tetrasodium [mu-[[4,4'-[(3,3'-dihydroxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[3-hydroxynaphthalene-2,7-disulphonato]](8-)]]dicuprate(4-);DirectblueRLL;Directfastblue2RL;Direct Blue 2RL;Cuprate(4-), .mu.-4,4-3,3-di(hydroxy-.kappa.O)1,1-biphenyl-4,4-diylbis
