US3655729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing esters of terephthalic acid
Assignee: Aerojet Rocketdyne Holdings Inc
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Filing: 1968-07-18
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Granted: 1972-04-11
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Expires: 1988-07-18
Abstract
Abstract THE INVENTION RELATES TO THE PREPARATION OF POLYESTERS FROM TEREPHTHALIC ACID AND GLYCOL USING A FLUID MIXTURE OF GLYCOL AND TEREPHTHALIC ACID AS STARTING MATERIAL. THE FLUID MIXTURES CONTAIN GLYCOL TO TEREPHTHALIC ACID IN MOLAR RATIOS OF FROM ABOUT 0.9:1 TO 1,3:1, THE TEREPHTHALIC ACID BEING A MIXTURE OF PARTICLES OF DIFFERENT SIZES.
Inventors
- 👤 Verne R Rinehart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:15
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C07; C07C; C07C67/00; C07C67/08
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) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |