Patents by Inventor Shohei Tsuda
Shohei Tsuda 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: 9606462Abstract: 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: GrantFiled: July 31, 2015Date of Patent: March 28, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Shotaro Nomura, Koji Nishikawa, Kosuke Fukudome, Daisuke Yoshiba, Shohei Tsuda, Hiroki Akiyama, Katsuhisa Yamazaki
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Patent number: 9588450Abstract: Provided is a magnetic toner in which enhancement of initial transfer efficiency and transfer efficiency that is stable during a long-term use are achieved by simultaneously suppressing the friction force between the toner and a drum and the cohesion between toners, and further the degradation in chargeability and fluidity caused by the deterioration of the toner. The magnetic toner includes: a magnetic toner particle; a first external additive; and a second external additive. The first external additive includes an organic-inorganic composite fine particle, a plurality of convexes derived from an inorganic fine particle being present on a surface of the organic-inorganic composite fine particle, and has a number-average particle diameter of 50 nm or more and 500 nm or less. The second external additive includes a silica fine particle and has a number-average particle diameter of 5 nm or more and 30 nm or less. A shear load calculated from a rotation torque is 0.50 kPa or more and 2.Type: GrantFiled: July 30, 2014Date of Patent: March 7, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Shohei Tsuda, Koji Nishikawa, Katsuhisa Yamazaki, Yojiro Hotta, Kazuo Terauchi, Motohide Shiozawa, Takeshi Naka, Takuya Mizuguchi, Takayuki Itakura
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Patent number: 9575461Abstract: 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: GrantFiled: August 6, 2015Date of Patent: February 21, 2017Assignee: Canon Kabushiki KaishaInventors: Hiroki Akiyama, Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Daisuke Yoshiba, Shohei Tsuda, Katsuhisa Yamazaki
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Patent number: 9575425Abstract: A toner is provided including large particle-diameter external additives with sweep to the concaves of a toner particle suppressed, so that the large particle-diameter external additives function as spacer particles for a long period. The toner includes toner particles which contain a binder resin and magnetic material, and organic-inorganic composite fine particles having a structure including inorganic fine particles embedded in a vinyl resin particle. The presence state of the magnetic material on the toner particle surface satisfies specific conditions and the presence state of the organic-inorganic composite fine particles on the toner surface satisfies specific conditions.Type: GrantFiled: July 29, 2014Date of Patent: February 21, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Takeshi Naka, Kazuo Terauchi, Motohide Shiozawa, Yojiro Hotta, Shohei Tsuda, Katsuhisa Yamazaki, Koji Nishikawa, Takayuki Itakura
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Patent number: 9470993Abstract: The present invention provides a magnetic toner that is excellent in low temperature fixability and that is also excellent in developability, suppression of fogging and transfer efficiency even in a long period of use. The magnetic toner of the present invention is a magnetic toner including a magnetic toner particle containing a binder resin and a magnetic member, and an inorganic fine particle “a” and an organic-inorganic composite fine particle, wherein the magnetic toner has (i) a true specific gravity of 1.40 g/cm3 or more and 1.70 g/cm3 or less, and (ii) a saturation magnetization at a magnetic field of 796 kA/m of 10 Am2/kg or more and 20 Am2/kg or less, and the inorganic fine particle “a” is a metal oxide having a volume resistivity of 1.0×103 ?·cm or more and 1.0×108 ?·cm or less.Type: GrantFiled: July 23, 2015Date of Patent: October 18, 2016Assignee: CANON KABUSHIKI KAISHAInventors: Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Hiroki Akiyama, Shohei Tsuda, Daisuke Yoshiba, Katsuhisa Yamazaki
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Publication number: 20160202621Abstract: 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: ApplicationFiled: July 30, 2014Publication date: July 14, 2016Inventors: Yojiro Hotta, Shohei Tsuda, Taiji Katsura, Masaharu Miura, Yoshinobu Baba, Takayuki Itakura
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Publication number: 20160154331Abstract: Provided is toner comprising toner particle containing binder resin and colorant and silica fine particle, wherein: the silica fine particle contains silica fine particle A and silica fine particle B; silica fine particle A has a number average particle diameter of primary particle of 5 nm or more and 20 nm or less; silica fine particle B has a number average particle diameter of primary particle of 80 nm or more and 200 nm or less; and silica fine particle B has a half width of a peak of primary particle of 25 nm or less, in a weight-based particle size distribution, and wherein when the toner is measured by adhesive force-measuring method by using polycarbonate thin film, an adhesion of the silica fine particle A is 0.5% by area or less relative to 100% by area of the total area of the polycarbonate thin film.Type: ApplicationFiled: November 17, 2015Publication date: June 2, 2016Inventors: Keisuke Tanaka, Takashi Matsui, Satoshi Arimura, Kozue Uratani, Shohei Tsuda, Naoki Okamoto
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Publication number: 20160139521Abstract: Provided is a toner, including: a toner particle containing a binder resin and a colorant; and an inorganic fine particle, in which the toner particle has an average circularity of 0.960 or more, and in which the toner satisfies the formula (1) and the formula (2). Fp(A)?25.0 nN??Formula (1) (Fp(B)?Fp(A))/Fp(A)?0.Type: ApplicationFiled: October 26, 2015Publication date: May 19, 2016Inventors: Shohei Tsuda, Takashi Matsui, Satoshi Arimura, Kozue Uratani, Keisuke Tanaka, Naoki Okamoto
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Publication number: 20160091809Abstract: Provided is a magnetic toner in which enhancement of initial transfer efficiency and transfer efficiency that is stable during a long-term use are achieved by simultaneously suppressing the friction force between the toner and a drum and the cohesion between toners, and further the degradation in chargeability and fluidity caused by the deterioration of the toner. The magnetic toner includes: a magnetic toner particle; a first external additive; and a second external additive. The first external additive includes an organic-inorganic composite fine particle, a plurality of convexes derived from an inorganic fine particle being present on a surface of the organic-inorganic composite fine particle, and has a number-average particle diameter of 50 nm or more and 500 nm or less. The second external additive includes a silica fine particle and has a number-average particle diameter of 5 nm or more and 30 nm or less. A shear load calculated from a rotation torque is 0.50 kPa or more and 2.Type: ApplicationFiled: July 30, 2014Publication date: March 31, 2016Inventors: Shohei Tsuda, Koji Nishikawa, Katsuhisa Yamazaki, Yojiro Hotta, Kazuo Terauchi, Motohide Shiozawa, Takeshi Naka, Takuya Mizuguchi, Takayuki Itakura
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Publication number: 20160070192Abstract: The toner comprising a toner particle containing a binder resin and a colorant, an iron oxide particle and an organic-inorganic composite fine particle, wherein the organic-inorganic composite fine particle comprises a vinyl resin particle, and inorganic fine particles which are embedded in the vinyl resin particle, and at least a part of which is exposed at surface of the organic-inorganic composite fine particle; the organic-inorganic composite fine particle has convexes derived from the inorganic fine particles, and wherein: a coverage ratio of the surface of the organic-inorganic composite fine particle with the inorganic fine particle is 20-70%; and the content of the iron oxide particle present on a surface of the toner particle is 0.1-5.0 mass % based on the mass of the toner particle.Type: ApplicationFiled: July 30, 2014Publication date: March 10, 2016Inventors: Kazuo Terauchi, Koji Nishikawa, Shohei Tsuda, Yojiro Hotta, Katsuhisa Yamazaki, Takayuki Itakura, Takeshi Naka, Motohide Shiozawa
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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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Publication number: 20160041482Abstract: A toner having compatibility between transfer properties and cleaning properties is provided. A toner wherein a fine particle A containing a primary particle having a number average particle diameter (D1) of 80 nm or more and 400 nm or less is present on the surface of a toner particle at a coverage ratio of 5 to 40%, a fixing rate of 30 to 90% by mass, and a variation coefficient of 0.1 to 0.5 in a region of 0.5 ??m2.Type: ApplicationFiled: August 3, 2015Publication date: February 11, 2016Inventors: Kazuo Terauchi, Yojiro Hotta, Takeshi Naka, Motohide Shiozawa, Shohei Tsuda, Masami Fujimoto
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Publication number: 20160041484Abstract: Provided is a toner having good endurance stability and good low-temperature fixability in high-speed printing, and having good resistance to the adhesion of printed paper. The toner is a magnetic toner having, on the surface of toner particle containing a binder resin and an ester compound as a releasing agent, inorganic fine particle “a” and organic-inorganic composite fine particle having a volumetric specific heat of from 2,900 kJ/(m3·° C.) to 4,200 kJ/(m3·° C.), in which a coverage A of the surface of the toner particle with the inorganic fine particle “a” is 45.0% or more and 70.0% or less.Type: ApplicationFiled: July 29, 2015Publication date: February 11, 2016Inventors: Shohei Tsuda, Yojiro Hotta, Koji Nishikawa, Masami Fujimoto, Katsuhisa Yamazaki
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Publication number: 20160041483Abstract: The present invention provides a magnetic toner that is excellent in low temperature fixability and that is also excellent in developability, suppression of fogging and transfer efficiency even in a long period of use. The magnetic toner of the present invention is a magnetic toner including a magnetic toner particle containing a binder resin and a magnetic member, and an inorganic fine particle “a” and an organic-inorganic composite fine particle, wherein the magnetic toner has (i) a true specific gravity of 1.40 g/cm3 or more and 1.70 g/cm3 or less, and (ii) a saturation magnetization at a magnetic field of 796 kA/m of 10 Am2/kg or more and 20 Am2/kg or less, and the inorganic fine particle “a” is a metal oxide having a volume resistivity of 1.0×103 ?·cm or more and 1.0×108 ?·cm or less.Type: ApplicationFiled: July 23, 2015Publication date: February 11, 2016Inventors: Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Hiroki Akiyama, Shohei Tsuda, Daisuke Yoshiba, Katsuhisa Yamazaki
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Publication number: 20150125790Abstract: A magnetic toner having a toner particle containing a binder resin and a magnetic member, a first inorganic fine particle and an organic-inorganic composite particle on the surface of the toner particle, wherein the organic-inorganic composite particle i) has a structure in which a second inorganic fine particle is embedded in a resin particle, and ii) is contained in an amount of 0.5 mass % or more and 3.0 mass % or less based on the mass of the toner; the first inorganic fine particle contains an inorganic oxide fine particle selected from the group consisting of a silica fine particle, a titanium oxide fine particle and an alumina fine particle; has a number average particle diameter (D1) of 5 nm or more and 25 nm or less, and contains the silica fine particle in an amount of 85 mass % or more based on the inorganic oxide fine particle.Type: ApplicationFiled: January 13, 2015Publication date: May 7, 2015Inventors: Yojiro Hotta, Koji Nishikawa, Shohei Tsuda, Motohide Shiozawa, Takeshi Naka, Kazuo Terauchi, Katsuhisa Yamazaki, Takayuki Itakura
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Publication number: 20150037719Abstract: A toner is provided including large particle-diameter external additives with sweep to the concaves of a toner particle suppressed, so that the large particle-diameter external additives function as spacer particles for a long period. The toner includes toner particles which contain a binder resin and magnetic material, and organic-inorganic composite fine particles having a structure including inorganic fine particles embedded in a vinyl resin particle. The presence state of the magnetic material on the toner particle surface satisfies specific conditions and the presence state of the organic-inorganic composite fine particles on the toner surface satisfies specific conditions.Type: ApplicationFiled: July 29, 2014Publication date: February 5, 2015Inventors: Takeshi Naka, Kazuo Terauchi, Motohide Shiozawa, Yojiro Hotta, Shohei Tsuda, Katsuhisa Yamazaki, Koji Nishikawa, Takayuki Itakura
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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