METHOD FOR TREATING METALLIC SURFACE

摘要

PURPOSE:To form a coating film which is non-tacky and has excellent durability, by coating a metallic surface with an aq. resin dispersion obtd. by emulsion- polymerizing a specified polymerizable monomer mixture in the presence of silica. CONSTITUTION:An aq. resin dispersion obtd. by emulsion-polymerizing 100pts.wt. at least one compd. (A) selected from alkyl alpha,beta-monoethylenically unsaturated carboxylates [e.g. methyl (meth)acrylate] and alkenylbenzenes (e.g. styrene) and 0.1-10pts.wt. monomer (B) contg. polymerizable unsaturated bonds and alkoxysilane groups per molecule (e.g. divinyldimethoxysilane) in the presence of 1- 200pts.wt. colloidal silica (C) having a particle size of 4-100mu and in the presence of an anionic surfactant and/or a nonionic surfactant in an aq. medium, is used. Said aq. resin dispersion is applied to a metallic surface to form a coating film of 3-20mu in thickness.