US2993906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of imidazolidones
Assignee: Metro Atlantic Inc
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Filing: 1958-03-10
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Granted: 1961-07-25
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Expires: 1978-03-10
Abstract
No abstract record available.
Inventors
- 👤 Gerhard E Sprenger
- 👤 Hans W Albrecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:37
CPC Classifications
C; C07; C07D; C07D233/00; C07D233/04; C07D233/28; C07D233/30; C07D233/32; B; B01; B01J; B01J39/00; B01J39/04; B01J39/05; C07D233/34
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
59 words
A PROCESS OF TREATING CRUDE ETHYLENE UREA TO PURIFY THE SAME WHICH COMPRISES TREATING A 40 TO 70% BY WEIGHT AQUEOUS SOLUTION OF THE ETHYLENE UREA AT A TEMPERATURE OF 25 TO 90*C. FOR 1/2 TO 4 HOURS WITH A POLYSTYRENE SULPHONIC ACID CATION ACTIVE BASE EXCHANGE RESIN AND THEN REMOVING THE WATER TO OBTAIN A PURIFIED ETHYLENE UREA.
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) | 1964-07-24 | 1965-01-23 | 1965-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-24 | 1969-01-23 | 1969-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-24 | 1973-01-23 | 1973-07-25 | $7700.00 | Window Closed / Lapsed |