US1988012A - Metal deposites in oxide coatings - Google Patents
Metal deposites in oxide coatings Download PDFInfo
- Publication number
- US1988012A US1988012A US639850A US63985032A US1988012A US 1988012 A US1988012 A US 1988012A US 639850 A US639850 A US 639850A US 63985032 A US63985032 A US 63985032A US 1988012 A US1988012 A US 1988012A
- Authority
- US
- United States
- Prior art keywords
- solution
- oxide
- aluminum
- metal
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000576 coating method Methods 0.000 title description 45
- 229910052751 metal Inorganic materials 0.000 title description 23
- 239000002184 metal Substances 0.000 title description 23
- 239000000243 solution Substances 0.000 description 50
- 239000011248 coating agent Substances 0.000 description 32
- 229910052782 aluminium Inorganic materials 0.000 description 29
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 29
- 150000003839 salts Chemical class 0.000 description 24
- 239000003638 chemical reducing agent Substances 0.000 description 18
- 238000000034 method Methods 0.000 description 17
- 229910000838 Al alloy Inorganic materials 0.000 description 14
- 239000003463 adsorbent Substances 0.000 description 14
- 238000004040 coloring Methods 0.000 description 11
- 230000001603 reducing effect Effects 0.000 description 10
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 10
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 8
- 229910052709 silver Inorganic materials 0.000 description 7
- 239000004332 silver Substances 0.000 description 7
- FUSNOPLQVRUIIM-UHFFFAOYSA-N 4-amino-2-(4,4-dimethyl-2-oxoimidazolidin-1-yl)-n-[3-(trifluoromethyl)phenyl]pyrimidine-5-carboxamide Chemical compound O=C1NC(C)(C)CN1C(N=C1N)=NC=C1C(=O)NC1=CC=CC(C(F)(F)F)=C1 FUSNOPLQVRUIIM-UHFFFAOYSA-N 0.000 description 6
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 6
- 230000001464 adherent effect Effects 0.000 description 6
- 239000012493 hydrazine sulfate Substances 0.000 description 6
- 229910000377 hydrazine sulfate Inorganic materials 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 238000000151 deposition Methods 0.000 description 5
- 229910001961 silver nitrate Inorganic materials 0.000 description 5
- TUSDEZXZIZRFGC-UHFFFAOYSA-N 1-O-galloyl-3,6-(R)-HHDP-beta-D-glucose Natural products OC1C(O2)COC(=O)C3=CC(O)=C(O)C(O)=C3C3=C(O)C(O)=C(O)C=C3C(=O)OC1C(O)C2OC(=O)C1=CC(O)=C(O)C(O)=C1 TUSDEZXZIZRFGC-UHFFFAOYSA-N 0.000 description 4
- 239000001263 FEMA 3042 Substances 0.000 description 4
- LRBQNJMCXXYXIU-PPKXGCFTSA-N Penta-digallate-beta-D-glucose Natural products OC1=C(O)C(O)=CC(C(=O)OC=2C(=C(O)C=C(C=2)C(=O)OC[C@@H]2[C@H]([C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)O2)OC(=O)C=2C=C(OC(=O)C=3C=C(O)C(O)=C(O)C=3)C(O)=C(O)C=2)O)=C1 LRBQNJMCXXYXIU-PPKXGCFTSA-N 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 229910000365 copper sulfate Inorganic materials 0.000 description 4
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 4
- 239000003792 electrolyte Substances 0.000 description 4
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 4
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 4
- LRBQNJMCXXYXIU-NRMVVENXSA-N tannic acid Chemical compound OC1=C(O)C(O)=CC(C(=O)OC=2C(=C(O)C=C(C=2)C(=O)OC[C@@H]2[C@H]([C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)O2)OC(=O)C=2C=C(OC(=O)C=3C=C(O)C(O)=C(O)C=3)C(O)=C(O)C=2)O)=C1 LRBQNJMCXXYXIU-NRMVVENXSA-N 0.000 description 4
- 229940033123 tannic acid Drugs 0.000 description 4
- 235000015523 tannic acid Nutrition 0.000 description 4
- 229920002258 tannic acid Polymers 0.000 description 4
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 229910052737 gold Inorganic materials 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- GGCZERPQGJTIQP-UHFFFAOYSA-N sodium;9,10-dioxoanthracene-2-sulfonic acid Chemical compound [Na+].C1=CC=C2C(=O)C3=CC(S(=O)(=O)O)=CC=C3C(=O)C2=C1 GGCZERPQGJTIQP-UHFFFAOYSA-N 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 2
- 239000000908 ammonium hydroxide Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- FDWREHZXQUYJFJ-UHFFFAOYSA-M gold monochloride Chemical compound [Cl-].[Au+] FDWREHZXQUYJFJ-UHFFFAOYSA-M 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910000027 potassium carbonate Inorganic materials 0.000 description 2
- KMUONIBRACKNSN-UHFFFAOYSA-N potassium dichromate Chemical compound [K+].[K+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KMUONIBRACKNSN-UHFFFAOYSA-N 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- WQGWDDDVZFFDIG-UHFFFAOYSA-N pyrogallol Chemical compound OC1=CC=CC(O)=C1O WQGWDDDVZFFDIG-UHFFFAOYSA-N 0.000 description 2
- HAAYBYDROVFKPU-UHFFFAOYSA-N silver;azane;nitrate Chemical compound N.N.[Ag+].[O-][N+]([O-])=O HAAYBYDROVFKPU-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 150000001879 copper Chemical class 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- 239000000615 nonconductor Substances 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- SDKPSXWGRWWLKR-UHFFFAOYSA-M sodium;9,10-dioxoanthracene-1-sulfonate Chemical compound [Na+].O=C1C2=CC=CC=C2C(=O)C2=C1C=CC=C2S(=O)(=O)[O-] SDKPSXWGRWWLKR-UHFFFAOYSA-M 0.000 description 1
- 235000000346 sugar Nutrition 0.000 description 1
- 150000008163 sugars Chemical class 0.000 description 1
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
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/82—After-treatment
- C23C22/84—Dyeing
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
- C25D11/02—Anodisation
- C25D11/04—Anodisation of aluminium or alloys based thereon
- C25D11/18—After-treatment, e.g. pore-sealing
- C25D11/24—Chemical after-treatment
Definitions
- This invention relates to the production of decocell, using as an electrolyte a solution of an acid rative coatings on aluminum and aluminum alloy such as sulfuric acid, chromic acid or oxalic acid, surfaces and it is particularly concerned with a is particularly suitable, but satisfactory results method of producing on such surfaces decorative may also be obtained by numerous other methods,
- a satisfactory adsorbent and adherent oxide coatoxide-coated aluminum and aluminum alloy suring may, for example, be obtained by anodic oxifaces to produce colored coatings having properdation of the aluminum article in a solution of 7 ties heretofore unknown in such coatings whereby per cent sulfuric acid bythe application of a curthe utility of the coatings is further increased and rent of 0.01 to 0.4 amperes per square inch of 25 they are made applicable to numerous new uses. anode surface for about minutes at room tem- It is more particularly an object of this invenperature. tion to provide a method for treating oxide-coated After a.
- suitable oxide coating has been formed luminum and aluminum base alloy surfaces to on the aluminum or aluminum alloy surface the 3 produce metallic deposits therein.
- coated metal is treated according to my invention 30
- My invention is predicated upon the discovery to, produce a metallic deposit therein. The that if an aluminum or an aluminum alloy surface metallic deposit is Obtained y reati g the oxideprovided with an oxide coating be treated with coated metal successively with a solution of 2.
- Solutions 61 one or more of certain class of reducible metallic salt and a solution or other metallic Salts and with a reducing agent t suitable form of reducing agent.
- the reducible metallic salt may be reduced in t and t metallic salts must be such salts as are soluble and deposit of free metal obtained in and on the oxide more 168$ reducible in lut o and they must coating.
- the metallic deposit thus produced be capable of complete reduction to the metal.
- This comp p s n a h degree a d a parti ularly bination of properties has heretofore b adaptable to use in the coloring of oxide coatin s known in such coatings, as the oxide coatings according to my invention, but other suitab e themselves are generally considered to be excellent metal Salts y be used-
- the reducing a e t electrical insulators. used may be either in the form of a reducing solu-
- the oxide coatin tion or a reducing gas, or in any other adsorbable may be produced upon the aluminum r al miform, although it is usually preferable to use the 50 num alloy surfaceinany suitable manner whereby d ng agent in ution.
- ducible metallic salt and with the reducing agent I have found that anodic oxidation of the alumiso that these reactants are adsorbed in and on the num or aluminum alloy surface in an electrolytic oxide coating whereby the reducing reaction is 55 produced within and on the oxide coating.
- the reducing action thus obtained deposits finely divided metal within and on the oxide coating.
- the metallic deposits thus produced have characteristic colors which are useful for decorative purposes and which vary with the salts from which they are deposited and the method of their deposition.
- the metal deposits are usually in the state of division approaching colloidal size, and with variation in the size of the particles deposited variance in the shade of the characteristically-colored deposits is produced.
- deposits of silver may be produced having the characteristic color of colloidal silver varying in shade from brown to brownish black.
- Various shades of reddish purple colloidal gold deposits may-also be obtained in this way, as well as yellow colored deposits of colloidal copper.
- the particular shades obtained vary with the salt of the metal first deposited, with the concentration of the solutions used, and with the particular reducing agent applied and its method of application.
- the oxide coating may be first impregnated with a solution of substantially any soluble silver salt, but silver nitrate solutions have been found to be preferable. Particularly satisfactory for this purpose are alkaline solutions of silver nitrate in ammonium hydroxide, the salt in this form being readily reducible to the metal.
- concentrationof the salt solution may vary between wide limits, depending upon the results desired, but it is generally preferable to use solutions containing about 1 to 20 per cent of the salt.
- the reduction of the silver salt is accomplished preferably by immersion of the impregnated oxide coating in a solution of a reducing agent.
- Solutions of reducing sugars, pyrogallic acid, hydroquinone, hydrazine sulfate, formaldehyde, tannic acid, or mixtures of these reducing agents may, for example, be used.
- the reduction may also be made by treatment of the solution-impregnated oxide coating with a reducing gas, such as by treatment with formaldehyde gas.
- the color of the metallic deposit obtained may be varied by reversing the order in which the solutions of reducible metallic salt and the reducing agent are applied to the oxide coating, and in using certain types of metallic salts it is preferable that the order of application of these solutions be reversed from that usually applied. For example, when a simple solution of silver nitrate in water is used it is usually preferable to treat the oxide-coated aluminum surface first with the solution of the reducing agent and subsequently with the solution of the reducible metallic salt, as better results are obtained thereby.
- Copper deposits may be produced from solutions of salts similar to those used for depositing silver. Tannic acid and hydrazine sulfate solutions have been found particularly useful for use as reducing agents in conjunction with a solution of ammoniacal copper sulfate. Gold chloride solutions, preferably alkalinized with potassium carbonate, may alsobe used in conjunction with tannic acid, formaldehyde or other reducing agents to produce deposits of gold.
- Example I An aluminum sheet was first provided on its surface with an adherent and adsorbent oxide coating by subjecting it, as the anode, to the action of a 7 per cent sulfuric acid solution in an electrolytic cell, using a current density of 0.08 amperes per square inch of anode surface.
- An ammoniacal solution of copper sulfate was prepared by adding concentrated ammonium hydroxide to a solution of copper sulfate until the precipitate formed was just re-dissolved. This solution was diluted to a concentration of about 10 per cent.
- As a reducing solution 0.5 grams of hydrazine sulfate was dissolved in 200 cc of water and about 0.5 per cent of caustic soda was added. The oxide-coated sample was immersed in this solution of ammoniacal copper sulfate and then, after rinsing, in the water solution of hydrazine sulfate. A yellow deposit of finely divided copper was thus obtained.
- Example 2 A sample of aluminum sheet was first provided with an oxide coating as described above in Example 1. A solution of 1 per cent silver nitrate was prepared, to which a small amount of potasslum hydroxide was added. Sufiicient ammonia was then added to just re-dissolve the precipitate formed. A reducing solution of hydrazine sulfate was prepared as described in Example 1. The oxide-coated aluminum sample was first immersed in the ammoniacal silver nitrate solution, rinsed, and then immersed in a hydrazine sulfate solution. A brown deposit of colloidal silver was obtained.
- Example 3 An oxide-coated aluminum article was first immersed in a solution containing 2.5 per cent pyrogallic acid and 2.5 per cent sodium thiosulfate or hypo. The article was then rinsed and immersed in a 10 per cent solution of silver nitrate. A very dark brown to black silver deposit was obtained.
- Example 4 A reddish piu'ple color was obtained by depositing gold, in a colloidal or semi-colloidal state of division, in an oxide coating.
- the aluminum article provided on its surface with an oxide coating, was first impregnated with a 10 per cent solution of tannic acid.
- the impregnated coating after rinsing, was then immersed in a solution of gold chloride containing 0.6 per cent of the salt, to which had been added 3 per cent of potassium carbonate.
- the colored oxide coatings thus obtained are substantially permanent and are very suitable for decorating aluminum surfaces, particularly such surfaces as are to be used in exposed positions. In some cases, however, particularly where the lighter colored silver deposits are obtained, there is a tendency for such coatings to change color with exposure to sunlight. This effect may be due to the fact that in such cases a certain amount of unreduced or partially reduced metallic salt remaining in the coating is reduced by the action of the sunlight.
- the term "metal deposits as it has been used throughout this specification must, therefore, be understood to include not only deposits of completely reduced metal but also such mixtures of metal and unreduced or partially reduced metal salts as may be obtained by practicing my invention according to the above descriptlo Having now particularly described and pointed out my invention, what I claim is:
- a method of coloring aluminum or aluminum alloy surfaces comprising producing on such surfaces an adherent and adsorbent oxide coatin and treating said coating successively with a solution of a reducible metallic salt and with a reducing agent.
- a method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises impregnating said oxide coating with a reducible metallic salt and treating said impregnated oxide coating with a reducing agent.
- a method of coloring adsorbent oxide-coated aluminum and aluminum alloy surfaces which comprises depositing finely divided metal therein by treating said coating successively with a solution of a reducible metal salt and with a reducin agent.
- a method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises impregnating said surfaces with a solution of a soluble salt of a metal of the group consistin of copper, silver and gold and with a reducing agent.
- a method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises impregnating the oxide coating with a solution of an ammoniacal silver nitrate and treating said impregnated oxide coating with a reducing agent.
- a method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises impregnating said oxide coating with a solution of a reducing agent and subsequently treating said impregnated oxide coating with" a solution of a soluble silver salt.
- a method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises treating said surfaces successively with a solution of a soluble copper salt and with a reducing agent.
- a method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises treating said coating successively with a solution of a soluble gold salt and with a reducing agent.
- a method of coloring aluminum or aluminum alloy surfaces comprising producing on such surfaces an adherent and adsorbent oxide coating, and treating said coating with solutions of va reducible salt and a reducing agent capable of reducing said salt, by first absorbing material from one of said solutions in the coating and then treating with the other solution.
Description
Patented Jan. 15, 1935 1,988,012
METAL DEPOSITS IN OXIDE COATINGS Ralph Bryant Mason, New Kensington, Pa., as-
signor to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania No Drawing. Application October 27, 1932 Serial No. 639,850
9 Claims. (Cl. 148-45) This invention relates to the production of decocell, using as an electrolyte a solution of an acid rative coatings on aluminum and aluminum alloy such as sulfuric acid, chromic acid or oxalic acid, surfaces and it is particularly concerned with a is particularly suitable, but satisfactory results method of producing on such surfaces decorative may also be obtained by numerous other methods,
coatings in which the color eifects are obtained such for example as by simple immersion of the I by the deposition of metal. aluminum article in a solution of sodium car- Numerous recently-developed methods of probonate and potassium dichromate or similar oxiducing coatings which consist substantially of dizing solution without the application of electrialuminum oxide on the surfaces of aluminum and cal energy. Anodic oxidation is to be preferred,
10 aluminum base alloys have extended the applicahowever, as harder, more adherent coatings 10 tion of these metals to various uses and to the possessed of better adsorbent properties are proproduction of various articles for which they were duced. Particularly good results may be obtained heretofore considered unsatisfactory. These soby making aluminum or aluminum base alloy arcalled oxide coatings, being dense and adherent, ticles to be coated the anode in an electrolytic protect the surfaces of the metal from corrosion cell, using as the electrolyte a solution of sulfuric l5 and, being more or less porous and adsorbent, lend acid. The conditions of temperature, time and themselves to the production of decorative effects current density used for the oxidation vary with on metal surfaces by the coloring of the oxide the concentration of the electrolyte used, and coating, when using sulfuric acid electrolytes, concentra- It is an object of this invention to provide a new tions of about 1 to 70 per cent acid may be used. 20 and improved method for the treatment of such A satisfactory adsorbent and adherent oxide coatoxide-coated aluminum and aluminum alloy suring may, for example, be obtained by anodic oxifaces to produce colored coatings having properdation of the aluminum article in a solution of 7 ties heretofore unknown in such coatings whereby per cent sulfuric acid bythe application of a curthe utility of the coatings is further increased and rent of 0.01 to 0.4 amperes per square inch of 25 they are made applicable to numerous new uses. anode surface for about minutes at room tem- It is more particularly an object of this invenperature. tion to provide a method for treating oxide-coated After a. suitable oxide coating has been formed luminum and aluminum base alloy surfaces to on the aluminum or aluminum alloy surface the 3 produce metallic deposits therein. coated metal is treated according to my invention 30 My invention is predicated upon the discovery to, produce a metallic deposit therein. The that if an aluminum or an aluminum alloy surface metallic deposit is Obtained y reati g the oxideprovided with an oxide coating be treated with coated metal successively with a solution of 2.
Solutions 61 one or more of certain class of reducible metallic salt and a solution or other metallic Salts and with a reducing agent t suitable form of reducing agent. The reducible metallic salt may be reduced in t and t metallic salts must be such salts as are soluble and deposit of free metal obtained in and on the oxide more 168$ reducible in lut o and they must coating. The metallic deposit thus produced be capable of complete reduction to the metal.
parts to the oxide coating a characteristic color The self-s of the metals of the oup o oup 1 '40 and it modifies the properties of t coating by of the Mendelejeif periodic system, copper, silver 40 increasing its corrosion resistance and by impartand gol Sometimes designated 35 the pp r ing to it the property of. conducting electricity, r up m a hav been f u d to p ss ss these although its resistance may be high. This comp p s n a h degree a d a parti ularly bination of properties has heretofore b adaptable to use in the coloring of oxide coatin s known in such coatings, as the oxide coatings according to my invention, but other suitab e themselves are generally considered to be excellent metal Salts y be used- The reducing a e t electrical insulators. used may be either in the form of a reducing solu- In carrying out my invention the oxide coatin tion or a reducing gas, or in any other adsorbable may be produced upon the aluminum r al miform, although it is usually preferable to use the 50 num alloy surfaceinany suitable manner whereby d ng agent in ution. The oxide-coated there is obtained a relatively hard, porous, adaluminum is treated with the solution of the reherent and adsorbent coating. For this purpose ducible metallic salt and with the reducing agent I have found that anodic oxidation of the alumiso that these reactants are adsorbed in and on the num or aluminum alloy surface in an electrolytic oxide coating whereby the reducing reaction is 55 produced within and on the oxide coating. The reducing action thus obtained deposits finely divided metal within and on the oxide coating.
The metallic deposits thus produced have characteristic colors which are useful for decorative purposes and which vary with the salts from which they are deposited and the method of their deposition. The metal deposits are usually in the state of division approaching colloidal size, and with variation in the size of the particles deposited variance in the shade of the characteristically-colored deposits is produced. For example, deposits of silver may be produced having the characteristic color of colloidal silver varying in shade from brown to brownish black. Various shades of reddish purple colloidal gold deposits may-also be obtained in this way, as well as yellow colored deposits of colloidal copper. The particular shades obtained vary with the salt of the metal first deposited, with the concentration of the solutions used, and with the particular reducing agent applied and its method of application.
In producing silver deposits the oxide coating may be first impregnated with a solution of substantially any soluble silver salt, but silver nitrate solutions have been found to be preferable. Particularly satisfactory for this purpose are alkaline solutions of silver nitrate in ammonium hydroxide, the salt in this form being readily reducible to the metal. The concentrationof the salt solution may vary between wide limits, depending upon the results desired, but it is generally preferable to use solutions containing about 1 to 20 per cent of the salt. The reduction of the silver salt is accomplished preferably by immersion of the impregnated oxide coating in a solution of a reducing agent. Solutions of reducing sugars, pyrogallic acid, hydroquinone, hydrazine sulfate, formaldehyde, tannic acid, or mixtures of these reducing agents may, for example, be used. The reduction may also be made by treatment of the solution-impregnated oxide coating with a reducing gas, such as by treatment with formaldehyde gas. The color of the metallic deposit obtained may be varied by reversing the order in which the solutions of reducible metallic salt and the reducing agent are applied to the oxide coating, and in using certain types of metallic salts it is preferable that the order of application of these solutions be reversed from that usually applied. For example, when a simple solution of silver nitrate in water is used it is usually preferable to treat the oxide-coated aluminum surface first with the solution of the reducing agent and subsequently with the solution of the reducible metallic salt, as better results are obtained thereby.
Copper deposits may be produced from solutions of salts similar to those used for depositing silver. Tannic acid and hydrazine sulfate solutions have been found particularly useful for use as reducing agents in conjunction with a solution of ammoniacal copper sulfate. Gold chloride solutions, preferably alkalinized with potassium carbonate, may alsobe used in conjunction with tannic acid, formaldehyde or other reducing agents to produce deposits of gold.
In the following examples, there are set out more specifically the results which may be obtained by my process, and the variations in color and shade resulting from varied conditions of operation.
Example I An aluminum sheet was first provided on its surface with an adherent and adsorbent oxide coating by subjecting it, as the anode, to the action of a 7 per cent sulfuric acid solution in an electrolytic cell, using a current density of 0.08 amperes per square inch of anode surface. An ammoniacal solution of copper sulfate was prepared by adding concentrated ammonium hydroxide to a solution of copper sulfate until the precipitate formed was just re-dissolved. This solution was diluted to a concentration of about 10 per cent. As a reducing solution, 0.5 grams of hydrazine sulfate was dissolved in 200 cc of water and about 0.5 per cent of caustic soda was added. The oxide-coated sample was immersed in this solution of ammoniacal copper sulfate and then, after rinsing, in the water solution of hydrazine sulfate. A yellow deposit of finely divided copper was thus obtained.
Example 2 A sample of aluminum sheet was first provided with an oxide coating as described above in Example 1. A solution of 1 per cent silver nitrate was prepared, to which a small amount of potasslum hydroxide was added. Sufiicient ammonia was then added to just re-dissolve the precipitate formed. A reducing solution of hydrazine sulfate was prepared as described in Example 1. The oxide-coated aluminum sample was first immersed in the ammoniacal silver nitrate solution, rinsed, and then immersed in a hydrazine sulfate solution. A brown deposit of colloidal silver was obtained.
Example 3 An oxide-coated aluminum article was first immersed in a solution containing 2.5 per cent pyrogallic acid and 2.5 per cent sodium thiosulfate or hypo. The article was then rinsed and immersed in a 10 per cent solution of silver nitrate. A very dark brown to black silver deposit was obtained.
Example 4 A reddish piu'ple color was obtained by depositing gold, in a colloidal or semi-colloidal state of division, in an oxide coating. In producing this color the aluminum article, provided on its surface with an oxide coating, was first impregnated with a 10 per cent solution of tannic acid. The impregnated coating, after rinsing, was then immersed in a solution of gold chloride containing 0.6 per cent of the salt, to which had been added 3 per cent of potassium carbonate.
The colored oxide coatings thus obtained are substantially permanent and are very suitable for decorating aluminum surfaces, particularly such surfaces as are to be used in exposed positions. In some cases, however, particularly where the lighter colored silver deposits are obtained, there is a tendency for such coatings to change color with exposure to sunlight. This effect may be due to the fact that in such cases a certain amount of unreduced or partially reduced metallic salt remaining in the coating is reduced by the action of the sunlight. The term "metal deposits as it has been used throughout this specification must, therefore, be understood to include not only deposits of completely reduced metal but also such mixtures of metal and unreduced or partially reduced metal salts as may be obtained by practicing my invention according to the above descriptlo Having now particularly described and pointed out my invention, what I claim is:
1. A method of coloring aluminum or aluminum alloy surfaces comprising producing on such surfaces an adherent and adsorbent oxide coatin and treating said coating successively with a solution of a reducible metallic salt and with a reducing agent.
2. A method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises impregnating said oxide coating with a reducible metallic salt and treating said impregnated oxide coating with a reducing agent.
3. A method of coloring adsorbent oxide-coated aluminum and aluminum alloy surfaces which comprises depositing finely divided metal therein by treating said coating successively with a solution of a reducible metal salt and with a reducin agent.
4. A method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises impregnating said surfaces with a solution of a soluble salt of a metal of the group consistin of copper, silver and gold and with a reducing agent.
5. A method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises impregnating the oxide coating with a solution of an ammoniacal silver nitrate and treating said impregnated oxide coating with a reducing agent.
6. A method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises impregnating said oxide coating with a solution of a reducing agent and subsequently treating said impregnated oxide coating with" a solution of a soluble silver salt.
'I. A method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises treating said surfaces successively with a solution of a soluble copper salt and with a reducing agent.
8. A method of coloring adsorbent oxide-coated aluminum or aluminum alloy surfaces which comprises treating said coating successively with a solution of a soluble gold salt and with a reducing agent. 1
' 9. A method of coloring aluminum or aluminum alloy surfaces comprising producing on such surfaces an adherent and adsorbent oxide coating, and treating said coating with solutions of va reducible salt and a reducing agent capable of reducing said salt, by first absorbing material from one of said solutions in the coating and then treating with the other solution.
RALPH BRYANT MASON.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US639850A US1988012A (en) | 1932-10-27 | 1932-10-27 | Metal deposites in oxide coatings |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US639850A US1988012A (en) | 1932-10-27 | 1932-10-27 | Metal deposites in oxide coatings |
Publications (1)
Publication Number | Publication Date |
---|---|
US1988012A true US1988012A (en) | 1935-01-15 |
Family
ID=24565814
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US639850A Expired - Lifetime US1988012A (en) | 1932-10-27 | 1932-10-27 | Metal deposites in oxide coatings |
Country Status (1)
Country | Link |
---|---|
US (1) | US1988012A (en) |
Cited By (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2483510A (en) * | 1945-04-14 | 1949-10-04 | United Chromium Inc | Composition for dip coating solution and dip process for coloring zinc |
US2496649A (en) * | 1947-05-06 | 1950-02-07 | Aluminum Co Of America | Treatment of oxide coatings on aluminum |
US2639226A (en) * | 1951-08-27 | 1953-05-19 | Hall Brothers Inc | Method of staining embossing plates |
US2681524A (en) * | 1951-10-05 | 1954-06-22 | Edwin A Neugass | Illuminated panel |
US2682251A (en) * | 1951-10-25 | 1954-06-29 | Edwin A Neugass | Illuminated knob |
US2710804A (en) * | 1949-08-08 | 1955-06-14 | Von Glutz & Muller Ag Dr | Process for the production of photographic reproduction surfaces on aluminium and its alloys |
US2769265A (en) * | 1947-06-18 | 1956-11-06 | Boeing Co | Metal foil appliques and method of making same |
US3017285A (en) * | 1959-05-29 | 1962-01-16 | Horizons Inc | Method of writing on anodized aluminum |
US3032435A (en) * | 1958-07-17 | 1962-05-01 | Knapsack Greisheim Ag | Process for improving the corrosion resistance of pieces of light metals and light metal alloys |
US3108932A (en) * | 1959-05-29 | 1963-10-29 | Horizons Inc | Method of writing on unsealed anodized aluminum |
US4043880A (en) * | 1975-07-24 | 1977-08-23 | Sumitomo Aluminum Smelting Co., Ltd. | Method for producing green-colored anodic oxide film on aluminum or aluminum base alloy articles |
EP0011771A1 (en) * | 1978-11-25 | 1980-06-11 | Agfa-Gevaert AG | Anodised aluminium rolls with improved electrical conductibility and method of manufacturing the same |
US4518467A (en) * | 1981-06-01 | 1985-05-21 | Inco Selective Surfaces Limited | Selective solar surfaces |
US5358623A (en) * | 1993-04-21 | 1994-10-25 | Sanchem, Inc. | Corrosion resistant anodized aluminum |
US5554231A (en) * | 1993-04-21 | 1996-09-10 | Sanchem, Inc. | Corrosion resistant aluminum and aluminum coating |
US5707465A (en) * | 1996-10-24 | 1998-01-13 | Sanchem, Inc. | Low temperature corrosion resistant aluminum and aluminum coating composition |
US20050181137A1 (en) * | 2004-02-17 | 2005-08-18 | Straus Martin L. | Corrosion resistant, zinc coated articles |
US20050181230A1 (en) * | 2004-02-17 | 2005-08-18 | Straus Martin L. | Corrosion resistant, zinc coated articles |
US20110005287A1 (en) * | 2008-09-30 | 2011-01-13 | Bibber Sr John | Method for improving light gauge building materials |
US8709355B2 (en) * | 2003-02-18 | 2014-04-29 | Intel Corporation | Microfluidic system incorporating a metal impregnated nanoporous material in a microfluidic pathway thereof |
-
1932
- 1932-10-27 US US639850A patent/US1988012A/en not_active Expired - Lifetime
Cited By (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2483510A (en) * | 1945-04-14 | 1949-10-04 | United Chromium Inc | Composition for dip coating solution and dip process for coloring zinc |
US2496649A (en) * | 1947-05-06 | 1950-02-07 | Aluminum Co Of America | Treatment of oxide coatings on aluminum |
US2769265A (en) * | 1947-06-18 | 1956-11-06 | Boeing Co | Metal foil appliques and method of making same |
US2710804A (en) * | 1949-08-08 | 1955-06-14 | Von Glutz & Muller Ag Dr | Process for the production of photographic reproduction surfaces on aluminium and its alloys |
US2639226A (en) * | 1951-08-27 | 1953-05-19 | Hall Brothers Inc | Method of staining embossing plates |
US2681524A (en) * | 1951-10-05 | 1954-06-22 | Edwin A Neugass | Illuminated panel |
US2682251A (en) * | 1951-10-25 | 1954-06-29 | Edwin A Neugass | Illuminated knob |
US3032435A (en) * | 1958-07-17 | 1962-05-01 | Knapsack Greisheim Ag | Process for improving the corrosion resistance of pieces of light metals and light metal alloys |
US3017285A (en) * | 1959-05-29 | 1962-01-16 | Horizons Inc | Method of writing on anodized aluminum |
US3108932A (en) * | 1959-05-29 | 1963-10-29 | Horizons Inc | Method of writing on unsealed anodized aluminum |
US4043880A (en) * | 1975-07-24 | 1977-08-23 | Sumitomo Aluminum Smelting Co., Ltd. | Method for producing green-colored anodic oxide film on aluminum or aluminum base alloy articles |
EP0011771A1 (en) * | 1978-11-25 | 1980-06-11 | Agfa-Gevaert AG | Anodised aluminium rolls with improved electrical conductibility and method of manufacturing the same |
US4288469A (en) * | 1978-11-25 | 1981-09-08 | Agfa-Gevaert Aktiengesellschaft | Anodized aluminium rollers with improved electrical conductivity and a process for their manufacture |
US4518467A (en) * | 1981-06-01 | 1985-05-21 | Inco Selective Surfaces Limited | Selective solar surfaces |
US5358623A (en) * | 1993-04-21 | 1994-10-25 | Sanchem, Inc. | Corrosion resistant anodized aluminum |
US5554231A (en) * | 1993-04-21 | 1996-09-10 | Sanchem, Inc. | Corrosion resistant aluminum and aluminum coating |
US5707465A (en) * | 1996-10-24 | 1998-01-13 | Sanchem, Inc. | Low temperature corrosion resistant aluminum and aluminum coating composition |
US8709355B2 (en) * | 2003-02-18 | 2014-04-29 | Intel Corporation | Microfluidic system incorporating a metal impregnated nanoporous material in a microfluidic pathway thereof |
US20050181137A1 (en) * | 2004-02-17 | 2005-08-18 | Straus Martin L. | Corrosion resistant, zinc coated articles |
US20050181230A1 (en) * | 2004-02-17 | 2005-08-18 | Straus Martin L. | Corrosion resistant, zinc coated articles |
US20110005287A1 (en) * | 2008-09-30 | 2011-01-13 | Bibber Sr John | Method for improving light gauge building materials |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US1988012A (en) | Metal deposites in oxide coatings | |
US2018388A (en) | Treating aluminum and aluminum alloy surfaces | |
US3382160A (en) | Process for inorganically coloring aluminum | |
US4392920A (en) | Method of forming oxide coatings | |
US1551613A (en) | Coated aluminum articles and process and means for producing same | |
US2588734A (en) | Pretreatment of beryllium prior to coating | |
US2987417A (en) | Pigmenting aluminum oxide coating | |
GB1272536A (en) | Electroplating solutions and process for electroplating using such solutions | |
US1965269A (en) | Method of coloring aluminum | |
US4137132A (en) | Chromite coatings, electrolytes, and electrolytic method of forming the coatings | |
US3661729A (en) | Process for coloring anodic coatings on aluminum and aluminum alloys with metal salts | |
US4018628A (en) | Process for coloring aluminium | |
US2499231A (en) | Method of producing surface conversion coatings on zinc | |
US1946153A (en) | Protecting aluminum from corrosion | |
US1798218A (en) | Coating and coloring metals | |
US2548419A (en) | Method for production of lustrous zinc | |
US2975073A (en) | Corrosion resistance of electroless nickel plate | |
US2290364A (en) | Surface treatment of aluminum or aluminum alloys | |
US2272216A (en) | Method of coating copper and its alloys | |
US4199417A (en) | Electrodeposition of black deposit and electrolytes therefor | |
US2812297A (en) | Method of preventing etching by chromic acid chromium plating baths | |
JPS60190588A (en) | Method for blackening zinc or zinc alloy plated steel sheet | |
US2431728A (en) | Treatment of ferrous metals to improve resistance to rusting | |
JPS61253383A (en) | Formation of black film | |
US2639264A (en) | Vitreous enameling processes and products |