JP2020117607A - Epoxy resin composition and cured article thereof - Google Patents

Abstract

To provide a non-halogen frame retardant epoxy resin composition excellent in 600 V or higher tracking resistance in a cured article and a circuit board, and exhibiting high thermal conductance.SOLUTION: The epoxy resin composition is provided that includes: an epoxy resin; a hardener; and a filler, wherein the epoxy resin includes a phosphorus-containing epoxy resin obtained by reaction between a novolac-type epoxy resin having a specific molecular weight distribution and a phosphorus compound represented by the following formula (1). In the formula (1), R, Rare each independently a C1-20 hydrocarbon group which may have a hetero element, may be linear, branched chain-like, or cyclic, and may be formed into a cyclic structure by bonding Rto R, and n1, n2 are each independently 0 or 1.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to an insulating resin composition used for a printed circuit board (PCB), a resin composition having a non-halogen flame retardancy and a high thermal conductivity excellent in tracking resistance, and a cured product.

In recent years, printed circuit boards (PCBs) have been used in most electrical products, and their multifunction and high performance are rapidly increasing in other applications such as daily home electrical products, automobiles, and communication infrastructure equipment. It is progressing. Along with this, the density of the PCB circuit has also been increased, and the operating voltage has also increased, so that heat resistance and high insulation reliability of the circuit board are being further demanded. In particular, when electrical products are used in harsh environments such as high temperature and high humidity or in open atmosphere, dust, moisture, and contaminants tend to accumulate on the insulating surface of the board, which causes electrical sparks to reduce the insulation. While doing so, there is a safety problem such as destruction due to short circuit of the circuit and further combustion. With the miniaturization and weight reduction of circuit boards accompanying the high functionality of various devices, the pitch of circuit board wiring is becoming increasingly narrower, and there is a demand for improved insulation between circuits. Therefore, improvement of the tracking resistance (CTI) of the circuit board material is becoming an extremely important design in designing the circuit board.

On the other hand, due to the higher density of circuits and the increase in operating voltage, it is becoming important to take measures against heat from the substrate. Of course, the insulating material itself used for the substrate is also required to have high heat resistance, and one of the indicators is the glass transition temperature (Tg) of the cured product. In recent years, circuit density has been increasing, and in order to ensure reliability, it has become more common to apply heat resistance higher than that of glass/epoxy (FR-4) substrates, and another measure against heat is accumulation of heat generated by electronic components. In order to prevent the above, measures to positively release heat have been taken, and measures to dissipate heat by joining with a metal substrate have been taken. In that case, even in the insulating material itself, measures are taken to compensate for heat dissipation by incorporating an inorganic filler (filler) having excellent thermal conductivity into the composition.

Further, such a circuit board is endowed with heat resistance and flame retardancy, and it has already become a matter of course that the flame retardance satisfies the V-0 standard. In consideration of environmental issues, flame retardance here is generally performed by using a non-halogen flame retardant that does not use a brominated flame retardant that may generate a harmful gas during combustion.

Many boards use phosphorus-containing epoxy resin to obtain flame retardancy of circuit boards. However, the phosphorus flame-retardant mechanism, which is generally called non-halo substrate, forms a non-combustible carbon layer by polyphosphoric acid coating. However, the tracking resistance of the substrate remains at about 225V. A method using an inorganic filler has been proposed as a method for supplementing the flame retardancy of phosphorus. As the inorganic filler here, hydratable aluminum hydroxide is generally used, but the thermal decomposition temperature is low and the heat resistance of the cured product is greatly reduced. Patent Document 1 discloses a method in which dicyandiamide, which is a curing agent, is used in combination with an aromatic amine, and a method in which boehmite or barium sulfate is used as an inorganic filler to obtain flame retardancy while maintaining solder heat resistance. There is. However, the amount of the inorganic filler that can be used is limited in terms of the viscosity of the varnish in the production of the prepreg in the substrate production process. On the other hand, in order to maintain heat conduction, it is necessary to use a large amount of an inorganic filler having a high heat conductivity separately, so that it is very difficult to provide a composition that can satisfy these characteristics at the same time.

Further, in Patent Document 2, a non-halogen flame-retardant resin composition contains 5 to 85% of a high thermal conductive filler such as alumina, magnesium oxide, aluminum nitride, or boron nitride for the purpose of imparting thermal conductivity to a circuit board. The method of making it public is open. However, the amount of the high thermal conductive filler with respect to the entire composition described in the examples is as large as 65 to 80%, and in exchange for reducing the phosphorus content to improve the tracking resistance, the purpose of imparting flame retardancy is There was no room for new fillers.

JP, 2016-3335, A JP, 2010-155981, A

The problem to be solved by the present invention is to provide an epoxy resin composition which exhibits high thermal conductivity excellent in tracking resistance of 600 V or more in a cured product of a halogen-free flame-retardant epoxy resin composition or a circuit board. It is in.

In order to solve the above-mentioned problems, the present inventors have diligently studied synthetic raw materials in a phosphorus-containing epoxy resin to be blended, and directly reacting and bonding an active hydrogen atom of a phosphorus compound with a novolac type epoxy resin having a specific molecular weight distribution. We have found that phosphorus-containing epoxy resin has superior flame retardancy, and completed a composition that can provide a circuit board that has both heat resistance and thermal conductivity and excellent tracking resistance. ..

That is, the present invention is an epoxy resin composition containing an epoxy resin, a curing agent, and a filler, wherein the epoxy resin has a binuclear content of 15 area% or less in gel permeation chromatography (GPC) measurement. Obtained by reacting a novolac type epoxy resin having a trinuclear content of 15 to 60 area% and a number average molecular weight of 350 to 700 with a molecular weight distribution with a phosphorus compound represented by the following formula (1). An epoxy resin composition comprising the phosphorus-containing epoxy resin.

式（１）において、Ｒ^１、Ｒ^２はそれぞれ独立に、ヘテロ元素を有してもよい炭素数１〜２０の炭化水素基を示し、直鎖状、分岐鎖状、環状であってもよく、またＲ^１とＲ^２が結合して環状構造を形成してもよい。ｎ１、ｎ２はそれぞれ独立に、０又は１である。

In the formula (1), R ¹ and R ² each independently represent a hydrocarbon group having 1 to 20 carbon atoms which may have a hetero element, and may be linear, branched or cyclic. Alternatively, R ¹ and R ² may combine to form a cyclic structure. n1 and n2 are 0 or 1 each independently.

The GPC measurement conditions are as follows.
Tosoh Corporation columns (TSKgelG4000H _XL , TSKgelG3000H _XL , TSKgelG2000H _XL ) were used in series, and the column temperature was 40°C. Further, tetrahydrofuran was used as the eluent, the flow rate was 1 mL/min, and the detector was an RI (differential refractometer) detector. 0.1 g of the sample was dissolved in 10 mL of tetrahydrofuran to give a measurement sample. The binuclear body content rate and the trinuclear body content rate were calculated from the obtained chromatogram, and the number average molecular weight was determined from a calibration curve based on standard polystyrene.

The phosphorus content of the phosphorus-containing epoxy resin is preferably 0.8 to 5.5 mass%, and the phosphorus content of the epoxy resin composition is 0.3 to 4.0 mass as the resin component excluding the inorganic component. % Is preferred.

The epoxy resin has an epoxy equivalent of 100 to 300 g/eq. It is preferable to include the phosphorus-free epoxy resin.

The active hydrogen group of the curing agent is preferably 0.3 to 2.0 mol with respect to 1 mol of the epoxy group of the epoxy resin.

The blending amount of the filler is preferably 50 to 400 parts by mass with respect to 100 parts by mass of the epoxy resin.

The filler is preferably a general-purpose filler having a thermal conductivity of less than 20 W/m·K and a high thermal-conductivity filler having a thermal conductivity of 20 W/m·K or more, and a ratio of the general-purpose filler and the high-thermal conductivity filler. Is preferably 15/85 to 30/70 (mass ratio).

The general-purpose filler is preferably silica, titanium oxide, aluminum hydroxide, magnesium hydroxide, or calcium carbonate, and the high thermal conductivity filler is preferably metal nitride, metal oxide, carbide, corundum, or aluminum powder.

The epoxy resin composition preferably further contains a coupling agent in an amount of 0.1 to 3 parts by mass with respect to 100 parts by mass of the epoxy resin.

Further, the present invention is a cured product obtained by curing the epoxy resin composition, which is a prepreg, an adhesive sheet, and a laminated plate using the epoxy resin composition.

Epoxy resin composition of the present invention resin composition is not only excellent in heat resistance and flame retardancy, but since it does not use a halogen-based flame retardant, environment that does not generate harmful or corrosive gas during combustion It is also a friendly material. Furthermore, since the epoxy resin used reduces the amount of the binuclear component that deteriorates heat resistance and flame retardancy by controlling the molecular weight compared to conventional epoxy resins, the phosphorus content itself can also be reduced. Therefore, tracking resistance is also improved. In addition, the amount of general-purpose fillers used as flame retardant aids to be used together can be reduced, and thus the blending ratio of the filler having high thermal conductivity can be increased.
A glass cloth is impregnated with this epoxy resin composition to form a high heat conductive prepreg or a high heat conductive coating by a coating process, and then used as an insulating layer on a printed circuit board (PCB). Since it is possible to provide the thermal conductivity that dissipates the generated heat more rapidly than in the past, it is possible to further improve the durability and stability of the electronic component on the PCB.

3 is a GPC chart of a novolac type epoxy resin obtained in Synthesis Example 2.

Embodiments of the present invention will be described below.

The phosphorus-containing epoxy resin used in the epoxy resin composition of the present invention has a specific molecular weight distribution depending on the origin. The novolac type epoxy resin used as a raw material of the phosphorus-containing epoxy resin has a binuclear body content of 15 area% or less in GPC measurement, preferably 5 to 12 area %. By containing a small amount of binuclear body, physical properties such as adhesive strength are improved. Further, the trinuclear body content is 15 to 60 area %, preferably 20 to 60 area %, more preferably 30 to 58 area %, further preferably 35 to 55 area %.
The number average molecular weight is 350 to 700, preferably 380 to 600. When the number average molecular weight exceeds 700, the viscosity of the obtained phosphorus-containing epoxy resin becomes high, which may adversely affect workability and substrate impregnation property.

When the binuclear content in GPC measurement exceeds 15% by area, the flame retardancy of the epoxy resin composition becomes insufficient, and it is necessary to increase the phosphorus content in the epoxy resin composition in order to develop the flame retardancy. There is. However, if the phosphorus content is increased, there is a possibility that sufficient tracking resistance of 600 V or more cannot be obtained. Further, since the epoxy equivalent becomes high, sufficient heat resistance may not be obtained.

Even if the binuclear content in the GPC measurement is 15 area% or less, if the trinuclear content is less than 15 area%, the viscosity of the composition containing the filler is significantly increased because the components of the tetranuclear or more are increased, The workability in producing a laminated plate is remarkably deteriorated, and the yield is often deteriorated due to poor impregnation into a glass cloth. When the trinuclear body content exceeds 60% by area, the components of tetranuclear bodies or more are reduced, so that the crosslink density of the cured product may be lowered and the heat resistance may be deteriorated.

The content of the pentanuclear compound or more is preferably 45 area% or less, more preferably 40 area% or less. When the content of the pentanuclear compound is 45 area% or less, a cured product having higher adhesive strength can be obtained.

The phosphorus-containing epoxy resin is obtained by binding the phosphorus compound represented by the formula (1) to the epoxy group of the novolac type epoxy resin having such a molecular weight distribution by an addition reaction. The reason why the flame retardancy of the phosphorus-containing epoxy resin obtained in this way is improved is that the elastic modulus of the obtained cured product becomes low, the char generated during combustion becomes stronger, and a higher heat insulating effect is obtained. It is supposed to bring it, but it has not been verified. The phosphorus-containing epoxy resin may be referred to as "the phosphorus-containing epoxy resin of the present invention".
In order to obtain desired tracking characteristics and sufficient flame retardancy, the phosphorus-containing epoxy resin having a specific molecular weight distribution and a phosphorus content of 0.8 to 5.5 mass% is used, and The phosphorus content of the epoxy resin composition obtained by mixing a curing agent, a filler and the like in the contained epoxy resin is preferably 0.3 to 4.0% by mass as the solid content excluding the filler, and 0.4 to 3.0. Mass% is more preferable, and 0.5 to 2.5 mass% is particularly preferable.

The novolak type epoxy resin having a specific molecular weight distribution is obtained by reacting a novolac resin having a specific molecular weight distribution with epihalohydrin. Novolac resins are reaction products of phenols and aldehydes. Examples of phenols used to obtain the novolac resin include phenol, cresol, ethylphenol, butylphenol, styrenated phenol, cumylphenol, naphthol, catechol, resorcinol, naphthalenediol, and bisphenol A. Include formalin, formaldehyde, hydroxybenzaldehyde, salicylaldehyde and the like. Further, an aralkylphenol resin using xylylene dimethanol, xylylene dichloride, bischloromethylnaphthalene, bischloromethyl biphenyl or the like instead of aldehydes can also be used as the novolac resin of the novolac type epoxy resin raw material of the present invention.

In order to obtain an epoxy resin having a specific molecular weight distribution, adjusting the molar ratio of phenols and aldehydes and epoxidizing the novolak resin obtained by the method of removing low molecular weight components from the resulting novolak resin Can be obtained at. Moreover, you may epoxidize the novolak resin obtained by the manufacturing method described in Unexamined-Japanese-Patent No. 2002-194041 and 2007-126683.

The molar ratio of phenols to aldehydes is indicated by the molar ratio of phenols to 1 mol of aldehydes (phenols/aldehydes), and is produced at a ratio of 1 or more. It is preferably 3.0 to 6.0. When the molar ratio is large, a large amount of binuclear and trinuclear bodies are produced, and when the molar ratio is small, a large amount of high molecular weight bodies are formed and the amount of dinuclear and trinuclear bodies is small.

The novolac resin is represented by the following formula (2). In the present specification, a binuclear body is a case where k in the formula (2) is 0, and a trinuclear body is a case where k is 1. That is, the n-nuclear body means a structure in which k in the formula (2) is n−2, in other words, a structure in which n=k+2.

式（２）において、Ａはそれぞれ独立に、ベンゼン環、ナフタレン環、ビスフェノール構造等の芳香族環基であり、これらの芳香族環基は置換基を有してもよい。Ｘは２価の結合基であり、アルデヒド類やキシリレンジクロライド等の縮合剤の残基である。ｍは１又は２である。ｋは繰返し数であって、０以上の数を示し、その平均値は０．５〜５である。

In the formula (2), each A independently represents an aromatic ring group such as a benzene ring, a naphthalene ring, and a bisphenol structure, and these aromatic ring groups may have a substituent. X is a divalent linking group, which is a residue of a condensing agent such as aldehydes and xylylene dichloride. m is 1 or 2. k is the number of repetitions and indicates a number of 0 or more, and the average value thereof is 0.5 to 5.

In order to obtain a novolak resin having a specific molecular weight distribution, a method for removing the binuclear body from the resulting novolak resin by utilizing the solubility difference of various solvents, or a method for dissolving the binuclear body in an alkaline aqueous solution to remove it It can be obtained by a method or the like. Alternatively, any other known separation method may be used.

A novolak type epoxy resin having a specific molecular weight distribution can be obtained by using a known epoxidation method for the thus-obtained molecular weight-controlled novolak resin. Further, a novolac type epoxy resin having a specific molecular weight distribution can be obtained by removing the binuclear component from a commercially available novolac type epoxy resin by various methods.

The novolac type epoxy resin thus obtained is represented by the following formula (3). In the present specification, a binuclear body is a case where i in the formula (3) is 0, and a trinuclear body is a case where i is 1. That is, the n-nuclear body means a structure in which i in the formula (3) is n−2, in other words, a structure in which n=i+2.

式（３）において、Ａ、Ｘ、及びｍは前記式（２）のＡ、Ｘ、及びｍとそれぞれ同義である。Ｇは下記式（４）で表されるグリシジルオキシ基である。ｉは繰返し数であって、０以上の数を示し、その平均値は０．５〜５である。

In the formula (3), A, X, and m have the same meanings as A, X, and m in the formula (2). G is a glycidyloxy group represented by the following formula (4). i is the number of repetitions and indicates a number of 0 or more, and the average value thereof is 0.5 to 5.

Examples of the phosphorus compound represented by the formula (1) include dimethylphosphine, diethylphosphine, diphenylphosphine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (for example, HCA (Sanko). Etc.), dimethylphosphine oxide, diethylphosphine oxide, dibutylphosphine oxide, diphenylphosphine oxide, 1,4-cyclooctylenephosphine oxide, 1,5-cyclooctylenephosphine oxide (for example, CPHO (Nippon Kagaku Kogyo) Etc.) and the like. These phosphorus compounds may be used alone or in combination of two or more.

The phosphorus compound represented by the formula (1) is bonded to the epoxy resin by an addition reaction with the epoxy group of the epoxy resin as shown in the following reaction formula. The blending amount of the phosphorus compound can be calculated by the phosphorus content of the required phosphorus-containing epoxy resin. The phosphorus compound represented by the formula (1) is preferably blended so that the active group of the phosphorus compound is in the range of 0.04 to 0.5 mol with respect to 1 mol of the epoxy group of the epoxy resin. The P—H bond of the phosphorus compound is an active hydrogen group and reacts with the epoxy group to form P—CH ₂ —CH(OH)—.

The phosphorus-containing epoxy resin obtained by such a reaction is represented by the following formula (5). The reaction product is the phosphorus-containing epoxy resin represented by the formula (5), but usually the unreacted raw material novolac type epoxy resin represented by the formula (3) also remains, so that it is obtained as a mixture thereof. .. The raw material novolac type epoxy resin may be removed from the mixture, and the phosphorus-containing epoxy resin represented by the formula (5) may be isolated and used. Further, the isolated phosphorus-containing epoxy resin may be used in combination with an epoxy resin other than the raw material novolac type epoxy resin.

式（５）において、Ａ、Ｘ、ｍ、及びｉは前記式（２）、（３）のＡ、Ｘ、ｍ、及びｉとそれぞれ同義である。Ｚはそれぞれ独立に下記式（６）で表されるリン含有基又はグリシジルオキシ基であるが、全部のＺがいずれか一方の基であることはなく、下記式（６）で表されるリン含有基とグリシジルオキシ基とをそれぞれ少なくとも一つは含む。

In the formula (5), A, X, m, and i have the same meanings as A, X, m, and i in the formulas (2) and (3), respectively. Each Z is independently a phosphorus-containing group or a glycidyloxy group represented by the following formula (6), but not all Zs are either groups, and a phosphorus represented by the following formula (6) At least one containing group and at least one glycidyloxy group are included.

式（６）において、Ｒ^１、Ｒ^２、ｎ１、及びｎ２は前記式（１）のＲ^１、Ｒ^２、ｎ１、及びｎ２とそれぞれ同義である。

In the formula ^{(6), R 1, R} 2, n1, and n2 are the same meanings as ^{R 1, R 2, n1,} and n2 in the formula (1).

As the epoxy resin used in the epoxy resin composition of the present invention, the above-mentioned phosphorus-containing epoxy resin may be used alone or, if necessary, one kind or two or more kinds of various epoxy resins may be used in combination. The various epoxy resins may be phosphorus-containing epoxy resins other than the phosphorus-containing epoxy resins or phosphorus-free epoxy resins. When these epoxy resins are used in combination, it is preferably 50% by mass or less and more preferably 35% by mass or less based on the total amount of the epoxy resins. If the amount of the epoxy resin used in combination is too large, the properties of the epoxy resin composition may deteriorate.

As the phosphorus-free epoxy resin that can be used together, conventionally known epoxy resins can be used. The epoxy resin refers to an epoxy resin having at least one epoxy group, but an epoxy resin having two or more epoxy groups is preferable, and an epoxy resin having three or more epoxy groups is more preferable. Specific examples include polyglycidyl ether compounds, polyglycidyl amine compounds, polyglycidyl ester compounds, alicyclic epoxy compounds, and other modified epoxy resins. The epoxy equivalent of these phosphorus-free epoxy resins is 100 to 300 g/eq. Is preferred. If the epoxy equivalent exceeds 300, the viscosity of the epoxy resin may be too high.

Examples of the polyglycidyl ether compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetramethylbisphenol F type epoxy resin, biphenol type epoxy resin, hydroquinone type epoxy resin, bisphenol fluorene type epoxy resin, bisphenol S type epoxy resin. , Diphenyl sulfide type epoxy resin, diphenyl ether type epoxy resin, resorcinol type epoxy resin, naphthalene diol type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alkyl novolac type epoxy resin, aromatic modified phenol novolac type epoxy resin, Bisphenol novolac type epoxy resin, naphthol novolac type epoxy resin, β-naphthol aralkyl type epoxy resin, naphthalenediol aralkyl type epoxy resin, α-naphthol aralkyl type epoxy resin, biphenylaralkylphenol type epoxy resin, trihydroxyphenylmethane type epoxy resin, Examples thereof include tetrahydroxyphenylethane type epoxy resin, dicyclopentadiene type epoxy resin, alkylene glycol type epoxy resin, and aliphatic cyclic epoxy resin.

Examples of the polyglycidyl amine compound include diaminodiphenylmethane type epoxy resin, metaxylene diamine type epoxy resin, 1,3-bisaminomethylcyclohexane type epoxy resin, isocyanurate type epoxy resin, aniline type epoxy resin, hydantoin type epoxy resin, Examples thereof include aminophenol type epoxy resins.

Examples of the polyglycidyl ester compound include dimer acid type epoxy resins, hexahydrophthalic acid type epoxy resins, trimellitic acid type epoxy resins, and the like.

Examples of the alicyclic epoxy compound include epoxy resins having an alicyclic structure such as Celoxide 2021 (manufactured by Daicel Chemical Industries, Ltd.).

Other modified epoxy resins include, for example, urethane modified epoxy resin, oxazolidone ring-containing epoxy resin, epoxy modified polybutadiene rubber derivative, carboxyl group terminated butadiene nitrile rubber (CTBN) modified epoxy resin, polyvinylarene polyoxide (for example, divinylbenzene dioxide). , Trivinylnaphthalene trioxide, etc.), phenoxy resin and the like.

Further, as the phosphorus-containing epoxy resin other than the phosphorus-containing epoxy resin used in the epoxy resin composition of the present invention, not the phosphorus compound represented by the formula (1) but an addition reaction of the epoxy resin and the phosphorus-containing phenol compound. The obtained epoxy resin etc. are mentioned.

Examples of the phosphorus-containing phenol compound include 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,7-dihydroxy-1-naphthyl)-. 10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(1,4-dihydroxy-2-naphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphinyl Hydroquinone, diphenylphosphenyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, 1,5-cyclooctylenephosphinyl-1,4-phenyldiol, etc. Are listed. These phosphorus-containing phenol compounds may be used alone or in combination of two or more.
Moreover, you may mix and use these phosphorus-containing phenol compounds and the phosphorus compound represented by said Formula (1). When mixed and used, a phosphorus-containing epoxy resin having a structure different from that of the phosphorus-containing epoxy resin represented by the above formula (5) can be obtained, but can be mixed and used unless the effects of the present invention are impaired.

As the curing agent used in the epoxy resin composition of the present invention, any general curing agent for epoxy resin can be used. Specific examples include various amines such as dicyandiamide, aromatic amines and aliphatic amines, acid anhydrides, polyfunctional phenol compounds, polythiol compounds, isocyanate compounds, blocked isocyanate compounds, and alkyd resins. Among these curing agents, acid anhydrides, dicyandiamide, various amines, and polyfunctional phenol compounds are preferable for obtaining the characteristics. These curing agents may be used alone or in combination of two or more kinds.

The curing agent is preferably blended so that the active group of the curing agent is in the range of 0.3 to 2.0 mol with respect to 1 mol of the epoxy group of the epoxy resin. In the case of phenolic resin, acid anhydrides and amines, the range of 0.8 to 1.2 mol is more preferable, and in the case of dicyandiamide, the range of 0.4 to 0.6 mol is more preferable. If the amount of the curing agent used is less than 0.3 mol, the heat resistance and flame retardancy of the cured product will be significantly reduced. If it exceeds 2.0 mol, the heat resistance and flame retardancy are similarly reduced. Furthermore, when acid anhydrides or phenolamines are used, it is necessary to increase the curing catalyst, which may reduce the storage stability of the prepreg. Further, when dicyandiamide is used, the securing of the gel time in the B stage is greatly impaired, and voids may occur during molding of the laminated plate or defective adhesion of the copper foil may occur.

Examples of the acid anhydrides include styrene maleic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic dianhydride, phthalic anhydride, trimellitic anhydride, and methyl nadic acid. Anhydride, dodecenyl succinic anhydride, chlorendic anhydride, benzenetetracarboxylic anhydride, benzophenone tetracarboxylic dianhydride, ethylene bis (trimellitic anhydride), methylcyclohexenyl tetracarboxylic dianhydride, trimellitic acid Examples thereof include anhydrides and polyazelaic acid polyanhydrides.

Examples of the amines include aliphatic amine compounds such as diethylenetriamine, diethyltoluenediamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, ethylenediamine, isophoronediamine, and bis(4-amino-3-methylcyclohex). Alicyclic amine compounds such as methane and bis(4-aminocyclohexyl)methane, phenylenebis(methylamine), methylenedianiline, sulfonyldianiline, phenylenediamine, metaxylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenylether Aromatic amine compounds such as 4,4′-methylenebis(2-methyl-6-ethylaniline), dicyandiamide, and polyamide polyamines that are condensation products of polycarboxylic acids such as dimer acid and polyamines. ..

Examples of polyfunctional phenol compounds include bisphenol A, bisphenol F, bisphenol AD, bisphenol C, bisphenol K, bisphenol Z, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol S, tetramethylbisphenol Z. , Dihydroxydiphenyl sulfide, dihydroxydiphenyl ether, dihydroxystilbenes, bisphenols such as 4,4′-thiobis(3-methyl-6-t-butylphenol), biphenols such as biphenol and tetramethylbiphenol, catechol, resorcin, Dihydroxybenzenes such as methylresorcin, hydroquinone, monomethylhydroquinone, dimethylhydroquinone, trimethylhydroquinone, mono-t-butylhydroquinone, di-t-butylhydroquinone, and hydroxy such as dihydroxynaphthalene, dihydroxymethylnaphthalene, dihydroxymethylnaphthalene, and trihydroxynaphthalene. Various kinds of naphthalene, phenol novolac resin, cresol novolac resin, bisphenol A novolac resin, dicyclopentadiene phenol resin, phenol aralkyl resin, naphthol novolac resin, naphthol aralkyl resin, terpene phenol resin, heavy oil modified phenol resin, etc. Phenols (eg, phenol, cresol, xylenol, butylphenol, amylphenol, nonylphenol, butylmethylphenol, trimethylphenol, phenylphenol, naphthol, bisphenol A, etc.) and various aldehydes (eg, formaldehyde, acetaldehyde, propylaldehyde, butyl) Aldehyde, valeraldehyde, capronaldehyde, benzaldehyde, chloraldehyde, bromaldehyde, hydroxybenzaldehyde, crotonaldehyde, glyoxal, etc. and various condensing agents (eg, dicyclopentadiene, xylylene glycol, bis(methylol)biphenyl, bis(chloro). Examples thereof include a phenol resin obtained by a condensation reaction with (methyl)biphenyl and the like).

The compounding amount of the filler used in the epoxy resin composition of the present invention is preferably 50 to 400 parts by mass, more preferably 100 to 380 parts by mass, and further preferably 150 to 300 parts by mass with respect to 100 parts by mass of the epoxy resin. preferable. Further, the filler is classified into a general-purpose filler having a thermal conductivity of less than 10 W/m·K and a high thermal conductivity filler having a thermal conductivity of 10 W/m·K or more. The content ratio of the general-purpose filler and the high thermal conductive filler in the filler (general-purpose filler/high thermal conductive filler) is preferably 15/85 to 30/70 (mass ratio). When the amount is less than 50 parts by mass relative to 100 parts by mass of the epoxy resin, the expansion coefficient and water absorption rate after curing are increased, and sufficient thermal conductivity cannot be obtained even if a large amount of high thermal conductivity filler is used. When it exceeds 400 parts by mass, the viscosity of the epoxy resin composition is remarkably increased and the impregnating moldability is greatly impaired. Further, the general-purpose filler mainly has a large element like a flame retardant aid, and if it is less than 15 mass ratio, it becomes difficult to adjust the balance with the phosphorus content in the epoxy composition to obtain flame retardancy. If it is more than 30 mass ratio, the content of the high thermal conductive filler is reduced, so that the cured product may not be sufficiently reduced in thermal expansion coefficient and the thermal conductivity and strength may not be improved.

Examples of the general-purpose filler include aluminum hydroxide, magnesium hydroxide, zinc borate, zinc carbonate, barium sulfate, hydrotalcite, dawsonite, silica, fumed silica and the like, which may be used alone or as a mixture of two or more kinds. May be. Examples of the mixture include a mixture of aluminum hydroxide and magnesium hydroxide, a mixture of silica, glass powder and kaolin.

Examples of the high thermal conductivity filler include metal nitride, metal oxide, carbide, and aluminum powder. Examples of the metal nitride include aluminum nitride, boron nitride, silicon nitride, etc., examples of the metal oxide include aluminum oxide, magnesium oxide, beryllia, zinc oxide, etc., and examples of the carbide include silicon carbide, boron carbide, etc. Are listed. These may be used alone or as a mixture of two or more kinds. Among these high thermal conductive fillers, aluminum oxide, magnesium oxide, zinc oxide, boron nitride, aluminum nitride, silicon nitride, and silicon carbide are preferable, and aluminum oxide and boron nitride are more preferable because of their low dielectric constant and hardness. In addition, a natural mineral such as corundum may be used.

It is preferable to adjust the particle size of the filler so as not to impair the workability of using the epoxy resin composition. The average particle diameter (D50) of these fillers is preferably 0.05 to 140 μm, more preferably 0.1 to 100 μm, and even more preferably 0.5 to 70 μm. Furthermore, it is necessary to adjust the combination of the sizes in consideration of the specific gravity of the filler to be combined. For example, by selecting the type having the smallest particle size for silica having a light specific gravity and selecting the type having a large particle size for aluminum oxide having a large specific gravity, the composition after curing due to the sedimentation of the filler in the epoxy resin composition Bias can be prevented.

Further, as the filler, along with the granular filler, in order to improve the toughness and strength of the cured product, a fiber filler (for example, glass fiber, alumina fiber, carbon fiber, etc.) or an organic filler (for example, rubber, thermoplastic elastic body, etc.) Fine particles).

A coupling agent may be used in the epoxy resin composition of the present invention. Examples of coupling agents that can be used include silane coupling agents and titanate coupling agents. The use of coupling agents improves the bonding performance between fillers and reinforcing materials such as woven glass cloth and improves the mechanical properties after curing. Further, it is also effective in uniformly dispersing the filler. The amount of the coupling agent blended is preferably 0.1 to 3 parts by mass, and more preferably 0.2 to 2 parts by mass, relative to 100 parts by mass of the epoxy resin. If the amount of the coupling agent is less than 0.1 parts by mass, the dispersibility of the filler may be deteriorated, and uniform mechanical strength, flame retardancy, tracking resistance, and high thermal conductivity in the cured product may not be obtained. If it exceeds 3 parts by mass, the heat resistance of the cured product and the aforementioned properties may be deteriorated.

The coupling agent, in order to improve the interfacial affinity between the resin and the filler, the coupling agent is added directly to the epoxy resin composition, or the filler is pre-surface treated with the coupling agent, and then the epoxy resin is added. The method used for the resin composition is used. Other additives are used depending on the desired physical properties, electrical properties, thermal properties, and light stability of the desired PCB, or by a method of compounding and using when forming an epoxy resin composition.

Examples of the silane coupling agent include epoxy silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Or γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ- Aminosilane coupling agents such as ureidopropyltriethoxysilane, mercaptosilane coupling agents such as 3-mercaptopropyltrimethoxysilane, p-styryltrimethoxysilane, vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, vinyl Examples thereof include vinylsilane coupling agents such as trimethoxysilane, vinyltriethoxysilane, and γ-methacryloxypropyltrimethoxysilane, and epoxy-based, amino-based, vinyl-based polymer type silane coupling agents.

Examples of titanate coupling agents include isopropyltriisostearoyl titanate, isopropyltri(N-aminoethylaminoethyl)titanate, diisopropylbis(dioctylphosphate)titanate, tetraisopropylbis(dioctylphosphite)titanate, tetraoctylbis( Ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite titanate, bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate and the like. To be

Further, a curing accelerator may be used in the epoxy resin composition of the present invention. Examples of the curing accelerator that can be used include imidazoles, tertiary amines and salts thereof, quaternary ammonium compounds, phosphorus compounds such as phosphines, metal compounds, Lewis acids, amine complex salts and the like. These curing accelerators may be used alone or in combination of two or more.

The imidazoles are not particularly limited as long as they are compounds having an imidazole skeleton. For example, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, bis-2-ethyl-4-methylimidazole, 1-methyl-2-ethylimidazole, 2-isopropylimidazole, 2,4- Alkyl-substituted imidazole compounds such as dimethylimidazole and 2-heptadecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-ethylimidazole, 1- Aryl groups such as benzyl-2-phenylimidazole, benzimidazole, 2-ethyl-4-methyl-1-(2'-cyanoethyl)imidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole And an imidazole compound substituted with a hydrocarbon group having a ring structure such as an aralkyl group.

Examples of the tertiary amines include 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-(dimethylaminomethyl)phenol, 1,8-diaza-bicyclo[5.4.0]-7-undecene( DBU) and the like.

Examples of the phosphines include triphenylphosphine, tricyclohexylphosphine, triphenylphosphine triphenylborane, tris(4-methylphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(2,6-dimethoxyphenyl)phosphine. Etc.

Examples of the metal compound include tin octylate.

Examples of the amine complex salt include boron trifluoride monoethylamine complex, boron trifluoride diethylamine complex, boron trifluoride isopropylamine complex, boron trifluoride chlorophenylamine complex, boron trifluoride benzylamine complex, boron trifluoride. Examples include aniline complexes, boron trifluoride complexes such as mixtures thereof, and the like.

Of these curing accelerators, when used as a build-up material application or a circuit board application, 2-dimethylaminopyridine, 4-dimethylaminopyridine, or 4-dimethylaminopyridine is preferred because of their excellent heat resistance, electrical characteristics, solder resistance, and the like. Imidazoles are preferred.

The amount of the curing accelerator may be appropriately selected according to the purpose of use, but 0.002 to 15 parts by mass is used as necessary, relative to 100 parts by mass of the epoxy resin component in the resin composition, 0.01 to 10 parts by mass is preferable, 0.05 to 8 parts by mass is more preferable, and 0.1 to 5 parts by mass is further preferable. By using the curing accelerator, the curing temperature can be lowered and the curing time can be shortened.

In addition, various known flame retardants can be used in the epoxy resin composition for the purpose of improving the flame retardancy of the obtained cured product, as long as the reliability is not deteriorated. Examples of flame retardants that can be used include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, organic metal salt flame retardants, and the like. From the viewpoint of the environment, phosphorus-based flame retardants are preferable. These flame retardants may be used alone, two or more of the same flame retardants may be used in combination, or different flame retardants may be used in combination.

Further, the epoxy resin composition, if necessary, within a range that does not impair the characteristics, a filler, a reinforcing filler, a plasticizer, a thermoplastic resin, a release agent, a defoaming agent, an emulsifier, a thixotropic agent, Other additives such as a leveling agent, a dispersant, an antioxidant, a heat stabilizer, a light stabilizer, a pigment and a dye can be added.

Examples of the bulking filler and the reinforcing filler include bulking agents such as calcium carbonate, talc, and clay, wollastonite, xonotlite, potassium titanate, aluminum borate, gypsum fiber, aramid fiber, carbon fiber, glass fiber, talc. , Reinforcing materials such as mica, glass flakes, and polymer whiskers.

Examples of the plasticizer include various rubber fine particles and thermoplastic elastomers. Examples of the dispersant include low molecular weight acidic polyester and long-chain adipic acid alcohol. Examples of antioxidants include dilauryl thiodipropionate and ditertiarybutylhydroxyltoluene. Examples of the heat and/or light stabilizer include benzophenone.

Further, in the resin composition of the present invention, an organic solvent or a reactive diluent can be used for adjusting the viscosity. These organic solvents or reactive diluents may be used alone or in combination of two or more.

Examples of the organic solvent include amides such as N,N-dimethylformamide and N,N-dimethylacetamide, dioxane, tetrahydrofuran, ethylene glycol monomethyl ether, dimethoxydiethylene glycol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, and triethylene glycol. Ethers such as dimethyl ether, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, methanol, ethanol, 1-methoxy-2-propanol, 2-ethyl-1-hexanol, benzyl alcohol, ethylene glycol, propylene glycol Alcohols such as butyl diglycol and pine oil, ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, cellosolve acetate, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, carbitol acetate, benzyl alcohol acetate, etc. Acetate esters, benzoic acid esters such as methyl benzoate and ethyl benzoate, cellosolves such as methyl cellosolve, cellosolve and butyl cellosolve, carbitols such as methyl carbitol, carbitol and butyl carbitol, and benzene. , Aromatic hydrocarbons such as toluene and xylene, sulfoxides such as dimethyl sulfoxide, alkanes such as hexane and cyclohexane, acetonitrile, N-methylpyrrolidone and the like.

Examples of the reactive diluent include monofunctional glycidyl ethers such as allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and tolyl glycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether. , 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, propylene glycol diglycidyl ether, and other bifunctional glycidyl ethers, glycerol polyglycidyl ether, trimethylolpropane Polyfunctional glycidyl ethers such as polyglycidyl ether, trimethylolethane polyglycidyl ether, pentaerythritol polyglycidyl ether, glycidyl esters such as neodecanoic acid glycidyl ester, and glycidyl amines such as phenyldiglycidylamine and tolyldiglycidylamine. Are listed.

These organic solvents or reactive diluents are preferably used in an amount of 90% by mass or less as the nonvolatile content in the epoxy composition containing a filler, and the appropriate type and amount thereof are appropriately selected depending on the application. For example, in a printed wiring board application, a polar solvent having a boiling point of 160° C. or less such as methyl ethyl ketone, acetone, 1-methoxy-2-propanol is preferable, and its amount used is preferably 10 to 90% by mass as a nonvolatile content. , 30 to 80 mass% is more preferable, and 50 to 70 mass% is further preferable. Further, in adhesive film applications, it is preferable to use, for example, ketones, acetates, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. Is preferably 30 to 60 mass %.

The epoxy resin composition of the present invention is obtained by uniformly mixing the above components. An epoxy resin composition containing an epoxy resin, a curing agent, a filler, and optionally various additives, can be easily made into a cured product by a method similar to a conventionally known method. Examples of the cured product include molded products such as laminates, cast products, molded products, adhesive layers, insulating layers, and films. As a method for obtaining a cured product, the same method as a known epoxy resin composition can be used. Casting, pouring, potting, dipping, drip coating, transfer molding, compression molding, etc., resin sheet, with resin A method in which copper foil, prepreg, or the like is laminated and laminated by heating and pressurizing to form a laminated plate is preferably used. The curing method of the epoxy resin composition varies depending on the compounding components and the compounding amount in the epoxy resin composition, but the curing temperature is usually 80 to 300° C., and the curing time is 10 to 360 minutes. This heating is preferably performed by a two-stage treatment of primary heating at 80 to 180° C. for 10 to 90 minutes and secondary heating at 120 to 200° C. for 60 to 150 minutes, and the glass transition temperature (Tg) is In a compounding system that exceeds the temperature of secondary heating, it is preferable to further perform tertiary heating at 150 to 280° C. for 60 to 120 minutes. By performing such secondary heating and tertiary heating, curing defects can be reduced. When preparing a resin semi-cured product such as a resin sheet, a resin-coated copper foil, and a prepreg, the curing reaction of the epoxy resin composition is usually advanced to such an extent that the shape can be maintained by heating or the like. When the epoxy resin composition contains a solvent, usually, most of the solvent is removed by a method such as heating, decompression, and air drying, but 5% by mass or less of the solvent is left in the resin semi-cured product. May be.

The epoxy resin composition is used in various fields such as circuit board materials, sealing materials, casting materials, conductive pastes, adhesives, and insulating materials. It is useful as an insulation casting, laminated material, sealing material, etc. in the field. Examples of applications include printed wiring boards, flexible wiring boards, laminated boards for electric and electronic circuits such as capacitors, metal foil with resin, film-like adhesives, adhesives such as liquid adhesives, semiconductor encapsulating materials, and underlayers. Examples of the filler material include, but are not limited to, a fill material, an inter-chip fill for 3D-LSI, an insulating material for a circuit board, an insulating sheet, a prepreg, a heat dissipation board, and a resist ink.

Among these various applications, in printed wiring board materials, circuit board insulating materials, and build-up adhesive film applications, so-called electronic component embedded substrates in which passive components such as capacitors and active components such as IC chips are embedded in the substrate. It can be used as an insulating material. Among these, circuit boards (laminated boards) such as printed wiring board materials, epoxy resin compositions for flexible wiring boards, and interlayer insulating materials for build-up boards due to their properties such as high flame retardancy, high heat resistance, and solvent solubility. It is preferable to use it as an application material and a semiconductor encapsulation material.

When the epoxy resin composition is formed into a plate shape such as a laminated plate, the reinforcing filler used is preferably a fibrous shape in terms of dimensional stability, bending strength, etc., and glass cloth, glass mat, glass roving. More preferred is cloth.

By impregnating a fibrous reinforcing substrate with the epoxy resin composition, a prepreg used for a printed wiring board or the like can be prepared. As the fibrous reinforcing substrate, for example, inorganic fibers such as glass, or polyester resin or the like, woven or non-woven fabric of organic fibers such as polyamine resin, polyacrylic resin, polyimide resin or aromatic polyamide resin may be used. It is possible, but not limited to this.

The method for producing a prepreg from an epoxy resin composition is not particularly limited, for example, a varnish-shaped epoxy resin composition containing the organic solvent, a resin prepared by further blending an organic solvent to a suitable viscosity It is obtained by preparing a varnish, impregnating the fibrous base material with the resin varnish, and then heating and drying the resin component to semi-cure (B-stage). The heating temperature is preferably 50 to 200°C, more preferably 100 to 170°C, depending on the type of organic solvent used. The heating time is adjusted depending on the type of organic solvent used and the curability of the prepreg, and is preferably 1 to 40 minutes, more preferably 3 to 20 minutes. At this time, the mass ratio of the epoxy resin composition and the reinforcing base material to be used is not particularly limited, but it is usually preferable to adjust the resin content in the prepreg to be 20 to 80 mass %.

The epoxy resin composition of the present invention can be molded into a sheet or film and used. In this case, it is possible to form a sheet or a film using a conventionally known method. The method for producing the resin sheet is not particularly limited, but, for example, (a) the epoxy resin composition is kneaded in an extruder, then extruded, and molded into a sheet using a T die, a circular die or the like. An extrusion molding method, (b) a casting molding method in which an epoxy resin composition is dissolved or dispersed in a solvent such as an organic solvent, and then cast to form a sheet, (c) other conventionally known sheet molding methods, etc. Can be mentioned. The film thickness (μm) of the resin sheet is not particularly limited, but is preferably 10 to 300, more preferably 25 to 200, and further preferably 40 to 180. The film thickness of the resin sheet when used in the build-up method is particularly preferably 40 to 90 μm. When the film thickness is 10 μm or more, insulation can be obtained, and when the film thickness is 300 μm or less, the circuit distance between the electrodes does not become longer than necessary. The content of the solvent in the resin sheet is not particularly limited, but is preferably 0.01 to 5 mass% with respect to the entire epoxy resin composition. When the content of the solvent in the film is 0.01% by mass or more based on the whole epoxy resin composition, the adhesiveness and the adhesiveness are easily obtained when laminated on the circuit board, and the content is 5% by mass or less. Flatness after heat curing is easily obtained.

As a method for producing an adhesive sheet, a varnish-like epoxy resin composition containing the organic solvent is applied onto a supporting base film which is not dissolved in an organic solvent using a coating machine such as a reverse roll coater, a comma coater, or a die coater. After that, it is obtained by heating and drying to convert the resin component into the B stage. Further, if necessary, another supporting base film is laminated on the coated surface (adhesive layer) as a protective film and dried to obtain an adhesive sheet having release layers on both sides of the adhesive layer.

Examples of the supporting base film include metal foil such as copper foil, polyethylene film, polyolefin film such as polypropylene film, polyester film such as polyethylene terephthalate film, polycarbonate film, silicon film, polyimide film and the like. A polyethylene terephthalate film which is free from defects and has excellent dimensional accuracy and cost is preferable. In addition, a metal foil, particularly a copper foil, which facilitates multilayer formation of the laminated plate is preferable. The thickness of the support base film is not particularly limited, but it is preferably 10 to 150 μm, more preferably 25 to 50 μm, because it has strength as a support and does not easily cause defective lamination.

The thickness of the protective film is not particularly limited, but is generally 5 to 50 μm. In addition, in order to easily release the molded adhesive sheet, it is preferable to perform surface treatment with a release agent in advance. The thickness of the resin varnish applied is preferably 5 to 200 μm, more preferably 5 to 100 μm, as the thickness after drying.

The heating temperature is preferably 50 to 200°C, more preferably 100 to 170°C, depending on the type of organic solvent used. The heating time is adjusted depending on the type of organic solvent used and the curability of the prepreg, and is preferably 1 to 40 minutes, more preferably 3 to 20 minutes.

The resin sheet thus obtained is usually an insulating adhesive sheet having an insulating property. However, by mixing a conductive metal or metal-coated fine particles with an epoxy resin composition, a conductive adhesive sheet can be obtained. You can also get it. The support base film is peeled off after being laminated on a circuit board or after being heat-cured to form an insulating layer. If the support base film is peeled off after the adhesive sheet is heat-cured, adhesion of dust or the like can be prevented in the curing step. Here, the insulating adhesive sheet is also an insulating sheet.

The metal foil with resin obtained by the epoxy resin composition of the present invention will be described. As the metal foil, single, alloy, or composite metal foil of copper, aluminum, brass, nickel or the like can be used. It is preferable to use a metal foil having a thickness of 9 to 70 μm. The method for producing a resin-coated metal foil from the epoxy resin composition and the metal foil of the present invention is not particularly limited, and for example, on one surface of the metal foil, a resin obtained by adjusting the viscosity of the epoxy resin composition with a solvent is used. The varnish can be obtained by applying the varnish using a roll coater or the like and then heating and drying the resin component to semi-cure (B-stage) to form a resin layer. In semi-curing the resin component, for example, it can be dried by heating at 100 to 200° C. for 1 to 40 minutes. Here, the thickness of the resin portion of the metal foil with resin is preferably 5 to 110 μm.

Further, in order to cure the prepreg and the insulating adhesive sheet, generally, a method for curing a laminated board when manufacturing a printed wiring board can be used, but the method is not limited to this. For example, when forming a laminate using a prepreg, one or more prepregs are laminated, a metal foil is arranged on one or both sides to form a laminate, and the laminate is heated under pressure. By doing so, the prepreg can be cured and integrated to obtain a laminated plate. Here, as the metal foil, a single, alloy, or composite metal foil of copper, aluminum, brass, nickel or the like can be used.

The condition for heating and pressing the laminate may be appropriately adjusted under the condition that the epoxy resin composition is cured, and heat and pressure may be applied. However, if the pressure amount of pressurization is too low, bubbles will be generated inside the obtained laminate. Since it may remain and the electrical characteristics may deteriorate, it is preferable to apply pressure under conditions satisfying moldability. The heating temperature is preferably 160 to 250°C, more preferably 170 to 220°C. The applied pressure is preferably 0.5 to 10 MPa, more preferably 1 to 5 MPa. The heating and pressing time is preferably 10 minutes to 4 hours, more preferably 40 minutes to 3 hours. If the heating temperature is low, the curing reaction may not proceed sufficiently, and if it is high, the cured product may be thermally decomposed. If the pressure is low, air bubbles may remain inside the resulting laminate, resulting in poor electrical characteristics.If it is too high, the resin will flow before curing, and a laminate of the desired thickness cannot be obtained. There is a fear. If the heating and pressing time is short, the curing reaction may not proceed sufficiently, and if the heating and pressing time is long, the cured product may be thermally decomposed.

Furthermore, a multilayer board can be prepared by using the single-layer laminated board thus obtained as an inner layer material. In this case, first, a circuit is formed on the laminated plate by an additive method, a subtractive method, or the like, and the formed circuit surface is treated with an acid solution to be blackened to obtain an inner layer material. On this inner layer material, on one or both sides of the circuit forming surface, an insulating layer is formed with a prepreg, a resin sheet, an insulating adhesive sheet or a metal foil with resin, and a conductor layer is formed on the surface of the insulating layer to form a multilayer board. To form.

When the insulating layer is formed by using a prepreg, one or a plurality of prepregs are arranged on the circuit forming surface of the inner layer material, and a metal foil is arranged on the outer side of the prepreg to form a laminate. To form. Then, the laminated body is heated and pressed to be integrally molded, so that the cured product of the prepreg is formed as an insulating layer and the metal foil on the outside thereof is formed as a conductor layer. Here, the same metal foil as that used for the laminated plate used as the inner layer plate can be used. The heat and pressure molding can be performed under the same conditions as the molding of the inner layer material. A printed wiring board can be molded by further forming via holes and circuits on the surface of the multilayer laminated board molded in this manner by an additive method or a subtractive method. Further, by using the printed wiring board as an inner layer material and repeating the above-mentioned construction method, a further multilayered board can be formed.

For example, when forming an insulating layer with an insulating adhesive sheet, the insulating adhesive sheet is arranged on the circuit formation surface of a plurality of inner layer materials to form a laminate. Alternatively, an insulating adhesive sheet is placed between the circuit forming surface of the inner layer material and the metal foil to form a laminate. Then, by heating and pressurizing this laminated body to integrally mold it, the cured product of the insulating adhesive sheet is formed as an insulating layer, and the inner layer material is formed into multiple layers. Alternatively, the inner layer material and the metal foil as the conductor layer are formed as a cured product of an insulating adhesive sheet as an insulating layer. Here, as the metal foil, the same one as that used for the laminated plate used as the inner layer material can be used. The heat and pressure molding can be performed under the same conditions as the molding of the inner layer material.

When the epoxy resin composition is applied to the laminate to form the insulating layer, the epoxy resin composition is applied to a thickness of preferably 5 to 100 μm, and then 100 to 200° C., preferably 150 to 200° C. It is heated and dried for 1 to 120 minutes, preferably 30 to 90 minutes to form a sheet. It is formed by a method generally called casting method. The thickness after drying is preferably 5 to 150 μm, more preferably 5 to 80 μm. The viscosity of the epoxy resin composition is preferably 10 to 40,000 mPa·s, and more preferably 200 to 30,000 mPa·s at 25° C., because a sufficient film thickness is obtained and coating unevenness and streaks are less likely to occur. A printed wiring board can be formed by further forming via holes or circuits on the surface of the multilayer laminated board formed in this manner by an additive method or a subtractive method. Further, by repeating the above-mentioned construction method using this printed wiring board as an inner layer material, it is possible to form a multilayer board having a further multilayer structure.

The encapsulant obtained by using the epoxy resin composition of the present invention includes tape-shaped semiconductor chips, potting liquid encapsulation, underfill, semiconductor interlayer insulating film, etc., and is suitable for these. Can be used for For example, as a semiconductor package molding, an epoxy resin composition is cast, or molded using a transfer molding machine, an injection molding machine, or the like, and further heated at 50 to 200° C. for 2 to 10 hours to form a molded product. The method of obtaining is mentioned.

In order to prepare an epoxy resin composition for a semiconductor encapsulating material, a compounding agent such as an inorganic filler, a coupling agent, a release agent, etc., which is optionally blended with the epoxy resin composition, is added. After pre-mixing the agents, a method of sufficiently melt-mixing until uniform using an extruder, a kneader, a roll and the like can be mentioned. At that time, silica is usually used as the inorganic filler, and in this case, it is preferable to mix the inorganic filler in the epoxy resin composition in a ratio of 70 to 95 mass %.

When the epoxy resin composition thus obtained is used as a tape-shaped sealing material, it is heated to prepare a semi-cured sheet, which is used as a sealing material tape. Is placed on a semiconductor chip, heated to 100 to 150° C. to be softened and molded, and completely cured at 170 to 250° C. When used as a potting liquid encapsulant, the resulting epoxy resin composition may be dissolved in a solvent if necessary, then applied on a semiconductor chip or electronic component, and directly cured. ..

Further, the epoxy resin composition of the present invention can also be used as a resist ink. In this case, the epoxy resin composition is blended with a vinyl-based monomer having an ethylenically unsaturated double bond and a cationic polymerization catalyst as a curing agent, and a pigment, talc, and a filler are added to the composition for resist ink. Then, a method of forming a resist ink cured product after coating on a printed circuit board by a screen printing method is mentioned. The curing temperature at this time is preferably in the temperature range of about 20 to 250°C.

As a result of preparing the epoxy resin composition of the present invention and evaluating the cured product by heat curing, the flame retardancy is good despite the low residual carbon rate. This indicates that the material has excellent tracking resistance. Therefore, it is useful as a material for a substrate on which heat-generating components such as LEDs are mounted.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these as long as the gist thereof is not exceeded. Unless otherwise specified, "part" represents part by mass and "%" represents% by mass. The analysis method and measurement method are shown below.

(1) Epoxy equivalent:
The measurement was carried out according to JIS K 7236 standard, and the unit was represented by "g/eq." Specifically, using an automatic potentiometric titrator (COM-1600ST manufactured by Hiranuma Sangyo Co., Ltd.), chloroform was used as a solvent, a tetraethylammonium bromide acetic acid solution was added, and 0.1 mol/L perchloric acid-acetic acid was added. Titrated with solution.

(2) Dinuclear content, trinuclear content, and number average molecular weight:
The molecular weight distribution was measured using GPC, and the binuclear body content rate and the trinuclear body content rate were from the peak area%, and the number average molecular weight was standard monodisperse polystyrene (A-500, A-1000 manufactured by Tosoh Corporation). , A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40). Specifically, a main body (manufactured by Tosoh Corporation, HLC-8220GPC) equipped with a column (manufactured by Tosoh Corporation, TSKgelG4000H _XL , TSKgelG3000H _XL , TSKgelG2000H _XL ) in series was used, and the column temperature was 40°C. .. Further, tetrahydrofuran was used as the eluent, the flow rate was 1 mL/min, and the detector was an RI (differential refractometer) detector.

(3) Phosphorus content rate:
Sulfuric acid, hydrochloric acid, and perchloric acid were added to the sample and heated to wet ash to convert all phosphorus atoms into orthophosphoric acid. The metavanadate and molybdate were reacted in an acidic sulfuric acid solution, the absorbance at 420 nm of the resulting phosphorous molybdate complex was measured, and a calibration curve was prepared in advance with an aqueous potassium dihydrogen phosphate solution. The phosphorus content was determined.
The phosphorus content of the laminate was expressed as the content of the resin component (organic component other than inorganic components such as filler and glass cloth) of the laminate. That is, it is the phosphorus content of the epoxy resin composition.

(4) Glass transition temperature (Tg):
A differential scanning calorimeter (manufactured by Hitachi High-Tech Science Co., Ltd., EXSTAR6000 DSC6200) was used to measure DSC/Tgm (with respect to the tangent line between the glass state and the rubber state) when the measurement was performed at a temperature rising condition of 20°C/min. The temperature is represented by the middle temperature of the mutation curve).

(5) Flammability:
It was based on UL94 (Safety Certification Standard of Underwriters Laboratories Inc.). The test was performed on 5 test pieces, and the first and second flames were contacted (5 flames each, 2 flames in total, 10 flames in total, 10 times in total). It was determined by V-0, V-1, and V-2.

(6) Thermal conductivity:
Using a thermal conductivity meter QTM-500 manufactured by Kyoto Electronics Manufacturing Co., Ltd., measurement was performed by a thin wire heating method at 23°C.

(7) Tracking resistance:
The measurement was performed according to JIS C 2134. Specifically, a tracking resistance tester (HAT-112-3 manufactured by Yamayo Tester Co., Ltd.) was used. After cutting a measurement sample (a laminated plate having a thickness of 1.6 mm) into 20 mm×20 mm and performing pre-test adjustment for 48 hours at 23±2° C. and 50±5% humidity, 23±2° C. and humidity Under a test environment of 50±5%, a test was conducted by stacking two test pieces so that the thickness of the test piece was 3 mm or more. Confirmation of 100 drops of a 0.1% ammonium chloride aqueous solution was carried out on five test pieces, and the maximum voltage value at which all of them passed was taken as the test result.

Synthesis example 1
Nitrogen gas was prepared by charging 2500 parts of phenol and 7.5 parts of oxalic acid dihydrate into a reaction device consisting of a glass separable flask equipped with a stirrer, a thermometer, a nitrogen gas introducing device, a cooling tube, and a dropping device. While stirring, the mixture was stirred and the temperature was raised. Dropping of 474 parts of 37.4% formalin was started at 80° C., and the dropping was completed in 30 minutes. Furthermore, the reaction temperature was kept at 92° C. and the reaction was carried out for 3 hours. The temperature was raised, and the temperature was raised to 110° C. while removing the water produced by the reaction outside the system. The residual phenol was recovered under reduced pressure at 160° C. to obtain a phenol novolac resin. The temperature was further raised to recover a part of the binuclear body.

Synthesis example 2
A reaction device comprising a glass separable flask equipped with a stirrer, a thermometer, a nitrogen gas introduction device, a cooling tube, and a dropping device was added to a phenol novolac resin 666 parts and epichlorohydrin 2111 parts obtained in Synthesis Example 1. Was charged, the mixture was stirred while introducing nitrogen gas, and the temperature was raised to 50°C. 14.2 parts of 49% sodium hydroxide aqueous solution was charged and the reaction was carried out for 3 hours. The temperature was raised to 64° C., the pressure was reduced to such an extent that water was refluxed, and 458 parts of a 49% aqueous sodium hydroxide solution was added dropwise over 3 hours to carry out a reaction. The temperature was raised to 70°C for dehydration, and the temperature was adjusted to 135°C to recover the remaining epichlorohydrin. After returning to normal pressure, 1232 parts of methyl isobutyl ketone (MIBK) was added and dissolved. 1,200 parts of ion-exchanged water was added, and the mixture was left standing with stirring to dissolve the salt produced as a by-product in water and remove it. Next, 37.4 parts of a 49% aqueous sodium hydroxide solution was charged, and the mixture was stirred and reacted at 80° C. for 90 minutes to carry out a purification reaction. MIBK was added, and washing with water and liquid separation were performed several times to remove ionic impurities. The solvent was recovered to obtain a novolac type epoxy resin. The GPC of the obtained novolac type epoxy resin (a1) is shown in FIG. In the figure, the peak indicated by A is a binuclear body and the peak indicated by B is a trinuclear body. The dinuclear content was 9 area %, the trinuclear content was 36 area %, the number average molecular weight was 648, and the epoxy equivalent was 175.

Synthesis example 3
The novolak type epoxy resin (a2) was obtained in the same manner as in Synthesis Example 2 except that LV-70S (phenol novolac resin manufactured by Gunei Chemical Industry Co., Ltd.) was used in place of the phenol novolac resin obtained in Synthesis Example 1. Got The dinuclear content was 0.7 area %, the trinuclear content was 56 area %, the number average molecular weight was 561, and the epoxy equivalent was 175.

Synthesis example 4
1000 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (phosphorus content rate) of the novolak type epoxy resin (a1) obtained in Synthesis Example 2 was placed in the same apparatus as in Synthesis Example 1. 58 parts of 14.2% (DOPO) was charged, the mixture was stirred while introducing nitrogen gas, and the temperature was raised. Then, 0.06 parts of triphenylphosphine as a catalyst was added at 130° C., and the mixture was reacted at 160° C. for 3 hours to obtain a phosphorus-containing epoxy resin (E1). The obtained phosphorus-containing epoxy resin had an epoxy equivalent of 194 and a phosphorus content of 0.8%.

Synthesis example 5
A phosphorus-containing epoxy resin (E2) was obtained by performing the same operation as in Synthesis Example 4 except that 259 parts of DOPO and 0.26 part of triphenylphosphine were used. The obtained phosphorus-containing epoxy resin had an epoxy equivalent of 279 and a phosphorus content of 3.0%.

Synthesis example 6
A phosphorus-containing epoxy resin (E3) was obtained by performing the same operations as in Synthesis Example 4 except that 304 parts of DOPO and 0.30 parts of triphenylphosphine were used. The obtained phosphorus-containing epoxy resin had an epoxy equivalent of 303 and a phosphorus content of 3.4%.

Synthesis example 7
A phosphorus-containing epoxy resin (E4) was obtained by performing the same operation as in Synthesis Example 4 except that 604 parts of DOPO and 0.60 part of triphenylphosphine were used. The obtained phosphorus-containing epoxy resin had an epoxy equivalent of 550 g/eq and a phosphorus content of 5.5%. The results are summarized in Table 1.

Synthesis example 8
A phosphorus-containing epoxy resin was prepared in the same manner as in Synthesis Example 4, except that the novolac-type epoxy resin (a2) obtained in Synthesis Example 3 was 1000 parts, the DOPO was 259 parts, and the triphenylphosphine was 0.26 parts. (E5) was obtained. The obtained phosphorus-containing epoxy resin had an epoxy equivalent of 279 and a phosphorus content of 3.0%.

Synthesis Example 9
1000 parts of YDPN-638 (Nippon Steel Chemical & Materials Co., Ltd. phenol novolac type epoxy resin, dinuclear content 21 area %, trinuclear content 15 area %, number average molecular weight 700, epoxy equivalent 179), DOPO And 58 parts of triphenylphosphine and 0.06 parts of triphenylphosphine were used to perform the same operations as in Synthesis Example 4 to obtain a phosphorus-containing epoxy resin (E6). The obtained phosphorus-containing epoxy resin had an epoxy equivalent of 199 and a phosphorus content of 0.8%.

Synthesis example 10
A phosphorus-containing epoxy resin (E7) was obtained by performing the same operation as in Synthesis Example 4 except that 1000 parts of YDPN-638, 604 parts of DOPO, and 0.60 part of triphenylphosphine were used. The obtained phosphorus-containing epoxy resin had an epoxy equivalent of 575 and a phosphorus content of 5.5%.

Synthesis Example 11
N-775 (phenolic novolac type epoxy resin manufactured by DIC Corporation, dinuclear content 8 area%, trinuclear content 7 area%, number average molecular weight 6640, epoxy equivalent 187) 1000 parts, DOPO 259 parts, A phosphorus-containing epoxy resin (E8) was obtained by performing the same operation as in Synthesis Example 4 except that 0.26 part of triphenylphosphine was used. The obtained phosphorus-containing epoxy resin had an epoxy equivalent of 303 and a phosphorus content of 3.0%.

The epoxy resin, curing agent, filler, and other additives used in the following examples will be described.

[Epoxy resin]
E1 to E8: Phosphorus-containing epoxy resin obtained in Synthesis Examples 4 to 11 E9: Phenol glyoxal type epoxy resin (KDT-4400, KDT-4400, epoxy equivalent 220)
E10: Cresol novolac type epoxy resin (Nittetsu Chemical & Materials Co., Ltd., YDCN-704, epoxy equivalent 208)

[Curing agent]
A1: Dicyandiamide (Nippon Carbide Co., Ltd., active hydrogen equivalent 21)
A2: 4,4'-diaminediphenyl sulfone (active hydrogen equivalent 62)
A3: Phenol novolac resin (Aika Kogyo Co., Ltd., Shonor BRG-557, active hydrogen equivalent 105, softening point 80° C.)

[Filler]
F1: Aluminum hydroxide (manufactured by Showa Denko KK, Heidilite H42M, average particle size (D50) 1 μm)
F2: Spherical silica (Admatex Co., Ltd., Adma M Fine SO-C2, average particle size F3: Spherical alumina (Denka Co., Ltd., DAM-05, average particle size (D50) 5 μm)
F4: Spherical alumina (Denka Co., Ltd., DAM-70, average particle size (D50) 70 μm)
F5: Boron nitride (manufactured by Momentive Co., PT120, average particle diameter (D50) 10 μm)
(D50) 0.5 μm)

[Other]
2E4MZ: Curing accelerator, 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemicals Co., Ltd., Cureazole 2E4MZ)
KBM403: Glycidoxymethoxysilane type coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403)

Example 1
E1 of 100 parts, E9 of 50 parts, and 450 parts of a mixed solution of methyl ethyl ketone and methoxy propanol in an equivalent mass ratio were charged in the same container and uniformly dissolved. A solution prepared by dissolving 7.8 parts of A1 in 29.2 parts of N,N-dimethylformamide and 0.01 part of 2E4MZ were added thereto, and further mixed and homogenized to obtain an epoxy resin varnish.
On the other hand, as a separate filler treatment, 2.8 parts of KBM403 was thoroughly mixed with 71 parts of F2 as a 10% methanol solution, and then the methanol was dried and removed, and 84 parts of F1 and 125 parts of F3 were added to this. 232 parts of F4 and 48 parts of F5 were charged to obtain a filler mixture.
The filler mixture was added to the epoxy resin varnish, and the mixture was stirred and mixed at 1000 rpm for 30 minutes using a homodisper to obtain an epoxy resin composition varnish (1).

After the obtained epoxy resin composition varnish (1) was impregnated into glass cloth WEA7628XS13 (manufactured by Nitto Boseki Co., Ltd., 0.18 mm thickness), it was dried in a hot air circulation oven at 150° C. for 8 minutes to be in a B stage state. I got a prepreg of. Eight sheets of the obtained prepreg were stacked, copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., 3EC, thickness 35 μm) was further stacked on the upper and lower layers, and a pressure of 2 MPa was applied at 130° C.×15 minutes and 190° C. for 70 minutes. Curing was carried out in a vacuum press while doing so to obtain a laminated plate having a thickness of 1.6 mm. Table 1 shows the results of the characteristic evaluation (Tg, flammability, thermal conductivity, and tracking resistance) of the obtained laminated plate.

Examples 2-8 and Comparative Examples 1-4
The epoxy resin composition varnish, the prepreg, the laminated plate, and the test piece were obtained by blending with the blending amount (parts) in Table 1 and performing the same operation as in Example 1. The same test as in Example 1 was performed, and the results are shown in Table 1.

In Example 1, even if the phosphorus content is as low as 0.5%, flame retardancy is obtained, and further, tracking resistance and extremely high thermal conductivity are obtained. Moreover, in Example 5, it is possible to have both sufficient flame retardancy and thermal conductivity while maintaining excellent tracking resistance even if the phosphorus content is increased.
On the other hand, in the comparative example, heat resistance deteriorates when trying to maintain tracking resistance and flame resistance, and flame resistance deteriorates when trying to maintain tracking resistance and heat resistance. You can't get a board.
As described above, when the phosphorus-containing epoxy resin obtained by reacting the phenol novolac type epoxy resin having a specific molecular weight distribution with the phosphorus compound is used, the amount of the phosphorus compound used is reduced and the tracking resistance of CTI 600 V or more is obtained. It is possible to obtain a laminate having both improved flame retardancy and higher thermal conductivity.

Claims (15)

An epoxy resin composition containing an epoxy resin, a curing agent, and a filler, wherein the epoxy resin has a binuclear content of 15 area% or less and a trinuclear content of 15 to 60 in gel permeation chromatography measurement. Area-%, containing a phosphorus-containing epoxy resin obtained by reacting a novolac type epoxy resin having a number average molecular weight of 350 to 700 and a molecular weight distribution with a phosphorus compound represented by the following formula (1) An epoxy resin composition characterized by:

In the formula (1), R ¹ and R ² each independently represent a hydrocarbon group having 1 to 20 carbon atoms which may have a hetero element, and may be linear, branched or cyclic. Alternatively, R ¹ and R ² may combine to form a cyclic structure. n1 and n2 are 0 or 1 each independently. The epoxy resin composition according to claim 1, wherein the phosphorus-containing epoxy resin is represented by the following general formula (5).

In Formula (5), A is an aromatic ring group, and the aromatic ring group may have a substituent. X is a divalent linking group. m is 1 or 2. i is the number of repetitions and indicates a number of 0 or more, and the average value thereof is 0.5 to 5. Z is independently a phosphorus-containing group or a glycidyloxy group represented by the following formula (6), but not all Zs are either groups, and a phosphorus represented by the following formula (6) At least one containing group and at least one glycidyloxy group are included.

In the formula ^{(6), R 1, R} 2, n1, and n2 are the same meanings as ^{R 1, R 2, n1,} and n2 in the formula (1). The epoxy resin composition according to claim 1 or 2, wherein the phosphorus content of the phosphorus-containing epoxy resin is 0.8 to 5.5% by mass. The epoxy resin composition according to any one of claims 1 to 3, wherein the phosphorus content of the epoxy resin composition is 0.3 to 4.0 mass% as solid content excluding the filler. The epoxy resin, together with the phosphorus-containing epoxy resin, has an epoxy equivalent of 100 to 300 g/eq. The epoxy resin composition according to any one of claims 1 to 4, comprising the phosphorus-free epoxy resin. The epoxy resin composition according to any one of claims 1 to 5, wherein the active hydrogen group of the curing agent is 0.3 to 2.0 mol with respect to 1 mol of the epoxy group of the epoxy resin. The epoxy resin composition according to any one of claims 1 to 6, wherein the compounding amount of the filler is 50 to 400 parts by mass with respect to 100 parts by mass of the epoxy resin. The filler is a general-purpose filler having a thermal conductivity of less than 10 W/m·K and a high-heat conductive filler having a thermal conductivity of 10 W/m·K or more, and the ratio of the general-purpose filler to the high-thermal conductive filler is 15/85. It is 30/70 (mass ratio), The epoxy resin composition of any one of Claims 1-7. The epoxy resin composition according to claim 8, wherein the general-purpose filler is at least one of silica, titanium oxide, aluminum hydroxide, magnesium hydroxide, or calcium carbonate. The epoxy resin composition according to claim 8, wherein the high thermal conductive filler is at least one of metal nitride, metal oxide, carbide, corundum, or aluminum powder. The epoxy resin composition according to any one of claims 1 to 10, which contains 0.1 to 3 parts by mass of the coupling agent with respect to 100 parts by mass of the epoxy resin. A cured product obtained by curing the epoxy resin composition according to any one of claims 1 to 11. A prepreg characterized by using the epoxy resin composition according to any one of claims 1 to 11. An adhesive sheet comprising the epoxy resin composition according to any one of claims 1 to 11. A laminate comprising the epoxy resin composition according to any one of claims 1 to 11.

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