Patents by Inventor Katsuya Yamagiwa

Katsuya Yamagiwa 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: 20200153019
    Abstract: An electrochemical cell including a solid electrolyte layer containing ZrO2 containing a first rare earth element; a cathode disposed on one side of the solid electrolyte layer; and an anode disposed on the other side of the solid electrolyte layer. The anode contains CeO2 containing a second rare earth element and Ni or an Ni-containing alloy. The electrochemical cell further includes an intermediate layer disposed between the solid electrolyte layer and the anode. The intermediate layer contains a solid solution containing Zr, Ce, the first rare earth element, and the second rare earth element. Also disclosed is an electrochemical stack including a plurality of the electrochemical cells, where the electrochemical stack is a solid oxide fuel cell stack or a solid oxide electrolysis cell stack.
    Type: Application
    Filed: May 17, 2018
    Publication date: May 14, 2020
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Keisuke YAMADA, Yoshihiro FUNAHASHI, Katsuya YAMAGIWA
  • Patent number: 9828296
    Abstract: A lead-free piezoelectric ceramic composition mainly includes a first crystal phase (KNN phase) and a second crystal phase (NTK phase). In the first crystal phase (KNN phase), a plurality of crystal grains formed of an alkali niobate/tantalate perovskite oxide having piezoelectric characteristics is bound to each other in a deposited state. The second crystal phase (NTK phase) is formed of a compound containing titanium (Ti) and fills spaces between the crystal grains in the first crystal phase.
    Type: Grant
    Filed: July 4, 2012
    Date of Patent: November 28, 2017
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Masato Yamazaki, Takayuki Matsuoka, Kazuaki Kitamura, Hideto Yamada, Toshiaki Kurahashi, Katsuya Yamagiwa, Kazushige Ohbayashi
  • Publication number: 20160164108
    Abstract: A solid oxide fuel cell, a method of producing the same, a fuel cell stack, and a solid oxide fuel battery. The fuel cell including a solid electrolyte layer, a cathode layer formed on one surface thereof and which contains at least Sr, an anode layer which is formed on the other surface of the solid electrolyte layer, and an intermediate layer formed between the solid electrolyte layer and the cathode layer. At least a part of the intermediate layer is an element diffusion prevention layer; the element diffusion prevention layer being formed of a complex oxide containing at least one rare earth element and Zr; and after having been subjected to accelerated heating in air at 1,000° C. for 100 hr, the element diffusion prevention layer has a thickness of 600 nm or more to 2,000 nm or less and a percent Sr coverage of 90% or lower.
    Type: Application
    Filed: June 27, 2014
    Publication date: June 9, 2016
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Toshihiro MATSUNO, Chisato MURASE, Yuko HISANO, Katsuya YAMAGIWA
  • Patent number: 9006959
    Abstract: A lead-free piezoelectric ceramic composition includes a first crystal phase of alkali niobate/tantalate type perovskite oxide having piezoelectric properties and a second crystal phase of A-Ti—B—O composite oxide (where the element A is an alkali metal; the element B is at least one of Nb and Ta; and the contents of the element A, the element B and Ti are not zero). Examples of the second crystal phase are those represented by A1?xTi1?xB1+xO5, and x preferably satisfies 0?x?0.15.
    Type: Grant
    Filed: January 14, 2011
    Date of Patent: April 14, 2015
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masato Yamazaki, Takayuki Matsuoka, Katsuya Yamagiwa, Kazushige Ohbayashi
  • Publication number: 20140139070
    Abstract: A lead-free piezoelectric ceramic composition mainly includes a first crystal phase (KNN phase) and a second crystal phase (NTK phase). In the first crystal phase (KNN phase), a plurality of crystal grains formed of an alkali niobate/tantalate perovskite oxide having piezoelectric characteristics is bound to each other in a deposited state. The second crystal phase (NTK phase) is formed of a compound containing titanium (Ti) and fills spaces between the crystal grains in the first crystal phase.
    Type: Application
    Filed: July 4, 2012
    Publication date: May 22, 2014
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Masato Yamazaki, Takayuki Matsuoka, Kazuaki Kitamura, Hideto Yamada, Toshiaki Kurahashi, Katsuya Yamagiwa, Kazushige Ohbayashi
  • Patent number: 8502435
    Abstract: There are provided a piezoelectric ceramic composition that includes a bismuth layer-structured compound, which contains Na, Bi, Co and Ln (lanthanoide), as a main component and a piezoelectric ceramic composition that includes a compound, which contains Na, Bi, Ti, Co and Ln (lanthanoide) and has a Na0.5Bi4.5Ti4O15 type crystal structure, as a main component, wherein the piezoelectric ceramic composition has an atomic ratio of 0<Ln/(Na+Bi+Ln)?0.04.
    Type: Grant
    Filed: April 17, 2008
    Date of Patent: August 6, 2013
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masato Yamazaki, Kohei Ito, Katsuya Yamagiwa, Takeshi Mitsuoka
  • Publication number: 20120146462
    Abstract: A lead-free piezoelectric ceramic composition includes a first crystal phase of alkali niobate/tantalate type perovskite oxide having piezoelectric properties and a second crystal phase of A—Ti—B—O composite oxide (where the element A is an alkali metal; the element B is at least one of Nb and Ta; and the contents of the element A, the element B and Ti are not zero). Examples of the second crystal phase are those represented by A1?xTi1?xB1+xO5, and x preferably satisfies 0?x?0.15.
    Type: Application
    Filed: January 14, 2011
    Publication date: June 14, 2012
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Masato Yamazaki, Takayuki Matsuoka, Katsuya Yamagiwa, Kazushige Ohbayashi
  • Patent number: 8142679
    Abstract: The present invention provides a piezoelectric ceramic composition having a high thermal resistance and a high piezoelectric distortion constant and a piezoelectric element using the piezoelectric ceramic composition. The piezoelectric ceramic composition of the present invention contains Na, Bi, Ti, Cr and O, wherein the content ratio of Na, Bi, Ti and Cr in terms of oxides thereof falls within the following composition range: aNa2O-bBi2O3-cTiO2-dCrO3/2 where a, b, c and d are mole fractions; 0.030?a?0.042; 0.330?b?0.370; 0.580?c?0.620; 0<d?0.017; and a+b+c+d=1. The piezoelectric ceramic composition preferably has a main crystal phase of bismuth layer-structured ferroelectric, more preferably Na0.5Bi4.5Ti4O15 crystal. The piezoelectric element of the present invention includes a piezoelectric body formed of the piezoelectric ceramic composition and at least a pair of electrodes held in contact with the piezoelectric body.
    Type: Grant
    Filed: June 22, 2009
    Date of Patent: March 27, 2012
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masato Yamazaki, Takayuki Matsuoka, Katsuya Yamagiwa, Takeshi Mitsuoka
  • Patent number: 8040024
    Abstract: A piezoceramic material according to an embodiment of the present invention has a composition represented by Pbm{Zr1-x-y-zTixSny(Sb1-nNbn)z}O3 where 1.000?m?1.075, 0.470?x<0.490, 0.020?y?0.040, 0<n<1.000 and 0<z?0.025 and a crystallite size of 30 to 39 nm.
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: October 18, 2011
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masato Yamazaki, Hideaki Hiramitsu, Manabu Horiguchi, Yukihiro Hamaguchi, Katsuya Yamagiwa, Takeshi Mitsuoka, Kazushige Ohbayashi, Ryotaro Tawara, Tomohiro Hirata
  • Publication number: 20100264355
    Abstract: The present invention provides a piezoelectric ceramic composition having a high thermal resistance and a high piezoelectric distortion constant and a piezoelectric element using the piezoelectric ceramic composition. The piezoelectric ceramic composition of the present invention contains Na, Bi, Ti, Cr and O, wherein the content ratio of Na, Bi, Ti and Cr in terms of oxides thereof falls within the following composition range: aNa2O-bBi2O3-cTiO2-dCrO where a, b, c and d are mole fractions; 0.030?a?0.042; 0.330?b?0.370; 0.580?c?0.620; 0?d?0.017; and a+b+c+d=1. The piezoelectric ceramic composition preferably has a main crystal phase of bismuth layer-structured ferroelectric, more preferably Na0.5Bi4.5Ti4O15 crystal. The piezoelectric element of the present invention includes a piezoelectric body formed of the piezoelectric ceramic composition and at least a pair of electrodes held in contact with the piezoelectric body.
    Type: Application
    Filed: June 22, 2009
    Publication date: October 21, 2010
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Masato Yamazaki, Takayuki Matsuoka, Katsuya Yamagiwa, Takeshi Mitsuoka
  • Patent number: 7808161
    Abstract: There is provided a piezoelectric ceramic composition that contains Na, Bi, Ti and Co wherein the composition ratio of Na, Bi, Ti and Co in terms of oxides thereof is in the following composition range (1): aNa2O-bBi2O3-cTiO2-dCoO??(1) where a, b, c and d are mole fractions; 0.03?a?0.042; 0.330?b?0.370; 0.580?c?0.620; 0<d?0.017; and a+b+c+d=1.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: October 5, 2010
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masato Yamazaki, Kohei Ito, Yasuhiro Fujii, Katsuya Yamagiwa, Takeshi Mitsuoka
  • Publication number: 20100133959
    Abstract: There are provided a piezoelectric ceramic composition that includes a bismuth layer-structured compound, which contains Na, Bi, Co and Ln (lanthanoide), as a main component and a piezoelectric ceramic composition that includes a compound, which contains Na, Bi, Ti, Co and Ln (lanthanoide) and has a Na0.5Bi4.5Ti4O15 type crystal structure, as a main component, wherein the piezoelectric ceramic composition has an atomic ratio of 0<Ln/(Na+Bi+Ln)?0.04.
    Type: Application
    Filed: April 17, 2008
    Publication date: June 3, 2010
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Masato Yamazaki, Kohei Ito, Katsuya Yamagiwa, Takeshi Mitsuoka
  • Publication number: 20090289525
    Abstract: There is provided a piezoelectric ceramic composition that contains Na, Bi, Ti and Co wherein the composition ratio of Na, Bi, Ti and Co in terms of oxides thereof is in the following composition range (1): aNa2O-bBi2O3-cTiO2-dCoO??(1) where a, b, c and d are mole fractions; 0.03?a?0.042; 0.330?b?0.370; 0.580?c?0.620; 0<d?0.017; and a+b+c+d=1.
    Type: Application
    Filed: March 25, 2008
    Publication date: November 26, 2009
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Masato YAMAZAKI, Kohei ITO, Yasuhiro FUJII, Katsuya YAMAGIWA, Takeshi MITSUOKA
  • Publication number: 20090223282
    Abstract: A piezoceramic material according to an embodiment of the present invention has a composition represented by Pbm{Zr1-x-y-zTixSny(Sb1-nNbn)z}O3 where 1.000?m?1.075, 0.470?x<0.490, 0.020?y?0.040, 0<n<1.000 and 0<z?0.025 and a crystallite size of 30 to 39 nm.
    Type: Application
    Filed: March 4, 2009
    Publication date: September 10, 2009
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Masato YAMAZAKI, Hideaki HIRAMITSU, Manabu HORIGUCHI, Yukihiro HAMAGUCHI, Katsuya YAMAGIWA, Takeshi MITSUOKA, Kazushige OHBAYASHI, Ryotaro TAWARA, Tomohiro HIRATA
  • Publication number: 20070120446
    Abstract: Objects of the present invention are to provide a piezoelectric ceramic composition which contains substantially no lead, which exhibits excellent piezoelectric characteristics, and which has high heat durability; and to provide a piezoelectric element including the composition. The piezoelectric ceramic composition contains M1 (a divalent metallic element, or a metallic element combination formally equivalent to a divalent metallic element); M2 (a tetravalent metallic element, or a metallic element combination formally equivalent to a tetravalent metallic element); and M3 (a metallic element of a sintering aid component), wherein, when these metallic elements constitute the formula [(½)aK2O-(½)bNa2O-cM1O-(½)dNb2O5-eM2O2], a, b, c, d, and e in the formula satisfy the following relations: 0<a<0.5, 0<b<0.5, 0<c<0.11, 0.4<d<0.56, 0<e<0.12, 0.4<a+b+c?0.
    Type: Application
    Filed: May 28, 2004
    Publication date: May 31, 2007
    Applicant: NGK Spark Plug Co., Ltd.
    Inventors: Masato Yamazaki, Kohei Ito, Katsuya Yamagiwa, Yasuyuki Okimura, Kazushige Obayashi, Takeshi Mitsuoka
  • Patent number: 6821930
    Abstract: An aqueous solution of mixed metal acetate including one kind or more of element selected from lanthanide series and yttrium, barium and copper is mixed with trifluoroacetic acid to prepare a solution of mixed metal trifluoroacetate. From a solution of mixed metal trifluoroacetate obtained thus, purified mixed metal trifluoroacetate of which total content of water and acetic acid is 2% by weight or less is prepared. With purified mixed metal trifluoroacetate, an oxide superconductor of excellent performance may be prepared.
    Type: Grant
    Filed: May 20, 2003
    Date of Patent: November 23, 2004
    Assignees: Kabushiki Kaisha Toshiba, International Superconductivity Technology Center
    Inventors: Takeshi Araki, Katsuya Yamagiwa, Izumi Hirabayashi
  • Patent number: 6720280
    Abstract: A dielectric composition is based on a BaO—MgO—Nb2O5 system material (BMN system material) having a dielectric constant, &egr;, of about 30, a large Q-value (no-load quality coefficient) and a comparatively small absolute value of the temperature coefficient (&tgr;f) of its resonance frequency but containing no expensive Ta. The dielectric material has a composite perovskite crystal structure as the main crystal phase, wherein a predetermined amount of KNbO3 is added to a BMN system material. The high frequency characteristics can be further improved by partially replacing Nb with Sb and partially replacing the B site of the perovskite crystal structure with Sn.
    Type: Grant
    Filed: June 14, 2002
    Date of Patent: April 13, 2004
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Katsuya Yamagiwa, Jun Otsuka, Takashi Kasashima, Manabu Sato, Kazuhisa Itakura, Takashi Oba, Masahiko Matsumiya
  • Publication number: 20030198748
    Abstract: An aqueous solution of mixed metal acetate including one kind or more of element selected from lanthanide series and yttrium, barium and copper is mixed with trifluoroacetic acid to prepare a solution of mixed metal trifluoroacetate. From a solution of mixed metal trifluoroacetate obtained thus, purified mixed metal trifluoroacetate of which total content of water and acetic acid is 2% by weight or less is prepared. With purified mixed metal trifluoroacetate, an oxide superconductor of excellent performance may be prepared.
    Type: Application
    Filed: May 20, 2003
    Publication date: October 23, 2003
    Applicants: Kabushiki Kaisha Toshiba, International Superconductivity Technology Center, Spark Plug Co., Ltd.
    Inventors: Takeshi Araki, Katsuya Yamagiwa, Izumi Hirabayashi
  • Publication number: 20030176273
    Abstract: A dielectric composition is based on a BaO—MgO—Nb2O5 system material (BMN system material) having a dielectric constant, &egr;, of about 30, a large Q-value (no-load quality coefficient) and a comparatively small absolute value of the temperature coefficient (&tgr;f) of its resonance frequency but containing no expensive Ta. The dielectric material has a composite perovskite crystal structure as the main crystal phase, wherein a predetermined amount of KNbO3 is added to a BMN system material. The high frequency characteristics can be further improved by partially replacing Nb with Sb and partially replacing the B site of the perovskite crystal structure with Sn.
    Type: Application
    Filed: June 14, 2002
    Publication date: September 18, 2003
    Inventors: Katsuya Yamagiwa, Jun Otsuka, Takashi Kasashima, Manabu Sato, Kazuhisa Itakura, Takashi Oba, Masahiko Matsumiya
  • Patent number: 6586042
    Abstract: An aqueous solution of mixed metal acetate including one kind or more of element selected from lanthanide series and yttrium, barium and copper is mixed with trifluoroacetic acid to prepare a solution of mixed metal trifluoroacetate. From a solution of mixed metal trifluoroacetate obtained thus, purified mixed metal trifluoroacetate of which total content of water and acetic acid is 2% by weight or less is prepared. With purified mixed metal trifluoroacetate, an oxide superconductor of excellent performance may be prepared.
    Type: Grant
    Filed: September 5, 2001
    Date of Patent: July 1, 2003
    Assignees: Kabushiki Kaisha Toshiba, International Superconductivity Technology Center, Spark Plug Co., Ltd.
    Inventors: Takeshi Araki, Katsuya Yamagiwa, Izumi Hirabayashi