Patents by Inventor Yoshihito Yokoyama

Yoshihito Yokoyama 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: 10535866
    Abstract: A scale-like graphite and carbon material for a battery electrode which is suitable for use as an electrode material for an aqueous-electrolyte secondary battery, wherein the ratio IG/ID (G value) between the peak area (ID) in a range of 1300 to 1400 cm?1 and the peak area (IG) in a range of 1580 to 1620 cm?1 by Raman spectroscopy spectra, in which an edge surface of the particle of the scale-like graphite is measured with by a Raman microspectrometer, is 5.2 to 100 and the average interplanar spacing d002 of plane (d002) by the X-ray diffraction method is 0.337 nm or less and optical structures of the scale-like graphite have a specific shape; the method for producing the same; a carbon material for a battery electrode and a paste for an electrode containing the material; and a secondary battery having excellent charge/discharge cycle characteristics and high current load characteristics.
    Type: Grant
    Filed: June 27, 2013
    Date of Patent: January 14, 2020
    Assignee: SHOWA DENKO K.K.
    Inventors: Yasuaki Wakizaka, Yuichi Kamijo, Tomohiro Abe, Yoshiki Shimodaira, Akinori Sudoh, Chiaki Sotowa, Yoshihito Yokoyama, Takashi Terashima
  • Publication number: 20190319277
    Abstract: A thermoplastic resin composition which includes 50% to 90% by mass of a powder material (A) and 50% to 10% by mass of a ?-olefin-based thermoplastic resin (B), wherein the ?-olefin-based thermoplastic resin (B) includes a first ?-olefin-based thermoplastic resin (B1) having an isotactic pentad fraction [mmmm] of 70% to 99% and a melting point in the range of 120° C. to 168° C., and a second ?-olefin-based thermoplastic resin (B2) having an isotactic pentad fraction [mmmm] of 30% to 60% and a melting point in the range of 60° C. to 100° C., and the mass ratio ((B2)/(B1)) of the second ?-olefin-based thermoplastic resin (B2) relative to the first ?-olefin-based thermoplastic resin (B1) is 0.3 to 2.0.
    Type: Application
    Filed: December 21, 2017
    Publication date: October 17, 2019
    Applicant: SHOWA DENKO K.K.
    Inventors: Yoshihito YOKOYAMA, Masayuki NOGUCHI, Tabashi IINO
  • Patent number: 9614218
    Abstract: A composite carbon particle for use in a negative electrode of a lithium-ion secondary battery, the composite carbon particle including a core particle composed of a carbon material obtained by heating, at not higher than 2500° C., petroleum coke having a Hardgrove grindability index (HGI value) of 30 to 60 (defined by ASTM D409), and a covering layer composed of a carbonaceous material obtained by heating an organic compound at 1000° C. to 2000° C. The composite carbon particle has a 50% particle diameter (D50) of 1 ?m to 30 ?m in a volume-based cumulative particle size distribution as measured by a laser diffraction method.
    Type: Grant
    Filed: October 11, 2013
    Date of Patent: April 4, 2017
    Assignee: SHOWA DENKO K.K.
    Inventors: Masataka Takeuchi, Yoshihito Yokoyama, Chiaki Sotowa
  • Patent number: 9406936
    Abstract: A carbon material containing boron atom in an amount of 0.001 to 0.5 mass %, in which the average interplanar spacing (d002) of plane (002) is 0.337 nm or less. By observing optical structures in cross-section of formed bodies made of the carbon material, when areas are accumulated from a smallest structure in an ascending order, SOP represents an area of an optical structure whose accumulated area corresponds to 60% of the total area of all optical structures; when the structures are counted from a structure of a smallest aspect ratio in an ascending order, AROP represents the aspect ratio of the structure which ranks at the position of 60% in total number of all the structures; and when D50 represents an average particle diameter; SOP, AROP and D50 satisfy the following relationship: 1.5?AROP?6 and 0.2×D50?(SOP×AROP)1/2<2×D50. Also disclosed is a secondary battery using the carbon material as an electrode material.
    Type: Grant
    Filed: October 11, 2013
    Date of Patent: August 2, 2016
    Assignee: SHOWA DENKO K.K.
    Inventors: Yasuaki Wakizaka, Yuichi Kamijo, Tomohiro Abe, Yoshiki Shimodaira, Akinori Sudoh, Chiaki Sotowa, Yoshihito Yokoyama, Takashi Terashima, Naoto Kawaguchi
  • Publication number: 20150270535
    Abstract: A composite carbon particle for use in a negative electrode of a lithium-ion secondary battery, the composite carbon particle including a core particle composed of a carbon material obtained by heating, at not higher than 2500° C., petroleum coke having a Hardgrove grindability index (HGI value) of 30 to 60 (defined by ASTM D409), and a covering layer composed of a carbonaceous material obtained by heating an organic compound at 1000° C. to 2000° C. The composite carbon particle has a 50% particle diameter (D50) of 1 ?m to 30 ?m in a volume-based cumulative particle size distribution as measured by a laser diffraction method.
    Type: Application
    Filed: October 11, 2013
    Publication date: September 24, 2015
    Applicant: SHOWA DENKO K.K.
    Inventors: Masataka Takeuchi, Yoshihito Yokoyama, Chiaki Sotowa
  • Publication number: 20150263348
    Abstract: A carbon material containing boron atom in an amount of 0.001 to 0.5 mass %, in which the average interplanar spacing (d002) of plane (002) is 0.337 nm or less. By observing optical structures in cross-section of formed bodies made of the carbon material, when areas are accumulated from a smallest structure in an ascending order, SOP represents an area of an optical structure whose accumulated area corresponds to 60% of the total area of all optical structures; when the structures are counted from a structure of a smallest aspect ratio in an ascending order, AROP represents the aspect ratio of the structure which ranks at the position of 60% in total number of all the structures; and when D50 represents an average particle diameter; SOP, AROP and D50 satisfy the following relationship: 1.5?AROP?6 and 0.2×D50?(SOP×AROP)1/2<2×D50. Also disclosed is a secondary battery using the carbon material as an electrode material.
    Type: Application
    Filed: October 11, 2013
    Publication date: September 17, 2015
    Applicant: SHOWA DENKO K.K.
    Inventors: Yasuaki Wakizaka, Yuichi Kamijo, Tomohiro Abe, Yoshiki Shimodaira, Akinori Sudoh, Chiaki Sotowa, Yoshihito Yokoyama, Takashi Terashima, Naoto Kawaguchi
  • Publication number: 20150162600
    Abstract: A scale-like carbon material and carbon material for a battery electrode suitable for use as an electrode material for an aqueous-electrolyte secondary battery, wherein the ratio IG/ID (G value) between the peak area (ID) in a range of 1300 to 1400 cm?1 and the peak area (IG) in a range of 1580 to 1620 cm?1 by Raman spectroscopy spectra when an edge surface of the particle of the scale-like carbon material is measured with by Raman microspectrometer is 5.2 to 100 and the average interplanar spacing d002 of plane (d002) by the X-ray diffraction method is 0.337 nm or less and optical structures of the carbon material have a specific shape; the method for producing the same; a carbon material for a battery electrode and a paste for an electrode containing the material; and a secondary battery having excellent charge/discharge cycle characteristics and high current load characteristics.
    Type: Application
    Filed: June 27, 2013
    Publication date: June 11, 2015
    Applicant: SHOWA DENKO K.K.
    Inventors: Yasuaki Wakizaka, Yuichi Kamijo, Tomohiro Abe, Yoshiki Shimodaira, Akinori Sudoh, Chiaki Sotowa, Yoshihito Yokoyama, Takashi Terashima
  • Publication number: 20140057166
    Abstract: Provided are Composite graphite particles comprising core material comprising graphite obtained by heat treating petroleum based coke with a grindability index of 35 to 60 at a temperature of not less than 2500° C. and not more than 3500° C. and carbonaceous layer present on the surface of the core material, wherein the composite graphite particles have an intensity ratio ID/IG of 0.1 or more in intensity (ID) of peak in the range between 1300 and 1400 cm?1 and intensity (IG) of peak in the range between 1500 and 1620 cm?1 as measured by Raman spectroscopy spectrum, the composite graphite particles have a 50% particle diameter (D50) of not less than 3 ?m and not more than 30 ?m in accumulated particle size distribution by volume as measured by the laser diffraction method, and the composite graphite particles have a ratio I110/I004 of 0.
    Type: Application
    Filed: December 7, 2012
    Publication date: February 27, 2014
    Applicant: SHOWA DENKO K.K.
    Inventors: Yoshihito Yokoyama, Chiaki Sotowa, Masataka Takeuchu
  • Patent number: 6040704
    Abstract: A probe unit comprises a support member having an edge extending in a first direction parallel to the surface of a plate-like test substance; and a plurality of needle-like probes disposed on the edge and extended in a third direction intersecting the first direction and a second direction perpendicular to the surface of the test substance. The plurality of probes are divided into at least a first group and a second group arranged at intervals in the second direction.
    Type: Grant
    Filed: May 16, 1997
    Date of Patent: March 21, 2000
    Assignee: Kabushiki Kaisha Nihon Micronics
    Inventors: Motoyasu Kondo, Fukuyo Sakuma, Youichi Urakawa, Yoshihito Yokoyama, Masatoshi Hinai