Copolymer composition and cured product

Abstract

Provided is a copolymer composition of which cured product exhibits excellent dielectric characteristics. This α-olefin-aromatic vinyl-cyclic olefin-aromatic polyene copolymer composition has glass transition temperatures within ranges of, at least, -30 to 35°C and 150 to 250°C, and a molded product obtained by curing the composition exhibits a dielectric constant measured at 25°C and 40 GHz of 2.0 or more and less than 2.5, a dielectric loss tangent of 0.0001 to 0.0010 inclusive, a storage elastic modulus at 25°C of 0.5 GPa or more, and a storage elastic modulus at 280°C of 2 MPa or more.

Description

Copolymer composition and cured product

[0001] The present invention relates to a copolymer composition and a cured product thereof.

[0002] As communication frequencies move into the gigahertz range and higher, there is a growing need for multilayer substrates made of insulating materials with low dielectric properties, such as copper clad laminates (CCLs), flexible copper clad laminates (FCCLs), and resin-coated copper (RCCs). While fluororesins such as perfluoroethylene possess excellent low dielectric constants, low dielectric loss, and heat resistance, they suffer from difficulties in moldability and film formability, as well as issues with adhesion to copper foil for wiring, making them difficult to apply to multilayer substrates. Meanwhile, substrates and insulating materials made from post-cured resins such as epoxy resins, unsaturated polyester resins, polyimide resins, and phenolic resins have been widely used due to their heat resistance and ease of handling, but their relatively high dielectric constants and dielectric loss leave room for improvement as insulating materials for high frequencies (see Patent Document 1).

[0003] Therefore, hydrocarbon-based resins with inherently low dielectric properties have attracted attention. Cyclic olefin (co)polymers with particularly high glass transition temperatures (Tg) have been proposed as thermoplastic insulating materials. However, because their glass transition temperatures are close to the solder reflow temperature, crosslinkable (curable) resins are preferable in terms of process compatibility and process window. Converting hydrocarbon-based resins, which are essentially thermoplastic resins, into curable resins requires the introduction of crosslinkable functional groups. However, functional groups that react to radicals or heat generally contain oxygen or nitrogen atoms, making them polar, thereby degrading their low dielectric properties. Patent Document 2 discloses a cured product obtained from a specific coordination polymerization catalyst and consisting of an ethylene-olefin (aromatic vinyl compound)-aromatic polyene copolymer with a specific composition and blend, and a non-polar vinyl compound. This technology selectively copolymerizes only one of the two vinyl groups of the aromatic polyene (divinylbenzene), preserving the remaining vinyl group, making it easy to obtain a crosslinkable hydrocarbon-based copolymer macromonomer consisting only of carbon and hydrogen atoms and containing an aromatic vinyl group functional group. Cured products obtained from compositions of similar olefin-aromatic vinyl compound-aromatic polyene copolymers and auxiliary materials, etc., are characterized by low dielectric constants and low dielectric loss tangents, and a wide range of physical properties, from soft to hard, can be imparted by selecting the composition and appropriate auxiliary materials (Patent Documents 3 and 4). The ethylene-styrene-divinylbenzene copolymer specifically described is a curable soft copolymer with excellent low dielectric properties, and cured products of compositions containing this also have excellent low dielectric performance, but recently there has been a demand for even higher levels of low dielectric properties.

[0004] Japanese Patent Application Laid-Open No. 6-192392 Japanese Patent Application Laid-Open No. 2009-161743 International Publication No. 2021 / 112087 International Publication No. 2022 / 014599

[0005] In recent years, there has been a demand for curable copolymer compositions that have even lower dielectric properties and can exhibit a wide range of physical properties from soft to hard, and in one embodiment, the present invention aims to provide a copolymer composition that satisfies this demand. In another embodiment, the present invention aims to provide a cured product of the copolymer composition.

[0006] In view of the above-mentioned problems, the present inventors have conducted extensive research and have found that the above-mentioned problems can be solved by a copolymer composition containing an α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer, which has excellent low dielectric properties and is relatively hard, and an α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer, which also has excellent low dielectric properties and is relatively hard, and a cured product thereof.

[0007] [Aspect 1] A copolymer composition comprising: an α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (A) satisfying all of the following conditions (i) to (vii): (i) a number average molecular weight of 500 or more and 30,000 or less; (ii) a glass transition temperature measured by DSC of 150°C or more and 250°C or less; (iii) the α-olefin monomer is an α-olefin having 2 to 20 carbon atoms, and the content of its monomer units is 0% by mass or more and less than 10% by mass; (iv) the aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of its monomer units is 0% by mass or more and less than 20% by mass; (v) the cyclic olefin monomer is a cyclic olefin having 7 to 30 carbon atoms, and the content of its monomer units is 60% by mass or more and less than 90% by mass. (vi) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms and having a plurality of vinyl groups and / or vinylene groups in the molecule, and the content of vinyl groups and / or vinylene groups derived from the aromatic polyene units contained in the copolymer is 2 or more per number-average molecular weight, and the number-average molecular weight per vinyl group and / or vinylene group derived from the aromatic polyene monomer units is 250 to 10,000. (vii) The total content (mass %) of each monomer unit of an α-olefin, a cyclic olefin, an aromatic vinyl compound, and an aromatic polyene is 100 mass %. An α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (B) that satisfies all of the following conditions (a) to (g): (a) the number-average molecular weight is 500 to 30,000. (b) the glass transition temperature measured by DSC is -30°C to 35°C. (c) The α-olefin monomer is an α-olefin having 2 to 20 carbon atoms, and the content of its monomer units is 15% by mass or more and less than 40% by mass. (d) The aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of its monomer units is 25% by mass or more and less than 50% by mass. (e) The cyclic olefin monomer is a cyclic olefin having 7 to 30 carbon atoms, and the content of its monomer units is 10% by mass or more and less than 50% by mass.(f) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms and containing multiple vinyl and / or vinylene groups in the molecule, and the content of vinyl and / or vinylene groups derived from the aromatic polyene units contained in the copolymer is 2 or more per number-average molecular weight, and the number-average molecular weight per vinyl and / or vinylene group derived from the aromatic polyene monomer units is 250 to 10,000. (g) The total content (mass %) of the α-olefin, cyclic olefin, aromatic vinyl compound, and aromatic polyene monomer units is 100 mass %. The mass ratio B / A of these components is 0.11 or more and 9.00 or less. [Aspect 2] A compatibilized α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer composition having glass transition temperatures in the ranges of at least -30 to 35°C and 150 to 250°C, and satisfying all of the following (1) to (4): (1) The α-olefin units are α-olefins having 2 to 20 carbon atoms. (2) The aromatic vinyl compound units are aromatic vinyl compounds having 8 to 20 carbon atoms. (3) The cyclic olefin units are cyclic olefin monomer units having 7 to 30 carbon atoms. (4) The aromatic polyene units are one or more selected from polyenes having 5 to 20 carbon atoms and having a plurality of vinyl groups and / or vinylene groups in the molecule. [Aspect 3] The copolymer composition according to Aspect 2, having a number average molecular weight in the range of 500 to 30,000. [Aspect 4] The copolymer composition according to Aspect 2 or 3, having a content of α-olefin monomer units of 1 to 25% by mass, a content of aromatic vinyl compound monomer units of 5 to less than 30% by mass, and a content of cyclic olefin monomer units of 30 to less than 75% by mass. [Aspect 5] The copolymer composition according to Aspect 2 or 3, wherein the content of vinyl groups and / or vinylene groups derived from aromatic polyene units contained in the copolymer is 2 or more per number average molecular weight, and the number average molecular weight per vinyl group and / or vinylene group derived from aromatic polyene monomer unit is 250 or more and 10,000 or less. [Aspect 6] A cured product of the copolymer composition according to Aspect 1 or 2.[Aspect 7] The cured product according to Aspect 6, having a dielectric constant of 2.0 or more and less than 2.5, and a dielectric dissipation factor of 0.0002 or more and less than 0.0010, measured at 23°C and 40 GHz. [Aspect 8] The cured product according to Aspect 6, having a Df(40 GHz / 10 GHz) value of 1.40 or less, which is the ratio of the dielectric dissipation factor measured at 23°C and 40 GHz to the dielectric dissipation factor measured at 23°C and 10 GHz by a cavity resonator perturbation method (split cylinder resonator method). [Aspect 9] The cured product according to Aspect 6, having a coefficient of linear expansion (CTE) from 0°C to 150°C of 150 ppm / K or less. [Aspect 10] The cured product according to Aspect 6, having a storage modulus (E') at 25°C of 0.5 GPa or more and a storage modulus (E') at 280°C of 2.0 MPa or more.

[0008] The copolymer composition according to the present invention is a composition comprising a soft copolymer having a glass transition temperature of 35° C. or lower and a hard copolymer having a glass transition temperature of 150° C. or higher, and a cured product thereof has excellent dielectric properties. In some embodiments of the present invention, such a copolymer composition exhibits good compatibility in a toluene solution and is easy to handle, and a cured product thereof has excellent mechanical properties such as storage modulus at room temperature and at high temperatures.

[0009] Next, embodiments of the present invention will be described in detail. It should be understood that the present invention is not limited to the following embodiments, and that appropriate design changes and improvements may be made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention.

[0010] Unless otherwise specified, the numerical ranges in this specification include the upper and lower limits. In this specification, the term "sheet" also encompasses the concept of "film." Furthermore, even when the term "film" is used in this specification, it is intended to have the same meaning as "sheet." Furthermore, even when the term "film" is used in this specification, it is intended to encompass the concept of "sheet."

[0011] In one embodiment of the present invention, a copolymer composition containing an α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer can be provided. A cured product of the copolymer composition may exhibit a dielectric constant at 23°C and a measurement frequency of 40 GHz of preferably 2.0 or more and less than 3.5, more preferably 2.0 or more and less than 2.5, and a dielectric dissipation factor of preferably 0.0002 or more and less than 0.0015, more preferably 0.0002 or more and less than 0.0010, and even more preferably 0.0002 or more and less than 0.00060. A cured product of the copolymer composition may exhibit a storage modulus (E') at 25°C of preferably 0.5 GPa or more and 5 GPa or less, more preferably 0.5 GPa or more and less than 3 GPa. By adjusting the blending ratio of the composition of the present invention, a cured product with a wide range of storage modulus (25°C) can be obtained. Furthermore, the storage modulus measured at 280°C is preferably 1 MPa or more and 1 GPa or less, more preferably 2 MPa or more and 1 GPa or less.

[0012] In another embodiment, it is also possible to provide an embodiment in which the dielectric constant or dielectric loss tangent of the copolymer composition in an uncured state does not satisfy the above conditions, but the dielectric constant, dielectric loss tangent, and storage modulus of the cured product satisfy the above conditions.

[0013] <α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer composition> The present invention relates to an α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (A) that satisfies all of the following conditions (i) to (vii): (i) the number average molecular weight is 500 or more and 30,000 or less; (ii) the glass transition temperature measured by DSC (differential scanning calorimetry) is 150°C or more and 250°C or less; (iii) the α-olefin monomer is an α-olefin having 2 to 20 carbon atoms, and the content of its monomer units is 0% by mass or more and less than 10% by mass; (iv) the aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of its monomer units is 0% by mass or more and less than 20% by mass; and (v) the cyclic olefin monomer is a cyclic olefin having 7 to 30 carbon atoms, and the content of its monomer units is 60% by mass or more and less than 90% by mass. (vi) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms and having a plurality of vinyl groups and / or vinylene groups in the molecule, and the content of vinyl groups and / or vinylene groups derived from the aromatic polyene units contained in the copolymer is 2 or more per number-average molecular weight, and the number-average molecular weight per vinyl group and / or vinylene group derived from the aromatic polyene monomer units is 250 to 10,000. (vii) The total content (mass %) of each monomer unit of an α-olefin, a cyclic olefin, an aromatic vinyl compound, and an aromatic polyene is 100 mass %. An α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (B) that satisfies all of the following conditions (a) to (g): (a) the number-average molecular weight is 500 to 30,000. (b) the glass transition temperature measured by DSC is -30°C to 35°C. (c) The α-olefin monomer is an α-olefin having 2 to 20 carbon atoms, and the content of its monomer units is 15% by mass or more and less than 40% by mass. (d) The aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of its monomer units is 25% by mass or more and less than 50% by mass. (e) The cyclic olefin monomer is a cyclic olefin having 7 to 30 carbon atoms, and the content of its monomer units is 10% by mass or more and less than 50% by mass.(f) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms and containing multiple vinyl and / or vinylene groups in the molecule, and the content of vinyl and / or vinylene groups derived from the aromatic polyene units contained in the copolymer is 2 or more per number-average molecular weight, and the number-average molecular weight per vinyl and / or vinylene group derived from the aromatic polyene monomer units is 250 to 10,000. (g) The total content (mass %) of the α-olefin, cyclic olefin, aromatic vinyl compound, and aromatic polyene monomer units is 100 mass %. The copolymer composition is blended in such a way that the mass ratio B / A is 0.11 or more and 9.00 or less (i.e., 1:9 to 9:1). If the mass ratio B / A is less than 0.11, the resulting composition and its cured product may be brittle and easily cracked, especially when formed into a sheet. Furthermore, if the mass ratio B / A is greater than 9.00, the resulting composition or its cured product, particularly when made into a sheet, may have insufficient rigidity or a particularly high linear expansion coefficient, and may not satisfy the criteria of the present invention.

[0014] These α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymers A and B can be obtained by copolymerizing the respective monomers of α-olefin, cyclic olefin, aromatic vinyl compound, and aromatic polyene.

[0015] The α-olefin monomer (which refers to a monomer that is the basis of the α-olefin monomer units in the copolymer, but in this specification, the terms "monomer" and "monomer unit (or unit)" may be used interchangeably depending on the context. The same applies to similar terms hereinafter) is an α-olefin having from 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 3,5,5-trimethyl-1-hexene, and is one or more selected from these. Ethylene is the most preferred.

[0016] In the α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (A) of the present invention, the α-olefin monomer is an α-olefin having 2 to 20 carbon atoms, and the content of its monomer units is 0% by mass or more and less than 10% by mass. The content of the α-olefin monomer units may be 0% by mass. In the α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (B) of the present invention, the α-olefin monomer is an α-olefin having 2 to 20 carbon atoms, and the content of its monomer units is 15% by mass or more and less than 40% by mass.

[0017] As used herein, the term "cyclic olefin monomer" refers to a cyclic olefin having 7 to 30 carbon atoms. Cyclic olefins having 7 to 30 carbon atoms include cyclic olefins having one or more alicyclic structures in the molecule and a polymerizable vinyl group, vinylene group, or vinylidene group. Preferred cyclic olefins are cyclic olefins having a hydrocarbon ring structure without heteroatoms, and cyclic olefins having an unsaturated hydrocarbon ring are more preferred. Such cyclic olefins are characterized by low dielectric properties and high glass transition temperatures, while also possessing the notable advantage of being easily prepared using inexpensive raw materials and simple processes compared to conventional engineering plastics. Examples of such cyclic olefins include norbornenes and acenaphthylene. Norbornenes are monomers selected from norbornene and substituted norbornenes. Norbornene can be synthesized, for example, by the Diels-Alder reaction of ethylene and cyclopentadiene. The substituted norbornene is a substituted norbornene having a polymerizable vinyl group, vinylene group, or vinylidene group in the molecule, and examples thereof include dimethanooctahydronaphthalene (DMON) and trimethanododecahydroanthracene (TMDA). These are also Diels-Alder reaction products of norbornenes and cyclopentadiene. These substituted norbornenes are specifically described, for example, in International Publication No. 2006 / 118261. In the present invention, more preferred cyclic olefins are those having a larger number of ring structures and a higher molecular weight, such as dimethanooctahydronaphthalene (DMON) and trimethanododecahydroanthracene (TMDA). Copolymerization of such cyclic olefins allows for the production of copolymers with a higher glass transition temperature (Tg) at a lower mole percent content of the monomer unit. These high molecular weight cyclic olefins may be used alone or as a mixture with norbornene or the like for copolymerization.

[0018] In particular, when the above-mentioned DMON or TMDA is produced by the Diels-Alder reaction, it may be obtained as a mixture with norbornene, and by using the mixture as it is for polymerization, it is possible to reduce the production cost. Furthermore, in the present invention, more preferred cyclic olefins are norbornenes having an aromatic substituent, and examples thereof include phenylnorbornene (5-phenylbicyclo[2.2.1]hept-2-ene), which is a Diels-Alder reaction product of cyclopentadiene and styrene, indanylnorbornene (1,4-methano-1,9a,4,4a-tetrahydrofluorene), which is a Diels-Alder reaction product of cyclopentadiene and indene, and methylphenylnorbornene (MPNB, 5-methyl-5-phenylbicyclo[2.2.1]hept-2-ene), which is a Diels-Alder reaction product of cyclopentadiene and α-methylstyrene. Norbornenes having such aromatic substituents can impart a higher glass transition temperature (Tg) to the copolymer when copolymerized, and furthermore, because they exhibit aromaticity, they can exhibit high compatibility with other aromatic raw materials (crosslinkable soft resins and flame retardants). Furthermore, the use of methylphenylnorbornene (5-methyl-5-phenylbicyclo[2.2.1]hept-2-ene) is preferable because it can improve the thermal oxidation resistance of the resulting copolymer, as described in JP-A-2005-239975. Norbornenes having these aromatic substituents are specifically described, for example, in JP-A-11-504669 and JP-A-2005-239975. Those skilled in the art can appropriately adjust the type and content of the cyclic olefin monomer units used to achieve the desired glass transition temperature of each copolymer.

[0019] In a preferred embodiment, the cyclic olefin monomer units contained in the copolymer may include monomer units derived from one or more selected from the group consisting of norbornene, methylphenylnorbornene, substituted norbornenes other than methylphenylnorbornene, and dimethanooctahydronaphthalene, and more preferably, may include monomer units derived from one or more selected from the group consisting of norbornene, methylphenylnorbornene, and dimethanooctahydronaphthalene.

[0020] In the α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (A) of the present invention, the cyclic olefin monomer is a cyclic olefin having from 7 to 30 carbon atoms, and the content of the monomer unit is from 60% to less than 90% by mass. In the α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (B) of the present invention, the cyclic olefin monomer is a cyclic olefin having from 7 to 30 carbon atoms, and the content of the monomer unit is from 10% to less than 50% by mass.

[0021] The aromatic vinyl compound monomer is an aromatic vinyl compound having from 8 to 20 carbon atoms, such as styrene, paramethylstyrene, ethylvinylbenzene, paraisobutylstyrene, various vinylnaphthalenes, and various vinylanthracenes. Monomer units derived from aromatic vinyl compounds may be included in the copolymer as a result of copolymerization of aromatic vinyl compound components contained as impurities in the aromatic polyene used in polymerization. The content of aromatic vinyl compound monomer units in the copolymer is optional, but generally, the lower the content, the better the low dielectric properties. Furthermore, compatibility with cyclic olefin copolymers is improved. Conversely, a higher content of aromatic vinyl compound monomer units improves compatibility with other highly aromatic resin components and flame retardants. Those skilled in the art can adjust the content as appropriate according to the purpose. The aromatic vinyl compound monomer of this embodiment has at least one vinyl group or vinylene group within the monomer.

[0022] In the α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (A) of the present invention, the aromatic vinyl compound monomer is an aromatic vinyl compound having from 8 to 20 carbon atoms, and the content of its monomer units is from 0% to less than 20% by mass. The content of the aromatic vinyl compound monomer may be 0% by mass. In the α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (B) of the present invention, the aromatic vinyl compound monomer is an aromatic vinyl compound having from 8 to 20 carbon atoms, and the content of its monomer units is from 25% to less than 50% by mass.

[0023] The aromatic polyene monomer is a polyene having 5 to 20 carbon atoms and containing multiple vinyl groups and / or vinylene groups in its molecule, preferably a polyene having 8 to 20 carbon atoms. The aromatic polyene monomer is preferably a polyene having 8 to 20 carbon atoms and containing multiple vinyl groups in its molecule, more preferably various ortho-, meta-, and para-divinylbenzenes (abbreviated as DVB) or mixtures thereof, divinylnaphthalene, divinylanthracene, p-2-propenylstyrene, p-3-butenylstyrene, or other compounds having an aromatic vinyl structure and consisting essentially of carbon and hydrogen and substantially free of oxygen, nitrogen, and halogens. Furthermore, bifunctional aromatic vinyl compounds such as 1,2-bis(vinylphenyl)ethane (abbreviated as BVPE) described in JP 2004-087639 A can also be used. Among these, various ortho-, meta-, and para-divinylbenzenes or mixtures thereof are preferably used, and a mixture of meta- and para-divinylbenzene is most preferably used. In this specification, these divinylbenzenes are referred to as divinylbenzenes. When divinylbenzenes are used as aromatic polyenes, the vinyl groups contained in the divinylbenzene units are preferred because they have high crosslinking efficiency during curing treatment and facilitate curing. The content of vinyl groups and / or vinylene groups derived from aromatic polyene units contained in the copolymer is 2 or more per number-average molecular weight, and the number-average molecular weight of the copolymer per vinyl group and / or vinylene group derived from aromatic polyene monomer unit is 250 or more and 10,000 or less, preferably 300 or more and 5,000 or less. This value can be obtained by dividing the number-average molecular weight (Mn) of the copolymer by the number of vinyl groups and / or vinylene groups derived from aromatic polyene units contained per number-average molecular weight.

[0024] Furthermore, in the copolymer of the present invention, the content of vinyl groups and / or vinylene groups derived from the aromatic polyene monomer units may be 2 to 30, preferably 3 to 20, per number-average molecular weight. The content of vinyl groups and / or vinylene groups derived from the aromatic polyene monomer units may be less than 30, preferably less than 20, per number-average molecular weight. The content of vinyl groups and / or vinylene groups may be collectively referred to as the "vinyl group content" below. Because vinyl groups are superior to vinylene groups in terms of crosslinking efficiency, in the present invention, the content of vinyl groups (excluding vinylene groups in this case) derived from the aromatic polyene monomer units is preferably 2 to 30, preferably 3 to 20, per number-average molecular weight. A vinyl group content of 2 or more results in high crosslinking efficiency and a cured product with sufficient crosslink density. Increasing the vinyl group content facilitates improving the mechanical properties of the final cured product at room temperature and high temperatures. The vinyl group content derived from aromatic polyene monomer units (divinylbenzene monomer units) per number average molecular weight in the copolymer is determined by the ratio of the number average molecular weight (Mn) calculated in terms of standard polystyrene obtained by a GPC (gel permeation chromatography) method known to those skilled in the art to ... 1 H-NMR measurement and / or quantitative mode 13 This can be obtained by comparing the composition obtained by C-NMR measurement with the vinyl group content derived from the aromatic polyene monomer units. Such a method is obvious and well known to those skilled in the art. It is also possible to use the methods described in the patent documents in the prior art literature of this specification. The content of aromatic polyene monomer units in the copolymer of the present invention is arbitrary, but may be preferably less than 40% by mass, more preferably less than 30% by mass, while satisfying the above conditions. At such a content, the number of crosslinking groups is appropriately suppressed, and the effect of improving the stability during copolymer production and curing is obtained.

[0025] The number-average molecular weight of the copolymer of the present invention is preferably 500 to 30,000, more preferably 500 to 20,000, and even more preferably 500 to 15,000. A number-average molecular weight of 500 or more improves the mechanical properties of the composition in the uncured state and provides moderate adhesion, thereby facilitating molding and processing as a thermoplastic resin. A number-average molecular weight of 30,000 or less improves molding processability. A number-average molecular weight of 30,000 or less, or 12,000 or less, is particularly advantageous because it allows the viscosity of a varnish containing the copolymer to be kept below a certain value. A varnish with a viscosity lower than a certain value improves workability and facilitates impregnation of glass fibers and the like with the varnish, improving embeddability in semiconductor devices with uneven surfaces.

[0026] In one embodiment of the copolymer of the present invention, the α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer specifically includes at least one member selected from the group consisting of ethylene-norbornene-divinylbenzene copolymer, propylene-norbornene-styrene-divinylbenzene copolymer, 1-hexene-norbornene-styrene-divinylbenzene copolymer, 1-octene-norbornene-styrene-divinylbenzene copolymer, ethylene-norbornene-ethylvinylbenzene-divinylbenzene copolymer, propylene-styrene-norbornene-divinylbenzene copolymer, 1-hexenestyrene-styrene-norbornene-divinylbenzene copolymer, and 1-octene-norbornene-styrene-divinylbenzene copolymer. Furthermore, copolymers in which the above-mentioned norbornene is replaced with dimethanooctahydronaphthalene (DMON), trimethanododecahydroanthracene (TMDA), phenylnorbornene (5-phenylbicyclo[2.2.1]hept-2-ene), or methylphenylnorbornene (5-methyl-5-phenylbicyclo[2.2.1]hept-2-ene) are also suitable examples of copolymers of the present invention.

[0027] The α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer of the present invention can be sufficiently cured by being cured alone. Here, "curing alone" refers to adding an azo-based radical curing agent in an amount of 1 part by mass or less to 100 parts by mass of the copolymer and performing a curing treatment under curing conditions appropriate for the curing agent used. The degree of curing can be evaluated by the gel content, which is greater than 80%, preferably 90% or more, and particularly preferably 95% or more. The cured product exhibits excellent low dielectric properties and has a storage modulus at 25°C and 280°C within the range of the present invention. Specifically, the cured product may have a dielectric constant of 2.0 or more but less than 2.5, and a dielectric dissipation factor of 0.0001 or more but less than 0.0010, preferably 0.0002 or more but less than 0.00060. The cured product may exhibit a storage modulus at 25°C of 0.5 GPa, more preferably 1.0 GPa or more, and a storage modulus measured at 280°C of 2 MPa or more, more preferably 3 MPa or more. Here, the gel content is a value obtained in accordance with JIS K6796:1998 (or ASTM D2765-84, which corresponds to ISO10147:1994, which corresponds to JIS), and the dielectric constant and dielectric dissipation factor are values ​​obtained at 23°C and 40 GHz. The glass transition temperature is obtained by DSC measurement, and the storage modulus at each temperature is obtained by dynamic mechanical analysis (DMA) at a measurement frequency of 1 Hz. It is also possible to obtain a cured product obtained by curing a composition containing this copolymer, which has a sufficiently high gel content, and the cured product can exhibit excellent low dielectric properties.

[0028] <Compositions containing the copolymers of the present invention> The copolymer compositions of the present invention can be cured alone, but they may also be combined with other materials to form compositions, and the resulting compositions can be cured. Here, the other materials include the following "resin components," "curing agents," "monomers," "solvents," "fillers," "other additives," etc.

[0029] <Resin Component> Any resin component can be used as long as it does not impair the effects of the present invention, but preferably one or more selected from hydrocarbon elastomers, polyether resins, aromatic polyene resins, and olefin-aromatic vinyl compound-aromatic polyene copolymers not containing cyclic olefins can be used. Of these, polyether resins and aromatic polyene resins are more preferred. The amount of the resin component may be preferably in the range of 1 to 500 parts by mass, more preferably 1 to 300 parts by mass, in total, per 100 parts by mass of the copolymer of the present invention.

[0030] <Hydrocarbon Elastomer> Hydrocarbon elastomers suitable for use in the composition of the present invention may have a number-average molecular weight of 20,000 or more, preferably 30,000 or more. Examples of hydrocarbon elastomers include one or more elastomers selected from ethylene-based or propylene-based elastomers, conjugated diene polymers, block or random copolymers of aromatic vinyl compounds and conjugated dienes, and hydrogenated products thereof. Examples of ethylene-based elastomers include ethylene-α-olefin copolymers such as ethylene-octene copolymers and ethylene-1-hexene copolymers, EPR, and EPDM. Examples of propylene-based elastomers include atactic polypropylene, low stereoregular polypropylene, and propylene-α-olefin copolymers such as propylene-1-butene copolymer. These hydrocarbon elastomers may be modified, for example, by introducing functional groups with maleic anhydride or other compounds.

[0031] <Conjugated Diene Polymer> Examples of conjugated diene polymers include polybutadiene and 1,2-polybutadiene. Examples of aromatic vinyl compound-conjugated diene block or random copolymers and their hydrogenated products (hydrogenated products) include SBS, SIS, SEBS, SEPS, SEEPS, and SEEBS. Suitable 1,2-polybutadiene is available, for example, as a product from JSR Corporation, and also available from Nippon Soda Co., Ltd. under the product names of liquid polybutadiene B-1000, 2000, and 3000. Another suitable copolymer containing a 1,2-polybutadiene structure is "Ricon 100" from TOTAL CRAY VALLEY. These conjugated diene polymers and hydrogenated products thereof may be modified, for example, by introducing functional groups with maleic anhydride or other compounds. Among the conjugated diene polymers, conjugated diene copolymers are preferred. Among these conjugated diene copolymers, hydrogenated block copolymers such as SEBS, SEPS, SEEPS, and SEEBS are useful as compatibilizers for the copolymer of the present invention and other resin components. These are available from Asahi Kasei under the trade names Tuftec or SOE-SS, from Kuraray Co., Ltd. under the trade name Septon, and from KRATON under the trade name Kraton.

[0032] <Polyether-Based Resin> Examples of polyether-based resins include polyphenylene ether and polyether. Polyphenylene ethers having functional groups are preferably those in which the molecular terminals are modified with functional groups. Furthermore, when added for the purpose of curing the composition of the present invention, it is preferable that the polyphenylene ether has multiple functional groups in one molecule. For example, modified polyphenylene ether is preferable. Examples of functional groups include radically polymerizable functional groups and epoxy groups, and preferably radically polymerizable functional groups. A vinyl group is preferable as the radically polymerizable functional group. As the vinyl group, one or more of the group consisting of an allyl group, a (meth)acryloyl group, and an aromatic vinyl group are preferable, one or more of the group consisting of a (meth)acryloyl group and an aromatic vinyl group are more preferable, and an aromatic vinyl group is most preferable. In other words, in the composition of the present invention, a bifunctional polyphenylene ether in which both molecular chain terminals are modified with radically polymerizable functional groups is particularly preferable. Examples of such polyphenylene ethers include Noryl (trademark) SA9000 manufactured by SABIC (modified polyphenylene ether having methacryloyl groups at both ends, number average molecular weight 2200) and bifunctional polyphenylene ether oligomer manufactured by Mitsubishi Gas Chemical Company, Inc. (OPE-2St, modified polyphenylene ether having vinylbenzyl groups at both ends, number average molecular weight 1200). Also usable are allylated PPE manufactured by Asahi Kasei Corporation and aromatic polyethers (ELPAC HC-F series) manufactured by JSR Corporation. Of these, the bifunctional polyphenylene ether oligomer (OPE-2St) manufactured by Mitsubishi Gas Chemical Company, Inc. and aromatic polyethers (ELPAC HC-F series) manufactured by JSR Corporation are preferred.

[0033] <Aromatic Polyene Resin> Aromatic polyene resins include divinylbenzene-based reactive hyperbranched copolymers (PDV or ODV) manufactured by Nippon Steel Chemical & Material Co., Ltd. Such copolymers are described, for example, in the literature "Synthesis of Polyfunctional Aromatic Vinyl Copolymers and Development of New IPN-Type Low Dielectric Loss Materials Using the Same" (Kawabe Masanao et al., Journal of the Japan Institute of Electronics Packaging, p. 125, Vol. 12, No. 2 (2009)). Aromatic polyene resins are resins (copolymers) essentially composed of aromatic polyene monomer units and aromatic monovinyl compound monomer units, and more preferably, aromatic polyene resins do not contain olefin monomer units. Aromatic polyene resins are preferably resins obtained by cationic polymerization or anionic polymerization. These can be used alone or in any combination of two or more.

[0034] <Another olefin-aromatic vinyl compound-aromatic polyene copolymer not containing a cyclic olefin> The other olefin-aromatic vinyl compound-aromatic polyene copolymer not containing a cyclic olefin that can be used in the present invention is an olefin-aromatic vinyl compound-aromatic polyene copolymer that satisfies all of the following (A) to (E): (A) The number average molecular weight of the copolymer is 500 or more and 100,000 or less. (B) The olefin monomer unit is one or more α-olefins selected from α-olefins having 2 to 20 carbon atoms, and this olefin does not contain a cyclic olefin. (C) The aromatic vinyl compound monomer unit is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of the aromatic vinyl compound monomer unit is 0% by mass or more and 90% by mass or less. (C) The content of the aromatic vinyl compound monomer unit may be 0% by mass. (D) The aromatic polyene monomer units are one or more selected from polyenes having 5 to 20 carbon atoms and having a plurality of vinyl groups and / or vinylene groups in the molecule, and the content of vinyl groups and / or vinylene groups derived from the aromatic polyene units is 2 to 30 per number average molecular weight. The content of vinyl groups and / or vinylene groups derived from the aromatic polyene units may be 2 to less than 30 per number average molecular weight. (E) The total of the olefin monomer units, aromatic vinyl compound monomer units, and aromatic polyene monomer units is 100 mass%.

[0035] Details of the α-olefin, aromatic vinyl compound, and aromatic polyene monomers are as described above. Such copolymers are specifically described in JP 2009-161743 A, WO 2021 / 112087, WO 2021 / 112088, and WO 2022 / 014599. However, as described above, these other copolymers do not contain cyclic olefins. Among olefin-aromatic vinyl compound-aromatic polyene copolymers that do not contain cyclic olefins, copolymers having an aromatic vinyl compound monomer content of 0 to 60% by mass are particularly soft, and therefore, by blending them with the copolymer of the present invention, the toughness of the resulting cured body can be improved and cracking can be suppressed, making them preferable.

[0036] <Curing Agent> The curing agent that may be included in the composition of the present invention may be a known curing agent that has been conventionally used for the polymerization or curing of aromatic polyenes or aromatic vinyl compounds. Examples of such curing agents include radical polymerization initiators, cationic polymerization initiators, and anionic polymerization initiators, with radical polymerization initiators being preferred. Organic peroxides, and even more preferably azo polymerization initiators, are preferred, and can be freely selected depending on the application and conditions. Catalogs listing organic peroxides can be downloaded from the NOF Corporation website, for example, https: / / www.nof.co.jp / product-search / family / 1020001. Organic peroxides are also listed in catalogs from Fujifilm Wako Pure Chemical Industries, Ltd. and Tokyo Chemical Industry Co., Ltd. The curing agents used in the present invention can be obtained from these companies. Furthermore, hydrocarbon-based radical polymerization initiators that do not contain oxygen or nitrogen atoms in their structure, i.e., radical polymerization initiators composed only of carbon and hydrogen atoms, such as 2,3-dimethyl-2,3-diphenylbutane, can also be suitably used. When a cured product is produced using such a hydrocarbon-based radical polymerization initiator, a cured product containing no oxygen or nitrogen atoms can be obtained with a lower dielectric constant and dielectric dissipation factor, further improving the low dielectric properties of the cured product. Azo-based polymerization initiators are also preferred because the nitrogen atoms contained in the polar group upon radical generation are released from the system as nitrogen gas, resulting in a cured product with even lower dielectric properties. Known photopolymerization initiators that utilize light, ultraviolet light, or radiation can also be used as curing agents. Examples of curing agents that utilize a photopolymerization initiator include photoradical polymerization initiators, photocationic polymerization initiators, and photoanionic polymerization initiators. Such photopolymerization initiators are available, for example, from Tokyo Chemical Industry Co., Ltd. Furthermore, curing using radiation or electron beams themselves is also possible. Crosslinking and curing by thermal polymerization of the raw materials contained therein can also be performed without the use of a curing agent.

[0037] There are no particular restrictions on the amount of curing agent used, but generally, an amount of 0.01 to 10 parts by mass per 100 parts by mass of the composition (preferably excluding the curing agent and solvent) is preferred. When using a curing agent such as a peroxide or azo-based polymerization initiator, the curing treatment is carried out at an appropriate temperature and time, taking into account its half-life. In this case, the conditions are optional depending on the curing agent, but generally, a temperature range of approximately 50°C to 200°C is appropriate.

[0038] <Monomer> The composition of the present invention may contain any amount of monomer, but preferably 300 parts by weight or less per 100 parts by weight of copolymer. The composition may be substantially free of monomer. If a monomer is contained, the amount is preferably 1 part by weight or more, more preferably 5 parts by weight or more. In particular, when the monomer content is 30 parts by weight or less, the uncured composition is less likely to become viscous, facilitating molding and processing as a thermoplastic resin. Furthermore, when the content of volatile monomers is below a certain level, odor in the uncured state is not a problem. When a solvent is added to the composition to produce a varnish-like product, the monomer is lost as the solvent evaporates during use, which can lead to a problem of a decrease in the actual content of the monomer. Furthermore, when the product is in the form of an uncured sheet, containing a certain amount or less of monomer reduces the change in the monomer content during storage. Monomers suitable for use in the composition of the present invention preferably have a molecular weight of less than 1,000, more preferably less than 500. Monomers that can be suitably used in the composition of the present invention are the aromatic vinyl compound monomers described above, the aromatic polyene monomers described above, the aromatic vinylene monomers described below, and / or the polar monomers described below. The monomers are preferably monomers that can be polymerized with a radical polymerization initiator, and more preferably one or more from the group consisting of aromatic vinyl compounds and aromatic polyenes. Also suitable for use is BVPE (1,2-bis(vinylphenyl)ethane) described in JP-A-2003-212941.

[0039] <Aromatic Vinylene Monomer> The aromatic vinylene monomer that may be included in the present invention refers to a compound having both a single aromatic ring or multiple condensed aromatic rings having 9 to 30 carbon atoms and a vinylene group. Examples of such aromatic vinylene compounds include indenes, beta-substituted styrenes, acenaphthylenes, etc. Examples of indenes include indene, various alkyl-substituted indenes, and phenyl-substituted indenes. Examples of beta-substituted styrenes include beta-alkyl-substituted styrenes such as beta-methylstyrene, and phenyl-substituted styrenes. Examples of acenaphthylenes include acenaphthylene, various alkyl-substituted acenaphthylenes, and various phenyl-substituted acenaphthylenes. As the aromatic vinylene compound, the above-exemplified compounds may be used alone or in combination of two or more. From the viewpoints of industrial availability and radical polymerizability, acenaphthylene is the most preferred aromatic vinylene compound.

[0040] <Polar Monomer> A relatively small amount of polar monomer can be used to impart adhesion to other materials required as an insulating material. Examples of the polar monomer include various maleimides, bismaleimides, maleic anhydride, glycidyl (meth)acrylate, triallyl isocyanurate, tri(meth)acrylic isocyanurate, and trimethylolpropane tri(meth)acrylate. Maleimides and bismaleimides that can be used in the present invention are described, for example, in International Publication No. 2016 / 114287 and can be purchased, for example, from Daiwa Kasei Co., Ltd. These maleimide group-containing compounds may be used as polyaminobismaleimide compounds from the viewpoints of solubility in organic solvents, high-frequency characteristics, high adhesion to conductors, and prepreg moldability. Polyaminobismaleimide compounds can be obtained, for example, by subjecting a compound having two maleimide groups at its terminals to a Michael addition reaction with an aromatic diamine compound having two primary amino groups in its molecule. When attempting to obtain high crosslinking efficiency with the addition of a small amount, it is preferable to use a polar monomer having a multifunctional group of at least two functional groups, and examples thereof include bismaleimides, triallyl isocyanurate (TAIC), and trimethylolpropane tri(meth)acrylate. The amount of polar monomer that may be contained in the composition may be in the range of 0.1 to 30 parts by mass, preferably 0.1 to 10 parts by mass, per 100 parts by mass of the copolymer of the present invention. By using 30 parts by mass or less, the dielectric constant and dielectric dissipation factor of the obtained cured body become low. For example, in a preferred embodiment, the dielectric constant of the cured body of the copolymer is 3.5 or less, and the dielectric dissipation factor is 1.2 x 10 -3 It is possible to reduce it to the following:

[0041] <Solvent> An appropriate solvent may be added to the composition of the present invention as needed. The solvent is used to adjust the viscosity and fluidity of the composition. Volatile solvents are preferred, such as cyclohexane, toluene, ethylbenzene, acetone, and isopropanol. The solvent is used to adjust the viscosity and fluidity of the composition as a varnish. A solvent with a high boiling point at atmospheric pressure, i.e., low volatility, results in a uniform thickness of the applied film, so a solvent with a boiling point of at least a certain level is preferred. A preferred boiling point is 100°C or higher, more preferably 130°C or higher and 300°C or lower, at atmospheric pressure. Solvents suitable for such varnishes include cyclohexane, toluene, xylene, mesitylene, tetralin, acetone, ethylbenzene, limonene, mixed alkanes, mixed aromatic solvents, ethylene glycol methyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether. In the case of a solvent, the amount used is preferably in the range of 10 to 2,000 parts by mass, more preferably 5 to 500 parts by mass, and even more preferably 10 to 300 parts by mass, per 100 parts by mass of the composition of the present invention. The solvent is preferably removed by a drying treatment or the like before curing the composition.

[0042] <Filler> The composition of this embodiment may contain a conventionally known filler, if necessary. Either inorganic or organic fillers can be used as the filler, and the type is not particularly limited. These fillers can be added for purposes such as controlling the thermal expansion coefficient, controlling thermal conductivity, and reducing cost. The amount used can be appropriately determined as needed and is not particularly limited. When adding an inorganic filler, it is preferable to use a known surface modifier, such as a silane coupling agent. In particular, when aiming for a cured product with excellent low dielectric constant and low dielectric loss, the inorganic filler is preferably one or more of boron nitride (BN) or silica, with silica being more preferred. Fused silica is preferred as the silica. From the perspective of low dielectric properties, a filler may be used in an amount of preferably 400 parts by mass, more preferably 100 parts by mass or less, per 100 parts by mass of the crosslinkable copolymer. Furthermore, a hollow filler or a filler with many voids may be added to improve and enhance low dielectric properties (low dielectric constant, low dielectric loss tangent). These fillers may be used alone or in any combination of two or more.

[0043] Furthermore, instead of inorganic fillers, organic fillers such as high molecular weight polyethylene, ultra-high molecular weight polyethylene, polystyrene, styrene-divinylbenzene copolymer, or fluorine-based resins can also be used. Examples of fluorine-based resins include known fluorine-containing resins such as PTFE (polytetrafluoroethylene) and PFA (perfluoroalkoxyalkane). An example of such a resin is Fluon+ (registered trademark) EA-2000 from AGC. When the melting point or glass transition temperature of the organic filler is lower than the solder reflow temperature of 290°C, it is preferable from the standpoint of heat resistance that the organic filler itself be crosslinked, and it is preferable that it be blended in the form of fine particles or powder. These organic fillers can also suppress increases in dielectric constant and dielectric loss tangent.

[0044] On the other hand, by mixing and dispersing a high-dielectric-constant insulating filler having a dielectric constant at 1 GHz of preferably 3 to 10,000, more preferably 5 to 10,000, into the composition of the present invention, it is possible to produce a cured insulating product having a high-dielectric-constant insulating layer with a dielectric constant of preferably 2.5 to 20, more preferably 2.8 to 10, while suppressing an increase in dielectric loss tangent (dielectric loss). Increasing the dielectric constant of a film made from the cured insulating product enables the miniaturization of circuits and the increase in capacitance of capacitors, contributing to the miniaturization of high-frequency electrical components. High-dielectric-constant, low-dielectric-loss-tangent insulating layers are suitable for applications such as capacitors, inductors for resonant circuits, filters, and antennas. Examples of high-dielectric-constant insulating fillers used in the present invention include inorganic fillers or metal particles that have been subjected to an insulating treatment. Specific examples include known high-dielectric-constant inorganic fillers such as barium titanate and strontium titanate. Other examples are specifically described, for example, in JP 2004-087639 A.

[0045] <Other Additives> The composition of the present invention may further contain one or more additives selected from a flame retardant and a surface modifier. The composition of the present invention can serve as a matrix for a cured body, and when cured, it has excellent filling properties for other materials. Therefore, the composition contains one or more additives selected from these fillers, flame retardants, and surface modifiers, and the cured body tends to exhibit impact resistance and toughness even after curing.

[0046] <Flame Retardant> A known flame retardant can be used in the composition of the present invention. Preferred flame retardants are known organic phosphorus-based flame retardants such as phosphate esters or condensates thereof, known bromine-based flame retardants, and red phosphorus, from the viewpoint of maintaining a low dielectric constant and a low dielectric loss tangent. Among phosphate esters, compounds having multiple xylenyl groups in the molecule are particularly preferred from the viewpoint of flame retardancy and a low dielectric loss tangent.

[0047] In addition to the flame retardant, antimony compounds such as antimony trioxide, antimony tetraoxide, antimony pentoxide, and sodium antimonate, or nitrogen-containing compounds such as melamine, triallyl-1,3,5-triazine-2,3,4-(1H,3H,5H)-trione, and 2,4,6-trialyloxy-1,3,5-triazine may be added as a flame retardant aid. The total amount of these flame retardants and flame retardant aids is usually preferably 1 to 100 parts by mass per 100 parts by mass of the composition. Furthermore, a polyphenylene ether (PPE) resin with a low dielectric constant and excellent flame retardancy may be used in an amount of 30 to 200 parts by mass per 100 parts by mass of the flame retardant.

[0048] <Surface Modifier> The composition of the present invention may contain various surface modifiers for the purpose of improving adhesion to fillers, copper plates, and wiring. The amount of the surface modifier used per 100 parts by mass of the composition of the present invention other than the surface modifier is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass. Examples of the surface modifier include various silane coupling agents and titanate coupling agents. Various silane coupling agents and titanate coupling agents may be used singly or in combination.

[0049] In the present invention, the flow temperature of the curable resin or composition can be adjusted to suit the purpose and molding method by changing the compounding ratio of the "resin component," "curing agent," "monomer," "solvent," "filler," or "other additives." Specifically, the composition of the present invention can take the form of a product such as a "thermoplastic composition," a "semi-cured state (such as a B-stage sheet)," or a "varnish."

[0050] The composition of the present invention can be obtained by mixing, dissolving or melting one or more of "resin components," "curing agents," "monomers," "solvents," "fillers," and "other additives," and can further include general additives that are added to ordinary resins, such as lubricants, stabilizers, antioxidants, weather resistance agents, ultraviolet absorbers, etc., to the extent that the object of the present invention is not impaired. Any known method can be used for mixing, dissolving or melting these.

[0051] <Composition of the Present Invention> The composition of the present invention is a compatibilized α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer composition that has a glass transition temperature in the ranges of at least -30 to 35°C and 150 to 250°C and satisfies all of the following (1) to (4): (1) The α-olefin unit is an α-olefin having 2 to 20 carbon atoms. (2) The aromatic vinyl compound unit is an aromatic vinyl compound having 8 to 20 carbon atoms. (3) The cyclic olefin unit is a cyclic olefin monomer unit having 7 to 30 carbon atoms. (4) The aromatic polyene unit is one or more polyenes selected from polyenes having 5 to 20 carbon atoms and having a plurality of vinyl groups and / or vinylene groups in the molecule.

[0052] The composition of the present invention preferably has a number average molecular weight in the range of 500 to 30,000. Furthermore, the composition of the present invention preferably has an α-olefin monomer unit content of 1% by mass or more and 25% by mass or less, an aromatic vinyl compound monomer unit content of 5% by mass or more and less than 30% by mass, and a cyclic olefin monomer unit content of 30% by mass or more and less than 75% by mass. Furthermore, the composition of the present invention preferably has a content of vinyl groups and / or vinylene groups derived from aromatic polyene units contained in the copolymer of 2 or more per number average molecular weight, and a number average molecular weight per vinyl group and / or vinylene group derived from aromatic polyene monomer unit of 250 or more and 10,000 or less.

[0053] <Composition and Molded Articles> The composition of the present invention can provide a relatively uniform varnish state. Furthermore, the composition of the present invention can provide a relatively uniform thermoplastic resin composition. Therefore, under conditions that do not cause crosslinking, the composition can be molded into a relatively uniform shape, such as a sheet, tube, strip, or pellet, in a substantially uncured state by known processing or molding methods for varnishes or thermoplastic resins. The molded article may be crosslinked (cured) after or during molding.

[0054] <Thermoplastic resin composition> When the resin component contains a certain proportion or more of one or more resins selected from the hydrocarbon elastomers, polyether resins, olefin-aromatic vinyl compound-aromatic polyene copolymers not containing cyclic olefins, and aromatic polyene resins, excluding resins that are liquid at room temperature, the composition is also easily molded into a thermoplastic resin in an uncured state. The thermoplastic composition described above can be molded into various shapes such as a sheet at or below the action temperature of the curing agent, utilizing its thermoplasticity, and then laminated and combined with a semiconductor element, wiring, or substrate as needed, and then heat-cured and bonded.

[0055] The composition of the present invention may be provided as a sheet obtained by molding the composition, heated and melted at a temperature below or equal to the curing agent's working temperature or decomposition temperature, using a known method. Forming into a sheet may be achieved by T-die extrusion, two-roll extrusion, or extrusion lamination onto a substrate film. In this case, the composition's composition, copolymer / monomer mass ratio, or solvent, resin component, and flame retardant are selected and adjusted so that the composition melts below or equal to the curing agent's working temperature or decomposition temperature and becomes solid at or near room temperature. In this case, the sheet is substantially uncured. After various processing and assembly steps, the sheet is finally treated at a temperature and time above the curing agent's working temperature or decomposition temperature to achieve complete curing. This method is a common technique used for ethylene-vinyl acetate resin-based crosslinked sealant sheets for solar cells (photovoltaic power generation devices).

[0056] <Varnish-like Composition and Molded Articles Thereof> The composition of the present invention can also be made into a viscous liquid varnish by adjusting its composition and blending ratio. For example, a sufficient amount of solvent and / or an appropriate amount of liquid monomer can be used to make the composition into a varnish. When used as a varnish, it is preferable to add an appropriate solvent to the composition of the present invention. The solvent is used to adjust the viscosity and fluidity of the composition as a varnish. A solvent with a high boiling point at atmospheric pressure, i.e., low volatility, contributes to a uniform thickness of the applied film, so a solvent with a boiling point above a certain level is preferred. A preferred boiling point is approximately 110°C or higher and 300°C or lower at atmospheric pressure. Examples of solvents suitable for such varnishes include toluene, xylene, mesitylene, ethylbenzene, limonene, ethylene glycol methyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether. The amount of the solvent used is preferably in the range of 10 to 2,000 parts by mass per 100 parts by mass of the composition of the present invention.

[0057] The varnish can be applied to or impregnated into a substrate, and the solvent or the like can be removed by drying or the like to produce an uncured or semi-cured molded article. This molded article generally has the form of a sheet, film, or tape. In this embodiment, the obtained uncured or semi-cured molded article is cured.

[0058] <Molded Article in a Semi-Cured State (B-Stage Sheet, etc.)> The composition of the present invention can also be formed into a molded article, such as a sheet or tube, in a partially crosslinked state, for example, a state in which a portion of the curing agent contained therein has reacted and been semi-cured (so-called B-stage state). Here, the semi-cured state is defined as a state in which the proportion of gel content as a resin component in the composition of the present invention is more than 20% by mass and not more than 80% by mass, independently of the definition of the uncured state. The gel content is a value obtained by measurement in accordance with JIS K6796:1998. For example, by employing multiple curing agents and / or curing conditions with different curing temperatures, the composition can be semi-cured, and the melt viscosity and fluidity can be controlled to achieve a B-stage state. That is, the curable resin or composition can be molded into an easily handleable B-stage sheet by a first curing step (partial curing), which can then be laminated and pressure-bonded to an electronic device or substrate, followed by a second curing step (complete curing) to form the final shape. In this case, the composition, i.e., the copolymer / monomer mass ratio, is selected, and if necessary, a solvent, resin component, and flame retardant are added. The composition further contains a curing agent such as a peroxide, which is partially cured and adjusted to a sheet shape (B-stage state). After molding and assembling the device, the composition can be heated under pressure to fully cure. Known methods can be used to partially cure the composition. For example, peroxides with different decomposition temperatures are used in combination, and the mixture is treated for a predetermined time at a temperature at which only one of the peroxides is substantially active to obtain a semi-cured sheet. Finally, the mixture is treated for a sufficient time at a temperature at which all of the curing agents are active to fully cure the sheet.

[0059] Furthermore, the molded article may be a sheet. The sheet may be uncured (semi-cured) to the extent that it can maintain its sheet shape, or may be fully cured. The degree of curing of the composition can be quantitatively measured by known dynamic mechanical analysis (DMA).

[0060] <Curing> The composition can be cured by a known method, taking into consideration the curing conditions (temperature, time, pressure) of the curing agent contained therein. When the curing agent used is a peroxide, the curing conditions can be determined by taking into consideration the half-life temperature and the like disclosed for each peroxide.

[0061] <Cured Product of Composition> The dielectric constant and dielectric loss tangent of the cured product obtained from the composition of the present invention are measured by a known resonator method. In this specification, the resonator method is performed at a measurement frequency of 40 GHz. The dielectric constant of the cured product of the present invention may be 2.0 or more and less than 3.5, preferably 2.0 or more and less than 2.5. The dielectric loss tangent of the cured product of the present invention may be 0.0002 or more and less than 0.0015, preferably 0.0002 or more and less than 0.0010, and more preferably 0.0002 or more and less than 0.00060. These values ​​are preferred for high-frequency electrical insulating materials, for example, at 3 GHz or more. The dielectric properties of the cured product obtained from the copolymer (composition) of the present invention, particularly the dielectric loss tangent, are characterized by little change with measurement frequency. The characteristic of low signal frequency dependence of the dielectric loss tangent is important for maintaining signal quality and suppressing noise generation. Specifically, the ratio of the dielectric loss tangent at 10 GHz measured by the cavity resonator perturbation method (split cylinder resonator method) at 23°C to the dielectric loss tangent at 40 GHz measured by the cavity resonator perturbation method (split cylinder resonator method) at 23°C, Df(40 GHz / 10 GHz), is preferably 1.40 or less, more preferably 1.30 or less. The lower limit of the ratio Df(40 GHz / 10 GHz) is preferably 0.80 or more, more preferably 1.0 or more. The cured product of the present invention has a storage modulus measured by DMA (25°C) of preferably 0.5 GPa to 5 GPa, more preferably 0.5 GPa to 3 GPa. Adjusting the compounding ratio of the composition of the present invention allows for a cured product with a wide range of storage modulus (25°C). The storage modulus measured at 280°C is preferably 1 MPa to 1 GPa, more preferably 2 MPa to 1 GPa. Furthermore, the coefficient of linear expansion (CTE) of the cured product of the present invention from 0°C to 150°C is 150 ppm / K or less. Those skilled in the art can determine the formulation of a composition having the above physical property parameters and produce a cured product by referring to the information described in this specification and publicly available documents. The cured product obtained from the composition of the present invention can exhibit practically sufficient heat resistance and mechanical properties at high temperatures, even under conditions in which the monomer in the composition and the aromatic polyene as a component of the monomer are kept below a certain ratio.

[0062] The composition of the present invention can be used as a base material or substrate, such as a single-layer or multi-layer printed circuit board, a flexible printed circuit board, a so-called single-layer or multi-layer CCL board, a single-layer or multi-layer FCCL board, or a single-layer or multi-layer RCC board. It can also be used as various electrical insulating materials for wiring, preferably for high-frequency signal wiring, such as coverlays, high-frequency transmission circuits, antennas, solder resists, build-up materials, interlayer insulating materials, bonding sheets, interlayer adhesives, and bump sheets for flip-chip bonders.

[0063] In another aspect, the present invention provides an electrical insulating material comprising an α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer, which, as a cured product, has a dielectric constant of 2.0 or more and less than 2.5, and a dielectric dissipation factor of 0.0002 or more and less than 0.0010, measured at 23°C and 40 GHz.

[0064] In one embodiment of the present invention, there is also provided a method for producing the copolymer. The production method includes copolymerizing each of the monomers of an α-olefin, a cyclic olefin, and an aromatic polyene by coordination polymerization. In another embodiment, there is also provided a method for producing a cured product, which includes polymerizing the copolymer using a radical polymerization initiator that does not contain oxygen or nitrogen atoms in its structure and is composed only of carbon and hydrogen atoms.

[0065] Coordination polymerization is a polymerization method using a coordination polymerization catalyst consisting of a transition metal compound and a co-catalyst. As the transition metal compound, transition metal compounds containing zirconium, hafnium, titanium, iron, nickel, cobalt, and palladium are preferred. In particular, for copolymerizing cyclic olefin monomers, transition metal compounds containing zirconium, titanium, nickel, iron, and palladium are preferred. The most preferred coordination polymerization catalyst is a coordination polymerization catalyst consisting of a transition metal compound represented by the following general formula (1) and a co-catalyst. More preferably, the production method may include a step of copolymerizing each of the monomers of an α-olefin, a cyclic olefin, an aromatic vinyl compound (if included), and an aromatic polyene using a polymerization catalyst consisting of a transition metal compound represented by the following general formula (1) and a co-catalyst:

[0066] General formula (1)

[0067] In the above formula, A and B are each independently a group selected from an unsubstituted or substituted cyclopentaphenanthryl group, an unsubstituted or substituted benzoindenyl group, an unsubstituted or substituted cyclopentadienyl group, and an unsubstituted or substituted indenyl group.

[0068] Y is a methylene group, silylene group, ethylene group, germylene group, or boron residue having a bond to A and B and having hydrogen or a hydrocarbon group having 1 to 15 carbon atoms (which may contain 1 to 3 nitrogen, oxygen, sulfur, phosphorus, or silicon atoms) as a substituent. The substituents may be different or the same. Y may also have a cyclic structure. Most preferably, Y is a methylene group having a bond to A and B and having hydrogen or a hydrocarbon group having 1 to 15 carbon atoms (which may contain 1 to 3 nitrogen, oxygen, sulfur, phosphorus, or silicon atoms) as a substituent.

[0069] X is hydrogen, halogen, an alkyl group having 1 to 15 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkylaryl group having 8 to 12 carbon atoms, a silyl group having a hydrocarbon substituent having 1 to 4 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a dialkylamide group having an alkyl substituent having 1 to 6 carbon atoms.

[0070] M is a transition metal, and may preferably be zirconium, hafnium, or titanium.

[0071] In order to obtain a copolymer having a relatively low molecular weight and a low viscosity when made into a varnish, preferably, A and B in the above general formula (1) may each independently be a group selected from an unsubstituted or substituted cyclopentadienyl group or an unsubstituted or substituted indenyl group, and it is particularly preferable to use a transition metal compound having both an unsubstituted or substituted cyclopentadienyl group and an unsubstituted or substituted indenyl group. In order to obtain a copolymer having a high aromatic polyene content, i.e., a copolymer having a high number of vinyl groups and / or vinylene groups derived from aromatic polyene monomer units per number average molecular weight, it is preferable to use a transition metal compound having at least one group selected from an unsubstituted or substituted indenyl group or an unsubstituted or substituted benzoindenyl group. In the case of a copolymer having a high aromatic polyene monomer unit content, it is possible to increase the crosslink density of the cured product obtained by curing, and a cured product having a storage modulus of 5 MPa or more measured at 280°C can be obtained, for example.

[0072] The cocatalyst in the polymerization catalyst of the present invention can be a known cocatalyst used in combination with a transition metal compound. Preferred examples of such cocatalysts include aluminum compounds and boron compounds. Alumoxanes such as methylaluminoxane (also referred to as methylalumoxane or MAO) are preferably used as the aluminum compound. Alternatively, alkylaluminums such as triisobutylaluminum and triethylaluminum may be used. Examples of such cocatalysts include the cocatalysts and alkylaluminum compounds described in EP 0872492A2, JP 11-130808 A, JP 9-309925 A, WO 00 / 20426 A, EP 0985689A, and JP 6-184179 A.

[0073] Examples of boron compounds (boron-containing promoters) include trispentafluorophenylborane, triphenylcarbenium tetrakis(pentafluorophenyl)borate {trityl tetrakis(pentafluorophenyl)borate}, lithium tetrakis(pentafluorophenyl)borate, trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri(n-butyl)ammonium tetraphenylborate, tri(n-butyl)ammonium tetra(p-tolyl)phenylborate, tri(n-butyl)ammonium tetra(p-ethylphenyl)borate, tri(n-butyl)ammonium tetra(pentafluorophenyl)borate, trimethylammonium tetra(p-tolyl)borate, trimethylammonium tetrakis-3,5-dimethylphenylborate, and triethylammonium tetrakis(pentafluorophenyl)borate. tetrakis-3,5-dimethylphenylborate, tributylammonium tetrakis-3,5-dimethylphenylborate, tributylammonium tetrakis-2,4-dimethylphenylborate, anilinium tetrakispentafluorophenylborate, N,N'-dimethylanilinium tetraphenylborate, N,N'-dimethylanilinium tetrakis(p-tolyl)borate, N,N'-dimethylanilinium tetrakis(m-tolyl)borate, N,N'-dimethylanilinium tetrakis(2,4-dimethylphenyl)borate, N,N'-dimethylanilinium tetrakis(3,5-dimethylphenyl)borate, N,N'-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N'-diethylanilinium tetrakis(pentafluorophenyl)borate, N,N'-2,4,5-pentamethylanilinium tetraphenylborate, N,N'-2,4,Examples of suitable tetraphenylborate include 5-pentaethylanilinium tetraphenylborate, di-(isopropyl)ammonium tetrakispentafluorophenylborate, di-cyclohexylammonium tetraphenylborate, triphenylphosphonium tetraphenylborate, tri(methylphenyl)phosphonium tetraphenylborate, tri(dimethylphenyl)phosphonium tetraphenylborate, triphenylcarbenium tetrakis(p-tolyl)borate, triphenylcarbenium tetrakis(m-tolyl)borate, triphenylcarbenium tetrakis(2,4-dimethylphenyl)borate, triphenylcarbenium tetrakis(3,5-dimethylphenyl)borate, tropylium tetrakispentafluorophenylborate, tropylium tetrakis(p-tolyl)borate, tropylium tetrakis(m-tolyl)borate, tropylium tetrakis(2,4-dimethylphenyl)borate, and tropylium tetrakis(3,5-dimethylphenyl)borate, but are not particularly limited to these. Although boron-containing cocatalysts in which the fluorine-substituted aromatic group is a phenyl group have been exemplified herein, boron-containing cocatalysts having a fused aromatic group such as a fluorine-substituted naphthyl group can also be preferably used. Among these, preferred boron-containing cocatalysts are those having boron and a fluorine-substituted aromatic group bonded thereto. Examples include, but are not limited to, trispentafluorophenylborane, triphenylcarbenium tetrakis(pentafluorophenyl)borate {trityl tetrakis(pentafluorophenyl)borate}, lithium tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium tetra(pentafluorophenyl)borate, tropylium tetrakispentafluorophenylborate, and N,N'-dimethylanilinium tetrakis(pentafluorophenyl)borate. Particularly preferred are triphenylcarbenium tetrakis(pentafluorophenyl)borate {trityl tetrakis(pentafluorophenyl)borate} and N,N'-dimethylanilinium tetrakis(pentafluorophenyl)borate is used. These most preferred boron-containing cocatalysts are also referred to as TRI-FABA or TRI-FAB, DAN-FABA or DAN-FAB, respectively, and can be purchased from Tosoh Finechem Co., Ltd. or Kanto Chemical Co., Ltd.

[0074] The co-catalyst is used in an aluminum atom / transition metal atomic ratio relative to the metal of the transition metal compound of 0.1 to 100,000, preferably 10 to 10,000. A ratio of 0.1 or more can effectively activate the transition metal compound, while a ratio of 100,000 or less is economically advantageous. The transition metal compound and co-catalyst may be mixed and prepared outside of a polymerization facility, or may be mixed inside the facility during polymerization.

[0075] In particular, the aluminum atom / transition metal atomic ratio of a promoter such as alumoxane relative to the metal of the transition metal compound is preferably 0.1 to 100,000, and more preferably 10 to 10,000. A ratio of 0.1 or more can effectively activate the transition metal compound, and a ratio of 100,000 or less is economically advantageous. When a boron compound is used as the promoter, the boron atom / transition metal atomic ratio is preferably 0.1 to 100, more preferably 0.1 to 10, and most preferably in the range of 0.8 to 1.2. A ratio of 0.1 or more can effectively activate the transition metal compound, and a ratio of 100 or less is economically advantageous.

[0076] In a preferred embodiment, a boron compound is required as a co-catalyst, and an aluminum compound may be used as needed. The use of a boron compound as a co-catalyst can reduce the amount of metal components, such as aluminum derived from the aluminum compound, contained in the final copolymer, and can reduce the dielectric constant and dielectric loss tangent of the final uncured copolymer, or the dielectric constant and dielectric loss tangent of the single cured product or composition, to particularly preferred ranges. For example, the dielectric constant of the uncured copolymer can be less than 2.3, and the dielectric loss tangent can be less than 0.0004. Furthermore, when a boron compound is used as a co-catalyst, the dielectric constant of the final cured product of the copolymer can be less than 2.3, and the dielectric loss tangent can be less than 0.0004.

[0077] In one embodiment, an uncured α-olefin-cycloolefin-aromatic polyene copolymer or α-olefin-cycloolefin-aromatic vinyl compound-aromatic polyene copolymer can be provided, having a total metal content derived from the catalyst and co-catalyst of 1500 ppm or less, preferably 1000 ppm or less, and most preferably 500 ppm or less. Here, the metal content derived from the catalyst and co-catalyst is defined as the sum of the respective contents of the transition metal elements (as described above) used in the catalyst and the boron and / or aluminum derived from the boron compound and / or aluminum compound used in the co-catalyst, and can be defined as the sum of the respective elemental contents of zirconium, hafnium, titanium, iron, nickel, palladium, cobalt, boron, and aluminum. Particularly preferably, the metal derived from the catalyst may be zirconium, and the metal derived from the co-catalyst may be aluminum and boron, and the metal content derived from the catalyst and co-catalyst may be the sum of the respective contents of zirconium, aluminum, and boron. Note that, in this specification, boron is included in the category of metal. An α-olefin-cyclic olefin-aromatic polyene copolymer or a composition comprising α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymers A and B having a total metal content of 1500 ppm or less, preferably 1000 ppm or less, and most preferably 500 ppm or less, can exhibit a dielectric constant of less than 2.5 at a measurement frequency of 40 GHz and a dielectric dissipation factor of less than 0.0006 at a measurement frequency of 40 GHz.

[0078] The present invention will be described below with reference to examples, but the present invention should not be construed as being limited to the following examples.

[0079] The copolymers obtained in the synthesis examples were analyzed by the following methods. The contents of ethylene, cyclic olefin, styrene, and ethylvinylbenzene in the copolymer, as well as the content of vinyl group units derived from divinylbenzene, were determined by the following methods: 1 H-NMR measurement and quantitative mode 13 C-NMR measurement was performed, and the determination was performed using a known method based on the area intensity of the obtained peak. The sample was dissolved in deuterated 1,1,2,2-tetrachloroethane, and the measurement was performed at 80 to 130°C.

[0080] <Molecular Weight> The molecular weight was determined as the number average molecular weight (Mn) converted to standard polystyrene using GPC (gel permeation chromatography). The measurement was carried out under the following conditions. Column: Two TSK-GEL Multipore HXL-M φ7.8 × 300 mm (manufactured by Tosoh Corporation) connected in series were used. Column temperature: 40°C Solvent: THF Flow rate: 1.0 ml / min Detector: RI detector

[0081] <Gel content> The gel content was determined as boiling toluene insoluble matter according to ASTM D2765-84.

[0082] <Dielectric Constant (Dk) and Dielectric Loss (Dielectric Loss Tangent (Df))> The dielectric loss tangent was measured using a cavity resonator perturbation method (Agilent Technologies 8722ES Network Analyzer, Keysight Technologies Split Cylinder Resonator 10, 28, 40 GHz) at 23°C and 40 GHz using a 0.2 mm x 30 mm x 40 mm sample cut out from the sheet. Measurements were performed for both the uncured state and the cured state.

[0083] <Storage modulus> Using a dynamic viscoelasticity measuring device (TA Instruments, formerly Rheometrics RSA-G2), measurements were taken at a frequency of 1 Hz while the temperature was raised from 20°C, and the storage modulus was measured at 25°C and 280°C. Measurement samples (4 mm x 35 mm) were cut out from a film approximately 0.2 mm thick and measured, and the storage modulus was measured in both the uncured and cured states. The main measurement parameters involved in the measurement were as follows: Measurement frequency: 1 Hz Heating rate: 3°C / min Sample measurement length: 10 mm Strain: 0.1%

[0084] <Production of Copolymer (A)1> The raw material divinylbenzene (DVB) was "DVB-810" (liquid at room temperature, a mixture of meta and para divinylbenzenes containing 81% by mass, with the remainder being ethylvinylbenzene) manufactured by Nippon Steel Chemical & Material Co., Ltd. Norbornene (75% concentration, toluene solution) manufactured by Maruzen Petrochemical Co., Ltd. was used as the raw material. A small amount of triisobutylaluminum (TIBA) was added beforehand, the mixture was stirred at room temperature, and then distilled and purified under nitrogen. A 10-L polymerization vessel equipped with a heating and cooling jacket and a stirrer was used. The interior of the polymerization vessel was first thoroughly dried and purged with nitrogen. 2.33 kg of toluene, 0.4 kg of styrene, 2.67 kg of pure norbornene, and 600 g of pure divinylbenzene were charged, and approximately 300 L of dry nitrogen was bubbled in at an internal temperature of 50°C. The inside of the polymerization vessel was then purged with ethylene gas, and 2.0 mmol of TIBA (manufactured by Kanto Chemical Co., Inc.) was added in an amount of 2.0 mmol (based on the number of moles of aluminum) and stirred. The inside temperature was stabilized at 90°C, and the inside pressure of the polymerization vessel was increased to 0.10 MPaG (gauge) by supplying ethylene and stabilized. Then, from a catalyst tank installed above the polymerization vessel, a catalyst solution prepared by stirring and dissolving 211 µmol of tritylium tetrakis(pentafluorophenyl)borate in 256 g of a toluene solution containing 176 µmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride (structure: see formula (2) below) as a catalyst and 2.0 mmol of triisobutylaluminum was added, to initiate polymerization. The polymerization was continued while gradually replenishing ethylene consumed in the polymerization and maintaining the internal temperature at 60°C and the internal pressure at 0.10 MPaG, and after about 1 hour of polymerization, when the amount of ethylene consumed reached 40 L, the ethylene gas in the polymerization vessel was discharged to return the pressure to normal, and 100 g of isopropanol as a polymerization terminator was added to the polymerization vessel to terminate the polymerization. The resulting polymerization liquid was concentrated under reduced pressure to obtain an ethylene-styrene-norbornene-divinylbenzene copolymer (A)1.

[0085] Formula (2)

[0086] <Production of Copolymer (A)2> Polymerization was carried out in the same manner as in the synthesis of (A)1, except that the amounts of raw materials were changed to 2.0 kg of toluene, 0 kg of styrene, and 2.0 kg of norbornene in terms of pure content, and the catalyst solution was changed to one obtained by dissolving 103 μmol of tritylium tetrakis(pentafluorophenyl)borate in 125 g of a toluene solution containing 86 μmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride and 1.0 mmol of triisobutylaluminum with stirring, and the polymerization was terminated when the amount of ethylene consumed reached 80 L, thereby obtaining Copolymer (A)2.

[0087] <Production of Copolymer (A)3> Polymerization was carried out in the same manner as in the synthesis of (A)1, except that the internal temperature was 80°C, the amounts of raw materials used were changed to 2.0 kg of toluene, 0.65 kg of styrene, and 1.00 kg of divinylbenzene, and the amount of norbornene used was changed to 2.0 kg in terms of pure content, and the catalyst solution was changed from dimethylmethylenebis(cyclopentadienyl)zirconium dichloride to 824 μmol of rac-diphenylmethylene(1-indenyl)(cyclopentadienyl)zirconium dichloride (structure: see formula (3) below) and 990 μmol of tritylium tetrakis(pentafluorophenyl)borate dissolved with stirring in 340 g of a toluene solution containing 87 mmol of triisobutylaluminum, and the ethylene was changed to a hydrogen / ethylene mixed gas containing 4% hydrogen by volume. The polymerization was terminated when the consumption amount reached 65 L, thereby obtaining copolymer (A)3.

[0088]

[0089] <Production of Copolymer (B)1> Polymerization was carried out in the same manner as in the synthesis of (a)1, except that the internal temperature was 60°C, the amounts of the raw materials were changed to 2.30 kg of toluene, 2.00 kg of styrene, 0.50 kg of norbornene in pure content, and 600 g of divinylbenzene in pure content, and the catalyst solution was changed to 144 g of a toluene solution containing 99 μmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride and 1.2 mmol of triisobutylaluminum, and 119 μmol of tritylium tetrakis(pentafluorophenyl)borate dissolved with stirring, and the polymerization was terminated when the amount of ethylene consumed reached 200 L, thereby obtaining Copolymer (B)1.

[0090] <Production of Copolymer (B)2> Polymerization was carried out in the same manner as in the synthesis of (B)1, except that the amounts of the materials used were changed to 1.50 kg of toluene, 3.00 kg of styrene, 0.30 kg of norbornene in pure content, 600 g of divinylbenzene in pure content, and 177 g of a toluene solution containing 121 μmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride and 1.4 mmol of TIBA. The polymerization was terminated when the amount of ethylene consumed reached 200 L, thereby obtaining an ethylene-styrene-norbornene-divinylbenzene copolymer (B)2.

[0091] <Production of Copolymer (B)3> Polymerization was carried out in the same manner as in the synthesis of (B)1, except that the amounts of the raw materials were changed to 2.50 kg of toluene, 2.00 kg of styrene, 0.30 kg of norbornene in pure content, and 600 g of divinylbenzene in pure content, and further the catalyst used was changed to 108 g of a toluene solution containing 74 μmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride and 0.87 mmol of TIBA. The polymerization was terminated when the amount of ethylene consumed reached 200 L, thereby obtaining an ethylene-styrene-norbornene-divinylbenzene copolymer (B)3.

[0092] <Production of Copolymer (B)4> Polymerization was carried out in the same manner as in the synthesis of (B)1, except that the amounts of raw materials were changed to 3.00 kg of toluene, 2.30 kg of styrene, no norbornene was added, and the amounts of divinylbenzene were changed to 350 g in terms of pure content, 169 μmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride, and 246 g of a toluene solution containing 2.0 mmol of TIBA. The polymerization was terminated when the amount of ethylene consumed reached 400 L, thereby obtaining an ethylene-styrene-divinylbenzene copolymer (B)4.

[0093] <Production of Copolymer (B)5> Polymerization was carried out in the same manner as in the synthesis of (B)1, except that the internal temperature was 90°C, and the amounts of the raw materials used were 3.75 kg of toluene, 1.60 kg of styrene, 0.15 kg of norbornene in pure content, 200 g of divinylbenzene in pure content, and 48.5 μmol of rac diphenylmethylene(1-indenyl)(cyclopentadienyl)zirconium dichloride in place of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride, and the catalyst solution was changed to one in which 58.2 μmol of tritylium tetrakis(pentafluorophenyl)borate was dissolved with stirring in 20 g of a toluene solution containing 5.11 mmol of TIBA. The polymerization was terminated when the amount of ethylene consumed reached 150 L, yielding an ethylene-styrene-norbornene-divinylbenzene copolymer (B)5.

[0094] <Production of Copolymer (B)6> Polymerization was carried out in the same manner as in the synthesis of (B)1, except that the amounts of raw materials used were changed to a catalyst solution obtained by dissolving 193 μmol of tritylium tetrakis(pentafluorophenyl)borate with stirring in 234 g of a toluene solution containing 2.58 kg of toluene, 2.00 kg of styrene, 0.225 kg of norbornene in pure content, 600 g of divinylbenzene in pure content, 160 μmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride, and 10.7 mmol of TIBA, and the polymerization was terminated when the amount of ethylene consumed reached 200 L, thereby obtaining an ethylene-styrene-norbornene-divinylbenzene copolymer (B)6.

[0095] <Production of Copolymer (B)7> Polymerization was carried out in the same manner as in the synthesis of (B)1, except that the amounts of raw materials used were changed to 3.00 kg of toluene, 2.30 kg of styrene, and no norbornene was added. Polymerization was carried out using a catalyst solution prepared by dissolving 203 μmol of N,N′-dimethylanilinium tetrakis(pentafluorophenyl)borate in 246 g of a toluene solution containing 350 g of pure divinylbenzene, 169 μmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride, and 2.0 mmol of TIBA, with stirring. The polymerization was terminated when the amount of ethylene consumed reached 400 L, yielding an ethylene-styrene-divinylbenzene copolymer (B)7.

[0096] The obtained copolymers (A) 1 to 3 and copolymers (B) 1 to 7 contained small amounts of residual monomers and solvents, so they were redissolved in toluene, and the solution was gradually poured into a sufficiently large amount of a methanol / acetone mixed solution. The precipitated polymer was stirred, filtered, and dried at room temperature under vacuum for 24 hours to obtain a purified polymer. The composition and molecular weight of the obtained copolymers are shown in Table 1. Using this purified polymer, DSC was measured to determine the glass transition temperature, and GPC was measured to determine the number average molecular weight. The composition of the copolymers was also measured. 1 The results are shown in Table 1.

[0097]

[0098] Example 1: Preparation of a Cured Copolymer Composition Sheet Using a vial and a magnetic stirrer, 70 parts by weight of (A) 1 (ethylene-styrene-norbornene-divinylbenzene copolymer) and 30 parts by weight of (B) 1 (ethylene-styrene-norbornene-divinylbenzene copolymer) were stirred in 100 parts by weight of toluene to dissolve the copolymer and prepare a 50% by weight toluene solution (varnish). Furthermore, 0.75 parts by weight of a curing agent (2,2-azobis-2,4,4-trimethylpentane, manufactured by Wako Pure Chemical Industries, Ltd., "VR-110") was added and dissolved relative to the parts by weight of the copolymer, followed by stirring and mixing to obtain a varnish-like composition (Table 2). To confirm compatibility, the composition was left to stand for 3 minutes, and the appearance was checked. Compatibility was evaluated as follows: transparent or non-transparent but homogeneous liquid (excellent handleability) was indicated by a ◎; small amounts of insoluble matter were present but a homogeneous cured product could be prepared (◯); and the liquid separated into two layers (×).

[0099] The resulting composition was poured into a Teflon® mold (frame length 7 cm, width 7 cm, thickness 0.2 mm, 0.5 mm, or 1.0 mm) on a PET sheet placed on a glass plate, thoroughly air-dried at 25°C, and then further dried in a vacuum dryer at 60°C for 3 hours or more to obtain an uncured sheet. The Teflon sheet and Teflon mold were then placed in a press under a load of 10 MPa and heat-treated at 200°C for 120 minutes. The Teflon sheet and Teflon mold were then removed to obtain a cured sheet. DSC of the resulting uncured sheet was measured to determine the glass transition temperatures Tg1 and Tg2. The gel fraction, storage modulus (25°C, 280°C), dielectric constant, dielectric dissipation factor (both measured at 23°C and 40 GHz), and linear expansion coefficient from 0°C to 150°C of the resulting cured sheet were also determined.

[0100] Examples 2 to 18: Preparation of cured sheets Compatibility was evaluated, cured sheets were obtained, and physical properties were determined in the same manner as in Example 1, except that the type and blending ratio of the copolymers were changed.

[0101] Examples 19 to 24: Preparation of cured sheets Compatibility was evaluated, cured sheets were obtained, and physical properties were determined in the same manner as in Example 1, except that the type and blending ratio of the copolymer were changed and the polymerization initiator was changed to Perbutyl (registered trademark) P (manufactured by NOF Corporation).

[0102] Table 2 shows the formulations (units in the table are parts by mass) and physical properties (gel content, storage modulus at 25°C and 280°C, dielectric constant, dielectric dissipation factor, and coefficient of linear expansion). The cured sheets obtained in the examples exhibited high gel content and were sufficiently cured. The storage modulus at 25°C and 280°C provided sufficient hardness for use as a substrate, particularly a rigid substrate. Furthermore, they exhibited low dielectric constants and low dielectric dissipation factors required for high-frequency insulating materials.

[0103] Comparative Examples 1 to 13: Preparation of Cured Sheets Using the copolymers (A) and (B) shown in Table 2, compatibility was evaluated, cured sheets were obtained, and physical properties were determined in the same manner as in the Examples. However, in Comparative Example 8, SA9000 was used instead of copolymer (A). For some of the Comparative Examples, Df (40 GHz / 10 GHz) was also determined. The results are shown in Table 3.

[0104] Comparative Example 14: Frequency Dependence of Dielectric Measurement of COP (Cyclic Olefin Polymer) Using a COP (cyclic olefin polymer) test sample attached to a split cylinder resonator manufactured by Keysight Technologies, the dielectric constant and dielectric dissipation factor were measured in an uncured state at 10 GHz, 23°C and 40 GHz, 23°C, respectively, to determine Df (40 GHz / 10 GHz). The measured values ​​were as follows: Dk (10 GHz): 2.4 Dk (40 GHz): 2.3 Df (10 GHz) 0.00037 Df (40 GHz) 0.00044 COP (cyclic olefin polymer) is a thermoplastic resin obtained by ring-opening metathesis polymerization of various cyclic olefin monomers and hydrogenation of double bond moieties, and is generally known to have excellent low dielectric properties. However, it has a different composition from the α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer according to the present invention.

[0105]

[0106]

[0107]

[0108]

Claims

1. A copolymer composition comprising an α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (A) satisfying all of the following conditions (i) to (vii): (i) a number average molecular weight of 500 or more and 30,000 or less; (ii) a glass transition temperature measured by DSC of 150°C or more and 250°C or less; (iii) the α-olefin monomer is an α-olefin having 2 to 20 carbon atoms, and the content of its monomer units is 0% by mass or more and less than 10% by mass; (iv) the aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of its monomer units is 0% by mass or more and less than 20% by mass; (v) the cyclic olefin monomer is a cyclic olefin having 7 to 30 carbon atoms, and the content of its monomer units is 60% by mass or more and less than 90% by mass. (vi) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms and having a plurality of vinyl groups and / or vinylene groups in the molecule, and the content of vinyl groups and / or vinylene groups derived from the aromatic polyene units contained in the copolymer is 2 or more per number-average molecular weight, and the number-average molecular weight per vinyl group and / or vinylene group derived from the aromatic polyene monomer units is 250 to 10,000. (vii) The total content (mass %) of each monomer unit of an α-olefin, a cyclic olefin, an aromatic vinyl compound, and an aromatic polyene is 100 mass %. An α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer (B) that satisfies all of the following conditions (a) to (g): (a) the number-average molecular weight is 500 to 30,000. (b) the glass transition temperature measured by DSC is -30°C to 35°C. (c) The α-olefin monomer is an α-olefin having 2 to 20 carbon atoms, and the content of its monomer units is 15% by mass or more and less than 40% by mass. (d) The aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of its monomer units is 25% by mass or more and less than 50% by mass. (e) The cyclic olefin monomer is a cyclic olefin having 7 to 30 carbon atoms, and the content of its monomer units is 10% by mass or more and less than 50% by mass.(f) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms and having a plurality of vinyl groups and / or vinylene groups in the molecule, the content of vinyl groups and / or vinylene groups derived from aromatic polyene units contained in the copolymer is 2 or more per number average molecular weight, and the number average molecular weight per vinyl group and / or vinylene group derived from aromatic polyene monomer unit is 250 or more and 10,000 or less. (g) The total content (mass %) of each monomer unit of α-olefin, cyclic olefin, aromatic vinyl compound, and aromatic polyene is 100 mass %, and the mass ratio B / A thereof is in the range of 0.11 or more and 9.00 or less.

2. A compatibilized α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymer composition having a glass transition temperature in the ranges of at least -30 to 35°C and 150 to 250°C, and satisfying all of the following (1) to (4): (1) The α-olefin unit is an α-olefin having 2 to 20 carbon atoms. (2) The aromatic vinyl compound unit is an aromatic vinyl compound having 8 to 20 carbon atoms. (3) The cyclic olefin unit is a cyclic olefin monomer unit having 7 to 30 carbon atoms. (4) The aromatic polyene unit is one or more polyenes selected from polyenes having 5 to 20 carbon atoms and having multiple vinyl groups and / or vinylene groups in the molecule.

3. The copolymer composition according to claim 2, having a number average molecular weight in the range of 500 to 30,000.

4. The copolymer composition according to claim 2 or 3, wherein the content of α-olefin monomer units is 1% by mass or more and 25% by mass or less, the content of aromatic vinyl compound monomer units is 5% by mass or more and less than 30% by mass, and the content of cyclic olefin monomer units is 30% by mass or more and less than 75% by mass.

5. A copolymer composition according to claim 2 or 3, wherein the content of vinyl groups and / or vinylene groups derived from aromatic polyene units contained in the copolymer is 2 or more per number average molecular weight, and the number average molecular weight per vinyl group and / or vinylene group derived from aromatic polyene monomer unit is 250 or more and 10,000 or less.

6. A cured product of the copolymer composition according to claim 1 or 2.

7. The cured product according to claim 6, which has a dielectric constant of 2.0 or more but less than 2.5 and a dielectric loss tangent of 0.0002 or more but less than 0.0010, measured at 23°C and 40 GHz.

8. The cured product according to claim 6, wherein the value of Df(40 GHz / 10 GHz), which is the ratio of the dielectric loss tangent measured at 23°C and 40 GHz to the dielectric loss tangent measured at 23°C and 10 GHz by the cavity resonator perturbation method (split cylinder resonator method), is 1.40 or less.

9. The cured product according to claim 6, having a coefficient of linear expansion (CTE) from 0°C to 150°C of 150 ppm / K or less.

10. The cured product according to claim 6, having a storage modulus (E') at 25°C of 0.5 GPa or more and a storage modulus (E') at 280°C of 2.0 MPa or more.

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