JP2009099387A - Resin composition for electric insulation and method of manufacturing electric apparatus insulator using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for electric insulation, which can soften a varnish coat, can impart low dielectric constant and high thermal conductivity, and can demonstrate curing object characteristics such as electric insulation as good as or better than a conventional fluid type resin composition and excellent stability; and to provide a method of manufacturing an electric apparatus insulator using the composition. <P>SOLUTION: A resin mixture for electric insulation contains as essential materials (A) unsaturated polyester using alcohol having α,β-unsaturated dibasic acid and one or more hydroxyl groups as an essential ingredient, (B) a reactant diluent having an unsaturated group, (C) alkylbenzene formaldehyde resin, (D) silicon dioxide with a mean particle size of 0.5 to 5 μm, (E) hydrophobic silicon dioxide with a mean particle size of a primary particle of ≤500 nm, and (F) a titanate system coupling agent. The method of manufacturing the electric apparatus insulator uses this composition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a resin composition for electrical insulation and a method for producing an electrical equipment insulator using the composition, and more particularly, an electrical insulation resin mainly composed of unsaturated polyester resin, xylene / formaldehyde resin and silicon dioxide. The present invention relates to a composition and a method for producing an electrical equipment insulator, which is impregnated and dipped using the resin composition for electrical insulation.
More specifically, it has a flexible cured film and can be cured in a short time without reducing the impregnation of coils for electrical equipment such as motors, transformers, armatures (rotors), and stators (stators). In addition, the present invention relates to a resin composition for electrical equipment insulation treatment that can lower the dielectric constant and can suppress a rise in heat during energization, and a method for producing an electrical equipment insulation using the composition.

  Unsaturated polyester compositions consisting of unsaturated polyester and crosslinkable monomers are harmonized in terms of mechanical, electrical and thermal properties, workability, economy, etc. It is used for

This resin composition is widely used as an impregnation varnish for motors, transformers and the like because of its excellent characteristics and workability even for electrical insulation.
The requirements for the impregnating varnish for transformer include low-temperature and short-time curing and reduction of solvent volatilization from the varnish (no solvent).

In a low-frequency transformer such as a power transformer, noise is generated by magnetostriction or magnetic force when energized due to iron core vibration or coil vibration due to electromagnetic force.
In order to prevent this noise, it is known that the occurrence of vibration itself is prevented by increasing the fixing force of the unsaturated polyester resin for insulation treatment, depending on the structure of the device.

Moreover, since the iron core is used, the provision of rust prevention and high heat resistance is also required.
In addition, with the recent shift to digital home appliances, there is a tendency for electrical appliances for home appliances to use high-frequency transformers that can be reduced in size from low-frequency transformers that use large iron cores. This high-frequency transformer uses ferrite instead of iron for the core portion. For this reason, when the fixing force of the varnish is increased, the cured product becomes harder, the stress on the ferrite core is increased, the core shift is induced, the core portion is cracked, and the electrical characteristics are deteriorated.

Furthermore, high-frequency transformers that can be miniaturized tend to be used in electrical appliances for home appliances.
In order to cope with these, each insulating member is required to have a low dielectric constant as electrical characteristics corresponding to high frequency.

  As the resin composition as described above, according to the description in Patent Document 1, epoxy resin (dielectric constant of about 4.0), phenol resin (dielectric constant of about 4.5), polyimide resin (dielectric constant of about 3.8) ), Thermosetting polyphenylene ether resin (dielectric constant of about 2.5), polytetrafluoroethylene resin (dielectric constant of about 2.3) and the like are used as the main component. Among these, epoxy resins are generally used.

However, at present, unsaturated polyester resins that are widely used for impregnation of electrical equipment such as high-frequency and low-frequency transformers are not so often used.
In addition, as the size, weight, and output have increased, the heat storage temperature has increased, and in particular, transformers and reactor coils used in electrical equipment such as microwave ovens and inverter air conditioners are generated by excessive loads during operation. However, since the heat is stored without being dissipated and the temperature of the electrical equipment tends to rise, materials to be used are required to have higher heat resistance and higher heat dissipation.

Therefore, there is a need for a resin composition that increases the thermal conductivity of the resin composition, improves the impregnation property of the resin composition into the coil, and is excellent in crack resistance.
As a result, the heat of the electrical equipment generated during operation can be easily dissipated into the atmosphere, and the temperature rise of the electrical equipment can be reduced, making it possible to reduce the size, weight, and output of the electrical equipment. It becomes.
Moreover, when the structural member of an electric equipment is the same, it can contribute to the reliability improvement of an electric equipment.

  Furthermore, compared with electrical equipment used indoors, electrical equipment used outdoors has a severe environmental impact such as hydrolysis. When a conventional unsaturated polyester resin is used as a resin composition for electrical insulation, Due to the decomposition, the electrical insulating properties sometimes deteriorated rapidly. For this reason, a resin composition for electrical insulation having improved environmental resistance has been demanded.

  From the above, inorganic filler mixed unsaturated polyester resin has been used to increase the thermal conductivity by adding an inorganic filler to the unsaturated polyester resin, and has good impregnation into electrical equipment. When the inorganic filler is mixed with the mixture, the mixed inorganic filler settles down to form a hard cake due to standing over time, making it difficult to redisperse, and the content of the inorganic filler in the electrical insulating composition changes. In some cases, the thermal conductivity changes, and the expected heat dissipation of the electrical equipment cannot be obtained.

When the amount of the inorganic filler in the resin composition for electrical insulation is increased, the viscosity and the fluctuation are increased, the impregnation property to the electrical equipment is lowered and the heat dissipation is lowered, and the cured film is thickened and cracks are generated. Tends to occur.
Moreover, when the amount of the inorganic filler in the resin composition for electrical insulation is reduced, the impregnation property is improved, but the thermal conductivity of the resin is lowered, so that the heat dissipation property of the electric device tends to be lowered.

JP 2004-083718 A

  In view of such problems, the present invention aims to impregnate an impregnating varnish for a high-frequency transformer that is considered to become the mainstream of transformers in the future, and in a method for producing an electrical insulating resin composition and an electrical equipment insulator using the same, The varnish film can be softened, low dielectric constant and high thermal conductivity can be imparted, and cured product characteristics such as good electrical insulation and good stability equivalent to or better than conventional liquid resin compositions It is another object of the present invention to provide a method for producing an electrical equipment insulator using the electrical insulation resin mixture. is there.

  The present invention relates to an unsaturated polyester (A) using an α, β-unsaturated dibasic acid and an alcohol having one or more hydroxyl groups as essential components, a reactive diluent (B) having an unsaturated group, and an alkylbenzene. -Formaldehyde resin (C), silicon dioxide (D) with an average particle size of 0.5-5 μm, hydrophobic silicon dioxide (E) with an average primary particle size of 500 nm or less, and titanate coupling agent (F) are essential The present invention relates to a resin mixture for electrical insulation contained as a material.

Moreover, this invention relates to said resin mixture for electrical insulation whose molecular weight of unsaturated polyester (A) is the range of 1000-10000.
The present invention also provides the resin for electrical insulation as described above, wherein the reactive monomer (B) having an unsaturated group in the molecule is contained in an amount of 50 to 200 parts by weight with respect to 100 parts by weight of the unsaturated polyester (A). Relates to the composition.
Moreover, this invention relates to said resin composition for electrical insulation formed by containing 0.1-20 weight part of alkylbenzene formaldehyde resin (C) with respect to 100 weight part of said resin composition for electrical insulation.

Further, in the present invention, 10 to 100 parts by weight of silicon dioxide (D) having an average particle diameter of 0.5 to 5 μm and an average particle diameter of primary particles is 100 parts by weight of the resin composition for electrical insulation. The present invention relates to the above resin composition for electrical insulation, comprising 0.001 to 10 parts by weight of hydrophobic silicon dioxide (E) of 500 nm or less and 0.01 to 1 part by weight of a titanate coupling agent (F).
Furthermore, the present invention provides an electrical equipment insulating material characterized in that the electrical equipment is coated with an electrical insulation resin composition containing a polymerization initiator and a stabilizer on the electrical insulation resin composition and cured. It relates to a manufacturing method.

The resin composition for insulating electrical equipment according to the present invention is excellent in the flexibility of the varnish cured product, and therefore can provide a film in which cracks and the like are unlikely to occur even when stress is applied.
Moreover, since the viscosity and surface drying property of the resin composition are the same as those of conventional products, the resin composition can be widely applied to the impregnation method.
Furthermore, it is highly reliable because it has a cured product characteristic such as electrical insulation and adhesion that is equal to or better than conventional liquid type resin compositions, low dielectric constant and high thermal conductivity, and exhibits good stability. Electrical equipment can be provided.

  As the unsaturated polyester (A) using an α, β-unsaturated dibasic acid and an alcohol having one or more hydroxyl groups as essential components in the present invention, the unsaturated polyester has an unsaturated dibasic acid as an essential component. It can be obtained by reacting an acid component and an alcohol component, and if necessary, a modifying component.

As the unsaturated dibasic acid, maleic anhydride, maleic acid, fumaric acid and the like are used, and these may be used alone or in combination.
As the acid component, in addition to the unsaturated dibasic acid described above, a saturated acid and a diester of this saturated acid lower alkyl may be used in combination.

For example, terephthalic acid diesters such as monomethyl terephthalate and lower alkyl diesters of terephthalic acid such as dimethyl terephthalate are used.
Further, isophthalic acid, adipic acid, phthalic acid, sebacic acid and the like can also be used.

  Saturated acids include saturated dibasic acids such as phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, tetrahydrophthalic acid, hexahydrophthalic anhydride, hexahydrophthalic acid, adipic acid, and sebacic acid. Can be mentioned. As a diester of a saturated acid lower alkyl, for example, dimethyl terephthalate is used. These may be used alone or in combination.

  Furthermore, edible oil fatty acids such as soybean oil fatty acid, linseed oil fatty acid and tall oil fatty acid can be used in combination. The amount of the unsaturated acid is preferably selected in the range of 50 to 90 equivalent% in the total acid component.

  As the alcohol component, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-butanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol and the like are used, and these may be used alone or in combination. May be. Examples of the modifying component used as necessary include linseed oil, soybean oil, tall oil, dehydrated castor oil, coconut oil, dicyclopentadiene, and cyclopentadiene.

  The number average molecular weight of the unsaturated polyester (A) of the present invention (measured by gel permeation chromatography method and converted using a standard polystyrene calibration curve, the same applies hereinafter) is preferably 1000 to 10,000, preferably 1500 to 5000. More preferred. If it is less than 1000, the curability and resin cured product properties of the resin composition are extremely inferior, and if it exceeds 10,000, the viscosity is too high and impregnation workability tends to deteriorate.

  As a manufacturing method of unsaturated polyester (A) used for this invention, it can be based on a conventionally well-known method. For example, it occurs when an α, β-unsaturated dibasic acid, which is an essential component, and only an alcohol having one or more hydroxyl groups, or a polybasic acid component or a polyhydric alcohol component are used in combination and subjected to a condensation reaction, and both components react. The process proceeds while removing condensed water out of the system. The total alcohol component is preferably used in the range of 1 to 2 equivalents relative to 1 equivalent of the total acid component.

  Removal of the condensed water out of the system is preferably carried out by natural distillation or reduced pressure distillation through an inert gas. In order to promote the distillation of the condensed water, a solvent such as toluene or xylene can be added to the system as an azeotropic component. The progress of the reaction can be generally known by measuring the amount of distillate produced by the reaction, quantifying the functional group at the end, and measuring the viscosity of the reaction system.

  The reaction temperature for carrying out the synthesis reaction is preferably 150 to 250 ° C. For this reason, a glass, stainless steel or the like is selected as the reaction apparatus, and a stirring apparatus, a fractionation apparatus for preventing distillation of alcohol components due to azeotropy of water and alcohol components, and raising the temperature of the reaction system. It is preferable to use a reactor equipped with a heating device, a temperature control device for the heating device, and the like.

  The pressure inside the reactor adjusted to carry out the polycondensation reaction in the synthesis can proceed without any problem even at normal pressure, but the reaction is accelerated by increasing the boiling point of the polyhydric alcohol by pressurization. be able to. In this case, it is preferable to carry out in the range of normal pressure to 0.1 MPa.

  Examples of the reactive diluent (B) having an unsaturated group used in the present invention include styrene, vinyl toluene, α-methyl styrene, tertiary butyl styrene, divinyl benzene, various acrylic esters, various methacrylic esters, and various allyls. Examples include esters and various allyl ethers. These can be used alone or in combination of two or more.

  The use amount of the unsaturated polyester (A) and the reactive diluent (B) having an unsaturated group is 100 parts by weight of the unsaturated polyester (A) and the reactive diluent (B) having an unsaturated group. A range of 50 to 100 parts by weight is preferred. When the amount is less than 50 parts by weight, the viscosity of the resulting resin composition is too high and not only thickly adheres to the surface of the transformer, but also tends to deteriorate the internal permeability, and a reactive diluent having an unsaturated group ( If the amount of B) exceeds 100 parts by weight, the varnish viscosity is too low, and there is a tendency for the resin deposits that have penetrated into the interior to flow out during overheat curing.

  The component (C) alkylbenzene / formaldehyde resin used in the present invention is a resol type obtained by reacting alkylbenzene such as toluene / xylene and formaldehyde in the presence of an alkali catalyst such as sodium hydroxide, ammonia, trieramine and the like. Resin. Examples of commercially available xylene / formaldehyde resins include General Petrochemical Industry Co., Ltd., trade names Generalite 30, Generalite 50, Generalite 100, Mitsubishi Gas Chemical Co., Ltd., trade names Nikanol L, Nikanol LL, Nikanol LLL, etc. is there.

  The amount of the alkylbenzene-formaldehyde resin used as the component (C) used in the present invention is 100 parts by weight based on the total amount of the reactive diluent having an unsaturated polyester as the component (A) and an unsaturated group as the component (B). The alkylbenzene / formaldehyde resin (C) is preferably 0.1 to 50 parts by weight, more preferably 1 to 15 parts by weight, and still more preferably 5 to 10 parts by weight. If the alkylbenzene / formaldehyde resin exceeds 50 parts by weight, the surface drying time and the curing time of the resin composition will be extended, making it difficult to cure. On the other hand, when the blending amount is less than 0.1 parts by weight, the cured film of the resin composition does not become flexible, and there is a tendency that a problem that the dielectric constant does not decrease occurs.

  The silicon dioxide having an average particle size of 20 μm or less of the component (C) used in the present invention is blended mainly for the purpose of improving the heat dissipation when operating an electric device. From the viewpoint of heat dissipation, it is better that the blending amount is large. However, when the blending amount is large, the viscosity and the degree of fluctuation of the resin composition for electrical insulation are increased, and the impregnation property is lowered.

  From this, when the unsaturated polyester resin composition is 100 parts by weight, silicon dioxide having an average particle size of 20 μm or less of the component (C) is preferably in a range not exceeding 100 parts by weight, and exceeds 70 parts by weight. More preferably, it is in the range.

  Moreover, in order to improve heat dissipation, it is preferable to mix 10 parts by weight or more of silicon dioxide having an average particle size of 20 μm or less. When the blending amount of silicon dioxide having an average particle size of 20 μm or less is less than 10 parts by weight, the thermal conductivity tends to be low and the heat dissipation tends to be low. The average particle size can be calculated from a particle size distribution by a laser diffraction method.

  Hydrophobic silicon dioxide having an average primary particle diameter of component (D) used in the present invention of 500 nm or less can be easily redispersed without solidification of component (C) silicon dioxide precipitated after long-term storage. Is formulated for the main purpose.

  From the viewpoint of facilitating the redispersibility of silicon dioxide that has settled after long-term storage, the larger the amount, the better. However, if this amount is increased, the viscosity and variability of the resin composition for electrical insulation increase, and the impregnation property is increased. descend. From this, when the unsaturated polyester resin composition is 100 parts by weight, the average particle diameter of the primary particles of component (D) is preferably in the range not exceeding 10 parts by weight of hydrophobic silicon dioxide. It is more preferable that the amount not exceed 5 parts by weight.

  Further, from the viewpoint of facilitating redispersibility of silicon dioxide precipitated after long-term storage, 0.001 part by weight or more of hydrophobic silicon dioxide having an average primary particle size of component (D) of 500 nm or less is blended. Is preferred.

  When the blending amount of the hydrophobic silicon dioxide having an average primary particle size of 500 nm or less is less than 0.001 part by weight, silicon dioxide that has precipitated after long-term storage tends to solidify and redispersion becomes difficult.

  As hydrophobic silicon dioxide (D) having an average primary particle size of 500 nm or less, the surface of silicon dioxide not subjected to surface treatment is octylsilane, dimethyldichlorosilane, dimethylsilicone oil, hexamethyldisilazane, or the like. Chemical treatment can be used to make the surface hydrophobic. The average particle diameter can also be calculated from a particle size distribution by a laser diffraction method.

  The (E) component titanium coupling agent used in the present invention is blended for the purpose of lowering the viscosity and the degree of fluctuation which have been increased by the addition of silicon dioxide. From the viewpoint of lowering the viscosity and the degree of variation, the viscosity and the degree of variation decrease as the blending amount increases. However, when the blending amount increases, the viscosity becomes too low, and the average particle size of the component (C) is 20 μm or less. The sedimentation rate of silicon dioxide increases, and the precipitated silicon dioxide solidifies after long-term storage, which tends to make redispersion difficult. Moreover, when there are too few compounding quantities, there exists an effect in the fall of a viscosity and fluctuation, and there exists a tendency for the impregnation property to a coil to fall.

From this, as a compounding quantity of a titanium coupling agent, the range of 0.01-10 weight part is preferable, and the range of 0.05-0.5 weight part is especially preferable.
Titanium coupling agents include titanium stearate, di-i-proxy titanium diisostearate, (2-n-butoxycarbonylbenzoyloxy) tributoxytitanium, 2-ethylhexanoyloxytri (2-propoxy) titanium. (Both manufactured by Nippon Soda Co., Ltd.) can be used.

  As the polymerization inhibitor used as necessary in the present invention, p-benzoquinone, hydroquinone, naphthoquinone, p-toluquinone, 2,5-diphenyl-p-benzoquinone, 2,5 diacetoxy-p-benzoquinone, p-tert- Examples include butyl catechol, 2,5-di-tert-butylhydroquinone, di-tert-butyl-p-cresol, hydroquinone monomethyl ether, 2,6-di-tert-butyl-4-methylphenol. The blending amount is conveniently determined by the curability of the unsaturated polyester resin composition to be obtained, but the blending amount is 0.01 to 5.0 parts by weight with respect to 100 parts by weight of the unsaturated polyester resin composition. Preferably, it is 0.5 to 3 parts by weight.

  Examples of the curing agent used in the present invention include ketone peroxides, peroxydicarbonates, hydroperoxides, diacyl peroxides, peroxyketals, dialkyl peroxides, peroxyesters, alkyl peroxides. Examples include esters. The amount of the curing agent is determined in accordance with the curing conditions and the appearance, characteristics, etc. of the cured resin product. In view of storage stability of the material and molding cycle, the content is preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, based on the total amount of the unsaturated polyester resin and the polymerizable monomer.

  Stabilizers used as necessary in the present invention include p-benzoquinone, hydroquinone, naphthoquinone, p-toluquinone, 2,5-diphenyl-p-benzoquinone, 2,5 diacetoxy-p-benzoquinone, p-tert-butyl. Catechol, 2,5-di-tert-butylhydroquinone, di-tert-butyl-p-cresol, hydroquinone monomethyl ether, 2,6-di-tert-butyl-4-methylphenol and the like can be mentioned. The blending amount is conveniently determined depending on the storage stability of the resin composition, the curing temperature and the curing time during actual machine processing, and the blending amount is usually 0.00 with respect to 100 parts by weight of the total amount of the resin composition. The amount is preferably 5 parts by weight or less, more preferably 0.01 to 0.1 part by weight.

  The insulation treatment using the resin composition of the present invention is performed by a known method. After dipping the electric device in the resin composition of the present invention for 2 to 20 minutes, it is pulled up and 1 to 100 to 130 ° C. It is desirable to carry out by a method of curing the resin composition by heating for 3 hours.

  The resin composition according to the present invention is a high-frequency transformer / switching transformer using a ferrite that is used at a high voltage because the resulting varnish film has flexibility, can have a low dielectric constant, and is excellent in thermal conductivity. It is suitable for insulation processing of electrical equipment.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited to these. In the examples, “parts” means “parts by weight” unless otherwise specified.
<Synthesis of unsaturated polyester (A-1)>
In a 3 liter flask equipped with a thermometer, a nitrogen blowing tube, a rectifying column and a stirrer, 1474 parts (11 moles) of dipropylene glycol, 498 parts (3 moles) of isophthalic acid, 392 parts (4 moles) of maleic anhydride ), Tetrahydrophthalic anhydride (456 parts, 3 moles) and hydroquinone (0.22 parts) were added and heat condensed at 210 ° C. for 10 hours to synthesize an unsaturated polyester (A-1) having an acid value of 21.5.

<Preparation of unsaturated polyester resin composition (a-1)>
In 100 parts of unsaturated polyester (A-1), 150 parts of styrene and 1.25 parts of 8% manganese naphthenate are stirred and dissolved. Further, xylene as an alkylbenzene / formaldehyde resin is added to the unsaturated polyester composition (a-1). 10 parts of formaldehyde resin (Mitsubishi Gas Chemical Co., Ltd., trade name Nicanol LL) and 1,1-di (tert-butylperoxy) cyclohexane (manufactured by Kayaku Akzo, product name Trigonox 22E-70) Was blended to obtain an unsaturated polyester composition (a-1).

Example 1
100 parts of unsaturated polyester resin composition (a-1), 50 parts of silicon dioxide having an average particle diameter of 2 μm, 1 part of silicon dioxide having an average particle diameter of 20 nm of surface treated with octylsilane, and titanium stearate 0 10 parts were stirred and mixed to prepare a resin composition for electrical insulation.

Example 2
100 parts of an unsaturated polyester resin composition (a-1), 50 parts of silicon dioxide having an average particle diameter of 10 μm, 1 part of silicon dioxide having an average particle diameter of 20 nm of primary particles subjected to surface treatment with octylsilane, and titanium stearate 0 10 parts were stirred and mixed to prepare a resin composition for electrical insulation.

Comparative Example 1
A resin composition for electrical insulation was prepared by stirring and mixing 100 parts of an unsaturated polyester resin composition (a-1), 50 parts of silicon dioxide having an average particle diameter of 2 μm and 0.10 parts of titanium stearate.

Comparative Example 2
A resin composition for electrical insulation was prepared by stirring and mixing 100 parts of the unsaturated polyester resin composition (a-1) and 50 parts of silicon dioxide having an average particle diameter of 2 μm.

Comparative Example 3
100 parts of unsaturated polyester resin composition (a-1), 50 parts of silicon dioxide having an average particle diameter of 2 μm, 1 part of silicon dioxide having an average particle diameter of 20 nm of primary particles not subjected to surface treatment and 0.10 parts of titanium stearate Were mixed by stirring to prepare a resin composition for electrical insulation.

Comparative Example 4
100 parts of unsaturated polyester resin composition (a-1), 50 parts of silicon dioxide having an average particle diameter of 10 μm, 1 part of silicon dioxide having an average particle diameter of 20 nm of primary particles not subjected to surface treatment and 0.10 parts of titanium stearate Were mixed by stirring to prepare a resin composition for electrical insulation.

Comparative Example 5
A resin composition for electrical insulation was prepared using only 100 parts of the unsaturated polyester resin composition (a-1).

  Next, with respect to each of the obtained resin compositions for electrical insulation, the viscosity, variation, silicon dioxide sedimentation, thermal conductivity and dielectric constant of the electrical insulation resin composition were investigated. The results are shown in Table 1. The test method is as follows.

(1) Resin Composition Viscosity / Thickness Deflection Measured according to the test method of JIS C 2105.
(2) Precipitation property of silicon dioxide The varnish was put into a test tube having a diameter of 18 mm at a height of 100 mm, stored at room temperature for a predetermined period, and then the height of silicon dioxide relative to the height of the entire varnish was measured.

・ Normal state of precipitated silicon dioxide Place varnish in a mayonnaise bottle with a diameter of 60 mm at a height of 100 mm, store it at room temperature for a predetermined period, drop a glass rod with a diameter of 3 mm and a height of 200 mm, and the glass rod reaches the bottom of the mayonnaise bottle It was tested whether it reached. When the glass rod reached the bottom of the mayonnaise bottle, it was judged that there was no hard cake, and when the glass rod did not reach the bottom of the mayonnaise bottle, it was judged that there was a hard cake.

・ Redispersibility of settled silicon dioxide Place the varnish in a pail can with a diameter of 300 mm at a height of 200 mm, store it at room temperature for a specified period of time, and then use the four blades with a diameter of 20 mm at the center of the pail. Is set to 100 mm from the bottom, stirred for 1 hour at a speed of 1000 rpm, and can be redispersed when the precipitated silicon dioxide can be dispersed. Judgment was impossible.

-Thermal conductivity: A resin composition for electrical insulation is cast in a disk-shaped mold having a diameter of 50 mm and a thickness of 10 mm, and cured at a temperature of 150 ° C. for 3 hours to produce a test piece. It was measured using Dynatech Co., Ltd., Cimatec (trade name).

-Dielectric constant measurement A resin composition is apply | coated to a tin plate of 90 mm x 90 mm x 0.25 mm (t), and it carries out at 110 degreeC for 1.5 hours. This operation is performed four times to produce a cured resin coating film. This hardened | cured material was kept at 23 degreeC and the dielectric constant was measured based on JISC2105.
・ Measurement conditions Frequency: 50Hz, 1kHz, 1MHz, Main electrode: φ = 37mm aluminum foil

Claims (6)

  Unsaturated polyester (A) using α, β-unsaturated dibasic acid and alcohol having one or more hydroxyl groups as essential components, reactive diluent (B) having an unsaturated group in the molecule, alkylbenzene / formaldehyde resin (C), silicon dioxide (D) having an average particle diameter of 0.5 to 5 μm, hydrophobic silicon dioxide (E) having an average primary particle diameter of 500 nm or less, and a titanate coupling agent (F) are included as essential materials. Resin mixture for electrical insulation.   The resin mixture for electrical insulation according to claim 1, wherein the unsaturated polyester (A) has a molecular weight in the range of 1000 to 10,000.   The resin composition for electrical insulation according to claim 1 or 2, wherein the reactive monomer (B) having an unsaturated group in the molecule is contained in an amount of 50 to 200 parts by weight based on 100 parts by weight of the unsaturated polyester (A). object.   The resin for electrical insulation according to claim 1, 2 or 3, comprising 0.1 to 20 parts by weight of alkylbenzene / formaldehyde resin (C) with respect to 100 parts by weight of the resin composition for electrical insulation according to claim 3. Composition.   5 to 100 parts by weight of silicon dioxide (D) having an average particle diameter of 0.5 to 5 μm and an average particle diameter of primary particles of 500 nm or less with respect to 100 parts by weight of the resin composition for electrical insulation according to claim 4 The electrical insulation according to claim 1, 2, 3 or 4, comprising 0.001 to 10 parts by weight of hydrophobic silicon dioxide (E) and 0.01 to 1 part by weight of a titanate coupling agent (F). Resin composition.   An electrical device is coated with an electrical insulating resin composition containing a polymerization initiator and a stabilizer on the electrical insulating resin composition according to claim 1, 2, 3, 4 or 5, and cured. Manufacturing method of electrical equipment insulation.