G03G9/09725

Electrophotographic apparatus and process cartridge

The electrophotographic apparatus and process cartridge comprising an electrophotographic photosensitive member, a cleaning blade, and developing unit containing a toner, wherein the cleaning blade comprising a support member and an elastic member whose portion is abutting a surface of the electrophotographic photosensitive member; the elastic member has an elastic modulus of 15 to 470 MPa with coefficient of variation for the elastic modulus being not more than 7.0%, and the absolute value of a difference between Martens hardness values is not more than 0.30 N/mm.sup.2 as measured under prescribed conditions; the toner contains a toner particle and an external additive whose a number-average primary particle diameter is from 5 to 25 nm, when X1 is a coverage ratio of the toner particle by the external additive and X2 is a theoretical coverage ratio, X1 is 50 to 85 area %, and X1/X2≥−0.0042×X1+0.60 is satisfied.

TONER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE, ELECTROSTATIC CHARGE IMAGE DEVELOPER, TONER CARTRIDGE, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

A toner for developing an electrostatic charge image includes toner particles having an average circularity Cc of 0.80 or more and less than 0.98, and an external additive containing monodisperse silica particles and titanate compound particles, in which a ratio Rt/Rs of an average primary particle diameter Rt of the titanate compound particles to an average primary particle diameter Rs of the monodisperse silica particles is 0.50 or more and 3.50 or less, and a ratio A/B of an external additive coverage A (%) of the monodisperse silica particles on surfaces of the toner particles to an external additive coverage B (%) of the titanate compound particles on the surfaces of the toner particles satisfies formula (1): 0<A/B≤2.00.

TONER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE AND ELECTROSTATIC CHARGE IMAGE DEVELOPER

A toner for developing an electrostatic charge image includes toner particles having an average circularity Cc of 0.80 or more and less than 0.98, and an external additive containing monodisperse silica particles and titanate compound particles, in which a ratio A/B of a coverage A (%) of the monodisperse silica particles on protruding portions of toner particle surfaces to a coverage B (%) of the monodisperse silica particles in recessed portions of the toner particle surfaces is 1.05 or more.

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

A toner for developing an electrostatic charge image contains toner particles having an average circularity Cc of 0.98 or more; and external additives including monodisperse silica particles having an average diameter of primary particles of 20 nm or more and 70 nm or less and titanate particles having an average diameter of primary particles of 20 nm or more and 70 nm or less, wherein the absolute difference between the average diameter of primary particles of the monodisperse silica particles and the average diameter of primary particles of the titanate particles is 25 nm or less.

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

An electrostatic charge image developing toner contains toner particles and silica particles that are added to an exterior of the toner particles and contain a nitrogen element-containing compound containing a molybdenum element, in which in the silica particles, a ratio (Mo/Si) of Net intensity of the molybdenum element to Net intensity of a silicon element measured by X-ray fluorescence analysis is 0.035 or more and 0.35 or less.

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

An electrostatic charge image developing toner contains toner particles, silica particles that are added to an exterior of the toner particles, and titanic acid compound particles that are added to the exterior of the toner particles and have an average circularity of 0.890 or more and 0.950 or less, in which the silica particles include particles having a primary particle size of 80 nm or less, the particles having a primary particle size of 80 nm or less have at least one peak in a range of 20 nm or more and less than 80 nm in a number-based primary particle size distribution curve (hereinafter, silica particles having such a peak will be called “specific silica particles”), the titanic acid compound particles have at least one peak in a range of 20 nm or more and less than 80 nm in a number-based primary particle size distribution curve, a difference between an average circularity of the specific silica particles and the average circularity of the titanic acid compound particles is 0.05 or less, and a difference between a toner coverage of the specific silica particles and a toner coverage of the titanic acid compound particles is 20% points or less.

METHOD OF PRODUCING RESIN PARTICLES AND METHOD OF PRODUCING ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER

A method of producing resin particles includes a first step of adding a monomer-containing emulsified liquid that contains a polymerizable monomer and an aqueous medium to an aqueous mother medium to polymerize the polymerizable monomer; and a second step of adding an aqueous medium for cooling to the aqueous mother medium after completion of the addition of the monomer-containing emulsified liquid to the aqueous mother medium.

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

An electrostatic charge image developing toner that has a binder resin that contains a crystalline resin and toner particles that contain resin particles, in which a loss coefficient tan δS (30) at 30° C. of the resin particles is 1 or more, and a loss coefficient tan δS (50) at 50° C. of the resin particles is less than 1.

TONER SET
20230091337 · 2023-03-23 · ·

A toner set and an image forming method, both of which can print a full-color image that is superior in gradation and color reproducibility of an image including a higher-order color and superior in continuous printing durability. When one color toner selected from the group consisting of the color toners included in the toner set is defined as a first toner and other color toners are defined as second toners, an internal friction angle θ1 (°) of the first toner and an internal friction angle θ2 (°) of each of the second toners satisfy relationships represented by the following formulae (1) and (2), and a first image developed with the first toner and second images developed with the second toners are transferred in this order on a recording medium or a transfer medium to form an image including a higher-order color:


θ1<θ2  Formula (1):


1°≤θ2−θ1≤3°.  Formula (2):

PHOTOLUMINESCENT TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPER, AND TONER CARTRIDGE

A photoluminescent toner includes a photoluminescent toner particle that contains a binder resin, a release agent, and a photoluminescent pigment and has a release agent domain, and a silicone oil-treated silica particle that is externally added to the photoluminescent toner particle, in which in observation of a cross section of the photoluminescent toner particle, an average major axis length Dw of the release agent domain and an average major axis length Dp of the photoluminescent pigment satisfy Expression (1).


0.3≤Dw/Dp≤1.0  Expression (1):