US1730349A - Electrodeposition of chromium - Google Patents
Electrodeposition of chromium Download PDFInfo
- Publication number
- US1730349A US1730349A US200765A US20076527A US1730349A US 1730349 A US1730349 A US 1730349A US 200765 A US200765 A US 200765A US 20076527 A US20076527 A US 20076527A US 1730349 A US1730349 A US 1730349A
- Authority
- US
- United States
- Prior art keywords
- chromium
- acid
- electrodeposition
- bath
- deposition
- 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
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical group [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 title description 10
- 229910052804 chromium Inorganic materials 0.000 title description 10
- 239000011651 chromium Substances 0.000 title description 10
- 238000004070 electrodeposition Methods 0.000 title description 3
- 239000002253 acid Substances 0.000 description 13
- 150000007513 acids Chemical class 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 5
- 238000000151 deposition Methods 0.000 description 5
- 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 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 230000008021 deposition Effects 0.000 description 4
- 238000007792 addition Methods 0.000 description 3
- 150000001450 anions Chemical class 0.000 description 3
- 238000010494 dissociation reaction Methods 0.000 description 3
- 230000005593 dissociations Effects 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- -1 hydrogen ions Chemical class 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 235000010755 mineral Nutrition 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-N acetic acid Substances CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 229940055042 chromic sulfate Drugs 0.000 description 1
- 229910000151 chromium(III) phosphate Inorganic materials 0.000 description 1
- GRWVQDDAKZFPFI-UHFFFAOYSA-H chromium(III) sulfate Chemical compound [Cr+3].[Cr+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O GRWVQDDAKZFPFI-UHFFFAOYSA-H 0.000 description 1
- 229910000356 chromium(III) sulfate Inorganic materials 0.000 description 1
- 239000011696 chromium(III) sulphate Substances 0.000 description 1
- 235000015217 chromium(III) sulphate Nutrition 0.000 description 1
- IKZBVTPSNGOVRJ-UHFFFAOYSA-K chromium(iii) phosphate Chemical compound [Cr+3].[O-]P([O-])([O-])=O IKZBVTPSNGOVRJ-UHFFFAOYSA-K 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 150000002739 metals Chemical group 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- ZNCPFRVNHGOPAG-UHFFFAOYSA-L sodium oxalate Chemical compound [Na+].[Na+].[O-]C(=O)C([O-])=O ZNCPFRVNHGOPAG-UHFFFAOYSA-L 0.000 description 1
- 229940039790 sodium oxalate Drugs 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical group 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/04—Electroplating: Baths therefor from solutions of chromium
Definitions
- Patented Oct. 8 1929 UNITED STATES PATENT OFFICE BUDOLF AUEBBLCH OF PBDBSTDEUBEN, NEAR LEIPZIG, GERMANY, ASSIGNOR, BY IESNE ASSIGNHENTS, TO QHROHEPLATE, INC., 01 UNION CITY, NEW JERSEY, A
- My invention refers to the electrolytic deposition of metals and more especially chromium. Its particular object is to improve the process of electro-deposition of chromium hitherto in use.
- the free acids, more especially strong mineral acids present in the electrolyte create considerable difliculties inasmuch as the presence of great quantities of such acids renders high current densities necessary for the deposition of chromium, and under certain conditions will even altogether prevent such depositions.
- the mineral acids, and more especially sulfuric and hydrochloric acid can be present in the electrolyte from two causes, viz: as impurities of the commercial chemicals used (chromic acid for instance containing sulfuric acid) or as the products of decomposition of sulfates, chlorides, or the like during the electrolytic process.
- small quantities of free acid exert a favorable action on the electro-deposition of the metal, for instance by keeping oxides dissolved.
- the electrolytic bath which consists of a watery solution of chromic acid which may also contain an addition of chromic sulfate, a
- the electrolytical process was carried through at a temperature of the bath of 20 (3., at a pressure of 3.5 volts and a current density of 1 ampere per square decimetre or above, With a bath having the above composition a perfeet chromium deposit having the properties above described was obtained within 1 to 2 hours.
- I claim The process of electro-depositing chromium which consists in adding to a solution of chromic acid containing a free, highly dissociated acid asaltof an acid with a dissociation constant less than the dissociation constant of hosphoric acid with relation to the first hy rogen ion liberated therefrom, to decrease the concentration of the hydrogen ions.
Description
Patented Oct. 8 1929 UNITED STATES PATENT OFFICE BUDOLF AUEBBLCH OF PBDBSTDEUBEN, NEAR LEIPZIG, GERMANY, ASSIGNOR, BY IESNE ASSIGNHENTS, TO QHROHEPLATE, INC., 01 UNION CITY, NEW JERSEY, A
CORPOQATION 01' NEW JERSEY ELECTBODEPOSITION OF CHBQKIUM No Drawing. Application filed June 22, 1927, Serial 80.200365, and in Germany June 80, 1926.
My invention refers to the electrolytic deposition of metals and more especially chromium. Its particular object is to improve the process of electro-deposition of chromium hitherto in use.
In this process the free acids, more especially strong mineral acids present in the electrolyte create considerable difliculties inasmuch as the presence of great quantities of such acids renders high current densities necessary for the deposition of chromium, and under certain conditions will even altogether prevent such depositions. The mineral acids, and more especially sulfuric and hydrochloric acid, can be present in the electrolyte from two causes, viz: as impurities of the commercial chemicals used (chromic acid for instance containing sulfuric acid) or as the products of decomposition of sulfates, chlorides, or the like during the electrolytic process. On the other hand small quantities of free acid exert a favorable action on the electro-deposition of the metal, for instance by keeping oxides dissolved.
According to the present invention now I add to the electrolytic bath, which consists of a watery solution of chromic acid which may also contain an addition of chromic sulfate, a
salt or salts of chromium or of an alkali metal, the anions of which belong to weak acids having a coeflicient of dissociation at least as low as that of phosphoric acid. The weak anion in this salt is thus replaced by the strong acids, for instance as follows:
Chromium acetate-Fsulfuric acidchromium sulfate-l-acetic acid.
Sodium oxalate+sulfuric acidsodium sulfate-toxalic acid.
While during these reactions as shown above, the concentration ofthe free acid is not changed, the exchange of anions causes the concentration of hydrogen ions to be lowered down to a favorable value Without the necessary acid reaction of the baths disappearing. The additions ab'oge described have a certain bufier action on the-electrolytic bath as a whole, inasmuch as they remain constantly effective during the "electrolytical process and maintain constant the. suitable jmoh'centration of hydrogen ions. By neutralization with alkali such effect cannot be obtained, as in this case the bath would have to be constantly watched and its composition adgisted during the operation.
y making the additions above described I provide that the deposition of chromium takes place also at low current densities, down to 1 ampere per square decimetre. In this manner I succeed in obtaining from such bath high-grade chromium deposits which are distinguished by their brilliancy, homogeneity, and perfect adhering capacity, all these propertiesbeing-obtainable only when operating atlow current densities. E wampZe.To a watery chromic acid solution containing 300 grams chromic acid per liter were added 5 grams chromium phosphate. The anodes used with this electrolyte were lead anodes spaced apart 15 cms. The electrolytical process was carried through at a temperature of the bath of 20 (3., at a pressure of 3.5 volts and a current density of 1 ampere per square decimetre or above, With a bath having the above composition a perfeet chromium deposit having the properties above described was obtained within 1 to 2 hours.
Various changes may be made in the details disclosed in the foregoing specification without departing from the invention or sacrificing the advantages thereof.
I claim The process of electro-depositing chromium, which consists in adding to a solution of chromic acid containing a free, highly dissociated acid asaltof an acid with a dissociation constant less than the dissociation constant of hosphoric acid with relation to the first hy rogen ion liberated therefrom, to decrease the concentration of the hydrogen ions.
In testimony whereof I afiix my signature.
RUDOLF AUERBACH.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE1730349X | 1926-06-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US1730349A true US1730349A (en) | 1929-10-08 |
Family
ID=7740969
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US200765A Expired - Lifetime US1730349A (en) | 1926-06-30 | 1927-06-22 | Electrodeposition of chromium |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US1730349A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2721835A (en) * | 1951-07-07 | 1955-10-25 | Shwayder Bros Inc | Surface treatment of aluminum articles |
| US4406756A (en) * | 1981-07-13 | 1983-09-27 | Canadian Corporate Management Company Limited | Hard chromium plating from hexavalent plating bath |
| DE19532831A1 (en) * | 1995-08-28 | 1997-03-06 | Atotech Deutschland Gmbh | Aq. bath having high corrosion resistance |
-
1927
- 1927-06-22 US US200765A patent/US1730349A/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2721835A (en) * | 1951-07-07 | 1955-10-25 | Shwayder Bros Inc | Surface treatment of aluminum articles |
| US4406756A (en) * | 1981-07-13 | 1983-09-27 | Canadian Corporate Management Company Limited | Hard chromium plating from hexavalent plating bath |
| DE19532831A1 (en) * | 1995-08-28 | 1997-03-06 | Atotech Deutschland Gmbh | Aq. bath having high corrosion resistance |
| DE19532831C2 (en) * | 1995-08-28 | 1998-07-09 | Atotech Deutschland Gmbh | Process for the electrolytic deposition of chromium / phosphorus alloys |
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