Composition of matter particularly adaptable for use in electrodepositing films on metal

Claim 1

A composition of matter comprising an aqueous dispersion of a mixture from about 4% to 50%, by weight, of (A) an ungelled modified cross-linking agent, having a pKa value of 3.6 or lower, comprising an aminoplast cross-linking agent modified by reaction with a non-resinous hydroxyl-group containing carboxylic acid, wherein the mol ratio of said unmodified cross-linking agent to said non-resinous hydroxyl-group containing carboxylic acid is between 1:0.1 and 1:1 respectively, from about 40% to about 90%, by weight, of (B) a water dispersible non-gelled polymeric material carrying a cationic charge and having a pKb value above 5.5, which polymeric material contains at least one class of reactive groups, selected from the group consisting of carboxyl groups, alcoholic hydroxy groups and amide groups and said polymeric material also contains amino groups wherein the total amount of said groups is at least about 0.5%, by weight, and not more than about 15%, by weight, based on the total weight of the polymeric material, wherein the total amount of said amino groups is at least about 0.25% and not greater than about 5%, by weight, based on the total weight of said polymeric material wherein said carboxyl groups, alcoholic hydroxy groups and amide groups are heat reactive with (A), and from about 1% to about 10%, by weight, of (C) an acid solubilizer, wherein the said percentages of (A), (B) and (C), by weight, total 100% and are based on the total solids weight of (A), (B) and (C).