Patent ID: 6710202
Filing Date: 2004-03-23
Classification: C07C

Abstract:
A process for producing high-purity bis-&bgr;-hydroxyethyl terephthalate by carrying out the following steps (1) to (4) in the mentioned order:(1) the step of esterifying crude terephthalic acid with ethylene glycol and/or ethylene oxide to form a reaction product containing bis-&bgr;-hydroxyethyl terephthalate; (2) the step of preparing a solution containing bis-&bgr;-hydroxyethyl terephthalate as the main solute and ethylene glycol as the main solvent by mixing the above reaction product obtained in the above step (1) with ethylene glycol as required and deionizing the solution to form a deionized solution of bis-&bgr;-hydroxyethyl terephthalate; (3) the step of distilling off substances having a boiling point lower than that of bis-&bgr;-hydroxyethyl terephthalate from the above deionized solution obtained in the step (2) to form crude bis-&bgr;-hydroxyethyl terephthalate; and (4) the step of subjecting the crude bis-&bgr;-hydroxyethyl terephthalate obtained in the step (3) to molecular distillation to distill out bis-&bgr;-hydroxyethyl terephthalate.