| 摘要 |
An aromatic polyester is pre-decomposed by heating together with bis- .beta.-hydroxyethyl terephthalate and/or a low condensate thereof and then, reacted with ethylene glycol to convert the terephthalic acid component of the pre-decomposed product into bis- .beta.-hydroxyethyl terephthalate and/or a low condensate thereof. The thus obtained solution composition, that is, bis- .beta.-hydroxyethyl terephthalate solution composition containing ethylene glycol, bis- .beta.-hydroxyethyl terephthalate and cations and/or anions as impurities is brought into contact with a cation exchanger and/or an anion exchanger to remove rations and anions as impurities to produce bis- .beta.-hydroxyethyl terephthalate having a small content of ions. The bis- .beta.-hydroxyethyl terephthalate-containing mixture having a small content of ions is subjected to preliminary evaporation or distillation to distill off a compound having a boiling point lower than that of bis- .beta.-hydroxyethyl terephthalate and then, to evaporation or distillation under reduced pressure to give purified bis-(3-hydroxyethyl terephthalate. Thus, purified bis- .beta.-hydroxyethyl terephthalate having a ration and anion total content of 15 ppm or less is obtained.
|
