Patents by Inventor Kouki Wakabayashi
Kouki Wakabayashi 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).
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Patent number: 11959197Abstract: A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.Type: GrantFiled: August 15, 2019Date of Patent: April 16, 2024Assignee: Mitsubishi Chemical CorporationInventors: Naomasa Matsuyama, Yuutarou Nakamura, Norifumi Hirota, Hiroko Matsumura, Katsuhiko Ikeda, Kouki Wakabayashi, Tadashi Ootani, Akihiro Itou, Kenji Hirano, Akito Hatayama, Kenji Kaneta, Atsushi Nakajima
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Patent number: 11787913Abstract: A sizing agent for carbon fiber includes component (A), component (B), and component (C), in which the component (A) is at least one selected from the group consisting of component (A-1), component (A-2), and component (A-3); the component (A-1) is a urethane compound having a structure of Formula (1-1) in the molecule, the component (A-2) is an ester compound having a structure represented by Formula (1-2) in the molecule, the component (A-3) is an amide compound having a structure of Formula (1-3) in the molecule; the component (B) is an epoxy compound selected from the group consisting of an epoxy compound represented by Formula (2), an epoxy compound represented by Formula (3), and an epoxy compound represented by Formula (4); and the component (C) is a bisphenol type epoxy compound.Type: GrantFiled: April 23, 2019Date of Patent: October 17, 2023Assignee: Mitsubishi Chemical CorporationInventors: Kenji Kaneta, Takaaki Suzuki, Kouki Wakabayashi, Akihiro Ito, Naoki Sugiura
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Publication number: 20210309820Abstract: Use of a sizing agent having a heat weight loss B-1 of 65% or more as determined by a specific measurement method, or a sizing agent containing a surfactant and a compound represented by formula (1):Type: ApplicationFiled: June 22, 2021Publication date: October 7, 2021Applicant: Mitsubishi Chemical CorporationInventors: Kenji KANETA, Naoki SUGIURA, Kouki WAKABAYASHI
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Publication number: 20210108363Abstract: A sizing agent is provided, the sizing agent being blended with a component (A) and a component (B), wherein a mass ratio A/B of the component (A) to the component (B) is 0.5 to 20, and a proportion of a total mass of the component (A) and the component (B) with respect to a total mass of the sizing agent is 80% by mass or more, wherein the component (A) is an epoxy resin having a viscosity of 1 to 180,000 Pa·s at 30° C., and the component (B) is an aliphatic ester compound having a freezing point of 50° C. or lower.Type: ApplicationFiled: December 22, 2020Publication date: April 15, 2021Applicant: Mitsubishi Chemical CorporationInventors: Kenji KANETA, Kouki WAKABAYASHI, Tsuyoshi TAKADA, Hiroyuki NAKAO
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Publication number: 20200002850Abstract: A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.Type: ApplicationFiled: August 15, 2019Publication date: January 2, 2020Applicant: Mitsubishi Chemical CorporationInventors: Naomasa Matsuyama, Yuutarou Nakamura, Norifumi Hirota, Hiroko Matsumura, Katsuhiko Ikeda, Kouki Wakabayashi, Tadashi Ootani, Akihiro Itou, Kenji Hirano, Akito Hatayama, Kenji Kaneta, Atsushi Nakajima
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Publication number: 20190249358Abstract: A sizing agent for carbon fiber includes component (A), component (B), and component (C), in which the component (A) is at least one selected from the group consisting of component (A-1), component (A-2), and component (A-3); the component (A-1) is a urethane compound having a structure of Formula (1-1) in the molecule, the component (A-2) is an ester compound having a structure represented by Formula (1-2) in the molecule, the component (A-3) is an amide compound having a structure of Formula (1-3) in the molecule; the component (B) is an epoxy compound selected from the group consisting of an epoxy compound represented by Formula (2), an epoxy compound represented by Formula (3), and an epoxy compound represented by Formula (4); and the component (C) is a bisphenol type epoxy compound.Type: ApplicationFiled: April 23, 2019Publication date: August 15, 2019Applicant: Mitsubishi Chemical CorporationInventors: Kenji KANETA, Takaaki SUZUKI, Kouki WAKABAYASHI, Akihiro ITO, Naoki SUGIURA
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Publication number: 20190233975Abstract: Provided is a carbon fiber bundle for obtaining a fiber-reinforced plastic having high mechanical characteristics. An acrylonitrile swollen fiber for a carbon fiber having openings of 10 nm or more in width in the circumference direction of the swollen fiber at a ratio in the range of 0.3 openings/?m2 or more and 2 openings/?m2 or less on the surface of the swollen fiber, and the swollen fiber is not treated with a finishing oil agent. A precursor fiber obtained by treating the swollen fiber with a silicone-based finishing oil agent has a silicon content of 1700 ppm or more and 5000 ppm or less, and the silicon content is 50 ppm or more and 300 ppm or less after the finishing oil agent is washed away with methyl ethyl ketone by using a Soxhlet extraction apparatus for 8 hours. The fiber is preferably an acrylonitrile copolymer containing acrylonitrile in an amount of 96.0 mass % or more and 99.7 mass % or less and an unsaturated hydrocarbon having at least one carboxyl group or ester group in an amount of 0.Type: ApplicationFiled: April 4, 2019Publication date: August 1, 2019Applicant: MITSUBISHI CHEMICAL CORPORATIONInventors: Hiroshi HASHIMOTO, Naoki SUGIURA, Yasuyuki FUJII, Hiroko MATSUMURA, Takahiro OKUYA, lsao OOKI, Masahiro HATA, Kouki WAKABAYASHI, Akiyoshi KOGAME, Kazunori SUMIYA, Akito HATAYAMA
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Publication number: 20190040549Abstract: Provided is a carbon fiber bundle for obtaining a fiber-reinforced resin having high mechanical characteristics. A carbon fiber bundle formed of single carbon fibers, each of which has no uneven surface structure of 0.6 ?m or more in length extending in the longitudinal direction of the single fiber; which has an uneven structure having a difference in height (Rp?v) of 5 to 25 nm between the highest portion and the lowest portion of the surface of the single fiber and having an average roughness Ra of 2 to 6 nm; and which has a ratio of the major axis to the minor axis (major axis/minor axis) of a cross-section of the single fiber of 1.00 to 1.01, wherein a mass of the single fiber per unit length falls within the range of 0.030 to 0.042 mg/m; a strand strength is 5900 MPa or more; a strand elastic modulus measured by the ASTM method is 250 to 380 GPa; and a knot tenacity is 900 N/mm2 or more.Type: ApplicationFiled: October 12, 2018Publication date: February 7, 2019Applicant: Mitsubishi Chemical CorporationInventors: Naoki SUGIURA, Takahiro OKUYA, Hiroshi HASHIMOTO, Isao OOKI, Hiroko MATSUMURA, Masahiro HATA, Kouki WAKABAYASHI, Akito HATAYAMA
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Patent number: 9862824Abstract: The present invention provides: a carbon fiber sizing agent that can obtain a carbon fiber bundle having a superior effect of improving mechanical properties when composited using a resin; an aqueous dispersion thereof; a carbon fiber bundle; a sheet-shaped article having a carbon fiber bundle; and a composite material. The carbon fiber sizing agent contains: a compound (A) that is an ester of an unsaturated monobasic acid and an epoxy compound having a plurality of epoxy groups in the molecule, and that has at least one epoxy group in the molecule; a urethane acrylate oligomer (B) that is bifunctional and that has a tensile elongation rate of the cured product of at least 40%; and a polyurethane resin (C) having a tensile elongation rate of a dried coating film of 350-900% inclusive. The amounts of A-C contained satisfy the conditions described in the description. The aqueous dispersion disperses the sizing agent. The carbon fiber bundle contains 0.6-3.0 mass % inclusive of the sizing agent.Type: GrantFiled: August 21, 2012Date of Patent: January 9, 2018Assignee: Mitsubishi Chemical CorporationInventors: Kouki Wakabayashi, Naoki Sugiura, Masahiro Hata, Shigekazu Takeda, Keigo Yoshida, Shuuichi Nakamura
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Publication number: 20140256855Abstract: The present invention provides: a carbon fiber sizing agent that can obtain a carbon fiber bundle having a superior effect of improving mechanical properties when composited using a resin; an aqueous dispersion thereof; a carbon fiber bundle; a sheet-shaped article having a carbon fiber bundle; and a composite material. The carbon fiber sizing agent contains: a compound (A) that is an ester of an unsaturated monobasic acid and an epoxy compound having a plurality of epoxy groups in the molecule, and that has at least one epoxy group in the molecule; a urethane acrylate oligomer (B) that is bifunctional and that has a tensile elongation rate of the cured product of at least 40%; and a polyurethane resin (C) having a tensile elongation rate of a dried coating film of 350-900% inclusive. The amounts of A-C contained satisfy the conditions described in the description. The aqueous dispersion disperses the sizing agent. The carbon fiber bundle contains 0.6-3.0 mass % inclusive of the sizing agent.Type: ApplicationFiled: August 21, 2012Publication date: September 11, 2014Applicant: MITSUBISHI RAYON CO., LTD.Inventors: Kouki Wakabayashi, Naoki Sugiura, Masahiro Hata, Shigekazu Takeda, Keigo Yoshida, Shuuichi Nakamura
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Patent number: 8679991Abstract: The invention relates to a prepreg containing a reinforcing fiber, a sheet-like reinforcing fiber substrate including the reinforcing fiber, and a matrix resin, wherein the matrix resin is impregnated into the sheet-like reinforcing fiber substrate and also covers one surface of the sheet-like reinforcing fiber substrate, such that the matrix resin impregnation ratio is within a range of 35% to 95%. The invention also relates to a prepreg containing a reinforcing fiber substrate in the form of a sheet and formed from a reinforcing fiber woven fabric, and a matrix resin, wherein at least one surface of the reinforcing fiber substrate displays a sea-and-island-type pattern with resin-impregnated portions (island portions) and fiber portions (sea portions), such that a surface coverage of the matrix resin is within a range of 3% to 80%.Type: GrantFiled: April 13, 2012Date of Patent: March 25, 2014Assignee: Mitsubishi Rayon Co., Ltd.Inventors: Kazuya Goto, Kazuki Koga, Tadayoshi Saitou, Akihiro Ito, Tsuneo Takano, Kouki Wakabayashi
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Publication number: 20140057514Abstract: This invention relates to a prepreg containing a reinforcing fiber, a reinforcing fiber substrate in the form of a sheet and containing the reinforcing fiber, and a matrix resin, such that the matrix resin is impregnated into the reinforcing fiber substrate and also covers one surface of the reinforcing fiber substrate, and an impregnation ratio of the matrix resin is within a range of 35% to 95%.Type: ApplicationFiled: November 5, 2013Publication date: February 27, 2014Applicant: MITSUBISHI RAYON CO., LTD.Inventors: Kazuya Goto, Kazuki Koga, Tadayoshi Saitou, Akihiro Ito, Tsuneo Takano, Kouki Wakabayashi
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Publication number: 20120276795Abstract: The invention relates to a prepreg containing a reinforcing fiber, a sheet-like reinforcing fiber substrate including the reinforcing fiber, and a matrix resin, wherein the matrix resin is impregnated into the sheet-like reinforcing fiber substrate and also covers one surface of the sheet-like reinforcing fiber substrate, such that the matrix resin impregnation ratio is within a range of 35% to 95%. The invention also relates to a prepreg containing a reinforcing fiber substrate in the form of a sheet and formed from a reinforcing fiber woven fabric, and a matrix resin, wherein at least one surface of the reinforcing fiber substrate displays a sea-and-island-type pattern with resin-impregnated portions (island portions) and fiber portions (sea portions), such that a surface coverage of the matrix resin is within a range of 3% to 80%.Type: ApplicationFiled: April 13, 2012Publication date: November 1, 2012Inventors: Kazuya GOTO, Kazuki KOGA, Tadayoshi SAITOU, Akihiro ITO, Tsuneo TAKANO, Kouki WAKABAYASHI
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Publication number: 20120088104Abstract: Provided is a carbon fiber bundle for obtaining a fiber-reinforced plastic having high mechanical characteristics. An acrylonitrile swollen fiber for a carbon fiber having openings of 10 nm or more in width in the circumference direction of the swollen fiber at a ratio in the range of 0.3 openings/?m2 or more and 2 openings/?m2 or less on the surface of the swollen fiber, and the swollen fiber is not treated with a finishing oil agent. A precursor fiber obtained by treating the swollen fiber with a silicone-based finishing oil agent has a silicon content of 1700 ppm or more and 5000 ppm or less, and the silicon content is 50 ppm or more and 300 ppm or less after the finishing oil agent is washed away with methyl ethyl ketone by using a Soxhlet extraction apparatus for 8 hours. The fiber is preferably an acrylonitrile copolymer containing acrylonitrile in an amount of 96.0 mass % or more and 99.7 mass % or less and an unsaturated hydrocarbon having at least one carboxyl group or ester group in an amount of 0.Type: ApplicationFiled: June 10, 2010Publication date: April 12, 2012Applicant: MITSUBISHI RAYON CO., LTD.Inventors: Hiroshi Hashimoto, Naoki Sugiura, Yasuyuki Fujii, Hiroko Matsumura, Takahiro Okuya, Isao Ooki, Masahiro Hata, Kouki Wakabayashi, Akiyoshi Kogame, Kazunori Sumiya, Akito Hatayama
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Publication number: 20120088103Abstract: Provided is a carbon fiber bundle for obtaining a fiber-reinforced resin having high mechanical characteristics. A carbon fiber bundle formed of single carbon fibers, each of which has no uneven surface structure of 0.6 ?m or more in length extending in the longitudinal direction of the single fiber; which has an uneven structure having a difference in height (Rp?v) of 5 to 25 nm between the highest portion and the lowest portion of the surface of the single fiber and having an average roughness Ra of 2 to 6 nm; and which has a ratio of the major axis to the minor axis (major axis/minor axis) of a cross-section of the single fiber of 1.00 to 1.01, wherein a mass of the single fiber per unit length falls within the range of 0.030 to 0.042 mg/m; a strand strength is 5900 MPa or more; a strand elastic modulus measured by the ASTM method is 250 to 380 GPa; and a knot tenacity is 900 N/mm2 or more.Type: ApplicationFiled: June 10, 2010Publication date: April 12, 2012Applicant: MITSUBISHI RAYON CO., LTDInventors: Naoki Sugiura, Takahiro Okuya, Hiroshi Hashimoto, Isao Ooki, Hiroko Matsumura, Masahiro Hata, Kouki Wakabayashi, Akito Hatayama
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Publication number: 20110151206Abstract: An FRP is produced using a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin is impregnated into the sheet-like reinforcing fiber substrate and also covers one surface of the sheet-like reinforcing fiber substrate, and the matrix resin impregnation ratio is within a range of 35% to 95%; a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin exists on both surfaces of the sheet-like reinforcing fiber substrate, and the portion inside the sheet-like reinforcing fiber substrate into which the matrix resin has not been impregnated is continuous; or a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein at least one surface exhibits a sea-and-island-type pattern comprising resin-impregnated portions (island portions) where the matType: ApplicationFiled: March 1, 2011Publication date: June 23, 2011Inventors: Kazuya Goto, Kazuki Koga, Tadayoshi Saitou, Akihiro Ito, Tsuneo Takano, Kouki Wakabayashi
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Publication number: 20090123717Abstract: An FRP is produced using a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin is impregnated into the sheet-like reinforcing fiber substrate and also covers one surface of the sheet-like reinforcing fiber substrate, and the matrix resin impregnation ratio is within a range of 35% to 95%; a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin exists on both surfaces of the sheet-like reinforcing fiber substrate, and the portion inside the sheet-like reinforcing fiber substrate into which the matrix resin has not been impregnated is continuous; or a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein at least one surface exhibits a sea-and-island-type pattern comprising resin-impregnated portions (island portions) where the matType: ApplicationFiled: October 2, 2008Publication date: May 14, 2009Applicant: Mitsubishi Rayon co., Ltd.Inventors: Kazuya Goto, Kazuki Koga, Tadayoshi Saitou, Akihiro Ito, Tsuneo Takano, Kouki Wakabayashi
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Publication number: 20060035548Abstract: An FRP is produced using a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin is impregnated into the sheet-like reinforcing fiber substrate and also covers one surface of the sheet-like reinforcing fiber substrate, and the matrix resin impregnation ratio is within a range of 35% to 95%; a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin exists on both surfaces of the sheet-like reinforcing fiber substrate, and the portion inside the sheet-like reinforcing fiber substrate into which the matrix resin has not been impregnated is continuous; or a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein at least one surface exhibits a sea-and-island-type pattern comprising resin-impregnated portions (island portions) where the matType: ApplicationFiled: July 18, 2003Publication date: February 16, 2006Applicant: Mitsubishi Rayon Co., Ltd.Inventors: Kazuya Goto, Kazuki Koga, Tadayoshi Saitou, Akihiro Ito, Tsuneo Takano, Kouki Wakabayashi