G03G9/1075

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.

MAGNETIC CARRIER AND TWO-COMPONENT DEVELOPER

A magnetic carrier comprises a magnetic carrier core and a coating resin layer coating a surface of the magnetic carrier core. The coating resin layer contains resin A and resin B at contents of 1% to 50% by mass and 50% to 90% by mass, respectively, based on resin components of the coating resin layer. The resin A has a first partial structure and a second partial structure, while the resin B has a third partial structure and a fourth partial structure. The mass X of the resin A, the total mass Ma of the first partial structure, and the total mass Mb of the second partial structure satisfy 0.50≤(Ma+Mb)/X≤1.00 and 0.10≤a/b≤30.0, and the SP value of the first partial structure SPa1 and the SP value of the third partial structure SPb3 satisfy 0≤|SPa1—SPb3|≤10.0.

CARRIER FOR DEVELOPING ELECTROSTATIC LATENT IMAGE, TWO-COMPONENT DEVELOPER, IMAGE FORMING APPARATUS, PROCESS CARTRIDGE, AND IMAGE FORMING METHOD

A carrier for developing an electrostatic latent image is provided. The carrier comprises a core particle having an internal void ratio of from 0.0% to 2.0% and a coating layer coating the core particle. The coating layer contains flat chargeable particles satisfying Formula 1 blow:


1.0≤R1/R2≤3.0  Formula 1

where R1 [nm] and R2 [nm] represent a major axis and a thickness, respectively, of each of the flat chargeable particles. The carrier has an apparent density of from 2.0 to 2.5 g/cm.sup.3.

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.

Ferrite carrier core material for electrophotographic developer, carrier for electrophotographic developer, and developer

Provided are a ferrite carrier core material for an electrophotographic developer having a full length L.sub.1 of grain boundary and a circumference length L.sub.2 of the core material in a cross-section of the core material, and satisfying a relationship of 2≤L.sub.1/L.sub.2≤9; a carrier for an electrophotographic developer including the ferrite carrier core material and a coating layer containing a resin provided on a surface of the ferrite carrier core material; and an electrophotographic developer including the carrier and a toner.

Magnetic core material for electrophotographic developer, carrier for electrophotographic developer, developer, method for producing magnetic core material for electrophotographic developer, method for producing carrier for electrophotographic developer, and method for producing developer
11099495 · 2021-08-24 · ·

To provide a magnetic core material and carrier for electrophotographic developer, which have small environmental dependence of the electric resistance, can suppress the carrier scattering, and can stably provide good images; a developer contains the carrier; and methods for producing them. The magnetic core material satisfying a value of Formula (1): a+b×10+c+d+e+f, being from 20 to 150, when a fluoride ion amount is denoted by a (ppm), a chloride ion amount is denoted by b (ppm), a bromide ion amount is denoted by c (ppm), a nitrite ion amount is denoted by d (ppm), a nitrate ion amount is denoted by e (ppm), and a sulfate ion amount is denoted by f (ppm), which are measured by a combustion ion chromatography method.

Electrostatic charge image developer, process cartridge, image forming apparatus, and image forming method

An electrostatic charge image developer contains toner particles, layered-compound particles that are particles of a nitrogen-containing layered compound, and a resin-coated carrier that has magnetic particles and a resin layer covering the magnetic particles. The maximum height Ry of the roughness profile as defined in JIS B0601: 1994 of the surface of the resin-coated carrier is 0.01 μm or more and 0.20 μm or less.

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

An electrostatic charge image developer contains toner particles, layered-compound particles that are particles of a nitrogen-containing layered compound, and a resin-coated carrier that has magnetic particles and a resin layer covering the magnetic particles. The maximum height Ry of the roughness profile as defined in JIS B0601: 1994 of the surface of the resin-coated carrier is 0.01 μm or more and 0.20 μm or less.

TONER, TONER CARTRIDGE, AND IMAGE FORMING APPARATUS
20210286278 · 2021-09-16 · ·

According to one embodiment, a toner having excellent heat roller life performance, low-temperature offset resistance, and high-temperature offset resistance, and a toner cartridge and an image forming apparatus, in each of which the toner is stored, are provided.

A toner according to an embodiment contains a colorant, an amorphous polyester resin A, and an amorphous polyester resin B. The amorphous polyester resin A has an Mw.sub.A of 0.9×10.sup.4 to 1.5×10.sup.4. The amorphous polyester resin B has an Mw.sub.B of 4.0×10.sup.4 to 11.0×10.sup.4. The amorphous polyester resin A has an Mn.sub.A of 3.0×10.sup.3 to 4.0×10.sup.3. Mw.sub.A/Mn.sub.A is between 3.1 and 4.0. The amorphous polyester resin B has an Mn.sub.B of 2.2×10.sup.3 to 3.5×10.sup.3. Mw.sub.B/Mn.sub.B is between 11.4 and 50. The content of the amorphous polyester resin A is between 50 and 60 mass %. The content of the amorphous polyester resin B is between 20 and 30 mass %.