Patent US2971010A successfully refreshed from Google Patents.
US2971010A
Expired / Lapsed
US
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Production of dicarboxylic acid anhydrides
Assignee: DuPont Canada Inc
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Filing: 1958-06-26
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Granted: 1961-02-07
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Expires: 1978-06-26
Abstract
No abstract record available.
Inventors
- 👤 Jr Ralph Fredrick Gilby
- 👤 Hoberg Charles Edward
- 👤 Phibbs Murray Kenneth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:51
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/56; C07C51/573
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
67 words
IN A SIMULTANEOUS DEHYDRATION-DISTILLATION PROCESS FOR THE PREPARTION AND SEPARATION OF SUCCINE AND GLUTARIC ANHYDRIDES, THE STEPS WHICH COMPRISE HEATING A MIXTURE OF SUCCINIC, GLUTARIC AND ADIPIC ACIDS TO A TEMPERATURE BETWEEN 190* AND 280*C. AND AT A PRESSURE BETWEEN 10 AND 400 MM. HG ABSOLUTE AND SUCCESSIVELY DISTILLING FROM THE REACTION MIXTURE-FIRST, SUCCINIC ANHYDRIDE WITH WATER OF DEHYDRATION, AND SECOND, GLUTARIC ANHYDRIDE WITH WATER OF DEHYDRATION.
Claim 2
Dependent Claim
67 words
IN A SIMULTANEOUS DEHYDRATION-DISTILLATION PROCESS FOR THE PREPARTION AND SEPARATION OF SUCCINE AND GLUTARIC ANHYDRIDES, THE STEPS WHICH COMPRISE HEATING A MIXTURE OF SUCCINIC, GLUTARIC AND ADIPIC ACIDS TO A TEMPERATURE BETWEEN 190* AND 280*C. AND AT A PRESSURE BETWEEN 10 AND 400 MM. HG ABSOLUTE AND SUCCESSIVELY DISTILLING FROM THE REACTION MIXTURE-FIRST, SUCCINIC ANHYDRIDE WITH WATER OF DEHYDRATION, AND SECOND, GLUTARIC ANHYDRIDE WITH WATER OF DEHYDRATION.
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) | 1964-02-07 | 1964-08-08 | 1965-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-02-07 | 1968-08-08 | 1969-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-02-07 | 1972-08-08 | 1973-02-07 | $7700.00 | Window Closed / Lapsed |