Patent ID: 8344172

Claim:
A process for making a bis(aryloxyalkyl)terephthalate suitable for use as an antiplasticizer for polymers, comprising the steps of: (a) reacting dimethyl terephthalate with from 1.9 to 3.0 molar equivalents of an aryloxyalkanol in the presence of a condensation catalyst comprising a Group 3, 4, 12, 13, or 15 metal at a temperature less than the boiling point of the aryloxyalkanol to produce an intermediate mixture comprising a bis(aryloxyalkyl)terephthalate, a mono(aryloxyalkyl)terephthalate, and unreacted aryloxyalkanol; (b) continuing to react the intermediate mixture at a temperature within the range of 150° C. to 250° C. under reduced pressure while removing unreacted aryloxyalkanol and reducing the mono(aryloxyalkyl)terephthalate content of the mixture to less than 1 mole % based on the combined amounts of mono- and bis-esters; and (c) removing additional unreacted aryloxyalkanol to provide a purified bis(aryloxyalkyl)terephthalate having an overall purity of at least 98 mole % and a yellowness index less than 10; wherein at least steps (a) and (b) are performed substantially in the absence of oxygen.