US3314811A - Metal treating compositions and processes - Google Patents
Metal treating compositions and processes Download PDFInfo
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- US3314811A US3314811A US335393A US33539364A US3314811A US 3314811 A US3314811 A US 3314811A US 335393 A US335393 A US 335393A US 33539364 A US33539364 A US 33539364A US 3314811 A US3314811 A US 3314811A
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- aluminum
- blackening
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- 239000000203 mixture Substances 0.000 title claims description 46
- 229910052751 metal Inorganic materials 0.000 title claims description 25
- 239000002184 metal Substances 0.000 title claims description 25
- 238000000034 method Methods 0.000 title claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 63
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 63
- 150000001875 compounds Chemical class 0.000 claims description 28
- 150000003839 salts Chemical class 0.000 claims description 15
- 239000011593 sulfur Substances 0.000 claims description 15
- 229910052717 sulfur Inorganic materials 0.000 claims description 15
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 9
- 239000000243 solution Substances 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 239000007795 chemical reaction product Substances 0.000 claims description 6
- 239000007864 aqueous solution Substances 0.000 claims description 5
- MEFBJEMVZONFCJ-UHFFFAOYSA-N molybdate Chemical compound [O-][Mo]([O-])(=O)=O MEFBJEMVZONFCJ-UHFFFAOYSA-N 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 238000000576 coating method Methods 0.000 description 18
- 235000002639 sodium chloride Nutrition 0.000 description 14
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical group [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 11
- 239000011248 coating agent Substances 0.000 description 8
- 150000002739 metals Chemical class 0.000 description 7
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 6
- 239000004615 ingredient Substances 0.000 description 6
- 239000003921 oil Substances 0.000 description 6
- 239000001993 wax Substances 0.000 description 6
- 150000001805 chlorine compounds Chemical class 0.000 description 5
- 239000011253 protective coating Substances 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- JKQOBWVOAYFWKG-UHFFFAOYSA-N molybdenum trioxide Chemical compound O=[Mo](=O)=O JKQOBWVOAYFWKG-UHFFFAOYSA-N 0.000 description 4
- VLAPMBHFAWRUQP-UHFFFAOYSA-L molybdic acid Chemical compound O[Mo](O)(=O)=O VLAPMBHFAWRUQP-UHFFFAOYSA-L 0.000 description 4
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 description 4
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 229910001514 alkali metal chloride Inorganic materials 0.000 description 3
- 235000019270 ammonium chloride Nutrition 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 150000003464 sulfur compounds Chemical class 0.000 description 3
- YXIWHUQXZSMYRE-UHFFFAOYSA-N 1,3-benzothiazole-2-thiol Chemical compound C1=CC=C2SC(S)=NC2=C1 YXIWHUQXZSMYRE-UHFFFAOYSA-N 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- ZMZDMBWJUHKJPS-UHFFFAOYSA-M Thiocyanate anion Chemical compound [S-]C#N ZMZDMBWJUHKJPS-UHFFFAOYSA-M 0.000 description 2
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 2
- 238000007743 anodising Methods 0.000 description 2
- AFZSMODLJJCVPP-UHFFFAOYSA-N dibenzothiazol-2-yl disulfide Chemical compound C1=CC=C2SC(SSC=3SC4=CC=CC=C4N=3)=NC2=C1 AFZSMODLJJCVPP-UHFFFAOYSA-N 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 2
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 2
- ZMZDMBWJUHKJPS-UHFFFAOYSA-N hydrogen thiocyanate Natural products SC#N ZMZDMBWJUHKJPS-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- DHCDFWKWKRSZHF-UHFFFAOYSA-L thiosulfate(2-) Chemical compound [O-]S([S-])(=O)=O DHCDFWKWKRSZHF-UHFFFAOYSA-L 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 1
- 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
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000002535 acidifier Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- APUPEJJSWDHEBO-UHFFFAOYSA-P ammonium molybdate Chemical compound [NH4+].[NH4+].[O-][Mo]([O-])(=O)=O APUPEJJSWDHEBO-UHFFFAOYSA-P 0.000 description 1
- 235000018660 ammonium molybdate Nutrition 0.000 description 1
- 239000011609 ammonium molybdate Substances 0.000 description 1
- 229940010552 ammonium molybdate Drugs 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GSOLWAFGMNOBSY-UHFFFAOYSA-N cobalt Chemical compound [Co][Co][Co][Co][Co][Co][Co][Co] GSOLWAFGMNOBSY-UHFFFAOYSA-N 0.000 description 1
- 235000013495 cobalt Nutrition 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- -1 dichromates Chemical class 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 235000011167 hydrochloric acid Nutrition 0.000 description 1
- NIBXJCYCRLUCEJ-UHFFFAOYSA-M hydrogenmolybdate Chemical compound O[Mo]([O-])(=O)=O NIBXJCYCRLUCEJ-UHFFFAOYSA-M 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052976 metal sulfide Inorganic materials 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 230000009972 noncorrosive effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 239000001103 potassium chloride Substances 0.000 description 1
- 235000011164 potassium chloride Nutrition 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011342 resin composition Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- WBHQBSYUUJJSRZ-UHFFFAOYSA-M sodium bisulfate Chemical compound [Na+].OS([O-])(=O)=O WBHQBSYUUJJSRZ-UHFFFAOYSA-M 0.000 description 1
- 229910000342 sodium bisulfate Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- CSMWJXBSXGUPGY-UHFFFAOYSA-L sodium dithionate Chemical compound [Na+].[Na+].[O-]S(=O)(=O)S([O-])(=O)=O CSMWJXBSXGUPGY-UHFFFAOYSA-L 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- VGTPCRGMBIAPIM-UHFFFAOYSA-M sodium thiocyanate Chemical compound [Na+].[S-]C#N VGTPCRGMBIAPIM-UHFFFAOYSA-M 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 150000004763 sulfides Chemical class 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 150000003567 thiocyanates Chemical class 0.000 description 1
- 150000004764 thiosulfuric acid derivatives Chemical class 0.000 description 1
- 150000003585 thioureas Chemical class 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 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
- C23C22/05—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 using aqueous solutions
- C23C22/06—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 using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/40—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 using aqueous solutions using aqueous acidic solutions with pH less than 6 containing molybdates, tungstates or vanadates
- C23C22/44—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 using aqueous solutions using aqueous acidic solutions with pH less than 6 containing molybdates, tungstates or vanadates containing also fluorides or complex fluorides
Definitions
- Suitable chlorine compounds include the alkali metal chlorides such as sodium chloride and potassium chloride, ammonium chloride, hydrochloric acid and the like watersoluble ionizable chlorides.
- Water-soluble sulfur-bearing compounds found suitable for the formation of black metal sulfur react-ion products in an acid medium include sulfides, thiocyanates, thiosulfates, thioureas, Z-mercaptobenzothiazole, benzothiazyl disulfide, Z-me-rcaptoimidazoline and the like, and including most preferably sodium thiocyanate, sodium sulfide, sodium hyposulfate and the like.
- This preferred blackening composition include at least two chemicals which affect the aluminum surface in different manners to render it receptive to the deposit of blacking agents. These chemicals are the chlorides which tend to etch or otherwise attack the aluminum surface, and the salts of metals below aluminum in the electromotive series which displace the aluminum to form a metallic film which is reactive to form black metal sulfur compounds or complexes on the surface thereof.
- the composition also includes at least two blackening compounds, one of which deposits black molybdic oxide on the aluminum and the other of which contains sulfur and is reactive with the deposited metal film to form the black metal sulfur compounds or complexes.
- Range in Percent by Weight Ingredient Broad Preferred Molybdic acid or salt 2 to 25 3 to 10 Metal salt 3 to 40 3 to 20 Water-soluble chloride. 40 to 80 50 to G Sulfur-bearing compound 0. 5 to 20 1 to 5 Acid 5 to 60 to 30 Fluorine-bearing compoun 0 to 5 to 15
- the following example is illustrative of a preferred composition for However the specific ingredients and proportions are set forth as illustrative and should not be considered limitative, possible variations being clear to those skilled in the art in the light of the disclosure set out hereinbefore in connection with the previous formulation.
- the aluminum pieces are immersed in the blackening composition for a period of from 1 to minutes depending upon the specific acidity of the solution and its temperature. Generally an immersion time of from 10 to 15 minutes is sufficient to form a dark black deposit which is smooth and even and which is firmly anchored to the aluminum surface.
- the aluminum is removed from the composition and washed or rinsed.
- the blackened aluminum pieces are immersed in any conventional wax, oil or resin composition to deposit over the blackened surface a protective coating or shield.
- any conventional wax, oil or resin composition to deposit over the blackened surface a protective coating or shield.
- water-ionizable chloride is selected from the group consisting of alkali metal chlorides, ammonium chloride and hydrogen chloride.
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- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
Description
United States Patent 3,314,811 METAL TREATING COMPOSITIONS AND PROCESSES Abraham J. Mitchell, Stratford, and Paul R. Jarvi, Orange,
This invention relates to the art of blackening aluminum surfaces or surfaces of aluminum alloy metals in which aluminum is the major ingredient, and to the novel aluminum blackening compositions for accomplishing this result.
Aluminum and its alloys are of ever-increasing importance for the fabrication of countless items because of the lightness, workability, strength and other inherent properties of these metals.
Aluminum has a bright metallic surface which is not receptive to or retentive of applied colored coatings or protective coatings of oil or wax and which becomes whitish in color upon prolonged exposure to the atmosphere due to the oxidation of the aluminum to form a white aluminum oxide surface coating.
It is well known to electrolytically plate or anodize aluminum to form thereon a non-corrosive non-oxidizable coating which protects the underlying aluminum against contact with the atmosphere and which in turn may be dyed any desired color. While such anodizing processes are effective in accomplishing the desired results, they are nevertheless slow, costly and unavailable to those who do not possess electroplating equipment.
It is an object of the present invention to provide an aluminum blackening composition which may be applied at room temperatures or any higher or more convenient temperatures by conventional immersion techniques and in the absence of applied current to form on the aluminum surface black coatings which are strongly bonded and which resist chalking or flaking off.
It is another object of this invention to provide a rapid and inexpensive process for applying coatings to aluminum which are receptive to and retentive of protective wax or oil coatings without the disadvantages of the electrolytic anodizing process.
These and other objects and advantages are accomplished by the present invention as Will be clear to those skilled in the art in the light of the following description.
The essence of the present invention resides in the discovery of an aqueous solution of certain water-soluble compounds which cooperate to deposit black or off-black coatings on aluminum surfaces which are immersed therein for relatively short periods of time and at relatively low temperatures.
The aqueous blackening compositions of the present invention are acidic aqueous solutions which contain a mixture of compounds which react with the aluminum surface to render it receptive to the blackening compound, and a mixture of blackening compounds selected from the group consisting of molybdic acid and salts thereof and sulfur-bearing compound-s.
It appears that this preferred composition fulfills a twofold etfect in which the aluminum surface is both etched and coated with a metallic coating, the etching step rendering the surface receptive to the deposit of black molybdic oxide and the metallic coating step forming a Cit with a sulfur-bearing compound reaction product which appears coating which is reactive to form the black or gray to be a sulfide.
The first blackening combination in the mixture comprises a water-soluble chlorine compound which ionizes to form chloride ions which function to etch or otherwise roughen the aluminum surface, and molybdic acid or the water-soluble salts thereof which function to deposit black molybdic oxide on the roughened aluminum surface. This combination of materials when used in an aqueous solution having a pH of about 6.5 or less has. been found to form black coatings which are firmly bonded to aluminum.
Suitable chlorine compounds include the alkali metal chlorides such as sodium chloride and potassium chloride, ammonium chloride, hydrochloric acid and the like watersoluble ionizable chlorides.
Suitable molybdic oxide liberating compounds are molybdic acid or hydrogen molybdate and the water-soluble salt-s thereof such as the alkali metal molybdates including sodium molybate and potassium molybdate, ammonium molybdate and the like.
The second blackening combination of the mixture encompassed by the present invention comprises the watersoluble salt of a metal below aluminum in the electromotive series, and a watersoluble sulfur-bearing compound.
The metal salt ionizes in solution to form metal cations which deposit in an acid medium on the aluminum surface to form a surface film which appears to be receptive to or reactive to form black metal sulfur compounds or complexes.
Metal salts found suitable for treating the aluminum surface to render it receptive to black metal sulfide deposits include the salts as broadly defined and more specifically includes the sulfates, dichromates, nitrates, chlorides, acetates and other watensol-uble salts of metals such as nickel, chromium, cob-alt, antimony, bismuth, arsenic and any of the other metals which have a lower electrode potential than aluminum and are therefore below aluminum in the elect-rom-otive series and which are therefore replaced from their salts by aluminum.
Water-soluble sulfur-bearing compounds found suitable for the formation of black metal sulfur react-ion products in an acid medium include sulfides, thiocyanates, thiosulfates, thioureas, Z-mercaptobenzothiazole, benzothiazyl disulfide, Z-me-rcaptoimidazoline and the like, and including most preferably sodium thiocyanate, sodium sulfide, sodium hyposulfate and the like.
According to the present invention, an aqueous blackening composition is formulated so as to include both blackening compositions heretofore set out. It has been found that when a single blackening composition is so formulated it provides a bath which blackens aluminum more deeply and more evenly and smoothly than is possible using either of the other compositions alone. From these standpoints the behavior of the combination aqueous blackening composition is synergistic.
This preferred blackening composition include at least two chemicals which affect the aluminum surface in different manners to render it receptive to the deposit of blacking agents. These chemicals are the chlorides which tend to etch or otherwise attack the aluminum surface, and the salts of metals below aluminum in the electromotive series which displace the aluminum to form a metallic film which is reactive to form black metal sulfur compounds or complexes on the surface thereof.
The composition also includes at least two blackening compounds, one of which deposits black molybdic oxide on the aluminum and the other of which contains sulfur and is reactive with the deposited metal film to form the black metal sulfur compounds or complexes.
The blackening compositions contain the following ingredients in the following proportions:
Range in Percent by Weight Ingredient Broad Preferred Molybdic acid or salt 2 to 25 3 to 10 Metal salt 3 to 40 3 to 20 Water-soluble chloride. 40 to 80 50 to G Sulfur-bearing compound 0. 5 to 20 1 to 5 Acid 5 to 60 to 30 Fluorine-bearing compoun 0 to 5 to 15 The following example is illustrative of a preferred composition for However the specific ingredients and proportions are set forth as illustrative and should not be considered limitative, possible variations being clear to those skilled in the art in the light of the disclosure set out hereinbefore in connection with the previous formulation.
These ingredients are dissolved in water in a concentration ranging from about 1 ounce per gallon up to about 3 or more pounds per gallon depending upon the results desired. In most cases it is preferred to use a concentration in the area of from 2 to 10 ounces per gallon and most preferably about 6 ounces per gallon of water. 1
The fluoride ingredient is found to cooperate with the chloride in etching the aluminum surface. Similar results are obtained through the use of soluble fluoborates, fluorides and bifiuorides. If hydrofluoric acid is used for this purpose it may also function to replace some of the acidifying agent such as the sodium bisulfate.
A blackening bath prepared in this manner is preferably heated to a temperature of between about 120 F. and 180 F. and most preferably between 150 F. and 160 F. for use, although it has been found effective in accomplishing the desired result at temperatures as low as about 50 F. and as high as its boiling temperature which is somewhat in excess of 212 F. Low temperatures require longer immersion periods while high temperatures result in deposition too rapidly and quite unevenly.
The aluminum pieces are immersed in the blackening composition for a period of from 1 to minutes depending upon the specific acidity of the solution and its temperature. Generally an immersion time of from 10 to 15 minutes is sufficient to form a dark black deposit which is smooth and even and which is firmly anchored to the aluminum surface. The aluminum is removed from the composition and washed or rinsed.
In cases where it is desired to further treat the aluminum to provide it with an oxidation-resisting, corrosionresistant coating, the blackened aluminum pieces are immersed in any conventional wax, oil or resin composition to deposit over the blackened surface a protective coating or shield. This is not practical with untreated aluminum since the surface has no afiinity for an oil, wax or resin coating and attempts to apply and retain such coatings thereto are unsuccessful. However the present blackened deposits on aluminum are found to provide a use according to the present invention.
perfect receptive surface for such protective coatings and appear to become integrated therewith to form a solid bond.
As protective coatings it is preferred to use thin solutions of oils and waxes which penetrate the blackened deposit on the aluminum and displace any water remaining therein as a residue of the aqueous blackening composition. When the pieces are withdrawn from the protective coating solutions the coatings dry quite rapidly in the form of very thin protective films or shields.
The phrase blackening composition as used herein and in the appended claims is intended to include compositions useful for applying jet black or off-black coatings including those in which the deposit is rather light or thin and which appear to have a gray color due partly to the show-through of the underlying aluminum.
While the compositions of the present invention have been discussed primarily in connection with their use in the blackening of aluminum and aluminum alloy metals, it should be understood that the present compositions are also useful for the blackening of other metals such as iron, stainless steel, brass, copper, Zinc, titanium, magnesium and the like. The present compositions are particularly adapted for the coloration of aluminum in view of the many problems encountered in connection with the coloration of aluminum and the provision of aluminum with a coating receptive to protective outer coatings of oil or wax.
Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.
We claim:
1. The method of blackening aluminum which c0m prises the steps of preparing a blackening com-position by dissolving in water from about 1 ounce to about 3 pounds per gallon of a mixture of compounds which are reactive with aluminum to render it receptive to the deposit of blackening compounds com-prising. up to by weight of a water-ionizable chloride and from 3% to 40% by weight of water-soluble salt of a metal falling below aluminum in the electromotive series, and a mixture of blackening compounds comprising from 0.5% to 20% by weight of water-soluble sulfur-bearing compound capable of forming a black metal-sulfur reaction product upon reaction with the said metal falling below aluminum in the electromotive series and from 2% to 25% by weight of water-soluble molybdate, maintaining the pH of the solution below about 6.5, maintaining the temperature of the solution within the range of from about 50 F. to about 212 F., immersing the aluminum into the blackening composition for a period of from 1 to 30 minutes, and removing the blackened aluminum.
2. The method according to claim 1 in which the temperature of the solution is maintained within the range of from about F. to about 180 F.
3. The method according to claim 1 in which the water-ionizable chloride is selected from the group consisting of alkali metal chlorides, ammonium chloride and hydrogen chloride.
4. The method according to claim 1 in which the sulfur-bearing compound is selected from the group consisting of a sulfide, thiosulfate, thiocyanate, thiourea, 2-mercaptobenzothiazole, benzothiazyl disulfi-de and Z-mercaptoimidazoline.
5. A blackening composition useful for the blackening of aluminum surfaces when dissolved in an aqueous solution in an amount ranging from about 1 ounce to about 3 pounds per gallon, said composition comprising a mixture of compounds which are reactive with aluminum to render it receptive to the deposit of blackening compounds and which comprise up to about 80% by weight of a water ionizable chloride and from 3% to 40% by weight of water-soluble salt of a metal falling below aluminum in the electromotive series, and a mixture of blackening compounds comprising from 0.5% to 20% by weight of water-soluble sulfur-bearing compound capable of forming a black metal-sulfur reaction product upon reaction with the said metal falling below aluminum in the electromotive series and from 2% to 25% by weight of watersoluble moly bdate.
6. A blackening composition according to claim 1 in which the watenionizable chloride is selected from the group consisting of alkali metal chlorides, ammonium chloride and hydrogen chloride.
7. A blackening composition according to claim 1 in which the sulfur-bearing compound is selected from the group consisting of a sulfide, thiosulfate, thiocyanate, thiourea, Z-mercaptobenzothiazole, benzothiazyl disulfide and Z-mercaptoimidazoline.
References Cited by the Examiner UNITED STATES PATENTS Vande Bunte 252-79.2 Singler 1061 XR Jendzynski 1061 Mason 1061 XR Baig et al 106-l XR Bellinger 25279.3 XR
ALEXANDER H. BRODMERKEL, Primary Examiner. J. B. EVANS, Assistant Examiner.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,314 ,811 April 18, 1967 Abraham J Mitchell et a1 It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 4, lines 0,43,46,74 and 75, before "water-soluble,
each occurrence insert a column 5 line 3 before "water" insert a lines 5 and 9 for the claim reference numeral "1", each occurrence read 5 Signed and sealed this 2nd day of January 1968 (SEAL) Attest:
EDWARD J. BRENNEF Commissioner of Patents Edward M. Fletcher, J r.
Attesting Officer
Claims (2)
1. THE METHOD OF BLACKENING ALUMINUM WHICH COMPRISES THE STEPS OF PREPARING A BLACKENING COMPOSITION BY DISSOLVING IN WATER FROM ABOUT 1 OUNCE TO ABOUT 3 POUNDS PER GALLON OF A MIXTURE OF COMPOUNDS WHICH ARE REACTIVE WITH ALUMINUM TO RENDER IT RECEPTIVE TO THE DEPOSIT OF BLACKENING COMPOUNDS COMPRISING UP TO 80% BY WEIGHT OF A WATER-IONIZABLE CHLORIDE AND FROM 3% TO 40% BY WEIGHT OF WATER-SOLUBLE SALT OF A METAL FALLING BELOW ALUMINUM IN THE ELECTROMOTIVE SERIES, AND A MIXTURE OF BLACKENING COMPOUNDS COMPRISING FROM 0.5% TO 20% BY WEIGHT OF WATER-SOLUBLE SULFUR-BEARING COMPOUND CAPABLE OF FORMING A BLACK METAL-SULFUR REACTION PRODUCT UPON REACTION WITH THE SAID METAL FALLING BELOW ALUMINUM IN THE ELECTROMOTIVE SERIES AND FROM 2% TO 25% BY WEIGHT OF WATER-SOLUBLE MOLYBDATE, MAINTAINING THE PH OF THE SOLUTION BELOW ABOUT 6.5, MAINTAINING THE TEMPERATURE OF THE SOLUTION WITHIN THE RANGE OF FROM ABOUT 50*F. TO ABOUT 212*F., IMMERSING THE ALUMINUM INTO THE BLACKENING COMPOSITION FOR A PERIOD OF FROM 1 TO 30 MINUTES, AND REMOVING THE BLACKENED ALUMINUM.
5. A BLACKENING COMPOSITION USEFUL FOR THE BLACKENING OF ALUMINUM SURFACES WHEN DISSOLVED IN AN AQUEOUS SOLUTION IN AN AMOUNT RANGING FROM ABOUT 1 OUNCE TO ABOUT 3 POUNDS PER GALLON, SAID COMPOSITION COMPRISING A MIXTURE OF COMPOUNDS WHICH ARE REACTIVE WITH ALUMINUM TO RENDER IT RECEPTIVE TO THE DEPOSIT OF BLACKENING COMPOUNDS AND WHICH COMPRISE UP TO ABOUT 80% BY WEIGHT OF A WATER IONIZABLE CHLORIDE AND FROM 3% TO 40% BY WEIGHT OF WATER-SOLUBLE SALT OF A METAL FALLING BELOW ALUMINUM IN THE ELECTROMOTIVE SERIES, AND A MIXTURE OF BLACKENING COMPOUNDS COMPRISING FROM 0.5% TO 20% BY WEIGHT OF WATER-SOLUBLE SULFUR-BEARING COMPOUND CAPABLE OF FORMING A BLACK METAL-SULFUR REACTION PRODUCT UPON REACTION WITH THE SAID METAL FALLING BELOW ALUMINUM IN THE ELECTROMOTIVE SERIES AND FROM 2% TO 25% BY WEIGHT OF WATERSOLUBLE MOLYBDATE.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US335393A US3314811A (en) | 1964-01-02 | 1964-01-02 | Metal treating compositions and processes |
| GB51086/64A GB1040006A (en) | 1964-01-02 | 1964-12-15 | Metal treating compositions and processes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US335393A US3314811A (en) | 1964-01-02 | 1964-01-02 | Metal treating compositions and processes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3314811A true US3314811A (en) | 1967-04-18 |
Family
ID=23311583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US335393A Expired - Lifetime US3314811A (en) | 1964-01-02 | 1964-01-02 | Metal treating compositions and processes |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3314811A (en) |
| GB (1) | GB1040006A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3391012A (en) * | 1967-01-31 | 1968-07-02 | Mitchell Bradford Chemical Co | Metal treating compositions and processes |
| US4061830A (en) * | 1975-12-23 | 1977-12-06 | Ppg Industries, Inc. | Selective solar energy receiver and method for its production |
| US4138526A (en) * | 1975-12-22 | 1979-02-06 | Thor Borresen | Process for producing good adherence between a metal and polysulphide material and articles produced thereby |
| FR2424333A1 (en) * | 1978-04-27 | 1979-11-23 | Hull & Co R O | TRIVALENT CHROME COATING SOLUTIONS FOR ZINC SURFACE COATING |
| FR2504156A1 (en) * | 1981-04-16 | 1982-10-22 | Hooker Chemicals Plastics Corp | PASSIVATION PRODUCT SOLUTION HAVING CHROMIC ASPECT AND METHOD OF USE |
| US4401509A (en) * | 1982-09-07 | 1983-08-30 | Fmc Corporation | Composition and process for printed circuit etching using a sulfuric acid solution containing hydrogen peroxide |
| WO2004108407A1 (en) * | 2003-06-05 | 2004-12-16 | Metal Coatings International Inc. | Compositions and methods for darkening and imparting corrosion-resistant properties to zinc or other active metals |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2139538A (en) * | 1983-05-07 | 1984-11-14 | Bl Tech Ltd | Structures fabricated from aluminium components |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2441300A (en) * | 1944-08-21 | 1948-05-11 | Packard Motor Car Co | Ink for etching metal |
| US2679475A (en) * | 1952-01-21 | 1954-05-25 | Joseph C Singler | Metal blackening composition and method |
| US2876116A (en) * | 1955-12-29 | 1959-03-03 | Gen Motors Corp | Chemical plating bath and process |
| US2933422A (en) * | 1957-05-31 | 1960-04-19 | Walter A Mason | Product and method for coating metals with copper-tellurium compound |
| US3127279A (en) * | 1964-03-31 | Aqueous black coating composition con- | ||
| US3171766A (en) * | 1962-10-04 | 1965-03-02 | Conversion Chem Corp | Bright polishing of cadmium and zinc |
-
1964
- 1964-01-02 US US335393A patent/US3314811A/en not_active Expired - Lifetime
- 1964-12-15 GB GB51086/64A patent/GB1040006A/en not_active Expired
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3127279A (en) * | 1964-03-31 | Aqueous black coating composition con- | ||
| US2441300A (en) * | 1944-08-21 | 1948-05-11 | Packard Motor Car Co | Ink for etching metal |
| US2679475A (en) * | 1952-01-21 | 1954-05-25 | Joseph C Singler | Metal blackening composition and method |
| US2876116A (en) * | 1955-12-29 | 1959-03-03 | Gen Motors Corp | Chemical plating bath and process |
| US2933422A (en) * | 1957-05-31 | 1960-04-19 | Walter A Mason | Product and method for coating metals with copper-tellurium compound |
| US3171766A (en) * | 1962-10-04 | 1965-03-02 | Conversion Chem Corp | Bright polishing of cadmium and zinc |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3391012A (en) * | 1967-01-31 | 1968-07-02 | Mitchell Bradford Chemical Co | Metal treating compositions and processes |
| US4138526A (en) * | 1975-12-22 | 1979-02-06 | Thor Borresen | Process for producing good adherence between a metal and polysulphide material and articles produced thereby |
| US4061830A (en) * | 1975-12-23 | 1977-12-06 | Ppg Industries, Inc. | Selective solar energy receiver and method for its production |
| FR2424333A1 (en) * | 1978-04-27 | 1979-11-23 | Hull & Co R O | TRIVALENT CHROME COATING SOLUTIONS FOR ZINC SURFACE COATING |
| FR2504156A1 (en) * | 1981-04-16 | 1982-10-22 | Hooker Chemicals Plastics Corp | PASSIVATION PRODUCT SOLUTION HAVING CHROMIC ASPECT AND METHOD OF USE |
| US4401509A (en) * | 1982-09-07 | 1983-08-30 | Fmc Corporation | Composition and process for printed circuit etching using a sulfuric acid solution containing hydrogen peroxide |
| WO2004108407A1 (en) * | 2003-06-05 | 2004-12-16 | Metal Coatings International Inc. | Compositions and methods for darkening and imparting corrosion-resistant properties to zinc or other active metals |
| US20060213389A1 (en) * | 2003-06-05 | 2006-09-28 | Pearce Michelle R | Compositions and methods for darkening and imparting corrosion-resistant properties to zinc or other active metals |
| EA008802B1 (en) * | 2003-06-05 | 2007-08-31 | Метал Коутингс Интернэшнл Инк. | Compositions and methods for darkening and imparting corrosion-resistant properties to zink or other active metals |
| US7641743B2 (en) * | 2003-06-05 | 2010-01-05 | Metal Coatings International Inc. | Compositions and methods for darkening and imparting corrosion-resistant properties to zinc or other active metals |
| US20100297354A1 (en) * | 2003-06-05 | 2010-11-25 | Metal Coatings International Inc. | Compositions and methods for darkening and imparting corrosion-resistant properties to zinc or other active metals |
Also Published As
| Publication number | Publication date |
|---|---|
| GB1040006A (en) | 1966-08-24 |
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Legal Events
| Date | Code | Title | Description |
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| AS | Assignment |
Owner name: MITCHELL-BRADFORD INTERNATIONAL CORP. A CT CORPOR Free format text: SECURITY INTEREST;ASSIGNOR:HUBBARD-HALL, INC., A CT CORPORATION;REEL/FRAME:005810/0251 Effective date: 19910517 |