Patents by Inventor Keizo Kawahara

Keizo Kawahara 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: 9931822
    Abstract: A polyester film made from two kinds of polyester resins and having a specific DSC (and a specific glass transition point) is provided, (i) which is superior in mechanical property, capable of thermocompression bonding with a metal sheet, despite a high degree of crystallization of the film, reduces quality change of plastic film laminated on the metal sheet even if faced with variation of conditions of thermocompression bonding with the metal sheet, and which is capable of thermocompression bonding even at a relatively low temperature, (ii) which is superior in formability, (iii) which is superior in flavoring property and impact resistance, and which obliterates occurrence of whitening or delamination of the film, or microcracks on the film, even if the film in the metal laminated sheet obtained by thermocompression bonding of the film on the metal sheet or on the surface of a metal can obtained by subjecting the metal laminated sheet to various form processings is crystallized, and (iv) which satisfies pro
    Type: Grant
    Filed: September 20, 2004
    Date of Patent: April 3, 2018
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Keizo Kawahara, Katsuya Ito, Kazutake Okamoto, Hideki Shimizu, Hiroshi Nagano, Mitsuo Inoue, Shoichi Gyobu
  • Patent number: 8314203
    Abstract: This polyimide film is superior in heat resistance, rigidity and high frequency properties, is free of inconveniences due to curling even when various functional layers are laminated by heating, and is preferable as a substrate film superior in thermal degradation stability for electronic parts. This polyimide film has a planar orientation coefficient of 0.79-0.89 as measured by an X-ray diffraction method, a difference in the surface planar orientation degree between one surface thereof and the other surface thereof of not more than 2 and a curling degree of not more than 5%, which is obtained by imidation of a polyimide precursor film having a particular imidation rate.
    Type: Grant
    Filed: December 27, 2004
    Date of Patent: November 20, 2012
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Masayuki Tsutsumi, Satoshi Maeda, Keizo Kawahara, Takefumi Yoshida, Kazutake Okamoto, Morio Morino, Shoichi Uemura, Akinobu Nagara, Noriko Takahashi, Hiroko Oyama, Shunji Kurahara, Jun Yasui
  • Patent number: 8167600
    Abstract: An apparatus and method suitable for producing a polymer film, particularly a polyimide film, perform drying and heat treatment using a tenter type feeding apparatus that suppresses the problems of deformation of film in the vicinity of pore into which the pins bite and breakage of the pores to form long pores in the width direction. The apparatus includes a device to suppress deformation of the film in the vicinity of the tenter pins at the time point when the both ends of the film is pierced with the pins and cools the pin temperature to less than 180° C. at the time when the film is pierced with the pins. Individual pins can be arranged on the innermost side of the pin sheets so that they are all disposed at the same distance both in the film feeding direction in the individual pin sheets and between other pin sheets.
    Type: Grant
    Filed: April 26, 2006
    Date of Patent: May 1, 2012
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Shinji Fujita, Shoichi Uemura, Masaharu Hiki, Youichiro Nakagawa, Kiyoshi Taniguchi, Keizo Kawahara, Satoshi Maeda
  • Patent number: 7544414
    Abstract: An oriented syndiotactic polystyrene-based film composed of an oriented film made of a syndiotactic styrene polymer and an adhesiveness-improving layer formed from a specific water-dispersible resin on at least one surface of the oriented film, which is excellent in the tight adhesion between the oriented film and the adhesiveness-improving layer, the adhesion between the adhesiveness-improving layer and an ink layer or laminate layer applied thereon, economical efficiency, recyclability, and environmental compatibility in production. It is particularly preferable that the film be produced by applying the aqueous dispersion of the water-dispersible resin on unstretched or uniaxially stretched film to form the adhesiveness-improving layer, stretching the obtained laminate uni- or bi-axially at least one time, and then heat-treating the resulting laminate.
    Type: Grant
    Filed: May 16, 2003
    Date of Patent: June 9, 2009
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Masayuki Tsutsumi, Hisato Kobayashi, Keizo Kawahara, Shigeto Yoshida, Shinsuke Yamaguchi, Kazutake Okamoto, Akira Takahashi, Eiji Kumagai, Akinobu Nagara, Yoshiko Akitomo, Kazumoto Imai, Naonobu Oda
  • Publication number: 20090056995
    Abstract: The adhesive sheet contains a substrate film and an adhesive layer formed at least on one surface of the substrate film. The substrate film is made of a polyimide film showing a degree of curl after a heat treatment at 300° C. of not more than 10%. The adhesive sheet of the present invention can be used for electronic parts and the like exposed to high temperature particularly because warpage and distortion thereof caused by a high temperature treatment are suppressed, and can improve quality and yield of electronic parts and the like.
    Type: Application
    Filed: July 1, 2005
    Publication date: March 5, 2009
    Applicant: Toyo Boseki Kabushiki Kasiha
    Inventors: Satoshi Maeda, Keizo Kawahara, Masayuki Tsutsumi, Takefumi Yoshida
  • Publication number: 20090056981
    Abstract: The thin film-laminated polyimide film contains a substrate film and a thin film layer formed at least on one surface of the substrate film. The substrate film is made of a polyimide film showing a degree of curl after a heat treatment at 300° C. of not more than 10%. Use of this thin film-laminated polyimide film as a substrate of electronic parts such as solar battery, capacitor and the like exposed to high temperatures prevents easy development of warpage and distortion during production, and can improve quality and yield of electronic parts.
    Type: Application
    Filed: July 1, 2005
    Publication date: March 5, 2009
    Applicant: Toyo Boseki Kabushiki Kaisha
    Inventors: Satoshi Maeda, Keizo Kawahara, Masayuki Tsutsumi, Takefumi Yoshida
  • Publication number: 20090032992
    Abstract: An apparatus and method suitable for producing a polymer film, particularly a polyimide film, perform drying and heat treatment using a tenter type feeding apparatus that suppresses the problems of deformation of film in the vicinity of pore into which the pins bite and breakage of the pores to form long pores in the width direction. The apparatus includes a device to suppress deformation of the film in the vicinity of the tenter pins at the time point when the both ends of the film is pierced with the pins and cools the pin temperature to less than 180° C. at the time when the film is pierced with the pins. Individual pins can be arranged on the innermost side of the pin sheets so that they are all disposed at the same distance both in the film feeding direction in the individual pin sheets and between other pin sheets.
    Type: Application
    Filed: April 26, 2006
    Publication date: February 5, 2009
    Applicant: Toyo Boseki Kabushiki Kaisha
    Inventors: Shinji Fujita, Shoichi Uemura, Masaharu Hiki, Youichiro Nakagawa, Kiyoshi Taniguchi, Keizo Kawahara, Satoshi Maeda
  • Publication number: 20070293588
    Abstract: A curable resin composition that forms a continuous phase and a dispersoid at normal temperatures, wherein the continuous phase is a liquid at normal temperatures and comprises (a) an epoxy compound having two or more epoxy groups in a molecule, and the dispersoid comprises (b) a compound present as solid particles in a continuous phase at normal temperatures and having two or more amino groups in a molecule (preferably, an aromatic amine compound having a benzoxazole structure). The present invention provides a one-component epoxy curable composition superior in the preservation stability and showing good properties of the cured product.
    Type: Application
    Filed: December 14, 2004
    Publication date: December 20, 2007
    Applicant: TOYO BOSEKI KABUSHIKI KAISHA
    Inventors: Takefumi Yoshida, Masayuki Tsutsumi, Satoshi Maeda, Keizo Kawahara
  • Publication number: 20070272124
    Abstract: This polyimide film is superior in heat resistance, rigidity and high frequency properties, is free of inconveniences due to curling even when various functional layers are laminated by heating, and is preferable as a substrate film superior in thermal degradation stability for electronic parts. This polyimide film has a planar orientation coefficient of 0.79-0.89 as measured by an X-ray diffraction method, a difference in the surface planar orientation degree between one surface thereof and the other surface thereof of not more than 2 and a curling degree of not more than 5%, which is obtained by imidation of a polyimide precursor film having a particular imidation rate.
    Type: Application
    Filed: December 27, 2004
    Publication date: November 29, 2007
    Applicant: Toyo Boseki Kabushiki Kaisha
    Inventors: Masayuki Tsutsumi, Satoshi Maeda, Keizo Kawahara, Takefumi Yoshida, Kazutake Okamoto, Morio Morino, Shoichi Uemura, Akinobu Nagara, Noriko Takahashi, Hiroko Oyama, Shunji Kurahara, Jun Yasui
  • Publication number: 20060138042
    Abstract: The present invention is a heat-resistant film comprising at least any one of a polybenzazole, aramid and polyamideimide produced by introducing a thin film made by a roll, slit or press from a polymer solution sandwiched between at least two supports into a coagulating bath and peeling the supports off in the coagulating bath to effect the coagulation, and a composite ion-exchange membrane having a surface layer consisting of an ion-exchange resin excluding a porous film on the both side of a composite layer formed by impregnating said film with the ion-exchange resin. A heat-resistant film having a combination of excellent heat resistance, mechanical strength, smoothness and interlaminar peeling resistance, especially a microporous heat-resistant film, and a composite ion-exchange membrane employing the same which has an excellent ion conductivity are provided.
    Type: Application
    Filed: October 23, 2003
    Publication date: June 29, 2006
    Inventors: Kazutake Okamoto, Hisato Kobayashi, Keizo Kawahara, Shiro Hamamoto, Satoshi Takase, Yoshimitsu Sakaguchi, Cyuji Inukai, Jun Yamada, Daisuke Sakura, Muneatsu Nakamura
  • Publication number: 20060035096
    Abstract: An oriented syndiotactic polystyrene-based film composed of an oriented film made of a syndiotactic styrene polymer and an adhesiveness-improving layer formed from a specific water-dispersible resin on at least one surface of the oriented film, which is excellent in the tight adhesion between the oriented film and the adhesiveness-improving layer, the adhesion between the adhesiveness-improving layer and an ink layer or laminate layer applied thereon, economical efficiency, recyclability, and environmental compatibility in production. It is particularly preferable that the film be produced by applying the aqueous dispersion of the water-dispersible resin on unstretched or uniaxially stretched film to form the adhesiveness-improving layer, stretching the obtained laminate uni- or bi-axially at least one time, and then heat-treating the resulting laminate.
    Type: Application
    Filed: May 16, 2003
    Publication date: February 16, 2006
    Inventors: Masayuki Tsutsumi, Hisato Kobayashi, Keizo Kawahara, Shigeto Yoshida, Shinsuke Yamaguchi, Kazutaka Okamoto, Akira Takahashi, Eiji Kumagai, Akinobu Nagara, Yoshiko Akitomo, Kazumoto Imai, Naonobu Oda
  • Publication number: 20050053796
    Abstract: A polyester film made from two kinds of polyester resins and having a specific DSC (and a specific glass transition point) is provided, (i) which is superior in mechanical property, capable of thermocompression bonding with a metal sheet, despite a high degree of crystallization of the film, reduces quality change of plastic film laminated on the metal sheet even if faced with variation of conditions of thermocompression bonding with the metal sheet, and which is capable of thermocompression bonding even at a relatively low temperature, (ii) which is superior in formability, (iii) which is superior in flavoring property and impact resistance, and which obliterates occurrence of whitening or delamination of the film, or microcracks on the film, even if the film in the metal laminated sheet obtained by thermocompression bonding of the film on the metal sheet or on the surface of a metal can obtained by subjecting the metal laminated sheet to various form processings is crystallized, and (iv) which satisfies pro
    Type: Application
    Filed: September 20, 2004
    Publication date: March 10, 2005
    Applicant: Toyo Boseki Kabushiki Kaisha
    Inventors: Keizo Kawahara, Katsuya Ito, Kazutake Okamoto, Hideki Shimizu, Hiroshi Nagano, Mitsuo Inoue, Shoichi Gyobu
  • Patent number: 6558870
    Abstract: A water-washable photosensitive flexo plate capable of reproducing images of a level as defined by a halftone resolution of 1% to 95% at 200 lines/inch, a minimum isolated dot having a diameter of 100 &mgr;m, and by a minimum isolated line having a width of 30 &mgr;m.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: May 6, 2003
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Keizo Kawahara, Yasuyuki Okazaki, Hiroshi Satomi, Tohru Wada
  • Publication number: 20020102419
    Abstract: A polyester film made from two kinds of polyester resins and having a specific DSC (and a specific glass transition point) is provided, (i) which is superior in mechanical property, capable of thermocompression bonding with a metal sheet, despite a high degree of crystallization of the film, reduces quality change of plastic film laminated on the metal sheet even if faced with variation of conditions of thermocompression bonding with the metal sheet, and which is capable of thermocompression bonding even at a relatively low temperature, (ii) which is superior in formability, (iii) which is superior in flavoring property and impact resistance, and which obliterates occurrence of whitening or delamination of the film, or microcracks on the film, even if the film in the metal laminated sheet obtained by thermocompression bonding of the film on the metal sheet or on the surface of a metal can obtained by subjecting the metal laminated sheet to various form processings is crystallized, and (iv) which satisfies pro
    Type: Application
    Filed: September 5, 2001
    Publication date: August 1, 2002
    Applicant: Toyo Boseki Kabushiki Kaisha
    Inventors: Keizo Kawahara, Katsuya Ito, Kazutake Okamoto, Hideki Shimizu, Hiroshi Nagano, Mitsuo Inoue, Shoichi Gyobu
  • Publication number: 20010005569
    Abstract: Printing plate stock comprising a base, a photosensitive resin layer overlying the base, and a covering layer overlying the photosensitive resin layer, characterized in that said photosensitive resin layer comprises (i) a matrix phase comprising a hydrophobic polymer, and (ii) a dispersed phase, surrounded by said matrix phase, comprised of particles, wherein each of said particles comprises a hydrophobic polymer surrounded by a hydrophilic polymer, wherein said hydrophilic polymer is 5-30% wt of said photosensitive resin layer.
    Type: Application
    Filed: December 7, 2000
    Publication date: June 28, 2001
    Inventors: Masaru Nanpei, Akira Tomita, Keizo Kawahara, Toshihiko Kajima
  • Patent number: 5424172
    Abstract: A photosensitive resin composition includes (A) a hydrophobic polymer having a glass transition temperature not greater than 5.degree. C., (B) a hydrophilic polymer, (C) an ethylenically unsaturated compound, (D) a solvent capable of dissolving the component (B) more than the component (A) and (E) a photopolymerization initiator, with the content of component (B) being less than that of component (A). The resin composition can be used to prepare a printing plate having a base, a photosensitive resin layer and a covering layer arranged one over another. The photosensitive resin layer contains a dispersed phase which includes particles having a phase which includes a hydrophobic polymer, surrounded by a phase which includes a hydrophilic polymer. The photosensitive resin layer can be prepared by removing the solvent (D) to a content of 0.001-2% by weight.
    Type: Grant
    Filed: July 20, 1992
    Date of Patent: June 13, 1995
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Masaru Nanpei, Akira Tomita, Keizo Kawahara, Toshihiko Kajima
  • Patent number: 5372913
    Abstract: A photosensitive resin composition includes (A) a hydrophobic polymer having a glass transition temperature not greater than 5.degree. C., (B) a hydrophilic polymer, (C) an ethylenically unsaturated compound, (D) a solvent capable of dissolving the component (B) more than the component (A) and (E) a photopolymerization initiator, with the content of component (B) being less than that of component (A). The resin composition can be used to prepare a printing plate having a base, a photosensitive resin layer and a covering layer arranged one over another. The photosensitive resin layer contains a dispersed phase which includes particles having a phase which includes a hydrophobic polymer, surrounded by a phase which includes a hydrophilic polymer. The photosensitive resin layer can be prepared by removing the solvent (D) to a content of 0.001-2% by weight.
    Type: Grant
    Filed: August 19, 1992
    Date of Patent: December 13, 1994
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Masaru Nanpei, Akira Tomita, Keizo Kawahara, Toshihiko Kajima
  • Patent number: 5124736
    Abstract: Disclosed herein are a process and apparatus for developing photopolymer plates which are useful for flexographic printing on account of their rubber-like elasticity, capability for development by water washing, and good ink resistance. The process and apparatus are designed to circulate by force the washout solution during the development operation in order to minimize the aggregation of photopolymer particles suspending in the washout solution and to completely catch scum which occurs when the unexposed part of the polymer plate is rubbed off in the washout solution.
    Type: Grant
    Filed: November 30, 1990
    Date of Patent: June 23, 1992
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Katsumasa Yamamoto, Kyoichi Mizuno, Kosaku Onodera, Keizo Kawahara, Masaru Nanpei
  • Patent number: 4946752
    Abstract: A photosensitive resin composition for a flexographic printing plate which comprises:(A) a polymer having a chlorine content of 10 to 50% by weight and a glass transition temperature of not higher than 5.degree. C. provided that the polymer is other than that of a conjugated diene hydrocarbon and a copolymer thereof;(B) a hydrophilic polymer;(C) an ethylenic unsaturated compound; and(D) a photopolymerization initiator.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: August 7, 1990
    Assignee: Toyo Boseki Kabushiki Kaisha
    Inventors: Akira Tomita, Toshihiko Kajima, Keizo Kawahara, Hiroshi Satomi