Patent US3694490A successfully refreshed from Google Patents.
US3694490A
Expired / Lapsed
US
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Production of phenolic esters of aromatic acids
Assignee: Celanese Corp
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Filing: 1969-11-18
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Granted: 1972-09-26
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Expires: 1989-11-18
Abstract
Abstract Process for the esterification of aromatic carboxylic acids with monatomic phenols comprising heating in the liquid phase to a temperature above 275* C. a mixture of the aromatic carboxylic acid with the monoatomic phenol. Catalysts are not necessary but acidic catalysts such as phosphoric acid may be utilized if desired. The esters are monomers that can be used to prepare several types of high performance polymers.
Inventors
- 👤 Enrique Roberto Witt
- 👤 James Patrick Cave
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:20
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
14 words
A process according to claim 1 wherein the temperature is from 275*C to 400*C.
Claim 2
Dependent Claim
32 words
The process of claim 1 wherein the amount of phenol that is utilized is such that there is at least a 10 percent excess over that to be utilized in the reaction.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein said monoatomic phenol is phenol and wherein said carboxylic acid is terephthalic acid, isophthalic acid or mixtures thereof, and wherein the diphenyl ester is produced and recovered.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein water is removed during the esterification.
Claim 5
Dependent Claim
65 words
The process for producing a diphenyl ester of a phthalic acid comprising heating in the absence of the catalyst and in the liquid phase to a temperature of 250* to 400*C and for a period of at least 5 minutes a mixture of said phthalic acid and phenol whereby a diphenyl ester of the phthalic acid is produced followed by recovery of the diphenyl ester.
Claim 6
Dependent Claim
12 words
The process of claim 6 wherein water is removed during said heating.
Claim 7
Dependent Claim
26 words
The process of claim 7 wherein the amount of pheNol utilized is at least a 10 percent excess over that to be utilized in the reaction.
Claim 8
Dependent Claim
12 words
The process of claim 8 wherein said phthalic acid is terephthalic acid.
Claim 9
Dependent Claim
12 words
The process of claim 9 wherein said phthalic acid is isophthalic acid.
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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |