US3137724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the pressure synthesis of urea
Assignee: Lonza Electric and Chemical Works Ltd
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Filing: 1956-11-19
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Granted: 1964-06-16
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Expires: 1976-11-19
Abstract
No abstract record available.
Inventors
- 👤 Guyer August
- 👤 Matile Pascal
- 👤 Zollinger Werner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:16
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/02; C07C273/04
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
78 words
IN THE SYNTHESIS OF PURE UREA BY THE REACTION OF CARBON DIOXIDE AND A STOICHIOMETRIC EXCESS OF AMMONIA AT ELEVATED PRESSURES AND TEMPERATURES IN APPARATUS HAVING STAINLES STEEL SURFACES EXPOSED TO THE REACTION MEDIUM, THE STEP OF DECREASING THE CORROSIVE EFFECT OF SAID MEDIUM AND THE TURBIDITY OF THE PRODUCT UREA BY INTRODUCING OXYGEN GAS INTO SAID REACTION WITH SAID REACTANTS IN AN AMOUNT EQUAL TO 0.01% TO 0.05% BY VOLUME ON THE AMOUNT OF CARBON DIOXIDE INTRODUCED.
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) | 1967-06-16 | 1967-12-16 | 1968-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-06-16 | 1971-12-16 | 1972-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-06-16 | 1975-12-16 | 1976-06-16 | $7700.00 | Window Closed / Lapsed |