JP2020193270A - Thermosetting resin composition, prepreg, metal foil with resin, laminate, printed wiring board and semiconductor package - Google Patents

Abstract

To provide a thermosetting resin composition that has sufficient heat resistance and low elastic modulus, and has high adhesive strength to a metal foil at room temperature and high temperature, a prepreg including the thermosetting resin composition, a metal foil with a resin, a laminate, a printed wiring board and a semiconductor package.SOLUTION: A thermosetting resin composition contains (A) a phenolic resin, (B) a thermosetting resin, (C) an acrylic polymer, and (D) a copolymer resin containing a structural unit derived from an aromatic vinyl compound and a structural unit derived from a maleic anhydride, the (A) component containing (A1) a phenolic resin having a C10-25 chain aliphatic hydrocarbon group.SELECTED DRAWING: None

Description

The present invention relates to thermosetting resin compositions, prepregs, metal foils with resins, laminates, printed wiring boards and semiconductor packages.

The wiring board material used for the high-performance printed wiring board is required to have heat resistance, electrical insulation, long-term reliability, component connection reliability, and the like.
Further, in a substrate on which a ceramic component is mounted, a difference in the coefficient of thermal expansion between the ceramic component and the substrate and a decrease in component connection reliability caused by an external impact are major problems. As a solution to this problem, stress relaxation from the base material side has also been proposed. In order to solve these problems, a resin composition containing a thermosetting resin and a thermoplastic resin such as an acrylic polymer and a terminal-modified polyether sulfone has been proposed (for example, Patent Documents 1 to 3). reference).

Japanese Unexamined Patent Publication No. 8-283535 JP-A-2002-134907 JP-A-2002-371190

However, in recent years, the printed wiring board is often applied in a harsh environment such as a high temperature environment, and according to the study by the present inventors, the conventional printed wiring board is a metal foil in a harsh environment. It became clear that it was difficult to secure the adhesive strength of.

The present invention has been made in view of the above circumstances, and is a thermosetting resin composition having sufficient heat resistance and low elastic coefficient, and having high adhesive strength with a metal foil in a normal temperature environment and a high temperature environment. An object of the present invention is to provide a prepreg, a metal foil with a resin, a laminate, a printed wiring board, and a semiconductor package using the thermosetting resin composition.

As a result of diligent research to solve the above problems, the present inventors have found that the above problems can be solved by the following invention, and have completed the present invention.

That is, the present invention relates to the following [1] to [21].
[1] (A) Phenolic resin,
(B) Thermosetting resin,
A copolymer resin having (C) an acrylic polymer and (D) a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride.
Is a thermosetting resin composition containing
A thermosetting resin composition, wherein the component (A) contains (A1) a phenolic resin having a chain aliphatic hydrocarbon group having 10 to 25 carbon atoms.
[2] The component (A1) comprises a structural unit derived from a phenolic compound represented by the following general formula (1) and a structural unit derived from a phenolic compound represented by the following general formula (2). The thermosetting resin composition according to the above [1].

(In the formula, R ¹ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms which may have a substituent, and an aromatic having 5 to 15 ring-forming atoms which may have a substituent. A group hydrocarbon group or a combination of the aliphatic hydrocarbon group and the aromatic hydrocarbon group is shown. R ² represents a chain aliphatic hydrocarbon group having 10 to 25 carbon atoms, and X is hydrogen. Indicates an atom, hydroxy group or hydroxymethyl group.)
[3] The above-mentioned [1] or [2], wherein the content of the component (A1) is 0.1 to 40 parts by mass with respect to 100 parts by mass of the total amount of the resin component of the thermosetting resin composition. Thermosetting resin composition.
[4] The component (B) is an epoxy resin, a cyanate resin, a bismaleimide-based compound, an addition polymer of a bismaleimide-based compound and a diamine compound, an isocyanate resin, a triallyl isocyanurate resin, a triallyl cyanurate resin, and vinyl. The thermosetting resin composition according to any one of the above [1] to [3], which is one or more selected from the group consisting of group-containing polyolefin resins.
[5] The component (C) is represented by the structural unit (c1) represented by the following general formula (c1), the structural unit (c2) represented by the following general formula (c2), and the following general formula (c3). The thermosetting resin composition according to any one of the above [1] to [4], which comprises the structural unit (c3) to be formed and the structural unit (c4) represented by the following general formula (c4).

(R ^c1 represents a hydrogen atom or a methyl group, and R ^c2 represents a hydrocarbon group having 1 to 3 carbon atoms.)

(R ^c3 represents a hydrogen atom or a methyl group, and R ^c4 represents a hydrocarbon group having 5 to 22 carbon atoms including an alicyclic hydrocarbon group.)

(R ^c5 represents a hydrogen atom or a methyl group, and R ^c6 represents a chain hydrocarbon group having 4 to 10 carbon atoms.)

(R ^c7 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Z represents a hydroxy group or consists of a carboxy group, a hydroxy group, an acid anhydride group, an amino group, an amide group and an epoxy group. Indicates a substituent containing one or more functional groups selected from the group.)
[6] The content of the structural unit (c1) in the component (C) is 1 to 60% by mass, the content of the structural unit (c2) is 1 to 20% by mass, and the content of the structural unit (c3) is contained. The thermocurable resin composition according to the above [5], wherein the amount is 5 to 90% by mass and the content of the structural unit (c4) is 1 to 20% by mass.
[7] Further, the above [1] further contains (A2) a phenolic resin having an aliphatic hydrocarbon group having 10 to 25 carbon atoms, which is a combination of a chain aliphatic hydrocarbon group and a cyclic aliphatic hydrocarbon group. ] To [6]. The heat-curable resin composition according to any one of.
[8] The above-mentioned [7], wherein the content ratio of the component (A1) to the component (A2) [(A1) component / (A2) component] is 0.1 to 1 on a mass basis. Thermosetting resin composition.
[9] The component (D) is a copolymer resin having a structural unit represented by the following general formula (Di) and a structural unit represented by the following formula (D-ii). ] To [8]. The thermosetting resin composition according to any one of.

(In the formula, ^RD1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and ^RD2 is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, and 6 to 20 carbon atoms. It is an aryl group, a hydroxyl group or a (meth) acryloyl group. X is an integer of 0 to 3. However, when x is 2 or 3, a plurality of R ^D2s may be the same or different. May be.)
[10] The thermosetting resin composition according to the above [9], wherein ^RD1 is a hydrogen atom and x is 0 in the general formula (Di).
[11] In the component (D), the content ratio of the structural unit derived from the aromatic vinyl compound and the structural unit derived from maleic anhydride [Structural unit derived from the aromatic vinyl compound / structural unit derived from maleic anhydride ] (Mole ratio) of 1 to 9, the thermocurable resin composition according to any one of the above [1] to [10].
[12] In the component (D), the content ratio of the structural unit derived from the aromatic vinyl compound and the structural unit derived from maleic anhydride [Structural unit derived from the aromatic vinyl compound / structural unit derived from maleic anhydride ] (Mole ratio) is 3 to 7, the thermosetting resin composition according to any one of the above [1] to [11].
[13] The thermosetting resin composition according to any one of the above [1] to [12], wherein the weight average molecular weight of the component (D) is 4,500 to 18,000.
[14] The thermosetting resin composition according to any one of the above [1] to [13], wherein the weight average molecular weight of the component (D) is 9,000 to 13,000.
[15] The thermosetting resin composition according to any one of [1] to [14] above, wherein the cured product does not have a phase-separated structure.
[16] The thermosetting resin composition according to any one of [1] to [14] above, wherein the cured product has a phase-separated structure.
[17] A prepreg containing the thermosetting resin composition according to any one of the above [1] to [16].
[18] A metal foil with a resin obtained by laminating the thermosetting resin composition according to any one of the above [1] to [16] and the metal foil.
[19] A laminate containing the prepreg according to the above [17] or the metal foil with a resin according to the above [18].
[20] A printed wiring board containing the laminate according to the above [19].
[21] A semiconductor package comprising the printed wiring board according to the above [20].

According to the present invention, a thermosetting resin composition having sufficient heat resistance and low elastic coefficient and having high adhesive strength with a metal foil in a normal temperature environment and a high temperature environment, the thermosetting resin composition. It is possible to provide a prepreg, a metal foil with a resin, a laminate, a printed wiring board, and a semiconductor package used.

Hereinafter, one embodiment of the present invention will be described in detail, but the present invention is not limited to the following embodiments.
In the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. Further, the lower limit value and the upper limit value of the numerical range are arbitrarily combined with the lower limit value and the upper limit value of the other numerical range, respectively.
Further, as for each component and material exemplified in the present specification, one type may be used alone or two or more types may be used in combination unless otherwise specified. In the present specification, the content of each component in the composition is the total amount of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means.
Further, when the illustrated and the aspects described as preferable are a collection of choices, any number of arbitrary choices can be extracted from the aggregate, and the extracted choices will be described elsewhere. It can also be arbitrarily combined with the mode to be used.
The present invention also includes aspects in which the items described in the present specification are arbitrarily combined.
In addition, in this embodiment, "(meth) acrylic" means one or more kinds selected from the group consisting of "acrylic" and "methacryl", and the same applies to other similar terms.
The normal temperature in the present embodiment is typically 25 ° C, and the high temperature is typically 125 ° C.

[Thermosetting resin composition]
The thermosetting resin composition of the present embodiment is
(A) Phenolic resin (hereinafter, also referred to as "(A) component"),
(B) Thermosetting resin (hereinafter, also referred to as "(B) component"),
A copolymer resin having (C) an acrylic polymer (hereinafter, also referred to as “component (C)”) and (D) a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride (hereinafter, Also called "(D) component"),
A thermosetting resin composition containing the above, wherein the component (A) is a phenolic resin (A1) having a chain aliphatic hydrocarbon group having 10 to 25 carbon atoms (hereinafter, "component (A1)"). It is a thermosetting resin composition containing (also referred to as).

The thermosetting resin composition of the present embodiment has a high glass transition temperature (Tg), has sufficient heat resistance and a low elastic modulus, and has a high adhesive strength with a metal foil because of the above configuration. To have.
The thermosetting resin composition of the present embodiment contains, in addition to the component (B), which is a thermosetting resin, a component (A1) having both heat curability and low elasticity, and a component (C). It achieves both high heat resistance and low elasticity, and improves the high extensibility of the cured product. Further, by containing the component (D), it has a high Tg, and the component (D) reacts with the component (A) to generate a carboxylic acid group, so that the adhesive strength with the metal foil is improved. It is presumed to be. The exact mechanism by which high Tg is obtained is unknown, but the reaction of component (D) with component (B) to form an ester group resulted in the achievement of high Tg.
By improving the high extensibility, the "stress at the adhesive interface between the thermosetting resin composition and the metal foil" generated due to the thermal history is effectively alleviated, so that the adhesive strength with the metal foil can be increased. It is presumed that it could be achieved.

The thermosetting resin composition of the present embodiment having the above-mentioned effect is a composition particularly useful for prepregs, laminates, metal foils with resin, and the like used for printed wiring boards. Therefore, the thermosetting resin composition of the present invention is a thermosetting resin composition for an interlayer insulating layer, more specifically, a thermosetting resin composition for an interlayer insulating layer of a printed wiring board or a flexible printed wiring board. It is also useful as a thermosetting resin composition for an interlayer insulating layer.
Hereinafter, each component contained in the thermosetting resin composition of the present embodiment will be described.

[(A) Phenolic resin]
The (A) phenol-based resin contains (A1) a phenol-based resin having a chain-aliphatic hydrocarbon group having 10 to 25 carbon atoms, and further (A2) cyclic with the (A2) chain-aliphatic hydrocarbon group. It is preferable to contain a phenolic resin having an aliphatic hydrocarbon group having 10 to 25 carbon atoms, which is a combination with an aliphatic hydrocarbon group (hereinafter, also referred to as “(A2) component”).
Hereinafter, the chain aliphatic hydrocarbon group having 10 to 25 carbon atoms of the component (A1) is referred to as “hydrocarbon group a1”, and the chain aliphatic hydrocarbon group and the cyclic aliphatic hydrocarbon group of the component (A2) are used. The aliphatic hydrocarbon group having 10 to 25 carbon atoms, which is a combination of the above, may be referred to as "hydrocarbon group a2". Here, the "carbon number 10 to 25" in the component (A2) means that the total carbon number of the chain aliphatic hydrocarbon group and the cyclic aliphatic hydrocarbon group is 10 to 25. ..
In addition, in this specification, a "chain" means a linear or a branched chain.

The hydrocarbon group a1 contained in the component (A1) preferably has 10 to 20, more preferably 12 to 20, still more preferably 12 to 18, still more preferably 14 to 18, particularly preferably 14 to 16. Most preferably, it is 15.
The hydrocarbon group a2 contained in the component (A2) has preferably 10 to 18 carbon atoms, more preferably 10 to 15 carbon atoms, still more preferably 10 to 13 carbon atoms, particularly preferably 10 to 12 carbon atoms, and most preferably 11 carbon atoms.
When the carbon numbers of the hydrocarbon groups a1 and a2 are in the above range, the obtained cured product has both high heat resistance and low elasticity, and has excellent high extensibility.

The hydrocarbon groups a1 and a2 may be saturated aliphatic hydrocarbon groups or unsaturated aliphatic hydrocarbon groups. The number of unsaturated bonds contained in the unsaturated aliphatic hydrocarbon group may be one, two or more, and usually five or less, or three. It may be as follows.

As the phenolic resin (A), a component (A1) having a saturated aliphatic hydrocarbon group as the hydrocarbon group a1 and a component (A1) having an unsaturated aliphatic hydrocarbon group as the hydrocarbon group a1 are used in combination. It is also preferable. When these are used in combination, the mass ratio of the component (A1) having an unsaturated aliphatic hydrocarbon group to the total of both may be 60% by mass or more, 80% by mass or more, or It may be 90% by mass or more. Further, the upper limit of the mass ratio is not particularly limited and may be 98% by mass or less. Examples of the (A) phenolic resin in such an embodiment include phenolic resins having a structural unit derived from cardanol.

Examples of the hydrocarbon group a1 which is a saturated aliphatic hydrocarbon group include various decyl groups (“various” means a linear or branched chain, and the same applies hereinafter) and various undecyl groups (hereinafter, the same applies). For example, 4-pentylcyclohexyl group and the like are included), various dodecyl groups, various tetradecyl groups, various pentadecyl groups, various hexadecyl groups, various octadecyl groups, various eicosyl groups and the like.
Examples of the hydrocarbon group a1 which is an unsaturated aliphatic hydrocarbon group include those in which at least a part of the saturated aliphatic hydrocarbon groups having 10 to 25 carbon atoms has a carbon-carbon unsaturated bond. For example, if the number of carbon atoms is 15, 8-pentadecene-1-yl group, 8,11-pentadecadien-1-yl group, 8,11,14-pentadecatorien-1-yl group and the like can be mentioned.

From the viewpoint of low elasticity, the chain-like portion of the hydrocarbon group a2 is preferably linear with 4 or more carbon atoms, and more preferably linear with 5 or more carbon atoms. The combination of the chain and the ring is not particularly limited, and may be-chain-ring, -ring-chain, or-chain-cyclic-chain. It is good, but it is preferably -cyclic-chain. Specific examples of the -cyclic-chain form include 4-pentylcyclohexyl group (C11), 4-octylcyclohexyl group (C14), 4-decylcyclohexyl group (C16), 4-pentylcyclooctyl group (C13), and the like. 4-octylcyclooctyl group (C16) and the like can be mentioned. Among these, a 4-pentylcyclohexyl group (C11) is preferable as the-cyclic-chain form.

The hydrocarbon group a1 and the hydrocarbon group a2 are preferably substituted at the meta position (3rd or 5th position) with respect to the position (1st position) where the hydroxy group of the phenol moiety is bonded.

The components (A1) and (A2) are structural units (a1) represented by the following general formula (a1) and structural units represented by the following general formula (a2) from the viewpoint of low elasticity and low hygroscopicity. It is preferable to have at least one structural unit selected from the group consisting of (a2). It can be said that the component (A1) and the component (A2) have at least one structural unit (a2).

(In the above general formula, R ¹ has a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms which may have a substituent, and 5 to 15 ring-forming atoms which may have a substituent. Indicates an aromatic hydrocarbon group of the above, or a combination of the aliphatic hydrocarbon group and the aromatic hydrocarbon group. R ² represents an aliphatic hydrocarbon group having 10 to 25 carbon atoms (A1). ) in the case of the component, R ² represents a chain aliphatic hydrocarbon group having 10 to 25 carbon atoms, (A2) in the case of the component, R ² is a chain aliphatic hydrocarbon group and cyclic aliphatic Indicates an aliphatic hydrocarbon group having 10 to 25 carbon atoms, which is a combination with a group hydrocarbon group. X indicates a hydrogen atom, a hydroxy group or a hydroxymethyl group. M and n are 0 or 1 independently of each other. Is.)

In the general formulas (a1) and (a2), "-*" indicates a bond. At least one of the three bonds in the general formula (a1) is combined with another structural unit, and at least one of the three bonds in the general formula (a2) is combined with another structural unit. Of the bonds in each equation, the bonds that do not bond with the bonds of other structural units bind to the hydrogen atom.
However, the benzene ring in the structural unit (a1) and the benzene ring in the structural unit (a2) are bonded via a methylene group and are not directly bonded. Further, when two or more structural units (a1) are contained in the same molecule and the structural units (a1) are bonded to each other, the benzene ring in each structural unit (a1) is bonded via a methylene group. Do not join directly. Similarly, when there are two or more structural units (a2) in the same molecule and the structural units (a2) are bonded to each other, the benzene rings in each structural unit (a2) are bonded via a methylene group. , Do not join directly.

That is, the bond extending from the benzene ring in the general formula (a1) is bonded to another structural unit or a hydrogen atom. When bound to another structural unit, the bond is attached to the methylene group of the other structural unit (another structural unit (a1) or a structural unit (a2) in which at least one of m and n is 1). To do.
The bond extending from the methylene group in the general formula (a1) is bonded to the benzene ring of another structural unit (structural unit (a2) or another structural unit (a1)).

The bond extending from the benzene ring in the general formula (a2) is bonded to another structural unit or a hydrogen atom. When bound to another structural unit, the bond is attached to the methylene group of the other structural unit (structural unit (a1) or another structural unit (a2) in which at least one of m and n is 1). To do.
When m in the general formula (a2) is 0 (or n is 0), − (CH ₂ ) _m − * (or − (CH ₂ ) _n − *) is the same as the bond extending from the benzene ring. Indicates the bond (-*) of.
That is, it binds to another structural unit or to a hydrogen atom. When bonded to another structural unit, the bond binds to the methylene group of the other structural unit in the same manner as the bond extending from the benzene ring.
When m is 1 (or n is 1) in the general formula (a2), − (CH ₂ ) _m − * (or − (CH ₂ ) _n − *) is a methylene group, and the bond is a methylene group. It binds to the benzene ring of another structural unit (structural unit (a1) or another structural unit (a2)).

In the general formula (a1), the bond position of R ^{1 on} the benzene ring is orthoto with respect to the position (1 position) where the hydroxy group is bonded from the viewpoint of low cost and the viewpoint that the synthesized resin is easily liquefied. The rank (2nd or 6th) is preferable, and in this case, the general formula (a1) is represented by the following general formula (a1-1) or (a1-2), respectively.

(In the general formulas (a1-1) and (a1-2), R ¹ is the same as R ¹ in the general formula (a1).)
Note that * in the general formulas (a1-1) and (a1-2) will be described in the same manner as in the above description of * in the general formula (a1).
In the present specification, the description regarding the structural unit (a1) can be read as the structural unit (a1-1) or the structural unit (a1-2).

In the general formula (a1), the single bond and the bond position of the methylene group on the benzene ring are not particularly limited. Typically, it is either the ortho position (2 or 6 position) or the para position (4 position) with respect to the position (1 position) to which the hydroxy group is bonded.

In the above formula, the aliphatic hydrocarbon group represented by R ¹ may be chain (linear, branched chain), cyclic, or a combination of chain and cyclic, but it must be chain. Is preferable, and linearity is more preferable.
Further, the aliphatic hydrocarbon group may be either a saturated aliphatic hydrocarbon group having 1 to 9 carbon atoms or an unsaturated aliphatic hydrocarbon group having 2 to 9 carbon atoms. The saturated aliphatic hydrocarbon group having 1 to 9 carbon atoms is preferably a saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, more preferably a saturated aliphatic hydrocarbon group having 1 to 5 carbon atoms, and further preferably carbon. It is a saturated aliphatic hydrocarbon group of numbers 1 to 3. The unsaturated aliphatic hydrocarbon group having 2 to 9 carbon atoms is preferably an unsaturated aliphatic hydrocarbon group having 2 to 6 carbon atoms, and more preferably an unsaturated aliphatic hydrocarbon group having 2 to 4 carbon atoms. , More preferably an unsaturated aliphatic hydrocarbon group having 3 carbon atoms, and particularly preferably an allyl group.
The aliphatic hydrocarbon group represented by R ¹ may have a substituent, and examples of the substituent include a hydroxy group, a halogen atom, an oxygen-containing hydrocarbon group, a nitrogen-containing cyclic group and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the oxygen-containing hydrocarbon group include an ether bond-containing hydrocarbon group. Examples of the nitrogen-containing cyclic group include a pyridyl group, a pyrimidinyl group, a quinolinyl group, an imidazolyl group and the like.

The aromatic hydrocarbon group indicated by R ¹ may be an aromatic hydrocarbon group (aryl group) containing no complex atom, or a heteroaromatic hydrocarbon group (heteroaryl group) containing a complex atom. Although it may be used, an aromatic hydrocarbon group (aryl group) containing no complex atom is preferable. The aromatic hydrocarbon group has 5 to 15 ring-forming atoms, and in the present specification, the “ring-forming atom number” refers to the atom forming the aromatic ring (for example, carbon atom, nitrogen atom, oxygen). It refers to the number of atoms (such as atoms) and does not include the number of atoms (for example, hydrogen atoms, methyl groups, etc.) that are substituted for aromatic rings. For example, both the phenyl group and the tolyl group have 6 ring-forming carbon atoms.
The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 5 to 12 ring-forming atoms, more preferably an aromatic hydrocarbon group having 6 to 12 ring-forming atoms, and even more preferably a ring. It is an aromatic hydrocarbon group having 6 to 10 atoms.
The aromatic hydrocarbon group may have a substituent, and examples of the substituent include an aliphatic hydrocarbon group having 1 to 5 carbon atoms, a hydroxy group, a halogen atom and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The combination of the aliphatic hydrocarbon group shown by R ¹ and the aromatic hydrocarbon group includes-aliphatic hydrocarbon group-aromatic hydrocarbon group, -aromatic hydrocarbon group-aliphatic hydrocarbon group,-. Aliphatic hydrocarbon groups-aromatic hydrocarbon groups-aliphatic hydrocarbon groups and the like can be mentioned. Among these, -aliphatic hydrocarbon group-aromatic hydrocarbon group, so-called aralkyl group, is preferable. The aromatic hydrocarbon group and the aliphatic hydrocarbon group are described in the same manner as the aliphatic hydrocarbon group and the aromatic hydrocarbon group indicated by R1 described above.

X is a hydrogen atom, a hydroxy group or a hydroxymethyl group, preferably a hydrogen atom or a hydroxymethyl group.

Aliphatic hydrocarbon group having 10 to 25 carbon atoms represented by R ² is described in the same manner as hydrocarbon radicals a1 and a hydrocarbon group a2 described above. The R ² is preferably substituted with a meta position (3 or 5 position) with respect to the position (1 position) to which the hydroxy group of the phenol moiety is bonded. In this case, the following general formula (a2-) is used, respectively. It is represented by 1) or (a2-2).

(In the general formulas (a2-1) and (a2-2), X and R ² are the same as X and R ² in the general formula (a2).)
Note that * in the general formulas (a2-1) and (a2-2) is described in the same manner as the above description of * in the general formula (a2).
In the present specification, the description regarding the structural unit (a2) can be read as the structural unit (a2-1) or the structural unit (a2-2).

When the component (A1) and the component (A2) have a structural unit (a1) and a structural unit (a2), the structural unit (a1) and the structural unit (a2) may be one kind for each. There may be two or more types.
The molar ratio of the structural unit (a1) to the structural unit (a2) in the component (A1) and the component (A2) (structural unit (a1) / structural unit (a2)) is (B) thermosetting property described later. From the viewpoint of reactivity with the resin, low elasticity and low moisture absorption, it is preferably 0 to 5.0, more preferably 0.25 to 5.0, still more preferably 1.0 to 3.0, and particularly preferably. It is 1.0 to 2.0.

The weight average molecular weight (Mw) of the component (A1) and the component (A2) is preferably 4,000 or less, more preferably 1,000 to 3,000, still more preferably 1,200 to 2, from the viewpoint of compatibility. It is 000. When the weight average molecular weight is 1,000 or more, (B) the reactivity with the thermosetting resin is excellent, the heat resistance is not impaired, and the melt viscosity tends to be maintained.
In the present specification, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) analysis using tetrahydrofuran (THF) as a solution, and is a standard polystyrene-equivalent value. The weight average molecular weight (Mw) is more specifically measured according to the method described in the Examples.
The hydroxyl group equivalents of the components (A1) and (A2) are preferably 100 to 350 g / eq, more preferably 150 to 300 g / eq, still more preferably 200 to 250 g / eq, from the viewpoint of improving Tg and improving insulating properties. eq. Hydroxy group equivalents are measured according to the method described in Examples.

(Production method of (A1) component and (A2) component)
The method for producing the component (A1) and the component (A2) is not particularly limited, and a known method for producing a phenolic resin can be adopted. For example, the method for producing a multivalent hydroxy resin described in JP-A-2015-89940 can be referred to and applied.
As one aspect of a preferable production method, for example, a phenolic compound represented by the following general formula (2) and formaldehyde are reacted in the presence of a basic catalyst, and the obtained product and the following general formula (1) are reacted. A method of reacting with the phenolic compound represented by (1) in the presence of an acidic catalyst is preferable. The phenolic compound represented by the following general formula (1) forms the structural unit (a1), and the phenolic compound represented by the following general formula (2) forms the structural unit (a2). That is, the components (A1) and (A2) are a structural unit derived from a phenolic compound represented by the following general formula (1) and a structure derived from a phenolic compound represented by the following general formula (2). It is preferable that the unit includes.

(R ¹ in the general formula (1) is the same as R ¹ in the general formula (a1), and R ² and X in the general formula (2) are the same as R ^{1 in the} general formula (a 2). it is the same as R ² and X.)

The content of the component (A1) in the thermosetting resin composition of the present embodiment is not particularly limited, but is preferably 0.1 to 40 parts by mass, more preferably 1 with respect to 100 parts by mass of the total amount of the resin component. It is ~ 20 parts by mass, more preferably 1.5 to 10 parts by mass, and particularly preferably 2.0 to 5 parts by mass. When the content of the component (A1) is at least the above lower limit value, it becomes easier to obtain low elasticity and high extensibility, and when it is at least the above upper limit value, the Tg is further lowered, the flame retardancy is further lowered, and the tack is further reduced. There is a tendency to suppress the increase in sex.
In the present specification, the "total amount of resin components" means the total amount of other components that do not contain an inorganic compound such as (F) filler and an organic solvent, which will be described later, which can be contained as needed. The components (A), (B), (C), (D), and (E) contained as necessary are included.

The content of the component (A2) in the thermosetting resin composition of the present embodiment is not particularly limited, but is preferably 0.1 to 40 parts by mass, more preferably 1 with respect to 100 parts by mass of the total amount of the resin component. It is ~ 30 parts by mass, more preferably 5 to 20 parts by mass, and particularly preferably 10 to 15 parts by mass. When the content of the component (A2) is at least the above lower limit value, it becomes easier to obtain low elasticity and high extensibility, and when it is at least the above upper limit value, the Tg is further lowered, the flame retardancy is further lowered, and the tack is further reduced. There is a tendency to suppress the increase in sex.

The content ratio of the component (A1) to the component (A2) in the thermosetting resin composition of the present embodiment [component (A1) / component (A2)] is preferably 0.1 to 1 on a mass basis. , More preferably 0.15 to 0.6, still more preferably 0.25 to 0.40, and particularly preferably 0.25 to 0.30.

The total amount of the component (A1) and the component (A2) in the phenolic resin (A) is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 100% by mass. Is.

[(B) Thermosetting resin]
As the thermosetting resin (B), a known thermosetting resin can be used, and is not particularly limited. For example, an epoxy resin, an isocyanate resin, a bismaleimide-based compound, or an addition polymerization of a bismaleimide-based compound and a diamine. It is preferably one or more selected from the group consisting of products, isocyanate resins, triallyl isocyanurate resins, triallyl cyanurate resins and vinyl group-containing polyolefin resins. Among these, epoxy resin and cyanate resin are preferable, and epoxy resin is more preferable, from the viewpoint of the balance of performance such as heat resistance and insulation.
As the component (B), one type may be used alone, or two or more types may be used in combination.
In this embodiment, the definition of (B) thermosetting resin does not include component (A).

The epoxy resin is not particularly limited, but an epoxy resin having two or more epoxy groups in one molecule is preferable from the viewpoint of heat resistance and improvement of Tg.
Epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins and the like, and among these, glycidyl ether type epoxy resins are preferable.
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, and phosphorus. Epoxy resin containing epoxy resin, epoxy resin containing naphthalene skeleton, epoxy resin containing aralkyl skeleton, phenol biphenyl aralkyl type epoxy resin, phenol salicylaldehyde novolac type epoxy resin, lower alkyl group substituted phenol salicylaldehyde novolac type epoxy resin, dicyclopentadiene skeleton containing epoxy resin , One or more selected from the group consisting of polyfunctional glycidylamine type epoxy resin, polyfunctional alicyclic epoxy resin and tetrabromobisphenol A type epoxy resin, and tetrabromobisphenol A type epoxy resin is more preferable.

From the viewpoint of compatibility, the epoxy equivalent of the epoxy resin is preferably 200 to 600 g / eq, more preferably 300 to 500 g / eq, and even more preferably 350 to 450 g / eq. The epoxy equivalent is the mass of the resin per epoxy group (g / eq) and can be measured according to the method specified in JIS K7236.

Examples of the cyanate resin include novolak type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, bisphenol F type cyanate resin, tetramethylbisphenol F type cyanate resin, dicyclopentadiene type cyanate resin and the like.

The content of the (B) thermosetting resin in the thermosetting resin composition of the present embodiment is not particularly limited, but is preferably 40 to 90 parts by mass, more preferably 40 parts by mass, based on 100 parts by mass of the total amount of the resin components. It is 50 to 85 parts by mass, more preferably 50 to 70 parts by mass.
The number of phenolic hydroxyl groups of the component (A) with respect to the functional group (for example, epoxy group) of the component (B) is not particularly limited, but is preferably 0.5 to 1.5 equivalents.
When the content of the component (B) is in the above range, the adhesive strength with the metal foil is maintained, and the decrease in Tg and the insulating property tends to be suppressed.

[(C) Acrylic polymer]
The acrylic polymer (C) is not particularly limited as long as it is obtained by polymerizing a monomer having a (meth) acryloyl group, but the structural unit (c1) represented by the following general formula (c1) and the following general It is preferable to include the structural unit (c2) represented by the formula (c2), the structural unit (c3) represented by the following general formula (c3), and the structural unit (c4) represented by the following general formula (c4). ..

(R ^c1 represents a hydrogen atom or a methyl group, and R ^c2 represents a hydrocarbon group having 1 to 3 carbon atoms.)

(R ^c3 represents a hydrogen atom or a methyl group, and R ^c4 represents a hydrocarbon group having 5 to 22 carbon atoms including an alicyclic hydrocarbon group.)

(R ^c5 represents a hydrogen atom or a methyl group, and R ^c6 represents a chain hydrocarbon group having 4 to 10 carbon atoms.)

(R ^c7 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Z represents a hydroxy group or consists of a carboxy group, a hydroxy group, an acid anhydride group, an amino group, an amide group and an epoxy group. Indicates a substituent containing one or more functional groups selected from the group.)

(Structural unit represented by the general formula (c1))
Examples of the hydrocarbon group having 1 to 3 carbon atoms represented by R ^c2 in the general formula (c1) include a methyl group, an ethyl group, a propyl group and the like.
When the component (C) contains the structural unit (c1), the component (C) has excellent heat resistance. When the component (C) contains a plurality of structural units (c1), the plurality of structural units (c1) may be the same or different.

The structural unit (c1) is a (meth) acrylic acid ester having a hydrocarbon group having 1 to 3 carbon atoms (hereinafter, "single") as one of the monomer components used for polymerization for obtaining the component (C). By using a "mer (c1)"), it can be obtained as a structural unit derived from the monomer.
Examples of the monomer (c1) include methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate. One of these may be used alone, or two or more thereof may be used in combination.
As the monomer (c1), a methacrylic acid ester is preferable, and methyl methacrylate is more preferable, from the viewpoint of hygroscopicity.

(Structural unit represented by the general formula (c2))
The number of carbon atoms of the hydrocarbon group containing the alicyclic hydrocarbon group represented by R ^c4 in the general formula (c2) is 5 to 22, preferably 6 to 15, and more preferably 7 to 10. When the number of carbon atoms is not less than the above lower limit, the chemical stability of the monomer is sufficient, and the effect of reducing the hygroscopicity of the component (C) is sufficient. When the number of carbon atoms is 22 or less, the chemical stability of the component (C) is sufficient. Tg is sufficient.
Examples of the alicyclic hydrocarbon group include a cyclohexyl group, a norbornyl group, a tricyclodecanyl group, an isobornyl group, an adamantyl group and the like. When the component (C) contains the structural unit (c2), the hygroscopicity can be efficiently reduced and excellent electrolytic corrosion resistance can be obtained.
When the component (C) contains a plurality of structural units (c2), the plurality of structural units (c2) may be the same or different.

The structural unit (c2) is a (meth) acrylic having a hydrocarbon group having 5 to 22 carbon atoms including a cyclic hydrocarbon group as one of the monomer components used for polymerization for obtaining the component (C). By using an acid ester (hereinafter, also referred to as “monomer (c2)”), it can be obtained as a structural unit derived from the monomer.
Examples of the monomer (c2) include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, norbornyl (meth) acrylate, and (meth). ) Norbornylmethyl acrylate, phenylnorbornyl (meth) acrylate, cyanonorbornyl (meth) acrylate, isobornyl (meth) acrylate, bornyl (meth) acrylate, menthyl (meth) acrylate, ( Fentyl acrylate, adamantyl (meth) acrylate, dimethyl adamantyl (meth) acrylate, tricyclo (meth) acrylate [5.2.1.0 ^2,6 ] deca-8-yl, (meth) acrylic acid Examples thereof include tricyclo [5.2.1.0 ^2,6 ] deca-4-methyl and cyclodecyl (meth) acrylate. One of these may be used alone, or two or more thereof may be used in combination.
Among these, from the viewpoint of low moisture absorption and adhesion to metal foil, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, norbornylmethyl (meth) acrylate, ( Tricycloacrylate [5.2.1.0 ^2,6 ] deca-8-yl, (meth) tricycloacrylate [5.2.1.0 ^2,6 ] deca-4-methyl, (meth) Adamantyl acrylate is preferred, and tricycloacrylate [5.2.1. O ^2,6 ] Deca-8-yl is more preferable.

(Structural unit represented by the general formula (c3))
The chain hydrocarbon group represented by R ^c6 in the general formula (c3) has 4 to 10 carbon atoms, preferably 4 to 9, and more preferably 4 to 8. When the number of carbon atoms of the hydrocarbon group is at least the above lower limit value, the flexibility of the elastomer becomes good, and when it is at least the above upper limit value, the electrical insulation property becomes sufficient.
The hydrocarbon group indicated by R ^c6 may be either linear or branched, but from the viewpoint of being less likely to lose mass due to thermal decomposition and having excellent heat resistance, it is linear with 4 to 10 carbon atoms. It is preferably a branched hydrocarbon group that does not have a hydrocarbon group or a tertiary carbon atom.
The hydrocarbon group indicated by R ^c6 is preferably an aliphatic hydrocarbon group, more preferably an alkyl group. Examples of the alkyl group include a butyl group, a pentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a decyl and the like.
When the component (C) contains a plurality of structural units (c3), the plurality of structural units (c3) may be the same or different.

The structural unit (c3) uses a (meth) acrylic acid ester having a hydrocarbon group having 4 to 10 carbon atoms in the ester portion as one of the monomer components used for polymerization for obtaining the component (C). By doing so, it can be obtained as a structural unit derived from the monomer (hereinafter, also referred to as “monomer (c3)”).
Examples of the monomer (c3) include n-butyl (meth) acrylic acid, i-butyl (meth) acrylic acid, sec-butyl (meth) acrylic acid, pentyl (meth) acrylic acid, and (meth) acrylic acid. Examples thereof include n-hexyl, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and decyl (meth) acrylate. One of these may be used alone, or two or more thereof may be used in combination. Among these, 2-ethylhexyl (meth) acrylate and n-butyl (meth) acrylate are preferable, and n-butyl acrylate and 2-ethylhexyl methacrylate are preferable from the viewpoint of the Tg and SP values of the obtained component (C). Is more preferable.

(Structural unit represented by the general formula (c4))
Z in the general formula (c4) contains a hydroxy group or one or more functional groups selected from the group consisting of a carboxy group, a hydroxy group, an acid anhydride group, an amino group, an amide group and an epoxy group. Indicates a substituent.
When the component (C) contains a plurality of structural units (c4), the plurality of structural units (c4) may be the same or different.

The structural unit (c4) is a simple element by using a (meth) acrylic acid ester having a substituent Z in the ester moiety as one of the monomer components used for polymerization for obtaining the component (C). It is obtained as a structural unit derived from a dimer (hereinafter, also referred to as “monomer (c4)”).

Examples of the monomer (c4) having a "hydroxy group" as the substituent Z include unsaturated carboxylic acid monomers such as acrylic acid and methacrylic acid.

Examples of the monomer (c4) having a "substituted group containing a carboxy group" as the substituent Z include 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2-. Examples thereof include carboxy group-containing monomers such as (meth) acryloyloxyethyl hexahydrophthalic acid and 2- (meth) acryloyloxypropyl hexahydrophthalic acid.

Examples of the monomer (c4) having a “hydroxyl group-containing substituent” as the substituent Z include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate. Examples thereof include hydroxy group-containing monomers such as cyclohexanedimethanol mono (meth) acrylate and N-methylol (meth) acrylamide.

Examples of the monomer (c4) having a "substituent containing an acid anhydride group" as the substituent Z include trimellitic anhydride (meth) acryloyloxyethyl ester and cyclohexanetricarboxylic acid anhydride (meth) acryloyloxy. Examples thereof include acid anhydride group-containing monomers such as ethyl ester.

Examples of the monomer (c4) having a "substituent containing an amino group" as the substituent Z include diethylaminoethyl (meth) acrylate and -2,2,6,6-tetramethyl (meth) acrylate. Examples thereof include amino group-containing monomers such as piperidinyl and (meth) acrylic acid-1,2,2,6,6-pentamethylpiperidinyl.

Examples of the monomer (c4) having a "substituted group containing an amide group" as the substituent Z include an amide group-containing monomer such as N- (meth) acryloylglycinamide.

Examples of the monomer (c4) having a “substituent containing an epoxy group” as the substituent Z include glycidyl (meth) acrylate, 2- (2,3-epoxypropoxy) ethyl (meth) acrylate, and 3 -(2,3-epoxypropoxy) propyl (meth) acrylate, 4- (2,3-epoxypropoxy) butyl (meth) acrylate, 5- (2,3-epoxypropoxy) pentyl (meth) acrylate, 6-( 2,3-Epoxypropoxy) hexyl (meth) acrylate, (meth) acrylic acid-3,4-epoxybutyl, (meth) acrylic acid-4,5-epoxypentyl, (meth) acrylic acid-6,7-epoxy Heptyl, (meth) acrylate-3-methyl-3,4-epoxybutyl, (meth) acrylate-4-methyl-4,5-epoxypentyl, (meth) acrylate-5-methyl-5,6- Epoxyhexyl, (meth) acrylate-β-methylglycidyl, (meth) acrylate-3-methyl-3,4-epoxybutyl, (meth) acrylate-4-methyl-4,5-epoxypentyl, (meth) ) An epoxy group-containing monomer such as -5-methyl-5,6-epoxyhexyl acrylate can be mentioned.

One of these monomers (c4) may be used alone, or two or more thereof may be used in combination.
Among these monomers (c4), an epoxy group-containing monomer is preferable, glycidyl (meth) acrylate is more preferable, and glycidyl methacrylate is further preferable, from the viewpoint of storage stability.

The content of each structural unit in the component (C) is not particularly limited, but the content of the structural unit (c1) is 1 to 60% by mass, the content of the structural unit (c2) is 1 to 20% by mass, and the structure. The content of the unit (c3) is preferably 5 to 90% by mass, and the content of the structural unit (c4) is preferably 1 to 20% by mass.
The content of the structural unit (c1) in the component (C) is not particularly limited, but is more preferably 10 to 50% by mass, further preferably 15 to 40% by mass, and particularly preferably 15 to 35% by mass. is there. When the content of the structural unit (c1) is at least the above lower limit value, the Tg and SP values of the obtained component (C) are excellent, and when it is at least the above upper limit value, a low elastic modulus is obtained.
The content of the structural unit (c2) in the component (C) is not particularly limited, but is more preferably 2 to 10% by mass, and further preferably 3 to 7% by mass. When the content of the structural unit (c2) is at least the above lower limit value, hygroscopicity and chemical resistance are excellent, and when it is at least the above upper limit value, the mechanical strength is sufficient and the laser workability of the cured product is also excellent. It will be a laser.
The content of the structural unit (c3) in the component (C) is not particularly limited, but is more preferably 30 to 85% by mass, still more preferably 50 to 80% by mass, from the viewpoint of electrolytic corrosion resistance and flexibility. When the content of the structural unit (c3) is at least the above lower limit value, the electrolytic corrosion resistance is excellent, and when it is at least the above upper limit value, high Tg can be obtained.
The content of the structural unit (c4) in the component (C) is not particularly limited, but is more preferably 2 to 10% by mass, further preferably 3 to 7% by mass, and particularly preferably 3.5 to 6% by mass. is there. When the content of the structural unit (c4) is at least the above lower limit value, the adhesiveness and strength become more sufficient, and when it is at least the above upper limit value, the cross-linking reaction at the time of copolymerization is suppressed and the storage stability is also improved. It will be good.
The content of the other structural unit in the component (C) is not particularly limited, but is preferably 25% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less.

(Method for manufacturing component (C))
The component (C) is preferably obtained by polymerizing a monomer mixture containing the monomer (c1), the monomer (c2), the monomer (c3) and the monomer (c4). ..
The above-mentioned monomer mixture may consist only of a monomer (c1), a monomer (c2), a monomer (c3) and a monomer (c4), but these monomers It may contain other monomers copolymerizable with.
Examples of other monomers include 4-vinylpyridine, 2-vinylpyridine, α-methylstyrene, α-ethylstyrene, α-fluorostyrene, α-chlorostyrene, α-bromostyrene, fluorostyrene, and chlorostyrene. Aromatic vinyl compounds such as, bromostyrene, methylstyrene, methoxystyrene, (o-, m- or p-) hydroxystyrene, styrene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; unsaturated such as maleic anhydride. Dicarboxylic acid anhydrides; N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-i-propylmaleimide, N-butylmaleimide, N-i-butylmaleimide, N-t-butylmaleimide, N-lauryl N-substituted maleimides such as maleimide, N-cyclohexyl maleimide, N-benzylmaleimide, and N-phenylmaleimide; vinyl acetate and the like can be mentioned.
As the other monomers, one type may be used alone, or two or more types may be used in combination.

The amount of each monomer used is preferably adjusted so that the content of each structural unit in the obtained component (C) is within the above range.

As the polymerization method for producing the component (C), existing methods such as bulk polymerization, suspension polymerization, solution polymerization, precipitation polymerization and emulsion polymerization can be applied. Among these, suspension polymerization is preferable from the viewpoint of economy.
Suspension polymerization can be carried out, for example, in an aqueous medium to which a suspending agent has been added. Examples of the suspending agent include water-soluble polymers such as polyvinyl alcohol, methyl cellulose and polyacrylamide; and sparingly soluble inorganic substances such as calcium phosphate and magnesium pyrophosphate. Among these, a nonionic water-soluble polymer such as polyvinyl alcohol is preferable. One type of suspending agent may be used alone, or two or more types may be used in combination.
The amount of the suspending agent used is, for example, 0.01 to 1 part by mass with respect to 100 parts by mass of the total amount of the monomers.

It is preferable to use a radical polymerization initiator for the polymerization for producing the component (C). Examples of the radical polymerization initiator include benzoyl peroxide, lauroyl peroxide, di-t-butylperoxyhexahydroterephthalate, t-butylperoxy-2-ethylhexanoate, and 1,1-t-butylperoxy. Organic peroxides such as -3,3,5-trimethylcyclohexane and t-butylperoxyisopropylcarbonate; azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1- Examples thereof include azo compounds such as carbonitrile and azodibenzoyl; water-soluble catalysts such as potassium persulfate and ammonium persulfate; and redox catalysts using a combination of peroxide or persulfate and a reducing agent. One type of radical polymerization initiator may be used alone, or two or more types may be used in combination.
The amount of the radical polymerization initiator used is, for example, 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the monomers.

A chain transfer agent may be used for the polymerization for producing the component (C) from the viewpoint of adjusting the molecular weight of the obtained component (C). Examples of the chain transfer agent include mercaptan compounds, thioglycols, carbon tetrachloride, α-methylstyrene dimers and the like. One type of chain transfer agent may be used alone, or two or more types may be used in combination.

The polymerization temperature is not particularly limited, but is, for example, 0 to 200 ° C., preferably 40 to 120 ° C. from the viewpoint of reaction rate and productivity.

(Physical properties of component (C))
The weight average molecular weight of the component (C) is not particularly limited, but is preferably 100,000 to 1,000,000, more preferably 200,000 to 900,000, still more preferably 300,000 to 800,000, particularly. It is preferably 450,000 to 650,000, most preferably 500,000 to 600,000. When the weight average molecular weight is at least the above lower limit value, it has a sufficiently low elastic modulus and high adhesive strength with the metal foil is obtained, and when it is at least the above upper limit value, the solubility in a solvent is good and the workability is good. It will be good.

The solubility parameter (SP value) of the component (C) is not particularly limited, but is preferably 10.0 to 12.0, more preferably 10.1 to 11.0, and further preferably 10.2 to 10.5. is there. When the SP value is at least the above lower limit value, the heat resistance tends to be improved, and when it is at least the above upper limit value, the insulation reliability tends to be improved.
The SP value of the component (C) can be calculated from the structure of the material by the Fedors method. From the structure of the material, the total molar aggregation energy and the total molar molecular capacity were obtained by summing the molar agglomeration energy and the molar molecular capacity of each functional group shown in the table below for the number of constituent functional groups. Calculated by the following formula (1).

The symbols in the above formula (1) indicate the SP value in δ _i , the total molar aggregation energy in ΔE _i , and the total molar molecular capacity in ΔV _i , respectively.

Specifically, when the SP value is calculated by the above method using the case of methyl methacrylate as an example, it becomes as follows. In this case, methyl methacrylate
Structural formula: CH _3- C (= CH ₂ ) -C (= O) -O-CH ₃
Number of members: CH ₃ 2
CH ₂ 1 piece
> C <1 piece
> 1 CO
-O- 1 piece, from Table 1
Total molar cohesive energy (ΔE _i ): (1125 × 2) + (1180 × 1) + (350 × 1) + (4150 × 1) + (800 × 1) = 8730
Total molar molecular capacity (ΔV _i ): (33.5 × 2) + (16.1 × 1) + (-19.2 × 1) + (10.8 × 1) + (3.8 × 1) = 78.5
And apply this to equation (1),

And the solubility parameter (SP value) are calculated.
(C) The SP value of the acrylic polymer is calculated from the composition ratio of each monomer. Specifically, as an example of copolymerization with methyl methacrylate / butyl acrylate = 40 by weight, the SP value is calculated as follows. Since the SP value of methyl methacrylate is 10.55 and the SP value of butyl acrylate is 10.21, it is calculated as 10.55 × 0.4 + 10.21 × 0.6 = 10.35.

The content of the component (C) in the thermosetting resin composition of the present embodiment is not particularly limited, but is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the total amount of the resin component. It is by mass, more preferably 10 to 30 parts by mass, and particularly preferably 10 to 20 parts by mass. When the content of the component (C) is at least the above lower limit value, it is excellent in low elasticity, flexibility and high extensibility, and there is a tendency to obtain sufficient adhesive strength with the metal foil, and when it is at least the above upper limit value. , Sufficient heat resistance can be obtained.

[(D) Specific copolymer resin]
The component (D) is a copolymer resin having a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride (hereinafter, may be referred to as a copolymer resin (D)). Examples of the aromatic vinyl compound include styrene, 1-methylstyrene, vinyltoluene, dimethylstyrene and the like. Of these, styrene is preferable.
As the component (D), a copolymer resin having a structural unit represented by the following general formula (Di) and a structural unit represented by the following formula (D-ii) is preferable.

(In the formula, ^RD1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and ^RD2 is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, and 6 to 20 carbon atoms. It is an aryl group, a hydroxyl group or a (meth) acryloyl group. X is an integer of 0 to 3. However, when x is 2 or 3, a plurality of R ^D2s may be the same or different. May be.)

Examples of the alkyl group having 1 to 5 carbon atoms represented by ^RD1 and ^RD2 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group and an n-pentyl group. Group etc. can be mentioned. The alkyl group is preferably an alkyl group having 1 to 3 carbon atoms.
The alkenyl group having 2 to 5 carbon atoms R ^D2 represents, for example, allyl, crotyl and the like. The alkenyl group is preferably an alkenyl group having 3 to 5 carbon atoms, and more preferably an alkenyl group having 3 or 4 carbon atoms.
Examples of the aryl group having 6 to 20 carbon atoms R ^D2 represents, for example, a phenyl group, a naphthyl group, an anthryl group, etc. biphenylyl group. The aryl group is preferably an aryl group having 6 to 12 carbon atoms, and more preferably an aryl group having 6 to 10 carbon atoms.
x is preferably 0 or 1, more preferably 0.
In the structural unit represented by the general formula (D-i), ^RD1 is a hydrogen atom and x is 0, which is derived from the structural unit represented by the following general formula (D-i-1), that is, styrene. The structural unit to be used is preferable.

Content ratio of structural units derived from aromatic vinyl compound and structural units derived from maleic anhydride in the copolymer resin (D) [Structural units derived from aromatic vinyl compound / structural units derived from maleic anhydride] The (molar ratio) is preferably 1 to 9, more preferably 2 to 9, still more preferably 3 to 8, and particularly preferably 3 to 7. Further, the content ratio of the structural unit represented by the general formula (Di) to the structural unit represented by the formula (D-ii) [(Di) / (D-ii)] (molar ratio). Similarly, it is preferably 1 to 9, more preferably 2 to 9, still more preferably 3 to 8, and particularly preferably 3 to 7. When these molar ratios are 1 or more, preferably 2 or more, the Tg of the cured product tends to be high and the effect of improving the dielectric properties tends to be sufficient, and when these are 9 or less, the compatibility is good. It tends to be.
The total content of the structural unit derived from the aromatic vinyl compound and the structural unit derived from maleic anhydride in the copolymer resin (D), and the structural unit and formula represented by the general formula (Di). The total content with the structural unit represented by (D-ii) is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, and particularly preferably substantially 100. It is mass%.
The weight average molecular weight (Mw) of the copolymerized resin (D) is preferably 4,500 to 18,000, more preferably 5,000 to 18,000, more preferably 6,000 to 17,000, and even more preferably 6,000 to 17,000. It is 8,000 to 16,000, particularly preferably 8,000 to 15,000, and most preferably 9,000 to 13,000.

By using the copolymer resin (D), the Tg of the cured product is increased, and the ester group is generated by the reaction between the copolymer resin (D) and the component (A), so that the adhesive strength with the metal foil is improved. To do. The present invention has a thermosetting resin composition having low elasticity, high extensibility and high Tg by containing the copolymer resin (D) together with the component (A), the component (B) and the component (C). It was achieved when it turned out to be a thing.

(Manufacturing method of copolymer resin (D))
The copolymerized resin (D) can be produced by copolymerizing an aromatic vinyl compound and maleic anhydride.
Examples of the aromatic vinyl compound include styrene, 1-methylstyrene, vinyltoluene, dimethylstyrene and the like, as described above. One of these may be used alone, or two or more thereof may be used in combination.
Further, in addition to the aromatic vinyl compound and maleic anhydride, various polymerizable components may be copolymerized. Examples of various polymerizable components include vinyl compounds such as ethylene, propylene, butadiene, isobutylene and acrylonitrile; and compounds having a (meth) acryloyl group such as methyl acrylate and methyl methacrylate.
Further, a substituent such as an allyl group, a methacryloyl group, an acryloyl group or a hydroxy group may be introduced into the aromatic vinyl compound through a Friedel-Crafts reaction or a reaction using a metal catalyst such as lithium.

As the copolymerization resin (D), a commercially available product can also be used. Examples of commercially available products include "SMA (registered trademark) 1000" (styrene / maleic anhydride = 1, Mw = 5,500) and "SMA (registered trademark) EF30" (styrene / maleic anhydride = 3, Mw = 9). , 500), "SMA (registered trademark) EF40" (styrene / maleic anhydride = 4, Mw = 11,000), "SMA (registered trademark) EF60" (styrene / maleic anhydride = 6, Mw = 11,500) ), "SMA (registered trademark) EF80" (styrene / maleic anhydride = 8, Mw = 14,400) [above, manufactured by CRAY VALLEY] and the like.

[(E) Curing accelerator]
The thermosetting resin composition of the present embodiment further preferably contains (E) a curing accelerator. The (E) curing accelerator can be appropriately selected depending on the type of (B) thermosetting resin, and one type may be used alone or two or more types may be used in combination.
For example, when an epoxy resin is used as the component (B), the curing accelerator (E) is not particularly limited, but an amine compound and an imidazole compound are preferable, and an imidazole compound is more preferable.
Examples of the amine compound include dicyandiamide, diaminodiphenylethane, guanylurea and the like.
Examples of the imidazole compound include 2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium tri. Examples thereof include meritate and benzimidazole. Among these, an imidazole compound is preferable, and 2-phenylimidazole is more preferable.
When the thermosetting resin composition of the present embodiment contains (E) a curing accelerator, the content of the (E) curing accelerator is not particularly limited, but is based on 100 parts by mass of the total amount of the (B) component. It is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, and further preferably 0.05 to 3 parts by mass.

[(F) Filler]
The thermosetting resin composition of the present embodiment preferably further contains (F) filler.
As the filler (F), one type may be used alone, or two or more types may be used in combination.
The filler (F) is not particularly limited, and known fillers can be used. The filler (F) may be an organic filler or an inorganic filler, but an inorganic filler is preferable from the viewpoint of low coefficient of thermal expansion and flame retardancy.
Examples of the inorganic filler include silica, alumina, titanium oxide, mica, berylia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, and carbonic acid. Calcium, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay (baked clay, etc.), talc, aluminum borate, silicon carbide and the like can be mentioned. Among these, silica is preferable from the viewpoint of low dielectric constant and low coefficient of thermal expansion. Examples of silica include precipitated silica manufactured by a wet method and having a high water content, dry silica manufactured by a dry method and containing almost no bound water, and the like. Further examples of dry silica include those produced by the manufacturing method. Depending on the difference, crushed silica, fumed silica, fused silica (molten spherical silica) and the like can be mentioned. Among these, fused silica (molten spherical silica) and pulverized silica are preferable.

The average particle size of the filler (F) is not particularly limited, but is preferably 0.1 to 10 μm, and more preferably 0.3 to 4.0 μm. When the average particle size is 0.1 μm or more, the dispersibility between the fillers tends to be good, and the handleability tends to be good due to the decrease in the viscosity of the varnish. Further, when the average particle size is 10 μm or less, the (F) filler tends to be less likely to settle during varnishing. Here, the average particle size is the particle size of a point corresponding to a volume of 50% when the cumulative frequency distribution curve by the particle size is obtained with the total volume of the particles as 100%, and the laser diffraction scattering method is used. It can be measured with the particle size distribution measuring device or the like.

The filler (F) may be surface-treated with a coupling agent from the viewpoint of improving the dispersibility, the adhesion of the prepreg to the substrate, and the adhesion to the metal foil.
As the coupling agent, a silane coupling agent is preferable, and examples of the silane coupling agent include an epoxysilane-based coupling agent, an aminosilane-based coupling agent, a vinylsilane-based coupling agent, a phenylsilane-based coupling agent, and the like. Can be mentioned. Among these, an aminosilane-based coupling agent is preferable. One type of coupling agent may be used alone, or two or more types may be used in combination.
When a coupling agent is used, a so-called integral blend treatment method in which the filler (F) is mixed in the thermosetting resin composition and then the coupling agent is added may be used, but the coupling agent may be used in advance. It is preferable to use a filler (F) whose surface is treated by a dry method or a wet method.

When the thermosetting resin composition of the present embodiment contains the (F) filler, the content of the (F) filler is not particularly limited, but is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the total amount of the resin components. Parts, more preferably 20 to 100 parts by mass, still more preferably 30 to 70 parts by mass. When the content of the filler (F) is at least the above lower limit value, it is excellent in low thermal expansion, heat resistance and low tackiness, and when it is at least the above upper limit value, a low elastic effect tends to be sufficiently obtained.

[Other ingredients]
The thermosetting resin composition of the present embodiment is, if necessary, a curing agent for the component (B) (excluding the component (A)); a cross-linking agent such as isocyanate and melamine; a rubber-based elastoma; It may contain a flame retardant such as a phosphorus compound; conductive particles; a coupling agent; a flow conditioner; an antioxidant; a pigment; a leveling agent; an antifoaming agent; an ion trapping agent or the like.

〔Organic solvent〕
The thermosetting resin composition of the present embodiment may be a varnish-like thermosetting resin composition containing an organic solvent from the viewpoint of facilitating the production of the prepreg described later. The organic solvent may contain the organic solvent used in producing the component (A), the component (B), or the like as it is, or may be newly blended.
The organic solvent is not particularly limited, and examples thereof include a ketone solvent, an aromatic hydrocarbon solvent, an ester solvent, an amide solvent, and an alcohol solvent. Among these, a ketone solvent is preferable from the viewpoint of solubility. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like. As the organic solvent, one type may be used alone, or two or more types may be used in combination.
The varnish preferably has a non-volatile content concentration of 25 to 65% by mass from the viewpoints of handleability, impregnation of the prepreg into the base material, and appearance of the prepreg. In the present specification, the “nonvolatile component” refers to a component remaining when the organic solvent contained in the thermosetting resin composition is removed, and the above-mentioned filler (F) is also included.

(Storage modulus)
The storage elastic modulus of the cured product (laminated plate) obtained from the thermosetting resin composition of the present embodiment is not particularly limited, but is preferably 4.0 GPa or less, more preferably 3 from the viewpoint of exhibiting a stress relaxation effect. It is 0.7 GPa or less, more preferably 3.2 GPa or less, particularly preferably 2.7 GPa or less, and most preferably 2.4 or less. The lower limit of the storage elastic modulus is not particularly limited, and may be 1.0 GPa or more, 1.5 GPa or more, or 1.8 GPa or more. The storage elastic modulus can be measured by the method described in Examples.

(Tensile elongation rate)
The tensile elongation at 25 ° C. of the cured product (laminated plate) obtained from the thermosetting resin composition of the present embodiment is not particularly limited, but is preferably 2.5% or more from the viewpoint of ensuring long-term reliability. It is more preferably 2.8% or more, further preferably 3.0% or more, and particularly preferably 3.1% or more. The upper limit of the tensile elongation at 25 ° C. is not particularly limited, but may be 6.0% or less, 5.0% or less, or 4.0% or less. It may be 3.5% or less.
The tensile elongation at 125 ° C. is not particularly limited, but from the viewpoint of exhibiting a stress relaxation effect in a high temperature environment and resilience to thermal expansion when a temperature change occurs between a normal temperature environment and a high temperature environment. , Preferably 6.0% or more, more preferably 8.0% or more, still more preferably 9.0% or more, even more preferably 9.5% or more, particularly preferably 9.7% or more, most preferably 9. It is 8.8% or more. The upper limit of the tensile elongation at 125 ° C. is not particularly limited, but usually, it may be 12.0% or less, 11.0% or less, or 10.5% or less. Good. The tensile elongation can be measured by the method described in Examples.

(Copper foil peeling strength)
In the cured product obtained from the thermosetting resin composition of the present embodiment, the copper foil peeling strength at 25 ° C. is not particularly limited, but when measured according to the method described in Examples, it is preferably 0.80 kN. / M or more, more preferably 0.83 kN / m or more, still more preferably 0.85 kN / m or more. The upper limit of the copper foil peeling strength at 25 ° C. is not particularly limited, but usually, it may be 2.0 kN / m or less, 1.3 kN / m or less, or 1.1 kN / m. It may be m or less.
The peeling strength of the copper foil at 125 ° C. is not particularly limited, but is preferably 0.55 kN / m or more, more preferably 0.57 kN / m or more, and further preferably 0.60 kN / m or more. The upper limit of the copper foil peeling strength at 125 ° C. is not particularly limited, but may be 1.50 kN / m or less, 1.20 kN / m or less, or 1.0 kN / m or less. It may be 0.85 kN / m or less.

(Glass transition temperature (Tg))
In the cured product obtained from the thermosetting resin composition of the present embodiment, the glass transition temperature (Tg) is not particularly limited, but when measured according to the method described in Examples, it is preferably 150 ° C. or higher, more preferably. It is 155 ° C. or higher, more preferably 158 ° C. or higher. The upper limit of Tg is not particularly limited, but usually, it may be 170 ° C. or lower, or 165 ° C. or lower.

The cured product of the thermosetting resin composition of the present embodiment preferably does not have a phase-separated structure from the viewpoint of enhancing the adhesiveness with the metal foil, while it is preferable from the viewpoint of reducing the storage elastic modulus. An embodiment having a phase-separated structure is preferable. When it does not have a phase-separated structure, the elongation rate in a normal temperature environment and a high temperature environment is improved, and thus the stress relaxation effect can be effectively exhibited, so that the adhesiveness with the metal foil can be enhanced. There is a tendency. In the present embodiment, the phase-separated structure is, for example, a sea-island structure, a continuous spherical structure, a composite dispersed phase structure, a co-continuous phase structure, or the like, and the presence or absence of the phase-separated structure is described in Examples. It can be confirmed by the method. As the phase-separated structure in the present embodiment, a sea-island structure is preferable.

[Prepreg]
The prepreg of the present embodiment contains the thermosetting resin composition of the present embodiment.
The prepreg of the present embodiment can be produced by impregnating a base material with the thermosetting resin composition of the present embodiment and drying it.
The base material is not particularly limited as long as it is a base material used for manufacturing a metal-clad laminate or a printed wiring board, but a fiber base material such as a woven fabric or a non-woven fabric is usually used. Examples of the material of the fiber base material include inorganic fibers such as glass, alumina, asbestos, boron, silica-alumina glass, silica glass, tyrano, silicon carbide, silicon nitride, and zirconia; aramid, polyether ether ketone, polyetherimide, etc. Examples thereof include organic fibers such as polyether sulfone, carbon and cellulose; and fibers obtained by mixing these. Among these, glass cloth is preferable. The thickness of the fiber base material is, for example, 160 μm or less, preferably 10 to 160 μm, more preferably 15 to 100 μm, and further preferably 20 to 50 μm.
As the fiber base material, a printed wiring board that can be bent arbitrarily can be obtained, and dimensional changes due to temperature, moisture absorption, etc. in the manufacturing process can be reduced. Therefore, a glass cloth of 50 μm or less can be used. It is preferable to have.

The production conditions of the prepreg are not particularly limited, but it is preferable to volatilize 80% by mass or more of the organic solvent contained in the varnish to obtain the prepreg. The drying temperature is preferably 80 to 180 ° C, more preferably 110 to 160 ° C.

[Metal foil with resin]
The resin-containing metal foil of the present embodiment is formed by laminating the thermosetting resin composition of the present embodiment and the metal foil.
The resin-containing metal foil of the present embodiment can be produced, for example, by applying a varnish-like thermosetting resin composition of the present embodiment to the metal foil and drying it.
The drying conditions are not particularly limited, but the drying temperature is preferably 80 to 180 ° C, more preferably 110 to 160 ° C.
The coating method is not particularly limited, and a known coating machine such as a die coater, a comma coater, a bar coater, a kiss coater, or a roll coater can be used.

[Laminate]
The laminate of the present embodiment contains the prepreg of the present embodiment or the metal foil with resin of the present embodiment.
The laminated body of the present embodiment can be produced, for example, by laminating a plurality of prepregs of the present embodiment and heating and pressurizing them.
The laminate of the present embodiment may contain only the prepreg of the present embodiment as a prepreg, but from a laminate composed of a plurality of prepregs different from the present embodiment and a plurality of prepregs of the present embodiment. It may be a laminate with the laminate. Examples of the laminate composed of a plurality of prepregs different from the present embodiment include a laminate having a higher storage elastic modulus than the laminate composed of a plurality of prepregs of the present embodiment. Since the stress relaxation effect can be obtained by the laminated body composed of a plurality of prepregs of the present embodiment, the printed wiring that can occur when only the laminated body composed of a plurality of prepregs different from the present embodiment is used by this embodiment. The occurrence of cracks in the plate can be suppressed.

The laminate of the present embodiment may be a metal-clad laminate formed by laminating the prepreg and the metal foil of the present embodiment.
The metal-clad laminates are, for example, laminated so that the adhesive surfaces on both sides of the laminate and the metal foil are aligned, and under vacuum press conditions, preferably 130 to 250 ° C., more preferably 150 to 230 ° C., and preferably. Can be produced by heat and pressure molding under the conditions of 0.5 to 10 MPa, more preferably 1 to 5 MPa.
Further, a metal-clad laminate can also be produced by preparing two metal foils with resin of the present embodiment, stacking the resin surfaces so as to face each other, and pressing them under vacuum pressing conditions. The heating and pressurizing method is not particularly limited, and a multi-stage press, a multi-stage vacuum press, continuous molding, an autoclave molding machine, or the like can be used.

The metal foil with resin and the metal foil used for the metal-clad laminate of the present embodiment are not particularly limited, and examples thereof include copper foil and aluminum foil.
The thickness of the metal foil is not particularly limited, but is preferably selected from the range of 1 to 200 μm, which is the thickness of the metal foil generally used for laminated plates, more preferably 10 to 100 μm, and further preferably 10 to 50 μm. Is.

[Printed circuit board]
The printed wiring board of the present embodiment contains the laminated board of the present embodiment.
The printed wiring board of the present embodiment is, for example, formed by circuit processing the laminated board of the present embodiment, and as a manufacturing method thereof, a laminated body of the present embodiment in which metal foil is provided on one side or both sides ( A method of applying a circuit (wiring) process to a metal foil of a metal-clad laminate) by a known method can be mentioned.
The printed wiring board of the present invention may be a flexible printed wiring board.

[Semiconductor package]
The semiconductor package of the present embodiment includes the printed wiring board of the present embodiment. The semiconductor package of the present embodiment can be manufactured by mounting a semiconductor chip, a memory, or the like at a predetermined position of the printed wiring board of the present embodiment by a known method.

Hereinafter, the present embodiment will be specifically described with reference to Examples and Comparative Examples, but the present embodiment is not limited thereto.
The weight average molecular weight and hydroxyl group equivalent of the components used in each example were measured by the following methods.

[1. Weight average molecular weight]
The weight average molecular weight was converted from the calibration curve using standard polystyrene by the gel permeation chromatography (GPC) method. The calibration curve is standard polystyrene: TSK standard POLYSTYRENE (Type; A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation, Product name] was used for approximation by a cubic equation. The measurement conditions of GPC are shown below.
apparatus:
Pump: L-6200 type [manufactured by Hitachi High-Technologies Corporation]
Detector: L-3300 type RI [manufactured by Hitachi High-Technologies Corporation]
Column oven: L-655A-52 [manufactured by Hitachi High-Technologies Corporation]
Column: Guard column; TSK Guardcolum HHR-L + column; TSKgel G4000HHR + TSKgel G2000HHR (all manufactured by Tosoh Corporation, trade name)
Column size: 6.0 mm x 40 mm (guard column), 7.8 mm x 300 mm (column)
Eluent: tetrahydrofuran Sample concentration: 30 mg / 5 mL
Injection volume: 20 μL
Flow rate: 1.00 mL / min Measurement temperature: 40 ° C

[2. Hydroxyvalent equivalent]
The hydroxyl group equivalent (g / eq) of the phenolic resin (A) was determined by titration by an acetylation method using acetic anhydride using an automatic titrator "COM-1700S" (manufactured by Hiranuma Sangyo Co., Ltd.).

[(A) Synthesis of phenolic resin]
Synthesis example 1
((A1) component: synthesis of phenolic resin (A-1))
A glass flask having a content of 2 L equipped with a thermometer, a stirrer and a cooling tube is charged with 300 g (1.0 mol) of cardanol, 150 g of methanol and 120 g (2.0 mol) of a 50% formaldehyde aqueous solution, and 30% water is added to the mixed solution. The aqueous sodium oxide solution was added dropwise over 2 hours. Then, the temperature was raised to 45 ° C. and the reaction was carried out for 6 hours. Next, 35% hydrochloric acid was added to the obtained reaction solution to neutralize sodium hydroxide, then 1,342 g (10 mol) of o-allylphenol was added, and 1.34 g (o-allylphenol) of oxalic acid was added. The inside of the system was made acidic by adding 0.1% by mass), the temperature was raised to 100 ° C., and then the reaction was carried out for 5 hours. Then, the reaction solution was washed with water, and then excess o-allylphenol was distilled off to obtain a phenolic resin (A-1).
The weight average molecular weight (Mw) of the obtained phenolic resin (A-1) was 1,412, and the hydroxyl group equivalent was 214 g / eq.

Synthesis example 2
(Component (A2): Synthesis of phenolic resin (A-2))
248 g (1.0 mol) of p- (4-pentylcyclohexyl) phenol, 150 g of methanol, and 120 g (2.0 mol) of a 50% formaldehyde aqueous solution are charged in a glass flask having a content of 2 L equipped with a thermometer, a stirrer and a cooling tube. , A 30% aqueous sodium hydroxide solution was added dropwise to the mixed solution over 2 hours. Then, the temperature was raised to 45 ° C. and the reaction was carried out for 6 hours. Next, 35% hydrochloric acid was added to the obtained reaction solution to neutralize sodium hydroxide, then 1,342 g (10 mol) of o-allylphenol was added, and 1.34 g (o-allylphenol) of oxalic acid was added. The inside of the system was made acidic by adding 0.1% by mass), the temperature was raised to 100 ° C., and then the reaction was carried out for 5 hours. Then, the reaction solution was washed with water, and then excess o-allylphenol was distilled off to obtain a phenolic resin (A-2).
The weight average molecular weight (Mw) of the obtained phenolic resin (A-2) was 1,738, and the hydroxyl group equivalent was 238 g / eq.

[(C) Synthesis of acrylic polymer]
Synthesis example 3
(Synthesis of acrylic polymer (C-1))
Lauroyl peroxide as a peroxide and n-octyl mercaptan as a chain transfer agent were added to the monomer mixture (1000 g in total) obtained by mixing at the monomer blending ratio (mass basis) shown in Table 2. 0.45 g was dissolved to prepare a mixed solution.
Next, 0.3 g of polyvinyl alcohol and 2,000 g of ion-exchanged water were added as a suspending agent to a 5 L autoclave equipped with a stirrer and a condenser, and the above mixed solution was added while stirring, and the stirring speed was 250 rpm. , Then polymerized at 60 ° C. for 5 hours and then at 90 ° C. for 2 hours in a nitrogen atmosphere to obtain resin particles. The resin particles were washed with water, dehydrated and dried, and dissolved in methyl ethyl ketone so that the heating residue was 30% by mass to obtain a solution of an acrylic polymer (C-1).

Synthesis Examples 4 and 5
(Synthesis of acrylic polymers (C-2) and (C-3))
In Synthesis Example 3, solutions of acrylic polymers (C-2) and (C-3) were obtained in the same manner as in Synthesis Example 3 except that the monomer compounding ratio was changed as shown in Table 2. ..

Examples 1-6, Comparative Examples 1-3
Each component other than the component (E) shown in Table 3 has a compounding composition shown in Table 3 (the compounding amount in the table is a part by mass, and in the case of a solution (excluding an organic solvent) or a dispersion, it is a solid content equivalent amount. ), And after dissolving in methyl isobutyl ketone, the component (E) was blended according to the blending composition shown in Table 3 to obtain a varnish having a non-volatile content of 40% by mass. The details of each component shown in Table 3 are as follows.

[(A) Phenolic resin]
(A-1): Phenolic resin (A-1) obtained in Synthesis Example 1.
(A-2): Phenolic resin (A-2) obtained in Synthesis Example 2.

[(B) Thermosetting resin]
Epoxy resin: Tetrabromobisphenol A type epoxy resin (epoxy equivalent 400 g / mol)

[(C) Acrylic polymer]
(C-1) to (C-3): Acrylic polymers (C-1) to (C-3) obtained in Synthesis Examples 3 to 5.

[(D) Specific copolymer resin]
(D-1) "SMA (registered trademark) EF40" (styrene / maleic anhydride = 4, Mw = 11,000, manufactured by CRAY VALLEY)
(D-2) "SMA (registered trademark) 3000" (styrene / maleic anhydride = 2, Mw = 9,500, manufactured by CRAY VALLEY)
(D-3) "SMA (registered trademark) EF80" (styrene / maleic anhydride = 8, Mw = 14,400, manufactured by CRAY VALLEY)
(D-4) Ingredient: SMA (registered trademark) 1000 "(styrene / maleic anhydride = 1, Mw = 5,000, manufactured by CRAY VALLEY)

[(E) Curing accelerator]
・ 2-Phenylimidazole

[(F) Filler]
-Silica: Fused silica treated with an aminosilane-based coupling agent (average particle size: 1.9 μm, specific surface area of 5.8 m ² / g)

Using the varnishes produced in each example, prepregs, copper foils with resin, and copper-clad laminates were produced by the following methods, and each evaluation was performed by the methods described below.

[Making prepreg]
The varnish produced in each example was impregnated with a glass cloth 1037 (manufactured by Asahi Schebel Co., Ltd., trade name) having a thickness of 0.028 mm, and then heated at 140 ° C. for 10 minutes to dry to obtain a prepreg.

[Making copper foil with resin]
The varnish produced in each example was applied to an electrolytic copper foil having a thickness of 35 μm by a coating machine and dried with hot air at 140 ° C. for about 6 minutes to prepare a copper foil with a resin having a coating thickness of 50 μm.

[Copper-clad laminate]
Electrolytic copper foils having a thickness of 35 μm were laminated on both sides of the four prepregs so that the adhesive surfaces were aligned with the prepregs, and a double-sided copper-clad laminate was prepared under vacuum pressing conditions of 4 MPa at 200 ° C. for 60 minutes.
Further, the copper foils with resin were laminated so that the resin surfaces faced each other, and a double-sided copper-clad laminate was prepared under vacuum pressing conditions of 4 MPa at 200 ° C. for 80 minutes.

(1) Confirmation of phase separation structure To confirm the phase separation structure, after smoothing the cross section of the resin insulating layer of the double-sided copper-clad laminate prepared from the copper foil with resin with a microtome, etching with a persulfate solution. The obtained sample was subjected to SEM observation (device name: SU-3500, manufactured by Hitachi High-Technologies Corporation, acceleration voltage 10 KV). In the SEM observation, the phase separation structure was confirmed at 3,000 times as "presence", and the phase separation structure was not confirmed as phase separation "absence". The results are shown in Table 3.

(2) Storage elastic modulus The storage elastic modulus was evaluated by cutting a laminated plate obtained by etching the entire surface of a copper foil of a double-sided copper-clad laminate prepared from a copper foil with resin into a width of 5 mm and a length of 30 mm. The storage elastic modulus was measured using a dynamic viscoelasticity measuring device (manufactured by UBM Co., Ltd.). It was judged that if the storage elastic modulus at 25 ° C. is 4.0 GPa or less, the elasticity is sufficiently low, the stress relaxation effect can be exhibited, and the occurrence of cracks in the printed wiring board can be suppressed. The results are shown in Table 3.

(3) Heat resistance A double-sided copper-clad laminate prepared from a prepreg was cut into a 50 mm square to obtain a test piece. The test piece was floated in a solder bath at 260 ° C., and the time elapsed from that point to the time when swelling of the test piece was visually recognized was measured and used as an index of heat resistance. The elapsed time was measured up to 1,800 seconds, and when 1,800 seconds or more passed (indicated as ">1,800" in Table 3), it was judged that the heat resistance was sufficient. The results are shown in Table 3.

(4) Tensile elongation rate (25 ° C and 125 ° C)
The laminated plate obtained by etching the entire surface of the copper foil of the double-sided copper-clad laminate made from the copper foil with resin is cut into a width of 10 mm and a length of 100 mm, and is installed in a constant temperature bath (manufactured by Shimadzu Corporation). The tensile elongation at 25 ° C. and 125 ° C. was measured using. When the tensile elongation at 25 ° C. was 2.5% or more and the tensile elongation at 125 ° C. was 6.0% or more, it was judged that the elongation was high and the stress relaxation effect could be exhibited. The results are shown in Table 3.

(5) Copper foil peeling strength (25 ° C and 125 ° C)
The copper foil of the double-sided copper-clad laminate prepared from the above-mentioned four prepregs was partially etched to form a copper foil line having a width of 3 mm. Next, using a constant temperature bath installation type peeling tester (manufactured by Shimadzu Corporation), set the temperature in an environment of 25 ° C or 125 ° C, and set the copper foil line at 50 mm / min in the 90 ° direction with respect to the adhesive surface. The load when peeled off at the speed of was measured and used as an index of adhesiveness with the metal foil. If the copper foil peeling strength at 25 ° C. is 0.80 kN / m or more and the copper foil peeling strength at 125 ° C. is 0.55 kN / m or more, the adhesiveness with the metal foil is sufficient. It was judged. The results are shown in Table 3.

(6) Glass transition temperature (Tg)
The double-sided copper-clad laminate prepared in each example was immersed in a copper etching solution "ammonium persulfate (APS)" (manufactured by ADEKA Co., Ltd.) to prepare a 5 mm square evaluation substrate from which the copper foil was removed, and the TMA test apparatus " Using "Q400EM" (manufactured by TA Instruments), a thermal expansion curve in the plane direction (Z direction) of the evaluation substrate at -50 to 260 ° C. was obtained, and the change point of the expansion amount was defined as the glass transition temperature. The results are shown in Table 3.

As is clear from Table 3, Examples 1 to 6 using the thermosetting resin composition of the present embodiment have high Tg, sufficient heat resistance and low elastic modulus, and are in a normal temperature environment. In addition, the tensile modulus was high in a high temperature environment, and the adhesive strength with the metal foil was high. It is presumed that the component (D) reacts with the component (A) to generate a carboxylic acid group, so that the adhesive strength with the metal foil is improved. The exact mechanism by which high Tg was obtained is unknown, but the reaction of component (D) with component (B) to form an ester group resulted in the achievement of high Tg.
On the other hand, in Comparative Examples 1 to 3 which do not contain the component (D), low elasticity is exhibited, but Tg is lowered, and the tensile elongation rate in a high temperature environment may be lowered, and the tensile elongation rate in a high temperature environment may be lowered. The adhesive strength with the metal foil in the environment became low.

Claims (21)

(A) Phenolic resin,
(B) Thermosetting resin,
A copolymer resin having (C) an acrylic polymer and (D) a structural unit derived from an aromatic vinyl compound and a structural unit derived from maleic anhydride.
Is a thermosetting resin composition containing
A thermosetting resin composition, wherein the component (A) contains (A1) a phenolic resin having a chain aliphatic hydrocarbon group having 10 to 25 carbon atoms. The component (A1) contains a structural unit derived from a phenolic compound represented by the following general formula (1) and a structural unit derived from a phenolic compound represented by the following general formula (2). The thermosetting resin composition according to claim 1.

(In the formula, R ¹ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms which may have a substituent, and an aromatic having 5 to 15 ring-forming atoms which may have a substituent. A group hydrocarbon group or a combination of the aliphatic hydrocarbon group and the aromatic hydrocarbon group is shown. R ² represents a chain aliphatic hydrocarbon group having 10 to 25 carbon atoms, and X is hydrogen. Indicates an atom, hydroxy group or hydroxymethyl group.) The thermosetting resin composition according to claim 1 or 2, wherein the content of the component (A1) is 0.1 to 40 parts by mass with respect to 100 parts by mass of the total amount of the resin component of the thermosetting resin composition. Stuff. The component (B) is an epoxy resin, a cyanate resin, a bismaleimide-based compound, an addition polymer of a bismaleimide-based compound and a diamine compound, an isocyanate resin, a triallyl isocyanurate resin, a triallyl cyanurate resin, and a vinyl group-containing polyolefin. The thermocurable resin composition according to any one of claims 1 to 3, which is one or more selected from the group consisting of resins. The component (C) is a structural unit (c1) represented by the following general formula (c1), a structural unit (c2) represented by the following general formula (c2), and a structure represented by the following general formula (c3). The thermosetting resin composition according to any one of claims 1 to 4, which comprises a unit (c3) and a structural unit (c4) represented by the following general formula (c4).

(R ^c1 represents a hydrogen atom or a methyl group, and R ^c2 represents a hydrocarbon group having 1 to 3 carbon atoms.)

(R ^c3 represents a hydrogen atom or a methyl group, and R ^c4 represents a hydrocarbon group having 5 to 22 carbon atoms including an alicyclic hydrocarbon group.)

(R ^c5 represents a hydrogen atom or a methyl group, and R ^c6 represents a chain hydrocarbon group having 4 to 10 carbon atoms.)

(R ^c7 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Z represents a hydroxy group or consists of a carboxy group, a hydroxy group, an acid anhydride group, an amino group, an amide group and an epoxy group. Indicates a substituent containing one or more functional groups selected from the group.) The content of the structural unit (c1) in the component (C) is 1 to 60% by mass, the content of the structural unit (c2) is 1 to 20% by mass, and the content of the structural unit (c3) is 5. The thermocurable resin composition according to claim 5, wherein the content is ~ 90% by mass and the content of the structural unit (c4) is 1 to 20% by mass. Further, claims 1 to 6, further comprising (A2) a phenolic resin having an aliphatic hydrocarbon group having 10 to 25 carbon atoms, which is a combination of a chain aliphatic hydrocarbon group and a cyclic aliphatic hydrocarbon group. The heat-curable resin composition according to any one of the items. The thermosetting according to claim 7, wherein the content ratio of the component (A1) to the component (A2) [component (A1) / component (A2)] is 0.1 to 1 on a mass basis. Resin composition. Claims 1 to 8, wherein the component (D) is a copolymer resin having a structural unit represented by the following general formula (Di) and a structural unit represented by the following formula (D-ii). The thermosetting resin composition according to any one of the items.

(In the formula, ^RD1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and ^RD2 is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, and 6 to 20 carbon atoms. It is an aryl group, a hydroxyl group or a (meth) acryloyl group. X is an integer of 0 to 3. However, when x is 2 or 3, a plurality of R ^D2s may be the same or different. May be.) The thermosetting resin composition according to claim 9, wherein ^RD1 is a hydrogen atom and x is 0 in the general formula (Di). In the component (D), the content ratio of the structural unit derived from the aromatic vinyl compound and the structural unit derived from maleic anhydride [structural unit derived from the aromatic vinyl compound / structural unit derived from maleic anhydride] (mol). The thermosetting resin composition according to any one of claims 1 to 10, wherein the ratio) is 1-9. In the component (D), the content ratio of the structural unit derived from the aromatic vinyl compound and the structural unit derived from maleic anhydride [structural unit derived from the aromatic vinyl compound / structural unit derived from maleic anhydride] (mol). The thermocurable resin composition according to any one of claims 1 to 11, wherein the ratio) is 3 to 7. The thermosetting resin composition according to any one of claims 1 to 12, wherein the weight average molecular weight of the component (D) is 4,500 to 18,000. The thermosetting resin composition according to any one of claims 1 to 13, wherein the weight average molecular weight of the component (D) is 9,000 to 13,000. The thermosetting resin composition according to any one of claims 1 to 14, wherein the cured product does not have a phase-separated structure. The thermosetting resin composition according to any one of claims 1 to 14, wherein the cured product has a phase-separated structure. A prepreg containing the thermosetting resin composition according to any one of claims 1 to 16. A metal foil with a resin, which is formed by laminating the thermosetting resin composition according to any one of claims 1 to 16 and a metal foil. A laminate comprising the prepreg according to claim 17 or the metal foil with resin according to claim 18. A printed wiring board comprising the laminate according to claim 19. A semiconductor package comprising the printed wiring board according to claim 20.