G03G5/0592

IMAGE CARRIER UNIT AND IMAGE FORMING APPARATUS
20210063941 · 2021-03-04 ·

An image carrier unit includes an image carrier that makes a rotation and has a photosensitive layer on an outer surface, the photosensitive layer containing a binding resin and at least one type of charge transporting material and covering the surface, and a cleaning blade that has a contact part contacting the surface of the image carrier and removes residue on the surface of the image carrier accompanying the rotation of the image carrier. A photosensitive ratio of a first product to a second product is 183.0 or higher and 233.9 or lower, the first product is obtained from a weight-average molecular weight (A) of the binder resin multiplied by an added ratio (B) of the binder resin in the photosensitive layer, and the second product is obtained from a weight-average molecular weight (C) of the charge transporting material multiplied by an added ratio (D) of the charge transporting material.

Electrophotographic image forming apparatus and electrophotographic image forming method

An electrophotographic image forming apparatus includes: an electrophotographic photoreceptor; a charger that charges a surface of the electrophotographic photoreceptor; an exposer that exposes the charged electrophotographic photoreceptor; a developer that supplies a toner to the electrophotographic photoreceptor on which an electrostatic latent image is formed; a transferer that transfers a toner image formed on the electrophotographic photoreceptor; and a cleaner that removes a residual toner remaining on a surface of the electrophotographic photoreceptor, wherein the electrophotographic photoreceptor includes an outermost layer, a surface of the outermost layer has a projection structure due to a ridge of the inorganic filler, the toner contains toner base particles and metal oxide particles as an external additive externally added to the toner base particles, 70% or more of the toner base particles are covered with the metal oxide particles as the external additive, and following formulas (1) to (3) are satisfied. [ Numerical formula 1 ] R 2 2 2 R 1 R 3 - R 1 2 ( 1 ) 0 < R 1 < R 3 <

ELECTROPHOTOGRAPHIC PHOTORECEPTOR, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer disposed on the conductive substrate. An outermost surface layer of the electrophotographic photoreceptor contains a fluorine-based graft polymer and a fluorine-containing resin particle. The fluorine-based graft polymer includes at least a first structural unit that does not have an acidic group with a pKa of 3 or less but has a fluorine atom, a second structural unit derived from a macromonomer, and a third structural unit having the acidic group with a pKa of 3 or less.

ELECTROPHOTOGRAPHIC PHOTORECEPTOR, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer disposed on the conductive substrate. An outermost surface layer of the electrophotographic photoreceptor contains a fluorine-containing resin particle and a fluorine-based graft polymer having a fluorinated alkyl group. A ratio of an amount of a fluorine-based graft polymer separated from the fluorine-containing resin particle to a total amount of the fluorine-based graft polymer in the outermost surface layer is 15% or less.

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS
20210033992 · 2021-02-04 ·

Provided is an electrophotographic photosensitive member including: a support, a photosensitive layer provided on the support, and a surface layer provided on the photosensitive layer, wherein the surface layer of the electrophotographic photosensitive member contains a cured product of a composition containing a charge transporting substance having a polymerizable functional group, a compound having a specific structure, a fluororesin particle, and polyvinyl acetal.

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS
20210033991 · 2021-02-04 ·

Provided is an electrophotographic photosensitive member improved both in wear resistance and in image unevenness. The electrophotographic photosensitive member includes a support, and a photosensitive layer and a surface layer on the support, wherein the surface layer is a cured product of a composition containing a compound represented by the formula (A) and a charge-transporting substance having at least one reactive functional group selected from the group consisting of a hydroxy group, a methoxy group, an amino group, a thiol group, and a carboxyl group.

Image forming apparatus and image forming method

In an image forming apparatus, a cleaning member is pressed against a circumferential surface of an image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. The toner has a number average roundness of 0.965 to 0.998. The toner has a D.sub.50 of 4.0 m to 7.0 m. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is 10 N/m to 40 N/m. The image bearing member includes a single-layer photosensitive layer containing a charge generating material and a hole transport material. Ionization potential Ip.sub.HTM of the hole transport material and ionization potential Ip.sub.CGM of the charge generating material satisfy mathematical formula (1) Ip.sub.HTM5.30 eV, mathematical formula (2) Ip.sub.CGM5.30 eV, and mathematical formula (3) 0.09 eV|Ip.sub.HTMIp.sub.CGM|0.30 eV.

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS
20200393772 · 2020-12-17 ·

The present disclosure provides an electrophotographic photosensitive member having a surface layer in which an occurrence of the image deletion is suppressed; a process cartridge equipped with the electrophotographic photosensitive member; and an electrophotographic apparatus provided with the process cartridge. An electrophotographic photosensitive member has a surface layer that includes a copolymerized product of a composition including a metal oxide particle having a polymerizable functional group on a surface thereof and a polymerizable compound having a particular structure.

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS
20200393775 · 2020-12-17 ·

An electrophotographic photosensitive member including: a support; and a surface layer, wherein the surface layer contains a cured product of a composition containing a curable hole-transport compound, a specific fluorine-atom-containing compound, and a specific polymerizable compound.

Image forming method, image forming apparatus, and process cartridge

An image forming method includes forming an image with a toner using a photoconductor in which an intermediate layer and a photosensitive layer including a charge generating layer and a charge transport layer are formed overlying an electroconductive substrate, wherein the ionization potential of the surface of the photoconductor and the ionization potential of the surface of the toner satisfy the following relations 1 and 2,
|Ip (the surface of the photoconductor)Ip (the surface of the toner)|5.53 (eV) Relation 1
5.45 (eV)Ip (the surface of the photoconductor)5.53 (eV) Relation 2
where Ip (the surface of the photoconductor) represents the ionization potential of the surface of the photoconductor and Ip (the surface of the toner) represents the ionization potential of the surface of the toner.