Patents by Inventor Hitoshi Koizumi

Hitoshi Koizumi 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: 20240088058
    Abstract: A field effect transistor comprising: a non-doped diamond layer which has a hydrogen-terminated surface; first and second p+diamond layers which are formed on the non-doped diamond layer and sandwich a hydrogen-terminated region; a source electrode which is formed on the first p+diamond layer and is made of metal; a drain electrode which is formed on the second p+diamond layer and is made of metal; an insulating layer which is formed on the hydrogen-terminated region of the non-doped diamond layer; and a gate electrode which is formed on the insulating layer, a mutual conductance being equal to or higher than 0.5 mS/mm at room temperatures, after an X-ray is applied for an amount of 5 Mgy.
    Type: Application
    Filed: December 28, 2021
    Publication date: March 14, 2024
    Applicant: OOKUMA DIAMOND DEVICE Inc.
    Inventors: Junichi KANEKO, Hitoshi KOIZUMI, Takahiro YAMAGUCHI, Naohisa HOSHIKAWA, Hitoshi UMEZAWA, Hideaki YAMADA, Shinya OHMAGARI
  • Patent number: 11021499
    Abstract: Provided are a water-soluble triarylphosphine for a palladium catalyst, which has high selectivity in a telomerization reaction and is easily recovered with efficiency, an ammonium salt thereof, and a method for efficiently producing the same. Specifically, provided are bis(6-methyl-3-sulphophenyl)(2-methylphenyl)phosphine; a bis(6-methyl-3-sulphonatophenyl)(2-methylphenyl)phosphine diammonium salt obtained by reacting the phosphine with a tertiary amine having a total of 3 to 27 carbon atoms in groups bonded to one nitrogen atom; and a method for producing the same.
    Type: Grant
    Filed: November 7, 2018
    Date of Patent: June 1, 2021
    Assignees: KURARAY CO., LTD., HOKKO CHEMICAL INDUSTRY CO., LTD.
    Inventors: Eriko Honda, Tatsuya Yoshikawa, Tomoaki Tsuji, Hitoshi Koizumi, Kyoko Sugita, Nobumichi Kumamoto
  • Patent number: 10696701
    Abstract: Provided are a water-soluble triarylphosphine for a palladium catalyst, which has high selectivity in a telomerization reaction and can be recovered with efficiency, an ammonium salt thereof, and a method for efficiently producing the same. Specifically, provided are bis(6-methyl-3-sulphophenyl)phenylphosphine; a bis(6-methyl-3-sulphonatopheyl)phenylphosphine diammonium salt obtained by reacting the phosphine with a tertiary amine having a total of 3 to 27 carbon atoms in groups bonded to one nitrogen atom; and a method for producing the same.
    Type: Grant
    Filed: January 16, 2018
    Date of Patent: June 30, 2020
    Assignees: KURARAY CO., LTD., HOKKO CHEMICAL INDUSTRY CO., LTD.
    Inventors: Eriko Honda, Tatsuya Yoshikawa, Tomoaki Tsuji, Hitoshi Koizumi, Kyoko Sugita, Nobumichi Kumamoto
  • Publication number: 20190071460
    Abstract: Provided are a water-soluble triarylphosphine for a palladium catalyst, which has high selectivity in a telomerization reaction and is easily recovered with efficiency, an ammonium salt thereof, and a method for efficiently producing the same. Specifically, provided are bis(6-methyl-3-sulphophenyl)(2-methylphenyl)phosphine; a bis(6-methyl-3-sulphonatophenyl)(2-methylphenyl)phosphine diammonium salt obtained by reacting the phosphine with a tertiary amine having a total of 3 to 27 carbon atoms in groups bonded to one nitrogen atom; and a method for producing the same.
    Type: Application
    Filed: November 7, 2018
    Publication date: March 7, 2019
    Inventors: Eriko HONDA, Tatsuya YOSHIKAWA, Tomoaki TSUJI, Hitoshi KOIZUMI, Kyoko SUGITA, Nobumichi KUMAMOTO
  • Publication number: 20180141967
    Abstract: Provided are a water-soluble triarylphosphine for a palladium catalyst, which has high selectivity in a telomerization reaction and can be recovered with efficiency, an ammonium salt thereof, and a method for efficiently producing the same. Specifically, provided are bis(6-methyl-3-sulphophenyl)phenylphosphine; a bis(6-methyl-3-sulphonatopheyl)phenylphosphine diammonium salt obtained by reacting the phosphine with a tertiary amine having a total of 3 to 27 carbon atoms in groups bonded to one nitrogen atom; and a method for producing the same.
    Type: Application
    Filed: January 16, 2018
    Publication date: May 24, 2018
    Applicants: KURARAY CO., LTD., HOKKO CHEMICAL INDUSTRY CO., LTD.
    Inventors: Eriko HONDA, Tatsuya YOSHIKAWA, Tomoaki TSUJI, Hitoshi KOIZUMI, Kyoko SUGITA, Nobumichi KUMAMOTO
  • Publication number: 20160052948
    Abstract: Provided are a water-soluble triarylphosphine for a palladium catalyst, which has high selectivity in a telomerization reaction and is easily recovered with efficiency, an ammonium salt thereof, and a method for efficiently producing the same. Specifically, provided are bis(6-methyl-3-sulphophenyl)(2-methylphenyl)phosphine; a bis(6-methyl-3-sulphonatophenyl)(2-methylphenyl)phosphine diammonium salt obtained by reacting the phosphine with a tertiary amine having a total of 3 to 27 carbon atoms in groups bonded to one nitrogen atom; and a method for producing the same.
    Type: Application
    Filed: March 26, 2014
    Publication date: February 25, 2016
    Applicants: KURARAY CO., LTD., HOKKO CHEMICAL INDUSTRY CO., LTD.
    Inventors: Eriko HONDA, Tatsuya YOSHIKAWA, Tomoaki TSUJI, Hitoshi KOIZUMI, Kyoko SUGITA, Nobumichi KUMAMOTO
  • Publication number: 20160052947
    Abstract: Provided are a water-soluble triarylphosphine for a palladium catalyst, which has high selectivity in a telomerization reaction and can be recovered with efficiency, an ammonium salt thereof, and a method for efficiently producing the same. Specifically, provided are bis(6-methyl-3-sulphophenyl)phenylphosphine; a bis(6-methyl-3-sulphonatophenyl)phenylphosphine diammonium salt obtained by reacting the phosphine with a tertiary amine having a total of 3 to 27 carbon atoms in groups bonded to one nitrogen atom; and a method for producing the same.
    Type: Application
    Filed: March 26, 2014
    Publication date: February 25, 2016
    Applicants: KURARAY CO., LTD., HOKKO CHEMICAL INDUSTRY CO., LTD.
    Inventors: Eriko HONDA, Tatsuya YOSHIKAWA, Tomoaki TSUJI, Hitoshi KOIZUMI, Kyoko SUGITA, Nobumichi KUMAMOTO
  • Patent number: 5086373
    Abstract: An electric double layer capacitor has two polarized electrodes each comprising a porous sintered body, and two current collectors each made of an electrically conductive material composed of a base and electrically conductive fine particles mixed in the base. The current collectors are held in contact with surfaces of the polarized electrodes and enter pores of the polarized electrodes.
    Type: Grant
    Filed: August 28, 1990
    Date of Patent: February 4, 1992
    Assignee: Isuzu Motors Limited
    Inventors: Ken Kurabayashi, Yoshinobu Tsuchiya, Akio Yoshida, Hitoshi Koizumi, Yoriaki Niida
  • Patent number: 5072337
    Abstract: The polarizing electrode of an electrical double-layer capacitor cell is constituted with solid plate-like polarizing electrodes (61, 71) and paste-like polarizing electrodes (6, 7). The solid plate-like polarizing electrodes (61, 71) are counterposedly arranged by being separated with a separator (5). The paste-like polarizing electrodes (6, 7) are coated on the surfaces at the outside of the solid plate-like polarizing electrodes (61, 71). Since the paste-like polarizing electrodes (6, 7) contact also to the solid plate-like polarizing electrodes (61, 71) and the collecting electrodes (1, 2) well, the contact resistance becomes small.
    Type: Grant
    Filed: July 30, 1990
    Date of Patent: December 10, 1991
    Assignee: Isuzu Motors Limited
    Inventors: Ken Kurabayashi, Yoshinobu Tsuchiya, Akio Yoshida, Hitoshi Koizumi
  • Patent number: 5072335
    Abstract: In producing an electrical double-layer capacitor cell, when the polarizing electrode (61,71) is formed by sintering to the collecting electrode (11,21) obtained by sintering a conductive powder into plate-like form, the contact resistance between the collecting electrode (11,21) and the polarizing electrode (61,71) becomes extremely small. Thereby, the internal resistance of the electrical double-layer capacitor cell becomes small.
    Type: Grant
    Filed: July 30, 1990
    Date of Patent: December 10, 1991
    Assignee: Isuzu Motors Limited
    Inventors: Ken Kurabayashi, Yoshinobu Tsuchiya, Akio Yoshida, Hitoshi Koizumi, Yoriaki Niida