According to one embodiment, a toner having excellent heat roller life performance, low-temperature offset resistance, and high-temperature offset resistance, and a toner cartridge and an image forming apparatus, in each of which the toner is stored, are provided.

A toner according to an embodiment contains a colorant, an amorphous polyester resin A, and an amorphous polyester resin B. The amorphous polyester resin A has an Mw.sub.A of 0.9×10.sup.4 to 1.5×10.sup.4. The amorphous polyester resin B has an Mw.sub.B of 4.0×10.sup.4 to 11.0×10.sup.4. The amorphous polyester resin A has an Mn.sub.A of 3.0×10.sup.3 to 4.0×10.sup.3. Mw.sub.A/Mn.sub.A is between 3.1 and 4.0. The amorphous polyester resin B has an Mn.sub.B of 2.2×10.sup.3 to 3.5×10.sup.3. Mw.sub.B/Mn.sub.B is between 11.4 and 50. The content of the amorphous polyester resin A is between 50 and 60 mass %. The content of the amorphous polyester resin B is between 20 and 30 mass %.

A magnetic carrier including a magnetic carrier particle having a magnetic core particle and a coating layer of an organosilicon polymer on a surface of the magnetic core particle, wherein the organosilicon polymer has the structure given by formula (T3) below; in .sup.29Si-NMR measurement of the THF-insoluble matter of the organosilicon polymer, the ratio ST3 of the peak area for the structure given by formula (T3) to the total peak area for the organosilicon polymer is at least 0.05; and in the roughness curve measured on the magnetic carrier particle, the mean width (RSm) of the roughness curve elements of the magnetic carrier particle, and the ratio (σ/RSm) to this RSm of the standard deviation σ of the width of the region where one period of a protrusion and a recess occurs, are in prescribed ranges.
R—Si(O.sub.1/2).sub.3  (T3) R in the formula represents a prescribed substituent.

Provided is an electrostatic latent image developing white toner, including: a white toner including at least a binder resin, a white pigment, and a release agent; and a magnetic carrier including at least a core material, and a coating layer coating the core material and made of a coating resin and conductive particles, wherein Ra of the magnetic carrier is in a range of from 0.50 μm to 1.00 μm, and a bulk density of the magnetic carrier is in a range of from 2.08 g/cm.sup.3 to 2.24 g/cm.sup.3.

Provided is a carrier for electrostatic charge image development which provides a two-component developer having a high electric charge amount, a suppressed variation in an electric charge amount caused by an environmental change, and excellent durability, even if a low temperature fixable toner is used.

A carrier for electrostatic charge image development of the present invention includes: carrier particles in which a core particle surface is coated with a coating material containing a resin, wherein the coating material contains phosphorus element, and the resin contains structural units derived from an alicyclic (meth)acrylic acid ester compound.

An electrostatic charge image developing toner includes toner particles, silica particles having an average particle diameter of 80 nm to 200 nm, lubricant particles N which has negatively chargeable property, and lubricant particles P which has positively chargeable property, wherein a content (s) of the silica particles, a content (n) of the lubricant particles N, and a content (p) of the lubricant particles P satisfy relationships of Expression (1): 0.002≦p/s≦0.2; and Expression (2): 0.02≦n/s≦0.5.

An electrostatic charge image developing toner includes: toner particles; first silica particles having an average circularity of 0.9 to 1.0, a particle size distribution index of 1.05 to 1.25, and a compression aggregation degree of 60% to 95%; and second silica particles having an average circularity of 0.9 to 1.0, a particle size distribution index of 1.05 to 1.25, and a compression aggregation degree of 60% to 95%, wherein, when an average primary particle diameter of the first silica particles is set as Da (nm) and an average primary particle diameter of the second silica particles is set as Db (nm), relationships of the following Expressions (A1) to (A3) are satisfied: Expression (A1): 80≦Da≦120, Expression (A2): 120≦Db≦200, and Expression (A3): 10≦Db−Da≦120.

An object is to provide the ferrite particles used as a magnetic filler or a raw material for a molded product excellent in dispersibility as a powder and excellent in uniformity after molding and result the surface with small unevenness; and a method of manufacturing the particles. To achieve the object, Mn—Mg ferrite particles having an average particle size of 1 to 2000 nm and having a spherical shape are employed. It is preferable that the ferrite particles are produced by a method including subjecting of a ferrite raw material obtained through preparation of a ferrite composition to flame-spraying in air for ferritization followed by rapid cooling for solidifying of the ferrite.

The present invention provides a magnetic carrier for an electrophotographic developer which has an excellent durability and a stable charging property and is free from occurrence of spent toner thereonto, and a two-component system developer comprising the magnetic carrier for an electrophotographic developer and a toner. The present invention relates to a core material of a magnetic carrier for an electrophotographic developer comprising spherical composite particles comprising at least ferromagnetic iron oxide fine particles and a cured phenol resin and having an average particle diameter of 1 to 100 μm, a resin index of the spherical composite particles being within the range of 35 to 80%, and a magnetic carrier obtained by coating a surface of respective particles of the magnetic carrier core material with a resin.

Provided is a magnetic carrier, including: a ferrite core particle; and a coating resin, in which: the coating resin has a surface resin layer and a resin composition in the stated order from a surface side thereof; the resin composition contains a resin, and an inorganic particle or carbon black that is subjected to a hydrophilic treatment; the surface resin layer contains a resin, is free of the inorganic particle or the carbon black, and has a thickness of from 0.01 μm or more to 4.00 μm or less; and a moisture percentage change between a moisture percentage when the magnetic carrier is left to stand under an environment of 30° C. and 80% RH for 24 hours, and a moisture percentage when the magnetic carrier is left to stand under an environment of 23° C. and 5% RH for 24 hours after the standing is 0.030 mass % or less.

An electrostatic charge image developing toner includes a toner particle, a polishing agent particle, and a fatty acid metal salt particle, wherein a rate of the fatty acid metal salt particles strongly attached to the surface of the toner particles is equal to or greater than 50% by number with respect to the fatty acid metal salt particles attached to the surface of the toner particles.