G03G9/0839

Carrier for electrostatic image development, electrostatic image developer, and process cartridge

A carrier for electrostatic image development includes: a core material; and a coating resin layer that contains inorganic particles and covers the core material. The content of the inorganic particles is 10% by mass or more and 60% by mass or less based on the total mass of the coating resin layer. The volume average diameter D (μm) of the inorganic particles and the thickness T (μm) of the coating resin layer satisfy the following relational expression (1): 0.007≤D/T≤0.24.

Electrostatic charge image developing carrier, electrostatic charge image developer, and image forming apparatus

An electrostatic charge image developing carrier includes: magnetic particles; and a resin layer coating the magnetic particles and containing inorganic particles, in which an average particle diameter of the inorganic particles is 5 nm or more and 90 nm or less, an average thickness of the resin layer is 0.6 μm or more and 1.4 μm or less, and a ratio B/A of a surface area B of the electrostatic charge image developing carrier to a plan view area A of the electrostatic charge image developing carrier is 1.020 or more and 1.100 or less when a surface of the electrostatic charge image developing carrier is three-dimensionally analyzed.

TONER
20230140479 · 2023-05-04 · ·

A toner includes toner particles. The toner particles each include a toner mother particle and an external additive provided on the surface of the toner mother particle. The toner mother particles contain a binder resin and a magnetic powder. The external additive includes alumina particles. The alumina particles have a number average primary particle diameter of at least 150 nm and no greater than 400 nm. The toner has a time constant of at least 1.0 seconds and no greater than 10.0 seconds. A sediment has a zeta potential at pH 2 of at least 0.0 mV and no greater than 20.0 mV. The sediment is obtained by separation from a dispersion of the toner.

Carrier for developing electrostatic charge image, electrostatic charge image developer, and image forming apparatus

A carrier for developing an electrostatic charge image has magnetic particles and a resin coating that covers the magnetic particles and contains at least one lubricant. The resin coating has a dispersed phase of the lubricant and meets requirement (1). Requirement (1): the lubricant content in a top layer>the lubricant content in a middle layer>the lubricant content in a bottom layer The top, middle, and bottom layers are of the resin coating divided into three in the direction of thickness, and the lubricant content is the percentage area of the dispersed phase of the lubricant in a cross-section of the layer taken along the thickness thereof.

Toner

A toner including a toner particle that contains a binder resin, and an inorganic fine particle, wherein the inorganic fine particle contains aggregated particles; the aggregated particles contain primary particles of at least one metal salt selected from the group consisting of titanate metal salts and zirconate metal salts; the primary particles have a number-average particle diameter of from 15 nm to 55 nm; the aggregated particles have an aggregation diameter of from 80 nm to 300 nm, the aggregated particles have a volume resistivity of from 2×10.sup.9 Ω.Math.cm to 2×10.sup.13 Ω.Math.cm; and the aggregated particles cover a surface of the toner particle, and a coverage ratio of the aggregated particles with respect to the surface of the toner particle is from 0.3 area % to 10.0 area %.

CARRIER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE, ELECTROSTATIC CHARGE IMAGE DEVELOPER, AND IMAGE FORMING APPARATUS

A carrier for developing an electrostatic charge image has magnetic particles and a resin coating that covers the magnetic particles and contains at least one lubricant. The resin coating has a dispersed phase of the lubricant and meets requirement (1).

Requirement (1): the lubricant content in a top layer>the lubricant content in a middle layer>the lubricant content in a bottom layer

The top, middle, and bottom layers are of the resin coating divided into three in the direction of thickness, and the lubricant content is the percentage area of the dispersed phase of the lubricant in a cross-section of the layer taken along the thickness thereof.

ELECTROSTATIC CHARGE IMAGE DEVELOPING CARRIER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, AND IMAGE FORMING APPARATUS

An electrostatic charge image developing carrier includes: magnetic particles; and a resin layer coating the magnetic particles and containing inorganic particles, in which an average particle diameter of the inorganic particles is 5 nm or more and 90 nm or less, an average thickness of the resin layer is 0.6 μm or more and 1.4 μm or less, and a ratio B/A of a surface area B of the electrostatic charge image developing carrier to a plan view area A of the electrostatic charge image developing carrier is 1.020 or more and 1.100 or less when a surface of the electrostatic charge image developing carrier is three-dimensionally analyzed.

MAGNETIC CARRIER, TWO-COMPONENT DEVELOPER, AND METHOD FOR PRODUCING MAGNETIC CARRIER

A magnetic carrier including a magnetic carrier particle having a magnetic core particle and a coating layer of an organosilicon polymer on a surface of the magnetic core particle, wherein the organosilicon polymer has the structure given by formula (T3) below; in .sup.29Si-NMR measurement of the THF-insoluble matter of the organosilicon polymer, the ratio ST3 of the peak area for the structure given by formula (T3) to the total peak area for the organosilicon polymer is at least 0.05; and in the roughness curve measured on the magnetic carrier particle, the mean width (RSm) of the roughness curve elements of the magnetic carrier particle, and the ratio (/RSm) to this RSm of the standard deviation of the width of the region where one period of a protrusion and a recess occurs, are in prescribed ranges.


RSi(O.sub.1/2).sub.3(T3)

R in the formula represents a prescribed substituent.

CARRIER FOR ELECTROSTATIC IMAGE DEVELOPMENT, ELECTROSTATIC IMAGE DEVELOPER, AND PROCESS CARTRIDGE

A carrier for electrostatic image development includes: a core material; and a coating resin layer that contains inorganic particles and covers the core material. The content of the inorganic particles is 10% by mass or more and 60% by mass or less based on the total mass of the coating resin layer. The volume average diameter D (m) of the inorganic particles and the thickness T (m) of the coating resin layer satisfy the following relational expression (1): 0.007D/T0.24.

TONER

A magnetic toner comprising a toner particle, the toner particle comprising a magnetic body, a crystalline resin A, and an amorphous resin B. The crystalline resin A has a monomer unit (a). The amorphous resin B has a monomer unit (b). A content of the crystalline resin A in the toner is 6.2 to 77.0 mass %. The sum of contents of the crystalline resin A and the amorphous resin B in the toner is 30.0 mass % or more. A content of the monomer unit (a) in the crystalline resin A is 50.0 to 100.0 mass %. Using SPA [(J/cm.sup.3).sup.0.5] for a SP value of the crystalline resin A and using SPB [(J/cm.sup.3).sup.0.5] for a SP value of the amorphous resin B, SPA and SPB satisfy 0.15SPBSPA2.00.