| 摘要 |
1,190,540. Hydroxyethyl terephthalate. NIPPON SODA K.K. 23 Oct., 1968 [23 Oct., 1967], No. 50383/68. Heading C2C. Bis (#-hydroxyethyl) terephthalate is purified by treating an aqueous solution thereof with metallic zinc, tin or magnesium or a mixture thereof at above 40‹ C., and then cooling the solution. The metal may be used together with a salt of the metal. The initial solution may be fully aqueous or may contain an organic solvent. The treatment may be supplemented by treatment with active carbon, which may take place at the same time as the treatment with the metal or during a subsequent recrystallization. Examples are given. |
