US3640967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of polyurethanes
Assignee: Bayer AG
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Filing: 1969-04-21
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Granted: 1972-02-08
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Expires: 1989-04-21
Abstract
Abstract A PROCESS FOR THE PREPARATION OF POLYURETHANES, WHICH MAY OR MAY NOT BE CROSS-LINKED, FROM HIGHER MOLECULAR WEIGHT, LINEAR DIHYDROXY COMPOUNDS, DIISOCYANATES AND LOW MOLECULAR WEIGHT CHAIN LENGTHENING AGENTS WHICH CONTAIN AT LEAST TOW HYDROGEN ATOMS THAT ARE REACTIVE WITH ISOCYANATES, CHARACTERIZED IN THAT THE HIGHER MOLECULAR WEIGHT DIHYDROXY COMPOUNDS USED ARE REACTION PRODUCTS OF $-CAPROLACTONE AND/OR $-HYDROXYCAPROIC ACID, HEXANE-1,6-DIOL AND DIARYL CARBONATES.
Inventors
- 👤 Klaus Konig
- 👤 Erwin Muller
- 👤 Wilhelm Kallert
- 👤 Cornelius Muhlhausen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:47
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/67; C08G18/675; C07; C07C; C07C243/00; C07C243/24; C07C243/26; C07C243/34; C08G18/08; C08G18/10; C08G18/40; C08G18/42; C08G18/4266; C08G18/4269; C08G18/4277; C08G18/4283; C08G18/44; C08G18/65; C08G18/66; C08G18/6633
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |