Patent ID: 6537387
Filing Date: 2003-03-25
Classification: C23C

Abstract:
A process for protecting a steel strip coated with zinc or a zinc alloy comprising(a) contacting the steel strip with an aqueous treatment solution having a pH of from 1.5 to 3.5 and comprising (i) 1 to 20 g/L manganese (II) ions; (ii) 1 to 150 g/L phosphate ions; and (iii) one or more organic polymers selected from the group consisting of polymers and copolymers of polymerizable carboxylic acids, at least one of said polymerizable carboxylic acids being selected from the group consisting of acrylic acid, methacrylic acid, maleic acid and esters thereof with alcohols having 1 to 6 C atoms; and (b) drying the aqueous treatment solution without intermediate rinsing.