Patent ID: 7094280

Claim:
A water-soluble complex dye comprising an azo compound represented by the following formula (1) or its tautomer, and transition metal ions: wherein in the formula (1), A 1 is a 5- to 7-membered hetero monocyclic group containing one or two hetero atoms among the ring forming atoms, or a condensed heterocyclic group containing such a hetero monocyclic group and may have an optional substituent, provided that it is a group which does not have a hydroxyl group as a substituent at a position adjacent to the carbon atom bonded to the azo group; ring X 1 represents a condensed hetero ring containing a 6-membered hetero ring, said 6-membered hetero ring being a group bonded to the azo group, and may have an optional substituent; and each of R 1 and R 2 which are independent of each other, represents a hydrogen atom or a monovalent substituent.