Patent US1891448A successfully refreshed from Google Patents.
US1891448A
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US
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Process of purifying diphenyl-1, 2, 5, 6-anthraquinone dithiazole bodies
Assignee: EIDP Inc
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Filing: 1931-04-20
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Granted: 1932-12-20
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Expires: 1951-04-20
Abstract
No abstract record available.
Inventors
- 👤 William L Rintelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:11
CPC Classifications
C; C09; C09B; C09B5/00; C09B5/24
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) | 1935-12-20 | 1936-06-20 | 1936-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-12-20 | 1940-06-20 | 1940-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-12-20 | 1944-06-20 | 1944-12-20 | $7700.00 | Window Closed / Lapsed |