Canon Kabushiki Kaisha

Kabushiki Kaisha Toshiba

Other

Tatsuya Ikezue

Shuji Yoshizawa

Shoji Amamiya

Kimihiro Yoshimura

Kouichi Nakata

Daisuke Tanaka

Yosuke Morikawa

Kan Tanabe

Kumiko Takizawa

Takahiro Mitsui

Shuji Ishii

Tsuyoshi Shimada

Takanori Ueno

Ikuyo Kuroiwa

Haruhiko Mitsuda

Koichi Nakata

Akira Shimada

Akio Maruyama

Hiroki Uematsu

Kazushige Nakamura

Noboru Kashimura

Harumi Sakoh

Wataru Mitani

Akira Sanjoh

Mariko Yamamoto

Yuki Yamamoto

Hideki Ogawa

Takashige Kasuya

Atsushi Okuda

Yuka Ishiduka

Nobuhiro Nakamura

Atsushi Fujii

Kazunori Noguchi

Akihiro Maruyama

Haruyuki Tsuji

Yoshihisa Saito

Masaaki Yamagami

Mayumi Oshiro

Wataru Kitamura

Kazuko Sakuma

Kazuko Araki

An electrophotographic photosensitive member includes a support, an undercoat layer, a photosensitive layer, and a surface layer, the undercoat layer containing a binder resin and strontium titanate particles, the surface layer being a cured film of a composition containing at least one compound selected from a guanamine compound and a melamine compound, and a charge transport material having at least one substituent selected from &#x2014;OH, &#x2014;OCH, &#x2014;NH, &#x2014;SH, and &#x2014;COOH.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

Provided is an electrophotographic photosensitive member that can achieve both of abrasion resistance and the suppression of a ghost. The electrophotographic photosensitive member includes: a support; an undercoat layer; a charge-generating layer; and a charge-transporting layer, the undercoat layer, the charge-generating layer, and the charge-transporting layer being arranged in the stated order on the support, wherein the charge-transporting layer includes a charge-transporting substance, and a polymer containing a structure represented by the following general formula (1) and a structure represented by the following general formula (2), wherein the charge-generating layer includes a phthalocyanine crystal and a binder resin, and wherein the undercoat layer includes strontium titanate particles and a binder resin. 

An electrophotographic photoconductor includes, in sequence, a support member; an undercoating layer containing a binder resin and an inorganic particle; and a photosensitive layer, wherein the binder resin of the undercoating layer is an alkyd-melamine resin, and the inorganic particle of the undercoating layer contains a strontium titanate particle.

Electrophotographic photoconductor, process cartridge, and electrophotographic apparatus

The electrophotographic photosensitive member includes an undercoat layer and a surface layer on or above a support in this order, in which the undercoat layer contains metal oxide particles and a specific binder resin, the surface layer contains a charge transporting substance, fluororesin particles, and a specific binder resin, an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 &#x3bc;m or less, a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy a specific relationship, and a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy a specific relationship.

An electrophotographic photoreceptor abuts against a charging member and/or a developer carrying member with an abutting member therebetween, has a first portion and a second portion abutting against the abutting member along the longitudinal direction of the photoreceptor, and includes a support, a charge generating layer containing a charge generation material, and a surface layer in this order. The first portion includes an undercoat layer containing a polymer of a composition containing an electron transport material and a crosslinking agent and being contiguous with the surface of the charge generating layer facing the support. The second portion includes (i) an intermediate layer being disposed between and being contiguous with the support and the charge generating layer and/or (ii) an intermediate layer being disposed between and being contiguous with the charge generating layer and the surface layer, wherein the intermediate layers each have a Martens hardness of 500 N/mmor less.

Electrophotographic photoreceptor, process cartridge, and electrophotographic apparatus

An electrophotographic photosensitive member that abuts with a charging member and/or a developer carrying member with an abutting member interposed therebetween, wherein the electrophotographic photosensitive member has a first portion and a second portion abutting with the abutting member along the longitudinal direction thereof, the electrophotographic photosensitive member has a support, a charge generation layer containing a charge generating material and a polyacetal resin, and a surface layer in this order, the electrophotographic photosensitive member has, in the first portion, an undercoat layer containing a polymerized product of a composition including an electron transporting material and a cross-linking agent, the layer being adjacent to a surface of the charge generation layer, facing the support, and the electrophotographic photosensitive member has, in the second portion, an intermediate layer containing a metal oxide particle and a phenol resin, the layer being between and adjacent to the support and the charge generation layer.

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

An electrophotographic apparatus and a process cartridge include an electrophotographic photosensitive member; a developing unit; and a cleaning unit, wherein depressed portions separated from each other and satisfying conditions below are formed in the surface of the electrophotographic photosensitive member at a density of 10 or more per unit area of 1 cm: a depth of the depressed portions is defined as Rdv[&#x3bc;m], a minor-axis diameter of the depressed portions is defined as Lpc[&#x3bc;m], a major-axis diameter of the depressed portions is defined as Rpc[&#x3bc;m], and an angle formed between a direction of a major-axis of each of the depressed portions and a direction of movement of the surface of the electrophotographic photosensitive member is defined as &#x3b8;[&#xb0;].5[&#xb0;]&#x2266;&#x3b8;[&#xb0;]&#x2266;85[&#xb0;]0.3&#xd7;[&#x3bc;m]&#x2266;[&#x3bc;m]&#x2266;0.5&#xd7;[&#x3bc;m]1.1&#xd7;[&#x3bc;m]&#x2266;[&#x3bc;m]&#x2266;1.5&#xd7;[&#x3bc;m]50/Sin &#x3b8;[&#x3bc;m]&#x2266;[&#x3bc;m]&#x2266;1500[&#x3bc;m]

Electrophotographic apparatus and process cartridge

An electrophotographic photosensitive member is provide which inhibits recovered toner from leaking out of the edge portion at the time of long-term use, and has good durability. Each of at least both edge portions of the surface layer of the electrophotographic photosensitive member has a region in which independent depressed portions are formed at a density of ten or more portions per 100 &#x3bc;m square. An average depth Rdv-A, an average short axis diameter Lpc-A, and an average long axis diameter Rpc-A, of the depressed portions are respectively in specific ranges. When an angle formed between the circumferential direction of the electrophotographic photosensitive member and the long axis of each of the depressed portions is represented by &#x3b8;, the depressed portions are formed so that the angle &#x3b8; satisfies the relationship of 90&#xb0;&#x3c;&#x3b8;&#x3c;180&#xb0; toward the center of the electrophotographic photosensitive member.

An electrophotographic photosensitive member hard to cause the problem of chatter and wear-out of the cleaning blade and the problem of a rubbing memory, and both a process cartridge and an electrophotographic apparatus having the photosensitive member are provided. The peripheral surface of the photosensitive member has a plurality of dimple-shaped concaves, a 10-point average roughness Rzjis (A) as measured by sweeping along the circumference of the peripheral surface of the photosensitive member is 0.3 to 2.5 &#x3bc;m, a 10-point average roughness Rzjis (B) as measured by sweeping along the generating line of the peripheral surface of the photosensitive member is 0.3 to 2.5 &#x3bc;m, a mean spacing of profile irregularities, RSm (C), as measured by sweeping along the circumference of the peripheral surface of the photosensitive member is 5 to 120 &#x3bc;m, a mean spacing of profile irregularities, RSm (D), as measured by sweeping along the generating line of the photosensitive member is 5 to 120 &#x3bc;m, and the value of a ratio (D/C) of the mean spacing of profile irregularities RSm (D) to the mean spacing of profile irregularities RSm (C) is 0.5 to 1.5.

Electrophotographic Photosensitive member, method for manufacturing electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

An object of the present invention is to improve a phenomenon of the life-shortening of the endurance life due to scratch occurring when recesses of a fixed dimple shape are formed on the surface of the surface layer, in order to inhibit the chattering and folding back of a cleaning blade and the fracture of an edge, which occurs because friction between the surface layer of the surface of an electrophotographic photosensitive member and an abutting member is high; and particularly to improve the above described problems, from initial printing through printing on many sheets, which become particularly remarkable when using an electrophotographic photosensitive member with the use of a curable resin that is improved so as to have a high elastic deformation rate for the surface layer, in order to improve the strength of the surface layer, for the purpose of increasing the durability of an electrophotographic photosensitive member. An electrophotographic photosensitive member for achieving the object, which has a support and an organic photosensitive layer, is characterized in that the electrophotographic photosensitive member has dimple-shaped concavities formed on the surface of the surface layer of the electrophotographic photosensitive member, and further has the recesses with the same pattern as that on the surface of the surface layer, formed on the interface created between the surface layer of the organic photosensitive member and the layer directly under the surface layer (a subsurface layer).

Electrophotographic photosensitive member, method for manufacturing electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

An electrophotographic photosensitive member is disclosed having a cylindrical support and an organic photosensitive layer provided on the cylindrical support. The peripheral surface of the electrophotographic photosensitive member is composed of grooves formed substantially in its peripheral direction and flat portions, and in the grooves, the number of grooves each having a width in the range of from 0.5 &#x3bc;m to 40 &#x3bc;m is from 20 to 1,000 lines per 1,000 &#x3bc;m in width in the generatrix direction of the peripheral surface of the electrophotographic photosensitive member.

Electrophotographic photosensitive member, electrophotographic photosensitive member manufacturing process, process cartridge, and electrophotographic apparatus

According to the present invention, there is provided: an electrophotographic photosensitive member having a photosensitive layer on a support in which a surface layer of the electrophotographic photosensitive member comprises an acrylic polymer having a polyfluoroolefin unit and an alkylene oxide unit, and having a number-average molecular weight in a range of 2,000 to 20,000; a process cartridge and an electrophotographic apparatus both comprising the electrophotographic photosensitive member.

Electrophotographic photosensitive member, electrophotographic apparatus, and process cartridge

An electrophotographic photosensitive member having a surface layer containing at least one of a charge-transporting material and conductive particles and a polymer obtained by polymerizing at least one selected from the group consisting of a polyhydroxymethylbisphenol monomer having a specific structure, a polyhydroxymethylbisphenol oligomer having a specific structure, a polyhydroxymethyltrisphenol monomer having a specific structure and a polyhydroxymethyltrisphenol oligomer having a specific structure; and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.

The present invention relates to an electrophotographic photosensitive member comprising a surface layer excellent in adhesiveness and abrasion resistance, having a hardness and a toughness, and not degrading the charge transport property. One aspect of the present invention provides an electrophotographic photosensitive member comprising a photosensitive layer on a conductive support, wherein a surface layer of the photosensitive member contains a crosslinked epoxy-modified resol type phenolic resin, and at least one of a charge transport material and a conductive fine particle.

A phenolic compound having a plurality of substituted hydroxyphenyl groups and charge-transportable structure, the substituted hydroxyphenyl groups of which have a hydroxymethyl group; and a resol resin obtained by allowing a phenolic compound having hydroxyphenyl groups and charge-transportable structure, to react with formaldehyde in the presence of a basic catalyst, and having charge-transportable structure. Also disclosed are a cured product and an electrophotographic photosensitive member which make use of the above, and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.

PHENOLIC COMPOUND, NOVEL RESOL RESIN, CURED PRODUCTS THEREOF, ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER CONTAINING THEM, AND PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS WHICH HAVE THE ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER

Growing community of inventors

Toride, Japan

Tatsuya Ikezue