Process for dyeing paper with disazo dyes

A process for the dyeing of paper, which comprises dyeing the paper with a dye of formula ##STR457## wherein Y is sulfo or carboxy, and

• X is a group of formula ##STR458## wherein D is the radical of an aromatic, carbocyclic or heterocyclic diazo component,
• KK is a coupling component,
• B is the radical of an aromatic diamine,
• R.sub.1 is hydrogen, C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy, --NH--CO--C.sub.1 -C.sub.4 alkyl or --NH--CO--NH.sub.2,
• R.sub.2 is hydrogen, C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy, sulfo or carboxy,
• R.sub.3 is hydrogen, C.sub.1 -C.sub.4 alkyl, sulfo or carboxy, and
• M is hydrogen or the equivalent of a colourless cation, and Y and the free amino group at the phenylamino radical in formula (1) are ortho-positioned to each other, and said phenylamino radical is in 6- or 7-position, and with the proviso that D is not the radical of 4-nitro-4'-aminostilbene-2,2'-disulfonic acid or 4,4'-diaminostilbene-2,2'-disulfonic acid.