Maleimide resin compositions, prepregs, resin films, laminates, printed circuit boards, and semiconductor packages

Abstract

Provided are a maleimide resin composition, a prepreg obtained using the maleimide resin composition, a resin film, a laminated board, a printed wiring board, and a semiconductor package, the maleimide resin composition containing (A) one or more selected from the group consisting of a maleimide compound having two or more N-substituted maleimide groups and a derivative thereof, (B) a modified conjugated diene polymer, and (C) a thermoplastic elastomer other than component (B), and component (B) being obtained by modifying a conjugated diene polymer (b1) having a vinyl group in a side chain thereof with a maleimide compound (b2) having two or more N-substituted maleimide groups.

Description

[Technical Field]

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

[0002] Mobile communication devices such as mobile phones, their base station equipment, servers, routers and other network infrastructure equipment, and large computers are all experiencing increasing signal speeds and capacities year after year. Consequently, printed circuit boards used in these electronic devices require high-frequency compatibility, demanding substrate materials with excellent dielectric properties in the high-frequency range to reduce transmission loss. Dielectric properties refer to low dielectric constant and low dielectric loss tangent; hereafter, dielectric properties in the high-frequency range may be referred to as high-frequency properties. In recent years, in addition to the electronic devices mentioned above, new systems handling high-frequency radio signals are being put into practical use or are planned for practical use in ITS fields such as automobiles and transportation systems, as well as in indoor short-range communication fields. It is expected that low transmission loss substrate materials will be even more in demand for printed circuit boards mounted on these devices in the future.

[0003] Printed circuit boards are required to have sufficient heat resistance and low thermal expansion to withstand their operating environment. Therefore, resins with excellent mechanical properties, such as maleimide compounds, are used. However, because these resins have polar groups, improvements in high-frequency characteristics are needed. Therefore, thermoplastic polymers with excellent high-frequency properties are used in printed circuit boards where low transmission loss is required. For example, polyphenylene ether and polybutadiene are effective thermoplastic polymers for reducing dielectric loss tangent. However, these thermoplastic polymers have poor heat resistance and a high coefficient of thermal expansion compared to metals, resulting in inferior mechanical properties. To provide a substrate material with excellent mechanical properties and low transmission loss, it is desirable to use a resin composition that possesses both of these properties. However, because thermoplastic polymers have poor compatibility with other resins, separation of the thermoplastic polymer from other components occurs in the resin composition, making it difficult to obtain a resin composition with good handling properties when using thermoplastic polymers.

[0004] Under these circumstances, methods for modifying thermoplastic polymers are being investigated as a way to improve the compatibility of thermoplastic polymers. Patent Document 1 discloses a thermosetting resin composition that has a low dielectric loss tangent, low thermal expansion, and excellent wiring embedding and flatness properties, and aims to provide a thermosetting resin composition that has an inorganic filler (A), a polyimide compound (B) having structural units derived from a maleimide compound (a1) having at least two N-substituted maleimide groups and structural units derived from a diamine compound (a2), and incorporates a polybutadiene elastomer modified with an acid anhydride. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-012747 [Overview of the project] [Problems that the invention aims to solve]

[0006] The resin composition described in Patent Document 1 has achieved excellent dielectric properties in the high-frequency band by improving the compatibility of the thermoplastic polymer. However, in recent years, substrate materials have been required to be applied to fifth-generation mobile communication system (commonly known as 5G) antennas that use radio waves in the frequency band above 6 GHz and millimeter-wave radars that use radio waves in the frequency band of 30 to 300 GHz. For this purpose, it is necessary to develop a resin composition with further improved dielectric properties in the 10 GHz band and above. However, with the technology of Patent Document 1, it has been difficult to achieve further improvement in dielectric properties while maintaining good properties.

[0007] In view of the current situation, this embodiment aims to provide a maleimide resin composition that contains a thermoplastic polymer, is easy to handle, has good heat resistance and low thermal expansion, and exhibits excellent dielectric properties in the high frequency band of 10 GHz or higher, as well as a prepreg, resin film, laminate, printed circuit board, and semiconductor package using the maleimide resin composition. [Means for solving the problem]

[0008] As a result of diligent research by the present inventors, we have found that the above-mentioned problems can be solved by the following embodiment. One aspect of this embodiment is as follows [1] to

[15] . [1](A)One or more selected from the group consisting of maleimide compounds having one or more N-substituted maleimide groups and derivatives thereof, (B) Modified conjugated diene polymer and (C) A thermoplastic elastomer other than the component in (B) above, A maleimide resin composition in which component (B) is obtained by modifying a conjugated diene polymer having a vinyl group in its side chain (b1) with a maleimide compound having two or more N-substituted maleimide groups (b2). [2] The maleimide resin composition according to [1], wherein component (B) has a substituent (x) in its side chain formed by the reaction of a vinyl group of component (b1) and an N-substituted maleimide group of component (b2). [3] The maleimide resin composition according to [2] above, wherein the substituent (x) is a group containing a structure represented by the following general formula (B-11) or (B-12) as a structure derived from component (b2). [ka] (In the formula, X B1 is a divalent organic group, * B1 This is the site where component (b1) bonds to a carbon atom derived from the vinyl group in its side chain. B2 (This is a site that bonds to other atoms.) [4] The maleimide resin composition according to any one of [1] to [3] above, wherein the number average molecular weight of component (B) is 700 to 6,000. [5] The maleimide resin composition according to any one of [1] to [4] above, wherein the (b1) component is polybutadiene having a 1,2-vinyl group. [6] The maleimide resin composition according to [5] above, wherein the content of structural units having 1,2-vinyl groups is 50 mol% or more relative to the total structural units derived from butadiene constituting the polybutadiene having 1,2-vinyl groups. [7] The maleimide resin composition according to any one of [1] to [6] above, wherein the (b2) component is at least one selected from the group consisting of an aromatic maleimide compound having one N-substituted maleimide group in the molecule, an aromatic bismaleimide compound having two N-substituted maleimide groups in the molecule, and an aromatic polymaleimide compound having three or more N-substituted maleimide groups in the molecule. [8] The maleimide resin composition according to any one of [1] to [7] above, wherein the content ratio of component (A) to component (B) [(A) / (B)] is greater than 1.0 by mass. [9] The maleimide resin composition according to any one of [1] to [8] above, wherein, with respect to 100 parts by mass of the total sum of components (A) to (C), the content of component (A) is 10 to 90 parts by mass, the content of component (B) is 1 to 50 parts by mass, and the content of component (C) is 5 to 60 parts by mass.

[10] A prepreg containing the maleimide resin composition described in any of [1] to [9] above or a semi-cured product of the maleimide resin composition.

[11] A resin film containing the maleimide resin composition described in any of [1] to [9] above or a semi-cured product of the maleimide resin composition.

[12] A laminate having a cured maleimide resin composition according to any of [1] to [9] above or a cured prepreg according to

[10] above, and a metal foil.

[13] A printed circuit board having one or more selected from the group consisting of a cured maleimide resin composition according to any of [1] to [9] above, a cured prepreg according to

[10] above, and a laminate according to

[12] above.

[14] A semiconductor package having the printed circuit board described in

[13] above and a semiconductor element.

[15] A method for producing a maleimide resin composition according to any of [1] to [9] above, comprising steps 1 and 2 below. Step 1: A step to obtain (B) a modified conjugated diene polymer by reacting (b1) a conjugated diene polymer having vinyl groups in its side chains with (b2) a maleimide compound having two or more N-substituted maleimide groups. Step 2: A step of mixing (A) one or more maleimide compounds selected from the group consisting of maleimide compounds having one or more N-substituted maleimide groups and derivatives thereof, (B) a modified conjugated diene polymer, and (C) a thermoplastic elastomer other than the component in (B). [Effects of the Invention]

[0009] According to this embodiment, it is possible to provide a maleimide resin composition that exhibits excellent dielectric properties in the high frequency band of 10 GHz or higher while having good heat resistance and low thermal expansion, as well as a prepreg, resin film, laminate, printed circuit board, and semiconductor package using the maleimide resin composition. [Modes for carrying out the invention]

[0010] In the numerical ranges described herein, the upper or lower limits of those ranges may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of a numerical range can be arbitrarily combined with the lower or upper limits of other numerical ranges. In the notation "AA~BB" for a numerical range, the numbers AA and BB at both ends are included in the range as the lower and upper limits, respectively. In this specification, for example, the phrase "10 or more" means 10 and numbers greater than 10, and the same applies when the numbers are different. Similarly, for example, the phrase "10 or less" means 10 and numbers less than 10, and the same applies when the numbers are different. Furthermore, 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 composition means the total amount of multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component are present in the composition. In this specification, "resin components" are defined as all components of the resin composition, excluding inorganic compounds such as the inorganic filler (D) described later. In this specification, "solids" refers to components in a resin composition other than volatile substances such as water and organic solvents. In other words, the solids include substances that are liquid, syrup-like, or waxy at around 25°C, and do not necessarily mean that they are solid. The expression "contains ~~" as used herein is sometimes expressed as "containing ~~," but in this specification, both are synonymous. In other words, both expressions include the meaning of simply containing ~~ and containing the components described in ~~ in a reacted state. Embodiments that combine any combination of the information described herein are also included.

[0011] [Maleimide resin composition] The maleimide resin composition of this embodiment [hereinafter sometimes simply referred to as the resin composition] is as follows: (A) One or more selected from the group consisting of maleimide compounds having one or more N-substituted maleimide groups and their derivatives [hereinafter, this may be simply referred to as maleimide compound (A) or component (A)], (B) Modified conjugated diene polymer [hereinafter sometimes abbreviated as modified conjugated diene polymer (B) or component (B)] and (C) A thermoplastic elastomer other than the component in (B) above [hereinafter, this may be abbreviated as other thermoplastic elastomer (C) or component (C)], A maleimide resin composition in which component (B) is obtained by modifying a conjugated diene polymer having vinyl groups in its side chains [hereinafter sometimes simply referred to as diene polymer (b1) or component (b1)] with a maleimide compound having two or more N-substituted maleimide groups [hereinafter sometimes simply referred to as maleimide compound (b2) or component (b2)].

[0012] The reason why the maleimide resin composition of this embodiment exhibits excellent dielectric properties in the high frequency band of 10 GHz or higher, while also possessing good heat resistance and low thermal expansion, and is easy to handle, is not entirely clear, but it is presumed to be as follows. Conjugated diene polymers are effective in reducing dielectric loss tangent because they do not contain polar groups within their molecules. However, conjugated diene polymers have poor compatibility with maleimide compounds, leading to separation and other handling difficulties. On the other hand, introducing oxygen atoms or the like into the conjugated diene polymer to improve this reduces the dielectric loss tangent effect. In contrast, the maleimide resin composition of this embodiment employs a conjugated diene polymer having vinyl groups in its side chains, and by reacting these vinyl groups with a modifying maleimide compound beforehand, the compatibility between the conjugated diene polymer and the maleimide compound and thermoplastic elastomer used as the main component is improved. As a result, the maleimide resin composition of this embodiment has excellent handling properties. Furthermore, the resin composition of this embodiment not only exhibits excellent compatibility, but also superior heat resistance and thermal expansion coefficient, and an unexpectedly reduced dielectric loss tangent. This is presumed to be due to (1) the reduced dielectric loss tangent effect obtained by the compatibility of the conjugated diene polymer with the maleimide compound, (2) the full expression of the mechanical properties derived from the compatible thermoplastic elastomer, and (3) the improved curability of the entire resin composition due to the good reaction of the N-substituted maleimide groups introduced into the conjugated diene polymer by the modifying maleimide compound with the maleimide compound (A) used as the main component thereafter. The following details each component in turn.

[0013] <Maleimide compound (A)> Maleimide compound (A) is one or more selected from the group consisting of maleimide compounds having one or more N-substituted maleimide groups and their derivatives. Examples of the "derivatives of maleimide compounds having one or more N-substituted maleimide groups" mentioned above include addition reaction products of a maleimide compound having one or more N-substituted maleimide groups and an amine compound such as the diamine compound (a2) described later. (A) Component (A) may be used alone or in combination of two or more components.

[0014] As for the maleimide compound (A), from the viewpoint of compatibility with other resins, adhesion to conductors, and dielectric properties, (i) Maleimide compound (a1) having one or more N-substituted maleimide groups [hereinafter sometimes simply referred to as maleimide compound (a1) or component (a1)], and (ii) An aminomaleimide compound having a structural unit derived from maleimide compound (a1) and a structural unit derived from diamine compound (a2) [Hereinafter, this may be abbreviated as aminomaleimide compound (A1) or component (A1)]. It is preferable to select one or more from the group consisting of the following:

[0015] (Maleimide compound (a1)) (a1) Specific examples of the component are not particularly limited as long as they are maleimide compounds having one or more N-substituted maleimide groups, but include aromatic maleimide compounds having one N-substituted maleimide group preferably bonded to an aromatic ring in the molecule, such as N-phenylmaleimide, N-(2-methylphenyl)maleimide, N-(4-methylphenyl)maleimide, N-(2,6-dimethylphenyl)maleimide, N-(2,6-diethylphenyl)maleimide, N-(2-methoxyphenyl)maleimide, N-benzylmaleimide; bis(4-maleimidophenyl)methane, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismale Examples include aromatic bismaleimide compounds having two N-substituted maleimide groups preferably bonded to an aromatic ring within the molecule, such as imides, 4-methyl-1,3-phenylenebismaleimide, m-phenylenebismaleimide, and 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane; aromatic polymaleimide compounds having three or more N-substituted maleimide groups preferably bonded to an aromatic ring within the molecule, such as polyphenylmethanemaleimide and biphenylaralkyl-type maleimide; and aliphatic maleimide compounds such as N-dodecylmaleimide, N-isopropylmaleimide, and N-cyclohexylmaleimide, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, and pyrrolironate binder-type long-chain alkylbismaleimide. Among these, aromatic bismaleimide compounds having two N-substituted maleimide groups in the molecule and aromatic polymaleimide compounds having three or more N-substituted maleimide groups in the molecule are preferred from the viewpoint of compatibility with other resins, adhesion to conductors, heat resistance, low thermal expansion and mechanical properties, aromatic polymaleimide compounds having three or more N-substituted maleimide groups in the molecule are more preferred, aromatic polymaleimide compounds having three or more N-substituted maleimide groups in the molecule are more preferred, and biphenylaralkyl type maleimide is even more preferred. Furthermore, as component (a1), it is particularly preferred to be at least one selected from the group consisting of bis(4-maleimidophenyl)methane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide and biphenylaralkyl type maleimide. (a1) The component may be used alone or in combination of two or more components.

[0016] (a1) A maleimide compound represented by the following general formula (a1-1) is preferred as component (a1).

[0017] [ka] (In the formula, X a1 (This is a divalent organic group.)

[0018] X in the above general formula (a1-1) a1 This is a divalent organic group and corresponds to a residue of component (a1). Note that the residue of component (a1) refers to the structure of the part of component (a1) from which the N-substituted maleimide group has been removed. X a1 Examples of divalent organic groups represented by the following general formulas are (a1-2), (a1-3), (a1-4), (a1-5), or (a1-6).

[0019] [ka] (In the formula, R a1 This refers to an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. p1 is an integer from 0 to 4. * represents a bonding site.

[0020] R a1 Examples of aliphatic hydrocarbon groups having 1 to 5 carbon atoms represented by include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, and n-pentyl group. The aliphatic hydrocarbon group may also be an aliphatic hydrocarbon group having 1 to 3 carbon atoms, or it may be a methyl group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. p1 is an integer between 0 and 4, and for ease of availability, it may also be an integer between 0 and 2, or 0 or 1, or 0. If p1 is an integer greater than or equal to 2, multiple Ra1 They may be the same or different from each other.

[0021]

Chemical formula

[0022] R a2 and R a3 Examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms and the halogen atom represented by are the same as those in the case of R a1 . The aliphatic hydrocarbon group may be an aliphatic hydrocarbon group having 1 to 3 carbon atoms, may be a methyl group or an ethyl group, or may be an ethyl group. X a2 Examples of the alkylene group having 1 to 5 carbon atoms represented by include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylene group, a 1,4-tetramethylene group, a 1,5-pentamethylene group, etc. From the viewpoints of compatibility with other resins, adhesion to conductors, heat resistance, low thermal expansion property, and mechanical properties, the alkylene group may be an alkylene group having 1 to 3 carbon atoms, or may be a methylene group. X a2 Examples of the alkylidene group having 2 to 5 carbon atoms represented by include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group, an isopentylidene group, etc. Among these, from the viewpoints of compatibility with other resins, adhesion to conductors, heat resistance, low thermal expansion property, and mechanical properties, the isopropylidene group may be used. X a2Among the above options, alkylene groups with 1 to 5 carbon atoms and alkylidene groups with 2 to 5 carbon atoms may also be used. p2 and p3 are each an integer between 0 and 4, and from the standpoint of availability, they may both be integers between 0 and 2, or 0 or 2. If p2 or p3 is an integer greater than or equal to 2, multiple R a2 Mutual or R a3 They may be the same or they may be different. Note X a2 The divalent group represented by the general formula (a1-3-1) is as follows:

[0023] [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 The group is an alkylene group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, or a single bond. p4 and p5 are each independently integers from 0 to 4. * indicates a bonding site.

[0024] R a4 and R a5 The aliphatic hydrocarbon group with 1 to 5 carbon atoms represented by R is an aliphatic hydrocarbon group with 1 to 5 carbon atoms, and the halogen atom is R. a1 It is explained in the same way as in the case of this example. X a3 The alkylene group with 1 to 5 carbon atoms and the alkylidene group with 2 to 5 carbon atoms represented by are: a2 Examples include alkylene groups with 1 to 5 carbon atoms and alkylidene groups with 2 to 5 carbon atoms, which are the same as those represented by [the symbol]. X a3 Alternatively, an alkylidene group with 2 to 5 carbon atoms may be selected from the above options. p4 and p5 are each an integer between 0 and 4, and from the standpoint of availability, they may both be integers between 0 and 2, 0 or 1, or 0. If p4 or p5 is an integer of 2 or greater, multiple Ra4 Mutual or R a5 They may be the same or they may be different.

[0025] [ka] (In the formula, p6 is an integer between 0 and 10. * represents a bonding site.)

[0026] p6 may be an integer between 0 and 5, or an integer between 0 and 3, from the standpoint of availability.

[0027] [ka] (In the formula, p7 is an integer between 0 and 5. * represents a bonding site.)

[0028] [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. p8 is an integer from 1 to 8. * represents a bonding site.

[0029] R a6 and R a7 As an example of an aliphatic hydrocarbon group with 1 to 5 carbon atoms represented by R, a1 It is explained in the same way as in the case of this example. p8 is an integer between 1 and 8, and may be an integer between 1 and 3, or it may be 1. If p8 is an integer greater than or equal to 2, then multiple R a6 Mutual or R a7 They may be the same or they may be different.

[0030] (Aminomaleimide compound (A1)) The aminomaleimide compound (A1) is an aminomaleimide compound having a structural unit derived from the maleimide compound (a1) and a structural unit derived from the diamine compound (a2). The (a1) component is preferably a bismaleimide compound having two N-substituted maleimide groups on the aromatic ring in the molecule, and preferably a polymaleimide compound having three or more N-substituted maleimide groups on the aromatic ring in the molecule. More preferably, the aromatic bismaleimide compound having two N-substituted maleimide groups on the aromatic ring in the molecule, and the aromatic polymaleimide compound having three or more N-substituted maleimide groups on the aromatic ring in the molecule, as described in the description of the maleimide compound (a1), are preferred. (A1) Component (A1) may be used alone or in combination of two or more components.

[0031] (a1) Structural units derived from component include one or more selected from the group consisting of groups represented by the following general formulas (a1-7) and groups represented by the following general formula (a1-8).

[0032] [ka] (In the formula, X a1 (where * indicates a divalent organic group, and * indicates a bond position to other structures.)

[0033] X in the above general formulas (a1-7) and (a1-8) a1 The explanation for this is given by X in the general formula (a1-1) above. a1 This is the same as the explanation for [the other topic]. The total content of structural units derived from component (a1) in the aminomaleimide compound (A1) is preferably 5 to 95% by mass, more preferably 30 to 93% by mass, even more preferably 60 to 90% by mass, and particularly preferably 75 to 90% by mass. When the content of structural units derived from component (a1) is within the above range, the dielectric properties in the high frequency band of 10 GHz or higher tend to be better, and good film handling properties tend to be obtained.

[0034] (a2) The component is not particularly limited as long as it is a compound having two amino groups. (a2) Components include 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ketone, 4,4'-diaminobiphenyl, 3,3'-dimethyl- 4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis( 3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,3-bis[1-[4-(4-aminophenoxy)phenyl]-1-methylethyl]benzene, 1,4-bis[1-[4-(4-aminophenoxy)phenyl]-1-methylethyl]benzene, 4,4'-[1,3- Examples include phenylenebis(1-methylethylidene)bisaniline, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 3,3'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, and 9,9-bis(4-aminophenyl)fluorene. (a2) The component may be used alone or in combination of two or more components.

[0035] Among these, as component (a2), 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, and 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline are preferred from the viewpoint of excellent solubility in organic solvents, reactivity with component (a1), and heat resistance. Furthermore, from the viewpoint of excellent dielectric properties and low water absorption, 3,3'-dimethyl-5,5'-diethyl-4,4'-diaminodiphenylmethane is preferred as component (a2). Furthermore, from the viewpoint of excellent mechanical properties such as high adhesion to conductors, elongation, and tensile strength, 2,2-bis[4-(4-aminophenoxy)phenyl]propane is preferred as component (a2). In addition, from the viewpoint of excellent solubility in organic solvents, reactivity during synthesis, heat resistance, and high adhesion to conductors, as well as excellent dielectric properties and low hygroscopicity, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline and 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline are preferred as component (a2).

[0036] (a2) Structural units derived from component include, for example, one or more selected from the group consisting of a group represented by the following general formula (a2-1) and a group represented by the following general formula (a2-2).

[0037] [ka] (In the formula, X a4 (where * indicates a divalent organic group, and * indicates a bond position to other structures.)

[0038] X in the above general formulas (a2-1) and (a2-2) a4 This is a divalent organic group and corresponds to a residue of component (a2). Note that a residue of component (a2) refers to the structure of the part of component (a2) excluding the functional group used for bonding, i.e., the amino group.

[0039] X in the above general formula (a2-1) and the above general formula (a2-2) a4 It is preferable that the group is a divalent group represented by the following general formula (a2-3).

[0040] [ka] (In the formula, R a11 and R a12 Each of these is independently an aliphatic hydrocarbon group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, or a halogen atom. a5 This refers to an alkylene group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, a fluorenylene group, a single bond, or a divalent group represented by the following general formulas (a2-3-1) or (a2-3-2). p9 and p10 are each independently integers from 0 to 4. * represents a bonding site.

[0041] [ka] (In the formula, R a13 and R a14 Each of these is independently an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. a6 These are alkylene groups with 1 to 5 carbon atoms, alkylidene groups with 2 to 5 carbon atoms, m-phenylenediisopropylidene groups, p-phenylenediisopropylidene groups, ether groups, sulfide groups, sulfonyl groups, carbonyloxy groups, keto groups, or single bonds. p11 and p12 are each independent integers between 0 and 4. (* represents a connection point.)

[0042] [ka] (In the formula, R a15 Each of these is independently an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. a7 and Xa8 Each of these is independently an alkylene group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, or a single bond. p13 is an integer from 0 to 4. * indicates a bonding site.

[0043] In the above general formulas (a2-3), (a2-3-1), or (a2-3-2), R a11 , R a12 , R a13 , R a14 and R a15 The aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms represented by is R in the above general formula (a1-2). a1 The same as above can be cited. The aliphatic hydrocarbon group may be an aliphatic hydrocarbon group having 1 to 3 carbon atoms, or it may be a methyl group or an ethyl group. X in the above general formula (a2-3) a5 , X in the above general formula (a2-3-1) a6 Furthermore, X in the above general formula (a2-3-2) a7 and X a8 The alkylene group with 1 to 5 carbon atoms and the alkylidene group with 2 to 5 carbon atoms represented by are X in the general formula (a1-3) above. a2 It is explained in the same way as in the case of this example. In the above general formula (a2-3), p9 and p10 are each an integer between 0 and 4, and from the viewpoint of availability, they may both be integers between 0 and 2, or they may be 0 or 2. If p9 or p10 is an integer greater than or equal to 2, multiple R a11 Mutual or R a12 They may be the same or they may be different. In the above general formula (a2-3-1), p11 and p12 are each an integer between 0 and 4, and from the viewpoint of availability, they may both be integers between 0 and 2, 0 or 1, or 0. If p11 or p12 is an integer of 2 or more, multiple R a13 Mutual or R a14 They may be the same or they may be different. In the above general formula (a2-3-2), p13 is an integer from 0 to 4, and from the viewpoint of availability, it may also be an integer from 0 to 2, or it may be 0. If p13 is an integer of 2 or more, multiple R a15 They may be the same or they may be different.

[0044] The total content of structural units derived from component (a2) in the aminomaleimide compound (A1) is preferably 5 to 95% by mass, more preferably 7 to 70% by mass, even more preferably 10 to 40% by mass, and particularly preferably 10 to 25% by mass. When the total content of structural units derived from component (a2) is within the above range, excellent dielectric properties and better heat resistance, flame retardancy, and glass transition temperature tend to be obtained.

[0045] The ratio of structural units derived from component (a1) to structural units derived from component (a2) in the aminomaleimide compound (A1) is such that the equivalent ratio (Ta2 / Ta1) of the total equivalent amount (Ta2) of groups derived from the -NH2 group of component (a2) (including -NH2) to the total equivalent amount (Ta1) of groups derived from the N-substituted maleimide group of component (a1) (including N-substituted maleimide groups) in the aminomaleimide compound (A1) is preferably 0.05 to 10, more preferably 1 to 5. When the equivalent ratio (Ta2 / Ta1) is within the above range, excellent dielectric properties and better heat resistance, flame retardancy, and glass transition temperature tend to be obtained.

[0046] From the viewpoint of dielectric properties, as well as solubility in organic solvents, high adhesion to conductors, and moldability of resin films, it is preferable that the aminomaleimide compound (A1) contains an aminomaleimide compound represented by the following general formula (a2-4).

[0047] [ka] (In the formula, X a1 and X a4 This is as explained above.

[0048] (Method for producing aminomaleimide compound (A1)) Component (A1) can be produced, for example, by reacting component (a1) and component (a2) in an organic solvent. When reacting component (a1) with component (a2) to produce the aminomaleimide compound (A1), a reaction catalyst may be used as needed. The reaction catalyst is not particularly limited, but examples include acidic catalysts such as p-toluenesulfonic acid; amines such as triethylamine, pyridine, and tributylamine; imidazoles such as methylimidazole and phenylimidazole; and phosphorus-based catalysts such as triphenylphosphine. These may be used individually or in combination of two or more. Furthermore, the amount of reaction catalyst used is not particularly limited, but for example, 0.01 to 5 parts by mass may be used per 100 parts by mass of the total amount of components (a1) and (a2).

[0049] The aminomaleimide compound is obtained by charging components (a1), (a2), and other components as needed in predetermined amounts into a reactor and performing a Michael addition reaction between components (a1) and (a2). The reaction conditions in this step are not particularly limited, but from the viewpoint of workability such as reaction rate and suppression of gelation during the reaction, for example, the reaction temperature is preferably 50 to 160°C and the reaction time is preferably 1 to 10 hours. Furthermore, in this process, the solid content concentration of the reaction raw materials and the viscosity of the solution can be adjusted by adding or concentrating the organic solvent. The solid content concentration of the reaction raw materials is not particularly limited, but is preferably 10 to 90% by mass, more preferably 20 to 80% by mass. When the solid content concentration of the reaction raw materials is 10% by mass or more, the reaction rate does not become too slow, which tends to be advantageous in terms of manufacturing costs. Also, when the solid content concentration of the reaction raw materials is 90% by mass or less, better solubility is obtained, stirring efficiency is improved, and gelation tends to be less likely.

[0050] The number-average molecular weight of the aminomaleimide compound (A1) is not particularly limited, but is preferably 400 to 10,000, more preferably 500 to 5,000, even more preferably 600 to 2,000, and most preferably 700 to 1,500. In this specification, the number-average molecular weight refers to the value measured in polystyrene equivalent by gel permeation chromatography (GPC), which can be specifically measured by the method described in the examples.

[0051] <Modified conjugated diene polymer (B)> Modified conjugated diene polymer (B) is obtained by modifying a conjugated diene polymer having vinyl groups in its side chains (b1) with a maleimide compound having two or more N-substituted maleimide groups (b2). (B) Component (B) may be used alone or in combination of two or more components.

[0052] ((b1) Conjugated diene polymer having vinyl groups in its side chains) (b1) Component is not particularly limited as long as it is a conjugated diene polymer having vinyl groups in its side chains, but it is preferably a conjugated diene polymer having multiple vinyl groups in its side chains. (b1) The number of vinyl groups in one molecule of component is preferably 3 or more, more preferably 5 or more, and even more preferably 10 or more, from the viewpoint of dielectric properties and heat resistance. (b1) The component may be used alone or in combination of two or more components.

[0053] In this specification, "conjugated diene polymer" means a polymer of a conjugated diene compound. Examples of conjugated diene compounds include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, and 1,3-hexadiene. The conjugated diene polymer may be a polymer of one conjugated diene compound, or it may be a polymer of two or more conjugated diene compounds. Furthermore, the conjugated diene polymer may be obtained by copolymerizing one or more conjugated diene compounds with one or more monomers other than conjugated diene compounds. In this case, the polymerization method is not particularly limited and may be random polymerization, block polymerization, or graft polymerization.

[0054] (b1) Specific examples of component include polybutadiene having 1,2-vinyl groups, butadiene-styrene copolymer having 1,2-vinyl groups, and polyisoprene having 1,2-vinyl groups. Among these, polybutadiene having 1,2-vinyl groups and butadiene-styrene copolymer having 1,2-vinyl groups are preferred from the viewpoint of dielectric properties and heat resistance, and polybutadiene having 1,2-vinyl groups is more preferred. Furthermore, as polybutadiene having 1,2-vinyl groups, butadiene homopolymer having 1,2-vinyl groups is preferred. (b1) The 1,2-vinyl group derived from butadiene in component (b1) is the vinyl group contained in the butadiene-derived structural unit represented by the following formula (b1-1).

[0055] [ka]

[0056] (b1) When component is polybutadiene having 1,2-vinyl groups, the content of structural units having 1,2-vinyl groups (structural units represented by the general formula (b1-1) above) relative to the total structural units derived from butadiene constituting the polybutadiene [hereinafter sometimes abbreviated as vinyl group content] is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, particularly preferably 80 mol% or more, and most preferably 85 mol% or more, from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion and heat resistance. Furthermore, there is no particular upper limit to the vinyl group content, and it may be 100 mol% or less. From a similar viewpoint, the polybutadiene having a 1,2-vinyl group is preferably a 1,2-polybutadiene homopolymer.

[0057] (b1) The number-average molecular weight of component (b1) is preferably 400 to 4,000, more preferably 500 to 3,500, but may also be 2,000 to 3,500, 600 to 2,000, or 700 to 1,500, from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion, and heat resistance.

[0058] ((b2) Maleimide compounds having two or more N-substituted maleimide groups) (b2) Component can be any maleimide compound having two or more N-substituted maleimide groups, and any of the maleimide compounds listed as (A) above can be used. (b2) The component may be used alone or in combination of two or more components.

[0059] Among these, as component (b2), from the viewpoint of solubility in organic solvents and suppression of gelation during the reaction, as well as compatibility with other resins of the obtained component (B), dielectric properties, low thermal expansion and heat resistance, at least one selected from the group consisting of aromatic bismaleimide compounds having preferably two N-substituted maleimide groups on the aromatic ring in the molecule and aromatic polymaleimide compounds having preferably three or more N-substituted maleimide groups on the aromatic ring in the molecule, as described in the description of maleimide compound (a1), more preferably aromatic bismaleimide compounds having preferably two N-substituted maleimide groups on the aromatic ring in the molecule, and even more preferably maleimide compounds represented by the general formula (a1-1). In particular, from the same viewpoint as above, component (b2) is preferably an aromatic maleimide compound substituted with an aliphatic hydrocarbon group, and more preferably a compound represented by the following general formula (b2-1).

[0060] [ka] (In the formula, R b1 and R b2 Each of these is an aliphatic hydrocarbon group having 1 to 5 carbon atoms. b1q1 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 group represented by the following general formula (b2-1-1). q1 and q2 are each an integer between 0 and 4.

[0061] R b1 and R b2 Examples of aliphatic hydrocarbon groups having 1 to 5 carbon atoms that can be represented include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. From the viewpoint of compatibility with other resins and suppression of gelation during the reaction, aliphatic hydrocarbon groups having 1 to 3 carbon atoms are preferred, alkyl groups having 1 to 3 carbon atoms are more preferred, and ethyl and methyl groups are even more preferred.

[0062] X b1 Examples of alkylene groups having 1 to 5 carbon atoms represented by include methylene groups, 1,2-dimethylene groups, 1,3-trimethylene groups, 1,4-tetramethylene groups, and 1,5-pentamethylene groups. A alkylene group having 1 to 3 carbon atoms is preferred, and a methylene group is more preferred. X b1 Examples of alkylidene groups with 2 to 5 carbon atoms represented by include ethylidene, propyridene, isopropylidene, butylidene, isobutylidene, pentylidene, and isopentylidene. q1 and q2 are each an integer between 0 and 4, independently of each other. From the viewpoint of availability, compatibility with other resins, and suppression of gelation during the reaction, both q1 and q2 are preferably integers between 0 and 2, and may be 0. From the viewpoint of compatibility with other resins and suppression of gelation during the reaction, it is preferable that q1 + q2 is an integer of 1 or more, more preferably that q1 and q2 are each 1 or 2, and even more preferably that they are each 2. When q1 or q2 is an integer of 2 or more, multiple R b1 Mutual or R b2 They may be the same or they may be different. Note X b1The divalent group represented by the general formula (b2-1-1) represented is as follows.

[0063] [Chemical formula] (In the formula, R b3 and R b4 are each independently an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. X b2 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. q3 and q4 are each independently an integer of 0 to 4. * represents a bonding site.)

[0064] R b3 and R b4 The aliphatic hydrocarbon group having 1 to 5 carbon atoms and the halogen atom represented by are described in the same manner as in the case of R b1 . X b2 Examples of the alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented by are the same as those of the alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented by X b1 . q3 and q4 are each independently an integer of 0 to 4, and from the viewpoint of availability, each may be an integer of 0 to 2, may be 0 or 1, or may be 0. When q3 or q4 is an integer of 2 or more, a plurality of R b3 may be the same as or different from each other, and a plurality of R b4 may be the same as or different from each other.

[0065] Examples of compounds represented by the above general formula (b2-1) include 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide and 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane. Among these, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide is preferred from the viewpoint of solubility in organic solvents, suppression of gelation during the reaction, compatibility with other resins of the obtained (B) component, dielectric properties, low thermal expansion, and heat resistance. In addition to the compound represented by the general formula (b2-1) above, other preferred components for (b2) include 4-methyl-1,3-phenylenebismaleimide and 4,4'-diphenylmethanebismaleimide.

[0066] (Reaction conditions) The method for reacting component (b1) and component (b2) is not particularly limited. For example, component (B) can be obtained by charging predetermined amounts of component (b1), component (b2), reaction catalyst, and organic solvent into a reaction vessel and reacting them while heating, maintaining temperature, stirring, etc., as necessary. The reaction conditions in this step can be appropriately adjusted depending on the type of raw materials used, but from the viewpoint of workability and suppression of gelation during the reaction, the reaction temperature is preferably 70 to 120°C, more preferably 80 to 110°C, and even more preferably 85 to 105°C, and the reaction time is preferably 0.5 to 15 hours, more preferably 1 to 10 hours, and even more preferably 3 to 7 hours.

[0067] The organic solvent used in the above reaction is not particularly limited, but examples include alcohols such as methanol, ethanol, butanol, butyl cellosolve, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and mesitylene; esters such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate; and nitrogen-containing compounds such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. These may be used individually or in combination of two or more. Among these, toluene is preferred from the viewpoint of resin solubility.

[0068] When the above reaction is carried out in an organic solvent, the total content of component (b1) and component (b2) 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 is 10% by mass or more, the reaction rate does not become too slow, which tends to be more advantageous in terms of manufacturing costs. Furthermore, when the total content is 70% by mass or less, better solubility is obtained, the solution viscosity is low, the stirring efficiency is good, and gelation tends to be further suppressed.

[0069] As the reaction catalyst, those listed as curing accelerators (F) described later can be used. Among these, organic peroxides are preferred, and α,α'-bis(t-butylperoxy)diisopropylbenzene is more preferred, from the viewpoint of suppressing gelation during the reaction while obtaining sufficient reactivity. The reaction catalyst may be used alone or in combination of two or more types. The amount of reaction catalyst used is not particularly limited, but is preferably 0.01 to 1.2 parts by mass, more preferably 0.03 to 1.0 parts by mass, and even more preferably 0.05 to 0.8 parts by mass, per 100 parts by mass of the total amount of components (b1) and (b2).

[0070] When carrying out the above reaction, the blending amounts of the component (b1) and the component (b2) are such that, from the viewpoints of the compatibility of the resulting component (B) with other resins and the suppression of gelation during the reaction, the number of moles (M v ) of the side-chain vinyl groups possessed by the component (b1) relative to 、 the number of moles (M m ) of the N-substituted maleimide groups possessed by the component (b2) is preferably in the range of 0.01 to 0.5, more preferably 0.02 to 0.4, and even more preferably 0.04 to 0.3 in terms of the ratio (M m / M v ).

[0071] By the above reaction, at least a part of the vinyl groups in the side chain of the component (b1) reacts with the N-substituted maleimide groups possessed by the component (b2), and the component (B) is produced. The resulting component (B) has, in the side chain, a substituent (x) formed by the reaction of the vinyl group possessed by the component (b1) and the N-substituted maleimide group possessed by the component (b2). From the viewpoints of compatibility with other resins, dielectric properties, low thermal expansion properties, and heat resistance, the substituent (x) is preferably a group containing a structure represented by the following general formula (B-11) or (B-12) as a structure derived from the component (b2).

[0072]

Chemical formula

[0073] Regarding the description of X B1 in the above general formulas (B-11) and (B-12), it is the same as the description of X a1 in the above general formula (a1-1). * B2This is a site that bonds to other atoms and is not particularly limited, but for example, it is a site that bonds to a carbon atom derived from the N-substituted maleimide group of component (b2) (i.e., this applies when components (b2) are bonded to each other).

[0074] Furthermore, as substituent (x), from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion, and heat resistance, the structure derived from component (b2) is X in the general formulas (B-11) and (B-12). B1 It is also preferable that the group contains a structure in which a phenylene group is substituted with a phenylene group or an aliphatic hydrocarbon group, but it is more preferable that the group contains a structure represented by the following general formula (B-21) or (B-22).

[0075] [ka] (In the formula, R b1 , R b2 , X b1 The explanations for q1 and q2 are as described in the general formula (b2-1) above. B1 and * B2 The explanation for this is as described in the general formulas (B-11) and (B-12) above.

[0076] Component (B) preferably has a substituent (x) and a vinyl group (y) in its side chain. Furthermore, the vinyl group (y) is preferably a 1,2-vinyl group found in the structural unit derived from butadiene. The extent to which substituent (x) is present in component (B) can be indicated by the extent to which the vinyl group of component (b1) has been modified by component (b2) (hereinafter referred to as the "vinyl group modification rate"). From the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion, and heat resistance, the vinyl group modification rate is preferably 1% or more, i.e., 1 to 100%, more preferably 1 to 95%, even more preferably 5 to 85%, even more preferably 10 to 80%, particularly preferably 25 to 80%, and most preferably 35 to 75%. Here, the vinyl group modification rate is the value obtained by the method described in the examples.

[0077] The number-average molecular weight of component (B) is not particularly limited, but from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion, and heat resistance, it is preferably 700 to 6,000, more preferably 800 to 5,000, even more preferably 900 to 4,500, and especially preferably 1,000 to 4,000.

[0078] <Thermoplastic elastomer (C)> Examples of thermoplastic elastomers (C) other than component (B) include polyphenylene ether, styrene-based thermoplastic elastomer, urethane-based elastomer, polyester-based elastomer, polyamide-based elastomer, acrylic-based elastomer, and silicone-based elastomer. Among these, styrene-based thermoplastic elastomer is preferred because it exhibits good dielectric properties, moldability, adhesion to conductors, solder heat resistance, glass transition temperature, thermal expansion coefficient, and flame retardancy, and tends to have a good balance of these properties.

[0079] The styrene-based thermoplastic elastomer is not particularly limited as long as it is a thermoplastic elastomer having structural units derived from styrene compounds, and may also have structural units derived from styrene represented by the following general formula (c-1).

[0080] [ka] (In the formula, R c1 R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. c2 k is an alkyl group having 1 to 5 carbon atoms. k is an integer from 0 to 5.

[0081] R c1 and R c2 Examples of alkyl groups having 1 to 5 carbon atoms that can be represented include methyl groups, ethyl groups, n-propyl groups, etc., and it may also be an alkyl group having 1 to 3 carbon atoms, and if it is a methyl group... That's fine. k may be an integer between 0 and 2, or it may be 0 or 1, or it may be 0.

[0082] Structural units other than those derived from styrene compounds in component (C) include structural units derived from butadiene, isoprene, maleic acid, and maleic anhydride. Among these, it is preferable that there be one or more selected from structural units derived from butadiene and isoprene, with structural units derived from butadiene being more preferable. (C) Component may be used alone or in combination of two or more types. 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 butadiene units and butylene units, or 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.

[0083] (C) Component is preferably one or more selected from the group consisting of hydrogenated styrene-butadiene-styrene block copolymers (e.g., SBBS and SEBS), hydrogenated styrene-isoprene-styrene block copolymers (SEPS), and styrene-maleic anhydride copolymers (SMA), from the viewpoint of dielectric properties, adhesion to conductors, heat resistance, glass transition temperature, and coefficient of thermal expansion. Here, hydrogenated styrene-butadiene-styrene block copolymers include SBBS, in which 60-85% of the carbon-carbon double bonds at the 1,2-bonding sites in the butadiene block are hydrogenated, and SEBS, in which the hydrogenation rate of the carbon-carbon double bonds is usually 90% or more. As for component (C), one or more selected from the group consisting of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) and hydrogenated styrene-isoprene-styrene block copolymer (SEPS) are more preferable from the viewpoint of dielectric properties, adhesion to conductors, heat resistance, glass transition temperature and coefficient of thermal expansion, and hydrogenated styrene-butadiene-styrene block copolymer (SEBS) is even more preferable.

[0084] In the above-mentioned SEBS, the content of styrene-derived structural units [hereinafter sometimes abbreviated as styrene content] is preferably 5 to 80% by mass, more preferably 10 to 75% by mass, even more preferably 15 to 70% by mass, and particularly preferably 20 to 50% by mass, from the viewpoint of dielectric properties, 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. Commercially available SEBS products 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.

[0085] The weight-average molecular weight (Mw) of component (C) is not particularly limited, but is preferably 12,000 to 1,000,000, more preferably 30,000 to 500,000, even more preferably 50,000 to 120,000, and particularly preferably 70,000 to 100,000. The weight-average molecular weight (Mw) is measured in polystyrene equivalent by gel permeation chromatography (GPC).

[0086] <Content of components (A), (B), and (C), and their respective content percentages> In the resin composition of this embodiment, the content of component (A) may be 10 to 90 parts by mass, the content of component (B) may be 1 to 50 parts by mass, and the content of component (C) may be 5 to 60 parts by mass, based on a total of 100 parts by mass of components (A) to (C). In the resin composition of this embodiment, the content of component (A) is preferably 10 to 90 parts by mass, more preferably 20 to 80 parts by mass, even more preferably 30 to 70 parts by mass, and particularly preferably 35 to 60 parts by mass, based on 100 parts by mass of the total sum of components (A) to (C). In the resin composition of this embodiment, the content of component (B) is preferably 1 to 50 parts by mass, more preferably 5 to 40 parts by mass, even more preferably 10 to 30 parts by mass, and particularly preferably 10 to 25 parts by mass, based on 100 parts by mass of the total sum of components (A) to (C), from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion, and heat resistance. In the resin composition of this embodiment, the content of component (C) is preferably 5 to 60 parts by mass, more preferably 10 to 55 parts by mass, even more preferably 15 to 50 parts by mass, particularly preferably 20 to 45 parts by mass, and most preferably 25 to 40 parts by mass, based on 100 parts by mass of the total sum of components (A) to (C). If the content of component (C) is 5 parts by mass or more based on 100 parts by mass of the total sum of components (A) to (C), dielectric properties and moisture resistance tend to be better, and if it is 60 parts by mass or less, heat resistance, moldability, processability, and flame retardancy tend to be better.

[0087] The content ratio of component (A) to component (B) [(A) / (B)] is not particularly limited, but from the viewpoint of compatibility with other resins, dielectric properties, low thermal expansion, and heat resistance, it is preferably greater than 1.0, more preferably 1.5 to 5.0, even more preferably 1.8 to 4.5, even more preferably 2.0 to 4.0, particularly preferably 2.2 to 3.5, and most preferably 2.5 to 3.2 by mass. If the content ratio [(A) / (B)] is greater than 1.0, excellent dielectric properties tend to be obtained in the high frequency band of 10 GHz or higher, and if it is 5.0 or less, excellent heat resistance, moldability, and processability tend to be obtained.

[0088] <Other ingredients> The resin composition of this embodiment may further contain other components. Other components include, for example, one or more selected from the group consisting of inorganic fillers (D) [hereinafter sometimes abbreviated as component (D)], flame retardants (E) [hereinafter sometimes abbreviated as component (E)], and curing accelerators (F) [hereinafter sometimes abbreviated as component (F)]. By including these, the various properties when the laminate is formed can be further improved. However, the resin composition of this embodiment does not necessarily have to contain one or more components selected from the group consisting of components (D), (E), and (F), depending on the desired performance. The following details these components.

[0089] (Inorganic filler (D)) By incorporating an inorganic filler (D) into the resin composition of this embodiment, it tends to be possible to improve the coefficient of thermal expansion, elastic modulus, heat resistance, and flame retardancy. Component (D) is not particularly limited, but examples include silica, alumina, titanium oxide, mica, beryllium, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay (such as calcined clay), talc, aluminum borate, silicon carbide, etc. Component (D) may be used alone or in combination of two or more. Among these, silica, alumina, mica, and talc are preferred from the viewpoint of thermal expansion coefficient, 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, etc. Dry-process silica can further be described by different manufacturing methods, such as crushed silica, fumed silica, and fused silica (fused spherical silica). The shape and particle size of the inorganic filler (D) are not particularly limited, but for example, the particle size is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm, even more preferably 0.2 to 1 μm, and particularly preferably 0.3 to 0.8 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 particle size of the inorganic filler (D) can be measured using a particle size distribution analyzer that uses laser diffraction scattering or the like.

[0090] When the resin composition of this embodiment contains component (D), the content of component (D) in the resin composition is not particularly limited, but from the viewpoint of thermal expansion coefficient, elastic modulus, heat resistance and flame retardancy, it is preferably 5 to 70% by mass, more preferably 15 to 65% by mass, even more preferably 20 to 60% by mass, particularly preferably 30 to 55% by mass, and most preferably 40 to 50% by mass, relative to the total solid content of the resin composition.

[0091] Furthermore, when using component (D), a coupling agent may be used in combination as needed to improve the dispersibility of component (D) and the adhesion between component (D) and the organic components in the resin composition. The coupling agent is not particularly limited, and for example, a silane coupling agent or a titanate coupling agent may be appropriately selected and used. One coupling agent may be used alone, or two or more may be used in combination. The amount of coupling agent used is also not particularly limited. When using a coupling agent, it is also possible to use a so-called integral blending method in which the coupling agent is added after the component (D) has been incorporated into the resin composition. However, it is preferable to use an inorganic filler that has been pre-treated with the coupling agent by a dry or wet surface treatment. By adopting this method, the characteristics of component (D) can be expressed more effectively.

[0092] In this embodiment, when component (D) is used, component (D) may be used as a slurry in which it has been pre-dispersed in an organic solvent in order to improve the dispersibility of component (D) in the resin composition. The organic solvent used when forming the slurry of component (D) is not particularly limited, but for example, the organic solvents exemplified in the manufacturing process of component (A1) described above can be used.

[0093] (Flame retardant (E)) By incorporating a flame retardant (E) into the resin composition of this embodiment, the flame retardancy of the resin composition tends to be improved. Examples of component (E) include phosphorus-based flame retardants, metal hydrates, halogen-based flame retardants, etc. From an environmental perspective, component (E) may be phosphorus-based flame retardants and metal hydrates. Component (E) may be used alone or in combination of two or more. Furthermore, a flame retardant aid may be included as needed.

[0094] -Phosphorus-based flame retardant- The phosphorus-based flame retardant is not particularly limited as long as it contains phosphorus atoms and is generally used as a flame retardant; it may be an inorganic or organic phosphorus-based flame retardant. From an environmental standpoint, phosphorus-based flame retardants that do not contain halogen atoms are preferred. From the viewpoint of dielectric properties, adhesion to conductors, heat resistance, glass transition temperature, coefficient of thermal expansion, and flame retardancy, the phosphorus-based flame retardant may be an organic phosphorus-based flame retardant. Examples of inorganic phosphorus-based flame retardants include red phosphorus; ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and polyammonium phosphate; inorganic nitrogen-containing phosphorus compounds such as phosphate amides; phosphoric acid; and phosphine oxide. Examples of organic phosphorus-based flame retardants include aromatic phosphate esters, phosphonic acid diesters, phosphinic acid esters, metal salts of phosphinic acid, organic nitrogen-containing phosphorus compounds, and cyclic organophosphorus compounds. Among these, aromatic phosphate ester compounds and metal salts of phosphinic acid are preferred. Here, the metal salt may be, for example, any of lithium salt, sodium salt, potassium salt, calcium salt, magnesium salt, aluminum salt, titanium salt, or zinc salt, and may also be aluminum salt. Among organic phosphorus-based flame retardants, aromatic phosphate esters are preferred.

[0095] Examples of aromatic phosphate esters include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl di-2,6-xylenyl phosphate, resorcinol bis(diphenyl phosphate), 1,3-phenylene bis(di-2,6-xylenyl phosphate), bisphenol A-bis(diphenyl phosphate), and 1,3-phenylene bis(diphenyl phosphate).

[0096] Examples of phosphonic acid diesters include divinyl phenylphosphonate, diallyl phenylphosphonate, and bis(1-butenyl) phenylphosphonate. Examples of phosphinate esters include phenyl diphenylphosphinate and methyl diphenylphosphinate. Examples of metal salts of phosphinic acid include metal salts of dialkylphosphinic acid, metal salts of diallylphosphinic acid, metal salts of divinylphosphinic acid, and metal salts of diarylphosphinic acid. These metal salts may be lithium salts, sodium salts, potassium salts, calcium salts, magnesium salts, aluminum salts, titanium salts, or zinc salts, and may also be aluminum salts.

[0097] Examples of organic nitrogen-containing phosphorus compounds include phosphazene compounds such as bis(2-allylphenoxy)phosphazene and dicresylphosphazene; melamine phosphate; melamine pyrophosphate; melamine polyphosphate; and melamine polyphosphate. Examples of cyclic organophosphorus compounds include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. Among these, aromatic phosphate esters and metal salts of phosphinic acid are preferred, aromatic phosphate esters and metal salts of dialkylphosphinic acid are more preferred, and 1,3-phenylenebis(di-2,6-xylenyl phosphate) and tris(dialkylphosphinic acid)aluminum salts are even more preferred.

[0098] -Metal hydrate- Examples of metal hydrates include aluminum hydroxide hydrate and magnesium hydroxide hydrate. These may be used individually or in combination of two or more. While these metal hydroxides may also be inorganic fillers, they are classified as flame retardants if they can impart flame retardancy to the material. -Halogen-based flame retardant- Examples of halogen-based flame retardants include chlorine-based flame retardants and bromine-based flame retardants. Examples of chlorine-based flame retardants include chlorinated paraffins.

[0099] When the resin composition of this embodiment contains component (E), and a phosphorus-based flame retardant is used as component (E), the content of the phosphorus-based flame retardant in the resin composition is not particularly limited, but for example, it is preferably 0.2 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and even more preferably 0.5 to 5 parts by mass, in terms of phosphorus atoms, per 100 parts by mass of the total amount of resin components in the resin composition. When the content of component (E) in terms of phosphorus atoms is 0.2 parts by mass or more per 100 parts by mass of the total amount of resin components, better flame retardancy tends to be obtained, and when it is 20 parts by mass or less, better moldability, high adhesion to conductors, excellent heat resistance and a high glass transition temperature tend to be obtained.

[0100] (Curing accelerator (F)) By including a curing accelerator (F) in the resin composition of this embodiment, the curability of the resin composition tends to be improved, and the dielectric properties, heat resistance, adhesion to conductors, elastic modulus, and glass transition temperature can be enhanced. (F) Component may include acidic catalysts such as p-toluenesulfonic acid; amine compounds such as triethylamine, pyridine, and tributylamine; imidazole compounds such as methylimidazole, phenylimidazole, and isocyanate-masquimidazole (e.g., the addition 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. These may be used individually or in combination of two or more. Among these, from the viewpoint of heat resistance, glass transition temperature, and storage stability, imidazole compounds, organic peroxides, and carboxylates may be used, and from the viewpoint of heat resistance, glass transition temperature, elastic modulus, and coefficient of thermal expansion, imidazole compounds may be used in combination with organic peroxides or carboxylates. Furthermore, among organic peroxides, α,α'-bis(t-butylperoxy)diisopropylbenzene may be selected, and among carboxylates, manganese naphthenate may be selected.

[0101] When the resin composition of this embodiment contains component (F), the content of component (F) is not particularly limited, but for example, it is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, even more preferably 0.1 to 5 parts by mass, and particularly preferably 0.2 to 2 parts by mass, based on 100 parts by mass of the total amount of resin components in the resin composition. When the content of component (F) is within the above range, better heat resistance and storage stability tend to be obtained.

[0102] The resin composition of this embodiment may further contain, as needed, other thermoplastic resins, elastomers, and other resin materials, as well as antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, lubricants, etc., selected as appropriate. These may be used individually or in combination of two or more. Furthermore, the amount used is not particularly limited and should be within a range that does not impair the effects of this embodiment.

[0103] (organic solvent) The resin composition of this embodiment may contain an organic solvent from the viewpoint of making it easier to handle by dilution and from the viewpoint of making it easier to manufacture the prepreg described later. A resin composition containing an organic solvent is generally sometimes referred to as a resin varnish or varnish. The organic solvent is not particularly limited, but examples include alcoholic solvents such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether solvents such as tetrahydrofuran; aromatic 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 solvents such as γ-butyrolactone. Among these, from the viewpoint of solubility, alcohol-based solvents, ketone-based solvents, and nitrogen atom-containing solvents are preferred, ketone-based solvents are more preferred, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone are even more preferred, and methyl ethyl ketone is particularly preferred. Organic solvents may be used individually or in combination of two or more.

[0104] When the resin composition of this embodiment contains an organic solvent, its solid content concentration is, for example, 30 to 90% by mass, may be 35 to 80% by mass, or 40 to 60% by mass. By using a resin composition with a solid content concentration within the above range, handling becomes easier, the impregnation into the substrate and the appearance of the manufactured prepreg are good, the adjustment of the solid content concentration of the resin in the prepreg (described later) becomes easier, and the manufacture of a prepreg with a desired thickness tends to become easier.

[0105] The resin composition of this embodiment can be produced by mixing components (A), (B), and (C), and other components used in combination as needed, in a known manner. In this case, each component may be dissolved or dispersed while stirring. The mixing order, temperature, time, and other conditions are not particularly limited and can be set arbitrarily according to the type of raw materials, etc.

[0106] The resin composition of this embodiment has good compatibility, and tends not to produce precipitates even after being left for a day. Furthermore, in embodiments with even better compatibility, tends not to produce precipitates even after being left for a week (however, phase separation may occur), and in embodiments with even better compatibility, tends not to undergo phase separation at all, even after being left for a week.

[0107] The dielectric constant (Dk) at 10 GHz of the cured product of the resin composition of this embodiment (a laminate and a cured resin film that do not contain a fibrous base material such as glass cloth) is preferably 3.0 or less, more preferably 2.9 or less, and even more preferably 2.8 or less. The smaller the dielectric constant (Dk), the better, 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 dielectric loss tangent (Df) at 10 GHz of the cured product of the resin composition of this embodiment (a laminate and a cured resin film that do not contain a fibrous base material such as glass cloth) is preferably 0.0030 or less, more preferably 0.0025 or less, even more preferably 0.0023 or less, particularly preferably 0.0022 or less, and most preferably 0.0020 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 dielectric constant (Dk) and dielectric loss tangent (Df) are values ​​obtained in accordance with the cavity resonator perturbation method, and more specifically, are values ​​measured by the method described in the examples. In this specification, when the term dielectric constant is used, it refers to the relative dielectric constant.

[0108] [Method for producing maleimide resin composition] The method for producing the maleimide resin composition of this embodiment is a method for producing a maleimide resin composition that includes the following steps 1 and 2. Step 1: A step to obtain (B) a modified conjugated diene polymer by reacting (b1) a conjugated diene polymer having vinyl groups in its side chains with (b2) a maleimide compound having two or more N-substituted maleimide groups. Step 2: A step of mixing (A) one or more maleimide compounds selected from the group consisting of maleimide compounds having one or more N-substituted maleimide groups and derivatives thereof, (B) a modified conjugated diene polymer, and (C) a thermoplastic elastomer other than the component in (B). The preferred conditions for the reaction in step 1 are as described in the explanation for component (B). The mixing in step 2 may be carried out using a known stirrer or the like. For example, it is preferable to add components (A), (B), and (C) to the above-mentioned organic solvent and then stir and mix them at room temperature or under heating. The heating temperature during mixing is, for example, 30 to 100°C, preferably 40 to 90°C. The concentrations of components (A), (B), and (C) in the mixed solution at the time of mixing are the same as the preferred range of solid content concentration of the resin composition in the resin composition of this embodiment when the resin composition contains an organic solvent, as described above.

[0109] [Prepreg] The prepreg of this embodiment is a prepreg containing the maleimide resin composition of this embodiment or a semi-cured product of the maleimide resin composition. The prepreg of this embodiment contains, for example, the resin composition of this embodiment or a semi-cured product of the resin composition and a sheet-like fibrous substrate. The prepreg is formed using the resin composition of this embodiment and a sheet-like fibrous substrate, and can be obtained, for example, by impregnating or coating the sheet-like fibrous substrate with the resin composition of this embodiment, drying it, and partially curing it (B-stage) as necessary. More specifically, the prepreg of this embodiment can be manufactured by heating and drying it in a drying oven at a temperature of 80 to 200°C for 1 to 30 minutes to partially cure it (B-stage). Hereinafter, B-stage means reaching the B-stage state as defined in JIS K6900 (1994). The amount of resin composition used can be appropriately determined with the aim of achieving a solid content concentration of 30-90% by mass in the prepreg after drying. By setting the solid content concentration within this range, better moldability tends to be obtained when the laminate is formed.

[0110] As the sheet-like fiber base material for the prepreg, known materials used in laminates for various electrical insulating materials can be used. The sheet-like fiber base material is not particularly limited, but it is preferably a sheet-like fiber reinforcing base material used for the purpose of reinforcing the prepreg. Examples of materials for the sheet-like fiber base material 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 base materials may have shapes such as woven fabrics, nonwoven fabrics, rawhide, chopped strand mats, or surfacing mats. The thickness of the sheet-like fiber base material is not particularly limited, but for example, a thickness of 0.02 to 0.5 mm can be used. Furthermore, sheet-like fibrous substrates can be those that have been surface-treated with a coupling agent or the like, or those that have been mechanically opened, from the viewpoint of impregnation properties of the resin composition, heat resistance, moisture resistance when formed into a laminate, and processability.

[0111] The following hot-melt method or solvent method can be used as a method for impregnating or coating a sheet-like fibrous substrate with a resin composition. The hot melt method does not include organic solvents in the resin composition and involves (1) first coating a coated paper with good release properties from the resin composition and then laminating it onto a sheet-like fibrous substrate, or (2) coating a sheet-like fibrous substrate with the resin composition using a die coater. On the other hand, the solvent method involves incorporating an organic solvent into a resin composition, immersing a sheet-like fibrous substrate in the resulting resin composition to impregnate the sheet-like fibrous substrate, and then drying it.

[0112] [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 a resin composition containing an organic solvent, i.e., a resin varnish, to a support, heating and drying it, and partially curing it (B-stage) as needed. Examples of support materials include polyolefin films such as polyethylene, polypropylene, and polyvinyl chloride; polyester films such as polyethylene terephthalate (hereinafter also referred to as "PET") and polyethylene naphthalate; and various plastic films such as polycarbonate films and polyimide films. Alternatively, metal foils such as copper foil and aluminum foil, or release paper may be used as support materials. The support material may be subjected to surface treatments such as matte finish or corona treatment. Furthermore, the support material may be subjected to release treatments such as silicone resin-based release agents, alkyd resin-based release agents, or fluororesin-based release agents. The thickness of the support is not particularly limited, but is preferably 10 to 150 μm, and more preferably 25 to 50 μm.

[0113] The method for applying the resin varnish to the support is not particularly limited, and coating apparatus known to those skilled in the art, such as comma coaters, bar coaters, kiss coaters, roll coaters, gravure coaters, and die coaters, can be used. These coating apparatuses can be appropriately selected depending on the film thickness. The drying temperature and drying time can be appropriately determined according to the amount of organic solvent used and the boiling point of the organic solvent used. For example, in the case of a resin varnish containing about 40-60% by mass of organic solvent, a resin film can be suitably formed by drying at 50-150°C for about 3-10 minutes.

[0114] [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. The laminate of this embodiment can be manufactured, for example, by placing metal foil on one or both sides of a single prepreg of this embodiment, or by placing metal foil on one or both sides of a prepreg obtained by stacking two or more prepregs of this embodiment, and then by heat and pressure molding. In the laminate obtained by this manufacturing method, the prepreg of this embodiment is C-staged. In this specification, C-staged means being in the state of C-stage as defined in JIS K6900 (1994). Laminates having metal foil are sometimes referred to as metal-clad laminates. The metal of the metal foil is not particularly limited, but from the viewpoint of conductivity, it may be copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing one or more of these metal elements. Copper and aluminum are preferred, and copper is more preferred. The conditions for heat-pressure molding are not particularly limited, but for example, it can be carried out within the range of a temperature of 100 to 300°C, a pressure of 0.2 to 10 MPa, and a time of 0.1 to 5 hours. In addition, a method of maintaining a vacuum state for 0.5 to 5 hours using a vacuum press or the like can be employed for heat-pressure molding.

[0115] [Printed wiring board] The printed circuit board of this embodiment comprises one or more selected from the group consisting of a cured resin composition of this embodiment, a cured prepreg, and a laminate of this embodiment. The printed circuit board of this embodiment can be manufactured by using one or more selected from the group consisting of the prepreg of this embodiment, the resin film of this embodiment, and the laminate of this embodiment, and performing circuit formation processing such as drilling, metal plating, and metal foil etching by known methods, and further, if necessary, a multilayer printed circuit board can be manufactured by performing multilayer bonding processing. In the printed circuit board of this embodiment, the prepreg of this embodiment and the resin film of this embodiment are C-staged.

[0116] [Semiconductor Packages] The semiconductor package of this embodiment is a semiconductor package having a printed circuit board and semiconductor elements. The semiconductor package of this embodiment can be manufactured by mounting semiconductor elements such as semiconductor chips and memory at predetermined positions on the printed circuit board of this embodiment.

[0117] The resin composition, prepreg, resin film, laminate, printed circuit board, and semiconductor package of this embodiment can be suitably used in electronic equipment that handles high-frequency signals of 10 GHz or higher. In particular, the printed circuit board is useful as a printed circuit board for millimeter-wave radar.

[0118] Although preferred embodiments have been described above, these are merely examples for the purpose of explaining this embodiment, and are not intended to limit the scope of this embodiment to those embodiments only. This embodiment can be implemented in various forms different from those described above without departing from its spirit. [Examples]

[0119] The embodiment will be described in detail below with reference to examples. However, this embodiment is not limited to the following examples.

[0120] In each example, the number-average molecular weight was measured using the following procedure. (Method for measuring number-average molecular weight) The number-average molecular weight 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℃

[0121] (Measurement of vinyl group modification rate) The value obtained by the following method was defined as the vinyl group modification rate of the modified conjugated diene polymer (B1). GPC was measured in the same manner as described above for the liquid containing components (b1) and (b2) before the reaction and for the liquid containing the modified conjugated diene polymer (B1) obtained after the reaction. The rate of decrease in the peak area derived from component (b2) before and after the reaction, i.e., (peak area derived from component (b2) before reaction - peak area derived from component (b2) after reaction) × 100 / (peak area derived from component (b2) before reaction), was calculated and the obtained value was defined as the vinyl group modification rate.

[0122] [Manufacturing of Modified Conjugated Diene Polymers] Manufacturing Examples 1-5 In a 2 L glass flask container equipped with a thermometer, reflux condenser, and stirring device, the amounts of components (b1) and (b2), an organic peroxide, and toluene as an organic solvent, as shown in Table 1, were added and reacted under a nitrogen atmosphere at 90-100°C for 5 hours with stirring to obtain a liquid (toluene diluted solution, solid content concentration: 35% by mass) containing modified conjugated diene polymers B-1 to B-5. Table 1 shows the vinyl group modification rate and number-average molecular weight of the obtained modified conjugated diene polymers.

[0123] [Table 1]

[0124] The details of each component listed in Table 1 are as follows: [(b1) component] Polybutadiene 1:1,2-polybutadiene homopolymer, number-average molecular weight = 3,200, vinyl group content = 90% or more Polybutadiene 2:1,2-polybutadiene homopolymer, number-average molecular weight = 2,100, vinyl group content = 90% or more Polybutadiene 3:1,2-polybutadiene homopolymer, number-average molecular weight = 1,200, vinyl group content = 85% or more [(b2) component] • Bismaleimide compound 1: 4,4'-diphenylmethanebismaleimide • Bismaleimide compound 2: 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane • Bismaleimide compound 3: 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide [Reaction catalyst] • Organic peroxide: α,α'-bis(t-butylperoxy)diisopropylbenzene

[0125] Examples 1-6, Comparative Examples 1-3 (Preparation of resin composition) Each component listed in Table 2 was heated and stirred together with a predetermined amount of curing accelerator according to the blending amounts (unit: parts by mass) listed in Table 2, at room temperature or 50-80°C, and methyl ethyl ketone was added as appropriate to prepare a resin composition with a solid content (non-volatile content) concentration of approximately 50% by mass. (Preparation of resin plates with copper foil on both sides) The resin compositions obtained in each example were coated onto a 38 μm thick PET film (manufactured by Teijin Limited, product name: G2-38), and then heated and dried at 170°C for 5 minutes to produce a resin film in the B-stage state. After peeling this resin film from the PET film, it was crushed to obtain a resin powder. Next, the above resin powder was placed in a Teflon® sheet cut to a size of 1 mm thick × 50 mm long × 35 mm wide, and 18 μm thick low-profile copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., product name: 3EC-VLP-18) was placed above and below it, with the M-side in contact with the resin powder. Subsequently, the resin composition was cured by heating and pressurizing under the conditions of 230°C, 2.0 MPa pressure, and 120 minutes, to produce a double-sided copper foil-coated resin plate (resin plate thickness: 1 mm).

[0126] [Measurement or evaluation method] The resin compositions and double-sided copper foil-coated resin plates obtained in the above examples and comparative examples were used for the following measurements and evaluations. The results are shown in Table 2.

[0127] (1. Method for evaluating the compatibility of resin compositions) The compatibility (macroscopic phase separation and presence or absence of precipitates) of the resin compositions obtained in each example was evaluated by visual observation according to the following criteria. A is the most preferred, B is within the acceptable range, and C is undesirable. A: Even after being left for more than a week, no macroscopic phase separation or precipitates were observed. B: No change occurred after leaving it for one day. However, after leaving it for more than three days, although no precipitates were found, some macroscopic phase separation had occurred. C: After being left for one day, precipitates and macroscopic phase separation had occurred.

[0128] (2. Evaluation method for dielectric properties (dielectric constant and dielectric loss tangent)) A 2mm x 50mm evaluation substrate was fabricated from the evaluation substrate obtained by removing the copper foil from the double-sided copper foil-covered resin plate obtained in each example by immersing it in a 10% by mass solution of ammonium persulfate (manufactured by Mitsubishi Gas Chemical Company, Inc.), which is a copper etching solution. The dielectric constant (Dk) and dielectric loss tangent (Df) of the evaluation substrate were measured at 10 GHz in an ambient temperature of 25°C, in accordance with the cavity resonator perturbation method.

[0129] (3. Method for measuring thermal expansion coefficient) The coefficient of thermal expansion (in the thickness direction, temperature range: 30~120°C) was measured using a thermomechanical measuring device (TMA) [T.A. Instruments Japan Co., Ltd., Q400 (model number)] with 5 mm square test specimens obtained by etching the copper foil on both sides of the double-sided copper foil resin plate obtained in each example, in accordance with the IPC (The Institute for Interconnecting and Packaging Electronic Circuits) standard.

[0130] (4. Method for measuring peel strength) The peel strength was measured using the "EZ-Test / CE" manufactured by Shimadzu Corporation according to the following method. The copper foil of the double-sided copper foil resin plate obtained in each example was processed into a 5 mm wide straight line by etching, and then dried at 105°C / 1h to prepare the test specimen. Using this test specimen, the peel strength was measured by peeling the copper foil in a 90° direction in accordance with JIS C6481. The tensile speed was set to 50 mm / min.

[0131] (5. Method for evaluating heat resistance) The double-sided copper foil-covered resin plates obtained in each example were etched to remove the copper foil, and these were used as test specimens (40 mm x 40 mm). Using a pressure cooker "HA-300M" (manufactured by Hirayama Seisakusho Co., Ltd.), the test specimens were treated at 121°C and 0.11 MPa for a specified time, and then immersed in a 288°C molten solder bath for 20 seconds. After that, the test specimens were visually inspected for the presence or absence of blistering and evaluated according to the following criteria. A: No swelling was found. C: A swollen area was found.

[0132] [Table 2]

[0133] The materials listed in Table 2 are as follows: [(A) component] • Bismaleimide compound A-1: ​​Bis(4-maleimidephenyl)methane • Bismaleimide compound A-2: 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane • Bismaleimide compound A-3: 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide • Polymaleimide compound A-4: Biphenylaralkyl type maleimide (MIR-3000, manufactured by Nippon Kayaku Co., Ltd.)

[0134] [(B) Component] • Modified conjugated diene polymers B-1 to B-5: Modified conjugated diene polymers obtained in Production Examples 1 to 5 were used, respectively. [(B') component] • 1,2-Polybutadiene homopolymer (unmodified), number-average molecular weight = 3,200, vinyl group content = 90% or more

[0135] [(C) component] • Thermoplastic elastomer C-1: Styrene-ethylene-butylene-styrene copolymer (SEBS), styrene content 42% by mass, Mw = 75,000 • Thermoplastic elastomer C-2: Styrene-ethylene-butylene-styrene copolymer (SEBS), styrene content 30 mass, Mw = 86,000

[0136] [(D) component] • Spherical silica: Average particle size 0.5 μm

[0137] [(E) component] • Aluminum tris(diethylphosphinate)

[0138] [(F) component] • Organic peroxides: Dicumyl peroxides

[0139] As is clear from the results shown in Table 2, the maleimide resin compositions obtained in Examples 1 to 6 of this embodiment exhibit good compatibility and therefore excellent handling properties. Furthermore, the cured products prepared using the maleimide resin compositions obtained in Examples 1 to 6 of this embodiment exhibit excellent heat resistance, low thermal expansion, and peel strength, as well as excellent dielectric properties in the high frequency band of 10 GHz. On the other hand, the maleimide resin composition obtained in Comparative Example 1 had poor compatibility and was difficult to handle. Furthermore, while Comparative Example 2 had good compatibility, it exhibited poor heat resistance. Comparative Example 3 had insufficient dielectric properties in the high-frequency band of 10 GHz. [Industrial applicability]

[0140] The maleimide resin composition of this embodiment has good compatibility, and laminates made from this maleimide resin composition have excellent heat resistance and dielectric properties in high frequency bands of 10 GHz or higher, making them useful for printed circuit boards used in fifth-generation mobile communication system (5G) antennas that use radio waves in frequency bands exceeding 6 GHz and millimeter-wave radars that use radio waves in frequency bands of 30 to 300 GHz.

Claims

1. (A) One or more selected from the group consisting of maleimide compounds having one or more N-substituted maleimide groups and derivatives thereof (except for those obtained by modifying a conjugated diene polymer having a vinyl group in its side chain with (b1) a maleimide compound having two or more N-substituted maleimide groups), (B) Modified conjugated diene polymer and (C) A thermoplastic elastomer other than the component in (B), The (B) component is obtained by modifying a conjugated diene polymer having a vinyl group in the (b1) side chain with a maleimide compound having two or more N-substituted maleimide groups (b2). The above component (C) is a styrene-based thermoplastic elastomer, A maleimide resin composition in which the content ratio of component (A) to component (B) [(A) / (B)] is greater than 1.0 on a mass basis, and the content of component (A) is 10 to 90 parts by mass, component (B) is 1 to 50 parts by mass, and component (C) is 20 to 60 parts by mass, per 100 parts by mass of the total sum of components (A) to (C).

2. The maleimide resin composition according to claim 1, wherein component (B) has a substituent (x) in its side chain formed by the reaction of a vinyl group of component (b1) and an N-substituted maleimide group of component (b2).

3. The maleimide resin composition according to claim 2, wherein the substituent (x) is a group containing a structure represented by the following general formula (B-11) or (B-12) as a structure derived from component (b2). 【Chemistry 1】 (In the formula, X Ｂ１ is a divalent organic group, * Ｂ１ This is the site where component (b1) bonds to a carbon atom derived from the vinyl group in its side chain. Ｂ２ (This is a site that bonds to other atoms.)

4. The maleimide resin composition according to any one of claims 1 to 3, wherein the number average molecular weight of component (B) is 700 to 6,000.

5. The maleimide resin composition according to any one of claims 1 to 4, wherein the (b1) component is polybutadiene having a 1,2-vinyl group.

6. The maleimide resin composition according to claim 5, wherein the content of structural units having 1,2-vinyl groups is 50 mol% or more with respect to the total amount of structural units derived from butadiene constituting the polybutadiene having 1,2-vinyl groups.

7. The maleimide resin composition according to any one of claims 1 to 6, wherein the (b2) component is at least one selected from the group consisting of aromatic bismaleimide compounds having two N-substituted maleimide groups in the molecule and aromatic polymaleimide compounds having three or more N-substituted maleimide groups in the molecule.

8. The maleimide resin composition according to any one of claims 2 to 7, wherein the vinyl group modification rate in component (B) is 25 to 95%.

9. The maleimide resin composition according to any one of claims 1 to 8, wherein, with respect to 100 parts by mass of the total sum of components (A) to (C), the content of component (A) is 30 to 70 parts by mass, the content of component (B) is 10 to 30 parts by mass, and the content of component (C) is 25 to 40 parts by mass.

10. A prepreg containing the maleimide resin composition according to any one of claims 1 to 9 or a semi-cured product of the maleimide resin composition.

11. A resin film containing the maleimide resin composition according to any one of claims 1 to 9 or a semi-cured product of the maleimide resin composition.

12. A laminate having a cured maleimide resin composition according to any one of claims 1 to 9 or a cured prepreg according to claim 10, and a metal foil.

13. A printed circuit board having one or more selected from the group consisting of a cured maleimide resin composition according to any one of claims 1 to 9, a cured prepreg according to claim 10, and a laminate according to claim 12.

14. A semiconductor package having a printed circuit board according to claim 13 and a semiconductor element.

15. A method for producing a maleimide resin composition according to any one of claims 1 to 9, comprising the following steps 1 and 2. Step 1: A step to obtain (B) a modified conjugated diene polymer by reacting (b1) a conjugated diene polymer having vinyl groups in its side chains with (b2) a maleimide compound having two or more N-substituted maleimide groups. Step 2: A step of mixing (A) one or more maleimide compounds selected from the group consisting of maleimide compounds having one or more N-substituted maleimide groups and derivatives thereof, (B) a modified conjugated diene polymer, and (C) a thermoplastic elastomer other than the component in (B).

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