CN118613516A - Block copolymer, resin composition, cured product, resin film, prepreg, laminate, and material for electronic circuit board - Google Patents

Abstract

The present invention provides a block copolymer, which has: a polymer block (C) composed of a vinyl aromatic monomer unit and a conjugated diene monomer unit; and a polymer block (A) mainly composed of a vinyl aromatic monomer unit and/or a polymer block (B) mainly composed of a conjugated diene monomer unit, and the block copolymer satisfies conditions (i) to (iv). <Condition (i)> The mass ratio in the above-mentioned polymer block (C) is vinyl aromatic monomer unit/conjugated diene monomer unit = 5/95 to 95/5. <Condition (ii)> The content of the above-mentioned polymer block (C) is 5 to 95 parts by mass relative to 100 parts by mass of the block copolymer. <Condition (iii)> Mw is 35,000 or less. <Condition (iv)> The content of the vinyl aromatic monomer unit is 5 to 95 parts by mass relative to 100 parts by mass of the block copolymer.

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 needs, materials with low dielectric loss are being sought in various substrate materials such as printed circuit boards and flexible circuit boards.

Conventionally, in order to obtain materials with low dielectric loss, research and publication have been conducted on cured resins having as main components thermosetting resins such as epoxy resins and thermoplastic resins such as polyphenylene ether resins that have low dielectric constants and/or low dielectric loss tangents and excellent mechanical properties such as strength.

However, the materials disclosed in the past still have room for improvement in terms of low dielectric constant and low dielectric loss tangent, and when they are used in printed circuit boards, there is a problem that the amount of information and the processing speed are limited.

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

For example, Patent Document 1 discloses, as a modifier for achieving low dielectric loss tangent and low dielectric constant of polyphenylene ether resin, at least one elastomer selected from the group consisting of block copolymers of vinyl aromatic compounds and olefin-based 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 still have insufficient dielectric constant reduction and dielectric loss tangent reduction, and have problems such as the strength of the resin composition being reduced due to the addition of these modifiers, and insufficient strength being obtained.

Therefore, an object of the present invention is to provide a block copolymer having a low dielectric constant and a low dielectric loss tangent and having a cured product excellent in 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 (C) composed of vinyl aromatic monomer units and conjugated diene monomer units; and

The polymer block (A) mainly contains vinyl aromatic monomer units and/or the polymer block (B) mainly contains conjugated diene monomer units,

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

<Condition (i)>

The mass ratio of the vinyl aromatic monomer unit to the conjugated diene monomer unit in the polymer block (C) is vinyl aromatic monomer unit/conjugated diene monomer unit=5/95 to 95/5.

<Condition (ii)>

The content of the polymer block (C) is 5 parts by mass or more and 95 parts by mass or less relative to 100 parts by mass of the block copolymer.

<Condition (iii)>

The weight average molecular weight is 35,000 or less.

<Condition (iv)>

The content of the vinyl aromatic monomer unit is 5 parts by mass or more and 95 parts by mass or less based on 100 parts by mass of the block copolymer.

[2]

A resin composition comprising:

Component (I): the block copolymer described in [1] 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))

[3]

The resin composition as described in the above-mentioned [2], wherein

The resin composition contains the above-mentioned component (III),

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.

[4]

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

[5]

A cured product, which is a cured product of the resin composition described in [2] or [3] above.

[6]

A resin film comprising the resin composition described in [2] or [3] above.

[7]

A prepreg which is a composite of a substrate and the resin composition described in [2] or [3] above.

[8]

The prepreg as described in the above-mentioned [7], wherein the substrate is glass cloth.

[9]

A laminate comprising the resin film described in [6] above and a metal foil.

[10]

A laminate comprising a cured product of the prepreg according to [7] or [8] above, and a metal foil.

[11]

A material for an electronic circuit board, comprising the cured product described in [5] above.

Effects of the Invention

According to the present invention, there can be provided a block copolymer which can provide a cured product having a low dielectric constant and a low dielectric loss tangent and also excellent in 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 this embodiment has:

A polymer block (C) composed of a vinyl aromatic monomer unit and a conjugated diene monomer unit (hereinafter sometimes referred to as polymer block (C)); and

A polymer block (A) mainly composed of vinyl aromatic monomer units (hereinafter sometimes referred to as polymer block (A)) and/or a polymer block (B) mainly composed of conjugated diene monomer units (hereinafter sometimes referred to as polymer block (B)).

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

<Condition (i)>

The mass ratio of the vinyl aromatic monomer unit to the conjugated diene monomer unit in the polymer block (C) is vinyl aromatic compound/conjugated diene compound=5/95 to 95/5.

<Condition (ii)>

The content of the polymer block (C) is 5 parts by mass or more and 95 parts by mass or less relative to 100 parts by mass of the block copolymer.

<Condition (iii)>

The weight average molecular weight is 35,000 or less.

<Condition (iv)>

The content of the vinyl aromatic monomer unit is 5 parts by mass or more and 95 parts by mass or less based on 100 parts by mass of the block copolymer.

The block copolymer of this embodiment can provide a cured product having a low dielectric constant and a low dielectric loss tangent and also excellent in strength characteristics.

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

The conjugated diene compound is a diene having one 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 versatile and easily available, which is advantageous from the viewpoint of cost, and can be easily copolymerized with styrene which is a common vinyl aromatic compound described later.

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

The conjugated diene compound may be a compound obtained by utilizing biotechnology.

The vinyl aromatic monomer unit refers to a structural unit derived from a vinyl aromatic compound in a polymer block or a block copolymer produced by polymerizing the 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 substances may be used alone or in combination of two or more.

The polymer block (C) constituting the block copolymer of the present embodiment is a polymer block composed of a vinyl aromatic monomer unit and a conjugated diene monomer unit, and no other monomer is intentionally added.

The vinyl aromatic compound and the conjugated diene compound used to form the vinyl aromatic monomer unit and the conjugated diene monomer unit contained in the polymer block (C) may be the above-mentioned vinyl aromatic compound and the conjugated diene compound.

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 in the polymer block (C) may be uniformly distributed or tapered. In addition, there may be a plurality of uniformly distributed portions and/or tapered distributed portions of the vinyl aromatic monomer units, respectively, or there may be a plurality of segments having different contents of the vinyl aromatic monomer units.

The polymer block (A) constituting the block copolymer mainly comprises vinyl aromatic monomer units. The term "mainly" means that the polymer block (A) is substantially composed of vinyl aromatic monomer units without intentionally adding other monomers.

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

When the block copolymer of the present embodiment contains the polymer block (A), the content of the polymer block (A) in the block copolymer 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 a sample.

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.

The block copolymer of the present embodiment contains a polymer block (C).

The polymer block (C) is composed of vinyl aromatic monomer units and conjugated diene monomer units.

The content of the polymer block (C) in the block copolymer of the present embodiment can be measured by an NMR method.

The polymer block (C) has a structure that specifically includes a vinyl aromatic monomer unit and a conjugated diene monomer unit as structural units, and can be distinguished from the polymer block (A) and the polymer block (B) described above.

<Condition (i)>

The mass ratio of the vinyl aromatic monomer unit to the conjugated diene monomer unit in the polymer block (C) is vinyl aromatic monomer unit/conjugated diene monomer unit=5/95 to 95/5.

As described below, the resin composition of the present embodiment includes the block copolymer of the present embodiment (component (I)) and at least one component selected from the group consisting of component (II): a radical initiator, component (III): a polar resin, and component (IV): a curing agent described later.

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

From the aspect of solubility parameter, compared with conjugated diene compound, the compatibility of vinyl aromatic compound with component (II), component (III) and component (IV) tends to be higher, but in the block copolymer of the present embodiment, by copolymerizing with conjugated diene compound, compared with the block polymer consisting of only vinyl aromatic compound, steric hindrance is reduced. As a result, by the presence of polymer block (C) (which is a random block of a polymer as a vinyl aromatic compound and a conjugated diene compound) in the block copolymer, the compatibility with component (III) and component (IV) is further improved, and the strength of the resin composition and/cured product of the present embodiment described later is improved.

In addition, the conjugated diene compound has free radical reactivity. As mentioned above, the compatibility of polymer block (C) with component (II), component (III) and component (IV) is excellent, so the conjugated diene monomer unit contained in polymer block (C) is present in a position close to component (II), component (III) and component (IV), and becomes a state that easily causes the reaction of the conjugated diene monomer unit with these components. Even if the resin composition of the present embodiment described later does not include one or two components in component (II), component (III) and component (IV), since the vinyl aromatic monomer unit in the block copolymer of the present embodiment is non-crystalline, it also has a tendency of high reactivity of the conjugated diene monomer unit between each molecular chain of different block copolymers.

In addition, by improving the above-mentioned compatibility, the resin composition and cured product of the present embodiment described later can suppress the reduction of the mobility and polarization of the polymer caused by the external electric field, and the resin composition and cured product have a tendency to realize low dielectric loss tangent and low dielectric constant. The loss (dielectric constant) caused by the polarization of the polymer due to the external electric field and the energy loss (dielectric loss tangent) of heat generated by movement can be suppressed by fully ensuring the compatibility and reactivity with the components (III) and (IV) described later, so when the block copolymer of the present embodiment has at least one polymer block (C), the strength of the resin composition and cured product of the present embodiment can be improved, and it is low dielectric loss tangent and low dielectric constant.

From the above viewpoints, the mass ratio of the vinyl aromatic monomer unit to the conjugated diene monomer unit in the polymer block (C) is vinyl aromatic monomer unit/conjugated diene monomer unit=5/95 to 95/5, preferably 10/90 to 90/10, more preferably 15/85 to 85/15, and even more preferably 20/80 to 80/20.

By making the amount of the vinyl aromatic monomer unit in the polymer block (C) 5% by mass or more, sufficient compatibility is exhibited in the resin composition for electronic materials, and by making the content 95% by mass or less, reactivity can be ensured. By making the amount of the conjugated diene monomer unit in the polymer block (C) 5% by mass or more, reactivity is good, and by making the content 95% by mass or less, good compatibility is exhibited, sufficient strength is obtained, and the resin composition and the cured product tend to achieve low dielectric loss tangent and low dielectric constant.

<Condition (ii)>

As described above, from the aspect of obtaining a resin composition and a cured product showing sufficient compatibility and having sufficient strength, having a low dielectric loss tangent and a low dielectric constant, relative to 100 parts by mass of a block copolymer, the content of the polymer block (C) in the block copolymer of the present embodiment is 5 parts by mass or more and 95 parts by mass or less. In addition, relative to 100 parts by mass of a block copolymer of the present embodiment, the content of polymer block (A) and/or polymer block (B) is preferably 5 parts by mass or more and 95 parts by mass or less.

The content of the polymer block (C) in the block copolymer of the present embodiment is preferably 10 to 90 parts by mass, more preferably 15 to 85 parts by mass, and even more preferably 20 to 80 parts by mass, based on 100 parts by mass of the block copolymer.

The content of the polymer block (A) and/or the polymer block (B) is more preferably 10 parts by mass to 90 parts by mass, further preferably 15 parts by mass to 85 parts by mass, and still more preferably 20 parts by mass to 80 parts by mass.

In addition, the block copolymer of the present embodiment preferably has at least one polymer block (B) from the aspect of the above-mentioned reactivity, and the content of the polymer block (B) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 15 parts by mass or more, relative to 100 parts by mass of the block copolymer of the present embodiment.

Furthermore, when the block copolymer of the present embodiment contains a polymer block (A), from the aspect of compatibility of the block copolymer with the component (III) and/or the component (IV), the content of the polymer block (A) is preferably 5 to 95 parts by mass, more preferably 10 to 90 parts by mass, further preferably 15 to 85 parts by mass, further more preferably 20 to 80 parts by mass, and further preferably 25 to 80 parts by mass, relative to 100 parts by mass of the block copolymer.

The block copolymer of the present embodiment has at least one polymer block (A) and/or polymer block (B). The block copolymer of the present embodiment preferably has at least one polymer block (B) at a terminal.

The polymer block (A) is a polymer block mainly composed of vinyl aromatic monomer units and is therefore amorphous. By including the polymer block (A) in the resin composition and cured product of the present embodiment described below, the entanglement strength between polymer chains is improved.

The polymer block (B) is a polymer block mainly composed of a conjugated diene monomer unit, and thus has free radical reactivity. In the resin composition and cured product of the present embodiment described later, each component (II) to (IV) constituting the resin composition reacts with the block copolymer, or the block copolymers react with each other, thereby improving the strength of the cured product.

In addition, from the improvement of compatibility caused by the above-mentioned vinyl aromatic compound and the strength improvement caused by the agglomeration of the polymer composed of the vinyl aromatic compound and the reactivity of the block copolymers caused by the conjugated diene compound, and then from the reactivity of the block copolymer with component (II), component (III) and component (IV), the content of the vinyl aromatic monomer unit and the conjugated diene monomer unit in the block copolymer of the present embodiment is preferably 5 parts by mass or more relative to 100 parts by mass of the block copolymer. By making the content of the vinyl aromatic monomer unit and the conjugated diene monomer unit 5 parts by mass or more in 100 parts by mass of the block copolymer, the compatibility of the block copolymer and other components can be maintained in the resin composition for electronic materials, the strength due to the agglomeration of the vinyl aromatic monomer unit can be ensured and sufficient reactivity can be ensured, and the resin composition and the cured product tend to show sufficient strength.

In addition, from the perspective of strength, low dielectric loss tangent, and low dielectric constant of the resin composition and cured product, the upper limit of the content of the vinyl aromatic monomer unit and the conjugated diene monomer unit is preferably 95 parts by mass or less relative to 100 parts by mass of the block copolymer of this embodiment.

In the block copolymer of the present embodiment, other monomers copolymerizable with the above-mentioned vinyl aromatic compound and/or the above-mentioned conjugated diene compound can be copolymerized within the range that does not impair the desired dielectric properties, i.e., the desired low dielectric loss tangent and low dielectric constant. The polymer block formed by the above-mentioned other monomers is used as polymer block (D).

The content of the polymer block (D) is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, further preferably 10 parts by mass or less, further more preferably 5 parts by mass or less, and further preferably 0 parts by mass, relative to 100 parts by mass of the block copolymer of the present embodiment. That is, it is preferred not to intentionally add monomers other than the vinyl aromatic compound and the conjugated diene compound.

<Condition (iii)>

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

Regarding the above-mentioned weight average molecular weight, the peak molecular weight of the chromatogram obtained by measurement based on gel permeation chromatography (GPC) is obtained based on a calibration curve obtained by measurement of commercially available standard polystyrene (prepared using the peak molecular weight of standard polystyrene). The obtained peak molecular weight is the weight average molecular weight (Mn), which can be specifically measured by the method described in the examples described later.

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

From the perspective of preventing deterioration in handling properties caused by a sharp drop in viscosity due to the mixing of low molecular weight polymers (specifically, polymers with a weight average molecular weight of 500 or less), the molecular weight distribution of a single peak of the block copolymer of this embodiment measured by GPC is preferably 5.0 or less, more preferably 4.0 or less, further preferably 3.0 or less, and further more preferably 2.5 or less.

By making the weight average molecular weight of the block copolymer of the present embodiment less than 35,000, the crosslinking property is improved, a uniform mesh structure is formed, and a high-strength cured product is obtained. In addition, the compatibility with the components (III) and (IV) described later is improved, and a low dielectric constant and a low dielectric loss tangent are tended to be achieved.

In addition, when the resin composition of the present embodiment is used to form a prepreg, when the varnish described later is impregnated into a substrate such as glass cloth described later, by making the weight average molecular weight of the block copolymer of the present embodiment less than 35,000, the block copolymers are uniformly cross-linked with each other and are uniformly compatible with component (III): polar resin, thereby improving the strength of the cured product containing the block copolymer, and having a tendency to achieve low dielectric loss tangent and low dielectric constant.

In addition, in the prepreg using the resin composition of the present embodiment, good permeability into the base material can be obtained, a uniform prepreg can be produced, the strength can be improved, and there is a tendency to achieve a low dielectric loss tangent and a low dielectric constant.

From the above aspects, the weight average molecular weight of the block copolymer of the present embodiment is 35,000 or less, preferably 30,000 or less, more preferably 25,000 or less, further preferably 20,000 or less, and further more preferably 25,000 or less. The lower limit of the weight average molecular weight of the block copolymer is not particularly limited, but is preferably 500 or more from the perspective of suppressing the stickiness of the block copolymer and obtaining good handling properties.

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 (iv)>

In the block copolymer of the present embodiment, the content of the vinyl aromatic monomer unit is 5 parts by mass or more and 95 parts by mass or less based on 100 parts by mass of the block copolymer.

By making the content of the vinyl aromatic monomer unit 5 parts by mass or more, from the aspect of solubility parameter, the compatibility with the component (II), component (III), and component (IV) described later can be improved, the strength of the resin composition and the cured product of the present embodiment is improved, and there is a tendency to achieve low dielectric loss tangent and low dielectric constant. From the aspect of solubility parameter, the content of the vinyl aromatic monomer unit is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, further preferably 20 parts by mass or more, and further more preferably 25 parts by mass or more.

By making the content of the vinyl aromatic monomer unit 95 parts by mass or less, the reactivity of the block copolymer of the present embodiment with the component (II), component (III) and component (IV) described later, and the reactivity of the block copolymer of the present embodiment with each other can be ensured. The content of the vinyl aromatic monomer unit is preferably 90 parts by mass or less, more preferably 85 parts by mass or less, and further preferably 80 parts by mass or less.

The content of the vinyl aromatic monomer unit in the block copolymer of the present embodiment can be measured by NMR, and specifically, can be measured by the method described in Examples below.

The content of the vinyl aromatic monomer unit in the block copolymer of the present embodiment can be controlled within the above-mentioned numerical range by adjusting the amount of monomer added in the polymerization step.

In the block copolymer of the present embodiment, the conjugated diene monomer units in the polymer block (B) and the polymer block (C) include units (a) derived from 1,2-bonds and/or 3,4-bonds (hereinafter sometimes referred to as units (a)) and units (b) derived from 1,4-bonds (hereinafter sometimes referred to as units (b)). When the total content of the conjugated diene monomer units in the polymer block (B) and the polymer block (C) is 100%, from the perspective of the reactivity of the block copolymers during curing in the process of obtaining a cured product and the reactivity with the components (III) and (IV) described later, the content of the units (a) derived from 1,2-bonds and/or 3,4-bonds is preferably 10 to 95%, more preferably 15 to 90%, further preferably 20 to 85%, and further more preferably 25 to 80% or less.

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

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

Examples of the adjuster 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 the tertiary amine compound 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-dipiperidylethane, trimethylaminoethylpiperazine, N,N,N',N",N"-pentamethylethylenetriamine, and N,N'-dioctyl-p-phenylenediamine.

The amount of the adjusting agent added is preferably 0.1 mol or more, more preferably 0.5 mol or more, and further preferably 1.0 mol or more relative to 1 mol of the polymerization initiator described below. In addition, when the above-mentioned unit (a) is 80% or more, the amount of the adjusting agent added is preferably 0.15 mol or more, more preferably 0.5 mol or more, and further preferably 1.0 mol or more relative to 1 mol of the polymerization initiator described below.

The block copolymer of the present embodiment may include a 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.

There is no particular limitation on the method for hydrogenating the block copolymer, and a conventionally known method can be applied.

A hydrogenation catalyst may be used in the above hydrogenation reaction.

As hydrogenation catalysts, for example, the following can be used: (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 in which 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 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. In the cyclopentadienyl titanium compound, the above skeletons may include one alone or two in combination.

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 of the present embodiment 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 further preferably 65 ° C to 160 ° C. In addition, the pressure of hydrogen used in the hydrogenation reaction is usually 0.1 to 15 MPa, 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 when 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 curing reactivity and thermal stability. When the curing reaction when obtaining the cured product is a reaction 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 for 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. 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 groups such as 1-(tert-butyldimethylsilyloxy)hexyl lithium disclosed in British Patent No. 2,241,239, alkyl lithium containing amino groups disclosed in U.S. Patent No. 5,527,753, lithium diisopropylamine, and lithium amides such as lithium hexamethyldisilazide can also be used.

As for the method of polymerizing the vinyl aromatic compound and the 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 particular, batch polymerization is suitable for obtaining uniform polymer blocks.

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 to a pressure range that can maintain the monomer and the solvent in the liquid phase within the above-mentioned temperature range. In addition, it is necessary to be careful not to mix impurities such as water, oxygen, carbon dioxide, etc. that deactivate the catalyst and the active polymer into the polymerization system.

In addition, at the end of the above-mentioned polymerization step, a necessary amount of a bifunctional or higher-functional coupling agent can be added within the range satisfying the above-mentioned conditions (i) to (iv) to carry out a coupling reaction, and 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, conventionally known ones 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 multifunctional coupling agent, conventionally known coupling agents 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 _R4 - _nSiXn (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 _R4 - _nSnXn (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 solution of the block copolymer 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 a metal atom in the hydrogenation catalyst in the above-mentioned hydrogenation reaction, reacts with moisture in the air in the desolvation process, etc., to generate a predetermined metal compound, which tends to remain in the block copolymer. If these metal compounds are contained in the cured product formed using the conjugated diene polymer of this embodiment, there is a tendency to increase the dielectric constant and the dielectric loss tangent, 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 metal compounds contained in polymerization initiators and hydrogenation catalysts, for example, oxides containing atoms of titanium oxide, amorphous titanium oxide, orthotitanic acid, metatitanic acid, titanium hydroxide, nickel hydroxide, nickel monoxide, lithium oxide, lithium hydroxide, cobalt oxide, cobalt hydroxide, and composite oxides of atoms and heterogeneous metals such as lithium titanate, barium titanate, strontium titanate, nickel titanate, and nickel-iron oxide.

From the aspect of realizing low dielectric constant, low dielectric loss tangent, and not being easy to produce ion migration in the resin composition and cured product of the present embodiment, 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 residual metal, Ti, Ni, Li, Co, etc. can be usually 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, it can be cited as follows: a method of adding water and carbon dioxide after the hydrogenation reaction of the block copolymer to neutralize the hydrogenation catalyst residue; a method of adding an acid in addition to water and carbon dioxide to neutralize the hydrogenation catalyst residue. Specifically, the method described in Japanese Patent Application No. 2014-557427 can be applied. Even if these metal removal methods are used, water containing a hydroxide of a metal compound is mixed in the desolventizing process of the block copolymer, so the amount of residual metal is usually about 1 to 15 ppm. Thus, relative to the amount of metal added to the block copolymer, it is preferably removed by more than 20%, more preferably by more than 30%, further preferably by more than 40%, further more preferably by more than 50%, and further preferably by more than 60%.

In addition, by reducing the amount of the 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 the polymerization initiator is reduced, the molecular weight of the block copolymer increases, and if it is outside the above-mentioned preferred molecular weight range, the strength of the cured product tends to decrease. In addition, when the hydrogenation reaction is carried out, if the amount of the hydrogenation catalyst is reduced, the hydrogenation reaction time will be prolonged and the hydrogenation reaction temperature will be increased, and there is a tendency that the productivity is significantly reduced.

As the method for separating the solvent when taking out the block copolymer, for example, there can be mentioned: a method of adding a polar solvent such as acetone or alcohol, which is a poor solvent for the block copolymer, to the reaction liquid after hydrogenation to precipitate the block copolymer and recover it; a method of putting the reaction liquid into hot water under stirring, removing the solvent by steam stripping and recovering it; 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 low dielectric loss tangent and the low dielectric constant.

The “polar group” includes, but is 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" in the block copolymer of the present embodiment, a known method can be applied, and there is no particular limitation.

For example, there can be mentioned a melt kneading method, a method of dissolving or dispersing and mixing the components in a solvent, etc. for reaction, etc. In addition, there can be mentioned the following methods: a method of polymerization by anionic living polymerization using a polymerization initiator having a functional group and an unsaturated monomer having a functional group; a method of modification by addition reaction of a modifier having a functional group formed or containing a functional group at the active end; a method of reacting an organic alkali metal compound such as an organic lithium compound with a block copolymer (metallization reaction) to allow an addition reaction of a modifier having a functional group and a block polymer to which an organic alkali metal has been added, etc.

[Resin composition]

The resin composition of the present embodiment contains the block copolymer of the present embodiment (component (I)) 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 block copolymer and component (II): a radical initiator.

(Component (II): free radical initiator)

As the radical initiator, a conventionally known one can be used.

For example, the thermal radical initiator includes hydroperoxides such as diisopropylbenzene hydroperoxide (Percumyl P), cumene hydroperoxide (Percumyl H), and tert-butyl hydroperoxide (Perbutyl H); dialkyl peroxides such as α,α-bis(tert-butylperoxy-m-isopropyl)benzene (Perbutyl P), dicumyl peroxide (Percumyl D), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (PERHEXA 25B), tert-butylcumyl peroxide (Perbutyl C), di-tert-butyl peroxide (Perbutyl D), 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne (Perhexyne 25B), and tert-butyl peroxy(2-ethylhexanoate) (Perbutyl O); ketone peroxides; n-butyl-4,4-di(tert-butylperoxy)valerate (PERHEXA V) and other peroxide ketals; 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 initiators may be used alone or in combination of two or more.

(Component (III): polar resin)

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

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

Regarding the polar resin with free radical reactivity as component (III), for example, a polymer having at least one vinyl group in the polymer, a homopolymer of a compound containing a halogen element, and a copolymer thereof with any compound, etc. From the perspective of low dielectric loss tangent and low dielectric constant of the resin composition and cured product of the present embodiment, the polar resin as the above-mentioned component (III) is preferably a polymer having a vinyl group.

The polymer having a vinyl group may be a polymer composed of repeating units having a vinyl group, may be a polymer of a compound having a vinyl group and a compound having 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 the compound having a vinyl group and a polar group include, but are not limited to, 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; vinyl monomers containing sulfonic acid groups such as vinyl sulfonic acid, (meth)allyl sulfonic acid, methyl vinyl sulfonic acid, and styrene sulfonic acid; vinyl monomers containing hydroxyl groups such as hydroxystyrene, N-hydroxymethyl (meth)acrylamide, hydroxyethyl (meth)acrylate, and hydroxypropyl (meth)acrylate; vinyl monomers containing phosphate groups such as 2-hydroxyethyl (meth)acryloyl phosphate, phenyl-2-acryloyloxyethyl phosphate, and 2-acryloyloxyethylphosphonic acid; and vinyl monomers containing hydroxystyrene, N-hydroxymethyl (meth)acrylamide, hydroxyethyl (meth)acrylate, and hydroxypropyl (meth)acrylate. The present invention also includes vinyl monomers containing hydroxyl groups, such as olefins, N-hydroxymethyl (meth)acrylamide, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, 1-butene-3-ol, vinyl monomers containing amino groups, such as aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate, vinyl monomers containing amide groups, such as (meth)acrylamide, N-methyl (meth)acrylamide, and N-butylacrylamide, vinyl monomers containing nitrile groups, such as (meth)acrylonitrile, cyanostyrene, and cyanoacrylate, and vinyl monomers containing epoxy groups, such as glycidyl methacrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenylphenyl oxide.

Examples of the compound containing a halogen element include, but are not limited to, 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.

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

From the viewpoint of curing reactivity, the curing agent as component (IV) preferably has two or more polar groups that can react 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 group 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; and so on.

Whether these polar groups are bonded to 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 the reaction can proceed 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) is converted into 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 molar ratio of component (III): polar resin and component (IV): curing agent is preferably polar group of component (III): polar group of 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 polar groups.

Regarding component (IV): curing agent, examples of curing agents having an ester group include but are not limited to EXB9451, EXB9460, EXB, 9460S, HPC8000-65T, HPC8000H-65TM, EXB8000L-65TM, EXB8150-65T, EXB9416-70BK manufactured by DIC Corporation and YLH1026, DC808, YLH1026, YLH1030, and YLH1048 manufactured by Mitsubishi Chemical Corporation.

Examples of curing agents having a hydroxyl group include, but are not limited to, 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, and the like.

Examples of the curing agent having a benzoxazine group include, but are not limited to, ODA-BOZ manufactured by JFE Chemical Co., Ltd., HFB2006M manufactured by Showa High Molecular Co., Ltd., and P-d and F-a manufactured by Shikoku Chemical Industry Co., Ltd.

Examples of curing agents having an isocyanate group include, but are not limited to, 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 obtained by partially triazinizing these cyanate resins; 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, but are not limited to, V-03 and V-07 manufactured by Nisshinbo Chemical Co., Ltd.

Examples of curing agents having an amino group include, but are not limited to, 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-aminobenzidine), 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 or a secondary amine, and more preferably a primary amine.

Examples of curing agents having an acid anhydride group include, but are not limited to, 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, Polymer-type acid anhydrides such as pyromellitic 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, 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, but are not limited to, 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 the above-mentioned 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 polyimide resin, as long as there is an imide bond in the repeating unit, it belongs to the category of being called polyimide resin. For example, a common polyimide structure obtained by polycondensation (imide bonding) of tetracarboxylic acid or its dianhydride with diamine 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 a 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 but not limited to.

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.

Examples of the diamine include, but are not limited to, 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 of the resin composition and cured product of this embodiment, at least one of the above-mentioned tetracarboxylic acid or its dianhydride or diamine may have one or more functional groups selected from the group consisting of fluorine, trifluoromethyl, hydroxyl, sulfone, carbonyl, heterocycle, long-chain alkyl and allyl.

As the polyimide resin, commercially available polyimide resins may be used, and examples thereof include, but are not limited to, 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 Co., Ltd., trade name) (the varnish of these polyimide resins may contain silicon oxide), Rikacoat SN20 manufactured by Shin Nippon Rika Co., Ltd., and Rikacoat SN2500 manufactured by Shin Nippon Rika Co., 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 in addition to the phenylene ether unit.

As a homopolymer having a phenylene ether unit, there is no particular restriction on whether the phenylene in the phenylene unit has a substituent. As the substituent, for example, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, acryloyl, 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-vinylphenyl Substituents containing unsaturated bonds such as vinyl, o-vinylphenylpropenyl, o-vinylphenylbutenyl, methacryloyl, acryloyl, 2-ethylacryloyl, 2-hydroxymethacryloyl, hydroxyl, carboxyl, carbonyl, thiocarbonyl, acyl halide, anhydride, carboxylic acid, thiocarboxylic acid, aldehyde, thialdehyde, carboxylate, amide, sulfonic acid, sulfonate, phosphoric acid, phosphoric acid, amino, imino, nitrile, pyridyl, quinolyl, epoxy, thioepoxy, thioether, isocyanate, isothiocyanate, halogenated silicon, silanol, alkoxysilyl, halogenated tin, boric acid, boron-containing, 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 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 belonging to component (III) is a polyester that forms an anisotropic melt phase, and any resin that falls within the category of liquid crystal polyester resins may be used. Examples include, but are not limited to, "X7G" manufactured by Eastman Kodak, Xyday manufactured by Dartco, EKONOL manufactured by Sumitomo Chemical, and Vectra manufactured by Celanese.

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, but are not limited to, polytetrafluoroethylene, perfluoroalkoxyalkane, ethylene-tetrafluoroethylene copolymer, perfluoroethylene-propylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, and ethylene-chlorotrifluoroethylene copolymer.

The epoxy resin as component (III) may be any resin that 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, but are not limited to, 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, tetraphenylethane-type epoxy resins, and the like.

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 curing agent as component (IV) 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, and 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), it is preferred to use component (II): a free radical initiator and component (IV): a curing agent in combination from the aspect of curability. 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), it is preferred to add the above-mentioned component (II): a free radical initiator and the above-mentioned component (IV): a curing agent from the aspect of curability.

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 include component (IV). As a high melting point and high rigidity resin belonging to component (III), for example, a liquid crystal polyester resin, a fluorine resin such as polytetrafluoroethylene can be cited.

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).

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

The curing accelerator is added for the purpose of promoting the reactivity between the above-mentioned components, and any known curing accelerator may be used, for example, phosphorus curing accelerators, amine curing accelerators, imidazole curing accelerators, guanidine curing accelerators, metal curing accelerators, etc. may be mentioned.

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, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, and the like, preferably triphenylphosphine and tetrabutylphosphonium decanoate.

Examples of the amine-based curing accelerator 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-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine ... Imidazole compounds such as amino-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 2,4-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 product may be used, and examples thereof include, but are not limited to, 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 organic metal complexes or organic metal salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin.

Examples of the organic metal complex include, but are not limited to, 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.

Examples of the organic metal salt include, but are not limited to, 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 fibers, glass beads, glass hollow spheres, glass flakes, graphite, titanium oxide, potassium titanate whiskers, carbon fibers, 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 shapes such as flaky, spherical, granular, powdery, or amorphous.

The resin composition or cured product of the present embodiment is often exposed to high temperature 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 preferred as the filler. As silicon oxide, for example, amorphous silicon oxide, fused silicon oxide, crystalline silicon oxide, synthetic silicon oxide, hollow silicon oxide, etc. can be cited.

Examples of the flame retardant include 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, and flame retardants of aromatic bromine compounds including hexabromobenzene, decabromodiphenylethane, 4,4-dibromobiphenyl, and ethylenebistetrabromophthalimide.

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

The flame retardants mentioned above also include so-called flame retardant auxiliary agents which have low flame retardancy-expressing effects by themselves but can synergistically exert more excellent effects 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 fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, and 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 generally used for mixing resin compositions and cured products.

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, phthalates, 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.

From the viewpoint of lowering the dielectric constant and dielectric loss tangent of the resin composition and cured product of the present embodiment, 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 soluble solvent and stirring (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 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, and the like.

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 any temperature and time. The cured product is a concept that only a portion of the resin composition is cured and contains uncured components (semi-cured) in addition to the completely cured mode. In the manufacturing process of the laminate described later, a process for further curing the cured product can be implemented. 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 more preferably 120°C or more. As the reaction time, it is preferably 10 to 240 minutes, more preferably 20 to 230 minutes, and more preferably 30 to 220 minutes. In the case where the resin composition of the present embodiment is a varnish, it is preferably dried to remove the solvent and then perform the curing reaction. As a drying method, it can be implemented by existing known methods such as heating and blowing hot air, preferably at a temperature lower than the curing reaction temperature, and the amount of solvent in the resin composition when the curing reaction is performed after the solvent is removed is preferably dried in a manner of less than 10% by mass, more preferably less than 5% by mass.

[Resin film]

The resin film of this embodiment contains the resin composition of this embodiment.

The resin film of the present embodiment is obtained by spreading a varnish composed of the resin composition of the present embodiment described above into a uniform thin film, drying it as described above to remove the solvent, and then winding it into a roll for storage.

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.

[Prepreg]

The prepreg of the present embodiment includes a substrate and the resin composition of the present embodiment impregnated or applied to the substrate. That is, the prepreg of the present embodiment is a composite of the resin composition of the present embodiment and the substrate.

The prepreg is obtained by, for example, impregnating a substrate such as glass cloth into a 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 various glass cloths such as roving, cloth, chopped mat, surface mat, 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; natural fiber cloths such as cotton cloth, linen, and felt; natural cellulose substrates such as carbon fiber cloth, kraft paper, cotton paper, and cloth obtained from paper-glass mixed yarn; polytetrafluoroethylene porous membranes, etc. From the aspects of low dielectric loss tangent and low dielectric constant, 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, there is a tendency that insulation reliability is more excellent when the prepreg is used for electronic substrate applications, etc. By making the above ratio 80% by mass or less, there is a tendency that mechanical properties such as rigidity are more excellent in applications such as electronic substrates.

[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, by undergoing the following steps: step (a), 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), heating and pressurizing the above-mentioned resin layer to flatten it to obtain a cured product of the prepreg; and step (c), further forming a specified wiring layer composed of metal foil on the above-mentioned resin layer; and the like.

In the above-mentioned step (a), the method of laminating the resin film on the substrate is not particularly limited, and for example, a method of laminating using a multi-stage press, a vacuum press, a normal pressure laminator, a laminator heated and pressed under vacuum, etc. can be cited, and a method of using a laminator heated and pressed under vacuum is preferred. By using the method using the laminator, even if the target electronic circuit substrate has a fine wiring circuit on the surface, the circuits can be buried with resin without generating pores. In addition, the lamination can be batch-type or continuous type using rollers, etc.

As the substrate of the laminate, in addition to the substrate constituting the prepreg, for example, glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, polyphenylene ether substrates, fluororesin substrates, etc. can also be cited. The surface of the laminated resin layer of the substrate can 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, preferably the temperature is 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 to further form a predetermined wiring layer composed of a metal foil on the produced resin layer. The formation method is not particularly limited, and existing well-known methods can be cited, for example, etching methods such as subtractive methods, semi-additive methods, etc. can be cited.

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 away with a reagent by subsequent development treatment, thereby forming a 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, a metal layer is then formed by electrolytic plating, and then the unnecessary electroless plating layer is removed using a reagent or the like to form a desired wiring layer.

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

[Metal-clad laminate]

The laminate in the present embodiment described above may be in a plate shape or may be a flexible laminate 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 can be suitably used as a material for an electronic circuit board.

Examples of the metal foil include aluminum foil and copper foil. Among these, 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 cured product may be processed into a laminate by laminating the metal foil on one or both sides of the cured product according to the application.

As a method for manufacturing the above-mentioned laminated board, for example, the following method can be cited: forming a prepreg composed of the resin composition of this embodiment and a substrate, stacking it with a metal foil, and then curing the resin composition to obtain a laminated board in which the cured prepreg and the metal foil are stacked.

One of the particularly preferred uses of the laminate is a printed wiring board. In the printed wiring board, it is preferred that at least a portion of the metal foil is removed from the metal-clad laminate.

The above-mentioned printed wiring board can be made by the method of pressurized heating molding using the prepreg of the above-mentioned present embodiment. As a substrate, the same substrate as the substrate described above for the prepreg can be used. The above-mentioned printed wiring 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 can 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 of the 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 substrate 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 prepreg as a composite of a substrate and the resin composition. The material for the electronic circuit substrate of the present embodiment can be used as a printed wiring board having a metal foil with 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.

In addition, the structure identification and the measurement method of the physical property of the block copolymer (component (I)) used in the following Examples and Comparative Examples are shown below.

[Methods for determining polymer structure and physical properties]

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

The content of the vinyl aromatic monomer unit in the block copolymer before hydrogenation 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.

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

It should be noted that, regarding the molecular weight in the case of having a plurality of peaks in the chromatogram, it is the average molecular weight obtained based on the molecular weight of each peak and the composition ratio of each peak (obtained from the area ratio of each peak in the chromatogram). In addition, 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)

Using the hydrogenated component (I): block copolymer, the hydrogenation rate of the double bonds of the conjugated diene monomer units was measured using a nuclear magnetic resonance apparatus (DPX-400 manufactured by BRUKER).

((5) Mass Ratio of Vinyl Aromatic Monomer Unit to Conjugated Diene Monomer Unit in Polymer Block (C))

Each time the vinyl aromatic compound (styrene) and conjugated diene compound (butadiene) constituting each polymer block are added to the reactor, the polymerization solution before addition is sampled. The sampled polymer solution is injected into a 100mL bottle sealed with 0.50mL of n-propylbenzene and about 20mL of toluene as an internal standard, and a sample for measurement is prepared. The sample for measurement is measured by a gas chromatograph (made by Shimadzu Corporation: GC-14B) equipped with a packed column loaded with apisone resin, and the residual monomer amount in the polymer solution is obtained according to the calibration curve of the butadiene monomer and the styrene monomer obtained in advance, and the polymerization rate of the butadiene monomer and the styrene monomer is confirmed to be 100%. Thus, the composition ratio of the vinyl aromatic monomer unit to the conjugated diene monomer unit in the polymer block (C) and the mass ratio of the added vinyl aromatic monomer to the conjugated diene monomer unit are the same value.

The polymerization rate of butadiene was measured at a fixed temperature of 90°C, and the polymerization rate of styrene was measured at a temperature increase of 90°C (maintained for 10 minutes) to 150°C (10°C/min).

The compositions of the polymer block (C) are shown in Tables 1 and 2. The sum of these is the content (parts by mass) of the polymer block (C) relative to 100 parts by mass of the block copolymer.

[Material for block copolymer and resin composition]

(Preparation of Hydrogenation Catalyst)

The hydrogenation catalyst used when producing the block copolymer in the Examples and Comparative Examples described below 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, and a n-hexane solution containing 200 mmol of trimethylaluminum was added while the mixture was fully stirred, 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.

Tables 1 and 2 show the structure and physical property values of each block copolymer.

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 containing 35 parts by mass of styrene (concentration: 20% by mass) was added.

Next, 0.45 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 0.8 mol of tetramethylethylenediamine (TMEDA) relative to 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 35 parts by mass of styrene and 30 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.

The block copolymer (1) obtained as described above had a styrene content of 70% 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 content: units (a)/conjugated diene monomer units in polymer block (C)) of 70%.

<Block copolymer (2)>

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 15 parts by mass of butadiene (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 10 minutes.

Next, a cyclohexane solution (concentration: 20% by mass) containing 70 parts by mass of styrene and 15 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.

The block copolymer (2) obtained as described above had a styrene content of 70% 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 content: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 70%.

<Block copolymer (3)>

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 10 parts by mass of butadiene 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 15 minutes.

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

Then, a cyclohexane solution (concentration: 20% by mass) containing 10 parts by mass of butadiene was added and polymerized for 15 minutes. Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer.

The block copolymer (3) obtained as described above had a styrene content of 70% 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 content: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 71%.

<Block copolymer (4)>

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 5 parts by mass of styrene (concentration: 20% by mass) was added.

Next, 0.65 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 0.8 mol of tetramethylethylenediamine (TMEDA) relative to 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 7 minutes.

Next, a cyclohexane solution (concentration: 20% by mass) containing 10 parts by mass of styrene and 90 parts by mass of butadiene was added, and polymerization was carried out at 70° C. for 40 minutes.

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

The block copolymer (4) obtained as described above had a styrene content of 10% 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 content: units (a)/conjugated diene monomer units in polymer block (C)) of 69%.

<Block copolymer (5)>

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 butadiene (concentration: 20% by mass) was added.

Next, 0.65 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 0.8 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 (concentration: 20% by mass) containing 35 parts by mass of styrene and 15 parts by mass of butadiene was added, and polymerization was carried out at 70° C. for 20 minutes.

Then, a cyclohexane solution containing 25 parts by mass of butadiene (concentration: 20% by mass) was added and polymerization was carried out for 15 minutes. Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer.

The block copolymer (5) obtained as described above had a styrene content of 35% 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 content: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) 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 containing 15 parts by mass of butadiene (concentration: 20% by mass) was added.

Next, 0.65 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 10 minutes.

Next, a cyclohexane solution (concentration: 20% by mass) containing 55 parts by mass of styrene and 15 parts by mass of butadiene was added, and polymerization was carried out at 70° C. for 30 minutes.

Then, a cyclohexane solution containing 15 parts by mass of butadiene (concentration: 20% by mass) was added and polymerization was carried out for 15 minutes. Methanol was then added to terminate the polymerization reaction, thereby obtaining a block copolymer.

The block copolymer (6) obtained as described above had a styrene content of 55% 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 content: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 70%.

<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 containing 5 parts by mass of butadiene (concentration: 20% by mass) was added.

Next, 0.65 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 0.8 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 90 parts by mass of styrene and 5 parts by mass of butadiene was added, and polymerization was carried out at 70° C. for 35 minutes.

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

The block copolymer (7) obtained as described above had a styrene content of 90% 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 content: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 70%.

<Block copolymer (8)>

A polymerization reaction was carried out in the same manner as in the block copolymer (3) except that 0.23 parts by mass of n-butyl lithium was added based on 100 parts by mass of all monomers.

The block copolymer (8) obtained as described above had a styrene content of 70% 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: unit (a)/(polymer block (B)+conjugated diene monomer units in polymer block (C))) of 70%.

<Block copolymer (9)>

A polymerization reaction was carried out in the same manner as in the block copolymer (3) except that 0.29 parts by mass of n-butyl lithium was added based on 100 parts by mass of all monomers.

The block copolymer (9) obtained as described above had a styrene content of 70% by mass, a weight average molecular weight of 2.5×10 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: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 70%.

<Block copolymer (10)>

A polymerization reaction was carried out in the same manner as in the block copolymer (3) except that 1.4 parts by mass of n-butyl lithium was added based on 100 parts by mass of all monomers.

The block copolymer (10) obtained as described above had a styrene content of 70% 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: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 70%.

<Block copolymer (11)>

A polymerization reaction was carried out in the same manner as in the block copolymer (3) except that 0.1 mol of TMEDA was added to 1 mol of n-butyllithium.

The block copolymer (11) obtained as described above had a styrene content of 70% 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 content: units (a)/polymer block (B)+conjugated diene monomer units in polymer block (C)) of 30%.

<Block copolymer (12)>

The polymerization reaction was carried out in the same manner as in the block copolymer (3) except that 2 mol of TMEDA was added to 1 mol of n-butyllithium, the polymerization temperature was set to 50°C, and the polymerization time of each block was extended by 10 minutes.

The block copolymer (12) obtained as described above had a styrene content of 70% by mass, a weight average molecular weight of 1.5×10 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: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 85%.

<Block copolymer (13)>

The polymerization reaction was carried out in the same manner as in the block copolymer (3). Using the obtained block copolymer, 50 ppm of the hydrogenation catalyst prepared above was added based on Ti per 100 parts by mass of the block copolymer, and a hydrogenation reaction was carried out for about 0.5 hours under the conditions of a hydrogen pressure of 0.7 MPa and a temperature of 80° C. to obtain a hydrogenated block copolymer (13).

The hydrogenated block copolymer (13) obtained as described above had a styrene content of 70% by mass, a weight average molecular weight of 1.5×10 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 amount: unit (a)/(polymer block (B)+conjugated diene monomer units in polymer block (C))) of 70%, and a hydrogenation rate of 50%.

<Block copolymer (14)>

The same operation as in the block copolymer (13) was carried out except that the hydrogenation reaction was carried out for about 0.25 hours.

The hydrogenated block copolymer (14) obtained as described above had a styrene content of 70% by mass, a weight average molecular weight of 1.5×10 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 amount: unit (a)/(polymer block (B)+conjugated diene monomer units in polymer block (C))) of 70%, and a hydrogenation rate of 22%.

<Block copolymer (15)>

The same operation as in the block copolymer (13) was carried out except that the hydrogenation reaction was carried out for about 0.75 hours.

The hydrogenated block copolymer (15) obtained as described above had a styrene content of 70% by mass, a weight average molecular weight of 1.5×10 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 amount: unit (a)/(polymer block (B)+conjugated diene monomer units in polymer block (C))) of 71%, and a hydrogenation rate of 69%.

<Block copolymer (16)>

A polymerization reaction was carried out in the same manner as in the block copolymer (1) except that 0.18 parts by mass of n-butyl lithium was added based on 100 parts by mass of all monomers.

The block copolymer (16) obtained as described above had a styrene content of 70% 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)/conjugated diene monomer units in polymer block (C)) of 71%.

<Block copolymer (17)>

A polymerization reaction was carried out in the same manner as in the block copolymer (2) except that 0.18 parts by mass of n-butyl lithium was added based on 100 parts by mass of all monomers.

The block copolymer (17) obtained as described above had a styrene content of 70% 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: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 70%.

<Block copolymer (18)>

A polymerization reaction was carried out in the same manner as in the block copolymer (3) except that 0.18 parts by mass of n-butyl lithium was added based on 100 parts by mass of all monomers.

The block copolymer (18) obtained as described above had a styrene content of 70% 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: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 71%.

<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 30 parts by mass of butadiene and 70 parts by mass of styrene was added.

Next, 0.65 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 0.8 mol of tetramethylethylenediamine (TMEDA) relative to 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 40 minutes.

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

The block copolymer (19) obtained as described above had a styrene content of 70% 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 content: units (a)/conjugated diene monomer units in polymer block (C)) of 70%.

<Block copolymer (20)>

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 15 parts by mass of styrene was added.

Next, 0.65 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 0.8 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 70 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 (concentration: 20% by mass) containing 15 parts by mass of styrene was added, and polymerization was carried out at 70° C. for 15 minutes.

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

The block copolymer (20) obtained as described above had a styrene content of 70% 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 content: units (a)/polymer block (B)) of 70%.

<Block copolymer (21)>

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 added.

Next, 0.65 parts by mass of n-butyl lithium relative to 100 parts by mass of all monomers and 0.8 mol of tetramethylethylenediamine (TMEDA) relative to 1 mol of n-butyl lithium were added, and polymerization was carried out at 70° C. for 30 minutes.

Next, a cyclohexane solution containing 70 parts by mass of butadiene (concentration: 20% by mass) 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.

The block copolymer (21) obtained as described above had a styrene content of 70% 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 content: units (a)/polymer block (B)) of 70%.

<Block copolymer (22)>

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 20 parts by mass of butadiene (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 15 minutes.

Next, a cyclohexane solution containing 60 parts by mass of styrene (concentration: 20% by mass) was added, and polymerization was carried out at 70° C. for 45 minutes.

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

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

The block copolymer (22) obtained as described above had a styrene content of 70% 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 content: unit (a)/(conjugated diene monomer units in polymer block (B)+polymer block (C))) of 69%.

<Block copolymer (23)>

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 10 parts by mass of butadiene was added.

Next, 0.28 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 10 minutes.

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

Next, a cyclohexane solution (concentration: 20% by mass) containing 20 parts by mass of styrene and 20 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.

The block copolymer (23) obtained as described above had a styrene content of 70% by mass, a weight average molecular weight of 2.6×10 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)+conjugated diene monomer units in polymer 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.

A 1.5-liter jacketed reactor equipped with a nozzle for introducing oxygen-containing gas, a stirring turbine blade and a guide plate at the bottom of the reactor and a reflux cooler at the exhaust line at the top of the reactor was used. 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 the reactor. The composition weight 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 circulated in the jacket to adjust the polymerization temperature so as to maintain 40°C. The polymerization liquid gradually presents a slurry state. When the polyphenylene ether reaches the desired number average molecular weight, stop the ventilation of the oxygen-containing gas and heat the obtained polymerization mixture to 50°C. Next, add hydroquinone (agent manufactured by Wako Pure Chemical Industries, Ltd.) in small portions, and continue to keep warm at 50°C until the slurry-like polyphenylene ether turns white. Next, add 720g of a methanol solution containing 6.5% by mass of 36% hydrochloric acid, filter, and further wash repeatedly with methanol to obtain wet polyphenylene ether. Next, vacuum dry at 100°C to obtain dry polyphenylene ether. ηsp/c is 0.103dl/g and the yield is 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.

152.5 g of polyphenylene ether and 152.5 g of toluene are mixed and heated to about 85°C. Next, 2.1 g of dimethylaminopyridine is added. When all the solids are dissolved, 18.28 g of methacrylic anhydride is slowly added. The obtained solution is continuously mixed while being maintained at 85°C for 3 hours. Next, the solution is cooled to room temperature to obtain a toluene solution of methacrylate-terminated polyphenylene ether. To the obtained toluene solution, 1000 mL of methanol at 10°C is added dropwise in small amounts in a cylindrical 3L SUS container equipped with a homogenizer for stirring. The obtained powder is filtered, washed with methanol, and dried 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.

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

Using the dielectric loss tangent and dielectric constant obtained above, the following examples and comparative examples were evaluated according to the following criteria.

<Evaluation Criteria in (Examples 1 to 18) and (Comparative Examples 1 to 8)>

Dielectric loss tangent

◎：0.0025 or less

○: 0.0030 or less

△: less than 0.0035

×: 0.0035 or more

Dielectric constant

◎：2.53 or less

○: 2.55 or less

△: less than 2.60

×: 2.60 or more

<Evaluation Criteria in (Examples 19 to 31) and (Comparative Examples 9 to 22)>

Evaluation was performed using the difference in dielectric loss tangent and dielectric constant between Comparative Example 9 not including a block copolymer and each of the Examples and Comparative Examples (Comparative Example 9 - each of the Examples or Comparative Examples).

Dielectric loss tangent

◎: 0.0012 or more

○: 0.0010 or more, less than 0.0012

△: 0.00080 or more, less than 0.0010

×: Less than 0.00080 (including equal values and positive differences)

Dielectric constant

◎: 0.12 or more

○: 0.10 or more, less than 0.12

△: 0.08 or more, less than 0.10

×: Less than 0.08 (including equal values and positive differences)

<Evaluation Criteria in (Examples 32 to 47) and (Comparative Examples 23 to 37)>

Evaluation was performed using the difference in dielectric loss tangent and dielectric constant between Comparative Example 23 not including a block copolymer and each Example or Comparative Example (Comparative Example 23-each Example or Comparative Example).

Dielectric loss tangent

◎: 0.010 or more

○: 0.008 or more, less than 0.010

△: 0.005 or more, less than 0.008

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

Dielectric constant

◎: 0.4 or more

○: 0.3 or more, less than 0.4

△: 0.2 or more, less than 0.3

×: less than 0.2 (including equal values and positive differences)

<Evaluation Criteria in (Examples 48 to 58) and (Comparative Examples 38 to 54)>

Evaluation was performed using the difference in dielectric loss tangent and dielectric constant between Comparative Example 38 not including a block copolymer and each Example or Comparative Example (Comparative Example 38-each Example or Comparative Example).

Dielectric loss tangent

◎: 0.0012 or more

○: 0.0010 or more, less than 0.0012

△: 0.00080 or more, less than 0.0010

×: Less than 0.00080 (including equal values and positive differences)

Dielectric constant

◎: 0.15 or more

○: 0.12 or more, less than 0.15

△: 0.10 or more, less than 0.12

×: less than 0.10 (including equal values and positive differences)

((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 reached a maximum was determined as the glass transition temperature (Tg).

A high Tg means 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 the measuring sample.

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

[Preparation of resin composition]

(Examples 1 to 31), (Comparative Examples 1 to 22)

Using the above components, 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 is added to toluene (special grade product manufactured by Wako Pure Chemical Industries, Ltd. is used as it is), stirred and dissolved, and a varnish having a concentration of 20% by mass to 50% by mass is prepared.

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 cured 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.

Examples 1 to 31 and Comparative Examples 1 to 22 show that the block copolymer of the present invention has an excellent balance between dielectric properties and strength when cured. The cured product of the present invention is particularly suitable for use as a printed wiring board using glass cloth or a metal laminate.

(Examples 32 to 47), (Comparative Examples 23 to 37)

In addition to the above components, the following components were further 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 and 8 below.

First, components other than the phenolic curing agent are added to toluene, stirred and dissolved, and a varnish having a concentration of 20% by mass to 50% by mass is prepared.

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

The varnish was applied on a release-treated KAPTON film at a rate 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 using a blower dryer under a nitrogen stream to obtain a cured film.

The cured product film was provided as an evaluation sample.

(Examples 48 to 58), (Comparative Examples 38 to 54)

In addition to the above components, the following components were further 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 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 9 and 10 below.

First, a polyimide resin as a polar resin and a cyanate curing agent and/or a diamine curing agent were dissolved at 160° C. according to the mixing ratios shown in Tables 9 and 10 below, and reacted for 6 hours under stirring to obtain a bismaleimide triazine resin oligomer.

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

The above varnish was applied on a release-treated KAPTON film at a speed of 30 mm/sec.

Thereafter, the resulting film was dried at 100° C. for 30 minutes using a blower dryer under a nitrogen stream 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 provided as an evaluation sample.

Examples 48 to 58 and Comparative Examples 38 to 54 show that the block copolymer of the present invention has an excellent balance between dielectric properties and strength when it is cured. It is found that the cured product of the present invention is suitable for use in printed wiring boards using glass cloth or metal laminates.

This application is based on the Japanese patent application (Japanese Patent Application No. 2022-033349) filed with the Japan Patent Office on March 4, 2022, and the international application (PCT/JP2023/000860) filed on January 13, 2023, and the contents thereof are incorporated into this specification by reference.

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 (11)

1. A block copolymer having:

a polymer block (C) composed of vinyl aromatic monomer units and conjugated diene monomer units; and

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

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

< Condition (i) >

The mass ratio of the vinyl aromatic monomer units to the conjugated diene monomer units of the polymer block (C) is vinyl aromatic monomer units/conjugated diene monomer units=5/95 to 95/5;

< condition (ii) >

The content of the polymer block (C) is 5 parts by mass or more and 95 parts by mass or less relative to 100 parts by mass of the block copolymer;

< condition (iii) >

The weight average molecular weight is below 3.5 ten thousand;

< condition (iv) >

The vinyl aromatic monomer unit content is 5 to 95 parts by mass based on 100 parts by mass of the block copolymer.

2. A resin composition comprising:

component (I): the block copolymer of claim 1; 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).

3. The resin composition according to claim 2, wherein,

The resin composition contains the component (III),

The component (III) is at least one selected from the group consisting of epoxy resins, polyimide-based resins, polyphenylene ether-based resins, liquid crystal polyester-based resins, and fluorine-based resins.

4. A cured product comprising the block copolymer according to claim 1.

5. A cured product of the resin composition according to claim 2 or 3.

6. A resin film comprising the resin composition according to claim 2 or 3.

7. A prepreg which is a composite of a substrate and the resin composition according to claim 2 or 3.

8. The prepreg of claim 7 wherein the substrate is a glass cloth.

9. A laminate comprising the resin film according to claim 6, and a metal foil.

10. A laminate comprising the cured product of the prepreg according to claim 7 and a metal foil.

11. A material for an electronic circuit board, comprising the cured product according to claim 5.