Patents by Inventor Yoshitaka Takezawa

Yoshitaka Takezawa 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: 20200002464
    Abstract: An epoxy resin composition that comprises an epoxy resin and a curing agent, the epoxy resin comprising an epoxy compound that has, in one molecule, two or more structural units represented by the following Formula (I) and two or more epoxy groups, and the curing agent comprising a compound having two or more amino groups that are directly bound to an aromatic ring.
    Type: Application
    Filed: June 15, 2017
    Publication date: January 2, 2020
    Inventors: Yuka YOSHIDA, Kazumasa FUKUDA, Yoshitaka TAKEZAWA
  • Publication number: 20190375885
    Abstract: A production method for a glassy liquid-crystalline epoxy resin, comprising a process of cooling a liquid-crystalline epoxy resin to cause transition into a glassy state.
    Type: Application
    Filed: October 17, 2017
    Publication date: December 12, 2019
    Applicant: Hitachi Chemical Company, Ltd.
    Inventors: Shingo TANAKA, Tomoko HIGASHIUCHI, Naoki MARUYAMA, Kazumasa FUKUDA, Yoshitaka TAKEZAWA, Fusao HOJO
  • Publication number: 20190338068
    Abstract: An epoxy resin, comprising a first epoxy compound having a mesogenic structure and a second epoxy compound having two or more mesogenic structures that are the same as the mesogenic structure of the first epoxy compound, a proportion, determined by liquid chromatography, of the first epoxy compound being from 40% to 50% with respect to a total amount of the epoxy resin.
    Type: Application
    Filed: October 13, 2017
    Publication date: November 7, 2019
    Applicant: Hitachi Chemical Company, Ltd.
    Inventors: Naoki MARUYAMA, Tomoko HIGASHIUCHI, Kazumasa FUKUDA, Yuka YOSHIDA, Yoshitaka TAKEZAWA
  • Publication number: 20190338069
    Abstract: Provided is a resin composition for forming a resin layer of a laminate by coating, the resin composition having a thixotropic index at 25° C. of from 3 to 10, and the laminate includes a pair of members and the resin layer arranged between the pair of members.
    Type: Application
    Filed: May 23, 2017
    Publication date: November 7, 2019
    Inventors: Kazuya KIGUCHI, Tomoo NISHIYAMA, Yoshitaka TAKEZAWA
  • Publication number: 20190284332
    Abstract: An epoxy resin, comprising an epoxy compound having a mesogen structure, wherein, when performing a process of decreasing a temperature of the epoxy resin from 150° C. to 30° C. at a rate of 2° C./min, and a process of increasing the temperature of the epoxy resin from 30° C. to 150° C. at a rate of 2° C./min, in this order, the epoxy resin has a maximum value of ??2/??1 of 20 or less within a temperature range of from 30° C. to 150° C., wherein is a dynamic shear viscosity (Pa·s) measured in the process of decreasing the temperature, and ??1 is a dynamic shear viscosity (Pa·s) measured in the process of increasing the temperature, and ??2 being measured at the same temperature, and a value ??2 measured at 100° C. is 1000 Pa·s or less.
    Type: Application
    Filed: October 13, 2017
    Publication date: September 19, 2019
    Applicant: Hitachi Chemical Company, Ltd.
    Inventors: Naoki MARUYAMA, Tomoko HIGASHIUCHI, Kazumasa FUKUDA, Yuka YOSHIDA, Yoshitaka TAKEZAWA
  • Publication number: 20190256643
    Abstract: An epoxy resin obtained by a reaction of an epoxy resin monomer having a mesogen backbone and having two glycidyl groups in one molecule with a divalent phenol compound having, as substituents, two hydroxyl groups on one benzene ring, in which a number average molecular weight in gel permeation chromatographic measurement is from 600 to 2,500.
    Type: Application
    Filed: May 1, 2019
    Publication date: August 22, 2019
    Inventors: Hideyuki KATAGI, Kenji TANAKA, Yoshitaka TAKEZAWA, Haruaki SUE, Shinichi KOSUGI
  • Patent number: 10373727
    Abstract: A prepreg mica tape includes: a backing material (3); a boron nitride-containing layer (1) that is provided on or above one surface of the backing material (3) and that includes a boron nitride particle (5) and a first resin (4); and a mica-containing layer (2) that is provided on or above the surface of the backing material (3) on which the boron nitride-containing layer (1) is provided and that includes mica (6) and a second resin (4).
    Type: Grant
    Filed: October 9, 2014
    Date of Patent: August 6, 2019
    Assignee: HITACHI CHEMICAL COMPANY, LTD
    Inventors: Shihui Song, Takaya Yamamoto, Yoshitaka Takezawa
  • Publication number: 20190225794
    Abstract: A gas barrier material, comprising: a thermosetting resin capable of forming a smectic structure via a curing reaction; and an amine curing agent.
    Type: Application
    Filed: June 15, 2017
    Publication date: July 25, 2019
    Inventors: Kazumasa FUKUDA, Yoshitaka TAKEZAWA, Yuka YOSHIDA, Tetsushi MARUYAMA
  • Publication number: 20190115119
    Abstract: A coil for a rotating electrical machine, the coil comprising a coil conductor and an insulating layer that is disposed around an outer periphery of the coil conductor, the insulating layer comprising a mica tape, the mica tape comprising a mica layer including mica and a backing layer including a backing material, the mica comprising mica pieces having a particle size of 2.8 mm or more, as measured by a JIS standard sieve, at a proportion of less than 45% by mass of a total of the mica pieces that are obtained from the mica layer being separated from the backing layer.
    Type: Application
    Filed: April 10, 2017
    Publication date: April 18, 2019
    Inventors: Takaya Yamamoto, Miyuki Muromachi, Takao Takita, Keiji Fukushima, Yoshitaka Takezawa
  • Publication number: 20190055344
    Abstract: The present disclosure provides: an epoxy resin molding material including; an epoxy resin having a mesogen structure, a phenolic curing agent, an inorganic filler, and a curing accelerator having a quaternary phosphonium cation represented by the following Formula (I); a molded product and a molded cured product using the epoxy resin molding material; and a method for producing a molded cured product. In Formula (I), each of Ra to Rd independently represents an alkyl group having from 1 to 6 carbon atoms, or an aryl group, and the alkyl group and the aryl group may have a substituent.
    Type: Application
    Filed: August 25, 2016
    Publication date: February 21, 2019
    Applicant: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Kenji TANAKA, Yuka YOSHIDA, Shinichi KOSUGI, Shingo TANAKA, Hideyuki KATAGI, Haruaki SUE, Yoshitaka TAKEZAWA
  • Publication number: 20190040183
    Abstract: Provided is an epoxy resin composition including an epoxy resin and a curing agent, in which the epoxy resin contains a multimeric compound having at least one selected from the group consisting of a structural unit represented by the following Formula (IA) and a structural unit represented by the following Formula (IB), the multimeric compound contains a dimeric compound containing two structural units represented by the following Formula (II) in one molecule, and a ratio of the dimeric compound is from 15% by mass to 28% by mass with respect to the epoxy resin as a whole.
    Type: Application
    Filed: August 25, 2016
    Publication date: February 7, 2019
    Inventors: Yuka YOSHIDA, Kenji TANAKA, Hideyuki KATAGI, Yoshihiro AMANO, Shinichi KOSUGI, Haruaki SUE, Yoshitaka TAKEZAWA
  • Patent number: 10000679
    Abstract: Provided is a phenolic resin composition containing: an epoxy resin curing agent that contains a hydroxybenzene derivative represented by the following Formula (I) and a phenol resin having at least one partial structure selected from the group consisting of the following Formulae (IIa), (IIb), (IIc) and (IId); and an epoxy resin. In these Formulae, each of R1, R2, R3, R4 and R5 independently represents a hydroxy group, a hydrogen atom or an alkyl group; at least two of R1, R2, R3, R4 and R5 are hydroxy groups; each Ar independently represents at least one group selected from the group consisting of the following Formulae (IIIa) and (IIIb); each of R11 and R14 independently represents a hydrogen atom or a hydroxy group; and each of R12 and R13 independently represents a hydrogen atom or an alkyl group.
    Type: Grant
    Filed: June 20, 2013
    Date of Patent: June 19, 2018
    Assignee: Hitachi Chemical Company, Ltd.
    Inventors: Shinichi Kosugi, Haruaki Sue, Yoshitaka Takezawa, Hiroyuki Takahashi, Naoki Hara
  • Publication number: 20180163015
    Abstract: Provided are an epoxy resin composition including hexagonal boron nitride particles having an aspect ratio of 2 or more, a liquid crystalline epoxy monomer, and a curing agent, and the epoxy resin composition being capable of forming a resin matrix having a smectic domain by reacting the liquid crystalline epoxy monomer with the curing agent, and a thermally-conductive material precursor, a B-stage sheet, a prepreg, a heat dissipation material, a laminate, a metal substrate, and a printed circuit board, which use the epoxy resin composition.
    Type: Application
    Filed: May 20, 2016
    Publication date: June 14, 2018
    Inventors: Yoshitaka TAKEZAWA, Shingo TANAKA, Fusao HOJO
  • Publication number: 20180148622
    Abstract: A resin composition contains: a thermosetting resin; a thermally conductive filler; and mica; in which, when the thermally conductive filler is divided into a filler group (A) having a particle diameter of from 10 ?m to 100 ?m, a filler group (B) having a particle diameter of from 1.0 ?m to smaller than 10 ?m, and a filler group (C) having a particle diameter of from 0.1 ?m to smaller than 1.0 ?m, a ratio of the filler group (C) with regard to the thermally conductive filler, based on volume, is larger than a ratio of the filler group (B) with regard to the thermally conductive filler, based on volume.
    Type: Application
    Filed: May 24, 2016
    Publication date: May 31, 2018
    Inventors: Yoshitaka TAKEZAWA, Shihui SONG, Keiji FUKUSHIMA, Tomokazu TANASE, Tetsuji KATOH, Akihiro SANO, Hiroaki KOJIMA
  • Publication number: 20180137956
    Abstract: A coil for a rotary electrical machine comprising a coil conductor and an insulation layer disposed around an outer periphery of the coil conductor, the insulation layer comprising a cured product of a mica tape, the mica tape comprising mica, a reinforcing member and a thermosetting resin, and having a reaction heat generated by a curing reaction of the thermosetting resin, as measured by differential scanning calorimetry (DSC), of ?270 J/g or less.
    Type: Application
    Filed: July 15, 2016
    Publication date: May 17, 2018
    Applicant: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Takaya YAMAMOTO, Miyuki MUROMACHI, Takao TAKITA, Keiji FUKUSHIMA, Yoshitaka TAKEZAWA
  • Publication number: 20180044191
    Abstract: A method of producing a complex of a lamellar inorganic compound and an organic compound includes: heat-treating a particular non-swelling lamellar inorganic compound within a pyrolysis temperature range of the non-swelling lamellar inorganic compound; and intercalating an organic compound into the non-swelling lamellar inorganic compound in a dispersion liquid in which the heat-treated non-swelling lamellar inorganic compound is dispersed in a medium, thereby inserting the organic compound into an interlamellar space of the non-swelling lamellar inorganic compound.
    Type: Application
    Filed: March 3, 2016
    Publication date: February 15, 2018
    Applicants: HITACHI CHEMICAL COMPANY, LTD., NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Shihui SONG, Keiji FUKUSHIMA, Yoshitaka TAKEZAWA, Yuji HOTTA, Yusuke IMAI, Daisuke SHIMAMOTO, Yuichi TOMINAGA
  • Publication number: 20180009979
    Abstract: A resin composition constituted by containing an epoxy resin monomer having a mesogenic structure, a novolac resin containing a compound having a structural unit represented by the following general formula (I), and an inorganic filler is superior in preservation stability before curing, and can attain high thermal conductivity after curing. In the following general formula (I), R1, R2 and R3 independently represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group; m represents an integer of 0 to 2; and n an integer of 1 to 7.
    Type: Application
    Filed: September 20, 2017
    Publication date: January 11, 2018
    Inventors: Tomoo NISHIYAMA, Haruaki SUE, Hideyuki KATAGI, Naoki HARA, Hiroyuki TAKAHASHI, Yasuo MIYAZAKI, Yoshitaka TAKEZAWA, Hiroyuki TANAKA, Kensuke YOSHIHARA, Masayoshi JOUMEN
  • Publication number: 20170349695
    Abstract: An epoxy resin obtained by a reaction of an epoxy resin monomer having a mesogen backbone and having two glycidyl groups in one molecule with a divalent phenol compound having, as substituents, two hydroxyl groups on one benzene ring, in which a number average molecular weight in gel permeation chromatographic measurement is from 600 to 2,500.
    Type: Application
    Filed: December 25, 2015
    Publication date: December 7, 2017
    Inventors: Hideyuki KATAGI, Kenji TANAKA, Yoshitaka TAKEZAWA, Haruaki SUE, Shinichi KOSUGI
  • Publication number: 20160247595
    Abstract: A prepreg mica tape includes: a backing material (3); a boron nitride-containing layer (1) that is provided on or above one surface of the backing material (3) and that includes a boron nitride particle (5) and a first resin (4); and a mica-containing layer (2) that is provided on or above the surface of the backing material (3) on which the boron nitride-containing layer (1) is provided and that includes mica (6) and a second resin (4).
    Type: Application
    Filed: October 9, 2014
    Publication date: August 25, 2016
    Applicant: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Shihui SONG, Takaya YAMAMOTO, Yoshitaka TAKEZAWA
  • Patent number: 9249293
    Abstract: A composite particle is constituted to include: an aluminum nitride particle; a first coating layer that contains ?-alumina and coats at least a part of a region of a surface of the aluminum nitride particle; and a second coating layer that contains organic matter and coats a region other than the first coating layer of the surface of the aluminum nitride particle.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: February 2, 2016
    Assignee: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Yoshitaka Takezawa, Fusao Hojo, Shingo Tanaka, Hiroyuki Kagawa