Canon Kabushiki Kaisha

Canon Kasei Kabushiki Kaisha

Toshimitsu Nakazawa

Yuya Tomomizu

Hiroaki Watanabe

Takumi Furukawa

Kenya Terada

Kazuhiro Yamauchi

Yuichi Kikuchi

Kenji Takashima

Satoru Nishioka

Masahiro Kurachi

Masaki Yamada

Tetsuo Hino

Kenji Ishii

Hiroshi Inoue

Satoru Yamada

Takeshi Suzuki

Daisuke Yamada

Kana Sato

Norifumi Muranaka

Masafumi Kyogaku

Toshiro Suzuki

Yasuhiro Fushimoto

Hitoshi Kakii

Mie Takahashi

Kan Ikeda

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

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

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

A charging member includes a conductive mandrel, a semiconductive foamed elastic layer provided on the periphery of the mandrel, and a functional double-layer film provided on the periphery of the semiconductive foamed elastic layer. The semiconductive foamed elastic layer is a layer formed by making the mandrel and a semiconductive rubber composition standing uncured and unfoamed pass through a crosshead die of an extruder to set the composition on the periphery of the mandrel, followed by curing and foaming. The semiconductive rubber composition has a Mooney viscosity of from 15 to 30 and has a curing percentage of 40% or less when the foaming pressure reaches 50%. The functional double-layer film is a double-layer tube having a thin layer such that a tube formed out of only the layer is hard to use for covering. Also disclosed are a process cartridge and an electrophotographic apparatus which have such a charging member.

Growing community of inventors

Toride, Japan

Toshimitsu Nakazawa