JP2011208126A - Curing agent for epoxy resin, curing resin composition, and cured material of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curing agent for epoxy resin to produce a resin cured material which is excellent in high heat resistance and a low linear expansion property.SOLUTION: The curing agent for epoxy resin is represented by general formula (I) and includes a bisimide phenol compound (a) having a solubility of 0.5 wt.% or more to a ketone solvent at 60°C. Rrepresents a univalent functional group excluding a hydroxy group or a hydrogen atom. R-Reach represent a hydrogen atom, hydroxy group or a 1-10C organic group and are capable of forming a ring having ≤20C which condenses to benzene ring by binding two adjacent groups. At least one among R-Rhas a hydroxy group. Rrepresents a specific organic group. X represents a single bond such as -SO-, -O-, -CO-, -C(CF)-, -S-, or a bivalent 1-20C organic group and n is 0-3.

Description

  TECHNICAL FIELD The present invention relates to a curing agent for epoxy resins containing a bisimidephenol compound having an imide skeleton structure as an essential component, a curable resin composition using the curing agent, a cured product thereof, and a material containing the cured product.

The imide skeleton-containing epoxy resin curing agent of the present invention is suitable for use as a constituent material for electrical laminates having a high glass transition temperature and a low coefficient of thermal expansion, resin metal coatings excellent in heat resistance, and fiber reinforced composite materials. A functional resin composition can be provided.
As used herein, the electric laminate refers to a laminate used for an insulating substrate including a printed wiring board, a build-up laminate, a flexible laminate, a resist material, a sealant, and the like.
In addition, the resin-metal coating refers to a metal conductor used in an electric device / electric power device coated with a resin and insulated, and the fiber reinforced composite material refers to CFRP (carbon fiber reinforced plastic) or GFRP (GFRP ( A composite material using an epoxy resin as a matrix resin, including a glass fiber reinforced plastic).

  Epoxy resins are used in a wide range of fields such as paints, civil engineering, and electrical applications. In addition, various types of curing agents can be used for the epoxy resin, and the cured physical properties vary greatly depending on the selection of the curing agent. Therefore, the curing agent is properly used according to the purpose of each application.

  In recent years, as the use conditions of resin materials become severe, various properties required for resin materials have become more severe, and various curing agents that are generally used in applications where curing agents for epoxy resins are used. However, it has become impossible to satisfy the required characteristics sufficiently.

  For example, epoxy resin compositions using phenol novolac resin as a curing agent are used in printed wiring boards used in electrical and electronic equipment, but in recent years, equipment has become smaller, lighter, and more functional. In particular, the multilayer printed wiring board is required to have further higher multilayer, higher density, thinner, lighter weight, high reliability, moldability and the like. Thus, as the miniaturization of wiring progresses, high heat resistance and low coefficient of linear expansion have been particularly required as the characteristics of epoxy resins and epoxy resin curing agents, and are currently mainly used. The combination of an epoxy resin and a phenol novolac resin curing agent has not been sufficient in both heat resistance and linear expansion coefficient.

  On the other hand, imide skeleton-containing compounds are known to be excellent in heat resistance and low linear expansion, and imide phenol compounds into which imide groups have been introduced are electrical and electronic materials that require heat resistance and low linear expansion. It is useful as a raw material. In addition, a method using bisimidephenol as a monomer is also disclosed, and there is a description of a method of using it as a curing agent for epoxy resin (Patent Documents 1 to 4), but bisimidephenol compounds known so far Is not sufficiently soluble in common organic solvents such as ketone solvents (Patent Documents 5 to 6), and handling at the time of processing is very difficult and is subject to various restrictions.

JP-A-1-319528 Japanese Patent Laid-Open No. 2-70722 Japanese Patent Laid-Open No. 3-209858 JP 2007-91799 A US Pat. No. 5,246,751 Japanese Patent Laid-Open No. 62-292822

  The present invention provides an epoxy resin curing agent that provides a resin cured product that is superior in solvent solubility compared to conventional imide skeleton-containing epoxy resin curing agents and that has high heat resistance and low linear expansion properties, and the epoxy resin. An object of the present invention is to provide a curable resin composition that uses a resin curing agent to give a cured product having high heat resistance and low linear expansion, a cured product thereof, and a material containing the cured product. is there.

  In order to solve the above-mentioned problems, the present inventors have intensively studied. As a result, the bisimidephenol compound having a specific structure exhibits sufficient solubility in a ketone solvent, and has high heat resistance and low linear expansion. It has been found that it is excellent as a curing agent for epoxy resins that gives a cured resin having excellent properties.

  The present invention has been achieved based on such findings, and the gist thereof is as follows.

(一般式（Ｉ）において、Ｒ_１は水酸基を除く一価の官能基、または水素原子を示す。Ｒ_２〜Ｒ_５は、各々独立に、水素原子、水酸基、または炭素数１〜１０の有機基を示すが、隣接する２つの基が結合してベンゼン環に縮合する炭素数２０以下の環を形成してもよい。また、各Ｒ_２〜Ｒ_５のうちの少なくとも一つは水酸基であることにより、化合物中には２個以上の水酸基を有する。
Ｒ_６は、炭素数１〜１０の有機基を示すが、隣接する２つの基が結合してベンゼン環に縮合する炭素数２０以下の環を形成してもよい。
複数のＲ_１〜Ｒ_６は、互いに同一であってもよく、異なっていてもよい。
Ｘは、単結合、−ＳＯ_２−、−Ｏ−、−ＣＯ−、−Ｃ（ＣＦ_３）_２−、−Ｓ−、または炭素数１〜２０の二価の有機基から選ばれる基を示す。
ｎは０〜３の整数である。） [1] A curing agent for epoxy resins containing a bisimide phenol compound (a) represented by the following general formula (I) and having a solubility of 0.5% by weight or more at 60 ° C. in a ketone solvent.

(In General Formula (I), R ₁ represents a monovalent functional group other than a hydroxyl group or a hydrogen atom. R _{2 to} R ₅ each independently represents a hydrogen atom, a hydroxyl group, or an organic compound having 1 to 10 carbon atoms. Represents a group, but two adjacent groups may be bonded to each other to form a ring having a carbon number of 20 or less fused to a benzene ring, and at least one of R _{2 to} R ₅ is a hydroxyl group. Thus, the compound has two or more hydroxyl groups.
R ₆ represents an organic group having 1 to 10 carbon atoms, but two adjacent groups may be bonded to form a ring having 20 or less carbon atoms condensed with a benzene ring.
The plurality of R _{1 to} R ₆ may be the same as or different from each other.
X represents a group selected from a single bond, —SO ₂ —, —O—, —CO—, —C (CF ₃ ) ₂ —, —S—, or a divalent organic group having 1 to 20 carbon atoms. .
n is an integer of 0-3. )

[2] The composition according to [1], comprising 100 parts by weight of the bisimide phenol compound (a) and 900 parts by weight or less of the curing agent for curable resin (b) comprising a compound other than the bisimide phenol compound (a). Curing agent for epoxy resin.

[3] The epoxy resin curing agent according to [1] or [2], wherein the bisimidephenol compound (a) has a solubility of 0.5% by weight or more at 60 ° C. with respect to cyclohexanone.

[4] A curable resin composition comprising an epoxy resin and the epoxy resin curing agent according to any one of [1] to [3].

[5] The curable resin composition according to [4], further including a curing accelerator.

[6] The curable resin composition according to [4] or [5], further including a thermosetting resin other than an epoxy resin and / or a filler.

[7] The curability according to any one of [4] to [6], wherein the cured product has a glass transition temperature of 150 ° C. or higher and a linear expansion coefficient of 65 ppm / ° C. or lower at the glass transition temperature or lower. Resin composition.

[8] The curable resin composition according to any one of [4] to [7], which is used for a printed wiring board.

[9] A cured resin product obtained by curing the curable resin composition according to any one of [4] to [8].

[10] A laminate of the cured resin and the conductive metal according to [9].

[11] A resin metal covering obtained by coating a metal with the cured resin according to [9].

[12] A fiber-reinforced composite material comprising the cured resin according to [9] and reinforcing fibers.

  Since the curing agent for epoxy resins of the present invention is excellent in solubility in a ketone solvent and has high compatibility with various epoxy resins, a curable resin composition can be easily prepared. Moreover, since the curing agent for epoxy resins of the present invention has a high imide group concentration, the curable resin composition using the curing agent for epoxy resins of the present invention has a low linear expansion coefficient and heat resistance (glass transition temperature). It is excellent in molding processability and is particularly useful in electrical laminate applications where low linear expansion is required, and resin metal coatings and fiber reinforced composite materials where high heat resistance is required.

16 is a TMA chart of a cured resin obtained in Example 14.

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

  In the present invention, the “organic group” is a group containing a carbon atom, and the “functional group” is a general term for an organic group and an inorganic group such as a hydroxyl group and a halogen atom.

[1] Curing agent for epoxy resin [bisimidophenol compound (a)]
The epoxy resin curing agent of the present invention is represented by the following general formula (I), and has a solubility of 0.5% by weight or more at 60 ° C. in a ketone solvent (hereinafter referred to as “this” The bisimidephenol compound (a) ”of the invention may be referred to as an essential component.

(In General Formula (I), R ₁ represents a monovalent functional group other than a hydroxyl group or a hydrogen atom. R _{2 to} R ₅ each independently represents a hydrogen atom, a hydroxyl group, or an organic compound having 1 to 10 carbon atoms. Represents a group, but two adjacent groups may be bonded to each other to form a ring having a carbon number of 20 or less fused to a benzene ring, and at least one of R _{2 to} R ₅ is a hydroxyl group. Thus, the compound has two or more hydroxyl groups.
R ₆ represents an organic group having 1 to 10 carbon atoms, but two adjacent groups may be bonded to form a ring having 20 or less carbon atoms condensed with a benzene ring.
The plurality of R _{1 to} R ₆ may be the same as or different from each other.
X represents a group selected from a single bond, —SO ₂ —, —O—, —CO—, —C (CF ₃ ) ₂ —, —S—, or a divalent organic group having 1 to 20 carbon atoms. .
n is an integer of 0-3. )

Ordinary imide group-containing compounds, especially aromatic imide compounds, exhibit excellent physical properties due to strong cohesion due to stacking of conjugated planes containing imide groups, but have very low solvent solubility and are difficult to handle. there were.
On the other hand, the bisimide phenol compound (a) of the present invention used in the curing agent for epoxy resins of the present invention is represented by the above general formula (I), has high solubility in ketone solvents, and has various epoxy resins. Because of its high compatibility, it is possible to easily prepare curable resin compositions, and since the imide group concentration in the molecule is high, the resulting resin cured product is imparted with low linear expansion and heat resistance. It is useful as a curing agent.

{Solubility in ketone solvents}
The solubility of the bisimidephenol compound (a) of the present invention in a ketone solvent is 0.5% by weight or more at 60 ° C., preferably 3.0% by weight or more, particularly preferably 6.0% by weight or more. Most preferably, it is 8.0 weight% or more.

Here, the ketone solvent refers to a liquid having a ketone group. Among them, it is desirable that it is aprotic so as not to interfere with the reaction of bisimidephenol, for example, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisopropyl ketone, di-tert-butyl ketone, cyclopentanone, cyclohexanone. Cyclohexyl methyl ketone, acetophenone, acetylacetone and the like.
Among the above-mentioned ketone solvents, cyclohexanone is preferable, and the bisimidephenol compound (a) has a solubility in cyclohexanone of preferably 0.5% by weight or more at 60 ° C., and 3.0% by weight or more. Is more preferably 6.0% by weight or more, and most preferably 8.0% by weight or more.

  In addition, the measuring method of the solubility with respect to the ketone solvent of the bisimide phenol compound (a) of this invention is as follows.

<Method for measuring solubility>
The sample bottle is charged with the bisimidephenol compound (a) and the ketone solvent, and the solubility when heated in an oil bath at 60 ° C. for 2 hours is visually confirmed while occasionally shaking by hand. Start measurement from a high concentration. If there is any undissolved material, add a small amount of solvent to lower the concentration, and use the concentration at the time of complete dissolution as solubility.

{Explanation of solubility expression}
Although the details of the reason why the bisimidephenol compound (a) of the present invention can be excellent in solubility in a solvent are not clear, it is estimated as follows.
(1) In the general formula (I), by introducing a substituent R ₁ having an appropriate size at the ortho position of the imide group, the conjugate plane containing the imide group has a twist, and the stacking structure between molecules is moderate. Be inhibited.
(2) In the general formula (I), the crystallinity is lowered when both ortho positions of the imide group are asymmetric (R ₁ ≠ R ₅ ).
(3) In the general formula (I), when a trifluoromethylene group is introduced into the linking group moiety X, the intermolecular interaction of the phthalic acid moiety is moderately weakened by the electrostatic repulsion of the fluorine atom. Further, the solubility can be further improved as compared with the case of only twisting of the conjugate plane.

In the bisimide phenol compound (a) of the present invention, good solvent solubility can be exhibited by allowing these factors to act in concert.
However, if the substituent R ₁ that causes twisting is too large, stacking between molecules, which is a feature of the imide compound, may be completely inhibited, and sufficient physical properties may not be obtained. R ₁ is preferably limited to an appropriate size.

The substituent R ₁ satisfying the above conditions represents a monovalent functional group in which | α | defined below is 45 ° or more and 90 ° or less, and R ₅ is a hydrogen atom or defined below | α | represents a monovalent functional group of 0 ° or more and less than 45 °.
Therefore, in order to ensure the solvent solubility of the bisimidephenol compound (a) of the present invention, the bisimidephenol compound (a) of the present invention is represented by the following general formula (I), wherein R ₁ is defined as follows: | Α | is a monovalent functional group in which 45 ° or more and 90 ° or less, and R ₅ is a hydrogen atom or a monovalent functional group in which | α | defined below is 0 ° or more and less than 45 ° It is preferably a functional group.

{Definition of ||
| Α | is the absolute value of the dihedral angle α formed by two conjugate planes when the most stable structure based on theoretical calculation is calculated in the structure represented by the following formula (I-1).

（式中、ＲはＲ_１またはＲ_５に該当する。）

(In the formula, R corresponds to R ₁ or R _5. )

Here, the theoretical calculation of the dihedral angle is performed by using the AM1 method using “Microsoft Windows XP Professional Version 2002 Service Pack2” as the OS and “Gaussian03 x86-Win32 Rev.B.05” as the software. This is done by calculating the most stable structure by specifying “opt = verytight” as an option).
α is the following four types of (1) to (4) formed by four adjacent atoms, C (imido carbonyl carbon) -N (imide nitrogen) -C (aromatic ring) -C (aromatic ring) The absolute value of the dihedral angle is the smallest. C ^{1 to} C ⁵ are represented by the following formula (I-Ia).
(1) C ¹ -C ² -N-C ⁴
(2) C ¹ -C ² -N-C ^{5
(3) C 3 -C 2 -N} -C 4
^{(4) C 3 -C 2 -N} -C 5

（式中、ＲはＲ_１またはＲ_５に該当する。）

(In the formula, R corresponds to R ₁ or R _5. )

{Description of general formula (I)}
Hereinafter, in the general formula (I), the bisimide phenol compound (a) of the present invention represented by the general formula (I) will be exemplified particularly in the case where R ₁ and R ₅ are the above-mentioned preferred groups. Will be explained.

<R ₁ >
In the general formula (I), R ₁ is preferably a monovalent functional group other than a halogen atom, a hydrogen atom, and a hydroxyl group, wherein the above | α | is 45 ° or more and 90 ° or less. The lower limit of | α | of R ₁ is preferably 48 °, more preferably 51 °, because a decrease in solvent solubility due to overlap between molecules hardly occurs. On the other hand, the upper limit of | α | is preferably 75 °, more preferably 60 °, because the substituent has an appropriate size at which stacking between molecules, which is a characteristic of an imide compound, occurs.

R ₁ satisfies the above | α | and easily develops the imide group concentration in the carbonimidophenol molecule and the physical properties expected of the imide compound, that is, the molecular weight is not excessively large. The organic group having 1 to 10 carbon atoms is considered to have sufficient group content and the physical properties expected of the imide compound are not impaired by the intermolecular interaction being inhibited by steric hindrance. Is preferable, an organic group having 1 to 3 carbon atoms is more preferable, and an organic group having 1 to 2 carbon atoms is particularly preferable.

Specific examples of R ₁ include a hydrocarbon group, an aromatic group, an acyl group (aldehyde, ketone), a carboxyl group, an alkoxycarbonyl group (ester), an alkoxyl group, an allyloxyl group, an optionally substituted amino group, An optionally substituted carboxamide group, mercapto group, alkylthio group, arylthio group, sulfinyl group, sulfonyl group, sulfo group, trialkylsilyl group and the like can be mentioned. Among them, since | α | is in a suitable range, a linear or secondary hydrocarbon group, acyl group (aldehyde, ketone), carboxyl group, alkoxycarbonyl group (ester), alkoxyl group, allyloxyl group, substituted Amino group, substituted carboxamide group, mercapto group, alkylthio group, arylthio group, sulfinyl group, sulfonyl group, sulfo group are preferred, and in particular, linear hydrocarbon group, acyl group excluding formyl group, carboxyl group, Alkoxycarbonyl groups (esters), substituted amino groups, sulfonyl groups and sulfo groups are preferred.

In addition, the functional groups having | α | of 45 to 90 ° are shown in Table 1, and among these functional groups particularly suitable as R ₁ (| α | = 48 to 75 °), Table 2 together with the | α | (In the following, Ph represents a phenyl group, Me represents a methyl group, Et represents an ethyl group, Pr represents a propyl group, and Bu represents a butyl group).

Of the functional groups shown in Table 2, R ₁ is particularly preferably those shown in Table 3 below (| α | = 51-60 °).

<R ₅ >
In the general formula (I), R ₅ is preferably a hydrogen atom or a monovalent functional group other than a halogen atom having the above | α | of 0 ° or more and less than 45 °. | Α | is 0 ° when R ₅ is a substituent having Lewis acidity that strongly interacts with the carbonyl oxygen of the imide group. In such a case, the formation of a dihedral angle by R ₁ is R ₅ is inhibited, since it may not be able to ensure a sufficient solubility, | alpha | lower limit is preferably 10 °, more preferably 20 °. In addition, since a substituent that causes a large twist may further increase the dihedral angle generated by R ₁ and deviate from the preferred range, the upper limit of | α | is preferably 43 °.

Specific examples of R ₅ include sterically small hydrogen atoms or functional groups such as hydrogen atoms or functional groups represented by | α | in Table 4 below. Among these, steric ones such as hydrogen atoms or hydroxyl groups In particular, a hydrogen atom or a functional group having a small Lewis acidity is preferable.

<R _{2 to} R ₄ >
In the general formula (I), R _{2 to} R ₄ each independently represent a hydrogen atom, a hydroxyl group, or a monovalent organic group having 1 to 10 carbon atoms, and among R _{2 to} R ₄ , adjacent 2 A ring having 20 or less carbon atoms in which two groups are bonded to each other and condensed to a benzene ring may be formed.
The organic group having 1 to 10 carbon atoms as R ₂ to R _4, is not particularly limited, since the relative imide group content the molecular weight of each group is large is reduced, is the number 3 or less organic group having a carbon It is preferable.

Specific examples of R _{2 to} R ₄ are each independently a hydrogen atom, a hydrocarbon group, an aromatic group (including a heterocyclic group), a carbonyl group (aldehyde, ketone, ester, amide, etc.), an alkoxy group, or an acyloxy group. Group, alkylthio group, aryloxy group, dialkylamino group. When R _{2 to} R ₄ are hydrocarbon groups, they may have a substituent as long as the carbon number is 10 or less. Examples of the substituent include a heterocyclic group, a carbonyl group, a dialkylamino group, an alkoxy group, Examples include an acyloxy group, an alkylthio group, an aryloxy group, and a silyl group.

R _{2 to} R ₄ are each independently preferably a hydrogen atom, a hydroxyl group or a methyl group.

<Hydroxyl group of R _{2 to} R ₅ >
In the bisimide phenol compound (a) of the present invention, at least one of R _{2 to} R ₅ needs to be a hydroxyl group.
This is because when the epoxy resin is cured using the bisimide phenol compound (a) of the present invention as a curing agent for an epoxy resin, the curing does not proceed without a reactive substituent, and the most versatile. This is because the highly reactive substituent is a hydroxyl group.
However, since it is difficult to synthesize the bisimidephenol compound (a) itself when there are too many hydroxyl groups in one molecule, 1 to 2 benzene rings bonded to the imide group in one molecule are preferred, preferably It is desirable that one hydroxyl group is bonded to each other.
Moreover, the bisimide phenol compound (a) of the present invention has a phenolic hydroxyl group equivalent of 200 to 600 g / eq. , In particular 250-400 g / eq. It is preferable that

<R ₆ >
In the general formula (I), each R ₆ independently represents a monovalent organic group having 1 to 10 carbon atoms, and when R ₆ is adjacent to each other on one benzene ring, the two adjacent R ₆ may be bonded to each other to form a ring having 20 or less carbon atoms, which is condensed with a benzene ring.
R ₆ is not particularly limited as long as it is an organic group having 1 to 10 carbon atoms. However, when the molecular weight of each group increases, the relative imide group content decreases, and thus the organic group has 3 or less carbon atoms. It is preferable.

Specific examples of R ₆ each independently include a hydrocarbon group, an aromatic group (including a heterocyclic group), a carbonyl group (aldehyde, ketone, ester, amide, etc.), and a dialkylamino group. When R ₆ is a hydrocarbon group, it may have a substituent as long as it has 10 or less carbon atoms. Examples of the substituent include a heterocyclic group, a carbonyl group, a dialkylamino group, an alkoxy group, an acyloxy group, An alkylthio group, an aryloxy group, and a silyl group are mentioned.

<X>
In the general formula (I), X is a single bond, —SO ₂ —, —O—, —CO—, —C (CF ₃ ) ₂ —, —S—, or optionally substituted 1 to 20 carbon atoms. The divalent organic group of is shown. In the case where X is a divalent organic group, the imide group content is relatively lowered when the molecular weight is increased. Therefore, an organic group having 1 to 10 carbon atoms is preferable, and an organic group having 1 to 3 carbon atoms. It is preferable. Specific examples of the divalent organic group having 1 to 3 carbon atoms include a methylene group, a 2,2-propylidene group, and an oxymethylene group.

X is particularly preferably a single bond, an oxymethylene group, —O—, —CO—, —SO ₂ — or C (CF ₃ ) ₂ —.

<N>
In the general formula (I), n is an integer of 0 to 3, but when n is large and the molecular weight of the bisimide phenol compound (a) of the present invention is increased, the relative imide group content is decreased. Is preferably 0 or 1.

<Symmetry>
In the bisimide phenol compound (a) of the present invention, R _{1 to} R ₆ bonded to the benzene ring portions of the left and right ring structures connected by the linking group X and n representing the number of R ₆ are the same on the left and right. However, they may be different, but the same is preferable because the symmetry of the molecule is good and the cohesive force characteristic of imide is not impaired when the molecular weight is increased.

{Molecular weight}
The lower limit of the molecular weight of the bisimidephenol compound (a) of the present invention is 504, and the upper limit thereof is preferably 1200 or less, particularly 1000 or less, and particularly preferably 800 or less.
If the molecular weight of the bisimidephenol compound (a) of the present invention is excessively small, the molecular design of the bisimidephenol compound (a) of the present invention is impossible, and conversely if excessively large, the bisimidephenol of the present invention is impossible. The imide group content in the compound (a) becomes small, which is not preferable.

{Imido group content}
The imide group content of the bisimidephenol compound (a) of the present invention (molar amount of imide groups per gram of the bisimidephenol compound (a) of the present invention) is high in heat resistance and low linear expansion properties. Since it can be useful as an excellent curing agent for epoxy resins of various materials, it is preferably 0.22 mmol / g or more, particularly 0.8 mmol / g or more, and particularly preferably 1.5 mmol / g or more. The maximum value of the imide group content is theoretically 4.0 mmol / g.

The structure of the bisimidephenol compound (a) of the present invention such as imide group content is as follows: ¹ H-NMR (nuclear magnetic resonance spectrum analysis method: heavy dimethyl sulfoxide solvent), IR (infrared absorption spectrum method), MS (mass spectrometry method) ) Can be confirmed.

{Preferred example}
Examples of the bisimide phenol compound (a) that is particularly suitable as the bisimide phenol compound (a) of the present invention and that has a high solvent solubility include the following, and the bisimide phenol compound (a) of the present invention. Is not limited to the following.

[Curing agent for curable resin (b) comprising compound other than bisimidephenol compound (a) of the present invention]
The curing agent for epoxy resin of the present invention may consist only of the above-described bisimidephenol compound (a) of the present invention, and together with the bisimidephenol compound (a) of the present invention, the bisimidephenol of the present invention. It may contain a curable resin curing agent (b) (hereinafter sometimes referred to as “other curing agent (b)”) comprising a compound other than the compound (a).
Examples of the other curing agent (b) include polyhydric phenols, amine compounds, acid anhydrides and the like, and specifically, those exemplified below can be used.

  Other curing agents (b) include, for example, bisphenol A, bisphenol F, bisphenol AD, hydroquinone, resorcin, methylresorcin, biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, thiodiphenols, phenol novolac resin, cresol Various polyphenols such as novolac resin, phenol aralkyl resin, terpene phenol resin, dicyclopentadiene phenol resin, bisphenol A novolac resin, naphthol novolac resin, biphenylphenol resin, brominated bisphenol A, brominated phenol novolac resin, Various phenols and benzaldehyde, hydroxybenzaldehyde, crotonaldehyde, glyoxal, etc. Polyphenolic resins obtained by condensation reaction with various aldehydes, various phenolic resins such as heavy oil or pitch, co-condensation resin of phenols and formaldehyde, these various phenols (resins) Active ester compounds obtained by esterifying all or part of the phenolic hydroxyl group of benzoate or acetate, acids such as methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, methylnadic acid Examples include anhydrides, amines such as diethylenetriamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylsulfone, dicyandiamide, aliphatic polyamine, and polyamide.

A cationic polymerization initiator can also be used as the other curing agent (b). The cationic polymerization initiator includes an active energy ray cationic polymerization that generates a cationic species or a Lewis acid by an active energy ray. An initiator or a thermal cationic polymerization initiator that generates a cationic species or a Lewis acid by heat can be used.
Specifically, phosphine compounds such as triphenylphosphine, phosphonium salts such as tetraphenylphosphonium tetraphenylborate, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2 Imidazoles such as undecylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-dicyano-6- [2-methylimidazolyl- (1)]-ethyl-S-triazine, 1 -Cyanoethyl-2-undecylimidazolium trimellitate, 2-methylimidazolium isocyanurate, 2-ethyl-4-methylimidazolium tetraphenylborate, 2-ethyl-1,4-dimethylimidazolium Imidazolium salts such as tetraphenylborate, 2,4-6-tris (dimethylamino) Amines such as til) phenol, benzyldimethylamine, ammonium salts such as triethylammonium tetraphenylborate, 1,5-diazabicyclo (5,4,0) -7-undecene, 1,5-diazabicyclo (4 , 3,0) -5-nonene and the like. Further, tetraphenylborate, phenol salt, phenol novolak salt, 2-ethylhexanoate and the like of these diazabicyclo compounds, triflic acid salt, boron trifluoride ether complex compound, metal fluoroboron complex salt, bis (perfluoroalkyl sulfonyl) methane metal salts, aryl diazonium compounds, aromatic onium salts, periodic table dicarbonyl chelate of a IIIa~Va group elements, thiopyrylium salts, MF ₆ ^- anion (where M is phosphorus, antimony Periodic group VIb elements, arylsulfonium complex salts, aromatic iodonium complex salts, aromatic sulfonium complex salts, bis [4- (diphenylsulfonio) phenyl] sulfide-bis-hexafluorometal salts (For example, phosphate, arsenate, antimonate, etc.), Reel sulfonium complex salts, can be used aromatic sulfonium or iodonium salts of halogen-containing complex ions.

  In addition, mixed ligand metal salts of iron compounds and silanol-aluminum complexes can also be used. Some of these salts are FX-512 (3M), UVR-6990 and UVR-6974 (Union Carbide), UVE-1014 and UVE-1016 (General Electric) ), KI-85 (Degussa), SP-150 and SP-170 (Asahi Denka) and Sun-Aid SI-60L, SI-80L and SI-100L (Sanshin Chemical Co., Ltd.). .

  As the thermal cationic polymerization initiator, a cationic or protonic acid catalyst such as a triflic acid salt, a boron trifluoride ether complex compound, boron trifluoride or the like can be used. A preferable thermal cationic polymerization initiator is a triflate, for example, diethylammonium triflate, triethylammonium triflate, diisopropylammonium triflate, ethyl diisopropylammonium triflate available from 3M as FC-520, etc. (Many of these are described in Modern Coatings published in October 1980 by RR Alm).

  On the other hand, among aromatic onium salts used as active energy ray cationic polymerization initiators, there are those that generate cationic species by heat, and these can also be used as thermal cationic polymerization initiators.

  These other hardening | curing agents (b) may be used individually by 1 type, and may use 2 or more types together.

[Formulation of curing agent for epoxy resin]
The form of the curing agent for epoxy resin of the present invention varies depending on the presence or absence of the other curing agent (b), the type of the other curing agent (b) to be used, and the blending amount thereof. It may be solid.

  Moreover, the compounding quantity of the bisimide phenol compound (a) of this invention and the other hardening | curing agent (b) in the hardening | curing agent for epoxy resins of this invention is the bisimide phenol compound (a) and other hardening of this invention to be used. Although it depends on the type of the agent (b), it is 0 to 900 parts by weight of the other curing agent (b) with respect to 100 parts by weight of the bisimide phenol compound (a) of the present invention, preferably the bisimide phenol compound of the present invention. (A) 0 to 400 parts by weight of the other curing agent (b) with respect to 100 parts by weight, more preferably 5 to 300 parts by weight of the other curing agent (b) with respect to 100 parts by weight of the bisimide phenol compound (a) of the present invention. Parts, most preferably in the range of 10 to 200 parts by weight of the other curing agent (b) with respect to 100 parts by weight of the bisimidephenol compound (a) of the present invention.

In the epoxy resin curing agent of the present invention, by blending another curing agent (b), the compatibility in the curable resin composition is improved, and the workability is improved. If the amount of the bisimidephenol compound (a) is too small, the imide group content in the curable resin composition obtained using the epoxy resin curing agent of the present invention is lowered. The effect of the invention cannot be expected.
The curing agent for epoxy resin of the present invention comprising the bisimidephenol compound (a) of the present invention and the above-mentioned other curing agent (b) blended as necessary is the imide group content (curing agent for epoxy resin). In order to achieve the object of the present invention, the molar amount of imide groups per gram) is preferably 0.1 mmol / g or more, particularly 0.4 mmol / g or more, particularly 0.8 mmol / g or more.

[2] Curable resin composition The curable resin composition of the present invention includes the above-described curing agent for epoxy resin of the present invention and an epoxy resin, and if necessary, a thermosetting resin other than the epoxy resin. , A curing accelerator, a filler, a solvent, and other components may be included.

[Epoxy resin]
There is no restriction | limiting in particular as an epoxy resin which the curable resin composition of this invention can contain, For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, imide skeleton containing epoxy Resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, epoxy resin obtained by reacting epihalohydrin with condensed novolaks of phenols and glyoxal, hydroxybenzaldehyde, crotonaldehyde, etc. Glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, chain aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic ether Various epoxy resins such as carboxymethyl resins. In addition, it is preferable that the imide frame | skeleton containing epoxy resin here is an epoxy resin which uses the bisimide phenol compound (a) of this invention as a raw material.

  These epoxy resins are particularly used as semiconductor encapsulants, in the range of weight average molecular weight Mw of 100 to 1,000, epoxy equivalent of 100 to 1,000 g / eq. Each preferably has a weight average molecular weight Mw of 1,000 to 90,000 and an epoxy equivalent of 500 to 100,000 g / eq.

  These epoxy resins may be used individually by 1 type, and may use 2 or more types together.

[Content of curing agent for epoxy resin]
The content of the curing agent for epoxy resin of the present invention in the curable resin composition of the present invention varies depending on the type of curing agent used, but is usually 0.5 to 200 parts by weight with respect to 100 parts by weight of the total epoxy resin. , Preferably in the range of 1 to 150 parts by weight. When the content of the curing agent for epoxy resin of the present invention in the curable resin composition of the present invention is too large, mixing with the resin is worsened, and when it is too small, the relative imide group content of the whole composition is decreased. Absent.
In addition, you may use the hardening | curing agent for epoxy resins of this invention as a mixture with an epoxy resin etc. previously.

[Curing accelerator]
As the curing accelerator, any of those used in general epoxy resin compositions can be used. Examples include amines such as benzyldimethylamine and various imidazole compounds, and tertiary phosphines such as triphenylphosphine. Can be mentioned. These may be used alone or in combination of two or more.

  The curing accelerator is preferably blended in an amount of 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the total epoxy resin.

[Thermosetting resins other than epoxy resins]
Examples of thermosetting resins other than epoxy resins include cyanate ester resins, thermosetting polyimide resins, thermosetting polyphenylene ether resins, and the like. These may be used alone or in combination of two or more.

  When the curable resin composition of this invention contains these thermosetting resins, it is preferable that the content shall be 40 weight part or less with respect to 100 weight part of all the epoxy resins, for example, 10-30 weight part. When the curable resin composition contains a thermosetting resin other than an epoxy resin, the water-absorbing property can be reduced. However, if the content is too large, the effect of using the epoxy resin curing agent of the present invention can be reduced. Furthermore, the properties of the epoxy resin may be impaired.

[solvent]
Examples of the solvent that can be contained in the curable resin composition of the present invention include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone, aromatics such as toluene and xylene, and esters such as ethyl acetate. And ethers such as ethylene glycol monomethyl ether, amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and alcohols such as methanol and ethanol. In order to improve moldability, it is preferable to use a ketone solvent and an amide solvent with good solubility. These solvents may be used alone or in combination of two or more.

  The amount of the solvent used is appropriately determined according to the purpose of use of the curable resin composition. For example, when a prepreg is prepared by impregnating a glass fiber nonwoven fabric with a curable resin composition in a laminate application, a solvent other than the solvent is used. It is used so that the total solid content concentration in the curable resin composition is about 40 to 70% by weight, and in build-up applications, the total solid content concentration in the curable resin composition other than the solvent is 30 to 30%. It is used so that it may become about 75 weight%.

[filler]
The filler that can be contained in the curable resin composition of the present invention may be an inorganic filler or an organic filler. Examples of the inorganic filler include metal oxides such as aluminum oxide and magnesium oxide, Silicon compounds such as powdered silica, fused silica and crystalline silica, transparent fillers such as glass beads, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, others, calcium carbonate, kaolin, mica, quartz powder, graphite, disulfide And molybdenum. Examples of the organic filler include cellulose fiber. These may be used alone or in combination of two or more.

  The inorganic filler has a mean particle size of about 1 to 30 μm because the surface shape of the cured product is deteriorated if the particle size is too large, and if the particle size is too small, it tends to aggregate and deteriorate dispersibility. .

  When the curable resin composition of the present invention contains these fillers, the content thereof is usually 10 to 98% by weight with respect to the total solid content in the total curable resin composition. Is preferably 60 to 98% by weight, more preferably 80 to 98% by weight. Moreover, as an electrical laminated board use, 10 to 60 weight% is preferable and 20 to 50 weight% is more preferable. When the curable resin composition contains a filler, the effects of improving flame retardancy, low water absorption, and low linear expansion coefficient can be obtained. However, if the content is too large, moldability and the like may be impaired. There is.

[Other ingredients]
The curable resin composition of the present invention includes other anti-UV agents for improving storage stability, plasticizers, silane coupling agents, coupling agents such as titanate coupling agents, colorants and pigments, flame retardancy Various additives that can be blended in a normal epoxy resin composition, such as a halogen-based, phosphorus-based, nitrogen-based, silicon-based flame retardant, glass fiber reinforcing agent, etc. It can mix | blend in the range which does not impair the objective.

  The curable resin composition of the present invention can be prepared by mixing predetermined amounts of the above-described blending components.

[Imide group content in curable resin composition]
Since the imide group content (molar amount of imide groups per 1 g of the composition) of the curable resin composition of the present invention containing the epoxy resin curing agent of the present invention contributes to a decrease in the linear expansion coefficient, it is preferable that 05 mmol / g or more, particularly 0.2 mmol / g or more, particularly 0.5 mmol / g or more is preferable.
In order to increase the imide group content in the curable resin composition, it is preferable that the epoxy resin also contains an imide skeleton.

[Usage]
The curable resin composition of the present invention can be effectively used in various fields such as adhesives, paints, civil engineering and building materials, insulating materials for electric / electronic parts, etc. Due to its expandability and molding processability, it can be suitably used for a new type printed wiring board such as a multilayer electric laminate or a build-up method. In particular, use in the form of a resin-coated copper foil, an adhesive film, or the like used as a build-up method multilayer printed wiring board material is preferable. It can also be used for flexible laminate applications, resist materials, sealing materials and the like. In addition, it can be used for the insulation coating treatment of electric wires and various composite materials (including CFRP and the like).

[3] Cured resin The cured resin of the present invention is obtained by curing the curable resin composition of the present invention.
Although the hardening method of the curable resin composition of this invention changes also with the compounding component and compounding quantity in curable resin composition, the heating conditions for 60 to 180 minutes are normally mentioned at 100-200 degreeC. This heating may be performed by a two-stage treatment of primary heating at 100 to 130 ° C. for 10 to 30 minutes and secondary heating at 150 to 200 ° C. that is 50 to 80 ° C. higher than the primary heating temperature for 60 to 150 minutes. This is preferable from the viewpoint of reducing curing failure.

  The resin cured product of the present invention is used for applications requiring high heat resistance such as electric laminates, resin metal coatings, and fiber reinforced composite materials, and therefore has a glass transition temperature of 150 ° C. or higher, particularly 200 ° C. or higher. It is preferable that Further, since it is used for applications such as build-up wiring boards that require a high degree of dimensional stability, the coefficient of linear expansion below its glass transition temperature is preferably 65 ppm / ° C. or less, especially 55 ppm / ° C. or less.

  In addition, the glass transition temperature and linear expansion coefficient of resin cured material are measured by the method shown by the term of the below-mentioned Example.

[4] Laminate The laminate of the present invention is a laminate of the cured resin of the present invention and a conductive metal obtained by curing the curable resin composition of the present invention, preferably in a build-up laminate. It is a film with conductive metal foil as a build-up layer.

  As the conductive metal foil of the film with the conductive metal foil, a metal foil such as copper or aluminum is used, and the thickness is usually about 9 to 19 μm. Moreover, as a film, the thing about 40-90 micrometers thick is used normally.

  As shown in the Examples section below, this laminate was prepared by using a solvent to prepare a coating solution in which the curable resin composition of the present invention was adjusted to an appropriate viscosity, and using this coating solution as a metal such as copper foil. It can be manufactured by applying to a foil and semi-curing by heating under the above-mentioned primary heating conditions. The laminated body in which the resin side is semi-cured is laminated by the necessary number of sheets on the core substrate, and then heated under the above-mentioned secondary heating conditions under a pressure of about 2 to 5 MPa to be completely cured and integrated, It can be a printed wiring board.

[5] Resin metal coating The resin metal coating of the present invention is obtained by coating a metal, particularly a conductive metal, with the resin cured product of the present invention obtained by curing the curable resin composition of the present invention. Preferably, it is a resin metal coating for insulation treatment in electric wires. As the conductive metal of the resin metal coating, an electric wire such as copper or aluminum is used.

[6] Fiber Reinforced Composite Material The fiber reinforced composite material of the present invention includes a cured resin and a reinforced fiber. For example, a fiber reinforced composite obtained by impregnating a reinforced resin with the curable resin composition of the present invention. It is obtained by curing the prepreg. This fiber reinforced composite prepreg is manufactured by impregnating a reinforced resin composition of the present invention into a reinforcing fiber such as glass fiber and semi-curing it under a predetermined heating / pressurizing condition, as shown in the Examples section below. can do.

  Examples of such fiber reinforced composite materials include composite materials such as CFRP and GFRP in aviation materials and sports materials, and carbon fibers, glass fibers, and the like are used as the reinforcing fibers.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

  In addition, the detail of the component used for preparation of the hardening | curing agent for epoxy resins and curable resin composition below is as follows.

[Bisimidophenol compound (a) of the present invention]

[Other bisimidophenol compounds]

  The solubility (60 ° C.) in cyclohexanone of the bisimide phenol compounds a to d is as shown in Table 5. The solubility of bisimidephenol compounds a to d in cyclohexanone was carried out by the method described in “Method for measuring solubility”.

[Other curing agent (b)]
e: jER cure DICY7 (trade name of Japan Epoxy Resin Co., Ltd.,
Dicyandiamide)
f: jER cure YLH129 (Japan Epoxy Resin Co., Ltd. trade name,
Bisphenol type novolak resin, phenolic hydroxyl group equivalent: 117 g / eq)
g: Resitop PSM-6200 (trade name of Gunei Chemical Co., Ltd.)
Phenol novolac resin, phenolic hydroxyl group equivalent: 103 g / eq)
h: Methyl nadic acid anhydride (Wako Pure Chemical Industries, Ltd. reagent,
Acid anhydride equivalent: 178 g / eq. )
i: Diaminodiphenylsulfone (Wako Pure Chemical Industries, Ltd. reagent)
Active hydrogen equivalent: 62 g / eq. )

[Epoxy resin]
j: jER 828 (Japan Epoxy Resin Co., Ltd. trade name,
Bisphenol A type epoxy resin, epoxy equivalent: 186 g / eq. ,
(Saponifiable chlorine concentration: 40 ppm)
k: jER YX4000 (Japan Epoxy Resin Co., Ltd. trade name,
Tetramethylbiphenyl type epoxy resin, epoxy equivalent: 186 g / eq. ,
(Saponifiable chlorine concentration: 40 ppm)
l: jER157S70 (trade name of Japan Epoxy Resin Co., Ltd.,
Bisphenol A novolac type epoxy resin, epoxy equivalent: 210 g / eq. )
m: jER 1032S50 (Japan Epoxy Resin Co., Ltd. trade name,
Trisphenol methane type epoxy resin, epoxy equivalent: 175 g / eq. )
n: jER 604 (Japan Epoxy Resin Co., Ltd. trade name,
Glycidylamine type polyfunctional epoxy resin, epoxy equivalent: 119 g / eq. )
o: Reaction product of epoxy resin represented by k above and bisimide phenol represented by a above (epoxy equivalent: 600 g / eq.)
p: YX6954BH30 (trade name of Japan Epoxy Resin Co., Ltd., special high molecular weight epoxy resin, weight average molecular weight Mw .: 39,000, epoxy equivalent: 13,000 g
/ Eq.)
q: Reaction product of epoxy resin shown in k above and bisimide phenol shown in a above (weight average molecular weight Mw .: 33,000, epoxy equivalent: 14,000 g / eq.)

[Thermosetting resins other than epoxy resins]
AroCy B-30: Huntsuman Co., Ltd. trade name,
Bisphenol A dicyanate resin

[filler]
B103: Nippon Light Metal Co., Ltd. trade name, aluminum hydroxide, average particle size 8 μm

[Examples 1 to 6, Comparative Example 1]
In the formulation shown in Table 5, the bisimidephenol compound (a) or other bisimidephenol compound and the other curing agent (b) are placed in a heat-resistant reaction vessel with a stirrer (however, in Example 6, the bisimidephenol compound) (A) only) Stirring was performed at 100 to 150 ° C. in a nitrogen gas atmosphere to obtain a curing agent for epoxy resin.
The imide group content of this epoxy resin curing agent was as shown in Table 5.

[Examples 7 to 14 and Comparative Examples 2 to 3]
Commercially available epoxy resins, and epoxy resin curing agents obtained in Examples 1 to 6 and Comparative Example 1 were used as epoxy resin curing agents, and 2-ethyl-4-methylimidazole or triphenylphosphine as curing accelerators. (In Example 8, another thermosetting resin, and in Example 13, further a filler) were blended in the combinations shown in Table 6 to prepare various curable resin compositions.
About the obtained curable resin composition, the following property analysis was performed and the result was shown in Table 6.

{Imido group content in curable resin composition}
It was calculated as the molar amount of imide groups per 1 g of the blended composition.

{Glass transition temperature and linear expansion coefficient of cured resin}
<Creation of cured resin>
A cured resin was prepared by the following curing methods I and II.
In Comparative Example 2, since the solubility of the curing agent prepared in Comparative Example 1 was low and mixing with other components was difficult, a uniform cured product could not be prepared and could not be evaluated.

Curing method I: epoxy equivalent 5,000 g / eq. Less than (in the case of Examples 7 to 10, 12 and Comparative Example 2)
After mixing the epoxy resin and the curing agent at a temperature of 100 to 200 ° C. for 5 minutes at the blending ratio shown in Table 6 (in addition to other thermosetting resins in Example 8), the curing accelerator is quickly mixed. Thus, a curable resin composition was obtained. The curable resin composition was degassed under reduced pressure, poured into a mold, and heated at 120 to 200 ° C. for 2 to 5 hours to obtain a cured resin.

Curing method II: epoxy equivalent 5,000 g / eq. The above (in the case of Examples 13 to 14 and Comparative Example 2)
An epoxy resin, a curing agent, and a curing accelerator are mixed at a blending ratio shown in Table 6 to prepare a varnish (and a filler in Example 13), and a PTFE tape (Chukou Chemical Co., Ltd.) using an applicator having a slit width of 300 μm. Kogyo Co., Ltd .: Chuko Flow (registered trademark) Skived Tape MSF-100) draws a coating film, holds it at 170 ° C. for 30 minutes in a hot air drier, and further holds it at 200 ° C. for 90 minutes. A cured resin having a thickness of 100 μm was obtained.

<Measurement of glass transition temperature and linear expansion coefficient>
The glass transition temperature and linear expansion coefficient (average value at 30 to 150 ° C.) of the obtained resin cured product were measured by the following methods.
Using the “TMA / SS6100 device” manufactured by SII Nanotechnology, Inc., the temperature was increased from 20 to 250 ° C. at 5 ° C./min in the compression / expansion mode and the tensile mode, and the average linear expansion coefficient of 30 to 150 ° C. And the glass transition temperature was measured.
In addition, the figure shows the TMA chart of the cured resin product of Example 14.

{Glass transition temperature and linear expansion coefficient of prepreg}
<Preparation of prepreg (Example 11 only)>
A varnish was prepared at a blending ratio shown in Example 11 of Table 6 and impregnated into a glass reinforced fiber cloth (Style 7628: trade name of Asahi Schavel Co., Ltd., treatment AS750, thickness 0.180 mm), followed by drying at 150 ° C. The impregnated cloth was dried in a chamber for 8 minutes to obtain a B-stage prepreg.

<Measurement of linear expansion coefficient and glass transition temperature>
The glass transition temperature and linear expansion coefficient (average value at 30 to 150 ° C.) of the obtained prepreg were measured by the following methods.
Using a “TMA / SS6100 device” manufactured by SII Nanotechnology Co., Ltd., in a film tension mode, from 20 ° C. to 250 ° C., 5 ° C./min. The average linear expansion coefficient and glass transition temperature of 30 ° C. to 150 ° C. were measured.

{Copper foil peel strength}
<Creation of laminated body (Example 14, Comparative Example 3)>
Using varnishes of the blending ratios shown in Example 14 and Comparative Example 3 in Table 6, respectively, using a 300 μm applicator, copper foil (F3-WS: Furukawa Circuit Foil Co., Ltd. trade name, electrolytic copper foil, thickness 18 μm ) Draw a coating film on it and hold it at 170 ° C. for 30 minutes in a hot air dryer to create a B-stage semi-cured resin with copper foil with a thickness of 60 to 180 μm. This B-stage semi-cured resin with copper foil Two sheets were stacked and held at 200 ° C. and a pressure of 2.9 MPa for 90 minutes with a hot press machine to prepare a cured resin laminate with copper foil.

<Preparation of Resin Metal Coating (Example 14, Comparative Example 3)>
A varnish was prepared at a blending ratio shown in Example 14 of Table 6, and a coating film was formed on a copper foil (Furukawa Circuit Foil Co., Ltd., F3-WS electrolytic copper foil, thickness 18 μm) using a 300 μm applicator. Then, it was held at 200 ° C. for 90 minutes with a hot air dryer to prepare a resin metal coating of a cured resin with a copper foil having a thickness of 60 to 100 μm.
Moreover, a varnish was created with the compounding ratio shown in Comparative Example 3 in Table 6, and using a 300 μm applicator, on a copper foil (F3-WS: Furukawa Circuit Foil Co., Ltd., electrolytic copper foil, thickness 18 μm). The coated film was drawn and held at 170 ° C. for 30 minutes with a hot air dryer, and further held at 200 ° C. for 90 minutes to prepare a resin metal coating of a cured resin with copper foil having a thickness of 60 to 100 μm.

<Measurement of copper foil peel strength>
The laminate and the resin metal coating were measured according to JIS C6481.

  From the above results, it can be seen that the curing agent for epoxy resin of the present invention is excellent in heat resistance and gives a cured product of epoxy resin with low linear expansion.

Claims (12)

A curing agent for an epoxy resin comprising a bisimide phenol compound (a) represented by the following general formula (I) and having a solubility of 0.5% by weight or more at 60 ° C. in a ketone solvent.

(In General Formula (I), R ₁ represents a monovalent functional group other than a hydroxyl group or a hydrogen atom. R _{2 to} R ₅ each independently represents a hydrogen atom, a hydroxyl group, or an organic compound having 1 to 10 carbon atoms. Represents a group, but two adjacent groups may be bonded to each other to form a ring having a carbon number of 20 or less fused to a benzene ring, and at least one of R _{2 to} R ₅ is a hydroxyl group. Thus, the compound has two or more hydroxyl groups.
R ₆ represents an organic group having 1 to 10 carbon atoms, but two adjacent groups may be bonded to form a ring having 20 or less carbon atoms condensed with a benzene ring.
The plurality of R _{1 to} R ₆ may be the same as or different from each other.
X represents a group selected from a single bond, —SO ₂ —, —O—, —CO—, —C (CF ₃ ) ₂ —, —S—, or a divalent organic group having 1 to 20 carbon atoms. .
n is an integer of 0-3. )   The epoxy resin according to claim 1, comprising 100 parts by weight of the bisimide phenol compound (a) and 900 parts by weight or less of a curing agent for a curable resin (b) made of a compound other than the bisimide phenol compound (a). Curing agent.   The epoxy resin curing agent according to claim 1 or 2, wherein the bisimidephenol compound (a) has a solubility of 0.5 wt% or more at 60 ° C with respect to cyclohexanone.   A curable resin composition comprising an epoxy resin and the epoxy resin curing agent according to any one of claims 1 to 3.   5. The curable resin composition according to claim 4, further comprising a curing accelerator.   6. The curable resin composition according to claim 4, further comprising a thermosetting resin other than an epoxy resin and / or a filler.   The curable resin composition according to any one of claims 4 to 6, wherein the cured product has a glass transition temperature of 150 ° C or higher and a linear expansion coefficient of 65 ppm / ° C or lower at the glass transition temperature or lower. .   The curable resin composition according to any one of claims 4 to 7, which is used for a printed wiring board.   A cured resin product obtained by curing the curable resin composition according to any one of claims 4 to 8.   A laminate of the resin cured product according to claim 9 and a conductive metal.   A resin metal coating obtained by coating a metal with the resin cured product according to claim 9.   A fiber-reinforced composite material comprising the cured resin product according to claim 9 and reinforcing fibers.

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