US3655467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Etching of aluminum base alloys
Assignee: Alcoa Corp
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Filing: 1969-05-14
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Granted: 1972-04-11
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Expires: 1989-05-14
Abstract
Abstract Treating aluminum base alloys with a cleaning-etching solution made up of a caustic and a soluble pyro- or polyphosphate to inhibit formation of an undesirable film thereon.
Inventors
- 👤 Albert L Sopp Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:57
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/32; C23F1/36
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
31 words
The improvement of claim 1 wherein the caustic is sodium hydroxide, potassium hydroxide, tribasic sodium phosphate, or sodium carbonate and the soluble pyro- or polyphosphate is an alkaline pyro- or polyphosphate.
Claim 2
Dependent Claim
36 words
The improvement of claim 1 wherein the caustic is sodium hydroxide, potassium hydroxide, tribasic sodium phosphate, or sodium carbonate and the soluble pyro- or polyphosphate is a tetrapotassium or tetrasodium pyrophosphate or sodium or potassium tripolyphosphate.
Claim 3
Dependent Claim
41 words
The improvement of claim 1 wherein the aluminum base alloy contains magnesium, the caustic is sodium hydroxide, potassium hydroxide, tribasic sodium phosphate or sodium carbonate and the soluble pyro- or polyphosphate is tetrasodium pyrophosphate, sodium tripolyphosphate, tetrapotassium pyrophosphate or potassium tripolyphosphate.
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) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |