Patents by Inventor Kotaro Kitawaki

Kotaro Kitawaki 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: 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
  • 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
  • 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: 20210082465
    Abstract: An aluminum alloy substrate (1) for magnetic disk satisfies at least two of three inequalities of an inequality group [A] and satisfies all of four inequalities of an inequality group [B], or satisfies at least two of the three inequalities of the inequality group [A] and satisfies all of four inequalities of an inequality group [C], when a plate thickness of the disk at a position (b1) is defined as tb1, a plate thickness at a position (b2) is defined as tb2, a plate thickness at a position (b3) is defined as tb3, a plate thickness at a position (a1) is defined as ta1, a plate thickness at a position (a2) is defined as ta2, and a plate thickness at a position (a3) is defined as ta3.
    Type: Application
    Filed: September 22, 2020
    Publication date: March 18, 2021
    Inventors: Kimie IMAKAWA, Toshihiro NAKAMURA, Hideki TAKAHASHI, Keita YOSHIMURA, Wataru KUMAGAI, Naoki KITAMURA, Kotaro KITAWAKI
  • Publication number: 20210065742
    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 % (hereinafter, “%”) of Fe, less than 0.10% of Si, less than 0.10% of Mg, and the balance of Al and unavoidable impurities, in which an Al—Fe-based intermetallic compound having a longest diameter of 2 ?m or more and less than 3 ?m is dispersed at a distribution density of 1000 particles/mm2 or more, and a Mg—Si-based intermetallic compound having a longest diameter of 1 ?m or more is dispersed at a distribution density of 1 particle/mm2 or less; a method for producing the same; and a magnetic disk in which an electroless Ni—P plating treatment layer and a magnetic layer thereon are disposed on a surface of the aluminum alloy substrate for a magnetic disk.
    Type: Application
    Filed: May 15, 2018
    Publication date: March 4, 2021
    Inventors: Kotaro KITAWAKI, Hideyuki HATAKEYAMA, Takashi NAKAYAMA, Yasuo FUJII, 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: 20210008864
    Abstract: A peeling apparatus for an aluminum plate material is configured to be able to peel one or a plurality of aluminum plate materials from a stack of aluminum plate materials in which a plurality of aluminum plate materials are pressure-annealed and adhered to each other. The peeling apparatus includes a vibration transmitting section that is configured to be able to abut an outer peripheral surface of an aluminum plate material and is configured to be able to apply vibration along a stacking direction of the stack to the aluminum plate material, and a transducer that generates the vibration, and transmits the vibration to the vibration transmitting section.
    Type: Application
    Filed: September 28, 2020
    Publication date: January 14, 2021
    Applicants: FURUKAWA ELECTRIC CO., LTD., UACJ CORPORATION
    Inventors: Toshihiro NAKAMURA, Hideki TAKAHASHI, Kimie IMAKAWA, Naoki KITAMURA, Kotaro KITAWAKI, Takuya MURATA
  • 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
  • Patent number: 10755738
    Abstract: The present invention provides: an aluminum alloy substrate for magnetic discs with excellent plating surface smoothness; a manufacturing method therefor; and a magnetic disc using said aluminum alloy substrate for magnetic discs. The present invention is an aluminum alloy substrate for magnetic discs, a manufacturing method therefor, and a magnetic disc using said aluminum alloy substrate for magnetic discs, the aluminum alloy substrate being characterized in being obtained from an aluminum alloy containing Mg: 2.0-8.0 mass % (“%” below), Be: 0.00001-0.00200%, Cu: 0.003-0.150%, Zn: 0.05-0.60%, Cr: 0.010-0.300%, Si: 0.060% or less, Fe: 0.060% or less, the balance being obtained from Al and unavoidable impurities.
    Type: Grant
    Filed: May 23, 2016
    Date of Patent: August 25, 2020
    Assignees: UACJ Corporation, Furukawa Electric Co., Ltd.
    Inventors: Kotaro Kitawaki, Takuya Murata, Akira Hibino, Naoki Kitamura, Masanobu Onishi, Hideki Takahashi, Satoshi Yamazaki, Sadayuki Toda
  • Publication number: 20190390304
    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: Application
    Filed: January 30, 2018
    Publication date: December 26, 2019
    Inventors: Takuya MURATA, Kotaro KITAWAKI, Makoto YONEMITSU, Naoki KITAMURA, Takashi NAKAYAMA, Hideyuki HATAKEYAMA, Ryo SAKAMOTO, Sadayuki TODA
  • Publication number: 20190284668
    Abstract: There are provided: an aluminum alloy substrate for a magnetic disk, including 2.0 to 10.0 mass % (hereinafter, simply referred to as “%”) of Mg, 0.003 to 0.150% of Cu, 0.05 to 0.60% of Zn, 0.03 to 1.00% of Mn, and 0.00001 to 0.00200% of Be, as well as Fe restricted to 0.50% or less, Si restricted to 0.50% or less, Cr restricted to 0.30% or less, and Cl restricted to 0.005% or less, with the balance of Al and unavoidable impurities; and a method of producing the aluminum alloy substrate for a magnetic disk.
    Type: Application
    Filed: October 27, 2017
    Publication date: September 19, 2019
    Inventors: Takuya MURATA, Kotaro KITAWAKI, Makoto YONEMITSU, Naoki KITAMURA, Yasuo FUJII, Tetsu SAKAI, Hideki TAKAHASHI, Takashi MORI