Kyocera Document Solutions Inc.

Akihiko Ogata

Jun Azuma

Kensuke Okawa

Keiji Maruo

Takahiro Oki

Hideki Okada

Tomofumi Shimizu

Junichiro Otsubo

Kenji Kitaguchi

A polyarylate resin includes at least one type of repeating unit represented by a general formula (1), at least one type of repeating unit represented by a general formula (2), and a terminal group represented by a general formula (3). R, R, R, and Reach represent, independently of one another, a hydrogen atom or a methyl group. Rand Reach represent, independently of each other, a hydrogen atom or a Calkyl group. Rand Rmay bond together to represent a Ccycloalkylidene group. Xrepresents a divalent group represented by a chemical formula (2A), (2B), (2C), or (2D) with the proviso that when only one type of repeating unit represented by the general formula (2) is included, Xdoes not represent a divalent group represented by the chemical formula (2D). Rrepresents a chain aliphatic group having at least one fluoro group. 

Polyarylate resin and electrophotographic photosensitive member

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer contains at least a charge generating material, a charge transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin is represented by general formula (1) shown below. In general formula (1), X represents a divalent group represented by chemical formula (1-1), (1-2), (1-3), or (1-4) shown below. 

Electrophotographic photosensitive member

A multi-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer. The charge generating layer contains a charge generating material. The charge transport layer contains a charge transport material, a binder resin, and silica particles. The charge transport layer is a monolayer. The charge transport layer is disposed as an outermost surface layer of the multi-layer electrophotographic photosensitive member. The silica particles have a content of at least 0.5 parts by mass and no greater than 15 parts by mass relative to 100 parts by mass of the binder resin. The binder resin includes a polyarylate resin. The polyarylate resin has a repeating unit represented by general formula (I) shown below. In general formula (I), R-Rand Y are defined as those described in the specification. 

Multi-layer electrophotographic photosensitive member

A multi-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer. The charge generating layer contains a charge generating material. The charge transport layer contains a hole transport material and a binder resin. The charge generating material contains a titanyl phthalocyanine that exhibits a main peak at a Bragg angle (2&#x3b8;&#xb1;0.2&#xb0;) of 27.2&#xb0; in a CuK&#x3b1; characteristic X-ray diffraction spectrum. The hole transport material contains a triarylamine derivative represented by generic formula (1). The hole transport material has a mass ratio of at least 0.30 and no greater than 0.55 relative to the binder resin in the charge transport layer. In general formula (1), R, R, l, and m are the same as those defined in the specification. 

Multi-layer electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photosensitive member has a photosensitive layer. The photosensitive layer is a multi-layer photosensitive layer having a charge transport layer being an outermost layer or a single-layer photosensitive layer. The amount of silica particles contained in the photosensitive layer is at least 0.5 parts by mass and no greater than 15 parts by mass relative to 100 parts by mass of a binder resin contained in the photosensitive layer.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer located on the charge generating layer. The charge transport layer contains a pigment that is absorptive with respect to a wavelength of exposed light. The pigment is a metal phthalocyanine pigment represented by General Formula (I) or a metal-free phthalocyanine pigment represented by General Formula (II), where X represents a sulfur atom or an oxygen atom. Rrepresents an aryl group or an alkyl group. R-Reach represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a phenoxy group, an alkylthio group, a phenylthio group, or a dialkylamino group. M represents a metal atom. Y represents non-substitution or an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, an oxygen atom, or a hydroxyl group. 

An electrophotographic photosensitive member includes a photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, and a binder resin. The hole transport material contains an amine stilbene derivative represented by a general formula (1), and the binder resin contains a polycarbonate resin represented by a general formula (2). 

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Osaka, Japan

Akihiko Ogata