Patents by Inventor Masahiro Gotoh

Masahiro Gotoh 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: 20220162089
    Abstract: A substituted ?-iron oxide magnetic particle powder having a reduced content of an ?-type iron-based oxide and Fe sites of ?-Fe2O3 partially substituted by another metal element is obtained by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites to a pH of between 2.0 and 7.0. Thereafter, a silicon compound having a hydrolyzable group is added to a dispersion liquid containing an iron oxyhydroxide having a substituent metal element or a mixture of an iron oxyhydroxide and a hydroxide of a substituent metal element. The dispersion liquid is neutralized to a pH of 8.0 or higher and the iron oxyhydroxide having a substituent metal element or the mixture of the iron oxyhydroxide and the hydroxide of a substituent metal element is coated with a chemical reaction product of the silicon compound. The dispersion is then heated.
    Type: Application
    Filed: March 13, 2020
    Publication date: May 26, 2022
    Inventors: Tatsuro HORI, Daisuke KODAMA, Shiho OBATA, Masahiro GOTOH
  • Publication number: 20220148775
    Abstract: There are provided a magnetoplumbite-type hexagonal crystal ferrite magnetic powder which can be suitably used as the material of a radio wave absorber having an excellent radio wave absorbing power in the 76 GHz band, and a method for producing the same. In a method for producing a magnetoplumbite-type hexagonal crystal ferrite magnetic powder, the method comprising the steps of: mixing powders of the raw materials of a magnetoplumbite-type hexagonal crystal ferrite magnetic powder, which is expressed by a compositional formula of AFe(12-x)AlxO19 (A is at least one selected from the group consisting of Sr, Ba, Ca and Pb, x=1.0 to 2.
    Type: Application
    Filed: January 30, 2020
    Publication date: May 12, 2022
    Applicant: Dowa Electronics Materials Co., Ltd.
    Inventors: Hidenori Yamaji, Masahiro Gotoh
  • Publication number: 20220089456
    Abstract: A substitution-type ?-iron oxide magnetic particle powder having a reduced content of a non-magnetic ?-type iron-based oxide and Fe sites of ?-Fe2O3 partially substituted by another metal element is obtained by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites to a pH of 2.0 or higher and 7.0 or lower. A silicon compound having a hydrolyzable group is added to a dispersion liquid containing an iron oxyhydroxide having a substituent metal element or a mixture of an iron oxyhydroxide and a hydroxide of a substituent metal element. The dispersion liquid is neutralized to a pH of 8.0 or higher and the iron oxyhydroxide having a substituent metal element or the mixture of the iron oxyhydroxide and the hydroxide of a substituent metal element is coated with a chemical reaction product of the silicon compound and then heated.
    Type: Application
    Filed: February 28, 2020
    Publication date: March 24, 2022
    Inventors: Tatsuro HORI, Daisuke KODAMA, Shiho OBATA, Masahiro GOTOH
  • Publication number: 20220081319
    Abstract: An iron-based oxide magnetic powder has good thermal stability and a small change in coercive force even in a high-temperature environment and is one composed of particles of ?-iron oxide in which Fe sites are partially substituted by another metal element. A production method for such an iron-based oxide magnetic powder includes allowing a phosphorus-containing ion to coexist when a precipitate of an iron hydroxide containing a substituent metal element produced by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites is coated with silicon oxide using a silane compound.
    Type: Application
    Filed: February 4, 2020
    Publication date: March 17, 2022
    Inventors: Shin-ichi OHKOSHI, Asuka NAMAI, Marie YOSHIKIYO, Daisuke KODAMA, Shiho OBATA, Masahiro GOTOH
  • Patent number: 11247265
    Abstract: An iron powder and method of making an iron powder. The method includes a step of neutralizing an acidic aqueous solution containing a trivalent iron ion and a phosphorus-containing ion, with an alkali aqueous solution, so as to provide a slurry of a precipitate of a hydrated oxide, or a step of adding a phosphorus-containing ion to a slurry containing a precipitate of a hydrated oxide obtained by neutralizing an acidic aqueous solution containing a trivalent iron ion with an alkali aqueous solution. A silane compound is added to the slurry so as to coat a hydrolysate of the silane compound on the precipitate of the hydrated oxide. The precipitate of the hydrated oxide after coating is recovered through solid-liquid separation, the recovered precipitate is heated to provide iron particles coated with a silicon oxide, and a part or the whole of the silicon oxide coating is dissolved and removed.
    Type: Grant
    Filed: July 10, 2017
    Date of Patent: February 15, 2022
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hidenori Yamaji, Masahiro Gotoh
  • Patent number: 11114228
    Abstract: A magnetic compound having a small dielectric loss and an antenna constituted by the magnetic compound and an electronic device incorporating the antenna are provided by a metal magnetic powder which is well dispersed in a resin having small dielectric loss, and a magnetic powder composite including: a metal magnetic powder; and one or more elements selected from carboxylic acid or its anhydride, aromatic carboxylic acid ester, and a derivative thereof, having a property that real part ?? permeability is 1.45 or more, tan ?? is 0.1 or less, tan ?? is 0.05 or less at a measuring frequency of 2 GHz, when a magnetic powder composite is prepared by adding 5 parts by mass of one or more elements selected from the carboxylic acid or its anhydride, the aromatic carboxylic acid ester, and the derivative thereof to 100 parts by mass of the metal magnetic powder.
    Type: Grant
    Filed: June 1, 2016
    Date of Patent: September 7, 2021
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Toshihiko Ueyama, Masahiro Gotoh, Takayuki Yoshida, Takuyuki Baba
  • Patent number: 11103922
    Abstract: A method for producing a Fe—Co alloy powder suitable for an antenna includes steps, wherein when introducing an oxidizing agent into an aqueous solution containing Fe ions and Co ions to generate crystal nuclei and cause precipitation and growth of a precursor having Fe and Co as components, Co in an amount corresponding to 40% or more of the total amount of Co used for the precipitation reaction is added to the aqueous solution at a time after the start of the crystal nuclei generation and before the end of the precipitation reaction to obtain the precursor. Then, a dried product of the precursor is reduced to obtain a Fe—Co alloy powder. This Fe—Co alloy powder has a mean particle size of 100 nm or less, a coercive force Hc of 52.0 to 78.0 kA/m, and a saturation magnetization ss of 160 Am2/kg or higher.
    Type: Grant
    Filed: March 27, 2015
    Date of Patent: August 31, 2021
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Masahiro Gotoh, Takayuki Yoshida
  • Patent number: 11056257
    Abstract: An object is to provide a magnetic compound excellent in high frequency properties and excellent in mechanical strength, and its related items, using the polyarylene sulfide resin, and to provide a technique regarding the magnetic compound having a metal magnetic powder and a polyarylene sulfide resin, and satisfying both mechanical strength and high frequency properties.
    Type: Grant
    Filed: June 1, 2016
    Date of Patent: July 6, 2021
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takayuki Yoshida, Masahiro Gotoh, Toshihiko Ueyama, Takuyuki Baba, Toru Suzuki, Koji Tanaka
  • Publication number: 20210142934
    Abstract: A Fe—Ni alloy powder has a small particle diameter, can achieve high ?? in a high frequency band, and has high heat resistance. The Fe—Ni alloy powder can be obtained in such a manner that an acidic aqueous solution containing a trivalent Fe ion and a Ni ion is neutralized with an alkali aqueous solution in the presence of a phosphorus-containing ion. This provides a slurry of a precipitate of a hydrated oxide. Then, a silane compound is added to the slurry to coat the precipitate of the hydrated oxide with a hydrolyzate of the silane compound. The precipitate of the hydrated oxide after coating is recovered through solid-liquid separation. The recovered precipitate is heated to provide iron particles coated with a silicon oxide, and then the silicon oxide coating is removed through dissolution.
    Type: Application
    Filed: December 24, 2018
    Publication date: May 13, 2021
    Inventors: Hiroki KANAYA, Masahiro GOTOH
  • Publication number: 20210050132
    Abstract: A silicon oxide-coated iron powder has a small particle diameter, can achieve high in a high frequency band, and has high insulating property. In a method for producing the powder, a silicon alkoxide is added to a slurry containing iron powder having an average particle diameter of 0.25 ?m or more and 0.80 ?m or less and an average axial ratio of 1.5 or less dispersed in a mixed solvent of water and an organic material containing water in an amount of 1% by mass or more and 40% by mass or less. Then, a hydrolysis catalyst for the silicon alkoxide is added to perform silicon oxide coating, the method resulting in a silicon oxide-coated iron powder having the high ?? in a high frequency band and the high insulating property.
    Type: Application
    Filed: January 11, 2019
    Publication date: February 18, 2021
    Inventors: Daisuke KODAMA, Masahiro GOTOH
  • Publication number: 20210012936
    Abstract: There is provided a magnetic material that has an excellent electromagnetic wave absorption performance in a wide frequency range even under low temperature and high temperature environments and that ensures the absorption performance, and provided a magnetic material as a mixture of a magnetic material having positive slope of change in coercive force dependent on temperature, and a magnetic material having negative slope of change in coercive force dependent on temperature.
    Type: Application
    Filed: February 14, 2019
    Publication date: January 14, 2021
    Applicants: The University of Tokyo, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi OHKOSHI, Asuka NAMAI, Marie YOSHIKIYO, Masahiro GOTOH, Toshihiko UEYAMA, Takayuki YOSHIDA
  • Publication number: 20200353536
    Abstract: A Fe—Co alloy powder has a small particle diameter, can achieve high ?? in a high frequency band, and has high heat resistance. The Fe—Co alloy powder can be obtained in such a manner that an acidic aqueous solution containing a trivalent Fe ion and a Co ion is neutralized with an alkali aqueous solution in the presence of a phosphorus-containing ion. This provides a slurry of a precipitate of a hydrated oxide. Then, a silane compound is added to the slurry to coat the precipitate of the hydrated oxide with a hydrolyzate of the silane compound. The precipitate of the hydrated oxide after coating is recovered through solid-liquid separation. The recovered precipitate is heated to provide iron particles coated with a silicon oxide, and then the silicon oxide coating is removed through dissolution.
    Type: Application
    Filed: December 24, 2018
    Publication date: November 12, 2020
    Inventors: Hiroki KANAYA, Masahiro GOTOH
  • Publication number: 20200246867
    Abstract: An iron powder with a small complex particle diameter is used for a molded body having a large real part ?? of the complex relative permeability. A silane compound in an amount of from 0.1 to 0.3 in terms of Si/Fe ratio is added to a slurry containing a hydrated oxide of iron precipitate obtained through neutralization of an acidic aqueous solution containing a trivalent Fe ion with an alkali aqueous solution to coat the precipitate of the hydrated oxide of iron with a hydrolyzate of the silane compound, in which a phosphorus-containing ion in an amount of from 0.003 to 0.1 in terms of P/Fe ratio co-exists in the slurry. The hydrated oxide of iron precipitate after coating is recovered through solid-liquid separation, and then heated to provide iron particles coated with a silicon oxide. The silicon oxide coating is dissolved and removed to provide the iron powder.
    Type: Application
    Filed: September 14, 2018
    Publication date: August 6, 2020
    Inventors: Hidenori YAMAJI, Masahiro GOTOH
  • Publication number: 20190210104
    Abstract: An iron powder and method of making an iron powder. The method includes a step of neutralizing an acidic aqueous solution containing a trivalent iron ion and a phosphorus-containing ion, with an alkali aqueous solution, so as to provide a slurry of a precipitate of a hydrated oxide, or a step of adding a phosphorus-containing ion to a slurry containing a precipitate of a hydrated oxide obtained by neutralizing an acidic aqueous solution containing a trivalent iron ion with an alkali aqueous solution. A silane compound is added to the slurry so as to coat a hydrolysate of the silane compound on the precipitate of the hydrated oxide. The precipitate of the hydrated oxide after coating is recovered through solid-liquid separation, the recovered precipitate is heated to provide iron particles coated with a silicon oxide, and a part or the whole of the silicon oxide coating is dissolved and removed.
    Type: Application
    Filed: July 10, 2017
    Publication date: July 11, 2019
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hidenori YAMAJI, Masahiro GOTOH
  • Publication number: 20180218814
    Abstract: An object is to provide a magnetic compound excellent in high frequency properties and excellent in mechanical strength, and its related items, using the polyarylene sulfide resin, and to provide a technique regarding the magnetic compound having a metal magnetic powder and a polyarylene sulfide resin, and satisfying both mechanical strength and high frequency properties.
    Type: Application
    Filed: June 1, 2016
    Publication date: August 2, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takayuki YOSHIDA, Masahiro GOTOH, Toshihiko UEYAMA, Takuyuki BABA, Toru SUZUKI, Koji TANAKA
  • Publication number: 20180169752
    Abstract: A method for producing a Fe—Co alloy powder suitable for an antenna includes steps, wherein when introducing an oxidizing agent into an aqueous solution containing Fe ions and Co ions to generate crystal nuclei and cause precipitation and growth of a precursor having Fe and Co as components, Co in an amount corresponding to 40% or more of the total amount of Co used for the precipitation reaction is added to the aqueous solution at a time after the start of the crystal nuclei generation and before the end of the precipitation reaction to obtain the precursor. Then, a dried product of the precursor is reduced to obtain a Fe—Co alloy powder. This Fe—Co alloy powder has a mean particle size of 100 nm or less, a coercive force Hc of 52.0 to 78.0 kA/m, and a saturation magnetization ss of 160 Am2/kg or higher.
    Type: Application
    Filed: March 27, 2015
    Publication date: June 21, 2018
    Inventors: Masahiro GOTOH, Takayuki YOSHIDA
  • Publication number: 20180151279
    Abstract: A magnetic compound having a small dielectric loss and an antenna constituted by the magnetic compound and an electronic device incorporating the antenna are provided by a metal magnetic powder which is well dispersed in a resin having small dielectric loss, and a magnetic powder composite including: a metal magnetic powder; and one or more elements selected from carboxylic acid or its anhydride, aromatic carboxylic acid ester, and a derivative thereof, having a property that real part ?? permeability is 1.45 or more, tan ?? is 0.1 or less, tan ?? is 0.05 or less at a measuring frequency of 2 GHz, when a magnetic powder composite is prepared by adding 5 parts by mass of one or more elements selected from the carboxylic acid or its anhydride, the aromatic carboxylic acid ester, and the derivative thereof to 100 parts by mass of the metal magnetic powder.
    Type: Application
    Filed: June 1, 2016
    Publication date: May 31, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Toshihiko UEYAMA, Masahiro GOTOH, Takayuki YOSHIDA, Takuyuki BABA
  • Publication number: 20180033530
    Abstract: An object of the present invention is to provide a magnetic compound excellent in high-frequency property and excellent in mechanical strength and related materials thereof by using at least one of resins selected from syndiotactic polystyrene (SPS) resin and modified polyphenylene ether (m-PPE) resin, including at least one of resins selected from syndiotactic polystyrene (SPS) resin and modified polyphenylene ether (m-PPE) resin, wherein content of the resin is 21 mass % or more.
    Type: Application
    Filed: February 24, 2016
    Publication date: February 1, 2018
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Toshihiko UEYAMA, Masahiro GOTOH, Takayuki YOSHIDA, Takuyuki BABA
  • Patent number: 9683168
    Abstract: To reduce impurity contents of carbon and oxygen not contributing to light emission, then suppress deterioration of emission intensity of a phosphor, and improve emission efficiency of this phosphor. Therefore, there is provided a firing method of nitride or oxynitride phosphors, wherein a crucible 11 made of nitride is used as a firing container, and firing is performed, with this crucible covered with a lid (container 10), to manufacture the phosphor. The phosphor is expressed by a general composition formula MABOoN3-2/3O:Z in which element M is one or more kinds of elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency, O is oxygen, N is nitrogen, and element Z is an activating agent, satisfying o?0.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: June 20, 2017
    Assignees: NICHIA CORPORATION, CITIZEN ELECTRONICS CO., LTD.
    Inventors: Masahiro Gotoh, Kenji Sakane
  • Patent number: 9333158
    Abstract: A spray base material containing an aqueous medium that is gelled by a low-molecular gelator in the medium, wherein the low-molecular gelator includes one or more compounds selected from low-molecular compounds capable of gelling the aqueous medium via self-assembly.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: May 10, 2016
    Assignees: NISSAN CHEMICAL INDUSTRIES, LTD., KYUSHU UNIVERSITY
    Inventors: Misao Miyamoto, Takehisa Iwama, Nobuhide Miyachi, Masahiro Gotoh