Thermosetting resin composition for forming wiring board, cured product, prepreg, and interlayer insulating film

Abstract

Provided is a thermosetting resin composition for forming a wiring board, the thermosetting resin containing: a polymer (A) having a structural unit represented by formula (1-1); and a copolymer (B) having a structural unit derived from ethylene or α-olefin, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from an aromatic polyfunctional vinyl compound. Also provided are a cured product, a prepreg, and an interlayer insulating film. The details of formula (1-1) are shown in the specification.

Description

Thermosetting resin composition for forming wiring board, cured product, prepreg and interlayer insulating film

[0001] The present invention relates to a thermosetting resin composition for forming a wiring board, a cured product, a prepreg, and an interlayer insulating film.

[0002] In recent years, in the information and communications field, various electronic devices, particularly mobile communication devices, have become capable of high-speed, large-capacity transmission. As the amount of information processed increases, packaging technologies, such as the high integration of semiconductor devices, high-density and multi-layer wiring, and high-frequency compatibility, are rapidly advancing. For this reason, printed wiring boards and other components used in various electronic devices are required to not only have high heat resistance, but also to have adhesion to high-density, fine wiring (e.g., copper), and to reduce signal transmission loss in order to increase the transmission speed of electrical signals, including those in the high-frequency band. To meet these requirements, materials with lower dielectric constants and dielectric loss tangents are needed as substrate materials for the insulating layers used in wiring boards.

[0003] Known materials for this trend toward higher frequencies include polyolefin resins, styrene resins, fluororesins, polyphenylene ether resins (PPE), vinylbenzyl ether resins, and compositions using polyphenylene ether resins. Among these, PPE has excellent high-frequency characteristics (dielectric properties), such as a low dielectric constant and low loss due to dielectric tangent (dielectric loss), and is widely used as an insulating material for printed wiring boards in electronic devices such as mobile devices that use high frequencies. Meanwhile, molding materials such as substrate materials are required to not only have excellent low dielectric properties but also excellent heat resistance. For this reason, it has been considered to enhance heat resistance by modifying the resin contained in the substrate material (e.g., by introducing vinyl groups) so that it can be polymerized with a curing agent or the like. For example, Patent Document 1 describes a polyphenylene ether compound containing a polyphenylene ether having a polyphenylene ether moiety in its molecular structure, an ethenylbenzyl group or the like at the molecular end, and a number-average molecular weight of 1,000 to 7,000, and a cross-linking curing agent. Furthermore, for example, Patent Document 2 describes a resin composition containing an acenaphthylene compound and a polyphenylene ether having ethenylbenzyl groups at the molecular terminals in order to further enhance the heat resistance of the polyphenylene ether.

[0004] International Publication No. WO 2004 / 067634 International Publication No. WO 2020 / 017399

[0005] Electronic materials are required to have not only a low dielectric constant and a low dielectric loss tangent (hereinafter also referred to as "low dielectric loss tangent"), but also properties such as heat resistance and adhesiveness. The compositions and laminates disclosed in Patent Documents 1 and 2 do not all have a good balance of heat resistance, adhesion to copper wiring, and high-frequency properties, and further improvements in the low dielectric loss tangent of the compositions and laminates are required to accommodate the high frequencies of information and communication devices intended for high-speed, large-capacity information transmission.

[0006] The problem to be solved by one embodiment of the present invention is to provide a thermosetting resin composition for forming wiring substrates, which provides a cured product having a low dielectric loss tangent, an excellent balance of adhesion and heat resistance. The problem to be solved by another embodiment of the present invention is to provide a cured product, a prepreg and an interlayer insulating film having a low dielectric loss tangent, excellent heat resistance and peelability.

[0007] Means for solving the above problems include the following aspects: <1> A thermosetting resin composition for forming a wiring substrate, comprising: a polymer (A) having a structural unit represented by the following formula (1-1), and a copolymer (B) having a structural unit derived from ethylene or an α-olefin, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from an aromatic polyfunctional vinyl compound.

[0008]

[0009] In formula (1-1), R a1 is a divalent group represented by the following formula (2), and R a2 is expressed by the following formula (R a2 −1), (R a2 −2) and (R a2 -3) is a divalent group represented by one selected from the following:

[0010]

[0011] In formula (2), Ar a1 and Ar a2 are each independently an unsubstituted or substituted aromatic hydrocarbon group, and L is a single bond, —O—, —S—, —N(R 8 )-, -C(O)-, -C(O)-O-, -C(O)-NH-, -S(O)-, -S(O)2-, -P(O)- or a divalent organic group, 8 is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms; y is an integer of 0 to 5; when y is 2 or more, a plurality of Ar a1 and L are the same or different, R a6 and R a7 are each independently a single bond, a methylene group, or an alkylene group having 2 to 4 carbon atoms.

[0012]

[0013] Formula (R a2 -1) to (R a2 -3) Medium, R 1 are each independently a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a nitro group, a cyano group, a primary amino group, a tertiary amino group, or a salt of a primary amino group, a tertiary amino group, and each n is independently an integer of 0 to 2. When n is 2, multiple R 1are the same or different and are combined with each other to form a ring structure having 5 to 10 ring members, together with the carbon atoms to which they are bonded. <2> The thermosetting resin composition for forming a wiring substrate according to <1>, wherein the number average molecular weight of the copolymer (B) is 500 or more and 100,000 or less. <3> The thermosetting resin composition for forming a wiring substrate according to <1> or <2>, wherein the aromatic vinyl compound in the copolymer (B) is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of structural units derived from the aromatic vinyl compound is more than 0 mass% and 70 mass% or less when the mass of all structural units constituting the copolymer (B) is 100 mass%. <4> The thermosetting resin composition for forming a wiring substrate according to any one of <1> to <3>, wherein the α-olefin in the copolymer (B) is one or more α-olefins selected from α-olefins having from 3 to 20 carbon atoms, and the total of the structural units derived from the ethylene or α-olefin, the structural units derived from an aromatic vinyl compound, and the structural units derived from an aromatic polyfunctional vinyl compound is 100% by mass based on the mass of all structural units in the copolymer (B). <5> The thermosetting resin composition for forming a wiring substrate according to any one of <1> to <4>, further comprising a curable compound (C) and an organic solvent (E). <6> The thermosetting resin composition for forming a wiring substrate according to <5>, wherein the curable compound (C) is at least one compound selected from the group consisting of vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds. <7> The thermosetting resin composition for forming a wiring board according to any one of <1> to <6>, further comprising a polymerization initiator (D). <8> The thermosetting resin composition for forming a wiring board according to any one of <1> to <7>, further comprising a filler (F). <9> A cured product comprising the thermosetting resin composition for forming a wiring board according to any one of <1> to <8>. <10> A prepreg obtained by impregnating a fibrous base material with the thermosetting resin composition for forming a wiring board according to any one of <1> to <8>. <11> A copper-clad laminate which is a laminate of the prepreg according to <10> and a copper substrate.<12> An interlayer insulating film comprising the thermosetting resin composition for forming a wiring board according to any one of <1> to <8>.

[0014] According to one embodiment of the present invention, there is provided a thermosetting resin composition for forming a wiring board, which provides a cured product with a low dielectric loss tangent, excellent adhesion, and heat resistance. Also, according to one embodiment of the present invention, there are provided a cured product, a prepreg, and an interlayer insulating film, which provide a good balance of a low dielectric loss tangent, adhesion, and heat resistance.

[0015] Preferred embodiments of the present invention are described in detail below. It should be understood that the present invention is not limited to the embodiments described below and includes various modifications implemented within the scope of the present invention. In this specification, a numerical range described using "to" includes the numerical values ​​before and after "to" as the lower and upper limits. In this specification, the term "polymer" encompasses homopolymers and copolymers. In this specification, "to" indicating a numerical range means that the units described before or after it represent the same unit unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, the term "α-olefin" does not include ethylene. In this specification, a polymer, composition, cured product, laminate, or electronic component according to one embodiment of the present invention is described in detail below.

[0016] <Thermosetting Resin Composition for Forming Wiring Boards> The thermosetting resin composition for forming wiring boards according to the present invention (hereinafter sometimes simply referred to as the "thermosetting resin composition") contains a polymer (A) having a structural unit represented by formula (1-1), and a copolymer (B) having a structural unit derived from ethylene or an α-olefin, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from an aromatic polyfunctional vinyl compound. Because the thermosetting resin composition has the above-described structure, the resulting cured product exhibits an excellent balance of low dielectric tangent, adhesion, and heat resistance. The reason for this is not clear, but the following mechanism is presumed. Since the thermosetting resin composition contains the polymer (A) having a specific structure and the copolymer (B) having a specific structural unit, the compatibility of the polymer (A) and the copolymer (B) is good, and the cured product obtained from the thermosetting resin composition has heat resistance due to the structure of the polymer (A). Furthermore, since the inclusion of the polymer (A) and the copolymer (B) results in an excellent low dielectric tangent, it is presumed that the cured product obtained from the thermosetting resin composition has an excellent balance of low dielectric tangent, adhesiveness, and heat resistance. Below, each component of the thermosetting resin composition will be described in detail.

[0017] <<Polymer (A)>> The polymer (A) has a structural unit represented by formula (1-1).

[0018]

[0019] In formula (1-1), R a1 is a divalent group represented by the following formula (2), and R a2 is expressed by the following formula (R a2 −1), (R a2 −2) and (R a2 -3) is a divalent group represented by one selected from the following:

[0020]

[0021] In formula (2), Ar a1 and Ar a2 are each independently an unsubstituted or substituted aromatic hydrocarbon group, and L is a single bond, —O—, —S—, —N(R 8)-, -C(O)-, -C(O)-O-, -C(O)-NH-, -S(O)-, -S(O)2-, -P(O)- or a divalent organic group, 8 is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms; y is an integer of 0 to 5; when y is 2 or more, a plurality of Ar a1 and L are the same or different, R a6 and R a7 are each independently a single bond, a methylene group, or an alkylene group having 2 to 4 carbon atoms.

[0022] [Ar a1 and Ar a2 〕 Ar a1 and Ar a2 The unsubstituted or substituted aromatic hydrocarbon groups represented by the following formula (I) are each independently preferably aromatic hydrocarbon groups having 6 to 30 carbon atoms, more preferably a phenyl group, a naphthyl group, or an anthryl group, and particularly preferably a phenyl group or a naphthyl group.

[0023] The number of substituents possessed by the substituted aromatic hydrocarbon group is preferably 0 to 8, more preferably 0 to 4, and even more preferably 0 to 2. When the number of substituents is within the above range, the polymerization reaction is stabilized, and a polymer having a constant molecular weight (narrow molecular weight distribution) is easily obtained, and a thermosetting resin composition using such a polymer makes it easy to control the curability of the cured product and the fluidity during pressing when molding a prepreg or laminate.

[0024] The substituent on the aromatic hydrocarbon group is not particularly limited and includes, for example, an allyl group, a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, a nitro group, a cyano group, a carboxy group, a sulfonic acid group, a phosphonic acid group, a phosphate group, a hydroxy group, a primary to tertiary amino group, a salt of a carboxy group, a salt of a sulfonic acid group, a salt of a phosphonic acid group, a salt of a phosphate group, a salt of a hydroxy group, and a salt of a primary to tertiary amino group. Of these, the monovalent hydrocarbon group having 1 to 20 carbon atoms and an allyl group are preferred as the substituent on the aromatic hydrocarbon group.

[0025] The halogen atom is not particularly limited, and examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0026] The monovalent hydrocarbon group having 1 to 20 carbon atoms is not particularly limited and may be, for example, a linear or cyclic hydrocarbon group. Examples of cyclic hydrocarbon groups include alicyclic hydrocarbon groups and aromatic hydrocarbon groups. The cyclic hydrocarbon group may be a monocyclic ring or a condensed ring (polycyclic ring).

[0027] Examples of the chain hydrocarbon group include linear or branched, saturated or unsaturated hydrocarbon groups, such as alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and n-pentyl; alkenyl groups such as ethenyl, propenyl, butenyl, and pentenyl; and alkynyl groups such as ethynyl, propynyl, butynyl, and pentynyl.

[0028] Examples of the alicyclic hydrocarbon group include monocyclic cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group; polycyclic cycloalkyl groups such as a norbornyl group and an adamantyl group; monocyclic cycloalkenyl groups such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, and a cyclohexenyl group; and polycyclic cycloalkenyl groups such as a norbornenyl group.

[0029] The aromatic hydrocarbon group is not particularly limited, and examples thereof include aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthryl; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, and naphthylmethyl.

[0030] Examples of the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms include groups in which some or all of the hydrogen atoms of the monovalent hydrocarbon group having 1 to 20 carbon atoms have been substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0031] Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and an octyloxy group.

[0032] Examples of the alkylthio group having 1 to 20 carbon atoms include a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, a butylthio group, a pentylthio group, a hexylthio group, and an octylthio group.

[0033] When the amino group is a secondary amino group or a tertiary amino group, the substituent (R) in the secondary amino group (-NHR) and the tertiary amino group (-NR2) is not particularly limited, and examples of the substituent (R) include monovalent hydrocarbon groups having 1 to 20 carbon atoms. Specific examples include the groups exemplified as substituents in the unsubstituted nitrogen-containing heteroaromatic ring described below.

[0034] The cations constituting the cationic moieties in the salts of the carboxyl group, the salts of the sulfonic acid group, the salts of the phosphonic acid group, the salts of the phosphoric acid group, and the salts of the hydroxyl group are not particularly limited, and include Na + The anion constituting the anion moiety in the salt of the amino group is not particularly limited, and examples thereof include Cl. - Examples of known anions include:

[0035] In view of the fact that a cured product with a high crosslink density can be easily obtained, a1 and Ar a2 may each independently be an aromatic hydrocarbon group having an allyl group.

[0036] [L] The divalent organic group for L is preferably a divalent organic group having 1 to 20 carbon atoms, such as a methylene group, an alkylene group having 2 to 20 carbon atoms, a halogenated methylene group, a halogenated alkylene group having 2 to 20 carbon atoms, a divalent cardo structure, or a group represented by the following formula (L1):

[0037]

[0038] In formula (L1), R cis an unsubstituted or substituted divalent alicyclic hydrocarbon group having 5 to 30 ring members.

[0039] Examples of the alkylene group having 2 to 20 carbon atoms for L include an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, a sec-butylene group, a neopentylene group, a 4-methyl-pentane-2,2-diyl group, a nonane-1,9-diyl group, and a decane-1,1-diyl group.

[0040] Examples of the halogenated methylene group for L include groups in which some or all of the hydrogen atoms of a methylene group have been substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0041] Examples of the halogenated alkylene group having 2 to 20 carbon atoms for L include groups in which some or all of the hydrogen atoms of the alkylene group having 2 to 20 carbon atoms have been substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0042] Examples of the divalent cardo structure in L include a divalent group derived from fluorene represented by the following formula (L2) (i.e., a group obtained by removing two hydrogen atoms from a compound having a fluorene skeleton).

[0043]

[0044] In formula (L2), R8 and R9 each independently represent a hydrogen atom, a fluorine atom, or a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, and k each independently represents an integer of 0 to 4.

[0045] Examples of the divalent cardo structure include structures derived from compounds represented by the following formula:

[0046]

[0047] R in formula (L1) cExamples of the unsubstituted or substituted divalent alicyclic hydrocarbon group having 5 to 30 ring members represented by the formula (I) include an unsubstituted or substituted monocyclic alicyclic hydrocarbon group having 5 to 15 ring members, an unsubstituted or substituted monocyclic fluorinated alicyclic hydrocarbon group having 5 to 15 ring members, an unsubstituted or substituted polycyclic alicyclic hydrocarbon group having 7 to 30 ring members, and an unsubstituted or substituted polycyclic fluorinated alicyclic hydrocarbon group having 7 to 30 ring members.

[0048] Examples of the unsubstituted or substituted monocyclic alicyclic hydrocarbon group having 5 to 15 ring members include a cyclopentane-1,1-diyl group, a cyclohexane-1,1-diyl group, a 3,3,5-trimethylcyclohexane-1,1-diyl group, a cyclopentene-3,3-diyl group, a cyclohexene-3,3-diyl group, a cyclooctane-1,1-diyl group, a cyclodecane-1,1-diyl group, a cyclododecane-1,1-diyl group, and groups in which some or all of the hydrogen atoms of these groups have been substituted with a monovalent chain hydrocarbon group having 1 to 20 carbon atoms.

[0049] Examples of the unsubstituted or substituted monocyclic fluorinated alicyclic hydrocarbon group having 5 to 15 ring members include groups in which some or all of the hydrogen atoms of the groups exemplified as the monocyclic alicyclic hydrocarbon group having 5 to 15 ring members have been substituted with fluorine atoms.

[0050] Examples of the unsubstituted or substituted polycyclic alicyclic hydrocarbon group having 7 to 30 ring members include norbornane, norbornene, adamantane, tricyclo[5.2.1.0 2,6 ]decane, pinane, camphane, decalin, nortricyclane, perhydroanthracene, perhydroazulene, cyclopentanohydrophenanthrene, bicyclo[2.2.2]-2-octene, or other polycyclic alicyclic hydrocarbons by removing two hydrogen atoms bonded to one carbon atom; and groups in which some or all of the hydrogen atoms of these groups have been substituted with monovalent chain hydrocarbon groups having 1 to 20 carbon atoms.

[0051] Examples of the unsubstituted or substituted fluorinated polycyclic hydrocarbon group having 7 to 30 ring members include groups in which some or all of the hydrogen atoms of the groups exemplified as the polycyclic alicyclic hydrocarbon group having 7 to 30 ring members have been substituted with fluorine atoms.

[0052] -N(R 8 )-R in 8 is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms and the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms include the above-mentioned Ar a1 and Ar a2 Examples of the monovalent hydrocarbon groups having 1 to 20 carbon atoms and the monovalent halogenated hydrocarbon groups having 1 to 20 carbon atoms are given above.

[0053] From the viewpoint of the structural stability of the polymer (A), L is preferably a single bond, —O—, —S—, —C(O)—, —S(O)—, —S(O)2-, —C(O)-NH—, —C(O)-O—, a methylene group, an alkylene group having 2 to 5 carbon atoms, the above formula (L1), a halogenated methylene group, a halogenated alkylene group having 2 to 10 carbon atoms, or a divalent cardo structure.

[0054] [y] In formula (2), y is an integer of 0 to 5. From the viewpoint of the structural stability of the polymer (A), y is preferably an integer of 0 to 4, and more preferably an integer of 0 to 3.

[0055] [R a6 and R a7 ] In formula (2), R a6 and R a7 are each independently a single bond, a methylene group, or an alkylene group having 2 to 4 carbon atoms. Examples of the alkylene group having 2 to 4 carbon atoms include an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, and a sec-butylene group. a6 and R a7 are each independently preferably a single bond, a methylene group, or an ethylene group, from the viewpoint of enabling the synthesis of polymer (A) with good polymerization reactivity.

[0056] R in formula (1-1) a1Examples of the monomers that can be used as raw materials for the moiety containing the formula (2) (i.e., the divalent group represented by formula (2)) include dihydroxyphenyl compounds such as hydroquinone, resorcinol, catechol, and phenylhydroquinone; 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxy-3-phenylphenyl)fluorene, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-allylphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3-phenylphenyl)propane, 4,4'-(1,3-dimethylbutylidene)bisphenol, and 1,1-bis(4 bisphenol compounds such as 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene, 4,4'-cyclododecylidenebisphenol, and 4,4'-decylidenebisphenol; and diol compounds such as Priplast 1901, 1838, 3186, 3192, 3197, and 3199 (manufactured by Croda Japan Co., Ltd.). These monomers may be used alone or in combination of two or more.

[0057] <R a2 > R a2 is expressed by the following formula (R a2 −1), (R a2 −2) and (R a2 -3) is a divalent group represented by one selected from the following:

[0058]

[0059] Formula (R a2 -1) to (R a2 -3) Medium, R 1 are each independently a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a nitro group, a cyano group, a primary amino group, a tertiary amino group, or a salt of a primary amino group, a tertiary amino group, and each n is independently an integer of 0 to 2. When n is 2, multiple R 1 are the same or different and are part of a ring structure having 5 to 10 ring members that are joined together with the carbon atoms to which they are attached.

[0060] The above formula (R a2 -1) to (R a2 -3) R in 1 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0061] The above formula (R a2 -1) to (R a2 -3) R in 1 Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the formula (I) include a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.

[0062] Examples of the chain hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group; alkenyl groups such as an ethenyl group, a propenyl group, a butenyl group, and a pentenyl group; and alkynyl groups such as an ethynyl group, a propynyl group, a butynyl group, and a pentynyl group.

[0063] Examples of the alicyclic hydrocarbon group include monocyclic cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group; polycyclic cycloalkyl groups such as a norbornyl group and an adamantyl group; monocyclic cycloalkenyl groups such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, and a cyclohexenyl group; and polycyclic cycloalkenyl groups such as a norbornenyl group.

[0064] Examples of the aromatic hydrocarbon group include aryl groups such as phenyl, tolyl, xylyl, naphthyl and anthryl groups; and aralkyl groups such as benzyl, phenethyl, phenylpropyl and naphthylmethyl groups.

[0065] R 1 Examples of the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms represented by the formula (I) include the above-mentioned R 1 and groups in which some or all of the hydrogen atoms of the monovalent hydrocarbon groups having 1 to 20 carbon atoms exemplified as the group represented by the formula (I) are substituted with halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0066] R 1 From the viewpoint of improving the polymerization reactivity, n is preferably a halogen atom, a monovalent hydrocarbon group having 1 to 3 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 3 carbon atoms, a nitro group, or a cyano group, and more preferably a fluorine atom, a chlorine atom, a methyl group, a nitro group, or a cyano group. From the same viewpoint, n is preferably 0 or 1, and more preferably 0.

[0067] Formula (R a2 −1), (R a2 −2) and (R a2 In the divalent group represented by one kind selected from the group consisting of aryl, aryloxy ...

[0068] In addition, from the viewpoint of improving the polymerization reactivity and improving the solubility in various organic solvents, R a2 As the compound, a compound having a pyrimidine skeleton represented by the above formula (R a2 -2) is preferred.

[0069] <<Terminal Group>> The polymer (A) may have a terminal group Y represented by the following formula (a) at the end of the structural unit represented by formula (1-1).

[0070]

[0071] In formula (a), Y represents a group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms, an unsubstituted or substituted aromatic hydrocarbon group having 6 to 50 carbon atoms, an unsubstituted or substituted aliphatic hydrocarbon group having 6 to 50 carbon atoms, or an unsubstituted nitrogen-containing heteroaromatic ring, and when the aromatic hydrocarbon group or the aliphatic hydrocarbon group has a substituent, the substituent is a group other than a hydroxy group.

[0072] When the terminal group Y is bonded to the main chain terminal of the polymer (A), a partial structure represented by the following formula (a1) or (a2) is formed at the terminal portion of the polymer (A). In this case, the terminal group Y is represented by R a1 and R a2 The end of the a1 , Ar a2 and R a2 is a group different from the group constituting the substituent in

[0073]

[0074] In formula (a1) and formula (a2), Y has the same meaning as Y represented by formula (a), and R a1 and R a2 is R in the formula (1-1). a1 and R a2 is synonymous with.

[0075] Specific examples of the polymer (A) having the terminal group Y represented by formula (a) include polymers represented by the following formula (3) or (4): Here, the "main chain" refers to the relatively longest bonding chain in the polymer.

[0076]

[0077] In the above formulas (3) and (4), R a1 and R a2 are each independently R in the above formula (1-1). a1 and R a2 has the same meaning as Y in formula (a), and preferred embodiments are also the same. Y has the same meaning as Y in formula (a), and preferred embodiments are also the same. n is an integer of 0 to 100, and more preferably 2 to 30.

[0078] From the viewpoint of improving the dielectric properties, the terminal group Y is preferably an aromatic or aliphatic hydrocarbon group or a nitrogen-containing heteroaromatic ring group, which have small polarization. When the terminal group Y is a group containing an ethylenically unsaturated double bond, the crosslink density is improved, and therefore the resin composition has excellent curability and the resulting cured product has excellent heat resistance.

[0079] Examples of the group having 3 to 50 carbon atoms and containing an ethylenically unsaturated double bond, represented by Y, include aromatic ring-containing groups such as a 3-isopropenylphenyl group, a 4-isopropenylphenyl group, a 2-allylphenyl group, a 2-methoxy-4-allylphenyl group, a 4-(1-propenyl)-2-methoxyphenyl group, a 4-vinylbenzyl group, a 3-vinylbenzyl group, and a 2-vinylbenzyl group, an allyl group, an acrylic group, and a methacrylic group.

[0080] Examples of the aromatic hydrocarbon group having 6 to 50 carbon atoms represented by Y include aryl groups such as a phenyl group, a biphenyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group; and aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, and a naphthylmethyl group.

[0081] Examples of the aliphatic hydrocarbon group having 6 to 50 carbon atoms represented by Y include monocyclic cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group; polycyclic cycloalkyl groups such as a norbornyl group and an adamantyl group; monocyclic cycloalkenyl groups such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, and a cyclohexenyl group; and polycyclic cycloalkenyl groups such as a norbornenyl group.

[0082] Examples of the unsubstituted nitrogen-containing heteroaromatic ring represented by Y include a pyrrole ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a phthalazine ring, a quinazoline ring, a naphthyridine ring, a carbazole ring, an acridine ring, and a phenazine ring. Of these, a pyrimidine ring is preferred.

[0083] Examples of substituents in the unsubstituted or substituted aromatic hydrocarbon group having 6 to 50 carbon atoms, the unsubstituted or substituted aliphatic hydrocarbon group having 6 to 50 carbon atoms, and the unsubstituted nitrogen-containing heteroaromatic ring include groups other than a hydroxy group. The substituents are not particularly limited, but examples include an allyl group, a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, a nitro group, a cyano group, a carboxy group, a sulfonic acid group, a phosphonic acid group, a phosphate group, a primary to tertiary amino group, a salt of a carboxy group, a salt of a sulfonic acid group, a salt of a phosphonic acid group, a salt of a phosphate group, and a salt of a primary to tertiary amino group. Of these, an allyl group is preferred.

[0084] As a method for forming a polymer in which the terminals of the polymer (A) are capped with the terminal group Y, a1 or R a2 In addition to a monomer that forms the above, at least one monomer for forming the terminal group Y selected from the group consisting of a monohydric phenol compound, a monohydric amine compound, a monohydric thiol compound, a monohydric aliphatic halide, a monohydric acid halide, and a monohydric acid anhydride is reacted as a raw material. Examples of the method for synthesizing the polymer (A) containing the terminal group Y, which is a group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms, include a method of reacting a monomer that forms the above, a1 The monomers that are the raw materials for the part containing R a2 In order to avoid gelation due to reaction between ethylenically unsaturated double bonds when polymerizing with the monomer that is the raw material for the portion containing R a1 The monomers that are the raw materials for the part containing R a2 After polymerizing the monomer that is the raw material for the portion containing the group Y, the monomer for forming the terminal group Y may be reacted.

[0085] Examples of the monomer for forming the terminal group Y include monohydric phenol compounds such as ter-butylphenol, nonylphenol, 4-isopropenylphenol, 4-vinylphenol, 2-allylphenol, isoeugenol, tocotrienol, α-tocophenol, 4-hydroxyphenylmaleimide, and 2-phenylphenol; monovalent amine compounds such as 4-hexylaniline and diallylamine; monovalent thiol compounds such as 1-octanethiol; monovalent aliphatic halides such as allyl chloride, 4-(chloromethyl)styrene, and 3-(chloromethyl)styrene; monovalent acid halides such as acryl chloride, methacryl chloride, crotonoyl chloride, and cinnamoyl chloride; and monovalent acid anhydrides such as acrylic anhydride, crotonic anhydride, and methacrylic anhydride. The monomer for forming the terminal group Y may be used alone or in combination of two or more.

[0086] The polymer (A) may contain a structural unit represented by the following formula (1-2).

[0087]

[0088] In formula (1-2), R a2 is the above formula (R a2 −1), (R a2 −2) and (R a2 -3), and R 12 each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group, R 13 represents a hydrocarbon group having 1 to 20 carbon atoms, m represents an integer of 1 to 6, and ** represents a bond to another structural unit in the polymer (A).

[0089] The above formula (1-2) can be expressed by the following formula (1-2a).

[0090]

[0091] In the formula (1-2a), R a2 and R 12 are the same as those in the formula (1-2). 13x is two R 12In addition, it represents a hydrocarbon group having 1 to 20 carbon atoms to which at least one group represented by the following formula (1-2b) is bonded.

[0092]

[0093] In the formula (1-2b), * represents the R 13x represents a bond to another structural unit in the polymer (A), and R 12 is R in the formula (1-2). 12 is synonymous with.

[0094] [R 12 〕 R 12 The unsubstituted aromatic hydrocarbon group (arylene group) in the formula (I) may be a single ring or a fused ring. The number of carbon atoms in the unsubstituted aromatic hydrocarbon group is preferably 6 to 20, and more preferably 6 to 18. Examples of aromatic hydrocarbon groups include a phenylene group, a naphthylene group, and an anthrylene group.

[0095] R 12 The substituent in the substituted aromatic hydrocarbon group in the formula (I) is not particularly limited, and examples thereof include an allyl group, a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, a nitro group, a cyano group, a carboxy group, a sulfonic acid group, a phosphonic acid group, a phosphate group, a hydroxy group, a primary to tertiary amino group, and salts thereof.

[0096] R in the formula (1-2) or (1-2a) 12 are preferably each independently a group represented by the following formula (5), from the viewpoint of improving the glass transition temperature (Tg) of the polymer (A). A bond represented by a straight line spanning a side of a ring structure represents the substitution of any hydrogen atom in the ring structure. A bond represented by a straight line spanning multiple ring structures represents the substitution of any hydrogen atom in any of the ring structures.

[0097]

[0098] In the formula (5), R51 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms; n 52 represents an integer of 0 to 4, n 53 represents an integer of 0 to 2, and * represents R 13 or R in formula (1-2a) 13x represents a bond to O in formula (1-2) or formula (1-2a), and *** represents a bond to O in formula (1-2).

[0099] n 52 preferably represents an integer of 1 to 3, more preferably 1 or 2. 53 preferably represents 0 or 1, and more preferably 1.

[0100] Moreover, from the viewpoint of maintaining a low dielectric constant and a low dielectric dissipation factor and improving heat resistance (for example, Tg of the polymer (A)), the group represented by the formula (5) is preferably a group represented by the following formula (5-1) or (5-2):

[0101]

[0102] In the formula (5-1) and the formula (5-2), R 51 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms; R 52 represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms; n 53 represents an integer of 0 to 2, and n 54 represents an integer of 0 to 3, n 55 represents an integer of 0 to 2, and * represents R 13 represents a bond to the oxygen atom in formula (1-2) or formula (1-2a).

[0103] The R 51 and R 52The alkyl group having 1 to 10 carbon atoms in the formula (I) may be linear or branched. The alkyl group having 1 to 10 carbon atoms is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group.

[0104] The R 51 and R 52 The alkoxy group having 1 to 10 carbon atoms in the formula (I) is preferably an alkoxy group having 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and an octyloxy group.

[0105] The R 51 and R 52 The cycloalkyl group having 3 to 10 carbon atoms in the formula (I) is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

[0106] n 53 is n in formula (5) 53 The same applies to the preferred embodiments. 54 represents an integer of 0 to 3, preferably an integer of 0 to 2, 55 represents an integer of 0 to 2, preferably 0 or 1.

[0107] [R 13 and R 13x 〕 R 13 represents a group that introduces a branched structure into the structural unit represented by the formula (1-2). 13 and R 13x The hydrocarbon group having 1 to 20 carbon atoms in the formula (I) may be a linear or branched hydrocarbon group having 1 to 20 carbon atoms, a cyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof. 13 and R 13xPreferably, the hydrocarbon group has a structure formed by a tertiary carbon or a quaternary carbon in the above. When the hydrocarbon group is linear or branched, it is preferably a linear or branched hydrocarbon group having 1 to 10 carbon atoms, more preferably a linear or branched hydrocarbon group having 1 to 6 carbon atoms, and even more preferably a linear or branched hydrocarbon group having 1 to 4 carbon atoms. The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group. The alicyclic hydrocarbon group is preferably an alicyclic hydrocarbon group having 3 to 10 carbon atoms, more preferably an alicyclic hydrocarbon group having 3 to 8 carbon atoms, and even more preferably an alicyclic hydrocarbon group having 3 to 6 carbon atoms. The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, and more preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms.

[0108] R 13 is -(L-Z)n Z In the above formula, L represents a single bond or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, Z represents a linear or branched hydrocarbon group having 1 to 10 carbon atoms, and n Z represents 1 or 2. The alicyclic hydrocarbon group of 3 to 10 carbon atoms for L is preferably an alicyclic hydrocarbon group of 3 to 6 carbon atoms. The linear or branched hydrocarbon group of 1 to 10 carbon atoms for Z is preferably a linear or branched hydrocarbon group of 1 to 6 carbon atoms, more preferably a linear or branched hydrocarbon group of 1 to 4 carbon atoms.

[0109] The symbol ** in the formula (1-2) represents a bond to another structural unit in the polymer (A). The other structural unit in the polymer (A) may be a structural unit represented by another formula (1-2), a structural unit represented by the formula (1-1), the terminal group Y, or another structural unit described below. When the symbol ** in the structural unit (1-2) represented by the formula (1-2) in the polymer (A) represents a bond to another structural unit represented by the formula (1-2) or a structural unit represented by the formula (1-1), the symbol ** represents a bond to R in the structural unit represented by the formula (1-2) and the structural unit represented by the formula (1-1), 2aIt bonds to , but does not bond to O (oxygen atom).

[0110] Examples of the structural unit represented by formula (1-2) or formula (1-2a) include, but are not limited to, structural units having the following partial structures:

[0111]

[0112] [Method for forming a structural unit represented by formula (1-2) or formula (1-2a)] The structural unit represented by formula (1-2) or formula (1-2a) can be formed by a method comprising: forming a structural unit represented by formula (1-2) by cleaving a portion (-R 12 -R 13 (R 12 -O-**)m-R 12 -) or the portion sandwiched between two oxygen atoms in formula (1-2a) (-R 12 -R 13x -R 12 -) and a monomer forming R a2 (-R 12 -R 13 (R 12 -O-**)m-R 12 -) or (-R 12 -R 13x -R 12 Examples of the monomer that forms the bond (-) include compounds represented by the following formula (6):

[0113]

[0114] In the formula (6), R 13 is n having 1 to 20 carbon atoms 61 represents a 2-valent hydrocarbon group, and R 61 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms; n 61 represents an integer of 2 to 4, and n 62 represents an integer of 1 to 5, and n 63 represents an integer of 0 to 4, provided that n 62 and 63 The sum of these is an integer of 1 to 5.

[0115] The compound represented by the formula (6) is preferably a compound represented by the following formula (6-1) or (6-2).

[0116]

[0117] In the formulas (6-1) and (6-2), R 13 , R 61 and n 61 is R in the formula (6). 13 , R 61 and n 61 is synonymous with.

[0118] (-R 12 -R 13 (R 12 -O-**)m-R 12 - or (-R 12 -R 13x -R 12 Examples of the monomer that forms the bond (-) include the following exemplary compounds, but the present invention is not limited to these compounds.

[0119]

[0120] The content of the structural unit represented by formula (1-2) or formula (1-2a) is preferably 5 mol % or more and 95 mol % or less, more preferably 10 mol % or more and 90 mol % or less, and even more preferably 20 mol % or more and 80 mol % or less, relative to 100 mol % of all structural units contained in polymer (A).

[0121] <<Other Structural Units>> The polymer (A) may have structural units (hereinafter also referred to as "other structural units") other than the structural units represented by formula (1-1) and formula (1-2) or formula (1-2a) as necessary. Therefore, examples of the repeating units represented by formula (1-1) include those repeating units bonded to each other, or those bonded to the other structural units or the terminal group Y represented by formula (a). When the polymer (A) has multiple repeating units represented by formula (1-1), multiple R a1 may be the same or different. a2 and similarly for other repeating units.

[0122] Examples of the other structural units include structural units derived from monomers such as compounds that derive structural units containing a carbonate bond, a thiocarbonate bond, or a selenocarbonate bond, such as diphenyl carbonate, diphenyl thiocarbonate, diphenyl selenocarbonate, phosgene, thiophosgene, and selenophosgene; dihydroxy compounds such as benzene dimethanol and cyclohexane dimethanol; phosphine oxide compounds such as bis(fluorophenyl)phenylphosphine oxide, bis(fluorophenyl)naphthylphosphine oxide, and bis(fluorophenyl)anthrylphosphine oxide; and dihalides of dicarboxylic acids such as phthalic acid dichloride, isophthalic acid dichloride, and terephthalic acid dichloride. The monomers that derive the other structural units may be used alone or in combination of two or more.

[0123] [Method for synthesizing polymer (A)] The method for synthesizing polymer (A) is not particularly limited, and known synthesis methods can be used. a1 and a monomer serving as a raw material for the portion containing R a2 and, if necessary, a monomer for forming the terminal group Y and / or a compound represented by formula (6), and a monomer for deriving the other structural unit are heated in an organic solvent together with a polymerization inhibitor, an alkali metal, an alkali metal compound, etc. The monomer for deriving the other structural unit and / or the monomer for forming the terminal group Y may be heated in an organic solvent together with the R a1 and a monomer serving as a raw material for the portion containing R a2 The monomer serving as the raw material for the portion containing R may be polymerized with the compound represented by formula (6) as needed, and then the mixture may be heated and mixed to react with each other. a1 The monomer for deriving the other structural unit and the monomer for forming the terminal group Y are a2 and a monomer serving as a raw material for the portion containing R 13 or R 13x After polymerizing the monomers that are the raw materials for the portion containing the monomer, the mixture may be heated and mixed to cause a reaction.

[0124] -Alkali Metal and Alkali Metal Compound- When a compound having a hydroxy group, such as a phenol compound, is used as a raw material in the synthesis of polymer (A), the alkali metal and alkali metal compounds react with the compound having a hydroxy group to form an alkali metal salt. Examples of such alkali metal and alkali metal compounds include: alkali metals such as lithium, sodium, and potassium; alkali metal hydrides such as lithium hydride, sodium hydride, and potassium hydride; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkali metal carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate; and alkali metal bicarbonates such as lithium bicarbonate, sodium bicarbonate, and potassium bicarbonate. Among these, alkali metal carbonates are preferred, and potassium carbonate is more preferred.

[0125] When a compound having a hydroxy group is used in synthesizing the polymer (A), the amounts of the alkali metal and alkali metal compound used are such that the lower limit of the ratio of the number of moles of alkali metal atoms to the number of moles of hydroxy groups in all compounds used in synthesizing the polymer (A) is preferably 1, more preferably 1.1, and even more preferably 1.2, and the upper limit of the ratio is preferably 3, more preferably 2, and even more preferably 1.8.

[0126] -Organic Solvent- Examples of the organic solvent include: ether-based solvents such as tetrahydrofuran (THF), dioxane, cyclopentyl methyl ether, anisole, phenetole, diphenyl ether, dialkoxybenzene, and trialkoxybenzene; nitrogen-containing solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone; ester-based solvents such as γ-butyrolactone; sulfur-containing solvents such as sulfolane, dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, and diphenyl sulfone; ketone-based solvents such as benzophenone, 2-heptanone, cyclohexanone, and methyl ethyl ketone; halogen-based solvents such as methylene chloride, chloroform, and chlorobenzene; and aromatic hydrocarbon-based solvents such as benzene, toluene, and xylene. Of these organic solvents, 2-heptanone, cyclohexanone, N-methyl-2-pyrrolidone, toluene, and xylene are preferred, and N-methyl-2-pyrrolidone, 2-heptanone, and cyclohexanone are more preferred.

[0127] The lower limit of the reaction temperature during the synthesis is preferably 50° C., more preferably 80° C., and the upper limit of the reaction temperature is preferably 300° C., more preferably 200° C. The lower limit of the reaction time during the synthesis is preferably 1 hour, more preferably 2 hours, and even more preferably 3 hours, and the upper limit of the reaction temperature is preferably 100 hours, more preferably 50 hours, and even more preferably 24 hours.

[0128] For the purpose of suppressing gelation of the polymerization solution, the lower limit of the reaction temperature when the monomer for forming the terminal group Y is added after polymerization is preferably 0° C., more preferably 10° C., and the upper limit of the reaction temperature is preferably 130° C., more preferably 110° C. The lower limit of the reaction time when the monomer for forming the terminal group Y is added after polymerization and reacted is preferably 1 hour, more preferably 2 hours, and even more preferably 3 hours, and the upper limit of the reaction temperature is preferably 48 hours, more preferably 24 hours, and even more preferably 10 hours.

[0129] [Physical Properties of Polymer (A)] The lower limit of the weight average molecular weight (Mw) of the polymer (A) is preferably 1,000, more preferably 2,000, even more preferably 3,000, and particularly preferably 5,000, in terms of polystyrene. The upper limit of the weight average molecular weight (Mw) of the polymer (A) is preferably 500,000, more preferably 100,000, even more preferably 50,000, more preferably 30,000, and particularly preferably 15,000, in terms of polystyrene. When the weight average molecular weight (Mw) of the polymer (A) is within the above range, adhesion, heat resistance, impregnation into glass cloth, moldability such as resin flow, and the like are well balanced and excellent. The weight average molecular weight (Mw) is determined by gel permeation chromatography (GPC) under the conditions described in the Examples below.

[0130] The dielectric loss tangent (tan δ) of the polymer (A) is preferably less than 0.0030, more preferably 0.0020 or less, and even more preferably 0.0012 or less, from the viewpoint of reducing transmission loss when a composition containing the polymer (A) is prepared. The lower limit of the dielectric loss tangent (tan δ) is not particularly limited, but is preferably 0.0005 or more. Specifically, the dielectric loss tangent is determined by the measurement method described in the examples below.

[0131] The content of the polymer (A), when the total mass of the solids in the composition is taken as 100 mass%, is preferably 0.05 mass% or more, more preferably 10 mass% or more, even more preferably 20 mass% or more, and preferably 99.95 mass% or less, more preferably 90 mass% or less, even more preferably 80 mass% or less. The content of the polymer (A) within the above range is preferable because it can further improve the adhesiveness, heat resistance, curability, and electrical properties of the resulting cured product. The polymer (A) may be used alone, or two or more types may be used in combination. When the thermosetting resin composition contains two or more types of polymer (A), for example, polymers (A) having different weight average molecular weights (Mw) within the above weight average molecular weight (Mw) range may be mixed to adjust the desired physical properties.

[0132] <Copolymer (B)> The thermosetting resin composition contains a copolymer (B) (hereinafter, sometimes simply referred to as "copolymer (B)") having structural units derived from ethylene or an α-olefin, structural units derived from an aromatic vinyl compound, and structural units derived from an aromatic polyfunctional vinyl compound. Details of each structural unit contained in the copolymer (B) are described below.

[0133] <<α-Olefins>> The α-olefin is an olefin having 3 or more carbon atoms and a terminal double bond. The α-olefin is preferably a compound composed of carbon atoms and hydrogen atoms and substantially free of oxygen atoms, nitrogen atoms, or halogen atoms, and examples thereof include one or more compounds selected from linear or branched α-olefins and cyclic olefins having 5 to 20 carbon atoms. The α-olefin is preferably an α-olefin having 3 to 20 carbon atoms, more preferably a linear or branched α-olefin having 3 to 20 carbon atoms. The α-olefin is not particularly limited, and examples thereof include propylene, 1-butene, 1-hexene, 1-octene, 1-decane, 1-dodecane, 4-methyl-1-pentene, and 3,5,5-trimethyl-1-hexene.

[0134] The copolymer (B) may contain one or more structural units derived from ethylene or α-olefins. In the copolymer (B), the content of structural units derived from ethylene or α-olefins (when two or more structural units derived from ethylene or α-olefins are contained, the total content of all structural units) is preferably 35% by mass or more, and particularly preferably 45% by mass or more. The total of the structural units derived from ethylene or α-olefins, the structural units derived from aromatic vinyl compounds, and the structural units derived from aromatic polyfunctional vinyl compounds is 100% by mass. When the content of structural units derived from ethylene or α-olefins is 35% by mass or more, the toughness (elongation) of the final cured product is improved, and cracking during curing, a decrease in the impact resistance of the cured product, and cracking during heat cycle testing of the cured product are suppressed. The content of structural units derived from ethylene or α-olefins in the copolymer (B) is preferably 90% by mass or less.

[0135] When copolymer (B) contains structural units derived from ethylene and structural units derived from an α-olefin, the mass ratio of the structural units derived from the α-olefin to the structural units derived from ethylene is preferably 1 / 7 or less, more preferably 1 / 10 or less, because the resulting cured product has improved breaking strength (strength at break) and elongation at break (elongation at break), and the peel strength from copper foil or copper wiring is improved. The content of structural units derived from the α-olefin contained in copolymer (B) is more preferably 6% by mass or less, and most preferably 4% by mass or less. Such a content is more preferred because it further improves the peel strength from copper foil or copper wiring. When combining ethylene and an α-olefin, the glass transition temperature of the ethylene-α-olefin-aromatic vinyl compound-aromatic polyfunctional vinyl compound chain of the finally obtained cured product can be appropriately adjusted within the range of approximately -60°C to -5°C depending on the type and content of the α-olefin.

[0136] <<Aromatic Vinyl Compound>> An aromatic vinyl compound is an aromatic hydrocarbon compound having one vinyl group per molecule, and is preferably an aromatic vinyl compound having a carbon number of 8 to 20. Examples of aromatic vinyl compounds include styrene, paramethylstyrene, paraisobutylstyrene, various vinylnaphthalenes, and various vinylanthracenes.

[0137] When the mass of all structural units constituting copolymer (B) is taken as 100 mass%, the content of structural units derived from aromatic vinyl compounds is preferably more than 0 mass% and not more than 70 mass%, more preferably 10 mass% or more and less than 60 mass%. The structural units derived from aromatic vinyl compounds may be contained in copolymer (B) singly or in combination of two or more types.

[0138] <<Aromatic Polyfunctional Vinyl Compounds>> An aromatic polyfunctional vinyl compound is a compound having multiple vinyl groups and one or more aromatic groups in one molecule. That is, an aromatic polyfunctional vinyl compound is a compound in which, even if one of the multiple vinyl groups is used in a polymerization reaction and polymerized, the remaining vinyl groups remain reactive. The carbon number of the aromatic polyfunctional vinyl compound is preferably 5 to 20, and more preferably 8 to 20. The aromatic polyfunctional vinyl compound is preferably an aromatic hydrocarbon compound having two vinyl groups in one molecule, such as ortho-, meta-, and para-divinylbenzenes or mixtures thereof, divinylnaphthalene, divinylanthracene, p-(2-propenyl)styrene, p-(3-butenyl)styrene, and 1,2-bis(vinylphenyl)ethane. Among these, the aromatic polyfunctional vinyl compound is preferably ortho-, meta-, or para-divinylbenzenes or mixtures thereof, and most preferably a mixture of meta- and para-divinylbenzenes. In this specification, these divinylbenzenes may be referred to as "divinylbenzenes." When a divinylbenzene is used as the aromatic polyfunctional vinyl compound, the curing efficiency is excellent when the resin composition is subjected to a curing treatment, and the resin composition is easily cured, which is preferable.

[0139] Each of the above ethylene, α-olefin, aromatic vinyl compound, and aromatic polyfunctional vinyl compound monomers may contain a polar group, for example, an olefin containing an oxygen atom, a nitrogen atom, or the like, an aromatic vinyl compound containing an oxygen atom, a nitrogen atom, or the like, or an aromatic polyfunctional vinyl compound containing an oxygen atom, a nitrogen atom, or the like. The content of structural units derived from monomers containing polar groups is preferably 10% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, based on the mass of all structural units in the copolymer (B). It is most preferable that the copolymer (B) is substantially free of structural units derived from monomers containing polar groups. By ensuring that the content of structural units derived from monomers containing polar groups is 10% by mass or less, the low dielectric properties (low dielectric constant / low dielectric loss) of the cured product obtained by curing the thermosetting resin composition are further improved.

[0140] When the mass of all structural units constituting copolymer (B) is taken as 100 mass%, the content of structural units derived from aromatic polyfunctional vinyl compounds is preferably more than 0 mass% and not more than 70 mass%, more preferably 10 mass% or more and less than 60 mass%. The structural units derived from aromatic polyfunctional vinyl compounds may be contained in copolymer (B) singly or in combination of two or more types.

[0141] The number average molecular weight (Mn) of the copolymer (B) is preferably 500 or more and 100,000 or less, more preferably 20,000 or more and 100,000 or less, and even more preferably 30,000 or more and 100,000 or less. A number average molecular weight (Mn) of 500 or more can easily impart good physical properties such as high strength at break and high elongation at break to the final cured product, and is preferable because it easily imparts toughness. Specifically, it preferably exhibits a tensile elongation at break (tensile elongation at break) of 30% or more. When the number average molecular weight (Mn) is 20,000 or more, the thermosetting resin composition becomes less sticky in the uncured state, resulting in the effect of improving thermoplasticity. When the number average molecular weight (Mn) is 100,000 or less, the thermosetting resin composition before curing can be easily molded. The number average molecular weight (Mn) is determined by gel permeation chromatography (GPC) under the conditions described in the Examples below.

[0142] When the mass of all structural units constituting copolymer (B) is taken as 100 mass%, the content of structural units derived from aromatic vinyl compounds contained in copolymer (B) is preferably 10 mass% or more and less than 60 mass%. When the content of structural units derived from aromatic vinyl compounds is less than 60 mass%, the glass transition temperature of the cured product of the final composition is unlikely to be near room temperature, which can suppress a decrease in toughness at low temperatures and also suppress a decrease in elongation. Furthermore, when the content of structural units derived from aromatic vinyl compounds is less than 60 mass%, the peel strength with metal foil (particularly copper foil) can be improved compared to when it is 60 mass% or more.

[0143] When the mass of all structural units constituting copolymer (B) is 100 mass%, the content of structural units derived from aromatic vinyl compounds contained in copolymer (B) is particularly preferably 10 mass% or more and 55 mass% or less.When the content of structural units derived from aromatic vinyl compounds is 10 mass% or more, the decrease in aromaticity of copolymer (B) is suppressed, compatibility with flame retardants and fillers is improved, and when the composition contains a flame retardant, bleeding out is suppressed and the ease of filling with fillers can be improved.In addition, when the content of structural units derived from aromatic vinyl compounds is 10 mass% or more, a cured product having high peel strength with metal foil (especially copper foil) or copper wiring is easily obtained.

[0144] In copolymer (B), the content of vinyl groups derived from structural units derived from an aromatic polyfunctional vinyl compound (hereinafter also referred to as "aromatic polyfunctional vinyl units") (hereinafter also referred to as "vinyl group content") is preferably 1.5 or more but less than 20, more preferably 3 or more but less than 20, per number average molecular weight of copolymer (B). A vinyl group content of 1.5 or more provides excellent crosslinking efficiency and can further increase the storage modulus at high temperatures. By setting the vinyl group content within the above range, it is possible to further increase crosslinking efficiency and crosslinking density, and to easily increase the storage modulus at high temperatures, while maintaining or improving mechanical properties such as breaking strength and breaking elongation at room temperature, which is preferable. This effect is particularly pronounced when the amount of aromatic polyfunctional vinyl compound used is relatively low.

[0145] The vinyl group content derived from aromatic polyfunctional vinyl units (for example, divinylbenzene units) per number average molecular weight (Mn) in the copolymer (B) can be calculated by the ratio of the number average molecular weight (Mn) calculated in terms of standard polystyrene obtained by a GPC (gel permeation chromatography) method known to those skilled in the art to the 1 It can be determined by comparing the vinyl group content derived from the aromatic polyfunctional vinyl compound obtained by H-NMR measurement. For example, 1 By comparing the intensities of each peak area obtained by H-NMR measurement, if the content of vinyl groups derived from aromatic polyfunctional vinyl units in copolymer (B) is 0.095% by mass and the number average molecular weight (Mn) converted to standard polystyrene by GPC measurement is 68,000, the molecular weight of vinyl groups derived from aromatic polyfunctional vinyl units in the number average molecular weight (Mn) is the product of these two, 64.8, which is obtained by dividing this by the formula weight of the vinyl groups, 27, to obtain 2.4. In other words, the content of vinyl groups derived from aromatic polyfunctional vinyl units per number average molecular weight (Mn) in copolymer (B) is determined to be 2.4.

[0146] Copolymer (B) 1 The peak assignments obtained by H-NMR measurement are determined from known literature. 1 The composition of the copolymer (B) can be determined by a known method from a comparison of the peak areas obtained by H-NMR measurement. In addition, in this specification, when the aromatic polyfunctional vinyl unit in the copolymer (B) is, for example, a divinylbenzene unit, the content of the divinylbenzene unit can be determined by the peak intensity ( 1 That is, from the content of vinyl groups derived from divinylbenzene units, the content of divinylbenzene units can be determined by assuming that one vinyl group is derived from one divinylbenzene unit in copolymer (B).

[0147] Examples of the copolymer (B) include an ethylene-styrene-divinylbenzene copolymer, an ethylene-propylene-styrene-divinylbenzene copolymer, an ethylene-1-hexene-styrene-divinylbenzene copolymer, and an ethylene-1-octene-styrene-divinylbenzene copolymer.

[0148] The copolymer (B) preferably satisfies any one of the following (1) to (3), and more preferably satisfies all of (1) to (3).

[0149] (1) The number average molecular weight (Mn) of the copolymer (B) is preferably 500 or more and 100,000 or less, more preferably 20,000 or more and 100,000 or less, and even more preferably 30,000 or more and 100,000 or less.

[0150] (2) The aromatic vinyl compound is preferably an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of structural units derived from the aromatic vinyl compound is preferably more than 0% by mass and not more than 70% by mass, more preferably 10% by mass or more and less than 60% by mass, when all structural units constituting the copolymer (B) are taken as 100% by mass.

[0151] (3) The α-olefin in the copolymer (B) is preferably one or more α-olefins selected from α-olefins having from 3 to 20 carbon atoms, and the total of the structural units derived from ethylene or the α-olefin, the structural units derived from an aromatic vinyl compound, and the structural units derived from an aromatic polyfunctional vinyl compound is 100% by mass.

[0152] The copolymer (B) may further satisfy the following condition (4): (4) The aromatic polyfunctional vinyl compound is an aromatic polyfunctional vinyl compound having 5 to 20 carbon atoms and having a plurality of vinyl groups in one molecule, and the content of vinyl groups derived from aromatic polyfunctional vinyl units is preferably 1.5 to less than 20 per number average molecular weight (Mn) of the copolymer (B).

[0153] [Method for producing copolymer (B)] There are no particular limitations on the method for producing copolymer (B), and any known method can be used. Examples of the method for producing copolymer (B) include the methods described in JP 2009-161743 A, JP 2010-280771 A, and WO 2000 / 37517 A.

[0154] The method for synthesizing the copolymer (B) is not particularly limited, and any known synthesis method can be used. The copolymer (B) can be obtained, for example, by copolymerizing each of the monomers of an α-olefin, an aromatic vinyl compound, and an aromatic polyfunctional vinyl compound.

[0155] <<Curable Compound (C)>> The thermosetting resin composition may contain a curable compound (C). The curable compound (C) is a compound other than the polymer (A) and copolymer (B), and is a compound that cures upon irradiation with heat or light (e.g., visible light, ultraviolet light, near-infrared light, far-infrared light). The curable compound (C) may also be used in combination with a curing aid, which will be described later. The curable compound (C) is not particularly limited, and examples thereof include vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds. Among these, from the viewpoints of compatibility with the polymer (A), reactivity, etc., the curable compound (C) is preferably at least one compound selected from the group consisting of vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds, and more preferably at least one compound selected from the group consisting of vinyl compounds, maleimide compounds, and allyl compounds. The curable compound (C) may be used alone or in combination of two or more.

[0156] Examples of the vinyl compound include compounds represented by the following formulas (b-1-1) to (b-1-5): However, the vinyl compound in the present invention is not limited to these exemplified compounds.

[0157]

[0158] In formulas (b-1-2) and (b-1-4), n each independently represents an integer of 1 to 5000. In formula (b-1-5), l, m, and n each independently represent an integer of 1 to 5000.

[0159] Examples of the maleimide compound include compounds represented by the following formulas (b-2-1) to (b-2-8): However, the maleimide compound in the present invention is not limited to these exemplified compounds.

[0160]

[0161] In formulas (b-2-4), (b-2-5), (b-2-7) and (b-2-8), n is independently an integer of 1 to 50.

[0162] Examples of the allyl compound include compounds represented by the following formulas (b-3-1) to (b-3-6): However, the allyl compound in the present invention is not limited to these exemplified compounds.

[0163]

[0164] Examples of the acrylic compound include compounds represented by the following formulas (b-4-1) to (b-4-7): However, the acrylic compound in the present invention is not limited to these exemplified compounds.

[0165]

[0166] In formulas (b-4-1), (b-4-2), (b-4-3) and (b-4-6), n is independently an integer of 1 to 50. In formula (b-4-3), m is an integer of 1 to 50. In formula (b-4-6), R is a divalent hydrocarbon group having 1 to 20 carbon atoms.

[0167] The methacrylic compound is not particularly limited, and examples thereof include bisphenol A type epoxy methacrylate, phenol novolac type epoxy methacrylate, trimethylolpropane methacrylate, dipentaerythritol hexamethacrylate, and SA-9000 (manufactured by Sabic).

[0168] The thiol compound is not particularly limited, and examples thereof include 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinane-2,4,6-trione, 2-(dibutylamino)-1,3,5-triazine-4,6-dithiol, and 6-diallylamino-1,3,5-triazine-2,4-dithiol.

[0169] The silane compound is not particularly limited, and examples thereof include KF-99 (manufactured by Shin-Etsu Chemical Co., Ltd.) and KF-9901 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0170] Examples of the oxazine compound include compounds represented by the following formulas (b-5-1) to (b-5-5): However, the oxazine compound in the present invention is not limited to these exemplary compounds.

[0171]

[0172] Examples of the cyanate compound include compounds represented by the following formulas (b-6-1) to (b-6-7): However, the cyanate compound in the present invention is not limited to these exemplified compounds.

[0173]

[0174] In formulas (b-6-6) and (b-6-7), n is independently an integer of 0 to 30.

[0175] The epoxy compound is not particularly limited, and examples thereof include compounds represented by the following formulas (b-7-1) to (b-7-5): Examples of the epoxy compound include polyglycidyl ether of dicyclopentadiene-phenol polymer, phenol novolac liquid epoxy compound, cresol novolac epoxy compound, epoxidized product of styrene-butadiene block copolymer, 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, XER-81 (manufactured by JSR Corporation, epoxy group-containing NBR particles), and JP-100 (manufactured by Nippon Soda Co., Ltd.).

[0176]

[0177] In formula (b-7-5), n is an integer of 0 to 5,000.

[0178] Examples of the oxetane compound include compounds represented by the following formulas (b-8-1) to (b-8-3): However, the oxetane compound in the present invention is not limited to these exemplified compounds.

[0179]

[0180] In formulas (b-8-1) and (b-8-2), n is each independently an integer of 0 to 30.

[0181] The methylol compound is not particularly limited, and examples thereof include the methylol compounds described in JP-A-2006-178059 and JP-A-2012-226297. Specific examples include melamine-based methylol compounds such as polymethylolated melamine, hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, and hexabutoxymethyl melamine; glycoluril-based methylol compounds such as polymethylolated glycoluril, tetramethoxymethyl glycoluril, and tetrabutoxymethyl glycoluril; and guanamine-based methylol compounds such as methylolated guanamine compounds such as 3,9-bis[2-(3,5-diamino-2,4,6-triazaphenyl)ethyl]-2,4,8,10-tetraoxospiro[5.5]undecane and 3,9-bis[2-(3,5-diamino-2,4,6-triazaphenyl)propyl]-2,4,8,10-tetraoxospiro[5.5]undecane, and compounds in which all or part of the active methylol groups in the compounds have been alkyl-etherified.

[0182] The benzocyclobutene compound is not particularly limited, and examples thereof include the compounds described in JP-A-2005-60507.

[0183] Examples of the propargyl compound include compounds represented by the following formulas (b-9-1) and (b-9-2): However, the propargyl compound in the present invention is not limited to these exemplified compounds.

[0184]

[0185] [Content of curable compound (C)] The content of compound (C) in the thermosetting resin composition is preferably 0.05% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 50% by mass or less, when the total solid content in the curable resin composition is taken as 100% by mass. When the content of curable compound (C) is within the above range, it is preferable from the viewpoint of further improving the strength and heat resistance of the cured product obtained from the thermosetting resin composition.

[0186] Furthermore, when the total solid content of the polymer (A) and the copolymer (B) in the thermosetting resin composition is taken as 100% by mass, the lower limit of the content of the curable compound (C) is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and the upper limit of the content of the curable compound (C) is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less. A content of the curable compound (C) within the above range is preferred from the viewpoint of further improving the toughness and heat resistance of the obtained cured product, etc.

[0187] <<Polymerization initiator (D)>> The thermosetting resin composition may contain a polymerization initiator (D). The polymerization initiator (D) is not particularly limited, and includes known polymerization initiators used in thermosetting resin compositions. Examples of the polymerization initiator (D) include polymerization initiators such as thermal or photoradical polymerization initiators, cationic curing agents, and anionic curing agents.

[0188] Examples of the thermal or photoradical polymerization initiator include organic peroxides such as dicumyl peroxide, 1,1-di(t-butylperoxy)cyclohexane, di(t-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, and benzoyl peroxide; and azo compounds such as azobisbutyronitrile, 1,1'-azobis(1-acetoxy-1-phenylethane), 2,2'-azobis(2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), dimethyl-2,2'-azobis(isobutyrate), and 2,2'-azobis(2-methylbutyronitrile).

[0189] Examples of cationic curing agents include SP70, SP172, and CP66 manufactured by ADEKA Corporation; CI2855 and CI2823 manufactured by Nippon Soda Co., Ltd.; and SI100 and SI150 manufactured by Sanshin Chemical Industry Co., Ltd.; diallyliodonium salts having BF, PF, SbF, or the like as a counter anion, trialkylsulfonium salts, phosphonium salts such as butyltriphenylphosphonium thiocyanate, and boron trifluoride.

[0190] Examples of the anionic curing agent include imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-methylimidazolium isocyanurate, 2,4-diamino-6-[2-methylimidazoline-(1)]-ethyl-S-triazine, and 2,4-diamino-6-[2-ethyl-4-methylimidazoline-(1)]-ethyl-S-triazine; phosphorus compounds such as triphenylphosphine; and amine compounds such as 4,4'-diaminodiphenylmethane.

[0191] Furthermore, examples of the curing aid when a silane compound is used as the curable compound (C) include platinum group metal catalysts such as platinum black, platinic chloride, chloroplatinic acid, reaction products of chloroplatinic acid with monohydric alcohols, complexes of chloroplatinic acid with olefins, platinum-based catalysts such as platinum bisacetoacetate; palladium-based catalysts; and rhodium-based catalysts; zinc benzoate; and zinc octoate.

[0192] Examples of the curing aid when an oxazine compound is used as the curable compound (C) include curing agents such as phenol and its derivatives, cyanate esters, Bronsted acids such as p-toluenesulfonic acid, aromatic amine compounds such as adipic acid, p-toluenesulfonic acid esters, 4,4'-diaminodiphenyl sulfone, and melamine, bases such as 2-ethyl-4-methylimidazole, boron trifluoride, and Lewis acids.

[0193] When the thermosetting resin composition contains a curing aid, the content of the curing aid is preferably within a range in which the composition is well cured to obtain a cured product. Specifically, the content of the curing aid is preferably 0.000001 parts by mass or more, more preferably 0.001 parts by mass or more, and preferably 20 parts by mass or less, more preferably 10 parts by mass or less, per 100 parts by mass of the total solid content of the polymer (A) and the copolymer (B).

[0194] <<Organic Solvent (E)>> The thermosetting resin composition preferably further contains an organic solvent (E), and more preferably further contains the curable compound (C) and the organic solvent (E). Examples of the organic solvent (E) include amide solvents such as N,N-dimethylformamide, ester solvents such as γ-butyrolactone and butyl acetate, ketone solvents such as cyclopentanone, cyclohexanone, methyl ethyl ketone and 2-heptanone, ether solvents such as 1,2-methoxyethane, anisole and tetrahydrofuran, polyfunctional solvents such as 1-methoxy-2-propanol and propylene glycol methyl ether acetate, sulfone solvents such as dimethyl sulfoxide, methylene chloride, benzene, toluene, xylene, and trialkoxybenzene (number of carbon atoms in the alkoxy group: 1 to 4).

[0195] The content ratio of organic solvent (E) is not particularly limited, and can be appropriately changed according to purpose.For example, it is preferably 0 parts by mass or more and 2000 parts by mass or less, more preferably 0 parts by mass or more and 1000 parts by mass or less, relative to the total 100 parts by mass of the solid content of polymer (A), copolymer (B) and curable compound (C).In addition, when the solubility of polymer (A), copolymer (B) and curable compound (C) in organic solvent (E) is high, the content ratio of organic solvent (E) may be 50 parts by mass or more and 200 parts by mass or less.

[0196] <<Filler (F)>> The thermosetting resin composition may contain a filler (F). The filler (F) is not particularly limited and may be an inorganic filler or an organic filler. The inorganic filler is not particularly limited and examples thereof include silicas such as natural silica, fused silica, and amorphous silica, white carbon, titanium white, aerosil, alumina, talc, natural mica, synthetic mica, clay, barium sulfate, E-glass, A-glass, C-glass, L-glass, D-glass, S-glass, S-glass, and M-glass G20. The inorganic filler may be surface-treated. The surface treatment agent is not particularly limited and known surface treatment agents can be used. Examples of the surface treatment agent include silane coupling agents.

[0197] When the thermosetting resin composition contains an inorganic filler, the content of the inorganic filler is, for example, preferably 0.1 parts by mass or more and 300 parts by mass or less per 100 parts by mass of the total solid content of the polymer (A) and the copolymer (B). The inorganic filler may be in a state of being dispersed in the solvent by the polymer (A).

[0198] Examples of the organic filler include fluorine-based resins or fluorine-based particles such as polytetrafluoroethylene (PTFE), polyperfluoroalkoxy resins, polyfluorinated ethylene propylene resins, and polytetrafluoroethylene-polyethylene copolymers; polystyrene resins or particles; rubber-like resins or particles such as polybutadiene and styrene-butadiene resins; and hollow particles having a shell of divinylbenzene or divinylbiphenyl.

[0199] When the thermosetting resin composition contains an organic filler, the content of the organic filler is, for example, preferably 0.1 parts by mass or more and 300 parts by mass or less, relative to 100 parts by mass of the total solid content of the polymer (A) and the copolymer (B). The organic filler may be in a state of being dispersed in the solvent by the polymer (A).

[0200] <<Additives>> The thermosetting resin composition may contain components other than the polymer (A), copolymer (B), curable compound (C), polymerization initiator (D), organic solvent (E), and filler (F) (hereinafter also referred to as "other components") for the purpose of imparting various functions. Examples of the other components include additives such as antioxidants, flame retardants, and adhesion aids. Examples of antioxidants include hindered phenol compounds, phosphorus compounds, sulfur compounds, metal compounds, and hindered amine compounds. Among these, hindered phenol compounds are preferred as antioxidants.

[0201] The hindered phenol compound is preferably a compound having a molecular weight of 500 or more. Examples of the hindered phenol compound having a molecular weight of 500 or more include triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-3,5-triazine, pentaerythritol tetrakis[3-(3,5-t-butyl-4-hydroxyphenyl)propionate], phenyl)propionate], 1,1,3-tris[2-methyl-4-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-5-t-butylphenyl]butane, 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, N,N-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3, 5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 3,9-bis[2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 2,6-di-tert-butyl-p-cresol (BHT), 1,3,5-tris(3,5-di-t (1H,3H,5H)-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione [manufactured by ADEKA Corporation, AO-020], 4,4',4''-(1-methylpropanyl-3-ylidene)tris(6-tert-butyl-m-cresol) [manufactured by ADEKA Corporation, AO-030], 6,6'-di-tert-butyl-4,4'-butylidenedi-m-cresol [manufactured by ADEKA Corporation, AO-040],1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene [manufactured by ADEKA Corporation, AO-330] is an example.

[0202] Examples of hindered amine compounds include 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl [ADEKA CORPORATION, Adekastab LA-7RD], IRGASTABUV 10 (4,4'-[1,10-dioxo-1,10-decanediyl)bis(oxy)]bis[2,2,6,6-tetramethyl]-1-piperidinyloxy) (CAS. 2516-92-9), TINUVIN 123 (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl) (all manufactured by BASF), FA-711HM, FA-712HM (2,2,6,6-tetramethylpiperidinyl methacrylate, manufactured by Showa Denko Materials Co., Ltd.), TINUVIN 111FDL, TINUVIN 144, TINUVIN 152, TINUVIN 292, TINUVIN 765, TINUVIN 770DF, TINUVIN 5100, SANOLLS-2626, CHIMASSORB 119FL, CHIMASSORB 2020 FDL, CHIMASSORB 944 FDL, TINUVIN 622 LD (all manufactured by BASF), LA-52, LA-57, LA-62, LA-63P, LA-68LD, LA-77Y, LA-77G, LA-81, LA-82 (1,2,2,6,6-pentamethyl-4-piperidyl methacrylate), and LA-87 (all manufactured by ADEKA Corporation).

[0203] When the thermosetting resin composition contains the above-mentioned additive, the content of the additive is preferably 0.001 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the total solid content of the polymer (A) and the copolymer (B).

[0204] [Method for preparing thermosetting resin composition] The thermosetting resin composition can be prepared, for example, by uniformly mixing the polymer (A), copolymer (B), curable compound (C), polymerization initiator (D), organic solvent (E), filler (F), and the other components. In this case, the order in which the components are mixed and the mixing conditions are not particularly limited, and a conventionally known mixer can be used for mixing.

[0205] <Cured Product> The cured product according to the present invention is made of the above-mentioned thermosetting resin composition. The cured product is a cured body obtained by curing the above-mentioned thermosetting resin composition. The cured product may be, for example, a partially cured product of the thermosetting resin composition obtained by drying the solvent from the thermosetting resin composition. The method for curing the thermosetting resin composition is not particularly limited, and known curing methods can be used, and typical examples include a method of thermal curing by heating and a method of photocuring by irradiating light. Note that a plurality of curing methods may be used in combination.

[0206] In the case of heat curing, the heating temperature is preferably 50° C. or higher, more preferably 100° C. or higher, even more preferably 120° C. or higher, and preferably 250° C. or lower, more preferably 220° C. or lower. The heating time is preferably 0.1 hour or longer, more preferably 0.5 hour or longer, and preferably 36 hours or shorter, more preferably 5 hours or shorter. In the case of photocuring, examples of the light to be irradiated include visible light, ultraviolet light, near infrared light, and far infrared light.

[0207] <<Glass Transition Temperature (Tg)>> The lower limit of the glass transition temperature (Tg) of the cured product is preferably 100°C, more preferably 110°C, and the upper limit is, for example, 300°C. When the Tg is within this range, melt molding can be more easily performed, and a cured product with excellent heat resistance can be easily obtained. The glass transition temperature (Tg) can be determined by the measurement method described in the examples below.

[0208] The dielectric loss tangent (tan δ) of the cured product is preferably 0.0025 or less, more preferably 0.0018 or less, and even more preferably 0.0015 or less, from the viewpoint of reducing transmission loss, etc. The lower limit is not particularly limited, but is preferably 0.0005 or more. Specifically, the dielectric loss tangent can be determined by measuring it using the method described in the examples below.

[0209] The shape of the cured product is not particularly limited, and a suitable shape can be appropriately selected depending on the application, purpose, etc. Examples of the shape of the cured product include a film, a plate, a rod, etc. For example, a film-shaped cured product can be obtained by melt molding or cast molding the thermosetting resin composition.

[0210] The thickness of the cured product is not particularly limited and can be appropriately selected depending on the desired application. The thickness is, for example, 10 μm or more, preferably 30 μm or more, and for example, 2 mm or less, preferably 1 mm or less.

[0211] Alternatively, the laminate may include a layer of the cured product (cured product layer) and a substrate. The laminate may include two or more substrate layers, two or more cured product layers, or may include a conventionally known layer other than the substrate and the cured product layer. In the laminate, the substrate and the cured product layer may be in contact with each other, or another layer may be provided between the substrate and the cured product layer. When the laminate includes two or more substrate layers, cured product layers, or other layers, these may be the same layer (plate) or different layers (plates).

[0212] Examples of the substrate include inorganic substrates, metal substrates, and resin substrates from the viewpoints of adhesiveness and practicality. Furthermore, a prepreg, which will be described later, may also be used as the substrate. Examples of the inorganic substrate include inorganic substrates containing silicon, silicon carbide, silicon nitride, alumina, glass, gallium nitride, etc. as components. Examples of the metal substrate include metal substrates containing copper, aluminum, gold, silver, nickel, palladium, etc. as components. The shape of the metal substrate is not particularly limited and may be a plate or metal foil. The copper-clad laminate according to the present invention is a laminate of a prepreg, which will be described later, and a copper substrate, and preferably a laminate of a prepreg, which will be described later, and a copper foil. Examples of the resin substrate include resin substrates containing a liquid crystal polymer, polyimide, polyphenylene sulfide, polyether ether ketone, polyamide (nylon), polyethylene terephthalate, polyethylene naphthalate, cycloolefin polymer, polyolefin, etc.

[0213] The method for forming the cured product layer is not particularly limited, and examples thereof include the curing methods described in the section on cured products. The thickness of the cured product layer is not particularly limited, and is, for example, 1 μm to 3 mm.

[0214] <<Prepreg>> The prepreg according to the present invention is obtained by impregnating a fibrous substrate plate with the thermosetting resin composition. The substrate is not particularly limited, and suitable examples include fibrous substrates such as glass cloth, aramid nonwoven fabric, and polyester nonwoven fabric. The prepreg may be a cured prepreg.

[0215] <<Applications>> The thermosetting resin composition and cured product can be suitably used as structural materials in the transportation industry, such as the aircraft and automobile industries, and electrical and electronic materials in the electrical and electronics industry. Specifically, they can be suitably used in, for example, sealing materials for electrical and electronic components, interlayer insulating films (films), stress relaxation primers; laminate applications (e.g., prepregs, copper-clad laminates, (multilayer) printed wiring boards, interlayer adhesives, solder resists, solder pastes); adhesive applications (e.g., adhesive sheets for forming insulating layers, thermally conductive adhesives, adhesive sheets); structural adhesives and prepregs used in various structural materials; various coatings; optical component applications (e.g., optical films such as wavelength plates and retardation plates, various special lenses such as conical lenses, spherical lenses, and cylindrical lenses, lens arrays), and insulating films for printed wiring boards. In particular, interlayer insulating films containing the thermosetting resin composition have low dielectric tangent, excellent adhesion, and heat resistance.

[0216] Examples of the electronic components include circuit boards, semiconductor packages, and display substrates. The cured product (cured film) can be used for these electronic components as prepregs, copper-clad laminates, printed wiring boards, adhesive sheets for forming insulating layers, surface protective films, rewiring layers, or planarizing films. Because the cured product can maintain its insulating properties even under high temperature and high humidity, electronic components equipped with the cured product can protect circuit patterns from external environments such as dust, heat, and humidity, and have excellent insulation reliability between circuit patterns, enabling stable operation over many years.

[0217] For example, the cured product can be used to fill metal between patterns formed on the cured product (cured film) by plating or the like, and if necessary, further cured products (cured films) can be stacked and metal filling can be repeated to form a rewiring layer, thereby producing an electronic component having a substrate and a rewiring layer including metal wiring and an insulating film.

[0218] The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples in any way.

[0219] Synthesis Example 1: 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (20.3 g), 2,5-di-t-butylhydroquinone (8.9 g), 4,6-dichloropyrimidine (14.9 g), and potassium carbonate (18.7 g) were weighed into a four-neck separable flask equipped with a stirrer, and N-methyl-2-pyrrolidone (102.9 g) was added. The mixture was reacted at 130°C for 6 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was diluted with N-methyl-2-pyrrolidone (206 g). The salt was removed by filtration, and the resulting solution was then poured into methanol (7 kg). The precipitated solid was filtered off, washed with a small amount of methanol, and recovered by filtration again. The solid was then dried under reduced pressure at 120°C for 12 hours using a vacuum dryer to obtain a polymer (A1) having the structural unit shown in formula (1) below.

[0220]

[0221] Synthesis Example 2: 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (25.4 g), 4,6-dichloropyrimidine (11.2 g), and potassium carbonate (14.0 g) were weighed into a four-neck separable flask equipped with a stirrer, and N-methyl-2-pyrrolidone (85 g) was added. The mixture was reacted at 130°C for 6 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was diluted with N-methyl-2-pyrrolidone (300 g). The salt was removed by filtration, and the resulting solution was then poured into methanol (6 kg). The precipitated solid was filtered off, washed with a small amount of methanol, and recovered by filtration again. The solid was then dried under reduced pressure at 120°C for 12 hours using a vacuum dryer to obtain a polymer (A2) having a structural unit represented by the following formula (2):

[0222]

[0223] Synthesis Example 3: 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (62.08 g), 4,6-dichloropyrimidine (30.99 g), isopropenylphenol (2.170 g), and potassium carbonate (38.83 g) were weighed into a four-neck separable flask equipped with a stirrer, and N-methyl-2-pyrrolidone (64.00 g) was added. The mixture was reacted at 130°C for 6 hours under a nitrogen atmosphere. After completion of the reaction, the mixture was diluted with N-methyl-2-pyrrolidone (368.0 g). After removing the salt by filtration, the resulting solution was poured into methanol (19.4 kg). The precipitated solid was separated by filtration, washed with a small amount of methanol, and recovered by filtration again. The solid was then dried under reduced pressure at 120°C for 12 hours using a vacuum dryer to obtain a polymer (A3) having a structural unit represented by the following formula (3):

[0224]

[0225] Synthesis Example 4: 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (86.92 g), 4,6-dichloropyrimidine (47.58 g), and potassium carbonate (59.66 g) were weighed into a four-neck separable flask equipped with a stirrer, and N-methyl-2-pyrrolidone (64.00 g) was added. The mixture was reacted at 130°C for 6 hours under a nitrogen atmosphere. After the reaction, allyl bromide (10.67 g) was added dropwise to the vessel cooled to 10°C, and the mixture was reacted at 70°C for 6 hours. The resulting reaction solution was diluted with N-methyl-2-pyrrolidone (368.0 g), and the salt was removed from the diluted solution by filtration. The resulting solution was then poured into methanol (19.40 kg). The precipitated solid was filtered off, washed with a small amount of methanol, and recovered by filtration again. The solid was then dried under reduced pressure at 120°C for 12 hours using a vacuum dryer to obtain a polymer (A4) represented by the following formula (4).

[0226]

[0227] Synthesis Example 5 Polymer (A5) represented by the following formula (5) was obtained in the same manner as in Synthesis Example 3, except that the raw materials and alkali metal compound used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (51.27 g), isopropenylphenol (7.83 g), 4,6-dichloro-2-phenylpyrimidine (51.51 g), and potassium carbonate (35.93 g).

[0228]

[0229] Synthesis Example 6: 2,2-bis(4-hydroxy-3-methylphenyl)propane (26.43 g), 4,6-dichloro-2-phenylpyrimidine (17.08 g), and potassium carbonate (19.23 g) were weighed into a four-neck separable flask equipped with a stirrer, and N-methyl-2-pyrrolidone (42.50 g) was added. The mixture was reacted at 100°C for 6 hours under a nitrogen atmosphere. After the reaction, m,p-(chloromethyl)styrene (11.53 g) was added dropwise with the vessel cooled to 10°C, and the mixture was reacted at 100°C for 4 hours. The resulting reaction solution was diluted with N-methyl-2-pyrrolidone (55.0 g), and the salt was removed from the diluted solution by filtration. The resulting solution was then poured into methanol (6900 g). The precipitated solid was filtered off, washed with a small amount of methanol, and recovered by filtration again. The solid was then dried under reduced pressure at 60°C for 12 hours using a vacuum dryer to obtain a polymer (A6) represented by the following formula (6).

[0230]

[0231] Synthesis Example 7 Polymer (A7) represented by the following formula (7) was obtained in the same manner as in Synthesis Example 6, except that the raw materials and alkali metal compound used were changed to 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (33.85 g), 4,6-dichloro-2-phenylpyrimidine (16.66 g), m,p-chloromethylstyrene (8.680 g), potassium carbonate (18.66 g), and N-methyl-2-pyrrolidone (42.50 g).

[0232]

[0233] Synthesis Example 8 Polymer (A8) represented by the following formula (8) was obtained in the same manner as in Synthesis Example 3, except that the raw materials and alkali metal compound used were changed to 2,2-bis(4-hydroxy-3-methylphenyl)propane (25.63 g), 4,6-dichloro-2-phenylpyrimidine (29.25 g), 2-allylphenol (8.131 g), and potassium carbonate (24.31 g).

[0234]

[0235] Synthesis Example 9: 2,2-bis(3-methyl-4-hydroxyphenyl)propane (51.27 g), α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (21.23 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), and potassium carbonate (51.31 g) were weighed into a four-neck separable flask equipped with a stirrer, and N-methyl-2-pyrrolidone (113.92 g) was added. The mixture was reacted at 130°C for 6 hours under a nitrogen atmosphere. After the reaction, the vessel was cooled to 10°C, and chloromethylstyrene (38.55 g) was added dropwise, followed by a reaction at 65°C for 6 hours. The resulting reaction solution was diluted with N-methyl-2-pyrrolidone (258.1 g), and the salt was removed by filtration. The resulting solution was then poured into methanol (4960 g). The precipitated solid was filtered off, washed with a small amount of methanol, and recovered by filtration again. The solid was then dried under reduced pressure at 80°C for 12 hours using a vacuum dryer, thereby obtaining a polymer (A9) represented by the following formula (9).

[0236]

[0237] The above formula indicates that polymer (A9) is a polymer having the above structural unit. In the above formula, * indicates bonding to any **, and polymer (A9) has a group represented by formula (Y) at the polymer terminal. The same applies to the following synthesis examples.

[0238] Synthesis Example 10 Polymer (A10) represented by the following formula (10) was obtained (yield: 121.50 g, yield: 88%) in the same manner as in Synthesis Example 9, except that the raw materials used were changed to 2,2-bis(3-methyl-4-hydroxyphenyl)propane (51.27 g), 4,4′,4″,4′″-(propane-2,2-diylbis(cyclohexane-4,1,1-triyl)tetraphenol (28.84 g), 4,6-dichloro-2-phenylpyrimidine (41.43 g), potassium carbonate (55.98 g), and chloromethylstyrene (49.15 g).

[0239]

[0240] Synthesis Example 11 Polymer (A11) represented by the following formula (11) was obtained by synthesis in the same manner as in Synthesis Example 9, except that the raw materials used were changed to 9,9-bis(4-hydroxy-3-methylphenyl)fluorene (56.77 g), α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (15.92 g), 4,6-dichloro-2-phenylpyrimidine (31.07 g), potassium carbonate (38.48 g), and chloromethylstyrene (28.91 g).

[0241]

[0242] Synthesis Example 12 Polymer (A12) represented by the following formula (12) was obtained in the same manner as in Synthesis Example 9, except that the raw materials used were changed to 2,2-bis(3-methyl-4-hydroxyphenyl)propane (64.09 g), 4,6-dichloro-2-phenylpyrimidine (31.08 g), 4,6-dichloropyrimidine (6.86 g), potassium carbonate (46.65 g), and chloromethylstyrene (22.01 g).

[0243]

[0244] [Comparative Polymer (a1)] Terminally modified polyphenylene ether (product name: Noryl TM SA9000 resin, manufactured by Sabic

[0245]

[0246] [Weight-average molecular weight (Mw) and number-average molecular weight (Mn)] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polymers (A1) to (A12) synthesized in Synthesis Examples 1 to 12 and polymer (a1) used in Comparative Example 1 below were measured using a GPC apparatus (manufactured by Tosoh Corporation, model number: "HLC-8320") under the following conditions. The results are shown in Table 1. Column: "TSKgel α-M" manufactured by Tosoh Corporation and "TSKgelguard column α" manufactured by Tosoh Corporation connected together Developing solvent: N-methyl-2-pyrrolidone Column temperature: 40°C Flow rate: 1.0 mL / min Sample concentration: 0.75% by mass Sample injection amount: 50 μL Detector: refractometer Standard substance: monodisperse polystyrene Measurement sample concentration: 0.1% by mass

[0247]

[0248] [Examples 1 to 21 and Comparative Examples 1 and 2] The components shown in Table 2 were mixed in a mixer rotor to the ratio (parts by mass) shown in the column for the blending ratio of the composition, and the concentration was adjusted with toluene (E1) to a solids concentration of 50 mass%, to prepare thermosetting resin compositions. Details of each component in Table 2 are as follows.

[0249] <Copolymers (B)> (B1): ethylene-styrene-1-octene-divinylbenzene copolymer (number average molecular weight: 22,000, content of structural units derived from aromatic vinyl compounds: 40% by mass) (B2): ethylene-styrene-divinylbenzene copolymer (number average molecular weight: 8,000, content of structural units derived from aromatic vinyl compounds: 48% by mass) (B3): ethylene-styrene-1-octene-divinylbenzene copolymer (number average molecular weight: 22,000, content of structural units derived from aromatic vinyl compounds: 60% by mass) (B4): ethylene-styrene-divinylbenzene copolymer (number average molecular weight: 8,000, content of structural units derived from aromatic vinyl compounds: 63% by mass) (b1): styrene-butadiene thermoplastic elastomer (product name: Tufprene (registered trademark) 912, manufactured by Asahi Kasei Corporation)

[0250] <Curable Compounds (C)> (C1): DVB960 (manufactured by Nippon Steel Chemical & Material Co., Ltd., divinylbenzene) (C2): Bis-(3-ethyl-5-methyl-4-maleimidophenyl)methane (product name: BMI-70, manufactured by K.I. Kasei Co., Ltd.) (C3): Triallyl isocyanurate (product name: manufactured by TAIC Shinryo Corporation (formerly MGC))

[0251] <Radical Polymerization Initiator (D)> (D1): Dicumyl peroxide (manufactured by NOF Corporation) (D2): 2,2'-Azobis(N-butyl-2-methylpropionamide) (product name: Vam-110, manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)

[0252] <Organic Solvent (E)> (E1): Toluene

[0253] <Filler (F)> (F1): Spherical silica (product name: FB-3SDC, manufactured by Denka Co., Ltd.) (F2): Spherical alumina (product name: DAW-05, manufactured by Denka Co., Ltd.)

[0254]

[0255] <Preparation of Cured Film> The compositions obtained in the above Examples and Comparative Examples were applied to copper foil (Model No. CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) using a Baker-type applicator (gap: 125 μm), then dried at 100° C. for 5 minutes and then at 140° C. for 5 minutes, and then baked under nitrogen at 200° C. for 2 hours. The obtained cured film with copper foil was immersed in a 40% by mass iron chloride solution, the copper foil was removed, washed with water, and dried in an oven at 80° C. for 30 minutes to prepare a cured film with a thickness of 50 μm.

[0256] <Glass Transition Temperature (Tg)> A test piece (width: 3 mm x length: 1 cm) was cut from the cured film prepared above, and measured using a dynamic viscoelasticity measuring device (Seiko Instruments Inc., model number: "EXSTAR4000") at a heating rate of 10°C / min and 1 Hz from 50°C to 300°C, and the tan δ measured here was taken as the glass transition temperature (Tg). When two or more tan δ values ​​were present, the lowest value was adopted as the Tg. The obtained Tg values ​​were evaluated according to the following evaluation criteria. When the evaluation criteria below were rated as "A" or "B," it can be said that the heat resistance was excellent.

[0257] -Evaluation criteria- Tg exceeding 180° C. was rated A, Tg exceeding 150° C. but not exceeding 180° C. was rated B, and Tg not exceeding 150° C. was rated C. The results are shown in Table 3.

[0258] <Peel Strength> Each of the compositions obtained in the above Examples and Comparative Examples was coated onto copper foil (model number: CF-V9S-SV, manufactured by Fukuda Metal Co., Ltd.), heated at 100°C for 5 minutes, and then dried at 130°C for 5 minutes to form a coating film. Copper foil (model number: CF-V9S-SV, manufactured by Fukuda Metal Co., Ltd.) was placed on the resulting coating film, vacuum pressed at 150°C for 5 minutes, and then baked at 200°C for 2 hours under nitrogen to produce a cured film with copper foil (copper foil: 18 μm, cured film: 10 μm), which was used as a sample for peel strength testing.

[0259] A test piece (width: 5 mm x length: 10 cm) was cut from the prepared peel strength sample, and using a universal testing machine (Instron Corporation, model number: "Instron 5567"), the test piece (one copper foil and cured film laminate in the peel strength sample) was pulled in a 90-degree direction at 500 mm / min. The peel strength was measured in accordance with "IPC-TM-650 (Test Method (Test Method Manual)) 2.4.9" and evaluated according to the following evaluation criteria. A rating of "A" or "B" in the following evaluation criteria indicates excellent adhesion.

[0260] -Evaluation criteria- A peel strength of 0.7 N / mm or more was rated "A", a peel strength of 0.5 N / mm or more but less than 0.7 N / mm was rated "B", and a peel strength of less than 0.5 N / mm was rated "C". The results are shown in Table 3.

[0261] <Dielectric loss tangent> A test piece (width: 6 cm x length: 6 cm) was cut out from the cured film prepared above, and the dielectric loss tangent of the test piece at 10 GHz was measured using a cavity resonator method (TE mode resonator, dielectric constant measurement system, manufactured by AET Corporation), and the dielectric loss tangent was evaluated according to the following evaluation criteria. When the evaluation criteria below are rated as "A" or "B," it can be said that the low dielectric loss tangent is excellent.

[0262] -Evaluation criteria- A dielectric loss tangent of less than 0.0015 was rated "A", a dielectric loss tangent of 0.0015 or more and less than 0.0025 was rated "B", and a dielectric loss tangent of 0.0025 or more was rated "C". The results are shown in Table 3.

[0263]

[0264] As shown in Table 3, the cured films of Examples 1 to 21 are superior to the cured films of Comparative Examples 1 and 2 in terms of the balance of heat resistance, adhesiveness, and low dielectric tangent.

Claims

1. A thermosetting resin composition for forming a wiring board, comprising: a polymer (A) having a structural unit represented by the following formula (1-1); and a copolymer (B) having a structural unit derived from ethylene or an α-olefin, a structural unit derived from an aromatic vinyl compound, and a structural unit derived from an aromatic polyfunctional vinyl compound. [In formula (1-1), R a1 is a divalent group represented by the following formula (2), R a2 is expressed by the following formula (R a2 −1), (R a2 −2) and (R a2 -3) is a divalent group represented by one selected from the following: [In formula (2), Ar a1 and Ar a2 are each independently an unsubstituted or substituted aromatic hydrocarbon group, and L is a single bond, -O-, -S-, -N(R 8 )-, -C(O)-, -C(O)-O-, -C(O)-NH-, -S(O)-, -S(O)2-, -P(O)- or a divalent organic group, 8 is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms; y is an integer of 0 to 5; when y is 2 or more, a plurality of Ar a1 and L are the same or different, R a6 and R a7 are each independently a single bond, a methylene group, or an alkylene group having 2 to 4 carbon atoms. [Formula (R a2 -1) to (R a2 -3) Medium, R 1 are each independently a halogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a nitro group, a cyano group, a primary to tertiary amino group, or a salt of a primary to tertiary amino group; each n is independently an integer of 0 to 2; when n is 2, multiple R 1 are the same or different and are combined together with the carbon atoms to which they are attached to form a ring structure having 5 to 10 ring members.

2. The thermosetting resin composition for forming a wiring board according to claim 1, wherein the number average molecular weight of the copolymer (B) is 500 or more and 100,000 or less.

3. A thermosetting resin composition for forming a wiring board as described in claim 1, wherein the aromatic vinyl compound in the copolymer (B) is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of structural units derived from the aromatic vinyl compound is more than 0 mass% and not more than 70 mass% when the mass of all structural units constituting the copolymer (B) is 100 mass%.

4. The thermosetting resin composition for forming a wiring board according to claim 1, wherein the α-olefin in the copolymer (B) is one or more α-olefins selected from α-olefins having 3 to 20 carbon atoms, and the total of the structural units derived from the ethylene or α-olefin, the structural units derived from an aromatic vinyl compound, and the structural units derived from an aromatic polyfunctional vinyl compound is 100 mass% based on the mass of all structural units of the copolymer (B).

5. The thermosetting resin composition for forming a wiring board according to claim 1, further comprising a curable compound (C) and an organic solvent (E).

6. The thermosetting resin composition for forming a wiring board according to claim 5, wherein the curable compound (C) is at least one compound selected from the group consisting of vinyl compounds, maleimide compounds, allyl compounds, acrylic compounds, methacrylic compounds, thiol compounds, oxazine compounds, cyanate compounds, epoxy compounds, oxetane compounds, methylol compounds, benzocyclobutene compounds, propargyl compounds, and silane compounds.

7. The thermosetting resin composition for forming a wiring board according to claim 1 or 5, further comprising a polymerization initiator (D).

8. The thermosetting resin composition for forming a wiring board according to claim 1 or 5, further comprising a filler (F).

9. A cured product comprising the thermosetting resin composition for forming a wiring board according to claim 1 or 5.

10. A prepreg obtained by impregnating a fibrous base material with the thermosetting resin composition for forming a wiring board according to claim 1 or 5.

11. A copper-clad laminate which is a laminate of the prepreg according to claim 10 and a copper substrate.

12. An interlayer insulating film comprising the thermosetting resin composition for forming a wiring board according to claim 1 or 5.

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