Resin compositions, cured products, electronic circuit board materials, resin films, prepregs, and laminates

Abstract

To provide a resin composition which can obtain a cured product that has a low dielectric constant and a low dielectric loss tangent, and is excellent in compatibility and drilling workability.SOLUTION: A resin composition contains a component (I), a component (II) and a component (III). Component (I): a block copolymer containing a conjugated diene monomer unit and a vinyl aromatic monomer unit, having a random polymer block (A) including the conjugated diene monomer unit and the vinyl aromatic monomer unit, a polymer block (B) mainly containing a vinyl aromatic monomer unit and / or a polymer block (C) mainly containing a conjugated diene monomer unit, containing 30-85 mass% of the random polymer block (A) with respect to 100 mass% of the block copolymer, and having a tanδ peak of the block copolymer obtained by dynamic viscoelasticity measurement (1 Hz) of -30°C to 60°C. Component (II): a bismaleimide compound. Component (III): a cyanate compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to resin compositions, cured products, electronic circuit board materials, resin films, prepregs, and laminates. [Background technology]

[0002] In recent years, with the remarkable advancements in information network technology and the expansion of services utilizing information networks, electronic devices are required to have larger data capacities and faster processing speeds. To meet these demands, materials with low dielectric loss are required for various types of substrates, such as printed circuit boards and flexible substrates.

[0003] Conventionally, in order to obtain materials with low dielectric loss, resin cured products mainly composed of thermosetting resins such as epoxy resins, which have low dielectric constant and / or low dielectric loss tangent, and excellent mechanical properties such as strength and heat resistance, or thermoplastic resins such as polyphenylene ether resins, have been investigated and disclosed. However, conventionally disclosed materials still have room for improvement in terms of low dielectric constant and low dielectric loss tangent, and when used in printed circuit boards, they have the problem of limiting the amount of information that can be processed and the processing speed.

[0004] To address these issues, numerous resin compositions containing rubber components as modifiers, resin compositions primarily composed of the aforementioned rubber components, and cured products thereof have been proposed. For example, a technique is known in which a resin material containing a styrene-based elastomer is used as an insulating layer between multilayered wirings in a printed circuit board to achieve low dielectric constant and low dielectric loss tangent. Styrene-based elastomers are compounds that excel in low dielectric constant and low dielectric loss tangent, and are expected to be effective in increasing transmission speed and reducing transmission loss. Furthermore, a technique has been disclosed in which a laminate of prepregs using this styrene-based elastomer is applied to a printed circuit board to improve the performance and multilayering of the printed circuit board (see, for example, Patent Documents 1 to 3).

[0005] On the other hand, when drilling holes in the insulating layer of a multilayer printed wiring board, there is a problem that cracks occur in the insulating layer due to the impact and frictional heat generated, leading to a decrease in production efficiency and deterioration of the performance of the insulating layer. Also, resin residues (smear) are generated in the via holes due to frictional heat, and it is necessary to remove the smear in the roughening treatment process, which is known to cause a decrease in production efficiency (for example, see Patent Document 4). Particularly, in a resin composition containing a bismaleimide compound, cracks are likely to occur during processing, so it is necessary to add a resin as a softening agent. For example, Patent Document 5 discloses a resin composition containing a bismaleimide compound and a styrene-based elastomer, and it is also described that a compatibilizer is blended to promote compatibilization between the bismaleimide compound with a high SP value and the styrene-based elastomer.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, as described in Patent Document 5, when a compatibilizer is added to the resin composition, there are problems such as affecting the dielectric constant of the resin composition and the compatibilizer may precipitate in the process of processing into prepregs or the like. Therefore, there is a need for a resin composition in which the elastomer itself exhibits good compatibility with bismaleimide without the addition of a compatibilizer.

[0008] Therefore, the present invention aims to provide a resin composition that yields a cured product with low dielectric constant and low dielectric loss tangent, good compatibility, and excellent drilling processability. [Means for solving the problem]

[0009] As a result of diligent research to solve the problems of the prior art described above, the present inventors have found that the problems of the prior art described above can be solved by a resin composition comprising a block copolymer having a predetermined structure, comprising a conjugated diene monomer unit and a vinyl aromatic monomer unit, and having a structure with a tanδ peak in a predetermined temperature range, a bismaleimide compound, and a cyanate ester compound, and have completed the present invention. In other words, the present invention is as follows:

[0010] [1] A resin composition comprising the components (I), (II), and (III) shown below. Component (I): A block copolymer comprising conjugated diene monomer units and vinyl aromatic monomer units, A random polymer block (A) comprising the conjugated diene monomer unit and the vinyl aromatic monomer unit, The polymer comprises a polymer block (B) mainly composed of vinyl aromatic monomer units, and / or a polymer block (C) mainly composed of conjugated diene monomer units. The random polymer block (A) is contained in an amount of 30 to 85% by mass relative to 100% by mass of the block copolymer. A block copolymer in which the tanδ peak obtained by dynamic viscoelasticity measurement (1 Hz) is in the range of -30°C to 60°C. Component (II): Bismaleimide compound. Component (III): Cyanate ester compound. [2] The resin composition according to [1], wherein the content of polymer blocks (B) mainly composed of vinyl aromatic monomer units is 3% to 55% by mass of 100% by mass of the block copolymer of component (I). [3] The resin composition according to [1] or [2], wherein the content of vinyl aromatic monomer units in 100% by mass of the block copolymer of component (I) is 30% by mass to 90% by mass. [4] The resin composition according to any one of [1] to [3], wherein the amount of vinyl bond is 15 to 90 ml with respect to a total of 100 ml of conjugated diene monomer units contained in the block copolymer of component (I). [5] The resin composition according to any one of [1] to [4], wherein the hydrogenation rate of the double bonds of the conjugated diene monomer units contained in the block copolymer of component (I) is 15 ml or more. [6] The resin composition according to any one of [1] to [5], wherein the weight-average molecular weight (Mw) of the block copolymer of component (I) is 30,000 to 500,000. [7] The resin composition according to any one of [1] to [6], wherein the content of component (I) is 5 to 50 parts by mass per 100 parts by mass of resin solids in the resin composition. [8] A cured product of the resin composition described in any one of the above [1] to [7]. [9] An electronic circuit board material comprising the cured product described in [8] above.

[10] A resin film containing the cured product described in [8] above.

[11] A prepreg that is a composite of a substrate and the resin composition and / or the cured product described in any one of [1] to [7] above.

[12] The prepreg according to

[11] , wherein the substrate is glass cloth.

[13] A laminate comprising a resin film as described in

[10] above, a cured product selected from the group consisting of the resin film as described in

[11] or the prepreg as described in

[12] above, and a metal foil. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a resin composition that yields a cured product with low dielectric constant and low dielectric loss tangent, as well as excellent compatibility and drilling processability. [Modes for carrying out the invention]

[0012] The embodiments for carrying out the present invention (hereinafter referred to as "this embodiment") will be described in detail below. The following embodiments are illustrative examples for explaining the present invention and are not intended to limit the present invention to the following content. The present invention can be implemented in various modified forms within the scope of its gist.

[0013] [Resin composition] The resin composition of this embodiment contains the following components (I), (II), and (III). Component (I): A block copolymer comprising conjugated diene monomer units and vinyl aromatic monomer units, comprising a random polymer block (A) comprising conjugated diene monomer units and vinyl aromatic monomer units, a polymer block (B) mainly composed of vinyl aromatic monomer units, and / or a polymer block (C) mainly composed of conjugated diene monomer units. The content of the random polymer block (A) is 30 to 85% by mass relative to 100% by mass of the block copolymer, and the tanδ peak of the block copolymer obtained by dynamic viscoelasticity measurement (1 Hz) is in the range of -30°C to 60°C. Component (II): Bismaleimide compound. Component (III): Cyanate ester compound. By having the above configuration, a cured product with a low dielectric constant and low dielectric loss tangent, as well as excellent compatibility and drillability, can be obtained.

[0014] (Component (I)) The block copolymer of component (I) constituting the resin composition of this embodiment (hereinafter sometimes referred to as block copolymer (I) or component (I)) is a block copolymer containing conjugated diene monomer units and vinyl aromatic monomer units, and may be a hydrogenated product, from the viewpoint of low dielectric constant and low dielectric loss tangent of the cured product. The block copolymer (I) includes a random polymer block (A) (hereinafter sometimes referred to as random polymer block (A) or polymer block (A)) containing conjugated diene monomer units and vinyl aromatic monomer units, and further includes a polymer block (B) (hereinafter sometimes referred to as polymer block (B)) mainly composed of vinyl aromatic monomer units and / or a polymer block (C) (hereinafter sometimes referred to as polymer block (C)) mainly composed of conjugated diene monomer units.

[0015] In this specification, a conjugated diene monomer unit refers to a constituent unit derived from a conjugated diene compound in a polymer block or block copolymer produced by the polymerization of a conjugated diene compound. Conjugated diene compounds are diolefins that have one pair of conjugated double bonds. Examples of conjugated diene compounds include, but are not limited to, 1,3-butadiene, 2-methyl-1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferred. These may be used individually or in combination of two or more types.

[0016] In this specification, a vinyl aromatic monomer unit refers to a constituent unit derived from a vinyl aromatic compound in a polymer block or block copolymer produced by the polymerization of a vinyl aromatic compound. Examples of vinyl aromatic compounds include, but are not limited to, styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene. These may be used individually or in combination of two or more types.

[0017] The random polymer block (A) constituting the block copolymer (I) used in the resin composition of this embodiment contains vinyl aromatic monomer units and conjugated diene monomer units, and may be hydrogenated. The random polymer block (A) preferably has vinyl aromatic monomer units and conjugated diene monomer units as its main constituent units. Here, "main constituent units" means that the sum of vinyl aromatic monomer units and conjugated diene monomer units is 80% by mass or more of the total mass of the random polymer block (A). The content of vinyl aromatic monomer units and conjugated diene monomer units in the random polymer block (A) is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass, based on the total mass of the random polymer block (A).

[0018] In the random polymer block (A), the vinyl aromatic monomer units may be uniformly distributed or tapered. Furthermore, the random polymer block (A) may contain multiple portions where the vinyl aromatic monomer units are uniformly distributed or multiple portions where they are tapered.

[0019] If multiple random polymer blocks (A), polymer blocks (B), and polymer blocks (C) are present in a block copolymer (I), their molecular weights, compositions, and other structural characteristics may be identical or different.

[0020] From the standpoint of solubility parameters, vinyl aromatic compounds tend to have higher compatibility with highly polar cured resins than conjugated diene compounds. However, in random polymer blocks (A), the copolymerization of conjugated diene compounds reduces steric hindrance compared to polymer blocks consisting solely of vinyl aromatic compounds. As a result, the presence of random polymer blocks (A), which are random blocks of vinyl aromatic compounds and conjugated diene compounds, in the block copolymer (I) further improves compatibility with highly polar cured resins, and the strength of the resin composition and / or cured product of this embodiment tends to improve. Furthermore, the improved compatibility suppresses the decrease in polymer mobility and / or polarization caused by an external electric field in the resin composition and / or cured product of this embodiment, as described later, and improves the dielectric loss tangent and / or dielectric constant of the resin composition and / or cured product. Since both the loss due to polarization of the polymer by an external electric field (dielectric constant) and the energy loss due to heat generated by motion (dielectric loss tangent) can be suppressed by ensuring sufficient compatibility and reactivity with the crosslinkable resin, it is believed that having random polymer blocks (A) in the block copolymer (I) leads to increased strength of the resin composition and / or cured product of this embodiment, as well as low dielectric loss tangent and low dielectric constant.

[0021] The bismaleimide compound (II) and the cyanate ester compound (III) constituting the resin composition of this embodiment are highly polar resins. From the viewpoint of compatibility with these components (II) and (III), the random polymer block (A) is contained in an amount of 30 to 85% by mass per 100% by mass of the block copolymer (I). By having a random polymer block (A) content of 30% by mass or more in the block copolymer (I), the generation of air bubbles in the film when the resin composition of this embodiment is coated onto a film can be suppressed. Furthermore, by having a random polymer block (A) content of 85% by mass or less in the block copolymer (I), gel formation and phase separation of the varnish solution of the resin composition of this embodiment tend to be suppressed. Furthermore, from the viewpoint of improving the flexural strength of the cured resin composition of this embodiment, the content of random polymer blocks (A) in the block copolymer (I) is preferably 35 to 70% by mass, and more preferably 40 to 60% by mass. The content of random polymer blocks (A) in the block copolymer (I) is obtained by taking out the polymer at each step of the synthesis described in the examples below, measuring its molecular weight by gel permeation chromatography (GPC), and then calculating the content. The content of random polymer blocks (A) in the block copolymer (I) can be controlled within the above numerical range by adjusting the timing and amount of monomer addition during the polymerization process when producing the block copolymer (I).

[0022] The block copolymer (I) comprises, in addition to the random polymer block (A) described above, a polymer block (B) mainly composed of vinyl aromatic monomer units and / or a polymer block (C) mainly composed of conjugated diene monomer units. The polymer block (B) mainly composed of vinyl aromatic monomer units has vinyl aromatic compound units as its main component, and the content of vinyl aromatic monomer units is greater than 95% by mass when the total polymer block (B) is considered as 100% by mass, preferably 96% by mass or more, more preferably 97% by mass or more, and even more preferably 100% by mass.

[0023] A polymer block (C) mainly composed of conjugated diene monomer units has conjugated diene monomer units as its main component, and the content of conjugated diene monomer units is greater than 95% by mass, preferably 96% by mass or more, more preferably 97% by mass or more, and even more preferably 100% by mass, when the total polymer block (C) is considered as 100% by mass.

[0024] The structure of the block copolymer of component (I) is not limited to the following, but examples include structures represented by the following general formula. (BA) n , B-(AB) n , A-(BA)n , [(A - B) n m -X, [(B - A) n m -X, [(A - B) n -A] m -X, [(B - A) n -B] m -X, (A - B) n -X - (B) p , (C - A) n , C - (A - C) n , A - (C - A) n , [(C - A) n m -X, [(A - C) n -A] m -X, [(C - A) n -C] m -X, C - (A - B) n , C - (B - A) n , C - (B - A - B) n , C - (A - B - A) n , B - C - (A - B) n , BC - (B - A) n , B - C - (A - B) n -C, [(B - A - C) n m -X, [B - (AC) n m -X, [(B - A) n -C] m -X, [(B - A - B) n -C] m -X, [(A - B - A) n -C] m -X, [(C - A - B) n m -X, [C - (A - B) n m -X, [C - (B - A - B) n m -X, [C - (A - B - A) n m -X Here, in the general formula, A is a random polymer block (A), B is a polymer block (B) mainly composed of vinyl aromatic monomer units, and C is a block (C) mainly composed of conjugated diene monomer units. ​​​​​​​​​The boundaries of each block do not necessarily need to be clearly distinguishable. m is an integer greater than or equal to 2, preferably an integer between 2 and 10, and n and p are integers greater than or equal to 1, preferably an integer between 1 and 10. X represents a coupling agent residue or a polyfunctional initiator residue. Furthermore, the structure of the polymer chains bonded to X may be identical or different.

[0025] The structure of block copolymer (I) is B-(AB) from the viewpoint of compatibility with components (II) and (III). n , (BA) n [(BA) n ] m -X, or C-(BAB) n That is particularly preferable.

[0026] <tanδピーク> From the viewpoint of improving the drillability of the cured resin composition of this embodiment, the block copolymer (I) has a tanδ peak obtained by dynamic viscoelasticity measurement (1 Hz) in the range of -30°C to 60°C. The fact that the tanδ peak is above -30°C suppresses the occurrence of smear when drilling holes in the cured resin composition of this embodiment. Furthermore, the fact that the tanδ peak is below 60°C tends to reduce the likelihood of crack formation during drilling. When the thickness of the cured product is increased, the tanδ peak temperature of the block copolymer (I) is preferably -25°C to 50°C, more preferably -20°C to 40°C. The tanδ peak can be measured by the method described in the examples below. The tanδ peak temperature can be controlled to the above numerical range by adjusting the content of vinyl aromatic monomer units in the random polymer block (A), the amount of vinyl bonds in the conjugated diene before hydrogenation, and the hydrogenation rate. The tanδ peak of block copolymer (I) tends to rise as the vinyl aromatic monomer units in random polymer block (A) increase, and tends to fall as they decrease. The tanδ peak temperature tends to increase as the vinyl bond amount before hydrogenation increases, and tends to decrease as it decreases. The tanδ peak temperature tends to decrease as the hydrogenation rate increases, and tends to increase as it decreases.

[0027] For example, in order to keep the tanδ peak temperature within -30°C to 60°C, a polymer with a "B-A-B" structure may be designed to satisfy the following formula (1). 0.3 < x + y + z < 2.5 and 0.002 < xyz < 0.33 Formula (1) In the above formula (1), x is the mass fraction of vinyl aromatic monomer units contained in the random polymer block (A), y is the molar fraction of the vinyl bond amount before hydrogenation contained in the block copolymer (I), and z is the percentage of the hydrogen addition amount.

[0028] <Mass ratio of vinyl aromatic monomer unit / conjugated diene monomer unit> The mass ratio of vinyl aromatic monomer units and conjugated diene monomer units contained in the random polymer block (A) particularly affects the tanδ peak temperature. By setting the mass ratio of vinyl aromatic monomer unit / conjugated diene monomer unit to 5 / 95 to 80 / 20, the tanδ peak temperature tends to be controlled within -30°C to 60°C. From the viewpoints of suppressing resin flow and cracks during drilling of the cured product of the resin composition of this embodiment and compatibility with the components (II) and (III), the mass ratio of vinyl aromatic monomer unit / conjugated diene monomer unit is preferably 5 / 95 to 80 / 20, more preferably 15 / 85 to 70 / 30, and still more preferably 20 / 80 to 60 / 40. Also, the content of vinyl aromatic monomer units in the random polymer block (A) can be measured by the method described in the examples.

[0029] <Content of polymer block (B)> The content of polymer blocks (B) mainly composed of vinyl aromatic monomer units in the block copolymer (I) is preferably 3 to 55% by mass, more preferably 3 to 50% by mass, even more preferably 5 to 48% by mass, even more preferably 7 to 45% by mass, and still more preferably 10 to 40% by mass, from the viewpoint of reducing the coefficient of thermal expansion of the cured resin composition of this embodiment. The content of polymer blocks (B) in block copolymer (I) can be measured by the method described in the examples below. The content of polymer blocks (B) in block copolymer (I) can be controlled within the above numerical range by adjusting the timing and amount of vinyl aromatic compound added during the polymerization step in the manufacturing process of block copolymer (I).

[0030] <Content of vinyl aromatic monomer units> From the viewpoint of reducing the thermal expansion coefficient of the cured resin composition of this embodiment, the content of vinyl aromatic monomer units in the block copolymer (I) is preferably 30% to 90% by mass, more preferably 33% to 88% by mass, and even more preferably 35% to 85% by mass, of 100% by mass of the block copolymer (I). The content of vinyl aromatic monomer units in the block copolymer (I) can be measured by the method described in the examples. The content of vinyl aromatic monomer units in block copolymer (I) can be controlled within the above numerical range by adjusting the timing and amount of vinyl aromatic compound added during the manufacturing process of block copolymer (I).

[0031] <Amount of vinyl binding> In the block copolymer (I), the amount of vinyl bonded conjugated diene monomer units before hydrogenation is preferably in the range of 15 to 90 moles, more preferably in the range of 17 to 87 moles, and even more preferably in the range of 20 to 85 moles, based on 100 moles of the total amount of conjugated diene monomer units, from the viewpoint of smearability and the flexural strength of the cured resin composition. The vinyl bond content of conjugated diene monomer units before hydrogenation refers to the percentage (%) of conjugated diene monomer units incorporated in block copolymer (I) via 1,2-bonds and 3,4-bonds, where 1,2-bonds and 3,4-bonds are present. The amount of vinyl bonding can be controlled within the above numerical range by using Lewis bases, such as compounds like ethers and amines, as vinylizing agents, and by adjusting the amount used and the polymerization temperature. This can be measured by nuclear magnetic resonance spectroscopy (NMR) or the like. Specifically, it can be measured by the method described in the examples below.

[0032] <Weight average molecular weight> The block copolymer (I) preferably has a weight-average molecular weight (Mw) of 30,000 to 500,000, more preferably 50,000 to 450,000, and even more preferably 70,000 to 400,000, from the viewpoint of the flexural strength of the cured resin composition of this embodiment, compatibility with components (II) and (III), and solvent solubility for use in the varnish of the resin composition of this embodiment. The weight-average molecular weight can be measured by the method described in the examples below. Note that "solvent solubility" refers to the solvent used when manufacturing the varnish described in the examples below. The weight-average molecular weight of block copolymer (I) can be controlled to the above numerical range by adjusting the polymerization conditions in the manufacturing process of block copolymer (I), specifically the amount of monomer added, polymerization temperature, polymerization pressure, and polymerization time.

[0033] <Hydrogenation rate> From the viewpoint of the thermal stability of the cured product of the resin composition of this embodiment, the hydrogenation rate of the block copolymer (I) is preferably 15 ml or more, more preferably 20 to 99 ml, and even more preferably 25 to 98 ml. The hydrogenation rate can be controlled within the above numerical range by adjusting the amount of catalyst and hydrogen feed during hydrogenation. The hydrogenation rate can be controlled, for example, by adjusting the amount of catalyst, hydrogen feed, pressure, and temperature during hydrogenation.

[0034] <Content of block copolymer (I)> From the viewpoint of the flexural strength of the cured product of the resin composition of this embodiment, the content of block copolymer (I) in the resin composition of this embodiment is preferably 5 parts by mass or more and 50 parts by mass or less per 100 parts by mass of resin solids in the resin composition of this embodiment. Furthermore, from the viewpoint of improving the flexural strength of the resin composition, the lower limit of the content of block copolymer (I) is more preferably 6 parts by mass or more, and even more preferably 7 parts by mass or more. Furthermore, from the viewpoint of suppressing the decrease in the glass transition temperature of the cured product of the resin composition of this embodiment, the upper limit of the content of block copolymer (I) is more preferably 50 parts by mass or less, and even more preferably 35 parts by mass or less. Here, the resin solids of a resin composition refer to the components remaining after removing the filler and solvent from the resin composition. 100 parts by mass of resin solids means that the total amount of components remaining after removing the filler and solvent from the resin composition is 100 parts by mass.

[0035] (Component (II): Bismaleimide compound) The resin composition of this embodiment contains component (II): bismaleimide compound (hereinafter sometimes referred to as bismaleimide compound (II) or component (II)). The bismaleimide compound (II) is not particularly limited as long as it is a compound having one or more maleimide groups in one molecule. Using the bismaleimide compound (II) tends to improve heat resistance and heat resistance when absorbing moisture. The bismaleimide compound (II) is not limited to the following, but examples include N-phenylmaleimide, N-hydroxyphenylmaleimide, bis(4-maleimoidphenyl)methane, 2,2-bis{4-(4-maleimoidphenoxy)-phenyl}propane, 4,4'-diphenylmethanebismaleimide, bis(3,5-dimethyl-4-maleimoidphenyl)methane, bis(3,5-diethyl-4-maleimoidphenyl)methane, phenylmethanemaleimide, o-phenylenebismaleimide, m-phenylenebismaleimide, p-phenylenebismaleimide, o-phenylenebiscitraconimide, m-phenylenebiscitraconimide, p-phenylenebiscitraconimide, 2,2-bis(4-(4-maleimoidphenoxy)-phenyl)propane, 3,3'-dimethyl-5,5'-diethyl-5 Examples include 4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, 4,4'-diphenylmethanebiscitraconimide, 2,2-bis[4-(4-citraconimidophenoxy)phenyl]propane, bis(3,5-dimethyl-4-citraconimidophenyl)methane, bis(3-ethyl-5-methyl-4-citraconimidophenyl)methane, bis(3,5-diethyl-4-citraconimidophenyl)methane, and prepolymers of maleimide compounds and amine compounds.

[0036] The bismaleimide compound (II) used in the resin composition of this embodiment may be a commercially available product. Examples of commercially available bismaleimide compounds include "BMI-2300" manufactured by Yamato Chemical Industries, Ltd., "MIR-3000" manufactured by Nippon Kayaku Co., Ltd., and "BMI-70" manufactured by Yamato Chemical Industries, Ltd., which can be suitably used. Furthermore, the content of bismaleimide compound (II) in the resin composition of this embodiment is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 12 parts by mass or more, per 100 parts by mass of the resin solids content of the resin composition. The upper limit of the above content is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, even more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less. Bismaleimide compound (II) may be used alone, or two or more may be used in appropriate mixtures. When two or more are used, it is preferable that the total amount be within the above range.

[0037] (Component (III): Cyanate ester compound) The resin composition of this embodiment contains a cyanate ester compound (hereinafter sometimes referred to as cyanate ester compound (III) or component (III)) as component (III). The cyanate ester compound (III) is not particularly limited as long as it is a resin having an aromatic moiety in its molecule to which at least one cyanate group (cyanate ester group) is substituted. The cyanate ester compound (III) is more preferably an amorphous compound from the viewpoint of chemical resistance.

[0038] Cyanate ester compounds (III) are not limited to the following, but include, for example, phenol novolac type cyanate ester compounds, biphenyl aralkyl type cyanate ester compounds, bisphenol A type cyanate ester compounds, diallylbisphenol A type cyanate ester compounds, bisphenol E type cyanate ester compounds, bisphenol F type cyanate ester compounds, bisphenol M type cyanate ester compounds, naphthol aralkyl type cyanate ester compounds, naphthylene ether type cyanate ester compounds, and xylene. Resin-type cyanate ester compounds, trisphenolmethane-type cyanate and adamantane skeleton-type cyanate ester compounds, cyanatobenzene, 1-cyanato-2-methylbenzene, 1-cyanato-3-methylbenzene, or 1-cyanato-4-methylbenzene, 1-cyanato-2-methoxybenzene, 1-cyanato-3-methoxybenzene, or 1-cyanato-4-methoxybenzene, 1-cyanato-2,3-dimethylbenzene, 1-cyanato-2,4-dimethylbenzene, 1-cyanato-2,5-dimethylbenzene, 1-cyanato-2 ,6-dimethylbenzene, 1-cyanato-3,4-dimethylbenzene or 1-cyanato-3,5-dimethylbenzene, cyanatoethylbenzene, cyanatobutylbenzene, cyanatooctylbenzene, cyanatononylbenzene, 2-(4-cyanatophenyl)-2-phenylpropane (cyanate of 4-α-cumylphenol), 1-cyanato-4-cyclohexylbenzene, 1-cyanato-4-vinylbenzene, 1-cyanato-2-chlorobenzene or 1-cyanato-3-chlorobenzene, 1-cyanato-2,6-dichlorobenzene Examples include 1-cyanato-2-methyl-3-chlorobenzene, cyanatonitrobenzene, 1-cyanato-4-nitro-2-ethylbenzene, 1-cyanato-2-methoxy-4-allylbenzene (cyanate of eugenol), methyl (4-cyanatophenyl) sulfide, 1-cyanato-3-trifluoromethylbenzene, 4-cyanatobiphenyl, 1-cyanato-2- or 1-cyanato-4-acetylbenzene, 4-cyanatobenzaldehyde, 4-cyanatobenzoate methyl ester, and 4-cyanatobenzoate phenyl ester.

[0039] Furthermore, examples of cyanate ester compounds (III) include 1-cyanato-4-acetaminobenzene, 4-cyanatobenzophenone, 1-cyanato-2,6-di-tert-butylbenzene, 1,2-dicyanatobenzene, 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,4-dicyanato-2-tert-butylbenzene, 1,4-dicyanato-2,4-dimethylbenzene, 1,4-dicyanato-2,3,4-dimethylbenzene, 1,3-dicyanato-2,4,6-trimethylbenzene, 1,3-dicyanato-5-methylbenzene, and 1-cyanato-2,4-methylbenzene. Examples include sodium naphthalene or 2-cyanatonaphthalene, 1-cyanato-4-methoxynaphthalene, 2-cyanato-6-methylnaphthalene, 2-cyanato-7-methoxynaphthalene, 2,2'-dicyanato-1,1'-binaphthyl, 1,3-,1,4-,1,5-,1,6-,1,7-,2,3-,2,6- or 2,7-dicyanatosinaphthalene, 2,2'-dicyanatobiphenyl or 4,4'-dicyanatobiphenyl, 4,4'-dicyanatooctafluorobiphenyl, 2,4'-dicyanatodiphenylmethane or 4,4'-dicyanatodiphenylmethane, etc.

[0040] Furthermore, examples of cyanate ester compounds (III) include bis(4-cyanato-3,5-dimethylphenyl)methane, 1,1-bis(4-cyanatophenyl)ethane, 1,1-bis(4-cyanatophenyl)propane, 2,2-bis(4-cyanatophenyl)propane, 2,2-bis(3-allyl-4-cyanatophenyl)propane, 2,2-bis(4-cyanato-3-methylphenyl)propane, 2,2-bis(2-cyanato-5-biphenylyl)propane, 2,2-bis(4-cyanatophenyl)hexafluoropropane, 2,2-bis(4-cyanato-3,5-dimethylphenyl)propane, 1,1-bis(4-cyanatophenyl)butane, 1, Examples include 1-bis(4-cyanatophenyl)isobutane, 1,1-bis(4-cyanatophenyl)pentane, 1,1-bis(4-cyanatophenyl)-3-methylbutane, 1,1-bis(4-cyanatophenyl)-2-methylbutane, 1,1-bis(4-cyanatophenyl)-2,2-dimethylpropane, 2,2-bis(4-cyanatophenyl)butane, 2,2-bis(4-cyanatophenyl)pentane, 2,2-bis(4-cyanatophenyl)hexane, 2,2-bis(4-cyanatophenyl)-3-methylbutane, 2,2-bis(4-cyanatophenyl)-4-methylpentane, and 2,2-bis(4-cyanatophenyl)-3,3-dimethylbutane.

[0041] Examples of cyanate ester compounds (III) include 3,3-bis(4-cyanatophenyl)hexane, 3,3-bis(4-cyanatophenyl)heptane, 3,3-bis(4-cyanatophenyl)octane, 3,3-bis(4-cyanatophenyl)-2-methylpentane, 3,3-bis(4-cyanatophenyl)-2-methylhexane, and 3,3-bis(4-cyanatophenyl)-2,2-dimethylpentane. , 4,4-bis(4-cyanatophenyl)-3-methylheptane, 3,3-bis(4-cyanatophenyl)-2-methylheptane, 3,3-bis(4-cyanatophenyl)-2,2-dimethylhexane, 3,3-bis(4-cyanatophenyl)-2,4-dimethylhexane, 3,3-bis(4-cyanatophenyl)-2,2,4-trimethylpentane, 2,2-bis(4-cyanatophenyl)-1,1,1,3,3 Examples include ,3-hexafluoropropane, bis(4-cyanatophenyl)phenylmethane, 1,1-bis(4-cyanatophenyl)-1-phenylethane, bis(4-cyanatophenyl)biphenylmethane, 1,1-bis(4-cyanatophenyl)cyclopentane, 1,1-bis(4-cyanatophenyl)cyclohexane, 2,2-bis(4-cyanato-3-isopropylphenyl)propane, 1,1-bis(3-cyclohexyl-4-cyanatophenyl)cyclohexane, bis(4-cyanatophenyl)diphenylmethane, bis(4-cyanatophenyl)-2,2-dichloroethylene, 1,3-bis[2-(4-cyanatophenyl)-2-propyl]benzene, 1,4-bis[2-(4-cyanatophenyl)-2-propyl]benzene, and 1,1-bis(4-cyanatophenyl)-3,3,5-trimethylcyclohexane.

[0042] Furthermore, examples of cyanate ester compounds (III) include 4-[bis(4-cyanatophenyl)methyl]biphenyl, 4,4-dicyanatobenzophenone, 1,3-bis(4-cyanatophenyl)-2-propen-1-one, bis(4-cyanatophenyl) ether, bis(4-cyanatophenyl) sulfide, bis(4-cyanatophenyl) sulfone, 4-cyanatobenzoic acid-4-cyanatophenyl ester (4-cyanatophenyl-4-cyanatobenzoate), bis-(4-cyanatophenyl) carbonate, 1,3-bis(4-cyanatophenyl)adamantane, 1,3-bis(4-cyanatophenyl)-5,7-dimethyladamantane, and 3,3-bis(4-cyanatophenyl)isobenzofuran-1(3H)-one (phen Examples include o-cresolphthalein cyanate, 3,3-bis(4-cyanato-3-methylphenyl)isobenzofuran-1(3H)-one (o-cresolphthalein cyanate), 9,9-bis(4-cyanatophenyl)fluorene, 9,9-bis(4-cyanato-3-methylphenyl)fluorene, 9,9-bis(2-cyanato-5-biphenylyl)fluorene, tris(4-cyanatophenyl)methane, 1,1,1-tris(4-cyanatophenyl)ethane, 1,1,3-tris(4-cyanatophenyl)propane, α,α,α'-tris(4-cyanatophenyl)-1-ethyl-4-isopropylbenzene, 1,1,2,2-tetrakis(4-cyanatophenyl)ethane, tetrakis(4-cyanatophenyl)methane, etc.

[0043] Furthermore, examples of cyanate ester compounds (III) include 2,4,6-tris(N-methyl-4-cyanatoanilino)-1,3,5-triazine, 2,4-bis(N-methyl-4-cyanatoanilino)-6-(N-methylanilino)-1,3,5-triazine, bis(N-4-cyanato-2-methylphenyl)-4,4'-oxydiphthalimide, bis(N-3-cyanato-4-methylphenyl)-4,4'-oxydiphthalimide, bis(N-4-cyanatophenyl)-4,4'-oxydiphthalimide, and bis(N-4-cyanato-2-methylphenyl)- Examples include 4,4'-(hexafluoroisopropylidene)diphthalimide, tris(3,5-dimethyl-4-cyanatobenzyl)isocyanurate, 2-phenyl-3,3-bis(4-cyanatophenyl)phthalimidine, 2-(4-methylphenyl)-3,3-bis(4-cyanatophenyl)phthalimidine, 2-phenyl-3,3-bis(4-cyanato-3-methylphenyl)phthalimidine, 1-methyl-3,3-bis(4-cyanatophenyl)indorin-2-one, and 2-phenyl-3,3-bis(4-cyanatophenyl)indorin-2-one.

[0044] Furthermore, examples of cyanate ester compounds (III) include phenol novolac resins and cresol novolac resins (obtained by reacting phenol, alkyl-substituted phenol, or halogen-substituted phenol with formaldehyde compounds such as formalin or paraformaldehyde in an acidic solution by known methods), trisphenol novolac resins (obtained by reacting hydroxybenzaldehyde and phenol in the presence of an acidic catalyst), fluorene novolac resins (obtained by reacting fluorenone compounds with 9,9-bis(hydroxyaryl)fluorenes in the presence of an acidic catalyst), phenol aralkyl resins, cresol aralkyl resins, naphthol aralkyl resins, and biphenyl aralkyl resins (obtained by reacting bishalogenomethyl compounds represented by Ar4-(CH2Z')2 with phenol compounds with or without an acidic catalyst by known methods, or bis(alkoxymethyl) compounds represented by Ar4-(CH2OR)2). Examples include phenolic resins obtained by reacting a bis(hydroxymethyl) compound, such as a compound represented by Ar4-(CH2OH)2, with a phenolic compound in the presence of an acidic catalyst, or by polycondensation of an aromatic aldehyde compound, an aralkyl compound, and a phenolic compound; phenol-modified xyleneformaldehyde resin (obtained by reacting xyleneformaldehyde resin with a phenolic compound in the presence of an acidic catalyst by a known method); modified naphthaleneformaldehyde resin (obtained by reacting naphthaleneformaldehyde resin with a hydroxy-substituted aromatic compound in the presence of an acidic catalyst by a known method); phenol-modified dicyclopentadiene resin; and phenolic resin having a polynaphthalene ether structure (obtained by dehydration condensation of a polyvalent hydroxynaphthalene compound having two or more phenolic hydroxyl groups in one molecule in the presence of a basic catalyst by a known method), which are then esterified with cyanate by the same method as described above. The above-mentioned cyanate ester compound (III) may be used alone or as a mixture of two or more.

[0045] The content of cyanate ester compound (III) in the resin composition of this embodiment is preferably 5 parts by mass or more and 70 parts by mass or less, more preferably 10 parts by mass or more and 60 parts by mass or less, and even more preferably 15 parts by mass or more and 55 parts by mass or less, per 100 parts by mass of the resin solids of the resin composition of this embodiment.

[0046] (Component (IV): Polyphenylene ether) The resin composition of this embodiment may preferably contain polyphenylene ether (hereinafter sometimes referred to as polyphenylene ether (IV) or component (IV)) as component (IV). Polyphenylene ether (IV) may be a modified polyphenylene ether in which some or all of its terminals are functionalized with ethylenically unsaturated groups such as vinylbenzyl groups, epoxy groups, amino groups, hydroxyl groups, mercapto groups, carboxyl groups, methacrylic groups, and silyl groups. These may be used individually or in combination of two or more. Examples of modified polyphenylene ethers with hydroxyl groups at the end include SA90 manufactured by SABIC Innovative Plastics. Examples of polyphenylene ethers with methacrylic groups at the end include SA9000 manufactured by SABIC Innovative Plastics. Examples of polyphenylene ethers with vinylbenzyl groups at the end include OPE-2St1200 and OPE-2St2200 manufactured by Mitsubishi Gas Chemical Company. The method for producing modified polyphenylene ether is not particularly limited as long as it achieves the effects of the present invention. For example, it can be produced by the method described in Japanese Patent No. 4591665.

[0047] (Component (V): Additive) The resin composition of this embodiment may also contain other additives as component (V), such as radical initiators, compatibilizers, curing accelerators, fillers, and flame retardants. It may also be included as an additive to block copolymer (I).

[0048] Conventional known radical initiators can be used. Examples of thermal radical initiators include, but are not limited to, diisopyrubenzene hydroperoxide (permyl P), cumene hydroperoxide (permyl H), t-butyl hydroperoxide (perbutyl H), and other hydroperoxides, as well as α,α-bis(t-butylperoxy-m-isopropyl)benzene (perbutyl P), dicumyl peroxide (permyl D), 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane (perhexa 25B), t-butylcumyl peroxide (perbutyl C), di-t-butyl peroxide (perbutyl D), and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane. Examples include dialkyl peroxides such as xy)hexyn-3 (perhexyn 25B) and t-butylperoxy-2-ethylhexanoate (perbutyl O), ketone peroxides, peroxyketals such as n-butyl 4,4-di-(t-butylperoxy)valerate (perhexa V), organic peroxides such as diacyl peroxides, peroxydicarbonates, and peroxyesters, and azo compounds such as 2,2-azobisisobutylnitrile, 1,1'-(cyclohexane-1-1 carbonitrile), 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). These may be used individually or in combination of two or more.

[0049] Compatibilizers are added to improve the compatibility of the aforementioned components, and conventionally known compatibilizers can be used. Examples of compatibilizers include maleic anhydride-modified styrene elastomers, hydrocarbon resins, and styrene oligomers. The compatibilizer may be used alone or in combination of two or more types. Furthermore, the SP value of component (III) determined by the Fedors method was 17 (J / cm²). 3 ) 1 / 2 More than 23(J / cm 3 ) 1 / 2We found that the block copolymer (I) is compatible even without the use of a compatibility aid if the following conditions are met. This is thought to be because the block copolymer of component (I) contains 30-85% by mass of random blocks, which increases its SP value and brings it closer to the SP value of component (III), making component (I) more compatible with the curing reaction system consisting of components (II) and (III). The SP value of component (III) is 17 (J / cm²). 3 ) 1 / 2 More than 23(J / cm 3 ) 1 / 2 In the following cases, components (I), (II), and (III) tend to exhibit sufficient compatibility even without the addition of a compatibility aid, which is preferable from the viewpoint of not affecting dielectric properties, etc., due to the addition of a compatibility aid.

[0050] As a curing accelerator, it is added to promote the reactivity between the aforementioned components, and conventionally known ones can be used. Examples include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators. The curing accelerator may be used alone or in combination of two or more types.

[0051] Phosphorus-based curing accelerators include, but are not limited to, triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate, with triphenylphosphine and tetrabutylphosphonium decanoate being preferred.

[0052] Examples of amine-based curing accelerators include, but are not limited to, trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.

[0053] Imidazole-based curing accelerators are not limited to the following, but include, for example, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenyl Ruimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-tri Zin, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2 Examples include imidazole compounds such as phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins, with 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole being preferred. Commercial imidazole-based curing accelerators may be used, such as P200-H50 manufactured by Mitsubishi Chemical Corporation.

[0054] Guanidine-based curing accelerators include, but are not limited to, dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]deca-5-ene, 7-methyl-1,5,7-to Examples include riazabicyclo[4.4.0]deca-5-ene, 1-methyl biguanide, 1-ethyl biguanide, 1-n-butyl biguanide, 1-n-octadecyl biguanide, 1,1-dimethyl biguanide, 1,1-diethyl biguanide, 1-cyclohexyl biguanide, 1-allyl biguanide, 1-phenyl biguanide, 1-(o-tolyl) biguanide, and the like, with dicyandiamide and 1,5,7-triazabicyclo[4.4.0]deca-5-ene being preferred.

[0055] Examples of metal-based hardening accelerators include, but are not limited to, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, and organomanganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0056] Examples of fillers include, but are not limited to, inorganic fillers such as silica, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, calcium sulfate, barium sulfate, carbon black, glass fibers, glass beads, glass balloons, glass flakes, graphite, titanium dioxide, potassium titanate whiskers, carbon fiber, alumina, kaolin clay, silicic acid, calcium silicate, quartz, mica, talc, clay, zirconia, potassium titanate, alumina, and metal particles; and organic fillers such as wood chips, wood powder, pulp, and cellulose nanofibers. These can be used individually or in combination. The shape of these fillers can be flaky, spherical, granular, powdery, or irregularly shaped; there are no particular restrictions. From the viewpoint of dielectric properties, silica is preferred as the filler, and examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica, and the like.

[0057] Examples of flame retardants include, but are not limited to, halogenated flame retardants such as bromine compounds, phosphorus-based flame retardants such as aromatic compounds, and flame retardants containing aromatic bromine compounds such as metal hydroxides, alkyl sulfonates, antimony trioxide, aluminum hydroxide, magnesium hydroxide, zinc borate, hexabromobenzene, decabromodiphenylethane, 4,4-dibromoviphenyl, and ethylenebistetrabromophthalimide. These flame retardants are used individually or in combination of two or more. Among the above flame retardants are so-called flame retardant enhancers, which have low flame retardant effects on their own but exhibit a synergistically superior effect when used in combination with other flame retardants.

[0058] The fillers and flame retardants mentioned above can also be of a type that has been pre-treated with a surface treatment agent such as a silane coupling agent. Examples of surface treatment agents include, but are not limited to, fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, and the like. These may be used individually or in combination of two or more types.

[0059] Other additives are not particularly limited as long as they are commonly used in the formulation of resin compositions and / or cured products. Other additives include, but are not limited to, pigments and / or colorants such as carbon black and titanium dioxide; lubricants such as stearic acid, behenic acid, zinc stearate, calcium stearate, magnesium stearate, and ethylenebisstearamide; release agents; plasticizers such as organic polysiloxanes, fatty acid esters such as phthalate esters, adipic acid ester compounds, and azelaic acid ester compounds, and mineral oil; antioxidants such as hindered phenol and phosphorus-based heat stabilizers; hindered amine-based light stabilizers; benzotriazole-based ultraviolet absorbers; antistatic agents; organic fillers; thickeners; defoamers; leveling agents; and resin additives such as adhesion enhancers. These may be used individually or in combination of two or more.

[0060] In the resin composition of this embodiment, from the viewpoint of low dielectric constant and low dielectric loss tangent, it is preferable that it does not contain pigments, colorants, lubricants, mold release agents, or antistatic agents.

[0061] The resin composition of this embodiment may be obtained by melt-kneading each component, or by dissolving each component in a solvent and stirring (hereinafter referred to as "varnish"), but varnish is preferred from the viewpoint of ease of handling. Examples of solvents, though not limited to the following, include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone. The solvent may be used alone or in combination of two or more types.

[0062] [Cured product] The cured product of this embodiment is the cured product of the resin composition of this embodiment described above. The cured product of this embodiment includes not only a state in which the entire amount of curable resin has cured, but also a so-called semi-cured state in which only a portion of the resin has cured. Therefore, for example, in the process of manufacturing an electronic circuit board material using the resin composition of this embodiment, there may be a step to further cure the cured product. The cured product of this embodiment is obtained by curing the resin composition of this embodiment at an arbitrary temperature and for an arbitrary time. Specifically, the reaction temperature is preferably 80°C or higher, more preferably 100°C or higher, and even more preferably 120°C or higher. The reaction time is preferably 10 to 240 minutes, more preferably 20 to 230 minutes, and even more preferably 30 to 220 minutes. If the resin composition is a varnish, it is preferable to perform the curing reaction after removing the solvent. As for the drying method, conventional known methods such as heating and hot air blowing may be used, and it is preferable to perform the drying at a temperature lower than the curing reaction temperature, and drying is performed so that the amount of solvent in the resin composition is preferably 10% by mass or less, more preferably 5% by mass or less.

[0063] [Resin film] The resin film of this embodiment includes the cured product of this embodiment. The resin film of this embodiment is obtained by spreading a varnish made of the resin composition of this embodiment onto a uniform thin film and removing the solvent by drying it as described above. The resin film of this embodiment can be stored by being rolled up. If the resin film of this embodiment has a protective film, it can be used after the protective film is removed.

[0064] [Prepreg] The prepreg of this embodiment is a composite of a substrate and the resin composition and / or cured product of this embodiment. Specifically, it includes the resin composition and / or cured product of this embodiment impregnated or coated onto the substrate. The prepreg is obtained, for example, by impregnating a substrate such as glass cloth with a varnish made of the resin composition of this embodiment, and then removing the solvent by the drying method described above. During the drying process, some of the resin components in the varnish harden, and the prepreg typically contains both the unhardened resin composition and the hardened material. Examples of substrates include various glass cloths such as roving cloth, cloth, chopped mat, and surfacing mat; asbestos cloth, metal fiber cloth, and other synthetic or natural inorganic fiber cloths; woven or nonwoven fabrics obtained from liquid crystal fibers such as fully aromatic polyamide fibers, fully aromatic polyester fibers, and polybenzoxazole fibers; natural fiber cloths such as cotton cloth, linen cloth, and felt; natural cellulose-based substrates such as carbon fiber cloth, kraft paper, cotton paper, and cloths obtained from paper-glass blended yarns; and polytetrafluoroethylene porous films, but glass cloth is preferred from the viewpoint of dielectric performance. These substrates can be used individually or in combination of two or more. The proportion of solid content of the resin composition in the prepreg of this embodiment is preferably 30 to 80% by mass, and more preferably 40 to 70% by mass. When the above proportion is 30% by mass or more, the insulation reliability tends to be even better when the prepreg is used for electronic circuit boards, etc. When the above proportion is 80% by mass or less, the mechanical properties such as rigidity tend to be even better in applications such as electronic circuit boards.

[0065] [Electronic circuit board materials] The electronic circuit board material of this embodiment includes the cured product of this embodiment. The electronic circuit board material of this embodiment can be manufactured using a cured product containing a block copolymer (I). Electronic circuit board materials include prepregs, copper-clad laminates, solder resists, package substrates, coverlay films, electromagnetic field shields, and the adhesive layers, heat dissipation layers, dielectric layers, and magnetic permeable layers contained therein.

[0066] The printed circuit board used as the electronic circuit board material in this embodiment is, for example, Step (a): A step of forming a resin layer by laminating a resin film containing the block copolymer (I) onto a substrate. Step (b): A step of heating and pressurizing the resin layer to flatten it. Step (c): A step of further forming a wiring layer on the resin layer. It can be manufactured through the following processes.

[0067] The method for laminating the resin layer onto the substrate in step (a) is not particularly limited, but examples include lamination using a multi-stage press, a vacuum press, an atmospheric pressure laminator, or a laminator that heats and pressurizes under vacuum. The method using a laminator that heats and pressurizes under vacuum is preferred. In this method, even if the circuit board has fine wiring circuits on its surface, there are no voids and the spaces between the circuits can be filled with resin. The lamination may be done in batch mode or in a continuous mode using rolls, etc. The substrate is not particularly limited, and glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, polyphenylene ether substrates, fluororesin substrates, etc., can be used. The surface on which the resin layer of the substrate is laminated may be roughened beforehand, and the number of substrate layers is not limited.

[0068] In step (b), the resin film and substrate laminated in step (a) are heated and pressurized to flatten them. The conditions can be arbitrarily adjusted depending on the type of substrate and the composition of the resin film, but for example, a temperature of 100 to 300°C, a pressure of 0.2 to 20 MPa, and a time of 30 to 180 minutes are preferred.

[0069] In step (c), a circuit layer is formed on the resin layer, which is created by heating and pressurizing the resin film and substrate. The formation method is not particularly limited and conventionally known methods can be used, but for example, it may be formed by etching methods such as the subtractive method or the semi-additive method. The subtractive method is a method for forming a desired circuit by creating an etching resist layer with a shape corresponding to the desired pattern shape on a metal layer, and then dissolving and removing the metal layer in the areas where the resist has been removed using a chemical solution during a subsequent development process. The semi-additive method involves forming a metal film on the surface of a resin layer using electroless plating, creating a plating resist layer with a shape corresponding to the desired pattern on the metal film, then forming a metal layer using electroplating, and finally removing the unnecessary electroless plating layer with a chemical solution to form the desired circuit layer.

[0070] Furthermore, holes such as via holes may be formed in the resin layer as needed, and there are no particular limitations on the method of forming the holes; conventionally known methods can be used. Examples of methods for forming the holes include NC drills, carbon dioxide lasers, UV lasers, YAG lasers, plasma, etc.

[0071] [Laminate] Furthermore, the laminate of this embodiment comprises a cured product selected from the group consisting of the resin film of this embodiment and the prepreg of this embodiment, and a metal foil. In other words, the laminate in this embodiment may be a metal-clad laminate. The metal-clad laminate is obtained by laminating a resin film or prepreg made of the resin composition of this embodiment with a metal foil and curing it, with a portion of the metal foil removed from the metal-clad laminate. Metal-clad laminates preferably have a form in which a cured prepreg (also called a "cured composite") and a metal foil are laminated and tightly bonded together, and are suitably used as electronic circuit board materials. Examples of metal foils include aluminum foil and copper foil, and among these, copper foil is preferred because of its low electrical resistance. The cured composite material combined with metal foil can consist of one or multiple sheets, and depending on the application, the metal foil is layered on one or both sides of the composite material to form a laminate.

[0072] One method for manufacturing the laminate of this embodiment is to form a composite (for example, the aforementioned prepreg) composed of the resin composition of this embodiment and a substrate, stack this with a metal foil, and then cure the resin composition to obtain a laminate in which a cured laminate and a metal foil are laminated. One particularly preferred application of the laminate is a printed circuit board. Preferably, the printed circuit board is formed by removing at least a portion of the metal foil from the metal-clad laminate. The printed circuit board of this embodiment can typically be formed by a pressure-heat molding method using the prepreg of this embodiment described above. The same prepregs as described above can be used as the base material. The printed circuit board of this embodiment, by containing the resin composition of this embodiment, has excellent heat resistance and electrical properties (low dielectric constant and low dielectric loss tangent), can suppress fluctuations in electrical properties due to environmental changes, and has excellent insulation reliability and mechanical properties. [Examples]

[0073] The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited in any way by the following examples and comparative examples.

[0074] The methods for identifying the structure and measuring the physical properties of the block copolymer (component (I)) used in the following examples and comparative examples are shown below.

[0075] [Method for identifying the structure and measuring the physical properties of block copolymers] ((1) Content of vinyl aromatic monomer units (styrene) in the block copolymer) Using the block copolymer before hydrogenation, proton nuclear magnetic resonance ( 1 The measurement was performed using the 1H-NMR method. The measurement was performed using a JNM-LA400 (manufactured by JEOL), with deuterated chloroform as the solvent, a sample concentration of 50 mg / mL, an observation frequency of 400 MHz, tetramethylsilane as the chemical shift reference, a pulse delay of 2.904 seconds, 64 scans, a pulse width of 45°, and a measurement temperature of 26°C. The styrene content was calculated using the integrated total styrene aromatic signal in the spectrum at 6.2–7.5 ppm.

[0076] ((2) Amount of vinyl bonding in block copolymer) Using the block copolymer before hydrogenation, proton nuclear magnetic resonance ( 1 The amount of vinyl binding was measured by 1H-NMR. The measurement conditions and the method for processing the measurement data were the same as in (1) above. The amount of vinyl bond is calculated by determining the integral value per H for each bond type from the integral values ​​of the signals attributed to 1,4-bonds and 1,2-bonds, and then dividing the integral value of the 1,2-bond by the sum of the integral values ​​of the 1,4-bond and 1,2-bond (1,2-bond is the case for butadiene; in the case of isoprene, it would be a 3,4-bond).

[0077] (3) Molecular weight and molecular weight distribution of block copolymers The molecular weight of the block copolymer before modification and hydrogenation was measured by GPC [instrument: LC-10 (Shimadzu Corporation), column: TSKgelGMHXL (4.6 mm × 30 cm)]. Tetrahydrofuran was used as the solvent. The measurement was performed at a temperature of 35°C. The molecular weight is the weight-average molecular weight determined by using a calibration curve (created using the peak molecular weight of standard polystyrene) derived from measurements of commercially available standard polystyrene, based on the molecular weight of the peaks in the chromatogram. In cases where there are multiple peaks in the chromatogram, the molecular weight was calculated as the average molecular weight derived from the molecular weight of each peak and the composition ratio of each peak (determined from the area ratio of each peak in the chromatogram). Furthermore, the molecular weight distribution is the ratio (Mw / Mn) of the obtained weight-average molecular weight (Mw) to the number-average molecular weight (Mn).

[0078] ((4) Hydrogenation rate of double bonds in conjugated diene monomer units of block copolymers) Using the hydrogenated block copolymer, proton nuclear magnetic resonance ( 1 The hydrogenation rate of the double bonds in conjugated diene monomer units was measured using the 1H-NMR method.

[0079] ((5) tanδ peak temperature) A block copolymer was used as the sample, and the sample was cut to a size of 10 mm in width and 40 mm in length to prepare the sample for measurement. Next, the sample for measurement was set in the torsion-type geometry of the ARES instrument (manufactured by TA Instruments Co., Ltd., product name), and tanδ was determined under conditions of an effective measurement length of 25 mm, strain of 0.3%, frequency of 1 Hz, and heating rate of 3 °C / min. The tanδ peak temperature was determined from the peak detected by the automatic measurement of the RSI Orchestrator (manufactured by TA Instruments Co., Ltd., product name).

[0080] [Block copolymers, materials for resin compositions] (Preparation of hydrogenated catalyst) In the examples and comparative examples described later, the hydrogenation catalyst used to produce the block copolymer was prepared by the following method. A reaction vessel equipped with a stirring device was purged with nitrogen, and 1 liter of dried and purified cyclohexane was charged into it. Next, 100 mmol of bis(η5-cyclopentadienyl)titanium dichloride was added. While stirring thoroughly, an n-hexane solution containing 200 mmol of trimethylaluminum was added, and the reaction was carried out at room temperature for about 3 days. This yielded a hydrogenated catalyst.

[0081] (Manufacturing of block copolymers) Block copolymers (indicated as "polymers" in the table) containing vinyl aromatic monomer units and conjugated diene monomer units were prepared as follows. Hereinafter, a random polymer block (A) containing conjugated diene monomer units and the vinyl aromatic monomer units may be referred to as "polymer block (A), A (random), A". Furthermore, polymer blocks (B) mainly composed of vinyl aromatic monomer units are sometimes referred to as "polymer block (B), B (aromatic), B". Furthermore, polymer blocks (C) mainly composed of conjugated diene monomer units are sometimes referred to as "polymer block (C), C (diene), C".

[0082] (Block copolymer (1)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 50°C. Then, 0.081 parts by mass of n-butyllithium (hereinafter referred to as "Bu-Li"), 1.5 moles of N,N,N',N'-tetramethylethylenediamine (hereinafter referred to as "TMEDA") per mole of Bu-Li, and 0.04 moles of sodium-t-pentoxide (hereinafter referred to as "NaOAm") per mole of Bu-Li were added to 100 parts by mass of the total amount of butadiene monomer and styrene monomer added to the reactor (hereinafter referred to as "total monomer"). As the first step, a cyclohexane solution (22% by mass) containing 9.0 parts by mass of styrene was added over 9 minutes, followed by a further 10 minutes of reaction. The polymerization temperature at this time was adjusted to 50°C. In the second step, a cyclohexane solution (22% by mass) containing 18 parts by mass of styrene and 72 parts by mass of butadiene was continuously added to the reactor over 90 minutes, followed by a 10-minute reaction. The polymerization temperature at this time was adjusted to 55°C. In the third step, a cyclohexane solution (22% by mass) containing 8.0 parts by mass of styrene was added over 5 minutes, and the reaction was allowed to continue for another 10 minutes. The polymerization temperature was adjusted to 55°C at this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 2 hours at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (1). The block copolymer (1) obtained as described above had a styrene content of 35% by mass, a polymer block (A) content of 83% by mass, a polymer block (B) content of 17% by mass, a vinyl bond content of 85 mol% in the block copolymer, a weight-average molecular weight of 145,000, a molecular weight distribution of 1.20, and a hydrogenation rate of 90 mol%. The physical properties of block copolymer (1) (referred to as copolymer (1) in the table) are shown in Table 1.

[0083] (Block copolymer (2)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.091 parts by mass of Bu-Li, 1.2 moles of TMEDA per mole of Bu-Li, and 0.02 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor. As the first step, a cyclohexane solution (25% by mass) containing 12 parts by mass of styrene was added over 15 minutes, followed by a further 10 minutes of reaction. The polymerization temperature at this time was adjusted to 55°C. In the second step, a cyclohexane solution (25% by mass) containing 30 parts by mass of styrene and 45 parts by mass of butadiene was continuously added to the reactor over 90 minutes, followed by a reaction over 15 minutes. The polymerization temperature at this time was adjusted to 60°C. In the third step, a cyclohexane solution (25% by mass) containing 13 parts by mass of styrene was added over 15 minutes, followed by a further 10 minutes of reaction. The polymerization temperature was adjusted to 65°C during this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 2 hours at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (2). The block copolymer (2) obtained as described above had a styrene content of 55% by mass, a polymer block (A) content of 75% by mass, a polymer block (B) content of 25% by mass, a vinyl bond content of 60 mol% in the block copolymer, a weight-average molecular weight of 252,000, a molecular weight distribution of 1.18, and a hydrogenation rate of 98 mol%. The physical properties of block copolymer (2) (referred to as copolymer (2) in the table) are shown in Table 1.

[0084] (Block copolymer (3)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.088 parts by mass of Bu-Li, 1.3 moles of TMEDA per mole of Bu-Li, and 0.05 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor. As the first step, a cyclohexane solution (22% by mass) containing 9 parts by mass of styrene was added over 10 minutes, and the reaction was then allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 50°C. In the second step, a cyclohexane solution (22% by mass) containing 16 parts by mass of styrene and 64 parts by mass of butadiene was continuously added to the reactor over 70 minutes, followed by a 10-minute reaction. The polymerization temperature at this time was adjusted to 55°C. In the third step, a cyclohexane solution (22% by mass) containing 8 parts by mass of styrene was added over 10 minutes, and the reaction was allowed to continue for another 10 minutes. The polymerization temperature was adjusted to 60°C at this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 2 hours at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (3). The block copolymer (3) obtained as described above had a styrene content of 33% by mass, a polymer block (A) content of 83% by mass, a polymer block (B) content of 17% by mass, a vinyl bond content of 75 mol% in the block copolymer, a weight-average molecular weight of 151,000, a molecular weight distribution of 1.05, and a hydrogenation rate of 98 mol%. The physical properties of block copolymer (3) (referred to as copolymer (3) in the table) are shown in Table 1.

[0085] (Block copolymer (4)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.078 parts by mass of Bu-Li, 1.2 moles of TMEDA per mole of Bu-Li, and 0.02 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor. As the first step, a cyclohexane solution (22% by mass) containing 13 parts by mass of styrene was added over 15 minutes, followed by a further 10 minutes of reaction. The polymerization temperature at this time was adjusted to 50°C. In the second step, a cyclohexane solution (22% by mass) containing 30 parts by mass of styrene and 45 parts by mass of butadiene was continuously added to the reactor over 60 minutes, followed by a 10-minute reaction. The polymerization temperature at this time was adjusted to 55°C. In the third step, a cyclohexane solution (22% by mass) containing 12 parts by mass of styrene was added over 15 minutes, followed by a further 10 minutes of reaction. The polymerization temperature was adjusted to 60°C during this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 1 hour at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (4). The block copolymer (4) obtained as described above had a styrene content of 55% by mass, a polymer block (A) content of 75% by mass, a polymer block (B) content of 25% by mass, a vinyl bond content of 60 ml in the block copolymer, a weight-average molecular weight of 142,000, a molecular weight distribution of 1.18, and a hydrogenation rate of 50 ml. The physical properties of block copolymer (4) (referred to as copolymer (4) in the table) are shown in Table 1.

[0086] (Block copolymer (5)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.078 parts by mass of Bu-Li, 1.0 mole of TMEDA per mole of Bu-Li, and 0.02 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor. As the first step, a cyclohexane solution (22% by mass) containing 13 parts by mass of styrene was added over 15 minutes, followed by a further 10 minutes of reaction. The polymerization temperature at this time was adjusted to 50°C. In the second step, a cyclohexane solution (22% by mass) containing 30 parts by mass of styrene and 45 parts by mass of butadiene was continuously added to the reactor over 60 minutes, followed by a 10-minute reaction. The polymerization temperature at this time was adjusted to 55°C. In the third step, a cyclohexane solution (22% by mass) containing 12 parts by mass of styrene was added over 15 minutes, followed by a further 10 minutes of reaction. The polymerization temperature was adjusted to 60°C during this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 1 hour at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (5). The block copolymer (5) obtained as described above had a styrene content of 55% by mass, a polymer block (A) content of 75% by mass, a polymer block (B) content of 25% by mass, a vinyl bond content of 75 ml in the block copolymer, a weight-average molecular weight of 139,000, a molecular weight distribution of 1.08, and a hydrogenation rate of 50 ml. The physical properties of block copolymer (5) (referred to as copolymer (5) in the table) are shown in Table 1.

[0087] (Block copolymer (6)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.078 parts by mass of Bu-Li, 1.0 mole of TMEDA per mole of Bu-Li, and 0.02 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor. As the first step, a cyclohexane solution (22% by mass) containing 13 parts by mass of styrene was added over 15 minutes, followed by a further 10 minutes of reaction. The polymerization temperature at this time was adjusted to 50°C. In the second step, a cyclohexane solution (22% by mass) containing 45 parts by mass of styrene and 40 parts by mass of butadiene was continuously added to the reactor over 60 minutes, and then the reaction was allowed to proceed for another 20 minutes. The polymerization temperature at this time was adjusted to 55°C. In the third step, a cyclohexane solution (22% by mass) containing 12 parts by mass of styrene was added over 15 minutes, followed by a further 10 minutes of reaction. The polymerization temperature was adjusted to 60°C during this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 1 hour at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (6). The block copolymer (6) obtained as described above had a styrene content of 70% by mass, a polymer block (A) content of 75% by mass, a polymer block (B) content of 25% by mass, a vinyl bond content of 75 ml in the block copolymer, a weight-average molecular weight of 139,000, a molecular weight distribution of 1.10, and a hydrogenation rate of 50 ml. The physical properties of block copolymer (6) (referred to as copolymer (6) in the table) are shown in Table 1.

[0088] (Block copolymer (7)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 50°C. Then, 0.10 parts by mass of Bu-Li and 0.045 moles of TMEDA per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor, and no NaOAm was added. As the first step, a cyclohexane solution (22% by mass) containing 10 parts by mass of styrene was added over 10 minutes, and the reaction was then allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 50°C. In the second step, a cyclohexane solution (22% by mass) containing 45 parts by mass of styrene and 40 parts by mass of butadiene was continuously added to the reactor over 60 minutes, and then the reaction was allowed to proceed for another 20 minutes. The polymerization temperature at this time was adjusted to 55°C. In the third step, a cyclohexane solution (22% by mass) containing 10 parts by mass of styrene was added over 10 minutes, and the reaction was allowed to continue for another 10 minutes. The polymerization temperature was adjusted to 60°C at this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 1.5 hours at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (7). The block copolymer (7) obtained as described above had a styrene content of 65% by mass, a polymer block (A) content of 80% by mass, a polymer block (B) content of 20% by mass, a vinyl bond content of 30 ml in the block copolymer, a weight-average molecular weight of 196,000, a molecular weight distribution of 1.12, and a hydrogenation rate of 75 ml. The physical properties of block copolymer (7) (referred to as copolymer (7) in the table) are shown in Table 1.

[0089] (Block copolymer (8)) (BAB) Similar to the production of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added, and the temperature was adjusted to 45°C. Then, 0.077 parts by mass of Bu-Li and 1.1 moles of TMEDA per mole of Bu-Li were added to 100 parts by mass of the total monomer. NaOAm was not added. As the first step, a cyclohexane solution (22% by mass) containing 8 parts by mass of styrene was added over 6 minutes, followed by polymerization for 10 minutes. The polymerization temperature at this time was adjusted to 45°C. In the second step, a cyclohexane solution (22% by mass) containing 64 parts by mass of styrene and 23 parts by mass of butadiene was continuously added to the reactor at a constant rate over 90 minutes, followed by polymerization for 15 minutes. The polymerization temperature at this time was adjusted to 48°C. In the third step, a cyclohexane solution (22% by mass) containing 8 parts by mass of styrene was added over 6 minutes, and the reaction was allowed to continue for 10 minutes. The polymerization temperature was adjusted to 48°C during this time. Next, a hydrogenation operation similar to that performed for the production of the block copolymer (1) was carried out. The obtained block copolymer (8) had a styrene content of 77% by mass, a polymer block (A) content of 84% by mass, a polymer block (B) content of 16% by mass, a vinyl bond content of 15 ml in the block copolymer, a weight-average molecular weight of 204,000, and a hydrogenation rate of 95 ml.

[0090] (Block copolymer (9)) (BAB) Similar to the production of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added, and the temperature was adjusted to 45°C. Then, 0.080 parts by mass of Bu-Li and 1.8 moles of TMEDA per mole of Bu-Li were added to 100 parts by mass of the total monomer. NaOAm was not added. As the first step, a cyclohexane solution (22% by mass) containing 4 parts by mass of styrene was added over 6 minutes, followed by polymerization for 10 minutes. The polymerization temperature at this time was adjusted to 45°C. In the second step, a cyclohexane solution (22% by mass) containing 85 parts by mass of styrene and 10 parts by mass of butadiene was continuously added to the reactor at a constant rate over 90 minutes, followed by polymerization for 15 minutes. The polymerization temperature at this time was adjusted to 50°C. In the third step, a cyclohexane solution (22% by mass) containing 4 parts by mass of styrene was added over 6 minutes, and the reaction was allowed to continue for 10 minutes. The polymerization temperature was adjusted to 53°C during this time. Next, a hydrogenation operation similar to that performed for the production of the block copolymer (1) was carried out. The obtained block copolymer (9) had a styrene content of 83% by mass, a polymer block (A) content of 92% by mass, a polymer block (B) content of 8% by mass, a vinyl bond content of 40 ml in the block copolymer, a weight-average molecular weight of 201,000, and a hydrogenation rate of 95 ml.

[0091] (Block copolymer (10)) (BA) Similar to the production of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.073 parts by mass of Bu-Li, 1.5 moles of TMEDA per mole of Bu-Li, and 0.04 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of total monomer. A cyclohexane solution (22% by mass) containing 19.6 parts by mass of styrene was added over 11 minutes, followed by a 10-minute reaction. The polymerization temperature was adjusted to 55°C. Next, a cyclohexane solution (monomer concentration 22% by mass) containing 13.4 parts by mass of styrene and 75.6 parts by mass of butadiene was continuously added to the reactor at a constant rate over 90 minutes, and then the reaction was allowed to continue for 10 minutes. The polymerization temperature at this time was adjusted to 60°C. Next, a hydrogenation operation similar to that performed for the production of the block copolymer (1) was carried out. The obtained block copolymer (10) had a styrene content of 33.0% by mass, a polymer block (A) content of 80.4% by mass, a polymer block (B) content of 19.6% by mass, a vinyl bond content of 75.0 mol% in the block copolymer, a weight-average molecular weight of 150,000, and a hydrogenation rate of 98 mol%.

[0092] (Block copolymer (11)) (CAB) Similar to the production of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.071 parts by mass of Bu-Li per 100 parts by mass of total monomer, 1.4 moles of TMEDA per mole of Bu-Li, and 0.04 moles of NaOAm per mole of Bu-Li were added. As the first step, a cyclohexane solution (22% by mass) containing 3 parts by mass of butadiene was added over 3 minutes, and the reaction was then allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 50°C. Next, in the second step, a cyclohexane solution (22% by mass) containing 12.9 parts by mass of styrene and 73.1 parts by mass of butadiene was continuously added to the reactor at a constant rate over 90 minutes, and the reaction was continued for another 30 minutes. The polymerization temperature at this time was adjusted to 60°C. Next, in the third step, a cyclohexane solution (22% by mass) containing 19.1 parts by mass of styrene was added over 11 minutes, and the reaction was then allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 65°C. Next, a hydrogenation operation similar to that performed for the production of block copolymer (1) was carried out to obtain block copolymer (11). The obtained block copolymer (11) had a styrene content of 32% by mass, polymer block (A) content of 77.9% by mass, polymer block (B) content of 19.1% by mass, polymer block (C) content of 3.0% by mass, vinyl bond content in the block copolymer of 75.0 mol%, weight-average molecular weight of 152,000, and hydrogenation rate of 98 mol%.

[0093] (Block copolymer (12))(BA) × 2 Similar to the production of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.15 parts by mass of n-butyllithium were added per 100 parts by mass of total monomer, 1.5 moles of TMEDA were added per mole of n-butyllithium, and 0.04 moles of NaOAm were added per mole of Bu-Li. As the first step, a cyclohexane solution (22% by mass) containing 19.6 parts by mass of styrene was added over 11 minutes, followed by a further 10 minutes of reaction. The polymerization temperature at this time was adjusted to 55°C. Next, in the second step, a cyclohexane solution (22% by mass) containing 13.4 parts by mass of styrene and 75.6 parts by mass of butadiene was continuously added to the reactor at a constant rate over 90 minutes, and the reaction was continued for another 30 minutes. The polymerization temperature at this time was adjusted to 60°C. Subsequently, ethyl benzoate was added at a rate of 1.0 mole per mole of lithium in n-butyllithium, and the reaction was carried out for 10 minutes to perform the coupling reaction. The coupling reaction temperature was adjusted to 70°C. Next, a hydrogenation operation similar to that performed for the production of block copolymer (1) was carried out to obtain block copolymer (12). The obtained block copolymer (12) had a styrene content of 33.0% by mass, a polymer block (A) content of 80.4% by mass, a polymer block (B) content of 19.6% by mass, a vinyl bond content of 75.0 mol% in the block copolymer, a weight-average molecular weight of 145,000, and a hydrogenation rate of 98 mol%.

[0094] (Block copolymer (13)) (CBAB) Similar to the synthesis of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 50°C. Then, 0.076 parts by mass of Bu-Li, 1.3 moles of TMEDA per mole of Bu-Li, and 0.04 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of the total monomer. Next, as the first step, a cyclohexane solution (22% by mass) containing 3 parts by mass of butadiene was added over 4 minutes, and then the reaction was allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 50°C. Next, in the second step, a cyclohexane solution (22% by mass) containing 6 parts by mass of styrene was added over 6 minutes, and the reaction was then allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 55°C. Next, as the third step, a cyclohexane solution (monomer concentration 22% by mass) containing 21.5 parts by mass of styrene and 64.5 parts by mass of butadiene was continuously added to the reactor at a constant rate over 85 minutes, and then the reaction was allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 60°C. Next, in the fourth step, a cyclohexane solution (22% by mass) containing 5 parts by mass of styrene was added over 5 minutes, and the reaction was then allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 70°C. Next, a hydrogenation operation similar to that performed for the production of block copolymer (1) was carried out to obtain block copolymer (13). The obtained block copolymer (13) had a styrene content of 31.0% by mass, a polymer block (A) content of 85.0% by mass, a polymer block (B) content of 12.0% by mass, a polymer block (C) content of 3.0% by mass, a vinyl bond content of 65.0 ml in the block copolymer, a weight-average molecular weight of 143,000, and a hydrogenation rate of 98.0 ml.

[0095] (Block copolymer (14)) (BCB) Similar to the synthesis of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added, and then 0.135 parts by mass of Bu-Li per 100 parts by mass of total monomer, 0.5 moles of TMEDA per mole of Bu-Li, and 0.04 moles of NaOAm per mole of Bu-Li were added. In the first step, a cyclohexane solution (20% by mass) containing 16 parts by mass of styrene was added over 10 minutes, followed by polymerization for another 10 minutes. The polymerization temperature was adjusted to 60°C. Next, as the second step, a cyclohexane solution (20% by mass) containing 69 parts by mass of butadiene was added over 60 minutes, followed by polymerization for a further 10 minutes. The temperature was controlled to 60°C during polymerization. Next, in the third step, a cyclohexane solution (20% by mass) containing 15 parts by mass of styrene was added over 10 minutes, followed by polymerization for another 10 minutes. The polymerization temperature was controlled to 60°C. The structure of the block copolymer obtained in this way was BCB. Next, a hydrogenation procedure similar to that used for the synthesis of block copolymer (1) was performed to obtain block copolymer (14). The obtained block copolymer (14) had a styrene content of 31% by mass, a vinyl bond content of 49 ml in the block copolymer, a weight-average molecular weight of 75,000, and a hydrogenation rate of 98 ml.

[0096] (Block copolymer (15)) (BCB) Block copolymer (15) was synthesized using the same method as described above for block copolymer (14). However, initially, 0.065 parts by mass of Bu-Li were added per 100 parts by mass of total monomer, 1.8 moles of TMEDA were added per mole of Bu-Li, and 0.04 moles of NaOAm were added per mole of Bu-Li. The amount of styrene in steps 1 and 3 was 12 parts by mass, and the amount of butadiene in step 2 was 88 parts by mass. The structure of the block copolymer obtained in this way was "BCB". Next, a hydrogenation operation similar to that performed for the production of block copolymer (1) was carried out to obtain block copolymer (15). The obtained block copolymer (15) had a styrene content of 24% by mass, a vinyl bond content of 79 mol% in the block copolymer, a weight-average molecular weight of 162,000, and a hydrogenation rate of 98 mol%.

[0097] (Copolymer (16))A Similar to the synthesis of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 50°C. Then, 0.081 parts by mass of Bu-Li, 1.5 moles of TMEDA per mole of Bu-Li, and 0.06 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor. Next, in the second step, a cyclohexane solution (22% by mass) containing 17 parts by mass of styrene and 79 parts by mass of butadiene was continuously added to the reactor at a constant rate over 90 minutes, and the reaction was continued for another 30 minutes. The polymerization temperature at this time was adjusted to 55°C. Next, a hydrogenation procedure similar to that used for the synthesis of the block copolymer (1) was performed to obtain the random copolymer (16). The obtained copolymer (16) had a styrene content of 32% by mass, a vinyl bond content of 50 ml in the block copolymer, a weight-average molecular weight of 201,000, and a hydrogenation rate of 80 ml. Although cracks were relatively suppressed in the cured composition to which the above copolymer (16) was added, the tensile strength of the cured composition and the adhesive strength to the copper foil were worse compared to other block copolymers.

[0098] (Block copolymer (17)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 50°C. Then, 0.075 parts by mass of Bu-Li, 1.3 moles of TMEDA per mole of Bu-Li, and 0.05 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor. As the first step, a cyclohexane solution (22% by mass) containing 34 parts by mass of styrene was added over 40 minutes, followed by a further 20 minutes of reaction. The polymerization temperature at this time was adjusted to 55°C. In the second step, a cyclohexane solution (22% by mass) containing 16 parts by mass of styrene and 64 parts by mass of butadiene was continuously added to the reactor over 70 minutes, followed by a 10-minute reaction. The polymerization temperature at this time was adjusted to 58°C. In the third step, a cyclohexane solution (22% by mass) containing 34 parts by mass of styrene was added over 40 minutes, followed by a further 20 minutes of reaction. The polymerization temperature was adjusted to 60°C during this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 1 hour at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (17). The block copolymer (17) obtained as described above had a styrene content of 84% by mass, a polymer block (A) content of 32% by mass, a polymer block (B) content of 68% by mass, a vinyl bond content of 60 ml in the block copolymer, a weight-average molecular weight of 125,000, a molecular weight distribution of 1.05, and a hydrogenation rate of 40 ml. The physical properties of block copolymer (17) (referred to as copolymer (17) in the table) are shown in Table 1.

[0099] (Block copolymer (18)) (CBAB) Similar to the synthesis of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 50°C. Then, 0.082 parts by mass of Bu-Li and 0.4 moles of TMEDA per mole of Bu-Li were added per 100 parts by mass of total monomer, and no NaOAm was added. Next, as the first step, a cyclohexane solution (25% by mass) containing 10 parts by mass of butadiene was added over 8 minutes, and then the reaction was allowed to continue for another 15 minutes. The polymerization temperature at this time was adjusted to 52°C. Next, as the second step, a cyclohexane solution (25% by mass) containing 3 parts by mass of styrene was added over 2 minutes, and the reaction was then allowed to continue for a further 8 minutes. The polymerization temperature at this time was adjusted to 55°C. Next, as the third step, a cyclohexane solution (monomer concentration 25% by mass) containing 20 parts by mass of styrene and 60 parts by mass of butadiene was continuously added to the reactor at a constant rate over 70 minutes, and then the reaction was allowed to continue for another 15 minutes. The polymerization temperature at this time was adjusted to 60°C. Next, in the fourth step, a cyclohexane solution (25% by mass) containing 3 parts by mass of styrene was added over 2 minutes, and the reaction was then allowed to continue for a further 8 minutes. The polymerization temperature at this time was adjusted to 62°C. Next, a hydrogenation operation similar to that used to produce block copolymer (1) was carried out for approximately 20 minutes to obtain block copolymer (18). The obtained block copolymer (18) had a styrene content of 26% by mass, polymer block (A) content of 50% by mass, polymer block (B) content of 6% by mass, polymer block (C) content of 10% by mass, vinyl bond content in the block copolymer of 15.0 ml, weight-average molecular weight of 155,000, and hydrogenation rate of 10.0 ml.

[0100] (Block copolymer (19)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 55°C. Then, 0.070 parts by mass of Bu-Li and 1.3 moles of TMEDA per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor, and NaOAm was not added. As the first step, a cyclohexane solution (22% by mass) containing 22 parts by mass of styrene was added over 40 minutes, followed by a further 20 minutes of reaction. The polymerization temperature at this time was adjusted to 55°C. In the second step, a cyclohexane solution (22% by mass) containing 31 parts by mass of styrene and 50 parts by mass of butadiene was continuously added to the reactor over 70 minutes, followed by a 10-minute reaction. The polymerization temperature at this time was adjusted to 60°C. In the third step, a cyclohexane solution (22% by mass) containing 23 parts by mass of styrene was added over 40 minutes, followed by a further 20 minutes of reaction. The polymerization temperature was adjusted to 65°C during this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 2 hours at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (19). The block copolymer (19) obtained as described above had a styrene content of 86% by mass, a polymer block (A) content of 45% by mass, a polymer block (B) content of 55% by mass, a vinyl bond content of 26 mol% in the block copolymer, a weight-average molecular weight of 169,000, a molecular weight distribution of 1.11, and a hydrogenation rate of 98 mol%. The physical properties of block copolymer (19) (referred to as copolymer (19) in the table) are shown in Table 1.

[0101] (Block copolymer (20)) (CAC) Similar to the production of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 45°C. Then, 0.079 parts by mass of Bu-Li and 1.2 moles of TMEDA per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor. NaOAm was not added. As the first step, a cyclohexane solution (20% by mass) containing 15 parts by mass of butadiene was added over 10 minutes, followed by polymerization for another 10 minutes. The polymerization temperature was adjusted to 50°C. Next, in the second step, a cyclohexane solution (20% by mass) containing 15 parts by mass of styrene and 70 parts by mass of butadiene was continuously added to the reactor at a constant rate over 60 minutes, and the reaction was continued for another 30 minutes. The polymerization temperature at this time was adjusted to 55°C. In the third step, a cyclohexane solution (20% by mass) containing 15 parts by mass of butadiene was added over 10 minutes, and the reaction was then allowed to continue for another 15 minutes. The polymerization temperature at this time was adjusted to 60°C. Next, a hydrogenation operation similar to that performed for the production of block copolymer (1) was carried out to obtain block copolymer (20). The obtained block copolymer (20) had a styrene content of 15% by mass, polymer block (A) content of 70% by mass, polymer block (B) content of 0% by mass, polymer block (C) content of 30% by mass, vinyl bond content of the butadiene block portion before hydrogenation of 22.0 ml, weight-average molecular weight of 143,000, and hydrogenation rate of 60.0 ml.

[0102] (Block copolymer (21)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 50°C. Then, 0.055 parts by mass of Bu-Li and 0.3 moles of TMEDA per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor, and no NaOAm was added. As the first step, a cyclohexane solution (22% by mass) containing 30 parts by mass of styrene was added over 30 minutes, followed by a further 20 minutes of reaction. The polymerization temperature at this time was adjusted to 55°C. In the second step, a cyclohexane solution (22% by mass) containing 32 parts by mass of styrene and 58 parts by mass of butadiene was continuously added to the reactor over 30 minutes, and then the reaction was allowed to proceed for another 15 minutes. The polymerization temperature at this time was adjusted to 60°C. In the third step, a cyclohexane solution (22% by mass) containing 30 parts by mass of styrene was added over 40 minutes, followed by a further 20 minutes of reaction. The polymerization temperature was adjusted to 62°C during this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 1.5 hours at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (21). The block copolymer (21) obtained as described above had a styrene content of 92% by mass, a polymer block (A) content of 40% by mass, a polymer block (B) content of 60% by mass, a vinyl bond content of 14 mol% in the block copolymer, a weight-average molecular weight of 24,000, and a hydrogenation rate of 73 mol%. The physical properties of block copolymer (21) (referred to as copolymer (21) in the table) are shown in Table 1.

[0103] (Block copolymer (22)) (BAB) Batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 50°C. Then, 0.092 parts by mass of Bu-Li and 0.70 moles of TMEDA per mole of Bu-Li were added to 100 parts by mass of the total monomer added to the reactor, and NaOAm was not added. As the first step, a cyclohexane solution (22% by mass) containing 12 parts by mass of styrene was added over 20 minutes, followed by a further 10 minutes of reaction. The polymerization temperature at this time was adjusted to 65°C. In the second step, a cyclohexane solution (22% by mass) containing 6 parts by mass of styrene and 78 parts by mass of butadiene was continuously added to the reactor over 70 minutes, followed by a reaction over 15 minutes. The polymerization temperature at this time was adjusted to 68°C. In the third step, a cyclohexane solution (22% by mass) containing 13 parts by mass of styrene was added over 20 minutes, followed by a further 10 minutes of reaction. The polymerization temperature was adjusted to 70°C during this time. Methanol was then added to stop the polymerization reaction. Furthermore, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer at a concentration of 100 ppm (Ti-based) per 100 parts by mass of the block copolymer, and the hydrogenation reaction was carried out for approximately 2 hours at a hydrogen pressure of 0.7 MPa and a temperature of 65°C. Next, 0.3 parts by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to 100 parts by mass of the block copolymer to obtain the hydrogenated block copolymer (22). The block copolymer (22) obtained as described above had a styrene content of 31% by mass, a polymer block (A) content of 75% by mass, a polymer block (B) content of 25% by mass, a vinyl bond content of 11 mol% in the block copolymer, a weight-average molecular weight of 300,000, a molecular weight distribution of 1.07, and a hydrogenation rate of 98 mol%. The physical properties of block copolymer (22) (referred to as copolymer (22) in the table) are shown in Table 1.

[0104] (Block copolymer (23)) (CBAB) Similar to the synthesis of the block copolymer (1) described above, batch polymerization was carried out using a stirring device with an internal volume of 10 L and a jacketed tank reactor in the following manner. First, 1 L of cyclohexane was added to the reactor, and the temperature was adjusted to 58°C. Then, 0.085 parts by mass of Bu-Li, 1.2 moles of TMEDA per mole of Bu-Li, and 0.07 moles of NaOAm per mole of Bu-Li were added to 100 parts by mass of total monomer. Next, as the first step, a cyclohexane solution (25% by mass) containing 20 parts by mass of butadiene was added over 10 minutes, and the reaction was then allowed to continue for another 10 minutes. The polymerization temperature at this time was adjusted to 58°C. Next, as the second step, a cyclohexane solution (24% by mass) containing 30 parts by mass of styrene was added over 30 minutes, and the reaction was continued for another 15 minutes. The polymerization temperature at this time was adjusted to 60°C. Next, as the third step, a cyclohexane solution (monomer concentration 24% by mass) containing 10 parts by mass of styrene and 70 parts by mass of butadiene was continuously added to the reactor at a constant rate over 60 minutes, and then the reaction was allowed to continue for another 15 minutes. The polymerization temperature at this time was adjusted to 65°C. Next, in the fourth step, a cyclohexane solution (24% by mass) containing 30 parts by mass of styrene was added over 30 minutes, followed by a further 10 minutes of reaction. The polymerization temperature at this time was adjusted to 70°C. Next, a hydrogenation operation similar to that used to produce block copolymer (1) was carried out for approximately 2 hours to obtain block copolymer (23). The obtained block copolymer (23) had a styrene content of 68% by mass, polymer block (A) content of 20% by mass, polymer block (B) content of 60% by mass, polymer block (C) content of 20% by mass, vinyl bond content in the block copolymer of 73.0 mol%, weight-average molecular weight of 224,000, and hydrogenation rate of 98 mol%.

[0105] The block structures, polymer block content, and physical properties of the block copolymers (1) to (23) described above are shown in Table 1 below.

[0106] [Table 1]

[0107] [Examples 1-36], [Comparative Examples 1-20] A resin composition was prepared using the following components according to the following preparation method. The component ratios and physical properties are shown in the table below.

[0108] (Component (I): Block copolymer) Copolymers (1) to (23) in Table 1, as well as the following commercially available polymers, were used. Styrene-butadiene block copolymer (TR2630, manufactured by JSR Corporation) Polymethyl methacrylate (Tg: 90℃, manufactured by Tokyo Chemical Industry Co., Ltd.) Polylactic acid REVODE110 (Tg: 62℃, Kobe Seika Co., Ltd.)

[0109] (Component (II): Bismaleimide compound) BMI-2300 (manufactured by Yamato Kasei Co., Ltd.) Bis(3-ethyl-5-methyl-4-maleimidophenyl)methane (BMI-70) (manufactured by K.I. Chemicals Co., Ltd.) 4,4'-Bismaleimidediphenylmethane (BMI) (manufactured by K.I. Chemicals Co., Ltd.)

[0110] (Component (III): Cyanate ester compound) Cyanate ester compound 2,2-bis(4-cyanatephenyl)propane (manufactured by Tokyo Chemical Industry Co., Ltd.) Naphthol aralkyl type cyanate ester (Mw:600) prepared based on the synthesis example described in Japanese Patent Publication No. 2019-552299.

[0111] (Component (IV): Polyphenylene ether resin) OPE-2St (manufactured by Mitsubishi Gas Chemical Company)

[0112] (Component (V): Other) Silica: SC-2050MB (manufactured by Admatex Co., Ltd.) Compatibilizer: Crystalex 3085 (manufactured by East Chemical Co., Ltd.) Compatibilizer: M1913 (manufactured by Asahi Kasei Corporation) Curing accelerator: Zinc 2-ethylhexanoate (manufactured by Tokyo Chemical Industry Co., Ltd.) Radical initiator: Permil D

[0113] [Manufacturing of resin compositions] Resin compositions were prepared using the mixing ratios shown in the table below. Toluene, methyl ethyl ketone, and methyl isobutyl ketone were used as solvents. First, the bismaleimide compound and cyanate ester compound components were dissolved at 160°C and reacted with stirring for 6 hours to obtain bismaleimide triazine resin. The obtained bismaleimide triazine resin was dissolved in toluene, the remaining components were added, and the mixture was stirred and dissolved to prepare a varnish with a concentration of 20% to 50% by mass. The varnish was applied to a release-treated Kapton film at a speed of 30 mm / second, and then dried in a forced-air dryer under a nitrogen stream at 100°C for 30 minutes to obtain the film. The obtained film was cured in a forced-air dryer under a nitrogen atmosphere at 200°C for a maximum of 90 minutes to obtain a cured film. The cured film was used as an evaluation sample.

[0114] [Manufacturing of copper-clad laminates] The varnish obtained in the above [production of resin composition] was impregnated onto a low-dielectric glass cloth with a thickness of 0.069 mm, and heated and dried at 165°C for 5 minutes using a dryer (pressure-resistant explosion-proof steam dryer, manufactured by Takasugi Seisakusho Co., Ltd.) to obtain a prepreg with a resin composition content of 30% by mass. Two sheets of this prepreg are stacked, and 12μm copper foil (3EC-M3-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) is placed on both sides, and a pressure of 30 kg / cm² is applied. 2 Then, a vacuum press was performed at a temperature of 210°C for 150 minutes to obtain a copper-clad laminate (metal foil-clad laminate) with a thickness of 0.2 mm.

[0115] [Methods for measuring and evaluating the properties of resin compositions] ((1) Dielectric loss tangent and dielectric properties) The dielectric loss tangent at 10 GHz was measured using the cavity resonance method. A network analyzer (N5230A, manufactured by Agilent Technologies) and a cavity resonator (Cavity Resornator CP series) manufactured by Kanto Electronics Applied Development Co., Ltd. were used as measurement devices. The measurement sample was a 2.6 mm wide x 80 mm long test piece cut from the cured film obtained in the above [manufacturing of resin composition] and measured. The dielectric constant (Dk) and dielectric loss tangent (Df) were evaluated as follows.

[0116] <Examples 1-21, Comparative Examples 1-10> Dielectric constant (Dk): "A" Less than 3.30 "B" 3.30 or higher and less than 3.50 "C" 3.50 or higher and less than 3.70 "D" 3.70 or higher Dielectric loss tangent (Df): "A" less than 0.0046 "B" 0.0046 or higher and less than 0.0051 "C" 0.0051 or higher and less than 0.0056 "D" 0.0056 or more

[0117] <Examples 22-23, Comparative Example 11> Dielectric constant (Dk): "A" Less than 2.50 "B" 2.50 or higher and less than 2.70 "C" 2.70 or higher Dielectric loss tangent (Df): "A" Less than 0.0035 "B" 0.0035 or higher and less than 0.0040 "C" 0.0040 or more

[0118] <Examples 24-36, Comparative Examples 12-20> Dielectric constant (Dk): "A" Less than 2.30 "B" 2.30 or higher and less than 2.40 "C" 2.40 or higher and less than 2.50 "D" 2.50 or more Dielectric loss tangent (Df): "A" Less than 0.0020 "B" 0.0020 or higher and less than 0.0025 "C" 0.0025 or higher and less than 0.0030 "D" 0.0030 or more

[0119] ((2) Drillability) Two copper-clad laminates prepared in the above (manufacturing of copper-clad laminates) were stacked, with a 0.1 mm thick aluminum foil placed on top and a 1.5 mm thick paper-based phenolic resin laminate (Futamura Chemical Co., Ltd., FL-101) placed underneath. Using a 0.2 mm diameter drill (Hitachi Via Mechanics Co., Ltd., ND-1V212), five via holes were created at arbitrary locations under the conditions of rotation speed: 160 krpm, feed rate: 2 m / min, and chip load: 12.5 μm / rev. The drilling performance was evaluated by SEM observation. The evaluation methods are as follows (a) and (b).

[0120] <(a) Presence or absence of cracks> We observed from SEM images whether cracks had formed at the bottom of the five via holes. We assumed that materials with fewer cracks had better drilling performance, and evaluated them as follows. ○: No cracks △: Although some cracks remain, the number of cracks has decreased compared to the comparative example without the addition of component (I). ×: Cracks were present, and the number of cracks was equivalent to or greater than that of the comparative example without the addition of component (I).

[0121] <(b) Maximum smear length> The maximum length of smear flowing from the circumference to the center of the bottom surface of the via hole (maximum smear length) was measured from the obtained SEM images, and the average of the maximum smear lengths of five via holes was calculated. The values ​​were evaluated as follows: ○: Maximum smear length is less than 4 μm △: The maximum smear length is 4 μm or more and less than 6 μm ×: The maximum smear length is 6 μm or more

[0122] ((3) Compatibility of the copolymer) The varnish and film described above were visually confirmed, and the compatibility of the copolymer was evaluated as follows. For the comparative example in which the component (I) was not added, “-” was described. 〇: There was no insoluble matter or gel generation in the varnish, and no separation occurred on the liquid surface. The appearance of the film was uniform. ×: Insoluble matter or gel generation or separation of the liquid surface occurred in the varnish. The appearance of the film was not uniform.

[0123] ((4) Flexural strength) Using the cured film with a thickness of 0.6 mm described above, in accordance with JIS K6911, an autograph testing machine was used. Both end portions of the test piece were supported by fulcrums to form a simply supported beam, and the maximum flexural stress when a concentrated load was applied from above to the central portion was measured to obtain the flexural strength. The value is shown when the flexural strength of Comparative Example 1 without the block copolymer and / or copolymer was set to 100. The larger the value, the more the flexural strength is improved.

[0124] <N

Table 2

[0125]

Table 3

[0126]

Table 4

[0127]

Table 5

[0128]

Table 6

[0129]

Table 7

[0130]

Table 8

[0131]

Table 9

[0132]

Table 10

[0133]

Table 11

[0134]

Table 12

Industrial Applicability

[0135] The resin composition of the present invention has industrial applicability as an electronic circuit board and a next-generation communication substrate excellent in dielectric properties, heat resistance, and strength.

Claims

1. A resin composition comprising the components (I), (II), and (III) shown below. Component (I): A block copolymer comprising conjugated diene monomer units and vinyl aromatic monomer units, A random polymer block (A) comprising the conjugated diene monomer unit and the vinyl aromatic monomer unit, A polymer block (B) having a content of vinyl aromatic monomer units exceeding 95% by mass when the entire polymer block (B) is considered to be 100% by mass, and / or a polymer block (C) having a content of conjugated diene monomer units exceeding 95% by mass when the entire polymer block (C) is considered to be 100% by mass. The random polymer block (A) is contained in an amount of 30 to 85% by mass per 100% by mass of the block copolymer. A block copolymer in which the tanδ peak of the block copolymer, obtained by dynamic viscoelasticity measurement (1 Hz), is in the range of -30°C to 60°C. Component (II): Bismaleimide compound. Component (III): Cyanate ester compound.

2. Of the 100% by mass of the block copolymer of component (I), the content of the polymer block (B) is 3% by mass to 55% by mass. The resin composition according to claim 1.

3. Of the 100% by mass of the block copolymer of component (I), the content of vinyl aromatic monomer units is 30% by mass to 90% by mass. The resin composition according to claim 1 or 2.

4. The amount of vinyl bond is 15 to 90 mol% relative to the total 100 mol% of conjugated diene monomer units contained in the block copolymer of component (I). The resin composition according to claim 1 or 2.

5. The hydrogenation rate of the double bonds of the conjugated diene monomer units contained in the block copolymer of component (I) is 15 mol% or more. The resin composition according to claim 1 or 2.

6. The weight-average molecular weight (Mw) of the block copolymer of component (I) is between 30,000 and 500,000. The resin composition according to claim 1 or 2.

7. The content of component (I) is 5 to 50 parts by mass per 100 parts by mass of resin solids in the resin composition. The resin composition according to claim 1 or 2.

8. A cured product of the resin composition according to claim 1 or 2.

9. An electronic circuit board material comprising the cured product described in claim 8.

10. A resin film comprising the cured product described in claim 8.

11. Substrate and The resin composition according to claim 1 or 2, A prepreg is a composite of two elements.

12. Substrate and The cured product according to claim 8, A prepreg is a composite of two elements.

13. The aforementioned substrate is glass cloth. The prepreg according to claim 11.

14. The aforementioned substrate is glass cloth. The prepreg according to claim 12.

15. A cured resin film according to claim 10, Metal foil and A laminate having the following properties.

16. A cured prepreg according to claim 11, Metal foil and A laminate having the following properties.

17. A cured prepreg according to claim 12, Metal foil and A laminate having the following properties.

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