Anticorrosive metal surface pretreating composition

Abstract

An anticorrosive metal surface pretreating composition comprising: (a) an emulsion of polymer particles comprising at least one .alpha., .beta.-ethylenically unsaturated monomers, bearing thereon, as protective colloid, an oligomer with hydrophylic groups comprising at least one .alpha.,.beta.-ethylenically unsaturated monomer, the mean diameter of the particles being 0.1 to 3.mu. and the particles being formed as hard microparticles through internal gelation or having a glass transition point from 15.degree. to 110.degree. C., and (b) a water soluble chromium compound, 25 to 50% by weight of the total chromium contained being of trivalent, the weight ratio of said emulsion solid to metallic chromium being 1:10.about.5:1. The present composition affords a pretreatment coating with improved anticorrosive, bending and scratch resistant properties on various metallic substrates.

Dependencies are inferred from the claim text.