G03G9/113

FERRITE PARTICLES, ELECTROPHOTOGRAPHIC DEVELOPER CARRIER CORE MATERIAL, ELECTROPHOTOGRAPHIC DEVELOPER CARRIER, AND ELECTROPHOTOGRAPHIC DEVELOPER
20230144641 · 2023-05-11 · ·

The present invention relates to a ferrite particle containing a crystal phase component containing a perovskite crystal represented by a compositional formula: RZrO.sub.3 (provided that R represents an alkaline earth metal element), having a surface roughness Rz of 2.0 μm or more and 4.5 μm or less, and satisfying the following formulas: 6.5≤log H.sub.1000≤8.5 and 0.80≤log H.sub.1000/log H.sub.100≤1.00. The ferrite particle can be used as an electrophotographic developer carrier core material. In addition, an electrophotographic developer carrier and an electrophotographic developer can be obtained.

FERRITE PARTICLES, ELECTROPHOTOGRAPHIC DEVELOPER CARRIER CORE MATERIAL, ELECTROPHOTOGRAPHIC DEVELOPER CARRIER, AND ELECTROPHOTOGRAPHIC DEVELOPER
20230144641 · 2023-05-11 · ·

The present invention relates to a ferrite particle containing a crystal phase component containing a perovskite crystal represented by a compositional formula: RZrO.sub.3 (provided that R represents an alkaline earth metal element), having a surface roughness Rz of 2.0 μm or more and 4.5 μm or less, and satisfying the following formulas: 6.5≤log H.sub.1000≤8.5 and 0.80≤log H.sub.1000/log H.sub.100≤1.00. The ferrite particle can be used as an electrophotographic developer carrier core material. In addition, an electrophotographic developer carrier and an electrophotographic developer can be obtained.

CARRIER, DEVELOPER, IMAGE FORMING METHOD, AND PROCESS CARTRIDGE

A carrier is provided that includes a core particle and a coating layer coating the core particle. The coating layer includes a resin and chargeable inorganic fine particles, and has voids. The resin has an average film thickness of 0.10 μm or larger and smaller than 0.45 μm. The coating layer has a porosity of 0.1% or higher and lower than 2.8%, when the porosity expressed by the following equation:


Porosity [%]=S1/S2×100

where, on a cross section of the coating layer, S1 represents a cross sectional area of the voids and S2 represents a cross sectional area of the resin.

ELECTROSTATIC LATENT IMAGE DEVELOPING WHITE DEVELOPER, IMAGE FORMING METHOD, IMAGE FORMING APPARATUS, AND PROCESS CARTRIDGE

Provided is an electrostatic latent image developing white toner, including: a white toner including at least a binder resin, a white pigment, and a release agent; and a magnetic carrier including at least a core material, and a coating layer coating the core material and made of a coating resin and conductive particles, wherein Ra of the magnetic carrier is in a range of from 0.50 μm to 1.00 μm, and a bulk density of the magnetic carrier is in a range of from 2.08 g/cm.sup.3 to 2.24 g/cm.sup.3.

ELECTROSTATIC LATENT IMAGE DEVELOPING WHITE DEVELOPER, IMAGE FORMING METHOD, IMAGE FORMING APPARATUS, AND PROCESS CARTRIDGE

Provided is an electrostatic latent image developing white toner, including: a white toner including at least a binder resin, a white pigment, and a release agent; and a magnetic carrier including at least a core material, and a coating layer coating the core material and made of a coating resin and conductive particles, wherein Ra of the magnetic carrier is in a range of from 0.50 μm to 1.00 μm, and a bulk density of the magnetic carrier is in a range of from 2.08 g/cm.sup.3 to 2.24 g/cm.sup.3.

CARRIER FOR ELECTROSTATIC CHARGE IMAGE DEVELOPMENT AND TWO-COMPONENT DEVELOPER FOR ELECTROSTATIC CHARGE IMAGE DEVELOPMENT

Provided is a carrier for electrostatic charge image development which provides a two-component developer having a high electric charge amount, a suppressed variation in an electric charge amount caused by an environmental change, and excellent durability, even if a low temperature fixable toner is used.

A carrier for electrostatic charge image development of the present invention includes: carrier particles in which a core particle surface is coated with a coating material containing a resin, wherein the coating material contains phosphorus element, and the resin contains structural units derived from an alicyclic (meth)acrylic acid ester compound.

ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, AND TONER CARTRIDGE

An electrostatic charge image developing toner includes toner particles, silica particles having an average particle diameter of 80 nm to 200 nm, lubricant particles N which has negatively chargeable property, and lubricant particles P which has positively chargeable property, wherein a content (s) of the silica particles, a content (n) of the lubricant particles N, and a content (p) of the lubricant particles P satisfy relationships of Expression (1): 0.002≦p/s≦0.2; and Expression (2): 0.02≦n/s≦0.5.

ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, AND TONER CARTRIDGE

An electrostatic charge image developing toner includes: toner particles; first silica particles having an average circularity of 0.9 to 1.0, a particle size distribution index of 1.05 to 1.25, and a compression aggregation degree of 60% to 95%; and second silica particles having an average circularity of 0.9 to 1.0, a particle size distribution index of 1.05 to 1.25, and a compression aggregation degree of 60% to 95%, wherein, when an average primary particle diameter of the first silica particles is set as Da (nm) and an average primary particle diameter of the second silica particles is set as Db (nm), relationships of the following Expressions (A1) to (A3) are satisfied: Expression (A1): 80≦Da≦120, Expression (A2): 120≦Db≦200, and Expression (A3): 10≦Db−Da≦120.

TONER FOR DEVELOPING ELECTROSTATIC LATENT IMAGE

A toner for developing an electrostatic latent image includes: toner base particles containing a hybrid crystalline polyester resin having a crystalline polyester polymerized segment and an amorphous polymerized segment chemically bonded to each other and an amorphous resin; and an external additive including fatty acid metal salt particles, wherein a volume median diameter of the fatty acid metal salt particles is from 3.0 to 5.0 μm.

TONER FOR DEVELOPING ELECTROSTATIC LATENT IMAGE

A toner for developing an electrostatic latent image includes: toner base particles containing a hybrid crystalline polyester resin having a crystalline polyester polymerized segment and an amorphous polymerized segment chemically bonded to each other and an amorphous resin; and an external additive including fatty acid metal salt particles, wherein a volume median diameter of the fatty acid metal salt particles is from 3.0 to 5.0 μm.