US2642449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of polyisocyanates
Assignee: —
•
Filing: —
•
Granted: 1953-06-16
•
Expires: 1970-06-16
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:26
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/10; C07C265/00; C07C265/12; C07C265/14
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
112 words
THE METHOD FOR PREPARING ORGANIC POLYISOCYANATES WHICH COMPRISES MIXING TOGETHER IN A CLOSED SYSTEM AN EXCESS OF PHOSGENE WITH A COMPOUND SELECTED FROM THE CLASS CONSISTING OF POLY PRIMARY AMINES AND ACID SALTS OF POLY PRIMARY AMINES AT A TEMPERATURE FROM 10* C. TO 30* C., HEATING THESE REACTANTS TO A TEMPERATURE FROM ABOUT 100* C. TO 200* C. AND AT A PRESSURE OF FROM ABOUT FOUR ATMOSPHERES TO THAT CORRESPONDING TO THE TOTAL VAPOR PRESSURE OF THE REACTION MEDIUM AT THE REACTION TEMPERATURE, REMOVING THE VOLATILE REACTION BY-PRODUCTS SUBSTANTIALLY AS RAPIDLY AS FORMED WHILE SUBSTANTIALLY RETAINING THE PHOSGENE WITHIN THE CLOSED SYSTEM, THEN REMOVING THE UNREACTED PHOSGENE AND RECOVERING THE POLYISOCYANATE.
References Cited (Backward Citations)
US2374340A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-15 | 1956-12-15 | 1957-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-15 | 1960-12-15 | 1961-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-15 | 1964-12-15 | 1965-06-16 | $7700.00 | Window Closed / Lapsed |