Abstract: An object of the present invention is to provide a ferrite carrier core material for an electrophotographic developer having desired resistance properties and charging properties with small environmental variation of resistivity and charge amount while maintaining the advantages of ferrite carriers, a ferrite carrier for an electrophotographic developer, an electrophotographic developer using the ferrite carrier, and a method for manufacturing the ferrite carrier core material for an electrophotographic developer. In order to solve the problem, a ferrite carrier core material comprising ferrite particles containing 15 mass % or more and 25 mass % or less of Mn, 0.5 mass % or more and 5.0 mass % or less of Mg, 0.05 mass % or more and 4.0 mass % of Sr, and 45 mass % or more and 55 mass % or less of Fe, with Si localized in the surface thereof is used.

Abstract: A toner includes a toner particle containing a binder resin and a silica fine particle A on a surface of the toner particle, wherein D50 on a number basis of the toner is 3.0 to 6.0 the silica fine particle A is a particle having a particle diameter of 80 to 500 nm, the particle diameter being confirmable by observing the toner with a SEM, and when the average coverage with the silica fine particle A determined by image analysis of a particle group of a small particle diameter side of the toner with a SEM is set to Ss and the average coverage with the silica fine particle A determined by image analysis of a particle group of a large particle diameter side of the toner with a scanning electron microscope is set to S1, Ss is 20 to 70 area %, Ss and S1 satisfy S1/Ss?0.80.

Abstract: A positively chargeable toner includes toner particles. The toner particles each include a toner mother particle containing a binder resin, and an external additive adhering to a surface of the toner mother particle. The external additive includes specific silica particles, specific titania particles, and specific crosslinked resin particles. The specific silica particles each include a silica base, and a first surface treatment layer present on a surface of the silica base. The first surface treatment layer has an alkyl group having a carbon number of at least 8 and no greater than 16, and an amino group. The specific titania particles each include a titania base, and a second surface treatment layer present on a surface of the titania base. The second surface treatment layer has an alkyl group having a carbon number of at least 3 and no greater than 8.

Abstract: A toner for developing electrostatic images includes at least a binder resin and a colorant containing a copper phthalocyanine compound, wherein in X-ray diffraction using a CuK? ray, the toner has peaks at a Bragg angle of 2?=7.0±0.1° and at a Bragg angle of 2?=9.1±0.2° and additionally has a peak between the two peaks.

Abstract: Provided is an electrophotographic photosensitive member that suppresses image smearing at the time of its repeated use, and expresses satisfactory wear resistance and electric characteristics. The electrophotographic photosensitive member includes a support and a photosensitive layer in the stated order, wherein a surface layer of the electrophotographic photosensitive member contains a copolymer of a hole-transportable compound having a chain-polymerizable functional group and a specific compound having maleimide groups.

Abstract: A photosensitive member (1) includes a conductive substrate (2) and a photosensitive layer (3). The photosensitive layer is a single-layer photosensitive layer (3c). The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The hole transport material includes a triphenylamine derivative represented by general formula (HT). The electron transport material includes a compound represented by general formula (ET1), (ET2), (ET3), (ET4), or (ET5).

Abstract: Provided are an electrophotographic photosensitive member including a support and a photosensitive layer above the support, in which a surface layer of the electrophotographic photosensitive member includes a polymerization product of a composition containing a specific hole transporting compound, and an electrophotographic apparatus and a process cartridge including the electrophotographic photosensitive member. Also provided is a method of producing the electrophotographic photosensitive member, including (i) forming a coating film of a coating solution for a surface layer which is a composition containing a specific hole transporting compound, and (ii) forming the surface layer of the electrophotographic photosensitive member by a polymerization reaction of the composition containing the specific hole transporting compound.

Abstract: A charge transport molecule contains four radical polymerizable functional groups of the general structure exemplified below: where R1 and R2 contain a spacer group and a radical polymerizable functional group, R3 and R4 are hydrogen atoms, and R5 and R6 contain a spacer group and a radical polymerizable functional group wherein the spacer group of R1, R2, R5 and R6 is an ethyl group and the radical polymerizable functional group of R1, R2, R5 and R6 is an acrylate group.

Abstract: An electrophotographic photosensitive member includes a photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, and a binder resin. The binder resin contains a polyarylate resin represented by general formula (1). In general formula (1), r and s each represent an integer of at least 0 and no greater than 49 and t and u represents an integer of at least 1 and no greater than 50. Furthermore, r+s+t+u=100 and r+t=s+u. X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1), (1-2), (1-3), or (1-4).

Abstract: An electrophotographic photoreceptor includes a conductive substrate, an undercoating layer that is disposed on the conductive substrate, and a photosensitive layer that is disposed on the undercoating layer, in which the undercoating layer contains at least one perinone compound selected from the group consisting of a compound represented by Formula (1) and a compound represented by Formula (2) which are shown below, and polyurethane, contains at least one perinone compound selected from the group consisting of the compounds represented by Formulas (1) and (2), and at least one acceptor compound selected from the group consisting of compounds represented by Formula (3) to (15) which are shown in the specification, or contains a resin obtained by polymerizing a diallyl phthalate compound and a charge transporting material.

Abstract: Provided is an electrophotographic photosensitive member that can achieve both of the suppression of a fluctuation in potential of the photosensitive member at the time of its repeated use, and the prevention of the occurrence of a black spot-like image defect at high levels. The electrophotographic photosensitive member includes in this order: a support; an intermediate layer; and a photosensitive layer, the intermediate layer containing particles each containing titanium oxide, and the particles having a mass increase ratio of 0.005% or more when heated under a nitrogen atmosphere from 300° C. to 900° C.

Abstract: A toner comprising a toner particle having a binder resin and a colorant, and metal titanate fine particles, wherein the toner particle includes a polyvalent metal element having an electric resistivity of from 2.5×10?8 ?·m to 10.0×10?8 ?·m; the amount of the polyvalent metal element in the toner particle is from 0.080 ?mol/g to 20.000 ?mol/g; the metal titanate fine particles have a perovskite crystal structure; and the number average particle diameter of primary particles of the metal titanate fine particles is from 10 nm to 80 nm.

Abstract: Provided is a toner has a toner particle containing a binder resin and is characterized in that the binder resin contains a polymer A, which is a polymer of a composition containing a first polymerizable monomer, a second polymerizable monomer and a crosslinking agent, the first polymerizable monomer is at least one monomer selected from the group consisting of (meth)acrylic acid esters having an alkyl group with 18 to 36 carbon atoms, the crosslinking agent has two or more polymerizable double bonds, a content of the first polymerizable monomer in the composition is 5.0 to 60.0 mol %, a content of the second polymerizable monomer is 20.0 to 95.0 mol %, and when the SP values of the first polymerizable monomer, the second polymerizable monomer and the crosslinking agent are denoted by SP12, SP22 and SPC2, respectively, the formulae 0.60?(SP22?SP12)?15.00 and SP12<SPC2<(SP22+3.00) are satisfied.

Abstract: A toner contains at least a crystalline polyester resin and an amorphous linear polyester resin that uses diethylene glycol as an alcohol component, and a monoester wax and a montan ester wax as release agent components, wherein 6???8 and 14?mw/?<30 are satisfied, where ? represents an amount of the crystalline polyester resin added relative to 100 parts by weight of the amorphous linear polyester resin and mw represents an amount of the montan ester wax added.

Abstract: An overcoat layer for an organic photoconductor drum includes a curable composition having about 20 to about 80 percent by weight of a charge transport molecule containing four radical polymerizable functional groups as exemplified below: where R1 and R2 contain a spacer group and a radical polymerizable functional group, R3 and R4 are hydrogen atoms, and R5 and R6 contain a spacer group and a radical polymerizable functional group. The curable composition may also include a non-radical polymerizable additive, such as a surfactant, and/or a curing agent.

Abstract: The present invention provides an electrophotographic photosensitive member sequentially including: a support; a photosensitive layer; and a protection layer formed on the support, wherein the protection layer has a triarylamine structure and a specific cyclic structure, and a specific A-value obtained by measurement using total reflection Fourier transform infrared spectroscopy is 0.010 or more and 0.050 or less.

Abstract: A method of preparing an organic photoconductor drum having a protective overcoat on its outermost surface is provided. In an example embodiment, a photoconductor drum having an electrically conductive substrate, a charge generation layer, a charge transport layer and an outermost protective overcoat layer is provided. The photoconductor drum is cured using a two-step process. The first curing step applies either ionizing irradiation, such as with an electron beam or by gamma rays or applies non-ionizing irradiation such as ultraviolet light to the photoconductor drum. A mask is sized and placed over the print area of the initially cured photoconductor drum, thereby exposing the outermost edges of the photoconductor drum. The outer edges of the masked photoconductor drum is then exposed to a second curing step using ultraviolet light irradiation.

Abstract: An improved overcoat layer for an organic photoconductor drum used in an electrophotographic image forming device is provided. The overcoat layer is prepared from a curable composition including a charge transport molecule containing four radical polymerizable hydrophilic functional groups containing an oxygen atom of the general structure shown below: wherein R1 and R2 contain a spacer group and a radical polymerizable hydrophilic functional group containing an oxygen atom, R3 and R4 are a non-radical polymerizable functional group, and R5 and R6 contain a spacer group and a radical polymerizable hydrophilic functional group containing an oxygen atom. The curable composition may also contain at least one optional curing agent. This overcoat layer improves wear resistance of the organic photoconductor drum without negatively altering the electrophotographic properties, thus protecting the organic photoconductor drum from damage and extending its service life.

Abstract: An electrophotographic photosensitive member has a surface layer that contains a polymer of a hole transport material having at least one monovalent polymerizable functional group.

Abstract: An electrostatic-image developing toner contains toner particles containing a polyester resin having an acid value of from 10 mg KOH/g to less than 15 mg KOH/g. The toner particles have a surface with an acid value in a range from 0.3% to 1.7% of the acid value of the polyester resin. The toner particles have a melt viscosity of from 1,800 Pa·s to 3,800 Pa·s at 100° C.