RESIN CHROMATE COMPOSITION, AND ITS APPLICATION, AND RESIN CHROMATE-TREATED METALLIC SHEET EXCELLENT IN FILM FORMABILITY AND WORKED CORROSION RESISTANCE

摘要

PROBLEM TO BE SOLVED: To obtain a resin chromate composition excellent in bath stability and odor characteristic by specifying the lowest temp. at which an org. thin film is formed from the mixture of an org. polymer emulsion consisting of an ethylenic unsaturated compd. among the main components and a water-soluble additive. ;SOLUTION: A resin chromate composition consisting essentially of an org. polymer emulsion (a) formed by dispersing an org. polymer composed of an ethylenic unsaturated compd. (acrylic acid, methacrylic acid, etc.), a water-soluble chromium compd. (b) (chromic anhydride, etc.), a mineral acid (c) (phosphoric acid, etc.) and a water-soluble or water-dispersible additive (d) (caprylic acid, oxalic acid, malic acid, etc.) is prepared. The lowest temp. at which an org. thin film is formed from a mixture of the components (a) and (d) is controlled to ≤20°C and made ≥2°C lower than the lowest temp. at which an org. thin film is formed from the component (a) alone. A metallic sheet is treated with this composition to obtain a resin chromate-treated metallic sheet having excellent film formability and worked corrosion resistance.;COPYRIGHT: (C)1998,JPO