US3801547A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid phase polycondensation process
Assignee: EIDP Inc
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Filing: 1972-03-20
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Granted: 1974-04-02
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Expires: 1992-03-20
Abstract
Abstract A PROCESS FOR PREPARING SEGMENTED THERMOPLAASTIC COPOLYSTERS OF SUFFICIENTLY HIFG MOLECULAR WEIGHT SO THAT THE INHERENT VISCOSITY OF THE COPOLYSTER HAVING AN 1;2 MEASURED IN M-CRESOL AT 30*., WHEREIN SOILID TIC ES OF THE PARTIALLY POLYMERIZED COPOLYSTER HAVING AN INHERENT VISCOSITY OF AT LEAST ABOUT 5 TO 20 MESH, ARE HETED TAKE FORM OF GRANUELS OF ABOUT 5 TO 2O MESH, ARE HEATED TO A TEMPERATURE OF ABOT 140-220* C. THE HEATING TAKES PLACE IN AN INERT GAS STREAM OR IN A VACUUM, FOR A PERIOD F 1 TO 72 HOURS.
Inventors
- 👤 G Hoeschele
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:25
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/66; C08G63/668; C08G63/672
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) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |