| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface-treated weatherproof steel material which has a coating film with sufficient durability equivalent to that treated by using hexavalent chromium, even if using no hexavalent chromium and the like having high environmental load, and which is economical and superior in weather resistance. SOLUTION: The surface-treated weatherproof steel material is covered with at least a coating film formed on the steel material surface of the weatherproof steel, wherein the coating film includes a polyvinylbutylal resin forming a complex with vanadic acid and phosphoric acid, a resin compatible with the polyvinylbutylal resin, Fe<SB>2</SB>O<SB>3</SB>and Fe<SB>3</SB>O<SB>4</SB>. COPYRIGHT: (C)2009,JPO&INPIT |
