Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
  • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
  • C23C18/1229—Composition of the substrate
  • C23C18/1241—Metallic substrates
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
  • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
  • C23C18/125—Process of deposition of the inorganic material
  • C23C18/1254—Sol or sol-gel processing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft

Definitions

• the present invention relates to a sol-gel surface coating that imparts corrosion resistance. In other embodiments, the present invention relates to a sol-gel coating composition and process for making and using the sol-gel coating composition.
• sol-gel coatings have been used as conversion coatings for aluminum and other metal substrates such as ferrous and zinc substrates.
• One particular use of sol-gel coatings has been in the aerospace industry.
• sol-gel coatings have been applied to substrates particular to that industry, such as aluminum and titanium alloys, as an adhesion promoter between the underlying substrate and a paint primer, such as an epoxy primer.
• a paint primer such as an epoxy primer.
• sol-gel coatings can provide good corrosion resistance, particularly on aluminum substrates, when the coating is baked.
• Typical sol-gel bake systems are 100° Celsius to 250° Celsius.
• typical sol-gel coatings are not particularly suitable since it is not considered advantageous to expose aircraft substrates to temperatures necessary to achieve baking.
• the same sol-gel coatings that have good corrosion resistance at the high bake temperatures tend not to perform well when cured in ambient conditions, such as at room temperature, which is the preferred temperature for curing a composition used on the exterior of an aircraft.
• sol-gel coating that can have favorable corrosion resistance when cured at temperatures less than 100° Celsius and, preferably around room temperature. Moreover, it would also be desirable if such a coating had good corrosion resistance performance at elevated cured temperatures.
• sol-gel compositions containing acid, metal acetate, and organosilane provide sol-gel coatings that can have favorable corrosion resistance when cured at temperatures less than 100° Celsius, such as room temperature.
• the present invention comprises a sol-gel composition comprising acid, metal acetate, organosilane, water and optionally a surfactant.
• the sol-gel composition comprises 1.75 - 8.0 weight percent acid, 1.5 - 8.0 weight percent metal acetate, 10 - 50 weight percent organosilane, 35 - 90 weight percent water, and 0 - 1 weight percent surfactant.
• the sol-gel composition comprises 2 - 4.0 weight percent acid, 1.75 - 4.0 weight percent metal acetate, 10 - 25 weight percent organosilane, 65 - 88 weight percent water, and 0 - 0.25 weight percent surfactant. Unless stated to the contrary, these and other weight percents are based on actives.
• the present invention comprises a sol-gel composition
• a sol-gel composition comprising glacial acetic acid, metal acetate, glycidoxypropyl trimethoxy silane, water and optionally a surfactant.
• the metal acetate can be either zirconium acetate, magnesium acetate, or a combination thereof.
• the sol- gel composition comprises 1.75 - 8.0 weight percent glacial acetic acid, 1.5 - 8.0 weight percent metal acetate, 10 - 50 weight percent of an epoxy silane, such as glycidoxypropyl trimethoxy silane, 35 - 90 weight percent water, and 0 - 1 weight percent surfactant.
• the sol-gel composition comprises 2 - 4.0 weight percent glacial acetic acid, 1.75 - 4.0 weight percent metal acetate, 10 - 25 weight percent of an epoxy silane, 65 - 88 weight percent water, and 0 - 0.25 weight percent surfactant.
• aqueous composition for coating metal substrates, such as of aluminum and its alloys, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of: Component Weight Percent
• aqueous composition for coating metal substrates, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, such as of aluminum and its alloys, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, such as of aluminum and its alloys, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• the coating composition may optionally include a solvent, particularly to aid in flowability and wetting ability of the composition.
• the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, such as of aluminum and its alloys, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of: Component Weight Percent
• the coating compositions can be applied onto any suitable surface, such metals and composites, in any suitable manner.
• the coated composition is spray applied over aluminum substrates.
• the coating composition is prepared by combining the water with the acid, the metal acetate, the solvent, and optionally with a surfactant and then within 15 to 60 minutes of use, the silane is added to allow for the hydrolysis of the silane to begin.
• the coating compositions are allowed to air dry at room temperature. Any suitable coating thickness can be employed, however it has been found that coating thicknesses of 0.6 to 2.5 microns have worked particularly well.
• Various embodiments of the present invention include working compositions for direct use in coating metals, as well as concentrates, from which such working compositions can be prepared by dilution with water and/or mixing with other chemically distinct concentrates.
• Various embodiments of the present invention also include processes for treating metals with a composition according to the invention, and may include additional steps that are conventional per se, such as rinsing, conversion coating, and/or painting or some similar overcoating process that puts into place an organic binder containing protective coating over the metal surface treated according to a narrower embodiment of the invention.
• Articles of manufacture including surfaces treated according to a process of the invention are also within the scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
• the present invention comprises a sol-gel composition comprising acid, metal acetate, organosilane, water and optionally a surfactant.
• the sol-gel composition comprises at least, in order of increasing preference 1.75, 1.8, 1.9, 2.0, 2.1 , 2.25, 2.5, 2.75, 3.0, or 3.5 weight percent acid and not more than in increasing order of preference about 8.0, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, or 4.0 weight percent acid; at least, in order of increasing preference 1.5, 1.6, 1.7, 1.75, 1.8, 1.9, 2.0, 2.1 , 2.25, 2.5, 2.75, 3.0, or 3.5 weight percent metal acetate and not more than in increasing order of preference about 8.0, 7.5, 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, or 4.0 weight percent metal acetate; at least, in order of increasing preference 10, 12, 14, 16, 18, 20, 22, 23, 24, or 25 weight percent organos
• the sol-gel composition comprises 2 - 4.0 weight percent acid, 1.75 - 4.0 weight percent metal acetate, 10 - 25 weight percent organosilane, 65 - 88 weight percent water, and 0 - 0.25 weight percent surfactant.
• the pH of the composition is 2.5 - 5, in other embodiments 3 - 4, and in yet other embodiments 3.2 - 3.5.
• Any suitable acid can be used.
• glacial acetic acid is preferred.
• fluorozirconic acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and combinations thereof could be used either in addition to, or in place of, glacial acetic acid.
• metal acetate can be used.
• metal acetates having an oxidation number equal to or greater than 2 have been found to be particularly suitable.
• the metal acetate is zirconium acetate or magnesium acetate, however it should be understood that acetates of other metals, such as cobalt, chrome, manganese and lithium, could be used.
• organosilane Any suitable organosilane can be used.
• organosilanes that are hydrolysable at room temperature have been found to be particularly suitable.
• the organosilane is an epoxy silane or an amine silane.
• any suitable epoxy silane can be used, examples of certain suitable ones include, but are not limited to, glycidoxymethyltrimethoxy silane, 3- glycidoxypropyltrihydroxy silane, 3 -glycidoxypropyl-dimethylhydroxy silane, 3- glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl triethoxysilane, 3- glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropyldimethyl-methoxysilane, 3- glycidoxypropyltributoxysilane, l ,3-bis(glycidoxypropyl) tetramethyldisiloxane, 1 ,3- bis(glycidoxypropyl)tetramethoxydisiloxane, l ,3-bis(glycidoxypropyl)-l ,3-dimethyl-l ,3- dimethoxydisiloxane
• Any suitable amine silane can be used.
• suitable amine silanes include, but are not limited to, 3-aminopropyl trimethoxysilane and 3-aminopropyl triethoxysilane.
• sol-gel components such as solvents, corrosion inhibitors, defoamers, UV-stabilizers, extenders, plasticizers, and pigments as are known in the art, may be included in the composition.
• ethylene glycol monobutyl ether is a particularly suitable solvent.
• suitable solvents include those that have found particular utility in water borne coating technologies. Examples of other suitable solvents include, but are not limited to, alcohols, such as methanol and ethanol, glycols, such as dipropylene glycol, and other glycol ethers, such as propylene glycol monobutyl ether and dipropylene glycol monobutyl ether.
• the present invention comprises a sol-gel composition comprising glacial acetic acid, metal acetate, glycidoxypropyl trimethoxy silane, water and optionally a surfactant.
• the metal acetate is either zirconium acetate, magnesium acetate, or a combination thereof.
• the sol-gel composition comprises 1.75 - 8.0 weight percent glacial acetic acid, 1.5 - 8.0 weight percent metal acetate, 10 - 50 weight percent of an epoxy silane, such as glycidoxypropyl trimethoxy silane, 35 - 90 weight percent water, and 0 - 1 weight percent surfactant.
• the sol-gel composition comprises 2 - 4.0 weight percent glacial acetic acid, 1.75 - 4.0 weight percent metal acetate, 10 - 25 weight percent of an epoxy silane, 65 - 88 weight percent water, and 0 - 0.25 weight percent surfactant.
• aqueous composition for coating metal substrates, such as of aluminum and its alloys, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, such as of aluminum and its alloys, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, such as of aluminum and its alloys, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of: Component Weight Percent
• aqueous composition for coating metal substrates, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• the coating composition may optionally provide a solvent, particularly to aid in flowability and wetting ability of the composition.
• the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• the coating composition may optionally provide a solvent, particularly to aid in flowability and wetting ability of the composition.
• the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• aqueous composition for coating metal substrates, such as of aluminum and its alloys, wherein the aqueous composition comprises, preferably consists essentially of, and more preferably consists of:
• the coating compositions can be applied in any suitable manner onto any suitable metal surface in any suitable manner.
• the coating composition is spray applied over aluminum substrates.
• the coating composition is spray applied over a corrosion resistant coating on a metal substrate.
• the coating composition has been found to be particularly effective as a seal for metal oxide corrosion resistant coatings on aluminum alloy substrates.
• metal oxides of Ti, Zr, Si, Al, Ge and B are preferred, with Ti, Zr, Al and Si being somewhat more preferred, and Ti and Zr being most preferred.
• the use of the coating composition as a seal for oxide (corrosion resistant) coated alloys has been found to be particularly effective at increasing the corrosion resistance of the underlying substrate, particularly substrates of copper containing aluminum alloys, such as AA2024-T3.
• the coating composition can be prepared in any suitable manner.
• the coating composition can generally be prepared by combining the water with the acid with the metal acetate and optionally with a surfactant and then within 15 to 60 minutes of use, the silane is added to allow for the hydrolysis of the silane to begin.
• the coating compositions are allowed to air dry at room temperature. Any suitable coating thickness can be employed, however it has been found that coating thicknesses of 0.6 to 2.5 microns have worked particularly well.
• the sol-gel composition is provided as a 2 component (2K) product.
• the first part (Part A) is comprised of most of the formula, including the acid and the metal acetate.
• the second part (Part B) comprises the silane and optionally any components which do not negatively effect stability of Part B, e.g., those that do not cause silane hydrolysis. These two parts are kept separate until just before application. Upon mixing, the silane begins hydrolysis and the mixture is applied to the substrate.
• the general formula by weight in grams is:
• Part A The following is an exemplary process for making Part A:
• the order of addition is not critical in this product. However, in one embodiment, it is preferred that the acid is added to the water rather than the other way around.
• magnesium acetate it should be added to water so it will dissolve (it is a solid raw material).
• Part B can be added into Part A and mixed. Once the product is mixed, it should be allowed a 30 minute induction time, remixed, and then used. 48] Below are particularly preferred embodiments of sol-gel formulas normalized 00 grams total formula weight or metal portion.
• a suitable composition comprises:
• a panel was prepared by cleaning AA2024-T3 panels with Turco 6849 (20% concentration, at 130° F, for 10 minutes), and deoxidizing with Deoxalume 2310 (15% concentration, room temp, for 5 minutes). The sample was made approximately 30 minutes prior to use, to keep the 'induction time' equal, and to allow for the hydrolysis of the silanes to begin. After 30 minutes, the coating was applied with a spray bottle onto the panel and allowed to air dry in ambient conditions (about 73° F) for 7 days.
• Metal oxide coatings such as titanium oxide and zirconium oxide, are good corrosion resistant coatings on most aluminum alloys.
• AA2024-T3 due to the high copper content, is more of a challenge. It has been found, as will be shown by the following example, that sealing metal oxide coated AA2024-T3 substrate with a sol-gel product allows the total process to surpass the corrosion requirements needed for AA2024-T3 applications. Sealing with sol-gels based on this technology can offer a significant improvement over other types of sealing techniques.
• Metal oxide coated panels were prepared on AA2024-T3 panels (8 inches by 3 inches). The panels were coated with 4 variations of a sol-gel formulation, mainly varied by concentration. [00059] The formula variations can be seen in the table below
• composition B Composition B applied over metal oxide and air dried vertically prior to bake
• H - Composition B applied over metal oxide and directly placed in the oven vertically to bake
• I - Composition C applied over metal oxide and directly placed in the oven vertically to bake
• Sol-gel samples C and D appeared to provide a good seal over metal oxide coated AA2024-T3 panels regardless if the panels were air-dried vertically or horizontally and regardless if they were air dried or went directly into the bake over after sol-gel application.
• the sol-gel coated panels provided corrosion protection to at least 500 hours salt spray hours. This is in excess of salt spray performance of metal oxide alone without a sol-gel seal on such substrates.

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• 2011
  • 2011-06-08 ES ES11731189.4T patent/ES2662122T3/es active Active
  • 2011-06-08 JP JP2013514319A patent/JP5908896B2/ja active Active
  • 2011-06-08 EP EP11731189.4A patent/EP2580372B1/en active Active
  • 2011-06-08 CN CN201180033850.6A patent/CN102985594B/zh not_active Expired - Fee Related
  • 2011-06-08 WO PCT/US2011/039539 patent/WO2011156438A1/en not_active Ceased
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