A toner containing a toner particle including a binder resin, a resin A having a pKa of 6.0-9.0, and a pigment having a pKb of 4.0-7.0, wherein the pKa is an acid dissociation constant measured by preparing a resin solution in which 1.0 part by mass of the resin A, 70.0 parts by mass of toluene and 30.0 parts by mass of ethanol are mixed, and carrying out neutralization titration with a potassium hydroxide ethanol solution of 0.1 mol/L, and the pKb is a basic dissociation constant measured by preparing a pigment dispersion in which 10.0 parts by mass of the pigment, 140.0 parts by mass of toluene and 60.0 parts by mass of ethanol are mixed, and carrying out neutralization titration with a hydrochloric acid ethanol solution of 0.1 mol/L.

A toner comprising a toner particle containing a pigment, a resin A and a resin B, wherein the pigment is a pigment having a structure derived from a basic compound, the resin A has an acidic functional group, the resin B has an acid value of at least 2.0 mg KOH/g, the resin B has a glass transition temperature TgB of at least 50° C., and the hydrophobic parameter HPA of the resin A and the hydrophobic parameter of the resin B satisfy the following formulae:

HPA≧0.60

HPB≦0.70

HPA−HPB>0.

Provided is a toner comprising a toner particle containing: a binder resin; a pigment; a resin having an acidic functional group; and a fixing auxiliary agent, wherein the pigment is a pigment having a structure derived from a basic compound, and the binder resin and the fixing auxiliary agent satisfy following Formula (1):

(TgA−TgB)≧5.0° C.  Formula (1)

and given HP1 as a hydrophobic parameter of the resin having an acidic functional group and HP2 as a hydrophobic parameter of the fixing auxiliary agent, the HP1 is at least 0.60, and following Formula (2) is satisfied:

|HP1−HP2|≦0.30  Formula (2).

A resin particle set includes a fluorescent color resin particle containing a fluorescent coloring agent; and a colored resin particle containing a colored coloring agent, wherein a volume average particle diameter of the fluorescent color resin particles is larger than a volume average particle diameter of the colored resin particles, and an average circularity of the fluorescent color resin particles is 0.93 or more.

[Summary] To provide resin particles with high weather resistance even when a plant-derived resin and PET are used as binder resins.

[Tasks] The Resin particles includes a binder resin and a colorant, wherein the binder resin contains polyethylene terephthalate and a plant-derived resin, wherein the colorant contains an isoindoline pigment, and wherein a radioisotope .sup.14C concentration in the resin particles is 5.4 pMC or higher.

An image forming method is provided. The image forming method includes: forming an electrostatic latent image on an electrostatic latent image bearer; developing the electrostatic latent image on the electrostatic latent image bearer with a toner to form a toner image; transferring the toner image from the electrostatic latent image bearer onto a continuous resin film; fixing the toner image on the continuous resin film with a heat roller or a heat belt. The toner contains a maleic-acid-modified polyolefin having a polypropylene block in a main chain.

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 resin particle includes a binder resin; a fluorescent colorant A; and a colorant B other than the fluorescent colorant A, in which the resin particle includes a region RA in which a content of the fluorescent colorant A is larger than a content of the colorant B and a region RB in which a content of the colorant B is larger than a content of the fluorescent colorant A.

A resin particle set includes a fluorescent color resin particle containing a fluorescent coloring agent; and a colored resin particle containing a colored coloring agent, wherein a volume average particle diameter of the fluorescent color resin particles is larger than a volume average particle diameter of the colored resin particles, and an average circularity of the fluorescent color resin particles is 0.93 or more.

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.