Konica Minolta, Inc.

Konica Minolta Business Technologies, Inc.

Mayuko Matsusaki

Tomoko Sakimura

Hiroki Takao

Kengo Ikeda

Tomoo Sakimura

Shinichi Hamaguchi

Hiroshi Nakahara

Yasuko Uchino

Natsuko Fujisaki

Naoki Nozaki

Shinchi Hamaguchi

There is provided an electrophotographic photoreceptor obtained by sequentially laminating at least a photosensitive layer and an outermost layer on a conductive support, wherein the outermost layer contains a polymerized and cured product of a composition containing a polymerizable monomer and a filler, and the filler includes a conductive first filler surface-treated with a surface treatment agent having a silicone chain in a side chain, and a second filler having a relative dielectric constant which is lower than that of the first filler and 5 or less.

Electrophotographic photoreceptor

The present invention provides an electrophotographic image forming method using an electrophotographic photoconductor. The electrophotographic photoconductor has a protective layer. The surface of the protective layer has a projection structure. The average distance between neighboring projections among a plurality of projections R is set within the range of 100 to 250 nm. A toner including titanate compound particles attached to toner base particles is used.

Electrophotographic image forming method and electrophotographic image forming system

An electrophotographic photoreceptor includes a cured outermost layer that includes a polymerized cured product including at least an inorganic filler and a phenol derivative. The inorganic filler is surface-modified with a surface modifier. The phenol derivative has a structure represented by Formula (1).  In Formula (1), Rand Reach independently represent an alkyl group having three or more carbon atoms, Rand Reach independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and Lrepresents a linking group having at least 10 atoms with an atomic number of 12 or more.

An electrophotographic image forming apparatus includes: an electrophotographic photoreceptor; a charger that charges a surface of the electrophotographic photoreceptor; an exposer that exposes the charged electrophotographic photoreceptor; a developer that supplies a toner to the electrophotographic photoreceptor on which an electrostatic latent image is formed; a transferer that transfers a toner image formed on the electrophotographic photoreceptor; and a cleaner that removes a residual toner remaining on a surface of the electrophotographic photoreceptor, wherein the electrophotographic photoreceptor includes an outermost layer, a surface of the outermost layer has a projection structure due to a ridge of the inorganic filler, the toner contains toner base particles and metal oxide particles as an external additive externally added to the toner base particles, 70% or more of the toner base particles are covered with the metal oxide particles as the external additive, and following formulas (1) to (3) are satisfied. 

Electrophotographic image forming apparatus and electrophotographic image forming method

An electrophotographic photoreceptor includes an outermost layer formed of a polymerized cured product of a composition containing a polymerizable monomer and metal oxide particles surface-treated with a surface treatment agent having a silicone chain, wherein a ratio (r/r') between a number average primary particle diameter (r) of metal oxide particles which are untreated base particles of the metal oxide particles surface-treated with the surface treatment agent having a silicone chain and a sphere equivalent particle diameter (r&#x2032;) of the untreated base particles calculated from a specific surface area measured by a nitrogen adsorption method is 1.5 or more and 6.0 or less, and a surface treatment amount with the surface treatment agent having a silicone chain per surface area of the untreated base particles is 0.0005 g/mor more and 0.0015 g/mor less.

Electrophotographic photoreceptor, and electrophotographic image forming method and electrophotographic image forming apparatus using the same

An object of the present invention is to provide an image bearing member for electrophotography. The image bearing member has high mechanical properties which include abrasion resistance and scratch resistance, is excellent in toner releasability, and is capable of retaining these features. The present invention provides an image bearing member for electrophotography, which includes a surface layer, the surface layer being composed of a polymerization-cured product of a composition containing a polymerizable monomer and surface-treated metal oxide particles, and the surface-treated metal oxide particles are metal oxide particles surface-treated with a surface treating agent having a silicone side chain.

Image bearing member for electrophotography

Provided is an electrostatic latent image developing toner comprising toner matrix particles that comprise resin components comprising a vinyl resin as a main component and a crystalline resin, and a mold release agent. The electrostatic latent image developing toner includes a structural body in which a portion of the crystalline resin is in contact with the mold release agent, and a portion of the crystalline resin having a thread-like structure that is not in contact with the mold release agent, in cross-sections of the toner matrix particles.

Electrostatic latent image developing toner

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.

Electrophotographic photoconductor and image forming apparatus

The present invention provides an electrophotographic photoconductor that can improve unevenness in image density and reduce image defects such as fogging and dots. The electrophotographic photoconductor includes a conductive support, an intermediate layer, and a photosensitive layer. The intermediate layer includes metal oxide particles surface-treated with a titanium chelate compound represented by the following formula (1):Ti(OR)(L)&#x2003;&#x2003;(1)wherein R at each occurrence independently represents a Caliphatic hydrocarbon group; L at each occurrence independently represents a ligand derived from a chelating agent selected from the group consisting of &#x3b2;-ketoester represented by the following formula (1a): &#x3b2;-diketone represented by the following formula (1b): and a Calkylene glycol; n represents an integer of 1 to 3; if n is 2 or more, two Rs may be coupled to each other.

Electrophotographic photoconductor, process cartridge including the same, and image forming apparatus including the same

Reduced are interferential streaks in a halftone image, which are produced when using a cylindrical photoreceptor conductive substrate having been subjected to tool bit cutting processing, and provided are an electrophotographic photoreceptor capable of obtaining high image quality in response to a light printing field or the like and an image forming method employing the electrophotographic photoreceptor. Disclosed is an electrophotographic photoreceptor possessing a cylindrical substrate having been finished via cutting processing and provided thereon, a photosensitive layer, wherein among peaks other than at a lag of 0 in a correlogram of a substrate surface profile in a direction along a central axis of the substrate, a mean value from a maximum peak in height to a third peak in height is 0.3-0.8, each of the peaks in height corresponding to an autocorrelation coefficient.

Electrophotographic photoreceptor and image forming method

The present invention provides an electrophotographic photoconductor including an intermediate layer having sufficient electron transportability and blocking property and capable of suppressing image defects such as fogging and dots. The electrophotographic photoconductor according to the present invention includes a conductive support, a photosensitive layer disposed on the conductive support, and an intermediate layer disposed between the conductive support and the photosensitive layer, wherein the intermediate layer comprises metal oxide particles and a binder resin. The metal oxide particles are surface-treated with an alkoxysilane oligomer represented by the following Formula (1):SiO(OR)(OR)&#x2003;&#x2003;Formula (1) wherein Rand Reach individually represents a Calkyl group; n represents an integer of 2 to 20; and m and l each individually represents an integer of 0 or more and satisfies an equation of m+1=2n+2.

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Hino, Japan

Mayuko Matsusaki