JP6874359B2 - Epoxy resin, epoxy resin composition and cured product thereof - Google Patents

Description

The present invention has an excellent balance between low shrinkage rate during heat curing and elastic modulus during heat, and an epoxy resin that can be suitably used as a semiconductor encapsulating material, an epoxy resin composition containing the epoxy resin, and curing thereof. Regarding things.

A curable resin composition using an epoxy resin and various curing agents is used as an adhesive, a molding material, a paint, a photoresist material, a coloring material, etc., and also has excellent heat resistance and moisture resistance of the obtained cured product. It is widely used in the electrical and electronic fields such as semiconductor encapsulants and insulating materials for printed wiring boards because of its excellent properties.

Among these various applications, with the trend toward miniaturization and weight reduction of electronic devices, there is a remarkable tendency for the density to increase due to the narrowing of the wiring pitch of semiconductor devices. A flip-chip connection method for joining a device and a substrate is widely used. This flip-chip connection method is a semiconductor mounting method based on the so-called reflow method in which solder balls are placed between the wiring board and the semiconductor, and the entire surface is heated for fusion bonding. Therefore, the wiring plate itself is exposed to a high thermal environment during solder reflow. As a result, warpage occurs due to heat shrinkage of the wiring board, and a large stress is generated in the solder balls connecting the wiring board and the semiconductor, which may cause a poor connection of the wiring. That is, in order to suppress the warp of the wiring board, the sealing resin is also required to have a low shrinkage rate and a low elastic modulus.

As an epoxy resin that can be suitably used as a semiconductor encapsulant, an epoxy resin having an allyl group as a substituent on the aromatic ring of the bisphenol skeleton is provided (see, for example, Patent Document 1). Alternatively, it is also known that a naphthylene ether skeleton-containing epoxy resin which may have a substituent on the aromatic ring is preferably used as a semiconductor encapsulant (see, for example, Patent Document 2).

As described above, by using an epoxy resin having a substituent on the aromatic ring as the main agent of the curable resin composition, the fluidity of the composition and the cured product are higher than those in the case of using a general bisphenol type epoxy resin. Although a certain effect on the strength can be obtained, the balance level of the molding shrinkage rate and the thermal elastic modulus during heat curing of the resin composition required in recent years cannot be sufficiently satisfied, and further improvement is required.

JP 2015-000952 Japanese Unexamined Patent Publication No. 2016-89096

Therefore, the problem to be solved by the present invention is to provide an epoxy resin, a composition, and a cured product thereof, which have an excellent balance between a molding shrinkage rate during heat curing and a thermal elastic modulus of a composition containing an epoxy resin. It is in.

As a result of diligent studies to solve the above problems, the present inventors have made a curable composition of an epoxidized product of a novolak resin of an alkylphenol having an alkyl group having 4 to 8 carbon atoms as a substituent on the aromatic ring and a monomer thereof. When used as one component of the above, it was found that the balance between the molding shrinkage rate at the time of heat curing and the elastic modulus at the time of heat was excellent, and the present invention was completed.

That is, the present invention has the following structural formula (1).

〔構造式（１）中、Ｒ^１、Ｒ^２、Ｒ^３はそれぞれ独立して水素原子又は炭素数４〜８のアルキル基であり、少なくともいずれか１つは炭素数４〜８のアルキル基である。Ｇはグリシジル基であり、ｎは繰り返す数を示し、平均値で０．０１〜２．０であり、繰り返し毎にＲ^１、Ｒ^２、Ｒ^３は同一でも異なっていてもよい。〕と下記構造式（２）

[In the structural formula (1), R ¹ , R ² , and R ³ are independently hydrogen atoms or alkyl groups having 4 to 8 carbon atoms, and at least one of them is an alkyl group having 4 to 8 carbon atoms. is there. G is a glycidyl group, n indicates the number of repetitions, and the average value is 0.01 ^{to 2.0, and R 1} , R ² , and R ³ may be the same or different for each repetition. ] And the following structural formula (2)

〔構造式（２）中、Ｒ^１、Ｒ^２、Ｒ^３はそれぞれ独立して水素原子又は炭素数４〜８のアルキル基であり、少なくともいずれか１つは炭素数４〜８のアルキル基であり、Ｇはグリシジル基である。〕を必須成分として含み、前記構造式（２）の含有率がＧＰＣ測定における面積比率で０．１〜２．０％であり、且つそのエポキシ当量が２４５〜３３０ｇ／ｅｑの範囲であることを特徴とするエポキシ樹脂、およびこれ含むエポキシ樹脂組成物とその硬化物を提供するものである。

[In structural formula (2), R ¹ , R ² , and R ³ are independently hydrogen atoms or alkyl groups having 4 to 8 carbon atoms, and at least one of them is an alkyl group having 4 to 8 carbon atoms. Yes, G is a glycidyl group. ] As an essential component, the content of the structural formula (2) is 0.1 to 2.0% in terms of area ratio in GPC measurement, and its epoxy equivalent is in the range of 245 to 330 g / eq. The present invention provides a characteristic epoxy resin, an epoxy resin composition containing the same, and a cured product thereof.

According to the present invention, an epoxy resin, an epoxy resin composition, and the above-mentioned performance, which are excellent in the balance between the molding shrinkage rate at the time of heat curing and the hot elasticity rate of the resin composition and can be suitably used for semiconductor encapsulation materials and the like. It is possible to provide a cured product, a semiconductor encapsulating material, a semiconductor device, a prepreg, a circuit board, a build-up film, a build-up board, a fiber-reinforced composite material, and a fiber-reinforced molded product.

FIG. 1 is a GPC chart of the epoxy resin synthesized in Synthesis Example 1. FIG. 2 is a GPC chart of the epoxy resin synthesized in Synthesis Example 2.

<Epoxy resin>
Hereinafter, the present invention will be described in detail.
The epoxy resin of the present invention has the following structural formula (1).

〔構造式（１）中、Ｒ^１、Ｒ^２、Ｒ^３はそれぞれ独立して水素原子又は炭素数４〜８のアルキル基であり、少なくともいずれか１つは炭素数４〜８のアルキル基である。Ｇはグリシジル基であり、ｎは繰り返す数を示し、平均値で０．０１〜２．０であり、繰り返し毎にＲ^１、Ｒ^２、Ｒ^３は同一でも異なっていてもよい。〕と下記構造式（２）

[In the structural formula (1), R ¹ , R ² , and R ³ are independently hydrogen atoms or alkyl groups having 4 to 8 carbon atoms, and at least one of them is an alkyl group having 4 to 8 carbon atoms. is there. G is a glycidyl group, n indicates the number of repetitions, and the average value is 0.01 ^{to 2.0, and R 1} , R ² , and R ³ may be the same or different for each repetition. ] And the following structural formula (2)

〔構造式（２）中、Ｒ^１、Ｒ^２、Ｒ^３はそれぞれ独立して水素原子又は炭素数４〜８のアルキル基であり、少なくともいずれか１つは炭素数４〜８のアルキル基であり、Ｇはグリシジル基である。〕を必須成分として含み、前記構造式（２）の含有率がＧＰＣ測定における面積比率で０．１〜２．０％であり、且つそのエポキシ当量が２４５〜３３０ｇ／ｅｑの範囲であることを特徴とする。

[In structural formula (2), R ¹ , R ² , and R ³ are independently hydrogen atoms or alkyl groups having 4 to 8 carbon atoms, and at least one of them is an alkyl group having 4 to 8 carbon atoms. Yes, G is a glycidyl group. ] As an essential component, the content of the structural formula (2) is 0.1 to 2.0% in terms of area ratio in GPC measurement, and its epoxy equivalent is in the range of 245 to 330 g / eq. It is a feature.

When n in the structural formula (1) is out of the range of 0.01 to 2.0, specifically, when it is less than 0.01 , the heat resistance is lowered due to the low crosslink density, resulting in molding shrinkage. The rate increases. When n exceeds 2.0 , the epoxidation reaction of the hydroxyl groups in the raw material phenol novolac does not proceed well, and as a result, the epoxy equivalent increases, and as a result, it tends to be difficult to balance the thermal elastic modulus and the molding shrinkage. There is.

The content of the structural formula (2) in the epoxy resin of the present invention is 0.1 in terms of the area ratio in GPC measurement because the molding shrinkage can be reduced while significantly reducing the thermal elastic modulus during heat curing. It is preferably ~ 2.0%. If it is less than 0.1%, the decrease in elastic modulus during heat is insufficient, and if it exceeds 2.0%, the crosslink density is significantly decreased, and the shrinkage during cooling after heat curing is large. As a result, the shrinkage rate during molding becomes large.

Since the epoxy resin of the present invention has an alkyl group having 4 to 8 carbon atoms as a substituent on the aromatic ring, the crosslink density during the curing reaction is appropriately adjusted due to its bulkiness, and during heat curing. It is considered that the balance between the molding shrinkage rate and the thermal elastic modulus is excellent. In particular, when a cured product is obtained using a curing agent as described later, the t-butyl group and t-octyl are used from the viewpoint that the curing reaction proceeds well and the cross-linking density of the cured product can be easily set in a more appropriate range. It is preferably an alkyl group having a branched structure such as a group, and most preferably a t-butyl group.

Further, in the epoxy resin of the present invention, ^{it is preferable that R 1} in the structural formulas (1) and (2) is an alkyl group having 4 to 8 carbon atoms, and R ² and R ³ are hydrogen atoms, particularly R. ^{It is} preferable that any one or two of 1, R ² and R ³ are t-butyl groups in terms of excellent molding shrinkage and thermal elastic modulus of the cured product, and R ¹ is a t-butyl group. It is even more preferable that R ² and R ^{3 are hydrogen atoms.}

Further, the epoxy equivalent of the epoxy resin of the present invention is essential to be in the range of 245 to 330 g / eq from the viewpoint of the balance between the molding shrinkage rate at the time of heat curing and the elastic modulus at the time of heating. The range is preferably in the range of 245 to 300 g / eq from the viewpoint of further enhancing the effect.

The n of the structural formula (1) of the epoxy resin in the present invention and the content of the structural formula (2) are calculated by GPC measurement under the following conditions.
<GPC measurement conditions>
Measuring device: "HLC-8320 GPC" manufactured by Tosoh Corporation,
Column: Guard column "HXL-L" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G3000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G4000HXL" manufactured by Tosoh Corporation
Detector: RI (Differential Refractometer)
Data processing: "GPC Workstation EcoSEC-WorkStation" manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Developing solvent tetrahydrofuran
Flow velocity 1.0 ml / min Standard: The following monodisperse polystyrene with a known molecular weight was used in accordance with the measurement manual of the above-mentioned "GPC workstation EcoSEC-WorkStation".
(Polystyrene used)
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation
"F-40" manufactured by Tosoh Corporation
"F-80" manufactured by Tosoh Corporation
"F-128" manufactured by Tosoh Corporation
Sample: A solution of 1.0% by mass in terms of resin solid content in tetrahydrofuran filtered with a microfilter (50 μl).

<Epoxy resin manufacturing method>
As described above, the epoxy resin of the present invention is composed of the compounds represented by the above-mentioned structural formulas (1) and (2). As a method for obtaining such an epoxy resin, a method of obtaining an alkylphenol novolak resin having an alkyl group having 4 to 8 carbon atoms as a substituent on the aromatic ring and then epoxidizing the resin is industrially productive. Excellent.

Examples of the alkylphenol having an alkyl group having 4 to 8 carbon atoms as a substituent on the aromatic ring include t-butylphenol, di-t-butylphenol, t-octylphenol and the like, and are composed of only one kind. Alternatively, two or more kinds may be mixed and used. Among these, from the viewpoint of the heat shrinkage rate of the curable resin composition using the obtained epoxy resin, it is preferable that the curable resin composition has an alkyl group having a bulkier structure, the raw material is easily available, and the obtained resin is obtained. From the viewpoint of the curing characteristics of the composition, it is preferable to use pt-butylphenol, ot-butylphenol, 2,4-di-t-butylphenol, pt-octylphenol, and pt-butylphenol. Most preferably used.

Examples of the method for obtaining the novolak resin of alkylphenol include a method of reacting aldehydes with aldehydes under an acidic catalyst at 50 to 180 ° C.

The aldehydes may be any aldehydes that can form a novolak type resin by undergoing a condensation reaction with the above-mentioned alkylphenols, and examples thereof include formaldehyde, trioxane, propitetraoxymethylene, and polyoxymethylene . Each of these may be used alone, or two or more types may be used in combination. Of these, formaldehyde is preferably used because of its excellent reactivity. Formaldehyde may be used as formalin in an aqueous solution state or as paraformaldehyde in a solid state.

The acidic catalyst includes, for example, inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, organic acids such as methanesulfonic acid, paratoluenesulfonic acid and oxalic acid, and Lewis such as boron trifluoride, aluminum chloride and zinc chloride. Acids and the like can be mentioned. Each of these may be used alone, or two or more types may be used in combination.

As a method for efficiently obtaining a novolak resin, for example, the aldehydes are used in the range of 0.05 to 0.40 mol with respect to 1 mol of the hydroxyl group in the alkylphenol, and the temperature is 50 to 180 ° C. in the presence of the acidic catalyst. Examples thereof include a method of reacting under temperature conditions.

The reaction between the alkylphenol and the aldehydes may be carried out in a solvent, if necessary. The solvent used here is, for example, water; methanol, ethanol, propanol, ethyl lactate, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and the like. 1,6-Hexanediol, 1,7-Heptanediol, 1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethylene glycol, glycerin, 2-ethoxyethanol, ethylene glycol monomethyl ether, ethylene Glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol monophenyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, 1, Examples thereof include 3-dioxane, 1,4-dioxane, tetrahydrofuran, ethylene glycol acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, N-methylpyrrolidone, dimethylformamide, dimethylsulfoxide and the like. Each of these solvents may be used alone or as a mixed solvent of two or more kinds.

After completion of the reaction, if necessary, a step of distilling off unreacted raw materials, a solvent, etc., a step of purifying by washing with water, reprecipitation, or the like may be performed.

The method for producing an epoxy resin of the present invention is a method for producing an epoxy resin in which the raw material novolak resin is reacted with epihalohydrin to epoxidize as described above, and a known technique can be appropriately applied to the method for epoxidation.

For example, for epihalohydrin, 1 to 10 mol is added to 1 mol of the hydroxyl group contained in the raw material novolak resin, and 0.9 to 2.0 mol of the basic catalyst is added all at once to 1 mol of the raw material hydroxyl group. Alternatively, a method of reacting at a temperature of 20 to 120 ° C. for 0.5 to 10 hours with gradual addition can be mentioned. This basic catalyst may be solid or an aqueous solution thereof may be used. When an aqueous solution is used, water and epihalohydrins are continuously added from the reaction mixture under reduced pressure or under normal pressure. It may be dispensed, further separated to remove water, and epihalohydrins may be continuously returned to the reaction mixture.

During industrial production, all of the epihalohydrins used for preparation are new in the first batch of epoxy resin production, but after the next batch, they are consumed in the reaction with the epihalohydrins recovered from the crude reaction product. It is preferable to use in combination with new epihalohydrins corresponding to the amount that disappears in a certain amount. At this time, impurities such as glycidol, which are induced by the reaction of epichlorohydrin with water, an organic solvent, etc., may be contained. At this time, the epichlorohydrin used is not particularly limited, and examples thereof include epichlorohydrin, epibromohydrin, and β-methylepichlorohydrin. Among these, epichlorohydrin is preferable because it is industrially easily available.

Specific examples of the basic catalyst include alkaline earth metal hydroxides, alkali metal carbonates and alkali metal hydroxides. In particular, alkali metal hydroxides are preferable from the viewpoint of excellent catalytic activity in the epoxy resin synthesis reaction, and examples thereof include sodium hydroxide and potassium hydroxide. In use, these basic catalysts may be used in the form of an aqueous solution of about 10% by mass to 55% by mass, or may be used in the form of a solid. Further, by using an organic solvent in combination, the reaction rate in the synthesis of the epoxy resin can be increased. Such an organic solvent is not particularly limited, but for example, ketones such as acetone and methyl ethyl ketone, alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butanol, secondary butanol and tertiary butanol, and methyl. Examples thereof include cellosolves such as cellosolve and ethyl cellosolve, ethers such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane and diethoxyethane, and aprotonic polar solvents such as acetonitrile, dimethylsulfoxide and dimethylformamide. Each of these organic solvents may be used alone, or two or more kinds may be used in combination as appropriate to adjust the polarity.

Subsequently, the reaction product of the above-mentioned epoxidation reaction is washed with water, and then the unreacted epihalohydrin and the organic solvent used in combination are distilled off by distillation under heating and reduced pressure. Further, in order to obtain an epoxy resin having less hydrolyzable halogen, the obtained epoxy resin is dissolved again in an organic solvent such as toluene, methyl isobutyl ketone and methyl ethyl ketone, and alkali metal hydroxide such as sodium hydroxide and potassium hydroxide is used. The reaction can be further carried out by adding an aqueous solution of the substance. At this time, a phase transfer catalyst such as a quaternary ammonium salt or a crown ether may be present for the purpose of improving the reaction rate. When the phase transfer catalyst is used, the amount used is preferably in the range of 0.1% by mass to 3.0% by mass with respect to the epoxy resin used. After completion of the reaction, the produced salt is removed by filtration, washing with water, or the like, and further, a solvent such as toluene or methyl isobutyl ketone is distilled off under heating and reduced pressure to obtain a high-purity epoxy resin.

<Epoxy resin composition>
The epoxy resin of the present invention can be used in combination with a curing agent (B). By blending a curing agent with the epoxy resin, a curable epoxy resin composition can be produced.

Examples of the curing agent (B) that can be used here include various known curing agents for epoxy resins such as amine compounds, amide compounds, acid anhydride compounds, and phenol compounds.

Specifically, diaminodiphenylmethane as amine compound, diethylenetriamine, triethylenetetramine, diaminodiphenyl sulfone, isophoronediamine, imidazo - Le, BF 3 _- amine complex, guanidine derivatives and the like, Examples of the amide compounds include dicyandiamide , Polyamide resin synthesized by a dimer of linolenic acid and ethylenediamine, and the like. Examples of acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydro. Examples include phthalic anhydride. Examples of phenolic compounds include phenol novolac resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin-modified phenol resin, dicyclopentadienephenol-added resin, phenol aralkyl resin (Zyroc resin), naphthol aralkyl resin, and triphenylol methane resin. Tetraphenylol ethane resin, naphthol novolac resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin (polyphenolic hydroxyl group-containing compound in which phenol nuclei are linked by bismethylene groups), biphenyl Modified naphthol resin (polyvalent naphthol compound in which phenol nuclei are linked by bismethylene group), aminotriazine-modified phenol resin (polyvalent phenolic hydroxyl group-containing compound in which phenol nuclei are linked by melamine, benzoguanamine, etc.) and alkoxy group-containing aromatic ring Examples thereof include polyhydric phenolic hydroxyl group-containing compounds such as modified novolak resin (polyhydric phenolic hydroxyl group-containing compound in which a phenol nucleus and an alkoxy group-containing aromatic ring are linked with formaldehyde).

Further, an epoxy resin (C) other than the epoxy resin of the present invention can be used in combination with the epoxy resin composition of the present invention as long as the effects of the present invention are not impaired.

Examples of the epoxy resin (C) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, polyhydroxynaphthalene type epoxy resin, phenol novolac type epoxy resin, and cresol novolac. Type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol Examples thereof include co-shrink novolak type epoxy resin, naphthol-cresol co-shrink novolak type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, and biphenyl-modified novolak type epoxy resin. Among these epoxy resins, tetramethylbiphenol type epoxy resin, biphenylaralkyl type epoxy resin, polyhydroxynaphthalene type epoxy resin, and novolac type epoxy resin can be used in terms of obtaining a cured product having particularly excellent flame retardancy. A dicyclopentadiene-phenol addition reaction type epoxy resin is preferable in that a cured product having excellent dielectric properties can be obtained. When the other epoxy resin (C) is used in combination, the epoxy resin of the present invention may be contained in an amount of 10 to 90 parts by mass with respect to a total of 100 parts by mass of the epoxy resin of the present invention and the epoxy resin (C). It is preferable from the viewpoint that the effect of the present invention can be easily exhibited.

In the epoxy resin composition of the present invention, the blending amount of the epoxy resin of the present invention and the curing agent (B) is the epoxy resin (C) to be used in combination with the epoxy resin of the present invention as necessary from the viewpoint of excellent curability. It is preferable that the total amount of active groups in the curing agent (B) is 0.8 to 1.2 equivalents with respect to the total amount of 1 equivalent of the epoxy groups contained therein.

Further, the epoxy resin composition may be used in combination with other thermosetting resins.

Examples of other thermosetting resins include cyanate ester resins, resins having a benzoxazine structure, maleimide compounds, active ester resins, vinylbenzyl compounds, acrylic compounds, copolymers of styrene and maleic acid anhydride, and the like. .. When the other thermosetting resin described above is used in combination, the amount used is not particularly limited as long as the effect of the present invention is not impaired, but it should be in the range of 1 to 50 parts by mass out of 100 parts by mass of the resin composition. Is preferable.

Examples of the cyanate ester resin include bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, bisphenol S type cyanate ester resin, bisphenol sulfide type cyanate ester resin, and phenylene ether type cyanate ester resin. , Naftyrene ether type cyanate ester resin, biphenyl type cyanate ester resin, tetramethylbiphenyl type cyanate ester resin, polyhydroxynaphthalene type cyanate ester resin, phenol novolac type cyanate ester resin, cresol novolac type cyanate ester resin, triphenylmethane type cyanate Ester resin, tetraphenylethane type cyanate ester resin, dicyclopentadiene-phenol addition reaction type cyanate ester resin, phenol aralkyl type cyanate ester resin, naphthol novolac type cyanate ester resin, naphthol aralkyl type cyanate ester resin, naphthol-phenol co-condensed novolak Examples thereof include type cyanate ester resin, naphthol-cresol co-condensed novolak type cyanate ester resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type cyanate ester resin, biphenyl modified novolak type cyanate ester resin, and anthracene type cyanate ester resin. Each of these may be used alone, or two or more types may be used in combination.

Among these cyanate ester resins, bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, and polyhydroxynaphthalene type cyanate ester resin are particularly excellent in heat resistance. , Naftylene ether type cyanate ester resin and novolak type cyanate ester resin are preferably used, and dicyclopentadiene-phenol addition reaction type cyanate ester resin is preferable in that a cured product having excellent dielectric properties can be obtained.

The resin having a benzoxazine structure is not particularly limited, but for example, a reaction product of bisphenol F, formalin and aniline (FA type benzoxazine resin) or a reaction product of diaminodiphenylmethane, formalin and phenol (P-). d-type benzoxazine resin), reaction product of bisphenol A, formalin and aniline, reaction product of dihydroxydiphenyl ether, formalin and aniline, reaction product of diaminodiphenyl ether, formalin and phenol, dicyclopentadiene-phenol-added resin and formalin And aniline reaction products, phenolphthalein, formalin and aniline reaction products, diphenylsulfide, formalin and aniline reaction products, and the like. Each of these may be used alone, or two or more types may be used in combination.

Examples of the maleimide compound include various compounds represented by any of the following structural formulas (i) to (iii).

（式中Ｒはｍ価の有機基であり、α及びβはそれぞれ水素原子、ハロゲン原子、アルキル基、アリール基の何れかであり、ｓは１以上の整数である。）

(In the formula, R is an m-valent organic group, α and β are any of a hydrogen atom, a halogen atom, an alkyl group, and an aryl group, respectively, and s is an integer of 1 or more.)

(In the formula, R is any of a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxyl group, and an alkoxy group, s is an integer of 1 to 3, and t is an average of 0 to 10 in repeating units. .)

（式中Ｒは水素原子、アルキル基、アリール基、アラルキル基、ハロゲン原子、水酸基、アルコキシ基の何れかであり、ｓは１〜３の整数、ｔは繰り返し単位の平均で０〜１０である。）これらはそれぞれ単独で用いても良いし、２種類以上を併用しても良い。

(In the formula, R is any of a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, a halogen atom, a hydroxyl group, and an alkoxy group, s is an integer of 1 to 3, and t is an average of 0 to 10 in repeating units. .) Each of these may be used alone, or two or more types may be used in combination.

The active ester resin is not particularly limited, but generally contains an ester group having high reactive activity such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds in one molecule. A compound having two or more is preferably used. The active ester resin is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound or a halide thereof and a hydroxy compound is preferable, and an active ester resin obtained from a carboxylic acid compound or a halide thereof and a phenol compound and / or a naphthol compound is preferable. More preferred. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid and the like, or halides thereof. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, dihydroxydiphenyl ether, phenol phthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m. -Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenol, trihydroxybenzophenone, tetrahydroxybenzophenone, fluoroglusin , Benzintriol, dicyclopentadiene-phenol-added resin and the like.

Specific examples of the active ester resin include an active ester resin containing a dicyclopentadiene-phenol addition structure, an active ester resin containing a naphthalene structure, an active ester resin which is an acetylated product of phenol novolac, and an activity which is a benzoyl product of phenol novolac. Ester resins and the like are preferable, and among them, an active ester resin containing a dicyclopentadiene-phenol addition structure and an active ester resin containing a naphthalene structure are more preferable in that they are excellent in improving peel strength. Specific examples of the active ester resin containing a dicyclopentadiene-phenol addition structure include compounds represented by the following general formula (iv).

However, in the formula (iv), R is a phenyl group or a naphthyl group, u represents 0 or 1, and n is an average of 0.05 to 2.5 in repeating units. From the viewpoint of reducing the dielectric loss tangent of the cured product of the resin composition and improving the heat resistance, R is preferably a naphthyl group, u is preferably 0, and n is preferably 0.25 to 1.5. ..

The epoxy resin composition of the present invention can be cured even with the epoxy resin composition alone, but a curing accelerator may be used in combination. As the curing accelerator, tertiary amine compounds such as imidazole and dimethylaminopyridine; phosphorus compounds such as triphenylphosphine; boron trifluoride amine complex such as boron trifluoride and boron trifluoride monoethylamine complex; thiodipropion. Organic acid compounds such as acids; benzoxazine compounds such as thiodiphenol benzoxazine and sulfonylbenzoxazine; sulfonyl compounds and the like can be mentioned. Each of these may be used alone, or two or more types may be used in combination. The amount of these catalysts added is preferably in the range of 0.001 to 15 parts by mass in 100 parts by mass of the epoxy resin composition.

Further, when the epoxy resin composition of the present invention is used in an application where high flame retardancy is required, a non-halogen flame retardant which does not substantially contain a halogen atom may be blended.

Examples of the non-halogen flame retardant include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, organic metal salt flame retardants, and the like, and their use is also restricted. It may be used alone, a plurality of flame retardants of the same system may be used, and flame retardants of different systems may be used in combination.

As the phosphorus-based flame retardant, either an inorganic type or an organic type can be used. Examples of the inorganic compound include ammonium phosphates such as red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate and ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphate amide. ..

The red phosphorus is preferably surface-treated for the purpose of preventing hydrolysis and the like, and examples of the surface treatment method include (i) magnesium hydroxide, aluminum hydroxide, zinc hydroxide, and water. A method of coating with an inorganic compound such as titanium oxide, bismuth oxide, bismuth hydroxide, bismuth nitrate or a mixture thereof, (ii) inorganic compounds such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide and titanium hydroxide, and Method of coating with a mixture of thermosetting resins such as phenol resin, (iii) Thermocurability of phenol resin or the like on a film of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide Examples thereof include a method of double coating with resin.

The organic phosphorus compounds include, for example, general-purpose organic phosphorus compounds such as phosphoric acid ester compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphoran compounds, and organic nitrogen-containing phosphorus compounds, as well as 9,10-dihydro. -9-Oxa-10-phosphaphenanthrene-10-oxide, 10- (2,5-dihydrooxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,7-) Examples thereof include cyclic organophosphorus compounds such as dihydrooxynaphthyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide and derivatives obtained by reacting the cyclic organophosphorus compounds with compounds such as epoxy resins and phenol resins.

The blending amount of these phosphorus-based flame retardants is appropriately selected depending on the type of the phosphorus-based flame retardant, other components of the resin composition, and the desired degree of flame retardancy. For example, a non-halogen flame retardant. When red phosphorus is used as a non-halogen flame retardant, it is blended in the range of 0.1 parts by mass to 2.0 parts by mass in 100 parts by mass of the resin composition containing all of the fillers and other additives. In the same way, when an organic phosphorus compound is used, it is preferably blended in the range of 0.1 parts by mass to 10.0 parts by mass, and blended in the range of 0.5 parts by mass to 6.0 parts by mass. It is more preferable to do so.

When the phosphorus-based flame retardant is used, hydrotalcite, magnesium hydroxide, boron compound, zirconium oxide, black dye, calcium carbonate, zeolite, zinc molybdate, activated charcoal, etc. may be used in combination with the phosphorus-based flame retardant. Good.

Examples of the nitrogen-based flame retardant include triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, and phenothiazine, and triazine compounds, cyanuric acid compounds, and isocyanuric acid compounds are preferable.

The triazine compound includes, for example, melamine, acetoguanamine, benzoguanamine, melon, melam, succinoguanamine, ethylenedimelamine, polyphosphate melamine, triguanamine and the like, and for example, (1) guanyl melamine sulfate, melem sulfate, melam sulfate. Aminotriazine sulfate compounds such as (2) Phenols such as phenol, cresol, xylenol, butylphenol and nonylphenol, and melamines such as melamine, benzoguanamine, acetguanamine and formguanamine and formaldehyde cocondensate, (3) Examples thereof include a mixture of the cocondensate of (2) and a phenol resin such as a phenol formaldehyde condensate, and (4) the above (2) and (3) further modified with tung oil, isomerized flaxseed oil and the like.

Examples of the cyanuric acid compound include cyanuric acid and melamine cyanuric acid.

The blending amount of the nitrogen-based flame retardant is appropriately selected depending on the type of the nitrogen-based flame retardant, other components of the resin composition, and the desired degree of flame retardancy. For example, a non-halogen flame retardant. And other fillers, additives, etc. are all blended in the range of 0.05 to 10 parts by mass, preferably in the range of 0.1 parts by mass to 5 parts by mass, out of 100 parts by mass of the resin composition. It is more preferable to do so.

When using the nitrogen-based flame retardant, a metal hydroxide, a molybdenum compound, or the like may be used in combination.

The silicone-based flame retardant can be used without particular limitation as long as it is an organic compound containing a silicon atom, and examples thereof include silicone oil, silicone rubber, and silicone resin. The blending amount of the silicone flame retardant is appropriately selected depending on the type of the silicone flame retardant, other components of the resin composition, and the desired degree of flame retardancy. For example, a non-halogen flame retardant. It is preferable to blend in the range of 0.05 to 20 parts by mass in 100 parts by mass of the resin composition containing all of the other fillers and additives. Further, when using the silicone flame retardant, a molybdenum compound, alumina or the like may be used in combination.

Examples of the inorganic flame retardant include metal hydroxides, metal oxides, metal carbonate compounds, metal powders, boron compounds, and low melting point glass.

Examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, zirconium hydride and the like.

The metal oxide includes, for example, zinc molybdenum, molybdenum trioxide, zinc tinate, tin oxide, aluminum oxide, iron oxide, titanium oxide, manganese oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, and bismuth oxide. Examples thereof include chromium oxide, nickel oxide, copper oxide, and tungsten oxide.

Examples of the metal carbonate compound include zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, basic magnesium carbonate, aluminum carbonate, iron carbonate, cobalt carbonate, titanium carbonate and the like.

Examples of the metal powder include aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, nickel, copper, tungsten, tin and the like.

Examples of the boron compound include zinc borate, zinc metaborate, barium metaborate, boric acid, and borax.

The low melting point glass includes, for example, Shipley (Boxy Brown Co., Ltd.), hydrated glass SiO ₂ -MgO-H ₂ O, PbO-B ₂ O ₃ system, ZnO-P ₂ O _5- MgO system, P ₂ O ₅ -B ₂ O _3- PbO-MgO system, P-Sn-OF system, PbO-V ₂ O _5- TeO ₂ system, Al ₂ O _3- H ₂ O system, lead borosilicate glassy compounds, etc. Can be mentioned.

The blending amount of the inorganic flame retardant is appropriately selected depending on the type of the inorganic flame retardant, other components of the resin composition, and the desired degree of flame retardancy. For example, a non-halogen flame retardant. It is preferable to blend in the range of 0.05 parts by mass to 20 parts by mass, and in the range of 0.5 parts by mass to 15 parts by mass, out of 100 parts by mass of the resin composition containing all of the other fillers and additives. It is more preferable to mix with.

The organometallic salt-based flame retardant includes, for example, ferrocene, an acetylacetonate metal complex, an organometallic carbonyl compound, an organocobalt salt compound, an organosulfonic acid metal salt, a metal atom and an aromatic compound or a heterocyclic compound in an ionic bond or arrangement. Examples thereof include position-bonded compounds.

The blending amount of the organic metal salt-based flame retardant is appropriately selected depending on the type of the organic metal salt-based flame retardant, other components of the resin composition, and the desired degree of flame retardancy. It is preferable to blend in the range of 0.005 parts by mass to 10 parts by mass in 100 parts by mass of the resin composition containing all of the halogen-based flame retardant and other fillers and additives.

The epoxy resin composition of the present invention can be blended with an inorganic filler, if necessary. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide and the like. When the blending amount of the inorganic filler is particularly large, it is preferable to use molten silica. The molten silica can be used in either a crushed form or a spherical shape, but in order to increase the blending amount of the molten silica and suppress an increase in the melt viscosity of the molding material, it is preferable to mainly use a spherical one. Further, in order to increase the blending amount of spherical silica, it is preferable to appropriately adjust the particle size distribution of spherical silica. The filling rate is preferably high in consideration of flame retardancy, and is particularly preferably 20% by mass or more with respect to the total mass of the epoxy resin composition. When used for applications such as conductive paste, a conductive filler such as silver powder or copper powder can be used.

In addition to this, various compounding agents such as a silane coupling agent, a mold release agent, a pigment, and an emulsifier can be added to the epoxy resin composition of the present invention, if necessary.

<Use of epoxy resin composition>
The epoxy resin composition of the present invention can be applied to semiconductor encapsulant materials, semiconductor devices, prepregs, printed circuit boards, build-up substrates, build-up films, fiber-reinforced composite materials, fiber-reinforced resin molded products, conductive pastes, and the like. it can.

1. 1. Semiconductor encapsulation material As a method for obtaining a semiconductor encapsulation material from the epoxy resin composition of the present invention, an extruder such as the epoxy resin composition, the curing accelerator, and an inorganic filler can be used as necessary. Examples thereof include a method of sufficiently melting and mixing until the mixture becomes uniform using a feeder, roll or the like. At that time, fused silica is usually used as the inorganic filler, but when used as a high thermal conductivity semiconductor encapsulant for power transistors and power ICs, crystalline silica, alumina, and silicon nitride having higher thermal conductivity than fused silica are used. It is preferable to use high-filling silicon or the like, or use molten silica, crystalline silica, alumina, silicon nitride, or the like. It is preferable to use an inorganic filler in the range of 30% by mass to 95% by mass per 100 parts by mass of the epoxy resin composition, and among them, improvement of flame retardancy, moisture resistance and solder crack resistance, and linear expansion. In order to reduce the coefficient, 70 parts by mass or more is more preferable, and 80 parts by mass or more is further preferable.

2. Semiconductor device As a method for obtaining a semiconductor device from the epoxy resin composition of the present invention, the semiconductor encapsulant material is cast or molded using a transfer molding machine, an injection molding machine, or the like, and further at 50 to 200 ° C. for 2 to 2 A method of heating for 10 hours can be mentioned.

3. 3. Prepreg As a method for obtaining a prepreg from the epoxy resin composition of the present invention, a curable resin composition obtained by blending an organic solvent to form a varnish is used as a reinforcing base material (paper, glass cloth, glass non-woven fabric, aramid paper, aramid cloth, etc.). A method obtained by impregnating a glass mat, a glass roving cloth, etc.) and then heating at a heating temperature according to the type of the solvent used, preferably 50 to 170 ° C. can be mentioned. The mass ratio of the resin composition and the reinforcing base material used at this time is not particularly limited, but it is usually preferable to prepare the resin content in the prepreg to be 20% by mass to 60% by mass.

Examples of the organic solvent used here include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, propylene glycol monomethyl ether acetate and the like. It can be appropriately selected depending on the application, but for example, when further producing a printed circuit board from prepylene as described below, it is preferable to use a polar solvent having a boiling point of 160 ° C. or lower, such as methyl ethyl ketone, acetone, or dimethylformamide. , It is preferable to use the non-volatile content at a ratio of 40% by mass to 80% by mass.

4. Printed circuit board As a method for obtaining a printed circuit board from the epoxy resin composition of the present invention, the prepregs are laminated by a conventional method, copper foils are appropriately laminated, and 10 at 170 to 300 ° C. under a pressure of 1 to 10 MPa. Examples thereof include a method of heat-bonding for minutes to 3 hours.

5. Build-up substrate As a method for obtaining a build-up substrate from the epoxy resin composition of the present invention, a method via steps 1 to 3 can be mentioned. In step 1, first, the curable resin composition in which rubber, a filler and the like are appropriately mixed is applied to a circuit board on which a circuit is formed by a spray coating method, a curtain coating method, or the like, and then cured. In step 2, if necessary, the circuit board coated with the epoxy resin composition is drilled with a predetermined through-hole portion or the like, treated with a roughening agent, and the surface thereof is washed with hot water. Concavities and convexities are formed on the substrate, and a metal such as copper is plated. In step 3, the operations of steps 1 and 2 are sequentially repeated as desired, and the resin insulating layer and the conductor layer having a predetermined circuit pattern are alternately built up to form a build-up substrate. In the above step, the through-hole portion may be drilled after the outermost resin insulating layer is formed. Further, the build-up substrate of the present invention is roughened by heat-pressing a resin-containing copper foil obtained by semi-curing the resin composition on a copper foil onto a wiring board on which a circuit is formed at 170 to 300 ° C. It is also possible to produce a build-up substrate by omitting the steps of forming a chemical surface and plating.

6. Build-up film As a method of obtaining a build-up film from the epoxy resin composition of the present invention, for example, a curable resin composition is applied on a support film, dried, and a resin composition layer is formed on the support film. The method of forming is mentioned. When the epoxy resin composition of the present invention is used as a build-up film, the film is softened under the temperature conditions of lamination (usually 70 ° C. to 140 ° C.) in the vacuum lamination method, and is present on the circuit board at the same time as laminating the circuit board. It is important to show fluidity (resin flow) that allows resin filling in the via hole or through hole, and it is preferable to blend each of the above components so as to exhibit such characteristics.

Here, the diameter of the through hole of the circuit board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm, and it is usually preferable to enable resin filling in this range. When laminating both sides of a circuit board, it is desirable to fill about 1/2 of the through holes.

As a specific method for producing the build-up film described above, an epoxy resin composition which has been varnished by blending an organic solvent is prepared, and then the composition is applied to the surface of the support film (Y), and further. Examples thereof include a method of forming the layer (X) of the epoxy resin composition by drying the organic solvent by heating, blowing hot air, or the like.

Examples of the organic solvent used here include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, cellosolve and butyl carbitol and the like. Carbitols, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like are preferably used, and the non-volatile content is 30% by mass to 60% by mass. Is preferable.

The thickness of the layer (X) of the resin composition to be formed usually needs to be equal to or larger than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm. The layer (X) of the resin composition in the present invention may be protected by a protective film described later. By protecting with a protective film, it is possible to prevent dust and the like from adhering to the surface of the resin composition layer and scratches.

The support film and protective film described above include polyolefins such as polyethylene, polypropylene and polyvinyl chloride, polyethylene terephthalate (hereinafter, may be abbreviated as "PET"), polyesters such as polyethylene naphthalate, polycarbonate, polyimide, and further release. Examples include metal foils such as paper patterns, copper foils, and aluminum foils. The support film and the protective film may be subjected to a mold release treatment in addition to the mud treatment and the corona treatment. The thickness of the support film is not particularly limited, but is usually 10 to 150 μm, and is preferably used in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

The support film (Y) described above is peeled off after being laminated on a circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled off after the epoxy resin composition layer constituting the build-up film is heat-cured, it is possible to prevent the adhesion of dust and the like in the curing step. When peeling after curing, the support film is usually subjected to a mold release treatment in advance.

A multilayer printed circuit board can be manufactured from the build-up film obtained as described above. For example, when the layer (X) of the resin composition is protected by a protective film, the layers (X) of the resin composition are peeled off, and then one side or both sides of the circuit board are brought into direct contact with the layer (X) of the resin composition. , For example, by the vacuum laminating method. The laminating method may be a batch method or a continuous method using a roll. If necessary, the build-up film and the circuit board may be preheated if necessary before laminating. As for the laminating conditions, the crimping temperature (lamination temperature) is preferably 70 to 140 ° C., and the crimping pressure is 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ). It is preferable to laminate under a reduced air pressure of 20 mmHg (26.7 hPa) or less.

7. Fiber Reinforced Composite Material As a method of obtaining a fiber reinforced composite material (sheet-like intermediate material in which the resin is impregnated in the reinforcing fibers) from the epoxy resin composition of the present invention, each component constituting the epoxy resin composition is uniformly mixed. The varnish is prepared, then impregnated with a reinforcing base material made of reinforcing fibers, and then subjected to a polymerization reaction to produce the varnish.

Specifically, the curing temperature at the time of carrying out such a polymerization reaction is preferably in the temperature range of 50 to 250 ° C., in particular, after curing at 50 to 100 ° C. to obtain a tack-free cured product, further , 120-200 ° C. is preferable.

Here, the reinforcing fiber may be any of twisted yarn, untwisted yarn, untwisted yarn and the like, but the untwisted yarn and the untwisted yarn are preferable because both the moldability and the mechanical strength of the fiber-reinforced plastic member are compatible. Further, as the form of the reinforcing fiber, one in which the fiber directions are aligned in one direction or a woven fabric can be used. For woven fabrics, plain weaves, satin weaves, and the like can be freely selected according to the part to be used and the intended use. Specific examples thereof include carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, and silicon carbide fiber because of their excellent mechanical strength and durability, and two or more of these can be used in combination. Among these, carbon fibers are particularly preferable from the viewpoint of improving the strength of the molded product, and various carbon fibers such as polyacrylonitrile-based, pitch-based, and rayon-based can be used. Of these, polyacrylonitrile-based ones, which can easily obtain high-strength carbon fibers, are preferable. Here, the amount of the reinforcing fiber used when impregnating the reinforcing base material made of the reinforcing fiber with the varnish to obtain the fiber-reinforced composite material is such that the volume content of the reinforcing fiber in the fiber-reinforced composite material is 40% to 85%. The amount is preferably in the range of.

8. Fiber-reinforced resin molded product As a method of obtaining a fiber-reinforced molded product (molded product in which a sheet-like member impregnated with resin impregnated in reinforcing fibers is cured) from the epoxy resin composition of the present invention, a fiber aggregate is laid on a mold and the varnish is used. Using either the hand lay-up method, the spray-up method, or the male type or the female type, in which multiple layers are laminated, the base material made of reinforcing fibers is impregnated with varnish and stacked to form, and pressure is applied to the molded product. Vacuum bag method in which a flexible mold that can be covered and airtightly sealed is vacuum (decompressed) molded, SMC press method in which a varnish containing reinforcing fibers is previously made into a sheet and compression molded with a mold, fibers Examples thereof include a method of producing a prepreg in which reinforcing fibers are impregnated with the varnish by an RTM method or the like in which the varnish is injected into a spread molding, and then baking the prepreg with a large autoclave. The fiber-reinforced resin molded product obtained above is a molded product having a reinforcing fiber and a cured product of an epoxy resin composition. Specifically, the amount of reinforcing fibers in the fiber-reinforced molded product is 40. It is preferably in the range of mass% to 70% by mass, and particularly preferably in the range of 50% by mass to 70% by mass from the viewpoint of strength.

9. Conductive Paste As a method for obtaining a conductive paste from the epoxy resin composition of the present invention, for example, a method of dispersing fine conductive particles in the curable resin composition can be mentioned. The conductive paste can be a paste resin composition for circuit connection or an anisotropic conductive adhesive depending on the type of fine conductive particles used.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, "parts" and "%" are based on mass unless otherwise specified. The GPC was measured under the following conditions.

<GPC measurement conditions>
Measuring device: "HLC-8320 GPC" manufactured by Tosoh Corporation,
Column: Guard column "HXL-L" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G3000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G4000HXL" manufactured by Tosoh Corporation
Detector: RI (Differential Refractometer)
Data processing: "GPC Workstation EcoSEC-WorkStation" manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Developing solvent tetrahydrofuran
Flow velocity 1.0 ml / min Standard: The following monodisperse polystyrene with a known molecular weight was used in accordance with the measurement manual of the above-mentioned "GPC workstation EcoSEC-WorkStation".
(Polystyrene used)
"A-500" manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation
"F-40" manufactured by Tosoh Corporation
"F-80" manufactured by Tosoh Corporation
"F-128" manufactured by Tosoh Corporation
Sample: A solution of 1.0% by mass in terms of resin solid content in tetrahydrofuran filtered with a microfilter (50 μl).

Example 1 Synthesis of Epoxy Resin (A-1) 900 g (6.0 mol) of p-terrary butylphenol and 18 g of oxalic acid are charged in a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractionation tube, and a stirrer. The mixture was stirred while raising the temperature from room temperature to 105 ° C. in 45 minutes. Subsequently, 43 g (0.6 mol) of a 42 mass% formalin aqueous solution was added dropwise over 2 hours. After completion of the dropping, the mixture was further stirred at 100 ° C. for 1 hour, and then the temperature was raised to 180 ° C. in 3 hours. After completion of the reaction, the water remaining in the reaction system and the unreacted material were removed under heating and reduced pressure to obtain a novolak resin (a-1). The hydroxyl group equivalent of the obtained novolak resin (a-1) was 156 g / equivalent.

A flask equipped with a thermometer, a cooling tube, and a stirrer was charged with 312 g of novolak resin (a-1), 1110 g (6.0 mol) of epichlorohydrin, and 330 g of n-butanol while purging with nitrogen gas to dissolve them. After the temperature was raised to 50 ° C., 440 g (2.20 mol) of a 20% aqueous sodium hydroxide solution was added over 3 hours, and then the reaction was further carried out at 50 ° C. for 1 hour. After completion of the reaction, unreacted epichlorohydrin was distilled off under reduced pressure at 150 ° C. Next, 300 g of methyl isobutyl ketone and 50 g of n-butanol were added to the obtained crude epoxy resin and dissolved. Further, 15 g of a 10 mass% sodium hydroxide aqueous solution was added to this solution and reacted at 80 ° C. for 2 hours, and then washing with 100 g of water was repeated 3 times until the pH of the washing solution became neutral. Next, the inside of the system was dehydrated by azeotrope, and after undergoing microfiltration, the solvent was distilled off under reduced pressure to obtain an epoxy resin (A-1). The epoxy equivalent of the obtained epoxy resin was 256 g / eq. The GPC chart of the obtained epoxy resin (A-1) is shown in FIG. The value of n in the structural formula (1) of the epoxy resin (A-1) was 0.05 , and the content of the compound represented by the structural formula (2) was 0.5%.

Example 2 Synthesis of Epoxy Resin (A-2) 900 g (6.0 mol) of p-terrary butylphenol and 18 g of oxalic acid are charged in a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractional tube, and a stirrer. The mixture was stirred while raising the temperature from room temperature to 98 ° C. in 45 minutes. Subsequently, 172 g (2.4 mol) of a 42 mass% formalin aqueous solution was added dropwise over 2 hours. After completion of the dropping, the mixture was further stirred at 98 ° C. for 12 hours, and then the temperature was raised to 180 ° C. in 3 hours. After completion of the reaction, the water remaining in the reaction system and the unreacted material were removed under heating and reduced pressure to obtain a novolak resin (a-2). The hydroxyl group equivalent of the obtained novolak resin (a-2) was 158 g / equivalent.

A flask equipped with a thermometer, a cooling tube, and a stirrer was charged with 316 g of novolak resin (a-2), 1110 g (6.0 mol) of epichlorohydrin, and 330 g of n-butanol while purging with nitrogen gas to dissolve them. After the temperature was raised to 50 ° C., 440 g (2.20 mol) of a 20% aqueous sodium hydroxide solution was added over 3 hours, and then the reaction was further carried out at 50 ° C. for 1 hour. After completion of the reaction, unreacted epichlorohydrin was distilled off under reduced pressure at 150 ° C. Next, 300 g of methyl isobutyl ketone and 50 g of n-butanol were added to the obtained crude epoxy resin and dissolved. Further, 15 g of a 10 mass% sodium hydroxide aqueous solution was added to this solution and reacted at 80 ° C. for 2 hours, and then washing with 100 g of water was repeated 3 times until the pH of the washing solution became neutral. Next, the inside of the system was dehydrated by azeotrope, and after undergoing microfiltration, the solvent was distilled off under reduced pressure to obtain an epoxy resin (A-2). The epoxy equivalent of the obtained epoxy resin was 298 g / eq. The GPC chart of the obtained epoxy resin (A-2) is shown in FIG. The value of n in the structural formula (1) of the epoxy resin (A-2) was 1.95 , and the content of the compound represented by the structural formula (2) was 1.4%.

Comparative Example 1 Synthesis of Epoxy Resin (A'-1) Epoxy Resin (A) was the same as in Synthesis Example 2 except that the novolak resin (a-1) was 2,2'-methylenebis (4-terriary butylphenol) 312 g. '-1) was obtained. The epoxy equivalent of the obtained epoxy resin (A'-1) is 235 g / eq, the value corresponding to n in the structural formula (1) of the epoxy resin (A'-1) is 0 , and it is represented by the structural formula (2). The content of the compound was 0%.

Comparative Example 2 Synthesis of Epoxy Resin (A'-2) Epoxy resin (A'-2) was obtained in the same manner as in Example 2 except that the 42 mass% formalin aqueous solution was changed to 215 g (3.0 mol). .. The epoxy equivalent of the obtained epoxy resin was 331 g / eq. The value of n in the structural formula (1) of the epoxy resin (A'-2) was 2.10 , and the content of the compound represented by the structural formula (2) was 2.4%.

<Preparation of composition and cured product>
After blending the following compounds with the compositions shown in Table 1, the target epoxy resin composition was prepared by melt-kneading at a temperature of 90 ° C. for 5 minutes using two rolls. The abbreviations in Table 1 mean the following compounds.
-Epoxy resin A-1: Epoxy resin obtained in Synthesis Example 1-Epoxy resin A-2: Epoxy resin obtained in Synthesis Example 2-Epoxy resin A'-1: Epoxy resin obtained in Comparative Synthesis Example 1. -Epoxy resin A'-2: Epoxy resin obtained in Comparative Synthesis Example 2-Curing agent TD-2131: Phenolic novolak resin hydroxyl group equivalent: 104 g / eq (manufactured by DIC Co., Ltd.)
・ TPP: Triphenylphosphine ・ Fused silica: Spherical silica "FB-560" manufactured by Denka Co., Ltd. ・ Silane coupling agent: γ-glycidoxytriethoxyxisilane "KBM-403" manufactured by Shinetsu Chemical Industry Co., Ltd. ・ Carnauba wax : "PEARL WAX No.1-P" manufactured by Denka Co., Ltd.

Next, the resin composition obtained by pulverizing the above-mentioned resin composition was obtained by using a transfer molding machine at a pressure of 70 kg / cm ² , a temperature of 175 ° C., and a time of 180 seconds to form a circle of φ50 mm × 3 (t) mm. It was formed into a plate and further cured at 180 ° C. for 5 hours.

<Measurement of glass transition temperature and thermal elastic modulus>
A cured product having a thickness of 0.8 mm was cut out to a size of 5 mm in width and 54 mm in length from the molded product produced above, and this was used as a test piece 1. This test piece 1 is stored at 260 ° C. using a viscoelasticity measuring device (DMA: solid viscoelasticity measuring device “RSAII” manufactured by Leometric Co., Ltd., rectangular tension method: frequency 1 Hz, heating rate 3 ° C./min). The rate was measured as the thermal elastic modulus.

<Measurement of shrinkage rate during molding>
Using a transfer molding machine (Kotaki Seiki Co., Ltd., KTS-15-1.5C), the resin composition was injection-molded under the conditions of a mold temperature of 150 ° C., a molding pressure of 9.8 MPa, and a curing time of 600 seconds. A test piece having a length of 110 mm, a width of 12.7 mm, and a thickness of 1.6 mm was prepared. After that, the test piece was post-cured at 175 ° C. for 5 hours, the inner diameter of the mold cavity and the outer diameter of the test piece at room temperature (25 ° C.) were measured, and the shrinkage rate was calculated by the following formula.
Shrinkage rate (%) = {(inner diameter dimension of mold)-(longitudinal dimension of cured product at 25 ° C)} / (inner diameter dimension of mold cavity at 175 ° C) x 100 (%)
These results are shown in Table 1.

Claims (13)

The following structural formula (1)

[In the structural formula (1), R ¹ , R ² , and R ³ are hydrogen atoms or alkyl groups having 4 to 8 carbon atoms, and at least one of them is an alkyl group having 4 to 8 carbon atoms. G is a glycidyl group , n indicates the number of repetitions, and the average value is 0.01 to 2.0, and R ¹ , R ² , and R ³ may be the same or different for each repetition. ] And the following structural formula (2)

[In structural formula (2), R ¹ , R ² , and R ³ are hydrogen atoms or alkyl groups having 4 to 8 carbon atoms, and at least one of them is an alkyl group having 4 to 8 carbon atoms, and G is It is a glycidyl group. ] Hints as essential components, a 0.1% to 2.0% content of an area ratio in GPC measurement of the structural formula (2), and its epoxy equivalent that it is a range of 245~330g / eq Epoxy resin as a feature. The epoxy resin according to claim 1 ^{, wherein R 1} in the structural formula (1) and the structural formula (2) is an alkyl group having 4 to 8 carbon atoms, and R ² and R ^{3 are hydrogen atoms.} The epoxy resin according to claim 1, wherein ^{R 1} in the structural formula (1) and the structural formula (2) is a t-butyl group, and R ² and R ^{3 are hydrogen atoms.} An epoxy resin composition containing the epoxy resin according to any one of claims 1 to 3 and a curing agent (B) as essential components. The epoxy resin composition according to claim 4, further comprising an epoxy resin (C) other than the epoxy resin according to any one of claims 1 to 3. A cured product of the epoxy resin composition according to claim 4 or 5. A semiconductor encapsulating material containing the epoxy resin composition according to claim 4 or 5 and an inorganic filler. A semiconductor device containing a cured product of the semiconductor encapsulating material according to claim 7. A prepreg which is a semi-cured product of an impregnated base material having the epoxy resin composition according to claim 4 or 5 and a reinforcing base material. A circuit board comprising a plate-shaped excipient of the epoxy resin composition according to claim 4 or 5 and a copper foil. A build-up film comprising a cured product of the epoxy resin composition according to claim 4 or 5 and a base film. A fiber-reinforced composite material containing the epoxy resin composition according to claim 4 or 5 and reinforcing fibers. A fiber-reinforced molded product which is a cured product of the fiber-reinforced composite material according to claim 12.

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