Fuji Xerox Co., Ltd.

Masaru Miura

Masanori Ichimura

Takashi Imai

Satoshi Inoue

Yasuo Yamamoto

Yutaka Sugizaki

Michio Take

Susumu Saito

Koji Fukushima

Hirotaka Matsuoka

Manabu Serizawa

Hidemi Nukada

Shinya Yamamoto

Hideyuki Akagi

Masayuki Takei

Takahiro Suzuki

Hiroshi Nakazawa

Hiroshi Takayama

Seiji Ashiya

Hitoshi Takimoto

Toshiaki Murofushi

Isamu Ishiko

Tetsuya Ezumi

Tetsunao Koujiri

An electrophotographic photoreceptor includes a conductive substrate, and at least a photosensitive layer on the conductive substrate, a layer located at a surface of the photosensitive layer side of the electrophotographic photoreceptor contains fluorine containing resin particles and a fluoro graft polymer having a fluoroalkyl group having 1 to 7 carbon atoms, and an area for a polystyrene equivalent molecular weight of 700,000 or more is from about 5% to about 20% of the total area in a gel permeation chromatography (GPC) chart for the fluoro graft polymer.

Electrophotographic photoreceptor, process cartridge, and image forming apparatus

An electrophotographic photoreceptor comprising at least a photosensitive layer on an electroconductive substrate, a surface layer of the electrophotographic photoreceptor including a fluorinated alkyl group-containing copolymer having repeating units represented by the following formulae A and B, and fluorine-based resin particles:  wherein in Formulae A and B, l, m and n each independently represent a integer number of 1 or more; p, q, r and s each independently represent 0 or an integer of 1 or more; t represents an integer of from 1 to 7; R, R, R, and Reach independently represent a hydrogen atom or an alkyl group; X represents an alkylene chain, a halogen-substituted alkylene chain, &#x2014;S&#x2014;, &#x2014;O&#x2014;, &#x2014;NH&#x2014; or a single bond; Y represents an alkylene chain, a halogen-substituted alkylene chain, &#x2014;(CH(OH))&#x2014; or a single bond; and z represents an integer of 1 or more.

Electrophotographic photoreceptor, process cartridge and image forming apparatus

A surface-treated inorganic fine particle includes an inorganic fine particle, a hydrophobizing agent deposited on the surface of the inorganic fine particle and an amino group-containing coupling agent deposited on the surface of the inorganic fine particle, wherein the hydrophobizing agent and the amino group-containing coupling agent in a ratio of 1/(0.01 to 0.1) by weight are deposited on the surface of the inorganic fine particle by treating the surface of the inorganic fine particle with the hydrophobizing agent and the amino group-containing coupling agent. An electrophotographic developer contains toner particles and the surface-treated inorganic fine particles.

Surface-treated inorganic fine particle and electrophotographic

A color toner providing a toner image excellent in brightness, clearness and graininess and a process for producing the same are disclosed, wherein a proportion of dispersed pigment particles having a circle-equivalent diameter of 0.3 .mu.m or greater does not exceed 0.1% of the total number of said dispersed pigment particles. The process comprises kneading a water-containing pigment paste and a binder resin at a temperature of 100.degree. C. or higher under pressure in a heat and pressure kneader to remove a water content to obtain a pigment dispersion, melt-kneading the resulting pigment dispersion together with a binder resin, and grinding the mixture.

Color toner and process for producing the same

An electrophotographic photoreceptor comprising a conductive substrate having thereon a photosensitive layer is disclosed, said photosensitive layer containing, as a binder resin, a polycarbonate resin comprising at least a repeating unit represented by formula (I): ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 each represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 5 carbon atoms, a cycloalkyl group having from 5 to 7 carbon atoms or a phenyl group; and R.sub.5 and R.sub.6 are taken together to form a 5- to 8-membered carbonaceous ring substituted with at least two alkyl groups each having from 1 to 5 carbon atoms. The photoreceptor has high mechanical durability and satisfactory surface smoothness, resistance against reduction in image quality and sensitivity, and stability against environmental change and repeated use.

Electrophotographic photoreceptor having high mechanical durability

An electrophotographic toner composition comprising (A) toner particles with an average particle diameter of 9 .mu.m or less comprising at least a binder resin and a colorant, and (B) an additive, wherein the additive is a fine metal oxide powder surface coated with at least one agent for imparting hydrophobic property selected from the group consisting of the following formulae (1), (2) and (3):

Electrophotographic toner composition

A toner for developing an electrostatic charge image is disclosed, which is formed by adding and mixing an external additive with toner particles having an average particle size of not larger than 9 .mu.m and comprising at least a colorant and a binder resin, wherein the external additive is fine particles having a particle size of 20 to 80 nm. There is also disclosed a process for preparing the toner which comprises adding external additives to the toner particles and mixing them, wherein the addition and mixing of said external additive are carried out under specific conditions.

Toner for developing electrostatic charge image and process for

A positively chargeable carrier for developing electrostatic charge images having good surface staining resistance and good environmental reliance of charging is disclosed, which comprises a core material having formed thereon an interlayer having a triboelectrification controlling function and having a nitrogen atom content of from 5 ppm to 75 ppm based on the weight of the core material, and a releasable coated layer formed on the interlayer. A two-component developer using the carrier is also disclosed.

Positively chargeable carrier

A carrier for magnetic brush developer comprising a core material having coated thereon a coated layer containing a graft copolymer comprising a polymer of a nitrogen-containing vinyl monomer or a phosphorus-containing vinyl monomer having a molecular weight of from 1,000 to 5,500 graft-copolymerized thereto a vinyl monomer.

Growing community of inventors

Kanagawa, Japan

Masaru Miura