Canon Kabushiki Kaisha

Yuya Tomomizu

Takumi Furukawa

Hiroaki Watanabe

Kenya Terada

Toshimitsu Nakazawa

Noriaki Kuroda

Kazuhiro Yamauchi

Yuichi Kikuchi

Noriko Nagamine

Satoru Nishioka

Kenji Takashima

Masahiro Kurachi

Toshiro Suzuki

Kazuhiro Gesho

Kenichi Yazawa

Masaki Yamada

Harunobu Ogaki

Kazunori Noguchi

Daisuke Miura

Tetsuo Hino

Tatsuya Yamaai

Shuhei Iwasaki

Masataka Kodama

Hiroki Masu

Noriko Suzumura

Hiroshi Inoue

Satoru Yamada

Akira Sakakibara

Kana Sato

Norifumi Muranaka

Masafumi Kyogaku

Yasuhiro Fushimoto

Provided is an electrophotographic electroconductive member including an electroconductive support and an electroconductive layer on the support, an electroconductive member is used, in which an electroconductive layer has a matrix comprising a first rubber, and domains dispersed in the matrix, the domains each comprising a second rubber and an electronic electroconductive agent, and for impedance measured by applying an AC voltage with an amplitude of 1 V to the electroconductive layer while varying frequencies between 1.0&#xd7;10Hz to 1.0&#xd7;10Hz under a specific environment, when a double logarithmic plot with a frequency on an abscissa and an impedance on an ordinate is obtained, a slope on a high frequency side is &#x2212;0.8 or more and &#x2014;0.3 or less, and the impedance a low frequency side is from 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;.

Electroconductive member, process cartridge, and image forming apparatus

A process for producing an electrophotographic electroconductive member having an electroconductive support and an electroconductive layer in the order mentioned. The electroconductive layer has a matrix including a crosslinked product of a first rubber, and a domain including a crosslinked product of a second rubber and an electroconductive particle, the process including the steps of: providing a rubber mixture for forming the domain, including carbon black and the second rubber by kneading the carbon black and the second rubber; providing a rubber mixture for forming the matrix, including the first rubber; kneading the rubber mixture for forming the domain and the rubber mixture for forming the matrix to prepare a rubber composition having a matrix-domain structure; forming a layer of the rubber composition on a surface of the electroconductive support; and curing the layer of the rubber composition on the surface of the electroconductive support to form the electroconductive layer.

Process for producing an electrophotographic electroconductive member

Provided is an electrophotographic electroconductive member including an electroconductive support and an electroconductive layer on the support, an electroconductive member is used, in which an electroconductive layer has a matrix comprising a first rubber, and domains dispersed in the matrix, the domains each comprising a second rubber and an electronic electroconductive agent, and for impedance measured by applying an AC voltage with an amplitude of 1 V to the electroconductive layer while varying frequencies between 1.0&#xd7;10Hz to 1.0&#xd7;10Hz under a specific environment, when a double logarithmic plot with a frequency on an abscissa and an impedance on an ordinate is obtained, a slope on a high frequency side is &#x2212;0.8 or more and &#x2212;0.3 or less, and the impedance a low frequency side is from 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;.

An electro-conductive layer of an electrophotographic electro-conductive member has a matrix-domain structure. The matrix contains a first rubber. The domain contains a second rubber and electro-conductive particles. Where &#x3bc; represents an average of ratios of the cross-sectional area of the electro-conductive particles contained in each of the domains to the cross-sectional area of each of the domains appearing on a cross-section of the electro-conductive layer in a thickness direction, and &#x3c3; represents a standard deviation of the ratios, &#x3c3;/&#x3bc; is 0 or more and 0.4 or less, and &#x3bc; is 20% or more and 40% or less. At least eight of samples with a first cubic shape 9 &#x3bc;m on a side, which are sampled at arbitrary nine positions on the electro-conductive layer, satisfy the specified condition.

Electro-conductive member, method for producing same, process cartridge and electrophotographic image forming apparatus

An electroconductive member for electrophotography has an electroconductive support and an electroconductive layer in the order mentioned. The electroconductive layer has a matrix including a crosslinked product of a first rubber, and a domain including a crosslinked product of a second rubber and an electroconductive particle. The impedance of an outer surface of the electroconductive member is 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;. 80% by number or more of domains observed at each of a total of nine 15-&#x3bc;m square observation regions, which are disposed at any three points in a thickness region from the outer surface to a specific depth on each of cross sections in a thickness direction at three points: the center of the electroconductive layer in the longitudinal direction and points at a specific distance from both edges of the electroconductive layer toward the center, satisfy specific requirements.

Electroconductive member, process cartridge, and electrophotographic image forming apparatus

An electrophotographic developing member includes an electro-conductive support and an electro-conductive layer provided on the support, wherein the electro-conductive layer has a matrix containing a first rubber and a plurality of domains dispersed in the matrix, and the domain contains a second rubber and an electronic conductive agent and when a frequency is log-log-plotted on a horizontal axis and an impedance is log-log-plotted on a vertical axis with respect to an impedance measured by applying an alternating current voltage having an amplitude of 1 V on the electro-conductive layer while changing a frequency between 1.0&#xd7;10Hz to 1.0&#xd7;10Hz under a specific environment, an inclination of an impedance on a high frequency side is &#x2212;0.8 or more and &#x2212;0.3 or less and an impedance on a low frequency side is 1.0&#xd7;10&#x3a9; to 1.0&#xd7;10&#x3a9;.

Developing member, process cartridge and electrophotographic apparatus

Provided is a process cartridge having a charging member and an electrophotographic photosensitive member to be charged by being in contact with the charging member, wherein the electrophotographic photosensitive member has a support and a photosensitive layer in this order, and a surface layer of the electrophotographic photosensitive member has a Martens hardness of 230 N/mmor less.

Process cartridge and electrophotographic apparatus

A charging member including an electro-conductive support; and an elastic layer, the elastic layer is a surface layer thereof and is constituted by a mono layer, the elastic layer includes domains and a matrix, an outer surface of the charging member is constituted by a surface of the matrix and surfaces of the domains, and the charging member has concave portions on the outer surface, the domains exist at bottom portions of the respective concave portions and are exposed to the outer surface of the charging member only at the bottom portions of the respective concave portions, the elastic layer has a volume resistivity of 1&#xd7;10&#x3a9;cm or more and 1&#xd7;10&#x3a9;cm or less, and Ais 20 times or more of A, wherein Aand Aare current values obtained by a prescribed method.

Charging member, manufacturing method of charging member, electrophotographic apparatus, and process cartridge

Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mmor more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mmor more and 20 N/mmor less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.

It is intended to provide a charging member capable of maintaining high charging performance even when used over a long period. The charging member has an electroconductive support and an electroconductive elastic layer as a surface layer, wherein the electroconductive elastic layer has a roughened surface, and the electroconductive elastic layer has an average Martens' hardness Mc of 2 N/mmor larger and 20 N/mmor smaller measured with an indentation strength of 0.04 mN at a core surface defined according to a three dimensional surface texture standard (ISO 25178-2:2012), and has an average viscosity Vc of 70&#xd7;10V or smaller measured in a square of 2 &#x3bc;m long&#xd7;2 &#x3bc;m wide field of view under a scanning probe microscope.

Charging member, method for producing same, process cartridge and electrophotographic image forming apparatus

The charging member includes: an electroconductive support; and an electroconductive elastic layer serving as a surface layer, wherein the elastic layer contains a binder, and holds electrically insulating hollow particles in such a state that at least a part of each of the hollow particles is exposed at a surface of the elastic layer, wherein the charging member has protrusions derived from the hollow particles in an outer surface of the charging member, and the outer surface of the charging member includes an outer surface of the elastic layer and an outer surface of an exposed portion of each of the hollow particles, and wherein the protrusions each have a depression in an outer surface of each of the protrusions, and an edge of the depression constitutes an apex in each of the protrusions.

Charging member, electrophotographic process cartridge, and electrophotographic image forming apparatus

An electrophotographic roller includes an electro-conductive shaft core including a metallic layer at its surface, and an elastic layer on the shaft core. When kinetic friction coefficients of an outer peripheral surface of each end portion of the shaft core with respect to polyester resin are measured for one rotation of the shaft core, an average value &#x3bc;r of the kinetic friction coefficients is 0.05 to 0.50. When each outer peripheral surface is divided into three equal ranges, defined as a region A1, a region A2, and a region A3, in a peripheral direction of the shaft core, each of the regions has a location where the kinetic friction coefficients fall within a range of 1.5 &#x3bc;r to 1.8 &#x3bc;r, and a location where the kinetic friction coefficients fall within a range of 0.2 &#x3bc;r to 0.5 &#x3bc;r.

Electrophotographic roller and charging apparatus

Provided a charging member comprising an electro-conductive support and an electro-conductive surface layer, the surface layer including on the outer surface thereof, concave portions that are independent of each other, and holding an insulating particle in each of the concave portions, the insulating particle being exposed to the surface of the charging member and forms a convex portion on the surface of the charging member, in an orthogonal projection image of which the concave portions and the insulating particle are projected on a surface of the electro-conductive support, a site in which an outer edge of a projection image derived from the insulating particle and an outer edge of a projection image derived from each of the concave portions are separated, exists, and a part of a wall of each of the concave portions constitutes a part of the surface of the charging member.

Charging member with concave portions containing insulating particles and electrophotographic apparatus

Provided a charging member including an electro-conductive support and a surface layer, the surface layer having in an outer surface thereof, concave portions and holding an elastic particle in each of the concave portions, the elastic particle being exposed at a surface of the charging member to form a convex portion in the surface of the charging member, and a part of a wall of each of the concave portions constituting a part of the surface of the charging member.

Charging member having outer surface with concave portions bearing exposed elastic particles, and electrophotographic apparatus

Provided is a charging member having a rough surface, thereby suppressing adhesion of dirt on the surface. A charging member having a supporting member, an elastic layer and a surface layer, in which the surface layer contains a polymer compound, which has a Si&#x2014;O-M bond and at least one structural unit selected from structural units represented by the following general formula (1) and the following general formula (2), and has a structural unit represented by the following general formula (3); the charging member has cracks developing from the surface thereof and reaching the elastic layer; and the cracks each have convexly raised edges, by which the surface thereof is roughened.MO&#x2003;&#x2003;General formula (1) 

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Yokohama, Japan

Yuya Tomomizu