Organic bridging particles

Abstract

To provide an organic crosslinked particle excellent in low dielectric characteristics.SOLUTION: An organic crosslinked particle comprising an olefin-aromatic vinyl compound-aromatic polyene copolymer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to organic crosslinked particles containing an olefin-aromatic vinyl compound-aromatic polyene copolymer and compositions containing the same. [Background technology]

[0002] As communication frequencies shift to the gigahertz band and especially the millimeter-wave band above 30 gigahertz, the low dielectric properties required for insulators used in multilayer substrates made of CCL (copper-clad laminate), FCCL (flexible copper-clad laminate), and RCC (resin-coated copper) are becoming increasingly stringent and demanding. With Moore's Law approaching its limits due to the increasing density of wiring, in addition to the increased density of wiring in conventional semiconductor devices, there is a demand for high integration (chipletization) through three-dimensional mounting and functional coupling between elemental devices. In this context, as wiring in devices becomes multilayer, miniaturized, and denser, materials with particularly low dielectric constant and low dielectric loss tangent are required for substrates and insulating materials to prevent delays and noise generation of high-frequency signals. Fluorine-based resins such as perfluoroethylene have excellent low dielectric constant, low dielectric loss, and heat resistance, but they are difficult to mold and form into films, and there are also issues with adhesion to copper foil wiring, making them difficult to apply to multilayer substrates. On the other hand, substrates and insulating materials using post-curing 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. However, their dielectric constant and dielectric loss are relatively high, and improvements are desired for insulating materials used at high frequencies.

[0003] Therefore, attention is being drawn to hydrocarbon resins that inherently possess low dielectric properties. In order to make hydrocarbon resins, which are originally thermoplastic resins, into curable resins, it is necessary to introduce functional groups. However, functional groups that react to radicals or heat generally have polarity, which worsens the low dielectric properties. When attempting to introduce functional groups composed solely of hydrocarbons, such as aromatic vinyl groups, it is often not economical as it requires the use of intermolecular reactions between expensive hydrocarbon monomers. Patent Document 1 shows a cured product containing an ethylene-aromatic vinyl compound-aromatic polyene copolymer obtained from a specific coordination polymerization catalyst and having a specific composition and formulation. In the technology disclosed herein, only one of the two vinyl groups of the aromatic polyene (divinylbenzene) is selectively copolymerized, and the remaining vinyl group is preserved, so a crosslinkable hydrocarbon copolymer macromonomer having an aromatic vinyl functional group can be easily obtained. Cured products obtained from similar olefin-aromatic vinyl compound-aromatic polyene copolymers and compositions with auxiliary raw materials have the characteristics of low dielectric constant and low dielectric loss tangent (Patent Document 2). Relatively low viscosity varnishes comprising a relatively low molecular weight olefin-aromatic vinyl compound-aromatic polyene copolymer, an additive resin, a monomer, and a solvent are also known (Patent Document 3). Liquid curable resin compositions comprising an olefin-aromatic vinyl compound-aromatic polyene copolymer and a nonpolar vinyl compound are also known (Patent Document 4). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2009-161743 [Patent Document 2] International Publication No. 2021 / 112087 [Patent Document 3] International Publication No. 2022 / 014599 [Patent Document 4] International Publication No. 2024 / 014436 [Overview of the project] [Problems that the invention aims to solve]

[0005] Cured products obtained from olefin-aromatic vinyl compound-aromatic polyene copolymers and compositions containing the same and a hard component having a curable functional group, as described in the above-mentioned published patent documents, all exhibit good low dielectric properties, such as a low dielectric loss tangent value. However, the hard component having a curable functional group (e.g., polyphenylene ether, bismaleimides, aromatic polyene resins, etc.), which is present in considerable amounts, does not have sufficient low dielectric performance, and there is room for improvement from the viewpoint of the low dielectric performance of the cured product.

[0006] The present invention was completed in view of the above-mentioned problems, and in one embodiment, aims to provide organic crosslinked particles with excellent low dielectric properties. In another embodiment, the present invention aims to provide a composition containing such organic crosslinked particles and a curable resin, and a cured product of the composition. [Means for solving the problem]

[0007] As a result of diligent research by the inventors of the present invention, it has been found that organic crosslinked particles containing an olefin-aromatic vinyl compound-aromatic polyene copolymer and having a specific particle size range can solve the problems that the above-mentioned conventional technologies could not solve. The present invention can therefore provide the following embodiments.

[0008] [Aspect 1] Organic crosslinked particles containing an olefin-aromatic vinyl compound-aromatic polyene copolymer. [Aspect 2] Organic crosslinked particles according to embodiment 1, wherein the median diameter D50 is in the range of 0.1 to 5.0 μm. [Aspect 3] The organic crosslinked particles according to embodiment 1 further include polyfunctional monomers. [Aspect 4] I(3025cm) measured by IR -1 :Aromatic CH expansion / contraction) / I(2920cm -1 Organic crosslinked particles according to embodiment 1, wherein the aliphatic CH stretching ratio is 0.10 or more and 1.20 or less. [Aspect 5] The organic crosslinked particles according to Aspect 1, wherein the gel content is 80% by mass or more. [Aspect 6] The organic crosslinked particles according to Aspect 1, wherein the glass transition temperature (Tg) measured by DSC method is 100°C or higher and 350°C or lower. [Aspect 7] The organic crosslinked particles according to Aspect 1, wherein the olefin-aromatic vinyl compound-aromatic polyene copolymer satisfies all of the following (1) to (5). (1) The number average molecular weight of the copolymer is 500 or more and 50000 or less. (2) The aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of the aromatic vinyl compound monomer unit is 0.1% by mass or more and 70% by mass or less. (3) The olefin monomer unit is one or more selected from α-olefin monomer units having 2 to 30 carbon atoms and cyclic olefin monomer units having 7 to 30 carbon atoms, and the content thereof is 5% by mass or more and 95% by mass or less. (4) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms that have 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 monomer unit is 2 or more and 30 or less per number average molecular weight. (5) The total of the olefin monomer unit, the aromatic vinyl compound monomer unit, and the aromatic polyene monomer unit is 100% by mass. [Aspect 8] The organic crosslinked particles according to Aspect 1, wherein the olefin is an olefin-aromatic vinyl compound-aromatic polyene copolymer containing at least a cyclic olefin component. [Aspect 9] The organic crosslinked particles according to Aspect 1, wherein the olefin-aromatic vinyl compound-aromatic polyene copolymer has a dielectric constant of 2.5 or less and a dielectric loss tangent of 0.0010 or less, measured at 10 GHz and 23°C. [Aspect 10] A method for producing organic crosslinked particles according to any one of embodiments 1 to 9, wherein polymerization is carried out by emulsion polymerization using the olefin-aromatic vinyl compound-aromatic polyene copolymer and a polyfunctional monomer. [Aspect 11] A composition comprising organic crosslinked particles as described in any one of embodiments 1 to 9. [Aspect 12] Furthermore, the composition according to embodiment 11, further comprising a curable resin. [Aspect 13] The composition according to embodiment 11, wherein the curable resin is one or more selected from olefin-aromatic vinyl compound-aromatic polyene copolymers, hydrocarbon elastomers, polyether resins having multiple functional groups in one molecule including polyphenylene ether, and aromatic polyene resins. [Aspect 14] A cured body of the composition described in embodiment 11. [Aspect 15] A cured body according to embodiment 14, which is in the form of a sheet. [Aspect 16] The cured body according to embodiment 14, wherein the coefficient of linear expansion (CTE) at 0°C to 200°C is 150 ppm or less. [Aspect 17] CCL, FCCL, interlayer insulating material, or RCC containing organic crosslinked particles as described in any one of embodiments 1 to 9. [Aspect 18] A CCL, FCCL, interlayer insulating material, or RCC comprising the cured body described in Embodiment 14. [Effects of the Invention]

[0009] According to the present invention, organic crosslinked particles with excellent low dielectric properties can be provided. A cured product of a composition containing these crosslinked particles can also exhibit excellent low dielectric properties.

[0010] The cured body obtained by the present invention is useful as an insulating component for single-layer or multi-layer CCL, FCCL, RCC, interlayer insulating materials and packages, and further as an insulating material for multi-layer, miniaturized, and high-density high-frequency transmission wiring such as chiplets, various three-dimensional mounting substrates, redistribution layers, and interposers. [Brief explanation of the drawing]

[0011] [Figure 1] This is a TEM (transmission electron microscope) image of organic crosslinked particles 1 obtained in Example 1. [Modes for carrying out the invention]

[0012] Next, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and it should be understood that appropriate design changes, improvements, etc., can be made based on the ordinary knowledge of those skilled in the art, without departing from the spirit of the invention.

[0013] In one embodiment, the present invention provides organic crosslinked particles comprising an olefin-aromatic vinyl compound-aromatic polyene copolymer and having an average particle diameter d50 in the range of 0.1 to 5.0 μm. Furthermore, in another embodiment, the present invention provides organic crosslinked particles comprising at least an olefin-aromatic vinyl compound-aromatic polyene copolymer and a polyfunctional monomer.

[0014] The olefin-aromatic vinyl compound-aromatic polyene copolymer used in the present invention can be obtained by copolymerizing monomers of olefin, aromatic vinyl compound and aromatic polyene. The copolymerization may be either statistical copolymerization or block copolymerization, and is preferably statistical copolymerization. The presence of the olefin-aromatic vinyl compound-aromatic polyene copolymer in the organic crosslinked particles can be confirmed by infrared spectroscopy (IR), Raman spectroscopy, pyrolysis gas chromatography, or solid-state NMR. The average particle diameter of the organic crosslinked particles containing the copolymer is represented by the particle diameter (median diameter, d50) at which the cumulative value of the volume-based cumulative particle size distribution reaches 50%, and is preferably in the range of 0.1 to 5.0 µm, more preferably in the range of 0.3 to 3.5 µm. By setting the average particle diameter of the organic crosslinked particles within the above range, the dielectric properties and expansion coefficient of the finally obtained cured product can be improved. The shape of the organic crosslinked particles is not particularly limited, but is preferably spherical. In the present specification, organic crosslinked particles are treated as spherical if the minimum diameter is within -20% of the maximum diameter in three dimensions.

[0015] As an index indicating the proportion of the aromatic polyene component contained in the organic crosslinked particles of the present invention, the following IR measurement is used. I obtained by IR measurement of organic crosslinked particles ap value = I(3025cm -1 : aromatic C-H stretching) / I(2920cm -1 : aliphatic C-H stretching) is 0.10 or more and 1.20 or less, preferably 0.15 or more and 1.00 or less. Here, I(3025cm -1 : aromatic C-H stretching) refers to that at 3025cm -1 it is the absorption peak intensity related to aromatic C-H stretching vibration appearing near, and I(2920cm -1 : aliphatic C-H stretching) refers to that at 2920cm -1 it is the absorption peak intensity related to aliphatic C-H stretching vibration appearing near. These peak intensities are obtained by using a tangent line connecting the lower parts of the peaks on the closest high wavenumber side and low wavenumber side of the peak as the baseline, and calculating the difference in absorbance between the baseline and the peak top. The I ap A higher value indicates that the proportion of the aromatic polyene component contained in the organic crosslinked particles is higher.

[0016] Another indicator of the proportion of aromatic polyene components contained in the organic crosslinked particles of the present invention is the glass transition temperature. The glass transition temperature of the organic crosslinked particles themselves can be determined by the DSC (Differential Scanning Calorimeter) method. Since it is often difficult to form sheets of organic crosslinked particles on their own, it is preferable to determine the glass transition temperature by the DSC method rather than the DMA (Dynamic Dynamic Measurement) method. This glass transition temperature is the intermediate glass transition temperature determined in the 2nd Run. The glass transition temperature (Tg) of the organic crosslinked particles is preferably 100°C to 350°C. It is noteworthy that the olefin-aromatic vinyl compound-aromatic polyene copolymer used itself does not contain cyclic olefin components, and therefore even if the glass transition temperature (Tg obtained by DMA in this case) is as low as -10°C, the organic crosslinked particles of the present invention can exhibit a glass transition temperature (DSC) of 100°C or higher. In the production of organic crosslinked particles, using a polyfunctional monomer can give a higher glass transition temperature than a cured product of the olefin-aromatic vinyl compound-aromatic polyene copolymer alone.

[0017] The gel content of the organic crosslinked particles is preferably 80% by mass or more, more preferably 90% by mass or more. This gel content is a value obtained by measurement in accordance with JIS K6796:1998, or by measurement in accordance with ASTM D2765-84, which corresponds to ISO 10147:1994, which is the equivalent of JIS.

[0018] The olefin-aromatic vinyl compound-aromatic polyene copolymer used in the present invention may preferably satisfy all of the following (1) to (5). (1) The number-average molecular weight of the copolymer is between 500 and 50,000. (2) The aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of the aromatic vinyl compound monomer is 0.1% by mass or more and 70% by mass or less. (3) The olefin monomer unit is one or more selected from α-olefin monomer units having 2 to 30 carbon atoms and cyclic olefin monomer units having 7 to 30 carbon atoms, and its content is 5% by mass or more and 95% by mass or less. (4) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms and having multiple vinyl and / or vinylene groups in the molecule, and the content of vinyl and / or vinylene groups derived from the aromatic polyene monomer unit is 2 to 30 per number average molecular weight. (5) The total of olefin monomer units, aromatic vinyl compound monomer units, and aromatic polyene monomer units is 100% by mass.

[0019] In the present invention, it is preferable that the copolymer is an olefin-aromatic vinyl compound-aromatic polyene copolymer containing at least cyclic olefin monomer units as olefin monomer units. By including cyclic olefins in the copolymer, the dielectric constant and dielectric loss tangent of the organic crosslinked particles themselves and the cured product containing them can be kept below a certain value. Furthermore, by including cyclic olefin monomer units in the copolymer, the coefficient of thermal expansion (CTE) of the organic crosslinked particles themselves and the cured product containing them can be reduced compared to the case where cyclic olefins are not included.

[0020] Here, an olefin monomer (referring to a monomer that forms the basis of an olefin monomer unit in a copolymer; however, in this specification, monomer and monomer unit (or unit) may be used interchangeably depending on the context; the same applies to similar terms below) is one or more selected from α-olefin monomers having 2 to 20 carbon atoms and cyclic olefin monomers having 7 to 30 carbon atoms. Examples of α-olefin monomers having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 3,5,5-trimethyl-1-hexene, preferably a combination of ethylene and an α-olefin other than ethylene, most preferably ethylene. In the copolymer, the content of α-olefin monomer units is arbitrary, but preferably 0% by mass or more and 70% by mass or less, more preferably more than 0% by mass and 60% by mass or less, and even more preferably 1% by mass or more and 60% by mass or less. A higher α-olefin monomer unit content (for example, 5% by mass or more) is preferable because it makes it easier to avoid brittleness in the copolymer and its cured product.

[0021] In this specification, a cyclic olefin monomer refers to a cyclic olefin having 7 to 30 carbon atoms. A cyclic olefin having 7 to 30 carbon atoms is a cyclic olefin having one or more alicyclic structures in its molecule and polymerizable vinyl groups, vinylene groups, or vinylidene groups. Preferred cyclic olefins are those having a hydrocarbon ring structure without heteroatoms, and more preferably cyclic olefins having an unsaturated hydrocarbon ring. Such cyclic olefins have the remarkable characteristics of low dielectric properties and high glass transition temperatures, while being easier to prepare with inexpensive raw materials and simple processes compared to conventional engineering plastics.

[0022] Examples of such cyclic olefins include norbornenes and acenaphthylenes. Norbornenes are monomers selected from norbornene and substituted norbornenes. Norbornene can be synthesized, for example, by the Diels-Alder reaction of ethylene and cyclopentadiene. Substituted norbornenes are substituted norbornenes having polymerizable vinyl groups, vinylene groups, or vinylidene groups in their molecules, and examples include dimetanooctahydronaphthalene (DMON) and trimetanododecahydroanthracene (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 cyclic olefins having a larger number of ring structures and a higher molecular weight, such as dimetanooctahydronaphthalene (DMON) and trimetanododecahydroanthracene (TMDA). Copolymerizing such cyclic olefins yields copolymers with higher glass transition temperatures (Tg) at lower molar percentages of monomer units. This makes it possible to increase the molar percentage content of other monomer units while maintaining the high glass transition temperature of the copolymer. Increasing the molar percentage content of aromatic vinyl compound monomer units as other monomer units enhances the aromatic properties of the copolymer as a whole, which is preferable as it improves compatibility with other raw materials and resins of the copolymer. These high molecular weight cyclic olefins may be used alone or copolymerized as a mixture with norbornene or the like.

[0023] In particular, DMON and TMDA mentioned above may be obtained as a mixture with norbornene when produced by Diels-Alder Reaction, and it is possible to reduce production costs by using the mixture as is in polymerization. Furthermore, in the present invention, a more preferred cyclic olefin is norbornene having an aromatic substituent, and examples 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. Norbornene having such aromatic substituents can impart a higher glass transition temperature (Tg) to the copolymer when copolymerized, and further exhibit aromaticity, thus demonstrating high compatibility with other aromatic raw materials (crosslinkable soft resins and flame retardants). Moreover, using methylphenylnorbornene (5-methyl-5-phenylbicyclo[2.2.1]hept-2-ene) is preferable because it can improve the heat oxidation resistance of the resulting copolymer, as described in Japanese Patent Publication No. 2005-239975. These norbornene having aromatic substituents are specifically described in, for example, Japanese Patent Publication No. 11-504669 and Japanese Patent Publication No. 2005-239975.

[0024] The content of cyclic olefin monomer units in the copolymer is arbitrary, but when aiming for a high glass transition temperature (Tg) of the copolymer, the optimal content of cyclic olefin monomer units in the copolymer varies depending on the type of cyclic olefin, but for example, it is 50% by mass or more and 95% by mass or less, preferably 60% by mass or more and 95% by mass or less, more preferably 70% by mass or more and 95% by mass or less, and most preferably 80% by mass or more and 95% by mass or less. The higher the content of cyclic olefin monomer units, the higher the Tg of the copolymer. From the viewpoint of imparting a certain degree of toughness to the copolymer, the optimal content of cyclic olefin units in the copolymer may be less than 90% by mass. Having a content within these ranges makes it easier to achieve a desirable high glass transition temperature of the copolymer. The preferred glass transition temperature of the copolymer is 100°C or more and 350°C or less, more preferably 130°C or more and 300°C or less, and most preferably 180°C or more and 300°C or less. On the other hand, when the content of cyclic olefin monomer units is in the range of 10% by mass or more and less than 50% by mass, a copolymer with a relatively low Tg can be obtained. In particular, for copolymers that are soft at room temperature, the content of cyclic olefin monomer units is in the range of 10% by mass or more and less than 40% by mass. Copolymerization of cyclic olefin monomer units is preferable because it yields a lower dielectric constant and especially a lower dielectric loss tangent in the copolymer itself and its cured product compared to copolymers that do not contain cyclic olefin monomer units.

[0025] In preferred embodiments, 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 norbornene other than methylphenylnorbornene, and dimethanooctahydronaphthalene, and more preferably, monomer units derived from one or more selected from the group consisting of norbornene, methylphenylnorbornene, and dimethanooctahydronaphthalene.

[0026] The aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and examples include styrene, paramethylstyrene, ethyl vinylbenzene, para-isobutylstyrene, various vinylnaphthalenes, and various vinylanthracenes. The aromatic vinyl compound monomer of this embodiment has at least one vinyl group or vinylene group within the monomer. Monomer units derived from aromatic vinyl compounds may also be included in the copolymer as a result of copolymerization of aromatic vinyl compound components included as impurities in the aromatic polyene used in polymerization. The content of aromatic vinyl compound monomer units in the copolymer is arbitrary, but preferably 0.1% by mass or more and 70% by mass or less, more preferably 1% by mass or more and 60% by mass or less.

[0027] When the content of aromatic vinyl compound monomer units is 10% by mass or more, it is possible to improve the aromaticity of the copolymer, which improves compatibility with other resin materials, flame retardants, and fillers, suppresses bleed-out of flame retardants, and facilitates high-filling of fillers, making it preferable. As described above, the glass transition temperature and aromaticity of the copolymer can be adjusted by the content of cyclic olefin monomer units and aromatic vinyl compound monomer units in the copolymer.

[0028] The aromatic polyene monomer is a polyene having 5 to 20 carbon atoms and having 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 having multiple vinyl groups in its molecule, and more preferably a compound having an aromatic vinyl structure such as ortho, meta, or para divinylbenzene or mixtures thereof, divinylnaphthalene, divinylanthracene, p-2-propenylstyrene, or p-3-butenylstyrene, which is substantially free of oxygen, nitrogen, and halogens and composed of carbon and hydrogen. Alternatively, a bifunctional aromatic vinyl compound described in Japanese Patent Application Publication No. 2004-087639, such as 1,2-bis(vinylphenyl)ethane (abbreviated as BVPE), can also be used. Among these, ortho, meta, or para divinylbenzene or mixtures thereof are preferably used, and most preferably a mixture of meta and para-divinylbenzene is 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 the curing process, making curing easier.

[0029] The number-average molecular weight of the copolymer of the present invention is preferably 500 to 50,000, more preferably 500 to 30,000 or 500 to less than 30,000, even more preferably 500 to 15,000 or 500 to less than 15,000, and still more preferably 500 to 12,000 or 500 to less than 12,000. When the number-average molecular weight is 500 or more, the mechanical properties of the composition in the uncured stage are enhanced, and the tackiness becomes appropriate, resulting in the effect of facilitating molding as a thermoplastic resin. When the number-average molecular weight is 30,000 or less, the moldability is improved. In particular, when the number-average molecular weight is 30,000 or less, or 12,000 or less, it is advantageous because it allows the viscosity of the varnish containing this copolymer to be kept below a certain value. When the viscosity of the varnish is lower than a certain value, the workability is improved, and it becomes easier to impregnate glass fibers and the like with the varnish, improving the embedding ability in semiconductor devices with uneven surfaces.

[0030] In the copolymer of the present invention, the content of vinyl groups and / or vinylene groups derived from 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 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 collectively refer to as "vinyl group content" below. Since vinyl groups are superior to vinylene groups in terms of crosslinking efficiency, in the present invention, the content of vinyl groups (in this case, not including vinylene groups) derived from aromatic polyene monomer units is preferably 2 to 30, preferably 3 to 20, per number average molecular weight. When the vinyl group content is 2 or more, the crosslinking efficiency is high and a cured product with sufficient crosslinking density can be obtained. As the vinyl group content increases, it becomes easier to improve the mechanical properties of the final cured product at room temperature and high temperature. 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 number-average molecular weight (Mn) on a standard polystyrene basis, which is known to those skilled in the art by the GPC (gel permeation chromatography) method. 1 H-NMR measurement and / or quantitative mode 13 The composition can be obtained by comparing the composition obtained by 13C-NMR measurement with the vinyl group content derived from aromatic polyene monomer units. Such methods are obvious and well known to those skilled in the art. For example, the composition of ethylene-norbornene-styrene-ethylvinylbenzene-divinylbenzene copolymer, a representative example of the copolymer of the present invention, can also be determined by the following method. 1 H-NMR measurement and quantitative mode 13 ¹¹¹ NMR measurements were performed to determine the NMR peak area intensity of aromatic vinyl / vinylene groups. 1 H, 13 From C), determine the proportion of divinylbenzene units (a), and determine the strength of the ethyl group attached to the benzene ring ( 1 H, 13 From C), determine the proportion (b) of ethyl vinylbenzene units, which are present in small amounts as impurities in divinylbenzene, and the area strength of the benzene ring (1 H, 13 The proportion of styrene units (c) is determined by subtracting the contributions of (a) and (b) from C), and finally the area intensity of the aliphatic hydrocarbon region ( 1 H, 13 From C), subtract the contributions of (a), (b), and (c) to determine the proportion (d) of olefin units (total of ethylene and norbornene units). Separately, the area intensity ratio of each peak in the aliphatic hydrocarbon region ( 13 From C), the ratio of ethylene to norbornene units (e) can be determined, and by combining (a), (b), (c), (d), and (e), it is possible to determine the content of ethylene, norbornene, styrene, divinylbenzene, and ethylvinylbenzene.

[0031] The content of aromatic polyene monomer units in the copolymer of the present invention is arbitrary, but preferably less than 30% by mass, more preferably less than 18% by mass, and most preferably less than 15% by mass. With such a content, the number of crosslinking groups is appropriately suppressed, and the effect of improving stability during copolymer production and curing is obtained.

[0032] Examples of α-olefin-aromatic vinyl compound-aromatic polyene copolymers as one embodiment of the copolymer of the present invention include ethylene-styrene-divinylbenzene copolymer, ethylene-ethylvinylbenzene-divinylbenzene copolymer, ethylene-propylene-styrene-divinylbenzene copolymer, ethylene-1-octene-styrene-divinylbenzene copolymer, and propylene-styrene-divinylbenzene copolymer. Specific examples of suitable α-olefin-cyclic olefin-aromatic vinyl compound-aromatic polyene copolymers include one or more from the group consisting of ethylene-norbornene-styrene-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-hexene-styrene-styrene-norbornene-divinylbenzene copolymer, and 1-octene-norbornene-styrene-divinylbenzene copolymer. Copolymers obtained by substituting norbornene with dimethanooctahydronaphthalene (DMON), trimetanododecahydroanthracene (TMDA), phenylnorbornene (5-phenylbicyclo[2.2.1]hept-2-ene), or methylphenylnorbornene (5-methyl-5-phenylbicyclo[2.2.1]hept-2-ene) are also examples of preferred copolymers of the present invention.

[0033] The olefin-aromatic vinyl compound-aromatic polyene copolymer preferably used in the compositions of the present invention is a copolymer in which at least cyclic olefin monomer units are included. By including cyclic olefin monomer units as part of the olefin monomer units, the dielectric loss tangent of the copolymer itself can be made lower compared to the case where cyclic olefins are not included. For example, when a cured product of the copolymer alone is made using the copolymer and the minimum necessary curing agent, the dielectric loss tangent measured at 10 GHz is lower compared to the case where cyclic olefin monomer units are not included. Therefore, it is preferable to use a copolymer containing cyclic olefin monomer units in a composition and its cured product in order to lower the dielectric loss tangent in particular. Furthermore, as described above, increasing the content of cyclic olefin monomer units raises the glass transition temperature of the copolymer, allowing the copolymer and its cured product to harden. Considering that insulating materials for CCLs, three-dimensional high-integrated circuit packaging, or chiplets, which are preferred applications of the present invention, are hard and require a lower coefficient of thermal expansion close to that of wiring metals such as silicon and copper, a higher content of cyclic olefin monomer units as described above is preferable. Furthermore, some of the olefin monomer units in the olefin-aromatic vinyl compound-aromatic polyene copolymer contain cyclic olefin monomer units, and the higher the number of cyclic olefin monomer units, i.e., the higher the glass transition temperature of the copolymer, the higher the thermal conductivity of the cured product of this composition tends to be.

[0034] In one embodiment of the olefin-aromatic vinyl compound-aromatic polyene copolymer, a form is also provided in which the content of α-olefin monomer units is 0% by mass (i.e., does not contain α-olefin monomer units). Such copolymers are also referred to herein as "cyclic olefin-aromatic vinyl compound-aromatic polyene copolymers."

[0035] In the composition of the present invention, multiple olefin-aromatic vinyl compound-aromatic polyene copolymers with different compositions and molecular weights may be used.

[0036] <Organic crosslinked particles containing olefin-aromatic vinyl compound-aromatic polyene copolymer> The organic crosslinked particles containing the olefin-aromatic vinyl compound-aromatic polyene copolymer of the present invention can be cured on their own, or they may be formed from a composition in which the copolymer of the present invention is combined with other materials. Here, the other materials may include the following: "polyfunctional monomer components," "monofunctional monomer components," "resin components," "solvents," "fillers," "other additives," etc.

[0037] <Polyfunctional monomeric components> The amount of polyfunctional monomer component that may be contained in the organic crosslinked particles of the present invention is arbitrary, but preferably 200 parts by mass or less, and more preferably 100 parts by mass or less, per 100 parts by mass of copolymer. Examples of such polyfunctional monomer components include aromatic polyenes, polyfunctional maleimides, polyfunctional cyanates, polyfunctional (meth)acrylates such as glycidyl (meth)acrylate and trimethylolpropane tri(meth)acrylate, and polyfunctional isocyanurates such as triallyl isocyanurate and tri(meth)acryl isocyanurate. Among these, aromatic polyenes are preferably used from the viewpoint of having excellent low dielectric properties. More preferably, ortho, meta, and para divinylbenzenes, or mixtures thereof, are used, and most preferably a mixture of meta and paradivinylbenzene is used.

[0038] <Monofunctional monomeric components> The amount of monofunctional monomer component that may be contained in the organic crosslinked particles of the present invention is arbitrary, but preferably 100 parts by mass or less, and more preferably 50 parts by mass or less, per 100 parts by mass of copolymer. Monomers that can be suitably used in the composition of the present invention preferably have a molecular weight of less than 1000, and more preferably less than 500. Monomers that can be suitably used in the composition of the present invention are the aromatic vinyl compound monomer and / or the aromatic vinylene monomer described below. Among the monomers, monomers that can be polymerized with a radical polymerization initiator are preferred. The monofunctional monomer component may be a monomer component that constitutes a part of the copolymer of the present invention.

[0039] <Aromatic vinylene monomer> The aromatic vinylene monomers that may be included in the organic crosslinked particles of the present invention refer to compounds having both a single aromatic ring having 9 to 30 carbon atoms or multiple fused aromatic rings and a vinylene group. Examples of such aromatic vinylene compounds include indenes, beta-substituted styrenes, and acenaphthenes. Examples of indenes include indene, various alkyl-substituted indenes, and phenyl-substituted indenes. Examples of beta-substituted styrenes include β-alkyl-substituted styrenes such as β-methylstyrene, or phenyl-substituted styrenes. Examples of acenaphthenes include acenaphthenes, various alkyl-substituted acenaphthenes, and various phenyl-substituted acenaphthenes. As aromatic vinylene compounds, the above-exemplary compounds may be used individually or in combination of two or more. From the viewpoint of industrial availability and radical polymerization, acenaphthenes are most preferred as aromatic vinylene compounds.

[0040] <Resin components> The organic crosslinked particles of the present invention may contain any resin component 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 that do not contain cyclic olefins can be used. Among these, hydrocarbon elastomers and olefin-aromatic vinyl compound-aromatic polyene copolymers that do not contain cyclic olefins are more preferred. Among hydrocarbon elastomers, conjugated diene polymers are preferred. Among conjugated diene polymers, 1,2-polybutadiene is preferred. The amount of resin component is preferably 100 parts by mass or less, and preferably 50 parts by mass or less, per 100 parts by mass of olefin-aromatic vinyl compound-aromatic polyene copolymer. If the amount of these resin components added is too high, the dielectric constant and dielectric loss tangent of the final cured product may increase. Furthermore, when a resin component is added to the olefin-aromatic vinyl compound-aromatic polyene copolymer, the ratio of the total mass of the olefin-aromatic vinyl compound-aromatic polyene copolymer and the resin component to the mass of the specific boron nitride powder is in the range of 15:85 to 70:30, and preferably in the range of 20:80 to 50:50.

[0041] <Hydroxide-based elastomers> The hydrocarbon elastomers suitable for use in the compositions 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 EPDM, conjugated diene polymers, aromatic vinyl compound-conjugated diene block copolymers or random copolymers, and one or more elastomers selected from their hydrides (hydrogenated products). These hydrocarbon elastomers may be modified by introducing functional groups with maleic anhydride or other compounds.

[0042] <Conjugated diene polymers> Examples of conjugated diene polymers include polybutadiene and 1,2-polybutadiene. Examples of aromatic vinyl compound-conjugated diene block copolymers or random copolymers, and their hydrides (hydrogenated products), include SBS, SIS, SEBS, SEPS, SEEPS, SEEBS, etc. Suitable 1,2-polybutadiene is available, for example, as a product of JSR Corporation, and also from Nippon Soda Co., Ltd. under the product names 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 their hydrides may be modified by introducing functional groups with maleic anhydride or other compounds. Among conjugated diene polymers, conjugated diene copolymers are preferred. Among these conjugated diene copolymers, hydrides of block copolymers such as SEBS, SEPS, SEEPS, and SEEBS are useful as compatibilizers between the copolymer of the present invention and other resin components. These are available from Asahi Kasei under the trade names ToughTec or SOE-SS, from Kuraray under the trade name Septon, and from Kraton under the trade name Kraton.

[0043] <Polyether resin> Examples of polyether resins include polyphenylene ether and polyether. For polyphenylene ether having functional groups, it is preferable that the molecular ends are modified with functional groups. Furthermore, when added for the purpose of curing the composition of the present invention, it is preferable that the molecule has multiple functional groups. For example, modified polyphenylene ether is preferable. Examples of functional groups include radically polymerizable functional groups and epoxy groups, with radically polymerizable functional groups being preferable. Among radically polymerizable functional groups, vinyl groups are preferred. As vinyl groups, one or more from the group consisting of allyl groups, (meth)acryloyl groups, and aromatic vinyl groups are preferred, one or more from the group consisting of (meth)acryloyl groups and aromatic vinyl groups are more preferred, and aromatic vinyl groups are most preferred. In other words, in the composition of the present invention, a bifunctional polyphenylene ether in which both ends of the molecular chain are modified with radically polymerizable functional groups is particularly preferred. Examples of such polyphenylene ethers include Noryl(trademark) SA9000 from SABIC Corporation (a modified polyphenylene ether with methacryloyl groups at both ends, number average molecular weight 2200) and a bifunctional polyphenylene ether oligomer from Mitsubishi Gas Chemical Corporation (OPE-2St, a modified polyphenylene ether with vinylbenzyl groups at both ends, number average molecular weight 1200). In addition, allylated PPE from Asahi Kasei Corporation and aromatic polyethers from JSR Corporation (ELPAC HC-F series) can also be used. Among these, the bifunctional polyphenylene ether oligomer from Mitsubishi Gas Chemical Corporation (OPE-2St) and the aromatic polyethers from JSR Corporation (ELPAC HC-F series) can be used.

[0044] <Aromatic polyene resins> Aromatic polyene resins include divinylbenzene-based reactive polybranched 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 novel IPN-type low dielectric loss materials using them" (Masataka Kawabe et al., Journal of the Electronics Packaging Society of Japan, p. 125, Vol. 12, No. 2 (2009)). The aromatic polyene resin in this embodiment is a resin (polymer) substantially composed of aromatic polyene monomer units and aromatic monovinyl compound monomer units, and more preferably, this aromatic polyene resin does not contain olefin monomer units. The aromatic polyene resin in this embodiment is preferably a resin obtained by cationic polymerization or anionic polymerization.

[0045] <Solvent> In producing the organic crosslinked particles of the present invention, a suitable solvent may be added to the composition containing the copolymer as needed. The solvent is used to adjust the viscosity, fluidity, and dispersibility of the composition. Volatile solvents are preferred, such as cyclohexane, toluene, ethylbenzene, and mixed alkanes. In particular, the amount used is preferably in the range of 10 to 2000 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. Generally, it is preferable to substantially remove the solvent from the organic crosslinked particles obtained by drying or the like after emulsion polymerization of the composition as shown below.

[0046] <Filler> Inorganic or organic fillers may be added as needed. Known inorganic fillers can be used, and are added for purposes such as controlling the coefficient of thermal expansion, controlling thermal conductivity, and reducing costs. From the viewpoint of reducing the coefficient of thermal expansion, silica, particularly fused silica or fused silica treated to reduce dielectric strength, is preferably used. From the viewpoint of imparting thermal conductivity, boron nitride (BN), particularly aggregated boron nitride with reduced anisotropy, is preferably used. The amount of filler is 100 parts by mass or less, preferably 50 parts by mass or less, per 100 parts by mass of organic cross-linked particles. From the viewpoint of low dielectric properties, the amount of inorganic filler used should be kept low, as adding fillers significantly increases the dielectric constant; preferably, no filler is added.

[0047] Furthermore, instead of inorganic fillers, organic fillers such as high molecular weight polyethylene, ultra-high molecular weight polyethylene, polystyrene, styrene-divinylbenzene copolymer, or fluororesins can be used. As for fluororesins, any known resin containing fluorine, such as PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxyalkane), can be used. An example of such a resin is AGC's Fluon+(registered trademark) EA-2000. If 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 viewpoint of heat resistance that the organic filler itself is crosslinked, and it is preferable that it be formulated in the form of fine particles or powder. These organic fillers can also suppress the increase in dielectric constant and dielectric loss tangent. The amount added is 100 parts by mass or less, preferably 50 parts by mass or less, per 100 parts by mass of organic crosslinked particles.

[0048] <Other additives> This composition may further contain one or more selected from flame retardants and surface modifiers. The composition of the present invention can serve as a matrix for organic crosslinked particles.

[0049] <Flame retardant> Known flame retardants can be used in the compositions of the present invention. Preferred flame retardants, from the viewpoint of maintaining a low dielectric constant and low dielectric loss tangent, are known organophosphorus compounds such as phosphate esters or condensates thereof, known brominated flame retardants, and red phosphorus. Among phosphate esters in particular, compounds having multiple xylenyl groups in the molecule are preferred from the viewpoint of flame retardancy and low dielectric loss tangent.

[0050] Furthermore, in addition to flame retardants, antimony compounds such as antimony trioxide, antimony tetroxide, 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-triallyloxy-1,3,5-triazine may be added as flame retardant aids. 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. Alternatively, a polyphenylene ether (PPE)-based resin with low dielectric constant and excellent flame retardancy may be used in amounts of 30 to 200 parts by mass per 100 parts by mass of the flame retardant.

[0051] <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 surface modifier used is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the composition of the present invention other than the surface modifier. Examples of surface modifiers include various silane coupling agents and titanate coupling agents. One or more of the various silane coupling agents and titanate coupling agents may be used.

[0052] The composition used as a raw material for producing organic crosslinked particles according to the present invention is obtained by mixing, dissolving, or melting one or more selected from "polyfunctional monomer components," "monofunctional monomer components," "resin components," "solvents," "fillers," "other additives," etc. Furthermore, common additives that are normally added to resins, such as lubricants, stabilizers, antioxidants, weathering agents, and UV absorbers, can be used to the extent that the objectives of the present invention are not hindered. Any known method can be used for mixing, dissolving, or melting these components.

[0053] <Method for producing organic cross-linked particles> The organic crosslinked particles of the present invention can be produced by carrying out known emulsion polymerization of a composition containing an olefin-aromatic vinyl compound-aromatic polyene copolymer in the presence of a curing agent, emulsifier, or dispersant. In this specification, emulsion polymerization is a concept that also includes suspension polymerization, which is polymerized using an emulsifier or dispersant.

[0054] <Hardening agent> The curing agent that may be included in this composition may be any known curing agent that can be used for the polymerization or curing of aromatic polyenes and aromatic vinyl compounds. Alternatively, any known curing agent, polymerization initiator, or radical generator used in conventional emulsion polymerization can be used. An example of such a material is a radical polymerization initiator. Preferably, these are organic peroxides (peroxides), azos (AIBN, etc.), inorganic peroxides (persulfates such as potassium persulfate or hydrogen peroxide), etc., and can be freely selected depending on the application and conditions. There are no particular restrictions on the amount of curing agent used, but generally, 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 these curing agents, the curing treatment should be performed at an appropriate temperature and time, taking into account their half-life. The conditions in this case are arbitrary depending on the curing agent, but generally a temperature range of about 50°C to 100°C is appropriate.

[0055] <Emulsifier> While known emulsifiers such as nonionic and anionic emulsifiers can be used in emulsion polymerization, nonionic emulsifiers or anionic emulsifiers containing ammonium ions that do not contain metal ions are preferably used to avoid contamination of the final organic crosslinked particles with metal ions or anions. If emulsifier remains in the resulting organic crosslinked particles, the low dielectric properties of the organic crosslinked particles may deteriorate, requiring washing of the resulting organic crosslinked particles. In particular, when using anionic emulsifiers, thorough washing of the resulting organic crosslinked particles is necessary to remove ionic components.

[0056] After emulsion polymerization is complete, the emulsion is destroyed by a known method (emulsification destruction) to obtain organic crosslinked particles. To avoid contamination of the final organic crosslinked particles with metal ions or anions, emulsion destruction is preferably performed by adding alcohol, centrifugation, heating / cooling, etc. After emulsion destruction, the water tank is removed, and if necessary, an organic solvent is added to the organic layer containing the organic crosslinked particles, and the mixture is repeatedly washed with water or the like to remove any remaining emulsifiers or curing agents. After removing the water layer, an organic solvent may be added to disperse the organic crosslinked particles in the organic layer and recover them. After removing the water tank, the organic solvent can also be removed by an appropriate method and dried to recover the organic crosslinked particles as a solid powder.

[0057] <Organic crosslinked particles> As described above, the average particle size (median diameter D50) of the organic crosslinked particles obtained from the composition of the present invention is in the range of 0.1 to 5.0 μm, preferably in the range of 0.3 to 3.0 μm. Among the organic crosslinked particles of the present invention, those containing a relatively soft olefin-aromatic vinyl compound-aromatic polyene copolymer can be formed into a smooth sheet by adding a relatively small amount of aromatic polyene monomer or aromatic vinyl compound and heating and pressurizing under appropriate conditions, so that the dielectric properties of the organic crosslinked particles can be measured directly using the sheet. Furthermore, among the organic crosslinked particles of the present invention, those containing a particularly relatively hard olefin-aromatic vinyl compound-aromatic polyene copolymer cannot be formed into a sheet by heating and pressurizing treatment, so that a crosslinked sheet can be produced by mixing it with a curable resin with known dielectric properties and performing a crosslinking treatment under appropriate conditions. Here, the dielectric properties of the organic crosslinked particles alone can be determined by extrapolation from the dielectric properties of cured sheets prepared by varying the ratio of organic crosslinked particles to curable resin. The dielectric constant and dielectric loss tangent are measured by a known resonator method. In this specification, the resonator method shall be performed at 23°C and a measurement frequency of 10 GHz.

[0058] The dielectric constant of the organic crosslinked particles obtained as described above is preferably 2.0 to 3.5, and more preferably 2.1 to 3.0. The dielectric loss tangent is preferably 0.0002 to 0.002, and more preferably 0.0002 to 0.0010. These values ​​are preferred, for example, for insulating materials used for high-frequency signals of 3 GHz or higher.

[0059] <Composition containing organic crosslinked particles> Furthermore, in one embodiment, the present invention is a composition containing the organic crosslinked particles. By curing the composition of the present invention, a low dielectric cured body can be obtained. The organic crosslinked particles can be cured on their own, even without other polymer components, in the presence of a curing agent. The composition may contain a solvent for dispersing the organic crosslinked particles. The composition of the present invention may further contain a curable resin. Known curable resins can be used as the curable resin, but preferably a curable resin that can be cured by radicals. Preferred curable resins are one or more selected from the "olefin-aromatic vinyl compound-aromatic polyene copolymer" and "resin component" exemplified by the hydrocarbon elastomer, polyether resins having multiple functional groups in one molecule including polyphenylene ether, and aromatic polyene resins, which may or may not contain the cyclic olefin. The composition may also contain the "curing agent," "polyfunctional monomer component," "monofunctional monomer component," "solvent," "filler," and "other additives," and in particular, if a solvent is included, the composition may be a varnish. These compositions and varnishes can be molded into uncured or semi-cured articles (e.g., sheets) by known methods, and optionally through a drying process, and then cured under appropriate conditions to obtain a cured article.

[0060] The coefficient of linear expansion (CTE) of the cured material obtained from the composition of the present invention is preferably 150 ppm or less, more preferably 80 ppm or less, at temperatures between 0°C and 200°C. Those skilled in the art can determine the composition formulation having the above physical property parameters and prepare a cured material by referring to the information described herein and in the publicly known materials. The cured material 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 monomers in the composition and aromatic polyenes as monomer components are kept below a certain percentage.

[0061] <Applications of cured products of organic crosslinked particles or compositions containing organic crosslinked particles and curable resins> The organic crosslinked particles of the present invention, or the cured body of a composition comprising organic crosslinked particles and a curable resin, can be used as a base material or substrate, such as single-layer or multi-layer printed circuit boards, flexible printed circuit boards, so-called single-layer or multi-layer CCL substrates, single-layer or multi-layer FCCL substrates, and single-layer or multi-layer RCC substrates. Furthermore, it can 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.

[0062] In one embodiment of the present invention, a method for producing the above copolymer can also be provided. This method involves copolymerizing monomers of olefins such as α-olefins and cyclic olefins, aromatic vinyl compounds, and aromatic polyenes by coordination polymerization.

[0063] Coordination polymerization is a polymerization method that uses a coordination polymerization catalyst consisting of a transition metal compound and a co-catalyst. Preferred transition metal compounds include zirconium, hafnium, titanium, iron, nickel, cobalt, and palladium. In particular, for copolymerizing cyclic olefin monomers, transition metal compounds containing zirconium, titanium, nickel, iron, and palladium are preferred. Most preferably, the coordination polymerization catalyst used is one consisting of a transition metal compound represented by the following general formula (1) and a co-catalyst. More preferably, the production method includes a step of copolymerizing monomers such as olefins (including α-olefins and cyclic olefins), aromatic vinyl compounds, and aromatic polyenes using a polymerization catalyst consisting of a transition metal compound represented by the following general formula (1) and a co-catalyst.

[0064] General formula (1) [ka]

[0065] In the above formula, A and B are each independently selected from an unsubstituted or substituted cyclopentaphenanthryl group, an unsubstituted or substituted benzoindenyl group, an unsubstituted or substituted cyclopentadienyl group, or an unsubstituted or substituted indenyl group.

[0066] Y is a methylene group, silylene group, ethylene group, germylene group, or boron residue that has bonds with A and B and also has 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 from each other or the same. Also, Y may have a cyclic structure. Most preferably, Y is a methylene group that has bonds with A and B and also has 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.

[0067] X is hydrogen, a 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 1 to 4 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a dialkylamide group having 1 to 6 carbon atoms.

[0068] M is a transition metal, preferably zirconium, hafnium, or titanium.

[0069] To obtain copolymers with relatively low molecular weight and low viscosity when made into varnish, preferably, A and B in the above general formula (1) may each be independently selected from unsubstituted or substituted cyclopentadienyl groups or unsubstituted or substituted indenyl groups, and it is particularly preferable to use a transition metal compound having both unsubstituted or substituted cyclopentadienyl groups and unsubstituted or substituted indenyl groups. To obtain copolymers with a high aromatic polyene content, that is, copolymers with 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 unsubstituted or substituted indenyl groups and unsubstituted or substituted benzoindenyl groups. In the case of copolymers with a high aromatic polyene monomer unit content, it is possible to increase the crosslinking density of the cured product obtained by curing, and for example, a cured product with a storage modulus of 5 MPa or higher measured at 280°C can be obtained.

[0070] As co-catalysts in the polymerization catalyst of the present invention, known co-catalysts used in combination with transition metal compounds can be used. Preferably, such co-catalysts include aluminum compounds and boron compounds. As aluminum compounds, almoxanes such as methylaluminoxane (or methylalmoxane or MAO) are preferably used. Alkylaluminum such as triisobutylaluminum or triethylaluminum may also be used. Examples of such co-catalysts include co-catalysts and alkylaluminum compounds described in European Patent Application Publication No. 0872492A2, Japanese Patent Publication No. 11-130808, Japanese Patent Publication No. 9-309925, International Publication No. 00 / 20426, European Patent Application Publication No. 0985689A1, and Japanese Patent Publication No. 6-184179.

[0071] Examples of boron compounds include trispentafluorophenylborane, triphenylcarbeniumtetrakis(pentafluorophenyl)borate {trityltetrakis(pentafluorophenyl)borate}, lithiumtetrakis(pentafluorophenyl)borate, trimethylammoniumtetraphenylborate, triethylammoniumtetraphenylborate, tripropylammoniumtetraphenylborate, tri(n-butyl)ammoniumtetraphenylborate, tri(n-butyl)ammoniumtetra(p-tolyl)phenylborate, tri(n-butyl)ammoniumtetra(p-ethylphenyl)borate, tri(n-butyl)ammoniumtetra(pentafluorophenyl)borate, trimethylammoniumtetra(p-tolyl)borate, trimethylammoniumtetrakis-3,5-dimethylphenylborate, and triethylammoniumtetrakis-3 ,5-dimethylphenyl borate, tributylammonium tetrakis-3,5-dimethylphenyl borate, tributylammonium tetrakis-2,4-dimethylphenyl borate, anilinium tetrakispentafluorophenyl borate, N,N'-dimethylanilinium tetraphenyl borate, 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 tetraphenyl borate, N,N'-2,4These include 5-pentaethylanilinium tetraphenylborate, di-(isopropyl)ammonium tetrakispentafluorophenylborate, dicyclohexylammonium 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. Furthermore, while a boron-containing co-catalyst with a phenyl group as an example of a fluorine-substituted aromatic group was given here, boron-containing co-catalysts having similarly fluorine-substituted condensed aromatic groups such as naphthyl groups can also be preferably used. The most preferred boron co-catalyst among these is a boron co-catalyst having boron and a fluorine-substituted aromatic group bonded to it. Examples of such co-catalysts include trispentafluorophenylborane, triphenylcarbeniumtetrakis(pentafluorophenyl)borate {trityltetrakis(pentafluorophenyl)borate}, lithiumtetrakis(pentafluorophenyl)borate, tri(n-butyl)ammoniumtetra(pentafluorophenyl)borate, tropyliumtetrakispentafluorophenylborate, and N,N'-dimethylaniliniumtetrakis(pentafluorophenyl)borate. Particularly preferred are triphenylcarbeniumtetrakis(pentafluorophenyl)borate {trityltetrakis(pentafluorophenyl)borate}, and N,N'-dimethylanilinium tetrakis(pentafluorophenyl)borate is used. These most preferred boron-containing co-catalysts are sometimes referred to as TRI-FABA or TRI-FAB, and DAN-FABA or DAN-FAB, respectively, and can be purchased from Tosoh Finechem Co., Ltd. or Kanto Chemical Co., Ltd.

[0072] The co-catalyst is used in a ratio of aluminum atoms to transition metal atoms of 0.1 to 100,000, preferably 10 to 10,000, relative to the metal of the transition metal compound. A ratio of 0.1 or higher effectively activates the transition metal compound, while a ratio of 100,000 or lower is economically advantageous. The transition metal compound and co-catalyst may be mixed and prepared outside the polymerization equipment, or mixed inside the equipment during polymerization.

[0073] In particular, for co-catalysts such as almoxanes, the aluminum atom / transition metal atom ratio with respect 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 higher effectively activates the transition metal compound, while a ratio of 100,000 or lower is economically advantageous. When using a boron compound as a co-catalyst, the boron atom / transition metal atom 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 higher effectively activates the transition metal compound, while a ratio of 100 or lower is economically advantageous.

[0074] In preferred embodiments, a boron compound is essential, and an aluminum compound may be used as a co-catalyst if necessary. By using a boron compound as a co-catalyst, the amount of metal components such as aluminum derived from the aluminum compound contained in the final copolymer can be reduced, and the dielectric constant and dielectric loss tangent values ​​of the final organic crosslinked particles and the cured composition containing them can be reduced to a particularly preferred range, for example, the dielectric constant can be 2.5 or less and the dielectric loss tangent can be 0.0010 or less.

[0075] In one embodiment, an olefin-aromatic vinyl compound-aromatic polyene copolymer can be provided in which the total metal content derived from the catalyst and co-catalyst is 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 used in the catalyst (as described above) and the boron and / or aluminum derived from the boron and / or aluminum compounds used in the co-catalyst, and can be defined as the sum of the 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 metals 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. In this specification, boron is included in the category of metals. When organic crosslinked particles are produced using an olefin-aromatic vinyl compound-aromatic polyene copolymer having a total metal content of 1500 ppm or less, preferably 1000 ppm or less, and most preferably 500 ppm or less, the properties of a dielectric constant of 2.5 or less and a dielectric loss tangent of 0.0010 or less at 10 GHz can be satisfied. [Examples]

[0076] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0077] The method for producing the copolymer used in the present invention is shown in the following synthesis example. The copolymer obtained in the synthesis example was analyzed by the following means. The content of ethylene, cyclic olefin, styrene, ethyl vinylbenzene, and vinyl group units derived from divinylbenzene in the copolymer was determined by: 1 H-NMR measurement and quantitative mode 13¹³C-NMR measurements were performed, and the area intensity of the obtained peaks was determined by known methods. The sample was dissolved in deuterated 1,1,2,2-tetrachloroethane, and the measurements were performed at 80–130°C. In this specification, copolymers may also be referred to as "resins."

[0078] <Molecular weight> The molecular weight was determined by GPC (gel permeation chromatography) to obtain the number-average molecular weight (Mn) on a standard polystyrene basis. The measurements were performed under the following conditions. Two TSK-GEL MultiporeHXL-M columns (φ7.8×300mm, manufactured by Tosoh Corporation) were connected in series. Column temperature: 40℃ Solvent: THF Fluid flow rate: 1.0 ml / min. Detector: RI detector

[0079] <Glass transition temperature> The glass transition temperature of organic crosslinked particles was determined by DSC (Digital Spectroscopy). Using a DSC214Polyma scanner manufactured by Netsch, 2.5 mg of the sample was accurately weighed into an aluminum pan and measured under the following heating conditions with a nitrogen atmosphere. The value obtained from the second run was used. Heating / cooling conditions: 25℃→-50℃: 10℃ / min -50℃→250℃(1stRun):10℃ / min 100℃→-50℃: 10℃ / min -50℃→250℃(2ndRun):10℃ / min

[0080] <Gel component> The gel content was determined as insoluble matter in boiling toluene according to ASTM D2765-84. However, since organic cross-linked particles pass through the metal mesh, the gel content was determined by centrifuging the suspension after boiling toluene treatment and determining the mass of the insoluble matter.

[0081] <Dielectric constant (Dk) and dielectric loss (dielectric loss tangent (Df))> The dielectric constant (relative permittivity) and dielectric loss tangent of the single-cured olefin-aromatic vinyl compound-aromatic polyene copolymer were measured using the cavity resonator perturbation method (Agilent Technologies 8722ES network analyzer, Keysight Technologies 10 GHz split-cylinder resonator). A 0.1 mm × 25 mm × 30 mm sample cut from a cured sheet was used, and values ​​were measured at 23°C and 10 GHz. Measurements were taken for both the uncured and cured states.

[0082] <Quantitative determination of metal content in copolymers> The metal content (in the example below, the content of the transition metal elements used in the metal catalyst, and the content of boron and aluminum used in the co-catalysts) was determined as follows. Furthermore, the content of hafnium, titanium, iron, nickel, cobalt, and palladium was also quantified. Measurements were taken by ICP emission spectrometry under the following conditions in accordance with JIS K0116:2014. 0.5 g of the composition to be measured was weighed into a platinum crucible and ashed using a hot plate, electric stove, and electric furnace (heated gradually to 600°C). 0.5 mL of HCl(1+1) (i.e., a 1:1 volume mixture of hydrochloric acid and water) and ultrapure water were added to the residue, and after heating and dissolution, the volume was adjusted to 5 ml to prepare the test solution. Quantitative analysis was performed using ICP emission spectrometry (using an Agilent 5110VDV).

[0083] <Average particle size> In this specification, the average particle size (median diameter D50) was determined using a laser diffraction scattering particle size distribution analyzer, specifically the "LS-13 320" (product name) manufactured by Beckman Coulter, in accordance with ISO 13320:2009.

[0084] ap value> IR measurement method I ap Value = I(3025cm) -1 :Aromatic CH expansion / contraction) / I(2920cm -1 :Aliphatic CH expansion / contraction)

[0085] ​<Copolymer P-1 (Ethylene-styrene-divinylbenzene copolymer)> Ethylene-styrene-divinylbenzene copolymer P-1 was produced according to the production method using the catalyst dimethylmethylenebis(cyclopentadienyl)zirconium dichloride described in International Publication No. 2022 / 014599, and the production method using a boron compound as a co-catalyst in the examples of International Publication No. 2017 / 122295.

[0086] <Copolymer P-2 (ethylene-norbornene-styrene-divinylbenzene copolymer)> The raw material used was divinylbenzene (DVB), a product manufactured by Nippon Steel Chemical & Material Co., Ltd., named "Divinylbenzene (81%)" (liquid at room temperature, a mixture of meta and para isomers containing 81% by mass of divinylbenzene, with the remainder being ethylvinylbenzene). Norbornene (75% concentration, toluene solution) manufactured by Maruzen Petrochemical Co., Ltd. was used as a raw material, and after adding a small amount of triisobutylaluminum (TIBA) and stirring at room temperature, it was purified by distillation under nitrogen. A 10L polymerization tank equipped with a heating and cooling jacket and a stirrer was used for polymerization. First, the inside of the polymerization tank, which had been thoroughly dried, was purged with nitrogen, and 1.4 kg of toluene, 0.23 kg of norbornene (as pure content), 3.0 kg of styrene, and 0.60 kg of divinylbenzene (as 81% divinylbenzene by mass) were charged in, and approximately 20 L of dry nitrogen was bubbled in at an internal temperature of 60°C. Subsequently, the polymerization chamber was purged with ethylene gas, and TIBA (manufactured by Kanto Chemical Co., Ltd.) was added in the form of 6 mmol of aluminum and stirred. The internal temperature was stabilized at 80°C, and the internal pressure of the polymerization chamber was increased and stabilized at 0.1 MPaG (gauge) using nitrogen. Then, from a catalyst tank installed on top of the polymerization chamber, a catalyst solution was added to the polymerization chamber. This solution consisted of 200 μmol of dimethylmethylenebis(cyclopentadienyl)zirconium dichloride (formula 1) as a catalyst, 2 mmol of TIBA, 100 g of toluene solution, and 210 μmol of tritilium tetrakis(pentafluorophenyl) borate dissolved in it and stirred. Polymerization was then started. Polymerization continued while maintaining the internal temperature at 60°C and the internal pressure at 0.1 MPaG (ethylene pressure). When the ethylene consumption reached 100 g, 50 g of isopropanol, a polymerization inhibitor, was added to the polymerization chamber to stop the polymerization. The obtained polymerization solution was added in small amounts to a sufficiently large methanol / acetone mixed solution, the precipitated polymer was stirred and filtered to recover the polymer, and then thoroughly vacuum-dried at room temperature to obtain P-2, an ethylene-norbornene-styrene-divinylbenzene copolymer.

[0087] Formula (1) [ka]

[0088] <Copolymer P-3 (ethylene-norbornene-styrene-divinylbenzene copolymer)> Similar to P-2, however, 2.0 kg of toluene, 2.0 kg of norbornene (as pure), 0.80 kg of styrene, and 0.20 kg of divinylbenzene (as 81% divinylbenzene) were charged. Polymerization was continued while maintaining the internal temperature at 90°C and the internal pressure at 0.1 MPaG of ethylene pressure. When the ethylene consumption reached 40 g, 50 g of isopropanol, a polymerization inhibitor, was added to the polymerization reactor to stop the polymerization. The obtained polymerization solution was added in small amounts to a sufficiently large methanol / acetone mixed solution, and the precipitated polymer was stirred and filtered to recover the polymer. The polymer was then thoroughly vacuum-dried at room temperature to obtain P-3, an ethylene-norbornene-styrene-divinylbenzene copolymer.

[0089] Since P-1, P-2, and P-3 obtained in each example contained small amounts of residual monomer and solvent, they were redissolved in toluene, and the solutions were added in small amounts to a sufficiently large methanol / acetone mixed solution. The precipitated polymer was stirred, filtered, and dried under vacuum at room temperature for 24 hours to obtain purified polymers. The composition, molecular weight, and metal content derived from the catalyst and co-catalyst of the obtained P-1 to P-3 are shown in Table 1. The purified polymers were again dissolved in toluene to obtain a 60% by mass toluene solution (varnish).

[0090] <Preparation and evaluation of single-component cured copolymers> Varnishes containing 60% by mass of each of P-1 to P-3 were dissolved with an initiator at a concentration of 0.75% by mass relative to the resin mass. Perbutyl P was used for P-1, and the azo initiator VR-110 was used for P-2 and P-3. These varnishes were poured into a Teflon® mold (frame length 7cm, width 7cm, thickness 0.2mm) on a PET sheet placed on a glass plate, thoroughly air-dried at 25°C, and then dried in a vacuum dryer at 100°C for 3 hours to obtain an uncured sheet that was substantially free of solvent. Multiple sheets of the uncured material were stacked to the required thickness for each measurement, if necessary. A Teflon sheet was placed on a smooth metal plate, and the uncured sheets were placed on top of that. A mold of the required thickness, another Teflon sheet, and a smooth metal plate were then placed on top of that. For P-1 and P-2, the materials were heated in a vacuum press under a load of 5 MPa at 150°C for 30 minutes, and then at 200°C for 30 minutes. For P-3, the materials were heated at 200°C for 30 minutes and then at 250°C for 30 minutes. After that, the Teflon sheet and Teflon mold were removed to obtain a cured sheet (a sheet cured by the resin alone). The gel content, dielectric constant, and dielectric loss tangent (both measured at 23°C and 10 GHz) of the obtained cured sheet were determined. These results are shown in Table 1.

[0091] [Table 1]

[0092] <Example 1> (Emulsification polymerization) A reaction apparatus equipped with a 1L reaction vessel, condenser, stirrer, stirring blades, thermometer, and oil bath was prepared. 250g of deionized water and 66g of a 10% by weight aqueous solution of PVA-217 (manufactured by Kuraray) were mixed to form the aqueous layer. 22g of P-1 (as pure content), 33g of divinylbenzene (manufactured by Fujifilm Wako Chemical Co., Ltd., mixture of m and p isomers, 93% by mass purity as DVB) as DVB, 1.3g of 2,2-azobisisobutyronitrile (AIBN), and 18.4g of toluene were mixed to form the oil layer. The aqueous layer was placed in the 1L reaction vessel, and the oil layer was added while emulsifying and dispersing at a rotation speed of 12000 rpm for 3 minutes using a homogenizer emulsifier to obtain a milky white liquid. The milky white liquid was placed in the above-mentioned reaction apparatus and gradually heated while stirring until the liquid temperature reached approximately 90°C. The polymerization reaction was then carried out for approximately 4 hours while maintaining the temperature at approximately 90°C. After cooling to room temperature, the mixture was filtered through a filter cloth to obtain an emulsion with a recovered amount of 372 g and a solid content of 14.5% by mass. The emulsion was centrifuged using a centrifuge (centrifugal acceleration 43,200 g) to separate the cross-linked microparticles from the clear aqueous layer, and then the clear aqueous layer was removed. A large amount of methanol was added to redisperse the mixture, and then it was centrifuged again in the same manner, separating the layers, and the methanol layer was removed. This operation was repeated several times. Using a sample moistened with methanol, the average particle size was measured after further dilution with methanol. White cross-linked microparticles (powder, organic cross-linked particles 1) were obtained by drying at approximately 80°C for about half a day.

[0093] <Example 2> Except for changing copolymer P-1 to P-2, emulsion polymerization was carried out in the same manner as in Example 1 to obtain organic crosslinked particles 2.

[0094] <Example 3> Except for changing copolymer P-1 to P-3, changing the amount of P-3 used to 11g, and changing the amount of toluene to 44g, emulsion polymerization was carried out in the same manner as in Example 1 to obtain organic crosslinked particles 3.

[0095] <Example 4> (Emulsification polymerization) Emulsion polymerization was carried out in the same manner as in Example 3, except that copolymer P-3 was used, 2,2-azobisisobutyronitrile (AIBN) 0.11 g was replaced, and the liquid temperature was changed to 80°C, yielding an emulsion with a recovered amount of approximately 390 g and a solid content of 11.6% by mass. Post-treatment was performed in the same manner as in the example to obtain organic crosslinked particles 4.

[0096] [Table 2]

[0097] The median diameter, gel content, and I of the obtained organic crosslinked particles ap Table 2 shows the values ​​and glass transition temperatures obtained by DSC. Figure 1 shows a TEM image of organic crosslinked particles 1 obtained in Example 1. For the 30 organic crosslinked particles within the field of view of the TEM image, the minimum diameter was within -20% of the maximum diameter in three dimensions. That is, when comparing the longest and shortest diameters of the particles in the TEM image, the minimum diameter was within -20% of the maximum diameter.

[0098] The gel content of each organic crosslinked particle is sufficiently high, indicating that crosslinking is progressing. Furthermore, when powdered P-1 was subjected to heating and pressurizing treatment at 5 MPa, 200°C, and 1 hour for 1 hour, no melting of the powder was observed, which also indicates that crosslinking is progressing sufficiently.

[0099] Median diameter, I ap The values ​​also satisfied the scope of the present invention. The Tg was higher than that of the single cured product of the raw material olefin-aromatic vinyl compound-aromatic polyene copolymer.

[0100] (Dielectric properties of organic crosslinked particles) Next, the dielectric properties of the organic crosslinked particle 4 were measured for Example 4. The measurement was performed in accordance with JIS C2565, using a 10 GHz cylindrical cavity resonator and a Keysight P9373B network analyzer at 10 GHz and 23°C. The relative permittivity and dielectric loss tangent of the organic crosslinked particle 4 were determined using the true specific gravity and bulk specific gravity of the organic crosslinked particle 4, which were measured separately. As a result, the relative permittivity was 2.1 and the dielectric loss tangent was 0.0009.

[0101] The organic crosslinked particles of the present invention exhibit excellent low dielectric properties and high Tg, making them useful as additives to various low-dielectric curing materials.

Claims

1. Organic crosslinked particles comprising an olefin-aromatic vinyl compound-aromatic polyene copolymer, wherein the olefin comprises at least a cyclic olefin component. The olefin-aromatic vinyl compound-aromatic polyene copolymer satisfies all of the following (1) to (5): (1) The number-average molecular weight of the copolymer is between 500 and 50,000; (2) The aromatic vinyl compound monomer is an aromatic vinyl compound having 8 to 20 carbon atoms, and the content of aromatic vinyl compound monomer units is 0.1% by mass or more and 70% by mass or less; (3) The cyclic olefin has a hydrocarbon ring structure without heteroatoms, and the content of the cyclic olefin monomer is 10% by mass or more and 95% by mass or less; (4) The aromatic polyene monomer is one or more selected from polyenes having 5 to 20 carbon atoms and having multiple vinyl and / or vinylene groups in the molecule, and the content of vinyl and / or vinylene groups derived from the aromatic polyene monomer unit is 2 to 30 per number average molecular weight; (5) The total of olefin monomer units, aromatic vinyl compound monomer units, and aromatic polyene monomer units is 100% by mass; Organic cross-linked particles with a median diameter D50 in the range of 0.1 to 5.0 μm.

2. The organic crosslinked particles according to claim 1, further comprising a polyfunctional monomer.

3. I (3025 cm) measured by IR -1 : aromatic C-H expansion / contraction) / I (2920cm -1 The organic crosslinked particle according to claim 1, wherein the aliphatic C-H stretching ratio is 0.10 or more and 1.20 or less.

4. The organic crosslinked particle according to claim 1, wherein the gel content is 80% by mass or more.

5. The organic crosslinked particle according to claim 1, wherein the glass transition temperature (Tg) measured by the DSC method is 100°C or higher and 350°C or lower.

6. The organic crosslinked particle according to claim 1, wherein the olefin-aromatic vinyl compound-aromatic polyene copolymer satisfies the following: The olefin monomer units are one or more selected from α-olefin monomer units having 2 to 30 carbon atoms and cyclic olefin monomer units having 7 to 30 carbon atoms, and their content is 5% by mass or more and 95% by mass or less.

7. The organic crosslinked particle according to claim 1, which is an olefin-aromatic vinyl compound-aromatic polyene copolymer exhibiting a dielectric constant of 2.5 or less and a dielectric loss tangent of 0.0010 or less, as measured at 10 GHz and 23°C.

8. A method for producing organic crosslinked particles according to any one of claims 1 to 7, wherein polymerization is carried out by emulsion polymerization using the olefin-aromatic vinyl compound-aromatic polyene copolymer and a polyfunctional monomer.

9. A composition comprising organic crosslinked particles according to any one of claims 1 to 7.

10. Furthermore, the composition according to claim 9, comprising a curable resin.

11. The composition according to claim 10, wherein the curable resin is one or more selected from olefin-aromatic vinyl compound-aromatic polyene copolymers, hydrocarbon elastomers, polyether resins having multiple functional groups in one molecule including polyphenylene ether, and aromatic polyene resins.

12. A cured body of the composition according to claim 9.

13. The cured body according to claim 12, which is in the form of a sheet.

14. The cured body according to claim 12, wherein the coefficient of linear expansion (CTE) at 0°C to 200°C is 150 ppm or less.

15. A CCL, FCCL, interlayer insulating material, or RCC comprising organic crosslinked particles according to any one of claims 1 to 7.

16. A cured body according to claim 12, comprising CCL, FCCL, interlayer insulating material, or RCC.

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