JP2001256830A - Resin composition for electric insulation and electric equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for electrical insulation having a good ability to get impregnated into an electric equipment at a low viscosity and thixotropy and a high coefficient of thermal conductivity and an ability to facilitate dissipating heat generated during the operation of an electric equipment and with an inorganic filler allowing to be left for days made to have a considerably slow sedimentation rate, and an electric equipment electrically insulated by using the resin composition for electrical insulation. SOLUTION: A resin composite matter for electrical insulation contains an unsaturated polyester resin, silica with an average particle diameter of 0.5 to 5 μm, and a titanate coupling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for electric insulation and electric equipment, and more particularly to a coil for electric equipment such as a motor and a transformer, which is mainly composed of a mixture of an unsaturated polyester resin and an inorganic filler. TECHNICAL FIELD The present invention relates to a resin composition for electrical insulation that improves the heat radiation property of an electric device, and to an electrical device that is subjected to an electrical insulation treatment using the resin composition for electrical insulation.

[0002]

2. Description of the Related Art Electric devices such as motors and transformers are treated with a resin composition for electric insulation for the purpose of fixing or rustproofing an iron core, insulating or fixing a coil, and the like. As the resin composition for electrical insulation, an unsaturated polyester resin composition excellent in balance among curability, air-drying property, sticking property, electrical insulation property, economy and the like is widely used.

[0003] In recent years, electric appliances have been increasing in heat storage temperature due to progress in miniaturization, weight reduction and high output. In particular, transformers and reactor coils used in electric equipment such as microwave ovens and inverter air conditioners tend to store heat without dissipating heat generated by an excessive load during operation and increase the temperature of the electric equipment, Each of the materials used has been required to have higher heat resistance. Therefore, while increasing the thermal conductivity of the resin composition,
In order to improve the impregnation property of the resin composition into the coil and the heat dissipation property of the electric device, a resin composition having improved heat dissipation property in the air atmosphere is required. Further, when the constituent members of the electric device are the same, use of such a resin composition can contribute to improvement in reliability of the electric device.

[0004] As described above, in order to increase the thermal conductivity and improve the impregnation property of electric equipment, an unsaturated polyester resin mixed with an unsaturated polyester resin obtained by adding an inorganic filler to an unsaturated polyester resin is used. I have been. But,
When the inorganic filler is mixed with the unsaturated polyester resin, the mixed inorganic filler sediments due to standing over time, and the unsaturated polyester resin and the inorganic filler are separated. Furthermore, the heat dissipation and crack resistance of electric equipment may become a problem due to the variation in the mixing ratio between the unsaturated polyester resin and the inorganic filler.

[0005] When the amount of the inorganic filler in the resin composition for electrical insulation is increased, the viscosity and the degree of thixotropicity are increased, the impregnating property to electric equipment is reduced, the heat dissipation is reduced, and the cured product film becomes thick. In addition, there is a problem that cracks are easily generated, and when the amount of the inorganic filler in the resin composition for electrical insulation is small, impregnation is good, but the thermal conductivity of the resin is reduced, so that There is a problem that the heat radiation of the device is reduced.

[0006]

SUMMARY OF THE INVENTION In order to satisfy recent performance requirements, an electric insulating resin composition has a low viscosity, a low thixotropic degree, a high thermal conductivity, and an inorganic filler obtained by leaving it for days. There has been a demand for a resin composition for electrical insulation whose sedimentation speed has been considerably reduced.

[0007] The present invention has a low viscosity, a low volatility, a good impregnating property to electric equipment, a high thermal conductivity, and can easily dissipate heat generated during operation of electric equipment. An object of the present invention is to provide a resin composition for electrical insulation in which the sedimentation rate of an inorganic filler caused by standing for a day is considerably slowed down, and an electrical device which is subjected to an electrical insulation treatment using the resin composition for electrical insulation.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that an unsaturated polyester resin has an average particle size of 0.5 to 5 μm.
m of silicon dioxide and a titanate-based coupling agent, the sedimentation rate of silicon dioxide is higher than that of a case where a conventional unsaturated polyester resin is mixed with silicon dioxide and a titanate-based coupling agent having an average particle size of more than 5 μm. It has been found that, even after leaving the resin composition for days, the impregnating property of the electric device is good, so that the heat dissipation of the electric device during operation is good, and the temperature rise of the electric device can be reduced. .

The present invention relates to an electrically insulating resin composition comprising (A) an unsaturated polyester resin, (B) silicon dioxide having an average particle size of 0.5 to 5 μm, and (C) a titanate coupling agent. .

[0010] The present invention also relates to an electric device which is insulated by using the resin composition for electric insulation treatment.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As the unsaturated polyester resin which is the component (A) used in the present invention, a resin containing an unsaturated polyester and a crosslinkable monomer is usually suitably used. As the unsaturated polyester, usually, a polyester obtained by subjecting a polybasic acid component composed of an unsaturated polybasic acid and a saturated polybasic acid to a dehydration condensation reaction with a polyhydric alcohol component, and further reacting a modified component as necessary. Is used.
The reaction of the denaturing component may be performed simultaneously with the dehydration condensation reaction between the polybasic acid component and the polyhydric alcohol component, or after reacting a part of the polybasic acid component or the polyhydric alcohol component with the denaturing component, The dehydration condensation reaction of the remaining polybasic acid component and polyhydric alcohol component may be performed by adding the reaction product.

The unsaturated polybasic acids include, for example, unsaturated dibasic acids such as maleic acid, maleic anhydride and fumaric acid, and reactive derivatives such as anhydrides thereof. More than one species can be used.
Examples of the saturated polybasic acid include aromatic acids such as phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, adipic acid, and sebacic acid. Examples thereof include carboxylic acids, saturated acids, reactive derivatives such as anhydrides thereof, and vegetable oil fatty acids such as soybean oil fatty acids, linseed oil fatty acids, and tall oil fatty acids, and one or more of these may be used. it can.

The amount of the unsaturated polybasic acid used is preferably 30 to 80 mol%, more preferably 50 to 70 mol%, based on the total number of moles of the polybasic acid component. If the amount of the unsaturated polybasic acid is less than 30 mol%, the curability tends to decrease, and if it exceeds 80 mol%, the stability tends to deteriorate.

Examples of the polyhydric alcohol component include dihydric alcohols such as propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, 1,3-butanediol, and neopentyl glycol.
Glycerin, trimethylolpropane, trihydric or higher polyhydric alcohols such as pentaerythritol, and the like,
One or more of these can be used.

The amount of the polyhydric alcohol component used is preferably 1.00 to 1.30 equivalents, more preferably 1.05 to 1.15 equivalents, per equivalent of the polybasic acid component. When the use amount of the polyhydric alcohol component is less than 1.00 equivalent or more than 1.30 equivalent per equivalent of the polybasic acid component, the unsaturated polyester does not have a high molecular weight, and a resin composition having sufficient strength cannot be obtained. Tend.

Examples of the modified components include linseed oil, soybean oil, tall oil, dehydrated castor oil, coconut oil, dicyclopentadiene, cyclopentadiene, and the like. One or more of these are used. be able to.

As the unsaturated polyester, a number average molecular weight (measured by gel permeation chromatography and converted using a standard polystyrene calibration curve)
Is preferably 100 to 100,000, and more preferably 1,000 to 50,000. Further, the acid value is preferably from 10 to 25.

Examples of the crosslinkable monomer include styrene,
Vinyl toluene, α-methylstyrene, tertiary butylstyrene, aromatic vinyl compounds such as divinylbenzene, various acrylates such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate and And / or various allyl esters such as methacrylic acid ester and diallyl phthalate, and various allyl ethers.
These crosslinkable monomers may be used alone,
Two or more kinds may be used in combination.

The amount of the crosslinking monomer used is preferably 75 to 40 parts by weight based on 25 to 60 parts by weight of the unsaturated polyester.
Parts by weight, more preferably 35 to 50 unsaturated polyester
The range is 65 to 50 parts by weight with respect to parts by weight. However, the total amount of the unsaturated polyester and the crosslinkable monomer is 1
00 parts by weight.

The average particle size of the silicon dioxide as the component (B) used in the present invention is 0.5 to 5 μm, preferably 1 to 4 μm, more preferably 2 to 3 μm. When the average particle size of silicon dioxide exceeds 5 μm, with standing for days, silicon dioxide is likely to settle, the temperature rise during the operation of the transformer becomes large, and when it is less than 0.5 μm, the degree of thixotropic becomes high, The impregnating property of the coil is reduced.
The average particle size can be measured using a particle size distribution measuring device (manufactured by Shimadzu Corporation).

[0021] Silicon dioxide (B) having an average particle size of 0.5 to 5 µm is blended mainly for the purpose of improving heat dissipation when operating electric equipment. From the viewpoint of heat dissipation, the larger the amount, the better. However, the higher the amount, the higher the viscosity and thixotropic degree of the resin composition for electrical insulation, and the lower the impregnation. For this reason, the average particle size of 0.1 part by weight based on 100 parts by weight of the unsaturated polyester resin (A)
The amount of silicon dioxide (B) of 5 to 5 μm is usually 10 to 1
00 parts by weight, preferably 25 to 82 parts by weight, more preferably 43 to 66 parts by weight. Average particle size 0.5-5
If the amount of the silicon dioxide (B) of less than 10 μm is less than 10 parts by weight, the thermal conductivity tends to be low and the heat dissipation tends to be low.

The titanate-based coupling agent (C) used in the present invention has a resin composition having an average particle diameter of 0.5 to 5 μm. It is blended for the purpose. From the viewpoint of decreasing the viscosity and thixotropic degree, the viscosity and thixotropic degree of the resin composition decrease as the amount of the titanate-based coupling agent (C) increases, but the viscosity decreases as the amount increases. Too fast, the sedimentation of the silicon dioxide is faster and the silicon dioxide tends to separate. On the other hand, if the amount is too small, there is no effect on lowering the viscosity and thixotropic degree.

Accordingly, the amount of the titanate-based coupling agent (C) is preferably in the range of 0.01 to 1.0 part by weight based on 100 parts by weight of the unsaturated polyester resin (A). A range of 0.02 to 0.2 parts by weight is more preferable.

Examples of titanate coupling agents include titanium stearate, di-i-proxytitanium diisostearate, (2-n-butoxycarbonylbenzoyloxy) tributoxytitanium, and 2-ethylhexanoyloxytri (2- Propoxy) titanium (both manufactured by Nippon Soda Co., Ltd.) and the like, and one or more kinds can be used.

The resin composition for electrical insulation according to the present invention includes:
Further, a curing agent for the unsaturated polyester resin can be blended if necessary. As the curing agent, any one can be used without particular limitation as long as it is generally used as a curing agent for an unsaturated polyester resin.Examples include acyl peroxides such as benzoyl peroxide and acetyl peroxide, tertiary butyl peroxide, and cumene. Hydroperoxides such as hydroperoxides,
Ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, dialkyl peroxides such as di-tert-butyl peroxide and dicumyl peroxide, and oxyperoxides such as tert-butyl peroxy acetate can be used. As the addition amount of the curing agent, the component (A)
The amount is preferably from 0.3 to 5 parts by weight, more preferably from 0.5 to 1 part by weight, based on 100 parts by weight of the total of the components (B) and (C).

If necessary, an accelerator and a polymerization inhibitor can be added. The accelerator and polymerization inhibitor can be used without any particular limitation as long as they are generally used for curing the unsaturated polyester resin. For example, manganese naphthenate, lead naphthenate, cobalt naphthenate, cobalt octenoate, and the like can be used as the accelerator. As the polymerization inhibitor, for example, quinones such as hydroquinone, tert-butylcatechol, and p-benzoquinone can be used.

[0027] The resin composition of the present invention comprises a fan for an air conditioner,
It is applied to the insulation treatment of electric equipment such as condenser motors such as electric fans and washing machines, and power transformers such as televisions, stereos and compact disc players.

[0028]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited by these examples. In addition, the part in the following examples means a weight part.

Production Example 1 Unsaturated polyester (a-1)
784 parts of maleic anhydride, 166 parts of terephthalic acid, 166 parts of isophthalic acid, 847 parts of diethylene glycol, and 186 parts of ethylene glycol were charged into a reaction vessel, and the temperature was raised to 200 to 220 ° C. in a stream of nitrogen gas. After adding 528 parts of cyclopentadiene, a dehydration-condensation reaction was carried out by a conventional method. When the acid value reached 20, the mixture was cooled.
The resulting unsaturated polyester had a number average molecular weight of 35.0.
00.

Example 1 45 parts of unsaturated polyester (a-1), styrene 35
Parts, 40 parts of silicon dioxide having an average particle size of 2 μm, 0.10 parts of titanium stearate, and 1.0% by weight of benzoyl peroxide, based on the total amount of unsaturated polyester and styrene, as a curing agent, and mixed by stirring. A varnish of the resin composition was prepared.

Example 2 45 parts of unsaturated polyester (a-1), 35 parts of styrene
Parts, 40 parts of silicon dioxide having an average particle size of 4 μm, 0.10 parts of titanium stearate, and 1.0% by weight of benzoyl peroxide, based on the total amount of unsaturated polyester and styrene, as a curing agent were mixed with stirring for electrical insulation. A varnish of the resin composition was prepared.

Comparative Example 1 45 parts of unsaturated polyester (a-1), styrene 35
Parts, 40 parts of silicon dioxide having an average particle size of 8 μm, 0.10 parts of titanium stearate, and 1.0% by weight of benzoyl peroxide based on the total amount of unsaturated polyester and styrene as a curing agent, and mixed by stirring. A varnish of the resin composition was prepared.

Comparative Example 2 Unsaturated polyester (a-1) 45 parts, styrene 35
Parts, 40 parts of silicon dioxide having an average particle diameter of 10 μm, 0.10 parts of titanium stearate, and 1.0% by weight of benzoyl peroxide based on the total amount of unsaturated polyester and styrene as a curing agent, and mixed by stirring. A varnish of the resin composition was prepared.

Regarding the varnish of the obtained resin composition for electric insulation, the varnish viscosity, degree of thixotropicity, silicon dioxide and the varnish of the resin composition for electric insulation were initially set immediately after the preparation of the varnish and left after standing at 40 ° C. for 10 days. Of the transformer, and the temperature rise and impregnation during the operation of the transformer electrically insulated using the varnish of the resin composition for electrical insulation were examined. Table 1 shows the results.

The test methods for these characteristics are as follows. Varnish viscosity, thixotropic degree: Measured according to JIS C 2105. Precipitation of silicon dioxide: The varnish was placed in a test tube having a diameter of 18 mm up to a height of 100 mm, left at 23 ° C. for 20 days, and the height of a clear layer formed on the top was measured. Thermal conductivity: A varnish of the resin composition for electrical insulation was cast into a disk-shaped mold having a diameter of 50 mm and a thickness of 10 mm, and the temperature was adjusted to 15 ° C.
The test piece was prepared by curing at 0 ° C. for 3 hours, and the test piece was measured using a thermal conductivity measuring device (Cymatec (trade name) manufactured by Dynatech Co., Ltd.). Temperature rise during operation: Core dimensions 83 mm x 80 mm x 50
A temperature sensor was attached to the inside of the core of the transformer of mm, and a varnish of the resin composition for electric insulation was injected at room temperature under a reduced pressure of 133 hPa, and cured at 160 ° C. for 3 hours. After cooling, the temperature of the transformer was measured, the temperature after applying a voltage of 100 V for 2 hours was measured again, and the temperature rise was determined from the temperature difference before and after the voltage was applied. Regarding the impregnating property, the secondary coil was cut, the space between the enameled wires on the coil cross section was observed with a stereoscopic microscope, and the impregnation state of the resin composition was evaluated.

[0036]

[Table 1] As can be seen from Table 1, the varnish of the resin composition for electrical insulation according to the example of the present invention is obtained by mixing an unsaturated polyester resin with silicon dioxide having an average particle size of 0.5 to 5 μm and a titanate coupling agent. In addition, since the sedimentation speed of silicon dioxide can be reduced, the impregnating property of electrical equipment is good even after the varnish is left for days. Therefore, the heat dissipation of the electric device during operation is good, and the temperature rise of the electric device can be reduced.

[0037]

The resin composition for electrical insulation according to the present invention comprises:
By impregnating and insulating the electrical equipment, it is possible to manufacture electrical equipment with excellent heat dissipation, and even after the resin composition has been left for days, the impregnation property of the electrical equipment is good. The heat dissipation of the electric device at the time is good, and the temperature rise of the electric device can be reduced.

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Claims (3)

[Claims] 1. An unsaturated polyester resin (A), (B)
A resin composition for electrical insulation, comprising silicon dioxide having an average particle size of 0.5 to 5 μm and (C) a titanate coupling agent. 2. Silicon dioxide 1 having (A) 100 parts by weight of an unsaturated polyester resin and (B) an average particle size of 0.5 to 5 μm.
A resin composition for electrical insulation comprising 0 to 100 parts by weight and (C) 0.01 to 1.0 part by weight of a titanate coupling agent. 3. An electric device which is subjected to an electric insulation treatment using the resin composition for electric insulation according to claim 1 or 2.