Patent US2910477A successfully refreshed from Google Patents.
US2910477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of piperazine
Assignee: Dow Chemical Co
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Filing: 1956-10-18
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Granted: 1959-10-27
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Expires: 1976-10-18
Abstract
No abstract record available.
Inventors
- 👤 Jr Merton Wayne Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:05
CPC Classifications
C; C07; C07D; C07D295/00; C07D295/02; C07D295/023
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
48 words
PIPERAZINE MANUFACTURING PROCESS CONSISTING ESSENTIALLY OF AMMONATING EACH MOLE OF DIETHANOLAMINE WITH ABOUT 3 TO 15 MOLES OF AMMONIA IN THE PRESENCE OF A RANEY NICKEL CATALYST MASS IN THE THERMAL RANGE FROM ABOUT 125 TO 300*C. AND UNDER 500 TO 2,500 POUNDS PER SQUARE INCH OF PRESSURE.
Claim 2
Dependent Claim
48 words
PIPERAZINE MANUFACTURING PROCESS CONSISTING ESSENTIALLY OF AMMONATING EACH MOLE OF DIETHANOLAMINE WITH ABOUT 3 TO 15 MOLES OF AMMONIA IN THE PRESENCE OF A RANEY NICKEL CATALYST MASS IN THE THERMAL RANGE FROM ABOUT 125 TO 300*C. AND UNDER 500 TO 2,500 POUNDS PER SQUARE INCH OF PRESSURE.
References Cited (Backward Citations)
US2525223A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-10-26 | 1963-04-27 | 1963-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-10-26 | 1967-04-27 | 1967-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-10-26 | 1971-04-27 | 1971-10-27 | $7700.00 | Window Closed / Lapsed |