G03G9/1133

ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER, DEVELOPER, AND IMAGE FORMING METHOD
20180011413 · 2018-01-11 · ·

An object of the present invention is to provide an electrostatic charge image developing toner, a two-component developer, and an image forming method, each capable of employing a two-component trickle touchdown developing system which ensures excellent image density stability and no occurrence of ghost and is used in an electrophotographic copier or an electrostatic recording device. The present invention provides an electrostatic charge image developing toner having positive chargeability; containing a styrene acrylic resin as the binding resin; and containing a nigrosine-containing positive charge control agent and a negative charge control agent as the charge control agent, in which the percentage content of the percentage content of the negative charge control agent in all charge control agents is not less than the percentage content of the positive charge control agent.

CARRIER FOR DEVELOPING ELECTROSTATIC IMAGE, ELECTROSTATIC IMAGE DEVELOPER, AND IMAGE FORMING METHOD

A carrier for developing an electrostatic image includes a magnetic particle and a resin layer with which the magnetic particle is coated and which contains silica particles having an average particle diameter of 50 nm or more and 200 nm or less. In the carrier, a silicon element ratio Si1 in a region in which a distance from a surface of the resin layer in a direction toward an inside is 0.1 μm or more and 0.2 μm or less and a silicon element ratio Si2 in a region in which a distance from a surface of the magnetic particle in a direction toward the surface of the resin layer is 0.0 μm or more and 0.1 μm or less satisfy formula 1-1 and formula 2-1 below.


0.005≤Si1≤2  Formula 1-1


1≤Si1/Si2≤1000  Formula 2-1

TWO-COMPONENT DEVELOPER FOR ELECTROSTATIC CHARGE IMAGE DEVELOPMENT, ELECTROPHOTOGRAPHIC IMAGE FORMING METHOD AND ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS
20220390873 · 2022-12-08 ·

Provided is a two-component developer for electrostatic charge image development including: toner particles containing toner base particles and an external additive disposed on a surface of the toner base particles; and carrier particles having a core material particle and a shell portion disposed on a surface of the core material particle, wherein the external additive contains inorganic particles surface-modified with a surface modifier represented by the following Formula (1); and a value of an iron element content (atomic %) measured by X-ray photoelectron spectroscopy (XPS) on a surface of the carrier particles satisfies the following Expression (1),


(R.sub.1).sub.4-n—Si—(X).sub.n  Formula (1):


4.0≤{A.sub.Fe/(A.sub.c+A.sub.o+A.sub.Fe)}×100≤15.0  Expression (1):

Carrier for forming electrophotographic image, developer for forming electrophotographic image, electrophotographic image forming method, electrophotographic image forming apparatus, and process cartridge

A carrier for forming an electrophotographic image is provided. The carrier comprises a core particle and a resin layer coating the core particle. The resin layer contains a chargeable particle A, a conductive particle B, a dispersing agent, and a defoaming agent.

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

An electrostatic charge image developer contains: a toner containing a toner particle and an external additive; and a carrier containing a magnetic particle and a resin layer covering the magnetic particle; and the toner particle has a surface property index value of 1.0 or more and less than 2.0; and the carrier has a surface having a ratio B/A of a surface area B to a plane view area A of 1.020 or more and 1.100 or less, the plane view area A and the surface area B being obtained by three-dimensional analysis of the surface of the carrier.

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

An electrostatic charge image developer containing: a toner containing a toner particle and an external additive; and a carrier containing a magnetic particle and a resin layer covering the magnetic particle, in which the toner particle has a surface property index value of 2.0 or more and 2.8 or less; and the carrier has a surface having a ratio BIA of a surface area B to a planar view area A of 1.020 or more and 1.100 or less, the planar view area A and the surface area B being obtained by three-dimensional analysis of the surface of the carrier.

ELECTROSTATIC IMAGE DEVELOPING CARRIER, ELECTROSTATIC IMAGE DEVELOPER, PROCESS CARTRIDGE, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD

An electrostatic image developing carrier includes core particles provided by dispersing a magnetic powder in a resin and resin cover layers covering the core particles, wherein the resin cover layers have a surface coverage of 96 area % or more, the resin cover layers include 10 mass % or more and 50 mass % or less of inorganic particles relative to a total mass of the resin cover layers, and the inorganic particles in surfaces of the carrier have a surface exposure ratio of 6 atomic % or more and 15 atomic % or less determined by X-ray photoelectron spectroscopy.

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 (σ/RSm) to this RSm of the standard deviation σ of the width of the region where one period of a protrusion and a recess occurs, are in prescribed ranges.
R—Si(O.sub.1/2).sub.3  (T3) R in the formula represents a prescribed substituent.

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.