US2996353A - Sodium fluochromate and the process for preparing the same - Google Patents
Sodium fluochromate and the process for preparing the same Download PDFInfo
- Publication number
- US2996353A US2996353A US803350A US80335059A US2996353A US 2996353 A US2996353 A US 2996353A US 803350 A US803350 A US 803350A US 80335059 A US80335059 A US 80335059A US 2996353 A US2996353 A US 2996353A
- Authority
- US
- United States
- Prior art keywords
- sodium
- fluochromate
- preparing
- chromium
- same
- 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
- 239000011734 sodium Substances 0.000 title description 18
- 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 title description 14
- 229910052708 sodium Inorganic materials 0.000 title description 14
- 238000004519 manufacturing process Methods 0.000 title description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical class [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 12
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 9
- 239000011651 chromium Substances 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 229910052804 chromium Inorganic materials 0.000 description 6
- 235000013024 sodium fluoride Nutrition 0.000 description 6
- 239000011775 sodium fluoride Substances 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 4
- 150000001844 chromium Chemical class 0.000 description 4
- 238000007747 plating Methods 0.000 description 4
- 150000001845 chromium compounds Chemical class 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- IIACRCGMVDHOTQ-UHFFFAOYSA-M sulfamate Chemical compound NS([O-])(=O)=O IIACRCGMVDHOTQ-UHFFFAOYSA-M 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- LNOPIUAQISRISI-UHFFFAOYSA-N n'-hydroxy-2-propan-2-ylsulfonylethanimidamide Chemical compound CC(C)S(=O)(=O)CC(N)=NO LNOPIUAQISRISI-UHFFFAOYSA-N 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- KWSLGOVYXMQPPX-UHFFFAOYSA-N 5-[3-(trifluoromethyl)phenyl]-2h-tetrazole Chemical compound FC(F)(F)C1=CC=CC(C2=NNN=N2)=C1 KWSLGOVYXMQPPX-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- 241001416092 Buteo buteo Species 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 241001274216 Naso Species 0.000 description 1
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 1
- NLZQVLUEFDOPMA-UHFFFAOYSA-N [Cl].[Ni] Chemical compound [Cl].[Ni] NLZQVLUEFDOPMA-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- 239000010425 asbestos Substances 0.000 description 1
- QDWJUBJKEHXSMT-UHFFFAOYSA-N boranylidynenickel Chemical compound [Ni]#B QDWJUBJKEHXSMT-UHFFFAOYSA-N 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- UZEDIBTVIIJELN-UHFFFAOYSA-N chromium(2+) Chemical compound [Cr+2] UZEDIBTVIIJELN-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 1
- 239000011976 maleic acid Substances 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 230000001603 reducing effect Effects 0.000 description 1
- 229910052895 riebeckite Inorganic materials 0.000 description 1
- 229910001379 sodium hypophosphite Inorganic materials 0.000 description 1
- 239000012258 stirred mixture Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 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
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/31—Coating with metals
- C23C18/32—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron
- C23C18/34—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents
- C23C18/36—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents using hypophosphites
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G37/00—Compounds of chromium
- C01G37/006—Compounds containing chromium, with or without oxygen or hydrogen, and containing two or more other elements
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
Definitions
- This invention relates to a new chromium compound, and is more particularly concerned with an air-stable and soluble divalent chromium salt useful in metal deposition.
- Certain metal plating operations require the use of aqueous solutions containing chromous ions. Replacement of the divalent chromium as it is used up is necessary in order to maintain the activity of a plating bath. For this and other purposes it is desirable to have a stable chromium salt which can be added directly to aqueous baths to form chromous ions in solution.
- a novel chromium compound sodium fiuochromate (II), Na CrF is formed by reacting sodium fluoride with a soluble divalent chromium compound in aqueous solution.
- Sodium fluochromate (II) crystallizes in the form of needles which mat together much like asbestos and are pale to strong clear blue depending on the particle size. It is not strongly ferromagnetic.
- chromate (II) shows strong reducing properties due to the available chromous ion as, for example, in reduction of Ag Cu++, Ni and Sb+++ to metals.
- Example '1 The procedure is carried out under nitrogen, and deoxygenated water is used, to avoid oxidizing Cr to Cr+++ or higher.
- Chromous sulfamate is prepared by reacting 20.0 parts of pure chromium powder with 40.0 parts of sulfamic acid in 200 parts of water. The reaction temperature is slowly raised from room temperature to 90 C. After an induction period the chromium reacts until the sulfarnic acid is substantially used up according to the reaction:
- the resulting solution which is a strong bright blue, is filtered to remove unreacted chromium metal.
- An extra 200 parts of water is used for rinsing the unreacted chromium and combined with the initial filtrate.
- the sodium fluo-rchromate (II) is readily crystallized in the form of blue needles about 0.4 mm. in length which mat together.
- the new salt is useful for forming chromium (lI) complexes in baths used in corrosionprotective coating or electrolytic plating processes. Such use is illustrated by the following example:
- a bright coating forms weighing 0.1 nig./cm.
- the time to destruction of the coating in this highly accelerated corrosion test was 305 minutes.
- the time to destruction for a similar Weight of nickel-boron coating, or nickel coating prepared by other methods is only about 15 minutes.
- the process for preparing sodium fluochromate (II) which comprises heating an aqueous solution of sodium fluoride and chromous sulfamate to about C., cooling the solution to precipitate sodium fluoehromate (II), and separating the precipitated sodium fluochromate (II) from the reaction mixture.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Inorganic Chemistry (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Electroplating And Plating Baths Therefor (AREA)
Description
United States Patent F 2,996,353 SODIUM FLUOCI-IROMATE AND THE PROCESS FOR PREPARING THE SAME Alden Johnson Deyrnp, West Goshen Township, Chester County, Pa., assignor to E. I. du Pont de Nemours and Company, Wilmington Del., a corporation of Delaware No Drawing. Filed Apr. 1, 1959, Ser. No. 803,350
3 Claims. (CI. 23-56) This invention relates to a new chromium compound, and is more particularly concerned with an air-stable and soluble divalent chromium salt useful in metal deposition.
Certain metal plating operations require the use of aqueous solutions containing chromous ions. Replacement of the divalent chromium as it is used up is necessary in order to maintain the activity of a plating bath. For this and other purposes it is desirable to have a stable chromium salt which can be added directly to aqueous baths to form chromous ions in solution.
It is an object of this invention to provide a new salt of divalent chromium. Another object is to provide such a salt which is stable in air and ionizes in aqueous solution to furnish chromous ions. A further object is to provide new plating baths and processes for plating metal using solutions of this divalent chromium salt. Other objects will become apparent from the specification and claims.
In accordance with this invention it has been found that a novel chromium compound, sodium fiuochromate (II), Na CrF is formed by reacting sodium fluoride with a soluble divalent chromium compound in aqueous solution. Sodium fluochromate (II) crystallizes in the form of needles which mat together much like asbestos and are pale to strong clear blue depending on the particle size. It is not strongly ferromagnetic.
An X-ray powder diflraction pattern of a sample 94-98% pure showed a characteristic pattern of lines with 4.86, 2.81, and 2.76 A. as the strongest lines. The complete pattern is described in the following table, where d is the spacing in Angstrom units and U1 is the relative intensity (S=strong; M=medium; F=faint; V=very faint).
d I/Io d I/Iu h I/Io 4.86 S V 1. V 4. V V l. M 3. M 1. M 2. M 1. M 2. M 1. M 2. M 1. M 2. M 1. M 2. F l. M 2. M 1. M
However, in hot deoxygenated water the compound does not dissolve, but solwly evolves hydrogen. It behaves in chemical reactions like a loose complex of Na Cr' and F". It reacts with strong acids to form solutions which exhibit the characteristic clear blue of 2,996,353 Patented Aug. 15, 19 61 ice these reactions, which are all quite rapid. Sodium fluo-.
chromate (II) shows strong reducing properties due to the available chromous ion as, for example, in reduction of Ag Cu++, Ni and Sb+++ to metals.
A convenient method for preparing sodium fluochromate (II) is illustrated by the following example, in which parts are by weight:
Example '1 The procedure is carried out under nitrogen, and deoxygenated water is used, to avoid oxidizing Cr to Cr+++ or higher. Chromous sulfamate is prepared by reacting 20.0 parts of pure chromium powder with 40.0 parts of sulfamic acid in 200 parts of water. The reaction temperature is slowly raised from room temperature to 90 C. After an induction period the chromium reacts until the sulfarnic acid is substantially used up according to the reaction:
The resulting solution, which is a strong bright blue, is filtered to remove unreacted chromium metal. An extra 200 parts of water is used for rinsing the unreacted chromium and combined with the initial filtrate.
The solution of chromous sulfamate is mixed with a suspension of 35.0 parts of sodium fluoride in 200 parts of water in a stirred flask. The stirred mixture is heated to about 80-l00 C. and then allowed to cool. Sodium fluochrom'ate (II) is formed according to the following reaction and precipitates:
Usually a dense precipitate forms first, followed by growth of a very bulky precipitate which again becomes more dense. The precipitate is filtered and washed, first with 50% methanol (in which NaSO NH and any excess NaF are appreciably soluble), and then with methanol. Air drying of the precipitate is satisfactory, but vaccum drying can be used. There is obtained 27.9 parts of Na OrF which corresponds to a yield of 77% on NaF, 78% on sulfamic acid and about on reacted chromium. Precipitation is incomplete at the stoichiometric ratio used in this example, but complete precipitation of Na CrF is apparently achieved in other cases by use of an excess of sodium fluoride.
Analysis Found Calculated for NarCrFr The sodium fluo-rchromate (II) is readily crystallized in the form of blue needles about 0.4 mm. in length which mat together. The new salt is useful for forming chromium (lI) complexes in baths used in corrosionprotective coating or electrolytic plating processes. Such use is illustrated by the following example:
Example 2 Molal Maleic acid 0.75 Ammonium hydr 5.5 Boric acid 1.5 Nickel chlor 0.037 Sodium hypophosphite 0.17 Sodium fluochromate (II) 0.052
A bright coating forms weighing 0.1 nig./cm. When tested for corrosion resistance in a humid atmosphere of sulfur dioxide at room temperature, the time to destruction of the coating in this highly accelerated corrosion test was 305 minutes. For comparison, the time to destruction for a similar Weight of nickel-boron coating, or nickel coating prepared by other methods, is only about 15 minutes.
The activity of the bath used in the above example is maintained by periodic addition of sodium fluochromate (II).
Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited by the specific illustrations except to the extent defined in the following claims.
Iclaim:
1. Sodium fluochromate (II).
2. The crystalline divalent chromium salt of sub stantially the formula, Na CrF characterized by high stability in air and appreciable solubility in Water.
3. The process for preparing sodium fluochromate (II) which comprises heating an aqueous solution of sodium fluoride and chromous sulfamate to about C., cooling the solution to precipitate sodium fluoehromate (II), and separating the precipitated sodium fluochromate (II) from the reaction mixture.
References Cited in the file of this patent UNITED STATES PATENTS Buzzard June 11, 1940 Halpert Apr. 21, 1959 OTHER REFERENCES
Claims (1)
- 2. THE CRYSTALLINE DIVALENT CHROMIUM SALT OF SUBSTANTIALLY THE FORMULA, NA2CRF4, CHARACTERIZED BY HIGH STABILITY IN AIR AND APPRECIABLE SOLUBILITY IN WATER.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US803350A US2996353A (en) | 1959-04-01 | 1959-04-01 | Sodium fluochromate and the process for preparing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US803350A US2996353A (en) | 1959-04-01 | 1959-04-01 | Sodium fluochromate and the process for preparing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2996353A true US2996353A (en) | 1961-08-15 |
Family
ID=25186311
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US803350A Expired - Lifetime US2996353A (en) | 1959-04-01 | 1959-04-01 | Sodium fluochromate and the process for preparing the same |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2996353A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3247028A (en) * | 1961-06-28 | 1966-04-19 | Bayer Ag | Processes for improving the corrosion resistance of ni-co-metal coatings containing boron |
| US4711680A (en) * | 1983-05-23 | 1987-12-08 | Rockwell International Corporation | Pure fluorine gas generator |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2203670A (en) * | 1937-06-29 | 1940-06-11 | Robert W Buzzard | Method of treating electrolytic coatings on magnesium and its alloys |
| US2883311A (en) * | 1956-10-01 | 1959-04-21 | Vertol Aircraft Corp | Method and composition for treating aluminum and aluminum alloys |
-
1959
- 1959-04-01 US US803350A patent/US2996353A/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2203670A (en) * | 1937-06-29 | 1940-06-11 | Robert W Buzzard | Method of treating electrolytic coatings on magnesium and its alloys |
| US2883311A (en) * | 1956-10-01 | 1959-04-21 | Vertol Aircraft Corp | Method and composition for treating aluminum and aluminum alloys |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3247028A (en) * | 1961-06-28 | 1966-04-19 | Bayer Ag | Processes for improving the corrosion resistance of ni-co-metal coatings containing boron |
| US4711680A (en) * | 1983-05-23 | 1987-12-08 | Rockwell International Corporation | Pure fluorine gas generator |
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