PROCESS FOR PRODUCING ISOPHTHALIC ACID

摘要

A process is claimed for the prodn. of isophthalic acid by air oxidn. of meta-xylene at 190-205 deg.C and 1.9-2.3 MPa pressure in an aq. soln. of acetic acid in the presence of a catalyst comprising a mixt. of Co and Mn acetates in mol. ratio 2:1 to 5:1 together with a bromo compound (e.g. NaBr) as co-catalyst. The mol. ratios of meta-xylene:water:total Co + Mn content lie in the range 1.0 to 1.75:1.0 to 2.5:(1.0 to 1.2) x 10 power -2. - The process facilitates prepn. of isophthalic acid in a single step with apparatus requiring only moderate (up to 2.3 MPa) pressure and enables a high throughput (265 to 420 g/l.h) to be achieved.