G03G5/14795

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

Disclosed is a cylindrical electrophotographic photosensitive member having a region A along an outer surface and a region B along the outer surface. In this electrophotographic photosensitive member, the region A is located on an end side in an axial direction of the electrophotographic photosensitive member relative to the region B, the region A has a specific groove provided on the outer surface of the electrophotographic photosensitive member, an area ratio a1 of the groove is 65% to 100%, the region B has specific concave portions provided on the outer surface of the electrophotographic photosensitive member, and an area ratio a2 of the concave portion is 5% to 65%.

Electrophotographic photoreceptor

There is provided an electrophotographic photoreceptor obtained by sequentially laminating at least a photosensitive layer and an outermost layer on a conductive support, wherein the outermost layer contains a polymerized and cured product of a composition containing a polymerizable monomer and a filler, and the filler includes a conductive first filler surface-treated with a surface treatment agent having a silicone chain in a side chain, and a second filler having a relative dielectric constant which is lower than that of the first filler and 5 or less.

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC IMAGE FORMING APPARATUS

Provided is an electrophotographic photosensitive drum that achieves both of a reduction in torque of the electrophotographic photosensitive drum at the time of its cleaning and an improvement in image transferability. The electrophotographic photosensitive drum includes: a support; and a photosensitive layer arranged on the support, the electrophotographic photosensitive drum having arranged on an outer surface thereof at least two structure groups having different appearance periods, wherein when, out of the two structure groups, a group including structures having a smaller appearance period is defined as a first structure group, and a group including structures having a larger appearance period is defined as a second structure group, a height of the first structure group is lower than a height of the second structure group.

ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER

There is provided an electrophotographic photosensitive member having drum shape, the electrophotographic photosensitive member including a support and a photosensitive layer, wherein an outer surface of the electrophotographic photosensitive member has wrinkles, and when an observation region having square form with one side of 100 μm is placed at an arbitrary position on the outer surface, a line that passes through a central point of the observation region and is parallel to a circumferential direction of the electrophotographic photosensitive member is defined as a first reference line L1, and 3,599 reference lines obtained by rotating the first reference line L1 at every 0.1° around the central point are defined as L2 to L3,600, respectively, each of L1 to L3,600 intersects with convex portions of the wrinkles at a plurality of locations and has at least two different intersection angles selected from the plurality of locations.

METHOD FOR PRODUCING ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER

A method for producing an electrophotographic photosensitive member including: forming a photosensitive layer; and forming a protective layer, wherein the step of forming the photosensitive layer forms a photosensitive layer having an amount of residual solvent of a first solvent in the photosensitive layer of 0.05% to 2.50% and an amount of residual solvent of a second solvent in the photosensitive layer of 0.50% to 2.50%, and the step of forming the protective layer includes step (A) of forming a cured film and step (B) of forming the protective layer having wrinkle shapes, wherein, in step (A), the irradiated coating film is heated at a heating temperature lower than a boiling point of the first solvent and in step (B), the cured film is heated at a heating temperature higher than a boiling point of the first solvent.

IMAGE FORMING METHOD AND IMAGE FORMING SYSTEM
20210318632 · 2021-10-14 ·

Provided is an image forming method using a toner for developing an electrostatic charge image and an electrophotographic photoreceptor, and containing at least a charging step, an exposing step, a developing step and a transferring step, wherein the electrophotographic photoreceptor has a photosensitive layer, and the photosensitive layer contains a triphenylamine derivative having a specific structure as a charge transport material, and the toner for developing an electrostatic charge image contains at least titanic acid compound particles as an external additive.

Electrophotographic member, process cartridge, and electrophotographic apparatus

Provided is an electrophotographic member in which the increase in tackiness is small even in an environment of high temperature and high humidity. The electrophotographic member includes an electroconductive substrate and a surface layer, the surface layer contains resin including at least one of a urethane bond and an amide bond, the resin includes a cationic structure and an anionic structure in a molecule, and also includes a particular main-chain structure with hydrophobicity.

Image forming apparatus and image forming method

An image forming apparatus is provided that includes: an image bearer; a charger; an irradiator; a developing device containing a toner; and a transfer device. The image bearer has a Martens hardness of from 185 to 250 N/m.sup.2. The toner satisfies a relation 0.13≤X/Dn≤0.16, where X [μm] represents an average value of an amount of deformation of the toner by micro-indentation at when a load reaches 3.00×10.sup.−4 N at a loading rate of 3.0×10.sup.−5 N/sec under an environment of 32 degrees C. and 40% RH, and Dn [μm] represents a number average particle diameter of the toner. The toner contains an external additive comprising silica particles and particles composed mainly of strontium titanate. The particles composed mainly of strontium titanate further contain a third element M selected from the group consisting of La, Mg, Ca, Sn, and Si.

Dispersant-attached polytetrafluoroethylene particle, composition, layer-shaped article, electrophotographic photoreceptor, process cartridge, and image forming apparatus
11067911 · 2021-07-20 · ·

A dispersant-attached polytetrafluoroethylene particle includes a polytetrafluoroethylene particle; and a dispersant that contains a fluorine atom and is attached to a surface of the polytetrafluoroethylene particle. The dispersant-attached polytetrafluoroethylene particle has a particle size distribution index [D.sub.50-D.sub.10] of 50 nm or more.

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.