Patent US1856144A successfully refreshed from Google Patents.
US1856144A
Expired / Lapsed
US
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Production of phosphoric acid
Assignee: IG Farbenindustrie AG
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Filing: 1931-04-13
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Granted: 1932-05-03
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Expires: 1951-04-13
Abstract
No abstract record available.
Inventors
- 👤 Wietzel Gustav
- 👤 Haubach Ferdinand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:49
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/234; C01B25/237; C01B25/2372
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) | 1935-05-03 | 1935-11-02 | 1936-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-05-03 | 1939-11-02 | 1940-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-05-03 | 1943-11-02 | 1944-05-03 | $7700.00 | Window Closed / Lapsed |