Patent ID: 7189465

Claim:
A metal product; comprising a steel product and a rust inhibitive coating formed on the steel product by applying a chromium-free metal surface treatment agent and baking the chromium-free metal surface treatment agent at a temperature of 150° C. to 250° C., the chromium-free metal surface treatment agent comprising a silica-based binder solution which consists essentially of the silica-based binder containing a silica component of 8 to 25% by weight to the silica-based binder solution, a dispersed nano-sized titanium dioxide powder of 3 to 25 parts by weight per 100 parts by weight of the silica component contained in the silica-based binder solution and the balance being a solvent of water and/or alcohol, the dispersed nano-sized titanium dioxide powder being suspended in the silica-based binder solution, and the dispersed nano-sized titanium dioxide powder having an average primary particle size of not more than 70 nm, wherein the steel product is galvanized and the coating is formed on the surface of the galvanized steel product.