KR20240157733A - Resin composition, cured product, prepreg, metal foil-clad laminate, resin composite sheet, printed wiring board, and semiconductor device - Google Patents

Abstract

A resin composition having a low coefficient of thermal expansion (CTE) while maintaining excellent low-dielectric properties (Dk and/or Df), and providing a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device. The resin composition comprises a compound (M) represented by formula (M) and a polymer (V) having a structural unit represented by formula (V).

In formula (V), Ar represents an aromatic hydrocarbon linking group.

Description

Resin composition, cured product, prepreg, metal foil-clad laminate, resin composite sheet, printed wiring board, and semiconductor device

The present invention relates to a resin composition, a cured product, a prepreg, a metal foil-coated laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.

Recently, the integration and miniaturization of semiconductor devices used in electronic devices and communication devices, including mobile terminals, are accelerating. Along with this, technology that enables high-density mounting of semiconductor devices is being demanded, and improvements are also being demanded for printed wiring boards that occupy an important position.

Meanwhile, the use of electronic devices, etc. continues to diversify and expand. In response to this, the various characteristics required for printed wiring boards, metal foil-clad laminates, prepregs, etc. used therein are also diversifying and becoming more stringent. Taking such required characteristics into account, various materials and processing methods have been proposed to obtain improved printed wiring boards. One of them is the improvement and development of resin materials that constitute prepregs and resin composite sheets.

In addition, Patent Document 1 discloses a maleimide resin as shown below as a maleimide resin suitable for electronic material use. In addition, Patent Document 1 shows that a curable resin composition blended with an epoxy resin or the like has excellent dielectric properties. In addition, Patent Document 2 also describes the following compound.

[Chemical Formula 1]

International Publication No. 2020/054601 International Publication No. 2021/182360

As described above, the uses of electronic devices, etc. are diversifying and continuing to expand, and new materials are also required for resin materials constituting prepregs, etc. In particular, additional material development is required for resin compositions that maintain excellent low-dielectric properties (Dk and/or Df) while having a low coefficient of thermal expansion (CTE).

The present invention aims to solve the above problems, and provides a resin composition having a low coefficient of thermal expansion (CTE) while maintaining excellent low-dielectric properties (Dk and/or Df), and a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.

Under the above task, the inventor of the present invention conducted a study and found that the above task can be solved by using a predetermined maleimide compound and a predetermined polyfunctional vinyl aromatic polymer in combination.

Specifically, the above problem was solved by the following means.

＜1＞ A compound (M) represented by formula (M),

A resin composition comprising a polymer (V) having a structural unit represented by formula (V).

[Chemical formula 2]

(In formula (M), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom, each R ^mx independently represents a methylene group, an ethylidene group, or a 2,2-propylidene group, and R ^my is a group selected from the following group (A). m represents an integer of 0 to 3, and n is an average value of the repetition number and represents 1.00 ≤ n ≤ 20.00.)

(Army (A))

[Chemical Formula 3]

(In group (A), R ^y is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may have a substituent, ny is each independently an integer of 0 to 3, and * is a bonding position with R ^mx .)

[Chemical Formula 4]

(In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.)

＜2＞ A resin composition as described in ＜1＞, wherein the content of the compound (M) represented by the formula (M) is 1 to 90 parts by mass when the resin solid content in the resin composition is 100 parts by mass.

＜3＞ A resin composition according to ＜1＞ or ＜2＞, wherein the content of a polymer (V) having a structural unit represented by the formula (V) is 1 to 90 parts by mass when the resin solid content in the resin composition is 100 parts by mass.

＜4＞ A resin composition according to any one of ＜1＞ to ＜3＞, wherein in the compound (M) represented by the above formula (M), n is 1.05 ≤ n ≤ 20.00.

＜5＞ A resin composition according to any one of ＜1＞ to ＜4＞, wherein the compound (M) represented by the above formula (M) includes a compound represented by the formula (M-1).

[Chemical Formula 5]

(In formula (M-1), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with a halogen atom. m represents an integer of 0 to 3, and n represents the average value of the repetition number, 1.00 ≤ n ≤ 20.00.)

＜6＞ A resin composition according to any one of ＜1＞ to ＜4＞, wherein the compound (M) represented by the above formula (M) includes a compound represented by the formula (M-2).

[Chemical formula 6]

(In formula (M-2), R ^z each independently represents a hydrocarbon group having 1 to 10 carbon atoms. m represents an integer of 0 to 3, and n represents the average value of the repetition number, 1.00 ≤ n ≤ 20.00.)

＜7＞ A resin composition according to any one of ＜1＞ to ＜6＞, wherein the weight average molecular weight of the polymer (V) having a structural unit represented by the above formula (V) is 3,000 to 130,000.

＜8＞ A resin composition according to any one of ＜1＞ to ＜6＞, wherein the weight average molecular weight of the polymer (V) having a structural unit represented by the above formula (V) is 10,000 to 130,000.

＜9＞ In addition, a resin composition according to any one of ＜1＞ to ＜8＞, which comprises at least one other thermosetting compound (C) selected from the group consisting of a maleimide compound, an epoxy compound, a phenol compound, an oxetane resin, a benzoxazine compound, a compound containing a (meth)allyl group, and a polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds, other than a compound (M) represented by the above formula (M).

＜10＞ The resin composition described in ＜9＞, wherein the content of the other thermosetting compound (C) is 1 to 70 parts by mass when the resin solid content included in the resin composition is 100 parts by mass.

＜11＞ In addition, a resin composition according to any one of ＜1＞ to ＜10＞, which comprises a low-molecular-weight vinyl compound having a molecular weight of less than 1000 and containing one organic group including a carbon-carbon unsaturated bond in the molecule.

＜12＞ A resin composition according to ＜11＞, wherein the low-molecular-weight vinyl compound having a molecular weight of less than 1000 and containing one organic group containing a carbon-carbon unsaturated bond in the molecule comprises at least one selected from the group consisting of a (meth)acrylic acid ester compound, an aromatic vinyl compound, a saturated fatty acid vinyl compound, a vinyl cyanide compound, an ethylenically unsaturated carboxylic acid, an ethylenically unsaturated carboxylic anhydride, an ethylenically unsaturated dicarboxylic acid monoalkyl ester, and an ethylenically unsaturated carboxylic acid amide.

＜13＞ Additionally, a resin composition according to any one of ＜1＞ to ＜12＞, comprising a filler (D).

＜14＞ The resin composition described in ＜13＞, wherein the content of the filler (D) in the resin composition is 10 to 1600 parts by mass with respect to 100 parts by mass of the resin solid content.

＜15＞ Additionally, a resin composition according to any one of ＜1＞ to ＜14＞, comprising a thermoplastic elastomer.

＜16＞ When the resin solid content in the above resin composition is 100 parts by mass, the content of the compound (M) represented by the above formula (M) is 1 to 90 parts by mass,

When the resin solid content in the above resin composition is 100 parts by mass, the content of the polymer (V) having the structural unit represented by the above formula (V) is 1 to 90 parts by mass,

In the compound (M) represented by the above formula (M), n is 1.05 ≤ n ≤ 20.00,

The compound (M) represented by the above formula (M) includes a compound represented by the formula (M-1),

The weight average molecular weight of the polymer (V) having the structural unit represented by the above formula (V) is 3,000 to 130,000,

Additionally, a resin composition according to any one of <1> to <15>, comprising a thermoplastic elastomer.

[Chemical formula 7]

(In formula (M-1), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with a halogen atom. m represents an integer of 0 to 3, and n represents the average value of the repetition number, 1.00 ≤ n ≤ 20.00.)

＜17＞ A resin composition according to any one of ＜1＞ to ＜16＞, wherein the weight average molecular weight of the polymer (V) having a structural unit represented by the above formula (V) is 10,000 to 130,000.

＜18＞ A cured product of the resin composition described in any one of ＜1＞ to ＜17＞.

＜19＞ A prepreg formed from a resin composition described in any one of ＜1＞ to ＜17＞.

＜20＞ A metal foil-clad laminate comprising at least one layer formed of the prepreg described in ＜19＞, and a metal foil arranged on one or both sides of the layer formed of the prepreg.

＜21＞ A resin composite sheet comprising a support and a layer formed of a resin composition according to any one of ＜1＞ to ＜17＞ arranged on the surface of the support.

<22> A printed wiring board including an insulating layer and a conductor layer arranged on a surface of the insulating layer, wherein the insulating layer includes at least one of a layer formed from a resin composition as described in any one of <1> to <17> and a layer formed from a prepreg as described in <19>.

＜23＞ A semiconductor device including a printed wiring board described in ＜22＞.

According to the present invention, it has become possible to provide a resin composition having a low coefficient of thermal expansion (CTE) while maintaining excellent low-dielectric properties (Dk and/or Df), and a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.

Hereinafter, a form for implementing the present invention (hereinafter, simply referred to as “the present embodiment”) will be described in detail. In addition, the following present embodiment is an example for explaining the present invention, and the present invention is not limited to the present embodiment.

In addition, in this specification, “∼” is used to mean that the numerical values described before and after it are included as lower and upper limits.

In this specification, various physical property values and characteristic values are those at 23°C unless otherwise specified.

In the notation of a group (atomic group) in this specification, a notation that does not describe substitution and unsubstitution includes a group (atomic group) having a substituent as well as a group (atomic group) without a substituent. For example, "alkyl group" includes not only an alkyl group without a substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). In this specification, a notation that does not describe substitution and unsubstitution is preferably unsubstituted.

In this specification, the dielectric constant refers to the ratio of the dielectric constant of a substance to the dielectric constant of a vacuum. In addition, in this specification, the dielectric constant is sometimes simply referred to as "dielectric constant."

In this specification, "(meth)acryl" represents both, or either, of acrylic and methacrylic. "(meth)allyl" represents both, or either, of allyl and methacrylic.

If the standards indicated in this specification differ in measurement methods, etc. depending on the year, they shall be based on the standards as of January 1, 2022, unless otherwise specified.

In this specification, a maleimide group refers to a group represented by the following.

[Chemical formula 8]

(In the formula, each A independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. * indicates a bonding position with another site.)

A is preferably a hydrogen atom on both sides, at the point of preferably being hardened.

The number of carbon atoms in the alkyl group is preferably 1 to 3 from the viewpoint of desirable curing.

In this specification, the resin solid content refers to components excluding fillers and solvents, and is intended to include a compound (M) represented by formula (M), a polymer (V) having a structural unit represented by formula (V), and other thermosetting compounds (C) blended as necessary, and other resin additive components (additives such as flame retardants, etc.).

The resin composition of the present embodiment is characterized by including a compound (M) represented by formula (M) and a polymer (V) having a structural unit represented by formula (V).

[Chemical formula 9]

(In formula (M), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom, each R ^mx independently represents a methylene group, an ethylidene group, or a 2,2-propylidene group, and R ^my is a group selected from the following group (A). m represents an integer of 0 to 3, and n is an average value of the repetition number and represents 1.00 ≤ n ≤ 20.00.)

(Army (A))

[Chemical Formula 10]

(In group (A), R ^y is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may have a substituent, ny is each independently an integer of 0 to 3, and * is a bonding position with R ^mx .)

[Chemical Formula 11]

(In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.)

By forming it in this manner, a resin composition having a low coefficient of thermal expansion (CTE) is obtained while maintaining excellent low-dielectric properties (Dk and/or Df).

In the compound (M) represented by formula (M), since R ^mx is a methylene group, an ethylidene group, or a 2,2-propylidene group, and furthermore, since two R ^mx are bonded to one benzene ring, a compact structure is formed, so that even if a crosslinking reaction progresses, it is difficult to become rigid and it is easy to become compatible with other resin components. In particular, it is presumed that by combining the compound (M) represented by formula (M) and the polymer (V) having the structural unit represented by formula (V), a cured resin product having a strong network is formed, so that low dielectric properties (low dielectric constant, low dielectric tangent (particularly low dielectric tangent)) and a low coefficient of thermal expansion (low CTE) are achieved.

＜Compound (M) represented by formula (M)＞

The resin composition of the present embodiment contains a compound (M) represented by formula (M). By containing the compound (M) represented by formula (M), low dielectric properties (Dk and/or Df) of the obtained resin composition can be effectively achieved.

[Chemical Formula 12]

(In formula (M), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom, each R ^mx independently represents a methylene group, an ethylidene group, or a 2,2-propylidene group, and R ^my is a group selected from the following group (A). m represents an integer of 0 to 3, and n is an average value of the repetition number and represents 1.00 ≤ n ≤ 20.00.)

(Army (A))

[Chemical Formula 13]

(In group (A), R ^y is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may have a substituent, ny is each independently an integer of 0 to 3, and * is a bonding position with R ^mx .)

In formula (M), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom, and is preferably an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, or a phenyl group which may be substituted with a halogen atom, and is more preferably at least one selected from the group consisting of a methyl group, an ethyl group, a propyl group (preferably an isopropyl group), a butyl group (preferably a sec-butyl group, a tert-butyl group), and a phenyl group which may be substituted with a halogen atom. The halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and is more preferably a fluorine atom or a chlorine atom. In the present embodiment, R is preferably a hydrocarbon group having 1 to 10 carbon atoms which is not substituted with a halogen atom.

In formula (M), m represents an integer from 0 to 3, preferably an integer from 0 to 2, more preferably 0 or 1, and even more preferably 0.

In the formula (M), R ^mx is each independently a methylene group, an ethylidene group, or a 2,2-propylidene group. By using a methylene group, an ethylidene group, or a 2,2-propylidene group as R ^mx , it is presumed that, compared to an aromatic ring, it has low dielectric properties (Dk and/or Df), and also has a flexible structure, so that even if a crosslinking reaction progresses, it is difficult to become rigid and becomes easy to be compatible with other resin components. R ^mx is each independently preferably an ethylidene group or a 2,2-propylidene group, and is more preferably a 2,2-propylidene group.

In formula (M), R ^my is a group selected from group (A). In this way, by having a structure in which two adjacent R ^mx are bonded via one benzene ring, the structure does not become unnecessarily rigid and becomes easily compatible with other resin components.

In group (A), R ^y is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may have a substituent, and is preferably at least one selected from the group consisting of a methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, and a phenyl group.

ny is each independently an integer from 0 to 3, preferably an integer from 0 to 2, more preferably 0 or 1, and even more preferably 0.

In this embodiment, among group (A),

[Chemical Formula 14]

is desirable.

Also, in formula (M), n is the average of the number of repetitions and represents 1.00 ≤ n ≤ 20.00.

n is preferably 1.05 or more (1.05 ≤ n), more preferably 1.10 or more (1.10 ≤ n), still more preferably 1.20 or more (1.20 ≤ n), still more preferably 1.25 or more (1.25 ≤ n), still more preferably 1.30 or more (1.30 ≤ n), and still more preferably 1.50 or more (1.50 ≤ n). By being equal to or greater than the lower limit, the low dielectric properties (Dk and/or Df) of the compound (M) represented by the formula (M) tend to improve, and the low dielectric properties (Dk and/or Df) of the resin composition using the same or the cured product obtained also tend to improve. In particular, by setting it to 1.00 ≤ n, since the crystallinity of the compound (M) represented by the formula (M) decreases, the solvent solubility tends to improve. In addition, n is preferably 10.00 or less (n ≤ 10.00), more preferably 5.00 or less (n ≤ 5.00), still more preferably 3.00 or less (n ≤ 3.00), still more preferably 2.75 or less (n ≤ 2.75), and still more preferably 2.50 or less (n ≤ 2.50). By being equal to or less than the upper limit, the viscosity of the resin composition including the compound (M) represented by the formula (M) decreases, the impregnation property becomes good, and the moldability tends to be excellent.

The value of n can be calculated, for example, from the number average molecular weight obtained by measurement of gel permeation chromatography (GPC, detector: RI) of a compound (M) represented by formula (M), or from the area ratio of each separated peak.

In the present embodiment, the compound (M) represented by formula (M) preferably includes a compound represented by formula (M-1).

[Chemical Formula 15]

(In formula (M-1), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with a halogen atom. m represents an integer of 0 to 3, and n represents the average value of the repetition number, 1.00 ≤ n ≤ 20.00.)

In formula (M-1), R, m, and n have the same meanings as R, m, and n in formula (M), respectively, and their preferred ranges are also the same.

In the present embodiment, it is more preferable that the compound (M) represented by formula (M) includes a compound represented by formula (M-2).

[Chemical Formula 16]

(In formula (M-2), R ^z each independently represents a hydrocarbon group having 1 to 10 carbon atoms. m represents an integer of 0 to 3, and n represents the average value of the repetition number, 1.00 ≤ n ≤ 20.00.)

In formula (M-2), m and n have the same meanings as m and n in formula (M), respectively, and their preferred ranges are also the same.

R ^z is a hydrocarbon group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and more preferably at least one selected from the group consisting of a methyl group, an ethyl group, a propyl group (preferably an isopropyl group), a butyl group (preferably a sec-butyl group or a tert-butyl group), and a phenyl group, which may be substituted with a halogen atom.

In the present embodiment, a compound (M) represented by formula (M) (preferably in an n = 1 form included in the compound (M) represented by formula (M)) is a compound (MA) in which two terminal maleimide groups and an R ^mx (preferably a 2,2-propylidene group) closest to the maleimide groups are both positioned at a para position with respect to a benzene ring, a compound (MB) in which one of two terminal maleimide groups and an R ^mx (preferably a 2,2-propylidene group) closest to the maleimide groups are positioned at a meta position or an ortho position with respect to a benzene ring, and the other maleimide group and an R ^{mx (preferably a 2,2-propylidene group) closest to the maleimide group are positioned at a para position with respect to the benzene ring, and a compound (MB) in which two terminal maleimide groups and an R mx} (preferably a 2,2-propylidene group) closest to the maleimide groups are positioned at a para position with respect to the benzene ring ^. (Preferably, a 2,2-propylidene group) is preferably included in a compound (MC) in which all of the groups are positioned in the meta position or the ortho position with respect to the benzene ring. In this way, by forming a composition in which the compound (MA) and the compound (MB) and the compound (MC) having a high degree of freedom of rotation of the phenylenemaleimide group portion within the molecule are mixed, the degree of freedom of distribution of crosslinking reaction sites in the resin composition during the curing reaction increases, and a cured resin product having a more rigid network tends to be formed. As a result, the heat resistance (for example, glass transition temperature) and low thermal expansion property of the obtained cured product tend to be further improved.

In the above compound (MB) and compound (MC), it is preferable that the compound be one in which the terminal maleimide group and R ^mx (preferably a 2,2-propylidene group) are positioned in the ortho position with respect to the benzene ring.

In the present embodiment, in the HPLC analysis, among the compound (M) represented by the formula (M), the ratio of the compound (M-A) is preferably 90 area% or less, more preferably 80 area% or less, even more preferably 70 area% or less, and may be 50 area% or less, or 30 area% or less. By setting it to below the upper limit, since the crystallinity decreases, the solvent solubility tends to improve. In addition, the ratio of the compound (M-A) may be 0 area%, but is more preferably 2 area% or more, even more preferably 5 area% or more, and may be 10 area% or more. By setting the ratio of the compound (M-A) to 2 area% or more, there is a tendency for the decrease in reactivity to be effectively suppressed.

The ratio of the compound (M-A) preferably satisfies the above range when, in formula (M), 1.00 ≤ n ≤ 5.00, more preferably satisfies the above range when 1.00 ≤ n ≤ 3.00, and even more preferably satisfies the above range when n = 1. In addition, when the compound (M-A) contains the following compound as a main component (for example, at a ratio of 2 area% or more of the compound (M) represented by formula (M)), it is preferable to satisfy the above range.

[Chemical Formula 17]

In the present embodiment, in the HPLC analysis, the ratio of the compound (M-B) in the compound (M) represented by the formula (M) is preferably less than 60 area%, and preferably less than 55 area%. By setting it to the upper limit or lower, there is a tendency for the production cost of the compound (M) represented by the formula (M) or the reduction of industrial waste to be achieved. In addition, the ratio of the compound (M-B) is preferably 30 area% or more, more preferably 35 area% or more, and even more preferably 40 area% or more. When the ratio of the compound (M-B) having an asymmetric structure is 30 area% or more, in addition to improving the solvent solubility, there is a tendency for the low dielectric properties (Dk and/or Df) of the obtained cured product to be improved.

The ratio of the compound (M-B) preferably satisfies the above range when, in formula (M), 1.00 ≤ n ≤ 5.00, and more preferably satisfies the above range when 1.00 ≤ n ≤ 3.00. In addition, it is preferable that the range is satisfied when the compound (M-B) contains the following compound as a main component (for example, at a ratio of 30 mass% or more of the compound (M) represented by formula (M)).

[Chemical Formula 18]

In the present embodiment, in the HPLC analysis, among the compound (M) represented by the formula (M), the ratio of the compound (M-C) is preferably less than 60 area%, and more preferably less than 50 area%. In addition, the ratio of the compound (M-C) is preferably 15 area% or more, and more preferably 25 area% or more. When the ratio of the compound (M-C) is 15 area% or more, the low dielectric properties (Dk and/or Df) are more excellent, and when it is less than 60 area%, the curability and adhesion become good, and problems during the manufacture of substrates, etc. can be effectively suppressed.

The ratio of the compound (M-C) preferably satisfies the above range when, in formula (M), 1.00 ≤ n ≤ 5.00, and more preferably satisfies the above range when 1.00 ≤ n ≤ 3.00. In addition, it is preferable to satisfy the above range when the compound (M-C) contains the following compound as a main component (for example, at a ratio of 15 mass% or more of the compound represented by formula (M)).

[Chemical Formula 19]

In addition, in terms of the problem of crystallinity and the problem of deterioration of electrical characteristics, since the influence of the compound (M-A) is significant, the total ratio of the compound (M-B) and the compound (M-C) in the compound (M) represented by the formula (M) is preferably 50 area% or more, more preferably 60 area% or more, and particularly preferably 70 area% or more, with respect to the total amount of the compound (M-A), the compound (M-B), and the compound (M-C). The upper limit may be, for example, 100 area% or less, and further 99 area% or less.

In particular, in formula (M), it is preferable to satisfy the above range when 1.00 ≤ n ≤ 5.00, and it is more preferable to satisfy the above range when 1.00 ≤ n ≤ 3.00.

The softening point of the compound (M) represented by the formula (M) measured by the method according to JIS K-7234 is preferably 50°C or higher, more preferably 80°C or higher, even more preferably 90°C or higher, and particularly preferably 95°C or higher. The softening point is preferably 150°C or lower, more preferably 140°C or lower, even more preferably 130°C or lower, still more preferably 120°C or lower, and may be 110°C or lower or 100°C or lower.

The acid value of the compound (M) represented by formula (M) is preferably 30 mgKOH/g or less, and more preferably 1 to 15 mgKOH/g. If the acid value is high, there are many molecules that are not maleimidated, and since the structure having carboxylic acid becomes excessive, it affects the electrical characteristics and water resistance.

The weight average molecular weight (Mw) of the compound (M) represented by formula (M) is preferably 500 or more, and may further be 600 or more or 700 or more. By setting it to the lower limit or more, the low dielectric properties (Dk and/or Df) and low absorbency of the resulting cured product tend to be further improved. The upper limit of the weight average molecular weight (Mw) of the compound (M) represented by formula (M) is preferably 10,000 or less, more preferably 9,000 or less, still more preferably 7,000 or less, still more preferably 5,000 or less, still more preferably 3,000 or less, and still more preferably 1,000 or less. By setting it to the upper limit or less, the heat resistance and handleability of the resulting cured product tend to be further improved.

The method for synthesizing a compound (M) represented by formula (M) can refer to the descriptions in International Publication No. 2020-054601 and International Publication No. 2021-182360, and the contents of these are incorporated herein. When a compound (M) represented by formula (M) is synthesized by the method described in these publications, the compound (M) represented by formula (M) is obtained as a mixture of a compound (M-A), a compound (M-B), and a compound (M-C).

In addition, as the compound (M) represented by formula (M), a commercially available product may be used, and for example, MIR-5000 manufactured by Nippon Gunpowder Co., Ltd. (a compound in which m = 0 in formula (M-2)) can be mentioned. MIR-5000 can also be synthesized by the method described in the above publication.

In the resin composition of the present embodiment, it is preferable that the content of the compound (M) represented by the formula (M) is 1 to 90 parts by mass when the resin solid content in the resin composition is 100 parts by mass.

The lower limit of the content of the compound (M) represented by the formula (M) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, and may be 20 parts by mass or more, or may be 25 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the compound (M) represented by the formula (M) is equal to or more than the lower limit, the low dielectric properties (Dk and/or Df) of the resulting cured product tend to be improved. In addition, the upper limit of the content of the compound (M) represented by the formula (M) is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less, and may be 50 parts by mass or less, or 40 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the compound (M) represented by formula (M) is equal to or less than the upper limit, the heat resistance of the obtained cured product tends to improve.

The resin composition in the present embodiment may contain only one type of compound (M) represented by formula (M), or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

＜Polymer (V) having a structural unit represented by formula (V)＞

The resin composition of the present embodiment includes a polymer (V) having a structural unit represented by formula (V). By including the polymer (V) having a structural unit represented by formula (V), a resin composition having excellent low dielectric properties (low dielectric constant, low dielectric tangent) is obtained. In particular, by using it in combination with a compound (M) represented by formula (M), a cured resin product having a strong network is formed, so it is presumed that the resin composition has excellent low dielectric properties and also has an excellent low coefficient of thermal expansion (low CTE).

[Chemical formula 20]

(In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.)

The aromatic hydrocarbon linking group may be a group consisting solely of an aromatic hydrocarbon which may have a substituent, or a group consisting of a combination of an aromatic hydrocarbon which may have a substituent and another linking group. It is preferable that the aromatic hydrocarbon linking group is a group consisting solely of an aromatic hydrocarbon which may have a substituent. In addition, examples of the substituent that the aromatic hydrocarbon may have include a substituent Z (for example, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxy group, an amino group, a carboxyl group, a halogen atom, etc.). In addition, it is preferable that the aromatic hydrocarbon does not have a substituent.

Aromatic hydrocarbon linkages are typically divalent linkages.

The aromatic hydrocarbon linking group may specifically include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl group, a biphenyldiyl group, and a fluorenediyl group, which may have a substituent. Among these, a phenylene group which may have a substituent is preferable. As the substituent, the above-described substituent Z is exemplified, but it is preferable that the above-described phenylene group or the like does not have a substituent.

It is more preferable that the structural unit represented by formula (V) includes at least one of the structural unit represented by formula (V1) below, the structural unit represented by formula (V2) below, and the structural unit represented by formula (V3) below. In addition, * in the formulas below indicates a bonding position. In addition, hereinafter, the structural units represented by formulas (V1) to (V3) are sometimes collectively referred to as "structural unit (a)".

[Chemical Formula 21]

In formulas (V1) to (V3), L ¹ is an aromatic hydrocarbon linking group (preferably having 6 to 22 carbon atoms, more preferably 6 to 18 carbon atoms, and still more preferably 6 to 10 carbon atoms). Specifically, examples thereof include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl group, a biphenyldiyl group, and a fluorenediyl group, which may have a substituent, and among these, a phenylene group which may have a substituent is preferable. As the substituent, the above-described substituent Z is exemplified, but it is preferable that the above-described phenylene group or the like have no substituent.

As the compound forming the structural unit (a), a divinyl aromatic compound is preferable, and examples thereof include divinylbenzene, bis(1-methylvinyl)benzene, divinylnaphthalene, divinylanthracene, divinylbiphenyl, divinylphenanthrene, and the like. Among these, divinylbenzene is particularly preferable. Of these divinyl aromatic compounds, one type may be used, or two or more types may be used as needed.

The polymer (V) having a structural unit represented by formula (V) may be a homopolymer of the structural unit (a) as described above, or may be a copolymer with a structural unit derived from another monomer.

When the polymer (V) having a structural unit represented by formula (V) is a copolymer, the copolymerization ratio of the structural unit (a) is preferably 3 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, and may be 15 mol% or more. As an upper limit, it is preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, still more preferably 70 mol% or less, still more preferably 60 mol% or less, still more preferably 50 mol% or less, still more preferably 40 mol% or less, still still still preferably 30 mol% or less, and further may be 25 mol% or less, or 20 mol% or less.

As a structural unit derived from another monomer, a structural unit (b) derived from an aromatic compound having one vinyl group (monovinyl aromatic compound) is exemplified.

The structural unit (b) derived from a monovinyl aromatic compound is preferably a structural unit represented by the following formula (V4).

[Chemical Formula 22]

In formula (V4), L ² is an aromatic hydrocarbon linking group, and as a specific example of a preferred one, the example of L ¹ above can be given.

R ^V1 is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms (preferably an alkyl group). When R ^V1 is a hydrocarbon group, the carbon atoms are preferably 1 to 6, and more preferably 1 to 3. R ^V1 and L ² may have the substituent Z described above.

When the polymer (V) having a structural unit represented by formula (V) is a copolymer including a structural unit (b) derived from a monovinyl aromatic compound, examples of the monovinyl aromatic compound include vinyl aromatic compounds such as styrene, vinylnaphthalene, and vinylbiphenyl; nuclear alkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, p-ethylvinylbenzene, methylvinylbiphenyl, and ethylvinylbiphenyl. The monovinyl aromatic compounds exemplified here may appropriately have the substituent Z described above. In addition, these monovinyl aromatic compounds may be used alone or in combination of two or more.

When the polymer (V) having a structural unit represented by formula (V) is a copolymer including a structural unit (b), the copolymerization ratio of the structural unit (b) is preferably 10 mol% or more, more preferably 15 mol% or more, and further may be 20 mol% or more, 30 mol% or more, 40 mol% or more, 50 mol% or more, 60 mol% or more, 70 mol% or more, or 75 mol% or more. As an upper limit, it is preferably 98 mol% or less, more preferably 90 mol% or less, and still more preferably 85 mol% or less.

The polymer (V) having a structural unit represented by formula (V) may have other structural units other than the structural unit (a) and the structural unit (b). Examples of the other structural units include a structural unit (c) derived from a cycloolefin compound. Examples of the cycloolefin compound include hydrocarbons having a double bond in a ring structure. Specifically, in addition to monocyclic cyclic olefins such as cyclobutene, cyclopentene, cyclohexene, and cyclooctene, compounds having a norbornene ring structure such as norbornene and dicyclopentadiene, and cycloolefin compounds in which aromatic rings such as indene and acenaphthylene are condensed, and the like. Examples of norbornene compounds include those described in paragraphs 0037 to 0043 of Japanese Patent Application Laid-Open No. 2018-39995, the contents of which are incorporated herein by reference. Additionally, the cycloolefin compound exemplified herein may additionally have the substituent Z described above.

When the polymer (V) having a structural unit represented by formula (V) is a copolymer including a structural unit (c), the copolymerization ratio of the structural unit (c) is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more. As an upper limit, it is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and may be 50 mol% or less, or may be 30 mol% or less.

In the polymer (V) having the structural unit represented by formula (V), a structural unit (d) derived from a different polymerizable compound (hereinafter also referred to as another polymerizable compound) may be additionally introduced. As the other polymerizable compound (monomer), for example, a compound containing three vinyl groups can be mentioned. Specifically, 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, 1,2,4-trivinylcyclohexane can be mentioned. Alternatively, ethylene glycol diacrylate, butadiene, etc. can be mentioned. The copolymerization ratio of the structural unit (d) derived from the other polymerizable compound is preferably 30 mol% or less, more preferably 20 mol% or less, and still more preferably 10 mol% or less.

As one embodiment of a polymer (V) having a structural unit represented by formula (V), a polymer is exemplified which essentially comprises the structural unit (a) and includes at least one of the structural units (b) to (d). Furthermore, an embodiment is exemplified in which the total of the structural units (a) to (d) accounts for 95 mol% or more, further 98 mol% or more, of the total structural units.

As another embodiment of a polymer (V) having a structural unit represented by formula (V), the structural unit (a) is essential, and among all the structural units excluding the terminals, the structural unit including an aromatic ring is preferably 90 mol% or more, more preferably 95 mol% or more, and may be 100 mol%.

In addition, in calculating the mol% per total constituent unit, one constituent unit is defined as one derived from one molecule of a monomer (e.g., a divinyl aromatic compound, a monovinyl aromatic compound, etc.) used in the production of a polymer (V) having a constituent unit represented by formula (V).

The method for producing a polymer (V) having a structural unit represented by formula (V) is not particularly limited and may be a conventional method. For example, a method may be used in which a raw material including a divinyl aromatic compound is polymerized (if necessary, in the presence of a monovinyl aromatic compound, a cycloolefin compound, etc.) in the presence of a Lewis acid catalyst. As the Lewis acid catalyst, a metal fluoride such as boron trifluoride or a complex thereof can be used.

The structure of the chain terminal of the polymer (V) having the structural unit represented by formula (V) is not particularly limited, but, with respect to the group derived from the divinyl aromatic compound, it can be exemplified by one having the structure of the following formula (E1). In addition, L ¹ in formula (E1) is the same as defined in the above formula (V1). * indicates a bonding position.

*-CH=CH-L ¹ -CH=CH ₂ (E1)

When a group derived from a monovinyl aromatic compound becomes a chain terminal, it can take the structure of the following formula (E2). In the formula, L ² and R ^V1 have the same meanings as defined in the above formula (V4). * indicates a bonding position.

*-CH=CH-L ² -R ^V1 (E2)

The molecular weight of the polymer (V) having a structural unit represented by formula (V) is preferably 300 or more, more preferably 500 or more, still more preferably 1,000 or more, and still more preferably 1,500 or more, in terms of number average molecular weight Mn. As an upper limit, it is preferably 130,000 or less, more preferably 120,000 or less, still more preferably 110,000 or less, and still more preferably 100,000 or less.

The molecular weight of the polymer (V) having the structural unit represented by formula (V) is preferably 3,000 or more, more preferably 5,000 or more, and even more preferably 10,000 or more, in terms of the weight average molecular weight Mw. By setting it to be equal to or more than the above lower limit, the excellent low dielectric properties (Dk and/or Df) of the polymer (V) having the structural unit represented by formula (V), particularly the Df or dielectric properties after moisture absorption, can be effectively exerted in the cured product of the resin composition. The upper limit is preferably 130,000 or less, more preferably 100,000 or less, even more preferably 80,000 or less, and even more preferably 50,000 or less. By setting it to be equal to or less than the above upper limit, when the prepreg or resin sheet is laminated on a circuit forming substrate, there is a tendency that embedding defects are unlikely to occur.

The monodispersity (Mw/Mn), which is expressed by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn, is preferably 100 or less, more preferably 50 or less, and even more preferably 20 or less. As a lower limit, it is practically 1.1 or more, preferably 5 or more, more preferably 7 or more, and even more preferably 10 or more.

The above Mw and Mn are measured according to the description in the examples described below.

When the resin composition of the present embodiment contains two or more polymers (V) having a structural unit represented by formula (V), it is preferable that the Mw, Mn and Mw/Mn of the mixture satisfy the above ranges.

The equivalent weight of the vinyl group of the polymer (V) having the structural unit represented by formula (V) is preferably 200 g/eq. or more, more preferably 230 g/eq. or more, and even more preferably 250 g/eq. or more. In addition, the equivalent weight of the vinyl group is preferably 1200 g/eq. or less, more preferably 1000 g/eq. or less, and further may be 800 g/eq. or less, 600 g/eq. or less, 400 g/eq. or less, or 300 g/eq. or less. By setting it to the lower limit or more, the storage stability of the resin composition tends to improve, and the fluidity of the resin composition tends to improve. Therefore, the moldability improves, and voids are less likely to occur during formation of a prepreg or the like, and a more reliable printed wiring board tends to be obtained. On the other hand, by setting it to the upper limit or less, the heat resistance of the obtained cured product tends to improve.

In the present specification, the polymer (V) having a structural unit represented by formula (V) includes compounds described in paragraphs 0029 to 0058 of International Publication No. 2017/115813 and synthetic reaction conditions thereof, compounds described in paragraphs 0013 to 0058 of Japanese Patent Application Laid-Open No. 2018-039995 and synthetic reaction conditions thereof, compounds described in paragraphs 0008 to 0043 of Japanese Patent Application Laid-Open No. 2018-168347 and synthetic reaction conditions thereof, compounds described in paragraphs 0014 to 0042 of Japanese Patent Application Laid-Open No. 2006-070136 and synthetic reaction conditions thereof, compounds described in paragraphs 0014 to 0061 of Japanese Patent Application Laid-Open No. 2006-089683 and synthetic reaction conditions thereof, etc. Reference may be made to the compounds and their synthetic reaction conditions described in paragraphs 0008 to 0036 of Patent Publication No. 2008-248001, and they are incorporated herein by reference.

The resin composition of the present embodiment preferably has a content of a polymer (V) having a structural unit represented by formula (V) of 1 to 90 parts by mass when the resin solid content in the resin composition is 100 parts by mass.

The lower limit of the content of the polymer (V) having the structural unit represented by formula (V) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more, and may be 20 parts by mass or more, or may be 25 parts by mass or more, based on 100 parts by mass of the resin solid content in the resin composition. By setting the content of the polymer (V) having the structural unit represented by formula (V) to be equal to or greater than the lower limit above, low dielectric properties (Dk and/or Df), in particular, low relative permittivity, can be effectively achieved. Meanwhile, the upper limit of the content of the polymer (V) having the structural unit represented by formula (V) is more preferably 80 parts by mass or less, still more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less, and may be 50 parts by mass or less or 40 parts by mass or less, based on 100 parts by mass of the resin solid content in the resin composition. By setting the content of the polymer (V) having the structural unit represented by formula (V) to be equal to or less than the upper limit above, the metal foil peel strength of the obtained cured product can be effectively increased.

The polymer (V) having a structural unit represented by formula (V) may be included in the resin composition as one type, or as two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

＜Other thermosetting compounds (C)＞

The resin composition of the present embodiment may further contain at least one other thermosetting compound (C) selected from the group consisting of a maleimide compound, an epoxy compound, a phenol compound, an oxetane resin, a benzoxazine compound, a compound containing a (meth)allyl group (preferably an alkenylnadoimide compound), and a polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds, in addition to the compound (M) represented by the formula (M). By containing such a component, the desired performance required for a printed wiring board can be more effectively exhibited.

＜＜Maleimide compound other than compound (M) represented by formula (M)＞＞

The resin composition of the present embodiment may contain a maleimide compound other than the compound (M) represented by formula (M). The resin composition of the present embodiment is not particularly limited as long as it is a compound having 2 or more (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, still more preferably 2 or 3, and still more preferably 2) maleimide groups per molecule, and compounds commonly used in the field of printed wiring boards can be widely used.

In the present embodiment, the maleimide compound other than the compound (M) represented by the formula (M) is preferably a compound represented by the formulas (M2) to (M4) and (M6).

[Chemical Formula 23]

(In formula (M2), R ⁵⁴ each independently represents a hydrogen atom or a methyl group, and n ₄ represents an integer greater than or equal to 1.)

n ₄ is preferably an integer from 1 to 10, more preferably an integer from 1 to 5, still more preferably an integer from 1 to 3, and still more preferably 1 or 2.

The compound represented by formula (M2) may be a mixture of compounds in which n ₄ is different, and is preferably a mixture.

[Chemical Formula 24]

(In formula (M3), R ⁵⁵ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, and n ₅ represents an integer of 1 to 10.)

R ⁵⁵ is preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, or a phenyl group, more preferably one of a hydrogen atom and a methyl group, and even more preferably a hydrogen atom.

It is preferable that n ₅ is an integer greater than or equal to 1 and less than or equal to 5, more preferably an integer from 1 to 3, and even more preferably 1 or 2.

The compound represented by formula (M3) may be a mixture of compounds having different n ₅ , and is preferably a mixture.

[Chemical Formula 25]

(In formula (M4), each R ⁵⁶ independently represents a hydrogen atom, a methyl group, or an ethyl group, and each R ⁵⁷ independently represents a hydrogen atom or a methyl group.)

The maleimide compound (M6) is a compound having a structural unit represented by the formula (M6) and maleimide groups at both terminals of the molecular chain.

[Chemical Formula 26]

(In formula (M6), R ⁶¹ represents a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched alkenylene group having 2 to 16 carbon atoms. R ⁶² represents a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched alkenylene group having 2 to 16 carbon atoms. R ⁶³ each independently represents a linear or branched alkyl group having 1 to 16 carbon atoms, or a linear or branched alkenyl group having 2 to 16 carbon atoms. n each independently represents an integer of 0 to 10.)

Details of the maleimide compound (M6) and its production method can be referred to the description in paragraphs 0061 to 0066 of International Publication No. 2020/262577, and this content is incorporated herein.

Maleimide compounds other than the compound (M) represented by formula (M) may be produced by a known method, or commercially available products may be used. Commercially available products include, for example, a compound represented by formula (M2) manufactured by Daiwa Chemical Industries, Ltd., "BMI-2300"; a compound represented by formula (M3) manufactured by Nippon Gunplaza Co., Ltd., "MIR-3000"; a compound represented by formula (M4) manufactured by K.I. Chemical Co., Ltd., and a maleimide compound (M6) manufactured by Nippon Gunplaza Co., Ltd., "MIZ-001".

In addition, examples of maleimide compounds other than the above include compounds having two or more maleimide groups, and specific examples thereof include m-phenylenebismaleimide, 2,2-bis(4-(4-maleimidephenoxy)-phenyl)propane, 4-methyl-1,3-phenylenebismaleimide, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide, 1,3-bis(3-maleimidephenoxy)benzene, 1,3-bis(4-maleimidephenoxy)benzene, and prepolymers thereof, prepolymers of these maleimides and amines, and the like.

When a maleimide compound other than the compound (M) represented by formula (M) is included, the lower limit of the content is preferably 1 part by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and may be 20 parts by mass or more, with respect to 100 parts by mass of the resin solid content in the resin composition, and may be 25 parts by mass or more. When the content of the maleimide compound other than the compound (M) represented by formula (M) is 1 part by mass or more, the flame resistance of the resulting cured product tends to improve. In addition, the upper limit of the content of the maleimide compound other than the compound (M) represented by formula (M) is preferably 70 parts by mass or less, more preferably 50 parts by mass or less, and may be 40 parts by mass or less, with respect to 100 parts by mass of the resin solid content in the resin composition. When the content of a maleimide compound other than the compound (M) represented by formula (M) is 70 parts by mass or less, the metal foil peel strength and low absorbency tend to improve.

The resin composition in the present embodiment may contain only one type of maleimide compound other than the compound (M) represented by formula (M), or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain a maleimide compound other than the compound (M) represented by formula (M). Substantially not containing means that the content of the maleimide compound other than the compound (M) represented by formula (M) is less than 1 part by mass with respect to 100 parts by mass of the resin solid content in the resin composition, and is preferably less than 0.1 part by mass, and more preferably less than 0.01 part by mass.

＜＜Epoxy compound＞＞

The resin composition of the present embodiment may contain an epoxy compound.

The epoxy compound is not particularly limited as long as it is a compound or resin having 1 or more (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, still more preferably 2 or 3, and still more preferably 2) epoxy groups per molecule, and compounds commonly used in the field of printed wiring boards can be widely used.

Epoxy compounds include, for example, bisphenol A type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, bisphenol A novolac type epoxy resin, glycidyl ester type epoxy resin, aralkyl novolac type epoxy resin, biphenyl aralkyl type epoxy resin, naphthylene ether type epoxy resin, cresol novolac type epoxy resin, multifunctional phenol type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, naphthalene skeleton modified novolac type epoxy resin, phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, alicyclic epoxy resin, polyol type epoxy resin, phosphorus-containing epoxy resin, glycidylamine, glycidyl ester, butadiene, etc., compounds obtained by epoxidizing double bonds, hydroxyl group-containing silicone resins, and epichlorohydrin. Examples thereof include compounds obtained by the above. By using these, the moldability and adhesion of the resin composition are improved. Among these, from the viewpoint of further improving flame retardancy and heat resistance, biphenyl aralkyl type epoxy resins, naphthylene ether type epoxy resins, polyfunctional phenol type epoxy resins, and naphthalene type epoxy resins are preferable, and biphenyl aralkyl type epoxy resins are more preferable.

The resin composition of the present embodiment preferably contains an epoxy compound within a range that does not impair the effects of the present invention. When the resin composition of the present embodiment contains an epoxy compound, the content thereof is preferably 0.1 parts by mass or more, more preferably 1 parts by mass or more, and even more preferably 2 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the epoxy compound is 0.1 parts by mass or more, the metal foil peel strength and toughness of the resulting cured product tend to be improved. The upper limit of the content of the epoxy compound, when the resin composition of the present embodiment contains an epoxy compound, is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the epoxy compound is 50 parts by mass or less, the electrical properties of the resulting cured product tend to improve.

The resin composition in the present embodiment may contain only one type of epoxy compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain an epoxy compound. Substantially not containing means that the content of the epoxy compound is less than 0.1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition, preferably less than 0.01 part by mass, and further may be less than 0.001 part by mass.

＜＜Phenolic compounds＞＞

The resin composition of the present embodiment may contain a phenol compound.

The phenol compound is not particularly limited as long as it is a phenol compound having 1 or more (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, still more preferably 2 or 3, and still more preferably 2) phenolic hydroxyl groups per molecule, and compounds commonly used in the field of printed wiring boards can be widely used.

Examples of the phenol compound include bisphenol A type phenol resin, bisphenol E type phenol resin, bisphenol F type phenol resin, bisphenol S type phenol resin, phenol novolac resin, bisphenol A novolac type phenol resin, glycidyl ester type phenol resin, aralkyl novolac phenol resin, biphenyl aralkyl type phenol resin, cresol novolac type phenol resin, polyfunctional phenol resin, naphthol resin, naphthol novolac resin, polyfunctional naphthol resin, anthracene type phenol resin, naphthalene skeleton modified novolac type phenol resin, phenol aralkyl type phenol resin, naphthol aralkyl type phenol resin, dicyclopentadiene type phenol resin, biphenyl type phenol resin, alicyclic phenol resin, polyol type phenol resin, phosphorus-containing phenol resin, hydroxyl group-containing silicone resins, etc. Among these, from the viewpoint of further improving the flame retardancy of the obtained cured product, at least one selected from the group consisting of a biphenyl aralkyl type phenol resin, a naphthol aralkyl type phenol resin, a phosphorus-containing phenol resin, and a hydroxyl group-containing silicone resin is preferable.

The resin composition of the present embodiment preferably contains a phenol compound in a range that does not impair the effects of the present invention. When the resin composition of the present embodiment contains a phenol compound, the content thereof is preferably 0.1 parts by mass or more, more preferably 1 parts by mass or more, and even more preferably 2 parts by mass or more, with respect to 100 parts by mass of the resin solid content in the resin composition. In addition, it is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less, and may be 5 parts by mass or less.

The resin composition in the present embodiment may contain only one type of phenol compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain a phenol compound. Substantially not containing means that the content of the phenol compound is less than 0.1 mass part with respect to 100 mass parts of resin solid content in the resin composition.

＜＜Oxetane Resin＞＞

The resin composition of the present embodiment may contain an oxetane resin.

The oxetane resin is not particularly limited as long as it is a compound having 1 or more oxetanyl groups (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, still more preferably 2 or 3, and still more preferably 2), and compounds commonly used in the field of printed wiring boards can be widely used.

Examples of the oxetane resin include oxetane, alkyloxetane (e.g., 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, 3,3-dimethyloxetane, etc.), 3-methyl-3-methoxymethyloxetane, 3,3-di(trifluoromethyl)oxetane, 2-chloromethyloxetane, 3,3-bis(chloromethyl)oxetane, biphenyl type oxetane, OXT-101 (manufactured by Toa Synthetic Co., Ltd.), OXT-121 (manufactured by Toa Synthetic Co., Ltd.), etc.

The resin composition of the present embodiment preferably contains an oxetane resin within a range that does not impair the effects of the present invention. When the resin composition of the present embodiment contains an oxetane resin, the content thereof is preferably 0.1 parts by mass or more, more preferably 1 parts by mass or more, and even more preferably 2 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the oxetane resin is 0.1 parts by mass or more, the metal foil peel strength and toughness of the resulting cured product tend to be improved. The upper limit of the content of the oxetane resin, when the resin composition of the present embodiment contains an oxetane resin, is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of oxetane resin is 50 parts by mass or less, the electrical properties of the resulting cured product tend to improve.

The resin composition in the present embodiment may contain only one type of oxetane resin, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain an oxetane resin. Substantially not containing means that the content of the oxetane resin is less than 0.1 mass part with respect to 100 mass parts of resin solid content in the resin composition.

＜＜Benzoxazine compounds＞＞

The resin composition of the present embodiment may contain a benzoxazine compound.

As the benzoxazine compound, there is no particular limitation as long as it is a compound having 2 or more (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, still more preferably 2 or 3, and still more preferably 2) dihydrobenzoxazine rings in one molecule, and compounds commonly used in the field of printed wiring boards can be widely used.

Examples of benzoxazine compounds include bisphenol A type benzoxazine BA-BXZ (manufactured by Konishi Chemical Co., Ltd.), bisphenol F type benzoxazine BF-BXZ (manufactured by Konishi Chemical Co., Ltd.), and bisphenol S type benzoxazine BS-BXZ (manufactured by Konishi Chemical Co., Ltd.).

It is preferable that the resin composition of the present embodiment contains a benzoxazine compound within a range that does not impede the effects of the present invention. When the resin composition of the present embodiment contains a benzoxazine compound, the content thereof is preferably 0.1 parts by mass or more, and preferably 50 parts by mass or less, with respect to 100 parts by mass of the resin solid content in the resin composition.

The resin composition in the present embodiment may contain only one type of benzoxazine compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain a benzoxazine compound. Substantially not containing means that the content of the benzoxazine compound is less than 0.1 mass part with respect to 100 mass parts of resin solid content in the resin composition.

＜＜Compound containing (meth)allyl group＞＞

The resin composition of the present embodiment preferably contains a compound containing a (meth)allyl group, and more preferably contains a compound containing an allyl group.

In addition, the compound containing a (meth)allyl group is preferably a compound containing two or more (meth)allyl groups, and is more preferably a compound containing two or more allyl groups.

As the compound containing a (meth)allyl group, it is preferable to include at least one selected from the group consisting of an allyl isocyanurate compound, an allyl group-substituted nadimide compound, an allyl compound having a glycoluril structure, and diallyl phthalate, more preferably at least one selected from the group consisting of an allyl isocyanurate compound, an allyl group-substituted nadimide compound, and an allyl compound having a glycoluril structure, and it is even more preferable to include an allyl group-substituted nadimide compound, and an alkenyl nadimide compound is still more preferable.

When the resin composition of the present embodiment contains a compound containing a (meth)allyl group, the molecular weight thereof is preferably 195 or more, more preferably 300 or more, still more preferably 400 or more, and still more preferably 500 or more. By setting it to be equal to or greater than the lower limit, the low dielectric properties and heat resistance of the resulting cured product tend to be further improved. The molecular weight of the compound containing a (meth)allyl group is also preferably 3000 or less, more preferably 2000 or less, still more preferably 1000 or less, and still more preferably 800 or less. By setting it to be equal to or less than the upper limit, the low thermal expansion properties of the resulting cured product tend to be further improved.

When the resin composition of the present embodiment includes a compound including a (meth)allyl group, the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the compound including a (meth)allyl group to be equal to or greater than the above lower limit, the moldability of the resin composition tends to be excellent, and the heat resistance of the resulting cured product tends to be further improved. In addition, the upper limit of the content of the compound including a (meth)allyl group is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the compound including a (meth)allyl group to be equal to or less than the above upper limit, the low thermal expansion property of the resulting cured product tends to be further improved.

The resin composition of the present embodiment may contain only one type of compound containing a (meth)allyl group, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain a compound containing a (meth)allyl group. Substantially not containing means that the content of the compound containing a (meth)allyl group is less than 0.1 part by mass with respect to 100 parts by mass of the resin solid content in the resin composition.

＜＜＜Allyl isocyanurate compound＞＞＞

As an allyl isocyanurate compound, a compound represented by the formula (TA) is preferable, as long as it has two or more allyl groups and an isocyanurate ring (nurate skeleton), although not specifically specified.

Food (TA)

[Chemical Formula 27]

(In formula (TA), R ^A represents a substituent)

In the formula (TA), R ^A represents a substituent, and it is more preferable that it is a substituent having a formula number of 15 to 500.

The first example of R ^A is an alkyl group having 1 to 22 carbon atoms, or an alkenyl group having 2 to 22 carbon atoms. By using an allylic compound having an alkyl group having 1 to 22 carbon atoms, or an alkenyl group having 2 to 22 carbon atoms, it is possible to provide a resin composition which can obtain a cured product having excellent crosslinking properties and high toughness. Thereby, even when the resin composition does not include a substrate such as glass cloth, cracking or the like during etching treatment can be suppressed.

From the viewpoint of improving handling properties, the number of carbon atoms in the alkyl group and/or alkenyl group is preferably 3 or more, more preferably 8 or more, may be 12 or more, and preferably 18 or less. It is thought that thereby the resin flowability of the resin composition becomes good, and the circuit filling property, etc. when manufacturing a multilayer circuit board or the like using the resin composition of the present embodiment becomes more excellent.

A second example of R ^A is a group containing an allyl isocyanurate group. When R ^A contains an allyl isocyanurate group, the compound represented by the formula (TA) is preferably a compound represented by the formula (TA-1).

Food (TA-1)

[Chemical Formula 28]

(In formula (TA-1), R ^A2 is a divalent linker.)

In the formula (TA-1), R ^A2 is preferably a divalent linking group having a formula of 54 to 250, more preferably a divalent linking group having a formula of 54 to 250 and carbon atoms at both terminals, and still more preferably an aliphatic hydrocarbon group having 2 to 20 carbon atoms (however, the aliphatic hydrocarbon group may contain an ether group or may have a hydroxyl group). More specifically, R ^A2 is preferably a group represented by any one of the following formulas (i) to (iii).

[Chemical Formula 29]

(In formulas (i) to (iii), p ^c1 represents the number of repeating units of a methylene group and is an integer from 2 to 18. p ^c2 represents the number of repeating units of an oxyethylene group and is 0 or 1. * represents a bonding site.)

The above p ^c1 is preferably an integer of 2 to 10, more preferably an integer of 3 to 8, and even more preferably an integer of 3 to 5.

The above p ^c2 may be 0 or 1, but is preferably 1.

It is desirable that R ^A2 be the first example.

In this embodiment, it is preferable that the equivalent weight of the reactive group (allyl group) of the compound represented by the formula (TA) is 1000 or less. It is thought that when the equivalent weight is 1000 or less, a high Tg can be more reliably obtained.

The alkyl group having 1 to 22 carbon atoms may include a linear or branched alkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, a dodecyl group, and the like. In addition, the alkenyl group having 2 to 22 carbon atoms may include, for example, an allyl group, a decenyl group, and the like.

Specific examples of compounds represented by the formula (TA) include triallyl isocyanurate, 5-octyl-1,3-diallyl isocyanurate, 5-dodecyl-1,3-diallyl isocyanurate, 5-tetradecyl-1,3-diallyl isocyanurate, 5-hexadecyl-1,3-diallyl isocyanurate, 5-octadecyl-1,3-diallyl isocyanurate, 5-eicosyl-1,3-diallyl isocyanurate, 5-docosyl-1,3-diallyl isocyanurate, 5-decenyl-1,3-diallyl isocyanurate, etc. These may be used alone or in combination of two or more, and may be used as a prepolymer.

The method for producing a compound represented by the formula (TA) is not particularly limited, but can be obtained, for example, by reacting diallyl isocyanurate and an alkyl halide in an aprotic polar solvent such as N,N'-dimethylformamide, in the presence of a basic substance such as sodium hydroxide, potassium carbonate, or triethylamine, at a temperature of about 60°C to 150°C.

In addition, the compound represented by the formula (TA) can also be a commercially available one. As a commercially available one, there is no particular limitation, but examples thereof include L-DAIC manufactured by Shikoku Chemical Industry Co., Ltd. As for the triallyl isocyanurate, examples thereof include TAIC manufactured by Mitsubishi Chemical Industry Co., Ltd. As a compound represented by the formula (TA-1), examples thereof include DD-1 manufactured by Shikoku Chemical Industry Co., Ltd.

The molecular weight of the allyl isocyanurate compound (preferably the compound represented by the formula (TA)) is preferably 200 or more, more preferably 300 or more, still more preferably 400 or more, and still more preferably 500 or more. By making the molecular weight equal to or greater than the lower limit, the low dielectric properties and heat resistance of the resulting cured product tend to be further improved. In addition, the molecular weight of the allyl isocyanurate compound (preferably the compound represented by the formula (TA)) is preferably 3000 or less, more preferably 2000 or less, still more preferably 1000 or less, and still more preferably 800 or less. By making the molecular weight equal to or less than the upper limit, the low thermal expansion properties of the resulting cured product tend to be further improved.

When the resin composition of the present embodiment contains an allyl isocyanurate compound, the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the allyl isocyanurate compound to the lower limit or more, the moldability of the resin composition tends to be excellent, and the heat resistance of the resulting cured product tends to be further improved. In addition, the upper limit of the content of the allyl isocyanurate compound is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the allyl isocyanurate compound to the upper limit or less, the low thermal expansion property of the resulting cured product tends to be further improved.

The resin composition of the present embodiment may contain only one type of allyl isocyanurate, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

＜＜＜Allyl substituted nadirimide compounds＞＞＞

The allyl-substituted nadimide compound is not particularly limited as long as it is a compound having at least one allyl-substituted nadimide group in the molecule (preferably a compound having at least one nadimide group substituted with an alkenyl group in the molecule (alkenyl nadimide compound)). Specific examples thereof include compounds represented by the following formula (AN).

Food (AN)

[Chemical formula 30]

(In formula (AN), each R ₁ independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ₂ represents an alkylene group having 1 to 6 carbon atoms, a phenylene group, a biphenylene group, a naphthylene group, or a group represented by formula (AN-2) or (AN-3).

Food (AN-2)

[Chemical Formula 31]

(In formula (AN-2), R ₃ represents a methylene group, an isopropylidene group, -C(=O)-, -O-, -S-, or a group represented by -S(=O) ₂ -.)

Food (AN-3)

[Chemical formula 32]

(In formula (AN-3), each R ₄ independently represents an alkylene group having 1 to 4 carbon atoms, or a cycloalkylene group having 5 to 8 carbon atoms.)

In addition, the compound represented by the formula (AN) may be a commercially available one. The commercially available one is not particularly limited, and examples thereof include a compound represented by the formula (AN-4) (BANI-M (manufactured by Maruzen Petrochemical Co., Ltd.)), a compound represented by the formula (AN-5) (BANI-X (manufactured by Maruzen Petrochemical Co., Ltd.)), and the like. These may be used alone or in combination of two or more.

Food (AN-4)

[Chemical Formula 33]

Food (AN-5)

[Chemical Formula 34]

The molecular weight of the allyl-substituted nadoimide compound (preferably the compound represented by the formula (AN)) is preferably 400 or more, more preferably 500 or more, and may be 550 or more. By setting the molecular weight of the allyl-substituted nadoimide compound to be equal to or greater than the above lower limit, the low dielectric constant, low thermal expansion property, and heat resistance of the resulting cured product tend to be further improved. The molecular weight of the allyl-substituted nadoimide compound (preferably the compound represented by the formula (AN)) is further preferably 1500 or less, more preferably 1000 or less, even more preferably 800 or less, and may be 700 or less or 600 or less. By setting the molecular weight of the allyl-substituted nadoimide compound to be equal to or greater than the above upper limit, the moldability of the resin composition and the peel strength of the resulting cured product tend to be further improved.

When the resin composition of the present embodiment contains an allyl group-substituted nadimide compound (preferably a compound represented by the formula (AN)), the content thereof is preferably 0.1 parts by mass or more, more preferably 1 parts by mass or more, and even more preferably 2 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. In addition, it is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less, and may be 5 parts by mass or less. By setting the content of the allyl group-substituted nadimide compound to be equal to or less than the above upper limit, the moldability of the resin composition and the peel strength of the obtained cured product tend to be further improved.

The resin composition of the present embodiment may contain only one type of allyl-substituted nadirimide compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain an allyl group-substituted nadimide compound. “Substantially not containing” means that the content of the allyl group-substituted nadimide compound is less than 0.1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition.

＜＜＜Allyl compound having glycoluril structure＞＞＞

As for the allyl compound having a glycoluril structure, if it is a compound containing a glycoluril structure and two or more allyl groups, a compound represented by the formula (GU) is preferred, although it is not specifically defined.

Food (GU)

[Chemical Formula 35]

(In formula (GU), each R is independently a hydrogen atom or a substituent, and at least two of R are groups containing an allylic group.)

In the formula (GU), each R independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms, preferably an alkenyl group having 2 to 5 carbon atoms, and preferably an allyl group.

In the formula (GU), it is preferable that R is a group containing 3 or 4 allylic groups, and it is more preferable that R is a group containing 4 allylic groups.

A specific example of a compound represented by the formula (GU) includes 1,3,4,6-tetraallylglycoluril (a compound in which all R in the formula (GU) are allyl groups).

In addition, the compound represented by the formula (GU) can be a commercially available one. The commercially available one is not particularly limited, but examples thereof include TA-G manufactured by Shikoku Chemical Industry Co., Ltd.

The molecular weight of the allyl compound having a glycoluril structure (preferably a compound represented by the formula (GU)) is preferably 195 or more, more preferably 220 or more, still more preferably 250 or more, and may be 300 or more or 400 or more. By setting the molecular weight of the allyl compound having a glycoluril structure to be equal to or greater than the above lower limit, the low dielectric properties and heat resistance of the resulting cured product tend to be further improved. The molecular weight of the allyl compound having a glycoluril structure (preferably a compound represented by the formula (GU)) is further preferably 1500 or less, more preferably 1000 or less, still more preferably 800 or less, and may be 700 or less or 600 or less. By setting the molecular weight of the allyl compound having a glycoluril structure to be equal to or greater than the above upper limit, the low thermal expansion properties of the resulting cured product tend to be further improved.

When the resin composition of the present embodiment contains an allyl compound having a glycoluril structure (preferably a compound represented by the formula (GU)), the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the allyl compound having a glycoluril structure to be equal to or more than the lower limit above, the low dielectric constant and heat resistance of the resulting cured product tend to be further improved. In addition, the upper limit of the content of the allyl compound having a glycoluril structure (preferably a compound represented by the formula (GU)) is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, and may be 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the allyl compound having a glycoluril structure below the above upper limit, the low thermal expansion property of the obtained cured product tends to be further improved.

The resin composition of the present embodiment may contain only one type of allyl compound having a glycoluril structure, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

＜＜Polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds＞＞

The resin composition of the present embodiment may contain a polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds.

The polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds is preferably a polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds at the terminal, and is more preferably a polyphenylene ether compound having two or more groups selected from the group consisting of a (meth)acrylic group, a maleimide group, and a vinylbenzyl group at the terminal. By using these polyphenylene ether compounds, there is a tendency for the dielectric properties and low absorbency, etc. of printed wiring boards to be more effectively improved.

Below, these are explained in detail.

A polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds is exemplified by a compound having a phenylene ether skeleton represented by the following formula (X1).

[Chemical formula 36]

(In formula (X1), R ²⁴ , R ²⁵ , R ²⁶ , and R ²⁷ may be the same or different, and represent an alkyl group having 6 or fewer carbon atoms, an aryl group, a halogen atom, or a hydrogen atom.)

A polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds, formula (X2):

[Chemical Formula 37]

(In formula (X2), R ²⁸ , R ²⁹ , R ³⁰ , R ³⁴ , and R ³⁵ , which may be the same or different, represent an alkyl group or a phenyl group having 6 or fewer carbon atoms. R ³¹ , R ³² , and R ³³ , which may be the same or different, represent a hydrogen atom, an alkyl group or a phenyl group having 6 or fewer carbon atoms.)

A repeating unit represented by, and/or, formula (X3):

[Chemical formula 38]

(In formula (X3), R ³⁶ , R ³⁷ , R ³⁸ , R ³⁹ , R ⁴⁰ , R ⁴¹ , R ⁴² , and R ⁴³ may be the same or different and are a hydrogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group. -A- is a linear, branched, or cyclic divalent hydrocarbon group having 20 or fewer carbon atoms.) may additionally include a repeating unit represented by the following.

The polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds is preferably a modified polyphenylene ether compound having part or all of a terminal functionalized with an ethylenically unsaturated group (hereinafter, sometimes referred to as a "modified polyphenylene ether compound (g)"), and is more preferably a modified polyphenylene ether compound having two or more groups selected from the group consisting of a (meth)acrylic group, a maleimide group, and a vinylbenzyl group at the terminal. By employing such a modified polyphenylene ether compound (g), it becomes possible to further reduce the dielectric loss tangent (Df) of the cured product of the resin composition, and further to increase low water absorption and metal foil peel strength. These may be used alone or in combination of two or more.

As a modified polyphenylene ether compound (g), a compound represented by the formula (OP-1) can be mentioned.

[Chemical Formula 39]

(In formula (OP-1), X represents an aromatic group, -(YO)n ₂ - represents a polyphenylene ether structure, R ¹ , R ² , and R ³ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, n ₁ represents an integer of 1 to 6, n ₂ represents an integer of 1 to 100, and n ₃ represents an integer of 1 to 4.)

When n ₂ and/or n ₃ are integers greater than or equal to 2, the n ₂ constituent units (YO) and/or the n ₃ constituent units may be the same or different, respectively. n ₃ is preferably 2 or greater, and more preferably 2.

The modified polyphenylene ether compound (g) in the present embodiment is preferably a compound represented by the formula (OP-2).

[Chemical formula 40]

Here, -(O-X-O)- is the formula (OP-3):

[Chemical Formula 41]

(In formula (OP-3), R ⁴ , R ⁵ , R ⁶ , R ¹⁰ , and R ¹¹ , which may be the same or different, are an alkyl group or a phenyl group having 6 or fewer carbon atoms. R ⁷ , R ⁸ , and R ⁹ , which may be the same or different, are a hydrogen atom, an alkyl group or a phenyl group having 6 or fewer carbon atoms.)

and/or formula (OP-4):

[Chemical formula 42]

(In the formula (OP-4), R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ may be the same or different and are a hydrogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group. -A- is a linear, branched, or cyclic divalent hydrocarbon group having 20 or fewer carbon atoms.) is preferably represented by this.

Also, -(Y-O)- is, formula (OP-5):

[Chemical formula 43]

(In formula (OP-5), R ²⁰ and R ²¹ may be the same or different and are an alkyl group or a phenyl group having 6 or fewer carbon atoms. R ²² and R ²³ may be the same or different and are a hydrogen atom, an alkyl group or a phenyl group having 6 or fewer carbon atoms.) is preferably represented by this.

In formula (OP-2), a and b represent integers from 0 to 100, at least one of which is not 0, preferably an integer from 0 to 50, and more preferably an integer from 1 to 30. When a and/or b are integers of 2 or more, two or more -(Y-O)- may each independently be a structure in which one type of structure is arranged, or two or more types of structures may be arranged in a block or random manner.

Examples of -A- in the formula (OP-4) include, but are not limited to, divalent organic groups such as a methylene group, an ethylidene group, a 1-methylethylidene group, a 1,1-propylidene group, a 1,4-phenylenebis(1-methylethylidene) group, a 1,3-phenylenebis(1-methylethylidene) group, a cyclohexylidene group, a phenylmethylene group, a naphthylmethylene group, and a 1-phenylethylidene group.

Among the above modified polyphenylene ether compounds (g), a polyphenylene ether compound in which R ⁴ , R ⁵ , R ⁶ , R ¹⁰ , R ¹¹ , R ²⁰ , and R ²¹ are alkyl groups having 3 or fewer carbon atoms, and R ⁷ , R ⁸ , R ⁹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²² , and R ²³ are hydrogen atoms or alkyl groups having 3 or fewer carbon atoms is preferable, and in particular, a polyphenylene ether compound in which -(OXO)- represented by formula (OP-3) or formula (OP-4) is formula (OP-9), formula (OP-10), and/or formula (OP-11), and -(YO)- represented by formula (OP-5) is formula (OP-12) or formula (OP-13) is preferable. When a and/or b are integers of 2 or more, 2 or more -(YO)- may independently be a structure in which 2 or more of formulas (OP-12) and/or (OP-13) are arranged, or a structure in which formulas (OP-12) and (OP-13) are arranged in a block or random manner.

[Chemical Formula 44]

[Chemical Formula 45]

(In formula (OP-10), R ⁴⁴ , R ⁴⁵ , R ⁴⁶ , and R ⁴⁷ may be the same or different and are hydrogen atoms or methyl groups. -B- is a divalent hydrocarbon group having 20 or fewer carbon atoms, which is a straight-chain, branched, or cyclic chain.)

-B- can be given as a specific example the same as the specific example of -A- in formula (OP-4).

[Chemical Formula 46]

(In formula (OP-11), -B- is a divalent hydrocarbon group of a straight chain, branched or cyclic type having 20 or fewer carbon atoms.)

-B- can be given as a specific example the same as the specific example of -A- in formula (OP-4).

[Chemical formula 47]

[Chemical formula 48]

In addition, details of a polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds can be referred to the description in Japanese Patent Application Laid-Open No. 2018-016709, and these contents are incorporated herein.

The number average molecular weight (details are according to the method described in the Examples later) of polystyrene conversion by the GPC (gel permeation chromatography) method of a polyphenylene ether compound (preferably a modified polyphenylene ether compound (g)) containing two or more carbon-carbon unsaturated double bonds is preferably 500 or more and 3,000 or less. When the number average molecular weight is 500 or more, stickiness tends to be further suppressed when the resin composition of the present embodiment is formed into a coating film. When the number average molecular weight is 3,000 or less, solubility in a solvent tends to be further improved.

In addition, the weight average molecular weight (details are according to the method described in the Examples below) in terms of polystyrene by GPC of a polyphenylene ether compound (preferably a modified polyphenylene ether compound (g)) containing two or more carbon-carbon unsaturated double bonds is preferably 800 or more and 10,000 or less, and more preferably 800 or more and 5,000 or less. By setting it to be equal to or greater than the lower limit, the relative dielectric constant (Dk) and dielectric loss tangent (Df) of the cured product of the resin composition tend to be lowered, and by setting it to be equal to or less than the upper limit, the solubility, low viscosity, and formability of the resin composition in a solvent when producing a varnish or the like described below tend to be improved.

In addition, in the case of the modified polyphenylene ether compound (g), the terminal carbon-carbon unsaturated double bond equivalent is preferably 400 to 5,000 g per carbon-carbon unsaturated double bond, more preferably 400 to 2,500 g. By setting it to the lower limit or more, the dielectric constant (Dk) and dielectric loss tangent (Df) of the cured product of the resin composition tend to decrease further. By setting it to the upper limit or less, the solubility, low viscosity, and moldability of the resin composition in a solvent tend to improve further.

When the resin composition of the present embodiment includes a polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds, the lower limit of the content of the polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, still more preferably 7 parts by mass or more, and still more preferably 10 parts by mass or more, with respect to 100 parts by mass of the resin solid content in the resin composition. By setting it to the lower limit or more, the low water absorption and low dielectric properties (Dk and/or Df) of the obtained cured product tend to be further improved. In addition, the upper limit of the content of the polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, still more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less, still more preferably 35 parts by mass or less, still more preferably 25 parts by mass or less, and may be 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. By setting it to be equal to or less than the above upper limit, the heat resistance and chemical resistance of the obtained cured product tend to be further improved.

The resin composition in the present embodiment may contain only one type of polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain a polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds. Substantially not containing means that the content of the polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds is less than 0.1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition, preferably less than 0.01 part by mass, and further may be less than 0.001 part by mass.

When the resin composition of the present embodiment contains another thermosetting compound (C), its content (total amount) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, still more preferably 20 parts by mass or more, and may be 30 parts by mass or more, relative to 100 parts by mass of the resin solid content. By setting it to the lower limit or more, the heat resistance, plating adhesion, low thermal expansion property, etc. of the obtained cured product tends to be further improved. In addition, the upper limit of the content of the other thermosetting compound (C) is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, still more preferably 50 parts by mass or less, still more preferably 45 parts by mass or less, and may be 40 parts by mass or less, relative to 100 parts by mass of the resin solid content. By lowering it to the above upper limit, the low dielectric properties (Dk and/or Df) and low absorbency of the obtained cured product tend to be further improved.

The resin composition of the present embodiment may contain only one type of other thermosetting compound (C), or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

＜Filling Material (D)＞

The resin composition of the present embodiment preferably contains a filler (D). By containing a filler (D), the dielectric properties (low dielectric constant, low dielectric tangent, etc.), flame retardancy, low thermal expansion, etc. of the resin composition or its cured product can be further improved.

In addition, the filler (D) used in the present embodiment is more preferably excellent in low-dielectric properties (Dk and/or Df). For example, the filler (D) used in the present embodiment preferably has a dielectric constant (Dk) of 8.0 or less, more preferably 6.0 or less, and even more preferably 4.0 or less at a frequency of 10 GHz as measured by a cavity resonator perturbation method. In addition, the lower limit of the dielectric constant is, for example, 2.0 or more in practice. In addition, the filler (D) used in the present embodiment preferably has a dielectric loss tangent (Df) of 0.05 or less, more preferably 0.01 or less at a frequency of 10 GHz as measured by a cavity resonator perturbation method. In addition, the lower limit of the dielectric loss tangent is, for example, 0.0001 or more in practice.

As for the filler (D) used in this embodiment, its type is not particularly limited, and those generally used in the art can be preferably used. Specifically, silicas such as natural silica, fused silica, synthetic silica, amorphous silica, aerosil, and hollow silica; metal oxides such as alumina, white carbon, titanium white, titanium oxide, zinc oxide, magnesium oxide, and zirconium oxide; composite oxides such as zinc borate, zinc stannate, forsterite, barium titanate, strontium titanate, and calcium titanate; nitrides such as boron nitride, aggregated boron nitride, silicon nitride, and aluminum nitride; aluminum hydroxide, heat-treated aluminum hydroxide (aluminum hydroxide heat-treated to reduce some of the crystal water), boehmite, and metal hydroxides such as magnesium hydroxide (including hydrates); molybdenum compounds such as molybdenum oxide and zinc molybdate; barium sulfate, clay, kaolin, talc, calcined clay, calcined kaolin, calcined talc, mica, E-glass, In addition to inorganic fillers such as A-glass, NE-glass, C-glass, L-glass, D-glass, S-glass, M-glass G20, glass single fiber (including glass fine powders such as E-glass, T-glass, D-glass, S-glass, and Q-glass), hollow glass, and spherical glass, organic fillers such as styrene-type, butadiene-type, and acrylic-type rubber powder, core-shell-type rubber powder, silicone resin powder, silicone rubber powder, and silicone composite powder can be exemplified.

In the present embodiment, the inorganic filler is preferable, and it is more preferable that it contains at least one selected from the group consisting of silica, aluminum hydroxide, aluminum nitride, boron nitride, forsterite, titanium oxide, barium titanate, strontium titanate, and calcium titanate, and from the viewpoint of low dielectric characteristics (Dk and/or Df), it is more preferable that it contains at least one selected from the group consisting of silica and aluminum hydroxide, and it is still more preferable that it contains silica. By using these inorganic fillers, the properties of the cured product of the resin composition, such as heat resistance, dielectric characteristics, thermal expansion characteristics, dimensional stability, and flame retardancy, are further improved.

The content of the filler (D) in the resin composition of the present embodiment can be appropriately set depending on the desired characteristics and is not particularly limited, but is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 40 parts by mass or more, still more preferably 60 parts by mass or more, and still more preferably 80 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. By setting it to the lower limit or more, there is a tendency for the low thermal expansion properties and low dielectric constant properties of the obtained cured product to be further improved. In addition, the upper limit of the content of the filler (D) is preferably 1600 parts by mass or less, more preferably 1000 parts by mass or less, still more preferably 500 parts by mass or less, still more preferably 300 parts by mass or less, still more preferably 250 parts by mass or less, and may be 200 parts by mass or less, or 120 parts by mass or less, with respect to 100 parts by mass of the resin solid content. By setting it to be equal to or less than the above upper limit, there is a tendency for the moldability of the resin composition to be further improved.

In the resin composition of the present embodiment, as an example of a preferred embodiment, an embodiment in which the content of the filler (D) is 1 to 95 mass% of the components excluding the solvent is exemplified, and an embodiment in which it is 30 to 80 mass% is preferred.

The resin composition of the present embodiment may contain only one type of filler (D), or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In the resin composition of the present embodiment, when using a filler (D), particularly an inorganic filler, a silane coupling agent may be additionally included. By including a silane coupling agent, the dispersibility of the filler (D), the adhesive strength of the resin component, and the filler (D) and the substrate described below tend to be further improved.

The silane coupling agent is not particularly limited, and examples thereof include silane coupling agents generally used for surface treatment of inorganic substances, aminosilane compounds (e.g., γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, etc.), epoxysilane compounds (e.g., γ-glycidoxypropyltrimethoxysilane, etc.), vinylsilane compounds (e.g., vinyltrimethoxysilane, etc.), styrylsilane compounds (e.g., p-styryltrimethoxysilane, etc.), acrylsilane compounds (e.g., γ-acryloxypropyltrimethoxysilane, etc.), cationic silane compounds (e.g., N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride, etc.), phenylsilane compounds, etc. The silane coupling agent is used singly or in combination of two or more.

The content of the silane coupling agent is not particularly limited, but may be 0.1 to 5.0 parts by mass per 100 parts by mass of the resin solid content.

＜A low molecular weight vinyl compound having a molecular weight of less than 1000 and containing one organic group containing a carbon-carbon unsaturated bond in the molecule＞

The resin composition of the present embodiment may contain a low-molecular-weight vinyl compound having a molecular weight of less than 1000 and containing one organic group including a carbon-carbon unsaturated bond in the molecule (hereinafter, sometimes referred to simply as a “low-molecular-weight vinyl compound”). By blending a low-molecular-weight vinyl compound, the moisture absorption and heat resistance of the resulting cured product tends to be further improved.

Here, the carbon-carbon unsaturated bond constituting the organic group including the carbon-carbon unsaturated bond is intended to exclude those included as part of an aromatic ring. On the other hand, the carbon-carbon unsaturated bond included as part of a non-aromatic ring is intended to include. Examples of the carbon-carbon unsaturated bond included as part of a non-aromatic ring include a cyclohexenyl group and the like. In addition, the carbon-carbon unsaturated bond (for example, a vinylene group) included in a part other than the terminal of the organic group of a straight or branched chain is intended to include as well.

In the present embodiment, it is preferable that the organic group including the carbon-carbon unsaturated bond has a structure of CH ₂ = C(X)- (X is a hydrogen atom or a methyl group). In this way, by employing a compound including a carbon-carbon unsaturated bond at the end of the molecule, it becomes possible to react more effectively with the vinyl group of the polymer (V) having the structural unit represented by formula (V).

It is more preferable that the organic group containing the above carbon-carbon unsaturated bond is one selected from the group consisting of a vinyl group, an allyl group, an acrylic group, and a methacryl group, and it is even more preferable that it is a vinyl group.

The low-molecular-weight vinyl compound used in the present embodiment is preferably composed only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, oxygen atoms, nitrogen atoms, and silicon atoms, more preferably composed only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, oxygen atoms, and silicon atoms, and still more preferably composed only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, and oxygen atoms.

The low molecular weight vinyl compound used in the present embodiment may or may not have a polar group. It is preferable that the low molecular weight vinyl compound used in the present embodiment not have a polar group. Examples of the polar group include an amino group, a carboxyl group, a hydroxyl group, and a nitro group.

In the present embodiment, the molecular weight of the low-molecular-weight vinyl compound is preferably 70 or more, more preferably 80 or more, and even more preferably 90 or more. By setting it to the lower limit or more, there is a tendency for volatilization of the low-molecular-weight vinyl compound from the resin composition of the present embodiment or a cured product thereof to be suppressed. The upper limit of the molecular weight of the low-molecular-weight vinyl compound is preferably 500 or less, more preferably 400 or less, even more preferably 300 or less, still more preferably 200 or less, and may be 150 or less. By setting it to the upper limit or less, there is a tendency for the effect of enhancing the reactivity with a polymer (V) having a structural unit represented by formula (V) to be further enhanced.

When the resin composition of the present embodiment contains two or more low-molecular-weight vinyl compounds, it is preferable that the average molecular weight value of the low-molecular-weight vinyl compounds is within the above range, and it is more preferable that the molecular weight of each compound is within the above preferred range.

In the present embodiment, the low-molecular-weight vinyl compound preferably has a boiling point of 110°C or higher, more preferably 115°C or higher, and even more preferably 120°C or higher. By setting it to the lower limit or higher, volatilization of the low-molecular-weight vinyl compound when heat-curing the resin composition is suppressed, and the vinyl group of the polymer (V) having the structural unit represented by formula (V) can be reacted with the low-molecular-weight vinyl compound more effectively. The boiling point of the low-molecular-weight vinyl compound is preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 200°C or lower. By setting it to the upper limit or lower, it can be made difficult to remain as a residual solvent in the cured product.

When the resin composition of the present embodiment contains two or more low-molecular-weight vinyl compounds, the average value of the boiling points may be within the above range, but it is preferable that the boiling points of each compound be within the above preferred range.

Examples of low-molecular-weight vinyl compounds include (meth)acrylic acid ester compounds, aromatic vinyl compounds (preferably styrene-based compounds), saturated fatty acid vinyl compounds, vinyl cyanide compounds, ethylenically unsaturated carboxylic acids, ethylenically unsaturated carboxylic anhydrides, ethylenically unsaturated dicarboxylic acid monoalkyl esters, ethylenically unsaturated carboxylic acid amides, vinylsilane compounds (e.g., vinyltrialkoxysilane, etc.), acrylsilane compounds (e.g., acryltrialkoxysilane, etc.), methacrylsilane compounds (e.g., methacryltrialkoxysilane, etc.), and styrylsilane compounds (e.g., styryltrialkoxysilane, etc.).

The first type of low-molecular-weight vinyl compound is at least one selected from the group consisting of (meth)acrylic acid ester compounds, aromatic vinyl compounds, saturated fatty acid vinyl compounds, vinyl cyanide compounds, ethylenically unsaturated carboxylic acids, ethylenically unsaturated carboxylic anhydrides, ethylenically unsaturated dicarboxylic acid monoalkyl esters, and ethylenically unsaturated carboxylic acid amides.

The second type of low molecular weight vinyl compound is at least one selected from the group consisting of (meth)acrylic acid ester compounds, aromatic vinyl compounds, saturated fatty acid vinyl compounds, vinylsilane compounds, acrylsilane compounds, methacrylicsilane compounds, and styrylsilane compounds, with aromatic vinyl compounds and/or vinylsilane compounds being preferred.

Specific examples of low molecular weight vinyl compounds include methyl styrene, ethyl vinyl benzene, vinyl trimethoxysilane, and vinyl triethoxysilane.

In the resin composition of the present embodiment, the content of the low-molecular-weight vinyl compound is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 2.5 parts by mass or more, relative to 100 parts by mass of the resin solid content. By setting it to the lower limit or more, the unreacted functional group in the obtained cured product tends to decrease, and the moisture absorption and heat resistance tends to improve. In addition, the upper limit of the content of the low-molecular-weight vinyl compound is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, still more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less, relative to 100 parts by mass of the resin solid content. By setting it to the upper limit or less, the low-dielectric properties (Dk and/or Df) of the obtained cured product tend to be further improved.

The resin composition of the present embodiment may contain only one type of low-molecular-weight vinyl compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In the resin composition of the present embodiment, the mass ratio of the polymer (V) having the structural unit represented by the formula (V) and the low-molecular-weight vinyl compound is preferably 0.025 or more, and more preferably 0.05 or more, with respect to the polymer (V) 1 having the structural unit represented by the formula (V). By setting it to the lower limit or more, the unreacted functional group in the obtained cured product tends to decrease, and the moisture absorption and heat resistance tends to improve. The upper limit of the mass ratio of the polymer (V) having the structural unit represented by the formula (V) and the low-molecular-weight vinyl compound is preferably 0.7 or less, more preferably 0.5 or less, still more preferably 0.4 or less, still more preferably 0.3 or less, and may be 0.25 or less, with respect to the polymer (V) 1 having the structural unit represented by the formula (V). By lowering it to the above upper limit, the low dielectric properties (Dk and/or Df) of the obtained cured product tend to be further improved.

＜Oligomers with ethylenically unsaturated groups＞

In the resin composition of the present embodiment, it is also possible to use an oligomer having an ethylenically unsaturated group in combination in order to enhance thermosetting properties and curability by active energy rays (for example, photocurability by ultraviolet rays, etc.). The oligomer having an ethylenically unsaturated group used in the present embodiment is not particularly limited as long as it is an oligomer having one or more ethylenically unsaturated groups in one molecule, and examples thereof include oligomers having a vinyl group, an allyl group, a (meth)acryloyl group, and the like, and an oligomer having a vinyl group is preferable.

In addition, in the present specification, a compound corresponding to an oligomer having an ethylenically unsaturated group, which is also a polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds, is referred to as a polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds.

The oligomer having an ethylenically unsaturated group is preferably a styrene oligomer. The styrene oligomer related to the present embodiment is preferably formed by polymerizing at least one selected from the group consisting of styrene, the styrene derivative, and vinyltoluene. The number average molecular weight of the styrene oligomer is preferably 178 or more, and further preferably 1600 or less. In addition, the styrene oligomer is preferably a compound without a branched structure having an average number of aromatic rings of 2 to 14, a total amount of 2 to 14 aromatic rings of 50 mass% or more, and a boiling point of 300°C or more.

Examples of the styrene oligomer used in the present embodiment include a styrene polymer, a vinyltoluene polymer, an α-methylstyrene polymer, a vinyltoluene-α-methylstyrene polymer, and a styrene-α-styrene polymer. As the styrene polymer, a commercially available product may be used, and examples thereof include Picolastic A5 (manufactured by Eastman Chemical Co., Ltd.), Picolastic A-75 (manufactured by Eastman Chemical Co., Ltd.), Picotex 75 (manufactured by Eastman Chemical Co., Ltd.), FTR-8100 (manufactured by Mitsui Chemical Co., Ltd.), and FTR-8120 (manufactured by Mitsui Chemical Co., Ltd.). In addition, as the vinyltoluene-α-methylstyrene polymer, an example thereof includes Picotex LC (manufactured by Eastman Chemical Co., Ltd.). In addition, examples of α-methylstyrene polymers include Crystalex 3070 (manufactured by Eastman Chemical Co., Ltd.), Crystalex 3085 (manufactured by Eastman Chemical Co., Ltd.), Crystalex (3100), Crystalex 5140 (manufactured by Eastman Chemical Co., Ltd.), FMR-0100 (manufactured by Mitsui Chemical Co., Ltd.), and FMR-0150 (manufactured by Mitsui Chemical Co., Ltd.). In addition, examples of styrene-α-styrene polymers include FTR-2120 (manufactured by Mitsui Chemical Co., Ltd.). These styrene oligomers may be used alone or in combination of two or more.

In the resin composition of the present embodiment, α-methylstyrene oligomer is preferable in that it is excellent in that it is thermally cured well, has excellent fine wiring embedding properties, solder heat resistance, low dielectric constant, and low dielectric tangent.

When the resin composition of the present embodiment contains an oligomer having an ethylenically unsaturated group, the content thereof is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, still more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and further may be 5 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. By setting it to the lower limit or more, the low dielectric constant of the resulting cured product tends to be further improved. In addition, the upper limit of the content of the oligomer having an ethylenically unsaturated group is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less, and still more preferably 10 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. By setting it to the upper limit or less, the heat resistance of the resulting cured product tends to be further improved. In addition, the low dielectric constant, low dielectric tangent, and chemical resistance of the obtained cured product tend to be further improved.

The resin composition of the present embodiment may contain only one type of oligomer having an ethylenically unsaturated group, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

＜Thermoplastic elastomer＞

The resin composition of the present embodiment may contain a thermoplastic elastomer.

The thermoplastic elastomer in the present embodiment is not particularly limited, and may include, for example, at least one selected from the group consisting of polyisoprene, polybutadiene, styrene butadiene, butyl rubber, ethylene propylene rubber, styrene butadiene ethylene, styrene butadiene styrene, styrene isoprene styrene, styrene ethylene butylene styrene, styrene propylene styrene, styrene ethylene propylene styrene, fluorine rubber, silicone rubber, hydrogenated compounds thereof, alkyl compounds thereof, and copolymers thereof.

The number average molecular weight of the thermoplastic elastomer used in the present embodiment is preferably 50,000 or more. By setting the number average molecular weight to 50,000 or more, the low dielectric properties (Dk and/or Df) of the resulting cured product tend to be more excellent. The number average molecular weight is preferably 60,000 or more, more preferably 70,000 or more, and even more preferably 80,000 or more. The upper limit of the number average molecular weight of the thermoplastic elastomer is preferably 400,000 or less, more preferably 350,000 or less, and even more preferably 300,000 or less. By setting it to be equal to or less than the above upper limit, the solubility of the thermoplastic elastomer component in the resin composition tends to be improved.

When the resin composition of the present embodiment contains two or more types of thermoplastic elastomers, it is preferable that the number average molecular weight of their mixture satisfies the above range.

In the present embodiment, the thermoplastic elastomer is preferably a thermoplastic elastomer comprising a styrene monomer unit and a conjugated diene monomer unit (hereinafter referred to as “thermoplastic elastomer (E)”). By using such a thermoplastic elastomer (E), the low dielectric properties (Dk and/or Df) of the resulting cured product are more excellent.

The above thermoplastic elastomer (E) contains a styrene monomer unit. By containing a styrene monomer unit, the solubility of the thermoplastic elastomer (E) in the resin composition is improved. Examples of the styrene monomer include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene (vinylstyrene), N,N-dimethyl-p-aminoethylstyrene, N,N-diethyl-p-aminoethylstyrene, and the like, and among these, styrene, α-methylstyrene, and p-methylstyrene are preferable from the viewpoints of availability and productivity. Among these, styrene is particularly preferable.

The content of the styrene monomer unit in the thermoplastic elastomer (E) is preferably in the range of 10 to 50 mass% of the total monomer units, more preferably in the range of 13 to 45 mass%, and even more preferably in the range of 15 to 40 mass%. When the content of the styrene monomer unit is 50 mass% or less, the adhesion and adhesiveness with a substrate, etc. become better. In addition, when it is 10 mass% or more, adhesion growth can be suppressed, glue residue or stop marks are unlikely to occur, and the ease of peeling between adhesive surfaces tends to become better, which is preferable.

The thermoplastic elastomer (E) may contain only one type of styrene monomer unit, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

The method for measuring the content of styrene monomer units in the thermoplastic elastomer (E) of the present embodiment can refer to the description in International Publication No. 2017/126469, the contents of which are incorporated herein by reference. The same applies to the conjugated diene monomer units described later, etc.

The thermoplastic elastomer (E) above contains a conjugated diene monomer unit. By containing the conjugated diene monomer unit, the solubility of the thermoplastic elastomer (E) in the resin composition is improved. The conjugated diene monomer is not particularly limited as long as it is a diolefin having one pair of conjugated double bonds. Examples of the conjugated diene monomer include 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 farnesene, with 1,3-butadiene and isoprene being preferable, and 1,3-butadiene being more preferable.

The thermoplastic elastomer (E) may contain only one type of conjugated diene monomer unit, or may contain two or more types.

In the thermoplastic elastomer (E), the mass ratio of the styrene monomer unit to the conjugated diene monomer unit is preferably in the range of styrene monomer unit/conjugated diene monomer unit = 5/95 to 80/20, more preferably in the range of 7/93 to 77/23, and still more preferably in the range of 10/90 to 70/30. When the mass ratio of the styrene polymer unit to the conjugated diene monomer unit is in the range of 5/95 to 80/20, adhesion increase can be suppressed to maintain high adhesion, and the ease of peeling between adhesive surfaces becomes good.

The thermoplastic elastomer (E) above may have all, some, or none of the conjugated diene bonds of the thermoplastic elastomer hydrogenated.

The above thermoplastic elastomer (E) may or may not contain other monomer units in addition to the styrene monomer unit and the conjugated diene monomer unit. Examples of the other monomer units include aromatic vinyl compound units other than the styrene monomer unit.

The thermoplastic elastomer (E) preferably has a total of styrene monomer units and conjugated diene monomer units of 90 mass% or more, more preferably 95 mass% or more, still more preferably 97 mass% or more, and still more preferably 99 mass% or more, of the total monomer units.

As described above, the thermoplastic elastomer (E) may contain only one type of styrene monomer unit and one type of conjugated diene monomer unit, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

The thermoplastic elastomer (E) used in the present embodiment may be a block polymer or a random polymer. In addition, it may be a hydrogenated elastomer in which the conjugated diene monomer unit is hydrogenated, an unhydrogenated elastomer in which hydrogen is not added, or a partially hydrogenated elastomer in which hydrogen is partially added.

In one embodiment of the present embodiment, the thermoplastic elastomer (E) is an unhydrogenated elastomer.

An unhydrogenated elastomer refers to an elastomer in which the proportion of double bonds based on conjugated diene monomer units in the elastomer that are hydrogenated, i.e., the hydrogenation rate (hydrogenation rate) is 20% or less. The hydrogenation rate is preferably 15% or less, more preferably 10% or less, and still more preferably 5% or less.

Examples of commercially available thermoplastic elastomers (E) used in the present embodiment include SEPTON (registered trademark) 2104 manufactured by Kuraray Co., Ltd., S.O.R. (registered trademark) S1606, S1613, S1609, S1605 manufactured by Asahi Kasei Co., Ltd., DYNARON (registered trademark) 9901P, TR2250 manufactured by JSR Co., Ltd., etc.

When the resin composition of the present embodiment contains a thermoplastic elastomer (preferably a thermoplastic elastomer (E)), the content thereof is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and may be 15 parts by mass or more, relative to 100 parts by mass of the resin solid content. By setting it to be equal to or more than the above lower limit, the low dielectric properties (Dk and/or Df) of the resulting cured product tend to be further improved. In addition, the upper limit of the content of the thermoplastic elastomer is preferably 45 parts by mass or less, more preferably 40 parts by mass or less, even more preferably 35 parts by mass or less, even more preferably 30 parts by mass or less, and may be 25 parts by mass or less, relative to 100 parts by mass of the resin solid content. By setting it to be equal to or less than the above upper limit, the heat resistance of the resulting cured product tends to be further improved.

The resin composition of the present embodiment may contain only one type of thermoplastic elastomer, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

＜Flame retardant＞

The resin composition of the present embodiment may contain a flame retardant. Examples of the flame retardant include phosphorus-based flame retardants, halogen-based flame retardants, inorganic flame retardants, and silicone-based flame retardants, and phosphorus-based flame retardants are preferred.

As the flame retardant, known flame retardants can be used, for example, halogen flame retardants such as brominated epoxy resin, brominated polycarbonate, brominated polystyrene, brominated styrene, brominated phthalimide, tetrabromobisphenol A, pentabromobenzyl (meth)acrylate, pentabromotoluene, tribromophenol, hexabromobenzene, decabromodiphenyl ether, bis-1,2-pentabromophenylethane, chlorinated polystyrene, and chlorinated paraffin, red phosphorus, tricresyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, trixylenyl phosphate, trialkyl phosphate, dialkyl phosphate, tris (chloroethyl) phosphate, phosphazene, 1,3-phenylenebis (2,6-disylenyl phosphate), Examples include phosphorus-based flame retardants such as 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide, partial boehmite, boehmite, zinc borate, and antimony trioxide; and silicone-based flame retardants such as silicone rubber and silicone resin.

In the present embodiment, among these, 1,3-phenylenebis(2,6-disylenylphosphate) is preferable in that it does not inhibit the low dielectric properties (Dk and/or Df).

When the resin composition of the present embodiment contains a flame retardant, the content thereof is preferably 1 part by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and may be 15 parts by mass or more, with respect to 100 parts by mass of the resin solid content in the resin composition. In addition, the lower limit of the content of the flame retardant is preferably 30 parts by mass or less, and more preferably 25 parts by mass or less.

Flame retardants can be used singly or in combination of two or more types. When two or more types are used, the total amount is within the above range.

＜Active ester compound＞

The resin composition of the present embodiment may contain an active ester compound within a range that does not impede the effects of the present invention. The active ester compound is not particularly limited, and for example, reference can be made to the description in paragraphs 0064 to 0066 of International Publication No. 2021/172317, the contents of which are incorporated herein.

When the resin composition of the present embodiment contains an active ester compound, it is preferably 1 part by mass or more, and further preferably 50 parts by mass or less, with respect to 100 parts by mass of the resin solid content in the resin composition.

The resin composition in the present embodiment may contain only one type of active ester compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

In addition, the resin composition in the present embodiment may be configured to substantially not contain an active ester compound. Substantially not containing means that the content of the active ester compound is less than 1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition, preferably less than 0.1 part by mass, and more preferably less than 0.01 part by mass.

＜Dispersant＞

The resin composition of the present embodiment may contain a dispersant. As the dispersant, those generally used for paints can be preferably used, and the type thereof is not particularly limited. As the dispersant, a copolymer-based wetting dispersant is preferably used, and specific examples thereof include DISPERBYK (registered trademark)-110, 111, 161, 180, 2009, 2152, 2155, BYK (registered trademark)-W996, W9010, W903, W940 manufactured by Big Chemie Japan Co., Ltd.

When the resin composition of the present embodiment contains a dispersant, the lower limit of the content is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and may be 0.3 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. In addition, the upper limit of the content of the dispersant is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and may be 3 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition.

Dispersants can be used singly or in combination of two or more types. When two or more types are used, the total amount is within the above range.

＜Curing Accelerator＞

The resin composition of the present embodiment may further contain a curing accelerator. Examples of the curing accelerator include, but are not particularly limited to, imidazoles such as 2-ethyl-4-methylimidazole and triphenylimidazole; organic peroxides such as benzoyl peroxide, lauroyl peroxide, acetyl peroxide, parachlorobenzoyl peroxide, di-tert-butyl-di-perphthalate, α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3; azo compounds such as azobisnitrile; Tertiary amines such as N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2-N-ethylanilinoethanol, tri-n-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, tetramethylbutanediamine, and N-methylpiperidine; phenols such as phenol, xylenol, cresol, resorcin, and catechol; high-temperature decomposition type radical generators such as 2,3-dimethyl-2,3-diphenylbutane; organometallic salts such as lead naphthenate, lead stearate, zinc naphthenate, zinc octylate, manganese octylate, tin oleate, dibutyltin maleate, manganese naphthenate, cobalt naphthenate, and iron acetylacetone; Examples thereof include those produced by dissolving these organometallic salts in hydroxyl group-containing compounds such as phenol and bisphenol; inorganic metal salts such as tin chloride, zinc chloride, and aluminum chloride; and organic tin compounds such as dioctyltin oxide, other alkyl tins, and alkyl tin oxides.

Preferred curing accelerators are imidazoles and organometallic salts, and it is more preferable to use a combination of both imidazoles and organometallic salts.

When the resin composition of the present embodiment contains a curing accelerator, the lower limit of the content thereof is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. In addition, the upper limit of the content of the curing accelerator is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 2 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition.

The curing accelerator can be used singly or in combination of two or more types. When two or more types are used, the total amount is within the above range.

＜Solvent＞

The resin composition of the present embodiment may contain a solvent, and preferably contains an organic solvent. When containing a solvent, the resin composition of the present embodiment is in a form (solution or varnish) in which at least a portion, preferably all, of the various resin solid components described above are dissolved or dissolved in the solvent. The solvent is not particularly limited as long as it is a polar organic solvent or non-polar organic solvent that can dissolve or be compatible with at least a part, preferably all, of the various resin solid contents described above. Examples of the polar organic solvent include ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), cellosolves (e.g., propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, etc.), esters (e.g., ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, isoamyl acetate, ethyl lactate, methyl methoxypropionate, methyl hydroxyisobutyrate, etc.), amides (e.g., dimethoxyacetamide, dimethylformamide, etc.), and examples of the non-polar organic solvent include aromatic hydrocarbons (e.g., toluene, xylene, etc.).

The solvent can be used singly or in combination of two or more types. When two or more types are used, the total amount is within the above range.

＜Other ingredients＞

The resin composition of the present embodiment may contain, in addition to the above components, various polymer compounds such as thermoplastic resins and their oligomers, and various additives. Examples of the additives include ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent whitening agents, photosensitizers, dyes, pigments, thickeners, flow regulators, lubricants, defoaming agents, leveling agents, brighteners, polymerization inhibitors, and the like. These additives may be used singly or in combination of two or more.

＜Usage＞

The resin composition of the present embodiment is used as a cured product. Specifically, the resin composition of the present embodiment can be suitably used as a resin composition for electronic materials, such as an insulating layer of a printed wiring board, a material for a semiconductor package, etc., as a low-dielectric constant material and/or a low-dielectric tangent material. The resin composition of the present embodiment can be suitably used as a prepreg, a metal foil-clad laminate using a prepreg, a resin composite sheet, and a material for a printed wiring board.

The resin composition of the present embodiment preferably has a low dielectric constant (Dk) when molded into a cured plate having a thickness of 0.8 mm. Specifically, the dielectric constant (Dk) at a frequency of 10 GHz as measured by a cavity resonator perturbation method is preferably 2.60 or less, and more preferably 2.50 or less. The lower limit of the dielectric constant (Dk) is not specifically set, but is practically 0.01 or more, for example.

In addition, it is preferable that the resin composition of the present embodiment has a low dielectric constant (Df) when molded into a cured plate having a thickness of 0.8 mm. Specifically, the dielectric constant (Df) at a frequency of 10 GHz as measured by a cavity resonator perturbation method is preferably less than 0.0026, and more preferably less than 0.0023. The lower limit of the dielectric constant (Df) is not specifically set, but, for example, 0.0001 or more is practical.

Such low dielectric properties (Dk and/or Df) are achieved primarily by using a polymer (V) having a structural unit represented by formula (V).

The dielectric constant (Dk) and dielectric loss tangent (Df) of the above-mentioned hardened plate are measured, more specifically, by the method described in the examples described below.

The cured product of the resin composition of the present embodiment preferably has a glass transition temperature (Tanδ) of 230°C or higher, more preferably 250°C or higher, as measured by DMA (dynamic mechanical measurement). Such a high glass transition temperature is achieved mainly by using a compound (M) represented by the formula (M). The upper limit of the glass transition temperature is practically 350°C or lower, for example.

The glass transition temperature (Tanδ) is measured, more specifically, by the method described in the examples below.

The cured product of the resin composition of the present embodiment preferably has a low coefficient of thermal expansion (CTE). Specifically, when molded into a cured plate having a thickness of 0.8 mm, the linear thermal expansion coefficient in the direction perpendicular to the plane measured by the TMA method specified in JIS C 6481 5.19 is preferably 80 ppm/°C or less, more preferably 70 ppm/°C or less. As for the lower limit, 0 is ideal, but 0.001 ppm/°C or more is practical.

The CTE is measured by the method described in the examples described below.

The resin composition of the present embodiment is used as a layered material (including a film shape, a sheet shape, etc.) such as a prepreg or a resin composite sheet that becomes an insulating layer of a printed wiring board. When such a layered material is used, the thickness is preferably 5 µm or more, and more preferably 10 µm or more. The upper limit of the thickness is preferably 200 µm or less, and more preferably 180 µm or less. In addition, the thickness of the layered material means the thickness including the glass cloth, for example, when the resin composition of the present embodiment is impregnated into glass cloth or the like.

The material formed by the resin composition of the present embodiment may be used for a purpose in which a pattern is formed by exposure development, or may be used for a purpose in which no exposure development is performed. It is particularly suitable for a purpose in which no exposure development is performed.

＜＜Prepreg＞＞

The prepreg of the present embodiment is formed of a substrate (prepreg substrate) and the resin composition of the present embodiment. The prepreg of the present embodiment is obtained, for example, by applying (for example, impregnating and/or coating) the resin composition of the present embodiment to a substrate and then semi-curing by heating (for example, a method of drying at 120 to 220° C. for 2 to 15 minutes). In this case, the amount of adhesion of the resin composition to the substrate, i.e., the amount of the resin composition (including the filler (D)) relative to the total amount of the prepreg after semi-curing, is preferably in the range of 20 to 99 mass%, and more preferably in the range of 20 to 80 mass%.

As for the substrate, there is no particular limitation as long as it is a substrate used for various printed wiring board materials. As a material of the substrate, examples thereof include glass fiber (e.g., E-glass, D-glass, L-glass, S-glass, T-glass, Q-glass, UN-glass, NE-glass, spherical glass, etc.), inorganic fibers other than glass (e.g., quartz), and organic fibers (e.g., polyimide, polyamide, polyester, liquid crystal polyester, polytetrafluoroethylene, etc.). As for the form of the substrate, there is no particular limitation, and examples thereof include woven fabric, nonwoven fabric, roving, chopped strand mat, and surfacing mat. These substrates may be used alone or in combination of two or more. Among these substrates, from the viewpoint of dimensional stability, a woven fabric that has been subjected to ultra-opening treatment or blind-filling treatment is preferable, from the viewpoint of strength and low absorbency, the substrate is preferably a glass woven fabric having a thickness of 200 µm or less and a mass of 250 g/m2 or less, and from the viewpoint of moisture absorption and heat resistance, a glass woven fabric surface-treated with a silane coupling agent such as epoxy silane or amino silane is preferable. From the viewpoint of electrical properties, a low-dielectric glass cloth made of glass fibers exhibiting a low relative permittivity and low dielectric tangent such as L-glass, NE-glass, or Q-glass is more preferable.

The low dielectric constant substrate is exemplified by a substrate having a dielectric constant of 5.0 or less (preferably 3.0 to 4.9). The low dielectric tangent substrate is exemplified by a substrate having a dielectric loss tangent of 0.006 or less (preferably 0.001 to 0.005). The relative dielectric constant and dielectric loss tangent are values measured at 10 GHz by a perturbation method cavity resonator.

＜＜Metal foil-clad laminated board＞＞

The metal foil-clad laminate of the present embodiment includes at least one layer formed by the prepreg of the present embodiment, and a metal foil arranged on one side or both sides of the layer formed by the prepreg. As a method for manufacturing the metal foil-clad laminate of the present embodiment, for example, a method can be exemplified in which at least one prepreg of the present embodiment is arranged (preferably two or more sheets are overlapped) and a metal foil is arranged on one side or both sides thereof and laminated and molded. More specifically, the laminate can be manufactured by arranging a metal foil such as copper or aluminum on one side or both sides of the prepreg and laminating and molding the laminate. The number of prepregs is preferably 1 to 10, more preferably 2 to 10, and still more preferably 2 to 9. The metal foil is not particularly limited as long as it is used as a material for a printed wiring board, and examples thereof include copper foils such as rolled copper foil and electrolytic copper foil. The thickness of the metal foil (preferably copper foil) is not particularly limited, and may be about 1.5 to 70 ㎛. In addition, when copper foil is used as the metal foil, it is preferable that the roughness Rz of the copper foil surface measured according to JIS B0601: 2013 is adjusted to 0.2 to 4.0 ㎛. By setting the roughness Rz of the copper foil surface to 0.2 ㎛ or more, the roughness of the copper foil surface becomes an appropriate size, and the copper foil peel strength tends to be further improved. On the other hand, by setting the roughness Rz of the copper foil surface to 4.0 ㎛ or less, the roughness of the copper foil surface becomes an appropriate size, and the dielectric tangent characteristics of the obtained cured product tends to be further improved. The roughness Rz of the copper foil surface is, from the viewpoint of reducing the dielectric tangent, more preferably 0.5 µm or more, further preferably 0.6 µm or more, particularly preferably 0.7 µm or more, and further preferably 3.5 µm or less, further preferably 3.0 µm or less, particularly preferably 2.0 µm or less.

As a method of lamination molding, a method commonly used when molding a laminated board and a multilayer board for a printed wiring board can be exemplified, and more specifically, a method of lamination molding using a multi-stage press machine, a multi-stage vacuum press machine, a continuous molding machine, an autoclave molding machine, etc. at a temperature of about 180 to 350°C, a heating time of about 100 to 300 minutes, and a surface pressure of about 20 to 100 kg/cm2 can be exemplified. In addition, a multilayer board can be obtained by combining the prepreg of the present embodiment and a separately manufactured inner layer wiring board and performing lamination molding. As a method for manufacturing a multilayer board, for example, a copper foil of about 35 μm is arranged on both sides of a single prepreg sheet of the present embodiment, and laminated and formed using the above-described molding method, then an inner layer circuit is formed, and this circuit is subjected to a blackening treatment to form an inner layer circuit board, and then the inner layer circuit board and the prepreg of the present embodiment are alternately arranged one sheet each, and furthermore, copper foil is arranged on the outermost layer, and laminated and formed under the above-described conditions, preferably in a vacuum, thereby manufacturing a multilayer board. The metal foil-clad laminate of the present embodiment can be suitably used as a printed wiring board.

As described above, the resin composition for electronic materials obtained by using the resin composition of the present embodiment (the resin composition comprising a combination of specific components) can have a cured product having excellent properties such as low dielectric properties (low dielectric constant, low dielectric tangent), moisture absorption and heat resistance, heat resistance, desmear resistance, metal foil peel strength, crack resistance, appearance of the cured product, and low thermal expansion properties.

＜＜Printed wiring board＞＞

The printed wiring board of the present embodiment is a printed wiring board including an insulating layer and a conductor layer arranged on the surface of the insulating layer, wherein the insulating layer includes at least one of a layer formed with the resin composition of the present embodiment and a layer formed with the prepreg of the present embodiment. Such a printed wiring board can be manufactured according to a conventional method, and the manufacturing method thereof is not particularly limited. Hereinafter, an example of a method for manufacturing a printed wiring board will be described. First, a metal foil-clad laminate such as the copper foil-clad laminate described above is prepared. Next, an etching process is performed on the surface of the metal foil-clad laminate to form an inner layer circuit, and an inner layer substrate is manufactured. The surface of the inner layer circuit of the inner layer substrate is subjected to surface treatment to increase the adhesive strength as necessary, and then the prepreg described above is overlapped on the surface of the inner layer circuit by a required number of layers, and further, a metal foil for the outer layer circuit is laminated on the outside thereof, and is heated and pressurized to integrally form the same. In this way, a multilayer laminate is manufactured in which an insulating layer formed of a cured product of a substrate and a resin composition is formed between the metal foil for the inner circuit and the outer circuit. Next, after the multilayer laminate is perforated for a through hole or a via hole, a plated metal film that electrically connects the inner circuit and the metal foil for the outer circuit is formed on the wall surface of the hole, and further, an etching process is performed on the metal foil for the outer circuit to form the outer circuit, thereby manufacturing a printed wiring board.

The printed wiring board obtained in the above manufacturing example has an insulating layer and a conductor layer formed on the surface of the insulating layer, and the insulating layer is configured to contain the resin composition of the present embodiment described above and/or a cured product thereof. That is, the prepreg of the present embodiment described above (for example, a prepreg formed of a substrate and the resin composition of the present embodiment impregnated or coated therewith), and the layer formed of the resin composition of the metal foil-clad laminate of the present embodiment described above become the insulating layer of the present embodiment.

In addition, the present embodiment also relates to a semiconductor device including the printed wiring board. Details of the semiconductor device can be referred to the description in paragraphs 0200 to 0202 of Japanese Patent Application Laid-Open No. 2021-021027, and these contents are incorporated herein.

In addition, it is preferable that the insulating layer formed of the cured product of the resin composition of the present embodiment have a small surface roughness after the roughening treatment of the insulating layer. Specifically, the arithmetic mean roughness Ra of the surface of the insulating layer after the roughening treatment is preferably 200 nm or less, more preferably 150 nm or less, and particularly preferably 100 nm or less. The lower limit of the arithmetic mean roughness Ra is not particularly limited, but may be, for example, 10 nm or more. The arithmetic mean roughness Ra of the surface of the insulating layer is measured using a non-contact surface roughness meter in VSI mode with a 50x lens.

The non-contact surface roughness meter used is WYKONT3300 manufactured by Vico Instruments.

＜＜Resin composite sheet＞＞

The resin composite sheet of the present embodiment comprises a support and a layer formed of the resin composition of the present embodiment arranged on the surface of the support. The resin composite sheet can be used as a build-up film or a dry film solder resist. The method for producing the resin composite sheet is not particularly limited, but for example, a method may be exemplified in which a solution of the resin composition of the present embodiment described above dissolved in a solvent is applied (coated) to a support and dried to obtain a resin composite sheet.

Examples of the support used here include, but are not limited to, a polyethylene film, a polypropylene film, a polycarbonate film, a polyethylene terephthalate film, an ethylene tetrafluoroethylene copolymer film, and a release film having a release agent applied to the surface of these films, an organic film substrate such as a polyimide film, a conductive foil such as a copper foil or an aluminum foil, a glass plate, a SUS (Steel Use Stainless) plate, an FRP (Fiber-Reinforced Plastics) plate, and the like.

As a coating method (coating method), for example, a method in which a solution prepared by dissolving the resin composition of the present embodiment in a solvent is applied onto a support using a bar coater, a die coater, a doctor blade, a baker applicator, or the like can be exemplified. In addition, after drying, a single-layer sheet can be obtained by peeling or etching the support from a resin composite sheet in which the support and the resin composition are laminated. In addition, a single-layer sheet can be obtained without using a support by supplying a solution prepared by dissolving the resin composition of the present embodiment in a solvent into a mold having a sheet-shaped cavity, drying it, and then molding it into a sheet shape.

In addition, in the production of the single-layer sheet or resin composite sheet of the present embodiment, the drying conditions when removing the solvent are not particularly limited, but at a low temperature, the solvent tends to remain in the resin composition, and at a high temperature, curing of the resin composition progresses, so a temperature of 20 to 200° C. for 1 to 90 minutes is preferable. In addition, the single-layer sheet or resin composite sheet can be used in an uncured state in which only the solvent has been dried, or can be used in a semi-cured (B-staged) state as necessary. In addition, the thickness of the resin layer in the single-layer sheet or resin composite sheet of the present embodiment can be adjusted by the concentration of the solution of the resin composition of the present embodiment used for coating (coating) and the coating thickness, and is not particularly limited, but generally, since the solvent tends to remain when drying when the coating thickness becomes thicker, it is preferable that it be 0.1 to 500 μm.

Example

The present invention will be described more specifically below with reference to examples. The materials, amounts used, ratios, processing contents, processing sequences, etc. shown in the examples below can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

If the measuring device used in the example is difficult to obtain due to discontinuation of production or other reasons, measurements can be made using another device with equivalent performance.

＜Measurement of weight average molecular weight and number average molecular weight＞

The weight average molecular weight (Mw) and number average molecular weight (Mn) of a polymer (va) having a structural unit represented by the following formula (V), a modified polyphenylene ether compound, etc., were measured by the gel permeation chromatography (GPC) method. A feed pump (LC-20AD manufactured by Shimadzu Corporation), a differential refractive index detector (RID-10A manufactured by Shimadzu Corporation), a GPC column (GPC KF-801, 802, 803, 804 manufactured by Showa Denko Kyokai), tetrahydrofuran as a solvent, a flow rate of 1.0 mL/min, a column temperature of 40°C, and a calibration curve using monodisperse polystyrene were used.

＜Synthesis Example 1 Synthesis of a polymer (va) having a constituent unit represented by formula (V)＞

2.25 mol (292.9 g) of divinylbenzene, 1.32 mol (172.0 g) of ethylvinylbenzene, 11.43 mol (1190.3 g) of styrene and 15.0 mol (1532.0 g) of n-propyl acetate were charged into a reactor, 600 mmol of diethyl ether complex of boron trifluoride was added at 70°C, and the mixture was reacted for 4 hours. After the polymerization reaction was stopped with an aqueous sodium bicarbonate solution, the oil layer was washed three times with pure water, and degassed under reduced pressure at 60°C to recover a polymer (va) having a structural unit represented by the formula (V). The obtained polymer (va) having a structural unit represented by the formula (V) was weighed, and it was confirmed that 860.8 g of a polymer (va) having a structural unit represented by the formula (V) was obtained.

The number average molecular weight Mn of the polymer (va) having the structural unit represented by the obtained formula (V) was 2,060, the weight average molecular weight Mw was 30,700, and the monodispersity Mw/Mn was 14.9. By performing ¹³ C-NMR and ¹ H-NMR analyses, resonance lines derived from each monomer unit used as a raw material were observed in the polymer (va) having the structural unit represented by the formula (V). Based on the NMR measurement results and the GC analysis results, the ratio of each monomer unit (the structural unit derived from each raw material) in the polymer (va) having the structural unit represented by the formula (V) was calculated as follows.

Composition unit derived from divinylbenzene: 20.9 mol% (24.3 mass%)

Composition unit derived from ethyl vinyl benzene: 9.1 mol% (10.7 mass%)

Composition unit derived from styrene: 70.0 mol% (65.0 mass%)

In addition, the composition unit having a residual vinyl group derived from divinylbenzene was 16.7 mol% (18.5 mass%).

＜Synthesis Example 2 Synthesis of modified polyphenylene ether compound＞

＜＜Synthesis of bifunctional phenylene ether oligomers＞＞

In a 12 L vertical reactor equipped with a stirring device, a thermometer, an air inlet tube, and a baffle, 9.36 g (42.1 mmol) of CuBr ₂ , 1.81 g (10.5 mmol) of N,N'-di-t-butylethylenediamine, 67.77 g (671.0 mmol) of n-butyldimethylamine, and 2,600 g of toluene were charged, stirred at a reaction temperature of 40° C., and 129.32 g (0.48 mol) of 2,2',3,3',5,5'-hexamethyl-(1,1'-biphenol)-4,4'-diol, 878.4 g (7.2 mol) of 2,6-dimethylphenol, 1.22 g (7.2 mmol) of N,N'-di-t-butylethylenediamine, A mixed solution of 26.35 g (260.9 mmol) of n-butyldimethylamine was added dropwise over 230 minutes while bubbling a mixed gas of nitrogen and air adjusted to an oxygen concentration of 8 vol% at a flow rate of 5.2 L/min, and stirring was performed. After completion of the dropping, 1,500 g of water in which 48.06 g (126.4 mmol) of sodium ethylenediamine tetraacetate was dissolved was added, and the reaction was stopped. The aqueous layer and the organic layer were separated, and the organic layer was washed with a 1 N aqueous hydrochloric acid solution and then with purified water. The obtained solution was concentrated to 50 mass% with an evaporator, and 1,981 g of a toluene solution of a difunctional phenylene ether oligomer (resin “A”) was obtained. The number average molecular weight of resin "A" converted to polystyrene by GPC method was 1,975, the weight average molecular weight converted to polystyrene by GPC method was 3,514, and the hydroxyl equivalent was 990.

＜＜Synthesis of modified polyphenylene ether compounds＞＞

Into a reactor equipped with a stirring device, a thermometer, and a reflux tube were charged 833.4 g of a toluene solution of resin "A", 76.7 g of vinylbenzyl chloride (manufactured by AGC Seimi Chemical Co., Ltd., "CMS-P"), 1,600 g of methylene chloride, 6.2 g of benzyldimethylamine, 199.5 g of purified water, and 83.6 g of a 30.5 mass% NaOH aqueous solution, and stirring was performed at a reaction temperature of 40°C. After stirring for 24 hours, the organic layer was washed with a 1 N hydrochloric acid aqueous solution and then with purified water. The obtained solution was concentrated in an evaporator, added dropwise into methanol to solidify, and the solid was recovered by filtration and dried in vacuum to obtain 450.1 g of a modified polyphenylene ether compound. The number average molecular weight of the modified polyphenylene ether compound as converted to polystyrene by GPC was 2,250, the weight average molecular weight as converted to polystyrene by GPC was 3,920, and the vinyl group equivalent was 1,189 g/vinyl group.

Example 1

31.0 parts by mass of a compound represented by a formula (M-2) wherein m = 0 (manufactured by Nippon Gunpyaku Kaisha, "MIR-5000"), 31.0 parts by mass of a polymer (va) having a structural unit represented by the formula (V) obtained in Synthesis Example 1, 3.0 parts by mass of 4-methylstyrene, 15.0 parts by mass of a thermoplastic elastomer (SBS, manufactured by JSR, TR2250), and 20.0 parts by mass of a phosphorus flame retardant (PX-200, manufactured by Daihachi Chemical Co., Ltd., 1,3-phenylenebis(2,6-disylenylphosphate)) were dissolved in methyl ethyl ketone and mixed, thereby obtaining a varnish. It should be noted that each addition amount described above represents a solid content amount.

＜Manufacture of test specimens of 0.8 mm thick hardened plate＞

A resin composition powder was obtained by evaporating and distilling the solvent from the obtained varnish. The resin composition powder was filled into a mold having a side length of 100 mm and a thickness of 0.8 mm, and copper foil having a thickness of 12 ㎛ (3EC-M2S-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) was placed on both surfaces, and a vacuum press was performed at a pressure of 30 kg/cm2 and a temperature of 220°C for 120 minutes to obtain a cured plate having a side length of 100 mm and a thickness of 0.8 mm.

Using the obtained hardened plate, the dielectric constant (Dk), dielectric loss tangent (Df), glass transition temperature (Tanδ), coefficient of thermal expansion (CTE), and desmear resistance were evaluated. The evaluation results are shown in Table 1.

＜Measurement method and evaluation method＞

(1) Dielectric constant (Dk) and dielectric loss tangent (Df)

After the copper foil on both sides of the obtained hardened plate was removed by etching, the sample for evaluation was downsized to 10 mm × 1 mm. The obtained sample for evaluation was dried at 120°C for 60 minutes, and the dielectric constant (Dk) and dielectric loss tangent (Df) after drying at 10 GHz were measured using a perturbation cavity resonator. The measurement temperature was 23°C.

The perturbation cavity resonator used was Agilent8722ES manufactured by Agilent Technologies.

Dielectric constant (Dk)

A: 2.50 or less

B: Over 2.50 and under 2.60

C: Over 2.60

Genetic tangent (Df)

A: less than 0.0023

B: 0.0023 or more and less than 0.0026

C: 0.0026 or higher

(2) Glass transition temperature (Tanδ)

The glass transition temperature was measured using a dynamic viscoelasticity measuring device on a sample downsized to 12.7 mm × 30 mm after the copper foil on both sides of the obtained cured plate was removed by etching, in accordance with JIS-K7244-4: 1999 (Plastics - Test methods for dynamic mechanical properties - Part 4: Tensile vibration - Non-resonant method) at an initial temperature of 30°C, an end temperature of 400°C, a heating rate of 5°C/min, a measurement frequency of 1 Hz, in a nitrogen atmosphere, and the temperature at which the loss tangent (Tanδ) obtained at that time became the maximum was taken as the glass transition temperature.

The dynamic viscoelasticity measuring device used was EXSTAR6000 DMS6100 manufactured by Seiko Instruments Co., Ltd.

It was evaluated as follows.

A: 250℃ or higher

B: 230℃ or higher but less than 250℃

C: less than 230℃

(3) Coefficient of linear thermal expansion (CTE)

For the obtained cured plate, the thermal expansion coefficient was measured by the TMA method (thermo-mechanical analysis) specified in JIS C 6481 5.19. Specifically, a sample in which the copper foil on both sides of the obtained cured plate was removed by etching and then downsized to 5 mm × 5 mm was heated from 30°C to 340°C at a rate of 10°C per minute, and the linear thermal expansion coefficient (CTE (Z)) in the direction perpendicular to the plane (unit: ppm/°C) at 30°C to 300°C was measured. ppm is the volume ratio. For other details, the above-mentioned JIS C 6481 5.19 is followed.

It was evaluated as follows.

A: 70 ppm/℃ or less

B: Over 70 ppm/℃ and under 80 ppm/℃

C: Over 80 ppm/℃

(4) Desmear resistance

After the copper foil on both sides of the obtained hardened plate was removed by etching, a downsized (50 mm × 50 mm) sample was used to perform the following immersion treatment. First, the obtained sample was immersed in a swelling solution (manufactured by Atotech Japan, Swelling Deep Securigant P) at 80°C for 10 minutes. Next, the immersed sample was immersed in a conditioning solution (manufactured by Atotech Japan, Concentrate Compact CP) at 80°C for 5 minutes. Next, the immersed sample was immersed in a neutralizing solution (manufactured by Atotech Japan, Reduction Conditioner Securigant P500) at 45°C for 10 minutes. The mass reduction rate (mass%) of the sample after performing this immersion treatment twice was measured.

It was evaluated as follows.

A: -4 mass% or more and -2 mass% or less

B: Other than the above

Comparative Example 1

In Example 1, the compound represented by the formula (M-2) (manufactured by Nippon Gunplaza Co., Ltd., “MIR-5000”) was changed to an equivalent amount of a maleimide compound having the following structure (manufactured by DIC Corporation, “NE-X-9470S”), and the same procedure was followed otherwise.

[Chemical Formula 49]

Comparative Example 2

In Example 1, the polymer (va) having a structural unit represented by formula (V) obtained in Synthesis Example 1 was changed to an equivalent amount of the modified polyphenylene ether compound obtained in Synthesis Example 2, and the same procedure was otherwise carried out.

Comparative Example 3

In Example 1, the compound represented by the formula (M-2) (manufactured by Nippon Chemical Co., Ltd., “MIR-5000”) was changed to an equivalent amount of a maleimide compound having the following structure (manufactured by Nippon Chemical Co., Ltd., “MIR-3000”), and the same procedure was followed otherwise.

[Chemical formula 50]

Claims (23)

A compound (M) represented by formula (M),
A resin composition comprising a polymer (V) having a structural unit represented by formula (V).

(In formula (M), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom, each R ^mx independently represents a methylene group, an ethylidene group, or a 2,2-propylidene group, and R ^my is a group selected from the following group (A). m represents an integer of 0 to 3, and n is an average value of the repetition number and represents 1.00 ≤ n ≤ 20.00.)
(Army (A))

(In group (A), R ^y is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group which may have a substituent, ny is each independently an integer of 0 to 3, and * is a bonding position with R ^mx .)

(In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.) In paragraph 1,
A resin composition, wherein the content of the compound (M) represented by the formula (M) is 1 to 90 parts by mass when the resin solid content in the resin composition is 100 parts by mass. In claim 1 or 2,
A resin composition, wherein the content of a polymer (V) having a structural unit represented by the formula (V) is 1 to 90 parts by mass, based on 100 parts by mass of the resin solid content in the resin composition. In claim 1 or 2,
A resin composition, wherein in the compound (M) represented by the above formula (M), n is 1.05 ≤ n ≤ 20.00. In claim 1 or 2,
A resin composition, wherein the compound (M) represented by the above formula (M) includes a compound represented by the formula (M-1).

(In formula (M-1), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with a halogen atom. m represents an integer of 0 to 3, and n represents the average value of the repetition number, 1.00 ≤ n ≤ 20.00.) In claim 1 or 2,
A resin composition, wherein the compound (M) represented by the above formula (M) includes a compound represented by the formula (M-2).

(In formula (M-2), R ^z each independently represents a hydrocarbon group having 1 to 10 carbon atoms. m represents an integer of 0 to 3, and n represents the average value of the repetition number, 1.00 ≤ n ≤ 20.00.) In claim 1 or 2,
A resin composition having a polymer (V) having a structural unit represented by the above formula (V) and having a weight average molecular weight of 3,000 to 130,000. In claim 1 or 2,
A resin composition having a polymer (V) having a structural unit represented by the above formula (V) and having a weight average molecular weight of 10,000 to 130,000. In claim 1 or 2,
Additionally, a resin composition comprising at least one other thermosetting compound (C) selected from the group consisting of a maleimide compound, an epoxy compound, a phenol compound, an oxetane resin, a benzoxazine compound, a compound containing a (meth)allyl group, and a polyphenylene ether compound containing two or more carbon-carbon unsaturated double bonds, other than the compound (M) represented by the above formula (M). In Article 9,
A resin composition, wherein the content of the other thermosetting compound (C) is 1 to 70 parts by mass when the resin solid content included in the resin composition is 100 parts by mass. In claim 1 or 2,
Additionally, a resin composition comprising a low molecular weight vinyl compound having a molecular weight of less than 1000 and further including one organic group including a carbon-carbon unsaturated bond in the molecule. In Article 11,
A resin composition comprising a low molecular weight vinyl compound having a molecular weight of less than 1000 and containing one organic group containing a carbon-carbon unsaturated bond in the molecule, at least one selected from the group consisting of a (meth)acrylic acid ester compound, an aromatic vinyl compound, a saturated fatty acid vinyl compound, a vinyl cyanide compound, an ethylenically unsaturated carboxylic acid, an ethylenically unsaturated carboxylic anhydride, an ethylenically unsaturated dicarboxylic acid monoalkyl ester, and an ethylenically unsaturated carboxylic acid amide. In claim 1 or 2,
Additionally, a resin composition comprising a filler (D). In Article 13,
A resin composition, wherein the content of the filler (D) in the resin composition is 10 to 1600 parts by mass with respect to 100 parts by mass of the resin solid content. In claim 1 or 2,
Additionally, a resin composition comprising a thermoplastic elastomer. In paragraph 1,
When the resin solid content in the above resin composition is 100 parts by mass, the content of the compound (M) represented by the above formula (M) is 1 to 90 parts by mass,
When the resin solid content in the above resin composition is 100 parts by mass, the content of the polymer (V) having the structural unit represented by the above formula (V) is 1 to 90 parts by mass,
In the compound (M) represented by the above formula (M), n is 1.05 ≤ n ≤ 20.00,
The compound (M) represented by the above formula (M) includes a compound represented by the formula (M-1),
The weight average molecular weight of the polymer (V) having the structural unit represented by the above formula (V) is 3,000 to 130,000,
Additionally, a resin composition comprising a thermoplastic elastomer.

(In formula (M-1), each R independently represents a hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with a halogen atom. m represents an integer of 0 to 3, and n represents the average value of the repetition number, 1.00 ≤ n ≤ 20.00.) In Article 16,
A resin composition having a polymer (V) having a structural unit represented by the above formula (V) and having a weight average molecular weight of 10,000 to 130,000. A cured product of the resin composition described in claim 1, claim 2, or claim 17. A prepreg formed from a substrate and a resin composition as described in claim 1, claim 2, or claim 17. A metal foil-clad laminate comprising at least one layer formed of the prepreg described in claim 19, and a metal foil disposed on one or both sides of the layer formed of the prepreg. A resin composite sheet comprising a support and a layer formed of the resin composition according to claim 1, claim 2 or claim 17, which is arranged on the surface of the support. A printed wiring board comprising an insulating layer and a conductor layer arranged on a surface of the insulating layer, wherein the insulating layer comprises a layer formed of a resin composition according to claim 1, claim 2, or claim 17. A semiconductor device comprising a printed wiring board as described in claim 22.