Abstract: A process cartridge includes a seal member contacting an image bearing member upstream in the rotation direction of the image bearing member from a cleaning member and allowing the developer to move from upstream in the rotation direction from the contact part between the seal member and the image bearing to downstream from the contact part while regulating movement from downstream to upstream from the contact part. The developer has surface protrusions containing an organic silicon polymer, wherein either (i) the work function of the seal member is greater than the work function of the developer when the developer has a negative charging polarity and is smaller than the work function of the developer when the developer has a positive charging polarity, or (ii) the absolute value of the difference between the work function of the seal member and the work function of the developer is within a predetermined range.

Abstract: A image-forming apparatus includes a plurality of process cartridges each having a toner and an image bearing member, and has an intermediate transfer member, wherein the toner comprises a toner particle that contains a toner base particle and a prescribed organosilicon polymer on the surface of the toner base particle, and the organosilicon polymer forms protruded portions on the surface of the toner base particle, for the protrusions having a protrusion height H from 40 nm to 300 nm, the numerical proportion P(D/w) of protruded portions having a ratio of the protrusion diameter D to the protrusion width w in a prescribed range is at least 70 number %, and one of the plurality of process cartridges has a carbon black-containing black toner, and the weight-average particle diameter of this black toner is smaller than that of the toner present in the other process cartridges.

Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the toner particle contains a polyvalent metal compound, the polyvalent metal compound is at least one selected from the group consisting of aluminum compounds, iron compounds and magnesium compounds, a content of a metal element derived from the polyvalent metal compound in the toner particle is from 0.080 to 20.000 ?mol/g, the external additive contains an organosilicon polymer particle having a hydroxyl group, a ratio of a number-average particle diameter of the organosilicon polymer particle to a number-average particle diameter of the toner particle is from 0.0160 to 0.0650, and a content of the organosilicon polymer particle is at least 0.10 mass parts per 100.00 mass parts of the toner particle.

Abstract: Provided is a toner including a toner particle and an external additive, wherein the external additive includes a composite particle including a hydrotalcite particle covered on the surface with an organosilicon polymer fine particle, a coverage ratio of the hydrotalcite particle surface by the organosilicon polymer fine particle is from 1% to 50%, and given A (nm) as the number-average particle diameter of the primary particles of the organosilicon polymer fine particle and B (nm) as the number-average particle diameter of the primary particles of the hydrotalcite particle, the toner satisfies the following formula (I) and formula (II): A<B??(I) 20?A?350??(II).

Abstract: A toner containing: a toner particle that contains a binder resin and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the binder resin contains an amorphous resin and a crystalline polyester resin, a content of the crystalline polyester resin in the binder resin is from 5 to 30 mass %, and the crystalline polyester resin contains from 5 to 25 mass % of a component having a molecular weight of not more than 2,500.

Abstract: A toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the organosilicon polymer has a structure represented by at least one selected from the group consisting of RaSiO3/2 and Rb2SiO2/2 (wherein Ra and Rb represent organic groups), and in the number particle size distribution of the toner as measured within a particle size range of from 2 to 60 ?m, the number-average particle diameter T-D50n at which the accumulation from the smallest diameter is 50% is from 6 to 12 ?m, the number ratio of toner 4 ?m or less in size is from 2% to 5% of the total toner, and the number ratio of toner 3 ?m or less in size as a percentage of the total toner 4 ?m or less in size is from 25% to 50%.

Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the external additive contains composite particles of an organosilicon polymer fine particle and a fatty acid metal salt.

Abstract: Provided is a toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an external additive A and an external additive B, the external additive A is an organosilicon polymer fine particle, the number-average particle diameter of primary particles of the organosilicon polymer fine particle is from 30 to 300 nm, the external additive B is a silica fine particle, the number-average particle diameter of primary particles of the silica fine particle is from 100 to 300 nm, the fixing rate of the external additive A to the toner particle according to a water washing method is less than 30%, and the fixing rate of the external additive B to the toner particle according to the washing method is at least 30%.

Abstract: A toner comprising a toner particle that contains a toner base particle and an organosilicon polymer on a surface of the toner base particle, wherein the organosilicon polymer forms protruded portions with a prescribed structure on the surface of the toner base particle, and in the toner cross section, when the protrusion width w is the length of the segment where a protruded portion and the toner base particle form a continuous interface, the protrusion diameter D is the maximum length of a protruded portion, and the protrusion height H is the length from the peak of the protruded portion to the line along the circumference of the toner base particle surface, the numerical proportion of these protruded portions having a ratio D/w of the protrusion diameter D to the protrusion width w from 0.33 to 0.80, is a least 70 number %.

Abstract: A toner comprising a toner particle that contains a binder resin and a wax; in a microcompression test under a maximum load condition of 1.1×10?3 N, a force applied to the toner particle when a percentage deformation of the toner particle with reference to a number-average particle diameter of the toner particle at 25° C. reaches 15% is 0.10 to 1.00 mN and the force applied to the toner particle when the percentage deformation at 45° C. reaches 15% is 0.10 to 0.40 mN; and when the force applied to the toner particle is a variable and the percentage deformation of the toner particle is from 15 to 30%, the rate of increase in the percentage deformation of the toner particle at 25° C. and the rate of increase in the percentage deformation of the toner particle at 45° C. satisfy specific formula.

Abstract: A toner comprising a toner particle that contains a toner base particle and an organosilicon polymer on a surface of the toner base particle, wherein the organosilicon polymer forms protruded portions with a prescribed structure on the surface of the toner base particle, and in the toner cross section, when the protrusion width w is the length of the segment where a protruded portion and the toner base particle form a continuous interface, the protrusion diameter D is the maximum length of a protruded portion, and the protrusion height H is the length from the peak of the protruded portion to the line along the circumference of the toner base particle surface, the numerical proportion of these protruded portions having a ratio D/w of the protrusion diameter D to the protrusion width w from 0.33 to 0.80, is a least 70 number %.

Abstract: A image-forming apparatus includes a plurality of process cartridges each having a toner and an image bearing member, and has an intermediate transfer member, wherein the toner comprises a toner particle that contains a toner base particle and a prescribed organosilicon polymer on the surface of the toner base particle, and the organosilicon polymer forms protruded portions on the surface of the toner base particle, for the protrusions having a protrusion height H from 40 nm to 300 nm, the numerical proportion P(D/w) of protruded portions having a ratio of the protrusion diameter D to the protrusion width w in a prescribed range is at least 70 number %, and one of the plurality of process cartridges has a carbon black-containing black toner, and the weight-average particle diameter of this black toner is smaller than that of the toner present in the other process cartridges.