Patent US2797232A successfully refreshed from Google Patents.
US2797232A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hidden polyisocyanates
Assignee: Bayer AG
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Filing: 1954-03-31
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Granted: 1957-06-25
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Expires: 1974-03-31
Abstract
No abstract record available.
Inventors
- 👤 Bunge Wilhelm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:05
CPC Classifications
C; C07; C07C; C07C271/00; C08; C08L; C08L75/00; C08L75/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
86 words
PROCESS FOR THE CONVERSION OF POLYISOCYANATES AND DICARBOXYLIC ACIDS INTO URETHANES CAPABLE OF BEING THERMALLY DECOMPOSED INTO POLYISOCYANATES HAVING A HIGHER MOLECULAR WEIGHT THAN THE STARTING MATERIAL, WHICH COMPRISES CONTACTING A HYDROXY-ALKYL-CARBAMIC ACID-ARYL ESTER WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF ORGANIC DIISOCYANATES, ORGANIC TRIISOCYANATES, DICARBOXYLIC ACIDS, AND FUNCTIONAL DERIVATIVES OF DICARBOXYLIC ACIDS AT A TEMPERATURE BELOW ABOUT 150*C., AND RECOVERING THE URETHANE FORMED, WHICH IS CAPABLE OF YIELDING AT INCREASED TEMPERATURES A FREE POLYISOCYANATE HAVING A HIGHER MOLECULAR WEIGHT THAN SAID GROUP MEMBER.
Claim 2
Dependent Claim
86 words
PROCESS FOR THE CONVERSION OF POLYISOCYANATES AND DICARBOXYLIC ACIDS INTO URETHANES CAPABLE OF BEING THERMALLY DECOMPOSED INTO POLYISOCYANATES HAVING A HIGHER MOLECULAR WEIGHT THAN THE STARTING MATERIAL, WHICH COMPRISES CONTACTING A HYDROXY-ALKYL-CARBAMIC ACID-ARYL ESTER WITH A MEMBER SELECTED FROM THE GROUP CONSISTING OF ORGANIC DIISOCYANATES, ORGANIC TRIISOCYANATES, DICARBOXYLIC ACIDS, AND FUNCTIONAL DERIVATIVES OF DICARBOXYLIC ACIDS AT A TEMPERATURE BELOW ABOUT 150*C., AND RECOVERING THE URETHANE FORMED, WHICH IS CAPABLE OF YIELDING AT INCREASED TEMPERATURES A FREE POLYISOCYANATE HAVING A HIGHER MOLECULAR WEIGHT THAN SAID GROUP MEMBER.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-06-24 | 1960-12-24 | 1961-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-06-24 | 1964-12-24 | 1965-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-06-24 | 1968-12-24 | 1969-06-25 | $7700.00 | Window Closed / Lapsed |