the blending of components having chromic acid resistance and usable in an alkaline state. SOLUTION: This aqueous composition for metallic material surface treatment contains at least one or more kinds of stabilizers selected from polyethylene oxide group-containing water soluble high polymer compounds, containing a chromium compound stabilized by reaction with the stabilizer and also containing a chromate component in which the concentration of the polyethylene oxide group is the equivalent to 10 ten times the total chromium concentration. The aqueous composition for metallic material surface treatment may further be blended with a water-based resin component, and silica and organic wax may moreover be blended therein. The aqueous composition for metallic material surface treatment preferably contains the chromium compound in an optional Cr3+/Cr6+ ratio of <=10 wt.% as the total chromium concentration and also in such a manner that >=30% of the total chromium are the chromium compound brought into reaction with the above stabilizer. The molecular weight of the polyethylene oxide group part in the water soluble high polymer compound is preferably controlled to 400 to 200,000. The aqueous composition for metallic material surface treatment can be used at pH of <=12.