USE OF AN ACETIC ACID WASH TO PREPARE LOW-SULFATE 5-SULFOISOPHTHALIC ACID, MONO-LITHIUM SALT

摘要

There is disclosed a process for making a mono-lithium salt of 5-sulfoisophthalic acid (LiSIPA) having less than 500 ppm sulfate. The process uses a reaction mixture of water, a lithium cation producing compound, and 5-sulfoisophthalic acid. The reaction mixture is heated to reflux, cooled, filtered and washed with acetic acid to obtain a high quality LiSIPA having less than 500 ppm sulfate. Also disclosed is a high quality, non-purified reaction product containing a mono-lithium salt of 5-sulfoisophthalic acid and having less than 500 ppm sulfate.