Disclosed is a dye compound for black ink which has high 
solubility in media composed mainly of water and which is stable even when a high-concentration 
aqueous solution and ink are stored over a long term. The density of printed images is very high, and even if a high-concentration solution is used for printing, no 
bronzing occurs in the images, and black recorded images are provided with which all aspects of printed image durability, particularly light resistance and 
ozone gas resistance, are excellent. Also disclosed is an ink composition thereof. Trisazo compounds represented by general formula (1) or tautomers thereof or salts thereof are used as said dye compound for black ink.In formula (1), group A represents a 2-naphthothiazolyl group, R1 represents a substitutable C1 to C4 
alkyl group or the like, R2 represents a cyano group or the like, R3 and R4 independently represent a 
hydrogen atom, a sulfo group, or the like, R5 to R7 independently represent a 
hydrogen atom, a substitutable C1 to C4 
alkyl group, or a substitutable C1 to C4 
alkoxy group, or the like, and R8 to R10 independently represent a 
hydrogen atom, a substitutable C1 to C4 
alkyl group, a substitutable C1 to C4 alkxy group, a substitutable C1 to C4 alkylthio group, or the like.