US4196063A
Expired / Lapsed
US
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Electrodeposition of black chromium
Assignee: International Lead Zinc Research Organization Inc
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Filing: 1979-04-19
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Granted: 1980-04-01
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Expires: 1999-04-19
Abstract
Abstract An electrolyte solution and the method of using same for electrodeposition of black chromium on a substrate, said solution comprising water, trivalent chromium ions, ions of a metal selected from the group consisting of iron and cobalt, a weak complexing agent for the trivalent chromium ions, and phosphate ions. The preferred complexing agents are hypophosphite or formate.
Inventors
- 👤 Clive Barnes
- 👤 John J. B. Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:57
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/04; C25D3/08; C25D3/06; F; F24; F24S; F24S70/00; F24S70/20; F24S70/25; Y; Y02; Y02E; Y02E10/00; Y02E10/40
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
82 words
An electrolyte solution for electrodeposition of black chromium on a substrate, said solution comprising water, trivalent chromium ions in a concentration of from about 0.01M to about 2.0M, from about 2 to about 25 g/l of ions of a metal selected from the group consisting of iron and cobalt, phosphate ions in a concentration of from 1 to about 5 g/l, and from about 0.1M to about 6M of a weak complexing agent selected from the group consisting of hypophosphite and formate.
Claim 2
Dependent Claim
82 words
An electrolyte solution for electrodeposition of black chromium on a substrate, said solution comprising water, trivalent chromium ions in a concentration of from about 0.01M to about 2.0M, from about 2 to about 25 g/l of ions of a metal selected from the group consisting of iron and cobalt, phosphate ions in a concentration of from 1 to about 5 g/l, and from about 0.1M to about 6M of a weak complexing agent selected from the group consisting of hypophosphite and formate.
Claim 3
Dependent Claim
14 words
An electrolyte solution according to claim 1 wherein the weak complexing agent is hypophosphite.
Claim 4
Dependent Claim
14 words
An electrolyte solution according to claim 1 wherein the weak complexing agent is formate.
Claim 5
Dependent Claim
14 words
An electrolyte solution according to claims 2 or 3 wherein the metal is iron.
Claim 6
Dependent Claim
14 words
An electrolyte solution according to claims 2 or 3 wherein the metal is cobalt.
Claim 7
Independent Claim
120 words
A method of electrodepositing a black chromium coating on a substrate which comprises immersing said substrate in an electrolyte solution comprising water, trivalent chromium ions in a concentration of from about 0.01M to about 2.0M, from about 2 to about 25 g/l of ions of a metal selected from the group consisting of iron and cobalt, phosphate ions in a concentration of from about 1 to about 5 g/l, and from about 0.1M to about 6M of a weak complexing agent selected from the group consisting of hypophosphite and formate and passing an electric current through said solution thereby to deposit on said substrate said trivalent chromium ions and said other co-depositable metal ions together as a black chromium coating.
Claim 8
Independent Claim
120 words
A method of electrodepositing a black chromium coating on a substrate which comprises immersing said substrate in an electrolyte solution comprising water, trivalent chromium ions in a concentration of from about 0.01M to about 2.0M, from about 2 to about 25 g/l of ions of a metal selected from the group consisting of iron and cobalt, phosphate ions in a concentration of from about 1 to about 5 g/l, and from about 0.1M to about 6M of a weak complexing agent selected from the group consisting of hypophosphite and formate and passing an electric current through said solution thereby to deposit on said substrate said trivalent chromium ions and said other co-depositable metal ions together as a black chromium coating.
Claim 9
Dependent Claim
13 words
A method according to claim 6 wherein the weak complexing agent is hypophosphite.
Claim 10
Dependent Claim
13 words
A method according to claim 6 wherein the weak complexing agent is formate.
Claim 11
Independent Claim
13 words
A method according to claims 7 or 8 wherein the metal is iron.
Claim 12
Independent Claim
13 words
A method according to claims 7 or 8 wherein the metal is cobalt.
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) | 1983-04-01 | 1983-10-01 | 1984-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-01 | 1987-10-01 | 1988-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-01 | 1991-10-01 | 1992-04-01 | $7700.00 | Window Closed / Lapsed |