JP2002179767A - Method for producing epoxy compound, epoxy resin composition and cured product thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy compound and an epoxy resin composition capable of producing a cured product having high dielectric constant and low viscosity. SOLUTION: This epoxy compound is obtained by reacting cyanoethanol with epihalohydrin in the presence of an alkali metal hydroxide. The epoxy resin composition comprises the epoxy compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an efficient method for producing a reactive diluent which gives an epoxy resin composition having a high dielectric constant.

[0002]

2. Description of the Related Art Epoxy resins can be cured with various curing agents to give cured products having generally excellent mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties, etc. It is used in a wide range of fields, such as laminates, molding materials, and casting materials. Conventionally, epoxy resins have tended to require a low dielectric constant. However, for special applications, for example, filters for electromagnetic waves for microwave ovens, conversely, methods have been attempted to improve the performance by increasing the high-frequency loss of electromagnetic waves. In such applications, the cured product of the epoxy resin composition must have a high dielectric constant. In addition, casting is a common method of using such a composition, so that the viscosity is preferably as low as possible.

[0003]

In order to solve such a problem, for example, a compound represented by the above formula (1) is introduced in JP-A-11-121036. However, the method for producing the compound represented by the formula (1) described in the patent is to add 1 mol of acrylonitrile with Michael to 1 mol of glycidol, which is an advantageous method from the viewpoint of safety and cost. I can't say.

[0004]

Means for Solving the Problems In view of the above situation, the present inventors have made intensive studies, and as a result, dissolving cyanoethanol in epihalohydrin and adding an alkali metal hydroxide to the compound represented by the above formula (1). The present inventors have found that a compound can be produced safely and efficiently, and have completed the present invention.

That is, the present invention provides a compound of the formula (1) wherein (1) cyanoethanol is dissolved in epihalohydrin and an alkali metal hydroxide is added.

[0006]

Embedded image

A process for producing an epoxy compound represented by the formula:
(2) The epoxy compound according to (1), an epoxy resin having two or more epoxy groups in a molecule, an epoxy resin composition containing a curing agent, and (3) the epoxy resin composition containing a curing accelerator. ), The epoxy resin composition according to the above (2) or (3), which contains an inorganic filler, and (5) the epoxy resin composition according to the above (2), (3) or (4).
A cured product obtained by curing the epoxy resin composition according to any one of the above.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the production method of the present invention, a reaction between cyanoethanol and epihalohydrin is carried out in the presence of an alkali metal hydroxide to obtain a compound represented by the above formula (1). Regarding the reaction.

In the reaction for obtaining the compound of the formula (1), an aqueous solution of the alkali metal hydroxide may be used. In this case, the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system. At the same time, water and epihalohydrin may be continuously flowed out under reduced pressure or normal pressure, and the liquid may be further separated, water may be removed, and epihalohydrin may be continuously returned into the reaction system.

The amount of epihalohydrin used in these reactions is usually 0.8 to 12 mol, preferably 0.9 to 11 mol, per equivalent of hydroxyl group of cyanoethanol. The amount of the alkali metal hydroxide used is usually 0.9 to 2 mol per mol of cyanoethanol,
Preferably it is 1.0 to 1.5 mol. The reaction temperature is usually from 20 to 100 ° C, and the reaction time is usually from 0.5 to 8 hours.

In the above reaction, tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride, etc.
The addition of a quaternary ammonium salt as a catalyst is preferable in that the reaction proceeds smoothly. In this case, the addition amount of the quaternary ammonium salt is usually 0.01 to 20 parts, preferably 0.05 to 10 parts, per mole of cyanoethanol.
Parts are preferred.

Alternatively, instead of the quaternary ammonium salt, an alcohol such as methanol or ethanol, or an aprotic polar solvent such as dimethyl sulfone or dimethyl sulfoxide may be added to accelerate the progress of the reaction.
When alcohols are used, they are used in an amount of usually 2 to 20% by weight, preferably 4 to 20% by weight based on the amount of epihalohydrin.
15% by weight. When an aprotic polar solvent is used, it is usually 5 to 150% by weight, preferably 10 to 140% by weight, based on the amount of epihalohydrin.

After washing the reaction product of the epoxidation reaction with water, the reaction product is usually heated to 130 ° C. using a rotary evaporator.
Thereafter, epihalohydrin, a solvent, and the like are removed at a pressure of 10 mmHg or less. After removing the once-recovered epihalohydrin and solvent, the compound represented by the formula (1) obtained by further raising the temperature is purified by molecular distillation. In this case, the temperature of the rotary evaporator is preferably 140 to 250 ° C., and the pressure is preferably 5 mmHg or less.

Hereinafter, the epoxy resin composition of the present invention will be described. The epoxy resin composition of the present invention has the formula (1)
And a curing agent containing an epoxy resin having two or more epoxy groups in one molecule.

Specific examples of epoxy resins that can be used include:
Novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, etc., may be used alone or in combination of two or more. . In the epoxy resin composition of the present invention, the mixing ratio of the compound of the formula (1) and the epoxy resin is such that the compound of the formula (1) is usually 1 to 3 in the total weight of both.
0% by weight, preferably 1.5 to 25% by weight.

The curing agent contained in the epoxy resin composition of the present invention includes, for example, amine compounds, acid anhydride compounds, amide compounds, phenol compounds and the like. Specific examples of the curing agent that can be used include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, a polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine, phthalic anhydride, and trianhydride. Mellitic acid, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol-novolak, and modified products thereof, Examples thereof include, but are not limited to, imidazole, BF ₃ -amine complex, and guanidine derivative. These may be used alone or in combination of two or more.

The amount of the curing agent used in the epoxy resin composition of the present invention is 0.1 to 1 equivalent of the epoxy group of the epoxy component (both the compound of the formula (1) and the epoxy resin).
7-1.2 equivalents are preferred. If the amount is less than 0.7 equivalents or more than 1.2 equivalents with respect to 1 equivalent of epoxy group, curing may be incomplete and good cured physical properties may not be obtained.

In the epoxy resin composition of the present invention, a curing accelerator may be used. Specific examples of the curing accelerator that can be used include 2-methylimidazole and 2-methylimidazole.
Imidazoles such as ethylimidazole and 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, 1,8-diaza-bicyclo (5,4,
0) Tertiary amines such as undecene-7; phosphines such as triphenylphosphine; and metal compounds such as tin octylate. The curing accelerator is used in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the epoxy component (both the compound of the formula (1) and the epoxy resin).

The epoxy resin composition of the present invention may contain an inorganic filler if necessary. Specific examples of the inorganic filler that can be used include silica, alumina, and talc. The inorganic filler is 0 to 10 in the epoxy resin composition of the present invention.
An amount occupying 90% by weight is used. Further, various compounding agents such as a silane coupling agent, a release agent such as stearic acid, palmitic acid, zinc stearate, and calcium stearate, and a pigment can be added to the epoxy resin composition of the present invention.

The epoxy resin composition of the present invention can be obtained by uniformly mixing the components. The epoxy resin composition of the present invention can be easily made into a cured product by a method similar to a conventionally known method. For example, the epoxy compound of the present invention, the epoxy resin and the curing agent, and if necessary, the curing accelerator, the inorganic filler and the compounding agent, if necessary, can be sufficiently extruded by using an extruder, a kneader, a roll or the like until they are uniform. To obtain an epoxy resin composition. The epoxy resin composition is melted, molded using a casting or transfer molding machine, and further heated at 80 to 200 ° C. for 2 to 10 hours to obtain a cured product. Obtainable.

Further, the epoxy resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like, and is used to prepare glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc. A prepreg obtained by impregnating a base material and heating and semi-drying can be subjected to hot press molding to obtain a cured product. The solvent in this case is usually 10 to 70% by weight, preferably 1% by weight in the mixture of the epoxy resin composition of the present invention and the solvent.
An amount occupying 5 to 70% by weight is used.

[0022]

EXAMPLES The present invention will be described more specifically with reference to the following Examples, in which parts are by weight unless otherwise specified.

Example 1 Cyanoethanol 7 was added to a flask equipped with a thermometer, a dropping funnel, a cooling tube, and a stirrer while purging with nitrogen gas.
One part, 370 parts of epichlorohydrin and 5 parts of tetramethylammonium chloride were charged and heated to 40 ° C. with stirring to dissolve. Next, 40 parts of sodium hydroxide in the form of flakes are added in portions over 100 minutes.
The reaction was carried out at a temperature of 1 hour. After the reaction is completed, the first
And the second time, water washing was performed using 100 parts of water. Then, excess epichlorohydrin was distilled off under reduced pressure by heating using a rotary evaporator at 130 ° C. and 5 mmHg. After removing the collected epichlorohydrin, the temperature of the rotary evaporator was increased to 180 ° C.
89 mm of the compound represented by the formula (1) were obtained in mmHg. The epoxy equivalent of the obtained epoxy compound (A) represented by the formula (1) was 138 g / eq.

Examples 2 and 3 Comparative Example 1 Bisphenol F type epoxy resin R as epoxy resin
E-304S (Nippon Kayaku Co., Ltd., epoxy equivalent 165)
g / eq), the epoxy compound (A) obtained in Example 1.
Kayahard MCD (Nippon Kayaku Co., Ltd.)
), 2-ethyl-4-methyl-imidazole (2E4MZ) as a curing accelerator, blended at the weight ratio shown in the composition column of Table 1, and mixed uniformly. And the viscosity at 25 ° C. was measured. A test piece was prepared by casting in a mold and curing at 80 ° C. for 2 hours, at 120 ° C. for 2 hours, and at 180 ° C. for 4 hours, and the dielectric constant was measured under the following conditions. It was shown to.

Dielectric constant: Measured according to JIS-6911.

Table 1 Example 2 Example 3 Comparative Example 1 Composition of Formulation RE-304S 90 85 100 Epoxy Compound (A) 10 1500 Kayahard MCD 109 111 108 2E4MZ 11 1 Physical Properties of Composition Viscosity (Pa · s) ) 0.45 0.39 1.03 Physical properties of cured product Dielectric constant 3.7 3.8 3.5

As described above, the viscosity of the epoxy resin composition using the epoxy compound according to the production method of the present invention was low, and the cured product thereof showed a high dielectric constant.

[0028]

The epoxy resin composition containing the epoxy compound according to the production method of the present invention provides a cured product having a low viscosity and a high dielectric constant as compared with the epoxy resin composition conventionally used generally. . Therefore, the epoxy resin composition of the present invention is extremely useful for a wide range of applications such as electric / electronic materials, molding materials, casting materials, laminate materials, paints, adhesives, resists, and optical materials.

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Claims (5)

[Claims] 1. Formula (1) wherein cyanoethanol is dissolved in epihalohydrin and an alkali metal hydroxide is added. A method for producing an epoxy compound represented by the formula: 2. An epoxy resin composition comprising the epoxy compound according to claim 1, an epoxy resin having two or more epoxy groups in one molecule, and a curing agent. 3. The epoxy resin composition according to claim 2, further comprising a curing accelerator. 4. The epoxy resin composition according to claim 2, further comprising an inorganic filler. 5. A cured product obtained by curing the epoxy resin composition according to any one of claims 2, 3 and 4.