ZIRCONIUM COMPOSITIONS OF PRELIMINARY PROCESSING CONTAINING MOLYBDENE, APPROPRIATE METHODS OF PROCESSING METAL SUBSTRATES AND CORRESPONDING METAL BREAST

摘要

1. A method of coating a metal substrate, comprising: pre-treating the metal substrate with a pre-treatment composition comprising a metal of Group IIIB and / or Group IVB, free fluoride, and molybdenum; electrophoretic deposition of the coating composition on a metal substrate, wherein said coating composition contains yttrium. 2. The method of claim 1, wherein the pretreatment composition comprises a Group IVB.3 metal. The method of claim 1, wherein the Group IVB metal is present in the form of hexafluorozirconic acid, hexafluorotitanic acid, or salts thereof. The method of claim 1, wherein the Group IVB metal is zirconium. The method of claim 1, wherein the Group IVB metal is present in the form of zirconium oxides or hydroxides. The method of claim 1, wherein the Group IVB metal is present in the form of zirconyl nitrate, zirconyl sulfate or basic zirconium carbonate. A method according to claim 1, wherein the metal of Group IIIB and / or Group IVB is present in the form of an acid or salt. The method according to claim 1, wherein the metal of Group IIIB and / or Group IVB accounts for from 50 to 500 parts per million, based on the total weight of the ingredients of the pretreatment composition. The method according to claim 1, wherein the metal of Group IIIB and / or Group IVB accounts for from 75 to 250 parts per million, based on the total weight of the ingredients of the pretreatment composition. The method of claim 1, wherein the molar ratio of the metal of Group IIIB and / or Group IVB to molybdenum is from 100: 1 to 1: 10.11. The method according to claim 1, wherein the free fluoride accounts for from 5 to 250 parts per million of the pre-treatment composition. A method according to claim 1, wherein free fluoride accounts for from 25 to 100 ppm of the pretreatment composition. The method of claim 1, wherein the molybdenum