Kyocera Document Solutions Inc.

Kazutaka Sugimoto

Yuko Iwashita

Kazunari Hamasaki

Yukimasa Watanabe

Junichiro Otsubo

Kazuaki Ezure

Takafumi Matsumoto

Jun Azuma

Yuichi Yoshida

Keiji Maruo

Yasuhiro Oishi

Kazuaki Edure

Kazuki Ezure

An electrophotographic photosensitive member includes a conductive substrate, an intermediate layer provided on the conductive substrate, and a photosensitive layer provided on the intermediate layer. The intermediate layer contains a specific polyamide resin and specific inorganic particles. The specific inorganic particles each include a metal oxide particle and a surface treatment layer covering at least a part of the surface of the metal oxide particle. The surface treatment layers contain a component derived from an organic siloxane compound and at least one of aluminum oxide and silica. The specific polyamide resin includes a first repeating unit derived from an aliphatic dicarboxylic acid with a carbon number of at least 8 and no greater than 20 and a second repeating unit derived from a diamine compound with a cycloalkane structure.

Electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photosensitive member includes a photosensitive layer of a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. An optical response time is 0.05 milliseconds or longer and 0.85 milliseconds or shorter. The optical response time is a time from irradiation of a surface of the photosensitive layer charged to +800 V with pulse light having a wavelength of 780 nm to decay of a surface potential of the photosensitive layer from +800 V to +400 V. The pulse light has an intensity that allows the surface potential of the photosensitive layer to decay to +200 V from +800 V after 400 milliseconds elapse from the irradiation of the surface of the photosensitive layer charged to +800 V with the pulse light. The photosensitive layer has a Martens hardness at 50&#xb0; C. of at least 160 N/mm.

An electrophotographic photosensitive member includes a conductive substrate and a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, an additive, and a binder resin. An optical response time is in a range from 0.05 milliseconds to 0.85 milliseconds. The optical response time is a time from irradiation of a surface of the photosensitive layer charged to +800 V with pulse light having a wavelength of 780 nm to surface potential decay of the photosensitive layer from +800 V to +400 V. An optical intensity of the pulse light is set so that the surface potential of the photosensitive layer becomes +200 V from +800 V after 400 milliseconds from pulse light irradiation of the surface of the photosensitive layer charged to the +800 V. The additive includes either of both an ultraviolet absorbing agent and an antioxidant.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer of a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. An optical response time is at least 0.05 milliseconds and no greater than 0.85 milliseconds. The binder resin includes a polycarbonate resin including a repeating unit represented by general formula (1) shown below and a repeating unit represented by general formula (2) shown below. 

An electrophotographic photosensitive member includes a single-layer type photosensitive layer including phthalocyanine or a derivative thereof and an electron transport material. The electron transport material includes at least one first compound represented by formula (1) or (2) shown below and at least one second compound represented by formula (3), (4), or (5) shown below. A total amount of the at least one first compound and the at least one second compound is no less than 60 parts by mass and no greater than 120 parts by mass relative to 100 parts by mass of the binder resin. An amount of the at least one first compound is no less than 35 parts by mass and no greater than 80 parts by mass. An amount of the at least one second compound is no less than 25 parts by mass and no greater than 40 parts by mass. 

Electrophotographic photosensitive member, image forming apparatus, and process cartridge

An electrophotographic photosensitive member includes a photosensitive layer. The photosensitive layer contains a charge generating material and a hole transport material represented by general formula (1) shown below in a single layer. Titanyl phthalocyanine contained as the charge generating material exhibits a main peak at a Bragg angle 2&#x3b8;&#xb1;0.2&#xb0;=27.2&#xb0; in a CuK&#x3b1; characteristic X-ray diffraction spectrum and satisfies either (B) or (C), shown below, in a differential scanning calorimetry spectrum. (B) A peak is not present in a range from 50&#xb0; C. to 400&#xb0; C., other than a peak resulting from vaporization of adsorbed water. (C) A peak is not present in a range from 50&#xb0; C. to 270&#xb0; C., other than a peak resulting from vaporization of adsorbed water, and a peak is present in a range from 270&#xb0; C. to 400&#xb0; C. 

A positively chargeable electrophotographic photosensitive member has a photosensitive layer. The photosensitive layer at least includes the following layers layered in the stated order: (I) a charge transport layer at least containing a hole transport material and a binder resin; and (II) a charge generating-and-transporting layer at least containing a charge generating material, an electron transport material, a hole transport material, and a binder resin all within this layer. The binder resin contained in the charge transport layer is different from the binder resin contained in the charge generating-and-transporting layer, and either of the binder resins contains a polyvinyl acetal resin.

Positively chargeable electrophotographic photosensitive member and image forming apparatus

A single-layer-type electrophotographic photosensitive member includes a layer disposed on an electrically conductive substrate, the layer including at least a charge-generating material, an electron transport material, a hole transport material, and a binder resin within the same layer. The charge-generating material contains a phthalocyanine pigment and N-type pigments including at least a perylene-based pigment and an azo-based pigment, and the total amount of the N-type pigments is 0.03 to 10 parts by mass relative to 1 part by mass of the phthalocyanine pigment.

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Osaka, Japan

Kazutaka Sugimoto