A toner comprising a toner particle comprising a binder resin and an azo dye, wherein the binder resin comprises a polymer A, the polymer A is a polymer having a monomer unit derived from methacrylonitrile, and a relationship among an amount of substance (mol) of the monomer unit derived from methacrylonitrile, an amount of substance (mol) of the azo dye, and the number of azo groups in the azo dye in the toner particle satisfies formula below:
[(amount of substance of azo dye (mol))×(number of azo groups in azo dye)/(amount of substance of monomer unit derived from methacrylonitrile (mol))]≤0.500.

An electrostatic image developing toner includes an amorphous polyester resin, a crystalline polyester resin, and C.I. Pigment Red 57:1, wherein a Net intensity N.sub.Mg of an Mg element, the Net intensity N.sub.Mg of being determined by X-ray fluorescence analysis, is 0.10 kcps or more and 0.40 kcps or less.

A composition includes an isomerized polymer containing a structural unit containing an isomerized structure and an isomerized low molecular weight compound, the composition being fluidized by light irradiation from a solid state and being reversibly non-fluidized.

Provided is a magenta toner which is more excellent in durability in a high temperature and high humidity environment than conventional ones. The magenta toner comprises a binder resin, a magenta colorant, a release agent and an external additive. The release agent has a maximum endothermic peak in a range of from 70° C. to 80° C. during temperature increase, in a DSC curve measured by a differential scanning calorimeter. Needle-shaped oxide fine particles having an average long diameter of from 30 nm to 500 nm and an aspect ratio of from 4 to 20 are contained therein. Zinc stearate particles having a number average primary particle diameter of from 0.1 μm to 5 μm are contained at an amount of from 0.01 part by mass to 0.5 part by mass with respect to 100 parts by mass of the colored resin particles, as the external additives.

A toner comprising a toner particle comprising a binder resin, wherein the toner particle comprises a compound represented by a following structural formula (1) and a compound represented by a following structural formula (2), and a content of the compound represented by the following structural formula (2) comprised in the toner is 0.3 mass ppm or more,

##STR00001##

A yellow toner which provides, even in small amounts, a sharper color and brighter gloss, and higher reflection density than ever before, and which has excellent light resistance. The yellow toner contains a binder resin and a yellow colorant, wherein, as the yellow colorant, at least one of the compound A represented by the following general formula (1) and the compound B represented by the following general formula (2), and the compound C represented by the following formula (3) are contained: ##STR00001##

A toner for electrostatic image development contains: toner base particles containing at least a nonionic surfactant, a binder resin, and a release agent; and an external additive. The content of the nonionic surfactant is from 0.05% by mass to 1% by mass inclusive based on the total mass of the toner, and the external additive contains tin oxide particles.

A toner comprising a toner particle comprising a binder resin and an azo dye, wherein the binder resin comprises a polymer A, the polymer A is a polymer having a monomer unit derived from methacrylonitrile, and a relationship among an amount of substance (mol) of the monomer unit derived from methacrylonitrile, an amount of substance (mol) of the azo dye, and the number of azo groups in the azo dye in the toner particle satisfies formula below:

[(amount of substance of azo dye (mol))×(number of azo groups in azo dye)/(amount of substance of monomer unit derived from methacrylonitrile (mol))]≤0.500.

A toner container used in an image forming apparatus including an exposure unit with a light emitting diode light source includes a container body, and a cyan toner stored in the container body. A lightness L*, a hue a*, and a hue b* of the cyan toner in a powder state satisfy
26.94L*34.84,
5.13a*3.83, and
47.47b*36.78.

A compound represented by the Formula (1), in which, in the Formula (1), R.sup.1 and R.sup.2 each independently represent an alkyl group having 1 to 12 carbon atoms, and the alkyl group having 1 to 12 carbon atoms may have a substituent; R.sup.3 represents a halogen atom, a nitro group, a cyano group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an acyl group having 2 to 12 carbon atoms; and R.sup.1 and R.sup.2 may be bonded to each other to form a ring, is provided.