US3658746A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Segmented polyurethane elastomers
Assignee: Bayer AG
•
Filing: 1970-01-08
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Granted: 1972-04-25
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Expires: 1990-01-08
Abstract
Abstract THE OBJECTS OF THE INVENTION ARE SEGMENTED POLYURETHANE ELASTOMERS, PREFERABLY ELASTOMERIC FIBERS, FOILS AND SOLUTIONS THEREOF, BEING PREPARED BY REACITING AN NCOPOLYMER WITH A SEMICARTBAZIDE-ALKYL-AMINE OR -ARYLAMINE AS CHAIN EXTEDNDING AGENTS-UP TO 45 MOL PERCENT OF THE TOTAL AMOUNT OF CHAIN EXTENDERS-CAN BE USED. THE REACTION IS EFFECTED IN HIGHLY POLAR SOLVENTS. THE OBTAINED ELASTOMERS HAVE IMPROVED PROPERTIES, ESPECIALLY IMPROVED HEAT DISTORTION TEMPERATURE AND IMPROVED HYDROTHERMAL PROPERTIES. A FURTHER OBJECT OF THE INVENTION ARE NEW SEMICARBAZIDE AMINO COMPOUNDS.
Inventors
- 👤 Friedrich Karl Rosendahl
- 👤 Harald Oertel
- 👤 Heinrich Rinke
- 👤 Wilhelm Thoma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:21
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |