POST-TREATMENT SOLUTION FOR SELF-DEPOSITED COATING FILM FORMED ON METAL SURFACE, AND PROCESS FOR PRODUCTION OF METALLIC MATERIAL HAVING POST-TREATED SELF-DEPOSITED COATING FILM FORMED THEREON

摘要

Disclosed is a post-treatment technique for a self-deposited coating film that contains tannin as a resin component, which does not contain any environmentally hazardous component such as chromium and can impart high levels of corrosion resistance and adhesion properties to the self-deposited coating film. Specifically disclosed is a post-treatment solution for a self-deposited coating film that is formed on a metal surface and contains tannin as a resin component. The post-treatment solution is characterized by being an aqueous solution comprising at least one metal component selected from the group consisting of lithium, manganese, iron, cobalt, nickel, copper and aluminum and phosphoric acid.