Patents by Inventor Masatoshi Midorikawa

Masatoshi Midorikawa 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: 8252449
    Abstract: The present invention discloses a separator for an electrochemical element which comprises wet nonwoven fabric containing fibrillated cellulose, non-fibrillated fiber, and fibrillated heat-resistant fiber having all of a softening point, a melting point and a thermal decomposition temperature of 250° C. or higher and 700° C. or lower, and dimensional change rates of MD and CD subjected the wet nonwoven fabric to heat treatment at 250° C. for 50 hours of each ?3% to +1%.
    Type: Grant
    Filed: April 15, 2005
    Date of Patent: August 28, 2012
    Assignee: Mitsubishi Paper Mills Limited
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa
  • Patent number: 8202406
    Abstract: A porous sheet which has good balance between electrolytic solution permeability and dry-up resistance, is superior in high-rate property, and is suitable for a separator for an electrochemical element, and a manufacturing method thereof are provided. The present invention relates to a porous sheet comprising a porous substrate containing non-fibrillar fibers having an average fiber diameter of 0.01-10 ?m and a net-like structural body composed of a polymer, the net-like structural body having penetrating pores with a pore diameter of 0.01-10 ?m, wherein the net-like structural body is present at the surface and at the internal of the porous substrate and the non-fibrillar fibers having an average fiber diameter of 0.01-10 ?m and the net-like structural body are entangled; to a separator for an electrochemical element comprising the porous sheet; and to a method for manufacturing the porous sheet.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: June 19, 2012
    Assignee: Mitsubishi Paper Mills Limited
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa, Tomohiro Sato
  • Patent number: 7977260
    Abstract: The present invention provides a separator for an electric double layer capacitor comprising a porous sheet containing fibrillated heat-resistant fibers, polyester fibers having a fineness of 0.01 dtex to less than 0.10 dtex, and fibrillated cellulose, which is suitable for use as a separator for an electric double layer capacitor operating at high voltages of 3 V or more.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: July 12, 2011
    Assignee: Mitsubishi Paper Mills Limited
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa, Tomohiro Sato
  • Publication number: 20110126401
    Abstract: The present invention discloses a heat-resistant nonwoven fabric comprising a layer having heat resistance property and a layer having anti-oxidative property, wherein the heat-resistant nonwoven fabric has a puncture strength of 0.5 N or more after heat treatment at 250° C. for 50 hours; and a position of an absorption band (A) showing a maximum infrared absorbance in the region of 500 cm?1 to 3000 cm?1 of the layer having an anti-oxidative property does not change before and after applying a voltage of 2.
    Type: Application
    Filed: February 8, 2011
    Publication date: June 2, 2011
    Inventors: Takahiro TSUKUDA, Masatoshi Midorikawa
  • Publication number: 20100252426
    Abstract: A porous sheet which has good balance between electrolytic solution permeability and dry-up resistance, is superior in high-rate property, and is suitable for a separator for an electrochemical element, and a manufacturing method thereof are provided. The present invention relates to a porous sheet comprising a porous substrate containing non-fibrillar fibers having an average fiber diameter of 0.01-10 ?m and a net-like structural body composed of a polymer, the net-like structural body having penetrating pores with a pore diameter of 0.01-10 ?m, wherein the net-like structural body is present at the surface and at the internal of the porous substrate and the non-fibrillar fibers having an average fiber diameter of 0.01-10 ?m and the net-like structural body are entangled; to a separator for an electrochemical element comprising the porous sheet; and to a method for manufacturing the porous sheet.
    Type: Application
    Filed: June 13, 2008
    Publication date: October 7, 2010
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa, Tomohiro Sato
  • Publication number: 20090280308
    Abstract: The present invention provides a separator for an electric double layer capacitor comprising a porous sheet containing fibrillated heat-resistant fibers, polyester fibers having a fineness of 0.01 dtex to less than 0.10 dtex, and fibrillated cellulose, which is suitable for use as a separator for an electric double layer capacitor operating at high voltages of 3 V or more.
    Type: Application
    Filed: November 28, 2006
    Publication date: November 12, 2009
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa, Tomohiro Sato
  • Publication number: 20070287062
    Abstract: The present invention discloses a separator for an electrochemical element which comprises wet nonwoven fabric containing fibrillated cellulose, non-fibrillated fiber, and fibrillated heat-resistant fiber having all of a softening point, a melting point and a thermal decomposition temperature of 250° C. or higher and 700° C. or lower, and dimensional change rates of MD and CD subjected the wet nonwoven fabric to heat treatment at 250° C. for 50 hours of each ?3% to +1%.
    Type: Application
    Filed: April 15, 2005
    Publication date: December 13, 2007
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa
  • Publication number: 20070207693
    Abstract: The present invention discloses a heat-resistant nonwoven fabric which comprises a layer having heat resistance and a layer having an anti-oxidative property, and the heat-resistant nonwoven fabric has a pierce strength after treatment at 250° C. for 50 hours of 0.5N or more, and a position (A) of an absorptive band showing a maximum infrared absorbance at 500 cm?1 to 3000 cm?1 of the layer having an anti-oxidative property does not change before and after applying a voltage of 2.7V for 72 hours, and an absolute value of a changed rate ((C?D)/C) of a ratio (D) which is a ratio of an absorbance of (A) and an absorbance of (B) after applying the voltage, based on a ratio (C) which is a ratio of the maximum absorbance and the absorbance of (B) before applying the voltage of less than 25%.
    Type: Application
    Filed: March 11, 2005
    Publication date: September 6, 2007
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa
  • Patent number: 6905798
    Abstract: The present invention provide a separator for an electrochemical device which comprises a wet nonwoven fabric comprising one or more kinds of fibrillated organic fibers which are at least partially fibrillated into a fiber diameter of 1 ?m or less, and one or more kinds of unfibrillated organic fibers having a fineness of 0.5 dtex or less, which exhibits excellent heat resistance, electrolyte holding properties, internal short-circuit preventing property, and winding property, which results in a lowered internal resistance and prolonged life of an electrochemical device, and a method for producing the same and an electrochemical device.
    Type: Grant
    Filed: May 29, 2001
    Date of Patent: June 14, 2005
    Assignee: Mitsubishi Paper Mills Limited
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa, Mitsuo Yoshida, Toshihiro Shigematsu, Kazuchiyo Takaoka, Kenji Hyodo
  • Publication number: 20030180622
    Abstract: The present invention provide a separator for an electrochemical device which comprises a wet nonwoven fabric comprising one or more kinds of fibrillated organic fibers which are at least partially fibrillated into a fiber diameter of 1 &mgr;m or less, and one or more kinds of. unfibrillated organic fibers having a fineness of 0.5 dtex or less, which exhibits excellent heat resistance, electrolyte holding properties, internal short-circuit preventing property, and winding property, which results in a lowered internal resistance and prolonged life of an electrochemical device, and a method for producing the same and an electrochemical device.
    Type: Application
    Filed: November 27, 2002
    Publication date: September 25, 2003
    Inventors: Takahiro Tsukuda, Masatoshi Midorikawa, Mitsuo Yoshida, Toshihiro Shigematsu, Kazuchiyo Takaoka, Kenji Hyodo