Patent ID: 7842824

Claim:
A process for producing biphenyltetracarboxylic acid dianhydride, which comprises heating 3, 4, 3′, 4′ biphenyltetracarboxylic acid to produce 3, 4, 3′, 4′ biphenyltetracarboxylic acid dianhydride, characterized in that the heating is carried out at a pressure of from 1×10 2 Pa to 1.1×10 5 Pa to a maximum temperature in a range of from 210° C. to 250° C. in such a manner that the temperature rising rate is higher than 50° C./hr for a period of at least ¼ of the time for the temperature rise from 60° C. to 210° C., and the temperature is maintained to be from 150° C. to 250° C. for from 0.5 to 10 hours.