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: A toner comprising a toner particle, the toner particle comprising: a binder resin and a wax; wherein the toner particle has a toner core particle and a protrusion present on the surface of the toner core particle, the protrusion comprises an organosilicon polymer, where in cross-sectional observation of the toner particle, a line segment connecting both ends of an interface between the toner core particle and the protrusion is defined as a reference line, and the length of the reference line is denoted by W (nm), and a maximum length of the protrusion in the toner core particle direction from the reference line in the normal direction of the reference line is defined as a maximum penetration depth I (nm), W and I satisfy I/W?0.050, and Young's modulus of the protrusion E1 is 1.00 to 3.90 GPa.

Abstract: A toner comprising a toner particle, wherein the toner particle comprises a toner core particle, and the toner core particle comprises a binder resin; the binder resin comprises a resin A; the resin A comprises a monomer unit M1 having a specific structure in a specific amount, and a monomer unit M2 comprising an organosilicon polymer segment in a specific amount; the organosilicon polymer segment has a T3 unit structure and a T2 unit structure; in a DD/MAS measurement of the resin A by solid-state 29Si-NMR, a proportion of a peak area corresponding to a silicon atom with the T3 unit structure, and a proportion of a peak area corresponding to a silicon atom with the T2 unit structure satisfy a specific relationship; and the weight-average molecular weight Mw of a tetrahydrofuran-soluble fraction of the resin A lies within a specific range.

Abstract: A toner comprising a toner particle, wherein the toner particle comprises a binder resin and wax, and where with respect to a slope X of a straight line obtained by performing a micro-compression test on the toner, obtaining a relationship of a deformation amount (?m) to a load (mN), calculating a percentage deformation (%), which is a ratio of the deformation amount to a particle diameter of the particle measured, plotting a load (mN)?percentage deformation (%) plot, and then using all the points plotted within the range in which the percentage deformation was 15% or less of the particle diameter of the particle for approximation by a least squares method, the slope X measured at 30° C. is denoted by X30 and the slope X measured at 45° C. is denoted by X45, the X30 is 25 to 300, and the X45 is 400 to 1000.

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 resin A, and an external additive A, wherein the resin A is a resin represented by formula (1) below, the resin A is present at the surface of the toner particle, the external additive A is a fine particle containing silicon, the average value of the shape factor SF-1 of the external additive A is from 105 to 120, the average value of the shape factor SF-2 of the external additive A is from 100 to 130.

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, 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 particle has a core-shell structure comprising a core particle and a shell on a surface of the core particle, the shell comprises a polymer having monomer units represented by Formula (I) below, the toner comprises a specific external additive A, the external additive A is at least one selected from the group consisting of silica fine particles and organosilicon polymer fine particles, and a ratio of coverage of a surface of the toner particle with the external additive A is 0.3 area % or higher: in Formula (I), L1 represents —COO(CH2)n— (where n is an integer of 1 to 10), and carbonyl of L1 is bonded to a carbon atom of a main chain; R1 represents hydrogen or a methyl group; and R2 to R10 represent each independently an alkyl group having 1 to 4 carbon atoms.

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: 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 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: 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: A toner comprises a toner particle comprising a resin A and a resin B, wherein the resin A has a structure represented by a predetermined general formula, and the resin B has a monomer unit represented by a predetermined general formula, and a toner manufacturing method comprises a step of dispersing a toner base particle comprising the resin B in an aqueous medium to obtain a toner slurry, and a step of adding a radical polymerization initiator and a monomer composition comprising a monomer represented by a predetermined general formula to the resulting toner slurry to form the resin A on a surface of the toner base particle.

Abstract: A toner comprising a toner particle comprising a binder resin, wherein the toner particle comprises a condensation product of an organosilicon compound, in time-of-flight secondary ion mass spectrometry of the toner particle, a normalized intensity of silicon ions derived from the condensation product of the organosilicon compound is from 7.00×10?4 to 3.00×10?2, a normalized intensity of silicon ions after sputtering the toner particle under a specific condition is 6.99×10?4 or lower, the toner comprises a fine particle on the surface of the toner particle, and the fine particle has at least one selected from the group consisting of a specific fine particle of a polyhydric acid metal salt, a strontium titanate fine particle, a titanium oxide fine particle and an aluminum oxide fine particles.

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: 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.