Patent JPS4954472A successfully refreshed from Google Patents.
US2998412A
Expired / Lapsed
US
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Process for manufacture of polyethylene terephthalate with zinc acetateantimony trifluoride catalyst system
Assignee: Imperial Chemical Industries Ltd
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Filing: 1958-05-12
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Granted: 1961-08-29
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Expires: 1978-05-12
Abstract
No abstract record available.
Inventors
- 👤 Fletcher Norman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:07
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/83; C08G63/85; C08G63/86; C08G63/866
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
THE PROCESS FOR MAKING HIGHLY POLYMERIC POLYETHYLENE TEREPHTHALATE WHICH COMPRISES REACTING ETHYLENE GYCOL AND DIMETHYL TEREPHTHALETE IN A TEMPERATURE OF FROM 150 TO 225*C. IN THE PRESENCE OF ZINC ACETATE IN AMOUNTS BETWEEN 0.01% AND 0.03% BY WEIGHT OF DIMETHYL TEREPHTHLATE AND THEREAFTER POLYCONDENSING THE ETHYLENE GLUCOL TEREPHTHALATE AT A TEMPERATUREW OF FROM 225 TO 285*C. AND PRESSURE FROM 0.02 TO 2 MILLIMETERS OF MERCURY IN THE PRESENCE OF ANTIMONY TRIFLUORIDE IN AMOUNT BETWEEN 0.005% AND 0.04% BY WEIGHT OF DIMETHY TEREPHTHALATE UNTIL A POLYESTER HAVING AN INTRINSIC VISCOSITY OF AT LEAST 0.55 IS OBTAINED.
Claim 2
Dependent Claim
95 words
THE PROCESS FOR MAKING HIGHLY POLYMERIC POLYETHYLENE TEREPHTHALATE WHICH COMPRISES REACTING ETHYLENE GYCOL AND DIMETHYL TEREPHTHALETE IN A TEMPERATURE OF FROM 150 TO 225*C. IN THE PRESENCE OF ZINC ACETATE IN AMOUNTS BETWEEN 0.01% AND 0.03% BY WEIGHT OF DIMETHYL TEREPHTHLATE AND THEREAFTER POLYCONDENSING THE ETHYLENE GLUCOL TEREPHTHALATE AT A TEMPERATUREW OF FROM 225 TO 285*C. AND PRESSURE FROM 0.02 TO 2 MILLIMETERS OF MERCURY IN THE PRESENCE OF ANTIMONY TRIFLUORIDE IN AMOUNT BETWEEN 0.005% AND 0.04% BY WEIGHT OF DIMETHY TEREPHTHALATE UNTIL A POLYESTER HAVING AN INTRINSIC VISCOSITY OF AT LEAST 0.55 IS OBTAINED.
References Cited (Backward Citations)
US2681360A
Cited
US2739957A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-08-28 | 1965-02-27 | 1965-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-28 | 1969-02-27 | 1969-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-28 | 1973-02-27 | 1973-08-29 | $7700.00 | Window Closed / Lapsed |