Electronic interference suppression materials

Abstract

An electronic interference suppression material comprising a base material including at least one selected from organic and inorganic materials, and a powdered carbon material, wherein the powdered carbon material is at least one selected from a first shell-shaped body having one or more holes, and a second shell-shaped body having a plurality of holes and a shape in which the hollow particles are connected, and the shell portions of the first shell-shaped body and the second shell-shaped body are made of graphene having an average number of layers of 4 or less.

Description

Technology Field

[0001] The present disclosure relates to an electronic interference suppression material. Background Technology

[0002] Recently, various measures are being implemented with the aim of mitigating electronic interference, such as device malfunctions caused by electronic noise, information leakage, and the degradation of information and communication speeds due to interference. As means to mitigate electronic interference, methods of blocking electromagnetic waves through reflection or absorbing electromagnetic waves have been proposed.

[0003] For example, Patent Document 1 proposes an electromagnetic shielding material formed by dispersing a soft magnetic metal powder, such as a metal selected from Fe, Ni, Co, and V or an alloy composed of two or more of these metals, in a matrix of rubber or plastic and molding it into a sheet; Patent Document 2 proposes a sheet-shaped electromagnetic absorber in which an electromagnetic absorbing layer formed by a electromagnetic absorbing material, in which silicon carbide powder is dispersed in a matrix resin, is laminated on the surface of a metal body; and Patent Document 3 proposes an electromagnetic absorbing sheet in a frequency band of 5 to 7 GHz having a dielectric layer formed of a matrix including a carbon material, a divided conductive film layer laminated on one side of the dielectric layer, and an electromagnetic reflection layer laminated on the other side of the dielectric layer. Prior art literature

[0004] Japanese Patent Publication No. 2001-68889 Japanese Patent Publication No. 2005-57093 Japanese Patent Publication No. 2012-209515 The problem to be solved

[0005] Conventionally, many proposals aimed at reducing electromagnetic interference have been made, such as the electromagnetic shielding materials, electromagnetic wave absorbers, and electromagnetic wave absorbing sheets described in the aforementioned patent documents 1 to 3. However, due to the recent increase in performance and diversification of communication devices, there are cases where the reduction of electromagnetic interference is insufficient, and further improvements are required.

[0006] In addition, there was also the challenge that methods of blocking electromagnetic waves through reflection using metals, etc., could not avoid self-poisoning.

[0007] The present disclosure is made in consideration of these circumstances and aims to provide an electromagnetic interference suppression material that has good electromagnetic wave absorption performance and electromagnetic interference suppression performance, and better performance in reducing electromagnetic interference. means of solving the problem

[0008] As a result of careful consideration to solve the above problem, the inventors found that an electromagnetic interference suppression material comprising a base material including at least one selected from organic and inorganic materials and a predetermined powder carbon material has good electromagnetic wave absorption performance and electromagnetic interference suppression performance, and better performance in reducing electromagnetic interference.

[0009] The present disclosure is completed based on these findings.

[0010] That is, the present disclosure relates to the following.

[0011] [1] An electronic interference suppression material comprising a base material including at least one selected from organic and inorganic materials, and a powdered carbon material,

[0012] The above powder carbon material is at least one type selected from a first shell-shaped body having a hollow particle with one hole, and a second shell-shaped body having a plurality of holes and a shape in which hollow particles are connected.

[0013] An electronic interference suppression material comprising a shell portion of the first shell-shaped body and the second shell-shaped body, the shell portion being made of graphene having an average number of layers of 4 or less.

[0014] [2] The electronic interference suppression material described in [1] above, having a specific surface area of ​​1300 m² / g or more of the powder carbon material.

[0015] [3] An electronic interference suppression material described in [1] or [2], wherein the volume of the holes in the first shell-shaped body and the holes in the second shell-shaped body is 1.3 cc / g or more.

[0016] [4] Volume resistance is 10 3 An electronic interference suppression material described in any one of [1] to [3] above, having an Ω·cm or greater.

[0017] [5] An electronic interference suppression material described in any one of [1] to [4], wherein the average particle size of the powder carbon material is 200 μm or less.

[0018] [6] An electronic interference suppression material described in any one of [1] to [5], wherein the organic material is an epoxy resin.

[0019] [7] An electronic interference suppression material described in any one of [1] to [5], wherein the inorganic material is ceramic.

[0020] [8] An electronic interference suppression material described in any one of [1] to [7], wherein the organic material or the inorganic material is a foam.

[0021] [9] An electronic interference suppression material described in any one of [1] to [8], wherein the content of the above powdered carbon material is 0.01 to 95 mass%.

[0022]

[10] An electronic interference suppression material described in any one of [1] to [9], wherein the powder carbon material is present on the surface of a base material comprising at least one type selected from the organic or inorganic material.

[0023]

[11] A semiconductor device sealing material comprising an electronic interference suppression material described in any one of [1] to [7] above. Effects of the invention

[0024] According to the present disclosure, it is possible to provide an electromagnetic interference suppression material that has good electromagnetic wave absorption performance and electromagnetic interference suppression performance, and better performance in reducing electromagnetic interference. Specific details for implementing the invention

[0025] Hereinafter, the present disclosure will be described in detail with reference to an embodiment.

[0026] In this specification, the notation "XX to YY" means "XX or greater and YY or less." Furthermore, in this specification, the lower and upper limits described stepwise for a numerical range (e.g., a range of content, etc.) may each be combined independently. Additionally, regarding the numerical range described in this specification, the upper or lower limit of the numerical range may be substituted with the values ​​shown in the examples.

[0027] In this specification, "electronic interference suppression material" refers to a material capable of attenuating nearby electromagnetic fields and electromagnetic waves by utilizing loss characteristics (magnetic loss, dielectric loss, electrical resistance, etc.).

[0028] In this specification, "graphene" refers to "10 layers or less sp 2 It means "sheet-like material of bonded carbon atoms."

[0029] In this specification, the “average number of layers” of graphene is a value obtained by the following formula. Specifically, it is obtained by the method described in the examples below.

[0030] Average number of graphene layers = 2627 (m² / g) / specific surface area (m² / g)

[0031] The above specific surface area refers to the BET specific surface area, which is a value obtained by measuring via the BET multi-point method based on nitrogen adsorption.

[0032] In this specification, a hollow particle refers to a particle having a shell portion, wherein the interior of the particle surrounded by the shell portion is a cavity.

[0033] [Electronic interference suppression materials]

[0034] The electronic interference suppression material of the present disclosure comprises a base material comprising at least one selected from organic and inorganic materials, and a powdered carbon material. The powdered carbon material is at least one selected from a first shell-shaped body having a hollow particle having one hole, and a second shell-shaped body having a shape in which hollow particles are connected and having a plurality of holes, and the shell portions of the first shell-shaped body and the second shell-shaped body are made of graphene having an average number of layers of 4 or less.

[0035] The above powdered carbon material is at least one selected from the first shell-shaped body and the second shell-shaped body, and the shell portions of the first shell-shaped body and the second shell-shaped body are made of graphene having an average number of layers of 4 or less, and the obtained electron interference suppression material has good electromagnetic wave absorption performance and electron interference suppression performance, and has better performance in reducing electron interference. The reason for this is not certain, but it is thought as follows.

[0036] The powdered carbon material of the present disclosure is a hollow particle, and the shell portion of the hollow particle is composed of graphene having an average number of layers of 4 or less. In other words, the powdered carbon material of the present disclosure is a shell-type graphene laminate composed of graphene sheets having an average number of layers of 4 or less that are three-dimensionally continuous. Therefore, the powdered carbon material has a large specific surface area as a carbon material and high electromagnetic wave absorption performance per unit volume. In addition, the powdered carbon material can improve volume resistivity compared to when it contains the same amount of other carbon materials. It is believed that by having a large specific surface area and an effect of improving volume resistivity, the electromagnetic wave absorption performance and electromagnetic interference suppression performance are improved by containing the powdered carbon material of the present disclosure.

[0037] The shell portion of the first shell-shaped body and the second shell-shaped body may be made of graphene with an average number of layers of less than 4, or may be made of graphene with an average number of layers of 3 or less, or may be 2.5 or less, or 2.0 or less, or 1.9 or less, in order to increase the specific surface area of ​​the powder carbon material and further improve electromagnetic wave absorption performance and electromagnetic interference suppression performance.

[0038] In one aspect of the present disclosure, the electromagnetic interference suppression material has a volume resistivity of 10 in order to further improve electromagnetic wave absorption performance and electromagnetic interference suppression performance. 3 It may be Ω·cm or greater, and 10 6 It may be Ω·cm or greater, and 10 7 It may be greater than Ω·cm. There is no specific upper limit, but 10 16 It may be Ω·cm or less.

[0039] The powder carbon material of the present disclosure may be present in an electronic interference suppression material, or may be present on the surface of a base material comprising at least one selected from the organic or inorganic material.

[0040] Powdered Carbon Materials

[0041] The powder carbon material of the present disclosure is at least one selected from a first shell-shaped body having a hollow particle having one hole, and a second shell-shaped body having a plurality of holes and having a shape in which hollow particles are connected. In addition, the shell portions of the first shell-shaped body and the second shell-shaped body are made of graphene having an average number of layers of 4 or less.

[0042] The first shell-shaped body of the present disclosure is a hollow particle having one hole.

[0043] The average hole diameter of the hole having the first shell-shaped body may be 0.5 to 100 nm, 0.7 to 50 nm, or 1.0 to 20 nm.

[0044] In addition, the average hole diameter of the holes in the first shell-shaped body and the second shell-shaped body is a value obtained from the following formula, assuming a cylindrical hole.

[0045] Average hole diameter = 4 × hole volume / specific surface area (㎡ / g)

[0046] In addition, the volume of the pore is a value per mass of material obtained from the adsorption amount at a relative pressure (P / P0) of 0.96 by performing nitrogen adsorption isotherm measurements, and the specific surface area refers to the BET specific surface area, which is a value obtained by measuring by the BET multi-point method due to nitrogen adsorption.

[0047] The second shell-shaped body of the present disclosure has a shape in which hollow particles are connected and has a plurality of holes.

[0048] The holes in the second shell-shaped body may be multiple, and there are no particular limitations.

[0049] The average hole diameter of one hole in the second shell-shaped body may be 0.5 to 100 nm, 0.7 to 50 nm, or 1.0 to 20 nm.

[0050] The average particle size of the first shell-shaped body described above may be considered to be the same as the average hole diameter of the hole of the first shell-shaped body described above, given that the shell thickness is very thin.

[0051] The average particle size of the second shell-shaped body may be 1.0 nm or more, 2.0 nm or more, or 5.0 nm or more from the perspective of ease of manufacturing, and may be 1000 nm or less, 500 nm or less, or 200 nm or less from the perspective of further improving electromagnetic wave absorption performance and electromagnetic interference suppression performance.

[0052] In addition, the average particle size of the second shell-shaped body can be estimated by using a laser diffraction particle size distribution system.

[0053] The average particle size of the above-mentioned powdered carbon material may be 200 μm or less in order to further improve electromagnetic wave absorption performance and electromagnetic interference suppression performance. In addition, in this specification, "average particle size of the powdered carbon material" refers to the average particle size of primary particles when the powdered carbon material is not aggregated and is a primary particle, and refers to the average particle size of secondary particles when the powdered carbon material is aggregated to form secondary particles.

[0054] In addition, the average particle size of the above-mentioned powder carbon material is a value calculated from the volume and specific surface area of ​​the holes, estimated by a laser diffraction particle size distribution system, or calculated as the average value of the particle sizes observed in 20 to 100 fields of view using a scanning electron microscope (SEM) or a transmission electron microscope (TEM). In addition, "particle size" is defined as the maximum distance between any two points passing through the center of the particle and on the outline of the particle.

[0055] In the case where the above powdered carbon material is not aggregated and is a primary particle, the average particle size (primary particle) of the above powdered carbon material may be 1 nm or more, 5 nm or more, or 10 nm or more from the perspective of ease of manufacturing, and may be 1000 nm or less, 500 nm or less, or 100 nm or less from the perspective of further improving electromagnetic wave absorption performance and electromagnetic interference suppression performance.

[0056] When the above powdered carbon material aggregates to form secondary particles, the average particle size (secondary particles) of the above powdered carbon material may be 0.1㎛ or more, 1.0㎛ or more, or 5.0㎛ or more from the perspective of ease of manufacturing, and may be 200㎛ or less, 100㎛ or less, 50㎛ or less, or 20㎛ or less from the perspective of further improving electromagnetic wave absorption performance and electromagnetic interference suppression performance.

[0057] The specific surface area of ​​the above powdered carbon material may be 657 m² / g or more, 1000 m² / g or more, 1300 m² / g or more, 1500 m² / g or more, or 1700 m² / g or more from the perspective of further improving electromagnetic wave absorption performance and electromagnetic interference suppression performance. In addition, from the perspective of ease of manufacturing, it may be 2627 m² / g or less, 2500 m² / g or less, 2400 m² / g or less, or 2300 m² / g or less.

[0058] In addition, the above specific surface area refers to the BET specific surface area, and is a value measured by the BET multi-point method based on nitrogen adsorption.

[0059] The volume of the hole in the first shell-shaped body and the hole in the second shell-shaped body may be 1.0 cc / g or more, 1.3 cc / g or more, 1.6 cc / g or more, 10.0 cc / g or less, 9.0 cc / g or less, or 8.0 cc / g or less, in order to further improve electromagnetic wave absorption performance and electromagnetic interference suppression performance. If the volume of the hole is 1.0 cc / g or more, a higher specific surface area can be obtained.

[0060] In addition, the volume of the above hole is a value obtained from the adsorption amount at which the relative pressure (P / P0) is 0.96 by performing nitrogen adsorption isotherm measurements.

[0061] The powdered carbon material of the present disclosure has carbon as a main component. Here, "carbon as a main component" means that the carbon content in the powdered carbon material is 50 mass% or more. The carbon content in the powdered carbon material may be 80 mass% or more, 95 mass% or more, or 98 mass% or more.

[0062] In the present disclosure, the content (mass%) of the powdered carbon material in the electromagnetic interference suppression material is not particularly limited as it varies significantly depending on the application and the base material. It may be 0.01 to 95 mass% with respect to the total amount of the electromagnetic interference suppression material in order to further improve electromagnetic wave absorption performance and electromagnetic interference suppression performance.

[0063] In the case where the electronic interference suppression material of the present disclosure is a molded body, the content (mass%) of the powdered carbon material in the electronic interference suppression material may be 0.01 to 95 mass%, 0.01 to 20 mass%, or 0.05 to 10 mass% with respect to the total amount of the electronic interference suppression material in order to further improve electromagnetic wave absorption performance and electronic interference suppression performance. A molded body refers to a molded body manufactured by placing it into a mold such as a casting or die.

[0064] When the electronic interference suppression material of the present disclosure is a foam, the content (mass%) of the powdered carbon material in the electronic interference suppression material may be 0.05 to 20 mass%, 0.1 to 10 mass%, or 0.2 to 5 mass% with respect to the total amount of the electronic interference suppression material in order to further improve electromagnetic wave absorption performance and electronic interference suppression performance.

[0065] [Graphene]

[0066] The graphene of the present disclosure is a sheet-like material having a hexagonal lattice structure in which carbon atoms are bonded. The graphene may be in a single-layer state having a layer thickness of one carbon atom, or in a multilayer state of two or more layers. In addition to carbon atoms, the graphene may include oxygen atoms, hydrogen atoms, nitrogen atoms, boron atoms, etc.

[0067] The content of graphene in the first shell-shaped body and the second shell-shaped body is not particularly limited, but in order to further improve electromagnetic wave absorption performance and electronic interference suppression performance, it may be 90% mass% or more, 95% mass% or more, or 98% mass% or more.

[0068] <Material>

[0069] The base material of the present disclosure comprises at least one selected from organic and inorganic materials. The base material may comprise only organic materials, only inorganic materials, or both organic and inorganic materials.

[0070] [Organic matter]

[0071] The organic material included in the base material is not particularly limited, but examples include thermosetting resins, thermoplastic resins, etc.

[0072] Examples of thermosetting resins include epoxy resin, phenolic resin, and imide resin.

[0073] Examples of thermoplastic resins include polyamide resin and polycarbonate.

[0074] As one embodiment of the present disclosure, the organic material may be a molded article for the purpose of reducing moisture permeability, and as another embodiment, it may be a foamed article for the purpose of improving electron absorption capacity and reducing weight by increasing the surface area. Examples of foamed articles include expanded polyurethane, expanded polystyrene, expanded polyvinyl chloride, expanded polyethylene, expanded polypropylene, expanded polyethylene terephthalate, etc. It may also be expanded polyurethane for the purpose of improving electron absorption capacity and reducing weight by increasing the surface area.

[0075] The above organic material may be a thermosetting resin from the perspective of the reliability of a molded article using an electron interference suppression material, or an epoxy resin or an imide resin from the perspective of the electrical insulation and heat resistance of a molded article using an electron interference suppression material. It may be a polyurethane from the perspective of ease of manufacturing, durability, weather resistance, etc., and for outdoor use, it may be a polycarbonate-based polyurethane with good hydrolytic resistance.

[0076] The above organic material may be used as a single type, or a combination of two or more types may be used.

[0077] In the present disclosure, the epoxy resin used as an organic material has two or more epoxy groups in one molecule and is generally used in electronic components, and its molecular structure, molecular weight, etc. are not particularly limited.

[0078] Examples of the above epoxy resins include phenol novolak-type epoxy resins, cresol novolak-type epoxy resins, aliphatic epoxy resins such as dicyclopentadiene derivatives, and aromatic epoxy resins such as biphenyl-type, biphenyl-aryl-type, naphthyl-type, and bisphenol-type resins. These epoxy resins may be used as a single type or as a mixture of two or more types. There are no particular restrictions on the physical form, and it may be either liquid or solid at room temperature (25°C). For example, the above epoxy resin may be a solid cresol novolak-type epoxy resin. The above solid cresol novolak-type epoxy resin is available as a commercial product, and examples include N670 (manufactured by DIC Corporation). In addition, for example, the above epoxy resin may be a liquid epoxy resin, and specifically examples include bisphenol A-type epoxy resins and bisphenol F-type epoxy resins. Liquid bisphenol A type epoxy resins are available as commercial products, for example, Epomic (registered trademark) R140 (manufactured by Mitsui Kagaku Co., Ltd.).

[0079] In addition, in the present disclosure, liquid epoxy resin refers to an epoxy resin that is in a liquid state at 25°C.

[0080] The epoxy equivalent of the above epoxy resin may be 140 or more in terms of the thermomechanical properties of a molded body using an electromagnetic interference suppression material. In addition, it may be 200 or more in terms of electromagnetic wave absorption performance. As for the upper limit of the above epoxy equivalent, it may be 400 or less in terms of thermomechanical properties, or 380 or less.

[0081] The above epoxy resin is (R 1 Polyoxyalkylene structure represented by O)m and (R2 It may be an epoxy resin having a polyoxyalkylene structure represented by O)n.

[0082] Here, R 1 and R 2 Each independently represents an alkylene group having 1 or more carbon atoms. m+n may be 1 or more and 50 or less, or 1 or more and 20 or less. Also, m may be 0 or more and 49 or less, or 0 or more and 19 or less. n may be 1 or more and 50 or less, or 1 or more and 20 or less.

[0083] R 1 and R 2 Examples of alkylene groups represented by [the alkylene group] include alkylene groups having 1 to 6 carbon atoms, and specifically, methylene groups, ethylene groups, trimethylene groups, propylene groups, tetramethylene groups, hexamethylene groups, etc. From the perspective of electromagnetic wave absorption performance, the above alkylene group may be a methylene group or an ethylene group.

[0084] m R 1 In the O period, multiple R 1 The groups may be identical alkylene groups or alkylene groups with different carbon numbers. In addition, n R 2 In the O period, multiple R 2 They may be identical alkylene groups, or alkylene groups with different carbon numbers.

[0085] Examples of epoxy resins having the above polyoxyalkylene structure include liquid epoxy resins having a bisphenol A backbone and polyethylene glycol diglycidyl ether. Examples of commercially available liquid epoxy resins having a bisphenol A backbone include Rica Resin BEO-60E (manufactured by Shin Nippon Rica Co., Ltd.) represented by the following general formula (1), and examples of commercially available polyethylene glycol diglycidyl ether include Epolite 400E (manufactured by Kyoei Co., Ltd.) which has a compound represented by the following general formula (2) as a main component.

[0086]

[0087]

[0088] In the present disclosure, examples of imide resins used as organic materials include bisallyl azimide. Bisallyl azimide is available as a commercial product, and examples include BANI-M (manufactured by Maruzen Sekiyu Kagaku Co., Ltd.) and BANI-X (manufactured by Maruzen Sekiyu Kagaku Co., Ltd.).

[0089] In the present disclosure, the polyurethane used as the organic material is not particularly limited in its molecular structure, provided that it is one commonly used in electronic components. Furthermore, foamed polyurethane is generally obtained by using polyols, polyisocyanates, and a foaming agent as essential components, and by adding a catalyst, a foaming aid, etc. to these components and reacting and foaming them.

[0090] Examples of polyol components include polyester polyols, polyether polyols, polycarbonate polyols, polymer polyols, etc. These polyols may be used individually or in combination of two or more types.

[0091] Examples of the above polyester polyols include aliphatic dicarboxylic acids having 4 to 20 carbon atoms, such as adipic acid, suberic acid, sebacic acid, and bracylic acid, aromatic dicarboxylic acids, such as terephthalic acid and isophthalic acid, as an acid component, and aliphatic diols having 1 to 6 carbon atoms, such as ethylene glycol, and ether glycols, such as diethylene glycol and dipropylene glycol, as a polyol component (alcohol component).

[0092] As the above isocyanate component, various known polyfunctional aliphatic, alicyclic, and aromatic isocyanates may be used. Examples include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate, triphenyl diisocyanate, xylene diisocyanate (XDI), polymethylene polyphenylene polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate (IPDI), orthotoluidine diisocyanate, naphthylene diisocyanate, xylylene diisocyanate, lysine diisocyanate, etc., and one of these may be used alone or two or more may be used in combination.

[0093] Examples of foaming agents include water, Freon, and pentane.

[0094] In one embodiment of the present disclosure, when the organic material is a molded body, the content (mass%) of the organic material in the electromagnetic interference suppression material may be 1 to 40 mass%, 3 to 30 mass%, 4 to 25 mass%, or 5 to 20 mass% with respect to the total amount of the electromagnetic interference suppression material in order to further improve electromagnetic wave absorption performance and electromagnetic interference suppression performance.

[0095] In another aspect of the present disclosure, when the organic material is a foam, the content (mass%) of the organic material in the electromagnetic interference suppression material may be 80 to 99.95 mass%, 90 to 99.9 mass%, or 95 to 99.8 mass% with respect to the total amount of the electromagnetic interference suppression material in order to further improve electromagnetic wave absorption performance and electromagnetic interference suppression performance.

[0096] When the above organic material includes a thermosetting resin, the electronic interference suppression material of the present disclosure may further contain a curing agent and a curing accelerator, etc.

[0097] Examples of the above-mentioned curing agents include aliphatic amines, aromatic amines, dicyandiamides, dihydrazide compounds, acid anhydrides, phenolic resins, etc. One of these may be used, or two or more may be used in combination.

[0098] Examples of the above-mentioned curing accelerators include organic peroxides such as dicumyl peroxide and dibutyl peroxide; imidazole compounds such as 2-methylimidazole and 2-ethylimidazole; organic phosphorus compounds such as trimethylphosphine, triethylphosphine, tributylphosphine, and triphenylphosphine; diazabicycloalkene compounds such as 1,8-diazabicyclo[5,4,0]undecene-7 (DBU) and 1,5-diazabicyclo(4,3,0)nonene-5; and tetraphenylboron compounds such as 2-ethyl-4-methylimidazole tetraphenylbolate. These may be used individually or in combination of two or more types.

[0099] In one embodiment of the present disclosure, when the electronic interference suppression material of the present disclosure contains a curing agent, the content thereof may be 0 mass% or more and 150.0 mass% or less with respect to 100 mass% of the thermosetting resin, 0 mass% or more and 120 mass% or less, or 0 mass% or more and 100 mass% or less.

[0100] In another embodiment of the present disclosure, when the electronic interference suppression material of the present disclosure contains a curing agent, the content thereof may be 1.0 mass% or more and 20.0 mass% or less with respect to the total amount of the electronic interference suppression material, 2.0 mass% or more and 18.0 mass% or less, and 3.0 mass% or more and 15.0 mass% or less.

[0101] In addition, when the electronic interference suppression material of the present disclosure contains a curing accelerator, the content thereof may be 0.01 mass% or more and 10.0 mass% or less with respect to the total amount of the electronic interference suppression material, 0.05 mass% or more and 5.0 mass% or less, and 0.1 mass% or more and 3.0 mass% or less.

[0102] The electronic interference suppression material of the present disclosure may further include a dispersion aid. The dispersion aid may be any material capable of stably and highly dispersing fine particles in a matrix resin, and generally, a surfactant having different reactive functional groups in one molecule and a coupling agent are used. Examples of the dispersion aid include anionic surfactants such as carboxylates, cationic surfactants such as quaternary ammonium salts; coupling agents having amine-based functional groups and sulfide-based functional groups, cellulose nanofibers, etc.

[0103] The above cellulose nanofibers are bipolar ultrafine solids that improve the dispersibility of the filler through their surfactant action. The cellulose nanofibers may also be highly dispersed in a liquid such as water or a thermosetting resin oligomer.

[0104] The average fiber length of the above cellulose nanofiber may be 1㎛ or more and 100㎛ or less from the perspective of workability and fluidity, or 5㎛ or more and 50㎛ or less.

[0105] The average fiber diameter of the above cellulose nanofibers, including aggregates, may be 1 nm or more and 1000 nm or less, or 4 nm or more and 500 nm or less. By having the above average fiber diameter within the above range, the dispersibility of the powder carbon material can be increased and the electronic interference suppression performance can be further improved.

[0106] In addition, the average fiber length and average fiber diameter of the cellulose nanofibers can be measured using a scanning electron microscope (SEM) by the same operation as the average fiber length and average fiber diameter of the carbon nanotubes described above.

[0107] Examples of commercially available coupling agents having the above-mentioned amine-based and sulfide-based functional groups include SUMILINK (registered trademark) 100 (manufactured by Sumitomo Chemicals, Inc.). Examples of commercially available cellulose nanofibers include ELLEX-S (manufactured by Daio Seiji Co., Ltd.).

[0108] When the dispersion agent is included in the electronic interference suppression material of the present disclosure, the content thereof may be 0.1 to 30 mass%, 0.2 to 10 mass%, or 0.3 to 5 mass% with respect to the total amount of the electronic interference suppression material in terms of maintaining dispersibility and thermomechanical properties.

[0109] In addition to the above components, the electronic interference suppression material of the present disclosure may, as necessary, incorporate additives such as release agents, including synthetic waxes, natural waxes, higher fatty acids, and esters of higher fatty acids, which are generally incorporated into electronic interference suppression materials of this type, within a scope that does not deviate from the gist of the present disclosure; coloring agents such as cobalt blue; modifiers such as silicone oil and silicone rubber; hydrotalcites; ion capture agents; charge control agents; and flame retardants such as phosphazene. Each of these additives may be used as a single type, or two or more types may be mixed and used.

[0110] In the electronic interference suppression material of the present disclosure, the content of each of these additives may be 0.05 to 30.0 mass% as the total amount of each additive with respect to the total amount of the electronic interference suppression material, or 0.2 to 20.0 mass%.

[0111] [Inorganic]

[0112] The inorganic material included in the base material is not particularly limited as long as it is an inorganic material used in electronic components, but may include the inorganic material (A) and inorganic material (B) described below.

[0113] You may use one type of these, or you may use a combination of two or more types.

[0114] (Inorganic(A))

[0115] The inorganic material (A) is at least one selected from inorganic fillers such as silica, alumina, magnesium oxide, titanium oxide, barium titaniumate, silicon nitride, aluminum nitride, silicon carbide and tungsten carbide, amorphous magnetic metal alloys, Ni-Fe alloys, pure iron, mild steel, silicon steel (Fe-Si alloys), Fe-Al alloys, Fe-Si-Al alloys, Co-Fe alloys, soft magnetic materials such as carbonyl iron, magnetite and ferrite, and is an inorganic material other than the inorganic material (B) described below.

[0116] The above inorganic material (A) may be used together with organic material. It may be at least one selected from silica and alumina in order to reduce the coefficient of expansion or increase the thermal conductivity of the electromagnetic interference suppression material, or it may be silica. In addition, it may be at least one selected from ferrite and amorphous magnetic metal alloys in order to further improve electromagnetic wave absorption performance and electromagnetic interference suppression performance.

[0117] The shape of the above-mentioned inorganic material (A) is not particularly limited, but examples include powder, spherical, flake, fibrous forms, etc. The shape of the above-mentioned inorganic material may be powder or spherical.

[0118] The average particle size of the above inorganic material (A) is not particularly limited, but may be 0.1㎛ or more and 100㎛ or less, 0.2㎛ or more and 75㎛ or less, or 0.2㎛ or more and 50㎛ or less.

[0119] In addition, in this specification, the average particle size refers to the volume average particle diameter, and the average particle size of the inorganic material (A) can be calculated as the average value of the major axis of the particles measured using a laser diffraction particle size distribution measuring device.

[0120] When the inorganic material (A) is included in the electronic interference suppression material of the present disclosure, the content thereof may be 30 to 92 mass%, 40 to 90 mass%, or 50 to 88 mass% with respect to the total amount of the electronic interference suppression material in order to further improve electromagnetic wave absorption performance and electronic interference suppression performance.

[0121] When the electron interference suppression material of the present disclosure is used as a sealing material for semiconductors, metal foreign matter is removed during the manufacturing process of the semiconductor sealing material. When metal foreign matter is removed using a magnet, the magnetic material is considered a foreign matter and is removed, resulting in a poor yield. In this regard, when the magnetic material is included in the electron interference suppression material of the present disclosure, its content may be 1 mass% or less, 0.5 mass% or less, or 0 mass% with respect to the total amount of the electron interference suppression material. Furthermore, since the magnetic material has a high specific gravity, the content of the magnetic material may be less than or equal to the above values ​​from the perspective of reducing the weight of the resulting molded body.

[0122] (Inorganic(B))

[0123] Inorganic material (B) is ceramics.

[0124] The ceramics mentioned above are not particularly limited, but specifically, examples include sintered bodies having metal oxides, nitrides, carbides, etc. as main components.

[0125] Specifically, oxides of the above metals include alumina, zirconia, magnesium oxide, etc.

[0126] Specifically, examples of the nitrides of the above metals include aluminum nitride, boron nitride, silicon nitride, etc.

[0127] Specifically, silicon carbide, boron carbide, etc., can be cited as carbides of the above metal.

[0128] The ceramic may be at least one sintered body selected from alumina and aluminum nitride. The ceramic may be a molded body, or a foamed porous alumina, etc.

[0129] [Method for manufacturing powdered carbon material]

[0130] Hereinafter, an embodiment of the method for manufacturing a powder carbon material of the present disclosure is described, but the present disclosure is not limited to the following form.

[0131] The powdered carbon material according to the present disclosure can be manufactured by a method comprising, for example, a first step of using particles such as alumina or magnesium oxide as a mold, coating a carbon layer on the mold, and preparing the carbon-coated particles, a second step of melting and removing the mold, and a third step of heat treatment. By using such a method, a powdered carbon material with a high specific surface area composed of an average number of graphene layers of 4 or less can be easily obtained.

[0132] Process 1

[0133] (template)

[0134] As a mold for synthesizing the powdered carbon material of the present embodiment, it is necessary to be capable of introducing organic matter into the surface and pores, stably maintaining the original structure during CVD treatment, and being easily separated from the generated powdered carbon material. For this reason, it may have good heat resistance and be removable using an acid or an alkali.

[0135] The resulting powdered carbon-based material has pores that reflect the shape of the mold itself. In other words, the carbon material is synthesized in a state that transfers the shape of the mold. For this reason, the mold may be a material with a uniform structure and composition and matching particle size, and by using such a material, a powdered carbon material having pores of controlled size can be prepared. In addition, to achieve a high specific surface area, the material may be one that can control the average number of graphene layers obtained to 4 or less.

[0136] Examples of such molds include particles such as alumina, silica, magnesium oxide, tungsten carbide, aluminum nitride, cerium oxide, titanium oxide, and calcium carbonate. These particles may also be nanoparticles. From the perspective of the material properties that the mold must possess and the properties of the powdered carbon material obtained, at least one particle selected from alumina and magnesium oxide may be used, alumina particles may be used, and alumina nanoparticles may be used.

[0137] The type of alumina is not particularly limited, but θ-alumina and γ-alumina may be used.

[0138] The average particle size of the particles used in the mold is not particularly limited, but it may be 4 to 100 nm or 5 to 20 nm. If the average particle size is 4 nm or more, it is easy to handle and has good carbon coating properties. In addition, since the gas permeability of the carbon source is good when coating the carbon source, uniform carbon coating becomes easy. On the other hand, if the average particle size is 100 nm or less, a powdered carbon material with a high specific surface area (BET specific surface area) can be obtained. In addition, the decrease in yield of the powdered carbon material caused by a relative increase in the amount of mold melted in the subsequent process can be reduced.

[0139] The above particles may be used in combination with granular spacers. By using spacers, a suitable gap can be secured between the particles, and the pressure loss caused by the particles being too tightly packed can be reduced. As for the spacers, the average particle size may be, for example, 100 to 5000 μm. The material of the spacers is not particularly limited as long as it can be sieved after carbon coating, and it may not decompose at 900 to 1000°C. Alternatively, it may be one that can be dissolved and removed simultaneously with the mold. Examples include quartz sand, silica, alumina, silica-alumina, titania, etc. For example, when using quartz sand, it may be used after being washed with acid beforehand and calcined at 600 to 1000°C for 1 to 5 hours to control the particle size to the above.

[0140] The mixing ratio of the particles and spacers is not particularly limited, but for example, the (particles:spacers) may be in a mass ratio of 0.1:10 to 10:10 or 1:10 to 10:10. Within the above range, the powdered carbon material can be obtained in a high yield.

[0141] (Covering of carbon layer)

[0142] The method of coating a carbon layer on the surface of the template particle is not particularly limited and both wet and dry methods can be applied, but Chemical Vapor Deposition (CVD) may be used in order to keep the average number of graphene layers 4 or less.

[0143] The CVD method, used to introduce organic compounds and deposit a carbon layer on a mold, is an industrial method for fabricating thin films (e.g., thin films made of carbon) composed of specific elements or elemental compositions on a substrate such as a mold. Typically, it is a technology that utilizes the process in which energy is imparted to a gas containing raw materials by heat or light, or plasma-generated by high frequency, causing the raw materials to become radicalized and highly reactive through chemical reactions or thermal decomposition, and then adsorbed and deposited on the substrate.

[0144] The organic compound used in the CVD method may be a gas at room temperature or capable of vaporization. Methods of vaporization include heating above the boiling point or reducing the atmosphere to a reduced pressure. The organic compound used may be appropriately selected from carbon source materials. In particular, it may be a compound that undergoes thermal decomposition upon heating, or a compound capable of depositing a carbon layer on the surface of the particles used as a mold.

[0145] In addition, the organic compound used may be an organic compound containing hydrogen. This organic compound may be an organic compound containing unsaturated or saturated hydrocarbons, or a mixture thereof.

[0146] The organic compound used may be an unsaturated straight-chain or branched-chain hydrocarbon having double and / or triple bonds, a saturated straight-chain or branched-chain hydrocarbon, etc., or may be a saturated cyclic hydrocarbon, an aromatic hydrocarbon such as benzene, toluene, etc. As an organic compound, alcohols such as methanol and ethanol, or nitrogen-containing compounds such as acetonitrile and acrylonitrile may be used. Examples of organic compounds include acetylene, methylacetylene, ethylene, propylene, isoprene, cyclopropane, methane, ethane, propane, benzene, toluene, vinyl compounds, ethylene oxide, methanol, ethanol, acetonitrile, acrylonitrile, etc. One type of organic compound may be used alone, or two or more types may be used in combination. Among these, the organic compound used may be one that can enter the voids between particles, such as acetylene, ethylene, propylene, methane, ethane, etc. Methane, propylene, and benzene may be used in order to precipitate highly crystalline carbon. In addition, methane may be used in order to obtain highly crystalline carbon with a high thermal decomposition temperature.

[0147] The organic compound used for CVD at higher temperatures and for CVD at lower temperatures may be the same or different. For example, acetylene, ethylene, etc. may be used for CVD at lower temperatures, and propylene, isoprene, benzene, etc. may be used for CVD at higher temperatures.

[0148] When introducing an organic compound onto the above particles, the particles may be subjected to reduced pressure beforehand, or the system itself may be subjected to reduced pressure. Any method involving carbon deposition by CVD may be used. For example, a carbon layer may be coated onto the alumina particles by depositing (or adsorbing) carbon generated by the chemical reaction or thermal decomposition of an organic compound onto the alumina particles.

[0149] The pressure during CVD treatment is not particularly limited and, for example, may be 1 kPa to 200 kPa or 50 to 150 kPa. The heating temperature during CVD treatment should be a condition that allows for the formation of a carbon layer of several layers or less on the particles, and an appropriately suitable temperature can be selected depending on the organic compound used. The heating temperature may be 400 to 1500°C, 450 to 1100°C, or 550 to 950°C. For example, when propylene is used as the organic compound, the temperature may be 700 to 900°C, and when methane is used, the temperature may be 900 to 1100°C. However, the temperature may be about 50 to 200°C lower than the decomposition temperature of the organic compound. If heated above the decomposition temperature of the organic compound, gaseous carbon precipitation becomes significant, but by doing as described above, the variation in the amount of carbon deposited between the surface and the interior of the particles can be reduced, for example, and the carbon can be deposited uniformly.

[0150] In addition, the heating temperature can be appropriately selected based on the CVD processing time and / or the pressure within the reaction system. Additionally, the product may be analyzed, and the temperature required to achieve the desired number of layers may be set based on the results.

[0151] The heating rate during CVD treatment is not particularly limited, but may be 1 to 50°C / min or 5 to 20°C / min. The treatment time during CVD treatment (CVD treatment time at a predetermined heating temperature) should be the time required to obtain graphene with an average number of layers of 4 or less, and an appropriately suitable time may be selected depending on the organic compound used or the temperature. For example, the treatment time during CVD treatment may be 5 minutes to 8 hours, 0.5 to 6 hours, or 1 to 5 hours. In addition, the time required for sufficient carbon deposition may be set based on the results of analyzing the product.

[0152] CVD treatment may be performed under reduced pressure, under vacuum, under pressurized conditions, or under an inert gas atmosphere. When performed under an inert gas atmosphere, examples of inert gases include nitrogen, helium, neon, argon, etc., and nitrogen may be used.

[0153] In the CVD method, carbon can be easily deposited or adsorbed onto particles in the gas phase by heating while passing a gaseous organic compound in contact with the particles along with a carrier gas. The type of carrier gas, flow rate, flow rate, and heating temperature are appropriately adjusted according to the type of organic compound used. Examples of carrier gases include the aforementioned inert gases, nitrogen, or a mixture with oxygen or hydrogen gas.

[0154] With respect to keeping the average number of graphene layers 4 or less, the flow rate of the carrier gas may be, for example, 0.05 to 1.0 m / min or 0.32 to 0.64 m / min. In addition, the amount of organic compound introduced may be 1 to 30 volume% or 5 to 20 volume% with respect to the total amount of the carrier gas and the organic compound.

[0155] As a method for coating a carbon layer on the above particles, carbonization may be performed by introducing an organic compound using a wet method such as an impregnation method. Additionally, carbonization may be performed by impregnating the organic compound with the organic compound before performing CVD. As for the organic compound to be impregnated, for example, a thermal polymerizable monomer such as furfuryl alcohol, which has a high carbonization yield, may be used. For the method of impregnating the organic compound, known means may be employed, such as contacting the particles by bringing the organic compound into contact with the particles as is if it is a liquid, by mixing it with a solvent, or by dissolving it in a solvent if it is a solid.

[0156] After the first process, the carbon-coated particles may be heat-treated and the carbon layer carbonized to precipitate highly crystalline carbon on the surface of the particles. By doing so, the powdered carbon material obtained becomes more highly crystalline and has a high specific surface area.

[0157] Since carbonization of the carbon layer can also be carried out by CVD treatment, the above heat treatment may be performed during CVD treatment or by other methods.

[0158] The method of heat treatment is not particularly limited, and heat treatment may be performed using a high-frequency induction furnace, etc.

[0159] Process 2

[0160] The second process of this embodiment, the process of melting and removing the mold, is a process of melting and removing the mold from carbon-coated particles and obtaining a shell-shaped body.

[0161] For the dissolution and removal of the mold, an alkaline solution such as NaOH, KOH, LiOH, RbOH, or CsOH may be used. For example, an alkaline solution with a concentration of 1 to 5 M may be used. The alkaline solution may have a stoichiometric ratio of 30 times or more, or 50 times or more, relative to the particles. If the stoichiometric ratio is 30 times or more, the retention of mold particles can be suppressed. When dissolving and removing, for example, carbon-coated particles may be placed in the alkaline solution and heat-treated at a heat treatment temperature of 200 to 300°C. At this time, in order to ensure uniform contact of the alkaline solution with the sample, the carbon-coated particle sample may be ground in advance. The heating rate during heat treatment is not particularly limited, and is, for example, 200 to 300°C / hour. The heat treatment time (holding time at the specified heat treatment temperature) is not particularly limited, and is, for example, 1 to 5 hours. This dissolution and removal process may be performed multiple times. In addition, the product can be analyzed, and based on the results, conditions required for sufficient mold removal can be set.

[0162] After melting and removing the mold, the shell-shaped body may be recovered by filtration, for example, or dried by vacuum heat drying. The conditions for vacuum heat drying are not particularly limited, and for example, the vacuum heat drying temperature may be 100 to 200°C. In addition, the vacuum heat drying time may be 1 to 10 hours, for example.

[0163] Process 3

[0164] The third process is a heat treatment process. By undergoing the third process after the second process, the crystallinity of the coated carbon is increased and stabilized. As a result, the powdered carbon material is provided with conductivity, corrosion resistance, and a high specific surface area at a higher level.

[0165] There are no specific restrictions on the heat treatment temperature, but it may be 1100 to 1850°C or 1550 to 1830°C. If the heat treatment temperature is 1550°C or higher, the effects of the present invention can be obtained more significantly. In addition, if the temperature is 1850°C or lower, it is possible to prevent the remaining mold and carbon from reacting.

[0166] The heat treatment time (holding time at a predetermined heat treatment temperature) may be 0.1 to 10 hours, 0.2 to 5 hours, or 0.5 to 2 hours. In addition, the heat treatment process may be performed under reduced pressure.

[0167] By the method having the above-mentioned first to third processes, graphene with an average number of layers of 4 or less can be obtained.

[0168] [Method for manufacturing electronic interference suppression material]

[0169] In one embodiment of the present disclosure, when a molded body (not a foam) is used as the organic material, the electron interference suppression material may be obtained by sufficiently and uniformly mixing a base material containing at least one type of organic material, a powdered carbon material, and other components that are blended as needed using a mixer, etc., and then performing a mixing treatment using a disperser, a kneader, a three-roll mill, a twin-axis heated roll, a twin-axis heated extrusion mixing device, etc. The mixing treatment may be performed by heating. The temperature at that time may be 70°C or higher and 150°C or lower, or 75°C or higher and 120°C or lower.

[0170] The electronic interference suppression material of the present disclosure may be used, for example, by cooling and solidifying it after the above-mentioned mixing process, and then crushing it to a suitable size using a cutting mill, ball mill, cyclone mill, hammer mill, vibration mill, cutter mill, grinder mill, speed mill, etc.

[0171] In addition, the mixture obtained after the above mixing treatment may be formed into a sheet by pressing it with a molding machine under conditions of a temperature of 50°C or higher and 100°C or lower and a pressure of 0.5 MPa or higher and 1.5 MPa or lower.

[0172] The electronic interference suppression material of the present disclosure can be used as a radio wave absorbing material, a noise suppression sheet, a semiconductor sealing material, a sealing sheet, a wire sheathing material, etc.

[0173] As one embodiment of the present disclosure, for example, a resin-sealed electronic component can be obtained by sealing a semiconductor device fixed on a substrate with a semiconductor device sealant comprising the electron interference suppression material of the present disclosure.

[0174] In addition, known molding methods are used to obtain electronic components without being particularly limited. Low-pressure transfer molding is the most common molding method, but molding by injection molding, die molding, compression molding, etc., is also possible.

[0175] For example, in the case of a transfer molding method, a heat treatment may be performed by a transfer molding machine at a temperature of 150°C or higher and 200°C or lower and a time of 20 seconds or higher and 200 seconds or lower, and the molded product may be removed from the molding mold, and a heat treatment to complete curing may be performed at a temperature of 150°C or higher and 200°C or lower and a time of 2 hours or higher and 12 hours or lower.

[0176] In addition, in the case of the compression molding method, first, a substrate with a semiconductor device mounted thereon is supplied to the upper mold of the molding die, and at the same time, the electron interference suppression material of the present disclosure is supplied into the cavity of the lower mold. Subsequently, by clamping both the upper and lower molds with a required clamping pressure, the substrate with the semiconductor device mounted thereon is immersed in the electron interference suppression material heated and melted within the lower mold cavity. After that, the electron interference suppression material heated and melted within the lower mold cavity is pressed against the cavity bottom member, and compression molding is performed by applying a required pressure while reducing the pressure. The molding conditions may be a temperature of 120°C or higher and 200°C or lower, and a pressure of 2 MPa or higher and 20 MPa or lower.

[0177] In another aspect of the present disclosure, when an inorganic material (B) is used as the base material, the electron interference material is obtained by the following method. A suitable organic binder and solvent are added and mixed to the raw material powder of the ceramics to produce a sliding material. A ceramic green sheet is produced by molding this sliding material into a sheet shape using the conventionally known doctor blade method. The material is obtained by firing the ceramic green sheet. Alternatively, the material may be obtained by dispersing a powdered carbon material in a solvent and, if necessary, immersing the obtained ceramics in a mixed dispersion containing other components. In addition, the material may be obtained by firing the powdered carbon material with a component capable of becoming a ceramic green sheet.

[0178] The components that can become ceramics and the conditions for firing the powdered carbon material are not specifically limited and may be adjusted appropriately depending on the components that can become ceramics. It may be performed under an inert gas atmosphere. The firing temperature may be 600°C to 1800°C or 1000°C to 1600°C.

[0179] In another aspect of the present disclosure, an electronic interference suppression material comprising a foam as an organic or inorganic material may be obtained by dispersing a powdered carbon material in a solvent and, if necessary, immersing the foam in a mixed dispersion containing other components. Additionally, it may be obtained by methods such as foaming a component capable of becoming a foam, a powdered carbon material, and other components blended as necessary using a foaming machine, or foaming by molding with a pressure press and then firing in the atmosphere.

[0180] The conditions for foaming these are not specifically limited and may be adjusted appropriately depending on the components that can become the foam.

[0181] Examples

[0182] The present disclosure will be specifically described below by way of examples, but the present disclosure is not limited to these examples in any way.

[0183] [Manufacture of Powdered Carbon Materials]

[0184] <Preparation Example 1>

[0185] (Preparation of carbon-coated alumina nanoparticles)

[0186] Alumina nanoparticles (TM300 manufactured by Daimei Kagaku Kogyo Co., Ltd., crystal phase: γ-alumina, average particle size: 7 nm, specific surface area: 220 m² / g) and quartz sand (manufactured by Sendai Wako Junyaku Co., Ltd.) as a spacer were mixed in a mass ratio of 3:20 (alumina nanoparticles:quartz sand). At this time, the quartz sand used was immersed in 1 M hydrochloric acid for 12 hours, heated in air at 800°C for 2 hours in a muffle furnace, and sieved through a sieve with a mesh size of 180 μm. The mixture of alumina nanoparticles and quartz sand prepared above was placed in a reaction tube (inner diameter 37 mm), and CVD (methane CVD) using methane as a carbon source was performed.

[0187] For methane CVD, alumina nanoparticles were heated from room temperature to 900°C at a heating rate of 10°C / min under conditions where the N2 gas flow rate was controlled to 224 ml / min, and maintained at 900°C for 30 minutes. Subsequently, N2 gas was used as a carrier gas, and 20 volume% of methane relative to the total amount of carrier gas and methane was introduced into the reaction tube, and chemical vapor deposition (CVD) treatment was performed at 900°C for 2 hours. At this time, the methane gas flow rate was controlled to 45 ml / min and the N2 gas flow rate to 179 ml / min. Afterward, the introduction of methane gas was stopped, and the mixture was maintained at 900°C for 30 minutes under conditions where the N2 gas flow rate was controlled to 224 ml / min, followed by cooling to obtain carbon-coated alumina nanoparticles.

[0188] (Removal of melted mold)

[0189] Carbon-coated alumina nanoparticles and 5M NaOH (more than 50 times the stoichiometric ratio) were placed in a Teflon (registered trademark) autoclave, heated at a heating rate of 250°C / hour using a muffle furnace, and maintained at 250°C for 2 hours. Afterward, the mixture was cooled naturally, recovered by filtration, and dried by vacuum heating at 150°C for 6 hours to obtain a shell-shaped body.

[0190] (Heat treatment)

[0191] The shell-shaped body obtained from the above (melting and removal of the mold) was broken, a few fragments were collected and placed in a graphite crucible, and set in an induction furnace. To remove air from the reaction tube, a vacuum was created using an oil pump and left for 30 minutes. Afterward, water was flowed through the water-cooling jacket of the reaction tube, the inside of the induction furnace system was heated, and heat treatment was performed to obtain a powdered carbon material. Furthermore, the above heat treatment was performed under vacuum. Additionally, as for the heat treatment conditions, the temperature was first raised from room temperature to 1000°C over 60 minutes at a rate of 16.7°C / min, then raised to 1800°C over 160 minutes at a rate of 5°C / min, heated at 1800°C for 60 minutes, and then naturally cooled to room temperature to obtain powdered carbon material 1 (second shell-shaped body).

[0192] <Preparation Example 2>

[0193] (Preparation of carbon-coated alumina nanoparticles)

[0194] Alumina nanoparticles (TM300 manufactured by Daimei Kagaku Kogyo Co., Ltd., crystal phase: γ-alumina, average particle size: 7 nm, specific surface area: 220 m² / g) and quartz sand (manufactured by Sendaiwako Junyaku Co., Ltd.) as a spacer were mixed in a mass ratio of 3:20 (alumina nanoparticles:quartz sand). At this time, the quartz sand used was immersed in 1 M hydrochloric acid for 12 hours, heated in air at 800°C for 2 hours in a muffle furnace, and sieved through a sieve with a mesh size of 180 μm. The mixture of alumina nanoparticles and quartz sand prepared above was placed in a reaction tube (inner diameter 37 mm), and CVD (methane CVD) using methane as a carbon source was performed.

[0195] For methane CVD, alumina nanoparticles were heated from room temperature to 900°C at a heating rate of 10°C / min under conditions where the N2 gas flow rate was controlled to 224 ml / min, and maintained at 900°C for 30 minutes. Subsequently, N2 gas was used as a carrier gas, and 20 volume% of methane relative to the total amount of carrier gas and methane was introduced into the reaction tube, and chemical vapor deposition (CVD) treatment was performed at 900°C for 6 hours. At this time, the methane gas flow rate was controlled to 45 ml / min and the N2 gas flow rate to 179 ml / min. Afterward, the introduction of methane gas was stopped, and the mixture was maintained at 900°C for 30 minutes under conditions where the N2 gas flow rate was controlled to 224 ml / min, followed by cooling to obtain carbon-coated alumina nanoparticles.

[0196] (Removal of melted mold)

[0197] The same operation as in Manufacturing Example 1 was performed.

[0198] (Heat treatment)

[0199] Powdered carbon material 2 (second shell-shaped body) was obtained by the same operation as manufacturing method 1.

[0200] <Comparative Preparation Example 1>

[0201] (Preparation of carbon-coated alumina nanoparticles)

[0202] Alumina nanoparticles (TM300 manufactured by Daimei Kagaku Kogyo Co., Ltd., crystal phase: γ-alumina, average particle size: 7 nm, specific surface area: 220 m² / g) and quartz sand (manufactured by Sendai Wako Junyaku Co., Ltd.) as a spacer were mixed in a mass ratio of 3:20 (alumina nanoparticles:quartz sand). At this time, the quartz sand used was immersed in 1 M hydrochloric acid for 12 hours, heated in air at 800°C for 2 hours in a muffle furnace, and sieved through a sieve with a mesh size of 180 μm. The mixture of alumina nanoparticles and quartz sand prepared above was placed in a reaction tube (inner diameter 37 mm), and CVD (methane CVD) using methane as a carbon source was performed.

[0203] For methane CVD, alumina nanoparticles were heated from room temperature to 950°C at a heating rate of 10°C / min under conditions where the N2 gas flow rate was controlled to 224 ml / min, and maintained at 950°C for 30 minutes. Subsequently, N2 gas was used as a carrier gas, and 20 volume% of methane relative to the total amount of carrier gas and methane was introduced into the reaction tube, and chemical vapor deposition (CVD) treatment was performed at 950°C for 20 hours. At this time, the methane gas flow rate was controlled to 45 ml / min and the N2 gas flow rate to 179 ml / min. Afterward, the introduction of methane gas was stopped, and the mixture was maintained at 950°C for 30 minutes under conditions where the N2 gas flow rate was controlled to 224 ml / min, followed by cooling to obtain carbon-coated alumina nanoparticles.

[0204] (Removal of melted mold)

[0205] The same operation as in Manufacturing Example 1 was performed.

[0206] (Heat treatment)

[0207] The same operation as in manufacturing method 1 was performed, and powdered carbon material 3 (second shell-shaped body) was obtained.

[0208] [Measurement and Evaluation of Powdered Carbon Materials]

[0209] Measurement and evaluation of the following items were performed on the obtained powdered carbon material. The results of these measurements and evaluations are summarized in Table 1.

[0210] <Specific Surface Area (BET Specific Surface Area)>

[0211] After vacuum heating and drying the obtained powdered carbon material at 150°C for 6 hours, the specific surface area was determined by the multi-point method from the nitrogen adsorption isotherm measured using the high-precision automatic gas / vapor adsorption amount measuring device “BEL SORP MAX” (manufactured by Nippon Bel Co., Ltd.).

[0212] Average number of layers in graphene

[0213] The average number of graphene layers was calculated from the specific surface area obtained by the above-described method using the following formula.

[0214] Average number of graphene layers = 2627 (m² / g) / specific surface area (m² / g)

[0215] Volume of the hole

[0216] After vacuum heating and drying the obtained powdered carbon material at 150°C for 6 hours, nitrogen adsorption isotherm measurements were performed using the high-precision automatic gas / vapor adsorption amount measuring device “BEL SORP MAX” (manufactured by Nippon Bell Co., Ltd.), and the volume of holes per mass of material was calculated from the adsorption amount at which the relative pressure (P / P0) was 0.96.

[0217]

[0218] [Manufacturing of Electronic Interference Suppression Materials]

[0219] The details of each component listed in Tables 2 and 3 used in the manufacture of the electronic interference suppression material are as follows.

[0220] [Organic matter]

[0221] · Epoxy resin: EPICLON N670; Cresol novolak type epoxy resin; Manufactured by DIC Corporation, Epoxy equivalent: 210

[0222] [Inorganic]

[0223] · Silica: FB105; Manufactured by Denka Co., Ltd., Average particle size: 12㎛

[0224] [Carbon Materials]

[0225] · Carbon Black (CB): TPK1227R; Manufactured by Cabot, Average particle size: 0.1㎛

[0226] · Carbon Nanotubes (CNT): LUCAN; Manufactured by LG: Average fiber length: 30㎛, Average fiber diameter: 0.02㎛

[0227] [Additives]

[0228] · Curing agent: BRG-557; Phenol novolak resin; Manufactured by Aika Kogyo Co., Ltd.

[0229] · Curing accelerator: Curezol C11Z; Imidazole compound; Manufactured by Shikoku Kasei Co., Ltd.

[0230] · Flame Retardant: Rabitol (phosphazene-based flame retardant) FP100; Manufactured by Mitsui Kagaku Fine Co., Ltd.

[0231] In addition, the powdered carbon materials 1 to 3 listed in Tables 2 and 3 used in the manufacture of the electronic interference suppression material are ground products of powdered carbon materials 1 to 3 obtained in Manufacturing Examples 1 and 2 and Comparative Manufacturing Example 1, respectively, and all of them were prepared by grinding and classifying powdered carbon materials 1 to 3 to an average particle size of 10 μm.

[0232] <Examples 1–3 and Comparative Examples 1–5>

[0233] Each component of the type and amount listed in Table 2 was fed into a Henschel mixer and mixed, then fed into a twin-roll kneading device heated to 110°C, and heat kneading was performed until homogeneous. Next, the obtained heat-kneaded material was fed into a cold roll, stretched into a sheet, and then crushed to obtain an electron interference suppression material composition. The obtained electron interference suppression material composition was compression molded into a molded body with a thickness of 0.5 mm, 1.0 mm, or 25 mm (temperature: 175°C, pressure: 10 MPa) to obtain an electron interference suppression material.

[0234] <Example 4>

[0235] Adipic acid, diethylene glycol, and trimethylenepropane were placed in a flask, heated at 120°C and mixed, then triisopropyl titanate was added, and an adipic acid-based polyester polyol was prepared by dehydrating under reduced pressure at 240°C.

[0236] 10 parts by mass of the above adipic acid-based polyester polyol, 70 parts by mass of the terephthalic acid-based polyester polyol "Terol 250" (manufactured by Oxide (OXID) Co., Ltd.), 20 parts by mass of the ethylenediamine-based polyether polyol "AE-300" (manufactured by Mitsui Kagaku Polyurethane Co., Ltd.), 15 parts by mass of the flame retardant "TMCPP" (manufactured by Daihachi Kagaku Kogyo Co., Ltd.), 1 part by mass of the foam stabilizer "L-5340" (manufactured by Nippon Unica Co., Ltd.), 2.5 parts by mass of the catalyst "KL-31" (manufactured by Kao Corporation), 35 parts by mass of the blowing agent "HFC-245fa", and 1.5 parts of water were mixed to obtain a polyol mixture.

[0237] The obtained polyol mixture and the isocyanate "Smidul 44V20" (manufactured by Sumika Bayer Urethane Co., Ltd.) were prepared, mixed, and stirred so that the urethane index was 105. The obtained mixture was placed into a mold and molded to a size of 440mm × 440mm × 25mm to obtain a rigid polyurethane foam (foamed polyurethane). Additionally, a rigid polyurethane foam molded to a size of 440mm × 440mm × 25mm was obtained by the same operation, and it was cut into 440mm × 440mm × 0.5mm or 440mm × 440mm × 1.0mm.

[0238] Next, a mixed dispersion 1 was prepared by mixing 1 part by mass of the powdered carbon material 1 obtained in Preparation Example 1 into 10,000 mL of the urethane-based emulsion "Super Flex" (manufactured by Daiichi High School Seiyaku Co., Ltd.), and the expanded polyurethane obtained in the mixed dispersion 1 was immersed at room temperature for 30 minutes, then heated at 120°C for 120 minutes and dried to obtain an electron interference suppressing material in which the powdered carbon material is localized on the surface of the expanded polyurethane.

[0239] <Examples 5 and Comparative Examples 6–8>

[0240] An electron interference suppression material in which a carbon material is localized on the surface of foamed polyurethane was obtained by the same operation as in Example 4, where powdered carbon material 1 was used, in Example 5, powdered carbon material 2 was used, in Comparative Example 6, powdered carbon material 3 was used, in Comparative Example 7, carbon black (CB) was used, and in Comparative Example 8, carbon nanotubes (CNT) were used.

[0241] <Example 6>

[0242] 50 parts by mass of the polyol mixture prepared in Example 4, 50 parts by mass of the isocyanate "Smidul 44V20" (manufactured by Sumika Bayer Urethane Co., Ltd.), and 1 part by mass of the powder carbon material 1 obtained in Preparation Example 1 were fed into an automatic mixing type injection foaming machine (model: MU-203S, model number: 6-018, manufactured by Polyurethane Engineering Co., Ltd.) and foamed under the same molding conditions as in Example 4 to obtain an electron interference suppressing material, which is a foamed polyurethane containing a powder carbon material of 440mm × 440mm × 0.5mm, 440mm × 440mm × 1.0mm, or 440mm × 440mm × 25mm.

[0243] <Comparative Examples 9–11>

[0244] In Example 6, an electron interference suppression material was obtained by the same operation except that powdered carbon material 1 was used, in Comparative Example 9, powdered carbon material 3 was used, in Comparative Example 10, carbon black (CB) was used, and in Comparative Example 11, carbon nanotubes (CNT) were used.

[0245] <Example 7>

[0246] In Example 4, an electron interference suppression material was obtained in which a powdered carbon material was localized on the surface of a ceramic sintered porous body (foam) by the same operation as in Example 4, except that instead of using foamed polyurethane, a ceramic sintered porous body "FA120" (manufactured by Fuji Chemical Co., Ltd., alumina material, average pore diameter 100 μm, average porosity 45-50%) was used.

[0247] <Comparative Example 12>

[0248] In Example 7, an electron interference suppression material was obtained in which a carbon material is localized on the surface of a ceramic sintered porous body by the same operation as in Example 7, except that carbon nanotubes (CNT) were used instead of powdered carbon material 1.

[0249] [Measurement and Evaluation of Electron Interference Suppression Materials]

[0250] Measurement evaluations of the following items were performed on the obtained electronic interference suppression material. The results of these measurement evaluations are summarized in Tables 2 and 3.

[0251] In addition, in the “region of presence of carbon material” of Table 3, “surface” indicates the case where the carbon material is localized on the surface of the electron interference suppression material, and “entire” indicates the case where the carbon material is present inside and on the surface (entire electron interference suppression material).

[0252] <Content of powdered carbon material (mass%)>

[0253] The content of the powdered carbon material was determined from the mixing ratio when the "region of existence of carbon material" was "entire" (Examples 1-3, Example 6, Comparative Examples 1-5, Comparative Examples 9-11), and from the increase in mass before and after the introduction of the carbon material to the surface when the "surface" was "surface" (Example 4, Example 5, Example 7, Comparative Examples 6-8, Comparative Example 12).

[0254] Volume Resistance

[0255] An electronic interference suppression material formed to a thickness of 1.0 mm was used, and the volume resistivity at 150°C was measured in accordance with JIS K-6911:2006.

[0256] Electromagnetic wave absorption performance (frequency 10 GHz, near-field measurement system)

[0257] An electromagnetic interference suppression material formed to a thickness of 0.5 mm was installed between a high-frequency oscillation device and a receiving antenna, and the electromagnetic wave intensity when an electromagnetic wave of 10 GHz frequency was generated was measured with and without the molded body, and the ratio (electromagnetic wave intensity when electromagnetic waves are absorbed by the electromagnetic interference suppression material / electromagnetic wave intensity when there is no electromagnetic interference suppression material) was defined as the electromagnetic wave absorption performance in dB units.

[0258] In addition, electromagnetic field strength was measured in accordance with “Journal of the Institute of Electronics, Information and Communications Engineering B Vol.J97-B No.3 pp.279-285”.

[0259] Electromagnetic wave absorption performance (frequency 5 GHz, far-field measuring system)

[0260] A copper plate (600mm × 600mm) with a thickness of 1mm was installed on an anti-reflection electromagnetic wave absorber, and an electromagnetic interference suppression material (440mm × 440mm) formed to a thickness of 25mm was installed on a metal plate. Next, an antenna was attached to a network analyzer via a cable, and electromagnetic waves with a frequency of 5 GHz were transmitted from one antenna, reflected by the electromagnetic interference suppression material and the metal plate placed underneath, and received by the other antenna to measure the electromagnetic wave intensity. In addition, without installing the electromagnetic interference suppression material on the metal plate, electromagnetic waves were radiated using the same operation as above to measure the electromagnetic wave intensity. The ratio of these (electromagnetic wave intensity when absorbed by the electromagnetic interference suppression material / electromagnetic wave intensity when there is no electromagnetic interference suppression material) was defined as the electromagnetic wave absorption performance in dB units.

[0261] In addition, electromagnetic wave intensity was measured in accordance with “Kagoshima Prefectural Industrial Technology Center Research Report No. 15 (2001), pp. 53-61”.

[0262]

[0263]

[0264] As shown in Table 2, the electromagnetic interference suppression materials of Examples 1 to 3 have good electromagnetic wave absorption performance. In addition, since they have high volume resistivity, it can be said that they also have good electromagnetic interference suppression performance in the near field.

[0265] In addition, as shown in Table 3, the electronic interference suppression materials of Examples 4 to 7 have good radio wave absorption performance.

Claims

Claim 1 An electronic interference suppression material comprising a base material including organic and inorganic materials and a powdered carbon material, wherein the organic material is a thermosetting resin, the inorganic material is at least one selected from silica and alumina, the powdered carbon material is at least one selected from a first shell-shaped body having a hollow particle having one hole, and a second shell-shaped body having a plurality of holes having a shape in which hollow particles are connected, and the shell portions of the first shell-shaped body and the second shell-shaped body are made of graphene having an average number of layers of 4 or less. Claim 2 An electronic interference suppression material according to claim 1, wherein the specific surface area of ​​the powdered carbon material is 1300 m² / g or more. Claim 3 An electronic interference suppression material according to claim 1 or 2, wherein the volume of the hole having the first shell-shaped body and the hole having the second shell-shaped body is 1.3 cc / g or more. Claim 4 In claim 1 or 2, the volume resistivity is 10 3 Electron interference suppression material with a Ω·cm or greater. Claim 5 An electronic interference suppression material according to claim 1 or 2, wherein the average particle size of the powdered carbon material is 200 μm or less. Claim 6 An electronic interference suppression material according to claim 1 or 2, wherein the organic material is an epoxy resin. Claim 7 delete Claim 8 An electronic interference suppression material according to claim 1 or 2, wherein the organic material or the inorganic material is a foam. Claim 9 An electronic interference suppression material according to claim 1 or 2, wherein the content of the powdered carbon material is 0.01 to 95 mass%. Claim 10 An electronic interference suppression material according to claim 1 or 2, wherein the powder carbon material is present on the surface of a base material comprising the organic and inorganic materials. Claim 11 A semiconductor device sealing material comprising the electronic interference suppression material described in claim 1 or 2.

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