JP5885330B2 - Epoxy resin, epoxy resin composition, prepreg and cured products thereof - Google Patents

Description

  The present invention relates to a novel epoxy resin and epoxy resin composition. Moreover, it is related with hardened | cured materials, such as a prepreg formed with this epoxy resin composition.

  Epoxy resin compositions are generally cured products with excellent mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties, etc., such as adhesives, paints, laminates, molding materials, casting materials, etc. It is used in a wide range of fields. In recent years, cured products of epoxy resins used in these fields have begun to be highly purified and have various properties such as flame retardancy, heat resistance, moisture resistance, toughness, low linear expansion coefficient, and low dielectric constant characteristics. There is a need for improvement.

  In particular, in the electrical and electronic industry, which is a typical application of epoxy resin compositions, high-density mounting of semiconductors and high-density wiring of printed wiring boards have been promoted for the purpose of multi-function, high performance, and compactness. Although progress is being made, the heat generated from the inside of a semiconductor element or a printed wiring board increases with high-density mounting or high-density wiring, which may cause malfunction. Therefore, how to efficiently release generated heat to the outside is an important issue from the standpoint of energy efficiency and device design. These heat countermeasures include various measures such as using a metal core substrate, constructing a structure that easily dissipates heat at the design stage, and densely filling high thermal conductive filler in the polymer material (epoxy resin) to be used. Has been made. However, since the thermal conductivity of the polymer material acting as a binder that connects the high thermal conductivity sites is low, the thermal conduction speed of the polymer material becomes the rate-determining, and efficient heat dissipation is not possible at present.

  As a means for realizing high thermal conductivity of an epoxy resin, it is reported in Patent Document 1 that a mesogenic group is introduced into the structure. In the same document, as an epoxy resin having a mesogenic group, an epoxy resin having a biphenyl skeleton, etc. Is described. In addition, as an epoxy resin other than the biphenyl skeleton, a phenyl benzoate type epoxy resin is described. However, since the epoxy resin needs to be produced by an epoxidation reaction by oxidation, there are difficulties in safety and cost, and it is practical. It can not be said. Examples of using an epoxy resin having a biphenyl skeleton include Patent Documents 2 to 4, and among them, Patent Document 3 describes a technique in which an inorganic filler having high thermal conductivity is used in combination. However, the thermal conductivity of the cured product obtained by the methods described in these documents is not at a level that satisfies the market demand, and a cured product having higher thermal conductivity using an epoxy resin that is available at a relatively low cost. There is a need for an epoxy resin composition that provides.

  In addition, high heat conductive epoxy resins having a mesogenic group that have been reported so far have a very high melting point, making it difficult to take out the resinous form, and many of them have poor solvent solubility. Since such an epoxy resin begins to cure before being completely melted during curing, it is difficult to produce a uniform cured product, which is not preferable.

Japanese Unexamined Patent Publication No. 11-323162 Japanese Unexamined Patent Publication No. 2004-2573 Japanese Unexamined Patent Publication No. 2006-63315 Japanese Unexamined Patent Publication No. 2003-137971

  The present invention has been made as a result of studies to solve such problems, and provides an epoxy resin excellent in solvent solubility in which the cured product has high thermal conductivity.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, the present invention provides (1) the following formulas (1) to (5).

(In Formula (1), each R ₁ is independently present and is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a hydroxyl group, a nitro group, or an alkoxy having 1 to 10 carbon atoms. Represents one of the groups, l represents the number of R ₁ , and is an integer of 1 to 4)

(In Formula (2), each R ₂ is independently present, and is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkylcarbonyl group having 1 to 15 carbon atoms, or a carbon number. It represents any of 2-10 alkyl ester groups, C1-C10 alkoxy groups, morpholinylcarbonyl groups, phthalimide groups, piperonyl groups or hydroxyl groups.)

(In Formula (3), each R ₃ is independently present and is a hydrogen atom, an alkylcarbonyl group having 0 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a carbon number. Represents an alkyl ester group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or a hydroxyl group, n represents the number of carbon atoms, and represents an integer of 0, 1 or 2. m represents the number of R ₃ . And satisfies the relationship 1 ≦ m ≦ n + 2.)

(In Formula (4), R < ₁₂ > exists each independently and is any of a hydrogen atom, a C1-C20 alkyl group, a C6-C10 aryl group, a C1-C10 alkoxy group, or a hydroxyl group. Represents.)

(In Formula (5), R < ₁₃ > exists each independently, A hydrogen atom, a C1-C20 alkyl group, a C6-C10 aryl group, a C1-C10 alkoxy group, C1-C1 Represents an alkyl ester group of 10 to 10 or a hydroxyl group, and m is an integer of 1 to 10.)
One or more of the compounds represented by:
Following formula (6)

(In formula (6), each R ₄ is independently present and is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a hydroxyl group, a nitro group, a formyl group, an allyl group, or carbon. Any one of the alkoxy groups represented by formulas 1 to 10. k represents the number of R ₄ and is an integer of 1 to 4.) and a phenol compound obtained by reaction with the compound represented by , An epoxy resin obtained by reacting an epoxy resin obtained by reacting an epihalohydrin under conditions where the amount of the epoxy resin is excessive in an equivalent ratio,

(2) An epoxy resin composition comprising the epoxy resin and the curing agent according to (1) above,
(3) The epoxy resin composition according to item (2), which contains an inorganic filler having a thermal conductivity of 20 W / m · K or more,
(4) The epoxy resin composition according to (3), which is used for semiconductor sealing applications,
(5) A prepreg comprising the epoxy resin composition according to (4) and a sheet-like fiber base material,
(6) A cured product obtained by curing the epoxy resin composition according to item (4) or the prepreg according to item (5),
About.

  The epoxy resin of the present invention is useful when used in various composite materials such as semiconductor encapsulating materials and prepregs, adhesives, paints, etc., because the cured product is excellent in heat conduction. Moreover, since the epoxy resin of this invention has a low melting point compared with the epoxy resin which has a mesogenic group, and also is excellent in solvent solubility, it can give a uniform hardened | cured material.

The epoxy resin of the present invention is obtained by a reaction between an excess amount of the specific epoxy resin (A) and the following specific phenol compound (A) in molar ratio.
First, the phenol compound (A) will be described. The phenol compound (A) is obtained by a reaction between one or more compounds selected from the compounds represented by the following formulas (1) to (5) and a compound represented by the following formula (6).

(In the formula (1), _{R 1} is present independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a hydroxyl group, a nitro group, or 1 to 10 carbon atoms Represents one of alkoxy groups, and l represents the number of R ₁ and is an integer of 1 to 4.)
In the formula (1), the alkyl group, aryl group, and alkoxy group may have a substituent, and examples of the substituent include a methyl group, an ethyl group, and a propyl group.

In formula (1), each R ₁ is independently present, and is a hydrogen atom, an alkyl group having no substituent having 1 to 10 carbon atoms, an aryl group having no substituent having 6 to 10 carbon atoms, a hydroxyl group, or a nitro group. Or an alkoxy group having no substituent having 1 to 10 carbon atoms.

  Specific examples of the compound represented by the formula (1) include 2-hydroxyacetophenone, 3-hydroxyacetophenone, 4-hydroxyacetophenone, 2 ′, 4′-dihydroxyacetophenone, 2 ′, 5′-dihydroxyacetophenone, 3 ′. , 4′-dihydroxyacetophenone, 3 ′, 5′-dihydroxyacetophenone, 2 ′, 3 ′, 4′-trihydroxyacetophenone, 2 ′, 4 ′, 6′-trihydroxyacetophenone monohydrate, 4′-hydroxy -3′-methylacetophenone, 4′-hydroxy-2′-methylacetophenone, 2′-hydroxy-5′-methylacetophenone, 4′-hydroxy-3′-methoxyacetophenone, 2′-hydroxy-4′-methoxyacetophenone 4'-hydroxy-3'-nitroacetate Enone, 4′-hydroxy-3 ′, 5′-dimethoxyacetophenone, 4 ′, 6′-dimethoxy-2′-hydroxyacetophenone, 2′-hydroxy-3 ′, 4′-dimethoxyacetophenone, 2′-hydroxy-4 Examples include ', 5'-dimethoxyacetophenone, methyl 5-acetylsalicylate, and 2', 3'-dihydroxy-4'-methoxyacetophenone hydrate. Of these, 4'-hydroxy-3'-methoxyacetophenone, 4) -hydroxy-3'-methoxyacetophenone, because the solvent solubility when epoxidizing the resulting phenol compound is high and the cured product of the epoxy resin composition exhibits high thermal conductivity '-Hydroxyacetophenone is preferred.

(In Formula (2), each R ₂ is independently present, and is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkylcarbonyl group having 1 to 15 carbon atoms, or a carbon number. It represents any of 2-10 alkyl ester groups, C1-C10 alkoxy groups, morpholinylcarbonyl groups, phthalimide groups, piperonyl groups or hydroxyl groups.)

  In the formula (2), the aryl group, alkylcarbonyl group, alkyl ester group, and alkoxy group may have a substituent. Examples of the substituent include a carbonyl group, an ester group, an alkenyl group, a phenyl group, an alkoxy group, and an ether. It is preferably at least one selected from the group consisting of a group, a phthalimide group and a piperonyl group.

Specific examples of the compound represented by the formula (2) include acetone, 1,3-diphenyl-2-propanone, 2-butanone, 1-phenyl-1,3-butanedione, 2-pentanone, 3-pentanone, 4 -Methyl-2-pentanone, acetylacetone, 2-hexanone, 3-hexanone, isoamyl methyl ketone, ethyl isobutyl ketone, 4-methyl-2-hexanone, 2,5-hexanedione, 1,6-diphenyl-1,6- Hexanedione, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-4-heptanone, 5-methyl-3-heptanone, 6-methyl-2-heptanone, 2,6-dimethyl-4-heptanone, 2 -Octanone, 3-octanone, 4-octanone, 5-methyl-2-octanone, 2-nonanone, 3-nonanone, 4- Nanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5-decanone, 2-undecanone, 3-undecanone, 4-undecanone, 5-undecanone, 6-undecanone, 2-methyl-4-undecanone, 2-dodecanone, 3-dodecanone, 4-dodecanone, 5-dodecanone, 6-dodecanone, 2-tetradecanone, 3-tetradecanone, 8-pentadecanone, 10-nonadecanone, 7-tridecanone, 2-pentadecanone, 3-hexadecanone, 9- Heptadecanone, 11-heneicosanone, 12-tricosanone, 14-heptacosanone, 16-hentriacontanone, 18-pentatriacontanone, 4-ethoxy-2-butanone, 4- (4-methoxyphenyl) -2-butanone, 4 -Methoxy-4-methyl-2-pe Thanone, 4-methoxyphenylacetone, methoxyacetone, phenoxyacetone, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, isobutyl acetoacetate, sec-butyl acetoacetate, tert-butyl acetoacetate, 3-acetoacetic acid 3- Pentyl, amyl acetoacetate, isoamyl acetoacetate, hexyl acetoacetate, heptyl acetoacetate, n-octyl acetoacetate, benzyl acetoacetate, dimethyl succinate, dimethyl acetonylmalonate, diethyl acetonylmalonate, acetoacetate-2- Methoxyethyl, allyl acetoacetate, 4-sec-butoxy-2-butanone, benzyl butyl ketone, bisdemethoxycurcumin, 1,1-dimethoxy-3-butanone, 1,3-diacetoxyacetone, 4-hydroxy Cyphenylacetone, 4- (4-hydroxyphenyl) -2-butanone, isoamylmethylketone, 4-hydroxy-2-butanone, 5-hexen-2-one, acetonylacetone, 3,4-dimethoxyphenylacetone, Peronyl methyl ketone, piperonyl acetone, phthalimidoacetone, 4-isopropoxy-2-butanone, 4-isobutoxy-2-butanone, acetoxy-2-propanone, N-acetoacetylmorpholine, 1-acetyl-4-piperidone, Etc. Among these, acetone is preferable because solvent solubility when the obtained phenol compound is epoxidized is high and a cured product of the epoxy resin composition exhibits high thermal conductivity.

(In Formula (3), each R ₃ is independently present and is a hydrogen atom, an alkylcarbonyl group having 0 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a carbon number. Represents an alkyl ester group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or a hydroxyl group, n represents the number of carbon atoms, and represents an integer of 0, 1 or 2. m represents the number of R ₃ . And satisfies the relationship 1 ≦ m ≦ n + 2.)

In the formula (3), the case where R ₃ is an alkylcarbonyl group having 0 carbon atoms represents a carbonyl structure containing a carbon atom constituting the cycloalkane which is the main skeleton of the general formula (3), Examples thereof include 1,3-cyclopentanedione.
In the formula (3), the substituent is preferably an ether group or a carbonyl group.
In formula (3), the alkylcarbonyl group, alkyl group, aryl group, alkyl ester group, and alkoxy group may have a substituent, and examples of the substituent include a methyl group, an ethyl group, and a propyl group.

  Specific examples of the compound represented by the formula (3) include cyclopentanone, 3-phenylcyclopentanone, 2-acetylcyclopentanone, 1,3-cyclopentanedione, 2-methyl-1,3-cyclo Pentanedione, 2-ethyl-1,3-cyclopentanedione, cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 4-tert-butylcyclohexanone, 4-pentylcyclohexanone, 3-phenylcyclohexanone, 4 -Phenylcyclohexanone, 3,3-dimethylcyclohexanone, 3,4-dimethylcyclohexanone, 3,5-dimethylcyclohexanone, 4,4-dimethylcyclohexanone, 3,3,5-trimethylcyclohexanone, 2-acetylcyclohexano Ethyl 4-cyclohexanone carboxylate, 1,4-cyclohexanedione monoethylene ketal, bicyclohexane-4,4′-dione monoethylene ketal, 1,4-cyclohexanedione mono-2,2-dimethyltrimethylene ketal, 2- Acetyl-5,5-dimethyl-1,3-cyclohexanedione, 1,2-cyclohexanedione, 1,3-cyclohexanedione, 1,4-cyclohexanedione, 2-methyl-1,3-cyclohexanedione, 5-methyl -1,3-cyclohexanedione, dimedone, dimethyl 1,4-cyclohexanedione-2,5-dicarboxylate, 4,4′-bicyclohexanone, 2,2-bis (4-oxocyclohexyl) propane, cycloheptanone, Etc. Among these, cyclopentanone, cyclohexanone, cycloheptanone, 4- (2), because the solvent solubility when the obtained phenol compound is epoxidized is high and the cured product of the epoxy resin composition exhibits high thermal conductivity. Methylcyclohexanone is preferred.

(In Formula (4), R < ₁₂ > exists each independently and is a hydrogen atom, a C1-C20 alkyl group, a C6-C10 aryl group, a C1-C10 alkoxy group, or a hydroxyl group. Represents one of these.)

In formula (4), R ₁₂ is independently present, and is a hydrogen atom, an unsubstituted alkyl group having 1 to 20 carbon atoms, an unsubstituted aryl group having 6 to 10 carbon atoms, or an unsubstituted group having 1 to 10 carbon atoms. It is preferably an alkoxy group or a hydroxyl group.
In the formula (4), the alkyl group, aryl group, and alkoxy group may have a substituent, and examples of the substituent include a methyl group, an ethyl group, and a propyl group.

  Specific examples of the compound represented by the formula (4) include diacetyl, 2,3-pentanedione, 3,4-hexanedione, 5-methyl-2,3-hexanedione, 2,3-heptanedione, and the like. Is mentioned. Of these, diacetyl is preferred because of high solvent solubility when the resulting phenol compound is epoxidized and high thermal conductivity of the cured product of the epoxy resin composition.

(In Formula (5), R < ₁₃ > exists each independently, A hydrogen atom, a C1-C20 alkyl group, a C6-C10 aryl group, a C1-C10 alkoxy group, C1-C1 Represents an alkyl ester group of 10 to 10 or a hydroxyl group, and m is an integer of 1 to 10.)

In the formula (5), the alkyl group, aryl group, and alkoxy group may have a substituent, and examples of the substituent include a methyl group, an ethyl group, and a propyl group.
In formula (5), each R ₁₃ is independently present, and is a hydrogen atom, an alkyl group having no substituent having 1 to 20 carbon atoms, an aryl group having no substituent having 6 to 10 carbon atoms, or 1 to 1 carbon atoms. It is preferably an alkoxy group not having 10 substituents, an alkyl ester group having no substituent having 1 to 10 carbon atoms, or a hydroxyl group.

  Specific examples of the compound represented by the formula (5) include ethyl diacetoacetate, 2,5-hexanedione, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, 3- Examples include butyl-2,4-pentanedione, 3-phenyl-2,4-pentanedione, and ethyl 4-acetyl-5-oxohexanoate. Among these, since the solvent solubility at the time of epoxidizing the phenol compound obtained is high and the cured product of the epoxy resin composition exhibits high thermal conductivity, 3-methyl-2,4-pentanedione, 3 -Ethyl-2,4-pentanedione is preferred.

(In formula (6), each R ₄ is independently present and is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a hydroxyl group, a nitro group, a formyl group, an allyl group, or carbon. Represents one of the alkoxy groups of formula 1 to 10. k represents the number of R ₄ and is an integer of 1 to 4)
In the formula (6), the alkyl group, aryl group, and alkoxy group may have a substituent, and examples of the substituent include a methyl group, an ethyl group, and a propyl group.

  Specific examples of the compound represented by the formula (6) include 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 2,3-dihydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 2,5- Dihydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, syringaldehyde, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, isovanillin, 4-hydroxy-3-nitrobenzaldehyde, 5-hydroxy-2-nitrobenzaldehyde, 3 , 4-dihydroxy-5-nitrobenzaldehyde, vanillin, o-vanillin, 2-hydroxy-1-naphthaldehyde, 2-hydroxy-5-nitro-m-anisaldehyde, 2-hydroxy-5-methyli Sophthalaldehyde, 2-hydroxy-4-methoxybenzaldehyde, 1-hydroxy-2-naphthaldehyde, 2-hydroxy-5-methoxybenzaldehyde, 5-nitrovanillin, 5-allyl-3-methoxysalicylaldehyde, 3,5- Di-tert-butylsalicylaldehyde, 3-ethoxysalicylaldehyde, 4-hydroxyisophthalaldehyde, 4-hydroxy-3,5-dimethylbenzaldehyde, 2,4,6-trihydroxybenzaldehyde, 2,4,5-trihydroxybenzaldehyde 2,3,4-trihydroxybenzaldehyde, 3,4,5-trihydroxybenzaldehyde, 3-ethoxy-4-hydroxybenzaldehyde, and the like. These may use only 1 type or may use 2 or more types together. Among these, it is preferable to use vanillin alone, because the solvent solubility when the obtained phenol compound is epoxidized is high, and the cured product of the epoxy resin composition exhibits particularly high thermal conductivity.

The phenol compound (A) is obtained by an aldol condensation reaction between one or more of the compounds represented by the formulas (1) to (5) and the compound represented by the formula (6) under acidic conditions or basic conditions. .
The compound represented by the formula (6) is 1.0 to 1.05 mol, the formula (2), the formula (3), the formula (4) and the formula (1) with respect to 1 mol of the compound represented by the formula (1). 2.0-3.15 mol is used with respect to 1 mol of compounds represented by 5).

  When the aldol condensation reaction is performed under acidic conditions, examples of the acidic catalyst that can be used include inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid, and organic acids such as toluenesulfonic acid, xylenesulfonic acid, and oxalic acid. These may be used alone or in combination of a plurality of types. The usage-amount of an acidic catalyst is 0.01-1.0 mol with respect to 1 mol of compounds represented by Formula (6), Preferably it is 0.2-0.5 mol.

  On the other hand, when the aldol condensation reaction is performed under basic conditions, usable basic catalysts include metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as potassium carbonate and sodium carbonate, diethylamine, Examples include amine derivatives such as triethylamine, tributylamine, diisobutylamine, pyridine and piperidine, and amino alcohol derivatives such as dimethylaminoethyl alcohol and diethylaminoethyl alcohol. Also in the case of basic conditions, the basic catalysts listed above may be used alone, or a plurality of types may be used in combination. The usage-amount of a basic catalyst is 0.1-2.5 mol with respect to 1 mol of compounds represented by Formula (6), Preferably it is 0.2-2.0 mol.

  In the reaction for obtaining the phenol compound (A), a solvent may be used as necessary. The solvent that can be used is not particularly limited as long as it does not have reactivity with the compound represented by the formula (6) such as ketones, but the compound represented by the formula (6) as a raw material can be easily used. Alcohols are preferably used from the viewpoint of dissolution in the aqueous solution.

  The reaction temperature is usually 10 to 90 ° C, preferably 35 to 70 ° C. Although reaction time is 0.5 to 10 hours normally, since there is a difference in reactivity with the kind of raw material compound, it is not this limitation. When taking out as a resin after completion | finish of reaction, an unreacted substance, a solvent, etc. are removed from a reaction liquid under heating and pressure reduction, after washing | cleaning a reaction substance without water washing. When taking out with a crystal | crystallization, a crystal | crystallization is deposited by dripping a reaction liquid in a lot of water. When the reaction is carried out under basic conditions, the produced phenol compound (A) may be dissolved in water. Therefore, it is preferable to precipitate crystals as neutral to acidic conditions by adding hydrochloric acid or the like.

Next, the epoxy resin (A) will be described.
The epoxy resin (A) is obtained by reacting the phenol compound (A) obtained by the above method with epihalohydrin and epoxidizing it. In the case of epoxidation, only one type of phenol compound (A) may be used, or two or more types may be used in combination. Moreover, you may use together phenolic compounds other than a phenolic compound (A) with a phenolic compound (A).
As the phenolic compound other than the phenolic compound (A) that can be used in the above, any phenolic compound that is usually used as a raw material for epoxy resin can be used without particular limitation, but the present invention that the cured product has high thermal conductivity. Therefore, the combined use amount of other phenol compounds is preferably as small as possible, and it is particularly preferable to use only the phenol compound (A).
As the epoxy resin (A), a compound represented by the formula (6) and a compound represented by the formula (3) are obtained because they exhibit a particularly excellent solvent solubility and a cured product having high thermal conductivity. The epoxidized product of the phenol compound (A) obtained by the reaction with is preferable. Below, when it is set as a phenol compound, both the phenol compound (A) independent and the mixture with the other phenol compound used together with this are pointed out.

  In the reaction for obtaining the epoxy resin (A), epichlorohydrin, α-methylepichlorohydrin, β-methylepichlorohydrin, epibromohydrin, and the like can be used as the epihalohydrin, and epichlorohydrin which is easily available industrially is preferable. The usage-amount of epihalohydrin is 2-20 mol normally with respect to 1 mol of hydroxyl groups of a phenol compound (A), Preferably it is 2-15 mol, Most preferably, it is 2-6 mol. The epoxy resin (A) is obtained by a reaction in which a phenol compound and an epihalohydrin are added in the presence of an alkali metal oxide, and then the resulting 1,2-halohydrin ether group is closed and epoxidized. At this time, by using epihalohydrin in an amount significantly smaller than usual as described above, the molecular weight of the epoxy resin can be increased and the molecular weight distribution can be broadened. As a result, the resulting epoxy resin can be removed from the system as a resinous material having a relatively low softening point, and exhibits excellent solvent solubility.

Examples of the alkali metal hydroxide that can be used for the epoxidation reaction include sodium hydroxide, potassium hydroxide, and the like, and these may be used as they are, or an aqueous solution thereof may be used. When using an aqueous solution, the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system and separated from a mixture of water and epihalohydrin distilled continuously under reduced pressure or normal pressure. Alternatively, water may be removed and only the epihalohydrin is continuously returned to the reaction system. The amount of the alkali metal hydroxide used is usually 0.9 to 3.0 mol, preferably 1.0 to 2.5 mol, more preferably 1.0 to 2.0 mol per mol of the hydroxyl group of the phenol compound. Mol, particularly preferably 1.0 to 1.3 mol.
Further, the present inventors remarkably reduce the amount of halogen contained in the epoxy resin obtained by using flaky sodium hydroxide in the epoxidation reaction, rather than using sodium hydroxide as an aqueous solution. It came to know that it became possible. This halogen is derived from epihalohydrin, and the more it is mixed in the epoxy resin, the lower the thermal conductivity of the cured product. Further, the flaky sodium hydroxide is preferably added in portions in the reaction system. By performing the divided addition, it is possible to prevent a rapid decrease in the reaction temperature, thereby preventing the formation of impurities such as 1,3-halohydrin and halomethylene, and a cured product with higher thermal conductivity. Can be formed.

  In order to accelerate the epoxidation reaction, it is preferable to add a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride as a catalyst. The amount of the quaternary ammonium salt used is usually 0.1 to 15 g, preferably 0.2 to 10 g, per 1 mol of the hydroxyl group of the phenol compound.

  In addition, during the epoxidation, it is preferable for the reaction to proceed by adding an aprotic polar solvent such as alcohols such as methanol, ethanol and isopropyl alcohol, dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran and dioxane. Of these, alcohols or dimethyl sulfoxide are preferable. When alcohols are used, an epoxy resin can be obtained with a high yield. On the other hand, when dimethyl sulfoxide is used, the halogen content in the epoxy resin can be further reduced.

  When using the said alcohol, the usage-amount is 2-50 mass% normally with respect to the usage-amount of an epihalohydrin, Preferably it is 4-35 mass%. Moreover, when using an aprotic polar solvent, it is 5-100 mass% normally with respect to the usage-amount of epihalohydrin, Preferably it is 10-80 mass%.

The reaction temperature is usually 30 to 90 ° C, preferably 35 to 80 ° C. The reaction time is usually 0.5 to 10 hours, preferably 1 to 8 hours.
After completion of the reaction, the reaction product is washed with water or without washing with water, and the epihalohydrin, the solvent and the like are removed from the reaction solution under heating and reduced pressure. In order to further reduce the amount of halogen contained in the obtained epoxy resin, the recovered epoxy resin is dissolved in a solvent such as toluene or methyl isobutyl ketone, and an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is obtained. The reaction can be carried out by adding an aqueous solution of to ensure ring closure. In this case, the usage-amount of an alkali metal hydroxide is 0.01-0.3 mol normally with respect to 1 mol of hydroxyl groups of a phenol compound, Preferably it is 0.05-0.2 mol. 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 produced salt is removed by filtration, washing with water, etc., and the solvent is distilled off under heating and reduced pressure to obtain the epoxy resin (A). Moreover, when an epoxy resin (A) precipitates as a crystal | crystallization, after melt | dissolving the salt produced | generated in a lot of water, you may filter the crystal | crystallization of an epoxy resin (A).

Next, a method for obtaining the epoxy resin of the present invention by reacting the epoxy resin (A) obtained by the above method with the phenol compound (A) will be described.
The amount of the phenol compound (A) used is usually 0.1 to 0.8 mol, preferably 0.1 to 0.1 mol, based on 1 mol of the epoxy group of the epoxy resin (A). It is used so that it may become 7 mol, More preferably, it is 0.2-0.6 mol. If the amount of the phenol compound (A) is small, excellent solvent solubility cannot be imparted. Conversely, if the amount is too large, the high molecular weight increases, the softening point is high, the melt viscosity is increased, and workability is deteriorated.

  In the reaction for obtaining the epoxy resin of the present invention, a curing accelerator can be used. Specific examples of the curing accelerator include, but are not limited to, triphenylphosphine. The curing accelerator is used in an amount of usually 0.01 to 0.2 parts by mass, preferably 0.02 to 0.15 parts by mass with respect to 100 parts by mass of the epoxy resin (A).

  In the reaction for obtaining the epoxy resin of the present invention, a solvent may be used as necessary. There are no particular restrictions on the solvent that can be used. Speaking of solvents that easily dissolve both the epoxy resin (A) and the phenolic compound (A), ketones such as methyl ethyl ketone and methyl isobutyl ketone, cyclohexanone, cyclopentanone, etc. It is preferable to use an anone solvent as the solvent.

  The reaction temperature is usually 30 to 120 ° C, preferably 35 to 110 ° C. The reaction time is usually 0.5 to 15 hours, preferably 1 to 10 hours. After completion of the reaction, the epoxy resin of the present invention is obtained by removing the solvent and the like from the reaction solution under heating and reduced pressure after washing the reaction product with water or without washing with water.

  Hereinafter, the epoxy resin composition of the present invention will be described. The epoxy resin composition of the present invention contains the epoxy resin of the present invention as an essential component.

  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.

Specific examples of other epoxy resins include bisphenols (bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD, bisphenol I, etc.) and phenols (phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted) Naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene and dihydroxynaphthalene) and various aldehydes (formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.) Of polycondensates with benzene, aromatic compounds such as xylene and formaldehyde Polycondensates of compounds and phenols, phenols and various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene and isoprene Etc.), polycondensates of phenols and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.), phenols and aromatic dimethanols (benzene dimethanol, biphenyl dimethanol, etc.) Polycondensates, phenols and aromatic dichloromethyls (α, α'-dichloroxylene, bischloromethylbiphenyl etc.), phenols and aromatic bisalkoxymethyls Polycondensates with bismethoxymethylbenzene, bismethoxymethylbiphenyl, bisphenoxymethylbiphenyl, etc., polycondensates of bisphenols and various aldehydes, and glycidyl ether epoxy resins obtained by glycidylation of alcohols, alicyclic An epoxy resin, a glycidylamine-based epoxy resin, a glycidyl ester-based epoxy resin, and the like can be mentioned, but the epoxy resin is not limited to these as long as it is a commonly used epoxy resin. These may be used alone or in combination of two or more.
When other epoxy resins are used in combination, the proportion of the epoxy resin of the present invention in the total epoxy resin component in the epoxy resin composition of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, and 70% by mass. The above is more preferable, and 100% by mass (when no other epoxy resin is used in combination) is particularly preferable. However, when using the epoxy resin of this invention as a modifier of an epoxy resin composition, it adds in the ratio used as 1-30 mass% in all the epoxy resins. As the epoxy resin composition of the present invention, it is most preferable to use 100% by mass of the epoxy resin of the present invention as an epoxy resin.

The epoxy resin composition of the present invention contains a curing agent. Examples of the curing agent include amine compounds, acid anhydride compounds, amide compounds, and phenol compounds. Specific examples of these curing agents are shown in the following (a) to (e).
(A) Amine-based compounds Diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, naphthalenediamine, etc. (b) Acid anhydride-based compounds Phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride , Tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc. (c) Amide-based compounds Polyamide resin, etc.

(D) Phenol compound polyhydric phenols (bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, terpene diphenol, 4,4′-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 3,3 ′, 5, 5'-tetramethyl- (1,1'-biphenyl) -4,4'-diol, hydroquinone, resorcin, naphthalenediol, tris- (4-hydroxyphenyl) methane and 1,1,2,2-tetrakis (4 -Hydroxyphenyl) ethane and the like; phenols (eg, phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene and dihydroxynaphthalene) and aldehydes (formaldehyde, acetaldehyde, benzaldehyde, p-hydro) Phenol resins obtained by condensation with benzaldehyde, o-hydroxybenzaldehyde, furfural, etc.), ketones (p-hydroxyacetophenone, o-hydroxyacetophenone, etc.), or dienes (dicyclopentadiene, tricyclopentadiene, etc.); Phenols and substituted biphenyls (such as 4,4′-bis (chloromethyl) -1,1′-biphenyl and 4,4′-bis (methoxymethyl) -1,1′-biphenyl), or substituted phenyls ( Phenol resins obtained by polycondensation with 1,4-bis (chloromethyl) benzene, 1,4-bis (methoxymethyl) benzene, 1,4-bis (hydroxymethyl) benzene and the like; Or a modified product of the phenol resin; Lumpur A and halogenated phenols such as brominated phenol resin (e) Other imidazoles, BF ₃ ^- amine complex, guanidine derivatives

Among these other curing agents, active hydrogen such as amine compounds such as diaminodiphenylmethane, diaminodiphenylsulfone and naphthalenediamine, and condensates of catechol with aldehydes, ketones, dienes, substituted biphenyls or substituted phenyls. A curing agent having a structure in which groups are adjacent is preferable because it contributes to the arrangement of the epoxy resin.
A hardening | curing agent may be used independently and may use multiple. 0.5-2.0 equivalent is preferable with respect to 1 equivalent of epoxy groups of all epoxy resins, and, as for the usage-amount of all the hardening | curing agents, 0.6-1.5 equivalent is especially preferable.

The epoxy resin composition of the present invention can impart further excellent high heat conductivity to the cured product by containing an inorganic filler excellent in heat conduction as required.
The inorganic filler contained in the epoxy resin composition of the present invention is added for the purpose of imparting higher thermal conductivity to the cured product of the epoxy resin composition, and the thermal conductivity of the inorganic filler itself is too low. In some cases, the high thermal conductivity obtained by the combination of the epoxy resin and the curing agent may be impaired. Therefore, as the inorganic filler contained in the epoxy resin composition of the present invention, the one having higher thermal conductivity is preferable, usually 20 W / m · K or more, preferably 30 W / m · K or more, more preferably 50 W / m. -There is no restriction as long as it has a thermal conductivity of K or higher.
In addition, heat conductivity here is the value measured by the method based on ASTM E1530. Specific examples of inorganic fillers having such characteristics include inorganic powder fillers such as boron nitride, aluminum nitride, silicon nitride, silicon carbide, titanium nitride, zinc oxide, tungsten carbide, alumina, magnesium oxide, synthetic fibers, Examples thereof include fibrous fillers such as ceramic fibers, and coloring agents. The shape of these inorganic fillers may be any of powder (bulk shape, spherical shape), single fiber, long fiber, etc. However, in particular, if it is a flat plate, the cured product is cured by the lamination effect of the inorganic filler itself. This is preferable because the thermal conductivity becomes higher and the heat dissipation of the cured product is further improved.
Although the usage-amount of the inorganic filler in the epoxy resin composition of this invention is 2-1000 mass parts normally with respect to 100 mass parts of resin components in an epoxy resin composition, in order to raise heat conductivity as much as possible. It is preferable to increase the amount of the inorganic filler as much as possible as long as the handling of the epoxy resin composition of the present invention in a specific application is not hindered. These inorganic fillers may be used alone or in combination of two or more.

  In addition, if the thermal conductivity of the entire filler can be maintained at 20 W / m · K or more, the thermal conductivity of the inorganic filler with 20 W / m · K or more is less than 20 W / m · K. However, for the purpose of the present invention to obtain a cured product having as high a thermal conductivity as possible, the use of a filler having a thermal conductivity of less than 20 W / m · K is minimal. Should be kept on. There is no particular limitation on the type and shape of the filler that can be used in combination.

  When the epoxy resin composition of the present invention is used for semiconductor sealing applications, heat conduction is performed at a ratio of 75 to 93% by mass in the epoxy resin composition in terms of heat resistance, moisture resistance, mechanical properties, etc. of the cured product. It is preferable to use an inorganic filler having a rate of 20 W / m · K or more. In this case, the balance is an epoxy resin component, a curing agent component, and other additives that are added as necessary. Examples of the additive include other inorganic fillers that can be used in combination and a curing accelerator that will be described later.

  The epoxy resin composition of the present invention may contain a curing accelerator. Examples of the curing accelerator that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole and 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, triethylenediamine, Tertiary amines such as triethanolamine and 1,8-diazabicyclo (5,4,0) undecene-7, organic phosphines such as triphenylphosphine, diphenylphosphine and tributylphosphine, metal compounds such as tin octylate, Tetrasubstituted phosphonium tetrasubstituted borates such as tetraphenylphosphonium tetraphenylborate and tetraphenylphosphonium ethyltriphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate and N Such as tetraphenyl boron salts such methylmorpholine tetraphenylborate and the like. 0.01-15 mass parts is used for a hardening accelerator as needed with respect to 100 mass parts of epoxy resins.

  If necessary, various compounding agents such as a silane coupling agent, a release agent and a pigment, various thermosetting resins, various thermoplastic resins, and the like can be added to the epoxy resin composition of the present invention. Specific examples of thermosetting resins and thermoplastic resins include vinyl ester resins, unsaturated polyester resins, maleimide resins, cyanate resins, isocyanate compounds, benzoxazine compounds, vinyl benzyl ether compounds, polybutadiene and its modified products, and acrylonitrile. Examples include modified polymers, indene resins, fluororesins, silicone resins, polyetherimides, polyethersulfones, polyphenylene ethers, polyacetals, polystyrenes, polyethylenes, and dicyclopentadiene resins. The thermosetting resin or thermoplastic resin is used in an amount occupying 60% by mass or less in the epoxy resin composition of the present invention.

The epoxy resin composition of the present invention can be obtained by uniformly mixing the above-mentioned components, and preferred applications thereof include semiconductor encapsulants and printed wiring boards.
The epoxy resin composition of the present invention can be easily made into a cured product by the same method as conventionally known. For example, an epoxy resin that is an essential component of the epoxy resin composition of the present invention, a curing agent, an inorganic filler having a thermal conductivity of 20 W / m · K or more, and a curing accelerator, a compounding agent, and various thermosetting resins as necessary. And various thermoplastic resins, etc., if necessary, using an extruder, kneader or roll, etc., until the mixture is sufficiently mixed until uniform, the melt casting method or transfer molding A cured product of the epoxy resin composition of the present invention can be obtained by molding by a method, an injection molding method, a compression molding method, or the like, and further heating for 2 to 10 hours above the melting point. By sealing the semiconductor element mounted on the lead frame or the like by the above-described method, the epoxy resin composition of the present invention can be used for semiconductor sealing applications.

Moreover, the epoxy resin composition of this invention can also be made into the varnish containing a solvent. The varnish includes, for example, at least one of the epoxy resin of the present invention or the phenol resin of the present invention in at least one of an epoxy resin and a curing agent, and if necessary, has a thermal conductivity of 20 W / m · K or more. Mixtures containing other components such as inorganic fillers, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, N, N′-dimethylformamide, N, N′-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether Glycol ethers such as Tell, ethyl acetate, butyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, propylene glycol monomethyl ether acetate, dialkyl glutarate, dialkyl succinate, dialkyl adipate, It can be obtained by mixing with a cyclic ester such as γ-butyrolactone, an organic solvent such as petroleum ether such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha. The amount of the solvent is usually 10 to 95% by mass, preferably 15 to 85% by mass with respect to the whole varnish.
The varnish obtained as described above is impregnated into a fiber substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber and paper, and then the solvent is removed by heating, and the epoxy resin composition of the present invention By making a semi-cured state, the prepreg of the present invention can be obtained. Here, the “semi-cured state” means a state in which an epoxy group which is a reactive functional group partially remains unreacted. The prepreg can be hot press molded to obtain a cured product.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. In the synthesis examples, examples, and comparative examples, “part” means “part by mass”.
The epoxy equivalent, melting point, softening point, total chlorine content, and thermal conductivity were measured under the following conditions.
-Epoxy equivalent Measured by the method described in JIS K-7236, the unit is g / eq. It is.
Melting point Seiko Instruments Inc. EXSTAR6000 made
Measurement sample 2 mg to 5 mg Temperature rising rate 10 ° C./min.
-Softening point It measures by the method based on JISK-7234, and a unit is (degreeC).
-Thermal conductivity It measures by the method based on ASTM E1530, and a unit is W / m * K.

Synthesis example 1
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 136 parts of 4′-hydroxyacetophenone, 152 parts of vanillin and 200 parts of ethanol and dissolved. After adding 20 parts of 97 mass% sulfuric acid to this, it heated up to 60 degreeC, and after reacting at this temperature for 10 hours, the reaction liquid was inject | poured into 1200 parts of water, and was crystallized. The crystals were separated by filtration, washed twice with 600 parts of water, and then vacuum-dried to obtain 256 parts of phenol compound 1 as yellow crystals. The endothermic peak temperature of the obtained crystal as measured by DSC was 233 ° C.

Synthesis example 2
In a flask equipped with a stirrer, a reflux condenser, and a stirrer, 166 parts of 4′-hydroxy-3′-methoxyacetophenone, 122 parts of 4-hydroxybenzaldehyde, and 200 parts of ethanol were charged and dissolved. After adding 20 parts of 97% sulfuric acid thereto, the temperature was raised to 50 ° C., and after reacting at this temperature for 10 hours, the reaction solution was poured into 1200 parts of water for crystallization. The crystals were separated by filtration, washed twice with 600 parts of water, and then vacuum-dried to obtain 285 parts of phenol compound 2 as brown crystals. The endothermic peak temperature of the obtained crystal as measured by DSC was 193 ° C.

Synthesis example 3
In a flask equipped with a stirrer, a reflux condenser, and a stirrer, 56 parts of 4-methylcyclohexanone, 152 parts of vanillin and 150 parts of ethanol were charged and dissolved. After adding 10 parts of 97 mass% sulfuric acid, the temperature was raised to 50 ° C., and after reacting at this temperature for 10 hours, 25 parts of sodium tripolyphosphate was added and stirred for 30 minutes. Thereafter, 500 parts of methyl isobutyl ketone was added, followed by washing twice with 200 parts of water, and then the solvent was distilled off with an evaporator to obtain 304 parts of semi-solid phenol compound 3.
Synthesis example 4
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 29 parts of acetone, 152 parts of vanillin and 300 parts of ethanol and dissolved. To this was added 80 parts of a 50% aqueous sodium hydroxide solution, the temperature was raised to 45 ° C., and the reaction was carried out at this temperature for 120 hours. The crystals were separated by filtration, washed twice with 600 parts of water, and then vacuum-dried to obtain 165 parts of phenol compound 4 as yellow crystals. The melting point of the obtained crystal was 201 ° C. by DSC measurement.

Synthesis example 5
While purging a flask equipped with a stirrer, a reflux condenser, and a stirrer with nitrogen purge, 135 parts of the phenol compound 1 obtained in Synthesis Example 1, 370 parts of epichlorohydrin, and 93 parts of dimethyl sulfoxide (hereinafter, DMSO) were added, Under stirring, the temperature was raised to 70 ° C., and the mixture was dissolved. After 41 parts of flaky sodium hydroxide were added in portions over 90 minutes, the reaction was allowed to proceed at 70 ° C. for 2.5 hours. After completion of the reaction, excess solvent such as epichlorohydrin was distilled off under reduced pressure at 135 ° C. using a rotary evaporator. The residue was dissolved in 440 parts of methyl isobutyl ketone (hereinafter referred to as MIBK) and then washed with water to remove the salt. After washing with water, the MIBK solution was heated to 70 ° C., and 11 parts of a 30% aqueous sodium hydroxide solution was added with stirring. After reacting for 1 hour, washing was carried out until the washing water became neutral. 200 parts of epoxy resin 1 was obtained by distilling MIBK etc. off under reduced pressure at 180 degreeC using the rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 240 g / eq. The softening point was 56 ° C.

Synthesis Example 6
While purging a flask equipped with a stirrer, a reflux condenser, and a stirrer with nitrogen purge, 135 parts of the phenol compound 2 obtained in Synthesis Example 2, 370 parts of epichlorohydrin, and 93 parts of dimethyl sulfoxide (hereinafter, DMSO) were added. Under stirring, the temperature was raised to 70 ° C., and the mixture was dissolved. After 41 parts of flaky sodium hydroxide were added in portions over 90 minutes, the reaction was allowed to proceed at 70 ° C. for 2.5 hours. After completion of the reaction, excess solvent such as epichlorohydrin was distilled off under reduced pressure at 135 ° C. using a rotary evaporator. The residue was dissolved in 440 parts of MIBK and then washed with water to remove the salt. After washing with water, the MIBK solution was heated to 70 ° C., and 11 parts of a 30% aqueous sodium hydroxide solution was added with stirring. After reacting for 1 hour, washing was carried out until the washing water became neutral. 201 parts of epoxy resin 2 was obtained by distilling MIBK etc. off under reduced pressure at 180 degreeC using the rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 243 g / eq. The softening point was 60 ° C.

Synthesis example 7
While purging a flask equipped with a stirrer, a reflux condenser, and a stirrer with nitrogen purge, 190 parts of the phenol compound 3 obtained in Synthesis Example 3, 370 parts of epichlorohydrin, and 93 parts of dimethyl sulfoxide (hereinafter, DMSO) were added. Under stirring, the temperature was raised to 70 ° C., and the mixture was dissolved. After 41 parts of flaky sodium hydroxide were added in portions over 90 minutes, the reaction was allowed to proceed at 70 ° C. for 2.5 hours. After completion of the reaction, excess solvent such as epichlorohydrin was distilled off under reduced pressure at 135 ° C. using a rotary evaporator. The residue was dissolved in 492 parts of MIBK and then washed with water to remove the salt. After washing with water, the MIBK solution was heated to 70 ° C., and 11 parts of a 30% aqueous sodium hydroxide solution was added with stirring. After reacting for 1 hour, washing was carried out until the washing water became neutral. 224 parts of epoxy resin 3 was obtained by distilling MIBK etc. off under reduced pressure at 180 degreeC using the rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 270 g / eq. The softening point was 62 ° C.

Synthesis Example 8
While purging a flask equipped with a stirrer, a reflux condenser, and a stirrer with nitrogen purge, 163 parts of the phenol compound 4 obtained in Synthesis Example 4, 370 parts of epichlorohydrin, 93 parts of dimethyl sulfoxide (hereinafter, DMSO) were added, Under stirring, the temperature was raised to 70 ° C., and the mixture was dissolved. After 41 parts of flaky sodium hydroxide were added in portions over 90 minutes, the reaction was allowed to proceed at 70 ° C. for 2.5 hours. After completion of the reaction, excess solvent such as epichlorohydrin was distilled off under reduced pressure at 135 ° C. using a rotary evaporator. The residue was dissolved in 438 parts of MIBK and then washed with water to remove the salt. After washing with water, the MIBK solution was heated to 70 ° C., and 11 parts of a 30% aqueous sodium hydroxide solution was added with stirring. After reacting for 1 hour, washing was carried out until the washing water became neutral. 200 parts of epoxy resin 4 was obtained by distilling MIBK etc. off under reduced pressure at 180 degreeC using the rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 240 g / eq. The softening point was 52 ° C.

Example 1
Epoxy resin 1 obtained in Synthesis Example 5 while purging nitrogen in a flask equipped with a stirrer, a reflux condenser, and a stirrer
200 parts, 68 parts of the phenolic compound 1 obtained in Synthesis Example 1 and 200 parts of MIBK were added, and the mixture was heated to 80 ° C. with stirring and dissolved. After adding 0.2 part of triphenylphosphine, the temperature was raised to 100 ° C. The reaction was carried out for 8 hours at 100 ° C. After the reaction, 268 parts of epoxy resin 5 was obtained by distilling off MIBK and the like under reduced pressure at 180 ° C. using a rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 540 g / eq. The softening point was 87 ° C.

Example 2
Epoxy resin 2 obtained in Synthesis Example 6 while purging nitrogen in a flask equipped with a stirrer, a reflux condenser, and a stirrer
201 parts, 68 parts of phenol compound 2 obtained in Synthesis Example 2 and 200 parts of MIBK were added, and the mixture was heated to 80 ° C. and dissolved with stirring. After adding 0.2 part of triphenylphosphine, the temperature was raised to 100 ° C. The reaction was carried out for 6 hours at 100 ° C. After the reaction, 269 parts of epoxy resin 6 was obtained by distilling off MIBK and the like under reduced pressure at 180 ° C. using a rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 542 g / eq. The softening point was 89 ° C.

Example 3
Epoxy resin 3 obtained in Synthesis Example 7 while purging nitrogen with a stirrer, reflux condenser, and flask equipped with a stirrer
235 parts, 93 parts of phenolic compound 3 obtained in Synthesis Example 3 and 235 parts of MIBK were added, and the mixture was heated to 80 ° C. with stirring and dissolved. After adding 0.2 part of triphenylphosphine, the temperature was raised to 100 ° C. The reaction was carried out for 6 hours at 100 ° C. After the reaction, 328 parts of epoxy resin 7 was obtained by distilling off MIBK and the like under reduced pressure at 180 ° C. using a rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 667 g / eq. The softening point was 97 ° C.

Example 4
Epoxy resin 4 obtained in Synthesis Example 8 while purging nitrogen with a stirrer, reflux condenser, and flask equipped with a stirrer.
220 parts, 82 parts of phenolic compound 4 obtained in Synthesis Example 4 and 220 parts of MIBK were added, and the mixture was heated to 80 ° C. and dissolved with stirring. After adding 0.2 part of triphenylphosphine, the temperature was raised to 100 ° C. The reaction was carried out for 6 hours at 100 ° C. After the reaction, 302 parts of epoxy resin 8 was obtained by distilling off MIBK and the like under reduced pressure at 180 ° C. using a rotary evaporator. The epoxy equivalent of the obtained epoxy resin was 610 g / eq. The softening point was 88 ° C.

Example 5
Epoxy resin 1 obtained in Synthesis Example 5 while purging nitrogen in a flask equipped with a stirrer, a reflux condenser, and a stirrer
200 parts, 68 parts of phenolic compound 2 obtained in Synthesis Example 2 and 200 parts of MIBK were added, and the mixture was heated to 80 ° C. with stirring and dissolved. After adding 0.2 part of triphenylphosphine, the temperature was raised to 100 ° C. The reaction was carried out for 8 hours at 100 ° C. After the reaction, 268 parts of epoxy resin 9 was obtained by distilling off MIBK and the like under reduced pressure at 180 ° C. using a rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 542 g / eq. The softening point was 82 ° C.

Example 6
Epoxy resin 1 obtained in Synthesis Example 5 while purging nitrogen in a flask equipped with a stirrer, a reflux condenser, and a stirrer
200 parts, 92 parts of the phenol compound 3 obtained in Synthesis Example 3 and 200 parts of MIBK were added, and the mixture was heated to 80 ° C. with stirring and dissolved. After adding 0.2 part of triphenylphosphine, the temperature was raised to 100 ° C. The reaction was carried out for 8 hours at 100 ° C. After the reaction, 292 parts of epoxy resin 10 was obtained by distilling off MIBK and the like under reduced pressure at 180 ° C. using a rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 600 g / eq. The softening point was 93 ° C.

Example 7
Epoxy resin 1 obtained in Synthesis Example 5 while purging nitrogen in a flask equipped with a stirrer, a reflux condenser, and a stirrer
200 parts, 82 parts of phenolic compound 4 obtained in Synthesis Example 4 and 200 parts of MIBK were added, and the mixture was heated to 80 ° C. with stirring and dissolved. After adding 0.2 parts of triphenylphosphine, the temperature was raised to 100 ° C. The reaction was carried out for 8 hours at 100 ° C. After the reaction, 282 parts of epoxy resin 11 was obtained by distilling off MIBK and the like under reduced pressure at 180 ° C. using a rotary evaporator. The epoxy equivalent of the obtained epoxy resin is 570 g / eq. The softening point was 52 ° C.

  Table 1 shows the solubility of various epoxy resins including epoxy resins 5 to 11 obtained by these operations at 60 ° C. and 100 ° C. with respect to MIBK at a resin concentration of 30%.

  Epoxy resin 12: Epoxy resin represented by the following formula (7) (trade name: NC-3000, Nippon Kayaku Epoxy equivalent 276 g / eq.)

  Epoxy resin 13: a biphenyl type epoxy resin containing an equimolar amount of an epoxy resin represented by the following formulas (8) and (9) (trade name: YL-6121H manufactured by Japan Epoxy Resin, epoxy equivalent of 175 g / eq.)

Examples 8 to 14 and Comparative Examples 1 and 2
Various components are blended in the proportions (parts) shown in Table 2, kneaded with mixing rolls, tableted, prepared by resin molding by transfer molding, heated at 160 ° C. for 2 hours, and further heated at 180 ° C. for 8 hours. Hardened | cured material of the epoxy resin composition of invention and the resin composition for a comparison was obtained. The results of measuring the thermal conductivity of these cured products are shown in Table 2.

Curing agent 1: Phenol novolak represented by the following formula (10) (trade name: H-1, hydroxyl group equivalent 105 g / eq. Manufactured by Meiwa Kasei)

  Curing accelerator: Triphenylphosphine (manufactured by Hokuko Chemical)

Examples 15 to 21 and Comparative Examples 3 and 4
Various components are blended in the proportions (parts) shown in Table 3, kneaded with a mixing roll, converted into a tablet, a resin molded product is prepared by transfer molding, heated at 160 ° C. for 2 hours, and further heated at 180 ° C. for 8 hours. Hardened | cured material of the epoxy resin composition of invention and the resin composition for a comparison was obtained. The results of measuring the thermal conductivity of these cured products are shown in Table 3.

Inorganic filler 1: spherical alumina (trade name: DAW-100, manufactured by Denki Kagaku Kogyo Co., Ltd., thermal conductivity 38 W / m · K)
Inorganic filler 2: Boron nitride (trade name: SGP, manufactured by Denki Kagaku Kogyo Co., Ltd., thermal conductivity 60 W / m · K)

Example 22
100 parts of the epoxy resin 5 obtained in Example 1 was dissolved in 1000 parts of dimethylformamide at 70 ° C. and then returned to room temperature. In 48 parts of dimethylformamide, 7 parts of 1,5-naphthalenediamine (manufactured by Tokyo Chemical Industry Co., Ltd., amine equivalent: 40 g / eq.) As a curing agent was dissolved at 70 ° C. and then returned to room temperature. The above epoxy resin solution and the curing agent solution are mixed and stirred with a stirring blade type homomixer to make a uniform varnish, and further an inorganic filler (trade name: SGP, manufactured by Denki Kagaku Kogyo Co., Ltd., thermal conductivity 60 W / m · K) 204 parts (50 parts by volume with respect to 100 parts by volume of resin solids) and 100 parts of dimethylformamide were added and mixed and stirred to prepare the epoxy resin composition of the present invention.
The varnish of this epoxy resin composition was impregnated into a 0.2 mm thick glass fiber woven fabric (trade name: 7628 / AS890AW, manufactured by Asahi Schwer) and dried by heating to obtain a prepreg. After the four prepregs and the copper foils arranged on both sides thereof were superposed, they were integrated by heating and pressing for 90 minutes under the conditions of a temperature of 175 ° C. and a pressure of 4 MPa to obtain a laminate having a thickness of 0.8 mm. The thermal conductivity of the laminate was measured and found to be 4.3 W / m · K.

Example 23
Epoxy resin 5 in Example 22 was changed to epoxy resin 7
A laminate was obtained by the same operation procedure as in Example 22 except that 100 parts, the amount of 1,5-naphthalenediamine was changed to 6 parts, and the amount of inorganic filler was changed to 201 parts. The heat conductivity of this laminate was measured and found to be 4.5 W / m · K.

Comparative Example 5
Example 22 except that epoxy resin 5 in Example 22 was changed to 100 parts of epoxy resin 13 (YL-6121H), the amount of 1,5-naphthalenediamine was changed to 23 parts, and the amount of inorganic filler was changed to 234 parts. A laminate was obtained by the same operation procedure as in No. 22. The heat conductivity of this laminate was measured and found to be 3.6 W / m · K.

  From the above results, it was confirmed that the epoxy resin of the present invention was excellent in solvent solubility, and the cured product of the epoxy resin composition containing the epoxy resin of the present invention had excellent thermal conductivity. Therefore, the epoxy resin of the present invention is extremely useful when used for insulating materials for electric / electronic parts, laminated boards (printed wiring boards, etc.) and the like.

  The cured product of the epoxy resin composition of the present invention has excellent thermal conductivity and superior solvent solubility as compared with a cured product of a conventional epoxy resin. Therefore, it is extremely useful for a wide range of applications such as an electric / electronic material, a molding material, a casting material, a laminated material, a paint, an adhesive, a resist, and an optical material as a sealing material and a prepreg.

Claims (6)

Obtained by reacting one or more compounds represented by the following formulas (1) to (3) with a compound represented by formula (6) and an epihalohydrin to the phenol compound. An epoxy resin obtained by reacting an epoxy resin with an amount in which the amount of the epoxy resin is excessive in an equivalent ratio, wherein the epoxy equivalent is 540 g / eq. That is the epoxy resin.
(In Formula (1), each R ₁ is independently present and is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a hydroxyl group, a nitro group, or an alkoxy having 1 to 10 carbon atoms. Represents one of the groups, l represents the number of R ₁ and is an integer of 1 to 4)
(In the formula (2), _{R 2} is present independently represent a hydrogen atom, an alkyl group of 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkylcarbonyl group 2-15 carbon atoms, carbon atoms It represents any of 2-10 alkyl ester groups, C1-C10 alkoxy groups, morpholinylcarbonyl groups, phthalimide groups, piperonyl groups or hydroxyl groups.)
(In Formula (3), each R ₃ is independently present, and is a hydrogen atom, an alkylcarbonyl group having 2 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a carbon number. Represents an alkyl ester group having 2 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or a hydroxyl group, n represents the number of carbon atoms, and represents an integer of 0, 1 or 2. m represents the number of R ₃ . And satisfies the relationship 1 ≦ m ≦ n + 2.)
(In formula (6), each R ₆ is independently present and is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a hydroxyl group, a nitro group, a formyl group, an allyl group, or carbon. Represents any one of the alkoxy groups of formula 1 to 10. k represents the number of R ₆ and is an integer of 1 to 4)   An epoxy resin composition comprising the epoxy resin according to claim 1 and a curing agent.   The epoxy resin composition according to claim 2, comprising an inorganic filler having a thermal conductivity of 20 W / m · K or more.   The epoxy resin composition according to claim 3, which is used for semiconductor sealing applications.   A prepreg comprising the epoxy resin composition according to claim 4 and a sheet-like fiber base material. Hardened | cured material formed by hardening | curing the epoxy resin composition of Claim 4, or the prepreg of Claim 5.