| 摘要 |
PROBLEM TO BE SOLVED: To prevent the precipitation of bishydroxyethyl terephthalate or bishydroxybutyl terephthalate (BHET, etc.), in purging step in a purification process of crude BHET, etc., with activated carbon and ion exchange resin. SOLUTION: A bishydroxyalkyl terephthalate is purified by passing crude bishydroxyalkyl terephthalate through a treating column comprising a combination of an activated carbon column and an ion exchange resin column. In the above process, ethylene glycol or an alcohol is used as a purging solvent in the purging process after passing the compound through each column.
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