Patents by Inventor Mitsuru Higa

Mitsuru Higa 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: 10125036
    Abstract: Provided is an ion exchange membrane including an ionic vinyl alcohol polymer having a cation exchange group or an anion exchange group. The ion exchange membrane 1 includes a porous support 3 and the ionic vinyl alcohol polymer. The porous support is provided, in a thickness direction from one surface thereof, with an impregnated layer 2 at least a part of which is impregnated with the ionic vinyl alcohol polymer. The ionic vinyl alcohol polymer includes an ionic vinyl alcohol polymer having an ion exchange group selected from a cation exchange group or an anion exchange group. The ion exchange membrane has a zeta potential value (?1) at one surface and a zeta potential value (?2) at the other surface, which are represented by the formula (1). (|?1|)?|?2|)/|?1|<0.
    Type: Grant
    Filed: June 23, 2015
    Date of Patent: November 13, 2018
    Assignees: KURARAY CO., LTD., YAMAGUCHI UNIVERSITY
    Inventors: Atsushi Jikihara, Kenichi Kobayashi, Takahiro Nakashima, Mitsuru Higa
  • Patent number: 9833742
    Abstract: Provided is a cation exchange membrane having a stable ion exchange performance during usage, being excellent in basic properties such as membrane resistance and ion transportation as well as strength, and useful for electrodialysis and a method for producing the same. The cation exchange membrane is composed of a polyvinyl alcohol copolymer including an anionic group-containing anionic polymer segment and a vinyl alcohol polymer segment, and having a microphase separation structure having a domain size (X) in a range from 0 nm<X?150 nm. The method is composed of forming a membrane from a polyvinyl alcohol copolymer which is adjusted to contain salts in a proportion that the salt weight (C) relative to the polyvinyl alcohol copolymer weight (P) is [(C)/(P)] of 4.5/95.5 or lower.
    Type: Grant
    Filed: April 8, 2015
    Date of Patent: December 5, 2017
    Assignees: KURARAY CO., LTD., YAMAGUCHI UNIVERSITY
    Inventors: Takahiro Nakashima, Atsushi Jikihara, Takashi Wakui, Mitsuru Higa
  • Patent number: 9346020
    Abstract: There is provided a multilayered charge-mosaic membrane having a porous supporting layer (A), a porous intermediate layer (B) and a charge-mosaic layer (C), wherein the porous supporting layer (A), the porous intermediate layer (B) and the charge-mosaic layer (C) are located in this order; the porous supporting layer (A) and/or the porous intermediate layer (B) are made of a fiber layer containing hydrophilic fibers; a thickness of the porous intermediate layer (B) is 0.1 to 100 ?m; a porosity of the porous supporting layer (A) is larger than a porosity of the porous intermediate layer (B); the cationic and/or the anionic polymers constituting the charge-mosaic layer (C) is a polyvinyl alcohol having an ionic group. Thus, there is provided a multilayered charge-mosaic membrane having a large salt permeation flux and excellent mechanical strength.
    Type: Grant
    Filed: December 27, 2010
    Date of Patent: May 24, 2016
    Assignees: KURARAY CO., LTD., YAMAGUCHI UNIVERSITY
    Inventors: Atsushi Jikihara, Kenichi Kobayashi, Mitsuru Higa
  • Patent number: 9266069
    Abstract: There is provided an ion-exchange membrane comprising an ion-exchange layer made of a cationic polymer and/or an anionic polymer and a supporting layer, wherein the ion-exchange layer is formed on the supporting layer by printing. Such an ion-exchange membrane exhibits excellent anti-organic fouling and low membrane resistance, thereby high efficient and long-time stable electrodialysis can be achieved. Formation of the ion-exchange layer as a charge-mosaic layer consisting of the cationic polymer domains and the anionic polymer domains provides a charge-mosaic membrane exhibiting excellent electrolyte permselectivity and mechanical strength.
    Type: Grant
    Filed: April 13, 2010
    Date of Patent: February 23, 2016
    Assignees: YAMAGUCHI UNIVERSITY, KURARAY CO., LTD.
    Inventors: Mitsuru Higa, Atsushi Jikihara, Kenichi Kobayashi, Naoki Fujiwara
  • Publication number: 20150291452
    Abstract: Provided is an ion exchange membrane including an ionic vinyl alcohol polymer having a cation exchange group or an anion exchange group. The ion exchange membrane 1 includes a porous support 3 and the ionic vinyl alcohol polymer. The porous support is provided, in a thickness direction from one surface thereof, with an impregnated layer 2 at least a part of which is impregnated with the ionic vinyl alcohol polymer. The ionic vinyl alcohol polymer includes an ionic vinyl alcohol polymer having an ion exchange group selected from a cation exchange group or an anion exchange group. The ion exchange membrane has a zeta potential value (?1) at one surface and a zeta potential value (?2) at the other surface, which are represented by the formula (1). (|?1|)?|?2|)/|?1|<0.
    Type: Application
    Filed: June 23, 2015
    Publication date: October 15, 2015
    Applicants: KURARAY CO., LTD., YAMAGUCHI UNIVERSITY
    Inventors: Atsushi JIKIHARA, Kenichi KOBAYASHI, Takahiro NAKASHIMA, Mitsuru HIGA
  • Publication number: 20150209732
    Abstract: Provided is a cation exchange membrane having a stable ion exchange performance during usage, being excellent in basic properties such as membrane resistance and ion transportation as well as strength, and useful for electrodialysis and a method for producing the same. The cation exchange membrane is composed of a polyvinyl alcohol copolymer including an anionic group-containing anionic polymer segment and a vinyl alcohol polymer segment, and having a microphase separation structure having a domain size (X) in a range from 0 nm<X?150 nm. The method is composed of forming a membrane from a polyvinyl alcohol copolymer which is adjusted to contain salts in a proportion that the salt weight (C) relative to the polyvinyl alcohol copolymer weight (P) is [(C)/(P)] of 4.5/95.5 or lower.
    Type: Application
    Filed: April 8, 2015
    Publication date: July 30, 2015
    Applicants: KURARAY CO., LTD., YAMAGUCHI UNIVERSITY
    Inventors: Takahiro NAKASHIMA, Atsushi JIKIHARA, Takashi WAKUI, Mitsuru HIGA
  • Patent number: 8604133
    Abstract: A graft copolymer having a side chain graft-polymerized by atom transfer living radical polymerization (ATRP) on a main chain polymerized by organotellurium-mediated living radical polymerization (TERP), wherein the molecular weight distribution is such that Mw/Mn is 1.5 or less. The graft copolymer is also such that a main chain moiety mainly consisting of the main chain and a side chain moiety mainly consisting of the side chain have microphase-separated structures. The graft copolymer has a narrow molecular weight distribution and forms microphase-separated structures through self organization of hydrophobic and hydrophilic moieties.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: December 10, 2013
    Assignees: Toyota Jidosha Kabushiki Kaisha, Yamaguchi University
    Inventors: Shigeharu Takagi, Mitsuru Higa
  • Publication number: 20120285881
    Abstract: There is provided a multilayered charge-mosaic membrane having a porous supporting layer (A), a porous intermediate layer (B) and a charge-mosaic layer (C), wherein the porous supporting layer (A), the porous intermediate layer (B) and the charge-mosaic layer (C) are located in this order; the porous supporting layer (A) and/or the porous intermediate layer (B) are made of a fiber layer containing hydrophilic fibers; a thickness of the porous intermediate layer (B) is 0.1 to 100 ?m; a porosity of the porous supporting layer (A) is larger than a porosity of the porous intermediate layer (B); the cationic and/or the anionic polymers constituting the charge-mosaic layer (C) is a polyvinyl alcohol having an ionic group. Thus, there is provided a multilayered charge-mosaic membrane having a large salt permeation flux and excellent mechanical strength.
    Type: Application
    Filed: December 27, 2010
    Publication date: November 15, 2012
    Applicants: YAMAGUCHI UNIVERSITY, KURARAY CO., LTD
    Inventors: Atsushi Jikihara, Kenichi Kobayashi, Mitsuru Higa
  • Publication number: 20120031834
    Abstract: There is provided an ion-exchange membrane comprising an ion-exchange layer made of a cationic polymer and/or an anionic polymer and a supporting layer, wherein the ion-exchange layer is formed on the supporting layer by printing. Such an ion-exchange membrane exhibits excellent anti-organic fouling and low membrane resistance, thereby high efficient and long-time stable electrodialysis can be achieved. Formation of the ion-exchange layer as a charge-mosaic layer consisting of the cationic polymer domains and the anionic polymer domains provides a charge-mosaic membrane exhibiting excellent electrolyte permselectivity and mechanical strength.
    Type: Application
    Filed: April 13, 2010
    Publication date: February 9, 2012
    Applicants: Kuraray Co., LTD., Yamaguchi University
    Inventors: Mitsuru Higa, Atsushi Jikihara, Kenichi Kobayashi, Naoki Fujiwara
  • Publication number: 20120034481
    Abstract: There is provided a charge-mosaic membrane comprising a cationic block copolymer (P) having a vinyl alcohol polymer block (A) and a cationic-group containing polymer block (B) as components; and an anionic block copolymer (Q) having a vinyl alcohol polymer block (C) and an anionic-group containing polymer block (D) as components. Such a charge-mosaic membrane is useful as a charge-mosaic membrane for piezodialysis because it exhibits higher membrane strength and higher permselectivity and has a larger charge density and a larger salt permeation flux.
    Type: Application
    Filed: April 8, 2010
    Publication date: February 9, 2012
    Applicants: KURARAY CO., LTD., YAMAGUCHI UNIVERSITY
    Inventors: Mitsuru Higa, Atsushi Jikihara, Kenichi Kobayashi, Naoki Fujiwara
  • Patent number: 8101668
    Abstract: This invention provides a novel graft polymer that has excellent proton conductivity, is capable of regulating hydrogen permeability, methanol permeability, and the like, and can serve as a starting material for a polymer electrolyte membrane, which facilitates moisture balance control and efficient operation of a fuel cell. A polymer electrolyte membrane composed of such graft polymer is also provided. This graft polymer comprises a main chain comprising a hydroxyl group-containing polymer and a graft chain comprising a polymer containing a sulfonic acid group-containing monomer.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: January 24, 2012
    Assignees: Toyota Jidosha Kabushiki Kaisha, Yamaguchi University
    Inventors: Shigeharu Takagi, Mitsuru Higa
  • Publication number: 20100173223
    Abstract: A graft copolymer having a side chain graft-polymerized by atom transfer living radical polymerization (ATRP) on a main chain polymerized by organotellurium-mediated living radical polymerization (TERP), wherein the molecular weight distribution is such that Mw/Mn is 1.5 or less. The graft copolymer is also such that a main chain moiety mainly consisting of the main chain and a side chain moiety mainly consisting of the side chain have microphase-separated structures. The graft copolymer has a narrow molecular weight distribution and forms microphase-separated structures through self organization of hydrophobic and hydrophilic moieties.
    Type: Application
    Filed: February 14, 2006
    Publication date: July 8, 2010
    Applicants: Toyota Jidosha Kabushiki Kaisha, Yamaguchi University
    Inventors: Shigeharu Takagi, Mitsuru Higa
  • Publication number: 20080176966
    Abstract: This invention provides a novel graft polymer that has excellent proton conductivity, is capable of regulating hydrogen permeability, methanol permeability, and the like, and can serve as a starting material for a polymer electrolyte membrane, which facilitates moisture balance control and efficient operation of a fuel cell. A polymer electrolyte membrane composed of such graft polymer is also provided. This graft polymer comprises a main chain comprising a hydroxyl group-containing polymer and a graft chain comprising a polymer containing a sulfonic acid group-containing monomer.
    Type: Application
    Filed: March 15, 2006
    Publication date: July 24, 2008
    Inventors: Shigeharu Takagi, Mitsuru Higa