US3220982A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of spinnable polyesters using thallium catalysts
Assignee: HJ Zimmer Verfahrenstechnik
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Filing: 1962-08-23
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Granted: 1965-11-30
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Expires: 1982-08-23
Abstract
No abstract record available.
Inventors
- 👤 Advani Ram
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:42
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/84
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
69 words
IN A PROCESS FOR PRODUCING SPINNABLE POLYESTERS BY TRANSESTERIFICATION OF DEIMETHYL TEREPHTHALATE WITH ETHYLENE GLYCOL TO FORM THE ETHYLENE GLYCOL DIESTER OF TEREPHTHALIC ACID FOLLOWED BY POLYCONDENSATION OF SAID ETHYLENE GLYCOL DIESTER OF TEREPHTHALIC ACID, THE IMPROVEMENT WHICH COMPRISES REACTING SAID DIMETHYL TEREPHTHALATE WITH ETHYLENE GLYCOL IN THE PRESENCE OF A CATALYTIC AMOUNT OF A THALLIUM COMPOUND SOLUBLE IN A LEAST ONE OF SAID DIMETHYL TEREPHTHALATE AND ETHYLENE GLYCOL.
Claim 2
Dependent Claim
69 words
IN A PROCESS FOR PRODUCING SPINNABLE POLYESTERS BY TRANSESTERIFICATION OF DEIMETHYL TEREPHTHALATE WITH ETHYLENE GLYCOL TO FORM THE ETHYLENE GLYCOL DIESTER OF TEREPHTHALIC ACID FOLLOWED BY POLYCONDENSATION OF SAID ETHYLENE GLYCOL DIESTER OF TEREPHTHALIC ACID, THE IMPROVEMENT WHICH COMPRISES REACTING SAID DIMETHYL TEREPHTHALATE WITH ETHYLENE GLYCOL IN THE PRESENCE OF A CATALYTIC AMOUNT OF A THALLIUM COMPOUND SOLUBLE IN A LEAST ONE OF SAID DIMETHYL TEREPHTHALATE AND ETHYLENE GLYCOL.
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) | 1968-11-29 | 1969-05-31 | 1969-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-29 | 1973-05-31 | 1973-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-29 | 1977-05-31 | 1977-11-30 | $7700.00 | Window Closed / Lapsed |