Patents by Inventor Hitoshi Nagayama

Hitoshi Nagayama 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: 20240376012
    Abstract: Provided is a powder composition that includes, as a matrix, a zirconia having a high content of a stabilizing element and that can provide, through short-time sintering, a sintered body satisfying translucency and mechanical strength required for dental prosthetic materials, in particular, prosthetic anterior teeth. Provided is a powder composition including two or more stabilized zirconias having different contents of a stabilizing element, in which the powder composition has a content of the stabilizing element of more than 4.0 mol % and 5.8 mol % or less, a rate of change in thermal shrinkage rate per unit temperature at 1,300° C. is 0.07% C?1 or less, and the contents of the stabilizing element of the stabilized zirconias are each 8.0 mol % or less.
    Type: Application
    Filed: September 15, 2022
    Publication date: November 14, 2024
    Applicant: TOSOH CORPORATION
    Inventors: Sho AZECHI, Yuya HIGUCHI, Hiroyuki FUJISAKI, Hitoshi NAGAYAMA, Kiyotaka KAWAMURA
  • Publication number: 20240217881
    Abstract: Provided is a method for manufacturing a sintered body that uses atmospheric pressure sintering in an atmospheric atmosphere and allows the time required for sintering to be reduced. The method for manufacturing the sintered body includes subjecting a sintered body of zirconia containing a coloring element to heat treatment at 600° C. or higher and 1200° C. or lower.
    Type: Application
    Filed: April 25, 2022
    Publication date: July 4, 2024
    Applicant: TOSOH CORPORATION
    Inventors: Yuki USHIO, Hiroyuki FUJISAKI, Yuya HIGUCHI, Hitoshi NAGAYAMA
  • Publication number: 20240101483
    Abstract: To provide at least one of: a powder composition from which a calcined body with similar processability can be produced without requiring the application of different forming conditions and calcination conditions for each composition; a method for producing the powder composition; a calcined body produced from the powder composition; a method for producing the calcined body; and uses thereof. A powder composition including: two or more types of zirconia in which a lanthanoid rare-earth element is dissolved; a transition metal element other than zirconium and hafnium; and a remainder composed of zirconia stabilized only by one or more selected from the group consisting of yttrium, calcium and magnesium, wherein a different lanthanoid rare-earth element is dissolved in each zirconia in which the lanthanoid rare-earth element is dissolved, and a transition metal element content is 1500 ppm or less.
    Type: Application
    Filed: January 19, 2022
    Publication date: March 28, 2024
    Applicant: TOSOH CORPORATION
    Inventors: Sho AZECHI, Yuki USHIO, Takahiro SHIMIZU, Yuya HIGUCHI, Hitoshi NAGAYAMA, Hiroyuki FUJISAKI, Kenji IMAI, Risa KAWASHIMA
  • Publication number: 20230391674
    Abstract: A sintered body comprises zirconia including a stabilizer element dissolved therein and a lanthanoid element dissolved therein, the lanthanoid element having an ionic radius larger than the atomic radius of zirconium. The content of monoclinic zirconia after a hydrothermal treatment at 140° C. for 24 hours is less than 25%. The sintered body includes a spinel compound including aluminum and a coloring element.
    Type: Application
    Filed: May 26, 2023
    Publication date: December 7, 2023
    Applicant: TOSOH CORPORATION
    Inventors: Hitoshi NAGAYAMA, Hajime FUNAKOSHI, Satoshi TSUCHIYA
  • Patent number: 11746055
    Abstract: A zirconia powder is provided comprising a yttria source and zirconia, wherein a content of the yttria source is 4.5 mol % or more and 6.5 mol % or less and the remainder is zirconia, a ratio of a total of tetragonal and cubic crystals to an entire crystal phase of zirconia is 90% or less, a BET specific surface area is 7.5 m2/g or more and 15 m2/g or less, and an average crystallite size is 325 ? or greater. The powders are useful in producing sintered bodies having the mechanical strength and the translucency desired for use in dental prosthetic materials, and precursors thereof.
    Type: Grant
    Filed: September 14, 2022
    Date of Patent: September 5, 2023
    Assignee: TOSOH CORPORATION
    Inventors: Akiko Ito, Ayako Watanabe, Sho Azechi, Hitoshi Nagayama, Hiroyuki Fujisaki
  • Publication number: 20230028313
    Abstract: A zirconia powder is provided comprising a yttria source and zirconia, wherein a content of the yttria source is 4.5 mol % or more and 6.5 mol % or less and the remainder is zirconia, a ratio of a total of tetragonal and cubic crystals to an entire crystal phase of zirconia is 90% or less, a BET specific surface area is 7.5 m2/g or more and 15 m2/g or less, and an average crystallite size is 325 ? or greater. The powders are useful in producing sintered bodies having the mechanical strength and the translucency desired for use in dental prosthetic materials, and precursors thereof.
    Type: Application
    Filed: September 14, 2022
    Publication date: January 26, 2023
    Applicant: TOSOH CORPORATION
    Inventors: Akiko ITO, Ayako WATANABE, Sho AZECHI, Hitoshi NAGAYAMA, Hiroyuki FUJISAKI
  • Publication number: 20230014792
    Abstract: To provide a sintered body with improved impact resistance due to impact absorption through plastic deformation before brittle fracture for an impact exceeding the fracture resistance of the sintered body, and/or a method for producing the sintered body. A sintered body including: zirconia containing a stabilizer; and a region in which an impact mark is formed when an impact force is applied.
    Type: Application
    Filed: December 8, 2020
    Publication date: January 19, 2023
    Applicant: TOSOH CORPORATION
    Inventors: Taku FUKIAGE, Hitoshi NAGAYAMA, Kenta KAWAMURA, Takashi TSUKIMORI, Hiroyuki FUJISAKI
  • Patent number: 11479511
    Abstract: A zirconia sintered body is provided and includes yttria and zirconia, containing yttria by a content ranging from 4.5 mol % or more to 6.5 mol % or less and zirconia as the remainder, the total light transmittance of a 1-mm thick sample measured in compliance with JIS K 7361-1 being 46.5% or higher, the three-point bending strength being 700 MPa or higher, and a ratio of an integrated value for the total light transmittance to an integrated value for the parallel light transmittance of a 1-mm thick sample measured at the measurement wavelength ranging from 400 to 700 nm being 1.3% or less.
    Type: Grant
    Filed: September 30, 2020
    Date of Patent: October 25, 2022
    Assignee: TOSOH CORPORATION
    Inventors: Akiko Ito, Ayako Watanabe, Sho Azechi, Hitoshi Nagayama, Hiroyuki Fujisaki
  • Publication number: 20220332649
    Abstract: A sintered body that includes zirconia containing a stabilizing element; and a plastic deformation region, wherein the stabilizing element includes at least one rare-earth element other than yttrium, and the stabilizing element content is 1.5% or more by mole and less than 3.0% by mole.
    Type: Application
    Filed: April 11, 2022
    Publication date: October 20, 2022
    Applicant: TOSOH CORPORATION
    Inventors: Kenta KAWAMURA, Taku FUKIAGE, So NISHIYAMA, Hitoshi NAGAYAMA
  • Publication number: 20210403387
    Abstract: A complex sintered body includes a lamination of a layer composed of a zirconia sintered body containing 0.5% or more by mole and less than 4% by mole of an oxide of cerium in terms of CeO2, 2% or more by mole and less than 6% by mole of yttria and 0.1% or more by mass and less than 2% by mass of an oxide of aluminum; and at least one of a layer composed of a zirconia-based sintered body containing 2.0% or more by mass and 20.0% or less by mass of an oxide of aluminum, and a layer composed of a zirconia-based sintered body containing 2% or more by mole and less than 6% by mole of yttria and a coloring agent.
    Type: Application
    Filed: August 7, 2019
    Publication date: December 30, 2021
    Applicant: TOSOH CORPORATION
    Inventors: Satoshi TSUCHIYA, Hiroyuki FUJISAKI, Hitoshi NAGAYAMA
  • Patent number: 11124457
    Abstract: A zirconia sintered body comprising 3.0 wt % or more and 30.0 wt % or less of aluminum in terms of Al2O3 and a remainder is zirconia containing 2 mol % or more and 4 mol % or less of erbia, in which the zirconia sintered body includes grains of aluminum oxide, and a total light transmittance with respect to a D65 light source at a sample thickness of 1.0 mm is 10% or less.
    Type: Grant
    Filed: February 14, 2020
    Date of Patent: September 21, 2021
    Assignee: TOSOH CORPORATION
    Inventors: Hitoshi Nagayama, Hajime Funakoshi, Hiroyuki Fujisaki, Takashi Tsukimori
  • Publication number: 20210101838
    Abstract: A zirconia sintered body is provided and includes yttria and zirconia, containing yttria by a content ranging from 4.5 mol % or more to 6.5 mol % or less and zirconia as the remainder, the total light transmittance of a 1-mm thick sample measured in compliance with JIS K 7361-1 being 46.5% or higher, the three-point bending strength being 700 MPa or higher, and a ratio of an integrated value for the total light transmittance to an integrated value for the parallel light transmittance of a 1-mm thick sample measured at the measurement wavelength ranging from 400 to 700 nm being 1.3% or less.
    Type: Application
    Filed: September 30, 2020
    Publication date: April 8, 2021
    Applicant: TOSOH CORPORATION
    Inventors: Akiko ITO, Ayako WATANABE, Sho AZECHI, Hitoshi NAGAYAMA, Hiroyuki FUJISAKI
  • Patent number: 10858293
    Abstract: A zirconia sintered body contains aluminum, cobalt, and manganese and a remaining portion consisting of yttria-containing zirconia. In an oxide exchange, aluminum content is 5.0 wt % or more and 30.0 wt % or less, cobalt content is 0.1 wt % or more and 2.0 wt % or less, and manganese content is 0.5 wt % or more and 7.0 wt % or less.
    Type: Grant
    Filed: March 29, 2019
    Date of Patent: December 8, 2020
    Assignee: TOSOH CORPORATION
    Inventors: Hitoshi Nagayama, Hajime Funakoshi, Hiroyuki Fujisaki
  • Publication number: 20200262759
    Abstract: A zirconia sintered body comprising 3.0 wt % or more and 30.0 wt % or less of aluminum in terms of Al2O3 and a remainder is zirconia containing 2 mol % or more and 4 mol % or less of erbia, in which the zirconia sintered body includes grains of aluminum oxide, and a total light transmittance with respect to a D65 light source at a sample thickness of 1.0 mm is 10% or less.
    Type: Application
    Filed: February 14, 2020
    Publication date: August 20, 2020
    Applicant: TOSOH CORPORATION
    Inventors: Hitoshi NAGAYAMA, Hajime FUNAKOSHI, Hiroyuki FUJISAKI, Takashi TSUKIMORI
  • Publication number: 20190300438
    Abstract: A zirconia sintered body contains aluminum, cobalt, and manganese and a remaining portion consisting of yttria-containing zirconia. In an oxide exchange, aluminum content is 5.0 wt % or more and 30.0 wt % or less, cobalt content is 0.1 wt % or more and 2.0 wt % or less, and manganese content is 0.5 wt % or more and 7.0 wt % or less.
    Type: Application
    Filed: March 29, 2019
    Publication date: October 3, 2019
    Applicant: TOSOH CORPORATION
    Inventors: Hitoshi NAGAYAMA, Hajime FUNAKOSHI, Hiroyuki FUJISAKI
  • Patent number: 9919971
    Abstract: To provide a zirconia sintered body which has at least two different color tones such as white and black, and which has no color bleeding or no gap between sintered bodies. A zirconia sintered body comprising a first zirconia sintered body and a second zirconia sintered body, characterized in that the first zirconia sintered body is a zirconia sintered body containing aluminum oxide; the second zirconia sintered body is a zirconia sintered body containing a spinel oxide; a bonding plane is formed between the first zirconia sintered body and the second zirconia sintered body; and it has no gap or no color bleeding at the bonding plane.
    Type: Grant
    Filed: December 25, 2014
    Date of Patent: March 20, 2018
    Assignee: TOSOH CORPORATION
    Inventors: Hitoshi Nagayama, Naoki Shinozaki, Takeshi Ito, Koji Tsukuma, Shoichi Yamauchi
  • Patent number: 9920420
    Abstract: Provided is an apparatus that includes a molding die for producing a sintered body. The molding die is configured for cold isostatic pressing and includes a knockdown mold frame comprised of plural frame members and a bottom plate provided in contact with the knockdown mold frame. An upper punch is provided to be movable along the inner surface of the knockdown mold frame. The frame members configured to be movable relative to each other to accommodate an expansion of a green body which takes place at the time of reducing the pressure after the completion of pressing.
    Type: Grant
    Filed: July 21, 2015
    Date of Patent: March 20, 2018
    Assignee: TOSOH CORPORATION
    Inventors: Kenichi Itoh, Masami Mesuda, Hitoshi Nagayama, Tetsuo Shibutami, Shunsuke Yatsunami
  • Publication number: 20160347666
    Abstract: To provide a zirconia sintered body which has at least two different color tones such as white and black, and which has no color bleeding or no gap between sintered bodies. A zirconia sintered body comprising a first zirconia sintered body and a second zirconia sintered body, characterized in that the first zirconia sintered body is a zirconia sintered body containing aluminum oxide; the second zirconia sintered body is a zirconia sintered body containing a spinel oxide; a bonding plane is formed between the first zirconia sintered body and the second zirconia sintered body; and it has no gap or no color bleeding at the bonding plane.
    Type: Application
    Filed: December 25, 2014
    Publication date: December 1, 2016
    Applicant: TOSOH CORPORATION
    Inventors: Hitoshi NAGAYAMA, Naoki SHINOZAKI, Takeshi ITO, Koji TSUKUMA, Shoichi YAMAUCHI
  • Publication number: 20150368791
    Abstract: Provided is an apparatus that includes a molding die for producing a sintered body. The molding die is configured for cold isostatic pressing and includes a knockdown mold frame comprised of plural frame members and a bottom plate provided in contact with the knockdown mold frame. An upper punch is provided to be movable along the inner surface of the knockdown mold frame. The frame members configured to be movable relative to each other to accommodate an expansion of a green body which takes place at the time of reducing the pressure after the completion of pressing.
    Type: Application
    Filed: July 21, 2015
    Publication date: December 24, 2015
    Applicant: TOSOH CORPORATION
    Inventors: Kenichi ITOH, Masami MESUDA, Hitoshi NAGAYAMA, Tetsuo SHIBUTAMI, Shunsuke YATSUNAMI
  • Publication number: 20130213801
    Abstract: Provided is an apparatus that includes a molding die for producing a sintered body. The molding die is configured for cold isostatic pressing and includes a knockdown mold frame comprised of plural frame members and a bottom plate provided in contact with the knockdown mold frame. An upper punch is provided to be movable along the inner surface of the knockdown mold frame. The frame members configured to be movable relative to each other to accommodate an expansion of a green body which takes place at the time of reducing the pressure after the completion of pressing.
    Type: Application
    Filed: March 18, 2013
    Publication date: August 22, 2013
    Inventors: Kenichi ITOH, Masami MESUDA, Hitoshi NAGAYAMA, Tetsuo SHIBUTAMI, Shunsuke YATSUNAMI