Abstract: A metal sheet, inclusive of a metal strip, having a front side and a back side, both the front side and the back side comprising a first coating having an average thickness in the range from 0.5 to 10 ?m, wherein the first coating of the front side contains particles, which release divalent or multivalent metal ions upon the action of an acid, in such an amount that a self-depositing coating agent forms, upon contact with the front side, a second coating thereon, whereas this is not the case for the first coating of the back side. The first coating of the front side can be overcoated with a self-depositing coating agent. Cut edges that do not have a first coating can be covered with the self-depositing coating agent. Correspondingly coated metal sheets, as well as a method for the manufacture thereof, are furthermore within the scope of the invention.

Abstract: Chromium-free conversion coating treatment solutions and processes for depositing a colored layer on zinc or galvanized steel, aluminum, magnesium or their alloys, are provided comprising: hexafluorotitanate and/or hexafluorozirconate ions; molybdate and/or tungstate ions; one or more chelating complex formers; and a copolymer of alkylene phosphonic or alkylene phosphinic acid and one or more unsaturated carboxylic acids.

Abstract: A method for producing colored layers on zinc, aluminum, magnesium or alloy surfaces. The surfaces are brought into contact with an aqueous treatment solution which is devoid of chrome, said solution containing, in total, 3-35 g/l persulfate ions and/or peroxodisulfate ions and not more than 10 g/l ammonia or ammonium ions, it has a pH value in the region of between 10-12 and a temperature in the range of between 30-80° C. The surfaces are brought into contact with the treatment solution for a period in the region of 0.5-5 minutes and optionally, they are covered with a coating based on organic polymers. The invention further relates to metal parts treated according to said method.

Abstract: A method for producing coloured layers on zinc, aluminium, magnesium or alloy surfaces. The surfaces are brought into contact with an aqueous treatment solution which is devoid of chrome, said solution containing, in total, 3-35 g/l persulfate ions and/or peroxodisulfate ions and not more than 10 g/l ammonia or ammonium ions, it has a pH value in the region of between 10-12 and a temperature in the range of between 30-80° C. The surfaces are brought into contact with the treatment solution for a period in the region of 0.5-5 minutes and optionally, they are covered with a coating based on organic polymers. The invention further relates to metal parts treated according to said method.

Abstract: A method for producing coloured layers on zinc, aluminium, magnesium or alloy surfaces. The surfaces are brought into contact with an aqueous treatment solution which is devoid of chrome, said solution containing, in total, 3-35 g/l persulfate ions and/or peroxodisulfate ions and not more than 10 g/l ammonia or ammonium ions, it has a pH value in the region of between 10-12 and a temperature in the range of between 30-80 ° C. The surfaces are brought into contact with the treatment solution for a period in the region of 0.5-5 minutes and optionally, they are covered with a coating based on organic polymers. The invention further relates to metal parts treated according to said method.

Abstract: A chromium-free treatment solution for producing colored or fluorescing corrosion prevention layers on metal surfaces which contains phosphoric acid and/or at least one fluoro acid of one or more elements from the group consisting of B, Si, Ti, Zr and Hf or anions thereof and at least one organic polymer, the organic polymer being capable of binding to the metal surface through oxygen and/or nitrogen atoms, and having covalently bonded groups which appear colored to the human eye or which fluoresce discernibly to the human eye on exposure to UV light.

Abstract: A method for producing coloured layers on zinc, aluminium, magnesium or alloy surfaces. The surfaces are brought into contact with an aqueous treatment solution which is devoid of chrome, said solution containing, in total, 3-35 g/l persulfate ions and/or peroxodisulfate ions and not more than 10 g/l ammonia or ammonium ions, it has a pH value in the region of between 10-12 and a temperature in the range of between 30-80 ° C. The surfaces are brought into contact with the treatment solution for a period in the region of 0.5-5 minutes and optionally, they are covered with a coating based on organic polymers. The invention further relates to metal parts treated according to said method.

Abstract: Chromium-free conversion coating treatment solutions and processes for depositing a colored layer on zinc or galvanized steel, aluminum, magnesium or their alloys, are provided comprising: hexafluorotitanate and/or hexafluorozirconate ions; molybdate and/or tungstate ions; one or more chelating complex formers; and a copolymer of alkylene phosphonic or alkylene phosphinic acid and one or more unsaturated carboxylic acids.