Method for producing polyesters containing low amounts of ether by-products
AssigneeThe Goodyear Tire & Rubber Company
InventorsRoy M. Broughton, Joseph R. Thomas, Terence E. Winters
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Abstract
A method for decreasing the amount of ether as a by-product in polyesters (for example terephthalic-based) by initially utilizing a deficient amount of a glycol (for example, ethylene glycol) in the early reaction stages and utilizing an excess of the glycol in the final or end stages. The polyesters produced are of better quality, have a high melting point, possess increased thermal stability, and yield improved fiber properties.
Claims23
A process for reducing the glycol ether content formed during the esterification reaction in making a polyester, comprising the steps of:
- adding to a heel solution in a vessel a dicarboxylic acid selected from the class consisting of alkyl dicarboxylic acids having from 2 to 16 carbon atoms, aryl dicarboxylic acids containing from 8 to about 16 carbon atoms, and alkyl substituted aryl dicarboxylic acids containing from 8 to about 16 carbon atoms;
- conducting an esterification reaction by adding a glycol containing from 2 to 12 carbon atoms and heating said vessel to a temperature of from about 20.degree. C. below the boiling point to about 100.degree. C. above the boiling point of said glycol;
- adding during the initial portion of said esterification reaction a deficient equivalent weight amount of said glycol so that an esterified acid solution having a low ether content is produced;
- and
- retaining a portion of said esterfied acid solution as a heel solution.
A polyester having low glycol ether content produced according to a reaction comprising the steps of:
- adding to a heel solution in a vessel a dicarboxylic acid selected from the class consisting of alkyl dicarboxylic acids having from 2 to 16 carbon atoms, aryl dicarboxylic acids containing from 8 to 16 carbon atoms, and alkyl substituted aryl dicarboxylic acids containing from 8 to about 16 carbon atoms;
- conducting an esterification reaction by adding a glycol containing from 2 to 12 carbon atoms and heating said vessel to a temperature of from about 20.degree. C. below the boiling point to about 100.degree. C. above the boiling point of said glycol;
- adding during the initial esterification reaction a deficient equivalent weight amount of said glycol so that an esterfied acid having a low ether content is produced;
- retaining a portion of said esterfied acid solution as a heel solution;
- removing the remaining portion of said esterfied acid solution;
- and
- condensing said remaining esterfied acid solution by drawing a vacuum and adding a catalyst to produce a polyester having a low ether content.
Dependencies are inferred from the claim text.