Patents by Inventor Kentaro Kamae

Kentaro Kamae 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: 8986914
    Abstract: An object of the present invention is to improve resistance to wraparound during fixing while achieving both low-temperature fixability and resistance to hot offset. A further object is to suppress image density variations and fogging in white background regions during use at high print coverage rate at high temperature and high humidity. A toner containing inorganic fine particles and toner particles containing a binder resin and a wax being provided, the toner being characterized in that the binder resin contains a polyester resin A obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aromatic diol and a polyester resin B obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aliphatic diol, and in that the degree of segregation of the wax in the toner depth direction from the toner surface toward the toner center is controlled.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: March 24, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Yoshiaki Shiotari, Koh Ishigami, Kentaro Kamae, Takayuki Itakura
  • Patent number: 8974994
    Abstract: Provided is a magnetic carrier satisfactory in terms of the suppression of leakage and solid carrier adhesion, charge-providing performance, and developability. The magnetic carrier is a magnetic carrier, including filled core particles of which pores of porous magnetic core particles are filled with a filling resin composition, and having a surface coated with a coating resin composition, in which the coating resin composition comprises a coating resin and a carbon black, an amount of the coating resin composition is 2.0 parts by mass or more and 5.0 parts by mass or less with respect to 100.0 parts by mass of the filled core particles; and a particle diameter of the carbon black in the coating resin composition Pv at a maximum frequency in a particle size distribution based on a volume of the carbon black is 1.0 ?m or more and 10.0 ?m or less.
    Type: Grant
    Filed: January 28, 2013
    Date of Patent: March 10, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kentaro Kamae, Koh Ishigami, Yoshinobu Baba
  • Patent number: 8927188
    Abstract: A method of producing a magnetic carrier, having a coating process step in which a surface of a magnetic carrier core is coated with particles of a resin composition by a mechanical impact force. The coating process step has a first coating process step of mixing, dispersing, and fixing the particles on the surface of the core, and a second coating process step, which is performed after the first coating process step, of carrying out a film-forming coating process on the particles. In the first and second coating process steps, the peripheral velocity of the outermost end of stirring members, the coating process time, the product temperature at the end of the coating process, and the glass-transition temperature of the resin component satisfy specific relationships.
    Type: Grant
    Filed: July 26, 2013
    Date of Patent: January 6, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Naka, Masayuki Hama, Kentaro Kamae, Koh Ishigami, Yoshinobu Baba, Hiroaki Kawakami, Yojiro Hotta, Satoshi Mita
  • Patent number: 8921023
    Abstract: Provided is a magnetic carrier excellent in leakage, uniformity of a solid image having satisfactory charging stability and developing performance at low electric field. The magnetic carrier is a magnetic carrier comprising: a magnetic substance-dispersed resin carrier core, which contains a magnetic substance and a binding resin, and a coating resin on a surface thereof, wherein: the carrier core has resistivity at 1000 V/cm of 5.0×106-8.0×107 ?·cm, the magnetic substance has a number average particle diameter of 0.20-0.35 ?m; and comprises magnetic-substance particles having vertexes and a particle diameter of 0.53 ?m or more in an amount of 10.0-32.0 vol % based on a total amount of the magnetic substance; and wherein: the carrier core has Fe2O3 content of 98.00% by mass or more; and ZnO content of 0.06-0.50% by mass.
    Type: Grant
    Filed: August 7, 2013
    Date of Patent: December 30, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshinobu Baba, Koh Ishigami, Masayuki Hama, Kentaro Kamae, Hiroaki Kawakami
  • Publication number: 20140220487
    Abstract: A magnetic carrier is provided which can suppress a decrease in glossiness even in a long term use for POD which requires high glossiness. A magnetic carrier includes a filled core particle in which a silicone resin is filled in pores of a porous magnetic core particle and a vinyl resin coating a surface of the filled core particle. In a pore distribution of the porous magnetic core particle measured by a mercury intrusion method, a cumulative pore volume in a pore diameter range of 0.1 to 3.0 ?m is 35.0 to 95.0 mm3/g, and in a pore distribution of the filled core particle measured by a mercury intrusion method, a cumulative pore volume in a pore diameter range of 0.1 to 3.0 ?m is 3.0 to 15.0 mm3/g. The magnetic carrier includes 1.2 to 3.0 parts by mass of the vinyl resin to 100.0 parts by mass of the filled core particle.
    Type: Application
    Filed: June 21, 2012
    Publication date: August 7, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kentaro Kamae, Nozomu Komatsu, Koh Ishigami, Yoshinobu Baba
  • Publication number: 20140134535
    Abstract: Provided is a magnetic carrier satisfying leakage, white spots, charging property and high developing performance in a low electric field and having excellent durability. The magnetic carrier is a magnetic carrier comprising a magnetic substance-dispersed resin carrier core containing a magnetic substance and a binder resin, and a coating resin on a surface thereof, wherein the magnetic substance comprises a magnetic substance A having a shape without vertexes and a magnetic substance B having a shape with vertexes, the magnetic substance B has a number average particle diameter of 0.40-2.00 ?m, and in a reflection electron image of a section of the magnetic substance-dispersed resin carrier core taken by a scanning electron microscope, an area proportion of the magnetic substance B is larger than an area proportion of the magnetic substance A within a region from the surface of the magnetic substance-dispersed resin carrier core to a depth of 1.0 ?m.
    Type: Application
    Filed: January 17, 2014
    Publication date: May 15, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yoshinobu Baba, Koh Ishigami, Masayuki Hama, Kentaro Kamae, Hiroaki Kawakami
  • Publication number: 20140113228
    Abstract: A toner has a weight-average particle diameter (D4) of 3.0 ?m or more and 8.0 ?m or less, wherein the average circularity analyzed by dividing particles of the toner having an equivalent circle diameter of 1.98 ?m or more and less than 200.00 ?m into 800 in a range of a circularity of 0.200 or more and 1.000 or less is 0.960 or more and 0.985 or less, the proportion of particles A having a circularity of 0.990 or more and 1.000 or less is 25.0% or less on a basis of the number of particles, and the ratio of particles B having an equivalent circle diameter of 0.50 ?m or more and less than 1.98 ?m to the total particles having an equivalent circle diameter of 0.50 ?m or more and less than 200.00 ?m is 10.0% or less on a basis of the number of particles.
    Type: Application
    Filed: May 30, 2012
    Publication date: April 24, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yoshiaki Shiotari, Kosuke Fukudome, Nozomu Komatsu, Kunihiko Nakamura, Kentaro Kamae, Hiroyuki Fujikawa, Koh Ishigami, Takayuki Itakura
  • Publication number: 20140045115
    Abstract: Provided is a magnetic carrier excellent in leakage, uniformity of a solid image having satisfactory charging stability and developing performance at low electric field. The magnetic carrier is a magnetic carrier comprising: a magnetic substance-dispersed resin carrier core, which contains a magnetic substance and a binding resin, and a coating resin on a surface thereof, wherein: the carrier core has resistivity at 1000 V/cm of 5.0×106-8.0×107 ?·cm, the magnetic substance has a number average particle diameter of 0.20-0.35 ?m; and comprises magnetic-substance particles having vertexes and a particle diameter of 0.53 ?m or more in an amount of 10.0-32.0 vol % based on a total amount of the magnetic substance; and wherein: the carrier core has Fe2O3 content of 98.00% by mass or more; and ZnO content of 0.06-0.50% by mass.
    Type: Application
    Filed: August 7, 2013
    Publication date: February 13, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yoshinobu Baba, Koh Ishigami, Masayuki Hama, Kentaro Kamae, Hiroaki Kawakami
  • Publication number: 20140038098
    Abstract: A method of producing a magnetic carrier, having a coating process step in which a surface of a magnetic carrier core is coated with particles of a resin composition by a mechanical impact force. The coating process step has a first coating process step of mixing, dispersing, and fixing the particles on the surface of the core, and a second coating process step, which is performed after the first coating process step, of carrying out a film-forming coating process on the particles. In the first and second coating process steps, the peripheral velocity of the outermost end of stirring members, the coating process time, the product temperature at the end of the coating process, and the glass-transition temperature of the resin component satisfy specific relationships.
    Type: Application
    Filed: July 26, 2013
    Publication date: February 6, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takeshi Naka, Masayuki Hama, Kentaro Kamae, Koh Ishigami, Yoshinobu Baba, Hiroaki Kawakami, Yojiro Hotta, Satoshi Mita
  • Publication number: 20140030650
    Abstract: A magnetic carrier having a resin-containing ferrite particles each containing a porous ferrite core and a resin in pores of the porous ferrite core, wherein the porous ferrite core has a particular pore diameter corresponding to the maximum logarithmic differential pore volume in a pore diameter range from at least 0.10 ?m to not more than 3.00 ?m, the resistivity of the porous ferrite core is in a particular range, and the porous ferrite core contains an oxide of Mg in a particular amount and contains a particular amount of a oxide of at least one metal selected from the group consisting of Mn, Sr, and Ca.
    Type: Application
    Filed: May 24, 2013
    Publication date: January 30, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Nozomu Komatsu, Kentaro Kamae, Koh Ishigami, Yoshinobu Baba
  • Publication number: 20130316282
    Abstract: The present invention provides a magnetic carrier that can stably impart charge to a toner on a long term basis and that exhibits an excellent toner separation property and thus exhibits an excellent developing performance. This magnetic carrier is a magnetic carrier in which a vinyl resin coats the surface of a resin-filled core in which a resin is filled in pores of a porous ferrite particle, wherein the resistivity, Mg content, and total content of Sr and Ca oxides of the porous ferrite particle exhibit prescribed values and the magnetic carrier has a total area—in the backscattered electron projection image obtained by observation using a scanning electron microscope at an acceleration voltage of 2.0 kV—for a region originating with the porous ferrite particle of from at least 0.2 area % to not more than 5.0 area % with reference to the projected area of the magnetic carrier.
    Type: Application
    Filed: May 23, 2013
    Publication date: November 28, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Koh Ishigami, Kentaro Kamae, Nozomu Komatsu, Yoshinobu Baba
  • Publication number: 20130244159
    Abstract: Provided is a two-component developer having excellent developing performance and little change in image concentration, and achieving long-term suppression of image defects such as transfer failure and fogging. Provided is a two-component developer containing a magnetic carrier and a toner, wherein the magnetic carrier has magnetic carrier particles comprising a silicone resin B coated on the surfaces of filled core particles in which pores of porous magnetic core particles are filled with a silicone resin A, the silicone resin A is a silicone resin cured in the presence of a non-metal catalyst or without a catalyst, while the silicone resin B is a silicone resin cured in the presence of a metal catalyst having titanium or zirconium, and the toner contains a binder resin, a release agent and a colorant, and has an average circularity of 0.940 or more.
    Type: Application
    Filed: November 24, 2011
    Publication date: September 19, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Koh Ishigami, Nozomu Komatsu, Kentaro Kamae, Yoshinobu Baba
  • Publication number: 20130236830
    Abstract: It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. A toner characterized in that the average circularity of the above-described toner is 0.960 or more, and 0.985 or less, where the average circularity is analyzed by dividing particles having a circle equivalent diameter of 1.98 ?m or more, and 200.00 ?m or less, the number A of toners having a circularity of 0.990 or more, and 1.000 or less is 25.0 percent by the number or less, and the percentage of the number of particles B having a circle equivalent diameter of 0.50 ?m or more, and 1.98 ?m or less relative to the total particles of 0.50 ?m or more, and 200.00 ?m or less is 10.0 percent by the number or less.
    Type: Application
    Filed: April 30, 2013
    Publication date: September 12, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yoshiaki Shiotari, Kosuke Fukudome, Nozomu Komatsu, Kunihiko Nakamura, Kentaro Kamae, Hiroyuki Fujikawa, Koh Ishigami, Takayuki Itakura, Hironori Minagawa
  • Publication number: 20130171556
    Abstract: An object of the present invention is to improve resistance to wraparound during fixing while achieving both low-temperature fixability and resistance to hot offset. A further object is to suppress image density variations and fogging in white background regions during use at high print coverage rate at high temperature and high humidity. A toner containing inorganic fine particles and toner particles containing a binder resin and a wax being provided, the toner being characterized in that the binder resin contains a polyester resin A obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aromatic diol and a polyester resin B obtained by condensation polymerization of a polyvalent carboxylic acid and an alcohol component mainly containing an aliphatic diol, and in that the degree of segregation of the wax in the toner depth direction from the toner surface toward the toner center is controlled.
    Type: Application
    Filed: September 15, 2011
    Publication date: July 4, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroyuki Fujikawa, Kunihiko Nakamura, Nozomu Komatsu, Yoshiaki Shiotari, Koh Ishigami, Kentaro Kamae, Takayuki Itakura
  • Patent number: 8455167
    Abstract: It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. A toner characterized in that the average circularity of the above-described toner is 0.960 or more, and 0.985 or less, where the average circularity is analyzed by dividing particles having a circle equivalent diameter of 1.98 ?m or more, and 200.00 ?m or less, the number A of toners having a circularity of 0.990 or more, and 1.000 or less is 25.0 percent by the number or less, and the percentage of the number of particles B having a circle equivalent diameter of 0.50 ?m or more, and 1.98 ?m or less relative to the total particles of 0.50 ?m or more, and 200.00 ?m or less is 10.0 percent by the number or less.
    Type: Grant
    Filed: December 10, 2010
    Date of Patent: June 4, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshiaki Shiotari, Kosuke Fukudome, Nozomu Komatsu, Kunihiko Nakamura, Kentaro Kamae, Hiroyuki Fujikawa, Koh Ishigami, Takayuki Itakura, Hironori Minagawa
  • Patent number: 8323726
    Abstract: When a surface of magnetic carrier core particles is coated with coating resin composition particles, the coating is conducted so that a surface of the magnetic carrier is free from cracks and chips and has fewer residual resin composition particles and a coating is uniform. In the method, a rotor having a plurality of stirring members on a surface thereof is rotated to coat the surface of magnetic carrier core particles with the resin composition particles. When the coating is conducted, while repeatedly conducting transportation in a direction of a driver and transportation in an anti-driver direction, the surface of the magnetic carrier core particles is coated with the resin composition. The resin composition particles has a 50% particle diameter (D50) based on volume of 0.2 ?m or more to 6.0 ?m or less and the proportion of particles of 10.0 ?m or more is 2.0% by volume or less.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: December 4, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Naka, Yoshinobu Baba, Koh Ishigami, Yoshiaki Shiotari, Kentaro Kamae
  • Publication number: 20110143277
    Abstract: It is an object of the present invention to provide a toner having the transfer efficiency and the cleanability in combination, exhibiting excellent stress resistance, and ensuring the low-temperature fixing. A toner characterized in that the average circularity of the above-described toner is 0.960 or more, and 0.985 or less, where the average circularity is analyzed by dividing particles having a circle equivalent diameter of 1.98 ?m or more, and 200.00 ?m or less, the number A of toners having a circularity of 0.990 or more, and 1.000 or less is 25.0 percent by the number or less, and the percentage of the number of particles B having a circle equivalent diameter of 0.50 ?m or more, and 1.98 ?m or less relative to the total particles of 0.50 ?m or more, and 200.00 ?m or less is 10.0 percent by the number or less.
    Type: Application
    Filed: December 10, 2010
    Publication date: June 16, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yoshiaki Shiotari, Kosuke Fukudome, Nozomu Komatsu, Kunihiko Nakamura, Kentaro Kamae, Hiroyuki Fujikawa, Koh Ishigami, Takayuki Itakura, Hironori Minagawa
  • Publication number: 20110024669
    Abstract: When a surface of magnetic carrier core particles is coated with coating resin composition particles, the coating is conducted so that a surface of the magnetic carrier is free from cracks and chips and has fewer residual resin composition particles and a coating is uniform. In the method, a rotor having a plurality of stirring members on a surface thereof is rotated to coat the surface of magnetic carrier core particles with the resin composition particles. When the coating is conducted, while repeatedly conducting transportation in a direction of a driver and transportation in an anti-driver direction, the surface of the magnetic carrier core particles is coated with the resin composition. The resin composition particles has a 50% particle diameter (D50) based on volume of 0.2 ?m or more to 6.0 ?m or less and the proportion of particles of 10.0 ?m or more is 2.0% by volume or less.
    Type: Application
    Filed: October 7, 2010
    Publication date: February 3, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takeshi Naka, Yoshinobu Baba, Koh Ishigami, Yoshiaki Shiotari, Kentaro Kamae