Thermosetting resin, cured product thereof, and thermosetting composition

Abstract

Provided is a thermosetting resin which can maintain a low melt viscosity while having both dielectric properties and a glass transition temperature. A thermosetting resin according to an embodiment is a linear copolymer and has a repeating unit corresponding to a monovinyl monocyclic aromatic compound, a repeating unit corresponding to a divinyl aromatic compound, and a repeating unit corresponding to a monovinyl polycyclic aromatic compound.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to a thermosetting resin, a cured product thereof, and a thermosetting composition containing the same. BACKGROUND

[0002] In recent years, electronic devices are being developed in terms of miniaturization and high performance, and the performance required for various materials used in conjunction therewith is also increasing. For example, a printed board material having a low dielectric loss tangent that can cope with high frequency communication is required.

[0003] For example, in Patent Literature 1 and Patent Literature 2, a linear vinyl copolymer having a repeating unit corresponding to a monovinyl aromatic compound and a repeating unit corresponding to a divinyl aromatic compound is disclosed as a thermosetting resin that can obtain a cured product having excellent dielectric properties. In these documents, styrene and vinyl naphthalene are exemplified as the monovinyl aromatic compound. However, there is no disclosure of a case where a monovinyl monocyclic aromatic compound, a divinyl aromatic compound, and a monovinyl polycyclic aromatic compound are used as constituent monomers to achieve a balance between dielectric properties and glass transition temperature while maintaining a low melt viscosity.

[0004] On the other hand, in Patent Literature 3, a copolymer of vinyl naphthalene, styrene, and divinyl biphenyl is disclosed as a high refractive resin crosslinking body for optical materials. However, since this copolymer is polymerized using a mixed solution of these monomers, the obtained copolymer has a branched chain.

[0005] Prior Art Documents

[0006] Patent Literature

[0007] Patent Literature 1: Japanese Patent Laid-Open No. 2022-052522

[0008] Patent Literature 2: Japanese Patent No. 7017662

[0009] Patent Literature 3: Japanese Patent Laid-Open No. Hei 08-092322 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] Existing thermosetting resins are not necessarily satisfactory in terms of dielectric properties, and even those having excellent dielectric properties have problems such as low glass transition temperature, high melt viscosity, and poor processability.

[0012] In view of the above, an object of embodiments of the present application is to provide a thermosetting resin that can achieve a balance between dielectric properties and glass transition temperature while maintaining a low melt viscosity.

[0013] Technical means for solving the problem

[0014] The present application includes the embodiments shown below.

[0015] [1] A thermosetting resin which is a linear copolymer and has a repeating unit corresponding to a monovinyl mononuclear aromatic compound, a repeating unit corresponding to a divinyl aromatic compound, and a repeating unit corresponding to a monovinyl polynuclear aromatic compound.

[0016] [2] The thermosetting resin according to [1], wherein the content of the above-mentioned repeating unit corresponding to a monovinyl polynuclear aromatic compound is 20 to 80 mol% in 100 mol% of the total repeating units.

[0017] [3] The thermosetting resin according to [1] or [2], wherein the linear copolymer has a structure of a polymerization initiator derived from general formula (1) at the terminal thereof: R 1 -N=N-R 2 wherein R 1 and R 2 each independently represent a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group.

[0018] [4] The thermosetting resin according to any one of [1] to [3], wherein the total content of the above-mentioned repeating unit corresponding to a monovinyl mononuclear aromatic compound, the above-mentioned repeating unit corresponding to a divinyl aromatic compound, and the above-mentioned repeating unit corresponding to a monovinyl polynuclear aromatic compound is 80 mol% or more in 100 mol% of the total repeating units.

[0019] [5] The thermosetting resin according to any one of [1] to [4], wherein the number of rings of the above-mentioned monovinyl polynuclear aromatic compound is 3 or less.

[0020] [6] A cured product which is cured from the thermosetting resin according to any one of [1] to [5].

[0021] [7] A thermosetting composition comprising the thermosetting resin according to any one of [1] to [5].

[0022] [8] The thermosetting composition according to [7], which is a printed board material.

[0023] Effects of the Invention

[0024] According to the embodiments of the present application, a thermosetting resin which can take into account both dielectric properties and glass transition temperature, and which has low melt viscosity, can be obtained. DETAILED DESCRIPTION

[0025] The thermosetting resin of the present embodiment is a copolymer having (A) a repeating unit corresponding to a monovinyl mononuclear aromatic compound, (B) a repeating unit corresponding to a divinyl aromatic compound, and (C) a repeating unit corresponding to a monovinyl polynuclear aromatic compound.

[0026] The repeating unit corresponding to a monovinyl mononuclear aromatic compound (hereinafter also referred to as "monovinyl mononuclear aromatic compound unit") is a structural unit of the copolymer, and is a structural unit having a structure formed by addition polymerization of a monovinyl mononuclear aromatic compound as a monomer. This repeating unit, if having a structure corresponding to the monovinyl mononuclear aromatic compound, is not necessarily limited to one formed by polymerization using the monovinyl mononuclear aromatic compound, but can be one formed by further reacting after polymerization to form a structure corresponding to the monovinyl mononuclear aromatic compound.

[0027] The monovinyl mononuclear aromatic compound is a compound having one vinyl group and one aromatic ring, and is preferably a monovinyl mononuclear aromatic hydrocarbon. As specific examples of the monovinyl mononuclear aromatic compound, styrene, alkylstyrenes (e.g., o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene), dialkylstyrenes (e.g., 3,5-dimethylstyrene, 2,5-dimethylstyrene, 2,5-diethylstyrene), and the like styrene-based compounds can be listed as preferable ones, and any one of these or two or more of these can be used in combination.

[0028] In one embodiment, the monovinyl mononuclear aromatic compound unit preferably contains a repeating unit represented by the following general formula (2). The repeating unit of formula (2) has the following structure in which the vinyl group of the styrene-based compound becomes a single bond by addition polymerization.

[0029] [Chemical Formula 1]

[0030]

[0031] In formula (2), R 3 represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and k represents an integer of 0 to 3. In the case where k is 2 or more, the R 3 may be the same or different. R 3 is preferably an alkyl group having 1 to 3 carbon atoms. k is preferably an integer of 0 to 2.

[0032] In the case of containing the repeating unit represented by the above formula (2), the amount of the repeating unit represented by formula (2) in 100 mol% of the monovinyl mononuclear aromatic compound unit is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more, and can be 100 mol%.

[0033] In one embodiment, the monovinyl mononuclear aromatic compound preferably contains styrene. In this case, the amount of the repeating unit corresponding to styrene (hereinafter also referred to as "styrene unit") in 100 mol% of the monovinyl mononuclear aromatic compound unit is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more, and can be 100 mol%.

[0034] The repeating unit corresponding to the divinyl aromatic compound (hereinafter also referred to as "divinyl aromatic compound unit") described above (B) is a structural unit of the above copolymer, and is a structural unit having one vinyl group formed by addition polymerization of a divinyl aromatic compound as a monomer. This repeating unit, if it is a structure corresponding to a divinyl aromatic compound, is not necessarily limited to one formed by polymerization using the divinyl aromatic compound, and can be one formed by further reacting after polymerization to make a structure corresponding to a divinyl aromatic compound.

[0035] As the divinyl aromatic compound unit, a repeating unit having a structure in which one vinyl group of a divinyl aromatic compound is a single bond by addition polymerization as represented by the following general formula (3) can be exemplified.

[0036] [Chem. 2]

[0037]

[0038] In formula (3), R 4 represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. More specifically, R 4 A divalent aromatic hydrocarbon group having 6 to 30 carbon atoms (more preferably 6 to 20 carbon atoms) selected from the group consisting of a phenylene group which can have a substituent, a biphenyl diyl group which can have a substituent, a naphthylene group which can have a substituent, and a terphenyl diyl group which can have a substituent can be exemplified. Here, the carbon atom number of R 4 in the case where a substituent such as an alkyl group is present, is the number of carbon atoms of R 4 as a whole including the carbon atoms contained in the substituent.

[0039] As the divinyl aromatic compound forming such a repeating unit, it is only necessary to be an aromatic compound having two vinyl groups, and for example, divinylbenzene (including positional isomers or a mixture of these), divinyl naphthalene (including positional isomers or a mixture of these), divinyl biphenyl (including positional isomers or a mixture of these) can be cited, and these can be used as any one or in combination of two or more.

[0040] In one embodiment, the divinyl aromatic compound preferably contains at least one (B1) selected from the group consisting of divinylbenzene, divinyl naphthalene and divinyl biphenyl. In this case, the amount of the repeating unit corresponding to the at least one (B1) in 100 mol% of the divinyl aromatic compound unit is preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, and can be 100 mol%.

[0041] In one embodiment, the divinyl aromatic compound preferably contains divinylbenzene (meta, para or a positional isomer mixture of these). In this case, the amount of the repeating unit corresponding to divinylbenzene (hereinafter, also referred to as "divinylbenzene unit") in 100 mol% of the divinyl aromatic compound unit is preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, and can be 100 mol%.

[0042] The repeating unit corresponding to the monovinyl polycyclic aromatic compound (hereinafter, also referred to as "monovinyl polycyclic aromatic compound unit") of the above-mentioned (C) is a structural unit of the above-mentioned copolymer, and is a structure formed by addition polymerization of the monovinyl polycyclic aromatic compound as a monomer. This repeating unit, if it is a structure corresponding to the monovinyl polycyclic aromatic compound, is not necessarily limited to one formed by polymerization using the monovinyl polycyclic aromatic compound, but can be one formed by further reacting after polymerization to form a structure corresponding to the monovinyl polycyclic aromatic compound.

[0043] The monovinyl polycyclic aromatic compound is a compound having one vinyl group and having a plurality of aromatic rings, and is preferably a monovinyl polycyclic aromatic hydrocarbon. The monovinyl polycyclic aromatic compound can be condensed polycyclic, can be non-condensed polycyclic, or both can be used.

[0044] As the monovinyl condensed polycyclic aromatic compound, for example, vinyl naphthalene (e.g., 1-vinyl naphthalene, 2-vinyl naphthalene), vinyl anthracene (e.g., 1-vinyl anthracene, 2-vinyl anthracene, 9-vinyl anthracene), vinyl phenanthrene (e.g., 9-vinyl phenanthrene, 3-vinyl phenanthrene), vinyl pyrene (e.g., 1-vinyl pyrene, 4-vinyl pyrene), and a nucleus-substituted product thereof (e.g., alkyl vinyl naphthalene and the like nucleus-alkyl-substituted monovinyl condensed polycyclic aromatic compound), and the like can be exemplified, and any one of these or two or more of these in combination can be used.

[0045] As the monovinyl non-condensed polycyclic aromatic compound, for example, vinyl biphenyl (e.g., 4-vinyl biphenyl, 3-vinyl biphenyl), vinyl terphenyl (e.g., 4-vinyl o-terphenyl), and a nucleus-substituted product thereof (e.g., alkyl vinyl biphenyl and the like nucleus-alkyl-substituted monovinyl non-condensed polycyclic aromatic compound), and the like can be exemplified, and any one of these or two or more of these in combination can be used.

[0046] Among these, as the monovinyl polycyclic aromatic compound, a compound in which the number of rings is 3 or less is preferable. Specifically, the monovinyl polycyclic aromatic compound preferably contains at least one (C1) selected from the group consisting of vinyl naphthalene, vinyl anthracene, vinyl phenanthrene, vinyl biphenyl, vinyl terphenyl, and a nucleus-alkyl-substituted product thereof. In this case, the amount of the repeating unit corresponding to the at least one (C1) in 100 mol% of the monovinyl polycyclic aromatic compound unit is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more, and can be 100 mol%.

[0047] In one embodiment, the monovinyl polycyclic aromatic compound preferably contains vinyl naphthalene and / or a nucleus-alkyl-substituted product thereof, and more preferably contains vinyl naphthalene. Specifically, the monovinyl polycyclic aromatic compound unit preferably contains a repeating unit represented by the following general formula (4), and more preferably contains a repeating unit corresponding to vinyl naphthalene (hereinafter, also referred to as "vinyl naphthalene unit"). In this case, the amount of the repeating unit represented by formula (4) (preferably the vinyl naphthalene unit) in 100 mol% of the monovinyl polycyclic aromatic compound unit is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more, and can be 100 mol%.

[0048] [Chemical Formula 3]

[0049]

[0050] In formula (4), R 5 represents a naphthyl group which can have one or more alkyl groups as a substituent, R 5The number of carbon atoms of the monovinyl mononuclear aromatic compound unit is preferably 10 to 20, more preferably 10 to 15, and further preferably 10 to 13.

[0051] The thermosetting resin of the present embodiment is a linear copolymer having the three repeating units described above. The formability is improved by the entanglement of the molecular chains due to the linear structure. Here, the term "linear" means that the repeating units constituting the copolymer have a structure in which the repeating units are connected and bonded to each other in one-dimensional chain form, and means a structure that does not have a crosslinked structure.

[0052] In the thermosetting resin, the monovinyl mononuclear aromatic compound unit, the divinyl aromatic compound unit, and the monovinyl polynuclear aromatic compound unit can be arranged in a regular manner or in a random manner. The thermosetting resin is preferably a random copolymer in which the monovinyl mononuclear aromatic compound unit, the divinyl aromatic compound unit, and the monovinyl polynuclear aromatic compound unit are arranged in a random manner.

[0053] The thermosetting resin can include, in addition to the monovinyl mononuclear aromatic compound unit, the divinyl aromatic compound unit, and the monovinyl polynuclear aromatic compound unit, a repeating unit corresponding to another monomer, within a range that does not impair the effects thereof. As such another monomer, for example, a trivinyl aromatic compound, a trivinyl aliphatic compound, a divinyl aliphatic compound, a monovinyl aliphatic compound, or the like can be exemplified.

[0054] In the thermosetting resin, the content of the monovinyl mononuclear aromatic compound unit is not particularly limited, and when the total repeating units constituting the copolymer are taken as 100 mol%, the content of the monovinyl mononuclear aromatic compound unit in the 100 mol% is preferably 10 mol% to 75 mol%. By being 10 mol% or more, the effect of reducing the melt viscosity is excellent. The content of the monovinyl mononuclear aromatic compound unit is more preferably 15 mol% to 60 mol%, further preferably 20 mol% to 55 mol%, and further preferably 22 mol% to 50 mol%. In the present specification, the 100 mol% of the total repeating units does not include a structure derived from a polymerization initiator present at the terminal of the copolymer.

[0055] In the thermosetting resin, the content of the divinyl aromatic compound unit is not particularly limited, and is preferably 3 mol% to 40 mol% in the 100 mol% of the total repeating units constituting the copolymer. By being 3 mol% or more, the thermosetting can be improved to obtain a good cured product, and the glass transition temperature can be improved. The content of the divinyl aromatic compound unit is more preferably 5 mol% to 30 mol%, further preferably 10 mol% to 25 mol%, and further preferably 12 mol% to 22 mol%.

[0056] The content of the monovinyl polycyclic aromatic compound unit in the thermosetting resin is not particularly limited, and is preferably 20 to 80 mol% in 100 mol% of the total repeating units constituting the copolymer. By being 20 mol% or more, the effects of improving the dielectric properties and the glass transition temperature are excellent. By being 80 mol% or less, the effects of reducing the melt viscosity are excellent. The content of the monovinyl polycyclic aromatic compound unit is more preferably 30 to 70 mol%, further preferably 35 to 65 mol%, and further preferably 35 to 62 mol%.

[0057] The total content of the above-described monovinyl monocyclic aromatic compound unit, the divinyl aromatic compound unit, and the monovinyl polycyclic aromatic compound unit is preferably 80 mol% or more, and more preferably 90 mol% or more, in 100 mol% of the total repeating units constituting the copolymer. It can also be 100 mol%.

[0058] In one embodiment, the thermosetting resin is preferably a copolymer having a repeating unit represented by the above-described formula (2) (preferably a styrene unit), a repeating unit represented by the above-described formula (3) (preferably a divinylbenzene unit), and a repeating unit represented by the above-described formula (4) (preferably a vinyl naphthalene unit). In this case, the thermosetting resin preferably contains each repeating unit as follows when the total repeating units constituting the copolymer are set to 100 mol%. Furthermore, in this case, these repeating units and a repeating unit other than the repeating units of the above-described (A), (B), or (C) can be contained.

[0059] • the repeating unit represented by formula (2) (preferably a styrene unit): 10 to 75 mol%, preferably 15 to 60 mol%, more preferably 20 to 55 mol%, and further preferably 22 to 50 mol%.

[0060] • the repeating unit represented by formula (3) (preferably a divinylbenzene unit): 3 to 40 mol%, preferably 5 to 30 mol%, more preferably 10 to 25 mol%, and further preferably 12 to 22 mol%.

[0061] • the repeating unit represented by formula (4) (preferably a vinyl naphthalene unit): 20 to 80 mol%, preferably 30 to 70 mol%, more preferably 35 to 65 mol%, and further preferably 35 to 62 mol%.

[0062] The thermosetting resin can have at least one of a structure derived from a polymerization initiator represented by the following general formula (1) or a structure derived from a polymerization initiator represented by the following general formula (5) at a terminal of the linear copolymer. The polymerization initiator represented by formula (1) is an azo initiator not having a cyano group, unlike azobisisobutyronitrile (AIBN) which is a general-purpose azo initiator. The polymerization initiator represented by formula (5) is an organic peroxide such as a dialkyl peroxide. By using the polymerization initiator represented by formula (1), more excellent dielectric properties can be imparted.

[0063] R 1 -N=N-R 2 (1)R6-O-O-R7(5)

[0064] In formula (1) and formula (5), R 1 , R 2 , R 6 , and R 7 each independently represent a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group, and do not contain a hetero atom. The number of carbon atoms of the saturated hydrocarbon group is not particularly limited, and is preferably 1 to 23, more preferably 4 to 13. The number of carbon atoms of the aromatic hydrocarbon group is not particularly limited, and is preferably 6 to 23, more preferably 6 to 13.

[0065] As the saturated hydrocarbon group, a branched or linear saturated aliphatic hydrocarbon group (alkyl group) or a saturated alicyclic hydrocarbon group can be used. As specific examples of the saturated hydrocarbon group, a tertiary butyl group, a tertiary amyl group, a tertiary hexyl group, a 1,1,3,3-tetramethylbutyl group, and the like alkyl group, a cyclohexyl group, and the like saturated alicyclic hydrocarbon group can be used.

[0066] As specific examples of the aromatic hydrocarbon group, a phenyl group, a tolyl group, a naphthyl group, and the like aryl group, a cumyl group, a benzyl group, a phenethyl group, and the like aralkyl group can be used.

[0067] In one embodiment, R 1 , R 2 , R 6 , and R 7 may each independently be a group represented by the following general formula (6).

[0068] [Chem. 4]

[0069]

[0070] In formula (6), R 8 , R 9 , and R 10 each independently represent a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group. More preferably, R 8represents a monovalent saturated hydrocarbon group having 1 to 20 carbon atoms (more preferably, a monovalent saturated hydrocarbon group having 1 to 10 carbon atoms) or a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms (more preferably, a monovalent aromatic hydrocarbon group having 6 to 10 carbon atoms), R 9 and R 10 represents a methyl group. As the saturated hydrocarbon group of R 8 , R 9 and R 10 (preferably, R 8 ), branched or straight chain can be mentioned, for example, an alkyl group such as methyl, ethyl, propyl, butyl, heptyl, isopropyl, t-butyl, 2,2-dimethylpropyl and the like, a saturated alicyclic hydrocarbon group such as cyclohexyl and the like can be mentioned. As the aromatic hydrocarbon group of R 8 , R 9 and R 10 (preferably, R 8 ), a phenyl group, a tolyl group, a naphthyl group and the like can be mentioned.

[0071] In the case where these polymerization initiators are used and a vinyl copolymer is synthesized by radical polymerization, generally both terminals of the obtained vinyl copolymer become the structure derived from the polymerization initiator. In the case where polymerization is carried out using the above-described polymerization initiator of formula (1), a copolymer having R 1 - and / or R 2 - at both terminals can be obtained. That is, both terminals of the copolymer can be R 1 -, both can be R 2 -, or one terminal can be R 1 - and the other terminal can be R 2 -. On the other hand, in the case where polymerization is carried out using the above-described polymerization initiator of formula (5), a copolymer having R 6 O- and / or R 7 O- at both terminals can be obtained. That is, both terminals of the copolymer can be R 6 O-, both can be R 7 O-, or one terminal can be R 6 O- and the other terminal can be R 7 O-.

[0072] The weight average molecular weight Mw of the thermosetting resin is not particularly limited, and for example, can be 1 kilo to 100,000, can be 2 kilo to 50,000, or can be 3 kilo to 20,000. By making the weight average molecular weight Mw 1 kilo or more, the concentration of the terminal group derived from the polymerization initiator can be reduced and the dielectric properties can be improved, and the glass transition temperature can be increased. In addition, by making the weight average molecular weight Mw 100,000 or less, the melt viscosity can be reduced. Here, the weight average molecular weight Mw is the polystyrene conversion weight average molecular weight measured by gel permeation chromatography (GPC).

[0073] The production method of the thermosetting resin is not particularly limited. As a method for synthesizing a linear copolymer, in the production method of the preferred embodiment, at least one of the polymerization initiators represented by the above formula (1) or formula (5) is used to copolymerize a vinylbenzyl phosphonium salt, a monovinyl monocyclic aromatic compound, and a monovinyl polycyclic aromatic compound, and the obtained copolymer is reacted with formaldehyde. However, the production method is not limited to this.

[0074] As the vinylbenzyl phosphonium salt, a vinylbenzyl phosphonium halide is preferably used. As the phosphonium group in the vinylbenzyl phosphonium salt, for example, quaternary phosphonium groups such as trialkylphosphonium, triarylphosphonium, and triarylalkylphosphonium can be exemplified. In addition, as the halogen that forms a salt with the phosphonium group, for example, chlorine and bromine can be exemplified.

[0075] As the method for copolymerizing the vinylbenzyl phosphonium salt, the monovinyl monocyclic aromatic compound, and the monovinyl polycyclic aromatic compound, a publicly known vinyl polymerization method can be used. By using the above radical polymerization initiator represented by formula (1) and / or formula (5) as the polymerization initiator, a copolymer having a repeating unit derived from the vinylbenzyl phosphonium salt, a repeating unit derived from the monovinyl monocyclic aromatic compound, and a repeating unit derived from the monovinyl polycyclic aromatic compound can be obtained. At the time of polymerization, a chain transfer agent can be added, and the molecular weight of the copolymer can be adjusted.

[0076] Furthermore, as the method for reacting the obtained copolymer with formaldehyde, a publicly known Wittig reaction can be used, and the copolymer is reacted with formaldehyde by being treated with a base, whereby the phosphonium group is removed and a vinyl group is introduced.

[0077] If this production method is used, in the copolymerization step, the vinylbenzyl phosphonium salt is monovinyl, and thus a linear copolymer having no branch is obtained, and after copolymerization, a vinyl group is introduced into the repeating unit derived from the vinylbenzyl phosphonium salt, and thus a linear copolymer having a repeating unit corresponding to a divinyl aromatic compound and having no branch can be obtained.

[0078] The thermosetting composition of the present embodiment contains the above thermosetting resin. The content of the thermosetting resin in the thermosetting composition is not particularly limited as long as the composition has a property of being cured by heat. For example, it can be 1 to 99 mass% or 10 to 95 mass% with respect to 100 mass% of the solid content of the thermosetting composition (in the case of containing an organic solvent described later, the amount after the removal of the organic solvent, and in the case of not containing an organic solvent, the amount of the entire composition).

[0079] In the thermosetting composition, in addition to the above-mentioned thermosetting resin, for example, other thermosetting resins (thermosetting crosslinking agents), thermoplastic resins, fillers, flame retardants, curing accelerators, polymerization initiators, defoaming agents, heat stabilizers, antistatic agents, ultraviolet absorbers, coloring agents such as dyes or pigments, lubricants, dispersants, and the like can be contained.

[0080] In addition, the thermosetting composition can contain an organic solvent to adjust the viscosity thereof, and the thermosetting composition can be a solution containing the above-mentioned thermosetting resin. As the organic solvent, one that can dissolve the above-mentioned thermosetting resin can be used, and for example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like; esters such as ethyl acetate, propyl acetate, butyl acetate, and the like; amides such as dimethylacetamide, dimethylformamide, and the like; aromatic hydrocarbons such as toluene, xylene, and the like, and the like can be exemplified, and any one of these or two or more of these in combination can be used.

[0081] The thermosetting resin or the thermosetting composition of the present embodiment can be crosslinked by polymerization because it has a vinyl group in the molecular chain of the copolymer, and a cured product can be obtained by thermosetting. Because the dielectric loss tangent and the dielectric constant of the cured product are low and the dielectric properties are excellent, it can be used, for example, for electronic material applications such as printed board materials, semiconductor sealing materials, and the like. That is, the thermosetting composition of one embodiment is an electronic material thermosetting composition.

[0082] As the printed board material, rigid printed board materials such as single-sided boards, double-sided boards, multilayer boards, build-up boards, and the like, or flexible printed board materials in the form of a film or a sheet, and the like can be exemplified. In addition, because the dielectric properties are excellent, it can be preferably used as a high-frequency board material used in high-frequency communication equipment.

[0083] Examples

[0084] Hereinafter, the present application will be described more specifically using examples, but the present application is not limited to the following examples.

[0085] <Measurement and Evaluation Methods>

[0086] [Molar ratio of styrene / divinylbenzene / vinylnaphthalene]

[0087] Regarding the products and compositions obtained in Examples 1 to 9, Examples 11 to 13, Comparative Example 1, Comparative Example 4, Comparative Example 5, and Comparative Example 8, they were dissolved in deuterated chloroform, and1H-NMR was performed using a nuclear magnetic resonance device (manufactured by JEOL). 1The molar ratio of the repeating unit corresponding to styrene, the repeating unit corresponding to divinylbenzene, and the repeating unit corresponding to vinyl naphthalene was determined by H-NMR measurement, and the content of the repeating unit corresponding to styrene (styrene ratio), the content of the repeating unit corresponding to divinylbenzene (divinylbenzene ratio), and the content of the repeating unit corresponding to vinyl naphthalene (vinyl naphthalene ratio) were calculated with respect to 100 mol% of the total repeating units.

[0088] [Styrene / divinylbenzene / vinyl naphthalene / methyl vinyl ether molar ratio]

[0089] The products obtained in Example 10, Comparative Example 2, and Comparative Example 6 were dissolved in deuterated chloroform, and H-NMR measurement was performed using a nuclear magnetic resonance device (manufactured by JEOL). 1 The molar ratio of the repeating unit corresponding to styrene, the repeating unit corresponding to divinylbenzene, the repeating unit corresponding to vinyl naphthalene, and the repeating unit corresponding to vinyl cyclohexane was determined by H-NMR measurement, and the content of the repeating unit corresponding to styrene (styrene ratio), the content of the repeating unit corresponding to divinylbenzene (divinylbenzene ratio), the content of the repeating unit corresponding to vinyl naphthalene (vinyl naphthalene ratio), and the content of the repeating unit corresponding to vinyl cyclohexane (vinyl cyclohexane ratio) were calculated with respect to 100 mol% of the total repeating units.

[0090] [Styrene / divinylbenzene / iso-bornyl acrylate molar ratio]

[0091] The products obtained in Comparative Example 3 and Comparative Example 7 were dissolved in deuterated chloroform, and H-NMR measurement was performed using a nuclear magnetic resonance device (manufactured by JEOL). 1 The molar ratio of the repeating unit corresponding to styrene, the repeating unit corresponding to divinylbenzene, and the repeating unit corresponding to iso-bornyl acrylate was determined by H-NMR measurement, and the content of the repeating unit corresponding to styrene (styrene ratio), the content of the repeating unit corresponding to divinylbenzene (divinylbenzene ratio), and the content of the repeating unit corresponding to iso-bornyl acrylate (iso-bornyl acrylate ratio) were calculated with respect to 100 mol% of the total repeating units.

[0092] [Weight average molecular weight]

[0093] The products and compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 8 were dissolved in tetrahydrofuran, and the gel permeation chromatography (GPC) (Prominence, Shimadzu Corporation) obtained by connecting four columns (Shodex GPC columns KF-601, KF-602, KF-603, KF-604, manufactured by Showa Denko) using polystyrene-based gels as fillers was used to measure the weight average molecular weight Mw in polystyrene conversion. The column oven temperature was set to 40°C, the THF flow rate was 0.6 mL / min, the sample concentration was 0.1 mass%, the sample injection volume was 10 μL, and a differential refractive index detector (Shodex RI-504, manufactured by Showa Denko) was used.

[0094] [Dielectric constant, dielectric loss tangent]

[0095] The products and compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 8 were used as samples. Using a test single-action compression molding machine (manufactured by Yasuda Seiki Mfg. Co., Ltd.), 1.5 g of the sample was pressed at a pressure of 10 MPa and a temperature of 220°C for 15 minutes to produce a flat plate of 30 mm x 30 mm x thickness 1 mm. The obtained flat plate was cut to produce a test piece of width 2 mm, thickness 1 mm, and length 30 mm. For the test piece, a cavity resonator method dielectric constant measuring device (manufactured by KEYSIGHT) was used to measure the dielectric constant and dielectric loss tangent at 10 GHz, and evaluation was performed by the following criteria.

[0096] The dielectric constant was set to "A" (excellent) if it was less than 2.4, to "B" (good) if it was 2.4 or more and less than 2.5, to "C" (ordinary) if it was 2.5 or more and less than 2.6, to "D" (poor) if it was 2.6 or more and less than 2.7, and to "E" (inferior) if it was 2.7 or more.

[0097] The dielectric loss tangent was set to "A" (excellent) if it was less than 0.001, to "B" (good) if it was 0.001 or more and less than 0.002, to "C" (ordinary) if it was 0.002 or more and less than 0.003, to "D" (poor) if it was 0.003 or more and less than 0.004, and to "E" (inferior) if it was 0.004 or more.

[0098] [Glass transition temperature Tg]

[0099] A test piece having a width of 5 mm, a thickness of 1 mm, and a length of 25 mm was produced by cutting the flat plate produced in the above [dielectric constant, dielectric loss tangent]. The glass transition temperature was measured for the test piece using a dynamic viscoelasticity measuring device: Rheogel-E4000 (manufactured by UBE Machinery Corporation). For the test piece, the maximum value of the loss tangent (tan δ) measured under conditions of a tensile sinusoidal wave, a dynamic strain of 5 μm, a frequency of 1 Hz, and a temperature increase rate of 3°C / min was taken as the glass transition temperature. Those having a glass transition temperature of 170°C or higher were rated as "A" (excellent), those having a glass transition temperature of 160°C or higher and less than 170°C were rated as "B" (good), those having a glass transition temperature of 150°C or higher and less than 160°C were rated as "C" (fair), and those having a glass transition temperature of less than 150°C were rated as "D" (poor).

[0100] [Melting viscosity (lowest melting viscosity)]

[0101] The products and compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 8 were used as samples. Using a manual hydraulic pump: P-1B (manufactured by Riken), 0.4 g of the sample was pressed for 1 minute at a pressure of 10 MPa to produce a pellet having a diameter of 20 mm x a thickness of 1 mm. The obtained pellet was used as a sample, and a rheometer: MCR 302 (manufactured by Anton Paar) was used to increase the temperature from 50°C to 200°C at a temperature increase rate of 5°C / min. The minimum value of the complex viscosity was taken as the lowest melting viscosity, and those having a lowest melting viscosity of less than 50000 poise were rated as "O" (low viscosity), and those having a lowest melting viscosity of 50000 poise or higher were rated as "X" (high viscosity).

[0102] (Synthetic Example 1) Synthesis of Compound 1: Vinylbenzyltriphenylphosphonium chloride

[0103] Vinylbenzyl chloride (trade name: CMS-14, manufactured by AGC Seimi Chemical Co., Ltd.) 1.5 moles (228.9 g), triphenylphosphine 1.8 moles (472.1 g), and dimethylformamide 622.4 g were charged into a 2.0 L reactor, and reacted at 70°C for 3 hours under a nitrogen atmosphere, whereby white solid was precipitated. The solid was sufficiently washed with acetone, and then dried under reduced pressure at 92°C, whereby 490 g of Compound 1 was recovered.

[0104] (Synthetic Example 2) Synthesis of Copolymer A

[0105] Styrene 11.1 g, 12.4 g of compound 1, 2-vinylnaphthalene 12.0 g, 2,4-diphenyl-4-methyl-l-pentene 3.7 g as a chain transfer agent, 2,2'-azobis(2,4,4-trimethylpentane) (trade name: VR-110, FUJIFILM Wako Pure Chemical Corporation) 1.35 g as a polymerization initiator, and dimethylformamide 82.7 g were charged into a 500 mL reactor, and a reaction was performed at 120°C for 3 hours under a nitrogen atmosphere, whereby a copolymer A was obtained as a dimethylformamide solution.

[0106] (Synthesis Example 3) Synthesis of Copolymer B

[0107] Styrene 8.2 g, 13.8 g of compound 1, 2-vinylnaphthalene 10.0 g, 2,4-diphenyl-4-methyl-l-pentene 3.3 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.21 g, and dimethylformamide 74.6 g were charged into a 500 mL reactor, and a reaction was performed at 120°C for 3 hours under a nitrogen atmosphere, whereby a copolymer B was obtained as a dimethylformamide solution.

[0108] (Synthesis Example 4) Synthesis of Copolymer C

[0109] Styrene 13.3 g, 8.9 g of compound 1, 2-vinylnaphthalene 13.0 g, 2,4-diphenyl-4-methyl-l-pentene 3.7 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.34 g, and dimethylformamide 82.3 g were charged into a 500 mL reactor, and a reaction was performed at 120°C for 3 hours under a nitrogen atmosphere, whereby a copolymer C was obtained as a dimethylformamide solution.

[0110] (Synthesis Example 5) Synthesis of Copolymer D

[0111] Styrene 13.5 g, 12.4 g of compound 1, 2-vinylnaphthalene 9.0 g, 2,4-diphenyl-4-methyl-l-pentene 3.6 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.33 g, and dimethylformamide 81.4 g were charged into a 500 mL reactor, and a reaction was performed at 120°C for 3 hours under a nitrogen atmosphere, whereby a copolymer D was obtained as a dimethylformamide solution.

[0112] (Synthesis Example 6) Synthesis of Copolymer E

[0113] Styrene 5.8 g, 11.7 g of Compound 1, 2-vinylnaphthalene 17.0 g, 2,4-diphenyl-4- methyl-1-pentene 3.6 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.31 g, and dimethylformamide 80.5 g were charged into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen to obtain a copolymer E as a dimethylformamide solution.

[0114] (Synthetic Example 7) Synthesis of Copolymer F

[0115] Styrene 11.9 g, 8.9 g of Compound 1, 2-vinylnaphthalene 14.5 g, 2,4-diphenyl-4- methyl-1-pentene 3.7 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.34 g, and dimethylformamide 82.2 g were charged into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen to obtain a copolymer F as a dimethylformamide solution.

[0116] (Synthetic Example 8) Synthesis of Copolymer G

[0117] Styrene 9.5 g, 14.2 g of Compound 1, 2-vinylnaphthalene 9.0 g, 2,4-diphenyl-4- methyl-1-pentene 3.4 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.24 g, and dimethylformamide 76.1 g were charged into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen to obtain a copolymer G as a dimethylformamide solution.

[0118] (Synthetic Example 9) Synthesis of Copolymer H

[0119] Styrene 4.1 g, 13.8 g of Compound 1, 2-vinylnaphthalene 15.0 g, 2,4-diphenyl-4- methyl-1-pentene 3.4 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.25 g, and dimethylformamide 76.7 g were charged into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen to obtain a copolymer H as a dimethylformamide solution.

[0120] (Synthetic Example 10) Synthesis of Copolymer I

[0121] Styrene 16.4 g, 9.2 g of Compound 1, 2-vinylnaphthalene 10.0 g, 2,4-diphenyl-4- methyl-1-pentene 3.7 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.35 g, and dimethylformamide 83.0 g were charged into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen to obtain a copolymer I as a dimethylformamide solution.

[0122] (Synthetic Example 11) Synthesis of Copolymer J

[0123] Styrene 5.6 g, 11.4 g of Compound 1, 2-vinylnaphthalene 5.0 g, vinylcyclohexane 7.2 g, 2,4-diphenyl-4-methyl-l-pentene 3.7 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.34 g, and dimethylformamide 82.0 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, to thereby obtain Copolymer J as a dimethylformamide solution.

[0124] (Synthetic Example 12) Synthesis of Copolymer K

[0125] Styrene 10.1 g, 11.4 g of Compound 1, 2-vinylnaphthalene 11.0 g, 2,4-diphenyl-4-methyl-l-pentene 3.4 g, di-t-butyl peroxide (trade name: Perbutyl D, manufactured by Nippon Oil) as a polymerization initiator 0.71 g, and dimethylformamide 75.8 g were put into a 500 mL reactor, and reacted at 132°C for 3 hours under a nitrogen atmosphere, to thereby obtain Copolymer K as a dimethylformamide solution.

[0126] (Synthetic Example 13) Synthesis of Copolymer L

[0127] Styrene 11.1 g, 12.4 g of Compound 1, 2-vinylnaphthalene 12.0 g, 2,4-diphenyl-4-methyl-l-pentene 2.5 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.35 g, and dimethylformamide 82.7 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under a nitrogen atmosphere, to thereby obtain Copolymer L as a dimethylformamide solution.

[0128] (Synthetic Example 14) Synthesis of Copolymer M

[0129] Styrene 10.1 g, 11.4 g of Compound 1, 2-vinylnaphthalene 11.0 g, 2,4-diphenyl-4-methyl-l-pentene 6.8 g, 2,2'-azobis(2,4,4-trimethylpentane) 2.47 g, and dimethylformamide 75.8 g were put into a 500 mL reactor, and reacted at 120°C for 1.5 hours under a nitrogen atmosphere, to thereby obtain Copolymer M as a dimethylformamide solution.

[0130] (Comparative Synthetic Example 1) Synthesis of Copolymer N

[0131] Styrene 22.0 g, 15.5 g of Compound 1, 2, 4-diphenyl-4-methyl-l-pentene 3.9 g, di-t-butyl peroxide 0.82 g, and dimethylformamide 87.4 g were charged into a 500 mL reactor, and reacted at 132°C for 3 hours under nitrogen to obtain a copolymer N as a dimethylformamide solution.

[0132] (Synthetic Example 2) Synthesis of Copolymer O

[0133] Styrene 9.9 g, 11.1 g of Compound 1, vinylcyclohexane 14.0 g, 2, 4-diphenyl-4-methyl-l-pentene 3.7 g, di-t-butyl peroxide 0.53 g, and dimethylformamide 81.4 g were charged into a 500 mL reactor, and reacted at 132°C for 3 hours under nitrogen to obtain a copolymer O as a dimethylformamide solution.

[0134] (Synthetic Example 3) Synthesis of Copolymer P

[0135] Styrene 9.2 g, 10.7 g of Compound 1, isobornyl acrylate 15.0 g, 2, 4-diphenyl-4-methyl-l-pentene 3.7 g, di-t-butyl peroxide 0.77 g, and dimethylformamide 81.4 g were charged into a 500 mL reactor, and reacted at 132°C for 3 hours under nitrogen to obtain a copolymer P as a dimethylformamide solution.

[0136] (Synthetic Example 4) Synthesis of Copolymer Q

[0137] Compound 1 10.7 g, 2-vinylnaphthalene 22.0 g, 2, 4-diphenyl-4-methyl-l-pentene 3.4 g, 2, 2'-azobis(2, 4, 4-trimethylpentane) 1.24 g, and dimethylformamide 76.3 g were charged into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen to obtain a copolymer Q as a dimethylformamide solution.

[0138] (Synthetic Example 5) Synthesis of Copolymer R

[0139] Styrene 9.9 g, 11.1 g of Compound 1, vinylcyclohexane 14.0 g, 2, 4-diphenyl-4-methyl-l-pentene 3.6 g, 2, 2'-azobis(2, 4, 4-trimethylpentane) 1.33 g, and dimethylformamide 81.7 g were charged into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen to obtain a copolymer R as a dimethylformamide solution.

[0140] (Synthetic Example 6) Synthesis of Copolymer S

[0141] Styrene 9.2 g, 10.7 g of Compound 1, isobornyl acrylate 15.0 g, 2,4-diphenyl-4- methyl-1-pentene 3.6 g, 2,2'-azobis(2,4,4-trimethylpentane) 1.33 g, and dimethylformamide 81.4 g were put into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen to obtain a copolymer S as a dimethylformamide solution.

[0142] (Synthetic Example 7) Synthesis of Copolymer T

[0143] Styrene 17.0 g, 16.9 g of Compound 1, 2,4-diphenyl-4-methyl-1-pentene 3.5 g, 2,2'- azobis(2,4,4-trimethylpentane) 1.29 g, and dimethylformamide 79.2 g were put into a 500 mL reactor, and reacted at 120°C for 2 hours under nitrogen to obtain a dimethylformamide solution. The dimethylformamide solution 117.9 g, toluene 117.9 g, 37 mass% formalin 32.9 g, and 28 mass% potassium hydroxide aqueous solution 40.6 g were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 23.3 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 13.0 g of copolymer T was recovered. The Mw of the copolymer T was 6400, the styrene ratio was 79.5 mol%, and the divinylbenzene ratio was 20.5 mol%.

[0144] (Synthetic Example 8) Synthesis of Polymer U

[0145] 2-Vinylnaphthalene 35.0 g, 2,4-diphenyl-4-methyl-1-pentene 3.6 g, 2,2'-azobis(2,4,4- trimethylpentane) 1.33 g, and dimethylformamide 81.7 g were put into a 500 mL reactor, and reacted at 120°C for 4 hours under nitrogen. The reaction solution was reprecipitated in a large excess of methanol, and then the supernatant was decanted. The residual solid was dried under reduced pressure at 92°C, whereby 33.2 g of polymer U was recovered.

[0146] (Example 1)

[0147] A dimethylformamide solution 123.2 g of the copolymer A obtained in Synthesis Example 2, toluene 123.2 g, 37 mass% formalin 29.1 g, and a 28 mass% potassium hydroxide aqueous solution 35.9 g were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 17.0 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, after the solid was taken out by filtration, it was dried under reduced pressure at 60°C, whereby 15.6 g of the product 1 was recovered. The product 1 had a Mw of 7200, a styrene ratio of 43.7 mol%, a divinylbenzene ratio of 15.7 mol%, and a 2-vinylnaphthalene ratio of 40.6 mol%.

[0148] (Example 2)

[0149] A dimethylformamide solution 111.0 g of the copolymer B obtained in Synthesis Example 3, toluene 111.0 g, 37 mass% formalin 32.3 g, and a 28 mass% potassium hydroxide aqueous solution 39.9 g were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 18.9 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, after the solid was taken out by filtration, it was dried under reduced pressure at 60°C, whereby 13.1 g of the product 2 was recovered. The product 2 had a Mw of 7100, a styrene ratio of 38.9 mol%, a divinylbenzene ratio of 20.8 mol%, and a 2-vinylnaphthalene ratio of 40.3 mol%.

[0150] (Example 3)

[0151] A dimethylformamide solution of the copolymer C obtained in Synthesis Example 4, 122.5 g, toluene, 122.5 g, 37 mass% formalin, 21.0 g, and 28 mass% potassium hydroxide aqueous solution, 25.9 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 12.3 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, after the solid was taken out by filtration, it was dried under reduced pressure at 60°C, whereby 17.2 g of product 3 was recovered. The Mw of the product 3 was 7500, the styrene ratio was 48.1 mol%, the divinylbenzene ratio was 11.0 mol%, and the 2-vinylnaphthalene ratio was 40.9 mol%.

[0152] (Example 4)

[0153] A dimethylformamide solution of the copolymer D obtained in Synthesis Example 5, 121.3 g, toluene, 121.3 g, 37 mass% formalin, 29.1 g, and 28 mass% potassium hydroxide aqueous solution, 35.9 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 17.0 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, after the solid was taken out by filtration, it was dried under reduced pressure at 60°C, whereby 15.5 g of product 4 was recovered. The Mw of the product 4 was 7000, the styrene ratio was 54.2 mol%, the divinylbenzene ratio was 15.5 mol%, and the 2-vinylnaphthalene ratio was 30.3 mol%.

[0154] (Example 5)

[0155] A dimethylformamide solution of the copolymer E obtained in Synthesis Example 6, 119.9 g, toluene, 119.9 g, 37 mass% formalin, 27.4 g, and a 28 mass% potassium hydroxide aqueous solution, 33.9 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 16.1 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, after the solid was taken out by filtration, it was dried under reduced pressure at 60°C, whereby 15.4 g of product 5 was recovered. The Mw of the product 5 was 7300, the styrene ratio was 22.7 mol%, the divinylbenzene ratio was 15.8 mol%, and the 2-vinylnaphthalene ratio was 61.5 mol%.

[0156] (Example 6)

[0157] A dimethylformamide solution of the copolymer F obtained in Synthesis Example 7, 122.5 g, toluene, 122.5 g, 37 mass% formalin, 20.8 g, and a 28 mass% potassium hydroxide aqueous solution, 25.7 g, were put into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 12.2 g of anhydrous magnesium chloride was put in, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, after the solid was taken out by filtration, it was dried under reduced pressure at 60°C, whereby 17.1 g of product 6 was recovered. The Mw of the product 6 was 7400, the styrene ratio was 44.6 mol%, the divinylbenzene ratio was 10.1 mol%, and the 2-vinylnaphthalene ratio was 45.3 mol%.

[0158] (Example 7)

[0159] A dimethylformamide solution of the copolymer G obtained in Synthesis Example 8, 113.4 g, toluene, 113.4 g, 37 mass% formalin, 33.2 g, and 28 mass% potassium hydroxide aqueous solution, 41.0 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 19.5 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 13.2 g of the product 7 was recovered. The product 7 had a Mw of 6800, a styrene ratio of 44.5 mol%, a divinylbenzene ratio of 20.0 mol%, and a 2-vinylnaphthalene ratio of 35.5 mol%.

[0160] (Example 8)

[0161] A dimethylformamide solution of the copolymer H obtained in Synthesis Example 9, 114.2 g, toluene, 114.2 g, 37 mass% formalin, 32.3 g, and 28 mass% potassium hydroxide aqueous solution, 39.9 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 18.9 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 13.6 g of the product 8 was recovered. The product 8 had a Mw of 7200, a styrene ratio of 18.7 mol%, a divinylbenzene ratio of 20.3 mol%, and a 2-vinylnaphthalene ratio of 61.0 mol%.

[0162] (Example 9)

[0163] A dimethylformamide solution of the copolymer I obtained in Synthesis Example 10, 123.6 g, toluene, 123.6 g, 37 mass% formalin, 21.5 g, and 28 mass% potassium hydroxide aqueous solution, 26.6 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 12.6 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and subjected to reduced-pressure drying at 60°C, whereby 17.0 g of Product 9 was recovered. The Mw of Product 9 was 7400, the styrene ratio was 58.7 mol%, the divinylbenzene ratio was 10.7 mol%, and the 2-vinylnaphthalene ratio was 30.6 mol%.

[0164] (Example 10)

[0165] A dimethylformamide solution of the copolymer J obtained in Synthesis Example 11, 122.1 g, toluene, 122.1 g, 37 mass% formalin, 26.6 g, and 28 mass% potassium hydroxide aqueous solution, 32.9 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 15.6 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and subjected to reduced-pressure drying at 60°C, whereby 11.5 g of Product 10 was recovered. The Mw of Product 10 was 7600, the styrene ratio was 25.0 mol%, the divinylbenzene ratio was 16.1 mol%, the 2-vinylnaphthalene ratio was 40.8 mol%, and the vinylcyclohexane ratio was 18.1 mol%.

[0166] (Example 11)

[0167] A dimethylformamide solution 114.9 g of the copolymer K obtained in Synthesis Example 12, toluene 114.9 g, 37 mass% formalin 26.6 g, and 28 mass% potassium hydroxide aqueous solution 32.9 g were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 15.6 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 14.5 g of the product 11 was recovered. The Mw of the product 11 was 7000, the styrene ratio was 44.1 mol%, the divinylbenzene ratio was 15.5 mol%, and the 2-vinylnaphthalene ratio was 40.4 mol%.

[0168] (Example 12)

[0169] A dimethylformamide solution 122.0 g of the copolymer L obtained in Synthesis Example 13, toluene 122.0 g, 37 mass% formalin 29.1 g, and 28 mass% potassium hydroxide aqueous solution 35.9 g were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 17.0 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after the solid matter was removed by filtration and diluted with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 15.5 g of the product 12 was recovered. The Mw of the product 12 was 9900, the styrene ratio was 43.2 mol%, the divinylbenzene ratio was 16.0 mol%, and the 2-vinylnaphthalene ratio was 40.8 mol%.

[0170] (Example 13)

[0171] A dimethylformamide solution of the copolymer M obtained in Synthesis Example 14, 117.5 g, toluene, 117.5 g, 37 mass% formalin, 26.6 g, and 28 mass% potassium hydroxide aqueous solution, 32.9 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 15.6 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 14.0 g of product 13 was recovered. The Mw of the product 13 was 2800, the styrene ratio was 44.4 mol%, the divinylbenzene ratio was 15.4 mol%, and the 2-vinylnaphthalene ratio was 40.2 mol%.

[0172] (Comparative Example 1)

[0173] A dimethylformamide solution of the copolymer N obtained in Comparative Synthesis Example 1, 129.7 g, toluene, 129.7 g, 37 mass% formalin, 36.2 g, and 28 mass% potassium hydroxide aqueous solution, 44.7 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 21.3 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was taken out by filtration, and dried under reduced pressure at 60°C, whereby 15.6 g of product 14 was recovered. The Mw of the product 14 was 5600, the styrene ratio was 83.2 mol%, the divinylbenzene ratio was 16.8 mol%.

[0174] (Comparative Example 2)

[0175] A dimethylformamide solution of the copolymer O obtained in Comparative Synthesis Example 2, 121.0 g, toluene, 121.0 g, 37 mass% formalin, 26.1 g, and 28 mass% potassium hydroxide aqueous solution, 32.2 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 15.3 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was removed by filtration, and dried under reduced pressure at 60°C, whereby 15.8 g of product 15 was recovered. The Mw of the product 15 was 7100, the styrene ratio was 45.2 mol%, the divinylbenzene ratio was 16.4 mol%, and the vinylcyclohexane ratio was 38.4 mol%.

[0176] (Comparative Example 3)

[0177] A dimethylformamide solution of the copolymer P obtained in Comparative Synthesis Example 3, 120.7 g, toluene, 120.7 g, 37 mass% formalin, 25.2 g, and 28 mass% potassium hydroxide aqueous solution, 31.1 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 14.8 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, the solid was removed by filtration, and dried under reduced pressure at 60°C, whereby 16.0 g of product 16 was recovered. The Mw of the product 16 was 7000, the styrene ratio was 43.4 mol%, the divinylbenzene ratio was 15.6 mol%, and the isobornyl acrylate ratio was 41.0 mol%.

[0178] (Comparative Example 4)

[0179] Styrene, 49.2 g, vinyl naphthalene, 20.0 g, 2,4-diphenyl-4-methyl-1-pentene, 9.3 g, 2,2'-azobis(2,4,4-trimethylpentane), 3.39 g, and dimethylformamide, 208.1 g, were charged into a 500 mL reactor, and reacted at 120°C for 3 hours under nitrogen. The reaction solution was reprecipitated in a large excess of methanol, and then the supernatant was decanted. The residual solid was dried under reduced pressure at 80°C, whereby 51.9 g of product 17 was recovered. The Mw of the product 17 was 6500, the styrene ratio was 58.9 mol%, and the 2-vinyl naphthalene ratio was 41.1 mol%.

[0180] (Comparative Example 5)

[0181] A dimethylformamide solution of the copolymer Q obtained in Comparative Synthesis Example 4, 113.6 g, toluene, 113.6 g, 37 mass% formalin, 25.1 g, and a 28 mass% potassium hydroxide aqueous solution, 31.0 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 14.7 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, after the solid was removed by filtration, it was dried under reduced pressure at 60°C, whereby 14.9 g of product 18 was recovered. The Mw of the product 18 was 7500, the divinylbenzene ratio was 15.2 mol%, and the 2-vinylnaphthalene ratio was 84.8 mol%.

[0182] (Comparative Example 6)

[0183] A dimethylformamide solution of the copolymer R obtained in Comparative Synthesis Example 5, 121.7 g, toluene, 121.7 g, 37 mass% formalin, 26.1 g, and a 28 mass% potassium hydroxide aqueous solution, 32.2 g, were charged into a 500 mL reactor, and reacted at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 15.3 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Next, after the solid was removed by filtration, it was dried under reduced pressure at 60°C, whereby 15.8 g of product 19 was recovered. The Mw of the product 19 was 7200, the styrene ratio was 46.4 mol%, the divinylbenzene ratio was 16.6 mol%, and the vinylcyclohexane ratio was 37.0 mol%.

[0184] (Comparative Example 7)

[0185] A dimethylformamide solution of the copolymer S obtained in Comparative Synthesis Example 6, 121.2 g, toluene, 121.2 g, 37 mass% formalin, 25.2 g, and a 28 mass% potassium hydroxide aqueous solution, 31.1 g, were charged into a 500 mL reactor, and allowed to react at room temperature for 4 hours. The reaction solution was diluted with toluene, and the organic layer was washed with distilled water and isopropyl alcohol. After the organic layer was dehydrated and concentrated, 14.8 g of anhydrous magnesium chloride was charged, and stirred at 65°C for 2 hours. The filtrate after removal of solid matter by filtration and dilution with toluene was reprecipitated in methanol. Subsequently, the solid was removed by filtration, and dried under reduced pressure at 60°C, whereby 16.0 g of product 20 was recovered. The Mw of the product 20 was 7300, the styrene ratio was 44.5 mol%, the divinylbenzene ratio was 15.3 mol%, and the isobornyl acrylate ratio was 40.2 mol%.

[0186] (Comparative Example 8)

[0187] A copolymer T obtained in Comparative Synthesis Example 7, 4.3 g, and a polymer U obtained in Comparative Synthesis Example 8, 4.0 g, were mixed, and dissolved in toluene to make a uniform solution. The solution was dried under reduced pressure at 60°C, whereby 8.0 g of composition 1 was recovered. The Mw of the composition 1 was 7700, the styrene ratio was 47.7 mol%, the divinylbenzene ratio was 12.3 mol%, and the 2-vinylnaphthalene ratio was 40.0 mol%.

[0188] The dielectric constant, dielectric loss tangent, glass transition temperature, and melt viscosity were evaluated for the products and compositions obtained in Examples 1 to 13 and Comparative Examples 1 to 8. The results are shown in Tables 1 to 5 below.

[0189] [Table 1]

[0190] Example 1 Example 2 Example 3 Example 4 Example 5 Styrene ratio (mol%) 43.7 38.9 48.1 54.2 22.7 Divinylbenzene ratio (mol%) 15.7 20.8 11.0 15.5 15.8 Vinyl naphthalene ratio (mol%) 40.6 40.3 40.9 30.3 61.5 Weight average molecular weight Mw 7200 7100 7500 7000 7300 Dielectric constant (10 GHz) A B A B A Dielectric loss tangent (10 GHz) A A A A A Glass transition temperature B A C B A Melt viscosity ○ ○ ○ ○ ○

[0191] [Table 2]

[0192] Example 6 Example 7 Example 8 Example 9 Example 10 Styrene ratio (mol%) 44.6 44.5 18.7 58.7 25.0 Divinylbenzene ratio (mol%) 10.1 20.0 20.3 10.7 16.1 Vinyl naphthalene ratio (mol%) 45.3 35.5 61.0 30.6 40.8 Vinyl cyclohexane ratio (mol%) - - - - 18.1 Weight average molecular weight Mw 7400 6800 7200 7400 7600 Dielectric constant (10 GHz) A B A A B Dielectric loss tangent (10 GHz) A A A A A Glass transition temperature C A A C B Melt viscosity ○ ○ ○ ○ ○

[0193] [Table 3]

[0194] Example 11 Example 12 Example 13 Styrene ratio (mol%) 44.1 43.2 44.4 Divinylbenzene ratio (mol%) 15.5 16.0 15.4 Vinyl naphthalene ratio (mol%) 40.4 40.8 40.2 Weight average molecular weight Mw 7000 9900 2800 Dielectric constant (10 GHz) C A A Dielectric loss tangent (10 GHz) C A A Glass transition temperature B A C Melt viscosity ○ ○ ○

[0195] [Table 4]

[0196] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Styrene ratio (mol%) 83.2 45.2 43.4 58.9 - Divinylbenzene ratio (mol%) 16.8 16.4 15.6 - 15.2 Vinyl naphthalene ratio (mol%) - - - 41.1 84.8 Vinyl cyclohexane ratio (mol%) - 38.4 - - - Isobornyl acrylate ratio (mol%) - - 41.0 - - Weight average molecular weight Mw 5600 7100 7000 6500 7500 Dielectric constant (10 GHz) D D E - A Dielectric loss tangent (10 GHz) D D E - A Glass transition temperature C D A - A Melt viscosity ○ ○ ○ - ×

[0197] [Table 5]

[0198] Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) 46.4 44.5 47.7 Divinylbenzene ratio (mol%) 16.6 15.3 12.3 Vinyl naphthalene ratio (mol%) - - 40.0 Vinyl cyclohexane ratio (mol%) 37.0 - - Isobornyl acrylate ratio (mol%) - 40.2 - Weight average molecular weight Mw 7200 7300 7700 Dielectric constant (10 GHz) B D A Dielectric loss tangent (10 GHz) A D A Glass transition temperature D A D Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric constant (10 GHz) Dielectric loss tangent (10 GHz) Glass transition temperature Melt viscosity Comparative Example 6 Comparative Example 7 Comparative Example 8 Styrene ratio (mol%) Divinylbenzene ratio (mol%) Vinyl naphthalene ratio (mol%) Vinyl cyclohexane ratio (mol%) Isobornyl acrylate ratio (mol%) Weight average molecular weight Mw Dielectric ○ ○ ×

[0199] Example 11 and Comparative Examples 1 to 3 are examples using a peroxide type polymerization initiator. Since there are no vinyl naphthalene units in Comparative Example 1, the dielectric constant and dielectric loss tangent are poor. In Comparative Example 2, vinyl cyclohexane is added as a monomer to be copolymerized in addition to Comparative Example 1, but the dielectric constant and dielectric loss tangent are not improved, and the glass transition temperature decreases. In Comparative Example 3, isobornyl acrylate is added as a monomer to be copolymerized in addition to Comparative Example 1, and the glass transition temperature is improved, but the dielectric constant and dielectric loss tangent are both deteriorated due to the presence of an ester group.

[0200] In contrast, in Example 11, the dielectric constant and dielectric loss tangent are improved, and the glass transition temperature is increased by incorporating vinyl naphthalene units in addition to Comparative Example 1, so that both the dielectric properties and the glass transition temperature can be taken into account. In Example 11, the lowest melt viscosity is also low.

[0201] Examples 1 to 10, Examples 12 to 13, and Comparative Examples 4 to 8 are examples using the above-described azo initiator of formula (1). In Comparative Example 4, there are no divinylbenzene units, and no thermal curing is performed. Therefore, test pieces for dielectric constant, dielectric loss tangent, and glass transition temperature evaluation cannot be produced, and evaluation of these items cannot be performed. In addition, since no thermal curing is performed, the melt viscosity monotonously decreases, so that the lowest melt viscosity cannot be observed.

[0202] In Comparative Example 5, the dielectric properties and the glass transition temperature are excellent, but the lowest melt viscosity is high and the processability is poor since there are no styrene units. In Comparative Example 6 in which styrene, divinylbenzene, and vinyl cyclohexane are copolymerized, the dielectric constant and dielectric loss tangent are improved in comparison with Comparative Example 2 due to the difference in polymerization initiator, but the glass transition temperature is poor since no vinyl naphthalene units are included. In Comparative Example 7 in which styrene and divinylbenzene and isobornyl acrylate are copolymerized, the glass transition temperature is excellent, but the dielectric constant and dielectric loss tangent are poor due to the presence of an ester group.

[0203] In Comparative Example 8, copolymer T and polymer U are mixed, and the composition includes styrene units, divinylbenzene units, and vinyl naphthalene units, but the glass transition temperature is poor, and the lowest melt viscosity is high and the processability is poor.

[0204] On the other hand, in the case of Examples 1 to 10 and Examples 12 to 13, by copolymerizing styrene, divinylbenzene and vinyl naphthalene, the dielectric constant and the dielectric loss tangent are excellent, and the glass transition temperature is maintained or increased relative to Comparative Example 1, so that the dielectric properties and the glass transition temperature can be balanced. In addition, the minimum melt viscosity is also low. In addition, in the case of Examples 1 to 10 and Examples 12 to 13, the dielectric constant and the dielectric loss tangent are excellent relative to Example 11 due to the difference in the polymerization initiator.

[0205] In addition, in the products of Examples 1 to 13, even without using a thermoplastic resin or a crosslinking agent, a sheet sufficient to be self-supporting can be formed, and the formability is excellent.

[0206] Further, with respect to the various numerical ranges described in the specification, the upper limit value and the lower limit value of each of these can be arbitrarily combined, and all of these combinations are described in the specification as preferred numerical ranges. In addition, the description of the numerical range of "X to Y" means X or more and Y or less.

[0207] The above describes several embodiments of the present application, but these embodiments are presented as examples and are not intended to limit the scope of the application. These embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made within the scope of the gist of the application. These embodiments or omissions, substitutions, and modifications, etc. are included in the scope or gist of the application, and are included in the scope of the application described in the claims and the equivalent thereof.

Claims

1. A thermosetting resin characterized by comprising: the thermosetting resin is a linear copolymer and has a repeating unit corresponding to a monovinyl mononuclear aromatic compound, a repeating unit corresponding to a divinyl aromatic compound, and a repeating unit corresponding to a monovinyl polynuclear aromatic compound.

2. The thermosetting resin according to claim 1, wherein: the content of the repeating unit corresponding to the monovinyl polynuclear aromatic compound is 20 to 80 mol% in 100 mol% of the total repeating units.

3. The thermosetting resin according to claim 1, wherein: at the terminal of the straight-chain copolymer, R 1 -N=N-R 2 represents the structure of a polymerization initiator, R 1 and R 2 each independently represents a monovalent saturated hydrocarbon group or a monovalent aromatic hydrocarbon group.

4. The thermosetting resin according to claim 1, wherein: the total content of the repeating unit corresponding to the monovinyl mononuclear aromatic compound, the repeating unit corresponding to the divinyl aromatic compound, and the repeating unit corresponding to the monovinyl polynuclear aromatic compound is 80 mol% or more in 100 mol% of the total repeating units.

5. The thermosetting resin according to claim 1, wherein: the number of rings of the monovinyl polynuclear aromatic compound is 3 or less.

6. A cured product characterized by being obtained by curing the thermosetting resin according to any one of claims 1 to 5.

7. A thermosetting composition characterized by comprising: the thermosetting resin according to any one of claims 1 to 5.

8. The thermosetting composition according to claim 7, wherein: the thermosetting composition is a printed board material. ​

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