US3575747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical polishing of aluminum
Assignee: SAMUEL L COHN
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Filing: 1969-01-21
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Granted: 1971-04-20
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Expires: 1989-01-21
Abstract
Abstract STRONGLY ACIDIC COMPOSITIONS ARE PROVIDED FOR THE BRIGHT POLISHING OF ALUMINUM, INCLUDING ITS ALLOYS. THE COMPOSITIONS ARE CHARACTERIZED BY THE PRESENCE OF NITRIC ACID IN AMOUNTS RANGING FROM ABOUT 0.25% TO ABOUT 10%, TOGETHER WITH AN EFFECTIVE NITROUS ACID CONTENT OF 0.001% TO 1%, OR MORE. PHOSPHORIC ACID IS USED IN SUBSTANTIAL AMOUNTS IN COMPOSITIONS GIVING HIGHLY SPECULAR FINISHES; THOUGH SMOOTHING IS ACHIEVED WITH PHOSPHORIC ACID AS LOW AS 3%. SULPHURIC ACID IS USED WHEN THE PHOSPHORIC ACID CONTENT IS LOW. MOST DESIRABLE COMPOSITIONS CONTAIN BOTH PHOSPHORIC ACID AND SULPHURIC ACID IN TOTAL AMOUNTS IN EXCESS OF 60%. THE COMPOSITIONS ARE USED AT ELEVATED TEMPERATURES.
Inventors
- 👤 Charles C Cohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:27
CPC Classifications
C; C23; C23F; C23F3/00; C23F3/02; C23F3/03
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) | 1974-04-19 | 1974-10-19 | 1975-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-19 | 1978-10-19 | 1979-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-19 | 1982-10-19 | 1983-04-20 | $7700.00 | Window Closed / Lapsed |