2,7-Naphthalenedisulfonic acid, 4,5-dihydroxy-3-((4'-((1-hydroxy-4-sulfo-2-naphthalenyl)azo)-3,3'-dimethyl(1,1'-biphenyl)-4-yl)azo)-, trisodium salt (9CI) 4198-21-4 5442-09-1 C.I. 23690 C.I. Direct Blue 31 C.I. Direct Blue 31, trisodium salt (8CI) Dianil Blue 2R Direct Blue 2R NSC 8678