Ricoh Company, Ltd.

Hirofumi Yamanami

Kenji Seki

Yukari Yamada

Satomi Mochizuki

Tamotsu Aruga

Katsuichi Ohta

Michio Kimura

Kiyoshi Masuda

Izumi Aiso

Koji Enomoto

Naoyuki Esaki

Junichiroh Hashimoto

Provided is an electrophotographic photoconductor including an electroconductive substrate, a photoconductive layer on the electroconductive substrate, and a protection layer on the photoconductive layer, wherein the protection layer contains two or more metal oxides having different average primary particle diameters, a binder resin, and a charge transporting material, the content of the metal oxides in the protection layer is 50% by mass or higher, and the average primary particle diameters of the metal oxides satisfy all of formula (I) to (III) below:(1)&#x3c;(2)&#x2003;&#x2003;formula (I);(1)/(2)&#x2266;0.25&#x2003;&#x2003;formula (II); and0.1 &#x3bc;m&#x2266;(2)&#x2003;&#x2003;formula (III)

Electrophotographic photoconductor, image forming apparatus, and process cartridge

An electrophotographic photoconductor, including an electrically conductive substrate, an undercoat layer containing a filler and a binder resin and provided on the substrate, and a photoconductive layer provided on the undercoat layer and containing a binder resin. At least one compound selected from crown ethers, polyalkyleneglycol ethers, polyethyleneglycol monocarboxylic acid esters, polyethyleneglycol dicarboxylic acid esters, and hydroxy-terminated random or block copolymers containing oxypropylene and oxyethylene groups is incorporated into (a) the undercoat layer or (b) into a charge generating layer of the photoconductive layer. In the case of (a), the photoconductive layer is a dried coating of a composition containing at least one solvent selected from cyclic ethers, ketones and aromatic hydrocarbons.

Electrophotographic photoconductor, process cartridge, image forming apparatus and image forming method

An electrophotographic photoconductor has an electroconductive support, and an undercoat layer and a photoconductive layer which are successively overlaid on the support, the undercoat layer containing an inorganic pigment and a crosslinked N-alkoxymethylated polyamide or a crosslinked material of an N-alkoxymethylated polyamide and a melamine resin as a binder resin. The method of producing the photoconductor is also disclosed. An electrophotographic image forming apparatus is provided with the aforementioned photoconductor, a charging unit, and a developing unit. A process cartridge is provided with the photoconductor, and at least one of a charging unit, a light exposure unit, a developing unit, or an image transfer unit. An electrophotographic image forming process has the steps of forming a latent electrostatic image on the photoconductor, and developing the latent electrostatic image to a visible image by reversal development.

Electrophotographic photoconductor, production process thereof, electrophotographic image forming method and apparatus, and process cartridge

A repeatedly usable electrophotographic photoconductor comprising (a) an electroconductive support, (b) an undercoat layer containing therein at least one salt selected from the group consisting of carboxylates, amino carboxylates, phosphates, polyphosphates, phosphites, phosphate derivatives, borates, sulfates and sulfites, and (c) a photoconductive layer, which layers are successively overlaid on the electroconductive support.

Electrophotographic photoconductor layered element comprising salt

This invention relates to a repeatedly usable photosensitive material for electrophotography, comprising an electroconductive substrate, a photosensitive layer and an intermediate layer located between said electroconductive substrate and said photosensitive layer, characterized in that said intermediate layer comprises an electroconductive polymer and an inorganic white pigment.

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Shizuoka, Japan

Hirofumi Yamanami