JPH05243012A - Voltage nonlinear resistance composition - Google Patents

Abstract

PURPOSE:To obtain the title composition proper for absorbing a surge by specifying the component, composition ratio and loadings of a bismuth borosilicate glass frit added to zinc oxide. CONSTITUTION:A 0.2-1.0wt.% bismuth borosilicate glass frit containing Bi of 0.05-2.0mol% in terms of Bi2O3, Sb of 0.05-2.0mol% in terms of Sb2O3, Co of 0.1-2.0mol% in terms of CoO, Mn of 0.1-3.0mol% in terms of MnO, Ni of 0.05-2.0mol% in terms of NiO, Ti of 0.05-2.0mol% in terms of TiO2, Si of 0.05-3.0mol% in terms of SiO2, Al of 0.001-0.5mol% in terms of Al2O3, and 1-10wt.% CoO is added to zinc oxide. Accordingly, a voltage nonlinear resistance composition having excellent high-temperature load lifetime characteristics and pulse lifetime characteristics can be acquired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage non-linear resistance composition containing zinc oxide as a main component and the sintered body itself having voltage non-linearity.

[0002]

2. Description of the Related Art Conventionally, the load life characteristics of zinc oxide (ZnO) varistors have not always been sufficient depending on the application. As a solution to this problem, a paste-like glass frit was applied to a sintered body made of zinc oxide, and heat treatment was applied to diffuse the glass to protect and reinforce the grain boundaries. However, there are problems such as a decrease in electrical characteristic value due to heat treatment and a large pulse deterioration. Further, since the amount of glass frit applied to the sintered body has a large influence on the varistor voltage, the voltage non-linearity coefficient, and the load life characteristic, it is necessary to strictly control the amount of paste-shaped glass frit applied. If the coating amount control is not carried out sufficiently, there are problems in that there is a large variation in the characteristics between the produced sintered bodies and the production yield also deteriorates. Further, when the shape of the sintered body is large, the glass diffusion becomes insufficient, the glass is not uniformly diffused into the inside of the sintered body, and the load life characteristics cannot be remarkably improved.

Therefore, in contrast to the above glass diffusion method, a glass addition method has been tried in which a glass frit such as bismuth borosilicate is added to a raw material before sintering and the glass is sintered at a temperature of 1100 to 1300 ° C.

[0004]

The above-mentioned glass addition method makes it easy to quantify the amount of glass frit added to the raw material, and also the complexity of the manufacturing process by the glass diffusion method, deterioration of characteristic values due to heat treatment, load life characteristics and varistor voltage. There is an advantage that variations in characteristic values such as are improved.

However, the voltage non-linear resistance composition produced has problems such as large deterioration of pulse even though the load life characteristic against direct current is improved, and very high varistor voltage due to low temperature firing.

Recently, zinc oxide varistor has been put to practical use in a wide range of applications for absorbing surges, but it is characterized by small pulse deterioration and excellent load life characteristics with respect to constant voltage application such as direct current and alternating current. Is a necessary condition for use.

Therefore, even in the above-mentioned glass addition method, there was a problem that the pulse deterioration was small and both conditions having excellent load life characteristics could not be sufficiently satisfied. The present invention solves the above-mentioned problems, and the components and composition ratio of the bismuth borosilicate glass frit to be added to zinc oxide, the addition amount thereof, and the combination thereof are sufficient to achieve both pulse life characteristics and load life characteristics. It is an object of the present invention to provide a voltage non-linear resistance composition satisfying the above conditions and satisfying the above-mentioned requirements for absorbing surge.

[0008]

The voltage non-linear resistance composition of the present invention is a voltage non-linear resistance composition in which a sintered body containing zinc oxide as a main component has voltage non-linearity. 0.05 to 2.0 mol% of bismuth in the form of Bi ₂ O ₃ and 0.05 to 2.0 mol% of antimony in the form of Sb ₂ O ₃ with respect to zinc oxide. , Cobalt to CoO
In the form of 0.1 to 2.0 mol% and manganese to Mn
Converted to form O, 0.1-3.0 mol%, nickel N
0.05 to 2.0 mol% in terms of the shape of iO, 0.05 to 2.0 mol% in terms of titanium in the form of TiO _2, in terms of silicon in the form of SiO ₂ 0.05 ~ 3.0 mol%,
Converting aluminum into Al ₂ O ₃ form 0.001
A bismuth borosilicate glass frit containing 0.5 mol% and 1 to 10% by weight of cobalt oxide is added in an amount of 0.2 to 1.0% by weight.

Both the pulse life and the load life at high temperature can be satisfied because nickel oxide and glass frit containing cobalt oxide in bismuth borosilicate glass coexist. This is probably because

[0010]

The reason why the components to be added to zinc oxide, which is the main component of the voltage nonlinear resistance composition, and the composition ratio thereof are selected as described above is that the voltage nonlinear resistance composition formed by adding the composition. This is also for satisfying both the pulse life and the load life at high temperature. In other words, if the composition of the component added to the main component zinc oxide is outside the range of the present invention, these target values cannot be achieved.

[0011]

EXAMPLES Specific examples of the present invention will be described below together with comparative examples.

Experimental Example 1 First, as raw materials, high-purity zinc oxide (ZnO), bismuth oxide (Bi ₂ O ₃ ), antimony oxide (Sb ₂ O ₃ ),
Cobalt oxide (CoO), manganese oxide (MnO), nickel oxide (NiO), titanium oxide (TiO ₂ ), silicon oxide (SiO ₂ ), and aluminum oxide (Al ₂ O ₃ ) were prepared.

Next, in preparing a bismuth borosilicate glass frit to be added to zinc oxide, 0.5 mol% of bismuth oxide, 0.5 mol% of antimony oxide, 0.5 mol% of cobalt oxide, 0.5 mol of manganese oxide. %, Nickel oxide 0.5 mol%, titanium oxide 0.5 mol%, silicon oxide 0.5 mol%, aluminum oxide 0.05 mol%, and the amount of cobalt oxide contained in the bismuth borosilicate glass frit. Was weighed so that the amount shown in Table 1 was obtained.

Then, each of the bismuth borosilicate glass frits having different cobalt oxide contents was added to the zinc oxide in an amount of 0.5% by weight and sufficiently mixed, and then PVA5 was added.
% Solution was added as a binder for granulation. Then, the obtained mixture was formed into a disc shape having a diameter of 14.0 mm, and the obtained formed product was fired in air at 1250 ° C. for 2 hours to prepare a resistance composition sample of a sintered body. did. After applying an electrode material paste containing silver on the front and back surfaces of each of the prepared resistance composition samples, the electrode material paste was baked at a temperature of 850 ° C. to form an electrode, and a lead wire was attached on the electrode with a solder containing silver. A voltage non-linear resistance composition was prepared.

With respect to each of the voltage non-linear resistance compositions provided with electrodes on the front and back sides, the varistor voltage per unit thickness (V1mA / mm), the voltage non-linear coefficient (α), the high temperature DC The electrical characteristics of the varistor voltage change rate (ΔV1mA) due to load life and high temperature AC load life, and the varistor voltage change rate due to pulse life (ΔV1mA) were measured, and the results are shown in Table 1.

The varistor voltage is measured by a constant current power supply, and the voltage nonlinear coefficient is

[0017]

[Equation 1]

The high temperature DC load life and the high temperature AC load life were measured by applying a DC power of 0.6 W or an AC power of 0.6 W for 1000 hours at an ambient temperature of 70 ° C. and a pulse life. A current of 200 A having a waveform of (8 × 20) microseconds was repeatedly applied 10 ³ times for measurement.

[0019]

[Table 1]

Those marked with * in Table 1 are outside the scope of the present invention, and others are within the scope of the present invention.

As is apparent from Table 1, the amount of cobalt oxide contained in the bismuth borosilicate glass frit is 1 to
It was confirmed that each electric property was excellent in the range of 10% by weight. When the amount of cobalt oxide in the bismuth borosilicate glass frit is less than 1% by weight, the voltage non-linearity coefficient is excellent, but the pulse life characteristics are not improved, and the amount of cobalt oxide in the bismuth borosilicate glass frit is small. Is more than 10% by weight, the voltage non-linearity coefficient decreases, the high temperature load life characteristics and the pulse life deteriorate greatly, and desired electrical characteristics cannot be obtained.

Experimental Example 2 In accordance with Experimental Example 1, the composition ratio of bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, nickel oxide, titanium oxide, silicon oxide and aluminum oxide was changed variously, and further cobalt oxide was contained. Each of the voltage non-linear resistance compositions was prepared in the same manner as in Experimental Example 1 by adding 0.5 wt% of bilimuth borosilicate glass frit to zinc oxide.

For each of the prepared voltage non-linear resistance compositions, the varistor voltage, the voltage non-linearity coefficient, the high temperature DC load life, the high temperature AC load life, and the same conditions as in Example 1 were used.
When the electrical characteristics of the pulse life were measured, each composition in the bismuth borosilicate glass frit added to zinc oxide was within the range of the present invention, that is, bismuth oxide was 0.0
5-2.0 mol%, antimony oxide 0.05-2.0
Mol%, cobalt oxide 0.1 to 2.0 mol%, manganese oxide 0.1 to 3.0 mol%, nickel oxide 0.0.
5 to 2.0 mol%, titanium oxide to 0.05 to 2.0 mol%, silicon oxide to 0.05 to 3.0 mol%, and aluminum oxide to 0.001 to 0.5 mol%. A voltage non-linear resistance composition using a bismuth borosilicate glass frit containing cobalt oxide in the range of 1 to 10 wt% has an excellent voltage non-linear coefficient, pulse life characteristics,
It also showed high temperature load life characteristics.

As described above, when each of the above compositions is out of the composition range of the present invention, any of the voltage non-linearity coefficient, high temperature DC load life, high temperature AC load life, and pulse life is reduced,
Alternatively, the desired electrical characteristics cannot be obtained due to deterioration.

Experimental Example 3 First, as raw materials, high-purity zinc oxide (ZnO), bismuth oxide (Bi ₂ O ₃ ), antimony oxide (Sb ₂ O ₃ ),
Cobalt oxide (CoO), manganese oxide (MnO), nickel oxide (NiO), titanium oxide (TiO ₂ ), silicon oxide (SiO ₂ ), and aluminum oxide (Al ₂ O ₃ ) were prepared.

Next, with respect to zinc oxide, bismuth oxide 0.
5 mol%, antimony oxide 0.5 mol%, cobalt oxide 0.5 mol%, manganese oxide 0.5 mol%, nickel oxide 0.5 mol%, titanium oxide 0.5 mol%, silicon oxide 0.1 mol %, Aluminum oxide 0.05 mol%, and the content of cobalt oxide in the bismuth borosilicate glass frit was 10% by weight.

Then, bismuth borosilicate glass frit was added to zinc oxide in an addition amount shown in Table 2, and after sufficiently mixing, a 5% PVA solution was added as a binder for granulation. The resulting mixture is then 14.0 m in diameter.
m in the shape of a disk, and the molded product obtained is 125
By firing at 0 ° C. for 2 hours, a resistance composition sample of a sintered body was prepared. After applying the electrode material paste containing silver to the front and back surfaces of each of the prepared resistance composition samples, the temperature was adjusted to 85
An electrode was formed by baking at 0 ° C., and a lead wire was attached on the electrode with silver-containing solder to prepare a voltage nonlinear resistance composition.

With respect to each of the voltage non-linear resistance compositions having electrodes on the front and back surfaces thus prepared, the varistor voltage, the voltage non-linear coefficient, the high temperature DC load life, the high temperature under the same conditions as in Experimental Example 1 above. Each characteristic of AC load life and pulse life was measured, and the results are shown in Table 2.

[0029]

[Table 2]

Those marked with * in Table 2 are outside the scope of the present invention, and others are within the scope of the present invention.

As is clear from Table 2, the addition amount of bismuth borosilicate glass frit to zinc oxide is 0.2-.
It was confirmed that each electric property was excellent in the range of 1.0% by weight. When the amount of the bismuth borosilicate glass frit added to zinc oxide is less than 0.2% by weight, the pulse life characteristics are excellent, but the high temperature load life characteristics are not improved, and the borosilicate added to zinc oxide. When the bismuth glass frit amount exceeds 1.0% by weight, the high temperature load life characteristics are improved, but on the other hand, the voltage non-linearity coefficient is lowered and the deterioration of the pulse life is increased to obtain the desired characteristics. Absent.

The present invention is not limited to this, and magnesium oxide (M
gO), chromium oxide (Cr ₂ O ₃ ), lead oxide (PbO)
Etc. may be added. By adding these, performances such as pulse life and high temperature load life can be further improved.

[0033]

As described above, according to the present invention, the zinc oxide varistor exhibits excellent characteristics against surges, and has excellent high temperature load life characteristics and pulse life characteristics without impairing these characteristics. It has the effect of providing a voltage non-linear resistance composition.

Claims (1)

[Claims] 1. A voltage non-linear resistance composition in which a sintered body containing zinc oxide as a main component itself has voltage non-linearity, and bismuth is formed into a form of Bi ₂ O ₃ with respect to zinc oxide as a main component. Converted to 0.05-2.0 mol%, antimony is added to Sb ₂ O ₃
Converted to the form of 0.05-2.0 mol%, cobalt to C
0.1 to 2.0 mol% in the form of oO, 0.1 to 3.0 mol% in the form of manganese in the form of MnO, and 0.05 to 2 in the form of nickel in the form of NiO. 0.0 mol%, 0.05 to 2.0 mol% in terms of titanium in the form of TiO ₂ ,
0.05 to 3.0 mol% of silicon in the form of SiO ₂ and 0.001 of aluminum in the form of Al ₂ O _3.
Bismuth borosilicate glass frit containing 0.5 to 0.5 mol% and cobalt oxide of 1 to 10 wt% is 0.2 to 1.0.
A voltage non-linear resistance composition characterized by being added by weight%.