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

Abstract

An aspect of the present invention pertains to a resin composition characterized by containing: a polymer having a structural unit represented by formula (1) in a molecule; and a free radical compound, wherein the free radical compound has, in a molecule, at least one free radical group selected from the group of structures represented by formula (2), formula (3), formula (4), and formula (5).

Description

[Technical field]

[0001] The present invention relates to a resin composition, a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board. [Background technology]

[0002] With the increase in the amount of information processed, various electronic devices are undergoing development in packaging technology, such as higher integration of semiconductor devices, higher density wiring, and multi-layering. In addition, wiring boards used in various electronic devices are required to be high-frequency compatible wiring boards, such as millimeter wave radar boards for in-vehicle applications. In order to increase the signal transmission speed, wiring boards used in various electronic devices are required to reduce loss during signal transmission, and this is particularly required for high-frequency compatible wiring boards. In order to meet this requirement, the substrate material for constituting the substrate of the wiring board used in various electronic devices is required to have a low dielectric constant and dielectric loss tangent.

[0003] As such a substrate material, for example, a curable composition containing a soluble polyfunctional vinyl aromatic copolymer and a radical polymerization initiator has been reported (Patent Document 1).

[0004] Patent Document 1 discloses that it is possible to obtain a material that has low dielectric properties and can be applied to cutting-edge electrical and electronic fields that require high-performance electrical, thermal, and mechanical properties. It is believed that a wiring board obtained using a curable composition having low dielectric properties such as a dielectric constant and a dielectric loss tangent as described in Patent Document 1 can reduce loss during signal transmission.

[0005] On the other hand, wiring boards are required to have dielectric properties that do not deteriorate even when used for a long period of time. In order for the dielectric properties of a wiring board to not deteriorate over the long term, it is necessary that the electrical properties (dielectric loss tangent in the examples) of the cured material that constitutes the wiring board do not change.

[0006] A typical method for observing long-term changes in electrical properties is to conduct processing tests in a thermal environment, and it is required that the electrical properties of the cured product change little even in a thermal environment.

[0007] Furthermore, the substrate of the wiring board is required to maintain its low dielectric properties even if it absorbs water, so that the wiring board can be used in a humid environment.

[0008] In other words, in order to enable the wiring board to be used in high temperature or high humidity environments, the substrate material for constituting the wiring board substrate is required to have dielectric properties that are not affected by high temperatures, water absorption, etc.

[0009] In addition, when applied to wiring boards, particularly multi-layer laminated wiring boards, it is necessary to fill the circuit pattern (between the wiring) with a base material (insulating layer molding material), and therefore sufficient resin flowability is required. In this regard, the above-mentioned prior art does not disclose any technology for filling the fine circuit pattern (between the wiring) with a molding material. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] International Publication No. 2017 / 115813 Summary of the Invention

[0011] The present invention has been made in view of the above circumstances, and aims to provide a resin composition capable of producing a cured product that has low dielectric properties, high heat resistance, and is not easily affected by changes in the external environment, and that has moldability that enables application to laminated wiring boards. Another aim 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, which are obtained using the resin composition.

[0012] As a result of extensive investigations, the present inventors have found that the above object can be achieved by the following configuration, and have achieved the present invention through further investigations.

[0013] That is, a resin composition according to one embodiment of the present invention contains a polymer having a structural unit represented by formula (1) in the molecule, which will be described later, and a free radical compound, and the free radical compound has at least one free radical group in the molecule selected from the group of structures represented by formulas (2), (3), (4), and (5), which will be described later. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a prepreg according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an example of a metal-clad laminate according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing an example of a wiring board according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one example of a resin-coated metal foil according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing one example of a resin-coated film according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments of the present invention will be described in detail, but the present invention is not limited to these.

[0016] [Resin composition] A resin composition according to one embodiment of the present invention comprises a polymer having a structural unit represented by the following formula (1) in the molecule, and a free radical compound, wherein the free radical compound has at least one free radical group selected from the group of structures represented by the following formulas (2), (3), (4), and (5) in the molecule.

[0017] [ka]

[0018] [ka]

[0019] [ka]

[0020] [ka]

[0021] [ka]

[0022] In the above formula (1), Z represents an arylene group, R 1 ~R 3 each independently represents a hydrogen atom or an alkyl group; R 4 ~R 6 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0023] According to the above-mentioned constitution, it is possible to obtain a cured product having low dielectric properties and high heat resistance, which can favorably maintain the low dielectric properties even after heat treatment or water absorption treatment, and it is possible to provide a resin composition having excellent moldability that can fill a circuit pattern. Furthermore, according to the present invention, it is possible to provide a prepreg, a resin-attached film, a resin-attached metal foil, a metal-clad laminate, and a wiring board having excellent performance by using the resin composition.

[0024] By adding a free radical compound having the above-described structure to a resin composition containing the polymer, a cured product can be obtained that has low dielectric properties and high heat resistance and can favorably maintain its low dielectric properties even after heat treatment or water absorption treatment, and a resin composition with excellent moldability can be obtained.

[0025] This is believed to be because the addition of a free radical compound can improve moldability while maintaining the cured product properties such as Tg to a certain extent.

[0026] First, each component of the resin composition of the present embodiment will be described.

[0027] (Polymer) The polymer is not particularly limited as long as it has a structural unit represented by the formula (1) in the molecule. In addition, the polymer may have a structural unit other than the structural unit represented by the formula (1) as long as it has a structural unit represented by the formula (1) in the molecule. In addition, the polymer may contain a repeating unit in which the structural unit represented by the formula (1) is repeatedly bonded, or may be a polymer in which a repeating unit in which the structural unit represented by the formula (1) is repeatedly bonded and a repeating unit in which a structural unit other than the structural unit represented by the formula (1) is repeatedly bonded are randomly bonded. That is, when it has a structural unit other than the structural unit represented by the formula (1), it may be a block copolymer or a random copolymer.

[0028] The arylene group represented by Z in the formula (1) is not particularly limited. Examples of the arylene group include monocyclic aromatic groups such as phenylene groups, and polycyclic aromatic groups in which the aromatic ring is not monocyclic but is polycyclic aromatic such as naphthalene rings. The arylene group also includes derivatives in which the hydrogen atom bonded to the aromatic ring is replaced with a functional group such as an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group.

[0029] In the above formula (1), R 1 ~R3 The alkyl group represented by the formula (I) is not particularly limited, and is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0030] In the above formula (1), R 4 ~R 6 The alkyl group having 1 to 6 carbon atoms represented by the following formula (I) is not particularly limited, and specific examples thereof include a methyl group, an ethyl group, a propyl group, and a hexyl group.

[0031] The polymer preferably contains an aromatic polymer having a structural unit derived from a bifunctional aromatic compound having two carbon-carbon unsaturated double bonds bonded to an aromatic ring as the structural unit represented by the formula (1). The structural unit derived from the bifunctional aromatic compound is a structural unit obtained by polymerizing the bifunctional aromatic compound. In this specification, the aromatic polymer is also referred to as a divinyl aromatic polymer.

[0032] The bifunctional aromatic compound is not particularly limited as long as it is a bifunctional aromatic compound having two carbon-carbon unsaturated double bonds bonded to an aromatic ring. Examples of the bifunctional aromatic compound include m-divinylbenzene, p-divinylbenzene, 1,2-diisopropenylbenzene, 1,3-diisopropenylbenzene, 1,4-diisopropenylbenzene, 1,3-divinylnaphthalene, 1,8-divinylnaphthalene, 1,4-divinylnaphthalene, 1,5-divinylnaphthalene, 2,3-divinylnaphthalene, 2,7-divinylnaphthalene, and 2,6-divinylnaphthalene. , 4,4'-divinylbiphenyl, 4,3'-divinylbiphenyl, 4,2'-divinylbiphenyl, 3,2'-divinylbiphenyl, 3,3'-divinylbiphenyl, 2,2'-divinylbiphenyl, 2,4-divinylbiphenyl, 1,2-divinyl-3,4-dimethylbenzene, 1,3-divinyl-4,5,8-tributylnaphthalene, and 2,2'-divinyl-4-ethyl-4'-propylbiphenyl. These may be used alone or in combination of two or more. Among these, the bifunctional aromatic compound is preferably divinylbenzene such as m-divinylbenzene and p-divinylbenzene, and more preferably p-divinylbenzene.

[0033] The aromatic polymer may have not only the structural unit derived from the bifunctional aromatic compound but also other structural units. Examples of the other structural units include a structural unit derived from a monofunctional aromatic compound having one carbon-carbon unsaturated double bond bonded to an aromatic ring, a structural unit derived from a trifunctional aromatic compound having three carbon-carbon unsaturated double bonds bonded to an aromatic ring, a structural unit derived from an indene, and a structural unit derived from an acenaphthylene. The structural unit derived from the monofunctional aromatic compound is a structural unit obtained by polymerizing the monofunctional aromatic compound. The structural unit derived from the trifunctional aromatic compound is a structural unit obtained by polymerizing the trifunctional aromatic compound. The structural unit derived from the indenes is a structural unit obtained by polymerizing indenes. The structural unit derived from the acenaphthylene is a structural unit obtained by polymerizing acenaphthylene.

[0034] The monofunctional aromatic compound may have one carbon-carbon unsaturated double bond bonded to an aromatic ring, and the aromatic ring may have a group other than the carbon-carbon unsaturated double bond bonded.The monofunctional aromatic compound may, for example, be a monofunctional aromatic compound having one carbon-carbon unsaturated double bond bonded to an aromatic ring and no group other than the carbon-carbon unsaturated double bond bonded, or a monofunctional aromatic compound having one carbon-carbon unsaturated double bond bonded to an aromatic ring and further having an alkyl group such as an ethyl group bonded to the aromatic ring.

[0035] Examples of monofunctional aromatic compounds having one carbon-carbon unsaturated double bond bonded to an aromatic ring and no groups other than the carbon-carbon unsaturated double bond bonded include styrene, 2-vinylbiphenyl, 3-vinylbiphenyl, 4-vinylbiphenyl, 1-vinylnaphthalene, 2-vinylnaphthalene, and α-alkyl-substituted styrenes. Examples of α-alkyl-substituted styrenes include α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-n-butylstyrene, α-isobutylstyrene, α-t-butylstyrene, α-n-pentylstyrene, α-2-methylbutylstyrene, α-3-methylbutyl-2-styrene, α-t-butylstyrene, α-t-butylstyrene, α-n-pentylstyrene, α-2-methylbutylstyrene, α-3-methylbutylstyrene, α-t-pentylstyrene, α-n-hexylstyrene, α-ethylstyrene, α-propylstyrene, α-n-butylstyrene, α-iso ...t-pentylstyrene, α-hexylstyrene, α-ethylstyrene, α-propylstyrene, α-n-butylstyrene, α-isobutylstyrene, α-t-butylstyrene, α-n-pentylstyrene, α-t-pentylstyrene, α-hexylstyrene, α-ethylstyrene, α-propylstyrene, α-n-butylstyrene, α-isobutylstyrene, α-t-butylstyrene, α-n-pentylstyrene, α-t-pentylstyrene, α-hexylstyrene, α-ethylstyrene, α-propyl Examples of such styrenes include styrene, α-2-methylpentylstyrene, α-3-methylpentylstyrene, α-1-methylpentylstyrene, α-2,2-dimethylbutylstyrene, α-2,3-dimethylbutylstyrene, α-2,4-dimethylbutylstyrene, α-3,3-dimethylbutylstyrene, α-3,4-dimethylbutylstyrene, α-4,4-dimethylbutylstyrene, α-2-ethylbutylstyrene, α-1-ethylbutylstyrene, α-cyclohexylstyrene, and α-cyclohexylstyrene. These may be used alone or in combination of two or more.

[0036] Examples of monofunctional aromatic compounds having one carbon-carbon unsaturated double bond bonded to an aromatic ring and further having an alkyl group bonded to the aromatic ring include nuclear alkyl-substituted aromatic compounds and alkoxy-substituted styrenes.

[0037] Examples of the nuclear alkyl-substituted aromatic compounds include ethyl vinyl aromatic compounds in which the alkyl group bonded to the aromatic ring is an ethyl group, nuclear alkyl-substituted styrenes in which an alkyl group is bonded to the styrene as the aromatic ring, and nuclear alkyl-substituted aromatic compounds other than the ethyl vinyl aromatic compounds and the nuclear alkyl-substituted styrenes (other nuclear alkyl-substituted aromatic compounds).

[0038] Examples of the ethylvinyl aromatic compounds include o-ethylvinylbenzene, m-ethylvinylbenzene, p-ethylvinylbenzene, 2-vinyl-2'-ethylbiphenyl, 2-vinyl-3'-ethylbiphenyl, 2-vinyl-4'-ethylbiphenyl, 3-vinyl-2'-ethylbiphenyl, 3-vinyl-3'-ethylbiphenyl, 3-vinyl-4'-ethylbiphenyl, 4-vinyl-2'-ethylbiphenyl, 4-vinyl-3'-ethylbiphenyl, 4-vinyl-4'-ethylbiphenyl, 1-vinyl-2-ethyl Examples of the ethylnaphthalene include naphthalene, 1-vinyl-3-ethylnaphthalene, 1-vinyl-4-ethylnaphthalene, 1-vinyl-5-ethylnaphthalene, 1-vinyl-6-ethylnaphthalene, 1-vinyl-7-ethylnaphthalene, 1-vinyl-8-ethylnaphthalene, 2-vinyl-1-ethylnaphthalene, 2-vinyl-3-ethylnaphthalene, 2-vinyl-4-ethylnaphthalene, 2-vinyl-5-ethylnaphthalene, 2-vinyl-6-ethylnaphthalene, 2-vinyl-7-ethylnaphthalene, and 2-vinyl-8-ethylnaphthalene.

[0039] Examples of the nuclear alkyl-substituted styrenes include m-methylstyrene, p-methylstyrene, m-propylstyrene, p-propylstyrene, mn-butylstyrene, pn-butylstyrene, mt-butylstyrene, pt-butylstyrene, mn-hexylstyrene, pn-hexylstyrene, m-cyclohexylstyrene, and p-cyclohexylstyrene.

[0040] Examples of the other nuclear alkyl-substituted aromatic compounds include 2-vinyl-2'-propylbiphenyl, 2-vinyl-3'-propylbiphenyl, 2-vinyl-4'-propylbiphenyl, 3-vinyl-2'-propylbiphenyl, 3-vinyl-3'-propylbiphenyl, 3-vinyl-4'-propylbiphenyl, 4-vinyl-2'-propylbiphenyl, 4-vinyl-3'-propylbiphenyl, 4-vinyl-4'-propylbiphenyl, 1-vinyl-2-propylnaphthalene, 1-vinyl-3-propylnaphthalene, and Examples of propylnaphthalene include 1-vinyl-4-propylnaphthalene, 1-vinyl-5-propylnaphthalene, 1-vinyl-6-propylnaphthalene, 1-vinyl-7-propylnaphthalene, 1-vinyl-8-propylnaphthalene, 2-vinyl-1-propylnaphthalene, 2-vinyl-3-propylnaphthalene, 2-vinyl-4-propylnaphthalene, 2-vinyl-5-propylnaphthalene, 2-vinyl-6-propylnaphthalene, 2-vinyl-7-propylnaphthalene, and 2-vinyl-8-propylnaphthalene.

[0041] Examples of the alkoxy-substituted styrene include o-ethoxystyrene, m-ethoxystyrene, p-ethoxystyrene, o-propoxystyrene, m-propoxystyrene, p-propoxystyrene, on-butoxystyrene, mn-butoxystyrene, pn-butoxystyrene, o-isobutoxystyrene, m-isobutoxystyrene, p-isobutoxystyrene, ot-butoxystyrene, mt-butoxystyrene, pt-butoxystyrene, on-pentoxystyrene, mn-pentoxystyrene, pn-pentoxystyrene, and α-methyl-o-butoxystyrene. , α-methyl-m-butoxystyrene, α-methyl-p-butoxystyrene, ot-pentoxystyrene, mt-pentoxystyrene, pt-pentoxystyrene, on-hexoxystyrene, mn-hexoxystyrene, pn-hexoxystyrene, α-methyl-o-pentoxystyrene, α-methyl-m-pentoxystyrene, α-methyl-p-pentoxystyrene, o-cyclohexoxystyrene, m-cyclohexoxystyrene, p-cyclohexoxystyrene, o-phenoxystyrene, m-phenoxystyrene, and p-phenoxystyrene.

[0042] The monofunctional aromatic compound may be one of the above-listed compounds or a combination of two or more of them. Among the above-listed compounds, styrene and p-ethylvinylbenzene are preferred as the monofunctional aromatic compound.

[0043] Examples of trifunctional aromatic compounds having three carbon-carbon unsaturated double bonds bonded to an aromatic ring include 1,2,4-trivinylbenzene, 1,3,5-trivinylbenzene, 1,2,4-triisopropenylbenzene, 1,3,5-triisopropenylbenzene, 1,3,5-trivinylnaphthalene, and 3,5,4'-trivinylbiphenyl. The trifunctional aromatic compounds may be used alone or in combination of two or more of the above-listed compounds.

[0044] Examples of the indenes include indene, alkyl-substituted indenes, and alkylcyindenes. Examples of the alkyl-substituted indenes include methylindene, ethylindene, propylindene, butylindene, t-butylindene, sec-butylindene, n-pentylindene, 2-methyl-butylindene, 3-methyl-butylindene, n-hexylindene, 2-methyl-pentylindene, 3-methyl-pentylindene, and 4-methyl-pentylindene. Examples of the alkoxyindenes include methoxyindene, ethoxyindene, butoxyindene, butoxyindene, t-butoxyindene, sec-butoxyindene, n-pentoxyindene, 2-methyl-butoxyindene, 3-methyl-butoxyindene, n-hexoxyindene, 2-methyl-pentoxyindene, 3-methyl-pentoxyindene, 4-methyl-pentoxyindene, etc. As the indenes, the above-exemplified compounds may be used alone or in combination of two or more kinds.

[0045] Examples of the acenaphthylenes include acenaphthylene, alkylacenaphthylenes, halogenated acenaphthylenes, and phenylacenaphthylenes. Examples of the alkylacenaphthylenes include 1-methylacenaphthylene, 3-methylacenaphthylene, 4-methylacenaphthylene, 5-methylacenaphthylene, 1-ethylacenaphthylene, 3-ethylacenaphthylene, 4-ethylacenaphthylene, and 5-ethylacenaphthylene. Examples of the halogenated acenaphthylenes include 1-chloroacenaphthylene, 3-chloroacenaphthylene, 4-chloroacenaphthylene, 5-chloroacenaphthylene, 1-bromoacenaphthylene, 3-bromoacenaphthylene, 4-bromoacenaphthylene, and 5-bromoacenaphthylene. Examples of the phenylacenaphthylenes include 1-phenylacenaphthylene, 3-phenylacenaphthylene, 4-phenylacenaphthylene, 5-phenylacenaphthylene, etc. As the acenaphthylenes, the above-exemplified compounds may be used alone or in combination of two or more kinds.

[0046] When the aromatic polymer has not only the structural unit derived from the bifunctional aromatic compound but also other structural units, it is a copolymer of the structural unit derived from the bifunctional aromatic compound and other structural units such as the structural unit derived from the monofunctional aromatic compound, etc. This copolymer may be a block copolymer or a random copolymer.

[0047] As described above, the polymer is not particularly limited as long as it is a polymer having a structural unit represented by the formula (1) in the molecule. The structural unit represented by the formula (1) preferably includes a structural unit represented by the following formula (9). That is, the polymer is preferably a polymer having a structural unit represented by the following formula (2) in the molecule.

[0048] [ka]

[0049] In formula (9), R 4 ~R 6 is R in formula (1). 4 ~R 6 Specifically, R 4 ~R 6 R each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 7 represents an arylene group having 6 to 12 carbon atoms.

[0050] The arylene group having 6 to 12 carbon atoms in the formula (9) is not particularly limited. Examples of the arylene group include monocyclic aromatic groups such as phenylene groups, and bicyclic aromatic groups in which the aromatic ring is not monocyclic but is bicyclic aromatic such as naphthalene rings. The arylene group also includes derivatives in which a hydrogen atom bonded to the aromatic ring is substituted with a functional group such as an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group.

[0051] The structural unit represented by the formula (9) preferably contains a structural unit represented by the following formula (10). That is, in the structural unit represented by the formula (9), R 7 is preferably a phenylene group. Among the phenylene groups, a p-phenylene group is more preferable.

[0052] [ka]

[0053] In formula (10), R 4 ~R 6 is R in formula (1). 4 ~R 6 Specifically, R 4 ~R 6 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0054] The polymer preferably includes a polymer further having a structural unit represented by the following formula (11) in the molecule. That is, the polymer preferably includes, as the structural unit represented by the following formula (11), a structural unit derived from a monofunctional aromatic compound having one carbon-carbon unsaturated double bond bonded to an aromatic ring. Therefore, the polymer is preferably a polymer having, in the molecule, a structural unit represented by the formula (1) and a structural unit represented by the following formula (11). That is, the polymer may have a structural unit other than the structural unit represented by the formula (1) and the structural unit represented by the following formula (11) (structural units other than (1) and (11)) as long as the polymer has, in the molecule, a structural unit represented by the formula (1) and a structural unit represented by the following formula (11). The polymer may contain structural units other than the structural units (1) and (11), or may be a polymer, a block copolymer, or a random copolymer in which a repeating unit in which the structural unit represented by the formula (1) is repeatedly bonded, a repeating unit represented by the following formula (11), and a repeating unit in which the structural unit other than the structural units (1) and (11) are repeatedly bonded are randomly bonded.

[0055] [ka]

[0056] In formula (11), R 8 ~R 10 are independent of each other. That is, R 8 ~R 10 may be the same or different groups. 8 ~R 10 R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 11 represents an aryl group.

[0057] In the formula (11), R 8 ~R 10 The alkyl group having 1 to 6 carbon atoms represented by the formula (1) is not particularly limited, and 4 ~R 6 In the formula (11), R 8 ~R 10 Specific examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, and a hexyl group.

[0058] In the formula (11), R 11The aryl group represented by is not particularly limited, and may be an unsubstituted aryl group, or an aryl group in which a hydrogen atom bonded to an aromatic ring is substituted with an alkyl group or the like. The unsubstituted aryl group may be a group in which one hydrogen atom is removed from an aromatic hydrocarbon having one aromatic ring, or a group in which one hydrogen atom is removed from an aromatic hydrocarbon having two or more independent aromatic rings (e.g., biphenyl, etc.). Examples of the aryl group in the formula (11) include an unsubstituted aryl group having 6 to 12 carbon atoms, and an arylene group having 6 to 18 carbon atoms in which a hydrogen atom of an aryl group having 6 to 12 carbon atoms is substituted with an alkyl group having 1 to 6 carbon atoms. Examples of the unsubstituted aryl group having 6 to 12 carbon atoms include a phenyl group, a naphthyl group, and a biphenylyl group. The aryl group in the formula (11), that is, R 11 More specifically, the aryl groups include those shown in Tables 1 and 2 below.

[0059] [Table 1]

[0060] [Table 2]

[0061] The weight average molecular weight of the polymer is preferably 1500 to 40000, more preferably 1500 to 35000. If the weight average molecular weight is too low, the heat resistance and the like tend to decrease. If the weight average molecular weight is too high, the moldability and the like tend to decrease. Therefore, if the weight average molecular weight of the resin composition is within the above range, the heat resistance and moldability are excellent. Here, the weight average molecular weight may be measured by a general molecular weight measurement method, and specifically, a value measured using gel permeation chromatography (GPC) and the like can be mentioned.

[0062] In the polymer, when the total of the structural units in the polymer is 100 mol%, the molar content of the structural unit represented by the formula (1) is preferably within the range of the above weight average molecular weight, specifically, preferably 2 to 95 mol%, more preferably 8 to 81 mol%. The molar content of the structural unit represented by the formula (9) and the molar content of the structural unit represented by the formula (10) are the same as the molar content of the structural unit represented by the formula (1), specifically, preferably 2 to 95 mol%, more preferably 8 to 81 mol%. In the case where the polymer has the structural unit represented by the formula (1) and the structural unit represented by the following formula (11) in the molecule, the molar content of the structural unit represented by the formula (1) is preferably 2 to 95 mol%, more preferably 8 to 81 mol%, and the molar content of the structural unit represented by the formula (11) is preferably 5 to 98 mol%, more preferably 19 to 92 mol%.

[0063] In the polymer, the average number of the structural units represented by the formula (1) is preferably a number within the range of the weight average molecular weight, specifically, preferably 1 to 160, more preferably 3 to 140. The average number of the structural units represented by the formula (9) and the average number of the structural units represented by the formula (10) are the same as the average number of the structural units represented by the formula (1), specifically, preferably 1 to 160, more preferably 3 to 140. In addition, when the polymer has a structural unit represented by the formula (1) and a structural unit represented by the following formula (11) in the molecule, the average number of the structural units represented by the formula (1) is preferably 1 to 160, more preferably 3 to 140, and the average number of the structural units represented by the formula (11) is preferably 2 to 350, more preferably 4 to 300.

[0064] Specific examples of the polymer include a polymer containing a structural unit represented by the following formula (12) in the molecule and further containing at least one of a structural unit represented by the following formula (13) and a structural unit represented by the following formula (14). This polymer may be a block copolymer or a random copolymer.

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] In the polymer containing the structural unit represented by the formula (13) in the molecule and further containing at least one of the structural unit represented by the formula (12) and the structural unit represented by the formula (14), the molar contents of the structural unit represented by the formula (12), the structural unit represented by the formula (13), and the structural unit represented by the formula (14) are preferably 0 to 92 mol%, 8 to 54 mol%, and 0 to 89 mol%, respectively. The average number of the structural units represented by the formula (12) is preferably 0 to 350, the average number of the structural units represented by the formula (13) is preferably 1 to 160, and the average number of the structural units represented by the formula (14) is preferably 0 to 270.

[0069] The polymer is represented by the formula (1), 1 ~R 3The equivalent of the vinyl group contained in the structural unit in which R is a hydrogen atom is preferably 250 to 1200, more preferably 300 to 1100. If the equivalent is too small, the vinyl group becomes too many, and the reactivity becomes too high, which may cause problems such as a decrease in the storage stability of the resin composition or a decrease in the flowability of the resin composition. If a resin composition having a too small equivalent is used, there may be a moldability problem such that molding defects such as the generation of voids during multilayer molding occur due to insufficient flowability, making it difficult to obtain a highly reliable wiring board. In addition, if the equivalent is too large, the vinyl group becomes too few, and the heat resistance of the cured product tends to be insufficient. Therefore, when the equivalent is within the above range, the heat resistance and moldability are excellent. In addition, when the vinyl group is represented by the formula (1) and R 1 ~R 3 The equivalent of the vinyl group contained in the structural unit in which is a hydrogen atom is the so-called vinyl equivalent.

[0070] (Free radical compounds) The free radical compound used in this embodiment is not particularly limited as long as it is a free radical compound having at least one of the structures represented by the above formulas (2) to (5). By including such a free radical compound, it is considered that the resin composition of this embodiment can exhibit excellent moldability (moldability capable of filling a circuit pattern) while having properties such as low dielectric properties and heat resistance. Furthermore, it is considered that a cured product capable of favorably maintaining low dielectric properties can be obtained even after heat treatment or water absorption treatment.

[0071] Preferably, the free radical compound of the present embodiment includes at least one compound selected from the compounds represented by the following formulas (6) to (8).

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] In the formula (6) and the formula (7), X A and X B each independently represents a hydrogen atom, an amino group, a cyano group, a hydroxy group, an isothiocyanate group, a methoxy group, a carboxy group, a carbonyl group, an amido group, a benzoyloxy group, or an ether bond.

[0076] More specific examples of these include 4-acetamido, 4-glycidyloxy, 4-benzoyloxy, 4-(2-iodoacetamido), 4-[2-[2-(4-iodophenoxy)ethoxy]carbonyl]benzoyloxy, 4-methacryloyloxy, 4-oxo, and 4-propargyloxy.

[0077] In addition, in the formula (8), X C represents an alkylene group, an aromatic structure, a carbonyl group, an amide group or an ether bond.

[0078] The alkylene group may have a straight chain structure, a side chain structure and / or a cyclic structure, and the length of the straight chain and the side chain is not particularly limited. If the number of carbon atoms is too large, the solubility of the resin component in the solvent may decrease, so for example, the number of carbon atoms is preferably 16 or less, and particularly preferably about 8 or less.

[0079] When the alkylene group has a cyclic structure, examples of the cyclic structure include a seven-membered ring, a six-membered ring, and a five-membered ring.

[0080] Examples of the aromatic structure include a phenyl group, a pyrrole group, and a thiazole group.

[0081] More specific examples of the free radical compound preferably used in this embodiment include 4-amino-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-amino-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-carboxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-cyano-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-glycidyloxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl benzoate free radical, and 4-isothiocyanato-2,2,6,6-tetramethylpiperidine 1-oxyl. Free radical, 4-(2-iodoacetamido)-2,2,6,6-tetramethylpiperidine 1-oxyl Free radical, 4-[2-[2-(4-iodophenoxy)ethoxy]carbonyl]benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidine 1-oxyl Free radical, 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine 1-oxyl Free radical, 4-oxo-2,2,6,6-tetramethylpiperidine 1-oxyl Free radical, 4-oxo-2,2,6,6-tetramethylpiperidine 1-oxyl Free radical, 2,2,6,6-tetramethylpiperidine 1-oxyl Free radical, 2,2,6,6-tetramethylpiperidine 1-oxyl Free radical, 2,2,6,6-tetramethylpiperidine 1-oxyl Free radical, 4,5-dihydro-4,4,5,5-tetramethyl-2-phenyl-1H-imidazol-1-yloxy-1-oxide, bis(2,2,6,6-tetramethyl-4-piperidyl-1-oxyl) sebacate, 3-carboxy-2,2,5,5-tetramethylpyrrolidine 1-oxyl Free radical, 4-(2-chloroacetamido)-2,2,6,Examples of such radicals include 6-tetramethylpiperidine 1-oxyl free radical, 2-(4-nitrophenyl)-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl free radical, 2-(14-carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolidinyloxy free radical, and 1,1-diphenyl-2-picrylhydrazyl free radical.

[0082] Various free radical compounds have been mentioned above, and these may be used alone or in combination of two or more.

[0083] The free radical compound of the present embodiment as described above may be a commercially available product, and is available, for example, from Tokyo Chemical Industry Co., Ltd.

[0084] (hardening agent) The curing agent is not particularly limited as long as it can react with the polymer to cure the resin composition containing the polymer. The curing agent includes a curing agent having at least one functional group in the molecule that contributes to the reaction with the polymer. Examples of the curing agent include styrene, 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.

[0085] Examples of the styrene derivatives include bromostyrene and dibromostyrene.

[0086] The compound having an acryloyl group in the molecule is an acrylate compound. The acrylate compound includes a monofunctional acrylate compound having one acryloyl group in the molecule, and a polyfunctional acrylate compound having two or more acryloyl groups in the molecule. The monofunctional acrylate compound includes, for example, methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. The polyfunctional acrylate compound includes, for example, tricyclodecane dimethanol diacrylate.

[0087] The compound having a methacryloyl group in the molecule is a methacrylate compound. The methacrylate compound may be a monofunctional methacrylate compound having one methacryloyl group in the molecule, or a polyfunctional methacrylate compound having two or more methacryloyl groups in the molecule. The monofunctional methacrylate compound may be, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. The polyfunctional methacrylate compound may be, for example, tricyclodecane dimethanol dimethacrylate.

[0088] The compound having a vinyl group in the molecule is a vinyl compound. The vinyl compound includes a monofunctional vinyl compound (monovinyl compound) having one vinyl group in the molecule, and a polyfunctional vinyl compound having two or more vinyl groups in the molecule. The polyfunctional vinyl compound includes, for example, divinylbenzene and polybutadiene.

[0089] The compound having an allyl group in the molecule is an allyl compound. The allyl compound includes a monofunctional allyl compound having one allyl group in the molecule, and a polyfunctional allyl compound having two or more allyl groups in the molecule. The polyfunctional allyl compound includes, for example, diallyl phthalate (DAP).

[0090] The compound having a maleimide group in the molecule is a maleimide compound. Examples of the maleimide compound include a monofunctional maleimide compound having one maleimide group in the molecule, a polyfunctional maleimide compound having two or more maleimide groups in the molecule, and a modified maleimide compound. Examples of the modified maleimide compound include a modified maleimide compound in which a part of the molecule is modified with an amine compound, a modified maleimide compound in which a part of the molecule is modified with a silicone compound, and a modified maleimide compound in which a part of the molecule is modified with an amine compound and a silicone compound.

[0091] The compound having an acenaphthylene structure in the molecule is an acenaphthylene compound. Examples of the acenaphthylene compound include acenaphthylene, alkylacenaphthylenes, halogenated acenaphthylenes, and phenylacenaphthylenes. Examples of the alkylacenaphthylenes include 1-methylacenaphthylene, 3-methylacenaphthylene, 4-methylacenaphthylene, 5-methylacenaphthylene, 1-ethylacenaphthylene, 3-ethylacenaphthylene, 4-ethylacenaphthylene, and 5-ethylacenaphthylene. Examples of the halogenated acenaphthylenes include 1-chloroacenaphthylene, 3-chloroacenaphthylene, 4-chloroacenaphthylene, 5-chloroacenaphthylene, 1-bromoacenaphthylene, 3-bromoacenaphthylene, 4-bromoacenaphthylene, and 5-bromoacenaphthylene. Examples of the phenylacenaphthylenes include 1-phenylacenaphthylene, 3-phenylacenaphthylene, 4-phenylacenaphthylene, and 5-phenylacenaphthylene. The acenaphthylene compound may be a monofunctional acenaphthylene compound having one acenaphthylene structure in the molecule as described above, or a polyfunctional acenaphthylene compound having two or more acenaphthylene structures in the molecule.

[0092] Among the above, preferred curing agents are, for example, polyfunctional acrylate compounds having two or more acryloyl groups in the molecule, polyfunctional methacrylate compounds having two or more methacryloyl groups in the molecule, polyfunctional vinyl compounds having two or more vinyl groups in the molecule, styrene derivatives, allyl compounds having an allyl group in the molecule, maleimide compounds having a maleimide group in the molecule, and acenaphthylene compounds having an acenaphthylene structure in the molecule.

[0093] The curing agent may be used alone or in combination of two or more kinds.

[0094] The curing agent preferably has a weight average molecular weight of 100 to 5000, more preferably 100 to 4000, and even more preferably 100 to 3000. If the weight average molecular weight of the curing agent is too low, the curing agent may be easily volatilized from the compounding components of the resin composition. If the weight average molecular weight of the curing agent is too high, the viscosity of the varnish of the resin composition and the melt viscosity during heat molding may be too high. Therefore, if the weight average molecular weight of the curing agent is within such a range, a resin composition having excellent heat resistance of the cured product can be obtained. This is considered to be because the resin composition containing the polymer can be suitably cured by the reaction with the polymer. Here, the weight average molecular weight may be measured by a general molecular weight measurement method, and specifically, a value measured using gel permeation chromatography (GPC) may be mentioned.

[0095] The average number of functional groups per molecule of the curing agent that contribute to the reaction with the polymer (number of functional groups) varies depending on the weight average molecular weight of the curing agent, but is preferably 1 to 20, more preferably 2 to 18. If the number of functional groups is too small, it tends to be difficult to obtain a cured product with sufficient heat resistance. If the number of functional groups is too large, the reactivity becomes too high, and there is a risk of problems such as a decrease in the storage stability of the resin composition or a decrease in the flowability of the resin composition.

[0096] (Reaction initiator) The resin composition according to the present embodiment may further contain a reaction initiator (initiator). The resin composition may proceed with a curing reaction even if it is composed of the modified polyphenylene ether compound and the curing agent. The curing reaction may proceed even if only the modified polyphenylene ether compound is present. However, depending on the process conditions, it may be difficult to raise the temperature to a level where curing proceeds, so a reaction initiator may be added.

[0097] The reaction initiator is not particularly limited as long as it can accelerate the curing reaction of the modified polyphenylene ether compound (and the curing agent, if included).Specific examples of the reaction initiator include metal oxides, azo compounds, and organic peroxides.

[0098] Specific examples of metal oxides include metal carboxylates.

[0099] Examples of organic peroxides include α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, benzoyl peroxide, 3,3',5,5'-tetramethyl-1,4-diphenoquinone, chloranil, 2,4,6-tri-t-butylphenoxyl, t-butylperoxyisopropyl monocarbonate, and azobisisobutyronitrile.

[0100] Specific examples of the azo compound include 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(2-methylbutyronitrile).

[0101] Among them, preferred reaction initiators are 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), etc. These reaction initiators have little effect on dielectric properties. In addition, since the reaction initiation temperature is relatively high, it is possible to suppress the promotion of the curing reaction at the time when curing is not required, such as during drying of the prepreg, and thus has the advantage of suppressing the deterioration of the storage stability of the resin composition.

[0102] The above-mentioned reaction initiators may be used alone or in combination of two or more kinds.

[0103] (Inorganic filler) The resin composition according to the present embodiment may further contain a filler such as an inorganic filler. Examples of the filler include those added to suppress the thermal expansion of the cured product of the resin composition and to increase the flame retardancy, and are not particularly limited. In addition, by including a filler, the heat resistance and flame retardancy can be further increased. Specific examples of the filler include silica such as spherical 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 preferable as the filler, and spherical silica is more preferable. In addition, the filler may be used alone or in combination of two or more types. In addition, the filler may be used as it is, or may be surface-treated with the silane coupling agent.

[0104] It is also preferable to use silica as the inorganic filler, in which the ratio of the number of Si atoms contained in silanol groups to the number of all Si atoms is 3% or less. It is considered that the resin composition of the present embodiment contains silica having a small number of silanol groups as an inorganic filler, and the resin composition can be obtained with a cured product that can more suitably maintain low dielectric properties even after heat treatment. The silica has a ratio of the number of Si atoms contained in silanol groups to the number of all Si atoms of 3% or less, preferably 2.5% or less, and more preferably 2% or less. The lower this ratio is, the better, but in reality, the limit is about 0.1%. For this reason, the ratio is preferably 0.1 to 3%.

[0105] The measurement of the ratio of the number of Si atoms contained in silanol groups to the total number of Si atoms in silica is not particularly limited as long as the ratio of the number of Si atoms contained in silanol groups (Si-OH) contained in silica to the total number of Si atoms contained in silica can be measured. For example, 29 This can be measured by obtaining a silica spectrum using Si-NMR measurement.

[0106] (Modified polyphenylene ether compound) The resin composition preferably further contains a modified polyphenylene ether compound whose terminal is modified with a substituent having a carbon-carbon unsaturated double bond. The modified polyphenylene ether compound is not particularly limited as long as it is a modified polyphenylene ether compound whose terminal is modified with a substituent having a carbon-carbon unsaturated double bond.

[0107] The substituent having a carbon-carbon unsaturated double bond is not particularly limited. Examples of the substituent include a substituent represented by the following formula (15) and a substituent represented by the following formula (16).

[0108] [ka]

[0109] In formula (15), p represents an integer of 0 to 10. A represents an arylene group. 12 ~R 14 are independent of each other. That is, R 12 ~R 14 may be the same or different groups. 12 ~R 14 represents a hydrogen atom or an alkyl group.

[0110] In addition, in formula (15), when p is 0, Z A is directly bonded to the end of the polyphenylene ether.

[0111] The arylene group is not particularly limited. Examples of the arylene group include monocyclic aromatic groups such as phenylene groups, and polycyclic aromatic groups in which the aromatic ring is not monocyclic but is polycyclic aromatic such as naphthalene ring. The arylene group also includes derivatives in which a hydrogen atom bonded to the aromatic ring is substituted with a functional group such as an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. The alkyl group is not particularly limited, and is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0112] [ka]

[0113] In formula (16), R 15 represents a hydrogen atom or an alkyl group. The alkyl group is not particularly limited, and is preferably, for example, an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0114] A preferred specific example of the substituent represented by the formula (15) is a substituent containing a vinylbenzyl group. An example of the substituent containing a vinylbenzyl group is a substituent represented by the following formula (17). An example of the substituent represented by the formula (16) is an acrylate group or a methacrylate group.

[0115] [ka]

[0116] More specifically, examples of the substituent include vinylbenzyl groups (ethenylbenzyl groups) such as p-ethenylbenzyl group and m-ethenylbenzyl group, vinylphenyl groups, acrylate groups, and methacrylate groups.

[0117] The modified polyphenylene ether compound has a polyphenylene ether chain in the molecule, and preferably has, for example, a repeating unit represented by the following formula (18) in the molecule.

[0118] [ka]

[0119] In formula (18), t is an integer of 1 to 50. 16 ~R 19 are independent of each other. That is, R 16 ~R 19 may be the same or different groups. 16 ~R 19 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 which a hydrogen atom and an alkyl group are preferred.

[0120] R 16 ~R 19Specific examples of the functional groups mentioned in the above include the following:

[0121] The alkyl group is not particularly limited, but is preferably, for example, an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0122] The alkenyl group is not particularly limited, but is preferably an alkenyl group having 2 to 18 carbon atoms, and more preferably an alkenyl group having 2 to 10 carbon atoms. Specific examples include a vinyl group, an allyl group, and a 3-butenyl group.

[0123] The alkynyl group is not particularly limited, but for example, an alkynyl group having 2 to 18 carbon atoms is preferable, and an alkynyl group having 2 to 10 carbon atoms is more preferable. Specific examples include an ethynyl group, a prop-2-yn-1-yl group (propargyl group), and the like.

[0124] The alkylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkyl group, and is preferably, for example, an alkylcarbonyl group having 2 to 18 carbon atoms, and more preferably an alkylcarbonyl group having 2 to 10 carbon atoms. Specific examples include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a hexanoyl group, an octanoyl group, and a cyclohexylcarbonyl group.

[0125] The alkenylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkenyl group, but for example, an alkenylcarbonyl group having 3 to 18 carbon atoms is preferable, and an alkenylcarbonyl group having 3 to 10 carbon atoms is more preferable. Specific examples include an acryloyl group, a methacryloyl group, and a crotonoyl group.

[0126] The alkynylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkynyl group, but for example, an alkynylcarbonyl group having 3 to 18 carbon atoms is preferable, and an alkynylcarbonyl group having 3 to 10 carbon atoms is more preferable. Specific examples include a propioloyl group.

[0127] The weight average molecular weight (Mw) of the modified polyphenylene ether compound is not particularly limited. Specifically, it is preferably 500 to 5000, more preferably 800 to 4000, and further preferably 1000 to 3000. The weight average molecular weight may be measured by a general molecular weight measurement method, and specifically, it may be a value measured using gel permeation chromatography (GPC). In addition, when the modified polyphenylene ether compound has a repeating unit represented by the formula (18) in the molecule, t is preferably a numerical value that causes the weight average molecular weight of the modified polyphenylene ether compound to be within such a range. Specifically, t is preferably 1 to 50.

[0128] When the weight average molecular weight of the modified polyphenylene ether compound is within such a range, the compound has excellent low dielectric properties that polyphenylene ether has, and the cured product has excellent heat resistance and excellent moldability. This is believed to be due to the following. When the weight average molecular weight of a normal polyphenylene ether is within such a range, the cured product has a relatively low molecular weight, so the heat resistance tends to decrease. In this respect, since the modified polyphenylene ether compound according to the present embodiment has an unsaturated double bond at the end, it is believed that the cured product has sufficiently high heat resistance. In addition, when the weight average molecular weight of the modified polyphenylene ether compound is within such a range, the compound has a relatively low molecular weight, so it is believed that the cured product has excellent moldability. Therefore, it is believed that such a modified polyphenylene ether compound not only has excellent heat resistance, but also has excellent moldability.

[0129] The average number of the substituents (number of terminal functional groups) at the molecular end per molecule of the modified polyphenylene ether compound is not particularly limited. Specifically, it is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1.5 to 3. If the number of terminal functional groups is too small, it is difficult to obtain a cured product with sufficient heat resistance. If the number of terminal functional groups is too large, the reactivity becomes too high, and there is a possibility that problems such as, for example, deterioration in the storage stability of the resin composition or deterioration in the fluidity of the resin composition may occur. That is, when such a modified polyphenylene ether compound is used, there is a possibility that a molding defect such as the generation of voids during multilayer molding may occur due to insufficient fluidity, and a moldability problem may occur such that it is difficult to obtain a highly reliable printed wiring board.

[0130] The number of terminal functional groups of the modified polyphenylene ether compound may be a numerical value representing the average value of the above-mentioned substituents per molecule of all modified polyphenylene ether compounds present in 1 mole of the modified polyphenylene ether compound. The 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 and calculating the reduction from the number of hydroxyl groups of the polyphenylene ether before modification. The reduction from the number of hydroxyl groups of 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.

[0131] The intrinsic viscosity of the modified polyphenylene ether compound is not particularly limited. Specifically, it may be 0.03 to 0.12 dl / g, preferably 0.04 to 0.11 dl / g, and more preferably 0.06 to 0.095 dl / g. If the intrinsic viscosity is too low, the molecular weight tends to be low, and low dielectric properties such as low dielectric constant and low dielectric loss tangent tend to be difficult to obtain. If the intrinsic viscosity is too high, the viscosity is high, sufficient fluidity cannot be obtained, and the moldability of the cured product tends to decrease. Therefore, if the intrinsic viscosity of the modified polyphenylene ether compound is within the above range, excellent heat resistance and moldability of the cured product can be realized.

[0132] The intrinsic viscosity here is the intrinsic viscosity measured in methylene chloride at 25° C., and more specifically, for example, the value measured by a viscometer using a 0.18 g / 45 ml methylene chloride solution (liquid temperature 25° C.) As the viscometer, for example, the AVS500 Visco System manufactured by Schott Corporation can be mentioned.

[0133] Examples of the modified polyphenylene ether compound include a modified polyphenylene ether compound represented by the following formula (19) and a modified polyphenylene ether compound represented by the following formula (20). As the modified polyphenylene ether compound, these modified polyphenylene ether compounds may be used alone or in combination of these two modified polyphenylene ether compounds.

[0134] [ka]

[0135] [ka]

[0136] In formula (19) and formula (20), R 20 ~R 27 And R 28 ~R 35each 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. X 1 and X 2 each independently represents a substituent having a carbon-carbon unsaturated double bond. A and B represent repeating units represented by the following formula (21) and formula (22), respectively. In addition, in formula (20), Y represents a linear, branched, or cyclic hydrocarbon having 20 or less carbon atoms.

[0137] [ka]

[0138] [ka]

[0139] In the formulas (21) and (22), m and n each represent an integer of 0 to 20. 36 ~R 39 And R 40 ~R 43 each 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.

[0140] The modified polyphenylene ether compound represented by the formula (19) and the modified polyphenylene ether compound represented by the formula (20) are not particularly limited as long as they satisfy the above-mentioned constitution. 20 ~R 27 And R 28 ~R 35 are independent of each other as described above. That is, R 20 ~R 27 And R 28 ~R 35 may be the same or different groups. 20 ~R 27 And R28 ~R 35 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 which a hydrogen atom and an alkyl group are preferred.

[0141] In the formula (21) and the formula (22), m and n each preferably represent 0 to 20 as described above. In addition, it is preferable that m and n represent a numerical value such that the sum of m and n is 1 to 30. Therefore, it is more preferable that m represents 0 to 20, n represents 0 to 20, and the sum of m and n represents 1 to 30. In addition, R 36 ~R 39 And R 40 ~R 43 are independent of each other. That is, R 36 ~R 39 And R 40 ~R 43 may be the same or different groups. 36 ~R 39 And R 40 ~R 43 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 which a hydrogen atom and an alkyl group are preferred.

[0142] R 20 ~R 43 is R in the above formula (18). 16 ~R 19 is the same as:

[0143] In the formula (20), as described above, Y is a linear, branched, or cyclic hydrocarbon having a carbon number of 20 or less. Examples of Y include a group represented by the following formula (23).

[0144] [ka]

[0145] In the formula (23), R 44 and R 45 are each independently a hydrogen atom or an alkyl group. Examples of the alkyl group include a methyl group. Examples of the group represented by formula (23) include a methylene group, a methylmethylene group, and a dimethylmethylene group, and among these, a dimethylmethylene group is preferred.

[0146] In the formula (19) and the formula (20), X 1 and X 2 Each of the substituents X is independently a substituent having a carbon-carbon unsaturated double bond. 1 and X 2 There is no particular limitation on the substituent X, so long as it is a substituent having a carbon-carbon unsaturated double bond. 1 and X 2 Examples of the substituent include the substituent represented by the above formula (16) and the substituent represented by the above formula (17). In the modified polyphenylene ether compound represented by the above formula (19) and the modified polyphenylene ether compound represented by the above formula (20), X 1 and X 2 may be the same or different substituents.

[0147] A more specific example of the modified polyphenylene ether compound represented by the formula (19) includes a modified polyphenylene ether compound represented by the following formula (24).

[0148] [ka]

[0149] More specific examples of the modified polyphenylene ether compound represented by the formula (20) include a modified polyphenylene ether compound represented by the following formula (25) and a modified polyphenylene ether compound represented by the following formula (26).

[0150] [ka]

[0151] [ka]

[0152] In the above formulas (24) to (26), m and n have the same meaning as m and n in the above formulas (21) and (22), and are independently 0 to 20. In addition, in the above formulas (24) and (25), R 12 ~R 14 , p and Z A is R in the above formula (15). 12 ~R 14 , p and Z A In the above formula (25) and formula (26), Y is the same as Y in the above formula (20). In the above formula (26), R 15 is R in the above formula (16). 15 is the same as:

[0153] The method for synthesizing the modified polyphenylene ether compound used in the present embodiment is not particularly limited as long as it is possible to synthesize a modified polyphenylene ether compound whose terminal is modified by a substituent having a carbon-carbon unsaturated double bond.Specific examples include a method of reacting a polyphenylene ether with a compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded.

[0154] Examples of the compound in which a substituent having a carbon-carbon unsaturated double bond is bonded to a halogen atom include compounds in which a substituent having the above formulas (15) to (17) is bonded to a halogen atom. Specific examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom, and among these, a chlorine atom is preferred. More specific examples of the compound in which a substituent having a carbon-carbon unsaturated double bond is bonded to a halogen atom include p-chloromethylstyrene and m-chloromethylstyrene.

[0155] The raw material polyphenylene ether is not particularly limited as long as it can finally synthesize a predetermined modified polyphenylene ether compound. Specifically, polyphenylene ethers composed of 2,6-dimethylphenol and at least one of a bifunctional phenol and a trifunctional phenol, and poly(2,6-dimethyl-1,4-phenylene oxide) and the like, which are mainly composed of polyphenylene ether, can be mentioned. In addition, the bifunctional phenol is a phenolic compound having two phenolic hydroxyl groups in the molecule, for example, tetramethylbisphenol A, etc. In addition, the trifunctional phenol is a phenolic compound having three phenolic hydroxyl groups in the molecule.

[0156] The synthesis method of the modified polyphenylene ether compound includes the above-mentioned method. Specifically, the above-mentioned polyphenylene ether and a compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded are dissolved in a solvent and stirred. By doing so, the polyphenylene ether reacts with the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, and the modified polyphenylene ether compound used in the present embodiment is obtained.

[0157] The reaction is preferably carried out in the presence of an alkali metal hydroxide. By doing so, it is believed that the reaction proceeds favorably. This is believed to be because the alkali metal hydroxide functions as a dehydrohalogenation agent, specifically, a dehydrochlorination agent. That is, it is believed that the alkali metal hydroxide removes hydrogen halide from the phenol group of the polyphenylene ether and the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, and thereby the substituent having a carbon-carbon unsaturated double bond is bonded to the oxygen atom of the phenol group instead of the hydrogen atom of the phenol group of the polyphenylene ether.

[0158] The alkali metal hydroxide is not particularly limited as long as it can act as a dehalogenating agent, and examples thereof include sodium hydroxide, etc. The alkali metal hydroxide is usually used in the form of an aqueous solution, specifically, an aqueous sodium hydroxide solution.

[0159] The reaction conditions such as reaction time and reaction temperature vary depending on the compound in which a substituent having a carbon-carbon unsaturated double bond is bonded to a halogen atom, and are not particularly limited as long as the reaction proceeds favorably under the conditions. Specifically, the reaction temperature is preferably room temperature to 100°C, more preferably 30 to 100°C. The reaction time is preferably 0.5 to 20 hours, more preferably 0.5 to 10 hours.

[0160] The solvent used in the reaction is not particularly limited as long as it can dissolve the polyphenylene ether and the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, and does not inhibit the reaction between the polyphenylene ether and the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded.Specific examples include toluene and the like.

[0161] The above reaction is preferably carried out in the presence of not only an alkali metal hydroxide but also a phase transfer catalyst. That is, the above reaction is preferably carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst. It is believed that the above reaction proceeds more favorably by doing so. This is believed to be due to the following. It is believed that the phase transfer catalyst is a catalyst that has the function of incorporating an alkali metal hydroxide, is soluble in both a polar solvent phase such as water and a non-polar solvent phase such as an organic solvent, and can move between these phases. Specifically, when an aqueous sodium hydroxide solution is used as the alkali metal hydroxide and an organic solvent such as toluene, which is not compatible with water, is used as the solvent, even if the aqueous sodium hydroxide solution is dropped into the solvent being used for the reaction, the solvent and the aqueous sodium hydroxide solution are separated, and it is believed that the sodium hydroxide is unlikely to move to the solvent. In that case, it is believed that the aqueous sodium hydroxide solution added as the alkali metal hydroxide is unlikely to contribute to promoting the reaction. On the other hand, when the reaction is carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst, the alkali metal hydroxide is transferred to the solvent while being incorporated in the phase transfer catalyst, and the aqueous sodium hydroxide solution is likely to contribute to promoting the reaction. Therefore, when the reaction is carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst, the reaction is believed to proceed more favorably.

[0162] The phase transfer catalyst is not particularly limited, but examples thereof include quaternary ammonium salts such as tetra-n-butylammonium bromide.

[0163] When the resin composition used in the present embodiment contains the modified polyphenylene ether compound, it preferably contains the modified polyphenylene ether compound obtained as described above.

[0164] (Each content) The content of the free radical compound is preferably 0.01 to 0.4 parts by mass, more preferably 0.05 to 0.3 parts by mass, and even more preferably 0.1 to 0.2 parts by mass, relative to 100 parts by mass of the total of the polymer and the curing agent in the resin composition. If the content of the free radical compound is within the above range, it is considered that a cured product having low dielectric properties and high heat resistance and capable of more suitably maintaining low dielectric properties even after heat treatment and / or water absorption treatment can be obtained, and a resin composition having excellent moldability can be more reliably obtained.

[0165] The content of the polymer is preferably 10 to 95 parts by mass, more preferably 15 to 90 parts by mass, and even more preferably 20 to 90 parts by mass, based on 100 parts by mass of the resin component (organic component) in the resin composition. That is, the content of the modified polyphenylene ether compound is preferably 10 to 95% by mass based on the components other than the inorganic filler in the resin composition.

[0166] As described above, the resin composition may contain the curing agent, and when the resin composition contains the curing agent, for example, the content of the curing agent is preferably 5 to 50 parts by mass, more preferably 10 to 50 parts by mass, relative to 100 parts by mass of the resin component (organic component) in the resin composition. Also, the content of the curing agent is preferably 5 to 50 parts by mass, more preferably 10 to 50 parts by mass, relative to 100 parts by mass of the total of the polymer and the curing agent.

[0167] When the content of each of the polymer and the curing agent is within the above range, the cured product of the resin composition has excellent heat resistance. This is believed to be because the curing reaction between the polymer and the curing agent proceeds favorably.

[0168] When the resin composition further contains the modified polyphenylene ether compound, the polymer, the modified polyphenylene ether compound, and the curing agent are preferably contained in the following amounts.

[0169] The total content of the polymer and the modified polyphenylene ether compound is preferably 10 to 95 parts by mass, more preferably 15 to 90 parts by mass, and even more preferably 20 to 90 parts by mass, based on 100 parts by mass of the resin component (organic component) in the resin composition. That is, the total content of the polymer and the modified polyphenylene ether compound is preferably 10 to 95% by mass based on the resin component (organic component) in the resin composition.

[0170] When the contents of the polymer and the modified polyphenylene ether compound are within the above ranges, a resin composition having excellent dielectric properties and moldability can be obtained.

[0171] When the resin composition of the present embodiment contains the reaction initiator, its content is not particularly limited, but for example, it is preferably 0.5 to 8.0 parts by mass, more preferably 0.5 to 5.0 parts by mass, and even more preferably 0.5 to 2.0 parts by mass, relative to 100 parts by mass of the total mass of the polymer and the curing agent (and the modified polyphenylene ether compound). If the content of the reaction initiator is too small, the curing reaction between the polymer and the curing agent tends not to start properly. Also, if the content of the initiator is too large, the dielectric tangent of the cured product of the obtained prepreg tends to increase, making it difficult to exhibit excellent low dielectric properties. Therefore, if the content of the reaction initiator is within the above range, a cured product of a prepreg having excellent low dielectric properties can be obtained.

[0172] When the resin composition of the present embodiment contains the reaction initiator, the ratio (mass ratio) of the free radical compound to the reaction initiator in the resin composition is preferably about 0.005:1 to 0.2:1.0 (free radical compound: reaction initiator), more preferably about 0.01:1.0 to 0.2:1.0, and even more preferably about 0.1:1.0 to 0.2:1.0. It is believed that the effect of the present invention can be obtained more reliably.

[0173] Furthermore, when the resin composition of the present embodiment contains an inorganic filler, the content thereof (filler content) is preferably 30 to 270 mass %, and more preferably 50 to 250 mass %, relative to the resin composition.

[0174] (Other Ingredients) The resin composition according to the present embodiment may contain components other than the above-mentioned components (other components) as necessary, as long as the effects of the present invention are not impaired. The other components contained in the resin composition according to the present embodiment may further contain additives such as, for example, a reaction accelerator, a catalyst, a dispersant, a leveling agent, a silane coupling agent, a flame retardant, an antifoaming agent, an antioxidant, a heat stabilizer, an antistatic agent, an ultraviolet absorber, a dye or a pigment, and a lubricant. In addition to the modified polyphenylene ether compound, the curing agent, and the polymer, the resin composition may contain a thermosetting resin such as polyphenylene ether or an epoxy resin.

[0175] The resin composition according to the present embodiment may contain a flame retardant as described above. By containing a flame retardant, the flame retardancy of the cured product of the resin composition can be improved. The flame retardant is not particularly limited. Specifically, in fields where halogen-based flame retardants such as bromine-based flame retardants are used, for example, ethylene dipentabromobenzene, ethylene bistetrabromoimide, decabromodiphenyl oxide, and tetradecabromodiphenoxybenzene having a melting point of 300° C. or more are preferred. It is considered that the use of a halogen-based flame retardant can suppress the detachment of halogen at high temperatures and suppress the decrease in heat resistance. In addition, in fields where halogen-free is required, phosphorus-containing flame retardants and the like can be mentioned. Specifically, for example, phosphate ester-based flame retardants, phosphazene-based flame retardants, bisdiphenylphosphine oxide-based flame retardants, and phosphinate-based flame retardants can be mentioned. A specific example of a phosphate ester-based flame retardant is a condensed phosphate ester of dixylenyl phosphate. A specific example of a phosphazene-based flame retardant is phenoxyphosphazene. A specific example of the bisdiphenylphosphine oxide flame retardant is xylylenebisdiphenylphosphine oxide. A specific example of the phosphinate flame retardant is a metal phosphinate of an aluminum salt of dialkylphosphinic acid. As the flame retardant, each of the flame retardants exemplified above may be used alone or in combination of two or more.

[0176] (Manufacturing method) The method for producing the resin composition is not particularly limited, and examples thereof include a method of mixing the polymer and the free radical compound with other components as necessary, etc. Specifically, in the case of obtaining a varnish-like composition containing an organic solvent, the method described in the description of the prepreg described later can be used.

[0177] In the resin composition of the present embodiment, the minimum melt viscosity (T2) and the melt viscosity (T1) at a temperature 10°C above the minimum melt viscosity are preferably T1 / T2=5.0 or less. This is believed to have the advantage of further improving moldability. More preferably, the ratio is more than 1.0 and not more than 2.0.

[0178] Furthermore, it is preferable that the T2 is 14000 (poise) or less and the T1 is 15000 (poise) or less. This is because it is believed that the resin composition is easily filled into the pattern and the moldability is improved. Furthermore, it is particularly preferable that the T2 is 8000 (poise) or less and the T1 is 10000 (poise) or less.

[0179] Furthermore, the resin composition of this embodiment, in its cured form, preferably has a dielectric loss tangent (10 GHz) of 0.0024 or less, and more preferably 0.0020 or less.

[0180] Furthermore, when the cured product of the resin composition of this embodiment is subjected to moisture absorption treatment (treatment for 120 hours in an environment of a temperature of 85°C and a humidity of 85%) with reference to JIS C 6481 (1996) and the difference in dielectric tangent from that of the cured product before treatment is measured, it is preferable that (dielectric tangent after moisture absorption treatment) - (dielectric tangent before moisture absorption treatment) is 0.0010 or less, more preferably 0.0009 or less, and even more preferably 0.0006 or less.

[0181] Furthermore, when a cured product of the resin composition of this embodiment is held (heat-treated) at 130° C. for 120 hours and the dielectric loss tangent of the heat-treated cured product (dielectric loss tangent after heat treatment) is measured to determine the difference between the dielectric loss tangent of the cured product before the treatment, it is preferable that (dielectric loss tangent after heat treatment)−(dielectric loss tangent before heat treatment) is 0.0012 or less, and more preferably 0.0010 or less.

[0182] Furthermore, by using the resin composition according to this embodiment, it is possible to obtain a prepreg, a metal-clad laminate, a wiring board, a metal foil with resin, and a film with resin, as follows: In the following description, each reference symbol indicates: 1 prepreg, 2 resin composition or semi-cured resin composition, 3 fibrous base material, 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, and 43 support film.

[0183] [Prepreg] FIG. 1 is a schematic cross-sectional view showing an example of a prepreg 1 according to an embodiment of the present invention.

[0184] 1, the prepreg 1 according to this embodiment includes the resin composition or a semi-cured product of the resin composition 2, and a fibrous base material 3. This prepreg 1 includes the resin composition or a semi-cured product of the resin composition 2, and the fibrous base material 3 present in the resin composition or the semi-cured product of the resin composition 2.

[0185] In this embodiment, the semi-cured product is a product in a state where the resin composition is partially cured to such an extent that the resin composition can be further cured. That is, the semi-cured product is a product in a semi-cured state (B-staged) of the resin composition. For example, when the resin composition is heated, the viscosity first gradually decreases, and then curing starts, and then curing starts, and the viscosity gradually increases. In such a case, the semi-cured state may be a state between when the viscosity starts to increase and when the resin composition is completely cured.

[0186] In addition, the prepreg obtained by using the resin composition according to the present embodiment may be a prepreg having a semi-cured product of the resin composition as described above, or may be a prepreg having the uncured resin composition itself. That is, it may be a prepreg having a semi-cured product of the resin composition (the resin composition in the B stage) and a fibrous base material, or a prepreg having the resin composition before curing (the resin composition in the A stage) and a fibrous base material. In addition, the resin composition or the semi-cured product of the resin composition may be a product obtained by drying or heating the resin composition.

[0187] When producing a prepreg, the resin composition 2 is often prepared in a varnish form and used to impregnate the fibrous base material 3, which is a base material for forming the prepreg. That is, the resin composition 2 is usually often a resin varnish prepared in a varnish form. Such a varnish-like resin composition (resin varnish) is prepared, for example, as follows.

[0188] First, each component of the resin composition that can be dissolved in an organic solvent is put into the organic solvent and dissolved. At this time, heating may be performed as necessary. Then, a component that is not dissolved in the organic solvent (e.g., inorganic filler, etc.) that is used as necessary is added, and the mixture is dispersed until a predetermined dispersion state is reached using a ball mill, a bead mill, a planetary mixer, a roll mill, etc., to prepare a varnish-like resin composition. The organic solvent used here is not particularly limited as long as it dissolves the modified polyphenylene ether compound and the curing agent and does not inhibit the curing reaction. Specific examples include toluene and methyl ethyl ketone (MEK).

[0189] The method for producing the prepreg is not particularly limited as long as the prepreg can be produced. Specifically, when producing the prepreg, the resin composition used in the present embodiment described above is often prepared in a varnish form and used as a resin varnish, as described above.

[0190] Specific examples of the fibrous substrate include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper. The use of glass cloth provides a laminate with excellent mechanical strength, and flattened glass cloth is particularly preferred. A specific example of the flattening process is a method in which glass cloth is continuously pressed with a press roll at an appropriate pressure to compress the yarn into a flat shape. The thickness of the fibrous substrate generally used is, for example, 0.01 mm or more and 0.3 mm or less.

[0191] The method for producing the prepreg is not particularly limited as long as the prepreg can be produced. Specifically, when producing the prepreg, the resin composition according to the present embodiment described above is often prepared in a varnish form and used as a resin varnish, as described above.

[0192] As a method for producing the prepreg 1, for example, a method of impregnating a fibrous substrate 3 with a resin composition 2, for example, a resin composition 2 prepared in a varnish form, and then drying the same can be mentioned. The resin composition 2 is impregnated into the fibrous substrate 3 by immersion, coating, or the like. Impregnation can be repeated multiple times as necessary. In addition, at this time, by repeating the impregnation using multiple resin compositions with different compositions and concentrations, it is also possible to adjust to the final desired composition and impregnation amount.

[0193] 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. By heating, a prepreg 1 in an uncured (A stage) or semi-cured (B stage) state is obtained. The organic solvent can be volatilized from the resin varnish by the heating, thereby reducing or removing the organic solvent.

[0194] The resin composition according to the present embodiment or a prepreg comprising a semi-cured product of this resin composition is a prepreg from which a cured product that has low dielectric properties and high heat resistance and can favorably maintain its low dielectric properties even after heat treatment or water absorption treatment can be favorably obtained. Furthermore, it has good moldability and, when used for wiring boards, etc., has excellent filling properties into circuit patterns.

[0195] [Metal-clad laminate] FIG. 2 is a schematic cross-sectional view showing an example of a metal-clad laminate 11 according to an embodiment of the present invention.

[0196] As shown in FIG. 2, the metal-clad laminate 11 is composed of an insulating layer 12 containing a cured product of the prepreg 1 shown in FIG. 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 a cured product of the resin composition, or may be made of a cured product of the prepreg. The thickness of the metal foil 13 varies depending on the performance required for the final wiring board, and is not particularly limited. The thickness of the metal foil 13 can be appropriately set depending on 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 when the metal foil is thin, it may be a carrier-attached copper foil having a release layer and a carrier to improve handling properties.

[0197] The method for producing the metal-clad laminate 11 is not particularly limited as long as the metal-clad laminate 11 can be produced. Specifically, a method for producing the metal-clad laminate 11 using a prepreg 1 can be mentioned. As this method, a method for producing a double-sided or single-sided metal-foil-clad laminate 11 can be mentioned, in which one or more prepregs 1 are stacked, and a metal foil 13 such as a copper foil is stacked on both sides or one side of the prepreg 1, and the metal foil 13 and the prepreg 1 are heated and pressurized to be laminated and integrated. That is, the metal-clad laminate 11 is obtained by stacking the metal foil 13 on the prepreg 1 and heating and pressurizing it. In addition, the heating and pressing conditions can be appropriately set depending on the thickness of the metal-clad laminate 11 to be produced and the type of composition of the prepreg 1. For example, the temperature can be 170 to 210°C, the pressure can be 3.5 to 4 MPa, and the time can be 60 to 150 minutes. In addition, the metal-clad laminate may be produced without using a prepreg. For example, a method may be mentioned in which a varnish-like resin composition is applied onto a metal foil to form a layer containing the resin composition on the metal foil, and then the layer is heated and pressed.

[0198] The metal-clad laminate having an insulating layer containing the cured product of the resin composition according to the present embodiment is a metal-clad laminate having an insulating layer that has low dielectric properties and high heat resistance, and can favorably maintain its low dielectric properties even after heat treatment or water absorption treatment. Furthermore, it has good moldability, and when used for a wiring board or the like, it also has excellent filling properties into a circuit pattern.

[0199] [Wiring board] FIG. 3 is a schematic cross-sectional view showing an example of wiring board 21 according to an embodiment of the present invention.

[0200] As shown in Fig. 3, wiring board 21 according to this embodiment is composed of insulating layer 12 used by curing prepreg 1 shown in Fig. 1, and wiring 14 laminated together with insulating layer 12 and formed by partially removing metal foil 13. That is, wiring board 21 has insulating layer 12 containing a cured product of a resin composition, and wiring 14 provided on insulating layer 12. In addition, insulating layer 12 may be made of a cured product of the resin composition, or may be made of a cured product of the prepreg.

[0201] The method for producing the wiring board 21 is not particularly limited as long as the wiring board 21 can be produced. Specifically, a method for producing the wiring board 21 using the prepreg 1 can be mentioned. For example, the method includes a method for producing the wiring board 21 in which wiring is provided as a circuit on the surface of the insulating layer 12 by etching the metal foil 13 on the surface of the metal-clad laminate 11 produced as described above. That is, the wiring board 21 is obtained by forming a circuit by partially removing the metal foil 13 on the surface of the metal-clad laminate 11. In addition to the above methods, examples of the method for forming a circuit include circuit formation by a semi-additive process (SAP) or a modified semi-additive process (MSAP). The wiring board 21 has an insulating layer 12 that has low dielectric properties and high heat resistance, and can favorably maintain low dielectric properties even after a water absorption treatment.

[0202] Such a wiring board is a wiring board having an insulating layer that has low dielectric properties and high heat resistance, and can favorably maintain low dielectric properties even after heat treatment or water absorption treatment. Furthermore, the resin composition of this embodiment has good moldability and exhibits good filling properties in the circuit pattern of the wiring board. Therefore, it has the advantage that it can be used in wiring boards in which the distance between conductor circuits (wiring) is narrow. The resin composition of this embodiment is not particularly limited, but can be favorably used in wiring boards in which a conductor circuit pattern is provided with a distance between the conductor circuits of at least a part of the conductor circuits, for example, 50 μm or less.

[0203] In particular, the wiring board of this embodiment may be a multilayer wiring board having two or more circuit layers, and the resin composition of this embodiment can be suitably used as an interlayer insulating material for the multilayer wiring board. Although not particularly limited, for example, it may be a multilayer wiring board having two or more circuit layers, in which a wiring pattern is provided in which the distance between the wirings is 50 μm or less in at least a part of the wiring. Furthermore, for example, a wiring pattern in which the distance between the wirings is 30 μm or less in at least a part of the wiring may be provided.

[0204] In addition, the resin composition of the present embodiment is preferably used as an insulating material for an insulating layer of a highly multilayered wiring board having 5 or more circuit layers, or even 10 or more circuit layers, although it is not particularly limited thereto. In the manufacture of a highly multilayered wiring board having 5 or more circuit layers, or even 10 or more circuit layers, the interlayer insulating material of the present embodiment can be used to stably embed each inner layer circuit in the multilayering process for forming each interlayer insulating layer, and excellent moldability can be ensured. By ensuring excellent moldability, when a highly multilayered wiring board having 5 or more circuit layers, or even 10 or more circuit layers, is subjected to high-temperature treatment after absorbing moisture, for example, separation at the adhesive surface between the inner layer circuit of the multilayered wiring board and the interlayer insulating layer can be prevented.

[0205] [Metal foil with resin] FIG. 4 is a schematic cross-sectional view showing an example of a resin-coated metal foil 31 according to the present embodiment.

[0206] 4, the resin-coated metal foil 31 according to this embodiment includes 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 includes the resin layer 32 and the metal foil 13 laminated together with the resin layer 32. The resin-coated metal foil 31 may also include another layer between the resin layer 32 and the metal foil 13.

[0207] The resin layer 32 may contain the semi-cured product of the resin composition as described above, or may contain the resin composition that has not been cured. That is, the resin-attached metal foil 31 may include a resin layer containing the semi-cured product of the resin composition (the resin composition in the B stage) and a metal foil, or may be a resin-attached metal foil that includes a resin layer containing the resin composition before curing (the resin composition in the A stage) and a metal foil. The resin layer may contain the resin composition or the 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 heated and dried. The fibrous substrate may be the same as the fibrous substrate of the prepreg.

[0208] The metal foil may be any metal foil used in metal-clad laminates, including, for example, copper foil and aluminum foil.

[0209] The resin-coated metal foil 31 and the resin-coated film 41 may be provided with a cover film or the like as necessary. By providing a cover film, it is possible to prevent the inclusion of foreign matter, etc. The cover film is not particularly limited, but examples thereof include polyolefin film, polyester film, polymethylpentene film, and films formed by providing a release agent layer on these films.

[0210] The method for producing the resin-coated metal foil 31 is not particularly limited as long as the resin-coated metal foil 31 can be produced. Examples of the method for producing the resin-coated metal foil 31 include a method of producing the resin-coated metal foil 31 by 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 by using a bar coater, for example. The applied resin composition is heated, for example, under conditions of 80° C. or higher and 180° C. or lower, and 1 minute or longer and 10 minutes or shorter. The heated resin composition is formed on the metal foil 13 as an uncured resin layer 32. The organic solvent can be volatilized from the resin varnish by the heating, thereby reducing or removing the organic solvent.

[0211] The resin-attached metal foil having a resin layer containing the resin composition according to the present embodiment or a semi-cured product of this resin composition is a resin-attached metal foil that can be used to obtain a cured product that has low dielectric properties and high heat resistance, and can maintain low dielectric properties even after heat treatment or water absorption treatment. Furthermore, it has good moldability, and when used for wiring boards, it is also excellent in filling the circuit pattern. For example, a multi-layer wiring board can be manufactured by stacking it on a wiring board.

[0212] [Resin-coated film] FIG. 5 is a schematic cross-sectional view showing an example of a resin-coated film 41 according to the present embodiment.

[0213] 5, the resin-attached film 41 according to this embodiment includes a resin layer 42 containing the resin composition or a semi-cured product of the resin composition, and a support film 43. This resin-attached film 41 includes the resin layer 42 and the support film 43 laminated together with the resin layer 42. The resin-attached film 41 may also include another layer between the resin layer 42 and the support film 43.

[0214] The resin layer 42 may contain the semi-cured product of the resin composition as described above, or may contain the resin composition that has not been cured. That is, the resin-attached film 41 may include a resin layer containing the semi-cured product of the resin composition (the resin composition in the B stage) and a support film, or may be a resin-attached film including a resin layer containing the resin composition before curing (the resin composition in the A stage) and a support film. The resin layer may contain the resin composition or the 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 heated and dried. The fibrous substrate may be the same as the fibrous substrate of the prepreg.

[0215] Furthermore, any support film used for a resin-attached film can be used without any limitation as the support film 43. Examples of the support film include electrically insulating films such as polyester film, polyethylene terephthalate (PET) film, polyimide film, polyparabanic acid film, polyether ether ketone film, polyphenylene sulfide film, polyamide film, polycarbonate film, and polyarylate film.

[0216] The resin-attached film 41 may be provided with a cover film or the like as necessary. By providing a cover film, it is possible to prevent the inclusion of foreign matter, etc. The cover film is not particularly limited, but examples thereof include a polyolefin film, a polyester film, and a polymethylpentene film.

[0217] The support film and the cover film may be subjected to surface treatment such as matte treatment, corona treatment, release treatment, and roughening treatment, if necessary.

[0218] The method for producing the resin-attached film 41 is not particularly limited as long as the resin-attached film 41 can be produced. Examples of the method for producing the resin-attached film 41 include a method in which the varnish-like resin composition (resin varnish) is applied onto the support film 43 and heated. The varnish-like resin composition is applied onto the support film 43 by using a bar coater, for example. The applied resin composition is heated under conditions of 80° C. or higher and 180° C. or lower, and 1 minute or longer and 10 minutes or shorter. The heated resin composition is formed on the support film 43 as an uncured resin layer 42. The organic solvent can be volatilized from the resin varnish by the heating, thereby reducing or removing the organic solvent.

[0219] The resin-attached film having a resin layer containing the resin composition according to the present embodiment or a semi-cured product of this resin composition is a resin-attached film that can be suitably obtained as a cured product that has low dielectric properties and high heat resistance, and can suitably maintain low dielectric properties even after heat treatment or water absorption treatment. Furthermore, it has good moldability, and when used for wiring boards, it also has excellent filling properties into circuit patterns. For example, a multilayer wiring board can be manufactured by laminating the film on a wiring board and then peeling off the support film, or laminating the film on a wiring board after peeling off the support film.

[0220] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples. EXAMPLES

[0221] [Examples 1 to 15 and Comparative Examples 1 to 5] In the present examples, each component used in preparing the resin composition will be described.

[0222] (Resin component) Polymer 1: 2.9 mol (377 g) of divinylbenzene, 1.7 mol (224.4 g) of ethylvinylbenzene, 10.4 mol (1081.6 g) of styrene, and 15 mol (1532 g) of n-propyl acetate were placed in a 5.0 L reactor, and 600 mmol of boron trifluoride diethyl ether complex was added at 70°C and reacted for 4 hours. After the polymerization solution was stopped with an aqueous solution of sodium bicarbonate, the oil layer was washed three times with pure water, and the volatile matter was removed under reduced pressure at 60°C to recover and obtain polymer 1.

[0223] Polymer 1, which has a structural unit represented by the formula (1) in the molecule, is an aromatic polymer having a structural unit derived from a bifunctional aromatic compound in which two carbon-carbon unsaturated double bonds are bonded to an aromatic ring, and is a compound having structural units represented by the formulas (12) to (14). The weight average molecular weight Mw is 26,300. In addition, polymer 1 represented by the formula (1), R 1 ~R 3 The equivalent weight (vinyl equivalent) of the vinyl group contained in the structural unit in which is a hydrogen atom is 510.

[0224] Polymer 2: 3.6 mol (468 g) of divinylbenzene, 2.2 mol (290.4 g) of ethylvinylbenzene, 9.2 mol (956.8 g) of styrene, and 15 mol (1532 g) of n-propyl acetate were placed in a 5.0 L reactor, and 600 mmol of boron trifluoride diethyl ether complex was added at 70°C and reacted for 4 hours. After the polymerization solution was stopped with an aqueous solution of sodium bicarbonate, the oil layer was washed three times with pure water, and the copolymer 2 was recovered and obtained by degassing at 60°C.

[0225] Polymer 2, which has a structural unit represented by the formula (1) in the molecule, is an aromatic polymer having a structural unit derived from a bifunctional aromatic compound in which two carbon-carbon unsaturated double bonds are bonded to an aromatic ring, and is a compound having structural units represented by the formulas (12) to (14). The weight average molecular weight Mw is 31100. In addition, polymer 2 represented by the formula (1), R 1 ~R 3 The equivalent weight (vinyl equivalent) of the vinyl group contained in the structural unit in which is a hydrogen atom is 380.

[0226] Polymer 3: 3.9 mol (507 g) of divinylbenzene, 2.3 mol (303.6 g) of ethylvinylbenzene, 8.8 mol (915.2 g) of styrene, and 15 mol (1532 g) of n-propyl acetate were placed in a 5.0 L reactor, and 600 mmol of boron trifluoride diethyl ether complex was added at 70°C and reacted for 4 hours. After the polymerization solution was stopped with an aqueous solution of sodium bicarbonate, the oil layer was washed three times with pure water, and the volatile matter was removed under reduced pressure at 60°C to recover and obtain copolymer 3.

[0227] Polymer 3 is a polymer having a structural unit represented by the above formula (1) in the molecule: an aromatic polymer having a structural unit derived from a bifunctional aromatic compound in which two carbon-carbon unsaturated double bonds are bonded to an aromatic ring, and is a compound having structural units represented by the above formulas (12) to (14). The weight average molecular weight Mw is 39,500. In addition, the polymer represented by the above formula (1), R 1 ~R 3 The equivalent weight (vinyl equivalent) of the vinyl group contained in the structural unit in which is a hydrogen atom is 320.

[0228] In addition, the polymers 1 to 3 are represented by the above formula (1), and R 1 ~R 3 The vinyl equivalent of the vinyl group contained in the structural unit in which is a hydrogen atom (vinyl equivalent) was calculated by iodine value measurement by the Wiess method. Specifically, the compound to be measured was first dissolved in chloroform to a concentration of 0.3 g / 30 mL. An excess amount of iodine chloride was added to the double bonds present in this solution. By doing so, the double bonds react with iodine chloride, and after this reaction has progressed sufficiently, the iodine remaining in the solution after the reaction is converted to I by adding a 20% by mass aqueous potassium iodide solution to the solution after the reaction. 3 - This I was extracted into the aqueous phase. 3 - The aqueous phase into which was extracted was titrated with an aqueous sodium thiosulfate solution (0.1 mol / L sodium thiosulfate standard solution) to calculate the iodine value. The following formula was used to calculate the iodine value.

[0229] Iodine value = [(BA) x F x 1.269] / mass of compound (g) In the above formula, B represents the titer (cc) of 0.1 mol / L sodium thiosulfate standard solution required for the blank test, A represents the titer (cc) of 0.1 mol / L sodium thiosulfate standard solution required for neutralization, and F represents the titer of sodium thiosulfate.

[0230] Modified PPE: Modified polyphenylene ether obtained by reacting polyphenylene ether with chloromethylstyrene. Specifically, it is a modified polyphenylene ether obtained by the following reaction.

[0231] First, 200 g of polyphenylene ether (SA90 manufactured by SABIC Innovative Plastics, 2 terminal hydroxyl groups, weight average molecular weight Mw1700), 30 g of a mixture of p-chloromethylstyrene and m-chloromethylstyrene in a mass ratio of 50:50 (chloromethylstyrene: CMS manufactured by Tokyo Chemical Industry Co., Ltd.), 1.227 g of tetra-n-butylammonium bromide as a phase transfer catalyst, and 400 g of toluene were charged and stirred in a 1-liter three-neck flask equipped with a temperature controller, a stirrer, a cooling device, and a dropping funnel. Then, the mixture was stirred until the polyphenylene ether, chloromethylstyrene, and tetra-n-butylammonium bromide were dissolved in the toluene. At that time, the mixture was gradually heated until the liquid temperature finally reached 75°C. Then, an aqueous sodium hydroxide solution (20 g sodium hydroxide / 20 g water) was dropped into the solution as an alkali metal hydroxide over 20 minutes. After that, the mixture was further stirred at 75°C for 4 hours. Next, the contents of the flask were neutralized with 10% by mass of hydrochloric acid, and then a large amount of methanol was added. This caused a precipitate to form in the liquid in the flask. In other words, the product contained in the reaction liquid in the flask was reprecipitated. The precipitate was then removed by filtration, washed three times with a mixture of methanol and water in a mass ratio of 80:20, and then dried at 80°C for three hours under reduced pressure.

[0232] The obtained solid is 1H-NMR (400 MHz, CDCl 3 The solid was analyzed by NMR (TMS). As a result of NMR measurement, a peak derived from a vinylbenzyl group (ethenylbenzyl group) was confirmed at 5 to 7 ppm. This confirmed that the obtained solid was a modified polyphenylene ether compound having a vinylbenzyl group (ethenylbenzyl group) in the molecule as the substituent at the molecular end. Specifically, it was confirmed that the solid was an ethenylbenzyl-modified polyphenylene ether. The obtained modified polyphenylene ether compound is represented by the above formula (18), in which Y is a dimethylmethylene group (represented by formula (16), and R in formula (16) 33 and R 34 is a methyl group), Z is a phenylene group, and R 1 ~R 3 was a hydrogen atom, n was 1, and p was 1.

[0233] The number of terminal functional groups of the modified polyphenylene ether was measured as follows.

[0234] First, the modified polyphenylene ether was accurately weighed. The weight was designated as X (mg). The weighed modified polyphenylene ether was dissolved in 25 mL of methylene chloride, and 100 μL of a 10 mass% tetraethylammonium hydroxide (TEAH) ethanol solution (TEAH:ethanol (volume ratio) = 15:85) was added to the solution, and then the absorbance (Abs) at 318 nm was measured using a UV spectrophotometer (UV-1600 manufactured by Shimadzu Corporation). From the measurement results, the number of terminal hydroxyl groups of the modified polyphenylene ether was calculated using the following formula.

[0235] Residual OH amount (μmol / g) = [(25×Abs) / (ε×OPL×X)]×10 6 Here, ε is the extinction coefficient, 4700 L / mol cm, and OPL is the cell path length, 1 cm.

[0236] And, since the calculated residual OH amount (number of terminal hydroxyl groups) of the modified polyphenylene ether was almost zero, it was found that the hydroxyl groups of the polyphenylene ether before modification were almost all modified. From this, it was found that the reduction from the number of terminal hydroxyl groups of the polyphenylene ether before modification was the number of terminal hydroxyl groups of the polyphenylene ether before modification. In other words, it was found that the number of terminal hydroxyl groups of the polyphenylene ether before modification was the number of terminal functional groups of the modified polyphenylene ether. In other words, the number of terminal functional groups was 2.

[0237] The intrinsic viscosity (IV) of the modified polyphenylene ether was measured in methylene chloride at 25° C. Specifically, the intrinsic viscosity (IV) of the modified polyphenylene ether was measured by using a viscometer (AVS500 Visco System manufactured by Schott) for a 0.18 g / 45 ml methylene chloride solution (liquid temperature 25° C.) of the modified polyphenylene ether. As a result, the intrinsic viscosity (IV) of the modified polyphenylene ether was 0.086 dl / g.

[0238] The molecular weight distribution of the modified polyphenylene ether was measured by GPC. The weight average molecular weight (Mw) was calculated from the molecular weight distribution. As a result, Mw was 2,300.

[0239] (hardening agent) Acenaphthylene: Acenaphthylene manufactured by JFE Chemical Corporation Maleimide compound: N-phenyl monomaleimide manufactured by Nippon Shokubai Co., Ltd.

[0240] (Reaction initiator) Azo initiator: Fujifilm Wako Pure Chemical's "VR-110" Peroxide initiator: PBP (1,3-bis(butylperoxyisopropyl)benzene; Perbutyl P manufactured by NOF Corporation)

[0241] (Free radical compounds) Free radical compound 1: A free radical compound represented by the following formula ("H0865" manufactured by Tokyo Chemical Industry Co., Ltd.)

[0242] [ka]

[0243] Free radical compound 2: A free radical compound represented by the following formula ("T3751" manufactured by Tokyo Chemical Industry Co., Ltd.)

[0244] [ka]

[0245] Free radical compound 3: A free radical compound represented by the following formula ("H0878" manufactured by Tokyo Chemical Industry Co., Ltd.)

[0246] [ka]

[0247] Free radical compound 4: A free radical compound represented by the following formula ("B5642" manufactured by Tokyo Chemical Industry Co., Ltd.)

[0248] [ka]

[0249] Free radical compound 5: A free radical compound represented by the following formula ("C1406" manufactured by Tokyo Chemical Industry Co., Ltd.)

[0250] [ka]

[0251] Free radical compound 6: A free radical compound represented by the following formula ("D4313" manufactured by Tokyo Chemical Industry Co., Ltd.)

[0252] [ka]

[0253] Free radical compound 7: A free radical compound represented by the following formula (Tokyo Chemical Industry Co., Ltd. "G0020")

[0254] [ka]

[0255] (Catechol compounds) 4-tert-Butylcatechol: 4-tert-Butylcatechol manufactured by Tokyo Chemical Industry Co., Ltd.

[0256] (Inorganic filler) Silica filler 1: Admatechs' "SC-2300SVJ" (silica with 4.0% silanol group content) Silica filler 2: "5SV-C" manufactured by Admatechs (silica with 1.0% silanol group content)

[0257] (Preparation method) First, the above components other than the inorganic filler were added to toluene and mixed in the composition (parts by mass) shown in Table 3 so that the solid content concentration was 55% by mass. The mixture was stirred for 60 minutes. Thereafter, the inorganic filler was added to the obtained liquid, and the filler was dispersed using a bead mill. By doing so, a varnish-like resin composition (varnish) was obtained.

[0258] [Melt Viscosity] 0.5 g of the powdered semi-cured resin composition obtained from the prepreg was pressed into a pellet shape with a diameter of 1.0 cm and a height of 0.5 cm at a pressure of 2.8 MPa to prepare a measurement sample. The melting behavior of the measurement sample was measured using a Rheosol G3000NT dynamic viscoelasticity measuring device. As a measurement condition, the sample temperature was raised at a rate of 4 degrees per minute, and the viscosity (poise) of the sample at that time was measured. Then, the temperature at which the measured viscosity value was the smallest during the temperature rise process from the semi-cured state (B stage) to the cured state (C stage) was determined as the minimum melt viscosity (T2).

[0259] [T1 / T2] The melt viscosity when the temperature was raised by +10°C from the minimum melt viscosity (T2) was defined as T1, and T1 / T2 was calculated. T1 / T2 is an index for measuring the curing speed from a state where T2 was reached once during the temperature rise process (state where the viscosity is at its lowest), and a smaller T1 / T2 value means a slower curing speed, which is considered to be one of the characteristics of a resin composition with high moldability.

[0260] Next, an evaluation substrate (cured prepreg) was obtained as follows.

[0261] The obtained varnish was impregnated into a fibrous substrate (glass cloth: Asahi Kasei Corporation's 1078L, #1078 type, L glass), and then heated and dried at 120°C for 3 minutes to produce a prepreg. At that time, the content (resin content) of the components that constitute the resin by the curing reaction relative to the prepreg was adjusted to 67 mass%. Then, two sheets of each of the obtained prepregs were stacked and heated and pressurized at a temperature of 200°C for 2 hours at a pressure of 3 MPa to obtain an evaluation board (cured prepreg).

[0262] Next, an evaluation substrate (metal-clad laminate) was obtained as follows.

[0263] A fibrous substrate (glass cloth: Asahi Kasei Corporation's GC1078L, #1078 type, L glass) was impregnated with the varnish and then heated and dried for 3 minutes at 120° C. to produce a prepreg. At that time, the content of the components that constitute the resin by the curing reaction relative to the prepreg (resin content) was adjusted to 67% by mass.

[0264] Two sheets of each prepreg were stacked, and copper foil (FV-WS, 18 μm thick, from Furukawa Electric Co., Ltd.) was placed on both sides to form a pressure body. The body was heated and pressed at a temperature of 200°C and a pressure of 3 MPa for two hours to produce a copper foil-clad laminate, which was an evaluation substrate (metal-clad laminate) with copper foil adhered to both sides.

[0265] The evaluation substrates (cured prepreg and metal-clad laminate) prepared as described above were evaluated by the methods described below.

[0266] [Moldability] A lattice-shaped copper pattern of 200mm x 200mm was prepared with a residual copper ratio of 80% and a line thickness of 35μm. A 200mm x 200mm prepreg was layered on top of it. A 250mm x 250mm copper foil with a thickness of 35μm was layered on top of it. These were sandwiched between metal plates of about 3mm thickness and heated and pressed under the conditions shown below using a press machine for laminate molding. The heating conditions were raised from 30 degrees to 200 degrees at a rate of 4 degrees per minute. The pressure conditions were set so that the pressure on the prepreg was 1MPa at the start of heating, and then the pressure on the prepreg was set to 3MPa when the temperature reached 110°C, and the prepreg was cured.

[0267] As a result, cases where no gaps occurred between the lattice pattern and the cured product and the gap was filled were evaluated as "Good", and cases where gaps occurred were evaluated as "Poor." The presence or absence of gaps was judged by whether or not whitish gaps could be confirmed when the copper foil of the cured product produced with a laminate molding press was removed and light was passed through the other side.

[0268] [Dielectric tangent before moisture absorption treatment] The dielectric loss tangent of the evaluation board (cured prepreg) at 10 GHz was measured by 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 board at 10 GHz.

[0269] [Dielectric tangent after moisture absorption treatment] The evaluation board used in the measurement of the dielectric tangent before the moisture absorption treatment was subjected to moisture absorption treatment with reference to JIS C 6481 (1996), and the dielectric tangent of this moisture-absorbed evaluation board (dielectric tangent after moisture absorption) was measured in the same manner as in the measurement of the dielectric tangent before the moisture absorption treatment. Note that, as the moisture absorption treatment, the evaluation board was treated in an environment of a temperature of 85°C and a humidity of 85% for 120 hours, and then the moisture on the evaluation board was thoroughly wiped off with a dry, clean cloth, and the measurement was performed.

[0270] [Change in dielectric tangent (after moisture absorption treatment - before moisture absorption treatment)] The difference between the dielectric tangent before the moisture absorption treatment and the dielectric tangent after the moisture absorption treatment (dielectric tangent after the moisture absorption treatment - dielectric tangent before the moisture absorption treatment) was calculated.

[0271] [Dielectric tangent before heat treatment] The dielectric loss tangent of the evaluation board at 10 GHz was measured by the cavity resonator perturbation method. Specifically, a network analyzer (Keysight Technologies, Inc., N5230A) was used to measure the dielectric loss tangent of the evaluation board at 10 GHz.

[0272] [Dielectric tangent after heat treatment] The evaluation substrate used in the measurement of the dielectric tangent before the heat treatment was held (heat treated) at 130°C for 120 hours, and the dielectric tangent of this heat-treated evaluation substrate (dielectric tangent after the heat treatment) was measured in the same manner as in the measurement of the dielectric tangent before the heat treatment.

[0273] [Change in dielectric tangent (after heat treatment - before heat treatment)] The difference between the dielectric loss tangent before the heat treatment and the dielectric loss tangent after the heat treatment (=dielectric loss tangent after the heat treatment-dielectric loss tangent before the heat treatment) was calculated.

[0274] [Glass transition temperature (DMA) (Tg)] The Tg of the cured product was measured using a viscoelasticity spectrometer "DMS6100" manufactured by Seiko Instruments Inc. Dynamic viscoelasticity measurement (DMA) was performed with a bending module at a frequency of 10 Hz, and the temperature at which tan δ was maximized when the temperature was raised from room temperature to 320°C at a heating rate of 5°C / min was defined as Tg.

[0275] The results of each of the above evaluations are shown in Table 3.

[0276] [Table 3]

[0277] (Consideration) As can be seen from Table 3, in all of the examples in which the resin composition of the present invention was used, it was possible to obtain a cured product that had low dielectric properties, high heat resistance, and was not easily affected by changes in the external environment, and it was confirmed that a resin composition with moldability that allows its application to laminated wiring boards could be provided.

[0278] On the other hand, in Comparative Examples 1 to 3, which did not contain a free radical compound, the low dielectric properties could not be maintained due to the influence of changes in the external environment. Furthermore, in Comparative Example 1, which did not contain a free radical compound or a reaction initiator, hardening began quickly after the minimum melting, resulting in poor moldability. In Comparative Examples 2 and 3, similar to Comparative Example 1, hardening also progressed quickly after the minimum melting due to the effect of the addition of the reaction initiator, resulting in poor moldability.

[0279] This application is based on Japanese Patent Application No. 2019-177945, filed on September 27, 2019, the contents of which are incorporated herein by reference.

[0280] In order to express the present invention, the present invention has been described adequately and sufficiently through the embodiments with reference to specific examples and drawings, etc., but it should be recognized that those skilled in the art can easily change and / or improve the above-mentioned embodiments. Therefore, unless the changes or improvements made by those skilled in the art are at a level that departs from the scope of the claims described in the claims, the changes or improvements are interpreted as being included in the scope of the claims. [Industrial Applicability]

[0281] The present invention has wide industrial applicability in technical fields related to electronic materials and various devices using the same.

Claims

1. A polymer having a structural unit represented by the following formula (13) in the molecule: A free radical compound; and a curing agent, The free radical compound has at least one free radical group selected from the group of structures represented by the following formulas (2), (3), (4) and (5) in the molecule, and includes at least one compound selected from the compounds represented by the following formulas (6) to (8): the polymer is composed only of structural units derived from divinylbenzene, structural units derived from ethylvinylbenzene, and structural units derived from styrene, the equivalent weight of the vinyl groups contained in the structural units of the polymer is 320 to 510, and the Mw is 26,300 to 39,500; the curing agent contains at least one selected from the group consisting of a polyfunctional acrylate compound having two or more acryloyl groups in the molecule, a polyfunctional methacrylate compound having two or more methacryloyl groups in the molecule, a polyfunctional vinyl compound having two or more vinyl groups in the molecule, bromostyrene, dibromostyrene, an allyl compound having an allyl group in the molecule, a maleimide compound having a maleimide group in the molecule, and an acenaphthylene compound having an acenaphthylene structure in the molecule; the content of the free radical compound is 0.01 to 0.2 parts by mass based on the content of the polymer and the curing agent; The content of the polymer is 20 to 90 parts by mass per 100 parts by mass of the resin component (organic component) in the resin composition, The content of the curing agent is 10 to 50 parts by mass per 100 parts by mass of the total of the polymer and the curing agent; and A resin composition characterized in that the minimum melt viscosity (T2) and the melt viscosity (T1) at a temperature 10°C higher than the minimum melt viscosity temperature are such that T1 / T2 is greater than 1.0 and not greater than 5.0, and that T2 is not greater than 14,000 (poise). 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】 【Chemistry 6】 【Chemistry 7】 【Chemistry 8】 (In formula (6), X Ａ represents an amino group, a cyano group, a hydroxy group, an isothiocyanate group, a methoxy group, a carboxy group, an amido group, or a benzoyloxy group. In formula (7), X Ｂ represents a hydrogen atom, an amino group, a cyano group, a hydroxy group, an isothiocyanate group, a methoxy group, a carboxy group, an amido group, or a benzoyloxy group. In formula (8), X Ｃ represents an alkylene group, an aromatic structure, a carbonyl group, or an ether bond.) 【Chemistry 10】

2. The resin composition according to claim 1 , further comprising a reaction initiator.

3. The resin composition according to claim 2 , wherein the reaction initiator comprises at least one selected from the group consisting of a metal peroxide, an azo compound, and an organic peroxide.

4. The resin composition according to claim 2 or 3, wherein the content of the reaction initiator is 0.5 to 8.0 parts by mass per 100 parts by mass of the total of the polymer and the curing agent.

5. The resin composition according to any one of claims 2 to 4, wherein the ratio (mass ratio) of the free radical compound to the reaction initiator is 0.005:1 to 0.2:1.

0.

6. The resin composition according to any one of claims 1 to 5, further comprising an inorganic filler.

7. 7. The resin composition according to claim 1, further comprising a modified polyphenylene ether compound whose terminal is modified with a substituent having a carbon-carbon unsaturated double bond.

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

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

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

11. A metal-clad laminate comprising an insulating layer comprising a cured product of the resin composition according to any one of claims 1 to 7 or a cured product of the prepreg according to claim 8, and a metal foil.

12. A wiring board comprising an insulating layer comprising a cured product of the resin composition according to any one of claims 1 to 7 or a cured product of the prepreg according to claim 8, and wiring.

13. The wiring board according to claim 12 , comprising a plurality of insulating layers, and the wiring is disposed between the insulating layers.

14. The resin composition according to claim 1, wherein T1 is 15,000 (poise) or less.

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