US3597473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of purifying ethyleneglycol methacrylate
Assignee: Czech Academy of Sciences
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Filing: 1968-05-14
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Granted: 1971-08-03
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Expires: 1988-05-14
Abstract
Abstract IF ETHYLENEGLYCOL MONOMETHACRYLATE IS CONTAMINATED WITH ETHYLENEGLCOL DIMETHACRYLATE, THE DIESTER CAN BE REMOVED LARGELY BY CRYSTALLIZATION OF THE MONOESTER FROM A NORMALLY LIQUID SOLVENT MEDIUM AT A TEMPERATURE BELOW THE MELTING POINT OF THE DIESTER, TYPICALLY -20* TO -50* C. IF THE CRUDE MATERIAL CONTAINS MUCH ETHYLENEGLYCOL, THE ESTERS MAY BE SEPARATED FROM THE GLYCOL BY DISSOLVING THE MIXTURE IN WATER AND SALTING THE ESTERS OUT AS AN ORGANIC PHASE WHICH MAY BE FURTHER PURIFIED BY DISTILLATION OR BY LOW-TEMPERATURE CRYSTALLIZATION.
Inventors
- 👤 Richard Chromecek
- 👤 Otto Wichterle
- 👤 Iva Gavrilova
- 👤 Jiri Vacik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:52
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/48; C07C67/52; C07C67/58
Claims Analysis
Total Claims: 0
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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) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |