Resin composition, cured object, and electronic component

Abstract

One embodiment of the present invention pertains to a resin composition, a cured object, or an electronic component. The resin composition contains: a polymer (A) having a structural unit represented by formula (a1-1); and a hydrogenated styrene-based thermoplastic elastomer (B). In formula (a1-1), Ra1 represents a divalent group represented by formula (a2), and Ra2 represents a substituted or unsubstituted divalent aromatic heterocyclic group. In formula (a2), Ara1 and Ara2 each independently represent a substituted or unsubstituted aromatic hydrocarbon group, L represents a single bond, -O-, -S-, -N(R8)-, -C(O)-, -C(O)-O-, -C(O)-NH-, -S(O)-, -S(O)2-, -P(O)-, or a divalent organic group, y represents an integer of 0-5, and Ra6 and Ra7 each independently represent a single bond, a methylene group, or an alkylene group having 2-4 carbon atoms.

Description

Resin composition, cured product, and electronic component

[0001] One embodiment of the present invention relates to a resin composition, a cured product, or an electronic component.

[0002] In recent years, in the field of information and communications, the signal bands of information and communications devices have become increasingly higher in frequency in order to achieve high-speed, large-capacity transmission. To accommodate this higher frequency, there is an increasing demand for insulators used in printed wiring boards and semiconductor packages to have low dielectric constants and low dielectric loss tangents.

[0003] As materials that can accommodate this trend toward higher frequencies, polyolefin resin, styrene resin, fluororesin, polyphenylene ether resin, vinylbenzyl ether resin, or compositions using polyphenylene ether resin have been proposed (see, for example, Patent Documents 1 to 6).

[0004] Japanese Patent Application Laid-Open No. 7-188362 Japanese Patent Application Laid-Open No. 2004-83680 Japanese Patent No. 3414556 Japanese Patent Application Laid-Open No. 2003-306591 Japanese Patent No. 5649773 Japanese Patent Application Laid-Open No. 2017-200997

[0005] However, although conventional materials such as the compositions described in Patent Documents 1 to 6 have a low dielectric constant and a low dielectric loss tangent to some extent, there is room for improvement in terms of the balance between the low dielectric constant and the low dielectric loss tangent and the heat resistance.

[0006] One embodiment of the present invention provides a resin composition that can give a cured product that has a low dielectric constant, a low dielectric loss tangent, and excellent heat resistance, and an electronic component obtained from the cured product.

[0007] An example of the configuration of the present invention is as follows.

[0008] [1] A resin composition containing a polymer (A) having a structural unit represented by the following formula (a1-1) and a hydrogenated styrene-based thermoplastic elastomer (B):

[0009] [In formula (a1-1), R a1 is a divalent group represented by the following formula (a2), and R a2 is an unsubstituted or substituted divalent aromatic heterocyclic group. a1 and Ra2 It is different from

[0010] [In formula (a2), 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.

[0011] [2] R in the formula (a1-1) a2 is a divalent group selected from the following formulas (1-1), (1-2), and (1-3):

[0012] [In formulas (1-1) to (1-3), n is each independently an integer of 0 to 2, and when n is 1, R 1 are each independently a monovalent group, and when n is 2, two R 1 are the same or different monovalent groups, or two R 1 and together with the carbon atom to which they are bonded, form a ring structure having 5 to 10 ring members, and the monovalent group is 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.]

[0013] [3] The resin composition according to [1] or [2], wherein the hydrogenated styrene-based thermoplastic elastomer (B) is at least one selected from the group consisting of hydrogenated styrene-butadiene copolymers, hydrogenated styrene-butadiene-styrene block copolymers, hydrogenated styrene-isoprene block copolymers, and hydrogenated styrene-ethylene-butylene-styrene block copolymers.

[0014] [4] The resin composition according to any one of [1] to [3], wherein the content of structural units derived from styrene in the hydrogenated styrene-based thermoplastic elastomer (B) is 5 to 90 mass%.

[0015] [5] The resin composition according to any one of [1] to [4], further comprising a curable compound (C) other than the polymer (A) and the elastomer (B).

[0016] [6] A cured product of the resin composition according to any one of [1] to [5].

[0017] [7] An electronic component comprising the cured product according to [6].

[0018] According to one embodiment of the present invention, a resin composition is provided that can give a cured product having a low dielectric constant, a low dielectric dissipation factor, and excellent heat resistance (specifically, the ability to maintain a low dielectric dissipation factor even after heating). Also, according to one embodiment of the present invention, a resin composition is provided that can give a cured product having a good balance of low dielectric dissipation factor, heat resistance, a low coefficient of linear expansion, and adhesion to a metal layer (particularly a copper layer). Furthermore, according to one embodiment of the present invention, a resin composition is provided that can give a cured product having a low dielectric dissipation factor, a low elongation rate, a low coefficient of thermal expansion, and excellent heat resistance and tensile properties. These cured products are suitable for use in electronic components such as circuit boards, semiconductor packages, and display substrates.

[0019] Preferred embodiments of the present invention will be described in detail below. It should be understood that the present invention is not limited to the embodiments described below, but also includes various modifications that are implemented within the scope of the present invention. In this specification, a numerical range described using "to" means that the numerical values ​​before and after "to" are included as the lower and upper limits.

[0020] Resin Composition A resin composition according to one embodiment of the present invention (hereinafter also referred to as “the composition”) contains the following specific polymer (A) and a hydrogenated styrene-based thermoplastic elastomer (B).

[0021] <Polymer (A)> The polymer (A) has a structural unit represented by the following formula (a1-1): The polymer (A) may be used alone or in combination of two or more.

[0022] The content of the structural unit represented by formula (a1-1) in polymer (A) is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 60 mol% or more, and is preferably 99.5 mol% or less, more preferably 98 mol% or less, even more preferably 95 mol% or less.

[0023]

[0024] In formula (a1-1), R a1 is a divalent group represented by the following formula (a2), and R a2 is an unsubstituted or substituted divalent aromatic heterocyclic group. a1 and R a2 is different.

[0025] [R a1 〕 R a1 is a divalent group represented by the following formula (a2):

[0026]

[0027] In formula (a2), 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.

[0028] [Ar a1 and Ar a2 ] Ar a1 and Ar a2 The unsubstituted or substituted aromatic hydrocarbon group represented by the formula (I) is preferably an aromatic hydrocarbon group 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.

[0029] Ar a1 and Ar a2 Each of the aromatic hydrocarbon groups represented by Ar may have 1 to 8 substituents. a1 and Ar a2 The number of substituents possessed by the aromatic hydrocarbon group represented by the following formula (I) is preferably 0 to 8, more preferably 0 to 4, and even more preferably 0 to 2, from the viewpoint of enabling synthesis of polymer (A) with good polymerization reactivity, etc.

[0030] The Ar a1 and Ar a2The substituent on the aromatic hydrocarbon group represented by the formula (I) is not particularly limited, and examples thereof include an allyl group, a (meth)acryloyloxy 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, or a salt of a primary to tertiary amino group. Among these, an alkyl group having 1 to 10 carbon atoms is preferred as the substituent on the aromatic hydrocarbon group.

[0031] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0032] Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, and a monovalent aromatic hydrocarbon group.

[0033] 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.

[0034] Examples of the monovalent 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.

[0035] Examples of the monovalent aromatic hydrocarbon group include aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthryl; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, and naphthylmethyl.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] The substituent (R) in the secondary amino group (-NHR) and the tertiary amino group (-NR2) is not particularly limited, and examples thereof include monovalent hydrocarbon groups having 1 to 20 carbon atoms. Specific examples include the groups exemplified below as substituents in nitrogen-containing heteroaromatic rings.

[0040] 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:

[0041] [L] The divalent organic group for L is preferably an organic group having 1 to 20 carbon atoms, and examples thereof include an unsubstituted or substituted methylene group, an alkylene group having 2 to 20 carbon atoms, an arylene group having 6 to 10 carbon atoms, a group comprising a combination of two or more selected from the methylene group, the alkylene group, and the arylene group, or a group represented by the following formula (L1):

[0042]

[0043] In formula (L1), R c represents an unsubstituted or substituted divalent alicyclic hydrocarbon group having 5 to 30 ring members, a group represented by the following formula (L2), or a divalent group introduced by a compound represented by the following formula (L3) or formula (L4), etc.

[0044] [In formula (L2), * represents Ar in formula (a2)] a1 and Ar a2 represents a bond with

[0045]

[0046] 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.

[0047] Examples of the arylene group having 6 to 10 carbon atoms for L include a phenylene group, a methylphenylene group, and a naphthylene group.

[0048] In formula (L2), R 9 and R 10 are each independently a hydrogen atom, a fluorine atom, or a monovalent chain hydrocarbon group having 1 to 20 carbon atoms; and each k is independently an integer of 0 to 4.

[0049] R in the 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.

[0050] 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.

[0051] 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.

[0052] 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, and 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.

[0053] 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.

[0054] -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 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.

[0055] From the viewpoint of the structural stability of the polymer (A), L is preferably a single bond, —O—, —S—, —C(O)—, a substituted or unsubstituted methylene group, an alkylene group having 2 to 5 carbon atoms, or a group represented by the formula (L1).

[0056] [y] In formula (a2), y represents 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 3, and more preferably 0 or 1.

[0057] [R a6 and R a7 ] R a6 and R a7 Examples of the alkylene group having 2 to 4 carbon atoms in R 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.

[0058] R in formula (a1-1) a1 Examples of monomers that serve as raw materials for the moiety containing (i.e., the divalent group represented by formula (a2)) include compounds represented by the following formulas, as well as 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.

[0059]

[0060]

[0061]

[0062] [R a2 〕 R a2 is an unsubstituted or substituted divalent aromatic heterocyclic group. a1 and R a2 It is different from R a2 Examples of the unsubstituted or substituted divalent aromatic heterocyclic group represented by the formula (I) include a nitrogen-containing aromatic heterocyclic group, an oxygen-containing aromatic heterocyclic group, and a sulfur-containing aromatic heterocyclic group, and among these, a nitrogen-containing aromatic heterocyclic group is preferred.

[0063] Examples of the nitrogen-containing aromatic heterocyclic group 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. Among these, a pyrimidine ring is preferred from the viewpoints of enabling the synthesis of a polymer (A) with good polymerization reactivity and of easily obtaining a polymer (A) having excellent solubility in various organic solvents.

[0064] The positions of the two bonds (bonds bonded to O) bonded to the nitrogen-containing heteroaromatic ring are not particularly limited, but meta positions are preferred from the viewpoint of synthesizing the polymer (A) with good polymerization reactivity.

[0065] R a2 Examples of the substituents possessed by the divalent aromatic heterocyclic group represented by the formula (I) include 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 group in which a portion of these hydrocarbon groups or halogenated hydrocarbon groups is substituted with at least one atom selected from oxygen atoms and sulfur atoms, a nitro group, a cyano group, a maleimide group, a primary amino group, a tertiary amino group, or a salt of ... tertiary amino group. a1 Examples of the substituent that the aromatic hydrocarbon group represented by the following formula (I) has include the same groups as those exemplified above.

[0066] R a2The number of substituents that the divalent aromatic heterocyclic group represented by the following formula (I) has is preferably 0 to 2, from the viewpoint of enabling the synthesis of the polymer (A) with good polymerization reactivity.

[0067] R a2 is preferably a divalent group selected from the following formulae (1-1), (1-2) and (1-3):

[0068]

[0069] In formulas (1-1) to (1-3), n is each independently an integer of 0 to 2, and when n is 1, R 1 are each independently a monovalent group, and when n is 2, two R 1 are the same or different monovalent groups, or two R 1 and together with the carbon atoms to which they are bonded, form a ring structure having 5 to 10 ring members, and the monovalent group is 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. 1 Specific examples of each group in the above Ar a1 Examples of the substituent that the aromatic hydrocarbon group represented by the following formula (I) has include the same groups as those exemplified above.

[0070] R 1 From the viewpoint of improving the polymerization reactivity and the solubility of the resulting polymer (A), n is preferably a halogen atom, an alkyl group having 1 to 3 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and more preferably a fluorine atom, a chlorine atom, a methyl group, an ethyl group, or a phenyl group. From the same viewpoint, n is preferably 0 or 1, and more preferably 0.

[0071] In the divalent group represented by one kind selected from formulas (1-1), (1-2), and (1-3), the position of one bond relative to the other bond is preferably the meta position or the para position, more preferably the meta position, from the viewpoint of improving the polymerization reactivity.

[0072] In addition, from the viewpoint of improving the polymerization reactivity and improving the solubility in various organic solvents, R a2is preferably a group having a pyrimidine skeleton and represented by the formula (1-2).

[0073] The R a2 Examples of the monomers that can be used as raw materials for the portion containing the formula include 4,6-dichloropyrimidine, 4,6-dibromopyrimidine, 2,4-dichloropyrimidine, 2,5-dichloropyrimidine, 2,5-dibromopyrimidine, 5-bromo-2-chloropyrimidine, 5-bromo-2-fluoropyrimidine, 5-bromo-2-iodopyrimidine, 2-chloro-5-fluoropyrimidine, 2-chloro-5-iodopyrimidine, 2 -phenyl-4,6-dichloropyrimidine, 2-methylthio-4,6-dichloropyrimidine, 2-methylsulfonyl-4,6-dichloropyrimidine, 5-methyl-4,6-dichloropyrimidine, 2-amino-4,6-dichloropyrimidine, 5-amino-4,6-dichloropyrimidine, 2,5-diamino-4,6-dichloropyrimidine, 4-amino-2,6-dichloropyrimidine, 5-methoxy-4,6- Pyrimidine compounds such as dichloropyrimidine, 5-methoxy-2,4-dichloropyrimidine, 2-methyl-4,6-dichloropyrimidine, 6-methyl-2,4-dichloropyrimidine, 5-methyl-2,4-dichloropyrimidine, 5-nitro-2,4-dichloropyrimidine, 4-amino-2-chloro-5-fluoropyrimidine, 2-methyl-5-amino-4,6-dichloropyrimidine, and 5-bromo-4-chloro-2-methylthiopyrimidine; pyridazine compounds such as 3,6-dichloropyridazine, 3,5-dichloropyridazine, and 4-methyl-3,6-dichloropyridazine; and pyrazine compounds such as 2,3-dichloropyrazine, 2,6-dichloropyrazine, 2,5-dibromopyrazine, 2,6-dibromopyrazine, 2-amino-3,5-dibromopyrazine, and 5,6-dicyano-2,3-dichloropyrazine. These monomers may be used alone or in combination of two or more.

[0074] [Other structural units] The polymer (A) may have other structural units in addition to the structural unit represented by the formula (a1-1), if necessary. In this case, the structural units represented by the formula (a1-1) are bonded to each other or to the other structural units. When the polymer (A) has a plurality of structural units represented by the formula (a1-1), a plurality of R a1 may be the same or different. a2 The same is true for other structural units.

[0075] The other structural unit is not particularly limited, and examples thereof include a branched structural unit represented by the following formula (a1-2), a terminal group Y represented by the following formula (I), and any other structural unit.

[0076] [Branched structural unit] The polymer (A) may contain a branched structural unit represented by the following formula (a1-2) obtained by copolymerizing, in addition to the monomer that provides the structural unit of the above formula (a1-1), a monomer that provides a branched structure:

[0077]

[0078] In formula (a1-2), R a2 represents R in the formula (a1-1). a2 is synonymous with R 12 are each independently an unsubstituted or substituted divalent aromatic hydrocarbon group, R 13 is a hydrocarbon group having 1 to 20 carbon atoms, m is an integer of 1 to 6, and ** is a bond to another structural unit in the polymer (A).

[0079] Examples of the structural unit represented by formula (a1-2) include, but are not limited to, structural units having the following partial structures:

[0080]

[0081] The polymer (A) having the branched structural unit may be synthesized by synthesizing the structural unit represented by formula (a1-1) by removing the moiety (-R 12 -R 13 (R 12 -O-**)m -R 12 (-R 12 -R 13 (R 12 -O-**) m -R 12 Examples of the monomer that gives the formula (6) include compounds represented by the following formula (6):

[0082]

[0083] In the formula (6), R 13 is n having 1 to 20 carbon atoms 61 is a 2-valent hydrocarbon group, and R 61 are each independently 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, and n 61 is an integer from 2 to 4, and n 62 is an integer from 1 to 5, and n 63 is an integer from 0 to 4. 62 and 63 The total number of hydroxy groups is 1 to 5. In the compound represented by formula (6), the total number of hydroxy groups is 3 or more.

[0084] [Terminal Group] The polymer (A) may have a terminal group Y represented by the following formula (I) at the end of the structural unit represented by formula (a1-1).

[0085]

[0086] The terminal group Y is bonded to the main chain terminal of the polymer (A), and specifically forms the terminal portion of the polymer (A) represented by the following formula (a1-1-1) or (a1-1-2). a1 and R a2 The end (e.g., R a1 and R a2 is a group different from the group constituting the substituent in

[0087] [In formula (a1-1-1) and formula (a1-1-2), each Y is independently defined as Y in formula (I), and Z is O, S, or N(R Z ) and RZ is a hydrogen atom or Y, and R a1 and R a2 are each independently R in formula (a1-1). a1 and R a2 is equivalent to

[0088] In formula (I), Y is 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 aromatic heterocyclic group. Among these, a group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms is preferred. In order to improve dielectric properties, the terminal group Y is preferably an aromatic or aliphatic hydrocarbon group or a nitrogen-containing heteroaromatic group with low polarization, and when it further contains an ethylenically unsaturated double bond, crosslink density can be improved, and heat resistance and curability can be expected.

[0089] Examples of the group containing an ethylenically unsaturated double bond having 3 to 50 carbon atoms 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.

[0090] Examples of the aromatic hydrocarbon group having 6 to 50 carbon atoms 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.

[0091] Examples of the aliphatic hydrocarbon group having 6 to 50 carbon atoms 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.

[0092] Examples of the unsubstituted nitrogen-containing aromatic heterocyclic group include the R a2 Examples of the nitrogen-containing aromatic heterocyclic groups include the nitrogen-containing aromatic heterocyclic groups exemplified by

[0093] Specific examples of the substituents in the unsubstituted or substituted aromatic hydrocarbon group having 6 to 50 carbon atoms and the unsubstituted or substituted aliphatic hydrocarbon group having 6 to 50 carbon atoms include the above-mentioned R a2 Examples of the substituent include the groups exemplified as the substituent in the divalent aromatic heterocyclic group represented by the following formula:

[0094] The method for forming the polymer (A) in which the terminals of the polymer (A) are capped with the terminal group Y is not particularly limited, and any known method can be used. However, a method in which a monomer for forming the terminal group Y is used when synthesizing the polymer (A) is preferred.

[0095] Examples of the monomer for forming the terminal group Y include monohydric phenol compounds such as t-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.

[0096] [Optional structural unit] Examples of the monomer that derives the optional structural unit include 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; phosphine oxide compounds such as bis(fluorophenyl)phenylphosphine oxide, bis(fluorophenyl)naphthylphosphine oxide, and bis(fluorophenyl)anthrylphosphine oxide; and dicarboxylic acid dihalides such as phthalic acid dichloride, isophthalic acid dichloride, and terephthalic acid dichloride. These monomers may be used alone or in combination of two or more.

[0097] [Method for synthesizing polymer (A)] The method for synthesizing polymer (A) is not particularly limited, and known methods can be used. For example, a1 a monomer serving as a raw material for the portion containing R a2 The monomer that provides the other structural unit can be synthesized by heating the monomer that is the raw material for the portion containing R and, if necessary, the monomer that provides the other structural unit together with an alkali metal or an alkali metal compound in an organic solvent. a1 and a monomer serving as a raw material for the portion containing R a2 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.

[0098] Alkali Metal and Alkali Metal Compounds When a compound having a hydroxy group, such as a phenol compound, is used as a raw material in the synthesis of the 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.

[0099] 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.

[0100] 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.

[0101] The lower limit of the reaction temperature during the synthesis is preferably 50° C., more preferably 80° C., and the upper limit 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 is preferably 100 hours, more preferably 50 hours, and even more preferably 24 hours.

[0102] When the monomer for forming the terminal group Y is added after polymerization to cause a reaction in order to suppress gelation of the polymerization solution, the lower limit of the reaction temperature is preferably 0° C., more preferably 10° C., and the upper limit is preferably 130° C., more preferably 110° C. When the monomer for forming the terminal group Y is added after polymerization to cause a reaction, the lower limit of the reaction time is preferably 1 hour, more preferably 2 hours, and even more preferably 3 hours, and the upper limit is preferably 48 hours, more preferably 24 hours, and even more preferably 10 hours.

[0103] [Physical Properties of Polymer (A)] The lower limit of the polystyrene-equivalent weight average molecular weight (Mw) of polymer (A) is preferably 1,000, more preferably 2,000, particularly preferably 3,000, and the upper limit is preferably 500,000, more preferably 100,000, and even more preferably 30,000. When the Mw of polymer (A) is within the above range, a cured product having excellent adhesion to metal layers (especially copper layers) and heat resistance can be easily obtained, and a composition having a well-balanced excellent property such as impregnation into glass cloth and moldability such as resin flow can be easily obtained. The weight average molecular weight (Mw) is determined by gel permeation chromatography (GPC) under the conditions described in the Examples below.

[0104] [Content of Polymer (A)] The content of 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, and even more preferably 20 mass% or more, and is preferably 97 mass% or less, more preferably 90 mass% or less, and even more preferably 80 mass% or less. A content of polymer (A) within the above range is preferred from the viewpoint of further improving the adhesion to metal layers (particularly copper layers), heat resistance, curability, and electrical properties of the obtained cured product.

[0105] <Hydrogenated Styrenic Thermoplastic Elastomer (B)> The present composition contains a hydrogenated styrenic thermoplastic elastomer (B). The elastomer (B) is an elastomer in which some or all of the double bonds of a styrenic thermoplastic elastomer have been hydrogenated. By including the hydrogenated styrenic thermoplastic elastomer (B) in the present composition, a cured product with a lower dielectric constant and a lower dielectric loss tangent can be easily obtained. The elastomer (B) may be used alone or in combination of two or more types.

[0106] Examples of the elastomer (B) include hydrogenated styrene-based thermoplastic elastomers obtained by hydrogenating some or all of the carbon-carbon double bonds in copolymers such as styrene-butadiene copolymers, styrene-isoprene copolymers, etc. As the elastomer (B), at least one selected from the group consisting of hydrogenated styrene-butadiene copolymers, hydrogenated styrene-butadiene-styrene block copolymers, hydrogenated styrene-isoprene block copolymers, and hydrogenated styrene-ethylene-butylene-styrene block copolymers is preferred, since a cured product having a lower dielectric constant and a lower dielectric dissipation factor can be easily obtained.

[0107] The hydrogenation rate of the elastomer (B) is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, still more preferably 80% or more, and particularly preferably 90% or more. The hydrogenation rate is determined by measuring the iodine value of the elastomer (B).

[0108] The content of styrene-derived structural units in elastomer (B) (hereinafter also referred to as "styrene amount") is preferably 5 to 90% by mass, more preferably 10 to 80% by mass, and even more preferably 15 to 75% by mass. Using elastomer (B) with a styrene amount within the above range makes it easy to obtain a cured product that has a low dielectric constant, low dielectric loss tangent, heat resistance, a low coefficient of linear expansion, and adhesion to a metal layer (particularly a copper layer) in a well-balanced manner. Furthermore, when the styrene amount in elastomer (B) is within the above range, it tends to be possible to obtain a cured product that has a low dielectric loss tangent, low elongation, and low coefficient of thermal expansion, as well as a well-balanced excellent heat resistance and tensile properties. The styrene amount can be calculated from the proportion of styrene used in synthesizing elastomer (B), and can also be calculated from the ratio of styrene used in synthesizing elastomer (B) at 400 MHz. 1 It can be determined by measuring H-NMR.

[0109] The content of elastomer (B) in the composition is preferably 3 to 90% by mass, more preferably 5 to 70% by mass, even more preferably 5 to 60% by mass, even more preferably 5 to 50% by mass, and particularly preferably 5 to 40% by mass, based on 100% by mass of the combined solids of polymer (A) and elastomer (B). When the content of elastomer (B) is 3% by mass or more, a cured product with a lower dielectric constant and dielectric dissipation factor can be easily obtained. When the content of elastomer (B) is 90% by mass or less, the compatibility of elastomer (B) with other components in the composition is improved, allowing for sufficient dispersion, making it easy to obtain a cured product with excellent heat resistance and a low dielectric dissipation factor. Furthermore, when the content of elastomer (B) is within the above range, a cured product tends to be obtained that exhibits a good balance of low dielectric dissipation factor, heat resistance, a low coefficient of linear expansion, and adhesion to metal layers (especially copper layers), and / or a good balance of low dielectric dissipation factor, low elongation, and a low coefficient of thermal expansion, as well as excellent heat resistance and tensile properties.

[0110] <Other Components> The present composition contains the polymer (A) and the elastomer (B), and may further contain other components within the scope of not impairing the effects of the present invention.

[0111] Examples of the other components include a curable compound (C), a polymerization initiator (D), additives for imparting various functions (e.g., a filler (E), an antioxidant), an organic solvent (F), a polymerization inhibitor for increasing stability, a lubricant, and a foaming agent. Furthermore, the present composition may contain a thermoplastic resin as a polymer other than the polymer (A) and the elastomer (B) in order to adjust the physical properties of the composition, such as the fluidity, heat resistance, and electrical properties. Each of these other components may be used alone, or two or more types may be used.

[0112] [Curable Compound (C)] The present composition preferably further contains a curable compound (C). The curable compound (C) is a curable compound other than the polymer (A) and the elastomer (B), and is a compound that cures upon exposure to heat or light.

[0113] Examples of the curable compound (C) 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. In particular, from the viewpoint of compatibility with the polymer (A), reactivity, and the like, the curable compound (C) is preferably at least one compound selected from the group consisting of vinyl compounds, maleimide compounds, and allyl compounds.

[0114] When the present composition contains the curable compound (C), the content of the curable compound (C) is preferably 2 to 100 parts by mass, more preferably 5 to 75 parts by mass, and even more preferably 8 to 50 parts by mass, per 100 parts by mass of the total solid content of the polymer (A) and the elastomer (B). When the content of the curable compound (C) is within the above range, the toughness and heat resistance of the cured product obtained from the present composition can be further improved.

[0115] [Polymerization initiator (D)] The present composition preferably further contains a polymerization initiator (D). Examples of the polymerization initiator (D) include thermal or photoradical initiators, cationic curing agents, and anionic curing agents. Among these, thermal radical initiators are preferred as the polymerization initiator (D).

[0116] Examples of the thermal radical 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).

[0117] When the present composition contains a polymerization initiator (D), the content of the polymerization initiator (D) is preferably within a range in which the present composition is well cured to give a cured product. Specifically, the content of the polymerization initiator (D) is preferably at least 0.001 part by mass, more preferably at least 0.01 part by mass, and is preferably at most 20 parts by mass, more preferably at most 10 parts by mass, per 100 parts by mass of the total solid content of the polymer (A) and the elastomer (B).

[0118] [Additives] Examples of additives used to impart the various functions include fillers (E), antioxidants, flame retardants, adhesion aids, antibacterial agents, colorants, and mold release agents.

[0119] [Filler (E)] The present composition may further contain a filler (E). Examples of the filler (E) include organic fillers and inorganic fillers, with inorganic fillers being preferred. Examples of inorganic fillers 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, and M-glass G20.

[0120] When the present composition contains a filler (E), the content of the filler (E) is 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 elastomer (B).

[0121] [Organic Solvent (F)] The present composition preferably further contains an organic solvent (F). Examples of the organic solvent (F) include amide solvents, ester solvents, ketone solvents, ether solvents, sulfone solvents, hydrocarbon solvents such as benzene, toluene, and xylene, polyfunctional solvents such as 1-methoxy-2-propanol and propylene glycol methyl ether acetate, trialkoxybenzenes (alkoxy group having 1 to 4 carbon atoms), and methylene chloride.

[0122] When the composition contains an organic solvent (F), the content of the solvent (F) in the composition is not particularly limited and is, for example, preferably 0 to 2,000 parts by mass, more preferably 0 to 1,000 parts by mass, per 100 parts by mass of the total solid content of the polymer (A) and the elastomer (B). Furthermore, when the polymer (A) has high solubility in the organic solvent (F), the content of the organic solvent (F) in the composition may be 50 to 200 parts by mass.

[0123] <Method for preparing the present composition> The method for preparing the present composition is not particularly limited and may be any known method, for example, by uniformly mixing the polymer (A), the elastomer (B), and the other components. In this case, the order of mixing the components, the mixing conditions, etc. are not particularly limited, and a conventionally known mixer may be used for mixing.

[0124] <<Cured Product>> A cured product according to one embodiment of the present invention (hereinafter also referred to as the "present cured product") is a cured product of the present composition described above, and is obtained by curing the present composition described above. The present cured product may be, for example, a partially cured product of the present composition obtained by drying the solvent from the present composition. The method for curing the present composition described above is not particularly limited, and examples include a method in which the present composition is cured by heating. The heating conditions can be set, for example, at a temperature within a range of 100 to 250°C and for a time within a range of 10 to 120 minutes, depending on the desired degree of curing. The heating step for curing may be performed once, or may be performed in multiple steps with different temperatures or times.

[0125] The cured product has excellent heat resistance and can maintain a low dielectric constant and a low dielectric loss tangent even after heat is applied. Although the reason for this is not clear, it is thought that the cured product of the resin composition containing the polymer (A) and the elastomer (B) has excellent heat aging resistance because not only are the bond energies of the main chains and side chains of the polymer (A) and the elastomer (B) high, but also the number of unsaturated bonds remaining in the elastomer (B) is small.

[0126] The lower limit of the Tg of the cured product is preferably 150°C, more preferably 180°C, and the upper limit is, for example, 400°C. A Tg within this range makes melt molding easier and also makes it easier to obtain a cured product with excellent heat resistance. Specifically, the Tg can be measured by the method described in the examples below.

[0127] The dielectric loss tangent (tan δ) of the cured product is preferably less than 0.0025, more preferably 0.0018 or less, even more preferably 0.0015 or less, and particularly preferably less than 0.0015, 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 measured by the method described in the examples below.

[0128] The linear expansion coefficient of the cured product is preferably 50 ppm / K or less, more preferably 25 ppm / K or less, and even more preferably less than 25 ppm / K, from the viewpoint of easily obtaining a cured product that is less susceptible to deformation due to heat, etc. The linear expansion coefficient can be measured specifically by the method described in the examples below.

[0129] The cured product has an elongation of preferably 10 mJ or more, more preferably 15 mJ or more, and even more preferably 20 mJ or more, in terms of absorbed energy (mJ) calculated from the area value of a stress-strain curve measured using an EZ-LX tensile testing machine (manufactured by Shimadzu Corporation), in order to prevent cracking in the cured product or to prevent peeling of the cured product from the substrate by absorbing the strain energy when deformation such as expansion due to heat generated in an electronic component containing the cured product occurs, or when stress is applied to the substrate when a through-hole, via, or the like is formed.

[0130] From the viewpoint that it is preferable that the thermal expansion coefficient of the present cured product does not differ significantly from the expansion coefficient of surrounding materials (such as copper) when deformation such as expansion occurs due to heat generated in an electronic component containing the present cured product, the thermal expansion coefficient [α1 (ppm)] from 80 to 120°C upon cooling when the temperature is raised from room temperature to 200 to 250°C at a rate of 5°C / min using a TMA measurement device (Seiko Instruments Inc., Model SSC-5200) and then cooled to 0°C at a rate of 5°C / min is preferably 150 ppm or less, more preferably 130 ppm or less.

[0131] The chloride ion concentration in the cured product is preferably 5 ppm or less from the viewpoint of insulation reliability, and more preferably 3 ppm or less from the viewpoint of suppressing discoloration of copper wiring. When the cured product is used to form an interlayer insulating layer in contact with copper wiring, the cured product will be interposed between adjacent copper wiring. By setting the chloride ion concentration within the above range, diffusion of copper from copper wiring into the cured product is suppressed, and short-circuiting between wirings via the diffused copper is suppressed, resulting in significantly improved insulation reliability of the laminate including the wiring. The chloride ion concentration can be measured, for example, by the following procedure. The cured product and ultrapure water as an extract are placed in a Teflon (registered trademark) heat-resistant container and heated, and the extract is then filtered and analyzed by ion chromatography.

[0132] The shape of the cured product is not particularly limited, and a suitable shape can be selected depending on the application, purpose, etc. Examples of the shape of the cured product include a film, a plate, and a rod. For example, a film-like cured product can be obtained by melt molding or cast molding the composition.

[0133] The thickness of the present cured product is not particularly limited and may be appropriately selected depending on the desired application. When the present cured product is in the form of a film, its 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.

[0134] The present cured product may be a laminate including the cured product (cured product layer) and a substrate. The laminate may be a prepreg obtained by impregnating a substrate such as glass cloth, aramid nonwoven fabric, or polyester nonwoven fabric with the present composition and curing the resulting prepreg. The laminate may also be, for example, a copper-clad laminate, which is a laminate of the prepreg and a copper substrate. The laminate may have two or more substrate layers, two or more cured product layers, or a conventionally known layer other than the substrate and the cured product layer. When the laminate has two or more substrate layers, cured product layers, or other layers, these may be the same layer (plate) or different layers (plates).

[0135] Examples of the substrate include inorganic substrates, metal substrates, and resin substrates, from the viewpoint of adhesiveness to the cured product and practicality. The substrate may also be a prepreg. 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, metal foil, or the like. Examples of the resin substrate include resin substrates containing liquid crystal polymers, polyimides, polyphenylene sulfide, polyether ether ketone, polyamide (nylon), polyethylene terephthalate, polyethylene naphthalate, cycloolefin polymers, polyolefins, etc.

[0136] The cured layer can be formed, for example, by curing the present composition. The thickness of the cured layer is not particularly limited, but is, for example, 1 μm to 3 mm.

[0137] <Applications> The present composition and the present cured product can be suitably used as structural materials used in the transportation industry, such as the aircraft industry and the automobile industry, and as electrical and electronic materials used in the electrical and electronics industry. Specific examples include sealing materials for electrical and electronic components, interlayer insulating films, and stress relaxation primers; laminate applications (e.g., prepregs, copper-clad laminates, (multilayer) printed wiring boards, interlayer adhesives, solder resists, and solder pastes); adhesive applications (e.g., adhesive sheets for forming insulating layers, thermally conductive adhesives, and 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, and lens arrays); and insulating films for printed wiring boards. In particular, interlayer insulating films made from the cured product have a low dielectric tangent, excellent adhesion to metal layers (e.g., copper layers), and excellent heat resistance.

[0138] <Electronic Component> An electronic component according to one embodiment of the present invention includes the present cured product. The electronic component may include two or more present cured products. When two or more present cured products are included, these may be the same or different.

[0139] Examples of the electronic components include circuit boards, semiconductor packages, and display substrates. The present 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 present cured product can maintain its insulating properties even under high temperature and high humidity conditions, electronic components equipped with the present 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.

[0140] 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.

[0141] Hereinafter, one embodiment of the present invention will be described more specifically based on examples, but the present invention is not limited to these examples in any way.

[0142] Synthesis Example 1 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (20.3 g, 60.0 mmol), 2,5-di-t-butylhydroquinone (8.9 g, 40.0 mmol), 4,6-dichloropyrimidine (14.9 g, 100.0 mmol), and potassium carbonate (18.7 g, 135.0 mmol) were weighed into a four-neck separable flask equipped with a stirrer, and N-methyl-2-pyrrolidone (102.9 g) was added, followed by reaction for 6 hours at 130° C. under a nitrogen atmosphere. After completion of the reaction, the mixture was diluted with N-methyl-2-pyrrolidone (206 g), and 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 a structural unit represented by the following formula (1):

[0143]

[0144] Synthesis Example 2 1,1-bis(4-hydroxy-3-methylphenyl)-3,3,5-trimethylcyclohexane (25.4 g, 75.0 mmol), 4,6-dichloropyrimidine (11.2 g, 75.0 mmol), and potassium carbonate (14.0 g, 101.3 mmol) 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 completion of the reaction, 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):

[0145]

[0146] Synthesis Example 3: 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (62.08 g), 4,6-dichloropyrimidine (30.99 g), 4-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):

[0147]

[0148] 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 flask while it was 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).

[0149]

[0150] 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), 4-isopropenylphenol (7.83 g), 4,6-dichloro-2-phenylpyrimidine (51.51 g), and potassium carbonate (35.93 g).

[0151]

[0152] 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 to the flask 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).

[0153]

[0154] 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, alkali metal compound, and organic solvent 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-(chloromethyl)styrene (8.680 g), potassium carbonate (18.66 g), and N-methyl-2-pyrrolidone (42.50 g).

[0155]

[0156] 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).

[0157]

[0158] 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, m,p-(chloromethyl)styrene (38.55 g) was added dropwise with the flask cooled to 10°C, and the mixture was reacted 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).

[0159]

[0160] The formula indicates that polymer (A9) is a polymer having the structural unit. In the 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.

[0161] Synthesis Example 10 Polymer (A10) represented by the following formula (10) was obtained by the same procedure as in Synthesis Example 9, except that the raw materials and alkali metal compound 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 m,p-(chloromethyl)styrene (49.15 g).

[0162]

[0163] Synthesis Example 11 Polymer (A11) represented by the following formula (11) was obtained by synthesizing in the same manner as in Synthesis Example 9, except that the raw materials and alkali metal compound 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 m,p-(chloromethyl)styrene (28.91 g).

[0164]

[0165] Synthesis Example 12 Polymer (A12) represented by the following formula (12) was obtained by synthesizing in the same manner as in Synthesis Example 9, except that the raw materials and alkali metal compound 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 m,p-(chloromethyl)styrene (22.01 g).

[0166]

[0167] [Comparative Polymer (ca1)] Terminally modified polyphenylene ether (product name: Noryl SA9000 resin, manufactured by Sabic, a polymer represented by the following formula (ca1))

[0168] (The above Y does not include an aromatic heterocyclic structure.)

[0169] [Comparative polymer (ca2)] Maleimide compound (product name: BMI-3000, manufactured by Designer Molecules)

[0170] [Comparative Polymer (ca3)] Copolymer A having structural units derived from monomers (i) to (iii) represented by the following formula, as described in Example 1 of WO 2018 / 181842, was synthesized. It was confirmed that a copolymer equivalent to that of Example 1 was obtained by the method described in this example. The obtained copolymer was designated comparative polymer (ca3).

[0171]

[0172] [Weight-average molecular weight (Mw) and number-average molecular weight (Mn)] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polymers (A1) to (A12) and comparative polymers (ca1) to (ca3) synthesized in Synthesis Examples 1 to 12 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 volume: 50 μL Detector: refractometer Standard substance: monodisperse polystyrene Measurement sample concentration: 0.1% by mass

[0173]

[0174] [Examples 1 to 28 and Comparative Examples 1 to 4] Resin compositions were prepared by mixing the components shown in Table 2 in the ratios (parts by mass) shown in the column for the blending ratio of the composition using a mix rotor, and adjusting the concentration with toluene to the solids concentration shown in Table 2 for each test example. Note that "-" in Table 2 means that the corresponding component was not included.

[0175]

[0176] The details of each component in Table 2 are as follows: <Hydrogenated styrene-based thermoplastic elastomer (B)> Hereinafter, the term "styrene amount" refers to the content of structural units derived from styrene in the hydrogenated styrene-based thermoplastic elastomer (B). (B1): Tuftec H1517 (hydrogenated styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation, styrene content: 43% by mass) (B2): Tuftec H1062 (hydrogenated styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation, styrene content: 18% by mass) (B3): Tuftec H1041 (hydrogenated styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation, styrene content: 30% by mass) (B4): Tuftec H1043 (hydrogenated styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation, styrene content: 67% by mass) (B5): Tuftec M1913 (carboxylic acid-modified hydrogenated styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation, styrene content: 30% by mass) (B6): S.O.E. S1605 (hydrogenated styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation, styrene content: 67% by mass) (B7): Dynaron 8903P (hydrogenated styrene-butadiene copolymer resin, manufactured by ENEOS Materials Corporation, styrene content: 35% by mass) (B8): Kraton A1535 (hydrogenated styrene-butadiene copolymer resin, manufactured by KRATON Co., styrene content: 57% by mass) (B9): Septon V9461 (hydrogenated styrene-4-methylstyrene-isoprene-butadiene copolymer resin having styryl groups, manufactured by Kuraray Co., Ltd., styrene content: 30% by mass) (B10): Tuftec P1500 (selectively hydrogenated styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation, styrene content: 30% by mass) (B11): Tuftec MP10 (amine-modified selectively hydrogenated styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation, styrene content: 30% by mass); (B12): Dynaron 2324P (hydrogenated styrene-butadiene copolymer resin, manufactured by ENEOS Materials Corporation, styrene content: 16% by mass); (b1): Tufprene 912 (styrene-butadiene copolymer resin, manufactured by Asahi Kasei Corporation).

[0177] <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. Chemical Co., Ltd.) (C3): triallyl isocyanurate (product name: TAIC, manufactured by Mitsubishi Chemical Group Corporation)

[0178] <Radical Polymerization Initiator (D)> (D1): Dicumyl peroxide (manufactured by NOF Corporation)

[0179] Preparation of Cured Film (P) The polymers synthesized in Synthesis Examples 1 to 12 or comparative polymers ca1 to ca3 were mixed with dicumyl peroxide in a mass ratio of 99.5:0.5 using a mixer rotor, and the concentration was adjusted with toluene to a solids concentration of 50 mass% to prepare varnishes (resin compositions) (varns A1 to A12, varnishes a1 to a3). The resulting varnishes were applied to copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metal Foil & Powder Co., Ltd.) using a Baker applicator (gap: 125 μm), dried at 100°C for 5 minutes, then at 140°C for 5 minutes, and then baked at 200°C for 2 hours under nitrogen. The obtained cured film with the copper foil was immersed in a 40% by mass iron chloride solution, the copper foil was removed, and then the film was washed with water and dried in an oven at 80°C for 30 minutes to produce a cured film (P) with a thickness of 50 µm.

[0180] <Preparation of Cured Film (C)> The compositions obtained in the above Examples and Comparative Examples were applied to copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metal Foil & Powder Co., Ltd.) using a Baker-type applicator (gap: 125 μm), followed by drying at 100°C for 5 minutes and then at 140°C for 5 minutes, and then baking 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 produce a 50 μm-thick cured film (C).

[0181] <Dielectric Loss Tangent (Df)> Test specimens (width: 6 cm × length: 6 cm) were cut out from the cured films (P) and (C) prepared above, and the dielectric loss tangent (Df) of the test specimens at 10 GHz was measured using a cavity resonator method (manufactured by AET Corporation, dielectric constant measurement system, TE mode resonator).

[0182] <Electrical Properties (ΔDf)> ΔDf, expressed by the following formula where Df of cured film (C) is Df(C) and Df of cured film (P) is Df(P), was evaluated according to the following criteria. The results are shown in Table 3. Note that Df(P) in the formula below is the Df of cured film (P) obtained using the same polymer as the polymer in the composition obtained in each Test Example, which was the raw material of cured film (C) used to measure Df(C). For example, when Df(C) in the formula below is the Df of cured film (C) obtained using the composition obtained in Example 1, Df(P) in the formula below is the Df of cured film (P) obtained using polymer (A1) obtained in Synthesis Example 1. ΔDf=Df(P)-Df(C)

[0183] -Evaluation criteria- A: ΔDf>0.0003 B: 0≦ΔDf≦0.0003 C: ΔDf<0

[0184] <Heat Resistance (ΔDf150)> The cured film (C) obtained above was heat-treated in an oven at 150°C (in air) for 500 hours, and the dielectric loss tangent (Df) of the film was measured before and after the heat treatment in the same manner as in the method for measuring the dielectric loss tangent (Df) described above. The dielectric loss tangent before the heat treatment was designated Df(t0) and the dielectric loss tangent after the heat treatment was designated Df(t1). From the change in the dielectric loss tangent before and after the heat treatment, the heat resistance (ΔDf150) was calculated according to the following formula and evaluated according to the following criteria. The results are shown in Table 3. ΔDf150 = Df(t1) - Df(t0)

[0185] -Evaluation criteria- A: ΔDf150<0.0010 B: 0.0010≦ΔDf150<0.0100 C: 0.0100≦ΔDf150<0.0200

[0186]

[0187] As shown in Table 3, it can be seen that the cured films of Examples 1 to 28 have a lower dielectric tangent and are superior in heat resistance compared to the cured films of Comparative Examples 1 to 4.

[0188] [Examples 29 to 32] The polymer (A), the hydrogenated styrene-based thermoplastic elastomer (B), the radical polymerization initiator (D), and the filler (E) were mixed using a mix rotor to obtain the ratio (parts by mass) shown in Table 4, and the concentration was adjusted with toluene to give a solids concentration of 60 mass%, thereby preparing resin compositions.

[0189]

[0190] Details of the filler (E) in Table 4 are as follows: <Filler (E)> (E1): Fused spherical silica "GT grade" (manufactured by Denka Co., Ltd., average particle size: 3 μm)

[0191] <Preparation of Cured Films> Cured films having a thickness of 50 μm were prepared in the same manner as in Example 1, except that the compositions obtained in Examples 29 to 32 were used.

[0192] <Dielectric Loss Tangent> A test specimen (width: 6 cm x length: 6 cm) was cut out from the cured film prepared above, and the dielectric loss tangent of the test specimen 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. The results are shown in Table 5. A rating of "A" or "B" in the following evaluation criteria can be said to be a low dielectric loss tangent.

[0193] -Evaluation Criteria- A dielectric loss tangent of less than 0.0015 was rated "A", a dielectric loss tangent of 0.0015 or more but less than 0.0025 was rated "B", and a dielectric loss tangent of 0.0025 or more was rated "C".

[0194] <Glass Transition Temperature (Tg)> A test piece (width: 3 mm x length: 1 cm) was cut from the cured film prepared above, and the dynamic viscoelasticity was measured at a frequency of 1 Hz using a dynamic viscoelasticity measuring device (manufactured by Seiko Instruments Inc., model number: "EXSTAR4000") as the temperature was increased from 50°C to 300°C at a heating rate of 10°C / min, 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 was evaluated according to the following evaluation criteria. The results are shown in Table 5. A rating of "A" or "B" in the following evaluation criteria can be said to indicate excellent heat resistance.

[0195] -Evaluation Criteria- Tg exceeding 180°C was rated "A", Tg between 150°C and 180°C was rated "B", and Tg below 150°C was rated "C".

[0196] <Coefficient of Linear Expansion (CTE)> Test specimens (width: 3 mm × length: 2 cm) were cut from the cured films prepared above, and the coefficient of linear expansion of the test specimens was measured using an SSC-5200 TMA measuring device (manufactured by Seiko Instruments Inc.). The test specimens were heated from room temperature to 260°C at a rate of 5°C / min, and then further heated at 260°C for 10 minutes to remove any remaining solvent and to remove molding strain. The specimens were then allowed to cool to 40°C and stabilize at that temperature for 30 minutes. After this, a scan measurement was performed from 40°C to 260°C at a heating rate of 5°C / min, and the coefficient of linear expansion (CTE) was calculated from the dimensional change from 80 to 120°C. The obtained coefficient of linear expansion (CTE) was evaluated according to the following evaluation criteria. The results are shown in Table 5. A rating of "A" or "B" in the following evaluation criteria indicates a low coefficient of linear expansion.

[0197] -Evaluation Criteria- A CTE of less than 25 ppm / K was rated "A", a CTE of 25 ppm / K to 50 ppm / K was rated "B", and a CTE of more than 50 ppm / K was rated "C".

[0198] <Peel Strength> Each of the compositions obtained in Examples 29 to 32 was applied to copper foil (model number: CF-V9S-SV, manufactured by Fukuda Metal Foil & Powder 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 Foil & Powder 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 (each copper foil thickness: 18 μm, cured film thickness: 10 μm), which was used as a sample for peel strength testing.

[0199] A test piece (width: 5 mm x length: 10 cm) was cut from the peel strength sample prepared above, and using a universal testing machine (manufactured by Instron, model number: "Instron 5567"), the test piece (one copper foil and cured film laminated portion 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. The results are shown in Table 5. A rating of "A" or "B" in the following evaluation criteria indicates excellent adhesion to copper foil.

[0200] -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".

[0201]

[0202] As shown in Table 5, the cured films obtained in Examples 29 to 32 were found to have a well-balanced low dielectric tangent, heat resistance, low coefficient of linear expansion, and excellent adhesion to metal layers (particularly copper layers).

[0203] [Examples 33 to 41 and Comparative Examples 5 and 6] Resin compositions were prepared by mixing the components shown in Table 6 in the ratios (parts by mass) shown in the column for the blending ratio of the composition using a mix rotor, and adjusting the concentration with toluene to the solids concentration shown in Table 6 for each test example. Note that "-" in Table 6 means that the corresponding component was not included.

[0204]

[0205] <Preparation of Cured Film> Each of the compositions obtained in Examples 33 to 41 and Comparative Examples 5 and 6 was applied to copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metal Co., Ltd.) using a Baker-type applicator (gap: 125 μm), heated at 100°C for 5 minutes, and then dried at 140°C for 5 minutes to form a coating film. Copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metal Co., Ltd.) was placed on the resulting coating film, vacuum pressed at 160°C for 10 minutes, and then baked at 200°C for 2 hours under nitrogen to prepare a cured film with copper foil (copper foil: 18 μm, cured film 100±25 μm). The prepared cured film with the copper foil was immersed in a 40% by mass iron chloride solution, the copper foil was removed, and then the film was washed with water and dried in an oven at 80°C for 30 minutes to prepare a cured film with a thickness of 100±25 μm.

[0206] <Dielectric Dissipation Factor (Df)> Test specimens (width: 6 cm x length: 6 cm) were cut out from the cured films prepared above, and the dielectric dissipation factor (Df) of the test specimens at 10 GHz was measured using a cavity resonator method (TE mode resonator, dielectric constant measurement system, manufactured by AET Corporation), and evaluated according to the following criteria. The results are shown in Table 7. A rating of "3" to "5" on the following criteria can be said to be a low dielectric dissipation factor, and is within the practically acceptable range.

[0207] -Evaluation criteria- 3: 0.0020≦Df<0.0025 4: 0.0015≦Df<0.0020 5: Df<0.0015

[0208] <Heat Resistance (ΔDf150)> The cured film obtained above was subjected to the same heat treatment and measurement as in Example 1 for evaluating heat resistance (ΔDf150). The dielectric dissipation factor before the heat treatment was Df(t0) and the dielectric dissipation factor after the heat treatment was Df(t1). The heat resistance (ΔDf150) was calculated from the change in the dielectric dissipation factor before and after the heat treatment using the following formula, and evaluated according to the following criteria. The results are shown in Table 7. ΔDf150=Df(t1)-Df(t0)

[0209] -Evaluation criteria- 3: 0.0100≦ΔDf150<0.0200 4: 0.0010≦ΔDf150<0.0100 5: ΔDf150<0.0010

[0210] <Glass Transition Temperature (Tg)> Test pieces (width: 3 mm × length: 1 cm) were cut from the cured films prepared above, and the dynamic viscoelasticity was measured at a frequency of 1 Hz using a dynamic viscoelasticity measuring device (manufactured by Seiko Instruments Inc., model number: "EXSTAR4000") as the temperature was increased from 50°C to 300°C at a heating rate of 10°C / min. The tan δ measured here was taken as the glass transition temperature (Tg) and evaluated according to the following criteria. The results are shown in Table 7. When two or more tan δ values ​​were present, the lowest value was taken as Tg. A rating of "4" or "5" on the following evaluation criteria can be said to indicate excellent heat resistance.

[0211] -Evaluation criteria- 3: Tg≦150°C 4: 150°C<Tg≦180°C 5: 180°C<Tg

[0212] <Elongation> The compositions obtained in Examples 33 to 41 and Comparative Examples 5 and 6 were applied to copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) using a Baker-type applicator (gap: 125 μm), heated at 100°C for 5 minutes, and then dried at 140°C for 5 minutes to form a coating film. Copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metals Co., Ltd.) was placed on the resulting coating film, vacuum pressed at 160°C for 10 minutes, and then baked at 200°C for 2 hours under nitrogen to produce a copper foil-attached cured film (copper foil: 18 μm, cured film 100±25 μm). The prepared copper foil-attached cured film was immersed in a 40% by mass iron chloride solution, the copper foil was removed, and the film was washed with water and dried at 80°C for 30 minutes to prepare a film for elongation measurement. The elongation of the prepared elongation measurement film was measured using a TMA measuring device (Seiko Instruments Inc., SSC-5200 model). At this time, the temperature of the elongation measurement film was raised from room temperature to 300°C at a rate of 5°C / min, and the elongation of the film from the initial temperature (room temperature) to 260°C was calculated and evaluated according to the following criteria. The results are shown in Table 7. Note that a rating of "3" to "5" on the following criteria can be said to be within a practically acceptable range, and a rating of "4" or "5" on the following criteria can be said to be a low elongation. Elongation (%) = (length of test piece at 260°C - length of test piece at initial temperature (room temperature)) / length of test piece at initial temperature (room temperature) × 100

[0213] -Evaluation criteria- 2: 30% < elongation 3: 15% < elongation ≦ 30% 4: 7% < elongation ≦ 15% 5: elongation ≦ 7%

[0214] <Coefficient of Thermal Expansion (α1)> Test specimens (width: 0.3 cm × length: 2 cm) were cut out from the cured film prepared above to prepare films for evaluation. The elongation of the evaluation films was measured using a TMA measuring device (Seiko Instruments Inc., SSC-5200). The evaluation films were heated from room temperature to 200-250°C at a rate of 5°C / min, and then cooled to 0°C at a rate of 5°C / min. The coefficient of thermal expansion [α1 (ppm)] from 80-120°C upon cooling was determined and evaluated according to the following evaluation criteria. The results are shown in Table 7. A rating of "4" or "5" on the following evaluation criteria can be considered to indicate a low coefficient of thermal expansion.

[0215] -Evaluation criteria- 2: 170 ppm < α1 3: 150 ppm < α1 ≦ 170 ppm 4: 130 ppm < α1 ≦ 150 ppm 5: α1 ≦ 130 ppm

[0216] <Tensile elongation: absorbed energy> Each of the compositions obtained in Examples 33 to 41 and Comparative Examples 5 and 6 was applied to copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metal Co., Ltd.) using a Baker-type applicator (gap: 125 μm), heated at 100° C. for 5 minutes, and then dried at 140° C. for 5 minutes to form a coating film. Copper foil (model number: CF-T49A-DS-HD2, manufactured by Fukuda Metal Co., Ltd.) was placed on the resulting coating film, vacuum pressed at 160° C. for 10 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: 100±25 μm). The prepared cured film with copper foil was immersed in a 40% by mass iron chloride solution, and after removing the copper foil, the film was washed with water and dried at 80°C for 30 minutes to prepare a 100±25 μm thick film for absorbed energy measurement. The stress-strain curve of the prepared film for absorbed energy measurement was measured using an EZ-LX tensile testing machine (manufactured by Shimadzu Corporation). The absorbed energy (mJ) was calculated from the area value of the obtained stress-strain curve and evaluated according to the following criteria. The results are shown in Table 7. A rating of "3" to "5" on the following criteria can be considered to be within a practically acceptable range, and a rating of "4" or "5" on the following criteria can be considered to have a sufficiently large tensile elongation. A film with a large tensile elongation can be considered to have a high absorbed energy and excellent tensile properties.

[0217] -Evaluation criteria- 2: 5 mJ≦absorbed energy<10 mJ 3: 10 mJ≦absorbed energy<15 mJ 4: 15 mJ≦absorbed energy<20 mJ 5: 20 mJ≦absorbed energy

[0218]

[0219] As shown in Table 7, the cured films of Examples 33 to 41 have a lower dielectric tangent, lower elongation, and lower thermal expansion coefficient than the cured films of Comparative Examples 5 and 6, and are excellent in a well-balanced manner in heat resistance and tensile properties.

Claims

1. A resin composition comprising a polymer (A) having a structural unit represented by the following formula (a1-1) and a hydrogenated styrene-based thermoplastic elastomer (B): In formula (a1-1), R a1 is a divalent group represented by the following formula (a2), R a2 is an unsubstituted or substituted divalent aromatic heterocyclic group, a1 and R a2 is different from; In formula (a2), 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.

2. R in the above formula (a1-1) a2 is a divalent group selected from the following formulas (1-1), (1-2), and (1-3): In formulas (1-1) to (1-3), n is each independently an integer of 0 to 2. When n is 1, R 1 are each independently a monovalent group, and when n is 2, two R 1 are the same or different monovalent groups, or two R 1 and form a ring structure having 5 to 10 ring members together with the carbon atom to which they are bonded, and the monovalent group is 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.

3. The resin composition according to claim 1, wherein the hydrogenated styrene-based thermoplastic elastomer (B) is at least one selected from the group consisting of hydrogenated styrene-butadiene copolymers, hydrogenated styrene-butadiene-styrene block copolymers, hydrogenated styrene-isoprene block copolymers, and hydrogenated styrene-ethylene-butylene-styrene block copolymers.

4. The resin composition according to claim 1, wherein the content of structural units derived from styrene in the hydrogenated styrene-based thermoplastic elastomer (B) is 5 to 90 mass %.

5. The resin composition according to claim 1, further comprising a curable compound (C) other than the polymer (A) and the elastomer (B).

6. A cured product of the resin composition according to claim 1.

7. An electronic part comprising the cured product according to claim 6.

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