SURFACE TREATING AGENT FOR METAL

摘要

PROBLEM TO BE SOLVED: To provide a surface treatment method capable of forming a surface treatment coating provided with both of high primary rust-prevention property and coating adhesiveness on the surface of an aluminum die-cast member without including harmful hexavalent chromium traditionally used. SOLUTION: By using an aqueous surface treating agent which includes a cationic amino group-containing aqueous epoxy resin and an anionic aqueous urethane resin at a specified ratio of both resins and in the specified pH range, the aluminum die-cast member is subjected to surface treatment and thereby a resin coating is formed and dried. COPYRIGHT: (C)2007,JPO&INPIT