TWI908014B - Resin compounds, hardeners, resin films, prepregs, laminates, and printed wiring boards - Google Patents

Abstract

This invention provides a resin composition that yields a cured product with low dielectric constant, low dielectric loss factor, and excellent heat resistance. The resin composition of this invention comprises: copolymer (A) and copolymer (B) having vinyl aromatic monomer units and conjugated diene monomer units, and one or more of (I) to (III); and the resin composition satisfies the following conditions: (I): Curing resin (excluding copolymers (A) and (B)) (II): Free radical initiator (III): Curing agent (excluding component (I)) The Mn of copolymer (A) is 40,000 or less. Copolymers (A) and (B) have one or more polymer blocks with vinyl aromatic monomer units as the main component. The Mn of copolymer (B) is 80,000 or more. The difference in content (BS) between copolymers (A) and (B) of polymer blocks with vinyl aromatic monomers as the main component, ΔBS, is 20% by mass or less. The average content of vinyl aromatic monomers in copolymers (A) and (B) is 40% by mass or less. The BSb content of copolymer (B) is 10% by mass or more.

Description

Resin compounds, hardeners, resin films, prepregs, laminates, and printed circuit boards

This invention relates to a resin composition, a hardener, a resin film, a prepreg, a laminate, and a printed wiring board.

In recent years, with the significant advancements in information network technology and the expansion of services utilizing information networks, electronic devices are facing demands for larger data capacities and higher processing speeds. To meet these requirements, materials for various substrates, such as printed circuit boards (PCBs) and flexible substrates, are required to have low dielectric loss.

Previously, to obtain materials with lower dielectric loss, research and disclosure have revealed thermosetting resins such as epoxy resins with low dielectric constant and low dielectric loss factor, and excellent mechanical properties such as strength and heat resistance, or resin curing products with thermoplastic resins such as polyphenylene ether as the main component. However, from the perspective of low dielectric constant and low dielectric loss factor, the previously disclosed materials still have room for improvement. When used in printed circuit boards, they present limitations in information capacity and processing speed.

To address this problem, various rubber components have been previously proposed as modifiers for the thermosetting or thermoplastic resins described above. For example, Patent 1 discloses an elastomer selected from the group consisting of block copolymers of vinyl aromatic compounds and olefinic olefins and their hydroxides, and homopolymers of vinyl aromatic compounds, as a modifier for reducing the dielectric loss factor and dielectric constant of polyphenylene ether resins. Furthermore, Patent 2 discloses a styrene-based elastomer as a modifier for reducing the dielectric loss factor and dielectric constant of epoxy resins. [Prior Art Documents] [Patent Documents]

[Patent Document 1] Japanese Patent Application Publication No. 2021-147486 [Patent Document 2] Japanese Patent Application Publication No. 2020-15861

However, resin compositions using the modifiers disclosed in Patents 1 and 2 have the following problems: the reduction of dielectric constant and dielectric loss factor is still insufficient, and the addition of the modifier leads to a decrease in heat resistance. Furthermore, the styrene-based elastomers previously used as modifiers have limitations in their addition amount due to insufficient solubility in varnishes.

Therefore, the purpose of this invention is to provide a resin composition capable of producing a hardened material with low dielectric constant and low dielectric loss factor and excellent heat resistance, a hardened material using the above resin composition, a resin film, a prepreg, a laminate, and a printed circuit board. [Technical Means for Solving the Problem]

Through repeated and in-depth research to solve the problems of the prior art, it was discovered that the above-mentioned problems can be solved by a resin composition containing the following substances, thereby completing the present invention: copolymer (A) and copolymer (B) having a defined structure as copolymers of vinyl aromatic compounds and conjugated diene compounds; and at least one of a curing resin, a free radical initiator, and a curing agent. That is, the present invention is as follows.

[1] A resin composition comprising: a copolymer (A) having vinyl aromatic monomer units and conjugated diene monomer units, a copolymer (B) having vinyl aromatic monomer units and conjugated diene monomer units, and at least one component selected from the group consisting of components (I) to (III) below, and the resin composition satisfies the following <condition (1)> to <condition (7)>. Component (I): Curing resin (excluding copolymer (A) and copolymer (B)) Component (II): Free radical initiator Component (III): Curing agent (excluding component (I)) <condition (1)>: The number average molecular weight of the above copolymer (A) is 40,000 or less. <Condition (2)>: The copolymer (A) has at least one polymer block primarily composed of vinyl aromatic monomers. <Condition (3)>: The copolymer (B) has at least one polymer block primarily composed of vinyl aromatic monomers. <Condition (4)>: The number average molecular weight of the copolymer (B) is 80,000 or more. <Condition (5)>: The difference (ΔBS) between the content (BSa) (mass %) of the polymer block primarily composed of vinyl aromatic monomers in the copolymer (A) and the content (BSb) (mass %) of the polymer block primarily composed of vinyl aromatic monomers in the copolymer (B) satisfies the following relationship. ΔBS＝｜BSa―BSb｜≦20 ＜Condition (6)＞： The average content of vinyl aromatic monomer units in the above copolymers (A) and (B) is 40% by mass or less. ＜Condition (7)＞： The content (BSb) of polymer blocks in the above copolymer (B) with vinyl aromatic monomer units as the main component is 10% by mass or more. [2] In the resin composition described in [1] above, the average hydrogenation rate (H)(%) and average vinyl bond content (V)(%) of the unsaturated double bonds from conjugated diene compounds contained in the above copolymers (A) and (B) satisfy the following relationship. V＋10≦H [3] The resin composition described in [1] or [2] above, wherein the copolymer (B) is a block copolymer with the general structure represented by a1-b1-a2-c1, a1-b1-a2-b2, a1-c1-a2-c2, a1-c1-a2-b1, blocks a1 and a2 are polymer blocks with vinyl aromatic monomers as the main body, blocks b1 and b2 are random polymer blocks containing vinyl aromatic monomers and conjugated diene monomers, blocks c1 and c2 are polymer blocks with conjugated diene monomers as the main body. [4] A resin composition as described in any of [1] to [3] above, wherein the ratio (Mnb/Mna) of the number average molecular weight (Mnb) of the copolymer (B) to the number average molecular weight (Mna) of the copolymer (A) is greater than 4. [5] A resin composition as described in any of [1] to [4] above, wherein the copolymer (A) is a block copolymer represented by the general structural formula: d-f, d is a polymer block with a vinyl aromatic monomer as the main component, f is a polymer block with a conjugated diene monomer as the main component. [6] A cured material, which is a cured product of a resin composition as described in any of [1] to [5] above. [7] A printed wiring board comprising the cured material as described in [6] above. [8] A resin film comprising the curing agent as described in [6] above. [9] A prepreg, which is a composite of a substrate and a resin composition as described in any one of [1] to [5] above. [10] A prepreg, which is a composite of a substrate and the curing agent as described in [6] above. [11] A prepreg as described in [9] above, wherein the substrate is glass cloth. [12] A prepreg as described in [10] above, wherein the substrate is glass cloth. [13] A laminate comprising: a curing agent of the resin film as described in [8] above, and a metal foil. [14] A laminate comprising: a cured prepreg as described in [9] above, and a metal foil. [15] A laminate comprising: a cured prepreg as described in [10] above, and a metal foil. [16] A printed wiring board comprising a resin film as described in [8] above. [17] A printed wiring board comprising a prepreg as described in [11] above. [18] A printed wiring board comprising a prepreg as described in [12] above. [Effects of the Invention]

According to the present invention, a resin composition capable of producing a hardened material with low dielectric constant, low dielectric loss factor and excellent heat resistance, a hardened material using the above resin composition, a resin film, a prepreg, a laminate, and a printed circuit board can be obtained.

The following provides a detailed description of the forms used to implement this invention (hereinafter referred to as "this embodiment"). Furthermore, the following embodiments are illustrative of the invention and are not intended to limit the invention to these contents. The invention can be implemented with various variations within the scope of its intent.

[Resin Composition] The resin composition of this embodiment contains: a copolymer (A) having vinyl aromatic monomer units and conjugated diene monomer units, a copolymer (B) having vinyl aromatic monomer units and conjugated diene monomer units, and at least one component selected from the group consisting of components (I) to (III) below, and the resin composition satisfies the following <Condition (1)> to <Condition (7)>. Component (I): Curing resin (excluding copolymer (A) and copolymer (B)) Component (II): Free radical initiator Component (III): Curing agent (excluding component (I)) <Condition (1)>: The number average molecular weight of the above copolymer (A) is 40,000 or less. <Condition (2)>: The copolymer (A) has at least one polymer block primarily composed of vinyl aromatic monomers. <Condition (3)>: The copolymer (B) has at least one polymer block primarily composed of vinyl aromatic monomers. <Condition (4)>: The number average molecular weight of the copolymer (B) is 80,000 or more. <Condition (5)>: The difference (ΔBS) between the content (BSa) (mass %) of the polymer block primarily composed of vinyl aromatic monomers in the copolymer (A) and the content (BSb) (mass %) of the polymer block primarily composed of vinyl aromatic monomers in the copolymer (B) satisfies the following relationship. ΔBS＝｜BSa―BSb｜≦20 ＜Condition (6)＞： The average content of vinyl aromatic monomer units in the above copolymers (A) and (B) is 40% by mass or less. ＜Condition (7)＞： The content (BSb) of polymer blocks in the above copolymer (B) with vinyl aromatic monomer units as the main component is 10% by mass or more.

The resin composition of this embodiment, by possessing the above-described structure, yields a cured product with low dielectric constant, low dielectric loss factor, and excellent heat resistance. Furthermore, in this specification, when a polymeric monomer is incorporated into the constituent elements of a polymer, it is referred to as a "monomer unit," and when it exists in its monomeric state before becoming a constituent element of the polymer, it is referred to as a "compound."

(Copolymer (A)) The resin composition of this embodiment contains copolymer (A). Copolymer (A) is a copolymer having vinyl aromatic monomer units and conjugated diene monomer units. The hydrogenated copolymer (A) has a number average molecular weight (Mna) of 40,000 or less and has at least one polymer block with a vinyl aromatic monomer unit as the main component.

<Vinyl Aromatic Compounds> Vinyl aromatic compounds that form vinyl aromatic monomers in copolymer (A) 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. Of these, styrene, α-methylstyrene, and p-methylstyrene are preferred from the viewpoint of availability and productivity. One of these compounds may be used alone, or two or more may be used in combination.

<Conjugated Diene Compounds> The conjugated diene compound that forms the conjugated diene monomer unit of copolymer (A) can be any diene hydrocarbon having conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, farnesene, etc., but is not limited to these. Of these, 1,3-butadiene and isoprene are preferred from the viewpoint of availability and productivity. One of these compounds may be used alone, or two or more may be used in combination.

<Condition (1)> The number average molecular weight (Mna) of copolymer (A) is 40,000 or less, preferably 5,000 or more but less than 40,000, and more preferably 5,000 or more but less than 35,000. By making the number average molecular weight (Mna) of copolymer (A) 40,000 or less, copolymer (A) tends to have good solubility relative to varnish. The number average molecular weight (Mna) of copolymer (A) can be determined by gel permeation chromatography (hereinafter referred to as GPC) using standard polystyrene as a calibration curve. Specifically, it can be determined by the method described in the following embodiments. The number average molecular weight (Mna) of copolymer (A) can be controlled within the aforementioned range by adjusting conditions such as the amount of monomer added and the amount of polymerization initiator added during the polymerization process.

In this specification, "vinyl bond amount" refers to the ratio of 1,2-bonds and 3,4-bonds in the unhydrogenated conjugated diene. The vinyl bond amount can be determined by nuclear magnetic resonance spectroscopy (NMR). The vinyl bond amount can be arbitrarily controlled by using the polar compounds described below.

<Condition (2)> The copolymer (A) has at least one polymer block primarily composed of a vinyl aromatic monomer. By having at least one polymer block primarily composed of a vinyl aromatic monomer, the copolymer (A) tends to exhibit increased solubility relative to varnishes.

Furthermore, in this specification, "as the main component" refers to the presence of 95% to 100% by mass of the target monomer unit in the polymer blocks of the target. The copolymer (A) preferably has a polymer block content (BAa) of 5-37% by mass, more preferably 7-35% by mass, and even more preferably 10-32% by mass. By ensuring that the copolymer (A) has a polymer block content (BSa) of 5% by mass or more of vinyl aromatic monomer units, there is a tendency for the copolymer (A) to have increased solubility relative to varnishes. The content of the polymer block content of vinyl aromatic monomer units can be determined by NMR. Specifically, it can be determined by the method described in the following embodiments. The content (BSa) of polymer blocks in copolymer (A) with vinyl aromatic monomers as the main component can be controlled within the above-mentioned value range by adjusting the amount of monomer added, the timing of addition, and the polymerization time in the polymerization steps.

The structure of copolymer (A) is not limited, but it is preferred to have a structure represented by the following general formula: de df (de) _n (df) _n ded dfd ef def dfe (de) _m -Z (df) _m -Z (def) _m -Z (dfe) _m -Z In the above formula, d, e, and f represent polymer blocks (d), (e), and (f), respectively. From a production point of view, (de) _n and (df) _n are preferred, and more preferably de and df. Furthermore, from the viewpoint of the crack resistance of the resin composition of this embodiment, copolymer (A) is more preferably df. When copolymer (A) is df, there is a tendency for the toughness of the resin composition of this embodiment to be improved, and there is a tendency for the crack resistance to become better. Furthermore, copolymer (A) may also be a mixture containing, in any proportion, the structures represented by the above general formula in multiple types.

In the above general formulas representing copolymers (A), d represents a polymer block with a vinyl aromatic monomer as the main component, e represents a polymer block with a conjugated diene monomer as the main component, and f represents a random copolymer block comprising both vinyl aromatic monomers and conjugated diene monomers. n is an integer of 1 or more, preferably an integer from 1 to 10, and more preferably an integer from 1 to 5. m is an integer of 2 or more, preferably an integer from 2 to 11, and more preferably an integer from 2 to 8. Z represents the coupling agent residue. Here, the coupling agent residue refers to the residue remaining after bonding by the coupling agent used for bonding between polymer blocks (e) and between polymer blocks (f). Examples of coupling agents include, but are not limited to, the following polyhalogen compounds or esters.

The vinyl aromatic monomer units in the polymer block (f) can be uniformly distributed or tapered. Furthermore, the vinyl aromatic monomer units can exist in multiple uniformly distributed portions and/or tapered portions. Moreover, the polymer block (f) described above can also contain multiple portions with varying amounts of vinyl aromatic monomer units.

(Copolymer (B)) Copolymer (B) is a copolymer comprising vinyl aromatic monomer units and conjugated diene monomer units. Copolymer (B) has at least one polymer block with a vinyl aromatic monomer unit as the main component, a number average molecular weight (Mnb) of 80,000 or more, and a content (BSb) of the polymer block with a vinyl aromatic monomer unit as the main component of 10% by mass or more.

<Vinyl Aromatic Compounds> Vinyl aromatic compounds that form vinyl aromatic monomer units of the copolymer (B) 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. Of these, styrene, α-methylstyrene, and p-methylstyrene are preferred from the viewpoint of availability and productivity. One of these compounds may be used alone, or two or more may be used in combination.

<Conjugated Diene Compounds> The conjugated diene compound that forms the conjugated diene monomer unit of the copolymer (B) can be any diene hydrocarbon having conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, farnesene, etc., but is not limited to these. Of these, 1,3-butadiene and isoprene are preferred from the viewpoint of availability and productivity. One of these compounds may be used alone, or two or more may be used in combination.

The copolymer (B) has at least one polymer block primarily composed of a vinyl aromatic monomer. When the copolymer (B) has a polymer block primarily composed of a vinyl aromatic monomer, there is a tendency for the copolymer (B) to exhibit increased solubility relative to the varnish.

In copolymer (B), the content (BSb) of polymer blocks with vinyl aromatic monomers as the main component is 10% by mass or more, preferably 13% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more. By ensuring that the content (BSb) of polymer blocks with vinyl aromatic monomers as the main component in copolymer (B) is 10% by mass or more, the solubility of copolymer (B) relative to varnish is improved, and the degree of freedom in setting the formulation amount of copolymer (B) in the resin composition of this embodiment is increased. The content of polymer blocks with vinyl aromatic monomers as the main component can be determined by NMR. Specifically, it can be determined by the method described in the following embodiments. The content (BSb) of polymer blocks in copolymer (B) with vinyl aromatic monomers as the main component can be controlled within the above-mentioned value range by adjusting the amount of monomer added, the timing of addition, and the polymerization time in the polymerization steps.

The number average molecular weight (Mnb) of copolymer (B) is 80,000 or more, preferably 100,000 or more, more preferably 120,000 or more, and even more preferably 150,000 or more. By including copolymer (A) and copolymer (B) in the resin composition of this embodiment, there is a tendency to improve the low dielectric constant and low dielectric loss factor of the resin composition of this embodiment. On the other hand, regarding heat resistance, component (I): the cured resin is higher than copolymers (A) and (B). By setting the number average molecular weight (Mnb) of copolymer (B) to 80,000 or more, the decrease in heat resistance of the resin composition caused by the addition of copolymers (A) and copolymers (B) can be suppressed, ensuring the excellent heat resistance of the resin composition of this embodiment. From a productivity standpoint, the upper limit of the number average molecular weight (Mnb) of copolymer (B) is preferably below 700,000, more preferably below 500,000, and further preferably below 300,000. The number average molecular weight (Mnb) of copolymer (B) can be determined by GPC. The number average molecular weight (Mnb) of copolymer (B) can be controlled within the above-mentioned range by adjusting conditions such as the amount of monomer added and the amount of polymerization initiator added in the polymerization steps.

The copolymer (B) is not limited to the following, but preferably has a structure represented by the following general formula. (a1-b1) _o (a1-c1) _o a1-b1-a2 a1-c1-a2 a1-b1-c1 a1-c1-b1 a1-b1-c1-a2 a1-c1-b1-a2 a1-b1-c1-b2 a1-c1-b1-c2 a1-b1-a2-b2 a1-b1-a2-c1 a1-c1-a2-c2 a1-c1-a2-b1 [(a1-b1) _o ] _p -Z [(a1-c1) _o ] _p -Z (a1-b1-c1) _p -Z (a1-c1-b1) _p -Z

The copolymer (B) is preferably a block copolymer with the structure represented by the general formulas a1-b1-a2-b2, a1-b1-a2-c1, a1-c1-a2-b1, and a1-c1-a2-c2, and more preferably a1-b1-a2-c1. When the copolymer (B) is a block copolymer with the structure represented by the general formulas a1-b1-a2-b2, a1-b1-a2-c1, a1-c1-a2-b1, and a1-c1-a2-c2, the resin composition of this embodiment tends to have excellent copper adhesion. In the above general formulas, a1, a2, b1, b2, c1, and c2 represent polymer blocks (a1), (a2), (b1), (b2), (c1), and (c2), respectively. o is an integer greater than or equal to 1, preferably an integer from 1 to 10, and more preferably an integer from 1 to 5. p is an integer greater than or equal to 2, preferably an integer from 2 to 11, and more preferably an integer from 2 to 8. Z represents the coupling agent residue. Here, the coupling agent residue refers to the residue remaining after bonding by the coupling agent used for bonding between polymer blocks (b1) and between polymer blocks (c1).

Copolymer (B) is preferably formed by successive polymerization. "Successive polymerization" means polymerization proceeding sequentially from one end of the final target polymer structure to the opposite end, without the use of coupling reactions. Successive polymerization allows for the production of polymers with asymmetrical structures, making it suitable for producing asymmetrical copolymers (B) such as a1-b1-a2-c1. However, when copolymers (B) are formed through coupling reactions, there is a possibility of uncoupled polymer residues, potentially resulting in copolymers (A) and (B) not being obtained as designed. Successive polymerization is preferable in that it is less likely to generate byproducts other than the target structure.

The vinyl aromatic monomer units in polymer block (b) can be uniformly distributed or tapered. Furthermore, the vinyl aromatic monomer units can exist in multiple uniformly distributed portions and/or tapered portions. Moreover, the polymer block (b) can also contain multiple portions with different amounts of vinyl aromatic monomer units.

In the above general formulas representing copolymer (B), (a1) and (a2) are polymer blocks with vinyl aromatic monomers as the main component. (b1) and (b2) are random copolymer blocks comprising vinyl aromatic monomers and conjugated diene monomers. (c1) and (c2) are polymer blocks with conjugated diene monomers as the main component.

(Relationship between the content of polymer blocks with vinyl aromatic monomers as the main component in copolymers (A) and (B)) In the resin composition of this embodiment, the difference (ΔBS) between the content (BSa) (mass %) of polymer blocks with vinyl aromatic monomers as the main component in copolymer (A) and the content (BSb) (mass %) of polymer blocks with vinyl aromatic monomers as the main component in copolymer (B) is satisfied with the following relationship: ΔBS = |BSa - BSb| ≤ 20 Furthermore, ΔBS is preferably less than 15, more preferably less than 10. When ΔBS satisfies the above relationship, the solubility of copolymers (A) and (B) relative to the varnish can be ensured. Due to its relatively high molecular weight, copolymer (B) may be difficult to dissolve in varnish on its own, depending on its molecular weight or structure. Setting a smaller ΔBS value can prevent this. This is believed to be because copolymer (A) has a low molecular weight and tends to have relatively high solubility in varnish. Therefore, by satisfying |BSa―BSb|≦20, the compatibility between copolymer (A) and copolymer (B) is improved, allowing copolymer (A) to act as a compatibilizer and help improve the solubility of copolymer (B) in varnish. ΔBS can be controlled within the above-mentioned value range by adjusting the amount of monomers added in the polymerization steps of copolymers (A) and (B), as well as the polymerization time.

(Relationship between the number average molecular weights of copolymers (A) and (B)) The ratio (Mnb/Mna) of the number average molecular weight (Mnb) of copolymer (B) to that of copolymer (A) is preferably greater than 4, more preferably 5 or greater, and even more preferably 6 or greater. When (Mnb/Mna) is greater than 4, the resin composition of this embodiment tends to have excellent heat resistance.

(Average content of vinyl aromatic monomer units in copolymer (A) and copolymer (B)) The average content of vinyl aromatic monomer units in copolymer (A) and copolymer (B) is 40% by mass or less, preferably 10% to 40% by mass, more preferably 13% to 40% by mass, even more preferably 17% to 40% by mass, and even more preferably 17% to 36% by mass. If the average content of vinyl aromatic monomer units in copolymer (A) and copolymer (B) is 40% by mass or less, the resin composition of this embodiment tends to exhibit good dielectric properties. The content of vinyl aromatic monomer units in copolymer (A) and copolymer (B) may be the same or different. In different situations, the content of vinyl aromatic monomers in both copolymers (A and B) should be set such that the average content is 40% by mass or less. The content of vinyl aromatic monomers in both polymers should also be set such that the weighted average of the added molecular weight and mixing ratio is 40% by mass or less. From the perspective of improving the compatibility of the two copolymers, copolymers (A) and (B) have better content of vinyl aromatic monomers, vinyl bond amount, and hydrogenation rate with smaller differences. The average content of vinyl aromatic monomers in copolymers (A) and (B) can be controlled within the above-mentioned range by adjusting the amount of monomers added in the polymerization steps of copolymers (A) and (B).

(Average Vinyl Bond Content of Copolymers (A) and (B)) The average vinyl bond content (V) of the conjugated diene monomer units of copolymers (A) and (B) is preferably 20% or more, more preferably 30% or more, and even more preferably 40% or more. If the average vinyl bond content (V) in the conjugated diene monomer units of copolymers (A) and (B) is 20% or more, there is a tendency for improved copper adhesion of the resin composition of this embodiment.

The average vinyl bond content (V) in the conjugated diene monomer units of copolymers (A) and (B) is preferably 85% or less, more preferably 75% or less, and further preferably 65% or less. If the average vinyl bond content (V) in the conjugated diene monomer units of copolymers (A) and (B) is 85% or less, the resin composition of this embodiment tends to exhibit excellent long-term storage stability. The vinyl bond content of copolymers (A) and (B) may be the same or different. In the case of different situations, the vinyl bond content of the two polymers should be set in a manner that results in the preferred vinyl bond content for the total copolymers (A) and (B).

(Average Vinyl Bond Content (V) and Average Hydrogenation Rate (H) of Copolymers (A) and (B)) From the perspective of the long-term stability of the varnish, copolymers (A) and (B) are preferably hydrogenated copolymers. Preferably, the average hydrogenation rate (H) (%) of the unsaturated double bonds of the conjugated diene compounds contained in the copolymers, and the average vinyl bond content (V) (%) in the conjugated diene monomer units contained in copolymers (A) and (B) satisfy the following relationship: V＋10≦H Here, the average hydrogenation rate (H) refers to the average hydrogenation rate of copolymers (A) and (B), which can be calculated from the results of NMR measurements using the following formula. Average hydrogenation rate (H) = (Hydrolysis rate of copolymer (A)) × (Mass ratio of copolymer (A)) + (Hydrolysis rate of copolymer (B)) × (Mass ratio of copolymer (B)) Average vinyl bond amount (V) is the average vinyl bond amount of copolymer (A) and copolymer (B), which can be determined by NMR and calculated using the following formula: Average vinyl bond amount (V) = (Vinyl bond amount of copolymer (A)) × (Mass ratio of copolymer (A)) + (Vinyl bond amount of copolymer (B)) × (Mass ratio of copolymer (B)) Compared to unsaturated bonds formed by the 1,4-addition of conjugated dienes, the hydrogenation reaction of vinyl bonds is more reactive. Therefore, when the average hydrogenation rate (H) of copolymers (A) and (B) satisfies the above formula, the double bonds of the vinyl bonds are substantially hydrogenated, thereby exhibiting excellent long-term stability of the resin composition of this embodiment.

The average hydrogenation rate (H) of copolymers (A) and (B) can be controlled, for example, by the amount of catalyst during hydrogenation, and the hydrogenation rate can be controlled, for example, by the amount of catalyst, hydrogen feed rate, pressure, and temperature during hydrogenation. The average hydrogenation rate (H) of copolymers (A) and (B) can be determined by nuclear magnetic resonance (NMR). The average vinyl bond quantity (V) of copolymers (A) and (B) can be controlled, for example, by the amount of tertiary amine or ether compound added, and by adjusting the polymerization temperature. The average vinyl bond quantity (V) of copolymers (A) and (B) can be determined by nuclear magnetic resonance (NMR).

When copolymers (A) and (B) have random copolymer blocks comprising vinyl aromatic monomers and conjugated diene monomers, the mass percentage (RS) of vinyl aromatic monomers in the random copolymer blocks is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less. When the mass percentage (RS) of vinyl aromatic monomers in the random copolymer blocks of copolymers (A) and (B) is 30% by mass or less, there is a tendency for excellent copper bonding properties in the copolymers having random copolymer blocks, resin compositions containing the aforementioned copolymers, and their cured forms.

(Relationship between the molecular weights of polymer blocks in copolymers (A) and (B) with vinyl aromatic monomers as the main component) The ratio (MnS1/MnS2) of the molecular weight (MnS1) of the polymer block in copolymer (A) with vinyl aromatic monomers as the main component to the molecular weight (MnS2) of the polymer block in copolymer (B) with vinyl aromatic monomers as the main component is preferably 0.9 or less, more preferably 0.8 or less, and even more preferably 0.7 or less. When (MnS1/MnS2) is 0.9 or less, the resin composition of this embodiment tends to have excellent copper adhesion. Furthermore, (MnS1) and (MnS2) can be controlled by adjusting the amount of monomer added during polymerization. MnS1 and MnS2 are calculated by the following method. MnS1＝Mn1×BS1 MnS2＝Mn2×BS2÷f •BS1: The content (mass %) of polymer blocks with vinyl aromatic monomers as the main component in the copolymer (A) as determined by proton nuclear magnetic resonance ( ^¹H -NMR). •BS2: The content (mass %) of polymer blocks with vinyl aromatic monomers as the main component in the copolymer (B) as determined by proton nuclear magnetic resonance ( ^¹H -NMR). •f: The branching degree (Mn1) and (Mn2) of copolymer (B) determined by the GPC-light scattering method of an adhesion meter can be determined by GPC using standard polystyrene as a calibration curve. (BS1) and (BS2) can be determined by NMR. (f) can be determined by the GPC-light scattering method of an adhesion meter. Furthermore, the specific measurement method will be explained below.

Taking the application of NMR as an example, where the vinyl aromatic compound is styrene and the conjugated diene compound is 1,3-butadiene, the method for determining the mass ratio (RS1) and (RS2) of vinyl aromatic monomer units in a random polymer block, and the content (BS1) and (BS2) of polymer blocks with vinyl aromatic monomer units as the main component, will be specifically explained. ^A 1H-NMR sample prepared by dissolving 30 mg of copolymer (A) and copolymer (B) separately in 1 g of deuterated chloroform is used. The content (BS) of polymer blocks with vinyl aromatic monomer units as the main component (in this case, styrene blocks) is determined based on the ratio of the cumulative chemical shift values of 6.9 ppm to 6.3 ppm to the total cumulative value. Styrene block strength (b-St strength) = (cumulative value of 6.9 ppm to 6.3 ppm) / 2 Random styrene strength (r-St strength) = (cumulative value of 7.5 ppm to 6.9 ppm) - 3 × (b-St) Ethylene-butene strength (EB strength) = total cumulative value - 3 × {(b-St strength) + (r-St strength)} / 8 Styrene block content (BS) = 104 × (b-St strength) / [104 × {(b-St strength) + (r-St strength)} + 56 × (EB strength)] Mass ratio of styrene in random polymer blocks (RS) = 104 × (r-St strength) / {104 × (r-St strength) + 56 × (EB strength)}

(Branching degree (f) of copolymer (B)) The branching degree (f) of copolymer (B) can be determined by the GPC-light scattering method using a viscosity analyzer. Using copolymer (B) as a sample, the GPC-light scattering method of a viscosity analyzer is performed. Based on standard polystyrene, the absolute molecular weight (M) is determined according to the results of the light scattering detector and the RI detector, and the intrinsic viscosity ([η]) is determined according to the results of the RI detector and the viscosity analyzer. Then, the intrinsic viscosity ([η] ₀ ) used as a reference is calculated by the following formula. [η] ₀ ＝a×M ^b a＝-0.788＋0.421×(content of vinyl aromatic monomer units in copolymer (B)) －0.342×(RS2)－0.197×(BS2) b＝1.601－0.081×(content of vinyl aromatic monomer units in copolymer (B)) ＋0.064×(RS2)＋0.039×(BS2) RS2: mass ratio of vinyl aromatic monomer units in the random polymer blocks of copolymer (B) BS2: content of polymer blocks in copolymer (B) with vinyl aromatic monomer units as the main component, determined by proton nuclear magnetic resonance ( ^1H -NMR) M: absolute molecular weight of copolymer (B) Then, the intrinsic viscosity of copolymer (B) ([η]) and the intrinsic viscosity as a reference ([η] ₀ The contraction factor g is calculated in the form of the ratio of η to η. Contraction factor (g) = [η]/[η] _0. Then, using the obtained contraction factor (g), the branch degree (f) defined as g = f/{(f+1)(f+2)} (f≧2) is calculated.

(Methods for manufacturing copolymer (A) and copolymer (B)) Examples of methods for manufacturing copolymer (A) and copolymer (B) include those described in Japanese Patent Publication Nos. 36-19286, 43-17979, 46-32415, 49-36957, 48-2423, 48-4106, 51-49567, and 59-166518, but are not limited to these methods.

Furthermore, as a method for manufacturing copolymer (A) and copolymer (B), the following methods can be cited: (1) performing solution polymerization on copolymer (A) and copolymer (B) separately, and mixing solutions containing polymers; (2) removing solvent and catalyst from copolymer (A) and copolymer (B) respectively, and then mixing them; (3) adding polymerization initiator in two stages during the polymerization reaction; (4) adding a polymer initiator in the polymerization reaction relative to the copolymer (A) and copolymer (B). (5) After polymerization, add an amount of modifier equivalent to the amount of active terminal reacting with the above-mentioned active terminal, or a protic reagent such as an alcohol acting as a polymerization terminator, to terminate the reaction of a portion of the active terminal; then, after polymerization, add a polymer initiator and monomer to the solution to terminate the reaction of all active terminals, but not limited to these methods. In the method described in (1) above, any of the following methods may also be used: a method of performing a hydrogenation reaction by mixing the polymerization solutions of copolymer (A) and copolymer (B) before hydrogenation, or a method of mixing the solutions after hydrogenating copolymer (A) and copolymer (B) separately. Furthermore, the mixing ratio of copolymer (A) and copolymer (B) can be controlled by adjusting the concentration and mixing amount of their respective polymerization solutions. In the method described in (3) above, the mixing ratio of copolymer (A) and copolymer (B) can be arbitrarily controlled by adjusting the feed rates of the vinyl aromatic compound and the conjugated diene compound, the amount of polymerization initiator added in the two stages, and the timing of the addition of the polymerization initiator in the second stage. In the method described in (4) above, the mixing ratio and structure of copolymer (A) and copolymer (B) can be arbitrarily controlled by adjusting the feed rates and feed composition of the vinyl aromatic compound and the conjugated diene compound, the amount and timing of the modifier or polymerization terminator added midway. Copolymer (A) is a low molecular weight compound with relatively small molecular entanglement. Therefore, methods such as (1), (3), (4), and (5) described above, which involve mixing before solvent removal, allow for high-speed solvent removal and final processing. Methods (3) and (4) above can simultaneously produce copolymer (A) and copolymer (B), reducing production steps compared to producing copolymer (A) and copolymer (B) separately, thus improving production efficiency.

When using a tank reactor equipped with a stirring device and a jacket to batch polymerize a copolymer of styrene and butadiene, if the block structure of copolymer (A) is set as d-e and the block structure of copolymer (B) is set as a1-b1-a2-c1, it is preferable that the c1 block and the e block have the same structure and the same molecular weight, and it is preferable that the a2 block and the d block are composed of the same vinyl aromatic compound, and it is preferable that the molecular weight of the a2 block is greater than the molecular weight of the d block. Furthermore, when polymerizing using method (3), the timing of adding the initiator in the second stage depends on the ratio of the molecular weights of the a2 block and the d block, preferably at a time when the polymerization conversion rate of the vinyl aromatic compound of the a2 block is 100 × (molecular weight of d block) / (molecular weight of a2 block) (%).

<Distinction between Copolymer (A) and Copolymer (B)> The resin composition of this embodiment contains two components, copolymer (A) and copolymer (B), therefore the GPC plot has more than two peaks. Copolymer (A) refers to all components with a number average molecular weight of 40,000 or less.

The copolymer before hydrogenation is not limited to the following; for example, it can be obtained by using an organoalkali metal compound or other polymerization initiator in a hydrocarbon solvent, and carrying out living anionic polymerization using specified monomers. The hydrocarbon solvent is not particularly limited, and examples include: aliphatic hydrocarbons such as n-butane, isobutane, n-pentane, n-hexane, n-heptane, and n-octane; alicyclic hydrocarbons such as cyclohexane, cycloheptane, and methylcycloheptane; and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene.

As polymerization initiators, organoalkali metal compounds known to have anionic polymerization activity relative to conjugated diene compounds and vinyl aromatic compounds are commonly used. Examples include: aliphatic hydrocarbon alkali metal compounds with 1 to 20 carbon atoms, aromatic hydrocarbon alkali metal compounds with 1 to 20 carbon atoms, and organoamine alkali metal compounds with 1 to 20 carbon atoms. Examples of alkali metals contained in polymerization initiators include, but are not limited to, lithium, sodium, and potassium. Furthermore, one or more alkali metals may be contained in a single molecule. Examples of polymerization initiators include, for example, the reaction products of n-propyl lithium, n-butyl lithium, dibutyl lithium, tributyl lithium, n-pentyl lithium, n-hexyl lithium, benzyl lithium, phenyl lithium, tolyl lithium, and diisopropylbenzene with dibutyl lithium; further examples include the reaction products of divinylbenzene with dibutyl lithium and a small amount of 1,3-butadiene, but are not limited to these. Furthermore, the following lithium compounds may also be used: 1-(tert-butoxy)propyl lithium and lithium compounds containing one to several molecules of isoprene monomer inserted to improve their solubility, as disclosed in US Patent 5,708,092; alkyl lithium compounds containing silaneoxy groups, such as 1-(tert-butyldimethylsiloxy)hexyl lithium, as disclosed in British Patent 2,241,239; and alkyl lithium compounds containing amino groups, such as diisopropylamide lithium and bis(trimethylsilane)amino lithium, as disclosed in US Patent 5,527,753.

The amount of lithium compound used as a polymerization initiator depends on the molecular weight of the target copolymer, preferably 0.005 to 6.4 phm (relative to parts by mass of 100 parts by mass of monomer), and more preferably 0.005 to 2.6 phm.

When using an organoalkali metal compound as a polymerization initiator to copolymerize a conjugated diene compound with a vinyl aromatic compound, a tertiary amine compound or an ether compound may be added to adjust the content of vinyl bonds (1,2-bonds or 3,4-bonds) in the conjugated diene monomer units incorporated into the copolymer, or to adjust the random copolymerization of the conjugated diene compound and the vinyl aromatic compound.

Tertiary amine compounds are not particularly limited, and examples include compounds represented by the following formula: R1R2R3N (where R1, R2, and R3 are hydrocarbons with 1 to 20 carbon atoms or hydrocarbons having a tertiary amine group) Examples of such compounds include: trimethylamine, triethylamine, tributylamine, N,N-dimethylaniline, N-ethylpiperidine, N-methylpyrrolidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, 1,2-dipiperidinylethane, trimethylaminoethylpiperidine, N,N,N',N'',N''-pentamethylethylenediamine, N,N'-dioctyl-p-phenylenediamine, etc., but are not limited to these. Among these, N,N,N',N'-tetramethylethylenediamine is preferred.

Furthermore, ether compounds can be either linear or cyclic. Examples of linear ether compounds include: dimethyl ether, diethyl ether, diphenyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, and other dialkyl ethers of ethylene glycol; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and other dialkyl ethers of diethylene glycol. Examples of cyclic ether compounds include: tetrahydrofuran, dialkylene, 2,5-dimethyloxacyclopentane, 2,2,5,5-tetramethyloxacyclopentane, 2,2-bis(2-oxacyclopentyl)propane, and alkyl ethers of furfuryl alcohol.

The amount of tertiary amine or ether compound used relative to the polymerization initiator of the above-mentioned organoalkali metal compound is preferably 0.1 to 4 (moles/1 mole of alkali metal), more preferably 0.2 to 3 (moles/1 mole of alkali metal).

Sodium alkyl alcohols may coexist during the copolymerization process in the manufacturing steps of copolymers (A) and (B). The sodium alkyl alcohols are not limited to those listed below; for example, compounds represented by the following formulas can be cited. Sodium alkyl alcohols having an alkyl group having 3 to 6 carbon atoms are particularly preferred, and sodium tributanol and sodium tripentanol are even more preferred. NaOR (where R is an alkyl group with 2 to 12 carbon atoms) The amount of sodium alkanoate used in the polymerization steps of copolymers (A) and (B) relative to the vinyl bond modifier (tertiary amine compound or ether compound) is preferably 0.01 or more but less than 0.1 (molar ratio), more preferably 0.01 or more but less than 0.08 (molar ratio), further preferably 0.03 or more but less than 0.08 (molar ratio), and even more preferably 0.04 or more but less than 0.06 (molar ratio). If the amount of sodium alkanol is within this range, there is a tendency to produce copolymers with high yields, comprising copolymer blocks containing conjugated diene monomers with a high vinyl bond content, and polymer blocks with narrow molecular weight distributions, primarily composed of vinyl aromatic monomers.

The method for copolymerizing conjugated dienes with vinyl aromatic compounds using organoalkali metal compounds as polymerization initiators is not particularly limited; it can be batch polymerization, continuous polymerization, or a combination thereof. The polymerization temperature is not particularly limited, typically ranging from 0 to 180°C, preferably from 30 to 150°C. The polymerization time varies depending on the conditions, typically within 48 hours, preferably from 0.1 to 10 hours. Furthermore, polymerization is preferably carried out in an inert gas atmosphere such as nitrogen. Regarding the polymerization pressure, it is not particularly limited as long as it is sufficient to maintain the monomer and solvent in the liquid phase within the above-mentioned polymerization temperature range.

Furthermore, a coupling reaction can be carried out by adding a necessary amount of a difunctional or higher coupling agent at the end of polymerization. There are no particular limitations on the difunctional or higher coupling agent, and known agents may be used. Examples of difunctional coupling agents include, but are not limited to, dihalogen compounds such as dimethyldichlorosilane and dimethyldibromosilane, methyl benzoate, ethyl benzoate, phenyl benzoate, phthalates, and other acid esters. Examples of polyfunctional coupling agents with trifunctional or higher functions include: 1,1,1,2,2-pentachloroethane, perchloroethane, pentachlorobenzene, perchlorobenzene, octabromodiphenyl ether, decabromodiphenyl ether, polyols with three or more nucleotides, epoxidized soybean oil, diglycidyl bisphenol A and other polyepoxide compounds, di- to hexafunctional compounds containing epoxy groups, carboxylic acid esters, divinylbenzene and other polyvinyl compounds, halogenated silicon compounds represented by the formula R1 _{(4 - n) SiXn} (where R1 represents an hydrocarbon with 1 to 20 carbon atoms, X represents a halogen, and n represents an integer of 3 or 4), and halogenated tin compounds, but are not limited to these. Examples of halogenated silicon compounds include, but are not limited to, methyltrichlorosilane, tributyltrichlorosilane, silicon tetrachloride, and their bromides. Examples of halogenated tin compounds include, but are not limited to, polybasic halogen compounds such as methyltin trichloride, tributyltin trichloride, and tin tetrachloride. Dimethyl carbonate or diethyl carbonate may also be used.

Copolymer (A) and copolymer (B) can also be obtained by adding the active ends of the block copolymers obtained by the method described above with a modifier that generates functional groups. Examples of functional groups include, but are not limited to, groups containing at least one functional group selected from the group consisting of: hydroxyl, carbonyl, thiocarbonyl, acetyl halide, acid anhydride, carboxyl, thiocarboxyl, aldehyde, thioaldehyde, carboxylic acid ester, acetylamine, sulfonic acid, sulfonate, phosphoric acid, phosphate ester, amino, imine, nitrile, pyridinyl, quinolinyl, epoxy, thioepoxy, thio, isocyanate, isothiocyanate, halogenated silica, silanol, alkoxysilyl, halogenated tin, alkoxytin, and phenyltin.

Examples of modifiers that generate functional groups include, but are not limited to, tetraglycidyl-m-phenylenediamine, tetraglycidyl-1,3-diaminomethylcyclohexane, ε-caprolactone, δ-valerolactone, 4-methoxybenzophenone, γ-glycidyloxyethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyldimethylphenoxysilane, bis(γ-glycidyloxypropyl)methylpropoxysilane, 1,3-dimethyl-2-imidazolidineone, 1,3-diethyl-2-imidazolidineone, N,N'-dimethylpropylurea, and N-methylpyrrolidone. The amount of modifier added relative to 100 parts by weight of the copolymer before modification is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, and further preferably 0.3 to 10 parts by weight. The addition reaction temperature of the modifier is preferably 0 to 150°C, more preferably 20 to 120°C. The time required for the modification reaction varies depending on the modification reaction conditions, preferably within 24 hours, more preferably 0.1 to 10 hours.

The copolymer (A) is preferably manufactured by performing a hydrogenation step after the polymerization step described above or after the modification step described above. The hydrogenation catalyst used to manufacture the copolymer (A) is not particularly limited, and for example, hydrogenation catalysts described in Japanese Patent Publication Nos. 42-8704, 43-6636, 63-4841, 1-37970, 1-53851, and 2-9041 may be used. Preferred hydrogenation catalysts include, for example, titanium diacene compounds and/or mixtures with reducing organometallic compounds. The titanium-ceramsite compounds are not particularly limited, and examples include compounds described in Japanese Patent Application Publication No. 8-109219. Specifically, examples include dicyclopentadienyl titanium dichloride and monopentamethylcyclopentadienyl titanium trichloride, which have at least one ligand with a (substituted) cyclopentadienyl, indole, or tandem structure. The reducing organometallic compounds are not particularly limited, and examples include organolithium and other organolithic metal compounds, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds. The reaction temperature for the hydrogenation reaction is typically 0–200°C, preferably 30–150°C. The pressure of the hydrogen gas used in the hydrogenation reaction is preferably 0.1–15 MPa, more preferably 0.2–10 MPa, and even more preferably 0.3–5 MPa. The reaction time of the hydrogenation reaction is typically 3 minutes to 10 hours, preferably 10 minutes to 5 hours. Furthermore, the hydrogenation reaction can be performed using batch processes, continuous processes, or any combination thereof.

The copolymer (B) is preferably manufactured by performing a hydrogenation step after the polymerization step described above or after the modification step described above. The hydrogenation catalyst used to manufacture the copolymer (B) is not particularly limited, and for example, hydrogenation catalysts described in Japanese Patent Publication Nos. 42-8704, 43-6636, 63-4841, 1-37970, 1-53851, and 2-9041 may be used. Preferred hydrogenation catalysts include, for example, titanium diacene compounds and/or mixtures with reducing organometallic compounds. The titanium-ceramsite compounds are not particularly limited, and examples include compounds described in Japanese Patent Application Publication No. 8-109219. Specifically, examples include dicyclopentadienyl titanium dichloride and monopentamethylcyclopentadienyl titanium trichloride, which have at least one ligand with a (substituted) cyclopentadienyl, indole, or tandem structure. The reducing organometallic compounds are not particularly limited, and examples include organolithium and other organolithic metal compounds, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds. The reaction temperature for the hydrogenation reaction is typically 0–200°C, preferably 30–150°C. The pressure of the hydrogen gas used in the hydrogenation reaction is preferably 0.1–15 MPa, more preferably 0.2–10 MPa, and even more preferably 0.3–5 MPa. The reaction time of the hydrogenation reaction is typically 3 minutes to 10 hours, preferably 10 minutes to 5 hours. Furthermore, the hydrogenation reaction can be performed using batch processes, continuous processes, or any combination thereof.

Catalyst residues can also be removed from the reaction solution after the hydrogenation step, if necessary. When manufacturing hydrogenated copolymers using anionic living polymerization, compounds containing metal atoms in the hydrogenation catalyst during the aforementioned hydrogenation reaction may react with moisture in the air during solvent removal steps, generating specified metal compounds that remain in the hydrogenated copolymer. If such compounds are present in the resin composition and its cured product of this embodiment, there is a tendency for an increase in dielectric constant and dielectric loss factor, which in turn may lead to ion migration in electronic material applications. Examples of residual metal compounds include: compounds of metals contained in polymerization initiators and hydrogenation catalysts, such as oxides of titanium oxide, amorphous titanium oxide, ortho-titanic acid or meta-titanic acid, titanium hydroxide, nickel hydroxide, nickel monoxide, lithium oxide, lithium hydroxide, cobalt oxide, cobalt hydroxide, etc., as well as complex oxides of lithium tannate, barium tannate, strontium tannate, nickel tannate, nickel iron oxide, etc., containing atoms of dissimilar metals. From the perspectives of achieving low dielectric constant, low dielectric loss factor, and minimal ion migration, the residual amount of metal compounds in copolymers (A) and (B), expressed as residual metal content, is preferably 150 ppm or less, more preferably 130 ppm or less, further preferably 100 ppm or less, and even more preferably 90 ppm or less. Examples of typical residual metals include Ti, Ni, Li, and Co.

As a method for reducing the residual metal content in the resin composition and its cured product of this embodiment, previously known methods can be applied without particular limitation. For example, the following methods can be used: after the hydrogenation reaction of copolymers (A) and (B), water and carbon dioxide are added to neutralize the hydrogenation catalyst residue; in addition to water and carbon dioxide, acid is added to neutralize the hydrogenation catalyst residue. Specifically, the method described in Japanese Patent Application 2014-557427 can be applied. Even when using such metal removal methods, since water containing hydrogen oxides of metal compounds is mixed in during the solvent removal step of copolymers (A) and (B), the metal content is usually around 1 to 15 ppm. Therefore, it is preferable to remove more than 20% of the metal relative to the amount added to copolymers (A) and (B), more preferably more than 30%, further preferably more than 40%, further preferably more than 50%, and further preferably more than 60%.

Furthermore, by reducing the amount of added polymerization initiator and hydrogenation catalyst, the residual metal content in copolymers (A) and (B) can also be reduced. However, if the amount of polymerization initiator is reduced, the molecular weight of copolymers (A) and (B) increases. If this exceeds the necessary range for the molecular weight of copolymers (A) and (B) constituting the resin composition of the present embodiment, there is a tendency for the heat resistance of the cured product to decrease. Moreover, if the amount of hydrogenation catalyst is reduced during the hydrogenation reaction, there is a tendency for the hydrogenation reaction time to become longer and the hydrogenation reaction temperature to become higher, resulting in a significant decrease in productivity.

Methods for separating copolymers (A) and (B) from solvents include, for example, adding acetone or alcohol, a polar solvent that is unsuitable for copolymers (A) and (B), to a solution of copolymers (A) and (B) to cause copolymers (A) and (B) to precipitate and be recovered; or immersing a solution of copolymers (A) and (B) in hot water under stirring and removing the solvent by steam stripping; or removing the solvent by direct heating of a solution of copolymers (A) and (B), but are not limited to these methods.

For copolymers (A) and (B), antioxidants can be added during manufacturing to make their surface and/or interior contain antioxidants. Furthermore, the antioxidants described below can also be added to the resin composition of this embodiment.

Examples of antioxidants include, but are not limited to, phenolic antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, and amine-based antioxidants. Specifically, examples include: 2,6-di-tert-butyl-4-methylphenol, octadecyl 3-(4'-hydroxy-3',5'-di-tert-butyl-phenyl)propionate, tetra-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, tri-(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 4,4'-butylene-bis-(3-methyl-6-tert-butylphenol), 3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy}-1,1-di [Methylethyl]-2,4,8,10-tetraoxozyro[5,5]undecane, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylaniline)-1,3,5-tris(2,4-ethylhexyl)-pentaerythritol-tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylbis[3-(3,5-ethylhexyl)-2,4,8,10-tetraoxozyro[5,5]undecane, triethylene glycol- ... [-Di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), 3,5-di-tert-butyl-4-hydroxybenzyl phosphonate diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, a mixture of bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonate ethyl ester) calcium and polyvinyl wax (50%), octyl diphenylamine, 2,4-bis[(octylthio)methyl]-o-cresol, 3-(3,5-di-tert-butyl- Isooctyl 4-hydroxyphenyl)propionate, 3,3-bis(3-tert-butyl-4-hydroxyphenyl)vinyl butyrate, 1,1,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, and 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)-ethyl]-4,6-di-tert-pentylphenyl acrylate, etc. Furthermore, from the viewpoint of insulation reliability, the above-mentioned antioxidants can also be used as particle adhesion inhibitors.

Examples of polymerization terminators include, but are not limited to, various alcohols such as water, methanol, ethanol, isopropanol, 2-ethylhexanol, heptanol, and mixtures thereof.

Copolymer (B) and/or copolymer (A) can also be granulated. These can be granulated individually or as a mixture. Methods for granulation include, for example, the following: extruding copolymer (B) and/or copolymer (A) in a filament from a uniaxial or biaxial extruder, and cutting it in water using a rotating blade positioned in front of the die; extruding copolymer (A) and/or (B) in a filament from a uniaxial or biaxial extruder, followed by water or air cooling, and then cutting it using a wire cutter; melting and mixing the copolymers using an open roll or a Bamboo mixer, forming them into sheets using rollers, cutting the sheets into short strips, and then cutting them into cubic granules using a granulator. Furthermore, there are no particular limitations on the size and shape of the copolymer (B) and/or copolymer (A) granules. In the particles of copolymer (B) and/or copolymer (A), a particle adhesion inhibitor may also be formulated as needed for the purpose of preventing particle adhesion. Examples of particle adhesion inhibitors include, but are not limited to, calcium stearate, magnesium stearate, zinc stearate, polyethylene, polypropylene, ethyl bis-stearamide, talc, and amorphous silica. From the viewpoint of ion migration, EBS, polyethylene, and polypropylene are preferred particle adhesion inhibitors. A preferred formulation amount of the particle adhesion inhibitor is 500–6000 ppm relative to copolymer (A) and/or (B), and a more preferred amount is 1000–5000 ppm. The particle adhesion inhibitor is preferably formulated to adhere to the particle surface, but it can also be incorporated into the particles to some extent.

(Molecular weight distribution of copolymer (A) and copolymer (B)) The molecular weight distribution (Mwa/Mna) of copolymer (A) is preferably 1.01–8.0, more preferably 1.01–6.0, and even more preferably 1.01–5.0. If the molecular weight distribution is within the above range, the resin composition of this embodiment tends to have excellent heat resistance. Furthermore, the shape of the molecular weight distribution of copolymer (A) measured by GPC is not particularly limited; it can be a multi-peak molecular weight distribution with two or more peaks, or a single-peak molecular weight distribution with only one peak. Furthermore, the weight-average molecular weight (Mwa) and molecular weight distribution [Mwa/Mna; the ratio of weight-average molecular weight (Mwa) to number-average molecular weight (Mna)] of copolymer (A) can be determined using a calibration curve (made using the peak molecular weight of standard polystyrene) obtained from the determination of the molecular weight of the peak of the chromatogram measured by GPC in the method described in the following embodiments.

The molecular weight distribution (Mwb/Mnb) of copolymer (B) is preferably 1.01–8.0, more preferably 1.01–6.0, and even more preferably 1.01–5.0. If the molecular weight distribution is within the above range, the resin composition of this embodiment tends to have excellent heat resistance. Furthermore, the shape of the molecular weight distribution of copolymer (B) measured by GPC is not particularly limited; it can be a multi-peak molecular weight distribution with two or more peaks, or it can be a single-peak molecular weight distribution with only one peak. Furthermore, the weight-average molecular weight (Mwb) and molecular weight distribution [Mwb/Mnb; the ratio of weight-average molecular weight (Mwb) to number-average molecular weight (Mnb)] of copolymer (B) can be determined using a calibration curve (made using the peak molecular weight of standard polystyrene) obtained from the determination of the molecular weight of the peak of the chromatogram measured by GPC in the method described in the following embodiments.

(Mass ratio of copolymer (A) to copolymer (B)) From a productive point of view, in the resin composition of this embodiment, the mass ratio (A)/(B) of the aforementioned copolymer (A) to copolymer (B) is preferably 5/95 to 70/30, more preferably 10/90 to 60/40, and even more preferably 15/85 to 50/50.

(Content of copolymer (A) and copolymer (B)) The total content of copolymer (A) and copolymer (B) in the resin composition of this embodiment is not particularly limited. However, it is preferably 5 to 60 parts by weight relative to 100 parts by weight of resin solids in the resin composition of this embodiment. Furthermore, from the viewpoint of imparting softness, low dielectric constant, and low dielectric loss factor to the resin composition of this embodiment, the lower limit of the total content of copolymer (A) and copolymer (B) is preferably 6 parts by weight or more, and more preferably 8 parts by weight or more. Furthermore, from the perspective of suppressing the decrease in glass transition temperature, the increase in thermal linear expansion, and the deterioration of viscosity of the resin composition of this embodiment, the upper limit of the total content of copolymer (A) and copolymer (B) is preferably 50 parts by weight or less, and more preferably 40 parts by weight or less. The term "resin solids content" refers to the components obtained after removing fillers and solvents from the resin composition.

(Components constituting the resin composition) The resin composition of this embodiment comprises the copolymer (A) and copolymer (B) described above, and at least one component selected from the group consisting of components (I) to (III) below. Component (I): Curing resin (excluding copolymer (A) and copolymer (B)) Component (II): Free radical initiator Component (III): Curing agent (excluding component (I)) From the viewpoint of the crack resistance of the resin composition of this embodiment, it is preferable to include component (I): curing resin.

<Component (I): Curing Resin (excluding copolymers (A) and (B))> The resin composition of this embodiment may also contain the aforementioned component (I) of the curing resin (excluding copolymers (A) and (B)) to impart properties such as heat resistance and adhesion to the substrate, without compromising the dielectric properties of the cured product. The curing resin (I) has the effect of improving strength or heat resistance through crosslinking in the resin composition of this embodiment. By giving the curing resin polar groups, there is a tendency for the resin composition and the cured product of this embodiment to have excellent heat resistance. As component (I): the curing resin (excluding copolymer (A) and copolymer (B)), preferably selected from at least one of the group consisting of epoxy resins, polyimide resins, polyphenylene ether resins, liquid crystal polyester resins, and fluorinated resins, and more preferably epoxy resins, polyimide resins, and polyphenylene ether resins, with regard to the heat resistance and adhesion of the resin composition of this embodiment.

From the perspective of the heat resistance of the resin composition of this embodiment, the polyimide resin as component (I) only needs to have amide bonds in the repeating units to fall within the scope of being called a polyimide resin. For example, the structure of a common polyimide obtained by condensing tetracarboxylic acid or its dianhydride with a diamine (amide bond) can be cited, but it is not limited to this. From the perspective of curability, it is preferable that the polyimide structure described above has unsaturated groups at its ends. Examples of polyimide resins having unsaturated groups at the ends include: cis-butenediamide-type polyimide resins, dioxinamide-type polyimide resins, and allyl dioxinamide-type polyimide resins. Examples of the tetracarboxylic acids or their dianhydrides include, but are not limited to, aromatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aliphatic tetracarboxylic dianhydrides. One or more of these can be used alone. Examples of the diamines commonly used in the synthesis of polyimides include aromatic diamines, alicyclic diamines, and aliphatic diamines. One or more of these can be used alone. Furthermore, from the viewpoint of reducing the dielectric constant and dielectric loss factor of the cured resin composition of this embodiment, at least one or more functional groups selected from the group consisting of fluorine, trifluoromethyl, hydroxyl, ternary, carbonyl, heterocyclic, long-chain alkyl, allyl, etc., may be present in at least one of the aforementioned tetracarboxylic acid or its dianhydride or diamine. Furthermore, component (I) may also use commercially available polyimide resins, such as: Neopulim (registered trademark) C-3650 (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), Neopulim C-3G30 (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), Neopulim C-3450 (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), Neopulim P500 (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), BT (bis(cis-butenediamide-trimethyl) resin) (manufactured by Mitsubishi Gas Chemical Co., Ltd.), JL-20 (manufactured by Shin Nippon Rika Co., Ltd., trade name) (silicon dioxide may also be included in the varnish of these polyimide resins), Rica Coat SN20 manufactured by Shin Nippon Rika Co., Ltd., and Rica Coat... PN20, Pyre-ML manufactured by I.S.T., UPIA-AT, UPIA-ST, UPIA-NF, UPIA-LB manufactured by Ube Industries, Ltd., PIX-1400, PIX-3400, PI2525, PI2610, HD-3000, AS-2600 manufactured by Hitachi Chemical, HPC-5000, HPC-5012, HPC-1000, HPC-5020, HPC-3010, HPC-6000, HPC-9000, HCI-7000, HCI-1000S, HCI-1200E, HCI-1300 manufactured by Showa Denko Corporation, BMI-2300 manufactured by Daiwa Chemical Industries, Ltd., and MIR-3000 manufactured by Nippon Chemicals, Ltd.

The polyphenylene ether resin used as component (I) only needs to fall within the category of resins called polyphenylene ether resins, and must contain phenylene ether units as repeating structural units. It can be a homopolymer containing phenylene ether units, or a polymer containing structural units other than phenylene ether units. As a homopolymer containing phenylene ether units, there is no particular restriction on whether the phenyl group in the phenyl group has substituents. Examples of substituents include: ethyl, propyl, isopropyl, butyl, isobutyl, tributyl, etc. (acrylic, cyclohexyl, etc.), vinyl, allyl, isopropenyl, 1-butenyl, 1-pentenyl, p-vinylphenyl, p-isopropenylphenyl, m-vinylphenyl, m-isopropenylphenyl, etc. Orthovinylphenyl, orthoisopropenylphenyl, p-vinylbenzyl, p-isopropenylbenzyl, m-vinylbenzyl, m-isopropenylbenzyl, orthovinylbenzyl, orthoisopropenylbenzyl, p-vinylphenylvinyl, p-vinylphenylpropenyl, p-vinylphenylbutenyl, m-vinylphenylvinyl, m-vinylphenylpropenyl, m-vinylphenylbutenyl, orthovinylphenylvinyl, orthovinylphenylpropenyl, orthovinyl... Substituents containing unsaturated bonds, such as alkenylphenylbutenyl, methacrylyl, acrylyl, 2-ethylacrylyl, and 2-hydroxymethylacrylyl, include hydroxyl, carboxyl, carbonyl, thiocarbonyl, acetyl halide, acid anhydride, carboxylic acid, thiocarboxylic acid, aldehyde, thioaldehyde, carboxylic acid ester, acetamino, sulfonic acid, sulfonate, phosphoric acid, phosphate, phosphate ester, amino, imino, nitrile, pyridyl, quinolinyl, epoxy, and thioyl groups. Substituents containing functional groups, such as epoxy, sulfide, isocyanate, isothiocyanate, halogenated silica, silanol, alkoxysilyl, halogenated tin, borate, boron-containing, borate, alkoxytin, and phenyltin, are preferably polar groups with defined properties intended to exhibit free radical reactivity and/or reactivity with component (III): the curing agent. From the perspective of the curability of the resin composition of this embodiment, the molecular weight of the polyphenylene ether resin is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 10,000 or less. Furthermore, polyphenylene ether resins can be linear, cross-linked, or branched.

As a component (I), any liquid crystal polyester resin that forms an anisotropic molten phase falls within the category of liquid crystal polyester resins. Examples include: Eastman Kodak's "X7G," Dartco's Xyday, Sumitomo Chemical's Econol, and Celanese's Vectra.

The epoxy resin used as component (I) only needs to fall within the category of being called epoxy resin. From the viewpoint of the strength of the resin composition of this embodiment, it is preferable to have two or more epoxy groups per molecule. The epoxy resin can be used alone or in combination of two or more. Examples of epoxy resins include: bixylenol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenol-type epoxy resins, naphthol-phenolic varnish-type epoxy resins, phenol-phenolic varnish-type epoxy resins, tributyl-orthoquinone-type epoxy resins, naphthalene-type epoxy resins, and naphthol-type epoxy resins. Epoxy resins include: anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol-phenolic varnish-type epoxy resins, biphenyl-type epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, spirocyclic epoxy resins, cyclohexane-type epoxy resins, cyclohexane-diethanol-type epoxy resins, naphthyl ether-type epoxy resins, trihydroxymethyl-type epoxy resins, and tetraphenylethane-type epoxy resins, etc.

Furthermore, from a reactivity point of view, when epoxy resin is used as component (I), the resin composition of this embodiment preferably contains the following component (III): hardener. As component (III): the polar groups possessed by the hardener, for example: carboxyl, imidazole, hydroxyl, amino, thiol, benzo[a]yl, carbodiimide. From the viewpoint of reactivity, carboxyl, imidazole, hydroxyl, benzo[a]yl, and carbodiimide are preferred. From the viewpoint of the low dielectric constant and low dielectric loss factor of the resin composition and the hardened product of this embodiment, hydroxyl, carboxyl, imidazole, benzo[a]yl, and carbodiimide are even more preferred, and hydroxyl, carboxyl, and carbodiimide are even more preferred.

Furthermore, two or more polar resins with different free radical reactivity can be used as component (I). In such cases, from the viewpoint of the curing properties of the resin composition of this embodiment, component (II) and component (III) can be used alone or in combination. For example, when using cis-butadiene-type polyimide resin with excellent free radical reactivity and bisphenol A epoxy resin without free radical reactivity as component (I), from the viewpoint of the curing properties of the resin composition of this embodiment, component (II) (free radical initiator) and component (III) (curing agent) can be used in combination.

Furthermore, when using a high-melting-point and high-rigidity polar resin as component (I), the curing agent described in component (III) below may be omitted. Examples of high-melting-point and high-rigidity polar resins include liquid crystal polyester resins and fluorinated resins such as polytetrafluoroethylene. By making component (I) high-melting-point and high-rigidity, even without containing component (III) below: the curing agent, the resin composition of this embodiment tends to possess the practically necessary heat resistance and/or strength.

From the perspective of heat resistance, the content of component (I) in the resin composition of this embodiment, relative to 100 parts by weight of the resin solids content of the resin composition of this embodiment, is preferably 10 to 90 parts by weight, more preferably 15 to 85 parts by weight, and even more preferably 20 to 80 parts by weight. The so-called resin solids content refers to the components obtained after removing fillers and solvents from the resin composition.

<Component (II): Free Radical Initiator> As Component (II): Free Radical Initiator, previously known agents may be used, such as thermal free radical initiators, which are preferred. Examples of thermal free radical initiators include: hydrogen peroxides such as diisopropylbenzene peroxide (Percumyl P), isopropylbenzene peroxide (Percumyl H), and tributyl hydrogen peroxide (Perbutyl H); α,α-bis(tributylperoxy-m-isopropyl)benzene (Perbutyl P), diisopropylbenzene peroxide (Percumyl D), 2,5-dimethyl-2,5-bis(tributylperoxy)hexane (Perhexa 25B), tributylisopropyl peroxide (Perbutyl C), di-tributylperoxide (Perbutyl D), 2,5-dimethyl-2,5-bis(tributylperoxy)hexyn-3 (Perhexyne 25B), and tributyl peroxy-2-ethylhexanoate (Perbutyl Dialkyl peroxides such as O; ketone peroxides; peroxy ketal esters such as 4,4-di-(tert-butylperoxy)valerate (Perhexa V); diacetyl peroxides; peroxydicarbonates; organic peroxides such as peroxy esters; azo compounds such as 2,2-azobisisobutylnitrile, 1,1'-(cyclohexane-1-1-formonitrile), 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile), etc., but not limited to these. One or more of these compounds may be used alone.

When the aforementioned component (I): the cured resin is a resin with free radical reactivity, the amount of component (II): the free radical initiator can be adjusted arbitrarily according to the reactivity, or component (II): the free radical initiator may not be added. The free radical reactivity of component (I) can be exemplified by homopolymers of compounds containing at least one vinyl and/or halogen element, and/or copolymers with any compound. From the viewpoint of the low dielectric constant and low dielectric loss factor of the resin composition and cured product of this embodiment, it is preferable that the aforementioned homopolymers and/or copolymers contain vinyl groups. The term "containing vinyl groups" can refer to polymers that comprise repeating units containing vinyl groups, or it can refer to polymers containing vinyl groups obtained by reacting a compound containing vinyl groups and polar groups with the polar groups of a resin containing polar groups. Examples of compounds containing vinyl groups and polar groups include: (meth)acrylic acid (in this specification, "(meth)acryl" means "methacryl or acrylonitrile"), maleic acid, monoalkyl maleic acid esters, fumaric acid and other vinyl monomers containing carboxyl groups, vinyl sulfonic acid, (meth)allyl sulfonic acid, methyl vinyl sulfonic acid, styrene sulfonic acid and other vinyl monomers containing alkyl groups, hydroxystyrene, N-hydroxymethyl (meth)acrylamide, (meth)acrylate hydroxyethyl ester, (meth)acrylate hydroxypropyl ester and other vinyl monomers containing hydroxyl groups, 2-hydroxyethyl (meth)acrylamide phosphate, phenyl-2-acryloxyethyl phosphate, 2-acryloxyethylphosphonic acid and other vinyl monomers containing phosphate groups. The list includes vinyl monomers containing hydroxyl groups, such as hydroxystyrene, N-hydroxymethyl (meth)acrylamide, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, 1-buten-3-ol, aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, nitrile (meth)acrylamide, N-methyl (meth)acrylamide, N-butylacrylamide, methacrylonitrile, cyanostyrene, cyanoacrylate, glycidyl methacrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenylphenyl oxide. Vinyl monomers containing epoxy groups, such as phenyl phenyl oxide; vinyl monomers containing polyisocyanate groups, such as urea diketone; and vinyl monomers containing polyisocyanate groups, such as isocyanurates. Monomers containing halogen elements include, for example: vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

When component (I): the curing resin has low or no free radical reactivity, from a reactivity point of view, the resin composition of this embodiment preferably contains component (III): a curing agent. Component (III): the curing agent generally has the function of reacting with the curing resin of component (I) to cure the resin composition. The so-called "reaction" between component (I) and the curing agent of component (III) means that the polar groups of each component are covalently bonded to each other. If the polar groups react with each other, for example, the OH group of the carboxyl group is desorbed, the original polar group changes or disappears, but a covalent bond is formed thereby, this is included in the definition of "reactivity" of polar groups.

From the perspective of heat resistance, the content of component (II) in the resin composition of this embodiment, relative to 100 parts by weight of the resin solids content of the resin composition of this embodiment, is preferably 0.01 parts by weight to 5 parts by weight, more preferably 0.02 parts by weight to 4 parts by weight, and even more preferably 0.03 parts by weight to 3 parts by weight. The so-called resin solids content refers to the components obtained after removing fillers and solvents from the resin composition.

<Component (III): Hardener (excluding Component (I)> From the perspective of hardening function, it is preferable that the hardener of Component (III) has at least two polar groups in one molecular chain that can react with the functional groups of Component (I): the hardener resin. Component (III) may be used alone or in combination of two or more. The types of polar groups possessed by components (I) and (III) are not particularly limited. Examples include: Epoxy groups with carboxyl, carbonyl, ester, imidazole, hydroxyl, amino, thiol, benzo[a]yl, carbodiimide; Amino groups with carboxyl, carbonyl, hydroxyl, acid anhydride, sulfonic acid, aldehyde; Isocyanate groups with hydroxyl, carboxylic acid; Acid anhydride groups with hydroxyl; Silanol groups with hydroxyl, carboxylic acid; Halogen groups with carboxylic acid, carboxylic acid ester, amino, phenol, thiol; Alkoxy groups with hydroxyl, alkoxide, amino; Butenidimide and cyanoyl, etc. The polar groups may be arbitrarily chosen from either component (I): the hardening resin, and component (III): the hardener.

Furthermore, in cases where the polar groups of component (I) and component (III) do not directly react, the possibility of reaction by adding a curing accelerator such as a catalyst is also included in the definition of "reactivity". For example, when component (I) is a resin containing epoxy groups and component (III) is a curing agent containing anhydride groups, the reactivity between epoxy groups and anhydride groups is usually very low. However, by adding a compound containing an amine group as a curing accelerator, the epoxy groups of component (I) react with the amine groups, and some or all of the epoxy groups of component (III) become hydroxyl groups. The resin composition of this embodiment is cured by reacting the aforementioned hydroxyl groups with the anhydride groups of the curing agent in component (III).

When component (I) is a hardening resin with polar groups, from a reactivity point of view, the molar ratio of component (I) to component (III) hardener, expressed as a ratio of polar groups in moles, is preferably (mol of polar groups in component (I)) : (mol of polar groups in component (III)) = 1:0.01 to 1:20, more preferably 1:0.05 to 1:15, and even more preferably 1:0.1 to 1:10. The following are specific examples of the ratio of component (III) to hardener. Examples of hardeners containing ester groups include: EXB9451, EXB9460, EXB, 9460S, HPC8000-65T, HPC8000H-65TM, EXB8000L-65TM, EXB8150-65T, EXB9416-70BK manufactured by DIC Corporation; and YLH1026, DC808, YLH1026, YLH1030, and YLH1048 manufactured by Mitsubishi Chemical Corporation.

Examples of hardeners containing hydroxyl groups include: MEH-7700, MEH-7810, MEH-7851, NHN, CBN, GPH manufactured by Nippon Kayaku Co., Ltd., SN170, SN170, SN180, SN190, SN475, SN485, SN495, SN-495V, SN375 manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., TD-2090, LA-7052, LA-7054, LA-1356, LA-3018-50P, EXB-9500, etc., but are not limited to these.

Examples of curing agents containing benzo[a] group include, but are not limited to, ODA-BOZ manufactured by JFE Chemical Co., Ltd., HFB2006M manufactured by Showa Polymer Co., Ltd., and P-d and F-a manufactured by Shikoku Chemical Co., Ltd.

Examples of curing agents containing isocyanate groups include: bisphenol A dicyanate, polyphenol cyanate, oligomeric (3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanofenyl)phenylpropane, and 1,1-bis(4-cyanofenylphenylmethane). Difunctional cyanate resins such as bis(4-cyano-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanophenyl-1-(methylethylidene))benzene, bis(4-cyanophenyl) sulfide, and bis(4-cyanophenyl) ether; polyfunctional cyanate resins derived from phenolic varnishes and cresolic varnishes; and prepolymers formed by partial triterpenization of such cyanate resins, but not limited to these. Examples of commercially available products include PT30, PT60, ULL-950S, BA230, and BA230S75 manufactured by Ronsa Corporation of Japan.

As a curing agent containing carbodiimido groups, examples include V-03 and V-07 manufactured by Nisshin Shoku Chemical Co., Ltd., but it is not limited to these.

Examples of hardeners containing amino groups include: 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminophen, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylphen, 3,3'-diaminodiphenylphen, m-phenylenediamine, m-phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxy)benzidine. 2,2-bis(4-aminophenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl) benzoxide, bis(4-(3-aminophenoxy)phenyl) benzoxide, etc., but not limited to these. Examples of commercially available products include KAYABOND C-200S, KAYABOND C-100, Kayahard A-A, Kayahard A-B, and Kayahard A-S manufactured by Nippon Kayaku Co., Ltd., and EPI-CURE W manufactured by Mitsubishi Chemical Co., Ltd. Furthermore, from a reactivity perspective, as a curing agent containing an amino group, a primary amine and/or a secondary amine is preferred, and a primary amine is even more preferred.

Examples of curing agents containing anhydride groups include: phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methyl terephthalic anhydride, hydrogenated methyl terephthalic anhydride, trialkyl tetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-di-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic dianhydride, and benzophenone tetracarboxylic acid. Polymer anhydrides such as dianhydrides, biphenyltetracarboxylic acid dianhydrides, naphthalenetetracarboxylic acid dianhydrides, oxophthalic acid dianhydrides, 3,3',4,4'-diphenyltetracarboxylic acid dianhydrides, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(trimethicone ester), and styrene-citric acid resins copolymerized from styrene and maleic acid, but not limited to these.

Furthermore, compounds possessing at least two of the aforementioned structures exhibiting free radical reactivity also possess the function of reacting with component (I) to harden the resin composition of this embodiment, and therefore can be used as component (III): the hardener. Examples of compounds possessing at least two structures exhibiting free radical reactivity include: allyl isocyanurate (Taic manufactured by Mitsubishi Chemical Co., Ltd.), tris(2-hydroxyethyl) isocyanurate, diallyl transbutenedioic acid, diallyl adipate, allyl citrate, diallyl hexahydrophthalate, and other allyl monomers.

From the perspective of heat resistance, the content of component (III) in the resin composition of this embodiment, relative to 100 parts by weight of the resin solids content of the resin composition of this embodiment, is preferably 10 to 90 parts by weight, more preferably 15 to 85 parts by weight, and even more preferably 20 to 80 parts by weight. The so-called resin solids content refers to the components obtained after removing fillers and solvents from the resin composition.

<Component (IV): Additives> The resin composition of this embodiment may further include, as component (IV), a curing accelerator, filler, flame retardant, and other additives. Furthermore, the additives included as additives in copolymers (A) and (B) have the same meaning as those indicated in component (IV) of the aforementioned resin composition.

As a hardening accelerator, it is added to promote the reactivity between the above-mentioned components, and previously known hardening accelerators can be used. Examples of hardening accelerators include: phosphorus-based hardening accelerators, amine-based hardening accelerators, imidazole-based hardening accelerators, guanidine-based hardening accelerators, and metal-based hardening accelerators. A hardening accelerator can be used alone or in combination of two or more.

Examples of phosphorus-based hardening accelerators include: triphenylphosphine, phosphorus borate compounds, tetraphenylphosphine tetraphenylborate, n-butylphosphine tetraphenylborate, tetrabutylphosphine decanoate, (4-methylphenyl)triphenylphosphine thiocyanate, tetraphenylphosphine thiocyanate, butyltriphenylphosphine thiocyanate, etc., with triphenylphosphine and tetrabutylphosphine decanoate being preferred, but not limited to these.

Examples of amine-based hardening accelerators include 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, but not limited to these.

Examples of imidazole-based hardening accelerators include: 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-phenylimidazole, 1-cyanoethyl-2-methylimidazole. Cycloimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazoleonium trimellitate, 1-cyanoethyl-2-phenylimidazoleonium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-symmetric triazine, 2,4-diamino-6 -[2'-Undecylimidazolyl-(1')]-ethyl-symmetric triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-symmetric triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-symmetric triazine isocyanate adduct, 2-phenylimidazolyl isocyanate adduct, 2-phenyl-4,5-dihydroxymethylimidazolyl Imidazole compounds such as 2-phenyl-4-methyl-5-hydroxymethylimidazolium, 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, are not limited to these, but 2-ethyl-4-methylimidazolium and 1-benzyl-2-phenylimidazolium are preferred. Commercially available imidazole-based hardening accelerators can also be used, such as P200-H50 manufactured by Mitsubishi Chemical Co., Ltd.

Examples of guanidine-based hardening promoters include: dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(ortho-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec- 5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, 1-(ortho-tolyl)biguanide, etc., preferably dicyandiamide, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, but not limited to these.

Examples of metal 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. Examples of organometallic complexes include: organocobalt (II) and organocobalt (III) acetoacetone complexes; organocopper (II) acetoacetone complexes; organozinc (II) acetoacetone complexes; organoiron (III) acetoacetone complexes; organonickel (II) acetoacetone complexes; and organomanganese (II) acetoacetone complexes. Examples of organometallic salts include: zinc octanoate, tin octanoate, zinc cycloalkanoate, cobalt cycloalkanoate, tin stearate, and zinc stearate.

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 oxide, potassium titanate filaments, carbon fibers, alumina, kaolin clay, silica, calcium silicate, quartz, mica, talc, clay, zirconium oxide, potassium titanate, alumina, and metal particles; and organic fillers such as wood chips, wood powder, pulp, and cellulose nanofibers. Each filler can be used alone or in combination with two or more. The shape of such fillers can be any of the following: flaky, spherical, granular, powder, or amorphous, without particular limitation. From the viewpoint of the low dielectric constant and low dielectric loss factor of the resin composition and cured product of this embodiment, silica is preferably used as the filler. Examples of silica include: amorphous silica, molten silica, crystalline silica, synthetic silica, and hollow silica.

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, metal hydroxides, alkyl sulfonates, antimony trioxide, aluminum hydroxide, magnesium hydroxide, zinc borate, and aromatic bromine compounds such as hexabromobenzene, decabromodiphenyl ethane, 4,4-dibromobiphenyl, and ethyltetrabromophenyldimethylimide. These flame retardants can be used alone or in combination with two or more other flame retardants. Among the aforementioned flame retardants, there are also flame retardant accelerants, which have relatively low inherent flame retardant properties but exhibit superior effects when used in combination with other flame retardants.

Fillers and flame retardants may also be of the type that have undergone pre-surface treatment with surface treatment agents such as silane coupling agents. Examples of surface treatment agents include, but are not limited to: fluorinated silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, titanium ester coupling agents, etc. These may be used alone or in combination of two or more.

As for other additives, there are no particular restrictions as long as they are commonly used in the formulation of resin compositions and/or hardeners. Examples of such other additives include: pigments and/or colorants such as carbon black and titanium oxide; lubricants such as stearic acid, benzyl acid, zinc stearate, calcium stearate, magnesium stearate, and ethyl bis-stearamide; mold release agents; and fatty acid esters such as organopolysiloxanes, phthalate or adipate compounds, and azelaic acid ester compounds. Plasticizers such as plasticizers and mineral oils; antioxidants such as hindered phenolic and phosphorus-based heat stabilizers; hindered amine-based light stabilizers; benzotriazole-based ultraviolet absorbers; antistatic agents; organic fillers; tackifiers; defoamers; leveling agents; resin additives such as adhesion promoters; other additives or mixtures thereof, but not limited to these.

From the perspective of the low dielectric constant and low dielectric loss factor of the resin composition and hardened material of this embodiment, it is preferable that it does not contain pigments, colorants, lubricants, mold release agents, or antistatic agents.

The resin composition of this embodiment can be formed by melting and mixing the components, or by dissolving the components in a solvent capable of dissolving them and then stirring (hereinafter referred to as "varnish"). From an operability point of view, varnish is preferred. Examples of solvents include: ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetates such as ethyl acetate, butyl acetate, solvent acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as solvents and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone, etc., but are not limited to these. Organic solvents can be used alone or in combination of two or more.

[Curved Material] The cured material of this embodiment is a cured product of the resin composition of this embodiment, which can be obtained by subjecting the resin composition of this embodiment to a curing reaction at any temperature and time. The term "cured material of this embodiment" refers not only to fully cured products but also to products in which only a portion of the resin composition is cured, leaving uncured components (semi-cured). Further curing steps can also be performed during the manufacturing process of the laminate described below. The reaction temperature for the curing step of the cured material of this embodiment 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 10–240 minutes, more preferably 20–230 minutes, and even more preferably 30–220 minutes. When the resin composition of this embodiment is a varnish, the curing reaction is preferably carried out after the solvent is removed. As a drying method, it can be carried out by previously known methods such as heating or hot air blowing, preferably at a temperature lower than the curing reaction temperature. Regarding the amount of solvent in the resin composition, drying is preferably carried out at 10% by mass or less, more preferably 5% by mass or less.

[Resin Film] The resin film of this embodiment comprises the resin composition of this embodiment. Furthermore, the resin film of this embodiment comprises the hardened material of this embodiment. The resin film of this embodiment can be obtained by uniformly extending a varnish containing the resin composition of this embodiment into a thin film onto a suitable support, and then drying it as described above to remove the solvent. The resin film can be rolled up and stored. The resin film of this embodiment can also be configured as a layered protective film with a defined structure; in this case, it can be used by peeling off the protective film. Examples of the support include: films containing plastic materials, metal foils, release paper, etc. The film containing the plastic material serving as the support can include, for example, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PAN), acrylic resins such as polycarbonate and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. From the perspective of availability and cost, PET and PAN are preferred. As for the metal foil, examples include copper foil and aluminum foil, with copper foil being preferred. As for the copper foil, foils containing only copper can be used, as well as foils containing alloys of copper and other metals (such as tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.). Furthermore, the support can also undergo matte finishing, corona treatment, antistatic treatment, and release treatment on the surface bonded to the resin composite layer.

[Prepreg] The prepreg of this embodiment comprises a substrate and a resin composition or its cured form impregnated in or coated on the substrate. That is, the prepreg of this embodiment is a composite of the resin composition or cured form of this embodiment and the substrate. The prepreg can be obtained, for example, by impregnating a substrate such as glass cloth with a varnish that is the resin composition of this embodiment, and then removing the solvent by the aforementioned drying method. Examples of suitable substrates include: various types of glass cloth such as yarn-torn fabric, cloth, plied felt, and surface felt; asbestos cloth, metal fiber cloth, and other synthetic or natural inorganic fiber cloths; woven or non-woven 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, and felt; natural cellulose-based substrates such as carbon fiber cloth, kraft paper, cotton paper, and cloth obtained from paper-glass blended yarns; and polytetrafluoroethylene porous films. From the viewpoint of dielectric properties, glass cloth is preferred. These substrates can be used alone or in combination of two or more. The proportion of solids in the prepreg comprising the resin composition of this embodiment is preferably 30-80% by mass, more preferably 40-70% by mass. By setting the above proportion to 30% by mass or more, the insulation reliability tends to be superior when the prepreg is used for applications such as electronic substrates. By setting the above proportion to 80% by mass or less, the mechanical properties, such as rigidity, tend to be superior in applications such as electronic substrates.

[Laminator] The laminate of this embodiment includes the resin film and metal foil described above. Furthermore, the laminate of this embodiment includes a cured prepreg and a metal foil described above. The laminate of this embodiment can be manufactured, for example, by the following steps: Step (a), forming a resin layer by laminating a resin film containing the resin composition of this embodiment onto a substrate to obtain a prepreg; Step (b), heating and pressurizing the resin layer to planarize it to obtain a cured prepreg; Step (c), further forming a defined wiring layer including the metal foil on the resin layer. In step (a) above, the method for depositing the resin film on the substrate is not particularly limited. Examples include using a multi-stage press, a vacuum press, an atmospheric pressure laminator, and a laminator that heats and pressurizes under vacuum. Preferably, a laminator that heats and pressurizes under vacuum is used. According to this method, even if the target electronic circuit board has fine wiring circuits on its surface, the resin can be embedded between the circuits without pores. Furthermore, lamination can be batch-type or continuous using rollers. Furthermore, the prepreg constituting the laminate of this embodiment can also be a cured product having a substrate and a resin composition.

In addition to the substrates constituting the prepreg, other substrates that can serve as the substrate for the aforementioned laminate include, for example, glass epoxy boards, metal substrates, polyester substrates, polyimide substrates, polyphenylene ether substrates, and fluoropolymer substrates. The surface of the substrate on which the resin layers are deposited can also be pre-roughened, and there is no limitation on the number of substrate layers.

In step (b) above, the resin film and substrate deposited in step (a) are heated and pressurized to planarize them. The conditions can be arbitrarily adjusted based on the type of substrate or the composition of the resin film; preferably, the temperature is 100–300°C, the pressure is 0.2–20 MPa, and the time is 30–180 minutes. In step (c) above, a defined wiring layer including a metal foil is formed on the resin layer produced by heating and pressurizing the resin film and substrate. The formation method is not particularly limited; previously known methods can be used, such as subtractive etching methods and semi-additive methods. The subtractive plating method involves forming an anti-corrosion coating of the desired pattern onto a metal layer. Subsequent developing removes the portion of the metal layer from which the anti-corrosion has been removed using a chemical solution, thereby forming the desired wiring. The semi-additive plating method involves forming a metal film on the surface of a resin layer using electroless plating. An anti-corrosion coating of the desired pattern is then formed on the metal film. Subsequently, an electrolytic plating process is used to form the metal layer. The unwanted electroless plating layer is then removed using a chemical solution, forming the desired wiring layer.

Furthermore, vias and other pores can be formed in the resin layer as needed. There are no particular limitations on the method of forming the pores, and previously known methods can be used. For example, NC drilling, carbon dioxide laser, UV laser, YAG laser, plasma, etc. can be used as methods for forming pores.

[Metal Foil Laminate] The laminate of the present embodiment described above can be plate-shaped or flexible. The laminate of the present embodiment can also be a metal foil laminate. The metal foil laminate can be obtained by laminating the resin composition of the present embodiment or the prepreg of the present embodiment with metal foil and then curing it, and is configured to have a portion of the metal foil removed from the metal foil laminate. The metal foil laminate is preferably in the form of a hardened prepreg (also called a "hardened composite") and metal foil laminated and closely bonded, and is preferably used as a material for electronic circuit substrates.

Examples of metal foils include aluminum foil and copper foil, with copper foil being preferred due to its lower electrical resistance. The hardened prepreg composite combined with the metal foil can be a single sheet or multiple sheets. Depending on the application, the metal foil is overlapped on one or both sides of the hardened composite to form a laminate. A method for manufacturing the aforementioned laminate can be, for example, the following: forming a prepreg composed of the resin composition of this embodiment and a substrate, overlapping it with the metal foil, and then curing the resin composition, thereby obtaining a laminate consisting of the hardened prepreg and the metal foil. One particularly preferred application of the aforementioned laminate is a printed wiring board. The printed circuit board is preferably formed by removing at least a portion of the metal foil from a metal foil laminate. The printed circuit board of this embodiment can be manufactured by a pressure-heat forming method using the prepreg of this embodiment described above. The same substrate as described above can be used. The printed circuit board, comprising the resin composition of this embodiment, possesses excellent strength and electrical properties (low dielectric constant and low dielectric loss factor), thereby suppressing changes in electrical properties due to environmental variations, and also exhibits excellent insulation reliability and mechanical properties.

[Printed Wiring Board] The printed wiring board of this embodiment includes a cured resin composition of this embodiment. The printed wiring board of this embodiment can be manufactured using the resin composition and/or varnish described above. The printed wiring board of this embodiment includes at least one of the following: a cured resin composition selected from the above-described resin composition, a resin film containing the resin composition or its cured composition of this embodiment, and a prepreg serving as a substrate and a composite of the resin composition or cured composition. The printed wiring board of this embodiment can be used in the form of a resin-coated metal foil. [Example]

The following specific embodiments and comparative examples illustrate this embodiment in detail, but the present invention is not limited by these embodiments in any way. First, the evaluation methods and property measurement methods applied to the embodiments and comparative examples are described below.

[Specific methods for determining the structure and properties of copolymers (A) and (B)] ((1) Content of vinyl aromatic monomers (styrene) in copolymers) The content of vinyl aromatic monomers (styrene) in copolymers before hydrogenation was determined by proton nuclear magnetic resonance ( ^¹H -NMR). The determination was performed under the following conditions: the measuring instrument was JNM-LA400 (manufactured by JEOL), the solvent was deuterated chloroform, the sample concentration was 50 mg/mL, the observation frequency was 400 MHz, the chemical shift standard was tetramethylsilane, the pulse delay was 2.904 seconds, the number of scans was 64, the pulse width was 45°, and the measurement temperature was 26°C. The styrene content was calculated by accumulating the total styrene aromatic signal at 6.2–7.5 ppm of the spectrum.

(2) Vinyl Bonding Amount of the Copolymer) The vinyl bonding amount of the copolymer before hydrogenation was determined by proton nuclear magnetic resonance ( ^1H -NMR). The measurement conditions and data processing methods were the same as those described in (1) above. The vinyl bonding amount was calculated by integrating the signals attributed to 1,4-bonds and 1,2-bonds to obtain the integral value of each 1H for each bonding type. The integral value of 1,2-bonds was divided by the sum of the integral values of 1,4-bonds and 1,2-bonds (in the case of butadiene, and in the case of isoprene, it becomes 3,4-bonds).

((3) The mass ratio of vinyl aromatic monomer units in random polymer blocks (RS) and the content of polymer blocks with vinyl aromatic monomer units as the main component (BS)) Furthermore, it is defined as follows. BSa: Content of polymer blocks in copolymer (A) with vinyl aromatic monomers as the main component. BSb: Content of polymer blocks in copolymer (B) with vinyl aromatic monomers as the main component. RSa: Mass ratio of vinyl aromatic monomers in the random polymer blocks of copolymer (A). RSb: Mass ratio of vinyl aromatic monomers in the random polymer blocks of copolymer (B). Using copolymer (A) and copolymer (B) as test samples, proton nuclear magnetic resonance ( ^1H -NMR, ECS400 manufactured by JOEL RESONABCE) was used to distinguish the vinyl aromatic monomers contained in each sample from those "polymer blocks with vinyl aromatic monomers as the main component" and those "random polymer blocks containing vinyl aromatic monomers and conjugated diene monomers". The experiment was conducted under the following conditions: deuterated chloroform was used as the solvent; the sample concentration was 50 mg/mL; the observation frequency was 400 MHz; tetramethylsilane was used as the chemical shift standard; the pulse delay was 2.904 seconds; the number of scans was 256; and the measurement temperature was 23°C. Based on the integral intensity of the signals attributed to aromatics, the amount of random and block aromatic monomers was calculated from the integral value per 1H of each bonding mode. The total styrene content was then calculated, along with the styrene mass ratio in the random polymer blocks (hereinafter referred to as random styrene content) (RSa)(RSb) and the styrene block content in the copolymer (BSa)(BSb). The calculation method is described below. Styrene block strength (b-St strength) = (cumulative value of 6.9 ppm to 6.3 ppm) / 2 Atactic styrene strength (r-St strength) = (cumulative value of 7.5 ppm to 6.9 ppm) - 3 × (b-St) Ethylene-butene strength (EB strength) = total cumulative value - 3 × {(b-St strength) + (r-St strength)} / 8 Styrene block content (BS) = 104 × (b-St strength) / [104 × {(b-St strength) + (r-St strength)} + 56 × (EB strength)] Atactic styrene content (RS) = 104 × (r-St strength) / {104 × (r-St strength) + 56 × (EB strength)}

((4) Number Average Molecular Weight (Mn)) The number average molecular weights of copolymers (A) and (B) were determined using a GPC [Apparatus: Tosoh HLC8220, TSKgel SuperH-RC column × 2]. Tetrahydrofuran was used as the solvent. The test was conducted at 35°C. The number average molecular weight converted from polystyrene was determined using a calibration curve prepared from commercially available standard polystyrene with a known weight average molecular weight. Here, in the table, the number average molecular weight of copolymer (A) is set as (Mna), and the number average molecular weight of copolymer (B) is set as (Mnb).

(Mass ratio of copolymer (A) and copolymer (B) in (5)) The mass ratio of copolymer (A) and copolymer (B) was determined using a GPC [Apparatus: Tosoh HLC8220, TSKgel SuperH-RC column × 2], employing a mixture of copolymer (A) and copolymer (B). Tetrahydrofuran was used as the solvent. The test was conducted at 35°C. The mass ratio of copolymer (A) and copolymer (B) was calculated from the area ratio of the peaks derived from copolymer (A) and copolymer (B).

(6) Hydrogenation Rate) The hydrogenation rates of copolymers (A) and (B) were determined using a nuclear magnetic resonance apparatus (manufactured by BRUKER, DPX-400). The hydrogenated copolymers were used, and the determination was performed using proton nuclear magnetic resonance ( ^1H -NMR). Specifically, the ratio was calculated by integrating the signal from the residual double bonds (4.5–5.5 ppm) and the signal from the hydrogenated conjugated diene.

((7) Calculation of Average Hydrogenation Rate H (%) and Average Vinyl Bond Amount (V)) The average hydrogenation rate (H) and average vinyl bond amount (V) are calculated using the following formulas: Average Hydrogenation Rate (H) = (Hydrogenation Rate of Copolymer (A)) × (Mass Ratio of Copolymer (A)) + (Hydrogenation Rate of Copolymer (B)) × (Mass Ratio of Copolymer (B)) Average Vinyl Bond Amount (V) = (Vinyl Bond Amount of Copolymer (A)) × (Mass Ratio of Copolymer (A)) + (Vinyl Bond Amount of Copolymer (B)) × (Mass Ratio of Copolymer (B))

(Separation of copolymers (A) and (B) as constituent components of copolymer (X) below) Using GPC [Apparatus: Waters ACQUITY UPLC H-Class; Columns: Waters ACQUITY APC XT900 (2.5 μm, 4.6 × 150 mm), Waters ACQUITY APC XT200 (2.5 μm, 4.6 × 75 mm), Waters ACQUITY APC XT125 (2.5 mm, 4.6 × 75 mm) in series], copolymer (X) was separated into copolymer (A) as the low molecular weight component and copolymer (B) as the high molecular weight component. Chloroform was used as the solvent. Based on the GPC chromatogram, the components of the low molecular weight peak and the high molecular weight peak were separated.

[Materials for Copolymers and Resin Compositions] (Preparation of Hydrogenation Catalyst) In the following embodiments and comparative examples, the hydrogenation catalyst used in the production of copolymers was prepared by the following method. A reaction vessel equipped with a stirring device was first purged with nitrogen, and 1 liter of dried and purified cyclohexane was added. Then, 100 mmol of bis(n-5-cyclopentadienyl)titanium dichloride was added. While stirring thoroughly, a hexane solution containing 200 mmol of trimethylaluminum was added, and the reaction was carried out at room temperature for approximately 3 days. The hydrogenation catalyst was thus obtained.

(Copolymer (A) and copolymer (B)) Copolymers (A1) to (A18), copolymers (B1) to (B22), and copolymer (X1) are manufactured as follows.

<Example 1: Copolymer (A1)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.301 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.7 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 15 minutes. Then, a cyclohexane solution (20% by mass concentration) containing 16 parts by mass of styrene and a cyclohexane solution (20% by mass concentration) containing 64 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Afterward, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following composition: vinyl bond content (Va) 60% by mass, styrene content (Sa) 36% by mass, atactic styrene content (RSa) 20% by mass, styrene block content (BSa) 20% by mass, styrene block molecular weight (MnSa) 6000, and number average molecular weight (Mna) 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A1).

<Example 2: Copolymer (A2)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.337 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.7 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 15 minutes. Next, a cyclohexane solution (20% by mass concentration) containing 80 parts by mass of butadiene was added, and polymerization was carried out for 45 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following properties: vinyl bond content (Va) of 60% by mass, styrene content (Sa) of 20% by mass, atactic styrene content (RSa) of 0% by mass, styrene block content (BSa) of 20% by mass, styrene block molecular weight (MnSa) of 6000, and number average molecular weight (Mna) of 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A2).

<Example 3: Copolymer (A3)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20 wt%) containing 15 parts by weight of styrene was added. Then, 1.28 parts by weight of n-butyllithium (relative to 100 parts by weight of all monomers) and 0.7 mol of N,N,N',N'-tetramethylethylenediamine (relative to 1 mol of n-butyllithium) were added, and polymerization was carried out at 70°C for 20 minutes. Next, a cyclohexane solution (20 wt%) containing 85 parts by weight of butadiene was added, and polymerization was carried out for 30 minutes. Afterward, methanol was added to stop the polymerization reaction. The polymer obtained as described above has a vinyl bond content (Va) of 75% by mass, a styrene content (Sa) of 15% by mass, a random styrene content (RSa) of 0% by mass, a styrene block content (BSa) of 15% by mass, a styrene block molecular weight (MnSa) of 1200, and a number average molecular weight (Mna) of 8,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A3).

<Example 4: Copolymer (A4)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.320 parts by mass of n-butyllithium (relative to 100 parts by mass of all monomers) and 0.6 mol of N,N,N',N'-tetramethylethylenediamine (relative to 1 mol of n-butyllithium) were added, and polymerization was carried out at 70°C for 15 minutes. Next, a cyclohexane solution (20% by mass concentration) containing 8 parts by mass of styrene and a cyclohexane solution (20% by mass concentration) containing 72 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Afterward, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following composition: vinyl bond content (Va) 60% by mass, styrene content (Sa) 28% by mass, atactic styrene content (RSa) 10% by mass, styrene block content (BSa) 20% by mass, styrene block molecular weight (MnSa) 6000, and number average molecular weight (Mna) 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A4).

<Example 5: Copolymer (A5)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20 wt%) containing 20 parts by weight of styrene was added. Then, 1.16 parts by weight of n-butyllithium (relative to 100 parts by weight of all monomers) and 0.7 mol of N,N,N',N'-tetramethylethylenediamine (relative to 1 mol of n-butyllithium) were added, and polymerization was carried out at 70°C for 20 minutes. Next, a cyclohexane solution (20 wt%) containing 8 parts by weight of styrene and a cyclohexane solution (20 wt%) containing 72 parts by weight of butadiene were added, and polymerization was carried out for 45 minutes. Afterward, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following composition: vinyl bond content (Va) 60% by mass, styrene content (Sa) 36% by mass, atactic styrene content (RSa) 20% by mass, styrene block content (BSa) 20% by mass, styrene block molecular weight (MnSa) 1600, and number average molecular weight (Mna) 8,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A5).

<Example 6: Copolymer (A6)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.267 parts by mass of n-butyllithium (relative to 100 parts by mass of all monomers) and 0.7 mol of N,N,N',N'-tetramethylethylenediamine (relative to 1 mol of n-butyllithium) were added, and polymerization was carried out at 70°C for 10 minutes. Next, a cyclohexane solution (20% by mass concentration) containing 16 parts by mass of styrene and a cyclohexane solution (20% by mass concentration) containing 64 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Afterward, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following composition: vinyl bond content (Va) 60% by mass, styrene content (Sa) 36% by mass, atactic styrene content (RSa) 20% by mass, styrene block content (BSa) 20% by mass, styrene block molecular weight (MnSa) 7000, and number average molecular weight (Mna) 35,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A6).

<Example 7: Copolymer (A7)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass) containing 25 parts by mass of styrene was added. Then, 0.320 parts by mass of n-butyllithium (relative to 100 parts by mass of all monomers) and 0.7 mol of N,N,N',N'-tetramethylethylenediamine (relative to 1 mol of n-butyllithium) were added, and polymerization was carried out at 70°C for 10 minutes. Next, a cyclohexane solution (20% by mass) containing 7 parts by mass of styrene and a cyclohexane solution (20% by mass) containing 68 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Afterward, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following composition: vinyl bond content (Va) 60% by mass, styrene content (Sa) 32% by mass, atactic styrene content (RSa) 20% by mass, styrene block content (BSa) 25% by mass, styrene block molecular weight (MnSa) 7500, and number average molecular weight (Mna) 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A7).

<Example 8: Copolymer (A8)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.305 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Next, a cyclohexane solution (20% by mass concentration) containing 16 parts by mass of styrene and a cyclohexane solution (20% by mass concentration) containing 64 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Afterward, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following properties: vinyl bond content (Va) of 30% by mass, styrene content (Sa) of 36% by mass, atactic styrene content (RSa) of 20% by mass, styrene block content (BSa) of 20% by mass, styrene block molecular weight (MnSa) of 6000, and number average molecular weight (Mna) of 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A8).

<Example 9: Copolymer (A9)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.305 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.6 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Next, a cyclohexane solution (20% by mass concentration) containing 16 parts by mass of styrene and a cyclohexane solution (20% by mass concentration) containing 64 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Afterward, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following composition: vinyl bond content (Va) 60% by mass, styrene content (Sa) 36% by mass, random styrene content (RSa) 20% by mass, styrene block content (BSa) 20% by mass, styrene block molecular weight (MnSa) 6000, and number average molecular weight (Mna) 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer. The hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C, and the reaction was stopped midway. The hydrogenation rate of the resulting hydrogenated copolymer is 70%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A9).

<Example 10: Copolymer (A10)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.305 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.6 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (20% by mass concentration) containing 16 parts by mass of styrene and a cyclohexane solution (20% by mass concentration) containing 64 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Subsequently, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following properties: vinyl bond content (Va) of 60% by mass, styrene content (Sa) of 36% by mass, atactic styrene content (RSa) of 20% by mass, styrene block content (BSa) of 20% by mass, styrene block molecular weight (MnSa) of 6000, and number average molecular weight (Mna) of 30,000. Next, 0.3 parts by mass of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (A10).

<Example 11: Copolymer (A11)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.183 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.8 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (20% by mass concentration) containing 14 parts by mass of styrene and a cyclohexane solution (20% by mass concentration) containing 61 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Subsequently, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following properties: vinyl bond content (Va) of 60% by mass, styrene content (Sa) of 36% by mass, random styrene content (RSa) of 20% by mass, styrene block content (BSa) of 20% by mass, styrene block molecular weight (MnSa) of 10,000, and number average molecular weight (Mna) of 50,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and hydrogenation was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A11).

<Example 12: Copolymer (A12)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.279 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.8 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (20% by mass concentration) containing 30 parts by mass of styrene and a cyclohexane solution (20% by mass concentration) containing 50 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Subsequently, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following composition: vinyl bond content (Va) 40% by mass, styrene content (Sa) 50% by mass, atactic styrene content (RSa) 37.5% by mass, styrene block content (BSa) 20% by mass, styrene block molecular weight (MnSa) 6000, and number average molecular weight (Mna) 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and hydrogenation was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A12).

<Example 13: Copolymer (A13)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass) containing 30 parts by mass of styrene was added. Then, 0.305 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.6 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (20% by mass) containing 7 parts by mass of styrene and a cyclohexane solution (20% by mass) containing 63 parts by mass of butadiene were added, and polymerization was carried out for 45 minutes. Subsequently, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following properties: vinyl bond content (Va) of 60% by mass, styrene content (Sa) of 37% by mass, random styrene content (RSa) of 10% by mass, styrene block content (BSa) of 30% by mass, styrene block molecular weight (MnSa) of 9000, and number average molecular weight (Mna) of 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A13).

<Example 14: Copolymer (A14)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Then, 0.337 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.6 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 50 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following properties: vinyl bond content (Va) of 60% by mass, styrene content (Sa) of 20% by mass, atactic styrene content (RSa) of 20% by mass, styrene block content (BSa) of 0% by mass, styrene block molecular weight (MnSa) of 0%, and number average molecular weight (Mna) of 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A14).

<Example 15: Copolymer (B1)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (20 wt%) containing 10 parts by weight of styrene was added. Then, 0.061 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 2 parts by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 8 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B1).

<Example 16: Copolymer (B2)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.061 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 10 parts by mass of butadiene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 34% by mass, a random styrene content (RSb) of 17.5% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B2).

<Example 17: Copolymer (B3)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass) containing 8 parts by mass of styrene was added. Then, 0.116 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 1.0 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (20% by mass) containing 75 parts by mass of butadiene was added, and polymerization was carried out for 60 minutes. Then, a cyclohexane solution (20% by mass) containing 7 parts by mass of styrene was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 10 parts by mass of butadiene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has a vinyl bond content (Vb) of 75% by mass, a styrene content (Sb) of 15% by mass, a random styrene content (RSb) of 0% by mass, a styrene block content (BSb) of 15% by mass, a styrene block molecular weight (MnSb) of 6750, and a number average molecular weight (Mnb) of 90,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm per 100 parts by mass of the copolymer (based on Ti), was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (B3).

<Manufacturing Example 18: Copolymer (B4)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.064 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 7 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 63 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 1 part by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 9 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 28% by mass, a random styrene content (RSb) of 50% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B4).

<Manufacturing Example 19: Copolymer (B5)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.031 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.1 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 7 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 63 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 1 part by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 9 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 30,000, and a number average molecular weight (Mnb) of 300,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B5).

<Example 20: Copolymer (B6)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass) containing 5 parts by mass of styrene was added. Then, 0.044 parts by mass of n-butyllithium (relative to 100 parts by mass of all monomers) and 1 mol of N,N,N',N'-tetramethylethylenediamine (relative to 1 mol of n-butyllithium) were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (20% by mass) containing 8 parts by mass of styrene and a cyclohexane solution (20% by mass) containing 72 parts by mass of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 5 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 10 minutes. Next, a cyclohexane solution containing 1 part by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 9 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 10 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 19% by mass, a random styrene content (RSb) of 10% by mass, a styrene block content (BSb) of 10% by mass, a styrene block molecular weight (MnSb) of 22,000, and a number average molecular weight (Mnb) of 220,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B6).

<Manufacturing Example 21: Copolymer (B7)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.064 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 0.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 2 parts by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 8 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 30% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B7).

<Manufacturing Example 22: Copolymer (B8)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.061 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 16 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 64 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20% by mass) was added, and polymerization was carried out for 10 minutes. Then, methanol was added to stop the polymerization reaction. The polymer obtained as described above has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm per 100 parts by mass of the copolymer (based on Ti), was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (B8).

<Example 23: Copolymer (B9)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.061 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 2 parts by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 8 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer. The hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C, and was stopped midway through the reaction. The hydrogenation rate of the resulting hydrogenated copolymer was 70%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B9).

<Manufacturing Example 24: Copolymer (B10)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.061 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 2 parts by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 8 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (B10).

<Example 25: Copolymer (B11)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20 wt%) containing 10 parts by weight of styrene was added. Then, 0.092 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 10 minutes. Next, a cyclohexane solution containing 2 parts by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 8 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 10,000, and a number average molecular weight (Mnb) of 100,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B11).

<Example 26: Copolymer (B12)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass) containing 10 parts by mass of styrene was added. Then, 0.085 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (20% by mass) containing 16 parts by mass of styrene and a cyclohexane solution (20% by mass) containing 64 parts by mass of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20% by mass) was added, and polymerization was carried out for 10 minutes. Then, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 11,000, and a number average molecular weight (Mnb) of 110,000. Then, 0.3 parts by mass of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer to obtain copolymer (B12).

<Example 27: Copolymer (B13)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.056 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 26 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 44 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 4 parts by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 6 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 40% by mass, a styrene content (Sb) of 50% by mass, a random styrene content (RSb) of 40% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B13).

<Example 28: Copolymer (B14)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution containing 20 parts by mass of styrene (concentration 20% by mass) and a cyclohexane solution containing 80 parts by mass of butadiene (concentration 20% by mass) were added. Then, 0.067 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 60 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 20% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 0% by mass, a styrene block molecular weight (MnSb) of 0, and a number average molecular weight (Mnb) of 150,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, is added to the obtained copolymer, and a hydrogenation reaction is carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer is 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (B14).

<Manufacturing Example 29: Copolymer (B15)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.123 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 2 parts by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 8 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 7000, and a number average molecular weight (Mnb) of 70,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B15).

<Example 30: Copolymer (B16)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.085 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 16 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 64 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20% by mass) was added, and polymerization was carried out for 10 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 11,000, and a number average molecular weight (Mnb) of 110,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm per 100 parts by mass of the copolymer (based on Ti), was added to the obtained copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C. The hydrogenation rate of the resulting hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (B16).

<Example 31: Copolymer (B17)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass) containing 10 parts by mass of styrene was added. Then, 0.085 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (20% by mass) containing 14 parts by mass of styrene and a cyclohexane solution (20% by mass) containing 56 parts by mass of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20 by mass) was added, and polymerization was carried out for 10 minutes. Next, a cyclohexane solution containing 2 parts by mass of styrene (concentration 20 by mass) and a cyclohexane solution containing 8 parts by mass of butadiene (concentration 20 by mass) were added, and polymerization was carried out for 10 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 11,000, and a number average molecular weight (Mnb) of 110,000. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (B17).

<Example 32: Copolymer (B18)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (20 wt%) containing 10 parts by weight of styrene was added. Then, 0.061 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 10 minutes. Then, a cyclohexane solution (20 wt%) containing 16 parts by weight of styrene and a cyclohexane solution (20 wt%) containing 64 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20% by mass) was added, and polymerization was carried out for 10 minutes. Then, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 36% by mass, a random styrene content (RSb) of 20% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Then, 0.3 parts by mass of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer to obtain copolymer (B18).

<Example 33: Copolymer (X1)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 7.4 parts by weight of styrene was added. Then, 0.05 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 9.9 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 39.7 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 5.0 parts by weight of styrene (concentration 20 by weight) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 7.6 parts by weight of styrene (concentration 20 by weight), 0.165 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers, and 0.6 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 6.1 parts by weight of styrene (concentration 20 by weight) and 24.3 parts by weight of butadiene (concentration 20 by weight) were added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner was separated into low molecular weight component (polymer (A)) and high molecular weight component (polymer (B)) by chromatography, and analyzed separately. The results showed that in copolymer (A), the vinyl bond content (Va) was 60% by mass, the styrene content (Sa) was 36% by mass, the atactic styrene content (RSa) was 20% by mass, the styrene block content (BSa) was 20% by mass, the styrene block molecular weight (MnSa) was 3600, and the number average molecular weight (Mna) was 18,000. In copolymer (B), the vinyl bond content (Vb) was 60% by mass, the styrene content (Sb) was 36% by mass, the atactic styrene content (RSb) was 20% by mass, the styrene block content (BSb) was 20% by mass, the styrene block molecular weight (MnSb) was 15,000, and the number average molecular weight (Mnb) was 150,000. Furthermore, the content ratio of copolymer (A) to copolymer (B) is (A)/(B) = 30/70. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer, and the hydrogenation reaction was carried out under conditions of 0.7 MPa hydrogen pressure and 80°C. The hydrogenation rate of the obtained hydrogenated copolymer was 98%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (X1), which is a mixture of copolymer (A) and copolymer (B).

<Manufacturing 34: Copolymer (A15)> Batch polymerization was carried out using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.337 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.7 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 15 minutes. Then, a cyclohexane solution (20% by mass concentration) containing 80 parts by mass of butadiene was added, and polymerization was carried out for 45 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has a vinyl bond content (Va) of 60% by mass, a styrene content (Sa) of 20% by mass, a random styrene content (RSa) of 0% by mass, a styrene block content (BSa) of 20% by mass, a styrene block molecular weight (MnSa) of 6000, and a number average molecular weight (Mna) of 30,000. Subsequently, 0.3 parts by mass of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate relative to 100 parts by mass of the hydrogenated copolymer are added as a stabilizer to obtain copolymer (A15).

<Example 35: Copolymer (A16)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.337 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.7 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 15 minutes. Next, a cyclohexane solution (20% by mass concentration) containing 80 parts by mass of butadiene was added, and polymerization was carried out for 45 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has the following properties: vinyl bond content (Va) of 60% by mass, styrene content (Sa) of 20% by mass, atactic styrene content (RSa) of 0% by mass, styrene block content (BSa) of 20% by mass, styrene block molecular weight (MnSa) of 6000, and number average molecular weight (Mna) of 30,000. Furthermore, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by mass of the copolymer, was added to the obtained copolymer. The hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C, and the hydrogenation reaction was stopped midway. The hydrogenation rate of the resulting hydrogenated copolymer is 30%. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (A16).

<Example 36: Copolymer (A17)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 1.02 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.7 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 15 minutes. Next, a cyclohexane solution (20% by mass concentration) containing 80 parts by mass of butadiene was added, and polymerization was carried out for 45 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has a vinyl bond content (Va) of 60% by mass, a styrene content (Sa) of 20% by mass, a random styrene content (RSa) of 0% by mass, a styrene block content (BSa) of 20% by mass, a styrene block molecular weight (MnSa) of 2000, and a number average molecular weight (Mna) of 10,000. Subsequently, 0.3 parts by mass of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate relative to 100 parts by mass of the hydrogenated copolymer are added as a stabilizer to obtain copolymer (A17).

<Example 37: Copolymer (A18)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass concentration) containing 20 parts by mass of styrene was added. Then, 0.337 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.2 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 15 minutes. Next, a cyclohexane solution (20% by mass concentration) containing 80 parts by mass of butadiene was added, and polymerization was carried out for 45 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained as described above has a vinyl bond content (Va) of 30% by mass, a styrene content (Sa) of 20% by mass, a random styrene content (RSa) of 0% by mass, a styrene block content (BSa) of 20% by mass, a styrene block molecular weight (MnSa) of 6000, and a number average molecular weight (Mna) of 30,000. Subsequently, 0.3 parts by mass of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate relative to 100 parts by mass of the hydrogenated copolymer are added as a stabilizer to obtain copolymer (A18).

<Example 38: Copolymer (B19)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20 wt%) containing 10 parts by weight of styrene was added. Then, 0.061 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 1.3 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 10 parts by mass of butadiene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 34% by mass, a random styrene content (RSb) of 17.5% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (B19).

<Example 39: Copolymer (B20)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass) containing 10 parts by mass of styrene was added. Then, 0.061 parts by mass of n-butyllithium (relative to 100 parts by mass of all monomers) and 1.3 mol of N,N,N',N'-tetramethylethylenediamine (relative to 1 mol of n-butyllithium) were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (20% by mass) containing 14 parts by mass of styrene and a cyclohexane solution (20% by mass) containing 56 parts by mass of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 10 parts by mass of butadiene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 34% by mass, a random styrene content (RSb) of 17.5% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Next, a hydrogenation catalyst prepared as described above, at a concentration of 100 ppm (based on Ti) per 100 parts by weight of the copolymer, was added to the obtained copolymer. The hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80°C, and was stopped midway through the reaction. The hydrogenation rate of the resulting hydrogenated copolymer was 30%. Subsequently, 0.3 parts by weight (based on Ti) of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer to obtain copolymer (B20).

<Example 40: Copolymer (B21)> Batch polymerization was performed using a tank reactor (10 L volume) equipped with a stirrer and jacket. A cyclohexane solution (concentration 20 wt%) containing 10 parts by weight of styrene was added. Then, 0.061 parts by weight of n-butyllithium relative to 100 parts by weight of all monomers and 0.4 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (concentration 20 wt%) containing 14 parts by weight of styrene and a cyclohexane solution (concentration 20 wt%) containing 56 parts by weight of butadiene were added, and polymerization was carried out for 60 minutes. Next, a cyclohexane solution containing 10 parts by mass of styrene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution containing 10 parts by mass of butadiene (concentration 20% by mass) was added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 30% by mass, a styrene content (Sb) of 34% by mass, a random styrene content (RSb) of 17.5% by mass, a styrene block content (BSb) of 20% by mass, a styrene block molecular weight (MnSb) of 15,000, and a number average molecular weight (Mnb) of 150,000. Subsequently, 0.3 parts by weight of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by weight of the hydrogenated copolymer to obtain copolymer (B21).

<Example 41: Copolymer (B22)> Batch polymerization was performed using a tank reactor (10 L capacity) equipped with a stirrer and jacket. A cyclohexane solution (20% by mass) containing 8 parts by mass of styrene was added. Then, 0.116 parts by mass of n-butyllithium relative to 100 parts by mass of all monomers and 0.8 mol of N,N,N',N'-tetramethylethylenediamine relative to 1 mol of n-butyllithium were added, and polymerization was carried out at 70°C for 20 minutes. Then, a cyclohexane solution (20% by mass) containing 75 parts by mass of butadiene was added, and polymerization was carried out for 60 minutes. Then, a cyclohexane solution (20% by mass) containing 7 parts by mass of styrene was added, and polymerization was carried out for 20 minutes. Next, a cyclohexane solution (concentration 20% by mass) containing 10 parts by mass of butadiene was added, and polymerization was carried out for 20 minutes. Afterwards, methanol was added to stop the polymerization reaction. The polymer obtained in the above manner has a vinyl bond content (Vb) of 60% by mass, a styrene content (Sb) of 15% by mass, a random styrene content (RSb) of 0% by mass, a styrene block content (BSb) of 15% by mass, a styrene block molecular weight (MnSb) of 6750, and a number average molecular weight (Mnb) of 90,000. Then, 0.3 parts by mass of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was added as a stabilizer relative to 100 parts by mass of the hydrogenated copolymer to obtain copolymer (B22).

<Manufacturing Example 42: Polyphenylene Ether (PPE)> As a polar resin, polyphenylene ether-based resin (PPE) is polymerized in the following manner. A 1.5-liter jacketed reactor, equipped with an oxygen-containing gas injector at the bottom, a stirring turbine, and baffles, and with a reflux condenser on the vent gas line at the top of the reactor, was filled with the following: 0.2512 g of copper chloride dihydrate, 1.1062 g of 35% hydrochloric acid, 3.6179 g of di-n-butylamine, 9.5937 g of N,N,N',N'-tetramethylpropanediamine, 211.63 g of methanol, 493.80 g of n-butanol, and 180.0 g of 2,6-dimethylphenol containing 5 moles of 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane. The solvent composition by mass ratio was n-butanol:methanol = 70:30. Next, while stirring vigorously, oxygen was introduced into the reactor via an injector at a rate of 180 ml/min, while the polymerization temperature was maintained at 40°C by using a heat transfer medium through the jacket. The polymerization liquid gradually took on the form of a slurry. When the polyphenylene ether reached the desired average molecular weight, the introduction of oxygen-containing gas was stopped, and the resulting polymerization mixture was heated to 50°C. Then, hydroquinone (a reagent manufactured by Wako Pure Chemical Industries Co., Ltd.) was added little by little, and the temperature was maintained at 50°C until the slurry-like polyphenylene ether turned white. Next, 720 g of a methanol solution containing 6.5% by mass of 36% hydrochloric acid was added, followed by filtration and repeated washing with methanol to obtain wet polyphenylene ether. Then, it was vacuum dried at 100°C to obtain dried polyphenylene ether. The ηsp/c was 0.103 dl/g, and the yield was 97%. ηsp/c was determined by preparing a 0.5 g/dl chloroform solution of the above polyphenylene ether and using a Ubbelohde viscometer to calculate the reducing viscosity (ηsp/c) at 30°C. The unit is dl/g. The obtained polyphenylene ether was modified as follows: 152.5 g of polyphenylene ether and 152.5 g of toluene were mixed and heated to approximately 85°C. Next, 2.1 g of dimethylaminopyridine was added. At the point when the solid was completely dissolved, 18.28 g of methacrylic anhydride was slowly added. The resulting solution was continuously mixed while being maintained at 85°C for 3 hours. The solution was then cooled to room temperature to obtain a toluene solution of methacrylate-terminated polyphenylene ether. To the obtained toluene solution, 1000 mL of methanol at 10°C was added dropwise in a 3 L cylindrical SUS container equipped with a homogenizer for stirring. The resulting powder was filtered, washed with methanol, and dried under nitrogen at 85°C for 18 hours.

[Examples and Comparative Examples of Using PPE as a Curing Resin] (Examples 1-25, Examples 30-34), (Comparative Examples 1-8) Resin compounds were prepared using the following components and according to the following preparation method.

<Copolymer (A)> Copolymers (A1) to (A14) produced in Examples (1) to (14) Copolymers (A15) to (A18) produced in Examples (34) to (37) Styrene-butadiene copolymer ("Ricon100 (product name)", manufactured by CRAY VALLEY, styrene: 25% by mass, butadiene: 75% by mass, 1,2-vinyl in butadiene: 70%, number average molecular weight 4500, block styrene content: 0% by mass, hydrogenation rate: 0%) <Copolymer (B)> Copolymers (B1) to (B18) produced in Examples (15) to (32) Copolymers (B19) to (B22) produced in Examples (38) to (41) <Mixture of copolymer (A) and copolymer (B)> Copolymer (X1) produced in Example (33) <Component (I): Hardening Resin> PPE produced in Example 42 <Component (II): Free Radical Initiator> Perbutyl P (manufactured by Nippon Oil Co., Ltd.) <Component (III): Hardener> Triallyl Isocyanurate (TAIC ^™ ) (manufactured by Mitsubishi Chemical Co., Ltd.)

(Preparation of Resin Compound and Varnish) Using copolymers (A), (B), and (X) from manufacturing examples (1) to (41), and using components (I), (II), and (III) as shown in the table below, each component is weighed and placed in a container. The mixture is dissolved and stirred in toluene (manufactured by Wako Junya Co., Ltd.) to prepare a varnish containing the resin compound. When making the film, the viscosity is adjusted by adding toluene. At this time, the concentration of the resin compound in the varnish is adjusted to 40-60% by mass.

(Preparation of Prepreg Using Varnish and Cured Prepreg) A varnish of a resin composition prepared according to the composition shown in the table below was impregnated into a glass substrate (L2116, #2116 type, "L glass", manufactured by Asahi Kasei Corporation). The substrate was then heated and dried at 130°C for 50 minutes to obtain a prepreg. Six prepregs were stacked together and laminated. The temperature was increased to 200°C at a rate of 5°C/min. The substrate was then heated and pressurized at 200°C for 2 hours and under a pressure of 3 MPa to obtain a cured prepreg with a thickness of 0.7 mm.

(Evaluation Criteria for Examples 1-25, 30-34, and Comparative Examples 1-8) <(1) Varnish Solubility> Resin compositions prepared according to the following table were added to toluene at solid content concentrations of 40% by mass and 60% by mass, respectively, and stirred at 40°C for 120 minutes. The solutions were used as evaluation samples and evaluated according to the following three stages. [Evaluation Criteria] ○: No dissolution residue was observed in both solutions with solid content concentrations of 40% by mass and 60% by mass. Δ: No dissolution residue was observed only in the solution with a solid content concentration of 40% by mass. ×: Dissolution residue was observed in both solutions.

<(2) Varnish Storage Stability> Observe the condition of the varnishes from the above-mentioned embodiments and comparative examples when they are left to stand at 30°C/50%RH. Evaluate according to the following criteria for the number of days until the occurrence of delamination and/or the precipitation of gel-like components, and whether or not they are present. "-" in the table indicates that the varnish was not evaluated due to dissolution residues generated during its production. [Evaluation Criteria] ◎: More than 720 hours (including no precipitation) ○: 360 to less than 720 hours Δ: 24 to 360 hours ×: Less than 24 hours

<(3) Dielectric Properties> The dielectric loss factor of the prepreg obtained at 10 GHz was determined by the cavity resonant method. A network analyzer (N5230A, manufactured by Agilent Technologies) and a cavity resonator (CP series, manufactured by Kanto Electronics Applications Development Co., Ltd.) were used as the measuring devices. The test samples were 2.6 mm wide × 80 mm long test pieces cut from the prepreg as described in the above-described manufacturing method. The difference in dielectric loss factor and dielectric constant between Comparative Example 8 (without copolymer (A) and copolymer (B)) and each embodiment or comparative example (Comparative Example 8 – Embodiment or Comparative Example) was evaluated. "-" in the table indicates that solvent residue occurred during the preparation of the varnish and could not be evaluated. [Evaluation Criteria] Dielectric Loss Factor (Df) ◎: 0.0014 or higher ○: 0.0012 or higher but less than 0.0014 Δ: 0.0011 or higher but less than 0.0012 ×: Less than 0.0011 Dielectric Constant (Dk) ◎: 0.25 or higher ○: 0.15 or higher but less than 0.25 Δ: 0.1 or higher but less than 0.15 ×: Less than 0.1

<(4) Heat Resistance (Glass Transition Temperature: Tg)> The dynamic viscoelasticity of the resin composition was measured, and the temperature at which tanδ reaches its maximum was determined as the glass transition temperature (Tg). A higher Tg indicates higher strength over a wider temperature range. The measuring apparatus used was an ARES (manufactured by TA Instruments, trade name). The hardened prepreg was cut into pieces approximately 40 mm long, 10 mm wide, and 0.7 mm thick. Measurements were performed at a frequency of 10 rad/s and a measurement temperature range of -150 to 270°C in torsion mode. Evaluation was conducted using the difference in Tg between Comparative Example 8 (containing neither copolymer (A) nor copolymer (B)) and each embodiment or comparative example (Comparative Example 8 – Embodiments or Comparative Examples). "-" in the table indicates that solvent residue occurred during the production of the varnish and could not be evaluated. [Evaluation Criteria] ◎: Less than 10℃ ○: 10℃ or higher but less than 25℃ Δ: 25℃ or higher but less than 40℃ ×: 40℃ or higher

<(5) Adhesion to Copper Foil (Peel Strength)> The following resin compositions were coated onto a polyimide film. After the solvent was dried and removed, a copper foil with a thickness of 35 μm was overlapped and laminated at 100°C and 1 MPa for 2 minutes to produce a laminate comprising a polyimide film, resin composition, and copper foil. The laminate was heated at 180°C for 1 hour to harden the resin composition. The hardened laminate was then used to test adhesion samples. A 1 cm wide slit was cut into the above-mentioned laminate. The copper foil was peeled off at a 90° angle at a tensile speed of 50 mm/min to test the peel strength. A higher peel strength value indicates better adhesion to the copper foil. The test results were evaluated according to the following criteria. "-" in the table indicates that solvent residue occurred during the preparation of the varnish and could not be evaluated. [Evaluation Criteria] ◎: 0.8 N/mm or higher ○: 0.6 N/mm or higher but less than 0.8 N/mm Δ: 0.4 N/mm or higher but less than 0.6 N/mm ×: Less than 0.4 N/mm

<(6) Crack Resistance> The resin composition obtained above was impregnated and coated onto a low-dielectric glass cloth with a thickness of 0.069 mm. The cloth was dried at 165°C for 5 minutes using a dryer (pressure-resistant explosion-proof steam dryer, manufactured by Takasugi Manufacturing Co., Ltd.) to obtain a prepreg with a resin composition content of 30% by mass. Two pieces of the prepreg were overlapped, and 12 μm copper foil (3EC-M3-VLP, manufactured by Mitsui Metal Mining Co., Ltd.) was placed on both sides. The cloth was then vacuum-pressurized at a pressure of 30 kg/ ^cm² and a temperature of 210°C for 150 minutes to obtain a copper foil laminate (metal foil laminate) with a thickness of 0.2 mm.

Two copper foil laminates were stacked together to form a copper foil laminate. A 0.1 mm thick aluminum foil was placed on top of the laminate, and a 1.5 mm thick paper-based phenolic resin laminate (manufactured by FUTAMURA CHEMICAL, FL-101) was placed below it. Using a 0.2 mm diameter drill bit (manufactured by Hitachi Via Mechanics, ND-1V212), five pilot holes were made at arbitrary locations under the conditions of a speed of 160 krpm, a feed speed of 2 m/min, and a chip load of 12.5 μm/rev. The presence or absence of cracks was evaluated by SEM observation.

[Presence or Absence of Cracks] The presence or absence of cracks at the bottom of the five guide holes was observed based on SEM images. Those with fewer cracks were considered to have good open-hole workability and were evaluated as follows: Furthermore, "-" in the table indicates that solvent residue occurred during the varnish manufacturing process and could not be evaluated. ○: No cracks Δ: Slight residual cracks, but the number of cracks is reduced compared to Comparative Example 8, which does not contain copolymer (A) and copolymer (B). ×: Cracks are present, and the number of cracks is equal to or greater than that of Comparative Example 8, which does not contain copolymer (A) and copolymer (B).

The evaluation results of Examples 1-25, 30-34, and Comparative Examples 1-8 are shown in the table below. Furthermore, in the following examples and comparative examples, the polymer blocks constituting the copolymers are as follows: a, d: Polymer blocks with vinyl aromatic monomers as the main component b1, b2, e: Random polymer blocks containing both vinyl aromatic monomers and conjugated diene monomers c1, c2, f: Polymer blocks with conjugated diene monomers as the main component

Furthermore, in the table below, the blending amounts of copolymer (A) and copolymer (B) are mass fractions (mass %) relative to the total amount (100 mass %) of copolymer (A) and copolymer (B). Also, the blending amounts of components (I) to (III) are parts by mass when the total amount of copolymer (A) and copolymer (B) is set to 100 parts by mass.

[Table 1] Implementation Case Number Implementation Example 1 Implementation Example 2 Implementation Example 3 Implementation Example 4 Implementation Example 5 Implementation Example 6 Low molecular weight A code A1 A2 A2 A2 A3 A4 Structure de df df df df de Number average molecular weight 30000 30000 30000 30000 8000 30000 Vinyl bond content (%) 60 60 60 60 75 60 Styrene content (mass %) 36 20 20 20 15 28 Hydrogenation rate (%) 98 98 98 98 98 98 Styrene block content (mass %) 20 20 20 20 15 20 Polymer B code B1 B2 B2 B2 B3 B4 Structure a-b1-a-b2 a-b1-a-c1 a-b1-a-c1 a-b1-a-c1 a-c1-a-c2 a-b1-a-b2 Number average molecular weight 150000 150000 150000 150000 90000 150000 Vinyl bond content (%) 60 60 60 60 75 60 Styrene content (mass %) 36 34 34 34 15 28 Hydrogenation rate (%) 98 98 98 98 98 98 Styrene block content (mass %) 20 20 20 20 15 20 ΔBS 0 0 0 0 0 0 Mnb/Mna 5.00 5.00 5.00 5.00 11.25 5.00 Average styrene content (mass %) 36 30 33 27 15 28 Average vinyl bond content (%) 60 60 60 60 75 60 Average hydrogenation rate (%) 98 98 98 98 98 98 HV 38 38 38 38 twenty three 38 Copolymer (A) (mass %) 30 30 10 50 30 30 Copolymer (B) (mass %) 70 70 90 50 70 70 PPE (parts by weight) 125 125 125 125 125 125 Triallyl isocyanate (parts by mass) 25 25 25 25 25 25 Perbutyl P (parts by weight) 1.5 1.5 1.5 1.5 1.5 1.5 Varnish solubility ○ ○ Δ ○ ○ ○ Varnish storage stability ◎ ◎ ○ ◎ ○ ◎ Dk ○ ◎ ◎ ○ ◎ ◎ Df ○ ◎ ◎ ○ ◎ ◎ Heat resistance (Tg) ○ ◎ ◎ ○ ○ ◎ Peel strength ○ ◎ ◎ ◎ ◎ ◎ Crack resistance Δ ○ ○ ○ ○ Δ

[Table 2] Implementation Case Number Implementation Example 7 Implementation Example 8 Implementation Example 9 Implementation Example 10 Implementation Example 11 Implementation Example 12 Low molecular weight A code A5 A6 A7 A8 A1 A9 Structure de de de de de de Number average molecular weight 8000 35000 30000 30000 30000 30000 Vinyl bond content (%) 60 60 60 30 60 60 Styrene content (mass %) 36 36 32 36 36 36 Hydrogenation rate (%) 98 98 98 98 98 70 Styrene block content (mass %) 20 20 25 20 20 20 Polymer B code B5 B1 B6 B7 B8 B9 Structure a-b1-a-b2 a-b1-a-b2 a-b1-a-b2 a-b1-a-b2 a-b1-a a-b1-a-b2 Number average molecular weight 300000 150000 220000 150000 150000 150000 Vinyl bond content (%) 60 60 60 30 60 60 Styrene content (mass %) 36 36 19 36 36 36 Hydrogenation rate (%) 98 98 98 98 98 70 Styrene block content (mass %) 20 20 10 20 20 20 ΔBS 0 0 15 0 0 0 Mnb/Mna 37.50 4.29 7.33 5.00 5.00 5.00 Average styrene content (mass %) 36 36 twenty three 36 36 36 Average vinyl bond content (%) 60 60 60 30 60 60 Average hydrogenation rate (%) 98 98 98 98 98 70 HV 38 38 38 68 38 10 Copolymer (A) (mass %) 50 30 30 30 30 30 Copolymer (B) (mass %) 50 70 70 70 70 70 PPE (parts by weight) 125 125 125 125 125 125 Triallyl isocyanate (parts by mass) 25 25 25 25 25 25 Perbutyl P (parts by weight) 1.5 1.5 1.5 1.5 1.5 1.5 Varnish solubility ○ ○ ○ ○ ○ ○ Varnish storage stability ◎ ◎ ○ ◎ ◎ Δ Dk ◎ ○ ◎ ○ ○ ○ Df ◎ ○ ◎ ○ ○ ○ Heat resistance (Tg) ◎ ○ ◎ ○ ○ ◎ Peel strength ○ ○ ○ ○ Δ ○ Crack resistance Δ Δ Δ Δ Δ Δ

[Table 3] Implementation Case Number Implementation Example 13 Implementation Example 14 Implementation Example 15 Implementation Example 16 Implementation Example 17 Implementation Example 18 Low molecular weight A code A10 A1 X1 A4 A12 A10 Structure de de de de de de Number average molecular weight 30000 30000 18000 30000 30000 30000 Vinyl bond content (%) 60 60 60 60 40 60 Styrene content (mass %) 36 36 36 28 50 36 Hydrogenation rate (%) 0 98 98 98 98 0 Styrene block content (mass %) 20 20 20 20 20 20 Polymer B code B10 B11 X1 B13 B4 B12 Structure a-b1-a-b2 a-b1-a-b2 a-b1-a-b2 a-b1-a-b2 a-b1-a-b2 a-b1-a Number average molecular weight 150000 100000 150000 150000 150000 110000 Vinyl bond content (%) 60 60 60 40 60 60 Styrene content (mass %) 36 36 36 50 28 36 Hydrogenation rate (%) 0 98 98 98 98 0 Styrene block content (mass %) 20 20 20 20 20 20 ΔBS 0 0 0 0.00 0 0 Mnb/Mna 5.00 3.33 8.33 5.00 5.00 3.67 Average styrene content (mass %) 36 36 36 39 35 36 Average vinyl bond content (%) 60 60 60 50 54 60 Average hydrogenation rate (%) 0 98 98 98 98 0 HV -60 38 38 48 44 -60 Copolymer (A) (mass %) 30 30 30 50 30 30 Copolymer (B) (mass %) 70 70 70 50 70 70 PPE (parts by weight) 125 125 125 125 125 125 Triallyl isocyanate (parts by mass) 25 25 25 25 25 25 Perbutyl P (parts by weight) 1.5 1.5 1.5 1.5 1.5 1.5 Varnish solubility ○ ○ ○ ○ ○ ○ Varnish storage stability Δ ◎ ◎ ◎ ◎ Δ Dk Δ ○ ○ ○ ○ Δ Df Δ Δ ○ ○ ○ Δ Heat resistance (Tg) ◎ Δ ○ ○ ○ Δ Peel strength ○ ◎ ○ ◎ ○ Δ Crack resistance Δ Δ Δ Δ Δ Δ

[Table 4] Implementation Case Number Implementation Example 19 Implementation Example 20 Implementation Example 21 Implementation Example 22 Implementation Example 23 Implementation Example 24 Implementation Example 25 Low molecular weight A code A1 A10 A10 A2 A2 A2 A2 Structure de de de df df df df Number average molecular weight 30000 30000 30000 30000 30000 30000 30000 Vinyl bond content (%) 60 60 60 60 60 60 60 Styrene content (mass %) 36 36 36 20 20 20 20 Hydrogenation rate (%) 98 0 0 98 98 98 98 Styrene block content (mass %) 20 20 20 20 20 20 20 Polymer B code B16 B17 B18 B2 B2 B2 B2 Structure a-b1-a a-b1-a-b2 a-b1-a a-b1-a-c1 a-b1-a-c1 a-b1-a-c1 a-b1-a-c1 Number average molecular weight 110000 110000 150000 150000 150000 150000 150000 Vinyl bond content (%) 60 60 60 60 60 60 60 Styrene content (mass %) 36 36 36 34 34 34 34 Hydrogenation rate (%) 98 0 0 98 98 98 98 Styrene block content (mass %) 20 20 20 20 20 20 20 ΔBS 0 0 0 0 0 0 0 Mnb/Mna 3.67 3.67 5.00 5.00 5.00 5.00 5.00 Average styrene content (mass %) 36 36 36 30 30 30 30 Average vinyl bond content (%) 60 60 60 60 60 60 60 Average hydrogenation rate (%) 98 0 0 98 98 98 98 HV 38 -60 -60 38 38 38 38 Copolymer (A) (mass %) 30 30 30 30 30 30 30 Copolymer (B) (mass %) 70 70 70 70 70 70 70 PPE (parts by weight) 125 125 125 - 125 125 - Triallyl isocyanate (parts by mass) 25 25 25 25 - 25 25 Perbutyl P (parts by weight) 1.5 1.5 1.5 1.5 1.5 - - Varnish solubility ○ ○ ○ ○ ○ ○ ○ Varnish storage stability ◎ Δ Δ ○ ◎ ○ ◎ Dk ○ Δ Δ ◎ ◎ ◎ ◎ Df Δ Δ Δ ◎ ◎ ◎ ◎ Heat resistance (Tg) Δ Δ ○ Δ Δ Δ Δ Peel strength Δ ◎ Δ ○ ○ ○ ○ Crack resistance Δ Δ Δ Δ ○ ○ Δ

[Table 5] Implementation Case Number Implementation Example 30 Implementation Example 31 Implementation Example 32 Implementation Example 33 Implementation Example 34 Low molecular weight A code A15 A16 A17 A18 A17 Structure df df df df df Number average molecular weight 30000 30000 10000 30000 10000 Vinyl bond content (%) 60 60 60 30 60 Styrene content (mass %) 20 20 20 20 20 Hydrogenation rate (%) 0 30 0 0 0 Styrene block content (mass %) 20 20 20 20 20 Polymer B code B19 B20 B19 B21 B22 Structure a-b1-a-c1 a-b1-a-c1 a-b1-a-c1 a-b1-a-c1 a-c1-a-c2 Number average molecular weight 150000 150000 150000 150000 90000 Vinyl bond content (%) 60 60 60 30 60 Styrene content (mass %) 34 34 34 34 15 Hydrogenation rate (%) 0 30 0 0 0 Styrene block content (mass %) 20 20 20 20 15 ΔBS 0 0 0 0 5 Mnb/Mna 5.00 5.00 15.00 5.00 9.00 Average styrene content (mass %) 30 30 30 27 17 Average vinyl bond content (%) 60 60 60 30 60 Average hydrogenation rate (%) 0 30 0 0 0 HV -60 -30 -60 -30 -60 Copolymer (A) (mass %) 30 30 30 50 30 Copolymer (B) (mass %) 70 70 70 50 70 PPE (parts by weight) 125 125 125 125 125 Triallyl isocyanate (parts by mass) 25 25 25 25 25 Perbutyl P (parts by weight) 1.5 1.5 1.5 1.5 1.5 Varnish solubility ○ ○ ○ ○ ○ Varnish storage stability Δ Δ Δ Δ Δ Dk Δ Δ Δ Δ Δ Df Δ Δ Δ Δ Δ Heat resistance (Tg) ◎ ◎ ◎ ◎ ○ Peel strength ◎ ◎ ◎ ◎ ◎ Crack resistance ○ ○ ○ ○ ○

[Table 6] Implementation Case Number Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 Comparative example 8 Low molecular weight A code RICON100 - A11 A12 A13 A14 A1 - Structure e without de de de e de - Number average molecular weight 4500 - 50000 30000 30000 30000 30000 - Vinyl bond content (%) 70 - 60 40 60 60 60 - Styrene content (mass %) 25 - 36 50 37 20 28 - Hydrogenation rate (%) 0 - 98 98 98 98 98 - Styrene block content (mass %) 0 - 20 20 30 0 20 - Polymer B code - B1 B1 B13 B14 B1 B15 - Structure without a-b1-a-b2 a-b1-a-b2 a-b1-a-b2 b1 a-b1-a-b2 a-b1-a-b2 - Number average molecular weight - 150000 150000 150000 150000 150000 70000 - Vinyl bond content (%) - 60 60 40 60 60 60 - Styrene content (mass %) - 36 36 50 20 36 36 - Hydrogenation rate (%) - 98 98 98 98 98 98 - Styrene block content (mass %) - - 20 20 0 20 20 - ΔBS - - 0.00 0.00 30.00 - 0.00 - Mnb/Mna - - 3.00 5.00 5.00 - 2.33 - Average styrene content (mass %) - - 36 50 25 31 34 - Average vinyl bond content (%) - - 60 40 60 60 60 - Average hydrogenation rate (%) - - 98 98 98 98 98 - HV - - 38 58 38 38 38 - Copolymer (A) (mass %) 30 30 50 30 30 30 30 0 Copolymer (B) (mass %) 70 70 50 70 70 70 70 0 PPE (parts by weight) 125 125 125 125 125 125 125 125 Triallyl isocyanate (parts by mass) 25 25 25 25 25 25 25 25 Perbutyl P (parts by weight) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Varnish solubility ○ × × ○ × × ○ ○ Varnish storage stability Δ - - ◎ - - ○ - Dk × - - × - - ○ - Df × - - × - - Δ - Heat resistance (Tg) × - - Δ - - × - Peel strength × - - Δ - - ◎ - Crack resistance × - - Δ - - Δ -

The dielectric properties and heat resistance of the cured products of copolymer (A) and copolymer (B) in the embodiments are clearly well balanced. It is understood that the cured products of the present invention are suitable for use as printed circuit boards using glass cloth and metal laminates.

[Examples and Comparative Examples of Using Epoxy/PPE as Curing Resins] (Examples 26-29), (Comparative Examples 9-11) Resin compounds were prepared using the following components and according to the following preparation method.

<Copolymer (A)> Copolymers (A1), (A2), and (A5) prepared in Examples 1, 2, and 5 Styrene-butadiene copolymer ("Ricon100 (product name)", manufactured by CRAY VALLEY Corporation, styrene: 25% by mass, butadiene: 75% by mass, 1,2-vinyl in butadiene: 70%, number average molecular weight 4500, block styrene content: 0% by mass, hydrogenation rate: 0%) <Copolymer (B)> Copolymers (B1) to (B3) prepared in Examples 15-17. <Component (I): Hardening Resin> HP-4710 (Manufactured by DIC Corporation) YP-50S (Manufactured by JITAC Chemicals) PPE produced in Example 42 <Component (II): Free Radical Initiator> Perbutyl P (Manufactured by Nippon Oil Co., Ltd.) <Component (III): Hardener> HPC-8000-65T (Manufactured by DIC Corporation) <Component (IV): Additive> 4-Dimethylaminopyridine (TCI)

<Preparation of Resin Compounds and Varnish> The component ratios and properties are shown in the table below. First, substances other than HPC-8000-65T (manufactured by DIC) were added to toluene, stirred, and dissolved to prepare a varnish with a concentration of 20% to 50% by mass. HPC-8000-65T (manufactured by DIC) was prepared by using methyl ethyl ketone (a premium product manufactured by Wako Pure Pharmaceutical Co., Ltd.) as a solvent to prepare a 50% by mass phenolic hardener solution, which was then added to the above varnish and stirred to prepare the varnish. The varnish was applied to a demolded Kapton film at a speed of 30 mm/s, and then dried at 100°C for 30 minutes under nitrogen using a blower dryer to obtain the film. The obtained membrane was cured at 200°C for 90 minutes under a nitrogen atmosphere using a forced-air dryer to obtain a cured membrane. The cured membrane was then provided as an evaluation sample.

(Evaluation criteria in Examples 26-29 and Comparative Examples 9-11) <(1) Varnish Solubility> Resin compositions prepared according to the following table were added to toluene at solid concentrations of 30% by mass and 50% by mass, respectively, and stirred at 40°C for 120 minutes to obtain solutions. The solutions were evaluated in three stages. [Evaluation Criteria] ○: No dissolution residue was observed in both the 30% by mass and 50% by mass solutions. Δ: No dissolution residue was observed only in the 30% by mass solution. ×: Dissolution residue was observed in both solutions.

<(2) Dielectric Properties> The dielectric loss factor of the obtained cured film at 10 GHz was measured using the cavity resonant method. A network analyzer (N5230A, manufactured by Agilent Technologies) and a cavity resonator (CP series, manufactured by Kanto Electronics Applications Development Co., Ltd.) were used as the measuring devices. The test samples were 2.6 mm wide × 80 mm long test pieces cut from the cured film described in the above adjustment method. The difference in dielectric loss factor and dielectric constant between Comparative Example 11 (without copolymer (A) and copolymer (B)) and each embodiment or comparative example (Comparative Example 11 – Embodiment or Comparative Example) was used for evaluation. Furthermore, "-" in the table indicates that solvent residue occurred during the preparation of the varnish and could not be evaluated. [Evaluation Criteria] Dielectric Loss Factor (Df) ◎: 0.0013 or higher ○: 0.0010 or higher but less than 0.0013 Δ: 0.0005 or higher but less than 0.0010 ×: Less than 0.0005 Dielectric Constant (Dk) ◎: 0.4 or higher ○: 0.3 or higher but less than 0.4 Δ: 0.2 or higher but less than 0.3 ×: Less than 0.2

The block structures are represented in the table below as follows: a, d: Polymer blocks with vinyl aromatic monomers as the main component b1, b2, e: Random polymer blocks containing both vinyl aromatic monomers and conjugated diene monomers c1, c2, f: Polymer blocks with conjugated diene monomers as the main component

Furthermore, in the table below, the blending amounts of copolymer (A) and copolymer (B) are mass fractions (mass %) relative to the total amount (100 mass %) of copolymer (A) and copolymer (B). Also, the blending amounts of components (I) to (IV) are parts by mass when the total amount of copolymer (A) and copolymer (B) is set to 100 parts by mass.

[Table 7] Implementation Case Number Implementation Example 26 Implementation Example 27 Implementation Example 28 Implementation Example 29 Low molecular weight A code A1 A2 A2 A5 Structure de df df df Number average molecular weight 30000 30000 30000 8000 Vinyl bond content (%) 60 60 60 75 Styrene content (mass %) 36 20 20 15 Hydrogenation rate (%) 98 98 98 98 Styrene block content (mass %) 20 20 20 15 Polymer B code B1 B2 B2 B3 Structure a-b1-a-b2 a-b1-a-c1 a-b1-a-c1 a-c1-a-c2 Number average molecular weight 150000 150000 150000 90000 Vinyl bond content (%) 60 60 60 60 Styrene content (mass %) 36 34 34 15 Hydrogenation rate (%) 98 98 98 98 Styrene block content (mass %) 20 20 20 15 ΔBS 0 0 0 0 Mnb/Mna 5.00 5.00 5.00 11.25 Average styrene content (wt%) 36 30 30 15 Average vinyl bond content (%) 60 60 60 65 Average hydrogenation rate (%) 98 98 98 98 HV 38 38 38 34 Copolymer (A) (mass %) 30 30 30 30 Copolymer (B) (mass %) 70 70 70 70 Epoxy resin (HP-4710) (parts by weight) 180 180 180 180 PPE (parts by weight) 270 270 270 270 Phenolic resin (HPC-8000-65T) (parts by weight) 355 355 355 355 Phenoxy resin (YP-50S) (parts by weight) 90 90 90 90 4-Dimethylaminopyridine (parts by mass) 8.9 8.9 8.9 8.9 Peroxide (Perbutyl P) (parts by weight) 5 5 5 5 Varnish solubility ○ ○ ○ Δ Dk ○ ○ ○ ○ Df ○ ○ ○ ○

[Table 8] Implementation Case Number Comparative example 9 Comparative example 10 Comparative example 11 Low molecular weight A code RICON100 - - Structure d without without Number average molecular weight 4500 - - Vinyl bond content (%) 70 - - Styrene content (mass %) 25 - - Hydrogenation rate (%) 0 - - Polymer B code - B1 Structure without a-b1-a~b2 without Number average molecular weight - 150000 - Vinyl bond content (%) - 60 - Styrene content (mass %) - 36 - Hydrogenation rate (%) - 98 - ΔBS - - - Mna/Mnb - - - Average styrene content (mass %) - - - Average vinyl bond content (%) - - - Average hydrogenation rate (%) - - - HV - - - Copolymer (A) (mass %) 30 30 30 Copolymer (B) (mass %) 70 70 70 Epoxy resin (HP-4710) (parts by weight) 180 180 180 PPE (parts by weight) 270 270 270 Phenolic resin (HPC-8000-65T) (parts by weight) 355 355 355 Phenoxy resin (YP-50S) (parts by weight) 90 90 90 4-Dimethylaminopyridine (parts by mass) 8.9 8.9 8.9 Peroxide (Perbutyl P) (parts by weight) 5 5 5 Varnish solubility ○ × ○ Dk × - - Df × - -

The cured products of copolymers (A) and (B) in the embodiments clearly demonstrate excellent dielectric properties. Therefore, the cured products of this invention are suitable for use in printed circuit boards employing glass cloth and metal laminates. [Industrial Applicability]

The resin composition and hardener of this invention are industrially viable as materials for films, prepregs, electronic circuit boards, and next-generation communication boards.

Claims (18)

A resin composition comprising: a copolymer (A) having vinyl aromatic monomer units and conjugated diene monomer units, a copolymer (B) having vinyl aromatic monomer units and conjugated diene monomer units, and at least one component selected from the group consisting of components (I) to (III) below, and the resin composition satisfies the following <conditions (1)> to <conditions (7)>: Component (I): curing resin (excluding copolymer (A) and copolymer (B)) Component (II): free radical initiator Component (III): curing agent (excluding component (I)) <condition (1)>: the number average molecular weight of the above copolymer (A) is 40,000 or less, <condition (2)>: The copolymer (A) described above has at least one polymer block with a vinyl aromatic monomer as the main component. <Condition (3)>: The copolymer (B) described above has at least one polymer block with a vinyl aromatic monomer as the main component. <Condition (4)>: The number average molecular weight of the copolymer (B) described above is 80,000 or more. <Condition (5)>: The difference (ΔBS) between the content (BSa) (mass %) of the polymer block with a vinyl aromatic monomer as the main component in the copolymer (A) and the content (BSb) (mass %) of the polymer block with a vinyl aromatic monomer as the main component in the copolymer (B) described above satisfies the following relationship: ΔBS＝｜BSa－BSb｜≦20 <Condition (6)>: The average content of vinyl aromatic monomer units in the above copolymers (A) and (B) is 40% by mass or less. <Condition (7)>: The content (BSb) of polymer blocks in the above copolymer (B) with vinyl aromatic monomer units as the main component is 10% by mass or more. The resin composition of claim 1, wherein the average hydrogenation rate (H)(%) and average vinyl bond content (V)(%) of the unsaturated double bonds derived from conjugated diene compounds contained in copolymers (A) and (B) satisfy the following relationship: V＋10≦H. As in claim 1, the copolymer (B) is a block copolymer with the general structure represented by a1-b1-a2-c1, a1-b1-a2-b2, a1-c1-a2-c2, and a1-c1-a2-b1. Blocks a1 and a2 are polymer blocks with vinyl aromatic monomers as the main component. Blocks b1 and b2 are random polymer blocks comprising vinyl aromatic monomers and conjugated diene monomers. Blocks c1 and c2 are polymer blocks with conjugated diene monomers as the main component. For example, in the resin composition of claim 1, the ratio (Mnb/Mna) of the number average molecular weight (Mnb) of the copolymer (B) to the number average molecular weight (Mna) of the copolymer (A) is greater than 4. The resin composition of claim 1, wherein the copolymer (A) is a block copolymer represented by the general structural formula d-f, where d is a polymer block with vinyl aromatic monomers as the main component, and f is a polymer block with conjugated diene monomers as the main component. A hardened compound, which is a hardened resin composition as described in any of claims 1 to 5. A printed wiring board comprising the hardened material as claimed in claim 6. A resin film comprising the hardened material as claimed in claim 6. A prepreg, which is a composite of a substrate and a resin composition as claimed in any of claims 1 to 5. A prepreg, which is a composite of a substrate and a hardener as claimed in claim 6. For example, the prepreg in claim 9, wherein the substrate is glass cloth. For example, the prepreg in claim 10, wherein the substrate is glass cloth. A laminate comprising: a cured resin film as claimed in item 8, and a metal foil. A laminate comprising: a cured prepreg as claimed in claim 9, and a metal foil. A laminate comprising: a cured prepreg as claimed in claim 10, and a metal foil. A printed wiring board comprising a resin film as claimed in claim 8. A printed wiring board comprising a prepreg as claimed in claim 11. A printed wiring board comprising a prepreg as claimed in claim 12.