Canon Kabushiki Kaisha

Kunihiko Sekido

Michiyo Sekiya

Masashi Nishi

Hideaki Nagasaka

Atsushi Okuda

Kei Tagami

Shinji Takagi

Yuka Ishiduka

Nobuhiro Nakamura

Yota Ito

Hiroyuki Tomono

Akihiro Maruyama

Yosuke Morikawa

Nobumichi Miki

Takeshi Murakami

Taichi Sato

Kenichi Kaku

Akihito Saitoh

Atsushi Fujii

Takashi Anezaki

Akihiro Senoo

Takashi Kenmoku

Harunobu Ogaki

Kazumichi Sugiyama

Kozue Uratani

Yuki Yamamoto

Daisuke Tanaka

Kazunori Noguchi

Yoshio Kashizaki

Tatsuya Saeki

Koki Inoue

Shuntaro Watanabe

Hajime Miyazaki

Hiroyuki Watanabe

Shintetsu Go

Kohei Makisumi

Isao Kawata

Yuto Ito

Hiroyuki Ohmori

Shinji Tagaki

Masatada Hirota

An electrophotographic photosensitive member includes a support, a photosensitive layer, and a surface layer. The surface layer includes a cured product of a composition containing an organic salt having a polymerizable functional group, and at least one of a charge-transportable compound or electroconductive particles. The organic salt is formed of an organic cation and at least one of BF, PF, (CFSO)N, CFSO, (FSO)N, CHOSO, (CN)N, SCN, CHCOO, NO, Cl, Bror I.

Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

An electrophotographic photosensitive member includes an electroconductive support, a photosensitive layer, and a protection layer The protection layer comprises an electroconductive particle with has a surface containing a titanium oxide and a niobium atom. An atomic concentration ratio of the niobium atom to the titanium atom in the titanium oxide is 0.01 to 0.20, and the electroconductive particle is surface-treated with a compound having a silicon atom. A content ratio of the electroconductive particle in the protection layer is 5 vol % or more and less than 40 vol % with respect to a total volume of the protection layer, and relative concentrations of a plurality of atoms at a surface of the protection layer satisfy specific conditions, as determined by X-ray photoelectron spectroscopy.

A process cartridge that is detachable from a main body of an electrophotographic apparatus, in which a surface protective layer of an electrophotographic photosensitive member contains an electroconductive particle; the content of the electroconductive particle is 20.0 to 70.0% by volume of the surface protective layer; the surface protective layer has a volume resistivity of 1.0×10to 1.0×10Ω·cm; a toner particle has at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron; and a total content of the multivalent metal elements in the toner particle, as measured by coupled induction plasma atomic emission spectrometry (ICP-AES), is 0.10 to 1.25 μmol/g.

Process cartridge

Provided is an electrophotographic photosensitive member having a satisfactory chargeability and being excellent in fogging suppression. The electrophotographic photosensitive member is an electrophotographic photosensitive member including a surface protective layer, wherein the surface protective layer is a polymerized film of a composition containing a compound having one of an acryloyloxy group or a methacryloyloxy group, a conductive particle, and an organic salt formed of at least one organic cation selected from the group consisting of: imidazolium; pyridinium; pyrrolidinium; piperidinium; a tetraalkylammonium; and a tetraalkylphosphonium, and at least one anion selected from the group consisting of organic or inorganic anions, and wherein the content of the organic salt is 0.1 mass % to 10.0 mass % with respect to the total mass of the conductive particle.

An electrophotographic photosensitive member capable of maintaining a charging ability during repeated use is provided. An electrophotographic photosensitive member having a support, a conductive layer, a photosensitive layer and a protective layer in this order, wherein the protective layer contains a binding resin and a metal oxide particle, the metal oxide particle has a core and a coating layer, the core and the coating layer each contain titanium oxide, and the coating layer further includes niobium.

Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

Provided is an electrophotographic photosensitive member including an electroconductive support, a photosensitive layer, and a protection layer, wherein the protection layer contains electroconductive particles, a content of the electroconductive particles in the protection layer is 40 to 70 vol %, and a volume resistivity of the protection layer is 1.0×10to 1.0×10Ω·cm.

Provided are a process cartridge and an electrophotographic apparatus each capable of suppressing an image defect (coarseness in a halftone image) caused by toner scattering in association with a charging failure that occurs when the process speed of the electrophotographic apparatus is further increased. The process cartridge includes: an electrophotographic photosensitive member; and a developing unit, which includes a toner storing portion that stores a toner, and which supplies the toner to a surface of the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a surface protective layer containing an electroconductive particle in an appropriate amount, and the volume resistivity of the surface protective layer is controlled. As the toner, there is used a toner in which an organosilicon polymer is present on the surface of a toner particle, a silanol group is present in part of the organosilicon polymer, and the amount of the silanol group is controlled.

Process cartridge and electrophotographic apparatus

An electrophotographic photosensitive member includes, in sequence, a support, a conductive layer, an undercoat layer, a charge generation layer, and a charge transport layer. The conductive layer is a cured film, and the cured film contains titanium oxide particles doped with niobium. The undercoat layer contains a cured product of a composition that contains an electron transport material having a polymerizable functional group and a resin functionalized with a carboxylic acid derivative.

There is provided an electrophotographic photosensitive member that can achieve both of an adequately high initial sensitivity as the electrophotographic photosensitive member and reduction in the fluctuation of a light portion potential at the time of repeated use. An electrophotographic photosensitive member includes a support, an electroconductive layer and a photosensitive layer in this order, wherein the electroconductive layer contains a binder material and a metal oxide particle; the metal oxide particle has a core material containing a titanium oxide, and a covering layer which covers the core material and contains the titanium oxide; and when the oxygen deficiency ratio of the metal oxide particle is represented by A, the oxygen deficiency ratio of the core material is represented by B, and the oxygen deficiency ratio of the covering layer is represented by C, the Expressions (1) and (2) are satisfied: A&#x2264;2% (1) and 10&#xd7;B&#x3c;C (2).

Provided is an electrophotographic photosensitive member that can achieve both of the suppression of a fluctuation in potential of the photosensitive member at the time of its repeated use, and the prevention of the occurrence of a black spot-like image defect at high levels. The electrophotographic photosensitive member includes in this order: a support; an intermediate layer; and a photosensitive layer, the intermediate layer containing particles each containing titanium oxide, and the particles having a mass increase ratio of 0.005% or more when heated under a nitrogen atmosphere from 300&#xb0; C. to 900&#xb0; C.

An electrophotographic photosensitive member includes an undercoat layer, a charge generation layer, and a charge transport layer in this order. The undercoat layer contains a cured product of a composition containing an electron transport material, a particle having an average primary particle size of 10 nm or more, and a silicone oil. A content of the particle in the undercoat layer is 3% by mass or more and 20% by mass or less. A content of the silicone oil in the undercoat layer is 0.01% by mass or more and 10% by mass or less relative to the content of the particle.

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

The present invention provides an electrophotographic photosensitive member in which a photosensitive layer has strong close adhesiveness even when used repeatedly, and a positive ghost is reduced. An undercoat layer of the electrophotographic photosensitive member contains a cured product of an electron transport material having a polymerizable functional group; a polyolefin resin having at least one group/structure selected from the group consisting of a carboxyl group, an alkoxycarbonyl group and an anhydrous carboxylic acid structure, and a substituted or unsubstituted phenyl group; and an isocyanate compound having two or more isocyanate groups.

An electrophotographic photosensitive member includes a support member, an undercoat layer, and a photosensitive layer adjacent to the undercoat layer in this order, wherein the undercoat layer contains a polymerized product of a composition including an electron transporting material having a polymerizable functional group, a cross-linking agent, and a thermoplastic resin having a polymerizable functional group, and at least one type of particles selected from the group consisting of resin particles having a hollow structure and rubber particles, wherein a content of the electron transporting material in the undercoat layer is 30% by mass or more with respect to a total mass of the composition, and wherein a content of the at least one type of particles in the undercoat layer is 10% by mass or more and 100% by mass or less with respect to the content of the electron transporting material.

A method for producing a carboxylic acid anhydride includes heating a composition containing a specific compound in a solvent to yield the carboxylic acid anhydride. The solvent is an aprotic polar solvent having a boiling point of 50&#xb0; C. or more.

Method for producing carboxylic acid anhydride, method for producing carboxylic imide, and method for manufacturing electrophotographic photosensitive member

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Suntou-gun, Japan

Kunihiko Sekido