US2705727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthesis of ureas
Assignee: EIDP Inc
•
Filing: 1952-07-10
•
Granted: 1955-04-05
•
Expires: 1972-07-10
Abstract
No abstract record available.
Inventors
- 👤 Graham Peter Joseph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:04
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/18; C07C273/1809
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
PROCESS OF SYNTHESIZING UREA WHICH COMPRISES INTIMATELY CONTACTING AN AQUEOUS SOLUTION OF AN ACID SALT OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF AMMONIA, HYDROXYLAMINE, HYDRAZINE AND ORGANIC AMINES HAVING HYDROGEN DIRECTLY ATTACHED TO NITROGEN, AND IN WHICH ACID SALT THE ACID HAS A PKA OF NOT MORE THAN 4.7, WITH A SYNTHETIC POLYMERIC WATER-INSOLUBLE QUATERNARY AMMONIUM ANION EXCHANGE RESIN CHARGED WITH CYANATE ION, SAID ACID BEING OF SUFFICIENT STRENGTH TO FREE THE CYANATE ION AND BEING OTHERWISE INERT.
Claim 2
Dependent Claim
80 words
PROCESS OF SYNTHESIZING UREA WHICH COMPRISES INTIMATELY CONTACTING AN AQUEOUS SOLUTION OF AN ACID SALT OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF AMMONIA, HYDROXYLAMINE, HYDRAZINE AND ORGANIC AMINES HAVING HYDROGEN DIRECTLY ATTACHED TO NITROGEN, AND IN WHICH ACID SALT THE ACID HAS A PKA OF NOT MORE THAN 4.7, WITH A SYNTHETIC POLYMERIC WATER-INSOLUBLE QUATERNARY AMMONIUM ANION EXCHANGE RESIN CHARGED WITH CYANATE ION, SAID ACID BEING OF SUFFICIENT STRENGTH TO FREE THE CYANATE ION AND BEING OTHERWISE INERT.
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) | 1958-04-04 | 1958-10-04 | 1959-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-04-04 | 1962-10-04 | 1963-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-04-04 | 1966-10-04 | 1967-04-05 | $7700.00 | Window Closed / Lapsed |