Patents by Inventor Shotaro Nomura
Shotaro Nomura 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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Publication number: 20160041481Abstract: To provide a toner from which an image having a stable image density can be obtained with reduced occurrence of pollution of members, even when a toner container is filled with a larger amount of toner than a conventional amount for long-term use. A toner including a toner particle and an external additive containing an organic-inorganic composite fine particle and an inorganic fine particle A; wherein the organic-inorganic composite fine particle includes a resin particle and an inorganic fine particle B, the resin particle has a surface with a convex derived from the inorganic fine particle B; has a specific number average particle diameter (D1) and a specific shape factor SF-2; and has a specific fixed state to the toner particle; the organic-inorganic composite fine particle has a specific unit diffusion index on the toner particle surface; the inorganic fine particle A has a specific BET specific surface area.Type: ApplicationFiled: July 31, 2015Publication date: February 11, 2016Inventors: Shotaro Nomura, Koji Nishikawa, Kosuke Fukudome, Daisuke Yoshiba, Shohei Tsuda, Hiroki Akiyama, Katsuhisa Yamazaki
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Publication number: 20160041520Abstract: Provided is a process cartridge by which the stability of an image having a high print percentage can be obtained even when high-density loading is performed. The process cartridge is a process cartridge in which a toner having a uniaxial collapse stress at the time of a maximum consolidation stress of 10.0 kPa of 2.0 kPa or more and 4.5 kPa or less, and a total energy measured after its compression of 70 mJ or more and 95 mJ or less is stored in a toner container in a state in which the container has a loading density of 0.70 g/cm3 or more.Type: ApplicationFiled: August 6, 2015Publication date: February 11, 2016Inventors: Hiroki Akiyama, Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Daisuke Yoshiba, Shohei Tsuda, Katsuhisa Yamazaki
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Patent number: 9250548Abstract: The toner comprises: toner particles each containing a binder resin and a releasing agent; and an organic-inorganic composite fine particle, wherein: the organic-inorganic composite fine particle comprises: a vinyl resin particle containing a vinyl resin, the vinyl resin containing THF-insoluble matter in an amount of 95% by mass or more; and inorganic fine particles which are exposed at surfaces of the respective organic-inorganic composite fine particles, the organic-inorganic composite fine particle 1) has a plurality of convexes derived from the inorganic fine particles on the surfaces thereof, 2) has a number average particle size of 70-500 nm, and 3) has a shape factor SF-2 as measured at a magnification of 200,000 times of 103-120, and an absolute value of difference between an SP value of the releasing agent and an SP value of the vinyl resin is 0.50 (cal/cm3)1/2 or less.Type: GrantFiled: July 24, 2014Date of Patent: February 2, 2016Assignee: CANON KABUSHIKI KAISHAInventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Koji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
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Patent number: 9217943Abstract: The magnetic toner contains magnetic toner particles containing a binder resin and a magnetic body, and inorganic fine particles present on the surface of the magnetic toner particles. The coverage ratio of the magnetic toner particle surface by the inorganic fine particles resides in a prescribed range for this magnetic toner; the binder resin is a styrene resin; the weight-average molecular weight and radius of gyration of the magnetic toner reside in a prescribed relationship; and the viscosity of the magnetic toner at 110° C. resides in a prescribed range.Type: GrantFiled: December 26, 2012Date of Patent: December 22, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Takashi Matsui, Yusuke Hasegawa, Shotaro Nomura, Michihisa Magome
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Patent number: 9213250Abstract: Disclosed is a toner which enables a stable image density to be obtained, regardless of the service environment, throughout use in durability tests, and which is able to suppress the occurrence of faulty cleaning. The toner contains both toner particles, which include a binder resin and a colorant, and also silica fine particles. The toner has an average circularity of at least 0.950, a static friction coefficient, with respect to a polycarbonate resin substrate, of at least 0.100 and not more than 0.200, and a coverage ratio X1 of the toner surface by the silica fine particles, as determined by X-ray photoelectron spectroscopy (ESCA), of at least 50.0 area %, and not more than 75.0 area %.Type: GrantFiled: September 30, 2013Date of Patent: December 15, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Shotaro Nomura, Yusuke Hasegawa, Takashi Matsui, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori
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Patent number: 9201323Abstract: A toner excellent in end-portion hot offset properties is provided. A toner including toner particles and an external additive, wherein the toner particles contain a binder resin, and organic-inorganic composite fine particles dispersed in the binder resin, and the organic-inorganic composite fine particles (1) have a number-average particle diameter of 70 nm or more and 500 nm or less, (2) have a structure in which inorganic fine particles are embedded in a resin particle, convexes derived from the inorganic fine particles being present on surfaces of the organic-inorganic composite fine particles, (3) have a shape factor SF-2 of 103 or more and 120 or less, and (4) contain a resin component in which a proportion of THF-insoluble matter based on a mass of the resin component is 95% by mass or more.Type: GrantFiled: July 25, 2014Date of Patent: December 1, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Koji Nishikawa, Katsuhisa Yamazaki, Daisuke Yoshiba, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
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Patent number: 9097997Abstract: A magnetic toner is provided that exhibits an excellent electrostatic offset resistance both initially and after long-term use. The magnetic toner contains: magnetic toner particles containing a binder resin and a magnetic body; and inorganic fine particles present on the surface of the magnetic toner particles, wherein the inorganic fine particles present on the surface of the magnetic toner particles contain a prescribed metal oxide fine particle in a prescribed proportion; the magnetic toner has prescribed numerical value ranges for a coverage ratio A of the magnetic toner particle surface covered by the inorganic fine particles and for a coverage ratio B by the inorganic fine particles that are fixed to the magnetic toner particle surface; the magnetic toner particle contains a crystalline polyester; and measurement of the magnetic toner with a differential scanning calorimeter provides a characteristic differential scanning calorimetric curve.Type: GrantFiled: January 31, 2013Date of Patent: August 4, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Shotaro Nomura, Michihisa Magome, Yusuke Hasegawa, Takashi Matsui
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Publication number: 20150037723Abstract: A toner excellent in end-portion hot offset properties is provided. A toner including toner particles and an external additive, wherein the toner particles contain a binder resin, and organic-inorganic composite fine particles dispersed in the binder resin, and the organic-inorganic composite fine particles (1) have a number-average particle diameter of 70 nm or more and 500 nm or less, (2) have a structure in which inorganic fine particles are embedded in a resin particle, convexes derived from the inorganic fine particles being present on surfaces of the organic-inorganic composite fine particles, (3) have a shape factor SF-2 of 103 or more and 120 or less, and (4) contain a resin component in which a proportion of THF-insoluble matter based on a mass of the resin component is 95% by mass or more.Type: ApplicationFiled: July 25, 2014Publication date: February 5, 2015Inventors: Koji Nishikawa, Katsuhisa Yamazaki, Daisuke Yoshiba, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
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Publication number: 20150037726Abstract: The toner comprises: toner particles each containing a binder resin and a releasing agent; and an organic-inorganic composite fine particle, wherein: the organic-inorganic composite fine particle comprises: a vinyl resin particle containing a vinyl resin, the vinyl resin containing THF-insoluble matter in an amount of 95% by mass or more; and inorganic fine particles which are exposed at surfaces of the respective organic-inorganic composite fine particles, the organic-inorganic composite fine particle 1) has a plurality of convexes derived from the inorganic fine particles on the surfaces thereof, 2) has a number average particle size of 70-500 nm, and 3) has a shape factor SF-2 as measured at a magnification of 200,000 times of 103-120, and an absolute value of difference between an SP value of the releasing agent and an SP value of the vinyl resin is 0.50 (cal/cm3)1/2 or less.Type: ApplicationFiled: July 24, 2014Publication date: February 5, 2015Inventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Kouji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
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Publication number: 20150037729Abstract: The toner includes a resin component containing a crystalline polyester resin and a polyester-type resin that has a long-chain monomer bonded by condensation at a terminal, the toner having, in a total heat flow measured by a temperature-modulated differential scanning calorimeter, an endothermic peak resulting from the crystalline polyester resin in a specific temperature range, and the percentage of the endothermic quantity of the endothermic peak in a reversing heat flow with respect to the endothermic quantity of the endothermic peak in the total heat flow being at least 20.0%.Type: ApplicationFiled: July 29, 2014Publication date: February 5, 2015Inventors: Daisuke Yoshiba, Katsuhisa Yamazaki, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
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Publication number: 20150037722Abstract: The present invention provides a toner that exhibits an excellent low-temperature fixability and an excellent ejected paper adhesiveness during high-speed printing, without affecting the long-term storage stability, in which the toner has a toner particle that contains a resin component, wherein the toner has, in a DSC curve measured with a differential scanning calorimeter, a glass transition temperature of at least 50° C. and not more than 65° C. and a cold crystallization peak during cooling of at least 40° C. and not more than 70° C., and has an endothermic peak in a DSC curve measured with a differential scanning calorimeter for the resin component of at least 70° C. and not more than 95° C.Type: ApplicationFiled: July 28, 2014Publication date: February 5, 2015Inventors: Katsuhisa Yamazaki, Daisuke Yoshiba, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
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Publication number: 20150037720Abstract: Provided is magnetic toner capable of favorably maintain fluidity of the magnetic toner in a developing unit even after a large number of image formation. The magnetic toner to which an external additive that has 1) a number average particle diameter of 70 or more and 200 or less, 2) a shape factor SF-1 of 100 or more and 250 or less, and 3) a shape factor SF-2 of 105 or more and 250 or less, is added, and a covering rate by silica on the surfaces of toner particles is 40.0% or more and 70.0% or less, and the magnetic toner has specific fluidity.Type: ApplicationFiled: July 29, 2014Publication date: February 5, 2015Inventors: Shohei Tsuda, Yojiro Hotta, Kouji Nishikawa, Shotaro Nomura, Katsuhisa Yamazaki, Masami Fujimoto, Takayuki Itakura
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Publication number: 20150037721Abstract: Provided is a toner that has excellent low-temperature fixability and is capable of obtaining an image having a stable image density, in which the occurrence of image defects is suppressed. The toner includes toner base particles, each of which contains a binder resin and a magnetic material, and organic-inorganic composite fine particles on each of the toner base particles. Each of the organic-inorganic composite fine particles comprises a vinyl resin particle, and inorganic fine particles which are embedded in the vinyl resin particle, and at least a part of which are exposed. The volumetric specific heat of the organic-inorganic composite fine particles and the volumetric specific heat of the toner base particles satisfy a predetermined provision.Type: ApplicationFiled: July 30, 2014Publication date: February 5, 2015Inventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Kouji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
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Publication number: 20140335450Abstract: A magnetic toner is provided that exhibits an excellent electrostatic offset resistance both initially and after long-term use. The magnetic toner contains: magnetic toner particles containing a binder resin and a magnetic body; and inorganic fine particles present on the surface of the magnetic toner particles, wherein the inorganic fine particles present on the surface of the magnetic toner particles contain a prescribed metal oxide fine particle in a prescribed proportion; the magnetic toner has prescribed numerical value ranges for a coverage ratio A of the magnetic toner particle surface covered by the inorganic fine particles and for a coverage ratio B by the inorganic fine particles that are fixed to the magnetic toner particle surface; the magnetic toner particle contains a crystalline polyester; and measurement of the magnetic toner with a differential scanning calorimeter provides a characteristic differential scanning calorimetric curve.Type: ApplicationFiled: January 31, 2013Publication date: November 13, 2014Inventors: Shotaro Nomura, Michihisa Magome, Yusuke Hasegawa, Takashi Matsui
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Patent number: 8883389Abstract: An object of the present invention is to provide a developing apparatus which is less affected by usage environments, has high development efficiency for long term use and can provide a high quality image without image density non-uniformity. The present invention relates to a developing apparatus wherein a magnetic toner-carrying member has a work function value at the surface thereof within a specific range, a toner regulating member which regulates toner carried on the magnetic toner-carrying member is made of a specific material at a portion contacting the magnetic toner, the magnetic toner has an average circularity of 0.950 or more and the magnetic toner has a surface tension index within a specific range.Type: GrantFiled: December 21, 2012Date of Patent: November 11, 2014Assignee: Canon Kabushiki KaishaInventors: Takashi Matsui, Michihisa Magome, Shotaro Nomura, Atsuhiko Ohmori
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Publication number: 20140315125Abstract: The magnetic toner contains magnetic toner particles containing a binder resin and a magnetic body, and inorganic fine particles present on the surface of the magnetic toner particles, wherein the inorganic fine particles present on the surface of the magnetic toner particles comprise metal oxide fine particles, wherein the metal oxide fine particles containing silica fine particles, and optionally containing titania fine particles and alumina fine particles, and a content of the silica fine particles being at least 85 mass % with respect to a total mass of the silica fine particles, the titania fine particles and the alumina fine particles. In addition, the coverage ratio of the magnetic toner particle surface by the inorganic fine particles resides in a prescribed range for this magnetic toner; the binder resin is a styrene resin; the weight-average molecular weight and radius of gyration of the magnetic toner reside in a prescribed relationship; and the viscosity of the magnetic toner at 110° C.Type: ApplicationFiled: December 26, 2012Publication date: October 23, 2014Inventors: Takashi Matsui, Yusuke Hasegawa, Shotaro Nomura, Michihisa Magome
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Patent number: 8835090Abstract: An object of the present invention is to provide a developing apparatus which is less affected by usage environments, has high development efficiency for long term use and can provide a high quality image without image density non-uniformity. The present invention relates to a developing apparatus wherein a magnetic toner-carrying member has a work function value at the surface thereof within a specific range, a toner regulating member which regulates toner carried on the magnetic toner-carrying member is made of a specific material at a portion contacting the magnetic toner, the magnetic toner has an average circularity of 0.950 or more and the magnetic toner has a surface tension index within a specific range.Type: GrantFiled: December 21, 2012Date of Patent: September 16, 2014Assignee: Canon Kabushiki KaishaInventors: Takashi Matsui, Michihisa Magome, Shotaro Nomura, Atsuhiko Ohmori
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Patent number: 8778585Abstract: A toner with good low-temperature fixability even in light-pressure type fixing units, which causes no contamination of fixing films and provides images having stable image densities and excellent image quality after long-term use. The toner includes a toner particle containing a binder resin, a coloring agent, a release agents (a) and (b) The release agent (a) is a monofunctional or bifunctional ester wax; the release agent (b) is a hydrocarbon wax; a solubility of the release agent (a) into the binder resin is higher than that of the release agent (b). When tetrahydrofuran-soluble components of the toner are subjected to GPC, a proportion of components having a molecular weight of 500 or less is 2.5 area % or less. When the tetrahydrofuran-soluble components at 25° C. are subjected to SEC-MALLS, a weight-average molecular weight Mw thereof is 5,000-100,000, and the Mw and the radius of gyration Rw thereof satisfy 5.0×10?4?Rw/Mw?1.0×10?2.Type: GrantFiled: September 12, 2011Date of Patent: July 15, 2014Assignee: Canon Kabushiki KaishaInventors: Takashi Matsui, Michihisa Magome, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura
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Publication number: 20140030645Abstract: Disclosed is a toner which enables a stable image density to be obtained, regardless of the service environment, throughout use in durability tests, and which is able to suppress the occurrence of faulty cleaning. The toner contains both toner particles, which include a binder resin and a colorant, and also silica fine particles. The toner has an average circularity of at least 0.950, a static friction coefficient, with respect to a polycarbonate resin substrate, of at least 0.100 and not more than 0.200, and a coverage ratio X1 of the toner surface by the silica fine particles, as determined by X-ray photoelectron spectroscopy (ESCA), of at least 50.0 area %, and not more than 75.0 area %.Type: ApplicationFiled: September 30, 2013Publication date: January 30, 2014Applicant: CANON KABUSHIKI KAISHAInventors: Shotaro Nomura, Yusuke Hasegawa, Takashi Matsui, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori
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Patent number: 8614044Abstract: To provide a toner which can achieve both low-temperature fixing performance and dot reproducibility and further can obtain images on which any density non-uniformity has been kept from coming about, the toner has toner particles, each of the toner particles has a toner base particle containing a binder resin, a colorant and a release agent, and an inorganic fine powder; the toner having: (1) an average circularity of 0.960 or more; (2) a number-average molecular weight Mn(25° C.) of from 500 or more to 3,000 or less in measuring a tetrahydrofuran-soluble matter at 25° C. of the toner by SEC-MALLS; and (3) a value of Mn(135° C.)/Mn(25° C.) of from 25 or more to 50 or less which is the ratio of number-average molecular weight Mn(135° C.) in measuring an o-dichlorobenzene-soluble matter at 135° C. of the toner by SEC-MALLS to number-average molecular weight Mn(25° C.) in measuring a tetrahydrofuran-soluble matter at 25° C. of the toner by SEC-MALLS.Type: GrantFiled: June 13, 2011Date of Patent: December 24, 2013Assignee: Canon Kabushiki KaishaInventors: Takashi Matsui, Michihisa Magome, Yusuke Hasegawa, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura, Atsuhiko Ohmori