Patents by Inventor Rikio Yokota

Rikio Yokota 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: 20230193075
    Abstract: The present invention provides an amide acid oligomer which has specific composition and which is capable of providing a cured product having excellent physical properties, in particular, an excellent glass transition temperature, etc.
    Type: Application
    Filed: March 5, 2021
    Publication date: June 22, 2023
    Applicants: KANEKA CORPORATION, JAPAN AEROSPACE EXPLORATION AGENCY
    Inventors: Takefumi Furuta, Yoshio Furukawa, Rikio Yokota, Yuichi Ishida
  • Publication number: 20230042415
    Abstract: The present invention provides an amide acid oligomer which has specific composition and which is capable of providing a cured product having excellent physical properties, in particular, an excellent glass transition temperature, etc.
    Type: Application
    Filed: September 29, 2022
    Publication date: February 9, 2023
    Applicants: KANEKA CORPORATION, JAPAN AEROSPACE EXPLORATION AGENCY
    Inventors: Takefumi Furuta, Yoshio Furukawa, Rikio Yokota, Yuichi Ishida
  • Patent number: 11492446
    Abstract: An object of the present invention is to reduce or eliminate a defect (e.g., a void) by achieving (i) a semipreg and a prepreg each of which allows a reduction in residual volatile component and (ii) methods for producing the semipreg and the prepreg, respectively, and consequently to achieve (iii) a fiber-reinforced composite material which has high heat resistance and superior mechanical strength and a (iv) a method for producing the fiber-reinforced composite material. The present invention attains the above object by providing, for example, a semipreg containing: powders of an imide oligomer; and reinforcement fibers, the imide oligomer being represented by a specific general formula (1).
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: November 8, 2022
    Assignees: KANEKA CORPORATION, JAPAN AEROSPACE EXPLORATION AGENCY
    Inventors: Yoshio Furukawa, Takefumi Furuta, Takeshi Chiba, Rikio Yokota, Yuichi Ishida
  • Publication number: 20210340327
    Abstract: In order to provide an imide oligomer or the like which can give a cured product exhibiting excellent thermal oxidative stability, an imide oligomer is obtained by reacting together an aromatic tetracarboxylic acid component, an aromatic diamine component, and a terminal capping agent. The imide oligomer contains, in a specified proportion: a compound containing a phenylethynyl group; and a compound containing no carbon-carbon unsaturated bond capable of an addition reaction. One or each of the aromatic tetracarboxylic acid component and the aromatic diamine component contains a component having an asymmetrical and non-planar structure.
    Type: Application
    Filed: July 14, 2021
    Publication date: November 4, 2021
    Applicant: KANEKA CORPORATION
    Inventors: Takefumi Furuta, Yoshio Furukawa, Rikio Yokota, Yuki Kubota, Yuichi Ishida
  • Patent number: 10815390
    Abstract: An imide resin composition including a terminal-modified imide oligomer of General Formula (1) and a thermoplastic aromatic polyimide of General Formula (2). (In Formula (1), either R1 or R2 shows a phenyl group and the other shows a hydrogen atom; R3 and R4 show a divalent residue of aromatic diamine; R5 and R6 show a tetravalent residue of aromatic tetracarboxylic acid; m and n satisfy relationships of m?1, n?0, 1?m+n?20, and 0.05?m/(m+n)?1; and an arrangement of repeating units may be either a block or random.) (In Formula (2), R1 and R2 show a divalent residue of aromatic diamine; R3 shows a tetravalent residue of aromatic tetracarboxylic acid; m and n satisfy relationships of m?1 and n?0, and an arrangement of repeating units may be either a block or random.
    Type: Grant
    Filed: June 4, 2018
    Date of Patent: October 27, 2020
    Assignees: Kaneka Corporation, Japan Aerospace Exploration Agency
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Publication number: 20200148846
    Abstract: An object of the present invention is to reduce or eliminate a defect (e.g., a void) by achieving (i) a semipreg and a prepreg each of which allows a reduction in residual volatile component and (ii) methods for producing the semipreg and the prepreg, respectively, and consequently to achieve (iii) a fiber-reinforced composite material which has high heat resistance and superior mechanical strength and a (iv) a method for producing the fiber-reinforced composite material. The present invention attains the above object by providing, for example, a semipreg containing: powders of an imide oligomer; and reinforcement fibers, the imide oligomer being represented by a specific general formula (1).
    Type: Application
    Filed: March 22, 2018
    Publication date: May 14, 2020
    Applicants: KANEKA CORPORATION, JAPAN AEROSPACE EXPLORATION AGENCY
    Inventors: Yoshio FURUKAWA, Takefumi FURUTA, Takeshi CHIBA, Rikio YOKOTA, Yuichi ISHIDA
  • Patent number: 10526450
    Abstract: A terminally modified imide oligomer is represented by a specific formula including a 2-phenyl-4,4?-diaminodiphenylether residue or a 4-phenoxy-1,3-diaminobenzene residue. A varnish is obtained by dissolving the terminally modified imide oligomer. A cured product is obtained by heat-curing the terminally modified imide oligomer, and a film including the cured product has a tensile elongation at break of 10% or more. An imide prepreg is obtained by impregnating fibers with the varnish and then drying the impregnated fibers. A fiber-reinforced composite material is obtained by layering and then heat-curing the imide prepreg.
    Type: Grant
    Filed: November 8, 2018
    Date of Patent: January 7, 2020
    Assignee: KANEKA CORPORATION
    Inventors: Takefumi Furuta, Masahiko Miyauchi, Rikio Yokota, Yuichi Ishida
  • Publication number: 20190071541
    Abstract: A terminally modified imide oligomer is represented by a specific formula including a 2-phenyl-4,4?-diaminodiphenylether residue or a 4-phenoxy-1,3-diaminobenzene residue. A varnish is obtained by dissolving the terminally modified imide oligomer. A cured product is obtained by heat-curing the terminally modified imide oligomer, and a film including the cured product has a tensile elongation at break of 10% or more. An imide prepreg is obtained by impregnating fibers with the varnish and then drying the impregnated fibers. A fiber-reinforced composite material is obtained by layering and then heat-curing the imide prepreg.
    Type: Application
    Filed: November 8, 2018
    Publication date: March 7, 2019
    Applicant: KANEKA CORPORATION
    Inventors: Takefumi Furuta, Masahiko Miyauchi, Rikio Yokota, Yuichi Ishida
  • Publication number: 20180273798
    Abstract: An imide resin composition including a terminal-modified imide oligomer of General Formula (1) and a thermoplastic aromatic polyimide of General Formula (2). (In Formula (1), either R1 or R2 shows a phenyl group and the other shows a hydrogen atom; R3 and R4 show a divalent residue of aromatic diamine; R5 and R6 show a tetravalent residue of aromatic tetracarboxylic acid; m and n satisfy relationships of m?1, n?0, 1?m+n?20, and 0.05?m/(m+n)?1; and an arrangement of repeating units may be either a block or random.) (In Formula (2), R1 and R2 show a divalent residue of aromatic diamine; R3 shows a tetravalent residue of aromatic tetracarboxylic acid; m and n satisfy relationships of m?1 and n?0, and an arrangement of repeating units may be either a block or random.
    Type: Application
    Filed: June 4, 2018
    Publication date: September 27, 2018
    Applicants: Japan Aerospace Exploration Agency
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Patent number: 10047246
    Abstract: Provided is a varnish including 1 to 500 parts by weight of an aromatic tetracarboxylic acid diester (A) represented by General Formula (1), 1 to 450 parts by weight of 2-phenyl-4,4?-diaminodiphenyl ether (B), 1 to 100 parts by weight of a 4-(2-phenylethynyl)phthalic acid monoester (C) represented by General Formula (2), and 100 parts by weight of an organic solvent having a boiling point of 150° C. or less at 1 atmosphere or a mixture of two or more of the organic solvents (D). The components (A), (B), and (C) are dissolved in the varnish. (In the formula, R1 is an aromatic tetracarboxylic acid diester residue; R2 and R3 are the same or different and are an aliphatic organic group or an aromatic organic group.) (In the formula, R4 and R5 are a hydrogen atom, an aliphatic organic group, or an aromatic organic group).
    Type: Grant
    Filed: April 20, 2015
    Date of Patent: August 14, 2018
    Assignees: Kaneka Corporation, Japan Aerospace Exploration Agency
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Patent number: 10017666
    Abstract: An imide resin composition including a terminal-modified imide oligomer of General Formula (1) and a thermoplastic aromatic polyimide of General Formula (2). (In Formula (1), either R1 or R2 shows a phenyl group and the other shows a hydrogen atom; R3 and R4 show a divalent residue of aromatic diamine; R5 and R6 show a tetravalent residue of aromatic tetracarboxylic acid; m and n satisfy relationships of m?1, n?0, 1?m+n?20, and 0.05?m/(m+n)?1; and an arrangement of repeating units may be either a block or random.) (In Formula (2), R1 and R2 show a divalent residue of aromatic diamine; R3 shows a tetravalent residue of aromatic tetracarboxylic acid; m and n satisfy relationships of m?1 and n?0, and an arrangement of repeating units may be either a block or random).
    Type: Grant
    Filed: April 21, 2014
    Date of Patent: July 10, 2018
    Assignees: Kaneka Corporation, Japan Aerospace Exploration Agency
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Publication number: 20170152399
    Abstract: Provided is a varnish including 1 to 500 parts by weight of an aromatic tetracarboxylic acid diester (A) represented by General Formula (1), 1 to 450 parts by weight of 2-phenyl-4,4?-diaminodiphenyl ether (B), 1 to 100 parts by weight of a 4-(2-phenylethynyl)phthalic acid monoester (C) represented by General Formula (2), and 100 parts by weight of an organic solvent having a boiling point of 150° C. or less at 1 atmosphere or a mixture of two or more of the organic solvents (D). The components (A), (B), and (C) are dissolved in the varnish. (In the formula, R1 is an aromatic tetracarboxylic acid diester residue; R2 and R3 are the same or different and are an aliphatic organic group or an aromatic organic group.) (In the formula, R4 and R5 are a hydrogen atom, an aliphatic organic group, or an aromatic organic group.
    Type: Application
    Filed: April 20, 2015
    Publication date: June 1, 2017
    Applicants: Kaneka Corporation, Japan Aerospace Exploration Agency
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Publication number: 20160083618
    Abstract: An imide resin composition including a terminal-modified imide oligomer of General Formula (1) and a thermoplastic aromatic polyimide of General Formula (2). (In Formula (1), either R1 or R2 shows a phenyl group and the other shows a hydrogen atom; R3 and R4 show a divalent residue of aromatic diamine; R5 and R6 show a tetravalent residue of aromatic tetracarboxylic acid; m and n satisfy relationships of m?1, n?0, 1?m+n?20, and 0.05?m/(m+n)?1; and an arrangement of repeating units may be either a block or random.) (In Formula (2), R1 and R2 show a divalent residue of aromatic diamine; R3 shows a tetravalent residue of aromatic tetracarboxylic acid; m and n satisfy relationships of m?1 and n?0, and an arrangement of repeating units may be either a block or random.
    Type: Application
    Filed: April 21, 2014
    Publication date: March 24, 2016
    Applicants: Kaneka Corporation, Japan Aerospace Exploration Agency
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Patent number: 9051430
    Abstract: A novel resin-transfer-moldable terminal-modified imide oligomer having a residue of a tetravalent aromatic tetracarboxylic acid and represented by general formula (1), and the imide oligomer contains an oligomer where n is 0 in an amount of 10% by mole or more. In the formula, R1 and R2 are a hydrogen atom or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and one of R1 and R2 is the aromatic hydrocarbon group having 6 to 10 carbon atoms; R3 is an aromatic organic group surrounded by four carbonyl groups in the aromatic tetracarboxylic acid, and for a formula where n is 2 or more, Ras are optionally the same as or different from each other; and n is an integer of 0 or more and 6 or less.
    Type: Grant
    Filed: March 15, 2012
    Date of Patent: June 9, 2015
    Assignees: KANEKA CORPORATION, JAPAN AEROSPACE EXPLORATION AGENCY
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Patent number: 8846552
    Abstract: A novel terminally modified imide oligomer having excellent solubility in organic solvents, excellent solution storage stability, and excellent molding properties such as low melt viscosity. Also, a varnish obtained by dissolving the terminally modified imide oligomer in an organic solvent; a cure product obtained by using the terminally modified imide oligomer and having excellent thermal and mechanical characteristics such as heat resistance, elastic modulus, tensile strength at break and tensile elongation at break; a prepreg; and a fiber-reinforced laminate. The soluble terminally modified imide oligomer is represented by general formula (1). In the formula, R1 and R2 each represents a divalent aromatic diamine residue; R3 and R4 each represents a tetravalent aromatic tetracarboxylic acid residue; R5 and R6 each represents a hydrogen atom or a phenyl group, with R5 or R6 being a phenyl group; m and n satisfy the following relations: m?1, n?0, 1?m+n?20 and 0.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: September 30, 2014
    Assignees: Kaneka Corporation, Japan Aerospace Exporation Agency
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Publication number: 20140011950
    Abstract: A novel resin-transfer-moldable terminal-modified imide oligomer having a residue of a tetravalent aromatic tetracarboxylic acid and represented by general formula (1), and the imide oligomer contains an oligomer where n is 0 in an amount of 10% by mole or more. In the formula, R1 and R2 are a hydrogen atom or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and one of R1 and R2 is the aromatic hydrocarbon group having 6 to 10 carbon atoms; R3 is an aromatic organic group surrounded by four carbonyl groups in the aromatic tetracarboxylic acid, and for a formula where n is 2 or more, R3s are optionally the same as or different from each other; and n is an integer of 0 or more and 6 or less.
    Type: Application
    Filed: March 15, 2012
    Publication date: January 9, 2014
    Applicants: JAPAN AEROSPACE EXPLORATION AGENCY, KANEKA CORPORATION
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Publication number: 20110165809
    Abstract: A novel terminally modified imide oligomer having excellent solubility in organic solvents, excellent solution storage stability, and excellent molding properties such as low melt viscosity. Also, a varnish obtained by dissolving the terminally modified imide oligomer in an organic solvent; a cure product obtained by using the terminally modified imide oligomer and having excellent thermal and mechanical characteristics such as heat resistance, elastic modulus, tensile strength at break and tensile elongation at break; a prepreg; and a fiber-reinforced laminate. The soluble terminally modified imide oligomer is represented by general formula (1). In the formula, R1 and R2 each represents a divalent aromatic diamine residue; R3 and R4 each represents a tetravalent aromatic tetracarboxylic acid residue; R5 and R6 each represents a hydrogen atom or a phenyl group, with R5 or R6 being a phenyl group; m and n satisfy the following relations: m?1, n?0, 1?m+n?20 and 0.
    Type: Application
    Filed: September 3, 2009
    Publication date: July 7, 2011
    Applicants: KANEKA CORPORATION, JAPAN AEROSPACE EXPLORATION AGENCY
    Inventors: Masahiko Miyauchi, Yuichi Ishida, Toshio Ogasawara, Rikio Yokota
  • Patent number: 7019103
    Abstract: A terminal-crosslinkable polyamic acid oligomer having 1) heat resistance indicated by Tg of 300° C. or more and a pyrolysis temperature of 500° C. or more, 2) toughness, and 3) capability of allowing an increase in concentration. The polyamic acid oligomer is obtained by reacting an aromatic tetracarboxylic dianhydride including 2,2?,3,3?-biphenyltetracarboxylic dianhydride, an aromatic diamine compound, and a reactive crosslinking agent including an amino group or acid anhydride group and a crosslinkable group in the molecule, and includes a crosslinkable group at the molecular terminal.
    Type: Grant
    Filed: May 5, 2004
    Date of Patent: March 28, 2006
    Assignees: JSR Corporation, Ube Industries, Ltd.
    Inventors: Rikio Yokota, Kohei Goto, Hideki Ozawa
  • Publication number: 20050014925
    Abstract: A terminal-crosslinkable polyamic acid oligomer having 1) heat resistance indicated by Tg of 300° C. or more and a pyrolysis temperature of 500° C. or more, 2) toughness, and 3) capability of allowing an increase in concentration. The polyamic acid oligomer is obtained by reacting an aromatic tetracarboxylic dianhydride including 2,2?,3,3?-biphenyltetracarboxylic dianhydride, an aromatic diamine compound, and a reactive crosslinking agent including an amino group or acid anhydride group and a crosslinkable group in the molecule, and includes a crosslinkable group at the molecular terminal.
    Type: Application
    Filed: May 5, 2004
    Publication date: January 20, 2005
    Applicants: JSR CORPORATION, UBE INDUSTRIES, LTD.
    Inventors: Rikio Yokota, Kohei Goto, Hideki Ozawa
  • Patent number: 6281323
    Abstract: Terminal-modified imide oligomers with an inherent viscosity of 0.05-1 obtained by reacting 2,3,3′,4′-biphenyltetracarboxylic dianhydride, an aromatic diamine compound and 4-(2-phenylethynyl)phthalic anhydride, and their cured products. There are provided highly practical terminal-modified imide oligomers and their cured products, which cured products have satisfactory heat resistance and mechanical properties.
    Type: Grant
    Filed: November 19, 1999
    Date of Patent: August 28, 2001
    Assignee: Ube Industries, Ltd.
    Inventors: Rikio Yokota, Masatoshi Hasegawa, Hiroaki Yamaguchi