US3590070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recycle of terephthalic acid in the production of a bis(2-hydroxyalkyl) terephthalate
Assignee: Celanese Corp
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Filing: 1968-06-03
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Granted: 1971-06-29
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Expires: 1988-06-03
Abstract
Abstract A PROCESS FOR REACTING TEREPHTHALIC ACID WITH AN ALKYLENE OXIDE IN AN INERT HALOHYDROCARBON OR ALKYLBENZENE LIQUID REACTION MEDIUM WHEREIN THE TEREPHTHALIC ACID-CONTAINING WETTED SOLIDS SEPARATED FROM THE REACTION ZONE ARE RECYCLED BY SLURRY THE WETTED SOLIDS IN THE LIQUID REACTION MEDIUM AND PUMPING THEM TO THE REACTION ZONE. IN RECYCLING THE WETTED SOLIDS OF THE SLURRY, CARE MUST BE TAKEN TO AVOID TEMPERATURES OF 90-105*C. IN THE CASE OF AN ALKYLBENZENE LIQUID MEDIUM OR 80 TO 100*C. WHEN USING A HALOHYDROCARBON LIQUID MEDIUM.
Inventors
- 👤 Preston K Martin
- 👤 John P Mireur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:18
CPC Classifications
C; C07; C07C; C07C69/00; C07C69/76; C07C69/80; C07C69/82; C07C67/00; C07C67/24; C07C67/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |