Dyes for ink jet printing

An azo dye of formula (3) ##STR9## wherein R.sub.1 is selected from hydrogen or an aliphatic radical having from 1 to 6 C atoms;

• n is2, 3 or4;
• R.sub.3, R.sub.4 are independently selected from hydrogen, alkyl or alkoxy or acylamino containing up to 3 C atoms;
• X is NR.sub.5 R.sub.6 where
• R.sub.5 and R.sub.6 are independently selected from hydrogen, alkyl from 1 to 6 C atoms, C2 to C6 substituted alkyl where the substituents are selected from OH, OCH.sub.3, COOM, SO.sub.3 M or an aryl substituted by COOM, SO.sub.3 M or R.sub.5, R.sub.6 form a ring without or with inclusion of a hetero atom;
• or
• X is SR.sub.7 in which R.sub.7 is an unsubstituted alkyl from 1 to 6 C atoms, alkyl having 2 to 6 C atoms substituted by OH, OCH.sub.3, COOM, SO.sub.3 M;
• or
• X is OR.sub.8 in which R.sub.8 is hydrogen or an aliphatic radical having from 1 to 6 C atoms;
• m is 1, 2 or 3 and the substitution pattern is selected from 4,8/5,7/6,8/3,6,8 or 4,6,8. In a case where m is 1, --SO.sub.3 M may also be in position 1 or 4 to 8;
• M is hydrogen, a metal atom, an ammonium or ammonium substituted with alkyl, alkoxyalkyl and hydroxyalkyl each having 1 to 12 C atoms.