US4391679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic bath and process for the deposition of gold alloy coatings
Assignee: Evonik Operations GmbH
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Filing: 1981-04-02
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Granted: 1983-07-05
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Expires: 2001-04-02
Abstract
Abstract In the electro industry, there are needed acid gold alloy baths which give glossy, ductile coatings, operate at high current densities, and contain little non-metallic impurities. This is attained by a bath based on potassium cyanoaurate (III) and an acid whereby the bath contains at least one of the alloying metals cobalt, nickel, indium, tin, zinc, or cadmium in the form of a water soluble salt, together with an amine, an aminocarboxylic acid, or a phosphonic acid and has a pH of below 3.
Inventors
- 👤 Wolfgang Zilske
- 👤 Werner Kuhn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:59
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/62
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
108 words
A gold bath suitable for the deposition of high gloss and ductile gold alloy coatings consisting of either (1) water, potassium cyanoaurate (III), at least one alloying element selected from the group consisting of cobalt, nickel, indium, zinc, and cadmium in the form of a water soluble salt together with a hydrocarbyl amine, an aminocarboxylic acid, or a phosphonic acid which forms a complex with the alloying element and 20-200 g/l of sulfuric acid, phosphoric acid, citric acid or a mixture thereof, or (2) the gold bath (1) together with potassium dihydrogen phosphate, potassium hydrogen sulfate or potassium citrate, said bath having a pH of less than 3.
Claim 2
Dependent Claim
108 words
A gold bath suitable for the deposition of high gloss and ductile gold alloy coatings consisting of either (1) water, potassium cyanoaurate (III), at least one alloying element selected from the group consisting of cobalt, nickel, indium, zinc, and cadmium in the form of a water soluble salt together with a hydrocarbyl amine, an aminocarboxylic acid, or a phosphonic acid which forms a complex with the alloying element and 20-200 g/l of sulfuric acid, phosphoric acid, citric acid or a mixture thereof, or (2) the gold bath (1) together with potassium dihydrogen phosphate, potassium hydrogen sulfate or potassium citrate, said bath having a pH of less than 3.
Claim 3
Dependent Claim
17 words
A gold bath according to claim 1 wherein the bath has a pH between 0.4 and 2.5.
Claim 4
Dependent Claim
15 words
A gold bath according to claim 2 wherein the pH is between 0.6 and 2.0.
Claim 5
Dependent Claim
22 words
A gold bath according to claim 2 wherein the bath contains 1-20 g/l of gold in the form of potassium cyanoaurate (III).
Claim 6
Dependent Claim
18 words
A gold bath according to claim 4 which contains potassium dihydrogen phosphate, potassium hydrogen sulfate, or potassium citrate.
Claim 7
Dependent Claim
22 words
A gold bath according to claim 5, including 0.1-20 g/l of the alloying element in the form of a water soluble salt.
Claim 8
Dependent Claim
18 words
A gold bath according to claim 6, including 1-100 g/l of the amine, aminocarboxylic acid, or phosphonic acid.
Claim 9
Dependent Claim
22 words
A gold bath according to claim 4, including 0.1-20 g/l of the alloying element in the form of a water soluble salt.
Claim 10
Dependent Claim
18 words
A gold bath according to claim 8, including 1-100 g/l of the amine, aminocarboxylic acid, or phosphonic acid.
Claim 11
Dependent Claim
12 words
A gold bath according to claim 1 which is gold bath (1).
Claim 12
Dependent Claim
13 words
A gold bath according to claim 1 wherein the alloying element is cobalt.
Claim 13
Dependent Claim
13 words
A gold bath according to claim 1 wherein the alloying element is nickel.
Claim 14
Dependent Claim
13 words
A gold bath according to claim 1 wherein the alloying element is indium.
Claim 15
Dependent Claim
34 words
A process of depositing a high gloss and ductile gold alloy coating on a base metal comprising employing the gold bath of claim 7 with an electric current at a temperature of 40°-60° C.
Claim 16
Dependent Claim
15 words
A process according to claim 14 wherein the current density is 0.1-20 A/dm 2 .
Claim 17
Dependent Claim
34 words
A process of depositing a high gloss and ductile gold alloy coating on a base metal comprising employing the gold bath of claim 9 with an electric current at a temperature of 40°-60° C.
Claim 18
Dependent Claim
15 words
A process according to claim 16 wherein the current density is 0.1-20 A/dm 2 .
Claim 19
Dependent Claim
35 words
A process of depositing a high gloss and ductile coating on a base metal comprising employing the gold bath of claim 9 with an electric current at a current density of 0.1-20 A/dm 2 .
Claim 20
Dependent Claim
34 words
A process of depositing a high gloss and ductile gold alloy coating on a base metal comprising employing the gold bath of claim 1 with an electric current at a temperature of 40°-60° C.
Claim 21
Dependent Claim
15 words
A process according to claim 19 wherein the current density is 0.1-20 A/dm 2 .
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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) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |