# US 8,465,897 B2 · Electrophotographic toner > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,897 B2 - Document ID: US8465897B2 - Status: Granted - Kind: B2 - Application number: 13/097,226 - Filed: 2011-04-29 - Published: 2011-09-01 - Granted: 2013-06-18 - Earliest claimed: 2009-11-23 - Assignees: Toshiba Tec Kabushiki Kaisha - Applicants: Takayasu Aoki; Yasuhito Noda; Koji Imamiya; Tsuyoshi Itou; Noboru Furuyama - Inventors: Takayasu Aoki; Yasuhito Noda; Koji Imamiya; Tsuyoshi Itou; Noboru Furuyama - Web page: https://patentgrep.com/patent/US8465897B2 ## CPC - G03G 9/0926: {characterised by physical or chemical properties} - G03G 9/08755: {Polyesters} - G03G 9/08793: {Crosslinked polymers} - G03G 9/08795: {characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants} - G03G 9/08797: {characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature} - G03G 9/0928: {Compounds capable to generate colouring agents by chemical reaction} - G03G 9/09708: {Inorganic compounds} - G03G 9/09725: {Silicon-oxides; Silicates} - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An electrophotographic toner, which is decolorized by heating and a glossiness after decolorization of which is less than 10, comprising an electron donating color former compound, an electron accepting color developing agent, and a polyester binder resin. ## Claims ### Claim 1 An electrophotographic toner, which is decolorized by heating and a glossiness after decolorization of which is less than 10, comprising an electron donating color former compound, an electron accepting color developing agent, and a polyester binder resin. ### Claim 2 (depends on 1) The toner according to claim 1, wherein a weight average molecular weight Mw of the polyester binder resin is 6000 or more and 25000 or less. ### Claim 3 (depends on 1) The toner according to claim 1, wherein the toner has a glass transition point of 35° C. or higher and 65° C. or lower. ### Claim 4 (depends on 1) The toner according to claim 1, wherein the toner has a softening point of 80° C. or higher and 120° C. or lower. ### Claim 5 (depends on 1) The toner according to claim 1, wherein the toner has a toluene insoluble content of 10% by mass or more and 40% by mass or less. ### Claim 6 (depends on 1) The toner according to claim 1, wherein the toner has an acid value of 25 mgKOH/g or less. ### Claim 7 (depends on 1) The toner according to claim 1, further comprising a temperature control agent. ### Claim 8 (depends on 7) The toner according to claim 7, wherein at least the electron donating color former compound, the electron accepting color developing agent, and the temperature control agent are microencapsulated. ### Claim 9 (depends on 1) The toner according to claim 1, wherein the toner is decolorized at a temperature higher than the fixing temperature of the toner. ### Claim 10 (depends on 1) The toner according to claim 1, further comprising at least one type of fine particles having an average primary particle diameter of 50 nm or more and 200 nm or less, wherein the coverage of toner particles of the toner with the fine particles having an average primary particle diameter of 50 nm or more and 200 nm or less is 30% or less per fine particles of one kind of substance, and the coverage of the toner particles with all of the fine particles is 50% or more and 150% or less. ### Claim 11 (depends on 10) The toner according to claim 10, wherein the fine particles comprise any of silica, titania, alumina, strontium titanate, and tin oxide. ### Claim 12 (depends on 1) The toner according to claim 1, wherein the electron donating color former compound is a leuco dye. ### Claim 13 (depends on 1) The toner according to claim 1, wherein the polyester binder resin is a polyester resin obtained by polycondensation of a carboxylic acid component and an alcohol component and has a crosslinked structure formed of a crosslinking component including at least either one of a trivalent or higher valent carboxylic acid and a trihydric or higher hydric alcohol. ### Claim 14 (depends on 13) The toner according to claim 13, wherein the crosslinking component is trimellitic acid. ### Claim 15 (depends on 14) The toner according to claim 14, wherein the crosslinking component is contained in the binder resin in an amount of from 3 to 15 wt %. ### Claim 16 (depends on 1) A toner cartridge containing the electrophotographic toner according to claim 1. ### Claim 17 (depends on 1) An image forming apparatus comprising the electrophotographic toner according to claim 1. ### Claim 18 An electrophotographic toner, which is decolorizable with heat and a glossiness of which at decolorized state is less than 10, comprising an electron donating color former compound, an electron accepting color developing agent, and a polyester binder resin. ### Claim 19 (depends on 18) The toner according to claim 18, further comprising a temperature control agent. ### Claim 20 (depends on 19) The toner according to claim 19, wherein at least the electron donating color former compound, the electron accepting color developing agent, and the temperature control agent are microencapsulated. ### Claim 21 (depends on 18) The toner according to claim 18, wherein the toner is decolorized with heat which make the temperature control agent heated to a temperature not lower than the melting point of the temperature control agent. ### Claim 22 (depends on 18) A toner cartridge containing the electrophotographic toner according to claim 18. ### Claim 23 (depends on 18) An image forming apparatus comprising the electrophotographic toner according to claim 18.