Claims
- 1. A process for the production of esters which consists essentially of reacting a mixture of a polycarboxylic acid and an alcohol in the presence or absence of a catalyst which is insoluble in the mixture, distilling off unreacted alcohol from the esterification reaction mixture obtained to give a crude ester, heat-treating said crude ester at a temperature of 160.degree.-340.degree. C. for 0.1-3 hours, contacting said heat-treated ester with an adsorbent at a temperature of 30.degree.-150.degree. C. and then separating and recovering the desired ester from the crude ester.
- 2. The process of claim 1 wherein the heat-treatment is carried out under reduced pressure to distill off the free polycarboxylic acid resulting from the heat-treatment.
- 3. The process of claim 1 wherein the heat-treatment is carried out in an atmosphere of an inert gas.
- 4. The process of claim 1 wherein the adsorption treatment is carried out using an adsorbent selected from the group consisting of sodium oxide, magnesium oxide, aluminum oxide, silicon oxide, iron oxide, calcium oxide, aluminum hydroxide, magnesium hydroxide, sodium carbonate, sodium bicarbonate, aluminum carbonate, magnesium carbonate, and mixtures of these.
- 5. The process of claim 1 wherein the adsorption treatment is carried out using an absorbent in an amount of not more than 1/20 of the weight of the heat-treated ester.
- 6. The process of claim 1 wherein the alcohol is an aliphatic or alicyclic monohydric alcohol containing 1 to 13 carbon atoms.
- 7. The process of claim 1 wherein the polycarboxylic acid is an aromatic polycarboxylic acid, an aliphatic polycarboxylic acid, or an anhydride of any of these polycarboxylic acids.
- 8. The process of claim 1 wherein the residue left after the separation of the final ester is incinerated.
- 9. The process of claim 8 wherein the incineration temperature is 400.degree. to 900.degree. C.
- 10. The process of claim 8 wherein the residual ash obtained by the incineration is re-used as the adsorbent and/or the esterification catalyst.
- 11. A process for the production of esters which consists essentially of reacting a mixture of a polycarboxylic acid and an alcohol in the presence or absence of a catalyst which is insoluble in the mixture, distilling off unreacted alcohol from the esterification reaction mixture to give a crude ester, heat-treating said crude ester at a temperature of 160.degree.-340.degree. C. for 0.1-3 hours, then contacting said heat-treated ester with an adsorbent at a temperature of 30.degree.-150.degree. C., then separating and recovering the intended ester from the crude ester, thereby forming a residue, incinerating the residue to form ash, and reusing the ash thus obtained as adsorbent and/or esterification catalyst.
Priority Claims (2)
Number |
Date |
Country |
Kind |
51-3033 |
Jan 1976 |
JPX |
|
51-8987 |
Jan 1976 |
JPX |
|
Parent Case Info
This application is a continuation-in-part application of U.S. Ser. No. 756,605 filed on Jan. 4, 1977, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (2)
Number |
Date |
Country |
2042402 |
Mar 1972 |
DEX |
329167 |
Mar 1972 |
SUX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
756605 |
Jan 1977 |
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