73909-19-0 BRN 2066479 Benzoic acid, 4-methyl-, dianhydride with 1,2-ethenediylbis(carbamic acid) Carbamic acid, N,N'-vinylenedi-, dianhydride with bis(p-toluic acid) N,N'-Vinylenebis(p-toluic acid carbamic acid anhydride) p-Toluic acid, dianhydride with N,N'-vinylene dicarbamic acid