WO2022209642A1

WO2022209642A1 - Epoxy resin and production method therefor, curable resin composition, and cured product thereof

Info

Publication number: WO2022209642A1
Application number: PCT/JP2022/010112
Authority: WO
Inventors: 隆行遠島
Original assignee: 日本化薬株式会社
Priority date: 2021-03-30
Filing date: 2022-03-08
Publication date: 2022-10-06
Also published as: CN116670199A; TW202237572A; JP2022154013A; KR20230161416A; JP7132385B1

Abstract

The present invention provides an epoxy resin and an epoxy resin composition, cured products of which have excellent low water absorption and high elasticity.　This epoxy resin is represented by formula (1). (In formula (1), n is the number of repetitions and the average thereof is 1<n<20. R represents a substituent represented by formula (2). Each p represents a real number of 0 to 4, and the average value of p is 0.5 to 1.5.) (In formula (2), * represents the portion bonded to an aromatic ring in formula (1). X represents a hydrogen atom or a hydrocarbon group having 1-6 carbon atoms. q represents a real number of 0 to 5.)

Description

Epoxy resin, method for producing the same, curable resin composition, and cured product thereof

The present invention relates to an epoxy resin having a specific structure, a curable resin composition, and a cured product thereof.

Epoxy resin is excellent in electrical properties (dielectric constant/dielectric loss tangent, insulating properties), mechanical properties, adhesive properties, and thermal properties (heat resistance, etc.). It is widely used in the fields of electrical and electronic materials, structural materials, adhesives, and paints.

In recent years, in the electrical and electronic fields, performance improvements such as flame retardancy, moisture resistance, adhesion, and dielectric properties of resin compositions, high purity, low viscosity for high filling of fillers (inorganic or organic fillers) There is a demand for further improvement in various properties such as improved reactivity in order to shorten the molding cycle (Patent Document 1). In addition, as structural materials, lightweight materials with excellent mechanical properties are required for use in aerospace materials, leisure and sports equipment, and the like. Especially in the field of semiconductor encapsulation, substrates (substrates themselves or their peripheral materials) have become more complicated with thinning, stacking, systematization, and three-dimensionalization in accordance with the transition of semiconductors. Required properties such as heat resistance and high fluidity are required.

Examples of applications of epoxy resins in structural materials include CFRP (Carbon Fiber Reinforced Plastics). CFRP is used as a matrix resin for aircraft applications, taking advantage of the characteristics that the molded product is lightweight and has high strength.
Materials such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and tetraglycidyldiaminodiphenylmethane are generally used as resins for matrix resins such as CFRP. In aircraft applications, glycidylamine type epoxy resins such as tetraglycidyldiaminodiphenylmethane are used.

In recent years, the required properties for CFRP have become more stringent, and high heat resistance is required when it is applied to structural materials for aerospace applications and vehicles (Patent Document 2). Glycidylamine-based materials have high heat resistance, but have a high water absorption rate, and have the problem of deterioration in properties after water absorption. On the other hand, although general glycidyl ether type epoxy resins have relatively low water absorption, there is a problem that their elastic moduli are low. Therefore, materials with high heat resistance, high elastic modulus, and low water absorption are desired.

JP 2015-147854 A WO2010/204173

In view of the above problems, an object of the present invention is to provide an epoxy resin and an epoxy resin composition whose cured product is excellent in low water absorption and high elasticity.

The present inventors have completed the present invention as a result of intensive research to solve the above problems. That is, the present invention relates to the following [1] to [7]. In the present application, "(numerical value 1) to (numerical value 2)" indicate that upper and lower limits are included.
[1]
An epoxy resin represented by the following formula (1).

(In formula (1), n is the number of repetitions, the average value of which is 1<n<20. R represents a substituent represented by the following formula (2). p is a real number of 0 to 4, respectively. and the average value of p is 0.5 to 1.5.)

(In Formula (2), * represents a bond to the aromatic ring of Formula (1). X represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. q represents a real number of 0 to 5. )

[2]
An epoxy resin represented by the following formula (3).

(In formula (3), n is the number of repetitions, and the average value is 1<n<20.)

[3]
The epoxy resin according to the preceding item [1] or [2], which has a weight average molecular weight of 400 to 3000 as determined by gel permeation chromatography (GPC).
[4]
A curable resin composition containing the epoxy resin according to any one of [1] to [3] above.
[5]
The curable resin composition according to the preceding item [4], further comprising an amine-based curing agent.
[6]
A cured product obtained by curing the curable resin composition according to [4] or [5] above.
[7]
Any one of the preceding items [1] to [3], including a step of reacting a polycondensate of a dicyclopentadiene-based compound and a phenol-based compound with an indene derivative to obtain a phenolic resin, and a step of epoxidizing the phenolic resin. A method for producing an epoxy resin according to claim 1.

The present invention relates to an epoxy resin having a specific structure, a curable resin composition, and a cured product thereof, which has low water absorption and high elasticity.
Therefore, the present invention can be applied to insulating materials for electric and electronic parts (such as highly reliable semiconductor sealing materials), laminated boards (printed wiring boards, build-up boards, etc.), various composite materials such as CFRP, adhesives, paints, etc. Useful.

1 shows a GPC chart of Synthesis Example 1. FIG. 1 shows a GPC chart of Example 1. FIG. 2 shows a GPC chart of Synthesis Example 2. FIG. 1 shows a GPC chart of Synthesis Example 3. FIG.

The present invention will be described in detail below.

The epoxy resin of the present invention is represented by the following formula (1).

In the above formula (1), the average value of n can be calculated from the number average molecular weight obtained by measurement by gel permeation chromatography (GPC, detector: RI), or from the area ratio of each of the separated peaks. . The average value of n is more preferably 1<n<10, and particularly preferably 1<n<5.

It is more preferable that the substituent R of the epoxy resin represented by the formula (1) is represented by the formula (2), and X is a hydrogen atom.

In the above formula (1), each p represents a real number of 0 to 4, the average value of p is preferably 0.5 to 2.0, more preferably 0.5 to 1.5, 0.8 to 1.2 is particularly preferred. When the average value of p is 0.5 or more, a high elastic modulus and low water absorbency are likely to be exhibited, and when it is 2.0 or less, a significant increase in viscosity and a significant decrease in heat resistance can be suppressed.

An example of a preferable structure of the epoxy resin represented by the formula (1) is an epoxy resin represented by the following formula (3).

The preferred range of n in the formula (3) is the same as in the formula (1).

Although the method for producing the epoxy resin of the present invention is not particularly limited, it can be obtained, for example, by subjecting the phenol resin represented by the following formula (4) and epihalohydrin to an addition or ring closure reaction in the presence of a solvent and a catalyst.

(In formula (4), n is the number of repetitions, and the average value is 1<n<20. R represents a substituent represented by the following formula (5). p is a real number of 0 to 4, respectively. and the average value of p is 0.5 to 1.5.)

(In formula (5), * represents a bond to the aromatic ring of formula (4). X represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. q represents a real number of 0 to 5. )

The preferred ranges of n, p, q, R, and X in the formulas (4) and (5) are the same as in the formulas (1) and (2).

Here, a method for producing the phenolic resin represented by the formula (4) will be described.
The method for producing the phenolic resin represented by the formula (4) is not particularly limited. For example, a dicyclopentadiene-type phenolic resin (polycondensation product of a dicyclopentadiene-based compound and a phenolic compound) is reacted with a benzylating agent such as indene or indanol in the presence of an acid catalyst to obtain the desired phenolic resin. be able to. Modification with indene and indene derivatives such as indanol improves the rigidity of the molecule compared to benzylic agents such as benzyl alcohol, so high elastic modulus and low water absorption can be achieved without significantly impairing heat resistance. is possible.

The acidic catalyst used in synthesizing the phenolic resin represented by the formula (4) includes hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, zinc chloride, ferric chloride, aluminum chloride, p-toluenesulfonic acid, methanesulfonic acid, Examples include activated clay and ion exchange resins. These may be used alone or in combination of two or more. The amount of the catalyst used is 0.1 to 50% by weight, preferably 1 to 30% by weight, based on the phenolic hydroxyl groups used. Become slow.

The reaction may be carried out using an organic solvent such as toluene or xylene, or without a solvent, if necessary. For example, after adding an acidic catalyst to a mixed solution of a phenolic resin and a benzylating agent obtained by polycondensation of a dicyclopentadiene compound and a phenolic compound, if the catalyst contains water, the water is azeotropically removed from the system. preferably excluded. Thereafter, while removing the solvent from the system, the temperature is raised to 100 to 220° C., preferably 120 to 180° C., and the reaction is carried out for 1 to 50 hours, preferably 2 to 20 hours. Since water is by-produced when an alcohol-based benzylating agent is used, it is removed from the system while azeotroping with the solvent when the temperature is raised. After the completion of the reaction, neutralize the acidic catalyst with an alkaline aqueous solution, etc., add a water-insoluble organic solvent to the oil layer, repeat washing with water until the wastewater becomes neutral, and then remove the solvent and excess benzylation agent under heating and reduced pressure. Remove. When activated clay or ion exchange resin is used, the reaction solution is filtered to remove the catalyst after completion of the reaction.

Next, a method for producing the epoxy resin of the present invention will be explained.
As described above, the method for producing the epoxy resin of the present invention is not particularly limited. can.
The amount of epihalohydrin to be used is generally 1.0 to 20.0 mol, preferably 1.5 to 10.0 mol, per 1 mol of phenolic hydroxyl group of the phenolic resin.

Alkali metal hydroxides that can be used in the epoxidation reaction include sodium hydroxide and potassium hydroxide. The alkali metal hydroxide may be solid or its aqueous solution may be used. When an aqueous solution is used, an aqueous solution of the alkali metal hydroxide is continuously added to the reaction system, and water and epihalohydrin are continuously distilled off under reduced pressure or normal pressure, and water is removed by liquid separation. Alternatively, epihalohydrin may be continuously returned to the reaction system. The amount of the alkali metal hydroxide to be used is generally 0.9 to 2.5 mol, preferably 0.95 to 1.5 mol, per 1 mol of the phenolic hydroxyl group of the phenolic resin. If the amount of alkali metal hydroxide used is too small, the reaction will not proceed sufficiently. On the other hand, excessive use of alkali metal hydroxide exceeding 2.5 mol per 1 mol of phenolic hydroxyl groups in the phenolic resin leads to unnecessary waste by-production.

A quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, or trimethylbenzylammonium chloride may be added as a catalyst to promote the above reaction. The amount of the quaternary ammonium salt to be used is usually 0.1 to 15 g, preferably 0.2 to 10 g, per 1 mol of the phenolic hydroxyl group of the phenolic resin. If the amount used is too small, a sufficient reaction acceleration effect cannot be obtained, and if the amount used is too large, the amount of quaternary ammonium salt remaining in the epoxy resin increases, which may cause deterioration in electrical reliability.

During the epoxidation reaction, it is preferable to add an alcohol such as methanol, ethanol and isopropyl alcohol, and an aprotic polar solvent such as dimethylsulfone, dimethylsulfoxide, tetrahydrofuran and dioxane to proceed with the reaction. When alcohols are used, the amount used is generally 2-50% by weight, preferably 4-20% by weight, based on the amount of epihalohydrin used. When an aprotic polar solvent is used, it is usually 5-100% by weight, preferably 10-80% by weight, based on the amount of epihalohydrin used. The reaction temperature is usually 30-90°C, preferably 35-80°C. The reaction time is usually 0.5 to 100 hours, preferably 1 to 30 hours.
After completion of the reaction, epihalohydrin, solvent, etc. are removed from the reactant by heating under reduced pressure after washing with water or without washing with water. In order to further reduce the hydrolyzable halogen content of the epoxy resin, the recovered epoxy resin is dissolved in a solvent such as toluene or methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added. can also be used to ensure ring closure. In this case, the alkali metal hydroxide is used in an amount of usually 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, per 1 mol of the phenolic hydroxyl group of the phenolic resin used for glycidylation. The reaction temperature is generally 50-120° C., and the reaction time is generally 0.5-24 hours. After completion of the reaction, the salt produced is removed by filtration, washing with water, etc., and the solvent is distilled off under heating and reduced pressure to obtain the epoxy resin of the present invention.

The epoxy resin of the present invention is usually in the form of a semi-solid to solid resin at room temperature, and its softening point is preferably 100°C or lower, more preferably 80°C or lower. If the softening point is higher than 100° C., the viscosity is high and the fiber impregnation property is lowered during prepreg preparation. Also, the epoxy equivalent is preferably 200 to 1000 g/eq, more preferably 300 to 800 g/eq, particularly preferably 300 to 700 g/eq, and most preferably 330 to 600 g/eq.

The epoxy resin composition of the present invention is described below.
In the epoxy resin composition of the present invention, the epoxy resin represented by Formula (1) can be used alone or in combination with other epoxy resins. When used in combination, the ratio of the epoxy resin represented by formula (1) to the total epoxy resin is preferably 10 to 98% by weight, more preferably 20 to 95% by weight, and still more preferably 30 to 95% by weight. %. By setting the amount to be added to 10% by weight or more, it is possible to improve the elastic modulus and exhibit low water absorption.

Specific examples of other epoxy resins that can be used in combination with the epoxy resin of the present invention include bisphenols (bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD, etc.) or phenols (phenol, alkyl-substituted phenol, aromatic-substituted Phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) and various aldehydes (formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, croton aldehyde, cinnamaldehyde, etc.); the above phenols and various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, disopropenylbiphenyl, butadiene, isoprene, etc.); polycondensation products of the phenols and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.); methanol, etc.); polycondensation products of the above phenols and aromatic dichloromethyls (α,α'-dichloroxylene, bischloromethylbiphenyl, etc.); the above phenols and aromatic bisalkoxymethyls ( bismethoxymethylbenzene, bismethoxymethylbiphenyl, bisphenoxymethylbiphenyl, etc.); polycondensates of the above bisphenols and various aldehydes; glycidyl ether-based epoxy resins obtained by glycidylating alcohols and the like; alicyclic epoxies Examples include resins, glycidylamine-based epoxy resins, glycidyl ester-based epoxy resins, and the like, but are not limited to these as long as they are commonly used epoxy resins. These may be used independently and may use 2 or more types.

Examples of curing agents that can be used in the epoxy resin composition of the present invention include amine-based curing agents, acid anhydride-based curing agents, amide-based curing agents, and phenol-based curing agents. Specific examples of usable curing agents include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 3,3′-diamino Diphenylsulfone, 2,2'-diaminodiphenylsulfone, diethyltoluenediamine, dimethylthiotoluenediamine, diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4' -diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetramethyldiphenylmethane, 4,4 '-diamino-3,3',5,5'-tetraethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetraisopropyldiphenylmethane, 4,4'-methylenebis(N-methylaniline) , bis(aminophenyl)fluorene, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 2,2′-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4- aminophenoxy)phenyl]sulfone, 1,3′-bis(4-aminophenoxy)benzene, 1,4′-bis(4-aminophenoxy)benzene, 1,4′-bis(4-aminophenoxy)biphenyl, 4 ,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, naphthalenediamine, benzidine, dimethylbenzidine, International Publication No. 2017/170551 Synthesis example 1 and aromatic amine compounds described in Synthesis Example 2, 1,3-bis(aminomethyl)cyclohexane, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), norbornanediamine, ethylenediamine, propane Aliphatic amines such as diamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, dimerdiamine, and triethylenetetramine are included, but are not limited thereto, and can be suitably used depending on the properties desired to be imparted to the composition. can. It is preferable to use an aromatic amine in order to secure a pot life, and it is preferable to use an aliphatic amine in order to impart quick curing. By using an amine-based compound containing a bifunctional component as a main component as a curing agent, a highly linear network can be constructed during the curing reaction, and particularly excellent toughness can be expressed. Also, amide compounds such as polyamide resin synthesized from dicyandiamide, dimer of linolenic acid and ethylenediamine; phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydro Acid anhydride compounds such as phthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride; bisphenols (bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD, etc.) or phenols ( Phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) and various aldehydes (formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphtho aldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.), or the above phenols and various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene , divinylbiphenyl, disopropenylbiphenyl, butadiene, isoprene, etc.); Polycondensates of aromatic dimethanols (benzenedimethanol, biphenyldimethanol, etc.), or polycondensations of the above phenols and aromatic dichloromethyls (α,α'-dichloroxylene, bischloromethylbiphenyl, etc.) or polycondensates of the above phenols and aromatic bisalkoxymethyls (bismethoxymethylbenzene, bismethoxymethylbiphenyl, bisphenoxymethylbiphenyl, etc.), or polycondensates of the above bisphenols and various aldehydes, and these phenolic compounds such as modified products of; imidazole, trifluoroborane-amine complexes, guanidine derivatives and the like, but are not limited thereto.

The amount of the curing agent used in the epoxy resin composition of the present invention 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. Good cured physical properties can be obtained by setting the equivalent weight to 0.5 to 1.5.

A curing accelerator may be used in combination when performing a curing reaction using the above curing agent. Curing accelerators that can be used include, for example, imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 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; Tetraphenylphosphonium/tetraphenylborate, tetrasubstituted phosphonium/tetrasubstituted borate such as tetraphenylphosphonium/ethyltriphenylborate, 2-ethyl-4-methylimidazole/tetraphenylborate, N-methylmorpholine/tetraphenylborate and the like. Carboxylic acid compounds such as phenyl boron salts, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthoic acid, and salicylic acid. A carboxylic acid compound such as salicylic acid is preferred from the viewpoint of promoting the curing reaction between the amine compound and the epoxy resin. 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.

Furthermore, an inorganic filler can be added to the epoxy resin composition of the present invention as necessary. Inorganic fillers include powders of crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, titania, talc, etc. Beads formed by spheroidizing are included, but are not limited to these. These may be used independently and may use 2 or more types. The amount of these inorganic fillers used varies depending on the application. From the aspect, it is preferably used in a proportion of 20% by weight or more in the epoxy resin composition, more preferably 30% by weight or more, and particularly 70 to 95% by weight in order to improve the coefficient of linear expansion with the lead frame. It is more preferable to use it in the ratio which occupies.

A release agent can be added to the epoxy resin composition of the present invention to improve release from the mold during molding. As the mold release agent, any of those conventionally known can be used. system waxes and the like. These may be used alone or in combination of two or more. The blending amount of these release agents is preferably 0.5 to 3% by weight based on the total organic components. If the amount is too small, the release from the mold will be poor, and if the amount is too large, adhesion to the lead frame or the like will be poor.

A coupling agent can be added to the epoxy resin composition of the present invention in order to increase the adhesion between the inorganic filler and the resin component. As the coupling agent, any of conventionally known ones can be used. Examples include various alkoxysilane compounds such as silane, alkoxytitanium compounds, and aluminum chelates. These may be used alone or in combination of two or more. The coupling agent may be added by first treating the surface of the inorganic filler with the coupling agent and then kneading it with the resin, or by mixing the coupling agent with the resin and then kneading the inorganic filler. .

Further, known additives can be added to the epoxy resin composition of the present invention as necessary. Specific examples of additives that can be used include polybutadiene and its modified products, modified acrylonitrile copolymers, polyphenylene ethers, polystyrene, polyethylene, polyimide, fluororesins, maleimide compounds, cyanate ester compounds, silicone gels, and silicone oils. and coloring agents such as carbon black, phthalocyanine blue and phthalocyanine green.

The epoxy resin composition of the present invention is obtained by uniformly mixing the above components. The epoxy resin composition of the present invention can be easily cured by a method similar to the conventionally known method. For example, an epoxy resin and a curing agent, and if necessary, a curing accelerator, an inorganic filler, a release agent, a silane coupling agent, and an additive are mixed until uniform using an extruder, a kneader, a roll, etc. The epoxy resin composition of the present invention is obtained by thorough mixing, which is molded by a melt casting method, transfer molding method, injection molding method, compression molding method, or the like, and further at 80 to 200° C. for 2 to 10 hours. A cured product can be obtained by heating to .

In addition, the epoxy resin composition of the present invention may contain a solvent as necessary. An epoxy resin composition (epoxy resin varnish) containing a solvent is prepared by impregnating a fibrous substance (base material) such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc., followed by heating and drying to obtain a prepreg. A cured product of the epoxy resin composition of the present invention can be obtained by press molding. The solvent content of this epoxy resin composition is usually 10 to 70% by weight, preferably about 15 to 70% by weight. Examples of the solvent include amide solvents such as γ-butyrolactones, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and N,N-dimethylimidazolidinone; sulfones such as tetramethylenesulfone; Ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monobutyl ether, preferably lower (1 to 3 carbon atoms) alkylene glycol mono- or di-lower (1 to 3 carbon atoms) 3) Alkyl ethers; ketone-based solvents such as methyl ethyl ketone and methyl isobutyl ketone, preferably two alkyl groups may be the same or different. Di-lower (C 1-3) alkyl ketones; aromatic solvents such as toluene and xylene; These may be used alone or as a mixed solvent of two or more.

Also, a sheet-like adhesive (the sheet of the present invention) can be obtained by coating the release film with the epoxy resin varnish, removing the solvent under heating, and performing B-stage. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates and the like.

The cured product obtained by the present invention can be used for various purposes. More specifically, general applications where thermosetting resins such as epoxy resins are used include adhesives, paints, coating agents, molding materials (including sheets, films, FRP, etc.), insulating materials (printed circuit boards, wire coating, etc.), sealing agents, additives to other resins, and the like.

Adhesives include adhesives for civil engineering, construction, automobiles, general office and medical use, as well as adhesives for electronic materials. Among them, adhesives for electronic materials include interlayer adhesives for multilayer substrates such as build-up substrates, die bonding agents, adhesives for semiconductors such as underfill, underfill for BGA reinforcement, anisotropic conductive films ( ACF), mounting adhesives such as anisotropic conductive paste (ACP), and the like.

Potting, dipping, transfer mold sealing for capacitors, transistors, diodes, light-emitting diodes, ICs, LSIs, etc., potting sealing for COBs, COFs, TABs of ICs, LSIs, flip chips, etc. and sealing (including reinforcing underfill) when mounting IC packages such as QFP, BGA, and CSP.

Next, the present invention will be described in more detail with reference to examples, but hereinafter parts are parts by weight unless otherwise specified. However, the present invention is not limited to these examples. In the examples, the epoxy equivalent was measured according to JIS K-7236, and the softening point was measured according to JIS K-7234.

・GPC (gel permeation chromatography) analysis column: SHODEX GPC KF-601 (2 columns), KF-602, KF-602.5, KF-603
Flow rate: 0.5 ml/min.
Column temperature: 40°C
Solvent used: THF (tetrahydrofuran)
Detector: RI (differential refraction detector)

[Synthesis Example 1]
100 parts of toluene, 84 parts of dicyclopentadiene type phenolic resin (hydroxyl group equivalent: 168 g/eq.), 58.0 parts of indene and 5 parts of methanesulfonic acid were added, heated to 125° C. and reacted for 6 hours. 150 parts of toluene was added, and the organic layer was washed with water until the waste liquid became neutral and then concentrated to obtain 115 parts of phenolic resin (P1). The number average molecular weight Mn was 686, the weight average molecular weight Mw was 854, and the hydroxyl group equivalent was 284.2 g/eq. A GPC chart is shown in FIG.

[Example 1]
Thermometer, cooling tube, fractionating tube, while purging a flask equipped with a stirrer, 110 parts of the phenolic resin (P1) obtained in Example 1, 143 parts of epichlorohydrin, 35.8 parts of dimethyl sulfoxide, water 1.4 parts was added, and the internal temperature was raised to 45°C. After adding 16 parts of sodium hydroxide in portions over 1.5 hours, the mixture was reacted at 45° C. for 2 hours and at 70° C. for 1 hour. Unreacted epichlorohydrin and the solvent were distilled off under heating and reduced pressure. 150 parts of MIBK was added, and the organic layer was washed once with 100 parts of water. The organic layer was returned to the reaction vessel, 15 parts of a 30 wt % sodium hydroxide aqueous solution was added, and the mixture was reacted at 70° C. for 2 hours. After standing to cool, the organic layer was washed four times with 100 parts of water, and the solvent was distilled off under heating and reduced pressure to obtain 123 parts of the target compound (E1) as a brown solid resin. Number average molecular weight Mn: 723, weight average molecular weight Mw: 953, epoxy equivalent is 360.5 g/eq. , ICI viscosity (150°C) was 1.07 Pa·s, and softening point was 95.2°C. A GPC chart is shown in FIG.

[Synthesis Example 2]
84 parts of dicyclopentadiene type phenolic resin (hydroxyl equivalent: 168 g/eq.), 54.2 parts of benzyl alcohol and 1.4 parts of p-toluenesulfonic acid monohydrate were added, and the temperature was raised to 150°C while distilling off the generated water. The temperature was raised and the reaction was allowed to proceed for 3 hours. 100 parts of toluene was added, and the organic layer was washed with water until the waste liquid became neutral and then concentrated to obtain 95 parts of phenolic resin (P2). The number average molecular weight Mn was 699, the weight average molecular weight Mw was 769, and the hydroxyl group equivalent was 258.1 g/eq. A GPC chart is shown in FIG.

[Synthesis Example 3]
Thermometer, cooling tube, fractionating tube, while purging a flask equipped with a stirrer, 80 parts of the phenol resin (P2) obtained in Synthesis Example 2, 115 parts of epichlorohydrin, 28.7 parts of dimethyl sulfoxide, water 1.3 parts was added, and the internal temperature was raised to 45°C. After adding 12.8 parts of sodium hydroxide in portions over 1.5 hours, the mixture was reacted at 45° C. for 2 hours and at 70° C. for 1 hour. Unreacted epichlorohydrin and the solvent were distilled off under heating and reduced pressure. 146 parts of MIBK was added and the organic layer was washed once with 100 parts of water. The organic layer was returned to the reaction vessel, 15 parts of a 30 wt % sodium hydroxide aqueous solution was added, and the mixture was reacted at 70° C. for 2 hours. After standing to cool, the organic layer was washed three times with 100 parts of water, and the solvent was distilled off under heating and reduced pressure to obtain the target compound (E2) as a brown solid resin. Number average molecular weight Mn: 698, weight average molecular weight Mw: 824, epoxy equivalent is 332.1 g/eq. , the ICI viscosity (150°C) was 0.08 Pa·s, and the softening point was 59.8°C. A GPC chart is shown in FIG.

[Example 2, Comparative Examples 1 to 3]
Epoxy resin (E1) obtained in Example 1, epoxy resin (E2) obtained in Synthesis Example 3, bisphenol F type epoxy resin (RE-304S, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 169 g/eq.) , Epoxy resin derived from dicyclopentadiene type phenol resin (XD-1000-2L, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 238 g / eq., ICI viscosity (150 ° C.): 0.05, softening point: 55.4 ° C. ) and 4,4'-methylenebis (2,6-diethylaniline) (manufactured by Nippon Kayaku Co., Ltd., KAYABOND C-300S) as a curing agent, and blended in the proportions (parts by weight) shown in Table 1, and a mixing roll The mixture was uniformly mixed and kneaded using the mixture, and after demolding, it was cured under the conditions of 160° C. for 2 hours and 180° C. for 6 hours to obtain a test piece for evaluation.

<Measurement of cured physical properties>
Table 1 shows the results of measurement of the test piece for evaluation under the following conditions.

<Heat resistance test>
A dynamic viscoelasticity tester was used to measure the glass transition temperature (the temperature at which tan δ reaches its maximum value).
・ Dynamic viscoelasticity measuring instrument: DMA-2980 manufactured by TA-instruments
・Temperature increase rate: 2°C/min

<Flexural modulus>
Measured according to JIS K-6911.
・ Tensilon: RTG-1310 (manufactured by A & D Company, Limited)
・Measurement temperature: room temperature

<Water absorption rate>
A disk-shaped test piece of 5 cm in diameter and 4 mm in thickness was kept under water immersion conditions at 100° C. for 24 hours, and then the mass change was calculated.

From the results in Table 1, it was confirmed that Example 2 had high heat resistance, high elastic modulus, and low water absorption.

The epoxy resin of the present invention is used as an insulating material for electrical and electronic parts (such as a highly reliable semiconductor sealing material), a laminate (such as a printed wiring board, a BGA substrate, and a build-up substrate), and an adhesive (such as a conductive adhesive). It is useful for various composite materials such as CFRP and coatings, and is particularly useful for various composite materials such as CFRP that strongly require a high elastic modulus.

Claims

An epoxy resin represented by the following formula (1).

(In formula (1), n is the number of repetitions, the average value of which is 1<n<20. R represents a substituent represented by the following formula (2). p is a real number of 0 to 4, respectively. and the average value of p is 0.5 to 1.5.)

(In formula (2), * represents a bond to the aromatic ring of formula (1). X represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. q represents a real number of 0 to 5. )
An epoxy resin represented by the following formula (3).

(In formula (3), n is the number of repetitions, and the average value is 1<n<20.)
The epoxy resin according to claim 1 or 2, which has a weight average molecular weight of 400 to 3000 by gel permeation chromatography (GPC).
A curable resin composition containing the epoxy resin according to any one of claims 1 to 3.
The curable resin composition according to claim 4, which further contains an amine-based curing agent.
A cured product obtained by curing the curable resin composition according to claim 4 or 5.
4. The method according to any one of claims 1 to 3, comprising a step of reacting a polycondensate of a dicyclopentadiene-based compound and a phenol-based compound with an indene derivative to obtain a phenolic resin, and a step of epoxidizing the phenolic resin. A method for producing the epoxy resin according to .