JP2608626B2 - Method of manufacturing voltage non-linear resistor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a voltage non-linear resistor mainly composed of zinc oxide.

(Prior art) Conventionally, zinc oxide (ZnO) as a main component and Bi ₂ O ₃ , Sb
Low antibodies containing small amounts of metal oxides such as ₂ O ₃ , SiO ₂ , Co ₂ O ₃ , and MnO ₂ as secondary components are widely known to exhibit excellent voltage non-linearity. It is used for lightning arresters.

Conventionally, borosilicon bismuth glass frit containing silver is
JP-A-56-152209, JP-A-59-94402 and JP-B-52
-40440 and the like.

(Problems to be Solved by the Invention) However, the voltage non-linear resistor manufactured from bismuth borosilicate glass frit containing silver has large variations in element characteristics for each manufacturing lot, and also has a surge withstand characteristic and a service life. There was a problem that the characteristics were also insufficient.

(Means for Solving the Problems) A first object of the present invention is to improve surge withstand characteristics.

 A second object of the present invention is to reduce fluctuations in device characteristics.

 A third object of the present invention is to improve the charging life characteristics.

The present invention relates to a method for manufacturing a voltage non-linear resistor comprising zinc oxide as a main component and at least bismuth oxide and bismuth borosilicate in which silver oxide is dissolved as a solid solution as an additive component, wherein silicon oxide (SiO ₂ ) is 5 to 15 wt%. , Boron oxide (B ₂ O ₃ )
110 wt.%, Include ₍₂ O Ag) 10~35wt% silver oxide, and the weight ratio of boron oxide silver oxide _{(B 2 O 3 / Ag 2} O) is from 0.07 to 1.0, and an average particle size A method for manufacturing a voltage non-linear resistor, comprising mixing bismuth borosilicate glass frit having a size of 2 to 20 μm with respect to the total amount of a zinc oxide raw material and an additive metal oxide component in an amount of 0.01 to 0.2 wt%. .

The particle size of the glass frit is 2-20 μm, especially 5-10 μm
m is preferred.

Heretofore, the addition of glass frit was limited only by the amount of addition and the amount of addition for each composition of the frit. The inventor of the present invention has found that the composition ratio of each component in the frit, especially boron and silver, greatly affects the element characteristics, for example, the lightning surge withstand capability characteristics, and the particle size of the frit greatly varies depending on the grinding conditions of the glass frit. The inventors have found that the present invention is strongly involved in variations in device characteristics, and have completed the present invention.

If the amount of glass frit added is less than 0.01 wt% with respect to the total amount of the zinc oxide raw material and the added metal oxide component, there is no property improving effect, and if it exceeds 0.2 wt%, the lightning surge change rate deteriorates.

In the composition of the glass frit, the compounding amount of silicon oxide is
If the content is less than 5 wt%, vitrification becomes difficult, the glass frit partially crystallizes, and the reaction with other components of the device becomes non-uniform. The reactivity decreases.

If the amount of boron oxide is less than 1% by weight, the charging life and moisture absorption resistance of the device are reduced, and if it exceeds 1% by weight, the rate of change of _V1mA after application of a lightning surge is deteriorated. 1-5 wt% is more preferred.

If the amount of silver oxide is less than 10% by weight, the flatness in the large current region in the VI characteristic of the device is deteriorated, and if it exceeds 35% by weight, the silver oxide is not uniformly dissolved and vitrification becomes difficult. Therefore, the reaction with other components of the device becomes heterogeneous.

By mixing bismuth oxide into bismuth glass frit, it becomes a low melting glass that is easy to vitrify,
Reactivity with other additives also increases.

When the average particle diameter is less than 2 μm, the characteristics of the device greatly vary, and when the average particle diameter exceeds 20 μm, the service life is deteriorated. 5-
10 μm is more preferred.

If B ₂ O ₃ / Ag ₂ O is less than 0.07, the effect of the addition of boron oxide is extremely reduced and the service life is deteriorated. If it exceeds 1.0, the effect of the addition of silver oxide is reduced and the lightning surge change rate is deteriorated.

To manufacture a voltage non-linear resistor, a zinc oxide raw material adjusted to a predetermined particle size and bismuth oxide, cobalt oxide, manganese oxide, antimony oxide, chromium oxide, silicon oxide, nickel oxide, aluminum oxide adjusted to a predetermined particle size are used. And a predetermined amount of bismuth borosilicate glass frit containing silver oxide in the present invention. Normal,
Bi ₂ O ₃ 0.5 to 1.0 so that the total amount with ZnO is 100 mol%.
Mol%, Co ₃ O ₄ 0.5~1.0 mol%, MnO ₂ 0.5 to 1.0 mol%, S
b ₂ O ₃ 0.5 to 1.0 mol%, Cr ₂ O _{3 0.5~1.0} mol%, NiO0.5~
1.5 mol%, SiO ₂ 1 to 2 mol%, Al ₂ O ₃ 0.001~0.05 mol%
Is added to the zinc oxide raw material as an additional metal oxide component, and in the present invention, the above-mentioned bismuth borosilicate glass containing silver oxide is blended at 0.01 to 0.2 wt%. Next, a predetermined amount of an aqueous polyvinyl alcohol solution or the like is added to the raw material powder and the glass frit, and the mixture is preferably mixed by a disper mill, and then granulated by a spray dryer to obtain a granulated product. After granulation, molding pressure 800
It is molded into a predetermined shape under ~ 1000 kg / cm ² . Then, the molded body is heated at a temperature rise / fall rate of 30 to 70 ° C./hr at 800 to 1000 ° C. for a holding time of 1 hour.
Preliminary firing is performed under the condition of about 5 hours.

In addition, before the preliminary firing, the molded body was heated and cooled at a rate of 10 to 100 ° C / hr.
At 400 to 600 ° C. for a holding time of 1 to 10 hours to scatter and remove the binder. This is called a degreased body.

Next, a side surface high resistance layer is formed on the side surface of the calcined body that has been calcined. A paste for a side surface high resistance layer obtained by adding ethylsulfulose, butyl carbitol, n-butyl acetate, etc. as an organic binder to a predetermined amount of bismuth oxide, antimony oxide, silicon oxide, etc. is calcined to a thickness of 60 to 300 μm. Apply to side of body. The mixture paste may be applied to a molded body or a degreased body. Next, the temperature is raised and lowered at a rate of 40-60.
Main firing is performed at a temperature of 1000C to 1300C, preferably 1100 to 1250C, and a holding time of 3 to 7 hours.

In addition, ethyl cellulose, butyl carbitol, n-butyl acetate, etc., as an organic binder were added to the glass powder, and a glass paste was applied to the side high-resistance layer to a thickness of 100 to 300 μm, and the temperature was raised and lowered in air at a rate of 100 ° C. ~ 200 ℃ / hr, 500 ~
By performing a heat treatment under the conditions of 900 ° C. and a holding time of 0.5 to 10 hours, it is possible to simultaneously form a glass layer.

Then, both end faces of the obtained voltage nonlinear resistor were SiC, Al
Polishing with water or oil with an abrasive equivalent to # 400 to # 2000 such as ₂ O ₃ and diamond. Next, after the polished surface is cleaned, electrodes are provided on both polished end surfaces by, for example, aluminum or the like by, for example, thermal spraying to obtain a voltage non-linear resistor.

(Examples) Examples 1 to 47 and Comparative Examples 1 to 15 Voltage non-linear resistors within and outside the range of the present invention were produced using glass frit shown in the following tables, and various characteristics were measured. The results are shown in Tables 1 to 3.

In the production, Bi ₂ O ₃ 1.0 mol%, Co ₃ O ₄ 0.6 mol%, MnO ₂ 0.5 mol%, Sb ₂ O ₃ 1.0 mol%, Cr ₂ O ₃ 0.5 mol%, NiO1.0 mol%, SiO ₂ Mix the zinc oxide raw material and additives so that 1.5 mol%, Al ³⁺ 50 ppm and the balance are zinc oxide, add 0.1 wt% of bismuth borosilicate glass externally, and form the side high resistance layer as described above. , The main firing,
Each voltage non-linear resistor having a diameter of 47 mm, a height of 22.5 mm, and a varistor voltage V _IA = 5.8 KV was produced.

The non-linear index α in Tables 1 to 3 is V _{1 mA} and V ₁₀₀ μA.
Is derived from the following equation.

I = (V / C) ^α where I: current, V: voltage, C: constant The surge change rate is a waveform of 8 / 20μs, before and after surge application when 30kA current is applied 10 times at 1 minute intervals. V shows the rate of change of _{1 mA} . That is, The electric service life was indicated by a circle with a temperature of 130 ° C. and an electric power application rate of 95% without heat runaway after 1000 hours of the test.

Incidentally, Bi ₂ O ₃ 0.5 to 1.0 mol%, Co ₂ O ₃ 0.5 to 1.0 mol%,
MnO0.5~1.0 mol%, Sb ₂ O ₃ 0.5~1.0 mol%, Cr ₂ O ₃ 0.5~
1.0 mol%, NiO 0.5-1.5 mol%, SiO ₂ 1-2 mol%, Al ₂
Even with a composition in the range of 0.003 to 0.05 mol% of O ₃ and the balance of ZnO, the same results as in the present example were shown by implementing the present invention.

(Effects) As is clear from Tables 1 to 3, according to the present invention, the surge withstand characteristic was improved, the characteristic fluctuation of the element was reduced, and the charging lifetime was improved.

Claims (1)

(57) [Claims] [Claim 1] as a main component zinc oxide, in the manufacturing method of the voltage nonlinear resistor comprising at least bismuth oxide solid solution of silver oxide borosilicate bismuth glass as an additive component, silicon oxide (SiO _2). 5 to 15 wt%, boron oxide (B ₂ O ₃₎
110 wt.%, Include ₍₂ O Ag) 10~35wt% silver oxide, and the weight ratio of boron oxide silver oxide _{(B 2 O 3 / Ag 2} O) is from 0.07 to 1.0, and an average particle size A method of manufacturing a voltage non-linear resistor, comprising mixing bismuth borosilicate glass frit having a size of 2 to 20 μm with respect to a total amount of a zinc oxide raw material and an added metal oxide component in an amount of 0.01 to 0.2 wt%.