Canon Kabushiki Kaisha

Hiroki Masu

Noriko Suzumura

Kenichi Yamauchi

Kazuhiro Yamauchi

Masataka Kodama

Satoru Nishioka

Noriyuki Doi

Noriaki Kuroda

Kineo Takeno

Masahiro Kurachi

Yuya Tomomizu

Hiroshi Mayuzumi

Taichi Sato

Yuichi Kikuchi

Takumi Furukawa

Masaki Tsunoda

A charging member includes an electro-conductive substrate, an elastic layer, and a surface layer provided in this order. The elastic layer has, on an outer surface thereof, concave portions that are independent of each other, and hold insulating particles. The insulating particle is exposed to the surface of the elastic layer. A site in which an outer edge of the projection image derived from each of the insulating particles and an outer edge of a projection image derived from each of the concave portions are separated, exists. The charging member has convex portions derived from the insulating particles exposed to the surface of the elastic layer, and concave portions derived from the concave portions of the elastic layer. The surface layer has a volume resistivity of 1.0&#xd7;10&#x3a9;cm or more.

Charging member, process cartridge, electrophotographic image forming apparatus, and method for manufacturing charging member

A charging member which has high charging ability and prevents generation of abnormal discharge is provided. The charging member includes a support and a surface layer. The surface layer contains a polymetalloxane having a specific structure.

Charging member, process cartridge and electrophotographic apparatus

Provided is a charging member that suppresses the occurrence of abnormal discharge under low temperature and low humidity. The charging member includes a support and a surface layer on the support, and the surface layer contains a compound represented by the following formula (a), (b), (c), or (d). 

Charging member, process cartridge, and electrophotographic image forming apparatus

A charging member capable of inhibiting the effect of the contact mark on the electrophotographic image, even after in contact with another member for a long term, is provided. The charging member has a surface layer on a support, the surface layer containing a polymer compound having a structural unit represented by the following formula (1):  In the formula (1), A represents an aromatic cyclic hydrocarbon group; Rrepresents a specific hydrocarbon group. L represents a polysiloxane having at least one of an SiOunit (T) and an SiOunit (D). U represents an integer of 1 or more.

Charging member, process cartridge, and electrophotographic apparatus

Provided is an electroconductive member for electrophotography having a stable charging ability. The electroconductive member includes, in this order, an electroconductive substrate, an electroconductive elastic layer, and a surface layer. The surface layer contains a polymer having a urethane linkage. The polymer has, in the molecule, structures included in at least two groups selected from: Group A of structures each represented by a specific structural formula (1); Group B of at least one of structures each represented by a specific structural formula (2) or structures each represented by a structural formula (3); and Group C of structures each represented by a specific structural formula (4). The surface layer has a volume resistivity of 1.0&#xd7;10&#x3a9;&#xb7;cm or more and 1.0&#xd7;10&#x3a9;&#xb7;cm or less, and the surface layer has a universal hardness at a depth 1 &#x3bc;m from the surface thereof of 1.0 N/mmor more and 7.0 N/mmor less.

Electroconductive member for electrophotography, process cartridge, and electrophotographic image-forming apparatus

An electrophotographic charging member in which the adhesion of contamination is more suppressed is provided. The electrophotographic charging member includes an electro-conductive support and an electro-conductive elastic layer on the electro-conductive support, the electro-conductive elastic layer includes 10% by mass or more and 50% by mass or less of an aggregate of crosslinked rubber particles, the aggregate of the crosslinked rubber particles has a circle-equivalent diameter of 10 &#x3bc;m or more and 50 &#x3bc;m or less, the crosslinked rubber particles have one of an acrylic resin and a styrene acrylic resin chemically bonded to a surface thereof, the charging member has a protrusion derived from the aggregate of the crosslinked rubber particles on a surface thereof, and the protrusion has an average height of 50 nm or more and 200 nm or less.

Charging member, process cartridge and electrophotographic image forming apparatus

Provided is a method of producing a member for electrophotography capable of providing a high-quality electrophotographic image. The method of producing a member for electrophotography is a method of producing a member for electrophotography having an electro-conductive support, an elastic layer, and a surface layer, the method comprising: a first step of forming, on a surface of the elastic layer, a coat of a surface-layer coating liquid containing a hydrolyzed condensate of a hydrolyzable silane compound and a chelate titanium compound represented by the following general formula (2); and a second step of crosslinking the hydrolyzed condensate in the coat through cleavage of an epoxy group in the hydrolyzed condensate to form the surface layer: 

Method of producing member for electrophotography

Provided is an electroconductive member for electrophotography which is suppressed in adhesion of a contaminant to a surface thereof. The electroconductive member for electrophotography includes, in this order, an electroconductive support, an electroconductive elastic layer, and a surface layer. The surface layer contains a binder resin and electroconductive fine particles having a number average particle diameter of 5.0 nm or more and 50.0 nm or less. At least part of the electroconductive fine particles are exposed from the surface layer. The surface layer has, on a surface thereof, protruded portions derived from exposed portions of the electroconductive fine particles. The surface layer has a volume resistivity of 1.0&#xd7;10&#x3a9;cm or more and 1.0&#xd7;10&#x3a9;cm or less and a universal hardness at a depth of 1 &#x3bc;m from the surface thereof of 1.0 N/mmor more and 7.0 N/mmor less.

A member for electrophotography for use in forming a high quality electrophotographic image for a long period is provided. The member for electrophotography includes a support, an elastic layer on the support, and a surface layer on the elastic layer. The elastic layer includes a quaternary ammonium salt and an epichlorohydrin rubber. The surface layer includes a material having a specific structure. A universal hardness a surface of the surface layer is 1.0 N/mmor more and 5.0 N/mmor less.

Member for electrophotography, method for producing the same, and image forming apparatus

It is intended to provide a member for electrophotography that can inhibit the adhesion of dirt to the outer surface. The member for electrophotography has a substrate, an elastic layer on the substrate, and a surface layer on the elastic layer. The surface layer contains a binder resin and first particles, the surface of the surface layer has first convexes derived from the first particles, the first particles resulting in the first convex has an average inter-particle surface distance of 50 nm or less, the first particles have a number-average particle diameter of 200 nm or more and 1000 nm or less, and the surface of the surface layer has a universal hardness of 1.0 N/mmor more and 7.0 N/mmor less.

Member for electrophotography, process cartridge and image forming apparatus

There is provided a charging member having charging performance that is not easily changed even by long-term use. The charging member includes an electro-conductive support, an elastic layer, and a surface layer. The elastic layer contains particles in such a manner that at least a part of the particles are exposed from the elastic layer, and thus a surface of the elastic layer is roughened. The particles are high-molecular-weight polyethylene particles. The surface of the elastic layer is covered with the surface layer in such a manner that the surface shape of the elastic layer is reflected in the surface shape of the charging member. The surface layer contains a high-molecular compound having a specific constitutional unit.

Charging member and electrophotographic apparatus

Provided a charging member which can prevent any contaminants deposited on a cleaning member from adhering thereto by making low a surface free energy and coefficient of friction thereof. The charging member has a substrate, an elastic layer and a surface layer, and the surface layer contains a polymer having an Si&#x2014;O&#x2014;W linkage; the polymer having a constitutional unit represented by the following formula (1) and a constitutional unit represented by the following formula (2): 

Charging member, process for its production, process cartridge and electrophotographic apparatus

Provided are the following charging member and a method of producing the charging member. The charging member has an improved charging ability and hence alleviates, in particular, a positive ghost. The charging member can maintain resistance to the adhesion of toner, a toner external additive, or the like over a long time period. The charging member for an electrophotographic apparatus comprises an electro-conductive support, an electro-conductive elastic layer, and a surface layer, wherein the surface layer comprises a polymer compound having an Si&#x2014;O&#x2014;Ti linkage in a molecular structure thereof, and the polymer compound has each of constitutional units represented by a formula (1), a formula (2), and a formula (3) defined in the description. The method is a method of producing the charging member.

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Tokyo, Japan

Hiroki Masu