JP2001152003A - Resin composition for electric insulation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition for electric insulation, having high thermal conductivity, low viscosity and slow precipitation rate of an inorganic filler. SOLUTION: This resin composition for the electric insulation comprises (A) an unsaturated polyester resin, (B) the inorganic filler and (C) a titanate- based coupling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition for electrical insulation, and more particularly, to a resin composition for electrical insulation that improves the heat dissipation of coils for electrical equipment such as motors and transformers.

[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, a transformer or a reactor coil used for an electric device such as a microwave oven or an inverter air conditioner stores heat without radiating heat generated by an excessive load during operation, and the temperature of the electric device increases. Therefore, in order to reduce the temperature rise due to heat generation, the resin composition for electrical insulation is required to have a high thermal conductivity and a high heat dissipation property to the atmosphere.

[0004] In view of this, in order to reduce the temperature rise due to the heat generated during the operation of electric equipment, an inorganic filler is added to the unsaturated polyester resin to increase the heat conductivity, and the heat dissipation to the atmosphere is reduced. Improved unsaturated polyester resins have been used. However, when an inorganic filler is mixed with an unsaturated polyester resin, the viscosity and the degree of thixotropicity increase, the resin composition does not sufficiently penetrate between the coil and the core, and vibration occurs due to insufficient adhesion between the coil and the core. was there. In addition, since the inorganic filler easily settles, there is a problem that cracks occur in the resin composition in the pool portion of the resin composition.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a resin composition for insulating electrical equipment, which has a high thermal conductivity, a low viscosity, and a slow sedimentation of an inorganic filler in order to satisfy the recent required performance. An object is to provide a resin composition for insulating electrical equipment.

[0006]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that by mixing an unsaturated polyester resin with an inorganic filler and a titanate-based coupling agent, the thermal conductivity of the unsaturated polyester resin is higher than that of the conventional unsaturated polyester varnish. It has been found that a resin composition having good radiation properties, low viscosity and slow sedimentation of the inorganic filler can be obtained.

That is, the present invention provides a resin composition for electrical insulation comprising (A) an unsaturated polyester resin, (B) an inorganic filler, and (C) a titanate coupling agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the unsaturated polyester resin which is the component (A) used in the present invention, those containing an unsaturated polyester (a) and a crosslinkable monomer (b) are preferably used. Can be

As the unsaturated polyester (a), a polybasic acid component composed of an unsaturated polybasic acid and a saturated polybasic acid and a polyhydric alcohol component are usually subjected to a dehydration condensation reaction, and if necessary, a modified component is added. What is obtained by reacting is used. The reaction of the modifying component may be performed simultaneously with the dehydration condensation reaction between the polybasic acid component and the polyhydric alcohol component,
After reacting a part of the polybasic acid component or the polyhydric alcohol component with the modified component, the reaction product may be added to carry out a dehydration condensation reaction of the remaining polybasic acid component and the polyhydric alcohol component.

Examples of unsaturated polybasic acids include unsaturated dibasic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, citraconic anhydride and reactive derivatives such as anhydrides thereof. And one or more of these can be used. Examples of the saturated polybasic acid include phthalic acid, phthalic anhydride,
Isophthalic acid, terephthalic acid, tetrahydrophthalic acid,
Aromatic carboxylic acids such as tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, adipic acid, sebacic acid, glutaric acid, tetrabromophthalic acid, trimellitic acid, pyromellitic acid, dimer acid, succinic acid, and azelaic acid , 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 can be used.

The amount of the unsaturated polybasic acid used is preferably from 50 to 95 mol%, more preferably from 70 to 90 mol%, based on the total moles of the polybasic acid component. If the amount of the unsaturated polybasic acid is less than 50 mol%, the curability tends to decrease, and if it exceeds 95 mol%, the strength of the cured product tends to decrease.

As the polyhydric alcohol component, for example, dihydric alcohols such as propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, 1,3-propanediol, 1,3- Chain dihydric alcohols such as butanediol, 1,4-butanediol and neopentyl glycol; alicyclic diols such as cyclopentanediol, cyclohexanediol and hydrogenated bisphenol A; bisphenol A propylene oxide adduct; p-xylene- Aromatic group-containing diols such as α, α'-diol, ethers such as pentaerythritol diallyl ether, and trihydric or higher polyhydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol. One or two of these
More than one species can be used.

The amount of the polyhydric alcohol component to be used is preferably 0.7 to 1.3 mol, more preferably 1.0 to 1.2 mol, per 1 mol of the polybasic acid component. If the amount of the polyhydric alcohol component is less than 0.7 mol or more than 1.3 mol per mol 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. The amount of the modifying component used is preferably 0 to 30% by weight of the polybasic acid component, and more preferably 15 to 30% by weight.

As the unsaturated polyester (a), those having a number average molecular weight (measured by gel permeation chromatography and converted using a standard polystyrene calibration curve) of from 500 to 2,000 are preferably used. It is more preferable to use those having an acid value of 800 to 1200, and the acid value is preferably 5 to 40, more preferably 10 to 20.

Examples of the crosslinkable monomer (b) include styrene, vinyltoluene, 2-methylstyrene, 3-methylstyrene, p-methylstyrene, α-methylstyrene, tert-butylstyrene, divinylbenzene,
Aromatic vinyl compounds such as chlorostyrene, dichlorostyrene, brominated styrene, etc .; carboxylic acid monovinyl esters such as vinyl pivalate, vinyl 2-ethylhexanoate, vinyl laurate, and vinyl benzoate; various (meth)
Acrylates such as neopentyl glycol dimethacrylate ((meth) acrylate means methacrylate or acrylate), pentaerythritol tetramethacrylate, dipentaerythritol tetramethacrylate, pentaerythritol hexamethacrylate, pentaerythritol hexaacrylate, trimethylolpropanetri (Meth) acrylates of polyhydric alcohols such as (meth) acrylates, alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate; glycidyl (meth) acrylate And allyl ethers such as various allyl esters such as allyl cyanurate and diallyl phthalate. These crosslinkable monomers (b) may be used alone or in combination of two or more.

The amount of the crosslinkable monomer (b) used is preferably from 75 to 40 parts by weight, more preferably from 60 to 40 parts by weight, based on 25 to 60 parts by weight of the unsaturated polyester (a). However, the total amount of the unsaturated polyester (a) and the crosslinkable monomer (b) is 100 parts by weight.

The inorganic filler of the component (B) used in the present invention is used for the purpose of improving the heat radiation during the operation of electric equipment.
The amount is preferably 10 to 100 parts by weight, more preferably 20 to 82 parts by weight based on 00 parts by weight. From the viewpoint of heat dissipation, the larger the amount, the better. However, if the amount is large, the viscosity of the resin composition for electrical insulation tends to be high, and the impregnating property tends to be low. For this reason, the amount of the inorganic filler (B) is preferably 100 parts by weight or less, more preferably 82 parts by weight or less, based on 100 parts by weight of the unsaturated polyester resin (A). Further, in order to sufficiently improve the heat radiation, the inorganic filler (B) is preferably at least 10 parts by weight, more preferably at least 20 parts by weight, further preferably at least 2 parts by weight.
Add 5 parts by weight or more. The amount of the inorganic filler (B) is 1
If the amount is less than 0 parts by weight, thermal conductivity tends to be low and heat radiation tends to be low.

As the inorganic filler (B), calcium carbonate, magnesium carbonate, barium carbonate, barium sulfate,
Examples thereof include calcium sulfate, aluminum hydroxide, aluminum oxide, silicon dioxide, clay, talc, kaolin and the like, and one or more of these can be used. The average particle size of the inorganic filler is preferably from 1 to 10 μm, more preferably from 2 to 8 μm.

The titanate-based coupling agent (C) used in the present invention reduces the viscosity of the resin composition, which is increased by the addition of the inorganic filler (B), and reduces the precipitation of the inorganic filler (B). It is blended for the purpose of reducing the speed. From the viewpoint of decreasing the viscosity, the viscosity of the resin composition decreases as the amount of the titanate-based coupling agent (C) increases, but when the amount of the titanate-based coupling agent (C) increases, the sedimentation of the inorganic filler (B) increases, The filler (B) separates. On the other hand, if the amount is too small, there is no effect in lowering the viscosity.

Accordingly, the amount of the titanate-based coupling agent (C) is preferably in the range of 0.01 to 10 parts by weight, and more preferably 0 to 10 parts by weight, based on 100 parts by weight of the unsaturated polyester resin (A). The range is more preferably from 0.02 to 1.0 part by weight.

Examples of titanate coupling agents include titanium stearate, di-i-propoxytitanium 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, if necessary, a curing agent (D) for the unsaturated polyester resin (A) can be blended. As the curing agent (D), any one can be used without particular limitation as long as it is generally used as a curing agent for an unsaturated polyester resin.
For example, benzoyl peroxide, acyl peroxide such as acetyl peroxide, tertiary butyl peroxide, hydroperoxide such as cumene hydroperoxide, methyl ethyl ketone peroxide,
Ketone peroxides such as cyclohexanone peroxide, dialkyl peroxides such as di-tert-butyl peroxide and dicumyl peroxide, and oxyperoxides such as tert-butyl peroxy acetate can be used. The addition amount of the curing agent (D) is preferably from 0.3 to 5 parts by weight based on 100 parts by weight of the total amount of the components (A), (B) and (C).
0.5 to 2 parts by weight is more preferred.

[0024] If necessary, a curing accelerator and a polymerization inhibitor may be added. The curing accelerator and polymerization inhibitor can be used without any particular limitation as long as they are commonly used for curing unsaturated polyester resins.
For example, as a curing accelerator, manganese naphthenate, lead naphthenate, cobalt naphthenate, cobalt octenoate, and the like can be used.As the polymerization inhibitor, for example,
Quinones such as hydroquinone, tertiary butyl catechol and p-benzoquinone can be used.

The resin composition of the present invention is applied to the insulation treatment of motors for air conditioner fans, electric fans, washing machines and the like, power transformers for televisions, stereos, compact disc players and the like.

[0026]

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 middle part in the following examples means parts by weight.

Production Example 1 Unsaturated polyester (a-1)
330 parts of dicyclopentadiene (parts by weight, the same applies hereinafter),
230 parts of maleic anhydride and 42 parts of water were charged into a reaction vessel, and reacted at 140 ° C. for 2 hours under a nitrogen gas stream.
Dicyclopentadienyl monomalate was synthesized. Next, 170 parts of ethylene glycol, 1100 parts of diethylene glycol, 750 parts of maleic anhydride, and 290 parts of terephthalic acid were charged into a reaction vessel, and the reaction mixture was placed in a nitrogen gas stream at 200 to 200 parts.
The temperature was raised to 220 ° C., and the temperature was maintained in this range to cause a dehydration condensation reaction. When the acid value reached 20, the mixture was cooled.
The number average molecular weight of the obtained unsaturated polyester is 1,000.
Met.

Synthesis of unsaturated polyester (a-2) 330 parts of dicyclopentadiene (parts by weight, the same applies hereinafter);
230 parts of maleic anhydride and 42 parts of water were charged into a reaction vessel and reacted at 140 ° C. for 2 hours under a nitrogen gas stream.
Dicyclopentadienyl monomalate was synthesized. Next, 1400 parts of diethylene glycol, 750 parts of maleic anhydride, and 290 parts of terephthalic acid were charged into a reaction vessel, and the temperature was raised to 200 to 220 ° C. in a stream of nitrogen gas. When the acid value reached 20, the mixture was cooled. The number average molecular weight of the obtained unsaturated polyester was 950.

Example 1 45 parts of unsaturated polyester (a-1), styrene 35
Parts, 20 parts of silicon dioxide having an average particle size of 4 μm, 0.05 parts of titanium stearate, and 1.0 part of the total amount of unsaturated polyester (a-1) and styrene as a curing agent.
By weight, benzoyl peroxide was stirred and mixed to prepare a resin composition for electrical insulation.

Example 2 30 parts of unsaturated polyester (a-1), 30 parts of styrene
Parts, 40 parts of silicon dioxide having an average particle diameter of 4 μm, 0.05 parts of titanium stearate, and 1.0 part with respect to the total amount of the unsaturated polyester (a-1) and styrene as a curing agent.
By weight, benzoyl peroxide was stirred and mixed to prepare a resin composition for electrical insulation.

Example 3 45 parts of unsaturated polyester (a-1), 35 parts of styrene
Parts, 20 parts of silicon dioxide having an average particle diameter of 8 μm, 0.1 part of titanium stearate, and 1.0% by weight of benzoyl peroxide as a curing agent based on the total amount of the unsaturated polyester (a-1) and styrene. The resin composition for electrical insulation was prepared by stirring and mixing.

Example 4 30 parts of unsaturated polyester (a-1), styrene 30
Parts, 40 parts of silicon dioxide having an average particle size of 8 μm, 0.1 part of titanium stearate, and 1.0% by weight of benzoyl peroxide based on the total amount of unsaturated polyester (a-1) and styrene as a curing agent. The resin composition for electrical insulation was prepared by stirring and mixing.

Example 5 A resin composition for electrical insulation was prepared in the same manner as in Example 3 except that the unsaturated polyester (a-2) was used instead of the unsaturated polyester (a-1).

Example 6 A resin composition for electrical insulation was prepared in the same manner as in Example 4 except that the unsaturated polyester (a-2) was used instead of the unsaturated polyester (a-1).

Comparative Example 1 30 parts of unsaturated polyester (a-1), styrene 30
Parts, 40 parts of silicon dioxide having an average particle diameter of 8 μm, and benzoyl peroxide of 1.0% by weight based on the total amount of the unsaturated polyester (a-1) and styrene as a curing agent, and mixed by stirring. A composition was prepared.

Comparative Example 2 50 parts of unsaturated polyester (a-1), 50 parts of styrene
Parts and benzoyl peroxide of 1.0% by weight based on the total amount of unsaturated polyester (a-1) and styrene as a curing agent were stirred and mixed to prepare a resin composition for electrical insulation.

Comparative Example 3 45 parts of unsaturated polyester (a-1), 35 parts of styrene
Parts, 20 parts of silicon dioxide having an average particle size of 4 μm, and benzoyl peroxide of 1.0% by weight with respect to the total amount of the unsaturated polyester (a-1) and styrene as a curing agent, and mixed by stirring. A composition was prepared.

Comparative Example 4 An electrically insulating resin composition was prepared in the same manner as in Comparative Example 3 except that the unsaturated polyester (a-2) was used instead of the unsaturated polyester (a-1).

With respect to the obtained resin composition for electrical insulation,
The viscosity, thixotropic property, sedimentation property of the inorganic filler, gel time, thermal conductivity, and the rise in operating temperature of the transformer electrically insulated using this resin composition for electrical insulation were examined. Table 1 shows the results.

The test methods for these characteristics are as follows.

Viscosity, thixotropicity, and gel time of the resin composition for electrical insulation: Measured according to JIS C 2105.

Sedimentability of inorganic filler: The resin composition for electrical insulation was placed in a test tube having a diameter of 18 mm at a height of 100 mm, left at 40 ° C., and the height of a clear layer formed on the top was measured. .

Thermal conductivity: A 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 was cured at a temperature of 150 ° C. for 3 hours to prepare a test piece. The measurement was performed using a measuring device (Cymatech (trade name) manufactured by Dynatech Co., Ltd.).

Temperature rise during operation: core size 83 mm × 8
A temperature sensor was attached to the inside of a 0 mm × 50 mm transformer core, and the resin composition for electrical insulation was heated at room temperature to 133 hPa.
And cured at 160 ° C. for 3 hours.
After cooling, measure the temperature of the transformer and apply 100V
The temperature after time application was measured again, and the temperature rise was determined from the temperature difference before and after voltage application.

Crack: Ten enamel wires having a diameter of 1.0 mm were bundled, bent in a U-shape, coated with a resin composition for electrical insulation, and cured at 170 ° C. for 1 hour to obtain a test piece. This test piece was subjected to a heat cycle at 100 ° C. for 1 hour and at −30 ° C. for 1 hour, and cracks generated in the resin composition for electrical insulation were observed. Table 1 shows the number of cycles when occurrence of cracks was observed.

[0046]

[Table 1] As can be seen from Table 1, the resin composition for electrical insulation of Examples of the present invention contains an inorganic filler, and thus has a higher thermal conductivity than Comparative Example 2 containing no inorganic filler. Has become. Further, Examples 1 to 6 were compared with Comparative Examples 1, 3, and 4, particularly, Example 1 and Comparative Example 3, and Example 4 and Comparative Example 1.
As can be seen from the comparison, the resin composition for electrical insulation of the present invention in which a titanate-based coupling agent is blended in addition to the inorganic filler is more inorganic than the comparative example in which the titanate-based coupling agent is not blended. The increase in viscosity due to the blending of the filler is low, and the thixotropic property is low. Therefore, the impregnation into the transformer coil is excellent, and the temperature rise of the treated transformer during operation is small. Furthermore, since there is almost no sedimentation of the inorganic filler, it is understood that the inorganic filler does not excessively accumulate in the varnish pool portion, so that crack resistance can be significantly improved.

[0047]

The electrical insulation resin composition of the present invention is impregnated into an electrical equipment for insulation treatment, whereby an electrical equipment excellent in heat dissipation and crack resistance can be manufactured.

Claims (4)

[Claims] 1. An unsaturated polyester resin (A), (B)
A resin composition for electrical insulation comprising an inorganic filler and (C) a titanate coupling agent. 2. (A) 100 parts by weight of an unsaturated polyester resin, (B) 10 to 100 parts by weight of an inorganic filler, and (C)
The resin composition for electrical insulation according to claim 1, comprising 0.01 to 10 parts by weight of a titanate-based coupling agent. 3. The resin composition according to claim 1, wherein the unsaturated polyester resin (A) comprises an unsaturated polyester and a crosslinkable monomer. 4. The resin composition for electrical insulation according to claim 1, further comprising a curing agent for the unsaturated polyester resin (A).