US2498539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of crystallizing urea
Assignee: Compagnie de Produits Chimiques et Electrometallurgiques Alais Froges et Camargue
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Filing: 1947-07-22
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Granted: 1950-02-21
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Expires: 1967-07-22
Abstract
No abstract record available.
Inventors
- 👤 Frejacques Jean Leon Maurice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:48
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/02; C07C273/14; C07C273/16; C05; C05C; C05C9/00; C05C9/005
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
56 words
IN A METHOD OF CRYSTALLIZING UREA IN A STUDY FORM FROM AN AQUEOUS SOLUTION THEREOF, THE STEP OF ADDING TO THE AQUEOUS UREA SOLUTION TO BE CRYSTALLIZED A SMALL AMOUNT, IN RELATION TO THE WEIGHT OF THE SOLUTION TO BE CRYSTALLIZED, OF A MEMBER OF THE GROUP CONSISTING OF CYANURIC ACID AND ITS INORGANIC BASE SALTS.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-02-20 | 1953-08-22 | 1954-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-02-20 | 1957-08-22 | 1958-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-02-20 | 1961-08-22 | 1962-02-21 | $7700.00 | Window Closed / Lapsed |