Also Called: Disodium;(6E)-4-amino-3-[[4-[4-[(2,4-diamino-5-methylphenyl)diazenyl]phenyl]phenyl]diazenyl]-5-oxo-6-(phenylhydrazinylidene)naphthalene-2,7-disulfonate;C.I. Direct black 4, disodium salt;Disodium 4-amino-3-[[4'-[(2,4-diamino-5-methylphenyl)azo][1,1'-biphenyl]-4-yl]azo]-5-hydroxy-6-(phenylazo)naphthalene-2,7-disulphonate;2,7-Naphthalenedisulfonic acid, 4-amino-3-[2-[4'-[2-(2,4-diamino-5-methylphenyl)diazenyl][1,1'-biphenyl]-4-yl]diazenyl]-5-hydroxy-6-(2-phenyldiazenyl)-, sodium salt (1:2);C.I. Direct black 4;disodium salt;C.I. Direct Black 4, C.I.30245;2,7-NAPHTHALENEDISULFONIC ACID, 4-AMINO-3-[[4'-[(2,4-DIAMINO-5-METHYLPHENYL)AZO][1,1'-BIPHENYL]-4-YL]AZO]-5-HYDROXY-6-(PHENYLAZO)-, DISODIUM SALT;2,7-NAPHTHALENEDISULFONIC ACID,4-AMINO-3-[[4'-[(2,4-DIAMINO-5-METHYLPHENYL)AZO][1,1'-BIPHENYL]-4-YL]AZO]-5-HYDROXY-6-(PHENYLAZO)-, DISODIUM SALT;DIRECT BLACK 4;2,7-NAPHTHALENEDISULFONIC ACID, 4-AMINO-3-[[4'-[(2,4-DIAMINO-5-METHYLPHENYL)AZO] [1,1'-BIPHENYL]-4-YL]AZO]-5-HYDROXY-6-(PHENYLAZO)-, DISODIUM SALT;4-AMINO-3-((4'-((2,4-DIAMINO-5-METHYLPHENYL)-AZO)-(1,1'-BIPHENYL)-4-YL)-AZO)-5-HYDROXY-6-(PHENYLAZO)-2,7-NAPHTHALINDISULFONSAEURE-DI-NA-SALZ