| 摘要 |
The present invention relates to a method for preventing rust in the surface of metal and, specifically, to a method for forming a rust preventing treatment film for applying corrosion resistance, chemical resistance, or colored appearance to various materials of metal including iron, for example, a brake disk, a bolt, a nut, a spring, a shaft, a piston, a cylinder, bearing metal, etc. According to the present invention, the method for preventing rust comprises: a first step for forming a primer layer by coating a metal material including iron with a baking type zinc containing treatment liquid containing organo functional silanes; a second step for forming an upper coating layer by an aqueous chrome non-containing treatment liquid containing (A) aqueous modified epoxy resin, (B) rustproof pigment, (C) body pigment, and (D) organo functional silanes before a lower coating layer is completely dried; and a third step for hardening the lower coating layer and the upper coating layer at 250-350°C. According to the present invention, a metal surface treatment film is capable of mixing a specific aqueous chrome non-containing treatment liquid with a baking type zinc containing treatment liquid containing an organo functional silane bonding material in a two-coat and one-bake method with excellent production efficiency. Therefore, the metal surface treatment film has the excellent corrosion resistance and chemical resistance with a single baking at 250-350°C, and is stable as a treatment liquid, so the metal surface treatment film can be used for the wide range of various metal components. Moreover, the present invention has an effect for obtaining a composite film having good adhesive properties and corrosion resistance by the reaction of a functional group, and the condensation reaction of a hydrolyzed silanol group of modified epoxy resin and organo functional silane contained in the aqueous chrome non-containing treatment liquid as upper coating, and an organo functional silane bonding material contained in a lower coating treatment liquid. |
