Patent US3012232A successfully refreshed from Google Patents.
US2667451A
Expired / Lapsed
US
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Process for removing small quantities of dimethylamine from dimethylacetamide
Assignee: Solutia Inc
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Filing: 1951-08-25
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Granted: 1954-01-26
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Expires: 1971-08-25
Abstract
No abstract record available.
Inventors
- 👤 Robert J Larson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:41
CPC Classifications
B; B01; B01D; B01D3/00; B01D3/14; C; C07; C07C; C07C209/00; C07C209/82; C07C209/84; C07C231/00; C07C231/22; C07C231/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
96 words
A CONTINUOUS PROCESS FOR REMOVING DIMETHYLAMINE FROM DIMETHYLACETAMIDE CONTAINING BETWEEN 0.2 AND 0.5% DIMETHYLACATAMIDE WHICH COMPRISES, FRACCTIONALLY DISTILLING SAID DIMETHYLACETAMIDE, CONDENSING THE VAPORS PRODUCED AT A TEMPERATURE ABOVE 90* C. AND BELOW THE BOILING POINT OF THE DIMETHYLACETAMIDE CONTAINING THE DIMETHYLAMINE, SEPARATING THE UNCONDENSED DIMETHYLAMINE FROM THE CONDENSATE AT SAID CONDENSING TEMPERATURE, CONTINUOUSLY RETURNING A PORTION OF SAID CONDENSATE TO THE FRACTIONATING STEP, AND FUTHER COOLING THE REMAINDER OF SAID CONDENSATE TO ROOM TEMPERATURE WHILE OUT OF CONTACT WITH SAID DIMETHYLAMINE, SAID COOLED CONDENSATE COMPRISING DIMETHYLACETAMIDE CONTAINING NOT MORE THAN ABOUT 0.001% BY WEIGHT OF DIMETHYLAMINE.
Claim 2
Dependent Claim
96 words
A CONTINUOUS PROCESS FOR REMOVING DIMETHYLAMINE FROM DIMETHYLACETAMIDE CONTAINING BETWEEN 0.2 AND 0.5% DIMETHYLACATAMIDE WHICH COMPRISES, FRACCTIONALLY DISTILLING SAID DIMETHYLACETAMIDE, CONDENSING THE VAPORS PRODUCED AT A TEMPERATURE ABOVE 90* C. AND BELOW THE BOILING POINT OF THE DIMETHYLACETAMIDE CONTAINING THE DIMETHYLAMINE, SEPARATING THE UNCONDENSED DIMETHYLAMINE FROM THE CONDENSATE AT SAID CONDENSING TEMPERATURE, CONTINUOUSLY RETURNING A PORTION OF SAID CONDENSATE TO THE FRACTIONATING STEP, AND FUTHER COOLING THE REMAINDER OF SAID CONDENSATE TO ROOM TEMPERATURE WHILE OUT OF CONTACT WITH SAID DIMETHYLAMINE, SAID COOLED CONDENSATE COMPRISING DIMETHYLACETAMIDE CONTAINING NOT MORE THAN ABOUT 0.001% BY WEIGHT OF DIMETHYLAMINE.
References Cited (Backward Citations)
US1884509A
Cited
US1885029A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-01-25 | 1957-07-27 | 1958-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-01-25 | 1961-07-27 | 1962-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-01-25 | 1965-07-27 | 1966-01-26 | $7700.00 | Window Closed / Lapsed |