Patents by Inventor Takuma Ikejiri

Takuma Ikejiri 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: 10545420
    Abstract: A magnetic toner is provided, which has a magnetic toner particle containing a binder resin, a wax, and a magnetic body, wherein, when Dn is a number-average particle diameter of the toner, CV1 is coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn ?0.500 to +0.500, and CV2 is coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn ?1.500 to ?0.500, a relationship CV2/CV1?1.00 is satisfied; an average brightness of the toner in the range of Dn ?0.500 to +0.500 is 30.0 to 60.0; and when, in a cross section of the toner observed using a transmission electron microscope, which is divided with a square grid having a side of 0.8 ?m, coefficient of variation CV3 of an occupied area percentage for the magnetic body is 40.0 to 80.0%.
    Type: Grant
    Filed: June 26, 2018
    Date of Patent: January 28, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tetsuya Kinumatsu, Yusuke Hasegawa, Kosuke Fukudome, Tomohisa Sano, Kenji Ookubo, Yoshitaka Suzumura, Takuma Ikejiri
  • Publication number: 20190011846
    Abstract: A magnetic toner is provided, which has a magnetic toner particle containing a binder resin, a wax, and a magnetic body, wherein, when Dn is a number-average particle diameter of the toner, CV1 is coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn?0.500 to +0.500, and CV2 is coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn?1.500 to ?0.500, a relationship CV2/CV1 1.00 is satisfied; an average brightness of the toner in the range of Dn?0.500 to +0.500 is 30.0 to 60.0; and when, in a cross section of the toner observed using a transmission electron microscope, which is divided with a square grid having a side of 0.8 ?m, coefficient of variation CV3 of an occupied area percentage for the magnetic body is 40.0 to 80.0%.
    Type: Application
    Filed: June 26, 2018
    Publication date: January 10, 2019
    Inventors: TETSUYA KINUMATSU, Yusuke Hasegawa, Kasuke Fukudome, Tomohisa Sano, Kenji Ookubo, Yoshitaka Suzumura, Takuma Ikejiri
  • Patent number: 10012923
    Abstract: Provided is a toner including toner particles, each of which contains a binder resin, a colorant, a releasing agent and a crystalline polyester, wherein in an observation of a cross-section each of the toner particles by transmission electron microscopy, specific toner particles each of which has domains of the crystalline polyester and domains of the releasing agent, are present at a ratio of at least 70% by number of the toner particles in the toner, an arithmetic mean of maximum diameters of the domains of the releasing agent is within prescribed range, and the specific toner particles satisfy prescribed conditions.
    Type: Grant
    Filed: April 18, 2017
    Date of Patent: July 3, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tomohisa Sano, Yusuke Hasegawa, Yoshitaka Suzumura, Satoshi Arimura, Takuma Ikejiri
  • Patent number: 9964881
    Abstract: A toner comprising toner particles, each of which contains a binder resin and a colorant, wherein an onset temperature Te (° C.) of a storage elastic modulus E? obtained in a powder dynamic viscoelastic measurement on the toner is at least 50° C. and not more than 70° C., and a value at Te (° C.) of a storage elastic modulus G? obtained in a pellet dynamic viscoelastic measurement on the toner is at least 4.0×107 Pa and not more than 1.0×1010 Pa.
    Type: Grant
    Filed: May 16, 2017
    Date of Patent: May 8, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takuma Ikejiri, Yusuke Hasegawa, Tomohisa Sano, Yoshitaka Suzumura, Shohei Yamashita
  • Patent number: 9946179
    Abstract: A toner comprising a binder resin, a crystalline material, and a colorant, wherein, in a cross section image of the toner, when R (?m) is a long axis of the toner, r (?m) is a long axis of a crystalline material domain, domain A is a domain satisfying formula (ii), and domain B is a domain satisfying formula (iii), the toner in which the domain A and the domain B are both present is at least 50 number %; an number average diameter RAvg of the long axis of the toner satisfies formula (i); and a number of domain B per toner cross section of one toner is 20 to 300. 4 ?m?RAvg?12 ?m??(i) 0.125?r/R?0.375??(ii) 0.000625?r/R?0.
    Type: Grant
    Filed: November 29, 2016
    Date of Patent: April 17, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Satoshi Arimura, Yusuke Hasegawa, Tomohisa Sano, Yoshitaka Suzumura, Takuma Ikejiri
  • Patent number: 9946181
    Abstract: A toner comprises toner particles, each of which contains a binder resin, a colorant, a wax and a crystalline polyester. The melting point P(t) of the crystalline polyester is at least 65.0° C. and not more than 80.0° C., and regarding a storage elastic modulus G? obtained in dynamic viscoelasticity measurement of the toner, where G? at 50° C. is denoted by G?(50), G? at 80° C. is denoted by G?(80), G? at 120° C. is denoted by G?(120), and G? at the melting point P(t) of the crystalline polyester is denoted by G?(t), the following formulas are satisfied: 4.2×108 Pa?G?(50), 3.0×102?G?(50)/G?(80), and G?(t)/G?(120)?7.0×102.
    Type: Grant
    Filed: May 4, 2017
    Date of Patent: April 17, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yusuke Hasegawa, Tomohisa Sano, Yoshitaka Suzumura, Takuma Ikejiri, Shohei Yamashita
  • Patent number: 9927728
    Abstract: Provided is a method for producing a toner particle including a step of condensing a raw slurry by using a decanter-type centrifugal separator, in an aqueous medium. The step of condensing the raw slurry is carried out under following conditions: a centrifugal force is at least 500 G and less than 4000 G and a temperature is at least Tg?10° C. and not more than Tg+10° C. And a ratio of a colored particles in condensed slurry is within a prescribed range.
    Type: Grant
    Filed: March 23, 2017
    Date of Patent: March 27, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Satoshi Arimura, Yusuke Hasegawa, Tomohisa Sano, Yoshitaka Suzumura, Takuma Ikejiri, Shohei Yamashita
  • Publication number: 20170336726
    Abstract: A toner comprises toner particles, each of which contains a binder resin, a colorant, a wax and a crystalline polyester. The melting point P(t) of the crystalline polyester is at least 65.0° C. and not more than 80.0° C., and regarding a storage elastic modulus G? obtained in dynamic viscoelasticity measurement of the toner, where G? at 50° C. is denoted by G?(50), G? at 80° C. is denoted by G?(80), G? at 120° C. is denoted by G?(120), and G? at the melting point P(t) of the crystalline polyester is denoted by G?(t), the following formulas are satisfied: 4.2×108 Pa?G?(50), 3.0×102?G?(50)/G?(80), and G?(t)/G?(120)?7.0×102.
    Type: Application
    Filed: May 4, 2017
    Publication date: November 23, 2017
    Inventors: Yusuke Hasegawa, Tomohisa Sano, Yoshitaka Suzumura, Takuma Ikejiri, Shohei Yamashita
  • Publication number: 20170336727
    Abstract: A toner comprising toner particles, each of which contains a binder resin and a colorant, wherein an onset temperature Te (° C.) of a storage elastic modulus E? obtained in a powder dynamic viscoelastic measurement on the toner is at least 50° C. and not more than 70° C., and a value at Te (° C.) of a storage elastic modulus G? obtained in a pellet dynamic viscoelastic measurement on the toner is at least 4.0×107 Pa and not more than 1.0×1010 Pa.
    Type: Application
    Filed: May 16, 2017
    Publication date: November 23, 2017
    Inventors: Takuma Ikejiri, Yusuke Hasegawa, Tomohisa Sano, Yoshitaka Suzumura, Shohei Yamashita
  • Patent number: 9804519
    Abstract: A method for producing a toner containing a toner particle containing a binder resin, a colorant and a crystalline substance, wherein the method includes the steps of: (I) setting a temperature of a dispersion, in which a coloring particle is dispersed with an aqueous medium, to TA(° C.), which is higher than the higher of a crystallization temperature Tc(° C.) of the crystalline substance and a glass transition temperature Tg(° C.) of the coloring particle, the coloring particle containing the binder resin, the colorant and the crystalline substance; (II) cooling the dispersion from the TA to a temperature equal to or lower than the Tg at a cooling rate of at least 5.0° C./min after the step (I); and (III) holding the dispersion in a temperature from Tg?10 to Tg+10 for at least 30 min after the step (II).
    Type: Grant
    Filed: December 1, 2016
    Date of Patent: October 31, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshitaka Suzumura, Yusuke Hasegawa, Tomohisa Sano, Satoshi Arimura, Takuma Ikejiri
  • Publication number: 20170307993
    Abstract: Provided is a toner including toner particles, each of which contains a binder resin, a colorant, a releasing agent and a crystalline polyester, wherein in an observation of a cross-section each of the toner particles by transmission electron microscopy, specific toner particles each of which has domains of the crystalline polyester and domains of the releasing agent, are present at a ratio of at least 70% by number of the toner particles in the toner, an arithmetic mean of maximum diameters of the domains of the releasing agent is within prescribed range, and the specific toner particles satisfy prescribed conditions.
    Type: Application
    Filed: April 18, 2017
    Publication date: October 26, 2017
    Inventors: Tomohisa Sano, Yusuke Hasegawa, Yoshitaka Suzumura, Satoshi Arimura, Takuma Ikejiri
  • Publication number: 20170277051
    Abstract: Provided is a method for producing a toner particle including a step of condensing a raw slurry by using a decanter-type centrifugal separator, in an aqueous medium. The step of condensing the raw slurry is carried out under following conditions: a centrifugal force is at least 500 G and less than 4000 G and a temperature is at least Tg?10° C. and not more than Tg+10° C. And a ratio of a colored particles in condensed slurry is within a prescribed range.
    Type: Application
    Filed: March 23, 2017
    Publication date: September 28, 2017
    Inventors: Satoshi Arimura, Yusuke Hasegawa, Tomohisa Sano, Yoshitaka Suzumura, Takuma Ikejiri, Shohei Yamashita
  • Publication number: 20170160663
    Abstract: A toner comprising a binder resin, a crystalline material, and a colorant, wherein, in a cross section image of the toner, when R (?m) is a long axis of the toner, r (?m) is a long axis of a crystalline material domain, domain A is a domain satisfying formula (ii), and domain B is a domain satisfying formula (iii), the toner in which the domain A and the domain B are both present is at least 50 number %; an number average diameter RAvg of the long axis of the toner satisfies formula (i); and a number of domain B per toner cross section of one toner is 20 to 300. 4 ?m?RAvg?12 ?m??(i) 0.125?r/R?0.375??(ii) 0.000625?e r/R?0.
    Type: Application
    Filed: November 29, 2016
    Publication date: June 8, 2017
    Inventors: Satoshi Arimura, Yusuke Hasegawa, Tomohisa Sano, Yoshitaka Suzumura, Takuma Ikejiri
  • Publication number: 20170160656
    Abstract: A method for producing a toner containing a toner particle containing a binder resin, a colorant and a crystalline substance, wherein the method includes the steps of: (I) setting a temperature of a dispersion, in which a coloring particle is dispersed with an aqueous medium, to TA(° C.), which is higher than the higher of a crystallization temperature Tc(° C.) of the crystalline substance and a glass transition temperature Tg(° C.) of the coloring particle, the coloring particle containing the binder resin, the colorant and the crystalline substance; (II) cooling the dispersion from the TA to a temperature equal to or lower than the Tg at a cooling rate of at least 5.0° C./min after the step (I); and (III) holding the dispersion in a temperature from Tg?10 to Tg+10 for at least 30 min after the step (II).
    Type: Application
    Filed: December 1, 2016
    Publication date: June 8, 2017
    Inventors: Yoshitaka Suzumura, Yusuke Hasegawa, Tomohisa Sano, Satoshi Arimura, Takuma Ikejiri