Patents by Inventor Yoshitsugu Hirokawa

Yoshitsugu Hirokawa 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: 10391555
    Abstract: Silver nanowires having a thin and long shape that exhibit excellent dispersibility in an aqueous solvent having an alcohol added thereto are provided by silver nanowires having an average diameter of 50 nm or less and an average length of 10 ?m or more, covered with a copolymer of a maleimide-based monomer and vinylpyrrolidone. The silver nanowires can be produced by a method for producing silver nanowires, containing reductively depositing silver in a wire form in an alcohol solvent having dissolved therein a silver compound, the deposition being performed in the solvent having dissolved therein a copolymer of a maleimide-based monomer and vinylpyrrolidone.
    Type: Grant
    Filed: January 14, 2016
    Date of Patent: August 27, 2019
    Assignees: THE UNIVERSITY OF SHIGA PREFECTURE, DOWA HOLDINGS CO., LTD.
    Inventors: Shohei Ida, Yoshitsugu Hirokawa, Jeyadevan Balachandran, Jhon Lehman Cuya Huaman, Kimitaka Sato
  • Publication number: 20180272424
    Abstract: Silver nanowires having a thin and long shape that exhibit excellent dispersibility in an aqueous solvent having an alcohol added thereto are provided by silver nanowires having an average diameter of 50 nm or less and an average length of 10 ?m or more, covered with a copolymer of a maleimide-based monomer and vinylpyrrolidone. The silver nanowires can be produced by a method for producing silver nanowires, containing reductively depositing silver in a wire form in an alcohol solvent having dissolved therein a silver compound, the deposition being performed in the solvent having dissolved therein a copolymer of a maleimide-based monomer and vinylpyrrolidone.
    Type: Application
    Filed: January 14, 2016
    Publication date: September 27, 2018
    Inventors: Shohei IDA, Yoshitsugu HIROKAWA, Jeyadevan BALACHANDRAN, Jhon Lehman Cuya HUAMAN, Kimitaka SATO
  • Patent number: 8048478
    Abstract: A method of manufacturing an electrode for an electrochemical device is provided with the steps of: supplying, onto a collector, a powdered mixture containing a binder and an active material; and heating the powdered mixture to form an electrode layer on the collector, that allows continuous mass production of electrodes for electrochemical devices.
    Type: Grant
    Filed: July 17, 2009
    Date of Patent: November 1, 2011
    Assignee: Zeon Corporation
    Inventors: Yoshitsugu Hirokawa, Hidekazu Mori, Masahiro Yamakawa
  • Publication number: 20100015328
    Abstract: A method of manufacturing an electrode for an electrochemical device is provided with the steps of: supplying, onto a collector, a powdered mixture containing a binder and an active material; and heating the powdered mixture to form an electrode layer on the collector, that allows continuous mass production of electrodes for electrochemical devices.
    Type: Application
    Filed: July 17, 2009
    Publication date: January 21, 2010
    Inventors: Yoshitsugu HIROKAWA, Hidekazu Mori, Masahiro Yamakawa
  • Publication number: 20090220847
    Abstract: A fuel container for fuel cells includes a container main body obtained by molding a resin material including a cycloolefin polymer resin into a shape which allows the container main body to store fuel, and an outlet provided in the container main body for supplying fuel to a fuel cell. The fuel container does not undergo erosion or swelling caused by a liquid organic compound such as an alcohol, and does not allow leakage of a liquid organic compound.
    Type: Application
    Filed: March 3, 2005
    Publication date: September 3, 2009
    Applicant: ZEON CORPORATION
    Inventors: Masayoshi Oshima, Yoshitsugu Hirokawa
  • Publication number: 20060153972
    Abstract: A method of manufacturing an electrode for an electrochemical device is provided with the steps of: supplying, onto a collector, a powdered mixture containing a binder and an active material; and heating the powdered mixture to form an electrode layer on the collector, that allows continuous mass production of electrodes for electrochemical devices.
    Type: Application
    Filed: February 24, 2004
    Publication date: July 13, 2006
    Inventor: Yoshitsugu Hirokawa
  • Patent number: 5399646
    Abstract: The present invention discloses an alkylidenenorbornene polymer comprising as the essential constituent at least one kind of the structural unit represented by the formula ##STR1## wherein R.sub.1 denotes an alkyl group of 1-4 carbon atoms and R.sub.2 denotes a hydrogen atom or an alkyl group of 1-5 carbon atoms, and a process for producing the same.According to the present invention, an alkylidenenorbornene polymer is obtained which is excellent in light resistance, transparency, heat resistance and moisture resistance and is useful as an optical polymeric material.
    Type: Grant
    Filed: July 16, 1993
    Date of Patent: March 21, 1995
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Teiji Kohara, Shin-ichiro Tahara, Yoshitsugu Hirokawa, Tadao Natsuume
  • Patent number: 5248746
    Abstract: A method of producing a polymer of a cationically polymerizable vinyl monomer by polymerizing at least one cationically polymerizable vinyl monomer using a polymerization initiator system composed of an organic compound having a functional group represented by formula (I) below ##STR1## where R.sup.1 represents a hydrogen atom, an alkyl group, or an aryl group; R.sup.2 represents an alkyl group, or an aryl group; X represents a halogen atom, an alkoxy group, or an acyloxy group, and a Lewis acid, wherein polymerization is carried out in the presence of a phosphorus-containing compound selected from the group consisting of a phosphine, a phosphine oxide, a phosphite, and a phosphate.
    Type: Grant
    Filed: April 2, 1991
    Date of Patent: September 28, 1993
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Yoshiharu Shimokawa, Yasuo Tsunogae, Shin-ichiro Tahara, Masami Kitaoka, Yoshitsugu Hirokawa
  • Patent number: 4982465
    Abstract: A level-variable supporting apparatus is provided, which is so constituted that: a reversible swelling and contractive substance, which, with a prescribed temperature defined as the boundary, absorbs a swelling solution and then swells at a range of temperature on one side and discharges the swelling solution and then contracts at a range of temperature on the other side, is contained in liquidtight container which is expandable and shrinkable in prescribed directions; a liquid guiding portion to supply the swelling solution to the container and discharge it from the container, and a heating means to heat the substance are provided; and the swelling and contraction of the substance due to the change in the temperature of the substance with the prescribed temperature as the boundary causes the container to expand and shrink in the prescribed directions, thus leading to the change of the supporting position of a supported object supported by the container.
    Type: Grant
    Filed: March 16, 1990
    Date of Patent: January 8, 1991
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Nobuo Nagata, Yoshitsugu Hirokawa
  • Patent number: 4732930
    Abstract: An ionic gel formed by polymerization of isopropylacrylamide in the presence of an ion-containing monomer, a crosslinking agent and a suitable liquid medium is provided. The gel is capable of drastic volume change in response to solvent composition, temperature, pH, or ion composition.
    Type: Grant
    Filed: May 20, 1985
    Date of Patent: March 22, 1988
    Assignee: Massachusetts Institute of Technology
    Inventors: Toyoichi Tanaka, Yoshitsugu Hirokawa
  • Patent number: 4677153
    Abstract: A method for modifying a rubber having unsaturated bonds, characterized by reacting said rubber with (a) an organic compound (I) having a group represented by the formula --CH.dbd.N-- and (b) an organic acid halide (II) having a group represented by the formula --COX (X is a halogen atom), in the place of a Lewis acid.
    Type: Grant
    Filed: March 25, 1986
    Date of Patent: June 30, 1987
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Shizuo Kitahara, Yoshitsugu Hirokawa, Toshihiro Fujii
  • Patent number: 4654435
    Abstract: A process for the addition reaction of an unsaturated organic compound, except a rubber, having at least one carbon-carbon double bond in a molecule, which comprises reacting the unsaturated organic compound with an organic compound having a carboxyl group and an aldehyde group in the presence of a Lewis acid.
    Type: Grant
    Filed: December 20, 1983
    Date of Patent: March 31, 1987
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Shizuo Kitahara, Yoshitsugu Hirokawa, Haruki Kawada, Toshihiro Fujii, Nagatoshi Sugi, Hiroaki Hasegawa, Akira Yoshioka
  • Patent number: 4412031
    Abstract: A modified rubber composition comprising a blend of (a) a modified rubber obtained by reaction a rubber having an unsaturated carbon linkage with an organic compound having a carboxyl group and an aldehyde group in the presence of an acid catalyst, and (b) carbon black.
    Type: Grant
    Filed: February 18, 1983
    Date of Patent: October 25, 1983
    Assignee: Nippon Zeon Co., Ltd.
    Inventors: Shizuo Kitahara, Yoshitsugu Hirokawa, Haruki Kawada, Toshihiro Fujii, Nagatoshi Sugi, Hiroaki Hasegawa, Akira Yoshioka
  • Patent number: 4412041
    Abstract: A process for modifying a rubber, which comprises reacting a rubber having an unsaturated carbon linkage with an organic compound having a carboxyl group and an aldehyde group in the presence of an acid catalyst.
    Type: Grant
    Filed: February 18, 1983
    Date of Patent: October 25, 1983
    Assignee: Nippon Zeon Co. Ltd.
    Inventors: Shizuo Kitahara, Yoshitsugu Hirokawa, Haruki Kawada, Toshihiro Fujii, Nagatoshi Sugi, Hiroaki Hasegawa, Akira Yoshioka