JPH0745126A - Resin composition for impregnation - Google Patents

Abstract

PURPOSE:To provide a resin composition for impregnation having excellent heat resistance, and in particular to provide the resin composition for impregnation, which has excellent adhesive strength with an enamel wire, which is gelatinized n a short period of time, and which has the insulating function with the heat resistance of no less than approximately 200 deg.C by carrying out post-cure for 2-3 hours after hardening. CONSTITUTION:A resin composition for impregnation is provided, the main agent of which is a blended solution provided by mixing and dissolving a bisphenol epoxy resin, a cresol novolak epoxy resin and an alicyclic epoxy resin. As the hardening accelerator, 1.8-diazo-bisiclo (5, 4, 0) undecene-7, is used by 0.5-3(phr), or 1.8-diazo-bisiclo (5, 4, 0) undecene-7/phenol acid salt is used by 0.5-3 (phr).

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 impregnation, and more particularly to a resin composition for impregnation which is required to have heat resistance and insulation after curing and which is used for electrical insulation and the like.

[0002]

2. Description of the Related Art Hitherto, resin compositions for impregnation have been used in various fields such as electric insulation impregnation, and for example, they have been used for insulation impregnation of a stator of a rotating machine or a rotor. At this time, generally, the stator and the rotor are electrically heated, and the impregnating resin composition is dropped from the coil end portion for impregnation.

In such a resin composition for impregnation,
It is desirable that it has excellent insulation and heat resistance after being cured.

At present, as a resin composition for impregnation, heat resistance F
The species (maximum allowable temperature 155 ° C.) is versatile, and the heat-resistant F species is used as a raw material for commercialization.

[0005]

However, as an impregnating resin, it is hardened in a short time and has heat resistance capable of withstanding a high temperature of 200 ° C. or more, and further has excellent insulating properties and adhesive strength with an enameled wire. Resin does not hit.

Particularly, in the case where the stator of the rotating machine or the rotor is electrically heated as described above to perform the drop impregnation, it takes 3 minutes to 3 minutes.
Gel in about 0 minutes (preferably about 5 to 10 minutes),
And heat resistance of 200 ℃ by post cure for 2-3 hours.
A resin having the above insulation performance is required, but such a resin has not been found at present.

The present invention has been made under the above background, and an object thereof is to provide an impregnating resin composition having excellent heat resistance. In particular, it has excellent adhesive strength with enamel wire, and 3
Resin composition for impregnation having a gelling property in a short time of about 30 minutes to 30 minutes (preferably about 5 minutes to 10 minutes), and having a heat resistance of about 200 ° C. or more by post-curing for 2 to 3 hours after curing. The purpose is to provide things.

[0008]

In order to solve the above problems, the invention according to claim 1 provides a bisphenol epoxy resin 10 to 75 (wt%) and a cresol novolac epoxy resin 10 to 40 (wt%). As a main component, a resin composition consisting of the rest alicyclic epoxy resin as a curing accelerator 1.
8-diazo-bicyclo (5,4,0) undecene-7 0.5 to 3 (phr)
Provided is a resin composition for impregnation, which is characterized by containing.

According to the second aspect of the present invention, a resin composition comprising a bisphenol epoxy resin 10 to 75 (wt%), a cresol novolac epoxy resin 10 to 40 (wt%), and a balance alicyclic epoxy resin as a main component. , As a curing accelerator
Provided is a resin composition for impregnation, which comprises 0.5 to 3 (phr) of 1.8-diazo-bicyclo (5,4,0) undecene-7.phenolate.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the impregnating resin composition described above, the epoxy equivalent of the cresol novolac-based epoxy resin is 200 to 2
30 cresol novolac epoxy resin is used, bisphenol A type epoxy resin having an epoxy equivalent of 190 to 210 is used as the bisphenol epoxy resin, and tetrahydrophthalic hydride is further used as the acid anhydride curing agent. The present invention provides a resin composition for impregnation.

Each of the above-mentioned impregnating resin compositions has an insulating property of heat resistance of 200 ° C. or higher after being cured by post-curing for 2 to 3 hours.

[0012] In particular, the alicyclic epoxy resin tends to have improved temperature characteristics but lower thermal deterioration characteristics when the mixing ratio is increased. Therefore, the mixing ratio should be 10-75 (wt%)
By so doing, it is possible to obtain high temperature characteristics and suppress deterioration of heat deterioration characteristics.

Further, the cresol novolac type epoxy resin has higher heat deterioration characteristics when the mixing ratio is increased, but when added in a large amount, the viscosity of the impregnating resin composition is 2 (p).
As a result, workability may be impaired. Therefore,
By setting the mixing ratio to 10 to 40 (wt%), the viscosity before curing becomes 2 (p) or less, the workability during impregnation is improved, and high heat deterioration characteristics can be obtained.

As a curing accelerator, 1.8-diazo-bicyclo (5,
0.5 to 3 (phr) of 4,0) undecene-7 or 0.5 to 3 (ph) of 1.8-diazo-bicyclo (5,4,0) undecene-7-phenolate
By using r), the gelling time (exothermic peak method) of the resin composition for impregnation can be set to a preferable value of 3 to 30 minutes in terms of workability.

It is also possible to properly adjust the gelling time by changing the addition amount of the curing accelerator.

The impregnating resin composition can be stably stored for 2 months or more without deposits in a state where the curing agent, the curing accelerator and the like are not added.

Further, the additives such as the above-mentioned curing agent and curing accelerator are also mixed in the state where these curing agent and curing accelerator are mixed.
It can be stored stably for more than a month.

[0018]

Example In this example, a cresol novolac epoxy resin, a bisphenol epoxy resin, and an alicyclic epoxy resin were mixed in various ratios to prepare a heat-resistant dropping impregnating resin composition, which was separately prepared. The cured liquid was added and cured, and the heat resistant temperature was measured.

First, 1 cresol novolac epoxy resin (YDCN701, epoxy equivalent 200-230)
After being heated to 20 ° C. and melted, bisphenol A type epoxy resin (Epicoat 828, epoxy equivalent 190
˜210) and an alicyclic epoxy resin (ELR4221) were mixed and stirred until they were homogeneous to produce an epoxy resin composition.

At this time, epoxy resin compositions were prepared by changing the composition ratios of the cresol novolac epoxy resin, the bisphenol A type epoxy resin, and the alicyclic epoxy resin, and samples 1 to 7 were prepared. Table 1 shows the weight ratio of each component in these samples 1 to 7.

[0021]

[Table 1]

In Table 1, cresol novolac epoxy resin is abbreviated as A, bisphenol A type epoxy resin as B, and alicyclic epoxy resin as C. Further, A / B = 1/2 (weight ratio) was set for all these samples.

As the curing liquid, a mixed liquid of a curing agent and a curing accelerator is used.

An acid anhydride, tetrahydrophthalic unhydride (HN-2200), was used as a curing agent, and 1,8-diaza-bicyclo [5,4,
0] A solution containing undecene-7 (DBU) was used as a curing liquid a.

Further, tetrahydrophthalic anhydride (HN-2200) which is an acid anhydride as a curing agent.
1,8-diaza-bicyclo as a curing accelerator
[5,4,0] Undecene-7 / phenolate (SA No.1)
Was added to obtain a hardening liquid b.

Next, the epoxy resin composition and the curing liquids a and b were mixed so as to be uniform. The curing conditions at this time were 150 (° C.), 1 (hr) +180, and 2 (hr).

In the curing liquid a, the correlation between the gelling time and the temperature characteristic measured when the amount of the curing accelerator added to the epoxy resin composition is 0.5 to 3.0 (phr) is shown in FIG.
Shown in.

Similarly, the amount of the curing accelerator added to the epoxy resin composition in the curing liquid b is 0.5 to 3.0 (phr).
FIG. 2 shows the correlation of the temperature characteristics with the gelation time at the time.

Incidentally, in FIG. 1, the characteristics when the addition amount of the curing accelerator is 0.5 (phr), 1.0 (phr) and 3.0 (phr) are shown by the lines L1, L2 and L3. Indicated.

Similarly, in FIG. 2, the characteristics when the addition amount of the curing accelerator is 0.5 (phr), 1.0 (phr) and 3.0 (phr) are shown in the lines L4, L5 and L6. Showed.

As shown in FIGS. 1 and 2, the gelation time can be adjusted by adjusting the addition amount of the curing accelerator.

Usually, this curing time is preferably about 4 to 30 minutes, so the addition amount of these is 0.5 to 3.0 as described above.
(Phr) is preferable.

When the amount of the curing agent added was examined, it was found that it was preferable to set it to 0.8 to 1.2 (mol) with respect to the epoxy resin. As the curing agent (acid anhydride cured product), methyl nadic hydride, hexahydrophthalic hydride, or the like may be used in addition to the tetrahydrophthalic hydride used in this example.

Next, the temperature characteristics with respect to the compounding amount of the alicyclic epoxy resin were examined.

First, as an epoxy resin composition, sample 1,
Curing liquid a was added to this epoxy resin composition using Nos. 3 and 5 to cure, and the volume resistivity at 200 ° C. after curing was measured. The result is shown in FIG.

Similarly, Samples 1, 3, and 5 were used as the epoxy resin composition, and a curing solution b was added to the epoxy resin composition.
Was added for curing, and the volume resistivity at 200 ° C. after curing was measured. The result is shown in FIG.

As shown in these figures, it is understood that the temperature characteristics are improved as the amount of the alicyclic epoxy resin compounded is increased.

Further, the heat deterioration characteristics with respect to the compounding amount of the alicyclic epoxy resin were examined. First, Samples 1, 2, 4, 6, and 7 were used as epoxy resin compositions, cured with the curing liquid a, and the TGI (° C.) after curing was examined. The result is shown in FIG.

Similarly, samples 1, 2, 4, 6, and 7 were used as epoxy resin compositions and cured with the curing liquid b, and the TGI (° C.) after curing was examined. The result is shown in FIG.

The TGI value is preferably 280 ° C. or higher.

As shown in these figures, when the compounding amount of the alicyclic epoxy resin is increased, the TGI value is lowered and the thermal deterioration property is deteriorated.

[0042]

According to the present invention, a resin composition for impregnation having excellent heat resistance can be obtained. Further, it has excellent adhesive strength with the enamel wire, and gels in a short time of about 3 minutes to 30 minutes (preferably about 5 minutes to 10 minutes), and has a heat resistance of about 2 to 3 hours after curing by post cure. A resin composition for impregnation having an insulation performance of 200 ° C. or higher is also obtained.

Further, since the temperature characteristics and the heat deterioration resistance can be adjusted, it is possible to obtain the impregnating resin composition suitable for the usage situation.

Furthermore, since the characteristics of the resin composition for impregnation can be appropriately adjusted such that the viscosity at the time of impregnation is reduced to improve the workability, the characteristics of the resin composition for impregnation can be obtained. It is also possible to produce a resin composition for impregnation.

[Brief description of drawings]

FIG. 1 is a graph showing the correlation between gelation temperature and gelation time.

FIG. 2 is a graph showing the correlation between gelation temperature and gelation time.

FIG. 3 is a graph showing the correlation between the mixing amount of (cresol novolac epoxy resin + bisphenol A type epoxy resin) and the volume resistivity.

FIG. 4 is a graph showing the correlation between the mixing amount of (cresol novolac epoxy resin + bisphenol A type epoxy resin) and the volume resistivity.

FIG. 5 is a graph showing the correlation between the mixing amount of (cresol novolac epoxy resin + bisphenol A type epoxy resin) and the TGI value.

FIG. 6 is a graph showing the correlation between the mixing amount of (cresol novolac epoxy resin + bisphenol A type epoxy resin) and the TGI value.

Claims (3)

[Claims] 1. A bisphenol epoxy resin 10 to 7
5 (wt%), cresol novolac epoxy resin 10
40 (wt%), the main component is a resin composition consisting of the rest alicyclic epoxy resin, and 1.8-diazo-bicyclo as a curing accelerator.
A resin composition for impregnation, comprising 0.5 to 3 (phr) of (5,4,0) undecene-7. 2. A bisphenol epoxy resin 10 to 7
5 (wt%), cresol novolac epoxy resin 10
40 (wt%), the main component is a resin composition consisting of the rest alicyclic epoxy resin, and 1.8-diazo-bicyclo as a curing accelerator.
A resin composition for impregnation, comprising 0.5 to 3 (phr) of (5,4,0) undecene-7.phenolate. 3. The impregnating resin composition according to claim 1, wherein a cresol novolac epoxy resin having an epoxy equivalent of 200 to 230 is used as the cresol novolac epoxy resin, and an epoxy equivalent is used as the bisphenol epoxy resin. A resin composition for impregnation, which comprises using a bisphenol A type epoxy resin of 190 to 210 and further tetrahydrophthalic anhydride as the acid anhydride curing agent.