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: 20200247943
    Abstract: An epoxy resin, comprising an epoxy compound having at least two mesogenic structures and at least one divalent biphenyl group.
    Type: Application
    Filed: September 29, 2017
    Publication date: August 6, 2020
    Applicant: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Yuka YOSHIDA, Naoki MARUYAMA, Tomoko HIGASHIUCHI, Kazumasa FUKUDA, Keiichiro NISHIMURA, Yoshitaka TAKEZAWA
  • Publication number: 20200223994
    Abstract: A resin sheet includes an epoxy resin including an epoxy resin oligomer and an epoxy resin monomer; a curing agent; and an inorganic filler, wherein a content of the inorganic filler is more than 30% by volume but less than 80% by volume.
    Type: Application
    Filed: August 25, 2016
    Publication date: July 16, 2020
    Inventors: Tomoo NISHIYAMA, Yoshitaka TAKEZAWA, Hideyuki KATAGI, Kazuya KIGUCHI
  • Publication number: 20200216324
    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 13, 2020
    Publication date: July 9, 2020
    Inventors: Shihui SONG, Keiji FUKUSHIMA, Yoshitaka TAKEZAWA, Yuji HOTTA, Yusuke IMAI, Daisuke SHIMAMOTO, Yuichi TOMINAGA
  • Publication number: 20200199287
    Abstract: An epoxy resin, comprising an epoxy compound, the epoxy compound comprising two or more structures represented by the following Formula (I) and at least one divalent biphenyl group: wherein, in Formula (I), each of R1 to R4 independently represents a hydrogen atom or an alkyl group having from 1 to 3 carbon atoms.
    Type: Application
    Filed: October 14, 2016
    Publication date: June 25, 2020
    Applicant: Hitachi Chemical Company, Ltd.
    Inventors: Tomoko HIGASHIUCHI, Naoki MARUYAMA, Yuka YOSHIDA, Kazumasa FUKUDA, Yoshitaka TAKEZAWA
  • Patent number: 10662279
    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: Grant
    Filed: August 25, 2016
    Date of Patent: May 26, 2020
    Assignee: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Yuka Yoshida, Kenji Tanaka, Hideyuki Katagi, Yoshihiro Amano, Shinichi Kosugi, Haruaki Sue, Yoshitaka Takezawa
  • Publication number: 20200163221
    Abstract: A circuit board production method, the method comprising a process of disposing a circuit sheet on a substrate, the circuit sheet comprising circuits and a resin portion disposed at spaces between the circuits.
    Type: Application
    Filed: April 10, 2017
    Publication date: May 21, 2020
    Inventors: Tomoo NISHIYAMA, Mitsuo TOGAWA, Yoshitaka TAKEZAWA, Yuki NAKAMURA, Kazuya KIGUCHI, Yasuo MIYAZAKI, Shinji AMANUMA
  • Publication number: 20200140651
    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: January 8, 2020
    Publication date: May 7, 2020
    Inventors: Yoshitaka TAKEZAWA, Shingo TANAKA, Fusao HOJO
  • Patent number: 10597485
    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: Grant
    Filed: October 17, 2017
    Date of Patent: March 24, 2020
    Assignee: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Shingo Tanaka, Tomoko Higashiuchi, Naoki Maruyama, Kazumasa Fukuda, Yoshitaka Takezawa, Fusao Hojo
  • Patent number: 10590232
    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: Grant
    Filed: May 23, 2017
    Date of Patent: March 17, 2020
    Assignee: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Kazuya Kiguchi, Tomoo Nishiyama, Yoshitaka Takezawa
  • Patent number: 10584228
    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: Grant
    Filed: May 20, 2016
    Date of Patent: March 10, 2020
    Assignee: HITACHI CHEMICAL COMPANY, LTD.
    Inventors: Yoshitaka Takezawa, Shingo Tanaka, Fusao Hojo
  • Publication number: 20200071455
    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: November 8, 2019
    Publication date: March 5, 2020
    Inventors: Kazuya KIGUCHI, Tomoo NISHIYAMA, Yoshitaka TAKEZAWA
  • 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: 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: 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: 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