Ricoh Company, Ltd.

Minolta Company, Ltd.

Hideaki Yasunaga

Yoshihiro Mikuriya

Masayuki Hagi

Masahide Inoue

Kazuoki Fuwa

Hiroaki Katoh

Keiichiro Juri

Yoshitaka Sekiguchi

Tomoharu Nishikawa

Koichi Takenaka

Takuya Kadota

Hiroaki Kato

Atsushi Yamamoto

Katsunori Kurose

Minoru Nakamura

Yoshimichi Ishikawa

Makoto Kobayashi

Makoto Matsushita

Akira Izutani

Hiroaki Takahashi

Chiyoshi Nozaki

Ayano Momose

Yuri Haga

Tsuyoshi Nozaki

Hiroyuki Fukuda

Satoshi Ogawa

Hiroyuki Murakami

Hiroshi Shibano

Yoshiyuki Shimizu

Yoshitsugu Morita

Haruhiko Furukawa

Naoki Nakatake

Yoshie Iwakura

Hiroshi Ueki

Tomoharu Miki

Shuuichi Nakagawa

Osamu Maeda

Yuta Takeuchi

Yoshiaki Tanaka

Tsuyoshi Nokaki

A composition for seamless belt includes a thermoplastic resin; and a conductive agent. A liquid extracted from the composition with methanol has an intensity not greater than 7&#xd7;10in a total ion chromatogram.

Composition for seamless belt, and image forming apparatus using the belt

Provided is a developing roller including a shaft body, an elastic layer formed on an external circumference of the shaft body, and a surface layer formed on an external circumference of the elastic layer. The surface layer is formed of polyurethane containing a reaction product of a fluoroethylene vinyl ether copolymer and an isocyanurate form of isocyanate and having a film thickness of from 0.5 &#x3bc;m through 2.0 &#x3bc;m. The developing roller has grooves in a surface of the developing roller. The angle of the grooves from a circumferential direction is from 0 degrees through 30 degrees.

Developing roller, process cartridge, image forming apparatus and image forming method

A semiconductive resin composition includes at least two thermoplastic resins and a conductive filler. Each of the two thermoplastic resins has a sea-island structure, and 40% to 75% of the conductive filler are present in the thermoplastic resin in an island portion of the sea-island structure at an areal ratio of a cross section observed with a scanning electron microscope.

Semiconductive resin composition, member for electrophotography and image forming apparatus

A semiconductive resin composition includes a plurality of thermoplastic resins forming a sea-island structure including a sea portion and an island portion; and a plurality of conductive fillers. The sea portion includes at least two of the thermoplastic resins, at least one of the at least two of the thermoplastic resins is a copolymer, and the content of the copolymer is from 20% to 60% by weight per 100% by weight of the thermoplastic resins in the sea portion, and the following relation is satisfied:1.5&#x2266;&#x2266;10wherein A represents an average primary particle diameter of one of the conductive fillers having the smallest average primary particle diameter and B represents an average primary particle diameter of one of the conductive fillers having the largest average primary particle diameter.

A developing roller includes a conductive axis body; a conductive elastic layer overlying the conductive axis body; and a toner bearing layer overlying the conductive elastic layer and having a surface dispersed with particles having an average particle diameter of from 11 nm to 40 nm. The rotary torque is from 2.5 N to 3.5 N.

Developing roller, toner and image forming apparatus

An image forming apparatus includes at least an image bearer; an electrostatic latent image former to form an electrostatic latent image on the image bearer; an image developer to develop the electrostatic latent image with a toner to from a toner image; a first transferer to transfer the toner image from the image bearer onto an intermediate transfer belt; and a cleaner including a cleaning blade having a Martens hardness of from 0.8 to 10.0 N/m, to clean the intermediate transfer belt while contacting the surface of the intermediate transfer belt. The intermediate transfer belt includes a thermoplastic resin and a conductive resin, and has a surface concentration of oxygen atoms derived from the conductive resin, measured by XPS, of from 1.0% to 3.0% by atom.

Image forming apparatus

An intermediate transfer belt for use in electrophotography is provided. The intermediate transfer belt includes a thermoplastic resin having a vinylidene difluoride (VdF) structure. The intermediate transfer belt has a degree of crystallinity in the range of 17% to 39%.

Intermediate transfer belt

An intermediate transfer belt includes a thermoplastic resin and a fibrous material. The fibrous material has an orientation angle Fa of from 5&#xb0; to 30&#xb0; in a direction perpendicular to a circumferential direction of the intermediate transfer belt.

Intermediate transfer belt, and image forming apparatus using the belt

A developing device includes a developing roller including a base and a surface layer formed on the base, the surface layer including a polyurethane resin having a fluorine group and a polyfunctional isocyanurate structure, a toner storage chamber being partially in contact with the developing roller and to support the developing roller, and a sealing member provided at opposed ends of an end portion of the toner storage chamber in a rotating axis direction of the developing roller, and to seal in toner moving to the end portion of the toner storage chamber, the sealing member before use having a coefficient of static friction in a range of from 0.08 to 0.19.

Developing device, process cartridge, image forming apparatus, and image forming method

A developing roller, including: a shaft containing a metal; an elastic layer on a circumference of the shaft; and a surface layer on a circumferential surface of the elastic layer, wherein the surface layer contains: a polyurethane which is a reaction product between a fluoroethylene vinyl ether copolymer and an isocyanurate form of an isocyanate; and particles having an average primary particle diameter of 5 nm to 30 nm, and wherein the polyurethane has a peak intensity ratio of a NCO group to a hydroxyl group of 5.6 to 8.8 in an infrared absorption spectrum obtained by an attenuated total reflection method.

Developing roller, developing device, process cartridge, and image forming apparatus

A developing roller includes a core metal and an elastic layer formed on an outer circumference of the core metal. An outermost surface of the developing roller is roughened. A difference between a maximum value and a minimum value of an indentation power of the outermost surface is 10% to 21%, wherein the indentation power is measured by a micro-indentation test at 120 locations spaced 3 degrees apart on a circumference of the developing roller, which is at a center of the developing roller with respect to a longitudinal direction. A developing device and an image forming apparatus each include the developing roller.

Developing roller including a roughened outermost surface, and developing device and image forming apparatus including the same

A developing roller to bear toner thereon is provided. The developing roller includes a cylindrical electroconductive substrate; an electroconductive elastic layer located on a peripheral surface of the cylindrical electroconductive substrate; and a toner bearing layer located on a peripheral surface of the electroconductive elastic layer. The toner bearing layer includes a polyurethane resin, which is a reaction product of at least an isocyanate compound having an isocyanurate structure and a polyol at a NCO/OH molar ratio of from 90 to 110. The toner bearing layer has a water contact angle of from 135&#xb0; to 155&#xb0;, and a static friction coefficient of from 0.10 to 0.15.

Developing roller, and developing device, process cartridge and image forming method and apparatus using the developing roller

An image developer, including a developer container containing a developer developing a latent image on a latent image bearer; a developer bearer bearing the developer, located close to or contacting the latent image bearer; and a developer feeding and collection roller feeding the developer onto the developer bearer and scraping the developer therefrom, rotating while contacting thereto with pressure, wherein the developer feeding and collection roller includes an inner layer formed of an electroconductive foamed rubber; and an outer layer formed of an insulative foamed rubber, and wherein the following relationship is satisfied:&#x3b1;&#x2267;Twherein &#x3b1; represents a compression amount of the pressure of the developer feeding and collection roller to the developer bearer; and T represents a thickness of the outer layer, and wherein an offset voltage having a polarity opposite to that of the charged developer is applied to the developer feeding and collection roller.

Image developer, process cartridge, and image forming apparatus

A non-magnetic toner, including a binder resin; a wax present dispersing in the toner in the shape of a particle; and a colorant, wherein the wax having a particle diameter not less than 2.0 &#x3bc;m and less than 3.0 &#x3bc;m is not less than 20% and less than 40% by number based on total number thereof; the wax has a mode value not less than 1.5 &#x3bc;m and less than 2.0 &#x3bc;m in a frequency distribution of 0.1 &#x3bc;m width; and the following relationship is satisfied:45&#x3c;&#x3c;62wherein X represents a softening point (&#xb0; C.) of the toner; Y represents a volume-average particle diameter (&#x3bc;m) of the toner; and Z represents a total parts by weight of the wax included in 100 parts by weight of the toner.

Toner for non-magnetic one-component developer, method of preparing the toner, developer and image forming method

An image forming method, including charging the surface of an electrostatic latent image bearer by a charger; irradiating the surface of the electrostatic latent image bearer to form an electrostatic latent image thereon; developing the same with a toner to form a toner image; transferring the toner image onto a recording medium; and fixing the toner image thereon, wherein the charger is a charging roller contacting the electrostatic latent image bearer to charge the same, having a ten-point surface roughness of 5 to 30, and the toner includes a binder resin, a colorant, a release agent and an external additive including a composite oxide including titanium oxide in an amount of 80 to 95% by weight and silicon oxide, having a core-shell structure formed of a core including the titanium oxide and a shell including the silicon oxide and has a BET specific surface area of 50 to 100 m/g.

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Ibaraki, Japan

Hideaki Yasunaga