Canon Kabushiki Kaisha

Shohei Urushihara

Masaki Yamada

Minoru Nakamura

Kunimasa Kawamura

Takashi Koyanagi

Hideya Arimura

Sosuke Yamaguchi

Takashi Kusaba

Ryo Sugiyama

Kentarou Nakamura

Yuji Sakurai

Kazuaki Nagaoka

Minoru Ito

Takahiro Miyazawa

Yasushi Katsuta

Masashi Uno

Provided an electrophotographic member capable of causing less fog in an H/H environment even when used in a torque-reduced image forming apparatus. The member comprises an electro-conductive substrate, an electro-conductive layer thereon and insulating parts, the member having a surface having an electrical insulating first region and an electro-conductive second region, the first region and the second region being adjacent to each other, a total area of the second region in a square region put on an outer surface of the member is 30% to 80% of an area of the square region; two or more of the 200 straight lines drawn in the square region at an interval of 5 &#x3bc;m pass the second region at least once, and, the number of line segment LS having a length of 200 &#x3bc;m or more is 5% or less of the total number of the line segment LS.

Electrophotographic member, electrophotographic process cartridge and electrophotographic image forming apparatus

Provided is a developer carrying member that enables stable formation of images of high quality even on recording paper having a high talc content. The developer carrying member includes a conductive base member and a surface layer, wherein the surface layer includes a urethane resin, and the urethane resin has a carbonate bond and a tertiary amine structure.

Developer carrying member, process cartridge, and electrophotographic apparatus

The developer carrying member, includes: an electroconductive substrate; and a surface layer containing a resin, on the substrate, in which a thickness of the surface layer is 1.0 &#x3bc;m or more and 100.0 &#x3bc;m or less, a Martens hardness at an indentation depth of 0.1 &#x3bc;m that is measured by infiltrating a Vickers indenter in a thickness direction of the surface layer from an outer surface of the surface layer is 50.0 N/mmor more and 100.0 N/mmor less, an Asker C hardness that is measured from the outer surface of the surface layer is 75&#xb0; or more and 90&#xb0; or less, and a value of a work function of the outer surface of the surface layer is 5.6 eV or more and 6.0 eV or less.

The electrophotographic member comprises: an electroconductive substrate; and an electroconductive layer on or above the substrate, an outer surface of the electrophotographic member having electrically insulating first regions and an electroconductive second region, each of the first regions being adjacent to the second region, wherein assuming that a square region having a side length of 300 &#x3bc;m is put on an outer surface of the electrophotographic member, in the square regions, the first regions are included, and assuming that Voronoi tessellation is conducted with respect to the first regions in the square region to create Voronoi polygons, a coefficient of variation of S/SV is from 0.10 to 1.00, where SV denotes a plane area of each of the Voronoi polygons, and Sdenotes a plane area of one of the first regions included in each of the Voronoi polygons.

Provided is an electrophotographic member including an electro-conductive substrate and a surface layer on the substrate. The surface layer contains a urethane resin and a first polymer having a specific nitrogen-containing structure. The urethane resin has a structure derived from a second polymer containing a fluorine atom or a structure derived from a third polymer containing a fluorine atom and a silicon atom. The surface layer contains nitrogen atoms derived from the nitrogen-containing structure at a specific ratio in a region from the outer surface of the surface layer to a depth of 300 nm, and the atomic ratios of nitrogen atoms, fluorine atoms, and silicon atoms in a region from a depth of 100 nm from the outer surface of the surface layer to a depth of 300 nm and a region from the outer surface to a depth of 10 nm have specific relationships.

Electrophotographic member, process cartridge, and electrophotographic apparatus

The present invention provides an electrophotographic member which has a high ability to impart charge to toners while the charge imparting ability is unlikely to be reduced even under an environment at high temperature and high humidity. The electrophotographic member comprises a substrate, an elastic layer formed on the substrate, an intermediate layer covering the surface of the elastic layer, and a surface layer covering the surface of the intermediate layer, wherein the intermediate layer contains a binder resin and a polymer having a specific structure, the surface layer contains silicon oxide, and the surface layer has a thickness of 10 nm or more and 300 nm or less.

Electrophotographic member, process cartridge and electrophotographic image forming apparatus

A member for electrophotography has an electro-conductive base and at least one electro-conductive resin layer, in which the electro-conductive resin layer of the outermost layer contains urethane resin and the urethane resin has a structure of a silicone graft fluororesin and a structure represented by Formula (1) 

Member for electrophotography, process cartridge, and electrophotographic apparatus

Provided is an electrophotographic member that is excellent in charge-imparting performance for a toner, and that hardly causes tackiness on its surface even when placed under a high-temperature and high-humidity environment over a long time period. The electrophotographic member includes a substrate and a surface layer, in which the surface layer satisfies the following requirements (A) and (B): (A) the surface layer contains, in a region from its surface to a depth of up to 0.1 &#x3bc;m, a copolymer containing a constituent unit represented by the following structural formula (1), and at least one selected from the group consisting of a constituent unit represented by the following structural formula (2) and a constituent unit represented by the following structural formula (3); and (B) the concentration of a nitrogen atom derived from a nitrogen-containing aromatic heterocyclic amine structure in the copolymer is from 6.0 mass % to 30.0 mass %. 

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

The electrophotographic member includes an electroconductive substrate and an electroconductive surface layer. The surface layer contains an electroconductivity imparting agent and a polyrotaxane including a first and a second polyrotaxane molecule. The first polyrotaxane molecule includes a first cyclic molecule, and the second polyrotaxane molecule includes a second cyclic molecule. The cyclic molecules of the first and the second polyrotaxane molecules are bound in such a manner that the oxygen atom of a hydroxy group of the first cyclic molecule and the oxygen atom of a hydroxy group of the second cyclic molecule are bound with a structure represented by the following formula (1):*&#x2014;R&#x2014;Z&#x2014;R&#x2014;** In this formula, z represents a linking group, and '*' and '**' represent binding sites to be bound to either of the oxygen atoms derived from the hydroxy groups of the first and the second cyclic molecule. Rand Reach represent a specific structure.

Provided are a developing unit alleviating fogging occurrence and an electrophotographic image forming apparatus providing images over long periods. The developing unit includes at least a toner of () and a developing roller of (). () When a displacement amount when a load is applied at Y&#xb0; C. and 9.8&#xd7;10N/sec to 2.94&#xd7;10N is X, a displacement amount when the toner is left to stand for 0.1 second is X, a displacement amount when the load is reduced at 9.8&#xd7;10N/sec to 0N is X, and percentage of (X&#x2212;X) to Xis Z(Y), 40&#x2266;Z(25)&#x2266;80 and 10&#x2266;Z(50)&#x2266;55 are satisfied; when a gradient from the origin to the maximum load in the load-displacement curve at 25&#xb0; C. is R(25), 0.49&#xd7;10&#x2266;R(25)&#x2266;1.70&#xd7;10is satisfied; the toner has glass transition temperature TgA (40&#xb0; C.-60&#xb0; C.) and maximum endothermic peak temperature P1 (70&#xb0; C.-110&#xb0; C.), 15&#xb0; C.&#x2266;(P1&#x2212;TgA)&#x2266;70&#xb0; C. is satisfied. () The developing roller includes a surface layer containing a urethane resin having structure (a), and one or both structures (b)-(c). 

Developing unit and electrophotographic image forming apparatus

A high-quality developing member which excels in filming resistance and excels in leak resistance despite high electroconductivity is provided. The developing member includes an electroconductive substrate, an elastic layer formed on the substrate, and a surface layer which covers a surface of the elastic layer. The surface layer includes a first resin which has, between two adjacent urethane linkages, a structure represented by the structural formula (1) and one or both of structures selected from the group consisting of a structure represented by the structural formula (2) and a structure represented by the structural formula (3), a second resin which has a structure represented by the structural formula (4) and one or both of structures selected from the group consisting of a structure represented by the structural formula (5) and a structure represented by the structural formula (6), and an electronically conductive filler.

Developing member, process cartridge, and electrophotographic apparatus

A developing roller includes: a mandrel; an elastic layer provided for an outer periphery of the mandrel, the elastic layer including an addition-curing silicone rubber; and a surface layer provided for an outer periphery of the elastic layer, in which: the elastic layer includes a compound represented by the following formula (1); when the content of such a compound that n in the formula (1) represents an integer of 3 to 12 in the elastic layer is represented by P1, and the content of such a compound that n in the formula (1) represents an integer of 13 to 20 in the elastic layer is represented by P2, P1+P2 is 5,000 ppm by mass to 12,000 ppm by mass; and P1 is 1,500 ppm by mass to 6,000 ppm by mass (In the formula (1), n represents an integer of 3 to 20): 

Developing member including elastic member containing cured product of addition-curing silicone rubber mixture, processing cartridge including the developing member, and electrophotographic apparatus including the developing member

Provided is a developing roller including elastic layer and resin layer adhered to each other and having an appropriately resistance, thereby suppressing fogging. The developing member comprises a mandrel; an elastic layer; and a resin layer, wherein: the resin layer comprises polyurethane resin obtained by isocyanate and polyol; and the elastic layer includes cured silicone rubber composition comprising (a)-(d): 

Developing member

Provided is a developing member capable of suppressing a variation in resistance even when exposed to a high-temperature, high-humidity environment for a long time period. The developing member comprises: a mandrel; an electro-conductive elastic layer provided on a periphery of the mandrel; and a surface layer provided on a surface of the elastic layer, wherein: the elastic layer contains a dimethyl silicone rubber and carbon black; and an amount &#x3b1; of a hydrogen atom bound to a silicon atom of the dimethyl silicone rubber, and an amount &#x3b2; of a hydrogen atom of methyl groups bound to a silicon atom of the dimethyl silicone rubber, satisfy a relationship of 2.5&#xd7;10&#x2266;&#x3b1;/&#x3b2;&#x2266;1.0&#xd7;10.

Developing member, process cartridge, and electrophotographic image forming apparatus

There is provided a process for producing a regenerated elastic roller which can be again used for the formation of high-quality electrophotographic images by sufficiently relaxing a compression set of the elastic roller having the compression set caused in an elastic layer in usage. The process for producing a regenerated elastic roller includes a step of heating an elastic roller having a conductive mandrel and an elastic layer and having a compression set caused in the elastic layer, in a cylindrical mold to thermally expand the elastic layer and to cause a surface of the elastic roller to contact an inner wall of the cylindrical mold.

Growing community of inventors

Suntou-gun, Japan

Shohei Urushihara