Non-chromate aqueous metal surface treating composition, surface-treated steel, painted steel, steel surface treatment method, and painted steel preparing method

摘要

A non-chromate aqueous metal surface treating composition is provided comprising water and an organosilicon compound obtained through hydrolysis of a mixture of a hydrolyzable silane bearing a nitrogen-containing organic group or a partial hydrolyzate thereof and another hydrolyzable silane or a partial hydrolyzate thereof. The surface treating composition is applied to steel members, giving surface treated steel members having high corrosion resistance and workability. When an overcoat layer is formed thereon, painted steel members of quality are manufactured.