Patents by Inventor Makoto Yonemitsu

Makoto Yonemitsu 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: 11721361
    Abstract: There are provided: an aluminum alloy substrate for a magnetic disk, the aluminum alloy substrate including an aluminum alloy including 0.4 to 3.0 mass % of Fe and the balance of Al and unavoidable impurities, in which second phase particles having a longest diameter of 0.5 ?m or more and less than 2.0 ?m are dispersed at a distribution density of 5000 particles/mm2 or more; a method for producing the same; and a magnetic disk using the aluminum alloy substrate for a magnetic disk.
    Type: Grant
    Filed: April 9, 2018
    Date of Patent: August 8, 2023
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kotaro Kitawaki, Takuya Murata, Makoto Yonemitsu, Yu Matsui, Yasuo Fujii, Ryo Sakamoto, Takashi Nakayama, Wataru Kumagai
  • Patent number: 11482251
    Abstract: An aluminum alloy substrate for a magnetic disk including an aluminum alloy containing 0.1 to 3.0 mass % of Fe, 0.005 to 1.000 mass % of Cu, and 0.005 to 1.000 mass % of Zn, with a balance of Al and inevitable impurities, wherein in an outer peripheral surface thereof, the number of holes having maximum diameters of 10 ?m or more is 200/mm2 or less, an aluminum alloy base disk for a magnetic disk and a magnetic disk, using the aluminum alloy substrate, and methods for manufacturing these.
    Type: Grant
    Filed: October 25, 2019
    Date of Patent: October 25, 2022
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Takuya Murata, Kotaro Kitawaki, Makoto Yonemitsu, Hideyuki Hatakeyama, Ryo Sakamoto, Hiroki Ota
  • Patent number: 11404082
    Abstract: Provided is an aluminium alloy substrate for a magnetic disk, a method for fabricating the substrate, and a magnetic disk composed of the aluminium alloy substrate for a magnetic disk. The substrate contains an aluminium alloy composed of one or more elements selected from a group comprising 0.05 to 3.00 mass % (hereinafter abbreviated as “%”) of Fe, 0.05% to 3.00% of Mn, 0.05% to 18.00% of Si, 0.05% to 8.00% of Ni, 0.05% to 3.00% of Cr, and 0.05% to 3.00% of Zr, with a balance of Al and unavoidable impurities. The substrate has a Young modulus of 67 GPa or more in each of the 0° direction, 45° direction, and 90° direction relative to the rolling direction of the substrate.
    Type: Grant
    Filed: September 18, 2019
    Date of Patent: August 2, 2022
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kotaro Kitawaki, Makoto Yonemitsu, Takashi Nakayama, Kimie Imakawa, Hideyuki Hatakeyama
  • Patent number: 11361791
    Abstract: An aluminum alloy sheet for a magnetic disk includes an aluminum alloy comprising 0.10 to 3.00 mass % (hereafter simply “%”) of Fe, 0.1 to 3.0% of Mn, 0.003 to 1.000% of Cu, and 0.005 to 1.000 s % of Zn, wherein second phase particles having a maximum diameter of 100 ?m or more and 300 ?m or less are dispersed at a distribution density of 50 particles/mm2 or less in a region (A) occupying 25% or less of a sheet thickness from a sheet thickness center plane to opposite surfaces of the sheet, second phase particles having a maximum diameter of 100 ?m or more and 300 ?m or less are 0 particles/mm2 in a region (C) that is obtained by excluding the region (A) from a region (B) occupying 50% or less of the sheet thickness from the sheet thickness center plane to the opposite surfaces of the sheet, and the amount of Mn solid solution is 0.03 mass % or more.
    Type: Grant
    Filed: July 24, 2019
    Date of Patent: June 14, 2022
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kotaro Kitawaki, Makoto Yonemitsu, Hideyuki Hatakeyama, Sadayuki Toda, Ryo Sakamoto, Yasuo Fujii
  • Patent number: 11341995
    Abstract: An aluminum alloy sheet for a magnetic disk, a method for manufacturing same, and a magnetic disk using same. The aluminum alloy sheet is made of an aluminum alloy comprising 0.10 to 3.00 mass % of Fe, 0.003 to 1.000 mass % of Cu, and 0.005 to 1.000 mass % of Zn, with a balance of Al and unavoidable impurities, wherein a value obtained by dividing a difference in an area ratio (%) of second phase particles between a region (A) and a region (B) by an average value of area ratios (%) of second phase particles in the regions (A) and (B) is 0.05 or less, the region (A) being a region from a sheet thickness center plane to a front surface of the sheet, and the region (B) being a region from the sheet thickness center plane to a rear surface of the plate.
    Type: Grant
    Filed: October 15, 2019
    Date of Patent: May 24, 2022
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO.. LTD.
    Inventors: Kotaro Kitawaki, Yu Igarashi, Keisuke Kamiya, Yu Matsui, Makoto Yonemitsu, Ryo Sakamoto, Hideyuki Hatakeyama, Hiroki Ota
  • Patent number: 11270730
    Abstract: A magnetic disk substrate is composed of an aluminum alloy substrate, a base plating layer on a surface of the aluminum alloy substrate, and a boundary region between the aluminum alloy substrate and the base plating layer. The boundary region includes a specific boundary region (D(1)I(50-84)) having Al emission intensities equal to 50% to 84% of an average Al emission intensity in an interior region of the aluminum alloy substrate in glow discharge optical emission spectroscopy in the depthwise direction from the surface of the magnetic disk substrate. The specific boundary region (D(1)I(50-84)) has a maximum Fe emission intensity (I(1)Fe(max)) higher than an average Fe emission intensity (I(1)Fe(ave)) in the interior region of the aluminum alloy substrate in the glow discharge optical emission spectroscopy.
    Type: Grant
    Filed: November 28, 2018
    Date of Patent: March 8, 2022
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Takuya Murata, Kotaro Kitawaki, Makoto Yonemitsu, Yasuo Fujii, Ryo Sakamoto, Hideyuki Hatakeyama, Sadayuki Toda
  • Patent number: 11211088
    Abstract: Provided are a magnetic disk and a method of fabricating the magnetic disk. The magnetic disk includes an aluminum alloy plate fabricated by a process involving a CC method and a compound removal process, and an electroless Ni—P plating layer disposed on the surface of the plate. The aluminum alloy plate is composed of an aluminum alloy containing 0.4 to 3.0 mass % (hereinafter abbreviated simply as “%”) of Fe, 0.1% to 3.0% of Mn, 0.005% to 1.000% of Cu, 0.005% to 1.000% of Zn, with a balance of Al and unavoidable impurities. In the magnetic disk, the maximum amplitude of waviness in a wavelength range of 0.4 to 5.0 mm is 5 nm or less, and the maximum amplitude of waviness in a wavelength range of 0.08 to 0.45 mm is 1.5 nm or less.
    Type: Grant
    Filed: November 28, 2018
    Date of Patent: December 28, 2021
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Takuya Murata, Kotaro Kitawaki, Makoto Yonemitsu, Hideyuki Hatakeyama, Takashi Nakayama, Ryo Sakamoto, Hiroki Ota
  • Patent number: 11208710
    Abstract: Provided are: an aluminum alloy substrate for a magnetic disk, including an aluminum alloy including 0.4 to 3.0 mass % of Fe with the balance of Al and unavoidable impurities; a method for producing the aluminum alloy substrate for a magnetic disk; and a magnetic disk in which an electroless Ni—P plating treatment layer and a magnetic layer formed thereon are disposed on a surface of the aluminum alloy substrate for a magnetic disk.
    Type: Grant
    Filed: February 9, 2018
    Date of Patent: December 28, 2021
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kotaro Kitawaki, Takuya Murata, Makoto Yonemitsu, Kouichiro Takiguchi, Takashi Nakayama, Kimie Imakawa, Yasuo Fujii, Hideyuki Hatakeyama
  • Publication number: 20210358520
    Abstract: An aluminum alloy substrate for a magnetic disk including an aluminum alloy containing 0.1 to 3.0 mass % of Fe, 0.005 to 1.000 mass % of Cu, and 0.005 to 1.000 mass % of Zn, with a balance of Al and inevitable impurities, wherein in an outer peripheral surface thereof, the number of holes having maximum diameters of 10 ?m or more is 200/mm2 or less, an aluminum alloy base disk for a magnetic disk and a magnetic disk, using the aluminum alloy substrate, and methods for manufacturing these.
    Type: Application
    Filed: October 25, 2019
    Publication date: November 18, 2021
    Inventors: Takuya MURATA, Kotaro KITAWAKI, Makoto YONEMITSU, Hideyuki HATAKEYAMA, Ryo SAKAMOTO, Hiroki OTA
  • Publication number: 20210319806
    Abstract: An aluminum alloy sheet for a magnetic disk, a method for manufacturing same, and a magnetic disk using same. The aluminum alloy sheet is made of an aluminum alloy comprising 0.10 to 3.00 mass % of Fe, 0.003 to 1.000 mass % of Cu, and 0.005 to 1.000 mass % of Zn, with a balance of Al and unavoidable impurities, wherein a value obtained by dividing a difference in an area ratio (%) of second phase particles between a region (A) and a region (B) by an average value of area ratios (%) of second phase particles in the regions (A) and (B) is 0.05 or less, the region (A) being a region from a sheet thickness center plane to a front surface of the sheet, and the region (B) being a region from the sheet thickness center plane to a rear surface of the plate.
    Type: Application
    Filed: October 15, 2019
    Publication date: October 14, 2021
    Inventors: Kotaro KITAWAKI, Yu IGARASHI, Keisuke KAMIYA, Yu MATSUI, Makoto YONEMITSU, Ryo SAKAMOTO, Hideyuki HATAKEYAMA, Hiroki OTA
  • Publication number: 20210264944
    Abstract: An aluminum alloy sheet for a magnetic disk includes an aluminum alloy comprising 0.10 to 3.00 mass % (hereafter simply “%”) of Fe, 0.1 to 3.0% of Mn, 0.003 to 1.000% of Cu, and 0.005 to 1.000 s % of Zn, wherein second phase particles having a maximum diameter of 100 ?m or more and 300 ?m or less are dispersed at a distribution density of 50 particles/mm2 or less in a region (A) occupying 25% or less of a sheet thickness from a sheet thickness center plane to opposite surfaces of the sheet, second phase particles having a maximum diameter of 100 ?m or more and 300 ?m or less are 0 particles/mm2 in a region (C) that is obtained by excluding the region (A) from a region (B) occupying 50% or less of the sheet thickness from the sheet thickness center plane to the opposite surfaces of the sheet, and the amount of Mn solid solution is 0.03 mass % or more.
    Type: Application
    Filed: July 24, 2019
    Publication date: August 26, 2021
    Inventors: Kotaro KITAWAKI, Makoto YONEMITSU, Hideyuki HATAKEYAMA, Sadayuki TODA, Ryo SAKAMOTO, Yasuo FUJII
  • Publication number: 20210201946
    Abstract: Provided is an aluminium alloy substrate for a magnetic disk, a method for fabricating the substrate, and a magnetic disk composed of the aluminium alloy substrate for a magnetic disk. The substrate contains an aluminium alloy composed of one or more elements selected from a group comprising 0.05 to 3.00 mass % (hereinafter abbreviated as “%”) of Fe, 0.05% to 3.00% of Mn, 0.05% to 18.00% of Si, 0.05% to 8.00% of Ni, 0.05% to 3.00% of Cr, and 0.05% to 3.00% of Zr, with a balance of Al and unavoidable impurities. The substrate has a Young modulus of 67 GPa or more in each of the 0° direction, 45° direction, and 90° direction relative to the rolling direction of the substrate.
    Type: Application
    Filed: September 18, 2019
    Publication date: July 1, 2021
    Inventors: Kotaro KITAWAKI, Makoto YONEMITSU, Takashi NAKAYAMA, Kimie IMAKAWA, Hideyuki HATAKEYAMA
  • Patent number: 11037594
    Abstract: Provided is an aluminum alloy substrate for a magnetic disk that includes an aluminum alloy containing 0.4 to 3.0 mass % (hereinafter abbreviated as “%”) of Fe, 0.005% to 1.000% of Cu, and 0.005% to 1.000% of Zn, with a balance of Al and unavoidable impurities. This substrate has a ratio A/B of 0.70 or more, where A indicates a distribution density of Al—Fe intermetallic compound particles having maximum diameters of 10 ?m or more and less than 16 ?m, and B indicates a distribution density of Al—Fe intermetallic compound particles having maximum diameters of 10 ?m or more. The distribution density of Al—Fe intermetallic compound particles having maximum diameters of 40 ?m or more is at most one per square millimeter. Also provided are a method of fabricating this aluminum alloy substrate for a magnetic disk and a magnetic disk composed of the aluminum alloy substrate for a magnetic disk.
    Type: Grant
    Filed: February 6, 2019
    Date of Patent: June 15, 2021
    Assignees: UACJ CORPORATION, FURUKAWA ELECTRIC CO., LTD.
    Inventors: Kotaro Kitawaki, Makoto Yonemitsu, Hideyuki Hatakeyama, Takashi Nakayama, Yasuo Fujii, Ryo Sakamoto
  • Publication number: 20210151077
    Abstract: There are provided: an aluminum alloy substrate for a magnetic disk, the aluminum alloy substrate including an aluminum alloy including 0.4 to 3.0 mass % of Fe and the balance of Al and unavoidable impurities, in which second phase particles having a longest diameter of 0.5 ?m or more and less than 2.0 ?m are dispersed at a distribution density of 5000 particles/mm2 or more; a method for producing the same; and a magnetic disk using the aluminum alloy substrate for a magnetic disk.
    Type: Application
    Filed: April 9, 2018
    Publication date: May 20, 2021
    Inventors: Kotaro KITAWAKI, Takuya MURATA, Makoto YONEMITSU, Yu MATSUI, Yasuo FUJII, Ryo SAKAMOTO, Takashi NAKAYAMA, Wataru KUMAGAI
  • Publication number: 20210050034
    Abstract: A magnetic disk substrate is composed of an aluminum alloy substrate, a base plating layer on a surface of the aluminum alloy substrate, and a boundary region between the aluminum alloy substrate and the base plating layer. The boundary region includes a specific boundary region (D(1)I((50-84)) having A, emission intensities equal to 50% to 84% of an average Al emission intensity in an interior region of the aluminum alloy substrate in glow discharge optical emission spectroscopy in the depthwise direction from the surface of the magnetic disk substrate. The specific boundary region (D(1)I(50-84)) has a maximum Fe emission intensity (I(1)Fe(max)) higher than an average Fe emission intensity (I(1)Fe(ave)) in the interior region of the aluminum alloy substrate in the glow discharge optical emission spectroscopy.
    Type: Application
    Filed: November 28, 2018
    Publication date: February 18, 2021
    Inventors: Takuya MURATA, Kotaro KITAWAKI, Makoto YONEMITSU, Yasuo FUJII, Ryo SAKAMOTO, Hideyuki HATAKEYAMA, Sadayuki TODA
  • Publication number: 20210012801
    Abstract: Provided are a magnetic disk and a method of fabricating the magnetic disk. The magnetic disk includes an aluminum alloy plate fabricated by a process involving a CC method and a compound removal process, and an electroless Ni—P plating layer disposed on the surface of the plate. The aluminum alloy plate is composed of an aluminum alloy containing 0.4 to 3.0 mass % (hereinafter abbreviated simply as “%”) of Fe, 0.1% to 3.0% of Mn, 0.005% to 1.000% of Cu, 0.005% to 1.000% of Zn, with a balance of Al and unavoidable impurities. In the magnetic disk, the maximum amplitude of waviness in a wavelength range of 0.4 to 5.0 mm is 5 nm or less, and the maximum amplitude of waviness in a wavelength range of 0.08 to 0.45 mm is 1.5 nm or less.
    Type: Application
    Filed: November 28, 2018
    Publication date: January 14, 2021
    Inventors: Takuya MURATA, Kotaro KITAWAKI, Makoto YONEMITSU, Hideyuki HATAKEYAMA, Takashi NAKAYAMA, Ryo SAKAMOTO, Hiroki OTA
  • Publication number: 20200377984
    Abstract: Provided are: an aluminum alloy substrate for a magnetic disk, including an aluminum alloy including 0.4 to 3.0 mass % of Fe with the balance of Al and unavoidable impurities; a method for producing the aluminum alloy substrate for a magnetic disk; and a magnetic disk in which an electroless Ni—P plating treatment layer and a magnetic layer formed thereon are disposed on a surface of the aluminum alloy substrate for a magnetic disk.
    Type: Application
    Filed: February 9, 2018
    Publication date: December 3, 2020
    Inventors: Kotaro KITAWAKI, Takuya MURATA, Makoto YONEMITSU, Kouichiro TAKIGUCHI, Takashi NAKAYAMA, Kimie IMAKAWA, Yasuo FUJII, Hideyuki HATAKEYAMA
  • Publication number: 20200381015
    Abstract: Provided is an aluminum alloy substrate for a magnetic disk that includes an aluminum alloy containing 0.4 to 3.0 mass % (hereinafter abbreviated as “%”) of Fe, 0.005% to 1.000% of Cu, and 0.005% to 1.000% of Zn, with a balance of Al and unavoidable impurities. This substrate has a ratio A/B of 0.70 or more, where A indicates a distribution density of Al—Fe intermetallic compound particles having maximum diameters of 10 ?m or more and less than 16 ?m, and B indicates a distribution density of Al—Fe intermetallic compound particles having maximum diameters of 10 ?m or more. The distribution density of Al—Fe intermetallic compound particles having maximum diameters of 40 ?m or more is at most one per square millimeter. Also provided are a method of fabricating this aluminum alloy substrate for a magnetic disk and a magnetic disk composed of the aluminum alloy substrate for a magnetic disk.
    Type: Application
    Filed: February 6, 2019
    Publication date: December 3, 2020
    Inventors: Kotaro KITAWAKI, Makoto YONEMITSU, Hideyuki HATAKEYAMA, Takashi NAKAYAMA, Yasuo FUJII, Ryo SAKAMOTO
  • Publication number: 20200365180
    Abstract: There are provided: an aluminum alloy substrate for a magnetic disk, in which the product of the sheet thickness and loss factor of the substrate is 0.7×10?3 or more; a method for producing the aluminum alloy substrate for a magnetic disk; and a magnetic disk, in which an electroless Ni—P plating treatment layer and a magnetic layer formed thereon are disposed on a surface of the aluminum alloy substrate for a magnetic disk.
    Type: Application
    Filed: August 22, 2018
    Publication date: November 19, 2020
    Inventors: Kotaro KITAWAKI, Makoto YONEMITSU, Takashi NAKAYAMA, Toshihiro NAKAMURA, Ryo SAKAMOTO, Hideyuki HATAKEYAMA
  • Patent number: 10767247
    Abstract: There are provided: an aluminum alloy magnetic disk substrate including: an aluminum alloy base material including an aluminum alloy containing 0.4 to 3.0 mass % (hereinafter, simply referred to as “%”) of Fe, 0.1 to 3.0% of Mn, 0.005 to 1.000% of Cu, and 0.005 to 1.000% of Zn, with the balance of Al and unavoidable impurities; and an electroless Ni—P plated layer formed on a surface of the aluminum alloy base material, in which the peak value (BLEI) of Fe emission intensity at an interface between the electroless Ni—P plated layer and the aluminum alloy base material, as determined by a glow discharge optical emission spectrometry device, is lower than Fe emission intensity (AlEI) in the interior of the aluminum alloy base material, as determined by the glow discharge optical emission spectrometry device; and a method for producing the aluminum alloy magnetic disk substrate.
    Type: Grant
    Filed: January 30, 2018
    Date of Patent: September 8, 2020
    Assignees: UACJ Corporation, Furukawa Electric Co., Ltd.
    Inventors: Takuya Murata, Kotaro Kitawaki, Makoto Yonemitsu, Naoki Kitamura, Takashi Nakayama, Hideyuki Hatakeyama, Ryo Sakamoto, Sadayuki Toda