Canon Kabushiki Kaisha

Keiji Nose

Hiroaki Watanabe

Masaaki Harada

Takumi Furukawa

Kenya Terada

Taichi Sato

Toshiro Suzuki

The present invention provides a charging member having an elastic layer on a surface thereof in which occurrence of compression set is reduced. The charging member includes an electro-conductive support and an elastic layer provided on the support as a surface layer, wherein the elastic layer is a rubber layer made of a crosslinked product of a rubber mixture including acrylonitrile butadiene rubber and polybutadiene, the polybutadiene includes 1,2-syndiotactic polybutadiene, and the elastic layer is formed by irradiating a surface of the rubber layer with electron rays.

Charging member, process cartridge and electrophotographic apparatus

The present invention provides a charging member which has a low compression set and which can suppress the generation of image defects. A layer of an unvulcanized rubber composition including an unvulcanized acrylonitrile butadiene rubber and N,N'-methylenebis(1,4-phenylene)dimaleimide is vulcanized.

Charging member and electrophotographic apparatus

To provide a charging member that can not easily cause faulty cleaning on a photosensitive member while having a flexibility high enough to form a nip between it and the photosensitive member in a sufficient width. The charging member has an electro-conductive support and an elastic layer that is a surface layer, which elastic layer has at its surface a region having been cured by irradiation with electron rays, where this region supports spherical polyethylene particles in such a state that the spherical polyethylene particles are exposed to the surface of the elastic layer, thereby making the surface roughened.

Charging member, process for its production, and electrophotographic apparatus

Provided is a charging member capable of suppressing occurrence of compression set while having flexibility enough to ensure a nip with a photosensitive member. The charging member comprises a support and an elastic layer, wherein the elastic layer has an MD-1 hardness of from 55 to 85&#xb0; at the surface thereof, and has a universal hardness of 2.0 to 20.0 N/mmat an indentation depth of 5 &#x3bc;m from the surface thereof.

Charging member, manufacturing method therefor, and electrophotographic apparatus

A charging member is provided which has a low electrical resistance, has less non-uniformity or environmental dependence of the electrical resistance, may less undergo electrification deterioration even when used for a long period of time, and is free of any occurrence of faulty images such as horizontal lines attributable to charging. The charging member is formed of a support with a good electrical conductivity and an elastic layer consisting of at least one layer on the support, and the elastic layer is formed of a semiconductive vulcanized rubber in which carbon black has been dispersed as conductive particles in a binder polymer containing a polymer having a butadiene skeleton, having been modified at a molecular terminal thereof with a specific atomic group.

Charging member, electrophotographic apparatus and process cartridge

A roller for electrophotography has an electrically conductive support and an elastic layer as a surface layer. The elastic layer holds spherical particles each having a plane on their peripheral surfaces, in such a way that part or the whole of the plane comes exposed to the surface of the elastic layer, and the plane of each of the spherical particles standing exposed to the surface of the elastic layer and a plane that is i) orthogonal to a straight line passing through an axis of a section orthogonal to an axis of the roller for electrophotography and being directed toward the peripheral surface of the roller for electrophotography and is ii) tangential to the peripheral surface of the roller for electrophotography form an acute internal angle.

Charging roller and process for its production

To provide a charging member that can have a uniform electrical resistance, can not easily change in electrical resistance even by any long-term continuous electrification and, as a result thereof, may cause less change in its charging performance with time. A charging member having a conductive support and an elastic-material layer; the elastic-material layer comprising a vulcanized rubber; the vulcanized rubber being a vulcanized product of a composition which comprises i) a binder polymer comprising a polymer having a butadiene skeleton and ii) carbon black as electrically conductive particles; and the polymer having a butadiene skeleton has a molecular terminal modified with an atomic group having a specific structure.

Charging member with vulcanized rubber, and electrophotographic apparatus including the charging member

An electrophotographic member including an electrically conductive substrate and an electrically conductive resin layer corresponding to a surface layer. The resin layer includes electrically conductive particles and a binder resin. The binder resin is a polymer in which a polymer chain having at least one unit selected from the group consisting of units represented by the following formulas (1) and (2) and at least one unit selected from the group consisting of units represented by the following formulas (3) and (4) is crosslinked by at least one organopolysiloxane chain selected from the group consisting of structures represented by the following formulas (5) and (6): 

Electrophotographic member, method for producing the same, process cartridge and electrophotographic apparatus

The conductive member has a conductive support and a conductive elastic layer. The elastic layer is a mixture containing an electron conductive agent and a binder polymer, or a cured product thereof, and the electron conductive agent contains a carbon black satisfying the following characteristics: (i) an average primary particle diameter is 20 nm or more and 30 nm or less; (ii) a DBP oil absorption is 40 ml/100 g or more and 70 ml/100 g or less, and the total amount of CO and COgenerated by temperature programmed desorption/mass spectrometry is 0.30 mass % or more and 0.80 mass % or less with reference to the carbon black; and (iii) the amount of SOgenerated by the temperature programmed desorption/mass spectrometry is 0.05 mass % or more with reference to the carbon black.

Conductive member, electrophotographic apparatus, and process cartridge

To provide a charging member that can not easily cause faulty cleaning. A charging member having a conductive support and an elastic layer that is a surface layer; the elastic layer having on its surface a region having been cured by irradiation with electron rays, where the region having been cured supports at least one type of spherical particles of spherical silica particles, spherical alumina particles and spherical zirconia particles in such a state that the spherical particles are exposed at least in part to the surface of the elastic layer so as to make the surface roughened.

Provided is a charging member which hardly causes a cleaning failure in a photosensitive member while having such flexibility that a sufficient nip width can be formed with respect to a photosensitive member. The charging member comprises: an electro-conductive support; and an elastic layer as a surface layer, wherein: the elastic layer has a hardened region formed by irradiation with an electron beam; and the hardened region supports a composite particle in a state in which the composite particle is exposed on the surface of the elastic layer, thereby roughening the surface of the elastic layer, and wherein: said composite particle includes a silica-containing porous particle whose surface is coated with a carbon-containing film.

Charging member, manufacturing method for charging member, and electrophotographic apparatus

To provide a charging member that can not easily change in electrical resistance even by any long-term continuous application of direct-current voltage and, as a result thereof, may cause less change in its charging performance with time. The charging member has an electrically conductive support and an electrically conductive elastic layer. The elastic layer contains a vulcanized rubber. The vulcanized rubber is a vulcanized product of a mixture which contains i) a binder polymer containing a polymer having a butadiene skeleton and ii) carbon black, where the polymer having a butadiene skeleton stands modified at the molecular terminal(s) thereof with a group represented by the following formulas (1) or (2). 

Charging member

A conductive rubber elastic material is stably provided which can produce a charging member that may less vary in electrical resistance even with changes in applied voltage, promises uniform electrical properties, has charge characteristics not affected by changes in environments such as temperature and humidity, and enables a charging object member such as a photosensitive member to be kept from being contaminated. It is a conductive rubber elastic material which contains a matrix containing at least one ionically conductive rubber selected from the group consisting of epichlorohydrin rubber, epichlorohydrin-ethylene oxide rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether rubber, acrylonitrile-butadiene rubber and a hydrogenated product of acrylonitrile-butadiene rubber and domains composed of an electronically conductive rubber material containing i) a rubber having a butadiene skeleton and ii) carbon black, and the rubber having a butadiene skeleton is modified at a molecular terminal thereof with a specific atomic group.

Conductive rubber elastic material, charging member and electrophotographic apparatus

Provided is a charging member having an elastic layer to which components derived from a developer hardly adhere even when the charging member is used for a long time period and in which elastic layer the occurrence of compression set is suppressed The charging member includes: a electroconductive support; and a electroconductive elastic layer, in which the elastic layer is formed through irradiation of an electron beam onto a surface of a rubber layer formed of a crosslinked product of a rubber mixture containing an acrylonitrile-butadiene rubber and a styrene-butadiene rubber; the styrene-butadiene rubber has a 1,2-vinyl bond, and at least one selected from a cis-1,4 bond and a trans-1,4 bond; and a ratio of the numbers of moles of the 1,4 bonds to a total number of moles of the 1,2-vinyl bond, the cis-1,4 bond, and the trans-1,4 bond is 31 mol % or more and 61 mol % or less.

Provided is a charging member in which the hardness of its surface is increased while surface free energy is kept low, the surface is hard to scratch even in long-term use, and a toner or the like is hard to adhere to the surface. The charging member according to the present invention includes a conductive support, a conductive elastic layer, and a surface region containing a cured material of a compound represented by the following formula (1): wherein n represents an integer of 0-6, m represents an integer of 0-6, the total of n and m is from 2 to 6, x and y each independently represent an integer of 0-4, and Rand Reach independently represent a hydrogen atom or a methyl group.

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Suntou-gun, Japan

Keiji Nose