US3634359A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of high-molecular weight polyesters
Assignee: Hoechst AG
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Filing: 1969-10-15
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Granted: 1972-01-11
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Expires: 1989-10-15
Abstract
Abstract HIGH-MOLECULAR WEIGHT POLYESTERS ARE OBTAINED FROM LOW-MOLECULAR WEIGHT POLYESTERS BY AFTER-CONDENSATION IN THE SOLID PHASE. HIGH-FREQUENCY IS USED FOR HEATING UP THE POLYESTER TO THE AFTER-CONDENSATION TEMPERATURE. DURING HEATING CRYSTALLIZATION AND SUBSTANTIAL DRYING SHOULD TAKE PLACE.
Inventors
- 👤 Siegfried Breitschaft
- 👤 Rolf Holtermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:58
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/80
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |