Konica Minolta, Inc.

Hiroshi Nakahara

Tomoo Sakimura

Shinichi Hamaguchi

Seijiro Takahashi

Keiichi Inagaki

Mayuko Matsusaki

Hiroshige Kidera

Provided is an electrophotographic photoreceptor including a conductive support having thereon an intermediate layer, a charge generating layer, a charge transporting layer, and a protective layer sequentially laminated in that order, wherein the intermediate layer contains rutile type titanium oxide particles, and 50% or more of the rutile type titanium oxide particles have an organic compound on a surface of the titanium oxide particles; the charge generating layer has a pigment containing a 2,3-butanediol adduct of a phthalocyanine compound; the charge transporting layer contains a charge transporting material having an ionization potential of 5.45 to 5.60 eV; and the protective layer contains metal oxide particles and the charge transporting material in a cured resin prepared by curing a polymerizable compound.

Electrophotographic photoreceptor and image-forming apparatus

An electrophotographic image forming apparatus using an organic photoreceptor in which at least a charge generation layer, a charge transport layer, and a protective layer are laminated in order on a conductive support includes at least a unit for supplying a lubricant onto a surface of the organic photoreceptor and a unit for removing toner remaining on the surface of the organic photoreceptor with a cleaning blade, and satisfying the following conditions (1) to (3): (1) the protective layer of the organic photoreceptor contains at least metal oxide fine particles in a cured resin obtained by curing a polymerizable compound; (2) a universal hardness of the surface of the organic photoreceptor is in a range of 220 to 280 N/mm; and (3) a JIS-A hardness of a portion of the cleaning blade to be abutted on the organic photoreceptor is in a range of 70 to 78&#xb0;.

Electrophotographic image forming apparatus containing organic photoreceptor, unit for supplying lubricant, and cleaning blade

Disclosed is a production process of an organic photoreceptor which can suppress occurrence of uneven density and image defects. The production process of an organic photoreceptor, the organic photoreceptor including an intermediate layer and an organic photosensitive layer on the intermediate layer, includes: applying a coating liquid for forming the intermediate layer to a conductive support to form a coating film, the coating liquid being obtained by dissolving a binder resin in a solvent and dispersing first and second metal oxide fine particles therein; and drying the coating film. The Pe number of the first metal oxide fine particles is two or more times larger than that of the second metal oxide fine particles.number=(6&#x3c0;&#x3bc;)/&#x2003;&#x2003;Equation (1):

Production process of organic photoreceptor

The present invention provides an electrophotographic photoconductor including an electrically conductive substrate, an intermediate layer, and a photosensitive layer that are formed on the electrically conductive support, the intermediate layer including first titanium oxide particles surface-treated with a first reactive organic silicon compound, second titanium oxide particles surface-treated with a second reactive organic silicon compound different from the first reactive organic silicon compound, and a binder resin. The first reactive organic silicon compound is methyl hydrogen polysiloxane. The second reactive organic silicon compound is a compound represented by the following general formula (1):R&#x2014;Si&#x2014;(X)&#x2003;&#x2003;(1)R represents a alkyl group having 1 to 10 carbon atoms substituted by at least one of acryloxy and methacryloxy groups or unsubstituted; and X represents an alkoxy group having 1 to 4 carbon atoms or a halogen atom.

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Hachioji, Japan

Hiroshi Nakahara