JP2008019449A - Method of preparing epoxy resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of preparing an epoxy resin composition useful as a plastics raw material; a thermosetting resin material; an antioxidant; a component for an electric/electronic part insulating material, an adhesive, a paint, and a molding material; and an intermediate for various industrial uses. <P>SOLUTION: The method of preparing an epoxy resin composition comprises the steps of: condensation polymerizing, under an existence of a basic catalyst, one or more types of phenols selected from the group consisting of a cresol, a xylenol, a trimethylphenol, 2-tert-butyl-5-methyl-phenol, 2-tert-butyl-4-methylphenol, an octylphenol, a phenylphenol, a diphenylphenol, 2,3,6-trimethylphenol, guaiacol, hydroquinone, a resorcin, a catechol, a naphthol, a dihydroxynaphthalene, a methyl naphthol, and an allylphenol, and a compound represented by Formula 4 (wherein X is an oxygen atom or a sulfur atom, plural Qs are each an hydrogen atom or 1-5C alkyl group, and j is an integer of 1 to 3), to prepare a phenolic compound; and reacting the phenolic compound with an epihalohydrin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention is used for insulating materials for electrical and electronic parts including those for highly reliable semiconductor sealing, and for various composite materials including laminated boards (printed wiring boards) and CFRP (carbon fiber reinforced plastics), adhesives, The present invention relates to a method for producing an epoxy resin useful for paints and the like.

Epoxy resins are widely used in the fields of electrical and electronic parts, structural materials, adhesives, paints, etc. due to their workability and excellent electrical properties, heat resistance, adhesion, moisture resistance (water resistance), etc. Yes.

However, in recent years, especially in the electric and electronic fields, further improvements in various properties of the resin such as high purity, moisture resistance, adhesion, and low viscosity for high filler filling are required. Yes. In addition, as a structural material, a lightweight material with excellent mechanical properties is required for aerospace materials and leisure / sports equipment applications. In response to these requirements, many proposals have been made for epoxy resins and resin compositions containing them, but they are still not sufficient.

The present invention provides an insulating material for electrical and electronic parts (such as a highly reliable semiconductor encapsulating material) and a laminate (print) that exhibit excellent low viscosity, moisture resistance (water resistance), impact resistance, and adhesion in the cured product. The present invention provides a method for producing an epoxy resin useful for various composite materials including wiring boards and the like, CFRP, adhesives, paints, and the like.

（式中、Ｘは酸素原子または硫黄原子を示す。複数存在するＱは独立して水素原子または炭素数１〜５のアルキル基を示す。ｊは１〜３の整数を示す）で表される化合物を塩基性触媒の存在下に縮重合し、フェノール性化合物を調製し、これとエピハロヒドリン類を反応させることを特徴とするエポキシ樹脂の製造方法
（２）フェノール類が２，６キシレノール、２，５−キシレノール、２，３，６−トリメチルフェノール、２−ｔｅｒｔブチル−５−メチルフェノールから選ばれる１種以上である上記（１）記載のエポキシ樹脂の製造方法
に関する。 The inventors of the present invention have completed the present invention as a result of intensive studies on methods for imparting the above properties to epoxy resins, epoxy resin compositions and cured products thereof. That is, the present invention comprises (1) cresol, xylenol (dimethylphenol), trimethylphenol, 2-tertbutyl-5-methylphenol, 2-tertbutyl-4-methylphenol, octylphenol, phenylphenol, diphenylphenol, 2, One or more phenols selected from 3,6-trimethylphenol, guaiacol, hydroquinone, resorcin, catechol, naphthol, dihydroxynaphthalene, methylnaphthol, and allylphenol, and the following formula (4)

(In the formula, X represents an oxygen atom or a sulfur atom. A plurality of Qs independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. J represents an integer of 1 to 3). A method for producing an epoxy resin characterized in that a compound is subjected to polycondensation in the presence of a basic catalyst to prepare a phenolic compound and this is reacted with an epihalohydrin. (2) The phenol is 2,6 xylenol, 2, It is related with the manufacturing method of the epoxy resin of the said (1) description which is 1 or more types chosen from 5-xylenol, 2,3,6-trimethylphenol, and 2-tertbutyl-5-methylphenol.

Since the epoxy resin composition containing the epoxy resin obtained by the production method of the present invention has excellent moisture resistance (water resistance), impact resistance and adhesion in the cured product, it is an insulating material for electrical and electronic parts (high reliability) It is extremely useful when used for various composite materials including adhesive semiconductor sealing materials, laminated boards (printed wiring boards, etc.) and CFRP, adhesives, paints, and the like. In particular, when used as a semiconductor encapsulant, it has excellent solder crack resistance.

The production method of the present invention comprises a specific phenol and the following (4):

(In the formula, X represents an oxygen atom or a sulfur atom. A plurality of Qs independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. J represents an integer of 1 to 3). A phenolic compound obtained by condensation polymerization of the compound in the presence of a basic catalyst and, if necessary, a solvent is reacted with an epihalohydrin.

Examples of the compound of the formula (4) include furfural, 3-furaldehyde, 3-methylfurfural, 5-methylfurfural, 5-ethylfurfural, 2-thiophenecarboxaldehyde, 3-thiophenecarboxaldehyde, 3-methyl-2-thiophene. Carboxaldehyde etc. are mentioned, However, It is not limited to these, You may use individually or in combination of 2 or more types.

Examples of phenols include cresol, xylenol (dimethylphenol), trimethylphenol, 2-tertbutyl-5-methylphenol, 2-tertbutyl-4-methylphenol, octylphenol, phenylphenol, diphenylphenol, 2,3,6- One or more selected from trimethylphenol, guaiacol, hydroquinone, resorcin, catechol, naphthol, dihydroxynaphthalene, methylnaphthol, and allylphenol are used.
The usage-amount of phenol is 1.5-20 times mole normally with respect to 1 mol of compounds of Formula (4), Preferably it is 1.8-10 times mole.

Examples of the solvent include methanol, ethanol, propanol, isopropanol, toluene, xylene and the like. However, the solvent is not limited to these and may be used alone or in combination of two or more. When a solvent is used, the amount used is usually 5 to 500 parts by weight, preferably 10 to 300 parts by weight, per 100 parts by weight of phenols.

A basic compound is used as the catalyst. Moreover, although there is a method using an organometallic compound, it is disadvantageous in terms of cost. Specific examples of the basic catalyst include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide, sodium methoxide, sodium Alkali metal alkoxides such as ethoxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, and alkaline earth metal alkoxides such as magnesium methoxide and magnesium ethoxide are exemplified, but not limited thereto. These may be used alone or in combination of two or more. The usage-amount of a catalyst is 0.005-2.0 times mole normally with respect to 1 mol of phenols, Preferably it is 0.01-1.1 times mole.

The reaction is carried out by adding a basic catalyst to a mixture of the compound of formula (4), phenols and (optionally a solvent) and heating. Moreover, you may add the compound of Formula (4) gradually to the place which is heating the mixture of phenols and a catalyst (a solvent if needed). The reaction time is 5 to 100 hours, and the reaction temperature is usually 50 to 150 ° C. After completion of the reaction, neutralization is performed, and then the phenolic compound is obtained by removing unreacted raw materials and solvents under filtration or heating under reduced pressure.

Epihalohydrins used for the epoxidation reaction of phenolic compounds include epichlorohydrin, epibromhydrin, epiiodohydrin, β-methylepichlorohydrin, β-methylepibromhydrin, β-ethylepichlorohydrin, and the like. Epichlorohydrin that is industrially easily available and inexpensive is preferred. This reaction can be performed according to a conventionally known method.

For example, it is made to react at 20-120 degreeC for 1 to 20 hours, adding alkali metal hydroxide solids, such as sodium hydroxide and potassium hydroxide, to the mixture of a phenolic compound and epihalohydrins collectively or gradually. At this time, the alkali metal hydroxide may be used in the form of an aqueous solution. In that case, the alkali metal hydroxide is continuously added and water and epihalohydrins are continuously added under reduced pressure or normal pressure from within the reaction system. The water may be removed and the epihalohydrins may be continuously returned to the reaction system.

In said method, the usage-amount of epihalohydrins is 0.5-20 mol normally with respect to 1 equivalent of hydroxyl groups of a phenolic compound, Preferably it is 0.7-10 mol. The usage-amount of an alkali metal hydroxide is 0.5-1.5 mol normally with respect to 1 equivalent of hydroxyl groups of a phenolic compound, Preferably it is 0.7-1.2 mol. In addition, an epoxy resin having a low hydrolyzable halogen concentration is obtained by adding an aprotic polar solvent such as dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, 1,3-dimethyl-2-imidazolidinone in the above reaction, Suitable for use as an electronic material sealing material. The amount of the aprotic polar solvent used is usually 5 to 200% by weight, preferably 10 to 100% by weight, based on the weight of the epihalohydrin. In addition to the above solvent, the reaction can easily proceed by adding alcohols such as methanol and ethanol. In addition, toluene, xylene, dioxane and the like can also be used.

Moreover, quaternary ammonium salts such as tetramethylammonium chloride, tetramethylammonium bromide, and trimethylbenzylammonium chloride are used as a catalyst in a mixture of a phenolic compound and an excess of epihalohydrin, and the reaction is performed at 50 to 150 ° C. for 1 to 20 hours. A halohydrin ether of a phenolic compound obtained by the reaction is added with a solid or aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide and reacted at 20 to 120 ° C. for 1 to 20 hours to react with the halohydride. The epoxy resin of the present invention can also be obtained by ring closure of a phosphorus ether. In this case, the amount of the quaternary ammonium salt used is usually 0.001 to 0.2 mol, preferably 0.05 to 0.1 mol, relative to 1 equivalent of the hydroxyl group of the phenolic compound.

Usually, these reactants are washed with water, or after removing excess epihalohydrin under heating and decompression without washing with water, and then dissolved in a solvent such as toluene, xylene, methyl isobutyl ketone, and the like, and then an alkali such as sodium hydroxide or potassium hydroxide. The reaction is carried out again by adding an aqueous solution of metal hydroxide. In this case, the amount of the alkali metal hydroxide used is usually 0.01 to 0.2 mol, preferably 0.05 to 0.1 mol, relative to 1 equivalent of the hydroxyl group of the phenolic compound. The reaction temperature is usually 50 to 120 ° C., and the reaction time is usually 0.5 to 2 hours.

After completion of the reaction, the by-produced salt is removed by filtration, washing with water, etc., and an epoxy resin with less hydrolyzable halogen can be obtained by distilling off a solvent such as toluene, xylene, methyl isobutyl ketone under heating and reduced pressure.

Moreover, the synthesis | combination process of a phenolic compound and the process of epoxidation can also be performed continuously. For example, after reacting the compound of formula (4) with phenols by the above-described method, neutralization, filtration, distillation under heating under reduced pressure, etc., without removing unreacted raw materials and solvents, The epihalohydrins are directly added, epoxidized by the above-mentioned method, and the epoxidized material of the unreacted raw material is distilled off together with the solvent at the final solvent distillation stage.

The epoxy resin thus obtained (hereinafter referred to as the epoxy resin of the present invention) can be mixed with a curing agent and used as an epoxy resin composition (hereinafter referred to as the epoxy resin composition of the present invention). In the epoxy resin composition of the present invention, the epoxy resin of the present invention can be used alone or in combination with other epoxy resins. When used in combination, the proportion of the epoxy resin of the present invention in the total epoxy resin is preferably 20% by weight or more, particularly preferably 30% by weight or more.

Specific examples of epoxy resins that can be used in combination with the epoxy resin of the present invention include novolac type epoxy resins, trisphenol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and alicyclic epoxies. Resins, biphenol type epoxy resins, glycidyl amine epoxy resins, glycidyl ester epoxy resins and the like are exemplified, but not limited thereto. These may be used alone or in combination of two or more.

Specific examples of curing agents that can be used in the epoxy resin composition of the present invention include amine-based curing agents such as aliphatic polyamines, aromatic polyamines, and polyamide polyamines, and acid anhydrides such as hexahydrophthalic anhydride and methyltetrahydrophthalic anhydride. Physical curing agents, phenolic novolaks, trisphenolmethane, phenolic / dicyclopentadiene polymer, phenolic / xylylene glycols polycondensates, phenolic / biphenyldimethanols polycondensates, Examples thereof include, but are not limited to, Lewis acids such as boron trifluoride or salts thereof, dicyandiamides, and the like. These may be used alone or in combination of two or more.

In the epoxy resin composition of the present invention, the amount of the curing agent used is preferably 0.5 to 1.5 equivalents, particularly preferably 0.6 to 1.2 equivalents, relative to 1 equivalent of the epoxy group of the epoxy resin.

The epoxy resin composition of the present invention contains a curing accelerator as necessary. Specific examples of the curing accelerator that can be used include imidazole compounds such as 2-methylimidazole and 2-ethylimidazole, tertiary amine compounds such as tris- (dimethylaminomethyl) phenol, triphenylphosphine, trioctylphosphine, Known curing accelerators include phosphine compounds such as tricyclohexylphosphine, triphenylphosphine / triphenylborane, tetraphenylphosphonium / tetraphenylborate, and boron trifluoride, but are not particularly limited to these. Absent. If necessary, the curing accelerator is used in an amount of 0.01 to 15 parts by weight based on 100 parts by weight of the epoxy resin.

The epoxy resin composition of the present invention may further contain additives that are usually used as necessary. Specific examples of additives that can be used include polybutadiene and modified products thereof, modified products of acrylonitrile copolymer, polyphenylene ether, polystyrene, polyethylene, polyimide, fluororesin, maleimide compounds, cyanate ester compounds, silicone gel, and silicone oil. As well as silica, alumina, calcium carbonate, quartz powder, aluminum powder, graphite, talc, clay, iron oxide, titanium oxide, aluminum nitride, asbestos, mica, glass powder, glass fiber, glass nonwoven fabric or carbon fiber, etc. Coloring agents such as materials, surface treatment agents for fillers such as silane coupling agents, mold release agents, carbon black, phthalocyanine blue, and phthalocyanine green.

The epoxy resin composition of the present invention is obtained by uniformly mixing the above components at a predetermined ratio, and is usually precured at 130 to 180 ° C. for 30 to 500 seconds, and further at 150 to 250 ° C. A sufficient curing reaction proceeds by post-curing for 15 hours, and a cured product is obtained. Alternatively, the components of the epoxy resin composition can be uniformly dispersed or dissolved in a solvent or the like, and the solvent can be removed and then cured.

The cured product thus obtained has high heat resistance, moisture resistance, and high adhesion. Therefore, the epoxy resin of the present invention can be used in a wide range of fields where heat resistance, moisture resistance and adhesion are required. Specifically, it is useful as a blending component for all electric / electronic materials such as insulating materials, laminates, and sealing materials. In addition to molding materials and composite materials, they can also be used in fields such as paint materials and adhesives.

Hereinafter, the present invention will be described in more detail with reference to production examples and examples. The present invention is not limited to these examples. In the examples, epoxy equivalent, melt viscosity, softening point, and hydrolyzable chlorine concentration were measured under the following conditions.
1) Epoxy equivalent: Measured by a method according to JIS K-7236.
2) Melt viscosity: Melt viscosity measuring machine in cone plate method at 150 ° C: Corn plate (ICI) high temperature viscometer (manufactured by RESEARCH EQUIPMENT (LONDON) LTD.)
Corn No. ; 3 (measuring range 0-20 poise)
Sample amount: 0.15 ± 0.005 (g)
3) Softening point: measured by a method according to JIS K-7234 4) Hydrolyzable chlorine concentration: 1N-KOH ethanol solution was added to the sample dioxane solution and refluxed for 30 minutes. Value measured by the method and divided by the weight of the sample

Example 1
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 244 parts by weight of 2,6-xylenol, 122 parts by weight of methanol, and 7 parts by weight of sodium hydroxide, stirred and dissolved, and then heated to reflux. By the way, 96 parts by weight of furfural was dropped in 2 hours. Thereafter, the mixture was reacted at reflux temperature for 15 hours, neutralized with 140 parts by weight of a 20% aqueous sodium dihydrogen phosphate solution, and 500 parts by weight of water was added. Next, the precipitated crystals were collected by filtration, washed with a methanol: water = 1: 1 solution, and then dried in a vacuum dryer. As a result, 304 parts by weight of 4,4 ′-(2-furyl-methylene) bis [2,6-dimethylphenol] (polycondensate (P1)) was obtained. Melting point: 147 ° C.
To 161 parts by weight of the resulting polycondensate (P1), 500 parts by weight of epichlorohydrin (ECH, the same shall apply hereinafter) and 100 parts by weight of dimethyl sulfoxide (DMSO, the same shall apply hereinafter) are charged into a reaction vessel, heated, stirred and dissolved, While maintaining the temperature at 45 ° C., the reaction system was kept at 45 Torr, and 100 parts by weight of 40 wt% aqueous sodium hydroxide solution was continuously added dropwise over 4 hours. At this time, ECH and water distilled off by azeotropic distillation were cooled and separated, and then the reaction was carried out while returning only the organic layer ECH into the reaction system. After completion of dropping of the aqueous sodium hydroxide solution, the reaction was further carried out at 45 ° C. for 3 hours and at 70 ° C. for 30 minutes. Subsequently, washing with water was repeated to remove the by-product salt and dimethyl sulfoxide, and then excess epichlorohydrin was distilled off from the oil layer under heating and reduced pressure, and 500 parts by weight of methyl isobutyl ketone was added to the residue and dissolved. This methyl isobutyl ketone solution was heated to 70 ° C., 4 parts by weight of 30% aqueous sodium hydroxide solution was added and reacted for 1 hour, and then the reaction solution was washed with water until the washing solution became neutral. Then, methyl isobutyl ketone is distilled off from the oil layer under heating and reduced pressure to obtain the formula (5)

(In the formula, G represents a glycidyl group, and m = 0.03 (average value).) 210 parts by weight of the epoxy resin (E1) of the present invention represented by the following formula was obtained. Epoxy resin (E1) had an epoxy equivalent of 222 g / eq, a softening point of 45 ° C., a melt viscosity of 0.4 poise, and a hydrolyzable chlorine concentration of 370 ppm.

Example 2
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 328 parts by weight of 2-tertbutyl-5-methylphenol, 328 parts by weight of methanol, and 8 parts by weight of sodium hydroxide. 96 parts by weight of furfural was dropped into the refluxed state in 2 hours. Then, after reacting at reflux temperature for 35 hours, 240 parts by weight of methanol and 240 parts by weight of water were added, neutralized with 200 parts by weight of 35% aqueous hydrochloric acid solution, and the precipitated crystals were collected by filtration, and methanol: water = 2. After washing with a 1: 1 solution, it was further washed with methanol and dried in a vacuum dryer. As a result, 332 parts by weight of 4,4 ′-(2-furyl-methylene) bis [2-tertbutyl-5-methylphenol] (polycondensate (P2)) was obtained. Melting point: 236-237 ° C.
Example 1 except that 161 parts by weight of the polycondensate (P1) in Example 1 was changed to 203 parts by weight of the polycondensate (P2) obtained above, 650 parts by weight of ECH, and 120 parts by weight of DMSO. The same operation was performed. As a result, equation (6)

(In the formula, G represents a glycidyl group. M = 0.04 (average value).) 245 parts by weight of the epoxy resin (E2) of the present invention represented by the following formula was obtained. The epoxy equivalent of the epoxy resin (E2) was 270 g / eq, the softening point was 68 ° C., the melt viscosity was 0.4 poise, and the hydrolyzable chlorine concentration was 360 ppm.

Example 3
In Example 1, the same operation was carried out except that 244 parts by weight of 2,6-xylenol was changed to 244 parts by weight of 2,5-xylenol, and 4,4 ′-(2-furyl-methylene) bis [2 , 5-dimethylphenol] (polycondensate (P3)) 301 parts by weight were obtained. Melting point: 192 ° C.
The same operation as in Example 1 was performed except that 161 parts by weight of the polycondensate (P1) in Example 1 was changed to 161 parts by weight of the polycondensate (P3) obtained above. As a result, equation (8)

(In the formula, G represents a glycidyl group, and m = 0.08 (average value)). Thus, 221 parts by weight of the epoxy resin (E3) of the present invention represented by the following formula was obtained. Epoxy resin (E3) had an epoxy equivalent of 232 g / eq, a softening point of 66 ° C., a melt viscosity of 0.5 poise, and a hydrolyzable chlorine concentration of 380 ppm.

Example 4
In Example 1, the same operation was performed except that 244 parts by weight of 2,6-xylenol was changed to 272 parts by weight of 2,3,6-trimethylphenol and sodium hydroxide was changed to 5 parts by weight of lithium hydroxide. 298 parts by weight of 4,4 ′-(2-furyl-methylene) bis [2,3,5-trimethylphenol] (polycondensate (P4)) was obtained. Melting point: 176 ° C.
The same operation as in Example 1 was performed except that 161 parts by weight of the polycondensate (P1) in Example 1 was changed to 175 parts by weight of the polycondensate (P4) obtained above. As a result, equation (9)

(In the formula, G represents a glycidyl group, and m = 0.03 (average value)). Thus, 219 parts by weight of the epoxy resin (E4) of the present invention was obtained. The epoxy equivalent of the epoxy resin (E4) was 238 g / eq, the softening point was 68 ° C., the melt viscosity was 1.0 poise, and the hydrolyzable chlorine concentration was 370 ppm.

Example 5
In Example 1, the same operation was performed except that sodium hydroxide was changed to 5 parts by weight of lithium hydroxide, furfural was changed to 112 parts by weight of 2-thiophenecarboxaldehyde, and the reaction time was changed to 25 hours. 307 parts by weight of '-(2-thienyl-methylene) bis [2,6-dimethylphenol] (polycondensate (P5)) was obtained. Melting point: 167 ° C.
The same operation as in Example 1 was performed except that 161 parts by weight of the polycondensate (P1) in Example 1 was changed to 169 parts by weight of the polycondensate (P5) obtained above. As a result, the formula (10)

(In the formula, G represents a glycidyl group, and m = 0.04 (average value).) 216 parts by weight of the epoxy resin (E5) of the present invention represented by the following formula was obtained. Epoxy resin (E5) had an epoxy equivalent of 233 g / eq, a softening point of 50 ° C., a melt viscosity of 0.4 poise, and a hydrolyzable chlorine concentration of 400 ppm.

Example 6
In Example 5, the same operation was performed except that 244 parts by weight of 2,6-xylenol was changed to 244 parts by weight of 2,5-xylenol and the reaction time was changed to 30 hours, and 4,4 ′-(2- 284 parts by weight of thienyl-methylene) bis [2,5-dimethylphenol] (polycondensate (P6)) were obtained. Melting point: 216 ° C.
The same operation as in Example 1 was performed except that 161 parts by weight of the polycondensate (P1) in Example 1 was changed to 169 parts by weight of the polycondensate (P6) obtained above. As a result, the formula (11)

(In the formula, G represents a glycidyl group, and m = 0.07 (average value)). 214 parts by weight of the epoxy resin (E6) of the present invention represented by the following formula was obtained. Epoxy resin (E6) had an epoxy equivalent of 239 g / eq, a softening point of 71 ° C., a melt viscosity of 0.6 poise, and a hydrolyzable chlorine concentration of 390 ppm.

Example 7
In Example 5, the same operation was carried out except that 244 parts by weight of 2,6-xylenol was changed to 272 parts by weight of 2,3,6-trimethylphenol and the reaction time was changed to 60 hours. 284 parts by weight of (2-thienyl-methylene) bis [2,3,5-trimethylphenol] (polycondensate (P7)) was obtained. Melting point: 163 ° C.
The same operation as in Example 1 was performed except that 161 parts by weight of the polycondensate (P1) in Example 1 was changed to 183 parts by weight of the polycondensate (P7) obtained above. As a result, equation (12)

(Wherein G represents a glycidyl group, and m = 0.04 (average value)). 214 parts by weight of the epoxy resin (E7) according to the present invention was obtained. The epoxy equivalent of the epoxy resin (E7) was 248 g / eq, the softening point was 74 ° C., the melt viscosity was 1.4 poise, and the hydrolyzable chlorine concentration was 410 ppm.

Examples 8-14
The epoxy resins (E1) to (E7) obtained in Examples 1 to 7 were used, and a curing agent (phenol novolak resin (Nippon Kayaku Co., Ltd., PN-80, 150) was used for 1 epoxy equivalent of epoxy resin. Melt viscosity at 1.5 ° C., softening point of 86 ° C., hydroxyl group equivalent of 106 g / eq), 1 hydroxyl group equivalent, and further 1 part by weight of curing accelerator (triphenylphosphine) per 100 parts by weight of epoxy resin. A resin molded body was prepared by molding and cured at 160 ° C. for 2 hours and further at 180 ° C. for 8 hours.

The results of measuring the physical properties of the cured product thus obtained are shown in Tables 1 and 2. The physical property values were measured by the following methods.
(A) Water absorption rate: Rate of weight increase (%) after boiling a disk-shaped test piece having a diameter of 5 cm and a thickness of 4 mm in water at 100 ° C. for 24 hours.
(B) Copper foil peel strength: 180 ° peel test measurement temperature; 30 ° C. tensile speed; 200 mm / min copper foil; Nikko Gould Co., Ltd. JTC foil 70 μm
(C) Izod impact test: Measured according to JIS K7110.

Claims (2)

Cresol, xylenol, trimethylphenol, 2-tertbutyl-5-methylphenol, 2-tertbutyl-4-methylphenol, octylphenol, phenylphenol, diphenylphenol, 2,3,6-trimethylphenol, guaiacol, hydroquinone, resorcin, One or more phenols selected from catechol, naphthol, dihydroxynaphthalene, methylnaphthol, and allylphenol, and the following formula (4)

(In the formula, X represents an oxygen atom or a sulfur atom. A plurality of Qs independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. J represents an integer of 1 to 3). A method for producing an epoxy resin, comprising subjecting a compound to polycondensation in the presence of a basic catalyst, preparing a phenolic compound, and reacting this with an epihalohydrin. 2. The method for producing an epoxy resin according to claim 1, wherein the phenol is one or more selected from 2,6 xylenol, 2,5-xylenol, 2,3,6-trimethylphenol, and 2-tertbutyl-5-methylphenol. .