BIPHENYLTETRACARBOXYLIC ACID DIANHYDRIDE

PROBLEM TO BE SOLVED: To obtain the subject compound useful for the production of a high molecular weight aromatic polyamic acid by dehydrating a biphenyltetracarboxylic acid under a specific heating condition for reducing the contaminating amount of biphenyltricarboxylic acid as less than a specific amount. SOLUTION: This method for producing a biphenyltetracarboxylic acid anhydride is provided by performing a heating so that the mean temperature- elevating rate during the pre-heat-treatment for elevating temperature from 80 deg.C to its dehydrating temperature does not become higher than 50 deg.C/hr for removing attached water to the above crystal and crystal water in dehydrating a crystal of a biphenyltetracarboxylic acid under an inert gas atmosphere (under a normal pressure or reduced pressure) by heating at a dehydrating temperature of >=250 deg.C, then heat-treating the pre-treated crystal at the dehydrating temperature of 250-300 deg.C for at least 3 hr for dehydration to obtain the biphenyltetracarboxylic acid anhydride containing >0.15 wt.% contaminating biphenyltricarboxylic acid and its anhydride.