US3804812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing a segmented linear polyurethane polymer
Assignee: Wyeth Holdings LLC
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Filing: 1972-11-03
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Granted: 1974-04-16
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Expires: 1992-11-03
Abstract
Abstract AN IMPROVED PROCESS FOR PREAPRING A SEGMENTED LINEAR POLYURETHANE POLYMER IS PROVIDED WHICH CONSISTS OF PREPARING A PREPOLYMER BY REACTINF POLYTETRAMETHYLENE ETHER GLYCOL WITH METHYLENEBIS(4-PHENYL-ISOCYANATE) AND CHAIN EXTENDING THE RESULTING ISOCYANATE TERMINATED PREPOLYMER IN SOLUTION, WITH A SUITABLE ALIPHATIC DIAMINE OR A GLYCOL, THE IMPROVEMENT WHICH COMPRISES EMPLOYING A POLYTETRAMETHYLENE ETHER GLYCOL HAVING A MOLECULAR WEIGHT BETWEEN 2500 AND 7500. IN ADDITION, THE INVENTION ALSO PROVIDES AN IMPROVED SPANDEX FIBER PREPARED FROM SUCH SEGMENTED LINEAR POLYURETHANE POLYMER.
Inventors
- 👤 A Koroscil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:41
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/4854; C08G18/08; C08G18/10
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) | 1977-04-15 | 1977-10-15 | 1978-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-15 | 1981-10-15 | 1982-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-15 | 1985-10-15 | 1986-04-16 | $7700.00 | Window Closed / Lapsed |