US3657191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the modification of terminal groups of polyesters
Assignee: Hoechst AG
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Filing: 1970-06-09
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Granted: 1972-04-18
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Expires: 1990-06-09
Abstract
Abstract THE PRESENT INVENTION RELATES TO A PROCESS FOR THE MANUFACTURE OF LINEAR POLYESTERS HAVING AN IMPROVED STABILITY WITH RESPECT TO COMPOUNDS WITH ACTIVE HYDROGEN. POLYESTERS OF THIS TYPE ARE OBTAINED BY REACTING POLYESTERS WITH ETHYLENE CARBONATES OR MONOFUNCTIONAL GLYCIDYL ETHERS. THE REACTION IS FIRST CARRIED OUT WITHIN A TEMPERATURE RANGE LYING 10* TO 60*C. BELOW THE SOFTENING POINT OF THE POLYESTER AND IS THEN TERMINATED DURING THE MELTING- AND MELTSPINNING PROCESS.
Inventors
- 👤 Rudolf Titzmann
- 👤 Hella Titzmann
- 👤 Klaus Titzmann
- 👤 Jorg Titzmann
- 👤 Michael Titzmann
- 👤 Hans Thaler
- 👤 Josef Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:12
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/40; C08G63/42; D; D01; D01F; D01F6/00; D01F6/58; D01F6/62; D01F6/78; D01F6/84
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |