US2643264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for synthesizing 4, 4'biphenyl diisocyanate
Assignee: Wingfoot Corp
•
Filing: 1949-12-29
•
Granted: 1953-06-23
•
Expires: 1969-12-29
Abstract
No abstract record available.
Inventors
- 👤 Ernest E Fauser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:53
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
100 words
A METHOD FOR THE CONVERSION OF BENZIDINE TO 4,4'' BIPHENYL DIISOCYANATE WHICH COMPRISES ADDING A SOLUTION OF BENZIDINE IN AN INERT SOLVENT, SAID BENZIDINE BEING COMPLETELY DISSOLVED IN SAID SOLVENT BY HEAING AND BEING PRESENT IN THE SOLVENT IN A CONCENTRATION RANGING FROM 2 GRAMS TO 25 GRAMES PER 100 MILLILITERS OF SOLVENT IN THE FINAL REACTION MIXTURE, TO A SOLUTION OF PHOSGENE IN AN INERT SOLVENT, MAINTAINING THE TEMPERATURE OF THE REACTING MIXTURE BELOW 50* C. UNTIL ALL THE BENZIDINE SOLUTION HAS BEEN ADDED TO THE PHOSGENE SOLUTION, AND THEN HEATING THE REACTION MIXTURE TO DRIVE OFF HYDROGEN CHLORIDE.
Claim 2
Independent Claim
100 words
A METHOD FOR THE CONVERSION OF BENZIDINE TO 4,4'' BIPHENYL DIISOCYANATE WHICH COMPRISES ADDING A SOLUTION OF BENZIDINE IN AN INERT SOLVENT, SAID BENZIDINE BEING COMPLETELY DISSOLVED IN SAID SOLVENT BY HEAING AND BEING PRESENT IN THE SOLVENT IN A CONCENTRATION RANGING FROM 2 GRAMS TO 25 GRAMES PER 100 MILLILITERS OF SOLVENT IN THE FINAL REACTION MIXTURE, TO A SOLUTION OF PHOSGENE IN AN INERT SOLVENT, MAINTAINING THE TEMPERATURE OF THE REACTING MIXTURE BELOW 50* C. UNTIL ALL THE BENZIDINE SOLUTION HAS BEEN ADDED TO THE PHOSGENE SOLUTION, AND THEN HEATING THE REACTION MIXTURE TO DRIVE OFF HYDROGEN CHLORIDE.
References Cited (Backward Citations)
US2362648A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-22 | 1956-12-22 | 1957-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-22 | 1960-12-22 | 1961-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-22 | 1964-12-22 | 1965-06-23 | $7700.00 | Window Closed / Lapsed |