US3920528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bright acid zinc plating method and electrolyte
Assignee: Bayer Pharma AG
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Filing: 1973-10-25
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Granted: 1975-11-18
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Expires: 1993-10-25
Abstract
Abstract Bright zinc electrodeposits are obtained at high current densities from aqueous, acid electrolytes containing zinc ions, inert alkali metal salts of strong mineral acids for improving conductivity, and a brightener which includes a small amount of an acid having a carboxyl group or a sulfo group attached directly or through a lower alkylene, vinyl, carbonyl, or phenylene group to the heterocyclic ring of pyridine, quinoline, isoquinoline, pyrrol, piperidine, pyrrolidine, or pyrrolidone. The electrolytes are free from significant amounts of complexing agents that would impede precipitation of the zinc ions at weakly alkaline pH so that the electrolytes do not present a waste disposal problem.
Inventors
- 👤 Gunter Voss
- 👤 Helga Hoffmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:46
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/22
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
44 words
IN AN ACID ZINC ELECTROPLATING ELECTROLYTE INCLUDING A SOURCE OF ZINC IONS, AN INERT SALT FOR IMPROVING THE CONDUCTIVITY OF THE ELECTROLYTE, AND A BRIGHTENER, THE IMPROVEMENT IN THE BRIGHTENER WHICH CONSISTS ESSENTIALLY OF AN EFFECTIVE AMOUNT OF A BRIGHTENING AGENT OF THE FORMULA
Claim 2
Dependent Claim
44 words
IN AN ACID ZINC ELECTROPLATING ELECTROLYTE INCLUDING A SOURCE OF ZINC IONS, AN INERT SALT FOR IMPROVING THE CONDUCTIVITY OF THE ELECTROLYTE, AND A BRIGHTENER, THE IMPROVEMENT IN THE BRIGHTENER WHICH CONSISTS ESSENTIALLY OF AN EFFECTIVE AMOUNT OF A BRIGHTENING AGENT OF THE FORMULA
Claim 3
Dependent Claim
33 words
In an electrolyte as set forth in claim 1, said brightener further comprising an effective amount of a secondary brightener selected from the group consisting of acetophenone, benzalacetone, benzoylacetone, 3-acetyl-coumarin, 3-acetylpyridine, and m-hydroxybenzaldehyde.
Claim 4
Dependent Claim
23 words
In an electrolyte as set forth in claim 2, the amount of said secondary brightener being between 0.01 and 2.0 grams per liter.
Claim 5
Dependent Claim
23 words
In an electrolyte as set forth in claim 1, the amount of said brightening agent being between 0.01 and 10 grams per liter.
Claim 6
Dependent Claim
23 words
In an electrolyte as set forth in claim 1, the amount of said brightening agent being between 0.1 and 1.0 gram per liter.
Claim 7
Independent Claim
75 words
A method of producing a bright electrodeposit of zinc on a conductive substrate which comprises making said substrate the cathode in an aqueous electrolyte at pH 3.0 to 7.0 and a temperature of 15* to 35*C, said electolyte containing 15 to 75 grams per liter zinc ions, at least 50 grams per liter of an inert alkali metal salt of a strong mineral acid, aNd an effective amount of a brightening agent of the formula
Claim 8
Independent Claim
75 words
A method of producing a bright electrodeposit of zinc on a conductive substrate which comprises making said substrate the cathode in an aqueous electrolyte at pH 3.0 to 7.0 and a temperature of 15* to 35*C, said electolyte containing 15 to 75 grams per liter zinc ions, at least 50 grams per liter of an inert alkali metal salt of a strong mineral acid, aNd an effective amount of a brightening agent of the formula
Claim 9
Dependent Claim
23 words
A method as set forth in claim 6, wherein the concentration of said brightening agent is between 0.01 and 10 grams per liter.
Claim 10
Dependent Claim
47 words
A method as set forth in claim 7, wherein said electrolyte further contains an amount of a secondary brightener sufficient to enhance the brightening effect of said brightening agent, said secondary brightener being a member of the group consisting of acetophenone, benzalacetone, benzolyacetone, 3-acetyl-coumarin, 3-acetylpyridine, and m-hydroxybenzaldehyde.
Claim 11
Dependent Claim
43 words
A method as set forth in claim 8, wherein the amount of said secondary brightener in said electrolyte is between 0.01 and 2.0 grams per liter, and the weight ratio of said brightening agent to said secondary brightener is between 1:1 and 10:1.
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) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |