Patent ID: 8273189
Filing Date: 2012-09-25
Classification: C23C

Abstract:
1. A method of conversion by carboxylation of a metal surface selected from the group consisting of zinc, iron, aluminium, copper, lead and their alloys, and galvanized, electrozinced, aluminized, and copper-plated steels, under oxidizing conditions in relation to the metal surface, by bringing said metal surface into contact with a aqueous or hydro-organic bath containing a mixture of organic acids, said mixture being such that: said organic acids are saturated linear carboxylic acids having from 10 to 18 carbon atoms, said mixture is a binary or ternary mixture of said organic acids, said mixture is present in said bath in a concentration of 20 g/l or more, said organic acids are present in said mixture in respective ratios such that: