Patents by Inventor Shojiro Kuwahara

Shojiro Kuwahara 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: 9085647
    Abstract: A thermoplastic transparent resin which is produced by hydrogenating 70% or more of aromatic double bonds of a copolymer. The copolymer is produced by polymerizing a monomer composition containing at least one (meth)acrylic ester monomer and at least one aromatic vinyl monomer and has a molar ratio (A/B) of from 1 to 4 wherein A is a molar amount of a constitutional unit derived from the (meth)acrylic ester monomer and B is a molar amount of a constitutional unit derived from the aromatic vinyl monomer. The thermoplastic transparent resin is suitable for the production of a molded article such as optical article having a good color tone because molding defect is less produced.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: July 21, 2015
    Assignee: MITSUBISHI GAS CHEMICAL COMPANY, INC.
    Inventors: Nobuya Saegusa, Shojiro Kuwahara
  • Patent number: 8030434
    Abstract: The present invention relates to a polyester film produced by melt-extruding a polyester composed of a dicarboxylic acid unit and a diol unit, wherein 1 to 80 mol % of the diol unit is a unit containing a cyclic acetal skeleton, and the polyester film has an in-plane retardation of 20 nm or less at a wavelength of 550 nm. The polyester film is an optically isotropic polyester film which is easily produced by an extrusion-molding method and has an economical advantage. The polyester film is useful for production of optical members or optical products such as phase difference films, protective films for polarizing plates, light diffusion films, lens sheets, anti-reflection films and optical information recording media.
    Type: Grant
    Filed: January 31, 2006
    Date of Patent: October 4, 2011
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Tsuyoshi Ikeda, Koshi Koide, Nobuyuki Koike, Tadashi Kawabata, Takeshi Hirokane, Shojiro Kuwahara
  • Patent number: 7910659
    Abstract: Disclosed is an acrylic syrup containing a vinyl monomer (A) of methyl methacrylate and a polymerized solid component (B) which is a high polymer of said vinyl monomer and has a weight average molecular weight of from 30,000 to 2,000,000 as measured by the GPC and a viscosity at 25° C. of from 0.1 to 50 Pa·s, wherein at least part of said polymerized solid component (B) is a grafted rubber obtained by graft-polymerizing said vinyl monomer with a rubbery polymer, and said grafted rubber has a large branching coefficient. The acrylic resin molded articles obtained from the acrylic syrup exhibit excellent impact resistance.
    Type: Grant
    Filed: October 24, 2005
    Date of Patent: March 22, 2011
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Tadashi Kawabata, Shojiro Kuwahara, Masahiro Kurokawa
  • Publication number: 20080213606
    Abstract: A thermoplastic transparent resin which is produced by hydrogenating 70% or more of aromatic double bonds of a copolymer. The copolymer is produced by polymerizing a monomer composition containing at least one (meth)acrylic ester monomer and at least one aromatic vinyl monomer and has a molar ratio (A/B) of from 1 to 4 wherein A is a molar amount of a constitutional unit derived from the (meth)acrylic ester monomer and B is a molar amount of a constitutional unit derived from the aromatic vinyl monomer. The thermoplastic transparent resin is suitable for the production of a molded article such as optical article having a good color tone because molding defect is less produced.
    Type: Application
    Filed: May 31, 2005
    Publication date: September 4, 2008
    Inventors: Nobuya Saegusa, Shojiro Kuwahara
  • Patent number: 7192994
    Abstract: Disclosed is a method of producing a powdery coating material by using: a curable polyester resin (A) having a hydroxyl group and/or a carboxyl group at the terminals thereof, and further having a number average molecular weight of from 1,000 to 30,000, a glass transition temperature of from 30 to 100° C.; a curing agent (B) which is solid at normal temperature and is capable of being reacted with the hydroxyl group or the carboxyl group of the curable polyester resin (A); and a solvent (C) having a boiling point under normal pressure of from 50 to 130° C.; and comprising a step of kneading the curable polyester resin (A), the curing agent (B) and the solvent (C) under condition in which at 50 to 130° C., not less than 20% by weight of the curing agent (B) is dissolved in the solvent and, then, vapor-removing the solvent (C) under a reduced pressure.
    Type: Grant
    Filed: October 12, 2004
    Date of Patent: March 20, 2007
    Assignee: Mitsubishi Gas Chemical Co., Inc.
    Inventors: Nobuyuki Koike, Shojiro Kuwahara
  • Patent number: 7183362
    Abstract: In the invention, a polyester resin comprising dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process comprising an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a basic compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.
    Type: Grant
    Filed: November 29, 2004
    Date of Patent: February 27, 2007
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Takeshi Hirokane, Shojiro Kuwahara, Tsuyoshi Ikeda, Nobuya Saegusa, Tomohito Oyama
  • Patent number: 7179869
    Abstract: In the invention, a polyester resin having dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process including an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a titanium compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: February 20, 2007
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Takeshi Hirokane, Tomohito Oyama, Shojiro Kuwahara
  • Patent number: 7064169
    Abstract: Polyester resin composition (C) comprises polyester resin (A), which comprises polyester resin (l) comprising a diol unit having a cyclic acetal structure (CA) and a dicarboxylic acid unit having no CA, polyester resin (m) comprising a dicarboxylic acid unit having CA and a diol unit having no CA and/or polyester resin (n) comprising a diol unit having CA and a dicarboxylic acid unit having CA, and polyester resin (B) having no CA. The sum of the fraction of the dicarboxylic acid unit having CA in the entire dicarboxylic acid unit and the fraction of the diol unit having CA in the entire diol unit in composition (C) is 0.05% by mole or greater. The polyester resin compositions are excellent in transparency, melt viscoelasticity, heat resistance and moldability, and exhibit a samll crystallization rate.
    Type: Grant
    Filed: December 19, 2002
    Date of Patent: June 20, 2006
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Tsuyoshi Ikeda, Takeshi Hirokane, Shojiro Kuwahara
  • Patent number: 7056984
    Abstract: Disclosed is an acrylic syrup containing a vinyl monomer (A) of methyl methacrylate and a polymerized solid component (B) which is a high polymer of said vinyl monomer and has a weight average molecular weight of from 30,000 to 2,000,000 as measured by the GPC and a viscosity at 25° C. of from 0.1 to 50 Pa·s, wherein at least part of said polymerized solid component (B) is a grafted rubber obtained by graft-polymerizing said vinyl monomer with a rubbery polymer, and said grafted rubber has a large branching coefficient. The acrylic resin molded articles obtained from the acrylic syrup exhibit excellent impact resistance.
    Type: Grant
    Filed: May 15, 2002
    Date of Patent: June 6, 2006
    Assignee: Mitsubishi Gas Chemical Co., Inc.
    Inventors: Tadashi Kawabata, Shojiro Kuwahara, Masahiro Kurokawa
  • Publication number: 20060089463
    Abstract: Disclosed is an acrylic syrup containing a vinyl monomer (A) of methyl methacrylate and a polymerized solid component (B) which is a high polymer of said vinyl monomer and has a weight average molecular weight of from 30,000 to 2,000,000 as measured by the GPC and a viscosity at 25° C. of from 0.1 to 50 Pa·s, wherein at least part of said polymerized solid component (B) is a grafted rubber obtained by graft-polymerizing said vinyl monomer with a rubbery polymer, and said grafted rubber has a large branching coefficient. The acrylic resin molded articles obtained from the acrylic syrup exhibit excellent impact resistance.
    Type: Application
    Filed: October 24, 2005
    Publication date: April 27, 2006
    Inventors: Tadashi Kawabata, Shojiro Kuwahara, Masahiro Kurokawa
  • Publication number: 20050218550
    Abstract: Disclosed is a method of producing a powdery coating material by using: a curable acrylic resin (A) having a number average molecular weight of from 2,000 to 20,000 and a glass transition temperature of from 30 to 90° C. obtained by polymerizing a starting monomer containing from 15 to 50 mol % of an unsaturated compound which contains at least a glycidyl group and/or a methylglycidyl group, and from 20 to 50 mol % of methyl methacrylate; a curing agent (B) capable of being reacted with the glycidyl group or the methylglycidyl group constituting the curable acrylic resin (A); and an alcohol solvent (C) having a boiling point under normal pressure of from 70 to 120° C.; said method comprising a kneading step of so kneading the curable acrylic resin (A), the curing agent (B) and the alcohol solvent (C) that at least the curing agent (B) is dissolved in the alcohol solvent (C) at a temperature of not higher than 130° C.
    Type: Application
    Filed: June 3, 2005
    Publication date: October 6, 2005
    Inventors: Nobuyuki Koike, Shojiro Kuwahara
  • Publication number: 20050209435
    Abstract: In the invention, a polyester resin having dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process including an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a titanium compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.
    Type: Application
    Filed: March 11, 2005
    Publication date: September 22, 2005
    Inventors: Takeshi Hirokane, Tomohito Oyama, Shojiro Kuwahara
  • Patent number: 6933348
    Abstract: Disclosed is a method of producing a powdery coating material by using a curable acrylic resin (A) having a number average molecular weight of from 2,000 to 20,000 and a glass transition temperature of from 30 to 90° C. obtained by polymerizing a starting monomer containing from 15 to 50 mol % of an unsaturated compound which contains at least a glycidyl group and/or a methylglycidyl group, and from 20 to 50 mol % of methyl methacrylate; a curing agent (B) capable of being reacted with the glycidyl group or the methylglycidyl group constituting the curable acrylic resin (A); and an alcohol solvent (C) having a boiling point under normal pressure of from 70 to 120° C.; said method comprising a kneading step of so kneading the curable acrylic resin (A), the curing agent (B) and the alcohol solvent (C) that at least the curing agent (B) is dissolved in the alcohol solvent (C) at a temperature of not higher than 130°C.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: August 23, 2005
    Assignee: Mitsubishi Gas Chemical Co., Inc.
    Inventors: Nobuyuki Koike, Shojiro Kuwahara
  • Publication number: 20050176914
    Abstract: In the invention, a polyester resin comprising dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process comprising an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a basic compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.
    Type: Application
    Filed: November 29, 2004
    Publication date: August 11, 2005
    Inventors: Takeshi Hirokane, Shojiro Kuwahara, Tsuyoshi Ikeda, Nobuya Saegusa, Tomohito Oyama
  • Patent number: 6927275
    Abstract: The process of the present invention for producing a polyester resin comprising a dicarboxylic acid constitutional unit and a diol constitutional unit having a cyclic acetal skeleton comprises a step (1) of subjecting a diol (A) having a cyclic acetal skeleton and an ester (D) to transesterification reaction and a step (2) of mainly converting the resultant oligomer into a high polymer. The step (1) simultaneously satisfies the requirements (i) to (iv) as described in the specification. In the process of the present invention, the polyester resins having excellent moldability and mechanical properties are stably produced by a transesterification method which is less detrimental to environments.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: August 9, 2005
    Assignee: Mitsubishi Gas Chemical Co., Inc.
    Inventors: Takeshi Hirokane, Tsuyoshi Ikeda, Shojiro Kuwahara, Takamasa Kawashima, Tomohito Oyama
  • Publication number: 20050113490
    Abstract: Disclosed is a method of producing a powdery coating material by using: a curable polyester resin (A) having a hydroxyl group and/or a carboxyl group at the terminals thereof, and further having a number average molecular weight of from 1,000 to 30,000, a glass transition temperature of from 30 to 100° C.; a curing agent (B) which is solid at normal temperature and is capable of being reacted with the hydroxyl group or the carboxyl group of the curable polyester resin (A); and a solvent (C) having a boiling point under normal pressure of from 50 to 130° C.; and comprising a step of kneading the curable polyester resin (A), the curing agent (B) and the solvent (C) under condition in which at 50 to 130° C., not less than 20% by weight of the curing agent (B) is dissolved in the solvent and, then, vapor-removing the solvent (C) under a reduced pressure.
    Type: Application
    Filed: October 12, 2004
    Publication date: May 26, 2005
    Inventors: Nobuyuki Koike, Shojiro Kuwahara
  • Patent number: 6822022
    Abstract: Disclosed is a method of producing a powdery coating material by using: a curable polyester resin (A) having a hydroxyl group and/or a carboxyl group at the terminals thereof, and further having a number average molecular weight of from 1,000 to 30,000, a glass transition temperature of from 30 to 100° C.; a curing agent (B) which is solid at normal temperature and is capable of being reacted with the hydroxyl group or the carboxyl group of the curable polyester resin (A); and a solvent (C) having a boiling point under normal pressure of from 50 to 130° C.; and comprising a step of kneading the curable polyester resin (A), the curing agent (B) and the solvent (C) under condition in which at 50 to 130° C., not less than 20% by weight of the curing agent (B) is dissolved in the solvent and, then, vapor-removing the solvent (C) under a reduced pressure.
    Type: Grant
    Filed: March 13, 2002
    Date of Patent: November 23, 2004
    Assignee: Mitsubishi Gas Chemical INC
    Inventors: Nobuyuki Koike, Shojiro Kuwahara
  • Publication number: 20040167309
    Abstract: The monomer of the present invention is represented by the following Formula 1: 1
    Type: Application
    Filed: March 1, 2004
    Publication date: August 26, 2004
    Inventors: Nobuya Saegusa, Akihiro Honma, Hajime Yamada, Takamasa Kawashima, Shojiro Kuwahara
  • Publication number: 20040059084
    Abstract: The process of the present invention for producing a polyester resin comprising a dicarboxylic acid constitutional unit and a diol constitutional unit having a cyclic acetal skeleton comprises a step (1) of subjecting a diol (A) having a cyclic acetal skeleton and an ester (D) to transesterification reaction and a step (2) of mainly converting the resultant oligomer into a high polymer. The step (1) simultaneously satisfies the requirements (i) to (iv) as described in the specification. In the process of the present invention, the polyester resins having excellent moldability and mechanical properties are stably produced by a transesterification method which is less detrimental to environments.
    Type: Application
    Filed: September 11, 2003
    Publication date: March 25, 2004
    Inventors: Takeshi Hirokane, Tsuyoshi Ikeda, Shojiro Kuwahara, Takamasa Kawashima, Tomohito Oyama
  • Patent number: 6653440
    Abstract: In the production method of the present invention, a copolyester of intended sublimable diol proportion is produced by the reaction of a dicarboxylic acid and/or an ester-forming derivative thereof with a sublimable diol and a non-sublimable diol with an increased conversion of the sublimable diol. Since the escape of the sublimable diol is effectively prevented, the process solves the problem of clogging pressure-reduced pipes, etc. of an apparatus for polyester resin production.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: November 25, 2003
    Assignee: Mitsubishi Gas Chemical Company
    Inventors: Takeshi Hirokane, Tsuyoshi Ikeda, Shojiro Kuwahara