US3833485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electroplating chromium and chromium alloys
Assignee: Individual
•
Filing: 1972-02-22
•
Granted: 1974-09-03
•
Expires: 1992-02-22
Abstract
Abstract An improved process for electroplating chromium and chromium alloys from a substantially aqueous electrolyte containing trivalent chromium ions as the source of chromium and containing oxyanions (preferably sulphate ions) as the major anion component. The improvement comprises incorporating into said electrolyte chlorine ions in an amount of at least 0.1 gram ions per litre or bromine ions in an amount of at least 0.05 grams ions per litre, and a nitrogen compound selected from the group consisting of ammonium compounds, hydroxylamine, hydrazine, urea, aliphatic amines and hetercyclic amines; and utilizing a carbon anode and electroplating chromium from said electrolyte with said carbon anode immersed in said electrolyte. The chlorine ion is preferred and the use of ammonium compounds is preferred.
Inventors
- 👤 J Crowther
- 👤 R Ashpole
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:17
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/04; C25D3/06; C25D3/10; C25D3/38; C25D3/56
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
23 words
A process according to claim 1 wherein said electrolyte contains chlorine ions in a concentration of 1.0 to 1.5 gram ions per litre.
Claim 2
Dependent Claim
12 words
A process according to claim 2 wherein said oxyanions are sulphate ions.
Claim 3
Dependent Claim
26 words
A process according to claim 3 wherein the concentration of said nitrogen-containing compound in said electrolye is from one-half to twice that of said chlorine ions.
Claim 4
Dependent Claim
14 words
A process according to claim 4 wherein said nitrogen-containing compound is an ammonium compound.
Claim 5
Dependent Claim
23 words
A process according to claim 1 wherein said electrolyte contains bromine ions in a concentration of 0.1 to 0.2 gram ions per litre.
Claim 6
Dependent Claim
12 words
A process according to claim 6 wherein said oxyanions are sulphate ions.
Claim 7
Dependent Claim
26 words
A process according to claim 7 wherein the concentration of said nitrogen-containing compound in said electrolyte is from one-half to twice that of said bromine ions.
Claim 8
Dependent Claim
14 words
A process according to claim 8 wherein said nitrogen-containing compound is an ammonium compound.
Claim 9
Dependent Claim
26 words
A process as claimed in claim 1 wherein bromine ions are present in said electrolyte in a concentration of at least 0.05 gram ions per litre.
Claim 10
Dependent Claim
27 words
A process as claimed in claim 10 wherein bromine ions are present in said electrolyte in a concentration of from 0.05 to 0.1 gram ions per litre.
Claim 11
Dependent Claim
25 words
A process as claimed in claim 1 wherein the concentration of nitrogen-containing compound is less than 10 per cent by weight in the water present.
Claim 12
Dependent Claim
14 words
A process according to claim 1 wherein said nitrogen-containing compound is an ammonium compound.
Claim 13
Dependent Claim
12 words
A process according to claim 1 wherein said oxyanions are sulphate ions.
Claim 14
Dependent Claim
26 words
A process according to claim 1 wherein the concentration of said nitrogen-containing compounds in said electrolyte is from one-half to twice that of said halogen ion.
Claim 15
Dependent Claim
22 words
A process according to claim 1 wherein the concentration of said nitrogen-containing compound in said electrolyte is from 3 to 5 molar.
Claim 16
Dependent Claim
152 words
In the process of electroplating chromium and chromium alloys on a cathode from a substantially aqueous acidic electrolyte containing trivalent chromium ions as the source of chromium which is electroplated and sulphate ions as the major anion component, the improvement which consists in: (A) incorporating into said electrolyte at least 0.1 gram ions per litre of halogen ion as chlorine ion or at least 0.05 gram ions per litre of hAlogen ion as bromine ion and an ammonium compound; the concentration of said ammonium compound being at least half that of said halogen ion and not greater than 5 molar and the concentration of said halogen ion being not greater than twice that of said ammonium compound, the anionic species of said electrolyte with the lowest electrical discharge potential being said halogen ions; (B) utilizing a carbon anode and electroplating chromium from said electrolyte with said carbon anode immersed in said electrolyte.
Claim 17
Dependent Claim
22 words
A process according to claim 17 wherein said halogen ion is chlorine ion and the pH of said electrolyte is below 2.3.
Claim 18
Dependent Claim
39 words
A process according to claim 18 wherein said chlorine ion is present in a concentration of from 1.0 to 1.5 gram ions per litre and said ammonium compound is present in a concentration of from 3 to 5 molar.
Claim 19
Dependent Claim
22 words
A process according to claim 17 wherein said halogen ion is bromine ion and the pH of said electrolyte is below 2.6.
Claim 20
Dependent Claim
39 words
A process according to claim 20 wherein said bromine ion is present in a concentration of from 0.1 to 0.2 gram ions per litre and said ammonium compound is present in a concentration of from 3 to 5 molar.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |