JP2020122034A - Epoxy resin composition, and cured product of the same - Google Patents

Abstract

To provide a non-halogen flame retardant epoxy resin composition excellent in heat resistance, CTI properties and dielectric properties in a cured product and a circuit board.SOLUTION: An epoxy resin composition contains an epoxy resin, a curing agent, and an inorganic filler. The epoxy resin composition is such that: the epoxy resin includes a phosphorus-containing epoxy resin which is obtained by reacting a phosphorus-containing phenolic compound represented by the following formula (1) with a novolac type epoxy resin having a specific molecular-weight distribution as the essential components. (In the formula, Rand Rrepresent a C1-20 hydrocarbon group which may have a hetero element; Rand Rmay be bonded to form a cyclic structure; n1 and n2 are independently 0 or 1; and Y is C6-20 trivalent aromatic hydrocarbon group.)SELECTED DRAWING: None

Description

The present invention relates to an epoxy resin composition containing a halogen-free flame-retardant epoxy resin containing a phosphorus atom in the molecular skeleton as an essential component, and further an epoxy resin cured product obtained by curing the epoxy resin composition, which is used for an electronic circuit board. Epoxy, suitable for film materials, encapsulants, molding materials, casting materials, adhesives, electrical insulation paints, flame-retardant composite materials, powder paints, etc. used for prepregs, copper-clad laminates and electronic parts A resin composition is provided.

Epoxy resins have excellent adhesiveness, flexibility, heat resistance, chemical resistance, insulating properties, and curing reactivity, and are therefore widely used in paints, civil engineering adhesion, casting, electric/electronic materials, film materials, and the like. In particular, it is widely used by giving various functions to an epoxy resin in a printed wiring board application which is one of electric and electronic materials.

With the dramatic increase in the amount of information in recent years, portable devices that are one of the uses of printed wiring boards and infrastructure devices such as base stations that connect them are constantly required to be highly functional. In mobile devices, the number of layers and fine wiring are increasing for the purpose of downsizing, and materials with a lower dielectric constant are required to make the substrate thinner, and the bonding surface is reduced by fine wiring. Adhesive materials are needed. Substrates for base stations are required to have materials with lower dielectric loss tangent in order to suppress signal attenuation due to high frequencies.

Further, in recent years, with the development of electric vehicles and autonomous driving technology, high CTI (Comparative Tracking Index) that does not insulate even when a high-voltage current flows through a vehicle-mounted substrate and high heat resistance that can withstand high-temperature operation have been demanded for the substrate. ..
In addition, the need for environmental harmony that does not generate highly toxic decomposed gas at the time of combustion has increased worldwide, and the demand for flame retardance that does not use halides for substrates has also increased.

In response to these high demands, a halogen-free flame-retardant technique using a phosphorus compound has been studied in recent years, and phosphorus-containing epoxy resins and phosphorus-containing phenol resins as disclosed in Patent Documents 1 to 7 have been proposed. However, if they are mixed, not only heat resistance, CTI characteristics, dielectric loss tangent but also water absorption and adhesiveness may be deteriorated, and it is very difficult to satisfy the required characteristics at the same time.

JP 04-11662 A JP, 2000-309623, A JP-A-11-166035 JP, 11-279258, A JP, 2001-288247, A JP 2001-123049 A JP, 2003-040969, A

Therefore, the problems to be solved by the present invention include halogen-free flame retardancy, excellent performance in low dielectric property, high heat resistance, and high CTI property without deteriorating adhesiveness and water absorption, and lamination. The present invention provides a flame-retardant epoxy resin composition and a cured product thereof, which are useful for applications such as molding, casting, and adhesion.

In order to solve the above problems, the present inventor has diligently studied a halogen-free flame-retardant resin composition excellent in low dielectric property, high heat resistance, and high CTI property, and as a result, a specific molecular weight distribution among epoxy resins is obtained. By blending a novolac type epoxy resin with a phosphorus compound and a phosphorus-containing epoxy resin obtained by using a quinone compound into the composition, low dielectric property, high heat resistance, high CTI property and halogen-free flame retardancy can be achieved at the same time. Was completed and the present invention was completed.

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。Ｙは３価の炭素数６〜２０の芳香族炭化水素基である。 That is, the present invention is an epoxy resin composition containing an epoxy resin (A), a curing agent (B), and an inorganic filler (C), wherein the epoxy resin (A) is represented by the following formula (1). It contains a phosphorus-containing epoxy resin (A1) obtained by reacting a phosphorus-containing phenol compound (p1) with a novolac-type epoxy resin as an essential component, and the novolac-type epoxy resin has a viscosity of 2% in the measurement by gel permeation chromatography (GPC). It is a novolac type epoxy resin having a molecular weight distribution in which the nuclear content is 15 area% or less, the trinuclear content is 15 to 60 area% and the number average molecular weight (Mn) is 350 to 700. It is a characteristic epoxy resin composition.

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. Y is a trivalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

Here, 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. Tetrahydrofuran (THF) was used as the eluent, the flow rate was 1 mL/min, and the detector was an RI (differential refractometer) detector. As a measurement sample, 0.1 g of the sample was dissolved in 10 mL of THF. The binuclear body content rate and the trinuclear body content rate are calculated from the obtained chromatogram, and Mn is measured by a calibration curve based on standard polystyrene.

式（２）において、Ｒ^１、Ｒ^２、ｎ１、及びｎ２はそれぞれ独立に、上記式（１）のＲ^１、Ｒ^２、ｎ１、及びｎ２を同義である。 The phosphorus-containing epoxy resin is an epoxy resin obtained by reacting the phosphorus compound (p2) represented by the following formula (2), the phosphorus-containing phenol compound (p1), and the novolac type epoxy resin as essential components. Is preferred.

In the formula ^(2), R ^1, R 2, n1, and n2 are independently the same with ^{R 1,} R 2, n1, and n2 in the formula (1).

The epoxy equivalent of the epoxy resin (A) is 200 to 800 g/eq. Is preferred. This epoxy equivalent is the epoxy equivalent of all epoxy resins (A) compounded in the epoxy resin composition when not only the phosphorus-containing epoxy resin but also other epoxy resins are used in combination, and the active group equivalent of the curing agent. It corresponds to.

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

The compounding amount of the inorganic filler (C) is 10 to 60 parts by mass with respect to the total amount of the epoxy resin (A), the curing agent (B), and the inorganic filler (C). preferable.

Furthermore, it is preferable to include a thermosetting resin and/or a thermoplastic resin other than the epoxy resin as the other resin, and the blending amount when the other resin is included is 100 parts by mass of the epoxy resin (A). It is preferably 3 to 100 parts by mass.

Further, it is preferable to contain a nitrogen-based flame retardant, and when the nitrogen-based flame retardant is contained, the compounding amount is preferably 1 to 40 parts by mass with respect to 100 parts by mass of the epoxy resin (A).

Further, the present invention is a prepreg, an insulating sheet, an adhesive sheet, a laminate, a sealing material, or a casting material characterized by using the epoxy resin composition, which is obtained by curing the epoxy resin composition. It is a thing.

Epoxy resin composition of the present invention, the cured product shows a cured product physical properties and a high flame retardancy with a high glass transition temperature while maintaining good adhesive force and water absorption, and further excellent in dielectric properties or CTI properties. Therefore, it exhibits excellent characteristics in a laminated board and an electronic circuit board which are required to have high functions such as low dielectric constant, low dielectric loss tangent, and high insulation.

The GPC chart of the novolac type epoxy resin of Synthesis example 2 is shown.

Hereinafter, embodiments of the present invention will be described in detail.

The epoxy resin composition of the present invention contains an epoxy resin (A), a curing agent (B), and an inorganic filler (C) as essential components. The epoxy resin (A) is a phosphorus-containing epoxy obtained by reacting a novolac type epoxy resin having a specific molecular weight distribution with a phosphorus-containing phenol compound (p1) and a phosphorus compound (p2) used as necessary. Resin (A1) is an essential component. The phosphorus-containing epoxy resin (A1) may be referred to as the "phosphorus-containing epoxy resin (A1) of the present invention".

The above-mentioned novolak type epoxy resin having a specific molecular weight distribution is a reaction product of phenols and aldehydes, and is a polyfunctional novolac type resin obtained by reacting a novolak resin having a specific molecular weight distribution with epihalohydrin. It is an epoxy resin. Examples of the phenols used include phenol, cresol, ethylphenol, butylphenol, styrenated phenol, cumylphenol, naphthol, catechol, resorcinol, naphthalenediol, and bisphenol A. Examples of aldehydes include formalin, formaldehyde, hydroxybenzaldehyde, salicylaldehyde and the like. In the present invention, the novolac resin also includes an aralkylphenol resin using a condensing agent such as xylylenedimethanol, xylylenedichloride, bischloromethylnaphthalene, and bischloromethylbiphenyl in place of aldehydes.

Specific examples of the conventional novolac type epoxy resin include phenol novolac type epoxy resin (for example, Epotote YDPN-638 (manufactured by Nippon Steel Chemical & Material Co., Ltd.), Epicoat 152, 154 (manufactured by Mitsubishi Chemical Co., Ltd.), Epichron. N-740, N-770, N-775 (DIC Corporation) and the like, and cresol novolac type epoxy resin (for example, Epotote YDCN-700 series (manufactured by Nippon Steel Chemical & Material Co., Ltd.), Epicron N-660, N. -665, N-670, N-673, N-695 (manufactured by DIC Corporation), EOCN-1020, EOCN-102S, EOCN-104S (manufactured by Nippon Kayaku Co., Ltd.), etc., and alkyl novolac type epoxy resin ( For example, Epotote ZX-1071T, ZX-1270, ZX-1342 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.) and aromatic modified phenol novolac type epoxy resin (for example, Epotote ZX-1247, YDAN-1000 series (Japanese). Etc.), naphthol novolac type epoxy resin (for example, Epotote ZX-1142L (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc.) and β naphthol aralkyl type epoxy resin (for example, ESN-155). , ESN-185V, ESN-175 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc., and dinaphthol aralkyl type epoxy resin (for example, ESN-355, ESN-375 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc.) Or α-naphthol aralkyl type epoxy resin (for example, ESN-475V, ESN-485 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.)), biphenyl aralkyl phenol type epoxy resin (for example, NC-3000 (manufactured by Nippon Kayaku Co., Ltd.) ) Etc.), polyfunctional epoxy resin (for example, EPPN-501H, EPPN-502H (manufactured by Nippon Kayaku Co., Ltd.), etc.), dicyclopentadiene aralkyl type epoxy resin (for example, HP-7200, HP-7200H, HP-7200HH). , HP-7200HHH (manufactured by DIC Corporation) and the like, and bisphenol novolac type epoxy resin and the like. However, most of these epoxy resins do not have a specific molecular weight distribution.

To obtain a novolac type epoxy resin with a specific molecular weight distribution, a specific molecular weight distribution can be obtained by adjusting the molar ratio of phenols and aldehydes and removing low molecular weight components from the resulting novolac resin. After obtaining the novolac resin, it is desirable to epoxidize it. Moreover, you may epoxidize the novolac resin obtained by the manufacturing method described in Unexamined-Japanese-Patent No. 2002-194041 and Unexamined-Japanese-Patent No. 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. When the molar ratio is small, a large amount of high molecular weight bodies are formed, and the amount of dinuclear bodies and trinuclear bodies is small.

The novolak resin having a specific molecular weight distribution used as a raw material for obtaining the phosphorus-containing epoxy resin (A1) of the present invention is represented by the following formula (3). In the present specification, a binuclear body is a case where k in the formula (3) 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 (3) is n−2, in other words, a structure in which n=k+2.

式（３）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 (3), 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 and 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 obtained novolak resin by utilizing the difference in solubility of various solvents or a method for dissolving the binuclear body in an alkaline aqueous solution for removal Methods and 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 applying a known epoxidation method to the thus obtained novolak resin having a controlled molecular weight. The molecular weight distribution of the novolak resin is generally reflected in the molecular weight distribution of the novolak type epoxy resin obtained by epoxidizing the novolak resin. Further, a novolac type epoxy resin having a specific molecular weight distribution can also 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 (4). In the present specification, a binuclear body is a case where i in the formula (4) 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 (4) is n−2, in other words, a structure in which n=i+2.

式（４）において、Ａ、Ｘ、及びｍは上記式（３）のＡ、Ｘ、及びｍとそれぞれ同義である。Ｇは下記式（５）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 (4), A, X, and m have the same meanings as A, X, and m in the formula (3), respectively. G is a glycidyloxy group represented by the following formula (5). i is the number of repetitions and indicates a number of 0 or more, and the average value thereof is 0.5 to 5.

The novolac type epoxy resin having a specific molecular weight distribution used in the present invention has a binuclear content of 15 area% or less, preferably 5 to 12 area %. If the binuclear body exceeds the upper limit, heat resistance, flame retardancy, and dielectric properties are adversely affected. On the other hand, by containing a small amount of binuclear body, physical properties such as adhesive strength can be improved. 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 %. If the trinuclear content is less than 15 area %, the heat resistance tends to be poor, and if it exceeds 60 area %, the adhesiveness tends to be poor. The range of tetranuclear and pentanuclear or higher is not particularly specified, but the total content of trinuclear and tetranuclear is preferably 30 to 70 area %. When the total content of trinuclear and tetranuclear is 30 to 70 area %, the flame retardancy is further improved. The content of pentanuclear or higher is preferably 45 area% or less, more preferably 40 area% or less. When the content of the pentanuclear compound or more is 45 area% or less, a cured product having higher adhesive strength can be obtained.
The epoxy equivalent is 100 to 400 g/eq. Is preferred. 350-700 are preferable and, as for Mn, 380-600 are more preferable. When Mn exceeds 700, the viscosity of the obtained phosphorus-containing epoxy resin (A1) 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 characteristics of 400 V or more cannot be obtained. Moreover, 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 remarkably high because the high molecular weight component of tetranuclear or higher is increased. As a result, the workability in producing the laminated plate is remarkably deteriorated, and the yield is often deteriorated due to poor impregnation into the glass cloth. If the trinuclear body content exceeds 60% by area, the cross-linking density of the cured product may decrease and the heat resistance may deteriorate because the components of the tetranuclear body and above are reduced.

The phosphorus-containing phenol compound (p1) represented by the above formula (1) is obtained by reacting the phosphorus compound (p2) represented by the above formula (2) with a quinone compound. In the formula (1), Y is a trivalent aromatic hydrocarbon group having 6 to 20 carbon atoms and has a structure derived from a quinone compound. The aromatic hydrocarbon group is preferably a benzene ring group or a naphthalene ring group. The aromatic hydrocarbon group has, as a substituent, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, and a carbon number. It may have an aralkyl group having 7 to 12 or an aralkyloxy group having 7 to 12 carbon atoms.
R ¹ and R ² are hydrocarbon groups having 1 to 20 carbon atoms which may have a hetero atom, and they may be the same or different, and may be linear, branched or cyclic. .. In addition, R ¹ and R ² may combine to form a cyclic structure. In particular, an aromatic ring group such as a benzene ring is preferable. When R ¹ and R ² are aromatic ring groups, as a substituent, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, and 6 to 10 carbon atoms. And an aryl group having 7 to 11 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, or an aralkyloxy group having 7 to 11 carbon atoms. Examples of the hetero atom include an oxygen atom and the like, which can be contained between the carbons constituting the hydrocarbon chain or the hydrocarbon ring.

Examples of the phosphorus compound (p2) include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (for example, HCA (manufactured by Sanko Co., Ltd.)) and 8-methyl-9,10-. Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 8-phenyl-9,10-dihydro- 9-oxa-10-phosphaphenanthrene-10-oxide, 2,6,8-tri-butyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 6,8-dicyclohexyl- 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, dimethylphosphine oxide, diethylphosphine oxide, dibutylphosphine oxide, diphenylphosphine oxide, dibenzylphosphine oxide, ditolylphosphine oxide, bis(methoxyphenyl) ) Phosphine oxide, 1,4-cyclooctylenephosphine oxide, 1,5-cyclooctylenephosphine oxide (for example, CPHO (manufactured by Nippon Kagaku Kogyo Co., Ltd.)) and the like can be mentioned. These phosphorus compounds may be used alone or in combination of two or more.

Examples of the quinone compound include benzoquinone, naphthoquinone, toluquinone, anthraquinone, isomers thereof, and compounds having a substituent such as a hydrocarbon group. These quinone compounds may be used alone or in combination of two or more. The purity (mass %) of the quinone compound is not particularly limited, but 90% or more is preferable, 95% or more is more preferable, and 98% or more is further preferable.

The molar ratio of the phosphorus compound (p2) to the quinone compound is preferably less than 1 mol, more preferably 0.99 to 0.2 mol, and still more preferably 0.98 to 0.4 with respect to 1 mol of the phosphorus compound. Molar is more preferred. When the phosphorus-containing phenol compound (p1) obtained as the reaction product is isolated, the higher the molar ratio, the better. When the phosphorus-containing phenol compound (p1) and the phosphorus compound (p2) are used in combination, the reaction product as it is reacts with the novolac type epoxy resin having a specific molecular weight distribution, so that the necessary molar ratio is obtained. It is preferable to prepare. When the quinone compound becomes excessive, unreacted quinone compound remains. If the reactive product is reacted with the epoxy resin as it is, the quinone compound remains in the phosphorus-containing epoxy resin (A1) as an unreacted component, so that the physical properties of the cured product are likely to deteriorate. Therefore, a washing step after the reaction becomes essential and is industrially disadvantageous, which is not preferable. If it is less than 0.2 mol, heat resistance and flame retardancy may be adversely affected.

In obtaining the phosphorus-containing epoxy resin, the phosphorus-containing phenol compound (p1) may be reacted alone with the novolac type epoxy resin, but the phosphorus-containing phenol compound (p1) and the phosphorus compound (p2) may be used together. In this case, the molar ratio (p2/p1) of the phosphorus compound (p2) and the phosphorus-containing phenol compound (p1) is preferably 0/100 to 80/20, more preferably 1/99 to 60/40, and more preferably 2/98. ˜50/50 is more preferable, and 5/95 to 25/75 is particularly preferable. Within this range, the molecular weight of the obtained phosphorus-containing epoxy resin does not become so large. Therefore, the epoxy resin composition does not have a viscosity that adversely affects the impregnation property into the glass cloth and the like, which is preferable from the viewpoint of handling. When the molar ratio (p2/p1) of the phosphorus compound (p2) and the phosphorus-containing phenol compound (p1) is converted to the raw material molar ratio (p2/q) of the phosphorus compound (p2) and the quinone compound (q), When the raw material molar ratio (p2/q) is 1/0.5, the production molar ratio (p2/p1) corresponds to 50/50, and the raw material molar ratio (p2/q) is 1/0.99. At this time, the generated molar ratio (p2/p1) corresponds to 1/99. Since many complicated steps are required to isolate the phosphorus-containing phenol compound (p1), it is industrially preferable to use it in a state of being mixed with the unreacted starting phosphorus compound (p2).

Examples of the phosphorus-containing phenol compound (p1) include 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-[2-(dihydroxynaphthyl)]-. 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-8-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene -10-Oxide, 10-[2-(dihydroxynaphthyl)]-8-benzyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphinylhydroquinone, diphenylphosphenyl- 1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, 1,5-cyclooctylenephosphinyl-1,4-phenyldiol and the like can be mentioned. These phosphorus-containing phenol compounds may be used alone or in combination of two or more.

The reaction to obtain the phosphorus-containing epoxy resin (A1) has a hydroxyl phosphorus-containing phenol compound (p1) (-OH) reacts with the epoxy groups of the novolak type epoxy _{resin, -O-CH 2 -CH (OH} ) - ... will be. Moreover, the P—H bond of the phosphorus compound (p2) 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 (6). The epoxy equivalent is 200 to 800 g/eq. Is preferred. The reaction product is the phosphorus-containing epoxy resin represented by the formula (6), but since the unreacted raw material novolac type epoxy resin represented by the formula (4) usually remains, 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 (6) 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（６）において、Ａ、Ｘ、及びｍは上記式（４）のＡ、Ｘ、及びｍとそれぞれ同義である。Ｚはそれぞれ独立に下記式（７）で表されるリン含有基、グリシジルオキシ基、又は下記式（９）で表されるリン含有基であるが、全部のＺがいずれか一つの基であることはなく、下記式（７）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。ｊ１は繰返し数であって、０以上の数である。また、原料にリン化合物（ｐ２）を使用する場合は、Ｚ及び下記式（８）のＺ^１の内の少なくとも一つは、式（７）で表わされるリン含有基とグリシジルオキシ基に加え、下記式（９）で表されるリン含有基を含む。

In the formula (6), A, X, and m have the same meanings as A, X, and m in the formula (4). Each Z is independently a phosphorus-containing group represented by the following formula (7), a glycidyloxy group, or a phosphorus-containing group represented by the following formula (9), and all Z are any one group. However, at least one of each of the phosphorus-containing group and the glycidyloxy group represented by the following formula (7) is included. j1 is the number of repetitions and is a number of 0 or more. When a phosphorus compound (p2) is used as a raw material, at least one of Z and Z ¹ of the following formula (8) is added to the phosphorus-containing group and the glycidyloxy group represented by the formula (7), It contains a phosphorus-containing group represented by the following formula (9).

式（７）において、Ｒ^１、Ｒ^２、ｎ１、ｎ２、及びＹは上記式（１）におけるＲ^１、Ｒ^２、ｎ１、ｎ２、及びＹとそれぞれ同義である。Ｔは下記式（８）である。

In the formula ^{(7), R 1, R} 2, n1, n2, and Y are as defined ^{R 1, R 2, n1,} n2, and Y in the formula (1). T is the following formula (8).

式（８）において、Ａ、Ｘ、及びｍは、上記式（４）におけるＡ、Ｘ、及びｍとそれぞれ同義である。Ｚ^１はそれぞれ独立に上記式（７）で表されるリン含有基、グリシジルオキシ基、又は下記式（９）で表されるリン含有基であるが、上記式（７）で表されるリン含有基が含まれなくてもよい。ｊ２、ｊ３は繰返し数であって、０以上の数である。

In the formula (8), A, X, and m have the same meanings as A, X, and m in the formula (4). Z ¹ is independently a phosphorus-containing group represented by the above formula (7), a glycidyloxy group, or a phosphorus-containing group represented by the following formula (9), and the phosphorus represented by the above formula (7) is The containing group may not be included. j2 and j3 are the numbers of repetitions and are numbers of 0 or more.

式（９）において、Ｒ^１、Ｒ^２、ｎ１、及びｎ２は上記式（１）のＲ^１、Ｒ^２、ｎ１、及びｎ２とそれぞれ同義である。

In the formula ^{(9), R 1, R} 2, n1, and n2 are the same meanings as ^{R 1, R 2, n1,} and n2 in the formula (1).

The phosphorus-containing epoxy resin (A1) of the present invention is obtained by reacting the phosphorus-containing phenol compound (p1) with a novolac type epoxy resin having a specific molecular weight distribution, but is not affected by the effects of the present invention. In addition, other epoxy resins and modifiers can be used together.

The reaction between the phosphorus-containing phenol compound (p1) and the novolac type epoxy resin having a specific molecular weight distribution is carried out by a known method. A method of reacting a phosphorus compound (p2) with a quinone compound to obtain a phosphorus-containing phenol compound (p1), and subsequently reacting with a novolac type epoxy resin, the phosphorus compound (p2) and the quinone compound in a novolac type epoxy resin After reacting to obtain a phosphorus-containing phenol compound (p1), a method of further reacting with a novolak type epoxy resin, a phosphorus compound (p2) and a quinone compound are reacted in advance to further isolate the phosphorus-containing phenol compound (p1). Alternatively, there is a method of reacting with a novolac type epoxy resin, but it is not particularly limited.
The reaction temperature may be the temperature used for the reaction of the two-step method epoxy resin, and is preferably 100 to 250°C, more preferably 120 to 200°C.

A catalyst may be used for the reaction in order to shorten the time and the reaction temperature. The catalyst that can be used is not particularly limited, and those usually used in the reaction of the two-step method epoxy resin can be used. For example, tertiary amines such as benzyldimethylamine, quaternary ammonium salts such as tetramethylammonium chloride, phosphines such as triphenylphosphine and tris(2,6-dimethoxyphenyl)phosphine, and ethyltriphenyl. Examples thereof include phosphonium salts such as phosphonium bromide and imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole. These catalysts may be used alone or in combination of two or more kinds. Also, it may be divided and used in several times.

The amount of the catalyst is not particularly limited, but is preferably 5 parts by mass or less, more preferably 1 part by mass or less, and 0.5 parts by mass or less based on 100 parts by mass of the total amount of the novolac type epoxy resin and other epoxy resins that can be used together. Is more preferable. When the amount of the catalyst is large, the self-polymerization reaction of the epoxy group may proceed and the resin viscosity may increase depending on the case.

Examples of the modifier that can be used in combination include bisphenol A, bisphenol F, bisphenol AD, tetrabutylbisphenol A, hydroquinone, methylhydroquinone, dimethylhydroquinone, dibutylhydroquinone, resorcin, methylresorcin, biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxy. Diphenyl ether, dihydroxystilbenes, phenol novolac resin, cresol novolac resin, bisphenol A novolac resin, dicyclopentadiene phenol resin, phenol aralkyl resin, naphthol novolac resin, terpene phenol resin, heavy oil modified phenol resin, brominated phenol novolac resin, etc. Polyphenols obtained by condensation reaction of phenols and phenols with aldehydes such as hydroxybenzaldehyde, crotonaldehyde, glyoxal, aniline, phenylenediamine, toluidine, xylidine, diethyltoluenediamine, diaminodiphenylmethane, diamino Diphenylethane, diaminodiphenylpropane, diaminodiphenylketone, diaminodiphenylsulfide, diaminodiphenylsulfone, bis(aminophenyl)fluorene, diaminodiethyldimethyldiphenylmethane, diaminodiphenylether, diaminobenzanilide, diaminobiphenyl, dimethyldiaminobiphenyl, biphenyltetraamine, bis Examples include amine compounds such as aminophenylanthracene, bisaminophenoxybenzene, bisaminophenoxyphenyl ether, bisaminophenoxybiphenyl, bisaminophenoxyphenyl sulfone, bisaminophenoxyphenylpropane, and diaminonaphthalene, but are not limited thereto. Alternatively, two or more kinds may be used in combination.

As the other epoxy resin that can be used in combination, specifically, in addition to the above-mentioned conventional novolac type epoxy resin, hydroquinone type epoxy resin (for example, Epotote YDC-1312, ZX-1027 (manufactured by Nippon Steel Chemical & Material Co., Ltd. ) Etc.), biphenol type epoxy resin (for example, YX-4000 (manufactured by Mitsubishi Chemical Co., Ltd.), ZX-1251 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), etc.), bisphenol A type epoxy resin (for example, Epotote YD-127). , YD-128, YD-8125, YD-825GS, YD-011, YD-900, YD-901 (manufactured by Nippon Steel Chemical & Material Co., Ltd.), bisphenol F type epoxy resin (for example, Epotote YDF-170, YDF-8170, YDF-870GS, YDF-2001 (manufactured by Nippon Steel Chemical & Material Co., Ltd.), bisphenol fluorene type epoxy resin (for example, ZX-1201 (manufactured by Nippon Steel Chemical & Material Co., Ltd.)), naphthalene diol Type epoxy resin (for example, ZX-1355 (manufactured by Nittetsu Chemical & Materials Co., Ltd.)) and other polyglycidyl ether type epoxy resins produced from phenol compounds such as polyhydric phenol resins and epihalohydrin, and diaminodiphenylmethane tetraglycidyl. Polyglycidyl amine type epoxy resins produced from amine compounds such as amines (e.g. Epotote YH-434, YH-434GS (manufactured by Nippon Steel Chemical & Materials Co., Ltd.)) and epihalohydrin, and dimer acid type epoxy resins (eg , YD-171 (manufactured by Nittetsu Chemical & Materials Co., Ltd.) and the like, and polyglycidyl ester type epoxy resins produced from epihalohydrin and the like, but not limited to these, and two types. You may use together above. Dicyclopentadiene aralkyl type epoxy resin, α-naphthol aralkyl type epoxy resin, aromatic modified phenol novolac type epoxy resin, etc. are preferable for low dielectric applications, and cresol novolac type epoxy resin, dinaphthol aralkyl type epoxy resin, diamino for high heat resistance applications. Diphenylmethane tetraglycidyl amine, polyfunctional epoxy resin and the like are preferable.
The epoxy equivalent of the epoxy resin used in combination is 100 to 800 g/eq. Is desirable.

When the phosphorus-containing phenol compound (p1) is reacted with the novolac type epoxy resin having a specific molecular weight distribution, an inert solvent may be used if necessary. Specifically, hexane, heptane, octane, decane, dimethylbutane, pentene, cyclohexane, methylcyclohexane, benzene, toluene, xylene, various hydrocarbons such as ethylbenzene, ethyl ether, isopropyl ether, butyl ether, diisoamyl ether, methyl Ethers such as phenyl ether, ethyl phenyl ether, amyl phenyl ether, ethyl benzyl ether, dioxane, methyl furan, tetrahydrofuran, etc., methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, cellosolve acetate, ethylene glycol isopropyl ether, diethylene glycol dimethyl ether, methyl ethyl Examples thereof include carbitol, propylene glycol monomethyl ether, dimethylformamide, and dimethylsulfoxide, but the present invention is not limited to these, and two or more kinds may be mixed and used.

The epoxy resin (A) in the epoxy resin composition may include an epoxy resin (A2) other than the phosphorus-containing epoxy resin (A1). Examples of the epoxy resin (A2) include novolac type epoxy resins having the above-mentioned specific molecular weight distribution used in the production of the phosphorus-containing epoxy resin (A1), and the above-mentioned various epoxy resins which can be used in combination.

Any general curing agent for epoxy resin can be used as the curing agent (B). Specifically, various amines such as polyfunctional phenol compounds, dicyandiamide, aromatic amines and aliphatic amines, acid anhydrides, polythiol compounds, isocyanate compounds, blocked isocyanate compounds, alkyd resins, hydrazides, acidic polyesters , And benzoxazines. These curing agents may be used alone or in combination of two or more. Among these, from the viewpoint of compatibility with other resins in the laminate making process, ease of drying conditions, ease of laminate processing, etc., polyfunctional phenol compounds, dicyandiamide, various amines, acid Anhydrides are preferred, and polyfunctional phenolic compounds or dicyandiamide are particularly preferred.

The amount of the curing agent (B) used is preferably 0.3 to 2.0 moles of the active groups of the curing agent (B), and 0.5 to 1. 5 mol is more preferable, and 0.5 to 1.0 mol is further preferable. In the case of polyfunctional phenol compounds, acid anhydrides and amines, the range of 0.8 to 1.2 mol is particularly preferable, and in the case of dicyandiamide, the range of 0.4 to 0.6 mol is particularly preferable. When the amount of the curing agent (B) used is less than 0.3 mol, the heat resistance and flame retardancy of the cured product are significantly reduced.
If it exceeds 2.0 mol, the heat resistance and flame retardancy are similarly reduced. Further, when the acid anhydrides or aromatic amines are used in an amount of more than 2.0 mol, it is necessary to increase the curing catalyst, which may reduce the storage stability of the prepreg. Further, when dicyandiamide is used in an amount of more than 2.0 mol, the securement of gel time in the B stage is greatly impaired, and voids may occur during the molding of the laminate, or the copper foil may have poor adhesion.

Examples of the polyfunctional phenol compounds include bisphenol A, bisphenol F, bisphenol AD, bisphenol C, bisphenol K, bisphenol Z, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol S, and 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 , Methylresorcin, hydroquinone, monomethylhydroquinone, dimethylhydroquinone, trimethylhydroquinone, mono-t-butylhydroquinone, di-t-butylhydroquinone, etc. dihydroxybenzenes, dihydroxynaphthalene, dihydroxymethylnaphthalene, dihydroxymethylnaphthalene, trihydroxynaphthalene, etc. Hydroxynaphthalene, 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, Butyraldehyde, valeraldehyde, capronaldehyde, benzaldehyde, chloraldehyde, bromaldehyde, hydroxybenzaldehyde, crotonaldehyde, glyoxal, etc.) and various condensing agents (for example, dicyclopentadiene, xylylene glycol, bis(methylol)biphenyl, bis( Examples thereof include a phenol resin obtained by a condensation reaction with chloromethyl)biphenyl and the like.

Examples of the amines include aliphatic amine compounds such as diethylenetriamine, diethyltoluenediamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, and 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, diamino Aromatic amine compounds such as diphenyl ether and 4,4′-methylenebis(2-methyl-6-ethylaniline), dicyandiamide, and polyamide polyamines that are condensation products of polycarboxylic acids such as dimer acid and polyamines. To be

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

Other curing agents include benzoxazines such as bisphenol F-aniline type benzoxazine and diaminodiphenylmethane-phenol type benzoxazine. For low-dielectric applications, styrene maleic anhydride, terminal phenol type polyphenylene ether, dicyclopentadiene phenol resin, phenol aralkyl resin, α-naphthol aralkyl resin, active ester compounds are preferable, and for high heat-resistant applications, benzoxazine, β-naphthol aralkyl resin, diamino. Diphenylmethane, diaminodiphenyl sulfone, diaminodiphenyl ether and the like are preferable.

The inorganic filler (C) is fused silica, crystalline silica, spherical silica, hollow silica, aluminum hydroxide, alumina, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, Examples include inorganic fillers such as calcium silicate, mica, glass fiber powder magnesium hydroxide, talc, calcined talc, clay, kaolin, boehmite, titanium oxide, and silica balloons, but pigments and the like may be added.
As described above, the compounding amount of the inorganic filler is 10 to 60% by weight based on the total amount of the epoxy resin, the curing agent and the inorganic filler. Generally, the reason for using an inorganic filler is improvement in impact resistance. In particular, unless the blending amount is 10% by mass or more, the effect of impact resistance is small. However, if the blending amount exceeds 60% by mass, the adhesiveness, which is an item required for use as a laminated plate, decreases. Further, a fibrous filler such as glass fiber, pulp fiber, synthetic fiber or ceramic fiber may be contained in the resin composition. Further, when a metal hydroxide such as aluminum hydroxide or magnesium hydroxide is used, it acts as a flame retardant aid, and flame retardancy can be secured even if the phosphorus content is low. In addition, when a hydrated metal oxide such as aluminum hydroxide or a metal sulfate such as barium sulfate is used, CTI characteristics are excellent.

Further, in the epoxy resin composition containing the phosphorus-containing epoxy resin (A1) 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, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, alcohols such as methanol, ethanol, ethylene glycol, propylene glycol, butyl diglycol, pine oil, ethyl acetate, butyl acetate, Acetates such as methoxybutyl acetate, methyl cellosolve acetate, cellosolve acetate, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, carbitol acetate, benzyl alcohol acetate, and benzoates such as methyl benzoate and ethyl benzoate. , Methyl cellosolve, cellosolve, butyl cellosolve, etc., carbitols such as methyl carbitol, carbitol, butyl carbitol, aromatic hydrocarbons such as benzene, toluene, xylene, and sulfoxides such as dimethyl sulfoxide. And 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, and pentaerythritol polyglycidyl ether, glycidyl esters such as neodecanoic acid glycidyl ester, and glycidyl amines such as phenyldiglycidylamine and tolyldiglycidylamine. Is mentioned.

These organic solvents or reactive diluents are preferably used in an amount of 90% by mass or less as a non-volatile component, and the appropriate type and amount thereof are appropriately selected depending on the application. For example, in printed wiring board applications, a polar solvent having a boiling point of 160° C. or lower, such as methyl ethyl ketone, acetone, or 1-methoxy-2-propanol, is preferable, and the amount thereof is used as a solid content in the epoxy composition containing a filler. , 10 to 90 mass% is preferable, 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, acetic acid esters, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. 30 to 60 mass% is preferable.

A curing accelerator can be used in the composition of the present invention, if necessary. Examples of curing accelerators that can be used are imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-(dimethylaminomethyl)phenol, 1,8-diaza-bicyclo(5 , 4,0) Undecene-7 and other tertiary amines, triphenylphosphine, tricyclohexylphosphine, triphenylphosphine triphenylborane and other phosphines, and metal compounds such as tin octylate. If necessary, the curing accelerator may be used in an amount of 0.02 to 5.0 parts by mass based on 100 parts by mass of the epoxy resin component in the epoxy resin composition of the present invention. By using the curing accelerator, the curing temperature can be lowered or the curing time can be shortened.

Further, a thermosetting resin or a thermoplastic resin other than the epoxy resin can be used in the composition of the present invention, if necessary. Examples of thermosetting resins include, but are not limited to, vinyl compounds, maleimide compounds, thermosetting polyimide compounds, melamine compounds, urea compounds, urethane compounds, and the like. Examples of the thermoplastic resin include nitrile rubber, butadiene rubber, styrene butadiene rubber, styrene isoprene rubber, polyphenylene ether resin, vinyl resin, phenoxy resin, fluororesin, phenol resin, acrylic resin, petroleum resin, indene resin, coumarone indene. Resin, phenoxy resin, polyurethane resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin, polyetherimide resin, polyphenylene ether resin, modified polyphenylene ether resin, polyethersulfone resin, polysulfone resin, polyetheretherketone resin, polyphenylene Examples thereof include sulfide resins and polyvinyl formal resins, but are not limited to these. A phenoxy resin is preferable from the viewpoint of compatibility with the epoxy resin. From the viewpoint of low dielectric properties, polyphenylene ether resins, modified polyphenylene ether resins, bismaleimide compounds, maleimide resins and the like are preferable, and from the viewpoint of high heat resistance properties, triallyl isocyanurate, polyether ether ketone resins and the like are preferable.
When using a thermosetting resin or a thermoplastic resin, the compounding amount thereof is preferably 3 to 100 parts by mass, more preferably 5 to 60 parts by mass, and further preferably 10 to 50 parts by mass with respect to 100 parts by mass of the epoxy resin. It is a mass part.

In addition, a nitrogen-based flame retardant can be used in the composition of the present invention in order to further improve the flame retardancy. As the nitrogen-based flame retardant, for example, melamine compounds, triazine compounds, guanidine compounds, guanamine compounds, cyanuric acid compounds, isocyanuric acid compounds, amine compounds, amide compounds, thiourea, urethane compounds, phenothiazine compounds Examples thereof include, but are not limited to, phosphazene compounds, phosphoric acid amides, polyphosphoric acid amides, and ammonium phosphate compounds.
When a nitrogen-based flame retardant is used, its amount is preferably 1 to 40 parts by mass, more preferably 1 to 10 parts by mass, based on 100 parts by mass of the epoxy resin.

When the epoxy resin composition is used as a plate-shaped substrate or the like, a fibrous filler is mentioned as a preferable filler in terms of its dimensional stability, bending strength and the like. More preferably, a glass fiber substrate obtained by knitting glass fibers in a mesh shape can be mentioned.

By impregnating a fibrous base material with the epoxy resin composition, a prepreg used for a printed wiring board or the like can be prepared. As the fibrous substrate, inorganic fibers such as glass, polyester resin, etc., polyamine resin, polyacrylic resin, polyimide resin, woven or non-woven fabric of organic fibers such as aromatic polyamide resin can be used, but is not limited thereto. Not something. The method for producing a prepreg from an epoxy resin composition is not particularly limited, and for example, the epoxy resin composition is immersed in a resin varnish prepared by adjusting the viscosity of a solvent to impregnate it, and then dried by heating to obtain a resin. It is obtained by semi-curing (B-stage) the components, and can be dried by heating at 100 to 200° C. for 1 to 40 minutes, for example. Here, the amount of resin in the prepreg is preferably 30 to 80% by mass of resin.

Further, to cure the prepreg, a method for curing a laminated board which is generally used when manufacturing a printed wiring board can be used, but the method is not limited to this. For example, when forming a laminated board using a prepreg, one or more prepregs are laminated, a metal foil is arranged on one side or both sides to form a laminated body, and this laminated body is heated and pressed to form a laminated body. Turn into. Here, as the metal foil, a single, alloy, or composite metal foil of copper, aluminum, brass, nickel or the like can be used. Then, the prepared laminate is heated under pressure to cure the prepreg and obtain a laminate. At that time, it is preferable that the heating temperature is 160 to 220° C., the pressurizing pressure is 50 to 500 N/cm ² , and the heating and pressurizing time is 40 to 240 minutes, and the desired cured product can be obtained. If the heating temperature is low, the curing reaction does not proceed sufficiently, and if it is high, the epoxy resin composition may start to decompose. In addition, when the pressure is low, air bubbles may remain inside the resulting laminate, which may lower the electrical characteristics.If the pressure is high, the resin will flow before curing, and a cured product of the desired thickness will be obtained. There is a risk that you will not be able to. Further, if the heating and pressing time is short, the curing reaction may not proceed sufficiently, and if the heating and pressing time is long, thermal decomposition of the epoxy resin composition in the prepreg may occur, which is not preferable.

An epoxy resin cured product can be obtained by curing the epoxy resin composition in the same manner as a known epoxy resin composition. 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, resin A method of suitably forming a laminated board by laminating in the form of an attached copper foil, prepreg or the like and heating and pressurizing to form a laminated board is suitably used. The curing temperature at that time is usually in the range of 100 to 300° C., and the curing time is usually about 1 hour to 5 hours.

The epoxy resin cured product of the present invention can be in the form of a laminate, a molded product, an adhesive, a coating film, a film, or the like.
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 by using a conventionally known method, but as an example of a suitable molding method, the epoxy resin composition is dissolved in a solvent, the resin solution obtained, After coating by a conventionally known method on a substrate such as a metal foil, a polyester film, or a polyimide film, the surface of which has been subjected to a peeling treatment, it is dried and peeled from the substrate to form an insulating sheet, an insulating film, an adhesive sheet or an adhesive. There is a method to make a film.

The method for producing the adhesive sheet is not particularly limited, but the epoxy resin composition of the present invention is preferably 5 to 100 μm on a carrier film that does not dissolve in the epoxy resin composition such as a polyester film and a polyimide film. To a thickness of 100 to 200° C. and then dried for 1 to 40 minutes to form a sheet. A resin sheet is generally formed by a method called a casting method. At this time, if the sheet to which the epoxy resin composition is applied is surface-treated with a release agent in advance, the molded adhesive sheet can be easily peeled off. Here, it is desirable to form the adhesive sheet to have a thickness of 5 to 80 μm. The adhesive sheet thus obtained usually becomes an insulating adhesive sheet having insulation, but a conductive adhesive sheet is obtained by mixing a conductive metal or metal-coated fine particles with an epoxy resin composition. be able to.

Next, a method for producing a laminated board using the prepreg or the insulating adhesive sheet of the present invention will be described. When forming a laminated board using prepreg, one or more prepregs are laminated, a metal foil is arranged on one side or both sides to form a laminate, and this laminate is heated and pressed to integrate the layers. To do. 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 desirable to apply pressure under the condition that the moldability is satisfied. For example, the temperature can be set to 160 to 220° C., the pressure to 49.0 to 490.3 N/cm ² (5 to 50 kgf/cm ² ), and the heating time can be set to 40 to 240 minutes, respectively. 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 and blackened to obtain an inner layer material. A multilayer board is formed by forming an insulating layer with a prepreg or an insulating adhesive sheet on one side or both sides of the inner layer material on which the circuit is formed, and forming a conductor layer on the surface of the insulating layer.

When the insulating layer is formed by the insulating adhesive sheet, the insulating adhesive sheet is arranged on the serial number circuit forming surface of the 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, the laminate is heated and pressed to be integrally molded, so that 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 which is the conductor layer are formed by using the cured product of the insulating adhesive sheet as the insulating layer. Here, the same metal foil 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 outermost circuit-forming surface resin of the inner layer material is applied to the epoxy resin composition in a thickness of preferably 5 to 100 μm, and then 100 It is heated and dried at ~200°C for 1 to 90 minutes to form a sheet. It is formed by a method generally called casting method. The thickness after drying is preferably formed to 5 to 80 μm. A printed wiring board can be formed by further forming via holes and circuits on the surface of the multilayer laminate thus formed by an additive method or a subtractive method. Further, by further repeating the above-mentioned construction method using this printed wiring board as an inner layer material, it is possible to form a multilayered board.

When forming an insulating layer with a prepreg, one or more laminated prepregs are arranged on the circuit forming surface of the inner layer material, and a metal foil is further arranged on the outside to form a laminate. To do. Then, by heating and pressurizing this laminate to integrally mold it, 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 may 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 way 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 further multilayer board.

The encapsulant obtained using the epoxy resin composition includes a tape-like encapsulant for semiconductor chips, a potting liquid encapsulant, an underfill resin, and an interlayer insulating film for semiconductors, which are preferably used be able to.

In order to adjust the epoxy resin composition for a semiconductor encapsulating material, the epoxy resin composition is preliminarily supplemented with other coupling agents, additives such as release agents, inorganic fillers, etc. After mixing, a method of using an extruder, a kneader, a roll or the like to sufficiently mix until uniform is mentioned. When used as a tape-shaped sealant, the resin composition obtained by the method described above is heated to produce a semi-cured sheet, which is used as a sealant tape, and the sealant tape is then applied to a semiconductor chip. Examples of the method include placing, heating to 100 to 150° C. to soften and molding, and completely curing at 170 to 250° C. Further, when used as a potting liquid encapsulant, after dissolving the resin composition obtained by the above-mentioned method in a solvent as needed, it is applied on a semiconductor chip or an electronic component and directly cured. Good.

As a result of preparing an epoxy resin composition and evaluating the epoxy resin cured product of the laminate by heating and curing, a novolac type epoxy resin having a specific molecular weight distribution, a phosphorus compound, and a phosphorus-containing epoxy resin (A1) obtained from a quinone compound Since it has high flame retardancy, the degree of freedom in blending with other resins is increased, and it is possible to further lower dielectric constant, higher heat resistance, and higher CTI while ensuring flame retardancy.

The present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified, "parts" represents parts by mass and "%" represents% by mass. The measuring method was as follows.
The measuring method is shown below.

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

Dinuclear content, trinuclear content, tetranuclear content, pentanuclear or higher content, Mn, and weight average molecular weight (Mw): The molecular weight distribution is measured using GPC, and the dinuclear content is determined. , Trinuclear body content rate, tetranuclear body content rate, pentanuclear body content rate or more are based on the peak area%, and Mn and Mw are standard monodisperse polystyrene (A-500, A-1000, A manufactured by Tosoh Corporation). -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, THF was used as an eluent, the flow rate was 1 mL/min, and the detector was an RI (differential refractometer) detector.

Phosphorus content: Sulfuric acid, hydrochloric acid, and perchloric acid were added to the sample and heated to wet ash to convert all phosphorus atoms to orthophosphoric acid. By reacting metavanadate and molybdate in an acidic sulfuric acid solution, the absorbance of the resulting molybdate complex such as limba was measured at 420 nm, and the phosphorus atom determined by the calibration curve previously prepared using potassium dihydrogen phosphate. The content rate was expressed in %.
The phosphorus content of the laminate was expressed as the content of the resin component of the laminate. That is, it is the phosphorus content of the epoxy resin composition.

Hydroxyl equivalent: Measured in accordance with JIS K 0070 standard, and the unit is represented by "g/eq." Unless otherwise specified, the hydroxyl group equivalent of the phenol resin means the phenolic hydroxyl group equivalent.

Copper foil peel strength and interlayer adhesive strength: Measured according to JIS C 6481, and interlayer adhesive strength was measured by peeling between the 7th and 8th layers.

Flammability: According to 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, 2 flames each, a total of 10 flames), and the flame burning duration was calculated according to the criteria of the same standard. Yes, it was judged by V-0, V-1, and V-2.

Glass transition temperature: The peak top temperature of tan δ when measured with a dynamic viscoelasticity measuring device (EXSTAR 6000 DMS6100 manufactured by SII Nano Technology Co., Ltd.) under a temperature rising condition of 5° C./min.

Specific permittivity and dielectric loss tangent: Evaluated by determining the specific permittivity and dielectric loss tangent at a frequency of 1 GHz by the capacitance method using a material analyzer (manufactured by AGILENT Technologies) in accordance with IPC-TM-650 2.5.5.9. did.

CTI characteristics: Measured in accordance with 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 board 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 a humidity of 50±5%, 23±2° C. and a humidity are obtained. Under a test environment of 50±5%, two test pieces were stacked so that the thickness of the test piece was 3 mm or more, and the test was performed at a current value of 400V. Confirmation of 100 drops of 0.1% ammonium chloride aqueous solution was carried out on five test pieces, and when all of them passed, it was evaluated as “◯”, and when even one failed, it was evaluated as “x”.

Synthesis example 1
A glass separable flask equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen gas introducing device was charged with 2500 parts of phenol and 7.5 parts of oxalic acid dihydrate, and stirring was performed while introducing nitrogen gas. Heating was performed to raise the temperature. 474 parts of 37.4% formalin was added dropwise at 80° C., and the addition 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 reaction product water 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. The binuclear content of the obtained phenol novolac resin was 10 area %, and the trinuclear content was 38 area %.

Synthesis example 2
The same apparatus as in Synthesis Example 1 was charged with 666 parts of the phenol novolac resin obtained in Synthesis Example 1, 2110 parts of epichlorohydrin, and 17 parts of water, and the temperature was raised to 50° C. with stirring. 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 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 49% sodium hydroxide aqueous solution was charged, and stirring reaction was carried out at 80° C. for 90 minutes to carry out a purification reaction. MIBK was added and washed with water several times to remove ionic impurities. The solvent was recovered to obtain a phenol novolac type epoxy resin. The GPC of the obtained phenol novolac type epoxy resin 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 content of dinuclear body was 9 area %, the content of trinuclear body was 36 area %, the content of tetranuclear body was 17 area %, the content of pentanuclear body or more was 38 area %, Mn 513, Mw 713 and epoxy equivalent 174.

Synthesis example 3
In the same device as in Synthesis Example 1, 176 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (manufactured by Sanko Co., Ltd., HCA, phosphorus content 14.2%) and 411 parts of toluene were added. It was charged and heated to dissolve. Next, 66 parts of 1,4-naphthoquinone (manufactured by Tokyo Chemical Industry Co., Ltd., purity of 98% or more) was charged while paying attention to heat generation, and the temperature was kept at 90° C. or lower and kept for 30 minutes. The temperature was further gradually raised and maintained at the reflux temperature for 2 hours. After partly recovering toluene, 761 parts of the phenol novolac type epoxy resin obtained in Synthesis Example 2 was charged, and the mixture was stirred while introducing nitrogen gas and heated to 130°C. 0.24 parts was added using triphenylphosphine as a catalyst, and the mixture was reacted at 160° C. for 3 hours to obtain a phosphorus-containing epoxy resin (A11). The obtained phosphorus-containing epoxy resin (A11) had an epoxy equivalent of 318 and a phosphorus content of 2.5%.

Synthesis example 4
The same operation as in Synthesis Example 3 was performed except that HCA was 127 parts, 1,4-naphthoquinone was 83 parts, the phenol novolac type epoxy resin obtained in Synthesis Example 2 was 794 parts, and triphenylphosphine was 0.21 part. By doing so, a phosphorus-containing epoxy resin (A12) was obtained. The obtained phosphorus-containing epoxy resin (A12) had an epoxy equivalent of 293 and a phosphorus content of 1.8%.

Synthesis example 5
Instead of 761 parts of the phenol novolac type epoxy resin obtained in Synthesis Example 2, 475 parts of a general-purpose phenol novolac type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., Epotote YDPN-638, binuclear content 22 areas) %, trinuclear content 15 area%, tetranuclear content 10 area%, pentanuclear or higher content 53 area%, Mn 528, Mw 1127, epoxy equivalent 176) and 281 parts of bisphenol F type epoxy resin (Nippon Steel) Chemical & Material Co., Ltd., Epotote YDF-170, epoxy equivalent 170) was charged, and the same as Synthesis Example 3 except that HCA was 177 parts, 1,4-naphthoquinone was 74 parts, and triphenylphosphine was 0.25 part. Various operations were performed to obtain a phosphorus-containing epoxy resin (H1). The obtained phosphorus-containing epoxy resin (H1) had an epoxy equivalent of 324 and a phosphorus content of 2.5%.

Synthesis example 6
Instead of 761 parts of the phenol novolac type epoxy resin obtained in Synthesis Example 2, 496 parts of Epototo YDPN-638 and 301 parts of Epotote YDF-170 were charged, 127 parts of HCA, 82 parts of 1,4-naphthoquinone, A phosphorous-containing epoxy resin (H2) was obtained by performing the same operation as in Synthesis Example 3 except that 0.21 part of triphenylphosphine was used. The obtained phosphorus-containing epoxy resin (H2) had an epoxy equivalent of 285 and a phosphorus content of 1.8%.

Synthesis example 7
In the same apparatus as in Example 1, 105.66 parts of 3,3′,4,4′-diphenyltetracarboxylic dianhydride, 194.34 parts of dimer diamine (PRIAMINE 1074 manufactured by Croda Japan Co., Ltd.), and N- 420 parts of methyl-2-pyrrolidone and 280 parts of xylene were added and mixed at 40° C. for 1 hour to obtain a polyamic acid solution. This polyamic acid solution is heated to 190° C., heated and stirred for 4 hours, 80 parts of N-methyl-2-pyrrolidone and 200 parts of xylene are added to complete the imidization reaction, and a polyimide resin solution (D5) Got The solid content of the obtained polyimide resin solution was 29.5%.

The abbreviations used in Examples and Comparative Examples are as follows.

[Epoxy resin (A)]
A11: Phosphorus-containing epoxy resin obtained in Synthesis Example 3 A12: Phosphorus-containing epoxy resin obtained in Synthesis Example 4 H1: Phosphorus-containing epoxy resin obtained in Synthesis Example 5 H2: Phosphorus-containing epoxy resin obtained in Synthesis Example 6 Epoxy resin A21: dicyclopentadiene/phenol co-condensed epoxy resin (KDCP-130, KDCP-130, epoxy equivalent 254)
A22: α-naphthol aralkyl type epoxy resin (manufactured by Nippon Steel Chemical & Materials Co., ESN-475V, epoxy equivalent 330)
A23: Tetramethylbiphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX4000H, epoxy equivalent 195)
A24: Biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 275)
A25: Cresol novolac type epoxy resin (Nippon Steel Chemical & Material Co., Ltd., Epotote YDCN-700-7, epoxy equivalent 204)
A26: Bisphenol A type epoxy resin (Nippon Steel Chemical & Material Co., Ltd., Epotote YD-011, epoxy equivalent 475)
A27: Tetraglycidyl ether type epoxy resin (Nippon Steel Chemical & Materials Co., Ltd., Epototo YDG-414, epoxy equivalent 187)
A28: β-naphthol aralkyl type epoxy resin (manufactured by Nippon Steel Chemical & Materials Co., ESN-375, epoxy equivalent 170)

[Curing agent (B)]
B1: benzoxazine resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., YBZ-2213, benzoxazine equivalent 219 g/eq.)
B2: Styrene/maleic acid co-condensation resin (manufactured by Cray Valley, SMA2000, acid anhydride equivalent 316 g/eq.)
B3: Dicyclopentadiene/phenol co-condensation resin (manufactured by Gunei Chemical Co., Ltd., GDP9140, hydroxyl equivalent 196 g/eq.)
B4: dicyandiamide (manufactured by Nippon Carbide Industry Co., Ltd., dicyandiamide, active hydrogen equivalent 21 g/eq.)
B5: Phenol-terminated PPO resin (SAbic, SA90, hydroxyl equivalent 803 g/eq.)
B6: Active ester type curing agent (manufactured by DIC Corporation, HPC-8000, active group equivalent 223 g/eq.)
B7: 2,2-bis(4-cyanatophenyl)propane (manufactured by Lonza Japan KK, BandCy, active hydrogen equivalent 139 g/eq.)
B8: Phenol novolac resin (Aika Kogyo Co., Ltd., Shonor BRG-557, softening point 80° C., hydroxyl group equivalent 105 g/eq.)

[Inorganic filler (C)]
C1: Spherical silica (Admatex Co., Ltd., Adma M Fine SO-C2, average particle size 0.5 μm)
C2: Crystalline silica (Crystallite CMC-12, manufactured by Tatsumori Co., Ltd., average particle diameter 5 μm)
C3: Alumina monohydrate (Kawai Lime Industry Co., Ltd., average particle size 1.5 μm)

[Other resins]
D1: Polybutadiene (Kuraray Co., Ltd., LBR-307, SP value 8.3, weight average molecular weight 8000)
D2: Hyperbranched polyamide-imide resin (DIC Corporation, ELG503)
D3: Vinyl-terminated PPE resin (OPE-2St 1200, manufactured by Mitsubishi Gas Chemical Co., Inc.)
D4: indene coumarone resin (manufactured by Nikkei Chemical Co., Ltd., H-100)
D5: Polyimide resin obtained in Synthesis Example 7 D6: Styrene-butadiene rubber (Kuraray Co., Ltd., L-SBR-820)
D7: 2,2-bis(4-(4-maleimidophenoxy)phenyl)propane (manufactured by Daiwa Kasei Co., Ltd., BMI-4000)
D8: triallyl isocyanurate (TAIC, manufactured by Nippon Kasei Co., Ltd.)
D9: Carboxyl group-containing nitrile rubber (Nipol 1072J, manufactured by Nippon Zeon Co., Ltd.)
D10: Hydrogenated styrene butadiene rubber (Asahi Kasei Corporation, Tuftec H1041)

[Nitrogen flame retardant]
MC15: Melamine cyanurate (manufactured by DSM Japan, melapur MC15)

[Curing accelerator]
2E4MZ: 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemicals Co., Ltd., Cureazole 2E4MZ)

[Other]
Glass cloth: E glass cloth (manufactured by Nitto Boseki Co., Ltd., glass cloth WEA 7628 XS13, 0.18 mm thick)

Example 1
As epoxy resin (A), 100 parts of A11 and 30 parts of A21, as a curing agent (B), 30 parts of B1, 10 parts of B2, 3 parts of B3, 0.5 part of B4, and 30 parts of B5. Parts, 100 parts of C1 as an inorganic filler and 0.1 parts of 2E4MZ as a curing accelerator were mixed and dissolved in methyl ethyl ketone (MEK) to obtain an epoxy resin composition varnish (1).

A glass cloth was impregnated with the obtained epoxy resin composition varnish (1). The impregnated glass cloth was dried in a hot air circulation oven at 150°C for 11 minutes to obtain a prepreg. Eight pieces of the obtained prepreg and copper foils (manufactured by Mitsui Mining & Smelting Co., Ltd., 3EC-III, thickness 35 μm) were stacked on top of each other and vacuum-pressed at 2 MPa under a temperature condition of 130° C.×15 minutes +190° C.×80 minutes. A laminated plate having a thickness of 1.6 mm was obtained. Further, both sides of the obtained laminated plate were etched to obtain a test piece for measuring flame retardancy. Table 1 shows the results of the glass transition temperature, the peel strength of the copper foil, the interlayer adhesion, and the flame retardancy of the laminate.

Further, the obtained prepreg was loosened and sieved to obtain a powdery prepreg powder having a 100 mesh pass. The obtained prepreg powder was placed in a fluororesin mold and vacuum-pressed at 2 MPa under the temperature condition of 130° C.×15 minutes +190° C.×80 minutes to obtain a 50 mm square×2 mm thick test piece. Table 1 shows the results of relative permittivity and dielectric loss tangent of the test piece.

Examples 2-10, Comparative Examples 1-2
A11 to A12, H1, A21 to 24, B1 to B7, C1 to C3, D1 to D8, MC15, and 2E4MZ were compounded in the compounding amounts (parts) of the prescription in Table 1, and by the same operation as in Example 1, An epoxy resin composition varnish was obtained, and then a laminate and a test piece were obtained. The same test as in Example 1 was conducted, and the results are shown in Table 1. All blending amounts are solid content values.

In the case of the phosphorus-containing epoxy resin which has been conventionally used, since the flame retardance is insufficient, it is necessary to add a large amount of the flame retardant, but if so, the heat resistance is lowered and the dielectric property is also deteriorated. On the other hand, in the case of the phosphorus-containing epoxy resin of the example, since the flame retardancy is high, even if the amount of the curing agent that contributes to the low dielectric constant is increased, the flame retardancy is not deteriorated, and further lower dielectric constant and higher Heat resistance was possible.

Examples 11-20, Comparative Examples 3-4
A11 to 12, H2, A25 to A28, B4, B8, C3, D9 to D10, MC15, and 2E4MZ were compounded in the compounding amounts (parts) of the formulation of Table 2, and the epoxy resin was treated in the same manner as in Example 1. A composition varnish was obtained, and then a laminate and a test piece were obtained. The same test as in Example 1 was performed, and the results are shown in Table 2. All blending amounts are solid content values.

In the case of the conventionally used phosphorus-containing epoxy resin, since the flame retardancy is insufficient by itself, it is necessary to add a flame retardant, but then the CTI is deteriorated. On the other hand, in the case of the phosphorus-containing epoxy resin of the example, both flame retardancy and CTI can be achieved, and even if a high heat-resistant resin such as A25 to A28 is added, the flame retardancy and CTI are further improved. High heat resistance was possible.

Claims (16)

An epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler, wherein the epoxy resin is obtained by reacting a phosphorus-containing phenol compound represented by the following formula (1) with a novolac type epoxy resin as essential components. The phosphorus-containing epoxy resin is a novolac type epoxy resin, which has a binuclear content of 15 area% or less and a trinuclear content of 15 to 60 area% as measured by gel permeation chromatography, and has a number average molecular weight of The epoxy resin composition is a novolac type epoxy resin having a molecular weight distribution of 350 to 700.

(Here, 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. R ¹ and R ² may combine to form a cyclic structure, n1 and n2 are each independently 0 or 1. Y is a trivalent aromatic hydrocarbon group having 6 to 20 carbon atoms. .) The epoxy resin according to claim 1, wherein the phosphorus-containing epoxy resin is an epoxy resin obtained by reacting the phosphorus compound represented by the following formula (2) with the phosphorus-containing phenol compound and the novolac type epoxy resin as essential components. Composition.

(Here, 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. (R ¹ and R ² may combine to form a cyclic structure. n1 and n2 are each independently 0 or 1.) The epoxy equivalent of the epoxy resin is 200 to 800 g/eq. The epoxy resin composition according to claim 1 or 2. The epoxy resin composition according to any one of claims 1 to 3, wherein the curing agent has 0.3 to 2.0 mol of active hydrogen groups with respect to 1 mol of epoxy groups of the epoxy resin. The epoxy resin composition according to any one of claims 1 to 4, wherein the compounding amount of the inorganic filler is 10 to 60% by weight based on the total amount of the epoxy resin, the curing agent and the inorganic filler. The epoxy resin composition according to any one of claims 1 to 5, further containing a thermosetting resin other than an epoxy resin and/or a thermoplastic resin as the other resin. The epoxy resin composition according to claim 6, wherein the compounding amount of the other resin is 3 to 100 parts by mass with respect to 100 parts by mass of the epoxy resin. The epoxy resin composition according to claim 1, further comprising a nitrogen-based flame retardant. The epoxy resin composition according to claim 8, wherein the compounding amount of the nitrogen-based flame retardant is 1 to 40 parts by mass with respect to 100 parts by mass of the epoxy resin. A prepreg using the epoxy resin composition according to any one of claims 1 to 9. An insulating sheet using the epoxy resin composition according to any one of claims 1 to 9. An adhesive sheet using the epoxy resin composition according to any one of claims 1 to 9. A laminate using the epoxy resin composition according to any one of claims 1 to 9. A sealing material comprising the epoxy resin composition according to claim 1. A casting material comprising the epoxy resin composition according to any one of claims 1 to 9. A cured product obtained by curing the epoxy resin composition according to any one of claims 1 to 9.

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