US3033864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of pyrazine
Assignee: Dow Chemical Co
•
Filing: 1954-10-13
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Granted: 1962-05-08
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Expires: 1974-10-13
Abstract
No abstract record available.
Inventors
- 👤 Edgar C Britton
- 👤 Lee H Horsley
- 👤 David B Kellom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:10
CPC Classifications
C; C07; C07D; C07D241/00; C07D241/02; C07D241/10; C07D241/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
81 words
A METHOD OF SEPARATING A LOWER ALKANOLAMINE FROM A MIXTURE THEREOF WITH A PYRAZINE SELECTED FROM THE CLASS CONSISTING OF PYRAZINE AND LOWER ALKYL PYRAZINES WHICH COMPRISES ADDING TO THE MIXTURE A VOLATILE LIQUID HAVING A NORMAL BOILING POINT NOT HIGHER THAN 200* C. SELECTED FROM THE CLASS CONSISTING OF SATURATED ALIPHATIC HYDROCARBONS HAVING AT LEAST EIGHT CARBON ATOMS, LOWER ALKYLBENZENES, AND CHLOROBENZENE, HEATING THE MIXTURE AND DISTILLING THEREFROM AN AZEOTROPE CONSISTING PREDOMINANTLY OF THE LOWER ALKANOLAMINE AND SAID VOLATILE LIQUID.
Claim 2
Independent Claim
81 words
A METHOD OF SEPARATING A LOWER ALKANOLAMINE FROM A MIXTURE THEREOF WITH A PYRAZINE SELECTED FROM THE CLASS CONSISTING OF PYRAZINE AND LOWER ALKYL PYRAZINES WHICH COMPRISES ADDING TO THE MIXTURE A VOLATILE LIQUID HAVING A NORMAL BOILING POINT NOT HIGHER THAN 200* C. SELECTED FROM THE CLASS CONSISTING OF SATURATED ALIPHATIC HYDROCARBONS HAVING AT LEAST EIGHT CARBON ATOMS, LOWER ALKYLBENZENES, AND CHLOROBENZENE, HEATING THE MIXTURE AND DISTILLING THEREFROM AN AZEOTROPE CONSISTING PREDOMINANTLY OF THE LOWER ALKANOLAMINE AND SAID VOLATILE LIQUID.
References Cited (Backward Citations)
US2940933A
Cited
US2980680A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-05-07 | 1965-11-06 | 1966-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-05-07 | 1969-11-06 | 1970-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-05-07 | 1973-11-06 | 1974-05-08 | $7700.00 | Window Closed / Lapsed |