Resin composition, prepreg, resin-equipped film, resin-equipped metal foil, metal-clad laminated sheet, and wiring board

Abstract

One aspect of the present invention relates to a resin composition which contains a crosslinking agent (A) and a phenylmaleimide compound (B). The crosslinking agent (A) includes at least one of (i) a vinylbenzyl indene represented by formula (1) and (ii) a vinylbenzyl fluorene represented by formula (2). The mass ratio of the crosslinking agent (A) and the phenylmaleimide compound (B) is 5:95 to 95:5.

Description

Resin compositions, prepregs, resin-coated films, resin-coated metal foils, metal-clad laminates, and wiring boards

[0001] The present invention relates to resin compositions, prepregs, resin-coated films, resin-coated metal foils, metal-clad laminates, and wiring boards.

[0002] As the amount of information processing required for various electronic devices increases, mounting technologies such as the high integration of semiconductor devices, high density of wiring, and multilayering are advancing. Furthermore, the wiring boards used in various electronic devices are required to be high-frequency compatible, such as millimeter-wave radar substrates in automotive applications. In order to increase the signal transmission speed, wiring boards used in various electronic devices are required to reduce signal transmission losses, and this is especially important for high-frequency compatible wiring boards. To meet this requirement, the substrate material that constitutes the base material of the wiring board used in various electronic devices is required to have low dielectric constant and dielectric loss tangent.

[0003] Examples of such base materials include a resin composition comprising a polymaleimide compound, modified PPE (polyphenylene ether), and a filler (Patent Document 1), and a resin composition comprising a crosslinking agent selected from vinylbenzylindene, vinylbenzylfluorene, or mixtures thereof, and a polyphenylene ether derivative, a hydrocarbon thermoplastic resin, a maleimide compound, or a mixture thereof (Patent Document 2).

[0004] Resin compositions containing polymaleimide compounds and modified polyphenylene ethers, as described in Patent Document 1, can achieve a certain degree of low dielectric properties, but they suffer from poor moldability and high thermal expansion coefficients. Similarly, while resin compositions described in Patent Document 2 are excellent in terms of low dielectric properties, they also have high thermal expansion coefficients.

[0005] Electronic devices, particularly small portable devices such as mobile communication terminals and notebook PCs, are rapidly becoming more multifunctional, high-performance, and thinner and smaller. Consequently, the printed circuit boards used in these products are required to have finer conductor wiring, multi-layered conductor wiring layers, thinner designs, and improved mechanical properties. In particular, as printed circuit boards become thinner and larger, a problem arises where semiconductor packages, on which semiconductor chips are mounted, warp occurs, leading to mounting defects. To suppress warping of semiconductor packages, the substrate material constituting the insulating layer of the printed circuit board is required to have a low coefficient of thermal expansion in its cured form. Furthermore, moldability and heat resistance (high glass transition temperature) are also important factors in achieving the aforementioned high performance.

[0006] International Publication No. 2019 / 138992, International Publication No. 2022 / 207741

[0007] The present invention has been made in view of these circumstances, and aims to provide a resin composition that can produce a cured product with low dielectric properties and a high glass transition temperature (Tg) while maintaining excellent moldability and a low coefficient of thermal expansion. The present invention also aims to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that can be obtained using the above resin composition.

[0008] After various studies, the inventors found that the above objective could be achieved by the following configuration, and through further investigation, they achieved the present invention.

[0009] In other words, a resin composition according to one aspect of the present invention comprises a crosslinking agent (A) and a phenylmaleimide compound (B), wherein the crosslinking agent (A) is (i) an indene compound (A1) represented by the following formula (1), [In formula (1), R １ Each of these is independently selected from a hydrogen atom, a halogen atom, a C1-C5 alkyl group, a C1-C5 alkoxy group, a C1-C5 thioalkoxy group, a C6-C14 thioaryloxy group, a C6-C14 aryl group, and combinations thereof. １are each independently selected from a hydrogen atom, a vinylbenzyl group, and combinations thereof, and F １ at least one of is a vinylbenzyl group.] and (ii) comprises at least one of an indene compound (A2) represented by the following formula (2), [In the formula (2), R １ are each independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, a thioaryloxy group having 6 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, and combinations thereof. F ２ are each independently selected from a hydrogen atom, a vinylbenzyl group, and a structure of the following formula (3), and F ２ at least one of is a structure of the following formula (3).] [In the formula (3), n, p and p' are each independently a value in the range of 0 to 50. R １ are each independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, a thioaryloxy group having 6 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, and combinations thereof. F ２’ are each independently selected from a hydrogen atom and a vinylbenzyl group, and F in the aforementioned formula (2) ２ and F ２’ at least one of is a vinylbenzyl group. F ４ is selected from a divalent group of the following formula (4), and combinations thereof.] [In the formula (4), Q are each independently selected from a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and combinations thereof. R ２ are each independently selected from a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a halogen atom, and combinations thereof.] The resin composition, wherein a mass ratio of the crosslinking agent (A) to phenylmaleimide (B) is 5:95 to 95:5.

[0010] FIG. 1 is a schematic cross-sectional view showing an example of a prepreg according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of a metal-clad laminate according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing an example of a wiring board according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing an example of a metal foil with resin according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing an example of a film with resin according to an embodiment of the present invention. FIG. 6 is a １ 1H-NMR spectrum diagram showing the mixture of an indene compound (A1) and an indene compound (A2) according to an example of the present invention.

[0011] Hereinafter, embodiments according to the present invention will be specifically described, but the present invention is not limited thereto.

[0012] [Resin Composition] The resin composition according to the present embodiment contains a crosslinking agent (A) and a phenylmaleimide compound (B). The crosslinking agent (A) contains at least one of (i) the indene compound (A1) represented by the above formula (1) and (ii) the indene compound (A2) represented by the above formula (2). Further, the mass ratio of the crosslinking agent (A) to the phenylmaleimide compound (B) is from 5:95 to 95:5.

[0013] With the above configuration, a resin composition capable of obtaining a cured product having low dielectric properties and a high glass transition temperature (Tg) while maintaining excellent moldability and a low coefficient of thermal expansion can be provided. Furthermore, according to the present invention, by using the resin composition, a prepreg, a film with resin, a metal foil with resin, a metal-clad laminate, and a wiring board having the above excellent properties can be provided.

[0014] First, each component of the resin composition of the present embodiment will be described.

[0015] [Crosslinking Agent (A)] As described above, the crosslinking agent (A) is (i) the indene compound (A1) represented by the following formula (1), [In formula (1), R １Each of these is independently selected from a hydrogen atom, a halogen atom, a C1-C5 alkyl group, a C1-C5 alkoxy group, a C1-C5 thioalkoxy group, a C6-C14 thioaryloxy group, a C6-C14 aryl group, and combinations thereof. １ Each is independently selected from a hydrogen atom, a vinylbenzyl group, and combinations thereof, and F １ (ii) [In formula (2), R １ Each of these is independently selected from a hydrogen atom, a halogen atom, a C1-C5 alkyl group, a C1-C5 alkoxy group, a C1-C5 thioalkoxy group, a C6-C14 thioaryloxy group, a C6-C14 aryl group, and combinations thereof. ２ Each of these is independently selected from a hydrogen atom, a vinylbenzyl group, and the structure of formula (3) below, and F ２ At least one of them has the structure of formula (3) below. [In equation (3), n, p, and p' are each independent values ​​in the range of 0 to 50. R １ Each of these is independently selected from a hydrogen atom, a halogen atom, a C1-C5 alkyl group, a C1-C5 alkoxy group, a C1-C5 thioalkoxy group, a C6-C14 thioaryloxy group, a C6-C14 aryl group, and combinations thereof. ２’ These are independently selected from a hydrogen atom and a vinylbenzyl group, and are F of formula (2) described above. ２ and F ２’ At least one of them is a vinylbenzyl group. F ４ This is selected from the divalent group of formula (4) below, and its combinations. [In formula (4), Q is independently selected from a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and combinations thereof. R ２Each of these is independently selected from a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a halogen atom, and combinations thereof.

[0016] The crosslinking agent (A) is not particularly limited as long as it contains at least one of indene compound (A1) and indene compound (A2).

[0017] The crosslinking agent (A) preferably contains both indene compound (A1) and indene compound (A2). Specifically, the crosslinking agent (A) preferably contains one or more indene compounds (A1) and one or more indene compounds (A2). By containing one or more indene compounds (A1) and one or more indene compounds (A2) in the crosslinking agent (A), the above-mentioned effects can be obtained more reliably.

[0018] The crosslinking agent (A) may be synthesized by any method known to those skilled in the art, and is not particularly limited. A preferred synthesis method will be described below as an example.

[0019] For example, a crosslinking agent (A) containing at least one of indene compound (A1) and indene compound (A2) can be synthesized by reacting one or more indene compounds represented by the following formula (7) with one or more biphenyl compounds represented by the following formula (8) and one or more vinylbenzene compounds represented by the following formula (9) in the presence of an alkali.

[0020] [In formula (7), R １ Each of these can be independently selected from a hydrogen atom, a halogen atom, a C1-C5 alkyl group, a C1-C5 alkoxy group, a C1-C5 thioalkoxy group, a C6-C14 thioaryloxy group, a C6-C14 aryl group, and combinations thereof.

[0021] [In formula (8), X can be independently selected from a halogen atom, a tosylate, a mesylate, a triflate, and combinations thereof. Q can be independently selected from a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and combinations thereof. R２ Each of these can be independently selected from a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a halogen atom, and combinations thereof.

[0022] [In formula (9), X' can be selected from a halogen atom, a tosylate, a mesylate, a triflate, and combinations thereof.]

[0023] In the synthesis reaction of the crosslinking agent (A), a fluorene compound may optionally be included as part of the reaction mixture. This synthesis reaction can be carried out under conditions known to those skilled in the art as a vinyl benzylation reaction. A vinyl benzylation reaction is described, for example, in U.S. Patent Application Publication No. 2005 / 0176909.

[0024] In the above formula (7), indene compound (A1), and / or indene compound (A2) representing an indene compound, R １ It is located in the phenyl portion of the indene diring.

[0025] In the above formula (7), indene compound (A1), and / or indene compound (A2) representing the indene compound, all R １ is a hydrogen atom, or one R １ is a halogen atom, a C1-C5 alkyl group, or a C1-C5 alkoxy group, and other R １ Preferably, it is a hydrogen atom.

[0026] In particular, in the above formula (7) representing the indene compound, indene compound (A1), and / or indene compound (A2), all R １ It is most preferable that the atom is a hydrogen atom and the compound of formula (7) is indene.

[0027] In the above formula (8) representing a biphenyl compound, X may be selected from a halogen atom, tosylate, mesylate, triflate, and combinations thereof, more preferably a halogen atom, and even more preferably a chlorine atom or a bromine atom. Preferably, all X are the same. Particularly preferably, all X are chlorine atoms.

[0028] The above formula (8) represents a biphenyl compound, and / or F ４ In the above formula (4) representing the above, Q is preferably independently selected from a hydrogen atom, a methyl group, an ethyl group, and combinations thereof, and more preferably selected from a hydrogen atom, a methyl group, and combinations thereof. Preferably, all Qs are the same. Particularly preferably, all Qs are hydrogen atoms.

[0029] In the above formula (8) representing a biphenyl compound, R ２ Preferably, each of these is independently selected from a hydrogen atom, a methyl group, and a combination thereof. Preferably, all R ２ They are identical. Particularly preferably, all R ２ It is a hydrogen atom.

[0030] The biphenyl compound represented by formula (8) above is preferably 4,4'-bis(chloromethyl)biphenyl.

[0031] It is most preferable that the compound represented by formula (7) is indene, and the biphenyl compound represented by formula (8) is 4,4'-bis(chloromethyl)biphenyl.

[0032] In the above formula (9) representing a vinylbenzene compound, X' is preferably selected from a chlorine atom, a bromine atom, an iodine atom, a tosylate, a mesylate, a triflate, and combinations thereof, and more preferably from a chlorine atom, a bromine atom, and combinations thereof. -CH ２ The -X' group may be located at the ortho, meta, or para position of the aromatic ring, or it may be a mixture of these positional isomers.

[0033] The vinylbenzene compound represented by formula (9) above is particularly preferably selected from the group consisting of 2-vinylbenzyl chloride, 3-vinylbenzyl chloride, 4-vinylbenzyl chloride, 2-vinylbenzyl bromide, 3-vinylbenzyl bromide, 4-vinylbenzyl bromide, and mixtures thereof.

[0034] The vinylbenzene compound represented by formula (9) above is more preferably a mixture of 10% to 50% by weight of 2-vinylbenzyl chloride, 0% to 10% by weight of 3-vinylbenzyl chloride, and 50% to 80% by weight of 4-vinylbenzyl chloride.

[0035] Furthermore, in the indene compound (A2), F ２’ It is more preferable that the vinylbenzyl group corresponds to a mixture of 10% to 50% by weight of a 2-vinylbenzyl substituent, 0% to 10% by weight of a 3-vinylbenzyl substituent, and 50% to 80% by weight of a 4-vinylbenzyl substituent.

[0036] In the structure of the indene compound (A2) represented by formula (3) above, the range of n+p is preferably from 0 to 50, and more preferably from 0 to 10, independently of each other.

[0037] In the indene compound (A2), F ２ Preferably, each of these is independently selected from a hydrogen atom, a vinylbenzyl group, and the structure of formula (3) above with p=0.

[0038] In the synthesis reaction of the crosslinking agent (A), the molar ratio of the indene compound of formula (7) to the biphenyl compound of formula (8) is selected so as not to cause gelation or precipitation by the biphenyl compound of formula (8). Furthermore, if the amount of the vinylbenzene compound of formula (9) is too small, the curability will decrease, and the physical properties of the cured product, such as heat resistance, will deteriorate.

[0039] When present in the biphenyl compound of formula (8) and the vinylbenzene compound of formula (9), the molar ratio of all halomethyl groups, preferably chloromethyl groups, to the reaction site in the indene compound of formula (7) is preferably 0.95 or less. In this context, “halomethyl group” (also known as “halogenated methyl radical”) means a methyl group substituted with one halogen atom, which occurs when Q is a hydrogen atom and X is a halogen atom in formula (8), and X' is a halogen atom in formula (9). In this context, “reaction site” refers to a carbon atom in a five-membered indene ring having acidic hydrogen, which can be deprotonated by the alkali used in the reaction step.

[0040] In the synthesis reaction of the crosslinking agent (A), the molar ratio of the indene compound of formula (7) to the biphenyl compound of formula (8) is preferably in the range of 1.8 / 1 to 3 / 1.

[0041] In the synthesis reaction of the crosslinking agent (A), the molar ratio of the indene compound of formula (7) to the vinylbenzene compound of formula (9) is preferably in the range of 1 / 1 to 1 / 2, more preferably 1 / 1.75, and most preferably 1 / 1.5.

[0042] To obtain the optimal crosslinking agent (A), it is preferable that at least two, and most preferably all three, of the above conditions regarding the ratio of the compounds are satisfied.

[0043] When the crosslinking agent (A) contains one or more indene compounds (A1) and one or more indene compounds (A2), it is preferable that the amount of one or more indene compounds (A1) is 1% to 50% by weight relative to the total weight of the crosslinking agent (A).

[0044] When the crosslinking agent (A) contains one or more indene compounds (A1) and one or more indene compounds (A2), it is preferable that the amount of one or more indene compounds (A2) is 50% to 99% by weight relative to the total weight of the crosslinking agent (A).

[0045] Thus, the crosslinking agent (A) contained in the resin composition according to this embodiment may be a mixture of one or more indene compounds (A1) and one or more indene compounds (A2), or it may be the final product obtained by the synthesis reaction described above, or it may contain at least one of the indene compounds (A1) and indene compounds (A2). In addition, the final product obtained by the synthesis reaction described above may also include other products resulting from the reaction of the indene compound of formula (7), the biphenyl compound of formula (8), and the vinylbenzene compound of formula (9).

[0046] The weight-average molecular weight Mw of the crosslinking agent (A) is preferably 500 g / mol to 10,000 g / mol, and more preferably 500 g / mol to 5,000 g / mol. In this specification, the weight-average molecular weight Mw of the crosslinking agent (A) is the value measured by gel permeation chromatography (GPC) in accordance with ISO 13885-1:2020.

[0047] The polydispersity of the crosslinking agent (A) is preferably 2.01 to 5, and more preferably 2.01 to 3. In this specification, the polydispersity of the crosslinking agent (A) is the value measured by gel permeation chromatography (GPC) in accordance with ISO 13885-1:2020.

[0048] The physical properties of the crosslinking agent (A) described above relate to all of the following: the crosslinking agent (A) comprising a mixture of one or more indene compounds (A1) and one or more indene compounds (A2); the crosslinking agent (A) which is the final product obtained by the above synthesis reaction; or the crosslinking agent (A) comprising at least one of the indene compounds (A1) and indene compounds (A2).

[0049] The resin composition of this embodiment contains the crosslinking agent (A) described above and the phenylmaleimide compound (B) described later in a predetermined ratio, thereby enabling the cured product to have extremely excellent low dielectric properties (especially low dielectric loss tangent) and high Tg while maintaining a low coefficient of thermal expansion and moldability.

[0050] The amount of crosslinking agent (A) in the resin composition of this embodiment is preferably 5 parts by mass or more and 95 parts by mass or less per 100 parts by mass of the total of the resin components in the resin composition, i.e., the crosslinking agent (A), the phenylmaleimide compound (B) described later, and, if the styrene copolymer (C) described later is included, the styrene copolymer (C) described later. This is considered to make the above-mentioned effects more reliable. A more preferable range for the amount is 10 parts by mass or more and 90 parts by mass or less.

[0051] (Phenylmaleimide Compound (B)) The phenylmaleimide compound (B) included in the resin composition of this embodiment is not particularly limited as long as it is a maleimide compound having a phenyl group. In a preferred embodiment, the phenylmaleimide compound (B) includes a maleimide compound having at least one of an indan structure and an arylene structure bonded in an orientation at the meta position. By including such a phenylmaleimide compound (B), a resin composition can be obtained in which the cured product possesses both low dielectric properties and a low coefficient of thermal expansion.

[0052] The phenylmaleimide compound (B) specifically includes at least one selected from the group consisting of a maleimide compound (B1) having an indan structure in its molecule, a maleimide compound (B2) having an arylene structure bonded in a meta position, and a maleimide compound (B3) having an indan structure and an arylene structure bonded in a meta position.

[0053] Maleimide compound (B1) having an indane structure in its molecule Maleimide compound (B1) is not particularly limited as long as it is a maleimide compound having an indane structure in its molecule. Note that maleimide compound (B1) has not only an indane structure but also a maleimide group in its molecule. An example of an indane structure is the indane structure represented by the following formula (3). Specifically, maleimide compound (B1) may include maleimide compound (B1-1) having a structure represented by the following formula (M-1) in its molecule as the indane structure, and more specifically, maleimide compound (B1-1-1) represented by the following formula (M-2).

[0054]

[0055] In formula (M-1), each Rb is independent. That is, each Rb may be the same group or different groups. For example, when r is 2 or 3, the two or three Rb groups bonded to the same benzene ring may be the same group or different groups. Rb represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group (alkoxy group) having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group (thiol group). r represents 0 to 3.

[0056]

[0057] In formula (M-2), each Ra is independent. That is, each Ra may be the same group or a different group. For example, when q is 2 to 4, the 2 to 4 Ra groups bonded to the same benzene ring may be the same group or a different group. Ra represents a C1-C10 alkyl group, a C1-C10 alkyloxy group, a C1-C10 alkylthio group, a C6-C10 aryl group, a C6-C10 aryloxy group, a C6-C10 arylthio group, a C3-C10 cycloalkyl group, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. Rb is the same as Rb in formula (M-1), and each independently represents a C1-C10 alkyl group, a C1-C10 alkyloxy group, a C1-C10 alkylthio group, a C6-C10 aryl group, a C6-C10 aryloxy group, a C6-C10 arylthio group, a C3-C10 cycloalkyl group, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. q represents 0-4. r represents 0-3. n represents 0.95-10.

[0058] r is the average value of the degree of substitution of Rb, and a smaller value is preferable, specifically, a value of 0 is preferable. That is, in the benzene ring to which Rb can be bonded, it is preferable that a hydrogen atom is bonded at the position where Rb can be bonded. Maleimide compounds (B1) with such r are easy to synthesize. This is thought to be because the steric hindrance is reduced and the electron density of the aromatic ring is increased. Furthermore, when r is 1 to 3, it is preferable that Rb is at least one selected from the group consisting of C1-C4 alkyl groups, C3-C6 cycloalkyl groups, and C6-C10 aryl groups. Furthermore, it is preferable that Ra is at least one selected from the group consisting of C1-C4 alkyl groups, C3-C6 cycloalkyl groups, and C6-C10 aryl groups. By using C1-C4 alkyl groups, C3-C6 cycloalkyl groups, and C6-C10 aryl groups, solubility in solvents is improved, and the decrease in the reactivity of the maleimide group can be suppressed, resulting in a suitable cured product. This is thought to be due to a decrease in planarity and crystallinity near the maleimide group.

[0059] The groups represented by Ra and Rb specifically include the following groups:

[0060] The C1-C10 alkyl group is not particularly limited, and examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0061] The alkyloxy group having 1 to 10 carbon atoms is not particularly limited, and examples include a methyloxy group, an ethyloxy group, a propyloxy group, a hexyloxy group, and a decyloxy group.

[0062] The alkylthio group having 1 to 10 carbon atoms is not particularly limited, and examples include a methylthio group, an ethylthio group, a propylthio group, a hexylthio group, and a decylthio group.

[0063] The aryl group having 6 to 10 carbon atoms is not particularly limited, and examples include a phenyl group and a naphthyl group.

[0064] The aryloxy group having 6 to 10 carbon atoms is not particularly limited, and examples include a phenyloxy group and a naphthyloxy group.

[0065] The arylthio group having 6 to 10 carbon atoms is not particularly limited, and examples include a phenylthio group and a naphthylthio group.

[0066] The cycloalkyl group having 3 to 10 carbon atoms is not particularly limited, and examples include a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, and a cyclooctyl group.

[0067] Examples of the halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0068] q is the average degree of substitution of Ra, preferably 2 to 3, and more preferably 2. Maleimide compounds (B1) with such a q are easy to synthesize. This is thought to be because, especially when q is 2, the steric hindrance decreases and the electron density of the aromatic ring increases.

[0069] n is the average value of the number of repetitions, and as described above, it is 0.95 to 10, preferably 0.98 to 8, more preferably 1 to 7, and even more preferably 1.1 to 6. The maleimide compound (B1-1) having the indane structure represented by formula (M-1) in its molecule and the maleimide compound (B1-1-1) represented by formula (M-2) preferably contains a maleimide compound in which the average value of the number of repetitions (degree of polymerization), n, is 0, and is 32% by mass or less of the total amount of maleimide compound (B1).

[0070] The maleimide compound (B1) preferably has a molecular weight distribution (Mw / Mn) of 1 to 4, more preferably 1.1 to 3.8, even more preferably 1.2 to 3.6, and particularly preferably 1.3 to 3.4, as determined by GPC measurement. The molecular weight distribution is obtained by gel permeation chromatography (GPC).

[0071] Maleimide compound (B2) having an arylene structure bonded in the meta position Maleimide compound (B2) is not particularly limited as long as it has an arylene structure bonded in the meta position in the molecule. Note that maleimide compound (B2) has not only an arylene structure but also a maleimide group in the molecule. Examples of arylene structures include an arylene structure in which a structure containing a maleimide group is bonded in the meta position (an arylene structure in which a structure containing a maleimide group is substituted in the meta position). Examples of arylene structures include m-arylene groups such as m-phenylene groups and m-naphthylene groups. Specifically, an arylene structure of maleimide compound (B2) may be an arylene group bonded in the meta position, such as the group represented by the following formula (M-3).

[0072]

[0073] Examples of maleimide compounds (B2) include maleimide compound (B2-1) represented by the following formula (M-4), and more specifically, maleimide compound (B2-1-2) represented by the formula (M-5) described later.

[0074]

[0075] In formula (M-4), Ar represents an arylene group oriented and bonded at the meta position. Ａ , R Ｂ , R Ｃ , and R Ｄ They are independent of each other. That is, R Ａ , R Ｂ , R Ｃ , and R Ｄ These may be the same group or different groups. Also, R Ａ , R Ｂ , R Ｃ , and R Ｄ R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a phenyl group, and is preferably a hydrogen atom. Ｅ and R Ｆ They are independent of each other. That is, R Ｅ and RＦ This may be the same group or different groups. Also, R Ｅ and R Ｆ represents an aliphatic hydrocarbon group. s represents 1 < s < 5.

[0076] The arylene group is not particularly limited as long as it is an arylene group that is oriented and bonded at the meta position. Examples include m-arylene groups such as m-phenylene groups and m-naphthylene groups, and more specifically, the group represented by the formula (M-3) above.

[0077] Examples of alkyl groups having 1 to 5 carbon atoms include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, and neopentyl groups.

[0078] The aliphatic hydrocarbon group is a divalent group and may be acyclic or cyclic. Examples of the aliphatic hydrocarbon group include alkylene groups, and more specifically, methylene groups, methylmethylene groups, and dimethylmethylene groups. Among these, dimethylmethylene groups are preferred.

[0079] The maleimide compound (B2-1) represented by the above formula (M-4) preferably has a repeating number s of 1 to 5. This s is the average value of the repeating number (degree of polymerization).

[0080]

[0081] In equation (M-5), s represents 1 < s < 5. This s is the same as s in equation (M-4) and is the average value of the number of repetitions (degree of polymerization).

[0082] The maleimide compound (B2-1) represented by formula (M-4) and the maleimide compound (B2-1-1) represented by formula (M-5) may contain a monofunctional compound where s is 0, as long as the average value of the number of repeats (degree of polymerization), s, is 1 < s < 5, and may also contain polyfunctional compounds such as heptafunctional or octafunctional compounds where s is 6 or more.

[0083] As the maleimide compound (B2), commercially available products can also be used, for example, the solid content in MIR-5000-60T manufactured by Nippon Kayaku Co., Ltd., and the solid content in NE-X-9470S manufactured by DIC Corporation.

[0084] As the maleimide compound (B2), the maleimide compounds exemplified above may be used individually, or two or more may be used in combination. For example, as the maleimide compound (B2), the maleimide compound (B2-1) represented by formula (M-4) may be used individually, or two or more maleimide compounds (B2-1) represented by formula (M-4) may be used in combination. When two or more maleimide compounds (B2-1) represented by formula (M-4) are used in combination, for example, a maleimide compound (B2-1) represented by formula (M-4), other than the maleimide compound (B2-1-1) represented by formula (M-5), may be used in combination with the maleimide compound (B2-1-1) represented by formula (M-5).

[0085] Maleimide compound (B3) having an indane structure and an arylene structure bonded to the meta position in its molecule Maleimide compound (B3) is not particularly limited as long as it has an indane structure and an arylene structure bonded to the meta position in its molecule. Note that maleimide compound (B3) has not only an arylene structure and an indane structure, but also a maleimide group in its molecule. The indane structure of maleimide compound (B3) is the same as the indane structure in maleimide compound (B1), and the arylene structure of maleimide compound (B3) is the same as the arylene structure bonded to the meta position in maleimide compound (B2). Specifically, maleimide compounds (B3) include those represented by the following formulas (M-6) to (M-8).

[0086]

[0087] In equation (M-6), n represents a value between 0.95 and 10.

[0088]

[0089] In equation (M-7), n represents a range of 0.95 to 10.

[0090]

[0091] In equation (M-8), n represents a value between 0.95 and 10.

[0092] As the phenylmaleimide compound (B), the maleimide compounds described above may be used alone or in combination of two or more. The content of maleimide compound (B1) in the phenylmaleimide compound (B) is preferably 40 to 100 parts by mass, and more preferably 50 to 100 parts by mass, per 100 parts by mass of the phenylmaleimide compound (B). The content of maleimide compound (B2) is preferably 40 to 100 parts by mass, and more preferably 50 to 100 parts by mass, per 100 parts by mass of the phenylmaleimide compound (B). The content of maleimide compound (B3) is preferably 40 to 100 parts by mass, and more preferably 50 to 100 parts by mass, per 100 parts by mass of the phenylmaleimide compound (B).

[0093] In the resin composition of this embodiment, the ratio of the crosslinking agent (A) to the phenylmaleimide compound (B) is 5:95 to 95:5 by mass ratio. This makes it possible to obtain a resin composition that has excellent moldability and low thermal expansion coefficient in its cured product, while also possessing a high Tg and very good low dielectric properties. A more preferred range for the mass ratio is 15:85 to 85:15, and even more preferably 25:75 to 75:25.

[0094] The content of the phenylmaleimide compound (B) in the resin composition of this embodiment is preferably 5 parts by mass or more and 95 parts by mass or less with respect to 100 parts by mass of the total of the resin components in the resin composition, i.e., the crosslinking agent (A) and the phenylmaleimide compound (B), or, if the styrene copolymer (C) described later is included, the total of 100 parts by mass of the components (A), (B), and the styrene copolymer (C). This is considered to make the above-mentioned effects more reliable. A more preferable range for the content is 10 parts by mass or more and 80 parts by mass or less.

[0095] (Styrene polymer (C)) The resin composition of this embodiment may further contain a styrene polymer (C). It is believed that this will allow for even lower dielectric properties (low dielectric loss tangent) and a lower coefficient of thermal expansion in the cured product.

[0096] Examples of styrene polymers (C) that can be used in this embodiment include styrene polymers that are solid at 25°C and can be used as a resin in resin compositions used to form insulating layers in metal-clad laminates and wiring boards, etc. The resin composition used to form insulating layers in metal-clad laminates and wiring boards, etc. may be a resin composition used to form resin layers in resin-coated films and resin-coated metal foils, etc., or a resin composition contained in a prepreg.

[0097] Specific styrene copolymers (C) can be broadly defined from those already known and are not particularly limited. Examples include copolymers obtained by copolymerizing one or more monomers containing styrene (styrene monomers) with one or more other monomers copolymerizable with styrene monomers. Styrene copolymers (C) may be random copolymers or block copolymers. Examples of block copolymers include binary copolymers of structural units (repeating units) derived from the styrene monomer and structural units (repeating units) derived from the other copolymerizable monomers, and ternary copolymers of structures (repeating units) derived from the styrene monomer, structural units (repeating units) derived from the other copolymerizable monomers, and structural units (repeating units) derived from the styrene monomer. Styrene polymers (C) may also be hydrogenated styrene copolymers obtained by hydrogenating the styrene copolymers described above.

[0098] The styrene monomer is not particularly limited, but examples include styrene, styrene derivatives, styrene in which some of the hydrogen atoms of the benzene ring are substituted with alkyl groups, styrene in which some of the hydrogen atoms of the vinyl group are substituted with alkyl groups, vinyltoluene, α-methylstyrene, butylstyrene, dimethylstyrene, and isopropenyltoluene. The styrene monomer may be used individually or in combination of two or more. The other copolymerizable monomers are not particularly limited, but examples include olefins such as α-pinene, β-pinene, and dipentene, non-conjugated dienes such as 1,4-hexadiene and 3-methyl-1,4-hexadiene, and conjugated dienes such as 1,3-butadiene and 2-methyl-1,3-butadiene (isoprene). The other copolymerizable monomers may be used individually or in combination of two or more.

[0099] More specifically, examples of styrene-based polymers (C) include polymers having a structural unit represented by the following formula (S-1) (a structure derived from the styrene-based monomer) in their molecule.

[0100] In formula (S-1), R １ ~R ３ Each independently represents a hydrogen atom or an alkyl group, R ４ This represents a group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, and an isopropenyl group. The alkyl group is not particularly limited, but for example, an alkyl group having 1 to 18 carbon atoms is preferred, and an alkyl group having 1 to 10 carbon atoms is more preferred. Specifically, examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group. Furthermore, the alkenyl group is preferably an alkenyl group having 1 to 10 carbon atoms.

[0101] The styrene polymer (C) preferably contains at least one structural unit represented by formula (S-1), and may contain a combination of two or more different units. Furthermore, the styrene polymer may contain a structure in which the structural unit represented by formula (S-1) is repeated.

[0102] In addition to the structural unit represented by formula (S-1), the styrene polymer (C) may have at least one of the following structural units derived from other monomers copolymerizable with the styrene monomer: the structural unit represented by formula (S-2), formula (S-3), and formula (S-4), or a structure in which the structural unit represented by formula (S-2), formula (S-3), and formula (S-4) is repeated.

[0103] In formulas (S-2), (S-3), and (S-4), R ５ ~R ２２ Each of these independently represents a group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, and an isopropenyl group. The alkyl group is not particularly limited, but for example, an alkyl group having 1 to 18 carbon atoms is preferred, and an alkyl group having 1 to 10 carbon atoms is more preferred. Specifically, examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group. Furthermore, the alkenyl group is preferably an alkenyl group having 1 to 10 carbon atoms.

[0104] The styrene polymer (C) preferably contains at least one of the structural units represented by formulas (S-2), (S-3), and (S-4), and may contain a combination of two or more different types of these units. Furthermore, the styrene polymer (C) may have at least one structure in which the structural units represented by formulas (S-2), (S-3), and (S-4) are repeated.

[0105] More specifically, the structural units represented by formula (S-1) include the structural units represented by formulas (S-5) to (S-7) below. Furthermore, the structural units represented by formula (S-1) may also be structures in which the structural units represented by formulas (S-5) to (S-7) below are repeated. The structural units represented by formula (S-1) may be a single unit or a combination of two or more different units.

[0106]

[0107]

[0108]

[0109] More specifically, the structural units represented by formula (S-2) include the structural units represented by the following formulas (S-8) to (S-14). Furthermore, the structural units represented by formula (S-2) may also be structures in which the structural units represented by the following formulas (S-8) to (S-14) are repeated. The structural units represented by formula (S-2) may be a single unit or a combination of two or more different units.

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117] More specifically, the structural units represented by formula (S-3) include the structural units represented by formulas (S-15) and (S-16) below. Furthermore, the structural units represented by formula (S-3) may also be structures in which the structural units represented by formulas (S-15) and (S-16) below are repeated. The structural units represented by formula (S-3) may be a single unit or a combination of two or more different units.

[0118]

[0119]

[0120] More specifically, the structural units represented by formula (S-4) include the structural units represented by formulas (S-17) and (S-18) below. Furthermore, the structural units represented by formula (S-4) may also be structures in which the structural units represented by formulas (S-17) and (S-18) below are repeated, respectively. The structural units represented by formula (S-4) may be a single unit or a combination of two or more different units.

[0121]

[0122]

[0123] Preferred examples of the styrene copolymer (C) include polymers or copolymers obtained by polymerizing or copolymerizing one or more styrene monomers such as styrene, vinyltoluene, α-methylstyrene, isopropenyltoluene, divinylbenzene, and allylstyrene. More specifically, examples of the styrene copolymer include methylstyrene (ethylene / butylene) methylstyrene block copolymer, methylstyrene (ethylene-ethylene / propylene) methylstyrene block copolymer, styrene isoprene block copolymer, styrene isoprene styrene block copolymer, styrene (ethylene / butylene) styrene copolymer, styrene (ethylene-ethylene / propylene) styrene block copolymer, styrene butadiene styrene block copolymer, styrene (butadiene / butylene) styrene block copolymer, and styrene isobutylene styrene block copolymer. Examples of the hydrogenated styrene block copolymer include hydrogenated products of the styrene block copolymer. More specifically, examples of the hydrogenated styrene-based block copolymer include hydrogenated methylstyrene (ethylene / butylene) methylstyrene block copolymer, hydrogenated methylstyrene (ethylene-ethylene / propylene) methylstyrene block copolymer, hydrogenated styrene isoprene block copolymer, hydrogenated styrene isoprene styrene block copolymer, hydrogenated styrene (ethylene / butylene) styrene block copolymer, and hydrogenated styrene (ethylene-ethylene / propylene) styrene block copolymer.

[0124] The styrene polymer (C) may be one of the styrene polymers exemplified above, or two or more may be used in combination.

[0125] The styrene polymer (C) preferably has a weight-average molecular weight of 1,000 to 300,000, and more preferably 1,200 to 200,000. If the molecular weight is too low, the glass transition temperature of the cured resin composition tends to decrease, and the heat resistance tends to decrease. If the molecular weight is too high, the viscosity of the resin composition when it is made into a varnish and the viscosity of the resin composition during heat molding tend to become too high. The weight-average molecular weight can be measured by any general molecular weight measurement method, specifically, values ​​measured using gel permeation chromatography (GPC), etc.

[0126] The styrene polymer (C) can be synthesized by known methods, but commercially available products can also be used. For example, V9827, V9461, 2002, and 7125F from Kuraray Co., Ltd.; FTR2140 and FTR6125 from Mitsui Chemicals, Inc.; and H1041 and M1913 from Asahi Kasei Corporation may be used.

[0127] When the resin composition of this embodiment contains a styrene polymer (C), the content of the styrene polymer (C) is preferably 5 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the total of the resin components in the resin composition, i.e., the crosslinking agent (A), the phenylmaleimide compound (B), and the styrene copolymer (C). This is considered to make the above-mentioned effects more reliable. A more preferable range for the content is 10 parts by mass or more and 30 parts by mass or less.

[0128] (Inorganic Filler (D)) The resin composition of this embodiment may optionally contain an inorganic filler (D) as long as it does not impair the effects of the present invention. It is believed that this can further reduce the thermal expansion coefficient of the cured resin composition. The inorganic filler (D) is not particularly limited as long as it is an inorganic filler that can be used as an inorganic filler contained in the resin composition. Specifically, examples of inorganic filler (D) include fillers made of at least one selected from the group consisting of silica such as spherical silica, alumina, titanium oxide, and metal oxides such as mica, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, talc, aluminum borate, barium sulfate, and calcium carbonate. Among these, silica, mica, and talc are preferred as inorganic fillers, and it is more preferable to use a filler made of at least one selected from the group consisting of spherical silica. In the resin composition of this embodiment, one inorganic filler may be used alone, or two or more may be used in combination.

[0129] The inorganic filler (D) may be a surface-treated inorganic filler or an untreated inorganic filler. Examples of surface treatments include treatment with a silane coupling agent.

[0130] The silane coupling agent is not particularly limited, and examples include silane coupling agents having at least one functional group selected from the group consisting of vinyl group, styryl group, methacryloyl group, acryloyl group, phenylamino group, isocyanurate group, ureido group, mercapto group, isocyanate group, epoxy group, and acid anhydride group. That is, this silane coupling agent has at least one of vinyl group, styryl group, methacryloyl group, acryloyl group, phenylamino group, isocyanurate group, ureido group, mercapto group, isocyanate group, epoxy group, and acid anhydride group as a reactive functional group, and further includes compounds having hydrolyzable groups such as methoxy group and ethoxy group.

[0131] Examples of silane coupling agents having a vinyl group include vinyltriethoxysilane and vinyltrimethoxysilane. Examples of silane coupling agents having a styryl group include p-styryltrimethoxysilane and p-styryltriethoxysilane. Examples of silane coupling agents having a methacryloyl group include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropylethyldiethoxysilane. Examples of silane coupling agents having an acryloyl group include 3-acryloxypropyltrimethoxysilane and 3-acryloxypropyltriethoxysilane. Examples of silane coupling agents having a phenylamino group include N-phenyl-3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltriethoxysilane.

[0132] The content of the inorganic filler (D) is preferably 35 parts by mass or more and 200 parts by mass or less per 100 parts by mass of the total of the crosslinking agent (A), the phenylmaleimide compound (B), and (if a styrene polymer (C) is included, further including the styrene polymer (C)). This is considered to have the advantage of achieving both a low coefficient of thermal expansion and good moldability. A more preferable range for the content is 70 parts by mass or more and 150 parts by mass or less.

[0133] (Other Components) The resin composition may contain components other than those described above (other components) to the extent that they do not impair the effects of the present invention. Examples of other components include organic components other than the crosslinking agent (A), phenylmaleimide compound (B), and styrene polymer (C), flame retardants, reaction initiators, curing accelerators, catalysts, polymerization retardants, polymerization inhibitors, dispersants, leveling agents, coupling agents, defoamers, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes and pigments, and additives such as lubricants.

[0134] As described above, the resin composition according to this embodiment may contain organic components other than the crosslinking agent (A), the phenylmaleimide compound (B), and the styrene polymer (C). The organic component may be, for example, a compound that reacts with at least one of the crosslinking agent (A), the phenylmaleimide compound (B), and the styrene polymer (C), or a compound that does not react with them. Specific examples of the organic component include oxazine compounds, epoxy compounds, cyanate ester compounds, and activated ester compounds.

[0135] As described above, the resin composition of this embodiment may contain a flame retardant. By including a flame retardant, the flame retardancy of the cured resin composition can be enhanced. The flame retardant that can be used is not particularly limited. Specifically, in fields where halogen-based flame retardants such as brominated flame retardants are used, for example, ethylenedipentabromobenzene, ethylenebistetrabromoimide, decabromodiphenyl oxide, tetradecabromodiphenoxybenzene, and bromostyrene compounds that react with the polymerizable compounds, each having a melting point of 300°C or higher, are preferred. It is believed that by using halogen-based flame retardants, the desorption of halogens at high temperatures can be suppressed, thereby suppressing a decrease in heat resistance. On the other hand, in fields where halogen-free is required, flame retardants containing phosphorus (phosphorus-based flame retardants) may be used. The phosphorus-based flame retardant is not particularly limited, but examples include phosphate ester flame retardants, phosphazene flame retardants, bis-diphenylphosphine oxide flame retardants, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) flame retardants, and phosphinate flame retardants. A specific example of a phosphate ester flame retardant is a condensed phosphate ester of dixylenyl phosphate. A specific example of a phosphazene flame retardant is phenoxyphosphazene. A specific example of a bis-diphenylphosphine oxide flame retardant is xylylenebis-diphenylphosphine oxide. Specific examples of DOPO flame retardants include hydrocarbons having two DOPO groups in the molecule (DOPO derivative compounds), and DOPO having a reactive functional group. A specific example of a phosphinate flame retardant is a phosphinate metal salt of an aluminum dialkylphosphinate salt. The flame retardants mentioned above may be used individually or in combination of two or more.

[0136] When a resin composition contains a flame retardant, the amount is not limited, but for example, in the case of a phosphorus-based flame retardant, from the viewpoint of ensuring sufficient flame retardancy, it is preferable that the amount is 5 parts by mass or more and 55 parts by mass or less per 100 parts by mass of the total of the crosslinking agent (A), the phenylmaleimide compound (B), and (if a styrene polymer (C) is included, further including the styrene polymer (C)). A more preferable range for the amount is 15 parts by mass or more and 45 parts by mass or less.

[0137] As described above, the resin composition of this embodiment may contain a reaction initiator. The reaction initiator is not particularly limited as long as it can promote the curing reaction of the resin composition, and examples include peroxides and organic azo compounds. Examples of peroxides include α,α'-di(t-butylperoxy)diisopropylbenzene (PBP), 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexine, and benzoyl peroxide. Examples of organic azo compounds include azobisisobutyronitrile. In addition, metal carboxylate salts can be used in combination as needed. By doing so, the curing reaction can be further promoted. The reaction initiator may be used alone or in combination of two or more types.

[0138] As described above, the resin composition of this embodiment may further contain a polymerization inhibitor or polymerization retarder. This is thought to homogenize the reaction of the resin composition and further improve moldability. There are no particular limitations on the polymerization inhibitor, but free radical compounds and the like can be used.

[0139] If the resin composition contains a polymerization inhibitor, the amount is not limited, but it is preferably 0.01 parts by mass or more and 1.0 parts by mass or less per 100 parts by mass of the total of the crosslinking agent (A), the phenylmaleimide compound (B), and (if it contains a styrene polymer (C), further including the styrene polymer (C)). A more preferable range for the amount is 0.05 parts by mass or more and 0.5 parts by mass or less.

[0140] As described above, the resin composition according to this embodiment may contain a curing accelerator. The curing accelerator is not particularly limited as long as it can accelerate the curing reaction of the resin composition. Specifically, examples of the curing accelerator include imidazoles and their derivatives, organophosphorus compounds, amines such as secondary and tertiary amines, quaternary ammonium salts, organoboron compounds, and metal soaps. Examples of the imidazoles include 2-ethyl-4-methylimidazole (2E4MZ), 2-methylimidazole, 2-phenyl-4-methylimidazole, 2-phenylimidazole, and 1-benzyl-2-methylimidazole. Examples of the organophosphorus compounds include triphenylphosphine, diphenylphosphine, phenylphosphine, tributylphosphine, and trimethylphosphine. Examples of the amines include dimethylbenzylamine, triethylenediamine, triethanolamine, and 1,8-diazabicyclo(5,4,0)undecene-7 (DBU). Examples of the quaternary ammonium salt include tetrabutylammonium bromide. Examples of the organoboron compounds include tetraphenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate, and tetrasubstituted phosphonium tetrasubstituted borates such as tetraphenylphosphonium ethyltriphenylborate. The metal soap refers to a fatty acid metal salt, which may be a linear fatty acid metal salt or a cyclic fatty acid metal salt. Specifically, examples of the metal soap include linear aliphatic metal salts and cyclic aliphatic metal salts having 6 to 10 carbon atoms. More specifically, examples include aliphatic metal salts consisting of linear fatty acids such as stearic acid, lauric acid, ricinoleic acid, and octic acid, or cyclic fatty acids such as naphthenic acid, and metals such as lithium, magnesium, calcium, barium, copper, and zinc. For example, zinc octoate is one example. The curing accelerator may be used alone or in combination of two or more types.

[0141] As described above, the resin composition according to this embodiment may contain a silane coupling agent. The silane coupling agent may be contained in the resin composition, or it may be contained in the inorganic filler contained in the resin composition as a silane coupling agent that has been pre-surface-treated. Among these, it is preferable that the silane coupling agent be contained in the inorganic filler as a silane coupling agent that has been pre-surface-treated, and it is even more preferable that the resin composition also contains the silane coupling agent in this manner. In the case of a prepreg, the prepreg may contain a silane coupling agent that has been pre-surface-treated in the fibrous substrate. Examples of the silane coupling agent include those similar to the silane coupling agent used when surface-treating the inorganic filler as described above.

[0142] (Applications) The resin composition of this embodiment is mainly used in the manufacture of prepregs, as will be described later. In addition to prepregs, the resin composition of this embodiment is used in the formation of resin layers in resin-coated metal foils and resin-coated films, and insulating layers in metal-clad laminates and wiring boards.

[0143] The resin composition according to this embodiment is a resin composition that yields a cured product with low dielectric properties (dielectric loss tangent) and low thermal expansion coefficient. Therefore, a wiring board equipped with an insulating layer formed using the resin composition according to this embodiment has low transmission loss, high reliability, and less warping. Furthermore, in addition to the above properties, the resin composition of this embodiment has a high Tg in its cured product and excellent moldability, making it extremely useful for industrial applications.

[0144] (Manufacturing Method) The method for manufacturing the resin composition of this embodiment is not particularly limited, and examples include mixing a crosslinking agent (A), a phenylmaleimide compound (B), and other resin components as needed, and then adding an inorganic filler (D) as needed. Specifically, when obtaining a varnish-like composition containing an organic solvent, the method described in the prepreg description below can be used.

[0145] By using the resin composition according to this embodiment, prepregs, metal-clad laminates, wiring boards, resin-coated metal foils, and resin-coated films can be obtained as follows.

[0146] [Prepreg] Figure 1 is a schematic cross-sectional view showing an example of a prepreg 1 according to an embodiment of the present invention. In the following description, each reference numeral in the figure indicates: 1 prepreg, 2 resin composition or semi-cured resin composition, 3 fibrous substrate, 11 metal-clad laminate, 12 insulating layer, 13 metal foil, 14 wiring, 21 wiring board, 31 resin-coated metal foil, 32, 42 resin layer, 41 resin-coated film, 43 support film.

[0147] As shown in Figure 1, the prepreg 1 according to this embodiment comprises the resin composition or a semi-cured product 2 of the resin composition and a fibrous base material 3. This prepreg 1 comprises the resin composition or a semi-cured product 2 of the resin composition and a fibrous base material 3 present in the resin composition or the semi-cured product 2 of the resin composition.

[0148] In this embodiment, a semi-cured product refers to a resin composition that has been partially cured to the extent that it can be further cured. In other words, a semi-cured product is a resin composition that has been partially cured (stage B). For example, when a resin composition is heated, its viscosity gradually decreases at first, then curing begins, then curing begins again, and the viscosity gradually increases. In such a case, a semi-cured product would be the state between the time the viscosity begins to increase and before it is completely cured.

[0149] Furthermore, the prepreg obtained using the resin composition according to this embodiment may include a semi-cured product of the resin composition as described above, or it may include the uncured resin composition itself. That is, it may be a prepreg comprising a semi-cured product of the resin composition (the resin composition in stage B) and a fibrous substrate, or it may be a prepreg comprising the uncured resin composition (the resin composition in stage A) and a fibrous substrate. The resin composition or the semi-cured product of the resin composition may be the resin composition that has been dried or heat-dried.

[0150] When manufacturing prepregs, the resin composition 2 is often prepared in a varnish-like form for impregnation into the fibrous substrate 3, which is the base material for forming the prepreg. In other words, the resin composition 2 is usually a resin varnish prepared in a varnish-like form. Such a varnish-like resin composition (resin varnish) is prepared, for example, as follows.

[0151] First, each component of the resin composition that is soluble in an organic solvent is added to the organic solvent and dissolved. Heating may be used as needed during this process. Then, components that are not soluble in the organic solvent (e.g., inorganic fillers) are added as needed, and the mixture is dispersed using a disperser or the like until a predetermined dispersion state is reached, thereby preparing a varnish-like resin composition. The organic solvent used here is not particularly limited as long as it dissolves the radical polymerizable compounds and the like and does not inhibit the curing reaction. Specifically, examples include toluene and methyl ethyl ketone (MEK).

[0152] The method for manufacturing the prepreg is not particularly limited as long as it can produce the prepreg. Specifically, when manufacturing the prepreg, the resin composition used in this embodiment is often prepared in a varnish-like state and used as a resin varnish, as described above.

[0153] Examples of the fibrous base material include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper. When glass cloth is used, a laminate with excellent mechanical strength can be obtained, and flattened glass cloth is particularly preferred. Specific flattening methods include, for example, continuously applying pressure to the glass cloth with a press roll at an appropriate pressure to compress the yarn into a flat shape. The thickness of the fibrous base material commonly used is, for example, 0.01 mm or more and 0.3 mm or less.

[0154] The method for manufacturing the prepreg is not particularly limited as long as it can produce the prepreg. Specifically, when manufacturing the prepreg, the resin composition according to this embodiment is often prepared in a varnish-like state as described above and used as a resin varnish.

[0155] One method for manufacturing the prepreg 1 is to impregnate a fibrous substrate 3 with a resin composition 2, for example, a resin composition 2 prepared in the form of a varnish, and then dry it. The resin composition 2 is impregnated into the fibrous substrate 3 by immersion, coating, etc. It is also possible to repeat the impregnation process multiple times as needed. In this case, it is also possible to adjust to the desired composition and impregnation amount by repeating the impregnation process using multiple resin compositions with different compositions and concentrations.

[0156] The fibrous substrate 3 impregnated with the resin composition (resin varnish) 2 is heated under desired heating conditions, for example, at 80°C to 180°C for 1 minute to 10 minutes. Heating yields a prepreg 1 in either a pre-cured state (Stage A) or a semi-cured state (Stage B). Heating can also cause organic solvents to volatilize from the resin varnish, reducing or removing them.

[0157] [Metal-clad laminate] Figure 2 is a schematic cross-sectional view showing an example of a metal-clad laminate 11 according to an embodiment of the present invention.

[0158] As shown in Figure 2, the metal-clad laminate 11 is composed of an insulating layer 12 containing a cured product of the prepreg 1 shown in Figure 1, and a metal foil 13 laminated together with the insulating layer 12. That is, the metal-clad laminate 11 has an insulating layer 12 containing a cured product of a resin composition, and a metal foil 13 provided on the insulating layer 12. The insulating layer 12 may be made of the cured product of the resin composition, or it may be made of the cured product of the prepreg. The thickness of the metal foil 13 varies depending on the performance required of the final printed circuit board and is not particularly limited. The thickness of the metal foil 13 can be set appropriately according to the desired purpose, and is preferably, for example, 0.2 to 70 μm. Examples of the metal foil 13 include copper foil and aluminum foil, and if the metal foil is thin, it may be a carrier-equipped copper foil with a release layer and carrier to improve handling.

[0159] The method for manufacturing the metal-clad laminate 11 is not particularly limited as long as it can be used to manufacture the metal-clad laminate 11. Specifically, one method is to manufacture the metal-clad laminate 11 using a prepreg 1. This method involves stacking one or more prepregs 1, further stacking metal foil 13 such as copper foil on both the top and bottom surfaces or one or both surfaces, and then heat-pressure molding the metal foil 13 and prepreg 1 to laminate and integrate them, thereby producing a laminate 11 with metal foil on both sides or one side. In other words, the metal-clad laminate 11 is obtained by laminating metal foil 13 onto the prepreg 1 and then heat-pressure molding it. The heating and pressing conditions can be appropriately set depending on the thickness of the metal-clad laminate 11 to be manufactured, the type of composition of the prepreg 1, etc. For example, the temperature can be 170 to 230°C, the pressure 3 to 5 MPa, and the time 60 to 150 minutes. The metal-clad laminate may also be manufactured without using a prepreg. For example, one method involves applying a varnish-like resin composition onto a metal foil to form a layer containing the resin composition on the metal foil, and then heating and pressurizing it.

[0160] [Wiring board] Figure 3 is a schematic cross-sectional view showing an example of a wiring board 21 according to an embodiment of the present invention.

[0161] As shown in Figure 3, the wiring board 21 according to this embodiment is composed of an insulating layer 12 made by curing the prepreg 1 shown in Figure 1, and wiring 14 laminated together with the insulating layer 12 and formed by partially removing the metal foil 13. That is, the wiring board 21 has an insulating layer 12 containing a cured resin composition and wiring 14 provided on the insulating layer 12. The insulating layer 12 may be made of the cured resin composition or of the cured prepreg.

[0162] The method for manufacturing the wiring board 21 is not particularly limited as long as it can be manufactured. Specifically, a method for manufacturing the wiring board 21 using the prepreg 1 can be mentioned. For example, this method involves etching the metal foil 13 on the surface of the metal-clad laminate 11 manufactured as described above to form wiring, thereby manufacturing a wiring board 21 in which wiring is provided as a circuit on the surface of the insulating layer 12. That is, the wiring board 21 is obtained by partially removing the metal foil 13 on the surface of the metal-clad laminate 11 to form a circuit. In addition to the above method, other methods for circuit formation include, for example, circuit formation by the semi-additive process (SAP) or the modified semi-additive process (MSAP).

[0163] [Resin-coated metal foil] Figure 4 is a schematic cross-sectional view showing an example of resin-coated metal foil 31 according to this embodiment.

[0164] As shown in Figure 4, the resin-coated metal foil 31 according to this embodiment comprises a resin layer 32 containing the resin composition or a semi-cured product of the resin composition, and a metal foil 13. This resin-coated metal foil 31 has the metal foil 13 on the surface of the resin layer 32. That is, this resin-coated metal foil 31 comprises the resin layer 32 and the metal foil 13 laminated together with the resin layer 32. In addition, the resin-coated metal foil 31 may have other layers between the resin layer 32 and the metal foil 13.

[0165] The resin layer 32 may contain a semi-cured product of the resin composition as described above, or it may contain the uncured resin composition. That is, the resin-coated metal foil 31 may comprise a resin layer containing a semi-cured product of the resin composition (the resin composition in stage B) and a metal foil, or it may comprise a resin layer containing the uncured resin composition (the resin composition in stage A) and a metal foil. The resin layer may contain the resin composition or a semi-cured product of the resin composition, and may or may not contain a fibrous substrate. The resin composition or the semi-cured product of the resin composition may be the resin composition that has been dried or heat-dried. The fibrous substrate may be the same as that of a prepreg.

[0166] Any metal foil used in metal-clad laminates can be used without limitation. Examples of metal foils include copper foil and aluminum foil.

[0167] The resin-coated metal foil 31 and the resin-coated film 41 may be provided with a cover film or the like, if necessary. Providing a cover film can prevent the incorporation of foreign matter. The cover film is not particularly limited, but examples include polyolefin film, polyester film, polymethylpentene film, and films formed by providing a release agent layer on these films.

[0168] The method for producing the resin-coated metal foil 31 is not particularly limited as long as it can produce the resin-coated metal foil 31. Examples of methods for producing the resin-coated metal foil 31 include applying the varnish-like resin composition (resin varnish) onto the metal foil 13 and heating it. The varnish-like resin composition is applied onto the metal foil 13, for example, by using a bar coater. The applied resin composition is heated, for example, at a temperature of 80°C to 180°C for 1 minute to 10 minutes. The heated resin composition is formed on the metal foil 13 as an uncured resin layer 32. The heating can cause the organic solvent to volatilize from the resin varnish, thereby reducing or removing the organic solvent.

[0169] [Resin-coated film] Figure 5 is a schematic cross-sectional view showing an example of a resin-coated film 41 according to this embodiment.

[0170] As shown in Figure 5, the resin-coated film 41 according to this embodiment comprises a resin layer 42 containing the resin composition or a semi-cured product of the resin composition, and a support film 43. The resin-coated film 41 comprises the resin layer 42 and the support film 43 laminated together with the resin layer 42. The resin-coated film 41 may have other layers between the resin layer 42 and the support film 43.

[0171] The resin layer 42 may contain a semi-cured product of the resin composition as described above, or it may contain the uncured resin composition. That is, the resin-coated film 41 may comprise a resin layer containing a semi-cured product of the resin composition (the resin composition of stage B) and a support film, or it may comprise a resin layer containing the uncured resin composition (the resin composition of stage A) and a support film. The resin layer may contain the resin composition or a semi-cured product of the resin composition, and may or may not contain a fibrous substrate. The resin composition or the semi-cured product of the resin composition may be the resin composition that has been dried or heat-dried. As the fibrous substrate, the same type as the fibrous substrate of the prepreg can be used.

[0172] The support film 43 can be any support film used for resin-coated films without limitation. Examples of such support films include polyester film, polyethylene terephthalate (PET) film, polyimide film, polyparabanic acid film, polyether ether ketone film, polyphenylene sulfide film, polyamide film, polycarbonate film, and electrically insulating films such as polyarylate film.

[0173] The resin-coated film 41 may be provided with a cover film or the like, if necessary. Providing a cover film can prevent the incorporation of foreign matter. The cover film is not particularly limited, but examples include polyolefin film, polyester film, and polymethylpentene film.

[0174] The support film and cover film may be subjected to surface treatments such as matte treatment, corona treatment, release treatment, and roughening treatment, as needed.

[0175] The method for manufacturing the resin-coated film 41 is not particularly limited as long as it can be used to manufacture the resin-coated film 41. Examples of methods for manufacturing the resin-coated film 41 include applying the varnish-like resin composition (resin varnish) onto a support film 43 and heating it. The varnish-like resin composition is applied onto the support film 43, for example, by using a bar coater. The applied resin composition is heated, for example, at a temperature of 80°C to 180°C for 1 minute to 10 minutes. The heated resin composition is formed on the support film 43 as an uncured resin layer 42. The heating can cause organic solvents to volatilize from the resin varnish, thereby reducing or removing the organic solvents.

[0176] The prepregs, resin-coated films, and resin-coated metal foils obtained using the resin composition of this embodiment are extremely useful for industrial applications because their cured products possess excellent low dielectric properties and low thermal expansion coefficients, as well as excellent moldability. Similarly, metal-clad laminates and wiring boards having an insulating layer containing the cured product of the resin composition of this embodiment have the same advantages.

[0177] This specification discloses various aspects of technology as described above, but the main technologies are summarized below.

[0178] A resin composition according to a first aspect of the present invention is a resin composition comprising a crosslinking agent (A) and a phenylmaleimide compound (B), wherein the crosslinking agent (A) comprises at least one of (i) vinylbenzylindene represented by formula (1) and (ii) vinylbenzylfluorene represented by formula (2), and the mass ratio of the crosslinking agent (A) to the phenylmaleimide (B) is 5:95 to 95:5.

[0179] A resin composition according to a second aspect of the present invention is a resin composition according to the first aspect, wherein the phenylmaleimide compound (B) contains a maleimide compound having at least one of an indan structure and an arylene structure bonded in an orientation at the meta position.

[0180] A resin composition according to a third aspect of the present invention is a resin composition according to the first or second aspect, further comprising a styrene copolymer (C).

[0181] A fourth aspect of the present invention is a resin composition in which, in the resin composition of the third aspect, the styrene polymer (C) includes the structural unit of formula (S-1) and at least one structural unit from among the structural units represented by formulas (S-2) to (S-4).

[0182] The fifth aspect of the present invention relates to a resin composition of the third or fourth aspect, wherein the weight-average molecular weight of the styrene polymer (C) is 1,000 to 300,000.

[0183] The resin composition according to the sixth aspect of the present invention is the resin composition according to any third to fifth aspect, wherein the content of styrene copolymer (C) is 5 parts by mass or more and 40 parts by mass or less, based on 100 parts by mass of the total of the crosslinking agent (A), phenylmaleimide compound (B), and styrene copolymer (C).

[0184] The seventh aspect of the present invention is a resin composition according to any of the first to sixth aspects, further containing an inorganic filler (D), wherein the amount of inorganic filler (D) is 35 parts by mass or more and 200 parts by mass or less, based on 100 parts by mass of the crosslinking agent (A) and the phenylmaleimide compound (B).

[0185] A prepreg according to the eighth aspect of the present invention comprises a resin composition according to any of the first to seventh aspects or a semi-cured product of the resin composition, and a fibrous substrate.

[0186] A resin-coated film according to the ninth aspect of the present invention comprises a resin layer containing a resin composition according to any of the first to seventh aspects or a semi-cured product of the resin composition, and a support film.

[0187] A resin-coated metal foil according to the tenth aspect of the present invention comprises a resin layer containing a resin composition according to any of the first to seventh aspects or a semi-cured product of the resin composition, and a metal foil.

[0188] A metal-clad laminate according to the eleventh aspect of the present invention comprises an insulating layer containing a cured product of any of the resin compositions of the first to seventh aspects or a cured product of the prepreg of the eighth aspect, and a metal foil.

[0189] A wiring board according to the twelfth aspect of the present invention comprises an insulating layer containing a cured resin composition of any of the first to seventh aspects or a cured prepreg of the eighth aspect, and wiring.

[0190] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited thereto.

[0191] First, we will describe each component used in preparing the resin composition in this embodiment.

[0192] (Crosslinking agent (A)) Mixture of vinylbenzylindene compound (A1) and indene compound (A2): A mixture of vinylbenzylindene compound (A1) and indene compound (A2) synthesized according to the following method was used. (Synthesis method of mixture of indene compound (A1) and indene compound (A2)) 20.1 g (0.083 mol) of 4,4'-bis(chloromethyl)biphenyl, 25.0 g (0.209 mol) of indene, 3.4 g (0.010 mol) of tetrabutylammonium bromide and 42.7 g (0.280 mol) of vinylbenzyl chloride were dissolved in 500 mL of toluene at an internal temperature of 40°C with continuous stirring in a 1.5 liter reaction flask equipped with a mechanical stirrer, a cooling condenser and a dropping funnel to prepare a homogeneous solution. Subsequently, 140 mL (2.610 mol) of a 50% by weight NaOH aqueous solution was added dropwise to the prepared solution over 30 minutes. After the addition was complete, the internal temperature of the solution was raised to 50°C by external heating. After a reaction time of 9 hours, the mixed solution was diluted with water and separated into two layers. Finally, toluene was removed by distillation to obtain a yellow solid material with a yield of 87%.

[0193] The mixture of the obtained yellow solid substance indene compound (A1) and indene compound (A2) is １ The compounds were identified by 1H-NMR spectroscopy and gel permeation chromatography (GPC) measurements. Figure 6 shows the mixture of the identified indene compounds (A1) and (A2). １ The 1H-NMR spectrum is shown. Gel permeation chromatography (GPC) measurements showed a weight-average molecular weight Mw of 1091 g / mol and a polydispersity of 2.3. The molar ratio of chloromethyl groups to the indene reaction sites is 0.71.

[0194] (Phenylmaleimide compound (B)) Phenylmaleimide compound: A maleimide compound having an indan structure and an arylene structure oriented and bonded at the meta position in its molecule (solid content in "NE-X-9470S" manufactured by DIC Corporation, a maleimide compound represented by the above formula (M-6)).

[0195] (Polymerization retarder) • Free radical compound: 4-benzoyloxy TEMPO (manufactured by Seiko Chemical Co., Ltd.)

[0196] (Flame retardant) ・Flame retardant: Phosphorus-based flame retardant (PQ-60 manufactured by Jin-I Chemical Co., Ltd.)

[0197] (Inorganic filler (D)) - Inorganic filler: Silica filler (manufactured by Zhejiang Sanshiki New Material Technology Co., Ltd., "EQ2410-SMC")

[0198] [Examples 1-4 and Comparative Examples 1-2] (Preparation Method) First, components other than the inorganic filler were added to a mixed solvent of toluene and methyl ethyl ketone (MEK) in the composition (parts by mass) shown in Table 1, so that the solid content concentration was 30-60% by mass, and the mixture was mixed. The resulting mixture was stirred for 60 minutes. Then, the inorganic filler was added to the resulting mixture in the composition (parts by mass) shown in Table 1 and dispersed using a bead mill. In this way, varnish-like resin compositions (varnishes) for each example and comparative example were obtained.

[0199] Next, the prepreg was obtained as follows.

[0200] The obtained varnish was impregnated into a fibrous substrate (glass cloth: manufactured by Nitto Boseki Co., Ltd., #1078 type, NE glass), and then heated and dried at 120°C for 3 minutes to produce a prepreg. At that time, the content of the components constituting the resin in the prepreg (resin content) was adjusted to be approximately 65% ​​by mass. Furthermore, the thickness after curing was adjusted to be 75 μm.

[0201] An evaluation substrate (metal-clad laminate) was obtained in the following manner.

[0202] Two of the obtained prepregs were stacked together, and 18 μm thick copper foil (CF-T4X-SV manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd.) was placed on both sides. This was used as the pressure-bearing body, and it was heated to a temperature of 220°C at a heating rate of 3°C / min. By heating and pressurizing it at 220°C for 120 minutes under a pressure of 3 MPa, an evaluation substrate (metal-clad laminate) with a resin layer thickness of approximately 150 μm was obtained, with copper foil bonded to both sides.

[0203] The evaluation substrate prepared as described above was evaluated using the method shown below.

[0204] <Evaluation Tests> For moldability, the prepregs obtained above were laminated until a thickness of 1 mm or more and used as evaluation samples. For evaluation tests of dielectric properties (dielectric loss tangent Df), Tg, and thermal expansion coefficient, an unclad plate (hardened prepreg, approximately 150 μm thick) obtained by etching off the copper foil from a copper-clad laminate made of two layers of prepreg was used as an evaluation sample in the following evaluation tests.

[0205] [Moldability (Minimum Melt Viscosity)] The minimum melt viscosity of each sample was measured using Soliquid "Rheosol-G3000" manufactured by UBM Co., Ltd. The measurement conditions were as follows: temperature was increased by 3°C from 30°C to 200°C, and a strain of 0.5 deg at 10 Hz was applied. Moldability was judged based on the minimum melt viscosity. In this test, a minimum melt viscosity of less than 1.5 million (poise) was judged as acceptable.

[0206] [Dielectric Properties (Dielectric Loss Tangent)] The dielectric loss tangent (Df) of the evaluation sample at 10 GHz was measured using the cavity resonator perturbation method. Specifically, a network analyzer (N5230A manufactured by Keysight Technologies, Inc.) was used to measure the dielectric loss tangent of the evaluation substrate at 10 GHz. The pass criterion for this test was Df ≤ 0.0023.

[0207] [Thermal Expansion Coefficient (50-125°C)] The evaluation sample was used as a test specimen (size: 14 mm x 4 mm), and the thermal expansion coefficient in the planar direction (tensile direction, Y direction) of the evaluation substrate at a temperature below the glass transition temperature of the cured resin composition was measured by the TMA method (Thermo-mechanical analysis). Specifically, a TMA device (TMA7100E manufactured by SII Nanotechnology Co., Ltd.) was used for measurement in tensile mode. To eliminate the effect of thermal strain on the test specimen, the test specimen was pulled with a load of 98 mN in the Y direction, heated from 30°C to 350°C at a heating rate of 20°C / min, and then cooled to room temperature. After that, the test specimen was pulled with a load of 98 mN in the Y direction, and heated from 30°C to 350°C at a heating rate of 10°C / min. A temperature displacement chart was obtained during this heating process. Then, the average thermal expansion coefficient between 50 and 125°C was calculated from the temperature displacement chart obtained at this time. If this average thermal expansion coefficient ("Y-CTE 50-125°C") was 17 ppm / °C or less, it was judged to be "pass."

[0208] [Glass Transition Temperature (Tg)] The outer copper foil of the evaluation substrate was etched across its entire surface, and the Tg of the obtained sample was measured using a viscoelastic spectrometer "DMS100" manufactured by Seiko Instruments Inc. Dynamic viscoelasticity measurement (DMA) was performed using a tensile module at a frequency of 1 Hz, and Tg was defined as the temperature at which tanδ showed a maximum when the temperature was raised from room temperature to 350°C at a heating rate of 5°C / min. The passing criterion for this test was Tg ≥ 260°C.

[0209] The results for each of the above evaluations are shown in Table 1.

[0210]

[0211] (Discussion) As can be seen from Table 1, in all the examples using the resin composition of the present invention, it was possible to obtain cured products that had low dielectric properties and a high glass transition temperature (Tg) while maintaining excellent moldability and a low coefficient of thermal expansion.

[0212] On the other hand, in Comparative Example 1, where the mass ratio of crosslinking agent (A) to phenylmaleimide (B) did not meet the requirements of the present invention and the proportion of crosslinking agent (A) was too low, the dielectric loss tangent and Tg were inferior and the acceptance criteria could not be met. On the other hand, in Comparative Example 2, where the proportion of crosslinking agent (A) was too high, the coefficient of thermal expansion became high.

[0213] This application is based on Japanese Patent Application No. 2025-056145, filed on 28 March 2025, the contents of which are included in this application.

[0214] In order to express the present invention, the invention has been adequately and sufficiently described above through embodiments with reference to specific examples and drawings, etc. However, those skilled in the art should recognize that it is easy to modify and / or improve the embodiments described above. Therefore, unless the modifications or improvements implemented by those skilled in the art fall outside the scope of the claims described in the claims, such modifications or improvements shall be interpreted as being included within the scope of the claims.

[0215] The present invention has broad industrial applicability in the technical fields related to electronic materials, electronic devices, optical devices, and the like.

Claims

1. A resin composition comprising a crosslinking agent (A) and a phenylmaleimide compound (B), wherein the crosslinking agent (A) is (i) an indene compound (A1) represented by the following formula (1), [In the formula (1), R １ are each independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, a thioaryloxy group having 6 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, and combinations thereof. F １ are each independently selected from a hydrogen atom, a vinylbenzyl group, and combinations thereof, and F １ at least one of which is a vinylbenzyl group. ] and (ii) at least one of an indene compound (A2) represented by the following formula (2), [In the formula (2), R １ are each independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, a thioaryloxy group having 6 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, and combinations thereof. F ２ are each independently selected from a hydrogen atom, a vinylbenzyl group, and a structure represented by the following formula (3), and F ２ at least one of which is a structure represented by the following formula (3). ] [In the formula (3), n, p and p' are each independently a value in the range of 0 to 50. R １ are each independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioalkoxy group having 1 to 5 carbon atoms, a thioaryloxy group having 6 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, and combinations thereof. F ２’ are each independently selected from a hydrogen atom and a vinylbenzyl group, and F in the aforementioned formula (2) ２ and F ２’ at least one of which is a vinylbenzyl group. F ４ is selected from a divalent group of the following formula (4), and combinations thereof. ] [In formula (4), Q is independently selected from a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and combinations thereof. R ２ Each is independently selected from a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a halogen atom, and combinations thereof. A resin composition in which the mass ratio of the crosslinking agent (A) to phenylmaleimide (B) is 5:95 to 95:

5.

2. The resin composition according to claim 1, wherein the phenylmaleimide compound (B) comprises a maleimide compound having at least one of an indan structure and an arylene structure bonded in an orientation to the meta position.

3. The resin composition according to claim 1, comprising a styrene copolymer (C).

4. The resin composition according to claim 3, wherein the styrene polymer (C) comprises a structural unit of the following formula (S-1) and at least one structural unit from among the structural units represented by the following formulas (S-2) to (S-4). [In formula (S-1), R １ ~R ３ Each of these independently represents either a hydrogen atom or an alkyl group, and R4 represents any group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, and an isopropenyl group. [In formulas (S-2), (S-3), and (S-4), R ５ ~R ２２ Each of these independently represents a group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, and an isopropenyl group.

5. The resin composition according to claim 3, wherein the weight-average molecular weight of the styrene polymer (C) is 1,000 to 300,000.

6. The resin composition according to claim 3, wherein the content of the styrene copolymer (C) is 5 parts by mass or more and 40 parts by mass or less, based on 100 parts by mass of the total of the crosslinking agent (A), the phenylmaleimide compound (B), and the styrene copolymer (C).

7. The resin composition according to claim 1, comprising an inorganic filler (D), wherein the content of the inorganic filler (D) is 35 parts by mass or more and 200 parts by mass or less, based on 100 parts by mass of the total of the crosslinking agent (A) and the phenylmaleimide compound (B).

8. A prepreg comprising a resin composition according to any one of claims 1 to 7 or a semi-cured product of the resin composition, and a fibrous substrate.

9. A resin-coated film comprising a resin layer containing the resin composition according to any one of claims 1 to 7 or a semi-cured product of the resin composition, and a support film.

10. A resin-coated metal foil comprising a resin layer containing the resin composition according to any one of claims 1 to 7 or a semi-cured product of the resin composition, and a metal foil.

11. A metal-clad laminate comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 7, and a metal foil.

12. A metal-clad laminate comprising an insulating layer containing a cured prepreg according to claim 8, and a metal foil.

13. A wiring board comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 7, and wiring.

14. A wiring board comprising an insulating layer containing a cured prepreg according to claim 8, and wiring.

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