# US 5,707,465 A · Low temperature corrosion resistant aluminum and aluminum coating composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,707,465 A - Document ID: US5707465A - Status: Granted - Kind: A - Application number: 08/740,200 - Filed: 1996-10-24 - Granted: 1998-01-13 - Earliest claimed: 1996-10-24 - Assignees: Sanchem, Inc. - Inventors: John W. Bibber - Web page: https://patentgrep.com/patent/US5707465A ## CPC - C23C 22/56: Treatment of aluminium or alloys based thereon - C23C 22/34: containing fluorides or complex fluorides - 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 (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) ## Abstract A low temperature aluminum alloy or aluminum corrosion resistant coating has, as essential ingredients, water, 0% hexavalent chromium, an alkali metal permanganate providing at least 760 ppm permanganate, alkali metal or aluminum halide providing at least 100 ppm of halide, and a pH of from about 1.0 to about 4.0. ## Claims ### Claim 1 A low temperature aluminum alloy or aluminum corrosion resistant coating composition comprising as essential ingredients, water, 0% hexavalent chromium, an alkali metal permanganate providing at least 760 ppm permanganate, alkali metal or aluminum halide providing at least 100 ppm of halide, and a pH of from about 1.0 to about 4.0. ### Claim 2 (depends on 1) The composition of claim 1 wherein said low temperature is room temperature. ### Claim 3 (depends on 2) The composition of claim 2 wherein the alkali metal permanganate is selected from the group consisting of sodium permanganate and potassium permanganate, the halide is selected from the group consisting of alkali metal chloride, alkali metal fluoride, alkali metal bromide, alkali metal iodide and aluminum halide. ### Claim 4 (depends on 3) The composition of claim 3 wherein the alkali metal permanganate is potassium permanganate. ### Claim 5 (depends on 4) The composition of claim 4 wherein the halide is selected from sodium chloride, sodium bromide, sodium fluoride, sodium iodide and aluminum chloride. ### Claim 6 (depends on 5) The composition of claim 5 wherein the composition also contains aluminum nitrate. ### Claim 7 A concentrated aluminum alloy or aluminum conversion coating composition for dilution to provide a low temperature conversion coating composition having a pH of from about 1.0 to about 4.0 comprising: 0% hexavalent chromium, alkali metal permanganate in an amount to provide a final aqueous conversion coating composition having at least 760 ppm of permanganate, and a halide in an amount to provide a halide ion concentration of at least about 100 ppm of halide. ### Claim 8 (depends on 7) The composition of claim 7 wherein said low temperature is room temperature. ### Claim 9 (depends on 8) The composition of claim 8 wherein the alkali metal permanganate is selected from the group consisting of sodium permanganate and potassium permanganate, the halide is selected from the group consisting of alkali metal chloride, alkali metal fluoride, alkali metal bromide, alkali metal iodide and aluminum halide. ### Claim 10 (depends on 9) The composition of claim 9 wherein the alkali metal permanganate is potassium permanganate. ### Claim 11 (depends on 10) The composition of claim 10 wherein the halide is selected from sodium chloride, sodium bromide, sodium fluoride, sodium iodide and aluminum chloride. ### Claim 12 (depends on 11) The composition of claim 11 which also contains aluminum nitrate. ### Claim 13 A method of providing a corrosion resistant aluminum alloy or aluminum article that has no pitting when shortly after being coated is placed in a salt-spray at 95.degree. F. according to ASTM specification B-117-94 for 100 hours of exposure comprising; providing a low temperature conversion coating composition having as essential ingredients, water, 0% hexavalent chromium, an alkali metal permanganate providing at least 760 ppm permanganate, alkali metal or aluminum halide providing at least 100 ppm of halide, and a pH of from about 1.0 to about 4.0 coating at said low temperature an aluminum alloy or aluminum article with said coating composition. ### Claim 14 (depends on 13) The method of claim 13 wherein said low temperature is room temperature. ### Claim 15 (depends on 14) The method of claim 14 wherein the alkali metal permanganate is selected from the group consisting of sodium permanganate and potassium permanganate and the halide is selected from the group consisting of alkali metal chloride, alkali metal fluoride, alkali metal bromide, alkali metal iodide and aluminum halide. ### Claim 16 (depends on 15) The method of claim 15 wherein the alkali metal permanganate is potassium permanganate. ### Claim 17 (depends on 16) The method of claim 16 wherein the halide is selected from sodium chloride, sodium bromide, sodium fluoride, sodium iodide and aluminum chloride. ### Claim 18 (depends on 17) The method of claim 17 wherein the composition also contains aluminum nitrate. ### Claim 19 A method of providing a corrosion resistant aluminum alloy article comprising: providing a low temperature conversion coating having as essential ingredients, water, 0% hexavalent chromium, an alkali metal permanganate providing at least 760 ppm permanganate, alkali metal or aluminum halide providing at least 100 ppm of halide, and a pH of from about 1.0 to about 4.0; and coating at said low temperature an aluminum alloy or aluminum article with said coating composition to provide the aluminum alloy or aluminum article that has no pitting when placed in a salt-spray at 95.degree. F. according to ASTM specification B-117 for 100 hours of exposure within 10 minutes of being coated. ### Claim 20 (depends on 19) The composition of claim 19 wherein the alkali metal permanganate is selected from the group consisting of sodium permanganate and potassium permanganate, and the halide is selected from the group consisting of alkali metal chloride, alkali metal fluoride, alkali metal bromide, alkali metal iodide and aluminum halide. ### Claim 21 (depends on 20) The composition of claim 20 wherein the alkali metal permanganate is potassium permanganate. ### Claim 22 (depends on 21) The composition of claim 21 wherein the composition also contains aluminum nitrate.