公开(公告)号：US20240210342A1

公开(公告)日：2024-06-27

申请号：US18579171

申请日：2022-06-16

Applicant: Nagaoka University of Technology ,  KOA Corporation

Inventor： Tomoichiro Okamoto ,  Kenichi Iguchi ,  Yukiko Ota ,  Ryosuke Komatsu ,  Zoku Ko ,  Tetsuro Tanaka

IPC: G01N27/12

CPC classification number: G01N27/125 ,  G01N27/123

Abstract: In a resistive oxygen gas sensor, an oxygen gas detection member for detecting oxygen gas contains, as a main component, a semiconductor material having a composition formula represented by RE(Ba2-x, REx)Cu3O, (wherein, RE is a rare earth element, x is 0≤x≤ 1.2, and y is 6.0≤y≤7.5).

公开(公告)号：US11977042B2

公开(公告)日：2024-05-07

申请号：US17040332

申请日：2019-03-20

Applicant: KOA CORPORATION

Inventor： Chika Ito ,  Ken Takahashi ,  Tetsuro Tanaka ,  Kenichi Iguchi

IPC: G01N27/12 ,  G01N27/407 ,  G01N27/416 ,  G01N27/419

CPC classification number: G01N27/128 ,  G01N27/12 ,  G01N27/125 ,  G01N27/4071 ,  G01N27/4073 ,  G01N27/4161 ,  G01N27/419 ,  C04B2235/3225 ,  C04B2235/3227

Abstract: An oxygen sensor for detecting gas concentration based on either an electric current value or a resistance value measured when a voltage is applied to a sensor element includes gaps formed between electrodes arranged in an element main body and ridges where surfaces of an element touch each other. These gaps will be escaping parts for expansion and contraction of electrode material that accompany thermal expansion and contraction of a sensor main body, and concentration of thermal stress at edge parts of the element main body may thus be eliminated, thereby alleviating thermal stress on the oxygen sensor. This allows provision of a gas sensor that controls generation of cracks in the element and that is stably usable over a long period of time.

公开(公告)号：US11370671B2

公开(公告)日：2022-06-28

申请号：US15734863

申请日：2019-06-04

Applicant: KOA CORPORATION ,  JFE MINERAL COMPANY, LTD.

Inventor： Naomi Ishida ,  Yoji Gomi ,  Kenichi Iguchi ,  Etsurou Udagawa ,  Yuko Echizenya ,  Yoshimi Nakata

IPC: H01B1/08 ,  C01G9/02 ,  H01C7/12 ,  C01G9/00 ,  H01C7/112 ,  B82Y40/00

Abstract: Focusing on zinc oxide itself, which is a main raw material for a zinc oxide varistor (laminated varistor), a predetermined amount of additive is added to a zinc oxide powder having crystallite size of 20 to 100 nm, particle diameter of 20 to 110 nm found using a specific area BET method, untamped density of 0.60 g/cm3 or greater, and tap density of 0.80 g/cm3 or greater. This allows a zinc oxide sintered body to secure uniformity, high density, and high electric conductivity, resulting in a zinc oxide varistor with high surge resistance, capable of downsizing and cost reduction. Moreover, addition of aluminum (Al), as a donor element, to the zinc oxide powder allows control of sintered grain size in conformity with the aluminum added amount and baking temperature, and also allows adjustment of varistor voltage, etc.

公开(公告)号：US11370712B2

公开(公告)日：2022-06-28

申请号：US16467624

申请日：2017-12-07

Applicant: KOA CORPORATION ,  JFE MINERAL COMPANY, LTD.

Inventor： Yoji Gomi ,  Kenichi Iguchi ,  Etsurou Udagawa ,  Yuko Echizenya ,  Yoshimi Nakata

IPC: H01B1/08 ,  C04B35/453 ,  C01G9/02 ,  H01C7/12

Abstract: Focus is on zinc oxide itself, which is a base material for a zinc oxide varistor (laminated varistor), wherein specified quantities of additives are added to a zinc oxide powder having a crystallite size of 20 to 50 nm, grain diameter of 15 to 60 nm found using the specific surface area BET method, untamped density of 0.38 to 0.50 g/cm3, and tap density of 0.50 to 1.00 g/cm3. This allows securing of uniformity, high compactness, and high electrical conductivity of a zinc oxide sintered body, and provision of a zinc oxide varistor having high surge resistance.