Zinc oxide element

Patent metadata

Field	Value
Publication number	US-12415760-B2
Application number	US-202318848084-A
Country	US
Kind code	B2
Filing date	Mar 8, 2023
Priority date	Mar 18, 2022
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

Provided is a zinc oxide element which does not contain antimony oxide and has good nonlinear resistance characteristics (V10 kA/V1 mA nonlinearity) by controlling the particle size of zinc oxide particles in a sintered body. The zinc oxide element of the present invention includes a fired body containing zinc oxide, bismuth oxide, and zinc stannate (Zn 2 SO 4 ). A method for producing a zinc oxide element of the present invention includes firing a raw material oxide that contains zinc oxide, bismuth oxide, and tin oxide and does not contain antimony oxide, and segregating zinc stannate (Zn 2 SO 4 ) at grain boundaries of the fired zinc oxide.

First claim

The invention claimed is:

1. A zinc oxide element comprising a fired body containing 90 to 99.4 mol % zinc oxide, 0.3 to 1 mol % bismuth oxide, and 0.1 to 5 mol % zinc stannate (Zn 2 SnO 4 ), and
in an arbitrary cross section of the fired body, a value obtained by dividing a standard deviation (σ) based on a distribution of cross-sectional areas of zinc oxide particles by an average particle diameter (D) of the zinc oxide particles (σ/D) is 0.4 or less, wherein the total amount of metal elements in the fired body is 100 mol %.

2. The zinc oxide element according to claim 1 , wherein the fired body further contains 0.1 to 5 mol % tin oxide.

3. The zinc oxide element according to claim 1 , wherein the fired body does not contain antimony oxide.

4. The zinc oxide element according to claim 1 , wherein the fired body further contains at least one oxide compound selected from the group consisting of cobalt oxide (III), nickel oxide (II), manganese oxide (II), chromium oxide (III), silver oxide, silicon oxide, and boron oxide and wherein the at least one oxide compound is present in an amount of 0.01 to 7.0 mol %.

5. The zinc oxide element according to claim 1 , wherein the fired body further contains an oxide of at least one rare earth element selected from the group consisting of yttrium, europium, erbium, thulium, gadolinium, dysprosium, holmium, and ytterbium and wherein the oxide of at least one rare earth element is present in an amount of 0.01 to 5 mol %.

6. A method for producing a zinc oxide element, comprising firing a raw material oxide that contains 90 to 99.4 mol % zinc oxide, 0.3 to 1 mol % bismuth oxide, and 0.1 to 5 mol % tin oxide and does not contain antimony oxide, and segregating zinc stannate (Zn 2 SnO 4 ) at grain boundaries of the fired zinc oxide during the firing, wherein the total amount of metal elements in the fired body is 100 mol % and wherein the firing is at a maximum holding temperature of 1000 to 1200° C., a holding time of 1 to 15 hours, a temperature raising rate of 10 to 70° C./hour, and a temperature lowering rate of 10 to 70° C./hour.

7. The production method according to claim 6 , wherein the raw material oxide further contains at least one oxide compound selected from the group consisting of cobalt oxide (III), nickel oxide (II), manganese oxide (II), chromium oxide (III), silver oxide, silicon oxide, and boron oxide and wherein the at least one oxide compound is present in an amount of 0.01 to 7.0 mol %.

8. The production method according to claim 6 , wherein the raw material oxide further contains an oxide of at least one rare earth element selected from the group consisting of yttrium, europium, erbium, thulium, gadolinium, dysprosium, holmium, and ytterbium and wherein the oxide of at least one rare earth element is present in an amount of 0.01 to 5 mol %.

Assignees

• Meidensha Electric Mfg Co Ltd

Inventors

• Komatsu Yuya
• Seki Atsushi
• Takada Masayuki
• Tagami Yukio

Classifications

• B32B18/00

  Layered products essentially comprising ceramics, e.g. refractory products · CPC title

• H01C7/12

  Overvoltage protection resistors; Arresters · CPC title

• H01C7/112

  ZnO type · CPC title

• C04B2235/85

  Intergranular or grain boundary phases · CPC title

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title