Aqueous solution for sealing anodized metal surfaces includes additives selected from maleic acid or anhydride (co)polymers, phosphinocarboxylic acid copolymers and non-polymeric organic phosphonic acids

摘要

Aqueous solution for sealing anodized metal surfaces, having a pH of 5.5-8.5 and containing 0.4-50 mg/l of a cationic, anionic or nonionic surfactant and 0.5-500 mg/l of a copolymer of (meth)acrylic acid or a 1-3C alkyl (meth)acrylate and a hypophosphite salt, includes a total of 0.1-100 mg/l of additive(s) selected from maleic acid or anhydride (co)polymers, phosphinocarboxylic acid copolymers and non-polymeric organic phosphonic acids. Independent claims are also included for the following: (1) an aqueous concentrate giving a solution as above after dilution with water by a factor of 100-1000 and optional pH adjustment; (2) a method for sealing anodized metal surfaces, comprising contacting the surface with a solution as above at 90-100 deg C for 1-4 minutes per mu m of anodized film thickness.