An emulsion aggregation toner including a toner particle comprising at least one resin; an optional colorant; an optional wax; and a reactive charge control agent comprising at least one positive charging compound comprising a member selected from the group consisting of an amine compound having at least 3 carbon atoms, an ammonium compound having at least 3 carbon atoms, a phosphonium compound having at least 3 carbon atoms, a boronium compound having at least 3 carbon atoms, and combinations thereof; at least one reactive anchoring compound comprising a member selected the group consisting of amino, epoxy, carboxylic, hydroxyl, silanol, cyanide, anhydride, aldehyde, ketone, vinyl, and combinations thereof; and wherein the charge control agent optionally further comprises a negative charging compound comprising a member selected from the group consisting of aromatic carboxylic acid, silanol, phenol, pyranone, furanone, and combinations thereof.

An emulsion aggregation toner including a toner particle comprising at least one resin; an optional colorant; an optional wax; and a charge control agent disposed on a surface of the toner particle; the control agent comprising a phenyl based siloxane; and a complex formed from a metal ion donor and at least one of a ligand selected from a member of the group consisting of a polyaromatic acid comprising humic acid, a pyranone based ligand, a furanone based ligand, or a combination thereof.

A toner includes toner base and an external additive containing silica. The toner base includes binder resin, colorant, release agent, and modified layered inorganic mineral that is obtained by modifying, with an organic ion, part of ions between layers in layered inorganic mineral. An amount of the modified layered inorganic mineral is 0.1 parts by mass or more and less than 1.4 parts by mass relative to 100 parts by mass of the toner. Liberation ratio A (% by mass) of silica from the toner satisfies relation (1): 0.5≤A≤1.0. The binder resin includes a component insoluble in THF and a component soluble in THF. The component insoluble in THF has two glass transition temperatures of Tga1st and Tgb1st at first temperature rise in DSC. The Tga1st is −40° C. or more and 10° C. or less. The Tgb1st is 45° C. or more and 65° C. or less.

The present disclosure provides a process cartridge and an electrophotographic apparatus in which fogging is reduced so as to reduce an amount of toner consumed. A process cartridge configured to be detachably attachable to a main body of an electrophotographic apparatus includes a developing unit containing a toner, and an electrophotographic photosensitive member, wherein the toner is a toner that has a toner particle, and has a metal salt of a polyvalent acid at least on a part of a surface of the toner particle; wherein the metal salt of the polyvalent acid includes at least one kind of metal element selected from metal elements belonging to from Group 3 to Group 13, and a surface layer of the electrophotographic photosensitive member contains an acrylic resin or a methacrylic resin.

A toner having a toner particle containing a binder resin and a styrene-acrylic resin, the toner being characterized in that the styrene-acrylic resin is a graft polymer having an aliphatic hydrocarbon compound segment and a styrene-acrylic segment, the styrene-acrylic segment has a specific monomer unit, the melting point of the styrene-acrylic segment is from 30° C. to 80° C., and when the toner is measured using a FT-IR ATR method, the intensity assigned to the styrene-acrylic resin and the intensity assigned to the binder resin satisfy a specific relationship.

A toner comprising a toner particle comprising a core particle comprising a binder resin and a diester wax, and a shell on a surface of the core particle, wherein the following formulas (1) and (2) are satisfied, where Sp is a partition coefficient of the shell and Wp is a partition coefficient of the diester wax:

Sp≤0.40  (1), and

16.00≤Wp−Sp≤20.00  (2).

A toner comprising a toner particle comprising a core particle comprising a binder resin and a wax, and a shell formed on a surface of the core particle, wherein the wax comprises a wax A, the shell comprises a resin comprising a functional group B, the wax A has a surface charge density DA of −0.0080 to −0.0025, and an absolute difference |DA−DB| between the surface charge density DA of the wax A and a surface charge density DB of the functional group B is not more than 0.0025.

Toner comprising a toner particle comprising a core particle comprising a binder resin and a shell formed on a surface of the core particle, wherein given YA (number %) as an abundance ratio of particles with a particle perimeter of less than 6.332 μm, in a dispersion of the toner treated under the following ultrasound condition A, given XB as an average aspect ratio of the toner and YB (number %) as an abundance ratio of particles with a particle perimeter of less than 6.332 μm, in a dispersion of the toner treated under the following ultrasound condition B, 0.75≤XB≤0.85 and 0.10≤YA−YB≤2.50 are satisfied: where ultrasound condition A: output frequency 30 kHz, output capacity 15 W, ultrasound intensity 100%, exposure time 300 s, and ultrasound condition B: output frequency 30 kHz, output capacity 15 W, ultrasound intensity 5%, exposure time 300 s.

A toner for electrostatic image development includes: toner particles; Si-doped strontium titanate particles; and silica particles. The particle diameter D of at least one peak in a number-based particle size distribution of primary particles of the silica particles is larger than the number-based median diameter D.sub.50 of primary particles of the Si-doped strontium titanate particles.

A toner includes toner particles and zinc stearate particles. The toner particles each include a toner mother particle containing a binder resin. The zinc stearate particles have a 50% volume cumulative diameter of at least 3.0 μm and no greater than 6.0 μm. A presence ratio of the zinc stearate particles having a particle diameter of no greater than 1.0 μm is no greater than 2.0% by volume relative to a total amount of the zinc stearate particles. A presence ratio of the zinc stearate particles having a particle diameter of at least 10.0 μm is no greater than 2.0% by volume relative to the total amount of the zinc stearate particles.