Boron nitride material, product with same applied thereto, and method for producing boron nitride material

Abstract

A boron nitride material in one embodiment of the present disclosure contains boron nitride, polydopamine adhered to the boron nitride, and a silicon-containing polymer. The silicon-containing polymer contains a functional group represented by, for example, -SiR3-n(OX)n. n denotes an integer between 1 and 3. X denotes a hydrogen atom, a hydrocarbon group having 1-10 carbon atoms, a moiety bonded to the polydopamine, or a moiety bonded to a silicon atom other than a silicon atom in the functional group. At least one X moiety is a moiety bonded to the polydopamine. R denotes a hydrocarbon group having 1-10 carbon atoms.

Description

Boron nitride material, its application products, and method for manufacturing boron nitride material

[0001] The present disclosure relates to boron nitride materials, applications thereof, and methods for producing boron nitride materials.

[0002] In recent years, in the electronics field, the level of performance required of electronic devices has been increasing in preparation for the expansion of fifth-generation mobile communication systems (5G). For example, 5G uses higher frequency bands to achieve faster communication speeds than previous generations. This means that electronic devices require wiring boards that can handle high frequencies.

[0003] Transmission loss in the transmission path of a wiring board depends on frequency, increasing as the signal frequency increases. Transmission loss depends on the relative dielectric constant and dielectric loss tangent. Therefore, in order to reduce transmission loss of high-frequency signals, the material that makes up the insulating layer of a wiring board must have a low relative dielectric constant and a low dielectric loss tangent.

[0004] Furthermore, high-capacity communications such as 5G use high-frequency bands, resulting in short radio wave transmission distances. This necessitates increased output power from electronic devices. Furthermore, with the realization of high integration and miniaturization, circuit packaging density also increases. Meeting these needs increases the amount of heat generated per unit area of ​​the wiring board. Therefore, wiring boards are required to have high heat dissipation properties. To improve the heat dissipation properties of wiring boards, the material that makes up the insulating layer of the wiring board contains a filler with excellent thermal conductivity, thereby increasing the thermal conductivity of the wiring board.

[0005] Japanese Patent Application Laid-Open No. 2018-043899

[0006] Haeshin Lee, Shara M. Dellatore, William M. Miller, Phillip B. Messersmith, Science, 2007, vol. 318, 426-430Heng Shen, Jing Guo, Hao Wang, Ning Zhao, Jian Xu, ACS Appl. Mater. Interfaces, 2015, 7, 5701-5708

[0007] In the prior art, it is desirable to improve the heat resistance of fillers.

[0008] The boron nitride material of the present disclosure comprises: boron nitride; polydopamine attached to the boron nitride; and a silicon-containing polymer.

[0009] According to the present disclosure, the heat resistance of the filler can be improved.

[0010] FIG. 1 is a diagram showing a schematic configuration of a boron nitride material in embodiment 1. FIG. 2 is a flowchart showing an example of a method for producing a boron nitride material in embodiment 1. FIG. 3 is a diagram showing a schematic configuration of a resin composition in embodiment 4. FIG. 4 is a cross-sectional view of a resin-coated film in embodiment 6. FIG. 5 is a cross-sectional view of a resin-coated metal foil in embodiment 7. FIG. 6 is a cross-sectional view of a metal-clad laminate in embodiment 8. FIG. 7 is a cross-sectional view of a wiring board in embodiment 9. FIG. 8 is a diagram showing an example of a transmission electron microscope (TEM) image of a cross-section perpendicular to the thickness direction of a particle of the boron nitride material in embodiment 1.

[0011] (Findings that form the basis of the present disclosure) Increasing the filler content in a resin composition to improve the heat dissipation of a wiring board impairs mechanical properties such as flexibility, and the insulating layer tends to become brittle. This is thought to be due to the aggregation of the filler in the resin composition. Chemical modification of the filler surface is effective in improving dispersibility while suppressing the aggregation of the filler.

[0012] Boron nitride is a material with high thermal conductivity, excellent heat dissipation, and excellent electrical insulation. Therefore, boron nitride has recently attracted attention as a filler for the insulating layer of wiring boards (see, for example, Patent Document 1). However, the amount of functional groups present on the surface of boron nitride particles is small, and most of the surface is inactive. Therefore, it has been difficult to improve the dispersibility of boron nitride particles in resin compositions by directly treating the surface of the particles using methods such as silane coupling.

[0013] Here, dopamine-containing proteins secreted from the byssus glands of the blue mussel, a type of bivalve, exhibit stable adhesive strength even in seawater and are known as natural adhesives. According to Non-Patent Document 1, when a substrate is immersed in an aqueous dopamine solution, a thin film of polydopamine is formed on the surface of the substrate due to the autoxidative polymerization of dopamine. Non-Patent Document 2 describes that by utilizing this property to coat boron nitride with polydopamine, the dispersibility of boron nitride as a filler is improved.

[0014] Incidentally, wiring boards typically undergo a solder reflow process when electronic components are mounted on the board. Therefore, the filler must have high heat resistance. However, polydopamine has many hydroxyl groups, making it hydrophilic and prone to adsorbing moisture from the atmosphere. Therefore, when boron nitride with polydopamine attached is used as a filler, the moisture adsorbed on the surface of the polydopamine can evaporate due to heating during the solder reflow process, resulting in the formation of air bubbles. These air bubbles can accumulate inside the wiring board and cause various problems.

[0015] The present inventors have conducted extensive research into improving the heat resistance of boron nitride, which has resulted in the development of the boron nitride material disclosed herein.

[0016] A boron nitride material according to a first aspect of the present disclosure includes boron nitride, polydopamine attached to the boron nitride, and a silicon-containing polymer, and the heat resistance of the boron nitride material can be improved.

[0017] In a second aspect of the present disclosure, for example, in the boron nitride material according to the first aspect, the silicon-containing polymer may be attached to the polydopamine. This configuration can improve the heat resistance of the boron nitride material.

[0018] In a third aspect of the present disclosure, for example, in the boron nitride material according to the first or second aspect, the silicon-containing polymer may include a first side chain containing a silicon atom and an oxygen atom, and may be bonded to the polydopamine via the silicon atom and the oxygen atom. This configuration can improve the heat resistance of the boron nitride material.

[0019] In a fourth aspect of the present disclosure, for example, in the boron nitride material according to any one of the first to third aspects, the silicon-containing polymer may include a second side chain including at least one bond selected from the group consisting of a carbon-carbon double bond and a carbon-carbon triple bond. With this configuration, when the boron nitride material is used as a filler, the heat dissipation properties of the filler are improved.

[0020] In a fifth aspect of the present disclosure, for example, in the boron nitride material according to the fourth aspect, the second side chain may consist solely of a chain structure. With this configuration, when the boron nitride material is used as a filler, the heat dissipation property of the filler is improved.

[0021] In a sixth aspect of the present disclosure, for example, in the boron nitride material according to any one of the first to fifth aspects, the silicon-containing polymer may include a main chain containing at least one unit selected from the group consisting of a styrene unit, a butadiene unit, an ethylene unit, and a siloxane unit, thereby improving the heat resistance of the boron nitride material.

[0022] In a seventh aspect of the present disclosure, for example, in the boron nitride material according to the sixth aspect, the silicon-containing polymer may include a main chain containing the butadiene unit, thereby improving the heat resistance of the boron nitride material.

[0023] In an eighth aspect of the present disclosure, for example, in the boron nitride material according to the seventh aspect, the silicon-containing polymer may include a copolymer containing the styrene unit and the butadiene unit, thereby further improving the heat resistance of the boron nitride material.

[0024] In a ninth aspect of the present disclosure, for example, in the boron nitride material according to any one of the first to eighth aspects, the silicon-containing polymer is -SiR 3-n (OX) n wherein n is an integer of 1 to 3, and X represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a moiety bonded to the polydopamine, or a moiety bonded to a silicon atom other than the silicon atom of the functional group. At least one of the X's is a moiety bonded to the polydopamine. R represents a hydrocarbon group having 1 to 10 carbon atoms. The above configuration further improves the heat resistance of the boron nitride material.

[0025] In a tenth aspect of the present disclosure, for example, in the boron nitride material according to the ninth aspect, the silicon-containing polymer may be represented by the following formula (1) containing a plurality of repeating units: In the formula (1), a and d are numbers equal to or greater than 0, and b and c are numbers greater than 0. However, in the formula (1), the order of the multiple repeating units is arbitrary. With the above configuration, the heat resistance of the boron nitride material is further improved.

[0026] In an eleventh aspect of the present disclosure, for example, in the boron nitride material according to the tenth aspect, the formula (1) may satisfy 0.050≦c / (b+c+d). With this configuration, the heat resistance of the boron nitride material is further improved.

[0027] A filler according to a twelfth aspect of the present disclosure includes the boron nitride material according to any one of aspects 1 to 11. With the above configuration, the heat resistance of the filler can be improved.

[0028] A resin composition according to a thirteenth aspect of the present disclosure includes the filler according to the twelfth aspect. According to the thirteenth aspect, it is possible to provide a resin composition that exhibits a low dielectric tangent and excellent heat resistance.

[0029] A prepreg according to a fourteenth aspect of the present disclosure includes the resin composition of the thirteenth aspect or a semi-cured product of the resin composition.

[0030] A resin-coated film according to a fifteenth aspect of the present disclosure comprises: a resin layer containing the resin composition of the thirteenth aspect or a semi-cured product of the resin composition; and a support film.

[0031] A resin-coated metal foil according to a sixteenth aspect of the present disclosure includes: a resin layer containing the resin composition of the thirteenth aspect or a semi-cured product of the resin composition; and a metal foil.

[0032] A metal-clad laminate according to a seventeenth aspect of the present disclosure includes: an insulating layer containing a cured product of the resin composition according to the thirteenth aspect or a cured product of the prepreg according to the fourteenth aspect; and a metal foil.

[0033] A wiring board according to an eighteenth aspect of the present disclosure includes: an insulating layer including a cured product of the resin composition according to the thirteenth aspect or a cured product of the prepreg according to the fourteenth aspect; and wiring.

[0034] According to the fourteenth to eighteenth aspects, various application products suitable for high frequencies can be provided.

[0035] A method for producing a boron nitride material according to a nineteenth aspect of the present disclosure includes preparing a substrate containing boron nitride and polydopamine attached to a surface of the boron nitride, and contacting the substrate with a silicon-containing polymer. This method allows the production of a boron nitride material with excellent heat resistance.

[0036] In a twentieth aspect of the present disclosure, for example, in the method for producing a boron nitride material according to the nineteenth aspect, the silicon-containing polymer may have a number average molecular weight of 1200 or more. This configuration improves the heat resistance of the boron nitride material.

[0037] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0038] First Embodiment Hereinafter, a first embodiment will be described with reference to FIGS. 1 and 2. FIG.

[0039] 1 is a diagram showing a schematic configuration of a boron nitride material 10 in embodiment 1. The boron nitride material 10 includes boron nitride 1, polydopamine 2 attached to the boron nitride 1, and a silicon-containing polymer 3.

[0040] Boron nitride material 10 contains silicon-containing polymer 3 in addition to polydopamine 2, and polydopamine 2 is attached to boron nitride 1, thereby suppressing adsorption of atmospheric moisture to polydopamine 2. In addition, silicon-containing polymer 3 is less likely to evaporate when heated than silicon-containing low molecular weight compounds such as methacrylsilane. As a result, boron nitride material 10 is less likely to generate bubbles when heated in the solder reflow process, and as a result, has high heat resistance. In this disclosure, "silicon-containing low molecular weight compound" refers to an organosilicon compound with a molecular weight of less than 1,200.

[0041] Polydopamine 2 and silicon-containing polymer 3 may be attached to the surface of boron nitride 1. Specifically, polydopamine 2 may be attached to the surface of boron nitride 1 by chemically modifying the surface of boron nitride 1 with polydopamine 2. Polydopamine 2 may cover at least a portion of the surface of boron nitride 1. Polydopamine 2 may cover the entire surface of boron nitride 1, or may cover only a portion of the surface of boron nitride 1. Silicon-containing polymer 3 may be attached to polydopamine 2. Silicon-containing polymer 3 may be attached to polydopamine 2 attached to the surface of boron nitride 1. The attachment of polydopamine 2 to the surface of boron nitride 1 and the attachment of silicon-containing polymer 3 to polydopamine 2 can be confirmed, for example, by a transmission electron microscope (TEM). Figure 8 is an example of a transmission electron microscope (TEM) image (magnification: 50,000x) of a cross section perpendicular to the thickness direction of a particle of boron nitride material 10. The TEM image in Figure 8 was obtained by TEM observation of a thin-sectioned sample of a resin composition produced by kneading particles of boron nitride material 10 with polyphenylene ether resin. As shown in Figure 8, the TEM image confirms that polydopamine 2 is attached to boron nitride 1, and that silicon-containing polymer 3 is attached to polydopamine 2.

[0042] [Boron Nitride] As boron nitride 1, hexagonal boron nitride (h-BN) having a graphite-type layer structure, diamond-type cubic boron nitride (c-BN), amorphous boron nitride (a-BN), and the like can be used. h-BN is particularly useful because it can be synthesized relatively easily and has excellent thermal conductivity, electrical insulation, chemical stability, and heat resistance. Boron nitride particles can be used as boron nitride 1. Boron nitride particles are usually white. The shape of the boron nitride particles is not particularly limited. The shape of the boron nitride particles may be, for example, scale-like, spherical, oval-spherical, rod-like, or the like.

[0043] The average particle size of the boron nitride particles is not particularly limited. The average particle size of the boron nitride particles may be, for example, 0.05 μm or more and 100 μm or less, or 0.1 μm or more and 50 μm or less. In the present disclosure, the average particle size of the boron nitride particles refers to the median diameter. The median diameter refers to the particle size (d50) when the cumulative volume in the volume-based particle size distribution is equal to 50%. The volume-based particle size distribution is measured, for example, using a laser diffraction measurement device.

[0044] [Polydopamine] Polydopamine 2 is a dopamine polymer and may have, for example, one or both of the two repeating units represented by the following formula (2): In the following formula (2), the indoline skeleton may be an indole skeleton.

[0045]

[0046] In the above formula (2), n is an integer of 1 or more. In the above formula (2), n may be an integer of 2 or more.

[0047] The polydopamine 2 may be in the form of a thin film on the surface of the boron nitride 1 particle. The thickness of the polydopamine 2 thin film is, for example, 1 nm to 300 nm. The polydopamine 2 thin film covers at least a portion of the surface of the boron nitride 1 particle. The polydopamine 2 thin film may cover the entire surface of the boron nitride 1 particle, as exemplified in FIG. 1 .

[0048] The adhesion of polydopamine to boron nitride 1 can be confirmed by the fact that the surface of the boron nitride 1 particles is colored black-brown.

[0049] In this specification, even if some of the functional groups derived from dopamine in a polymer have changed due to bonding with other substances, the polymer is still considered to be a "polydopamine." One example of the change in functional group is the loss of hydroxyl groups that accompanies dehydration condensation between the hydroxyl groups of polydopamine and the hydroxyl groups of other substances. This dehydration condensation is a typical example of a chemical reaction that results in bonding with the silicon-containing polymer 3, which will be described below.

[0050] [Silicon-Containing Polymer] The structure of the silicon-containing polymer 3 is not particularly limited as long as it is a polymer containing silicon atoms, but it may, for example, contain a main chain and side chains branching from the main chain. The silicon-containing polymer 3 may contain multiple side chains. The main chain may contain a first main chain composed of carbon atoms bonded to each other. The first main chain may have the effect of preventing the surface of the boron nitride 1 from being excessively hydrophilic. The silicon-containing polymer 3 may contain a side chain containing a silicon atom in addition to the first main chain.

[0051] The silicon-containing polymer 3 may include a first side chain having a silicon atom and an oxygen atom. The silicon-containing polymer 3 may be bonded to the polydopamine 2 via the silicon atom and the oxygen atom. More specifically, the silicon-containing polymer 3 may include an oxygen atom bonded to the silicon atom and the polydopamine 2. The silicon-containing polymer 3 may be bonded to the benzene ring of the polydopamine 2 via an oxygen atom, for example. This bond may be formed at least via dehydration condensation. As in this example, the bond may be a chemical bond such as a covalent bond.

[0052] Silicon-containing polymer 3 is —SiR 3-n (OX) nwhere n is an integer of 1 to 3, and X represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a bonding moiety bonded to polydopamine, or a bonding moiety bonded to a silicon atom other than the silicon atom of the functional group. The bonding moiety X can also be represented by a single bond (-). The hydrocarbon group having 1 to 10 carbon atoms is, for example, an alkyl group having 1 to 10 carbon atoms, particularly 1 to 3 carbon atoms. At least one of the X's is a bonding moiety bonded to polydopamine 2. R represents a hydrocarbon group having 1 to 10 carbon atoms. When the silicon-containing polymer 3 contains a bonding moiety bonded to another silicon atom, the silicon-containing polymer 3 contains a siloxane unit represented by Si—O—Si. The silicon-containing polymer 3 may also contain a second main chain composed of siloxane units.

[0053] -SiR 3-n (OX) n In the functional group represented by the formula: R may be an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0054] The alkyl group having 1 to 10 carbon atoms may have any of a linear, cyclic, or branched structure. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, an α-naphthyl group, and a β-naphthyl group.

[0055] Silicon-containing polymer 3 is -SiR 3-n (OX) n and X includes a bond bonded to another silicon atom, the silicon-containing polymer 3 includes a siloxane unit represented by Si—O—Si. The silicon-containing polymer 3 may include a second main chain formed of siloxane units. The silicon-containing polymer 3 having such a structure may have a network structure in which the siloxane units (Si—O—Si) are spread out in a mesh-like pattern.

[0056] The silicon-containing polymer 3 may include a second side chain having at least one bond selected from the group consisting of a carbon-carbon double bond and a carbon-carbon triple bond. With this structure, the carbon-carbon double bond or carbon-carbon triple bond reacts with the reactive residue of the resin of the insulating layer to form a bond, thereby improving the adhesion between the boron nitride material 10 and the resin. This reduces the thermal resistance at the interface between the boron nitride material 10 and the resin, improving the thermal conductivity of the insulating layer. This in turn improves the heat dissipation of the wiring board. Examples of carbon-carbon double bonds include vinyl groups, methallyl groups, and acryloyl groups. The silicon-containing polymer 3 may contain one or more groups selected from these. From the viewpoint of ease of reactivity, the carbon-carbon double bond is preferably a vinyl group. Examples of reactive residues of the resin of the insulating layer include vinyl groups, methallyl groups, and acryloyl groups. Examples of carbon-carbon triple bonds include ethynyl groups and propargyl groups. The silicon-containing polymer 3 may contain one or more selected from these. Examples of reactive residues in the resin of the insulating layer include ethynyl groups and propargyl groups. At least one bond selected from the group consisting of a carbon-carbon double bond and a carbon-carbon triple bond may be located at the end of the second side chain. The second side chain may consist solely of a chain structure.

[0057] From the viewpoint of avoiding deterioration due to oxidation, it is desirable that the content of carbon-carbon double bonds and carbon-carbon triple bonds present inside silicon-containing polymer 3 be small.

[0058] The silicon-containing polymer 3 may further include a side chain other than the first side chain and the second side chain. The side chain other than the first side chain and the second side chain may have, for example, a cyclic structure. The cyclic structure of the side chain may be, for example, an aryl group.

[0059] Silicon-containing polymer 3 may contain a main chain having at least one unit selected from the group consisting of a styrene unit, a butadiene unit, an ethylene unit, and a siloxane unit. This configuration improves the hydrophobicity of silicon-containing polymer 3, thereby improving the heat resistance of boron nitride material 10.

[0060] The silicon-containing polymer 3 may contain a main chain having a butadiene unit. According to the above configuration, the hydrophobicity of the silicon-containing polymer 3 is further improved, and the heat resistance of the boron nitride material 10 is further improved.

[0061] Silicon-containing polymer 3 may contain a copolymer having a styrene unit and a butadiene unit. According to the above configuration, the hydrophobicity of silicon-containing polymer 3 is further improved, and therefore the heat resistance of boron nitride material 10 is further improved.

[0062] The silicon-containing polymer 3 may be represented by the following formula (1) containing a plurality of repeating units: According to the above configuration, the heat resistance of the boron nitride material 10 is further improved.

[0063]

[0064] In the above formula (1), a and d represent numbers of 0 or more, and b and c represent numbers greater than 0. However, in the above formula (1), the order of the multiple repeating units is arbitrary. 3-n (OX) n The functional group represented by is as explained above. In the portion d of the above formula (1), the bond represented by the wavy line means either trans or cis, or a mixture of both.

[0065] In the above formula (1), the silicon-containing polymer 3 may satisfy 0≦a≦500, 1≦b≦500, 1≦c≦500, and 0≦d≦500, or may satisfy 5≦a≦300, 5≦b≦300, 1≦c≦100, and 5≦d≦300.

[0066] In the above formula (1), the silicon-containing polymer 3 may satisfy 5≦a≦100, 5≦b≦100, 1≦c≦80, and 5≦d≦100, or may satisfy 5≦a≦20, 5≦b≦50, 1≦c≦60, and 5≦d≦40.

[0067] In the above formula (1), c represents the repeating number of butadiene units having silicon and oxygen in their side chains. (b + c + d) represents the sum of the butadiene units having repeating number b, the butadiene units having repeating number c, and the butadiene units having repeating number d. In the above formula (1), the silicon-containing polymer 3 may satisfy 0.050≦c / (b + c + d). In other words, in the above formula (1), the value calculated by 100×{c / (b + c + d)} may be 5.0% or more. This configuration further improves the heat resistance of the boron nitride material 10. Furthermore, the dielectric properties of the boron nitride material 10 are also improved. In the above formula (1), the value calculated by 100×{c / (b + c + d)} may be 15.0% or more, or may be 17.7% or more. The value calculated by 100 × {c / (b+c+d)} may be 30.0% or more, or may be 50.0% or more. The upper limit of the value calculated by 100 × {c / (b+c+d)} is, for example, 80%.

[0068] [Method for Manufacturing Boron Nitride Material] Next, a method for manufacturing the above-described boron nitride material 10 will be described.

[0069] 2 is a flowchart showing an example of a method for producing a boron nitride material according to Embodiment 1. The method for producing a boron nitride material 10 includes preparing a substrate containing boron nitride 1 and polydopamine 2 attached to the surface of the boron nitride 1 (step S1), and contacting the substrate with a silicon-containing polymer 3 (step S2).

[0070] A substrate containing boron nitride 1 and polydopamine 2 attached to the surface of the boron nitride 1 can be obtained by utilizing the autooxidative polymerization of dopamine to attach polydopamine 2 to the surface of the boron nitride 1. Specifically, a dopamine solution is brought into contact with particles of boron nitride 1, and the dopamine is oxidatively polymerized, thereby attaching polydopamine 2 to the surface of the particles of boron nitride 1 and forming a thin film of polydopamine 2.

[0071] A dopamine solution can be obtained by adding dopamine hydrochloride to a Tris-HCl solution whose pH has been adjusted to 8.5 and stirring the mixture. The concentration of the dopamine solution is not particularly limited and may be, for example, in the range of 0.01 mg / mL to 30 mg / mL. The pH of the dopamine solution may be in the range of 6 to 11, or may be in the range of 8 to 10. The pH of the dopamine solution can be adjusted by adding a Tris-HCl solution or the like. The temperature of the dopamine solution during oxidative polymerization is, for example, 10°C to 100°C. The polymerization time is, for example, 1 hour to 48 hours. The thickness of the polydopamine 2 thin film is, for example, 1 nm to 300 nm. The thickness of the polydopamine 2 thin film can be controlled by the polymerization time.

[0072] Here, the silicon-containing polymer 3 represented by the above formula (1) is represented by the following formula (3) before being bound to the polydopamine 2.

[0073]

[0074] In the above formula (3), R 1 and R 2 are each independently a hydrocarbon group having 1 to 10 carbon atoms. m is an integer of 1 to 3. a and d are numbers of 0 or more, and b and c are numbers greater than 0.

[0075] In the above formula (3), R 1 and R 2 may each independently represent an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0076] The alkyl group having 1 to 10 carbon atoms and the aryl group having 6 to 10 carbon atoms are represented by —SiR 3-n (OX) n However, in the above formula (3), the alkyl group having 1 to 10 carbon atoms is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. 1 and R 2 are each independently preferably a straight-chain alkyl group, more preferably a methyl group or an ethyl group.

[0077] In the high-frequency band ranging from GHz to THz, the dielectric loss tangent of a wiring board material is highly dependent on the orientation polarization of the organic molecules contained in the wiring board material. Therefore, the hydroxyl groups of polydopamine can increase the dielectric loss tangent. However, the silicon-containing polymer represented by the above formula (3) acts on the hydroxyl groups of polydopamine to bond with it. The silicon-containing polymer after bonding is represented by the above formula (1). In boron nitride material 10, the number of hydroxyl groups of polydopamine is reduced, thereby suppressing the increase in the dielectric loss tangent of boron nitride material 10.

[0078] The silicon-containing polymer represented by formula (3) can be obtained via the reaction shown in the following scheme. Specifically, a styrene-butadiene copolymer represented by formula (4) and an organosilicon compound represented by formula (5) are hydrosilylated in the presence of a platinum compound-containing catalyst, preferably in the presence of a platinum compound-containing catalyst and a co-catalyst. This allows the silicon-containing polymer represented by formula (3) to be obtained.

[0079]

[0080] The styrene-butadiene copolymer represented by the formula (4) can be synthesized by a known method such as emulsion polymerization or solution polymerization using butadiene and styrene as raw material monomers. The styrene-butadiene copolymer represented by the formula (4) can also be obtained as a commercially available product. Examples of commercially available products include Ricon 100, Ricon 181, and Ricon 184 (all manufactured by Cray Valley Chemical Industry Co., Ltd.), L-SBR-820 and L-SBR-841 (all manufactured by Kuraray Co., Ltd.), and 1,2-SBS (all manufactured by Nippon Soda Co., Ltd.).

[0081] Examples of the organosilicon compound represented by the above formula (5) include trimethoxysilane, methyldimethoxysilane, dimethylmethoxysilane, triethoxysilane, methyldiethoxysilane, and dimethylethoxysilane.

[0082] The value of c is maintained before and after the silicon-containing polymer is bonded to polydopamine 2. That is, the value of c in the above formula (3) is equal to the value of c in the above formula (1). Therefore, the silylation rate calculated by 100 × {c / (b + c + d)} in the above formula (3) can be regarded as the silylation rate calculated by 100 × {c / (b + c + d)} in the above formula (1).

[0083] The number average molecular weight of the silicon-containing polymer before bonding to polydopamine 2 may be 1200 or more, or may be 5000 or more. According to the above configuration, the hydrophobicity of the silicon-containing polymer 3 is improved, thereby improving the heat resistance of the boron nitride material 10. There is no particular limitation on the upper limit of the number average molecular weight of the silicon-containing polymer before bonding to polydopamine. The upper limit of the number average molecular weight of the silicon-containing polymer before bonding to polydopamine 2 is, for example, 10000 or less. In the present disclosure, the number average molecular weight is the number average molecular weight calculated in terms of polystyrene using gel permeation chromatography (GPC).

[0084] In step S2, a silicon-containing polymer 3 may be bonded to polydopamine 2. For example, when the silicon-containing polymer before bonding to polydopamine 2 is represented by formula (3) above, the silicon-containing polymer 3 can be bonded to polydopamine 2 by a silane coupling reaction. The silane coupling reaction proceeds as follows: First, the silicon-containing polymer represented by formula (3) above is hydrolyzed to generate silanol groups (Si—OH). Next, the silanol groups are partially bonded to polydopamine 2 by dehydration condensation with the hydroxyl groups of polydopamine 2. At this time, the silicon-containing polymer has siloxane units (Si—O—Si) formed by dehydration condensation. Subsequent heat treatment promotes dehydration condensation, and the silicon-containing polymer 3 bonds to the benzene rings of polydopamine 2 via silicon atoms and oxygen atoms.

[0085] Second Embodiment A heat dissipating gap filler according to this embodiment includes the boron nitride material 10 of the first embodiment.

[0086] In this disclosure, a thermal dissipation gap filler is a filler that is applied to electronic components such as substrate materials to fill air pockets or gaps, thereby dissipating heat from the electronic components. The thermal dissipation gap filler is a curing type thermal paste that hardens from a paste state into a sheet state. The thermal dissipation gap filler according to this embodiment can improve the heat resistance of the filler.

[0087] The heat dissipation gap filler according to this embodiment can be produced by, for example, mixing the boron nitride material 10 according to the first embodiment with an epoxy resin or a silicone-based resin, or a non-silicone acrylic resin or a ceramic-based resin.

[0088] Third Embodiment A filler for thermal grease according to this embodiment includes the boron nitride material 10 according to the first embodiment.

[0089] In this disclosure, the term "thermal grease filler" refers to a filler used in thermal grease. Thermal grease is a non-hardening thermal paste that is applied to electronic components such as circuit board materials to fill air pockets or gaps, thereby dissipating heat from the electronic components. The thermal grease filler according to this embodiment can improve the heat resistance of the filler.

[0090] The filler for thermal grease according to this embodiment can be produced, for example, by kneading the boron nitride material 10 according to the first embodiment with an epoxy resin or a silicone-based resin, or a non-silicone acrylic resin or a ceramic-based resin.

[0091] 3 is a diagram showing a schematic configuration of a resin composition 20 according to an embodiment 4. The resin composition 20 includes, for example, a filler 22 and a curable resin 24.

[0092] Filler 22 includes boron nitride material 10 described in embodiment 1. According to this embodiment, it is possible to provide resin composition 20 that exhibits a low dielectric tangent and excellent heat resistance. As filler 22, boron nitride material 10 alone may be used, or other filler materials such as silica particles may be used in combination with boron nitride material 10.

[0093] Examples of the curable resin 24 include epoxy resin, cyanate ester compound, maleimide compound, phenol resin, acrylic resin, polyamide resin, polyamideimide resin, thermosetting polyimide resin, polyphenylene ether resin, etc. As the curable resin 24, one or a combination of two or more selected from these can be used.

[0094] The resin composition 20 may contain other components, such as a curing agent, a flame retardant, an ultraviolet absorber, an antioxidant, a reaction initiator, a silane coupling agent, a fluorescent brightener, a photosensitizer, a dye, a pigment, a thickener, a lubricant, an antifoaming agent, a dispersant, a leveling agent, a gloss agent, an antistatic agent, a polymerization inhibitor, and an organic solvent. If necessary, one or a combination of two or more selected from these may be used.

[0095] (Embodiment 5) A prepreg according to embodiment 5 comprises the resin composition 20 of embodiment 4 shown in Figure 3 or a semi-cured product thereof, and a fibrous base material. The fibrous base material is present in the matrix of the resin composition 20 or a semi-cured product thereof. The prepreg is a composite material of the resin composition 20 and the fibrous base material. According to this embodiment, a prepreg suitable for high-frequency wiring boards can be provided.

[0096] In this embodiment, the semi-cured product refers to a material in a partially cured state to the extent that the resin composition 20 can be further cured. In other words, the semi-cured product is a material in a semi-cured state of the resin composition 20. For example, when the resin composition 20 is heated, its viscosity gradually decreases. As heating continues, curing begins, and the viscosity gradually increases. In such a case, the semi-cured state refers to the state of the resin composition 20 from the point when the viscosity starts to increase until the resin composition 20 is completely cured.

[0097] The fibrous substrate may be any known material used in various types of laminates for electrical insulating materials, such as glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper.

[0098] The resin composition 20 is impregnated into the fibrous base material by a process such as immersion or coating. The fibrous base material impregnated with the resin composition 20 is heated under predetermined heating conditions to obtain the prepreg in the uncured or semi-cured state according to the present embodiment.

[0099] Sixth Embodiment Fig. 4 is a cross-sectional view of a resin-coated film 30 in a sixth embodiment. The resin-coated film 30 comprises a resin layer 32 containing the resin composition 20 or a semi-cured product thereof, and a support film 34. According to this embodiment, a resin-coated film 30 suitable for an insulating layer can be provided. The resin layer 32 is supported by the support film 34. In the example of Fig. 4, the support film 34 is disposed on the surface of the resin layer 32. However, another layer such as an adhesive layer may be provided between the resin layer 32 and the support film 34.

[0100] The resin layer 32 contains the resin composition 20 of the fourth embodiment shown in FIG. 3 or a semi-cured product thereof, and may or may not contain a fibrous base material. The fibrous base material may be the same material as the fibrous base material of the prepreg. The resin layer 32 hardens and transforms into an insulating layer. An example of such an insulating layer is the insulating layer of a wiring board.

[0101] Any support film used for a resin-coated film can be used without limitation as the support film 34. Examples of the support film 34 include resin films such as polyester films and polyethylene terephthalate films.

[0102] Seventh Embodiment Fig. 5 is a cross-sectional view of a resin-coated metal foil 40 according to a seventh embodiment. The resin-coated metal foil 40 includes a resin layer 42 containing the resin composition 20 or a semi-cured product thereof, and a metal foil 44. The resin layer 42 is supported by the metal foil 44. This embodiment can provide a resin-coated metal foil 40 suitable for electronic circuit components such as wiring boards. In the example of Fig. 5, the metal foil 44 is disposed on the surface of the resin layer 42. However, another layer, such as an adhesive layer, may be disposed between the resin layer 42 and the metal foil 44.

[0103] The resin layer 42 contains the resin composition of the fourth embodiment shown in FIG. 3 or a semi-cured product thereof, and may or may not contain a fibrous base material. The fibrous base material may be the same material as the fibrous base material of the prepreg. The resin layer 42 hardens and transforms into an insulating layer. An example of such an insulating layer is the insulating layer of a wiring board.

[0104] There are no limitations on the metal foil 44. Metal foils with resins and metal foils used in metal-clad laminates can be used. Examples of metal foils include copper foil and aluminum foil.

[0105] Eighth Embodiment Fig. 6 is a cross-sectional view of a metal-clad laminate 50 according to an eighth embodiment. The metal-clad laminate 50 includes an insulating layer 52 and at least one metal foil 54. According to this embodiment, a metal-clad laminate 50 suitable for wiring boards can be provided. The insulating layer 52 includes a cured product of the resin composition 20 of the fourth embodiment shown in Fig. 3 or a cured product of the prepreg of the fifth embodiment. The metal foil 54 is disposed on the surface of the insulating layer 52. In this embodiment, a metal foil 54 is disposed on each of the front and back surfaces of the insulating layer 52.

[0106] The metal-clad laminate 50 is typically manufactured using the prepreg of the fifth embodiment. For example, 1 to 20 prepregs are stacked to form a laminate. Metal foil is placed on one or both sides of the prepreg laminate, and the laminate is heated and pressed to obtain the metal-clad laminate 50. Examples of the metal foil 54 include copper foil and aluminum foil.

[0107] The molding conditions for producing the metal-clad laminate 50 may be, for example, the molding conditions for producing laminates for electrical insulating materials and multilayer boards.

[0108] (Embodiment 9) Fig. 7 is a cross-sectional view of wiring board 60 in embodiment 9. Wiring board 60 includes insulating layer 62 and wiring 64. According to this embodiment, it is possible to provide wiring board 60 suitable for high frequencies. Insulating layer 62 includes a cured product of resin composition 20 of embodiment 4 shown in Fig. 3 or a cured product of the prepreg of embodiment 5. Wiring 64 is supported by insulating layer 62. More specifically, wiring 64 is disposed on insulating layer 62. Wiring 64 can be formed by partially removing the metal foil.

[0109] 6 is patterned by a method such as etching to obtain a wiring board 60 having wiring 64 forming a circuit provided on the surface of an insulating layer 62. That is, the wiring board 60 is obtained by partially removing the metal foil 54 on the surface of the metal-clad laminate 50 so as to form a circuit.

[0110] A new laminate may be formed by laminating the prepreg of embodiment 5 on at least one surface of wiring board 60 and then applying heat and pressure. A multilayer wiring board can be obtained by patterning the metal foil on the surface of the obtained laminate to form wiring.

[0111] The present disclosure will be specifically described below with reference to examples. The examples are intended to illustrate the present disclosure and are not intended to limit the scope of the present disclosure.

[0112] Example 1 h-BN (manufactured by Denka, product number: SGP, average particle size: 18 μm) was used as boron nitride. Dopamine hydrochloride was added to a Tris-HCl solution adjusted to pH 8.5 and stirred to obtain a dopamine solution (concentration: 23 mg / mL). 4.5 g of boron nitride was added to the obtained dopamine solution. The solution temperature was set to 80°C, and the mixture was stirred for 24 hours using a magnetic stirrer. A solid was then obtained by filtration. The obtained solid was washed with water and then dried. This resulted in boron nitride with polydopamine attached (hereinafter referred to as polydopamine-coated boron nitride for convenience). The attachment of polydopamine was confirmed by the fact that the surfaces of the boron nitride particles were colored black-brown.

[0113] A styrene-butadiene copolymer represented by the above formula (4) (manufactured by RICON Corporation, product number: RICON100, b+c=44) and an organosilicon compound represented by the above formula (5) (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1040, m=3, R 1 = ethyl group) was hydrosilylated in the presence of a platinum compound-containing catalyst. This resulted in the production of the silicon-containing polymer of Example 1 represented by the above formula (3). The silicon-containing polymer of Example 1 was a compound represented by the above formula (3) where a = 11, b = 26, c = 4, d = 32, m = 3, R 1 = ethyl group. The silylation rate of the silicon-containing polymer was 6.5%. In this example, the silylation rate was measured by nuclear magnetic resonance spectroscopy (NMR) using -SiR 2 3-m (OR 1 ) mThis was confirmed by calculating the ratio of the terminals with and without functional groups introduced, as shown by the formula: Next, 1 g of silicon-containing polymer was dissolved in toluene to obtain a toluene solution with a concentration of 100 mg / mL. 2 g of polydopamine-coated boron nitride was added to the obtained solution. The solution temperature was set to 100°C, and the mixture was stirred with a magnetic stirrer for 3 hours. A solid was then obtained by filtration. The obtained solid was washed with a toluene solution and then dried. This yielded particles of the boron nitride material of Example 1.

[0114] Example 2 A styrene-butadiene copolymer represented by the above formula (4) (manufactured by RICON Corporation, product number: RICON100, b+c=44) and an organosilicon compound represented by the above formula (5) (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1040, m=3, R 1 = ethyl group) was hydrosilylated in the presence of a platinum compound-containing catalyst. This resulted in the production of the silicon-containing polymer of Example 2, which is represented by the above formula (3). The silicon-containing polymer of Example 2 is a compound represented by the above formula (3) in which a = 11, b = 23, c = 8, d = 31, m = 3, R 1 = ethyl group. The silylation rate of the silicon-containing polymer was 12.9%. Except for this, particles of the boron nitride material of Example 2 were obtained in the same manner as in Example 1.

[0115] Example 3 A styrene-butadiene copolymer represented by the above formula (4) (manufactured by RICON Corporation, product number: RICON100, b+c=44) and an organosilicon compound represented by the above formula (5) (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1040, m=3, R 1 = ethyl group) was hydrosilylated in the presence of a platinum compound-containing catalyst. This resulted in the production of the silicon-containing polymer of Example 3, which is represented by the above formula (3). The silicon-containing polymer of Example 3 is a compound represented by the above formula (3) in which a = 11, b = 33, c = 11, d = 18, m = 3, R 1 = ethyl group. The silylation rate of the silicon-containing polymer was 17.7%. The number average molecular weight of the silicon-containing polymer was 5,900. Except for this, particles of the boron nitride material of Example 3 were obtained in the same manner as in Example 1.

[0116] Example 4 A styrene-butadiene copolymer represented by the above formula (4) (manufactured by RICON Corporation, product number: RICON100, b+c=44) and an organosilicon compound represented by the above formula (5) (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1040, m=3, R 1 = ethyl group) was hydrosilylated in the presence of a platinum compound-containing catalyst. This resulted in the production of the silicon-containing polymer of Example 4, which is represented by the above formula (3). The silicon-containing polymer of Example 4 is a compound represented by the above formula (3) in which a = 11, b = 12, c = 31, d = 19, m = 3, R 1 = ethyl group. The silylation rate of the silicon-containing polymer was 50.0%. Except for this, the same method as in Example 1 was used to obtain particles of the boron nitride material of Example 4.

[0117] Example 5 A styrene-butadiene copolymer represented by the above formula (4) (manufactured by RICON Corporation, product number: RICON100, b+c=44) and an organosilicon compound represented by the above formula (5) (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1040, m=3, R 1 = ethyl group) was hydrosilylated in the presence of a platinum compound-containing catalyst. This resulted in the production of the silicon-containing polymer of Example 5, which is represented by the above formula (3). The silicon-containing polymer of Example 5 is a compound represented by the above formula (3) in which a = 11, b = 5, c = 44, d = 13, m = 3, R 1 = ethyl group. The silylation rate of the silicon-containing polymer was 71.0%. Except for this, the same method as in Example 1 was used to obtain particles of the boron nitride material of Example 5.

[0118] Example 6 A styrene-butadiene copolymer represented by the above formula (4) (manufactured by RICON Corporation, product number: RICON100, b+c=44) and an organosilicon compound represented by the above formula (5) (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1040, m=3, R 1 = ethyl group) was hydrosilylated in the presence of a platinum compound-containing catalyst. This resulted in the production of the silicon-containing polymer of Example 6, which is represented by the above formula (3). The silicon-containing polymer of Example 6 is a compound represented by the above formula (3) in which a = 11, b = 38, c = 1, d = 23, m = 3, R 1= ethyl group. The silylation rate of the silicon-containing polymer was 1.6%. Except for this, particles of the boron nitride material of Example 6 were obtained in the same manner as in Example 1.

[0119] Example 7 A styrene-butadiene copolymer represented by the above formula (4) (manufactured by RICON Corporation, product number: RICON100, b+c=44) and an organosilicon compound represented by the above formula (5) (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1040, m=3, R 1 = ethyl group) was hydrosilylated in the presence of a platinum compound-containing catalyst. This resulted in the production of the silicon-containing polymer of Example 7, which is represented by the above formula (3). The silicon-containing polymer of Example 7 is a compound represented by the above formula (3) in which a = 11, b = 27, c = 2, d = 33, m = 3, R 1 = ethyl group. The silylation rate of the silicon-containing polymer was 3.2%. Except for this, the same method as in Example 1 was used to obtain particles of the boron nitride material of Example 7.

[0120] Comparative Example 1: Instead of the silicon-containing polymer, 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number: KBM-503) was used. Methacrylsilane is a common silane coupling agent composed of a silicon-containing low molecular weight compound. The molecular weight of 3-methacryloxypropyltrimethoxysilane was 248.4. 1 g of 3-methacryloxypropyltrimethoxysilane was dissolved in toluene to obtain a toluene solution having a concentration of 0.1 mg / mL. 2 g of polydopamine-coated boron nitride was added to the obtained solution. The solution temperature was set to 100°C, and the mixture was stirred with a magnetic stirrer for 3 hours. A solid was then obtained by filtration. The obtained solid was washed with a toluene solution and then dried. This yielded particles of Comparative Example 1.

[0121] Comparative Example 2: Instead of the silicon-containing polymer, trimethoxyvinylsilane (Tokyo Chemical Industry Co., Ltd., product number: V0042) was used. Vinylsilane is a common silane coupling agent made of a silicon-containing low molecular weight compound. The molecular weight of trimethoxyvinylsilane was 148.2. 1 g of trimethoxyvinylsilane was dissolved in toluene to obtain a toluene solution having a concentration of 0.1 mg / mL. Other than this, the particles of Comparative Example 2 were obtained by the same method as Comparative Example 1.

[0122] Comparative Example 3 As particles in Comparative Example 3, polydopamine-coated boron nitride obtained by the same method as in Example 1 was used.

[0123] The particles obtained in the above-mentioned Examples and Comparative Examples were evaluated for heat resistance and dielectric loss tangent according to the methods described below.

[0124] [Heat resistance] For each particle group obtained in the examples and comparative examples, the weight change was measured when the temperature was raised from 20°C to 500°C at a heating rate of 5°C / min under a nitrogen atmosphere. The weight at the start of heating (20°C) was used as the starting point, and the temperature at which the weight loss rate was 1% (1% weight loss temperature) was measured. A thermogravimetric analyzer (TG / DTA7200, manufactured by Hitachi High-Tech Science Corporation) was used as the measuring device.

[0125] The heat resistance of each particle group was evaluated based on the measured 1% weight loss temperature. If the 1% weight loss temperature was 220°C or higher, it was determined that the heat resistance was good, and if it was 250°C or higher, it was determined that the heat resistance was particularly good.

[0126] [Dielectric Loss Tangent] The dielectric loss tangent at a frequency of 1 GHz was measured for each of the particle groups obtained in the Examples and Comparative Examples using a cavity resonator (MS46122B, manufactured by AET Co., Ltd.) as the measuring device.

[0127] The dielectric loss tangents of the particles of the Examples and other Comparative Examples were normalized with the dielectric loss tangent of Comparative Example 3 set to 1. If it was less than 1, the dielectric loss tangent was judged to be good, and if it was 0.5 or less, the dielectric loss tangent was judged to be particularly good.

[0128] The 1% weight loss temperatures and dielectric loss tangents of the examples and comparative examples are shown in Table 1 together with the silylation rates.

[0129]

[0130] <<Discussion>> As can be seen from Table 1, in Examples 1 to 7, the 1% weight loss temperature was 220°C or higher, and heat resistance was improved. Furthermore, in Examples 1 to 7, the dielectric loss tangent was less than 1, and the dielectric loss tangent was also reduced.

[0131] In Examples 1 to 5, where the silylation ratio was 5.0% or more, the 1% weight loss temperature was 250°C or higher, and the heat resistance was particularly good. In Examples 3 to 5, where the silylation ratio was 15.0% or more, higher heat resistance and lower dielectric dissipation factor were realized. In particular, in Examples 4 and 5, where the silylation ratio was 30.0% or more, the 1% weight loss temperature was 300°C or higher, showing even higher heat resistance, and the dielectric dissipation factor was 0.5 or less, and the dielectric dissipation factor was particularly good.

[0132] In order to express the present disclosure, the present disclosure has been appropriately and sufficiently described through the embodiments in the above, but it should be recognized that those skilled in the art can easily change and / or improve the above-described embodiments. Therefore, unless the changes or improvements made by those skilled in the art are at a level that deviates from the scope of the claims described in the claims, the changes or improvements are interpreted as being included in the scope of the claims.

[0133] The boron nitride material of the present disclosure can be used as a filler with excellent heat resistance, and therefore can be used in applications such as wiring boards for electronic devices used in high-capacity communications.

[0134] REFERENCE SIGNS LIST 1 Boron nitride 2 Polydopamine 3 Silicon-containing polymer 10 Boron nitride material 20 Resin composition 22 Filler 24 Curable resin 30 Resin-coated film 32 Resin layer 34 Support film 40 Resin-coated metal foil 42 Resin layer 44 Metal foil 50 Metal-clad laminate 52 Insulating layer 54 Metal foil 60 Wiring board 62 Insulating layer 64 Wiring

Claims

1. Boron nitride; polydopamine attached to the boron nitride; a silicon-containing polymer attached to the polydopamine. Boron nitride material.

2. the silicon-containing polymer comprises a first side chain comprising a silicon atom and an oxygen atom and is attached to the polydopamine via the silicon atom and the oxygen atom; 2. The boron nitride material of claim 1.

3. The silicon-containing polymer comprises a second side chain comprising at least one selected from the group consisting of a carbon-carbon double bond and a carbon-carbon triple bond; 2. The boron nitride material of claim 1.

4. The second side chain is composed only of a chain structure. The boron nitride material of claim 3.

5. The silicon-containing polymer comprises a main chain comprising at least one selected from the group consisting of a styrene unit, a butadiene unit, an ethylene unit, and a siloxane unit; 2. The boron nitride material of claim 1.

6. The silicon-containing polymer comprises a backbone comprising the butadiene unit.

6. The boron nitride material of claim 5.

7. The silicon-containing polymer comprises a copolymer comprising the styrene units and the butadiene units.

7. The boron nitride material of claim 6.

8. The silicon-containing polymer is —SiR 3-n (OX) n containing a functional group represented by n is an integer from 1 to 3; X represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a moiety bonded to the polydopamine, or a moiety bonded to a silicon atom other than the silicon atom of the functional group; at least one of X is a moiety that binds to the polydopamine; R represents a hydrocarbon group having 1 to 10 carbon atoms; 2. The boron nitride material of claim 1.

9. The silicon-containing polymer is represented by the following formula (1) containing a plurality of repeating units:

9. The boron nitride material of claim 8. 【Chemistry 1】 In the formula (1), a and d are numbers equal to or greater than 0, and b and c are numbers greater than 0. In the formula (1), the order of the multiple repeating units is arbitrary.

10. In the formula (1), 0.050≦c / (b+c+d) is satisfied.

10. The boron nitride material of claim 9.

11. Comprising the boron nitride material of claim 1. Filler.

12. Comprising the filler of claim 11. Resin composition.

13. The resin composition according to claim 12 or a semi-cured product of the resin composition, Prepreg.

14. A resin layer comprising the resin composition according to claim 12 or a semi-cured product of the resin composition; A support film, Resin-coated film.

15. A resin layer comprising the resin composition according to claim 12 or a semi-cured product of the resin composition; A metal foil, Metal foil with resin.

16. An insulating layer comprising a cured product of the resin composition according to claim 12 or a cured product of the prepreg according to claim 13; A metal foil, Metal-clad laminate.

17. An insulating layer comprising a cured product of the resin composition according to claim 12 or a cured product of the prepreg according to claim 13; With wiring, wiring board.

18. Providing a substrate comprising boron nitride and polydopamine attached to a surface of the boron nitride; contacting the substrate with a silicon-containing polymer; Including, A method for producing boron nitride materials.

19. The number average molecular weight of the silicon-containing polymer is 1200 or more.

20. A method for producing the boron nitride material of claim 18.

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