A METHOD FOR PREPARING HYDROXYCARBOXYLIC ACID OR DIMER THEREOF AND A METHOD FOR PREPARINGα,β-UNSATURATED CARBOXYLIC ACID

摘要

He present invention relates to a method for preparing hydroxy carboxylic acid or a dimer thereof from a raw material including hydroxy carboxylic acid salt, and to a method for preparingα,β-unsaturated carboxylic acid by using the hydroxy carboxylic acid or the dimer thereof prepared by the method. The preparation method comprises the steps of: preparing a hydroxy carboxylic acid salt-containing raw material; reacting the hydroxy carboxylic acid salt-containing raw material with an inorganic acid in the presence of non-amine or non-alcohol organic solvent, and generating a hydroxy carboxylic acid-containing non-aqueous solution and inorganic acid salt; and removing the inorganic acid.