Patents by Inventor Koji Nishikawa

Koji Nishikawa 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).

  • Patent number: 9588450
    Abstract: 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: Grant
    Filed: July 30, 2014
    Date of Patent: March 7, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shohei Tsuda, Koji Nishikawa, Katsuhisa Yamazaki, Yojiro Hotta, Kazuo Terauchi, Motohide Shiozawa, Takeshi Naka, Takuya Mizuguchi, Takayuki Itakura
  • Patent number: 9575461
    Abstract: 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: Grant
    Filed: August 6, 2015
    Date of Patent: February 21, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroki Akiyama, Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Daisuke Yoshiba, Shohei Tsuda, Katsuhisa Yamazaki
  • Patent number: 9575425
    Abstract: 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: Grant
    Filed: July 29, 2014
    Date of Patent: February 21, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takeshi Naka, Kazuo Terauchi, Motohide Shiozawa, Yojiro Hotta, Shohei Tsuda, Katsuhisa Yamazaki, Koji Nishikawa, Takayuki Itakura
  • Patent number: 9470993
    Abstract: 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: Grant
    Filed: July 23, 2015
    Date of Patent: October 18, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Hiroki Akiyama, Shohei Tsuda, Daisuke Yoshiba, Katsuhisa Yamazaki
  • Publication number: 20160202624
    Abstract: Provided is a toner, including: a toner particle; and an organic-inorganic composite fine particle on a surface of the toner particle, in which the organic-inorganic composite fine particle includes: a resin fine particle; and an inorganic fine particle embedded in the resin fine particle, and part of which is exposed to a surface of the composite fine particle, and in which the composite fine particle satisfies the following relationships: (i) in viscoelasticity measurement of the composite fine particle, when the loss elastic modulus thereof at a temperature T (° C.) is represented by G?T [dN/m2], a change ratio d(Log(G?T))/dT of a common logarithm of the loss elastic modulus has a minimum in a temperature range of from 60° C. to 150° C., and the minimum is less than ?0.10; and (ii) the loss elastic modulus (G?180) thereof at a temperature of 180° C. is 1.0×104 dN/m2 or more and 1.0×107 dN/m2 or less.
    Type: Application
    Filed: December 18, 2015
    Publication date: July 14, 2016
    Inventors: Koji Nishikawa, Shuhei Moribe, Daisuke Yoshiba, Shotaro Nomura, Kosuke Fukudome, Hiroki Akiyama, Yojiro Hotta, Katsuhisa Yamazaki
  • Publication number: 20160161874
    Abstract: A magnetic toner comprising a toner particle containing a styrene resin as a binder resin and a magnetic substance, and a first inorganic fine particle on surface of the toner particle and an organic-inorganic composite fine particle on the surface of the toner particle, wherein the first inorganic fine particle i) contains at least one inorganic oxide fine particle selected from the group consisting of silica fine particle, titanium oxide fine particle and alumina fine particle, with the proviso that the inorganic oxide fine particle contains silica fine particle in an amount of 85 mass % or more based on the total mass of the inorganic oxide fine particle, and ii) has a number-average particle diameter (D1) of 5 nm or more and 25 nm or less, the coverage ratio A of the toner-particle surface with the first inorganic fine particle is 45.0% or more and 70.0% or less.
    Type: Application
    Filed: July 30, 2014
    Publication date: June 9, 2016
    Inventors: Katsuhisa Yamazaki, Koji Nishikawa, Daisuke Yoshiba, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20160139556
    Abstract: Provided are a process cartridge and an image-forming method each of which has a satisfactory cleaning property even at the initial stage of the use of a brand-new process cartridge or electrophotographic apparatus, and hence can suppress a reduction in image quality due to the contamination of a charging member. The charge transporting layer of an electrophotographic photosensitive member contains a specific polyarylate resin or polycarbonate resin, and a toner contains a specific fine particle on the surface of a toner particle.
    Type: Application
    Filed: November 13, 2015
    Publication date: May 19, 2016
    Inventors: Yuki Yamamoto, Atsushi Okuda, Yuka Ishiduka, Shuhei Moribe, Koji Nishikawa
  • Publication number: 20160139522
    Abstract: A toner including a toner particle containing a polyester resin composition, wherein i) the polyester resin composition contains a specific aliphatic hydrocarbon and a polyester resin having at a terminal a structure derived from at least one of a specific alkyl monoalcohol and a specific alkyl monocarboxylic acid, and ii) the total content of the aliphatic hydrocarbon, the structure derived from the alkyl monoalcohol, and the structure derived from the alkyl monocarboxylic acid is 2.5 to 10.0% by mass, wherein, in the temperature-endothermic quantity curve of the polyester resin composition obtained by DSC, an endothermic peak is present in a specific temperature range and an endothermic quantity for this endothermic peak is 0.10 to 1.90 J/g.
    Type: Application
    Filed: November 12, 2015
    Publication date: May 19, 2016
    Inventors: Daisuke Yoshiba, Hiroki Akiyama, Koji Nishikawa, Shotaro Nomura, Katsuhisa Yamazaki
  • Patent number: 9341970
    Abstract: 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: Grant
    Filed: July 29, 2014
    Date of Patent: May 17, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Daisuke Yoshiba, Katsuhisa Yamazaki, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20160111792
    Abstract: The present invention is to provide a thermoplastic resin composition capable of providing a molded article that is excellent in capability of shielding millimeter waves. A thermoplastic resin composition for a molded article having a capability of shielding millimeter waves, containing (A) a thermoplastic resin and (B) carbon long fibers having a fiber length of from 3 to 30 mm in an amount of from 0.5 to 5% by mass. A molded article obtained from the composition is excellent in capability of shielding millimeter waves and can be used as a protective member for a transmitting and receiving antenna of a millimeter wave radar.
    Type: Application
    Filed: April 24, 2014
    Publication date: April 21, 2016
    Inventors: Hiroshi KATAYAMA, Koji NISHIKAWA
  • Publication number: 20160091813
    Abstract: Provided is a toner that uses a crystalline resin, and demonstrates favorable dispersibility of the crystalline resin in the toner, demonstrates superior low-temperature fixability, and is able to inhibit fogging. The toner has a toner particle comprising a resin A, which has a long-chain alkyl group having an average number of carbon atoms of 27 to 50, and a crystalline resin, wherein the SP value (cal/cm3)1/2 of the crystalline resin is 9.00 to 12.00, and in a GC/MS analysis of components that volatize when the toner is heated for 10 minutes at 200° C., the amount of volatile components of saturated hydrocarbons having 30 to 37 carbon atoms is 90 ppm to 260 ppm of toluene equivalent, based on mass.
    Type: Application
    Filed: September 14, 2015
    Publication date: March 31, 2016
    Inventors: Daisuke Yoshiba, Katsuhisa Yamazaki, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20160091809
    Abstract: 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: Application
    Filed: July 30, 2014
    Publication date: March 31, 2016
    Inventors: Shohei Tsuda, Koji Nishikawa, Katsuhisa Yamazaki, Yojiro Hotta, Kazuo Terauchi, Motohide Shiozawa, Takeshi Naka, Takuya Mizuguchi, Takayuki Itakura
  • Publication number: 20160070192
    Abstract: 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: Application
    Filed: July 30, 2014
    Publication date: March 10, 2016
    Inventors: Kazuo Terauchi, Koji Nishikawa, Shohei Tsuda, Yojiro Hotta, Katsuhisa Yamazaki, Takayuki Itakura, Takeshi Naka, Motohide Shiozawa
  • Patent number: 9261804
    Abstract: 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: Grant
    Filed: July 28, 2014
    Date of Patent: February 16, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Katsuhisa Yamazaki, Daisuke Yoshiba, Koji Nishikawa, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto
  • Publication number: 20160041483
    Abstract: 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: Application
    Filed: July 23, 2015
    Publication date: February 11, 2016
    Inventors: Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Hiroki Akiyama, Shohei Tsuda, Daisuke Yoshiba, Katsuhisa Yamazaki
  • Publication number: 20160041484
    Abstract: 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: Application
    Filed: July 29, 2015
    Publication date: February 11, 2016
    Inventors: Shohei Tsuda, Yojiro Hotta, Koji Nishikawa, Masami Fujimoto, Katsuhisa Yamazaki
  • Publication number: 20160041520
    Abstract: 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: Application
    Filed: August 6, 2015
    Publication date: February 11, 2016
    Inventors: Hiroki Akiyama, Koji Nishikawa, Kosuke Fukudome, Shotaro Nomura, Daisuke Yoshiba, Shohei Tsuda, Katsuhisa Yamazaki
  • Publication number: 20160041481
    Abstract: 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: Application
    Filed: July 31, 2015
    Publication date: February 11, 2016
    Inventors: Shotaro Nomura, Koji Nishikawa, Kosuke Fukudome, Daisuke Yoshiba, Shohei Tsuda, Hiroki Akiyama, Katsuhisa Yamazaki
  • Patent number: 9250548
    Abstract: 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: Grant
    Filed: July 24, 2014
    Date of Patent: February 2, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shotaro Nomura, Masami Fujimoto, Katsuhisa Yamazaki, Koji Nishikawa, Daisuke Yoshiba, Hiroki Akiyama
  • Patent number: 9201323
    Abstract: 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: Grant
    Filed: July 25, 2014
    Date of Patent: December 1, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koji Nishikawa, Katsuhisa Yamazaki, Daisuke Yoshiba, Shotaro Nomura, Hiroki Akiyama, Masami Fujimoto