JPH0362724B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermosetting resin composition. More specifically, the present invention relates to a thermosetting resin composition in which a (meth)acrylic or allyl monomer is blended into a polybutadiene-modified epoxy compound, and a phenoxy resin and a liquid cyclic acid anhydride are further blended as an epoxy curing agent.

[Prior Art] Epoxy resins are generally used for impregnating electrical equipment, and many patent applications have been filed so far.

[Problems to be Solved by the Invention] Conventional epoxy impregnated resins often have a high viscosity at room temperature and have a short pot life. A diluent is generally added to the epoxy-impregnated resin to lower its viscosity, but ordinary diluents are highly irritating to the skin, cause a decrease in electrical and mechanical properties, and the cured product also deteriorates. Moreover, many of them do not have sufficient characteristics. The present invention has been made in order to provide a thermosetting resin that has a lower viscosity and longer pot life than conventional epoxy resins, and also has excellent properties of the cured product.

[Means for solving the problem] The present invention is based on the general formula (): 100 weight polybutadiene-modified epoxy compounds obtained by reacting a terminal dicarboxylic acid polybutadiene represented by the formula (in the formula, n represents an integer of 5 to 60) and an epoxy compound having at least two epoxy groups in one molecule. 5 to 200 parts by weight of a polyfunctional vinyl monomer having at least two (meth)acrylic or allyl groups in one molecule,
The present invention relates to a thermosetting resin composition containing 0.1 to 10 parts by weight of a phenoxy resin and 30 to 150 parts by weight of a cyclic liquid acid anhydride.

[Example] The polybutadiene-terminated dicarboxylic acid compound used in the present invention has the general formula (): (In the formula, n is an integer from 5 to 60.) If n is less than 5, the flexibility effect of the polybutadiene chain cannot be obtained, and if it exceeds 60, the viscosity is too high. It is preferable to use 5 to 60.

Further, as the epoxy compound having at least two epoxy groups in one molecule, commonly used ones can be used, and specific examples thereof include glycidyl ether type Epicote 828 (manufactured by Ciel Corporation), DER-332 (manufactured by Dow Corporation), GY-255 (manufactured by Ciba Corporation), novolac type DEN-431 (manufactured by Dow Corporation), and alicyclic type CY-179 (manufactured by Ciba Corporation).

The polybutadiene-modified epoxy compound can be obtained by reacting the terminal dicarboxylic acid polybutadiene with an epoxy compound. In this case, the terminal dicarboxylic acid polybutadiene 100
parts (parts by weight, same hereinafter) of epoxy compound
It is preferable to add 100 parts to 5000 parts; if it is less than 100 parts, properties such as dimensional stability, which is a characteristic of epoxy resin, will be lost, and if it exceeds 5000 parts, the number of polybutadiene units will decrease. It is not preferred because it does not have any effect.

In addition, the reaction conditions are usually 80~
It is preferable to raise the temperature to 200°C, add terminal dicarboxylic acid polybutadiene, and react without a catalyst or in the presence of a catalyst.

The above catalyst may be, for example, a quaternary ammonium salt, a
It is preferable to add a class amine or the like in an amount not exceeding 0.5 parts per 100 parts of the total amount of reactants.

In the present invention, at least two (meta) in one molecule
The reason why a polyfunctional vinyl monomer having an acrylic group or an allyl group is used is because a compound having one (meth)acrylic group or an allyl group in one molecule has low heat resistance, so it is not preferable. Specific examples of polyfunctional vinyl monomers having at least two (meth)acrylic or allyl groups include diallyl phthalate, diallyl isophthalate, triallyl trimellitate, triallyl isocyanurate, bisphenol A diglycidyl ether di(meth) Examples include acrylate, trimethylolpropane tri(meth)acrylate, and trihydroxyethyl isocyanurate tri(meth)acrylate.

The polyfunctional vinyl monomer is used in an amount of 5 parts per 100 parts of the polybutadiene-modified epoxy compound.
It is preferable to mix it in a range of 200 parts to 200 parts. If it is less than 5 parts, it will increase the crosslinking density of the vinyl compound.
If the amount exceeds 200 parts, curing shrinkage becomes too large and the properties of the resin deteriorate, which is not preferable.

In addition, the phenoxy resin used in the present invention has a molecular weight in the range of 15,000 to 60,000 from the viewpoint of its effectiveness, and a polybutadiene-modified epoxy compound with a molecular weight of 100 to 60,000.
It is preferable to mix 0.1 to 10 parts per part, and 0.1
If the amount is less than 1 part, the effect of imparting flexibility and improving adhesiveness will not be sufficient, and if it exceeds 10 parts, the viscosity of the resin will increase too much, which is not preferred.

In addition, examples of the cyclic acid anhydride include methyltetrahydrophthalic anhydride [Hitachi Chemical Co., Ltd.
HN-2200 manufactured by Hitachi Chemical Co., Ltd.], methylhexahydrophthalic anhydride [HN-5500 manufactured by Hitachi Chemical Co., Ltd.], methylendomethylenetetrahydrophthalic anhydride [methyl hymic anhydride manufactured by Hitachi Chemical Co., Ltd.], etc. I can give it to you.

The cyclic acid anhydride is preferably blended in an amount of 30 to 120 parts per 100 parts of the obtained polybutadiene-modified epoxy compound. If it is less than 30 parts, sufficient crosslinking will not be achieved, and if it exceeds 120 parts, the crosslinking density will become too high, which is not preferable.

Furthermore, it is effective to add a catalyst to promote the reaction of the composition obtained above, and examples of catalysts that promote the reaction of the epoxy compound with the acid anhydride include cobalt acetylacetonate, chromium acetylacetonate, Organic metal salts such as zinc octylate and tin octylate, imidazoles, BF ₃ ,
Examples include Lewis acids such as BCl ₃ or their amine salts.

Further, for the purpose of further promoting vinyl polymerization, a vinyl polymerization initiation catalyst such as dicumyl peroxide, benzoyl peroxide, pt-butyl hydroperoxide, azobisisobutyronitrile, etc. can also be used.

In addition, in order to lower the viscosity of this composition, if more than 200 parts of a vinyl monomer having one vinyl group in one molecule is added to 100 parts of a thermosetting resin, the viscosity can be lowered. It is preferable to add in an amount not exceeding 200 parts, since various properties such as physical properties deteriorate, which is undesirable. Examples of the vinyl monomer include styrene, vinyltoluene, α-methylstyrene, acrylonitrile, N
-Vinylpyrrolidone and the like are used.

As mentioned above, the thermosetting resin composition of the present invention has
By using a polybutadiene-modified epoxy compound having polybutadiene as a backbone as the epoxy component, we aim to improve the moisture resistance and heat resistance of the cured product. By blending a polyfunctional vinyl monomer with the above-mentioned polyfunctional vinyl monomer and copolymerizing it with the vinyl group of the polybutadiene of the above-mentioned epoxy compound, the heat distortion temperature is increased and the heat resistance is further improved.

Further, a phenoxy resin is added as a non-crosslinkable linear component and interposed in the crosslinked network, thereby imparting flexibility to the resin and improving adhesive strength at the same time.

Example 1 Terminal dicarboxylic acid polybutadiene (average molecular weight
1000), 760 g of Epicote 828 (manufactured by Ciel) was added to 135 g, and the mixture was reacted at 150°C for 2 hours.
A polybutadiene-modified epoxy compound was obtained. For 100 parts of this polybutadiene-modified epoxy compound,
150 parts of trihydroxyethyl isocyanurate triacrylate, 3 parts of phenoxy resin with a molecular weight of approximately 30,000, 60 parts of HN-5500, 60 parts of vinyltoluene,
A composition was obtained by adding 0.3 parts of di-t-butyl hydroperoxide and 0.2 parts of cobalt acetylacetonate as catalysts. The initial viscosity of this composition is 25
It was 150 centipoise in °C.

The pot life of the composition (medium) was determined by leaving the selected composition in a constant temperature and humidity chamber at a temperature of 25° C. and a relative humidity of 35%, and periodically measuring the viscosity.
The number of days until the viscosity reached 400 centipoise was defined as the pot life.

As a result, this impregnated resin showed a pot life of 6 months or more.

Next, this resin was heated to 120℃ for 6 hours, then heated to 150℃.
A cured product was obtained by heating for 16 hours.

The bending strength of this cured product is 25 based on JIS K6911.
℃ shows 11Kg/mm ² , and after being left at an ambient temperature of 180℃ for 16 days, the heating weight loss based on JIS C2103 is 1.0
%, and the dielectric loss tangent based on JIS C2103 is 100℃
It was a good value of 1% or less.

Example 2 Terminal carboxylic acid polybutadiene (average molecular weight
3000) 135g vs. GY-255 (manufactured by Ciba) 1050g
was added and reacted at 150°C for 2 hours to obtain a polybutadiene-modified epoxy compound. To 100 parts of this polybutadiene-modified epoxy compound, 30 parts of trihydroxyethyl isocyanurate trimethacrylate, 20 parts of triallyl trimellitate, 0.2 parts of phenoxy resin with a molecular weight of about 30,000, and methyl hymic acid anhydride (manufactured by Hitachi Chemical Co., Ltd.) ), 0.5 part of dicumyl peroxide as a catalyst, and 0.2 part of BF ₃ -monoethylamine complex were added to obtain a composition.

The initial viscosity of this composition was 120 centipoise at 25°C.

Example 1 shows the pot life of the impregnated resin in the composition.
When measured using the same method as above, it was over 6 months.

Next, this resin was heated at 120℃ for 6 hours and then at 150℃.
A cured product was obtained by heating for 16 hours.

When the physical properties of this cured product were measured in the same manner as in Example 1, the bending strength was 12 Kg/mm ² at 25°C, and the weight loss on heating after being left at an ambient temperature of 180°C for 16 days was 1.5.
%, and the dielectric loss tangent was 1% or less at 100°C, which was good.

Example 3 Terminal carboxylic acid polybutadiene (average molecular weight
875 g of DER-332 (manufactured by Dow) was added to 50 g of 1000) and reacted at 150° C. for 2 hours to obtain a polybutadiene-modified epoxy compound. For 100 parts of this polybutadiene-modified epoxy compound, 20 parts of trimethylolpropane triacrylate, styrene
100 parts, 0.5 parts of phenoxy resin with a molecular weight of about 30,000,
A composition was obtained by adding 75 parts of HN-2200 (manufactured by Hitachi Chemical Co., Ltd.), 0.3 part of dicumyl peroxide as a catalyst, and 0.2 part of BF ₃ monoethylamine complex.

The initial viscosity of the resulting composition was 80 centipoise at 25°C.

Example 1 shows the pot life of the impregnated resin in the composition.
As a result of measurement using the same method as above, it was found to be 6 months or more.

Next, this resin was heated at 120℃ for 6 hours and then at 150℃.
A cured product was obtained by heating for 16 hours.

The physical properties of this cured product were measured in the same manner as in Example 1, and the bending strength was 11.5 Kg/mm ² at 25°C, and the weight loss on heating after being left at an ambient temperature of 180°C for 16 days was 2.5.
%, and the dielectric loss tangent was 1% or less at 100°C, which was good.

Example 4 Terminal carboxylic acid polybutadiene (average molecular weight
A polybutadiene-modified epoxy compound was obtained by adding 756 g of CY-179 (manufactured by Ciba) to 135 g of 1000) and reacting at 150°C for 2 hours. To 100 parts of this polybutadiene-modified epoxy compound, 20 parts of triallylisocyanurate, 30 parts of trimethylolpropane triacrylate, 50 parts of vinyltoluene, 1 part of phenoxy resin with a molecular weight of about 3000, QH-200 (manufactured by Nippon Zeon Co., Ltd.) 85 parts, dicumyl peroxide 0.5 part as catalyst, chromium acetylacetonate 0.2
A composition was obtained.

The initial viscosity of this composition was 50 centipoise at 25°C.

In addition, as a result of measuring the pot life of the impregnated resin in this composition by the same method as in Example 1, it was found that the pot life was 6.
It showed more than a month.

Next, this resin was heated at 120℃ for 6 hours and then at 150℃.
A cured product was obtained by heating for 16 hours.

The physical properties of this cured product were measured in the same manner as in Example 1, and the bending strength was 11.0 Kg/mm ² at 25°C, and the weight loss on heating after being left at an ambient temperature of 180°C for 16 days was 2.6.
%, and the dielectric loss tangent was 1% or less at 100°C, which was good.

Comparative Example 1 85 parts of HN-2200 were blended with 100 parts of Epicoat 828, and 0.3 parts of benzyldimethylamine was added as a catalyst to obtain an impregnating composition.

This impregnating composition had a high viscosity of 600 centipoise at 25°C, and required heating when used at a temperature below 400 centipoise. Also the temperature is 40℃
Its pot life was less than a month.

Comparative Example 2 100 parts of Epicote 828 was blended with 85 parts of HN-2200, 25 parts of phenyl glycidyl ether was used as a low viscosity diluent, and benzyl dimethylamine was used as a catalyst.
0.3 part was added to prepare a composition for impregnation.

This composition had an initial viscosity of 130 centipoise at 25°C, but a pot life of less than 2 months, as measured in the same manner as in Example 1.

Further, this composition was heated at an ambient temperature of 150° C. for 16 hours to obtain a cured product.

The physical properties of this cured product were measured in the same manner as in Example 1. The bending strength was 9 Kg/mm ² at 25°C, and the weight loss after heating after being left at 180°C for 16 days was 9.0.
%, and the dielectric loss tangent was 3% or more at 100°C.

As described above, this composition exhibited extremely poor physical properties compared to the compositions of Examples.

Comparative Example 3 Terminal carboxylic acid polybutadiene (average molecular weight
3000) 760g of Epicoat 828 was added to 135g and reacted at 150°C for 2 hours to obtain a polybutadiene-modified epoxy compound. A composition was obtained using the same composition as in Example 1, except that the amount of vinyltoluene was changed to 700 parts with respect to 100 parts of this polybutadiene-modified epoxy compound.

The initial viscosity of this composition was as low as 5 centipoise at 25°C, and the pot life was more than 6 months.
The cured product obtained by heating at 120℃ for 6 hours and then at 150℃ for 16 hours has a bending strength of 8Kg/mm ² and an ambient temperature.
After being left at 180°C for 16 days, the weight loss on heating was 5%, and the dielectric loss tangent was 3% or more at 100°C, indicating lower physical properties compared to the compositions of Examples.

[Effects of the Invention] As explained above, when the thermosetting resin composition of the present invention is used, it has a lower viscosity and a longer pot life than conventional epoxy resins, and the cured product has excellent physical properties. When applied to coil impregnation for large rotating machines such as generators, it has excellent high-temperature properties.

Claims (1)

[Claims] 1 General formula (): 100 parts by weight of a polybutadiene-modified epoxy compound obtained by reacting a terminal dicarboxylic acid polybutadiene represented by the formula (wherein n represents an integer of 5 to 60) with an epoxy compound having at least two epoxy groups in one molecule. 5 to 200 parts by weight of a polyfunctional vinyl monomer having at least two (meth)acrylic or allyl groups in one molecule,
A thermosetting resin composition comprising 0.1 to 10 parts by weight of a phenoxy resin and 30 to 150 parts by weight of a cyclic liquid acid anhydride. 2 For 100 parts by weight of the thermosetting resin composition,
2. The thermosetting resin composition according to claim 1, wherein not more than 200 parts by weight of a vinyl monomer having one vinyl group per molecule is blended. 3. The molecular weight of the phenoxy resin is 15,000 to 60,000.
The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition is within the range of .