Abstract
An investigation was made on the pretreatments for metal finishing with an emulsion obtained by copolymerization of methyl and butyl methacrylates in the presence of an anionic surfactant in an aqueous medium using no ordinary radical initiators. By dipping steel plate, previously coated with phosphate by conversion treatment, into the emulsion, its corrosion resistance and the adhesion of paint film to the steel were improved. The adhesive strength of paint film depended on the kind of emulsions used, especially on the structure of the copolymers. The emulsion of tert-butyl methacrylate copolymer showed much better effects than that of sec- or n-butyl methacrylate copolymer. The difference amoug the three emulsions in metal finighing effect was discussed in terms of the interaction of alkoxyl groups of the copolymer with film-forming components of the coating material.
