2-Naphthalenesulfonic acid, 3,3'-[(3-ethoxy-4,4'-biphenylylene)bis(azo)]bis[6-amino-4-hydroxy-, disodium salt 2-Naphthalenesulfonic acid, 3,3'-[(3-ethoxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[6-amino-4-hydroxy-, disodium salt 6299-38-3 C.I. 24040 Diamine Black BO NSC44654