US3557044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making spandex polymers
Assignee: EIDP Inc
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Filing: 1967-06-09
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Granted: 1971-01-19
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Expires: 1987-06-09
Abstract
Abstract SPANDEX POLYMERS WHICH HAVE LOW INTRINSIC VISCOSITIES AND WHICH CAN THUS BE SPUN FROM SOLUTIONS AT HIGH SOLIDS CONCENTRATIONS, BYT WHICH RESULT IN YARNS HAVING HIGH INTRINSIC VISCOSITIES AND COREESPONDINGLY GOOD PHYSICAL PROPERTIES CAN BE PRODUCED. AN AROMATIC DIISOCYANATE IS REACTED WITH A DIFUNCTIONAL HYDROXYL- OR AMINE-TERMINATED LINEAR ORGANIC POLYMER AND THE RESULTING ISOCYANATE-TERMINATED MACROINTERMEDIATE IS CHAIN-EXTENDED WITH A DIAMINE, HYDRAZINE OR DIHYDRAZIDE. A NONAROMATIC SECONDARY MONOAMINE, WHICH ACTS AS A CHAIN-TERMINATOR, IS ALSO USED, AND THE AMOUNTS OF CHAIN-TERMINATOR AND CHAIN-EXTENDER ARE SELECTED FROM WITHIN SPECIFIED SPECIFIED LIMITS.
Inventors
- 👤 James L Bleasdale
- 👤 Carl L Sandquist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:26
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |