JPS60167304A - Voltage nonlinear resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a voltage nonlinear resistor whose main component is zinc pharyngeal.

BACKGROUND OF THE INVENTION In general, this type of voltage nonlinear resistor has excellent nonlinearity and is therefore suitably used in surge absorbers of cardiac equipment. The production of this German air-blow non-linear resistor consists of zinc oxide (ZnO) as the main component and bismuth oxide (
This is done by mixing additive components including Bi, O, ) as subcomponents, molding the mixture, and then firing it. The reason why bismuth oxide is added here is that since it has a lower melting point than zinc oxide, it promotes crystal growth of bleached zinc particles through liquid phase sintering, but conventionally, this function was not achieved. For example, 0.3 mol% 1g
Bismuth oxide was used in the upper part.

By the way, when manufacturing a voltage nonlinear resistor, in order to improve the life characteristics of the resistor or to prepare an insulating coating on the outer periphery of the resistor, it is necessary to
``A heat treatment process is required, but this heat treatment after sintering changes the crystal system of bismuth oxide.As a result, the electrical characteristics of the voltage nonlinear resistor are greatly reduced, and its failure is caused by high heat treatment temperatures. As a result, conventional resistors can obtain good characteristics with α (nonlinear index) of 20 or more in a certain current range (for example, 100 μA ~], A), but from that range The nonlinear index was considerably low in the outlying f′C region.Furthermore, in addition to this problem, the metal component B1 of 31203, which is the main component of the additive, has a Clark number of 2 There is also the problem of poor quality.

Purpose of the Invention The present invention was made against this background.
The aim is to provide a voltage nonlinear resistor that can carefully suppress the content of Bi2O3 among additive components and improve various device characteristics such as nonlinear characteristics.

Summary of the Invention The present invention is characterized in that zinc oxide (ZnO) is used as a generating component, and zinc oxide (MnO□), antimony oxide (sb, 03), and chromium oxide (ar2o, )% m
A first component containing nickel oxide (NiOl), bismuth oxide (Bi203+) as an additive component, and lead oxide (pbo).
and antimony oxide (Sb, osl and chromium oxide (0r)
20.1+, zinc oxide (ZnO), cobalt oxide (C
o203) and a second component obtained by mixing and calcining one or more of manganese oxide (Mn 02 ) and sintering.

EXAMPLES Below, examples of the present invention will be described, and characteristics of a resistor of a VC5 example will be explained with reference to the drawings.

The voltage nonlinear resistor according to the embodiment of the present invention is made of ZnO97
, 97 molar ratio, B12030.03 molar ratio, MnO20
, 5 mo, I+/%, Sb2 Os 0.5 mole, 0
PPb0 is added to the first component, which is weighed and mixed so that r203 is 0.5 molar and N1o is 0.5 molar.
A second component obtained by calcining a mixed powder containing 1Or20, sb, and o in a molar ratio of 4:1:1 is mixed so that the content ratio of the second component to the whole is 2 parts by weight. This is achieved by sintering.

To describe a specific example of manufacturing such a resistor, first, a predetermined amount of each powder of PbO, Or, and 03.5B2O was weighed in the above proportions, and the weighed powder was mixed in a centrifugal ball mill. Temperature 1000℃ in rear alumina pot
The resultant calcined powder is pulverized in a centrifugal ball mill to obtain a reaction product, which is the second component. On the other hand, ZnO5
Bi□03, N:1. O, Mno2. sb,o,,C
Each powder of r20B is weighed in the above proportions, and the above reaction product is added thereto in two parts, thoroughly mixed in a 70-pound rotary ball mill, and formed into a disk shape.

Next, the molded body was fired in nitrogen atmosphere at a humidity of 1130"C for 6 hours, and the 1II11 joint surfaces of the obtained sintered body were polished, Ag electrodes were applied to both end faces, and heat treatment was performed at a temperature of 590"C for 1 hour. Thus, an acupuncture nonlinear resistor is obtained.

By calcining the mixture of pbo, 5b2o, and Cr203, a reactant containing pyrochlore crystals as a main component can be obtained. To investigate this, we performed Xa diffraction on the above calcined powder, and found that the X-ray diffraction pattern was
It was as shown in the figure. This shows that the main component of the reactant is pyrochlore crystals.

Next, we compared the reciprocal characteristics of the voltage nonlinear resistor (this will be referred to as resistor A) prepared as described above and a conventional resistor whose main additive is Bi2O. Regarding the results, Figure 2 shows the horizontal axis as current and the vertical axis as V.
A graph showing the fc relaxation pressure-current characteristics with 'C, 'lt pressure, Figure 3 shows the heat treatment temperature and ■ 1 m before and after heat treatment.
A graph showing the relationship between A/I, cicada, and the rate of change of α, with the horizontal axis representing the heat treatment temperature and the vertical axis representing the six rates of change.
FIG. 4 is a graph showing the relationship between the pressure change rate (ΔV1mA/vlmA') and the pulse'g flow value. In FIGS. 2 to 4, 1 and 2 indicate the properties of the resistor A and the conventional resistor, respectively, ]a is the pressure at both ends in the example,
α is V (v
Suppose that a reverse pressure of l is generated, then V α and k=
In general, Q is often used when a current in the range of 1 mA to ] mA is applied, and in the following, values in this range are adopted.

First, looking at FIG. 2, the slope of curve 2 becomes smaller than the slope of curve 2 in the microcurrent region and the large current region. Here, α increases as the slope of the curve in Figure 2 decreases, so in the microcurrent region and large current region, α of resistor A is larger than that of the conventional resistor, resulting in nonlinear characteristics. It is understood that it is excellent. Also, looking at Figure 3, in the conventional resistor, V1
Both mA/di and α decrease rapidly as the temperature increases when the heat treatment width is higher than around 500°C, and a decrease in characteristics is observed.
It can be seen that both V l mA /111117 and α hardly change due to heat treatment, and the characteristics do not deteriorate. The curve indicated by 1' in FIG. 3 will be described later. Please refer to Figure 4 in history.
t, IE+l/7"++IC1 day;-'l÷aIA'2
N, 纂4ノ+赞某mon rMnzzτa＾, f-pe≦zuul
→L; For those without NiO, the degree of decrease in voltage change rate is large with respect to increase in pulse current, but for resistor A, the degree of decrease is smaller than that for resistor A that does not include NiO. Like this N
By adding iO, it is possible to suppress the degree of decrease in voltage change rate with respect to increase in pulse current.

Figure 5 shows how α and the rate of voltage change after pulse application (△V1mA/?1mA) change when the content ratio of NiO (relative to the first component) is changed in this example. The solid lines A and B are characteristic curves showing the voltage change rate and the change in α after the application of an 8×20 μs pulse, respectively. Furthermore, the content ratios of other non-containing components are fixed. From this result, in order to obtain good properties, it is essential that NiO be contained in a content ratio of 0.1 to 5 mol. Also, MnO,,sb,o,,
Similar measurements were made for 0r203 and Gyoji, and it was found that in order to obtain good properties, each must be contained in a content ratio of 0.1 to 5 moles (relative to the first component). I found out something. The same 11 applies to the reaction product.
When 1111 pairs were tested, it was found that in order to obtain good properties, it is necessary to contain the content at a content ratio of 0.2 to 20% by weight (relative to the total weight).

Regarding the blending ratio of the above reaction products, Pb0%5b2
Any material may be used as long as it forms pyrochlore crystals containing 0s, and is not limited to the blending ratio shown in the examples.

In addition, its composition V is PbO1sb, o, , gb,
In addition to the combination of o,, Orb o3, PbO and sb
, o3, 0r103, ZnO100203%MnO
A similar effect can be obtained if it is combined with at least one of the two. The calcination temperature and calcination time in the calcination step to obtain the above reaction product were each 800 m
It is desirable that the milk girth is ~j100''C, 1 to 10 hours.The reason is that if the calcination temperature is lower than 800'C or the calcination time is shorter than 1 hour, the reaction will not be sufficiently carried out. Furthermore, if the calcination temperature is higher than 1100'C or the calcination time is longer than 10 hours, the degree of 4Mi B in PbO will increase and the nonlinear characteristics will deteriorate.

The firing temperature and firing time in the firing step after mixing the first component and the second component are preferably 950 to 13501C and 1 to 20 hours, respectively. The reason is that if the firing temperature is lower than 950'C or the firing time is shorter than 1 hour, a dense and uniform sintered body will be produced (4), and if the firing temperature is lower than 1350'C, , or baking time is 2
This is because if the time is longer than 0 hours, the degree of volatilization of pbo, Bi, O, and the like near the surface increases, resulting in poor nonlinear characteristics.

Here Bi2. Regarding the role of O, Figure 6 shows the relationship between the firing rate v in the firing process after mixing the first component and the second component, and α and 91mA/1run.
The results of the investigation are shown for cases in which Bi2O3 is added and cases in which Bi2O3 is not added. The solid line 3.4 indicates -V l m in// when 0.03 mol of Bi2O3 is added, respectively.

The solid lines 5.6 indicate the changes in Bi and 03, respectively.
The figure shows the change in Vlm input/mJp and the change in α for the case where the temperature is not cooled. In this case, the other additive components of the resistor are the same as those of resistor A. As is clear from the figure, the optimum firing temperature range can be expanded by adding trace amounts of Bi and O. And optimal 17゛
'' ゛ --- In order to obtain the effect of broadening the firing temperature, Bi,
It is necessary that the content ratio of 03 is 0.014 or more. The reason for praying for such an effect is Bi and O.

This is thought to be due to the addition of the above-mentioned reaction product in combination. - As the content ratio of Bi2O increases, the rate of decrease in α after heat treatment becomes large and the degree of decrease is said to be the case with joists whose heat treatment temperature is high. Fig. 3 shows the rate of change of α when 0.1 mol tI)6\ of Bi, O, is added, and this solid line 1' and the solid line 1' in the same figure
(Bi, 0.03% addition), Bi,
Bi, O,
The rate of decrease in α is greater than that in which 0.03 molar amount of is added. From the ratio between the solid line 1' and the solid line 2 (conventional resistor), it can be seen that the one in which Bi, 03 is added by 01 molar percentage has better characteristics than the conventional resistor, but Bi, O.

If the content exceeds 0.01 molar ratio, the properties will approach those of conventional products and the effect will be lost. Therefore, Bi
, 03 needs to be in the range of 0.01 to 0.1 molar ratio.

Further, the heat treatment temperature of the sintered body is preferably 500 to 850°C, and if it is lower than 500°C, the life characteristics will be poor, and if it is lower than 850°C, the nonlinear characteristics will be worse.

In the above example, a centrifugal ball mill and an aluminium pot were used to manufacture the resistor, but the type of equipment (4)
may be anything that meets the purpose, and is not limited to this.

Effects of the Invention As described above, according to the present invention, PbO5sb2o is used instead of multiple Bi2O3 as the main component of the additive.

A reaction product whose main component is pyrochlore crystal containing Mn 02, sb, o, 0r
Since the first component includes No. 203 and NiO as the additive component, good characteristics can be obtained while suppressing Bi and O to trace amounts. Moreover, its characteristics are Bi,
This is better than the conventional resistor which had 03 as the main component of the additive. In other words, compared to conventional voltage nonlinear resistors in which B1□0B is generously added, the drop in hunting characteristics due to heat treatment after sintering is small, and the normal temperature range (
By performing heat treatment at a temperature of 400°C (0 to 900°C), the electrical properties hardly deteriorate.As a result, the nonlinear index in the microcurrent region and the Tairyu flow region is larger than that of conventional products, and the microcurrent range is Since the non-linear index in the area is large, the leakage current at the time of energization is small.Furthermore, the increase in decay current due to long-term energization is small, and a long-life surge absorbing element can be obtained.And the second component, reaction generation By adding a combination of Bi, O, and Bi, it is possible to widen the firing range and facilitate control in the manufacturing process.Also, the Clark number of Bi, O, (Bi, 2 x 10-' ) is less expensive in terms of resources compared to the case where a large amount of Clark number 1.5 x LO-' l ', Sb (Clark number is 5 This is because although the t is small, the content ratio is not as large as in the conventional case B1.In addition to the above effects,
Reaction products containing pbo and trace amounts of Bi.

0, PbO, Bi2
There is almost no volatilization of O3, which is good in terms of occupational health and environment.

[Brief explanation of drawings]

Figure 1 is an X-ray diffraction diagram of an example of the reaction product used in the present invention, Figure 2 is a voltage-44 current characteristic diagram of a voltage nonlinear resistor,
Figure 3 shows the heat treatment of a voltage non-linear resistor.
A graph showing changes in 1mA /rrtrn and α, Fig. 4.6 Voltage nonlinear resistor pulse 1] ε A graph showing the rate of pressure change when pulses are applied to the current value, Fig. 5 shows voltage nonlinear resistance Figure 6 is a graph showing the non-linear characteristics of the 1U pressure surface linear resistance against the firing temperature. 00 400 (V) 200 Sochiri Eihito (0C) @5L (A) Fig. 4 (%) Pulse @Ryuaicho (KA)

Claims (1)

[Claims] (],) Manganese oxide 0.1 to 5 moles, antimony oxide 0.1 to 5 moles qb, chromium mide 0.1 to 5 moles,
Nickel halide 0.1-5 moles, bismuth oxide 0.01
~0.1 molar ratio, the balance is obtained by calcining a mixture consisting of one or more of chromium oxide, zinc oxide, cobalt oxide and manganese oxide, and lead oxide and antimony oxide to the first component consisting of zinc oxide. 1. A voltage nonlinear resistor, characterized in that the second component is mixed and sintered so that the proportion of the second component to the whole becomes 0.2 to 20 times.