Toner and method for manufacturing the same

A toner comprising toner particle containing:

• a binder resin, a pigment, a pigment dispersant, and a fixing assistant, wherein
• the pigment dispersant comprises:
• a structure represented by formula (1) or a tautomer thereof, and
• a polymer moiety,
• wherein X, Y and Z each independently represent —O—, a methylene group, or —NR4—, and R4 represents a hydrogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms;
• R1 represents a substituted or unsubstituted phenyl group, a polycyclic aromatic group, or a heterocyclic group;
• R2 represents a hydrogen atom, a substituted or unsubstituted phenyl group, an aralkyl group, a linear, branched, or cyclic alkyl group having 1 to 18 carbon atoms, or a monovalent group obtained by substituting a methylene group of a main chain of an alkyl group having 1 to 18 carbon atoms by an ether bond, an ester bond, or an amide bond;
• R3 represents a substituted or unsubstituted phenylene group, a linear, branched, or cyclic alkylene group having 1 to 18 carbon atoms, or a divalent group obtained by substituting a methylene group of a main chain of an alkylene group having 1 to 18 carbon atoms by an ether bond, an ester bond, or an amide bond;
• W represents a linking group to the polymer moiety;
• a substituent of the substituted phenyl group and a substituent of the substituted phenylene group are each a methyl group, a methoxy group, a hydroxy group, a nitro group, a chloro group, a carboxy group, an amino group, a dimethylamino group, a carboxylic acid amide group, or a ureido group;
• the polycyclic aromatic group is a group obtained by eliminating one hydrogen atom from naphthalene, anthracene, phenanthrene, or anthraquinone;
• and
• the heterocyclic group is a group obtained by eliminating one hydrogen atom from imidazole, oxazole, thiazole, pyridine, indole, benzimidazole, benzimidazolinone, or phthalimide,
• the binder resin and the fixing assistant satisfy the following formula (2),
• (TgA−TgB)≥5.0° C. (2)
• wherein TgA represents a glass transition temperature Tg of the binder resin measured by a differential scanning calorimeter analysis;
• and
• TgB represents a glass transition temperature Tg of a resin mixture measured by a differential scanning calorimeter analysis, the resin mixture consisting of the binder resin and the fixing assistant at a mass ratio of 9:1, and
• a hydrophobic parameter HP1 of the pigment dispersant and a hydrophobic parameter HP2 of the fixing assistant satisfy the following formula (3),
• −0.26≤(HP1−HP2)≤0.15 (3)
• wherein HP1 represents a volume fraction of heptane at a precipitation point of the pigment dispersant as measured by the addition of heptane to a solution containing 0.01 parts by mass of the pigment dispersant and 1.48 parts by mass of chloroform;
• and
• HP2 represents a volume fraction of heptane at a precipitation point of the fixing assistant as measured by the addition of heptane to a solution containing 0.01 parts by mass of the fixing assistant and 1.48 parts by mass of chloroform.