Patents Assigned to Kureha Corporation
  • Patent number: 10731006
    Abstract: The production method of the present invention includes: a supplying step of supplying reaction raw materials to at least one of a plurality of reaction vessels mutually communicated through a gas phase; a polymerizing step of carrying out a polymerization reaction; and a step of removing at least some of the water present in the reaction vessels. Each of the steps is carried out in parallel, and a reaction mixture is transferred sequentially between the reaction vessels. The total amount of water contained in the reaction raw materials in at least one of the reaction vessels to which the reaction raw materials are supplied is 3 moles or more per mole of the sulfur source, and the internal temperature of at least one of the reaction vessels to which the reaction raw materials are supplied is from 180° C. to 300° C.
    Type: Grant
    Filed: February 5, 2018
    Date of Patent: August 4, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Kenji Suzuki, Michihisa Miyahara, Hiroshi Sakabe
  • Patent number: 10731005
    Abstract: The present invention provides a method for producing granular polyarylene sulfide (PAS) with increased average particle size and enhanced particle strength, a method for increasing the average particle size of granular PAS, a method for enhancing the particle strength of granular PAS, and granular PAS.
    Type: Grant
    Filed: March 24, 2017
    Date of Patent: August 4, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Akihiro Konno, Hiroyuki Sato
  • Publication number: 20200224178
    Abstract: An enzyme having the following characteristics of (a) and (b): (a) the enzyme has an activity of reversible dehydrogenation of D-amino acid; and (b) the enzyme is a hexamer of polypeptides having an amino acid sequence that has 80% or more identity with an amino acid sequence of SEQ ID NO: 2.
    Type: Application
    Filed: August 9, 2018
    Publication date: July 16, 2020
    Applicants: Kureha Corporation, National Institute Of Advanced Industrial Science And Technology
    Inventors: Hironaga AKITA, Yuusuke NAKAMICHI, Masahiro WATANABE, Akinori MATSUSHIKA, Tomotake MORITA
  • Patent number: 10703861
    Abstract: A method for producing polyarylene sulfide of the present invention includes the steps of: supplying reaction raw materials to at least one of a plurality of reaction vessels mutually communicated through a gas phase; carrying out a polymerization reaction; and removing at least some of the water present in the reaction vessels. Each of the steps is carried out in parallel, and a reaction mixture is transferred sequentially between the reaction vessels. At that time, the amount of heat that is removed in the polymerization reaction is less than the amount of reaction heat of the polymerization reaction.
    Type: Grant
    Filed: February 5, 2018
    Date of Patent: July 7, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Michihisa Miyahara, Kenji Suzuki, Hiroshi Sakabe
  • Publication number: 20200207949
    Abstract: Provided is a downhole tool member containing a polyglycolic acid resin composition that is easy to process during extrusion molding or injection molding, is able to reduce cracks during cutting and transportation, and has sufficient strength in a well in a high temperature environment. The downhole tool member according to an embodiment of the present invention contains a polyglycolic acid resin composition, in which a weight-average molecular weight Mw is from 150,000 to 300,000, and a melt viscosity My (Pa·s), measured at a temperature of 270° C. under a shearing speed of 122 sec?1, satisfies Mv<6.2×10?15×Mw3.2.
    Type: Application
    Filed: July 23, 2018
    Publication date: July 2, 2020
    Applicant: Kureha Corporation
    Inventors: Takuma KOBAYASHI, Fuminori KOBAYASHI, Hikaru SAIJO, Mizuki SAITO, Hiroaki YOSHIDA
  • Patent number: 10647817
    Abstract: The present invention is to provide a method that can produce polyarylene sulfide having a high viscosity at a high yield. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture and producing a prepolymer until a pH of a reaction system reaches a range of 10 to 11; and a second-stage polymerization step of continuing the polymerization reaction.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: May 12, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Akihiro Konno, Ken-Ichi Takaki, Haruki Mokudai, Hiroyuki Sato
  • Patent number: 10647818
    Abstract: A method of producing a polyarylene sulfide (PAS) includes a preparation step of preparing a charged mixture containing an organic amide solvent, a sulfur source, water, and a dihalo aromatic compound; a first-stage polymerization step of performing a polymerization reaction on the charged mixture at a temperature of from 170 to 280° C. to produce a prepolymer having a conversion ratio of the dihalo aromatic compound of 50% or greater; and a second-stage polymerization step of continuing the polymerization reaction in a phase-separated state at a temperature of from 245 to 290° C. in a reaction system containing the prepolymer, and includes adding a polyfunctional compound to the reaction system in the phase-separated state. A PAS having a melt viscosity (310° C., shear rate: 1216 sec?1) of from 0.1 to 8000 Pa·s is produced by the method.
    Type: Grant
    Filed: December 18, 2015
    Date of Patent: May 12, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Akihiro Konno, Ken-Ichi Takaki, Yui Yoshida, Hiroyuki Sato
  • Patent number: 10626694
    Abstract: A downhole tool member for hydrocarbon resource recovery, comprising a shaped body of a polyglycolic acid resin having a weight average molecular weight of at least 70,000, having an effective thickness which is ½ or more of a critical thickness of surface decomposition, and exhibiting a thickness reduction rate in water which is constant with respect to time. As a result, it has become possible to more accurately design the strength and time up to the collapse of the downhole tool member which forms the whole or a part of a downhole tool for developing or repairing downholes for recovery of hydrocarbon resources, such as oil and gas.
    Type: Grant
    Filed: June 18, 2018
    Date of Patent: April 21, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Masayuki Okura, Hikaru Saijo, Katsumi Yoshida, Hiroyuki Sato
  • Patent number: 10619084
    Abstract: A plug for well drilling includes a mandrel and at least one diametrically expandable annular rubber member and at least one slip disposed on an outer circumferential surface orthogonal to an axial direction of the mandrel; (i) the mandrel being formed from a degradable material; and (ii) the at least one diametrically expandable annular rubber member being formed from a degradable rubber material having a rate of decrease of not less than 5% in 50% strain compressive stress after immersion in water at a temperature of 150° C. for 24 hours relative to the compressive stress before immersion; and/or having a rate of loss of mass of from 5 to 100% after immersion in water at a temperature of 150° C. for 72 hours relative to the mass before immersion. A well drilling method includes a step of isolating a borehole using the plug for well drilling, part or all of the plug being degraded thereafter.
    Type: Grant
    Filed: December 22, 2014
    Date of Patent: April 14, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Masayuki Okura, Takeo Takahashi
  • Patent number: 10604630
    Abstract: Provided is a PAS production method and a PAS production apparatus wherein, in a gas-liquid system including a gas phase containing water, a dihalo aromatic compound, and hydrogen sulfide and a liquid phase containing a polar organic solvent and PAS, the dihalo aromatic compound and the hydrogen sulfide that can be volatilized at the time of dehydration from the gas phase can be recovered.
    Type: Grant
    Filed: January 11, 2018
    Date of Patent: March 31, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Michihisa Miyahara, Kenji Suzuki, Hiroshi Sakabe
  • Patent number: 10586988
    Abstract: In an electrode structural body, a coated film is obtained by applying an electrode mixture including an electrode active material, a first fluorine based polymer, and a solvent and drying the mixture, then formed on the surface of a current collector, the first fluorine based polymer has one or more side chains represented by the following Formula (1), and the coated film is subjected to heat treatment. —X—COOH??(1) (In Formula (1), X is an atomic group having a molecular weight of less than 500, the main chain of which is made up of 1 to 20 atoms).
    Type: Grant
    Filed: April 13, 2016
    Date of Patent: March 10, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Yuki Sakai, Emi Sugawara
  • Patent number: 10570255
    Abstract: Provided is a method of producing polyarylene sulfide at low cost while productivity enhancement and resource saving are attempted by avoiding the use of a complicated step and special apparatus (facility). The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide in an amount less than an equimolar amount relative to an amount of the sulfur source; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture, and producing a prepolymer having a dihalo aromatic compound conversion ratio of 50% or greater; and a second-stage polymerization step of adding an alkali metal hydroxide such that the alkali metal hydroxide is in an amount of 1.00 to 1.10 mol per 1 mol of the sulfur source, and continuing the polymerization reaction in a homogeneous liquid phase condition.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: February 25, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Haruki Mokudai, Akihiro Konno, Hiroyuki Sato
  • Publication number: 20200055290
    Abstract: Provided is a heat-shrinkable multilayer film including: an outer surface layer including a thermoplastic resin; an intermediate layer including a polyamide resin; and an inner surface layer including a sealable resin; the total thickness of the heat-shrinkable multilayer film being from 95 to 160 ?m; the thickness of the intermediate layer including the polyamide resin being from 17 to 47 ?m; the thickness of the inner surface layer being 55 ?m or greater; and the ratio of the thickness of the intermediate layer including the polyamide resin to the total thickness of the heat-shrinkable multilayer film being from 18 to 29%. The heat-shrinkable multilayer film of the present invention has high strength and excellent flexibility. Therefore, the heat-shrinkable multilayer film of the present invention is easily stretched and formed, and can be suitably used as a variety of packaging materials including a food packaging material.
    Type: Application
    Filed: October 18, 2017
    Publication date: February 20, 2020
    Applicant: KUREHA CORPORATION
    Inventors: Shota NAMBU, Ichiro KITADA, Tadayoshi ITOH
  • Patent number: 10556992
    Abstract: To provide a method of manufacturing polyarylene sulfide (PAS) while efficiently recovering an organic amide solvent at a low energy cost, without using an organic solvent, from washing wastewater produced by washing a raw material mixture containing PAS and an organic amide solvent using a solvent containing water; a method of manufacturing PAS by reducing the amount of water supplied when washing the raw material mixture using a solvent containing water; and PAS manufactured by these methods.
    Type: Grant
    Filed: December 28, 2018
    Date of Patent: February 11, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Michihisa Miyahara, Kenji Suzuki, Yuichi Katayose, Takayuki Kimura
  • Patent number: 10538629
    Abstract: Provided are a device for continuously producing poly(arylene sulfide) (hereinafter, referred to as PAS) and a method for continuous PAS production with which resource savings, energy savings, and a reduction in equipment cost are rendered possible. The device for continuous PAS production according to the present invention includes a housing chamber for housing a plurality of reaction cells; wherein the housing chamber is supplied with at least an organic amide solvent, a sulfur source, and a dihalo aromatic compound. In the reaction cells, the sulfur source is polymerized with the dihalo aromatic compound in the organic amide solvent to form a reaction mixture. The reaction cells communicate with each other through a gas phase within the housing chamber. The reaction cells are sequentially connected, and the reaction mixture sequentially moves to each reaction cell.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: January 21, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Michihisa Miyahara, Kenji Suzuki, Hiroshi Sakabe
  • Patent number: 10533072
    Abstract: The production method of the present invention includes: a supplying step of supplying reaction raw materials to at least one of a plurality of reaction vessels that mutually communicate through a gas phase; a polymerizing step of carrying out a polymerization reaction; and a step of removing at least some of the water present in the reaction vessels. Each of the steps is carried out in parallel, and a reaction mixture is transferred sequentially between the reaction vessels. The amount of water contained in the reaction mixture in at least one of the reaction vessels is from 0.1 moles to less than 3 moles per mole of a sulfur source, and the total amount of water contained in the reaction raw materials that are supplied is 3 moles or more per mole of the sulfur source.
    Type: Grant
    Filed: February 5, 2018
    Date of Patent: January 14, 2020
    Assignee: KUREHA CORPORATION
    Inventors: Kenji Suzuki, Michihisa Miyahara, Hiroshi Sakabe
  • Publication number: 20190382520
    Abstract: Provided is a rubber member for downhole tools, of which a decrease rate of 50% strain compressive stress after immersion for 24 hours in 150° C. water relative to 50% strain compressive stress before immersion is not less than 5%, and preferably not less than 50%. The rubber member is suitable for a seal member, ball sealer, ball seat, and a protecting member. Also provided is a downhole tool comprising the rubber member, and a method for recovering a hydrocarbon resource using the downhole tool.
    Type: Application
    Filed: July 18, 2019
    Publication date: December 19, 2019
    Applicant: Kureha Corporation
    Inventors: Takeo TAKAHASHI, Masayuki OKURA
  • Patent number: 10501582
    Abstract: The present invention is to provide a method of producing polyarylene sulfide that can produce polyarylene sulfide having a low halogen content simply and easily and at low cost. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of producing a prepolymer until a pH of a reaction system reaches a range of lower than 10 but 7 or higher by initiating a polymerization reaction by heating the mixture; and a second-stage polymerization step of continuing the polymerization reaction.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: December 10, 2019
    Assignee: KUREHA CORPORATION
    Inventors: Akihiro Konno, Ken-Ichi Takaki, Hiroyuki Sato
  • Publication number: 20190326602
    Abstract: To provide an electrode mixture that suppresses gelling of an electrode mixture slurry and maintains a high binding capacity between an electrode active material and a current collector even after an extended period of time has elapsed since an electrode mixture slurry was produced. The electrode mixture includes: a binder composition—containing a first copolymer of vinylidene fluoride and a polar group-containing compound; and a second copolymer of vinylidene fluoride and chlorotrifluoroethylene—; and an electrode active material of lithium oxide having a pH of water when extracted with water of not less than 10.5.
    Type: Application
    Filed: November 9, 2017
    Publication date: October 24, 2019
    Applicant: Kureha Corporation
    Inventors: Kenta AOKI, Shoko AOKI, Shota KOBAYASHI, Yasuhiro TADA
  • Patent number: 10424790
    Abstract: An object of the present invention is to provide a non-aqueous electrolyte secondary battery which has a large charge/discharge capacity, has a small irreversible capacity, and is capable of effectively using an active material. This object can be achieved by a material for a non-aqueous electrolyte secondary battery anode; a specific surface area determined by a BET method being not greater than 30 m2/g; an atomic ratio (H/C) of hydrogen atoms to carbon atoms determined by elemental analysis being not greater than 0.1; an average particle size being not greater than 50 ?m; and a diffraction intensity ratio (R-value) determined by Equation (1) being not greater than 1.
    Type: Grant
    Filed: August 10, 2015
    Date of Patent: September 24, 2019
    Assignee: KUREHA CORPORATION
    Inventors: Naohiro Sonobe, Kazuhiko Shimizu