JPH06248055A - Epoxy resin, epoxy resin composition and its cured product - Google Patents

Abstract

PURPOSE:To obtain the subject resin consisting of a specific epoxy resin, having prescribed physical properties, excellent in heat resistance, toughness and water resistance and useful for sealant, etc., of electric and electronic parts, etc. CONSTITUTION:This resin composition consists of an epoxy resin of the formula [(n) is integer exhibiting average value; R is H or Br; X is or glycidyl, with the proviso that 10-95% of X is glycidyl]. In this resin composition, (A) when R are all H, (i) the weight ratio of a binuclear body is 0-4% and softening point is 80-90 deg.C or (ii) the weight ratio of the binuclear body is 4-8% and the softening point is 70-80 deg.C or (iii) the weight ratio of the binuclear body is 8-12% and the softening point is 60-70 deg.C, and (B) when part of R is Br, bromine content to whole resin is 15-30wt.% and (IV) the weight ratio of the binuclear body is 0-9% and the softening point is 80-100 deg.C or (V) the weight ratio of binuclear body is 9-18% and the softening point is 60-80 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin and an epoxy resin composition which give a cured product excellent in heat resistance, toughness and water resistance, and a cured product thereof. The resin and the resin composition of the present invention are molding materials. , It is extremely useful for a wide range of applications such as casting materials, laminated materials, composite materials, paints, adhesives and resists.

[0002]

2. Description of the Related Art Epoxy resins, when cured with various curing agents, generally become cured products having excellent mechanical properties, water resistance, chemical resistance, heat resistance, and electrical properties, and are used as adhesives and paints. It is used in a wide range of fields such as laminates, molding materials, and casting materials. Conventionally, liquid and solid bisphenol A type epoxy resins obtained by reacting bisphenol A with epichlorohydrin have been used as the most industrially used epoxy resins. In addition to liquid bisphenol A type epoxy resin, Tetrabumu bisphenol
A flame-retardant solid epoxy resin obtained by reacting the resin A is industrially used as a general-purpose epoxy resin.

[0003]

However, the general-purpose epoxy resin as described above has the drawback that as the molecular weight increases, the toughness of the cured product obtained by using it increases, but the heat resistance decreases. . Further, although a cured product obtained by mixing a polyfunctional epoxy resin such as cresol novolac epoxy resin in order to compensate for the decrease in heat resistance has high heat resistance, it has a drawback that toughness decreases and water absorption increases. . On the other hand, with the recent remarkable development of the electronic industry and the like, the heat resistance, toughness and water resistance required for the electric insulating materials used for these have become more and more severe, and the emergence of epoxy resins excellent in these properties Is awaited.

[0004]

In view of these circumstances, the present inventors have earnestly studied for an epoxy resin which gives a cured product excellent in heat resistance, toughness and water resistance, and as a result, have a specific structure, and It was found that an epoxy resin having a softening point and a binuclear content in a specific range imparts excellent heat resistance, toughness and water resistance to the cured product, and thus the present invention has been completed. It was.

That is, the present invention is based on the equation (1) (1)

[0006]

[Chemical 2]

(In the formula, n represents an average value and represents a positive number. Each R represents a hydrogen atom or a bromine atom, and each R may be the same or different from each other. Represents a hydrogen atom or a glycidyl group, and the individual X's may be the same or different from each other.
0% or more and 95% or less are glycidyl groups. ) In the epoxy resin represented by

(A) When all R's are hydrogen atoms,
(A) the weight ratio of the binuclear body is 0% or more and less than 4% and the softening point is 80 ° C. or higher and 90 ° C. or lower, or (b) the weight ratio of the binuclear body is 4% or more and less than 8%. Yes, and softening point is 70
C or higher and lower than 80 ° C., or (c) the weight ratio of the binuclear body is 8% or higher and lower than 12%, and the softening point is 60 ° C. or higher and lower than 70 ° C.,

(B) When at least a part of R is a bromine atom, the bromine content is 15 to 30% by weight based on the whole resin, and the weight ratio of the (d) binuclear compound is 0% or more and 9% or more. And the softening point is 80 ° C. or higher and 100 ° C. or lower, or (e) the weight ratio of the binuclear body is 9% or higher and lower than 18%, and the softening point is 60 ° C. or higher and lower than 80 ° C. Epoxy resin characterized by

(2) An epoxy resin composition comprising an epoxy resin, a curing agent, and optionally a curing accelerator, which contains the epoxy resin of the above item (1) as the epoxy resin component. The present invention relates to a resin composition, (3) an epoxy resin composition according to the above item (2) for a laminated board, (4) a cured product of the epoxy resin composition according to the above (2) or (3). .

According to the present invention, a cured product having excellent heat resistance, toughness and water resistance can be obtained. In the epoxy resin of the present invention, the preferable value of n in the formula (1) is 0.5 to 8
And a particularly preferred value is 1 to 6. Also, 20 of X
% To 95% are preferably glycidyl groups, and particularly preferably 30 to 95% are glycidyl groups.

In the present invention, the weight ratio of the binuclear body means the weight% of the "compound having two benzene rings in one molecule" present in the epoxy resin, which is present in the epoxy resin. The epoxy resin of the present invention has, for example, the formula (2)

[0013]

[Chemical 3]

It can be obtained by reacting the alcoholic hydroxyl group of the compound represented by the formula (wherein n and R have the same meanings as described above) with epihalohydrin.

More specifically, the reaction of the alcoholic hydroxyl group of the compound represented by the formula (2) with epihalohydrin is carried out by using dimethyl sulfoxide or a quaternary ammonium salt or 1,
The epoxy resin of the present invention can be obtained by performing the reaction in the presence of 3-dimethyl-2-imidazolidinone and an alkali metal hydroxide and adjusting the amount of the alkali metal hydroxide used and the reaction temperature.

According to the studies by the present inventors, the alcoholic hydroxyl group of the compound of the formula (2) is more reactive than general alcohols, for example, dimethyl sulfoxide or 4
Surprisingly, the coexistence of a primary ammonium salt or 1,3-dimethyl-2-imidazolidinone and an alkali metal hydroxide surprisingly allows selective reaction between an alcoholic hydroxyl group and epihalohydrin, and further By controlling the amount of the metal hydroxide and the reaction temperature, the alcoholic hydroxyl group of the compound represented by the formula (2) can be epoxidized (glycidyl) to a desired ratio, and the epoxy resin to be obtained has a specific content. Those having a softening point and a binuclear content in the range give excellent properties to the cured product.

The reaction between the alcoholic hydroxyl group of the compound represented by the formula (2) and epihalohydrin is carried out by dimethyl sulfoxide or a quaternary ammonium salt or 1,3-dimethyl-2-imidazolidinone and an alkali metal hydroxide. It can be carried out by adjusting the amount of alkali metal hydroxide used and the reaction temperature in the coexistence of. At that time, alcohols, aromatic hydrocarbons, ketones, cyclic compounds and ether compounds may be used in combination as the solvent. Dimethyl sulfoxide, quaternary ammonium salt, and 1,3-dimethyl-2-imidazolidinone may be used alone or in combination.

The amount of dimethyl sulfoxide or 1,3-dimethyl-2-imidazolidinone used is preferably 5% by weight to 300% by weight based on the compound represented by the formula (2). If the amount is less than 5% by weight based on 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. 30 with respect to the compound represented by the formula (2)
If it exceeds 0% by weight, the effect of increasing the amount is almost eliminated and 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 per 1 equivalent, 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, and exceeds 50 g. If the amount is increased, the effect is almost eliminated, but the cost is increased, which is not preferable.

Examples of epihalohydrin include epichlorohydrin and epibromohydrin. The amount of epihalohydrin used may be equivalent 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.

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 alkali metal hydroxide may be used in an amount of 1 to 2.0 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, particularly preferably 30 to 60 ° 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 as in the case of a normal epoxy resin and, if necessary, a curing accelerator and the like. In the epoxy resin composition of the present invention, amine compounds, acid anhydride compounds, amide compounds, phenol compounds and the like can be used as the curing agent. 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, pyromyl anhydride. Mellitic acid, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol novolac, and modified products thereof, imidazo-
And BF3 -amine complex, guanidine derivative and the like. 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 1 equivalent of the epoxy groups of the epoxy resin. If the amount is less than 0.7 equivalent or more than 1.2 equivalent to 1 equivalent of epoxy group, curing may be incomplete and good cured physical properties may not be obtained.

When using the above-mentioned curing agent, a curing accelerator may be used in combination. Examples of the curing accelerator include imidazoles, tertiary amines, phenols, metal compounds and the like. Furthermore, various compounding agents such as inorganic or organic fillers can be added as required. The amount of the curing accelerator used is preferably 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the epoxy resin.

The epoxy resin composition of the present invention is obtained by uniformly mixing the components. The epoxy resin composition of the present invention containing the epoxy resin of the present invention, a curing agent, and optionally a curing accelerator can be easily made into a cured product by the same method as a conventionally known method. For example, the epoxy resin composition of the present invention and a curing agent, a filler, and other additives are sufficiently mixed with an extruder, a kneader, a roll, etc., if necessary, until a uniform mixture is obtained. After melting, the epoxy resin composition is melted and then molded using a casting or transfer molding machine, and further 80 to 2
A cured product can be obtained by heating to 00 ° C. Further, the resin composition of the present invention is dissolved in a solvent and impregnated into a base material such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper and the like, and heat-dried to form a prepreg by hot press molding. It is also possible to obtain a cured product. According to the present invention, a cured product excellent in heat resistance, toughness and water resistance is obtained, and therefore, the epoxy resin composition of the present invention is used for a laminate, a sealing material, an adhesive, a composite material,
It can be used for various purposes such as paints.

[0027]

EXAMPLES The present invention will now be described in detail with reference to Examples and Comparative Examples. In the following, all parts are parts by weight unless otherwise specified. The binuclear body content was measured by standard gel permeation chromatography (GPC), and the softening point was measured using a METTLER model FP-80 softening point measuring device. The glass transition point, breaking energy and water absorption were measured according to JIS K-6911.

Examples 1-2 and Comparative Example 1 As the compound represented by the formula (2), a bisphenol A type epoxy resin (31) (n =) in which all R are hydrogen atoms.
5.1, epoxy equivalent 890 g / eq, softening point 103.
(1 ° C.) 351 parts (1.0 equivalent of alcoholic hydroxyl group) were dissolved in 1295 parts of epichlorohydrin, and then stirred under stirring 4
5 parts of tetramethylammonium chloride was added at 0 ° C., and 40.6 parts of 98.5% NaOH was added over 100 minutes. After the reaction was further performed for 3 hours, 650 parts of water was added to wash with water. After separation of oil and water, epichlorohydrin was distilled and recovered from the oil layer under reduced pressure to obtain an epoxy equivalent of 384 g / eq.
345 parts of Epoxy resin (1) was obtained. In the obtained epoxy resin, all R in the formula (1) are hydrogen atoms,
n = 5.1, calculated from the epoxy equivalent, 61% of X is a glycidyl group, the other is a hydrogen atom, the binuclear content is 3.1%, the softening point is 88.0 ° C. there were.

In the same manner, the amount of 98.5% NaOH used was adjusted to 60.9 parts to obtain 348 parts of epoxy resin (2) having an epoxy equivalent of 314 g / eq. In the obtained epoxy resin, all R in the formula (1) are hydrogen atoms, and n
= 5.1, 88% of X is a glycidyl group calculated from the epoxy equivalent, the others are hydrogen atoms, the binuclear content is 3.0%, and the softening point is 81.5 ° C. It was

The obtained epoxy resins (1) to
(2) Using epoxy resin (31) as a comparison, phenol novolac as a curing agent, and triphenylphosphine (TPP) as a curing accelerator, blended in the composition shown in Table 1, and kneaded with a roll at 70 ° C. for 15 minutes. , 150 ° C, 18
Transfer molding was performed for 0 seconds, and thereafter, the test piece was prepared by curing at 160 ° C. for 2 hours and then at 180 ° C. for 8 hours, and the glass transition point, breaking energy and water absorption were measured. The results are shown in Table 1. In addition, in the table, the numerical value in the column of formulation indicates part by weight.

[0031]

[Table 1] Table 1 Actual Examples Comparative Examples 1 2 1 Epoxy resin (1) 100 Epoxy resin (2) 100 Epoxy resin (31) 100 Epoxy equivalent (g / eq) 384 314 890 Epoxidation rate (%) 61 88 0 2 Nucleus content (%) 3.1 3.0 3.4 Softening point (℃) 88.0 81.5 103.1 Phenol novolac 28 34 12 TPP 1 1 1 Glass transition point (℃) 121 133 96 Fracture energy (25 ℃, Kg / mm) 141 139 119 Water absorption rate (%) 1.51 1.36 2.21

Examples 3 to 4 and Comparative Example 2 As the compound represented by the formula (2), a bisphenol A type epoxy resin (32) in which all R are hydrogen atoms (n =
3.2, epoxy equivalent 629 g / eq, softening point 84.7
Epoxy equivalent of 376 g / in the same manner as in Example 1 except that the amount of 98.5% NaOH added was 33.8 parts using 389 parts (1.0 equivalent of alcoholic hydroxyl group).
383 parts of an epoxy resin (3) of eq was obtained. In the obtained epoxy resin, all R's in formula (1) are hydrogen atoms, n = 3.2, and X is calculated from the epoxy equivalent.
Of which 49% is a glycidyl group, the others are hydrogen atoms, the binuclear content is 6.1%, and the softening point is 77.8 ° C.
Met.

In the same manner, the amount of 98.5% NaOH used was changed to 54.1 parts to obtain 386 parts of epoxy resin (4) having an epoxy equivalent of 306 g / eq. In the obtained epoxy resin, all R in the formula (1) are hydrogen atoms, and n
= 3.2, calculated from the epoxy equivalent, 80% of X is a glycidyl group, the others are hydrogen atoms, the binuclear content is 6.0%, and the softening point is 71.3 ° C. It was

The obtained epoxy resins (3) to
(4) Using epoxy resin (32) as a comparison, phenol novolac as a curing agent, and triphenylphosphine (TPP) as a curing accelerator, blended in the composition shown in Table 2 and kneading with a roll at 70 ° C. for 15 minutes. , 150 ° C, 18
Transfer molding was performed for 0 seconds, and thereafter, the test piece was prepared by curing at 160 ° C. for 2 hours and then at 180 ° C. for 8 hours, and the glass transition point, breaking energy and water absorption were measured. The results are shown in Table 2. In addition, in the table, the numerical value in the column of formulation indicates part by weight.

[0035]

[Table 2] Table 2 Actual Examples Comparative Examples 3 4 2 Epoxy resin (3) 100 Epoxy resin (4) 100 Epoxy resin (32) 100 Epoxy equivalent (g / eq) 376 306 629 Epoxidation rate (%) 49 80 0 2 Nucleus content (%) 6.1 6.0 6.4 Softening point (℃) 77.8 71.3 84.7 Phenol novolac 28 35 17 TPP 1 1 1 Glass transition point (℃) 141 150 102 Fracture energy (25 ℃, Kg / mm) 110 105 101 Water absorption rate (%) 1.31 1.26 2.20

Examples 5 to 6 and Comparative Example 3 As the compound represented by the formula (2), a bisphenol A type epoxy resin (33) in which all R are hydrogen atoms (n =
2.2, epoxy equivalent 479 g / eq, softening point 71.4
C.) 439 parts (1.0 equivalent of alcoholic hydroxyl group) was used, and the epoxy equivalent was 320 g / in the same manner as in Example 1 except that the addition amount of 98.5% NaOH was changed to 37.2 parts.
430 parts of epoxy resin (5) of eq was obtained. In the obtained epoxy resin, all R in the formula (1) are hydrogen atoms, n = 2.2, and X is calculated from the epoxy equivalent.
Of these, 55% is a glycidyl group, the others are hydrogen atoms, the binuclear content is 9.8%, and the softening point is 65.5 ° C.
Met.

In the same manner, the amount of 98.5% NaOH used was changed to 50.8 parts to obtain 441 parts of an epoxy resin (6) having an epoxy equivalent of 286 g / eq. In the obtained epoxy resin, all R in the formula (1) are hydrogen atoms, and n
= 2.2, calculated from the epoxy equivalent, 77% of X is a glycidyl group, the others are hydrogen atoms, the binuclear content is 9.6%, and the softening point 64.1 is ° C. It was

The obtained epoxy resin (5)-
(6), epoxy resin (33) for comparison, Kayahard MCD (manufactured by Nippon Kayaku Co., Ltd., methyl endomethylene tetrahydrophthalic anhydride) as a curing agent, 2E4MZ (2-ethyl-4-methylimidazole) as a curing accelerator ) Was mixed with the composition shown in Table 3, mixed and cast, and then cured at 160 ° C. for 2 hours and further at 180 ° C. for 8 hours to prepare a test piece, and the glass transition point, breaking energy and water absorption rate Was measured. The results are shown in Table 3. In addition, the numerical value in the column of the compound in the table shows a part by weight.

[0039]

[Table 3] Table 3 Actual Examples Comparative Examples 5 6 3 Epoxy resin (5) 100 Epoxy resin (6) 100 Epoxy resin (33) 100 Epoxy equivalent (g / eq) 320 286 479 Epoxidation rate (%) 55 77 0 2 Nucleus content (%) 9.8 9.6 10.3 Softening point (℃) 65.5 64.1 71.4 Kayahard MCD 50 56 33 2E4MZ 1 1 1 Glass transition point (℃) 161 187 112 Fracture energy (25 ℃, Kg / mm) 88 90 81 Water absorption rate (%) 1.31 1.33 2.20

Examples 7 to 8 and Comparative Example 4 As the compound represented by the formula (2), a part of R is a bromine atom, and the bromine content is 26% by weight based on the whole resin, and the bromine-containing bisphenol A is contained. Type epoxy resin (34) (n
= 2.8, epoxy equivalent 760 g / eq, softening point 106
C.) 551 parts (1.0 equivalent of alcoholic hydroxyl group) was used, and the epoxy equivalent was 447 g / in the same manner as in Example 1 except that the addition amount of 98.5% NaOH was changed to 40.6 parts.
545 parts of eq epoxy resin (7) were obtained. In the obtained epoxy resin, part of R in the formula (1) is a bromine atom and the other is a hydrogen atom, n = 2.8, the bromine content is 25% by weight, and when calculated from the epoxy equivalent, Of X, 58% was a glycidyl group, the others were hydrogen atoms, the binuclear content was 6.2%, and the softening point was 93.1 ° C.

In the same manner, the amount of 98.5% NaOH used was changed to 54.1 parts to obtain 553 parts of an epoxy resin (8) having an epoxy equivalent of 386 g / eq. In the obtained epoxy resin, part of R in the formula (1) is a bromine atom and the other is a hydrogen atom, n = 2.8, the bromine content is 24% by weight, and when calculated from the epoxy equivalent, 82 out of X
% Is a glycidyl group, the others are hydrogen atoms, and 2
The nuclear content was 6.0% and the softening point was 86.2 ° C.

The obtained epoxy resins (7) to (8), and the epoxy resin (34) for comparison were dissolved in methyl ethyl ketone to prepare a solution having a resin concentration of 80% by weight. A varnish-like epoxy resin composition is prepared by mixing these epoxy resin solutions with dicyandiamide as a curing agent, 2MZ (2-methylimidazole) as a curing accelerator, methylcellosolve as a solvent, and dimethylformamide in the composition shown in Table 4. did. A glass cloth (WE-18K-BZ2, manufactured by Nitto Boseki Co., Ltd.) was impregnated with this composition 11
Heat at 0 ° C for 30 minutes to obtain a B-staged prepreg, stack 9 prepregs of this prepreg at 170 ° C, 40K
A glass cloth laminate having a thickness of 1.5 mm was prepared under the molding conditions of gf / cm2 and 45 minutes, and the glass transition point and measling resistance were measured according to JIS C-6481.
The results are shown in Table 4. In addition, the numerical value in the column of the compound in the table shows a part by weight.

[0043]

[Table 4] Table 4 Actual Example Comparative Example 7 8 4 Epoxy resin (7) 80 Epoxy resin (8) 80 Epoxy resin (34) 80 Epoxy equivalent (g / eq) 447 386 760 Epoxidation rate (%) 58 82 0 Dinuclear content (%) 6.2 6.0 6.8 Softening point (° C) 93.1 86.2 106.0 Dicyandiamide 3.4 3.4 3.4 2MZ 0.08 0.08 0.08 Methyl ethyl ketone 20 20 20 Methylcellosolve 21 21 21 Dimethylformamide 21 21 21 Glass transition point (° C) 161 170 126 Resistance to measling ※ ○ ○ × * Presence or absence of abnormal appearance after 1 hour boiling and dipping in 260 ° C solder for 20 seconds ○ No abnormality × Abnormality

Examples 9 to 10, Comparative Example 5 In the compound represented by the formula (2), a part of R is a bromine atom, and the bromine content is 20% by weight based on the whole resin, and the bromine-containing bisphenol A is present. Type epoxy resin (35) (n
= 1.4, epoxy equivalent 468 g / eq, softening point 76.
Epoxy equivalent 351 g in the same manner as in Example 1 except that 650 parts (1.0 eq. Of alcoholic hydroxyl group) was used and the addition amount of 98.5% NaOH was changed to 33.8 parts.
647 parts of epoxy resin (9) of / eq was obtained. In the obtained epoxy resin, part of R in the formula (1) is a bromine atom and the other is a hydrogen atom, n = 1.4, the bromine content is 19% by weight, and calculated from the epoxy equivalent. 55% of X is a glycidyl group, the others are hydrogen atoms, the binuclear content is 15.5%, and the softening point is 68.1 ° C.
Met.

In the same manner, the amount of 98.5% NaOH used was adjusted to 60.9 parts to obtain 653 parts of an epoxy resin (10) having an epoxy equivalent of 304 g / eq. In the obtained epoxy resin, part of R in the formula (1) is a bromine atom and the other is a hydrogen atom, n = 1.4, and the bromine content is 19
% By weight, 9 out of X calculated from epoxy equivalent
2% is a glycidyl group, the others are hydrogen atoms,
The dinuclear body content was 16.8% and the softening point was 63.8 ° C.

The obtained epoxy resins (9) to (10),
For comparison, an epoxy resin (35) was used in Examples 7-
8. A glass cloth laminate was prepared in the same manner as in Comparative Example 4, and the glass transition point and measling resistance were measured according to JIS C-6481. The results are shown in Table 5. In addition,
Numerical values in the column of formulation in the table indicate parts by weight.

[0047]

[Table 5] Table 5 Actual Examples Comparative Examples 9 10 5 Epoxy resin (9) 80 Epoxy resin (10) 80 Epoxy resin (35) 80 Epoxy equivalent (g / eq) 351 304 468 Epoxidation rate (%) 55 92 0 2 Nucleus content (%) 15.5 16.8 16.3 Softening point (℃) 68.1 63.8 76.0 Dicyandiamide 3.4 3.4 3.4 2MZ 0.08 0.08 0.08 Methyl ethyl ketone 20 20 20 Methyl cellosolve 21 21 21 Dimethylformamide 21 21 21 Glass transition point (℃) 165 179 131 Measling resistance ○ ○ ×

[0048]

The epoxy resin of the present invention gives a cured product having excellent heat resistance, toughness and water resistance as compared with the compound represented by the formula (2). That is, the epoxy resin of the present invention can provide a cured product having excellent heat resistance, toughness and water resistance, and has a wide range of applications such as molding materials, casting materials, laminating materials, paints, adhesives and resists. Extremely useful for

Claims (4)

[Claims] 1. A formula (1): (In the formula, n represents an average value and represents a positive number. Each R represents a hydrogen atom or a bromine atom, and each R may be the same or different from each other. Further, each X is a hydrogen atom. Alternatively, it represents a glycidyl group, and each X may be the same or different from each other, but 10% or more of X 95
% Or less is a glycidyl group. In the epoxy resin represented by), when (A) R is all hydrogen atoms, the weight ratio of (a) binuclear compound is 0% or more and less than 4%, and the softening point is 80 ° C.
Or more and 90 ° C or less, or (b) the weight ratio of the binuclear body is 4%
Or more and less than 8%, and the softening point is 70 ° C. or more and less than 80 ° C., or (c) the weight ratio of the binuclear body is 8% or more and 1 or more.
When it is less than 2%, the softening point is 60 ° C. or more and less than 70 ° C., and (B) at least a part of R is a bromine atom, the bromine content is 15 to 30% by weight with respect to the entire resin. , (D) the weight ratio of the binuclear body is 0% or more and less than 9%,
And has a softening point of 80 ° C. or higher and 100 ° C. or lower, or
(E) An epoxy resin characterized in that the weight ratio of the binuclear body is 9% or more and less than 18% and the softening point is 60 ° C. or more and less than 80 ° C. 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 for a laminated board. 4. A cured product of the epoxy resin composition according to claim 2.