| 摘要 |
PURPOSE:To obtain the titled steel sheet in a surface treated steel sheet having a resin film by making the resin contained in the resin film a water-dispersible copolymer uncontaining a hydroxyl group, regulating the acid value, blending a coupler and containing hexavalent chromium into the resin film. CONSTITUTION:The following copolymer resin which has 10-200 acid value per solid material and is blended with silane and/or titanate coupler is used as the resin contained in a resin film wherein the copolymer resin is obtained by emulsion-polymerizing (A) 1-95wt% one or more kinds of monomers shown by the formula (R1 is H and CH3, R2 is 1-8C alkyl), (B) 3-20wt% alpha,beta-unsaturated carboxylic acid monomer and (C) 0-50wt% monomer capable of copolymerization with these monomers (wherein, the total A, B, C is 100wt%). Then, hexavalent chromium and silica sol are contained into the above-mentioned resin film. Thereby, the resin is not oxidized in the treatment stage and the water resistance, adhesive properties and physical properties of the film and the adhesive properties with the coated film are increased. Further, the resin film may be formed on a chromate film. |
