JP2001288335A - Insulating spacer, its use and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an insulating spacer improved in a phenomenon which is a problem in conventional insulating spacers that modulus of elasticity is remarkably decreased at temperatures above the glass transition temperature (Tg), having high modulus of elasticity even at temperatures above Tg, having a small deformation against a mechanical loading and excellent in reliability and to provide a method for producing the spacer. SOLUTION: This insulating spacer is characterized in that the spacer is formed by a cured product of an epoxy resin composition comprising a polyfunctional epoxy resin, a specific organosilicon compound, an acid anhydride and an inorganic filler in the insulating spacer insulatively supporting a conductor arranged in a container filled with an insulating gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel insulating spacer and a method for manufacturing the same, and preferably to sulfur hexafluoride (SF).
₆ ) An insulating spacer for insulating and supporting a conductor disposed in a container filled with an insulating gas such as a gas, a method for manufacturing the same, a gas-insulated switchgear using the same, and a gas-insulated conduit.

[0002]

BACKGROUND ART insulating spacer gas insulated equipment is intended to support the high-voltage conductor in the grounding metal container filled with insulating gas such as SF ₆ gas, a structure obtained by blending the filler into the base resin. When SF ₆ is used as an insulating gas, the SF ₆ gas is decomposed by arc discharge or corona discharge, and hydrogen fluoride (HF) is generated. Have been applied. A mixture of an epoxy resin and an acid anhydride is mainly used for the base resin from the viewpoint of mechanical properties, electrical characteristics and casting workability during production, and an alumina is mainly used for the filler from the viewpoint of hydrogen fluoride resistance.

[0003] In recent years, due to the increase in power consumption, difficulty in securing land near the city, and development of underground substation, etc., gas insulated switchgear and gas insulated conduit air transmission lines as transmission and substation equipment have been increased in capacity and compactness. Is required. Therefore,
Insulating spacers applied to these devices are required to have low dielectric constant and high heat resistance. In order to cope with this, to reduce the dielectric constant, as a filler, for example, JP-A-5-15-1
JP-A-46035 and JP-A-9-176288 disclose a method of using a mixture of aluminum fluoride and alumina, and increase the Tg (glass transition temperature) by applying a polyfunctional epoxy resin in order to achieve high heat resistance. Methods and the like are disclosed. Meanwhile, a silica which is known as a low-cost filler of the insulating resin for various electrical equipment, because the resistance to hydrogen fluoride resistance as described above despite the low dielectric constant significantly inferior, SF ₆
Application to devices using gas as an insulating gas has been avoided. However, the price competition by recent economic recession, SF ₆ decomposition gas in these devices the hardly occurs duty post, the application of low-cost insulating spacer silica-filler has begun to be studied. Along with this, there is an increasing trend to improve the performance by actively adopting a silicon compound as a constituent material of the insulating spacer.

[0004]

The insulating spacer disclosed in the above-mentioned publication can obtain relatively high heat resistance by applying a polyfunctional epoxy having a specific epoxy equivalent, but is accompanied by an increase in power transmission capacity. Considering the case where the conductor temperature further increases, it is not always sufficient. In particular, when these insulating spacers exceed Tg, a sudden decrease in elastic modulus and an increase in linear expansion coefficient are caused, and reliability with respect to mechanical strength is impaired.

An object of the present invention is to improve the problem that the elastic modulus suddenly decreases when the temperature exceeds Tg, which is a problem of the conventional insulating spacer, and the elastic modulus is high even at a temperature exceeding Tg, and the mechanical strength is excellent. And a method of manufacturing the same.

[0006]

According to the present invention, there is provided an insulating spacer for insulating and supporting a conductor provided in a container filled with an insulating gas, wherein the insulating spacer comprises a polyfunctional epoxy resin and the following general formula (1): ) Or (2),

[0007]

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[0008]

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(R is an organic group containing a functional group which causes an addition reaction with an acid anhydride, n is 0 to 3 and X is H, CH ₃ or C ₂ H ₅ ) , A cured product of an epoxy resin composition containing an acid anhydride and an inorganic filler.

The epoxy resin used in the present invention has both the heat resistance required as an insulating spacer and the fact that the insulating spacer is made by casting, so that it has low viscosity at the temperature at the time of casting and good workability. For epoxy equivalent of 150 ~
250 polyfunctional epoxy resins are preferred. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol A / F type epoxy resin, alicyclic epoxy resin, and the like, or a mixture thereof.

According to the present invention, there is provided a method of manufacturing an insulating spacer for insulating and supporting a conductor provided in a container filled with an insulating gas, wherein the insulating spacer is represented by the following general formula (3) or (4).

[0012]

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[0013]

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An organosilicon compound (where R is an organic group containing a functional group which causes an addition reaction with the acid anhydride,
And R ¹ and R ² are a methyl group or an ethyl group)
And, a step of producing an organosilicon mixed solution containing water and a hydrolysis catalyst, and a step of producing an epoxy resin mixed solution in which an epoxy resin is added to the mixed solution and heated and mixed,
An acid anhydride and an inorganic filler are added to and mixed with the epoxy resin mixed solution, and then the mixed solution is poured into a desired mold and cured by heating.

That is, an organosilicon compound represented by the general formula (3) or (4) (where R is an organic group containing a functional group that causes an addition reaction with the acid anhydride, and R ¹
And R ² is a methyl group or an ethyl group), and the mixture containing the polyfunctional epoxy resin and water is subjected to a heat treatment at preferably 60 to 160 ° C. for 1 to 10 hours. Here, the amount of water is 3 to
A 0.02 volume is preferred. The polyfunctional epoxy resin produced in this manner is combined with the general formula (1) or (2)
An acid anhydride is added as a curing agent to the above mixture, and an inorganic filler is further added to improve the mechanical strength and lower the coefficient of linear expansion.

The acid anhydride used in the present invention is not particularly limited as long as it is an acid anhydride known as a curing agent for epoxy resins. Such acid anhydrides include hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, nadic anhydride, methylnadic anhydride, succinic anhydride, octadecylsuccinic anhydride And maleic anhydride, and these may be used alone or as a mixture.

As the inorganic filler, known materials used for epoxy resins are appropriately selected and used, for example, crystalline silica, fused silica, alumina, aluminum fluoride, magnesium oxide, calcium carbonate, magnesium carbonate, dolomite. , Boron nitride, aluminum hydroxide, magnesium hydroxide and the like, and crystalline silica, fused silica, alumina and the like are preferable from the viewpoint of cost and cured product characteristics.

Further, various auxiliaries are added as needed to improve the properties as a casting resin. For example, a flexible agent, a curing accelerator, a coupling agent, a coloring agent, an antioxidant and the like are appropriately added. Applied.

[0019]

According to the present invention, elasticity in a temperature range exceeding Tg is obtained.
It is considered that the reason why the rate is hard to decrease is as follows.
available. Polyfunctional epoxy resin, organosilicon compound
However, it has a functional group that causes an addition reaction with acid anhydride)
And heat treatment in the state of a mixture of
Molecules with high dispersibility between groups and a particle size of 5 nm or less
Of organosilicon at the level of oligomers uniformly dispersed at the same level
That the compound is easy to produce,²⁹Chemical shift of Si-NMR
I knew from Organic compounds of the general formula (3) or (4)
A silicon compound (where R represents an addition reaction with the acid anhydride)
An organic group containing a functional group,¹And R^Two
Is a methyl or ethyl group)²⁹Si-NMR
The chemical shift shows absorption from -41 ppm to -44 ppm.
It is. Further, Si—O— as represented by the general formula (5)
Si with one Si bond ²⁹Chemical shift of Si-NMR
Is

[0020]

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Absorption appears from -48 ppm to -52 ppm. Further, as shown in the general formula (6),

[0022]

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Si ²⁹ having two Si—O—Si bonds
The chemical shift of Si-NMR is from -53 ppm to -63 pp
Absorption appears at m. Further, the bonding of Si—O—Si as represented by the general formula (7)

[0024]

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The absorption of the chemical shift of ²⁹ Si-NMR of Si having three groups appears from -63 ppm to -72 ppm.

[0026] The heat-cured resin of the present invention, ²⁹ S
When the chemical shift of i-NMR is measured, an absorption appears from -40 ppm to -75 ppm. Of these, -53pp
The integrated value of the absorption from m to -75 ppm is from -40 ppm to -52.
Since the value was larger than the integrated value of the absorption in ppm, it was found that the organosilicon compound in the resin formed a bond of Si—O—Si to form a molecule having a size of about an oligomer. As described above, even if the molecular weight of the organosilicon compound increases, the resin composition before curing has a low viscosity because of good compatibility with the epoxy resin. Further, the reason why the decrease in the elastic modulus in the temperature region above Tg, which is a feature of the present invention, is small, is that in the base resin, the polyfunctional epoxy resin, the organosilicon compound, and the acid anhydride, the physical property change with temperature change. is small, uniformly to produce a mechanically stable SiO ₂ skeleton at the molecular level, also its SiO ₂
By providing a functional group that is covalently bonded to the curing agent at the end of the skeleton, it is combined with the curing agent, and the change in the elastic modulus of the cured product with respect to temperature change can be reduced. Even in a temperature range exceeding Tg, the elastic modulus is reduced. Infer that there are few. Therefore, a cured product obtained by adding silica, alumina, or the like as a filler to such a resin composition can provide an insulating spacer having excellent mechanical properties particularly in a high-temperature region.

[0027]

(Example 1 and Comparative Example 1) In this example, 3-glycidoxytrimethoxysilane (manufactured by Chisso Corporation) was used as an organosilicon compound, and tin dibutyl dilaurate was used as a hydrolysis catalyst. (Wako Pure Chemical Industries, Ltd.) and bisphenol A / F type epoxy resin (Ciba Specialty Chemicals Co., Ltd.) as polyfunctional epoxy resin.
PY-302-2), methylhexahydrophthalic anhydride (HN5500, manufactured by Hitachi Chemical Co., Ltd.) as an acid anhydride curing agent, and aluminum fluoride (Nippon Light Metal Co., Ltd.) as a filler. ) Product name, T-32
6) as 1- (2-cyanoethyl)-as a curing accelerator
2-ethyl-4-methylimidazole (Shikoku Chemicals Co., Ltd.)
And trade name 2E4MZ-CN).

The epoxy resin composition for an insulating spacer of this example was produced by the following production method. (1) 5.5 parts by weight of water and 0.6 parts by weight of tin dibutyl dilaurate are added to 55 parts by weight of 3-glycidoxytrimethoxysilane, and the mixture is stirred and left overnight at room temperature. (2) 100 parts by weight of a bisphenol A / F type epoxy resin is added to the mixed solution of (1) and stirred. (3) The mixed solution of (2) is heat-treated at 150 ° C. for 4 hours. (4) 135 parts by weight of methylhexahydrophthalic anhydride and 722 parts by weight of aluminum fluoride are added to the heat-treated mixture of (3), and the mixture is stirred. (5) 1- (2-cyanoethyl) -2 was added to the mixed solution of (4).
0.13 parts by weight of -ethyl-4-methylimidazole was added and stirred again to obtain an epoxy resin composition for an insulating spacer.

Next, the obtained epoxy resin composition was applied to a width 14
The resin was poured into a mold having a size of 0 mm, a height of 120 mm, and a thickness of 5 mm. The prepared resin plate was measured for dynamic viscoelasticity and the like. In this embodiment, it is considered that about 1 to 2 m of epoxy silicon oligomer is dispersed.

The measurement of the dynamic viscoelasticity was carried out by using a rheology
Using a VE Rheospectra apparatus, the temperature was raised at a rate of 2 ° C./min.
Frequency 10Hz, distance between chucks 20mm, displacement amplitude 2
μm. At this time, Tg (glass transition temperature) and 50
° C., was examined the ratio of the integral value of the peak of the storage modulus and ²⁹ Si-NMR by the chemical shift at 200 ° C.. Further, the mechanical strength was measured by a bending test. In the bending test, a test piece having a width of 10 mm, a length of 120 mm and a thickness of 5 mm was cut out from a resin plate, and a bending test apparatus (Shimadzu Corporation, DS
(S-500 type), and measured at room temperature (23 ° C.) and 140 ° C. with a distance between supporting points of 80 mm and a deflection speed of 2 mm / min.

Further, as a comparison, the properties of the cured product when starting from the step (2) without going through the step (1) in the above production method were also examined.

Table 1 shows the results of these measurements. This implementation
The cured product obtained in the example was compared with the properties of the cured product of Comparative Example 1.
Tg is about the same, but the storage elastic modulus above Tg (2
20 ° C) and bending strength (140 ° C)
high elastic modulus even at temperatures exceeding
Excellent reliability. In addition, of the cured product in this embodiment ²⁹
Chemical shift of -53 ppm to -72 in Si-NMR
The peak integrated value in ppm is -40 to -52 ppm peak.
10.5 times the peak integration value,
The product was an oligomer-level molecule.

[0033]

[Table 1]

FIG. 1 is a perspective view of a post-type insulating spacer using the cured resin of the present embodiment. Since it was confirmed that the resin cured product of this example had excellent mechanical strength reliability in a temperature range exceeding Tg, the epoxy resin composition of this example was further applied to a post-type insulating spacer (outside center). Diameter 80φ, height 90mm, embedded electrode outer diameter 45m
m, distance between electrodes 40 mm)
Heat curing for 10 hours at + 150 ° C for 15 hours.
Was manufactured. No defect was found in the external observation, and a good post-type insulating spacer was obtained. Then, the mechanical strength of the manufactured post-type insulating spacer was tested. In the test, the above-mentioned bending test apparatus was used, and a dimensional change in the height direction after applying a load of 5 kg / cm ² to the embedded electrode of the post-type insulating spacer in an atmosphere at 140 ° C. for 2 hours was examined. As a result, the height of the post-type insulating spacer obtained in this example was 85 mm and 5 mm.
In contrast, the post-type insulating spacer made of the resin composition shown in Comparative Example 1 had a height of 65 mm and a deformation of 25 mm.

According to the present embodiment, by forming the insulating spacer from a resin composition having a high elastic modulus at a temperature equal to or higher than Tg, it is possible to obtain an insulating spacer having little deformation with respect to mechanical strength and excellent reliability.

Example 2 and Comparative Example 2 In this example, bisphenol A type epoxy resin (AER260, trade name, manufactured by Asahi Ciba Co., Ltd.) was used as a polyfunctional epoxy resin, and 2- (3,4) was used as an organosilicon compound. -Epoxycyclohexyl) ethyltrimethoxysilane (manufactured by Chisso Corporation) as a filler and crystalline silica (manufactured by Tatsumori Corporation, trade name CB)
An epoxy resin composition for an insulating spacer was prepared in the same manner as in Example 1 except that ASE-1) was used (however, the amount of crystalline silica added was 618 parts by weight). An epoxy resin composition containing no organosilicon compound was prepared in the same manner as in Comparative Example 1 except that the above-mentioned materials were used. For these resin compositions, resin plates were prepared in the same manner as in Example 1, and cured product characteristics were examined in the same manner as in Example 1.

Table 2 shows the results of these measurements. The cured product of this example has a characteristic of high flexural strength especially at room temperature or high temperature (140 ° C.), and when compared with the cured product characteristics of the comparative example, the Tg is about the same, but the storage at Tg or more. The elastic modulus (220 ° C.) and the flexural strength (140 ° C.) are less reduced, and the elastic modulus is high and the mechanical strength is excellent even at a temperature exceeding Tg. In addition, the peak integrated value of the chemical shift of the cured product in the present example from -53 ppm to -72 ppm in ²⁹ Si-NMR is from -40 to -52 pp.
Example 1 was 12.0 times the peak integrated value of m.
An organosilicon compound having a size similar to that of was a molecule at the oligomer level.

[0038]

[Table 2]

It was confirmed that the cured resin of the present example had excellent mechanical strength reliability in a temperature range exceeding Tg. Similarly, a post-type insulating spacer was manufactured. No defects were found in the external observation,
A good post-type insulating spacer was obtained. Therefore, the first embodiment
The mechanical strength of the post-type insulating spacer was evaluated in the same manner as described above. As a result, the height of the post-type insulating spacer obtained in the present example was changed to 88 mm and 2 mm, while that of the comparative example 2 was changed.
The post-type insulating spacer made with the resin composition of
Deformed by 0 mm and 20 mm.

According to this embodiment, by forming the insulating spacer from a resin composition having a high elastic modulus at a temperature of Tg or higher, it is possible to obtain an insulating spacer which has a particularly small deformation with respect to the mechanical strength and a very excellent reliability. Can be.

Example 3 and Comparative Example 3 In this example, bisphenol F type epoxy resin (trade name: EP-4901, manufactured by Asahi Denka Co., Ltd.) was used as a polyfunctional epoxy resin, and 3-glycidyl was used as an organosilicon compound. Same as Example 1 except that xyloxypropyltriethoxysilane (manufactured by Chisso Corporation) was replaced by alumina (manufactured by Showa Denko KK, trade name: FA-1) as a filler (however, the amount of alumina added was 920). Parts by weight) to produce an epoxy resin composition for insulating spacers. An epoxy resin composition containing no organosilicon compound was prepared in the same manner as in Comparative Example 1 except that the above-mentioned materials were used. For these resin compositions, resin plates were prepared in the same manner as in Example 1, and cured product characteristics were examined in the same manner as in Example 1.

Table 3 shows the results of these measurements. The cured product of this example has a characteristic of high flexural strength especially at room temperature or high temperature (140 ° C.), and when compared with the cured product characteristics of the comparative example, the Tg is about the same, but the storage at Tg or more. The elastic modulus (220 ° C.) and the flexural strength (140 ° C.) are less reduced, and the elastic modulus is high and the mechanical strength is excellent even at a temperature exceeding Tg. In addition, the peak integrated value of the chemical shift of the cured product in the present example from -53 ppm to -72 ppm in ²⁹ Si-NMR is from -40 to -52 pp.
m, which was 9.2 times the peak integrated value, and the organosilicon compound was an oligomer-level molecule.

[0043]

[Table 3]

Since it was confirmed that the cured resin of this example had excellent mechanical strength reliability in a temperature range exceeding Tg, the epoxy resin composition of this example was further used, and Similarly, a post-type insulating spacer was manufactured. No defects were found in the external observation,
A good post-type insulating spacer was obtained. Therefore, the first embodiment
The mechanical strength of the post-type insulating spacer was evaluated in the same manner as described above. As a result, the height of the post-type insulating spacer obtained in this example was changed to 87 mm and 3 mm, while that of Comparative Example 3 was changed.
The post-type insulating spacer made with the resin composition of
Deformed by 0 mm and 20 mm.

According to the present embodiment, by forming the insulating spacer with a resin composition having a high elastic modulus at a temperature of Tg or higher, it is possible to obtain an insulating spacer which has a particularly small deformation with respect to the mechanical strength and a very excellent reliability. Can be.

[0046]

According to the present invention, the cured epoxy resin uniformly contains a mechanically stable SiO ₂ skeleton at the molecular level, so that the change in the elastic modulus with respect to temperature change is small and the epoxy resin cured region exceeds the glass transition temperature. In this case, an insulating spacer having less deformation due to a mechanical load and excellent reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a post-type insulating spacer of the present invention.

[Explanation of symbols]

 1 ... epoxy resin cured product, 2 ... embedded electrode.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 83/04 C08L 83/04 5G365 H01B 3/40 H01B 3/40 A C H02B 13/02 H02G 5/06 351Z H02G 5/06 351 C08G 59/32 // C08G 59/32 H02B 13/06 S (72) Inventor Seichi Nakai 7-1-1, Omika-cho, Hitachi City, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi Ltd. (72 Inventor Katsuo Sugawara 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd.Hitachi Research Laboratory (72) Inventor Yuichi Sado 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. F-term in Hitachi Laboratory (reference) 4J002 CD00W CD02W CD05W CP05X DD036 DE076 DE146 DE236 DJ016 DK006 FD016 GQ01 4J035 BA11 CA111 EA01 E B02 LB02 LB03 4J036 AB07 AB20 AC08 AD07 AD08 AJ21 DB15 JA06 JA07 5G017 FF07 5G305 AA02 AA20 AB01 AB15 AB24 BA26 CA15 CA26 CC02 CD01 5G365 DA14 DF01

Claims (6)

[Claims] 1. An insulating spacer for insulating and supporting a conductor provided in a container filled with an insulating gas, wherein the insulating spacer is represented by the following general formula (1) or (2): Formula 1 Embedded image (R is an organic group containing a functional group that causes an addition reaction with an acid anhydride, n is 0 to 3, and X is H, CH ₃ or C ₂ H ₅ ); An insulating spacer formed of a cured product of an epoxy resin composition containing a material and an inorganic filler. 2. The cured product has a storage modulus at 200 ° C. of 1 GPa or more and a flexural strength at 140 ° C. of 55
An insulating spacer having at least one characteristic of MPa or more. 3. The insulating spacer according to claim 1, wherein said filler is silica or alumina. 4. An insulating spacer according to claim 1, wherein the insulating spacer is provided to insulate and support a conductor provided in a container filled with an insulating gas of sulfur hexafluoride (SF ₆ ) gas. Gas insulated switchgear. 5. A gas-insulated conduit provided with the insulating spacer according to claim 1 or 2, which supports the power-carrying portion conductor of the aerial transmission line insulated from the sealed container. 6. A method of manufacturing an insulating spacer for insulating and supporting a conductor disposed in a container filled with an insulating gas,
The insulating spacer is represented by the following general formula (3) or (4): Embedded image Wherein R is an organic group containing a functional group that causes an addition reaction with the acid anhydride, and R ¹ and R ² are a methyl group or an ethyl group; and water;
A step of producing an organosilicon mixed solution containing a hydrolysis catalyst, and a step of producing an epoxy resin mixed solution in which an epoxy resin is added to the mixed solution and heat-mixed, and an acid anhydride in the epoxy resin mixed solution, A method for producing an insulating spacer, comprising adding and mixing an inorganic filler, and then injecting the mixed solution into a desired mold and curing by heating.