Composition, molded article, cured article, and laminate

Abstract

The present disclosure provides an insulating material capable of achieving both sufficiently high heat dissipation and sufficiently low dielectric loss tangent permittivity. Specifically, the composition contains (a) a specific olefin-aromatic vinyl compound-aromatic polyene copolymer and (b) boron nitride particles, and is characterized in that: the volume ratio of the component (a) to the component (b) is in the range of 98-15: 2-85; the value of the dielectric loss tangent of a cured body of the composition as determined by a split cylinder resonator method at a measurement frequency of 35-42 GHz is 2 * 10 <-3 > or less, and the thermal conductivity of the cured body of the composition as determined by a laser flash method at 23 DEG C is 0.6 [W / m * K] or more.

Description

TECHNICAL FIELD

[0001] The present application relates to a composition and a cured body thereof, and the like, and particularly to a composition and a cured body thereof, and the like, which have high heat dissipation performance and excellent low dielectric properties. BACKGROUND

[0002] With the development of communication frequencies to the gigahertz band and higher, there is a growing demand for multilayer substrates, transmission lines, antennas, and the like formed of a CCL or FCCL including an insulating material having low dielectric properties. As an insulating material having low dielectric properties, an ethylene-olefin-polyene copolymer such as that described in Patent Literature 1 has attracted attention. In addition, attempts have been made to incorporate silica having prescribed properties as a filler into the ethylene-olefin-polyene copolymer to make it suitable for a solder reflow process (Patent Literature 2).

[0003] PRIOR ART DOCUMENTS PATENT LITERATURE Patent Literature 1: Japanese Patent Application Publication No. 2009-161743 Patent Literature 2: International Publication No. 2022 / 054885 SUMMARY

[0004] PROBLEMS TO BE SOLVED BY THE INVENTION With the increasing demand for highly integrated package elements in the construction of electronic substrates, it is believed that insulating materials used therefor must have both sufficiently high heat dissipation properties and sufficiently low dielectric loss tangent and dielectric constant. However, insulating materials such as fluorine-based resins (perfluoroethylene, etc.), epoxy resins, unsaturated polyester resins, polyimide resins, and phenolic resins, and the like, which have been known in the past, cannot achieve the trade-off of the above properties.

[0005] In view of the foregoing problems, there is a desire to achieve a new type of insulating material that can achieve a trade-off of sufficiently high heat dissipation properties and sufficiently low dielectric loss tangent and dielectric constant. The present application was made in view of the above problems. An object of the present application is to provide a composition, a molded body and a cured body, and a laminate, a single-layer CCL, a multilayer CCL, a single-layer FCCL or a multilayer FCCL substrate, and the like, which have both high heat dissipation properties and low dielectric loss tangent and dielectric constant.

[0006] MEANS FOR SOLVING THE PROBLEMS In view of the foregoing problems, the present application provides various specific modes as shown below.

[0007] Mode 1. A composition characterized by containing (a) an olefin-aromatic vinyl compound-aromatic polyene copolymer satisfying all of the following conditions (i) to (iv) and (b) boron nitride particles, (i) the number average molecular weight of the copolymer is 500 or more and less than 100,000.

[0008] (ii) The aromatic vinyl compound monomer unit is an aromatic vinyl compound with 8 to 20 carbon atoms, and the content of the aromatic vinyl compound monomer unit is 70% by mass or less.

[0009] (iii) The aromatic polyene monomer unit is selected from one or more polyenes having 5 to 20 carbon atoms having multiple vinyl and / or vinylidenes in the molecule, and the content of vinyl and / or vinylidenes from the aromatic polyene monomer unit is 1.5 or more and less than 20 on a number-average molecular weight basis.

[0010] (iv) The olefin monomer unit is selected from one or more olefins having 2 to 20 carbon atoms, the content of the aforementioned olefin monomer unit is 30% by mass or more, and the total of the aforementioned olefin monomer unit, the aforementioned aromatic vinyl compound monomer unit and the aforementioned aromatic polyene monomer unit is 100% by mass.

[0011] The volume ratio of component (a) to component (b) is in the range of 98-15:2-85. The dielectric loss tangent of the cured composition, determined using the split cylindrical resonator method, at a measurement frequency of 35–42 GHz, is 2 × 10⁻⁶. -3 the following, The thermal conductivity of the cured composition of the aforementioned composition at 23°C, determined by laser flash method, is 0.6 [W / m·K] or higher.

[0012] Method 2. The composition as described in Method 1, wherein the aforementioned component (b) comprises spherical boron nitride particles.

[0013] Method 3. The composition as described in method 1 or 2, wherein the aforementioned component (b) is determined by X-ray photoelectron spectroscopy using O 1s The semi-quantitative value calculated from the peak intensity is the same as that measured using the same method for B. 1s The ratio of the semi-quantitative values ​​calculated from the peak intensity B 1s / O 1s The value is below 90.

[0014] Method 4. The composition of any one of methods 1 to 3, wherein the cumulative diameter (D50) of the aforementioned component (b) as measured by laser diffraction scattering without homogenization is 35 μm or less.

[0015] Method 5. The composition of any one of methods 2 to 4, wherein the average roundness of the aforementioned component (b) is 0.80 or more.

[0016] Method 6. The composition as described in any one of methods 1 to 5, wherein the aforementioned component (b) is determined by X-ray photoelectron spectroscopy using O 1s The semi-quantitative value calculated from the peak intensity is above 0.6.

[0017] Method 7. The composition of any one of methods 1 to 6 further comprises one or more of the ingredients selected from the group consisting of the following (c) to (g).

[0018] (c) Curing agent (d) Inorganic fillers with components different from those in (b) above. (e) A resin that differs from the composition of (a) above and is selected from one or more resins in the group consisting of hydrocarbon elastomers, polyether resins, and aromatic polyene resins. (f) Monomer (g) Solvent Method 8. A molded body obtained from any one of the compositions in methods 1 to 7.

[0019] Method 9. The molded body as described in Method 8 is in sheet shape.

[0020] Method 10. A cured body, which is a cured body of the molded body described in method 8 or 9.

[0021] Method 11. The molded body as described in method 8 or 9, or the cured body as described in method 10, is an electrically insulating material.

[0022] Method 12. A laminate comprising a metal foil and a layer containing the composition of any one of methods 1 to 7.

[0023] Method 13. A cured body, which is a cured body of the laminate described in method 12.

[0024] Method 14. A single-layer CCL, a multi-layer CCL, a single-layer FCCL, or a multi-layer FCCL substrate, wherein the aforementioned single-layer CCL, multi-layer CCL, single-layer FCCL, or multi-layer FCCL substrate includes the molded body described in method 8, 9, or 11, the cured body described in method 10, 11, or 13, or the laminate described in method 12.

[0025] Invention Effects According to the present invention, it is possible to achieve both sufficiently high heat dissipation and sufficiently low dielectric loss tangent and dielectric constant in insulating materials. Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail. However, these embodiments are merely examples for illustrating the present invention, and the present invention is not limited thereto. That is, the present invention can be implemented with any modifications without departing from its spirit.

[0027] In this specification, olefin-aromatic vinyl compound-aromatic polyene copolymers are sometimes abbreviated as "copolymers". Unless otherwise specified, numerical ranges in this specification include both the upper and lower limits. For example, the expression "1~100" includes both the lower limit "1" and the upper limit "100". The same applies to other numerical ranges. Furthermore, in this specification, the term "sheet" also includes the concept of a film. Even when referred to as a film, this specification also includes the concept of a sheet.

[0028] <Composition> One embodiment of the present invention relates to a composition characterized in that it comprises olefin-aromatic vinyl compound-aromatic polyene copolymer and boron nitride particles (hereinafter sometimes simply referred to as the "composition") having a certain range of composition and molecular weight as described below. This composition can be molded into a molded body (e.g., a sheet shape). Furthermore, this composition is preferably curable, in which case a cured body can be obtained by curing under specified conditions. The cured body of this composition is preferably an electrically insulating material.

[0029] <(a) Olefin-Aromatic Vinyl Compound-Aromatic Polyene Copolymer> The copolymer is characterized by satisfying all of the following conditions (i) to (iv).

[0030] (i) The number average molecular weight of the copolymer is 500 or more and less than 100,000, preferably 5,000 or more and less than 100,000, and more preferably 5,000 or more and less than 50,000.

[0031] (ii) The aromatic vinyl compound monomer unit is an aromatic vinyl compound with 8 to 20 carbon atoms, and the content of the aromatic vinyl compound monomer unit is 70% by mass or less, more preferably 10% by mass or more than 70% by mass, and even more preferably 10% by mass or more than 60% by mass.

[0032] (iii) The aromatic polyene monomer unit is selected from one or more polyenes having 5 to 20 carbon atoms having a plurality of vinyl and / or vinylidenes in the molecule, and the content of vinyl and / or vinylidenes from the aromatic polyene monomer unit is 1.5 or more and less than 20 in terms of number average molecular weight, preferably 3 or more and less than 20, more preferably 3 or more and less than 10.

[0033] (iv) The olefin monomer unit is selected from one or more olefins having 2 to 20 carbon atoms, and the content of the aforementioned olefin monomer unit is 30% by mass or more, preferably 30% by mass or more and 90% by mass or less, and the total of the aforementioned olefin monomer unit, the aforementioned aromatic vinyl compound monomer unit and the aforementioned aromatic polyene monomer unit is 100% by mass.

[0034] This olefin-aromatic vinyl compound-aromatic polyene copolymer can be obtained, for example, by copolymerizing the monomers of the olefin, the aromatic vinyl compound, and the aromatic polyene.

[0035] The term "olefin monomer" refers to one or more α-olefins selected from those having 2 to 20 carbon atoms and cyclic olefins having 5 to 20 carbon atoms, and is a compound composed of carbon and hydrogen that substantially does not contain oxygen, nitrogen, or halogens. Examples of α-olefins 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, but these are not particularly limited. Examples of cyclic olefins having 5 to 20 carbon atoms include norbornene and cyclopentene, but these are not particularly limited. Preferred olefins include combinations of ethylene with α-olefins other than ethylene and cyclic olefins, or the use of ethylene alone, but these are not particularly limited.

[0036] Aromatic vinyl compound monomers are aromatic vinyl compounds with 8 to 20 carbon atoms. Examples of aromatic vinyl compound monomers include, but are not particularly limited to, styrene, p-methylstyrene, p-isobutylstyrene, various vinylnaphthalenes, and various vinylanthracenes.

[0037] Aromatic polyene monomers are polyenes having 5 to 20 carbon atoms and containing a plurality of vinyl groups and / or vinylides (preferably vinyl groups) within their molecules. Aromatic polyene monomers are preferably polyenes with 8 to 20 carbon atoms. Preferred aromatic polyene monomers are polyenes having 8 to 20 carbon atoms and containing a plurality of vinyl groups within their molecules. More preferably, they are compounds having an aromatic vinyl structure and substantially free of oxygen, nitrogen, and halogens, consisting of carbon and hydrogen, such as various divinylbenzenes (ortho-, meta-, and para-divinylbenzenes), divinylnaphthalene, divinylanthracene, p-2-propenylstyrene, and p-3-butenylstyrene. Additionally, bifunctional aromatic vinyl compounds as described in Japanese Patent Application Publication No. 2004-087639, such as 1,2-bis(vinylphenyl)ethane (abbreviated as BVPE), can be used as aromatic polyene monomers. Among these, various divinylbenzenes (ortho-, meta-, and para-divinylbenzenes), or mixtures thereof, are preferred, and a mixture of meta- and para-divinylbenzenes is most preferred. In this specification, these divinylbenzenes are sometimes simply referred to as divinylbenzene (DVB) class. When divinylbenzene class is used as an aromatic polyene, it has high curing efficiency and is easy to cure, and is therefore preferred.

[0038] Each monomer of the above-mentioned olefins, aromatic vinyl compounds, and aromatic polyenes may contain other olefins containing polar groups such as oxygen atoms, nitrogen atoms, etc., aromatic vinyl compounds containing oxygen atoms, nitrogen atoms, etc., or aromatic polyenes containing oxygen atoms, nitrogen atoms, etc. The total mass of these monomers containing polar groups can be appropriately set according to the desired performance, without particular limitation, preferably 10% by mass or less of the total mass of the composition, more preferably 3% by mass or less, and most preferably substantially free of monomers containing polar groups. By setting the monomer to 10% by mass or less, the low dielectric properties (low dielectric constant, low dielectric loss) of the cured body obtained by curing the composition can be further improved.

[0039] The number-average molecular weight (Mn) of this copolymer is 500 or more and less than 100,000, preferably 5,000 or more and less than 100,000, more preferably 5,000 or more and less than 50,000, and even more preferably 5,000 or more and less than 30,000. By setting it within this range, it is possible to obtain an effect that makes it less sticky in the uncured state and improves its thermoplasticity, thereby easily imparting good physical properties such as high tensile strength and high elongation at break to the final cured body. If the number-average molecular weight is less than 500, the mechanical properties of the composition in the uncured stage are low and the adhesion is high, so sometimes the molding and processing of this composition as a thermoplastic resin becomes difficult. If the number-average molecular weight is 100,000 or more, the molding processability sometimes decreases. It should be noted that, in this specification, the number-average molecular weight of 500 or more and less than 100,000 refers to the molecular weight obtained by GPC (gel permeation chromatography) and converted to standard polystyrene, which falls within this range.

[0040] The content of aromatic vinyl compound monomer units in this copolymer is 0% by mass or more and 70% by mass or less, preferably 0% by mass or more and less than 70% by mass, more preferably 10% by mass or more and 60% by mass or less. It should be noted that, in this specification, the method of 0% by mass of aromatic vinyl compound monomer units also includes olefin-aromatic vinyl compound-aromatic polyene copolymers. When the content of aromatic vinyl compound monomer units is greater than 70% by mass, the glass transition temperature of the cured composition is near room temperature, and sometimes the toughness and elongation at low temperatures decrease. If the content of aromatic vinyl compound monomer units is 10% by mass or more, there is a tendency for the aromaticity of this copolymer to improve, the affinity with fillers to be better, and the dispersibility of boron nitride particles to be excellent. Furthermore, if the content of aromatic vinyl compound monomer units is 10% by mass or more, there is a tendency to easily obtain a cured composition with improved dispersibility and high peel strength to copper foil and copper wiring.

[0041] In this copolymer, the content of vinyl and / or vinylidene units from aromatic polyene monomer units is 1.5 or more and less than 20, preferably 3 or more and less than 20, and more preferably 3 or more and less than 10, based on the number average molecular weight of the copolymer. In this specification, the content of vinyl and / or vinylidene units is sometimes collectively referred to as "vinyl content". When the vinyl content is less than 1.5, the crosslinking efficiency is low, making it difficult to obtain a cured body with sufficient crosslinking density. If the vinyl content increases, there is a tendency to easily improve the mechanical properties of the final cured body at both room temperature and high temperature. The vinyl content from aromatic polyene monomer units (e.g., divinylbenzene units) in this copolymer, based on the number average molecular weight, can be obtained, for example, by comparing the number average molecular weight (Mn) calculated using GPC (gel permeation chromatography) methods known to those skilled in the art with that of standard polystyrene. 1 The content of vinyl groups and vinylidene groups derived from aromatic polyene monomer units is obtained by comparing H-NMR measurements. As an example, this is achieved by comparing the content of vinyl groups derived from aromatic polyene monomer units. 1 By comparing the intensities of the peak areas obtained from H-NMR measurements, the vinyl content of the copolymer from aromatic polyene monomer units (e.g., divinylbenzene units) is 0.6% by mass. Given a number-average molecular weight of 49,000 (based on GPC measurements converted from standard polystyrene), the molecular weight of the vinyls from the aromatic polyene monomer units in this number-average molecular weight is their product, 294. Dividing this by the formula weight of vinyl, 130, yields 2.3. Therefore, the vinyl content from aromatic polyene monomer units in this copolymer, calculated on a unit number-average molecular weight basis, is 2.3. The copolymer's... 1 The assignments of peaks obtained from H-NMR measurements are known in the literature. Furthermore, based on... 1 The method of determining the composition of a copolymer by comparing peak areas obtained from H-NMR measurements is also known. Furthermore, measurements using known quantitative modes can also be used as an auxiliary method. 13 The peak areas and their ratios in the C-NMR spectrum. Additionally, in this specification, the peak intensity of the vinyl group from the divinylbenzene unit (based on...) 1 The content of aromatic polyene monomer units in the copolymer (hereinafter, the explanation focuses on the case of divinylbenzene units, but is not limited to the case of divinylbenzene units) is determined by H-NMR determination. That is, based on the vinyl content from the divinylbenzene units, one vinyl unit is considered to come from one divinylbenzene unit in the copolymer, and the content of divinylbenzene units is determined.

[0042] In this copolymer, the content of olefin monomer units is 30% by mass or more, preferably 30% by mass or more and 90% by mass or less, and more preferably 30% by mass or more and 60% by mass or less. The total content of olefin monomer units, aromatic vinyl compound monomer units, and aromatic polyene monomer units is 100% by mass. If the content of olefin monomer units is 30% by mass or more, the following tendencies exist: the toughness (elongation) of the final cured body is improved, cracks during the curing process are not generated, the impact resistance of the cured body decreases, and cracks occur in the thermal cycling test of the cured body.

[0043] <Method for manufacturing olefin-aromatic vinyl compound-aromatic polyene copolymer> This copolymer can be manufactured by copolymerizing monomers of aromatic vinyl compounds, aromatic polyenes, and olefins as needed using coordination polymerization. The copolymer can be manufactured efficiently using a single-site coordination polymerization catalyst composed of a transition metal compound and a cocatalyst, as described in, for example, Japanese Patent Application Publication No. 2009-161743, Japanese Patent Application Publication No. 2010-280771, and International Publication No. 00 / 37517.

[0044] In this copolymer, olefin-aromatic polyene copolymers that do not contain aromatic vinyl compound monomer units are preferred examples, specifically ethylene-divinylbenzene copolymers, ethylene-propylene-divinylbenzene copolymers, ethylene-1-butene-divinylbenzene copolymers, ethylene-1-hexene-divinylbenzene copolymers, and ethylene-1-octene-divinylbenzene copolymers.

[0045] In this copolymer, examples of olefin-aromatic vinyl compound-aromatic polyene copolymers comprising aromatic vinyl compound monomer units include ethylene-styrene-divinylbenzene copolymers, ethylene-propylene-styrene-divinylbenzene copolymers, ethylene-1-hexene-styrene-divinylbenzene copolymers, and ethylene-1-octene-styrene-divinylbenzene copolymers. This copolymer can be manufactured using, for example, the manufacturing methods described in International Publication No. 00 / 37517, Japanese Patent Application Publication No. 2009-161743, and Japanese Patent Application Publication No. 2010-280771.

[0046] <(b) Boron nitride particles> This composition is characterized by containing boron nitride (BN) particles. The boron nitride particles may include spherical boron nitride particles, flake-like primary boron nitride particles, and secondary particles as aggregates thereof; spherical boron nitride particles are preferred. Examples of boron nitride include hexagonal boron nitride (h-BN) and cubic boron nitride (c-BN). It should be noted that, in this specification, "spherical" means that when observed using a scanning electron microscope at 10,000x magnification, the particles are observed to be in a round or slightly curved particle shape.

[0047] The preferred embodiment involves boron nitride particles determined by X-ray photoelectron spectroscopy. 1s The semi-quantitative value calculated from the peak intensity and the B value determined by X-ray photoelectron spectroscopy 1s The ratio of the semi-quantitative values ​​calculated from the peak intensity B 1s / O 1s The value can be 90 or less, more preferably 85 or less, even more preferably 80 or less, even more preferably 75 or less, and particularly preferably 70 or less. B 1s / O 1s The lower limit of the value can be appropriately set according to the desired performance, and is not particularly limited. Preferably, it is 10 or higher, more preferably 15 or higher, and even more preferably 20 or higher. This B value is preferred. 1s / O 1s The ratio is in the range of 10 to 90, 15 to 85, or 20 to 80.

[0048] In this instruction manual, B 1s / O 1s The ratio is calculated by removing the background using the Shirley method from B. 1s Peak intensity and O 1s The semi-quantitative value calculated from the peak intensity is then used to determine the background shape. It should be noted that the Shirley method is a method that, for the inelasticly scattered electrons that constitute the background, assumes no energy dependence and that the number of electrons undergoing inelastic scattering is proportional to the peak intensity, to determine the background shape to be subtracted. If B... 1s / O 1s When the ratio is 90 or less, the boron nitride particles exhibit excellent dispersibility in water due to their surface state, and there is a tendency to easily achieve an effect that improves the flowability of the composition when mixed with the aforementioned copolymer.

[0049] B for boron nitride particles 1s / O 1sWhen adjusting the ratio, this can be achieved by cavitation treatment of boron nitride particles (preferably spherical boron nitride particles) used as raw materials in a liquid containing water. Cavitation treatment of boron nitride particles in a liquid containing water can break up the aggregated state while maintaining the shape of the primary particles. A large number of hydroxyl groups are introduced onto the surface of the broken primary particles, which can reduce the B... 1s / O 1s The value was adjusted to below 90. Details regarding cavitation treatment will be described in detail later.

[0050] One embodiment involves boron nitride particles, measured by X-ray photoelectron spectroscopy (XPS). 1s The semi-quantitative value calculated from the peak intensity is preferably 0.6 (0.60) or higher, more preferably 0.65 or higher, and even more preferably 0.7 (0.70) or higher. From this O... 1s The upper limit of the semi-quantitative value calculated from the peak intensity can be, for example, 5.0 or less, more preferably 4.0 or less, further preferably 3.0 or less, and even more preferably 2.0 or less. Preferably, this O... 1s The semi-quantitative value of the peak intensity can be in the range of 0.6 (0.60) to 5.0, 0.65 to 4.0, or 0.7 (0.70) to 3.0.

[0051] One embodiment involves boron nitride particles measured using X-ray photoelectron spectroscopy. 1s The semi-quantitative value of the peak intensity is preferably less than 48.4 (48.40), more preferably less than 48.35, and even more preferably less than 48.3 (48.30).

[0052] In one embodiment, the cumulative diameter (D50) of the boron nitride particles, measured by laser diffraction scattering without specific dispersion treatment such as homogenizer treatment (i.e., without applying external force), is preferably 35 μm or less, more preferably 33 μm or less, further preferably 32 μm or less, even more preferably 30 μm or less, and particularly preferably 28 μm or less. It should be noted that the lower limit of D50 measured without homogenizer treatment is not particularly limited; for example, it can be 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more. It should be noted that in this specification, the term "cumulative diameter (D50)" refers to the particle size whose cumulative value in the cumulative particle size distribution of the volume reference, measured by laser diffraction scattering (refractive index: 1.7), corresponds to 50% of the particle size. The cumulative particle size distribution is represented by a distribution curve with particle size (μm) on the horizontal axis and cumulative value (%) on the vertical axis. The fact that the D50 is still small even without homogenization means that the particles are small, and the proportion of primary particles is higher than that of secondary particles. This characteristic improves the flowability of the composition filled with boron nitride particles.

[0053] One embodiment of the boron nitride particles can be further processed into smaller particles by homogenization. For example, the volumetric cumulative diameter (D50) of the boron nitride particles after homogenization in ethanol (conditions: 300W, 90sec) evaluated by laser diffraction scattering is preferably 0.6 (0.60) μm or less, more preferably 0.58 μm or less, and even more preferably 0.56 μm or less. In addition, the D50 measured after homogenization can be, for example, 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.3 μm or more.

[0054] In one embodiment, the average spherical roundness of the primary particles of the spherical boron nitride particles is preferably 0.80 or higher, more preferably 0.82 or higher, and even more preferably 0.84 or higher. It should be noted that the upper limit of the average roundness is not particularly limited; for example, it can be 1 or less, or 0.95 or less. Preferably, the average roundness can be in the range of 0.80 or more but 1 or less, or 0.82 or more but 0.95 or less. If the average roundness is within the above range, there is a tendency to easily obtain an effect of improved flowability of the composition filled with boron nitride particles.

[0055] In this specification, "average roundness" refers to the value calculated as follows. For images of boron nitride particles taken using a scanning electron microscope (SEM) (magnification: 10,000x, image resolution: 1280 × 1024 pixels), the projected area (S) and perimeter (L) of the boron nitride particles were calculated using image analysis software (Mountech, trade name: MacView). Roundness was then calculated using the projected area (S) and perimeter (L) according to the following formula: Circularity = 4πS / L².

[0056] The average roundness is defined as the average roundness of 100 randomly selected boron nitride particles (preferably primary particles).

[0057] <Methods for manufacturing boron nitride particles> Boron nitride particles used as raw materials can be manufactured using known methods without particular limitation. The method described in International Publication No. 2015 / 122379 is preferred for producing spherical boron nitride particles. For example, spherical boron nitride particles as raw materials can be manufactured as follows: A boron ester with a molar ratio of 1 to 10 of ammonia / boron ester is reacted with ammonia in an inert gas stream at a temperature of 750°C or higher for 30 seconds or less; then, the mixture is heat-treated at 1,000 to 1,600°C for 1 hour or more in an atmosphere of ammonia or a mixture of ammonia and an inert gas; and finally, calcined at 1,800 to 2,200°C for 0.5 hours or more in an inert gas atmosphere. Known boron esters can be used as the boron ester, without particular limitation; for example, trimethyl borate.

[0058] Additionally, as needed, the aforementioned boron nitride particles are added to a liquid containing water (preferably pure water) to generate cavitation bubbles (bubbles generated when the liquid becomes low-pressure). The secondary particles of the boron nitride are broken down into primary particles by the expansion and contraction forces caused by the pressure difference of the generated bubbles. Simultaneously, the surface state of the particles is changed by increasing the proportion of hydroxyl groups. Cavitation bubbles can be generated using commercially available equipment (such as a powder suction continuous dissolution and dispersion device) to induce foaming in the liquid using reduced pressure or ultrasound. Circulation of the liquid is particularly preferred. Powder suction continuous dissolution and dispersion devices generally have a mechanism that generates flow rate using stirring blades. The rotational speed of the stirring blades can be appropriately set according to the desired performance and is not particularly limited, but is preferably 2,000 to 10,000 rpm, more preferably 4,000 to 9,000 rpm, further preferably 4,500 to 8,000 rpm, even more preferably 5,000 to 8,000 rpm, and particularly preferably 6,000 to 7,200 rpm.

[0059] In one embodiment, regarding the process of generating cavitation bubbles, the number of cavitation processes, calculated from the rotational speed (rpm) of the stirring blades of the apparatus and the discharge rate, is preferably performed 50 times or more, more preferably 100 times or more, and even more preferably 150 times or more. Regarding the process of generating cavitation bubbles, B can be easily eliminated by performing the process of generating cavitation bubbles 50 times or more. 1s / O 1s The ratio is adjusted to below 90. Extending the cavitation treatment time can further reduce B. 1s / O 1s The tendency of B. Additionally, by treating under conditions with abundant cavitation bubbles or extending the cavitation treatment time, the surface hydroxyl groups can be increased, further reducing B. 1s / O 1s Compare.

[0060] In one embodiment, the composition may further comprise one or more selected from the group consisting of: a curing agent; an inorganic filler different from the boron nitride particles described above; a resin different from the copolymer described above and selected from the group consisting of hydrocarbon elastomers, polyether resins and aromatic polyene resins; a monomer; and a solvent.

[0061] <(c) Curing agent> As a curing agent that may be included in this composition, known curing agents that can be used in the polymerization or curing of aromatic polyenes and aromatic vinyl compounds can be used. Examples of such curing agents include free radical polymerization initiators, cationic polymerization initiators, and anionic polymerization initiators, but they are not particularly limited thereto. Free radical polymerization initiators are preferred. Organic peroxide-based (peroxide), azo-based polymerization initiators, etc., are more preferred, and can be freely selected according to the application and conditions. A catalog of products listing organic peroxides can be downloaded from the Nippon Oil Company website, for example, https: / / www.nof.co.jp / product-search / family / 1020001. In addition, organic peroxides are also listed in the catalogs of Fujifilm, Koujun Pharmaceutical Co., Ltd., Tokyo Chemical Industry Co., Ltd., etc. Curing agents that can be used in this embodiment can be obtained from these companies. As an example of an organic peroxide-based curing agent, Perhexyne 25B (manufactured by Nippon Oil Company) can be cited. In addition, known photopolymerization initiators that utilize light, ultraviolet light, or radiation can also be used as curing agents. Examples of photopolymerization initiators include photoradical polymerization initiators, photocationic polymerization initiators, and photoanionic polymerization initiators. Such photopolymerization initiators are available from companies such as Tokyo Chemical Industry Co., Ltd. Furthermore, curing can also be achieved using radiation or electron beams. Alternatively, crosslinking and curing can be performed through the thermal polymerization of the contained raw materials without a curing agent.

[0062] There is no particular limitation on the amount of curing agent used. Generally, it is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 10 parts by weight, in increments of 100 parts by weight of the copolymer. The above composition preferably does not contain curing agent or solvent. When using curing agents such as peroxide-based or azo-based polymerization initiators, curing is performed at a suitable temperature and time, taking into account their half-life. These conditions are arbitrary depending on the curing agent, but generally, a temperature range of approximately 50°C to 200°C is suitable.

[0063] <(d) Other Inorganic Fillers> Without prejudice to the purpose of this invention, known inorganic fillers (fillers) different from the boron nitride particles described above may be added to this composition. These fillers may be added for purposes such as controlling thermal expansion, controlling thermal conductivity, or reducing costs, and the amount used is arbitrary depending on the purpose. In particular, when adding inorganic fillers, known surface modifiers, such as silane coupling agents, are preferred. Silica or alumina may be added as inorganic fillers. Molten silica is preferred as silica. Such inorganic fillers are added in increments of 100 parts by weight of this copolymer, preferably 200 parts by weight or less, more preferably 100 parts by weight or less, and even more preferably 10 parts by weight or less. Furthermore, to improve and enhance low dielectric properties (low dielectric constant, low dielectric loss tangent), hollow fillers or fillers with numerous pores may be added.

[0064] <(e) Other resins> This composition may contain a resin different from the copolymers described above. Examples of such resins include hydrocarbon elastomers, polyether resins, and aromatic polyene resins.

[0065] As a hydrocarbon-based elastomer, one or more selected from ethylene-based, propylene-based elastomers, conjugated diene polymers, aromatic vinyl compound-conjugated diene block copolymers or random copolymers, and their hydrides (hydrogenated products) having free radical crosslinking functional groups are preferred. The amount of hydrocarbon-based elastomer used can be appropriately set according to the desired performance and is not particularly limited. From the viewpoint of improving the workability and molding processability of the uncured state of this composition, it can be added in increments of 100 parts by weight of the copolymer, preferably 100 parts by weight or less, more preferably 1 to 50 parts by weight, and even more preferably 1 to 30 parts by weight. The number-average molecular weight of the hydrocarbon-based elastomer preferably used in the composition of this embodiment is, for example, 500 or more and 100,000 or less, more preferably 1,000 or more and 4,500 or less.

[0066] Examples of ethylene-based elastomers include ethylene-octene copolymers, ethylene-1-hexene copolymers, and other ethylene-α-olefin copolymers, as well as EPR and EPDM. Examples of propylene-based elastomers include atactic polypropylene, low stereoregularity polypropylene, and propylene-1-butene copolymers, and other propylene-α-olefin copolymers, but these are not particularly limited. Examples of free radical crosslinking functional groups include vinyl, allyl, and ethylene-modified norbornene (units), which are commonly found in rubber raw materials such as EPDM, but these are not particularly limited. These free radical crosslinking soft resins can be modified by introducing functional groups through maleic anhydride or other compounds.

[0067] Examples of conjugated diene polymers include polybutadiene and 1,2-polybutadiene, but they are not particularly limited thereto. 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., but they are not particularly limited thereto. Preferred 1,2-polybutadiene is available, for example, from Nippon Soda under the product names B-1000, 2000, and 3000 for liquid polybutadiene. Additionally, a preferred copolymer containing a 1,2-polybutadiene structure is TOTAL CRAY VALLEY's "Ricon100". These conjugated diene polymers and their hydrides can be modified by introducing functional groups using maleic anhydride or other compounds. Among the conjugated diene polymers, polymers that do not contain vinylidene or have fewer vinylidene groups in their main chain are preferred. The vinylidene in the main chain tends to remain in the cured body after curing. This vinylidene readily reacts with oxygen in the air to produce polar groups containing oxygen. Therefore, after high-temperature durability tests of the cured body (e.g., 125°C in air), the dielectric constant and dielectric loss tangent tend to increase, making it undesirable. From this perspective, 1,4-polybutadiene copolymers are not preferred as conjugated diene polymers; 1,2-polybutadiene polymers or copolymers containing a 1,2-polybutadiene structure are preferred. Furthermore, from this perspective, various hydrogenated polymers in which the vinylidene content is significantly reduced by hydrogenation are preferred. Examples of hydrogenated conjugated diene polymers include hydrogenated SBR, SEBS, SEPS, SEEPS, and SEEBS, with hydrogenated polymers of conjugated diene polymers having methyl-substituted styrene being preferred.

[0068] Examples of polyether-based resins include polyphenylene ether and polyether, but they are not particularly limited thereto. As a 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 this embodiment, it is preferable that a plurality of functional groups are present within one molecule of the polyphenylene ether. For example, modified polyphenylene ether is preferred. Examples of functional groups include free radical polymerizable functional groups, epoxy groups, etc., with free radical polymerizable functional groups being preferred. As a free radical polymerizable functional group, vinyl groups are preferred. As a vinyl group, it is preferably selected from one or more of the group consisting of allyl, (meth)acryloyl, and aromatic vinyl groups, more preferably from one or more of the group consisting of (meth)acryloyl and aromatic vinyl groups, and most preferably aromatic vinyl groups. That is, in the composition of this embodiment, a bifunctional polyphenylene ether with both ends of the molecular chain modified by free radical polymerizable functional groups is particularly preferred. Examples of such polyphenylene ethers include SABIC's Noryl SA9000 (a modified polyphenylene ether with methacryl groups at both ends, with a number average molecular weight of 2200) and Mitsubishi Gas Chemical Company, Inc.'s difunctional polyphenylene ether oligomer (OPE-2St, a modified polyphenylene ether with vinyl benzyl groups at both ends, with a number average molecular weight of 1200), but are not particularly limited to these. Additionally, Asahi Kasei's allylated PPE and JSR's aromatic polyethers (ELPAC HC-F series) can also be used. Among these, Mitsubishi Gas Chemical Company, Inc.'s difunctional polyphenylene ether oligomer (OPE-2St) and JSR's aromatic polyethers (ELPAC HC-F series) are preferred.

[0069] The term "aromatic polyene resin" includes divinylbenzene reactive multibranched copolymers (PDV or ODV) manufactured by NIPPON STEEL Chemical & Material Co., Ltd. Such multibranched copolymers are described, for example, in the literature "Synthesis of Multifunctional Aromatic Vinyl Copolymers and Development of Novel IPN-Type Low Dielectric Loss Materials Using Them" (Masanao Kawabe, Journal of The Japan Institute of Electronics Packaging p125, Vol.12, No.2 (2009)).

[0070] The amount of polyether resin and aromatic polyene resin used can be appropriately set according to the desired performance, and there is no particular limitation. Relative to 100 parts by weight of this copolymer, the incremental amount is preferably 1 to 70 parts by weight, more preferably 1 to 50 parts by weight, and most preferably 1 to 30 parts by weight. The number average molecular weight of these resins can be appropriately set according to the desired performance, and there is no particular limitation. It is preferably 500 to 100,000, more preferably 1,000 to 4,500.

[0071] <(f) Monomer> This composition may also contain monomers, preferably free radical polymerizable monomers. The monomer content, in increments of 100 parts by weight of the copolymer, is preferably 10 parts by weight or less. It should be noted that this composition may be substantially monomer-free. If the monomer content is 10 parts by weight or less, the uncured composition does not exhibit viscous properties, and there is a tendency for it to be easier to process as a thermoplastic resin. The molecular weight of the monomers that can be used is preferably less than 1000, more preferably less than 500. Examples of such monomers include aromatic vinyl compound monomers, aromatic polyene monomers, and / or polar monomers, but are not particularly limited thereto. Aromatic vinyl compounds and aromatic polyenes are more preferred as such monomers. In addition, BVPE (1,2-bis(vinylphenyl)ethane) as described in Japanese Patent Application Publication No. 2003-212941 may also be used. From the viewpoint of improving the mechanical strength (elastic modulus) of the cured body at high temperatures, the aromatic polyene content is preferably 1 to 30 parts by weight or less, relative to 100 parts by weight of the copolymer. Furthermore, there is a tendency to use a smaller amount of polar monomers for the purpose of imparting adhesion to other materials required as insulating materials or to increase crosslinking density. Examples of such polar monomers include various maleimides, bismaleimides, maleic anhydride, glycidyl acrylate, triallyl isocyanurate, isocyanurate tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc., but are not particularly limited thereto. Maleimides and bismaleimides that can be used in this embodiment are described, for example, in International Publication No. 2016 / 114287 and Japanese Patent Application Publication No. 2008-291227, and can be purchased, for example, from Yamato Chemical Industries, Ltd. and Designer Molecules Inc. From the viewpoints of solubility in organic solvents, high-frequency characteristics, high adhesion to conductors, and moldability of prepreg blanks, these compounds containing maleimide groups are preferably bismaleimides.

[0072] <(g) solvent> Suitable solvents may be added to this composition as needed. Furthermore, the amount used is not particularly limited. The solvent is used to adjust the viscosity and flowability of the composition. In particular, when the composition is in the form of a varnish, a solvent is preferred. As a solvent, if the boiling point at atmospheric pressure is high, i.e., low volatility, there is a tendency for the thickness of the coated film to become more uniform; therefore, a solvent with a certain or higher boiling point is preferred. Regarding the preferred boiling point, at atmospheric pressure, it is preferably approximately 75°C or higher, and more preferably 100°C or higher and 300°C or lower. As a solvent, solvents known in the art can be used without particular limitation; for example, cyclohexane, cyclohexanone, methyl ethyl ketone (MEK), toluene, ethylbenzene, xylene, mesitylene, tetrahydronaphthalene, acetone, limonene, mixed alkanes, mixed aromatic solvents, etc., can be used. The amount of solvent used in the composition of this embodiment can be appropriately set according to the desired performance. It is any amount, and is preferably 5 to 500 parts by mass relative to 100 parts by mass of the composition, more preferably 10 to 300 parts by mass, and most preferably 50 to 150 parts by mass.

[0073] By combining a copolymer that satisfies all of the above conditions (i) to (iv) with spherical boron nitride particles (preferably B) 1s / O 1s Combining spherical boron nitride particles (with a ratio of 90 or less) with the copolymer can enhance the intermolecular forces between the copolymer and the spherical boron nitride particles (making them easier to adhere). While not wishing to be bound by a specific theory, it is speculated that spherical boron nitride particles with preferred properties exhibit particularly high affinity with copolymers having a defined structure through π-electron interactions on their surface, resulting in a preferred synergistic effect. In a further preferred embodiment, as a way to achieve an even better synergistic effect, a copolymer that satisfies all of the above conditions (i) to (iv) and B can be provided. 1s / O 1s A composition obtained by combining spherical boron nitride particles with a ratio of 10 to 90 and without homogenization, whose D50 is 5 μm to 35 μm as determined by laser diffraction scattering.

[0074] <Composition and Properties of the Composition> The composition is characterized in that it comprises the above-described copolymer and the above-described boron nitride particles in a volume ratio ranging from 98 to 15: 2 to 85. In a preferred embodiment, the volume ratio of the copolymer to the boron nitride particles in the composition can be in the range of 90 to 15: 10 to 85, more preferably in the range of 80 to 20: 20 to 80, and even more preferably in the range of 75 to 25: 25 to 75.

[0075] The dielectric loss tangent of the cured form of this composition is characterized by a value of 2 × 10⁻⁶, obtained using the split cylindrical resonator method at a measurement frequency of 35–42 GHz. -3 In a preferred embodiment, the dielectric loss tangent can be 1×10⁻⁶. -3 The following is more preferably 8×10 -4 the following.

[0076] The dielectric constant of the cured body of this composition, determined by the split cylindrical resonator method at a measurement frequency of 35-42 GHz, is preferably 4.0 or less, more preferably 3.5 or less, and even more preferably 3.0 or more and 3.5 or less.

[0077] The thermal conductivity of the cured body of this composition is characterized by being 0.6 [W / m·K] or higher at 23°C, as determined by laser flash method. In a preferred embodiment, this thermal conductivity can be 0.7 [W / m·K] or higher.

[0078] Previously known compositions have struggled to fully satisfy the aforementioned dielectric constant, dielectric loss tangent, and thermal conductivity. This composition exhibits a remarkable effect of simultaneously satisfying these properties at an excellent level. In the preferred embodiment, the cured form of the composition, as measured above, has a dielectric loss tangent of 1 × 10⁻⁶. -3 The dielectric constant is 0.7 [W / m·K] or higher, more preferably 4.0 or lower, and the dielectric loss tangent is 1 × 10⁻⁶. -3 The following are also thermally conductive and above 0.7 [W / m·K].

[0079] <General Uses of the Composition> This composition can be used as a 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 (copper clad laminate) substrate, or a single-layer or multi-layer FCCL (flexible copper clad laminate) substrate. Additionally, this composition can also be used as various electrical insulation materials for wiring (preferably for high-frequency signal wiring), such as cover layers, high-frequency transmission circuits, antennas, solder resists, build-up materials, interlayer insulating materials, bonding sheets, interlayer adhesives, and bump sheets for flip chip bonding machines.

[0080] In one embodiment, a laminate comprising a layer containing the above composition and a metal foil (preferably copper foil) may also be provided. In another embodiment, a cured version of the laminate may also be provided, as well as the aforementioned substrate comprising the laminate or the cured version.

[0081] Example The following examples and comparative examples illustrate the features of the present invention in more detail, but the present invention is not limited thereto. That is, the materials, amounts, proportions, processing contents, processing steps, etc., shown in the following examples can be appropriately modified as long as they do not depart from the spirit of the present invention. In addition, the various manufacturing conditions and evaluation results values ​​in the following examples have the meaning of preferred upper or lower limits in the embodiments of the present invention, and the preferred numerical range can be the range defined by the combination of the aforementioned upper or lower limits and the values ​​of the following examples or the values ​​of the examples.

[0082] <Synthesis Example: Preparation of Copolymers P1 and P2> Referring to the manufacturing methods described in Japanese Patent Application Publication No. 2009-161743 and Japanese Patent Application Publication No. 2010-280771, copolymers P1 and P2 were manufactured respectively. As catalysts, dimethylmethylene dicyclopentadienyl zirconium dichloride (structural formula (1) below) and rac-diphenylmethylene (1-indenyl) (cyclopentadienyl) zirconium dichloride (structural formula (2) below) were used.

[0083] Triphenylcarbamate tetra(pentafluorophenyl)borate ("TRI-FABA" manufactured by Tosoh Finechem Corporation) was used as a co-catalyst.

[0084] In addition, toluene is used as a solvent. Styrene, divinylbenzene, and ethylene are used as raw material monomers, and polymerization is carried out separately in a 10L polymerization reactor equipped with a stirrer and a heating and cooling jacket.

[0085] [Chemical Formula 1] [Chemical Formula 2] <Analysis of the chemical structure of copolymers> use 1 ¹H-NMR was used to calculate the composition ratios of ethylene (Et), α-olefins other than ethylene (1-octene in Example 4), styrene (St), and divinylbenzene (DVB) in the copolymer, as well as the content of vinyl units from divinylbenzene, based on the peak area intensities attributed to each component. The sample was dissolved in deuterated 1,1,2,2-tetrachloroethane, and the determination was performed at 23°C.

[0086] The NMR spectrum peaks are as follows.

[0087] 0.6~1.02ppm: CH3, 3H of α-olefins other than ethylene 0.6~2.1ppm: St + DVB + Et + CH2, 2H of α-olefins other than ethylene 5.1~5.4ppm: CH, 1H of DVB vinyl 6.3~7.8ppm: St aromatic ring C6H5, 5H; DVB aromatic ring C6H4, 4H <Determination of molecular weight> The number-average molecular weight (Mn) of the copolymer, converted to standard polystyrene, was determined using GPC (gel permeation chromatography). The determination was performed under the following conditions.

[0088] Column: 4 TSK-GEL MultiporeHXL-M Used for series connection of 7.8×300mm (manufactured by Tosoh Corporation).

[0089] Column temperature: 40℃ Solvent: THF (tetrahydrofuran) Liquid delivery flow: 1.0ml / min Detector: RI detector <Synthesis Example: Production of Copolymer P3> Using the same method as described above, wherein 1-octene, as an α-olefin, is also incorporated as a raw material, copolymer P3, which is an ethylene-1-octene-styrene-divinylbenzene copolymer, is obtained.

[0090] <Synthesis Example: Manufacturing of Raw Material Boron Nitride Particles> The following steps were used to prepare spherical boron nitride particles: A reaction tube (quartz tube) placed in a resistance heating furnace was heated to 1150°C. Nitrogen gas was introduced into the reaction tube after trimethyl borate, thereby introducing trimethyl borate into the reaction tube. Then, ammonia gas was directly introduced into the reaction tube. The molar ratio of ammonia to trimethyl borate (ammonia / trimethyl borate) was 1.8. The trimethyl borate reacted with ammonia to obtain the precursor of boron nitride particles as a white powder.

[0091] The obtained boron nitride particle precursor was added to a boron nitride crucible placed in a resistance heating furnace. Nitrogen and ammonia gases were introduced into the reaction tubes at flow rates of 10 L / min and 15 L / min, respectively. The reaction tubes were heated at 1500 °C for 5 hours to obtain the second precursor.

[0092] The obtained second precursor was added to a boron nitride crucible and heated at 2000°C for 5 hours in an induction furnace under a nitrogen atmosphere to obtain spherical boron nitride particles. The cumulative diameter (D50) of the spherical boron nitride particles was determined by laser diffraction scattering, and the result was 0.62 μm. Additionally, the average sphericality was 0.87.

[0093] <Synthetic Example: Manufacturing of Boron Nitride Particles> The raw material, spherical boron nitride powder, was mixed into 1 L of deionized water at a weight ratio of 10%. The resulting aqueous solution was then subjected to cavitation treatment using a powder suction continuous dissolution and dispersion device (manufactured by Nihon Spindle Manufacturing Co., Ltd., "jet paster", model: JPSS) at a speed of 7200 rpm and 900 treatment cycles. It should be noted that the "number of treatment cycles" refers to the number of times the treated solution passes through the stirring blades, calculated based on the rotational speed (rpm) of the stirring blades and the discharge rate per revolution. After cavitation treatment, the liquid was filtered and dried to obtain spherical boron nitride powder (spherical nano-BN) as boron nitride particles.

[0094] 1s / O 1s Determination of ratio > The obtained spherical boron nitride powder was analyzed using an X-ray photoelectron spectrophotometer (Thermo Fisher Scientific, "K-Alpha X-ray photoelectron spectrometer", Al-X-ray source with monochromator, measurement area: 400 × 200 μm) to determine the spectrum. Background removal of the obtained spectrum was performed using the Shirley method, and the results were then analyzed according to B... 1s Peak intensity and O 1s The peak intensities were calculated to obtain semi-quantitative values, and B was determined. 1s / O 1s Compared to B. 1s The semi-quantitative value calculated from the peak intensity is 48.2, derived from O. 1s The semi-quantitative value calculated from the peak intensity is 1.4, B. 1s / O 1s The ratio is 34.

[0095] <Determination of Particle Size Distribution> In addition, 0.1 g of the obtained spherical boron nitride powder was dispersed in 80 mL of ethanol without homogenization. The volumetric particle size distribution was determined using a laser diffraction scattering particle size distribution analyzer (Beckman Coulter, trade name: LS-13320). The refractive index of ethanol was 1.359, and the refractive index of the boron nitride powder was 1.7. Based on the obtained frequency particle size distribution, the median particle size D50 of the unhomogenized particles was calculated. This D50 was 25 μm.

[0096] ​In addition, 0.01 g of the obtained spherical boron nitride powder was dispersed in 80 mL of ethanol, and then ultrasonically dispersed for 1 minute and 30 seconds using an ultrasonic homogenizer (Nippon Seiki Co., Ltd., trade name: US-300E) set to AMPLITUDE 70-80%. The particle size distribution was then measured using a laser diffraction scattering particle size distribution measuring device (Beckman Coulter, trade name: LS-13320). Based on the obtained volumetric particle size distribution, the median particle size D50 was calculated to be 0.537 μm. The refractive index of ethanol was used as 1.359, and the refractive index of the boron nitride powder was used as 1.7.

[0097] <Determination of Average Circularity> The obtained spherical boron nitride powder was photographed using a scanning electron microscope (SEM) to obtain an image at 10,000x magnification and a resolution of 1280 × 1024 pixels. The image was analyzed using image analysis software (Mountech, trade name: MacView) to calculate the projected area (S) and perimeter (L) of the boron nitride particles. Specifically, according to the following formula: Circularity = 4πS / L² For any 100 randomly selected primary boron nitride particles, their roundness is determined, and the average roundness is calculated based on the average of their roundness values. The average roundness is 0.87.

[0098] [Examples 1-4] <Making of Varnish> Using a container equipped with a heating and cooling jacket and stirring blades, the copolymer and solvent (toluene) prepared above were heated to approximately 60°C and stirred until the copolymer shown in the table dissolved. The amount of toluene used was adjusted so that the concentration of the solid components of the varnish (mass%) was the value shown in Table 2. It should be noted that the concentration of the solid components of the varnish (mass%) is the value calculated as {(copolymer + filler) / (copolymer + filler + toluene)} × 100. Then, 1 part by mass of Perhexyne 25B (manufactured by Nippon Oil Co., Ltd.) as a curing agent was added to 100 parts by mass of the copolymer, dissolved, and stirred to obtain a varnish-like composition.

[0099] Add small amounts of the boron nitride powder (filler) prepared above, in the volume parts shown in the table, to the obtained varnish-like composition, and mix at 1000 rpm for 5 minutes using a planetary vacuum mixer (Thinky ARV310) to obtain the compositions involved in Examples 1 to 4.

[0100] <Evaluation of Dispersion> Based on the description in JIS K5600-2-5:1999, the obtained composition was added dropwise to a fineness tester (manufactured by BYK-Gardner), and a stretched film was formed using the attached scraper. The fracture portion of the film was visually inspected. In the table below, cases where no particles were detected within 100 μm are marked as ○ (good), and cases where particles were detected are marked as × (bad).

[0101] <Preparation of Cured Sheets> The compositions obtained as described above were respectively poured into silicone molds (the frame portion being 7 cm in length, 7 cm in width, and 0.5 mm, 1.0 mm, or 2.0 mm in thickness) placed on Teflon (registered trademark) sheets on a glass plate. After air drying, they were further dried in a vacuum dryer at 60°C for at least 3 hours to obtain uncured sheets. Then, using a press, the Teflon sheets and SUS molds were placed under a load of 5 MPa and subjected to heat treatment at 120°C for 30 minutes, 150°C for 30 minutes, and then 200°C for 120 minutes. The Teflon sheets and SUS molds were then removed to obtain the cured bodies (cured sheets) of Examples 1 to 4.

[0102] Determination of Dielectric Constant and Dielectric Loss (Dielectric Loss Tangent) The dielectric constant and dielectric loss tangent of each cured product of the obtained composition were determined using the split cylindrical resonator method. As the measuring apparatus, an Agilent Technologies 8722ES network analyzer and an EMLabs CR-740 40GHz split cylindrical resonator were used. Samples cut from sheet material, measuring 0.2mm × 30mm × 40mm, were used, and the values ​​were measured at 23°C within the range of 35–42 GHz.

[0103] <Determination of Thermal Conductivity> The thermal conductivity of each cured body of the resulting composition was calculated by multiplying the thermal diffusivity, specific gravity, and specific heat. The cured sample was processed into a 10mm wide × 10mm thick shape, and the thermal diffusivity was determined using the laser flash method. The measurement temperature was set at 23℃. The measuring apparatus used was a xenon flash analyzer (NETZSCH, trade name: LFA447NanoFlash). Specific gravity was determined using Archimedes' method. Specific heat was determined using a differential scanning calorimeter (TA Instruments, trade name: Q2000) under a nitrogen atmosphere, heated from room temperature to 200℃ at a rate of 10℃ / min.

[0104] [Comparative Example 1] The same procedure as in the above embodiments was followed, except that no filler was used to prepare the composition involved in Comparative Example 1. The physical properties were measured in the same manner as described above (hereinafter the same).

[0105] [Comparative Example 2] The procedure was the same as in the above embodiments, except that silica powder (SFP-30M manufactured by Denka Co., Ltd., D50=0.6μm, specific surface area of ​​6.2m²) was used as the filler instead of spherical nano-BN. 2 / g), to prepare the composition involved in Comparative Example 2.

[0106] [Comparative Example 3] The same procedure was followed as in the above examples, except that polybutadiene (B-1000 manufactured by Nippon Soda Co., Ltd.) was used instead of copolymer to prepare the composition involved in Comparative Example 3.

[0107] [Comparative Example 4] The same procedure was followed as in the above examples, except that a liquid epoxy resin (NIPPON STEELC Chemical & Material Co., Ltd. YDF-8170C) was used instead of a copolymer to prepare the composition involved in Comparative Example 4.

[0108] The composition and physical properties of the above embodiments and comparative examples are summarized in the table below.

[0109] [Table 1] [Table 2] Each embodiment exhibits excellent dielectric constant, dielectric loss tangent, thermal conductivity, and dispersibility.

[0110] On the other hand, in Comparative Example 1, which does not contain fillers, the thermal conductivity is inferior to that of the other examples.

[0111] In Comparative Example 2, which uses silica powder instead of spherical nano-BN, the dielectric loss tangent and dielectric constant are inferior to those of the other examples, and aggregates are formed in the composition, resulting in deteriorated thermal conductivity.

[0112] In Comparative Examples 3 and 4, where other resins were used instead of copolymers, the following problems occurred: the composition became non-uniform and deterioration occurred to an extent that could not be measured.

Claims

1. A composition characterized in that, which is a composition containing (a) an olefin-aromatic vinyl compound-aromatic polyene copolymer satisfying all of the following conditions (i) to (iv) and (b) boron nitride particles, (i) the number average molecular weight of the copolymer is 500 or more and less than 100,000; (ii) the aromatic vinyl compound monomer unit is an aromatic vinyl compound having 8 or more and 20 or less carbon atoms, and the content of the aromatic vinyl compound monomer unit is 70% by mass or less; (iii) the aromatic polyene monomer unit is one or more selected from the group consisting of polyenes having 5 or more and 20 or less carbon atoms and having multiple vinyl groups and / or vinylidene groups in the molecule, and the content of the vinyl groups and / or vinylidene groups from the aromatic polyene monomer unit is 1.5 or more and less than 20 per unit number average molecular weight; (iv) the olefin monomer unit is one or more selected from the group consisting of olefins having 2 or more and 20 or less carbon atoms, the content of the olefin monomer unit is 30% by mass or more, and the total of the olefin monomer unit, the aromatic vinyl compound monomer unit, and the aromatic polyene monomer unit is 100% by mass, the volume ratio of the (a) component to the (b) component is in the range of 98 to 15:2 to 85, The value of the medium loss tangent of the cured body of the composition, which was calculated using the split cylinder resonator method, was 2 x 10 -3 Hereinafter, the thermal conductivity of the cured body of the composition measured by a laser flash method at 23°C is 0.6 [W / m·K] or more.

2. The composition of claim 1, wherein, The (b) component contains spherical boron nitride particles.

3. The composition of claim 1 or 2, wherein, the value of the ratio B / O calculated from the peak intensities of the O 1s and B 1s determined by X-ray photoelectron spectroscopy of the (b) component 1s the value of the ratio B / O calculated from the peak intensities of the O 1s and B 1s determined by X-ray photoelectron spectroscopy of the (b) component 1s the value of the ratio B / O calculated from the peak intensities of the O 1s and B 1s determined by X-ray photoelectron spectroscopy of the (b) component 1s / O 1s the value of the ratio B / O calculated from the peak intensities of the O 1s and B 1s determined by X 4. The composition of claim 1 or 2, wherein, The volume-based cumulative diameter (D50) of the (b) component measured by a laser diffraction scattering method without treatment by a homogenizer is 35 μm or less.

5. The composition of claim 2, wherein, The average circularity of the (b) component is 0.80 or more.

6. The composition of claim 1 or 2, wherein, The O content of the (b) component measured by X-ray photoelectron spectroscopy 1s The semi-quantitative value calculated from the peak intensity is 0.6 or more.

7. The composition according to claim 1 or 2, further comprising one or more selected from the group consisting of the following (c) to (g) components, (c) a curing agent; (d) an inorganic filler different from the (b) component; (e) a resin different from the (a) component and selected from one or more of the group consisting of a hydrocarbon-based elastomer, a polyether-based resin, and an aromatic polyene-based resin; (f) a monomer; (g) a solvent.

8. A molded body obtained from the composition according to claim 1.

9. The molded body according to claim 8, which is in the shape of a sheet.

10. A cured body which is a cured body of the molded body according to claim 8.

11. The molded body according to claim 8 or 9, which is an electrically insulating material.

12. A laminate comprising a metal foil and a layer containing the composition according to claim 1.

13. A cured body which is a cured body of the laminate according to claim 12.

14. A single-layer CCL, a multi-layer CCL, a single-layer FCCL, or a multi-layer FCCL substrate comprising the cured body according to claim 10 or 13.

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