Patent US2831879A successfully refreshed from Google Patents.
US2831879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical product and process
Assignee: EIDP Inc
•
Filing: 1953-10-27
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Granted: 1958-04-22
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Expires: 1973-10-27
Abstract
No abstract record available.
Inventors
- 👤 Weinmayr Viktor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:20
CPC Classifications
C; C07; C07F; C07F17/00; C07F17/02
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
27 words
A PROCESS OF PREPARING CYCLOPENTADIENYL (CYCLOPENTENYLCYCLOPENTADIENYL) IRON WHICH COMPRISES HEATING DICYCLOPENTADIENYLIRON WITH HYDROFLUORIC ACID OF AT LEAST 45% CONCENTRATION AT A TEMPERATURE OF FORM 30 TO 100*C.
References Cited (Backward Citations)
US2683157A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-04-21 | 1961-10-21 | 1962-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-04-21 | 1965-10-21 | 1966-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-04-21 | 1969-10-21 | 1970-04-22 | $7700.00 | Window Closed / Lapsed |