abstract |
An object of the present invention is to provide a method for producing high-purity 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (a-BPDA) suitable for polyimide production. SOLUTION: 2,3,3 ′, 4′-biphenyltetracarboxylic acid is dehydrated by heating at 180 to 195 ° C. in an inert gas atmosphere for a time sufficient to complete dehydration. A process for producing a powdery 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride characterized by the following. [Selection figure] None |