Patent classifications
G03G9/1132
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 coating resin layer coating the magnetic particle and containing inorganic particles, in which an area ratio of the inorganic particles that is a ratio of a total area of the inorganic particles to an area of the coating resin layer in a cut surface of the coating resin layer along a thickness direction of the coating resin layer is 10% or more and 50% or less.
ELECTROSTATIC CHARGE IMAGE DEVELOPER, DEVELOPER CARTRIDGE, AND PROCESS CARTRIDGE
An electrostatic charge image developer includes an electrostatic charge image developing toner that includes toner particles, and an external additive which is added to the toner particles and which includes silica particles whose compression aggregation degree is from 60% to 95% and particle compression ratio is from 0.20 to 0.40, and a carrier for developing an electrostatic charge image that includes a core particle and a resin coated layer which covers a surface of the core particle and that has a surface roughness Ra (based on JIS-B0601) of 0.5 μm or less and a circularity of 0.975 or more.
ELECTROSTATIC IMAGE DEVELOPING TONER, ELECTROSTATIC IMAGE DEVELOPER AND TONER CARTRIDGE
An electrostatic image developing toner contains: toner particles, first silica particles having an average equivalent circle diameter of 10 nm to 120 nm and second silica particles having a compressive agglomeration degree of 60% to 95%, a particle compression ratio of 0.20 to 0.40 and an average equivalent circle diameter being greater than the average equivalent circle diameter of the first silica particles.
Electrostatic charge image developing toner, electrostatic charge image developer, and toner cartridge
An electrostatic charge image developing toner includes toner particles having a volume average particle diameter of 3 μm to 16 μm, wherein, when the toner particles having a particle diameter of 1.0 μm to 30.0 μm are set as T1, the toner particles having a particle diameter of 1.0 μm to 2.5 μm are set as T2, a rate of T2 to the toner particles is set as A, the toner particles having a particle diameter of 1.0 μm to 5 μm is set as T3 and a rate of T3 to the toner particles is set as B, the rate of T2 occupying T1 is from 10% by number to 40% by number and a fine particle ratio C represented by A/B is from 0.18 to 0.40.
Electrostatic charge image developer, developer cartridge, and process cartridge
An electrostatic charge image developer includes an electrostatic charge image developing toner that includes toner particles, and an external additive which is added to the toner particles and which includes silica particles whose compression aggregation degree is from 60% to 95% and particle compression ratio is from 0.20 to 0.40, and a carrier for developing an electrostatic charge image that has a core including a magnetic member in a binder resin for a core and a coating layer which coders a surface or the core and which includes a resin for a coating layer and has a surface roughness Ra of from 0.25 μm to 0.4 μm.
ELECTROSTATIC CHARGE IMAGE DEVELOPING CARRIER, METHOD OF PREPARING ELECTROSTATIC CHARGE IMAGE DEVELOPING CARRIER, AND ELECTROSTATIC CHARGE IMAGE DEVELOPER
An electrostatic charge image developing carrier includes magnetic particles and a resin coating layer which covers the magnetic particles, wherein a sulfate ion concentration of the resin coating layer is 0.05% by weight or less with respect to a total weight of the resin coating layer, and when a total value of a molar amount of sulfate ions contained and a molar amount of sulfo groups contained per 1 g of the resin coating layer is A mol and a molar amount of sodium ions contained per 1 g of the resin coating layer is B mol, a relationship of 0.1<B/A<1.2 is satisfied.
FERRITE PARTICLES, ELECTROPHOTOGRAPHIC DEVELOPER CARRIER CORE MATERIAL, ELECTROPHOTOGRAPHIC DEVELOPER CARRIER, AND ELECTROPHOTOGRAPHIC DEVELOPER
The present invention relates to a ferrite particle, containing a crystal phase component containing a perovskite crystal represented by the compositional formula:
RZrO.sub.3 (provided that R represents an alkaline earth metal element), and having an apparent density in a range represented by the following formula:
1.90≤Y≤2.45
provided that Y in the formula is the apparent density (g/cm.sup.3) of the ferrite particle.
FERRITE PARTICLE, CARRIER CORE MATERIAL FOR ELECTROPHOTOGRAPHIC DEVELOPER, CARRIER FOR ELECTROPHOTOGRAPHIC DEVELOPER, AND ELECTROPHOTOGRAPHIC DEVELOPER
The present invention relates to a ferrite particle containing a crystal phase component containing a perovskite-type crystal represented by a composition formula of RZrO3 (wherein R is an alkaline earth metal element), and a Mg content of 0.45 mass % or less. The present invention also relates to a carrier core material for an electrophotographic developer, containing the ferrite particle; a carrier for an electrophotographic developer, containing the ferrite particle and a resin coating layer provided on a surface of the ferrite particle; and an electrophotographic developer containing the carrier for an electrophotographic developer and a toner.
CARRIER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE AND METHOD FOR PRODUCING THE SAME, ELECTROSTATIC CHARGE IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD
A carrier for developing an electrostatic charge image includes magnetic particles and a resin coating layer covering the magnetic particles, the resin coating layer containing aggregates of inorganic particles. The arithmetic mean diameter of the aggregates of inorganic particles on the carrier surface is 30 nm or more and 150 nm or less, and the percentage surface exposure of the magnetic particles is 0% by area or more and 5% by area 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.