Fuji Xerox Co., Ltd.

Fumiaki Tambo

Yasuo Sakaguchi

Katsumi Daimon

Kazuo Yamasaki

Hiroyuki Tanaka

Katsuhiro Sato

Kaoru Torikoshi

Yutaka Akasaki

Yasuhiro Yamaguchi

Masakazu Iijima

Ryosaku Igarashi

Taketoshi Hoshizaki

Masahiro Iwasaki

Taketoshi Higashi

An electrophotographic photoreceptor having a bipolar charge transport layer with a hole-transporting property and an electron-transporting property, the bipolar charge transport layer containing a block copolymer or a graft copolymer, and a process cartridge and an electrophotographic apparatus using the electrophotographic photoreceptor. The electrophotographic photoreceptor has a high performance and a long life and can provide various properties required for a photoreceptor by forming, the bipolar charge transport layer which is excellent in hole- and electron-transporting properties, mechanical strengths, a discharge product resistance and a coating dispersion stability, and the process cartridge and the electrophotographic apparatus using the electrophotographic photoreceptor can provide a high performance and a high durability.

Electrophotographic photoreceptor, process cartridge and electrophotographic apparatus using the same

A resistive element is produced by forming a substrate glazed with glass, printing or coating a resistive element-forming paste onto the substrate, calcining the paste in a first heating step to form an element comprising a film on the substrate and subjecting the resulting element to a heat treatment in a second heating step to diffuse an amount of glass into the film to increase resistivity of the element.

Process for producing a resistive element by diffusing glass

A charge transporting block and an insulating block are block copolymerized or graft copolymerized to form a charge transporting copolymer. The charge transporting polymers may be used in an electrophotographic photoreceptor and an electrophotographic device.

Charge-transporting copolymer, method of forming charge-transporting

Hydroxygallium phthalocyanine crystals and an electrophotographic photoreceptor comprising the same. The hydroxygallium phthalocyanine crystals contain at least one of a polar organic solvent selected from the group consisting of a compound having an amido group, a compound having a sulfoxide group, and an organic amine.

Hydroxygallium phthalocyanine crystals and electrophotographic

An excellent electrographic photosensitive member having a high sensitivity, a high chargeability and a low residual potential. The electrographic photosensitive member comprises a photosensitive layer, or a photosensitive layer and an underlayer superimposed over an electroconductive support, wherein the photosensitive layer and/or the underlayer contain a chlorogallium phthalocyanine which is substituted with an electron-withdrawing group and has the following formula: ##STR1## where X represents an electron-withdrawing group such as a halogen atom and n is an integer of 2 to 4.

Electrographic photosensitive member

Hydroxygallium phthalocyanine crystals having intense diffraction peaks at Bragg angles (2.theta..+-.0.2.degree.) of 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree. in Cuk.alpha. characteristic X-ray diffractometry, a process for producing the same, and an electrophotographic photoreceptor containing the same are disclosed. The hydroxygallium phthalocyanine crystals are obtained by once preparing impurity-free hydroxygallium phthalocyanine having intense X-ray diffraction peaks at specific Bragg angles, followed by a solvent treatment for crystal transformation, in which the impurity-free crystals are prepared by using excess phthalocyanine ring-forming compound in the synthesis of starting gallium phthalocyanine or by removing insoluble matter from the acid paste of starting gallium phthalocyanine.

Hydroxygallium phthalocyanine crystal, and electro-photographic

Hydroxygallium phthalocyanine crystals having intense diffraction peaks at Bragg angles (2.theta..+-.0.2.degree.) of 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree. in CuK.alpha. characteristic X-ray diffractometry, a process for producing the same, and an electrophotographic photoreceptor containing the same are disclosed. The hydroxygallium phthalocyanine crystals are obtained by once preparing impurity-free hydroxygallium phthalocyanine having intense X-ray diffraction peaks at specific Bragg angles, followed by a solvent treatment for crystal transformation, in which the impurity-free crystals are prepared by using excess phthalocyanine ring-forming compound in the synthesis of starting gallium phthalocyanine or by removing insoluble matter from the acid paste of starting gallium phthalocyanine.

Hydroxygallium phthalocyanine crystal, process for producing the same,

A resistive element film-forming paste includes (1) an organic metal compound, (2) at least one organic non-metal additive, and (3) a solution of asphalt in a solvent. A resistive element is formed by coating the paste on a substrate followed by calcining.

Paste for resistive element film

A resistive film-forming composition to be coated on a substrate and calcined to form a resistive film is disclosed, which contains an organic iridium compound selected from a compound represented by formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom, an alkyl group, or an alkoxy group, a compound represented by formula (II):

Resistive film-forming composition and electronic components using the

A process for producing a tungsten oxide film which comprises the steps of: reacting a tungstate with a salt of an organic compound represented by formula (I) to obtain a tungstic acid compound; mixing the tungstic acid compound with an organic solvent to prepare a composition; and removing an organic substance and the solvent from the composition:

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Minami-ashigara, Japan

Fumiaki Tambo