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

Abstract

One aspect of the present invention relates to a resin composition containing a curable resin (A) having a group represented by formula (a), and a maleimide resin (B), wherein the maleimide resin (B) is a polymaleimide resin that is structured so as to have a benzene ring in a main chain connected by methylene groups and that has a partial structure represented by formula (T-1) and a partial structure represented by formula (T-2) that are chemically bonded thereto.

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] As such base materials, for example, a curable resin composition (Patent Document 1) has been reported that contains a specific vinyl compound in which the ends of a bifunctional phenylene ether oligomer having a polyphenylene ether skeleton in the molecule are vinylinated, and a specific bismaleimide compound having two or more maleimide groups in the molecule. Also, a resin composition (Patent Document 2) has been reported that contains a maleimide resin having a specific structure and a polyphenylene ether compound whose ends are modified with methacrylic groups.

[0004] Resin compositions containing polymaleimide compounds and modified polyphenylene ethers, as described in Patent Documents 1 and 2, can achieve a certain degree of low dielectric properties, but they suffer from problems such as poor moldability due to high melt viscosity during molding. Furthermore, these resin compositions also have the problem that their cured products do not sufficiently achieve a high glass transition temperature and low dielectric loss tangent.

[0005] Japanese Patent Publication No. 2009-161725 Japanese Patent Publication No. 2024-4392

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin composition that can obtain a cured product having low dielectric properties (Df) and a high glass transition temperature, and has good moldability. Another object of the present invention is to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board obtained by using the resin composition.

[0007] As a result of various studies, the present inventors have found that the above object can be achieved by the following constitution, and have completed the present invention through further studies.

[0008] That is, the resin composition according to one aspect of the present invention comprises a curable resin (A) having a group represented by the following formula (a), and a maleimide resin (B), (In formula (a), p represents 0 to 10; Ar represents an arylene group; R α to R γ each independently represent a hydrogen atom or an alkyl group) The maleimide resin (B) comprises a partial structure represented by the following formula (1), a partial structure represented by the formula (T-1) chemically bonded to the partial structure represented by the above formula (1), and a partial structure represented by the formula (T-2) chemically bonded to the partial structure represented by the above formula (1), and is a polymaleimide resin having the foregoing (In the above formula (1), R １３ each independently represent an alkyl group having 1 to 18 carbon atoms, m ２ represents an integer of 0 or more and 4 or less, n １ represents the average number of repeating units, two * each represent a bonding site, one bonding site is L in the following formula (T-1) １３ or L １４ is chemically bonded at the position, and the other bonding site is L in the following formula (T-2) １１ or L １２ represents that it is chemically bonded at the position.) (In the above formula (T-1) or (T-2), R １１ and R １５ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R １２ and R １４ each independently represent a hydrocarbon group having 1 to 18 carbon atoms, L１１ ~L １４ Each of these independently represents a bonding bond or a hydrogen atom, however, L １１ or L １２ At the position, it is chemically bonded to the substructure represented by formula (1), and L １３ or L １４ At this position, L is chemically bonded to the substructure represented by formula (1), and L is not chemically bonded to the substructure represented by formula (1). １１ ~L １４ is a hydrogen atom, m １ and m ３ Each of these represents 2. ) ), and is characterized by ).

[0009] Figure 1 is a schematic cross-sectional view showing an example of a prepreg according to an embodiment of the present invention. Figure 2 is a schematic cross-sectional view showing an example of a metal-clad laminate according to an embodiment of the present invention. Figure 3 is a schematic cross-sectional view showing an example of a wiring board according to an embodiment of the present invention. Figure 4 is a schematic cross-sectional view showing an example of a resin-coated metal foil according to an embodiment of the present invention. Figure 5 is a schematic cross-sectional view showing an example of a resin-coated film according to an embodiment of the present invention.

[0010] The following describes specific embodiments of the present invention, but the present invention is not limited to these embodiments.

[0011] [Resin Composition] The resin composition according to this embodiment comprises a curable resin (A) having a group represented by formula (a) above, and a maleimide resin (B). The maleimide resin (B) is a polymaleimide resin having a substructure represented by formula (1) above, a substructure represented by formula (T-1) that is chemically bonded to the substructure represented by formula (1), and a substructure represented by formula (T-2) that is chemically bonded to the substructure represented by formula (1).

[0012] With the above configuration, a cured product with high dielectric properties (especially dielectric loss tangent (Df)) and Tg can be obtained, and a resin composition with excellent moldability can be provided. Furthermore, according to the present invention, by using the resin composition, a prepreg, resin-coated film, resin-coated metal foil, metal-clad laminate, and wiring board having the above-mentioned excellent performance can be provided.

[0013] First, let's describe each component of the resin composition of this embodiment.

[0014] (Curable resin (A)) The resin composition of this embodiment is the following formula (a): It contains a curable resin (A) having a group represented by . In formula (a), p represents 0 to 10. Ar represents an arylene group. R α ~R γ They are independent of each other. That is, R α ~R γ The groups may be the same or different. α ~R γ ∫ represents a hydrogen atom or an alkyl group. In formula (a), if p is 0, it indicates that Ar is directly bonded to the polyphenylene ether.

[0015] The aforementioned arylene group is not particularly limited. Examples of such arylene groups include monocyclic aromatic groups such as phenylene groups, and polycyclic aromatic groups such as naphthalene rings. Furthermore, the arylene group also includes derivatives in which the hydrogen atom bonded to the aromatic ring is substituted with a functional group such as an alkenyl group, alkynyl group, formyl group, alkylcarbonyl group, alkenylcarbonyl group, or alkynylcarbonyl group.

[0016] The alkyl group is not particularly limited, but for example, alkyl groups having 1 to 18 carbon atoms are preferred, and alkyl groups having 1 to 10 carbon atoms are more preferred. Specifically, examples include methyl groups, ethyl groups, propyl groups, hexyl groups, and decyl groups.

[0017] The curable resin (A) is not particularly limited as long as it is a curable resin having the groups described above, but some specific thermosetting resins in preferred embodiments are listed below.

[0018] - Vinylbenzylindene compound, vinylbenzylfluorene compound, or mixture thereof (A-1) The curable resin (A) of this embodiment may contain a vinylbenzylindene compound, a vinylbenzylfluorene compound, or a mixture thereof (A-1) (hereinafter, these will also be collectively referred to simply as "compound (A-1)").

[0019] Specifically, compound (A-1) is (i) vinylbenzylindene represented by the following formula (I). [In formula (I), R １ , R ２ and R ３ Each of these is independently selected from a vinylbenzyl group, a hydrogen atom, a lower alkyl group, a thioalkoxy group having 1 to 5 carbon atoms, and an aryl group, and R １ , R ２ and R ３ At least one of them is a vinylbenzyl group. ４ (ii) Vinylbenzylfluorene represented by the following formula (II) [In formula (II), each R ５ Each of these is independently selected from a hydrogen atom, a halogen atom, a lower alkyl group, a carbon-1 to carbon-5 alkoxy group, a carbon-1 to carbon-5 thioalkoxy group, and an aryl group. x is an integer from 0 to 4. R ６ and R ７ Each of these is independently selected from a vinylbenzyl group, a hydrogen atom, a lower alkyl group, a thioalkoxy group having 1 to 5 carbon atoms, and an aryl group, and R ６ and R ７ (iii) a compound or mixture selected from (iii) a vinylbenzyl group, at least one of which is a vinylbenzyl group.

[0020] By including such a compound (A-1), a cured product with low dielectric properties (especially dielectric loss tangent (Df)) and high Tg can be obtained, and a resin composition with excellent moldability can also be obtained.

[0021] In this embodiment, the vinylbenzylindene represented by formula (I) is R １ , R ２ and R ３ Each is independently selected from a hydrogen atom and a vinylbenzyl group, and R １ , R ２ and R３ At least one of them is a vinylbenzyl group, R ４ Examples include compounds in which the element is selected from hydrogen atoms, halogen atoms, and lower alkyl groups.

[0022] In another embodiment, vinylbenzylindene represented by formula (I) is R １ , R ２ and R ３ Each is independently selected from a hydrogen atom and a vinylbenzyl group, and R １ , R ２ and R ３ At least one of them is a vinylbenzyl group, R ４ It may also be a compound in which the atom is a hydrogen atom.

[0023] In yet another embodiment, the vinylbenzylindene represented by formula (I) is R １ and R ２ is a vinylbenzyl group, R ３ is a hydrogen atom or a vinylbenzyl group, R ４ It may also be a compound in which the atom is a hydrogen atom.

[0024] To give a more specific example, vinylbenzylindene represented by the above formula (I) is 1,1,3-(2-vinylbenzyl)-1H-indene, 1,1,2-(3-vinylbenzyl)-1H-indene, 1,1,2-(4-vinylbenzyl)-1H-indene, 1,1-(2-vinylbenzyl)-1H-indene, 1,1-(3-vinylbenzyl)-1H-indene, 1,1-(4-vinylbenzyl)-1H-indene, 1,3-(2-vinylbenzyl)-1H-indene, 1, It may contain at least one selected from 3-(3-vinylbenzyl)-1H-indene; 1,3-(4-vinylbenzyl)-1H-indene, 1-(2-vinylbenzyl)-1H-indene, 1-(3-vinylbenzyl)-1H-indene, 1-(4-vinylbenzyl)-1H-indene, 3-(2-vinylbenzyl)-1H-indene, 3-(3-vinylbenzyl)-1H-indene, 3-(4-vinylbenzyl)-1H-indene, and mixtures thereof.

[0025] In yet another embodiment, the vinylbenzylindene represented by formula (I) is R １ , R ２ and R ３ is a vinylbenzyl group, R ４ It may also be a compound in which the atom is a hydrogen atom.

[0026] The vinylbenzylindene of this embodiment may consist of only one vinylbenzylindene or a mixture of multiple vinylbenzylindenes.

[0027] In one embodiment, the vinylbenzylindene mixture may be a mixture containing 50% by weight or more of at least one of 1,1,3-(2-vinylbenzyl)-1H-indene, 1,1,2-(3-vinylbenzyl)-1H-indene, and 1,1,2-(4-vinylbenzyl)-1H-indene, relative to the total amount of vinylbenzylindene; or a mixture containing less than 50% by weight of at least one of 1,1-(2-vinylbenzyl)-1H-indene, 1,1-(3-vinylbenzyl)-1H-indene, 1,1-(4-vinylbenzyl)-1H-indene, 1,3-(2-vinylbenzyl)-1H-indene, 1,3-(3-vinylbenzyl)-1H-indene, and 1,3-(4-vinylbenzyl)-1H-indene.

[0028] In another embodiment, the mixture may contain about 50% to about 85% by weight of 1,1,2-(4-vinylbenzyl)-1H-indene, about 10% to about 50% by weight of 1,1,2-(3-vinylbenzyl)-1H-indene, and 0% to about 10% by weight of 1,1,3-(2-vinylbenzyl)-1H-indene, where "by weight" refers to the weight percentage of the total vinylbenzylindene mixture.

[0029] The vinylbenzylindene mixture may further contain, with respect to the total amount of vinylbenzylindene, at least one of the following: 1-(2-vinylbenzyl)-1H-indene, 1-(3-vinylbenzyl)-1H-indene, 1-(4-vinylbenzyl)-1H-indene, 3-(2-vinylbenzyl)-1H-indene, 3-(3-vinylbenzyl)-1H-indene, and 3-(4-vinylbenzyl)-1H-indene in less than 5% by weight.

[0030] In this embodiment, the vinylbenzylfluorene represented by formula (II) is as follows: ５ Each is independently selected from a hydrogen atom, a halogen atom, and a lower alkyl group, R ６ and R ７ However, each is independently selected from a vinylbenzyl group, a hydrogen atom, and a lower alkyl group, and R ６ and R ７ Examples of compounds include those in which at least one of the groups is a vinylbenzyl group.

[0031] In another embodiment, the vinylbenzylfluorene represented by formula (II) is each R ５ is a hydrogen atom, R ６ and R ７ However, each may independently be a compound selected from a vinylbenzyl group and a hydrogen atom.

[0032] In another embodiment, the vinylbenzylfluorene represented by formula (II) is each R ５ is a hydrogen atom, R ６ and R ７ The compound may be a vinylbenzyl group.

[0033] In yet another embodiment, the vinylbenzylfluorene represented by formula (II) is selected from 9,9-bis-(o-vinylbenzyl)-9H-fluorene, 9,9-bis-(m-vinylbenzyl)-9H-fluorene, 9,9-bis-(p-vinylbenzyl)-9H-fluorene, and mixtures thereof.

[0034] In this embodiment, compound (A-1) may contain 0 to 100% by weight of vinylbenzylindene represented by formula (I) and 100 to 0% by weight of vinylbenzylfluorene represented by formula (II), based on the total amount of compound (A-1). In another embodiment, compound (A-1) may contain 10 to 90% by weight of vinylbenzylindene represented by formula (I) and 90 to 10% by weight of vinylbenzylfluorene represented by formula (II), based on the total amount of compound (A-1).

[0035] In yet another embodiment, compound (A-1) may contain 20 to 80% by weight, or 30 to 70% by weight, or 40 to 60% by weight of vinylbenzylindene represented by formula (I), and 80 to 20% by weight, or 70 to 30% by weight, or 60 to 40% by weight of vinylbenzylfluorene represented by formula (II), based on the total amount of compound (A-1).

[0036] In one specific example, compound (A-1) is: vinylbenzylindene represented by formula (I) above, comprising at least about 50% by weight, or at least about 60% by weight, or at least about 70% by weight, or at least about 80% by weight, of vinylbenzylindene, at least one of 1,1,3-(2-vinylbenzyl)-1H-indene, 1,1,2-(3-vinylbenzyl)-1H-indene and 1,1,2-(4-vinylbenzyl)-1H-indene; and less than about 50% by weight, or less than about 40% by weight, or less than about 30% by weight, or less than about 20% by weight, of 1,1-(2-vinylbenzyl)-1H-indene, 1,1-(3-vinylbenzyl)-1H-indene, 1,1-(4-vinylbenzyl) A vinylbenzylindene comprising at least one vinylbenzylindene from among 1,3-(2-vinylbenzyl)-1H-indene, 1,3-(3-vinylbenzyl)-1H-indene, and 1,3-(4-vinylbenzyl)-1H-indene; and at least one vinylbenzylindene from among 1,3-(2-vinylbenzyl)-1H-indene, 1,3-(2-vinylbenzyl)-1H-indene, 1,3-(3-vinylbenzyl)-1H-indene, and 3,3-(4-vinylbenzyl)-1H-indene in amounts of less than 5% by weight, or less than 3% by weight, or less than 1% by weight, or 0% by weight; The vinylbenzylfluorene represented by formula (II) above may include at least vinylbenzylfluorene selected from 9,9-bis-(2-vinylbenzyl)-9H-fluorene, 9,9-bis-(3-vinylbenzyl)-9H-fluorene, 9,9-bis-(4-vinylbenzyl)-9H-fluorene, and mixtures thereof.

[0037] - Polyphenylene ether compound (A-2) In another preferred embodiment, the thermosetting resin (A) may include a polyphenylene ether (PPE) compound (A-2) having at least one vinylbenzyl group at its molecular terminus. By using such a modified polyphenylene ether compound (A-2), the Tg and dielectric properties of the thermoset resin composition can be improved.

[0038] Examples of the vinylbenzyl group include a group exhibiting a styrene structure as shown in the following formula (2).

[0039]

[0040] More specifically, examples of the vinylbenzyl group include vinylbenzyl groups (ethenylbenzyl groups) such as p-ethenylbenzyl groups and m-ethenylbenzyl groups.

[0041] The polyphenylene ether compound (A-2) has a polyphenylene ether chain in its molecule. More specifically, examples of the polyphenylene ether compound (A-2) in this embodiment include the modified polyphenylene ether compound represented by the following formula (3) and the modified polyphenylene ether compound represented by the following formula (4). Furthermore, as the polyphenylene ether compound (A) in this embodiment, these modified polyphenylene ether compounds may be used individually or in combination.

[0042]

[0043]

[0044] In equations (3) and (4), R １７ ~R ２４ And R ２５ ~R ３２ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. Among these, hydrogen atoms and alkyl groups are preferred. １ and X ２Each independently represents a substituent having a carbon-carbon unsaturated double bond. A and B represent repeating units represented by the following formulas (5) and (6), respectively. Also, in formula (4), Y １ This refers to linear, branched, or cyclic hydrocarbons having 20 or fewer carbon atoms.

[0045]

[0046]

[0047] In equations (5) and (6), m and n represent values ​​from 0 to 20, respectively. ３３ ~R ３６ And R ３７ ~R ４０ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. Among these, hydrogen atoms and alkyl groups are preferred.

[0048] In formulas (5) and (6), it is preferable that m and n represent values ​​between 0 and 20, as described above. Furthermore, it is preferable that m and n represent values ​​such that the sum of m and n is between 1 and 30. Therefore, it is more preferable that m represents values ​​between 0 and 20, n represents values ​​between 0 and 20, and the sum of m and n is between 1 and 30.

[0049] In the above formula (4), Y １ As mentioned above, it is a linear, branched, or cyclic hydrocarbon with 20 or fewer carbon atoms. １ Examples include the base represented by the following formula (7).

[0050]

[0051] In the above formula (7), R ４１ and R ４２ Each of these independently represents either a hydrogen atom or an alkyl group. Examples of the alkyl group include a methyl group. Examples of the group represented by formula (7) include a methylene group, a methylmethylene group, and a dimethylmethylene group, among which the dimethylmethylene group is preferred.

[0052] In the above formula (3) and formula (4), X １ and X ２ are each independently a vinylbenzyl group as described above. In the modified polyphenylene ether compound represented by formula (3) and the modified polyphenylene ether compound represented by formula (4), X １ and X ２ may be the same or different substituents.

[0053] The modified polyphenylene ether compound (A-2) may be used alone, or two or more thereof may be used in combination.

[0054] In the present embodiment, the weight average molecular weight (Mw) of the modified polyphenylene ether compound (A-2) used as the thermosetting resin (A) is not particularly limited, but is, for example, preferably from 1000 to 5000, and more preferably from 1000 to 4000. Here, the weight average molecular weight may be one measured by a common molecular weight measurement method, and specific examples thereof include a value measured using gel permeation chromatography (GPC). Further, when the modified polyphenylene ether compound (A-2) has repeating units (s, m, n) in the molecule, it is preferable that these repeating units are numerical values such that the weight average molecular weight of the modified polyphenylene ether compound (A-2) falls within the above range.

[0055] When the weight-average molecular weight of the modified polyphenylene ether compound (A-2) is within this range, it possesses the excellent low dielectric properties of the polyphenylene ether skeleton, resulting in not only superior heat resistance of the cured product but also excellent moldability. This is thought to be due to the following: Compared to ordinary polyphenylene ether, if the weight-average molecular weight is within the range described above, it is relatively low molecular weight, so the heat resistance of the cured product tends to decrease. In this respect, the modified polyphenylene ether compound (A-2) according to this embodiment has a styrene structure at its terminals, so it has high reactivity, and it is thought that a cured product with sufficiently high heat resistance can be obtained. Furthermore, when the weight-average molecular weight of the modified polyphenylene ether compound (A-2) is within this range, it is high molecular weight compared to styrene and divinylbenzene, but relatively low molecular weight compared to general polyphenylene ether, so it is thought to have excellent moldability.

[0056] Furthermore, in this embodiment, the average number of substituents (number of terminal functional groups) at the molecular ends of the modified polyphenylene ether compound (A-2) used as the thermosetting resin (A) is not particularly limited. Specifically, it is preferably 1 to 5, and more preferably 1 to 3.

[0057] The number of terminal functional groups in the modified polyphenylene ether compound (A-2) can be expressed as a numerical value representing the average number of substituents per molecule of the modified polyphenylene ether compound present in one mole of the modified polyphenylene ether compound. This number of terminal functional groups can be measured, for example, by measuring the number of hydroxyl groups remaining in the obtained modified polyphenylene ether compound (A-2) and calculating the decrease from the number of hydroxyl groups in the polyphenylene ether before modification. This decrease from the number of hydroxyl groups in the polyphenylene ether before modification is the number of terminal functional groups. The number of hydroxyl groups remaining in the modified polyphenylene ether compound can be measured by adding a quaternary ammonium salt (tetraethylammonium hydroxide) that associates with hydroxyl groups to a solution of the modified polyphenylene ether compound and measuring the UV absorbance of the mixed solution.

[0058] The polyphenylene ether compound (A-2) used in the resin composition of this embodiment can be synthesized by known methods or a commercially available product can be used. Examples of commercially available products include "OPE-2st 1200" and "OPE-2st 2200" manufactured by Mitsubishi Gas Chemical Company, Inc.

[0059] As the thermosetting resin (A), the compound (A-1) and the modified polyphenylene ether compound (A-2) described above are preferably used from the viewpoint of obtaining low dielectric properties, high Tg, and excellent moldability, but these may be used alone or in combination.

[0060] - Polyfunctional vinyl aromatic copolymer (A-3) In addition to the compounds (A-1) and modified polyphenylene ether compounds (A-2) described above, a polyfunctional vinyl aromatic copolymer (A-3) having the group shown in formula (a) above can also be used as the thermosetting resin (A) in this embodiment.

[0061] The polyfunctional vinyl aromatic copolymer (A-3) preferably contains repeating units (a1) derived from a divinyl aromatic copolymer and repeating units (a2) derived from a monovinyl aromatic compound. Using such a polyfunctional vinyl aromatic copolymer (A-3) in the thermosetting resin (A) has the advantage of obtaining even lower dielectric properties.

[0062] The polyfunctional vinyl aromatic copolymer (A-3) preferably further contains a repeating unit represented by the following formula (11) as part of the repeating unit (a1) derived from the divinyl aromatic compound.

[0063]

[0064] In formula (11), R １ This represents an aromatic hydrocarbon group with 6 to 30 carbon atoms.

[0065] The aforementioned divinyl aromatic compound plays a role in forming a branched structure and making it polyfunctional, and also acts as a crosslinking component to provide heat resistance when the resulting soluble polyfunctional vinyl aromatic copolymer is thermoset.

[0066] Examples of divinyl aromatic compounds are not limited to aromatic compounds having two vinyl groups, but divinylbenzene (including each positional isomer or mixtures thereof), divinylnaphthalene (including each positional isomer or mixtures thereof), and divinylbiphenyl (including each positional isomer or mixtures thereof) are preferably used. These can be used individually or in combination of two or more. From the viewpoint of moldability, divinylbenzene (m-isomer, p-isomer, or mixtures of their positional isomers) is more preferred.

[0067] Examples of monovinyl aromatic compounds include styrene and other monovinyl aromatic compounds. However, styrene is essential, and it is desirable to use other monovinyl aromatic compounds in combination.

[0068] Styrene, as a monomer component, plays a role in imparting low dielectric properties and heat-resistant oxidative degradation to soluble polyfunctional vinyl aromatic copolymers, and as a chain transfer agent, it plays a role in controlling the molecular weight of the soluble polyfunctional vinyl aromatic copolymer.

[0069] Furthermore, monovinyl aromatic compounds other than styrene improve the solvent solubility and processability of soluble polyfunctional vinyl aromatic copolymers.

[0070] Examples of monovinyl aromatic compounds other than styrene include vinyl aromatic compounds other than styrene that have one vinyl group, such as vinylnaphthalene and vinylbiphenyl; and nuclear alkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene. Preferably, ethylvinylbenzene (including each positional isomer or mixtures thereof), ethylvinylbiphenyl (including each positional isomer or mixtures thereof), or ethylvinylnaphthalene (including each positional isomer or mixtures thereof) are used because they prevent gelation of soluble polyfunctional vinyl aromatic copolymers, have a high effect in improving solvent solubility and processability, are low in cost, and are readily available. More preferably, from the viewpoint of dielectric properties and cost, ethylvinylbenzene (m-isomer, p-isomer, or mixtures of their positional isomers) is used.

[0071] Furthermore, within the limits that do not impair the effects of the present invention, in addition to divinyl aromatic compounds and monovinyl aromatic compounds, one or more other monomer components such as trivinyl aromatic compounds, trivinyl aliphatic compounds, divinyl aliphatic compounds, and monovinyl aliphatic compounds may be used, and structural units (c) derived therefrom may be introduced into the soluble polyfunctional vinyl aromatic copolymer.

[0072] (Maleimide resin (B)) The maleimide resin (B) according to the present embodiment is a polymaleimide resin having a partial structure represented by the following formula (1), a partial structure represented by formula (T-1) chemically bonded to the partial structure represented by formula (1), and a partial structure represented by formula (T-2) chemically bonded to the partial structure represented by formula (1). In the above formula (1), R １３ each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and m ２ represents an integer of 0 or more and 4 or less, and n １ represents the average number of repeating units, two * each represent a bonding site, one bonding site is L in the following formula (T-1) １３ or L １４ is chemically bonded at the position of, and the other bonding site is L in the following formula (T-2) １１ or L １２ indicates that chemical bonding occurs at the position of.

[0073] In the above formula (T-1) or (T-2), R １１ and R １５ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. R １２ and R １４ each independently represent a hydrocarbon group having 1 to 18 carbon atoms. L １１ to L １４ each independently represent a bonding site or a hydrogen atom. Provided that at the position of L １１ or L １２ it is chemically bonded to the partial structure represented by formula (1), and at the position of L １３ or L １４ it is chemically bonded to the partial structure represented by formula (1), and L that is not chemically bonded to the partial structure represented by formula (1) １１ to L １４ is a hydrogen atom, m １ represents 2, and m ３ represents 2.

[0074] By including a maleimide resin (B) with this configuration, the resin exhibits high solubility in solvents and low dielectric loss tangent and high heat resistance during curing. The chemical structure of the maleimide resin (B) in this embodiment has only one bonding site each at the ortho and para positions of the benzene ring to which the maleimide group is bonded. As a result, a polymaleimide resin with linearly elongated chains can be obtained, making molecular weight control easy and enabling a balance between heat resistance, low dielectric properties, and solvent solubility.

[0075] In equation (1) above, the two *s each represent a bonding hand. And one of the two bonding hands is L in equation (T-1) above. １３ or L １４ A chemical bond is formed at the position. The other bond is L in formula (T-2) above. １１ or L １２ Chemical bonding occurs at the position. Therefore, the maleimide resin (B) of this embodiment has a structural unit in which a substructure represented by formula (T-1) and a substructure represented by formula (T-2) are linked by a substructure represented by formula (1), and the substructure represented by formula (1) is chemically bonded to the maleimide group on the benzene ring in formulas (T-1) and (T-2) at the para position or one ortho position.

[0076] Note that in formula (1) above, n １ If the number is 2 or more, there are multiple R １３ They may be the same or different from each other. ２ If the number is 2 or more, there are multiple R １３ They may be the same as or different from each other.

[0077] In the above formula (1), R １３ Each of these independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrocarbon group having 1 to 6 carbon atoms. ２ If R is an integer greater than or equal to 2, there are multiple R's. １３ These may be the same or different from each other. Preferred R in formula (1) １３As such, linear alkyl groups are preferred, and more preferably methyl groups, ethyl groups, propyl groups, isopropyl groups, n-butyl groups, isobutyl groups, sec-butyl groups, tert-butyl groups, n-pentyl groups, isopentyl groups, tert-pentyl groups, or neopentyl groups. In this specification, the "reaction raw materials" described later refer to precursors for obtaining the target polymaleimide resin or its precursor compound (e.g., an intermediate amine compound (γ) in which aromatic amine compounds (α) are linked to each other via structural units derived from a compound (β) having a benzyl ether skeleton) by a chemical reaction. １３ The bonded benzene ring can be the benzene ring of a compound (β) having a benzyl ether skeleton.

[0078] In the above formula (1), m ２ R represents an integer between 0 and 4, preferably an integer less than or equal to 2, and more preferably 2. １３ In a benzene ring to which R is bonded, if the 1st and 3rd positions are bonded by a methylene group, then the 4th and 6th positions are R １３ It is preferable that each of them is combined. In formula (1) above, n １ This represents the average number of repeating units, and from the viewpoint of the viscosity of the resulting polymaleimide resin, it is preferably 0 to 50, preferably 0 to 30, and preferably 0 to 15. This average number of repeating units can be calculated from the charge ratio or NMR, etc.

[0079] In this embodiment, the maleimide resin (B) preferably contains 1 to 99% by mass of the substructure represented by formula (1) based on the total amount (100% by mass) of the maleimide resin (B), more preferably 3 to 97% by mass, and even more preferably 5 to 95% by mass.

[0080] In the above formula (T-1), R １５ Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. Particularly preferred R １５These can be hydrogen atoms or linear alkyl groups having 1 to 6 carbon atoms. ３ Since is 2, the two R １５ They may be the same as or different from each other.

[0081] In the above formula (T-1), R １４ Each of these independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrocarbon group having 1 to 6 carbon atoms. Particularly preferred R １４ These can be linear alkyl groups having 1 to 6 carbon atoms.

[0082] By allowing a bonding site with the substructure represented by formula (1) at the ortho position (position 6) of the benzene ring in formula (T-1) or formula (T-2) above, higher solubility in solvents is achieved, and superior low dielectric loss tangent and high heat resistance are exhibited during curing. Note that R in formula (T-1) １４ The benzene ring to which it is bonded can be the benzene ring of the aromatic amine compound (α).

[0083] In the above formula (T-1), L １３ or L １４ Each of these independently represents a bond or a hydrogen atom. However, L １３ or L １４ At least one of the positions of the substructure is chemically bonded to the substructure represented by formula (1) and the substructure represented by formula (T-1). In addition, L does not chemically bond to the substructure represented by formula (1). １３ or L １４ L is a hydrogen atom. １３ and L １４ A substructure represented by formula (1) may be chemically bonded to each of the two locations.

[0084] In the above formula (T-2), R １１ Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. Preferred R １１ These can be hydrogen atoms or linear alkyl groups having 1 to 6 carbon atoms. １Since is 2, the two R １１ They may be the same as or different from each other.

[0085] In the above formula (T-2), R １２ Each of these independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrocarbon group having 1 to 6 carbon atoms. Preferred R １２ In this context, it represents a linear alkyl group with 1 to 6 carbon atoms.

[0086] Note that R in equation (T-2) １２ The benzene ring to which it is bonded can be the benzene ring of the aromatic amine compound (α).

[0087] In the above formula (T-2), L １１ or L １２ Each of these independently represents a bond or a hydrogen atom. However, L １１ or L １２ At least one of the positions of the substructure is chemically bonded to the substructure represented by formula (1) and the substructure represented by formula (T-2). In addition, L does not chemically bond to the substructure represented by formula (1). １１ or L １２ L is a hydrogen atom. １１ and L １２ A substructure represented by formula (1) may be chemically bonded to each of the two locations.

[0088] In this embodiment, the maleimide resin (B) preferably contains 1 to 99% by mass of the substructure represented by formula (T-1) based on the total amount (100% by mass) of the maleimide resin (B), more preferably 3 to 97% by mass, and even more preferably 5 to 95% by mass.

[0089] In this embodiment, the maleimide resin (B) preferably contains 1 to 99% by mass of the substructure represented by formula (T-2) based on the total amount (100% by mass) of the maleimide resin (B), more preferably 3 to 97% by mass, and even more preferably 5 to 95% by mass.

[0090] The number-average molecular weight (Mn) of the maleimide resin (B) in this embodiment is preferably in the range of 200 to 1500, and more preferably in the range of 300 to 800. The weight-average molecular weight (Mw) of the polymaleimide resin is preferably in the range of 280 to 2000, and more preferably in the range of 330 to 1200.

[0091] In this embodiment, the maleimide resin (B) is preferable in terms of its excellent solvent solubility, heat resistance, and low dielectric loss tangent, and therefore has a molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn)) calculated from gel permeation chromatography (GPC) measurement in the range of 1.01 to 4.0, more preferably 1.05 to 2.0, and even more preferably 1.10 to 1.8.

[0092] The number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn)) of maleimide resin (B) were measured using gel permeation chromatography (hereinafter abbreviated as "GPC").

[0093] The maleimide resin (B) of this embodiment is not particularly limited in its manufacturing method and may be manufactured in any way as long as it has a substructure represented by formula (1), a substructure represented by formula (T-1) that is chemically bonded to the substructure represented by formula (1), and a substructure represented by formula (T-2) that is chemically bonded to the substructure represented by formula (1). A preferred embodiment of the method for manufacturing the maleimide resin (B) is to use an aromatic amine compound (α) represented by the following formula (a-1), a compound having a benzyl ether skeleton (β), and maleic anhydride as reaction raw materials. In the above formula (a-1), R ａ１ and R ａ２ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R １ R represents a hydrocarbon group with 1 to 18 carbon atoms. ２ and R ３ Each of these independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.

[0094] (Curing agent (C)) The resin composition of this embodiment may further contain a curing agent (C) that can react with at least one of the curable resin (A) or the maleimide resin (B). Such a configuration has the advantage of obtaining greater heat resistance in the thermocured resin composition. The curing agent is not particularly limited as long as it is a curing agent that can react with at least one of the curable resin (A) or the maleimide resin (B) to cure the resin composition. Examples of the curing agent include curing agents that have at least one functional group in their molecule that contributes to the reaction with the polymer.

[0095] More specifically, examples of the curing agent (C) include styrene derivatives, compounds having an acryloyl group in the molecule, compounds having a methacryloyl group in the molecule, compounds having a vinyl group in the molecule, compounds having an allyl group in the molecule, compounds having a maleimide group in the molecule, and compounds having an acenaphthylene structure in the molecule.

[0096] Examples of the styrene derivatives include divinylbenzene and 1,2-bis(4-vinylphenyl)ethane.

[0097] The compound having an acryloyl group in its molecule is an acrylate compound. Examples of acrylate compounds include monofunctional acrylate compounds having one acryloyl group in their molecule, and polyfunctional acrylate compounds having two or more acryloyl groups in their molecule. Examples of monofunctional acrylate compounds include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. Examples of polyfunctional acrylate compounds include tricyclodecanedimethanol diacrylate.

[0098] A compound having a methacryloyl group in its molecule is a methacrylate compound. Examples of methacrylate compounds include monofunctional methacrylate compounds having one methacryloyl group in their molecule, and polyfunctional methacrylate compounds having two or more methacryloyl groups in their molecule. Examples of monofunctional methacrylate compounds include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Examples of polyfunctional methacrylate compounds include tricyclodecanedimethanol dimethacrylate.

[0099] A compound having a vinyl group in its molecule is a vinyl compound. Examples of vinyl compounds include monofunctional vinyl compounds (monovinyl compounds) having one vinyl group in their molecule, and polyfunctional vinyl compounds having two or more vinyl groups in their molecule. Examples of polyfunctional vinyl compounds include polybutadiene.

[0100] The allyl compounds are compounds having an allyl group in their molecule, and examples include triallyl isocyanurate compounds such as triallyl isocyanurate (TAIC), diallyl bisphenol compounds, allyl epoxy compounds, and diallyl phthalate (DAP).

[0101] The compound having an acenaphthylene structure in its molecule is an acenaphthylene compound. The acenaphthylene compound may be a monofunctional acenaphthylene compound having one acenaphthylene structure in its molecule, or a polyfunctional acenaphthylene compound having two or more acenaphthylene structures in its molecule.

[0102] The compound having a maleimide group in its molecule is a maleimide compound, and the maleimide-based curing agent used in this embodiment can be a maleimide compound other than the maleimide resin (B) described above. Examples of the maleimide compound include a monofunctional maleimide compound having one maleimide group in its molecule, a polyfunctional maleimide compound having two or more maleimide groups in its molecule, and a modified maleimide compound.

[0103] In a preferred embodiment, the curing agent (C) comprises at least one selected from the group consisting of a maleimide compound having an indan structure in its molecule, a maleimide compound having an arylene structure bonded in a meta position, and a maleimide compound having an indan structure and an arylene structure bonded in a meta position in its molecule.

[0104] In this specification, the indane structure of a maleimide compound may include, for example, the indane structure represented by the following formula (C-1).

[0105]

[0106] In formula (C-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 a C1-C10 alkyl group, a C1-C10 alkyloxy group (alkoxy 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 (thiol group). r represents 0-3.

[0107] r is the average value of the degree of substitution of Rb, and a smaller value is preferable, specifically, it is preferable that it be 0. That is, in the benzene ring to which Rb can be bonded, it is preferable that a hydrogen atom is bonded at the position to which Rb can be bonded. When r is 1 to 3, it is preferable that Rb is at least one selected from the group consisting of alkyl groups having 1 to 4 carbon atoms, cycloalkyl groups having 3 to 6 carbon atoms, and aryl groups having 6 to 10 carbon atoms.

[0108] In maleimide compounds having an arylene structure in the molecule that is oriented and bonded at the meta position, examples of the arylene structure include an arylene structure in which a structure containing a maleimide group is bonded at the meta position (an arylene structure in which a structure containing a maleimide group is substituted at the meta position). Examples of the arylene structure include m-arylene groups such as m-phenylene groups and m-naphthylene groups.

[0109] Maleimide compounds having an indan structure and an arylene structure oriented and bonded to the meta position in their molecule include, specifically, maleimide compounds represented by the following formulas (8) to (10).

[0110]

[0111] In equation (8), n represents a range of 0.95 to 10.

[0112] In equation (9), n represents a range of 0.95 to 10.

[0113] In equation (10), n represents a range of 0.95 to 10.

[0114] As maleimide compounds having an indan structure and an arylene structure bonded in a meta position as described above, commercially available products can be used. For example, the solid content in NE-X-9470S manufactured by DIC Corporation is one such example. An example of a maleimide compound having an arylene structure bonded in a meta position is the solid content in MIR-5000-60T manufactured by Nippon Kayaku Co., Ltd.

[0115] In addition to the above-mentioned maleimide compounds, aromatic maleimide compounds, aliphatic maleimide compounds, and modified maleimide compounds may also be used as the curing agent (C). Specific examples of aromatic and aliphatic maleimide compounds include phenyl maleimide compounds such as 4,4'-diphenylmethanebismaleimide, polyphenylmethanemaleimide, m-phenylenebismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, and biphenylaralkyl polymaleimide compounds, as well as N-alkylbismaleimide compounds having an aliphatic skeleton. Examples of the modified maleimide compounds include modified maleimide compounds in which part of the molecule is modified with an amine compound, and modified maleimide compounds in which part of the molecule is modified with a silicone compound.

[0116] Commercially available maleimide compounds can be used, for example, MIR-3000-70MT from Nippon Kayaku Co., Ltd., BMI-4000, BMI-5100, BMI-2300, BMI-TMH from Yamato Kasei Kogyo Co., Ltd., and BMI-689, BMI-1500, BMI-3000J, BMI-5000 from Designer Molecules Inc.

[0117] As the hardening agent (C), any of the above-mentioned hardening agents may be used individually, or two or more may be used in combination.

[0118] (Content ratio / content) In the resin composition of this embodiment, the ratio of thermosetting resin (A) to maleimide resin (B) is preferably 5:95 to 95:5 by mass ratio. This is considered to make the above-mentioned effects more reliable. A more preferable range for the mass ratio is 10:90 to 90:10.

[0119] The content of the thermosetting resin (A) in the resin composition of this embodiment is preferably 5 to 80 parts by mass relative to 100 parts by mass of the total resin components in the resin composition, i.e., the thermosetting resin (A) and maleimide resin (B) (including the curing agent (C) and styrene-based polymer polymers described later, if any). This is considered to allow the above-mentioned effects to be obtained more reliably. A more preferable range for the content is 10 to 60 parts by mass.

[0120] Furthermore, the content of maleimide resin (B) in the resin composition of this embodiment is preferably 5 to 80 parts by mass with respect to 100 parts by mass of the total resin components in the resin composition, i.e., thermosetting resin (A) and maleimide resin (B) (including curing agent (C) and styrene-based polymer polymers described later, if any). This is considered to allow for more reliable acquisition of the above-mentioned effects. A more preferable range for the content is 10 to 70 parts by mass.

[0121] When the resin composition of this embodiment contains a curing agent (C), its content is preferably 5 to 40 parts by mass relative to 100 parts by mass of the total of the resin components in the resin composition, i.e., the thermosetting resin (A), maleimide resin (B), and curing agent (C) (including styrene-based polymer polymers, etc., if described later). This is considered to allow for more reliable acquisition of the effects described above. A more preferable range for the content is 10 to 30 parts by mass.

[0122] (Styrene polymer / Acrylic polymer) The resin composition of this embodiment may further contain at least one of a styrene polymer that is solid at 25°C and an acrylic polymer that is solid at 25°C. It is believed that this will allow for even lower dielectric properties (low dielectric loss tangent) in the cured product.

[0123] Examples of styrene polymers that can be used in this embodiment include styrene polymers that are solid at 25°C and can be used as resins in resin compositions used to form insulating layers in metal-clad laminates and wiring boards, etc.

[0124] Specific examples of styrene copolymers include copolymers obtained by copolymerizing one or more monomers containing styrene (styrene monomers) with one or more other monomers copolymerizable with styrene monomers. The styrene copolymer may be a random copolymer or a block copolymer. Examples of the block copolymer include a binary copolymer of structural units (repeating units) derived from the styrene monomer and structural units (repeating units) derived from the other copolymerizable monomers, and a ternary copolymer 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. The styrene polymer may also be a hydrogenated styrene copolymer obtained by hydrogenating the styrene copolymer as described above.

[0125] 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.

[0126] Furthermore, it is preferable that the styrene polymer has both ethylene and butylene structural units in its molecule.

[0127] The ethylene structural unit is not particularly limited, but examples include structural units (repeating units) derived from other copolymerizable monomers that have an ethylene structure. The ethylene structural unit is a structure derived from a 1,4-bond of a conjugated diene monomer (conjugated dienes), and the atom or group bonded to the carbon of the -C-C-bond in the main chain is a hydrogen atom or a methyl group. Specific examples of the conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-cyclohexadiene. Therefore, the ethylene structural units specifically include structural units having an ethylene structure among the structural units derived from the conjugated dienes, and more specifically, structural units having an ethylene structure (1,4-addition structural units) among the structural units (repeating units) derived from 1,3-butadiene.

[0128] The butylene structural unit is not particularly limited, but examples include structural units (repeating units) derived from other copolymerizable monomers that have a butylene structure. The butylene structural unit is at least one of a structure derived from a 1,2-bond of a conjugated diene monomer (conjugated dienes) and a structure derived from a 3,4-bond of a conjugated diene monomer (conjugated dienes), and at least one of the atoms or groups bonded to the carbon of the -C-C-bond of the main chain is a side chain having two or more carbon atoms. Therefore, the butylene structural unit specifically includes structural units derived from the conjugated dienes that have a butylene structure, and more specifically, structural units (repeating units) derived from 1,3-butadiene that have a butylene structure (at least one of a 1,2-addition structural unit and a 3,4-addition structural unit). The butylene structural unit may be, for example, a hydrogenated structural unit. In styrene-based polymers, it is believed that a higher proportion of butylene structural units allows for a lower coefficient of thermal expansion.

[0129] The styrene polymer may contain structural units (repeating units) derived from other copolymerizable monomers other than the ethylene structural unit and the butylene structural unit. Such other copolymerizable monomers are not particularly limited, but examples include olefins such as α-pinene, β-pinene, and dipentene, and non-conjugated dienes such as 1,4-hexadiene and 3-methyl-1,4-hexadiene.

[0130] Specific examples of styrene-based polymers include methylstyrene (ethylene / butylene) methylstyrene copolymer, methylstyrene (ethylene-ethylene / propylene) methylstyrene copolymer, styrene isoprene copolymer, styrene isoprene styrene copolymer, styrene (ethylene / butylene) styrene copolymer, styrene (ethylene-ethylene / propylene) styrene copolymer, styrene butadiene styrene copolymer, and styrene (butadiene / butylene) styrene copolymer. Furthermore, the styrene-based polymer may be a styrene-based polymer in which at least a portion of the styrene-based copolymer has been hydrogenated. In addition, the styrene-based polymer may be a styrene-based polymer in which at least a portion of the styrene-based polymer has been acid-modified.

[0131] The styrene polymer preferably has a weight-average molecular weight of 10,000 to 300,000, and more preferably 10,000 to 200,000. In this specification, the weight-average molecular weight can be any value measured by a general molecular weight measurement method, specifically, a value measured using gel permeation chromatography (GPC).

[0132] The styrene-based polymer may be one of the exemplified styrene-based polymers used alone, or two or more may be used in combination.

[0133] Examples of acrylic polymers that can be used in this embodiment include acrylic polymers that are solid at 25°C and can be used as resins in resin compositions used to form insulating layers in metal-clad laminates and wiring boards, etc.

[0134] Examples of acrylic polymers that can be used in this embodiment include acrylic block copolymers and acrylic random copolymers. The acrylic block copolymer is not particularly limited as it includes a structural unit (c1) represented by the following formula (A-I) and a structural unit (c2) represented by the following formula (A-II), and has a number average molecular weight of 10,000 to 300,000.

[0135]

[0136]

[0137] In the structural unit (c2), Y is not particularly limited as long as it is a hydrocarbon group having 4 or more carbon atoms. Examples of the hydrocarbon group include butyl group, hexyl group, pentyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, lauryl group, stearyl group, docosyl group, isostearyl group, 1-methylheptyl group, 2-ethylhexyl group, phenoxyethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2-hydroxybutyl group, 4-hydroxybutyl group, 2-carboxyethyl group, isobornyl group, and isoamyl group. Among these hydrocarbon groups, butyl group and 2-ethylhexyl group are preferred. The structural unit (c2) may contain these hydrocarbon groups individually or in combination of two or more. The structural unit (c2) is preferably a structural unit derived from butyl acrylate and a structural unit derived from 2-ethylhexyl acrylate. The structural unit (c1) is derived from methyl methacrylate. Therefore, the acrylic block copolymer is preferably a block copolymer of a structural unit derived from methyl methacrylate as the structural unit (c1) and at least one of a structural unit derived from butyl acrylate and a structural unit derived from 2-ethylhexyl acrylate as the structural unit (c2). Examples of the block copolymer include a diblock product of the structural unit (c1) and the structural unit (c2), and a triblock product of the structural unit (c1), the structural unit (c2), and the structural unit (c1), with the triblock product being preferred. Specifically, the acrylic block copolymer is more preferably a block copolymer of methyl methacrylate and butyl acrylate, and more preferably a triblock product of methyl methacrylate, butyl acrylate, and methyl methacrylate. Furthermore, the structural unit (c1) preferably becomes a hard segment in the acrylic block copolymer, and its glass transition temperature is preferably, for example, 100 to 120°C.Furthermore, the structural unit (c2) is a soft segment in the acrylic block copolymer, and its glass transition temperature is preferably -60 to -40°C, and more preferably -50 to -40°C.

[0138] The acrylic block copolymer may contain the structural unit (c1) and the structural unit (c2), and may also contain structural units other than the structural units (c1) and the structural unit (c2) (other structural units) (c3). The other structural units are not particularly limited and include, for example, structural units derived from methacrylic acid esters other than methyl methacrylate, structural units derived from methyl acrylate, structural units derived from ethyl acrylate, structural units derived from butyl acrylate, and structural units derived from styrene. Furthermore, examples of structural units derived from methacrylic acid esters other than methyl methacrylate include structural units derived from ethyl methacrylate, structural units derived from butyl methacrylate, and structural units derived from propyl methacrylate.

[0139] The number-average molecular weight of the acrylic block copolymer is 10,000 or more, preferably 30,000 or more, more preferably 40,000 or more, preferably 300,000 or less, and more preferably 200,000 or less. The acrylic block copolymer may be solid at 25°C or liquid at 25°C, but is preferably solid at 25°C. The number-average molecular weight of the acrylic block copolymer is preferably a number-average molecular weight that is solid at 25°C. Here, the number-average molecular weight can be measured by a general molecular weight measurement method, specifically, a value measured using gel permeation chromatography (GPC).

[0140] The acrylic random copolymer preferably has a structure represented by, for example, the following formulas (A-III), (A-IV), and (A-V).

[0141]

[0142]

[0143] In the above equations (A-III) to (A-V), x, y, and z represent mole fractions, and satisfy x + y + z ≤ 1, 0 < x ≤ 0.2, 0.6 ≤ y ≤ 0.95, and 0.05 ≤ z ≤ 0.2.

[0144] In the above formula (A-IV), R １ R is a hydrogen atom or a methyl group. ２ It contains at least one of a hydrogen atom, an alkyl group, a glycidyl group, and an epoxidized alkyl group, specifically a glycidyl group and an epoxidized alkyl group.

[0145] In the above formula (A-V), R ３ R is a hydrogen atom or a methyl group. ４ Ph (phenyl group), -COOCH ２ Ph or -COO(CH ２ ) ２ It is Ph.

[0146] Preferably, the main chain of the acrylic polymer has a structure represented by at least one formula (A-III), a structure represented by at least one formula (A-IV), and a structure represented by at least one formula (A-V).

[0147] When the main chain of an acrylic random copolymer has structures represented by formulas (A-III), (A-IV), and (A-V), the order in which the structures represented by formulas (A-III), (A-IV), and (A-V) are arranged is not particularly limited. In this case, the structures represented by formula (A-III) may or may not be continuous in the main chain of the acrylic random copolymer, the structures represented by formula (A-IV) may or may not be continuous, and the structures represented by formula (A-V) may or may not be continuous.

[0148] Here, in the above formula (A-IV) R ２ However, we will provide further explanation regarding the meaning of including at least one of the hydrogen atom, alkyl group, glycidyl group, and epoxidized alkyl group, specifically the glycidyl group and the epoxidized alkyl group. As a premise, R in a structure represented by one formula (A-IV)２ There is only one. The acrylic random copolymer will be explained separately for cases where it has only one structure represented by formula (A-IV) and cases where it has two or more structures.

[0149] In the former case, that is, when the acrylic random copolymer has a structure represented by one formula (A-IV), R ２ This is a glycidyl group or an epoxidized alkyl group.

[0150] In the latter case, that is, when the acrylic random copolymer has a structure represented by two or more formulas (A-IV), R in at least one of the structures represented by formula (A-IV) ２ R is a glycidyl group or an epoxidized alkyl group, and R is in the structure represented by the remaining formula (A-IV). ２ R is a hydrogen atom or an alkyl group. ２ However, since it is a glycidyl group or an epoxidized alkyl group, R in the entire structure represented by formula (A-IV) ２ However, a glycidyl group or an epoxidized alkyl group may also be used.

[0151] The structure represented by the above formula (A-V) is Ph (phenyl group), -COOCH ２ Ph, -COO(CH ２ ) ２ It has a pH. Ph, -COOCH ２ Ph, -COO(CH ２ ) ２ Since pH is thermally stable, it is believed that the strength of the cured resin composition can be increased, thereby improving the heat resistance of laminates (metal-clad laminates and wiring boards).

[0152] The weight-average molecular weight of the acrylic random copolymer is 10,000 or more, preferably between 10,000 and 900,000, and more preferably between 10,000 and 600,000. The acrylic random copolymer may be solid or liquid at 25°C, but is preferably solid at 25°C. The weight-average molecular weight of the acrylic random copolymer is preferably a weight-average molecular weight that is solid at 25°C. Here, the weight-average molecular weight can be measured by a general molecular weight measurement method, specifically, a value measured using gel permeation chromatography (GPC).

[0153] When the resin composition of this embodiment includes a styrene polymer and / or an acrylic polymer, the total content thereof is preferably 5 to 40 parts by mass relative to 100 parts by mass of the total of the resin components in the resin composition, i.e., the thermosetting resin (A), maleimide resin (B), and styrene copolymer and / or acrylic polymer (including the curing agent (C), if present). This is considered to allow for more reliable acquisition of the effects described above. A more preferable range for the content is 10 to 30 parts by mass.

[0154] (Inorganic Filler) The resin composition of this embodiment may contain an inorganic filler as needed, to the extent that it does not impair the effects of the present invention. This is thought to further reduce the thermal expansion coefficient of the cured resin composition. The inorganic filler 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 fillers include fillers made of at least one selected from the group consisting of solid silica such as spherical silica, hollow silica, metal oxides such as alumina, titanium oxide, and 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 type of inorganic filler may be used alone, or two or more types may be used in combination. The filler may be used as is, or a filler that has been surface-treated with a silane coupling agent or the like may be used.

[0155] The inorganic filler content is preferably 5 parts by mass or more and 200 parts by mass or less per 100 parts by mass of the resin component containing the thermosetting resin (A) and maleimide resin (B). 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 20 parts by mass or more and 150 parts by mass or less.

[0156] (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 thermosetting resin (A), maleimide resin (B), curing agent (C), and organic components other than the styrene polymer, flame retardants, reaction initiators, curing accelerators, catalysts, polymerization retardants, polymerization inhibitors, dispersants, leveling agents, coupling agents, defoaming agents, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes and pigments, and additives such as lubricants.

[0157] 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. Furthermore, in fields where halogen-free is required, it is preferable to use a flame retardant containing phosphorus (phosphorus-based flame retardant). 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.

[0158] 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.

[0159] As described above, the resin composition of this embodiment may further contain a polymerization inhibitor. 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.

[0160] 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.

[0161] (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.

[0162] The resin composition according to this embodiment is a resin composition that yields a cured product with low dielectric properties and a high Tg, and also exhibits excellent moldability. 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 excellent heat resistance.

[0163] (Manufacturing Method) The method for manufacturing the resin composition of this embodiment is not particularly limited, and examples include mixing a thermosetting resin (A), a maleimide resin (B), and other resin components as needed, and then adding an inorganic filler as needed. Specifically, when obtaining a varnish-like composition containing an organic solvent, the method described in the prepreg description below can be used.

[0164] 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.

[0165] [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.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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).

[0171] 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 the above-described embodiment is often prepared in a varnish-like state and used as a resin varnish, as described above.

[0172] 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. The glass cloth used in this embodiment is not particularly limited, but examples include low dielectric constant glass cloths such as E glass, S glass, NE glass, Q glass, and L glass. As for the flattening process, for example, a method of continuously pressing the glass cloth with a press roll at an appropriate pressure to flatten the yarn can be used. The thickness of the fibrous base material that is generally used is, for example, 0.01 mm or more and 0.3 mm or less.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] [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.

[0177] 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.

[0178] 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.

[0179] [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.

[0180] 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.

[0181] 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).

[0182] [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.

[0183] 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.

[0184] 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.

[0185] Any metal foil used in metal-clad laminates can be used without limitation. Examples of metal foils include copper foil and aluminum foil.

[0186] 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.

[0187] 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.

[0188] [Resin-coated film] Figure 5 is a schematic cross-sectional view showing an example of a resin-coated film 41 according to this embodiment.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] This specification discloses various aspects of technology as described above, but the main technologies are summarized below.

[0197] A resin composition according to a first aspect of the present invention comprises a curable resin (A) having a group represented by formula (a) and a maleimide resin (B), wherein the maleimide resin (B) is a polymaleimide resin having a substructure represented by formula (1), a substructure represented by formula (T-1) chemically bonded to the substructure represented by formula (1), and a substructure represented by formula (T-2) chemically bonded to the substructure represented by formula (1).

[0198] The resin composition according to the second aspect of the present invention is the resin composition according to the first aspect, wherein the maleimide resin (B) is reacted with an aromatic amine compound represented by the above formula (a-1), a compound having a benzyl ether skeleton, and maleic anhydride as reaction raw materials.

[0199] A third aspect of the present invention is a resin composition of the first or second aspect, wherein the curable resin (A) comprises a compound or mixture (A-1) selected from (i) vinylbenzylindene represented by formula (I), (ii) vinylbenzylfluorene represented by formula (II), and (iii) mixtures thereof.

[0200] A fourth aspect of the present invention is a resin composition in the third aspect, wherein the vinylbenzylfluorene is at least one selected from 9,9-bis-(o-vinylbenzyl)-9H-fluorene, 9,9-bis-(m-vinylbenzyl)-9H-fluorene, 9,9-bis-(p-vinylbenzyl)-9H-fluorene, and mixtures thereof.

[0201] A fifth aspect of the present invention is a resin composition in which, in the resin composition of the third aspect, the vinylbenzylindene is 1,1,3-(2-vinylbenzyl)-1H-indene, 1,1,2-(3-vinylbenzyl)-1H-indene, 1,1,2-(4-vinylbenzyl)-1H-indene, 1,1-(2-vinylbenzyl)-1H-indene, 1,1-(3-vinylbenzyl)-1H-indene, 1,1-(4-vinylbenzyl)-1H-indene, 1,3-(2-vinylbenzyl)-1 It comprises at least one selected from H-indene, 1,3-(3-vinylbenzyl)-1H-indene; 1,3-(4-vinylbenzyl)-1H-indene, 1-(2-vinylbenzyl)-1H-indene, 1-(3-vinylbenzyl)-1H-indene, 1-(4-vinylbenzyl)-1H-indene, 3-(2-vinylbenzyl)-1H-indene, 3-(3-vinylbenzyl)-1H-indene, 3-(4-vinylbenzyl)-1H-indene, and mixtures thereof.

[0202] A resin composition according to a sixth aspect of the present invention is a resin composition according to any of the first to fifth aspects, wherein the curable resin (A) comprises a polyphenylene ether compound (A-2) having at least one vinylbenzyl group at its molecular terminus.

[0203] A resin composition according to the seventh aspect of the present invention further comprises a curing agent (C) that can react with at least one of a curable resin (A) or a maleimide resin (B), in addition to the resin composition according to any of the first to sixth aspects of the present invention.

[0204] The eighth aspect of the present invention is a resin composition according to any of the first to seventh aspects, further comprising at least one of a styrene-based polymer that is solid at 25°C and an acrylic-based polymer that is solid at 25°C.

[0205] The resin composition according to the ninth aspect of the present invention further contains an inorganic filler in the resin composition of any of the first to eighth aspects.

[0206] The resin composition according to the tenth aspect of the present invention further contains a phosphorus-based flame retardant in the resin composition according to any of the first to ninth aspects.

[0207] A prepreg according to the eleventh aspect of the present invention comprises a resin composition according to any of the first to tenth aspects or a semi-cured product of the resin composition, and a fibrous substrate.

[0208] A resin-coated film according to the twelfth aspect of the present invention comprises a resin layer containing a resin composition according to any of the first to tenth aspects or a semi-cured product of the resin composition, and a support film.

[0209] A resin-coated metal foil according to the thirteenth aspect of the present invention comprises a resin layer containing a resin composition according to any of the first to tenth aspects or a semi-cured product of the resin composition, and a metal foil.

[0210] A metal-clad laminate according to the 14th aspect of the present invention comprises an insulating layer containing a cured product of a resin composition according to any of the 1st to 10th aspects or a cured product of a prepreg according to the 11th aspect, and a metal foil.

[0211] A wiring board according to the 15th aspect of the present invention comprises an insulating layer containing a cured resin composition of any of the 1st to 10th aspects or a cured prepreg of the 11th aspect, and wiring.

[0212] 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.

[0213] First, we will describe each component used in preparing the resin composition in this embodiment.

[0214] (Thermosetting resin (A)) Compound (A-1): A mixture of 1,1,2-(multiple isomers of 2,3- and 4-vinylbenzyl)-1H-indene (83%) and 1,1-(multiple isomers of 2,3- and 4-vinylbenzyl)-1H-indene (17%). Polyphenylene ether compound (A-2): "OPE-2St 2200" (terminated vinylbenzyl-modified PPE) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0215] (Maleimide resin (B)) Maleimide resin (B): "NE-X-9600" manufactured by DIC Corporation (a polymaleimide resin having a substructure represented by formula (1) above, a substructure represented by formula (T-1) above which is chemically bonded to the substructure represented by formula (1) above, and a substructure represented by formula (T-2) above which is chemically bonded to the substructure represented by formula (1) above)

[0216] (Curing agent (C)) Maleimide compound 1: A maleimide compound having an indan structure and an arylene structure bonded to the meta position in its molecule (solid content in "NE-X-9470S" manufactured by DIC Corporation, a maleimide compound represented by formula (8) above)

[0217] (Other resins) - Polyphenylene ether compound: SA9000 (bifunctional methacrylate-modified PPE) manufactured by SABIC Corporation - Bismaleimide compound: BMI-80 manufactured by K.I. Chemicals Co., Ltd.

[0218] (Reaction initiator) • Organic peroxide: PBP (1,3-bis(butylperoxyisopropyl)benzene; "Perbutyl P" manufactured by NOF Corporation)

[0219] (Inorganic filler) ・Silica filler: Methacrylic silane coupling treated silica (Denka Co., Ltd. "GTHM130MC")

[0220] (Flame retardant) ・Flame retardant: Phosphorus-based flame retardant (PQ-60 manufactured by Jin-Yi Chemical Co., Ltd.)

[0221] [Examples 1-3 and Comparative Examples 1-2] (Method for preparing resin varnish) 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 30-650% 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, a varnish-like resin composition (varnish) was obtained.

[0222] Next, the prepreg was obtained as follows.

[0223] The obtained varnish was impregnated into a fibrous substrate (glass cloth: manufactured by Nitto Boseki Co., Ltd., type #1067, NEA glass), and then prepregs were prepared by heating and drying at 110-150°C for 2-5 minutes. At that time, the content of the components constituting the resin in the prepreg (resin content) was adjusted to approximately 74% by mass. Furthermore, the thickness after curing was adjusted to approximately 70 μm.

[0224] An evaluation substrate (metal-clad laminate) was obtained in the following manner.

[0225] Two of the obtained prepregs were stacked together, and 12 μm thick copper foil (3EC-LP III manufactured by Mitsui Mining & Smelting 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 1 to 3 MPa, an evaluation substrate (metal-clad laminate) with a resin layer thickness of approximately 140 μm was obtained, with copper foil bonded to both sides.

[0226] The evaluation substrate prepared as described above was evaluated using the method shown below.

[0227] <Evaluation Tests> In the evaluation tests of dielectric properties (dielectric loss tangent Df) and Tg, an unclad plate (hardened prepreg, approximately 140 μm thick) obtained by etching off the copper foil from a copper-clad laminate made of two layers of prepreg was used as the evaluation sample for the following evaluation tests.

[0228] [Moldability (Minimum Melt Viscosity)] The resin composition was peeled from the prepreg, and the resulting resin composition powder was pressurized to form pellets. These pellets were used as evaluation samples, and the minimum melt viscosity was measured using a rheometer (Rheosol-G3000, manufactured by UBM Co., Ltd.). The passing standard in this test was 600,000 poise or less.

[0229] [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 ≤ 0.0020.

[0230] [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. At this time, dynamic viscoelasticity measurement (DMA) was performed with a tensile module at a frequency of 10 Hz, and the temperature at which tanδ showed a maximum when the temperature was raised from room temperature to 350°C under the condition of a heating rate of 5°C / min was defined as Tg.

[0231] The passing criterion for this examination was set as Tg ≥ 260.

[0232] The results for each of the above evaluations are shown in Table 1.

[0233]

[0234] (Discussion) As can be seen from Table 1, in all of the examples using the resin composition of the present invention, it was confirmed that cured products with excellent moldability, low dielectric properties (dielectric loss tangent), and high Tg can be obtained.

[0235] On the other hand, the resin composition of Comparative Example 1, which did not contain maleimide resin (B), had poor moldability (high minimum melt viscosity) and was inferior to the examples in both low dielectric properties and Tg. Furthermore, Comparative Example 2, which did not contain thermosetting resin (A), had excellent moldability (low minimum melt viscosity), but was inferior to the examples in both low dielectric properties and Tg.

[0236] This application is based on Japanese Patent Application No. 2025-56143, filed on 28 March 2025, the contents of which are included in this application.

[0237] 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.

[0238] 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 curable resin (A) having a group represented by the following formula (a), and a maleimide resin (B), (in formula (a), p represents 0 to 10; Ar represents an arylene group; R α to R γ each independently represent a hydrogen atom or an alkyl group) The resin composition, wherein the maleimide resin (B) is a polymaleimide resin having a partial structure represented by the following formula (1), a partial structure represented by formula (T-1) chemically bonded to the partial structure represented by said formula (1), and a partial structure represented by formula (T-2) chemically bonded to the partial structure represented by said formula (1). (in the above formula (1), R １３ each independently represent an alkyl group having 1 to 18 carbon atoms, m ２ represents an integer of 0 or more and 4 or less, n １ represents an average number of repeating units, two * each represent a bond, one bond is chemically bonded at the position of L １３ or L １４ in the following formula (T-1), and the other bond is chemically bonded at the position of L １１ or L １２ in the following formula (T-2).) (in the above formula (T-1) or (T-2), R １１ and R １５ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R １２ and R １４ each independently represent a hydrocarbon group having 1 to 18 carbon atoms, L １１ to L １４ each independently represent a bond or a hydrogen atom, provided that the position of L １１ or L １２ is chemically bonded to the partial structure represented by formula (1), the position of L １３ or L １４ is chemically bonded to the partial structure represented by formula (1), and any L from L １１ to L １４ that is not chemically bonded to the partial structure represented by formula (1) is a hydrogen atom, m １ and m ３ each represent 2.) 2. The resin composition according to claim 1, wherein the maleimide resin (B) is reacted with an aromatic amine compound represented by the following formula (a-1), a compound having a benzyl ether skeleton, and maleic anhydride as raw materials. (In the above formula (a-1), R ａ１ and R ａ２ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R １ R represents a hydrocarbon group with 1 to 18 carbon atoms. ２ and R ３ Each of these independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.

3. The curable resin (A) is (i) vinylbenzylindene represented by the following formula (I) [In formula (I), R １ , R ２ and R ３ Each of these is independently selected from a vinylbenzyl group, a hydrogen atom, a lower alkyl group, a thioalkoxy group having 1 to 5 carbon atoms, and an aryl group, and R １ , R ２ and R ３ At least one of them is a vinylbenzyl group. ４ (ii) Vinylbenzylfluorene represented by the following formula (II) [In formula (II), each R ５ Each of these is independently selected from a hydrogen atom, a halogen atom, a lower alkyl group, a carbon-1 to carbon-5 alkoxy group, a carbon-1 to carbon-5 thioalkoxy group, and an aryl group. x is an integer from 0 to 4. R ６ and R ７ Each of these is independently selected from a vinylbenzyl group, a hydrogen atom, a lower alkyl group, a thioalkoxy group having 1 to 5 carbon atoms, and an aryl group, and R ６ and R ７ The resin composition according to claim 1, comprising a compound or mixture (A-1) selected from (iii) a vinylbenzyl group, at least one of which is a vinylbenzyl group.

4. The resin composition according to claim 3, wherein the vinylbenzylfluorene is at least one selected from 9,9-bis-(o-vinylbenzyl)-9H-fluorene, 9,9-bis-(m-vinylbenzyl)-9H-fluorene, 9,9-bis-(p-vinylbenzyl)-9H-fluorene, and mixtures thereof.

5. The vinylbenzylindene is 1,1,3-(2-vinylbenzyl)-1H-indene, 1,1,2-(3-vinylbenzyl)-1H-indene, 1,1,2-(4-vinylbenzyl)-1H-indene, 1,1-(2-vinylbenzyl)-1H-indene, 1,1-(3-vinylbenzyl)-1H-indene, 1,1-(4-vinylbenzyl)-1H-indene, 1,3-(2-vinylbenzyl)-1H-indene, 1,3-(3-vinylbenzyl)- The resin composition according to claim 3, comprising at least one selected from 1H-indene; 1,3-(4-vinylbenzyl)-1H-indene, 1-(2-vinylbenzyl)-1H-indene, 1-(3-vinylbenzyl)-1H-indene, 1-(4-vinylbenzyl)-1H-indene, 3-(2-vinylbenzyl)-1H-indene, 3-(3-vinylbenzyl)-1H-indene, 3-(4-vinylbenzyl)-1H-indene, and mixtures thereof.

6. The resin composition according to claim 1, wherein the curable resin (A) comprises a polyphenylene ether compound (A-2) having at least one vinylbenzyl group at its molecular terminus.

7. The resin composition according to claim 1, comprising a curing agent (C) that can react with at least one of a curable resin (A) or a maleimide resin (B).

8. The resin composition according to claim 1, comprising at least one of a styrene-based polymer that is solid at 25°C and an acrylic-based polymer that is solid at 25°C.

9. The resin composition according to claim 1, comprising an inorganic filler.

10. The resin composition according to claim 1, comprising a phosphorus-based flame retardant.

11. A prepreg comprising a resin composition according to any one of claims 1 to 10 or a semi-cured product of the resin composition, and a fibrous substrate.

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

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

14. A metal-clad laminate comprising an insulating layer containing a cured resin composition according to any one of claims 1 to 10, and a metal foil.

15. A metal-clad laminate comprising an insulating layer containing a cured prepreg according to claim 11, and a metal foil.

16. A wiring board comprising an insulating layer containing a cured resin composition according to any one of claims 1 to 10, and wiring.

17. A wiring board comprising an insulating layer containing a cured prepreg according to claim 11, and wiring.

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