Patent ID: 8293029

Claim:
An aqueous treatment solution for the production of colored layers on surfaces of zinc, aluminum, magnesium or their alloys, which contains: a) a total of 4 to 4000 mg/l of hexafluorotitanate and/or hexafluorozirconate ions, b) a total of 10 to 4000 mg/l of molybdate and/or tungstate ions, calculated as dihydrate of the Na salt, c) a total of 1 to 2000 mg/l of one or more non-polymeric chelating complex formers, d) 0.04 to 40 mg/l of a copolymer of alkylene phosphonic or alkylene phosphinic acid and one or more unsaturated carboxylic acids; e) polyvinyl alcohol or water-soluble or water-dispersible partial esters thereof in a concentration of at least 1 mg/l and at most 1000 mg/l; and further comprising one or more polymers, that are not part of d), selected from: f) polymers or copolymers of amides of unsaturated mono or dicarboxylic acids, in a concentration of at least 1 mg/l and at most 300 mg/l; g) esters of the polymers of groups e) and f) in a concentration of at least 1 mg/l and at most 300 mg/l; h) 0.01 to 20 g/l of a polymer or copolymer of vinyl pyrrolidone; i) amine-substituted polymers of 4-hydroxystyrene in a concentration of at least 1 mg/l and at most 2000 mg/l; j) polymers of diglycidyl ethers of bisphenol A in a concentration of at least 1 mg/l and at most 2000 mg/l; said treatment solution having a pH value in the range of 1 to 4.