Patents by Inventor Yojiro Hotta

Yojiro Hotta 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: 11360404
    Abstract: A toner comprising a toner particle that contains a binder resin and fine particles A at the surface of the toner particle, wherein the fine particles A are organosilicon polymer fine particles, the organosilicon polymer fine particles have a number-average primary particle diameter of 30 nm to 500 nm, the organosilicon polymer fine particles have an attachment index for a polycarbonate film of not more than 3.5, the organosilicon polymer fine particles penetrate into the toner particle in a penetration depth b (nm), and protrude from the toner particle in a protrusion height c (nm), and b and c satisfy 0.05?b/(b+c)?0.40.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: June 14, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takaaki Furui, Yojiro Hotta, Yasuhiro Hashimoto, Koji Nishikawa, Shotaro Nomura, Yuujirou Nagashima
  • Patent number: 10996577
    Abstract: Toner comprising a toner particle containing binder resin and colorant, wherein fine particles A (organosilicon polymer particles containing an organosilicon polymer) and fine particles B are present at the toner particle surface, the organosilicon polymer has structure in which Si and O are alternately bonded to each other, portion of Si in the organosilicon polymer has R1—SiO3/2 structure, and content of the fine particles A, proportion for area of peak originating with silicon having the structure, volume resistivity of the fine particles B, total coverage ratio of the toner particle surface by the fine particles A embedded in the toner particle (A1) and the fine particles A not embedded in the toner particle (A2), percentage for area occupied by the fine particles A2, content of the fine particles B in the toner, and percentage for area occupied by the fine particles B embedded in the toner particle are prescribed range.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: May 4, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koji Nishikawa, Yojiro Hotta, Yasuhiro Hashimoto, Takaaki Furui, Shotaro Nomura, Yuujirou Nagashima
  • Patent number: 10983450
    Abstract: A toner comprising: a toner particle containing a binder resin; and an external additive, wherein the external additive comprises an external additive A and B; the external additive A has a number-average primary particle diameter of 35 to 300 nm, a dielectric constant ?ra of not more than 3.50, and a shape factor SF-1 of not more than 114, and is an organosilicon polymer particle having a particular T3 unit structure; a proportion for an area of a peak originating from silicon having the T3 unit structure with reference to that of all silicon elements is 0.50 to 1.00; the external additive B has a number-average primary particle diameter of from 5 nm to 25 nm and a dielectric constant ?rb that satisfies formula (A): 0.50??rb??ra (A); and a coverage ratio by the external additive B for the toner particle surface is 50% to 100%.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: April 20, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shotaro Nomura, Yasuhiro Hashimoto, Yojiro Hotta, Koji Nishikawa, Takaaki Furui, Yuujirou Nagashima
  • Patent number: 10983451
    Abstract: A toner comprising an organosilicon polymer particle and a toner particle containing a binder resin and a wax, wherein the organosilicon polymer particle contains an organosilicon polymer, a part of silicon atoms in the organosilicon polymer has a T3 unit structure, a ratio of an area of peaks derived from silicon having the T3 unit structure relative to a total area of peaks derived from all silicon element contained in the organosilicon polymer particle is from 0.70 to 1.00 in 29Si-NMR measurement of the organosilicon polymer particle, a plurality of domains of the wax are present in a cross-section of the toner particle, the wax is an ester wax, the average long diameter of the domains of the ester wax is from 0.03 ?m to 2.00 ?m, and the SP value SPw of the wax is from 8.59 to 9.01.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: April 20, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yasuhiro Hashimoto, Yojiro Hotta, Koji Nishikawa, Takaaki Furui, Shotaro Nomura, Yuujirou Nagashima
  • Patent number: 10747135
    Abstract: A toner including a toner particle; and an external additive, wherein the external additive contains strontium titanate particle, and when in a projected image of the strontium titanate particle photographed using a scanning electron microscope, a standard deviation of a distance from a center of the projected image to an outline of the projected image is Ds, and a circle-equivalent diameter of the projected image is Da, a value CV calculated by Equation (1) is 0.07 or less, CV=Ds/(Da/2)??(1).
    Type: Grant
    Filed: February 26, 2019
    Date of Patent: August 18, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Yojiro Hotta, Koji Nishikawa, Kazuo Terauchi, Takaaki Furui, Ryo Nagata, Keisuke Tanaka, Masami Fujimoto
  • Publication number: 20200209771
    Abstract: A toner comprising an organosilicon polymer particle and a toner particle containing a binder resin and a wax, wherein the organosilicon polymer particle contains an organosilicon polymer, a part of silicon atoms in the organosilicon polymer has a T3 unit structure, a ratio of an area of peaks derived from silicon having the T3 unit structure relative to a total area of peaks derived from all silicon element contained in the organosilicon polymer particle is from 0.70 to 1.00 in 29Si-NMR measurement of the organosilicon polymer particle, a plurality of domains of the wax are present in a cross-section of the toner particle, the wax is an ester wax, the average long diameter of the domains of the ester wax is from 0.03 ?m to 2.00 ?m, and the SP value SPw of the wax is from 8.59 to 9.01.
    Type: Application
    Filed: December 27, 2019
    Publication date: July 2, 2020
    Inventors: Yasuhiro Hashimoto, Yojiro Hotta, Koji Nishikawa, Takaaki Furui, Shotaro Nomura, Yuujirou Nagashima
  • Publication number: 20200209770
    Abstract: Toner comprising a toner particle containing binder resin and colorant, wherein fine particles A (organosilicon polymer particles containing an organosilicon polymer) and fine particles B are present at the toner particle surface, the organosilicon polymer has structure in which Si and O are alternately bonded to each other, portion of Si in the organosilicon polymer has R1—SiO3/2 structure, and content of the fine particles A, proportion for area of peak originating with silicon having the structure, volume resistivity of the fine particles B, total coverage ratio of the toner particle surface by the fine particles A embedded in the toner particle (A1) and the fine particles A not embedded in the toner particle (A2), percentage for area occupied by the fine particles A2, content of the fine particles B in the toner, and percentage for area occupied by the fine particles B embedded in the toner particle are prescribed range.
    Type: Application
    Filed: December 27, 2019
    Publication date: July 2, 2020
    Inventors: Koji Nishikawa, Yojiro Hotta, Yasuhiro Hashimoto, Takaaki Furui, Shotaro Nomura, Yuujirou Nagashima
  • Publication number: 20200209768
    Abstract: A toner comprising a toner particle that contains a binder resin and fine particles A at the surface of the toner particle, wherein the fine particles A are organosilicon polymer fine particles, the organosilicon polymer fine particles have a number-average primary particle diameter of 30 nm to 500 nm, the organosilicon polymer fine particles have an attachment index for a polycarbonate film of not more than 3.5, the organosilicon polymer fine particles penetrate into the toner particle in a penetration depth b (nm), and protrude from the toner particle in a protrusion height c (nm), and b and c satisfy 0.05?b/(b+c)?0.40.
    Type: Application
    Filed: December 27, 2019
    Publication date: July 2, 2020
    Inventors: Takaaki Furui, Yojiro Hotta, Yasuhiro Hashimoto, Koji Nishikawa, Shotaro Nomura, Yuujirou Nagashima
  • Publication number: 20200209769
    Abstract: A toner comprising: a toner particle containing a binder resin; and an external additive, wherein the external additive comprises an external additive A and B; the external additive A has a number-average primary particle diameter of 35 to 300 nm, a dielectric constant ?ra of not more than 3.50, and a shape factor SF-1 of not more than 114, and is an organosilicon polymer particle having a particular T3 unit structure; a proportion for an area of a peak originating from silicon having the T3 unit structure with reference to that of all silicon elements is 0.50 to 1.00; the external additive B has a number-average primary particle diameter of from 5 nm to 25 nm and a dielectric constant ?rb that satisfies formula (A): 0.50??rb??ra (A); and a coverage ratio by the external additive B for the toner particle surface is 50% to 100%.
    Type: Application
    Filed: December 27, 2019
    Publication date: July 2, 2020
    Inventors: Shotaro Nomura, Yasuhiro Hashimoto, Yojiro Hotta, Koji Nishikawa, Takaaki Furui, Yuujirou Nagashima
  • Patent number: 10488777
    Abstract: A toner contains toner particles, titanate fine particles having a Group II element, and hydrotalcite compound fine particles as an external additive and satisfying 10?Lt?80 and 100?Lh?Weight average particle diameter (D4) of toner particles×0.50, when the number average particle diameter (D1) of primary particles of the titanate fine particles is defined as Lt (nm) and the number average particle diameter (D1) of primary particles of the hydrotalcite compound fine particles is defined as Lh (nm).
    Type: Grant
    Filed: August 23, 2018
    Date of Patent: November 26, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuo Terauchi, Yojiro Hotta, Koji Nishikawa, Masami Fujimoto, Takaaki Furui, Ryo Nagata, Keisuke Tanaka
  • Patent number: 10409186
    Abstract: 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: Grant
    Filed: July 30, 2014
    Date of Patent: September 10, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yojiro Hotta, Shohei Tsuda, Taiji Katsura, Masaharu Miura, Yoshinobu Baba, Takayuki Itakura
  • Publication number: 20190271928
    Abstract: A toner including a toner particle; and an external additive, wherein the external additive contains strontium titanate particle, and when in a projected image of the strontium titanate particle photographed using a scanning electron microscope, a standard deviation of a distance from a center of the projected image to an outline of the projected image is Ds, and a circle-equivalent diameter of the projected image is Da, a value CV calculated by Equation (1) is 0.07 or less, CV=Ds/(Da/2)??(1).
    Type: Application
    Filed: February 26, 2019
    Publication date: September 5, 2019
    Inventors: Yojiro Hotta, Koji Nishikawa, Kazuo Terauchi, Takaaki Furui, Ryo Nagata, Keisuke Tanaka, Masami Fujimoto
  • Patent number: 10303075
    Abstract: A toner including a toner particle and an external additive, wherein the external additive contains an inorganic fine particle A and a silica fine particle; in a surface of the toner observed using a scanning electron microscope, a number-average particle diameter of primary particle of the silica fine particle is from 5 nm to 50 nm, a number-average particle diameter of primary particle of the inorganic fine particle A is at least 10 nm and less than 60 nm, a coverage ratio X1 of the toner surface covered by the silica fine particle is from 60 area % to 95 area %, the inorganic fine particle A is a fine particle of a titanate having a Group 2 element, and a coverage ratio X2 of the toner surface covered by the inorganic fine particle A is from 5 area % to 40 area %.
    Type: Grant
    Filed: February 23, 2018
    Date of Patent: May 28, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Keisuke Tanaka, Yojiro Hotta, Kazuo Terauchi, Koji Nishikawa, Takaaki Furui, Ryo Nagata, Kazuyuki Sato, Yu Yoshida, Yusuke Kosaki, Masami Fujimoto
  • Patent number: 10295920
    Abstract: Provided is toner that contains a toner particle, and an external additive containing a strontium titanate particle, wherein the toner has an average circularity of at least 0.935 and not more than 0.995, the strontium titanate particle has a number-average primary particle diameter of at least 10 nm and not more than 60 nm, the strontium titanate particle has a peak in the range of 39.700°±0.150° and a peak in the range of 46.200°±0.150° in a CuK? x-ray diffraction spectrum obtained in the 2? range of at least 10° and not more than 90° where ? is the Bragg angle, and the ratio of the area Sb of the peak at 46.200°±0.150° to the area Sa of the peak at 39.700°±0.150° is at least 1.80 and not more than 2.30.
    Type: Grant
    Filed: February 21, 2018
    Date of Patent: May 21, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koji Nishikawa, Yojiro Hotta, Kazuo Terauchi, Takaaki Furui, Ryo Nagata, Keisuke Tanaka, Kazuyuki Sato, Yu Yoshida, Yusuke Kosaki, Masami Fujimoto
  • Patent number: 10228630
    Abstract: A toner comprising an external additive A, and a toner particle containing a binder resin and a colorant, wherein the external additive A: i) is an external additive that has a charge control agent on the surface thereof; ii) has a wall friction angle ? calculated from the following formula (1) of not more than 25.0° ?=?/5.0??formula (1); iii) has a number-average particle diameter (D1) of primary particles of at least 70 nm and not more than 500 nm; and iv) has a solidity as given by the following formula (2) of at least 0.40 and not more than 0.90 solidity=area of external additive A/area of region encompassed by envelope for external additive A?? formula (2).
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: March 12, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takuya Mizuguchi, Kazuo Terauchi, Yojiro Hotta, Takeshi Naka, Motohide Shiozawa, Masami Fujimoto
  • Publication number: 20190064686
    Abstract: A toner contains toner particles, titanate fine particles having a Group II element, and hydrotalcite compound fine particles as an external additive and satisfying 10?Lt?80 and 100?Lh?Weight average particle diameter (D4) of toner particles×0.50, when the number average particle diameter (D1) of primary particles of the titanate fine particles is defined as Lt (nm) and the number average particle diameter (D1) of primary particles of the hydrotalcite compound fine particles is defined as Lh (nm).
    Type: Application
    Filed: August 23, 2018
    Publication date: February 28, 2019
    Inventors: Kazuo Terauchi, Yojiro Hotta, Koji Nishikawa, Masami Fujimoto, Takaaki Furui, Ryo Nagata, Keisuke Tanaka
  • Patent number: 10101683
    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: Grant
    Filed: December 18, 2015
    Date of Patent: October 16, 2018
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koji Nishikawa, Shuhei Moribe, Daisuke Yoshiba, Shotaro Nomura, Kosuke Fukudome, Hiroki Akiyama, Yojiro Hotta, Katsuhisa Yamazaki
  • Publication number: 20180246432
    Abstract: Provided is toner that contains a toner particle, and an external additive containing a strontium titanate particle, wherein the toner has an average circularity of at least 0.935 and not more than 0.995, the strontium titanate particle has a number-average primary particle diameter of at least 10 nm and not more than 60 nm, the strontium titanate particle has a peak in the range of 39.700°±0.150° and a peak in the range of 46.200°±0.150° in a CuK? x-ray diffraction spectrum obtained in the 2? range of at least 10° and not more than 90° where ? is the Bragg angle, and the ratio of the area Sb of the peak at 46.200°±0.150° to the area Sa of the peak at 39.700°±0.150° is at least 1.80 and not more than 2.30.
    Type: Application
    Filed: February 21, 2018
    Publication date: August 30, 2018
    Inventors: Koji Nishikawa, Yojiro Hotta, Kazuo Terauchi, Takaaki Furui, Ryo Nagata, Keisuke Tanaka, Kazuyuki Sato, Yu Yoshida, Yusuke Kosaki, Masami Fujimoto
  • Publication number: 20180246430
    Abstract: A toner including a toner particle and an external additive, wherein the external additive contains an inorganic fine particle A and a silica fine particle; in a surface of the toner observed using a scanning electron microscope, a number-average particle diameter of primary particle of the silica fine particle is from 5 nm to 50 nm, a number-average particle diameter of primary particle of the inorganic fine particle A is at least 10 nm and less than 60 nm, a coverage ratio X1 of the toner surface covered by the silica fine particle is from 60 area % to 95 area %, the inorganic fine particle A is a fine particle of a titanate having a Group 2 element, and a coverage ratio X2 of the toner surface covered by the inorganic fine particle A is from 5 area % to 40 area %.
    Type: Application
    Filed: February 23, 2018
    Publication date: August 30, 2018
    Inventors: Keisuke Tanaka, Yojiro Hotta, Kazuo Terauchi, Koji Nishikawa, Takaaki Furui, Ryo Nagata, Kazuyuki Sato, Yu Yoshida, Yusuke Kosaki, Masami Fujimoto
  • Publication number: 20180074425
    Abstract: A toner comprising an external additive A, and a toner particle containing a binder resin and a colorant, wherein the external additive A: i) is an external additive that has a charge control agent on the surface thereof; ii) has a wall friction angle ? calculated from the following formula (1) of not more than 25.0° ?=?/5.0??formula (1); iii) has a number-average particle diameter (D1) of primary particles of at least 70 nm and not more than 500 nm; and iv) has a solidity as given by the following formula (2) of at least 0.40 and not more than 0.90 solidity=area of external additive A/area of region encompassed by envelope for external additive A?? formula (2).
    Type: Application
    Filed: September 7, 2017
    Publication date: March 15, 2018
    Inventors: Takuya Mizuguchi, Kazuo Terauchi, Yojiro Hotta, Takeshi Naka, Motohide Shiozawa, Masami Fujimoto