US3625844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stainproofing process and products resulting therefrom
Assignee: CIRCULT FOLL CORP
•
Filing: 1969-06-05
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Granted: 1971-12-07
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Expires: 1989-06-05
Abstract
Abstract An electrolytic process for imparting stain resistance to sheet copper comprising rendering the copper sheet cathodic in an electrolytic cell containing an aqueous electrolyte containing about 0.4-0.8 grams/liter of hexavalent chromium ions and subjecting said foil to a current density of about 2-4 amps/ft.2 for about 6-8 seconds. Products resulting therefrom.
Inventors
- 👤 Walter A Mckean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:36
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/28; H05K3/282; C; C25; C25D; C25D11/00; C25D11/38
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
13 words
A process as defined in clAim 1 wherein said copper is copper foil.
Claim 2
Dependent Claim
15 words
A process as defined in claim 1 wherein said electrolyte is substantially free of impurities.
Claim 3
Dependent Claim
14 words
A process as defined in claim 1 wherein said electrolyte contains dissolved chromium trioxide.
Claim 4
Dependent Claim
8 words
The product of the process of claim 2.
Claim 5
Dependent Claim
8 words
The product of the process of claim 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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |