Patent ID: 7513942

Claim:
A fine particle dispersion, wherein fine particles comprising an oil-soluble dye having an oxidation potential higher than 1.0 V vs SCE and a polymer having at least one of an amide group, a glycidyl group and a hydroxyl group are dispersed in an aqueous medium, and the oil-soluble dye is represented by Formula (Y-II), Formula (Y-III) or Formula (Y-IV): wherein, in Formula (Y-II), R 1 and R 3 each independently represent a hydrogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group, an alkoxy group, an alkylthio group, an arylthio group, an aryl group or an ionic hydrophilic group, R 2 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, a carbamoyl group, an acyl group, an aryl group or a heterocyclic group, and R 4 represents a heterocyclic group; in Formula (Y-III), R 5 represents a hydrogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group, an alkoxy group, an alkylthio group, an arylthio group, an aryl group or an ionic hydrophilic group, Za represents —N═, —NH—, or C(R 11 ), Zb and Zc each independently represent —N═ or C(R 11 )═, where R 11 represents a hydrogen atom or a nonmetallic substituent group, and R 6 represents a heterocyclic group; in Formula (Y-IV), R 7 and R 9 each independently represent a hydrogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group or an ionic hydrophilic group, R 8 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, an acylamino group, a sulfonylamino group, an alkoxycarbonylamino group, an ureido group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group, an alkylamino group, an arylamino group, a hydroxy group or an ionic hydrophilic group, and R 10 represents a heterocyclic group.