JP2019147926A - Resin composition, resin sheet, and metal-foiled resin sheet - Google Patents

Abstract

To provide a resin composition capable of forming a cured product with high adhesion strength to metal foil.SOLUTION: The resin composition includes an epoxy compound and a curative. The curative includes a first curative comprising a compound represented by the specified formula (1), and a second curative represented by the specified formula (2).SELECTED DRAWING: None

Description

  The present invention relates to a resin composition, a resin sheet, and a resin sheet with a metal foil.

  In recent years, the number of electronic devices mounted on automobiles has been increasing. For this reason, downsizing of electronic devices is progressing rapidly. On the other hand, with the miniaturization of electronic devices, the amount of heat generated from the high-density conductors of electronic devices is increasing. For this reason, how to dissipate heat from electronic devices is an important issue.

  In Patent Document 1, an epoxy compound that can be a raw material of an epoxy resin cured product exhibiting liquid crystallinity, an epoxy composition containing the epoxy compound, an epoxy resin cured product obtained by curing the epoxy composition, and an epoxy composition as a base material A prepreg is disclosed which is semi-cured after being applied or impregnated. Since the epoxy compound described in Patent Document 1 has high heat dissipation, it is useful as an insulating material that requires high heat dissipation such as a printed wiring board.

JP 2005-206814 A

  However, the cured product of the resin composition containing a conventional epoxy compound has insufficient adhesion strength with the metal foil. In particular, in the cured product of the resin composition containing a filler in order to improve the thermal conductivity of the cured product, the adhesion strength with the metal foil was insufficient. If the adhesion strength between the metal foil and the cured product is low, for example, in the process of manufacturing an electronic device using a laminated substrate in which the metal foil is laminated on the surface of the cured product, the problem of peeling off the metal foil from the cured product occurs. It becomes easy. For this reason, there has been a demand for a resin composition that can provide a cured product having high adhesion strength to the metal foil even when a filler is contained.

This invention is made | formed in view of the said subject, and makes it a subject to provide the resin composition from which hardened | cured material with high adhesive strength with metal foil is obtained.
The present invention also includes a resin sheet made of a semi-cured product of the resin composition, a metal foil integrally formed with a resin layer containing the cured product of the resin composition, and an adhesion strength between the resin layer and the metal foil. It is an object to provide a resin sheet with a high metal foil.

In order to solve the above-mentioned problems, the present inventor has focused on the “minimum melt viscosity” and “the size of the low melt viscosity region” of the resin composition containing an epoxy compound, and have made extensive studies.
The resin composition is cured when the minimum melt viscosity of the resin composition is low and the low melt viscosity range, which is a temperature range ΔT in which the melted resin composition is less than or equal to 250 Pa · s higher than the minimum melt viscosity, is wide. The fluidity during the process is improved. For this reason, for example, when molding a cured product of a resin composition containing an epoxy compound in contact with a metal foil, the molten resin component is likely to enter the irregularities on the surface of the metal foil, and the adhesion strength with the metal foil is high. It is presumed that things will be obtained.

  The present inventors have found that a resin composition having a low minimum melt viscosity and a wide low melt viscosity region can be obtained by using two specific types of compounds as a curing agent for a resin composition containing an epoxy compound, The present invention has been conceived. That is, the present invention relates to the following inventions.

(1) including an epoxy compound and a curing agent,
A first curing agent comprising the compound represented by the following formula (1),
The resin composition characterized by including the 2nd hardening | curing agent represented by following formula (2).

（式（１）中、Ｘ_１〜Ｘ_４は、それぞれ独立に、水酸基とアミノ基のうち一方または両方を有しない置換基、または水素原子である。Ｘ_１〜Ｘ_４のうちの少なくとも１つは前記置換基である。分子中に含まれる前記置換基を構成する原子の原子量を合計した式量が７７以上である。）

(In formula (1), X _{1 to} X ₄ are each independently a substituent having one or both of a hydroxyl group and an amino group, or a hydrogen atom. At least one of X _{1 to} X ₄ Is the above substituent, and the total formula weight of atoms constituting the substituent contained in the molecule is 77 or more.)

（式（２）中、Ｒ_１〜Ｒ_１５は、それぞれ独立に水素原子または水酸基である。Ｒ_１〜Ｒ_５のうちの少なくとも１つは水酸基であり、Ｒ_６〜Ｒ_１０のうちの少なくとも１つは水酸基であり、Ｒ_１１〜Ｒ_１５のうちの少なくとも１つは水酸基である。）

(In formula (2), R _{1 to} R ₁₅ are each independently a hydrogen atom or a hydroxyl group. At least one of R _{1 to} R ₅ is a hydroxyl group, and at least one of R _{6 to} R _10. One is a hydroxyl group, and at least one of R _{11 to} R ₁₅ is a hydroxyl group.)

(2) The resin composition according to (1), comprising a filler.
(3) The mass ratio (second curing agent / first curing agent) between the first curing agent and the second curing agent is 1 to 5, described in (1) or (2) Resin composition.
(4) The substituent which does not have one or both of the hydroxyl group and the amino group in the formula (1) is a group bonded to the carbon of the benzene ring in the formula (1) via a phosphorus atom. The resin composition according to any one of (1) to (3).

(5) The compound represented by the formula (1) is a compound represented by the formula (1-1) or a compound represented by the formula (1-2) (1) to (4) The resin composition in any one of.

(6) A resin sheet comprising a semi-cured product of the resin composition according to any one of (1) to (5).
(7) a resin layer containing a cured product of the resin composition according to any one of (1) to (5);
A resin sheet with a metal foil, comprising the resin layer and a metal foil integrally molded.

  The resin composition of the present invention includes an epoxy compound and a curing agent, a first curing agent composed of a compound represented by the formula (1) as a curing agent, and a second curing agent represented by the formula (2) Therefore, the minimum melt viscosity is low and the low melt viscosity region is wide. From this, the resin composition of the present invention provides a cured product having high adhesion strength to the metal foil.

The resin sheet of the present invention comprises a semi-cured product of the resin composition of the present invention. For this reason, for example, by laminating a metal foil on the resin sheet of the present invention and heating and pressing, a resin sheet with a metal foil containing a cured product of the resin composition and having a resin layer with high adhesion strength to the metal foil can get.
The resin sheet with metal foil of the present invention has a metal foil integrally molded with the resin layer, and the resin layer contains a cured product of the resin composition of the present invention. For this reason, the resin sheet with metal foil of the present invention has high adhesion strength between the resin layer and the metal foil.

It is the perspective view which showed an example of the prepreg containing the resin sheet of this embodiment. It is the II sectional view taken on the line of FIG. It is sectional drawing which showed an example of the resin sheet with a metal foil of this embodiment.

As a result of intensive studies, the present inventor has obtained the following knowledge.
That is, the compound represented by the above formula (1) has a hydroquinone skeleton, and two hydroxyl groups (—OH) bonded to a benzene ring function as a curing agent for a resin composition containing an epoxy compound. However, the function of the compound represented by formula (1) as a curing agent is insufficient. For this reason, when only the compound represented by Formula (1) is used as a curing agent, the resin composition may not be cured. Therefore, the compound represented by Formula (1) has not been conventionally used as a curing agent.

  On the other hand, the compound represented by the above formula (2) has three or more hydroxyl groups (—OH) and has a sufficient function as a curing agent for a resin composition containing an epoxy compound. However, when only the compound represented by the above formula (2) is used as a curing agent, the resin composition containing an epoxy compound is cured because the resin composition has a high minimum melt viscosity and a low low melt viscosity region. The fluidity at the time was insufficient. For this reason, the hardened | cured material with sufficiently high adhesive strength with metal foil was not obtained.

  This inventor repeated earnest examination and uses the compound represented by Formula (2) with the compound represented by Formula (1) as a hardening | curing agent of the resin composition containing an epoxy compound. It has been found that a resin composition having a low low melt viscosity range can be obtained. This is presumed to be an effect due to the steric hindrance of the compound represented by the formula (1) and the reaction between the epoxy compound and the compound represented by the formula (2) being suppressed.

  When the minimum melt viscosity of the resin composition is low and the low melt viscosity region is wide, the fluidity when the resin composition is cured is good. For this reason, for example, when molding the cured product of the resin composition in contact with the metal foil, the melted resin component easily enters the irregularities on the surface of the metal foil, and a cured product having high adhesion strength with the metal foil is obtained. It is estimated to be.

Moreover, when the filler is contained in the molten resin composition, the fluidity | liquidity of the filler in a resin composition also becomes favorable. As a result, the filler is blocked by the unevenness on the surface of the metal foil and easily aggregates, and a heat conduction path made of the aggregated filler is easily formed. Thereby, there is a possibility that the effect of improving the thermal conductivity due to the inclusion of the filler can be further improved.
Moreover, since the resin component (epoxy compound and curing agent) in the molten resin composition is more likely to enter the irregularities on the surface of the metal foil than the filler, the contact area between the metal foil and the resin component is sufficient even if the filler is included. Secured. As a result, it is presumed that a cured product having high adhesion strength with the metal foil can be obtained even when a cured product of the resin composition containing the filler is formed in contact with the metal foil.

  Hereinafter, the resin composition of the present invention, a prepreg including a resin sheet, and a resin sheet with a metal foil will be described in detail with reference to the drawings. In the drawings used in the following description, in order to make the characteristics of the present invention easier to understand, there are cases where the characteristic parts are enlarged for convenience. Therefore, the dimensional ratios of the components described in the drawings may be different from actual ones. The materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not limited thereto, and can be implemented with appropriate modifications within a range that does not change the gist thereof.

[Resin composition]
The resin composition of this embodiment contains an epoxy compound and a curing agent.
(Epoxy compound)
The epoxy compound contained in the resin composition of the present embodiment is polymerized by a curing agent to form a semi-cured product and a resin cured product (hereinafter sometimes abbreviated as “cured product”) together with the curing agent. Examples of the epoxy compound include bisphenol A type, bisphenol F type, glycidyl ether type, glycidyl ester type, and glycidyl amine type. As the epoxy compound, one of them may be used alone, or a plurality of them may be used in combination.
The average epoxy equivalent of the epoxy compound may be, for example, 100 to 1000 g / eq.

  It is preferable to use an epoxy compound having a mesogen skeleton. The mesogenic skeleton is a general term for an atomic group including two or more aromatic rings and having rigidity and orientation. Two or more aromatic rings contained in the mesogenic skeleton are connected by a single bond and / or a non-single bond. That is, the bond of two or more aromatic rings contained in the mesogen skeleton may be only a single bond, only a non-single bond, or both a single bond and a non-single bond. When three or more aromatic rings are included in the mesogenic skeleton, and the three or more aromatic rings are connected by two or more non-single bonds, the types of the two or more non-single bonds are the same in part or all. There may be all or different.

The non-single bond is a generic name for divalent groups containing one or more constituent elements and one or more multiple bonds. Non-single bonds include, for example, one or more constituent elements of carbon (C), nitrogen (N), oxygen (O), and hydrogen (H). Further, the non-single bond includes one or both of a double bond and a triple bond as a multiple bond.
Specifically, the non-single bond includes a bond represented by any one of the following formulas (3-1) to (3-10). In addition, the arrow shown to each of following formula (3-6) and formula (3-10) represents the coordinate bond.

When three or more aromatic rings are included in the mesogen skeleton, the direction of bonding of the three or more aromatic rings is not particularly limited. For example, three or more aromatic rings may be bonded linearly or may be bonded so as to be bent once or more along the way.
Examples of the mesogen skeleton in which two or more aromatic rings are bonded by a single bond include a biphenyl skeleton and a terphenyl skeleton. The terphenyl skeleton may be an o-terphenyl skeleton, an m-terphenyl skeleton, or a p-terphenyl skeleton.

  By using an epoxy compound having a mesogen skeleton as the epoxy compound, it is possible to improve the stacking property of the benzene ring together with the aromatic compound contained in the curing agent. As a result, in the cured product of the resin composition, phonon scattering, which causes a decrease in thermal conductivity, can be suppressed. Therefore, by using an epoxy compound having a mesogenic skeleton as the epoxy compound, a resin composition is obtained in which a cured product having high thermal conductivity and good heat dissipation is obtained.

As the epoxy compound having a mesogen skeleton, glycidyl ethers having a biphenyl skeleton and two or more epoxy groups in one molecule can be used. Examples of glycidyl ethers include biphenyl glycidyl ether and tetramethylbiphenyl glycidyl ether.
As the epoxy compound having a mesogen skeleton, glycidyl ethers having a terphenyl skeleton in one molecule may be used.

  As the epoxy compound, a phosphorus-containing epoxy compound containing a phosphorus atom may be used. By using a phosphorus containing epoxy compound as an epoxy compound, it becomes the resin composition from which hardened | cured material with favorable flame retardance is obtained.

(Curing agent)
The hardening agent contained in the resin composition of this embodiment contains the 1st hardening agent which consists of a compound represented by following formula (1), and the 2nd hardening agent represented by following formula (2).

（式（１）中、Ｘ_１〜Ｘ_４は、それぞれ独立に、水酸基とアミノ基のうち一方または両方を有しない置換基、または水素原子である。Ｘ_１〜Ｘ_４のうちの少なくとも１つは前記置換基である。分子中に含まれる前記置換基を構成する原子の原子量を合計した式量が７７以上である。）

(In formula (1), X _{1 to} X ₄ are each independently a substituent having one or both of a hydroxyl group and an amino group, or a hydrogen atom. At least one of X _{1 to} X ₄ Is the above substituent, and the total formula weight of atoms constituting the substituent contained in the molecule is 77 or more.)

（式（２）中、Ｒ_１〜Ｒ_１５は、それぞれ独立に水素原子または水酸基である。Ｒ_１〜Ｒ_５のうちの少なくとも１つは水酸基であり、Ｒ_６〜Ｒ_１０のうちの少なくとも１つは水酸基であり、Ｒ_１１〜Ｒ_１５のうちの少なくとも１つは水酸基である。）

(In formula (2), R _{1 to} R ₁₅ are each independently a hydrogen atom or a hydroxyl group. At least one of R _{1 to} R ₅ is a hydroxyl group, and at least one of R _{6 to} R _10. One is a hydroxyl group, and at least one of R _{11 to} R ₁₅ is a hydroxyl group.)

"First curing agent"
In the compound represented by the formula (1) which is the first curing agent, X _{1 to} X ₄ are each independently a substituent that does not have one or both of a hydroxyl group (—OH) and an amino group (—NH ₂ ). A group, or a hydrogen atom (-H). At least one of X _{1 to} X ₄ is a substituent that does not have one or both of a hydroxyl group and an amino group.

The hydroxyl group and amino group have a function of accelerating the curing of the resin composition containing the epoxy compound. When X _{1 to} X ₄ in the compound represented by the formula (1) include a substituent having one or both of a hydroxyl group and an amino group, the minimum melt viscosity of the resin composition is increased, and The melt viscosity region is narrowed. Therefore, the function of suppressing the curing reaction of the resin composition by the first curing agent cannot be obtained. Therefore, the X ₁ to X ₄ in the compound represented by formula (1), substituent groups having one or both of hydroxyl group and amino group are not included.

When two or more of X _{1 to} X ₄ are substituents having no one or both of a hydroxyl group and an amino group, the hydroxyl group and amino group contained in the molecule of the compound represented by formula (1) Of these, the substituents that do not have one or both may all be the same, may be different from each other, or may be the same as only part of them.
In the compound represented by the formula (1), X ₁ and X ₂ may form a new ring structure together with a part of the benzene ring in the formula (1). X ₃ and X ₄ may form a new ring structure together with a part of the benzene ring in formula (1).

  In the compound represented by the formula (1), the total formula weight of the atoms constituting the substituent having no one or both of the hydroxyl group and amino group contained in one molecule is 77 or more. Since the formula weight of the substituent which does not have one or both of the hydroxyl group and the amino group is 77 or more, the compound represented by the formula (1) as the first curing agent becomes steric hindrance, and the epoxy compound and the second curing The reaction with the agent is suppressed, and the resin composition has a low minimum melt viscosity and a wide low melt viscosity region. When the formula weight of the substituent which does not have one or both of a hydroxyl group and an amino group is less than 77, the function as a steric hindrance in the reaction between the epoxy compound and the second curing agent becomes insufficient, and the epoxy compound and the second The effect of suppressing the reaction with the curing agent cannot be sufficiently obtained.

The substituent which does not have one or both of the hydroxyl group and amino group in formula (1) is preferably a group containing a phosphorus atom. When the substituent which does not have one or both of a hydroxyl group and an amino group is a group containing a phosphorus atom, it becomes a resin composition from which a cured product having good flame retardancy can be obtained.
When the substituent that does not have one or both of the hydroxyl group and amino group in formula (1) is a group containing a phosphorus atom, the substituent that does not have one or both of hydroxyl group and amino group is represented by formula (1) It is preferably a group bonded to carbon of the benzene ring through a phosphorus atom. Moreover, when the substituent which does not have one or both of a hydroxyl group and an amino group is a group containing a phosphorus atom, the substituent which does not have one or both of a hydroxyl group and an amino group contains a phosphorus atom and a benzene ring. It is preferably a group.

  Specific examples of the compound represented by the formula (1) include compounds represented by the following formulas (1-1) to (1-5). Among these compounds, the formulas (1-1), (1-2), (1-4), and (1-5) in which the substituent that does not have one or both of a hydroxyl group and an amino group include a phosphorus atom are In particular, in particular the compound of formula (1-1) (10- (2,5-dihydroxyphenyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) and / or A compound having a triphenylphosphine skeleton such as a compound represented by the formula (1-2) (2- (diphenylphosphinyl) hydroquinone) is preferable. The compound represented by the formula (1-1) and the compound represented by the formula (1-2) effectively function as steric hindrance in the reaction between the epoxy compound and the second curing agent. For this reason, reaction with an epoxy compound and a 2nd hardening | curing agent is suppressed notably, the minimum melt viscosity is lower, and it becomes a resin composition with a wider low melt viscosity area | region.

"Second curing agent"
In the compound represented by the formula (2) which is the second curing agent, R _{1 to} R ₁₅ are each independently a hydrogen atom (—H) or a hydroxyl group (—OH). At least one of R _{1 to} R ₅ is a hydroxyl group, at least one of R _{6 to} R ₁₀ is a hydroxyl group, and at least one of R _{11 to} R ₁₅ is a hydroxyl group.
In the compound represented by the formula (2), the benzene rings easily overlap each other by π-π stacking, and the interval between the benzene rings can be reduced. For this reason, the hardened | cured material of the resin composition containing the compound represented by Formula (2) has a high density and a high thermal conductivity. In addition, the cured product of the resin composition containing the compound represented by the formula (2) has high thermal conductivity because scattering of molecular lattice vibrations is suppressed by the compound represented by the formula (2). It is estimated that

In the compound represented by the formula (2), it is preferable that only one of R _{1 to} R ₅ is a hydroxyl group. Moreover, it is preferable that only one of R _{6 to} R ₁₀ is a hydroxyl group. It is preferable that only one of R _{11 to} R ₁₅ is a hydroxyl group.
In particular, in the compound represented by the formula (2), only one of R _{1 to} R ₅ , only one of R _{6 to} R ₁₀ , and only one of R _{11 to} R ₁₅ A hydroxyl group is preferred. This compound is a compound having three hydroxyl groups in one molecule, and each of the active hydrogens of the three hydroxyl groups can react with the epoxy group of the epoxy compound. Therefore, the cured product of the resin composition containing this compound has a high heat dissipation property having a strong cross-link density and a strong resin structure.

In the compound represented by the formula (2), only one of R _{1 to} R ₅ , only one of R _{6 to} R ₁₀ , and only one of R _{11 to} R ₁₅ are hydroxyl groups. Examples of the compound include 1,3,5-tris (4-hydroxyphenyl) benzene represented by the following formula (2-1) or 1,3,5-tris (3-hydroxy) represented by the following formula (2-2). Phenyl) benzene.

It is preferable that the ratio of the 1st hardening | curing agent which consists of a compound represented by Formula (1) contained in a hardening | curing agent and the 2nd hardening | curing agent represented by Formula (2) is the range shown below.
The mass ratio (second curing agent / first curing agent) between the first curing agent and the second curing agent in the curing agent is preferably 1 to 5, and more preferably 1 to 3. When the above mass ratio is 1 or more, the resin composition sufficiently includes the second curing agent. As a result, a cured product having high thermal conductivity is obtained by the reaction between the epoxy compound and the second curing agent, which is preferable. Moreover, hardened | cured material with higher adhesive strength with metal foil is obtained as said mass ratio is 1 or more. When the mass ratio is 5 or less, the resin composition sufficiently includes the first curing agent. As a result, the reaction between the epoxy compound and the second curing agent is more effectively suppressed, resulting in a resin composition having a lower minimum melt viscosity and a wider low melt viscosity region. Furthermore, in order to obtain a resin composition having a low minimum melt viscosity and a wide low melt viscosity region, the mass ratio is more preferably 3 or less.

  The ratio of the epoxy compound and the curing agent contained in the resin composition can be appropriately determined according to the type of the epoxy compound. Regarding the ratio of the epoxy compound and the curing agent, for example, the hydroxyl equivalent of the curing agent is preferably 50 to 250 and the hydroxyl equivalent of the curing agent is 80 to 150 with respect to 100 epoxy equivalent of the epoxy compound. More preferred. By setting the ratio of the curing agent to the epoxy compound within the above range, it becomes a resin composition from which a cured product having a sufficiently high crosslinking density can be obtained, which is preferable.

(Filler)
The resin composition of this embodiment may contain a filler in addition to the epoxy compound and the curing agent. By using a resin composition containing a filler, a cured product having higher thermal conductivity can be obtained.
Examples of the filler include boron nitride particles, magnesium oxide particles, alumina particles, aluminum hydroxide particles, aluminum nitride particles, and silica particles. As the filler, one of these may be used alone, or a plurality of types may be used in combination.

  The filler content (volume (volume%) of filler per unit volume) contained in the resin composition is preferably 49 to 58% by volume, and more preferably 53 to 55% by volume. It is preferable that the filling amount of the filler is 49% by volume or more because a cured product having higher thermal conductivity can be obtained. When the filling amount of the filler is 58% by volume or less, for example, when forming a cured product of the resin composition in contact with the metal foil, the fluidity of the resin composition is hardly impaired by the filler, and the adhesion with the metal foil A cured product with high strength is easily obtained.

  As the filler, it is preferable to use a filler having a volume-based average particle diameter of 1 to 100 μm, more preferably 3 to 70 μm, as measured by a commercially available laser diffraction particle size distribution analyzer. The particle size distribution of the filler measured by the measuring device may have a plurality of peaks.

The resin composition of this embodiment may contain arbitrary components as needed in addition to the epoxy compound, the curing agent, and the filler. Examples of optional components include a curing accelerator (curing catalyst), a coupling agent, a flame retardant, a solvent (diluent), a plasticizer, and a lubricant.
Examples of the curing accelerator (curing catalyst) include phosphines and imidazoles (such as 2-ethyl-4-methylimidazole).
Examples of coupling agents include silane coupling agents and titanate coupling agents.
Examples of the flame retardant include halogen.
Examples of the solvent (diluent) include ketone solvents such as methyl ethyl ketone and acetone, and cyclic ether solvents such as 1,3-dioxolane.

Since the resin composition of the present embodiment includes the first curing agent and the second curing agent, the minimum melt viscosity is low and the low melt viscosity region is wide.
The minimum melt viscosity of the resin composition is preferably 170 to 1500 Pa · s, and preferably 170 to 1300 Pa · s so that good fluidity can be obtained.
Further, the low melt viscosity region in the present embodiment is a temperature range ΔT in which the melted resin composition has a viscosity of 250 Pa · s higher than the minimum melt viscosity. It is preferable that the low melt viscosity area | region in a resin composition is 15-62 degreeC so that favorable fluidity | liquidity may be obtained.
When the minimum melt viscosity is 1500 Pa · s or less and the low melt viscosity region is 15 ° C. or more, the fluidity when the resin composition is cured is further improved.

  The resin composition of this embodiment can be manufactured by the method of mixing an epoxy compound, a hardening | curing agent, the filler contained as needed, and an arbitrary component, for example.

The resin composition of this embodiment includes an epoxy compound and a curing agent, and includes a first curing agent composed of a compound represented by formula (1) as a curing agent, and a second curing agent represented by formula (2). Including. For this reason, the resin composition of this embodiment has a low minimum melt viscosity, a low low melt viscosity region, and a cured product having a high adhesion strength with the metal foil.
Moreover, when the resin composition of this embodiment contains a filler, hardened | cured material with high heat conductivity and high adhesive strength with metal foil is obtained.

[Prepreg]
FIG. 1 is a perspective view showing an example of a prepreg including the resin sheet of the present embodiment. 2 is a cross-sectional view taken along the line II of FIG. FIG. 2 shows a cross section when the prepreg shown in FIG. 1 is cut along the thickness direction.

The prepreg 12 shown in FIG. 2 includes a fibrous core material 30 and a resin component 22 in a semi-cured state (B stage state) impregnated in the core material 30. The resin component 22 of the prepreg 12 of this embodiment is a resin sheet made of a semi-cured product of the resin composition of the above-described embodiment.
Examples of the core material 30 include woven fabric and non-woven fabric. Examples of the material for the woven fabric and the non-woven fabric include one type or two or more types of fibers selected from glass fibers, carbon fibers, metal fibers, natural fibers, polyester fibers, polyamide fibers, and other synthetic fibers. However, the core material 30 is not limited to these.

The prepreg 12 shown in FIG. 2 can be manufactured by the method shown below, for example.
After impregnating the core material 30 with a technique such as coating or dipping, the core material 30 impregnated with the resin composition is heated. By this heating, the resin composition is semi-cured to obtain the prepreg 12 including the resin component 22.
The heating conditions for semi-curing the resin composition can be, for example, 60 to 150 ° C. for about 1 to 120 minutes, and 70 to 120 ° C. for about 3 to 90 minutes.

  In the prepreg 12 of the present embodiment, the semi-cured resin component 22 impregnated in the core material 30 is a semi-cured product of the resin composition of the above-described embodiment. For this reason, for example, by laminating a metal foil on the prepreg 12 and heating and pressing, a resin sheet with a metal foil containing a cured product of the resin composition and having a resin layer with high adhesion strength to the metal foil is obtained.

[Resin sheet with metal foil]
FIG. 3 is a cross-sectional view showing an example of the resin sheet with metal foil of the present embodiment. A resin sheet 41 with a metal foil shown in FIG. 3 includes a resin layer 20 containing a cured product of the resin composition of the embodiment described above, a fibrous core member 30 disposed in the resin layer 20, and a resin layer 20. And a metal foil 40 disposed in contact therewith. The metal foil 40 is integrally formed with the resin layer 20.
As the metal foil 40, a known one can be appropriately selected and used. Specifically, as the metal foil 40, for example, a copper foil, a nickel foil, an aluminum foil, or the like can be used. The thickness of a metal layer is not specifically limited, For example, it is about 3-150 micrometers. The metal foil 40 may be etched and / or punched.
As the core material 30, the same material as the core material 30 that can be used for the prepreg 12 shown in FIG. 2 can be used.

The resin sheet 41 with metal foil shown in FIG. 3 can be manufactured by the method shown below, for example.
A metal foil 40 is laminated on the surface of the prepreg 12 shown in FIG. By this heating, the resin component 22 that is a semi-cured product of the resin composition melts and flows, and enters the irregularities on the surface of the metal foil 40. Thereafter, the resin component 22 is cured to become the resin layer 20, and the resin layer 20 with the metal foil in which the resin layer 20 and the metal foil 40 that have entered the irregularities on the surface of the metal foil 40 are integrated. Subsequently, etching and / or punching may be performed on the metal foil 40 integrated with the resin layer 20.
The heating conditions for curing the resin component 22 that is a semi-cured product are, for example, about 100 to 250 ° C. and about 1 to 300 minutes.
When heating the prepreg 12 having the metal foil 40 laminated on the surface, it may be pressurized. The pressurizing condition can be, for example, about 0.1 to 10 MPa.

  The resin sheet 41 with metal foil of this embodiment has the metal foil 40 integrally molded with the resin layer 20, and the resin layer 20 contains the hardened | cured material of the resin composition of embodiment mentioned above. For this reason, the resin sheet 41 with metal foil of this embodiment has a high adhesion strength between the resin layer 20 and the metal foil 40.

As mentioned above, although several embodiment of this invention was described, this invention is not limited to the said embodiment at all.
For example, in the above-described embodiment, as the resin sheet 41 with the metal foil, the resin layer 20, the core material 30, and the metal foil 40 integrally molded with the resin layer 20 have been described as examples. The resin sheet with a metal foil may have a resin layer and a metal foil integrally molded with the resin layer, and may not have a core material.

  Such a resin sheet with a metal foil can be manufactured by the method shown below, for example. The resin composition is applied onto a release film made of polyethylene terephthalate (PET) or the like to form a coating film, and the resin composition is semi-cured by heating to form a resin comprising a sheet-like semi-cured product Manufacture sheets. The heating conditions for semi-curing the resin composition are the same as in the above-described embodiment. And metal foil is laminated | stacked on the surface of the resin sheet which consists of a obtained sheet-like semi-hardened material, and it heats. By this heating, a resin sheet made of a semi-cured product of the resin composition is cured to form a resin layer, and a resin sheet with a metal foil in which the resin layer and the metal foil are integrated. When heating a sheet-like semi-cured product having a metal foil laminated on the surface, pressure may be applied. The heating and pressurizing conditions are the same as in the above-described embodiment.

In the above-described embodiment, the resin sheet with metal foil 41 has been described by taking as an example the one produced by laminating the metal foil 40 on the surface of one prepreg 12, but the resin sheet with metal foil is The metal foil 40 may be laminated and heated on the surface of the plurality of prepregs 12. Such a resin sheet with a metal foil is suitable as a laminated substrate.
Further, the metal foil 40 may be disposed on both sides as well as one surface of a single prepreg or a laminate in which a plurality of prepregs are laminated.
Moreover, the resin sheet with metal foil may have a circuit.

  Hereinafter, the contents of the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

(Examples 1-20, Comparative Examples 1-5)
An epoxy compound, a first curing agent, a second curing agent, a filler, a curing catalyst, and methyl ethyl ketone, which is a solvent, are mixed, and a non-volatile component (an epoxy compound, a first curing agent, and a second curing agent) Resin compositions of Examples 1 to 34 and Comparative Examples 1 to 5 were 90% by mass.
The epoxy compound, the first curing agent, the second curing agent, and the filler are used in the ratios (mass ratios) shown in Tables 1 to 5, and the epoxy equivalent of the epoxy compound is the hydroxyl equivalent of the first curing agent and the second curing agent. It was made to become the same as the sum total of the hydroxyl equivalents (hydroxyl equivalent: epoxy equivalent = 1: 1).
The curing catalyst was contained in an amount of 1 part by mass with respect to a total of 100 parts by mass of the epoxy compound, the first curing agent, and the second curing agent.

  “Formula weight of substituent” in Table 1 to Table 5 means that one or both of a hydroxyl group and an amino group contained in one molecule when the following curing agents a to f are applied to the formula (1). The formula weight is the sum of the atomic weights of the atoms constituting the non-substituent.

(Epoxy compound)
Epoxy compound A: mesogenic skeleton, average epoxy equivalent = 175 g / eq, about 1: 1 mixture of tetramethylbiphenol type epoxy resin and 4,4′-biphenol type epoxy resin. (Product name: YL-6121H, manufactured by Mitsubishi Chemical Corporation)
Epoxy compound B: a bisphenol A type liquid epoxy resin having no mesogen skeleton, average epoxy equivalent = 184 g / eq. (Product name: 840-S, manufactured by DIC Corporation)
Epoxy compound C: no mesogen skeleton, average epoxy equivalent = 118 g / eq, tetrafunctional polyglycidylamine. (Product name: YH434L, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)

(First curing agent)
Curing agent a: Compound represented by the following formula (1-3) Curing agent b: Compound represented by the following formula (1-4) Curing agent c: Compound represented by the following formula (1-5) Curing agent d: Following Compound represented by formula (1-1) Curing agent e: Compound represented by the following formula (1-2) Curing agent f: Compound represented by the following formula (1-6)

(Second curing agent)
Curing agent g: Compound represented by the following formula (2-1) Curing agent h: Compound represented by the following formula (2-2)

(Filler)
Magnesium oxide particles (manufactured by Ube Materials Co., Ltd., average particle size: 50 μm)
(Curing catalyst)
2-Ethyl-4-methylimidazole (manufactured by Shikoku Kasei Co., Ltd., trade name: imidazole compound 2E4MZ)

  The resin compositions of Examples 1 to 34 and Comparative Examples 1 to 5 thus obtained were examined for “minimum melt viscosity”, “low melt viscosity region” and “adhesion strength to copper foil” by the following method. It was. The results are shown in Tables 1-5.

"Minimum melt viscosity""Low melt viscosity range"
The resin composition is applied onto a release film to form a coating film, and the resin composition is semi-cured by heating it at 90 ° C. for 30 minutes, so that the sheet is semi-cured with a thickness of 1.8 mm. I got a thing. Next, a disk-shaped test piece having a diameter of 20 mm was cut out from the sheet-like semi-cured product.
Using a viscoelasticity measuring device (Rheo Stress 6000 manufactured by Thermo Scientific Co., Ltd.), the test piece was heated at a starting temperature of 100 ° C. and a heating rate of 2.5 ° C./min. Measurements were made.

  When the melt viscosity is measured under the above measurement conditions, the melt viscosity of the test piece changes so as to draw a downward convex curve as the temperature of the test piece increases. That is, in the first half of the measurement of the melt viscosity, the test piece is gradually melted as the temperature rises, so that the melt viscosity decreases as the temperature rises. On the other hand, in the latter half of the measurement of the melt viscosity, the curing reaction gradually proceeds as the temperature rises, so that the melt viscosity increases as the temperature rises.

  The lowest melt viscosity when the melt viscosity of the test piece was measured under the above-described measurement conditions was determined and used as the minimum melt viscosity. In addition, when the melt viscosity of the test piece was measured under the above measurement conditions, the temperature range ΔT of the test piece that was not more than 250 Pa · s higher than the minimum melt viscosity was obtained and set as a low melt viscosity region.

"Strength of adhesion to copper foil"
The resin composition was applied and impregnated on both surfaces of a core material 30 made of glass cloth fiber woven fabric having a thickness of 0.05 mm and a fabric weight of 50 g / m ² . Thereafter, the core material 30 impregnated with the resin composition was heated at 90 ° C. for 30 minutes to semi-cure the resin composition, and the prepreg 12 shown in FIG. The fabric weight of the obtained prepreg 12 was 360 g / m ² .

Next, two prepregs 12 were laminated, and a copper foil having a thickness of 35 μm was laminated on both sides to form a laminate. Then, using a flat plate press, the laminate was pressurized at a pressure of 1 MPa for 20 minutes while being heated at a temperature of 170 ° C., and further pressurized at a pressure of 4 MPa for 60 minutes while being heated at a temperature of 200 ° C. Thereby, the resin sheet with metal foil in which the resin layer in which the resin component was cured and the copper foil disposed on both surfaces of the resin layer were integrally formed was obtained.
Using the resin sheet with metal foil thus obtained, as shown below, a peel test based on JIS C 6481 was performed, and the adhesion strength of the resin layer to the copper foil was measured.

First, a sample piece having a width of 25 mm and a length of 100 mm was cut out from a resin sheet with a metal foil. Thereafter, using a knife, a copper foil pattern having a width of 10 ± 0.1 mm and a length of 100 mm is formed in the central portion in the width direction of one surface of the sample piece, and other than the copper foil pattern from one surface of the sample piece. The copper foil was removed and used as a measurement sample.
Next, 15 mm of one end of the copper foil pattern of the measurement material was peeled off in the length direction, and the peeled portion was attached to the support metal fitting. And the support metal fitting was pulled at the speed | rate of 50 mm / min in the orthogonal | vertical direction of the surface in which the copper foil pattern is formed, and the peeling strength when peeling a copper foil pattern from a measurement material was measured. The unit of measurement is kN / m.

  Moreover, "thermal conductivity change rate" was investigated by the method shown below using the resin compositions of Examples 1 to 34 and Comparative Examples 1 to 5. The results are shown in Tables 1-5.

"The rate of change in thermal conductivity"
(Measurement of thermal conductivity of laminated cured product)
Six prepregs 12 similar to the prepreg 12 used in the above-described measuring method of “adhesion strength to copper foil” were laminated, and a copper foil having a thickness of 35 μm was laminated on both surfaces to obtain a laminate. And the laminated body was heated and pressurized like the resin sheet with metal foil manufactured with the measuring method of "adhesion strength to copper foil", and the resin sheet with metal foil was obtained. Thereafter, the copper foil was removed from both surfaces of the resin sheet with metal foil to obtain a laminated cured product having a thickness of 0.9 mm.

The obtained laminated cured product was cut to prepare a circular measurement sample having a diameter of 10 mm and a thickness of 0.9 mm. Subsequently, the thermal diffusion coefficient α [m ² / s] of the measurement sample was measured using a thermal conductivity measuring device (manufactured by Advance Riko Co., Ltd. (formerly ULVAC Riko Co., Ltd., device name: TC-7000)). .
The specific heat Cp [J / (kg · K)] of the measurement sample was measured using differential scanning line calorimetry (DSC) using sapphire as a standard sample. Furthermore, the density r [kg / m ³ ] of the measurement sample was measured using the Archimedes method. Using these measured values, the thermal conductivity λ [W / (m · K)] of the laminated cured product was calculated by the following formula.
λ = α × C _p × r
(Wherein λ is the thermal conductivity [W / (m · K)], α is the thermal diffusion coefficient [m ² / s], C _p is the specific heat [J / (kg · K)], and r is the density [kg. / M ³ ].)

Next, the ratio of the “thermal conductivity of the laminated cured product” of each example to the “thermal conductivity of the laminated cured product” of the comparative example in which the epoxy compound is the same and does not include the first curing agent, And calculated as the rate of change in thermal conductivity. The results are shown in Tables 1 to 4.
Thermal conductivity change rate (%) = (thermal conductivity of laminated cured product of example including first curing agent / thermal conductivity of laminated cured product of comparative example having same epoxy compound and no first curing agent Rate) x 100
Further, the ratio of the “thermal conductivity of the laminated cured product” of Comparative Examples 4 and 5 to the “thermal conductivity of the laminated cured product” of the comparative example in which the epoxy compound is the same and does not include the first curing agent, Calculation was performed in the same manner as the rate of change in thermal conductivity of the example, and the rate of change in thermal conductivity was used. The results are shown in Table 5.

  As shown in Tables 1 to 5, Examples 1 to 34 including the epoxy compound, the first curing agent, and the second curing agent include Comparative Example 1 that includes the epoxy compound and the second curing agent and does not include the first curing agent. Compared with ˜3, the “minimum melt viscosity” was low, the “low melt viscosity region ΔT” was wide, and the “adhesion strength to the copper foil” was high. In Examples 1 to 34, the “thermal conductivity change rate” was sufficiently large, and the thermal conductivity was equivalent to that of Comparative Examples 1 to 3. From this, according to the resin composition of Examples 1-34, the hardened | cured material which has high adhesive strength with metal foil is obtained, maintaining the heat conductivity equivalent to the resin composition of Comparative Examples 1-3. It was confirmed that

From the results of Examples 1 to 26, in order to obtain a resin composition having a low “minimum melt viscosity” and a wide “low melt viscosity region ΔT”, the formula (1-1) is used as the first curing agent. It was confirmed that it was preferable to use the compound (see Examples 15 to 18, 25 and 26) or the compound represented by formula (1-2) (see Examples 19 to 22).
Further, from the results of Examples 1 to 26 and Comparative Examples 4 and 5, the compound represented by the formula (1-6) having a “substituent formula weight” of less than 77 has a function of lowering the “minimum melt viscosity”. It was also found that the function of widening the “low melt viscosity region ΔT” is insufficient.

  DESCRIPTION OF SYMBOLS 12 ... Prepreg, 20 ... Resin layer, 22 ... Resin component, 30 ... Core material, 40 ... Metal foil, 41 ... Resin sheet with metal foil

Claims (7)

An epoxy compound and a curing agent,
A first curing agent comprising the compound represented by the following formula (1),
The resin composition characterized by including the 2nd hardening | curing agent represented by following formula (2).

(In formula (1), X _{1 to} X ₄ are each independently a substituent having one or both of a hydroxyl group and an amino group, or a hydrogen atom. At least one of X _{1 to} X ₄ Is the above substituent, and the total formula weight of atoms constituting the substituent contained in the molecule is 77 or more.)

(In formula (2), R _{1 to} R ₁₅ are each independently a hydrogen atom or a hydroxyl group. At least one of R _{1 to} R ₅ is a hydroxyl group, and at least one of R _{6 to} R _10. One is a hydroxyl group, and at least one of R _{11 to} R ₁₅ is a hydroxyl group.)   The resin composition according to claim 1, comprising a filler.   The resin composition according to claim 1 or 2, wherein a mass ratio (second curing agent / first curing agent) between the first curing agent and the second curing agent is 1 to 5. .   The substituent which does not have one or both of the hydroxyl group and the amino group in the formula (1) is a group bonded to the carbon of the benzene ring in the formula (1) via a phosphorus atom. The resin composition according to any one of claims 1 to 3. The compound represented by the formula (1) is a compound represented by the formula (1-1) or a compound represented by the formula (1-2). The resin composition according to one item.

  A resin sheet comprising a semi-cured product of the resin composition according to any one of claims 1 to 5. A resin layer containing a cured product of the resin composition according to any one of claims 1 to 5,
A resin sheet with a metal foil, comprising the resin layer and a metal foil integrally molded.

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