JP6759139B2 - Resin composition for coil impregnation and coil for automobile motor - Google Patents

Description

The present invention relates to a resin composition for impregnating a coil and a coil for an automobile motor.

Unsaturated polyester resin is widely used as a resin used for electric / electronic parts (coils) used in automobile parts, general household appliances, industrial electric devices, etc. from the viewpoint of heat resistance, electric insulation, and curability. ing. Styrene was generally used as the reactive diluent for the unsaturated polyester resin.

However, when styrene was used as the reactive diluent, the odor was terrible, and the number of private houses increased near the factory where the coil was manufactured. In recent years, odor problems have frequently occurred, and improvement has been sought. ..

Therefore, acrylic acid esters such as acrylic acid or methacrylic acid are often used instead of styrene (see, for example, Patent Document 1). Among them, from the viewpoint of cost, it was common to use -2-hydroxyethyl methacrylate (2-HEMA).

However, since 2-HEMA has a free hydroxyl group, it has a drawback of causing crazing (hair crack) in the magnet wire to be treated (particularly, amidimide wire), and improvement thereof has been required.

To solve this problem, a method of using a diacrylate derivative of polyalkylene oxide as a reactive diluent has been reported (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2013-101863 Japanese Unexamined Patent Publication No. 2005-285791

However, in recent years, electric vehicles including hybrid cars are required to have high output and high rotation, and the amount of heat generated in the coil is also increasing. Further, since the resin composition for coil impregnation described in Patent Document 2 is exposed to various oils, its hydrolysis resistance is low , and its heat resistance and oil resistance are inferior.

The present invention has been made in view of such circumstances, and is a coil capable of obtaining a cured product having improved crazing resistance and hydrolysis resistance, excellent heat resistance and oil resistance, and high adhesive strength. It is an object of the present invention to provide a resin composition for impregnation and a coil for an automobile motor obtained by impregnating the resin composition for impregnating a coil with a coil portion.

As a result of diligent studies to solve the above problems, the present inventors have (B) a polyethylene terephthalate-modified unsaturated polyester resin and (C) a specific polyalkylene as a reactive diluent in the resin composition for impregnating the coil. It has been found that the above-mentioned problems can be solved by containing a di (meth) acrylate derivative of oxide.
The present invention has been completed based on such findings.

That is, the disclosure of the present application relates to the following.
[1] A resin composition for impregnating a coil, which comprises (A) an epoxy ester resin, (B) a polyethylene terephthalate-modified unsaturated polyester resin, (C) a reactive diluent, and (D) an organic peroxide. The number average molecular weight of polyethylene terephthalate used in the (B) polyethylene terephthalate modified unsaturated polyester resin is 20,000 to 60,000, and the mass ratio of the polyethylene terephthalate component contained in the total amount of the resin composition is A resin for impregnating a coil, which is 0.5 to 5.0%, and the (C) reactive diluent is a di (meth) acrylate derivative of a polyalkylene oxide having a number average molecular weight of 250 to 2,000. Composition.
[2] The resin composition for coil impregnation according to the above [1], which further contains (c-1) a tri (meth) acrylate compound.
[3] The above-mentioned [2], wherein the content ratio of the (c-1) tri (meth) acrylate compound is 2 to 20 parts by mass with respect to 100 parts by mass of the (C) reactive diluent. The resin composition for impregnating a coil according to the above.
[4] A coil for an automobile motor obtained by impregnating a coil portion with the resin composition for impregnating a coil according to any one of the above [1] to [3].

According to the present invention, a resin composition for coil impregnation, which has improved crazing resistance and hydrolysis resistance, is excellent in heat resistance and oil resistance, and can obtain a cured product having high adhesive strength, and for the coil impregnation. It is possible to provide a coil for an automobile motor obtained by impregnating a resin composition with a coil portion.

Hereinafter, the present invention will be described in detail.
<Resin composition for coil impregnation>
The resin composition for coil impregnation of the present invention is a coil impregnation containing (A) epoxy ester resin, (B) polyethylene terephthalate modified unsaturated polyester resin, (C) reactive diluent, and (D) organic peroxide. The polyethylene terephthalate used in the (B) polyethylene terephthalate-modified unsaturated polyester resin has a number average molecular weight of 20,000 to 60,000 and is contained in the total amount of the resin composition. The mass ratio of the polyethylene terephthalate component is 0.5 to 5.0%, and the (C) reactive diluent is a di (meth) acrylate derivative of a polyalkylene oxide having a number average molecular weight of 250 to 2,000. It is characterized by.

First, each component of the coil impregnating resin composition of the present invention (hereinafter, also simply referred to as “resin composition”) will be described.
[(A) Epoxy ester resin]
The epoxy ester resin of the component (A) used in the present invention is obtained by reacting an acid component and an epoxy component with an esterification catalyst, and has at least one carbon-carbon double bond at the terminal.

Examples of the acid component used here include unsaturated monobasic acids such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid and sorbic acid, and if necessary, phthalic acid, phthalic anhydride, isophthalic acid and terephthalic acid. , Tetrahydrophthalic acid, tetrahydrophthalic acid anhydride, hexahydrophthalic acid, hexahydrophthalic acid anhydride, adipic acid and other dibasic acids can be mixed and used.

The epoxy component used here may be one having two or more epoxy groups in one molecule, and can be widely used without any particular limitation on the molecular structure, molecular weight and the like. From the viewpoint of environmental protection, an epoxy resin containing no halogen element is preferable. Specifically, an epoxy resin having a bisphenol A type, a bisphenol F type, a novolak type, or a biphenyl type aromatic group, and a polycarboxylic acid are glycidyl ethers. Examples thereof include a modified epoxy resin and an epoxy resin having an alicyclic group in which an epoxy group is condensed with a cyclohexane derivative. These epoxy resins can be used alone or in combination of two or more.

In addition to these, as the epoxy component, a liquid monoepoxy resin or the like can be used as a combined component, if necessary.

The acid component is used in a molar ratio of the carboxy group of the acid component to the epoxy group of the epoxy component, preferably in the range of 80 to 120%, more preferably in the range of 90 to 110%. By setting the content within the above range, unreacted components can be suppressed, and the heat resistance and oil resistance of the resin composition can be improved.

Examples of the esterification catalyst used here include various phosphorus-containing compounds such as triphenylphosphine and tributylphosphine; various tertiary amines such as N, N-benzyldimethylamine, N, N-dimethylphenylamine and triethylamine; Various quaternary compounds such as ammonium salts, quaternary phosphonium salts and quaternary pyridinium salts; chlorides such as zinc chloride, aluminum chloride and tin chloride; and organometallic compounds such as tetrabutyl titanate can be used.

The blending amount of the esterification catalyst is preferably 0.05 to 1.0 part by mass with respect to 100 parts by mass in total of the acid component and the epoxy component. If it is 0.05 part by mass or more, the reaction time can be shortened, and if it is 1.0 part by mass or less, the reaction rate can be suppressed from becoming too fast, and preparation becomes easy.

The method for producing the epoxy ester resin as the component (A) is not particularly limited, and the epoxy ester resin may be produced by a conventionally known method. To give an example of the method for preparing the component (A), for example, an esterification catalyst is added in the presence of an epoxy component and an acid component, a polymerization inhibitor is added as necessary, and the epoxy ester is heated and stirred. Resin is obtained.

The acid value of the epoxy ester resin of the component (A) is preferably 2 to 20, more preferably 4 to 10. When the acid value is 2 or more, the reaction can be easily controlled and gelation can be suppressed, and when the oxidation is 20 or less, the residual amount of unreacted material can be suppressed.
To measure the acid value, weigh the sample into a flask, add a mixed solution of xylene, ethylbenzene, and ethanol, add a few drops of cresol red indicator to the solution, and use a 0.1 mol / L ethanolic potassium hydroxide solution. It was titrated and calculated.

The content of the component (A) contained in the total amount of the resin composition is preferably 30 to 50% by mass, more preferably 35 to 45% by mass.

[(B) Polyethylene terephthalate modified unsaturated polyester resin]
The polyethylene terephthalate-modified unsaturated polyester resin of the component (B) used in the present invention has a carbon-carbon double bond and a rigid polyethylene terephthalate skeleton in the main chain of the polyester structure, and therefore is a cured product of the resin composition. It has the effect of improving heat resistance and oil resistance.
The component (B) can be obtained by transesterifying a mixture of polyethylene terephthalate and an alcohol component to modify the polyethylene terephthalate, reacting the polyethylene terephthalate with the acid component, and esterifying the mixture. The alcohol component is preferably a divalent alcohol, and the acid component is preferably a divalent acid.

The number average molecular weight (Mn) of polyethylene terephthalate used here is preferably 20,000 to 60,000, more preferably 35,000 to 50,000. When the number average molecular weight (Mn) is 20,000 or more, heat resistance and oil resistance can be improved, and when it is 60,000 or less, the solubility of polyethylene terephthalate is not extremely low, and the component (B) Is easier to prepare.

Examples of the alcohol component used here include propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, 1,3-butanediol, neopentyl glycol, glycerin, pentaerythritol, tris (2-hydroxyethyl) isocyanurate, and polyether. Examples include polyalcohol. Among them, dihydric alcohol is preferable, and diethylene glycol, propylene glycol, and neopentyl glycol are more preferably used from the viewpoint of accelerating the transesterification reaction and obtaining the desired polyethylene terephthalate-modified unsaturated polyester resin. These can be used alone or in combination of two or more.
The amount of the alcohol component is preferably 30 to 250 parts by mass, more preferably 50 to 200 parts by mass with respect to 100 parts by mass of polyethylene terephthalate.

Examples of the modifying component that can be used in addition to the alcohol component include linseed oil, soybean oil, tall oil, petroleum resin, dicyclopentadiene and the like. These can be used alone or in combination of two or more.

The catalyst for the transesterification reaction can be used without particular limitation as long as it is a catalyst that causes a transesterification reaction, and examples thereof include tetraalkyl titanate, lead acetate, and dibutyltin dilaurate.

The acid components used here include unsaturated acids such as maleic acid, phthalic anhydride, fumaric acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, and tetrahydrophthalic anhydride; hexahydrophthalic acid. Saturated acids such as acids, phthalic anhydride and adipic acid can be mentioned. Of these, maleic acid, maleic anhydride, and fumaric acid are preferable, and maleic anhydride is more preferably used. These can be used alone or in combination of two or more.
The acid component is preferably blended so that the molar ratio (carboxy group / hydroxyl group) of the carboxy group of the acid component to the hydroxyl group of the alcohol component is in the range of 0.8 to 1.2. It is more preferable to blend so as to be in the range of 9 to 1.1. By setting the content within the above range, unreacted components can be suppressed, and the heat resistance and oil resistance of the resin composition can be improved.

The method for producing the component (B) is not particularly limited, and the component (B) can be produced by a conventionally known method. For example, the polyethylene terephthalate and the alcohol component are heated and stirred in the presence of an esterification catalyst to transesterify. At this time, the reaction is preferably carried out in an inert atmosphere such as nitrogen gas. Then, an acid component and, if necessary, a polymerization inhibitor are added, heated and stirred, and esterified to obtain a polyethylene terephthalate-modified unsaturated polyester resin.

The acid value of the polyethylene terephthalate-modified unsaturated polyester resin of the component (B) thus obtained is preferably 5 to 35, more preferably 10 to 25. When the acid value is 5 or more, the reaction can be easily controlled and gelation can be suppressed, and when the acid value is 35 or less, the residual amount of unreacted material can be suppressed and sufficient curing can be achieved.
The method for measuring the acid value is the same as that for the epoxy ester resin of the component (A).

The blending amount of the component (B) is such that the polyethylene terephthalate component in the total amount of the resin composition is 0.5 to 5.0% by mass, preferably 0.4 to 2.0%. If the polyethylene terephthalate component is less than 0.5%, the heat resistance and oil resistance are inferior, and if it exceeds 5.0%, the adhesiveness is inferior.
Further, the blending amount of the component (B) is such that the polyethylene terephthalate component in the resin composition does not impair the mass ratio of 0.5 to 5.0% with respect to 100 parts by mass of the component (A). , 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, and even more preferably 15 to 25 parts by mass. The heat resistance can be improved by setting the amount to 5 parts by mass or more, and the adhesiveness can be improved by setting the amount to 50 parts by mass or less.

In the present invention, a conventionally known unsaturated polyester resin can be used in combination as long as the effects of the present invention are not impaired. When an unsaturated polyester resin other than the component (B) is blended in the resin composition, the blending amount is preferably 30 parts by mass or less, preferably 20 parts by mass or less, based on 100 parts by mass of the component (B). It is more preferable that the amount is 10 parts by mass or less.

[(C) Reactive diluent]
The reactive diluent of the component (C) used in the present invention is a di (meth) acrylate derivative of a polyalkylene oxide having a number average molecular weight (Mn) of 250 to 2,000, and is crazing resistant to the cured product of the resin composition. It has the effect of improving sex.
When the number average molecular weight (Mn) of the component (C) is 250 or more, the flexibility of the cured product can be increased and the crazing resistance can be improved, and when it is 2,000 or less, the viscosity of the resin composition becomes high. It can be suppressed from passing. From this point of view, the number average molecular weight (Mn) of the component (C) is preferably 250 to 1,000, more preferably 300 to 500.

Examples of the component (C) include polyethylene glycol di (meth) acrylates such as triethylene glycol di (meth) acrylate and tetraethylene glycol di (meth) acrylate; tripropylene glycol di (meth) acrylate and tetrapropylene glycol di (meth) acrylate. Examples thereof include polypropylene glycol di (meth) acrylate such as meta) acrylate. Of these, polyethylene glycol di (meth) acrylate is preferable, and polyethylene glycol dimethacrylate is more preferably used. These can be used alone or in combination of two or more.

The blending amount of the component (C) is preferably 20 to 300 parts by mass, more preferably 30 to 200 parts by mass, and further preferably 30 to 150 parts by mass with respect to 100 parts by mass of the component (A). When the blending amount is 20 parts by mass or more, the viscosity of the resin composition can be suppressed from becoming too high and the workability can be improved, and when the blending amount is 300 parts by mass or less, the decrease in viscosity can be suppressed. .. In addition, it is possible to suppress a decrease in the content of the component (A) contained in the resin composition and improve heat resistance and adhesive strength.

In the present invention, a reactive diluent other than the conventionally known component (C) can be used in combination as long as the effect of the present invention is not impaired. When a reactive diluent other than the above component (C) is blended in the resin composition, the blending amount thereof shall be 20 parts by mass or less with respect to 100 parts by mass of the reactive diluent of the component (C). It is more preferable that the amount is 10 parts by mass or less, but it is more preferable that the mixture is not blended.

The resin composition for coil impregnation of the present invention contains two or more kinds of di (meth) acrylate derivatives of the polyalkylene oxide component (C), or further contains a (c-1) tri (meth) acrylate compound. However, it is preferable from the viewpoint of improving the adhesive force. By using the di (meth) acrylate derivative of the polyalkylene oxide component (C) and the tri (meth) acrylate compound of the component (c-1) in combination as the reactive diluent, the crosslink density of the cured resin product is increased. A cured resin product that is more rigid and has excellent adhesiveness can be obtained.

Examples of the tri (meth) acrylate compound of the component (c-1) include trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaelthritol triacrylate, propoxylated trimethylolpropane triacrylate, and propoxylated glyceryl. Examples thereof include triacrylate and trimethylolpropane trimethacrylate. Of these, trimethylolpropane trimethacrylate is preferably used. These can be used alone or in combination of two or more.

The molecular weight of the component (c-1) is preferably 250 to 2,000. If it is 250 or more, the flexibility of the cured product can be increased and the crazing property can be improved, and if it is 2,000 or less, the increase in viscosity can be suppressed.
The amount of the component (c-1) to be blended is preferably 2 to 20 parts by mass, more preferably 3 to 10 parts by mass, and further preferably 3 to 5 parts by mass with respect to 100 parts by mass of the component (C). is there. Sufficient adhesive strength can be obtained when the amount is 2 parts by mass or more, and crazing property can be improved when the amount is 20 parts by mass or less.

[(D) Organic peroxide]
The organic peroxide of the component (D) is used to cure the epoxy ester resin of the component (A) and the polyethylene terephthalate-modified unsaturated polyester resin of the component (B). Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxide, acetyl peroxide, methyl ethyl ketone peroxide, acyl peroxide, cumene peroxide, peroxyketal and the like. These can be used alone or in combination of two or more.

The blending amount of the component (D) is preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the total blending amount of the component (A), the component (B), and the component (C). More preferably, it is 5 to 2.0 parts by mass. The reaction rate can be increased by setting the content to 0.1 part by mass or more, and the stability of the resin composition can be improved by setting the content to 3.0 parts by mass or less.

In order to accelerate the curing of the resin composition for coil impregnation of the present invention, a curing accelerator may be added to the resin composition. The curing accelerator is not particularly limited, and examples thereof include metal salts of naphthenic acid or octyl acid (for example, metal salts of cobalt, zinc, zirconium, manganese, calcium, etc.). These can be used alone or in combination of two or more.

A polymerization inhibitor can be added to the resin composition for coil impregnation of the present invention. Examples of the polymerization inhibitor include quinones such as hydroquinone, methquinone, pt-butylcatechol, and pyrogallol. These can be used alone or in combination of two or more.

Further, the resin composition for coil impregnation of the present invention is appropriately blended with additives such as an inorganic filler, a colorant, a settling inhibitor, a defoaming agent, and a leveling agent as long as the effects of the present invention are not impaired. can do.

The resin composition for impregnating a coil of the present invention can be obtained by blending the components (A) to (D) and additives to be blended as needed by a conventional method and reacting them. Details will be described in Examples.

The content of the component (A), the component (B), the component (C), and the component (D) in the resin composition for coil impregnation of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more. More preferably, it is 80% by mass or more.

The resin composition for coil impregnation of the present invention has high crazing resistance and hydrolysis resistance, is excellent in heat resistance and oil resistance, and can obtain a cured product having high adhesive strength.
Such a resin composition for impregnating a coil can be used in fields that require heat resistance and weather resistance, such as automobiles, vehicles, or electrical equipment such as industrial and consumer equipment. In particular, the coil impregnating resin composition of the present invention has, for example, an insulating resin composition for windings for a drive motor of an electric vehicle including a hybrid car, which may be exposed to various oils or in a high temperature environment close to 200 ° C. It can be suitably used as a product.

<Coil for automobile motor>
The coil for an automobile motor of the present invention is formed by impregnating the coil portion with the above-mentioned resin composition for impregnating a coil. Such a coil can be manufactured by a conventionally known method. For example, the stator coil can be obtained by impregnating an unimpregnated coil with a coil impregnating resin composition, drying and curing the same as the conventional coil impregnating resin composition. The impregnation method is not particularly limited, and a conventional impregnation method, for example, a drop impregnation method or the like can be applied. Hereinafter, the impregnation method will be described with an example.

In the drip impregnation method, first, the unimpregnated coil is held by an internal jig (chuck) so as to be horizontal. Then, while rotating the unimpregnated coil, the impregnation process is performed by a dropping impregnation method in which the resin composition for coil impregnation is dropped, and the coil impregnation resin is performed between the stator coil windings and between the stator coil windings and the stator core slot wall. Impregnate the composition.

By heat-curing the stator coil impregnated in this manner at a temperature of 100 to 190 ° C. for 10 to 120 minutes, the resin composition for coil impregnation is sufficiently impregnated to obtain a cured stator coil.

Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.

[Synthesis Example 1]
(Synthesis of Mixture (1) of Polyethylene terephthalate Modified Unsaturated Polyester Resin and Reactive Diluent)
13 g of polyethylene terephthalate (PET) (Mn = 40,000), 15 g of diethylene glycol, and 0.01 g of tetra n-butyl titanate were added, and a transesterification reaction was carried out at 210 to 230 ° C. while inflowing nitrogen gas. Then, 14 g of maleic anhydride and 0.02 g of methquinone were added and reacted at 220 ° C. to obtain a PET-modified unsaturated polyester resin having an acid value of 25. To this reaction product, 60 g of polyethylene glycol dimethacrylate [manufactured by Nichiyu Co., Ltd., Blemmer PDE-200, Mn = 362] as a reactive diluent (1) and 0.02 g of manganese octylate as a curing accelerator were added. The mixture was stirred and mixed until it became uniform to obtain a mixture (1) of a polyethylene terephthalate-modified unsaturated polyester resin and a reactive diluent.

[Synthesis Example 2]
(Synthesis of Mixture (2) of Polyethylene terephthalate Modified Unsaturated Polyester Resin and Reactive Diluent)
Polyethylene terephthalate modification in the same manner as in Synthesis Example 1 except that PET having a number average molecular weight (Mn) = 20,000 was used instead of PET having a number average molecular weight (Mn) = 40,000 in Synthesis Example 1. A mixture (2) of an unsaturated polyester resin and a reactive diluent was obtained.

[Synthesis Example 3]
(Synthesis of Mixture (3) of Polyethylene terephthalate Modified Unsaturated Polyester Resin and Reactive Diluent)
Polyethylene terephthalate modification in the same manner as in Synthesis Example 1 except that PET having a number average molecular weight (Mn) = 5,000 was used instead of PET having a number average molecular weight (Mn) = 40,000 in Synthesis Example 1. A mixture (3) of an unsaturated polyester resin and a reactive diluent was obtained.

[Synthesis Example 4]
(Synthesis of Mixture (4) of Polyethylene terephthalate Modified Unsaturated Polyester Resin and Reactive Diluent)
Polyethylene terephthalate in the same manner as in Synthesis Example 1 except that diethylene glycol dimethacrylate [manufactured by Shin Nakamura Chemical Industry Co., Ltd., 2G, Mn = 242] was used instead of the reactive diluent (1) in Synthesis Example 1. A mixture (4) of a modified unsaturated polyester resin and a reactive diluent was obtained.

[Synthesis Example 5]
(Synthesis of Mixture (5) of Polyethylene terephthalate Modified Unsaturated Polyester Resin and Reactive Diluent)
Polyethylene terephthalate-modified unsaturated polyester resin and reaction in the same manner as in Synthesis Example 1 except that 60 g of 2-hydroxyethyl methacrylate (2-HEMA) was used instead of the reactive diluent (1) in Synthesis Example 1. A mixture of sex diluents (5) was obtained.

Next, the preparation of the epoxy ester resin will be described.
[Synthesis Example 6]
(Synthesis of Epoxy Ester Resin (1))
Liquid bisphenol A type epoxy resin (manufactured by Mitsui Chemicals Co., Ltd., trade name: R140P, epoxy equivalent: 188 g / equivalent) 20 g, solid bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name: jER1001, epoxy equivalent: (400-500 g / equivalent) 12 g, methquinone 0.01 g, methacrylic acid 8 g, and triphenylphosphine 0.1 g were added and reacted at 90 ° C. to obtain a reaction product having an acid value of 6. To this reaction product, 5 g of tetrahydrophthalic anhydride was added and reacted at 90 ° C. to obtain an epoxy ester resin (1) having an acid value of 15.

[Synthesis Example 7]
(Synthesis of epoxy ester resin (2))
Synthesis except that in Synthesis Example 6, 20 g of liquid bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name: jER807, epoxy equivalent: 160 to 175 g / equivalent) was used instead of the liquid bisphenol A type epoxy resin. An epoxy ester resin (2) was obtained in the same manner as in Example 6.

[Example 1]
43 g of epoxy ester resin (1) as a component (A), 0.01 g of pt-butyl catechol as a polymerization inhibitor, 50 g of a reactive diluent (1) as a component (C), and tri as a component (c-1). Methylolpropantrimethacrylate [manufactured by Sartmer Japan Co., Ltd., trade name SR350] 2 g, a mixture of polyethylene terephthalate-modified unsaturated polyester resin and a reactive diluent (1) 9 g, and manganese octylate 0.2 g as a curing accelerator. In addition, the mixture was stirred and mixed until uniform to obtain a resin composition. To 100 g of this resin composition, 1.0 g of 1,1-di-t-butylperoxycyclohexane [Trigonox 22-70E, manufactured by Kayaku Akzo Corporation] as a component (D) is added and stirred and mixed until uniform. Then, a resin composition for impregnating the coil was obtained. The polyethylene terephthalate component in this coil impregnating resin composition was about 1.1% by mass.

[Examples 2 to 6 and Comparative Examples 1 to 4]
A resin composition for coil impregnation was obtained in the same manner as in Example 1 except that the components of the types and blending amounts shown in Table 1 were changed in Example 1. In Table 1, blanks indicate no compounding.
Details of each component shown in Table 1 used for preparing the resin composition for coil impregnation are as follows.

<Epoxy ester resin>
[(A) component]
-Epoxy ester resin (1): Epoxy ester resin produced in Synthesis Example 6-Epoxy ester resin (2): Epoxy ester resin produced in Synthesis Example 7.

<Mixture containing polyethylene terephthalate modified unsaturated polyester resin>
[Mixture of component (B) and component (C)]
-Mixture of polyethylene terephthalate-modified unsaturated polyester resin and reactive diluent (1): Mixture of polyethylene terephthalate-modified unsaturated polyester resin and reactive diluent produced in Synthesis Example 1-Polyethylene terephthalate-modified unsaturated polyester resin And a mixture of reactive diluent (2): A mixture of polyethylene terephthalate-modified unsaturated polyester resin produced in Synthesis Example 2 and a reactive diluent.

[Mixture of polyethylene terephthalate-modified unsaturated polyester resin other than component (B) and component (C)]
-Mixture of polyethylene terephthalate-modified unsaturated polyester resin and reactive diluent (3): Mixture of polyethylene terephthalate-modified unsaturated polyester resin and reactive diluent produced in Synthesis Example 3 [Component (B) and other reactions Mixture of sex diluent]
-Mixing of polyethylene terephthalate-modified unsaturated polyester resin and reactive diluent (4): Mixture of polyethylene terephthalate-modified unsaturated polyester resin and reactive diluent produced in Synthesis Example 4-Polyethylene terephthalate-modified unsaturated polyester resin (5): Mixture of polyethylene terephthalate-modified unsaturated polyester resin and reactive diluent produced in Synthesis Example 5 ・ Mixture of polyethylene terephthalate-modified unsaturated polyester resin and reactive diluent

<Reactive diluent>
[Component (C)]
-Reactive diluent (1): polyethylene glycol dimethacrylate, manufactured by NOF CORPORATION, Blemmer PDE-200, Mn = 362
-Reactive diluent (2): Polyethylene glycol dimethacrylate, manufactured by NOF CORPORATION, Blemmer PDE-400, Mn = 550.
[(C-1) component]
-Trimethylolpropane trimethacrylate: manufactured by Sartmer Japan Co., Ltd., trade name SR350, Mn = 338

[Other reactive diluents]
-Diethylene glycol dimethacrylate: manufactured by Shin Nakamura Chemical Industry Co., Ltd., 2G, Mn = 242
-2-Hydroxyethyl methacrylate (2-HEMA): manufactured by Mitsubishi Gas Chemical Company, Inc., trade name 2-hydroxyethyl methacrylate

<Organic peroxide>
[Component (D)]
1,1-di-t-butylperoxycyclohexane: manufactured by Kayaku Akzo Corporation, trade name Trigonox 22-70E

[Other ingredients]
-Polymerization inhibitor: pt-butylcatechol, manufactured by Wako Pure Chemical Industries, Ltd., trade name 4-t-butylpyrocatechol-hardening accelerator: manganese octylate, manufactured by Nippon Chemical Industries, Ltd., trade name Nikka Octix Manganese 8% (T)

The characteristics of the resin composition for coil impregnation prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were measured and evaluated under the measurement conditions shown below. The evaluation results are shown in Table 1.

[Evaluation]
(1) Crazing property A magnet wire elongated by 3%, 5% and 10% was immersed in a resin composition for coil impregnation for 5 minutes, then taken out and cured at 120 ° C. for 1 hour. The obtained cured product was confirmed to have no crazing with a magnifying microscope (manufactured by KEYENCE CORPORATION, trade name VHZ-100). Those without crazing were evaluated as G, and those with crazing were evaluated as F.

(2) Tracker Adhesiveness (2-1) Initial Tracker Adhesiveness The test was carried out according to the JIS C2103 tracker adhesiveness test. As the wire rod, a polyester wire having a diameter of 1.3 mm and a length of 50 mm was used. The polyester wire was impregnated into the resin composition for coil impregnation by the treatment method specified in JIS C2103, and cured under the conditions of a curing temperature of 120 ° C. and a treatment time of 1 hour, and the test piece was used at 25 ° C. The tracker adhesive strength was measured. This was done 5 times and the average value was taken as the initial tracker adhesive strength. In addition, 290 N / 25 ° C. or higher is regarded as acceptable.

(2-2) Tracker Adhesive Strength After Moisture Resistance Test Using a constant temperature and humidity chamber, the test piece obtained in (2-1) was left at a temperature of 85 ° C and a humidity of 85% for 168 hours, and then at 25 ° C. The tracker adhesive strength was measured at. This was performed 5 times, and the average value was taken as the tracker adhesive strength after the moisture resistance test. In addition, 280 N / 25 ° C. or higher is regarded as acceptable.

(2-3) Tracker Adhesive Strength after Oil Immersion Test Using ATF oil supplemented with 0.2 wt% water as a test solution, the test piece obtained in (2-1) was immersed in the test solution. After leaving at 150 ° C. for 1000 hours, the tracker adhesive strength at 25 ° C. was measured. This was performed 5 times, and the average value was taken as the tracker adhesive strength after the oil immersion test. In addition, 270 N / 25 ° C. or higher is regarded as acceptable.

As described above, in Examples 1 to 6 using the resin compositions containing the components (A) to (D), no crazing was observed in the cured product, and the initial tracker adhesive strength was 290 N / 25. The result is that the tracker adhesive strength after the moisture resistance test is 280 N / 25 ° C. or higher and the tracker adhesive strength after the oil immersion test is 270 N / 25 ° C. or higher, and the hydrolysis resistance, heat resistance and oil resistance are excellent. was gotten.

Claims (4)

A resin composition for coil impregnation containing (A) epoxy ester resin, (B) polyethylene terephthalate-modified unsaturated polyester resin, (C) reactive diluent, and (D) organic peroxide.
The number average molecular weight of polyethylene terephthalate used in the (B) polyethylene terephthalate-modified unsaturated polyester resin is 20,000 to 60,000, and the mass ratio of the polyethylene terephthalate component contained in the total amount of the resin composition is A resin for impregnating a coil, which is 0.5 to 5.0%, and the (C) reactive diluent is a di (meth) acrylate derivative of a polyalkylene oxide having a number average molecular weight of 250 to 2,000. Composition. The resin composition for coil impregnation according to claim 1, further containing (c-1) a tri (meth) acrylate compound. The coil impregnation according to claim 2, wherein the content ratio of the (c-1) tri (meth) acrylate compound is 2 to 20 parts by mass with respect to 100 parts by mass of the (C) reactive diluent. Resin composition for. A coil for an automobile motor obtained by impregnating a coil portion with the resin composition for impregnating a coil according to any one of claims 1 to 3.