Method for producing modified, hydrogenated styrene-based elastomer, modified, hydrogenated styrene-based elastomer, and resin composition

Abstract

The present disclosure relates to a method for producing a modified, hydrogenated styrene-based elastomer, the method including a step in which (a1) a hydrogenated styrene-based elastomer, (a2) a compound having a radical-reactive carbon-carbon double bond, and a radical generator are reacted at a temperature of 50°C or higher but lower than 90°C. By the method, a modified, hydrogenated styrene-based elastomer is obtained in which the compound having a carbon-carbon double bond has been grafted onto the hydrogenated styrene-based elastomer.

Description

Method for producing a modified hydrogenated styrene elastomer, modified hydrogenated styrene elastomer, and resin composition

[0001] This disclosure relates to a method for producing a modified hydrogenated styrene elastomer, the modified hydrogenated styrene elastomer, and a resin composition.

[0002] Electronic devices such as mobile communication equipment (represented by mobile phones), their base station equipment, servers, routers and other network infrastructure equipment, and large computers are increasingly using signals that are faster and have larger capacities. Consequently, printed circuit boards mounted on these electronic devices need to be able to handle high frequencies, and substrate materials with low dielectric constant and low dielectric loss tangent that can reduce transmission loss are required. In recent years, in addition to the electronic devices mentioned above, new systems that handle high-frequency wireless signals are being put into practical use and planned for practical use in the ITS (Intelligent Transport Systems) field (related to automobiles and transportation systems) and in the indoor short-range communication field. It is expected that low transmission loss substrate materials will be even more in demand for printed circuit boards mounted on these devices in the future.

[0003] To improve dielectric properties, heat resistance, and mechanical properties, it has been proposed to use a resin composition containing a styrene-based thermoplastic elastomer and a polyphenylene ether derivative having an N-substituted maleimide structure as a resin material for printed circuit boards (see, for example, Patent Document 1). Furthermore, it is known that styrene-based elastomers are acid-modified with maleic anhydride or the like to impart properties such as adhesion and affinity (see, for example, Patent Document 2).

[0004] Japanese Patent Publication No. 2019-6879 Japanese Patent Publication No. 2013-28761

[0005] This disclosure aims to provide a novel method for producing modified hydrogenated styrene elastomers. Furthermore, this disclosure aims to provide modified hydrogenated styrene elastomers and resin compositions using the same.

[0006] One aspect of the present disclosure relates to a method for producing a modified hydrogenated styrene elastomer, a modified hydrogenated styrene elastomer, and a resin composition using the same. [1] A method for producing a modified hydrogenated styrene elastomer, comprising the step of reacting (a1) a hydrogenated styrene elastomer, (a2) a compound having a radical-reactive carbon-carbon double bond, and a radical generator at a temperature of 50°C or higher and less than 90°C, wherein the compound having a carbon-carbon double bond is grafted onto the hydrogenated styrene elastomer. [2] The method according to [1], wherein the compound having a carbon-carbon double bond has one or two radical-reactive carbon-carbon double bonds. [3] The method according to [1], wherein the compound having a carbon-carbon double bond has two radical-reactive carbon-carbon double bonds. [4] A method for producing a modified hydrogenated styrene elastomer according to any one of [1] to [3] above, wherein the compound having a carbon-carbon double bond is at least one selected from the group consisting of bismaleimide compounds and di(meth)acryloyl compounds. [5] A method for producing a modified hydrogenated styrene elastomer according to any one of [1] to [4] above, wherein the graft rate of the compound having a carbon-carbon double bond is 4.5% by mass or more. [6] A modified hydrogenated styrene elastomer which is a reaction product of (a1) a hydrogenated styrene elastomer and (a2) a radical-reactive compound having a carbon-carbon double bond, wherein the side chain has a radical-reactive carbon-carbon double bond group derived from the compound having a carbon-carbon double bond, and the graft rate of the compound having a carbon-carbon double bond is 4.5% by mass or more. [7] A modified hydrogenated styrene elastomer according to [6] above, wherein the compound having a carbon-carbon double bond has one or two radical-reactive carbon-carbon double bonds. [8] The modified hydrogenated styrene elastomer according to [6], wherein the compound having a carbon-carbon double bond has two radical-reactive carbon-carbon double bonds. [9] The modified hydrogenated styrene elastomer according to any one of [6] to [8], wherein the compound having a carbon-carbon double bond is at least one selected from the group consisting of bismaleimide compounds and di(meth)acryloyl compounds.

[10] A resin composition comprising a modified hydrogenated styrene elastomer according to any one of [6] to [9] above and a thermosetting compound.

[0007] This disclosure provides a novel method for producing modified hydrogenated styrene elastomers. Furthermore, this disclosure provides modified hydrogenated styrene elastomers and resin compositions using the same.

[0008] Several embodiments of this disclosure are described in detail below. However, this disclosure is not limited to the embodiments described below. In this specification, the term “process” includes not only independent processes but also processes that are not clearly distinguishable from other processes, as long as the intended function of the process is achieved. In this specification, the term “layer” includes not only structures that are formed over the entire surface when viewed in a plan view, but also structures that are formed in part.

[0009] In this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in one stage may be replaced with the upper or lower limit of a numerical range in another stage. Also, in numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. When referring to the amount of each component in a composition in this specification, if there are multiple substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of those multiple substances present in the composition. "A or B" means that either A or B may be included, or both may be included. "Solid content" refers to the non-volatile content in a resin composition excluding volatile substances (water, solvents, etc.). That is, "solid content" refers to components other than solvents that remain without volatilizing during the drying of the resin composition described later, and includes components that are liquid, syrup-like, or waxy at room temperature (25°C). In this specification, for example, "(meth)acryloyl" means "acryloyl" and its corresponding "methacryloyl," and the same applies to other similar terms.

[0010] [Method for producing modified hydrogenated styrene elastomer] The method for producing the modified hydrogenated styrene elastomer according to this embodiment comprises the step of reacting (a1) a hydrogenated styrene elastomer (hereinafter sometimes referred to as "component (a1)"), (a2) a radical-reactive compound having a carbon-carbon double bond (hereinafter sometimes referred to as "component (a2)"), and a radical generator at a temperature of 50°C or higher and less than 90°C. In this step, a modified hydrogenated styrene elastomer is obtained in which the compound having a carbon-carbon double bond is grafted onto the hydrogenated styrene elastomer.

[0011] According to the method for producing a modified hydrogenated styrene elastomer of this embodiment, the hydrogen bonded to the tertiary carbon of the hydrogenated styrene elastomer component (a1) is abstracted by a radical generator and undergoes a radical reaction with one of the radical-reactive carbon-carbon double bonds of component (a2), thereby obtaining a modified hydrogenated styrene elastomer in which component (a2) is grafted onto component (a1).

[0012] The reaction temperature is preferably 52°C or higher, more preferably 54°C or higher, even more preferably 56°C or higher, and even more preferably 58°C or higher, from the viewpoint of improving the grafting rate of component (a2). The reaction temperature is preferably 88°C or lower, more preferably 86°C or lower, even more preferably 84°C or lower, and even more preferably 82°C or lower, from the viewpoint of suppressing gelation due to side reactions. The reaction temperature may be 52-88°C, 54-86°C, 56-84°C, or 58-82°C. The reaction time can be appropriately adjusted depending on the reaction temperature, the type of component (a2), etc. The reaction time may be 2-15 hours, 3-12 hours, 4-10 hours, or 5-9 hours.

[0013] (Component (a1): Hydrogenated styrene elastomer) Component (a1) is an elastomer in which at least a portion of the structural units constituting the styrene elastomer are hydrogenated. The styrene elastomer may be a copolymer having structural units derived from a styrene compound and structural units derived from a conjugated diene compound, and component (a1) may be an elastomer in which at least a portion of the structural units derived from the conjugated diene compound in a styrene elastomer that is a copolymer having structural units derived from a styrene compound and structural units derived from a conjugated diene compound are hydrogenated. Component (a1) may be used alone or in combination of two or more types.

[0014] Examples of styrene-based compounds include styrene, α-methylstyrene, p-methylstyrene, and p-tert-butylstyrene. Among these, styrene, α-methylstyrene, and p-methylstyrene are preferred from the viewpoint of availability and productivity, with styrene being more preferred.

[0015] Examples of conjugated diene compounds include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 1,3-pentadiene (piperylene), 1-phenyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3,4-dimethyl-1,3-hexadiene, and 4,5-diethyl-1,3-octadiene. Among these, 1,3-butadiene and isoprene are preferred from the viewpoint of availability and productivity.

[0016] (a1) Examples of components include hydrogenated styrene-butadiene-styrene block copolymers (SEBS (styrene-ethylene-butylene-styrene copolymer), SBBS (styrene-butadiene-butylene-styrene copolymer)) and hydrogenated styrene-isoprene-styrene block copolymers (SEPS).

[0017] SEBS has a hydrogenation rate of 90% or more of the carbon-carbon double bonds at the 1,2-bond sites in the butadiene block in a styrene-butadiene-styrene block copolymer, and SBBS may have a hydrogenation rate of 60-85% of the carbon-carbon double bonds at the 1,2-bond sites in the butadiene block.

[0018] In SEBS, the content of the structural unit derived from styrene (hereinafter sometimes referred to as "styrene content") may be 5-80% by mass, 5-70% by mass, 10-70% by mass, or 10-50% by mass from the viewpoints of high-frequency characteristics, adhesion to conductors, heat resistance, glass transition temperature, and thermal expansion coefficient, and may also be 10-35% by mass, or 40-70% by mass. The melt flow rate (MFR) of SEBS is not particularly limited, but may be 0.1-20 g / 10 min, or 0.5-15 g / 10 min under the measurement conditions of 230°C and a load of 2.16 kgf (21.2 N).

[0019] Examples of commercially available SEBS products include, for example, the Tuftec (registered trademark) H series and M series manufactured by Asahi Kasei Corporation, the Septon (registered trademark) series manufactured by Kuraray Co., Ltd., the Clayton (registered trademark) G polymer series manufactured by Clayton Polymer Japan Co., Ltd., and the like.

[0020] In SBBS, the styrene content may be 40-80% by mass, 50-75% by mass, or 55-75% by mass from the viewpoints of high-frequency characteristics, adhesion to conductors, heat resistance, glass transition temperature, and thermal expansion coefficient. The melt flow rate (MFR) of SBBS is not particularly limited, but may be 0.1-10 g / 10 min, 0.5-10 g / 10 min, or 1-6 g / 10 min under the measurement conditions of 190°C and a load of 2.16 kgf (21.2 N).

[0021] Examples of commercially available SBBS products include, for example, the Tuftec (registered trademark) P series manufactured by Asahi Kasei Corporation.

[0022] The hydrogenation rate of SEPS may be 90% or more, or 95% or more. In SEPS, the styrene content may be 5 to 60% by mass, 5 to 50% by mass, 10 to 40% by mass, or 15 to 35% by mass, from the viewpoint of high-frequency characteristics, adhesion to conductors, heat resistance, glass transition temperature, and coefficient of thermal expansion. The melt flow rate (MFR) of SEPS is not particularly limited, but under measurement conditions of 230°C and a load of 2.16 kgf (21.2 N), it may be 0.1 to 130 g / 10 min, 10 to 100 g / 10 min, or 50 to 90 g / 10 min.

[0023] Examples of commercially available SEPS products include the Septon® series manufactured by Kuraray Co., Ltd. and the Kraton G Polymer series manufactured by Kraton Polymer Japan Co., Ltd.

[0024] (Component (a2): Compound having a radical-reactive carbon-carbon double bond) Component (a2) is a compound having at least one radical-reactive carbon-carbon double bond. Component (a2) may be a compound having one or two radical-reactive carbon-carbon double bonds, or a compound having two radical-reactive carbon-carbon double bonds. As component (a2), compounds having radical-reactive carbon-carbon double bond groups such as vinyl groups, allyl groups, maleimide groups, and (meth)acryloyl groups can be used. From the viewpoint of improving compatibility with other components, component (a2) may be at least one selected from the group consisting of bismaleimide compounds and di(meth)acryloyl compounds.

[0025] Bismaleimide compounds are not limited to compounds having two maleimide groups. Examples of bismaleimide compounds include o-, m-, or p-bismaleimidobenzene, 1,4-bis(p-maleimidocumyl)benzene, 1,4-bis(m-maleimidocumyl)benzene, 4,4'-bismaleimidodiphenyl ether, 4,4'-bismaleimidodiphenylmethane, 4,4'-bismaleimido-3,3'-dimethyl-diphenylmethane, 4,4'-bismaleimidodiphenylsulfone, 4,4'-bismaleimidodiphenyl sulfide, 4,4'-bismaleimidodiphenyl ketone, 2,2-bis(4-maleimidophenyl)propane, 4,4'-bismaleimidodiphenylfluoromethane, 1,1,1,3,3,3-hexafluoro-2,2-bis(4-maleimidophenyl)propane, and bismaleimides represented by the following formula (1). Bismaleimide compounds may be used alone or in combination of two or more.

[0026]

[0027] In formula (1), L １ It is a divalent organic group containing a fused ring of an aromatic ring and an aliphatic ring. A fused ring of an aromatic ring and an aliphatic ring is a fused ring formed by the fusion of an aromatic ring and an aliphatic ring.

[0028] Examples of aromatic rings that form a fused ring include benzene rings, naphthalene rings, and anthracene rings. Examples of aliphatic rings that form a fused ring include cyclopentane rings and cyclohexane rings.

[0029] The aromatic ring and the aliphatic ring may each independently have substituents. Examples of substituents include hydrocarbon groups such as methyl, ethyl, propyl, and butyl groups, alkylthio groups, halogen atoms, hydroxyl groups, and mercapto groups.

[0030] The fused ring of an aromatic ring and an aliphatic ring may be an indan ring. In this specification, an indan ring means a fused bicyclic structure of an aromatic six-membered ring and a saturated aliphatic five-membered ring. The indan ring may be included in component (a2) as a divalent organic group represented by the following formula (2).

[0031] In formula (2), R １ represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group; n1 represents an integer of 0 to 3; R ２ , R ３ and R ４ each independently represent an alkyl group having 1 to 10 carbon atoms; and * represents a bonding site.

[0032] Examples of the alkyl group having 1 to 10 carbon atoms represented by R １ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, and the like. These alkyl groups may be either linear or branched-chain.

[0033] Examples of the alkyl group contained in the alkyloxy group having 1 to 10 carbon atoms and the alkylthio group having 1 to 10 carbon atoms represented by R １ are the same as those of the alkyl group having 1 to 10 carbon atoms described above.

[0034] Examples of the aryl group having 6 to 10 carbon atoms represented by R １ include a phenyl group, a naphthyl group, and the like.

[0035] Examples of the aryl group contained in the aryloxy group having 6 to 10 carbon atoms and the arylthio group having 6 to 10 carbon atoms represented by R １ are the same as those of the aryl group having 6 to 10 carbon atoms described above.

[0036] Examples of the cycloalkyl group having 3 to 10 carbon atoms represented by R １ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, and the like.

[0037] When n1 in formula (2) is an integer of 1 to 3, R １From the viewpoint of solvent solubility and reactivity, alkyl groups having 1 to 4 carbon atoms, cycloalkyl groups having 3 to 6 carbon atoms, and aryl groups having 6 to 10 carbon atoms are preferred, with alkyl groups having 1 to 4 carbon atoms being more preferred. In formula (2), n1 is an integer from 0 to 3, and when n1 is 2 or 3, multiple R １ They may be the same or they may be different.

[0038] R ２ ~R ４ Examples of C1-C10 alkyl groups represented by include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups. These alkyl groups may be linear or branched. Among these, R ２ ~R ４ The alkyl group is preferably a C1-C4 alkyl group, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0039] The bismaleimide compound may be a bismaleimide represented by the following formula (3).

[0040] R in equation (3) １ and R ６ These are R in equation (2) above. １ This is equivalent to the above equation (3) and R １ and R ６ R in formula (3) above may be the same or may be different. ２ , R ３ and R ４ These are R in equation (2) above. ２ , R ３ and R ４ This is equivalent to the above equation (3) and R ２ , R ３ and R ４ They may be the same or they may be different. ５ and R ７Each independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. Each independently represents a single bond, an alkylene group having 1 to 5 carbon atoms, or an alkylidene group having 2 to 5 carbon atoms. In formula (3) above, n1 is the same as n1 in formula (2) above, n2 to n4 each independently represent an integer from 0 to 4, and m represents a number from 0.95 to 10.0.

[0041] If n1 in equation (3) is an integer from 1 to 3, then R １ From the viewpoint of solvent solubility and reactivity, alkyl groups having 1 to 4 carbon atoms, cycloalkyl groups having 3 to 6 carbon atoms, and aryl groups having 6 to 10 carbon atoms are preferred, with alkyl groups having 1 to 4 carbon atoms being more preferred. When n1 in formula (3) above is 2 or 3, multiple R １ These may be the same or different. In equation (3) above, n2 to n4 are each an independent integer from 0 to 4. If n2 is one of 2 to 4, then multiple R ５ The same or different Rs may be identical. If n3 is any of 2 to 4, then there are multiple Rs. ６ The same or different Rs may be identical. If n4 is any of 2 to 4, then multiple Rs may be involved. ７ They may be the same or they may be different.

[0042] R ５ and R ７ As for the C1-C10 alkyl group, C1-C10 alkyloxy group, C1-C10 alkylthio group, C6-C10 aryl group, C6-C10 aryloxy group, C6-C10 arylthio group, and C3-C10 cycloalkyl group represented by R １ Examples include C1-C10 alkyl groups, C1-C10 alkyloxy groups, C1-C10 alkylthio groups, C6-C10 aryl groups, C6-C10 aryloxy groups, C6-C10 arylthio groups, and C3-C10 cycloalkyl groups.

[0043] Among these, R ５ and R ７ From the viewpoint of solvent solubility and ease of manufacture, each is preferably an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group.

[0044] In formula (3), n2 and n4 are integers from 0 to 4, and are preferably integers from 0 to 3, more preferably 0 or 2, from the viewpoint of compatibility with other resins, dielectric properties, adhesion to conductors, and ease of manufacture. When n2 and n4 are 1 or more, the benzene ring and the N-substituted maleimide group have a twisted conformation, and solvent solubility tends to be further improved by suppressing intermolecular stacking. From the viewpoint of suppressing intermolecular stacking, when n2 and n4 are 1 or more, R ５ and R ７ The substitution position is preferably the ortho position relative to the N-substituted maleimide group.

[0045] Examples of C1-C5 alkylene groups represented by X and Y include methylene groups, 1,2-dimethylene groups, 1,3-trimethylene groups, 1,4-tetramethylene groups, and 1,5-pentamethylene groups. C1-C5 alkylene groups are preferably C1-C3 alkylene groups, more preferably C1 or C2 alkylene groups, and even more preferably methylene groups.

[0046] Examples of alkylidene groups having 2 to 5 carbon atoms represented by X and Y include ethylidene, propyridene, isopropylidene, butyridene, isobutylidene, pentyridene, and isopentylidene. Among the alkylidene groups having 2 to 5 carbon atoms, alkylidene groups having 2 to 4 carbon atoms are preferred, alkylidene groups having 2 or 3 carbon atoms are more preferred, and isopropylidene groups are even more preferred.

[0047] In formula (3), m is preferably a value of 0.98 to 8.0, more preferably a value of 1.0 to 7.0, and even more preferably a value of 1.1 to 6.0, from the viewpoint of dielectric properties, adhesion to conductors, solvent solubility, handling properties, and heat resistance. m represents the average value of the number of structural units containing indan rings.

[0048] Examples of bismaleimides represented by formula (3) include the compound represented by the following formula (3A), the compound represented by the following formula (3B), the compound represented by the following formula (3C), and the compound represented by the following formula (3D). The value of m in formulas (3A), (3B), (3C), and (3D) is the same as the value of m in formula (3) above.

[0049] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the bismaleimide represented by formula (3) are not particularly limited. The Mn of the bismaleimide represented by formula (3) may be 600 to 2000, 700 to 1800, or 800 to 1400, from the viewpoint of compatibility with other components, adhesion to conductors, and heat resistance. The weight-average molecular weight (Mw) of the bismaleimide represented by formula (3) may be 1000 to 4000, 1200 to 3500, or 1800 to 3000, from the viewpoint of compatibility with other components, adhesion to conductors, and heat resistance. Mn and Mw can be measured by gel permeation chromatography (GPC) and converted using a calibration curve for standard polystyrene.

[0050] The method for producing the bismaleimide represented by formula (3) is not particularly limited. The bismaleimide represented by formula (3) can be produced, for example, by the method described in the Japan Institute of Invention and Innovation Published Technical Report No. 2020-500211. According to the production method described in the Japan Institute of Invention and Innovation Published Technical Report No. 2020-500211, a bismaleimide compound containing an indane skeleton can be obtained.

[0051] The di(meth)acryloyl compounds are not limited to compounds having two (meth)acryloyl groups. Examples of di(meth)acryloyl compounds include tricyclodecanedimethanol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, dipentaerythritol di(meth)acrylate, ethoxylated isocyanuric acid di(meth)acrylate, polyethylene glycol di(meth)acrylate, polyphenylene ether having a (meth)acryloyl group, and silsesquioxane derivatives having a (meth)acryloyl group. Di(meth)acryloyl compounds can be used alone or in combination of two or more.

[0052] From the viewpoint of excellent heat resistance, the di(meth)acryloyl compound is preferably tricyclodecanedimethanol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, polyphenylene ether having a (meth)acryloyl group, or a silsesquioxane derivative having a (meth)acryloyl group. From the viewpoint of excellent compatibility with maleimide compounds, it is more preferably tricyclodecanedimethanol di(meth)acrylate or polyphenylene ether having a (meth)acryloyl group.

[0053] From the viewpoint of increasing the graft ratio of component (a2) to component (a1), the amount of component (a2) blended may be 15 parts by mass or more, 20 parts by mass or more, 25 parts by mass or more, or 30 parts by mass or more per 100 parts by mass of component (a1). From the viewpoint of lowering the dielectric constant, the amount of component (a2) blended may be 70 parts by mass or less, 65 parts by mass or less, 60 parts by mass or less, or 55 parts by mass or less per 100 parts by mass of component (a1). The amount of component (a2) blended may be 15 to 70 parts by mass, 20 to 65 parts by mass, 25 to 60 parts by mass, or 30 to 55 parts by mass per 100 parts by mass of component (a1).

[0054] (Radical Generators) As radical generators, for example, organic peroxides and azo compounds can be used. Examples of organic peroxides include dicumyl peroxide, benzoyl peroxide, 2-butanone peroxide, tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, bis(tert-butylperoxyisopropyl)benzene, and tert-butyl hydroperoxide. Examples of azo compounds include 2,2'-azobis(2-methylpropanenitrile), 2,2'-azobis(2-methylbutanenitrile), and 1,1'-azobis(cyclohexanecarbonitride).

[0055] As a radical generator, from the viewpoint of efficiently advancing the graft reaction, an organic peroxide with a 10-hour half-life temperature of 60 to 90°C is preferred, and benzoyl peroxide with a 10-hour half-life temperature of 73.6°C or tert-butylperoxy-2-ethylhexanoate with a 10-hour half-life temperature of 72.1°C is more preferred. As a radical generator, an azo polymerization initiator such as AIBN (azobisisobutyronitrile) with a 10-hour half-life temperature of 65°C may also be used. The 10-hour half-life temperature of the radical generator may be within 20°C, 15°C, 10°C, or 5°C of the reaction temperature. A modified hydrogenated styrene elastomer, in which a compound having a carbon-carbon double bond is grafted onto a hydrogenated styrene elastomer, may be obtained by a process of reacting a hydrogenated styrene elastomer with a radical-reactive compound having a carbon-carbon double bond and a radical generator at a reaction temperature within 20°C of the 10-hour half-life temperature of the radical generator. The reaction temperature may be within 20°C, 15°C, 10°C, or 5°C of the 10-hour half-life temperature of the radical generator.

[0056] The amount of radical generator added may be 1 part by mass or more, 3 parts by mass or more, 4 parts by mass or more, or 6 parts by mass or more, per 100 parts by mass of the total of components (a1) and (a2), from the viewpoint of enhancing the hydrogen abstraction effect. The amount of radical generator added may be 15 parts by mass or less, 13 parts by mass or less, 12 parts by mass or less, or 10 parts by mass or less, from the viewpoint of maintaining the mechanical properties of the modified hydrogenated styrene elastomer. The amount of radical generator added may be 1 to 15 parts by mass, 3 to 13 parts by mass, 4 to 12 parts by mass, or 6 to 10 parts by mass, per 100 parts by mass of the total of components (a1) and (a2).

[0057] A radical generator may be added to a mixture of components (a1) and (a2) dissolved in a solvent to react component (a1) with component (a2), or a radical generator may be added to a mixture of components (a1) and (a2) dissolved in a solvent under a nitrogen atmosphere to react component (a1) with component (a2).

[0058] Examples of solvents include butyl cellosolve, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, mesitylene, methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate. These may be used individually or in combination of two or more. Among these, toluene, xylene, and propylene glycol monomethyl ether are preferred from the viewpoint of solubility.

[0059] [Modified Hydrogenated Styrene Elastomer] The modified hydrogenated styrene elastomer according to this embodiment is a reaction product of a hydrogenated styrene elastomer, which is component (a1), and a compound having a radical-reactive carbon-carbon double bond, which is component (a2), and has a radical-reactive carbon-carbon double bond group derived from component (a2) in its side chain. The grafting rate of component (a2) in the modified hydrogenated styrene elastomer is 4.5% by mass or more.

[0060] Examples of radically reactive carbon-carbon double bond groups include vinyl groups, allyl groups, maleimide groups, and (meth)acryloyl groups.

[0061] In the modified hydrogenated styrene elastomer according to this embodiment, component (a2) may be at least one selected from the group consisting of bismaleimide compounds and di(meth)acryloyl compounds. Examples of bismaleimide compounds and di(meth)acryloyl compounds include the compounds described above.

[0062] The graft ratio of component (a2) to component (a1) may be 4.5% by mass or more, 4.8% by mass or more, 5.0% by mass or more, 5.2% by mass or more, or 5.4% by mass or more, from the viewpoint of excellent compatibility with other components when preparing the resin composition, and may be 20% by mass or less, 18% by mass or less, 16% by mass or less, 14% by mass or less, or 13% by mass or less, from the viewpoint of lowering the dielectric constant. The graft ratio of component (a2) may be 4.5 to 20% by mass, 4.8 to 18% by mass, 5.0 to 16% by mass, 5.2 to 14% by mass, or 5.4 to 13% by mass. The graft ratio of component (a2) can be adjusted by changing the amount of component (a2) blended, the reaction temperature, the reaction time, etc.

[0063] (a2) The graft rate of component can be calculated by measuring the infrared absorption (IR) spectrum of the modified hydrogenated styrene elastomer using infrared spectroscopy. The graft rate in this specification is the value calculated by the method described in the examples.

[0064] [Resin Composition] A resin composition can be prepared by mixing the modified hydrogenated styrene elastomer according to this embodiment with a thermosetting compound. The resin composition according to this embodiment includes the modified hydrogenated styrene elastomer described above as component (A) and a thermosetting compound as component (B). Since component (A) according to this embodiment has excellent compatibility with component (B), a uniform resin composition can be prepared.

[0065] From the viewpoint of superior compatibility with component (A), component (B) may be a compound having a radical-reactive carbon-carbon double bond. Component (B) may be a compound having a radical-reactive carbon-carbon double bond corresponding to component (a2) described above, or it may be a thermosetting compound other than component (a2).

[0066] Examples of thermosetting compounds other than component (a2) include thermosetting resins such as epoxy resins, cyanate ester resins, acrylic resins, silicone resins, phenolic resins, maleimide resins, thermosetting polyimide resins, polyurethane resins, melamine resins, and urea resins. These can be used individually or in combination of two or more.

[0067] Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, naphthalene skeleton-containing epoxy resins such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, difunctional biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, and dihydroanthracene type epoxy resin.

[0068] The content of component (B) in the resin composition is not particularly limited. For example, the content of component (B) may be 10 parts by mass or more, 20 parts by mass or more, 30 parts by mass or more, or 40 parts by mass or more, or 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less, based on 100 parts by mass of the total amount of component (A) and component (B).

[0069] The resin composition according to this embodiment may further contain a curing accelerator, a filler, a flame retardant, and the like.

[0070] (Curing accelerators) Examples of curing accelerators include various imidazole compounds, BF3 amine complexes, and phosphorus-based curing accelerators, which are latent thermosetting agents. When curing accelerators are included, imidazole compounds and phosphorus-based curing accelerators are preferred from the viewpoint of storage stability of the resin composition, handling of the semi-cured resin composition, and solder heat resistance of the cured product.

[0071] (Fillers) Examples of fillers include silica, alumina, titanium dioxide, mica, beryllium, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, calcined clay, talc, aluminum borate, and silicon carbide. These may be used individually or in combination of two or more.

[0072] There are no particular restrictions on the shape and particle size of the filler. The particle size of the filler may be, for example, 0.01 to 20 μm or 0.1 to 10 μm. Here, particle size refers to the average particle diameter, which is the particle diameter at the point corresponding to 50% of the volume when the cumulative frequency distribution curve by particle diameter is calculated with the total volume of particles set to 100%. The average particle size can be measured using a particle size distribution analyzer that uses laser diffraction scattering or the like.

[0073] A coupling agent may be used in combination as needed to improve the dispersibility of the filler and its adhesion to organic components. The coupling agent is not particularly limited, and for example, various silane coupling agents, titanate coupling agents, etc., can be used. These may be used individually or in combination of two or more. The amount of coupling agent used is also not particularly limited, and for example, it may be 0.1 to 5 parts by mass or 0.5 to 3 parts by mass per 100 parts by mass of filler used.

[0074] When using a coupling agent, it is possible to use a so-called integral blending method in which the coupling agent is added after the filler has been blended into the resin composition. However, it is preferable to use a filler that has been pre-treated with the coupling agent by dry or wet surface treatment. By using this method, the characteristics of the filler can be expressed more effectively.

[0075] (Flame retardants) The flame retardants are not particularly limited, but brominated flame retardants, phosphorus-based flame retardants, metal hydroxides, etc., are preferably used. Examples of brominated flame retardants include brominated epoxy resins, brominated additive-type flame retardants, and brominated reaction-type flame retardants containing unsaturated double bond groups. Examples of phosphorus-based flame retardants include aromatic phosphate esters, phosphonic acid esters, phosphinic acid esters, and phosphazene compounds. Examples of metal hydroxide flame retardants include magnesium hydroxide and aluminum hydroxide.

[0076] The resin composition may be diluted with a solvent as needed. The solvent is not particularly limited, but can be determined by considering its boiling point and volatility during film formation. Examples of solvents include relatively low-boiling point solvents such as methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone, toluene, and xylene. The solvent can be used alone or in combination of two or more.

[0077] The resin composition of this embodiment can be obtained by uniformly dispersing and mixing the above-mentioned components, and the means and conditions for its preparation are not particularly limited. For example, a method can be used in which predetermined amounts of various components are thoroughly and uniformly stirred and mixed using a mixer, etc., then kneaded using a mixing roll, extruder, kneader, roll, extruder, etc., and the resulting kneaded product is further cooled and pulverized. The kneading method is also not particularly limited.

[0078] [Resin Film] A resin film can be produced using the resin composition according to this embodiment. Note that "resin film" refers to an uncured or semi-cured film-like resin composition.

[0079] The method for producing the resin film is not limited, but for example, it can be obtained by coating a resin composition onto a support substrate and drying the resulting resin layer. Specifically, the resin composition may be coated onto a support substrate using a kiss coater, roll coater, comma coater, etc., and then dried in a heating and drying oven at a temperature of, for example, 70 to 250°C, preferably 70 to 200°C, for 1 to 30 minutes, preferably 3 to 15 minutes. This will produce a resin film in which the resin composition is semi-cured.

[0080] The resin film can be further heat-cured by heating it in a heating furnace at a temperature of, for example, 170 to 250°C, preferably 185 to 230°C, for 60 to 150 minutes.

[0081] The thickness of the resin film according to this embodiment is not particularly limited, but is preferably 1 to 200 μm, more preferably 2 to 180 μm, and even more preferably 3 to 150 μm. By setting the thickness of the resin film within the above range, it is easier to achieve both thinness and good high-frequency characteristics of the printed circuit board obtained using the resin film according to this embodiment.

[0082] The support substrate is not particularly limited, but it is preferably at least one selected from the group consisting of glass, metal foil, and PET film. The presence of a support substrate in the resin film tends to improve its storability and handling when used in the manufacture of printed circuit boards. That is, the resin film according to this embodiment can take the form of a support with a resin layer comprising a resin layer containing the resin composition according to this embodiment and a support substrate, and may be peeled off from the support substrate when used.

[0083] [Prepreg] A prepreg can be prepared using the resin composition according to this embodiment. The resin composition according to this embodiment can be applied to a fibrous substrate which is a reinforcing substrate, and the applied resin composition can be dried to obtain a prepreg. Alternatively, the prepreg may be obtained by impregnating the fibrous substrate with the resin composition according to this embodiment, and then drying the impregnated resin composition. Specifically, a prepreg in which the resin composition has been partially cured can be obtained by heating and drying the fibrous substrate to which the resin composition has been applied in a drying oven at a temperature of 80 to 200°C for 1 to 30 minutes. From the viewpoint of good moldability, it is preferable that the amount of resin composition applied to the fibrous substrate is such that the resin content in the prepreg after drying is 30 to 90% by mass.

[0084] While not limited to prepreg reinforcing substrates, sheet-like fibrous substrates are preferred. Examples of sheet-like fibrous substrates include inorganic fibers such as E-glass, NE-glass, S-glass, and Q-glass; and organic fibers such as polyimide, polyester, and tetrafluoroethylene. Sheet-like fibrous substrates can be in the form of woven fabrics, non-woven fabrics, chopped strand mats, etc.

[0085] [Laminate] According to this embodiment, a laminate can be provided having a resin layer containing a cured product of the above-described resin composition and a conductive layer. For example, a metal-clad laminate can be manufactured using the above-described resin film or prepreg.

[0086] The method for manufacturing the metal-clad laminate is not limited, but for example, one or more layers of the resin film or prepreg according to this embodiment are stacked, a metal foil which will be a conductive layer is placed on at least one surface, and the material is heated and pressurized at a temperature of 170 to 250°C, preferably 185 to 230°C, and a pressure of 0.5 to 5.0 MPa for 60 to 150 minutes, thereby obtaining a metal-clad laminate having a metal foil on at least one surface of the resin layer or prepreg which will be an insulating layer. The heating and pressurizing can be carried out, for example, under conditions where the vacuum level is 10 kPa or less, preferably 5 kPa or less, and it is preferable to carry it out in a vacuum from the viewpoint of increasing efficiency. It is preferable to carry out the heating and pressurizing from 30 minutes from the start until the end of the molding process.

[0087] [Multilayer Printed Wiring Board] According to this embodiment, a multilayer printed wiring board can be provided comprising a resin layer containing a cured product of the above-described resin composition and a circuit layer. The upper limit of the number of circuit layers is not particularly limited and may range from 3 to 20 layers. The multilayer printed wiring board can also be manufactured, for example, using the above-described resin film, prepreg, or metal-clad laminate.

[0088] The method for manufacturing a multilayer printed circuit board is not particularly limited, but for example, a multilayer printed circuit board can be manufactured by first placing a resin film on one or both sides of a circuit-formed core substrate, or by placing a resin film between multiple core substrates, bonding each layer by pressurized and heated lamination molding or pressurized and heated press molding, and then performing circuit formation processing such as laser drilling, drilling, metal plating, or metal etching. If the resin film has a support substrate, the support substrate can be peeled off before placing the resin film on or between the core substrates, or peeled off after the resin layer has been attached to the core substrate.

[0089] The present disclosure will be further described with reference to the following embodiments. However, the present disclosure is not limited to these embodiments.

[0090] [Modified Hydrogenated Styrene Elastomers] (a1) Hydrogenated styrene elastomer A (unmodified SEBS, manufactured by Asahi Kasei Corporation, trade name "ToughTec H1041") and hydrogenated styrene elastomer B (maleic anhydride modified SEBS, manufactured by Asahi Kasei Corporation, trade name "ToughTec M1913") were prepared as components. (a2) Bismaleimide compound A (bismaleimide represented by the above formula (3), Mn: approximately 1000, Mw: approximately 2100), bismaleimide compound B (bismaleimide represented by the above formula (3), Mn: approximately 1200, Mw: approximately 2700), and di(meth)acryloyl compound (polyphenylene ether having a methacryloyl group, manufactured by SABIC Japan LLC, trade name "Noryl SA9000") were prepared as components. Benzoyl peroxide (Fujifilm Wako Pure Chemical Corporation) was prepared as a radical generator.

[0091] The manganese (Mn) and mineral (Mw) of bismaleimide compounds were measured by GPC. A sample of the bismaleimide compound dissolved in tetrahydrofuran (THF) to a concentration of 3% by mass was injected in 50 μL into columns heated to 30°C (one GL-R420 (Hitachi High-Tech Fielding Co., Ltd.), one GL-R430 (Hitachi High-Tech Fielding Co., Ltd.), and one GL-R440 (Hitachi High-Tech Fielding Co., Ltd.)). THF was used as the developing solvent, and measurements were performed at a flow rate of 1.6 mL / min. A UV detector (Hitachi, Ltd.) using ultraviolet light at a wavelength of 254 nm was used as the detector, and Mn and Mw were calculated from the elution time using a molecular weight / elution time curve prepared with standard polystyrene (Tosoh Corporation).

[0092] (Example 1) In a 2 L flask equipped with a condenser, nitrogen inlet tube, thermocouple, and stirrer, 453 g of xylene, 60.3 g of hydrogenated styrene elastomer A, and 21.5 g of bismaleimide compound A were added and stirred at 80°C for 0.5 hours, then the temperature was lowered to 70°C and the mixture was heated to 0.5 cm. ３ Nitrogen bubbling was carried out at a flow rate of 1 / L for 1 hour. Next, a solution of 5.25 g of benzoyl peroxide dissolved in 60.3 g of xylene was added to the flask, and the reaction was carried out at 70°C for 6 hours while nitrogen bubbling was performed. Unreacted bismaleimide compound A and by-products were extracted from the reaction solution three times with a mixed solvent of isopropyl alcohol and methyl ethyl ketone, and the mixture was concentrated. The concentrate was vacuum-dried at 70°C to obtain modified hydrogenated styrene elastomer (E1).

[0093] (Example 2) A modified hydrogenated styrene elastomer (E2) was obtained in the same manner as in Example 1, except that bismaleimide compound A was replaced with bismaleimide compound B.

[0094] (Example 3) In a 2 L flask equipped with a condenser, nitrogen inlet tube, thermocouple, and stirrer, 443 g of xylene, 59.0 g of hydrogenated styrene elastomer A, and 31.6 g of bismaleimide compound A were added, and the mixture was stirred at 80°C for 0.5 hours, then the temperature was lowered to 70°C and the mixture was heated to 0.5 cm. ３Nitrogen bubbling was carried out at a flow rate of 1 / L for 1 hour. Next, a solution of 7.70 g of benzoyl peroxide dissolved in 59.0 g of xylene was added to the flask, and the reaction was carried out at 70°C for 6 hours while nitrogen bubbling was performed. Unreacted bismaleimide compound A and by-products were extracted from the reaction solution three times with a mixed solvent of isopropyl alcohol and methyl ethyl ketone, and the mixture was concentrated. The concentrate was vacuum-dried at 70°C to obtain a modified hydrogenated styrene elastomer (E3).

[0095] (Example 4) Lower the temperature to 70°C and 0.5 cm ３ The conditions for nitrogen bubbling at a flow rate of / L for 1 hour were changed to lower the temperature to 60°C and reduce the volume to 0.5 cm. ３ A modified hydrogenated styrene elastomer (E4) was obtained in the same manner as in Example 3, except that the conditions were changed to perform nitrogen bubbling at a flow rate of / L for 1 hour, and the conditions were changed from reacting at 70°C for 6 hours while performing nitrogen bubbling to reacting at 60°C for 8 hours while performing nitrogen bubbling.

[0096] (Example 5) In a 2 L flask equipped with a condenser, nitrogen inlet tube, thermocouple, and stirrer, 451.4 g of xylene, 60.2 g of hydrogenated styrene elastomer A, and 20.5 g of di(meth)acryloyl compound were added and stirred at 80°C for 0.5 hours, then 0.5 cm ３ Nitrogen bubbling was carried out at a flow rate of 1 / L for 1 hour. Next, a solution of 7.80 g of benzoyl peroxide dissolved in 60.2 g of xylene was added to the flask, and the reaction was carried out at 80°C for 6 hours while nitrogen bubbling was performed. Unreacted di(meth)acryloyl compounds and by-products were extracted from the reaction solution three times with a mixed solvent of isopropyl alcohol and methyl ethyl ketone, and the mixture was concentrated. The concentrate was vacuum-dried at 70°C to obtain a modified hydrogenated styrene elastomer (E5).

[0097] (Comparative Example 1) The reaction was carried out in the same manner as in Example 1, except that the conditions were changed from stirring at 80°C for 0.5 hours and then lowering the temperature to 70°C to stirring at 90°C for 0.5 hours and then maintaining the temperature at 90°C, and the conditions were changed from reacting at 80°C with nitrogen bubbling for 6 hours to reacting at 90°C with nitrogen bubbling for 6 hours. The reaction solution gelled, and the modified hydrogenated styrene elastomer could not be synthesized.

[0098] (Comparative Example 2) In a 1 L flask equipped with a condenser, nitrogen inlet tube, thermocouple, and stirrer, 722 g of toluene and 150 g of hydrogenated styrene elastomer B were added, and the mixture was heated to 80°C and dissolved for 1 hour while stirring. Next, the temperature in the flask was lowered to 30°C, and a solution of 6.6 g of polyoxypropylenediamine (Huntsman, trade name "Jeffermine D230") dissolved in 6.6 g of toluene was added dropwise, and the mixture was stirred for 1 hour. After that, 2.8 g of maleic anhydride (Fujifilm Wako Pure Chemical Industries, Ltd.) was added, and the mixture was kept warm for another hour. After adding 0.53 g of p-toluenesulfonic acid, the temperature in the flask was raised to reflux temperature (approximately 110°C), and the reaction was carried out by stirring for 3 hours at 110°C while bubbling with nitrogen. Unreacted maleic anhydride was extracted three times from the reaction solution using a mixed solvent of isopropyl alcohol and methyl ethyl ketone, and the mixture was concentrated. The concentrate was vacuum-dried at 70°C to obtain a modified hydrogenated styrene elastomer (E6).

[0099] (Graft rate) The graft rate of component (a2) was calculated by measuring the IR spectra of the modified hydrogenated styrene elastomers (E1) to (E5) using an infrared spectrophotometer (Shimadzu Corporation, product name "IRSpirit").

[0100] The grafting rate of the bismaleimide compound in the modified hydrogenated styrene elastomers (E1) to (E4) is 1718 cm, derived from the carbonyl group of the maleimide group. －１ The peak intensity in the vicinity and the 1452 cm⁻¹ point originating from the methylene group of hydrogenated styrene elastomer A are significant factors. －１ The calibration curve was calculated using a pre-prepared calibration curve based on the ratio of peak intensities in the vicinity. The calibration curve was created by measuring the IR spectra of hydrogenated styrene elastomer A and bismaleimide compound, respectively, and then measuring the IR spectra of standard samples prepared by varying the mixing ratio of hydrogenated styrene elastomer A and bismaleimide compound. The results are shown in Table 1.

[0101] The grafting rate of di(meth)acryloyl compounds in the modified hydrogenated styrene elastomer (E5) is 1188 cm, which is derived from the phenyl ether group contained within the molecule of the di(meth)acryloyl compound.－１ The peak intensity in the vicinity and the 1452 cm⁻¹ point originating from the methylene group of hydrogenated styrene elastomer A are significant factors. －１ The calibration curve was calculated from the ratio of peak intensities in the vicinity. The calibration curve was created by measuring the IR spectra of hydrogenated styrene elastomer A and di(meth)acryloyl compound, and then measuring the IR spectra of standard samples prepared by varying the mixing ratio of hydrogenated styrene elastomer A and di(meth)acryloyl compound. The results are shown in Table 1.

[0102] The grafting rate of maleic anhydride in the modified hydrogenated styrene elastomer (E6) was theoretically calculated from the amount of polyoxypropylenediamine added. The results are shown in Table 2.

[0103]

[0104]

[0105] (Examples 6-10 and Comparative Example 3) [Preparation of Resin Compositions] A resin composition was prepared by mixing 50 parts by mass of each modified hydrogenated styrene elastomer with 50 parts by mass of bismaleimide compound A, which is a thermosetting compound, and 400 parts by mass of toluene.

[0106] (Compatibility) After the resin composition was left to stand at room temperature for one day, it was evaluated as follows: "A" if the resin composition remained in a single layer without turbidity, "B" if the resin composition remained in a single layer but was turbid, and "C" if the resin composition separated into two layers. The results are shown in Table 3.

[0107]

Claims

The process comprises a step of reacting (a1) a hydrogenated styrene elastomer, (a2) a compound having a radical-reactive carbon-carbon double bond, and a radical generator at a temperature of 50°C or higher and less than 90°C, A method for producing a modified hydrogenated styrene elastomer, wherein the compound having the carbon-carbon double bond is grafted onto the hydrogenated styrene elastomer. 　 The method according to claim 1, wherein the compound having a carbon-carbon double bond has one or two radical-reactive carbon-carbon double bonds. 　 The method according to claim 1, wherein the compound having a carbon-carbon double bond has two radical-reactive carbon-carbon double bonds. 　 The method according to claim 1, wherein the compound having a carbon-carbon double bond is at least one selected from the group consisting of bismaleimide compounds and di(meth)acryloyl compounds. 　 The method according to any one of claims 1 to 4, wherein the grafting rate of the compound having a carbon-carbon double bond is 4.5% by mass or more. 　 (a1) A modified hydrogenated styrene elastomer which is a reaction product of a hydrogenated styrene elastomer and (a2) a compound having a radical-reactive carbon-carbon double bond, The compound having the carbon-carbon double bond has a radical-reactive carbon-carbon double bond in its side chain, A modified hydrogenated styrene elastomer in which the grafting rate of the compound having the carbon-carbon double bond is 4.5% by mass or more. 　 The modified hydrogenated styrene elastomer according to claim 6, wherein the compound having a carbon-carbon double bond has one or two radical-reactive carbon-carbon double bonds. 　 The modified hydrogenated styrene elastomer according to claim 6, wherein the compound having a carbon-carbon double bond has two radical-reactive carbon-carbon double bonds. 　 The modified hydrogenated styrene elastomer according to claim 6, wherein the compound having a carbon-carbon double bond is at least one selected from the group consisting of bismaleimide compounds and di(meth)acryloyl compounds. 　 A resin composition comprising a modified hydrogenated styrene elastomer according to any one of claims 6 to 9 and a thermosetting compound.

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