CN116693781A - Block copolymer, resin composition, cured product, resin film, prepreg, laminate, and material for electronic circuit board - Google Patents

Abstract

The present invention relates to block copolymers, resin compositions, cured products, resin films, prepregs, laminates, and materials for electronic circuit boards, and aims to provide a block copolymer with a low dielectric constant. In addition, it is a cured product with a low dielectric loss tangent and excellent strength characteristics. A block copolymer comprising: a polymer block (A) mainly composed of a vinyl aromatic monomer unit; and a polymer block (B) mainly composed of a conjugated diene monomer unit; and /or a polymer block (C) composed of a vinyl aromatic monomer unit and a conjugated diene monomer unit, and the block copolymer satisfies the following conditions (i) to (ii). <Condition (i)> The block copolymer has a weight average molecular weight of 35,000 or less. <Condition (ii)> The content of the vinyl aromatic monomer unit in the said block copolymer is 55 mass % or more and 95 mass % or less.

Description

Block copolymers, resin compositions, cured products, resin films, prepregs, laminates, and materials for electronic circuit boards

Technical Field

The present invention relates to a block copolymer, a resin composition, a cured product, a resin film, a prepreg, a laminate, and a material for an electronic circuit board.

Background Art

In recent years, with the remarkable progress of information network technology and the expansion of services using information networks, electronic devices are required to have larger information capacity and higher processing speed.

In order to meet these requirements, various substrate materials such as printed circuit boards and flexible circuit boards are required to have low dielectric loss.

In the past, in order to obtain materials with low dielectric loss, various materials such as resin cured products with thermosetting resins such as epoxy resins or thermoplastic resins such as polyphenylene ether resins as main components having low dielectric constants and/or low dielectric loss tangents and excellent mechanical properties such as strength have been studied and disclosed.

However, the conventionally disclosed materials still have room for improvement from the viewpoint of low dielectric constant and low dielectric loss tangent, and when they are used for printed circuit boards, there are problems of limited information volume and processing speed.

In order to improve this problem, various rubber components have been proposed as modifiers for the above-mentioned thermosetting resins or thermoplastic resins.

For example, Patent Document 1 discloses, as a modifier for lowering the dielectric loss tangent and the dielectric constant of polyphenylene ether resin, at least one elastomer selected from the group consisting of block copolymers of vinyl aromatic compounds and olefin compounds and hydrogenated products thereof, and homopolymers of vinyl aromatic compounds.

Patent Document 2 discloses a styrene-based elastomer as a modifier for lowering the dielectric loss tangent and the dielectric constant of an epoxy resin.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2021-147486

Patent Document 2: Japanese Patent Application Publication No. 2020-15861

Summary of the invention

Problems to be solved by the invention

However, the resin compositions using the modifiers disclosed in Patent Documents 1 and 2 have problems in that the dielectric constant and dielectric loss tangent are not sufficiently reduced, and the strength is reduced by the addition of the modifier, so that sufficient strength cannot be obtained.

Therefore, an object of the present invention is to provide a block copolymer which can give a cured product having a low dielectric constant and a low dielectric loss tangent and excellent strength characteristics, and a resin composition containing the block copolymer.

Means for solving problems

The present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art and have found that a cured product of a resin composition containing a block copolymer having a predetermined structure has a low dielectric constant and a low dielectric loss tangent and is also excellent in strength characteristics, thereby completing the present invention.

That is, the present invention is as follows.

[1]

A block copolymer having:

a polymer block (A) mainly composed of vinyl aromatic monomer units; and

a polymer block (B) mainly composed of a conjugated diene monomer unit and/or a polymer block (C) composed of a vinyl aromatic monomer unit and a conjugated diene monomer unit,

The block copolymer satisfies the following conditions (i) to (ii).

<Condition (i)>

The weight average molecular weight of the block copolymer is 35,000 or less.

<Condition (ii)>

The content of the vinyl aromatic monomer unit in the block copolymer is 55% by mass or more and 95% by mass or less.

[2]

The block copolymer as described in the above [1] further satisfies the following condition (iii).

<Condition (iii)>

The polymer block (B) and/or the polymer block (C) comprises a unit (a) derived from a 1,2-bond and/or a 3,4-bond and a unit (b) derived from a 1,4-bond, and when the total content of the polymer block (B) and/or the polymer block (C) is 100%, the content of the unit (a) derived from a 1,2-bond and/or a 3,4-bond is 80% or less.

[3]

A resin composition comprising:

Component (I): the block copolymer described in [1] or [2] above; and

At least one component selected from the group consisting of the following components (II) to (IV).

Component (II): Free radical initiator

Component (III): Polar resin (excluding component (I))

Component (IV): Curing agent (excluding component (II))

[4]

The resin composition according to the above [3], wherein the component (III) is at least one selected from the group consisting of epoxy resins, polyimide resins, polyphenylene ether resins, liquid crystal polyester resins and fluorine resins.

[5]

A cured product comprising the block copolymer described in [1] or [2] above.

[6]

A cured product, which is a cured product of the resin composition according to [3] or [4] above.

[7]

A resin film comprising the resin composition according to [3] or [4] above.

[8]

A prepreg which is a composite of a substrate and the resin composition described in [3] or [4] above.

[9]

The prepreg according to the above-mentioned [8], wherein the substrate is glass cloth.

[10]

A laminate comprising the resin film according to [7] above and a metal foil.

[11]

A laminate comprising a cured product of the prepreg according to [8] or [9] above and a metal foil.

[12]

A material for an electronic circuit board, comprising the cured product described in [6] above.

Effects of the Invention

According to the present invention, there are provided a block copolymer capable of obtaining a cured product having a low dielectric constant, a low dielectric loss tangent and excellent strength characteristics, and a resin composition containing the block copolymer.

DETAILED DESCRIPTION

A specific embodiment of the present invention (hereinafter referred to as “this embodiment”) will be described in detail below.

It should be noted that the following embodiments are examples for explaining the present invention and are not intended to limit the present invention to the following contents. The present invention can be implemented with various modifications within the scope of the gist.

[Block copolymer]

The block copolymer of the present embodiment comprises: a polymer block (A) mainly composed of vinyl aromatic monomer units (hereinafter sometimes referred to as polymer block (A)); and a polymer block (B) mainly composed of conjugated diene monomer units (hereinafter sometimes referred to as polymer block (B)) and/or a polymer block (C) composed of vinyl aromatic monomer units and conjugated diene monomer units (hereinafter sometimes referred to as polymer block (C)).

The block copolymer of the present embodiment satisfies the following conditions (i) to (ii).

<Condition (i)>

The weight average molecular weight of the block copolymer is 35,000 or less.

<Condition (ii)>

The content of the vinyl aromatic monomer unit in the block copolymer is 55% by mass or more and 95% by mass or less.

According to the block copolymer of the present embodiment, a cured product of a resin composition having a low dielectric constant and a low dielectric loss tangent and also excellent strength characteristics can be obtained.

The conjugated diene monomer unit refers to a structural unit derived from a conjugated diene compound in a polymer block or a block copolymer obtained by polymerizing the conjugated diene compound.

The conjugated diene compound is a diene having a pair of conjugated double bonds.

Examples of the conjugated diene compound include, but are not limited to, 1,3-butadiene, 2-methyl-1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-cyclohexadiene.

Among these, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred. 1,3-Butadiene and isoprene are widely used, easily available, and advantageous in terms of cost, and are easily copolymerized with styrene which is widely used as a vinyl aromatic compound described later.

These compounds may be used alone or in combination of two or more.

Furthermore, the conjugated diene compound may be a compound of biological origin.

The vinyl aromatic monomer unit refers to a structural unit derived from a vinyl aromatic compound in a polymer block or a block copolymer obtained by polymerizing a vinyl aromatic compound.

Examples of the vinyl aromatic compound include, but are not limited to, styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene.

These compounds may be used alone or in combination of two or more.

The block copolymer of this embodiment has a polymer block (A) mainly composed of a vinyl aromatic monomer unit, and a polymer block (B) mainly composed of a conjugated diene monomer unit and/or a polymer block (C) composed of a vinyl aromatic monomer unit and a conjugated diene monomer unit.

That is, it has the polymer block (A) and the polymer block (B), or has the polymer block (A) and the polymer block (C), or has the polymer block (A), the polymer block (B), and the polymer block (C).

The polymer block (A) mainly comprises vinyl aromatic monomer units. The term “mainly” means that the polymer block (A) is substantially composed of vinyl aromatic monomer units and does not intentionally contain other monomers.

The polymer block (B) mainly comprises conjugated diene monomer units. The term “mainly comprises conjugated diene monomer units” means that the polymer block (B) is substantially composed of conjugated diene monomer units and that no monomer other than the conjugated diene monomer units is intentionally added.

The content of the polymer block (A) in the block copolymer of the present embodiment can be measured by a method using a nuclear magnetic resonance apparatus (NMR) (the method described in Y. Tanaka, et al., RUBBER CHEMISTRY and TECHNOLOGY 54, 685 (1981), hereinafter referred to as “NMR method”) using the block copolymer before hydrogenation or the hydrogenated block copolymer after hydrogenation as an analyte.

From the viewpoint of improving the strength of the cured product due to the mutual entanglement of the polymer blocks (A) composed of vinyl aromatic monomer units described later, the content of the polymer blocks (A) in the block copolymer of the present embodiment is preferably 15 to 95% by mass, more preferably 20 to 90% by mass, and even more preferably 25 to 85% by mass.

When the block copolymer of the present embodiment contains the polymer block (B), the content of the polymer block (B) can be measured by an NMR method.

From the viewpoint of reactivity and compatibility between the polymer blocks (B) composed of conjugated diene monomer units and/or the block copolymer and the component (II), component (III) and component (IV) described later, the content of the polymer block (B) in the block copolymer of the present embodiment is preferably 5 to 45% by mass, more preferably 10 to 40% by mass, and even more preferably 15 to 35% by mass.

The polymer block (C) is composed of a vinyl aromatic monomer unit and a conjugated diene monomer unit, and does not contain any monomer other than the vinyl aromatic monomer unit and the conjugated diene monomer unit.

The polymer block (C) has a structure in which a vinyl aromatic monomer unit and a conjugated diene monomer unit are intentionally used as structural units, and from this point of view, it can be distinguished from the above-mentioned polymer block (A) and polymer block (B).

The vinyl aromatic compound and the conjugated diene compound used for forming the vinyl aromatic monomer unit and the conjugated diene monomer unit contained in the polymer block (C) may be any compounds that can be used for the polymer block (A) and the polymer block (B).

There is no particular limitation on the distribution state of the vinyl aromatic monomer units in the polymer block (C). The vinyl aromatic monomer units may be uniformly distributed in the random copolymer block or may be distributed in a tapered manner. In addition, there may be a plurality of portions where the vinyl aromatic monomer units are uniformly distributed and/or portions where the vinyl aromatic monomer units are tapered, respectively, or there may be a plurality of segments with different contents of the vinyl aromatic monomer units.

When the block copolymer of the present embodiment contains the polymer block (C), the content of the polymer block (C) can be measured by an NMR method.

From the perspective of reactivity and compatibility between the conjugated diene monomer units in the polymer block (C) and/or the block copolymer and the component (II), component (III) and component (IV) described later, the content of the polymer block (C) in the block copolymer of the present embodiment is preferably 20 to 90% by mass, more preferably 35 to 85% by mass, further preferably 30 to 80% by mass, further more preferably 35 to 75% by mass, and further preferably 40 to 70% by mass.

The block copolymer of the present embodiment may have a copolymer block (D) obtained by copolymerizing a compound other than the above-mentioned polymer blocks (A) to (C) with a conjugated diene compound and/or a vinyl aromatic compound within a range that does not impair the desired dielectric properties of the cured product, that is, within a range that does not impair the low dielectric loss tangent and low dielectric constant.

For example, when the block copolymer of the present embodiment including the copolymer block (D) is produced by anionic polymerization, methyl methacrylate (MMA) can be copolymerized with a vinyl aromatic compound or a conjugated diene compound. However, if MMA is contained, the dielectric properties of the block copolymer of the present embodiment tend to decrease, that is, the dielectric constant and/or dielectric loss tangent tend to increase.

The structure of the block copolymer of the present embodiment is not particularly limited, and examples thereof include a block copolymer having a structure represented by the following formula.

(ab) _n , b-(ab) _n , a-(ba) _n , (ab) _m -X, (ba) _m -X, [(ab) _n ] _m -X, [(ba) _n ] _m -X, [b-(ab) _n ] _m -X, [a-(ba) _n ] _m -X, [(ab) _n -a] _m -X, [(ba) _n -b] _m -X ,

(ac) _n , c-(ac) _n , a-(ca) _n , (ac) _m -X, (ca) _m -X, [(ac) _n ] _m -X, [(ca) _n ] _m -X, [c-(ac) _n ] _m -X, [a-(ca) _n ] _m -X, [(ac) _n -a] _m -X, [(ca) _n -c] _m -X ,

c-(ba) _n , c-(ab) _n ,

c-(aba) _n , c-(bab) _n ,

ac-(ba) _n , ac-(ab) _n ,

ac-(ba) _n -b、[(abc) _n ] _m -X、

[a-(bc) _n ] _m -X, [(ab) _n -c] _m -X,

[(aba) _n -c] _m -X,

[(bab) _n -c] _m -X, [(cba) _n ] _m -X,

[c-(ba) _n ] _m -X, [c-(aba) _n ] _m -X, [c-(bab) _n ] _m -X

a-(bc) _n , a-(cb) _n ,

a-(cbc) _n , a-(bcb) _n ,

ca-(bc) _n , ca-(cb) _n ,

ca-(bc) _n -b, [(cba) _n ] _m -X,

[c-(ba) _n ] _m -X, [(cb) _n -a] _m -X,

[(cbc) _n -a] _m -X,

[(bcb) _n -a] _m -X, [(abc) _n ] _m -X,

[a-(bc) _n ] _m -X, [a-(cbc) _n ] _m -X, [a-(bcb) _n ] _m -X

b-(ac) _n , b-(ca) _n ,

b-(cac) _n , b-(aca) _n ,

cb-(ac) _n 、cb-(ca) _n 、

cb-(ac) _n -a, [(cab) _n ] _m -X,

[c-(ab) _n ] _m -X, [(ca) _n -b] _m -X,

[(cac) _n -b] _m -X,

[(bac) _n ] _m -X,

[b-(ac) _n ] _m -X, [b-(cac) _n ] _m -X, [b-(aca) _n ] _m -X

It should be noted that, in the above general formulas, a represents the above polymer block (A), b represents the above polymer block (B), and c represents the above polymer block (C).

n is an integer of 1 or more, preferably an integer of 1-5.

m is an integer of 2 or more, and preferably an integer of 2-11.

X represents the residue of a coupling agent or the residue of a multifunctional initiator.

The polymer block (A) is a polymer block mainly composed of vinyl aromatic monomer units and is therefore amorphous. In the resin composition and cured product of the present embodiment described below, the entanglement strength and heat resistance are improved by containing the polymer block (A).

The polymer block (B) is a polymer block mainly composed of conjugated diene monomer units and therefore has free radical reactivity.

In the resin composition and cured product of the present embodiment described below, the heat resistance tends to be improved by the reaction between the polymer blocks and/or the block copolymers of the present embodiment.

When the block copolymer of the present embodiment forms a resin composition with the component (III) and/or component (IV) described later which do not have free radical reactivity, the conjugated diene monomer unit has less steric hindrance than the vinyl aromatic monomer unit and is therefore compatible with the component (III) and/or component (IV), and the resin composition and cured product of the present embodiment tend to have excellent strength and heat resistance.

In addition, by improving the reactivity and compatibility of the above-mentioned polymer blocks and/or block copolymers, in the resin composition and cured product of the present embodiment described later, the reduction in polymer mobility and polarization caused by the external electric field can be suppressed, and the resin composition and cured product have a low dielectric loss tangent and a low dielectric constant.

The polymer block (C) is a polymer block comprising a vinyl aromatic monomer unit and a conjugated diene monomer unit, and therefore, it is expected that the strength improvement effect due to the mutual entanglement with the polymer block (A) mainly comprising the vinyl aromatic monomer unit and the free radical reactivity and compatibility improvement effect with other components other than the polymer blocks (A) and (B) can be achieved. On the other hand, from the aspect of the strength improvement due to the mutual entanglement, there is a tendency that the strength improvement effect due to the mutual entanglement between the polymer blocks (A) is inferior.

As described later, the resin composition of the present embodiment includes the block copolymer of the present embodiment (component (I)), component (II): a radical initiator, component (III): a polar resin, and component (IV): a curing agent.

Component (II), component (III) and component (IV) have a polar group.

From the perspective of solubility parameters, vinyl aromatic compounds have better compatibility with components (II), (III) and (IV) than conjugated diene compounds. However, the block copolymer of this embodiment has reduced steric hindrance during copolymerization of conjugated diene compounds. If it has a polymer block (C), its compatibility with components (III) and (IV) is improved.

In this embodiment, in order to obtain a resin composition and a cured product having high strength, low dielectric loss tangent and low dielectric constant, from the aspect of the mutual entanglement of polymers composed of vinyl aromatic compounds, the block copolymer of this embodiment has a polymer block (A) mainly composed of vinyl aromatic monomer units, and from the aspect of the above-mentioned reactivity and/or compatibility, has a polymer block (B) and/or a polymer block (C).

In addition, when a resin containing an aromatic ring such as a polyphenylene ether resin is used as component (III) of the resin composition of the present embodiment: a polar resin, the block copolymer of the present embodiment has a tendency to have improved compatibility and further improved strength of the cured product by containing a polymer block (A) mainly composed of a vinyl aromatic monomer unit.

The block copolymer contained in the resin composition of the present embodiment satisfies the conditions (i) and (ii).

<Condition (i)>

The weight average molecular weight of the block copolymer of the present embodiment is 35,000 or less.

The weight average molecular weight is determined by measuring the molecular weight of the peak of the chromatogram obtained by gel permeation chromatography (GPC) based on a calibration curve obtained by measuring commercially available standard polystyrene (prepared using the peak molecular weight of standard polystyrene). Specifically, the weight average molecular weight can be determined by the method described in the examples described below.

The molecular weight distribution is the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn).

The molecular weight distribution of a single peak of the block copolymer of the present embodiment measured by GPC is preferably 5.0 or less, more preferably 4.0 or less, further preferably 3.0 or less, and still more preferably 2.5 or less.

By making the weight average molecular weight of the block copolymer of this embodiment less than 35,000, the compatibility with the component (III): polar resin and component (IV): curing agent constituting the resin composition of this embodiment described later is improved, the strength of the resin composition and the cured product can be improved, and the dielectric loss tangent and dielectric constant can be reduced.

In addition, when a prepreg is prepared using the resin composition of the present embodiment, when a substrate such as glass cloth described later is impregnated with the varnish described later, by making the weight average molecular weight of the block copolymer of the present embodiment be 35,000 or less, the permeability to the substrate is improved, and a uniform prepreg tends to be prepared.

From the above aspects, the weight average molecular weight of the block copolymer of the present embodiment is preferably 30,000 or less, more preferably 25,000 or less, further preferably 20,000 or less, further more preferably 15,000 or less, and further preferably 10,000 or less. The lower limit is not particularly limited, but is preferably 500 or more from the perspective of suppressing the stickiness of the block copolymer of the present embodiment and having good handleability.

The weight average molecular weight and molecular weight distribution of the block copolymer of the present embodiment can be controlled within the above numerical range by adjusting polymerization conditions such as the amount of monomer added, the timing of addition, the polymerization temperature, and the polymerization time.

<Condition (ii)>

The content of the vinyl aromatic monomer unit in the block copolymer of the present embodiment is 55% by mass or more and 95% by mass or less.

By being within the above numerical range, there is a tendency that the compatibility with the component (II), the component (III), and the component (IV) described later is excellent from the viewpoint of the solubility parameter.

By making the content of the vinyl aromatic monomer unit in the block copolymer of the present embodiment 55% by mass or more, the compatibility with the component (II), component (III) and component (IV) described later is improved, and there is a tendency that the strength of the resin composition and the cured product of the present embodiment can be improved, and the dielectric loss tangent and the dielectric constant can be reduced.

In addition, from the perspective of solubility parameter, the content of the vinyl aromatic monomer unit in the block copolymer of the present embodiment is preferably 57% by mass or more, more preferably 60% by mass or more, even more preferably 63% by mass or more, further preferably 65% by mass or more, and particularly preferably 67% by mass or more.

By making the content of the vinyl aromatic monomer unit 95% by mass or less, the reactivity with the components (II), (III) and (IV) described later and the reactivity between the block copolymers of the present embodiment can be ensured.

According to the present inventors' view, the dielectric properties of the block copolymer are correlated to a certain extent with the state of the cured product. By curing the block copolymer of the present embodiment in a state of reaction or compatibility with other components, the molecular chain becomes difficult to move, and there is a tendency to improve the dielectric properties of the cured product, i.e., to lower the dielectric constant. Therefore, from the aspect of improving the dielectric properties of the cured product, it is preferred to control them with an eye not only to the dielectric constant or dielectric properties of the block copolymer of the present embodiment, but also to the reactivity and compatibility with other components.

If the content of the vinyl aromatic monomer unit in the block copolymer of the present embodiment is 55% by mass or more, the compatibility with the component (II), component (III) and component (IV) described later becomes good, the mutual entanglement caused by the coagulation of the polymer block (A) mainly composed of the vinyl aromatic monomer unit increases, high strength can be achieved, and low dielectric loss tangent and low dielectric constant can be achieved.

The content of the vinyl aromatic monomer unit in the block copolymer (I) can be controlled within the above numerical range by adjusting polymerization conditions such as the amount of monomer added, the timing of addition, and the polymerization temperature. Specifically, it can be calculated by the method described in the examples below.

The block copolymer of the present embodiment preferably further satisfies the condition (iii).

<Condition (iii)>

The polymer block (B) and/or the polymer block (C) comprises a unit (a) derived from a 1,2-bond and/or a 3,4-bond (hereinafter sometimes referred to as unit (a)) and a unit (b) derived from a 1,4-bond (hereinafter sometimes referred to as unit (b)), and when the total content of the conjugated diene monomer unit in the polymer block (B) and/or the polymer block (C) is 100%, the content of the unit (a) derived from the 1,2-bond and/or 3,4-bond is 80% or less.

It should be noted that in the calculation of the content of the unit (a) in the block copolymer, when the block copolymer contains both the polymer block (B) and the polymer block (C), the total content of the conjugated diene monomer units in the polymer block (B) and the polymer block (C) is set to 100%, when the block copolymer contains only the polymer block (B), the content of the polymer block (B) is set to 100%, and when the block copolymer contains only the polymer block (C), the content of the conjugated diene monomer units in the polymer block (C) is set to 100%.

When both 1,2-bond and 3,4-bond are contained, the total content of 1,2-bond and 3,4-bond is the content of unit (a) (vinyl bond amount).

The unit (a) has higher radical reactivity than the unit (b). When the resin composition of the present embodiment described later or the resin varnish containing the block copolymer of the present embodiment is stored before curing, by making the content of the unit (a) 80% or less, the resin composition and the resin varnish tend to show sufficient storage stability.

From the viewpoint of the reactivity of the conjugated diene monomer units in the block copolymer of the present embodiment and the reactivity of the block copolymer with other components, the lower limit of the content of the unit (a) is preferably 20% or more, more preferably 30% or more, further preferably 40% or more, and even more preferably 50% or more.

The content of the above-mentioned unit (a) can be controlled within the above-mentioned numerical range by using a regulator such as a polar compound during polymerization, and can be calculated by the method described in the examples described later.

Examples of the regulator include tertiary amine compounds and ether compounds, and preferably tertiary amine compounds are used.

The tertiary amine compound is a compound of the general formula R1R2R3N (wherein R1, R2, and R3 are a hydrocarbon group having 1 to 20 carbon atoms, or a hydrocarbon group having a tertiary amino group).

Examples of tertiary amine compounds include, but are not limited to, trimethylamine, triethylamine, tributylamine, N,N-dimethylaniline, N-ethylpiperidine, N-methylpyrrolidine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, 1,2-dipiperidinylethane, trimethylaminoethylpiperazine, N,N,N',N",N"-pentamethylethylenetriamine, and N,N'-dioctyl-p-phenylenediamine.

The block copolymer of the present embodiment may be a hydrogenated block copolymer in which the aliphatic double bonds of the conjugated diene compound are hydrogenated within a range that does not impair the curing reaction.

The method for hydrogenating the block copolymer is not particularly limited, and a conventionally known method can be applied.

In the above hydrogenation reaction, a hydrogenation catalyst may be used.

As hydrogenation catalysts, for example: (1) supported heterogeneous hydrogenation catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silicon oxide, aluminum oxide, diatomaceous earth, and the like; (2) so-called Ziegler-type hydrogenation catalysts using organic acid salts of Ni, Co, Fe, Cr, and the like or transition metal salts such as acetylacetonate and reducing agents such as organic aluminum; (3) homogeneous hydrogenation catalysts such as so-called organic metal complexes such as organic metal compounds of Ti, Ru, Rh, and Zr, and the like.

As the hydrogenation catalyst, specifically, those described in JP-B-42-8704, JP-B-43-6636, JP-B-63-4841, JP-B-1-37970, JP-B-1-53851, and JP-B-2-9041 can be used.

Preferred hydrogenation catalysts include cyclopentadienyl titanium compounds and/or reducing organic metal compounds.

As the cyclopentadienyl titanium compound, the compounds described in Japanese Patent Publication No. 8-109219 can be used. As the cyclopentadienyl titanium compound, for example, compounds having at least one ligand having a (substituted) cyclopentadienyl skeleton, an indenyl skeleton or a fluorenyl skeleton, such as biscyclopentadienyl titanium dichloride and mono(pentamethylcyclopentadienyl)titanium trichloride, can be cited. The cyclopentadienyl titanium compound can contain one or two of the above skeletons alone.

Examples of the reducing organometallic compound include organolithium and other organoalkali metal compounds, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds, etc. These may be used alone or in combination of two or more.

By timely adjusting the reaction temperature, reaction time, hydrogen supply, catalyst amount, etc. in the hydrogenation method, the hydrogenation rate of the block copolymer can be controlled. Regarding the temperature during the hydrogenation reaction, it is preferably carried out at 55 to 200 ° C, more preferably 60 to 170 ° C, and more preferably 65 ° C to 160 ° C. In addition, the pressure of hydrogen used in the hydrogenation reaction is preferably 0.1 to 15 MPa, more preferably 0.2 to 10 MPa, and more preferably 0.3 to 5 MPa. In addition, the hydrogenation reaction time is usually 3 minutes to 10 hours, preferably 10 minutes to 5 hours.

The hydrogenation reaction may be carried out in a batch process, a continuous process, or a combination thereof.

When the curing reaction for obtaining the cured product of the present embodiment described later is a free radical reaction, the hydrogenation rate of the block copolymer of the present embodiment is preferably 5 to 95%, more preferably 10 to 90%, and further preferably 13 to 87%, from the perspective of the balance between the curing reactivity and thermal stability. When the curing reaction is other than a free radical reaction, the hydrogenation rate can be arbitrarily selected between 0 and 100% from the perspective of the compatibility of the block copolymer of the present embodiment with other components.

[Method for producing block copolymer]

The block copolymer of the present embodiment can be produced, for example, by living anionic polymerization in a hydrocarbon solvent using a polymerization initiator such as an organic alkali metal compound.

Examples of the hydrocarbon solvent 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; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; and the like.

Examples of the polymerization initiator include organic alkali metal compounds such as aliphatic hydrocarbon alkali metal compounds, aromatic hydrocarbon alkali metal compounds, and organic amino alkali metal compounds, which are generally known to have anionic polymerization activity with conjugated diene compounds and vinyl aromatic compounds.

Examples of the alkali metal include lithium, sodium, and potassium.

Examples of the organic alkali metal compound include aliphatic and aromatic hydrocarbon lithium compounds having 1 to 20 carbon atoms, including compounds containing one lithium in one molecule, and dilithium compounds, trilithium compounds, and tetralithium compounds containing a plurality of lithiums in one molecule.

Specific examples of the organic alkali metal compound include n-propyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, n-pentyl lithium, n-hexyl lithium, benzyl lithium, phenyl lithium, tolyl lithium, the reaction product of diisopropenylbenzene and sec-butyl lithium, and the reaction product of divinylbenzene, sec-butyl lithium and a small amount of 1,3-butadiene, etc. In addition, 1-(tert-butoxy)propyl lithium disclosed in U.S. Patent No. 5,708,092 and a lithium compound in which one to several molecules of isoprene monomer are inserted to improve its solubility, alkyl lithium containing silyl group such as 1-(tert-butyldimethylsilyloxy)hexyl lithium disclosed in British Patent No. 2,241,239, alkyl lithium containing amino group disclosed in U.S. Patent No. 5,527,753, lithium amides such as lithium diisopropylamine and lithium hexamethyldisilazide can also be used.

As a method for polymerizing a vinyl aromatic compound and a conjugated diene polymer using an organic alkali metal compound as a polymerization initiator, a conventionally known method can be applied.

The polymerization method may be, for example, batch polymerization, continuous polymerization, or a combination thereof. In order to obtain uniform polymer blocks, batch polymerization is preferred.

The polymerization temperature is preferably 0°C to 180°C, more preferably 30°C to 150°C. The polymerization time varies depending on the conditions, but is generally within 48 hours, preferably 0.1 to 10 hours. In addition, as the atmosphere of the polymerization system, an inert gas atmosphere such as nitrogen is preferred. Regarding the polymerization pressure, it is not particularly limited as long as it is set within a pressure range that can maintain the monomer and the solvent in a liquid phase within the above-mentioned temperature range. In addition, care should be taken not to mix impurities such as water, oxygen, and carbon dioxide into the polymerization system that deactivate the catalyst and the active polymer.

Furthermore, at the end of the polymerization step, a coupling reaction may be carried out by adding a required amount of a bifunctional or higher-functional coupling agent. The coupling rate is preferably 40% or less, more preferably 30% or less, further preferably 20% or less, and further preferably no coupling agent is contained.

As the bifunctional coupling agent, a conventionally known coupling agent can be used without particular limitation.

Examples of the bifunctional coupling agent include, but are not limited to, alkoxysilane compounds such as trimethoxysilane, triethoxysilane, tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dichlorodimethoxysilane, dichlorodiethoxysilane, trichloromethoxysilane, and trichloroethoxysilane; dihalides such as dichloroethane, dibromoethane, dimethyldichlorosilane, and dimethyldibromosilane; and acid esters such as methyl benzoate, ethyl benzoate, phenyl benzoate, and phthalates.

As the trifunctional or higher polyfunctional coupling agent, any conventionally known coupling agent can be used without particular limitation.

As the polyfunctional coupling agent having three or more functions, there can be mentioned, but not limited to, for example, trivalent or more polyols; polyvalent epoxy compounds such as epoxidized soybean oil, diglycidyl bisphenol A, 1,3-bis(N-N'-diglycidylaminomethyl)cyclohexane; silicon halide compounds represented by the general formula R ₄ -nSiX _n (where R represents a hydrocarbon group having 1 to 20 carbon atoms, X represents a halogen, and n represents an integer of 3 to 4), such as methyltrichlorosilane, tert-butyltrichlorosilane, silicon tetrachloride, and bromides thereof; tin halide compounds represented by the general formula R ₄ -nSnX _n (where R represents a hydrocarbon group having 1 to 20 carbon atoms, X represents a halogen, and n represents an integer of 3 to 4), such as polyvalent halides such as methyltin trichloride, tert-butyltin trichloride, and tin tetrachloride. In addition, dimethyl carbonate, diethyl carbonate, etc. can also be used.

The block copolymer solution of the present embodiment obtained as described above can be separated from the block copolymer by removing catalyst residues as necessary.

The polymerization initiator when manufacturing the block copolymer by anionic living polymerization, the compound containing metal atoms in the hydrogenation catalyst in the above-mentioned hydrogenation reaction reacts with moisture in the air in the desolvation process, etc. to generate specific metal compounds, which tend to remain in the block copolymer. If these compounds are contained in the cured product, the dielectric constant and dielectric loss tangent tend to increase, and further, there is a tendency to easily generate ion migration in the use of electronic materials.

As residual metal compounds, there can be mentioned compounds of metals contained in polymerization initiators and hydrogenation catalysts, for example, oxides containing atoms of titanium oxide, amorphous titanium oxide, orthotitanic acid or metatitanic acid, titanium hydroxide, nickel hydroxide, nickel monoxide, lithium oxide, lithium hydroxide, cobalt oxide, cobalt hydroxide, and composite oxides of atoms of the same and heterogeneous metals such as lithium titanate, barium titanate, strontium titanate, nickel titanate, and nickel-iron oxide.

In the cured product of the resin composition of the present embodiment, from the perspective of seeking low dielectric constant, low dielectric loss tangent, and being difficult to produce ion migration, the residual amount of the metal compound in the block copolymer is preferably less than 150ppm, more preferably less than 130ppm, further preferably less than 100ppm, and further more preferably less than 90ppm in terms of residual metal amount. As specific residual metals, Ti, Ni, Li, Co, etc. can usually be cited.

As a method for reducing the amount of residual metal in the block copolymer of the present embodiment, an existing known method can be applied without particular limitation. For example, a method of neutralizing the hydrogenation catalyst residue by adding water and carbon dioxide after the hydrogenation reaction of the block copolymer; a method of neutralizing the hydrogenation catalyst residue by adding an acid in addition to water and carbon dioxide. Specifically, the method described in Japanese Patent Application No. 2014-557427 can be applied. Even if these metal removal methods are used, since water containing hydroxides of metal compounds will be mixed in the desolventizing process of the block copolymer, the residual metal usually contains about 1 to 15 ppm. Thus, relative to the amount of metal added to the block copolymer, it is preferred to remove more than 20%, more preferably more than 30%, further preferably more than 40%, and further more preferably more than 50%, and further preferably more than 60%.

In addition, by reducing the amount of added polymerization initiator and hydrogenation catalyst itself, the amount of residual metal in the block copolymer can also be reduced, but if the amount of polymerization initiator is reduced, the molecular weight of the block copolymer is improved, and if it falls outside the above-mentioned preferred molecular weight range, there is a tendency for the strength of the cured product to decrease. In addition, when performing the hydrogenation reaction, if the amount of hydrogenation catalyst is reduced, the hydrogenation reaction time will be prolonged and the hydrogenation reaction temperature will be high, which has a tendency to significantly reduce productivity.

As a method for separating the solvent when taking out the block copolymer from a block copolymer solution, for example, there can be cited: a method of adding a polar solvent such as acetone or alcohol, which is a poor solvent for the block copolymer, to the reaction solution after hydrogenation to precipitate the block copolymer and recover it; a method of adding the reaction solution to hot water under stirring and recovering it by removing the solvent by steam stripping; a method of directly heating the block copolymer solution to distill off the solvent; and the like.

It should be noted that stabilizers such as various phenol stabilizers, phosphorus stabilizers, sulfur stabilizers, and amine stabilizers may be added to the hydrogenated product of the block copolymer.

The block copolymer of the present embodiment may have a “polar group” within a range that does not impair the dielectric properties.

Examples of the “polar group” include, but are not limited to, a functional group selected from the group consisting of a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acyl halide group, an acid anhydride group, a carboxylic acid group, a thiocarboxylic acid group, an aldehyde group, a thialdehyde group, a carboxylate group, an amide group, a sulfonic acid group, a sulfonate group, a phosphoric acid group, a phosphate group, an amino group, an imino group, a nitrile group, a pyridyl group, a quinoline group, an epoxy group, a thioepoxy group, a thioether group, an isocyanate group, an isothiocyanate group, a silicon halide group, a silanol group, an alkoxysilyl group, a tin halide group, a boric acid group, a boron-containing group, a borate group, an alkoxytin group, and a phenyltin group, and an atomic group containing at least one of these functional groups.

The above-mentioned "polar group" can be formed using a modifier.

Examples of the modifier include, but are not limited to, tetraglycidyl-m-xylylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, ε-caprolactone, δ-valerolactone, 4-methoxybenzophenone, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyldimethylphenoxysilane, bis(γ-glycidoxypropyl)methylpropoxysilane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, N-methylpyrrolidone, maleic acid, maleic anhydride, maleic anhydride imide, fumaric acid, itaconic acid, acrylic acid, methacrylic acid, glycidyl methacrylate, and crotonic acid.

As a method for forming a "polar group", a known method can be applied without particular limitation.

Examples include: a melt kneading method; a method of dissolving or dispersing each component in a solvent and reacting the components; etc. In addition, examples include: a method of performing polymerization by anionic living polymerization using a polymerization initiator having a functional group or an unsaturated monomer having a functional group; a method of performing modification by an addition reaction of a modifier having a functional group formed or contained at an active end; a method of reacting an organic alkali metal compound such as an organic lithium compound with a block copolymer (metallization reaction) and performing an addition reaction of a modifier having a functional group and a block polymer to which an organic alkali metal is added.

[Resin composition]

The resin composition in the present embodiment contains the block copolymer (component (I)) in the present embodiment and at least one component selected from the group consisting of the following components (II) to (IV).

Component (II): Free radical initiator

Component (III): Polar resin (excluding component (I))

Component (IV): Curing agent (excluding component (II))

From the viewpoint of lowering the dielectric constant, lowering the dielectric loss tangent, and improving flexibility of the resin composition of the present embodiment and its cured product, the resin composition of the present embodiment preferably contains component (I): the above block copolymer and component (II): a radical initiator.

(Component (II): free radical initiator)

As the radical initiator, a conventionally known one can be used, and examples thereof include a thermal radical initiator.

Examples of the thermal free radical initiator include, but are not limited to, hydroperoxides such as diisopropylbenzene hydroperoxide (Percumyl P), cumene hydroperoxide (Percumyl H), and tert-butyl hydroperoxide (Perbutyl H); α,α-bis(tert-butylperoxym-isopropyl)benzene (Perbutyl P), dicumyl peroxide (Percumyl D), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (PERHEXA25B), tert-butyl cumyl peroxide (Perbutyl C), di-tert-butyl peroxide (Perbutyl D), 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne (Perhexyne 25B), tert-butyl peroxide (2-ethylhexanoate) (Perbutyl O) and other dialkyl peroxides; ketone peroxides; peroxy ketals such as 4,4-di(tert-butylperoxy)valerate (PERHEXAV); diacyl peroxides; peroxydicarbonates; organic peroxides such as peroxyesters; azo compounds such as 2,2-azobisisobutyronitrile, 1,1'-(cyclohexane-1-1-carbonitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile); etc.

These may be used alone or in combination of two or more.

(Component (III): polar resin)

From the aspect of imparting properties such as adhesion to a specified substrate, the resin composition of the present embodiment may contain component (III): polar resin (excluding component (I)) within a range that does not impair dielectric properties such as low dielectric constant and low dielectric loss tangent of the cured product. By containing a polar resin, the resin composition of the present embodiment tends to have excellent adhesion to a specified substrate.

When the component (III) is a polar resin having radical reactivity, the amount of the radical initiator of the component (II) may be appropriately adjusted according to the reactivity, or the component (II) may not be added.

Examples of the polar resin having free radical reactivity as component (III) include homopolymers of compounds containing at least one vinyl group and/or halogen element in the polymer and/or copolymers with any compound. From the viewpoint of reactivity, those having a vinyl group are preferred.

The polymer having a vinyl group may be a polymer composed of repeating units having a vinyl group, may be a polymer with a compound having a vinyl group and a polar group, or may be a polymer having a vinyl group obtained by reacting polar groups of a compound having a polar group.

Examples of compounds having a vinyl group and a polar group include carboxyl group-containing vinyl monomers such as (meth)acrylic acid (in this specification, "(meth)acrylic acid" means methacrylic acid or acrylic acid), maleic acid, monoalkyl maleate, and fumaric acid; sulfone group-containing vinyl monomers such as vinyl sulfonic acid, (meth)allyl sulfonic acid, methyl vinyl sulfonic acid, and styrene sulfonic acid; hydroxyl group-containing vinyl monomers such as hydroxystyrene, N-hydroxymethyl (meth)acrylamide, hydroxyethyl (meth)acrylate, and hydroxypropyl (meth)acrylate; phosphoric acid group-containing vinyl monomers such as 2-hydroxyethyl (meth)acryloyl phosphate, phenyl-2-acryloyloxyethyl phosphate, and 2-acryloyloxyethylphosphonic acid; hydroxystyrene, N-hydroxymethyl (meth)acrylamide, hydroxyethyl (meth)acrylate, and hydroxypropyl (meth)acrylate; - Hydroxyl group-containing vinyl monomers such as hydroxymethyl (meth)acrylamide, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, 1-butene-3-ol, etc.; amino group-containing vinyl monomers such as aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, etc.; amide group-containing vinyl monomers such as (meth)acrylamide, N-methyl (meth)acrylamide, N-butylacrylamide, etc.; nitrile group-containing vinyl monomers such as (meth)acrylonitrile, cyanostyrene, cyanoacrylate, etc.; epoxy group-containing vinyl monomers such as glycidyl methacrylate, tetrahydrofurfuryl (meth)acrylate, p-vinylphenylphenyl oxide, etc.

Examples of the compound containing a halogen element include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

(Component (IV): curing agent)

When the radical reactivity of the component (III) is low, the resin composition of the present embodiment preferably contains a component (IV): a curing agent (excluding the component (II)) from the viewpoint of reactivity.

The component (IV): a curing agent generally has a function of reacting with the component (III): a polar resin to cure the resin composition.

The "reaction" of component (III) and component (IV) means that the polar groups of the respective components have covalent bonding properties. When the polar groups react with each other, for example, if the OH of the carboxyl group is detached, the original polar group changes or disappears, and a covalent bond is formed, which is included in the definition that the polar groups show "reactivity" with each other.

From the viewpoint of curing function, the curing agent as component (IV) preferably has at least two polar groups capable of reacting with the functional groups of the polar resin as component (III) in one molecular chain.

The component (IV) may be used alone or in combination of two or more.

The type of polar groups possessed by component (III) and component (IV) is not particularly limited, and examples thereof include:

Epoxy and carboxyl, carbonyl, ester, imidazole, hydroxyl, amino, thiol, benzoxazine, carbodiimide, phenolic hydroxyl;

Amino group and carboxyl group, carbonyl group, hydroxyl group, anhydride group, sulfonic acid group, aldehyde group;

Isocyanate group and hydroxyl group, carboxylic acid group, phenolic hydroxyl group;

Anhydride group and hydroxyl group;

Silanol group and hydroxyl group, carboxylic acid group;

Halogen and carboxylic acid, carboxylate, amino, phenol, and mercapto groups;

Alkoxy and hydroxyl, alkoxide, and amino groups;

Maleimide group and cyanate group, etc.

Whether the bonding of these polar groups is component (III) or component (IV) can be arbitrarily selected.

Furthermore, even when the polar group of component (III) and the polar group of component (IV) do not react directly, the case where they can react by adding a curing accelerator such as a catalyst is also included in the definition of showing "reactivity".

For example, when component (III) is a polar resin having an epoxy group and component (IV) is a curing agent having an acid anhydride group, the reactivity between the epoxy group and the acid anhydride group is generally very low, but by adding a compound having an amino group as a curing accelerator, the epoxy group of component (III) reacts with the amino group, and a part or all of the epoxy group of component (III) becomes a hydroxyl group. The hydroxyl group reacts with the acid anhydride group of component (IV): the curing agent, and the resin composition is cured.

From the perspective of reactivity, the ratio of component (III): polar resin to component (IV): curing agent is preferably component (III): component (IV) = 1:0.01 to 1:20, more preferably 1:0.05 to 1:15, and even more preferably 1:0.1 to 1:10, in terms of the molar ratio of the polar groups.

Component (IV): Curing agent Examples of the curing agent having an ester group 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.

As curing agents having a hydroxyl group, for example, 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 manufactured by DIC Corporation, etc.

Examples of the curing agent having a benzoxazine group include ODA-BOZ manufactured by JFE Chemical Co., Ltd., HFB2006M manufactured by Showa Highpolymer Co., Ltd., and P-d and F-a manufactured by Shikoku Chemical Industry Co., Ltd.

Examples of curing agents having an isocyanate group include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4′-methylenebis(2,6-dimethylphenylcyanate), 4,4′-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)sulfide, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; prepolymers in which these cyanate resins are partially triazinized; and the like. Examples of commercially available products include PT30, PT60, ULL-950S, BA230, and BA230S75 manufactured by Lonza Japan.

Examples of the curing agent having a carbodiimide group include V-03 and V-07 manufactured by Nisshinbo Chemical Co., Ltd.

Examples of the curing agent having an amino group include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, metaphenylenediamine, metaphenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino- 4-hydroxyphenyl)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)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. Commercially available products include KAYABOND C-200S, KAYABOND C-100, KAYAHARD A-A, KAYAHARD A-B, KAYAHARD A-S manufactured by Nippon Kayaku Co., Ltd., and Epicure W manufactured by Mitsubishi Chemical Corporation.

In addition, from the viewpoint of reactivity, the amino group is preferably a primary amine and/or a secondary amine, and more preferably a primary amine.

Examples of the curing agent having an acid anhydride group include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyrophthalic anhydride, and the like. Tetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxydiphthalic anhydride, 3,3'-4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthol[1,2-C]furan-1,3-dione, ethylene glycol bis(trimellitic anhydride), styrene-maleic acid resin obtained by copolymerization of styrene and maleic acid, and the like polymer type acid anhydrides, etc.

Furthermore, the compound having at least two structures having free radical reactivity also has the function of reacting with the component (III) to cure the resin composition. The compound can also be used as a curing agent for the component (IV).

Examples of the compound having at least two structures having free radical reactivity include allyl monomers such as triallyl isocyanurate (TAIC manufactured by Mitsubishi Chemical Corporation), tris(2-hydroxyethyl)isocyanurate, diallyl fumarate, diallyl adipate, triallyl citrate, and diallyl hexahydrophthalate.

When the resin composition of the present embodiment contains component (III), the polar resin as component (III) is preferably at least one selected from the group consisting of epoxy resins, polyimide resins, polyphenylene ether resins, liquid crystal polyester resins, and fluorine resins from the aspect of adhesiveness. More preferably, it is at least one selected from the group consisting of epoxy resins, polyimide resins, and polyphenylene ether resins.

As the polyimide resin of component (III), as long as the repeating unit has an imide bond and belongs to the category called polyimide resin. For example, the structure of a general polyimide obtained by polycondensing tetracarboxylic acid or its dianhydride with diamine (forming an imide bond) can be cited. From the aspect of curability, it is preferred to have an unsaturated group at the end of the above-mentioned polyimide structure. As the polyimide resin having an unsaturated group at the end, for example, maleimide type polyimide resin, nadic imide type polyimide resin, allyl nadic imide type polyimide resin, etc. can be cited.

Examples of the tetracarboxylic acid or its dianhydride include, but are not limited to, aromatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, etc. These may be used alone or in combination of two or more.

The diamine is not particularly limited, and examples thereof include aromatic diamines, alicyclic diamines, aliphatic diamines, etc., which are generally used in the synthesis of polyimide. These may be used alone or in combination of two or more.

In addition, from the perspective of low dielectric constant and low dielectric loss tangent, at least one of the above-mentioned tetracarboxylic acids or their dianhydrides or diamines may have one or more functional groups selected from the group consisting of fluorine, trifluoromethyl, hydroxyl, sulfone, carbonyl, heterocycle, long-chain alkyl, allyl, etc.

In addition, as the polyimide resin of component (III), commercially available polyimide resins may be used, for example, Neoprim (registered trademark) C-3650 (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), Neoprim C-3G30 (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), Neoprim C-3450 (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), Neoprim P500 (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name), BT (bismaleimide triazine) resin (manufactured by Mitsubishi Gas Chemical Co., Ltd.), JL-20 (manufactured by Shin Nippon Rika, trade name) (the varnish of these polyimide resins may contain silicon oxide), RIKACOAT SN20 and RIKACOAT SN20 manufactured by Shin Nippon Rika, Ltd. PN20, Pyre-ML manufactured by I.S.T., UPIA-AT, UPIA-ST, UPIA-NF, UPIA-LB manufactured by Ube Industries, 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 K.K., BMI-2300 manufactured by Yamato Kasei Kogyo Co., Ltd., and MIR-3000 manufactured by Shin Nippon Kayaku Co., Ltd.

The polyphenylene ether-based resin as component (III) may be any resin that falls within the category of polyphenylene ether resins and contains a phenylene ether unit as a repeating structural unit and may contain other structural units besides the phenylene ether unit.

As a homopolymer having a phenylene ether unit, there is no particular limitation on whether the phenylene group in the phenylene unit has a substituent. Examples of the substituent include: ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl and other acryloyl groups; cyclohexyl and other cyclic alkyl groups; vinyl, allyl, isopropenyl, 1-butenyl, 1-pentenyl, p-vinylphenyl, p-isopropenylphenyl, m-vinylphenyl, m-isopropenylphenyl, o-vinylphenyl, o-isopropenylphenyl, p-vinylbenzyl, p-isopropenylbenzyl, m-vinylbenzyl, m-isopropenylbenzyl, o-vinylbenzyl, o-isopropenylbenzyl, p-vinylphenylvinyl, p-vinylphenylpropenyl, p-vinylphenylbutenyl, m-vinylphenylvinyl, m-vinylphenylpropenyl, m-vinylphenylbutenyl, o-vinylphenylvinyl Substituents containing unsaturated bonds such as hydroxyl, carboxyl, carbonyl, thiocarbonyl, acyl halide, anhydride, carboxylic acid, thiocarboxylic acid, aldehyde, thialdehyde, carboxylate, amide, sulfonic acid, sulfonate, phosphoric acid, phosphate, amino, imino, nitrile, pyridine, quinolyl, epoxy, thioepoxy, thioether, isocyanate, isothiocyanate, halogenated silicon, silanol, alkoxysilyl, halogenated tin, boric acid, borate, alkoxytin and phenyltin are preferably substituents containing functional groups such as phenyltin. From the aspect of curability, it is preferred to have any polar group for the purpose of having free radical reactivity and/or reactivity with the component (IV) curing agent.

From the perspective of curability of the resin composition of this embodiment, the molecular weight of the polyphenylene ether resin as component (III) is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 10,000 or less. The polyphenylene ether resin may be linear, crosslinked, or branched.

The liquid crystal polyester resin as the component (III) is a polyester that forms an anisotropic melt phase and may be any resin as long as it falls within the category of a liquid crystal polyester resin.

For example, "X7G" manufactured by Eastman Kodak Company, Xydar manufactured by Datorco Corporation, Ekonol manufactured by Sumitomo Chemical Co., Ltd., Vectra manufactured by Celanese Corporation, and the like can be cited.

The fluorine-based resin as the component (III) may be any resin that falls within the category of fluorine-based resins and is an olefin-based polymer containing a fluorine group.

Examples of the fluorine-based resin include polytetrafluoroethylene, perfluoroalkoxyalkane, ethylene-tetrafluoroethylene copolymer, perfluoroethylene-propylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, and ethylene-chlorotrifluoroethylene copolymer.

The epoxy resin as the component (III) may be any resin as long as it falls within the category of epoxy resins, and preferably has two or more epoxy groups in one molecule from the viewpoint of strength.

The epoxy resin may be used alone or in combination of two or more.

Examples of the epoxy resin 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, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidylester-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, spiro-ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins.

In addition, from the perspective of reactivity, when an epoxy resin is used as component (III), it is preferably also contained as component (IV) a curing agent. In this case, the polar group possessed by the component (IV) curing agent includes, for example, a carboxyl group, an imidazole group, a hydroxyl group, an amino group, a thiol group, a benzoxazine group, and a carbodiimide group. From the perspective of reactivity, a carboxyl group, an imidazole group, a hydroxyl group, a benzoxazine group, and a carbodiimide group are preferred. From the perspective of dielectric properties, a hydroxyl group, a carboxyl group, an imidazole group, a benzoxazine group, and a carbodiimide group are more preferred. A hydroxyl group, a carboxyl group, and a carbodiimide group are further preferred.

In addition, when two or more polar resins with different free radical reactivity are used as component (III), from the perspective of curability, it is preferred to use component (II): a free radical initiator and component (IV): a curing agent in combination. For example, when a maleimide-type polyimide resin having excellent free radical reactivity and a bisphenol A epoxy resin having no free radical reactivity are used as component (III), from the perspective of curability, it is preferred to add the above-mentioned component (II) a free radical initiator and the above-mentioned component (IV) a curing agent.

In addition, when a polar resin with a high melting point and high rigidity is used as component (III): polar resin, the resin composition of this embodiment may not contain component (IV). As component (III), the high melting point and high rigidity resin may include, for example, liquid crystal polyester resin, polytetrafluoroethylene and other fluorine resins.

When the component (III) has a high melting point and high rigidity, the strength required for practical use tends to be obtained even when the component (IV) is not contained.

(Ingredient (V): additive)

The resin composition of the present embodiment may further contain various additives such as a curing accelerator, a filler, and a flame retardant as a component (V).

Furthermore, substances contained as additives of the block copolymer of component (I) have the same meaning as component (V) of the above-mentioned resin composition.

The curing accelerator is added to promote the reactivity between the above-mentioned components, and any known curing accelerator can be used, such as phosphorus curing accelerators, amine curing accelerators, imidazole curing accelerators, guanidine curing accelerators, and metal curing accelerators.

The curing accelerator may be used alone or in combination of two or more.

Phosphorus-based curing accelerators include, but are not limited to, triphenylphosphine, phosphonium borate compounds, tetraphenylboron tetraphenylphosphine, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, and the like, preferably triphenylphosphine and tetrabutylphosphonium decanoate.

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

Examples of the imidazole curing accelerator include, but are not limited to, 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, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4- Imidazole compounds such as diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, isocyanuric acid adduct of 2-phenylimidazole, isocyanuric acid adduct of 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and adducts of imidazole compounds with epoxy resins, preferably 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

As the imidazole-based curing accelerator, a commercially available item may be used, and examples thereof include P200-H50 manufactured by Mitsubishi Chemical Corporation.

Examples of the guanidine-based curing accelerator include, but are not limited to, dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, and 1-(o-tolyl)biguanidine. Preferred examples include dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene.

Examples of the metal curing accelerator include, but are not limited to, organic metal complexes or organic metal salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin.

Specific examples of the organic metal complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, organic zinc complexes such as zinc (II) acetylacetonate, organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate.

Specific examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, zinc stearate, and the like.

Examples of fillers include, but are not limited to, inorganic fillers such as silicon oxide, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, calcium sulfate, barium sulfate, carbon black, glass fiber, glass beads, glass hollow spheres, glass flakes, graphite, titanium oxide, potassium titanate whiskers, carbon fiber, aluminum oxide, kaolin, silicic acid, calcium silicate, quartz, mica, talc, clay, zirconium oxide, potassium titanate, aluminum oxide, and metal particles; and organic fillers such as wood chips, wood powder, pulp, and cellulose nanofibers.

These fillers may be used alone or in combination of plural types.

The shapes of these fillers are not particularly limited and may be any of flaky, spherical, granular, powdery, and amorphous shapes.

The resin composition or cured product of the present embodiment is often exposed to high temperatures during molding, and in order to prevent shrinkage and deformation of the molded body due to temperature changes, the filler preferably has a small linear expansion coefficient. From the aspect of reducing the linear expansion coefficient, silicon oxide is preferably used as the filler, and silicon oxide includes, for example, amorphous silicon oxide, fused silicon oxide, crystalline silicon oxide, synthetic silicon oxide, hollow silicon oxide, etc.

Examples of flame retardants include, but are not limited to, halogen flame retardants such as bromine compounds, phosphorus flame retardants such as aromatic compounds, metal hydroxides, alkyl sulfonates, antimony trioxide, aluminum hydroxide, magnesium hydroxide, zinc borate, hexabromobenzene, decabromodiphenylethane, 4,4-dibromobiphenyl, ethylenebistetrabromophthalimide and other flame retardants containing aromatic bromine compounds.

These flame retardants are used alone or in combination of two or more.

The flame retardants mentioned above also include so-called flame retardant auxiliary agents which, although they have a low flame retardancy-developing effect by themselves, can synergistically demonstrate a more excellent effect by being used in combination with other flame retardants.

The filler and the flame retardant may be those which have been surface-treated in advance with a surface treatment agent such as a silane coupling agent.

Examples of the surface treatment agent include, but are not limited to, fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, titanate coupling agents, etc. These may be used alone or in combination of a plurality of them.

There are no particular limitations on other additives as long as they are additives commonly used in compounding resin compositions and/or cured products.

Examples of the other additives include, but are not limited to: pigments and/or colorants such as carbon black and titanium oxide; lubricants such as stearic acid, behenic acid, zinc stearate, calcium stearate, magnesium stearate, and ethylene bisstearamide; anti-sticking agents; plasticizers such as organic polysiloxanes, phthalate esters, adipic acid ester compounds, azelaic acid ester compounds, and mineral oils; antioxidants such as hindered phenol and phosphorus heat stabilizers; hindered amine light stabilizers; benzotriazole ultraviolet absorbers; antistatic agents; organic fillers; thickeners; defoamers; leveling agents; resin additives such as adhesion-imparting agents; other additives or mixtures thereof, etc.

From the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent, the resin composition of the present embodiment preferably does not contain a pigment, a colorant, a lubricant, a release agent, or an antistatic agent.

The resin composition in the present embodiment may be obtained by melt-kneading the components or by dissolving the components in a solvent in which they can be dissolved and stirred (hereinafter referred to as "varnish"). From the viewpoint of handling properties, varnish is preferred.

Examples of the solvent include, but are not limited to, ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, and γ-butyrolactone; acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, and diethylene glycol monoethyl ether monoacetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone, etc. The organic solvent may be used alone or in combination of two or more.

[Solidified material]

The cured product of the present embodiment includes the block copolymer of the present embodiment described above.

The cured product of the present embodiment is obtained by subjecting the resin composition of the present embodiment to a curing reaction at an arbitrary temperature and time, and includes not only a completely cured product but also a product in which only a portion of the resin composition is cured and contains uncured components (semi-cured).

In the process of producing the laminate described later, a step of further curing the cured product may be performed.

The reaction temperature of the curing process of the cured product of the present embodiment is preferably 80°C or more, more preferably 100°C or more, and further preferably 120°C or more. As the reaction time, it is preferably 10 to 240 minutes, more preferably 20 to 230 minutes, and further preferably 30 to 220 minutes. In the case where the resin composition of the present embodiment is a varnish, it is preferably subjected to a curing reaction after the solvent is removed. As a drying method, it can be implemented by existing known methods such as heating and hot blowing, preferably at a temperature lower than the curing reaction temperature, and with regard to the amount of solvent in the resin composition, it is preferably dried to less than 10% by mass, and more preferably dried to less than 5% by mass.

[Resin film]

The resin film of this embodiment is composed of the resin composition of this embodiment.

The resin film of this embodiment is obtained by spreading a varnish composed of the resin composition of this embodiment described above on an appropriate support into a uniform thin film and performing a drying treatment as described above to remove the solvent. The resin film can be stored in a roll.

The resin film of the present embodiment may have a structure in which a predetermined protective film is laminated. In this case, the resin film can be used by peeling off the protective film.

Examples of the support include films made of plastic materials, metal foils, and release papers.

The film composed of plastic material as a support body can be cited, but is not limited to, for example: polyesters such as polyethylene terephthalate and polyethylene naphthalate; acrylics such as polycarbonate and polymethyl methacrylate (PMMA); cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. From the perspective of availability and cost, polyethylene terephthalate and polyethylene naphthalate are preferred.

As metal foil, for example, copper foil, aluminum foil, etc. can be cited but not limited to, copper foil is preferred. As copper foil, a foil composed of a single metal of copper can be used, and a foil composed of an alloy of copper and other metals (such as tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) can also be used.

The support may also be subjected to roughening treatment, corona treatment, antistatic treatment, or anti-sticking treatment on the surface to be bonded to the resin composition layer.

[Prepreg]

The prepreg of the present embodiment includes a base material and the resin composition of the present embodiment impregnated or coated on the base material. That is, the prepreg of the present embodiment is a composite of the resin composition of the present embodiment and the base material.

The prepreg is obtained, for example, by impregnating a substrate such as glass cloth with the varnish which is the resin composition of the present embodiment described above, and then removing the solvent by the above-mentioned drying method.

As the substrate, there can be cited, but not limited to, for example: various glass cloths such as coarse yarn cloth, cloth, chopped strand mat, surface felt pad, etc.; 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 wholly aromatic polyamide fibers, wholly aromatic polyester fibers, polybenzoxazole fibers, etc.; natural fiber cloths such as cotton cloth, linen, felt, etc.; natural cellulose-based substrates such as carbon fiber cloth, kraft paper, cotton paper, cloth obtained from paper-glass mixed fibers, etc.; polytetrafluoroethylene porous membranes, etc. From the perspective of dielectric properties, glass cloth is preferred.

These substrates can be used alone or in combination of two or more.

The ratio of the solid content of the resin composition of the present embodiment in the prepreg is preferably 30 to 80% by mass, more preferably 40 to 70% by mass. By making the above ratio 30% by mass or more, when the prepreg is used for electronic substrates, etc., there is a tendency for better insulation reliability. By making the above ratio 80% by mass or less, in the use of electronic substrates, there is a tendency for better mechanical properties such as rigidity.

[Laminate]

The laminated body of the present embodiment comprises the above-mentioned resin film and metal foil. In addition, the laminated body of the present embodiment comprises a cured product of the above-mentioned prepreg and metal foil.

The laminate of the present embodiment can be manufactured, for example, through the following steps: step (a) of laminating a resin film composed of the resin composition of the present embodiment on a substrate to form a resin layer to obtain a prepreg; step (b) of heating and pressurizing the above-mentioned resin layer to flatten it to obtain a cured product of the prepreg; and step (c) of further forming a specified wiring layer composed of metal foil on the above-mentioned resin layer, etc.

In step (a), the method of laminating the resin film on the substrate is not particularly limited, and examples thereof include a multi-stage press, a vacuum press, a normal pressure laminator, and a method of laminating using a laminator that heats and presses under vacuum, etc., and a method using a laminator that heats and presses under vacuum is preferred. In the method using the laminator, even if the target electronic circuit substrate has a fine wiring circuit on the surface, the circuits can be embedded with resin without gaps. In addition, the lamination can be batch-type or continuous-type using a roller or the like.

As the substrate, there can be mentioned, but not limited to, various substrates constituting the above-mentioned prepreg, and for example, glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, polyphenylene ether-based substrates, fluororesin substrates, etc. The surface of the laminated resin layer of the substrate may be roughened in advance, and the number of substrate layers is not limited.

In the above step (b), the resin film and the substrate laminated in the above step (a) are flattened by applying pressure under heating. The conditions can be arbitrarily adjusted according to the type of substrate and the composition of the resin film, for example, the temperature is preferably in the range of 100 to 300°C, the pressure is 0.2 to 20 MPa, and the time is 30 to 180 minutes.

In the above step (c), the resin film and the substrate are pressed under heating, and a predetermined wiring layer composed of metal foil is further formed on the produced resin layer. The formation method is not particularly limited, and existing known methods can be cited, such as etching methods such as subtractive methods, semi-additive methods, etc.

The subtractive method is a method in which a resist layer having a shape corresponding to a desired pattern shape is formed on a metal layer, and the metal layer in a portion where the resist has been removed is dissolved and removed with a reagent by subsequent development treatment, thereby forming desired wiring.

The semi-additive method is a method in which a metal coating is formed on the surface of a resin layer by electroless plating, a plating resist layer having a shape corresponding to a desired pattern is formed on the metal coating, and then, after a metal layer is formed by electroplating, unnecessary electroless plating is removed using a reagent or the like to form a desired wiring layer.

In addition, holes such as via holes can be formed in the resin layer as needed, and the method for forming the hole is not particularly limited, and existing known methods can be used. As the method for forming the hole, for example, NC drill, carbon dioxide laser, UV laser, YAG laser, plasma, etc. can be used.

[Metal-clad laminate]

The laminated body of the present embodiment described above may be in a plate shape or may be a flexible laminated body having flexibility.

The laminated body of the present embodiment may be a metal-clad laminate.

The metal-clad laminate is obtained by laminating and curing the resin composition of the present embodiment or the prepreg of the present embodiment and a metal foil, and a part of the metal foil is removed from the metal-clad laminate.

The metal-clad laminate preferably has a form in which a cured product of a prepreg (also referred to as a "cured product composite") and a metal foil are laminated and closely adhered to each other, and is suitable as a material for an electronic circuit board.

Examples of the metal foil include, but are not limited to, aluminum foil and copper foil. Among them, copper foil is preferred because of its low electrical resistance.

The cured product of the prepreg combined with the metal foil may be a single sheet or a plurality of sheets, and the metal foil may be laminated on one or both sides of the cured product to form a laminate depending on the application.

As a method for producing the above-mentioned laminated board, for example, the following method can be cited: a prepreg composed of the resin composition of this embodiment and a substrate is formed, and after overlapping it with a metal foil, the resin composition is cured to obtain a laminated board in which the cured prepreg and the metal foil are laminated.

One of the particularly preferred uses of the laminate is a printed circuit board. The printed circuit board is preferably a metal-clad laminate in which at least a portion of the metal foil is removed.

The above-mentioned printed circuit board can be made by a method for pressurizing and heating molding using the prepreg of the above-mentioned present embodiment. As a substrate, the same substrate as the substrate described in the above-mentioned prepreg can be used. The above-mentioned printed circuit board has excellent strength and electrical properties (low dielectric constant and low dielectric loss tangent) by comprising the resin composition of the present embodiment, and then, it is possible to suppress the change of electrical properties accompanied by environmental changes, and has excellent insulation reliability and mechanical properties.

[Materials for electronic circuit boards]

The material for an electronic circuit board of the present embodiment includes a cured product of the resin composition of the present embodiment.

The material for the electronic circuit board of the present embodiment can be produced using the resin composition and/or varnish of the present embodiment described above.

The material for the electronic circuit board of the present embodiment comprises at least one selected from the group consisting of a cured product of the above-mentioned resin composition, a resin film comprising the resin composition of the present embodiment or its cured product, and a composite prepreg of a substrate and a resin composition. The material for the electronic circuit board of the present embodiment can be used as a printed circuit board having a metal foil with a resin.

Example

The present embodiment will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples and comparative examples.

The methods for identifying the structure and measuring the physical properties of the block copolymer (component (I)) used in the following Examples and Comparative Examples are as follows.

[Methods for determining polymer structure and physical properties]

((1) Content of vinyl aromatic monomer units in block copolymer)

Using the block copolymer before hydrogenation, the content of the vinyl aromatic monomer unit in the block copolymer was measured using an ultraviolet spectrophotometer (UV-2450 manufactured by Shimadzu Corporation).

((2) Vinyl bond content of block copolymer)

The amount of vinyl bonds was measured using an infrared spectrophotometer (FT/IR-230, manufactured by JASCO Corporation) using the block copolymer before hydrogenation.

The vinyl bond content of the block copolymer was calculated by the Hampton method.

This value is defined as the content of the unit (a) derived from 1,2-bond and/or 3,4-bond when the total content of the polymer block (B) and/or the polymer block (C) of the component (I) block copolymer is taken as 100%.

((3) Molecular weight and molecular weight distribution of block copolymers)

The molecular weight of the block copolymer of component (I) before modification and hydrogenation was measured by GPC [apparatus: LC-10 (manufactured by Shimadzu Corporation), column: TSKgel GMHXL (4.6 mm×30 cm)].

Tetrahydrofuran was used as a solvent. Regarding the measurement conditions, the measurement was performed at a temperature of 35°C.

The molecular weight is a weight average molecular weight obtained by determining the molecular weight of the peak of the chromatogram using a calibration curve determined by measurement of commercially available standard polystyrene (created using the peak molecular weight of standard polystyrene).

When there are a plurality of peaks in the chromatogram, the molecular weight is an average molecular weight obtained from the molecular weight of each peak and the composition ratio of each peak (obtained from the area ratio of each peak in the chromatogram).

The molecular weight distribution is the ratio (Mw/Mn) of the obtained weight average molecular weight (Mw) to the number average molecular weight (Mn).

((4) Hydrogenation rate of double bonds of conjugated diene monomer units in block copolymer)

The hydrogenated block copolymer of component (I) was used to measure the hydrogenation rate of the double bonds of the conjugated diene monomer units using a nuclear magnetic resonance apparatus (DPX-400 manufactured by BRUKER).

[Material for block copolymer and resin composition]

(Preparation of Hydrogenation Catalyst)

In the Examples and Comparative Examples described below, the hydrogenation catalyst used in producing the block copolymer was prepared by the following method.

A reaction container equipped with a stirring device was purged with nitrogen, and 1 liter of dried and purified cyclohexane was added thereto.

Next, 100 mmol of bis(η5-cyclopentadienyl)titanium dichloride was added. While the mixture was fully stirred, a n-hexane solution containing 200 mmol of trimethylaluminum was added and the mixture was reacted at room temperature for about 3 days. Thus, a hydrogenation catalyst was obtained.

(Component (I): block copolymer)

The block copolymer of a vinyl aromatic compound and a conjugated diene was prepared as follows.

The structure and physical property values of each block copolymer are shown in Tables 1 and 2.

It should be noted that in the table, (A) represents a polymer block (A) mainly composed of vinyl aromatic monomer units, (B) represents a polymer block (B) mainly composed of conjugated diene monomer units, and (C) represents a polymer block (C) composed of vinyl aromatic monomer units and conjugated diene monomer units.

<Block copolymer (1)>

Batch polymerization was carried out using a tank-type reactor (internal volume 10 L) equipped with a stirring device and a jacket.

First, a cyclohexane solution (concentration: 20% by mass) containing 37.5 parts by mass of styrene was charged into the tank reactor.

Next, 0.23 parts by mass of n-butyl lithium based on 100 parts by mass of all monomers and 0.8 mol of tetramethylethylenediamine (TMEDA) based on 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 45 minutes.

Next, a cyclohexane solution containing 25 parts by mass of butadiene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 20 minutes.

Next, a cyclohexane solution containing 37.5 parts by mass of styrene (concentration: 20% by mass) was added and polymerization was carried out for 45 minutes. Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer.

The block copolymer obtained in this manner had a styrene content of 75% by mass, a weight average molecular weight of 3.0×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 70%.

<Block copolymer (2)>

A polymerization reaction was carried out in the same manner as in the above block copolymer (1) except that 0.36 parts by mass of n-butyllithium was added based on 100 parts by mass of all monomers.

The block copolymer obtained in this manner had a styrene content of 75% by mass, a weight average molecular weight of 2.1×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 70%.

<Block copolymer (3)>

A polymerization reaction was carried out in the same manner as in the block copolymer (1) except that 0.65 parts by mass of n-butyl lithium was added relative to 100 parts by mass of all monomers and 1.2 mol of tetramethylethylenediamine (TMEDA) was added relative to 1 mol of n-butyl lithium.

The block copolymer obtained in this manner had a styrene content of 75% by mass, a weight average molecular weight of 1.0×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 71%.

<Block copolymer (4)>

A polymerization reaction was carried out in the same manner as in the above block copolymer (3) except that 1.42 parts by mass of n-butyllithium was added based on 100 parts by mass of all monomers.

The block copolymer obtained in this manner had a styrene content of 75% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 69%.

<Block copolymer (5)>

A polymerization reaction was carried out in the same manner as in the above block copolymer (3) except that 3.20 parts by mass of n-butyllithium was added based on 100 parts by mass of all monomers.

The block copolymer (5) obtained in this manner had a styrene content of 75% by mass, a weight average molecular weight of 0.2×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 70%.

<Block copolymer (6)>

Batch polymerization was carried out using a tank-type reactor (internal volume 10 L) equipped with a stirring device and a jacket.

First, a cyclohexane solution (concentration: 20% by mass) containing 27.5 parts by mass of styrene was charged into the tank-type reactor.

Next, 1.42 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 1.2 mol of tetramethylethylenediamine (TMEDA) relative to 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 45 minutes.

Next, a cyclohexane solution containing 45 parts by mass of butadiene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 20 minutes.

Next, a cyclohexane solution containing 27.5 parts by mass of styrene (concentration: 20% by mass) was added and polymerization was carried out for 45 minutes. Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer.

The block copolymer (6) obtained in this manner had a styrene content of 55% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 69%.

<Block copolymer (7)>

Batch polymerization was carried out using a tank-type reactor (internal volume 10 L) equipped with a stirring device and a jacket.

First, a cyclohexane solution (concentration: 20% by mass) containing 45 parts by mass of styrene was charged into the above-mentioned tank-type reactor.

Next, 1.42 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 1.2 mol of tetramethylethylenediamine (TMEDA) relative to 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 45 minutes.

Next, a cyclohexane solution containing 10 parts by mass of butadiene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 20 minutes.

Next, a cyclohexane solution containing 45 parts by mass of styrene (concentration: 20% by mass) was added and polymerized for 45 minutes. Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer.

The block copolymer (7) obtained in this manner had a styrene content of 90% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 70%.

<Block copolymer (8)>

A polymerization reaction was carried out in the same manner as in the above block copolymer (4) except that 0.1 mol of TMEDA was added to 1 mol of n-butyllithium.

The block copolymer (8) obtained in this manner had a styrene content of 75% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 31%.

<Block copolymer (9)>

A polymerization reaction was carried out in the same manner as in the above block copolymer (8), except that 0.1 mol of TMEDA was added to 1 mol of n-butyllithium and the polymerization time of each block was extended by 5 minutes.

The block copolymer (9) obtained in this manner had a styrene content of 75% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 16%.

<Hydrogenated block copolymer (10)>

The same polymerization operation as the block copolymer (4) was performed. Then, the hydrogenation catalyst prepared as described above was added to the obtained block copolymer in an amount of 90 ppm based on Ti per 100 parts by mass of the block copolymer, and a hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 80° C. for about 0.15 hours to obtain a hydrogenated block copolymer (10).

The hydrogenated block copolymer (10) obtained as described above had a styrene content of 75% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 70%, and a hydrogenation rate of 22%.

<Hydrogenated block copolymer (11)>

A hydrogenated block copolymer (11) was obtained by carrying out the same operation as in the above hydrogenated block copolymer (10) except that the hydrogenation reaction was carried out for 0.35 hours.

The hydrogenated block copolymer (11) obtained as described above had a styrene content of 75% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 69%, and a hydrogenation rate of 51%.

<Hydrogenated block copolymer (12)>

A hydrogenated block copolymer (12) was obtained by carrying out the same operation as in the above hydrogenated block copolymer (10) except that the hydrogenation reaction was carried out for 0.75 hours.

The hydrogenated block copolymer (12) obtained as described above had a styrene content of 75% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 71%, and a hydrogenation rate of 72%.

<Block copolymer (13)>

Batch polymerization was carried out using a tank-type reactor (internal volume 10 L) equipped with a stirring device and a jacket.

First, a cyclohexane solution (concentration: 20% by mass) containing 30 parts by mass of styrene was charged into the above-mentioned tank-type reactor.

Next, 1.42 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 1.2 mol of tetramethylethylenediamine (TMEDA) relative to 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 25 minutes.

Next, a cyclohexane solution (concentration: 20% by mass) containing 15 parts by mass of styrene and 25 parts by mass of butadiene was added, and polymerization was carried out at 70° C. for 35 minutes.

Next, a cyclohexane solution containing 30 parts by mass of styrene (concentration: 20% by mass) was added and polymerization was carried out for 25 minutes. Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer (13).

The block copolymer (13) obtained as described above had a styrene content of 75% by mass, a weight average molecular weight of 0.5×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond amount: unit (a)/amount of conjugated diene monomer units in polymer block (C)) of 69%.

<Block copolymer (14)>

A block copolymer (14) was obtained by the same operation as the block copolymer (3) except that 2.0 mol of TMEDA was added to n-butyl lithium, the reaction temperature was set to 50°C, and the reaction time of each block was extended by 20 minutes. The obtained block copolymer (14) had a styrene content of 75% by mass, a weight average molecular weight of 1.0×10 ⁴ , a molecular weight distribution of 1.13, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 88%.

<Block copolymer (15)>

Batch polymerization was carried out using a tank-type reactor (internal volume 10 L) equipped with a stirring device and a jacket.

First, a cyclohexane solution containing 25 parts by mass of styrene (concentration: 20% by mass) was added.

Next, 0.45 parts by mass of n-butyl lithium based on 100 parts by mass of all monomers and 0.8 mol of tetramethylethylenediamine (TMEDA) based on 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 20 minutes.

Next, a cyclohexane solution (concentration: 20% by mass) containing 50 parts by mass of styrene and 25 parts by mass of butadiene was added, and polymerization was carried out at 70° C. for 30 minutes.

Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer (15).

The block copolymer (15) obtained as described above had a styrene content of 75% by mass, a weight average molecular weight of 1.5×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond amount: unit (a)/amount of conjugated diene monomer units in polymer block (C)) of 71%.

<Block copolymer (16)>

Batch polymerization was carried out using a tank-type reactor (internal volume 10 L) equipped with a stirring device and a jacket.

First, a cyclohexane solution (concentration: 20% by mass) containing 22.5 parts by mass of styrene was charged into the tank reactor.

Next, 0.65 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 1.2 mol of tetramethylethylenediamine (TMEDA) relative to 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 15 minutes.

Next, a cyclohexane solution containing 55 parts by mass of butadiene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 30 minutes.

Next, a cyclohexane solution containing 22.5 parts by mass of styrene (concentration: 20% by mass) was added and polymerized for 20 minutes. Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer (16).

The block copolymer (16) obtained in the above manner had a styrene content of 45% by mass, a weight average molecular weight of 1.0×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 71%.

<Block copolymer (17)>

A block copolymer (17) was obtained by carrying out the same operation as in the block copolymer (3) except that the amount of n-butyllithium was changed to 0.17 parts by mass based on 100 parts by mass of all monomers.

The block copolymer (17) obtained in the above manner had a styrene content of 75% by mass, a weight average molecular weight of 4.0×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond content: units (a)/polymer block (B)) of 71%.

<Block copolymer (18)>

Batch polymerization was carried out using a tank-type reactor (internal volume 10 L) equipped with a stirring device and a jacket.

First, a cyclohexane solution (concentration: 20% by mass) containing 7.5 parts by mass of butadiene was charged into the tank-type reactor.

Next, 0.65 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 1.2 mol of tetramethylethylenediamine (TMEDA) relative to 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 5 minutes.

Next, a cyclohexane solution (concentration: 20% by mass) containing 10 parts by mass of butadiene and 75 parts by mass of styrene was added, and polymerization was carried out at 70° C. for 30 minutes.

Next, a cyclohexane solution containing 7.5 parts by mass of butadiene (concentration: 20% by mass) was added and polymerized for 5 minutes, and then methanol was added to terminate the polymerization reaction, thereby obtaining a block copolymer (18).

The block copolymer (18) obtained as described above had a styrene content of 75% by mass, a weight average molecular weight of 1.0×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond amount: unit (a)/(amount of conjugated diene monomer units in polymer block (B)+polymer block (C))) of 70%.

<Block copolymer (19)>

Batch polymerization was carried out using a tank-type reactor (internal volume 10 L) equipped with a stirring device and a jacket.

First, a cyclohexane solution (concentration: 20% by mass) containing 25 parts by mass of butadiene and 75 parts by mass of styrene was charged into the above-mentioned tank-type reactor.

Next, 1.42 parts by mass of n-butyl lithium based on 100 parts by mass of all monomers and 1.2 mol of tetramethylethylenediamine (TMEDA) based on 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 60 minutes to obtain a block copolymer (19).

The block copolymer (19) obtained as described above had a styrene content of 75% by mass, a weight average molecular weight of 1.0×10 ⁴ , a molecular weight distribution of 1.10, and a content of units (a) derived from 1,2-bonds and/or 3,4-bonds (vinyl bond amount: unit (a)/amount of conjugated diene monomer units in block (C)) of 70%.

(Component (II): free radical initiator)

Perbutyl C (manufactured by NOF Corporation)

Percumyl D (manufactured by NOF Corporation)

(Component (III): polar resin)

As the polar resin, a polyphenylene ether-based resin (PPE) was polymerized as follows.

0.2512 g of cupric chloride dihydrate, 1.1062 g of 35% hydrochloric acid, 3.6179 g of di-n-butylamine, 9.5937 g of N,N,N',N'-tetramethylpropylenediamine, 211.63 g of methanol and 493.80 g of n-butanol, and 180.0 g of 2,6-dimethylphenol containing 5 mol% of 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane were added to a 1.5-liter jacketed reactor. The reactor was equipped with a nozzle for introducing oxygen-containing gas, stirring turbine blades and baffles at the bottom of the reactor, and a reflux cooler in the exhaust line at the top of the reactor.

The mass ratio of the solvent used was n-butanol:methanol = 70:30. Then, oxygen was introduced into the reactor from the nozzle at a rate of 180 mL/min while stirring vigorously, and a heat medium was passed through the jacket to adjust the polymerization temperature to 40°C.

The polymer solution gradually becomes a slurry.

When the polyphenylene ether reaches the desired number average molecular weight, the oxygen-containing gas aeration is stopped and the obtained polymerization mixture is heated to 50° C. Then, hydroquinone (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) is added little by little and the mixture is kept at 50° C. until the slurry-like polyphenylene ether turns white.

Next, 720 g of a methanol solution containing 6.5% by mass of 36% hydrochloric acid was added, and the mixture was filtered and repeatedly washed with methanol to obtain a wet polyphenylene ether.

Then, the product was dried in vacuum at 100°C to obtain dry polyphenylene ether. ηsp/c was 0.103 dL/g, and the yield was 97%.

In the measurement of ηsp/c, the polyphenylene ether was prepared into a 0.5 g/dL chloroform solution, and the reduced viscosity (ηsp/c) at 30° C. was determined using an Ubbelohde viscometer. The unit is dL/g.

The obtained polyphenylene ether was modified as follows.

Mix 152.5 g of polyphenylene ether and 152.5 g of toluene and heat to about 85°C. Then, add 2.1 g of dimethylaminopyridine. When all the solids are dissolved, slowly add 18.28 g of methacrylic anhydride. Mix the obtained solution continuously while maintaining it at 85°C for 3 hours. Then, cool the solution to room temperature to obtain a toluene solution of methacrylate-terminated polyphenylene ether. For the obtained toluene solution, add 1000 mL of 10°C methanol little by little in a cylindrical 3L SUS container with a homogenizer. Filter the obtained powder, wash with methanol, and dry it at 85°C under nitrogen for 18 hours.

(Component (IV): curing agent)

Triallyl isocyanurate (TAIC ^™ ) (manufactured by Mitsubishi Chemical Corporation)

[Method for measuring physical properties of resin composition]

((1) Dielectric loss tangent and dielectric constant)

The dielectric loss tangent at 10 GHz was measured using the cavity resonance method.

As measurement devices, a network analyzer (N5230A, manufactured by Agilent Technologies) and a cavity resonator (Cavity Resornator CP series) manufactured by Kanto Denshi Application Development Co., Ltd. were used.

Regarding the measurement sample, a test piece of 2.6 mm in width×80 mm in length was cut out from a cured film described later, and this was used as the measurement sample.

The following Examples and Comparative Examples were evaluated according to the following criteria using the dielectric loss tangent and dielectric constant obtained above.

<Evaluation Criteria in (Examples 1 to 17) and (Comparative Examples 1 to 7)>

Dielectric loss tangent

◎：0.004 or less

○: 0.005 or less

△: less than 0.006

×: 0.006 or more

Dielectric constant

◎：2.23 or less

○: 2.27 or less

△: less than 2.30

×: 2.30 or more

<Evaluation Criteria in (Examples 18 to 27) and (Comparative Examples 8 to 18)>

Evaluation was performed using the difference in dielectric loss tangent and dielectric constant between Comparative Example 8 not including a block copolymer and each of the Examples or Comparative Examples (Comparative Example 8 - Examples or Comparative Examples).

Dielectric loss tangent

◎: 0.0012 or more

○: 0.0010 or more and less than 0.0012

△: 0.0080 or more and less than 0.0010

×: Less than 0.0080 (including the same value and positive difference)

Dielectric constant

◎: 0.12 or more

○: 0.10 or more and less than 0.12

△: 0.08 or more and less than 0.10

×: less than 0.08 (including the same value and positive difference)

<Evaluation Criteria in (Examples 28 to 43) and (Comparative Examples 19 to 40)>

Evaluation was performed using the difference in dielectric loss tangent and dielectric constant between Comparative Example 19 not including a block copolymer and each of the Examples or Comparative Examples (Comparative Example 19-Examples or Comparative Examples).

Dielectric loss tangent

◎: 0.010 or more

○: 0.008 or more and less than 0.010

△: 0.005 or more and less than 0.008

×: Less than 0.005 (including the same value and positive difference)

Dielectric constant

◎: 0.4 or more

○: 0.3 or more and less than 0.4

△: 0.2 or more and less than 0.3

×: less than 0.2 (including the same value and positive difference)

<Evaluation Criteria in (Examples 44 to 55) and (Comparative Examples 41 to 55)>

Evaluation was performed using the difference in dielectric loss tangent and dielectric constant between Comparative Example 41 not including a block copolymer and each of the Examples or Comparative Examples (Comparative Example 41 - Examples or Comparative Examples).

Dielectric loss tangent

◎: 0.0012 or more

○: 0.0010 or more and less than 0.0012

△: 0.0080 or more and less than 0.0010

×: Less than 0.0080 (including the same value and positive difference)

Dielectric constant

◎: 0.15 or more

○: 0.12 or more and less than 0.15

△: 0.10 or more and less than 0.12

×: less than 0.10 (including the same value and positive difference)

((2) Strength (glass transition temperature: Tg))

The dynamic viscoelasticity of the resin compositions of Examples and Comparative Examples described below was measured, and the temperature at which tan δ was maximum was determined as the glass transition temperature (Tg).

A high Tg indicates high strength over a wide temperature range.

ARES (trade name, manufactured by TA Instruments) was used as the measuring device in the tensile mode. A test piece having a length of 35 mm, a width of about 12.5 mm, and a thickness of 0.3 mm was cut out from a cured film described later and used as a measuring sample.

The measurement was performed at a frequency of 10 rad/s and a measurement temperature of -150 to 270°C.

((3) Storage stability)

The varnishes of Examples and Comparative Examples described below were left to stand at 30°C/50%RH and the state was observed. The number of days until layer separation and/or the presence or absence of precipitation of gel-like components were evaluated according to the following criteria.

◎: More than 120 days (including no precipitation)

○: More than 90 days

△: More than 30 days

×: Less than 30 days

[Preparation of resin composition]

(Examples 1 to 27), (Comparative Examples 1 to 18)

Using the above ingredients, a resin composition was prepared by the following preparation method.

The component ratios and physical properties are shown in Tables 3 to 6 below.

First, each component was added to toluene (special grade product manufactured by Wako Pure Chemical Industries, Ltd. was used as it is) and stirred to dissolve, thereby preparing a varnish having a concentration of 20% by mass to 50% by mass.

The varnish was applied onto a release-treated KAPTON film at a speed of 30 mm/sec, and then dried at 100°C for 30 minutes in a nitrogen stream using a blower dryer to obtain a film. The obtained film was subjected to a curing reaction at 200°C for 90 minutes in a nitrogen stream using a blower dryer to obtain a cured film.

The above-mentioned cured product film was provided as an evaluation sample.

It is clear from Examples 1 to 27 and Comparative Examples 1 to 18 that the cured product of the resin composition using the block copolymer of the present invention is excellent in the balance among dielectric properties, strength, and heat resistance.

As described above, it is clear that the cured product of the resin composition containing the block copolymer of the present invention is suitable for use in glass cloth and printed wiring boards using a metal laminate.

(Examples 28 to 43), (Comparative Examples 19 to 40)

In addition to the above components, the following components were used to prepare a resin composition according to the following preparation method.

<Component (II): Free Radical Initiator>

Perbutyl P-90 (manufactured by NOF Corporation)

<Component (III): Polar Resin>

Bisphenol A type epoxy resin EXA-850CRP (manufactured by DIC Corporation)

Phenoxy resin YP-50S (manufactured by Nippon Steel Chemical Co., Ltd.)

<Component (IV): Curing Agent>

1-Benzyl-2-phenylimidazole (Tokyo Chemical Industry Co., Ltd.)

Phenolic curing agent KA-1163 (manufactured by DIC Corporation)

The component ratios and physical properties are shown in Tables 7 to 9 below.

First, all the components except the phenolic curing agent are added to toluene and stirred to dissolve, thereby preparing a varnish having a concentration of 20% by mass to 50% by mass.

When a phenolic curing agent is used, a phenolic curing agent solution having a concentration of 50% by mass is prepared using methyl ethyl ketone (special grade product manufactured by Wako Pure Chemical Industries, Ltd.) as a solvent, and the solution is added to a varnish containing components other than the above-mentioned phenolic curing agent and stirred to prepare a varnish.

The varnish was applied onto a release-treated KAPTON film at a rate of 30 mm/sec, and then dried at 100°C for 30 minutes using a blower dryer under a nitrogen stream to obtain a film.

The obtained film was subjected to a curing reaction at 200° C. for 90 minutes using a blower dryer under a nitrogen stream to obtain a cured film.

The cured product film was supplied to the evaluation sample.

(Examples 44 to 55), (Comparative Examples 41 to 55)

In addition to the above components, the following components were used to prepare a resin composition according to the following preparation method.

<Component (III): Polar Resin>

[Polyimide resin]

Bis(3-ethyl-5-methyl-4-maleimidophenyl)methane (BMI-70) (manufactured by KI Chemicals Co., Ltd.)

4,4'-Bismaleimide diphenylmethane (BMI-H) (manufactured by KI Chemicals Co., Ltd.)

<Component (IV): Curing Agent>

Cyanate ester curing agent 2,2-bis(4-cyanatephenyl)propane (manufactured by Tokyo Chemical Industry Co., Ltd.)

Diamine curing agent 4,4'-diaminodiphenylmethane (manufactured by Tokyo Chemical Industry Co., Ltd.)

The component ratios and physical properties are shown in Tables 10 and 11 below.

First, a polyimide resin as a polar resin and a cyanate curing agent and/or a diamine curing agent as a curing agent were dissolved at 160° C. according to the mixing ratios shown in Tables 10 to 11 below, and reacted for 6 hours under stirring to obtain a bismaleimide triazine resin oligomer.

The obtained bismaleimide triazine resin oligomer was dissolved in toluene, and the remaining components were added and stirred to dissolve, thereby preparing a varnish having a concentration of 20% by mass to 50% by mass.

The varnish was applied onto a release-treated KAPTON film at a speed of 30 mm/sec, and then dried at 100°C for 30 minutes in a nitrogen stream using a blower dryer to obtain a film.

The film was subjected to a curing reaction at 200° C. for a maximum of 90 minutes using a blower dryer under a nitrogen stream to obtain a cured film.

The cured product film was supplied to the evaluation sample.

It is clear from Examples 28 to 55 and Comparative Examples 19 to 55 that the cured products of the resin compositions using the block copolymers of the present invention are excellent in the balance among dielectric properties, strength, and heat resistance.

As described above, it is clear that the cured product of the resin composition containing the block copolymer of the present invention is suitable for glass cloth applications and printed wiring board applications using a metal laminate.

Industrial Applicability

The block copolymer of the present invention, the resin composition comprising the block copolymer, and the cured product thereof have industrial applicability as materials for films, prepregs, electronic circuit boards, and next-generation communication boards.

Claims (12)

1. A block copolymer having:

a polymer block (A) mainly composed of vinyl aromatic monomer units; and

a polymer block (B) mainly composed of conjugated diene monomer units and/or a polymer block (C) composed of vinyl aromatic monomer units and conjugated diene monomer units,

The block copolymer satisfies the following conditions (i) to (ii),

< condition (i) >

The weight average molecular weight of the block copolymer is 3.5 ten thousand or less;

< condition (ii) >

The content of the vinyl aromatic monomer unit in the block copolymer is 55 to 95 mass%.

2. The block copolymer of claim 1, which further satisfies the following condition (iii),

< condition (iii) >

The polymer block (B) and/or the polymer block (C) contains a unit (a) derived from 1, 2-bonding and/or 3, 4-bonding and a unit (B) derived from 1, 4-bonding, and the content of the unit (a) derived from 1, 2-bonding and/or 3, 4-bonding is 80% or less, with the total content of the polymer block (B) and/or the polymer block (C) set to 100%.

3. A resin composition comprising:

component (I): the block copolymer of claim 1 or 2; and

at least one component selected from the group consisting of the following components (II) to (IV),

component (II): a free radical initiator;

component (III): a polar resin excluding the component (I);

component (IV): curing agent, excluding component (II).

4. The resin composition according to claim 3, wherein the component (III) is at least one selected from the group consisting of an epoxy resin, a polyimide resin, a polyphenylene ether resin, a liquid crystal polyester resin and a fluorine resin.

5. A cured product comprising the block copolymer according to claim 1 or 2.

6. A cured product of the resin composition according to claim 3.

7. A resin film comprising the resin composition according to claim 3.

8. A prepreg which is a composite of a substrate and the resin composition according to claim 3.

9. The prepreg of claim 8 wherein the substrate is glass cloth.

10. A laminate comprising the resin film according to claim 7 and a metal foil.

11. A laminate comprising a cured product of the prepreg according to claim 8 and a metal foil.

12. A material for an electronic circuit board, comprising the cured product according to claim 6.