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.

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.

An apparatus and method of manufacturing a white dry ink pulverized toner including a resin and 15%-45% TiO2 pigment having a mean size of 100-350 nm melt mixed with the resin in a twin screw extruder resulting in an extruded mix. The extruded mix is pulverized in a fluid bed jet mill. Fines of the pulverized extruded mix less than 5 microns may be removed from the pulverized extruded mix by classification leaving pulverized particles having a mean size of 6-12 microns. The pulverized particles are blended in a mixer with surface additives including silica and ZnSt, and the white dry ink pulverized toner has a developer charge between 5 and 50 μC/gram and a Lightness (L*) of at least 75 at a toner mass per unit area (TMA) of at most 1.2 mg/cm.sup.2.

Provided is a positive-charging toner having a toner particle that contains a binder resin, the binder resin contains a polymer A having a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer, the first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic acid esters having a C18 to C36 alkyl group, the content of the first monomer unit in the polymer A is 5.0 to 60.0 mol % and the content of the second monomer unit is 20.0 to 95.0 mol %, SP.sub.11 of the first monomer unit and SP.sub.21 of the second monomer unit satisfy 3.00≤(SP.sub.21−SP.sub.11)≤25.00, and the work function of the toner is 5.0 to 5.4 V.

The present invention relates to a toner for electrostatic charge image development, including: a toner base particle having at least a binder resin, a releasing agent, and a colorant, wherein the following formula (1) is satisfied wherein a maximum value and a minimum value of a dielectric loss tangent tan δ, which are obtained by measuring at a frequency in the range of 1 kHz to 100 kHz under the condition at a temperature of 20° C. and a relative humidity of 50% RH, are defined as tan δ.sub.max and tan δ.sub.min, respectively. According to the present invention, a toner for electrostatic charge image development, with which the rising of the toner charge amount is improved while ensuring the low temperature fixability, and a high quality image having less density unevenness can be obtained even during the image forming at a high speed and a high printing rate, is provided.

Frequency showing tan δ.sub.max<Frequency showing tan δ.sub.min  (1)

An electrostatic charge image developing toner set includes a brilliant toner including toner particles that include a brilliant pigment and a first binder resin, a black toner including toner particles that include a second binder resin, and a color toner except a black toner, including toner particles that include a third binder resin, wherein the brilliant toner, the black toner and the color toner satisfy Expression (1): Dielectric loss factor of the brilliant Toner>Dielectric loss factor of the black toner>Dielectric loss factor of the color toner and Expression (2): 25×10.sup.−3≦(Dielectric loss factor of the brilliant toner)−(Dielectric loss factor of the color toner)≦95×10.sup.−3.

An electrostatic charge image developer includes a toner that includes a toner particle; and a carrier, wherein the toner particle contains a brilliant pigment, an exposed amount of the brilliant pigment contained in the toner particle is from 0.5% to 5%, the carrier has a core particle and a coating layer which covers a surface of the core particle, the coating layer contains a silicone resin and a siloxane oligomer, and a content of the siloxane oligomer is from 0.1 ppm to 500 ppm with respect to a total weight of the coating layer.

An image forming apparatus for developing an electrostatic latent image with developer includes a development part, a transfer part, and a fuser. The developer includes first developer with a first coloring agent of yellow and a first external additive, and second developer with a second coloring agent of a color other than yellow and a second external additive. A first peeling rate of the first external additive by a following formula (1) is smaller than a second peeling rate of the second external additive by a following formula (2),

the first peeling rate (%)=[1−(X1/Y1)]×100  (1)

the second peeling rate (%)=[1−(X2/Y2)]×100  (2) X1, Y1 are amounts (weight %) of the first external additive in the first developer after/before the ultrasonic waves are applied, X2, Y2 are amounts (weight %) of the second external additive in the second developer after/before the ultrasonic waves are applied.