JPH07109334A - Epoxy rein, epoxy resin composition and cured product thereof - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin useful as a laminating material, etc., having low dielectric constant, excellent heat resistance and water resistance, comprising a specific chemical structure. CONSTITUTION:This epoxy resin is shown by formula I ((n) is positive integer; G is glycidyl; R is H, halogen,1-4C alkyl or aryl; X is H or glycidyl; 0-95% of X is glycidyl). The epoxy resin, for example, is obtained by reacting a compound of formula II with an epihalohydrin in the presence of an alkali metal hydroxide and reacting the prepared low-molecular weight epoxy resin of formula III in the presence of a basic catalyst. The epoxy resin is mixed with a curing agent and a curing promoter to provide an epoxy resin composition.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an epoxy resin, an epoxy resin composition and a cured product thereof,
The epoxy resin composition of the present invention is extremely useful for a wide range of applications such as laminate materials, molding materials, casting materials, composite materials, paints, adhesives and resists.

[0002]

2. Description of the Related Art Epoxy resins are cured with various curing agents to form cured products having excellent mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties, etc. It is used in a wide range of fields, including molding materials and casting materials.

However, in recent years, particularly with the development of electric and electronic fields, further improvement in various properties such as heat resistance, water resistance, and low dielectric constant has been demanded, and in order to improve these various properties, epoxy resin is required. Many proposals have been made for a curing agent for epoxy resin and a composition thereof, but it is still insufficient.

[0004]

Provided is a highly reliable epoxy resin which gives its cured product excellent properties such as heat resistance, water resistance and low dielectric constant.

[0005]

As a result of earnest research on a method of imparting or improving the above-mentioned properties, the present inventors have found a novel epoxy resin that can achieve the above-mentioned objects and completed the present invention. That is, the present invention relates to formula (1)

[0006]

[Chemical 2]

(In the formula, n represents an average value and represents a positive number.
Represents a glycidyl group. Each R represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group, and each R may be the same or different from each other. Further, each X represents a hydrogen atom or a glycidyl group, and each X may be the same or different from each other, but 0% or more and 95% or less of X is a glycidyl group. ) Epoxy resin represented by

(2) An epoxy resin composition comprising an epoxy resin, a curing agent, and optionally a curing accelerator, wherein the epoxy resin of the formula (1) is contained as the epoxy resin component. Composition,
(3) An epoxy resin composition described in (2) prepared for a laminated board, and (4) a cured product of the epoxy resin composition described in (2) or (3) above.

The epoxy resin represented by the formula (1) is represented by, for example, the formula (2)

[0010]

[Chemical 3]

(In the formula, n, G and R have the same meanings as in formula (1).)

It can be obtained by reacting the compound represented by ## STR1 ## with epihalohydrin in the presence of dimethyl sulfoxide, a quaternary ammonium salt or 1,3-dimethyl-2-imidazolidinone and an alkali metal hydroxide. . The present inventors have found that the alcoholic hydroxyl group of the epoxy resin represented by the formula (2) is more reactive than that of general alcohols, and for example, dimethyl sulfoxide, quaternary ammonium salt or 1,3 -By coexisting dimethyl-2-imidazolidinone and an alkali metal hydroxide, surprisingly, in the reaction between the alcoholic hydroxyl group and the epoxy group present in the system, the reaction with only the epoxy group derived from epihalohydrin It was found that the alcoholic hydroxyl groups of the epoxy resin represented by the formula (2) can be epoxidized to a desired ratio by selectively controlling the amount of the alkali metal hydroxide, and thus the present invention is completed. Came to.

The details of the present invention will be described below. As a method for obtaining the epoxy resin represented by the formula (2) used as a raw material in the present invention, for example, a formula (3) obtained by reacting an excess phenol with dicyclopentadiene

[0014]

[Chemical 4]

(In the formula, R has the same meaning as in formula (1).)

A method of epoxidizing the phenolic hydroxyl group of the compound represented by the formula (1) with epihalohydrin is mentioned.

When the reaction (condensation) of dicyclopentadiene with phenols is carried out, the amount of phenols used is preferably 3 to 30 relative to 1 mol of dicyclopentadiene.
The range is 5 to 20 mol, particularly preferably 5 to 20 mol.

In the above condensation reaction, it is preferable to use an acid catalyst, and various acid catalysts can be used, but boron trifluoride, anhydrous aluminum chloride, zinc chloride,
Lewis acids such as sulfuric acid and titanium chloride are preferable, and boron trifluoride and anhydrous aluminum chloride are particularly preferable. This acid catalyst may be used alone or in combination of two or more kinds. The amount of these acid catalysts used is not particularly limited, but can be selected in the range of 0.001 to 0.1 mole times the amount of dicyclopentadiene used. When these acid catalysts are added to the reaction system, it is possible to add them to the heated melt of phenols in advance or dilute them with an appropriate solvent and gradually add them.

Since many of the phenols used in this reaction are easily oxidized, it is preferable to purge the inside of the system with nitrogen gas or the like during a series of reaction operations. Further, this condensation reaction is often accompanied by a large amount of heat generation, and usually the above acid catalyst is added to the heated melt or solvent melt of phenols in advance, and dicyclopentadiene is introduced into the reaction system while checking the reaction temperature. It is preferable.

The condensation reaction in the presence of the acid catalyst is preferably carried out in the range of 40 to 180 ° C., particularly preferably 80.
The reaction time is usually 0.5-1.
It can be selected within the range of 0 hours. Further, these reactions can be carried out in the presence of a solvent inert to the reaction such as nitrobenzene, diphenyl ether, dichlorobenzene and carbon disulfide. Further, the reaction product thus obtained is neutralized so that the inside of the system becomes neutral or washed repeatedly with water in the presence of a solvent, and after water is separated and drained, the solvent and unreacted substances are removed under heating and reduced pressure. By doing so, the compound represented by the formula (3) is obtained.

As a method for obtaining the epoxy resin represented by the formula (2), a known method can be adopted. For example, by adding an alkali metal hydroxide to a dissolved mixture of a compound represented by the formula (3) and excess epihalohydrin, or by reacting at a temperature of 20 to 120 ° C. while adding the alkali metal hydroxide, the formula (4)

[0022]

[Chemical 5]

(In the formula, G and R have the same meanings as in formula (1).)

After obtaining the low molecular weight epoxy resin represented by the formula (3), the compound represented by the formula (3) and the compound having a temperature of 70 to 200 ° C. are melted in a molten state or in a solvent in the presence of a basic catalyst. It can be obtained by reacting at temperature.

In the reaction for obtaining the low molecular weight epoxy resin represented by the formula (4), an aqueous solution of the alkali metal hydroxide may be used, and in that case, the aqueous solution of the alkali metal hydroxide is continuously added. In the reaction system, water and epihalohydrin may be continuously distilled off under reduced pressure or normal pressure, and the liquid may be separated to remove water and the epihalohydrin may be continuously returned to the reaction system.

Further, a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide or trimethylbenzylammonium chloride is added as a catalyst to a dissolved mixture of the compound represented by the formula (3) and epihalohydrin, and the mixture is added at 50 to 150 ° C. The solid or aqueous solution of an alkali metal hydroxide is added to the halohydrin ether compound obtained by the reaction in step 1, and the mixture is added again to 20 to 120.
A method in which the reaction is carried out at a temperature of ° C. and dehydrohalogenation (ring closure) is also possible.

Usually, the amount of epihalohydrin used in these reactions is usually 1 to 20 mol, preferably 2 to 10 mol per 1 equivalent of hydroxyl group of the compound represented by the formula (3). The amount of the alkali metal hydroxide used is 0.8 to 15 mol, preferably 0.9 to 11 mol, based on 1 equivalent of the hydroxyl group of the compound represented by the formula (3). Further, in order to allow the reaction to proceed smoothly, it is preferable to carry out the reaction by adding an aprotic polar solvent such as dimethyl sulfone or dimethyl sulfoxide in addition to alcohols such as methanol and ethanol.

After washing these reaction products of the epoxidation reaction with water, or without heating, under heating and reduced pressure, 150 to 250.
The low molecular weight epoxy resin represented by the formula (4) can be obtained by removing epihalohydrin and other added solvents at a temperature of 10 ° C. or less.

The low molecular weight epoxy resin represented by the formula (4) is reacted with the compound represented by the formula (3) to obtain the formula (2).
In the reaction for obtaining the epoxy resin represented by, the charging ratio of each component is 0.05 to 0.9 equivalent of the compound represented by the formula (3) with respect to 1 equivalent of the epoxy resin represented by the formula (4). It is particularly preferably 0.1 to 0.85 equivalent.

Examples of the basic catalyst include triphenylphosphine, sodium hydroxide, quaternary ammonium salt,
Examples include imidazoles, etc.
0.001 to 1.0% by weight is preferable, and 0.005 to 0.5% by weight is particularly preferable, with respect to the epoxy resin represented by. When a solvent is used, methyl isobutyl ketone, toluene and the like can be mentioned.

The reaction between the alcoholic hydroxyl group of the epoxy resin represented by the formula (2) and epihalohydrin is carried out by using dimethyl sulfoxide or a quaternary ammonium salt or 1,3-dimethyl-2-imidazolidinone and an alkali metal hydroxide. Can be carried out by adjusting the amount of alkali metal hydroxide used in the presence of At that time, alcohols such as methanol and ethanol, aromatic hydrocarbons such as toluene and xylene, ketones such as methyl isobutyl ketone and methyl ethyl ketone, and cyclic and ether compounds such as tetrahydrofuran may be used together as a solvent. I do not care. Dimethyl sulfoxide, quaternary ammonium salt, 1,3-
Dimethyl-2-imidazolidinone may be used in combination.

The amount of dimethyl sulfoxide or 1,3-dimethyl-2-imidazolidinone used is preferably 5 to 300% by weight based on the compound represented by the formula (2). If it is less than 5% by weight with respect to the compound represented by the formula (2), the reaction between the hydroxyl group of the compound represented by the formula (2) and epihalohydrin is delayed, which requires a long reaction time, which is not preferable. In addition, 3 for the compound represented by the formula (2)
If it exceeds 100% by weight, the effect of increasing the amount is almost eliminated, but the volume efficiency is deteriorated, which is not preferable.

Examples of the quaternary ammonium salt include tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride and the like. The amount of the quaternary ammonium salt used is 1 equivalent of the hydroxyl group to be epoxidized in the compound represented by the formula (2). 0.3 to 5
0 g is preferred. If the amount of the hydroxyl group to be epoxidized is less than 0.3 g based on 1 equivalent, the reaction between the hydroxyl group of the compound represented by the formula (2) and epihalohydrin is delayed and a long-time reaction is required, which is not preferable. If the amount of hydroxyl groups to be epoxidized is more than 50 g per 1 equivalent of hydroxyl groups, the effect of increasing the amount will almost disappear but the cost will increase, which is not preferable.

The amount of epihalohydrin used may be equal to or more than 1 equivalent of the hydroxyl group to be epoxidized in the compound represented by the formula (2). However, if it exceeds 20 equivalents with respect to 1 equivalent of the hydroxyl group to be epoxidized, the effect of increasing the amount is almost lost and the volume efficiency is deteriorated, which is not preferable.

Examples of alkali metal hydroxides include caustic soda.
Although caustic soda, caustic potash, lithium hydroxide, calcium hydroxide and the like can be used, caustic soda is preferred. The amount of the alkali metal hydroxide used may be 1 to 1.3 times equivalent to 1 equivalent of the hydroxyl group to be epoxidized in the compound represented by the formula (2). The alkali metal hydroxide may be solid or aqueous solution. When an aqueous solution is used, the reaction can be carried out during the reaction while distilling the water in the reaction system out of the reaction system under normal pressure or reduced pressure.

The reaction temperature is preferably 20 to 100 ° C. If the reaction temperature is lower than 20 ° C, the reaction becomes slow and a long-time reaction is required. When the reaction temperature exceeds 100 ° C., many side reactions occur, which is not preferable.

The epoxy resin of the present invention can be cured alone or in combination with other epoxy resins by adding a curing agent, and if necessary, a curing accelerator and the like, as in the case of a usual epoxy resin. The curing agent that can be used in the present invention is an amine compound, an acid anhydride compound, an amide compound, a phenol compound or the like. Specific examples include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, a polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine, phthalic anhydride, trimellitic anhydride, and pyromyl anhydride. Mellitic acid, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol novolac, and modified products thereof, imidazole, BF Examples thereof include ₃ -amine complexes and guanidine derivatives. These curing agents may be used alone or in combination of two or more.

The amount of these curing agents used is preferably 0.7 to 1.2 equivalents based on the epoxy group. If the amount is less than 0.7 equivalents or more than 1.2 equivalents with respect to the epoxy groups, the curing may be incomplete and good cured physical properties may not be obtained.

A curing accelerator may be used in the epoxy resin composition of the present invention. Specific examples of the curing accelerator include imidazoles such as 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole, tertiary amines such as 2- (dimethylaminomethyl) phenol, and triphenylphosphine. And other metal compounds such as phosphine compounds, Al compounds, and Ti compounds. These may be used alone or in combination of two or more. Furthermore, various compounding materials such as inorganic or organic fillers can be added as required. The amount of these curing accelerators used is 100% epoxy resin.
If necessary, it is preferable to add 0.1 to 5.0 parts by weight to parts by weight.

The epoxy resin of the present invention, a curing agent and, if necessary, a curing accelerator are mixed to obtain the epoxy resin composition of the present invention. The epoxy resin composition can be easily prepared by the same method as a conventionally known method. The cured product can be obtained. For example, the epoxy resin of the present invention and the curing agent, filler and other additives are sufficiently mixed by using an extruder, a kneader, a roll, etc., if necessary, until they are homogeneous, and the epoxy resin of the present invention is obtained. A resin composition is obtained, the epoxy resin composition is melted and then molded using a casting or transfer molding machine or the like, and further heated at 80 to 200 ° C. for 1 to 6 hours to obtain a cured product thereof. it can.

The prepreg obtained by dissolving the resin composition of the present invention in a solvent, impregnating it into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc. and drying by heating is heated. A cured product can be obtained by press molding. For example, the epoxy resin of the present invention and a curing agent, a curing accelerator, a solvent for dilution, etc. are heated and stirred until they are uniform, and the epoxy resin composition is stirred and impregnated in a glass cloth and heated and semi-dried to remove the solvent content of the prepreg ,
A glass cloth laminate can be produced by stacking the required number of sheets and heating and pressing at 80 to 200 ° C. for 1 hour or more.

Specific examples of the solvent for dilution used at this time are preferably toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve and the like, and the amount thereof is usually 10 to 70 in the solvent diluent of the epoxy resin composition. %, Preferably 15-65% by weight.

Since the cured product thus obtained retains high heat resistance, the epoxy resin composition of the present invention can be used in a wide range of fields where heat resistance is required. Specifically, it is useful as any electric / electronic material such as an insulating material, a laminated plate, and a sealing material. It can also be used in the field of molding materials and composite materials.

[0044]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples. In the following, parts are parts by weight unless otherwise specified. The conditions for measuring the glass transition temperature, water absorption rate, and dielectric constant are as follows. Glass transition temperature thermomechanical measuring device (TMA): manufactured by Vacuum Riko Co., Ltd. TM-
7000 Temperature rising rate: 2 ° C / min Water absorption rate Test piece (cured material): Diameter 50 mm Thickness 3 mm Disc Weight increase after boiling in 100 ° C water for 20 hours (%) Dielectric constant test piece (cured material): Diameter 50 mm Thickness 3 mm Disc According to JIS K-6911 (Measurement of dielectric constant) Dielectric loss measuring device TR-10C (manufactured by Ando Electric Co., Ltd.) Frequency 1K
Measured in Hz.

Example 1 A flask equipped with a thermometer, a dropping funnel, a condenser and a stirrer was charged with 940 parts (10 moles) of phenol and melted at a temperature of 120 ° C. while purging with nitrogen gas. After the system was stabilized at 120 ° C., 7.5 parts of boron trifluoride diethyl ether complex was added as a catalyst, and 139 parts of dicyclopentadiene (pure content 95%) (1 mol) was added using a dropping funnel for 3 hours. It was added and reacted. After completion of dropping, after-reaction was further performed at 120 ° C. for 1 hour, 750 parts of dichlorobenzene was added, and the mixture was cooled to 50 ° C. Then 20% by weight monosodium dihydrogen phosphate
150 parts of aqueous solution was added, and methyl isobutyl ketone 2 was added.
250 parts were added. Next, these reaction products were transferred to a separating funnel and washed repeatedly with water to return the system to neutral. After that, use a rotary evaporator from the oil layer at 180 ° C for 5
The solvent and unreacted components are removed under reduced pressure by heating at mHg,
314 parts of a compound represented by the following formula (5) was obtained.

[0046]

[Chemical 6]

Next, 160 parts of the compound obtained in the above reaction and 370 parts of epichlorohydrin were charged in a flask equipped with a thermometer, a condenser and a stirrer while purging with nitrogen gas.
92.5 parts of dimethyl sulfoxide were charged and dissolved.
Heat to 50 ° C and add 40 parts of flaky sodium hydroxide every 4 minutes in increments of 4 parts, then add 60 ° C.
For 2 hours and at 70 ° C. for 1 hour. After completion of the reaction, washing with water is repeated, the aqueous layer is separated and removed, and the oil layer is heated under reduced pressure,
Excess epichlorohydrin was distilled off, and 450 parts of methyl isobutyl ketone was added to the residue and dissolved.

Further, this methyl isobutyl ketone solution was heated to 70 ° C., 13.3 parts of a 30 wt% sodium hydroxide aqueous solution was added, and the mixture was reacted for 1 hour, and then washed with water repeatedly to make the pH neutral. Further, the aqueous layer was separated and removed, and methyl isobutyl ketone was distilled off from the oil layer under heating and reduced pressure using a rotary evaporator to obtain 194 parts of an epoxy resin represented by the following formula (6). The obtained epoxy resin had a softening point of 62.4 ° C. and an epoxy equivalent of 229 g / eq.

[0049]

[Chemical 7]

(In the formula, G represents a glycidyl group.) The epoxy resin 183 represented by the formula (6) obtained in the above steps
Parts, 58 parts of the compound represented by the formula (5), and 120 parts of methyl isobutyl ketone were charged into a flask and dissolved by stirring, and then 0.18 parts of triphenylphosphine was added,
Methyl isobutyl ketone was distilled off under reduced pressure at 120 ° C with stirring, and the mixture was further reacted at 150 ° C for 2 hours to give an epoxy equivalent of 547 g / eq represented by the following formula (7) and a softening point of 78.6 ° C.
To obtain 241 parts of an epoxy resin.

[0051]

[Chemical 8]

(In the formula, n is 1.8 (average value) and G represents a glycidyl group.) Further, 574 parts of epichlorohydrin was added to the reaction system and dissolved by stirring, and then tetramethylammonium was added at 40 ° C. under stirring. 2.0 parts of chloride were added. Then, 15.5 parts of flaky sodium hydroxide was added to 9 parts.
The solution was added in portions over 0 minutes, and the reaction was continued for 3 hours. After the completion of the reaction, 287 parts of water was added and washed with water. After separation of the oil and water, unreacted epichlorohydrin is recovered by distillation under reduced pressure to obtain an epoxy resin (1) 229 represented by the following formula (8).
I got a part.

[0053]

[Chemical 9]

(In the formula, n is 1.8 (average value) and G and X have the same meanings as in the formula (1).) The epoxy equivalent of the obtained epoxy resin is 377 g / eq.
The softening point was 68.2 ° C. When calculated from the epoxy equivalent of the obtained epoxy resin, 60% of X in the formula (8) was a glycidyl group.

Example 2 Epoxy equivalent of 401 g in the same manner as in Example 1 except that the amount of flaky sodium hydroxide used was changed to 12.4 parts.
/ Eq, softening point 72.1 ° C 226 parts of epoxy resin (2) was obtained. In the obtained epoxy resin, 48% of X in the formula (8) was a glycidyl group calculated from the epoxy equivalent.

Examples 3 to 4, Comparative Example 1 Epoxy resins (1) to (2) obtained in Examples 1 and 2,
For comparison, bisphenol A type epoxy resin (Epomic R-301, epoxy equivalent 472 g / eq, softening point 7
Diaminodiphenylmethane (DDM) was used as a curing agent at 2 ° C. (manufactured by Mitsui Petrochemical Co., Ltd.) in the composition and parts by weight shown in Table 1, kneaded with a roll at 70 ° C. for 15 minutes, then cooled and ground. Further, after molding with a transfer molding machine, post-curing was performed to obtain a cured product of the present invention and a comparative product, and its glass transition temperature, water absorption rate and dielectric constant were measured. The results are shown in Table 1.

The transfer molding conditions and post cure conditions are as follows. Transfer molding conditions Temperature: 150 ° C. Molding pressure: 50 kg / cm ² hours: 3 minutes Post cure conditions Temperature: 160 ° C. time: 2 hours Further temperature: 180 ° C. time: 8 hours

[0058]

Table 1 Example 1 Comparative Example 3 4 1 Epoxy resin (1) 100 Epoxy resin (2) 100 Epomic R-301 100 Epoxy equivalent (g / eq) 377 401 479 DDM 10 Glass transition temperature (° C) 153 145 140 Water absorption (%) 1.47 1.56 1.87 Dielectric constant (ε) 3.35 3.32 3.87

Example 5 1410 parts (15 mol) of phenol was charged into a flask equipped with a thermometer, a dropping funnel, a condenser and a stirrer, and melted at a temperature of 120 ° C. while purging with nitrogen gas. After the system was stabilized at 120 ° C., 11.3 parts of boron trifluoride diethyl ether complex was added as a catalyst, and 209 parts of dicyclopentadiene (95% pure content).
(1.5 mol) was added and reacted using a dropping funnel over 3 hours. After completion of dropping, after-reaction was further performed at 120 ° C. for 1 hour, 1100 parts of dichlorobenzene was added and further cooled to 50 ° C. Then, 20 parts by weight of monosodium dihydrogen phosphate (230 parts by weight) was added, and further 3400 parts of methyl isobutyl ketone was added. Next, these reaction products were transferred to a separating funnel and washed repeatedly with water to return the system to neutral. Thereafter, the solvent and unreacted components were removed from the oil layer using a rotary evaporator at 180 ° C. under heating at 5 mHg and under reduced pressure to obtain 470 parts of a compound represented by the formula (5).

Then, 240 parts of the compound obtained in the above reaction and epichlorohydrin 555 were charged in a flask equipped with a thermometer, a condenser and a stirrer while purging with nitrogen gas.
And 140 parts of dimethyl sulfoxide were charged and dissolved. Flake sodium hydroxide 6 by heating to 50 degrees
0 part was added portionwise over 100 minutes, and then the mixture was further reacted at 60 ° C. for 2 hours and at 70 ° C. for 1 hour. After completion of the reaction, washing with water was repeated, the aqueous layer was separated and removed, excess epichlorohydrin was distilled off from the oil layer under heating and reduced pressure, and 680 parts of methyl isobutyl ketone was added and dissolved.

Further, this methyl isobutyl ketone solution was heated to 70 ° C., 20.0 parts of a 30 wt% sodium hydroxide aqueous solution was added, and the mixture was reacted for 1 hour, and then washed with water repeatedly to make the pH neutral. Further, the aqueous layer was separated and removed, and methyl isobutyl ketone was distilled off from the oil layer under heating and reduced pressure using a rotary evaporator to obtain 291 parts of an epoxy resin represented by the formula (6). The obtained epoxy resin had a softening point of 62.0 ° C. and an epoxy equivalent of 232 g / eq.

272 parts of the obtained epoxy resin represented by the formula (6), 77 parts of the compound represented by the formula (5), and 180 parts of methyl isobutyl ketone were charged into a flask and dissolved by stirring, and then triphenyl was added. 0.27 parts of phosphine was added, methyl isobutyl ketone was distilled off under reduced pressure at 0 ° C. under stirring, and further reaction was carried out at 150 ° C. for 2 hours to obtain 349 parts of epoxy resin having n of 1.5 in the formula (7). Obtained. The epoxy equivalent of the obtained epoxy resin is 494.
The g / eq and softening point were 72.2 ° C.

Furthermore, epichlorohydrin 770 was added to the reaction system.
2.5 parts of tetramethylammonium chloride was added at 40 ° C. with stirring. After that, 24.3 parts of flaky sodium hydroxide was added in portions over 90 minutes, and the reaction was further performed for 3 hours. After the reaction, water 3
85 parts were added and washed with water. After separation of oil and water, unreacted epichlorohydrin was collected by distillation under reduced pressure to obtain 351 parts of an epoxy resin (3) represented by the formula (8).
The epoxy equivalent of the obtained epoxy resin is 345 g / e.
q and the softening point were 67.7 degreeC. When calculated from the epoxy equivalent of the obtained epoxy resin, 60% of X in the formula (8) was a glycidyl group.

Example 6 The amount of flaky sodium hydroxide used was 1 by the same method.
342 parts of epoxy resin (4) having an epoxy equivalent of 393 g / eq and a softening point of 69.5 ° C. were obtained in the same manner as in Example 5 except that the amount was changed to 3.9 parts. The obtained epoxy resin is 40% of X in the formula (8) when calculated from the epoxy equivalent.
Was a glycidyl group.

Examples 7-8, Comparative Example 2 Epoxy resins (3)-(4) obtained in Examples 5-6,
For comparison, epoxy resin Epomic R-301, phenol novolac (PN: manufactured by Nippon Kayaku) as a curing agent, and 2-ethyl 4-methylimidazole as a curing agent,
The composition shown in Table 2 and the composition blended by weight are
Roll kneading at 70 ° C. for 15 minutes, cooling, pulverization, and further molding by a transfer molding machine, post-curing to obtain a cured product of the present invention and a comparative product, and its glass transition temperature, water absorption coefficient and dielectric constant It was measured.

The results are shown in Table 2. The transfer molding conditions and post cure conditions are as follows.

Transfer molding conditions Temperature: 160 ° C. Molding pressure: 50 kg / cm ² hours: 3 minutes Post cure conditions Temperature: 180 ° C. Time: 4 hours

[0068]

Table 2 Example 7 Example 8 Comparative Example 9 Epoxy resin (3) 100 Epoxy resin (4) 100 Epomic R-301 100 Epoxy equivalent (g / eq) 345 393 479 Curing agent (PN) 31 27 22 Curing accelerator (2E4MZ) 1 1 1 Glass transition temperature (℃) 135 130 110 Water absorption rate (%) 0.6 0.6 0.8 Dielectric constant (ε) 2.9 3.0 3.5

Compared with the epoxy resin represented by the general formula (2), the epoxy resin of the present invention is excellent in heat resistance and water resistance as shown in Tables 1 and 2 and has a low dielectric constant. Give things.

Examples 9 to 10 Epoxy resins (3) to (4) obtained in Examples 5 to 6
Dicyandiamide (DIC
Y), N, N-dimethylbenzylamine (BDMA) as a curing accelerator, methyl ethyl ketone (MEK) and methyl cellosolve (MCS) as a diluting solvent, DICY
The composition obtained by mixing dimethylformamide (DMF) in an amount shown in Table 3 for dissolution was stirred at 70 to 80 ° C for 30 minutes, and after the solid content was completely dissolved, it was further aged at 40 ° C for 16 hours. The varnish was prepared by performing. Use this varnish with glass cloth (WEA18W105F115
N: manufactured by Nitto Boseki Co., Ltd.) and then heated at 120 ° C. for 10 minutes to obtain a semi-cured prepreg. This prepreg is 8
The sheets were stacked and pressed at 170 ° C. for 60 minutes at 40 Kgf / cm ² to produce a glass cloth laminate, and the glass transition temperature, water absorption rate, solder heat resistance, and copper foil peel strength of this laminate were measured. The measurement results are shown in Table 3.

Comparative Example 3 Bromine-containing bisphenol A was used instead of the above epoxy resin.
Type epoxy resin (Epomic R-232, epoxy equivalent 483 g / eq, softening point 74 ° C, Mitsui Petrochemical Co., Ltd.)
Glass cloth laminates were prepared in the same manner as in Examples 9 to 10 using the weights shown in Table 3 and tested for similar properties.

The results are shown in Table 3. Incidentally, Examples 9 to 1
0 and Comparative Example 3 had a glass transition temperature of 50.
mm × 50 mm, 1.6 mm thick laminated plate (without copper foil)
Also, the measurement conditions of the glass transition temperature and the water absorption are the same as those in Examples 3 to 4 except that the test time is 24 hours. The conditions for measuring the solder heat resistance and the peel strength of the copper foil are as follows. Solder heat resistance Test piece (cured product): 50 mm x 50 mm Thickness 1.6 mm Laminated board (with copper foil) Boiled in 100 ° C water for 15 hours and then immersed in a solder solution at 280 ° C for 180 seconds to show the appearance of the surface. Observe. If there is no abnormality such as swelling or peeling between the surface and the layer ○ If there is any abnormality × Copper foil peeling strength Tensile tester: Toyo Baldwin Tensilon RTM
-500 Tensile mode (180 ° peeling) Measurement temperature: 30 ° C, 10
0 ° C, 120 ° C Crosshead speed: 200 mm / min Copper foil: Nikko Gourde JTC foil Thickness 35 μm

[0072]

Table 3 Table 3 Example 3 Example 4 Comparative Example 2 Epoxy resin (3) 100 Epoxy resin (4) 100 Epomic R-232 100 Epoxy equivalent (g / eq) 345 393 483 Curing agent (DICY) 3.6 3.2 2.6 Curing accelerator (BDMA) 0.3 0.3 0.3 Diluting solvent (MEK) 55 50 50 (MCS) 11 10 10 DMF 18 16 13 Glass transition temperature (℃) 145 137 126 Water absorption rate (%) 0.6 0.7 0.9 Solder heat resistance ○ ○ × Copper foil peel strength (Kg / cm) 2.3 2.5 1.9

As is clear from Table 3, the epoxy resin composition of the present invention is excellent in heat resistance and adhesive strength with a copper foil, and is superior to conventional products in terms of water resistance and dielectric constant.

[0074]

INDUSTRIAL APPLICABILITY The epoxy resin of the present invention can give a cured product having excellent heat resistance and water resistance and a low dielectric constant, and can be used for molding materials, casting materials, laminating materials, paints, adhesives, resists, etc. Very useful for a wide range of applications.

Claims (4)

[Claims] 1. A general formula (1): (In the formula, n represents an average value and represents a positive number. G represents a glycidyl group. Each R represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group, and each R represents May be the same or different from each other, and each X represents a hydrogen atom or a glycidyl group, and each X may be the same or different from each other,
0% or more and 95% or less of is a glycidyl group. ) Epoxy resin represented by. 2. An epoxy resin composition comprising an epoxy resin, a curing agent, and optionally a curing accelerator, wherein the epoxy resin composition according to claim 1 is contained as the epoxy resin component. object. 3. The epoxy resin composition according to claim 2, which is prepared for a laminated board. 4. A cured product of the epoxy resin composition according to claim 2.