METHOD FOR PRODUCING HIGH PURITY GLYCOLIC ACID CRYSTALS

摘要

A method for producing high purity glycolic acid crystals, which comprises the steps of: (1) providing an aqueous glycolic acid solution (A) which has (a) a water content of from 5 to 20% by weight, (b) a calculated monomeric glycolic acid weight ratio (ratio of the total weight of the monomeric glycolic acid and the component monomeric glycolic acid of the glycolic acid condensation product to the weight of the aqueous glycolic acid solution (A)) of from 0.60 to 1.00 and (c) a monomeric glycolic acid content of from 20 to 57% by weight; (2) depositing glycolic acid crystals from the solution (A); and (3) separating the deposited glycolic acid crystals from the solution (A).