Patent US2056663A successfully refreshed from Google Patents.
US2121731A
Expired / Lapsed
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Cellulose ether recovery
Assignee: Dow Chemical Co
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Filing: 1936-07-30
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Granted: 1938-06-21
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Expires: 1956-07-30
Abstract
No abstract record available.
Inventors
- 👤 William R Collings
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:28
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/20; C08B11/22
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) | 1941-06-20 | 1941-12-20 | 1942-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1945-06-20 | 1945-12-20 | 1946-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1949-06-20 | 1949-12-20 | 1950-06-21 | $7700.00 | Window Closed / Lapsed |