G03G9/1134

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.

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.

CARRIER FOR TWO-COMPONENT DEVELOPER, TWO-COMPONENT DEVELOPER, AND METHOD OF PREPARING CARRIER FOR TWO-COMPONENT DEVELOPER

A carrier for two-component developer includes a magnetic particle and a resin coating layer that covers the magnetic particle and contains a resin, wherein a weight average molecular weight of the resin contained in the resin coating layer is from 1,800,000 to 5,000,000.

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

An electrostatic charge image developing carrier includes a magnetic particle and a coating resin layer that covers the magnetic particle and contains an inorganic particle, and the following relation 1 is satisfied: 0<(C−A)/(B−A)≤0.40 (relation 1), in which A is a Net intensity of Si determined by an X-ray fluorescence analysis of a carrier A that is a carrier taken out from a developer A obtained by mixing a carrier and a toner with a silica particle externally added, B is a Net intensity of Si determined by the X-ray fluorescence analysis of a carrier B that is a carrier taken out from a developer B obtained by adding a silica particle to the developer A to obtain a mixture and stirring the mixture with a Turbula stirring apparatus for 20 minutes, and C is a Net intensity of Si determined by the X-ray fluorescence analysis of a carrier C that is a carrier taken out from a mixture C obtained by stirring a toner particle and the carrier B being the carrier taken out from the developer B for 2 minutes with the Turbula stirring apparatus.

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

An electrostatic charge image developing carrier includes a magnetic particle and a coating resin layer that covers the magnetic particle, and an amount of the coating resin layer that is peeled off from the magnetic particle when the carrier dispersed in water is irradiated with ultrasonic waves, relative to a coating amount of the coating resin layer before ultrasonic irradiation, is 800 mass ppm or more and 2,000 mass ppm or less, and a difference between an initial coating amount of the coating resin layer of a carrier having no travel history and a coating amount of the coating resin layer of a carrier having a travel history and being taken out from an electrostatic charge image developer, relative to the initial coating amount of the coating resin layer, is 0 mass ppm or more and 3,000 mass ppm 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 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.

DEVELOPER, IMAGE FORMING APPARATUS, AND IMAGE FORMING METHOD
20170261875 · 2017-09-14 · ·

A developer includes a toner including toner particles and a carrier including carrier particles. The carrier particles each include a carrier core and a carrier coating layer covering the carrier core. The carrier coating layer contains a fluorine-containing resin. The toner particles each include a toner mother particle and resin particles located on a surface of the toner mother particle. The resin particles have a number average primary particle diameter of at least 70 nm and no greater than 200 nm. A dispersion obtained by dispersing 0.1 g of the resin particles in 100 mL of distilled water has an electrical conductivity of at least 2.5 μS/m and no greater than 6.0 μS/m. A degree of aggregation Y.sub.160 of the resin particles represented by expression (1) “Y.sub.160=100×M.sub.160A/M.sub.160B” is at least 15% by mass and no greater than 40% by mass.

MAGNETIC CARRIER, TWO-COMPONENT DEVELOPER, AND DEVELOPER FOR REPLENISHMENT

A magnetic carrier, which is suppressed from causing the loss and wear of a magnetic carrier coating resin even when used for a long time period, and achieves a stable image density and a reduction in toner scattering. In the magnetic carrier, the resin coating layer contains a resin A having a fluorine polymer moiety, the resin coating layer has an average thickness of 50 nm or more, a ratio F(x) (atomic %) of a fluorine atom detected at a position at a depth of x nm from a surface of a magnetic carrier particle by X-ray photoelectron spectroscopy satisfies formula (1) and formula (2), and when x represents an integer of 0 or more and 20 or less, F(x) satisfies formula (3):


5.0≤F(0)≤15  (1)


F(20)≤5.0  (2)


|F(x+1)−F(x)|≤7.5  (3).

CARRIER, XEROGRAPHIC DEVELOPER, AND CARRIER PRODUCTION METHOD

The present invention relates to a carrier including: a magnetic core material; and a resin coating layer coating a surface of the magnetic core material, in which the resin coating layer contains a binder resin, and fluorine element-containing resin particles dispersed in the binder resin, the resin coating layer has a coefficient of variation of a film thickness of 25% or less, and the resin coating layer has an average value of the number of the fluorine element-containing resin particles being 3 particles/μm.sup.2 or more and 350 particles/μm.sup.2 or less per unit area in a cross section of the resin coating layer, and has a coefficient of variation thereof being 20% or less.

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

A method for producing a carrier for developing an electrostatic charge image, the method includes: adding a coating liquid containing a resin, conductive particles, and a solvent and magnetic particles to a mixer having a stirring blade, and mixing the coating liquid and the magnetic particles to obtain a mixture; and evaporating and drying the solvent from the mixture to produce a carrier having a resin coating layer on surfaces of the magnetic particles, wherein a viscosity μ of the coating liquid when being added to the mixer is more than 60 mPa.Math.s and 1,000 mPa.Math.s or less, and a value of a ratio μ/W of the viscosity μ(mPa.Math.s) to an amount W (parts by mass) of the resin coating layer with respect to 100 parts by mass of the magnetic particles in the carrier is 20 or more and 500 or less.