# US 8,785,094 B2 · Electrostatic latent image developing toner, electrostatic latent image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,094 B2 - Document ID: US8785094B2 - Status: Granted - Kind: B2 - Application number: 13/564,256 - Filed: 2012-08-01 - Published: 2013-09-19 - Granted: 2014-07-22 - Earliest claimed: 2012-03-13 - Assignees: Fuji Xerox Co., Ltd. - Applicants: Shuji Sato; Atsushi Sugitate; Masaru Takahashi; Shotaro Takahashi - Inventors: Shuji Sato; Atsushi Sugitate; Masaru Takahashi; Shotaro Takahashi - Web page: https://patentgrep.com/patent/US8785094B2 ## CPC - G03G 9/09716: {treated with organic compounds} - G03G 9/0819: {characterised by the dimensions of the particles} - G03G 9/0821: {characterised by physical parameters (magnetic parameters G03G9/083)} - G03G 9/0825: {characterised by their structure; characterised by non-homogenuous distribution of components (microcapsular toners G03G9/093)} - G03G 9/09725: {Silicon-oxides; Silicates} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An electrostatic latent image developing toner contains toner particles that contain a binder resin and a pigment; and an external additive that contains inorganic particles, a ratio (C/D) of an average maximum thickness C to an average equivalent circle diameter D in the toner particles is from 0.05 to 0.7, the inorganic particles include silicone oil-treated inorganic particles in which the amount of free silicone oil with respect to the inorganic particles is from 0.1% by weight to 10% by weight, and the amount of the silicone oil-treated inorganic particles added with respect to 100 parts by weight of the toner particles is from 0.1 part by weight to 10 parts by weight. ## Claims ### Claim 1 An electrostatic latent image developing toner comprising: toner particles that contain a binder resin and a pigment; and an external additive that contains inorganic particles, wherein a ratio (C/D) of an average maximum thickness C of the toner particles to an average equivalent circle diameter D in the toner particles is from 0.05 to 0.7, the inorganic particles include silicone oil-treated inorganic particles in which the amount of free silicone oil with respect to the inorganic particles is from 0.1% by weight to 10% by weight, and the amount of the silicone oil-treated inorganic particles added with respect to 100 parts by weight of the toner particles is from 0.1 part by weight to 10 parts by weight. ### Claim 2 (depends on 1) The electrostatic latent image developing toner according to claim 1, wherein the electrostatic latent image developing toner satisfies the following formula: 0.1≦C/D≦0.6. ### Claim 3 (depends on 1) The electrostatic latent image developing toner according to claim 1, wherein the pigment has a flake-like shape. ### Claim 4 (depends on 1) The electrostatic latent image developing toner according to claim 1, wherein the number of pigment particles in which an angle between a long-axis direction of the toner and a long-axis direction of the pigment particles is from −30° to +30° is 60% or greater of all observed pigment particles, which are measured using a cross-section of the toner in a thickness direction. ### Claim 5 (depends on 1) The electrostatic latent image developing toner according to claim 1, wherein the number of pigment particles in which an angle between a long-axis direction of the toner and a long-axis direction of the pigment particles is from −30° to +30° is from 70% to 95% of all observed pigment particles, which are measured using a cross-section of the toner in a thickness direction. ### Claim 6 (depends on 1) The electrostatic latent image developing toner according to claim 1, wherein the electrostatic latent image developing toner satisfies the following formula: 2≦A/B≦100, wherein A is reflectance at an acceptance angle of +30° that is measured when a solid image is formed with the electrostatic latent image developing toner and the image is irradiated with incident light at an incidence angle of −45° by the use of a variable-angle photometer, and B is reflectance at an acceptance angle of −30° that is measured when the image is irradiated with incident light at an incidence angle of −45° by the use of a variable-angle photometer. ### Claim 7 (depends on 6) The electrostatic latent image developing toner according to claim 6, wherein the electrostatic latent image developing toner satisfies the following formula: 20≦A/B≦90. ### Claim 8 (depends on 1) The electrostatic latent image developing toner according to claim 1, wherein the amount of silicone oil for treating the inorganic particles is from 1.0% by weight to 30% by weight. ### Claim 9 (depends on 1) An electrostatic latent image developer comprising: the electrostatic latent image developing toner according to claim 1. ### Claim 10 (depends on 9) The electrostatic latent image developer according to claim 9, wherein the electrostatic latent image developing toner satisfies the following formula: 0.1≦C/D≦0.6. ### Claim 11 (depends on 9) A process cartridge for an image forming apparatus comprising: an image holding member; and a developing section that develops an electrostatic latent image formed on a surface of the image holding member using a developer to form a toner image, wherein the developer is the electrostatic latent image developer according to claim 9. ### Claim 12 (depends on 11) The process cartridge for an image forming apparatus according to claim 11, wherein the electrostatic latent image developing toner satisfies the following formula: 0.1≦C/D≦0.6. ### Claim 13 (depends on 1) A toner cartridge comprising: a toner accommodation chamber, wherein the toner accommodation chamber contains the electrostatic latent image developing toner according to claim 1. ### Claim 14 (depends on 13) The toner cartridge according to claim 13, wherein the electrostatic latent image developing toner satisfies the following formula: 0.1≦C/D≦0.6. ### Claim 15 (depends on 1) An image forming apparatus comprising: an image holding member; a charging device that charges a surface of the image holding member; a latent image forming device that forms an electrostatic latent image on a charged surface of the image holding member; a developing device that develops the electrostatic latent image as a toner image with the electrostatic latent image developing toner according to claim 1; a transfer device that transfers the toner image formed on the surface of the image holding member onto a recording medium; a fixing device that fixes the toner image transferred onto the recording medium; and a cleaning device that has a cleaning blade that is brought into contact with the surface of the image holding member to clean the surface. ### Claim 16 (depends on 15) The image forming apparatus according to claim 15, wherein the electrostatic latent image developing toner satisfies the following formula: 0.1≦C/D≦0.6. ### Claim 17 (depends on 1) An image forming method comprising: charging a surface of an image holding member; forming an electrostatic latent image on the surface of the image holding member; developing the electrostatic latent image with the electrostatic latent image developing toner according to claim 1 to form a toner image; transferring the developed toner image onto a recording medium; fixing the toner image transferred onto the recording medium; and cleaning with a cleaning blade that is brought into contact with the surface of the image holding member to clean the surface. ### Claim 18 (depends on 17) The image forming method according to claim 17, wherein the electrostatic latent image developing toner satisfies the following formula: 0.1≦C/D≦0.6. ### Claim 19 (depends on 1) The electrostatic latent image developing toner according to claim 1, wherein the silicone oil is selected from the group consisting of a dimethyl silicone oil, an alkyl-modified silicone oil, an amino-modified silicone oil, a carboxylic acid-modified silicone oil, an epoxy-modified silicone oil, a fluorine-modified silicone oil, an alcohol-modified silicone oil, a polyether-modified silicon oil, a methylphenyl silicone oil, a methyl hydrogen silicone oil, a mercapto-modified silicone oil, a higher fatty acid-modified silicone oil, a phenol-modified silicone oil, a methacrylic acid-modified silicone oil, and a methylstyryl-modified silicone oil.