Modified hydrogenated styrene elastomer and resin composition containing said elastomer

Abstract

A modified hydrogenated styrene elastomer according to the present disclosure is a reaction product of (a1) a hydrogenated styrene elastomer and (a2) a bismaleimide compound, wherein the modified hydrogenated styrene elastomer has a structure derived from the (a2) bismaleimide compound in a side chain, and the (a2) bismaleimide compound includes a fused ring of an aromatic ring and an aliphatic ring.

Description

Modified hydrogenated styrene-based elastomer and resin composition containing the elastomer

[0001] The present disclosure relates to a modified hydrogenated styrene-based elastomer and a resin composition containing the elastomer.

[0002] In mobile communication devices typified by mobile phones, network infrastructure devices such as their base station devices, servers, and routers, and electronic devices such as large computers, the speed and capacity of signals used are increasing year by year. Along with this, printed wiring boards mounted on these electronic devices need to support higher frequencies, and substrate materials with a low relative dielectric constant and a low dielectric tangent that enable reduction of transmission loss are required. In recent years, as applications for handling such high-frequency signals, in addition to the above-mentioned electronic devices, new systems for handling high-frequency wireless signals are also being put into practical use and practical plans are underway in the ITS field (related to automobiles and transportation systems) and the indoor short-distance communication field. In the future, it is expected that a low-transmission-loss substrate material will be further required for printed wiring boards mounted on these devices.

[0003] As a resin material for printed wiring boards, in order 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 (see, for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2019-6879

[0005] An object of the present disclosure is to provide a novel modified hydrogenated styrene-based elastomer and a resin composition containing the elastomer. In particular, an object is to provide a novel modified hydrogenated styrene-based elastomer useful for use as a resin material for printed wiring boards as described above and a resin composition containing the elastomer.

[0006] One aspect of the present disclosure provides the following modified hydrogenated styrene-based elastomer and a resin composition containing the elastomer. [1] A modified hydrogenated styrene-based elastomer which is a reaction product of (a1) a hydrogenated styrene-based elastomer and (a2) a bismaleimide compound, having a structure derived from the (a2) bismaleimide compound in a side chain, and the (a2) bismaleimide compound contains a condensed ring of an aromatic ring and an aliphatic ring, the modified hydrogenated styrene-based elastomer. [2] The modified hydrogenated styrene-based elastomer according to [1] above, wherein the condensed ring is an indane ring. [3] The modified hydrogenated styrene-based elastomer according to [2] above, wherein the indane ring is contained in the (a2) bismaleimide compound as a divalent organic group represented by the following formula (2). (In formula (2), R ４ , , ２ , ３ , １ , ６ , ３ , ４ , ２ , ５ , ７ 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, and n1 represents an integer of 0 to 3. R ２ , R ３ and R ４ each independently represents an alkyl group having 1 to 10 carbon atoms. Note that * represents a bonding site.) [4] The modified hydrogenated styrene-based elastomer according to any one of [1] to [3] above, wherein the structure derived from the (a2) bismaleimide compound is represented by the following formula (5). (In formula (5), R １ and R ６ each independently represents an alkyl group having 1 to​​​​​​​​​Each 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. n1 represents an integer from 0 to 3, n2 to n4 each independently represent an integer from 0 to 4, and m represents a number from 0.95 to 10.0. * represents a bonding site.) [5] A resin composition comprising (A) a modified hydrogenated styrene elastomer described in any of [1] to [4] above, and (B) a bismaleimide compound.

[0007] This disclosure provides novel modified hydrogenated styrene elastomers and resin compositions containing the elastomer. In particular, it provides novel modified hydrogenated styrene elastomers and resin compositions containing the elastomer that are useful for use in resin materials for printed circuit boards as described above.

[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).

[0010] [Modified Hydrogenated Styrene Elastomer] The modified hydrogenated styrene elastomer according to this embodiment is a modified hydrogenated styrene elastomer which is a reaction product of (a1) a hydrogenated styrene elastomer (hereinafter sometimes referred to as "component (a1)") and (a2) a bismaleimide compound (hereinafter sometimes referred to as "component (a2)"), and has a structure in its side chain derived from the (a2) bismaleimide compound, wherein the (a2) bismaleimide compound contains a fused ring of an aromatic ring and an aliphatic ring. Such a modified hydrogenated styrene elastomer is useful as a resin material used in applications such as printed circuit boards.

[0011] (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.

[0012] Examples of styrene-based compounds include styrene, α-methylstyrene, p-methylstyrene, and p-tert-butylstyrene. Among these, styrene, α-methylstyrene, and 4-methylstyrene are preferred from the viewpoint of availability and productivity, with styrene being more preferred.

[0013] 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.

[0014] (a1) Component may be a hydrogenated styrene elastomer having a structural unit derived from a styrene compound represented by the following formula (S-1).

[0015] In the above formula (S-1), R ａ R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ｂ * represents an alkyl group with 1 to 5 carbon atoms. k is an integer from 0 to 5. * represents a bonding site.

[0016] R ａ and R ｂThe alkyl group having 1 to 5 carbon atoms represented by can be, independently, a methyl group, an ethyl group, an n-propyl group, etc., and may also be an alkyl group having 1 to 3 carbon atoms, or a methyl group. k may be an integer from 0 to 2, or it may be 0 or 1, or it may be 0. ａ The alkyl group with 1 to 5 carbon atoms represented by R ｂ The alkyl group having 1 to 5 carbon atoms represented by may be the same or different.

[0017] (a1) Component may have structural units other than structural units derived from styrene compounds. Examples of structural units other than those derived from styrene compounds that component (a1) may have include structural units derived from butadiene, structural units derived from isoprene, structural units derived from maleic acid, structural units derived from maleic anhydride, etc. Structural units derived from butadiene and structural units derived from isoprene may be hydrogenated. When hydrogenated, structural units derived from butadiene become structural units that are a mixture of ethylene units and butylene units, and structural units derived from isoprene become structural units that are a mixture of ethylene units and propylene units.

[0018] (a1) Component (a1) may be at least one selected from 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) from the viewpoint of high-frequency characteristics, adhesion to conductors, heat resistance, glass transition temperature and coefficient of thermal expansion.

[0019] Examples of hydrogenated styrene-butadiene-styrene block copolymers include SEBS, in which the hydrogenation rate of the carbon-carbon double bonds at the 1,2-bonding sites (see formula (S-2) below) and the 2,3-bonding sites (see formula (S-3) below) in the butadiene block is 90% or more based on the total carbon-carbon double bonds, and SBBS, in which the hydrogenation rate of the carbon-carbon double bonds at the 1,2-bonding sites (see formula (S-2) below) and the 2,3-bonding sites (see formula (S-3) below) in the butadiene block is 60-85% based on the total carbon-carbon double bonds.

[0020] Styrene elastomers with a relatively low hydrogenation rate (in which many carbon-carbon double bonds remain), such as SBBS, are also referred to as "partially hydrogenated styrene elastomers" in this specification. Component (a1) may be such a partially hydrogenated styrene elastomer.

[0021] In SEBS, the content of styrene-derived structural units (hereinafter sometimes referred to as "styrene content") may be 5 to 80% by mass, 5 to 70% by mass, 10 to 70% by mass, or 10 to 50% by mass, or 10 to 35% by mass, or 40 to 70% 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 SEBS 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 20 g / 10 min or 0.5 to 15 g / 10 min.

[0022] Examples of commercially available SEBS products include the ToughTec® H series and M series manufactured by Asahi Kasei Corporation, the Septon® series manufactured by Kuraray Co., Ltd., and the Kraton® G polymer series manufactured by Kraton Polymer Japan Co., Ltd.

[0023] In SBBS, the styrene content may be 40-80% by mass, 50-75% by mass, or 55-75% 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 SBBS is not particularly limited, but under measurement conditions of 190°C and a load of 2.16 kgf (21.2 N), it may be 0.1-10 g / 10 min, 0.5-10 g / 10 min, or 1-6 g / 10 min.

[0024] Examples of commercially available SBBS products include the ToughTec® P series manufactured by Asahi Kasei Corporation.

[0025] The hydrogenation rate of the hydrogenated styrene-isoprene-styrene block copolymer (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.

[0026] 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.

[0027] (Component (a2): Bismaleimide compound) Component (a2) includes 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. The bismaleimide compound according to this embodiment is represented by the following formula (1).

[0028] In the above formula (1), L １ It is a divalent organic group containing a fused ring of an aromatic ring and an aliphatic ring.

[0029] 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.

[0030] The aromatic ring and the aliphatic ring may each independently have substituents. Examples of substituents include hydroxyl groups; hydrocarbon groups such as methyl, ethyl, propyl, and butyl groups; halogen atoms; mercapto groups; and alkylthio groups.

[0031] 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).

[0032] In the above formula (2), R １ R 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, and n1 represents an integer from 0 to 3. ２ , R ３ and R ４ Each of these independently represents an alkyl group having 1 to 10 carbon atoms. * represents a bonding site.

[0033] R １ 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.

[0034] R １ Examples of alkyl groups included in the C1-C10 alkyloxy group and C1-C10 alkylthio group represented by the above include the same C1-C10 alkyl groups.

[0035] R １Examples of aryl groups having 6 to 10 carbon atoms, represented by this formula, include phenyl groups and naphthyl groups.

[0036] R １ Examples of aryl groups included in the aryloxy group and arylthio group having 6 to 10 carbon atoms represented by the formula are the same as the aryl group having 6 to 10 carbon atoms described above.

[0037] R １ Examples of cycloalkyl groups having 3 to 10 carbon atoms represented by the formula include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, and cyclodecyl group.

[0038] If n1 in equation (2) above 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. In formula (2) above, n1 is an integer from 0 to 3, and when n1 is 2 or 3, there are multiple R １ They may be the same or they may be different.

[0039] 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.

[0040] (a2) Component may be a compound represented by the following formula (3).

[0041] In the above formula (3), R １ and R ６ These are R in equation (2) above. １ This is equivalent to the above equation (3), and R１ 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 ７ Each 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.

[0042] If n1 in the above 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.

[0043] R ５ and R ７As 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.

[0044] 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.

[0045] In formula (3) above, 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.

[0046] 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.

[0047] 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.

[0048] In formula (3) above, 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. Note that m represents the average value of the number of structural units containing indan rings.

[0049] Examples of the (a2) component represented by formula (3) above include the compound represented by formula (3A) below, the compound represented by formula (3B) below, the compound represented by formula (3C) below, and the compound represented by formula (3D) below. The m in formulas (3A), (3B), (3C), and (3D) are the same as the m in formula (3) above.

[0050] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of component (a2) represented by formula (3) are not particularly limited. From the viewpoint of compatibility with other components, adhesion to conductors, and heat resistance, the Mn of component (a2) 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 component (a2) represented by formula (3) may be 1000 to 4000, 1200 to 3500, or 1800 to 3000. Mn and Mw can be measured by gel permeation chromatography (GPC) and converted using a calibration curve for standard polystyrene.

[0051] The method for producing component (a2) represented by formula (3) above is not particularly limited. Component (a2) represented by formula (3) above 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.

[0052] The modified hydrogenated styrene elastomer according to this embodiment has a side chain structure derived from component (a2) by grafting a carbon-carbon double bond portion contained in one of the maleimide structures in component (a2) onto component (a1). The structure derived from component (a2) is represented by the following formula (4).

[0053] In the above formula (4), L ２ This is a divalent organic group containing a fused ring of an aromatic ring and an aliphatic ring. * indicates a bonding site. ２ Examples of divalent organic groups represented by the above formula (2) include organic groups containing the structure represented by the above formula (2).

[0054] The structure derived from component (a2) of the modified hydrogenated styrene elastomer according to this embodiment may be represented by the following formula (5).

[0055] In the above formula (5), R １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７ n1, n2, n3, n4, m, X and Y are R in formula (3) above. １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７ These are synonymous with n1, n2, n3, n4, m, X, and Y. * indicates a bonding site.

[0056] If n1 in equation (5) above is an integer from 1 to 3, then 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. When n1 in formula (5) above is 2 or 3, multiple R １ These elements may be the same or different. In equation (5) above, n2 to n4 are each independent integers 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.

[0057] In formula (5) above, 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.

[0058] 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.

[0059] The graft ratio of component (a2) relative to component (a1) can be measured by spectroscopy. The graft ratio can be measured by spectroscopy using the following procedure, for example: First, an infrared spectrophotometer is used to measure the specific wavenumber (e.g., 1452 cm) of component (a1) before the reaction. －１ The peak intensity (A1) of the modified hydrogenated styrene elastomer obtained by reacting component (a1) and component (a2) is measured. Then, the peak intensity (A1) of the modified hydrogenated styrene elastomer is measured at a specific wavenumber (e.g., 1718 cm⁻¹). －１ Measure the peak intensity (A2) of ). From the measured peak intensities A1 and A2, calculate the ratio (R) using the following formula: Ratio (R) = A2 / A1

[0060] Next, the graft rate (mass%) is calculated from this ratio (R) using a pre-prepared calibration curve. This calibration curve is created by varying the input weight ratio of the mixture of component (a1) and component (a2), performing infrared spectrophotometer measurements, and measuring the ratio (R) of the peak intensities of each sample. This calibration curve establishes the relationship between the ratio (R) of peak intensities and the graft rate (mass%). This allows the graft rate (mass%) to be determined.

[0061] The modified hydrogenated styrene elastomer according to this embodiment can be produced by reacting component (a1) and component (a2). The method of reacting component (a1) and component (a2) is not particularly limited. For example, the modified hydrogenated styrene elastomer can be produced by charging component (a1), component (a2), a reaction catalyst, and an organic solvent into a reaction vessel and reacting them while heating, maintaining temperature, stirring, etc., as necessary.

[0062] The reaction catalyst may be added to a mixture of components (a1) and (a2) dissolved in a solvent to react component (a1) with component (a2), or the reaction catalyst 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).

[0063] The reaction temperature for the above reaction is preferably 50 to 115°C, more preferably 55 to 95°C, 50°C or higher and less than 90°C, and even more preferably 55 to 80°C, from the viewpoint of workability and suppression of product gelation during the reaction. The reaction time for the above reaction is preferably 1.5 to 15 hours, more preferably 3 to 12 hours, and even more preferably 5 to 9 hours, from the viewpoint of productivity and allowing the reaction to proceed sufficiently. These reaction conditions can be appropriately adjusted depending on the type of raw materials used, etc., and are not particularly limited.

[0064] Examples of organic solvents used in the above reaction include alcoholic solvents such as methanol, ethanol, butanol, butyl cellosolve, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbon solvents such as toluene, xylene, and mesitylene; ester solvents such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate; and nitrogen atom-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The organic solvent may be used individually or in combination of two or more. Among these, toluene or xylene is preferred from the viewpoint of resin solubility.

[0065] When the above reaction is carried out in an organic solvent, the total content of component (a1) and component (a2) in the reaction solution is not particularly limited, but is preferably 10 to 70% by mass, more preferably 15 to 60% by mass, and even more preferably 20 to 50% by mass. When the total content of component (a1) and component (a2) is above the lower limit, a good reaction rate is obtained and productivity tends to be better. Also, when the total content of component (a1) and component (a2) is below the upper limit, better solubility is obtained, stirring efficiency is improved, and gelation of the product during the reaction tends to be further suppressed.

[0066] Organic peroxides are preferred as reaction catalysts because they suppress product gelation during the reaction while providing sufficient reactivity. Examples of organic peroxides include benzoyl peroxide and α,α'-bis(t-butylperoxy)diisopropylbenzene. The reaction catalyst may be used alone or in combination of two or more types.

[0067] The amount of reaction catalyst used is not particularly limited, but from the viewpoint of reaction rate and reaction uniformity, it is preferably 1 to 12 parts by mass, more preferably 2 to 11 parts by mass, even more preferably 3 to 11 parts by mass, and even more preferably 5 to 10 parts by mass, based on 100 parts by mass of the total amount of component (a1) and component (a2).

[0068] When a modified hydrogenated styrene elastomer with a low hydrogenation rate is obtained using a partially hydrogenated styrene elastomer as component (a1), a large number of unsaturated bonds remain in the modified hydrogenated styrene elastomer, making it easy for the product to gel during the reaction. In this case, it is preferable to set the amount of radicals generated during the reaction low in order to suppress the gelation of the product during the reaction. Methods for setting the amount of radicals generated low include adjusting the reaction temperature and adjusting the amount of reaction catalyst used. From the viewpoint of suppressing the gelation of the product, the amount of reaction catalyst used when obtaining a modified hydrogenated styrene elastomer with a low hydrogenation rate is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the total amount of components (a1) and (a2). The amount of reaction catalyst used may also be 1 part by mass or more, or 2 parts by mass or more, per 100 parts by mass of the total amount of components (a1) and (a2).

[0069] The successful production of a modified hydrogenated styrene elastomer can be determined by infrared spectrophotometric measurement. For example, by measuring the infrared spectrophotometric value of the modified hydrogenated styrene elastomer, a value of 1718 cm² is obtained, which originates from the carbonyl group in the maleimide group of component (a2). －１ The nearby peak and the 1452 cm⁻¹ point originating from the methylene group of component (a1) －１ This can be confirmed by the presence of nearby peaks.

[0070] [Resin Composition] The resin composition according to this embodiment comprises (A) the modified hydrogenated styrene elastomer described above (hereinafter sometimes referred to as "component (A)") and (B) a bismaleimide compound (hereinafter sometimes referred to as "component (B)"). The resin composition according to this embodiment tends to have excellent compatibility between component (A) and component (B).

[0071] Component (B) can be, for example, a bismaleimide compound similar to the bismaleimide compound listed as component (a2). From the viewpoint of superior compatibility between component (A) and component (B), component (B) may be the same bismaleimide compound as component (a2).

[0072] In the resin composition of this embodiment, the content of component (A) is not particularly limited, but is preferably 10 to 90 parts by mass, more preferably 20 to 80 parts by mass, and even more preferably 25 to 75 parts by mass, based on 100 parts by mass of the total amount of resin components in the resin composition of this embodiment. When the content of component (A) is above the lower limit, the heat resistance, moldability, processability, flame retardancy, and adhesion to conductors tend to be better. Also, when the content of component (A) is below the upper limit, the dielectric properties tend to be better.

[0073] (A) The content of component (A) may be 30 parts by mass or more, 40 parts by mass or more, or 50 parts by mass or more, based on 100 parts by mass of the total amount of resin components in the resin composition of this embodiment, from the viewpoint of further improving heat resistance and the like.

[0074] (A) The content of component (A) may be 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less, based on 100 parts by mass of the total amount of resin components in the resin composition of this embodiment.

[0075] Herein, in this specification, "resin component" means resin and compounds that form a resin cured product through a curing reaction, for example, components (A) and (B) correspond to the resin component. Furthermore, if the resin composition of this embodiment contains, as optional components, resin or compounds that form a resin cured product through a curing reaction in addition to components (A) and (B), these optional components are also included in the resin component. Thermosetting resins described later are included in the resin component, while curing accelerators, fillers, and flame retardants described later are not included in the resin component.

[0076] In the resin composition of this embodiment, the content of component (B) is not particularly limited, but is preferably 10 to 90 parts by mass, more preferably 20 to 80 parts by mass, and even more preferably 25 to 75 parts by mass, based on 100 parts by mass of the total amount of resin components in the resin composition of this embodiment. When the content of component (B) is above the lower limit, the dielectric properties tend to be better. Also, when the content of component (B) is below the upper limit, the heat resistance, moldability, processability, flame retardancy, and adhesion to conductors tend to be better.

[0077] (B) The content of component (B) may be 30 parts by mass or more, 40 parts by mass or more, or 50 parts by mass or more, based on 100 parts by mass of the total amount of resin components in the resin composition of this embodiment, from the viewpoint of further improving dielectric properties, etc.

[0078] (B) The content of component (B) may be 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, or 40 parts by mass or less, based on 100 parts by mass of the total amount of resin components in the resin composition of this embodiment.

[0079] In the resin composition of this embodiment, the content of component (A) and component (B) (component (A) / component (B)) is not particularly limited, but is preferably 0.1 to 9, more preferably 0.25 to 4, and even more preferably 0.3 to 3 by mass. When the content ratio of component (A) to component (B) is above the lower limit, the heat resistance, moldability, processability, flame retardancy, and adhesion to conductors tend to be better. Also, when the content ratio of component (A) to component (B) is below the upper limit, the dielectric properties tend to be better.

[0080] From the viewpoint of further improving heat resistance, etc., the content ratio of component (A) to component (B) may be 0.5 or more, 1 or more, or 1.5 or more by mass.

[0081] From the viewpoint of further improving dielectric properties, the content ratio of the modified hydrogenated styrene elastomer to component (B) may be 7 or less, 2 or less, 1 or less, or 0.6 or less by mass.

[0082] The content of the resin component in the resin composition of this embodiment is not particularly limited, but from the viewpoint of low thermal expansion, elastic modulus, heat resistance, flame retardancy, and adhesion to conductors, it is preferably 10 to 70% by mass, more preferably 20 to 65% by mass, and even more preferably 30 to 60% by mass.

[0083] The resin composition according to this embodiment may contain other components besides components (A) and (B). Examples of other components include thermosetting resins, curing accelerators, fillers, and flame retardants.

[0084] (Thermosetting resins) Examples of thermosetting resins include epoxy resins, cyanate ester resins, acrylic resins, silicone resins, phenolic resins, thermosetting polyimide resins, polyurethane resins, melamine resins, and urea resins. These can be used individually or in combination of two or more.

[0085] 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.

[0086] (Curing accelerator) Examples of curing accelerators include various imidazole compounds, which are latent thermosetting agents, and BF ３ Examples include amine complexes and phosphorus-based curing accelerators. When a curing accelerator is 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.

[0087] (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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] (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.

[0092] 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.

[0093] 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.

[0094] [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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] [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.

[0100] 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.

[0101] [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.

[0102] 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.

[0103] [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.

[0104] 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.

[0105] While preferred embodiments of the present disclosure have been described above, these are merely illustrative examples for the purpose of explaining the disclosure and are not intended to limit the scope of the present invention to these embodiments only. The present invention can be implemented in various forms different from those described above without departing from its spirit.

[0106] The present disclosure will be described more specifically with reference to the following examples. However, the present disclosure is not limited to these examples.

[0107] The following materials were prepared. <(a1) component: hydrogenated styrene-based elastomer> - Hydrogenated styrene-based elastomer A (unmodified SEBS, manufactured by Asahi Kasei Corporation, trade name "Tuftec H1041") - Partially hydrogenated styrene-based elastomer B (unmodified SBBS, manufactured by Asahi Kasei Corporation, trade name "Tuftec B1500") - Hydrogenated styrene-based elastomer C (maleic anhydride-modified SEBS, manufactured by Asahi Kasei Corporation, trade name "Tuftec M1913")<(a2) component: bismaleimide compound>- Bismaleimide compound A (the bismaleimide compound represented by the above formula (3), number average molecular weight (Mn): about 1000, weight average molecular weight (Mw): about 2100) - Bismaleimide compound B (the bismaleimide compound represented by the above formula (3), number average molecular weight (Mn): about 1200, weight average molecular weight (Mw): about 2700)

[0108] The Mn and Mw of the bismaleimide compound were measured by GPC. A sample prepared by dissolving the bismaleimide compound in tetrahydrofuran (THF) to a concentration of 3% by mass was injected into columns (one GL-R420 (manufactured by Hitachi High-Tech Fielding Co., Ltd.), one GL-R430 (manufactured by Hitachi High-Tech Fielding Co., Ltd.), and one GL-R440 (manufactured by Hitachi High-Tech Fielding Co., Ltd.)) heated to 30°C at 50 μL, and measurement was performed under the conditions of using THF as the developing solvent and a flow rate of 1.6 mL / min. An UV detector (manufactured by Hitachi, Ltd.) using ultraviolet light with a wavelength of 254 nm was used as the detector, and Mn and Mw were converted from the elution time using a molecular weight / elution time curve prepared using standard polystyrene (manufactured by Tosoh Corporation).

[0109] (Example 1) 453 g of xylene, 60.3 g of hydrogenated styrene-based elastomer A, and 21.5 g of bismaleimide compound A were charged into a 2 L flask equipped with a cooling tube, a nitrogen introduction tube, a thermocouple, and a stirrer, and stirred at 80°C for 0.5 hours, then cooled to 70°C, and 0.5 cm ３Nitrogen bubbling was carried out at a flow rate of 1 / L for 1.0 hour. Next, 5.25 g of benzoyl peroxide (Fujifilm Wako Pure Chemical Corporation) was dissolved in 60.3 g of xylene, and the prepared benzoyl peroxide xylene solution was added to the flask. The mixture was stirred at 70°C with nitrogen bubbling for 6.0 hours to carry out the reaction and obtain a xylene solution of the modified hydrogenated styrene elastomer (E1). Unreacted bismaleimide compound A and by-products were extracted from the obtained solution three times with a mixed solvent of isopropyl alcohol and methyl ethyl ketone, and the solution was concentrated. The concentrate was vacuum dried at 70°C to obtain the modified hydrogenated styrene elastomer (E1).

[0110] (Example 2) A modified hydrogenated styrene elastomer (E2) was obtained in the same manner as in Example 1, except that bismaleimide compound B was used instead of bismaleimide compound A.

[0111] (Example 3) Modified hydrogenated styrene elastomer (E3) was obtained in the same manner as in Example 1, except that the amount of each component used was changed as shown in Table 1.

[0112] (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 1.0 hour were changed to lower the temperature to 60°C and reduce the flow rate 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 1.0 hour, and the conditions were changed from reacting at 70°C with nitrogen bubbling for 6.0 hours to reacting at 60°C with nitrogen bubbling for 8.0 hours.

[0113] (Example 5) In a 2 L flask equipped with a condenser, nitrogen inlet tube, thermocouple, and stirrer, 446 g of xylene, 59.5 g of partially hydrogenated styrene elastomer B, and 32.6 g of bismaleimide compound A were added and stirred at 70°C for 0.5 hours, then 0.5 cm ３Nitrogen bubbling was carried out at a flow rate of 1 / L for 1.0 hour. Next, 1.93 g of benzoyl peroxide (Fujifilm Wako Pure Chemical Corporation) was dissolved in 59.5 g of xylene, and the prepared benzoyl peroxide xylene solution was added to the flask. The mixture was stirred at 70°C with nitrogen bubbling for 6.0 hours to carry out the reaction and obtain a xylene solution of the modified partially hydrogenated styrene elastomer (E5). Unreacted bismaleimide compound A and by-products were extracted three times from the obtained solution with a mixed solvent of isopropyl alcohol and methyl ethyl ketone, and the solution was concentrated. The concentrate was vacuum-dried at 70°C to obtain the modified hydrogenated styrene elastomer (E5).

[0114] (Comparative Example 1) 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 C were added, and the temperature was raised to 80°C. The mixture was dissolved for 1.0 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 1.0 hour. After that, 2.8 g of maleic anhydride was added, and the mixture was kept warm for another 1.0 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 3.0 hours at 110°C while bubbling with nitrogen to obtain a toluene solution of modified hydrogenated styrene elastomer (E6), in which a bismaleimide compound that does not contain a condensed ring of an aromatic ring and an aliphatic ring was grafted onto hydrogenated styrene elastomer C. Unreacted maleic anhydride and by-products were extracted three times from the obtained solution with a mixed solvent of isopropyl alcohol and methyl ethyl ketone, and the solution was concentrated. The concentrate was vacuum-dried at 70°C to obtain modified hydrogenated styrene elastomer (E6).

[0115] The obtained elastomers (E1) to (E5) were confirmed by infrared spectrophotometric spectroscopy to be modified hydrogenated styrene elastomers having the structure represented by formula (5) above.

[0116] [Measurement of Graft Rate] The graft rate of the bismaleimide compound was calculated by measuring the IR spectra of elastomers (E1) to (E5) using an infrared spectrophotometer (Shimadzu Corporation, product name "IRSpirit").

[0117] The grafting rate of the bismaleimide compound in elastomers (E1) to (E5) 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 groups of hydrogenated styrene elastomer A and partially hydrogenated styrene elastomer B are also relevant. －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 elastomers, partially hydrogenated styrene elastomers, and bismaleimide compounds, respectively, and then measuring the IR spectra of standard samples prepared by varying the mixing ratio of hydrogenated styrene elastomers and bismaleimide compounds, and the mixing ratio of partially hydrogenated styrene elastomers and bismaleimide compounds. The results are shown in Table 1.

[0118] The graft rate of bismaleimide compounds that do not contain fused rings between aromatic and aliphatic rings in elastomer (E6) was theoretically calculated from the amount of polyoxypropylenediamine added. The results are shown in Table 1.

[0119]

[0120] (Examples 6-10 and Comparative Example 2) <Preparation of Resin Compositions> A resin composition was prepared by mixing 50 parts by mass of each elastomer with 50 parts by mass of bismaleimide compound A and 400 parts by mass of toluene.

[0121] [Compatibility Evaluation] After leaving the resin composition at room temperature for one day, it was evaluated as "A" if the resin composition remained in a single layer state, and as "B" if the resin composition separated into two layers. The results are shown in Table 2.

[0122]

Claims

1. A modified hydrogenated styrene elastomer obtained as a reaction product of (a1) a hydrogenated styrene elastomer and (a2) a bismaleimide compound, wherein the side chain has a structure derived from the (a2) bismaleimide compound, and the (a2) bismaleimide compound contains a fused ring of an aromatic ring and an aliphatic ring.

2. The modified hydrogenated styrene elastomer according to claim 1, wherein the condensed ring is an indan ring.

3. The modified hydrogenated styrene elastomer according to claim 2, wherein the indan ring is included in the (a2) bismaleimide compound as a divalent organic group represented by the following formula (2). (In formula (2), R １ R 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, and n1 represents an integer from 0 to 3. ２ , R ３ and R ４ Each of these independently represents an alkyl group having 1 to 10 carbon atoms. (Note that * represents a bonding site.) 4. The modified hydrogenated styrene-based elastomer according to claim 1, wherein the structure derived from the (a2) bismaleimide compound is represented by the following formula (5). (In formula (5), R １ and R ６ each 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 hydroxyl group or a mercapto group. R ２ , R ３ and R ４ each independently represents an alkyl group having 1 to 10 carbon atoms. R ５ and R<00​ 5. A resin composition comprising (A) a modified hydrogenated styrene elastomer according to any one of claims 1 to 4, and (B) a bismaleimide compound.

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