Patent ID: 6645316
Filing Date: 2003-11-11
Classification: C02F,C23C,Y02A

Abstract:
A process for post-passivation of a phosphated metal surface, comprising treating a phosphated metal surface that has been treated with a phosphating solution with an aqueous post-passivation solution that comprises from 50 to 500 mg/l of nickel ions and from 200 to 1500 mg/l of phosphate ions, wherein the phosphated metal surface is contacted with the aqueous post-passivation solution and then rinsed with water or an aqueous solution, and:(a) wherein at least a part of the used rinsing water or solution from the rinsing step after the post-passivation treatment is added to the post-passivation solution; or (b) wherein the phosphated metal surface is rinsed with water or an aqueous solution prior to the post-passivation treatment and is rinsed again with water or an aqueous solution after the post-passivation treatment, and at least part of the used rinsing water or solution from rinsing after post-passivation is added to the rinsing water or solution to be used for rinsing prior to post-passivation.