COMPOSITION AND PROCESS FOR PREPARING PROTECTIVE COATINGS ON METAL SUBSTRATES

摘要

This invention comprises an acidic aqueous solution for treating metal substrates to improve the adhesion bonding and corrosion protection of the metal surface which comprises effective amounts of water soluble trivalent chromium compounds, fluorozirconates, effective amounts of at least one corrosion inhibitors such as benzotriazole, fluorometallic compounds, zinc compounds, thickeners, surfactants, and at least about 0.001 mole per liter of the acidic solution of a polyhydroxy and/or carboxylic compound as a stabilizing agent for the aqueous solution.