Process for producing highly pure isophthalic acid

• Main Authors: OHTA, TAZUO, MITSUBISHI GAS ICAL COMPANY, INC, YOSHIDA, TERUMASA, MIZUSHIMA FACTORY OF MITSUBISHI, OHGOSHI, FUMIO, MIZUSHIMA FACTORY OF MITSUBISHI, TANAKA, KAZUO, MIZUSHIMA FACTORY OF MITSUBISHI, MOTOYAMA, ICHIHEI, MIZUSHIMA FACTORY OF MITSUBISHI
• Format: Patent
• Language: English; French; German
• Published: 07.12.1994
• Edition: 5
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; GENERAL METHODS OF ORGANIC CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR RELEVANT APPARATUS; TRANSPORTING

A process for producing highly pure isophthalic acid which comprises (a) carrying out liquid phase oxidation of an m-dialkyl benzene with molecular oxygen in an acetic acid solvent in the presence of a heavy metal catalyst to form crude isophthalic acid, (b) contact-treating the resulting crude isophthalic acid with a noble metal catalyst belonging to the Group VIII of the Periodic Table supported by activated carbon in the presence of hydrogen, and then (c) separating the deposited isophthalic acid crystal and (d) filtration-treating the separated mother liquor and (e) recirculating the mother liquor thus treated into the liquid phase oxidation step (a) for reusing as a solvent in step (a) is disclosed.