Patents by Inventor Yuji Tawarazako

Yuji Tawarazako 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).

  • Patent number: 11059997
    Abstract: A polishing composition comprising an abrasive grain; a modified microfibril cellulose in which at least a part of the cellulose units has a hydroxyl group at the C6 position oxidized to a carboxyl group; and a dispersion medium, wherein each content of Na and K is 100 ppm or less relative to the solids weight.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: July 13, 2021
    Assignee: JGC CATALYSTS AND CHEMICALS LTD.
    Inventors: Michio Komatsu, Yukihiro Iwasaki, Hiroyasu Nishida, Yuji Tawarazako, Kazuhiro Nakayama
  • Patent number: 10920120
    Abstract: A ceria composite particle dispersion has ceria composite particles having an average particle size of 50 to 350 nm and having the features described below. Each ceria composite particle has a mother particle, a cerium-containing silica layer on the surface thereof, and child particles dispersed inside the cerium-containing silica layer, the mother particles being amorphous silica-based and the child particles being crystalline ceria-based. The child particles have a coefficient of variation (CV value) in a particle size distribution of 14 to 40%. The ceria composite particles have a mass ratio of silica to ceria of 100:11-316. Only the crystal phase of ceria is detected when the ceria composite particles are subjected to X-ray diffraction. The average crystallite size of the crystalline ceria measured by subjecting the ceria composite particles to X-ray diffraction is 10 to 25 nm.
    Type: Grant
    Filed: October 6, 2017
    Date of Patent: February 16, 2021
    Assignee: JGC CATALYSTS AND CHEMICALS LTD.
    Inventors: Michio Komatsu, Yuji Tawarazako, Shinya Usuda, Kazuhiro Nakayama, Shota Kawakami
  • Patent number: 10844259
    Abstract: Disclosed is a silica-based composite fine particle dispersion including a silica-based composite fine particle which comprises a mother particle containing amorphous silica as a main component with a child particle containing crystalline ceria as a main component on a surface thereof. Features of the silica-based composite fine particle include a silica to ceria mass ratio of 100:11 to 316, and when subjected to X-ray diffraction, only the crystalline phase of ceria is detected, and when subjected to X-ray diffraction for measurement, the crystalline ceria has a crystallite diameter of 10 to 25 nm.
    Type: Grant
    Filed: April 5, 2017
    Date of Patent: November 24, 2020
    Assignee: JGC Catalysts and Chemicals Ltd.
    Inventors: Yuji Tawarazako, Michio Komatsu, Kazuhiro Nakayama, Yukihiro Iwasaki, Yoshinori Wakamiya, Shota Kawakami, Shinya Usuda
  • Patent number: 10730755
    Abstract: A subject of this invention is to provide a dispersion liquid of a silica-based composite particle, which can rapidly polish silica film, Si wafer or even hard-to-process material, can concurrently achieve high surface accuracy (less scratches, etc.), and can suitably be used for surface polishing of semiconductor devices including semiconductor substrate and wiring board, by virtue of its impurity-free nature. The subject is solved by a dispersion liquid of a silica-based composite particle that contains a silica-based composite particle that has a core particle mainly composed of amorphous silica, and bound thereto a ceria particle mainly composed of crystalline ceria, further has a silica film that covers them.
    Type: Grant
    Filed: March 30, 2016
    Date of Patent: August 4, 2020
    Assignee: JGC Catalysts and Chemicals Ltd.
    Inventors: Yuji Tawarazako, Yoshinori Wakamiya, Shingo Kashiwada, Kazuaki Inoue, Kazuhiro Nakayama, Michio Komatsu
  • Publication number: 20200087554
    Abstract: Aiming at providing a ceria-based composite particle dispersion capable of polishing silica film, Si wafer or even hard-to-process material at high polishing rate, and can give high surface accuracy, disclosed is a ceria-based composite particle dispersion that contains a ceria-based composite particle that has an average particle size of 50 to 350 nm, to solve the aforementioned problem, featured by that the ceria-based composite particle has a mother particle, a cerium-containing silica layer, a child particle, and an easily soluble silica-containing layer; the mother particle contains amorphous silica as a major ingredient; the child particle contains crystalline ceria as a major ingredient; ratio of the mass of the easily soluble silica-containing layer relative to the mass of the ceria-based composite particle falls in a specific range; mass ratio of silica and ceria in the ceria-based composite particle falls in a specific range; the ceria-based composite particle, when analyzed by X-ray diffractometry,
    Type: Application
    Filed: May 23, 2018
    Publication date: March 19, 2020
    Inventors: Michio Komatsu, Hiroyasu Nishida, Yuji Tawarazako, Shinya Usuda, Kazuhiro Nakayama
  • Publication number: 20190367777
    Abstract: A polishing composition comprising an abrasive grain; a modified microfibril cellulose in which at least a part of the cellulose units has a hydroxyl group at the C6 position oxidized to a carboxyl group; and a dispersion medium, wherein each content of Na and K is 100 ppm or less relative to the solids weight.
    Type: Application
    Filed: December 28, 2017
    Publication date: December 5, 2019
    Applicant: JGC CATALYSTS AND CHEMICALS LTD.
    Inventors: Michio KOMATSU, Yukihiro IWASAKI, Hiroyasu NISHIDA, Yuji TAWARAZAKO, Kazuhiro NAKAYAMA
  • Publication number: 20190248668
    Abstract: A ceria composite particle dispersion has ceria composite particles having an average particle size of 50 to 350 nm and having the features described below. Each ceria composite particle has a mother particle, a cerium-containing silica layer on the surface thereof, and child particles dispersed inside the cerium-containing silica layer, the mother particles being amorphous silica-based and the child particles being crystalline ceria-based. The child particles have a coefficient of variation (CV value) in a particle size distribution of 14 to 40%. The ceria composite particles have a mass ratio of silica to ceria of 100:11-316. Only the crystal phase of ceria is detected when the ceria composite particles are subjected to X-ray diffraction. The average crystallite size of the crystalline ceria measured by subjecting the ceria composite particles to X-ray diffraction is 10 to 25 nm.
    Type: Application
    Filed: October 6, 2017
    Publication date: August 15, 2019
    Applicant: JGC CATALYSTS AND CHEMICALS LTD.
    Inventors: Michio KOMATSU, Yuji TAWARAZAKO, Shinya USUDA, Kazuhiro NAKAYAMA, Shota KAWAKAMI
  • Publication number: 20190153279
    Abstract: Disclosed is a silica-based composite fine particle dispersion including a silica-based composite fine particle which comprises a mother particle containing amorphous silica as a main component with a child particle containing crystalline ceria as a main component on a surface thereof. Features of the silica-based composite fine particle include a silica to ceria mass ratio of 100:11 to 316, and when subjected to X-ray diffraction, only the crystalline phase of ceria is detected, and when subjected to X-ray diffraction for measurement, the crystalline ceria has a crystallite diameter of 10 to 25 nm.
    Type: Application
    Filed: April 5, 2017
    Publication date: May 23, 2019
    Inventors: Yuji Tawarazako, Michio Komatsu, Kazuhiro Nakayama, Yukihiro Iwasaki, Yoshinori Wakamiya, Shota Kawakami, Shinya Usuda
  • Publication number: 20180105428
    Abstract: A subject of this invention is to provide a dispersion liquid of a silica-based composite particle, which can rapidly polish silica film, Si wafer or even hard-to-process material, can concurrently achieve high surface accuracy (less scratches, etc.), and can suitably be used for surface polishing of semiconductor devices including semiconductor substrate and wiring board, by virtue of its impurity-free nature. The subject is solved by a dispersion liquid of a silica-based composite particle that contains a silica-based composite particle that has a core particle mainly composed of amorphous silica, and bound thereto a ceria particle mainly composed of crystalline ceria, further has a silica film that covers them.
    Type: Application
    Filed: March 30, 2016
    Publication date: April 19, 2018
    Inventors: Yuji Tawarazako, Yoshinori Wakamiya, Shingo Kashiwada, Kazuaki Inoue, Kazuhiro Nakayama, Michio Komatsu
  • Patent number: 8748001
    Abstract: Modified zirconia fine particles which are stable in an acidic region as well as in an alkaline region, and which may be readily adjusted in refractive index in a predetermined range are disclosed. Also disclosed is a substrate with a hard coat film excellent in adhesiveness with the substrate, abrasion resistance, scratch strength, pencil hardness and the like without interference fringes and a coating solution which may form the hard coat film. The substrate with a hard coat film is composed of composite oxide particles formed on at least one surface of the substrate and a matrix component, wherein the composite oxide particles are composite oxide particles having a core-shell structure composed of a core formed from zirconium oxide and a shell formed from antimony pentoxide and/or silica.
    Type: Grant
    Filed: August 29, 2008
    Date of Patent: June 10, 2014
    Assignee: JGC Catalysts and Chemicals Ltd.
    Inventors: Ryo Muraguchi, Mitsuaki Kumazawa, Wataru Futagami, Yuji Tawarazako, Masayuki Matsuda, Toshiharu Hirai
  • Patent number: 8118898
    Abstract: The present invention provides a sol of spinous silica-based particles in which silica-based particles having peculiar forms, spinous forms are dispersed in a solvent. The spinous silica-based particles have verrucous projections formed on surfaces of spherical silica-based particles. In the spinous particles, a value of the surface roughness (SA1/SA2, SA1 indicating a specific surface area measured by the BET method or the Sears method and SA2 indicating a specific surface area converted from an average particle diameter (D2) measured by the image analysis method) is in the range from 1.7 to 10. Furthermore the average diameter (D2) measured by the image analysis method is in the range from 7 to 150 nm.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: February 21, 2012
    Assignee: JGC Catalysts and Chemicals Ltd.
    Inventors: Yoshinori Wakamiya, Hiroyasu Nishida, Yuji Tawarazako, Kazuaki Inoue, Osamu Yoshida, Akira Nakashima
  • Publication number: 20090061183
    Abstract: The present invention provides modified zirconia fine particles which are stable in an acidic region as well as in an alkaline region, and which may be readily adjusted in refractive index in a predetermined range. The present invention further provides a substrate with a hard coat film excellent in adhesiveness with the substrate, abrasion resistance, scratch strength, pencil hardness and the like without interference fringes and a coating solution which may form the hard coat film. The substrate with a hard coat film is composed of composite oxide particles formed on at least one surface of the substrate and a matrix component, wherein the composite oxide particles are composite oxide particles having a core-shell structure composed of a core formed from zirconium oxide and a shell formed from antimony pentoxide and/or silica.
    Type: Application
    Filed: August 29, 2008
    Publication date: March 5, 2009
    Applicant: JGC CATALYSTS AND CHEMICALS LTD.
    Inventors: Ryo Muraguchi, Mitsuaki Kumazawa, Wataru Futagami, Yuji Tawarazako, Masayuki Matsuda, Toshiharu Hirai
  • Publication number: 20080086951
    Abstract: The present invention provides a sol of spinous silica-based particles in which silica-based particles having peculiar forms, spinous forms are dispersed in a solvent. The spinous silica-based particles have verrucous projections formed on surfaces of spherical silica-based particles. In the spinous particles, a value of the surface roughness (SA1/SA2, SA1 indicating a specific surface area measured by the BET method or the Sears method and SA2 indicating a specific surface area converted from an average particle diameter (D2) measured by the image analysis method) is in the range from 1.7 to 10. Furthermore the average diameter (D2) measured by the image analysis method is in the range from 7 to 150 nm.
    Type: Application
    Filed: October 11, 2007
    Publication date: April 17, 2008
    Applicant: CATALYSTS & CHEMICALS INDUSTRIES CO., LTD
    Inventors: Yoshinori Wakamiya, Hiroyasu Nishida, Yuji Tawarazako, Kazuaki Inoue, Osamu Yoshida, Akira Nakashima
  • Patent number: 6180030
    Abstract: A coating liquid for forming a transparent conductive coating, comprising fine particles of a composite metal having an average particle size of 1 to 200 nm and a polar solvent. The above composite metal particles are preferably composed of an alloy of a plurality of metals or comprise fine metal particles or the fine alloy particles covered by a metal having a standard hydrogen electrode potential higher than that of the metal or alloy metal. A substrate with transparent conductive coating comprising a transparent conductive fine particle layer including the composite metal particles and a transparent coating disposed on the transparent conductive fine particle layer. A display device comprising a front panel composed of the above substrate with transparent conductive coating, the transparent conductive coating being formed at an outer surface of the front panel.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: January 30, 2001
    Assignee: Catalysts & Chemicals Industries Co., Ltd.
    Inventors: Toshiharu Hirai, Michio Komatsu, Mitsuaki Kumazawa, Yuji Tawarazako
  • Patent number: 6136228
    Abstract: A coating liquid for forming a transparent conductive coating, comprising fine particles of a composite metal having an average particle size of 1 to 200 nm and a polar solvent. The above composite metal particles are preferably composed of an alloy of a plurality of metals or comprise fine metal particles or the fine alloy particles covered by a metal having a standard hydrogen electrode potential higher than that of the metal or alloy metal.A substrate with transparent conductive coating comprising a transparent conductive fine particle layer including the composite metal particles and a transparent coating disposed on the transparent conductive fine particle layer.A display device comprising a front panel composed of the above substrate with transparent conductive coating, the transparent conductive coating being formed at an outer surface of the front panel.
    Type: Grant
    Filed: September 25, 1997
    Date of Patent: October 24, 2000
    Assignee: Catalysts & Chemicals Industries Co., Ltd.
    Inventors: Toshiharu Hirai, Michio Komatsu, Mitsuaki Kumazawa, Yuji Tawarazako