Patents by Inventor Akihiro KAKEHI

Akihiro KAKEHI 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: 20240093016
    Abstract: Provided is a technique of obtaining films with higher dielectric breakdown strength at high temperatures and folding resistance. A resin composition comprises (1) a syndiotactic polystyrene resin, (2) a polyphenylene ether resin, and (3) at least one member selected from the group consisting of styrene-based thermoplastic elastomers and atactic polystyrene resins, wherein the content of the polyphenylene ether resin in the resin composition is 6 mass % or more.
    Type: Application
    Filed: October 7, 2020
    Publication date: March 21, 2024
    Applicant: Oji Holdings Corporation
    Inventors: Takumi SUEI, Kazuo IKEDA, Akihiro KAKEHI
  • Patent number: 11817272
    Abstract: In a metallized film 1, n electrode portions 20, which are metal deposition portions, are formed in parallel on one surface of a dielectric film 2 having a film width corresponding to n capacitor elements, n being an even number of 2 or more. Each electrode portion 20 is provided with a plurality of inclined margins 31 and 32, which are metal non-deposition portions extending at an angle with respect to a film width direction, at a regular interval in a film length direction. Across a center line Lc virtually extending in the film length direction at the center in the film width direction, the inclined margins 31 of the electrode portion 20 located on one side in the film width direction, and the inclined margins 32 of the electrode portion 20 located on the other side in the film width direction are inclined in opposite directions so as to be line-symmetric with respect to the center line Lc.
    Type: Grant
    Filed: August 14, 2018
    Date of Patent: November 14, 2023
    Assignee: OJI HOLDINGS CORPORATION
    Inventors: Kazuyuki Hiate, Akihiro Kakehi, Katsuyuki Moritaka, Yoshikazu Fujishiro, Masahiro Nakata
  • Patent number: 11342116
    Abstract: A polypropylene film which has a crystallite size of not more than 12.2 nm, the crystallite size being determined using Scherrer's equation from a full width at half maximum of the reflection peak from (040) plane of ? crystal measured by a wide-angle X-ray diffraction method, and a volume resistivity of not lower than 6×1014 ?·cm, the volume resistivity being calculated in accordance with equation I from a current value that is measured 1 minute after applying a voltage at a potential gradient of 200 V/?m in an environment at 100° C. Equation I: volume resistivity=[(effective electrode area)×(applied voltage)]/[(polypropylene film thickness)×(current value)].
    Type: Grant
    Filed: August 1, 2018
    Date of Patent: May 24, 2022
    Assignee: Oji Holdings Corporation
    Inventors: Michiko Sueyoshi, Akihiro Kakehi, Takeshi Tominaga, Yoshimune Okuyama
  • Publication number: 20210134531
    Abstract: In a metallized film 1, n electrode portions 20, which are metal deposition portions, are formed in parallel on one surface of a dielectric film 2 having a film width corresponding to n capacitor elements, n being an even number of 2 or more. Each electrode portion 20 is provided with a plurality of inclined margins 31 and 32, which are non-metal deposition portions extending at an angle with respect to a film width direction, at a regular interval in a film length direction. Across a center line Lc virtually extending in the film length direction at the center in the film width direction, the inclined margins 31 of the electrode portion 20 located on one side in the film width direction, and the inclined margins 32 of the electrode portion 20 located on the other side in the film width direction are inclined in opposite directions so as to be line-symmetric with respect to the center line Lc.
    Type: Application
    Filed: August 14, 2018
    Publication date: May 6, 2021
    Applicant: OJI HOLDINGS CORPORATION
    Inventors: Kazuyuki HIATE, Akihiro KAKEHI, Katsuyuki MORITAKA, Yoshikazu FUJISHIRO, Masahiro NAKATA
  • Patent number: 10910164
    Abstract: The present invention relates to a biaxially stretched polypropylene film for capacitor. The biaxially stretched polypropylene film for capacitor of the present invention can suppress an increase in tan ? and a decrease in the electrostatic capacitance even when the capacitor is used at a high voltage and an elevated temperature for a long duration.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: February 2, 2021
    Assignee: OJI HOLDINGS CORPORATION
    Inventors: Yoshimune Okuyama, Yoshikazu Fujishiro, Masahiro Nakata, Tadakazu Ishiwata, Akihiro Kakehi
  • Publication number: 20200176188
    Abstract: A polypropylene film which has a crystallite size of not more than 12.2 nm, the crystallite size being determined using Scherrer's equation from a full width at half maximum of the reflection peak from (040) plane of ? crystal measured by a wide-angle X-ray diffraction method, and a volume resistivity of not lower than 6×1014 ?·cm, the volume resistivity being calculated in accordance with equation I from a current value that is measured 1 minute after applying a voltage at a potential gradient of 200 V/?m in an environment at 100° C. Equation I: volume resistivity=[(effective electrode area)×(applied voltage)]/[(polypropylene film thickness)×(current value)].
    Type: Application
    Filed: August 1, 2018
    Publication date: June 4, 2020
    Inventors: Michiko SUEYOSHI, Akihiro KAKEHI, Takeshi TOMINAGA, Yoshimune OKUYAMA
  • Patent number: 10629375
    Abstract: A film for a capacitor having a plurality of layers, the film for capacitors satisfying the following relational expression (1): Cmo/Cmu?1.1 wherein Cmu is an oxygen gas permeability coefficient of the film for the capacitor, and Cmo is an oxygen gas permeability coefficient of an equivalent film that would be obtained if the film for the capacitor were to be formed as a uniform single layer, and having a thickness of 1 to 35 ?m.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: April 21, 2020
    Assignee: OJI HOLDINGS CORPORATION
    Inventors: Akihiro Kakehi, Tatsuji Ishida, Yoshimune Okuyama
  • Patent number: 10431380
    Abstract: Provided is a biaxially stretched polypropylene film for capacitors having a thin thickness and having excellent initial voltage resistance and excellent long-term heat resistance and voltage resistance, and also provided is a metallized polypropylene film for capacitors. The polypropylene film for capacitors is obtained by biaxially stretching a polypropylene resin, the polypropylene film having a crystallite size of 122 ? or less as determined by the Scherrer's equation from the half width of the reflection peak from (040) plane of ?-crystal measured by a wide angle X-ray diffraction method, and the polypropylene film having a value of birefringence ?Nyz with respect to a thickness direction of 7.0×10?3 or more and 10.0×10?3 or less as measured by an optical birefringence measurement.
    Type: Grant
    Filed: September 30, 2014
    Date of Patent: October 1, 2019
    Assignee: OJI HOLDINGS CORPORATION
    Inventors: Masahiro Nakata, Kazuo Ikeda, Tadakazu Ishiwata, Akihiro Kakehi, Yoshinori Matsuo, Yuichi Shishido, Shigeo Murase
  • Patent number: 10294356
    Abstract: The present invention addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which has high voltage resistance and excellent breakdown properties. The present invention also addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which can be used suitably in a high-capacity capacitor to which a high voltage is to be applied under a higher temperature, and which preferably has a small thickness. The present invention relates to a biaxially stretched polypropylene film for capacitors, wherein a polypropylene resin which constitutes the polypropylene film has a number average molecular weight of 40,000 to 100,000 inclusive and a Z average molecular weight of 950,000 to 1,500,000 includes wherein, in a molecular weight distribution curve, the value of the difference obtained by subtracting a differential distribution value at a logarithmic molecular weight Log (M) of 6.
    Type: Grant
    Filed: August 31, 2018
    Date of Patent: May 21, 2019
    Assignee: OJI HOLDINGS CORPORATION
    Inventors: Tatsuji Ishida, Masahiro Nakata, Tadakazu Ishiwata, Akihiro Kakehi, Yoshinori Matsuo, Masahiro Yoda
  • Publication number: 20180371223
    Abstract: The present invention addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which has high voltage resistance and excellent breakdown properties. The present invention also addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which can be used suitably in a high-capacity capacitor to which a high voltage is to be applied under a higher temperature, and which preferably has a small thickness. The present invention relates to a biaxially stretched polypropylene film for capacitors, wherein a polypropylene resin which constitutes the polypropylene film has a number average molecular weight of 40,000 to 100,000 inclusive and a Z average molecular weight of 950,000 to 1,500,000 includes wherein, in a molecular weight distribution curve, the value of the difference obtained by subtracting a differential distribution value at a logarithmic molecular weight Log (M) of 6.
    Type: Application
    Filed: August 31, 2018
    Publication date: December 27, 2018
    Applicant: OJI HOLDINGS CORPORATION
    Inventors: Tatsuji ISHIDA, Masahiro NAKATA, Tadakazu ISHIWATA, Akihiro KAKEHI, Yoshinori MATSUO, Masahiro YODA
  • Patent number: 10093792
    Abstract: The present invention addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which has high voltage resistance and excellent breakdown properties. The present invention also addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which can be used suitably in a high-capacity capacitor to which a high voltage is to be applied under a higher temperature, and which preferably has a small thickness. The present invention relates to a bi-axially stretched polypropylene film for capacitors, wherein a polypropylene resin which constitutes the polypropylene film has a number average molecular weight of 40,000 to 100,000 inclusive and a Z average molecular weight of 950,000 to 1,500,000 inclusive, wherein, in a molecular weight distribution curve, the value of the difference obtained by subtracting a differential distribution value at a logarithmic molecular weight Log (M) of 6.
    Type: Grant
    Filed: February 10, 2015
    Date of Patent: October 9, 2018
    Assignee: OJI HOLDINGS CORPORATION
    Inventors: Tatsuji Ishida, Masahiro Nakata, Tadakazu Ishiwata, Akihiro Kakehi, Yoshinori Matsuo, Masahiro Yoda
  • Publication number: 20180114642
    Abstract: A film for a capacitor having a plurality of layers, the film for capacitors satisfying the following relational expression (1): Cmo/Cmu?1.1 wherein Cmu is an oxygen gas permeability coefficient of the film for the capacitor, and Cmo is an oxygen gas permeability coefficient of an equivalent film that would be obtained if the film for the capacitor were to be formed as a uniform single layer, and having a thickness of 1 to 35 ?m.
    Type: Application
    Filed: April 28, 2016
    Publication date: April 26, 2018
    Inventors: Akihiro KAKEHI, Tatsuji ISHIDA, Yoshimune OKUYAMA
  • Publication number: 20180082791
    Abstract: The present invention relates to a biaxially stretched polypropylene film for capacitor. The biaxially stretched polypropylene film for capacitor of the present invention can suppress an increase in tan ? and a decrease in the electrostatic capacitance even when the capacitor is used at a high voltage and an elevated temperature for a long duration.
    Type: Application
    Filed: March 31, 2016
    Publication date: March 22, 2018
    Applicant: OJI HOLDINGS CORPORATION
    Inventors: Yoshimune OKUYAMA, Yoshikazu FUJISHIRO, Masahiro NAKATA, Tadakazu ISHIWATA, Akihiro KAKEHI
  • Publication number: 20170229243
    Abstract: Provided is a biaxiaiiy stretched polypropylene film for capacitors having a thin thickness and having excellent initial voltage resistance and excellent long-term heat resistance and voltage resistance, and also provided is a metallized polypropylene film for capacitors. The polypropylene film for capacitors is obtained by biaxiaiiy stretching a polypropylene resin, the polypropylene film having a crystallite size of 122 ? or less as determined by the Scherrer's equation from the half width of the reflection peak from (040) plane of ?-crystal measured by a wide angle X-ray diffraction method, and the polypropylene film having a value of birefringence ?Nyz with respect to a thickness direction of 7.0×10?3 or more and 10.0×10?3 or less as measured by an optical birefringence measurement.
    Type: Application
    Filed: September 30, 2014
    Publication date: August 10, 2017
    Applicant: OJI HOLDINGS CORPORATION
    Inventors: Masahiro NAKATA, Kazuo IKEDA, Tadakazu ISHAWATA, Akihiro KAKEHI, Yoshinori MATSUO, Yuichi SHISHIDO, Shigeo MURASE
  • Publication number: 20170121515
    Abstract: The present invention addresses the problem of providing a biaxially stretched polypropylene film for capacitors, winch has high voltage resistance and excellent breakdown properties. The present invention also addresses the problem of providing a biaxially stretched polypropylene film for capacitors, which can be used suitably in a high-capacity capacitor to which a high voltage is to be applied under a higher temperature, and which preferably has a small thickness. The present invention relates to a bi-axially stretched polypropylene film for capacitors, wherein a polypropylene resin which constitutes the polypropylene film has a number average molecular weight of 40,000 to 100,000 inclusive and a Z average molecular weight of 950,000 to 1,500,000 inclusive, wherein, in a molecular weight distribution curve, the value of the difference obtained by subtracting a differential distribution value at a logarithmic molecular weight Log (M) of 6.
    Type: Application
    Filed: February 10, 2015
    Publication date: May 4, 2017
    Applicant: OJI HOLDINGS CORPORATION
    Inventors: Tatsuji ISHIDA, Masahiro NAKATA, Tadakazu ISHIWATA, Akihiro KAKEHI, Yoshinori MATSUO, Masahiro YODA