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.