Patent US1310188A successfully refreshed from Google Patents.
Patent US3471549A successfully refreshed from Google Patents.
US3471549A
Expired / Lapsed
US
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Process for the preparation of pure aryl esters of di- and polycarboxylic acids
Assignee: Chemische Werke Witten GmbH
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Filing: 1964-08-05
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Granted: 1969-10-07
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Expires: 1984-08-05
Abstract
No abstract record available.
Inventors
- 👤 Hans-Leo Hulsmann
- 👤 Gustav Renckhoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:35
CPC Classifications
C; C07; C07C; C07C69/00; C07C69/76; C07C69/80; C07C67/00; C07C67/03; C07C69/34; C07C69/82
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB314646A
Cited
US3389164A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-06 | 1973-04-07 | 1973-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-06 | 1977-04-07 | 1977-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-06 | 1981-04-07 | 1981-10-07 | $7700.00 | Window Closed / Lapsed |