Patent US1684640A successfully refreshed from Google Patents.
US1684640A
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Purifying organic compounds containing oxygen
Assignee: IG Farbenindustrie AG
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Filing: 1926-06-09
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Granted: 1928-09-18
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Expires: 1946-06-09
Abstract
No abstract record available.
Inventors
- 👤 Schmidt Otto
- 👤 Seydel Karl
- 👤 Feller Albert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:20
CPC Classifications
C; C07; C07C; C07C29/00; C07C29/74; C07C29/88; C07C29/90; C07C31/00; C07C31/02; C07C31/04; Y; Y10; Y10T; Y10T24/00; Y10T24/21; Y10T24/2143; Y10T24/2155
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) | 1931-09-18 | 1932-03-19 | 1932-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1935-09-18 | 1936-03-19 | 1936-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1939-09-18 | 1940-03-19 | 1940-09-18 | $7700.00 | Window Closed / Lapsed |