Patent US2425991A successfully refreshed from Google Patents.
US2425991A
Expired / Lapsed
US
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Preparation of difluoroethane
Assignee: EIDP Inc
•
Filing: 1945-12-07
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Granted: 1947-08-19
•
Expires: 1965-12-07
Abstract
No abstract record available.
Inventors
- 👤 Robert E Burk
- 👤 Donald D Coffman
- 👤 George H Kalb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:07
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/07; C07C17/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB307802A
Cited
US2186916A
Cited
US2135454A
Cited
US2182617A
Cited
US2118901A
Cited
US2291510A
Cited
US2324073A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-08-18 | 1951-02-17 | 1951-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-08-18 | 1955-02-17 | 1955-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-08-18 | 1959-02-17 | 1959-08-19 | $7700.00 | Window Closed / Lapsed |