METAL PRODUCT APPLIED WITH RUSTPREVENTIVE COATING

摘要

PROBLEM TO BE SOLVED: To ensure rustpreventive performance even for metal products having a relatively thin rustpreventive film and prevent occurrence of white and black rust, together with red rust, over a long period. SOLUTION: A coating film is formed on a metal product with a non-chromium aqueous metal rustpreventive coating prepared by mixing a binder aqueous solution containing an aqueous resin emulsion and a water-soluble silane coupling agent with powder of scale-like metal zinc, and a non-chromium surface-treating agent based on an alkoxysilane oligomer of a specified weight average molecular weight is applied onto the coating film. The application of the surface-treating agent prolongs twice the time for occurrence of red rust on the product and also prevents occurrence of white and black rust over a long period. Blending of superfine powder of titanium oxide with the surface-treating agent improves the rustpreventive effect further. The surface-treating agent exerts similar effects when applied onto a metal product coated with a commercial zinc-rich paint. COPYRIGHT: (C)2005,JPO&NCIPI