Patent US1897798A successfully refreshed from Google Patents.
US1897798A
Expired / Lapsed
US
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Desulphurization of crude aromatic hydrocarbons
Assignee: IG Farbenindustrie AG
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Filing: 1928-05-28
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Granted: 1933-02-14
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Expires: 1948-05-28
Abstract
No abstract record available.
Inventors
- 👤 Guthke Friedrich Wilhelm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:03
CPC Classifications
C; C10; C10G; C10G45/00; C10G45/02; C10G45/04; C07; C07C; C07C7/00; C07C7/148; C07C7/163
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) | 1936-02-14 | 1936-08-15 | 1937-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-02-14 | 1940-08-15 | 1941-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-02-14 | 1944-08-15 | 1945-02-14 | $7700.00 | Window Closed / Lapsed |