Patent ID: 7749337

Claim:
A process for the passivation of a metallic surface which comprises treating the metallic surface with an acidic, aqueous formulation comprising at least one water-soluble polymer X comprising acidic groups and at least one metal ion, wherein the polymer has at least 0.6 mol of acid groups/100 g of the polymer, the pH of the formulation is from 0.5 to 3.5, the amount of the polymer is from 5 to 40% by weight, based on the amount of all components of the formulation, the metal ion is at least one selected from the group consisting of Zn2+, Ca2+, Mg2+ and A13+, and the amount of metal ions is from 0.01% by weight to 25% by weight, based on the total amount of all polymers X, wherein the passivation is a chromium and fluoride free passivation and there are no ions of nickel, of manganese and of cobalt are used in the process.