US3278595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation and recovery of n, n'-difluoro-urea
Assignee: North American Aviation Corp
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Filing: 1961-04-17
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Granted: 1966-10-11
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Expires: 1981-04-17
Abstract
No abstract record available.
Inventors
- 👤 David F Sheehan
- 👤 Michael G Warner
- 👤 Emil A Lawton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:11
CPC Classifications
C; C07; C07C; C07C275/00; C07C275/66; C07C273/00; C07C273/18; Y; Y10; Y10S; Y10S149/00; Y10S149/119
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
IN A PROCESS FOR PREPARING N,N-DIFFUOROUREA BY REACTING FLUORINE WITH UREA THUS FORMING A REACTION MIXTURE CONTAINING N,N-DIFUOROUREA AND SEPARATING AND N,NDIFLUOROEREA FROM THE REACTION MIXTURE, THE IMPROVEMENT WHICH COMPRISES EXTRACTING SAID REACTION MIXTURE WITH A SOLVENT SELECTED FROM THE CLASS CONSISTING OF CYCLIC ETHERS CONTAINING FROM 5 TO 6 RING ATOMS, SAID RING ATOMS CONSISTING OF CARBON AND OXYGEN WHEREIN AT LEAST ONE OF SAID RING ATOMS IS OXYGEN AND PARTIALLY HALOGENATED ALKANE HYDROCARBONS HAVING FROM 1 TO ABOUT 5 CARBON ATOMS AND SUBSEQUENTLY EVAPORATING SAID SOLVENT TO RECOVER N,NDIFLUOROUREA.
Claim 2
Dependent Claim
91 words
IN A PROCESS FOR PREPARING N,N-DIFFUOROUREA BY REACTING FLUORINE WITH UREA THUS FORMING A REACTION MIXTURE CONTAINING N,N-DIFUOROUREA AND SEPARATING AND N,NDIFLUOROEREA FROM THE REACTION MIXTURE, THE IMPROVEMENT WHICH COMPRISES EXTRACTING SAID REACTION MIXTURE WITH A SOLVENT SELECTED FROM THE CLASS CONSISTING OF CYCLIC ETHERS CONTAINING FROM 5 TO 6 RING ATOMS, SAID RING ATOMS CONSISTING OF CARBON AND OXYGEN WHEREIN AT LEAST ONE OF SAID RING ATOMS IS OXYGEN AND PARTIALLY HALOGENATED ALKANE HYDROCARBONS HAVING FROM 1 TO ABOUT 5 CARBON ATOMS AND SUBSEQUENTLY EVAPORATING SAID SOLVENT TO RECOVER N,NDIFLUOROUREA.
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) | 1969-10-10 | 1970-04-11 | 1970-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-10-10 | 1974-04-11 | 1974-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-10-10 | 1978-04-11 | 1978-10-11 | $7700.00 | Window Closed / Lapsed |