Aralkyl-modified resin, curable resin material, prepreg, resin film, metal-clad laminate, printed wiring board, and semiconductor package

Abstract

This aralkyl-modified resin contains a vinylbenzyl group and a trimethyl group, the ratio of the integral value of a peak attributable to hydrogen atoms contained in methyl groups in the trimethyl group to the integral value of a peak attributable to β-hydrogen atoms at a trans position of a benzene ring from among hydrogen atoms contained in the vinyl group of the vinylbenzyl group in a 1H-NMR chart being 1.5 or less.

Description

Aralkyl-modified resins, curable resin materials, prepregs, resin films, metal-clad laminates, printed circuit boards, and semiconductor packages 【0001】 This disclosure relates to aralkyl-modified resins, methods for manufacturing resins, curable resin materials, prepregs, resin films, metal-clad laminates, printed circuit boards, and semiconductor packages. 【0002】 In mobile communication devices such as smartphones, their base station equipment, network infrastructure equipment such as servers and routers, various types of computers (personal, industrial, large-scale, etc.), home appliances, automobiles, and other electronic devices, the development of communication technology is leading to faster and larger data transmission speeds and capacities, and there is a need for the development of semiconductor-related materials that can cope with these changes. 【0003】 To accommodate high-speed and high-capacity information transmission in the high-frequency range, development has been underway on semiconductor resin materials with lower dielectric constant and dielectric loss tangent, and lower transmission loss. Patent Document 1 discloses a curable vinylbenzyl compound having an indene ring structure into which vinylbenzyl groups are introduced, which can be cured into a product with excellent low dielectric constant, low dielectric loss tangent, high heat resistance, and low water absorption. 【0004】 Japanese Patent Publication No. 2003-277440 【0005】 In recent years, with the increasing integration of semiconductors, the larger substrate sizes, and the transformation of package structures such as chiplets, the performance requirements for semiconductor resin materials have become even more stringent. Specifically, there is a strong demand for improvements in properties that contribute to connection reliability, such as further improvements in dielectric properties, heat resistance, dimensional stability, and reduction of warping. 【0006】 This disclosure aims to provide aralkyl-modified resins, curable resin materials, prepregs, resin films, metal-clad laminates, printed circuit boards, and semiconductor packages that exhibit excellent heat resistance in cured products. 【0007】 This disclosure includes the following embodiments. This disclosure is not limited to the following embodiments. One embodiment includes a vinylbenzyl group and a tolylmethyl group, １In the H-NMR chart, the ratio of the integral value of the peak attributed to the hydrogen atoms contained in the methyl group in the tolylmethyl group to the integral value of the peak attributed to the β-hydrogen in the trans-position of the benzene ring among the hydrogen atoms contained in the vinyl group of the vinylbenzyl group is 1.5 or less, and relates to an aralkyl-modified resin. 【0008】 According to the present disclosure, it is possible to provide an aralkyl-modified resin, a curable resin material, a prepreg, a resin film, a metal-clad laminate, a printed wiring board, and a semiconductor package that are excellent in heat resistance in a cured product. 【0009】 FIG. 1 is the １ H-NMR spectrum of the aralkyl-modified resin (I) produced in Example 1. FIG. 2 is the １ H-NMR spectrum of the aralkyl-modified resin (II) produced in Example 2. FIG. 3 is the １ H-NMR spectrum of the aralkyl-modified resin (III) produced in Example 3. FIG. 4 is the １ H-NMR spectrum of the aralkyl-modified resin (I') produced in Comparative Example 1. 【0010】 Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments. 【0011】 In the present disclosure, a numerical range indicated using "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value of a certain numerical range may be replaced with the upper limit value or the lower limit value of another numerical range. Further, the upper limit value or the lower limit value of the numerical range described in the present disclosure may be replaced with the value shown in the examples. 【0012】 In the present disclosure, each component may contain one or more corresponding substances unless otherwise specified. 【0013】 In the present disclosure, the content of each component in the curable resin material means the total amount of the plurality of substances present in the curable resin material when there are a plurality of substances corresponding to each component in the curable resin material, unless otherwise specified. 【0014】In the present disclosure, unless otherwise specified, the number average molecular weight (Mn) and weight average molecular weight (Mw) of the resin are measured by gel permeation chromatography (GPC) under the following conditions and are values converted from a calibration curve using standard polystyrene. The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Type; A-2500, A-5000, F-20, F-80) (manufactured by Tosoh Corporation, trade name). 【0015】 Apparatus: High-speed GPC apparatus "HLC-8420GPC" (manufactured by Tosoh Corporation, trade name) Detector: Ultraviolet absorption detector "UV-8420" (manufactured by Tosoh Corporation, trade name) Column: Guard column; TSKgel guardcolumn SuperHZ-L, Column; TSKgel SuperHZ4000 + TSKgel SuperHZ2500 + TSKgel SuperHZ1000 (3 columns), Reference column; None (resistance tube) All manufactured by Tosoh Corporation, trade name) Column size: 4.6 × 20 mm (guard column), 4.6 × 150 mm (column), Eluent: Tetrahydrofuran Sample concentration: 1 mg / 1 mL Injection volume: 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40 °C 【0016】 The aralkyl-modified resin which is one embodiment of the present disclosure contains a vinylbenzyl group and a tolylmethyl group. １ In the 1H-NMR chart, the ratio of the integral value of the peak attributed to the hydrogen atoms contained in the methyl group in the tolylmethyl group (hereinafter sometimes referred to as "methyl hydrogen peak") to the integral value of the peak attributed to the β-hydrogen in the trans-position of the benzene ring among the hydrogen atoms contained in the vinyl group of the vinylbenzyl group (hereinafter sometimes referred to as "trans-position hydrogen peak") is 1.5 or less. It is an aralkyl-modified resin. 【0017】 The β-hydrogen in the trans-position of the benzene ring among the hydrogen atoms contained in the vinyl group of the vinylbenzyl group refers to the hydrogen atom circled in the following structural formula (2). Further, the hydrogen atoms contained in the methyl group in the tolylmethyl group refer to the three hydrogen atoms circled in the following structural formula (3). 【0018】 【0019】 The ratio of the integral values ​​of the trans hydrogen peak and the methyl hydrogen peak was measured using a nuclear magnetic resonance spectrometer with deuterium chloroform as the solvent and under conditions of a resonance frequency of 400 MHz. １ This value is calculated from the H-NMR spectrum. For the nuclear magnetic resonance spectrometer, the "ECX400II" manufactured by JEOL RESONANCE Co., Ltd. is recommended. 【0020】 Aralkyl-modified resins, by containing vinylbenzyl groups and tolylmethyl groups in the resin, become resins with excellent heat resistance and dielectric properties in the cured product, but in particular, １ A ratio of the integral value of the methyl hydrogen peak to the integral value of the trans hydrogen peak in the H-NMR chart of 1.5 or less results in a higher glass transition temperature (Tg) in the cured product. A high glass transition temperature (Tg) in the cured product is an important characteristic as an indicator of heat resistance. Furthermore, aralkyl-modified resins have a high storage modulus in the high-temperature range and a low coefficient of thermal expansion in the cured product, thus possessing excellent dimensional stability. The heat resistance and dimensional stability of the cured product contribute to the reliability of connections when used as a semiconductor resin material. 【0021】 The ratio of the integral value of the methyl hydrogen peak to the integral value of the trans hydrogen peak may be 1.4 or less, or 1.3 or less. Furthermore, in terms of achieving an even better balance between heat resistance and dielectric properties, the ratio of the two integral values ​​may be 0.05 or more, or 0.1 or more. 【0022】The vinylbenzyl group may be any of o-vinylbenzyl, m-vinylbenzyl, or p-vinylbenzyl groups. Among these, p-vinylbenzyl groups or m-vinylbenzyl groups are preferred because they result in a resin with excellent dielectric properties in the cured product, and the resin may contain both p-vinylbenzyl and m-vinylbenzyl groups. The proportion of p-vinylbenzyl groups among the vinylbenzyl groups in the resin may be 10 mol% or more, 20 mol% or more, or 30 mol% or more. It may also be 100 mol% or less, 80 mol% or less, or 70 mol% or less. The proportion of p-vinylbenzyl groups among the vinylbenzyl groups in the resin may be in the range of 10 to 100 mol%. If the proportion of p-vinylbenzyl groups among the vinylbenzyl groups in the resin is less than 100 mol%, the remainder may be m-vinylbenzyl groups. 【0023】 The tolmethyl group may be any of o-tolmethyl, m-tolmethyl, or p-tolmethyl. Among these, p-tolmethyl or m-tolmethyl is preferred because it results in a resin with excellent dielectric properties in the cured product. The proportion of p-tolmethyl groups among the tolmethyl groups in the resin may be 60 mol% or more, 80 mol% or more, 90 mol% or more, or 100 mol%. 【0024】 The molecular weight of the aralkyl-modified resin is not particularly limited and may be adjusted as appropriate depending on the desired application. For example, when used in applications where the resin is impregnated into a fiber substrate, such as prepregs and metal-clad laminates, the number average molecular weight (Mn) is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less, due to its excellent impregnation properties. The lower limit is not particularly limited, but it is preferably 250 or more. The number average molecular weight (Mn) of the aralkyl-modified resin may be in the range of 250 to 3,000. 【0025】The specific structure of the aralkyl-modified resin is not particularly limited and may be a structure according to the desired use or the like. As an example of the specific structure, in terms of becoming a resin with more excellent dielectric properties in the cured product, in addition to the vinylbenzyl group and the tolylmethyl group, it is preferable to contain an indene skeleton. The vinylbenzyl group, the tolylmethyl group, and the indene skeleton may be contained in any form in the aralkyl-modified resin. For example, the aralkyl-modified resin may contain a vinylbenzyl group bonded to the indene skeleton and a tolylmethyl group bonded to the indene skeleton. 【0026】 As an example of the case where the aralkyl-modified resin contains an indene skeleton, for example, the aralkyl-modified resin contains at least two compounds having different structures among the compounds represented by the following general formula (1), and R １ , R ２ and R ３ Among them, at least one is a vinylbenzyl group, and R １ , R ２ and R ３ Among them, at least one may be a tolylmethyl group (hereinafter, this is also referred to as "aralkyl-modified resin (1)"). 【0027】 【0028】 [In the general formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom, a vinylbenzyl group, or a tolylmethyl group. R ４ represents a monovalent substituent, and n is an integer of 0 or 1 to 4. When n is an integer of 2 or more, a plurality of R ４ existing in the formula may all be different, or some or all may be the same. ] 【0029】 R ４is a monovalent substituent. Examples of monovalent substituents include halogen atoms, alkyl groups, and alkoxy groups. Specific examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Alkyl groups may be linear or branched. The number of carbon atoms in an alkyl group is not particularly limited, but may be in the range of 1 to 6. Examples of alkyl groups with 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, pentyl, isopentyl, neopentyl, hexyl, and cyclohexyl groups. Alkyl groups may be alkyl groups with 1 to 3 carbon atoms, and may also be methyl groups. Examples of alkoxy groups include groups represented as R-O- where R is the alkyl group described above. In general formula (1), n ​​may be 0. 【0030】 Examples of compounds represented by general formula (1) include R in general formula (1). １ , R ２ and R ３ Compounds in which each is a vinylbenzyl group or a tolylmethyl group (hereinafter sometimes referred to as "trisubstituted compounds"), R in general formula (1) １ , R ２ and R ３ Compounds in which each is a vinylbenzyl group or a tolylmethyl group (hereinafter sometimes referred to as "trisubstituted compounds"), R in general formula (1) １ , R ２ and R ３ A compound in which one of the atoms is a hydrogen atom and the other two are vinylbenzyl groups or tolylmethyl groups, respectively (hereinafter sometimes referred to as a "disubstituted compound"), R in general formula (1) １ , R ２ and R ３ Examples include compounds in which two of the atoms are hydrogen atoms and the remaining one is a vinylbenzyl group or a tolylmethyl group (hereinafter sometimes referred to as "monosubstituted compounds"). 【0031】 Aralkyl-modified resin (1) is １As long as the ratio of the integral value of the methyl hydrogen peak to the integral value of the trans hydrogen peak in the H-NMR chart is 1.5 or less, the content of each compound is not particularly limited. For example, the area ratio of the trisubstituted compound in the GPC chart may be 60% or more, 70% or more, or 75% or more. It may also be 95% or less, 90% or less, or 85% or less. The area ratio of the trisubstituted compound in the GPC chart of the aralkyl-modified resin (1) may be in the range of 60 to 95%. 【0032】 The area ratio of the disubstituted product in the GPC chart may be 5% or more, 10% or more, or 15% or more. It may also be 30% or less, 25% or less, or 20% or less. The area ratio of the disubstituted product in the GPC chart of the aralkyl-modified resin (1) may be in the range of 5 to 30%. 【0033】 The area ratio of monosubstituted material in the GPC chart is preferably small, as this results in a resin with superior heat resistance and low thermal expansion in the cured product. For example, it may be 1.5% or less, 1% or less, or 0.5% or less. The lower limit is not particularly limited, but may be 0.05% or more, or 0.1% or more. The area ratio of monosubstituted material in the GPC chart of the aralkyl-modified resin (1) may be in the range of 0.05 to 1.5%. 【0034】 The GPC conditions used to calculate the area ratio of each compound in the GPC chart of the aralkyl-modified resin (1) are the same as those used for the molecular weight measurement of the resin described above. 【0035】 The method for producing the aralkyl-modified resin (1) is not particularly limited, and it can be produced, for example, by reacting a vinyl benzylating agent and a tolyl methylating agent with a base compound that forms the basic structure of the resin. The base compound, vinyl benzylating agent, and tolyl methylating agent may be used individually or in combination of two or more. 【0036】Examples of vinylbenzylating agents include compounds represented by the following general formula (4). Examples of tolylmethylating agents include compounds represented by the following general formula (5). 【0037】 【0038】 [In general formulas (4) and (5), X is a leaving group.] 【0039】 In general formulas (4) and (5), X is a leaving group, such as a halogen atom or a tosyl group. 【0040】 In general formula (4), the vinyl group on the benzene ring and -CH ２ The substitution position with the -X group is not particularly limited and may be located in the ortho, para, or meta position relative to each other. In particular, the vinyl group and -CH are used to form a resin with excellent dielectric properties in the cured product. ２ - A compound in which the X group is in the para position (hereinafter sometimes referred to as a "para compound") or a vinyl group and -CH ２ Compounds in which the -X group is in the meta position (hereinafter sometimes referred to as "meta-compounds") are preferred. Furthermore, para-compounds and meta-compounds may be used in combination. The proportion of para-compounds in the vinyl benzylate may be 10 mol% or more, 20 mol% or more, or 30 mol% or more. It may also be 100 mol% or less, 80 mol% or less, or 70 mol% or less. The proportion of para-compounds in the vinyl benzylate may be in the range of 10 to 100 mol%. If the proportion of para-compounds in the vinyl benzylate is less than 100 mol%, the remainder consists of a vinyl group and -CH ２ The compound may also have the -X group in the meta position. 【0041】 In general formula (5), the methyl group on the benzene ring and -CH ２ The substitution position with the -X group is not particularly limited and may be located in the ortho, para, or meta position relative to each other. In particular, the methyl group and -CH group are used to form a resin with excellent dielectric properties in the cured product. ２Compounds in which the -X group is in the para position (hereinafter sometimes referred to as "para-isomer compounds") or in the meta position are preferred. The proportion of the para-isomer compound in the tolylmethylating agent may be 60 mol% or more, 80 mol% or more, 90 mol% or more, or 100 mol%. 【0042】 The base compound is not particularly limited as long as it is a compound that has reaction sites with a vinyl benzylating agent and a tolylmethylating agent, and a wide variety of compounds can be used. For example, in the case of aralkyl-modified resin (1), the base compound can be an indene compound represented by the following general formula (6). 【0043】 [In general formula (6), R ４ R represents a monovalent substituent, and n is 0 or an integer from 1 to 4. If n is an integer of 2 or more, there are multiple R in the formula. ４ They may all be different, or some or all of them may be the same. 【0044】 R in general formula (6) ４ and n are R in general formula (1) ４ This is synonymous with n. 【0045】 In the reaction raw materials for the aralkyl-modified resin (1), there are no restrictions on the reaction ratios of the indene compound, vinyl benzylating agent, and tolyl methylating agent, １ The following reaction ratios may be used, as they facilitate adjusting the ratio of the integral value of the methyl hydrogen peak to the integral value of the trans hydrogen peak in the 1H-NMR chart to 1.5 or less. 【0046】 The ratio of the total number of moles of vinyl benzylate and tolyl methylating agent to one mole of indene compound may be 2 moles or more, 2.3 moles or more, 2.5 moles or more, or 2.8 moles or more. Furthermore, there is no particular upper limit, but from the viewpoint of industrial production efficiency, it is preferable not to use more reaction raw materials than necessary, for example, it may be 3 moles or less. The ratio of the total number of moles of vinyl benzylate and tolyl methylating agent to one mole of indene compound may be in the range of 2 to 3 moles. 【0047】 The ratio of vinyl benzylating agent to 1 mole of indene compound may be 1.5 moles or more, 1.8 moles or more, 2 moles or more, or 2.5 moles or more. Alternatively, it may be 2.9 moles or less, 2.7 moles or less, or 2.5 moles or less. The ratio of vinyl benzylating agent to 1 mole of indene compound may be in the range of 1.5 to 2.9 moles. 【0048】 The ratio of tolylmethyl groups to one mole of indene compound may be 0.05 moles or more, 0.2 moles or more, or 0.5 moles or more. It may also be 1 mole or less, 0.8 moles or less, 0.5 moles or less, or 0.3 moles or less. This is particularly preferred. The ratio of tolylmethyl groups to one mole of indene compound may be in the range of 0.05 to 1 mole. 【0049】 The ratio of vinyl benzylating agent to the total number of moles of vinyl benzylating agent and tolyl methylating agent may be 60 mol% or more, 70 mol% or more, 85 mol% or more, or 90 mol% or more. It may also be 99 mol% or less, 95 mol% or less, or 80 mol% or less. The ratio of vinyl benzylating agent to the total number of moles of vinyl benzylating agent and tolyl methylating agent may be in the range of 60 to 99 mol%. 【0050】The method for reacting the reaction materials of the aralkyl-modified resin (1) is not particularly limited, but for example, it can be a method in which the reaction is carried out in the presence of a basic compound. The reaction materials may all be reacted at once, or they may be reacted in several stages. More specifically, examples include a method in which the indene compound, vinyl benzylating agent and tolyl methylating agent are reacted at once, a method in which the indene compound and vinyl benzylating agent are reacted first and then the tolyl methylating agent is reacted, and a method in which the indene compound and vinyl benzylating agent are reacted first and then the vinyl benzylating agent is reacted. Among these, the method in which the indene compound, vinyl benzylating agent and tolyl methylating agent are reacted at once, or the method in which the indene compound and vinyl benzylating agent are reacted first and then the tolyl methylating agent is reacted, is preferred because it results in a resin with superior heat resistance and low thermal expansion in the cured product. 【0051】 Examples of basic compounds include alkali metal hydroxides and alkali metal alkoxides. A single basic compound may be used, or two or more may be used in combination. Furthermore, the basic compound may be used in solid form or as an aqueous solution. 【0052】A phase-transfer catalyst may be used in the above reaction. One type of phase-transfer catalyst may be used alone, or two or more types may be used in combination. Examples of phase transfer catalysts 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 bisulfate; and quaternary phosphonium salts such as tetra-n-butylphosphonium chloride, tetra-n-butylphosphonium bromide, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, benzyltriphenylphosphonium chloride, and benzyltriphenylphosphonium bromide. 【0053】Polymerization inhibitors may be used in the above reaction. One type of polymerization inhibitor may be used alone, or two or more types may be used in combination. Examples of polymerization inhibitors include hydroquinone, methyl hydroquinone, tert-butylhydroquinone, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, hydronoquinone 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, 4-tert-butylcatechol, pyrogallol, 4-methoxyphenol, etc. Examples include phenol or benzoquinone compounds; phenothiazine compounds such as phenothiazine, 3,7-dioctylphenothiazine, and 3,7-dicumylphenothiazine; and compounds having a 2,2,6,6-tetramethylpiperidine structure such as 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, and bis(2,2,6,6-tetramethyl-4-piperidyl-1-oxyl) sebacate. 【0054】 The above reaction may be carried out in a solvent. Examples of solvents include aromatic hydrocarbon solvents such as toluene and xylene. One type of solvent may be used alone, or two or more types may be used in combination. 【0055】 The reaction is preferably carried out under heating conditions to allow the reaction to proceed more efficiently, for example, by heating to a temperature range of 30 to 70°C. 【0056】 After the reaction is complete, the product may be purified as needed by known methods such as concentration, reprecipitation, and washing. 【0057】 The aralkyl-modified resin may have a glass transition temperature (Tg) of 220°C or higher, 230°C or higher, 240°C or higher, 280°C or higher, or 300°C or higher, as measured under the following conditions. Furthermore, there is no particular upper limit, but it may be, for example, 370°C or lower. 【0058】 [Measurement conditions for glass transition temperature (Tg)] Apparatus: Dynamic viscoelasticity analyzer (DMA) (Rheogel-E4000, manufactured by UBM Co., Ltd.) Sample: Resin was vacuum heated and pressure molded at 150°C, 1.5-2.0 MPa for 120 minutes, and then further heat-molded at 180°C for 300 minutes. The sample size was 1 mm thick, 30 mm long, and 5 mm wide. Measurement conditions: Tensile mode, heating rate 5°C / min, the peak temperature of tanδ was taken as the glass transition temperature (Tg). 【0059】 The aralkyl-modified resin may have an average thermal expansion coefficient of 1.8% or less, 1.5% or less, or 1.3% or less, as measured under the following conditions. The lower limit is not particularly limited, but may be, for example, 1.1% or more. 【0060】 [Measurement Conditions for Average Thermal Expansion Coefficient] Equipment: Thermomechanical analyzer (TMA) (Q400 manufactured by T.A. Instrument Japan Co., Ltd.) Sample: Resin is vacuum heated and pressure molded at 150°C, 1.5-2.0 MPa for 120 minutes, and then further heat-molded at 180°C for 300 minutes. The sample size is 1 mm thick, 5 mm long, and 5 mm wide. Measurement conditions: Two measurements are performed under the conditions of a temperature range of 30-260°C, a load of 5 g, and a heating rate of 10°C / min. The average thermal expansion coefficient in the thickness direction of the test piece in the temperature range of 30-260°C in the second measurement is taken as the average thermal expansion coefficient of the resin. 【0061】 [Curable Resin Material] A curable resin material according to one embodiment of the present disclosure includes the aralkyl-modified resin described above. Other components that the curable resin material may contain besides the aralkyl-modified resin include, for example, other curable compounds, elastomers, fillers, curing accelerators, flame retardants, polymerization inhibitors, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, lubricants, solvents, etc. Each of these other components may be used individually or in combination of two or more types. 【0062】Other curable compounds include, for example, compounds having polymerizable unsaturated bonds, epoxy resins, phenolic resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, dicyclopentadiene resins, silicone resins, triazine resins, melamine resins, and the like. Examples of compounds having polymerizable unsaturated bonds include compounds having maleimide groups, polyarylene ether compounds having polymerizable unsaturated bond-containing groups, styrene, divinylbenzene, triallyl isocyanurate, and the like. 【0063】 Examples of compounds having a maleimide group include bismaleimide compounds and maleimide resins. 【0064】Specific examples of bismaleimide compounds include, for example, N,N'-ethylenebismaleimide, N,N'-hexamethylenebismaleimide, 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, and 3,3'-dimethyl-5,5'-die Tyl-4,4'-diphenylmethanebismaleimide, 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]propane , 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-maleimoidphenoxy)biphenyl, bis[4-(3-maleimoidphenoxy)phenyl]ketone, bis[4-(4-maleimoidphenoxy)phenyl]ketone, bis(4-maleimoidphenyl)disulfide, bis[4-(3-maleimoidphenoxy)phenyl]sulfide, bis[4-(4-maleimoidphenoxy)phenyl]sulfide, bis[4-(3-maleimoidphenoxy)phenyl]sulfoxide, bi 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)- Examples include 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, polyphenylmethanemaleimide, aromatic bismaleimide compounds having an indane skeleton, and biphenylaralkyl-type maleimide compounds. 【0065】 Specific examples of maleimide resins include, for example, polyphenylmethane maleimide, maleimide resins having an indan skeleton, and biphenyl aralkyl type maleimide resins. 【0066】 Maleimide resins having an indan skeleton include, for example, those represented by the following general formula (7). 【0067】 【0068】 [R in general formula (7)] ５ [where p is a hydrogen atom or a methyl group, and p is an integer greater than or equal to 1.] 【0069】 Examples of biphenylaralkyl-type maleimide resins include those represented by the following general formula (8). 【0070】 【0071】 [In general formula (8), q is an integer greater than or equal to 1.] 【0072】 Regarding polyarylene ether compounds having polymerizable unsaturated bond-containing groups, the arylene group is not particularly limited and examples include phenylene groups, naphthylene groups, and structures in which one or more alkyl groups, alkyloxy groups, halogen atoms, etc., are substituted on the aromatic carbons thereof. Examples of polymerizable unsaturated bond-containing groups include vinyl groups, vinyloxy groups, allyl groups, allyloxy groups, (meth)acryloyl groups, (meth)acryloyloxy groups, vinylbenzyl groups, vinylbenzyloxy groups, etc. Polyarylene ether compounds having polymerizable unsaturated bond-containing groups may have structural parts other than the polyarylene ether structure. Specifically, they may have acrylic polymerization sites, (poly)urethane sites, (poly)ester sites, etc., in their molecular chains. The number of polymerizable unsaturated bond-containing groups in one molecule of a polyarylene ether compound is not particularly limited, nor are the substitution positions of the polymerizable unsaturated bond-containing groups particularly limited. For example, polyarylene ether compounds may have polymerizable unsaturated bond-containing groups at their molecular ends, or they may have polymerizable unsaturated bond-containing groups at both ends. 【0073】 Specific examples of polyarylene ether compounds having polymerizable unsaturated bond-containing groups include, for example, compounds represented by the following general formula (9). 【0074】 [In general formula (9), R ６ R is a hydrogen atom or a methyl group. 7is one of the following: vinylbenzyl group, acryloyl group, or methacryloyl group. r and s are integers of 1 or greater. Y is a directly bonded or divalent organic group. 【0075】 In general formula (9), Y is either a direct bond or a divalent organic group. The specific structure of the divalent organic group is not particularly limited, but examples include hydrocarbon groups having 1 to 6 carbon atoms, halogenated hydrocarbon groups, oxygen atoms, sulfur atoms, carbonyl groups, sulfonyl groups, etc. 【0076】 The molecular weight of the polyarylene ether compound having radical polymerizable groups is not particularly limited, but for example, the number average molecular weight (Mn) may be in the range of 1,000 to 5,000. 【0077】 The ratio of aralkyl modification to the total mass of the curable components of the curable resin material is arbitrary, but may be, for example, 10% by mass or more, 30% by mass or more, 50% by mass or more, 80% by mass or more, or 100% by mass. 【0078】 Examples of elastomers include polyether-based elastomers, styrene-based elastomers, conjugated diene-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers. 【0079】 Both organic and inorganic fillers can be used as fillers, but inorganic fillers are preferred. Examples of inorganic fillers include silica (SiO₂). ２ ), alumina (Al ２ O ３ Examples include titanium dioxide, barium titanate, strontium titanate, potassium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, aluminum borate, silicon carbide, mica, beryllia, clay, and talc. From the viewpoint of dielectric properties, silica is preferred. 【0080】The shape and size of the filler are not particularly limited. The average particle diameter of the filler may be, for example, 0.01 to 20 μm, or 0.1 to 10 μm. Here, the average particle diameter of the filler is the particle diameter at the point corresponding to 50% of the cumulative value in the volume-based particle distribution obtained by laser diffraction scattering. 【0081】 As a 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. Specific examples of polymerization initiators include azo polymerization initiators and organic peroxide polymerization initiators. Examples of azo polymerization initiators include 2,2'-azobis(2,4,4-trimethylpentane), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 1,1'-azobis(cyclohexane-1-carbonitride), and dimethyl-1,1'-azobis(1-cyclohexanecarboxylate). Examples 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(2,4-dimethylvaleronitrile), and 4,4'-azobis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl4-cyanopentanoate). 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, α,α'-di(t-butylperoxy)diisopropylbenzene, and tert-butyl hydroperoxide. 【0082】 Examples of flame retardants include phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, and inorganic flame retardants. 【0083】The curable resin material may be solvent-free or may contain a solvent. The solvent can adjust the viscosity of the curable resin material and further improve its coating properties. Organic solvents are preferred as the solvent. 【0084】 Examples of organic solvents 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. 【0085】 The method for producing a curable resin material is not particularly limited. One example of a method for producing a curable resin material is to add and mix aralkyl modification and optional components as needed. When mixing, the aralkyl modification and optional components may be added and mixed as they are, or they may be dissolved or dispersed in a solvent before mixing. The mixing order of each component, temperature, time, and other conditions are not particularly limited and may be adjusted as appropriate according to the type of raw materials, production scale, production equipment, etc. 【0086】 [Prepreg] According to one embodiment, a prepreg containing a semi-cured product of a curable resin material or curable composition can be provided. This prepreg can be formed, for example, using a curable resin material and a fibrous substrate. With respect to the semi-cured product of the curable resin material, in this disclosure, the B-stage state in JIS K 6800 (1985) can be cited as one indicator of the semi-cured state. The prepreg may contain, for example, a curable resin material or a semi-cured product of a curable resin material and a fibrous substrate such as a sheet-like fibrous substrate. In the prepreg, the curable resin material may be in an uncured state, or it may be in a partially or entirely semi-cured state. 【0087】A prepreg can be obtained, for example, by impregnating a fibrous substrate with a curable resin material and drying the fibrous substrate impregnated with the curable resin material. Drying is preferably carried out at a temperature above which volatile components such as solvents that may be contained in the curable resin material are removed, and may also be carried out at a temperature above which the curable components contained in the curable resin material are partially cured, depending on the application. Furthermore, it is preferable that the drying is adjusted so that the thermosetting resin contained in the curable resin material is not completely cured. From this viewpoint, 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, and its scale. 【0088】 The fibrous base material may be woven, knitted, or nonwoven fabric. The fibrous base material may be provided in the form of chopped strand mat, roving, etc. The fiber material may be either inorganic or organic. Examples of inorganic fibers include glass fibers and carbon fibers. Examples of glass fibers include E-glass, NE-glass, D-glass, S-glass, and Q-glass. Examples of organic fibers include polyimide, polyester, and tetrafluoroethylene. The fibrous base material may use one type of fiber alone or a combination of two or more types. From the viewpoint of dielectric properties and heat resistance, inorganic fibers are preferred for the fibrous base material, and glass fibers are more preferred. 【0089】 The fibrous substrate can be appropriately selected depending on the application of the prepreg, but a sheet-like fibrous substrate is preferred. The sheet-like fibrous substrate may be, for example, various sheet-like fibrous substrates used in known laminates for electrical insulating materials. The thickness of the sheet-like fibrous substrate is not particularly limited, but for example, 0.01 to 0.1 mm is preferred. Here, the thickness is determined by measuring the thickness at five points at equal distances across the entire surface of the sheet-like fibrous substrate and taking the arithmetic mean of the five points. 【0090】[Resin Film] According to one embodiment, a resin film can be provided that includes a curable resin material or a semi-cured product of the curable resin material. The resin film can be obtained, for example, by coating a material to be coated with a curable resin material and drying or semi-curing it. Drying or semi-curing can be carried out in the same manner as the manufacturing method of the prepreg described above. After drying the resin film on the material to be coated, the product may be provided as a combination of the resin film and the material to be coated. For example, in this method, the resin film can be provided as a surface protective film, an interlayer insulating film, etc., in a printed circuit board. In another method, after drying the resin film on the material to be coated, the resin film may be peeled off the material to provide the resin film as a product. 【0091】 The material to be coated may be either an inorganic or organic substrate, and examples include glass substrates, metal foils, metal plates and other metal substrates, plastic plates, plastic films and other plastic substrates, paper substrates, and even fibrous substrates as described in the prepreg section above. In order to peel the resin film from the material to be coated and provide it, a material to be coated that has a release layer formed on its surface may be used. 【0092】 [Metal-clad laminate] According to one embodiment, a metal-clad laminate can be provided, comprising a cured product of a curable resin material and a metal foil. With respect to the cured product of the curable resin material, in this disclosure, the state of the C-stage in JIS K 6800 (1985) can be cited as one indicator of the cured product. 【0093】In a metal-clad laminate, the cured product of the curable resin material may be included as the cured product of the curable resin material itself, or it may be included in the form of a prepreg. Preferably, the metal-clad laminate includes a prepreg layer and a metal foil placed on at least one surface of the prepreg layer. The prepreg layer is the cured product of the prepreg described above, and may consist of a single prepreg or multiple prepregs laminated together. Furthermore, the metal-clad laminate may have the metal foil placed on one surface of the cured prepreg, or it may have the metal foil placed on both surfaces of the cured prepreg. The metal-clad laminate may be manufactured by placing the metal foil on at least one surface of a single sheet-like prepreg, or by laminating two or more sheet-like prepregs and placing the metal foil on at least one surface of the outermost layer of the laminate. The metal-clad laminate may be manufactured by laminating two or more sheet-like prepregs and placing the metal foil on both surfaces of this laminate. 【0094】 The following describes a specific method for manufacturing metal-clad laminates, which involves arranging metal foil on a laminate of two or more sheet-like prepregs. 【0095】 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, or they may be partially or completely different. In the laminate, it is sufficient that at least one of the two or more sheet-like prepregs is obtained using a curable resin material according to one embodiment. 【0096】Next, a metal foil is placed on at least one surface of the laminate. The laminate with the metal foil is then heated and pressurized. This causes the sheet-like prepreg to harden, and a hardened prepreg product can be obtained. Adjacent sheet-like prepregs can also be bonded together. The heating and pressurizing conditions are not particularly limited, but for example, the temperature can be 100 to 300°C, the time 10 to 300 minutes, and the pressure 0.5 to 50 MPa. After heating and pressurizing, reheating may be performed to further harden the prepreg. In this case, the reheating temperature can be 100 to 300°C. As for the pressurizing method, for example, an autoclave molding machine, a multi-stage press machine, a multi-stage vacuum press machine, a continuous molding machine, etc., can be used. 【0097】 The metal used for the metal foil is not particularly limited and can include, for example, copper, nickel, aluminum, gold, silver, platinum, molybdenum, ruthenium, tungsten, iron, titanium, chromium, and alloys containing two or more of these metal elements. Industrially, it is preferable to use elemental copper, nickel, or aluminum. By using copper as the metal foil, a copper-clad laminate can be provided. 【0098】 [Printed Wiring Board] According to one embodiment, a printed wiring board containing a cured product of a curable resin material can be provided. In the printed wiring board, the cured product of the curable resin material may be included as the cured product of the curable resin material itself, or it may be included in the form of a prepreg. The printed wiring board can be manufactured using a curable resin material, a prepreg, a metal-clad laminate, or a combination thereof. For example, a printed wiring board can be provided by forming wiring using a metal-clad laminate by a known method. Details of the prepreg and metal-clad laminate are as described above. The printed wiring board may be either a single-layer printed wiring board or a multi-layer printed wiring board. 【0099】[Semiconductor Package] According to one embodiment, a semiconductor package can be provided that includes a printed circuit board and semiconductor elements. More specifically, for example, a semiconductor package can be provided that includes a printed circuit board containing a cured prepreg and semiconductor elements. The semiconductor package can be manufactured, for example, by mounting semiconductor elements, memory, etc., on a printed circuit board by a known method. 【0100】 A curable resin material according to one embodiment can be used in prepregs, resin films, and metal-clad laminates. A curable composition according to one embodiment can be used in encapsulants, surface protective films, interlayer insulating films, etc. For example, a semiconductor package containing a cured product of the curable composition according to one embodiment can be provided as a cured product for encapsulating semiconductor elements. In another example, a printed circuit board can be provided containing at least one of a surface protective film and an interlayer insulating film formed by the curable composition according to one embodiment. These articles have low dielectric constant and low dielectric loss tangent, while also exhibiting excellent flame retardancy, thus further enhancing product reliability. 【0101】 Examples of embodiments are given below. The present invention is not limited to the following embodiments. <1> comprising a vinylbenzyl group and a tolylmethyl group, １ An aralkyl-modified resin in which, in an H-NMR chart, the ratio of the integral value of the peak attributed to the hydrogen atoms contained in the methyl group of the tolylmethyl group to the integral value of the peak attributed to the β-hydrogen in the trans position of the benzene ring among the hydrogen atoms contained in the vinyl group of the vinylbenzyl group is 1.5 or less. 【0102】 <2> The aralkyl-modified resin according to <1>, comprising a vinylbenzyl group bonded to the indene skeleton and a tolylmethyl group bonded to the indene skeleton. 【0103】 <3> The aralkyl-modified resin according to <1> or <2> above, wherein the number-average molecular weight (Mn) is in the range of 250 to 3,000. 【0104】 <4> The resin contains at least two compounds with different structures from the compounds represented by the following general formula (1), and R is present in the resin. １ , R２ and R ３ The aralkyl-modified resin according to any one of <1> to <3> above, wherein at least one of the groups is a vinylbenzyl group and at least one is a tolylmethyl group. 【0105】 【0106】 [In general formula (1), R １ , R ２ and R ３ Each of these is independently a hydrogen atom, a vinylbenzyl group, or a tolylmethyl group. ４ R represents a monovalent substituent, and n is 0 or an integer from 1 to 4. If n is an integer of 2 or more, there are multiple R in the formula. ４ They may all be different, or some or all of them may be the same. 【0107】 <5> A curable resin material comprising the aralkyl-modified resin described in any one of <1> to <4> above. 【0108】 <6> A prepreg comprising the curable resin material or a semi-cured product of the curable resin material described in <5> above. 【0109】 <7> A resin film comprising the curable resin material described in <5> above or a semi-cured product of the curable resin material. 【0110】 <8> A metal-clad laminate comprising a cured product of the curable resin material described in <5> above and a metal foil. 【0111】 <9> A printed circuit board comprising a cured product of the curable resin material described in <5> above. 【0112】 <10> A semiconductor package comprising the printed circuit board described in <9> above and a semiconductor element. 【0113】 <11> A semiconductor package comprising a semiconductor element and a cured product of the curable resin material described in <5> for sealing the semiconductor element. 【0114】 <12> A printed circuit board comprising at least one of a surface protective film and an interlayer insulating film formed from the curable resin material described in <5> above. 【0115】The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. 【0116】 [Examples 1-3 and Comparative Example 1] Aalkyl-modified resins (I) to (III) and (I') were manufactured according to the following procedure, and various evaluation tests were performed. 【0117】 [Production of Aalkyl-Modified Resins (I) to (III) and (I')] A 500 ml reaction vessel equipped with a stirrer, thermometer, reflux tubing, and nitrogen inlet was charged with the amounts shown in Table 1 below: indene, chloromethylstyrene (*1), tetra-n-butylammonium bromide as a phase transfer catalyst, phenothiazine and bis(2,2,6,6-tetramethyl-4-piperidyl-1-oxyl) sebacate as polymerization inhibitors, and toluene as a solvent. The mixture was heated and stirred at 40°C while blowing nitrogen at a flow rate of 50 ml / min. Next, the amount shown in Table 1 of aqueous sodium hydroxide solution (48% by mass) was added. The reaction was carried out at 70°C. １ After confirming the disappearance of chloromethylstyrene by 1H-NMR spectroscopy, the amount of α-chloro-p-xylene shown in Table 1 was added. The reaction was then carried out at 70°C. １ The reaction was terminated after confirming the disappearance of α-chloro-p-xylene by 1H-NMR spectroscopy. Nitrogen was continuously blown into the mixture during the reaction. The reaction mixture, cooled to room temperature (25°C), was neutralized with a 10% hydrochloric acid aqueous solution, washed twice with pure water, and toluene was removed by vacuum distillation. The resulting viscous liquid was washed with methanol and then vacuum dried to obtain aralkyl-modified resins (I) to (III) and (I'). 【0118】 (*1): AGC Seimi Chemical Co., Ltd. "CMS-P", a mixture of m-isomer and p-isomer, m-isomer content 50% by mass, p-isomer content 50% by mass 【0119】 In the production of aralkyl-modified resins (I) to (III) and (I'), １ The 1H-NMR spectrum was measured using the "ECX400II" manufactured by JEOL RESONANCE Co., Ltd., with deuterium chloroform as the solvent, under conditions of a resonance frequency of 400 MHz. 【0120】 [Aralkyl-modified resin] １[H-NMR Analysis] For aralkyl-modified resins (I) to (III) and (I'), under the same conditions as above. １ When the 1H-NMR spectrum was measured, a shift or disappearance of the starting material peak was observed, indicating that a vinylbenzyl group was bonded to one of the 1st to 3rd positions of the indene ring, and a methylbenzyl group was bonded to one of the 1st to 3rd positions of the indene ring. Aalkyl-modified resins (I) to (III) and (I') １ The 1H-NMR spectra are shown in Figures 1 to 4. 【0121】 Aralkyl-modified resins (I) to (III) and (I') １ Table 1 shows the ratio of the integral value of the peaks attributed to the hydrogen atoms in the methyl group of the tolylmethyl group to the integral value of the peaks attributed to the β-hydrogen at the trans position of the benzene ring, calculated from the H-NMR spectrum ([methyl hydrogen peak] / [trans position hydrogen peak]). 【0122】 [Manufacturing of Cured Aalkyl-Modified Resin] A low-profile copper foil ("SI-VSP-18" manufactured by Mitsui Mining & Smelting Co., Ltd., 18 μm thick) was placed with the S-side (shiny side) facing upwards, and a Teflon® sheet, cut to a size of 1.0 mm thickness x 20 mm length x 20 mm width, was placed on top of it. Next, aralkyl-modified resin was poured into the cut-out section, and the low-profile copper foil was placed on top of it with the S-side (shiny side) facing downwards (resin side). The resin was cured by vacuum heating and pressure molding at a temperature of 110°C, a pressure of 1.5 to 2.0 MPa, and a time of 60 minutes, and then by further vacuum heating and pressure molding at a temperature of 230°C, a pressure of 1.5 to 2.0 MPa, and a time of 60 minutes. After that, the copper foil on both sides was peeled off to obtain a cured product (thickness of cured product: 1 mm). 【0123】 [Measurement of Glass Transition Temperature (Tg) of Cured Material] A 30 mm long, 5 mm wide test piece was cut from the cured material obtained earlier, and dynamic viscoelasticity measurement (DMA) was performed using a Rheogel-E4000 manufactured by UBM Co., Ltd. The measurement conditions were tensile mode with a heating rate of 5°C / min. The glass transition temperature (Tg) was determined from the tanδ peak. 【0124】[Evaluation of Thermal Expansion Coefficient of Cured Material] A 5 mm square test specimen was cut from the cured material obtained earlier, and the thermal expansion coefficient from 30 to 120°C was measured using a thermomechanical analyzer (TMA) (Q400, manufactured by T.A. Instrument Japan Co., Ltd.). The measurement was performed twice in accordance with the IPC (The Institute for Interconnecting and Packaging Electronic Circuits) standard, under the conditions of a temperature range of 30 to 260°C, a load of 5 g, and a heating rate of 10°C / min. The average thermal expansion coefficient in the thickness direction of the test specimen in the temperature range of 30 to 260°C in the second measurement was calculated. 【0125】 【0126】 As shown in Table 1, the aralkyl-modified resins (I) to (III) of Examples 1 to 3, in which the [methyl hydrogen peak] / [trans hydrogen peak] value was 1.5 or less, exhibited a higher glass transition temperature (Tg) and superior heat resistance of the cured product compared to the aralkyl-modified resin (I') of Comparative Example 1, in which the value was 1.9. Furthermore, they exhibited a lower coefficient of thermal expansion and superior dimensional stability. 【0127】 The disclosures of this application are related to the subject matter described in Japanese Patent Application No. 2024-217560, filed on 12 December 2024, the disclosures of which are incorporated herein by reference.

Claims

It contains a vinylbenzyl group and a tolylmethyl group, １ An aralkyl-modified resin in which, in an H-NMR chart, the ratio of the integral value of the peak attributed to the hydrogen atoms contained in the methyl group of the tolylmethyl group to the integral value of the peak attributed to the β-hydrogen in the trans position of the benzene ring among the hydrogen atoms contained in the vinyl group of the vinylbenzyl group is 1.5 or less. 　 The aralkyl-modified resin according to claim 1, comprising a vinylbenzyl group bonded to the indene skeleton and a tolylmethyl group bonded to the indene skeleton. The aralkyl-modified resin according to claim 1, wherein the number-average molecular weight (Mn) is in the range of 250 to 3,000. 　 The resin contains at least two compounds with different structures from the compounds represented by the following general formula (1), and R is present in the resin. １ , R ２ and R ３ At least one of them is a vinylbenzyl group, and R present in the resin １ , R ２ and R ３ The aralkyl-modified resin according to claim 1, wherein at least one of the groups is a tolymethyl group. [In general formula (1), R １ , R ２ and R ３ are each independently a hydrogen atom, a vinylbenzyl group, or a trimethylphenyl group. R ４ represents a monovalent substituent, and n is an integer of 0 or 1 to 4. When n is an integer of 2 or more, the plurality of R ４ present in the formula may all be different, or some or all may be the same.] 　 A curable resin material comprising an aralkyl-modified resin according to any one of claims 1 to 4. 　 A prepreg comprising the curable resin material described in claim 5 or a semi-cured product of the curable resin material. 　 A resin film comprising the curable resin material described in claim 5 or a semi-cured product of the curable resin material. 　 A metal-clad laminate comprising a cured product of the curable resin material described in claim 5 and a metal foil. 　 A printed circuit board comprising a cured product of the curable resin material described in claim 5. 　 A semiconductor package comprising a printed circuit board according to claim 9 and a semiconductor element. 　 A semiconductor package comprising a semiconductor element and a cured product of the curable resin material according to claim 5 for sealing the semiconductor element. 　 A printed circuit board comprising at least one of a surface protective film and an interlayer insulating film formed from the curable resin material described in claim 5.

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