| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a polycarboxylic acid superior in purity and hue, which does not require to go through a decoloring proccess using much decoloring agent and a plurality of crystallization processes, and is not accompanied with by-product of much ammonium salt. SOLUTION: The method of manufacturing the polycarboxylic acid is characterised in that a polycarboxylic acid ester is obtained by reacting a polynitrile compound having at least two nitrile groups in its molecule, water, and a lower alcohol with each other in the presense of a catalyst, and produced ammonia is removed to the outside of the reaction system, the ester is purified by distillation, and then it is hydrolyzed in the presence of an acid catalyst. COPYRIGHT: (C)2006,JPO&NCIPI
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