Patent US3290572A successfully refreshed from Google Patents.
Patent US1851021A successfully refreshed from Google Patents.
US1851021A
Expired / Lapsed
US
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Production of synthetic tanning agents
Assignee: IG Farbenindustrie AG
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Filing: 1928-08-11
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Granted: 1932-03-29
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Expires: 1948-08-11
Abstract
No abstract record available.
Inventors
- 👤 Schuette Hermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:59
CPC Classifications
C; C14; C14C; C14C3/00; C14C3/02; C14C3/08; C14C3/18; C14C3/20
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) | 1935-03-29 | 1935-09-28 | 1936-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-03-29 | 1939-09-28 | 1940-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-03-29 | 1943-09-28 | 1944-03-29 | $7700.00 | Window Closed / Lapsed |