Abstract: The invention relates to a functionalized phenol-aldehyde resin which comprises a phenol-aldehyde condensation product, having a phenol component with no carboxyl group, and an aromatic hydroxycarboxylic acid and imidazole as constituents which is useful for corrosion-inhibiting treatment of bare or conversion-coated metal surfaces is provided. Methods of making the functionalized phenol-aldehyde resin, processes for coating metal surfaces using compositions according to the invention and products coated thereby are also included in the invention.

Abstract: The invention relates to a chromium-free, corrosion prevention treatment for steel, zinc or zinc alloys, aluminum, magnesium or alloys thereof in which the metal surfaces are contacted in a first step with a first aqueous solution having a pH of 1.5 to 5 which contains Ti and/or Zr and/or Si ions and at least such a quantity of fluoride that the atomic ratio of Ti to F and/or Zr to F and/or Si to F is in the range from 1:1 to 1:6 and then, optionally after rinsing with water, and thereafter in a second step are contacted with a second aqueous solution having a pH of 1.5 to 5 which contains Ti and/or Zr and/or Si ions and at least such a quantity of fluoride that the atomic ratio of Ti to F and/or Zr to F and/or Si to F is in the range from 1:1 to 1:6, and which additionally contains such a quantity of soluble anions of oxo acids of Mo (VI) and/or W (VI) that the total concentration of molybdenum and/or tungsten is in the range from 5 to 1500 mg/l.

Abstract: The invention relates to a corrosion protection method for application in connection with the production of finished metallic components from organically precoated metal sheets. In the course of such production, areas of uncoated metal which inevitably come about in the course of cutting, forming and joining the precoated metal sheets are provided with a chromium-free corrosion protection coat that is not a zinc phosphate coating, which serves at the same time as a tie coat for the subsequent finish. The treatment solution preferably contains fluoro complexes of Ti, Zr and/or Si and also organic polymers. The invention also embraces a metallic component treated accordingly.

Abstract: An agent and process for the corrosion protection treatment of a metal surface are provided.

Abstract: An aqueous solution for producing a conversion layer on metal surfaces, which has a pH in the range 1.5 to 6 and which contains the complex fluorides of Ti, Zr, Hf, Si and/or B, in an amount such that the concentration of Ti, Zr, Hf, Si and/or B is 20 to 500 mg/l, and 0.1 to 2 g/l of adhesion-promoting lacquer additives and wherein the composition of the aqueous solution is selected so that no crystalline zinc-containing phosphate layer is produced on the metallic surface.

Abstract: A process for the anti-corrosive treatment of vehicle bodies or domestic appliances which have, at least in part, a metal surface and wherein this metal surface consists of at least 90%, based on the metal surface, zinc, aluminum and/or magnesium and/or alloys of these metals with one another or with other alloying elements, wherein the vehicle bodies or domestic appliances are cleaned, passivated and painted, characterised in that, for the purpose of passivation, the vehicle bodies or domestic appliances are contacted with an aqueous solution having a pH of 1 to 12 and containing complex fluorides of Ti, Zr, Hf, Si and/or B in a quantity such that the content of Ti, Zr, Hf, Si and/or B is 20 to 500 mg/l, and 50 to 2000 mg/l organic polymers, the composition of the aqueous solution being selected such that no crystalline zinc-containing phosphate layer is formed on the metal surface.