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US 4,066,627 AGranted
Production of polyesters
AssigneeGeneral Electric Company
InventorsWillem F. H. Borman, Eugene P. Reilly
Life of this patent
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Abstract
Poly(alkylene terephthalates) are prepared by an improved process which provides high molecular weight, in a shortened reaction time, without excessive loss of the diol reactant to side reactions. In the process an excess of the diol reactant is heated with a mixture of the corresponding dialkyl terephthalate and from 5 to 95 mole % of terephthalic acid, based on the mixture.
Claims7
A process for the preparation of a linear poly(1,4-butylene terephthalate) resin, said process comprising:
- a. heating at a temperature in the range of from about 150.degree. to about 300.degree. C. a reaction mixture comprising an excess of 1,4-butanediol, dimethyl terephthalate and terephthalic acid, the proportions of the reactants satisfying the following equation:
- ##EQU4## wherein TA is the terephthalate mixture, DAT is dimethyl terephthalate and TAP is terephthalic acid;
- and
- b. removing the excess 1,4-butanediol and methanol and water byproducts until a high molecular weight resin is formed.
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A process for the preparation of a linear poly(1,4-butylene terephthalate) resin, said process comprising:
- a. heating at a temperature of from about 150.degree. to about 300.degree. C. a mixture of dimethyl terephthalate and from about 5 to about 25 mole % of terephthalic acid based on said mixture and from about 125 to about 200 mole percent, based on said mixture, of 1,4-butanediol until methanol and water substantially cease to be evolved;
- b. applying a vacuum and continuing the heating until the excess 1,4-butanediol substantially ceases to be evolved;
- and
- c. continuing the heating under vacuum and removing byproduct 1,4-butanediol until a high molecular weight resin is formed.
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Dependencies are inferred from the claim text.