Abstract: Hydrophobic inorganic fine particles characterized by being a mixture of at least small-particle-diameter inorganic fine particles having an average primary particle diameter of 5 to 25 nm and having a maximum peak particle diameter of 20 nm or less and large-particle-diameter inorganic fine particles having an average primary particle diameter which is 1.5 to 100 times the average primary particle diameter of the small-particle-diameter inorganic fine particles; the mixture being a mixture having been treated in the same treating tank to subject both the small-particle-diameter inorganic fine particles and large-particle-diameter inorganic fine particles simultaneously to hydrophobic treatment.

Abstract: A toner exhibits excellent image characteristics, and also has an excellent charging property even if the toner is used in a cleaning-simultaneous-with-developing system having a direct injection charging mechanism. The toner includes toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 ?m to 12.0 ?m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 ?m to 4.0 ?m with respect to a volume-based particle diameter distribution, the medium diameter (D50) being smaller than the weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 ?m or less with respect to a volume-based particle diameter.

Abstract: Hydrophobic inorganic fine particles characterized by being a mixture of at least small-particle-diameter inorganic fine particles having an average primary particle diameter of 5 to 25 nm and having a maximum peak particle diameter of 20 nm or less and large-particle-diameter inorganic fine particles having an average primary particle diameter which is 1.5 to 100 times the average primary particle diameter of the small-particle-diameter inorganic fine particles; the mixture being a mixture having been treated in the same treating tank to subject both the small-particle-diameter inorganic fine particles and large-particle-diameter inorganic fine particles simultaneously to hydrophobic treatment.

Abstract: Hydrophobic inorganic fine particles characterized by being a mixture of at least small-particle-diameter inorganic fine particles having an average primary particle diameter of 5 to 25 nm and having a maximum peak particle diameter of 20 nm or less and large-particle-diameter inorganic fine particles having an average primary particle diameter which is 1.5 to 100 times the average primary particle diameter of the small-particle-diameter inorganic fine particles; the mixture being a mixture having been treated in the same treating tank to subject both the small-particle-diameter inorganic fine particles and large-particle-diameter inorganic fine particles simultaneously to hydrophobic treatment.

Abstract: A toner exhibits excellent image characteristics, and also has an excellent charging property even if the toner is used in a cleaning-simultaneous-with-developing system having a direct injection charging mechanism. The toner includes toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 ?m to 12.0 ?m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 ?m to 4.0 ?m with respect to a volume-based particle diameter distribution, the medium diameter (D50) being smaller than the weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 ?m or less with respect to a volume-based particle diameter.

Abstract: A developer capable of providing an excellent image without causing a charging failure even after a long-term and repeated use contains a toner particle having a binder resin and a colorant, an inorganic fine particle, and a conductive fine particle, in which a volume average particle diameter Da of the conductive fine particle and an number average primary particle diameter Db of the inorganic fine particle satisfy the expression (1) below, and a rate of liberation “a” of the conductive fine particle from the toner particle is 40 to 95% and a rate of liberation “b” of the inorganic fine particle from the toner particle is 0.1 to 5% Da?10Db.

Abstract: A toner exhibits excellent image characteristics, and also has an excellent charging property even if the toner is used in a cleaning-simultaneous-with-developing system having a direct injection charging mechanism. The toner includes toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 ?m to 12.0 ?m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 ?m to 4.0 ?m with respect to a volume-based particle diameter distribution, the medium diameter (D50) being smaller than the weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 ?m or less with respect to a volume-based particle diameter.

Abstract: A toner exhibits excellent image characteristics, and also has an excellent charging property even if the toner is used in a cleaning-simultaneous-with-developing system having a direct injection charging mechanism. The toner includes toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 ?m to 12.0 ?m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 ?m to 4.0 ?m with respect to a volume-based particle diameter distribution, the medium diameter (D50) being smaller than the weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 ?m or less with respect to a volume-based particle diameter.

Abstract: To provide a method for forming images in which the image bearing member and the toner carrying member are arranged with a gap of 100 ?m to 250 ?m, and the equation (1) and equation (2) are satisfied. (1) 22?(the frequency of the alternating current component of the alternating electric field/the peripheral speed of the toner carrying member)×the maximum electric field intensity at the time of developing?1.20. (2) 8?(the frequency of the alternating current component of the alternating electric field/the peripheral speed of toner carrying member)×(the fluidity index of Carr/the floodability index of Carr)?50. According to the method for forming images of the present invention, it is possible to obtain a high quality image without generating fog and light shielding while attaining a uniform halftone with a high image density even over long-term.

Abstract: Hydrophobic inorganic fine particles characterized by being a mixture of at least small-particle-diameter inorganic fine particles having an average primary particle diameter of 5 to 25 nm and having a maximum peak particle diameter of 20 nm or less and large-particle-diameter inorganic fine particles having an average primary particle diameter which is 1.5 to 100 times the average primary particle diameter of the small-particle-diameter inorganic fine particles; the mixture being a mixture having been treated in the same treating tank to subject both the small-particle-diameter inorganic fine particles and large-particle-diameter inorganic fine particles simultaneously to hydrophobic treatment.

Abstract: A process cartridge which is detachably mountable to a main body of an image-forming apparatus has a photosensitive member, a magnetic toner-holding section provided with a magnetic toner-carrying member which transports the toner to a developing zone, and a residual magnetic toner detector capable of detecting residual toner by a change in electrostatic capacity which is caused between electrodes provided inside the magnetic toner-holding section. The magnetic toner contains at least a binder resin and a colorant, having a weight-average particle diameter of from 6.5 &mgr;m to 15.0 &mgr;m, and having a Carr's floodability index of more than 80.

Abstract: Provided is a developer capable of providing an excellent image without causing a charging failure even after a long-term and repeated use.

Abstract: To provide a toner which exhibits excellent performances for image characteristics, and also has excellent performances for charging property even if the toner is used in a cleaning simultaneous with developing system having a direct injection charging mechanism. The toner of the present invention comprises toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 &mgr;m to 12.0 &mgr;m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 &mgr;m to 4.0 &mgr;m with respect to a volume-basis particle diameter distribution, the medium diameter (D50) being smaller than a weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 &mgr;m or less with respect to a volume-basis particle diameter.

Abstract: To provide an method for forming image in which the image bearing member and the toner carrying member are arranged with a gap of 100 &mgr;m to 250 &mgr;m; equation (1) and equation (2) are satisfied: (1) 22≦(the frequency of the alternating current component of the alternating electric field/the peripheral speed of the toner carrying member)×the maximum electric field intensity at the time of developing≦120; (2) 8≦(the frequency of the alternating current component of the alternating electric field/the peripheral speed of toner carrying member)×(the fluidity index of Carr/the floodability index of Carr)≦50. According to method for forming image of the present invention, it is possible to obtain a high quality image without generating fog and light shielding while attaining a uniform halftone with a high image density even in a long-term use.

Abstract: In a toner production process having at least a kneading step, a pulverization step using a mechanical grinding machine, and a classification step, the grinding means comprises a mechanical grinding machine having at least a rotor which is a rotator attached to the center rotating shaft and a stator which is provided around the rotor, keeping a constant gap between the stator and the rotor surface, the grinding machine being so constructed that a circular space formed by keeping the gap stands airtight, and the surface of at least one of the rotor and the stator is coated by the plating of a chromium alloy containing at least chromium carbide.

Abstract: A toner is composed of toner particles containing a binder resin and hydrocarbon wax wherein the binder resin includes a vinyl resin having carboxyl and a vinyl resin having as a partial structure a linkage formed by the reaction of carboxyl with epoxy. Each of the acid value of tetrahydrofuran-soluble matter of the toner, the acid value of the binder resin and the hydroxyl value of the hydrocarbon wax is in a specific range, and the acid value of the binder resin and the hydroxyl value of the hydrocarbon wax fulfill a specific relationship.

Abstract: A magnetic toner is formed of magnetic toner particles each comprising at least a binder resin and a magnetic iron oxide. The magnetic toner is provided with improved developing performances by realizing an appropriate surface-exposure state of the magnetic iron oxide, which is represented by a wettability characteristic in methanol/water mixture liquids of the magnetic toner such that it shows a transmittance of 80% for light at a wavelength of 780 nm at a methanol concentration in a range of 65-75% and a transmittance of 20% at a methanol concentration in a range of 66-76%.

Abstract: A dry magnetic toner is formed of magnetic toner particles comprising a binder resin and magnetic iron oxide particles. The magnetic toner is provided with excellent developing performances and transferability by controlling the presence of isolated iron-containing particles and containing a high percentage of spherical particles, the amount of which is controlled relative to the weight-average particle size of the magnetic toner and a content of particles of 3 &mgr;m or below in the magnetic toner.

Abstract: A magnetic toner is formed of magnetic toner particles each comprising at least a binder resin and a magnetic iron oxide. The magnetic toner is provided with improved developing performances by realizing an appropriate surface-exposure state of the magnetic iron oxide, which is represented by a wettability characteristic in methanol/water mixture liquids of the magnetic toner such that it shows a transmittance of 80% for light at a wavelength of 780 nm at a methanol concentration in a range of 65-75% and a transmittance of 20% at a methanol concentration in a range of 66-76%.

Abstract: A process cartridge which is detachably mountable to the main body of an image-forming apparatus has a photosensitive member, a toner-holding section and is provided with a toner-carrying member which holds therein a toner and is provided with a toner-carrying member which transports the toner to a developing zone, and a toner-residual detection means capable of detecting a toner residual by a change in electrostatic capacity which is caused between electrodes provided inside the toner-holding section. The toner contains at least a binder resin and a colorant, having a weight-average particle diameter of from 6.5 &mgr;m to 15.0 &mgr;m, and having a Carr's floodability index of more than 80.