Patent ID: 8764916

Claim:
An agent for the production of anti-corrosion layers on metal surfaces, produced by the following steps: A) producing an aqueous solution which contains at least the following: a) oxo-cations selected from MnO 3 + , VO 3+ , VO 2+ , WO 2 2+ , MoO 2 2+ , TiO 2+ , ZrO 2+ and mixtures thereof, in a concentration of between 0.1 and 0.5% by weight, and b) halogen complex anions of the structure MX a b− , wherein M is selected from B, Ti, Zr, Si, Al, X is selected from F, Cl, Br, I, a is an integer of between 3 and 6 and b is an integer of between 1 and 4, in a concentration of between 0.1 and 3.0% by weight, and B) forming nanoparticles the formation of which results in a positive Tyndall effect and having a mean particle diameter of <500 nm in the solution in situ by physical and/or chemical treatment of the solution, wherein the physical and/or chemical treatment is selected from the group consisting of supersaturation of the solution with halogen complex anions, agitation of the solution, and a combination thereof.