2052-25-7 Benzenesulfonic acid, 3-((1,5-dihydroxy-2-naphthalenyl)azo)-4-hydroxy-, monosodium salt EINECS 218-145-5 MORDANT BLACK 9 Sodium 3-((1,5-dihydroxy-2-naphthyl)azo)-4-hydroxybenzenesulphonate