Patent ID: 6059897
Filing Date: 2000-05-09
Classification: C25D

Abstract:
A process for postsealing an anodized metal surface wherein the anodized metal surface is brought into contact with an aqueous sealing solution for a period of between 0.5 and 2 minutes per micrometer of anodized coating thickness, said aqueous sealing solution being at a temperature between 75.degree. C. and its boiling point during its contact with the anodized metal surface, having a pH value in a range from 5.5 to 6.5 and comprising water and:a) a total of 0.0004 to 0.05 g/l of one or more surfactants selected from the group consisting of:(a.1) alkyl and alkylaryl sulfates and sulfonates; and(a.2) alkoxylates of fatty alcohols and fatty amines having an alkyl moiety with at least 8 C atoms; andb) a total of 0.0005 to 0.5 g/l of one or more organic acids selected from the group consisting of(b.1) cyclic polycarboxylic acids having 3 to 6 carboxyl groups and(b.2) phosphonic acids.