Patents by Inventor Hiroki Sawamoto

Hiroki Sawamoto 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).

  • Publication number: 20230125587
    Abstract: A zinc foil has a zinc crystal grain size of 0.2 ?m or more and 50 ?m or less. The zinc foil preferably includes: a base metal containing zinc; and a metal element other than zinc. The metal element preferably includes at least one selected from the group consisting of bismuth, indium, magnesium, calcium, gallium, tin, barium, strontium, silver, and manganese. It is also preferable that the content of the metal element is 10 ppm or more and 10000 ppm or less in terms of mass. It is also preferable that the zinc foil has an apparent density of 3 g/cm3 or more and 7 g/cm3 or less. The apparent density is based on contour measurement.
    Type: Application
    Filed: January 22, 2021
    Publication date: April 27, 2023
    Inventors: Hiroki SAWAMOTO, Hidetoshi INOUE, Masatsugu MATSUFUJI, Takamasa KABASHIMA
  • Patent number: 11422480
    Abstract: The present invention provides: a ferrite carrier core material for an electrophotographic developer, the material having a mesh passing amount of 3 wt % or less as indicated by the ratio of the weight of particles passing through a 16 ?m-mesh to the weight of whole particles constituting a powder, and having a particle strength index of 2 wt % or less as indicated by a difference between the mesh passing amounts before and after crushing; a ferrite carrier which is for an electrophotographic developer and in which the surface of the ferrite carrier core material is coated with a resin; and an electrophotographic developer which includes the ferrite carrier and a toner.
    Type: Grant
    Filed: March 29, 2018
    Date of Patent: August 23, 2022
    Assignee: POWDERTECH CO., LTD.
    Inventors: Makoto Ishikawa, Hiroki Sawamoto, Tetsuya Uemura
  • Publication number: 20220019151
    Abstract: The present invention relates to a carrier including: a magnetic core material; and a resin coating layer coating a surface of the magnetic core material, in which the resin coating layer contains a binder resin, and fluorine element-containing resin particles dispersed in the binder resin, the resin coating layer has a coefficient of variation of a film thickness of 25% or less, and the resin coating layer has an average value of the number of the fluorine element-containing resin particles being 3 particles/?m2 or more and 350 particles/?m2 or less per unit area in a cross section of the resin coating layer, and has a coefficient of variation thereof being 20% or less.
    Type: Application
    Filed: February 13, 2020
    Publication date: January 20, 2022
    Applicant: POWDERTECH CO.,LTD.
    Inventors: Aya SAKUTA, Makoto ISHIKAWA, Hiroki SAWAMOTO, Tetsuya UEMURA
  • Patent number: 11112716
    Abstract: The present invention relates to a carrier core material for electrophotographic developer, having a ferrite composition and having a supernatant transmittance of 85.0% or more, a method for producing the carrier core material, a carrier for electrophotographic developer, containing the carrier core material, and a developer containing the carrier.
    Type: Grant
    Filed: January 23, 2020
    Date of Patent: September 7, 2021
    Assignee: POWDERTECH CO., LTD.
    Inventors: Hiroki Sawamoto, Atsushi Nil, Yuji Ito, Hajime Akiba, Shinya Hanyu
  • Patent number: 11099495
    Abstract: To provide a magnetic core material and carrier for electrophotographic developer, which have small environmental dependence of the electric resistance, can suppress the carrier scattering, and can stably provide good images; a developer contains the carrier; and methods for producing them. The magnetic core material satisfying a value of Formula (1): a+b×10+c+d+e+f, being from 20 to 150, when a fluoride ion amount is denoted by a (ppm), a chloride ion amount is denoted by b (ppm), a bromide ion amount is denoted by c (ppm), a nitrite ion amount is denoted by d (ppm), a nitrate ion amount is denoted by e (ppm), and a sulfate ion amount is denoted by f (ppm), which are measured by a combustion ion chromatography method.
    Type: Grant
    Filed: March 6, 2018
    Date of Patent: August 24, 2021
    Assignee: POWDERTECH CO., LTD.
    Inventors: Hiroki Sawamoto, Tetsuya Uemura
  • Patent number: 11029618
    Abstract: There is provided a carrier including a magnetic core material having a surface coated with a surfactant-containing resin mixture of an elemental fluorine-containing resin and a polyimide resin. The carrier has an elution amount of an eluted material into water in an elution test ranging from 180 ppm to 3,500 ppm.
    Type: Grant
    Filed: August 9, 2018
    Date of Patent: June 8, 2021
    Assignee: POWDERTECH CO., LTD.
    Inventors: Aya Sakuta, Makoto Ishikawa, Hiroki Sawamoto, Tetsuya Uemura
  • Patent number: 10996576
    Abstract: Provided are a magnetic core material for electrophotographic developer and a carrier for electrophotographic developer, which are excellent in charge characteristics and strength and with which a satisfactory image free from defects can be obtained, and a developer containing the carrier. A magnetic core material for electrophotographic developer, having a sulfur component content of from 50 to 700 ppm in terms of a sulfate ion and a BET specific surface area of from 0.06 to 0.25 m2/g.
    Type: Grant
    Filed: December 25, 2017
    Date of Patent: May 4, 2021
    Assignee: POWDERTECH CO., LTD.
    Inventors: Hiroki Sawamoto, Tetsuya Uemura
  • Patent number: 10996579
    Abstract: A magnetic core material for electrophotographic developer, satisfying a value of Expression (1): a+b×10+c+d+e+f, being from 200 to 1,400, when an amount of fluorine ion is denoted by a (ppm), an amount of chlorine ion is denoted by b (ppm), an amount of bromide ion is denoted by c (ppm), an amount of nitrite ion is denoted by d (ppm), an amount of nitrate ion is denoted by e (ppm), and an amount of sulfate ion is denoted by f (ppm), which are measured by combustion ion chromatography; and having a pore volume of from 30 to 100 mm3/g.
    Type: Grant
    Filed: January 15, 2018
    Date of Patent: May 4, 2021
    Assignee: POWDERTECH CO., LTD.
    Inventors: Hiroki Sawamoto, Tetsuya Uemura
  • Patent number: 10969706
    Abstract: Provided are a magnetic core material for electrophotographic developer and a carrier for electrophotographic developer, which are excellent in charging characteristics and strength with low specific gravity and with which a satisfactory image free of defects can be obtained, and a developer containing the carrier. A magnetic core material for electrophotographic developer, having a sulfur component content of from 60 to 800 ppm in terms of a sulfate ion and a pore volume of from 30 to 100 mm3/g.
    Type: Grant
    Filed: January 15, 2018
    Date of Patent: April 6, 2021
    Assignee: POWDERTECH CO., LTD.
    Inventors: Hiroki Sawamoto, Tetsuya Uemura
  • Publication number: 20210080847
    Abstract: To provide a magnetic core material for electrophotographic developer and carrier for electrophotographic developer which have small environmental dependence of the electric resistance, can suppress the carrier scattering, and can stably provide good images; a developer contains the carrier; a method for producing the magnetic core material for electrophotographic developer; a method for producing the carrier for electrophotographic developer, and a method for producing the developer. The magnetic core material for electrophotographic developer, satisfying a value of Formula (1): a+b×10+c+d+e+f, being from 20 to 150, when a fluoride ion amount is denoted by a (ppm), a chloride ion amount is denoted by b (ppm), a bromide ion amount is denoted by c (ppm), a nitrite ion amount is denoted by d (ppm), a nitrate ion amount is denoted by e (ppm), and a sulfate ion amount is denoted by f (ppm), which are measured by a combustion ion chromatography method.
    Type: Application
    Filed: March 6, 2018
    Publication date: March 18, 2021
    Inventors: Hiroki SAWAMOTO, Tetsuya UEMURA
  • Patent number: 10754271
    Abstract: A magnetic core material for electrophotographic developer, satisfying a value of Expression (1): a+b×10+c+d+e+f, being from 300 to 1,300, when an amount of fluorine ion is denoted by a (ppm), an amount of chlorine ion is denoted by b (ppm), an amount of bromide ion is denoted by c (ppm), an amount of nitrite ion is denoted by d (ppm), an amount of nitrate ion is denoted by e (ppm), and an amount of sulfate ion is denoted by f (ppm), which are measured by combustion ion chromatography, and having a BET specific surface area being from 0.06 to 0.25 m2/g.
    Type: Grant
    Filed: December 25, 2017
    Date of Patent: August 25, 2020
    Assignee: POWDERTECH CO., LTD.
    Inventors: Hiroki Sawamoto, Tetsuya Uemura
  • Publication number: 20200241435
    Abstract: The present invention relates to a carrier core material for electrophotographic developer, having a ferrite composition and having a supernatant transmittance of 85.0% or more, a method for producing the carrier core material, a carrier for electrophotographic developer, containing the carrier core material, and a developer containing the carrier.
    Type: Application
    Filed: January 23, 2020
    Publication date: July 30, 2020
    Inventors: Hiroki SAWAMOTO, Atsushi NII, Yuji ITO, Hajime AKIBA, Shinya HANYU
  • Publication number: 20200057399
    Abstract: The present invention provides: a ferrite carrier core material for an electrophotographic developer, the material having a mesh passing amount of 3 wt % or less as indicated by the ratio of the weight of particles passing through a 16 ?m-mesh to the weight of whole particles constituting a powder, and having a particle strength index of 2 wt % or less as indicated by a difference between the mesh passing amounts before and after crushing; a ferrite carrier which is for an electrophotographic developer and in which the surface of the ferrite carrier core material is coated with a resin; and an electrophotographic developer which includes the ferrite carrier and a toner.
    Type: Application
    Filed: March 29, 2018
    Publication date: February 20, 2020
    Inventors: Makoto ISHIKAWA, Hiroki SAWAMOTO, Tetsuya UEMURA
  • Publication number: 20200033746
    Abstract: Provided are a magnetic core material for electrophotographic developer and a carrier for electrophotographic developer, which are excellent in charging characteristics and strength with low specific gravity and with which a satisfactory image free of defects can be obtained, and a developer containing the carrier. A magnetic core material for electrophotographic developer, having a sulfur component content of from 60 to 800 ppm in terms of a sulfate ion and a pore volume of from 30 to 100 mm3/g.
    Type: Application
    Filed: January 15, 2018
    Publication date: January 30, 2020
    Inventors: Hiroki SAWAMOTO, Tetsuya UEMURA
  • Publication number: 20200026211
    Abstract: A magnetic core material for electrophotographic developer, satisfying a value of Expression (1): a+b×10+c+d+e+f, being from 200 to 1,400, when an amount of fluorine ion is denoted by a (ppm), an amount of chlorine ion is denoted by b (ppm), an amount of bromide ion is denoted by c (ppm), an amount of nitrite ion is denoted by d (ppm), an amount of nitrate ion is denoted by e (ppm), and an amount of sulfate ion is denoted by f (ppm), which are measured by combustion ion chromatography; and having a pore volume of from 30 to 100 mm3/g.
    Type: Application
    Filed: January 15, 2018
    Publication date: January 23, 2020
    Inventors: Hiroki SAWAMOTO, Tetsuya UEMURA
  • Publication number: 20190346783
    Abstract: A magnetic core material for electrophotographic developer, satisfying a value of Expression (1): a+b×10+c+d+e+f, being from 300 to 1,300, when an amount of fluorine ion is denoted by a (ppm), an amount of chlorine ion is denoted by b (ppm), an amount of bromide ion is denoted by c (ppm), an amount of nitrite ion is denoted by d (ppm), an amount of nitrate ion is denoted by e (ppm), and an amount of sulfate ion is denoted by f (ppm), which are measured by combustion ion chromatography, and having a BET specific surface area being from 0.06 to 0.25 m2/g.
    Type: Application
    Filed: December 25, 2017
    Publication date: November 14, 2019
    Inventors: Hiroki SAWAMOTO, Tetsuya UEMURA
  • Publication number: 20190339628
    Abstract: Provided are a magnetic core material for electrophotographic developer and a carrier for electrophotographic developer, which are excellent in charge characteristics and strength and with which a satisfactory image free from defects can be obtained, and a developer containing the carrier. A magnetic core material for electrophotographic developer, having a sulfur component content of from 50 to 700 ppm in terms of a sulfate ion and a BET specific surface area of from 0.06 to 0.25 m2/g.
    Type: Application
    Filed: December 25, 2017
    Publication date: November 7, 2019
    Inventors: Hiroki SAWAMOTO, Tetsuya UEMURA
  • Publication number: 20190204761
    Abstract: To provide a magnetic core material for electrophotographic developer and carrier for electrophotographic developer which are excellent in a rising-up of charge amount, can suppress a carrier scattering, and can stably provide good images; a developer containing the carrier; a method for producing the magnetic core material for electrophotographic developer; a method for producing the carrier for electrophotographic developer; and a method for producing the developer. The magnetic core material for electrophotographic developer, containing a sulfur component in a content of from 1 to 45 ppm in terms of a sulfate ion.
    Type: Application
    Filed: March 6, 2018
    Publication date: July 4, 2019
    Inventors: Hiroki SAWAMOTO, Tetsuya UEMURA
  • Patent number: 10248039
    Abstract: An object of the present invention is to provide a carrier low in specific gravity and less in both environmental fluctuation and change of the charge amount after aging, an electrophotographic developer using the carrier, and a method of manufacturing the carrier. To achieve the object, the carrier is manufactured by coating a core material composed of a magnetic component and a non-magnetic component with a resin, and the carrier is characterized in that water content is 200 ppm or less and cyclic siloxane content is 100 ppb or less. Further, an electrophotographic developer containing the carrier is provided.
    Type: Grant
    Filed: September 6, 2017
    Date of Patent: April 2, 2019
    Assignee: POWDERTECH CO., LTD.
    Inventors: Hiroki Sawamoto, Hajime Akiba, Tetsuya Uemura
  • Publication number: 20190049870
    Abstract: There is provided a carrier including a magnetic core material having a surface coated with a surfactant-containing resin mixture of an elemental fluorine-containing resin and a polyimide resin. The carrier has an elution amount of an eluted material into water in an elution test ranging from 180 ppm to 3,500 ppm.
    Type: Application
    Filed: August 9, 2018
    Publication date: February 14, 2019
    Inventors: Aya SAKUTA, Makoto ISHIKAWA, Hiroki SAWAMOTO, Tetsuya UEMURA