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US4093521A
Expired / Lapsed
US
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Chromium electroplating
Assignee: Individual
•
Filing: 1977-06-28
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Granted: 1978-06-06
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Expires: 1997-06-28
Abstract
Abstract Improved trivalent chromium electroplating baths containing from about 30 to about 150 parts per million of iron or nickel content, or from about 30 to about 150 parts per million of iron plus nickel with the nickel in an amount up to about 100 parts per million.
Inventors
- 👤 Stanley Renton
- 👤 John Cooper Crowther
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:13
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/04; C25D3/06; C25D3/56
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
95 words
In a trivalent chromium electroplating bath of the type which consists essentially of an acidic aqueous solution of trivalent chromium, a carboxylate selected from formate, acetate and mixtures thereof, a bromide and ammonium the improvement which consists in maintaining in said bath an amount of metal ion selected from (i) iron or nickel in the amount of between 30 and 150 parts per million of the solution by weight, or (ii) iron plus nickel in the amount of between 30 and 150 ppm with the nickel being in an amount up to about 100 ppm.
Claim 2
Dependent Claim
95 words
In a trivalent chromium electroplating bath of the type which consists essentially of an acidic aqueous solution of trivalent chromium, a carboxylate selected from formate, acetate and mixtures thereof, a bromide and ammonium the improvement which consists in maintaining in said bath an amount of metal ion selected from (i) iron or nickel in the amount of between 30 and 150 parts per million of the solution by weight, or (ii) iron plus nickel in the amount of between 30 and 150 ppm with the nickel being in an amount up to about 100 ppm.
Claim 3
Dependent Claim
104 words
The bath of claim 1 consisting essentially of: a. from 0.1 to 1.2 molar trivalent chromium; b. from 0.05 to 0.5 molar bromide; c. from 0.5 to 3 moles of a carboxylate selected from formate and mixtures thereof with acetate; d. from 0.2 molar to saturation of ammonium ion; e. from 0.1 molar to saturation of borate; f. at least one ion selected from chloride and sulphate in a concentration of from 1 molar to saturation; g. said metal ion; h. from 0.5 molar to saturation of ion selected from sodium and potassium; i. said bath having a pH of between 1 and 4.
Claim 4
Dependent Claim
15 words
The bath of claim 2 containing from 30 to 150 parts per million of iron.
Claim 5
Dependent Claim
15 words
The bath of claim 2 containing from 30 to 150 parts per million of nickel.
Claim 6
Dependent Claim
30 words
The bath of claim 2 containing from 30 to 150 parts per million of iron plus nickel with nickel being in an amount up to about 100 parts per million.
Claim 7
Dependent Claim
18 words
The bath of claim 2 containing from about 40 to 100 parts per million of iron plus nickel.
Claim 8
Dependent Claim
16 words
The bath of claim 2 containing from about 40 to 100 parts per million of iron.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |