A toner comprising an organosilicon polymer particle and a toner particle containing a binder resin and a wax, wherein the organosilicon polymer particle contains an organosilicon polymer, a part of silicon atoms in the organosilicon polymer has a T3 unit structure, a ratio of an area of peaks derived from silicon having the T3 unit structure relative to a total area of peaks derived from all silicon element contained in the organosilicon polymer particle is from 0.70 to 1.00 in .sup.29Si-NMR measurement of the organosilicon polymer particle, a plurality of domains of the wax are present in a cross-section of the toner particle, the wax is an ester wax, the average long diameter of the domains of the ester wax is from 0.03 μm to 2.00 μm, and the SP value SPw of the wax is from 8.59 to 9.01.

A toner comprising: a toner particle containing a binder resin; and an external additive, wherein the external additive comprises an external additive A and B; the external additive A has a number-average primary particle diameter of 35 to 300 nm, a dielectric constant ε.sub.ra of not more than 3.50, and a shape factor SF-1 of not more than 114, and is an organosilicon polymer particle having a particular T3 unit structure; a proportion for an area of a peak originating from silicon having the T3 unit structure with reference to that of all silicon elements is 0.50 to 1.00; the external additive B has a number-average primary particle diameter of from 5 nm to 25 nm and a dielectric constant ε.sub.rb that satisfies formula (A): 0.50≤ε.sub.rb−ε.sub.ra (A); and a coverage ratio by the external additive B for the toner particle surface is 50% to 100%.

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer of the conductive member comprises a matrix domain structure, at least a part of the domains Dt is exposed at the conductive member outer surface, the matrix has a volume resistivity R1 of larger than 1.00×10.sup.12 Ω.Math.cm, the domains Dt has a volume resistivity of smaller than R1, the developing device comprises the toner, domains Dc formed of the crystalline material exist in a cross section of the toner, distances between adjacent wall surfaces of the domains Dc is from 30 to 1,100 nm, and a weight-average particle diameter D4 of the toner and distances Dms between adjacent wall surfaces between the domains Dt satisfies D4≥Dms.

An electrophotographic apparatus having an electrophotographic photosensitive member, a charging unit, and a developing unit for forming a toner image on a surface of the electrophotographic photosensitive member, wherein the charging unit has a conductive member disposed to be contactable with the electrophotographic photosensitive member; a conductive layer at the surface of the conductive member has a matrix and a plurality of domains dispersed in the matrix; at least a portion of the domains is exposed at the outer surface of the conductive member; the outer surface of the conductive member is constituted of at least the matrix and the domains; a volume resistivity R1 of the matrix is greater than 1.0010.sup.12 .Math.cm; a volume resistivity R2 of the domains is smaller than R1; the developing unit contains the toner; and a dielectric loss tangent of the toner is at least 0.0027.

A toner includes toner particles. The toner particles each include a toner mother particle. The toner mother particles contain a binder resin, a magnetic powder, and a charge control agent. The binder resin includes a block polymer. The block polymer has a polyester portion and a vinyl polymer portion. The charge control agent includes a styrene-acrylic resin having a quaternary ammonium group. A content percentage of the charge control agent in the toner mother particles is at least 1.5% by mass and no greater than 12.0% by mass.

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, the conductive layer at the outer surface of the conductive member comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the outer surface of the conductive member, the matrix has a volume resistivity R1 of larger than 1.0010.sup.12 .Math.cm, the volume resistivity R1 of the matrix is 1.010.sup.5 times or more a volume resistivity R2 of the domains, the developing device comprises the toner comprising a toner particle and a silica fine particle, and a coverage ratio of the toner surface with the silica fine particles is from 62.0% by area to 100.0% by area as determined by X-ray photoelectron spectroscopy.

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.0010.sup.12 .Math.cm and is 1.010.sup.5 times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.010.sup.3 to 1.010.sup.10 .Math.cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.010.sup.11 to 1.010.sup.17 .Math.cm.

A method for producing a composite resin particle dispersion includes: performing polymerization A by polymerizing a styrene compound and a vinyl monomer other than the styrene compound to form a styrene-based resin; performing polymerization B by polymerizing a (meth)acrylic acid ester compound in the presence of the styrene-based resin to form intermediate resin particles containing the styrene-based resin and a (meth)acrylic acid ester-based resin; and performing polymerization C by polymerizing a styrene compound and a vinyl monomer other than the styrene compound in the presence of the intermediate resin particles to form composite resin particles. The mass ratio of the styrene-based resin to the (meth)acrylic acid ester-based resin in the composite resin particles is from 80:20 to 20:80. A difference between the lowest glass transition temperature and the highest glass transition temperature in the composite resin particles is 30 C. or more.

Provided is an image forming apparatus including an image bearer, a developing unit configured to develop with a toner, an intermediate transfer member, and a transferring unit, wherein the intermediate transfer member is a laminate including a base layer and an elastic layer including particles at a surface thereof to form convex-concave shapes at the surface, the particles have volume resistivity of from 110.sup.0 ohm*cm through 110.sup.9 ohm*cm, the toner includes additive, an amount of the additive separated from the toner is from 20 percent by mass through 35 percent by mass relative to a total amount of the additive in the toner when a toner dispersion liquid in which the toner is dispersed in a dispersant is irradiated with ultrasonic wave vibration with an irradiation energy dose of 4 kJ, and the toner has a dielectric constant of 2.6 or greater but 3.9 or less.

An electrostatic charge image developing toner includes: toner particles including an amorphous resin and a crystalline polyester resin including a polycondensate of a linear dicarboxylic acid and a linear dialcohol having 2 to 12 carbon atoms; and an external additive including silica particles having a BET specific surface area of 100 m.sup.2/g or more. The electrostatic charge image developing toner satisfies the expression: 0.05H2/H10.95, wherein H1 (mW/g) is an endothermic energy amount based on an endothermic peak derived from the crystalline polyester resin in a first temperature increase process in differential scanning calorimetry according to ASTM D3418-8 (2008), and H2 (mW/g) is an endothermic energy amount based on an endothermic peak derived from the crystalline polyester resin in a second temperature increase process in differential scanning calorimetry according to ASTM D3418-8 (2008).