Patent ID: 8808949

Claim:
A dye dispersion liquid comprising a dye (A), a dispersant (B) and a solvent (C), the dye (A) being dispersed in the solvent (C) by the dispersant (B), wherein the dye (A) is a dye having a sulfonic acid group; the dispersant (B) is a block polymer that contains a block portion comprising a repeating unit having a tertiary amine represented by the following formula (I) and a block portion comprising a repeating unit represented by the following formula (III); the solvent (C) is a solvent having a solubility of the dye (A) of 0.2 (g/100 g solvent) or less at 23° C.; and a micelle is formed by an acid-base interaction between the tertiary amine of the dispersant (B) and the sulfonic acid group of the dye (A); wherein in the formula (I), R 1 is a hydrogen atom or a methyl group; “A” is a direct bond or a divalent linking group; R 2 is an alkylene group having 1 to 8 carbon atoms or a divalent organic group described by —[CH(R 6 )—CH(R 7 )—O] x —CH(R 6 )—CH(R 7 )— or —[(CH 2 ) y —O] z —(CH 2 ) y —; each of R 3 and R 4 is independently a chain and/or cyclic hydrocarbon group which can be substituted, or R 3 and R 4 are bound to each other to form a cyclic structure; each of R 6 and R 7 is independently a hydrogen atom or a methyl group; “x” is an integer of 1 to 18; “y” is an integer of 1 to 5; and “z” is an integer of 1 to 18; in the formula (III), R 10 is a hydrogen atom or a methyl group; “A” is a direct bond or a divalent linking group; R 11 is one selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an aralkyl group, an aryl group and a monovalent group described by —[CH(R 12 )—CH(R 13 )—O] x —R 14 or —[(CH 2 ) y —O] z —R 14 ; each of R 12 and R 13 is independently a hydrogen atom or a methyl group; R 14 is one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an aralkyl group, an aryl group and a monovalent group described by —CHO, —CH 2 CHO or —CH 2 COOR 15 ; R 15 is a hydrogen atom or a straight-chain, branched or cyclic alkyl group having 1 to 5 carbon atoms; “x” is an integer of 1 to 18; “y” is an integer of 1 to 5; and “z” is an integer of 1 to 18.