JPS5941285B2 - Voltage nonlinear resistance element and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sintered bulk voltage non-linear resistance element which has excellent thermal runaway life during surges and is mainly composed of zinc oxide.

BACKGROUND ART Voltage nonlinear resistance elements (hereinafter referred to as varistors) are widely used in overvoltage protection elements and lightning arresters.

The varistor voltage (■) - current (I) % characteristic is expressed as follows.

However, C is a constant corresponding to resistance, and α is called a voltage nonlinear index.

Generally, the characteristics of a varistor are expressed by α and the varistor voltage, which is the voltage at a specific current.

α is usually determined from voltage-current characteristics at 0.1 to 1 mA/C7rL.

Further, for convenience, the varistor voltage is often expressed as a terminal voltage (V 1 mA) when a current of 1 mA flows.

As a varistor, the varistor voltage is in an appropriate range (usually several tens to several hundreds of volts per mvt thickness),
The larger α is, the more desirable it is.

Furthermore, when used in overvoltage protection elements and lightning arresters, the lower the limiting voltage characteristic (usually expressed as the ratio of the voltage V The larger the impact current (expressed as the value of the impulse current at which the rate of change of the varistor voltage remains within the allowable range even when applied) is more suitable.

Furthermore, from the viewpoint of reliability, it is desirable to have a material that is stable against changes in temperature and environment.

As varistors, SiC varistors are made of silicon carbide sintered at high temperatures, and ZnO varistors, in which the sintered body itself containing zinc oxyoxide as a main component exhibits voltage nonlinearity (bulk voltage nonlinearity), are well known.

However, when considered as an overvoltage protection element or lightning arrester,
In almost all of the above characteristics, ZnO varistors are better than Si.
It is superior to C varistors, and currently mainly ZnO
Ballistas have come into use.

ZnO varistors contain bismuth oxide (ZnO) as the main component.
B1203), cobalt oxide (C0203), manganese oxide (Mn 02 ), etc. are added and mixed in small amounts, and after molding, the mixture is sintered at 100°C to 1400°C.

The ZnO varistor made in this way is different from the conventional Si
While the α of C barista was 3 to 7, it was 30 to 5.
Since it is possible to obtain 0 or more, it has become the mainstream of overvoltage protection elements.

In particular, when used as a lightning arrester, it is thought that it can be applied as a so-called gapless lightning arrester without connecting the discharge gap in series.

However, in order to use it as a gapless arrester, there are problems that must be further improved.

That is, since the device is gapless, a voltage is constantly applied to the ZnO varistor, which causes a problem in that the device deteriorates and thermal runaway occurs.

Among them, the most important practical problem is the thermal runaway life when not only the applied voltage but also surge current is repeatedly applied.

When using a ZnO varistor as a gapless lightning arrester, the varistor voltage of the element is usually designed so that the peak value of the applied voltage is 50 to 80% of the varistor voltage.

Therefore, for example, in the case of a 60kV lightning arrester, the varistor voltage is set to 120kV to 75kV.

Furthermore, when considering Japan, although it varies depending on the location, it is estimated that
There are thunderstorms for about 0 to 30 days, and each time a surge voltage is applied to the lightning arrester, a surge current flows.

If one lightning strike causes about 10 shock currents to flow, this means that about 100 to 300 shock currents will be applied each year.

Since lightning arresters usually require a lifespan of 20 years or more, a total of 2,000 to 6,000 surge currents will be applied to the applied voltage of 60 kV.

The average surge current is considered to be about 100A with a waveform of 8 x 20μs, so when used as a gapless arrester, the surge current of 2000 to 6000 times at 100A will weigh the AC applied voltage by 50% to 80% of the varistor voltage. It is necessary that thermal runaway does not occur even if the heat is applied in this way.

However, although conventional ZnO varistors are excellent in terms of the above-mentioned α, limiting voltage characteristics, surge withstand capacity, and stability against changes in environmental conditions, they have the condition that the surge current starts to overlap with the applied voltage as just mentioned. However, there was no material with sufficient thermal runaway life.

In view of the above-mentioned problems, the present invention aims to propose a voltage non-linear resistance element with excellent thermal runaway life characteristics during surge current flux, and a method for manufacturing the same.Details thereof are explained below along with examples. do.

(Example 1) A small amount of Bi2O3, CO□032Mn02 in ZnO powder
゜5b2o3. Cr2O3, NiO, 5i02. Al2
Add O3゜B2O3 powder in various amounts,
Mix thoroughly and apply a pressure of 250 kg/ffl to a diameter of 17.5
It was compression molded into a disk shape with a thickness of 1 mu and 2 mu.

Then, it was fired in air at 1230° C. for 2 hours, and the flat surface was polished, and an aluminum sprayed electrode was provided.

Varistor voltage per unit thickness of the element obtained in this way (V1mA/'') tα, voltage at 100A (
■Limiting voltage ratio (v1ooA//V1mA) expressed as the ratio of voltage at 100A) and voltage at 1mA (■1mA), 8×
2 impulse currents of 100 OA in the same direction with a 20 μs waveform
Surge resistance expressed as the rate of change in varistor voltage after application of 100A with a waveform of 8 x 20μs when applying a 60Hz alternating voltage with a peak value of 80% of the varistor voltage in a constant temperature oven at 100℃ The impact current of 1
The results of measuring the time until thermal runaway occurs when the pulse is applied 40 times per hour (thermal runaway life when the pulse is applied) are as follows.
Shown in the table.

(Tables 1 to 4 are attached at the end of the specification.

) The amount of ZnO in this example is the amount obtained by subtracting the mol % occupied by the total amount of additives from 100 mol %, and the same applies to each of the following examples.

As shown in Table 1, 0.1 to 3.0 mol% Bl
2. o3j O, 1-3.0 mol% Co2O3,
0.1-3.0 mol% MnO2t 0.1-3.0 mol% 5b203° 0.05-1.5 mol% Cr2O
3.0.1 to 3.0 mol% NiO, 0.1 to 10.0
A sintered body containing mol% SiO2, 0.0005 to 0.025 mol% Al2O3, 0,005 to 0.3 mol% B2O3 has an α of 40 or more and a v1ooA/v1mA of 1.
．． 60 or less, surge resistance is -3.0% or less, and pulse thermal runaway life is more than 150 hours.
Such characteristics cannot be obtained even if any one of the nine additives mentioned above is missing.

For example, without B 1203, α is less than 30, Vloo
A/Vl mA is 1.60 or more, surge resistance car 3.
0% or more, the thermal runaway life under pulse stress is 150 hours or less.

B 120 also in the absence of Co2O3 or Mn 02
This is the same as when s is not included.

Also, if there is no 5b203, the surge resistance will be -3.0%
As a result, the thermal runaway life due to pulse overload is 150 hours or more.

When Cr2O3, NiO, or 5i02 is not included, the same characteristics as when 5b203 is not included are not as excellent.

Even when aluminum or boron is not included, the surge resistance is -3.0% or more, and the pulse-heavy thermal runaway life is 150 hours or less.

From the above results, the desired characteristics of this example can only be obtained when all of the above nine components are contained at the same time, and cannot be obtained if even one of the components is missing.

In particular, it can be seen that when aluminum and boron are present at the same time, there is a significant improvement in the thermal runaway life of pulsed heat.

In the absence of aluminum or boron, the pulsed thermal runaway life was less than 10 hours.

(Example 2) A small amount of Bi2O3, Co2032MnO3 in ZnO powder
゜5b203. Cr2O3, NiO2SiO2, Ga2
Add O3゜B2O3 powder in various amounts,
A sample was prepared in the same manner as in Example 1.

vl mA/”lα of the device thus obtained.

Table 2 shows the results of measuring the surge withstand capacity and pulse thermal runaway life (V 100 A/vt mA).

The measurement conditions are the same as in Example 1.

Table 2 also shows the results when even one additive was missing as a comparative example.

As can be seen from Table 2, 0.1 to 3.0 mol% Bi2
O3,0,1-3.0 mol% Co2O3,0,1-3
．． 0 mol% M n 02 + 0.1-3.0 mol%
5b203゜0.05-1.5 mol% Cr2O3,
0.1-3.0 mol% NiO, 0.1-10.0 mol% SiO2゜0.0005-0.025 mol% Ga
2O3, the sintered body containing 0,005 to 0.3 mol% of B2O3 has α of 40 or more;

oA/v1mA is 1.60 or less, surge resistance is -3.0
% or less, the thermal runaway life under pulsed heating is 150 hours or more, and such characteristics cannot be obtained even if any one of the nine additives mentioned above is missing.

For example, without B 1203, α is less than 30, Vloo
V/Vt mA is 1.60 or more, surge resistance is -
3.0% or more, the thermal runaway life under pulse stress is 150 hours or less.

The case where Co2O3 or MnO2 is not included is the same as the case where Bi2O3 is not included.

Also, if there is no 5b203, the surge resistance will be -3.0%
As a result, the thermal runaway life due to pulse stress is 150 hours or less.

Even when Cr 20 s, NiO, or SiO2 is not included, the properties are not as good as when 5b203 is not included.

Even if potassium or boron is not included, the surge resistance is -3.0% or more, and the thermal runaway life due to pulsed heat is 1.
Less than 50 hours.

From the above results, the desired characteristics of this example can only be obtained when all of the above nine components are contained at the same time, and cannot be obtained if even one of the components is missing.

In particular, it can be seen that when gallium and boron are present at the same time, there is a significant improvement in the thermal runaway life of pulsed heat.

The pulse thermal runaway life in the absence of gallium or boron was less than 10 hours.

(Example 3) A small amount of Bi2O3, Co2032MnO2 in ZnO powder
゜5b203, Cr2O3, Nip, 5i02,
Al2O3.

Samples were prepared in the same manner as in Example 1 by adding powders of B2O3 and Ag2O in various amounts.

vl mA/”1α,v of the device obtained in this way
Table 3 shows the results of measuring the 1ooA/v1mA1 surge withstand capacity and pulse thermal runaway life.

The measurement conditions are the same as in Example 1.

Note that Table 3 also shows the results when even one additive was missing as a comparative example.

As shown in Table 3, 0.1 to 3.0 mol% Bi2
O3,0,1-3.0 mol% Co2O3,0,1-3
．． 0 mol% MnO2, 0.1-3.0 mol% 5b2
03゜0.05~1.5 mol% Cr2O3,0,1~
3.0 mol% NiO, 0.1-10.0 mol% 5I
O2゜0.0005-0.025-E/l/% Al2
O3,0,oo5-0.3 mol% B2O3,0,00
The sintered body containing 05 to 0.3 mol% Ag2O has α of 50
As mentioned above, it has the characteristics of vloo A/VlmA of 1.60 or less, surge resistance of -3.0% or less, and pulse overheating thermal runaway life of 190 hours or more, and these characteristics are achieved by the addition of the above 10 components. It cannot be obtained even if any one thing is missing.

For example, without Bi2O3, α is less than 50, v1ooV
/v1mA is 1.60 or more, the surge withstand capacity is -3.0% or more, and the thermal runaway life under pulse stress is 190 hours or less.

The case where CO2O3 or Mn 02 is not included is the same as the case where Bi2O3 is not included.

Also, if there is no 5b203, the surge resistance will be -3.0%
As a result, the thermal runaway life due to pulse stress becomes 190 hours or less.

When Cr2O3, NiO, or 5i02 is not included, the same characteristics as when 5b203 is not included are not as excellent.

Even when aluminum or boron is not included, the surge resistance is -3.0% or more, and the thermal runaway life under pulse stress is 190 hours or less.

Further, if silver is not included, the thermal runaway life due to pulsed heating is 190 hours or less.

From the following results, the desired characteristics of this example can only be obtained when all of the above ten components are included at the same time, and cannot be obtained if even one of the components is missing.

In particular, it can be seen that when aluminum, silver, and boron are present at the same time, there is a significant improvement in the thermal runaway life of pulsed heat treatment.

(Example 4) A small amount of Bi2O3, Co2032MnO2 in ZnO powder
゜5b203. Cr2O3, Nip, 5in2. Ga2
Samples were prepared in the same manner as in Example 1 by adding powders of O3°B2O3 and Ag2O in various amounts.

v1mA/mm of the device obtained in this way, α2V1
oo A/Vl mA The results of measuring the N surge withstand capacity and pulsed thermal runaway life are shown in Table 4.

The measurement conditions are the same as in Example 1.

Table 4 also shows the results when even one additive was missing as a comparative example.

As can be seen from Table 4, 0.1 to 3.0 mol% Bi
2O3, 0,1-3.0 mol% Co2O3,0,1-
3.0 mol% Mn 02 t 0.1-3.0 mol%
5b203°0.05-1.5 mol% Cr203
．． 0.1-3.0 mol% NiO, 0.1-10.0 mol% 5in2゜0.0005-0.025 mol% G
a2O3,0, Oo5 to 0.3 mol% B2O3,0,
The sintered body containing 0005 to 0.3 mol% Ag2O has an α of 50 or more, a v1ooA/v1mA of 1.60 or less, a surge resistance of -3.0% or less, and a pulsed thermal runaway life of 190 hours or more. These characteristics cannot be obtained even if any one of the above 10 additives is missing.

If there is no Bi2O3, α is less than 50, v1ooV
/v1mA is 1.60 or more, the surge withstand capacity is -3.0% or more, and the thermal runaway life under pulse stress is 190 hours or less.

The case where C020s or MnO2 is not included is the same as the case where B 1203 is not included.

Also, if there is no 5b203, the surge resistance will be -3.0%
As a result, the thermal runaway life due to pulse stress is 190 hours or less.

Even when Cr2O3, NiO, or SiO2 is not included, the same characteristics as when 5b203 is not included are not excellent.

Even if gallium or boron is not included, the surge withstand capacity is -3.0% or more, and the thermal runaway life due to pulse stress is 1.
It will be 90 hours or less.

Further, if silver is not included, the thermal runaway life due to pulsed heating is 190 hours or less.

From the above results, the desired characteristics of this example can only be obtained when all of the above ten components are included at the same time, and cannot be obtained if even one of them is missing.

In particular, it can be seen that when gallium, silver, and boron are present at the same time, there is a significant improvement in the thermal runaway life of pulsed heat treatment.

(Example 5) Bi2O3, Co2O3)Mn02, 5b203. of material composition A6a 1 or A6b 1 was added to ZnO powder. C
r2O3.

Nip, 5in2. Al2O3 or Ga20s
A sample was prepared in the same manner as in Example 1 by adding 0.3 weight of glass powder having the composition shown in Table 5 based on the total weight.

v1rTIA/7n7n of the device obtained in this way,
α, surge resistance and pulse thermal runaway life
Shown in the table.

As shown in Table 6, by adding boron together with a portion of silicon as a borosilicate glass powder having the composition shown in Table 5, α is improved and the thermal runaway life due to pulse heating is improved.

In all of the experimental compositions compared to the case where boron was added alone, the characteristics were improved by about 10 in α and about 10 hours in thermal runaway life under pulse stress.

Therefore, in this case, α is 50 or more, v1ooA/
A v1mA of 1.60 or less, a j--resistance of -3.0% or less, and a thermal runaway life of 160 hours or more under pulse stress were obtained.

This effect was first achieved by adding vitrified boron.

In addition, such an effect is caused by Bi2O3゜CO203, Mn0
2j S b203 , Cr 20s , N 10 t
It can only be obtained when it is added to a material containing eight components, S i02 HA 1203 or Ga2O3, and the above characteristics cannot be obtained even if one of the eight components is missing.

This applies to each of the following examples (Example 6 to Example 14)
The same applies to

(Example 6) Bi2 with material composition Aa-1 or ab-i in ZnO powder
O3, Co2d32MnO2, 5b203. Cr2O3
゜NiO,5i02. A sample was prepared in the same manner as in Example 1 by adding Al2O3 or Ga2O3 and 0.3 weight of glass powder having the composition shown in Table 7 based on the total weight.

Table 8 shows the v1mA/''jα, surge withstand capacity, and thermal runaway life of the device thus obtained.

As shown in Table 8, by adding boron together with bismuth and a part of silicon as bismuth borosilicate glass powder having the composition shown in Table 7, α is improved and the thermal runaway life during pulsed heating is improved. .

Compared to the case where boron was added alone, in all the compositions tested, the characteristics were improved by about 10 in α and about 20 hours in pulse-induced thermal runaway life.

Therefore, in this case, α is 50 or more, V1ooA/V1mA is 1.60 or less, and surge resistance is -3.
, 0% or less, and a thermal runaway life of 170 hours or more can be obtained.

This effect first appeared when boron was vitrified and added together with bismuth.

(Example 7) Material composition A6a l or /16. b 1
Bi2O3, Co2O3, MnO2,5b203,
Cr2O3.

A sample was prepared in the same manner as in Example 1 by adding Ni05SiO2, Al2O3 or Ca2O3 and 0.3 weight of glass powder having the composition shown in Table 9 based on the total weight.

Table 10 shows the v1mAZ ratio, α, surge withstand capacity, and thermal runaway life of the device thus obtained.

As shown in Table 10, boron is added to the
By adding it as a zinc borosilicate glass powder having the composition shown in Table 0, α is improved and the thermal runaway life under pulsed heating is improved.

Compared to the case where boron was added alone, in all the compositions tested, the characteristics were improved by about 10 in α and about 20 hours in pulse-induced thermal runaway life.

Therefore, in this case, α is 50 or more, V1ooA/
A V1mA of 1.60 or less, a surge resistance of -3.0 or less, and a thermal runaway life of 170 hours or more can be obtained.

This effect was first achieved by adding boron together with zinc in the form of vitrification.

(Example 8) Bi2O3, Co2032MnO2, 5b203. of material composition /16a-1 or /16b-1 was added to ZnO powder. Cr
2O3゜Nl02S102 , Al2O3 or Ga2
A sample was prepared in the same manner as in Example 1 by adding O3 and glass powder having the composition shown in Table 11 in an amount of 0.3 weight based on the total weight.

v1mA/717IL of the device obtained in this way, α
, surge resistance and pulse thermal runaway life are 12th.
Shown in the table.

As shown in Table 12, boron is added to the
By adding it as a lead borosilicate glass powder having the composition shown in Table 1, α is improved and the thermal runaway life under pulsed heating is improved.

Compared to the case where boron was added alone, in all the compositions tested, the characteristics were improved by about 10 in α and about 20 hours in pulse-induced thermal runaway life.

Therefore, in this case, α is 50 or more, v1ooA/
v1mA is 1.60 or less, surge resistance is -3.0% or less,
A thermal runaway life of 170 hours or more can be obtained during pulsed heating.

This kind of effect first appeared when boron was added together with lead in the form of vitrification.

(Example 9) ZnO powder with material composition A6 a-1 or /f6b 1
Bi2O3, Co2032MnO2, 5b203. C
r2O3゜NiO2SiO2, Al2O3 or Ga
Example 1
Samples were prepared in the same manner as.

v1r11A/m771 of the device thus obtained.
α, surge resistance and pulse thermal runaway life are the first
4.

As shown in Table 14, by adding boron together with cobalt, bismuth, and part of silicon as a cobalt-doped bismuth borosilicate glass powder with a composition shown in Table 13, α is improved, and pulsed heating Runaway life is improved.

Compared to the case where boron was added alone, in all the compositions tested, the characteristics were improved by about 10 in α and about 20 hours in pulse-induced thermal runaway life.

Therefore, in this case, α is 60 or more, v1ooA/
v1mA is 1.60 or less, surge resistance is -3.0% or less,
A thermal runaway life of 170 hours or more can be obtained during pulsed heating.

This effect was first achieved when boron was vitrified and added together with cobalt and bismuth.

(Example 10) Material composition/16a-1 or %b 1 of Bi OCo OMnO2,5b203. A sample was prepared in the same manner as in Example 1 by adding Cr2O3°23?23j NiO2SiO2, Al2O3 or Ga2O3 and adding 0.3 weight of glass powder having the composition shown in Table 15 based on the total weight.

V 1 mA /m1tt of the device obtained in this way
, α, surge withstand capacity, and pulse thermal runaway life are shown in Table 16.

As shown in Table 16, by adding boron and silver together with a portion of silicon as a silver-doped borosilicate glass powder with a composition shown in Table 15, α is improved and the thermal runaway life due to pulsed heating is improved. Improved.

Compared to the case where boron and silver were added alone, in all the compositions tested, the characteristics were improved by about 10 in α and about 20 hours in pulse-induced thermal runaway life.

Therefore, in this case, α is 50 or more, and Vloo A
/Vl mA of 1.60 or less, surge resistance of -3°0% or less, and pulsed thermal runaway life of 210 hours or more.

This kind of effect first appeared when boron and silver were added in the form of vitrification.

(Example 11) Adding Bi of material composition 4a-1 or /16b-1 to ZnO powder
2O3, Co2O3, MnO2, 5b203. Cr2O
3°Nip, 5in2. Al2O3 or Ga20
A sample was prepared in the same manner as in Example 1 by adding s and 0.3 weight of glass powder having the composition shown in Table 17 based on the total weight.

Table 18 shows the 1 mA/''tα, surge withstand capacity, and thermal runaway life of the device thus obtained.

As shown in Table 18, by adding boron and silver together with bismuth and a part of silicon as a silver-doped bismuth borosilicate glass powder with a composition shown in Table 17, α is improved, and pulsed heating Runaway life is improved.

Compared to the case where boron and silver were added alone, in all the compositions tested, the characteristics were improved by about 10 in α and about 30 hours in pulse-induced thermal runaway life.

Therefore, in this case, α is 60 or more, v1ooA/
v1mA is 1.60 or less, surge resistance is -3.0% or less,
A thermal runaway life of 220 hours or more can be obtained under pulsed heating.

This effect first appeared when boron and silver were vitrified and added together with bismuth.

(Example 12) B of material composition Aa-1 or /i6b 1 in ZnO powder
i2O3, Co2032MnO2, 5b203. Cr2
O3゜NiO2SiO2, Al2O3 or Ga2O3
A sample was prepared in the same manner as in Example 1 by adding 0.3 weight of glass powder having the composition shown in Table 19 based on the total weight.

v1mA//m7IL of the device obtained in this way, α
, surge withstand capacity and pulse thermal runaway life
Shown in the table.

As shown in Table 20, by adding boron and silver together with a portion of silicon as a silver-doped zinc borosilicate glass powder with a composition shown in Table 19, α is improved and the pulsed thermal runaway life is improved. is improved.

Compared to the case where boron and silver were added alone, in all the compositions tested, the characteristics were improved by about 10 in α and about 30 hours in pulse-induced thermal runaway life.

Therefore, in this case, α is 60 or more, v100A/
v1mA is 1.60 or less, "j--shi1ilFt amount 3.
0% or less, and a thermal runaway life of 220 hours or more can be obtained.

This effect first appeared when boron and silver were vitrified and added together with zinc.

(Example 13) ZnO powder with material composition A6. B of a1 or /l6b-1
i2O3, Co2032MnO2, 5b203. Cr2
O3゜NiO2SiO2, A1□03 or Ga2O3
A sample was prepared in the same manner as in Example 1 by adding 0.3 weight of glass powder having the composition shown in Table 21 based on the total weight.

Table 22 shows the v1mA/''tα, surge withstand capacity, and thermal runaway life of the device thus obtained.

As shown in Table 22, by adding boron and silver together with a part of silicon as silver-doped lead borosilicate glass powder with a composition shown in Table 21, α is improved and the pulsed thermal runaway life is improved. is improved.

Compared to the case where boron and silver were added alone, in all the compositions tested, the characteristics were improved by about 10 in α and about 30 hours in pulse-induced thermal runaway life.

Therefore, in this case, α is 60 or more, v1ooA/
V1mA is 1.60 or less, surge resistance -3.0% or less,
A thermal runaway life of 220 hours or more can be obtained under pulsed heating.

This effect first appeared when boron and silver were added together with lead in a vitrified form.

(Example 14) B of material composition Aa-1 or /I6b 1 in ZnO powder
i2O3, Co2032MnO2, 5b203. Cr2
O3゜Ni02Si02. Al2O3 or Ga2
A sample was prepared in the same manner as in Example 1 by adding 0.3 s of glass powder having the composition shown in Table 23 to the total weight.

Table 24 shows the v1mA/''jα, surge withstand capacity, and thermal runaway life of the device thus obtained.

Silver having a composition as shown in Table 23, containing boron and silver as shown in Table 24, along with cobalt, bismuth and a part of silicon,
By adding cobalt as a doped bismuth borosilicate glass powder, α is improved and the thermal runaway life during pulsed heating is improved.

Compared to the case where boron and silver were added alone, in all the compositions tested, the characteristics were improved by about 20 in α and about 30 hours in pulsed thermal runaway life.

Therefore, in this case, α is 70 or more, v1ooA/
v1mA is 1.60 or less, surge resistance is -3.0% or less,
A thermal runaway life of 220 hours or more can be obtained under pulsed heating.

This effect first appeared when boron and silver were vitrified and added together with cobalt and bismuth.

In addition, in the above examples, oxides were used in all cases. Even if it is added in the form, it does not impair the effects of the present invention.

The device according to the present invention has α, as described above.

It has excellent Vloo A/ Vl mA N surge resistance and thermal runaway life during pulse overload, and is therefore particularly useful when used as a gapless lightning arrester.

The figure shows an example of the structure of a typical lightning arrester using the element according to the present invention.

In the figure, 1 is a voltage nonlinear resistance element, 2a and 2b are a pair of electrodes provided on the voltage nonlinear resistance element, 3 is a high voltage side electrical terminal electrically connected to one electrode 2a, and 4 is the other electrode. a ground side electrical terminal electrically connected to the electrode 2b;
6 is an insulating container, 6 is a spring for holding the voltage nonlinear resistance element, and 7 is a conducting wire connecting one electrode 2a and the high voltage side electric terminal 3.

By creating a lightning arrester with a simple structure that does not use a gap in this way, a small and lightweight lightning arrester can be obtained.

Also, in terms of characteristics, there is no discharge delay or follow-on current that is seen in gap type devices.

Furthermore, compared to a conventional lightning arrester using a ZnO varistor, it has an advantage of superior long-term reliability due to its superior pulse-induced thermal runaway life.

As explained in detail above, the present invention provides zinc oxide with Bi2O
3, Co2032MnO2,5b203. Cr2O3゜NiO2SiO2, Al2O3 or Ga 203
+ When B203 is present at the same time, or when Bi2O3°Co2032Mn02,5b203. C
r2O3, Ni02Si02. Al2O3 or Ga2
It can only be obtained when O3, B2O3, and Ag2O exist simultaneously, and thereby α, v1ooA/
It is possible to provide a voltage nonlinear resistance element with excellent v1mA1 surge resistance and pulsed thermal runaway life.

Moreover, the above characteristics can be further improved by adding boron or boron and silver in vitrification when adding the above additives.

Therefore, by using the voltage nonlinear resistance element according to the present invention, the safety and reliability of equipment and equipment can be improved with a simple configuration.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view showing an embodiment of a lightning arrester using the voltage nonlinear resistance element of the present invention. 1... Voltage nonlinear resistance element, 2a, 2b...
···electrode.

Claims (1)

[Scope of Claims] 1 0.1 to 3.0 mol% of Bi2O3, 0.1 to 3.0 mol% of Co2O3, and 0.1 to 3.0 mol% of MnO2. 0.1 to 3.0 mol% of 5b203 and 0.1 to 3.0 mol% of Cr2O3.
05 to 1.5 mol%, NiO 0.1 to 3.0 mol%,
0.1 to 10.0 mol% of 5102, 0.0005 to 0.025 mol% of Al2O3 or Ga20a,
A voltage nonlinear resistance element made of a sintered body mainly composed of Zno containing B2O3 as an additive of 0.005 to 0.3 mol%. 2 0.1 to 3.0 mol% of Bi2O3, 0.1 to 3.0 mol% of Co2O3, 0.1 to 3.0 mol% of 2Mn02. 0.1 to 3.0 mol% of 5b203 and 0.1 to 3.0 mol% of Cr2O3.
05 to 1.5 mol%, NiO 0.1 to 3.0 mol%,
0.1 to 10.0 mol% of SiO2, 0.0005 to 0.025 mol% of Al2O3 or Ga2O3, B2O
0.005 to 0.3 mol% of 3, 0.000 of Ag2O
A voltage nonlinear resistance element comprising a sintered body mainly containing ZnO as an additive in an amount of 5 to 0.3 mol%. 3 0.1 to 3.0 mol% in terms of B12O3 form
bismuth compound, converted to CO2O3 form from 0.1 to
3.0 mol% cobalt compound, 0.1-3.0 mol% manganese compound in the form of MnO2, 5b203
0.1 to 3.0 mol% antimony compound in the form of 0.05 to 1.5 mol% in the form of Cr2O3
Chromium compound, converted to NiO form, 0.1 to 3.0
Mol% of nickel compound, converted to 5IO2 form, 0.
1 to 10.0 mol% silicon compound, Al2O3 or G
a 0.0005 to 0.02 converted to the form of 20 s
5 mol% aluminum or gallium compound,
When adding and mixing 0.005 to 0.3 mol% of a boron compound in the form of B2O3 to zinc oxide powder, all of the boron and at least a part of the silicon are vitrified and mixed, and this mixture is 1. A method for manufacturing a voltage nonlinear resistance element, which comprises molding and then firing. 4 B2O3 is 5-30% by weight, SiO2 is 70-95%
4. Process according to claim 3, characterized in that all of the boron and part of the silicon are added in the form of borosilicate glass powder with a composition of % by weight. 5 Bi2O3 is 40-90% by weight, B2O3 is 5-3
Claim 3, characterized in that all of the boron and part of the bismuth and silicon are added in the form of bismuth borosilicate glass powder with a composition of 0% by weight and 5-30% by weight of 5iO2. manufacturing method. 6Bi203 is 40-85% by weight, B2O3 is 5-25%
Weight%, 5102 is 5-25% by weight, Co2O3 is 2-25% by weight
Preparation according to claim 3, characterized in that all the boron and part of the bismuth, cobalt and silicon are added in the form of bismuth borosilicate glass powder doped with cobalt of a composition of 10% by weight. Method. 7 ZnO is 20-60% by weight, B2O3 is 5-30%
Claim 3, characterized in that all of the boron and part of the silicon and zinc are added in the form of zinc borosilicate glass powder with a composition of 10 to 60% by weight, 5in2. Production method. 8 PbO is 10-70% by weight, B2O3 is 5-30%
The manufacturing method according to claim 3, characterized in that all of the boron and part of the silicon are added in the form of lead borosilicate glass powder with a composition of 10 to 60% by weight, 5in2. . 9 Bismuth compound of 0.1 to 3.0 mol% in terms of Bi2O3 form, 0.1 to 3% in terms of Co2O3 form
．． 0 mol% of cobalt compounds, 0.1 to 3.0 mol% of manganese compounds in the form of MnO2, 0.1 to 3.0 mol% of antimony compounds in the form of 5b203, in the form of Cr2O3 0.05-1.5 mol% of chromium compounds in the form of NiO, 0.1-3.0 mol% of nickel compounds in the form of NiO, 0.1 in the form of SiO2.
~10.0 mol% silicon compound, Al2O3 or Ca
0.0005 to 0.025 mol% converted to 2O3 form
aluminum or potassium compounds, B2O3
When adding and mixing 0.005 to 0.3 mol% of a boron compound in the form of 0.005 to 0.3 mol% of a silver compound in the form of Ag2O to zinc oxide powder, boron 1. A method for manufacturing a voltage nonlinear resistance element, comprising vitrifying and adding and mixing all of silver and at least a part of silicic acid, molding this mixture, and then firing it. 10B203 is 5-30% by weight + S t 02 is 45
Claim 1 characterized in that all of the boron and silver and part of the silicon are added in the form of a silver-doped borosilicate glass powder with a composition of ~90% by weight and 3-25% by weight of Ag2O. The manufacturing method according to item 9. 11 Bi2O3 is 45-85% by weight, B2O3 is 5-85% by weight
25% by weight S102 5-25% by weight, Ag2O 3
Claim 9, characterized in that all of the boron and silver and part of the bismuth and silicon are added in the form of silver-doped bismuth borosilicate glass powder with a composition of ~25% by weight. Production method. 12Bi203 is 45-85% by weight, B2O3 is 5-2
5% by weight, 5-25% by weight of 5i02, 2% of Co2O3
In the form of cobalt, silver-doped bismuth borosilicate glass powder with a composition of ~10% by weight and 3-25% by weight of Ag2O, characterized by the addition of all of the boron and silver and part of the cobalt and silicon to the bismuth. The manufacturing method according to claim 9. 13 ZnO is 20-60% by weight, B2O3 is 5-30%
wt%, SiO2 10-60 wt%, Ag2O 3-60 wt%
Preparation according to claim 9, characterized in that all the boron and silver and part of the zinc silico are added in the form of a zinc borosilicate glass powder doped with silver of a composition of 25% by weight. Method. 14 PbO is 10-70% by weight, B2O3 is 5-30%
wt%, SiO2 10-60 wt%, Ag2O 3
Process according to claim 9, characterized in that all the boron and silver and part of the silicon are added in the form of lead borosilicate glass powder doped with silver with a composition of ~25% by weight. .