Patent US2829088A successfully refreshed from Google Patents.
US2829088A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of refining dimethylformamide
Assignee: Glanzstoff AG
•
Filing: 1953-11-02
•
Granted: 1958-04-01
•
Expires: 1973-11-02
Abstract
No abstract record available.
Inventors
- 👤 Pirot Ernst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:28
CPC Classifications
C; C07; C07C; C07C233/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
62 words
THE METHOD OF PURIFYING DIMETHYLFORMAMIDE CONTAMINATED WITH DIMETHYLAMINE AND AMMONIA WHICH COMPRISES ADMIXING TO THE DIMETHYLAMINE AND AMMONIA WHICH COMCENT BY WEIGHT OF THE DIMETHYLFORMAMIDE, OF AN AROMATIC COMPOUND SELECTED FROM THE CLASS CONSISTING OF BENZENE, TOLUENCE AND XYLENE, AND SUBJECTING THE MIXTURE THUS OBTAINED TO A FRACTIONAL DISTILLATION WHEREBY TO REMOVE ANY DIMETHYLAMINE AND AMMONIA LEAVING PURIFIED DIMETHYLFORMAMIDE AS A RESIDUE.
Claim 2
Independent Claim
62 words
THE METHOD OF PURIFYING DIMETHYLFORMAMIDE CONTAMINATED WITH DIMETHYLAMINE AND AMMONIA WHICH COMPRISES ADMIXING TO THE DIMETHYLAMINE AND AMMONIA WHICH COMCENT BY WEIGHT OF THE DIMETHYLFORMAMIDE, OF AN AROMATIC COMPOUND SELECTED FROM THE CLASS CONSISTING OF BENZENE, TOLUENCE AND XYLENE, AND SUBJECTING THE MIXTURE THUS OBTAINED TO A FRACTIONAL DISTILLATION WHEREBY TO REMOVE ANY DIMETHYLAMINE AND AMMONIA LEAVING PURIFIED DIMETHYLFORMAMIDE AS A RESIDUE.
References Cited (Backward Citations)
US2106579A
Cited
GB532258A
Cited
US2388217A
Cited
US2570291A
Cited
US2461191A
Cited
US2602817A
Cited
US2677706A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-03-31 | 1961-09-30 | 1962-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-31 | 1965-09-30 | 1966-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-31 | 1969-09-30 | 1970-04-01 | $7700.00 | Window Closed / Lapsed |