JP2006036862A - Electrically insulating epoxy resin composition for casting, cured product thereof and thermosetting adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrically insulating epoxy resin composition for casting, providing a cured product having high heat resistance while keeping the low water absorption and excellent adhesiveness. <P>SOLUTION: The electrically insulating epoxy resin composition for casting comprises the following components (A) to (C) regulated so that the proportion of the compounded component (B) based on 1 eq. component (A) is 0.6-1.0 eq., and the proportion of the component (C) based on 100 pts. wt. of the total of the components (A) and (B) is 0.1-10 pts. wt.: (A): an epoxy resin composition consisting of 5-80wt.% alicyclic diepoxy compound (a-1) represented by general formula (I) [wherein X is a divalent group such as -SO-, -SO<SB>2</SB>-, -CH<SB>2</SB>- and -C(CH<SB>3</SB>)<SB>2</SB>-; and R<SP>1</SP>to R<SP>18</SP>are each hydrogen, a halogen, a hydrocarbon group which may contain oxygen or a halogen, or the like] and 95-20 wt.% other epoxy compounds (a-2) [with the proviso that the total of the alicyclic diepoxy compound (a-1) and the epoxy compounds (a-2) is 100 wt.%]; (B): an acid anhydride; and (C): a curing accelerator. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention can be cured by heating, and can form a cured product excellent in dimensional stability and heat resistance, an electrically insulating epoxy resin composition for casting, a cured product, and a thermosetting adhesive composition About.

The electrically insulating epoxy resin composition for casting of the present invention can form a cured product excellent in insulation, dimensional stability and heat resistance.
In the thermosetting adhesive composition of the present invention, the heat resistance is improved while maintaining the water absorption rate and the adhesiveness by adding an epoxy resin having a specific structure to a general-purpose inexpensive glycidyl type epoxy. Can be planned.

In an insulating part of an electric device, a connection part of a power cable, and the like, an epoxy resin composition cast product in which a metal electrode is embedded is installed, and a conductor is supported by the metal electrode part. Such an epoxy resin composition cast is generally produced using an epoxy resin composition comprising an epoxy resin and an acid anhydride. Of these, bisphenol-type epoxy resins are used as epoxy resins, and phthalic anhydride is used as acid anhydrides. By using these resins, crack resistance, mechanical strength, or electrical characteristics have been improved in a well-balanced manner.
In the conventional thermosetting adhesive composition, a general-purpose inexpensive glycidyl type epoxy compound or an alicyclic epoxy compound having an ester bond is used as a main component, so there is a problem that the water absorption of the cured product is high. there were. Japanese Patent Application Laid-Open No. 2002-338659 discloses a liquid epoxy resin composition using the same alicyclic diepoxy compound (a-1) in the present invention, but the electrical insulation characteristics are improved. Is not disclosed. Furthermore, Japanese Patent Application Laid-Open No. 2002-338659 discloses that the heat resistance can be improved while maintaining the low water absorption rate and excellent adhesiveness of the cured product, like the thermosetting adhesive composition of the present invention. Etc. are not disclosed.

Japanese Patent Laid-Open No. 9-77847 (Example) Japanese Patent Laid-Open No. 11-60908 (Example) JP 2002-338659 A (claims, examples)

In recent years, the trend toward smaller and ultra-high voltage devices for high-voltage devices has become stronger, and the performance required for epoxy resin composition castings has become increasingly sophisticated. In addition, there is a potential for destruction due to limitations in electrical and mechanical properties. That is, as the voltage is increased, an insulator (using an electrically insulating epoxy resin composition for casting) is subjected to a high electric field, so that further improvement in withstand voltage strength is required. Furthermore, dielectric loss (ε · tan δ · E 2) also increases as the voltage increases, and there is a concern about thermal damage of the insulator due to the generated heat. In particular, if ε · tan δ increases with increasing temperature, it is difficult to deny thermal runaway destruction. Furthermore, further improvement is required in the adhesion and crack resistance with a metal electrode embedded in an insulator.
For example, as disclosed in JP-A-9-77847, a bisphenol A type epoxy and a novolac epoxy are used as an epoxy resin, and two or more acid anhydrides are mixed to form an insulating resin. JP-60908 exemplifies the production of an insulating resin by mixing two or more acid anhydrides with bisphenol A type epoxy and crystalline epoxy as an epoxy resin.
In these cases, since the composition is solid, it is not suitable for casting or impregnation.
This time, the present inventor has excellent heat resistance, electrical characteristics without impairing the casting workability, the epoxy resin composition for electrical insulation casting containing an epoxy resin represented by the following formula (I) And found to provide a cured product having mechanical properties, and completed the present invention.
According to the present invention, an electrically insulating epoxy resin composition for casting with excellent electrical and mechanical properties can be obtained. In particular, the withstand voltage property is 30 to 50 compared with the case of using fused alumina. % Can be improved.
Moreover, with the thermosetting adhesive composition of the present invention, it is possible to improve heat resistance while maintaining a low water absorption rate and excellent adhesion of the cured product.

  Therefore, as a result of examining the various structures of the epoxy resin and the physical properties of the cured product, the present inventors have found that when a certain amount of an alicyclic epoxy compound having no ester group is blended with a glycidyl ether type epoxy, for example, a BisA type epoxy, the water absorption rate. It was possible to impart electrical insulation, adhesiveness, and heat resistance, which are the characteristics of a cured product obtained by curing an alicyclic epoxy compound while preventing an increase in the temperature.

That is, the first of the present invention is the following (A) to (C) component (A) epoxy resin composition: The alicyclic diepoxy compound (a-1) represented by the following general formula (I) is 5 to 5 80% by weight
<In the formula, X represents an oxygen atom, a sulfur atom, —SO—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —CBr ₂ —, —C (CBr ₃ ) ₂ —, It is a divalent group selected from the group consisting of —C (CF ₃ ) ₂ —, —C (Cl ₃ ) ₂ —, and —CH (C ₆ H ₅ ) ₂ —. R ^{1 to} R ¹⁸ may be the same or different from each other. These are a hydrogen atom, a halogen atom, a hydrocarbon group that may contain an oxygen atom or a halogen atom, or an alkoxy group that may have a substituent.
95-20% by weight of an epoxy compound (a-2) other than the alicyclic diepoxy compound (a-1) represented by the general formula (I) [an alicyclic diepoxy compound (a-1) and an epoxy compound (a- The total of 2) is 100% by weight]
(B) The acid anhydride (C) contains a curing accelerator, and the blending ratio of the component (B) is in the range of 0.6 to 1.0 equivalent to 1 equivalent of the component (A). Is comprised of 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of (A) and (B).
The second aspect of the present invention is the electrically insulating casting according to the above-mentioned invention 1, wherein the alicyclic diepoxy compound (a-1) represented by the general formula (I) is bicyclohexylpropane-3,3′-diepoxide. An epoxy resin composition is provided.
According to a third aspect of the present invention, there is provided the electrically insulating casting epoxy resin composition according to the first or second aspect, wherein the acid anhydride is methylhexahydrophthalic anhydride or methylnorbornene dicarboxylic acid anhydride. 4th of this invention provides the epoxy resin composition for electrically insulating castings in any one of the said invention 1-3 which a hardening accelerator contains ethylene glycol or diazabicycloundecene. According to a fifth aspect of the present invention, the epoxy compound (a-2) is at least one of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bisphenol type epoxy resin or novolak phenol type epoxy resin. The electrically insulating epoxy resin composition for casting according to any one of inventions 1 to 4 is provided. 6th of this invention provides the hardened | cured material formed by hardening | curing the epoxy resin composition for electrical insulation casting in any one of the said invention 1-5. 7th of this invention provides the hardened | cured material of the said invention 6 which has a glass transition temperature exceeding 155 degreeC with a water absorption rate of 2% or less. The eighth of the present invention is an alicyclic diepoxy compound (a-1) represented by the following general formula (I):
<In the formula, X represents an oxygen atom, a sulfur atom, —SO—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —CBr ₂ —, —C (CBr ₃ ) ₂ —, And a divalent group selected from the group consisting of —C (CF ₃ ) ₂ —, —C (Cl ₃ ) ₂ —, and —CH (C ₆ H ₅ ) ₂ —. R ^{1 to} R ¹⁸ may be the same or different from each other. These are a hydrogen atom, a halogen atom, a hydrocarbon group that may contain an oxygen atom or a halogen atom, or an alkoxy group that may have a substituent.
And an epoxy resin composition (A) comprising an epoxy compound (a-2) other than (a-1) and an acid anhydride (B).

  The cured product obtained by curing the epoxy resin composition for electrically insulating casting of the present invention can achieve high heat resistance with a Tg of about 150 ° C. or higher while maintaining low water absorption and excellent adhesiveness. .

The epoxy resin composition for electrically insulating casting of the present invention is a resin composition that can be cured by heating, and each component in the composition will be described below. The epoxy resin composition for electrically insulating casting of the present invention (hereinafter referred to as “casting epoxy resin composition”) includes an epoxy resin composition (A component) containing a specific epoxy compound and an acid anhydride (B component). ) And a curing accelerator (component C). The epoxy resin composition (component A) containing the specific epoxy compound is composed of the epoxy compound (a-1) represented by the general formula (I) and the other epoxy compound (a-2).
The epoxy compound (a-1) is represented by the following general formula (I), among which R ^{1 to} R ¹⁸ are hydrogen atoms, and —X— is —C (CH ₃ ) _2. -, I.e. 2,2-bis (3 ', 4'-cyclohexenyl) propane-diepoxide, is particularly preferably used.

Preferred examples of the alicyclic diepoxy compound (a-1) are those exemplified below.
The alicyclic diepoxy compound (a-1) represented by the general formula (I) is obtained by converting an unsaturated compound represented by the general formula (II) having a bicyclohexylpropane-3,3′-diene skeleton to an organic percarboxylic acid. Or it is manufactured by oxidizing with hydrogen peroxide solution. Among them, those epoxidized with an organic percarboxylic acid having a water content of 0.8% by weight or less are particularly preferable because they have a high epoxidation rate, a low water absorption in a cured product, and excellent electrical insulation.
In the general formula (I) and the general formula (II), X represents an oxygen atom, a sulfur atom, —SO—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —CBr ₂ —, A divalent group selected from the group consisting of —C (CBr ₃ ) ₂ —, —C (CF ₃ ) ₂ —, —C (Cl ₃ ) ₂ —, and —CH (C ₆ H ₅ ) ₂ —. is there. R ^{1 to} R ¹⁸ may be the same or different from each other. These are a hydrogen atom, a halogen atom, a hydrocarbon group which may contain an oxygen atom or a halogen atom, or an alkoxy group which may have a substituent. Among them, an epoxy compound in which X in the general formula (II) is —CH ₂ — and R ^{1 to} R ¹⁸ are all hydrogen atoms is preferably used because unsaturated compounds as raw materials are easily available.

As the epoxy compound (a-2) other than the alicyclic diepoxy compound (a-1) represented by the general formula (I), a compound having 1 or more, preferably 2 to 15 average epoxy groups in the molecule If it can be used, there is no particular limitation.
Typical examples include various bisphenol type glycidyl ethers typified by bisphenol A type and F type, and commercially available products include Epicoat 806, 807, 815, 828, 1001, 1004, 1009, 4250, YX- 4000, YX-8000 [manufactured by Japan Epoxy Resin Co., Ltd.], Adeka Resin EP-4000, 4100, 4900 [above, manufactured by Asahi Denka Kogyo Co., Ltd.], YD-128 [manufactured by Tohto Kasei]. And nuclear hydrogenated products of these bisphenol type epoxy resins, for example, HBE-100 [manufactured by Shin Nippon Rika Co., Ltd.] and the like. In addition, glycidyl ether having a cyclic aliphatic skeleton such as diglycidyl ether of cyclohexanedimethanol can be used. Examples of these include DME-100 [manufactured by Shin Nippon Rika Co., Ltd.]. Further, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate [for example, Celloxide 2021P, manufactured by Daicel Chemical Industries, Ltd.] and the like can also be used.
Further, glycidyl ethers of novolac type phenol resins obtained by copolymerization of glycidyl ethers of novolac type phenol resins and dicyclopentadiene, for example, Epicoat 152, 154, 1031S [above, manufactured by Nippon Epoxy Resin Co., Ltd.], HP-7200 [Dainippon Ink Chemical Industry Co., Ltd.]. Polycyclic aromatic glycidyl ethers such as naphthalene can also be used. An epoxy resin having a terminal epoxy group at the alicyclic skeleton portion can also be used. Examples thereof include EHPE-3150, EHPE-3150CE [Epoxidized cyclohexane polyether having a trimethylolpropane skeleton manufactured by Daicel Chemical Industries, Ltd.] and the like. Limonene dioxide can also be used. For example, a monofunctional epoxy resin such as butyl glycidyl ether can also be used. A silicone resin having an epoxy group can also be used, and examples thereof include A-186 [manufactured by Nihon Unicar Co., Ltd.], KBM303, KBM403, KBM402 [above, manufactured by Shin-Etsu Chemical Co., Ltd.]. These compounds can be used alone or in combination of two or more.

The blending ratio of the epoxy compound (a-1) and the other epoxy compound (a-2) is such that (a-1) is 5 to 80% by weight (hereinafter referred to as “%”) of the entire epoxy resin composition (component A). It is necessary to set so that it is preferably 8 to 75% by weight, and (a-2) is 95 to 20%, preferably 92 to 25% by weight. If the content of (a-1) is less than 5%, the characteristics of (a-1) do not appear, so there is no meaning to use, and even if the content of (a-1) exceeds 80%, Although excellent characteristics are maintained, it is disadvantageous in terms of economy.
In the present invention, an epoxy resin composition (component A) is composed of two types of epoxy compounds (a-1) and (a-2), and an acid anhydride and a curing accelerator described later are used together therewith. Can provide a cured product having excellent electrical characteristics, mechanical characteristics, and a high glass transition temperature of about 150 ° C. or more without impairing the target casting workability. Is obtained.
The thermosetting adhesive composition of the present invention is an epoxy resin composition comprising an alicyclic diepoxy compound (a-1) represented by the above general formula (I) and another epoxy compound (a-2). Main component is (A) and acid anhydride (B).

<Acid anhydride (B)>
As the acid anhydride (B), both solid and liquid can be used.
For example, 3 or 4-methyl-1,2,3,6-methyltetrahydrophthalic anhydride, 3 or 4-methyl-hexahydrophthalic anhydride, methyl-3,6 endomethylene-1,2,3,6-tetrahydro Examples thereof include phthalic anhydride and 5-norbornene-2,3-carboxylic acid anhydride.
Commercially available acid anhydrides (B) include Rikacid MH-700, MH, HH, TH, MT-500, HNA-100 (above, Shin Nippon Rika), HN-2200, HN-2000, HN-5000. , MHAC-P, hymic anhydride (manufactured by Hitachi Chemical Co., Ltd.), quinhard 200 (manufactured by Nippon Zeon Co., Ltd.), and the like.
The mixing ratio of the acid anhydride (component B) is an epoxy resin composition (component A) 1 containing an epoxy compound (a-2) other than the specific epoxy compounds (a-1) and (a-1). It is necessary to set in the range of 0.6 to 1.0 equivalent to the equivalent. Most preferably, it is 0.7-0.9 equivalent. That is, if the blending ratio of the acid anhydride exceeds 1.0 equivalent, the electrical characteristics decrease, and conversely if it is less than 0.6 equivalent, the heat resistance decreases. In addition, the equivalent (acid anhydride equivalent) of the said acid anhydride (B component) is set as follows. That is, one equivalent of one acid anhydride group in the acid anhydride is defined as one equivalent for one epoxy group in the component A. And the said mixture ratio is 0.6-1.0 equivalent, The epoxy group in the epoxy resin composition (A component) containing the two types of epoxy compounds of said (a-1) and (a-2). This is to the effect that the number of acid anhydride groups in the acid anhydride is 0.6 to 1.0 with respect to one.

In the above “cast epoxy resin composition”, a curing accelerator (component C) is further used as an essential component.
Examples of curing accelerators include phosphorus-based triphenylphosphine, amine-based benzyldimethylamine, tetrabutylammonium bromide, tetrabenzylammonium bromide, imidazole-based 2-ethyl-4-methyl-imidazole, 2, 3 -Dihydro-1H-pyrrolo [1,2a] benzimidazole, 1-cyanoethyl-2-methyl-imidazole, 1,8-diazabicyclo (5,4,0) undecene and derivatives thereof such as U-CAT SA1, U -CAT SA-102, U-CAT SA-5003, U-CAT SA-5002, U-CAT SA-603, U-CAT18X, etc. can be mentioned.

Furthermore, the reaction can be allowed to proceed slowly by adding a group having a hydroxyl group as necessary. Examples of those having a hydroxyl group include ethylene glycol, diethylene glycol, and glycerin.
These curing accelerators can be used alone or in combination of two or more. Usually, a combination of a compound having a hydroxyl group and the other two types is used.
The amount of these curing accelerators (component C) used is 0.1 to 10 parts by weight, preferably 100 parts by weight of the total amount of the alicyclic diepoxy compound (a-1) and the epoxy compound (a-2). 0.3 to 8 parts by weight, more preferably 0.5 to 5 parts by weight.

An inorganic filler can be further added to the components (A) to (C). Examples of the inorganic filler include silica, alumina, talc, silica sand, calcium carbonate, barium sulfate and the like. These may be used alone or in combination of two or more. Among these, spherical fused silica powder and fused alumina among silica are preferably used from the viewpoint of excellent dielectric loss tangent (tan δ) and withstand voltage characteristics. That is, by using spherical fused silica powder among silicas, it has the effect of suppressing interfacial polarization and eliminating the concentration of electrical stress, thereby further improving the dielectric loss tangent (tan δ) and withstand voltage characteristics. Is obtained. In particular, when the above spherical fused silica is used, it is possible to use 99% by weight or more of particles having a particle size of 50 μm or less and an average particle size of 35 μm or less. Is effectively prevented and a cast epoxy resin composition excellent in both electrical characteristics and mechanical strength is obtained. In addition, molten alumina is generally obtained by melting in an electric furnace using Bayer method alumina or bauxite as a main raw material, and is obtained through a series of steps such as precipitation, firing, pulverization, iron removal, water washing, and drying. As in the case of using the above fused silica, it is excellent in both electrical characteristics and mechanical characteristics, and in particular, the withstand voltage characteristics are greatly improved compared to the case of using fused alumina. It is done.
The compounding amount of the inorganic filler is 0 to 80% by weight, preferably 35 to 75% by weight in the total of the “epoxy resin composition for casting” (A) to (C) of the present invention and the inorganic filler. It is indispensable to set so that it falls within the range. That is, if the blending amount of the inorganic filler exceeds 80% by weight, the viscosity becomes too high and the mixing property and the fluidity are lowered, so that the workability may be lowered.

  In addition to the above components (A) to (C) and the inorganic filler, the “cast epoxy resin composition” of the present invention includes a diluent, a plasticizer, a pigment, a release agent, a difficult agent, as necessary. Other additives such as a flame retardant can be appropriately blended. In addition, in the thermosetting adhesive composition of the present invention, other additives such as the above component (C), inorganic filler, diluent, plasticizer, pigment, mold release agent, flame retardant, etc. Can be blended appropriately. The compounding amount of the component (C) and the inorganic filler is 0 to 30 parts by weight, preferably 1 to 10 parts by weight, with respect to 100 parts by weight of the total amount of the components (A) and (B). Parts, more preferably 1 to 5 parts by weight, and the inorganic filler is 0 to 50 parts by weight, preferably 1 to 30 parts by weight, and more preferably 1 to 10 parts by weight. When the compounding amount of the component (C) exceeds 30 parts by weight or 50 parts by weight, the curability or adhesiveness is adversely affected, and various physical properties of the cured product are deteriorated.

And in order to prepare the "casting epoxy resin composition" and thermosetting adhesive composition of this invention, said each raw material is mix | blended in a predetermined ratio. For the blending, known ones such as a drive render, a ribbon blender, a Henschel mixer can be used, and the blending is usually carried out at room temperature.
The blend of the above components is prepared as a “cast epoxy resin composition” and a thermosetting adhesive composition by stirring and mixing while excluding bubbles under vacuum heating. The temperature at the time of stirring and mixing is usually set to 10 to 60 ° C.

  If the set temperature at the time of preparation is less than 10 ° C., the viscosity is too high to make uniform stirring / mixing work difficult. Conversely, if the temperature at the time of preparation exceeds 60 ° C., a curing reaction occurs and Type epoxy resin composition "and thermosetting adhesive composition are not obtained, which is not preferable. When stirring and mixing, a general-purpose device such as a uniaxial or multi-axial extruder, kneader, or dissolver equipped with a decompression device can be used, for example, by stirring and mixing for about 10 minutes. .

  In addition to the components (A), (B) and (C), which are essential components, the “cast epoxy resin composition” and the thermosetting adhesive composition of the present invention have performance as required. Coloring pigments and extender pigments, dyes in amounts that do not significantly disturb; modified resins such as polyol resins, phenol resins, acrylic resins, polyester resins, polyolefin resins, epoxy resins, and epoxidized polybutadiene resins; inorganic or organic resin fine particles ; A solvent etc. can be mix | blended.

  Moreover, when mix | blending a modified resin, this modified resin is 0.1 to 20 weight normally with respect to 100 weight part of total amounts of two types of epoxy compounds (a-1) and (a-2). Parts, especially 5 to 10 parts by weight.

  The curing conditions of the above “cast epoxy resin composition” and the thermosetting adhesive composition can be cured by heating for about 3 to 12 hours at 80 to 220 ° C., preferably 100 to 200 ° C. . The cured product thus obtained has a water absorption of 2% or less and a glass transition temperature of 150 ° C., preferably 180 ° C., more preferably 190 ° C.

The “cast epoxy resin composition” and the thermosetting adhesive composition of the present invention achieve both heat resistance and low water absorption by blending a predetermined amount of an alicyclic diepoxy compound having a specific structure, and are excellent. In addition, electrical insulation can be imparted. Because of these characteristics, the present “cast epoxy resin composition” can be used for various other applications that require transparency, adhesiveness, heat resistance, and low water absorption. For example, sealing materials such as LEDs that require transparency, infrared and visible light receiving and emitting element sealing materials, applications that require transparency, such as films and sheets related to display materials represented by LCD, And it can be used as a substitute for glass parts such as organic EL and PDP.
The thermosetting adhesive composition of the present invention can also be used for thermosetting adhesives for electronic materials, such as anisotropic conductive adhesives and sealing agents for the above display materials. Furthermore, it can also be used as a casting material for electronic parts, a capacitor, a resistor, and a coil sealing material.

(Example)
Hereinafter, the present invention will be described more specifically with reference to examples. “Parts” and “%” are both based on weight.

Production Example 1 <Production 1 of Alicyclic Diepoxy Compound (a-1)>
36 g of water, 12.0 g of sodium hydrogensulfate, 500 g of isopropylidene-4,4′-dicyclohexanol (manufactured by Aldrich), solvent in a 1 liter jacketed flask equipped with a stirrer, condenser, thermometer and nitrogen inlet As a solution, 500 g of Solvesso 150 (manufactured by Exxon Chemical) was added and dehydrated at 100 ° C.
The reaction was terminated when no more water distilled. When the reaction solution was analyzed by gas chromatography, 2,2-bis (3 ′, 4′-cyclohexenyl) propane was produced in a yield of 96%. The obtained reaction solution was washed with 500 ml of ion-exchanged water using a separatory funnel, and then the organic layer was distilled under reduced pressure to remove colorless and transparent liquid 2,2-bis (3 ′, 4′-cyclohexenyl) propane 387. 0.0g was obtained, and the purity was 96.1%.
100 g of 2,2-bis (3 ′, 4′-cyclohexenyl) propane and 300 g of ethyl acetate were charged into a 1-liter jacketed flask similar to the above, and nitrogen was blown into the gas phase while the temperature in the reaction system was increased. 307.2 g of substantially anhydrous peracetic acid in ethyl acetate (peracetic acid concentration: 29.1%, water content 0.47%) was added dropwise over about 2 hours to reach 30 ° C. After completion of peracetic acid dropwise addition, the reaction was terminated by aging at 30 ° C. for 3 hours. Further, the reaction-terminated liquid was washed with water at 30 ° C. and deboiling was performed at 70 ° C./20 mmHg to obtain 99.4 g of an alicyclic diepoxy compound (A1). The purity of 2,2-bis (3 ′, 4′-epoxycyclohexyl) propane in the alicyclic diepoxy compound (A1) was 93.4%.
The properties of the resulting alicyclic diepoxy compound (A1) are an oxirane oxygen concentration of 11.3%, a viscosity of 3,550 cP (25 ° C.), and derived from an internal double bond in the vicinity of δ4.5-5 ppm from ¹ HNMR. Peak disappeared, and the generation of a proton peak derived from an epoxy group was confirmed in the vicinity of δ2.9 to 3.1 ppm.

Production Example 2 <Production 2 of Alicyclic Diepoxy Compound (a-1)>
300 g of 4,4′-dicyclohexanol methane, 600 g of toluene, and 3 g of paratoluenesulfonic acid were added to a 1-liter jacketed flask equipped with a stirrer, a cooling tube, a thermometer, and a nitrogen introduction tube, and dehydrated at 110 ° C. .
The reaction was terminated when no more water distilled. When the reaction solution was analyzed by gas chromatography, di (3,4-cyclohexenyl) methane was produced in a yield of 96%. The obtained reaction solution was washed with 500 ml of ion exchanged water using a separatory funnel, and then the organic layer was distilled under reduced pressure to obtain 269 g of colorless and transparent liquid di (3,4-cyclohexenyl) methane.
100 g of di (3,4-cyclohexenyl) methane and 200 g of ethyl acetate were charged into a 1-liter jacketed flask similar to Production Example 2, and the temperature in the reaction system was lowered to 25 ° C. while blowing nitrogen into the gas phase. Over the course of about 3 hours, 276.2 g of a substantially anhydrous peracetic acid ethyl acetate solution (peracetic acid concentration: 29.1%, moisture content 0.47%) was added dropwise. After completion of peracetic acid dropwise addition, the reaction was terminated by aging at 30 ° C. for 4 hours. Further, the reaction-terminated liquid was washed with water at 30 ° C. and deboiling was performed at 70 ° C./30 mmHg to obtain 106.4 g of an alicyclic diepoxy compound (A2). The purity of di (3,4-epoxycyclohexyl) methane in the alicyclic diepoxy compound (A2) was 91.8%.
The properties of the resulting alicyclic diepoxy compound (A2) are an oxirane oxygen concentration of 13.8%, a viscosity of 2,590 cP (25 ° C.), and are derived from a double bond in the vicinity of δ4.5 to 5 from ¹ HNMR. The peak disappeared, and the generation of a proton peak derived from the epoxy group was confirmed in the vicinity of δ2.9 to 3.3.

Production Example 3 <Production 3 of Alicyclic Diepoxy Compound (a-1)>
Di (3,4-cyclohexenyl) was prepared in the same manner as in Production Example 2 except that 400 g of hydrogenated bisphenol sulfone (that is, 4,4′-dicyclohexanol sulfone) and 500 g of Solvesso 150 (manufactured by Exxon Chemical) were used as a solvent. ) 330 g of sulfone was obtained, and its purity was 92.2%.
100 g of this reaction product and 300 g of ethyl acetate were charged into a 1-liter jacketed flask similar to the above, and while the nitrogen gas was blown into the gas phase part, the temperature in the reaction system was adjusted to 40 ° C. over about 2 hours. In particular, 242.7 g of an ethyl acetate solution of anhydrous peracetic acid (peracetic acid concentration: 29.1%, moisture content 0.47%) was added dropwise. After the completion of peracetic acid dropwise addition, the reaction was terminated by aging at 40 ° C. for 4 hours. Further, the crude liquid was washed with water at 30 ° C. and deboiling was performed at 70 ° C./30 mmHg to obtain 97.0 g of an alicyclic diepoxy compound (A3). The purity of di (3,4-epoxycyclohexyl) sulfone in the alicyclic diepoxy compound (A3) was 90.3%.
The properties of the resulting alicyclic diepoxy compound (A3) are an oxirane oxygen concentration of 10.8%, a viscosity of 6,700 cP (25 ° C.), and are derived from double bonds around δ4.5-5 from ¹ HNMR. The peak disappeared, and the generation of a proton peak derived from the epoxy group was confirmed in the vicinity of δ2.9 to 3.3.

Example 1
YD-12830 parts by weight, 70 parts by weight of the alicyclic diepoxy compound (A1) of Synthesis Example 1, 5 parts by weight of EHPE-3150, and MH-700 parts by weight are blended and kept at 25 ° C. and stirred for 15 minutes. A thermosetting adhesive composition was obtained.
Examples 2 to 10 and Comparative Examples 1 to 3
Each thermosetting adhesive composition was obtained in the same manner as in Example 1 except that the formulations shown in Tables 1 and 2 were used.

In Table 1, abbreviations are as follows.
YD-128: manufactured by Tohto Kasei, bisphenol A type epoxy resin (epoxy equivalent 190, viscosity 13600 mPa · s / 25 ° C.)
EP-806: Bisphenol-type glycidyl ether [Epicoat EP-806, epoxy equivalent 166, manufactured by Nippon Epoxy Resin Co., Ltd.]
EHPE-3150: Epoxidized cyclohexane polyether having a trimethylolpropane skeleton [epoxy equivalent 178, manufactured by Daicel Chemical Industries, Ltd.]
MH-700: Methylhexahydrophthalic anhydride (trade name Ricacid MH-700: manufactured by Shin Nippon Chemical Co., Ltd.)
EG: Ethylene glycol (curing accelerator)
BDMA: benzyldimethylamine (curing accelerator)

The curing conditions in each example are as follows.
Examples 1, 3, 4, 6 and Comparative Example 1: 110 ° C. × 2 hours + 180 ° C. × 2 hours Examples 2 and 5: 120 ° C. × 3 hours + 160 ° C. × 2 hours

In Table 2, abbreviations are as follows. What is common to Table 1 is as described above.
HBE-100: Nuclear hydrogenated product of bisphenol type epoxy resin [Epoxy equivalent 216, manufactured by Shin Nippon Rika Co., Ltd.]
DME-100: Diglycidyl ether of cyclohexanedimethanol [epoxy equivalent 157, manufactured by Shin Nippon Rika Co., Ltd.]
CEL-2021P: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate [Daicel Chemical Industries, Ltd.]
U-CAT 5003: Phosphonium salt-based curing accelerator [manufactured by San Apro]

Curing conditions Examples 7 and 8 and Comparative Example 2: 110 ° C. × 4 hours + 180 ° C. × 2 hours Examples 9, 10 and Comparative Example 3: 120 ° C. × 3 hours + 160 ° C. × 2 hours

Production of test plate A test plate was produced in the following manner using each thermosetting adhesive composition obtained in the above Examples and Comparative Examples.
A 1 mm Teflon (registered trademark) mold frame is placed on a glass plate on which a release film is stretched, and a thermosetting adhesive composition is cast. A glass plate on which a release film was stretched was placed thereon and cured at the predetermined temperature to obtain a test plate. Each of the obtained test plates was tested based on the following test method (excluding adhesiveness).

<Heat resistance test method>
Glass transition point: TMA SS6100 (manufactured by Seiko Instruments Inc.) was used for measurement at a load of 50 g and a heating rate of 5 ° C./min.
Water absorption rate: The water absorption rate was measured from the change in weight after standing for 96 hours at 120 ° C. and 95% humidity using a pressure cooker tester manufactured by Tabay Espec.
Adhesiveness: After applying the thermosetting adhesive composition to an aluminum plate (A1050P) to a size of 10 × 12.5 mm, the coated surfaces are bonded together and cured under the above specified conditions, and then RTC- manufactured by Orientec Adhesion was evaluated with a tensile tester at 1310A at a pulling speed of 1 mm / min. The unit is kg / cm ² .
The results of the above test are shown in Table 3 below.

Claims (8)

The following (A)-(C) component (A) epoxy resin composition 5-80 weight% of alicyclic diepoxy compounds (a-1) represented by the following general formula (I)
<In the formula, X represents an oxygen atom, a sulfur atom, —SO—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —CBr ₂ —, —C (CBr ₃ ) ₂ —, It is a divalent group selected from the group consisting of —C (CF ₃ ) ₂ —, —C (Cl ₃ ) ₂ —, and —CH (C ₆ H ₅ ) ₂ —. R ^{1 to} R ¹⁸ may be the same or different from each other. These are a hydrogen atom, a halogen atom, a hydrocarbon group that may contain an oxygen atom or a halogen atom, or an alkoxy group that may have a substituent.
95-20% by weight of an epoxy compound (a-2) other than the alicyclic diepoxy compound (a-1) represented by the general formula (I) [an alicyclic diepoxy compound (a-1) and an epoxy compound (a- The total of 2) is 100% by weight]
(B) The acid anhydride (C) contains a curing accelerator, and the blending ratio of the component (B) is in the range of 0.6 to 1.0 equivalent to 1 equivalent of the component (A). An epoxy resin composition for electrically insulating casting, characterized by comprising 0.1 to 10 parts by weight per 100 parts by weight of the total amount of (A) and (B).   The epoxy resin composition for electrically insulating casting according to claim 1, wherein the alicyclic diepoxy compound (a-1) represented by the general formula (I) is bicyclohexylpropane-3,3'-diepoxide.   The epoxy resin composition for electrically insulating casting according to claim 1 or 2, wherein the acid anhydride is methylhexahydrophthalic anhydride or methylnorbornene dicarboxylic acid anhydride.   The epoxy resin composition for electrically insulating casting according to any one of claims 1 to 3, wherein the curing accelerator contains ethylene glycol or diazabicycloundecene.   The epoxy compound (a-2) is at least one of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bisphenol type epoxy resin or novolak phenol type epoxy resin. The epoxy resin composition for electrically insulating casting according to any one of the above.   Hardened | cured material formed by hardening | curing the epoxy resin composition for electrical insulation castings in any one of Claims 1-5.   The hardened | cured material of Claim 6 which has a glass transition temperature exceeding 155 degreeC with a water absorption rate of 2% or less. Alicyclic diepoxy compound (a-1) represented by the following general formula (I)
<In the formula, X represents an oxygen atom, a sulfur atom, —SO—, —SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —CBr ₂ —, —C (CBr ₃ ) ₂ —, And a divalent group selected from the group consisting of —C (CF ₃ ) ₂ —, —C (Cl ₃ ) ₂ —, and —CH (C ₆ H ₅ ) ₂ —. R ^{1 to} R ¹⁸ may be the same or different from each other. These are a hydrogen atom, a halogen atom, a hydrocarbon group that may contain an oxygen atom or a halogen atom, or an alkoxy group that may have a substituent.
And a thermosetting adhesive composition comprising an epoxy resin composition (A) and an acid anhydride (B) comprising an epoxy compound (a-2) other than (a-1).