A toner comprising a toner particle comprising a colorant, a binder resin, and calcium carbonate particles, wherein an amount of the colorant in the toner particle is from 1.0 to 20.0% by mass; the binder resin comprises a polyester resin; the polyester resin has an aromatic ring concentration of from 50 to 70 mol %; a surface of the calcium carbonate particles is coated with a fatty acid; an amount of the calcium carbonate particles in the toner particle is from 1.0 to 15.0% by mass; a number average particle diameter of the calcium carbonate particles is from 150 nm to 800 nm.

Provided is a toner blend composition comprising a first pigmented toner and a second toner that is devoid of any pigment additive, i.e., a ‘non-pigmented or clear toner’. The non-pigmented or clear toner is about 1% to about 15% by weight of the toner blend composition. The resulting inventive toner blend composition surprisingly exhibits similar print density on a page compared to a fully pigmented toner. Moreover, this toner blend composition exhibits improvement in toner usage per page, thus lowering toner cost compared to a fully pigmented toner. The non-pigmented or clear toner may be used in combination with either a monochrome or conventional toner using a carbon black pigment, or a chemically processed toners (‘CPT′’) toners using a black pigment, magenta pigment, yellow pigment or a cyan pigment.

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 1.00×10.sup.12 Ω.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.

Provided is a process cartridge that is excellent in initial charge rising performance, and in charge uniformity of a halftone image throughout a long period of time from the start of use until after endurance. Specifically, provided is a process cartridge including: an electrophotographic photosensitive member; a toner; and a developing unit, wherein the toner contains toner particles and an external additive A, the external additive A, and wherein the electrophotographic photosensitive member includes an electroconductive support, a photosensitive layer, and a surface protective layer, wherein the surface protective layer contains electroconductive particles.

A toner composition having improved toner usage efficiency, wherein toner particles having an average size range of 1-25 μm may be mixed with an extra particulate additive package including a first small silica surface treated with both a silane and an aminosilane having a primary particle size of about 5 nm-20 nm, a second fumed silica having a primary particle size of 30 nm-60 nm, a third silica having a primary particle size of about 70 nm-120 nm, an electro-conductive titania having a primary particle size of 30 nm-60 nm and an acicular titania having a size of about 1.6 μm to 1.7 μm in length and about 130 nm in diameter. An alternative embodiment of the extra particulate additive package does not include a third silica having a primary particle size of about 70 nm-120 nm.

A toner having: a toner particle containing a binder resin including a first resin that is a crystalline resin and a second resin that is an amorphous resin; and a fine particle on a surface of the toner particle, wherein the first resin contains a specific ratio of a specific monomer unit, an acid value of the first resin and an acid value of the second resin arc within specific ranges, a domain-matrix structure formed of a matrix containing the first resin and domains containing the second resin appears in cross -sectional observation of the toner, and the fine particle has on the surface a compound containing nitrogen atoms bound or adsorbed thereon.

An electrostatic charge image developing toner has toner particles that contain a binder resin including a crystalline resin and a release agent and an external additive, in which in a case where d represents a volume-average particle size of the toner particles, the number of domains of the crystalline resin existing in a region from a surface of each of the toner particles to a position at a depth of 0.2d from the surface is 30% by number or more and 90% by number or less with respect to the total number of domains of the crystalline resin.

A toner for electrostatic charge image development includes toner particles, the toner particles containing a binder resin containing a vinyl resin and a release agent containing an ester wax, in which in sections of the toner particles, a number average of equivalent circle diameters of sections of domains of the release agent is 0.10 μm or more and 1.5 μm or less, and a standard deviation of the equivalent circle diameters is more than 0.05 and 0.5 or less.

Provided is a toner including toner particles. Each of the toner particles includes a toner base particle including a binder resin and a release agent. The toner particles have an average circularity of 0.974 or greater and 0.985 or less. An arithmetic mean height Sa of surfaces of the toner particles is 45 nm or greater. The toner particles have a BET specific surface area of 1.3 m.sup.2/g or greater and 2.5 m.sup.2/g or less.

Provided are a process cartridge and an electrophotographic apparatus each capable of suppressing an image defect (coarseness in a halftone image) caused by toner scattering in association with a charging failure that occurs when the process speed of the electrophotographic apparatus is further increased. The process cartridge includes: an electrophotographic photosensitive member; and a developing unit, which includes a toner storing portion that stores a toner, and which supplies the toner to a surface of the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a surface protective layer containing an electroconductive particle in an appropriate amount, and the volume resistivity of the surface protective layer is controlled. As the toner, there is used a toner in which an organosilicon polymer is present on the surface of a toner particle, a silanol group is present in part of the organosilicon polymer, and the amount of the silanol group is controlled.