JPS58153302A - Method of producing 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] [Technical Field of the Invention] The present invention relates to a method for manufacturing a non-linear resistor whose main components are zinc oxide or zinc oxide and magnesium oxide, and whose sintered body itself has non-linear resistance characteristics. be.

[Technical background and problems of the invention]

A nonlinear resistor is generally called a varistor, and its excellent nonlinear voltage-current characteristics are utilized to make it widely used in lightning arresters and surge absorbers for the purpose of voltage stabilization or surge absorption. A typical example is the recently developed zinc oxide varistor. It is mainly composed of zinc oxide or zinc oxide and magnesium oxide, to which small amounts of oxides such as bismuth, antimony, cobalt, manganese, and chromium are added, mixed, granulated, molded, and then fired at high temperature in air. It is constructed by attaching electrodes to the sintered body. Its non-linear resistance characteristics are very good.
The sintered body consists of zinc oxide particles and a grain boundary layer formed around them by additives, and the excellent nonlinear resistance characteristics are thought to be due to the interface between the zinc oxide particles and the grain boundary layer. It is being

However, when these nonlinear resistors are industrially mass-produced, they not only cause a decrease in nonlinear resistance characteristics and variations in their characteristics, but also other performance decreases such as energized life and discharge durability. There was a problem.

The reason for this is that the amount of oxides such as bismuth, antimony, cobalt, manganese, and chromium, which are added to the main component zinc oxide or zinc oxide and magnesium oxide and form grain boundary holes, is extremely small. . (The total amount of additives is less than 10%, and depending on each component, it is less than 0.5%.) Therefore, it goes without saying that the method of mixing the main components and additives is important, but on the other hand, from the reaction mechanism point of view, the physical properties of the starting materials Variations, especially spinel layer formation in grain boundaries ((ZnMg),
8b, O□ or Zn8b, O.] It is thought that the physical properties based on the composition of antimony oxide itself, which plays a major role, have a particularly large influence. Generally commercially available antimony oxide has a crystal form of 8b, O, due to the manufacturing method, as shown in the X-ray diffraction lines 121 and 222 shown in Figure 1.
As can be inferred from the above, it is a mixed system of orthorhombic and equiaxed crystals.
Usually, 1 to 2% of Anne, 8b, 04 and 8b Os are mixed.

In this way, the starting raw material for antimony oxide contains a mixture of crystal forms of sb, o, sb, o, sb, o,
When using a material that contains substances such as these, the reaction mechanism is subtly affected depending on the mixture and mixing ratio, and this is directly linked to the stability of the spinel layer that is finally formed, that is, the stability of the characteristics of the nonlinear resistor. it is conceivable that.

[Purpose of the invention]

The present invention is based on the above points, and uses antimony trioxide (8btOs) having a composition of antimony as a starting material.
) It is an object of the present invention to provide a method for manufacturing a nonlinear resistor having stable nonlinear resistance characteristics by using a material with controlled purity, crystal shape, and grain size.

[Summary of the invention]

The present invention provides a method for manufacturing a voltage nonlinear resistor, which comprises adding and heating at least one metal oxide to zinc oxide or zinc oxide and magnesium oxide as main components, molding the mixture, and then firing it. The composition of antimony oxide as the metal oxide is a+) purity of antimono trioxide of 99.0 S or more, b) X1ll of antimono trioxide [
The intensity peak ratio of diffraction line 121 (orthorhombic form) and diffraction line 122 (equiaxed form) obtained by diffraction (diffraction life 121 intensity peak ratio/intensity peak of diffraction line 122) is 0.3 or lessC) Average particle size Its characteristic is that it is 0.5# or less.

[Embodiments of the invention]

Next, embodiments of the present invention will be described with reference to the drawings.

For example, 80 mol of ZnO and 2 mol % of at least four metal oxides, such as Mg014mol, B2O,
, 8b, O, L5 mo sp-, C001, 1 mo A/
%, cr, o.

0.54&lG1Mn00.5-%le%,'elol
o, 4% le% (to weigh in D proportion.

This pigeon house antimony oxide is antimony trioxide sb, Os
M station is 99. The crystal forms of S, sb, and o were those in the equiaxed crystal form containing almost no orthorhombic crystals, as shown by the 121st stroke line in Figure 2, and those with an average grain size of 2-5μ. The weighed oxide is placed in a ball mill, for example, and mixed with deionized water by operating the ball for 24 hours. The mixture is dried, and then placed in an electric F for calcining.

The appropriate calcination temperature is, for example, 900° for 2 hours.

When calcined, the oxide becomes lumpy, so it is crushed into fine particles. For example, polyvinyl alcohol is mixed with the oxide before pulverization in a weight ratio of, for example, 1/100 to the oxide.

A ball mill is used for fine grinding. (K) The finely ground oxide and polyvinyl alcohol are substantially homogeneously mixed.

Next, the oxide is placed in a granulating device, such as a spray dryer, to form spherical aggregates having a particle size of, for example, 100 to 300 kilometres.

This powdery mixture is pressed to give a diameter of, for example, 10Qm.
, formed into a disk with a thickness of 25 mm.

This molded product is placed in an electric furnace and fired. The firing temperature is, for example, 1300° C. and 6 hours is suitable for 1 hour.

After firing, the disc-shaped fired product shrinks before firing, but has a nearly homogeneous texture and consistency.

Next, both sides of the disc-shaped fired product are lightly polished to expose the fired product, and this exposure flK is thermally sprayed with, for example, aluminum.
Form the electrodes and form the nonlinear resistor.The electrical characteristics of the nonlinear resistor thus obtained are shown in 11.
This is shown in Figures 3 and 4.

FIG. 3 shows the change in leakage current during running when a voltage of V1m (voltage between terminals when 1 mA is applied to the non-linear resistor) is applied to the non-linear resistor in a constant temperature bath at 90°C.

Further, Figure 114 shows the rate of change (ΔV/V, mA) in the values of V and V when the current was applied up to 100 times by 101 people.

In each figure, Yoshimu shows the characteristics of a conventional nonlinear resistor,
Chain line farming is the real deal! The characteristics of the nonlinear resistor according to J1 are shown.

As is clear from FIG. 3, the nonlinear resistor according to the present invention has I! Compared to conventional non-linear resistors, the change in leakage current with respect to applied voltage is significantly improved, in other words, the life ** is extended to #cjL. Furthermore, as is clear from FIG. 4, the non-linear resistor according to the present invention has significantly improved impact current withstand characteristics as compared to the conventional non-linear resistor.

The excellent properties shown in Figures 3 and 4 can be obtained by controlling the physical properties of the starting materials of sb, o, and the spinel in the range that is produced by reacting with other additives. It seems that the layer is stabilized and equalized.

As a result of various studies conducted by the inventors, the stability of the characteristics is sb, o
, purity of 9% or higher, X11 diffraction lines 121 and 22
It was found that good results were obtained when the diffraction intensity peak ratio of No. 2 was 9-0.3 or less and the average particle size was 5 μm or less. Further, according to microstructural analysis, differences in the physical properties of the starting material of antimony oxide cause significant differences in the amount and thickness of the produced spinel layer, and it is possible to get a glimpse of the difference in the reaction mechanism.

In addition, the differences in nine characteristics shown in Figures 3 and 4 are as follows.
As shown in the figure, V, mA%In (
The magnitude of variation in basic characteristics such as resistance leakage current (resistance leakage current) C (capacitance), etc. can also be seen. ・As shown in curve 8 in Figure 5, curves that deviate from the control range by, for example, 3 or more, appear in 9 cases. 10
Tuto is defective.

If it is judged as 9, the standard variation when the physical properties of the antimony oxide starting material are not regulated is represented by the DIII line, and it also includes the risk probability of becoming a defective 1-self line.

According to the present invention, the standard variation is represented by C11ll, and falls within the 4DIll line in the worst case], and it can be seen that the occurrence of defective lots can be suppressed.

The material composition and counterfeiting equipment method shown in the above embodiments are not necessarily limited to the above embodiments as long as they contain zinc oxide or zinc oxide and magnesium oxide as main components and can provide varistor properties.

〔Effect of the invention〕

As explained above, according to the present invention, 11! By controlling the physical properties of the starting material of anti-monocarbons, the properties can be stabilized and a non-linear resistor can be provided.

[Brief explanation of the drawing]

The s1 factor is an explanatory diagram showing the X-ray diffraction diagram of the conventional anti-septane oxide composition, Figure 112 is the X-ray diffraction diagram of the antimony oxide composition of one embodiment of the present invention, and Figure 3 is the X-ray diffraction diagram of the antimony oxide composition of one embodiment of the present invention. FIG. 4 is a characteristic diagram showing the relationship between peak soldering time and leakage current of such a voltage non-linear resistor, FIG. 4 is a characteristic diagram showing shock current withstand capability, and FIG. 5 is a characteristic diagram showing variations in varistor characteristics. (7317) Agent: Patent Attorney Noriyuki Chika (
(and 1 other person) Figure 3 Responsibility Simple review (N) Figure 4 Tomo L (n 臥) Gurujinjin eμrocontinuously soft (times) Figure 5 Procedural amendment (voluntary) 1. Incident display voltage non-linear resistor OII! Method 3, Relationship with the case of the person making the amendment Patent applicant (307) Tokyo Shibaura'Seiki Co., Ltd. 4, Yokoto 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100 1, Mei-Sho Kinbun 2, I! gl lfl & Description of amendments Summary 1, Name of the invention Method for producing voltage non-direction antibody In the method for manufacturing a voltage non-linear resistor, in which saponified metals containing metals are added and mixed, the mixture is molded, and then fired, the antimony oxide as the capsule a sulfide is a) trioxide yf * yoj 1 degree 910- or more b) Diffraction line 1 obtained by Athymon trioxide Ox@Omoori
21 (orthorhombic) and diffraction lines 222 (equiaxed Jli
) o**He-1 ratio (llN? 4 y121 O@
g Peter/Il#r Life 222t) @R Peter) A method for manufacturing a voltage non-direct resistor O that satisfies the requirements 03 Qin 1 λ Derivation - O detailed ll@ [Technical field of the invention] The present invention relates to a method for manufacturing a nonlinear resistor whose main components are zinc oxide or saponified zinc and saponified magnesium and whose sintered body itself has nonlinear resistance characteristics. [Contact Background and Problems of the Invention] Nonlinear resistors are generally called varistors, and their excellent nonlinear voltage-current characteristics are used to stabilize voltage.
is widely used in the lightning arrester Yasajia Apnopa for the purpose of absorbing surges. A typical example is zinc oxide, which has been developed in recent years (there is a risk).This is mainly composed of saponified zinc or saponified zinc and saponified magnesium, and small amounts of bismuth, a/thi, ly, cobalt, manganese,
After adding oxides such as chromium, mixing, granulating and molding, it is fired at high temperature in the air, and an electric bridge is attached to the sintered body.The non-linear resistance characteristics are extremely high. The sintered body consists of a grain boundary layer formed by saponified zinc particles and their additives, and the excellent non-linear resistance characteristics are attributed to the boundaries between the saponified zinc particles and the grain boundary layer. It is considered. However, if these non-linear resistors are manufactured in an engineered manner, they will not only result in a decrease in non-linear resistance characteristics (or buffing of the characteristics), but will also cause other performance deteriorations such as 1lIE life and discharge resistance. There was a problem with that. The reason for this is that the amount of oxides such as bismuth, antimony, cobalt, manganese, and chromium, which are added to the main components of oxidation or zinc oxide and magnesium oxide and form grain boundary layers, is extremely small. be. (The additives as a whole are less than 10'1, and depending on each component, it is less than 0.591.) Therefore, it goes without saying that the method of combining the main ingredients and additives is important, but on the other hand, from the viewpoint of the reaction mechanism, it is important to Spinel layer formation ((ZnMg) with variation in physical properties and good adhesion
It is thought that the physical properties based on the fiber composition of anti-4 oxide itself, which plays a major role in the process, have a particularly large influence. Generally commercially available antimono oxides are s
The crystal forms of 8b, 0, and 8b, as can be inferred from the Xfli times H5 in 12t diagram shown in Figure 111, are a mixed system of orthorhombic and equiaxed crystals. Y8b, 0.
Normally, 1-214 people are added. At this time, the starting raw material for antimony oxide [8b, Os is crystallized].
b, 04, 8b, 0. When using spinel mixed with the same amount, the reaction mechanism may be slightly affected depending on the mixture and mixing ratio, and the stability of the spinel layer that is finally formed may be affected.
In other words, it is thought that this is directly connected to the characteristic stability of the nonlinear resistor. [Object of the Invention] The present invention was developed in view of the above points, and uses antimony trioxide (8b-s) having an antimony oxide composition as a starting material.
The object of the present invention is to provide a method for manufacturing a non-linear resistor having stable non-linear resistance characteristics by controlling the purity and *crystal form 9 grain size and using t. [Summary of the Invention] The present invention provides saponification I! The main ingredients are lead or zinc oxide and magnesium oxide, and at least one kind of gold.
*In the method for manufacturing a voltage nonlinear resistor in which a compound is added, the mixture is molded, and pre-fired, the composition of antimony oxide as a key metal oxide is a) purity of antimono trioxide of 99, O coefficient or higher. , b) x1 of antimony trioxide
Strong electric peak ratio of I-fold in 121 (orthorhombic form) and diffraction line 222 (equiaxed crystal form) obtained by one diffraction (strong electric peak of diffraction line 121/1i of diffraction line y222)
! 1 degree peak) is 0.3 or less C) Average particle size 511j & 4
The following is a characteristic of the GA theory of the invention, which is a characteristic. For example, 80 moles of Zfio and at least one kind of meeting all! Compound % fill, ttfMgo 14 moA [
, Bi, 0.2% Lu, 8b*Oa 1.54 w arrogance, Coo 1.1 mol % ”l0IQ, 5 mol-1M
, aOQ, 5-t-ru1. iFe, O, Q, 44%
Weigh in O proportion. In this case, antimono oxide is antimony trioxide 8bmOs
14K is 99. s- or higher, 8b, o, o crystal tf4
ki, as shown by the 121-fold line in Fig. 2, which contains almost no orthorhombic crystals, and those with an average grain size of 2.5μ! Boil, weigh, and place the nonaoxide tube in a ball mill, for example, and mix with deionized water by -MK% by running the ball mill for 24 hours. The mixture is dried and calcined in an electric furnace. The appropriate calcination temperature is, for example, 900° C. for 2 hours. When calcined, the oxide becomes solid, so it is crushed into fine particles. Oxidized K before pulverization, such as polyvinyl alcohol, is added in a weight ratio of, for example, 11/100 to the oxide. A ball mill is used for fine grinding. As a result, the pulverized oxide and polyvinyl alcohol are substantially homogeneous.
mixed. The oxide is then placed in a granulating device, such as a spray dryer, to form spherical agglomerates having a particle size of, for example, 100 to 300 tons. This powder bed-like mixture is pressed and formed into a disk having a diameter of 100 mm and a thickness of 25 mm, for example. This molded product is placed in an electric furnace and fired. The firing temperature is, for example, 1300°C, and 6 hours is appropriate for time 14. ◇The disc-shaped fired product after firing shrinks during firing, but is almost homogeneous.
It has density. Next, both m of the disc-shaped fired product are lightly polished to expose the fired product. This exposure (TiK, for example, aluminum is thermally sprayed to form electrodes and a non-linear resistor). The electrical characteristics of the nonlinear resistor obtained by
Shown in Figure 3 and Figure @4. Figure 113 shows the change in leakage current when a voltage of 85 V, mA (voltage between terminals when lnaA is applied to the non-linear resistor) is applied to the non-linear resistor in a constant temperature bath at 90°C. Further, 1141m indicates the rate of change (ΔV/V1mA) in the value of aAO when the current of IOK is applied up to 100 times. In each figure:), chain-1 shows the characteristics of the conventional non-linear resistor, and chain-1 shows the characteristics of the non-linear resistor according to the present invention. Compared to conventional non-linear resistors, linear resistors have a significantly improved change in leakage current to IiI voltage.
114! ! has been improved. Furthermore, as can be clearly seen from FIG. 4, the non-linear resistor according to the present invention has significantly improved shock current withstand characteristics as compared to the conventional non-linear resistor. The excellent properties shown in Figures 3 and 4 can be obtained by controlling the physical properties of the starting materials for sb and os, and by controlling the physical properties of the starting materials for sb and os, spinel layers are formed in the grain boundaries that form when they react with other additives. appears to be stabilizing. As a result of various studies by the present inventors, it was found that the characteristics were stable81)v
Os no N IJj more than 99%, X*a fold 9
(It was found that the results were good when using 7121 and 7121 with an average particle size of 5μ or less. Also, according to the microstructure analysis, the difference in the physical properties of the starting material of the aluminized antimono There are significant differences in the amount, zero thickness, and iC, and we can get a glimpse of the difference in the reaction mechanism. The 14 characteristics of time are v, mm,
This can also be seen in the magnitude of the variation in basic characteristics such as In (resistance leakage 1tfI &) C (electrostatic transfer). -If a deviation of, for example, 30 degrees or more from the bud coral width appears in the two curves in Figure 5, it is determined that the lot is defective. The standard variation of is represented by the D-line,
The risk probability of falling into one defective curve was also about 10 tatami. According to the present invention, the standard variation is represented by the C curve, and even in the worst case, it falls within the 9 curve, and it can be seen that the occurrence of defective lofts can be completely eliminated. The material composition, manufacturing equipment, and method shown in the above examples are limited to the above examples as long as the main ingredients are zinc oxide or zinc oxide and magnesium oxide, and varistor characteristics can be obtained. It's nothing. [Effects of the Invention] According to the IIK present invention explained above, oxidized antipropylene O
* By controlling the physical properties of the raw material, it is possible to provide a non-linear resistor with stabilized characteristics. 4. Brief explanation of the drawings Figure 111 is an explanatory diagram showing the x4 diffraction diagram of the conventional antimony oxide composition. , 112 is an XlitgI diagram of the antimony oxide composition according to an embodiment of the present invention, and 113 is a characteristic diagram showing the relationship between d4 time and leakage current of a positive nonlinear resistor according to an embodiment of the present invention. FIG. 4 is a characteristic diagram showing impact current resistance, and FIG. 5 is a characteristic diagram showing variations in varistor characteristics.

Claims (1)

[Claims] A voltage nonlinear resistor whose main components are zinc oxide or saponified zinc and magnesium oxide, which are heated with the addition of a metal oxide containing at least antimony oxide, and which is molded and then fired. According to the manufacturing method, the gold [1g111
Antimony oxide as a compound has a) purity of antimony trioxide of 99.0- or higher b) diffraction line 1 obtained by X-ray diffraction of antimony trioxide
The intensity peak ratio of 21 (orthorhombic form) and diffraction line 122 (equiaxed form) (intensity peak of diffraction line 121/@intensity peak of diffraction line 122) is 0.3 or less C) Average grain 11O, 5μ or less A method for manufacturing a voltage nonlinear resistor that satisfies the following three conditions.