Patents by Inventor Kotaro Takita

Kotaro Takita 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: 20090098341
    Abstract: The microporous polyolefin membrane obtained by stretching a gel molding comprising a polyolefin and a membrane-forming solvent at least uniaxially, heat-setting it, removing the membrane-forming solvent, and re-stretching it at least uniaxially has a large pore diameter and excellent air permeability, mechanical strength and compression resistance.
    Type: Application
    Filed: March 29, 2006
    Publication date: April 16, 2009
    Applicant: TONEN CHEMICAL CORPORATION
    Inventors: Kotaro Takita, Norimitsu Kaimai, Teiji Nakamura, Koichi Kono
  • Publication number: 20090098449
    Abstract: The present invention provides a microporous polyolefin membrane of high permeability and novel structure, and also provides a method of producing the same, wherein its average pore size is gradually decreases from at least one membrane surface towards its center. The method of producing the microporous polyolefin membrane comprises the steps of extruding the solution, composed of 10 to 50 weight % of (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing this polyolefin and 50 to 90 weight % of a solvent, into a gel-like formed article and removing the solvent therefrom, wherein a treatment step with a hot solvent is incorporated.
    Type: Application
    Filed: December 12, 2008
    Publication date: April 16, 2009
    Applicant: Tonen Chemical Corporation
    Inventors: Hidehiko Funaoka, Kotaro Takita, Norimitsu Kaimai, Shigeaki Kobayashi, Koichi Kono
  • Publication number: 20090098465
    Abstract: A microporous membrane having excellent properties which is produced by extruding a combination of a diluent or solvent and a polyolefin resin composition comprising (a) from about 40 to about 60% of a first polyethylene resin having a weight average molecular weight of from about 2.5×105 to about 4×105 and a molecular weight distribution of from about 5 to about 100, (b) from about 20 to about 40% of a first polypropylene resin having a weight average molecular weight of from about 0.8×106 to about 1.
    Type: Application
    Filed: October 12, 2007
    Publication date: April 16, 2009
    Inventors: Shintaro Kikuchi, Kotaro Takita
  • Publication number: 20090092893
    Abstract: The invention relates to a microporous membrane which comprises polyethylene, the microporous membrane having a differential pore volume curve with an area under the curve over the range of pore diameters of from about 100 nm to about 1,000 nm that is 25% or more of a total area under the curve over the range of pore diameters of from about 10 nm to about 1,000 nm.
    Type: Application
    Filed: October 5, 2007
    Publication date: April 9, 2009
    Inventors: Kotaro Takita, Shintaro Kikuchi
  • Publication number: 20090087749
    Abstract: A microporous membrane having a structure in which its pore size distribution curve obtained by mercury intrusion porosimetry has at least two peaks, which is produced by extruding a combination of a diluent or solvent and a polyolefin resin composition comprising from about 75 to about 99% of a polyethylene resin having a weight average molecular weight of from about 2.
    Type: Application
    Filed: September 28, 2007
    Publication date: April 2, 2009
    Inventors: Kotaro Takita, Shintaro Kikuchi
  • Publication number: 20090087750
    Abstract: A microporous membrane having a structure in which its pore size distribution curve obtained by mercury intrusion porosimetry has at least two peaks, which is produced by extruding a combination of a diluent or solvent and a polyolefin resin composition comprising (a) from about 74 to about 99% of a first polyethylene resin having a weight average molecular weight of from about 2.5×105 to about 5×105 and a molecular weight distribution of from about 5 to about 100, (b) from about 1 to about 5% of a second polyethylene resin having a weight average molecular weight of from about 5×105 to about 1×106 and a molecular weight distribution of from about 5 to about 100, and (c) from 0 to about 25% of a polypropylene resin having a weight average molecular weight of from about 3×105 to about 1.
    Type: Application
    Filed: September 28, 2007
    Publication date: April 2, 2009
    Inventors: Kotaro Takita, Shintero Kikuchi
  • Publication number: 20090081543
    Abstract: A microporous polyolefin membrane having a structure in which its pore size distribution curve obtained by mercury intrusion porosimetry has at least two peaks, which is produced by extruding a melt-blend of a polyolefin composition comprising (a) high density polyethylene resin having a weight average molecular weight of from about 2.5×105 to about 5×105 and a molecular weight distribution of from about 5 to about 100, (b) polypropylene resin having a weight average molecular weight of from about 3×105 to about 1.
    Type: Application
    Filed: September 20, 2007
    Publication date: March 26, 2009
    Inventors: Kotaro Takita, Shintaro Kikuchi
  • Publication number: 20090079102
    Abstract: A method for producing a microporous polyolefin membrane by extruding a melt blend comprising a polyethylene resin, polypropylene having a mass-average molecular weight of 1×105 or more and an ethylene content of 5% by mass or less, and a membrane-forming solvent through a die, slowly cooling the resultant extrudate to form a gel-like sheet, stretching the gel-like sheet, and removing the above membrane-forming solvent, the slow-cooling speed of the extrudate being 30° C./second or less.
    Type: Application
    Filed: June 23, 2006
    Publication date: March 26, 2009
    Applicant: TONEN CHEMICAL CORPORATION
    Inventors: Kotaro Takita, Kazuhiro Yamada, Norimitsu Kaimai, Teiji Nakamura, Koichi Kono
  • Publication number: 20090072434
    Abstract: A coextrusion die for producing a multilayer film or sheet of thermoplastic materials.
    Type: Application
    Filed: September 14, 2007
    Publication date: March 19, 2009
    Inventors: Kotaro Takita, Shintaro Kikuchi, Koichi Kono
  • Patent number: 7479243
    Abstract: The present invention provides a microporous polyolefin membrane of high permeability and novel structure, and also provides a method of producing the same, wherein its average pore size is gradually decreases from at least one membrane surface towards its center. The method of producing the microporous polyolefin membrane comprises the steps of extruding the solution, composed of 10 to 50 weight % of (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing this polyolefin and 50 to 90 weight % of a solvent, into a gel-like formed article and removing the solvent therefrom, wherein a treatment step with a hot solvent is incorporated.
    Type: Grant
    Filed: August 28, 2003
    Date of Patent: January 20, 2009
    Assignee: Tonen Chemical Corporation
    Inventors: Hidehiko Funaoka, Kotaro Takita, Norimitsu Kaimai, Shigeaki Kobayashi, Koichi Kono
  • Publication number: 20090008816
    Abstract: A microporous polyolefin membrane having excellent compression resistance is obtained by stretching a gel molding comprising a polyolefin and a membrane-forming solvent, removing the membrane-forming solvent, and stretching the resultant membrane again at least uniaxially at a speed of 3%/second or more at a temperature equal to or lower than the crystal dispersion temperature +20° C.
    Type: Application
    Filed: March 28, 2006
    Publication date: January 8, 2009
    Applicant: TONEN CHEMICAL CORPORATION
    Inventors: Kotaro Takita, Kazuhiro Yamada, Norimitsu Kaimai, Teiji Nakamura, Koichi Kono
  • Publication number: 20070012617
    Abstract: A method for producing a microporous thermoplastic resin membrane comprising the steps of extruding a solution obtained by melt-blending a thermoplastic resin and a membrane-forming solvent through a die, cooling an extrudate to form a gel-like molding, removing the membrane-forming solvent from the gel-like molding by a washing solvent, and removing the washing solvent, the washing solvent having (a) a surface tension of 24 mN/m or less at a temperature of 25° C., (b) a boiling point of 100° C. or lower at the atmospheric pressure, and (c) a solubility of 600 ppm (on a mass basis) or less in water at a temperature of 16° C.; and the washing solvent remaining in the washed molding being removed by using warm water.
    Type: Application
    Filed: August 31, 2004
    Publication date: January 18, 2007
    Inventors: Sadakatsu Suzuki, Kotaro Kimishima, Kotaro Takita
  • Publication number: 20050098913
    Abstract: The present invention provides a microporous polyolefin membrane of high permeability and novel structure, and also provides a method of producing the same, wherein its average pore size is gradually decreases from at least one membrane surface towards its center. The method of producing the microporous polyolefin membrane comprises the steps of extruding the solution, composed of 10 to 50 weight % of (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing this polyolefin and 50 to 90 weight % of a solvent, into a gel-like formed article and removing the solvent therefrom, wherein a treatment step with a hot solvent is incorporated.
    Type: Application
    Filed: August 28, 2003
    Publication date: May 12, 2005
    Applicant: TONEN CHEMICAL CORPORATION
    Inventors: Hidehiko Funaoka, Kotaro Takita, Norimitsu Kaimai, Shigeaki Kobayashi, Koichi Kono
  • Publication number: 20050058823
    Abstract: A method for producing a microporous polyolefin membrane formed by fine fibrils, the membrane comprising (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing Component (A), connected to each other, and having micropores of 0.05 to 5 ?m in average pore size and crystal lamellas of Component (A) or (B) being in a specific alignment state. The method includes extruding a solution of Component (A) or (B) in a solvent into a gel-like formed article; thermally setting the article, with or without stretching, at least at the crystal dispersion temperature of Component (A) or (B), but at melting point of Component (A) or (B) plus 30° C. or lower; and removing the solvent.
    Type: Application
    Filed: October 27, 2004
    Publication date: March 17, 2005
    Applicant: Tonen Chemical Corporation
    Inventors: Hidehiko Funaoka, Kotaro Takita, Norimitsu Kaimai, Shigeaki Kobayashi, Koichi Kono
  • Patent number: 6824865
    Abstract: A microporous polyolefin membrane is formed by fine fibrils, comprising (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing component (A), connected to each other, and has micropores of 0.05 to 5 &mgr;m in average pore size and crystal lamellas of component (A) or (B) being in a specific orientation state. The membrane is produced by extruding a solution of component (A) or (B) in a solvent, into a gel-like formed article; thermally setting the article, with or without stretching, at least at the crystal dispersion temperature of component (A) or (B), but at melting point of component (A) or (B) plus 30° C. or lower; and removing the solvent.
    Type: Grant
    Filed: July 6, 2001
    Date of Patent: November 30, 2004
    Assignee: Tonen Chemical Corporation
    Inventors: Hidehiko Funaoka, Kotaro Takita, Norimitsu Kaimai, Shigeaki Kobayashi, Koichi Kono
  • Patent number: 6666969
    Abstract: The present invention provides a microporous polyolefin membrane of high permeability and novel structure, and also provides a method of producing the same, wherein its average pore size is gradually decreases from at least one membrane surface towards its center. The method of producing the microporous polyolefin membrane comprises the steps of extruding the solution, composed of 10 to 50 weight % of (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing this polyolefin and 50 to 90 weight % of a solvent, into a gel-like formed article and removing the solvent therefrom, wherein a treatment step with a hot solvent is incorporated.
    Type: Grant
    Filed: August 20, 2001
    Date of Patent: December 23, 2003
    Assignee: Tonen Chemical Corporation
    Inventors: Hidehiko Funaoka, Kotaro Takita, Norimitsu Kaimai, Shigeaki Kobayashi, Koichi Kono
  • Patent number: 6566012
    Abstract: It is an object of the present invention to provide a microporous polyolefin membrane, high in pin puncture strength, adequate in pore diameter and high in porosity, comprising (A) an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×105 or more, or (B) a composition containing an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×105 or more, and having a porosity of 30 to 95%, bubble point exceeding 980 KPa and pin puncture strength of 4,900 mN/25 &mgr;m or more. The membrane can be used as a filter or as a separator for a battery.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: May 20, 2003
    Assignee: Tonen Chemical Corporation
    Inventors: Kotaro Takita, Hidehiko Funaoka, Norimitsu Kaimai, Shigeaki Kobayashi, Koichi Kono
  • Patent number: 6245272
    Abstract: It is an object of the present invention to provide a microporous polyolefin membrane, high in elongation and porosity, low in shrinkage, and capable of improving battery characteristics, safety and productivity, when used for battery separators. The microporous polyolefin membrane of the present invention comprises (A) an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×105 or more, or (B) a composition containing an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×105 or more, and having a porosity of 45 to 95%, elongation at break of 300% or more, bubble point exceeding 980 KPa and thermal shrinkage in the TD direction of 3% or less. The present invention also provides a method for producing the above microporous polyolefin membrane.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: June 12, 2001
    Assignee: Tonen Chemical Corporation
    Inventors: Kotaro Takita, Hidehiko Funaoka, Norimitsu Kaimai, Shigeaki Kobayashi, Koichi Kono
  • Patent number: 6235432
    Abstract: The thin film of non-protonic electrolyte comprises the microporous polyolefin film impregnated with an immobilized non-protonic electrolytic solution, where the film is treated to have improved affinity for the non-protonic solution by graft polymerization of the film with a monomer which can dissolve the non-protonic electrolytic solution, coating of the film with terminal-modified polypropylene which can dissolve the non-protonic electrolytic solution or coating of the film with wax which can dissolve the non-protonic electrolytic solution. The electrolyte-immobilized liquid-film conductor comprises the microporous polyolefin film impregnated with an immobilized non-protonic electrolytic solution, where the film contains an electron-conductive substance and is treated to have improved affinity for the non-protonic solution. The thin film of non-protonic electrolyte comprising the microporous polyolefin film gives a polymer battery, such as lithium battery, when combined with an anode and cathode.
    Type: Grant
    Filed: August 11, 1998
    Date of Patent: May 22, 2001
    Assignee: Tonen Chemical Company
    Inventors: Koichi Kono, Kotaro Takita, Norimitsu Kaimai
  • Patent number: 6218053
    Abstract: The present invention provides a thin film of non-protonic electrolyte and electrolyte-immobilized liquid-film conductor, easily produced into a thin film and to have a large area, securely holding the non-protonic electrolytic solution over a wide temperature range, and showing stability for extended periods and improved mechanical strength. They comprise a polyolefin film with a solvent-resistant polyolefin as the basic component, which is impregnated with the non-protonic electrolytic solution to immobilize it. The polyolefin composition for the film contains a terminal-modified polypropylene having, in the terminal chain, a functional group showing an affinity for the solvent for the electrolytic solution for the thin film of non-protonic electrolyte, and further contains an electron-conductive substance in addition to the terminal-modified polypropylene for the electrolyte-immobilized liquid-film conductor. As a result, the polyolefin film stably holds the solvent for the electrolytic solution.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: April 17, 2001
    Assignee: Kawabi & Associates
    Inventors: Koichi Kono, Kotaro Takita, Norimitsu Kaimai