Patents by Inventor Taiji Katsura
Taiji Katsura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11169460Abstract: A toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the organosilicon polymer has a structure represented by at least one selected from the group consisting of RaSiO3/2 and Rb2SiO2/2 (wherein Ra and Rb represent organic groups), and in the number particle size distribution of the toner as measured within a particle size range of from 2 to 60 ?m, the number-average particle diameter T-D50n at which the accumulation from the smallest diameter is 50% is from 6 to 12 ?m, the number ratio of toner 4 ?m or less in size is from 2% to 5% of the total toner, and the number ratio of toner 3 ?m or less in size as a percentage of the total toner 4 ?m or less in size is from 25% to 50%.Type: GrantFiled: December 27, 2019Date of Patent: November 9, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
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Patent number: 11003104Abstract: Provided is a toner including a toner particle and an external additive, wherein the external additive includes a composite particle including a hydrotalcite particle covered on the surface with an organosilicon polymer fine particle, a coverage ratio of the hydrotalcite particle surface by the organosilicon polymer fine particle is from 1% to 50%, and given A (nm) as the number-average particle diameter of the primary particles of the organosilicon polymer fine particle and B (nm) as the number-average particle diameter of the primary particles of the hydrotalcite particle, the toner satisfies the following formula (I) and formula (II): A<B??(I) 20?A?350??(II).Type: GrantFiled: December 27, 2019Date of Patent: May 11, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka
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Patent number: 11003105Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the external additive contains composite particles of an organosilicon polymer fine particle and a fatty acid metal salt.Type: GrantFiled: December 27, 2019Date of Patent: May 11, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura
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Patent number: 10976679Abstract: A toner containing: a toner particle that contains a binder resin and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the binder resin contains an amorphous resin and a crystalline polyester resin, a content of the crystalline polyester resin in the binder resin is from 5 to 30 mass %, and the crystalline polyester resin contains from 5 to 25 mass % of a component having a molecular weight of not more than 2,500.Type: GrantFiled: December 27, 2019Date of Patent: April 13, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga
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Patent number: 10942466Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the toner particle contains a polyvalent metal compound, the polyvalent metal compound is at least one selected from the group consisting of aluminum compounds, iron compounds and magnesium compounds, a content of a metal element derived from the polyvalent metal compound in the toner particle is from 0.080 to 20.000 ?mol/g, the external additive contains an organosilicon polymer particle having a hydroxyl group, a ratio of a number-average particle diameter of the organosilicon polymer particle to a number-average particle diameter of the toner particle is from 0.0160 to 0.0650, and a content of the organosilicon polymer particle is at least 0.10 mass parts per 100.00 mass parts of the toner particle.Type: GrantFiled: December 27, 2019Date of Patent: March 9, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki
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Publication number: 20210003932Abstract: A toner including a toner particle including a binder resin, wherein fine particles A and B are present on a surface of the toner particle; the fine particles A are a fatty acid metal salt; the fine particles B have a specific volume resistivity; an average theoretical surface area of the toner particle, an amount of the fine particles A, and a coverage ratio of the toner particle surface by the fine particles A satisfy a specific relationship; the amount of the fine particles B is in a specific range; and a proportion F of an area occupied by a part of the fine particles B embedded in a surface vicinity region of the toner in a total area occupied by the fine particles B present in a cross section of one particle of the toner is 50% by area or more.Type: ApplicationFiled: June 25, 2020Publication date: January 7, 2021Inventors: Shohei Tsuda, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
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Publication number: 20200209773Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the toner particle contains a polyvalent metal compound, the polyvalent metal compound is at least one selected from the group consisting of aluminum compounds, iron compounds and magnesium compounds, a content of a metal element derived from the polyvalent metal compound in the toner particle is from 0.080 to 20.000 ?mol/g, the external additive contains an organosilicon polymer particle having a hydroxyl group, a ratio of a number-average particle diameter of the organosilicon polymer particle to a number-average particle diameter of the toner particle is from 0.0160 to 0.0650, and a content of the organosilicon polymer particle is at least 0.10 mass parts per 100.00 mass parts of the toner particle.Type: ApplicationFiled: December 27, 2019Publication date: July 2, 2020Inventors: Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki
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Publication number: 20200209776Abstract: A toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the organosilicon polymer has a structure represented by at least one selected from the group consisting of RaSiO3/2 and Rb2SiO2/2 (wherein Ra and Rb represent organic groups), and in the number particle size distribution of the toner as measured within a particle size range of from 2 to 60 ?m, the number-average particle diameter T-D50n at which the accumulation from the smallest diameter is 50% is from 6 to 12 ?m, the number ratio of toner 4 ?m or less in size is from 2% to 5% of the total toner, and the number ratio of toner 3 ?m or less in size as a percentage of the total toner 4 ?m or less in size is from 25% to 50%.Type: ApplicationFiled: December 27, 2019Publication date: July 2, 2020Inventors: Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura, Masamichi Sato
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Publication number: 20200209774Abstract: Provided is a toner including a toner particle and an external additive, wherein the external additive includes a composite particle including a hydrotalcite particle covered on the surface with an organosilicon polymer fine particle, a coverage ratio of the hydrotalcite particle surface by the organosilicon polymer fine particle is from 1% to 50%, and given A (nm) as the number-average particle diameter of the primary particles of the organosilicon polymer fine particle and B (nm) as the number-average particle diameter of the primary particles of the hydrotalcite particle, the toner satisfies the following formula (I) and formula (II): A<B??(I) 20?A?350??(II).Type: ApplicationFiled: December 27, 2019Publication date: July 2, 2020Inventors: Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka
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Publication number: 20200209767Abstract: A toner including a toner particle containing a binder resin and an external additive, wherein the external additive contains composite particles of an organosilicon polymer fine particle and a fatty acid metal salt.Type: ApplicationFiled: December 27, 2019Publication date: July 2, 2020Inventors: Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga, Masatake Tanaka, Taiji Katsura
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Publication number: 20200209775Abstract: A toner containing: a toner particle that contains a binder resin and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the binder resin contains an amorphous resin and a crystalline polyester resin, a content of the crystalline polyester resin in the binder resin is from 5 to 30 mass %, and the crystalline polyester resin contains from 5 to 25 mass % of a component having a molecular weight of not more than 2,500.Type: ApplicationFiled: December 27, 2019Publication date: July 2, 2020Inventors: Masatake Tanaka, Taiji Katsura, Masamichi Sato, Shohei Kototani, Kentaro Yamawaki, Tsuneyoshi Tominaga
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Patent number: 10635011Abstract: A toner comprising a toner particle having a binder resin, a wax and a colorant, and metal titanate fine particles having a perovskite crystal structure, wherein in cross section observation of the toner using a transmission electron microscope, when a proportion of an area occupied by the wax in a surface layer region from the surface of the toner particle to a depth of 1.0 ?m is denoted by As, the As is from 5.0% to 30.0%, and a number average particle diameter of primary particles of the metal titanate fine particles is from 10 nm to 80 nm.Type: GrantFiled: April 24, 2019Date of Patent: April 28, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Noriyoshi Umeda, Tsuneyoshi Tominaga, Hidekazu Fumita, Taiji Katsura, Shinsuke Mochizuki
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Publication number: 20190332024Abstract: A toner comprising a toner particle having a binder resin, a wax and a colorant, and metal titanate fine particles having a perovskite crystal structure, wherein in cross section observation of the toner using a transmission electron microscope, when a proportion of an area occupied by the wax in a surface layer region from the surface of the toner particle to a depth of 1.0 ?m is denoted by As, the As is from 5.0% to 30.0%, and a number average particle diameter of primary particles of the metal titanate fine particles is from 10 nm to 80 nm.Type: ApplicationFiled: April 24, 2019Publication date: October 31, 2019Inventors: Noriyoshi Umeda, Tsuneyoshi Tominaga, Hidekazu Fumita, Taiji Katsura, Shinsuke Mochizuki
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Patent number: 10409186Abstract: A toner is provided, where good cleanability is exhibited, abrasion variations of the photo conductor surface is reduced, and contamination of a charge member is reduced. The toner includes toner particles and organic-inorganic composite fine particles on the toner particle surfaces, wherein each of the organic-inorganic composite fine particles is a particle in which inorganic fine particles are exposed at the surfaces of vinyl based resin particles in such a way that convex portions derived from the inorganic fine particles are formed on the surfaces, the average circularity of the toner is 0.960 or more, and the absolute value Q of the amount of triboelectricity of the toner measured by a two-component method and the electrostatic adhesion F of the toner satisfy 0.003?F/Q2?0.040.Type: GrantFiled: July 30, 2014Date of Patent: September 10, 2019Assignee: Canon Kabushiki KaishaInventors: Yojiro Hotta, Shohei Tsuda, Taiji Katsura, Masaharu Miura, Yoshinobu Baba, Takayuki Itakura
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Patent number: 10114303Abstract: A toner including a toner particle that contains a binder resin, a polyester resin A and a wax, wherein the polyester resin A contains a specific amount of an isosorbide unit based on a total number of monomer units constituting the polyester resin A, the content of the polyester resin A is a specific amount, and when observing a cross-section of the toner, twenty toner particle cross-sections are selected that have a major axis R (?m) that satisfies a specific relationship with respect to the weight-average diameter D4 (?m) of the toner, each major axis r that have the largest major axis is measured for those domains composed of wax present in the selected toner particle cross-sections, and the arithmetic mean (r/R)st of the determined r/R satisfies a specific relationship.Type: GrantFiled: February 24, 2015Date of Patent: October 30, 2018Assignee: CANON KABUSHIKI KAISHAInventors: Taiji Katsura, Yasushi Katsuta, Katsuyuki Nonaka, Takashi Kenmoku, Shohei Shibahara, Tsutomu Shimano
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Publication number: 20180210361Abstract: A toner including a toner particle that contains a binder resin, a polyester resin A and a wax, wherein the polyester resin A contains a specific amount of an isosorbide unit based on a total number of monomer units constituting the polyester resin A, the content of the polyester resin A is a specific amount, and when observing a cross-section of the toner, twenty toner particle cross-sections are selected that have a major axis R (?m) that satisfies a specific relationship with respect to the weight-average diameter D4 (?m) of the toner, each major axis r that have the largest major axis is measured for those domains composed of wax present in the selected toner particle cross-sections, and the arithmetic mean (r/R)st of the determined r/R satisfies a specific relationship.Type: ApplicationFiled: March 20, 2018Publication date: July 26, 2018Inventors: Taiji Katsura, Yasushi Katsuta, Katsuyuki Nonaka, Takashi Kenmoku, Shohei Shibahara, Tsutomu Shimano
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Patent number: 9720340Abstract: Provided is a toner that has satisfactory chargeability and hardly causes a reduction in image density, fogging, and density unevenness in various environments ranging from a low-temperature and low-humidity environment to a high-temperature and high-humidity environment. The toner includes toner particles obtained by fixing resin particles to toner base particles each containing resins, in which: the resins contain 50.0 mass % or more of a styrene-acrylic resin and 1.0 to 40.0 mass % of a polyester resin A; the polyester resin A contains 0.10 to 30.00 number % of an isosorbide unit; the fixing amount of the resin particles to the toner base particles is from 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the toner base particles; and the glass transition temperature of the resin particles is higher than the glass transition temperature of the toner base particles.Type: GrantFiled: May 8, 2015Date of Patent: August 1, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Tsuneyoshi Tominaga, Yasushi Katsuta, Katsuyuki Nonaka, Taiji Katsura, Akane Masumoto, Harumi Takada, Kohei Mizushima
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Patent number: 9645518Abstract: A toner contains toner particles having a surface layer containing an organosilicon polymer. The organosilicon polymer has a particular partial structure. The surface layer has a particular average thickness Dav. The ratio of silicon ions to carbon ions emitted from the toner particles in response to irradiation of the toner particles with primary ions in mapping measurement by FIB-TOF-SIMS is specified.Type: GrantFiled: June 22, 2015Date of Patent: May 9, 2017Assignee: Canon Kabushiki KaishaInventors: Koji Abe, Yuhei Terui, Taiji Katsura, Naoya Isono, Katsuyuki Nonaka
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Patent number: 9632441Abstract: The present invention is a toner that has toner particles that have a surface layer that contains an organosilicon polymer, wherein this organosilicon polymer has a specific substructure and the ratio [ST3], in a 29Si-NMR measurement of a tetrahydrofuran-insoluble matter of the toner particles, of the peak area for this substructure to the total peak area for the organosilicon polymer satisfies the relationship ST3?0.40.Type: GrantFiled: October 8, 2014Date of Patent: April 25, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Koji Abe, Yuhei Terui, Taiji Katsura, Katsuyuki Nonaka
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Publication number: 20170060008Abstract: It is intended to provide an image forming method, a process cartridge and an electrophotographic apparatus which have favorable cleaning properties and can suppress reduction in image quality caused by the contamination of a charging member. A surface layer of an electrophotographic photosensitive member satisfies the condition (i) or (ii), and toner contains a resin having an isosorbide unit: (i) containing a fluorine resin particle and at lease one resin selected from the group consisting of a polyarylate resin and a polycarbonate resin, and (ii) containing at least one resin selected from the group consisting of a polyarylate resin and a polycarbonate resin each having a polysiloxane structure.Type: ApplicationFiled: August 19, 2016Publication date: March 2, 2017Inventors: Atsushi Okuda, Yuki Yamamoto, Kazunori Noguchi, Yuka Ishiduka, Takashi Kenmoku, Shohei Shibahara, Taiji Katsura, Yasuhiro Hashimoto