Patents by Inventor Yoshiji HASHIMOTO

Yoshiji HASHIMOTO 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).

  • Aluminum alloy plate for magnetic disc substrate, method for manufacturing same, and method for manufacturing magnetic disc
    Patent number: 9613648
    Abstract: An aluminum alloy plate for a magnetic disk substrate with a flat and smooth ground surface, a production method by which the aluminum alloy plate can be produced at low cost and a magnetic disk are shown. An aluminum alloy plate for a magnetic disk substrate which comprises an aluminum alloy containing Mg: 3.0 to 8.0 mass % (hereinafter %), Cu: 0.005 to 0.150%, Zn: 0.05 to 0.60%, Cr: 0.010 to 0.300%, Fe: 0.001 to 0.030%, Si: 0.001 to 0.030%, (Ti+V+Zr): 0.0010 to 0.0100%, B: 0.0001 to 0.0010% with a balance being Al and inevitable impurities, wherein the density of a Ti—V—B—Zr-based inclusion having a maximum diameter exceeding 5 ?m is 0 piece/6000 mm2 and the density of a Ti—V—B—Zr-based inclusion having a maximum diameter of 3 to 5 ?m is 1 piece/6000 mm2 or less; a production method thereof; and a method for producing a magnetic disk.
    Type: Grant
    Filed: September 24, 2015
    Date of Patent: April 4, 2017
    Assignee: UACJ Corporation
    Inventors: Kotaro Kitawaki, Minoru Hayashi, Yoshiji Hashimoto, Toshikazu Hisamoto
  • ALUMINUM ALLOY PLATE FOR MAGNETIC DISC SUBSTRATE, METHOD FOR MANUFACTURING SAME, AND METHOD FOR MANUFACTURING MAGNETIC DISC
    Publication number: 20160351224
    Abstract: An aluminum alloy plate for a magnetic disk substrate with a flat and smooth ground surface, a production method by which the aluminum alloy plate can be produced at low cost and a magnetic disk are shown. An aluminum alloy plate for a magnetic disk substrate which comprises an aluminum alloy containing Mg: 3.0 to 8.0 mass % (hereinafter %), Cu: 0.005 to 0.150%, Zn: 0.05 to 0.60%, Cr: 0.010 to 0.300%, Fe: 0.001 to 0.030%, Si: 0.001 to 0.030%, (Ti+V+Zr): 0.0010 to 0.0100%, B: 0.0001 to 0.0010% with a balance being Al and inevitable impurities, wherein the density of a Ti—V—B—Zr-based inclusion having a maximum diameter exceeding 5 ?m is 0 piece/6000 mm2 and the density of a Ti—V—B—Zr-based inclusion having a maximum diameter of 3 to 5 ?m is 1 piece/6000 mm2 or less; a production method thereof; and a method for producing a magnetic disk.
    Type: Application
    Filed: September 24, 2015
    Publication date: December 1, 2016
    Applicant: UACJ Corporation
    Inventors: Kotaro KITAWAKI, Minoru HAYASHI, Yoshiji HASHIMOTO, Toshikazu HISAMOTO