7,7-(carbonyldiimino)bis[4-hydroxy-2-naphthalenesulfonic acid]; 5,5-DIHYDROXY-7,7-DISULPHO-2,2-DINAPHTHYL UREA; J Acid Urea; Bis-J Acid; 4,4'-dihydroxy-7,7'-ureylenedi(naphthalene-2-sulphonic acid); 7,7'-(Carbonyldiimino)bis[4-hydroxy-2-naphthalenesulfonic acid]; 6,6'-ureylene-bis(1-naphthol-3-sulfonic acid); phosgenated; N,N'-bis(4-hydroxy-2-sulfonaphthalene-7-yl)urea; 7,7'-Ureylenebis(4-hydroxy-2-naphthalenesulfonic acid); N,N'-Bis[6-(1-naphthol-3-sulfonic acid)]urea; 2-Naphthalenesulfonic acid, 7,7-(carbonyldiimino)bis4-hydroxy-; 4-hydroxy-7-{[(5-hydroxy-7-sulfonaphthalen-2-yl)carbamoyl]amino}naphthalene-2-sulfonic acid