Abstract: Disclosed is an acidic cleaning aqueous solution for aluminum and aluminum alloy and a process for cleaning the same, intended to execute acidic cleaning without using harmful fluoride and chloride ions.The oxidation-reduction potential of a cleaning bath is controlled to be at 0.5 to 0.8 V (vs. Ag-AgCl). The cleaning bath is obtained by diluting an acidic cleaning aqueous solution for aluminum and aluminum alloy to a predetermined volume. The acidic cleaning aqueous solution contains specified amounts of at least one of inorganic acids, Br.sup.- ions and oxidized metal ions, with the addition of a surfactant and oxidizing agent if necessary.It is thus possible to present a uniform etching effect irrespective of low temperature (below 60.degree. C.) without containing fluoride ions and chromic ions within the acidic cleaning aqueous solution. Br.sup.

Abstract: An anticorrosive metal surface pretreating composition comprising an aqueous emulsion of hard polymer microparticles and a water soluble chromium compound, the polymer microparticles being prepared by emulsion polymerization of .alpha.,.beta.-unsaturated monomers including polyfunctional monomer(s) or monomer(s) capable of resulting polymer with a specific Tg value in the presence of a particular type of polymer as an emulsifier and a chromium compound, including specified amounts of trivalent chromium.

Abstract: A functional polymer having a main chain of carbon-carbon bonds and at least one functional group appended to the main chain with intervention of a carbonyliminocarbonyl linkage, the functional group being any one chosen from the group consisting of a fluorinated group, an aminotriazine group, a photosensitive group and a bicyclo or spiro structure group and the content of the functional groups including the carbonyliminocarbonyl linkage in the molecule of the functional polymer being from 0.1 to 99.9% by weight.

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.