A toner having: a toner particle containing a binder resin including a first resin and a second resin; and an inorganic fine particle on a surface of the toner particle, wherein the first resin has a specific content ratio of a specific monomer unit, acid values of the first unit and second unit are within specific ranges, a domain matrix structure including a matrix containing the first resin and domains containing the second resin appears in cross-sectional observation of the toner, a compound having an alkyl group is present on a surface of the inorganic fine particle, and a volume resistivity of the inorganic fine particle is 1.0×10.sup.5 Ω.Math.cm to 1.0×10.sup.13 Ω.Math.cm.

The present invention provides: a ferrite carrier core material for an electrophotographic developer, the material having a mesh passing amount of 3 wt % or less as indicated by the ratio of the weight of particles passing through a 16 μm-mesh to the weight of whole particles constituting a powder, and having a particle strength index of 2 wt % or less as indicated by a difference between the mesh passing amounts before and after crushing; a ferrite carrier which is for an electrophotographic developer and in which the surface of the ferrite carrier core material is coated with a resin; and an electrophotographic developer which includes the ferrite carrier and a toner.

A toner containing a toner particle, wherein, when a dielectric loss tangent measured at a frequency of 10 kHz in an impedance measurement on the toner in an environment having a temperature of 50° C. and a relative humidity of 50% RH is designated by tanδ50° C.(1), and a dielectric loss tangent measured at a frequency of 10 kHz in an impedance measurement on the toner in an environment having a temperature of 30° C. and a relative humidity of 50% RH after the impedance measurement on the toner in an environment having a temperature of 50° C. and a relative humidity of 50% RH is designated by tanδ30° C.(2), tanδ50° C.(1) is from 0.015 to 0.050, the relationship tanδ50° C.(1)>tanδ30° C.(2) is satisfied, and tanδ30° C.(2)/tanδ50° C.(1) is from 0.25 to 0.66.

An image forming apparatus comprising an electrophotographic photosensitive member and a developing device for supplying a toner onto the electrophotographic photosensitive member, the developing device having the toner, wherein the electrophotographic photosensitive member has a surface layer comprising a binder resin (A), the toner has a toner particle, the toner particle has a core comprising a binder resin (B) and a wax and a shell layer formed on a surface of the core, the binder resin (A) has a prescribed structure: the wax comprises a prescribed monoester compound: and a process cartridge.

A preparing method of an electrostatic charge image developing toner includes: aggregating at least binder resin particles and release agent particles contained in a dispersion to form aggregated particles; heating and coalescing the aggregated particles to form coalesced particles; and filtering and cleaning the coalesced particles to obtain toner particles, in which before the aggregating or during the aggregating, a polymer dispersant is added to the dispersion in an amount of 0.01% by weight or more and 1.3% by weight or less with respect to a total weight of the obtained toner particles.

A toner comprising a toner particle comprising a binder resin, wherein the binder resin comprises a first resin and a second resin, the first resin is a crystalline resin, the second resin is an amorphous resin, in an observation of a cross section of the toner particle with a transmission electron microscope, a matrix-domain structure composed of a matrix comprising the first resin and domains comprising the second resin is present, an area ratio occupied by the matrix in a total area of the matrix and the domains is from 35 area % to 70 area %, a [hydrocarbon group index (Ge)]/[hydrocarbon group index (DIA)] after washing the toner with hexane is 1.10 or more.

A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a coating layer coating the core particle. The coating layer contains a conductive component comprising an element A, and a coating resin comprising an element B. The element A is undetected in the coating resin by an energy dispersive X-ray spectrometer, and the element B is undetected in the conductive component by the energy dispersive X-ray spectrometer. A standard deviation of a value A/B is 0.4 or less, where the value A/B is a ratio of the element A to the element B in intensity measured by the energy dispersive X-ray spectrometer.

A toner including a strontium titanate powdery material as an external additive, the strontium titanate powdery material including Si-containing particles on a surface of the strontium titanate powdery material, the Si-containing particles having a number average circle equivalent diameter of 5 nm or more but 15 nm or less.

A carrier includes carrier particles. Each of the carrier particles includes a carrier core and a coating layer covering the surface of the carrier core. The coating layer contains a silicone resin and conductive particles. Each of the conductive particles includes a transparent conductive substrate composed of a transparent conductive material and a film covering a surface of the transparent conductive substrate. The film contains silica.

A carrier includes carrier particles. Each of the carrier particles includes a carrier core and a coating layer covering the surface of the carrier core. The coating layer contains a silicone resin and conductive particles. Each of the conductive particles includes a transparent conductive substrate composed of a transparent conductive material and a film covering a surface of the transparent conductive substrate. The film contains silica.