G03G9/107

TONER AND TWO-COMPONENT DEVELOPER

A toner includes a toner particle containing a binder resin containing a crystalline polyester. In differential scanning calorimetry (DSC), the toner is heated to 180° C. at a rate of 10° C./min, then cooled to 25° C. at a rate of 10° C./min and successively from 25° C. to 15° C. at a rate of 3° C./min, and heated again to 180° C. at a rate of 10° C./min. As a result, an exothermic amount P1 when the toner is cooled from 80° C. to 40° C. is 1.00 J/g or less, an exothermic amount P2 when the toner is cooled from 25° C. to 15° C. is 0.10 J/g or more, and when a sum of endothermic amounts P3 (J/g) when the toner is heated again from 40° C. to 180° C. and a sum of exothermic amounts P4 (J/g) when the toner is cooled from 180° C. to 40° C. satisfies 2.0 ≤ P3-P4 ≤ 10.0.

Toner and two-component developer

A toner having: a toner particle containing a binder resin including a first resin and a second resin; and an inorganic fine particle on a surface of the toner particle, wherein the first resin has a specific content ratio of a specific monomer unit, acid values of the first unit and second unit are within specific ranges, a domain matrix structure including a matrix containing the first resin and domains containing the second resin appears in cross-sectional observation of the toner, a compound having an alkyl group is present on a surface of the inorganic fine particle, and a volume resistivity of the inorganic fine particle is 1.0×10.sup.5 Ω.Math.cm to 1.0×10.sup.13 Ω.Math.cm.

Toner and two-component developer

A toner having: a toner particle containing a binder resin including a first resin and a second resin; and an inorganic fine particle on a surface of the toner particle, wherein the first resin has a specific content ratio of a specific monomer unit, acid values of the first unit and second unit are within specific ranges, a domain matrix structure including a matrix containing the first resin and domains containing the second resin appears in cross-sectional observation of the toner, a compound having an alkyl group is present on a surface of the inorganic fine particle, and a volume resistivity of the inorganic fine particle is 1.0×10.sup.5 Ω.Math.cm to 1.0×10.sup.13 Ω.Math.cm.

Ferrite carrier core material for electrophotographic developer, ferrite carrier, manufacturing method thereof, and electrophotographic developer using said ferrite

The present invention provides: a ferrite carrier core material for an electrophotographic developer, the material having a mesh passing amount of 3 wt % or less as indicated by the ratio of the weight of particles passing through a 16 μm-mesh to the weight of whole particles constituting a powder, and having a particle strength index of 2 wt % or less as indicated by a difference between the mesh passing amounts before and after crushing; a ferrite carrier which is for an electrophotographic developer and in which the surface of the ferrite carrier core material is coated with a resin; and an electrophotographic developer which includes the ferrite carrier and a toner.

CARRIER FOR FORMING ELECTROPHOTOGRAPHIC IMAGE, DEVELOPER FOR FORMING ELECTROPHOTOGRAPHIC IMAGE, ELECTROPHOTOGRAPHIC IMAGE FORMING METHOD, ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS, AND PROCESS CARTRIDGE

A carrier can be used for forming an electrophotographic image. The carrier contains a core particle and a coating layer coating the core particle. The coating layer contains a chargeable particle. The carder has an internal void ratio of 0.0% or greater but less than 2.0%, and an apparent density of 2.0 g/cm.sup.3 or greater but less than 2.5 g/cm.sup.3.

ELECTROSTATIC CHARGE IMAGE DEVELOPING CARRIER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

An electrostatic charge image developing carrier contains a magnetic particle and a resin coating layer coating the magnetic particle, in which the resin coating layer contains inorganic particles, a ratio B/A of a surface area B of the carrier to a plan view area A of the carrier that are obtained by three-dimensional analysis of a surface of the carrier is 1.020 or more and 1.100 or less, a volume average particle diameter of the magnetic particle is 25 μm or more and 34 μm or less, and a fluidity of the magnetic particle is 28 s/50 g or more and 36 s/50 g or less.

ELECTROSTATIC CHARGE IMAGE DEVELOPING CARRIER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

An electrostatic charge image developing carrier contains a magnetic particle and a resin coating layer coating the magnetic particle, in which the resin coating layer contains inorganic particles, a ratio B/A of a surface area B of the carrier to a plan view area A of the carrier that are obtained by three-dimensional analysis of a surface of the carrier is 1.020 or more and 1.100 or less, a volume average particle diameter of the magnetic particle is 25 μm or more and 34 μm or less, and a fluidity of the magnetic particle is 28 s/50 g or more and 36 s/50 g or less.

ELECTROSTATIC CHARGE IMAGE DEVELOPING CARRIER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD

An electrostatic charge image developing carrier, containing: a magnetic particle; and a resin coating layer that coats the magnetic particle and contains inorganic particles, and the electrostatic charge image developing carrier has a surface of a surface roughness satisfying a ratio B/A of a surface area B to a plan view area A of 1.020 or more and 1.100 or less, the plan view area A and the surface area B being obtained by three-dimensional analysis of the surface, and the magnetic particle has a surface roughness satisfying 0.5 μm≤Sm≤2.5 μm and 0.3 μm≤Ra≤1.2 μm, and Sm represents an average ruggedness interval and Ra represents an arithmetic average surface roughness.

FERRITE PARTICLES, ELECTROPHOTOGRAPHIC DEVELOPER CARRIER CORE MATERIAL, ELECTROPHOTOGRAPHIC DEVELOPER CARRIER, AND ELECTROPHOTOGRAPHIC DEVELOPER
20220155701 · 2022-05-19 · ·

The present invention provides: a ferrite particle containing a crystal phase component containing a perovskite crystal represented by the compositional formula RZrO.sub.3 (where R is an alkaline earth metal element); and an electrophotographic developer carrier core material, an electrophotographic developer carrier, and an electrophotographic developer containing the ferrite particles.

Image forming method

Provided is an image forming method, including: transferring and fixing a toner onto a recording medium, and forming an image including a plurality of layers, in which an attachment amount of the toner on the recording medium is greater than or equal to 8 g/m.sup.2 and less than or equal to 40 g/m.sup.2, a toner forming a layer in contact with a fixing member contains at least a first mold release agent containing ester wax and a second mold release agent containing microcrystalline wax, and a special color toner is contained in any layer of the plurality of layers.