Patent US2980680A successfully refreshed from Google Patents.
US2980680A
Expired / Lapsed
US
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Separation of isopropanolamine from dimethylpyrazines and dimethylpiperazines
Assignee: Union Carbide Corp
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Filing: 1956-11-26
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Granted: 1961-04-18
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Expires: 1976-11-26
Abstract
No abstract record available.
Inventors
- 👤 George W Fowler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:55
CPC Classifications
C; C07; C07D; C07D295/00; C07D295/02; C07D295/023
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
60 words
A METHOD OF SEPARATING ISOPROPANOLAMINE FROM A MIXTURE THEREOF WITH 2,5-DIMETHYLPIPERAZINE WHICH COMPRISES ADDING TO THE MIXTURE A VOLATILE LIQUID HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF LOWER AKLY BENZENES AND ALIPHATIC HYDROCARBONS HAVING BOILING POINTS BETWEEN 100*C. AND 200*C. AT ATMOSPHERIC PRESSURE, HEATING THE RESULTING MIXTURE AND DISTILLING THEREFROM AN AZETOTROPE CONSISTING PREDOMINATLY OF ISOPROPANOLAMINE AND SAID LIQUID HYDROCARBON.
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) | 1964-04-17 | 1964-10-17 | 1965-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-17 | 1968-10-17 | 1969-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-17 | 1972-10-17 | 1973-04-18 | $7700.00 | Window Closed / Lapsed |