# US 2013/0252152 A1 · Electrophotographic photoreceptor, image forming apparatus, and process cartridge > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0252152 A1 - Document ID: US20130252152A1 - Status: Published application - Kind: A1 - Application number: 13/630,854 - Filed: 2012-09-28 - Published: 2013-09-26 - Earliest claimed: 2012-03-26 - Assignees: Fuji Xerox Co., Ltd. - Applicants: Fuji Xerox Co., Ltd. - Inventors: Yukimi KAWABATA - Web page: https://patentgrep.com/patent/US20130252152A1 ## CPC - G03G 5/14726: {Halogenated polymers} - G03G 5/047: characterised by the charge-generation layers or charge transport layers {(G03G5/0433 and G03G5/0436 take precedence)} - G03G 5/0539: {Halogenated polymers} - G03G 5/14708: {comprising organic material} - G03G 5/14713: {Macromolecular material} - G03G 15/00: Apparatus for electrographic processes using a charge pattern (G03G16/00, G03G17/00 take precedence) - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An electrophotographic photoreceptor includes a substrate and a photosensitive layer, wherein the electrophotographic photoreceptor has a surface layer containing fluorine resin particles, and the fluorine resin particles exposed on a surface satisfy the following Expression (1): 0.5≦(A)/(B)≦−10 Expression (1) wherein, (A) represents a number of aggregated particles in which 5 to 20 fluorine resin particles are connected and aggregated, and (B) represents a total number of fluorine resin particles that are isolated without being aggregated and aggregated particles in which 2 to 4 fluorine resin particles are connected and aggregated. ## Claims ### Claim 1 An electrophotographic photoreceptor comprising: a substrate; and a photosensitive layer, wherein the electrophotographic photoreceptor has a surface layer containing fluorine resin particles, and the fluorine resin particles exposed on a surface satisfy the following Expression (1): 0.5≦(A)/(B)≦10 Expression (1) wherein, (A) represents a number of aggregated particles in which 5 to 20 fluorine resin particles are connected and aggregated, and (B) represents a total number of fluorine resin particles that are isolated without being aggregated and aggregated particles in which 2 to 4 fluorine resin particles are connected and aggregated. ### Claim 2 (depends on 1) The electrophotographic photoreceptor according to claim 1, wherein the fluorine resin particles contained in a part of 0.2 μm to 5 μm inside the surface of the surface layer satisfy the following Expression (2): 0.1≦(C)/(D)≦3 Expression (2) wherein, (C) represents a number of aggregated particles in which 2 to 5 fluorine resin particles are connected and aggregated, and (D) represents a number of fluorine resin particles that are isolated without being aggregated. ### Claim 3 (depends on 1) The electrophotographic photoreceptor according to claim 1, wherein in the fluorine resin particles exposed on the surface, a number of aggregated particles in which 21 or more fluorine resin particles are connected and aggregated is 5 or less. ### Claim 4 (depends on 1) The electrophotographic photoreceptor according to claim 1, wherein the fluorine resin particles contained in a part of 0.2 μm to 5 μm inside the surface of the surface layer include 5 or less aggregated particles in which 6 or more fluorine resin particles are connected and aggregated. ### Claim 5 (depends on 1) The electrophotographic photoreceptor according to claim 1, wherein the (A)/(B) is from 2 to 10. ### Claim 6 (depends on 2) The electrophotographic photoreceptor according to claim 2, wherein the (C)/(D) is from 0.2 to 3. ### Claim 7 (depends on 1) The electrophotographic photoreceptor according to claim 1, wherein a content of the fluorine resin particles is from 1% by weight to 15% by weight with respect to the surface layer. ### Claim 8 (depends on 1) The electrophotographic photoreceptor according to claim 1, wherein an average primary particle diameter of the fluorine resin particles is from 0.05 μm to 1 μm. ### Claim 9 (depends on 1) The electrophotographic photoreceptor according to claim 1, wherein the fluorine resin particles are selected from a tetrafluoroethylene resin, a trifluoroethylene chloride resin, a hexafluoropropylene resin, a vinyl fluoride resin, a vinylidene fluoride resin, and a difluorodichloroethylene resin. ### Claim 10 (depends on 1) The electrophotographic photoreceptor according to claim 1, wherein a fluorinated alkyl group-containing copolymer is further contained. ### Claim 11 (depends on 1) An image forming apparatus comprising: an electrophotographic photoreceptor; a charging unit that charges a surface of the electrophotographic photoreceptor; a latent image forming unit that forms an electrostatic latent image on a charged surface of the electrophotographic photoreceptor; a developing unit that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with a toner to form a toner image; and a transfer unit that transfers the toner image formed on the surface of the electrophotographic photoreceptor onto a recording medium, wherein the electrophotographic photoreceptor is the electrophotographic photoreceptor according to claim 1. ### Claim 12 (depends on 11) The image forming apparatus according to claim 11, wherein in the electrophotographic photoreceptor, the fluorine resin particles contained in a part of 0.2 μm to 5 μm inside the surface of the surface layer satisfy the following Expression (2): 0.1≦(C)/(D)≦3 Expression (2) wherein, (C) represents a number of aggregated particles in which 2 to 5 fluorine resin particles are connected and aggregated, and (D) represents a number of fluorine resin particles that are isolated without being aggregated. ### Claim 13 (depends on 11) The image forming apparatus according to claim 11, wherein in the electrophotographic photoreceptor, a number of aggregated particles in which 21 or more fluorine resin particles are connected and aggregated is 5 or less in the fluorine resin particles exposed on the surface. ### Claim 14 (depends on 11) The image forming apparatus according to claim 11, wherein in the photoreceptor, the fluorine resin particles contained in the part that is deeper 0.2 μm to 5 μm inside the surface of the surface layer include 5 or less aggregated particles in which 6 or more fluorine resin particles are connected and aggregated. ### Claim 15 (depends on 1) A process cartridge comprising: an electrophotographic photoreceptor; and at least one selected from A) a charging unit that charges a surface of the electrophotographic photoreceptor, B) a latent image forming unit that forms an electrostatic latent image on a charged surface of the electrophotographic photoreceptor, C) a developing unit that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with a toner to form a toner image, D) a transfer unit that transfers the toner image formed on the surface of the electrophotographic photoreceptor onto a recording medium, and E) a cleaning unit that cleans the electrophotographic photoreceptor, wherein the electrophotographic photoreceptor is the electrophotographic photoreceptor according to claim 1. ### Claim 16 (depends on 15) The process cartridge according to claim 15, wherein in the electrophotographic photoreceptor, the fluorine resin particles contained in a part of 0.2 μm to 5 μm inside the surface of the surface layer satisfy the following Expression (2): 0.1<(C)/(D)<3 Expression (2) wherein, (C) represents a number of aggregated particles in which 2 to 5 fluorine resin particles are connected and aggregated, and (D) represents a number of fluorine resin particles that are isolated without being aggregated. ### Claim 17 (depends on 15) The process cartridge according to claim 15, wherein in the electrophotographic photoreceptor, a number of aggregated particles in which 21 or more fluorine resin particles are connected and aggregated is 5 or less in the fluorine resin particles exposed on the surface. ### Claim 18 (depends on 15) The process cartridge according to claim 15, wherein in the photoreceptor, the fluorine resin particles contained in the part 0.2 μm to 5 μm inside the surface of the surface layer include 5 or less aggregated particles in which 6 or more fluorine resin particles are connected and aggregated.