Transesterification process for preparation of linear polyesters
AssigneeHooker Chemicals & Plastics Corporation
InventorsGideon Salee, Jerold C. Rosenfeld
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Abstract
An improved transesterification process for preparation of a linear aromatic polyester comprising bisphenol and dicarboxylic acid monomer units terminated with a carboxylic acid ester groups derived from a long chain aliphatic monofunctional alcohol comprises as the improvement partially transesterifying a diaryl ester of the dicarboxylic acid with the alcohol prior to carrying out the transesterification polymerization reaction of said aryl ester and the bisphenol.
Claims17
In the process of preparing a linear aromatic polyester by the transesterification polymerization reaction of a mixture of a bisphenol and a diaryl ester of a dicarboxylic acid wherein the molar proportion of the bisphenol and the diaryl ester ranges from about 5 molar percent insufficiency of the diaryl ester over the stoichiometric equivalent proportion of the bisphenol and the diaryl-ester to an excess of the diaryl ester over said stoichiometric proportion, the improvement wherein the diaryl ester is mixed with and transesterified with a minor molar proportion of a saturated aliphatic hydrocarbon monofunctional alcohol of 8 to 45 carbon atoms prior to any reaction of the bisphenol reactant and the diaryl ester reactant, said proportion of the alcohol being based on the molar amount of the diaryl ester reactant employed in the polymerization reactant.
In the process of preparing a linear aromatic polyester by the transesterification polymerization reaction of a mixture of about stoichiometric equivalent proportions of a bisphenol and a diphenyl ester of an aromatic dicarboxylic acid, the improvement wherein the diphenyl ester is transesterified at a temperature of about 100.degree. to 300.degree. under sub-atmospheric pressure with about 0.1 mole percent to about 25 mole percent of an aliphatic monofunctional saturated alcohol of 9 to 40 carbon atoms, based on the molar amount of the diphenyl ester reactant, prior to the addition of the bisphenol to said mixture, said transesterification reaction of the alcohol and the diphenyl ester and said transesterification polymerization reaction being carried out in the presence of about 0.005% to about 2% of a transesterification catalyst based on the combined weight of the bisphenol and the diphenyl ester to recover a linear aromatic polyester of said bisphenol and said dicarboxylic acid which contains at least about 5 mole percent of a terminal carboxylate ester group derived from the organic radical of said alcohol based on the total moles of end groups in the polyester.
Dependencies are inferred from the claim text.