US3804731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming hard anodic oxide film on aluminum base alloy
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1972-09-01
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Granted: 1974-04-16
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Expires: 1992-09-01
Abstract
Abstract A HARD ANODIC OXIDE FILM IS FORMED UNIFORMLY ON AN ALUMINUM BASE ALLOY CONTAINING 1% BY WEIGHT OR MORE OF COPPER BY SUBJECTING THE ALUMINUM BASE ALLOY OT ANODIC OXIDATION USING AN ELECTROLYTE COMPRISING AN AQUEOUS SOLUTION CONTAINING 5 TO 40% BY WEIGHT OF AN AROMATIC SULFONIC ACID SUCH AS SULFOSALICYLIC ACID, NAPTHALENEDISULFONIC ACID, NAPHTHALENE-TRISULFONIC ACID, PHENOL SULFONIC ACID AND SULFOPHTHALIC ACID, AND 15 TO 40% BY WEIGHT OF SULFURIC ACID.
Inventors
- 👤 K Yanagida
- 👤 T Tsukiyasu
- 👤 S Iwata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:12
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-15 | 1977-10-15 | 1978-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-15 | 1981-10-15 | 1982-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-15 | 1985-10-15 | 1986-04-16 | $7700.00 | Window Closed / Lapsed |