The present invention provides a compound and a pigment dispersant, each of which improves the dispersibility of various types of pigments in a non-aqueous solvent and also provides a pigment composition, a pigment dispersion, and a toner, each of which has a preferable coloring power. The compound includes a polymer which has a monomer unit having a specific structure and also includes a specific partial structure.

Provided is a toner that uses a crystalline resin, and demonstrates favorable dispersibility of the crystalline resin in the toner, demonstrates superior low-temperature fixability, and is able to inhibit fogging. The toner has a toner particle comprising a resin A, which has a long-chain alkyl group having an average number of carbon atoms of 27 to 50, and a crystalline resin, wherein the SP value (cal/cm.sup.3).sup.1/2 of the crystalline resin is 9.00 to 12.00, and in a GC/MS analysis of components that volatize when the toner is heated for 10 minutes at 200° C., the amount of volatile components of saturated hydrocarbons having 30 to 37 carbon atoms is 90 ppm to 260 ppm of toluene equivalent, based on mass.

The pigment dispersion is a pigment dispersion including a fluorescent agent, wherein, when at a wavelength of 250 nm or more and 290 nm or less, an integral value of an emission intensity in a wavelength range of 400 nm or more and 700 nm or less of an emission spectrum of the fluorescent agent for excitation light is represented by F1, an integral value of an emission intensity in a wavelength range of 400 nm or more and 700 nm or less of an emission spectrum of the pigment dispersion for excitation light is represented by F2, and a ratio of the fluorescent agent contained in a solid content obtained when the pigment dispersion is heated at 130° C. until a change in mass of the pigment dispersion reaches 0.3%/min or less is represented by W1 (mass%), the F1, the F2, and the W1 satisfy the formulae F2x 100/W1≥F1 ×0.30 and 5.0≤W1≤80.0.

Provided is a positive-charging toner having a toner particle that contains a binder resin, the binder resin contains a polymer A having a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer, the first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic acid esters having a C18 to C36 alkyl group, the content of the first monomer unit in the polymer A is 5.0 to 60.0 mol % and the content of the second monomer unit is 20.0 to 95.0 mol %, SP.sub.11 of the first monomer unit and SP.sub.21 of the second monomer unit satisfy 3.00≤(SP.sub.21−SP.sub.11)≤25.00, and the work function of the toner is 5.0 to 5.4 V.

A toner for developing an electrostatic latent image includes: toner base particles containing a hybrid crystalline polyester resin having a crystalline polyester polymerized segment and an amorphous polymerized segment chemically bonded to each other and an amorphous resin; and an external additive including fatty acid metal salt particles, wherein a volume median diameter of the fatty acid metal salt particles is from 3.0 to 5.0 μm.

Disclosed is a toner which is excellent in low-temperature fixability, high-temperature offset resistance, storage stability and durability, while having a wide range of fixing temperature. Also disclosed is a polyester resin used for such a toner. The polyester resin is one of the following polyester resin (A)-(E) for toners. (A) A polyester resin for toners having an Mp as determined by GPC of not less than 12,000 and having an unsaturated double bond (B) A polyester resin for toners obtained by crosslinking the polyester resin (A) (C) A polyester resin for toners containing the polyester resin (A) and another polyester resin having an Mp as determined by GPC of less than 12,000 (D) A polyester resin for toners obtained by crosslinking the polyester resin (C) (E) A polyester resin for toners containing a THF soluble fraction and a THF insoluble fraction wherein the Mw/Mn of the THF soluble fraction is not less than 6 and the total of the acid value and the hydroxyl value of the THF insoluble fraction is not more than 40 mgKOH/g.

A polymer including a unit having a phthalocyanine structure, the polymer having a high capability of dispersing pigments. A pigment composition, a pigment dispersion, and a toner all having a high tinting strength.

An object of the present invention is to provide a photoresponsive polymer that sufficiently secures photoresponsiveness to be fluidized by light irradiation and reversibly non-fluidized, improves fixability, and further has good color reproducibility.

Provided is a photoresponsive polymer containing a structural unit derived from a specific azomethine derivative, the photoresponsive polymer being fluidized by light irradiation and reversibly non-fluidized.

The invention is to provide a positively charging electrostatic image developing toner capable of providing a high quality and high gloss and excellent in stability in long term use and environmental stability, and especially not causing fog in the use at high temperature and high humidity condition. The present invention relates to an electrostatic image developing toner comprising toner mother particles containing a binder resin and a colorant, wherein the binder resin contains a repeating unit having 4 to 20 ether bonds, containing a carbon atom, a hydrogen atom and an oxygen atom, and accounting for a specific amount.

An object of the present invention is to provide an electrostatic image developing toner including toner particles containing: an amorphous resin including an amorphous vinyl resin; and a crystalline resin, wherein the toner particles contain: a coloring agent including C. I. Pigment Yellow 74; and alkoxy aniline with an amount in the range of 0.1 to 50.0 mass ppm in the toner particles.