Patents by Inventor Makoto Okai

Makoto Okai 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: 20210316990
    Abstract: A method of manufacturing a boron nitride nanomaterial, in which boron can be removed more certainly from a boron nitride composition comprising boron that is manufactured using, for example, the thermal plasma vapor growth method. A method of manufacturing a boron nitride nanomaterial comprising: a nanomaterial producing step of producing a boron nitride nanomaterial in which a boron grain(s) is included in a boron nitride fullerene; an oxidation treatment step of forming boron oxide on at least a surface layer of the boron grain(s) by exposing the boron nitride nanomaterial to an oxidizing environment; and a mechanical shock imparting step of applying a mechanical shock for removing the boron grain(s) from the boron nitride nanomaterial that has undergone the oxidation treatment step, while the boron nitride nanomaterial is immersed in a solvent that dissolves the boron oxide.
    Type: Application
    Filed: November 9, 2019
    Publication date: October 14, 2021
    Inventor: Makoto OKAI
  • Patent number: 10793938
    Abstract: Provided is a method for producing a boron nitride nanotube-reinforced aluminum composite casting, the method being capable of reducing cost. The method for producing a boron nitride nanotube-reinforced aluminum composite casting comprises the steps of: (a) mixing boron nitride nanotubes and a first aluminum matrix and then pelletizing the resulting mixture; (b) heating and subjecting pellets obtained in step (a) to melt mixing to obtain a melt; (c) cooling and solidifying the melt obtained in step (b) to obtain a master batch; and (d) subjecting the master batch obtained in step (c) and the second aluminum matrix to melt mixing, and then cooling and solidifying the resulting mixture.
    Type: Grant
    Filed: June 6, 2019
    Date of Patent: October 6, 2020
    Assignee: HITACHI METALS, LTD.
    Inventors: Makoto Okai, Hideki Yamaura, Kazutoshi Sugie, Hideya Yamane
  • Publication number: 20190376169
    Abstract: Provided is a method for producing a boron nitride nanotube-reinforced aluminum composite casting, the method being capable of reducing cost. The method for producing a boron nitride nanotube-reinforced aluminum composite casting comprises the steps of: (a) mixing boron nitride nanotubes and a first aluminum matrix and then pelletizing the resulting mixture; (b) heating and subjecting pellets obtained in step (a) to melt mixing to obtain a melt; (c) cooling and solidifying the melt obtained in step (b) to obtain a master batch; and (d) subjecting the master batch obtained in step (c) and the second aluminum matrix to melt mixing, and then cooling and solidifying the resulting mixture.
    Type: Application
    Filed: June 6, 2019
    Publication date: December 12, 2019
    Applicant: HITACHI METALS, LTD.
    Inventors: Makoto OKAI, Hideki YAMAURA, Kazutoshi SUGIE, Hideya YAMANE
  • Publication number: 20190316233
    Abstract: There is provided a composite of a metallic matrix and boron nitride nanotubes, the metallic matrix including aluminum or an aluminum alloy. Also, there is provided a method for manufacturing the composite. The method includes: a powder mixing step of mixing a powder of boron nitride nanotubes and a powder of an element soluble in a molten metal of the metallic matrix to prepare a powder mixture of boron nitride nanotubes and a metallic matrix-soluble element; an alloy melt mixing step of mixing the powder mixture and the molten metal of the metallic matrix to prepare a metallic matrix melt mixed with boron nitride nanotubes; and a casting step of solidifying the metallic matrix melt mixed with boron nitride nanotubes to obtain the composite.
    Type: Application
    Filed: April 15, 2019
    Publication date: October 17, 2019
    Applicant: HITACHI METALS, LTD.
    Inventors: Makoto OKAI, Hideki YAMAURA, Hideya YAMANE
  • Patent number: 9997771
    Abstract: To provide a negative electrode material having a high initial capacity and a long charge and discharge cycle life A negative electrode material according to the present invention contains a particle of a negative electrode active material that occludes and releases lithium ions and a carbon fiber, wherein the negative electrode active material occludes lithium by forming an alloy with the lithium, a surface of the negative electrode active material particle is coated with carbon, and the carbon fiber is bonded to the surface of the carbon via an adhesive resin.
    Type: Grant
    Filed: December 5, 2013
    Date of Patent: June 12, 2018
    Assignee: Hitachi, Ltd.
    Inventors: Shuichi Suzuki, Etsuko Nishimura, Makoto Okai, Toshio Abe
  • Publication number: 20180159124
    Abstract: The objective of the present invention is to provide a negative electrode active material for lithium ion secondary batteries, which has high capacity and a long service life by solving the aforementioned problem. A negative electrode active material for lithium ion secondary batteries, which comprises scale-like silicon particles, and wherein the surface of each scale-like silicon particle is covered with a carbon layer.
    Type: Application
    Filed: May 25, 2016
    Publication date: June 7, 2018
    Applicant: HITACHI, LTD.
    Inventor: Makoto OKAI
  • Publication number: 20170309913
    Abstract: An object of the present invention is to provide a negative electrode active material for a lithium ion secondary battery, the negative electrode active material particularly having a high capacity and a long lifetime. A negative electrode material for a lithium ion secondary battery, containing: silicon nanoparticles; and silicon nanowires, wherein the silicon nanoparticles and the silicon nanowires are bound to each other. More preferably, the negative electrode active material for a lithium ion secondary battery, wherein a surface of the silicon nanoparticle or the silicon nanowire is covered with a carbon coating layer.
    Type: Application
    Filed: November 14, 2014
    Publication date: October 26, 2017
    Inventors: Makoto OKAI, Takashi KYOTANI, Hirotomo NISHIHARA, Takatoshi KASUKABE
  • Publication number: 20160308194
    Abstract: To provide a negative electrode material having a high initial capacity and a long charge and discharge cycle life A negative electrode material according to the present invention contains a particle of a negative electrode active material that occludes and releases lithium ions and a carbon fiber, wherein the negative electrode active material occludes lithium by forming an alloy with the lithium, a surface of the negative electrode active material particle is coated with carbon, and the carbon fiber is bonded to the surface of the carbon via an adhesive resin.
    Type: Application
    Filed: December 5, 2013
    Publication date: October 20, 2016
    Applicant: Hitachi, Ltd.
    Inventors: Shuichi SUZUKI, Etsuko NISHIMURA, Makoto OKAI, Toshio ABE
  • Publication number: 20150357632
    Abstract: An object of the present invention is to provide a lithium secondary battery having a negative electrode having a novel structure in which the metal content is increased as compared to the past and the capacity density of the negative electrode is increased, and the lithium occlusion capacity of the metal is not decreased by repeated charge and discharge. In order to achieve this object, the negative electrode active material for a lithium secondary battery is characterized by being composed of a mixture of graphite particles capable of occluding and emitting lithium ions and particles containing metal, wherein the average particle diameter of the particles containing metal during discharge is 1/2000 to 1/10 of that of the graphite particles, the graphite particles have an average particle diameter during discharge of 2 ?m to 20 ?m, and addition ratio by weight of the particles containing metal is 10% to 50%.
    Type: Application
    Filed: February 7, 2013
    Publication date: December 10, 2015
    Applicant: HITACHI, LTD.
    Inventors: Etsuko NISHIMURA, Akihide TANAKA, Katsunori NISHIMURA, Shuichi SUZUKI, Makoto OKAI, Masao SHIMIZU
  • Patent number: 8635710
    Abstract: Optical information and topographic information of the surface of a sample are measured at a nanometer-order resolution and with high reproducibility without damaging a probe and the sample by combining a nanometer-order cylindrical structure with a nanometer-order microstructure to form a plasmon intensifying near-field probe having a nanometer-order optical resolution and by repeating approach/retreat of the probe to/from each measurement point on the sample at a low contact force.
    Type: Grant
    Filed: April 13, 2012
    Date of Patent: January 21, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiko Nakata, Masahiro Watanabe, Takashi Inoue, Kishio Hidaka, Makoto Okai, Toshiaki Morita, Motoyuki Hirooka
  • Patent number: 8507893
    Abstract: Provided are an electronic device and a light-receiving and light-emitting device which can control the electron configuration of a graphene sheet and the band gap thereof, and an electronic integrated circuit and an optical integrated circuit which use the devices. By shaping the graphene sheet into a curve, the electron configuration thereof is controlled. The graphene sheet can be shaped into a curve by forming the sheet on a base film having a convex structure or a concave structure. The local electron states in the curved part can be formed by bending the graphene sheet. Thus, the same electron states as the cylinder or cap part of a nanotube can be realized, and the band gaps at the K points in the reciprocal lattice space can be formed.
    Type: Grant
    Filed: May 26, 2009
    Date of Patent: August 13, 2013
    Assignee: Hitachi, Ltd.
    Inventor: Makoto Okai
  • Patent number: 8476739
    Abstract: A graphene-on-oxide substrate according to the present invention includes: a substrate having a metal oxide layer formed on its surface; and, formed on the metal oxide layer, a graphene layer including at least one atomic layer of the graphene. The graphene layer is grown generally parallel to the surface of the metal oxide layer, and the inter-atomic-layer distance between the graphene atomic layer adjacent to the surface of the metal oxide layer and the surface atomic layer of the metal oxide layer is 0.34 nm or less. Preferably, the arithmetic mean surface roughness Ra of the metal oxide layer is 1 nm or less.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: July 2, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Okai, Motoyuki Hirooka, Takashi Kyotani, Hironori Orikasa
  • Patent number: 8471237
    Abstract: A circuit board having a graphene circuit according to the present invention includes: a base substrate; a patterned aluminum oxide film formed on the base substrate, the patterned aluminum oxide film having an average composition of Al2?xO3+x (where x is 0 or more), the patterned aluminum oxide film having a recessed region whose surface has one or more cone-shaped recesses therein; a graphene film preferentially grown only on the patterned aluminum oxide film, the graphene film having one or more graphene atomic layers, the graphene film having a contact region that covers the recessed region, the graphene film growing parallel to a flat surface of the recessed region and parallel to an inner wall surface of each cone-shaped recess of the recessed region; and a patterned metal film, a part of the patterned metal film covering and having electrical contact with the contact region, the patterned metal film filling each recess covered by the graphene film.
    Type: Grant
    Filed: January 26, 2011
    Date of Patent: June 25, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Okai, Motoyuki Hirooka, Yasuo Wada
  • Patent number: 8438660
    Abstract: The stress due to contact between a probe and a measurement sample is improved when using a microcontact prober having a conductive nanotube, nanowire, or nanopillar probe, the insulating layer at the contact interface is removed, thereby the contact resistance is reduced, and the performance of semiconductor device examination is improved. The microcontact prober comprises a cantilever probe in which each cantilever is provided with a nanowire, nanopillar, or a metal-coated carbon nanotube probe projecting by 50 to 100 nm from a holder provided at the fore end and a vibrating mechanism for vibrating the cantilever horizontally with respect to the subject. The fore end of the holder may project from the free end of the cantilever, and the fore end of the holder can be checked from above the cantilever.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: May 7, 2013
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Motoyuki Hirooka, Makoto Okai
  • Patent number: 8410474
    Abstract: A substrate having a graphene film grown thereon according to the present invention includes: a base substrate; a patterned aluminum oxide film formed on the base substrate, the patterned aluminum oxide film having an average composition of Al2?xO3+x (where x is 0 or more); and a graphene film preferentially grown only on the patterned aluminum oxide film, the graphene film having one or more graphene atomic layers, the graphene film growing parallel to a surface of the patterned aluminum oxide film, the graphene film having an electrical conductivity of 1×104 S/cm or more measured by a four-probe resistive method using an inter-voltage-probe distance of 0.2 mm.
    Type: Grant
    Filed: January 20, 2011
    Date of Patent: April 2, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Okai, Motoyuki Hirooka, Yasuo Wada
  • Patent number: 8407811
    Abstract: In a scanning probe microscope, a nanotube and metal nano-particles are combined together to configure a plasmon-enhanced near-field probe having an optical resolution on the order of nanometers as a measuring probe in which a metal structure is embedded, and this plasmon-enhanced near-field probe is installed in a highly-efficient plasmon exciting unit to repeat approaching to and retracting from each measuring point on a sample with a low contact force, so that optical information and profile information of the surface of the sample are measured with a resolution on the order of nanometers, a high S/N ratio, and high reproducibility without damaging both of the probe and the sample.
    Type: Grant
    Filed: February 25, 2010
    Date of Patent: March 26, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiko Nakata, Masahiro Watanabe, Takashi Inoue, Kishio Hidaka, Makoto Okai, Motoyuki Hirooka
  • Patent number: 8278658
    Abstract: An device according to the present invention comprises: graphene; and a metal electrode, the metal electrode and the graphene being electrically connected, the following relationship of Eq. (1) being satisfied: coth ? ( r GP r C ? S ) < 1.3 , Eq . ? ( 1 ) where rGP (in units of ?/?m2) denotes the electrical resistance of a graphene layer per unit area, rC (in units of ??m2) denotes the contact resistance per unit area between the graphene layer and a metal electrode, and S denotes the contact area (in units of ?m2) between the graphene layer and the metal electrode.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: October 2, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Okai, Motoyuki Hirooka
  • Publication number: 20120204297
    Abstract: Optical information and topographic information of the surface of a sample are measured at a nanometer-order resolution and with high reproducibility without damaging a probe and the sample by combining a nanometer-order cylindrical structure with a nanometer-order microstructure to form a plasmon intensifying near-field probe having a nanometer-order optical resolution and by repeating approach/retreat of the probe to/from each measurement point on the sample at a low contact force.
    Type: Application
    Filed: April 13, 2012
    Publication date: August 9, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Toshihiko NAKATA, Masahiro Watanabe, Takashi Inoue, Kishio Hidaka, Makoto Okai, Toshiaki Morita, Motoyuki Hirooka
  • Patent number: 8181268
    Abstract: Optical information and topographic information of the surface of a sample are measured at a nanometer-order resolution and with high reproducibility without damaging a probe and the sample by combining a nanometer-order cylindrical structure with a nanometer-order microstructure to form a plasmon intensifying near-field probe having a nanometer-order optical resolution and by repeating approach/retreat of the probe to/from each measurement point on the sample at a low contact force.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: May 15, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiko Nakata, Masahiro Watanabe, Takashi Inoue, Kishio Hidaka, Makoto Okai, Toshiaki Morita, Motoyuki Hirooka
  • Publication number: 20120090056
    Abstract: The stress due to contact between a probe and a measurement sample is improved when using a microcontact prober having a conductive nanotube, nanowire, or nanopillar probe, the insulating layer at the contact interface is removed, thereby the contact resistance is reduced, and the performance of semiconductor device examination is improved. The microcontact prober comprises a cantilever probe in which each cantilever is provided with a nanowire, nanopillar, or a metal-coated carbon nanotube probe projecting by 50 to 100 nm from a holder provided at the fore end and a vibrating mechanism for vibrating the cantilever horizontally with respect to the subject. The fore end of the holder may project from the free end of the cantilever, and the fore end of the holder can be checked from above the cantilever.
    Type: Application
    Filed: May 26, 2010
    Publication date: April 12, 2012
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Motoyuki Hirooka, Makoto Okai