Patent ID: 6984723

Claim:
A process for dyeing natural and synthetic material, which comprises dyeing said material with a mono-copper complex of a dye of formula wherein Z 1 and Z 2 are each independently of the other hydrogen, hydroxy, alkoxy or a radical —NHR 5 , R 5 being hydrogen, alkyl, aryl, —COR 6 , —CO—NHR 6 , —SO 2 R 6 or —COOR 6 , R 6 being hydrogen, alkyl or aryl, R 1 and R 3 are each independently of the other hydroxy or alkoxy, or one of these radicals may also be alkyl, R 2 and R 4 are each independently of the other hydrogen, hydroxy, alkyl or alkoxy, halogen, sulfo, carboxy, —NHCONHR 6 or —NHCOR 6 , X is a bridging member but not a direct bond, n and m are each independently of the other 1 or 2, the OH groups in the naphthyl radicals being in the o-position to the azo groups, and wherein the rings A and B may each independently of the other carry a fused-on benzene ring, or a mixture of such a mono-copper complex with the bis-copper complex of such a dye, the mixture containing up to 50% by weight of the bis-copper complex.