Abstract: Aqueous compositions useful as pretreatments prior to painting and to prevent the formation of white rust in the uncoated condition include an organopolyphosphonic acid or salt thereof, an organosilane, and a trivalent chromium compound. A method for treating a surface of a zinc-containing metal includes contacting the surface with an aqueous composition including an organopolyphosphonic acid or salt thereof, an organosilane, and a trivalent chromium compound. The composition may also include an agent for reducing hydrophilicity, such as a polyacrylic acid. The aqueous composition has been found to be particularly well-suited for treating a zinc-containing metal to passivate the surface, improve paint adhesion, and/or improve corrosion resistance.

Abstract: Compositions for preparing coatings on metal substrates include a phosphonic acid, polyvinyl alcohol, an optional catalyst, and optionally an organo-functional silane. The catalyst may be a group IV-B compound, a boron compound, a vanadium compound, or a molybdenum compound. The compositions may be applied from an aqueous carrier to a metal surface and then dried to form a coating imparting good paint adhesion and corrosion resistance to the metal substrate.

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 removing metallic copper from a steel surface defining a bore or cylinder of a gun is provided. The method involves contacting the surface with a composition comprising a polyphosphonic acid, a hydroxyl-substituted primary amine, and water.

Abstract: A composition for removing copper from a surface comprises a polyphosphonic acid, a primary amine, and water. Optionally, the composition may also comprise a dialkanolamine and/or a trialkanolamine, a degreaser, and/or a surfactant. The pH of the composition is between 9.0 and 12.5. The method of removing copper from a surface, which may be a gun bore, involves contacting the surface with the composition.

Abstract: An acidic, aqueous composition contains a trivalent chromium compound, an organo-functional silane, and a compound of a group IV-B element. The composition protects metal surfaces, preferably aluminum and aluminum alloys, against corrosion and improves their paint adhesion. The trivalent chromium compound may comprise chromium fluoride and optionally others, such as chromium nitrate. The organo-functional silane is preferably an aminopropyltriethoxy silane, and the compound of a group IV-B element is preferably fluorozirconic acid. The composition can either be dried-in-place or rinsed before a further coating layer is applied. The composition may also include at least one polymer having a plurality of both carboxylic functional groups, alone or with hydroxyl groups.

Abstract: A composition for treating the surface of a ferrous metal. The composition comprises aluminum sulfate, boric acid or a boric acid precursor, and polycarboxylic acid or salt thereof. Treatment of the ferrous metal with an aqueous solution of the composition at elevated temperature and low pH provides a coating that imparts lubricity to the metal, thereby facilitating metalworking processes such as drawing for wire production.

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 and composition for treating a metal surface, particularly steel, involves contacting the metal surface with a pretreating solution comprising a blend of water, an organo-functional silane, and a borate ester. The method involves first cleaning the metal surface, such as by using an alkaline cleaning agent, then rinsing prior to the application of the pretreating solution. The metal surface is dried and, either immediately thereafter or after some storage time, then contacted with a decorative finish, such as paint, completing the metal treatment method. The method and composition minimize rusting of the metal surface even if a relatively long period of time elapses between drying the pretreated metal surface and painting the metal surface. In addition, the method and composition provide good adhesion of the decorative finish to the metal surface.

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 forming a zinc phosphate coating on a metal surface utilizes an aqueous solution of zinc, phosphate, nitrate, nickel, a compound containing a group IV-B element, and a fluosurfactant. The method involves contacting the metal surface with such a bath under process conditions such that a coating is formed on the metal surface. Preferably, the compound containing a group IV-B element is a fluoacid of titanium, zirconium, or hafnium. More preferably, the fluoacid is fluotitanic acid. The fluosurfactant may be any compatible fluosurfactant but preferably is an amine perfluoroalkyl sulfonate or a non-ionic, fluorinated alkyl polyoxethylene ethanol or a combination of both. The coating serves to improve the ability of the metal to retain a lubricant on its surface (for cold working of the metal), to improve corrosion resistance, and to improve paint adhesion.

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.

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.

Abstract: A method for treating a metal surface involves contacting the metal surface with an aqueous silicate solution, contacting the silicate-coated metal surface with an aqueous organo-functional silane solution, and then contacting the silane-coated metal surface with a chrome-free pretreatment. Preferably, the bath containing the aqueous silicate solution also includes a cleaning agent for cleaning the metal surface. Alternatively, the metal surface may be cleaned in a separate step before the metal surface is contacted with the aqueous silicate solution and, optionally, the metal surface is rinsed with water after the metal surface is cleaned and before the metal surface is contacted with the aqueous silicate solution. The silicate-coated metal surface may be rinsed with water before it is contacted with an aqueous organo-functional silane solution. In addition, the silane-coated metal surface may be rinsed with water before it is contacted with a chrome-free pretreatment.

Abstract: A method and composition for indicating the presence of a chrome-free pretreatment for improving the paint adhesion and corrosion resistance of a metal surface. The presence of the pretreatment is indicated by adding a compound to the chrome-free pretreatment which causes the pretreatment to fluoresce under an ultraviolet light. The additive which causes the pretreatment to fluoresce under an ultraviolet light is an ultraviolet tracer, such as a stilbene or a coumarin derivative, and the method according to this invention includes exposing the coated metal to ultraviolet light.