US3640937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear segmented polyurethane elastomers
Assignee: Bayer AG
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Filing: 1969-06-03
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Granted: 1972-02-08
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Expires: 1989-06-03
Abstract
Abstract THIS INVENTION RELATES TO HIGHLY ELASTIC LINEAR SEGMENTED POLYURETHANES COMPRISING SEGMENTS OBTAINED FROM CERTAIN SEMI-CARBAZIDE HYDRAZIDES CHAIN EXTENDING AGENTS, HIGHLY ELASTIC FIBRES THEREOF AND TO A PROCESS FOR THE PREPARATION OF SAID LINEAR, SEGMENTED POLYURETHANE ELASTOMERS.
Inventors
- 👤 Wilhelm Thoma
- 👤 Bergisch Neukirchen
- 👤 Harald Oertel
- 👤 Heinrich Rinke
- 👤 Ulrich Bahr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:03
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; C07; C07F; C07F9/00; C07F9/02; C07F9/547; C07F9/6515; C07F9/6521; C08G18/12
Claims Analysis
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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) | 1975-02-07 | 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 |