US4411743A
Expired / Lapsed
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Electrolytic palladium bath and process
Assignee: DEHUSSA AG SCHAFT
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Filing: 1982-04-22
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Granted: 1983-10-25
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Expires: 2002-04-22
Abstract
Abstract There is described an electrolytic palladium bath containing palladium sulfite and an acid which produces coatings that satisfy all industrial requirements and which is not corrosive to the base metal. The bath contains sulfuric and/or phosphoric acid and employs 80-95% of palladium as palladium sulfate, the balance as palladium sulfite.
Inventors
- 👤 Erika Kreuter
- 👤 Wolfgang Zilske
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:16
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/50
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
29 words
An electrolytic aqueous palladium nitrate-free bath containing palladium sulfite and an acid wherein the bath contains 80-95% of the palladium as palladium sulfate and the balance as palladium sulfite.
Claim 2
Dependent Claim
29 words
An electrolytic aqueous palladium nitrate-free bath containing palladium sulfite and an acid wherein the bath contains 80-95% of the palladium as palladium sulfate and the balance as palladium sulfite.
Claim 3
Dependent Claim
15 words
An electrolytic bath according to claim 1 which contains 2 to 50 g/l of palladium.
Claim 4
Dependent Claim
24 words
An electrolytic bath according to claim 2 containing 40-100 g/l of sulfuric acid, phosphoric acid, or a mixture of phosphoric acid and sulfuric acid.
Claim 5
Dependent Claim
13 words
An electrolytic bath according to claim 3 consisting essentially of the stated materials.
Claim 6
Dependent Claim
12 words
An electrolytic bath according to claim 3 consisting of the stated materials.
Claim 7
Dependent Claim
39 words
A method of electroplating palladium on an article comprising placing the article in the bath of claim 3 and depositing palladium on the article at a temperature of 20°-40° C. and a current density of 0.2-10 A/dm 2 .
Claim 8
Dependent Claim
46 words
An electrolytic bath according to claim 2 containing 40-100 g/l of (1) phosphoric acid alone or (2) a mixture of phosphoric acid and sulfuric acid, the sulfuric acid being present in an amount not over 50% based on the weight of phosphoric acid and sulfuric acid.
Claim 9
Dependent Claim
40 words
An electrolytic bath according to claim 7 containing 5 to 20% of palladium in the bath in the form of palladium sulfite produced by the addition of sodium sulfite or sulfurous acid to a palladium salt in the bath itself.
Claim 10
Dependent Claim
13 words
An electrolytic bath according to claim 7 consisting essentially of the stated materials.
Claim 11
Dependent Claim
40 words
An electrolytic bath according to claim 2 containing 5 to 20% of palladium in the bath in the form of palladium sulfite produced by the addition of sodium sulfite or sulfurous acid to a palladium salt in the bath itself.
Claim 12
Dependent Claim
13 words
An electrolytic bath according to claim 2 consisting essentially of the stated materials.
Claim 13
Dependent Claim
39 words
A method of electroplating palladium on an article comprising placing the article in the bath of claim 2 and depositing palladium on the article at a temperature of 20°-40° C. and a current density of 0.2-10 A/dm 2 .
Claim 14
Dependent Claim
24 words
An electrolytic bath according to claim 1 containing 40-100 g/l of sulfuric acid, phosphoric acid, or a mixture of phosphoric acid and sulfuric acid.
Claim 15
Dependent Claim
40 words
An electrolytic bath according to claim 13 containing 5 to 20% of palladium in the bath in the form of palladium sulfite produced by the addition of sodium sulfite or sulfurous acid to a palladium salt in the bath itself.
Claim 16
Dependent Claim
13 words
An electrolytic bath according to claim 13 consisting essentially of the stated materials.
Claim 17
Dependent Claim
14 words
An electrolytic bath according to claim 13 containing phosphoric acid as the sole acid.
Claim 18
Dependent Claim
14 words
An electrolytic bath according to claim 13 containing sulfuric acid as the sole acid.
Claim 19
Dependent Claim
46 words
An electrolytic bath according to claim 1 containing 40-100 g/l of (1) phosphoric acid alone or (2) a mixture of phosphoric acid and sulfuric acid, the sulfuric acid being present in an amount not over 50% based on the weight of phosphoric acid and sulfuric acid.
Claim 20
Dependent Claim
40 words
An electrolytic bath according to claim 18 containing 5 to 20% of palladium in the bath in the form of palladium sulfite produced by the addition of sodium sulfite or sulfurous acid to a palladium salt in the bath itself.
Claim 21
Dependent Claim
13 words
An elecrolytic bath according to claim 18 consisting essentially of the stated materials.
Claim 22
Dependent Claim
12 words
An electrolytic bath according to claim 18 consisting of the stated materials.
Claim 23
Dependent Claim
23 words
An electrolytic bath according to claim 18 containing 10 to 50% sulfuric acid based on the weight of phosphoric acid and sulfuric acid.
Claim 24
Dependent Claim
40 words
An electrolytic bath according to claim 1 containing 5 to 20% of palladium in the bath in the form of palladium sulfite produced by the addition of sodium sulfite or sulfurous acid to a palladium salt in the bath itself.
Claim 25
Dependent Claim
13 words
An electrolytic bath according to claim 1 consisting essentially of the stated materials.
Claim 26
Dependent Claim
39 words
A method of electroplating palladium on an article comprising placing the article in the bath of claim 1 and depositing palladium on the article at a temperature of 20°-40° C. and a current density of 0.2-10 A/dm 2 .
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) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |