Non-chromate conversion coatings
AssigneeDart Industries Inc.
InventorsJohn L. H. Allan, Philip D. Readio, Ajay M. Bengali, Richard F. Zuendt
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Abstract
Improved color, brightness and corrosion resistance are imparted to metal surfaces such as zinc plated surfaces, by treatment with a non-toxic solution comprised of sulfuric acid, hydrogen peroxide, a silicate and at least one cationic triarylmethane dye. Certain organophosphorus compound additives further enhance the corrosion resistance.
Claims21
A conversion coating solution which comprises an aqueous solution of from about 0.2 g/l to about 45 g/l of free H.sub.2 SO.sub.4, from about 1.5 g/l to about 58 g/l of H.sub.2 O.sub.2, from about 3 g/l to about 33 g/l of SiO.sub.2 and an effective amount of at least one cationic triarylmethane dye.
Dependencies are inferred from the claim text.