METHOD FOR PRODUCING HIGH PURITY BIPHENYLTETRACARBOXYLIC ACID DIANHYDRIDE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a high purity biphenyltetracarboxylic acid dianhydride having an trace amount of content of insoluble fine particles as an impurity. SOLUTION: This method for recovering the high purity biphenyltetracarboxylic acid dianhydride containing≤2×103insoluble fine particles having 5-30μm size per 1 g is provided by performing a dehydration and ring-closure reaction of biphenyltetracarboxylic acid containing≤7×104insoluble fine particles having 5-30μm size per 1 g to form the biphenyltetracarboxylic acid dianhydride, heating under a reduced pressure for evaporating and then cooling the evaporated portion. COPYRIGHT: (C)2003,JPO