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.

主权项

1. A process for the preparation of a salt of 5-sulfoisophthalic acid, the method comprising the steps of:
forming a mixture comprising acetic acid, water, a quantity of a lithium cation producing compound, and a quantity of 5-sulfoisophthalic acid; and heating the mixture comprising acetic acid, water, a lithium cation producing compound and 5-sulfoisophthalic acid at a sufficient temperature for a sufficient period of time to produce a mixture containing a 5-sulfoisophthalic acid, mono-lithium salt.