Canon Kabushiki Kaisha

Masahiro Kurachi

Kazuhiro Yamauchi

Kenji Takashima

Yuichi Kikuchi

Satoru Nishioka

Takumi Furukawa

Hiroaki Watanabe

Yuya Tomomizu

Kenya Terada

Toshimitsu Nakazawa

Kana Sato

Masaki Yamada

Minoru Nakamura

Kazutoshi Ishida

Yoshitaka Suzumura

Hiroyuki Tomono

Tsuneyoshi Tominaga

Kosuke Fukudome

Kozue Uratani

Noriyoshi Umeda

Noriaki Kuroda

Dai Nozaki

Yuta Komiya

Yasuhiro Fushimoto

Taichi Sato

Shohei Tsuda

Motonari Ito

Osamu Matsushita

Shohei Kototani

Noriyuki Doi

Masataka Kodama

Hiroki Masu

Noriko Suzumura

Takuya Mizuguchi

Tomohiro Unno

Yuji Sakurai

Arihiro Yamamoto

Shunsuke Matsushita

Hideo Kihara

Masato Koyanagi

Issei Imamura

Genya Anan

Gosuke Goto

Hidenori Satoh

Shota Kaneko

Used is an electro-conductive member for electrophotography including: a support having an electro-conductive outer surface; and an electro-conductive layer on the outer surface of the support, wherein the electro-conductive layer includes: a matrix containing a first crosslinked rubber product and having a volume resistivity greater than 1.0×10Ωcm; and domains dispersed in the matrix, wherein the domain includes a second crosslinked rubber product and an electron conductive agent; and the electro-conductive layer includes a region T in which the volume resistivity of the matrix decreases in a depth direction from the outer surface of the electro-conductive member.

Electro-conductive member, process cartridge, and electrophotographic image forming apparatus

Provided an electrophotographic electro-conductive member that can stably suppress an occurrence of fogging in an electrophotographic image. The member comprises a support having an electro-conductive outer surface, and an electro-conductive layer on the outer surface of the support, the electro-conductive layer having a matrix including a cross-linked product of a first rubber, and domains dispersed in the matrix, the domains each includes a cross-linked product of a second rubber and an electro-conductive particle, at least some of the domains is exposed to the outer surface of the electro-conductive member to constitute protrusions on an outer surface of the member, the outer surface of the electro-conductive member is constituted by the matrix and the domains exposed to the outer surface of the electrophotographic electro-conductive member, the electrophotographic electro-conductive member has an impedance of 1.0×10Ω or more and 1.0×10Ω or less, and some of the domains satisfy two specific requirements.

Electrophotographic electro-conductive member, process cartridge, and electrophotographic image forming apparatus

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

An electrophotographic apparatus having an electrophotographic photosensitive member, a charging unit, and a developing unit for forming a toner image on a surface of the electrophotographic photosensitive member, wherein the charging unit has a conductive member disposed to be contactable with the electrophotographic photosensitive member; a conductive layer at the surface of the conductive member has a matrix and a plurality of domains dispersed in the matrix; at least a portion of the domains is exposed at the outer surface of the conductive member; the outer surface of the conductive member is constituted of at least the matrix and the domains; a volume resistivity R1 of the matrix is greater than 1.00&#xd7;10&#x3a9;&#xb7;cm; a volume resistivity R2 of the domains is smaller than R1; the developing unit contains the toner; and a dielectric loss tangent of the toner is at least 0.0027.

Electrophotographic apparatus, process cartridge, and cartridge set

An electrophotographic apparatus including an electrophotographic photosensitive member, a charging unit, and a developing unit, wherein the charging unit includes a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer of the conductive member has a matrix-domain structure, at least some of the domains are exposed at the outer surface of the conductive member, the volume resistivity RI of the matrix is greater than 1.00&#xd7;10&#x3a9;&#xb7;cm and not greater than 1.00&#xd7;10&#x3a9;&#xb7;cm, the matrix volume resistivity R1 is at least 1.0&#xd7;10-times the domain volume resistivity R2, and the developing unit includes a toner, the toner includes a binder resin-containing toner particle and an external additive, and the external additive contains fine particles of a hydrotalcite compound.

An electrophotographic apparatus having an electrophotographic photosensitive member, a charging unit, and a developing unit for forming a toner image, wherein the charging unit has a conductive member disposed to be contactable with the electrophotographic photosensitive member, a conductive layer at the surface of the conductive member has a matrix-domain structure, at least a portion of the domains is exposed at the outer surface of the conductive member, the outer surface of the conductive member is constituted at least of the matrix and these domains, a volume resistivity R1 of the matrix is greater than 1.00&#xd7;10&#x3a9;&#xb7;cm, a volume resistivity R2 of the domains is less than R1, Martens hardness G1 of the matrix and Martens hardness G2 of the domains satisfy a prescribed relationship, and an onset temperature T(A) for a storage elastic modulus E' of the toner is not more than 80.0&#xb0; C.

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 electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, the conductive layer at the outer surface of the conductive member comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the outer surface of the conductive member, the matrix has a volume resistivity R1 of larger than 1.00&#xd7;10&#x3a9;&#xb7;cm, the volume resistivity R1 of the matrix is 1.0&#xd7;10times or more a volume resistivity R2 of the domains, the developing device comprises the toner comprising a toner particle and a silica fine particle, and a coverage ratio of the toner surface with the silica fine particles is from 62.0% by area to 100.0% by area as determined by X-ray photoelectron spectroscopy.

Electrophotographic apparatus, process cartridge and cartridge set

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer of the conductive member comprises a matrix domain structure, at least a part of the domains Dt is exposed at the conductive member outer surface, the matrix has a volume resistivity R1 of larger than 1.00&#xd7;10&#x3a9;&#xb7;cm, the domains Dt has a volume resistivity of smaller than R1, the developing device comprises the toner, domains Dc formed of the crystalline material exist in a cross section of the toner, distances between adjacent wall surfaces of the domains Dc is from 30 to 1,100 nm, and a weight-average particle diameter D4 of the toner and distances Dms between adjacent wall surfaces between the domains Dt satisfies D4&#x2265;Dms.

The electro-conductive member has an electro-conductive support, and an electro-conductive layer in this order, the electro-conductive layer including a matrix and domains, the matrix constituted by a first rubber composition containing a cross-linked product of a first rubber, the domains having electro-conductivity, and dispersed in the matrix, each of the domains constituted by a second rubber composition containing a cross-linked product of a second rubber and an electro-conductive particle, the first rubber and the second rubber being diene-based rubbers, the first rubber having at least one monomer unit, the second rubber having at least one monomer unit different from the monomer unit which the first rubber has; a difference of absolute values of SP values between the first rubber and the second rubber is 0.2 (J/cm)to 4.0 (J/cm); and a tan &#x3b4;1/tan &#x3b4;2 is 0.45 to 2.00.

Electro-conductive member for electrophotography, process cartridge for electrophotography, 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

Provided an electrophotographic electro-conductive member that can stably suppress an occurrence of fogging in an electrophotographic image. The member comprises a support having an electro-conductive outer surface, and an electro-conductive layer on the outer surface of the support, the electro-conductive layer having a matrix including a cross-linked product of a first rubber, and domains dispersed in the matrix, the domains each includes a cross-linked product of a second rubber and an electro-conductive particle, at least some of the domains is exposed to the outer surface of the electro-conductive member to constitute protrusions on an outer surface of the member, the outer surface of the electro-conductive member is constituted by the matrix and the domains exposed to the outer surface of the electrophotographic electro-conductive member, the electrophotographic electro-conductive member has an impedance of 1.0&#xd7;10&#x3a9; or more and 1.0&#xd7;10&#x3a9; or less, and some of the domains satisfy two specific requirements.

An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging device, and a developing device, wherein the charging device comprises a conductive member arranged to be capable of contacting the electrophotographic photosensitive member, a conductive layer on the conductive member outer surface comprises a matrix and a plurality of domains dispersed in the matrix, at least some of the domains are exposed at the conductive member outer surface, the matrix has a volume resistivity of larger than 1.00&#xd7;10&#x3a9;&#xb7;cm and is 1.0&#xd7;10times or more one of the domains, the developing device comprises the toner comprising a toner particle, fine particles A and B, the fine particle A has a volume resistivity of 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;&#xb7;cm, and the fine particle B is silica fine particle and having a volume resistivity of 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;&#xb7;cm.

Provided an electro-conductive member that can be used as a charging member capable of preventing the emergence of a ghost image. The member comprises an electro-conductive support and an electro-conductive layer, the electro-conductive layer has a matrix including a first cross-linked rubber, and domains, the domains each includes a second cross-linked rubber and an electronically conductive agent, at least some of the domains are exposed to an outer surface of the member to constitute protrusions, the outer surface is constituted by the matrix and the exposed domains, and in a double logarithmic plot with a frequency on the abscissa and an impedance on the ordinate, a slope at a frequency of 1.0&#xd7;10Hz to 1.0&#xd7;10Hz is &#x2212;0.8 to &#x2212;0.3, and an impedance at a frequency of 1.0&#xd7;10Hz to 1.0&#xd7;10Hz is 1.0&#xd7;10to 1.0&#xd7;10&#x3a9;.

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Susono, Japan

Masahiro Kurachi