JP4476646B2 - Insulating resin composition for high voltage equipment, insulating material and method for producing the same, and insulating structure - Google Patents

Description

  The present invention relates to an insulating resin composition used for high voltage devices such as a generator, a rotating electrical machine, and a power transmission / transformation device, an insulating material using the same, a manufacturing method thereof, and an insulating structure.

  An insulating coil incorporated in a generator, a rotating electrical machine, or the like includes a conductor for flowing electricity and an insulating layer for blocking between conductors or between the conductor and ground. An insulating resin material is used for the insulating layer of such an insulating coil. In addition, in a power transmission and transformation device such as a sulfur hexafluoride gas insulated switchgear and an in-pipe power transmission device, a cast member made of an insulating resin is used as an insulating member that insulates and supports a high voltage conductor in a metal container, for example. . Insulating resin materials based on epoxy resins are generally used for the insulating structural members of such high voltage devices from the viewpoint of electrical insulation, chemical stability, mechanical strength, heat resistance, cost, etc. It has been.

  In applications such as those mentioned above, epoxy resins are impregnated resins applied to mica paper made of hard unfired laminated mica, hard fired laminated mica, etc., and casting resins containing inorganic fillers such as silica, alumina, boron nitride, etc. It is used as As described above, in the insulating structure member of the high voltage device, necessary properties are obtained by combining the epoxy resin with an inorganic compound such as mica paper or silica particles.

  By the way, in the development of organic / inorganic composite materials that combine a polymer compound and an inorganic compound to impart characteristics according to the purpose of use, in recent years, lamellar clay minerals are dispersed in a thermoplastic resin such as a polyamide resin. Therefore, composite materials with improved characteristics such as mechanical strength and heat resistance have been proposed (see, for example, Patent Documents 1 to 3). In manufacturing an organic / inorganic composite material using such a layered clay mineral, a technique for suppressing the aggregation of the layered clay mineral and uniformly dispersing it in the resin is indispensable.

  Regarding the above-mentioned uniform dispersion technology of layered clay minerals, for example, in Patent Document 1, organic clay is added to and mixed with an ionomer resin, and this is heated and melted, and a shearing force is obtained using a biaxial extrusion mixer or the like. Describes a technique for uniformly dispersing a lamellar clay mineral in an ionomer resin by adding. In Patent Document 2 and Patent Document 3, a dispersion solution in which a layered clay mineral is dispersed in a dispersion medium such as water, tripolyphosphate, and polyacrylate is prepared, and this dispersion solution is used as a thermoplastic resin such as a polyamide resin. A technique is described in which a layered clay mineral is uniformly dispersed in a resin by mixing with the resin.

  However, since the uniform dispersion technique of the layered clay mineral described in Patent Document 1 is a method in which a resin is melted and mixed by heating, heat such as an ionomer resin or a polyamide resin capable of controlling the viscosity at the heating temperature. Although effective for plastic resins, it is not applicable to thermosetting resins such as epoxy resins that are cured by heat.

Moreover, in the uniform dispersion technique of the layered clay mineral described in Patent Document 2 and Patent Document 3, it is necessary to finally remove the dispersion medium such as water, tripolyphosphate, and polyacrylate used for preparing the dispersion solution. Therefore, it cannot be said that the method is industrially suitable. In addition, even if the dispersion medium is removed after mixing the dispersion solution of the layered clay mineral with the resin, it is difficult to completely remove the dispersion medium from the resin. Therefore, the low molecular weight dispersion in the high molecular weight resin is difficult. There is a medium, and there is a possibility that the mechanical strength and heat resistance of the insulating resin material are lowered.
Japanese Patent Laid-Open No. 10-324810 Japanese Patent Laid-Open No. 10-158431 Japanese Patent Laid-Open No. 9-111116

  As described above, layered clay minerals are effective in improving the mechanical strength and heat resistance of insulating resin materials in insulating structural members (insulating materials) for high-voltage equipment, but the layered clay minerals are uniformly dispersed in the resin. Is essential. In contrast, conventional insulating resin materials using layered clay minerals are based on thermoplastic resins such as ionomer resins and polyamide resins, so the method of uniformly dispersing layered clay minerals applied here Has a problem that it cannot be applied to a thermosetting resin such as an epoxy resin, and a problem that mechanical strength, heat resistance, and the like of an insulating resin material after curing are lowered.

  The present invention has been made to cope with such problems, and in dispersing the layered clay mineral in the epoxy resin, which is a thermosetting resin, the mechanical strength, heat resistance, etc. of the cured resin by the dispersion medium. Insulating resin composition for high voltage equipment that enables uniform dispersion of layered clay minerals in epoxy resin while suppressing the deterioration, insulation characteristics and heat resistance etc. by using such insulating resin composition An object of the present invention is to provide an insulating material for high voltage equipment that can be improved with good reproducibility, a manufacturing method thereof, and an insulating structure for high voltage equipment using such an insulating material.

The insulating resin composition for power generation equipment / transmission / transformation equipment of the present invention comprises (A) an epoxy resin having two or more epoxy groups per molecule, (B) a curing agent for epoxy resin, and (C) a layered clay mineral. And (D) a dispersion medium containing 50% by volume or more of a reactive solvent having reactivity with the component (B) as an essential component, and 100 parts by mass of the component (A) The component (D) is contained in an amount of 1 to 100 parts by mass, and the reactive solvent is composed of an organic compound having one epoxy group per molecule . Further, the power generation equipment and transmission substation equipment dexterity insulating material of the present invention is characterized by comprising a cured product of the power generation equipment and transmission substation equipment insulating resin composition of the present invention described above.

The method for producing an insulating material for power generation equipment / transmission / transformation equipment according to the present invention includes (A) an epoxy resin having two or more epoxy groups per molecule, (B) a curing agent for epoxy resin, and (C) layered clay. 100 parts by mass of the component (A) containing 50% by volume or more of a reactive solvent having reactivity with the component (B), which is composed of a mineral and an organic compound having (D) one epoxy group per molecule In producing an insulating material for power generation equipment and power transmission and transformation equipment using 1 to 100 parts by mass of the dispersion medium, a step of swelling the layered clay mineral in the dispersion medium containing the reactive solvent; The step of mixing the layered clay mineral swollen with the dispersion medium into the epoxy resin, the step of adding and mixing the curing agent for epoxy resin to the mixture, and the mixture containing the curing agent into a desired shape Molding step and the molded body It is characterized by comprising a step of curing by the curing agent.

The insulating structure for power generation equipment / transmission / transformation equipment according to the present invention is characterized by comprising an insulating member made of the above-described insulating material for power generation equipment / transmission / transformation equipment .

  According to the insulating resin composition for high voltage equipment of the present invention, since the reactive solvent is used as a dispersion medium for the layered clay mineral, the layered clay mineral can be uniformly dispersed in the epoxy resin. Furthermore, since the reactive solvent as the dispersion medium is taken into the cured epoxy resin during the curing process, it is possible to suppress a decrease in heat resistance or the like of the cured epoxy resin. By these, it becomes possible to provide with high reproducibility an insulating material for high voltage equipment having improved mechanical strength and heat resistance based on the layered clay mineral. Furthermore, according to the insulating structure using such an insulating material for high-voltage equipment, the characteristics and reliability of the high-voltage equipment can be improved.

  Hereinafter, modes for carrying out the present invention will be described. An insulating resin composition for high-voltage devices according to an embodiment of the present invention includes (A) an epoxy resin having two or more epoxy groups per molecule, (B) a curing agent for epoxy resin, and (C) layered clay. It contains mineral and (D) a dispersion medium containing a reactive solvent as essential components.

  Among the essential components of the above-described insulating resin composition for high voltage equipment, the epoxy resin of component (A) is composed of an epoxy compound having two or more epoxy groups per molecule. As such an epoxy compound, two or more three-membered rings composed of two carbon atoms and one oxygen atom in one molecule can be used as appropriate as long as they are curable compounds. It is not particularly limited.

  Specific examples of the component (A) epoxy resin include bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, hydrogenated product obtained by condensation of epichlorohydrin with polyhydric phenols such as bisphenols and polyhydric alcohols. Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, novolac type epoxy resin, phenol novolac type epoxy resin, Glycidyl ether type epoxy resins such as orthocresol novolac type epoxy resin, tris (hydroxyphenyl) methane type epoxy resin, tetraphenylolethane type epoxy resin, and epichlorohi Examples include glycidyl ester type epoxy resins obtained by condensation of phosphorus and galbonic acid, heterocyclic epoxy resins such as triglycidyl isocyanate and epidanhydrin and hydantoin type epoxy resins obtained by reaction of hydantoins, etc. Used alone or as a mixture of two or more.

  The epoxy resin curing agent (B) can be used as appropriate as long as it can chemically react with the epoxy resin to cure the epoxy resin, and the type thereof is not particularly limited. Examples of such curing agents for epoxy resins include amine curing agents, acid anhydride curing agents, imidazole curing agents, polymercaptan curing agents, phenol curing agents, Lewis acid curing agents, and isocyanate curing agents. Etc.

  Specific examples of the above-described amine curing agents include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, hexamethylenediamine, dipropylenediamine, polyether diamine, 2,5-dimethylhexamethylenediamine, trimethyl Hexamethylenediamine, diethylenetriamine, iminobispropylamine, bis (hexamethyl) triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, aminoethylethanolamine, tri (methylamino) hexane, dimethylaminopropylamine, diethylaminopropyl Amine, methyliminobispropylamine, mensendiamine, isophoronediamine, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, bis ( Minomethyl) cyclohexane, N-aminoethylpiperazine, 3,9-bis (3-aminopropyl) 2,4,8,10-tetraoxaspiro (5,5) undecane, m-xylenediamine, metaphenylenediamine, Examples include diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldiphenylmethane, dicyandiamide, and organic acid dihydrazide.

  Specific examples of acid anhydride curing agents include dodecenyl succinic anhydride, polyadipic acid anhydride, polyazeline acid anhydride, polysebacic acid anhydride, poly (ethyloctadecanedioic acid) anhydride, poly (phenylhexadecanedioic acid) Anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhymic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexenedicarboxylic anhydride, phthalic anhydride , Trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid, ethylene glycol bis trimellitate, glycerol tris trimellitate, het anhydride, tetrabromophthalic anhydride, nadic anhydride, methyl nadic anhydride, poly Etc. Zerain acid, and the like.

  Specific examples of the imidazole curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-heptadecylimidazole and the like. Specific examples of the polymercaptan curing agent include polysulfide and thioester. Any of the above-mentioned curing agents can be used alone or as a mixture of two or more.

  (B) Although the compounding quantity of the hardening | curing agent for epoxy resins of a component is suitably set within the range of an effective amount according to the kind etc. of hardening | curing agent used, generally (A) component (A) It is preferable to be in the range of 1/2 equivalent to 2 equivalents relative to the epoxy equivalent. When the blending amount of the curing agent of the component (B) is less than 1/2 equivalent to the epoxy equivalent of the component (A), the curing reaction of the epoxy resin of the component (A) may not be sufficiently caused. is there. On the other hand, if the blending amount of the curing agent of component (B) exceeds 2 equivalents relative to the epoxy equivalent of component (A), the heat resistance of the cured product of the insulating resin composition (epoxy resin composition) may be reduced. There is.

  Furthermore, you may use the hardening accelerator for epoxy resins which accelerates | stimulates or controls the hardening reaction of an epoxy resin in combination with the hardening | curing agent for epoxy resins of (B) component. In particular, when an acid anhydride-based curing agent is used, the curing reaction is slower than other curing agents such as an amine-based curing agent, and thus an epoxy resin curing accelerator is often used. As a curing accelerator for an acid anhydride curing agent, it is preferable to use a tertiary amine or a salt thereof, a quaternary ammonium compound, imidazole, an alkali metal alkoxide, or the like.

  Examples of the layered clay mineral of component (C) include at least one selected from a mineral group consisting of a smectite group, a mica group, a vermiculite group, and a mica group. Examples of the layered clay mineral belonging to the smectite group include montmorillonite, hectorite, saponite, saconite, beidellite, stevensite, nontronite and the like. Examples of the layered clay mineral belonging to the mica group include chlorite, phlogopite, lepidrite, mascobite, biotite, paragonite, margarite, teniolite, tetrasilicic mica and the like. Examples of the layered clay mineral belonging to the vermiculite group include trioctahedral vermiculite and dioctahedral vermiculite. Examples of the layered clay mineral belonging to the mica group include muscovite, biotite, paragonite, levitrite, margarite, clintonite, and anandite. Among these, it is desirable to use a layered clay mineral belonging to the smectite group from the viewpoint of dispersibility in an epoxy resin. These layered clay minerals can be used alone or as a mixture of two or more.

  (C) It is preferable to make the compounding quantity of the layered clay mineral of a component into the range of 1-30 mass parts with respect to 100 mass parts of epoxy resins of (A) component. When the blending amount of the layered clay mineral of component (C) is less than 1 part by mass with respect to 100 parts by mass of component (A), the mechanical strength or heat resistance of the cured epoxy resin may not be sufficiently increased. is there. On the other hand, if the amount of the layered clay mineral of component (C) exceeds 30 parts by mass with respect to 100 parts by mass of component (A), the cured epoxy resin becomes brittle and the basic characteristics as an insulating material for high voltage equipment are reduced. To do. The blending amount of the layered clay mineral of component (C) is more preferably in the range of 5 to 15 parts by mass with respect to 100 parts by mass of component (A).

  In addition, the layered clay mineral of component (C) has a structure in which silicate layers are laminated, and various substances such as ions, molecules, clusters, etc. are retained between the silicate layers by an ion exchange reaction (intercalation). I can. For example, various organic compounds can be inserted between the silicate layers of the layered clay mineral. By utilizing such a property, it becomes possible to use a layered clay mineral in which an organic compound imparting affinity for an epoxy resin is inserted between silicate layers. The organic compound inserted between the silicate layers is not particularly limited, but it is desirable to use quaternary ammonium ions in consideration of the degree of insertion between the layers by ion exchange treatment.

  Quaternary ammonium ions include tetrabutylammonium ion, tetrahexylammonium ion, dihexyldimethylammonium ion, dioctyldimethylammonium ion, hexatrimethylammonium ion, octatrimethylammonium ion, dodecyltrimethylammonium ion, hexadecyltrimethylammonium ion, stearyltrimethyl Ammonium ion, dococenyltrimethylammonium ion, cetyltrimethylammonium ion, cetyltriethylammonium ion, hexadecylammonium ion, tetradecyldimethylbenzylammonium ion, stearyldimethylbenzylammonium ion, dioleyldimethylammonium ion, N-methyldiethanol laur Ryl ammonium ion, dipropanol monomethyl lauryl ammonium ion, dimethyl monoethanol lauryl ammonium ion, polyoxyethylene dodecyl monomethyl ammonium ion, dimethyl hexadecyl octadecyl ammonium ion, trioctyl methyl ammonium ion, tetramethyl ammonium ion, tetrapropyl ammonium ion, etc. Can be mentioned. These quaternary ammonium ions can be used alone or as a mixture of two or more.

  Furthermore, the layered clay mineral of component (C) is used by modifying its surface with a coupling agent for the purpose of improving the adhesion with the epoxy resin or suppressing reaggregation in the resin. May be. Examples of coupling agents as surface modifiers for such layered clay minerals include γ-glycidoxy-propyltrimethoxysilane, γ-aminopropyl-trimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxy. Silane coupling agents such as silane and 3-glycidyloxypropyl-trimethoxysilane, titanate coupling agents, aluminum coupling agents and the like are used. These coupling agents can be used alone or as a mixture of two or more.

  The dispersion medium for component (D) contains at least a reactive solvent. The reactive solvent here is a solvent having reactivity with the epoxy resin curing agent (B), specifically, an organic compound having one or more epoxy groups per molecule is used. It is done. Examples of such an organic compound having an epoxy group include butyl glycidyl ether, alkylene monoglycidyl ether, alkylphenol monoglycidyl ether, polypropylene glycol diglycidyl ether, and alkylene diglycidyl ether. These organic compounds can be used alone or as a mixture of two or more.

  The reactive solvent described above increases the dispersibility of the (C) component layered clay mineral with respect to the (A) component epoxy resin, and also reacts with the (B) component epoxy resin curing agent during curing to cure the epoxy resin. It is taken in, and this suppresses the fall of the heat resistance etc. of a cured epoxy resin. It is preferable to use such a reactive solvent alone as the dispersion medium for component (D). However, within the range of 50% by volume or less of the dispersion medium, for example, toluene, xylene, benzene, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, propanol, isopropanol, propyl alcohol, isopropyl alcohol, hexane, cyclohexane, cyclopentane , N-methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, ethyl acetate, acetonitrile, diethyl ether, tetrahydrofuran, carbon tetrachloride, dichloromethane, chloroform, chlorobenzene and the like can be used in combination. The dispersion medium of component (D) preferably contains 50% by volume or more, more preferably 80% by volume or more of the reactive solvent. When the amount of the reactive solvent is less than 50% by volume of the dispersion medium, the heat resistance and the like of the cured epoxy resin are likely to be lowered.

  (D) It is preferable that the compounding quantity of the dispersion medium containing the reactive solvent of a component shall be 1-100 mass parts with respect to 100 mass parts of epoxy resins of (A) component. When the blending amount of the dispersion medium of component (D) is less than 1 part by mass with respect to 100 parts by mass of component (A), the dispersibility of the layered clay mineral of component (C) with respect to the epoxy resin of component (A) is sufficient. There is a risk that it cannot be increased. On the other hand, if the blending amount of the dispersion medium of component (D) exceeds 100 parts by mass with respect to 100 parts by mass of component (A), the heat resistance of the cured epoxy resin may be reduced. In addition, the compounding quantity of above-described (D) component shows the compounding quantity in the step which prepares an insulating resin composition. As will be described later, a part of the dispersion medium as the component (D) may be removed before the curing treatment (specifically, before blending the curing agent). The content of the component (D) after the removal treatment is preferably in the range of 0 to 10 parts by mass with respect to 100 parts by mass of the component (A), for example.

  In addition, in addition to the components (A) to (D) as the essential components described above, the insulating resin composition for high-voltage devices includes the above-described curing accelerator and other additives within a range that does not impair the effects of the present invention. You may mix | blend as needed. For the other additives blended in the insulating resin composition, various known materials usually blended in the epoxy resin composition can be applied, such as silica, alumina, calcium carbonate, aluminum hydroxide, titanium white, etc. Inorganic fillers, leveling agents, antifoaming agents, pigments and the like can be mentioned.

  The insulating resin composition for high voltage devices of the above-described embodiment is produced, for example, as follows. First, the (A) component epoxy resin and the (C) component layered clay mineral are mixed using a dispersion medium containing the (D) component reactive solvent. At this time, it is preferable to swell the lamellar clay mineral in a dispersion medium containing a reactive solvent and then mix it in the epoxy resin. Furthermore, the step of swelling the layered clay mineral with the dispersion medium containing the reactive solvent and the step of mixing the swollen layered clay mineral into the epoxy resin are preferably kneaded by applying shear stress.

  In this way, the affinity of the layered clay mineral to the epoxy resin is improved by swelling the layered clay mineral with the dispersion medium containing the reactive solvent. Furthermore, it is possible to uniformly disperse the layered clay mineral in the epoxy resin by applying shear stress and kneading. The affinity of the layered clay mineral for the epoxy resin can be improved also by the organic compound (for example, quaternary ammonium ion) inserted between the layers of the layered clay mineral described above or a surface modification treatment.

  Next, the epoxy resin curing agent as the component (B) is added to and mixed with the mixture of the epoxy resin, the layered clay mineral, and the dispersion medium containing the reactive solvent. Prior to the mixing of the epoxy resin curing agent, a part of the dispersion medium containing the reactive solvent may be removed by a reduced pressure treatment or the like. Thereby, the heat resistance of the cured epoxy resin can be further improved. Thus, the objective insulating resin composition for high voltage apparatuses is obtained by adding and mixing the epoxy resin curing agent to the mixture of the epoxy resin, the layered clay mineral, and the dispersion medium.

  The above-described insulating resin composition for high-voltage devices is molded into a molded body having a desired shape by various molding processes such as impregnation, coating, casting, and sheet molding, depending on the intended use of the insulating material. An insulating material for a high voltage device can be obtained by curing the molded body by applying a curing treatment according to the type of the curing agent. In addition, in the manufacturing process of the insulating resin composition described above, optional components as described above are appropriately added and mixed as necessary.

  The insulating material 1 for a high voltage device thus obtained is, for example, as shown in FIG. 1, an epoxy resin having a three-dimensional network structure formed by a reaction between (A) an epoxy resin component and (B) a curing agent. (C) Layered clay mineral 3 is uniformly dispersed in (hardened product) 2. The reactive solvent in the dispersion medium of component (D) is taken into the three-dimensional network structure (2) by reaction with (B) the curing agent. Therefore, after suppressing deterioration of the properties of the epoxy resin itself due to the dispersion medium, (C) the cured epoxy resin having improved mechanical strength, heat resistance, etc. based on the layered clay mineral 3, that is, the insulating material 1 for high voltage equipment. Can be provided.

  Insulating materials for high-voltage devices of this embodiment include, for example, insulating layers of insulating coils used in high-voltage devices such as generators and rotating electrical machines, and power transmission / transformation devices such as gas-insulated switchgears and pipeline air transmission devices ( It is preferably used for an insulating support member of a high voltage conductor used in high voltage equipment. An insulating coil used for a generator, a rotating electrical machine, or the like includes a coil conductor that passes a high voltage current and an insulating layer that blocks between the coil conductors and between the coil conductor and the ground. The insulating layer of the insulating coil can be obtained, for example, by impregnating and applying an insulating resin composition to mica paper and curing it. Insulation support members for high-voltage conductors used in high-voltage equipment such as power transmission and transformation equipment are those that insulate and support high-voltage conductors in metal containers. For example, cast insulation obtained by casting and curing an insulating resin composition Things are used.

  The insulation material for high voltage equipment is not limited to the insulation layer of the insulation coil and the insulation support member (casting insulator) of the high voltage conductor, but the finish varnish of the generator turbine end and the insulation for the circuit breaker. It can be used for various applications such as rods, insulating paints, molded insulating parts, FRP impregnating resins, cable coating materials, and the like. In some cases, the present invention can also be applied to a high thermal conductive insulating sheet for power unit insulating encapsulant, IC substrate, interlayer insulating film for LSI element, laminated substrate, semiconductor encapsulant and the like.

  Thus, the insulating material for high voltage equipment of the present invention can be applied to various uses. In other words, in recent years, with the downsizing of industrial / heavy electrical equipment and electrical / electronic equipment, higher capacity, higher frequency band, higher voltage, severe usage environment, etc. There is a demand for performance, high reliability, high quality, and stable quality. The insulating material for high-voltage equipment according to the present invention meets these requirements. By selectively using the constituent materials as described above, various types of insulating materials such as epoxy cast insulating materials and epoxy-impregnated insulating materials can be used. It can be applied to industrial / heavy electrical equipment and electrical / electronic equipment.

  Next, specific examples of the present invention and evaluation results thereof will be described.

Example 1
First, butyl glycidyl ether (trade name: BGE, manufactured by Japan Epoxy Resin Co., Ltd.) is prepared as a reactive solvent, and a layered clay mineral (corp chemical) in which a quaternary ammonium salt is inserted between 50 parts by mass of this butyl glycidyl ether. After adding 10 parts by mass of the product, product name: STN, and swollen using an ultrasonic homogenizer (product name: MODEL450), a 3-roll mill mixer (product name: Inoue Seisakusho, product name: S-4 3/4 × 11) was passed 10 times or more and kneaded.

  Next, 100 parts by mass of bisphenol A type was obtained by adding 1 part by mass of the above-mentioned layered clay mineral butyl glycidyl ether swelling solution and silane coupling agent / γ-glycidoxy-propyltrimethoxysilane (product name: A187, manufactured by Nihon Unicar). In addition to the epoxy resin (Japan Epoxy Resin Co., Ltd., trade name: Epicoat 828), a three-roll mill mixer (Inoue Seisakusho, trade name: S-4 3/4 × 11) was passed 10 times or more and kneaded. . After completion of mixing, a part of butyl glycidyl ether was removed under reduced pressure at 100 ° C. The residual amount of butyl glycidyl ether after the vacuum treatment was about 5 parts by mass.

  Thereafter, 90 parts by mass of an acid anhydride curing agent for epoxy resin (manufactured by Shin Nippon Rika Co., Ltd., trade name: Ricacid MH-700) is added to the kneaded product after the above-described decompression treatment, and the mixture is mixed at 80 ° C. for 10 minutes. To prepare an insulating resin composition for high-voltage devices. By pouring this insulating resin composition into a mold heated to 100 ° C. in advance, and after vacuum degassing, performing a curing treatment under the conditions of 115 ° C. × 3 hours (primary curing) + 150 ° C. × 15 hours (secondary curing), The target insulating material for high voltage equipment was produced. This insulating material for high voltage devices was subjected to the characteristic evaluation described later.

Example 2
In Example 1 described above, an insulating material for a high-voltage device was produced without performing kneading by applying a shear stress using a three-roll mill mixer and removing the reactive solvent after kneading under reduced pressure. Specifically, first, a layered clay mineral (manufactured by Coop Chemical Co., Ltd.) in which quaternary ammonium salt is inserted between 10 parts by mass of butyl glycidyl ether (made by Japan Epoxy Resin Co., Ltd., trade name: BGE) as a reactive solvent. Then, 2 parts by mass of a product name: STN) was added and swollen using an ultrasonic homogenizer (BRANSON, product name: MODEL450).

  Next, 1 part by mass of the above butyl glycidyl ether swelling solution of layered clay mineral and silane coupling agent / γ-glycidoxy-propyltrimethoxysilane (manufactured by Nippon Unicar Co., Ltd., trade name: A187) was added to 100 parts by mass of bisphenol A. In addition to a type epoxy resin (trade name: Epicoat 828, manufactured by Japan Epoxy Resin Co., Ltd.), it was mixed at 70 ° C. for 12 hours using a universal mixing stirrer (trade name: 5DMV-r type manufactured by Dalton). After mixing, 90 parts by mass of an acid anhydride curing agent for epoxy resin (manufactured by Shin Nippon Rika Co., Ltd., trade name: Ricacid MH-700) was added, and mixing was performed at 80 ° C. for 10 minutes. This mixture is poured into a mold heated to 100 ° C in advance, and after vacuum degassing, it is cured under the conditions of 115 ° C x 3 hours (primary curing) + 150 ° C x 15 hours (secondary curing). An insulating material for equipment was produced. This insulating material for high voltage devices was subjected to the characteristic evaluation described later.

Comparative Example 1
In Example 1 described above, instead of the layered clay mineral in which the quaternary ammonium salt is inserted between layers, a layered clay mineral having sodium ions between layers is used, and this is directly added to and mixed with the bisphenol A type epoxy resin. In addition, an insulating material was prepared without adding a silane coupling agent, γ-glycidoxy-propyltrimethoxysilane.

  Specifically, first, 10 parts by mass of a layered clay mineral (trade name: SWN, manufactured by Corp Chemical Co.) in which sodium ions are present between the layers, 100 parts by mass of a bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., product name). In addition to Epicoat 828), the mixture was mixed at 70 ° C. for 12 hours using a universal mixing stirrer (trade name: 5DMV-r type, manufactured by Dalton). After completion of mixing, 86 parts by mass of an acid anhydride curing agent for epoxy resin (manufactured by Shin Nippon Rika Co., Ltd., trade name: Ricacid MH-700) was added, and vacuum mixing was performed at 80 ° C. for 10 minutes. This mixture was poured into a mold heated to 100 ° C. in advance, and after vacuum degassing, it was cured under conditions of 115 ° C. × 3 hours (primary curing) + 150 ° C. × 15 hours (secondary curing) to produce an insulating material. This insulating material was subjected to the characteristic evaluation described later.

Comparative Example 2
In Example 1 described above, the layered clay mineral was swollen using toluene instead of butyl glycidyl ether, which is a reactive solvent, and kneading with a three-roll mill mixer and no removal of toluene under reduced pressure were performed. An insulating material was prepared.

  Specifically, first, to 10 parts by mass of toluene (manufactured by Wako Pure Chemical Industries, Ltd.), 2 parts by mass of a layered clay mineral in which a quaternary ammonium salt is inserted between the layers (trade name: STN) is added, After swelling using an ultrasonic homogenizer (BRANSON, trade name: MODEL450), a 3-roll mill mixer (Inoue Seisakusho, trade name: S-4 3/4 × 11) is passed 10 times or more. And kneaded. Subsequently, 100 parts by mass of a bisphenol A type epoxy resin (100 parts by mass) of 1 part by mass of the toluene swelling solution of this layered clay mineral and 1 part by mass of a silane coupling agent / γ-glycidoxy-propyltrimethoxysilane (made by Nihon Unicar Co., Ltd., trade name: A187) In addition to Japan Epoxy Resin Co., Ltd., trade name: Epicoat 828), a three-roll mill mixer (Inoue Seisakusho, trade name: S-4 3/4 × 11) was passed 10 times or more and kneaded.

  Next, 80 parts by mass of an acid anhydride curing agent for epoxy resin (manufactured by Shin Nippon Rika Co., Ltd., trade name: Ricacid MH-700) was added to the above kneaded product, and mixed at 80 ° C. for 10 minutes. This mixture was poured into a mold heated to 100 ° C. in advance, and after vacuum degassing, it was cured under conditions of 115 ° C. × 3 hours (primary curing) + 150 ° C. × 15 hours (secondary curing) to produce an insulating material. This insulating material was subjected to the characteristic evaluation described later.

Table 1 summarizes the differences between the materials used in Examples 1 and 2 and Comparative Examples 1 and 2 and the manufacturing method.

  Next, with respect to insulating materials for high voltage devices according to Examples 1 and 2 and Comparative Examples 1 and 2, (1) X-ray diffraction measurement (XRD), (2) Dynamic viscoelasticity measurement (DMA), (3) Insulation The breaking strength was measured as follows. In addition, (1) X-ray diffraction measurement (XRD) was performed in order to investigate the dispersion state of the layered clay mineral in the insulating material. (2) Dynamic viscoelasticity measurement (DMA) is carried out to investigate the heat resistance characteristics of insulating materials. (3) The measurement of dielectric breakdown strength was carried out in order to investigate the insulation characteristics of the insulating material.

  (1) For X-ray diffraction (XRD), the surface of the insulating material is shaved with a sandpaper (# 240), and then the insulating material is fixed to a measuring folder, and an X-ray diffraction apparatus (manufactured by Rigaku Corporation, model: XRD-) B, CuKα ray), and measured in the range of 2θ = 0 to 10 degrees. The measurement results are shown in FIG.

  (2) For dynamic viscoelasticity (DMA), a strip-shaped test piece (width 10 mm x thickness 3 mm x length 80 mm) is cut out from an insulating material, and a dynamic viscoelasticity measuring device (trade name: DMS) manufactured by Seiko Instruments Inc. -110). While heating at a heating rate of 2 ° C / min, a 1Hz sinusoidal load was applied to the center of the test piece fixed at a distance between fulcrums of 20mm, and the temperature dependence of the storage modulus was determined from the relationship between the load and strain. Asked. The measurement results are shown in FIG.

  (3) Dielectric breakdown strength was measured with a needle-plate electrode by preparing a test piece in which a needle was molded with a resin (according to the CIGRE joint test method). After applying conductive paint to the bottom of the sample and setting and fixing it on the flat plate electrode, the breakdown voltage was measured by a short-time pressure increase method at a pressure increase rate of 0.6 kV / sec in Fluorinert (N = 5). The length from the tip of the needle electrode to the bottom of the sample was 3 mm, and the needle electrode was a steel wire having a tip angle of 30 degrees, a radius of curvature of 5 μm, a diameter of 1 mm, and a length of 60 mm. FIG. 4 shows the measurement result (average electric field) of the dielectric breakdown strength.

  As shown in the measurement result of dynamic viscoelasticity in FIG. 3 and the measurement result of dielectric breakdown strength in FIG. 4, the insulating materials according to Examples 1 and 2 have superior insulating characteristics as compared with Comparative Examples 1 and 2. It can be seen that it has heat resistance characteristics. Specific actions and effects are shown below. First, Example 1 and Comparative Example 1 are compared. In the insulating material according to Example 1, a layered clay mineral having quaternary ammonium ions between layers is swollen in a reactive solvent and then mixed with an epoxy resin. On the other hand, in Comparative Example 1, a layered clay mineral having sodium ions between layers is directly mixed with an epoxy resin. In Example 1, the surface of the layered clay mineral is modified with a silane coupling agent, but in Comparative Example 1, it is not modified. The difference in these materials and manufacturing methods has a great influence on the dispersion state of the layered clay mineral in the insulating material.

The measurement result of the X-ray diffraction shown in FIG. 2 shows the dispersion state of the layered clay mineral in the insulating material. The layered clay mineral is made of a sheet (silicate layer) in which SiO ₄ tetrahedrons are arranged two-dimensionally, and is a fine particle having a structure in which the sheets are laminated. In X-ray diffraction measurement, the reflection peak in the range of 2θ = 2 to 20 degrees is a peak derived from diffraction occurring between layers of the layered clay mineral, and the layered clay mineral exists in the resin while maintaining the layer structure. Means that. Further, when there is no clear reflection peak in the range of 2θ = 2 to 10 degrees, it indicates that the layered clay mineral is peeled between the layers, and the peeled layers are uniformly dispersed.

  In the XRD measurement result of Example 1, there is no reflection peak in the range of 2θ = 2 to 10 degrees. That is, in the insulating material according to Example 1, the layered clay mineral peels between the layers and is uniformly dispersed. On the other hand, in Comparative Example 1, a strong reflection peak can be confirmed at 2θ = 7 degrees. This indicates that the layered clay mineral mixed in the epoxy resin is present in the epoxy resin while maintaining the layer structure. As shown in the schematic diagram of FIG. 5, in the layered clay mineral in which quaternary ammonium ions exist between layers, the surface energy of the silicate layer 11 is reduced by the quaternary ammonium ions and the interlayer distance becomes long (FIG. 5A). ), The interlayer has an oleophilic atmosphere. In addition, the layered clay mineral swells due to the solvation between the quaternary ammonium ions and the reactive solvent between the layers. Therefore, by swelling with the reactive solvent 12, the surface energy of the silicate layer 11 is further reduced and the interlayer distance is further increased (FIG. 5B).

  Due to the swelling effect of such quaternary ammonium ions and reactive solvents, the affinity of the layered clay mineral to the epoxy resin is increased, and by adding shear stress using a three-roll mill mixer, the layered clay mineral is mixed. The clay mineral peels between the layers, and each layer is uniformly dispersed in the insulating material. On the other hand, as shown in the schematic diagram of FIG. 6 in Comparative Example 1, since sodium ions are present between the layers of the layered clay mineral, the distance between the layers is short and the affinity for the epoxy resin is low. For this reason, even if a shear stress is applied and mixed using a three-roll mill mixer, the layered clay mineral cannot be uniformly dispersed in the insulating material.

  Further, in the insulating material of Example 1, the surface of the layered clay mineral is modified with a silane coupling agent, but in the insulating material of Comparative Example 1, no silane coupling agent is added, and the surface of the layered clay favorite Is not modified. The silane coupling agent has high affinity for the epoxy resin in the molecule, or the affinity between the reacting site and the layered clay mineral is high, or the reacting site coexists. It is possible to improve the wettability with respect to, strengthen the adhesion with the epoxy resin, and suppress reaggregation of the dispersed layered clay mineral. For this reason, in Example 1, the layered clay mineral uniformly dispersed in the epoxy resin can be dispersed uniformly without reaggregation due to the effects of kneading by quaternary ammonium ions, shear stress, and swelling by a reactive solvent. The state can be maintained and the epoxy resin and the layered clay mineral can be strongly bonded. On the other hand, in Comparative Example 2, since the silane coupling agent was not added, the adhesive force between the epoxy resin and the layered clay mineral was weak, and the layered clay mineral was present in the epoxy resin in an aggregated state.

  The layered clay mineral uniformly dispersed in the insulating material described above imparts excellent insulating properties and heat resistance to the insulating material. Insulation breakdown of an insulator takes the form of so-called treeing breakdown, in which dendritic deterioration (electric tree) occurs and progresses in the insulator and eventually breaks. As shown in the schematic diagram of FIG. 7, the insulating material 21 of Example 1 suppresses the progress of the layered clay compound 22 evenly dispersed in the insulating material 21 even when an electrical tree is generated by application of voltage. Shows a high breakdown voltage. In the figure, reference numeral 23 denotes the tip of the needle electrode. On the other hand, as shown in the schematic diagram of FIG. 8, in the insulating material 24 of Comparative Example 1, since the layered clay mineral 25 is not uniformly dispersed, the progress of the electric tree cannot be efficiently suppressed, and a high breakdown voltage is obtained. Can not show.

  As for the heat resistance characteristics, as shown in the results of the dynamic viscoelasticity measurement in FIG. 3, the insulating material of Example 1 does not decrease in storage elastic modulus E ′ until around 165 ° C. In the insulating material, the storage elastic modulus E ′ is rapidly decreased from around 140 ° C. As shown in FIG. 1, the insulating material of Example 1 has a temperature higher than the glass transition temperature at which the thermal motion of each portion of the chain polymer forming the three-dimensional network structure of the epoxy resin becomes intense and exhibits rubber-like elasticity. However, since the uniformly dispersed layered clay mineral penetrates between the molecular chains of the epoxy resin and acts as a reinforcing material that constrains the three-dimensional network structure, the movement of the molecular chains is suppressed to around 165 ° C, and the storage modulus at room temperature Can be maintained. As a result, excellent heat resistance is exhibited. On the other hand, in the insulating material according to Comparative Example 1, since the layered clay mineral is not uniformly dispersed, the three-dimensional network structure of the epoxy resin cannot be constrained, and from around 140 ° C. which is the glass transition temperature of the epoxy resin, Storage elastic modulus falls rapidly and heat resistance cannot be expressed.

  Next, Example 2 and Comparative Example 2 are compared. In the insulating material of Example 2, the layered clay mineral is swollen with an organic compound (butyl glycidyl ether) having one or more epoxy groups per molecule using a reactive solvent. On the other hand, the insulating material of Comparative Example 2 is dispersed in toluene which is a non-reactive solvent. The layered clay mineral swells both in the reactive solvent glycidyl ether and in the non-reactive solvent toluene. By mixing these swelling solutions with epoxy resin, the layered clay mineral is dispersed almost uniformly in the insulating material. (See the X-ray diffraction results in Fig. 2 / 2θ = 3 degrees peak does not lead to delamination, only the distance between layers is increased, and some layered clay minerals that did not result in delamination) Indicates that it remains in the insulating material). However, the difference in the swelling solvent greatly affects the heat resistance of the insulating material.

  As shown in the results of the dynamic viscoelasticity measurement in FIG. 3, the insulating material according to Example 2 maintains the storage elastic modulus at room temperature up to around 155 ° C., but the insulating material according to Comparative Example 2 starts from around 135 ° C. Storage elastic modulus is decreasing. The reactive solvent butyl glycidyl ether used in Example 2 has an epoxy group that reacts with the epoxy resin curing agent in its molecule. For this reason, it is taken in the three-dimensional network structure formed by the curing reaction of the epoxy resin and the epoxy resin curing agent. On the other hand, since the non-reactive solvent toluene used in Comparative Example 2 does not react with the epoxy resin curing agent, it is not incorporated into the three-dimensional network structure. That is, low molecular weight toluene exists in the three-dimensional network structure of the high molecular weight epoxy resin, and the heat resistance characteristics of the insulating material are remarkably deteriorated.

  As described above, in the insulating material according to Example 2, the swelling solvent (reactive solvent) of the layered clay mineral itself is also taken into the three-dimensional network structure formed by the curing reaction of the epoxy resin and the epoxy resin curing agent. Excellent heat resistance is imparted while maintaining the uniform dispersibility of the layered clay mineral. That is, it is possible to provide an insulating material for high voltage equipment having high breakdown voltage and excellent heat resistance.

  Next, Example 1 and Example 2 are compared. The insulating materials according to Example 1 and Example 2 both exhibit excellent insulating characteristics and heat resistance, but when both are compared, the insulating material according to Example 1 exhibits better insulating characteristics and heat resistance. This difference is due to the manufacturing method of the insulating material according to the first and second embodiments. The insulating material according to Example 1 is kneaded by adding a layered clay mineral swollen in a reactive solvent to an epoxy resin and then applying shear stress using a three-roll mill mixer. Furthermore, the reactive solvent is removed under reduced pressure after kneading. On the other hand, in the insulating material according to Example 2, the layered clay mineral swollen in the reactive solvent was added to the epoxy resin and then mixed with a universal mixer, and after the kneading, the reactive solvent was removed under reduced pressure. Not.

  The layered clay mineral can be uniformly dispersed by swelling with a reactive solvent and then mixing with an epoxy resin. However, as in the insulating material of Example 1, a shear stress is applied using a three-roll mill mixer. In addition, by kneading, a force to peel off each layer (silicate layer) of the layered layered clay minerals works, and the layered silicate layer can be dispersed more uniformly and finely in the epoxy resin. it can. Accordingly, when the insulating materials of Example 1 and Example 2 are compared, as shown in FIG. 4, the insulating material according to Example 1 shows a higher dielectric breakdown strength.

  In addition, the reactive solvent that swells the layered clay mineral reacts with the curing agent for the epoxy resin as described above, and therefore is incorporated into the three-dimensional network structure of the epoxy resin and does not significantly reduce the heat resistance characteristics of the insulating material. . However, the crosslinking density of the epoxy resin is lowered by incorporating the molecules of the low molecular weight reactive solvent into the three-dimensional network structure of the high molecular weight epoxy resin. In the insulating material of Example 1, since the reactive solvent is finally removed by the decompression operation, the epoxy resin and the epoxy resin curing agent form a three-dimensional network structure with high crosslink density. Accordingly, when the insulating materials of Example 1 and Example 2 are compared, the insulating material according to Example 1 exhibits higher heat resistance characteristics as shown by the measurement result of dynamic viscoelasticity in FIG.

It is a figure which shows typically the fine structure of the insulating material for high voltage apparatuses by one Embodiment of this invention. It is a figure which shows the measurement result of the X-ray diffraction showing the dispersion state of the layered clay mineral in the insulating material produced by Examples 1-2 and Comparative Examples 1-2. It is a figure which shows the measurement result of the dynamic viscoelasticity showing the heat resistance characteristic of the insulating material produced by Examples 1-2 and Comparative Examples 1-2. It is a figure which shows the measurement result of the dielectric breakdown strength showing the insulation characteristic of the insulating material produced by Examples 1-2 and Comparative Examples 1-2. It is a schematic diagram which shows the interlayer distance of the layered clay mineral by the Example of this invention. It is a schematic diagram which shows the interlayer distance of the layered clay mineral by a comparative example. It is a figure which shows typically the state in which the layered clay mineral in the insulating material by the Example of this invention suppresses progress of an electric tree. It is a figure which shows typically the state which an electric tree advances in the insulating material of a comparative example.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Insulating material for high voltage apparatuses, 2,21 ... Epoxy resin hardened | cured material, 3,22 ... Layered clay mineral, 11 ... Silicate layer, 12 ... Reactive solvent.

Claims (10)

(A) An epoxy resin having two or more epoxy groups per molecule, (B) a curing agent for an epoxy resin, (C) a layered clay mineral, and (D) reactive to the component (B). A composition containing, as an essential component, a dispersion medium containing 50% by volume or more of a reactive solvent having ,
The component (D) is contained in an amount of 1 to 100 parts by mass with respect to 100 parts by mass of the component (A), and the reactive solvent is composed of an organic compound having one epoxy group per molecule. Insulating resin composition for power generation equipment and transmission / transformation equipment . In the insulating resin composition for power generation equipment / transmission / transformation equipment according to claim 1,
The layered clay mineral smectite group, mica group, vermiculite group and an insulating resin composition for electricity generation equipment and transmission substation equipment, characterized in that it consists of at least one selected from mineral group consisting of micas. In the insulating resin composition for power generation equipment / transmission and transformation equipment according to claim 1 or claim 2,
A quaternary ammonium ion is present between layers of the layered clay mineral. An insulating resin composition for power generation equipment / transmission / transformation equipment . In the insulating resin composition for power generation equipment / transmission / transformation equipment according to any one of claims 1 to 3,
An insulating resin composition for power generation equipment / transmission / transformation equipment , wherein the surface of the layered clay mineral is modified with a coupling agent. In the insulating resin composition for power generation equipment / transmission / transformation equipment according to any one of claims 1 to 4,
The said reactive solvent consists of at least 1 sort (s) chosen from the group which consists of a butyl glycidyl ether, an alkylene monoglycidyl ether, and an alkylphenol monoglycidyl ether , The insulating resin composition for power generation equipment / transmission / transformation equipment characterized by the above-mentioned. Power equipment and transmission substation equipment dexterity insulating material comprising the cured product of the power generation equipment and transmission substation equipment insulating resin composition according to any one of claims 1 to 5. (A) an epoxy resin having two or more epoxy groups per molecule, (B) a curing agent for epoxy resins, (C) a layered clay mineral, and (D) an organic having one epoxy group per molecule. Power generation using 1 to 100 parts by mass of a dispersion medium with respect to 100 parts by mass of the component (A), which contains 50% by volume or more of a reactive solvent having reactivity with the component (B) made of a compound In manufacturing insulation materials for equipment and power transmission / transformation equipment ,
Swelling the lamellar clay mineral in a dispersion medium containing the reactive solvent;
Mixing the layered clay mineral swollen with the dispersion medium into the epoxy resin;
Adding and mixing the curing agent for epoxy resin to the mixture; and
Forming a mixture containing the curing agent into a desired shape;
And a step of curing the molded body with the curing agent. A method for producing an insulating material for power generation equipment / transmission / transformation equipment . In the manufacturing method of the insulating material for power generation equipment / transmission / transformation equipment according to claim 7,
Furthermore, after mixing the layered clay mineral obtained by the swelling in the epoxy resin, power generation equipment and transmission substation equipment, characterized by comprising the step of removing at least a portion of the dispersion medium containing said reactive solvent Insulating material manufacturing method. In the manufacturing method of the insulating material for power generation equipment / transmission / transformation equipment according to claim 7 or claim 8,
A method for producing an insulating material for power generation equipment and power transmission / transformation equipment , wherein shearing stress is applied and kneaded in the step of swelling the layered clay mineral and the step of mixing the layered clay mineral into the epoxy resin. An insulating structure for a power generation device / transmission / transformation device comprising an insulating member made of the insulating material according to claim 6 .

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