| abstract |
The tris-azo dyes of formula (I) in the free acid from: (where A is the radical of an aromatic diazotisable component; B is the radical of an aromatic hydroxylated and/or aminated coupling component; n = 1 or 2; one X is OH and the other is NH2; Z is a radical of formula (II): in which Y is -SO2-NR; R is H, opt. substd.alkyl, or benzyl; R1 is H, Cl, Br, 1-4C alkyl, CN, COOH, MeO, EtO or NO2; R2 is H, Cl or 1-4C alkyl; R3 is H, Cl, Br, 1-4C alkyl, CN, MeO, EtOH, OH, COOH, NO2 or sulpho; R4 is H, Cl or Br; the azo gps. linked to Z are not in posn. 4:41 when both benzene rings are unsubstd. or monosubstd.), are used as green-black dyes for leather and also for natural or synthetic fibres contg. OH gps. e.g., cellulose, cotton, regenerated cellulose, wool, silk, nylon, and paper. |