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: 20240376012Abstract: 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: ApplicationFiled: September 15, 2022Publication date: November 14, 2024Applicant: TOSOH CORPORATIONInventors: Sho AZECHI, Yuya HIGUCHI, Hiroyuki FUJISAKI, Hitoshi NAGAYAMA, Kiyotaka KAWAMURA
-
Publication number: 20240217881Abstract: 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: ApplicationFiled: April 25, 2022Publication date: July 4, 2024Applicant: TOSOH CORPORATIONInventors: Yuki USHIO, Hiroyuki FUJISAKI, Yuya HIGUCHI, Hitoshi NAGAYAMA
-
Publication number: 20240101483Abstract: 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: ApplicationFiled: January 19, 2022Publication date: March 28, 2024Applicant: TOSOH CORPORATIONInventors: Sho AZECHI, Yuki USHIO, Takahiro SHIMIZU, Yuya HIGUCHI, Hitoshi NAGAYAMA, Hiroyuki FUJISAKI, Kenji IMAI, Risa KAWASHIMA
-
Publication number: 20230391674Abstract: 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: ApplicationFiled: May 26, 2023Publication date: December 7, 2023Applicant: TOSOH CORPORATIONInventors: Hitoshi NAGAYAMA, Hajime FUNAKOSHI, Satoshi TSUCHIYA
-
Patent number: 11746055Abstract: 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: GrantFiled: September 14, 2022Date of Patent: September 5, 2023Assignee: TOSOH CORPORATIONInventors: Akiko Ito, Ayako Watanabe, Sho Azechi, Hitoshi Nagayama, Hiroyuki Fujisaki
-
Publication number: 20230028313Abstract: 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: ApplicationFiled: September 14, 2022Publication date: January 26, 2023Applicant: TOSOH CORPORATIONInventors: Akiko ITO, Ayako WATANABE, Sho AZECHI, Hitoshi NAGAYAMA, Hiroyuki FUJISAKI
-
Publication number: 20230014792Abstract: 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: ApplicationFiled: December 8, 2020Publication date: January 19, 2023Applicant: TOSOH CORPORATIONInventors: Taku FUKIAGE, Hitoshi NAGAYAMA, Kenta KAWAMURA, Takashi TSUKIMORI, Hiroyuki FUJISAKI
-
Patent number: 11479511Abstract: 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: GrantFiled: September 30, 2020Date of Patent: October 25, 2022Assignee: TOSOH CORPORATIONInventors: Akiko Ito, Ayako Watanabe, Sho Azechi, Hitoshi Nagayama, Hiroyuki Fujisaki
-
Publication number: 20220332649Abstract: 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: ApplicationFiled: April 11, 2022Publication date: October 20, 2022Applicant: TOSOH CORPORATIONInventors: Kenta KAWAMURA, Taku FUKIAGE, So NISHIYAMA, Hitoshi NAGAYAMA
-
Publication number: 20210403387Abstract: 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: ApplicationFiled: August 7, 2019Publication date: December 30, 2021Applicant: TOSOH CORPORATIONInventors: Satoshi TSUCHIYA, Hiroyuki FUJISAKI, Hitoshi NAGAYAMA
-
Patent number: 11124457Abstract: 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: GrantFiled: February 14, 2020Date of Patent: September 21, 2021Assignee: TOSOH CORPORATIONInventors: Hitoshi Nagayama, Hajime Funakoshi, Hiroyuki Fujisaki, Takashi Tsukimori
-
Publication number: 20210101838Abstract: 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: ApplicationFiled: September 30, 2020Publication date: April 8, 2021Applicant: TOSOH CORPORATIONInventors: Akiko ITO, Ayako WATANABE, Sho AZECHI, Hitoshi NAGAYAMA, Hiroyuki FUJISAKI
-
Patent number: 10858293Abstract: 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: GrantFiled: March 29, 2019Date of Patent: December 8, 2020Assignee: TOSOH CORPORATIONInventors: Hitoshi Nagayama, Hajime Funakoshi, Hiroyuki Fujisaki
-
Publication number: 20200262759Abstract: 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: ApplicationFiled: February 14, 2020Publication date: August 20, 2020Applicant: TOSOH CORPORATIONInventors: Hitoshi NAGAYAMA, Hajime FUNAKOSHI, Hiroyuki FUJISAKI, Takashi TSUKIMORI
-
Publication number: 20190300438Abstract: 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: ApplicationFiled: March 29, 2019Publication date: October 3, 2019Applicant: TOSOH CORPORATIONInventors: Hitoshi NAGAYAMA, Hajime FUNAKOSHI, Hiroyuki FUJISAKI
-
Patent number: 9919971Abstract: 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: GrantFiled: December 25, 2014Date of Patent: March 20, 2018Assignee: TOSOH CORPORATIONInventors: Hitoshi Nagayama, Naoki Shinozaki, Takeshi Ito, Koji Tsukuma, Shoichi Yamauchi
-
Patent number: 9920420Abstract: 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: GrantFiled: July 21, 2015Date of Patent: March 20, 2018Assignee: TOSOH CORPORATIONInventors: Kenichi Itoh, Masami Mesuda, Hitoshi Nagayama, Tetsuo Shibutami, Shunsuke Yatsunami
-
Publication number: 20160347666Abstract: 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: ApplicationFiled: December 25, 2014Publication date: December 1, 2016Applicant: TOSOH CORPORATIONInventors: Hitoshi NAGAYAMA, Naoki SHINOZAKI, Takeshi ITO, Koji TSUKUMA, Shoichi YAMAUCHI
-
Publication number: 20150368791Abstract: 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: ApplicationFiled: July 21, 2015Publication date: December 24, 2015Applicant: TOSOH CORPORATIONInventors: Kenichi ITOH, Masami MESUDA, Hitoshi NAGAYAMA, Tetsuo SHIBUTAMI, Shunsuke YATSUNAMI
-
Publication number: 20130213801Abstract: 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: ApplicationFiled: March 18, 2013Publication date: August 22, 2013Inventors: Kenichi ITOH, Masami MESUDA, Hitoshi NAGAYAMA, Tetsuo SHIBUTAMI, Shunsuke YATSUNAMI