| 摘要 |
PURPOSE:To improve the corrosion resistance of a film of the resulting metallic surface treating agent and the adhesive strength to paint by blending an emulsion of a polymer of an alpha,beta-monoethylenic unsatd. monomer contg. a specified water-soluble polymer as an emulsifier with a water-soluble chromium compound. CONSTITUTION:Polyacrylic acid or a copolymer of acrylic acid with one or more kinds of monomers selected among methacrylic acid, acrylamides, methacrylamides and hydrophilic monomers represented by the formula (where A is H or CH3, R is 2-4C optionally substituted alkylene, and X is one or more among O, P and S) is used as an emulsifier. An alpha,beta-monoethylenic unsatd. monomer is emulsion-polymerized by using said emulsifier by 5-100pts.wt. per 100pts.wt. monomer to prepare an emulsion contg. rigid polymer particles having 0.1-3mum particle size and 15-110 deg.C glass transition point. This emulsion is blended with a water soluble Cr compound contg. tervalent Cr by 25-50wt% of the total amount of Cr to obtain a metallic surface treating agent. At this time, the weight ratio between the solid matter in the emulsion and Cr is adjusted to 1:<=9-<2:1.
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