METHOD FOR PREPARING PURIFIED TEREPHTHALIC AND ISOPHTHALIC ACID FROM XYLENES MIXTURE Russian patent published in 2003 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to the improved method for preparing terephthalic and isophthalic acids. In part, invention relates to method for purification of crude terephthalic from liquid dispersion containing terephthalic and isophthalic acid synthesizing as result of oxidation of xylenes mixture. Invention relates also to method for purification of crude terephthalic acid and isophthalic acid from liquid dispersion containing terephthalic, isophthalic acids and other impurities synthesizing as result of oxidation of xylenes mixture. Terephthalic and isophthalic acids can be used for preparing fibers, films, plastic bottles and structures of polyester resins fortified by other material often, such as fiber glass. Method provides separation of terephthalic acid from its isomers, for example, from isophthalic acid and to obtain purified terephthalic and isophthalic acids in a single process. EFFECT: improved preparing method. 23 cl, 3 tbl, 5 dwg, 4 ex