AQUEOUS SURFACE-TREATING AGENT FOR ENVIRONMENTAL RESPONSE TYPE PRE-COATED METAL MATERIAL AND SURFACE-TREATING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a non-chromium based aqueous surface-treating agent useful as a substrate-treating agent for forming pre-coated metal materials having excellent coating adhesiveness, corrosion resistance and coin scratch resistance. SOLUTION: This aqueous surface-treating agent for environmental response type pre-coated metal materials contains a silane coupling agent (A) and a vanadium-containing compound and/or tungsten-containing compound (B) in a vanadium atom and/or tungsten atom/(A) solid content mass ratio of 0.1/100 to 40/100. The coating adhesiveness and the coin scratch resistance are further improved by further compounding the surface-treating agent with water-dispersible silica (C). When an amino functional group-containing silane coupling agent is used, coating adhesiveness is excellent. When an amino group (primary or secondary)-containing silane coupling agent and a silane coupling agent having an epoxy group bound to adjacent carbon atoms are together used, the corrosion resistance is further improved. A method for treating the surface of an environmental response type pre-coated metal material is characterized by coating the surface of the metal material with the aqueous surface-treating agent and then drying the coated aqueous surface-treating agent to form the dried coating film of 0.01 to 1 g/m2. A method for producing a non-chromium-based pre-coated metal material is characterized by applying a chromium-free top coating to the metal material surface-treated by the surface-treating method. COPYRIGHT: (C)2007,JPO&INPIT