Synonyms: 1,3-Isobenzofurandione, 5,5'-[[1,1'-biphenyl]-4,4'-diylbis(oxy)]bis-, Phthalic anhydride, 4,4'-(4,4'-biphenylylenedioxy)di- (8CI); 5,5'-[[1,1'-Biphenyl]-4,4'-diylbis(oxy)]bis[1,3-isobenzofurandione]; 4,4'-(4,4'-Biphenylenedioxy)diphthalic anhydride; 4,4'-Bis(3,4-dicarboxyphenoxy)biphenyl dianhydride