Patent US2683160A successfully refreshed from Google Patents.
US2683160A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of aromatic isocyanates
Assignee: EIDP Inc
•
Filing: 1953-03-19
•
Granted: 1954-07-06
•
Expires: 1973-03-19
Abstract
No abstract record available.
Inventors
- 👤 Carl F Irwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:59
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
115 words
IN THE PREPARATION OF AN AROMATIC ISOCYANATE BOILING ABOVE 132* C., THE STEPS WHICH COMPRISES MAINTAINING AT THE BOILING POINT UNDER REFLUX AT A TEMPERATURE BETWEEN 130* AND 300* C. A SOLUTION OF THE SAID ISOCYANATE IN A CHLORINATED AROMATIC HYDROCARBON SOLVENT HAVING A BOILING POINT AT ATMOSPHERIC PRESSURE WITHIN THE SAID TEMPERATURE RANGE AND BELOW THE BOILING POINT OF THE SAID ISOCYANATE, ADDING SIMULTANEOUSLY THERETO (1) A 5 TO 30% BY WEIGHT SOLUTION OF THE AROMATIC PRIMARY AMINE WHICH CORRESPONDS TO THE SAID ISOCYANATE DISSOLVED IN THE SAID SOLVENT AND (2) PHOSGENE IN AT LEAST 50% STOICHIOMETRIC EXCESS IN RELATION TO THE AMINE, AND WITHDRAWING HYDROGEN CHLORIDE AND UNREACTED PHOSGENE THROUGH THE REFLUX CONDENSER.
Claim 2
Dependent Claim
115 words
IN THE PREPARATION OF AN AROMATIC ISOCYANATE BOILING ABOVE 132* C., THE STEPS WHICH COMPRISES MAINTAINING AT THE BOILING POINT UNDER REFLUX AT A TEMPERATURE BETWEEN 130* AND 300* C. A SOLUTION OF THE SAID ISOCYANATE IN A CHLORINATED AROMATIC HYDROCARBON SOLVENT HAVING A BOILING POINT AT ATMOSPHERIC PRESSURE WITHIN THE SAID TEMPERATURE RANGE AND BELOW THE BOILING POINT OF THE SAID ISOCYANATE, ADDING SIMULTANEOUSLY THERETO (1) A 5 TO 30% BY WEIGHT SOLUTION OF THE AROMATIC PRIMARY AMINE WHICH CORRESPONDS TO THE SAID ISOCYANATE DISSOLVED IN THE SAID SOLVENT AND (2) PHOSGENE IN AT LEAST 50% STOICHIOMETRIC EXCESS IN RELATION TO THE AMINE, AND WITHDRAWING HYDROGEN CHLORIDE AND UNREACTED PHOSGENE THROUGH THE REFLUX CONDENSER.
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) | 1957-07-05 | 1958-01-04 | 1958-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-07-05 | 1962-01-04 | 1962-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-07-05 | 1966-01-04 | 1966-07-06 | $7700.00 | Window Closed / Lapsed |