4,4-Carbonyldiphthalic anhydride; BTDA~4,4-Carbonyldiphthalic anhydride; benzophenone-3,3:4,4-tetracarboxylic dianhydride; BTDA; 3,3,4,4-Benzophenontetracarbonsaeuredianhydrid,; Benzophenone-3,3?4,4?tetracarboxylic dianhydride; 1,3-Isobenzofurandione, 5,5'-carbonylbis-; 3,3',4,4'-Benzophenonetetracarboxylic acid dianhydride; 3,3',4,4'-Tetracarboxybenzophenone dianhydride; 3,3’,4,4’-benzophenonetetracarboxylicaciddianhydride; 3-Isobenzofurandione,5,5’-carbonylbis-1; 4,4'-Carbonylbis[phthalic anhydride]; 4,4'-Diphthalic anhydride ketone; 5,5’-carbonylbis-3-isobenzofurandione