US2739957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of polyethylene terephthalate using an antimony compound as catalyst
Assignee: EIDP Inc
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Filing: 1952-01-03
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Granted: 1956-03-27
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Expires: 1972-01-03
Abstract
No abstract record available.
Inventors
- 👤 Harry R Billica
- 👤 Carriel Jonathan Turner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:59
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/83; C08G63/826; C08G63/84; C08G63/85; C08G63/86; C08G63/866
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
94 words
IN THE PROCESS FOR PRODUCING FILAMENT- AND FILMFORMING POLYETHLENE TERPHTHALATE WHEREIN ETHYLENE GLYCOL IS REACTED UNDER ESTER INTERCHANGE CONDITIONS WITH AN ALKYL ESTER OF TERPHTHALIC ACID AND A SATURATED ALIPHATIC MONOHYDRIC ALCOHOL CONTAINING FROM 1 TO 4 CARBON ATOMS, AND THE RESULTING GLYCOL TEREPHTHALATE IS POLYMERIZED, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE ESTER INTERCHANGE REACTION IN THE PRESENCE OF A CATALYST COMPRISING ESSENTIALLY AT LEAST ONE CALCIUM COMPOUND AND CARRYING OUT THE POLYMERIZATION REACTION IN THE PRESENCE OF A CATALYST CONSISTING OF AT LEAST ONE CALCIUM COMPOUND AND AT LEAST ONE ANTIMONY COMPOUND.
Claim 2
Dependent Claim
94 words
IN THE PROCESS FOR PRODUCING FILAMENT- AND FILMFORMING POLYETHLENE TERPHTHALATE WHEREIN ETHYLENE GLYCOL IS REACTED UNDER ESTER INTERCHANGE CONDITIONS WITH AN ALKYL ESTER OF TERPHTHALIC ACID AND A SATURATED ALIPHATIC MONOHYDRIC ALCOHOL CONTAINING FROM 1 TO 4 CARBON ATOMS, AND THE RESULTING GLYCOL TEREPHTHALATE IS POLYMERIZED, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE ESTER INTERCHANGE REACTION IN THE PRESENCE OF A CATALYST COMPRISING ESSENTIALLY AT LEAST ONE CALCIUM COMPOUND AND CARRYING OUT THE POLYMERIZATION REACTION IN THE PRESENCE OF A CATALYST CONSISTING OF AT LEAST ONE CALCIUM COMPOUND AND AT LEAST ONE ANTIMONY COMPOUND.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-03-27 | 1959-09-26 | 1960-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-03-27 | 1963-09-26 | 1964-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-03-27 | 1967-09-26 | 1968-03-27 | $7700.00 | Window Closed / Lapsed |