Abstract: Aqueous compositions useful as pretreatments prior to painting to reduce the formation of rust in the uncoated condition. The compositions consist essentially of water, a trivalent chromium compound with the formula Cr(HxPO4)3, where x can be 1.5 or 2, a silica compound, and optionally hydrogen peroxide. The composition may have a pH between about 1 and about 4. A process for treating a metal surface includes contacting the surface with such aqueous compositions. The compositions and the processes provide benefits in comparison to the zinc phosphate metal pretreatment thought to be the standard in the industry.

Abstract: Aqueous compositions useful as pretreatments prior to painting and to reduce the formation of rust in the uncoated condition consist essentially of water, an organo-functional silane, a compound of a Group IV-B element, and optionally a polyvinyl alcohol, stabilizing agents, wetting agents, thickeners, and biocides, and have an alkaline pH>7. A process for treating a metal surface includes contacting the surface with such an aqueous composition. The compositions and processes were found to have further benefits in comparison to the zinc phosphate metal pretreatment thought to be the standard in the industry. Preferably, the pH of the compositions is alkaline, which has been found to improve the efficacy of a silane as a surface treatment to improve uniformity of paint adhesion. By operating in the alkaline pH range, it was found that flash rusting and/or blush rust were significantly reduced.

Abstract: Aqueous compositions useful as pretreatments prior to painting and to reduce the formation of rust in the uncoated condition consist essentially of water, an organo-functional silane, a compound of a Group IV-B element, and optionally a polyvinyl alcohol, stabilizing agents, wetting agents, thickeners, and biocides, and have an alkaline pH>7. A process for treating a metal surface includes contacting the surface with such an aqueous composition. The compositions and processes were found to have further benefits in comparison to the zinc phosphate metal pretreatment thought to be the standard in the industry. Preferably, the pH of the compositions is alkaline, which has been found to improve the efficacy of a silane as a surface treatment to improve uniformity of paint adhesion. By operating in the alkaline pH range, it was found that flash rusting and/or blush rust were significantly reduced.

Abstract: Aqueous compositions useful as pretreatments prior to painting and to reduce the formation of rust in the uncoated condition consist essentially of water, an organo-functional silane, a compound of a Group IV-B element, and optionally a polyvinyl alcohol, stabilizing agents, wetting agents, thickeners, and biocides, and have an alkaline pH>7. A process for treating a metal surface includes contacting the surface with such an aqueous composition. The compositions and processes were found to have further benefits in comparison to the zinc phosphate metal pretreatment thought to be the standard in the industry. Preferably, the pH of the compositions is alkaline, which has been found to improve the efficacy of a silane as a surface treatment to improve uniformity of paint adhesion. By operating in the alkaline pH range, it was found that flash rusting and/or blush rust were significantly reduced.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: A composition for forming a protective coating on a metal surface includes water; Cr2(GF6)3 in which G is a Group IV-B element; and at least one polymer having a plurality of carboxylic acid groups and at least one polymer having a plurality of hydroxyl groups, and/or at least one polymer having a plurality of both carboxylic acid and hydroxyl groups; wherein the composition contains less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions relative to chromium. A method of forming a protective coating on a metal surface includes contacting the metal surface with the composition.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: Aqueous compositions useful as pretreatments prior to painting and to reduce the formation of rust in the uncoated condition consist essentially of water, an organo-functional silane, a compound of a Group IV-B element, and optionally a polyvinyl alcohol, stabilizing agents, wetting agents, thickeners, and biocides, and have an alkaline pH>7. A process for treating a metal surface includes contacting the surface with such an aqueous composition. The compositions and processes were found to have further benefits in comparison to the zinc phosphate metal pretreatment thought to be the standard in the industry. Preferably, the pH of the compositions is alkaline, which has been found to improve the efficacy of a silane as a surface treatment to improve uniformity of paint adhesion. By operating in the alkaline pH range, it was found that flash rusting and/or blush rust were significantly reduced.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: A composition for forming a protective coating on a metal surface includes water; Cr2(GF6)3 in which G is a Group IV-B element; and at least one polymer having a plurality of carboxylic acid groups and at least one polymer having a plurality of hydroxyl groups, and/or at least one polymer having a plurality of both carboxylic acid and hydroxyl groups; wherein the composition contains less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions relative to chromium. A method of forming a protective coating on a metal surface includes contacting the metal surface with the composition.

Abstract: A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

Abstract: An aqueous solution and method for applying the solution to a metal surface form a zinc phosphate coating on the metal surface. The zinc phosphate coating minimizes corrosion and improves adhesion of subsequently coated materials such as sealants and paints. The solution of the composition and method of application consume free acidity otherwise left on the metal surface, and obviate the need for subsequent rinsing or extensive drying or stoving operations. The composition includes an aqueous solution including water, a zinc source, phosphoric acid, a polyhydric compound (preferably pentaerythritol), a metal salt, and optionally, an oxidizer.

Abstract: An aqueous solution and method for applying the solution to a metal surface form a zinc phosphate coating on the metal surface. The zinc phosphate coating minimizes corrosion and improves adhesion of subsequently coated materials such as sealants and paints. The solution of the composition and method of application consume free acidity otherwise left on the metal surface, and obviate the need for subsequent rinsing or extensive drying or stoving operations. The composition includes an aqueous solution including water, a zinc source, phosphoric acid, a polyhydric compound (preferably pentaerythritol), a metal salt, and optionally, an oxidizer.

Abstract: A method for treating magnesium die castings sufficiently cleans the die castings and improves their paint adhesion and corrosion resistance by utilizing hydroxy acetic acid, among other constituents. The method includes cleaning the castings with an alkaline cleaning solution, rinsing with water, pickling the castings with an aqueous hydroxy acetic acid solution, rinsing with water again, and then contacting the castings with a chrome-free pretreatment. The alkaline cleaning and pickling steps appear to remove substantially all die casting impurities in order to adequately prepare the metal for application of the pretreatment. The chrome-free pretreatment may be an organofunctional silane solution or an aqueous polymeric system having hydroxyl and carboxylic functional groups along with a compound of a group IV-B element. The pretreatment is then painted or contacted with another decorative coating, with no rinsing step occurring between the pretreatment and painting steps.

Abstract: An aqueous solution and method for applying the solution to a metal surface form a zinc phosphate coating on the metal surface. The zinc phosphate coating minimizes corrosion and improves adhesion of subsequently coated materials such as sealants and paints. The solution of the composition and method of application consume free acidity otherwise left on the metal surface, and obviate the need for subsequent rinsing or extensive drying or stoving operations. The composition includes an aqueous solution including water, zinc dihydrogen phosphate, phosphoric acid, a polyhydric polymer, a metal salt, and optionally, a fluoride.

Abstract: A method and composition for treating metal surfaces to improve corrosion resistance and paint adhesion. The composition is a non-corrosive aqueous solution including water, a polymeric compound, an additive, and dispersed silica. In a preferred embodiment, the polymeric compound may be a polymer having a plurality of carboxylic functional groups and a plurality of hydroxyl groups. The polymeric compound may be a bifunctional copolymer or the reaction product of a first polymer having a plurality of carboxylic functional groups (e.g., polyacrylic acid or polymethylvinylmaleic anhydride), and a second polymer having a plurality of hydroxyl groups (e.g., polyvinyl alcohol). The additive is selected from at least one of: (i) an acid of a group IV-B element and a weak base, and (ii) an ammonium salt of a group IV-B compound such as ammonium zirconium carbonate. An exemplary acid of a group IV-B element is fluotitanic acid and an exemplary weak base is ammonium hydroxide.

Abstract: A method and composition for coating a metal for use in connection with improving corrosion resistance and paint adhesion. The composition is a non-corrosive ester cross-linked polymer system having a plurality of carboxylic functional groups and a plurality of hydroxyl groups. The polymer system may be a bifunctional copolymer or the reaction product of a first polymer having a plurality of carboxylic functional groups (e.g. polyacrylic acid or polymethylvinylmaleic anhydride), and a second polymer having a plurality of hydroxyl groups (e.g. polyvinyl alcohol). The resulting reaction product of these two polymers is a cross-linked polymeric blend. A compound of a Group IV-B element may be added to this polymer blend to increase the degree of cross-linking and improve paint adhesion and corrosion resistance. Such a Group IV-B compound may be an acid such as fluozirconic acid, fluotitanic acid or fluchafnic acid, or a salt such as ammonium zirconium carbonate.

Abstract: A method and composition for coating a metal for use in connection with improving corrosion resistance and paint adhesion. The composition is a non-corrosive ester cross-linked polymer system having a plurality of carboxylic functional groups and a plurality of hydroxyl groups. The polymer system may be a bifunctional copolymer or the reaction product of a first polymer having a plurality of carboxylic functional groups (e.g. polyacrylic acid or polymethylvinylmaleic anhydride), and a second polymer having a plurality of hydroxyl groups (e.g. polyvinyl alcohol). The resulting reaction product of these two polymers is a cross-linked polymeric blend. A compound of a Group IV-B element may be added to this polymer blend to increase the degree of cross-linking and improve paint adhesion and corrosion resistance. Such a Group IV-B compound may be an acid such as fluozirconic acid, fluotitanic acid or fluohafnic acid, or a salt such as ammonium zirconium carbonate.