USE OF AN ACETIC ACID/WATER SOLVENT MIXTURE FOR THE PREPARATION OF LOW-SULFATE 5-SULFOISOPHTHALIC ACID, MONO-LITHIUM SALT FROM 5-SULFOISOPHTHALIC ACID.

摘要

There is disclosed a process for making a mono-lithium salt of 5-sulfoisophthalic acid (LiSIPA) having less than 200 ppm sulfate. The process uses a reaction mixture of acetic acid, water, a lithium cation producing compound, and 5-sulfoisophthalic acid. The reaction mixture is heated to reflux, cooled, filtered and washed to obtain a high quality LiSIPA having less than 200 ppm sulfate. Also disclosed is a high quality mono-lithium salt of 5-sulfoisophthalic acid having less than 200 ppm sulfate.