Trisazo black dyes

Abstract

New trisazo dyes, having the structure ##STR1## in which M represents H, Na, K, Li, or N(R.sub.3)H wherein R represents --H, --CH.sub.3, --C.sub.2 H.sub.5, --C.sub.3 H.sub.7, --CH.sub.2 CH.sub.2 OH, --CH.sub.2 CH(OH)CH.sub.3 or --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 OH; A.sub.1 and A.sub.2, which may be identical or different, represent the residual moiety of a coupling component which contains at least one amino group or one hydroxy group and wherein said coupling component has the following general structures II and III: ##STR2## and in which M has the above meanings; R.sub.1 represents --NH.sub.2 or --OH; R.sub.2 represents --NH.sub.2, --OH, --O--alkyl, --NHCO lower alkyl, --NH aryl, --NH lower alkyl, --N(lower alkyl).sub.2 and --NHCH.sub.2 COOM; R.sub.3 represents hydrogen, a lower alkyl or --SO.sub.3 M; R.sub.4 represents --H, --NH.sub.2, --OH, --O--alkyl, --NHCO lower alkyl, --NH aryl, --NH lower alkyl and --NHCH.sub.2 COOM; and n=0, 1 or 2. They are useful for dyeing substrates which may be dyed by substantive dyes, particularly leather and paper.

Dependencies are inferred from the claim text.