Abstract: Provided are a process cartridge and an electrophotographic apparatus each of which is reduced in fogging for reducing a toner consumption. Specifically, provided is a process cartridge, which is removably mounted onto a main body of an electrophotographic apparatus, the process cartridge including: a developing unit containing a toner; and an electrophotographic photosensitive member, wherein the toner is a toner including a toner particle, and has a polyvalent acid metal salt on at least part of a surface of the toner particle, wherein the polyvalent acid metal salt includes at least one kind of metal element selected from metal elements belonging to from Group 3 to Group 13, and wherein a surface layer of the electrophotographic photosensitive member contains a resin including a siloxane segment.

Abstract: In an image forming apparatus, a fixing member has a surface layer having conductivity. A developer is a toner having a toner particle including a binder resin, a reactant of a polyhydric acid and a compound containing a group 4 element is present on a surface of the toner particle, and Tv/Fv>100 is satisfied where Tv represents a volume resistivity upon being unfixed, and Fv represents a volume resistivity after fixing. A bias applying unit can selectively apply a bias of a positive polarity and a bias of a negative polarity, and applies a bias of the same polarity as the charged polarity of a filler included in a recording material when the recording material passes through a fixing nip portion, and when the recording material does not pass through the fixing nip portion, respectively.

Abstract: A toner comprising a toner particle, wherein the toner particle includes a binder resin, where a volume resistivity ?·cm of an unfixed solid image on a recording material on which the solid image has been formed using the toner at a toner laid-on level of 0.4 mg/cm2 is denoted by Tv, and a volume resistivity ?·cm of the solid image after fixing by applying heat and pressure to the recording material is denoted by Fv, Tv/Fv?8 is satisfied.

Abstract: A toner including a toner particle, wherein the toner particle includes a toner base particle containing a binder resin, and a shell on the surface of the toner base particle; the shell contains a metal compound and an organosilicon polymer; the shell has at least an exposed portion of the metal compound and an exposed portion of the organosilicon polymer, on the surface of the toner particle; and in an analysis of a cross section of the toner particle by TEM-EDX, Ha (nm) and Hb (nm) which are average distances from the interface of the toner base particle and the shell up to the toner particle surface at the exposed portion of the metal compound and at the exposed portion of the organosilicon polymer, respectively, on the toner particle surface, satisfy Expression (1) below: Hb>Ha+20.0??(1).

Abstract: A toner comprising a toner particle, wherein the toner particle includes a toner base particle containing a binder resin and includes a protruded portion on a surface of the toner base particle; the protruded portion comprises an organosilicon polymer and a polyhydric acid metal salt; and the polyhydric acid metal salt is present on a surface of the protruded portion.

Abstract: Provided is a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including: a developing unit including a toner; and an electrophotographic photosensitive member, wherein the toner includes a toner particle, the toner particle has a surface containing a polyvalent acid metal salt particle, and a surface layer of the electrophotographic photosensitive member contains at least one metal oxide particle among an aluminum oxide particle, a silicon dioxide particle, and a tin oxide particle.

Abstract: A toner comprising a toner particle, wherein the toner has G1 of from 5.0×10?13 to 1.0×10?10, and a ratio G2/G1 of G2 to G1 is from 0.10 to 0.60, when a conductivity of the toner measured at a frequency of 0.01 Hz under a pressure of 1,000 kPa is designated by G1 in S/m, and a conductivity of the toner measured at a frequency of 0.01 Hz under a pressure of 100 kPa is designated by G2 in S/m.

Abstract: A toner comprising a toner particle, wherein the toner particle includes a binder resin, where a volume resistivity ?·cm of an unfixed solid image on a recording material on which the solid image has been formed using the toner at a toner laid-on level of 0.4 mg/cm2 is denoted by Tv, and a volume resistivity ?·cm of the solid image after fixing by applying heat and pressure to the recording material is denoted by Fv, Tv/Fv?8 is satisfied.

Abstract: The present disclosure provides a process cartridge and an electrophotographic apparatus in which fogging is reduced so as to reduce an amount of toner consumed. A process cartridge configured to be detachably attachable to a main body of an electrophotographic apparatus includes a developing unit containing a toner, and an electrophotographic photosensitive member, wherein the toner is a toner that has a toner particle, and has a metal salt of a polyvalent acid at least on a part of a surface of the toner particle; wherein the metal salt of the polyvalent acid includes at least one kind of metal element selected from metal elements belonging to from Group 3 to Group 13, and a surface layer of the electrophotographic photosensitive member contains an acrylic resin or a methacrylic resin.

Abstract: Provided are a process cartridge and an electrophotographic apparatus each of which is reduced in fogging for reducing a toner consumption. Specifically, provided is a process cartridge, which is removably mounted onto a main body of an electrophotographic apparatus, the process cartridge including: a developing unit containing a toner; and an electrophotographic photosensitive member, wherein the toner is a toner including a toner particle, and has a polyvalent acid metal salt on at least part of a surface of the toner particle, wherein the polyvalent acid metal salt includes at least one kind of metal element selected from metal elements belonging to from Group 3 to Group 13, and wherein a surface layer of the electrophotographic photosensitive member contains a resin including a siloxane segment.

Abstract: A toner containing a toner particle, wherein, when a dielectric loss tangent measured at a frequency of 10 kHz in an impedance measurement on the toner in an environment having a temperature of 50° C. and a relative humidity of 50% RH is designated by tan ?50° C.(1), and a dielectric loss tangent measured at a frequency of 10 kHz in an impedance measurement on the toner in an environment having a temperature of 30° C. and a relative humidity of 50% RH after the impedance measurement on the toner in an environment having a temperature of 50° C. and a relative humidity of 50% RH is designated by tan ?30° C.(2), tan ?50° C.(1) is from 0.015 to 0.050, the relationship tan ?50° C.(1)>tan ?30° C.(2) is satisfied, and tan ?30° C.(2)/tan ?50° C.(1) is from 0.25 to 0.66.

Abstract: A toner including a toner particle, wherein the toner particle includes a toner base particle containing a binder resin, and a shell on the surface of the toner base particle; the shell contains a metal compound and an organosilicon polymer; the shell has at least an exposed portion of the metal compound and an exposed portion of the organosilicon polymer, on the surface of the toner particle; and in an analysis of a cross section of the toner particle by TEM-EDX, Ha (nm) and Hb (nm) which are average distances from the interface of the toner base particle and the shell up to the toner particle surface at the exposed portion of the metal compound and at the exposed portion of the organosilicon polymer, respectively, on the toner particle surface, satisfy Expression (1) below:

Abstract: A toner including: a toner particle including a toner base particle containing a binder resin, and an organosilicon condensate present on a surface of the toner base particle, wherein a charge attenuation constant of the toner is 3.5×10?3 or more to 1.0×100 or less.

Abstract: The toner has a toner particle in which a toner core containing a binder resin is coated with a shell layer, wherein the binder resin contains a polymer A that has a first monomer unit and a second monomer unit; the first unit is derived from (meth)acrylate ester having an alkyl group having 18 to 36 carbon atoms; the content of the first monomer unit in the polymer is 5.0 to 60.0 mol %; the content of the second monomer unit is 20.0 to 95.0 mol %; the following formula (1) is satisfied when the SP value of the first unit is denoted by SP11 and the SP value of the second unit is denoted by SP21; and the toner core is coated with a highly uniform shell over at least 90% of the circumference of the toner cross section; 3.00?(SP21?SP11)?25.00??(1).

Abstract: A toner, including a toner particle that contains a binder resin and a release agent, wherein the binder resin contains a polymer A, the polymer A including 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 (meth)acrylic acid esters having a C18-36 alkyl group; the toner has a first monomer unit content and a second monomer unit content in the polymer A which are within specific ranges, and assuming that an SP value of the first monomer unit is taken as SP11 and an SP value of the second monomer unit is taken as SP21, the formula (1) below is satisfied, and the molecular weight of the release agent is at least 1,000. 3.00?(SP21?SP11)?25.

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: 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 having a toner particle having a plurality of fine particles on the surface of a toner base particle, the toner base particle contains a binder resin, wherein a fine particle layer A constituted of a plurality of the fine particles is observed in an EDX mapping image of the constituent elements in a cross section of the toner particle as provided by EDX of the toner particle cross section observed using TEM; a fine particle B, containing a metal compound containing at least one metal element M selected from all the metal elements belonging to Groups 3 to 13, is observed in the fine particle layer A; and the number-average particle diameter D of the fine particle B, the average value H of the thickness of the fine particle layer A, and the standard deviation S on the thickness of the fine particle layer A satisfy prescribed relationships.

Abstract: Provided is a toner, including a toner particle having: a toner base particle containing a binder resin and a colorant; and protrusion derived from a resin fine particle in a surface of the toner base particle, wherein the protrusion is covered with a condensation product of an organosilicon compound represented by the formula (1), and wherein the resin fine particle is in direct contact with the toner base particle.

Abstract: A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0×10?4 N, of from 200 MPa to 1,100 MPa.