Patent classifications
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
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.