Process for production of isophthalic acid

摘要

A method for producing isophthalic acid, comprising: subjecting a m-phenylene compound and a molecular-oxygen-containing gas to liquid-phase oxidation reaction in the presence of a catalyst comprising a heavy metal compound and a bromine compound, and hydrous acetic acid having a water content of 1 to 15 mass %, to thereby yield a slurry; regulating the temperature of the slurry to 35 to 140° C., to thereby precipitate isophthalic acid; removing the isophthalic acid through solid-liquid separation, to thereby recover a mother liquor; and recovering the catalyst from the mother liquor by following steps (1) to (4) as described.