Abstract: 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.

Abstract: 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.

Abstract: A process cartridge that is detachable from a main body of an electrophotographic apparatus, in which a surface protective layer of an electrophotographic photosensitive member contains an electroconductive particle; the content of the electroconductive particle is 20.0 to 70.0% by volume of the surface protective layer; the surface protective layer has a volume resistivity of 1.0×109 to 1.0×1014 ?·cm; a toner particle has at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron; and a total content of the multivalent metal elements in the toner particle, as measured by coupled induction plasma atomic emission spectrometry (ICP-AES), is 0.10 to 1.25 ?mol/g.

Abstract: 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.

Abstract: A toner comprising: a toner particle comprising a binder resin; and an external additive on a surface of the toner particle, wherein the binder resin comprises a resin having an ester bond, a peak corresponding to boric acid is detected in ATR-IR analysis of the toner particle in an ATR method using germanium as an ATR crystal, and when a dispersed solution obtained by dispersing the toner in an aqueous solution containing a surfactant is subjected to a detachment treatment A including shaking for 300 seconds using a shaker, and when an external additive detached from the toner by the detachment treatment A is denoted as external additive A, a charge amount of the external additive A using a standard carrier (F81) is ?0.5 ?C/g or less.

Abstract: A toner comprising a toner particle comprising a binder resin and boric acid, wherein the toner has an average circularity of 0.95 or more, and the toner has a shape factor SF1 of 105 to 125, and a method for producing to provide a toner with excellent durability for which the improvement of transfer rate with the above physical characteristics.

Abstract: A toner comprising a toner particle comprising a binder resin, a crystalline material A, and a crystalline material B, wherein the binder resin contains a resin M in an amount of 70 mass % or more relative to the binder resin, the crystalline material A has a melting point of 50.0° C. to 100.0° C., and when, the difference between the SP value of the resin M and material A is designated as ?SPAM, the difference between the SP value of the resin M and crystalline material B is designated as ?SPBM, the difference between the SP value of the crystalline material A and crystalline material B is designated as ?SPAB, the peak molecular weight of the crystalline material A and crystalline material B is designated as MpA and MpB each, the formulae (1) to (3) are satisfied: 50?MpB×?SPBM2?MpA×?SPAM2?450??(1) MpA×?SPAM2?800??(2) ?SPAB?0.

Abstract: A toner comprising a toner particle that comprises a core particle comprising a binder resin and a surface layer comprising inorganic fine particles and an organosilicon polymer, wherein the organosilicon polymer has T3 structure represented by R—Si(O1/2)3, in 29Si-NMR measurement of THF insoluble-matter of the toner particle, a proportion of a peak area assigned to the T3 structure relative to a total peak area for the organosilicon polymer is at least 5.0%, and in observation of a cross section of the toner particle using TEM, the toner has a prescribed surface layer thickness, a prescribed number of inorganic fine particles in contact with the core particle in the surface layer, and a prescribed number of inorganic fine particles present in the core particle and not in contact with the surface layer.

Abstract: A toner comprising a toner particle containing a binder resin, the storage elastic modulus Gt? (150) of the toner at 150° C. is at least 1.0×104 Pa, 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 different from the first polymerizable monomer, the first polymerizable monomer is selected from specific (meth)acrylic acid esters, the contents of the first monomer unit and second monomer unit in the polymer A are within specific ranges, and the SP values of the first monomer unit and second monomer unit are within specific ranges.

Abstract: A toner including a toner particle containing a binder resin, wherein the binder resin contains a crystalline resin, and in viscoelasticity measurement of the toner with Tp being a peak temperature of an endothermic peak derived from the crystalline resin in DSC of the toner, given G?(Tp?5, 0.01 Hz) as a storage modulus at a temperature of Tp?5° C. and a frequency of 0.01 Hz, G?(Tp?5, 10 Hz) as a storage modulus at a temperature of Tp?5° C. and a frequency of 10 Hz, and G?(Tp?30, 10 Hz) as a storage modulus at a temperature of Tp?30° C. and a frequency of 10 Hz, the following formulae are satisfied: G?(Tp?30,10 Hz)/G?(Tp?5,0.01 Hz)?1.40 G?(Tp?5,10 Hz)/G?(Tp?5,0.01 Hz)?2.20.

Abstract: Provided is a magnetic toner having a toner particle containing a binder resin and a magnetic body, wherein the binder resin contains a polymer A having a first monomer unit and a second monomer unit, the first polymerizable monomer is at least one selected from the group consisting of the (meth)acrylic acid esters having C18-36 alkyl groups, a content of the first monomer unit and a content of the second monomer unit based on the total moles of all monomer units in the polymer A are respectively 5.0 to 60.0 mol % and 20.0 to 95.0 mol %, and assuming that an SP value of the first monomer unit and the second monomer unit are taken as SP11 (J/cm3)0.5 and SP21(J/cm3)0.5, respectively, 3.00?(SP21?SP11)?25.00 is satisfied, and an oil absorption of the magnetic body is 5 to 40 ml/100 g.

Abstract: According to an embodiment, a coating apparatus includes an application head, a first moving device, a second moving device, a feeding device, and a suction device. The application head is opposed to a coating surface of a target with a predetermined distance, and forms a meniscus pillar of a coating material between the application head and the coating surface. The first moving device moves the application head. The second moving device moves the application head. The feeding device feeds the coating material between the application head and the coating surface of the target. The suction device sucks the coating material. A distance between the application head and the coating surface is made greater than the predetermined distance, and the coating material is sucked from the meniscus pillar by the suction device.

Abstract: A toner including a toner particle containing a binder resin, wherein the binder resin contains a crystalline resin, and in viscoelasticity measurement of the toner with Tp being a peak temperature of an endothermic peak derived from the crystalline resin in DSC of the toner, given G?(Tp—5, 0.01 Hz) as a storage modulus at a temperature of Tp—5° C. and a frequency of 0.01 Hz, G?(Tp—5, 10 Hz) as a storage modulus at a temperature of Tp—5° C. and a frequency of 10 Hz, and G?(Tp—30, 10 Hz) as a storage modulus at a temperature of Tp—30° C. and a frequency of 10 Hz, the following formulae are satisfied: G?(Tp—30,10 Hz)/G?(Tp—5,0.01 Hz)?1.40 G?(Tp—5,10 Hz)/G?(Tp—5,0.01 Hz)?2.20.

Abstract: Provided is an external additive having a resin particle containing a crystalline resin, and an inorganic fine particle containing a metal atom, the inorganic fine particle being embedded in the resin particle, wherein part of the inorganic fine particle being exposed on a surface of the resin particle, the maximum endothermic peak temperature of the external additive during a first temperature rise is from 50.0° C. to 120° C., the shape factor SF-2 of the external additive is from 110 to 150, and the external additive satisfies following formulae (1) and (2) below, in which Za (mass %) is the percentage content of a metal atom contained in the inorganic fine particle on the surface of the external additive in X-ray photoelectron spectroscopy, and Zb (mass %) is the percentage content of the metal atom in thermogravimetric analysis of the external additive, Za?15??(1), and Za/Zb?0.

Abstract: An external toner additive having a resin fine particle containing a crystalline resin and an inorganic fine particle embedded in the resin fine particle, wherein part of the inorganic fine particle is exposed on the surface of the resin fine particle, and in differential scanning calorimetry of the external toner additive, the maximum endothermic peak temperature T1 (° C.) during a first temperature increase and the maximum exothermic peak temperature T2 (° C.) during a first temperature decrease satisfy the formulae (1) to (3) below, with measurement performed between ?40° C. and 150° C. at a rate of increase of 10° C./min during the first temperature increase and between 150° C. and ?40° C. at a rate of decrease in temperature of 10° C./min during the first temperature decrease: T1-T2?40.0??(1) 50.0?T1?120.0??(2) 10.0?T2?80.0??(3).

Abstract: A toner comprising a toner particle containing a binder resin, the storage elastic modulus Gt? (150) of the toner at 150° C. is at least 1.0×104 Pa, 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 different from the first polymerizable monomer, the first polymerizable monomer is selected from specific (meth)acrylic acid esters, the contents of the first monomer unit and second monomer unit in the polymer A are within specific ranges, and the SP values of the first monomer unit and second monomer unit are within specific ranges.

Abstract: Provided is a magnetic toner having a toner particle containing a binder resin and a magnetic body, wherein the binder resin contains a polymer A having a first monomer unit and a second monomer unit, the first polymerizable monomer is at least one selected from the group consisting of the (meth)acrylic acid esters having C18-36 alkyl groups, a content of the first monomer unit and a content of the second monomer unit based on the total moles of all monomer units in the polymer A are respectively 5.0 to 60.0 mol % and 20.0 to 95.0 mol %, and assuming that an SP value of the first monomer unit and the second monomer unit are taken as SP11 (J/cm3)0.5 and SP21(J/cm3)0.5, respectively, 3.00?(SP21?SP11)?25.00 is satisfied, and an oil absorption of the magnetic body is 5 to 40 ml/100 g.

Abstract: Provided is an external additive having a resin particle containing a crystalline resin, and an inorganic fine particle containing a metal atom, the inorganic fine particle being embedded in the resin particle, wherein part of the inorganic fine particle being exposed on a surface of the resin particle, the maximum endothermic peak temperature of the external additive during a first temperature rise is from 50.0° C. to 120° C., the shape factor SF-2 of the external additive is from 110 to 150, and the external additive satisfies following formulae (1) and (2) below, in which Za (mass%) is the percentage content of a metal atom contained in the inorganic fine particle on the surface of the external additive in X-ray photoelectron spectroscopy, and Zb (mass%) is the percentage content of the metal atom in thermogravimetric analysis of the external additive, Za>15??(1), and Za/Zb?0.

Abstract: An external toner additive having a resin fine particle containing a crystalline resin and an inorganic fine particle embedded in the resin fine particle, wherein part of the inorganic fine particle is exposed on the surface of the resin fine particle, and in differential scanning calorimetry of the external toner additive, the maximum endothermic peak temperature T1 (° C.) during a first temperature increase and the maximum exothermic peak temperature T2 (° C.) during a first temperature decrease satisfy the formulae (1) to (3) below, with measurement performed between ?40° C. and 150° C. at a rate of increase of 10° C./min during the first temperature increase and between 150° C. and ?40° C. at a rate of decrease in temperature of 10° C./min during the first temperature decrease: T1-T2?40.0??(1) 50.0?T1?120.0??(2) 10.0?T2?80.0??(3).

Abstract: A toner comprising a toner particle containing a resin and a colorant, wherein, with respect to a temperature-storage elastic modulus curve obtained by powder dynamic viscoelastic measurement on the toner, (I) the relative minimum values for the variation in the storage elastic modulus E? with respect to temperature T in the temperature range of at least 30° C. and not more than 180° C. have a relative minimum value of equal to or less than ?1.00×107 and the relative minimum value on the lowest temperature side is equal to or less than ?1.00×108; (II) the storage elastic modulus E? (50) of the toner at 50° C. is at least 1.00×109 and not more than 9.00×109; and (III) for a storage elastic modulus E? (120) of the toner at 120° C., E? (50) and E? (120) satisfy 1.50?[E? (50)]/[E? (120)]?3.00.