| 摘要 |
1,143,072. Purifying di-(hydroxyalkyl) terephthalates. IMPERIAL CHEMICAL INDUSTRIES Ltd. 10 Jan., 1967 [24 Jan., 1966], No. 3099/66. Heading C2C. Di-(hydroxyalkyl) terephthalates are purified by contacting their solutions in water, a nitrile, a ketone, an ether or an alkyl ester of an aliphatic carboxylic acid with an adsorbent, and then crystallizing the purified products. The adsorbent may be, e.g., an active earth, alumina, silica/alumina, a molecular sieve, an ion exchange resin or active carbon, and the process is preferably applied to the purification of bis-(2- hydroxyethyl) terephthalate obtained by reacting terephthalic acid with ethylene oxide. |
