Patent US3703598A successfully refreshed from Google Patents.
US3703598A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of p-aminophenol
Assignee: Mallinckrodt Chemical Works
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Filing: 1969-11-04
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Granted: 1972-11-21
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Expires: 1989-11-04
Abstract
Abstract A PROCESS FOR THE PURIFICATION OF CRUDE P-AMINOPHENOL BY RECRYSTALLIZATION FROM AQUEOUS POLYFUNCTIONAL MILD ACIDS, INCLUDING PHOSPHORIC, LACTIC, GLYCOLIC AND CITRIC ACIDS.
Inventors
- 👤 Frank A Baron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:44
CPC Classifications
C; C07; C07C; C07C215/00; C07C215/74; C07C215/76
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) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |