Patent ID: 7731762

Claim:
A dye composition comprising: a non-aqueous dye; and an ionic liquid wherein the non-aqueous dye is a polymethine dye comprising a cyanine dye, a merocyanine dye or an oxanol dye, and wherein the cyanine dye is represented by formula (I): wherein Za and Zb each independently represents an atomic group necessary to form a 5- or 6-membered nitrogen-containing heterocyclic ring; R 1 and R 2 each independently represents an alkyl group or an aryl group; L 1 , L 2 , L 3 , L 4 and L 5 each independently represents a substituted or unsubstituted methine group, provided that when there are substituents on L 1 to L 5 , the substituents may be linked to each other to form a ring; j represents 0, 1 or 2; k represents 0 or 1; X n− represents an n-valent anion; and n represents an integer of 1 or more.