JPH0142610B2 - - Google Patents
Info
- Publication number
- JPH0142610B2 JPH0142610B2 JP58158274A JP15827483A JPH0142610B2 JP H0142610 B2 JPH0142610 B2 JP H0142610B2 JP 58158274 A JP58158274 A JP 58158274A JP 15827483 A JP15827483 A JP 15827483A JP H0142610 B2 JPH0142610 B2 JP H0142610B2
- Authority
- JP
- Japan
- Prior art keywords
- zinc oxide
- particles
- mol
- bismuth oxide
- added
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 claims description 176
- 239000011787 zinc oxide Substances 0.000 claims description 86
- 229910000416 bismuth oxide Inorganic materials 0.000 claims description 75
- TYIXMATWDRGMPF-UHFFFAOYSA-N dibismuth;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Bi+3].[Bi+3] TYIXMATWDRGMPF-UHFFFAOYSA-N 0.000 claims description 75
- 239000002245 particle Substances 0.000 claims description 73
- 239000000203 mixture Substances 0.000 claims description 32
- 238000005245 sintering Methods 0.000 claims description 13
- 238000002156 mixing Methods 0.000 claims description 8
- 239000000843 powder Substances 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 239000007921 spray Substances 0.000 claims description 4
- 238000005469 granulation Methods 0.000 claims 1
- 230000003179 granulation Effects 0.000 claims 1
- 238000007493 shaping process Methods 0.000 claims 1
- 239000013078 crystal Substances 0.000 description 25
- 230000000630 rising effect Effects 0.000 description 13
- 238000010586 diagram Methods 0.000 description 11
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 description 7
- 230000007423 decrease Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000001354 calcination Methods 0.000 description 5
- 238000000465 moulding Methods 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 3
- 239000012798 spherical particle Substances 0.000 description 3
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- -1 bismuth Chemical class 0.000 description 2
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N CuO Inorganic materials [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- GEIAQOFPUVMAGM-UHFFFAOYSA-N ZrO Inorganic materials [Zr]=O GEIAQOFPUVMAGM-UHFFFAOYSA-N 0.000 description 1
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Inorganic materials O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 description 1
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Inorganic materials [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(II) oxide Inorganic materials [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- YEXPOXQUZXUXJW-UHFFFAOYSA-N lead(II) oxide Inorganic materials [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- VASIZKWUTCETSD-UHFFFAOYSA-N manganese(II) oxide Inorganic materials [Mn]=O VASIZKWUTCETSD-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910000108 silver(I,III) oxide Inorganic materials 0.000 description 1
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Inorganic materials [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 description 1
- YEAUATLBSVJFOY-UHFFFAOYSA-N tetraantimony hexaoxide Chemical compound O1[Sb](O2)O[Sb]3O[Sb]1O[Sb]2O3 YEAUATLBSVJFOY-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Thermistors And Varistors (AREA)
Description
【発明の詳細な説明】
本発明は酸化亜鉛を主成分とした低電圧用のバ
リスタの製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a low voltage varistor containing zinc oxide as a main component.
従来酸化亜鉛を主成分としこれをBi2O3、
MgO、Cr2O3、Fe2O3、Sb2O3、CoO、MnO、
NiOなどの電圧敏感性酸化物および電導性酸化物
を加えた組成を成形焼結してなる酸化亜鉛系バリ
スタはそのすぐれた非直線性のために広く用いら
れている。これらの酸化亜鉛系バリスタでは焼結
体厚さ１mmにおける立上り電圧をV1ｍＡ／mmと
し種々の立上り電圧のものが製造されているが、
この立上り電圧は焼結体中の酸化亜鉛を主成分と
する結晶粒の大きさによつて決まる。すなわち低
い立上り電圧を得るためには結晶粒を大きく成長
させることが必要であり、逆に高い立上り電圧を
得るためには結晶粒の成長を抑え、小さな結晶粒
から構成することが必要である。前記酸化亜鉛を
主成分としBi2O3、MgO、Cr2O3、Fe2O3、
Sb2O3、CoO、MnO、NiOなどを加えてなる酸化
亜鉛系バリスタでは結晶粒の大きさが15μｍ程度
であり、立上り電圧は組成により約80〜300Vで
ある。また前記組成からSb2O3を除いたものは結
晶粒の大きさが50μｍ程度、立上り電圧は20〜
40V程度となることも知られている。近年とくに
酸化亜鉛系バリスタの低電圧化の要求が強まり前
記結晶粒の大きなものを含む酸化亜鉛系バリスタ
を得ることが重要な課題となつてきた。この大き
な結晶粒を得る手段としてたとえば特公昭56−
11203号公報に提案された技術がある。これは酸
化亜鉛99.9〜99.5モル％とBaOまたはSrO0.1〜0.5
モル％を混合したのち仮焼し加水熱分解を行つて
70μｍ程度の結晶粒を得、該結晶粒を酸化亜鉛を
主成分とする粉末に0.1〜60重量％添加混合した
のち焼結してなるものである。しかしながらこの
ように加水熱分解によつて結晶粒を得るには前記
酸化亜鉛にBaOまたはSrOを調合しバインダを加
えて成形し、1300℃程度の高温で仮焼し粉砕した
のち加水熱分解しなければならず、工程数が非常
に多くなる欠点がある。また成形後の仮焼温度を
高くしないと大きな結晶粒が得られず、たとえば
結晶粒の大きさ70μｍのものを得るには1300℃程
度の高い仮焼温度を要し、温度管理ならびにこれ
にともなう焼結炉の材料の選択などの技術的、価
格的問題点もあつた。また特性的にもこの結晶粒
を得るための仮焼温度が高いと結晶粒自体の成長
が進んでしまうため活性度が小さくなり、かつこ
の結晶粒を酸化亜鉛を主成分とするものに加え混
合焼結して焼結体を得るときの焼結温度と前記仮
焼温度とが近くなるので結晶粒の成長は限界近く
なり、したがつて焼結体を得るときの焼結過程に
おいて結晶粒がほとんど成長せず焼結後も前記加
水熱分解により得た結晶粒とあまり変わらない大
きさのものしか得られないという欠点を有してい
た。 Conventionally, zinc oxide is the main component, and this is converted into Bi 2 O 3 ,
MgO, Cr2O3 , Fe2O3 , Sb2O3 , CoO , MnO ,
Zinc oxide-based varistors, which are formed by molding and sintering a composition containing voltage-sensitive oxides such as NiO and conductive oxides, are widely used because of their excellent nonlinearity. These zinc oxide-based varistors have a rising voltage of V1mA/mm when the thickness of the sintered body is 1 mm, and various types of rising voltage are manufactured.
This rising voltage is determined by the size of crystal grains whose main component is zinc oxide in the sintered body. That is, in order to obtain a low rising voltage, it is necessary to grow large crystal grains, and conversely, in order to obtain a high rising voltage, it is necessary to suppress the growth of crystal grains and to construct the crystal grains from small crystal grains. The above-mentioned zinc oxide is the main component, and Bi 2 O 3 , MgO, Cr 2 O 3 , Fe 2 O 3 ,
In zinc oxide-based varistors made by adding Sb 2 O 3 , CoO, MnO, NiO, etc., the crystal grain size is about 15 μm, and the rise voltage is about 80 to 300 V depending on the composition. In addition, when Sb 2 O 3 is removed from the above composition, the crystal grain size is about 50 μm, and the rise voltage is 20 ~
It is also known that the voltage is around 40V. In recent years, there has been a particularly strong demand for lower voltages for zinc oxide-based varistors, and it has become an important issue to obtain zinc oxide-based varistors containing large crystal grains. As a means of obtaining such large crystal grains, for example,
There is a technique proposed in Publication No. 11203. This is zinc oxide 99.9-99.5 mol% and BaO or SrO 0.1-0.5
After mixing the mol%, calcining and hydrothermal decomposition are performed.
Crystal grains of approximately 70 μm are obtained, and the crystal grains are added and mixed in a powder containing zinc oxide in an amount of 0.1 to 60% by weight, and then sintered. However, in order to obtain crystal grains through hydrothermal decomposition, it is necessary to mix BaO or SrO with the zinc oxide, add a binder, shape it, calcinate it at a high temperature of about 1300°C, crush it, and then hydropyrolyze it. However, there is a drawback that the number of steps is extremely large. In addition, large crystal grains cannot be obtained unless the calcination temperature after molding is high; for example, to obtain crystal grains with a size of 70 μm, a high calcination temperature of about 1300°C is required, and temperature control and accompanying There were also technical and cost issues such as the selection of materials for the sintering furnace. Also, in terms of characteristics, if the calcination temperature to obtain these crystal grains is high, the growth of the crystal grains themselves will progress, resulting in a decrease in activity. Since the sintering temperature when sintering to obtain a sintered body and the above-mentioned calcination temperature are close to each other, the growth of crystal grains is close to its limit, and therefore, the crystal grains are It has the disadvantage that it hardly grows, and even after sintering, only crystal grains with a size not much different from those obtained by the hydrothermal decomposition can be obtained.
本発明の上記の点に鑑みてなされたもので、酸
化亜鉛と酸化ビスマスとを造粒して得た粒子を、
酸化亜鉛を主成分としこれに少なくとも酸化ビス
マスを加えた粉粒中に添加混合して焼結すること
により前記粒子を焼結体内部に分散して位置さ
せ、これを核として結晶粒の成長を図るもので、
これによつて焼結体内部に大きな結晶粒を配しバ
リスタの低電圧化を図ることを目的としたもので
ある。以下本発明の詳細を実施例によつて説明す
る。 This invention was made in view of the above points of the present invention, and particles obtained by granulating zinc oxide and bismuth oxide,
By adding and mixing zinc oxide into powder grains with at least bismuth oxide added thereto and sintering the particles, the particles are dispersed and located inside the sintered body, and crystal grains are grown using these as nuclei. It is intended to
The purpose of this is to arrange large crystal grains inside the sintered body and lower the voltage of the varistor. The details of the present invention will be explained below with reference to Examples.
実施例 １
酸化亜鉛粉末に酸化ビスマス粉末をそれぞれ
0.003モル％、0.01モル％、0.03モル％、0.1モル
％、0.3モル％、1.0モル％、3.0モル％添加混合し
て７種の酸化亜鉛＋酸化ビスマスの混合粉末を
得、これにバインダと水を加えて混合する。これ
をスプレードライヤに入れて造粒すると前記混合
粉末に加えた水が蒸発した球状粒子を得ることが
できる。この球状粒子はその粒径が約３〜200μ
ｍの大きさを有するが、60〜120μｍの粒子がも
つとも多く20μｍ程度の粒子は非常に少ない。前
記酸化亜鉛＋酸化ビスマスによる７種の粒子を篩
で選別して平均粒径100μｍの酸化亜鉛＋酸化ビ
スマスの粒子を得、これを酸化亜鉛94.5モル％＋
MgO3モル％＋Bi2O30.5モル％＋CoO1.0モル％＋
MnO0.5モル％＋NiO0.5モル％からなる主組成に
対しそれぞれ0.1重量％、0.3重量％、10重量％、
30重量％、60重量％添加混合し、これを成形した
のち1100〜1400℃の温度で１〜８時間焼結した焼
結体の立上り電圧を酸化亜鉛への酸化ビスマスの
添加量との関連について表わしたのが第１図であ
り同じく非直線係数αを表わしたのが第２図であ
る。いずれも曲線Ａは主組成に対する酸化亜鉛＋
酸化ビスマス粒子の添加量が0.1重量％の場合、
同じく曲線Ｂは0.3重量％、曲線Ｃは10重量％、
曲線Ｄは30重量％、曲整Ｅは60重量％の場合であ
る。また第３図には平均粒径100μｍの酸化亜鉛
＋酸化ビスマス粒子を用い、前記主組成に対する
この粒子の添加量と立上り電圧との関係を示す曲
線図、第４図はこの粒子の添加量と非直線係数と
の関係を示す曲線図であるが、いずれも曲線Ｆは
酸化亜鉛＋酸化ビスマス粒子の酸化亜鉛に対する
酸化ビスマスの添加量が0.003モル％の場合、曲
線Ｇは0.01モル％、曲線Ｈは0.1モル％、曲線Ｉ
は1.0モル％、曲線Ｊは3.0モル％の場合を示した
ものである。さらに第５図には酸化亜鉛に対し酸
化ビスマスを0.1モル％添加した酸化亜鉛＋酸化
ビスマス粒子を前記主組成に対し10重量％添加し
たときの酸化亜鉛＋酸化ビスマス粒子の大きさと
立上り電圧との関係を示す曲線図であり、第６図
は粒子の大きさと非直線係数との関係を示す曲線
図である。この結果から明らかなように第１図の
立上り電圧では酸化亜鉛に添加する酸化ビスマス
の量は曲線Ａを除き0.01モル％以上が良好である
が、第２図の非直線係数では曲線Ｅを除き酸化ビ
スマス添加量1.0モル％までは良好でありこれを
越えると急激に低下するという結果を示してい
る。この第１図および第２図の結果から酸化亜鉛
に添加する酸化ビスマスの量は0.01〜1.0モル％
が良好であり、かつこの酸化亜鉛＋酸化ビスマス
粒子を主組成に添加する量は0.3〜30重量％が良
好である。そして第３図および第４図でも酸化亜
鉛＋酸化ビスマス粒子中の酸化ビスマス添加量に
よる特性への影響は曲線Ｆが第３図の立上り電圧
特性が劣つており、また第４図の曲線Ｊが非直線
係数が劣つていることを示している。そして第３
図では主組成に対する酸化亜鉛＋酸化ビスマス粒
子の添加量では0.3重量％から顕著な効果を示し、
第４図では30重量％までは良好だがこれを越える
と急激に劣化することを示している。したがつて
主組成に対する酸化亜鉛＋酸化ビスマス粒子の添
加量は0.3〜30重量％が良好であり、かつ前述の
ように曲線ＦおよびＪを除外した曲線Ｇ，Ｈ，Ｉ
が良好な結果を示していることから酸化亜鉛に対
する酸化ビスマスの添加量は0.01〜1.0モル％で
ある。したがつてこの範囲は第１図および第２図
と全く同一な結果を示している。Example 1 Adding bismuth oxide powder to zinc oxide powder
0.003 mol%, 0.01 mol%, 0.03 mol%, 0.1 mol%, 0.3 mol%, 1.0 mol%, and 3.0 mol% were added and mixed to obtain a mixed powder of seven types of zinc oxide + bismuth oxide, to which a binder and water were added. Add and mix. When this is placed in a spray dryer and granulated, spherical particles in which the water added to the mixed powder has evaporated can be obtained. These spherical particles have a particle size of approximately 3 to 200μ.
It has a size of m, but there are many particles with a size of 60 to 120 μm, and there are very few particles with a size of about 20 μm. The seven types of particles of zinc oxide + bismuth oxide were sorted with a sieve to obtain particles of zinc oxide + bismuth oxide with an average particle size of 100 μm, which were mixed with 94.5 mol% zinc oxide +
MgO3 mol% + Bi 2 O 3 0.5 mol% + CoO1.0 mol% +
0.1% by weight, 0.3% by weight, 10% by weight, respectively, for the main composition consisting of 0.5 mol% MnO + 0.5 mol% NiO,
Regarding the relationship between the rise voltage of a sintered body obtained by adding 30% by weight and 60% by weight, molding it, and sintering it at a temperature of 1100 to 1400°C for 1 to 8 hours, with the amount of bismuth oxide added to zinc oxide. FIG. 1 shows this, and FIG. 2 also shows the nonlinear coefficient α. In both cases, curve A is zinc oxide +
When the amount of bismuth oxide particles added is 0.1% by weight,
Similarly, curve B is 0.3% by weight, curve C is 10% by weight,
Curve D is for 30% by weight and curve E is for 60% by weight. Furthermore, Figure 3 is a curve diagram showing the relationship between the amount of these particles added to the main composition and the rise voltage using zinc oxide + bismuth oxide particles with an average particle size of 100 μm, and Figure 4 is a curve diagram showing the relationship between the amount of these particles added and the rise voltage. These are curve diagrams showing the relationship with the non-linear coefficient, in which curve F is 0.003 mol% of bismuth oxide added to zinc oxide in zinc oxide + bismuth oxide particles, curve G is 0.01 mol%, and curve H is 0.01 mol%. is 0.1 mol%, curve I
shows the case of 1.0 mol%, and curve J shows the case of 3.0 mol%. Furthermore, FIG. 5 shows the size and rise voltage of zinc oxide + bismuth oxide particles when 10% by weight of zinc oxide + bismuth oxide particles with 0.1 mol% of bismuth oxide added to the main composition. FIG. 6 is a curve diagram showing the relationship between particle size and nonlinear coefficient. As is clear from this result, for the rising voltage in Figure 1, the amount of bismuth oxide added to zinc oxide is good at 0.01 mol% or more, except for curve A, but for the nonlinear coefficient in Figure 2, except for curve E. The results show that the addition amount of bismuth oxide is good up to 1.0 mol %, but that it rapidly decreases when this amount is exceeded. From the results shown in Figures 1 and 2, the amount of bismuth oxide added to zinc oxide is 0.01 to 1.0 mol%.
is good, and the amount of zinc oxide + bismuth oxide particles added to the main composition is preferably 0.3 to 30% by weight. Also in Figures 3 and 4, the effect of the amount of bismuth oxide added in the zinc oxide + bismuth oxide particles on the characteristics is that curve F has inferior rise voltage characteristics in Figure 3, and curve J in Figure 4 has poorer rise voltage characteristics. This shows that the nonlinear coefficient is inferior. and the third
The figure shows that the amount of zinc oxide + bismuth oxide particles added to the main composition shows a remarkable effect from 0.3% by weight.
Figure 4 shows that up to 30% by weight it is good, but beyond this it rapidly deteriorates. Therefore, the addition amount of zinc oxide + bismuth oxide particles to the main composition is preferably 0.3 to 30% by weight, and as mentioned above, curves G, H, and I excluding curves F and J
has shown good results, the amount of bismuth oxide added to zinc oxide is 0.01 to 1.0 mol%. Therefore, this range shows exactly the same results as in FIGS. 1 and 2.
さらに酸化亜鉛＋酸化ビスマスの粒子径と立上
り電圧および非直線係数との関係を第５図および
第６図に示す。なお試料は酸化亜鉛に添加する酸
化ビスマス量を0.1モル％とし上記実施例と同じ
組成からなる主組成に対し酸化亜鉛＋酸化ビスマ
スを10重量％添加混合した粒子を用いたものであ
る。第５図および第６図において従来とあるのは
主組成に直接実施例と同じ量の酸化亜鉛と酸化ビ
スマス粉末を添加し、これらを混合して1100〜
1400℃の温度で１〜８時間いつしよに焼結した場
合を示し酸化亜鉛＋酸化ビスマスの造粒工程を省
いたものである。これよればスプレードライヤで
造粒した酸化亜鉛＋酸化ビスマス粒子の平均粒径
が10μｍでは非直線係数が従来と変化なく、かつ
立上り電圧V1ｍＡ／mmが従来の39Vから31Vに低
下し非常に低電圧のバリスタを得られることは明
白であり、平均粒径が大となるにしたがつて立上
り電圧は急激な低下を示す。しかし非直線係数は
従来30に対し平均粒径100μｍを越えると急激に
低下しはじめ、200μｍでは20を示しこの値は十
分使用できる値であるが、300μｍではさらに低
下して12となり使用できない数値となる。以上の
ことから酸化亜鉛＋酸化ビスマスを造粒したとき
の粒径は10〜200μｍが適当な範囲と定めること
ができる。 Furthermore, the relationship between the particle diameter of zinc oxide + bismuth oxide, the rising voltage, and the nonlinear coefficient is shown in FIGS. 5 and 6. The sample used particles in which the amount of bismuth oxide added to zinc oxide was 0.1 mol%, and 10% by weight of zinc oxide + bismuth oxide was added and mixed to the main composition, which was the same as that of the above example. In Fig. 5 and Fig. 6, the conventional method is to directly add the same amount of zinc oxide and bismuth oxide powder as in the example to the main composition, and to mix these together.
This shows the case of continuous sintering at a temperature of 1400°C for 1 to 8 hours, and the step of granulating zinc oxide + bismuth oxide is omitted. According to this, when the average particle size of zinc oxide + bismuth oxide particles granulated with a spray dryer is 10 μm, the nonlinear coefficient remains unchanged from the conventional one, and the rising voltage V1mA/mm decreases from the conventional 39V to 31V, resulting in an extremely low voltage. It is clear that a varistor of 100% can be obtained, and the rise voltage shows a rapid decrease as the average grain size increases. However, the nonlinear coefficient starts to decrease rapidly when the average particle size exceeds 100 μm, compared to the conventional 30. At 200 μm, it reaches 20, which is a sufficiently usable value, but at 300 μm, it decreases further to 12, which is an unusable value. Become. From the above, it can be determined that the appropriate particle size for granulating zinc oxide + bismuth oxide is 10 to 200 μm.
この結果から酸化亜鉛粉末に対し0.01〜1.0モ
ル％の酸化ビスマスを添加して造粒し平均粒径10
〜200μｍの酸化亜鉛＋酸化ビスマス粒子を得、
これを酸化亜鉛＋MgO＋Bi2O3＋CoO＋MnO＋
NiOからなる主組成に対し0.3〜30重量％添加し
て混合粒子とし、ともに焼結することによつて立
上り電圧や非直線係数などの特性の優れた低電圧
用バリスタを得ることができる。 Based on this result, 0.01 to 1.0 mol% of bismuth oxide was added to the zinc oxide powder and granulated with an average particle size of 10.
~200 μm zinc oxide + bismuth oxide particles were obtained,
This is zinc oxide + MgO + Bi 2 O 3 + CoO + MnO +
By adding 0.3 to 30% by weight of NiO to the main composition to form mixed particles and sintering them together, a low voltage varistor with excellent characteristics such as rise voltage and nonlinear coefficient can be obtained.
実施例 ２
前記実施例１では主組成として酸化亜鉛＋
MgO＋Bi2O3＋CoO＋MnO＋NiOからなるもの
を使用した場合について述べたが、この実施例２
ではこれにSb2O3およびCr2O3を加えて主組成と
した場合について述べる。Sb2O3やCr2O3は酸化
亜鉛の結晶粒成長を助長させるビスマスなどの低
融点金属やこれらの酸化物の中へ早期に拡散する
ので酸化亜鉛の粒成長を阻害する性質を有してい
る。したがつてSb2O3やCr2O3を含む酸化亜鉛を
主成分とするバリスタでは酸化亜鉛の結晶粒成長
が望めず結晶が小さくなるので比較的高電圧用に
用いられ低電圧用には不適とされているものであ
る。まず酸化亜鉛粉末に酸化ビスマス粉末をそれ
ぞれ0.003モル％、0.01モル％、0.03モル％、0.1
モル％、0.3モル％、3.0モル％添加混合してスプ
レードライヤで造粒し７種の酸化亜鉛＋酸化ビス
マス粒子を得、以下実施例１と同様にして平均粒
径100μｍの酸化亜鉛＋酸化ビスマスの球状粒子
を得た。この粒子を酸化亜鉛94モル％＋MgO3モ
ル％＋Bi2O30.5モル％＋CoO1.0モル％＋MnO0.5
モル％＋NiO0.5モル％＋Sb2O30.3モル％＋
Cr2O30.2モル％からなる主組成に対し、0.1重量
％、0.3重量％、10重量％、30重量％、60重量％
をそれぞれ添加混合してこれを成形したのち1100
〜1400℃の温度で１〜８時間焼結したときの立上
り電圧を酸化亜鉛への酸化ビスマスの添加量との
関連において第７図、同じく非直線係数を第８図
に示した。いずれも曲線Ｋは主組成に対する酸化
亜鉛＋酸化ビスマス粒子の添加量が0.1重量％の
場合、曲線Ｌは0.3重量％、曲線Ｍは10重量％、
曲線Ｎは30重量％、曲線Ｏは60重量％の場合を示
す。また第９図には平均粒径100μｍの酸化亜鉛
＋酸化ビスマス粒子を用い前記主組成に対するこ
の粒子の添加量と立上り電圧との関係を示す曲線
図を、そして第１０図にはこの粒子の添加量と非
直線係数との関係を示す曲線図を示した。なお曲
線Ｐは酸化亜鉛＋酸化ビスマス粒子の酸化亜鉛に
対する酸化ビスマスの添加量0.003モル％の場合、
曲線Ｑは0.01モル％、曲線Ｒは0.1モル％、曲線
Ｓは1.0モル％、曲線Ｔは3.0モル％の場合を示し
たものである。そして第１１図には酸化亜鉛に対
し酸化ビスマスを0.1モル％添加した酸化亜鉛＋
酸化ビスマス粒子を主組成に対し10重量％添加し
たときの酸化亜鉛＋酸化ビスマス粒子の大きさと
立上り電圧との関係を示す曲線図であり、第１２
図は粒子の大きさと非直線係数との関係を示す曲
線図である。なおそれぞれの焼結は1100〜1400℃
の温度で１〜８時間行つた。Example 2 In Example 1, the main composition was zinc oxide +
Although we have described the case where MgO + Bi 2 O 3 + CoO + MnO + NiO is used, this Example 2
Now, we will discuss the case where Sb 2 O 3 and Cr 2 O 3 are added to this as the main composition. Sb 2 O 3 and Cr 2 O 3 have the property of inhibiting the grain growth of zinc oxide because they quickly diffuse into low melting point metals such as bismuth, which promote grain growth of zinc oxide, and these oxides. ing. Therefore, in varistors whose main component is zinc oxide containing Sb 2 O 3 or Cr 2 O 3 , crystal grain growth of zinc oxide cannot be expected and the crystals become small, so they are used for relatively high voltage applications and are not used for low voltage applications. It is considered inappropriate. First, add bismuth oxide powder to zinc oxide powder at 0.003 mol%, 0.01 mol%, 0.03 mol%, and 0.1 mol%, respectively.
mol%, 0.3 mol%, and 3.0 mol% were added and mixed and granulated using a spray dryer to obtain seven types of zinc oxide + bismuth oxide particles. spherical particles were obtained. These particles are composed of 94 mol% zinc oxide + 3 mol% MgO + 0.5 mol% Bi 2 O 3 + 1.0 mol% CoO + 0.5 mol% MnO.
Mol% + NiO 0.5 mol% + Sb 2 O 3 0.3 mol% +
0.1% by weight, 0.3% by weight, 10% by weight, 30% by weight, 60% by weight relative to the main composition consisting of 0.2% by mole of Cr 2 O 3
After adding and mixing each and molding this, 1100
The rise voltage when sintered at a temperature of ~1400°C for 1 to 8 hours is shown in Figure 7 in relation to the amount of bismuth oxide added to zinc oxide, and the nonlinear coefficient is shown in Figure 8. In each case, curve K is 0.1% by weight of zinc oxide + bismuth oxide particles relative to the main composition, curve L is 0.3% by weight, curve M is 10% by weight,
Curve N shows the case of 30% by weight, and curve O shows the case of 60% by weight. In addition, Fig. 9 shows a curve diagram showing the relationship between the amount of these particles added to the main composition and the rise voltage using zinc oxide + bismuth oxide particles with an average particle size of 100 μm, and Fig. 10 shows the relationship between the amount of these particles added to the main composition and the rise voltage. A curve diagram showing the relationship between the amount and the nonlinear coefficient is shown. In addition, curve P is when the amount of bismuth oxide added to zinc oxide in zinc oxide + bismuth oxide particles is 0.003 mol%,
Curve Q shows the case of 0.01 mol%, curve R shows the case of 0.1 mol%, curve S shows the case of 1.0 mol%, and curve T shows the case of 3.0 mol%. Figure 11 shows zinc oxide + 0.1 mol% of bismuth oxide added to zinc oxide.
12 is a curve diagram showing the relationship between the size of zinc oxide + bismuth oxide particles and the rise voltage when 10% by weight of bismuth oxide particles are added to the main composition;
The figure is a curve diagram showing the relationship between particle size and nonlinear coefficient. Each sintering temperature is 1100~1400℃
The temperature was 1 to 8 hours.
これらの結果から明らかなように第７図および
第８図に示した立上り電圧と非直線係数は実施例
１の第１図・第２図より顕著ではないが、曲線Ｋ
およびＯを除き酸化亜鉛に添加する酸化ビスマス
の混合量が0.01〜1.0モル％の範囲で良好である。
したがつて第７図および第８図の結果から酸化亜
鉛に添加する酸化ビスマスの量は0.01〜1.0モル
％で、かつこの酸化亜鉛＋酸化ビスマス粒子を主
組成に添加する量は0.3〜30重量％の範囲が良好
である。この範囲が特性上良好な結果を示すこと
は第９図および第１０図からも確認できる。そし
て実施例１と同様、酸化亜鉛＋酸化ビスマス粒子
の大きさと立上り電圧および非直線係数との関係
を第１１図および第１２図に示す。試料は酸化亜
鉛に添加する酸化ビスマス量を0.1モル％とし主
組成に対し酸化亜鉛＋酸化ビスマス粒子を10重量
％添加したものを用いた。図において従来とある
のは主組成に直接該実施例と同じ量の酸化亜鉛と
酸化ビスマス粉末を添加混合して焼結した場合を
示したものである。この結果立上り電圧および非
直線係数とも絶対値は大きいものの実施例１と同
様の特性傾向を示しており、酸化亜鉛＋酸化ビス
マス粒子の平均粒径が10〜200μｍが適当な範囲
とすることができる。 As is clear from these results, the rising voltage and nonlinear coefficient shown in FIGS. 7 and 8 are not as remarkable as those in FIGS. 1 and 2 of Example 1, but the curve K
The mixing amount of bismuth oxide added to zinc oxide excluding O and O is preferably in the range of 0.01 to 1.0 mol%.
Therefore, from the results shown in Figures 7 and 8, the amount of bismuth oxide added to zinc oxide is 0.01 to 1.0 mol%, and the amount of zinc oxide + bismuth oxide particles added to the main composition is 0.3 to 30% by weight. % range is good. It can be confirmed from FIGS. 9 and 10 that this range shows good results in terms of characteristics. As in Example 1, the relationship between the size of the zinc oxide+bismuth oxide particles, the rising voltage, and the nonlinear coefficient is shown in FIGS. 11 and 12. The sample used was one in which the amount of bismuth oxide added to zinc oxide was 0.1 mol%, and 10% by weight of zinc oxide + bismuth oxide particles were added to the main composition. In the figure, "conventional" indicates the case where zinc oxide and bismuth oxide powder were added and mixed directly to the main composition in the same amounts as in the embodiment and sintered. As a result, although the absolute values of both the rise voltage and the nonlinear coefficient are large, they show the same characteristic tendency as in Example 1, and the average particle size of the zinc oxide + bismuth oxide particles can be set in an appropriate range of 10 to 200 μm. .
この実施例２では酸化亜鉛粉末に対し0.01〜
1.0モル％の酸化ビスマスを添加して造粒し平均
粒径10〜200μｍの酸化亜鉛＋酸化ビスマス粒子
を得、これを酸化亜鉛＋MgO＋Bi2O3＋CoO＋
MnO＋NiO＋Sb2O3＋Cr2O3からなる主組成に対
し0.3〜30重量％添加混合し、これをいつしよに
焼結することによつて立上り電圧や非直線係数特
性の優れたバリスタを得ることができる。したが
つて酸化亜鉛の結晶粒成長を阻害するSb2O3や
Cr2O3を含む主組成に酸化亜鉛＋酸化ビスマス粒
子を添加した場合でも結晶粒は成長するので低電
圧化できる効果を有する。 In this Example 2, 0.01~
Bismuth oxide of 1.0 mol % is added and granulated to obtain zinc oxide + bismuth oxide particles with an average particle size of 10 to 200 μm, which are combined into zinc oxide + MgO + Bi 2 O 3 + CoO +
To obtain a varistor with excellent rise voltage and nonlinear coefficient characteristics by adding and mixing 0.3 to 30% by weight to the main composition consisting of MnO + NiO + Sb 2 O 3 + Cr 2 O 3 and sintering this at the same time. Can be done. Therefore, Sb 2 O 3 and
Even when zinc oxide + bismuth oxide particles are added to the main composition containing Cr 2 O 3 , the crystal grains grow, which has the effect of lowering the voltage.
以上述べたように本発明によればあらかじめ酸
化亜鉛＋酸化ビスマス粉末を造粒したのちこれを
酸化亜鉛を主とする主組成に添加混合−成形し焼
結してバリスタを得るもので、このバリスタは結
晶粒径が大きいので非直線係数を低下させずに立
上り電圧を低下させる特性を有し低電圧用に適用
するものである。 As described above, according to the present invention, a varistor is obtained by granulating zinc oxide + bismuth oxide powder in advance, adding it to a main composition mainly consisting of zinc oxide, mixing, molding, and sintering. Since the crystal grain size is large, it has the characteristic of reducing the rising voltage without reducing the nonlinear coefficient, and is suitable for low voltage applications.
また実施例では主組成として酸化亜鉛、酸化ビ
スマスにほかMgO、CoO、MnO、NiO、Sb2O3、
Cr2O3を添加した場合について述べたが、その他
の金属酸化物たとえばSiO2、CuO、Al2O3、
BaO、CaO、SrO、PbO、SnO2、Ag2O、TiO2、
ZrO2、La2O3、Pr6O11、Fe2O3、B2O3などを添加
してもよく、空気中高温で酸化物になるものなら
ばこれらに限るものではない。しかし本発明は主
組成としての酸化亜鉛と酸化ビスマスとに酸化亜
鉛＋酸化ビスマス粒子を加えた焼結体からなるも
のでバリスタの低電圧化の効果を得ることができ
るものであつて、前記MgO、CoOなどの金属酸
化物はバリスタとしての特性を向上させる効果は
有するが本発明の要旨たる低電圧化という観点か
らは必須要件ではない。 In addition to zinc oxide and bismuth oxide, the main compositions in the examples include MgO, CoO, MnO, NiO, Sb 2 O 3 ,
Although the case where Cr 2 O 3 is added has been described, other metal oxides such as SiO 2 , CuO, Al 2 O 3 ,
BaO, CaO, SrO, PbO, SnO2 , Ag2O , TiO2 ,
ZrO 2 , La 2 O 3 , Pr 6 O 11 , Fe 2 O 3 , B 2 O 3 and the like may be added, but are not limited to these as long as they become oxides at high temperatures in air. However, the present invention is made of a sintered body in which zinc oxide and bismuth oxide are added as main compositions, and zinc oxide + bismuth oxide particles are added to it, which can achieve the effect of lowering the voltage of the varistor. Although metal oxides such as CoO and CoO have the effect of improving the characteristics of a varistor, they are not essential from the viewpoint of lowering the voltage, which is the gist of the present invention.
図面はいずれも本発明および参考例、従来例の
特性を示す曲線図で第１図は酸化亜鉛に対する酸
化ビスマスの添加量と立上り電圧の関係、第２図
は同じく酸化ビスマスの添加量と非直線係数との
関係、第３図は主組成に対する酸化亜鉛＋酸化ビ
スマス粒子の添加量と立上り電圧との関係、第４
図は同じく酸化亜鉛＋酸化ビスマス粒子の添加量
と非直線係数との関係、第５図は酸化亜鉛＋酸化
ビスマス粒子の平均粒径と立上り電圧との関係、
第６図は同じく酸化亜鉛＋酸化ビスマス粒子の平
均粒径と非直線係数との関係、第７図〜第１２図
は他の実施例による特性を示す曲線図であり第７
図は酸化亜鉛に対する酸化ビスマスの添加量と立
上り電圧の関係、第８図は同じく酸化ビスマスの
添加量と非直線係数との関係、第９図は主組成に
対する酸化亜鉛＋酸化ビスマス粒子の添加量と立
上り電圧との関係、第１０図は同じく酸化亜鉛＋
酸化ビスマス粒子の添加量と非直線係数との関
係、第１１図は酸化亜鉛＋酸化ビスマス粒子の平
均粒径と立上り電圧との関係、第１２図は同じく
酸化亜鉛＋酸化ビスマス粒子の平均粒径と非直線
係数との関係を示す曲線図である。
The drawings are all curve diagrams showing the characteristics of the present invention, reference examples, and conventional examples. Figure 1 shows the relationship between the amount of bismuth oxide added to zinc oxide and the rise voltage, and Figure 2 shows the relationship between the amount of added bismuth oxide and the non-linearity. Figure 3 shows the relationship between the amount of zinc oxide + bismuth oxide particles added to the main composition and the rise voltage.
The figure also shows the relationship between the amount of zinc oxide + bismuth oxide particles added and the nonlinear coefficient, and Figure 5 shows the relationship between the average particle diameter of zinc oxide + bismuth oxide particles and the rising voltage.
FIG. 6 similarly shows the relationship between the average particle diameter and nonlinear coefficient of zinc oxide + bismuth oxide particles, and FIGS. 7 to 12 are curve diagrams showing characteristics according to other examples.
The figure shows the relationship between the amount of bismuth oxide added to zinc oxide and the rise voltage, Figure 8 shows the relationship between the amount of bismuth oxide added and the nonlinear coefficient, and Figure 9 shows the amount of zinc oxide + bismuth oxide particles added to the main composition. Figure 10 shows the relationship between the voltage and the rising voltage.
The relationship between the amount of bismuth oxide particles added and the nonlinear coefficient, Figure 11 shows the relationship between the average particle size of zinc oxide + bismuth oxide particles and the rise voltage, and Figure 12 shows the average particle size of zinc oxide + bismuth oxide particles. It is a curve diagram showing the relationship between and a nonlinear coefficient.
Claims (1)
たのち造粒し酸化亜鉛＋酸化ビスマス粒子を得る
工程と、該粒子を平均粒径により選別する工程
と、該工程で選別した粒子を少なくとも酸化亜鉛
と酸化ビスマスを含む主組成に添加混合して混合
粒子を得る工程と、該工程ののち混合粒子を成形
焼結する工程とを具備したことを特徴とするバリ
スタの製造方法。 ２ 造粒をスプレードライヤで行うことを特徴と
する特許請求の範囲第１項記載のバリスタの製造
方法。 ３ 酸化亜鉛に添加する酸化ビスマスの混合量が
0.01〜1.0モル％であることを特徴とする特許請
求の範囲第１項または第２項記載のバリスタの製
造方法。 ４ 酸化亜鉛＋酸化ビスマス粒子の平均粒径が10
〜200μｍであることを特徴とする特許請求の範
囲第１項〜第３項のいずれかに記載のバリスタの
製造方法。 ５ 主組成に添加混合する酸化亜鉛＋酸化ビスマ
ス粒子の添加量が0.3〜30重量％であることを特
徴とする特許請求の範囲第１項〜第４項のいずれ
かに記載のバリスタの製造方法。[Claims] 1. A step of mixing zinc oxide powder and bismuth oxide powder and then granulating them to obtain zinc oxide + bismuth oxide particles, a step of sorting the particles according to their average particle size, and a step of sorting the particles in the step. 1. A method for manufacturing a varistor, comprising the steps of: adding and mixing particles to a main composition containing at least zinc oxide and bismuth oxide to obtain mixed particles; and after this step, shaping and sintering the mixed particles. 2. The method for manufacturing a varistor according to claim 1, wherein the granulation is performed using a spray dryer. 3 The amount of bismuth oxide added to zinc oxide is
The method for manufacturing a varistor according to claim 1 or 2, wherein the content is 0.01 to 1.0 mol%. 4 The average particle size of zinc oxide + bismuth oxide particles is 10
The method for manufacturing a varistor according to any one of claims 1 to 3, wherein the thickness is 200 μm. 5. The method for manufacturing a varistor according to any one of claims 1 to 4, characterized in that the amount of zinc oxide + bismuth oxide particles added and mixed to the main composition is 0.3 to 30% by weight. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58158274A JPS6049608A (en) | 1983-08-29 | 1983-08-29 | Method of producing vaistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58158274A JPS6049608A (en) | 1983-08-29 | 1983-08-29 | Method of producing vaistor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6049608A JPS6049608A (en) | 1985-03-18 |
| JPH0142610B2 true JPH0142610B2 (en) | 1989-09-13 |
Family
ID=15668017
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58158274A Granted JPS6049608A (en) | 1983-08-29 | 1983-08-29 | Method of producing vaistor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6049608A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0630284B2 (en) * | 1987-09-11 | 1994-04-20 | 富士電機株式会社 | Method for manufacturing voltage non-linear resistance element |
-
1983
- 1983-08-29 JP JP58158274A patent/JPS6049608A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6049608A (en) | 1985-03-18 |
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