JPH1180324A - Impregnable thermosetting resin composition and electric rotating machine insulated coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition having a long-term storage life stability, short-time setting property, and high impregnation property, and useful for forming an insulating layer excellent in electric and mechanical properties after setting, by including a main ingredient of bisphenol type epoxy resin and polymerization initiator of 2-butenyl tetramethylenesulfonium hexafluoroantimonate. SOLUTION: This objective composition is obtained by blending (B) a latent polymerization initiator of 2-butenyl tetramethylenesulfonium hexafluoroantimonate with (A) a main ingredient of bisphenol type epoxy resin (e.g. bisphenol F-type epoxy resin) in the ratio A/B of 0.1 to 5 wt.%. The composition is raised in impregnation into coating layer and lengthened in lifetime by blending a bifunctional aliphatic epoxy resin (e.g. hexyl diglycidyl ether) as a diluent therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a rotating electric machine for a vehicle,
The present invention relates to an impregnated thermosetting resin composition used for an insulating coil of a stationary industrial induction machine such as a general industrial rotary electric machine or a transformer, and a rotary electric machine insulating coil using the same.

[0002]

2. Description of the Related Art There is a remarkable demand for reduction in size and weight of rotating electric machines for vehicles and general industrial use, and the rotating electric machine insulating coils used for these are required to have excellent high-temperature insulation properties.

[0003] Such an insulating coil includes an insulating layer manufactured by the following method. First, a mica sheet in which laminated mica is adhered to a substrate or an insulating substrate composed of a laminated mica tape in which these sheets are taped and a binder is wound around a coil conductor to form a coating layer having a predetermined thickness. . As the substrate, for example, a woven or nonwoven fabric made of inorganic fibers such as glass fibers, a woven or nonwoven fabric made of organic fibers such as polyamide fibers, or an organic polymer film is used. Subsequently, the low viscosity unsaturated polyester, epoxy resin,
An insulating layer is formed by impregnating and curing an impregnated thermosetting resin such as a silicone resin in an atmosphere of vacuum or pressure or both.

[0004] As the impregnated thermosetting resin, epoxy resins excellent in various properties are generally used. In particular, a combination of an epoxy and an acid anhydride-based curing agent has been used as a main constituent material of the impregnated resin because it has excellent electrical properties and the viscosity is reduced by the curing agent.
Although this resin system has a characteristic that the pot life is long, a curing accelerator requires a relatively high temperature and time, so that a curing accelerator is often used.

However, when the curing accelerator is directly added to the resin, there is a problem that the viscosity of the varnish rises in a short time, and the pot life is shortened. In particular, the varnish impregnation of the insulating layer of the electric insulating coil is performed by putting the insulating coil into an impregnation tank filled with resin, then impregnating the insulating layer, and then adding a new insulating coil and repeatedly using the resin. Things are desired. Therefore, latent curing accelerators that do not affect the pot life of the resin are being studied as curing accelerators for the impregnated resin.

For example, an imidazole compound, a quaternary phosphonium salt, a trifluorinated boron amine compound, an addition reaction product of a tertiary amine and epoxy, a tetraphenylboron complex, a metal acetyl acetate, and the like are known.
In addition, a method in which the curing accelerator is microencapsulated, dispersed in a resin, and heated at a root temperature or higher to dissolve the capsule, dissolve the curing accelerator in the varnish, and subsequently perform a curing reaction, A method has been proposed in which the curing accelerator itself is activated by dissolving at a predetermined temperature or higher.

Incidentally, since the impregnated varnish is impregnated into the dense insulating layer, the curing accelerator must be dissolved in the resin at the impregnation temperature. However, since the microencapsulated hardening accelerator and the dissolution-active hardening accelerator have a certain particle size, when the insulating layer is thickened, the hardening accelerator is used in a process in which the resin permeates the insulating layer. May not sufficiently penetrate into the insulating layer. In this case, since the curing accelerator is insufficient inside the insulating layer, the cured product may not exhibit the predetermined performance even after the heat curing, or the uncured component may volatilize to cause foaming on the surface.

In the method of directly adding the curing accelerator to the impregnated resin as described above, a method of adding the curing accelerator to the insulating layer in advance is known because the usable time of the resin is shortened. . That is, the curing accelerator is added to the binder of the insulating tape, or after the insulating tape is wound around the coil conductor, the solution of the curing accelerator is impregnated and dried, then impregnated with the impregnating resin, and heat-cured. Is the way.

However, when a hardening accelerator is added to the insulating layer, for example, a gap portion containing no hardening accelerator, such as between insulating tapes, hardens later than an insulating substrate portion containing a hardening accelerator. As a result, not only is it difficult to form a uniform insulating layer, but also it becomes difficult to cure the resin adhered to the outer surface of the coil.

After the resin is impregnated into the insulating base layer of the coil, the resin is taken out of the impregnating container and heated in a constant temperature bath to infiltrate the insulating base layer and cure the resin adhering to the surface. In the process, there is a problem that the impregnated resin flows out before it is cured.

The reason why the resin flows out during the heating and curing process is that the viscosity of the thermosetting resin such as an epoxy resin used as the impregnating resin temporarily decreases due to a rise in temperature during the heating and curing. This is a problem that cannot be avoided because of having

The outflow of the resin not only makes it difficult to form a dense insulating layer, but also causes voids inside the insulating layer, which significantly deteriorates electrical characteristics such as corona characteristics and heat dissipation of the coil. .

In order to improve the productivity of electric equipment, in addition to having impregnating properties and short-time curing properties, an impregnated resin capable of forming a good insulating layer even when various backing insulating tapes are used. Is desired.

[0014]

In order to solve the above-mentioned problem, there has been proposed a method of manufacturing an electric insulating coil in which a latent curing accelerator composed of a powder is added to both the insulating layer and the impregnated resin. However, even in this method, the dispersion stability of the curing accelerator in the resin is inferior and precipitation occurs during long-term storage.

In addition, the method of adding the curing accelerator in advance to the binder of the insulating layer is problematic in that a solution in which the binder resin and the curing accelerator are dissolved to form an insulating tape is gelled by several uses. was there.

Further, if the produced tape is stored for a long period of time, the reaction of the binder gradually progresses, and accordingly, the tape becomes harder, which causes a problem that the workability of winding on the insulating coil deteriorates. When an insulated coil is manufactured using a tape having such poor winding work, not only the appearance of the product is reduced, but also the electrical and mechanical properties of the insulating layer are reduced, so that the reliability of the electrically insulated coil is reduced. I do.

Therefore, there is a restriction that the above-mentioned insulating tape is stored in a low-temperature atmosphere or that it needs to be used promptly. The present invention relates to an impregnated thermosetting resin composition capable of forming an insulating layer having long-term storage life stability, short-time curing property, high impregnation property, and extremely good electric and mechanical properties after curing. Another object of the present invention is to provide a rotating electrical machine insulating coil having excellent electrical and mechanical characteristics using the composition.

[0018]

According to the present invention, there is provided an impregnated thermosetting resin composition according to the present invention, which comprises (a) a bisphenol-type epoxy resin as a main component, and (b) a polymerization initiator. And 2-butenyltetramethylenesulfonium hexafluoroantimonate as an agent.

The component (b) is preferably added in an amount of 0.1 to 5% by weight based on the component (a). The impregnated thermosetting resin composition according to claim 1 of the present invention is allowed to contain a bifunctional aliphatic epoxy resin represented by the following general formula (I) as a diluent.

[0020]

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The bifunctional aliphatic epoxy resin includes:
For example, hexyl diglycidyl ether, ethyl diglycidyl ether and the like can be mentioned. The impregnated thermosetting resin composition according to claim 3 according to the present invention comprises: (a) a bisphenol-type epoxy resin as a main agent; and (b) 2-butenyltetramethylenesulfonium hexafluoroantimonate as a polymerization initiator. (C) It is characterized by containing 0.1 to 30 parts by weight of methyltetrahydrophthalic acid as a curing accelerator added to 100 parts by weight of the components (a) and (b).

The component (b) is preferably added in an amount of 0.1 to 5% by weight based on the component (a). The reason why the amount of the hardening accelerator added is specified is as follows. When the addition amount of the curing accelerator is less than 0.1 part by weight, the working life of the impregnated thermosetting resin composition containing the accelerator and the insulating coil obtained by impregnating and curing the resin composition are obtained. It is difficult to extend the life of the device sufficiently. On the other hand, if the amount of the curing accelerator exceeds 30 parts by weight, the glass transition temperature may be lower than that of the composition without the curing accelerator. A more preferable addition amount of the curing accelerator is the component 10 of (a) and (b).
0.1 to 10 parts by weight with respect to 0 parts by weight.

The impregnated thermosetting resin composition according to claim 3 of the present invention is allowed to contain a difunctional aliphatic epoxy resin represented by the following general formula (I) as a diluent.

[0024]

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According to a fifth aspect of the present invention, there is provided the rotating electrical machine insulation coil according to the first or third aspect, wherein a backing mica tape is wound around a single or a plurality of insulated coated conductors.
The impregnated thermosetting resin composition described above is impregnated and cured by heating.

The impregnated thermosetting resin composition is impregnated with a mica sheet in which laminated mica is adhered to a substrate, or an insulating substrate composed of a laminated mica tape in which these sheets are taped and a binder, and a coil conductor. Is a coating layer having a predetermined thickness formed by being wound around the substrate. As the substrate, for example, a woven or nonwoven fabric made of inorganic fibers such as glass fibers, a woven or nonwoven fabric made of organic fibers such as polyamide fibers, or an organic polymer film is used.

The impregnated thermosetting resin composition according to claim 1 according to the present invention described above is soluble in the epoxy resin as the component (a), and is used as the latent polymerization initiator as the latent polymerization initiator as the component (b). -Use of butenyltetramethylenesulfonium hexafluoroantimonate has long-term storage life stability, short-time curability, and high impregnation. For this reason,
When the resin composition is impregnated into the coating layer, the resin composition is uniformly cured in the coating layer, and the curing proceeds in a short time. As a result, it becomes possible to form an insulating layer having extremely good electrical characteristics, mechanical characteristics, and the like after curing.

In the resin composition, the viscosity of the resin composition can be reduced by using the aliphatic epoxy resin represented by the general formula (I) as a diluent, so that the impregnating property of the coating layer is reduced. It can be enhanced to enhance uniform curing in the coating layer. Further, since the diluent has lower reactivity than the bisphenol-type epoxy resin as the component (a), the working life of the resin composition can be extended.

The impregnated thermosetting resin composition according to claim 3 of the present invention has long-term storage life stability, short-time curability, and high impregnation as described above, but has the potential to be a component (b). Since 2-butenyltetramethylenesulfonium hexafluoroantimonate as a polymerization initiator has a high reaction rate, it lowers the crosslink density of the epoxy resin as the component (a). By adding 0.1 to 30 parts by weight of methyltetrahydrophthalic acid as a curing accelerator to 100 parts by weight of the total amount of the components (a) and (b), the reaction rate is reduced in productivity. It is possible to improve the crosslinking density of the epoxy resin as the component (a) while suppressing the degree to which the crosslinking does not occur. As a result, the cured product obtained by curing the resin composition and the high-temperature characteristics of the impregnated and cured insulating coil can be improved, and the pot life can be extended.

By using the aliphatic epoxy resin represented by the general formula (I) as a diluent in the resin composition, the impregnating property of the coating layer can be improved, and the pot life of the resin composition can be reduced. It can be longer.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, more preferred embodiments of the present invention will be described in detail. [Example 1] Hexyl diglycidyl ether as a diluent (trade name, manufactured by Yuka Shell Epoxy; YED-) per 100 parts by weight of bisphenol F type epoxy resin (trade name, manufactured by Yuka Shell Epoxy; YL-6042) 216)
20 parts by weight and 1 part by weight of a polymerization initiator 2-butenyltetramethylenesulfonium hexafluoroantimonate (trade name; CP-66, manufactured by Asahi Denka Co., Ltd.) are sequentially mixed and sufficiently stirred at room temperature to obtain an impregnated resin. A composition was prepared.

Next, a silicone string having a diameter of 2 mm is arranged in a U-shape between two glass plates (dimensions: 200 mm × 150 mm × 2.0 mm) each having an adhesive tape for release made of polytetrafluoroethylene adhered to the surface. Then, a mold was prepared. Subsequently, by injecting the impregnated resin composition into the mold, raising the temperature from room temperature to 150 ° C. in 5 hours, maintaining the temperature for 5 hours, and performing heat curing to reduce the temperature to room temperature over 5 hours, 100mm x 150mm x 2mm
Was prepared.

[Examples 2-1 to 2-6] Bisphenol F type epoxy resin (trade name, manufactured by Yuka Shell Epoxy Co .; Y)
L-6042) 100 parts by weight, 20 parts by weight of hexyl diglycidyl ether (trade name, manufactured by Yuka Shell Epoxy Co., Ltd .; YED-216) as a diluent, and 2-butenyltetramethylenesulfonium hexafluoro as a polymerization initiator Antimonate (product name; CP-6, manufactured by Asahi Denka Co., Ltd.)
6) 1 part by weight was sequentially mixed and sufficiently stirred at room temperature. Subsequently, 0.1 part by weight, 0.5 part by weight of methyltetrahydrophthalic acid (trade name, manufactured by Zeon Corporation; QH-200) as a curing accelerator was added to 100 parts by weight of this mixture.
1.0 part by weight, 5.0 parts by weight, 10 parts by weight, and 30 parts by weight were added, and the mixture was sufficiently stirred at room temperature to prepare six kinds of impregnated resin compositions.

Each of the impregnated resin compositions thus obtained was poured into a mold in the same manner as in Example 1, and was cured by heating to produce six types of resin plates. [Reference Example 1] The amount of methyltetrahydrophthalic acid added was 8
Except for 0 part by weight, the same impregnated resin composition as in Examples 2-1 to 2-6 was prepared.

Each of the obtained impregnated resin compositions was poured into a mold in the same manner as in Example 1 and was cured by heating to produce a resin plate. [Comparative Example 1] An epoxy resin composition for impregnation (trade name: TVB2632 manufactured by Toshiba Chemical Co., Ltd.) was poured into each mold in the same manner as in Example 1, and the temperature was raised from room temperature to 150 ° C for 5 hours, and the temperature was raised. The resin plate was prepared by holding for 15 hours, lowering to room temperature over 5 hours, and curing by heating.

The life of the obtained resin compositions of Examples 1, 2-1 to 2-6, Reference Example 1 and Comparative Example 1, and the glass transition temperature of the resin plates produced from those resin compositions, based on the coefficient of linear expansion, It was measured. The results are shown in Table 1 below. The service life of each resin composition was exposed to an atmosphere of 40 ° C. for 25 minutes.
Determined from the change in the viscosity of each resin composition at ℃,
The time point when the viscosity became twice the initial viscosity was determined as the life.

[0037]

[Table 1]

As is clear from Table 1, Example 1
It can be seen that the time when the initial viscosity doubles is longer than that in Comparative Example 1. The glass transition temperature of Comparative Example 1 was 70 ° C., while that of Example 1 was 80 ° C.
It turns out that it improves.

Further, as is clear from Examples 2-1 to 2-6, it is understood that the life is prolonged as the addition amount of methyltetrahydrophthalic acid as a curing accelerator increases. Regarding the glass transition temperature, Comparative Example 1 was prepared when the amount of methyltetrahydrophthalic acid was in the range of 0.1 to 30 parts by weight.
It can be seen that it is improved as compared with. In particular, it can be seen that when the addition amount of methyltetrahydrophthalic acid is in the range of 0.1 to 10 parts by weight, the amount of methyltetrahydrophthalic acid is improved as compared with Example 1 in which no addition is made.

In Reference Example 1 where the amount of methyltetrahydrophthalic acid added exceeds 30 parts by weight, the life is prolonged, but the glass transition temperature is lower than that of Comparative Example. [Example 3] Hexyl diglycidyl ether (trade name, manufactured by Yuka Shell Epoxy; YED-) as a diluent was added to 100 parts by weight of bisphenol F type epoxy resin (trade name, manufactured by Yuka Shell Epoxy; YL-6042). 216)
20 parts by weight and 3 parts by weight of 2-butenyltetramethylenesulfonium hexafluoroantimonate (trade name; CP-66, manufactured by Asahi Denka Co., Ltd.) as a polymerization initiator were sequentially mixed and sufficiently stirred at room temperature. Subsequently, the mixture 10
0.5 parts by weight of methyltetrahydrophthalic acid (trade name; manufactured by Zeon Corporation; QH-200) as a curing accelerator is added to 0 parts by weight, and the impregnated resin composition is obtained by sufficiently stirring at room temperature. Prepared.

On the other hand, a 25 mm wide glass cloth lined mica tape is wound around an aluminum conductor having a size of 10 mm × 20 mm × 200 mm four times with a 重 double winding, and a 25 mm wide shrinkable polyethylene terephthalate tape (manufactured by Toray Industries, Inc.) (Lumirror) was wound once with a double winding to produce an insulating bar model. The laminated mica tape was obtained by applying an epoxy binder having a composition shown in Table 2 below to a hard-fired laminated mica.

[0042]

[Table 2]

Next, the impregnated resin composition was impregnated with the insulating bar model at 40 ° C. under a vacuum of 0.5 mmHg for 2 hours, and subjected to a pressure treatment at 5 kgf / cm ² for 15 hours. Thereafter, the temperature was raised from room temperature to 150 ° C. in a hot-air circulation type thermostat in 5 hours, held for 5 hours, and heat-cured to lower the temperature to room temperature in 5 hours to produce a rotating electric machine insulation coil.

Comparative Example 2 An epoxy resin composition for impregnation (trade name: TVB2632, manufactured by Toshiba Chemical Co., Ltd.) was impregnated into an insulating bar model under the same conditions as in Example 3, and was heated from room temperature to 150 ° C. in a hot-air circulating thermostat. The temperature was raised for 5 hours, and the temperature was maintained for 15 hours, and then heat-cured to lower the temperature to room temperature over 5 hours to produce a rotating electrical machine insulating coil.

With respect to the obtained rotating electric machine insulating coils of Example 3 and Comparative Example 2, the glass transition temperature was measured. As a result, it was confirmed that the rotating electrical machine insulating coil of Comparative Example 2 had an excellent characteristic of 85 ° C., while the rotating electrical machine insulating coil of Example 3 had an excellent temperature of 85 ° C.

The tan δ (%) with respect to the temperature was measured for the rotating electric machine insulating coils of Example 3 and Comparative Example 2. The result is shown in FIG. As is apparent from FIG. 1, it is understood that the rotating electrical machine insulating coil of Example 3 has better electrical characteristics than the rotating electrical machine insulating coil of Comparative Example 2.

[0047]

According to the present invention, as described in detail above, the following various effects can be obtained. (1) Bisphenol type epoxy resin as main agent,
By using 2-butenyltetramethylenesulfonium hexafluoroantimonate as a polymerization initiator, it is possible to shorten the curing time and improve workability,
An impregnated thermosetting resin composition having a high glass transition temperature can be obtained.

(2) A bisphenol-type epoxy resin as a main agent, 2-butenyltetramethylenesulfonium hexafluoroantimonate as a polymerization initiator, and a bifunctional aliphatic epoxy resin represented by the general formula (I) as a diluent. By using, in addition to the effect of the above (1), it is possible to obtain an impregnated thermosetting resin composition having a long working life and improved impregnation due to a reduction in viscosity.

(3) A bisphenol-type epoxy resin as a main agent, 2-butenyltetramethylenesulfonium hexafluoroantimonate as a polymerization initiator, and a curing accelerator methyltetrahydrophthalic acid as a curing accelerator, based on 100 parts by weight of these components. By adding 0.1 to 30 parts by weight of the above, it is possible to obtain an impregnated thermosetting resin composition having a higher glass transition temperature than the conventional impregnated thermosetting resin composition and capable of extending the life. . Further, the addition amount of the methyl tetrahydrophthalic acid is 0.1
By setting the content to 10 parts by weight, it is possible to obtain an impregnated thermosetting resin composition having a higher glass transition temperature than that of the impregnated thermosetting resin composition not containing the curing accelerator.

(4) A bisphenol type epoxy resin as a main agent, 2-butenyltetramethylene sulfonium hexafluoroantimonate as a polymerization initiator, and a bifunctional aliphatic epoxy resin represented by the general formula (I) as a diluent. Component 1 of these main ingredients and polymerization initiator used
By adding 0.1 to 30 parts by weight of methyltetrahydrophthalic acid as a curing accelerator to 00 parts by weight, in addition to the effect of the above (3), improvement in impregnation due to lowering viscosity and a longer working life can be achieved. An impregnated thermosetting resin composition can be obtained.

(5) A backing mica tape is wound around a single or a plurality of insulated coated conductors,
By impregnating and heating and curing the impregnated thermosetting resin composition of (4), it is possible to obtain a rotating electrical machine insulation coil having excellent high-temperature characteristics.

[Brief description of the drawings]

FIG. 1 is a characteristic diagram illustrating a relationship between temperature and tan δ (%) in rotating electrical machine insulation coils of Example 3 and Comparative Example 2.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hisayuki Hirai 2-4 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Keihin Works Co., Ltd.

Claims (5)

[Claims] 1. An impregnated thermosetting resin comprising (a) a bisphenol-type epoxy resin as a main ingredient and (b) 2-butenyltetramethylenesulfonium hexafluoroantimonate as a polymerization initiator. Composition. 2. An impregnated thermosetting resin composition according to claim 1, which contains a difunctional aliphatic epoxy resin represented by the following general formula (I) as a diluent. Embedded image 3. (a) a bisphenol-type epoxy resin as a main agent, (b) 2-butenyltetramethylenesulfonium hexafluoroantimonate as a polymerization initiator, and (c) the above (a) and (b) An impregnated thermosetting resin composition comprising methyltetrahydrophthalic acid as a curing accelerator added in an amount of 0.1 to 30 parts by weight per 100 parts by weight of a component. 4. The impregnated thermosetting resin composition according to claim 1, which contains a difunctional aliphatic epoxy resin represented by the following general formula (I) as a diluent. Embedded image 5. A rotation obtained by winding a backing mica tape around a single or a plurality of insulated coated conductors, impregnating with the impregnated thermosetting resin composition according to claim 1, and heating and curing. Electrical insulation coil.