Resin composition, prepreg, laminate, resin film, printed circuit board, semiconductor package, method for manufacturing resin composition and resin

Abstract

To provide a resin composition having excellent dielectric properties and low thermal expansion properties, a prepreg, a laminate, a resin film, a printed wiring board and a semiconductor package using the resin composition, a method for producing the resin composition and a resin.SOLUTION: There are provided: a resin composition comprising (A) a resin containing a structural unit derived from a maleimide resin having one or more N-substituted maleimide groups and a structural unit derived from an aromatic vinyl compound and (B) a thermoplastic resin; a prepreg, a laminate, a resin film, a printed wiring board and a semiconductor package using the resin composition; a method for producing the resin composition; and a resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This embodiment relates to resin compositions, prepregs, laminates, resin films, printed circuit boards, semiconductor packages, methods for manufacturing resin compositions, and resins. [Background technology]

[0002] In mobile communication devices such as mobile phones, their base station equipment, network infrastructure equipment such as servers and routers, and electronic devices such as large computers, the speed and capacity of the signals used are increasing year by year. Accordingly, the substrate materials of printed circuit boards mounted on these electronic devices are required to have dielectric properties that can reduce the transmission loss of high-frequency signals [hereinafter sometimes referred to as "high-frequency properties"], that is, low relative permittivity and low dielectric loss tangent. In recent years, in addition to the electronic devices mentioned above, new systems handling high-frequency wireless signals are being put into practical use or are planned for practical use in fields such as Intelligent Transport Systems (ITS) related to automobiles and transportation systems, as well as in the field of short-range indoor communications. Therefore, it is expected that the need for substrate materials with excellent high-frequency characteristics will increase for printed circuit boards used in these fields in the future.

[0003] Printed circuit boards (PCBs) are required to have heat resistance and low thermal expansion to withstand their operating environment. Therefore, resins with excellent mechanical properties, such as maleimide resin, have been used in PCBs. However, many of these resins with excellent mechanical properties contain polar groups, leaving room for improvement in high-frequency characteristics. Therefore, for printed circuit boards requiring extremely low transmission loss, resins that contribute to low dielectric loss tangent, such as polyphenylene ether, polybutadiene, and styrene-ethylene-butylene-styrene block copolymer (SEBS), have been used (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-077786 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, it was difficult to achieve further improvements in dielectric properties and low thermal expansion using only these resins.

[0006] In view of the current situation, this embodiment aims to provide a resin composition with excellent dielectric properties and low thermal expansion, a prepreg, laminate, resin film, printed circuit board, and semiconductor package using the resin composition, a method for manufacturing the resin composition, and a resin. [Means for solving the problem]

[0007] As a result of further investigations to solve the above problems, the present inventors found that the following embodiments [1] to

[15] can solve the problems. [1](A)A resin comprising a structural unit derived from a maleimide resin having one or more N-substituted maleimide groups and a structural unit derived from an aromatic vinyl compound, (B) Thermoplastic resin and A resin composition containing [the specified ingredient]. [2] The resin composition according to [1] above, wherein the aromatic vinyl compound is an α-methylstyrene dimer. [3] The resin composition according to [1] or [2] above, wherein the (B) thermoplastic resin contains (B1) polyphenylene ether resin. [4] The resin composition according to any one of [1] to [3] above, wherein the (B) thermoplastic resin contains (B2) styrene elastomer. [5] The resin composition according to any one of [1] to [4] above, further comprising (C) a crosslinking agent having two or more ethylenically unsaturated bonds. [6] A prepreg containing the resin composition described in any of [1] to [5] above or a semi-cured product of the resin composition. [7] A laminate having a cured resin composition according to any of [1] to [5] above or a cured prepreg according to [6], and a metal foil. [8] A resin film containing the resin composition described in any of [1] to [5] above or a semi-cured product of the resin composition. [9] A printed circuit board having one or more selected from the group consisting of a cured resin composition described in any of [1] to [5] above, a cured prepreg described in [6] above, and a laminate described in [7] above.

[10] A semiconductor package having the printed circuit board described in [9] above and a semiconductor element.

[11] A method for producing a resin composition comprising a maleimide resin having one or more N-substituted maleimide groups, an aromatic vinyl compound, and a thermoplastic resin.

[12] A method for producing the resin composition according to

[11] , comprising blending and reacting a maleimide resin having one or more N-substituted maleimide groups with the aromatic vinyl compound, and the thermoplastic resin.

[13] A method for producing the resin composition according to

[12] , wherein the aromatic vinyl compound is an α-methylstyrene dimer.

[14] A resin comprising structural units derived from a maleimide resin having one or more N-substituted maleimide groups, and structural units derived from an aromatic vinyl compound.

[15] The resin according to

[14] above, wherein the aromatic vinyl compound is an α-methylstyrene dimer. [Effects of the Invention]

[0008] According to this embodiment, it is possible to provide a resin composition with excellent dielectric properties and low thermal expansion, a prepreg, laminate, resin film, printed circuit board, and semiconductor package using the resin composition, a method for manufacturing the resin composition, and a resin. [Modes for carrying out the invention]

[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. For example, the notation "X~Y" (where X and Y are real numbers) means a range of numbers that are greater than or equal to X and less than or equal to Y. In this specification, the phrase "greater than or equal to X" means X and numbers greater than X. In this specification, the phrase "less than or equal to Y" means Y and numbers less than Y. The lower and upper limits of the numerical ranges described herein may be arbitrarily combined with the lower or upper limits of other numerical ranges. In the numerical ranges described herein, the lower or upper limits of those ranges may be replaced with the values ​​shown in the examples.

[0010] Unless otherwise specified, each component and material exemplified herein may be used alone or in combination of two or more. In this specification, the content of each component in a resin composition means the total amount of multiple substances present in the resin composition, unless otherwise specified, if multiple substances corresponding to each component are present in the resin composition.

[0011] In this specification, "solids" refers to the non-volatile components excluding volatile substances such as solvents. That is, "solids" are the components that remain without volatilization when the resin composition is dried, and include liquid, syrup-like, and wax-like substances at room temperature. Here, room temperature in this specification means 25°C.

[0012] In this specification, "(meth)acrylate" means "acrylate" and its corresponding "methacrylate." Similarly, "(meth)acrylic" means "acrylic" and its corresponding "methacrylic," and "(meth)acryloyl" means "acryloyl" and its corresponding "methacryloyl."

[0013] In this specification, the number-average molecular weight (Mn) refers to the value measured in polystyrene terms by gel permeation chromatography (GPC). Specifically, the number-average molecular weight (Mn) in this specification can be measured by the method described in the examples.

[0014] In this specification, "semi-cured product" is synonymous with a resin composition in the B-stage state as defined in JIS K 6800 (1985), and "cured product" is synonymous with a resin composition in the C-stage state as defined in JIS K 6800 (1985).

[0015] The mechanism of action described herein is speculative and does not limit the mechanism by which the effects of this embodiment are achieved.

[0016] Embodiments that combine any combination of the information described herein are also included.

[0017] [Resin composition and resin] The resin composition of this embodiment is (A) A resin containing structural units derived from a maleimide resin having one or more N-substituted maleimide groups and structural units derived from an aromatic vinyl compound [hereinafter sometimes referred to as "(A) modified maleimide resin"] (B) Thermoplastic resin and It is a resin composition containing [the specified ingredient].

[0018] Furthermore, the resin of this embodiment corresponds to the modified maleimide resin described in (A) above, and is a resin that includes structural units derived from a maleimide resin having one or more N-substituted maleimide groups, and structural units derived from an aromatic vinyl compound.

[0019] In this specification, each component may be abbreviated as component (A), component (B), etc., and other components may also be abbreviated in the same manner. The following describes each component contained in the resin composition of this embodiment. The resin of this embodiment will be described as (A) modified maleimide resin.

[0020] <(A) Modified maleimide resin> (A) The modified maleimide resin is a resin containing structural units derived from a maleimide resin having one or more N-substituted maleimide groups [hereinafter sometimes simply referred to as "maleimide resin"] and structural units derived from an aromatic vinyl compound. The resin composition of this embodiment exhibits excellent dielectric properties and low thermal expansion due to the inclusion of (A) modified maleimide resin. Although the exact reason is unclear, it is presumed that the low polarity of the structural units derived from aromatic vinyl compounds in (A) modified maleimide resin, and the introduction of highly linear chains consisting of structural units derived from aromatic vinyl compounds, increase the free volume of the cured product, which contributes to the improvement of dielectric properties. Furthermore, it is presumed that the low thermal expansion is improved by π-π stacking (intermolecular interactions) between aromatic rings contained in the structural units derived from aromatic vinyl compounds. (A) Modified maleimide resin may be used alone or in combination of two or more types.

[0021] (Structural units derived from maleimide resin having one or more N-substituted maleimide groups) (A) The structural units derived from maleimide resin that the modified maleimide resin possesses are not particularly limited as long as they are structural units derived from maleimide resin. (A) The structural units derived from maleimide resin in the modified maleimide resin may be one type alone or two or more types.

[0022] The structural units derived from the maleimide resin are preferably those formed by the addition reaction of one or more N-substituted maleimide groups present in the maleimide resin. In other words, the structural units derived from the maleimide resin include groups other than one or more N-substituted maleimide groups present in the maleimide resin, and groups formed by the addition reaction of N-substituted maleimide groups, and may also include unreacted N-substituted maleimide groups that have not undergone the addition reaction. The group formed by the addition reaction of an N-substituted maleimide group is represented by the following formula.

[0023] [ka] (In the formula, * A1 This is the site that binds to the group remaining after removing the N-substituted maleimide group that was subjected to the addition reaction from the maleimide resin. A2 and * A3 (This is a bonding site to another atom.)

[0024] (A) The content of structural units derived from maleimide resin in the modified maleimide resin is not particularly limited, but from the viewpoint of dielectric properties, low thermal expansion and heat resistance, it is preferably 30 to 99% by mass, more preferably 40 to 96% by mass, and even more preferably 50 to 93% by mass.

[0025] The maleimide resin is not particularly limited as long as it is a maleimide resin having one or more N-substituted maleimide groups. From the viewpoint of conductive adhesion and heat resistance, the maleimide resin is preferably an aromatic maleimide resin having two or more N-substituted maleimide groups, and more preferably an aromatic bismaleimide resin having two N-substituted maleimide groups.

[0026] In this specification, the "aromatic maleimide resin" means a compound having an N-substituted maleimide group directly bonded to an aromatic ring. Also, in this specification, the "aromatic bismaleimide resin" means a compound having two N-substituted maleimide groups directly bonded to an aromatic ring. Further, in this specification, the "aromatic polymaleimide resin" means a compound having three or more N-substituted maleimide groups directly bonded to an aromatic ring. Also, in this specification, the "aliphatic maleimide resin" means a compound having an N-substituted maleimide group directly bonded to an aliphatic hydrocarbon.

[0027] As the maleimide resin, the maleimide resin represented by the following general formula (A-1) is preferable.

[0028]

Chemical formula

[0029] X in the above general formula (A-1) A1 is a divalent organic group. X in the above general formula (A-1) A1 Examples of the divalent organic group represented by X include a divalent organic group represented by the following general formula (A-2), a divalent organic group represented by the following general formula (A-3), a divalent organic group represented by the following general formula (A-4), a divalent organic group represented by the following general formula (A-5), a divalent organic group represented by the following general formula (A-6), a divalent organic group represented by the following general formula (A-7), and the like.

[0030]

Chemical formula

[0031] R in the above general formula (A-2) A1Examples of C1-C5 aliphatic hydrocarbon groups represented by include C1-C5 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups; C2-C5 alkenyl groups; and C2-C5 alkynyl groups. The C1-C5 aliphatic hydrocarbon group may be linear or branched. The C1-C5 aliphatic hydrocarbon group is preferably a C1-C3 aliphatic hydrocarbon group, more preferably a C1-C3 alkyl group, and even more preferably a methyl group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. n in the above general formula (A-2) A1 is an integer between 0 and 4, and from the viewpoint of availability, is preferably an integer between 0 and 2, more preferably 0 or 1, and even more preferably 0. n A1 If is an integer greater than or equal to 2, then multiple R A1 They may be the same or they may be different.

[0032] [ka] (In the formula, R A2 and R A3 Each of these is independently an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. A2 n is an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, a single bond, or a divalent organic group represented by the following general formula (A-3-1). A2 and n A3 Each of these is an independent integer between 0 and 4. * represents a connection point.

[0033] In the above general formula (A-3), R A2 and R A3Examples of C1-C5 aliphatic hydrocarbon groups represented by include C1-C5 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups; C2-C5 alkenyl groups; and C2-C5 alkynyl groups. The C1-C5 aliphatic hydrocarbon group may be linear or branched. The C1-C5 aliphatic hydrocarbon group is preferably a C1-C3 aliphatic hydrocarbon group, more preferably a C1-C3 alkyl group, and even more preferably a methyl or ethyl group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0034] X in the above general formula (A-3) A2 Examples of alkylene groups having 1 to 5 carbon atoms include methylene groups, 1,2-dimethylene groups, 1,3-trimethylene groups, 1,4-tetramethylene groups, and 1,5-pentamethylene groups. Among the alkylene groups having 1 to 5 carbon atoms, alkylene groups having 1 to 3 carbon atoms are preferred, alkylene groups having 1 or 2 carbon atoms are more preferred, and methylene groups are even more preferred.

[0035] X in the above general formula (A-3) A2 Examples of alkylidene groups having 2 to 5 carbon atoms include ethylidene, propyridene, isopropylidene, butyridene, isobutylidene, pentyridene, and isopentylidene. Among these, 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.

[0036] n in the above general formula (A-3) A2 and n A3 Each of these is an integer between 0 and 4, independently of the others. n A2 or n A3 If is an integer greater than or equal to 2, then multiple R A2 Each or multiple R A3 They may be the same or they may be different.

[0037] X in the above general formula (A-3) A2 The divalent organic group represented by the general formula (A-3-1) is as follows:

[0038] [ka] (In the formula, R A4 and R A5 Each of these is independently an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. A3 This is an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, or a single bond. A4 and n A5 Each of these is an independent integer between 0 and 4. * represents a connection point.

[0039] In the above general formula (A-3-1), R A4 and R A5 Examples of C1-C5 aliphatic hydrocarbon groups represented by include C1-C5 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups; C2-C5 alkenyl groups; and C2-C5 alkynyl groups. The C1-C5 aliphatic hydrocarbon group may be linear or branched. The C1-C5 aliphatic hydrocarbon group is preferably a C1-C3 aliphatic hydrocarbon group, more preferably a C1-C3 alkyl group, and even more preferably a methyl group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0040] X in the above general formula (A-3-1) A3Examples of alkylene groups having 1 to 5 carbon atoms include methylene groups, 1,2-dimethylene groups, 1,3-trimethylene groups, 1,4-tetramethylene groups, and 1,5-pentamethylene groups. Among the alkylene groups having 1 to 5 carbon atoms, alkylene groups having 1 to 3 carbon atoms are preferred, alkylene groups having 1 or 2 carbon atoms are more preferred, and methylene groups are even more preferred.

[0041] X in the above general formula (A-3-1) A3 Examples of alkylidene groups having 2 to 5 carbon atoms include ethylidene, propyridene, isopropylidene, butyridene, isobutylidene, pentyridene, and isopentylidene. Among these, 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.

[0042] X in the above general formula (A-3-1) A3 Among the above options, alkylidene groups having 2 to 5 carbon atoms are preferred, alkylidene groups having 2 to 4 carbon atoms are more preferred, and isopropylidene groups are even more preferred.

[0043] n in the above general formula (A-3-1) A4 and n A5 Each of these is an integer between 0 and 4, and from the viewpoint of availability, each is preferably an integer between 0 and 2, more preferably 0 or 1, and even more preferably 0. n A4 or n A5 If is an integer greater than or equal to 2, then multiple R A4 Each or multiple R A5 They may be the same or they may be different.

[0044] X in the above general formula (A-3) A2 Among the above options, alkylene groups having 1 to 5 carbon atoms, alkylidene groups having 2 to 5 carbon atoms, and divalent organic groups represented by the above general formula (A-3-1) are preferred, alkylene groups having 1 to 5 carbon atoms are more preferred, and methylene groups are even more preferred.

[0045] [ka] (In the formula, n A6 (This is an integer between 0 and 10. * represents a connection point.)

[0046] n in the above general formula (A-4) A6 From the viewpoint of availability, the integer is preferably an integer between 0 and 5, more preferably an integer between 0 and 4, and even more preferably an integer between 0 and 3.

[0047] [ka] (In the formula, n A7 (The numbers are 0-5. * represents a connection site.)

[0048] [ka] (In the formula, R A6 and R A7 Each of these is independently a hydrogen atom or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. A8 (This is an integer between 1 and 8. * represents a connection point.)

[0049] In the above general formula (A-6), R A6 and R A7 Examples of C1-C5 aliphatic hydrocarbon groups represented by include C1-C5 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups; C2-C5 alkenyl groups; and C2-C5 alkynyl groups. The C1-C5 aliphatic hydrocarbon group may be linear or branched. n in the above general formula (A-6) A8 n is an integer between 1 and 8, preferably between 1 and 5, more preferably between 1 and 3, and even more preferably 1. A8 If is an integer greater than or equal to 2, then multiple R A6Each or multiple R A7 They may be the same or they may be different.

[0050] [ka] (In the formula, R A8 This is 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, n A9 R is an integer between 0 and 3. A9 ~R A11 Each of these is an alkyl group having 1 to 10 carbon atoms. A12 Each of these is independently a C1-C10 alkyl group, a C1-C10 alkyloxy group, a C1-C10 alkylthio group, a C6-C10 aryl group, a C6-C10 aryloxy group, a C6-C10 arylthio group, a C3-C10 cycloalkyl group, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. A10 Each of these is an integer between 0 and 4, and n A11 The value is between 0.95 and 10.0. (* indicates a binding site.)

[0051] In the above general formula (A-7), R A8 Examples of C1-C10 alkyl groups represented by include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. These alkyl groups may be linear or branched. R A8 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. R A8 Examples of aryl groups having 6 to 10 carbon atoms, represented by this formula, include phenyl groups and naphthyl groups. RA8 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. R A8 Examples of cycloalkyl groups having 3 to 10 carbon atoms represented by include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl groups. n in the above general formula (A-7) A9 If R is an integer between 1 and 3, A8 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.

[0052] R A9 ~R A11 Examples of alkyl groups having 1 to 10 carbon atoms represented by R include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. These alkyl groups may be linear or branched. Among these, R A9 ~R A11 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. n in the above general formula (A-7) A9 n is an integer between 0 and 3. A9 If the number is 2 or 3, then multiple R A8 They may be the same or they may be different.

[0053] Among the above, the divalent organic group represented by the general formula (A-7) is considered to have compatibility with other resins, solvent solubility, dielectric properties, adhesion to conductors, and ease of manufacture, n A9 If R is 0, A9 ~R A11 It is preferable that the group is a methyl group, which is a divalent organic group.

[0054] In the above general formula (A-7), multiple RA8 among themselves, a plurality of R A12 among themselves, a plurality of n A9 among themselves, a plurality of n A10 among themselves may each be the same or different. Also, when n A11 exceeds 1, a plurality of R A9 among themselves, a plurality of R A10 among themselves and a plurality of R A11 among themselves may each be the same or different.

[0055] The R in the general formula (A-7) above A12 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, and a cycloalkyl group having 3 to 10 carbon atoms. The description thereof is the same as the description of the alkyl group having 1 to 10 carbon atoms, the alkyloxy group having 1 to 10 carbon atoms, the alkylthio group having 1 to 10 carbon atoms, the aryl group having 6 to 10 carbon atoms, the aryloxy group having 6 to 10 carbon atoms, the arylthio group having 6 to 10 carbon atoms, and the cycloalkyl group having 3 to 10 carbon atoms represented by the above R A8 is the same as the description of the alkyl group having 1 to 10 carbon atoms, the alkyloxy group having 1 to 10 carbon atoms, the alkylthio group having 1 to 10 carbon atoms, the aryl group having 6 to 10 carbon atoms, the aryloxy group having 6 to 10 carbon atoms, the arylthio group having 6 to 10 carbon atoms, and the cycloalkyl group having 3 to 10 carbon atoms represented by the above R. Among these, R A12 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, from the viewpoints of compatibility with other resins, solvent solubility, dielectric properties, adhesion to conductors, and ease of production. The n in the general formula (A-7) above A10 is an integer of 0 to 4, and is preferably an integer of 0 to 3, more preferably 0 or 2, from the viewpoints of compatibility with other resins, solvent solubility, dielectric properties, adhesion to conductors, and ease of production. In addition, when n A10 is 1 or more, the benzene ring and the N-substituted maleimide group have a twisted conformation, and the solvent solubility tends to be further improved by suppressing intermolecular stacking. From the same viewpoint, when n A10 is 1 or more, R A12The replacement position is preferably ortho to the N-substituted maleimide group. n in the general formula (A-7) above A11 From the viewpoints of compatibility with other resins, solvent solubility, melt viscosity, handling properties, and heat resistance, it is preferably 0.98 to 8.0, more preferably 1.0 to 7.0, and still more preferably 1.1 to 6.0.

[0056] The divalent organic group represented by the general formula (A-7) preferably includes a divalent organic group represented by the following general formula (A-7-1), a divalent organic group represented by the following general formula (A-7-2), a divalent organic group represented by the following general formula (A-7-3), a divalent organic group represented by the following general formula (A-7-4), and the like.

[0057]

Chemical formula

[0058] Examples of the maleimide resin include aromatic bismaleimide resins, aromatic polymaleimide resins, aliphatic maleimide resins, etc. Among these, aromatic bismaleimide resins are preferred. Specific examples of maleimide resins include N,N'-ethylenebismaleimide, N,N'-hexamethylenebismaleimide, N,N'-(1,3-phenylene)bismaleimide, N,N'-[1,3-(2-methylphenylene)]bismaleimide, N,N'-[1,3-(4-methylphenylene)]bismaleimide, N,N'-(1,4-phenylene)bismaleimide, bis(4-maleimidophenyl)methane, bis(3-methyl-4-maleimidophenyl)methane, and 3,3'-dimethyl-5,5'-diethyl-4,4 '-diphenylmethanebismaleimide, bis(4-maleimidophenyl) ether, bis(4-maleimidophenyl) sulfone, bis(4-maleimidophenyl) sulfide, bis(4-maleimidophenyl) ketone, bis(4-maleimidocyclohexyl)methane, 1,4-bis(4-maleimidophenyl)cyclohexane, 1,4-bis(maleimidomethyl)cyclohexane, 1,4-bis(maleimidomethyl)benzene, 1,3-bis(4-maleimidophenoxy)benzene, 1,3-bis(3-maleim (Phenoxy)benzene, bis[4-(3-maleimidophenoxy)phenyl]methane, bis[4-(4-maleimidophenoxy)phenyl]methane, 1,1-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,1-bis[4-(4-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(4-maleimidophenoxy)phenyl]ethane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]propane, 2 ,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4-bis(3-maleimidophenoxy)biphenyl, 4,4-Bis(4-maleimidophenoxy)biphenyl, bis[4-(3-maleimidophenoxy)phenyl]ketone, bis[4-(4-maleimidophenoxy)phenyl]ketone, bis(4-maleimidophenoxy)disulfide, bis[4-(3-maleimidophenoxy)phenyl]sulfide, bis[4-(4-maleimidophenoxy)phenyl]sulfide, bis[4-(3-maleimidophenoxy)phenyl]sulfoxide, bi bis[4-(4-maleimidophenoxy)phenyl]sulfoxide, bis[4-(3-maleimidophenoxy)phenyl]sulfone, bis[4-(4-maleimidophenoxy)phenyl]sulfone, bis[4-(3-maleimidophenoxy)phenyl]ether, bis[4-(4-maleimidophenoxy)phenyl]ether, 1,4-bis[4-(4-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis [4-(4-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-maleimidophenoxy) Examples include -3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, polyphenylmethanemaleimide, aromatic bismaleimide resins having an indan skeleton, and biphenylaralkyl type maleimide resins. Among these, biphenylaralkyl type maleimide resins are preferred.

[0059] (Structural units derived from aromatic vinyl compounds) (A) The structural units derived from aromatic vinyl compounds in the modified maleimide resin may be one type alone or two or more types.

[0060] The structural units derived from aromatic vinyl compounds are preferably those formed by the addition reaction of the vinyl group of the aromatic vinyl compound. In other words, the structural units derived from aromatic vinyl compounds include at least a group other than the vinyl group present in the aromatic vinyl compound, and a group formed by the addition reaction of the vinyl group.

[0061] (A) The content of structural units derived from aromatic vinyl compounds in the modified maleimide resin is not particularly limited, but is preferably 1 to 70% by mass, more preferably 4 to 60% by mass, and even more preferably 7 to 50% by mass, from the viewpoint of dielectric properties, low thermal expansion and heat resistance.

[0062] Aromatic vinyl compounds are compounds that have a vinyl group bonded to an aromatic ring. Examples of aromatic rings to which the vinyl group is bonded include benzene rings, naphthalene rings, and anthracene rings, but benzene rings are preferred. From the viewpoint of suppressing gelation, the number of vinyl groups bonded to the aromatic ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. Examples of aromatic vinyl compounds include styrene compounds such as styrene, α-methylstyrene, α-methylstyrene dimer, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-t-butylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, 4-methoxystyrene, N,N-diethyl-4-aminoethylstyrene, monochlorostyrene, and dichlorostyrene; and 1-vinylnaphthalene, 2-vinylnaphthalene, vinylanthracene, vinylpyridine, and divinylbenzene. Among these, styrene compounds are preferred, and α-methylstyrene dimer is more preferred. Since α-methylstyrene dimer is an aromatic vinyl compound and acts as a cleavage-type chain transfer agent in addition polymerization reactions, (A) modified maleimide resins using α-methylstyrene dimer as the aromatic vinyl compound tend to yield good molecular weights.

[0063] ((A) Number-average molecular weight (Mn) of modified maleimide resin) (A) The number-average molecular weight (Mn) of the modified maleimide resin is not particularly limited, but from the viewpoint of handling and moldability, it is preferably 400 to 5,000, more preferably 500 to 3,000, and even more preferably 700 to 2,000.

[0064] ((A) Method for producing modified maleimide resin) (A) Modified maleimide resin can be produced, for example, by an addition polymerization reaction between maleimide resin and an aromatic vinyl compound in an organic solvent. When carrying out the addition polymerization reaction between maleimide resin and aromatic vinyl compounds, a polymerization initiator may be used as needed. Examples of polymerization initiators include organic peroxides such as dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, and α,α'-bis(t-butylperoxy)diisopropylbenzene. These may be used individually or in combination of two or more. The amount of polymerization initiator used is not particularly limited, but from the viewpoint of reaction rate and reaction uniformity, it is preferably 0.1 to 5 parts by mass, more preferably 0.3 to 3 parts by mass, and even more preferably 0.5 to 1.5 parts by mass, per 100 parts by mass of the total amount of maleimide resin and aromatic vinyl compound.

[0065] When reacting maleimide resin with aromatic vinyl compounds, a chain transfer agent may be used as needed. Examples of chain transfer agents include thiol-based chain transfer agents such as 2-mercaptoethanol, butanethiol, octanthiol, decanethiol, dodecanethiol, hexadecanethiol, and thiophenol; and carbon tetrachloride. These may be used individually or in combination of two or more.

[0066] The organic solvent used in the reaction between maleimide resin and aromatic vinyl compound can be one of the organic solvents described later. Among these, toluene is preferred from the viewpoint of solubility.

[0067] The reaction temperature for the addition polymerization reaction is preferably 50 to 160°C, more preferably 60 to 150°C, and even more preferably 70 to 140°C, from the viewpoint of workability such as reaction rate and suppression of gelation of the product during the reaction. The reaction time for the addition polymerization reaction is preferably 0.2 to 5 hours, more preferably 0.5 to 4 hours, and even more preferably 1 to 3 hours, from the viewpoint of productivity and ensuring the reaction proceeds sufficiently. However, these reaction conditions can be adjusted as appropriate depending on the type of raw materials used, and are not particularly limited.

[0068] ((A) Content of modified maleimide resin) The content of (A) modified maleimide resin in the resin composition of this embodiment is not particularly limited, but is preferably 10 to 90% by mass, more preferably 20 to 70% by mass, and even more preferably 40 to 60% by mass, based on the total amount (100% by mass) of resin components in the resin composition of this embodiment. (A) When the content of modified maleimide resin is above the lower limit, heat resistance, moldability, processability, and conductor adhesion tend to be better. Also, when the content of modified maleimide resin is below the upper limit, dielectric properties tend to be better.

[0069] Herein, in this specification, "resin component" means resin and compounds that form resin through a curing reaction. For example, in the resin composition of this embodiment, component (A) and component (B) correspond to resin components. If the resin composition of this embodiment contains, as an optional component, a resin or a compound that forms a resin through a curing reaction, in addition to the above-mentioned components, these optional components are also included in the resin components. Examples of optional components corresponding to the resin components include component (C), which will be described later. On the other hand, components (D) and (E) shall not be included in the resin components.

[0070] The total content of resin components in the resin composition of this embodiment is not particularly limited, but from the viewpoint of low thermal expansion, heat resistance, flame retardancy, and conductive adhesion, it is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, and even more preferably 40 to 60% by mass, relative to the total solid content (100% by mass) of the resin composition of this embodiment.

[0071] <(B) Thermoplastic resin> (B) Examples of thermoplastic resins include polyphenylene ether resins, styrene elastomers, polyolefin resins (excluding component (C) described later), silicone resins, epoxy resins, polyurethane resins, polyester resins, polyamide resins, and polyacrylic resins. Among these, from the viewpoint of compatibility with component (A), dielectric properties and conductive adhesion, it is preferable that the thermoplastic resin (B) contains one or more selected from the group consisting of (B1) polyphenylene ether resins and (B2) styrene elastomers. (B) Thermoplastic resins may be used individually or in combination of two or more types.

[0072] ((B1) Polyphenylene ether resin) (B) The thermoplastic resin preferably contains (B1) a polyphenylene ether resin. (B1) Examples of polyphenylene ether resins include one or more selected from the group consisting of polyphenylene ethers and polyphenylene ether derivatives. (B1) The polyphenylene ether resin preferably has a structural unit represented by the following general formula (B-1).

[0073] [ka] (In the formula, R B1 Each of these is independently an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. B1 (This is an integer between 0 and 4.)

[0074] In the above general formula (B-1), R B1 Each of these is independently an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. Aliphatic hydrocarbon group having 1 to 3 carbon atoms is preferred, and a methyl group is more preferred. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among the above, R B1 Preferably, it is an aliphatic hydrocarbon group having 1 to 5 carbon atoms. n B1 n is an integer between 0 and 4, and may be an integer of 1 or 2, or it may be 2. B1 If R is 1 or 2, B1 The substitution may occur at the ortho position on the benzene ring (referring to the substitution position of the oxygen atom). Also, n B1 If the number is 2 or more, multiple R B1 The individuals may be identical or different. The structural unit represented by the above general formula (B-1) is preferably, more specifically, the structural unit represented by the following general formula (B-1').

[0075] [ka]

[0076] (B1) The number-average molecular weight (Mn) of the polyphenylene ether resin is not particularly limited, but is preferably 1,000 to 25,000, more preferably 2,000 to 20,000, and even more preferably 3,000 to 10,000. (B1) When the number average molecular weight (Mn) of the polyphenylene ether resin is above the lower limit, the dielectric properties tend to be even better. Also, when the number average molecular weight (Mn) of the polyphenylene ether resin is below the upper limit, the compatibility of the resin composition tends to be good.

[0077] (B1) The polyphenylene ether resin is preferably a polyphenylene ether derivative having an ethylenically unsaturated bond-containing group. In this specification, "ethylenically unsaturated bond" means a carbon-carbon double bond capable of addition reactions, and does not include double bonds in aromatic rings. Furthermore, in this specification, "ethylenically unsaturated bond-containing group" means a substituent containing the above-mentioned ethylenically unsaturated bond.

[0078] In a polyphenylene ether derivative having an ethylenically unsaturated bond-containing group, the position of the ethylenically unsaturated bond-containing group is not particularly limited; for example, it may be located at one end or at both ends. (B1) When the polyphenylene ether resin contains a polyphenylene ether derivative having an ethylenically unsaturated bond-containing group at one end, the content of the polyphenylene ether derivative having an ethylenically unsaturated bond-containing group at one end in the (B1) polyphenylene ether resin is not particularly limited, but may be 30% by mass or more, 45% by mass or more, 55% by mass or more, 70% by mass or more, 90% by mass or more, or substantially 100% by mass.

[0079] Examples of ethylenically unsaturated bond-containing groups include unsaturated aliphatic hydrocarbon groups such as vinyl groups, isopropenyl groups, allyl groups, 1-methylallyl groups, and 3-butenyl groups; and substituents containing heteroatoms such as maleimide groups and (meth)acryloyl groups. Among these, from the viewpoint of dielectric properties, unsaturated aliphatic hydrocarbon groups or maleimide groups are preferred, allyl groups or maleimide groups are more preferred, and allyl groups are even more preferred. In this specification, groups that have a portion of an unsaturated aliphatic hydrocarbon group, such as maleimide groups and (meth)acryloyl groups, but cannot be considered an unsaturated aliphatic hydrocarbon group when viewed as a whole, are not included in the above-mentioned "unsaturated aliphatic hydrocarbon group".

[0080] (B1) The number of ethylenically unsaturated bond-containing groups in one molecule of the polyphenylene ether resin is not particularly limited, but from the viewpoint of dielectric properties, it is preferably 2 or more, more preferably 4 or more, and may be 8 or less, or 6 or less. Furthermore, from the viewpoint of dielectric properties, the number of ethylenically unsaturated bond-containing groups that the (B1) polyphenylene ether resin has at one end is preferably 2 or more, more preferably 4 or more, and may also be 8 or less, or 6 or less.

[0081] (B1) From the viewpoint of dielectric properties, the polyphenylene ether resin preferably contains a structure represented by the following general formula (B-2).

[0082] [ka] (In the formula, R B2 Each of these is an unsaturated aliphatic hydrocarbon group having 2 to 10 carbon atoms. B2 is 1 or 2, and n B3 (This value is either 0 or 1. * represents a binding site.)

[0083] In the above general formula (B-2), R B2Examples of unsaturated aliphatic hydrocarbon groups having 2 to 10 carbon atoms that can be represented by include vinyl groups, isopropenyl groups, allyl groups, 1-methylallyl groups, and 3-butenyl groups. Among these, unsaturated aliphatic hydrocarbon groups having 2 to 5 carbon atoms are preferred from the viewpoint of dielectric properties, and allyl groups are more preferred.

[0084] Furthermore, (B1) polyphenylene ether resins are also preferable in which the structure is represented by the following general formula (B-3) from the viewpoint of dielectric properties.

[0085] [ka] (In the formula, R B3 and R B4 These are, independently, unsaturated aliphatic hydrocarbon groups having 2 to 10 carbon atoms. (* indicates a bonding site.)

[0086] In the above general formula (B-3), R B3 and R B4 The unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms represented by R in the general formula (B-2) above. B2 The same items are listed, and the same items are preferred.

[0087] (B1) From the viewpoint of dielectric properties, the polyphenylene ether resin more preferably contains a structure represented by any of the following general formulas (B-4) to (B-6), and even more preferably contains a structure represented by the following general formula (B-6).

[0088] [ka] (In the formula, R B5 This is an unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms. (* indicates a bonding site.)

[0089] [ka] (In the formula, R B6 and RB7 Each of these is an unsaturated aliphatic hydrocarbon group having 2 to 10 carbon atoms. B1 This is a divalent aliphatic hydrocarbon group with 1 to 6 carbon atoms. (* indicates a bonding site.)

[0090] [ka] (In the formula, R B8 ~R B11 Each of these is an unsaturated aliphatic hydrocarbon group having 2 to 10 carbon atoms. B2 (This is a divalent organic group. * indicates a bonding site.)

[0091] In the above general formulas (B-4) to (B-6), R B5 ~R B11 The unsaturated aliphatic hydrocarbon group with 2 to 10 carbon atoms represented by is R in the general formula (B-2) above. B2 The same items as in the previous case are listed, and the preferred items are also the same. X in the above general formula (B-5) B1 Examples of divalent aliphatic hydrocarbon groups having 1 to 6 carbon atoms that can be represented include alkylene groups having 1 to 6 carbon atoms, such as methylene, ethylene, and trimethylene groups; and alkylidene groups having 2 to 6 carbon atoms, such as isopropylidene groups. Among these, methylene and isopropylidene groups are preferred, with isopropylidene groups being more preferred. X in the above general formula (B-6) B2 Examples of divalent organic groups represented by include aliphatic hydrocarbon groups that may contain heteroatoms, alicyclic hydrocarbon groups that may contain heteroatoms, aromatic hydrocarbon groups that may contain heteroatoms, and groups consisting of any combination thereof. Examples of the heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, etc. B2The divalent organic group represented is preferably a group that does not contain a heteroatom, more preferably an aliphatic hydrocarbon group that does not contain a heteroatom, more preferably an alicyclic hydrocarbon group that does not contain a heteroatom, and even more preferably a group consisting of a combination of an aliphatic hydrocarbon group that does not contain a heteroatom and an alicyclic hydrocarbon group that does not contain a heteroatom.

[0092] Of the structures represented by the above general formulas (B-4), (B-5), or (B-6), more preferred embodiments are those represented by the following formulas (B-4'), (B-5'), or (B-6'), respectively, from the viewpoint of dielectric properties. Among these, from the viewpoint of dielectric properties, the structures represented by the following formulas (B-5') or (B-6') are more preferred, and the structure represented by the following formula (B-6') is even more preferred.

[0093] [ka] (In the formula, X B2 X in the above general formula (B-6) is B2 It is the same as (* indicates a binding site).

[0094] (B1) The polyphenylene ether resin may contain a polyphenylene ether derivative represented by any of the following general formulas (B-7) to (B-9), and it is particularly preferable that it contains a polyphenylene ether derivative represented by the following general formula (B-8) or (B-9), and more preferably that it contains a polyphenylene ether derivative represented by the following general formula (B-9).

[0095] [ka] (In the formula, X B2 X in the above general formula (B-6) is B2 It is the same as n B4 ~n B6 Each of these is an integer between 1 and 200, independently of the others.

[0096] In the above general formulas (B-7) to (B-9), n B4 ~n B6 Each of these is an integer from 1 to 200, and from the viewpoint of dielectric properties and compatibility with the resin composition, it may be an integer of 1 or more, an integer of 10 or more, an integer of 20 or more, or an integer of 25 or more. Also, from a similar viewpoint, n B4 ~n B6 Each of these can be an integer less than or equal to 150, an integer less than or equal to 120, or an integer less than or equal to 100, independently of the others. In any of the above general formulas (B-7) to (B-9), n B4 ~n B6 It may also be a mixture of polyphenylene ether derivatives with different values, and usually tends to be a mixture.

[0097] (B1) Polyphenylene ether resins can be prepared, for example, by redistributing a raw material polyphenylene ether with a phenol compound. The above redistribution reaction involves, for example, mixing a phenol compound with a pre-polymerized polyphenylene ether in an organic solvent, and adding a reaction catalyst as needed. The oxy radical of the phenol compound attacks the carbon atom to which the oxygen atom in the polyphenylene ether is bonded, breaking the OC bond and reducing the molecular weight. In this process, the attacked oxy radical of the phenol compound bonds with the broken carbon atom and is incorporated into the structure of the polyphenylene ether. Known methods can be used and applied for this redistribution reaction. As the raw material polyphenylene ether, for example, a polyphenylene ether with a number-average molecular weight (Mn) of 3,000 to 30,000 can be used.

[0098] When preparing a (B1) polyphenylene ether derivative having an ethylenically unsaturated bond-containing group, it is preferable to use a phenol compound containing an unsaturated aliphatic hydrocarbon group, specifically, a phenol compound containing a structure represented by any of the above general formulas (B-2) to (B-6).

[0099] When the resin composition of this embodiment contains (B1) polyphenylene ether resin, the content of (B1) polyphenylene ether resin is not particularly limited, but is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, and even more preferably 3 to 10% by mass, relative to the total amount (100% by mass) of resin components in the resin composition of this embodiment. (B1) When the content of polyphenylene ether resin is above the lower limit above, the dielectric properties tend to be better. Also, when the content of polyphenylene ether resin is below the upper limit above, the heat resistance and flame retardancy tend to be better.

[0100] ((B2) Styrene-based elastomer) (B) The thermoplastic resin preferably contains (B2) a styrene-based elastomer. (B2) There are no particular restrictions on the styrene-based elastomer as long as it is an elastomer having structural units derived from a styrene-based compound. The resin composition of this embodiment tends to yield better dielectric properties by containing (B2) styrene-based elastomer. In this context, "elastomer" refers to a polymer whose glass transition temperature, as measured by differential scanning calorimetry in accordance with JIS K 6240:2011, is 25°C or lower. (B2) Styrene elastomers may be used individually or in combination of two or more types.

[0101] (B2) As for the styrene-based elastomer, it is preferable to have a structural unit derived from a styrene-based compound represented by the following general formula (B-10).

[0102] [ka] (In the formula, R B12 R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. B13 n is an alkyl group having 1 to 5 carbon atoms. B7 (This is an integer between 0 and 5.)

[0103] In the above general formula (B-10), R B12 and R B13 Examples of C1-C5 alkyl groups represented by include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. C1-C5 alkyl groups may be linear or branched. Among these, C1-C3 alkyl groups are preferred, C1 or C2 alkyl groups are more preferred, and methyl groups are even more preferred. n in the above general formula (B-10) B7 is an integer between 0 and 5, preferably between 0 and 2, more preferably 0 or 1, and even more preferably 0.

[0104] (B2) Styrene-based elastomers may contain structural units other than those derived from styrene-based compounds. (B2) Structural units other than those derived from styrene compounds that may be contained in the styrene elastomer include, for example, structural units derived from butadiene, structural units derived from isoprene, structural units derived from maleic acid, structural units derived from maleic anhydride, and so on. The butadiene-derived structural units and isoprene-derived structural units described above may be hydrogenated. When hydrogenated, the butadiene-derived structural units become structural units that are a mixture of ethylene units and butylene units, and the isoprene-derived structural units become structural units that are a mixture of ethylene units and propylene units.

[0105] (B2) Examples of styrene-based elastomers include hydrogenated styrene-butadiene-styrene block copolymers, hydrogenated styrene-isoprene-styrene block copolymers, and styrene-maleic anhydride copolymers. Hydrogenated styrene-butadiene-styrene block copolymers include SEBS, which is obtained by fully hydrogenating the carbon-carbon double bonds in the butadiene block, and SBBS, which is obtained by partially hydrogenating the carbon-carbon double bonds at the 1,2-bonding sites in the butadiene block. In SEBS, full hydrogenation usually means that the hydrogenation rate of the total carbon-carbon double bonds is 90% or more, may be 95% or more, 99% or more, or 100%. In SBBS, the partial hydrogenation rate is, for example, 60-85% of the total carbon-carbon double bonds. Hydrogenated styrene-isoprene-styrene block copolymers are obtained as SEPS by hydrogenating the polyisoprene portion. Among these, SEBS and SEPS are preferred from the viewpoint of dielectric properties, conductor adhesion, heat resistance, glass transition temperature, and low thermal expansion, with SEBS being more preferred.

[0106] In the above-mentioned SEBS, the content of structural units derived from styrene compounds [hereinafter sometimes referred to as "styrene content"] is not particularly limited, but is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 20 to 40% by mass.

[0107] (B2) Examples of commercially available styrene-based elastomers include the ToughTec® H series and M series from Asahi Kasei Corporation, the Septon® series from Kuraray Co., Ltd., and the Kraton® G polymer series from Kraton Polymer Japan Co., Ltd.

[0108] (B2) The number-average molecular weight (Mn) of the styrene-based elastomer is not particularly limited, but is preferably 10,000 to 500,000, more preferably 30,000 to 300,000, and even more preferably 50,000 to 200,000.

[0109] When the resin composition of this embodiment contains (B2) styrene-based elastomer, the content of (B2) styrene-based elastomer is not particularly limited, but is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 20 to 40% by mass, relative to the total amount (100% by mass) of resin components in the resin composition of this embodiment. (B2) When the content of styrene-based elastomer is above the lower limit, the dielectric properties tend to be better. Also, when the content of styrene-based elastomer is below the upper limit, the heat resistance and flame retardancy tend to be better.

[0110] The total content of (B) thermoplastic resin in the resin composition of this embodiment is not particularly limited, but is preferably 10 to 65% by mass, more preferably 15 to 55% by mass, and even more preferably 25 to 45% by mass, relative to the total amount (100% by mass) of resin components in the resin composition of this embodiment. (B) When the total content of thermoplastic resin is above the lower limit, the dielectric properties tend to be better. Also, (B) when the total content of thermoplastic resin is below the upper limit, the heat resistance and flame retardancy tend to be better.

[0111] <(C) Crosslinking agent having two or more ethylenically unsaturated bonds> The resin composition of this embodiment tends to have particularly excellent heat resistance and dielectric properties by containing a crosslinking agent having two or more ethylenically unsaturated bonds (C).

[0112] The ethylenically unsaturated bond in component (C) is, for example, an unsaturated aliphatic hydrocarbon group such as a vinyl group, isopropenyl group, allyl group, 1-methylallyl group, or 3-butenyl group; or an unsaturated bond contained in substituents containing heteroatoms such as a maleimide group or (meth)acryloyl group. Among these, from the viewpoint of dielectric properties, component (C) is preferably one in which the ethylenically unsaturated bond is contained as an unsaturated aliphatic hydrocarbon group, and more preferably as a vinyl group.

[0113] (C) The number of ethylenically unsaturated bonds in one molecule of component C is preferably 3 or more, more preferably 5 or more, and even more preferably 10 or more, from the viewpoint of obtaining excellent heat resistance.

[0114] (C) Component may include, for example, 1,2,4-trivinylcyclohexane, 1,4-butanediol divinyl ether, nonanediol divinyl ether, 1,4-cyclohexane dimethanol divinyl ether, triethylene glycol divinyl ether, trimethylolpropane trivinyl ether, pentaerythritol tetravinyl ether, divinylbenzene, divinylbiphenyl, 1,3-bis(vinyloxy)adamantane, 1,3,5-tris(vinyloxy)adamantane, vinylcyclohexene, polybutadiene having two or more 1,2-vinyl groups, butadiene-styrene copolymer having two or more 1,2-vinyl groups, and other monomers or polymers having two or more ethylenically unsaturated bonds as vinyl groups; diallyl phthalate, triallyl trimellitate, diethylene glycol bisallyl carbonate, trimethylolpropane diallyl ether, trimethylolpropane triallyl ether Examples include monomers or polymers having two or more ethylenically unsaturated bonds as allyl groups, such as pentaerythritol trialyl ether, pentaerythritol tetraallyl ether, trialyl cyanurate, trialyl isocyanurate, diallyl monobenzyl isocyanurate, diallyl ether of bisphenol S, 1,3-bis(allyloxy)adamantane, 1,3,5-tris(allyloxy)adamantane, diallyl ether, bisphenol A diallyl ether, 2,5-diallylphenol allyl ether, novolacphenol allyl ether, and allylated polyphenylene oxide; compounds having two or more ethylenically unsaturated bonds as diisopropenyl groups, such as 1,3-diisopropenylbenzene and 1,4-diisopropenylbenzene; and diene compounds having two or more ethylenically unsaturated bonds, such as 1,5-hexadiene, 1,9-decadiene, and dicyclopentadiene. Among these, polymers having two or more ethylenically unsaturated bonds as vinyl groups are preferred from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion, and heat resistance, polybutadiene having two or more 1,2-vinyl groups, butadiene-styrene copolymer having two or more 1,2-vinyl groups are more preferred, and polybutadiene having two or more 1,2-vinyl groups is even more preferred. In this specification, when "polybutadiene" is simply referred to, it means butadiene homopolymer. Specifically, as component (C), a butadiene homopolymer having two or more 1,2-vinyl groups is preferred. (C) Component may be used alone or in combination of two or more types.

[0115] (C) When component is polybutadiene having two or more 1,2-vinyl groups, the content of structural units having 1,2-vinyl groups relative to the total structural units derived from butadiene constituting the polybutadiene [hereinafter sometimes abbreviated as "vinyl group content"] is not particularly limited, but is preferably 40 to 97% by mass, more preferably 50 to 96% by mass, and even more preferably 60 to 95% by mass.

[0116] ((C) Content of crosslinking agent having two or more ethylenically unsaturated bonds) If the resin composition of this embodiment contains component (C), the content of component (C) is not particularly limited, but is preferably 1 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 10 to 30% by mass, relative to the total amount (100% by mass) of resin components in the resin composition of this embodiment. When the content of component (C) is above the lower limit, the dielectric properties tend to be better. Also, when the content of component (C) is below the upper limit, the heat resistance and flame retardancy tend to be better.

[0117] <(D) Inorganic filler> The resin composition of this embodiment preferably further contains (D) an inorganic filler from the viewpoint of low thermal expansion, elastic modulus, heat resistance, and flame retardancy. (D) The inorganic filler may be used individually or in combination of two or more types.

[0118] (D) Examples of inorganic fillers include silica, alumina, titanium oxide, 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, clay, talc, aluminum borate, silicon carbide, etc. Among these, silica, alumina, mica, and talc are preferred from the viewpoint of low thermal expansion, elastic modulus, heat resistance, and flame retardancy, silica and alumina are more preferred, and silica is even more preferred. Examples of silica include precipitated silica, which is produced by a wet process and has a high water content, and dry-process silica, which is produced by a dry process and contains almost no bound water. Furthermore, dry-process silica can be further categorized by manufacturing method into crushed silica, fumed silica, fused silica, etc.

[0119] (D) The average particle size of the inorganic filler is not particularly limited, but is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm, even more preferably 0.2 to 1 μm, and especially preferably 0.3 to 0.8 μm. Here, (D) the average particle diameter of the inorganic filler 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%. (D) The particle size of the inorganic filler can be measured using a particle size distribution analyzer that uses laser diffraction scattering. (D) Examples of inorganic filler shapes include spherical and crushed, with spherical being preferred.

[0120] If the resin composition of this embodiment contains (D) an inorganic filler, a coupling agent may be used to improve the dispersibility of (D) the inorganic filler and its adhesion to the organic component. Examples of coupling agents include silane coupling agents and titanate coupling agents.

[0121] ((D) Content of inorganic fillers) If the resin composition of this embodiment contains (D) an inorganic filler, the amount of (D) an inorganic filler is not particularly limited, but from the viewpoint of low thermal expansion, elastic modulus, heat resistance and flame retardancy, it is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, and even more preferably 40 to 60% by mass, relative to the total solid content (100% by mass) of the resin composition of this embodiment.

[0122] <(E) Curing accelerator> From the viewpoint of improving curability, the resin composition of this embodiment preferably further contains (E) a curing accelerator. (E) The curing accelerator may be used alone or in combination of two or more types.

[0123] (E) Examples of curing accelerators include acidic catalysts such as p-toluenesulfonic acid; amine compounds such as triethylamine, pyridine, and tributylamine; imidazole compounds such as methylimidazole and phenylimidazole; isocyanate-mask imidazole compounds such as the addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole; tertiary amine compounds; quaternary ammonium compounds; phosphorus compounds such as triphenylphosphine; organic peroxides such as dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, and α,α'-bis(t-butylperoxy)diisopropylbenzene; and carboxylates of manganese, cobalt, zinc, etc. Among these, isocyanate mask imidazole compounds and organic peroxides are preferred from the viewpoint of heat resistance, glass transition temperature, and storage stability.

[0124] ((E) Content of curing accelerator) If the resin composition of this embodiment contains (E) a curing accelerator, the amount of (E) the curing accelerator is not particularly limited, but is preferably 0.1 to 10 parts by mass, more preferably 1 to 8 parts by mass, and even more preferably 2 to 6 parts by mass, based on 100 parts by mass of the total amount of resin components in the resin composition of this embodiment. (E) When the content of the curing accelerator is above the lower limit, dielectric properties, heat resistance, adhesion to conductors, elastic modulus, and glass transition temperature tend to be better. Also, (E) when the content of the curing accelerator is below the upper limit, storage stability tends to be better.

[0125] <Other ingredients> The resin composition of this embodiment may further contain, if necessary, one or more additives selected from the group consisting of resin materials other than the above-mentioned components, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, lubricants, flame retardants, and other additives. Each of these may be used individually or in combination of two or more. Furthermore, the amount used is not particularly limited and may be used as needed, within a range that does not impair the effects of this embodiment.

[0126] (Organic solvents) The resin composition of this embodiment may contain an organic solvent, from the viewpoint of facilitating handling and facilitating the production of the prepreg described later. Organic solvents may be used individually or in combination of two or more types. In this specification, a resin composition containing an organic solvent may be referred to as a resin varnish.

[0127] Examples of organic solvents include alcohol-based solvents such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based solvents such as tetrahydrofuran; aromatic hydrocarbon-based solvents such as toluene, xylene, and mesitylene; nitrogen-containing solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfur-containing solvents such as dimethyl sulfoxide; and ester-based solvents such as γ-butyrolactone. Among these, from the viewpoint of solubility, alcohol-based solvents, ketone-based solvents, nitrogen atom-containing solvents, and aromatic hydrocarbon-based solvents are preferred, aromatic hydrocarbon-based solvents are more preferred, and toluene is even more preferred.

[0128] <Permittivity (Dk) of the cured material> The relative permittivity (Dk) of the cured resin composition of this embodiment at 10 GHz is not particularly limited, but is preferably 3.5 or less, more preferably 3.3 or less, and even more preferably 3.0 or less. A smaller relative permittivity (Dk) is preferable, and there is no particular limit to its lower limit, but considering the balance with other physical properties, it may be, for example, 2.4 or more, or 2.5 or more. The relative permittivity (Dk) mentioned above is a value obtained in accordance with the cavity resonator perturbation method, and more specifically, it is a value measured by the method described in the examples.

[0129] <Dielectric loss tangent (Df) of the hardened material> The dielectric loss tangent (Df) of the cured resin composition of this embodiment at 10 GHz is not particularly limited, but is preferably 0.0050 or less, more preferably 0.0040 or less, and even more preferably 0.0030 or less. The smaller the dielectric loss tangent (Df), the better. There is no particular limit to its lower limit, but considering the balance with other physical properties, it may be, for example, 0.0010 or more, or 0.0015 or more. The above dielectric loss tangent (Df) is a value obtained in accordance with the cavity resonator perturbation method, and more specifically, it is a value measured by the method described in the examples.

[0130] [Method for producing resin compositions] The method for producing the resin composition of this embodiment is a method for producing a resin composition by blending a maleimide resin having one or more N-substituted maleimide groups, an aromatic vinyl compound, and a thermoplastic resin. The description of the maleimide resin having one or more N-substituted maleimide groups and the aromatic vinyl compound used in the method for producing the resin composition of this embodiment is the same as the description of the maleimide resin having one or more N-substituted maleimide groups and the aromatic vinyl compound used in the production of component (A) contained in the resin composition of this embodiment. The description of the thermoplastic resin used in the method for producing the resin composition of this embodiment is the same as the description of the thermoplastic resin described as component (B) contained in the resin composition of this embodiment.

[0131] In the method for producing the resin composition of this embodiment, the order in which each component is added is not particularly limited, but the order in which a reaction product obtained by blending and reacting a maleimide resin having one or more N-substituted maleimide groups and an aromatic vinyl compound is added, and a thermoplastic resin is added. By using this blending order, it is possible to prepare the (A) modified maleimide resin contained in the resin composition of this embodiment well. The preferred reaction conditions for the maleimide resin having one or more N-substituted maleimide groups and the aromatic vinyl compound are as described above. However, the method for producing the resin composition of this embodiment may involve, for example, blending a maleimide resin having one or more N-substituted maleimide groups, an aromatic vinyl compound, and a thermoplastic resin in an unreacted state. In this case as well, when the mixture is subsequently heat-cured, the maleimide resin having one or more N-substituted maleimide groups and the aromatic vinyl compound react, and a structure corresponding to (A) modified maleimide resin is formed during the curing process, thereby obtaining the same effects as the resin composition of this embodiment. In the method for producing the resin composition of this embodiment, components (B) to (E) and other components that can be contained in the resin composition of this embodiment may be incorporated. Preferred embodiments of these components are as described in the description of the resin composition of this embodiment.

[0132] [Prepreg] The prepreg of this embodiment is a prepreg containing the resin composition of this embodiment or a semi-cured product of the resin composition. The prepreg of this embodiment, for example, contains the resin composition of this embodiment or a semi-cured product of the resin composition and a sheet-like fibrous substrate.

[0133] As the sheet-like fibrous substrate contained in the prepreg of this embodiment, for example, a known sheet-like fibrous substrate used in laminates for various electrical insulating materials can be used. Examples of materials for sheet-like fiber substrates include inorganic fibers such as E-glass, D-glass, S-glass, and Q-glass; organic fibers such as polyimide, polyester, and tetrafluoroethylene; and mixtures thereof. These sheet-like fiber substrates can take the form of woven fabrics, nonwoven fabrics, rawhide, chopped strand mats, and surfacing mats, for example.

[0134] The prepreg of this embodiment can be manufactured, for example, by impregnating or coating a sheet-like fibrous substrate with the resin composition of this embodiment, and then B-staged by heat drying. The temperature and time for heating and drying are not particularly limited, but from the viewpoint of productivity and moderately B-staging the resin composition of this embodiment, they can be, for example, 50 to 200°C and 1 to 30 minutes.

[0135] The solid content concentration derived from the resin composition in the prepreg of this embodiment is not particularly limited, but from the viewpoint of obtaining better moldability when it is made into a laminate, it is preferably 20 to 90% by mass, more preferably 25 to 80% by mass, and even more preferably 30 to 75% by mass.

[0136] [Resin film] The resin film of this embodiment is a resin film containing the resin composition of this embodiment or a semi-cured product of the resin composition. The resin film of this embodiment can be manufactured, for example, by applying the resin composition of this embodiment, i.e., a resin varnish containing an organic solvent, to a support and then heating and drying it. Examples of support materials include plastic film, metal foil, and release paper. The temperature and time for heating and drying are not particularly limited, but from the viewpoint of productivity and moderately B-staging the resin composition of this embodiment, they can be set to 50-200°C and 1-30 minutes.

[0137] The resin film of this embodiment is preferably used to form an insulating layer when manufacturing a printed circuit board.

[0138] [Laminated board] The laminate of this embodiment is a laminate having a cured product of the resin composition of this embodiment or a cured product of a prepreg, and a metal foil. Laminates containing metal foil are sometimes referred to as metal-clad laminates.

[0139] The metal used in the metal foil is not particularly limited and includes, for example, copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, and alloys containing one or more of these metallic elements.

[0140] The laminate of this embodiment can be manufactured, for example, by placing metal foil on one or both sides of the prepreg of this embodiment and then heat-pressure molding it. Typically, this heat-pressure molding process is used to cure the B-staged prepreg, thereby obtaining the laminate of this embodiment. When performing heat and pressure molding, one prepreg sheet may be used, or two or more prepreg sheets may be laminated together. For heat and pressure molding, for example, multi-stage presses, multi-stage vacuum presses, continuous molding machines, autoclave molding machines, etc., can be used. The conditions for heat-pressure molding are not particularly limited, but for example, the temperature can be 100-300°C, the time 10-300 minutes, and the pressure 1.5-5 MPa.

[0141] [Printed wiring board] The printed circuit board of this embodiment is a printed circuit board having one or more selected from the group consisting of a cured product of the resin composition of this embodiment, a cured product of the prepreg of this embodiment, and a laminate of this embodiment. The printed circuit board of this embodiment can be manufactured by forming conductor circuits on one or more materials selected from the group consisting of, for example, a cured prepreg of this embodiment, a cured resin film of this embodiment, and a laminate, using a known method. Furthermore, a multilayer printed circuit board can be manufactured by performing a multilayer bonding process as needed. Conductor circuits can be formed by, for example, drilling holes, metal plating, etching metal foil, etc., as appropriate.

[0142] [Semiconductor Packages] The semiconductor package of this embodiment is a semiconductor package having the printed circuit board of this embodiment and semiconductor elements. The semiconductor package of this embodiment can be manufactured, for example, by mounting semiconductor elements, memory, etc., on the printed circuit board of this embodiment using a known method. [Examples]

[0143] The embodiment will be described in detail below with reference to examples. However, this embodiment is not limited to the following examples.

[0144] In each example, the number-average molecular weight (Mn) was measured using the following procedure. (Method for measuring number-average molecular weight (Mn)) The number-average molecular weight (Mn) was calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Type; A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation, trade name]. The GPC measurement conditions are shown below. Equipment: High-speed GPC equipment HLC-8320GPC Detector: UV-8320 ultraviolet absorption detector [manufactured by Tosoh Corporation] Columns: Guard column; TSK Guardcolumn SuperHZ-L+ column; TSKgel SuperHZM-N+ TSKgel SuperHZM-M+ TSKgel SuperH-RC (all manufactured by Tosoh Corporation, product names) Column sizes: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 5 mL Injection volume: 25μL Flow rate: 1.00mL / min Measurement temperature: 40℃

[0145] [Manufacturing of Modified Maleimide Resin] Manufacturing Examples 1-4 In a 2 L glass flask container equipped with a thermometer, reflux condenser, and stirring device, each component listed in Table 1 was mixed according to the proportions listed in Table 1. The mixture was stirred at 100°C for 2 hours under a nitrogen atmosphere to obtain a modified maleimide resin solution with a solid content of 50% by mass. Table 1 shows the number-average molecular weight (Mn) of the modified maleimide resin.

[0146] [Table 1] * "MIR-3000" refers to biphenylaralkyl maleimide (manufactured by Nippon Kayaku Co., Ltd., product name "MIR-3000").

[0147] [Production of Polyphenylene Ether Derivative] Production Example 5 Into a 2 L glass flask equipped with a thermometer, a reflux condenser, and a stirrer and capable of heating and cooling, toluene, the raw material polyphenylene ether "Zylon (registered trademark) S203A" (trade name, manufactured by Asahi Kasei Corporation, number average molecular weight (Mn): 12,000), and an allyl group-containing compound represented by the following general formula (B-11) were charged and dissolved while stirring at 90 to 100 °C. The compounding amount of the allyl group-containing compound was such that the hydroxyl equivalent derived from the allyl group-containing compound was 6 (equivalent ratio) with respect to the hydroxyl equivalent of the raw material polyphenylene ether. The amount of toluene used was such that the reaction concentration became 35% by mass.

[0148] [Chemical Formula] (In the formula, X B2 is a divalent organic group and is described in the same manner as X B2 in the above general formula (B-6).)

[0149] After visually confirming that the above allyl group-containing compound had dissolved, 2 parts by mass of t-butylperoxyisopropyl monocarbonate and 0.11 parts by mass of manganese octylate were added per 100 parts by mass of the raw material polyphenylene ether, and a redistribution reaction was carried out at a solution temperature of 90 to 100 °C for 6 hours, followed by cooling to 40 °C to obtain a polyphenylene ether derivative having an allyl group at the molecular end. When a small amount of this reaction solution was taken out and subjected to GPC measurement, the double peak derived from the allyl group-containing compound became a single peak, and the number average molecular weight (Mn) of the polyphenylene ether derivative was 4,200.

[0150] [Production of Resin Composition] Examples 1 to 4, Comparative Example 1 Each component described in Table 2 was blended with toluene according to the blending amounts described in Table 2, and stirred and mixed while heating at 25°C or while heating at 50 to 80°C to prepare a resin composition having a solid content concentration of about 50% by mass. In Table 2, the unit of the blending amount of each component is parts by mass, and in the case of a solution, it means parts by mass in terms of solid content. Further, the component (A) was blended as the reaction solution obtained in each production example as it was, and the blending amounts described in Table 2 were the total amounts of the maleimide resin having one or more N-substituted maleimide groups and the aromatic vinyl compound used in each production example.

[0151] [Production of Resin Film and Resin Plate with Double-sided Copper Foil] The resin composition obtained in each example was applied to a PET film with a thickness of 38 μm (manufactured by Teijin Limited, trade name: G2-38), and then heat-dried at 170°C for 5 minutes to produce a resin film in a B-stage state. After peeling this resin film from the PET film, it was pulverized to obtain a resin powder in a B-stage state, and was put into a Teflon (registered trademark) sheet die-cut to a size of 1 mm in thickness × 50 mm in length × 35 mm in width. Next, a rope-profile copper foil with a thickness of 18 μm (manufactured by Mitsui Mining & Smelting Co., Ltd., trade name: 3EC-VLP-18) was placed above and below the Teflon (registered trademark) sheet into which the resin powder was put to obtain a laminate before heat-press molding. The rope-profile copper foil was placed with the M side facing the resin powder side. Subsequently, the laminate was heat-press molded under the conditions of a temperature of 230°C, a pressure of 2.0 MPa, and a time of 120 minutes to mold and cure the resin powder into a resin plate, thereby producing a resin plate with double-sided copper foil. The thickness of the resin plate portion of the obtained resin plate with double-sided copper foil was 1 mm.

[0152] [Evaluation Method and Measurement Method] Using the resin plates with double-sided copper foil obtained in the above Examples and Comparative Examples, each measurement and evaluation was performed according to the following method. The results are shown in Table 2.

[0153] (Measurement Method of Relative Dielectric Constant and Dielectric Dissipation Factor) In each example, the double-sided copper foil-covered resin plates were immersed in a 10% by mass solution of ammonium persulfate (manufactured by Mitsubishi Gas Chemical Company, Inc.), a copper etching solution, to remove the copper foil from both sides and prepare 2 mm × 50 mm test specimens. Subsequently, the relative permittivity (Dk) and dielectric loss tangent (Df) of the test specimens were measured at 10 GHz in an ambient temperature of 25°C, in accordance with the cavity resonator perturbation method.

[0154] (Method for measuring thermal expansion coefficient and glass transition temperature) In each example, the copper foil on both sides of the double-sided copper-foiled resin plate was removed by etching to prepare a 5mm square test specimen. Then, using a thermomechanical measuring device (TMA) (manufactured by T.A. Instruments Japan Co., Ltd., product name: Q400), the thermal expansion coefficient and glass transition temperature of the above test specimen were measured in accordance with the IPC (The Institute for Interconnecting and Packaging Electronic Circuits) standard. The thermal expansion coefficient was the thermal expansion coefficient in the thickness direction of the resin plate, and was taken as the average thermal expansion coefficient over a temperature range of 30 to 120°C.

[0155] (Measurement of copper foil peel strength) Test specimens were prepared by etching the copper foil from the double-sided copper foil-coated resin plates obtained in each example into 3mm wide straight lines. The formed straight lines of copper foil were mounted on a small benchtop testing machine (manufactured by Shimadzu Corporation, product name "EZ-TEST"), and the copper foil peel strength was measured at room temperature (25°C) by peeling it off in a 90° direction, in accordance with JIS C 6481:1996. The pulling speed when peeling the copper foil was set to 50mm / min.

[0156] [Table 2]

[0157] The materials listed in Table 2 are as follows: [(A) component] • Modified maleimide resins 1-4: Modified maleimide resins produced in manufacturing examples 1-4

[0158] [(A') component] • Unmodified maleimide resin: Biphenyl aralkyl type maleimide (manufactured by Nippon Kayaku Co., Ltd., product name "MIR-3000")

[0159] [(B1) component] • Polyphenylene ether derivative: Polyphenylene ether derivative prepared in Production Example 5

[0160] [(B2) component] • SEBS: Hydrogenated styrene thermoplastic elastomer (SEBS), manufactured by Kraton Polymers Japan Co., Ltd., product name "Kraton (registered trademark) G1726", styrene content: 30% by mass

[0161] [(C) component] • Butadiene-styrene copolymer with 1,2-vinyl groups: Butadiene-styrene copolymer, manufactured by Cray Valley, trade name "Ricon257", styrene / butadiene content ratio = 35 / 65 (by mass), proportion of structural units with 1,2-vinyl groups among all structural units derived from butadiene is 70% by mass

[0162] [(E) component] • Isocyanate mask imidazole: Manufactured by Daiichi Kogyo Seiyaku Co., Ltd., product name "G-8009L"

[0163] As is clear from the results shown in Table 2, the cured products of the resin compositions obtained in Examples 1 to 4 of this embodiment exhibit excellent dielectric properties and low thermal expansion. On the other hand, the cured product of the resin composition of Comparative Example 1 was inferior in dielectric properties and low thermal expansion. [Industrial applicability]

[0164] Because the cured products made from the resin composition of this embodiment exhibit excellent dielectric properties and low thermal expansion, prepregs, laminates, printed circuit boards, semiconductor packages, etc. obtained using this resin composition are particularly suitable for electronic component applications that handle high-frequency signals.

Claims

1. (A) A resin comprising a structural unit derived from a maleimide resin having one or more N-substituted maleimide groups, and a structural unit derived from an aromatic vinyl compound, (B) Thermoplastic resin and It contains, The maleimide resin having one or more N-substituted maleimide groups is an aromatic maleimide resin having two or more N-substituted maleimide groups. The aromatic vinyl compound is an α-methylstyrene dimer. The resin composition wherein the (B) thermoplastic resin contains a polyphenylene ether resin having an ethylenically unsaturated bond-containing group and a styrene elastomer.

2. Furthermore, the resin composition according to claim 1, further comprising (C) a crosslinking agent having two or more ethylenically unsaturated bonds.

3. The resin composition according to claim 2, wherein the (C) crosslinking agent having two or more ethylenically unsaturated bonds is a butadiene-styrene copolymer having two or more 1,2-vinyl groups.

4. The resin composition according to any one of claims 1 to 3, wherein the number average molecular weight (Mn) of the resin comprising (A) a structural unit derived from a maleimide resin having one or more N-substituted maleimide groups and a structural unit derived from an aromatic vinyl compound is 400 to 5,000.

5. The resin composition according to any one of claims 1 to 4, wherein the content of the structural units derived from the aromatic vinyl compound in the resin comprising the (A) structural units derived from a maleimide resin having one or more N-substituted maleimide groups and the structural units derived from an aromatic vinyl compound is 1 to 70% by mass.

6. The resin composition according to any one of claims 1 to 5, wherein the aromatic maleimide resin having two or more N-substituted maleimide groups is a biphenyl aralkyl type maleimide resin.

7. The resin composition according to any one of claims 1 to 6, wherein the ethylenically unsaturated bond-containing group of the polyphenylene ether resin is an allyl group.

8. The resin composition according to any one of claims 1 to 7, further comprising (D) an inorganic filler.

9. The resin composition according to any one of claims 1 to 8, further comprising (E) a curing accelerator.

10. The resin composition according to claim 9, wherein the curing accelerator (E) is one or more selected from the group consisting of isocyanate mask imidazole compounds and organic peroxides.

11. A prepreg containing the resin composition described in any one of claims 1 to 10 or a semi-cured product of the resin composition.

12. A laminate having a cured resin composition according to any one of claims 1 to 10 or a cured prepreg according to claim 11, and a metal foil.

13. A resin film containing the resin composition according to any one of claims 1 to 10 or a semi-cured product of the resin composition.

14. A printed circuit board having one or more selected from the group consisting of a cured resin composition according to any one of claims 1 to 10, a cured prepreg according to claim 11, and a laminate according to claim 12.

15. A semiconductor package having a printed circuit board according to claim 14 and a semiconductor element.

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