Compound, resin composition, prepreg, resin film, metal-clad laminate, printed wiring board, and semiconductor package

Abstract

One embodiment of the present invention relates to a compound comprising an indene ring, a vinylbenzyl group, and an aromatic ring-containing group having 6 or more carbon atoms and not having a polymerizable carbon-carbon double bond, the vinylbenzyl group and the aromatic ring-containing group being each directly bonded to the indene ring.

Description

Compound, resin composition, prepreg, resin film, metal-clad laminate, printed wiring board, and semiconductor package

[0001] The present disclosure relates to a compound, a resin composition, a prepreg, a resin film, a metal-clad laminate, a printed wiring board, and a semiconductor package.

[0002] Metal-clad laminates, such as copper-clad laminates, prepregs that can be used with metal-clad laminates, and semiconductor packages that use metal-clad laminates are used in a variety of electronic devices, including mobile communication devices such as smartphones, their base station equipment, servers, routers, large servers, and other network infrastructure devices, as well as large computers, personal computers, and industrial computers. They are also used in electronic devices installed in home appliances, automobiles, and other devices. With the spread of 5G, there is a growing demand for electronic communication devices to process massive amounts of data at high speeds.

[0003] When electronic devices process huge amounts of data at high speed, they require circuit board materials with low transmission loss in the high-frequency range. While resins with low dielectric constants and low dielectric loss tangents are used as circuit board materials and provide circuit boards with low transmission loss, recent advances in communication technology have created a demand for the development of resins with even lower dielectric constants and dielectric loss tangents.

[0004] Patent Document 1 discloses a compound having an indene ring structure into which a vinylbenzyl group has been introduced, as a curable vinylbenzyl compound that can give a cured product excellent in low dielectric constant, low dielectric dissipation factor, high heat resistance, and low water absorption.

[0005] Japanese Patent Application Laid-Open No. 2003-277440

[0006] An object of the present disclosure is to provide a compound that can be used to produce a cured product in which deterioration of dielectric properties due to moisture absorption is suppressed, as well as a resin composition, a prepreg, a resin film, a metal-clad laminate, a printed wiring board, and a semiconductor package that use the compound.

[0007] Examples of embodiments are listed below. The present invention is not limited to the following embodiments. One embodiment relates to a compound comprising an indene ring, a vinylbenzyl group, and an aromatic ring-containing group having 6 or more carbon atoms and no polymerizable carbon-carbon double bond, wherein the vinylbenzyl group and the aromatic ring-containing group are each directly bonded to the indene ring. Another embodiment relates to a compound represented by the following formula (1): (In formula (1), R １ ~R ４ R each independently represents a hydrogen atom or a monovalent substituent. １ , R ２ and R ３ At least one of R is a vinylbenzyl group; １ , R ２ and R ３ At least one of the four R is an aromatic ring-containing group having 6 or more carbon atoms and not having a polymerizable carbon-carbon double bond. ４ may all be different from each other, and four R ４ Two or more of these may be the same.) Another embodiment relates to a resin composition containing any of the above compounds. Another embodiment relates to a prepreg containing the above resin composition or a semi-cured product of the resin composition. Another embodiment relates to a resin film containing the above resin composition or a semi-cured product of the resin composition. Another embodiment relates to a metal-clad laminate containing a cured product of the resin composition and a metal foil. Another embodiment relates to a printed wiring board containing a cured product of the resin composition. Another embodiment relates to a semiconductor package containing the above printed wiring board and a semiconductor element. Another embodiment relates to a semiconductor package containing a semiconductor element and a cured product of the resin composition that encapsulates the semiconductor element. Another embodiment relates to a printed wiring board containing at least one of a surface protective film and an interlayer insulating film formed from the resin composition.

[0008] The present disclosure provides a compound that can be used to produce a cured product in which deterioration of dielectric properties due to moisture absorption is suppressed, as well as a resin composition, prepreg, resin film, metal-clad laminate, printed wiring board, and semiconductor package that use the compound.

[0009] Figure 1 is the NMR spectrum of compound 1. Figure 2 is the NMR spectrum of compound 2. Figure 3 is the NMR spectrum of compound 3. Figure 4 is the NMR spectrum of compound 4. Figure 5 is the NMR spectrum of compound 5. Figure 6 is the NMR spectrum of compound 6.

[0010] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0011] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in the present disclosure, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, the upper or lower limit of a numerical range described in the present disclosure may be replaced with a value shown in the examples. In the present disclosure, unless otherwise specified, each component may contain one or more corresponding substances. In the present disclosure, when a resin composition contains multiple substances corresponding to each component, the content of each component in the resin composition means the total amount of the multiple substances present in the resin composition, unless otherwise specified.

[0012] In this disclosure, unless otherwise specified, the weight average molecular weight (Mw) and number average molecular weight (Mn) are values ​​measured by the following procedure. The weight average molecular weight and number average molecular weight are calculated by gel permeation chromatography (GPC) from a calibration curve using standard polystyrene. The calibration curve is approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Types: A-2500, A-5000, F-20, F-80) (manufactured by Tosoh Corporation, trade name). The GPC conditions are shown below.

[0013] Apparatus: High-speed GPC apparatus "HLC-8320GPC" (Tosoh Corporation, trade name) Detector: Ultraviolet absorption detector "UV-8320" (Tosoh Corporation, trade name) Columns: Guard column; TSKgel guard column Super (HZ)-M+, column; TSKgel SuperMultipore HZ-M (2 columns), reference column; TSKgel Super H-RC (2 columns) (all Tosoh Corporation, trade names) Column size: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 1 mL Injection volume: 20 μL or 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40°C

[0014] [Compound] A compound according to one embodiment of the present disclosure includes an indene ring, a vinylbenzyl group, and an aromatic ring-containing group having 6 or more carbon atoms and no polymerizable carbon-carbon double bond (hereinafter, also referred to as "aromatic ring-containing group X"). The vinylbenzyl group and the aromatic ring-containing group X are each directly bonded to the indene ring. Hereinafter, this compound may also be referred to as "compound A."

[0015] The vinylbenzyl group has relatively low polarity and can contribute to excellent dielectric properties. Meanwhile, the inventors' investigations revealed that moisture absorption can deteriorate the dielectric properties of cured products obtained using compounds having an indene ring and a vinylbenzyl group. The inventors then discovered that introducing an aromatic ring-containing group having 6 or more carbon atoms and no polymerizable carbon-carbon double bond into a compound, along with an indene ring and a vinylbenzyl group, can suppress deterioration of the dielectric properties of the resulting cured product due to moisture absorption. Without being bound by any particular theory, this is thought to be due to the bulky structure of the aromatic ring-containing group X, which is an aromatic ring-containing group having 6 or more carbon atoms, making it difficult for water molecules to approach. Furthermore, materials used in electronic devices are generally required to have a low thermal expansion coefficient, and Compound A can exhibit a good thermal expansion coefficient. Without being bound by any particular theory, it is speculated that control of molecular motion through interactions between aromatic rings, such as π-π interactions, can contribute to low thermal expansion.

[0016] Compound A may have an indene ring, one or more vinylbenzyl groups bonded to the indene ring, and one or more aromatic ring-containing groups X. Compound A has one or more vinylbenzyl groups in one molecule, and a cured product can be obtained by accelerating the reaction of the vinylbenzyl groups using heating or the like. Compound A may have two or more vinylbenzyl groups. Compound A may have two or more aromatic ring-containing groups X. Compound A may have one to two vinylbenzyl groups and one to two aromatic ring-containing groups X. Compound A may have two or three vinylbenzyl groups and aromatic ring-containing groups X in total. Compound A may be, for example, a hydrocarbon compound.

[0017] In Compound A, the vinylbenzyl group may further have a substituent. For example, the vinylbenzyl group is represented by the following formula (2).

[0018]

[0019] In formula (2), four R ５ R each independently represents a hydrogen atom or a monovalent substituent. ５ The monovalent substituent represented by R may be, for example, a halogen atom or a monovalent organic group. ５ The monovalent organic group represented by the formula (I) may be, for example, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, or an aryl group having 6 to 20 carbon atoms. The halogen atom may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. ５ may all be different from each other, or two or more of them may be the same. For example, ５ may all be hydrogen atoms. In formula (2), * represents a bonding site to the indene ring.

[0020] R ５The alkyl group having 1 to 5 carbon atoms represented by the formula (I) may be a linear or branched alkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a sec-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. ５ The alkoxy group having 1 to 5 carbon atoms represented by the formula (I) is, for example, a group represented by R—O—, where R may be the alkyl group having 1 to 5 carbon atoms described above. ５ The thioalkoxy group having 1 to 5 carbon atoms represented by the formula (I) is, for example, a group represented by R-S-, where R may be the alkyl group having 1 to 5 carbon atoms described above. ５ The aryl group having 6 to 20 carbon atoms represented by the formula (I) may be an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon, and examples thereof include a phenyl group, a biphenylyl group, a terphenylyl group, a naphthaleneyl group, an anthraceneyl group, a tetraceneyl group, a fluoreneyl group, a phenanthreneyl group, and derivatives thereof (excluding a vinylbenzyl group and derivatives thereof).

[0021] R ５ The monovalent organic group represented by R may be a non-aromatic organic group and may have 1 to 5, 1 to 4, 1 to 3, or 1 to 2 carbon atoms. ５ may be a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a thioalkoxy group having 1 to 5 carbon atoms, or may be a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms. ５ may be a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms, may be a hydrogen atom, or an alkyl group having 1 to 5, 1 to 4, 1 to 3, or 1 to 2 carbon atoms, or may be a hydrogen atom, a methyl group, or an ethyl group.

[0022] In Compound A, the vinylbenzyl group may be any of an o-vinylbenzyl group, an m-vinylbenzyl group, and a p-vinylbenzyl group. When two or more vinylbenzyl groups are contained in one molecule of Compound A, the structural isomers of the two or more vinylbenzyl groups may be the same or different. From the viewpoint of dielectric properties, it is preferable that at least one p-vinylbenzyl group is contained in one molecule of the vinylbenzyl compound.

[0023] In one molecule of compound A, the content of p-vinylbenzyl groups may be 10 to 100 mass %, 20 to 80 mass %, 30 to 70 mass %, or 40 to 60 mass % relative to the total mass of all vinylbenzyl groups.

[0024] The vinylbenzyl group may be, for example, a monovalent group that can be directly bonded to the 1-, 2-, or 3-position carbon atom of the indene ring. For example, one vinylbenzyl group may be bonded to only one of the 1-, 2-, or 3-position carbon atoms of the indene ring. For example, two vinylbenzyl groups may be directly bonded to the 1-position carbon atom of the indene ring. For example, one vinylbenzyl group may be directly bonded to each of two of the 1-, 2-, or 3-position carbon atoms of the indene ring. In either case, an aromatic ring-containing group X can be further bonded to at least one of the substitutable positions among the 1-, 2-, and 3-position carbon atoms of the indene ring. The 1- to 7-positions of the indene ring are as shown below.

[0025]

[0026] The aromatic ring-containing group (aromatic ring-containing group X) having 6 or more carbon atoms and no polymerizable carbon-carbon double bond may be a monovalent group. The aromatic ring in the aromatic ring-containing group X may be either a carbocyclic ring or a heterocyclic ring, but may be a carbocyclic ring from the viewpoint of dielectric properties. From the viewpoint of dielectric properties, the aromatic ring-containing group X is preferably a monovalent hydrocarbon group containing a carbocyclic ring. The aromatic ring-containing group X may contain a monocyclic ring, a fused ring, or a polycyclic ring in which two or more rings selected from monocyclic rings and fused rings are bonded via single bonds. From the viewpoint of curability, the number of rings is preferably 3 or less, and may be 2 or less, or 1. When the number of rings in the aromatic ring-containing group X is 3 or less, the reactivity of the vinylbenzyl group tends to be more effectively exhibited. For example, the number of carbon rings in the aromatic ring-containing group X is preferably 3 or less, and may be 2 or less, or 1. For example, the aromatic ring-containing group X may be a group containing a benzene ring, a biphenyl structure, a terphenyl structure, a naphthalene ring, a fluorene ring, a phenanthrene ring, or the like.

[0027] From the viewpoint of curability, the number of carbon atoms in the aromatic ring-containing group X may be 20 or less, 15 or less, 12 or less, or 10 or less. From the viewpoint of curability, the number of carbon atoms in the aromatic ring-containing group X may be 6 or more, 7 or more, or 8 or more. The number of carbon atoms in the aromatic ring-containing group X may be, for example, 6 to 20, 7 to 15, 8 to 12, or 8 to 10.

[0028] The aromatic ring-containing group X may be, for example, an aryl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond, or an arylalkyl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond, etc. From the viewpoint of being relatively similar to a vinylbenzyl group in which a vinyl group is bonded to a benzyl group and therefore facilitating the synthesis of compound A, an arylalkyl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond is preferred.

[0029] An aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. Examples of the aryl group in the aromatic ring-containing group X include a phenyl group, a biphenylyl group, a terphenylyl group, a naphthaleneyl group, an anthraceneyl group, a tetraceneyl group, a fluoreneyl group, and a phenanthreneyl group.

[0030] An arylalkyl group is a group in which at least one hydrogen atom of an alkyl group is substituted with an aryl group. In the arylalkyl group in the aromatic ring-containing group X, examples of the alkyl group include alkyl groups having 1 to 5 carbon atoms, more specifically, methyl, ethyl, n-propyl, n-butyl, n-pentyl, isopropyl, isobutyl, sec-butyl, and tert-butyl groups. In the arylalkyl group in the aromatic ring-containing group X, examples of the aryl group include the aryl groups described above. The number of carbon atoms in an unsubstituted monovalent arylalkyl group may be, for example, 7 to 20, 7 to 15, 8 to 12, or 8 to 10. Examples of the arylalkyl group include a benzyl group, a phenethyl group, a naphthylmethyl group, and a naphthylethyl group. A benzyl group is preferred because of its relative similarity to a vinylbenzyl group and the resulting easier synthesis of compound A.

[0031] In the aromatic ring-containing group X, when the aryl group or arylalkyl group has a substituent, the substituent preferably does not have a carbon-carbon double bond. Examples of such a substituent include a halogen atom and a monovalent organic group that does not have a carbon-carbon double bond. The halogen atom may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. The monovalent organic group that does not have a carbon-carbon double bond may be, for example, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, or an aryl group having 6 to 20 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

[0032] The aromatic ring-containing group X may be a group containing a heteroatom or a group not containing a heteroatom. The aromatic ring-containing group X may be, for example, a monovalent group not containing a heteroatom. Examples of the aromatic ring-containing group X include a methylbenzyl group, an ethylbenzyl group, a butylbenzyl group, a dimethylbenzyl group, and a trimethylbenzyl group.

[0033] In the compound A, the aromatic ring-containing group X may be, for example, a monovalent organic group represented by the following formula (3).

[0034]

[0035] In formula (3), five R ６ are each independently a hydrogen atom or a substituent. The substituent may be, for example, a halogen atom or a monovalent organic group. ６ The halogen atom and the monovalent organic group represented by the formula (2) are R ５ The five R ６ may all be different from each other, or two or more of them may be the same. For example, ６ In another example, all five R ６ four of the R ６ four of R may be hydrogen atoms and one may be a methyl group or an ethyl group, or five R ６ Of these, four may be hydrogen atoms and one may be a methyl group. For example, five R ６ When four of the groups are hydrogen atoms and one is an alkyl group, the alkyl group may be bonded to any of the o-, m-, and p-positions, but is preferably bonded to the p-position.

[0036] The aromatic ring-containing group X may be, for example, an o-methylbenzyl group, an m-methylbenzyl group, or a p-methylbenzyl group. The aromatic ring-containing group X may be, for example, a p-methylbenzyl group.

[0037] When compound A contains two or more aromatic ring-containing groups X, the two or more aromatic ring-containing groups X may be the same or different.

[0038] The aromatic ring-containing group X may be, for example, a monovalent group that can be directly bonded to the 1-, 2-, or 3-position carbon atom on the indene ring. For example, one aromatic ring-containing group X may be bonded to only one of the 1-, 2-, or 3-position carbon atoms on the indene ring. For example, two aromatic ring-containing groups X may be directly bonded to the 1-position carbon atom on the indene ring. For example, one aromatic ring-containing group X may be directly bonded to each of two of the 1-, 2-, or 3-position carbon atoms on the indene ring. In either case, a vinylbenzyl group may further be bonded to at least one of the substitutable positions among the 1-, 2-, or 3-position carbon atoms on the indene ring.

[0039] Compound A may further have a monovalent substituent other than a vinylbenzyl group and an aromatic ring-containing group X on a carbon atom of the indene ring. Compound A may have a monovalent substituent other than a vinylbenzyl group and an aromatic ring-containing group X on, for example, one or more of the carbon atoms at the 4-, 5-, 6- and 7-positions of the indene ring.

[0040] Examples of monovalent substituents other than the vinylbenzyl group and the aromatic ring-containing group X include halogen atoms and monovalent organic groups. The halogen atom may be a fluorine atom, chlorine atom, bromine atom, or iodine atom. Examples of monovalent organic groups include alkyl groups having 1 to 5 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, thioalkoxy groups having 1 to 5 carbon atoms, and aryl groups having 6 to 20 carbon atoms. Examples of alkyl groups having 1 to 5 carbon atoms include methyl groups, ethyl groups, n-propyl groups, n-butyl groups, n-pentyl groups, isopropyl groups, isobutyl groups, sec-butyl groups, and tert-butyl groups.

[0041] Compound A may be, for example, a compound that does not have a monovalent substituent on the carbon atoms at positions 4, 5, 6, and 7 of the indene ring. Compound A may be, for example, a compound that does not have a monovalent substituent other than a vinylbenzyl group or an aromatic ring-containing group X on the carbon atoms of the indene ring.

[0042] Compound A may have a structure in which, for example, one vinylbenzyl group is directly bonded to the carbon atom at the 1st, 2nd or 3rd position of an indene ring, one aromatic ring-containing group X is directly bonded to the carbon atom at the 1st, 2nd or 3rd position of an indene ring, and the other carbon atoms constituting the indene ring are unsubstituted. Materials used for metal-clad laminates, prepregs, etc. used in electronic devices are preferably those that can improve adhesive strength with metal foil, and such a structure makes it easier to obtain better adhesive strength with metal foil.

[0043] An oligomer or prepolymer with a low degree of polymerization can be provided by polymerizing a compound having a vinylbenzyl group and an aromatic ring-containing group X introduced into an indene ring using compound A. Both the oligomer and the prepolymer preferably contain a certain amount of unreacted vinylbenzyl groups and are in a state in which a curing reaction can be initiated by heating or the like.

[0044] Examples of compound A include compounds represented by the following formula (1).

[0045]

[0046] In formula (1), R １ ~R ４ R each independently represents a hydrogen atom or a monovalent substituent. １ , R ２ and R ３ At least one of R is a vinylbenzyl group; １ , R ２ and R ３ At least one of the four R is an aromatic ring-containing group X. ４ may all be different from each other, and four R ４ Two or more of the vinylbenzyl group and the aromatic ring-containing group X may be the same as each other.

[0047] R １ , R ２ and R ３The monovalent substituent represented by the formula (I) may be a halogen atom, a monovalent organic group, or the like. The halogen atom may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. The monovalent organic group may be, for example, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, an aryl group having 6 to 20 carbon atoms, a vinylbenzyl group, or an aromatic ring-containing group X. The alkyl group having 1 to 5 carbon atoms may be, for example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an isopropyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group.

[0048] R ４ The monovalent substituent represented by may be, for example, a halogen atom or a monovalent organic group. The halogen atom may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. The monovalent organic group may be, for example, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, or an aryl group having 6 to 20 carbon atoms. Examples of alkyl groups having 1 to 5 carbon atoms include R １ , R ２ , R ３ The above-mentioned examples are included.

[0049] In formula (1), R １ , R ２ and R ３ In addition, one or two of R １ , R ２ and R ３ One or two of the remaining groups may be an aromatic ring-containing group X. １ , R ２ and R ３ one or two of R １ , R ２ and R ３ One or two of the remaining groups among the four R groups may be aromatic ring-containing groups X, and the total number of vinylbenzyl groups and aromatic ring-containing groups X may be two or three. ４ may all be hydrogen atoms.

[0050] From the viewpoint of adhesive strength with the metal foil, for example, R １ , R ２ and R ３ any one of R is a vinylbenzyl group; １ , R ２ and R ３ is an aromatic ring-containing group X, and R １ , R ２ and R ３ Any other one of may be a hydrogen atom.

[0051] The following describes a method for synthesizing Compound A. Compound A is a compound that is specified by its molecular structure, regardless of the synthesis method described below.

[0052] Examples of methods for synthesizing compound A include a method of reacting a base compound having an indene ring, a styrene having a halogenated methyl group, and a compound containing an aromatic ring substituted with a halogen or halogenated alkyl group in the presence of a basic compound. Examples of styrenes having a halogenated methyl group include o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene, and these may be used alone or in combination. Examples of compounds containing an aromatic ring substituted with a halogen or halogenated alkyl group include compounds containing an aromatic ring with a chloroalkyl group, such as α-chloro-p-xylene, and these may be used alone or in combination. Examples of basic compounds include alkali metal hydroxides and alkali metal alkoxides.

[0053] A phase transfer catalyst may be used in the above reaction. Examples of the phase transfer catalyst include quaternary ammonium salts such as tetra-n-butylammonium chloride, tetra-n-butylammonium bromide (tetra-n-butylammonium bromide), tetraethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium chloride, tetrapropylammonium bromide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltributylammonium chloride, benzyltributylammonium bromide, benzyldimethyltetradecylammonium chloride, tricaprylmethylammonium chloride, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, trioctylmethylammonium chloride, and tetra-n-butylammonium hydrogen sulfate; and quaternary phosphonium salts such as tetra-n-butylphosphonium chloride, tetra-n-butylphosphonium bromide, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, benzyltriphenylphosphonium chloride, and benzyltriphenylphosphonium bromide. The reaction can be carried out by solution polymerization. The reaction can be carried out, for example, under heating and stirring. A polymerization inhibitor can be added to the reaction system.Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, tert-butylhydroquinone, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, hydroquinone monomethyl ether, 1,4-benzoquinone, 2-tert-butyl-1,4-benzoquinone, 2-tert-butylphenol, 2,4-di-tert-butylphenol, 2,6-di-tert-butylphenol, cresol, catechol, and 4-tert-butylcatechol. Examples of suitable solvents include chol, pyrogallol, 4-methoxyphenol, thiodiphenylamine, phenothiazine, 3,7-dioctylphenothiazine, 3,7-dicumylphenothiazine, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, bis(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl)sebacate, etc. The resulting product may be purified, if necessary, by known methods such as concentration, reprecipitation, washing, etc.

[0054] The resulting compound may be a single compound or a mixture of two or more compounds. For example, a compound is synthesized in which a vinylbenzyl group is directly bonded to at least one carbon atom at the 1st, 2nd, and 3rd positions of the indene ring and an aromatic ring-containing group is directly bonded to at least one carbon atom at the 1st, 2nd, and 3rd positions of the indene ring, and two or more isomeric compounds with different bonding sites may be included in the mixture. Furthermore, depending on the synthesis conditions, etc., the mixture may contain two or more compounds with different numbers and bonding sites of the vinylbenzyl group and the aromatic ring-containing group X to the indene ring. Furthermore, for example, in addition to compound A, the mixture may contain a compound in which only one of a vinylbenzyl group or an aromatic ring-containing group X is bonded to the indene ring.

[0055] When a mixture of two or more compounds is obtained by synthesizing compound A, the weight-average molecular weight (Mw) of this mixture is not particularly limited, but from the viewpoints of moldability and handleability, it is preferably 240 to 350, more preferably 250 to 340, and even more preferably 260 to 330. In addition, the number-average molecular weight (Mn) of this mixture is preferably 200 to 330, more preferably 210 to 320, and even more preferably 210 to 310.

[0056] The dielectric constant (Dk) of the cured product of compound A at 25°C and 10 GHz may be, for example, 4.0 or less, 3.5 or less, or 3.4 or less. On the other hand, the dielectric constant (Dk) of the cured product of compound A at 25°C and 10 GHz may be, for example, 2.3 or more, or 2.4 or more. The dielectric constant (Dk) of the cured product of compound A at 25°C and 10 GHz may be, for example, 2.3 to 4.0, 2.3 to 3.5, or 2.4 to 3.4. The dielectric dissipation factor (Df) of the cured product of compound A at 25°C and 10 GHz may be, for example, 0.0020 or less, 0.0015 or less, 0.0013 or less, 0.0010 or less, or 0.0008 or less. On the other hand, the dielectric dissipation factor (Df) of the cured product of compound A at 25°C and 10 GHz may be, for example, 0.0001 or more, or 0.0002 or more. The dielectric dissipation factor (Df) of the cured product of compound A at 25°C and 10 GHz may be, for example, 0.0001 to 0.0020, 0.0001 to 0.0015, 0.0001 to 0.0013, 0.0002 to 0.0010, or 0.0002 to 0.0008. The thermal expansion coefficient of the cured product of compound A at 30 to 120°C may be, for example, 30 to 50 ppm / °C. When a mixture of two or more compounds is obtained by synthesizing compound A, the dielectric constant (Dk) at 25°C and 10 GHz, the dielectric dissipation factor (Df) at 25°C and 10 GHz, and / or the thermal expansion coefficient from 30 to 120°C of the cured product of this mixture may be, for example, within the above-mentioned ranges. The sample to be measured for the dielectric constant (Dk) at 25°C and 10 GHz, the dielectric dissipation factor (Df) at 25°C and 10 GHz, and the thermal expansion coefficient from 30 to 120°C of the cured product of compound A is obtained by curing compound A and bringing it into a C-stage state according to JIS K 6800 (1985). Specifically, for example, a sample can be prepared by the method described in the Examples. The dielectric constant (Dk) at 25°C and 10 GHz and the dielectric dissipation factor (Df) at 25°C and 10 GHz of the cured product of the resin composition may be measured in accordance with the method described below for measuring the dielectric constant (Dk) and dielectric dissipation factor (Df) at 25°C and 10 GHz of the cured product. The thermal expansion coefficient of the cured product of Compound A at 30 to 120°C may be measured in accordance with the thermal expansion coefficient of the cured product of the resin composition at 30 to 120°C, which will be described later.

[0057] Compound A can be used in a wide range of fields, including mobile communication devices such as smartphones, base station devices thereof, network infrastructure devices such as servers, routers, and large servers, various electronic devices such as large computers, personal computers, and industrial computers, and electronic devices installed in home appliances and automobiles.

[0058] [Resin Composition] A resin composition of one embodiment contains the above-described compound A. <Compound A> The resin composition may contain the above-described compound A either alone or in combination of two or more.

[0059] From the viewpoint of dielectric properties and heat resistance, the content of compound A may be 10% by mass or more, 20% by mass or more, or 30% by mass or more, relative to the solid content of the resin composition. On the other hand, from the viewpoint of dielectric properties and heat resistance, the content of compound A may be 100% by mass or less, 90% by mass or less, or 80% by mass or less, relative to the solid content of the resin composition. Compound A may be, for example, 10 to 100% by mass, 20 to 90% by mass, or 30 to 80% by mass, relative to the solid content of the resin composition.

[0060] In the present disclosure, the "solid content" of a resin composition refers to components in the resin composition other than volatile substances such as water, the solvent described below, etc. The solid content is a component that remains without volatilizing when the resin composition is dried, and includes components that are liquid, syrup-like, or waxy at room temperature around 25°C, and does not necessarily mean that they are solid.

[0061] <Other Components> The resin composition may contain other components other than the compound A, as necessary. Examples of the other components include thermosetting resins, fillers, elastomers, curing agents, curing accelerators, solvents, flame retardants, antioxidants, heat stabilizers, antistatic agents, UV absorbers, pigments, colorants, lubricants, etc. Each of the other components may be used alone, or two or more may be used in combination.

[0062] The resin composition may further contain a thermosetting resin in addition to the compound A. A compound having a reactive group can be used as the thermosetting resin. For example, the thermosetting resin may be a compound having a reactive group that is self-curable or curable in combination with a curing agent.

[0063] The thermosetting resin is not particularly limited, and examples thereof include epoxy resins, maleimide compounds, phenolic resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, and melamine resins.

[0064] Among these, epoxy resins, phenolic resins, and maleimide compounds are preferred from the viewpoint of thermosetting properties and dielectric properties.

[0065] The epoxy resin preferably has two or more epoxy groups per molecule. Examples of the epoxy resin include glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, and glycidyl ester type epoxy resins. Each of these types of epoxy resins can be further classified into bisphenol type epoxy resins, alicyclic epoxy resins, aliphatic linear epoxy resins, novolac type epoxy resins, stilbene type epoxy resins, naphthalene skeleton-containing epoxy resins, biphenyl type epoxy resins, xylylene type epoxy resins, and dihydroanthracene type epoxy resins.

[0066] Examples of the maleimide compound include compounds having one or more N-substituted maleimide groups and derivatives thereof. For example, at least one compound selected from the group consisting of compounds having two or more N-substituted maleimide groups and derivatives thereof may be used.

[0067] Examples of the compound having one or more N-substituted maleimide groups include aromatic maleimide compounds which are compounds having an N-substituted maleimide group directly bonded to an aromatic ring, aromatic bismaleimide compounds which are compounds having two N-substituted maleimide groups directly bonded to an aromatic ring, aromatic polymaleimide compounds which are compounds having three or more N-substituted maleimide groups directly bonded to an aromatic ring, and aliphatic maleimide compounds which are compounds having an N-substituted maleimide group directly bonded to an aliphatic hydrocarbon.

[0068] Specific examples of the compound having one or more N-substituted maleimide groups include N,N'-ethylene bismaleimide, N,N'-hexamethylene bismaleimide, N,N'-(1,3-phenylene)bismaleimide, N,N'-[1,3-(2-methylphenylene)]bismaleimide, N,N'-[1,3-(4-methylphenylene)]bismaleimide, N,N'-(1,4-phenylene)bismaleimide, bis(4-maleimidophenyl)methane, bis(3-methyl-4-maleimidophenyl)methane, 3,3'-dimethyl-5, 5'-Diethyl-4,4'-diphenylmethane bismaleimide, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfone, bis(4-maleimidophenyl)sulfide, bis(4-maleimidophenyl)ketone, bis(4-maleimidocyclohexyl)methane, 1,4-bis(4-maleimidophenyl)cyclohexane, 1,4-bis(maleimidomethyl)cyclohexane, 1,4-bis(maleimidomethyl)benzene, 1,3-bis(4-maleimidophenoxy)benzene, 1,3-bis (3-maleimidophenoxy)benzene, bis[4-(3-maleimidophenoxy)phenyl]methane, bis[4-(4-maleimidophenoxy)phenyl]methane, 1,1-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,1-bis[4-(4-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(4-maleimidophenoxy)phenyl]ethane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]propanol Pan, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4-bis(3-maleimidophenoxy)biphenyl, 4,4-bis(4-maleimidophenoxy)biphenyl, bis[4-(3-maleimidophenoxy)phenyl]ketone, bis[4-(4-maleimidophenoxy)phenyl]ketone, bis(4-maleimidophenyl)disulfide, bis[4-(3-maleimidophenoxy)phenyl]sulfide, bis[4-(4-maleimidophenoxy)phenyl]sulfide, bis[4-(3-maleimidophenoxy)phenyl]sulfoxide, bis Bis[4-(4-maleimidophenoxy)phenyl]sulfoxide, bis[4-(3-maleimidophenoxy)phenyl]sulfone, bis[4-(4-maleimidophenoxy)phenyl]sulfone, bis[4-(3-maleimidophenoxy)phenyl]ether, bis[4-(4-maleimidophenoxy)phenyl]ether, 1,4-bis[4-(4-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[ 4-(4-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-maleimidophenoxy)- 3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, polyphenylmethane maleimide, aromatic bismaleimide compounds having an indane skeleton, biphenylaralkyl maleimide compounds, etc.

[0069] Examples of derivatives of compounds having one or more N-substituted maleimide groups include aminomaleimide compounds containing structural units derived from the above-described compounds having one or more N-substituted maleimide groups and structural units derived from diamine compounds.

[0070] In the resin composition, the compound A may be 10% by mass or more, 20% by mass or more, or 30% by mass or more, based on the total amount of the thermosetting resin. On the other hand, the compound A may be 100% by mass or less, 90% by mass or less, or 80% by mass or less, based on the total amount of the thermosetting resin. The compound A may be, for example, 10 to 100% by mass, 20 to 90% by mass, or 30 to 80% by mass, based on the solid content of the resin composition.

[0071] In the resin composition, the amount of the thermosetting resin containing compound A may be, for example, 50 mass % or more, 60 mass % or more, 70 mass % or more, or 100 mass % relative to the total amount of the resin composition.

[0072] The filler is preferably an inorganic filler, for example, silica (SiO ２ ), alumina (Al ２ O ３ ), titanium oxide, barium titanate, strontium titanate, potassium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, aluminum borate, silicon carbide, mica, beryllia, clay, talc, etc. Silica is preferred from the viewpoint of dielectric properties.

[0073] The shape and size of the filler are not particularly limited. The average particle size of the filler may be, for example, 0.01 to 20 μm, or 0.1 to 10 μm. Here, the average particle size of the filler is the particle size at a point corresponding to an integrated value of 50% in a volume-based particle distribution measured by a laser diffraction scattering method.

[0074] Examples of the elastomer include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers.

[0075] As the curing accelerator, for example, a radical polymerization initiator can be used. The radical polymerization initiator may be a thermal radical polymerization initiator or a photoradical polymerization initiator, but a thermal radical polymerization initiator is preferred. The radical polymerization initiator is not particularly limited, and examples thereof include an azo-based polymerization initiator and an organic peroxide-based polymerization initiator. Examples of the azo polymerization initiator include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylpropanenitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylpropionate)dimethyl, 1,1'-azobis(methyl cyclohexylcarboxylate), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), 4,4'-azobis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl 4-cyanopentanoate), and 1,1'-azobis(cyclohexane-1-carbonitrile). Examples of organic peroxide polymerization initiators include dicumyl peroxide, dibenzoyl peroxide, 2-butanone peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, bis(tert-butylperoxyisopropyl)benzene, and tert-butyl hydroperoxide.

[0076] The resin composition may be a solvent-free resin composition or may contain a solvent. The solvent can adjust the viscosity of the resin composition and further improve the coatability. The solvent is preferably an organic solvent.

[0077] Examples of the organic solvent include alcohol-based solvents such as ethanol, propanol, butanol, methyl cellosolve, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based solvents such as tetrahydrofuran; aromatic hydrocarbon-based solvents such as toluene, xylene, and mesitylene; nitrogen-containing solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfur-containing solvents such as dimethyl sulfoxide; and ester-based solvents such as γ-butyrolactone.

[0078] When the resin composition contains a solvent, the solid content of the resin composition may be, for example, 30 to 95 mass%, 40 to 90 mass%, 50 to 80 mass%, or 50 to 70 mass%, relative to the total mass of the resin composition.

[0079] <Method for producing resin composition> The method for producing the resin composition is not particularly limited. The resin composition according to one embodiment is not limited by the production method, and its characteristics are as described in the present disclosure. In one example of the method for producing the resin composition, compound A and, if necessary, any optional components are added and mixed to obtain the resin composition. More specifically, for example, compound A is dissolved or dispersed in a solvent, and if necessary, other components are added and mixed to obtain the resin composition. The conditions such as the mixing order, temperature, and time of each component are not particularly limited, and may be appropriately adjusted depending on the type of raw material, production scale, production equipment, etc.

[0080] <Dielectric Properties of Cured Resin Composition> The dielectric constant (Dk) of the cured resin composition at 25°C and 10 GHz is preferably 4.0 or less, more preferably 3.5 or less, and even more preferably 3.4 or less. The smaller the dielectric constant (Dk) of the cured resin composition at 25°C and 10 GHz, the better. There is no particular restriction on the lower limit, but taking into consideration the balance with other physical properties, it may be, for example, 2.3 or more, or 2.4 or more. For example, the dielectric constant (Dk) of the cured resin composition at 25°C and 10 GHz may be 2.3 to 4.0, 2.3 to 3.5, or 2.4 to 3.4.

[0081] The dielectric loss tangent (Df) of the cured product of the resin composition at 25°C and 10 GHz is preferably 0.0020 or less, more preferably 0.0015 or less, even more preferably 0.0013 or less, even more preferably 0.0010 or less, and even more preferably 0.0008 or less. The smaller the dielectric loss tangent (Df) of the cured product of the resin composition at 25°C and 10 GHz, the better, and there is no particular restriction on the lower limit, but it may be, for example, 0.0001 or more, or 0.0002 or more, taking into consideration the balance with other physical properties.

[0082] For example, the dielectric loss tangent (Df) at 25°C and 10 GHz of the cured product of the resin composition may be 0.0001 to 0.0020, 0.0001 to 0.0015, 0.0001 to 0.0013, 0.0002 to 0.0010, or 0.0002 to 0.0008.

[0083] In the present disclosure, the dielectric constant (Dk) and dielectric loss tangent (Df) at 25°C and 10 GHz are measured in the 10 GHz band at 25°C in accordance with the SPDR method (split post dielectric resonator). Measurement devices that can be used include an Agilent Technologies vector network analyzer E8364B and a Vega Technologies 10 GHz SPDR. The sample to be measured for the dielectric constant (Dk) and dielectric loss tangent (Df) of the cured resin composition is a resin composition cured to a C-stage state according to JIS K 6800 (1985). Specifically, for example, a sample can be prepared by the method described in the examples.

[0084] <Thermal expansion coefficient of cured resin composition> The thermal expansion coefficient of the cured resin composition at 30 to 120°C may be, for example, 30 to 50 ppm / °C. In the present disclosure, the thermal expansion coefficient at 30 to 120°C is measured in accordance with the IPC (The Institute for Interconnecting and Packaging Electronic Circuits) standard. As a measuring device, a thermomechanical measuring device (TMA) (manufactured by TA Instruments Japan Co., Ltd., product name: Q400) can be used. The sample to be measured is a resin composition cured to a C-stage state according to JIS K 6800 (1985). Specifically, for example, a sample can be prepared by the method described in the examples.

[0085] [Prepreg] According to one embodiment, a prepreg containing a resin composition or a semi-cured product of the resin composition can be provided. This prepreg can be formed, for example, using the resin composition and a fiber substrate. The resin composition can be any of the resin compositions described above. Details of the resin composition are as described above.

[0086] The prepreg may contain the resin composition described above or a semi-cured product of the resin composition described above. In the present disclosure, one indicator of a semi-cured product is the B-stage state according to JIS K 6800 (1985). The prepreg may contain, for example, a resin composition or a semi-cured product of the resin composition and a fibrous substrate such as a sheet-like fibrous substrate. In the prepreg, the resin composition may be in an uncured state, or the resin composition may be in a partially or entirely semi-cured state.

[0087] Prepregs can be obtained, for example, by coating a fiber substrate with a resin composition and drying it. For example, prepregs can be obtained by impregnating a fiber substrate with a resin composition and then drying the fiber substrate impregnated with the resin composition. Drying is preferably carried out at a temperature at or above which volatile components such as solvents that may be contained in the resin composition are removed, and may be carried out at a temperature at or above which the thermosetting resin contained in the resin composition is semi-cured depending on the application. Furthermore, drying is preferably adjusted so that the thermosetting resin contained in the resin composition is not completely cured. From this perspective, the drying temperature may be, for example, 80 to 200°C, and the drying time may be, for example, 1 to 30 minutes depending on the drying temperature, drying equipment, its scale, etc.

[0088] The fiber substrate may be any of woven fabric, knitted fabric, and nonwoven fabric. The fiber substrate may be provided in the form of chopped strand mat, roving, etc. The fiber material may be any of inorganic fiber and organic fiber. Examples of inorganic fiber include glass fiber and carbon fiber. Examples of glass fiber include E-glass, NE-glass, D-glass, S-glass, Q-glass, etc. Examples of organic fiber include polyimide, polyester, tetrafluoroethylene, etc. The fiber substrate may be made of one type of these fibers alone or a combination of two or more types of these fibers. From the viewpoints of dielectric properties and heat resistance, the material of the fiber substrate is preferably inorganic fiber, and more preferably glass fiber.

[0089] The fiber substrate may be selected appropriately depending on the application of the prepreg, but a sheet-like fiber substrate is preferred. Examples of the sheet-like fiber substrate include various sheet-like fiber substrates used in known laminates for electrical insulating materials. The thickness of the sheet-like fiber substrate is not particularly limited, but is preferably 0.02 to 0.5 mm, for example. Here, the thickness is measured at five points at equal distances across the entire surface of the sheet-like fiber substrate, and the arithmetic average value of the five measurements is used.

[0090] [Resin Film] According to one embodiment, a resin film containing a resin composition or a semi-cured product of the resin composition can be provided. Details of the resin composition are as described above.

[0091] The resin film may contain the resin composition described above or a semi-cured product of the resin composition described above. In the resin film, the resin composition may be in an uncured state, or the resin composition may be in a partially or entirely semi-cured state. For example, a cured product can be obtained by curing this resin film by heat treatment or the like. The resin film can be obtained, for example, by applying the resin composition to a substrate and drying it. Drying can be performed, for example, in the same manner as in the prepreg manufacturing method described above. After drying the resin film on the substrate, a product can be provided as a combination of the resin film and the substrate. For example, this method can provide a resin film to form an insulating layer or the like on the substrate in electronic devices, etc. In another method, after drying the resin film on the substrate, the resin film can be peeled off from the substrate to provide the resin film as a product.

[0092] The substrate may be either an inorganic substrate or an organic substrate, and examples thereof include glass substrates, metal substrates such as metal foils and metal plates, plastic substrates such as plastic plates and plastic films, and paper substrates, as well as the fiber substrates described above for the prepreg. A substrate having a release layer formed on its surface may be used so that the resin film can be peeled off from the substrate.

[0093] [Metal-clad laminate] According to one embodiment, a metal-clad laminate including a cured resin composition and a metal foil can be provided. This metal-clad laminate may be, for example, a metal-clad laminate including a cured prepreg and a metal foil. According to another embodiment, a metal-clad laminate formed using a prepreg and a metal foil can also be provided. This metal-clad laminate may be, for example, a metal-clad laminate including a cured prepreg and a metal foil. Details of the resin composition and the prepreg are as described above. In the present disclosure, the C-stage state in JIS K 6800 (1985) can be cited as one indicator of the cured product.

[0094] The metal-clad laminate preferably includes a cured resin layer containing a cured resin and a metal foil disposed on at least one surface of the cured resin layer. The cured resin layer includes a cured product of the resin composition described above, but may also be a cured product of the prepreg described above. For example, in the metal-clad laminate, a metal foil is disposed on at least one surface of the cured prepreg, more preferably on both surfaces of the cured prepreg. The metal-clad laminate may be manufactured by disposing a metal foil on at least one surface of a single sheet-like prepreg, or may be manufactured by laminating two or more sheet-like prepregs and disposing a metal foil on at least one surface of the outermost surface of the laminate. For example, the metal-clad laminate may be manufactured by laminating two or more sheet-like prepregs and disposing a metal foil on both surfaces of the laminate.

[0095] Hereinafter, as a specific example of a method for producing a metal-clad laminate, a method in which a metal foil is arranged on a laminate of two or more sheet-like prepregs will be described.

[0096] First, two or more sheet-like prepregs are laminated to obtain a laminate. In this laminate, the two or more sheet-like prepregs may be identical to each other, or some or all of them may be different. In the laminate, it is sufficient that at least one of the two or more sheet-like prepregs is obtained using the resin composition according to one embodiment.

[0097] Next, a metal foil is placed on at least one surface of this laminate. The laminate with the metal foil placed thereon is heated and pressurized. This progresses the curing reaction of the sheet-like prepreg, resulting in a cured prepreg. Furthermore, adjacent sheet-like prepregs can be fixed together. The heating and pressurizing conditions are not particularly limited, but may be, for example, a temperature of 100 to 300°C, a time of 10 to 300 minutes, and a pressure of 1.5 to 5 MPa. Furthermore, after heating and pressurizing, reheating may be performed to further promote the curing of the prepreg. In this case, the reheating temperature may be 100 to 300°C. Examples of pressurizing methods that can be used include an autoclave molding machine, a multi-stage press, a multi-stage vacuum press, and a continuous molding machine.

[0098] The metal for the metal foil is not particularly limited, and examples thereof include copper, nickel, aluminum, gold, silver, platinum, molybdenum, ruthenium, tungsten, iron, titanium, chromium, and alloys containing two or more of these metal elements. Industrially, the metals copper, nickel, and aluminum are preferred. By using copper as the metal foil, a copper-clad laminate can be provided.

[0099] The dielectric properties of an evaluation substrate obtained by removing the metal foil from a metal-clad laminate (hereinafter also referred to as a "metal foil-removed evaluation substrate") are preferably as follows.

[0100] The dielectric constant (Dk) of the metal foil removal evaluation substrate at 25°C and 10 GHz is preferably 4.0 or less, more preferably 3.5 or less, and even more preferably 3.4 or less. The smaller the dielectric constant (Dk) of the metal foil removal evaluation substrate at 25°C and 10 GHz, the better, and there is no particular restriction on the lower limit, but it may be, for example, 2.3 or more, or 2.4 or more, taking into consideration the balance with other physical properties. For example, the dielectric constant (Dk) of the metal foil removal evaluation substrate at 25°C and 10 GHz may be 2.3 to 4.0, and preferably 2.3 to 3.5, or 2.4 to 3.4.

[0101] The dielectric dissipation factor (Df) of the metal foil removal evaluation substrate at 25°C and 10 GHz is preferably 0.0020 or less, more preferably 0.0015 or less, and even more preferably 0.0013 or less. The smaller the dielectric dissipation factor (Df) of the metal foil removal evaluation substrate at 25°C and 10 GHz, the better. There is no particular restriction on the lower limit, but taking into consideration the balance with other physical properties, it may be, for example, 0.0001 or more, 0.0002 or more, or 0.0005 or more. For example, the dielectric dissipation factor (Df) of the metal foil removal evaluation substrate at 25°C and 10 GHz may be 0.0001 to 0.0020, 0.0002 to 0.0015, or 0.0005 to 0.0013.

[0102] The dielectric constant (Dk) and dielectric loss tangent (Df) of the metal foil removal evaluation substrate at 25°C and 10 GHz may be measured in accordance with the measurement of the dielectric constant (Dk) and dielectric loss tangent (Df) of the cured product of the resin composition at 25°C and 10 GHz described above.

[0103] The thermal expansion coefficient of the metal foil removal evaluation substrate from 30 to 120°C (also simply referred to as the thermal expansion coefficient of the metal-clad laminate from 30 to 120°C) may be, for example, 30 to 50 ppm / °C. The thermal expansion coefficient of the metal foil removal evaluation substrate from 30 to 120°C may be measured in accordance with the measurement of the thermal expansion coefficient from 30 to 120°C of the cured product of the resin composition described above.

[0104] [Printed Wiring Board] According to one embodiment, a printed wiring board including a cured product of the resin composition can be provided. Also, according to one embodiment, a printed wiring board including at least one of a surface protective film and an interlayer insulating film formed from the resin composition can be provided. Details of the resin composition are as described above.

[0105] In the printed wiring board, the cured product of the resin composition can be produced using a resin composition, a prepreg, a resin film, a metal-clad laminate, or a combination thereof. For example, a printed wiring board can be provided by forming wiring on a cured product of a prepreg by a known method. In another example, a printed wiring board can be provided by forming wiring using a metal-clad laminate by a known method. A printed wiring board combining these examples may also be used. Details of the prepreg, resin film, and metal-clad laminate are as described above.

[0106] The printed wiring board may be either a single-layer printed wiring board or a multi-layer printed wiring board.

[0107] [Semiconductor Package] According to one embodiment, a semiconductor package can be provided that includes a printed wiring board and a semiconductor element. More specifically, for example, a semiconductor package can be provided that includes a printed wiring board containing a cured product of a resin composition and a semiconductor element. Details of the resin composition are as described above. Details of the cured product of the resin composition and the printed wiring board are also as described above. The semiconductor package can be manufactured, for example, by mounting a semiconductor element, a memory, etc. on a printed wiring board by a known method. The cured product of the resin composition may be used as an insulating material, encapsulating material, etc. for the semiconductor package. For example, a semiconductor package can be provided that includes a semiconductor element and a cured product of the resin composition that encapsulates the semiconductor element.

[0108] Preferred examples of the present disclosure are listed below: The embodiments of the present invention are not limited to the following examples.

[0109] <1> A compound comprising an indene ring, a vinylbenzyl group, and an aromatic ring-containing group having 6 or more carbon atoms and no polymerizable carbon-carbon double bond, wherein the vinylbenzyl group and the aromatic ring-containing group are each directly bonded to the indene ring. <2> A compound represented by the following formula (1): (In formula (1), R １ ~R ４R each independently represents a hydrogen atom or a monovalent substituent. １ , R ２ and R ３ At least one of R is a vinylbenzyl group; １ , R ２ and R ３ At least one of the four R is an aromatic ring-containing group having 6 or more carbon atoms and not having a polymerizable carbon-carbon double bond. ４ may all be different from each other, and four R ４ Two or more of these may be the same.) <3> The compound according to <1> or <2>, wherein the aromatic ring-containing group is an aryl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond, or an arylalkyl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond. <4> The compound according to <3>, wherein the aromatic ring-containing group is a benzyl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond. <5> A resin composition comprising the compound according to any one of <1> to <4>. <6> A prepreg comprising the resin composition according to <5> or a semi-cured product of the resin composition. <7> A resin film comprising the resin composition according to <5> or a semi-cured product of the resin composition. <8> A metal-clad laminate comprising a cured product of the resin composition according to <5> and a metal foil. <9> A printed wiring board comprising a cured product of the resin composition according to <5>. <10> A semiconductor package comprising the printed wiring board according to <9> and a semiconductor element. <11> A semiconductor package comprising a semiconductor element and a cured product of the resin composition according to <5> that encapsulates the semiconductor element. <12> A printed wiring board comprising at least one of a surface protective film and an interlayer insulating film formed from the resin composition according to <5>.

[0110] The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2023-099182, filed on June 16, 2023, the entire disclosure of which is incorporated herein by reference.

[0111] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0112] <Method for measuring weight average molecular weight (Mw) and number average molecular weight (Mn)> The weight average molecular weight and number average molecular weight were determined by gel permeation chromatography (GPC) and converted from a calibration curve using standard polystyrene. The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Types: A-2500, A-5000, F-20, F-80) (manufactured by Tosoh Corporation, trade name). The GPC measurement conditions are shown below.

[0113] Apparatus: High-speed GPC apparatus HLC-8320GPC (Tosoh Corporation, trade name) Detector: Ultraviolet absorption detector UV-8320 (Tosoh Corporation, trade name) Columns: Guard column; TSKgel guard column Super (HZ)-M+, column; TSKgel SuperMultipore HZ-M (2 columns), reference column; TSKgel Super H-RC (2 columns) (all Tosoh Corporation, trade names) Column size: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 1 mL Injection volume: 20 μL or 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40°C

[0114] <Production of Compounds> A 500 mL reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet was charged with the amounts of indene shown in Table 1, the following chloromethylstyrene (CMS), α-chloro-p-xylene (CPX), tetra-n-butylammonium bromide (manufactured by Kanto Chemical Co., Inc.) as a phase transfer catalyst, phenothiazine as a polymerization inhibitor, and toluene as a solvent, and the mixture was heated and stirred at 40°C while blowing in nitrogen at a flow rate of 50 mL / min.

[0115] Chloromethylstyrene "CMS-P": AGC Seimi Chemical Co., Ltd., mixture of m- and p-isomers, m-isomer content 50% by mass, p-isomer content 50% by mass.

[0116] Next, the following aqueous sodium hydroxide solution in the amount shown in Table 1 was added dropwise over 20 minutes, and the mixture was stirred at 60°C for an additional 9 hours. Nitrogen was continuously blown in during the reaction. The mixture was cooled to room temperature (25°C) and neutralized with a 10% aqueous hydrochloric acid solution, then washed twice with pure water. The toluene was distilled off under reduced pressure, and the resulting viscous liquid was washed with methanol and then dried in vacuo. In this way, compounds 1 to 7 were obtained.

[0117] Sodium hydroxide aqueous solution: an aqueous solution of sodium hydroxide with a concentration of 48% by mass, manufactured by Kanto Chemical Co., Inc.

[0118]

[0119] Using ECX400II manufactured by JEOL RESONANCE Co., Ltd. １ H-NMR spectrum (0.2 Hz, CDCl ３ , standard substance: tetramethylsilane (TMS)) was measured. １ From the H-NMR analysis, it was found that a reaction had occurred in which a vinylbenzyl group was bonded to one of the 1- to 3-positions of the indene ring, and a methylbenzyl group was bonded to one of the 1- to 3-positions of the indene ring, specifically, a shift or disappearance of the H peak at the 1-position of indene, a shift or disappearance of the H peak at the 2- and 3-positions of indene, a shift in the methylene peaks of CMS and CPX, a shift in the vinyl peak of CMS, and a shift in the methyl peak of CPX. １ The H-NMR spectra are shown in FIGS.

[0120] Furthermore, GPC analysis confirmed that Compounds 1 to 6 were mixtures of compounds having one substituent selected from the group consisting of a vinylbenzyl group and a methylbenzyl group introduced therein (mono-substituted compounds), compounds having two substituents introduced therein (di-substituted compounds), and compounds having three substituents introduced therein (tri-substituted compounds).

[0121] Table 2 shows the yield (%), the proportions (intensity ratio) of tri-, di-, and mono-substituted compounds determined by GPC, the weight-average molecular weight (Mw), and the number-average molecular weight (Mn) for the obtained Compounds 1 to 7.

[0122]

[0123] Examples 1 to 6 and Comparative Example 1 Compounds 1 to 7 obtained above were used in Examples 1 to 6 and Comparative Example 1. Specifically, as shown in Table 3, compound 7 was used in Comparative Example 1, compound 1 was used in Example 1, compound 4 was used in Example 2, compound 5 was used in Example 3, compound 2 was used in Example 4, compound 6 was used in Example 5, and compound 3 was used in Example 6.

[0124] Resin Compositions of Examples 7 to 9 and Comparative Example 2 Resin compositions of Examples 7 to 9 and Comparative Example 2, each having a solids concentration of approximately 60% by mass, were prepared by stirring and mixing the components shown in Table 4 together with toluene at 25°C in the amounts shown in Table 4. In Table 1, when a component is a solution, the mass % is calculated as the solids content.

[0125] Details of each material listed in Tables 3 and 4 are as follows: Compounds 1 to 7: All of the compounds were prepared as described above. Maleimide compound: Aromatic maleimide compound having an indane skeleton represented by the following formula:

[0126] (In the above formula, n is a number from 0.95 to 10.0.)

[0127] <Method for Producing Cured Products> (Examples 1 to 6 and Comparative Example 1) For Comparative Example 1 and Examples 1 to 6, double-sided copper foil-attached resin plates were obtained as follows. A Teflon (registered trademark) sheet, die-cut to a size of 0.8 mm thick x 70 mm long x 50 mm wide, was placed on top of an 18 μm thick low-profile copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., product name: SI-VSP-18), and powders of the compounds (compounds 1 to 7) listed in Table 3 were poured into the die-cut area. Next, an 18 μm thick low-profile copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., product name: SI-VSP-18) was placed on the side of the Teflon (registered trademark) sheet where the compound powder had been poured. The two copper foils were placed with their M-sides (matte sides) in contact with the poured compound powder. Subsequently, the sheet was cured by vacuum heating and pressure molding at a temperature of 230°C, a pressure of 2.0 MPa, and a time of 60 minutes, to obtain double-sided copper foil-attached resin plates. (Examples 7 to 9 and Comparative Example 2) For Comparative Example 2 and Examples 7 to 9, resin boards with copper foil on both sides were obtained as follows. The resin compositions of each Example and Comparative Example obtained above (resin compositions of Examples 7 to 9 and Comparative Example 2) were applied to a 38 μm thick PET film (manufactured by Teijin Limited, product name: G2000), and then heated and dried at 140°C for 5 minutes to produce a B-stage resin film. This resin film was peeled from the PET film and then pulverized to obtain a resin powder. A resin board with copper foil on both sides was obtained using the same procedure as described above (Examples 1 to 6 and Comparative Example 1), except for using the resin powder.

[0128] <Method for Measuring Dielectric Properties (Dielectric Constant (Dk) and Dielectric Loss Tangent (Df))> The resin sheet with copper foil on both sides obtained as described above was immersed in a 10% by mass solution of ammonium persulfate (manufactured by Mitsubishi Gas Chemical Company, Inc.), a copper etching solution, to remove the copper foil on both sides, and 70 mm x 50 mm test pieces were prepared. Next, the dielectric constant (Dk) and dielectric loss tangent (Df) of each test piece were measured at an ambient temperature of 25°C in the 10 GHz band using a split post dielectric resonator (SPDR) for a test piece immediately after drying at 105°C for 1 hour, and for a test piece that had been dried at 105°C for 1 hour and then further left at an ambient temperature of 25°C and 50% RH for 24 hours. The measuring instruments used were a vector network analyzer E8364B manufactured by Agilent Technologies and a 10 GHz SPDR manufactured by Vega Technologies, respectively.

[0129] The results are shown in Tables 3 and 4. In Tables 3 and 4, "Dk immediately after drying" and "Df immediately after drying" indicate the relative dielectric constant (Dk) and dielectric dissipation factor (Df) immediately after drying at 105°C for 1 hour. Furthermore, "Dk after 24 hr" and "Df after 24 hr" indicate the relative dielectric constant (Dk) and dielectric dissipation factor (Df) after drying at 105°C for 1 hour and then leaving the sample at an ambient temperature of 25°C and a humidity of 50% RH for 24 hours. Furthermore, "ΔDf (24 hr - immediately after drying)" indicates the difference in dielectric dissipation factor (Df) before and after leaving the sample at an ambient temperature of 25°C and a humidity of 50% RH for 24 hours.

[0130] <Method for Measuring Thermal Expansion Coefficient> The resin plate with copper foil on both sides obtained as described above was immersed in a 10% by mass solution of ammonium persulfate (manufactured by Mitsubishi Gas Chemical Company, Inc.), a copper etching solution, to remove the copper foil on both sides, and a 5 mm square test piece was prepared. Next, the thermal expansion coefficient of the test piece was measured from 3 to 120°C using a thermomechanical analyzer (TMA) (manufactured by TA Instruments Japan, product name: Q400) in accordance with the IPC (The Institute for Interconnecting and Packaging Electronic Circuits) standard. More specifically, measurements were performed twice in the temperature range of 30 to 260°C under conditions of a load of 5 g and a heating rate of 10°C / min, and the thermal expansion coefficient was taken as the average thermal expansion coefficient over the temperature range of 30 to 120°C in the second measurement. Note that the thermal expansion coefficient is the thermal expansion coefficient in the thickness direction of the resin plate. The results are shown in Tables 3 and 4.

[0131] <Method for Measuring Copper Foil Peel Strength> For Comparative Example 1, Examples 1 to 3, and Example 5, the copper foil peel strength was measured as an index of adhesion to the metal foil. The resin boards with copper foil on both sides obtained as described above were etched to remove the copper foil except for a 3 mm-wide straight line portion, which was used as a test piece. The resulting straight line copper foil was attached to a small tabletop testing machine (Shimadzu Corporation, product name "EZ-TEST") and peeled at a 90° angle at room temperature (25°C) to measure the peel strength. The pulling speed when peeling the copper foil was 50 mm / min. The results are shown in Table 3.

[0132]

[0133]

[0134] As shown in Table 3, Examples 1 to 6 in which compounds 1 to 6 were used had smaller ΔDf (24 hr-immediately after drying) values ​​than Comparative Example 1 in which compound 7 was used, indicating that deterioration of dielectric properties due to moisture absorption was suppressed. Furthermore, as shown in Table 4, Examples 7 to 9 in which resin compositions containing compounds 1, 4, or 5 were used had smaller ΔDf (24 hr-immediately after drying) values ​​than Comparative Example 2 in which compound 7 was used, indicating that deterioration of dielectric properties due to moisture absorption was suppressed.

Claims

1. A compound comprising an indene ring, a vinylbenzyl group, and an aromatic ring-containing group having 6 or more carbon atoms and no polymerizable carbon-carbon double bond, wherein the vinylbenzyl group and the aromatic ring-containing group are each directly bonded to the indene ring.

2. A compound represented by the following formula (1): (In formula (1), R １ ~R ４ R each independently represents a hydrogen atom or a monovalent substituent. １ , R ２ and R ３ At least one of R is a vinylbenzyl group; １ , R ２ and R ３ At least one of the four R's is an aromatic ring-containing group having 6 or more carbon atoms and no polymerizable carbon-carbon double bond. ４ may all be different from each other, and the four R ４ Two or more of them may be the same.) 3. The compound according to claim 1 or 2, wherein the aromatic ring-containing group is an aryl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond, or an arylalkyl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond.

4. The compound according to claim 3, wherein the aromatic ring-containing group is a benzyl group that is unsubstituted or has a substituent that does not have a polymerizable carbon-carbon double bond.

5. A resin composition comprising the compound according to any one of claims 1 to 4.

6. A prepreg comprising the resin composition according to claim 5 or a semi-cured product of said resin composition.

7. A resin film comprising the resin composition according to claim 5 or a semi-cured product of said resin composition.

8. A metal-clad laminate comprising a cured product of the resin composition according to claim 5 and a metal foil.

9. A printed wiring board comprising a cured product of the resin composition according to claim 5.

10. A semiconductor package comprising the printed wiring board according to claim 9 and a semiconductor element.

11. A semiconductor package comprising a semiconductor element and a cured product of the resin composition according to claim 5 that encapsulates the semiconductor element.

12. A printed wiring board comprising at least one of a surface protective film and an interlayer insulating film formed from the resin composition according to claim 5.

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