US3709859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the production of polyesters with a novel multicomponent catalyst
Assignee: Individual
•
Filing: 1971-08-18
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Granted: 1973-01-09
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Expires: 1991-08-18
Abstract
Abstract POLYESTERS, SUCH AS POLYETHYLENE TEREPHTHALARE ARE PREPARED BY HEATING A DICARBOXYLIC ACID ESTER, SUCH AS DIMETHYL TEREPHTHALATE, WITH AN ALIPHATIC OR CYCLIC DIOL SUCH AS ETHYLENE GLYCOL, TO A TEMPERATUREE IN THE ORDER OF 100*C.-360*C. IN THE PRESENCE OF A CATALYST CONTAINING (A) ANTIMONY, (B) LEAD AND (C) CALCIUM STRONTIUM OR BARIUM. THE CATALYST IS PREFERABLY A MIXTURE OF FINELY DIVIDED METALS OR ALLOYS. THE PRODUCTS ARE CHARACTERIZED BY A LIGHT COLOR AND EXCELLENT COLOR AND HEAT STABILITY.
Inventors
- 👤 J Hrach
- 👤 T Wimmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:05
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/85; B; B01; B01J; B01J21/00; B01J23/00; B01J23/14; B01J23/16; B01J23/18; C08G63/83
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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |