Patents Assigned to Kureha Corporation
  • Patent number: 11078179
    Abstract: In a method for producing a cyclic ester according to an embodiment of the present invention, a mixture (I) containing an aliphatic polyester, a specific polyalkylene glycol diether, and a sulfonic acid compound as a thermal stabilizer is prepared and heated in predetermined conditions to obtain a mixture (II) in a state of solution. Furthermore, heating of the mixture (II) is continued to distill, together with the polyalkylene glycol diether, a cyclic ester formed by the depolymerization reaction, and thus a distillate (III) is obtained. The cyclic ester is recovered from the distillate (III). At this time, a specific solubilizing agent is added to at least one of the mixture (I) or (II). In this production method, the sulfonic acid compound as the thermal stabilizer is contained in the mixtures (I) and (II) and the distillate (III).
    Type: Grant
    Filed: March 7, 2019
    Date of Patent: August 3, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Nanako Saigusa, Takenori Tose, Toshihiko Ono, Yoshinori Suzuki
  • Publication number: 20210229405
    Abstract: Provided is a heat-shrinkable multilayer film having high strength and excellent followability to its contents. The heat-shrinkable multilayer film according to the present invention is composed of at least three layers of a surface layer (a) including a thermoplastic resin; an intermediate layer (b) including a polyamide-based resin; and a surface layer (c) including a sealable resin. (A) The load per unit width at 10% elongation is 0.70 N/mm or less in both a longitudinal direction (MD) and a transverse direction (TD) in a tensile test at 90° C. (B) The puncture strength per unit thickness is 0.200 N/?m or greater.
    Type: Application
    Filed: April 22, 2019
    Publication date: July 29, 2021
    Applicant: Kureha Corporation
    Inventors: Shota Nambu, Ichiro Kitada
  • Patent number: 11066895
    Abstract: A plug which does not cause an adverse effect such as failure of a member constituting the plug when a wellbore is plugged. A downhole plug (10) includes a mandrel (1) having a hollow structure, an annular sealing member (2) attached to an outer circumferential surface of the mandrel (1) and being deformable by exerted pressure, and an annular socket (3) attached, adjacent to the annular sealing member (2), onto the outer circumferential surface of the mandrel (1), downstream of where a pressure is exerted on the sealing member (2). The annular socket (3) is configured to include a socket-inner portion (31) which comes into contact with the outer circumferential surface of the mandrel (1), and a socket-outer portion (32) in an annular shape having an inner diameter equivalent to or larger than that of the socket-inner portion (31) and movably attached to the socket-inner portion (31). The socket-outer portion (32) includes a face facing the sealing member (2).
    Type: Grant
    Filed: July 23, 2018
    Date of Patent: July 20, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Seishiro Kobayashi, Teruaki Yoshii
  • Patent number: 11059952
    Abstract: A rubber composition for downhole tools having excellent degradability and storability is provided. The rubber composition for downhole tools includes degradable rubber, a degradation accelerator, and a degradation inhibitor. The degradation accelerator is at least one type of the compound represented by Formula (I) or Formula (II) below. The degradation inhibitor is at least one type selected from the group consisting of carbodiimide compounds, oxazoline compounds, oxazine compounds, and epoxy compounds. The content of the degradation accelerator is from 0.1 to 20 parts by mass relative to 100 parts by mass of the degradable rubber. The content of the degradation inhibitor is from 0.1 to 3 parts by mass relative to 100 parts by mass of the degradable rubber.
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: July 13, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Fuminori Kobayashi, Takuma Kobayashi, Hikaru Saijo
  • Patent number: 11046665
    Abstract: Provided is a method for producing a high purity ?-hydroxycarboxylic acid dimeric cyclic ester while heavy-component formation from an ?-hydroxycarboxylic acid oligomer is suppressed. An ?-hydroxycarboxylic acid dimeric cyclic ester is obtained by performing a depolymerization reaction in the coexistence of an inorganic acid or an inorganic acid salt or a mixture thereof; and an organophosphorus compound.
    Type: Grant
    Filed: December 18, 2017
    Date of Patent: June 29, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Haruyasu Yamaji, Yoshinori Suzuki, Toshihiko Ono
  • Publication number: 20210171726
    Abstract: There are provided a molded article of a composition containing a vinylidene fluoride-based polymer which, although having a thickness of greater than 50 ?m, has a low haze, and a novel method for producing the molded article. The molded article of vinylidene fluoride-based polymer of the present invention has a thickness greater than 50 ?m and a haze of 40% or less. In the production of a molded article, a composition of a vinylidene fluoride-based polymer having a predetermined shape is melted at a temperature within a range of the melting point of the polymer ±5° C. and molded.
    Type: Application
    Filed: August 29, 2018
    Publication date: June 10, 2021
    Applicant: Kureha Corporation
    Inventors: Tatsuaki MIYASHITA, Kazuyuki SUZUKI
  • Patent number: 11024852
    Abstract: A binder composition that exhibits sufficient adhesion and that achieves the excellent dispersibility of a conductive additive is provided. The binder composition according to an embodiment of the present invention is a binder composition including a vinylidene fluoride copolymer composition containing vinylidene fluoride and a monomer having an acidic functional group; and a ratio (Mn2/Mn1) of a number average molecular weight of the vinylidene fluoride copolymer composition after being adsorbed onto alumina (Mn2) to a number average molecular weight of the vinylidene fluoride copolymer composition before being adsorbed onto alumina (Mn1) being less than 1.
    Type: Grant
    Filed: May 18, 2017
    Date of Patent: June 1, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Yuki Sakai, Shintarou Kamata, Emi Sugawara
  • Patent number: 11008421
    Abstract: The present invention is to provide a spherical polyamide fine particle having smooth sliding properties and causing a low degree of environmental pollution. The polyamide fine particle according to the present invention includes: a polyamide including a repetition of a structural unit having at least one alkylene group and at least one amide bond, each of the at least one alkylene group having from 1 to 5 carbon atoms, wherein the polyamide fine particle has a sphericity of 80 or greater.
    Type: Grant
    Filed: May 2, 2017
    Date of Patent: May 18, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Kazuyuki Yamane, Daisuke Murano, Yingge Xiao
  • Patent number: 11001565
    Abstract: The object of the present invention is to provide a glycolide production method capable of further increasing the production rate of glycolide. The glycolide production method according to the present invention includes adding metal iron to an aqueous glycolic acid solution, subjecting glycolic acid contained in the aqueous glycolic acid solution to which the metal iron is added, to dehydrating polycondensation to obtain a glycolic acid oligomer, and heating and depolymerizing the glycolic acid oligomer to obtain glycolide.
    Type: Grant
    Filed: February 20, 2019
    Date of Patent: May 11, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Yuta Yamadoi, Yoshinori Suzuki, Takenori Tose, Haruyasu Yamaji, Toshihiko Ono
  • Patent number: 10988586
    Abstract: Provided is a vinylidene fluoride resin film that is produced using a film composition including at least a vinylidene fluoride resin and inorganic particles; and that includes a plurality of protrusions on at least one surface thereof. Among the plurality of protrusions, the number of protrusions greater than 0.10 ?m in height from a flat surface at which the protrusions are not present is from 7.0 to 50 per 0.10 mm2 of the vinylidene fluoride resin film.
    Type: Grant
    Filed: January 16, 2018
    Date of Patent: April 27, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Nobufumi Sato, Keiko Aita, Hisaaki Terashima, Kazuyuki Kanno, Yusuke Sato
  • Publication number: 20210108482
    Abstract: A plug excellent in pressure resistance is provided. A downhole plug (20) includes a mandrel (1), a center element (2), at least one lip (3), and a pressure transmission means. When the center element (2) is deformed by applying a pressure of 50 MPa to the downhole plug (20) in the axial direction, a ratio (b/a) of an axial length (b) of a part where the mandrel (1) and the center element (2) are in contact with each other, to a maximum axial length (a) of the center element (2) in a cross section along the axial direction is less than 0.5.
    Type: Application
    Filed: February 1, 2019
    Publication date: April 15, 2021
    Applicant: Kureha Corporation
    Inventor: Teruaki YOSHII
  • Patent number: 10967115
    Abstract: Provided are a toxin separator and the like which are capable of selectively separating toxin present in a biological fluid by binding to protein, from the toxin and the protein. The toxin separator of the present invention also includes activated carbon of which a pore volume of pores having a pore diameter from 1.4 to 35 nm as measured by a nitrogen adsorption method is 0.06 cm3/g or greater.
    Type: Grant
    Filed: January 10, 2019
    Date of Patent: April 6, 2021
    Assignee: Kureha Corporation
    Inventors: Makoto Imaji, Kaori Kikuchi, Yoshiharu Itoh
  • Publication number: 20210087162
    Abstract: The object of the present invention is to provide a glycolide production method capable of sufficiently increasing the production rate of glycolide. The glycolide production method according to the present invention includes: adding metal titanium to an aqueous glycolic acid solution; subjecting glycolic acid contained in the aqueous glycolic acid solution to which the metal titanium is added, to dehydrating polycondensation to obtain a glycolic acid oligomer; and heating and depolymerizing the glycolic acid oligomer to obtain glycolide.
    Type: Application
    Filed: March 6, 2019
    Publication date: March 25, 2021
    Applicant: Kureha Corporation
    Inventors: Haruyasu YAMAJI, Yuta YAMADOI, Yoshinori SUZUKI, Toshihiko ONO
  • Patent number: 10945434
    Abstract: It is provided a plant disease controlling agent having low toxicity to human and animals and excellent handling safety, and showing excellent controlling effects on various plant diseases and high antibiotic action to plant disease germs. A compound represented by the following the general formula (I), or an N-oxide or agrochemically acceptable salt thereof.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: March 16, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Ryo Harigae, Atsushi Ito, Taiji Miyake, Toru Yamazaki
  • Publication number: 20210062609
    Abstract: A downhole plug for well completion is provided, which rapidly degrades after hydraulic fracturing, so that the flow path is recovered in a short time. A downhole plug (10) is provided, which includes: a mandrel (1) made of a degradable material; and a plurality of peripheral members (2, 3, 4, 5, 6a, 6b, 8a, 8b) made of a degradable material and disposed on an outer peripheral surface of the mandrel (1), where at least one of the plurality of peripheral members (6a, 6b) includes: a hollow portion (64) through which a fluid flowing along an axial direction of the mandrel (1) can pass; or a groove in at least a portion of, a surface serving as an outer surface of the downhole plug (10), or a surface in contact with the mandrel (1).
    Type: Application
    Filed: December 26, 2018
    Publication date: March 4, 2021
    Applicant: Kureha Corporation
    Inventors: Shinya TAKAHASHI, Aki SHITSUKAWA
  • Patent number: 10938034
    Abstract: The present invention provides a binder composition which suppresses a swelling ratio in an electrolyte solution while having sufficient peel strength. The binder composition according to the present invention contains a copolymer including monomer units derived from vinylidene fluoride, a fluorine-containing alkyl vinyl compound, and a crosslinkable monomer; the content of the monomer unit derived from the fluorine-containing alkyl vinyl compound in the copolymer being not less than 2 mass % and less than 10 mass %; and the content of the monomer unit derived from the crosslinkable monomer being less than 5 mass %.
    Type: Grant
    Filed: November 14, 2016
    Date of Patent: March 2, 2021
    Assignee: KUREHA CORPORATION
    Inventors: Yoshiyuki Nagasawa, Tamito Igarashi
  • Patent number: 10927354
    Abstract: An enzyme has an activity of reversible dehydrogenation of D-amino acid and is a hexamer of polypeptides having an amino acid sequence that has 80% or more identity with the amino acid sequence of SEQ ID NO: 2. The amino acid sequence of the polypeptide can include one or more amino acid substitutions for one or more amino acid residues of SEQ ID NO: 2.
    Type: Grant
    Filed: August 9, 2018
    Date of Patent: February 23, 2021
    Assignees: KUREHA CORPORATION, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Hironaga Akita, Yuusuke Nakamichi, Masahiro Watanabe, Akinori Matsushika, Tomotake Morita
  • Publication number: 20210047448
    Abstract: As a novel vinylidene fluoride polymer and its use, provided are a binder composition, an electrode mixture, an electrode, and a non-aqueous electrolyte secondary battery including the vinylidene fluoride containing the vinylidene fluoride polymer. The vinylidene fluoride polymer includes a first structural unit derived from vinylidene fluoride and a second structural unit derived from a monomer other than vinylidene fluoride. The monomer to be the second structural unit is a primary amine, a secondary amine, or a tertiary amine having at least one of a hydroxyl group and a carboxyl group, and the content of the second structural unit is from 0.05 to 20 mol % when the total of structural units derived from all the monomers constituting the vinylidene fluoride polymer is 100 mol %.
    Type: Application
    Filed: October 29, 2018
    Publication date: February 18, 2021
    Applicant: KUREHA CORPORATION
    Inventors: Kenta AOKI, Shota KOBAYASHI, Kana ASHIDA
  • Publication number: 20210047468
    Abstract: Provided are non-spherical polyamide particles having small variations in particle shape. The polyamide particles include a polyamide including repeating structural units having at least one alkylene group and at least one amide bond, wherein each of the at least one alkylene group has 1 to 3 carbon atoms. The main shape of the particles is a non-spherical shape with a circularity of less than 0.98, and a coefficient of variation (CV) of the circularity distribution is 30% or less.
    Type: Application
    Filed: October 30, 2020
    Publication date: February 18, 2021
    Applicant: KUREHA CORPORATION
    Inventors: Daisuke MURANO, Kazuyuki YAMANE, Yingge XIAO, Yoshinori SUZUKI
  • Publication number: 20210047252
    Abstract: The present invention is to provide a method of producing an alkene that can further enhance the yield of an alkene, a reaction product, the method including bringing a gaseous halogenated alkane into contact with an alkaline aqueous solution in the presence of a phase-transfer catalyst. The objective above is achieved by a method of producing an alkene comprising bringing in the presence of a phase-transfer catalyst a liquid phase containing an alkaline aqueous solution and a water-insoluble solvent into contact with a gas phase containing a halogenated alkane that is soluble in the water-insoluble solvent.
    Type: Application
    Filed: October 18, 2018
    Publication date: February 18, 2021
    Applicant: Kureha Corporation
    Inventors: Kensuke SUZUKI, Hiraku TOHMIYA