US3929595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic burnished gold bath with higher rate of deposition
Assignee: Evonik Operations GmbH
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Filing: 1974-11-04
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Granted: 1975-12-30
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Expires: 1994-11-04
Abstract
Abstract There is provided an electrolytic gold bath for the deposition of thicker, bright gold coatings at high rates of deposition. The bath contains a heterocyclic azohydrocarbon sulfonic acid or salt thereof, e.g. pyridine sulfonic acid.
Inventors
- 👤 Peter Biberbach
- 👤 Werner Dietschmann
- 👤 Hans-Joachim Lubke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:03
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/48
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
65 words
IN AN AQUEOUS, ACIDIC ALKALI GOLD CYANIDE BATH SUITABLE FOR THE ELECTROLYTIC DEPOSITION OF GOLD THE IMPROVEMENT COMPRISING INCLUDING IN THE BATH A HETEROCYCLIC SULFONIC ACID SELECTED FROM THE GROUP CONSISTING OF PYRIDINE SULFONIC ACID, PICOLINE SULFONIC ACID AND QUINOLINE SULFONIC ACID OR A WATER SOLUBLE SALT OF SUCH HETEROCYCLIC SULFONIC ACID IN AN AMOUNT SUFFICIENT OT PROVIDE IMPROVED BRIGHT GOLD DEPOSITION FROM THE BATH.
Claim 2
Dependent Claim
65 words
IN AN AQUEOUS, ACIDIC ALKALI GOLD CYANIDE BATH SUITABLE FOR THE ELECTROLYTIC DEPOSITION OF GOLD THE IMPROVEMENT COMPRISING INCLUDING IN THE BATH A HETEROCYCLIC SULFONIC ACID SELECTED FROM THE GROUP CONSISTING OF PYRIDINE SULFONIC ACID, PICOLINE SULFONIC ACID AND QUINOLINE SULFONIC ACID OR A WATER SOLUBLE SALT OF SUCH HETEROCYCLIC SULFONIC ACID IN AN AMOUNT SUFFICIENT OT PROVIDE IMPROVED BRIGHT GOLD DEPOSITION FROM THE BATH.
Claim 3
Dependent Claim
19 words
A bath according to claim 1 wherein the heterocyclic sulfonic acid is pyridine sulfonic acid or quinoline sulfonic acid.
Claim 4
Dependent Claim
13 words
A bath according to claim 2 wherein the pH is 3.5 to 5.5.
Claim 5
Dependent Claim
15 words
A bath according to claim 2 wherein the heterocyclic sulfonic acid is pyridine sulfonic acid.
Claim 6
Dependent Claim
38 words
A bath according to claim 4 containing 2-15 g/l gold as alkali gold cyanide, 30-200 g/l of a weak organic acid and 1-20 g/l of a pyridine sulfonic acid, said bath having a pH of 3.5 to 5.5.
Claim 7
Dependent Claim
20 words
A bath according to claim 5 including a buffer capable of maintaining the pH within the range 3.5 to 5.5.
Claim 8
Dependent Claim
31 words
A bath according to claim 5 also including 5-100 mg/l of iron, cobalt, nickel, chromium, cadmium, copper, zinc, tin, indium or antimony in the form of a water soluble salt thereof.
Claim 9
Dependent Claim
11 words
A bath according to claim 7 containing 10-30 mg/l of cobalt.
Claim 10
Dependent Claim
11 words
A bath according to claim 7 containing 10-50 mg/l of iron.
Claim 11
Dependent Claim
19 words
A bath according to claim 5 wherein the weak organic acid is an alkanoic acid or a hydroxyalkanoic acid.
Claim 12
Dependent Claim
13 words
A bath according to claim 10 wherein the acid is a hydroxyalkanoic acid.
Claim 13
Dependent Claim
15 words
A bath according to claim 11 wherein the acid is citric acid or tartaric acid.
Claim 14
Dependent Claim
16 words
A bath according to claim 1 containing 1 to 20 g/l of the heterocyclic sulfonic acid.
Claim 15
Dependent Claim
36 words
A process of electrolytically depositing a glossy gold coating on an aRticle comprising placing the article in the bath of claim 1 and passing a current therethrough at a current density of 0.5 to 12 A/dm2.
Claim 16
Dependent Claim
36 words
A process of electrolytically depositing a glossy gold coating on an article comprising placing the article in the bath of claim 1 and passing a current therethrough at a current density of 2 to 6 A/dm2.
Claim 17
Dependent Claim
36 words
A process of electrolytically depositing a bright gold coating on an article comprising placing the article in the bath of claim 5 and passing a current therethrough at a current density of 0.5 to 12 A/dm2.
Claim 18
Dependent Claim
36 words
A process of electrolytically depositing a bright gold coating on an article comprising placing the article in the bath of claim 5 and passing a current therethrough at a current density of 2 to 6 A/dm2.
Claim 19
Dependent Claim
36 words
A process of electrolytically depositing a bright gold coating on an article comprising placing the article in the bath of claim 7 and passing a current therethrough at a current density of 0.5 to 12 A/dm2.
Claim 20
Dependent Claim
14 words
A process according to claim 18 wherein the bath contains 10-30 mg/l of cobalt.
Claim 21
Dependent Claim
14 words
A process according to claim 18 wherein the bath contains 10-50 mg/l of iron.
Claim 22
Dependent Claim
36 words
A process of electrolytically depositing a bright gold coating on an article comprising placing the article in the bath of claim 7 and passing a current therethrough at a current density of 2 to 6 A/dm2.
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) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |