WO2017081867A1 - Method for producing composite material sheet and method for producing heat conductive sheet - Google Patents

Method for producing composite material sheet and method for producing heat conductive sheet Download PDF

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Publication number
WO2017081867A1
WO2017081867A1 PCT/JP2016/004845 JP2016004845W WO2017081867A1 WO 2017081867 A1 WO2017081867 A1 WO 2017081867A1 JP 2016004845 W JP2016004845 W JP 2016004845W WO 2017081867 A1 WO2017081867 A1 WO 2017081867A1
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WIPO (PCT)
Prior art keywords
composite
composite particles
material sheet
pressurization
composite material
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PCT/JP2016/004845
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French (fr)
Japanese (ja)
Inventor
村上　康之
大介 内海
将純 小島
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日本ゼオン株式会社
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Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Priority to JP2017549987A priority Critical patent/JP6915545B2/en
Publication of WO2017081867A1 publication Critical patent/WO2017081867A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K7/00—Constructional details common to different types of electric apparatus
    • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields

Definitions

  • the present invention relates to a method for manufacturing a composite material sheet and a method for manufacturing a heat conductive sheet.
  • the temperature of an electronic component may rise due to an increase in the amount of heat generated by the electronic component due to the high performance of the electronic device, resulting in a functional failure in the electronic device.
  • a method of promoting heat dissipation by attaching a heat sink such as a metal heat sink, heat sink, heat sink or the like to a heat generator such as an electronic component is adopted.
  • a heat radiator in order to transmit heat
  • seat excellent in heat conductivity is used as the said heat conductive sheet.
  • electromagnetic noise generated by mutual interference between electronic devices or static electricity may cause a functional failure in the electronic device.
  • a highly conductive composite material sheet may be used as a member that is directly attached to an electronic device or an electronic component, or a member that contacts the electronic device or the electronic component (such as a packing material). it can.
  • the composite material sheet having high conductivity it is possible to prevent noise propagation generated between electronic devices and prevent charging.
  • the composite material sheet is required to exhibit high thermal conductivity and / or high conductivity, preferably with orientation according to the application and use location.
  • Patent Document 1 a conductive curable resin composition obtained by kneading an elastomer component, a radical reactive resin, and a heat conductive material is press-molded with a roll, thereby being excellent in heat conductivity and conductivity.
  • a technique for obtaining a sheet made of a composite material is disclosed.
  • the thermally conductive material coke is pulverized in advance and classified as necessary, and then particles having a particle diameter of 5 ⁇ m or less are removed, and then the coke is graphitized. Is used.
  • the high electroconductivity (low resistance) in a sheet surface and high are used by using together the elastomer component with the boron containing graphite fine powder which grind
  • a sheet having high heat dissipation (high thermal conductivity) and high thickness accuracy is realized even if the carbon material is highly filled.
  • the composite material sheet has high flexibility to make good contact with a non-contacting body without any gap when attached, and thinning of the sheet. There is also a need to have a high strength that can be made possible.
  • the conventional sheets described in Patent Document 1 and the like have not been sufficient in strength and flexibility.
  • the present invention provides a method for manufacturing a composite material sheet and a method for manufacturing a heat conductive sheet, in which high thermal conductivity is ensured and high strength and good flexibility (low hardness) are arranged side by side. Objective.
  • the present inventors have intensively studied to achieve the above object.
  • the inventors of the present invention focused on classifying the composite particles including the heat conductive material and the resin, not the heat conductive material itself, and removing the composite particle group including at least coarse composite particles. Then, by applying pressure to the composite particles contained in the remaining composite particle group to form a sheet, high thermal conductivity, high strength, and low Asker C hardness (hereinafter simply referred to as “hardness”) may be used. ), The present invention has been completed.
  • the present inventors have found that a heat conductive sheet having excellent heat conductivity can be produced using the composite material sheet, and have completed the present invention.
  • “good hardness”, “excellent hardness”, “improvement of hardness” and the like mean that the Asker C hardness is a low value.
  • the present invention aims to advantageously solve the above-mentioned problems, and the method for producing a composite material sheet of the present invention comprises a step of preparing a composite particle for pressurization to obtain a composite particle for pressurization, A method of producing a composite material sheet comprising a pressurizing step of obtaining a composite material sheet by pressurizing the composite particles for pressure, wherein the preparatory step of the composite particles for pressurization includes a particulate carbon material and a resin. And the prepared composite particles are classified into at least two composite particle groups including a composite particle group A having a maximum volume average particle diameter and a composite particle group B having a minimum volume average particle diameter.
  • a composite material sheet having excellent conductivity, strength, and hardness can be provided.
  • the “volume average particle diameter” represents a particle diameter (D50) at which the cumulative volume calculated from the small diameter side is 50% in the particle diameter distribution (volume basis) measured by the laser diffraction method.
  • the “volume average particle size” can be measured using a laser diffraction / scattering particle size distribution measuring apparatus.
  • the volume average particle diameter of the composite particle group including the composite particles used in the step (C) is preferably 500 ⁇ m or less. This is because if a composite particle for pressurization is prepared using composite particles contained in a composite particle group having a volume average particle diameter of 500 ⁇ m or less, a composite material sheet with further improved thermal conductivity, strength, and hardness can be obtained. .
  • the pressurizing composite particles have a content of composite particles having a particle diameter of 500 ⁇ m or more of less than 40% by volume. This is because if the ratio of the composite particles having a particle diameter of 500 ⁇ m or more in the composite particles for pressurization is less than 40% by volume, a composite material sheet with further improved thermal conductivity, strength, and hardness can be obtained.
  • the “composite particle content” in the composite particles for pressurization is calculated from the volume-based particle size distribution obtained using the laser diffraction / scattering particle size distribution measuring device described above. Can do.
  • the composite particles contain 50 parts by mass or more and 150 parts by mass or less of the resin with respect to 100 parts by mass of the particulate carbon material. This is because a composite material sheet having good thermal conductivity, strength, and hardness can be easily obtained by controlling the resin content in the composite particles within the above range.
  • the step (A) includes a kneading step in which the particulate carbon material and the resin are kneaded to obtain a kneaded product, and the kneaded product is pulverized to form the composite particles. It is preferable to include a pulverizing step. This is because the composite particles used in the method for producing a composite material sheet of the present invention can be easily prepared through the kneading step and the pulverization step.
  • the manufacturing method of the heat conductive sheet of this invention is thickness of the said composite material sheet obtained by one of the manufacturing methods mentioned above. Laminating the laminated body by laminating a plurality of sheets in the direction or by folding or winding the composite material sheet obtained by any of the manufacturing methods described above to obtain a laminated body And a slicing step of obtaining a heat conductive sheet by slicing at an angle of 45 ° or less with respect to the direction.
  • seat the heat conductive sheet which has high thermal conductivity of the thickness direction, and has high intensity
  • the present invention it is possible to provide a method for producing a composite material sheet in which high thermal conductivity, high strength, and good hardness are arranged side by side. Moreover, according to this invention, the manufacturing method of the heat conductive sheet which made parallel high heat conductivity, high intensity
  • the method for producing a composite material sheet of the present invention can be used when producing a composite material sheet containing a resin and a particulate carbon material.
  • the composite material sheet manufactured using the manufacturing method of the composite material sheet of this invention is not specifically limited, It can use for various uses as a sheet-like member excellent in heat conductivity and electroconductivity.
  • the composite material sheet produced by the method for producing a composite material sheet of the present invention can be used when producing a heat conductive sheet according to the method for producing a heat conductive sheet of the present invention.
  • the heat conductive sheet manufactured using the manufacturing method of the heat conductive sheet of this invention can be used by inserting
  • the composite material sheet and the heat conductive sheet manufactured according to the manufacturing method of the present invention are excellent in heat conductivity, strength, hardness, and conductivity. Therefore, the composite material sheet and the heat conductive sheet are suitable as, for example, a heat radiating material, a heat radiating component, a cooling component, a temperature adjusting component, and an electromagnetic shielding component used in various devices and apparatuses.
  • various devices and devices are not particularly limited, and are electronic devices such as servers, server personal computers, and desktop personal computers; portable electronic devices such as notebook computers, electronic dictionaries, PDAs, mobile phones, and portable music players.
  • Liquid crystal display including backlight
  • plasma display LED
  • organic EL, inorganic EL, liquid crystal projector display device
  • display device such as clock
  • ink jet printer ink head
  • electrophotographic device developing device, fixing device, heat roller, Image forming apparatuses such as heat belts
  • semiconductor-related components such as semiconductor elements, semiconductor packages, semiconductor encapsulating cases, semiconductor die bonding, CPUs, memories, power transistors, power transistor cases
  • Camera video camera, digital camera, digital video camera, microscope, CCD, etc. image recording equipment
  • Examples thereof include battery devices such as
  • the manufacturing method of the composite material sheet of the present invention includes a step of preparing pressurizing composite particles using predetermined composite particles obtained through the classification operation (preparing step of pressurizing composite particles), and the pressurizing composite. And a step of pressurizing the particles (pressurizing step). And in the manufacturing method of the composite material sheet of the present invention, since the composite material sheet is molded by applying pressure to the composite particles for pressurization prepared using the predetermined composite particles, high thermal conductivity, high strength, and good A composite material sheet with parallel hardness is obtained.
  • the step of preparing composite particles for pressurization included in the method for producing a composite material sheet of the present invention includes a step (A) of preparing composite particles containing a particulate carbon material and a resin, and at least two of the obtained composite particles.
  • the pressurizing composite particles prepared in the pressurizing composite particle preparation step are used for forming a composite material sheet by pressurization.
  • Step (A) composite particles containing a particulate carbon material and a resin are prepared as a material (composite material) when the composite material sheet is manufactured according to the manufacturing method of the present invention.
  • the composite particles prepared in the step (A) contain a particulate carbon material and a resin. Further, the composite particles prepared in the step (A) can contain a known additive that can be generally blended with the fibrous carbon material and the composite material used for molding the composite material sheet, if necessary. .
  • the particulate carbon material of the composite particles is not particularly limited.
  • graphite such as artificial graphite, scale-like graphite, exfoliated graphite, natural graphite, acid-treated graphite, expandable graphite, and expanded graphite. Carbon black; and the like can be used. These may be used individually by 1 type and may use 2 or more types together. Among them, it is preferable to use expanded graphite as the particulate carbon material. This is because if expanded graphite is used, the thermal conductivity of the composite material sheet produced using the composite particles can be further improved.
  • Expanded graphite Here, the expanded graphite that can be suitably used as the particulate carbon material is, for example, finely expanded after heat-treating expandable graphite obtained by chemically treating graphite such as scaly graphite with sulfuric acid or the like. Can be obtained.
  • Examples of expanded graphite include EC1500, EC1000, EC500, EC300, EC100, and EC50 (all are product names) manufactured by Ito Graphite Industries.
  • scaly expanded graphite is preferable.
  • the particulate carbon material is more favorably oriented in the produced composite material sheet, and the contact between the particulate carbon materials is facilitated. This is because it is easy to form a heat transfer path.
  • the particle diameter of the particulate carbon material contained in the composite particles is not particularly limited, but is preferably 150 ⁇ m or more, preferably 500 ⁇ m or less, and preferably 300 ⁇ m or less in volume conversion mode diameter. It is more preferable.
  • the particle diameter of the particulate carbon material is not less than the above lower limit, the particulate carbon materials are in good contact with each other, and the composite material sheet is likely to exhibit high thermal conductivity.
  • the particle diameter of a particulate carbon material is below the said upper limit, a contact area with resin combined together will become large and it will be easy to make a composite material sheet exhibit favorable intensity
  • the aspect ratio (major axis / minor axis) of the particulate carbon material contained in the composite particles of the present invention is preferably 1 or more and 10 or less, and more preferably 1 or more and 5 or less.
  • the “mode diameter in terms of volume” can be measured using a laser diffraction / scattering particle size distribution measuring apparatus. Specifically, the “volume-converted mode diameter” of the particulate carbon material is obtained as the particle diameter at the maximum value of the particle diameter distribution curve obtained using a suspension in which the particulate carbon material is dispersed in a solvent. be able to.
  • the “aspect ratio” refers to the maximum diameter (major axis) and the particle diameter (in the direction perpendicular to the maximum diameter) using an SEM (scanning electron microscope) for any 50 particulate carbon materials ( (Minor axis) is measured and the average value of the ratio of the major axis to the minor axis (major axis / minor axis) is calculated.
  • the measurement of the “particle diameter” and the “aspect ratio” of the particulate carbon material contained in the composite particle is, for example, dissolving the resin using a good solvent for the resin contained in the composite particle, etc.
  • the particulate carbon material can be taken out from the composite particles using any of the above methods.
  • content of particulate carbon material is 0.6 times or more with respect to resin, and, as for composite particles, it is preferable that it is 2.0 times or less.
  • content of the particulate carbon material relative to the resin is 0.6 times or more, the thermal conductivity of the composite material sheet manufactured using the composite particles can be sufficiently increased. Further, if the content of the particulate carbon material relative to the resin is 2.0 times or less, the sheet can be formed while giving high strength to the composite material sheet, and the composite material sheet produced using the composite particles It is possible to suppress an increase in hardness (that is, a decrease in flexibility).
  • the composite particles can further contain a fibrous carbon material in addition to the above-mentioned particulate carbon material.
  • the fibrous carbon material is not particularly limited, and any fibrous carbon material having thermal conductivity can be used.
  • examples of the fibrous carbon material include cylindrical shapes such as vapor-grown carbon fiber, carbon fiber obtained by carbonizing organic fiber, and carbon nanotube (hereinafter sometimes referred to as “CNT”).
  • Carbon nanostructures, non-cylindrical carbon nanostructures such as carbon materials in which a carbon six-membered ring network is formed in a flat cylindrical shape, and their cuts can be used. These may be used individually by 1 type and may use 2 or more types together.
  • a fibrous carbon material containing CNT is used as the fibrous carbon material used in combination with the particulate carbon material from the viewpoint of further improving the thermal conductivity of the composite material sheet by forming a better heat transfer path.
  • the CNT is not particularly limited, and single-walled carbon nanotubes and / or multi-walled carbon nanotubes can be used. From the viewpoint of further improving the thermal conductivity of the composite material sheet, More preferably, it mainly contains single-walled carbon nanotubes, and more preferably only single-walled carbon nanotubes.
  • “mainly containing” single-walled carbon nanotubes means that the content of single-walled carbon nanotubes is 90% by mass or more.
  • the fibrous carbon material containing CNT is not particularly limited, and is a chemical vapor deposition method including an arc discharge method, a laser ablation method, or a super-growth method (see International Publication No. 2006/011655) ( It can be produced using a known CNT synthesis method such as a CVD method.
  • the carbon nanotube obtained by the super growth method may be referred to as “SGCNT”.
  • the average diameter of the fibrous carbon material is preferably 0.5 nm or more, and preferably 15 nm or less. If the average diameter of the fibrous carbon material is 0.5 nm or more, aggregation of the fibrous carbon material can be suppressed and the thermal conductivity of the composite material sheet can be further improved. Moreover, if the average diameter of a fibrous carbon material is 15 nm or less, the thermal conductivity which was excellent in the fibrous carbon material can be exhibited, and the thermal conductivity of a composite material sheet can further be improved.
  • the fibrous carbon material preferably has an average length of 1 ⁇ m or more at the time of synthesis. If the average length of the fibrous carbon material at the time of synthesis is 1 ⁇ m or more, the heat transfer path can be satisfactorily formed in the composite material sheet. In addition, the longer the fibrous carbon material during synthesis, the easier it is to cause damage such as breakage and cutting in the process of preparing composite particles, so the average length of the fibrous carbon material during synthesis The thickness is preferably 5000 ⁇ m or less.
  • the fibrous carbon material usually has an aspect ratio of more than 10.
  • the fibrous carbon material preferably has a BET specific surface area of 200 m 2 / g or more, and preferably 2500 m 2 / g or less. If the BET specific surface area of a fibrous carbon material is 200 m ⁇ 2 > / g or more, the thermal conductivity which was excellent in the fibrous carbon material can be exhibited, and the thermal conductivity of a composite material sheet can fully be improved. Moreover, if the BET specific surface area of a fibrous carbon material is 2500 m ⁇ 2 > / g or less, aggregation of a fibrous carbon material can be suppressed and the thermal conductivity of a composite material sheet can further be improved.
  • the “average diameter”, “aspect ratio”, and “average length” of the fibrous carbon material are measured using a microscope such as TEM (transmission electron microscope) or SEM (scanning electron microscope). It can be obtained by measuring the diameter (outer diameter) and length of 100 randomly selected fibrous carbon materials.
  • the “BET specific surface area” of the fibrous carbon material refers to a nitrogen adsorption specific surface area measured using the BET method.
  • Blending amount of fibrous carbon material And content of the fibrous carbon material in a composite particle can be 0.05 mass part or more per 100 mass parts of resin, and can be 5.0 mass parts or less.
  • the thermal conductivity of the composite material sheet can be sufficiently increased.
  • the content of the fibrous carbon material per 100 parts by mass of the resin is 5.0 parts by mass or less, the hardness of the composite material sheet is increased by mixing the fibrous carbon material (that is, the flexibility is decreased). It is possible to satisfactorily mold the composite material sheet while sufficiently suppressing the above.
  • the resin contained in the composite particle is not particularly limited, and a known resin that can be used for manufacturing a composite material sheet can be used. Specifically, a thermoplastic resin or a thermosetting resin can be used as the resin. In the present invention, rubber and elastomer are included in “resin”. Moreover, you may use together a thermoplastic resin and a thermosetting resin.
  • thermoplastic resin examples include poly (2-ethylhexyl acrylate), a copolymer of acrylic acid and 2-ethylhexyl acrylate, polymethacrylic acid or an ester thereof, and an acrylic resin such as polyacrylic acid or an ester thereof.
  • Silicone resin polyvinylidene fluoride, polytetrafluoroethylene, acrylic modified polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, etc.
  • Fluorine resin Polyethylene; Polypropylene; Ethylene-propylene copolymer; Polymethylpentene; Polyvinyl chloride; Polyvinylidene chloride; Polyvinyl acetate; Ethylene-vinyl acetate copolymer; Polyacetal; Polyethylene terephthalate; Polybutylene terephthalate; Polyethylene naphthalate; Polystyrene; Polyacrylonitrile; Styrene-acrylonitrile copolymer; Acrylonitrile-butadiene-styrene copolymer (ABS resin); Styrene-butadiene block copolymer or its hydrogen Additives; Styrene-isoprene block copolymer or hydrogenated product thereof; Polyphenylene ether; Modified polyphenylene ether; Aliphatic polyamides; Aromatic polyamides; Polyamideimide; Polycarbonate; Polyphenylene sulfide; Polysulfone; Nitrile; poly
  • thermosetting resin examples include natural rubber, butadiene rubber, isoprene rubber, nitrile rubber, hydrogenated nitrile rubber, chloroprene rubber, ethylene propylene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, butyl rubber, and halogenated butyl rubber.
  • thermoplastic resin more preferably a fluororesin, and a binary fluororesin or a ternary fluororesin composed of different monomers. More preferred.
  • a ternary fluororesin a vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer can be used. This is because the fluororesin is excellent in mechanical properties and the like, and if a thermoplastic resin such as a fluororesin is used, the strength and hardness (flexibility) of the composite material sheet can be further improved.
  • the content of the resin contained in the composite particles can be any blending amount.
  • the resin contained in the composite particle is preferably 50 parts by mass or more with respect to 100 parts by mass of the particulate carbon material contained in the composite particle. More than mass part is more preferable, 150 mass parts or less are preferable, 100 mass parts or less are more preferable, and 70 mass parts or less are still more preferable. If the content of the resin per 100 parts by mass of the particulate carbon material is 150 parts by mass or less, the thermal conductivity of the composite material sheet can be sufficiently increased.
  • the sheet can be molded while giving high strength to the composite material sheet, and the hardness of the composite material sheet increases. (That is, flexibility is reduced) can be sufficiently suppressed.
  • -Additive- Additives that can be optionally blended in the composite particles are not particularly limited, and include, for example, red phosphorus flame retardants, phosphate ester flame retardants, and the like; sebacic acid and other plasticizers; calcium oxide, oxidation Hygroscopic agents such as magnesium; Adhesive strength improvers such as silane coupling agents, titanium coupling agents, acid anhydrides; wettability improvers such as nonionic surfactants and fluorosurfactants; inorganic ion exchangers, etc. Ion trapping agents; and the like. Among these, it is preferable to add a phosphate ester flame retardant such as a phosphate ester.
  • a composite particle can be obtained by compounding the above-mentioned particulate carbon material, resin, and optionally a fibrous carbon material and an additive using a known technique.
  • the composite particles can be prepared using, for example, the following method (I) or (II) without any particular limitation.
  • the obtained kneaded product is pulverized (pulverizing stage) to obtain composite particles.
  • a dispersion containing a particulate carbon material, a resin, an arbitrary fibrous carbon material and an additive is dried and granulated to obtain composite particles.
  • the method (I) is desirable from the viewpoint of satisfactorily combining the particulate carbon material and the resin and from the viewpoint of ease of work.
  • Kneading stage In the kneading stage that can be included in the step (A), the particulate carbon material, the resin, the arbitrary fibrous carbon material and the additive are kneaded, the particulate carbon material and the resin are contained, and optionally the fibrous shape A kneaded material further containing a carbon material and an additive is obtained.
  • the kneaded product obtained in the kneading step is usually a lump having a diameter of about 1 mm to 200 mm.
  • the “particulate carbon material”, “resin”, and any “fibrous carbon material” and “additive” contained in the kneaded product obtained in the kneading stage can be contained in the composite particles described above. Since it is the same as the “particulate carbon material”, “resin”, “fibrous carbon material” and “additive”, the type, properties, blending amount, production method, etc. are also the same, so the description is omitted below. To do.
  • the kneading method is not particularly limited, and a kneader; a mixer such as a Hobart mixer, a Banbury mixer, a high-speed mixer; a twin-screw kneader; a roll; it can.
  • mixing time can be made into 5 minutes or more and 60 minutes or less, for example.
  • mixing temperature can be 5 degreeC or more and 150 degrees C or less, for example.
  • the kneading may be performed in the presence of a solvent such as ethyl acetate. When a solvent is used at the time of kneading, it is preferable to move to the pulverization stage described below after removing the solvent. The solvent can be removed by a known drying method.
  • the kneaded product obtained in the above-described kneading stage is appropriately pulverized by an arbitrary technique to obtain composite particles containing the particulate carbon material and the resin.
  • the composite particles obtained in the pulverization stage are not particularly limited and are preferably pulverized to a particle diameter of less than 1000 ⁇ m.
  • the pulverization method is not particularly limited, and can be performed using a known pulverization apparatus utilizing a shearing action or a grinding action or a known stirring pulverization apparatus.
  • known crushing devices using shearing action or grinding action or stirring type include, for example, a cutter mill, a hammer mill, a bead mill, a vibration mill, a meteor type ball mill, a sand mill, a ball mill, a roll mill, a three-roll mill, and a jet mill. And a high-speed rotary crusher. Among these, it is desirable to use a cutter mill or a hammer mill.
  • the pulverization conditions may be adjusted as appropriate according to the desired pulverized particle size, such as the pulverization apparatus and pulverization time.
  • the pulverization time is preferably from 10 seconds to 60 seconds, and when using a hammer mill, the pulverization time is preferably from 5 seconds to 30 seconds.
  • the composite particles prepared in the step (A) include at least two composite particle groups including the composite particle group A having the maximum volume average particle size and the composite particle group B having the minimum volume average particle size. Classify. That is, in the step (B), only the composite particle group A having the maximum volume average particle diameter and the composite particle group B having the minimum volume average particle diameter may be obtained. In the step (B), the composite particle group A having the maximum volume average particle diameter, the composite particle group B having the minimum volume average particle diameter, and the maximum volume average particle diameter and the minimum volume average particle diameter Any other composite particle group having a volume average particle diameter may be obtained.
  • the other composite particle group may be one or plural.
  • the number of composite particle groups and the volume average particle diameter of each composite particle group can be adjusted by changing the classification method and classification conditions of the composite particles in the step (B).
  • the composite particle group A obtained in the step (B) needs to have a maximum volume average particle size
  • the composite particle group B obtained in the step (B) needs to have a minimum volume average particle size.
  • the “maximum / minimum volume average particle diameter” means the maximum / minimum of the volume average particle diameters measured for each composite particle group of at least two composite particle groups obtained by classifying the composite particles. Pointing is a relative concept.
  • the volume average particle diameter is ⁇ ⁇ m.
  • a certain composite particle group becomes the composite particle group A
  • a composite particle group whose volume average particle diameter is ⁇ ⁇ m becomes the composite particle group B.
  • the volume average particle diameters of the two composite particle groups obtained by classification are 100 ⁇ m and 800 ⁇ m, respectively
  • the composite particle group having a volume average particle diameter of 800 ⁇ m becomes the composite particle group A
  • the volume average particle A composite particle group having a diameter of 100 ⁇ m becomes a composite particle group B ⁇ Group 1>.
  • the composite particle group having a volume average particle diameter of 800 ⁇ m becomes the composite particle group A.
  • the composite particle group having a volume average particle diameter of 200 ⁇ m becomes the composite particle group B ⁇ Group 2>.
  • the composite particle group having a volume average particle diameter of 1000 ⁇ m is the composite particle group A composite particle group having a volume average particle diameter of 200 ⁇ m and A is a composite particle group B ⁇ Group 3>.
  • volume average particle size of the composite particle group A and the composite particle B varies depending on the particle size range to be classified.
  • the “volume average particle diameter” of the composite particle group refers to the above-described D50, and can be measured using the above-described laser diffraction / scattering particle diameter distribution measuring apparatus.
  • composite particle groups that can be obtained in the step (B) are any number of composite particle groups having a volume average particle diameter between the maximum volume average particle diameter and the minimum volume average particle diameter. That is, in the above ⁇ Group 1>, no other composite particle group exists, and in the above ⁇ Group 2>, the composite particle group having a volume average particle diameter of 400 ⁇ m becomes the other composite particle group. In the above ⁇ Group 3>, the two composite particle groups having a volume average particle diameter of 400 ⁇ m and 800 ⁇ m are the other composite particle groups, respectively.
  • the classification is not particularly limited as long as the obtained composite particles can be separated.
  • sieve classification forced vortex type centrifugal classifier (micron separator, turboplex, turbo classifier, super separator)
  • An air classifier such as an inertia classifier (an improved virtual impactor, elbow jet) can be used.
  • a wet sedimentation method, a centrifugal classification method, or the like can also be used.
  • a sieving method having a desired mesh opening is preferable, and the sieving method is more preferably performed manually.
  • the classification temperature is not particularly limited, and can be performed, for example, at 25 ° C.
  • the composite particles for pressurization are prepared by using the composite particles contained in the composite particle groups other than the composite particle group A among the composite particle groups obtained in the step (B).
  • “use composite particles contained in a composite particle group other than the composite particle group A” is included in the composite particle group B obtained by classification in the above ⁇ Group 1>, for example. This refers to preparing composite particles for pressurization using only composite particles (that is, removing composite particle group A from the entire composite particles obtained in step (A)).
  • the composite particles contained in the composite particle group B and other composite particle groups is used (that is, at least the composite particle group A is used in the step (A)).
  • a composite particle for pressurization is prepared by removing from the entire composite particle obtained). That is, in the above ⁇ Group 2>, the composite particles for pressurization may be prepared using the composite particles contained in the composite particle group B and other composite particle groups, or included in the composite particle group B. The composite particles for pressurization may be prepared using only the composite particles that are present, or the composite particles for pressurization may be prepared using only the composite particles contained in other composite particle groups.
  • the step (C) it is necessary to remove at least the composite particle group A from the composite particle group used for preparing the pressurizing composite particles. Further, the step (C) is to remove the composite particle group (composite particle group B and / or other composite particle group) other than the composite particle group A from the composite particle group used for preparing the composite particles for pressurization. Do not limit.
  • the composite particle group B and the other composite particles are prepared. Particle groups can be mixed and used at an arbitrary ratio. Moreover, the mixing of the composite particles at that time can be performed using a known mixing method.
  • composite particles contained in at least one of the composite particle group B and two other composite particle groups are used (that is, at least the composite particle group A is converted into the step (A). Remove from the whole composite particles obtained in step)) to prepare composite particles for pressurization. That is, in the above ⁇ Group 3>, the composite particles for pressurization may be prepared using the composite particles contained in the composite particle group B and the two other composite particle groups. In the above ⁇ Group 3>, the composite particles for pressurization may be prepared using the composite particles contained in any one of the composite particle group B and two other composite particle groups. You may prepare the pressurization composite particle only using the composite particle contained in two other composite particle groups.
  • the composite particles for pressurization may be prepared using only the composite particles contained in any one of the composite particle group B and two other composite particle groups.
  • the composite particle group B and / or other composite particle groups used for preparing the composite particles for pressurization can be mixed at an arbitrary ratio.
  • the pressurizing composite particles obtained in the pressurizing composite particle preparation step including the steps (A), (B), and (C) described above are predetermined composite particles excluding at least a coarse composite particle group. Since it is prepared using the composite particles contained in the group, when the composite particles for pressurization are pressed, the manufactured composite material sheet can exhibit excellent thermal conductivity. In addition, the manufactured composite material sheet can exhibit excellent strength and hardness. The reason for this is not clear, but is presumed to be as follows. That is, generally, in a molded body such as a sheet formed by pressurizing a composite material containing a particulate carbon material and a resin, the particulate carbon materials are in contact with each other to form a heat transfer path with excellent thermal conductivity.
  • an aggregate of composite particles having a large particle size difference in which large particle size particles and small particle size particles are mixed Will be pressurized.
  • an aggregate of particles having a large particle size difference is pressurized, it is difficult to apply a uniform pressure to each particle.
  • the small particle diameter particles easily flow through the gaps between the large particle diameter particles during pressurization, it is difficult to apply a large shear force to the aggregate of the particles.
  • the manufactured composite material sheet has a good heat transfer path along the in-plane direction, and can exhibit high thermal conductivity particularly having in-plane orientation.
  • the particulate carbon material and the resin are uniformly combined. Therefore, when the above-mentioned uniform pressure is applied to the composite particles, not only the granular carbon materials but also the resins come into contact with each other in a good blended state, so that the manufactured composite material sheet has excellent strength and flexibility. It can be demonstrated.
  • the volume average particle diameter of the composite particle group including the composite particles used in the step (C) is preferably 500 ⁇ m or less, more preferably 400 ⁇ m or less, further preferably 350 ⁇ m or less, and 300 ⁇ m or less. It is more preferable that the thickness is 150 ⁇ m or more. If pressurizing composite particles for pressurization obtained using composite particles contained in a relatively small composite particle group whose volume average particle diameter is not more than the above upper limit, as described above, thermal conductivity, strength, and hardness are further increased. This is because an improved composite material sheet can be produced.
  • the volume average particle diameter of the composite particle group is 150 ⁇ m or more, it is possible to suppress the formation of heat transfer paths that are difficult to contact with each other in an excessively small particle, so that good thermal conductivity is achieved. It is because it is obtained.
  • the composite particles for pressurization obtained in the step (C) constitute a composite material sheet through a pressurization step described later.
  • the composite particle for pressurization obtained at a process (C) is prepared using the composite particle contained in composite particle groups other than the composite particle group A as above-mentioned. And by pressurizing the composite particles for press obtained using the composite particles contained in a relatively small composite particle group other than the composite particle group A, the composite material sheet to be manufactured has high thermal conductivity, high strength, and Good hardness can be given.
  • the content of the composite particles having a particle diameter of 500 ⁇ m or more is preferably less than 40% by volume, more preferably less than 35% by volume, and further preferably less than 25% by volume. preferable.
  • thermal conductivity This is because a composite material sheet with further improved strength and hardness can be produced.
  • the particle size distribution of the pressurizing composite particles can be adjusted by changing the method of classifying the composite particles in the step (B) and the method of combining the composite particle groups used for preparing the pressurizing composite particles.
  • seat of this invention is a pressurization process which obtains a composite material sheet
  • pressurization is not particularly limited as long as it is a molding method in which pressure is applied to the pressurizing composite particles, and a known molding method such as press molding, rolling molding or extrusion molding can be performed. Especially, it is preferable to shape
  • a protective film it does not specifically limit, The polyethylene terephthalate (PET) film which performed the sandblasting process, the PET film which performed the silicone mold release process, etc. can be used.
  • the roll temperature is 5 ° C. or more and 150 ° C.
  • the roll gap is 50 ⁇ m or more and 2500 ⁇ m or less
  • the roll linear pressure is 1 kg / cm or more and 3000 kg / cm or less
  • the roll speed is 0.1 m / min or more and 20 m / min or less. it can.
  • the composite material sheet manufactured using the above-described manufacturing method improves the thermal conductivity particularly in the in-plane direction.
  • the composite material sheet manufactured using the said manufacturing method is excellent also in intensity
  • the thickness of a composite material sheet is not specifically limited, For example, it can be 0.05 mm or more and 2 mm or less. Further, from the viewpoint of further improving the thermal conductivity of the composite material sheet, the thickness of the composite material sheet is more than 1 time and not more than 5000 times the volume standard mode diameter of the particulate carbon material used for manufacturing the composite material sheet. It is preferable.
  • Method for producing heat conductive sheet In the manufacturing method of the heat conductive sheet of this invention, the process (lamination process) of obtaining a laminated body using the composite material sheet manufactured by the manufacturing method of the composite material sheet of this invention, and the process of slicing a laminated body (for example) Through the slicing step, a heat conductive sheet can be manufactured.
  • a laminating step and a slicing step By subjecting the above-mentioned composite material sheet to a laminating step and a slicing step, it is possible to produce a heat conductive sheet excellent in all of the heat conductivity, strength, and hardness in the sheet thickness direction.
  • each step will be specifically described.
  • ⁇ Lamination process> In the step of obtaining a laminate (lamination step), a plurality of composite material sheets manufactured using the above-described composite material sheet manufacturing method are stacked in the thickness direction, or the above-described composite material sheet manufacturing method is used. The manufactured composite material sheet is folded or wound to obtain a laminate.
  • seat is not specifically limited, You may carry out using a lamination apparatus, and may carry out manually.
  • formation of the laminated body by folding of a composite material sheet is not specifically limited, It can carry out by folding a composite material sheet by fixed width using a folding machine.
  • the formation of the laminate by winding the composite material sheet is not particularly limited, and can be performed by winding the composite material sheet around an axis parallel to the short side direction or the long side direction of the composite material sheet. it can.
  • the adhesive force between the surfaces of the composite material sheet is sufficiently obtained by the pressure at the time of laminating the composite material sheet and the pulling force at the time of folding or winding.
  • the lamination step may be performed in a state where the surface of the composite material sheet is slightly dissolved with a solvent
  • the laminating step may be performed in a state where an adhesive is applied to the surface of the composite material sheet or an adhesive layer is provided on the surface of the composite material sheet.
  • the solvent used for dissolving the surface of the composite material sheet is not particularly limited, and a known solvent (for example, methyl ethyl ketone) that can dissolve the resin contained in the composite material sheet is used. Can do.
  • coated to the surface of a composite material sheet A commercially available adhesive agent and adhesive resin can be used.
  • the adhesive layer provided on the surface of the composite material sheet is not particularly limited, and a double-sided tape or the like can be used.
  • an adhesive layer it is preferable to provide the adhesive layer which has an acrylic adhesive which is excellent in adhesiveness.
  • coated to the surface of a composite material sheet or the contact bonding layer provided in the surface of a composite material sheet can be 1 micrometer or more and 1000 micrometers or less, for example.
  • the heat conductive filler may be mix
  • the obtained laminate is heated at 50 ° C. or more and 170 ° C. or less for 10 minutes to 8 hours while being pressed at a pressure of 0.1 MPa or more and 0.5 MPa or less in the lamination direction. Also good.
  • the particulate carbon material and any fibrous carbon material are arranged in a direction substantially perpendicular to the laminating direction.
  • the heat transfer path formed by the good contact between the particulate carbon materials or between the particulate carbon material and the fibrous carbon material is arranged mainly in a direction substantially orthogonal to the lamination direction. It is guessed.
  • the laminated body obtained in the above-described laminating step is sliced at an angle of 45 ° or less with respect to the laminating direction to obtain a heat conductive sheet composed of sliced pieces of the laminated body.
  • the method for slicing the laminate is not particularly limited, and examples thereof include a wire saw method, a multi-blade method, a laser processing method, a water jet method, and a knife processing method.
  • the knife processing method is preferable at the point which makes the thickness of a heat conductive sheet uniform.
  • the cutting tool for slicing the laminate is not particularly limited, and includes a slice member (for example, a sharp blade) having a smooth board surface having a slit and a blade portion protruding from the slit portion.
  • a slice member for example, a sharp blade
  • Cutter, canna, slicer can be used.
  • the angle at which the laminate is sliced is preferably 30 ° or less with respect to the stacking direction, and more preferably 15 ° or less with respect to the stacking direction. Preferably, it is substantially 0 ° with respect to the stacking direction (that is, a direction along the stacking direction).
  • the temperature of the laminate when slicing is preferably ⁇ 20 ° C. or more and 80 ° C. or less, and more preferably ⁇ 10 ° C. or more and 50 ° C. or less.
  • the laminated body to be sliced is preferably sliced while applying a pressure in a direction perpendicular to the lamination direction, and a pressure of 0.05 MPa to 0.5 MPa in a direction perpendicular to the lamination direction. It is more preferable to slice while loading.
  • the particulate carbon material and any fibrous carbon material are substantially orthogonal to the thickness direction of the heat conductive sheet (that is, the lamination direction of the composite material sheet as the pre heat conductive sheet). It is inferred that they are arranged in the direction of Moreover, in the said heat conductive sheet, the heat-transfer path
  • a suspension containing expanded graphite as a particulate carbon material was obtained.
  • the particle diameter of the expanded graphite contained in the obtained suspension was measured using a laser diffraction / scattering particle size distribution measuring apparatus (manufactured by Horiba, model number “LA-960”).
  • the hardness of the composite material sheet was evaluated as the hardness of a specimen (composite material sheet layer) in which a plurality of composite material sheets were stacked.
  • the hardness was measured according to the Asker C method of the Japan Rubber Association Standard (SRIS).
  • SRIS Japan Rubber Association Standard
  • the composite material sheets obtained in Examples and Comparative Examples were cut into a size of 25 mm wide ⁇ 50 mm long ⁇ 0.5 mm thick, and a test piece was obtained by stacking 24 sheets.
  • the obtained test piece was allowed to stand in a temperature-controlled room maintained at a temperature of 23 ° C. for 48 hours or longer to obtain a composite material sheet layer as a test body.
  • the Asker C hardness of the composite material sheet layer 60 seconds after the collision was measured twice using a hardness meter (product name “ASKER CL-150LJ” manufactured by Kobunshi Keiki Co., Ltd.), and the average value of the measurement results was adopted. did. The smaller the Asker C hardness, the more flexible and excellent the composite sheet. The results are shown in Table 1.
  • thermal diffusivity (alpha) (m ⁇ 2 > / s) of thickness direction, constant-pressure specific heat Cp (J / g * K), and specific gravity (rho) (g / m ⁇ 3 >) are the following methods. Measured with [Thermal diffusivity] The thermal diffusivity at a temperature of 25 ° C. was measured using a thermophysical property measuring apparatus (product name “Thermo Wave Analyzer TA35” manufactured by Bethel Co., Ltd.).
  • Example 1 ⁇ Preparation process of composite particles for pressurization> [Step (A)] [[Kneading stage]] 130 parts of expanded graphite (product name “EC-50”, average particle size: 250 ⁇ m) as a particulate carbon material, 1 part of a CNT easy dispersion aggregate as a fibrous carbon material, 80 parts of fluororesin (made by Daikin Industries, product name “DAIEL G-912”) as resin, and 10 parts of phosphoric ester (product name “LEOFOS 65”, manufactured by Ajinomoto Fine Techno Co., Ltd.) as flame retardant The mixture was stirred and kneaded at 50 ° C.
  • the used CNT easy-dispersed aggregate was prepared by the following method.
  • a fibrous carbon material containing SGCNT was obtained by the above-described super-growth method.
  • the obtained fibrous carbon material had a BET specific surface area of 800 m 2 / g. Further, as a result of measuring the diameter and length of 100 randomly selected fibrous carbon materials using a transmission electron microscope, the average diameter was 3.3 nm and the average length was 100 ⁇ m. Furthermore, the obtained fibrous carbon material was mainly composed of single-walled CNTs. Next, by removing the solvent from the dispersion obtained by dispersing the obtained fibrous carbon material in methyl ethyl ketone as a dispersion medium using a filter paper (Kiriyama Co., No. 5A) under reduced pressure.
  • a CNT easy-dispersed aggregate containing SGCNT was obtained. Since a fibrous carbon material such as CNT is generally easily aggregated, mixing with other components can be facilitated by setting it in such a state of an easily dispersible aggregate.
  • Step (B) The composite particles obtained above are classified at 25 ° C. using sieves (manufactured by Tokyo Screen, openings: 150 ⁇ m, 250 ⁇ m), so that each of composite particle groups A (on a sieve having openings of 250 ⁇ m), composite particles Three composite particle groups were obtained: Group B (under a sieve having an opening of 150 ⁇ m) and other composite particles (aperture: above a sieve of 150 ⁇ m and under a sieve of 250 ⁇ m).
  • Step (C) Of the three composite particle groups obtained above, the composite particle group A and the composite particle group B were removed, and only the composite particles contained in the other composite particle groups were directly employed as the pressurizing composite particles. Then, the volume average particle size of the employed composite particle group (that is, the composite particle for pressurization) and the content ratio of the composite particle having a particle size of 500 ⁇ m or more in the obtained composite particle for pressurization were calculated. The results are shown in Table 1.
  • strength and hardness (Asker C hardness) of the obtained composite material sheet were measured. The results are shown in Table 1.
  • ⁇ Lamination process> A double-sided tape (manufactured by Nichiei Kako, product name “NeoFix10”, thickness: 10 ⁇ m) was attached to any one side of the composite material sheet obtained above. Next, by combining the surface side of the composite material sheet on which the double-sided tape is applied and the surface side of another composite material sheet on which the double-sided tape is not applied, and repeating the same operation for 120 sheets, the thickness is increased. A laminate of about 6 cm was obtained. The obtained laminate was compressed by hand, and the adhesive surfaces of the composite material sheet were brought into close contact with each other.
  • step (B) classification is performed using sieves having mesh openings of 150 ⁇ m, 250 ⁇ m, and 500 ⁇ m, so that composite particle group A (on a sieve having an opening of 500 ⁇ m) and composite particle group B (a sieve having an opening of 150 ⁇ m) are obtained. Lower), four composite particle groups of other composite particle group C (upper and 150 ⁇ m sieve openings) and other composite particle group D (up and 250 ⁇ m sieve openings) Got.
  • step (C) among the obtained four composite particle groups, composite particle group A and composite particle B were removed, and other composite particle group C and other composite particle group D were employed. And the composite particle for pressurization was obtained by mixing the composite particle contained in the said 2 composite particle group by mass ratio 1: 1.
  • Example 1 Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
  • step (B) classification is performed using a sieve having mesh openings of 250 ⁇ m and 500 ⁇ m, so that composite particle group A (on a sieve having an opening of 500 ⁇ m) and composite particle group B (under a sieve having an opening of 250 ⁇ m), respectively. , And other composite particle groups (upper sieve having a sieve opening of 250 ⁇ m and lower sieve of 500 ⁇ m) were obtained. Further, in the step (C), among the obtained three composite particle groups, the composite particle group A and the composite particle B are removed, and only the composite particles contained in the other composite particle groups are employed as they are. Composite particles for pressurization were obtained.
  • Example 1 Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
  • Example 1 The composite particles for pressurization were obtained by directly adopting the composite particles obtained after the pulverization stage (that is, not classified) without performing the steps (B) and (C). Except for the above, a kneaded product, composite particles, composite particles for pressurization, a composite material sheet, and a heat conductive sheet were produced in the same manner as in Example 1. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
  • step (B) by classifying using a sieve having a mesh opening of 500 ⁇ m, each of composite particle group A (on a sieve having an opening of 500 ⁇ m) and composite particle group B (below a sieve having an opening of 500 ⁇ m) Two composite particle groups were obtained. Further, in step (C), among the obtained two composite particle groups, the composite particle group B was removed, and only the composite particles contained in the composite particle group A were employed to obtain composite particles for pressurization. . Except for the above, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced in the same manner as in Example 1. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
  • step (B) classification is performed using sieves having mesh openings of 150 ⁇ m, 250 ⁇ m, and 500 ⁇ m, so that composite particle group A (on a sieve having an opening of 500 ⁇ m) and composite particle group B (a sieve having an opening of 150 ⁇ m) are obtained.
  • step (C) four composite particle groups of other composite particle group C (upper sieve of 150 ⁇ m opening and under 250 ⁇ m sieve) and composite particle group D (upper sieve of 250 ⁇ m opening and under 500 ⁇ m sieve) are obtained. It was. Further, in the step (C), among the obtained four composite particle groups, the composite particle group B and the other composite particle group D were removed, and the composite particle group A and the other composite particle group C were adopted.
  • the composite particle for pressurization was obtained by mixing the composite particle contained in the said 2 composite particle group by mass ratio 1: 1. Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
  • step (B) by classifying using a sieve having a mesh opening of 250 ⁇ m and 500 ⁇ m, composite particle group A (on a sieve having an opening of 500 ⁇ m) and other composite particle groups (on a sieve having an opening of 250 ⁇ m) And a composite particle group B of a composite particle group B (under a sieve having an opening of 250 ⁇ m) was obtained.
  • step (C) only the composite particle group B was removed from the obtained three composite particle groups, and the composite particle group A and the other composite particle groups were employed. And the composite particle for pressurization was obtained by mixing the composite particle contained in the said 2 composite particle group by mass ratio 1: 1.
  • Example 1 Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
  • step (B) classification is performed using sieves having mesh openings of 150 ⁇ m, 250 ⁇ m, and 500 ⁇ m, so that composite particle group A (on a sieve having an opening of 500 ⁇ m) and composite particle group B (a sieve having an opening of 150 ⁇ m) are obtained.
  • step (C) four composite particle groups of other composite particle group C (upper sieve of 150 ⁇ m opening and under 250 ⁇ m sieve) and composite particle group D (upper sieve of 250 ⁇ m opening and under 500 ⁇ m sieve) are obtained. It was. Further, in the step (C), among the obtained four composite particle groups, the composite particle group B and the other composite particle group D were removed, and the composite particle group A and the other composite particle group C were adopted.
  • strength, and favorable hardness can be provided.
  • strength, and favorable hardness can be provided.

Abstract

Provided is a method for producing a composite material sheet which achieves a good balance among high thermal conductivity, high strength and good hardness. A method for producing a composite material sheet according to the present invention comprises: a preparation step of composite particles for pressurization; and a pressurization step for applying a pressure to the composite particles for pressurization. The preparation step comprises: (A) a step for preparing composite particles, each of which contains a particulate carbon material and a resin; (B) a step for classifying the composite particles into at least two composite particle groups including specific composite particle groups A and B; and (C) a step for preparing the composite particles for pressurization with use of composite particles that are contained in composite particle groups other than the composite particle group A.

Description

複合材料シートおよび熱伝導シートの製造方法COMPOSITE MATERIAL SHEET AND METHOD FOR PRODUCING HEAT CONDUCTIVE SHEET
　本発明は、複合材料シートの製造方法および熱伝導シートの製造方法に関する。 The present invention relates to a method for manufacturing a composite material sheet and a method for manufacturing a heat conductive sheet.
　近年、熱伝導性および導電性などの機能性を有する複合材料を用いたシート状の部材（複合材料シート）が、種々の用途に用いられている。 In recent years, a sheet-like member (composite material sheet) using a composite material having functions such as thermal conductivity and conductivity has been used for various applications.
　例えば、電子機器の高性能化に伴う電子部品の発熱量の増大により電子部品の温度が上昇し、電子機器に機能障害をもたらすことがある。このような温度上昇による機能障害への対策としては、電子部品等の発熱体に対し、金属製のヒートシンク、放熱板、放熱フィン等の放熱体を取り付けることによって、放熱を促進させる方法が採られている。そして、放熱体を使用する際には、発熱体から放熱体へと熱を効率的に伝えるために、熱伝導性が高い熱伝導シートを介して発熱体と放熱体とを密着させている。ここで、当該熱伝導シートとして、熱伝導性に優れる複合材料シートを用いて成形したシートが用いられている。 For example, the temperature of an electronic component may rise due to an increase in the amount of heat generated by the electronic component due to the high performance of the electronic device, resulting in a functional failure in the electronic device. As a countermeasure against such functional failure due to temperature rise, a method of promoting heat dissipation by attaching a heat sink such as a metal heat sink, heat sink, heat sink or the like to a heat generator such as an electronic component is adopted. ing. And when using a heat radiator, in order to transmit heat | fever efficiently from a heat generating body to a heat radiator, the heat generating body and the heat radiator are closely_contact | adhered via the heat conductive sheet with high heat conductivity. Here, the sheet | seat shape | molded using the composite material sheet | seat excellent in heat conductivity is used as the said heat conductive sheet.
　また、例えば、電子機器同士が相互干渉することによって生じる電磁ノイズ、または静電気が、電子機器に機能障害をもたらすことがある。このような機能障害への対策としては、導電性が高い複合材料シートを、電子機器または電子部品に直接取り付ける部材、或いは、電子機器または電子部品に接触する部材（梱包材など）として用いることができる。導電性が高い複合材料シートの利用により、電子機器間に発生するノイズ伝播の防止および帯電防止などを図ることができる。 Also, for example, electromagnetic noise generated by mutual interference between electronic devices or static electricity may cause a functional failure in the electronic device. As a countermeasure against such a functional failure, a highly conductive composite material sheet may be used as a member that is directly attached to an electronic device or an electronic component, or a member that contacts the electronic device or the electronic component (such as a packing material). it can. By using the composite material sheet having high conductivity, it is possible to prevent noise propagation generated between electronic devices and prevent charging.
　従って、複合材料シートには、高い熱伝導性および／または高い導電性を、望ましくは用途および使用箇所に応じた配向性をもって発揮することが求められている。 Therefore, the composite material sheet is required to exhibit high thermal conductivity and / or high conductivity, preferably with orientation according to the application and use location.
　例えば、特許文献１では、エラストマー成分、ラジカル反応性樹脂、および熱伝導性材料を混練してなる導電性硬化性樹脂組成物をロールによりプレス成形することで、熱伝導性および導電性に優れた、複合材料からなるシートを得る技術が開示されている。ここで、特許文献１では、前記熱伝導性材料として、予めコークスを粉砕し、必要に応じて分級することにより粒子径５μｍ以下の粒子を除去した後に当該コークスを黒鉛化してなるホウ素含有黒鉛微粉を用いている。そして、特許文献１では、このように予めコークスを粉砕、分級して所望の粒径としたホウ素含有黒鉛微粉をエラストマー成分と併用することで、シート面内の高い導電性（低い抵抗）および高い放熱性（高い熱伝導性）を兼ね備え、且つ、炭素材料を高充填しても厚み精度が高いシートの成形を実現している。 For example, in Patent Document 1, a conductive curable resin composition obtained by kneading an elastomer component, a radical reactive resin, and a heat conductive material is press-molded with a roll, thereby being excellent in heat conductivity and conductivity. A technique for obtaining a sheet made of a composite material is disclosed. Here, in Patent Document 1, as the thermally conductive material, coke is pulverized in advance and classified as necessary, and then particles having a particle diameter of 5 μm or less are removed, and then the coke is graphitized. Is used. And in patent document 1, the high electroconductivity (low resistance) in a sheet surface and high are used by using together the elastomer component with the boron containing graphite fine powder which grind | pulverized and classified the coke beforehand and made it the desired particle size in this way. A sheet having high heat dissipation (high thermal conductivity) and high thickness accuracy is realized even if the carbon material is highly filled.
特開２００３－１７６３２７号公報JP 2003-176327 A
　ここで、複合材料シートには、高い熱伝導性および／または導電性に加え、取り付けられた際に非接触体と隙間なく良好に接触するための高い可撓性、並びに、シートの薄膜化を可能とし得る高い強度を有することも求められている。しかしながら、特許文献１などに記載の従来のシートでは、強度および可撓性が十分ではなかった。 Here, in addition to high thermal conductivity and / or conductivity, the composite material sheet has high flexibility to make good contact with a non-contacting body without any gap when attached, and thinning of the sheet. There is also a need to have a high strength that can be made possible. However, the conventional sheets described in Patent Document 1 and the like have not been sufficient in strength and flexibility.
　そこで、本発明は、高い熱伝導性を確保しつつ、高い強度および良好な可撓性（低い硬度）を並立させた、複合材料シートの製造方法並びに熱伝導シートの製造方法を提供することを目的とする。 Therefore, the present invention provides a method for manufacturing a composite material sheet and a method for manufacturing a heat conductive sheet, in which high thermal conductivity is ensured and high strength and good flexibility (low hardness) are arranged side by side. Objective.
　本発明者らは、上記目的を達成するために鋭意検討を行った。そして本発明者らは、熱伝導性材料自体ではなく、熱伝導性材料および樹脂を含む複合粒子を分級し、少なくとも粗大な複合粒子を含む複合粒子群を取り除くことに着目した。そして、残った複合粒子群に含まれる複合粒子に対して圧力を加えてシート成形することにより、高い熱伝導性、高い強度、および低いアスカーＣ硬度（以下、単に「硬度」ということがある。）を並立する複合材料シートを製造し得ることを見出し、本発明を完成させた。また、本発明者らは、当該複合材料シートを活用して熱伝導性に優れる熱伝導シートを製造し得ることを見出し、本発明を完成させた。
　なお、本発明において「良好な硬度」、「優れた硬度」、「硬度の向上」等とは、アスカーＣ硬度が低い値であることを意味する。 The present inventors have intensively studied to achieve the above object. The inventors of the present invention focused on classifying the composite particles including the heat conductive material and the resin, not the heat conductive material itself, and removing the composite particle group including at least coarse composite particles. Then, by applying pressure to the composite particles contained in the remaining composite particle group to form a sheet, high thermal conductivity, high strength, and low Asker C hardness (hereinafter simply referred to as “hardness”) may be used. ), The present invention has been completed. In addition, the present inventors have found that a heat conductive sheet having excellent heat conductivity can be produced using the composite material sheet, and have completed the present invention.
In the present invention, “good hardness”, “excellent hardness”, “improvement of hardness” and the like mean that the Asker C hardness is a low value.
　すなわち、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の複合材料シートの製造方法は、加圧用複合粒子を得る加圧用複合粒子の準備工程と、前記加圧用複合粒子を加圧することで複合材料シートを得る加圧工程とを含む複合材料シートの製造方法であって、前記加圧用複合粒子の準備工程が、粒子状炭素材料および樹脂を含有する複合粒子を準備する工程（Ａ）と、準備した前記複合粒子を、最大体積平均粒子径を有する複合粒子群Ａおよび最小体積平均粒子径を有する複合粒子群Ｂを含む少なくとも２つの複合粒子群に分級する工程（Ｂ）と、前記複合粒子群のうち前記複合粒子群Ａ以外の複合粒子群に含まれる複合粒子を用いて前記加圧用複合粒子を準備する工程（Ｃ）とを含むことを特徴とする。
　このように、複合粒子を分級した後、最大体積平均粒子径を有する複合粒子群Ａ以外の複合粒子群に含まれている複合粒子を用いて得られる加圧用複合粒子を加圧することにより、熱伝導性、強度、および硬度に優れる複合材料シートを提供することができる。
　なお、本発明において「体積平均粒子径」とは、レーザー回折法で測定された粒子径分布（体積基準）において小径側から計算した累積体積が５０％となる粒子径（Ｄ５０）を表す。また、本発明において「体積平均粒子径」は、レーザー回折／散乱式粒子径分布測定装置を用いて測定することができる。 That is, the present invention aims to advantageously solve the above-mentioned problems, and the method for producing a composite material sheet of the present invention comprises a step of preparing a composite particle for pressurization to obtain a composite particle for pressurization, A method of producing a composite material sheet comprising a pressurizing step of obtaining a composite material sheet by pressurizing the composite particles for pressure, wherein the preparatory step of the composite particles for pressurization includes a particulate carbon material and a resin. And the prepared composite particles are classified into at least two composite particle groups including a composite particle group A having a maximum volume average particle diameter and a composite particle group B having a minimum volume average particle diameter. A step (B) and a step (C) of preparing the pressurizing composite particles using composite particles contained in a composite particle group other than the composite particle group A among the composite particle groups. .
Thus, after classifying the composite particles, by pressurizing the composite particles for press obtained using the composite particles contained in the composite particle group other than the composite particle group A having the maximum volume average particle diameter, A composite material sheet having excellent conductivity, strength, and hardness can be provided.
In the present invention, the “volume average particle diameter” represents a particle diameter (D50) at which the cumulative volume calculated from the small diameter side is 50% in the particle diameter distribution (volume basis) measured by the laser diffraction method. In the present invention, the “volume average particle size” can be measured using a laser diffraction / scattering particle size distribution measuring apparatus.
　ここで、本発明の複合材料シートの製造方法では、前記工程（Ｃ）において用いられる複合粒子を含む複合粒子群の体積平均粒子径が５００μｍ以下であることが好ましい。体積平均粒子径が５００μｍ以下の複合粒子群に含まれる複合粒子を用いて加圧用複合粒子を準備すれば、熱伝導性、強度、および硬度を更に向上させた複合材料シートが得られるからである。 Here, in the method for producing a composite material sheet of the present invention, the volume average particle diameter of the composite particle group including the composite particles used in the step (C) is preferably 500 μm or less. This is because if a composite particle for pressurization is prepared using composite particles contained in a composite particle group having a volume average particle diameter of 500 μm or less, a composite material sheet with further improved thermal conductivity, strength, and hardness can be obtained. .
　また、本発明の複合材料シートの製造方法では、前記加圧用複合粒子は、粒子径５００μｍ以上の複合粒子の含有率が４０体積％未満であることが好ましい。加圧用複合粒子中の粒子径５００μｍ以上の複合粒子の割合を４０体積％未満とすれば、熱伝導性、強度、および硬度が更に向上した複合材料シートが得られるからである。
　なお、上述した本発明において、加圧用複合粒子中の「複合粒子の含有率」は、上述のレーザー回折／散乱式粒子径分布測定装置を用いて得られる体積基準の粒子径分布から算出することができる。 In the method for producing a composite material sheet of the present invention, it is preferable that the pressurizing composite particles have a content of composite particles having a particle diameter of 500 μm or more of less than 40% by volume. This is because if the ratio of the composite particles having a particle diameter of 500 μm or more in the composite particles for pressurization is less than 40% by volume, a composite material sheet with further improved thermal conductivity, strength, and hardness can be obtained.
In the present invention described above, the “composite particle content” in the composite particles for pressurization is calculated from the volume-based particle size distribution obtained using the laser diffraction / scattering particle size distribution measuring device described above. Can do.
　また、本発明の複合材料シートの製造方法では、前記複合粒子が、前記粒子状炭素材料１００質量部に対して前記樹脂を５０質量部以上１５０質量部以下含有することが好ましい。複合粒子中の樹脂の含有量を上記範囲に制御することにより、熱伝導性、強度、および硬度が良好な複合材料シートが容易に得られるからである。 Moreover, in the method for producing a composite material sheet of the present invention, it is preferable that the composite particles contain 50 parts by mass or more and 150 parts by mass or less of the resin with respect to 100 parts by mass of the particulate carbon material. This is because a composite material sheet having good thermal conductivity, strength, and hardness can be easily obtained by controlling the resin content in the composite particles within the above range.
　そして、本発明の複合材料シートの製造方法は、前記工程（Ａ）が、前記粒子状炭素材料および前記樹脂を混練して混練物を得る混練段階と、前記混練物を粉砕して前記複合粒子を得る粉砕段階とを含むことが好ましい。上記混練段階および粉砕段階を経ることにより、本発明の複合材料シートの製造方法に用いられる複合粒子を容易に調製することができるからである。 In the method for producing a composite material sheet of the present invention, the step (A) includes a kneading step in which the particulate carbon material and the resin are kneaded to obtain a kneaded product, and the kneaded product is pulverized to form the composite particles. It is preferable to include a pulverizing step. This is because the composite particles used in the method for producing a composite material sheet of the present invention can be easily prepared through the kneading step and the pulverization step.
　また、この発明は、上記課題を有利に解決することを目的とするものであり、本発明の熱伝導シートの製造方法は、上述したいずれかの製造方法で得られた前記複合材料シートを厚み方向に複数枚積層して、或いは、上述したいずれかの製造方法で得られた前記複合材料シートを折畳または捲回して、積層体を得る工程（積層工程）と、前記積層体を、積層方向に対して４５°以下の角度でスライスし、熱伝導シートを得るスライス工程とを含むことを特徴とする。このように、得られた複合材料シートに対して積層工程およびスライス工程を施すことにより、厚み方向の熱伝導性が高く、且つ、高い強度および良好な硬度を有する熱伝導シートを製造し得る。 Moreover, this invention aims at solving the said subject advantageously, The manufacturing method of the heat conductive sheet of this invention is thickness of the said composite material sheet obtained by one of the manufacturing methods mentioned above. Laminating the laminated body by laminating a plurality of sheets in the direction or by folding or winding the composite material sheet obtained by any of the manufacturing methods described above to obtain a laminated body And a slicing step of obtaining a heat conductive sheet by slicing at an angle of 45 ° or less with respect to the direction. Thus, by performing a lamination | stacking process and a slicing process with respect to the obtained composite material sheet | seat, the heat conductive sheet which has high thermal conductivity of the thickness direction, and has high intensity | strength and favorable hardness can be manufactured.
　本発明によれば、高い熱伝導性、高い強度、および良好な硬度を並立させた複合材料シートの製造方法を提供することができる。また、本発明によれば、高い熱伝導性、高い強度、および良好な硬度を並立させた熱伝導シートの製造方法を提供することができる。 According to the present invention, it is possible to provide a method for producing a composite material sheet in which high thermal conductivity, high strength, and good hardness are arranged side by side. Moreover, according to this invention, the manufacturing method of the heat conductive sheet which made parallel high heat conductivity, high intensity | strength, and favorable hardness can be provided.
　以下、本発明の実施形態について詳細に説明する。
　本発明の複合材料シートの製造方法は、樹脂と粒子状炭素材料とを含む複合材料シートを製造する際に用いることができる。そして、本発明の複合材料シートの製造方法を用いて製造した複合材料シートは、特に限定されることなく、熱伝導性や導電性に優れるシート状の部材として、各種用途に用いることができる。
　また、本発明の複合材料シートの製造方法により製造された複合材料シートは、本発明の熱伝導シートの製造方法に従って熱伝導シートを製造する際に用いることができる。そして、本発明の熱伝導シートの製造方法を用いて製造した熱伝導シートは、発熱体に放熱体を取り付ける際に発熱体と放熱体との間に挟み込んで使用することができる。即ち、本発明の熱伝導シートの製造方法を用いて製造した熱伝導シートは、ヒートシンク、放熱板、放熱フィン等の放熱体と共に放熱装置を構成することができる。 Hereinafter, embodiments of the present invention will be described in detail.
The method for producing a composite material sheet of the present invention can be used when producing a composite material sheet containing a resin and a particulate carbon material. And the composite material sheet manufactured using the manufacturing method of the composite material sheet of this invention is not specifically limited, It can use for various uses as a sheet-like member excellent in heat conductivity and electroconductivity.
Moreover, the composite material sheet produced by the method for producing a composite material sheet of the present invention can be used when producing a heat conductive sheet according to the method for producing a heat conductive sheet of the present invention. And the heat conductive sheet manufactured using the manufacturing method of the heat conductive sheet of this invention can be used by inserting | pinching between a heat generating body and a heat radiator when attaching a heat radiator to a heat generating body. That is, the heat conductive sheet manufactured using the manufacturing method of the heat conductive sheet of this invention can comprise a heat radiating device with heat sinks, such as a heat sink, a heat sink, and a heat radiating fin.
　なお、本発明の製造方法に従って製造した複合材料シートおよび熱伝導シートは、熱伝導性、強度、硬度、および導電性に優れている。従って、複合材料シートおよび熱伝導シートは、例えば、各種機器および装置などにおいて使用される放熱材料、放熱部品、冷却部品、温度調節部品、電磁シールド部品として好適である。ここで、各種機器および装置などとしては、特に限定されることなく、サーバー、サーバー用パソコン、デスクトップパソコン等の電子機器；ノートパソコン、電子辞書、ＰＤＡ、携帯電話、ポータブル音楽プレイヤー等の携帯電子機器；液晶ディスプレイ（バックライトを含む）、プラズマディスプレイ、ＬＥＤ、有機ＥＬ、無機ＥＬ、液晶プロジェクタ、時計等の表示機器；インクジェットプリンタ（インクヘッド）、電子写真装置（現像装置、定着装置、ヒートローラ、ヒートベルト）等の画像形成装置；半導体素子、半導体パッケージ、半導体封止ケース、半導体ダイボンディング、ＣＰＵ、メモリ、パワートランジスタ、パワートランジスタケース等の半導体関連部品；リジッド配線板、フレキシブル配線板、セラミック配線板、ビルドアップ配線板、多層基板等の配線基板（配線板にはプリント配線板なども含まれる）；真空処理装置、半導体製造装置、表示機器製造装置等の製造装置；断熱材、真空断熱材、輻射断熱材等の断熱装置；ＤＶＤ（光ピックアップ、レーザー発生装置、レーザー受光装置）、ハードディスクドライブ等のデータ記録機器；カメラ、ビデオカメラ、デジタルカメラ、デジタルビデオカメラ、顕微鏡、ＣＣＤ等の画像記録装置；充電装置、リチウムイオン電池、燃料電池等のバッテリー機器等が挙げられる。 In addition, the composite material sheet and the heat conductive sheet manufactured according to the manufacturing method of the present invention are excellent in heat conductivity, strength, hardness, and conductivity. Therefore, the composite material sheet and the heat conductive sheet are suitable as, for example, a heat radiating material, a heat radiating component, a cooling component, a temperature adjusting component, and an electromagnetic shielding component used in various devices and apparatuses. Here, various devices and devices are not particularly limited, and are electronic devices such as servers, server personal computers, and desktop personal computers; portable electronic devices such as notebook computers, electronic dictionaries, PDAs, mobile phones, and portable music players. Liquid crystal display (including backlight), plasma display, LED, organic EL, inorganic EL, liquid crystal projector, display device such as clock; ink jet printer (ink head), electrophotographic device (developing device, fixing device, heat roller, Image forming apparatuses such as heat belts; semiconductor-related components such as semiconductor elements, semiconductor packages, semiconductor encapsulating cases, semiconductor die bonding, CPUs, memories, power transistors, power transistor cases; rigid wiring boards, flexible wiring boards, ceramic wirings Board, Wiring board such as a folded-up wiring board and multilayer board (the wiring board includes a printed wiring board); manufacturing equipment such as vacuum processing equipment, semiconductor manufacturing equipment, display equipment manufacturing equipment; heat insulating material, vacuum heat insulating material, radiation heat insulating material Thermal insulation equipment for materials, etc .; DVD (optical pickup, laser generator, laser receiver), data recording equipment such as hard disk drive, etc .; Camera, video camera, digital camera, digital video camera, microscope, CCD, etc. image recording equipment; Examples thereof include battery devices such as devices, lithium ion batteries, and fuel cells.
（複合材料シートの製造方法）
　本発明の複合材料シートの製造方法では、樹脂と粒子状炭素材料とを含有する複合粒子を加圧してシート状に成形し、複合材料シートを製造する。ここで、本発明の複合材料シートの製造方法は、分級操作を経て得た所定の複合粒子を用いて加圧用複合粒子を準備する工程（加圧用複合粒子の準備工程）と、前記加圧用複合粒子を加圧する工程（加圧工程）とを含むことを特徴とする。そして、本発明の複合材料シートの製造方法では、所定の複合粒子を用いて準備した加圧用複合粒子に圧力を加えて複合材料シートを成形するので、高い熱伝導性、高い強度、および良好な硬度を並立させた複合材料シートが得られる。なお、加圧用複合粒子を用いることで熱伝導性、強度、および硬度に優れる複合材料シートが得られる理由は、明らかではないが、後に詳細に説明するように、加圧用複合粒子をシート状に加圧して得た複合材料シートでは、加圧時に粒子状炭素材料が良好に配向すると共に粒子状炭素材料同士の接触によって伝熱経路が良好に形成されるためであると推察される。
　以下、各工程について具体的に説明する。 (Production method of composite material sheet)
In the method for producing a composite material sheet of the present invention, composite particles containing a resin and a particulate carbon material are pressurized and formed into a sheet shape to produce a composite material sheet. Here, the manufacturing method of the composite material sheet of the present invention includes a step of preparing pressurizing composite particles using predetermined composite particles obtained through the classification operation (preparing step of pressurizing composite particles), and the pressurizing composite. And a step of pressurizing the particles (pressurizing step). And in the manufacturing method of the composite material sheet of the present invention, since the composite material sheet is molded by applying pressure to the composite particles for pressurization prepared using the predetermined composite particles, high thermal conductivity, high strength, and good A composite material sheet with parallel hardness is obtained. The reason why a composite material sheet having excellent thermal conductivity, strength, and hardness can be obtained by using the pressurizing composite particles is not clear, but as will be described in detail later, the pressurizing composite particles are formed into a sheet shape. In the composite material sheet obtained by pressurization, it is presumed that the particulate carbon material is well oriented during pressurization and the heat transfer path is well formed by contact between the particulate carbon materials.
Hereinafter, each step will be specifically described.
＜加圧用複合粒子の準備工程＞
　本発明の複合材料シートの製造方法に含まれる加圧用複合粒子の準備工程は、粒子状炭素材料および樹脂を含有する複合粒子を準備する工程（Ａ）と、得られた複合粒子を少なくとも２つの複合粒子群に分級する工程（Ｂ）と、分級により得られた複合粒子群のうちの所定の複合粒子群に含まれている複合粒子を用いて加圧用複合粒子を準備する工程（Ｃ）とを含む。そして、加圧用複合粒子の準備工程で準備された加圧用複合粒子は、加圧による複合材料シートの成形に用いられる。 <Preparation process of composite particles for pressurization>
The step of preparing composite particles for pressurization included in the method for producing a composite material sheet of the present invention includes a step (A) of preparing composite particles containing a particulate carbon material and a resin, and at least two of the obtained composite particles. Step (B) for classifying into composite particle groups, and Step (C) for preparing composite particles for pressurization using composite particles contained in a predetermined composite particle group among the composite particle groups obtained by classification including. The pressurizing composite particles prepared in the pressurizing composite particle preparation step are used for forming a composite material sheet by pressurization.
［工程（Ａ）］
　ここで、工程（Ａ）では、本発明の製造方法に従って複合材料シートを製造する際の材料（複合材料）として、粒子状炭素材料および樹脂を含有する複合粒子を準備する。 [Step (A)]
Here, in the step (A), composite particles containing a particulate carbon material and a resin are prepared as a material (composite material) when the composite material sheet is manufactured according to the manufacturing method of the present invention.
［［複合粒子］］
　工程（Ａ）で準備される複合粒子は、粒子状炭素材料および樹脂を含有する。また、工程（Ａ）で準備される複合粒子は、必要に応じて、繊維状炭素材料、および複合材料シートの成形に用いられる複合材料に一般に配合され得る既知の添加剤を含有することができる。 [[Composite particles]]
The composite particles prepared in the step (A) contain a particulate carbon material and a resin. Further, the composite particles prepared in the step (A) can contain a known additive that can be generally blended with the fibrous carbon material and the composite material used for molding the composite material sheet, if necessary. .
－粒子状炭素材料－
　ここで、複合粒子の粒子状炭素材料としては、特に限定されることなく、例えば、人造黒鉛、鱗片状黒鉛、薄片化黒鉛、天然黒鉛、酸処理黒鉛、膨張性黒鉛、膨張化黒鉛などの黒鉛；カーボンブラック；などを用いることができる。これらは、１種単独で使用してもよいし、２種以上を併用してもよい。中でも、粒子状炭素材料としては、膨張化黒鉛を用いることが好ましい。膨張化黒鉛を使用すれば、複合粒子を用いて製造した複合材料シートの熱伝導性を更に向上させることができるからである。 -Particulate carbon material-
Here, the particulate carbon material of the composite particles is not particularly limited. For example, graphite such as artificial graphite, scale-like graphite, exfoliated graphite, natural graphite, acid-treated graphite, expandable graphite, and expanded graphite. Carbon black; and the like can be used. These may be used individually by 1 type and may use 2 or more types together. Among them, it is preferable to use expanded graphite as the particulate carbon material. This is because if expanded graphite is used, the thermal conductivity of the composite material sheet produced using the composite particles can be further improved.
＝膨張化黒鉛＝
　ここで、粒子状炭素材料として好適に使用し得る膨張化黒鉛は、例えば、鱗片状黒鉛などの黒鉛を硫酸などで化学処理して得た膨張性黒鉛を、熱処理して膨張させた後、微細化することにより得ることができる。そして、膨張化黒鉛としては、例えば、伊藤黒鉛工業社製のＥＣ１５００、ＥＣ１０００、ＥＣ５００、ＥＣ３００、ＥＣ１００、ＥＣ５０（いずれも製品名）等が挙げられる。また、膨張化黒鉛としては鱗片状の膨張化黒鉛が好ましい。粒子状炭素材料として鱗片状の膨張化黒鉛を用いることにより、製造される複合材料シート内において粒子状炭素材料が更に良好に配向すると共に、各粒子状炭素材料同士の接触が容易になって、伝熱経路を形成し易いからである。 = Expanded graphite =
Here, the expanded graphite that can be suitably used as the particulate carbon material is, for example, finely expanded after heat-treating expandable graphite obtained by chemically treating graphite such as scaly graphite with sulfuric acid or the like. Can be obtained. Examples of expanded graphite include EC1500, EC1000, EC500, EC300, EC100, and EC50 (all are product names) manufactured by Ito Graphite Industries. Moreover, as expanded graphite, scaly expanded graphite is preferable. By using scale-like expanded graphite as the particulate carbon material, the particulate carbon material is more favorably oriented in the produced composite material sheet, and the contact between the particulate carbon materials is facilitated. This is because it is easy to form a heat transfer path.
＝粒子状炭素材料の性状＝
　ここで、複合粒子に含有されている粒子状炭素材料の粒子径は、特に限定されないが、体積換算のモード径で１５０μｍ以上であることが好ましく、５００μｍ以下であることが好ましく、３００μｍ以下であることがより好ましい。粒子状炭素材料の粒子径が上記下限以上であれば、粒子状炭素材料同士が良好に接触し、複合材料シートに高い熱伝導性を発揮させやすい。また、粒子状炭素材料の粒子径が上記上限以下であれば、共に複合される樹脂との接触面積が大きくなり、複合材料シートに良好な強度および硬度を発揮させやすい。
　また、本発明の複合粒子に含有されている粒子状炭素材料のアスペクト比（長径／短径）は、１以上１０以下であることが好ましく、１以上５以下であることがより好ましい。
　なお、本発明において「体積換算のモード径」は、レーザー回折／散乱式粒子径分布測定装置を用いて測定することができる。具体的には、粒子状炭素材料の「体積換算のモード径」は、粒子状炭素材料を溶媒に分散させた懸濁液を用いて得られた粒子径分布曲線の極大値における粒子径として求めることができる。
　また、本発明において、「アスペクト比」は、任意の５０個の粒子状炭素材料について、ＳＥＭ（走査型電子顕微鏡）を用いて最大径（長径）と、最大径に直交する方向の粒子径（短径）とを測定し、長径と短径の比（長径／短径）の平均値を算出することにより求めることができる。
　ここで、複合粒子中に含まれている粒子状炭素材料の「粒子径」および「アスペクト比」の測定は、例えば、複合粒子に含まれている樹脂に対する良溶媒を用いて樹脂を溶解させる等の任意の手法を用いて、複合粒子から粒子状炭素材料を取り出して行うことができる。 = Property of particulate carbon material =
Here, the particle diameter of the particulate carbon material contained in the composite particles is not particularly limited, but is preferably 150 μm or more, preferably 500 μm or less, and preferably 300 μm or less in volume conversion mode diameter. It is more preferable. When the particle diameter of the particulate carbon material is not less than the above lower limit, the particulate carbon materials are in good contact with each other, and the composite material sheet is likely to exhibit high thermal conductivity. Moreover, if the particle diameter of a particulate carbon material is below the said upper limit, a contact area with resin combined together will become large and it will be easy to make a composite material sheet exhibit favorable intensity | strength and hardness.
The aspect ratio (major axis / minor axis) of the particulate carbon material contained in the composite particles of the present invention is preferably 1 or more and 10 or less, and more preferably 1 or more and 5 or less.
In the present invention, the “mode diameter in terms of volume” can be measured using a laser diffraction / scattering particle size distribution measuring apparatus. Specifically, the “volume-converted mode diameter” of the particulate carbon material is obtained as the particle diameter at the maximum value of the particle diameter distribution curve obtained using a suspension in which the particulate carbon material is dispersed in a solvent. be able to.
Further, in the present invention, the “aspect ratio” refers to the maximum diameter (major axis) and the particle diameter (in the direction perpendicular to the maximum diameter) using an SEM (scanning electron microscope) for any 50 particulate carbon materials ( (Minor axis) is measured and the average value of the ratio of the major axis to the minor axis (major axis / minor axis) is calculated.
Here, the measurement of the “particle diameter” and the “aspect ratio” of the particulate carbon material contained in the composite particle is, for example, dissolving the resin using a good solvent for the resin contained in the composite particle, etc. The particulate carbon material can be taken out from the composite particles using any of the above methods.
＝粒子状炭素材料の含有量＝
　そして、複合粒子は、粒子状炭素材料の含有量（質量換算）が、樹脂に対して０．６倍以上であることが好ましく、２．０倍以下であることが好ましい。樹脂に対する粒子状炭素材料の含有量が０．６倍以上であれば、複合粒子を用いて製造した複合材料シートの熱伝導性を十分に高めることができる。また、樹脂に対する粒子状炭素材料の含有量が２．０倍以下であれば、複合材料シートに高い強度を与えつつシートを成形することができると共に、複合粒子を用いて製造した複合材料シートの硬度が上昇する（即ち、柔軟性が低下する）のを抑制することができる。 = Content of particulate carbon material =
And it is preferable that content (mass conversion) of a particulate carbon material is 0.6 times or more with respect to resin, and, as for composite particles, it is preferable that it is 2.0 times or less. When the content of the particulate carbon material relative to the resin is 0.6 times or more, the thermal conductivity of the composite material sheet manufactured using the composite particles can be sufficiently increased. Further, if the content of the particulate carbon material relative to the resin is 2.0 times or less, the sheet can be formed while giving high strength to the composite material sheet, and the composite material sheet produced using the composite particles It is possible to suppress an increase in hardness (that is, a decrease in flexibility).
－繊維状炭素材料－
　ここで、複合粒子は、上述の粒子状炭素材料に加えて繊維状炭素材料を更に含有することができる。繊維状炭素材料としては、特に限定されることなく、熱伝導性を有する任意の繊維状炭素材料を用いることができる。具体的には、繊維状炭素材料としては、例えば、気相成長炭素繊維、有機繊維を炭化して得られる炭素繊維、カーボンナノチューブ（以下、「ＣＮＴ」と称することがある。）等の円筒形状の炭素ナノ構造体、炭素の六員環ネットワークが扁平筒状に形成されてなる炭素材料等の非円筒形状の炭素ナノ構造体、およびそれらの切断物などを用いることができる。これらは、１種単独で使用してもよいし、２種以上を併用してもよい。 -Fibrous carbon material-
Here, the composite particles can further contain a fibrous carbon material in addition to the above-mentioned particulate carbon material. The fibrous carbon material is not particularly limited, and any fibrous carbon material having thermal conductivity can be used. Specifically, examples of the fibrous carbon material include cylindrical shapes such as vapor-grown carbon fiber, carbon fiber obtained by carbonizing organic fiber, and carbon nanotube (hereinafter sometimes referred to as “CNT”). Carbon nanostructures, non-cylindrical carbon nanostructures such as carbon materials in which a carbon six-membered ring network is formed in a flat cylindrical shape, and their cuts can be used. These may be used individually by 1 type and may use 2 or more types together.
　中でも、粒子状炭素材料と併用される繊維状炭素材料としては、更に良好な伝熱経路を形成して複合材料シートの熱伝導性を更に向上させ得る観点からは、ＣＮＴを含む繊維状炭素材料を用いることが好ましい。また、ＣＮＴとしては、特に限定されることなく、単層カーボンナノチューブおよび／または多層カーボンナノチューブを用いることができるが、複合材料シートの熱伝導性を更に向上させ得る観点からは、ＣＮＴは、単層カーボンナノチューブを主に含むことがより好ましく、単層カーボンナノチューブのみであることが更に好ましい。
　なお、本発明において、単層カーボンナノチューブを「主に含む」とは、単層カーボンナノチューブの含有割合が９０質量％以上であることを指す。 Among them, as the fibrous carbon material used in combination with the particulate carbon material, a fibrous carbon material containing CNT is used from the viewpoint of further improving the thermal conductivity of the composite material sheet by forming a better heat transfer path. Is preferably used. The CNT is not particularly limited, and single-walled carbon nanotubes and / or multi-walled carbon nanotubes can be used. From the viewpoint of further improving the thermal conductivity of the composite material sheet, More preferably, it mainly contains single-walled carbon nanotubes, and more preferably only single-walled carbon nanotubes.
In the present invention, “mainly containing” single-walled carbon nanotubes means that the content of single-walled carbon nanotubes is 90% by mass or more.
＝繊維状炭素材料の作製方法＝
　なお、ＣＮＴを含む繊維状炭素材料は、特に限定されることなく、アーク放電法、レーザーアブレーション法、または、スーパーグロース法（国際公開第２００６／０１１６５５号参照）を含む化学的気相成長法（ＣＶＤ法）などの既知のＣＮＴの合成方法を用いて製造することができる。なお、以下では、スーパーグロース法により得られるカーボンナノチューブを「ＳＧＣＮＴ」と称することがある。 = Method for producing fibrous carbon material =
The fibrous carbon material containing CNT is not particularly limited, and is a chemical vapor deposition method including an arc discharge method, a laser ablation method, or a super-growth method (see International Publication No. 2006/011655) ( It can be produced using a known CNT synthesis method such as a CVD method. Hereinafter, the carbon nanotube obtained by the super growth method may be referred to as “SGCNT”.
＝繊維状炭素材料の性状＝
　ここで、繊維状炭素材料の平均直径は、０．５ｎｍ以上であることが好ましく、１５ｎｍ以下であることが好ましい。繊維状炭素材料の平均直径が０．５ｎｍ以上であれば、繊維状炭素材料の凝集を抑制して、複合材料シートの熱伝導性を更に向上させることができる。また、繊維状炭素材料の平均直径が１５ｎｍ以下であれば、繊維状炭素材料に優れた熱伝導性を発揮させ、複合材料シートの熱伝導性を更に高めることができる。 = Property of fibrous carbon material =
Here, the average diameter of the fibrous carbon material is preferably 0.5 nm or more, and preferably 15 nm or less. If the average diameter of the fibrous carbon material is 0.5 nm or more, aggregation of the fibrous carbon material can be suppressed and the thermal conductivity of the composite material sheet can be further improved. Moreover, if the average diameter of a fibrous carbon material is 15 nm or less, the thermal conductivity which was excellent in the fibrous carbon material can be exhibited, and the thermal conductivity of a composite material sheet can further be improved.
　また、繊維状炭素材料は、合成時における平均長さが、１μｍ以上であることが好ましい。合成時の繊維状炭素材料の平均長さが１μｍ以上であれば、複合材料シート中において伝熱経路を良好に形成することができる。また、合成時の繊維状炭素材料の長さが長いほど、複合粒子を準備する過程で繊維状炭素材料に破断や切断などの損傷が発生し易いので、合成時の繊維状炭素材料の平均長さは５０００μｍ以下であることが好ましい。
　なお、繊維状炭素材料は、通常、アスペクト比が１０超である。 Further, the fibrous carbon material preferably has an average length of 1 μm or more at the time of synthesis. If the average length of the fibrous carbon material at the time of synthesis is 1 μm or more, the heat transfer path can be satisfactorily formed in the composite material sheet. In addition, the longer the fibrous carbon material during synthesis, the easier it is to cause damage such as breakage and cutting in the process of preparing composite particles, so the average length of the fibrous carbon material during synthesis The thickness is preferably 5000 μm or less.
The fibrous carbon material usually has an aspect ratio of more than 10.
　また、熱伝導性に優れる複合材料シートを得る観点からは、繊維状炭素材料は、ＢＥＴ比表面積が、２００ｍ２／ｇ以上であることが好ましく、２５００ｍ２／ｇ以下であることが好ましい。繊維状炭素材料のＢＥＴ比表面積が２００ｍ２／ｇ以上であれば、繊維状炭素材料に優れた熱伝導性を発揮させ、複合材料シートの熱伝導性を十分に高めることができる。また、繊維状炭素材料のＢＥＴ比表面積が２５００ｍ２／ｇ以下であれば、繊維状炭素材料の凝集を抑制して、複合材料シートの熱伝導性を更に向上させることができる。 From the viewpoint of obtaining a composite material sheet having excellent thermal conductivity, the fibrous carbon material preferably has a BET specific surface area of 200 m 2 / g or more, and preferably 2500 m 2 / g or less. If the BET specific surface area of a fibrous carbon material is 200 m < 2 > / g or more, the thermal conductivity which was excellent in the fibrous carbon material can be exhibited, and the thermal conductivity of a composite material sheet can fully be improved. Moreover, if the BET specific surface area of a fibrous carbon material is 2500 m < 2 > / g or less, aggregation of a fibrous carbon material can be suppressed and the thermal conductivity of a composite material sheet can further be improved.
　ここで、本発明において、繊維状炭素材料の「平均直径」、「アスペクト比」および「平均長さ」は、ＴＥＭ（透過型電子顕微鏡）またはＳＥＭ（走査型電子顕微鏡）等の顕微鏡を用いて、無作為に選択した繊維状炭素材料１００本の直径（外径）および長さを測定して求めることができる。また、本発明において、繊維状炭素材料の「ＢＥＴ比表面積」とは、ＢＥＴ法を用いて測定した窒素吸着比表面積を指す。 Here, in the present invention, the “average diameter”, “aspect ratio”, and “average length” of the fibrous carbon material are measured using a microscope such as TEM (transmission electron microscope) or SEM (scanning electron microscope). It can be obtained by measuring the diameter (outer diameter) and length of 100 randomly selected fibrous carbon materials. In the present invention, the “BET specific surface area” of the fibrous carbon material refers to a nitrogen adsorption specific surface area measured using the BET method.
＝繊維状炭素材料の配合量＝
　そして、複合粒子中の繊維状炭素材料の含有量は、樹脂１００質量部当たり、０．０５質量部以上とすることができ、５．０質量部以下とすることができる。樹脂１００質量部当たりの繊維状炭素材料の含有量が０．０５質量部以上であれば、複合材料シートの熱伝導性を十分に高めることができる。また、樹脂１００質量部当たりの繊維状炭素材料の含有量が５．０質量部以下であれば、繊維状炭素材料の配合により複合材料シートの硬度が上昇する（即ち、柔軟性が低下する）のを十分に抑制しつつ複合材料シートを良好に成形することができる。 = Blending amount of fibrous carbon material =
And content of the fibrous carbon material in a composite particle can be 0.05 mass part or more per 100 mass parts of resin, and can be 5.0 mass parts or less. When the content of the fibrous carbon material per 100 parts by mass of the resin is 0.05 parts by mass or more, the thermal conductivity of the composite material sheet can be sufficiently increased. Further, if the content of the fibrous carbon material per 100 parts by mass of the resin is 5.0 parts by mass or less, the hardness of the composite material sheet is increased by mixing the fibrous carbon material (that is, the flexibility is decreased). It is possible to satisfactorily mold the composite material sheet while sufficiently suppressing the above.
－樹脂－
　複合粒子に含まれる樹脂としては、特に限定されることなく、複合材料シートの製造に使用され得る既知の樹脂を用いることができる。具体的には、樹脂としては、熱可塑性樹脂または熱硬化性樹脂を用いることができる。なお、本発明において、ゴムおよびエラストマーは、「樹脂」に含まれるものとする。また、熱可塑性樹脂と熱硬化性樹脂とは併用してもよい。 -resin-
The resin contained in the composite particle is not particularly limited, and a known resin that can be used for manufacturing a composite material sheet can be used. Specifically, a thermoplastic resin or a thermosetting resin can be used as the resin. In the present invention, rubber and elastomer are included in “resin”. Moreover, you may use together a thermoplastic resin and a thermosetting resin.
＝熱可塑性樹脂＝
　なお、熱可塑性樹脂としては、例えば、ポリ（アクリル酸２－エチルヘキシル）、アクリル酸とアクリル酸２－エチルヘキシルとの共重合体、ポリメタクリル酸またはそのエステル、ポリアクリル酸またはそのエステルなどのアクリル樹脂；シリコーン樹脂；ポリフッ化ビニリデン、ポリテトラフルオロエチレン、ポリテトラフルオロエチレンのアクリル変性物、テトラフルオロエチレン－パーフルオロアルキルビニルエーテル共重合体、ビニリデンフルオライド－テトラフルオロエチレン－ヘキサフルオロプロピレン共重合体などのフッ素樹脂；ポリエチレン；ポリプロピレン；エチレン－プロピレン共重合体；ポリメチルペンテン；ポリ塩化ビニル；ポリ塩化ビニリデン；ポリ酢酸ビニル；エチレン－酢酸ビニル共重合体；ポリビニルアルコール；ポリアセタール；ポリエチレンテレフタレート；ポリブチレンテレフタレート；ポリエチレンナフタレート；ポリスチレン；ポリアクリロニトリル；スチレン－アクリロニトリル共重合体；アクリロニトリル－ブタジエン－スチレン共重合体（ＡＢＳ樹脂）；スチレン－ブタジエンブロック共重合体またはその水素添加物；スチレン－イソプレンブロック共重合体またはその水素添加物；ポリフェニレンエーテル；変性ポリフェニレンエーテル；脂肪族ポリアミド類；芳香族ポリアミド類；ポリアミドイミド；ポリカーボネート；ポリフェニレンスルフィド；ポリサルホン；ポリエーテルサルホン；ポリエーテルニトリル；ポリエーテルケトン；ポリケトン；ポリウレタン；液晶ポリマー；アイオノマー；などが挙げられる。これらは、１種単独で使用してもよいし、２種以上を併用してもよい。 = Thermoplastic resin =
Examples of the thermoplastic resin include poly (2-ethylhexyl acrylate), a copolymer of acrylic acid and 2-ethylhexyl acrylate, polymethacrylic acid or an ester thereof, and an acrylic resin such as polyacrylic acid or an ester thereof. Silicone resin; polyvinylidene fluoride, polytetrafluoroethylene, acrylic modified polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, etc. Fluorine resin; Polyethylene; Polypropylene; Ethylene-propylene copolymer; Polymethylpentene; Polyvinyl chloride; Polyvinylidene chloride; Polyvinyl acetate; Ethylene-vinyl acetate copolymer; Polyacetal; Polyethylene terephthalate; Polybutylene terephthalate; Polyethylene naphthalate; Polystyrene; Polyacrylonitrile; Styrene-acrylonitrile copolymer; Acrylonitrile-butadiene-styrene copolymer (ABS resin); Styrene-butadiene block copolymer or its hydrogen Additives; Styrene-isoprene block copolymer or hydrogenated product thereof; Polyphenylene ether; Modified polyphenylene ether; Aliphatic polyamides; Aromatic polyamides; Polyamideimide; Polycarbonate; Polyphenylene sulfide; Polysulfone; Nitrile; polyetherketone; polyketone; polyurethane; liquid crystal polymer; ionomer; These may be used individually by 1 type and may use 2 or more types together.
＝熱硬化性樹脂＝
　また、熱硬化性樹脂としては、例えば、天然ゴム；ブタジエンゴム；イソプレンゴム；ニトリルゴム；水素化ニトリルゴム；クロロプレンゴム；エチレンプロピレンゴム；塩素化ポリエチレン；クロロスルホン化ポリエチレン；ブチルゴム；ハロゲン化ブチルゴム；ポリイソブチレンゴム；エポキシ樹脂；ポリイミド樹脂；ビスマレイミド樹脂；ベンゾシクロブテン樹脂；フェノール樹脂；不飽和ポリエステル；ジアリルフタレート樹脂；ポリイミドシリコーン樹脂；ポリウレタン；熱硬化型ポリフェニレンエーテル；熱硬化型変性ポリフェニレンエーテル；などが挙げられる。これらは、１種単独で使用してもよいし、２種以上を併用してもよい。 = Thermosetting resin =
Examples of the thermosetting resin include natural rubber, butadiene rubber, isoprene rubber, nitrile rubber, hydrogenated nitrile rubber, chloroprene rubber, ethylene propylene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, butyl rubber, and halogenated butyl rubber. Polyisobutylene rubber; Epoxy resin; Polyimide resin; Bismaleimide resin; Benzocyclobutene resin; Phenolic resin; Unsaturated polyester; Diallyl phthalate resin; Polyimide silicone resin; Polyurethane; Thermosetting polyphenylene ether; Is mentioned. These may be used individually by 1 type and may use 2 or more types together.
　上述した中でも、複合粒子の樹脂としては、熱可塑性樹脂を用いることが好ましく、フッ素樹脂を用いることがより好ましく、異なる単量体からなる二元系フッ素樹脂または三元系フッ素樹脂を用いることがより好ましい。そして、例えば三元系フッ素樹脂としては、ビニリデンフルオライド－テトラフルオロエチレン－ヘキサフルオロプロピレン共重合体を用いることができる。上記フッ素樹脂は機械的性質等に優れており、また、フッ素樹脂などの熱可塑性樹脂を用いれば、複合材料シートの強度や硬度（柔軟性）を更に向上させることができるからである。 Among the above, as the resin of the composite particles, it is preferable to use a thermoplastic resin, more preferably a fluororesin, and a binary fluororesin or a ternary fluororesin composed of different monomers. More preferred. For example, as the ternary fluororesin, a vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer can be used. This is because the fluororesin is excellent in mechanical properties and the like, and if a thermoplastic resin such as a fluororesin is used, the strength and hardness (flexibility) of the composite material sheet can be further improved.
＝樹脂の含有量＝
　ここで、複合粒子に含まれる樹脂の含有量は任意の配合量とすることができる。例えば、粒子状炭素材料などと樹脂とを良好に複合させる観点からは、複合粒子に含まれる樹脂は、複合粒子に含まれる粒子状炭素材料１００質量部に対して５０質量部以上が好ましく、５５質量部以上がより好ましく、１５０質量部以下が好ましく、１００質量部以下がより好ましく、７０質量部以下が更に好ましい。粒子状炭素材料１００質量部当たりの樹脂の含有量が１５０質量部以下であれば、複合材料シートの熱伝導性を十分に高めることができる。また、粒子状炭素材料１００質量部当たりの樹脂の含有量が５０質量部以上であれば、複合材料シートに高い強度を与えつつシートを成形することができると共に、複合材料シートの硬度が上昇する（即ち、柔軟性が低下する）のを十分に抑制することができる。 = Resin content =
Here, the content of the resin contained in the composite particles can be any blending amount. For example, from the viewpoint of satisfactorily combining the particulate carbon material and the resin with the resin, the resin contained in the composite particle is preferably 50 parts by mass or more with respect to 100 parts by mass of the particulate carbon material contained in the composite particle. More than mass part is more preferable, 150 mass parts or less are preferable, 100 mass parts or less are more preferable, and 70 mass parts or less are still more preferable. If the content of the resin per 100 parts by mass of the particulate carbon material is 150 parts by mass or less, the thermal conductivity of the composite material sheet can be sufficiently increased. Further, if the content of the resin per 100 parts by mass of the particulate carbon material is 50 parts by mass or more, the sheet can be molded while giving high strength to the composite material sheet, and the hardness of the composite material sheet increases. (That is, flexibility is reduced) can be sufficiently suppressed.
－添加剤－
　複合粒子に任意に配合し得る添加剤としては、特に限定されることなく、例えば、赤リン系難燃剤、リン酸エステル系難燃剤などの難燃剤；セバシン酸などの可塑剤；酸化カルシウム、酸化マグネシウムなどの吸湿剤；シランカップリング剤、チタンカップリング剤、酸無水物などの接着力向上剤；ノニオン系界面活性剤、フッ素系界面活性剤などの濡れ性向上剤；無機イオン交換体などのイオントラップ剤；等が挙げられる。中でも、リン酸エステルなどのリン酸エステル系難燃剤を添加することが好ましい。 -Additive-
Additives that can be optionally blended in the composite particles are not particularly limited, and include, for example, red phosphorus flame retardants, phosphate ester flame retardants, and the like; sebacic acid and other plasticizers; calcium oxide, oxidation Hygroscopic agents such as magnesium; Adhesive strength improvers such as silane coupling agents, titanium coupling agents, acid anhydrides; wettability improvers such as nonionic surfactants and fluorosurfactants; inorganic ion exchangers, etc. Ion trapping agents; and the like. Among these, it is preferable to add a phosphate ester flame retardant such as a phosphate ester.
－複合粒子の準備方法－
　そして、工程（Ａ）では、既知の手法を用いて、上述の粒子状炭素材料と、樹脂と、任意に繊維状炭素材料および添加剤とを複合化することにより、複合粒子を得ることができる。具体的には、工程（Ａ）では、特に限定されることなく、例えば以下の（Ｉ）または（ＩＩ）の方法を用いて複合粒子を準備することができる。
（Ｉ）粒子状炭素材料と、樹脂と、任意の繊維状炭素材料および添加剤とを混練した後（混練段階）、得られた混練物を粉砕して（粉砕段階）複合粒子を得る。
（ＩＩ）粒子状炭素材料と、樹脂と、任意の繊維状炭素材料および添加剤とを含む分散液を乾燥造粒して複合粒子を得る。
　中でも、粒子状炭素材料および樹脂を良好に複合化させる観点、および作業の容易性の観点から、（Ｉ）の方法が望ましい。 -Preparation method of composite particles-
And in a process (A), a composite particle can be obtained by compounding the above-mentioned particulate carbon material, resin, and optionally a fibrous carbon material and an additive using a known technique. . Specifically, in the step (A), the composite particles can be prepared using, for example, the following method (I) or (II) without any particular limitation.
(I) After kneading a particulate carbon material, a resin, an arbitrary fibrous carbon material and an additive (kneading stage), the obtained kneaded product is pulverized (pulverizing stage) to obtain composite particles.
(II) A dispersion containing a particulate carbon material, a resin, an arbitrary fibrous carbon material and an additive is dried and granulated to obtain composite particles.
Among these, the method (I) is desirable from the viewpoint of satisfactorily combining the particulate carbon material and the resin and from the viewpoint of ease of work.
＝混練段階＝
　工程（Ａ）に含まれ得る混練段階では、粒子状炭素材料と、樹脂と、任意の繊維状炭素材料および添加剤とを混錬し、粒子状炭素材料および樹脂を含有し、任意に繊維状炭素材料および添加剤を更に含有する混練物を得る。 = Kneading stage =
In the kneading stage that can be included in the step (A), the particulate carbon material, the resin, the arbitrary fibrous carbon material and the additive are kneaded, the particulate carbon material and the resin are contained, and optionally the fibrous shape A kneaded material further containing a carbon material and an additive is obtained.
　ここで、混練段階で得られる混練物は、通常、直径１ｍｍ～２００ｍｍ程度の塊状体である。
　なお、混練段階で得られる混練物に含有される「粒子状炭素材料」、「樹脂」、並びに、任意の「繊維状炭素材料」および「添加剤」は、上述した複合粒子に含有され得る「粒子状炭素材料」、「樹脂」、「繊維状炭素材料」および「添加剤」と同様のものであり、その種類、性状、配合量、作製方法等も同様であるので、以下では説明を省略する。 Here, the kneaded product obtained in the kneading step is usually a lump having a diameter of about 1 mm to 200 mm.
The “particulate carbon material”, “resin”, and any “fibrous carbon material” and “additive” contained in the kneaded product obtained in the kneading stage can be contained in the composite particles described above. Since it is the same as the “particulate carbon material”, “resin”, “fibrous carbon material” and “additive”, the type, properties, blending amount, production method, etc. are also the same, so the description is omitted below. To do.
　ここで、混練方法は、特に限定されることなく、ニーダー；ホバートミキサー、バンバリーミキサー、ハイスピードミキサーなどのミキサー；二軸混練機；ロール；等の既知の混練装置を用いた方法とすることができる。そして、混練時間は、例えば５分以上６０分以下とすることができる。また、混練温度は、例えば５℃以上１５０℃以下とすることができる。
　なお、混練は、酢酸エチル等の溶媒の存在下で行ってもよく、混練時に溶媒を用いる場合には、溶媒を除去してから後述する粉砕段階へと移行することが好ましい。溶媒の除去は既知の乾燥方法にて行える。 Here, the kneading method is not particularly limited, and a kneader; a mixer such as a Hobart mixer, a Banbury mixer, a high-speed mixer; a twin-screw kneader; a roll; it can. And kneading | mixing time can be made into 5 minutes or more and 60 minutes or less, for example. Moreover, kneading | mixing temperature can be 5 degreeC or more and 150 degrees C or less, for example.
The kneading may be performed in the presence of a solvent such as ethyl acetate. When a solvent is used at the time of kneading, it is preferable to move to the pulverization stage described below after removing the solvent. The solvent can be removed by a known drying method.
＝粉砕段階＝
　工程（Ａ）に含まれ得る粉砕段階では、例えば、上述の混練段階で得られた混練物を任意の手法で適度に粉砕することにより、粒子状炭素材料および樹脂を含有する複合粒子を得る。 = Grinding stage =
In the pulverization stage that can be included in the step (A), for example, the kneaded product obtained in the above-described kneading stage is appropriately pulverized by an arbitrary technique to obtain composite particles containing the particulate carbon material and the resin.
　ここで、粉砕段階で得られる複合粒子は、特に制限されることなく、１０００μｍ未満の粒子径にまで粉砕されていることが好ましい。 Here, the composite particles obtained in the pulverization stage are not particularly limited and are preferably pulverized to a particle diameter of less than 1000 μm.
　ここで、粉砕方法は、特に限定されることなく、せん断作用や摩砕作用を利用した既知の粉砕装置または撹拌式の既知の粉砕装置等を用いて行うことができる。せん断作用や摩砕作用を利用した、または攪拌式の既知の粉砕装置としては、例えば、カッターミル、ハンマーミル、ビーズミル、振動ミル、流星型ボールミル、サンドミル、ボールミル、ロールミル、三本ロールミル、ジェットミル、高速回転式粉砕機等を挙げることができる。中でも、カッターミルまたはハンマーミルを用いることが望ましい。
　また、粉砕条件は、所望の粉砕粒子径に合わせて粉砕装置、粉砕時間などを適宜調整すればよい。例えば、カッターミルを用いる場合は、粉砕時間は１０秒以上６０秒以下であることが好ましく、ハンマーミルを用いる場合は、粉砕時間は５秒以上３０秒以下であることが好ましい。 Here, the pulverization method is not particularly limited, and can be performed using a known pulverization apparatus utilizing a shearing action or a grinding action or a known stirring pulverization apparatus. Examples of known crushing devices using shearing action or grinding action or stirring type include, for example, a cutter mill, a hammer mill, a bead mill, a vibration mill, a meteor type ball mill, a sand mill, a ball mill, a roll mill, a three-roll mill, and a jet mill. And a high-speed rotary crusher. Among these, it is desirable to use a cutter mill or a hammer mill.
The pulverization conditions may be adjusted as appropriate according to the desired pulverized particle size, such as the pulverization apparatus and pulverization time. For example, when using a cutter mill, the pulverization time is preferably from 10 seconds to 60 seconds, and when using a hammer mill, the pulverization time is preferably from 5 seconds to 30 seconds.
［工程（Ｂ）］
　工程（Ｂ）では、工程（Ａ）で準備された複合粒子を、最大体積平均粒子径を有する複合粒子群Ａおよび最小体積平均粒子径を有する複合粒子群Ｂを含む、少なくとも２つの複合粒子群に分級する。つまり、工程（Ｂ）では、最大体積平均粒子径を有する複合粒子群Ａおよび最小体積平均粒子径を有する複合粒子群Ｂのみを得てもよい。また、工程（Ｂ）では、最大体積平均粒子径を有する複合粒子群Ａと、最小体積平均粒子径を有する複合粒子群Ｂと、当該最大体積平均粒子径および当該最小体積平均粒子径の間の体積平均粒子径を有する任意のその他の複合粒子群とを得てもよい。ここで、当該その他の複合粒子群は一つであっても複数であってもよい。
　なお、複合粒子群の数および各複合粒子群の体積平均粒子径は、工程（Ｂ）における複合粒子の分級方法および分級条件を変更することにより調整することができる。 [Step (B)]
In the step (B), the composite particles prepared in the step (A) include at least two composite particle groups including the composite particle group A having the maximum volume average particle size and the composite particle group B having the minimum volume average particle size. Classify. That is, in the step (B), only the composite particle group A having the maximum volume average particle diameter and the composite particle group B having the minimum volume average particle diameter may be obtained. In the step (B), the composite particle group A having the maximum volume average particle diameter, the composite particle group B having the minimum volume average particle diameter, and the maximum volume average particle diameter and the minimum volume average particle diameter Any other composite particle group having a volume average particle diameter may be obtained. Here, the other composite particle group may be one or plural.
The number of composite particle groups and the volume average particle diameter of each composite particle group can be adjusted by changing the classification method and classification conditions of the composite particles in the step (B).
［［複合粒子群Ａおよび複合粒子群Ｂ］］
　工程（Ｂ）で得られる複合粒子群Ａは最大体積平均粒子径を有することが必要であり、工程（Ｂ）で得られる複合粒子群Ｂは最小体積平均粒子径を有することが必要である。例えば、ふるいを用いて複合粒子を分級した場合は、目開きが最も大きいふるいのふるい上が複合粒子群Ａとなり、目開きが最も小さいふるいのふるい下が複合粒子群Ｂとなる。
　ここで、「最大／最小体積平均粒子径」とは、複合粒子の分級により得られる少なくとも２つの複合粒子群の各複合粒子群について測定した、各体積平均粒子径の中での最大／最小を指し、相対的な概念である。 [[Composite Particle Group A and Composite Particle Group B]]
The composite particle group A obtained in the step (B) needs to have a maximum volume average particle size, and the composite particle group B obtained in the step (B) needs to have a minimum volume average particle size. For example, when the composite particles are classified using a sieve, the top of the sieve having the largest opening is the composite particle group A, and the bottom of the sieve having the smallest opening is the composite particle group B.
Here, the “maximum / minimum volume average particle diameter” means the maximum / minimum of the volume average particle diameters measured for each composite particle group of at least two composite particle groups obtained by classifying the composite particles. Pointing is a relative concept.
　つまり、例えば、分級により得られた複合粒子群が２つであり、且つ各体積平均粒子径がαμｍおよびβμｍ（ここで、αμｍ＜βμｍである。）であれば、体積平均粒子径がβμｍである複合粒子群が複合粒子群Ａとなり、体積平均粒子径がαμｍである複合粒子群が複合粒子群Ｂとなる。具体的には、分級により得られた２つの複合粒子群の体積平均粒子径がそれぞれ１００μｍおよび８００μｍであれば、体積平均粒子径が８００μｍである複合粒子群が複合粒子群Ａとなり、体積平均粒子径が１００μｍである複合粒子群が複合粒子群Ｂとなる＜群１＞。また、例えば、得られた複合粒子群が３つであり、且つ各体積平均粒子径が２００μｍ、４００μｍ、および８００μｍであれば、体積平均粒子径が８００μｍである複合粒子群が複合粒子群Ａとなり、体積平均粒子径が２００μｍである複合粒子群が複合粒子群Ｂとなる＜群２＞。さらに、例えば、得られた複合粒子群が４つであり、且つ各体積平均粒子径が２００μｍ、４００μｍ、８００μｍ、および１０００μｍであれば、体積平均粒子径が１０００μｍである複合粒子群が複合粒子群Ａとなり、体積平均粒子径が２００μｍである複合粒子群が複合粒子群Ｂとなる＜群３＞。このように、複合粒子群Ａおよび複合粒子Ｂが有する体積平均粒子径は、分級される粒子径範囲によって異なる。
　なお、複合粒子群の「体積平均粒子径」とは、上述のＤ５０を指し、上述のレーザー回折／散乱式粒子径分布測定装置を用いて測定することができる。 That is, for example, if there are two composite particle groups obtained by classification and the respective volume average particle diameters are α μm and β μm (where αμm <β μm), the volume average particle diameter is β μm. A certain composite particle group becomes the composite particle group A, and a composite particle group whose volume average particle diameter is α μm becomes the composite particle group B. Specifically, if the volume average particle diameters of the two composite particle groups obtained by classification are 100 μm and 800 μm, respectively, the composite particle group having a volume average particle diameter of 800 μm becomes the composite particle group A, and the volume average particle A composite particle group having a diameter of 100 μm becomes a composite particle group B <Group 1>. Further, for example, when the obtained composite particle group is three and each volume average particle diameter is 200 μm, 400 μm, and 800 μm, the composite particle group having a volume average particle diameter of 800 μm becomes the composite particle group A. The composite particle group having a volume average particle diameter of 200 μm becomes the composite particle group B <Group 2>. Furthermore, for example, when the obtained composite particle groups are four and each volume average particle diameter is 200 μm, 400 μm, 800 μm, and 1000 μm, the composite particle group having a volume average particle diameter of 1000 μm is the composite particle group A composite particle group having a volume average particle diameter of 200 μm and A is a composite particle group B <Group 3>. Thus, the volume average particle size of the composite particle group A and the composite particle B varies depending on the particle size range to be classified.
The “volume average particle diameter” of the composite particle group refers to the above-described D50, and can be measured using the above-described laser diffraction / scattering particle diameter distribution measuring apparatus.
［［その他の複合粒子群］］
　工程（Ｂ）で得られ得るその他の複合粒子群は、最大体積平均粒子径および最小体積平均粒子径の間の体積平均粒子径を有する任意の数の複合粒子群である。
　つまり、上述の＜群１＞ではその他の複合粒子群は存在せず、上述の＜群２＞では体積平均粒子径が４００μｍである複合粒子群がその他の複合粒子群となる。また、上述の＜群３＞では、体積平均粒子径が４００μｍおよび８００μｍである２つの複合粒子群がそれぞれその他の複合粒子群となる。 [[Other complex particles]]
Other composite particle groups that can be obtained in the step (B) are any number of composite particle groups having a volume average particle diameter between the maximum volume average particle diameter and the minimum volume average particle diameter.
That is, in the above <Group 1>, no other composite particle group exists, and in the above <Group 2>, the composite particle group having a volume average particle diameter of 400 μm becomes the other composite particle group. In the above <Group 3>, the two composite particle groups having a volume average particle diameter of 400 μm and 800 μm are the other composite particle groups, respectively.
－分級の方法－
　ここで、分級は、得られた複合粒子の分離が可能であれば特に限定されることなく、例えば、ふるい分法、強制渦流型遠心分級機（ミクロンセパレーター、ターボプレックス、ターボクラシファイアー、スーパーセパレーター）、慣性分級機（改良型バーチュウアルインパクター、エルボジェット）等の気流分級機が使用できる。また湿式の沈降分離法や遠心分級法等も使用可能である。中でも、作業の簡便性の観点より、所望の目開きを有するふるい分法が好ましく、当該ふるい分法は手作業で行うことがより好ましい。
　なお、良好な加圧用複合粒子を得る観点からは、ふるいを用いて複合粒子を分級する場合には、ふるいの目開きが５００μｍ以下のふるいを一つ以上用いて分級することが好ましく、ふるいの目開きが２５０μｍ以下のふるいを一つ以上用いて分級することがより好ましく、また、使用するふるいの目開きは１５０μｍ以上であることが好ましい。
　ここで、分級温度は、特に制限なく、例えば２５℃下で行うことができる。 -Classification method-
Here, the classification is not particularly limited as long as the obtained composite particles can be separated. For example, sieve classification, forced vortex type centrifugal classifier (micron separator, turboplex, turbo classifier, super separator) ), An air classifier such as an inertia classifier (an improved virtual impactor, elbow jet) can be used. A wet sedimentation method, a centrifugal classification method, or the like can also be used. Among these, from the viewpoint of easy work, a sieving method having a desired mesh opening is preferable, and the sieving method is more preferably performed manually.
From the viewpoint of obtaining a good composite particle for pressurization, when classifying the composite particles using a sieve, it is preferable to classify using one or more sieves having a sieve opening of 500 μm or less. It is more preferable to classify using one or more sieves having an opening of 250 μm or less, and the opening of the sieve to be used is preferably 150 μm or more.
Here, the classification temperature is not particularly limited, and can be performed, for example, at 25 ° C.
［工程（Ｃ）］
　工程（Ｃ）では、工程（Ｂ）で得られた複合粒子群のうち、複合粒子群Ａ以外の複合粒子群に含まれている複合粒子を用いることにより、加圧用複合粒子を準備する。 [Step (C)]
In the step (C), the composite particles for pressurization are prepared by using the composite particles contained in the composite particle groups other than the composite particle group A among the composite particle groups obtained in the step (B).
　ここで、「複合粒子群Ａ以外の複合粒子群に含まれている複合粒子を用いる」とは、例えば、上述の＜群１＞では、分級により得られた複合粒子群Ｂに含まれている複合粒子のみを用いて（つまり、複合粒子群Ａを工程（Ａ）で得た複合粒子全体から取り除いて）加圧用複合粒子を準備することを指す。 Here, “use composite particles contained in a composite particle group other than the composite particle group A” is included in the composite particle group B obtained by classification in the above <Group 1>, for example. This refers to preparing composite particles for pressurization using only composite particles (that is, removing composite particle group A from the entire composite particles obtained in step (A)).
　また、例えば、上述の＜群２＞では、複合粒子群Ｂおよびその他の複合粒子群に含まれている複合粒子の少なくとも一方を用いて（つまり、少なくとも、複合粒子群Ａを工程（Ａ）で得た複合粒子全体から取り除いて）加圧用複合粒子を準備する。即ち、上述の＜群２＞では、複合粒子群Ｂおよびその他の複合粒子群に含まれている複合粒子を用いて加圧用複合粒子を準備してもよいし、複合粒子群Ｂに含まれている複合粒子のみを用いて加圧用複合粒子を準備してもよいし、その他の複合粒子群に含まれている複合粒子のみを用いて加圧用複合粒子を準備してもよい。
　このように、工程（Ｃ）では、加圧用複合粒子の準備に用いられる複合粒子群から、少なくとも複合粒子群Ａを除去することを必要とする。また、工程（Ｃ）は、加圧用複合粒子の準備に用いられる複合粒子群から、複合粒子群Ａ以外の複合粒子群（複合粒子群Ｂおよび／またはその他の複合粒子群）を除去することを制限しない。
　なお、上述の＜群２＞において、複合粒子群Ｂおよびその他の複合粒子群に含まれている複合粒子を用いて加圧用複合粒子を準備する際は、当該複合粒子群Ｂおよび当該その他の複合粒子群を任意の割合で混合して用いることができる。また、その際の複合粒子の混合は既知の混合方法を用いて行うことができる。 Further, for example, in the above <Group 2>, at least one of the composite particles contained in the composite particle group B and other composite particle groups is used (that is, at least the composite particle group A is used in the step (A)). A composite particle for pressurization is prepared by removing from the entire composite particle obtained). That is, in the above <Group 2>, the composite particles for pressurization may be prepared using the composite particles contained in the composite particle group B and other composite particle groups, or included in the composite particle group B. The composite particles for pressurization may be prepared using only the composite particles that are present, or the composite particles for pressurization may be prepared using only the composite particles contained in other composite particle groups.
Thus, in the step (C), it is necessary to remove at least the composite particle group A from the composite particle group used for preparing the pressurizing composite particles. Further, the step (C) is to remove the composite particle group (composite particle group B and / or other composite particle group) other than the composite particle group A from the composite particle group used for preparing the composite particles for pressurization. Do not limit.
In <Group 2> described above, when preparing the composite particles for pressurization using the composite particles contained in the composite particle group B and the other composite particle groups, the composite particle group B and the other composite particles are prepared. Particle groups can be mixed and used at an arbitrary ratio. Moreover, the mixing of the composite particles at that time can be performed using a known mixing method.
　上記同様に、例えば＜群３＞では、複合粒子群Ｂおよび２つのその他の複合粒子群の内少なくとも１つに含まれている複合粒子を用いて（つまり、少なくとも複合粒子群Ａを工程（Ａ）で得た複合粒子全体から取り除いて）加圧用複合粒子を準備する。即ち、上述の＜群３＞では、複合粒子群Ｂおよび２つのその他の複合粒子群に含まれている複合粒子を用いて加圧用複合粒子を準備してもよい。また、上述の＜群３＞では、複合粒子群Ｂ、および、２つのその他の複合粒子群の内いずれか一方に含まれている複合粒子を用いて加圧用複合粒子を準備してもよいし、２つのその他の複合粒子群に含まれている複合粒子のみを用いて加圧用複合粒子を準備してもよい。さらに、上述の＜群３＞では、複合粒子群Ｂおよび２つのその他の複合粒子群の内いずれか１つに含まれている複合粒子のみを用いて加圧用複合粒子を準備してもよい。
　ここで、加圧用複合粒子の準備に用いられる複合粒子群Ｂおよび／またはその他の複合粒子群を任意の割合で混合できることは、上記＜群２＞の場合と同様である。 Similarly to the above, for example, in <Group 3>, composite particles contained in at least one of the composite particle group B and two other composite particle groups are used (that is, at least the composite particle group A is converted into the step (A). Remove from the whole composite particles obtained in step)) to prepare composite particles for pressurization. That is, in the above <Group 3>, the composite particles for pressurization may be prepared using the composite particles contained in the composite particle group B and the two other composite particle groups. In the above <Group 3>, the composite particles for pressurization may be prepared using the composite particles contained in any one of the composite particle group B and two other composite particle groups. You may prepare the pressurization composite particle only using the composite particle contained in two other composite particle groups. Furthermore, in <Group 3> described above, the composite particles for pressurization may be prepared using only the composite particles contained in any one of the composite particle group B and two other composite particle groups.
Here, it is the same as in the case of <Group 2> that the composite particle group B and / or other composite particle groups used for preparing the composite particles for pressurization can be mixed at an arbitrary ratio.
　このように、上記工程（Ａ）、（Ｂ）、および（Ｃ）を含む加圧用複合粒子の準備工程にて得られる加圧用複合粒子は、少なくとも粗大な複合粒子群を除いた所定の複合粒子群に含まれている複合粒子を用いて準備されるため、当該加圧用複合粒子を加圧した際に、製造される複合材料シートに優れた熱伝導性を発揮させることができる。加えて、製造される複合材料シートに優れた強度および硬度を発揮させることができる。この理由は、明らかではないが、以下の通りであると推察される。
　即ち、一般に、粒子状炭素材料および樹脂を含有する複合材料を加圧することにより成形したシート等の成形体では、粒子状炭素材料同士が互いに接触して熱伝導性に優れる伝熱経路が形成されることにより、熱伝導率が向上する。ここで、粒子状炭素材料および樹脂を含有する複合材料である複合粒子を分級せずに用いる場合は、大粒子径粒子と小粒子径粒子とが混在した粒子径差の大きな複合粒子の集合体を加圧することになる。通常、粒子径差の大きな粒子の集合体を加圧すると、各粒子に圧力が均一にかかりづらい。また、加圧時に大粒子径粒子同士の隙間を小粒子径粒子が流動し易いため、当該粒子の集合体に大きなせん断力がかかりづらい。
　一方で、粒子状炭素材料および樹脂を含有する複合粒子を分級し、粗大な粒子径を有する複合粒子群を除去した複合粒子群を用いる場合は、各粒子に圧力が均一にかかり易く、また、加圧時に粒子の集合体に大きなせん断力がかかり易い。また、元来、比較的小さな粒子同士では粒子同士の相互接触面積が大きくなる。
　従って、上述の工程（Ａ）～（Ｃ）を経た所定の複合粒子群を含む加圧用複合粒子を加圧することにより製造された複合材料シート内では、粒子状炭素材料同士が良好に接触し、且つ均一に受けるせん断力により当該接触がシート面内方向に連なって配向し易い。結果として、製造される複合材料シートは、面内方向に沿って伝熱経路が良好に形成され、特にシート面内配向性を有する高い熱伝導性を発揮することができる。 Thus, the pressurizing composite particles obtained in the pressurizing composite particle preparation step including the steps (A), (B), and (C) described above are predetermined composite particles excluding at least a coarse composite particle group. Since it is prepared using the composite particles contained in the group, when the composite particles for pressurization are pressed, the manufactured composite material sheet can exhibit excellent thermal conductivity. In addition, the manufactured composite material sheet can exhibit excellent strength and hardness. The reason for this is not clear, but is presumed to be as follows.
That is, generally, in a molded body such as a sheet formed by pressurizing a composite material containing a particulate carbon material and a resin, the particulate carbon materials are in contact with each other to form a heat transfer path with excellent thermal conductivity. As a result, the thermal conductivity is improved. Here, in the case where composite particles that are a composite material containing a particulate carbon material and a resin are used without being classified, an aggregate of composite particles having a large particle size difference in which large particle size particles and small particle size particles are mixed Will be pressurized. Usually, when an aggregate of particles having a large particle size difference is pressurized, it is difficult to apply a uniform pressure to each particle. Further, since the small particle diameter particles easily flow through the gaps between the large particle diameter particles during pressurization, it is difficult to apply a large shear force to the aggregate of the particles.
On the other hand, when a composite particle group obtained by classifying composite particles containing a particulate carbon material and a resin and removing a composite particle group having a coarse particle diameter is used, it is easy to apply a uniform pressure to each particle, A large shearing force is easily applied to the aggregate of particles during pressurization. In addition, the area of mutual contact between the particles is relatively large with relatively small particles.
Accordingly, in the composite material sheet produced by pressurizing the composite particles for pressurization including the predetermined composite particle group that has undergone the above-described steps (A) to (C), the particulate carbon materials are in good contact with each other, In addition, the contact is easily aligned in the in-plane direction of the sheet due to the uniform shearing force. As a result, the manufactured composite material sheet has a good heat transfer path along the in-plane direction, and can exhibit high thermal conductivity particularly having in-plane orientation.
　また、粗大な粒子径を有する複合粒子群を除去した複合粒子群に含まれる複合粒子では、粒子状炭素材料と樹脂とが均一に複合されている。従って、当該複合粒子に上述の均一な圧力を加えた際に、粒状炭素材料同士のみならず樹脂同士も良好な配合状態で接触するため、製造される複合材料シートに優れた強度および柔軟性を発揮させることができる。 Further, in the composite particles included in the composite particle group from which the composite particle group having a coarse particle diameter is removed, the particulate carbon material and the resin are uniformly combined. Therefore, when the above-mentioned uniform pressure is applied to the composite particles, not only the granular carbon materials but also the resins come into contact with each other in a good blended state, so that the manufactured composite material sheet has excellent strength and flexibility. It can be demonstrated.
　ここで、工程（Ｃ）において用いる複合粒子を含む複合粒子群の体積平均粒子径は５００μｍ以下であることが好ましく、４００μｍ以下であることがより好ましく、３５０μｍ以下であることが更に好ましく、３００μｍ以下であることが一層好ましく、１５０μｍ以上であることが好ましい。体積平均粒子径が上記上限以下である比較的小さな複合粒子群に含まれる複合粒子を用いて得られる加圧用複合粒子を加圧すれば、上述の通り、熱伝導性、強度、および硬度が更に向上した複合材料シートを製造することができるからである。また、複合粒子群の体積平均粒子径が１５０μｍ以上であれば、過度に小さい粒子同士がシート内で接触し難く伝熱経路の形成が阻害されることを抑制できるため、良好な熱伝導性を得られるからである。 Here, the volume average particle diameter of the composite particle group including the composite particles used in the step (C) is preferably 500 μm or less, more preferably 400 μm or less, further preferably 350 μm or less, and 300 μm or less. It is more preferable that the thickness is 150 μm or more. If pressurizing composite particles for pressurization obtained using composite particles contained in a relatively small composite particle group whose volume average particle diameter is not more than the above upper limit, as described above, thermal conductivity, strength, and hardness are further increased. This is because an improved composite material sheet can be produced. In addition, if the volume average particle diameter of the composite particle group is 150 μm or more, it is possible to suppress the formation of heat transfer paths that are difficult to contact with each other in an excessively small particle, so that good thermal conductivity is achieved. It is because it is obtained.
［［加圧用複合粒子］］
　工程（Ｃ）で得られる加圧用複合粒子は、後述する加圧工程を経ることにより、複合材料シートを構成する。また、工程（Ｃ）で得られる加圧用複合粒子は、上述の通り、複合粒子群Ａ以外の複合粒子群に含まれている複合粒子を用いて準備される。そして、複合粒子群Ａ以外の比較的小さな複合粒子群に含まれる複合粒子を用いて得られる加圧用複合粒子を加圧することにより、製造される複合材料シートに高い熱伝導性、高い強度、および良好な硬度を与えることできる。 [[Composite particles for pressurization]]
The composite particles for pressurization obtained in the step (C) constitute a composite material sheet through a pressurization step described later. Moreover, the composite particle for pressurization obtained at a process (C) is prepared using the composite particle contained in composite particle groups other than the composite particle group A as above-mentioned. And by pressurizing the composite particles for press obtained using the composite particles contained in a relatively small composite particle group other than the composite particle group A, the composite material sheet to be manufactured has high thermal conductivity, high strength, and Good hardness can be given.
－加圧用複合粒子の性状－
　ここで、加圧用複合粒子は、粒子径５００μｍ以上の複合粒子の含有率が４０体積％未満であることが好ましく、３５体積％未満であることがより好ましく、２５体積％未満であることが更に好ましい。分級された比較的大きな複合粒子群を除去し、粒子径５００μｍ以上の複合粒子の含有率を４０体積％未満とした加圧用複合粒子を後述の加圧工程にて加圧すれば、熱伝導性、強度、および硬度が更に向上した複合材料シートを製造することができるからである。
　なお、加圧用複合粒子の粒子径分布は、上記工程（Ｂ）における複合粒子の分級方法および加圧用複合粒子の準備に用いる複合粒子群の組み合わせ方を変更することにより調整することができる。 -Properties of pressurized composite particles-
Here, in the composite particles for pressurization, the content of the composite particles having a particle diameter of 500 μm or more is preferably less than 40% by volume, more preferably less than 35% by volume, and further preferably less than 25% by volume. preferable. By removing a relatively large group of classified composite particles and pressurizing composite particles for pressurization with a content of composite particles having a particle diameter of 500 μm or more to less than 40% by volume in a pressurizing step described later, thermal conductivity This is because a composite material sheet with further improved strength and hardness can be produced.
The particle size distribution of the pressurizing composite particles can be adjusted by changing the method of classifying the composite particles in the step (B) and the method of combining the composite particle groups used for preparing the pressurizing composite particles.
＜加圧工程＞
　そして、本発明の複合材料シートの製造方法は、上述した加圧用複合粒子の準備工程で準備された加圧用複合粒子を加圧してシート状に成形することにより複合材料シートを得る、加圧工程を含むことを必要とする。上述の所定の加圧用複合粒子に圧力を加えれば、面内方向に優れた熱伝導性を有しつつ、高い強度および良好な硬度を並立させた複合材料シートを製造することができる。 <Pressurization process>
And the manufacturing method of the composite material sheet | seat of this invention is a pressurization process which obtains a composite material sheet | seat by pressurizing the composite particle for pressurization prepared by the preparatory process of the composite particle for pressurization mentioned above, and shape | molding in a sheet form. Need to contain. If pressure is applied to the above-mentioned predetermined composite particles for pressurization, it is possible to produce a composite material sheet having excellent thermal conductivity in the in-plane direction and having high strength and good hardness arranged side by side.
［加圧方法］
　ここで、加圧は、加圧用複合粒子に圧力が負荷される成形方法であれば特に限定されることなく、プレス成形、圧延成形または押し出し成形などの既知の成形方法を行うことができる。中でも、加圧用複合粒子は、圧延成形によりシート状に成形することが好ましく、保護フィルムに挟んだ状態でロール間を通過させてシート状に成形することがより好ましい。なお、保護フィルムとしては、特に限定されることなく、サンドブラスト処理を施したポリエチレンテレフタレート（ＰＥＴ）フィルム、シリコーン離型処理を施したＰＥＴフィルム等を用いることができる。また、ロール温度は５℃以上１５０℃以下、ロール間隙は５０μｍ以上２５００μｍ以下、ロール線圧は１ｋｇ／ｃｍ以上３０００ｋｇ／ｃｍ以下、ロール速度は０．１ｍ／分以上２０ｍ／分以下とすることができる。 [Pressurization method]
Here, pressurization is not particularly limited as long as it is a molding method in which pressure is applied to the pressurizing composite particles, and a known molding method such as press molding, rolling molding or extrusion molding can be performed. Especially, it is preferable to shape | mold the composite particle for pressurization in a sheet form by rolling, and it is more preferable to pass between rolls in the state pinched | interposed into the protective film, and to shape | mold into a sheet form. In addition, as a protective film, it does not specifically limit, The polyethylene terephthalate (PET) film which performed the sandblasting process, the PET film which performed the silicone mold release process, etc. can be used. The roll temperature is 5 ° C. or more and 150 ° C. or less, the roll gap is 50 μm or more and 2500 μm or less, the roll linear pressure is 1 kg / cm or more and 3000 kg / cm or less, and the roll speed is 0.1 m / min or more and 20 m / min or less. it can.
　そして、加圧工程を経て製造された複合材料シートでは、上述の通り粒子状炭素材料が主としてシート面内方向に配列すると推察される。更に、当該複合材料シートでは、粒子状炭素材料同士の接触によって面内方向に伝熱経路が良好に形成される。従って、上記製造方法を用いて製造された複合材料シートは、特に面内方向の熱伝導性が向上すると推察される。また、上記製造方法を用いて製造された複合材料シートは、上述の通り、強度および硬度にも優れている。
　なお、複合材料シートの厚みは、特に限定されることなく、例えば、０．０５ｍｍ以上２ｍｍ以下とすることができる。また、複合材料シートの熱伝導性を更に向上させる観点からは、複合材料シートの厚みは、複合材料シートの製造に用いられる粒子状炭素材料の体積基準モード径の１倍超５０００倍以下であることが好ましい。 And in the composite material sheet | seat manufactured through the pressurization process, it is guessed that a particulate carbon material arranges mainly in a sheet surface direction as above-mentioned. Furthermore, in the said composite material sheet, a heat-transfer path | route is favorably formed in an in-plane direction by contact between particulate carbon materials. Therefore, it is presumed that the composite material sheet manufactured using the above-described manufacturing method improves the thermal conductivity particularly in the in-plane direction. Moreover, the composite material sheet manufactured using the said manufacturing method is excellent also in intensity | strength and hardness as above-mentioned.
In addition, the thickness of a composite material sheet is not specifically limited, For example, it can be 0.05 mm or more and 2 mm or less. Further, from the viewpoint of further improving the thermal conductivity of the composite material sheet, the thickness of the composite material sheet is more than 1 time and not more than 5000 times the volume standard mode diameter of the particulate carbon material used for manufacturing the composite material sheet. It is preferable.
（熱伝導シートの製造方法）
　本発明の熱伝導シートの製造方法では、例えば、本発明の複合材料シートの製造方法によって製造された複合材料シートを用いて積層体を得る工程（積層工程）と、積層体をスライスする工程（スライス工程）とを経て熱伝導シートを製造することができる。上述の複合材料シートに積層工程およびスライス工程を施すことにより、シート厚み方向の熱伝導性、強度、および硬度の全てに優れた熱伝導シートを製造することができる。
　以下、各工程について具体的に説明する。 (Method for producing heat conductive sheet)
In the manufacturing method of the heat conductive sheet of this invention, the process (lamination process) of obtaining a laminated body using the composite material sheet manufactured by the manufacturing method of the composite material sheet of this invention, and the process of slicing a laminated body (for example) Through the slicing step, a heat conductive sheet can be manufactured. By subjecting the above-mentioned composite material sheet to a laminating step and a slicing step, it is possible to produce a heat conductive sheet excellent in all of the heat conductivity, strength, and hardness in the sheet thickness direction.
Hereinafter, each step will be specifically described.
＜積層工程＞
　積層体を得る工程（積層工程）では、上述した複合材料シートの製造方法を用いて製造した複合材料シートを厚み方向に複数枚積層して、或いは、上述した複合材料シートの製造方法を用いて製造した複合材料シートを折畳または捲回して、積層体を得る。ここで、複合材料シートの積層による積層体の形成は、特に限定されることなく、積層装置を用いて行ってもよく、手作業にて行ってもよい。また、複合材料シートの折畳による積層体の形成は、特に限定されることなく、折畳機を用いて複合材料シートを一定幅で折り畳むことにより行うことができる。さらに、複合材料シートの捲回による積層体の形成は、特に限定されることなく、複合材料シートの短手方向または長手方向に平行な軸の回りに複合材料シートを捲き回すことにより行うことができる。 <Lamination process>
In the step of obtaining a laminate (lamination step), a plurality of composite material sheets manufactured using the above-described composite material sheet manufacturing method are stacked in the thickness direction, or the above-described composite material sheet manufacturing method is used. The manufactured composite material sheet is folded or wound to obtain a laminate. Here, formation of the laminated body by lamination | stacking of a composite material sheet | seat is not specifically limited, You may carry out using a lamination apparatus, and may carry out manually. Moreover, formation of the laminated body by folding of a composite material sheet is not specifically limited, It can carry out by folding a composite material sheet by fixed width using a folding machine. Furthermore, the formation of the laminate by winding the composite material sheet is not particularly limited, and can be performed by winding the composite material sheet around an axis parallel to the short side direction or the long side direction of the composite material sheet. it can.
　ここで、通常、積層工程で得られる積層体において、複合材料シートの表面同士の接着力は、複合材料シートを積層する際の圧力や折畳または捲回する際の引っ張り力により充分に得られる。しかし、接着力が不足する場合や、積層体の層間剥離を十分に抑制する必要がある場合には、複合材料シートの表面を溶剤で若干溶解させた状態で積層工程を行ってもよいし、複合材料シートの表面に接着剤を塗布した状態または複合材料シートの表面に接着層を設けた状態で積層工程を行ってもよい。 Here, usually, in the laminate obtained in the lamination step, the adhesive force between the surfaces of the composite material sheet is sufficiently obtained by the pressure at the time of laminating the composite material sheet and the pulling force at the time of folding or winding. . However, if the adhesive force is insufficient or if it is necessary to sufficiently suppress delamination of the laminate, the lamination step may be performed in a state where the surface of the composite material sheet is slightly dissolved with a solvent, The laminating step may be performed in a state where an adhesive is applied to the surface of the composite material sheet or an adhesive layer is provided on the surface of the composite material sheet.
　なお、複合材料シートの表面を溶解させる際に用いる溶剤としては、特に限定されることなく、複合材料シート中に含まれている樹脂を溶解可能な既知の溶剤（例えば、メチルエチルケトンなど）を用いることができる。 The solvent used for dissolving the surface of the composite material sheet is not particularly limited, and a known solvent (for example, methyl ethyl ketone) that can dissolve the resin contained in the composite material sheet is used. Can do.
　また、複合材料シートの表面に塗布する接着剤としては、特に限定されることなく、市販の接着剤や粘着性の樹脂を用いることができる。また、複合材料シートの表面に設ける接着層としては、特に限定されることなく、両面テープなどを用いることができる。中でも、接着層としては、接着性に優れるアクリル系粘着剤を有する接着層を設けることが好ましい。そして、複合材料シートの表面に塗布する接着剤または複合材料シートの表面に設ける接着層の厚さは、例えば、１μｍ以上１０００μｍ以下とすることができる。
　ここで、接着剤や接着層には、得られる熱伝導シートが硬くなりすぎない範囲で熱伝導性フィラーが配合されていてもよい。 Moreover, it does not specifically limit as an adhesive agent apply | coated to the surface of a composite material sheet, A commercially available adhesive agent and adhesive resin can be used. The adhesive layer provided on the surface of the composite material sheet is not particularly limited, and a double-sided tape or the like can be used. Especially, as an adhesive layer, it is preferable to provide the adhesive layer which has an acrylic adhesive which is excellent in adhesiveness. And the thickness of the adhesive agent apply | coated to the surface of a composite material sheet or the contact bonding layer provided in the surface of a composite material sheet can be 1 micrometer or more and 1000 micrometers or less, for example.
Here, the heat conductive filler may be mix | blended with the adhesive agent or the contact bonding layer in the range by which the heat conductive sheet obtained does not become hard too much.
　なお、層間剥離を抑制する観点からは、得られた積層体は、積層方向に０．１ＭＰａ以上０．５ＭＰａ以下の圧力で押し付けながら、５０℃以上１７０℃以下で１０分～８時間加熱してもよい。 From the viewpoint of suppressing delamination, the obtained laminate is heated at 50 ° C. or more and 170 ° C. or less for 10 minutes to 8 hours while being pressed at a pressure of 0.1 MPa or more and 0.5 MPa or less in the lamination direction. Also good.
　そして、複合材料シートを積層、折畳または捲回して得られる積層体では、粒子状炭素材料および任意の繊維状炭素材料が積層方向に略直交する方向に配列していると推察される。また、当該積層体では、粒子状炭素材料同士、または粒子状炭素材料および繊維状炭素材料の良好な接触によって形成される伝熱経路が、主に積層方向に略直交する方向に配列していると推察される。 And in the laminate obtained by laminating, folding or winding the composite material sheet, it is presumed that the particulate carbon material and any fibrous carbon material are arranged in a direction substantially perpendicular to the laminating direction. In the laminate, the heat transfer path formed by the good contact between the particulate carbon materials or between the particulate carbon material and the fibrous carbon material is arranged mainly in a direction substantially orthogonal to the lamination direction. It is guessed.
＜スライス工程＞
　スライス工程では、上述の積層工程で得られた積層体を、積層方向に対して４５°以下の角度でスライスし、積層体のスライス片よりなる熱伝導シートを得る。ここで、積層体をスライスする方法としては、特に限定されることなく、例えば、ワイヤーソー法、マルチブレード法、レーザー加工法、ウォータージェット法、ナイフ加工法等が挙げられる。中でも、熱伝導シートの厚みを均一にし易い点で、ナイフ加工法が好ましい。また、積層体をスライスする際の切断具としては、特に限定されることなく、スリットを有する平滑な盤面と、当該スリット部より突出した刃部とを有するスライス部材（例えば、鋭利な刃を備えたカッター、カンナ、スライサー）を用いることができる。 <Slicing process>
In the slicing step, the laminated body obtained in the above-described laminating step is sliced at an angle of 45 ° or less with respect to the laminating direction to obtain a heat conductive sheet composed of sliced pieces of the laminated body. Here, the method for slicing the laminate is not particularly limited, and examples thereof include a wire saw method, a multi-blade method, a laser processing method, a water jet method, and a knife processing method. Especially, the knife processing method is preferable at the point which makes the thickness of a heat conductive sheet uniform. The cutting tool for slicing the laminate is not particularly limited, and includes a slice member (for example, a sharp blade) having a smooth board surface having a slit and a blade portion protruding from the slit portion. Cutter, canna, slicer) can be used.
　なお、熱伝導シートの熱伝導性を高める観点からは、積層体をスライスする角度は、積層方向に対して３０°以下であることが好ましく、積層方向に対して１５°以下であることがより好ましく、積層方向に対して略０°である（即ち、積層方向に沿う方向である）ことが更に好ましい。 In addition, from the viewpoint of increasing the thermal conductivity of the heat conductive sheet, the angle at which the laminate is sliced is preferably 30 ° or less with respect to the stacking direction, and more preferably 15 ° or less with respect to the stacking direction. Preferably, it is substantially 0 ° with respect to the stacking direction (that is, a direction along the stacking direction).
　また、積層体を容易にスライスする観点からは、スライスする際の積層体の温度は－２０℃以上８０℃以下とすることが好ましく、－１０℃以上５０℃以下とすることがより好ましい。更に、同様の理由により、スライスする積層体は、積層方向とは垂直な方向に圧力を負荷しながらスライスすることが好ましく、積層方向とは垂直な方向に０．０５ＭＰａ以上０．５ＭＰａ以下の圧力を負荷しながらスライスすることがより好ましい。 Further, from the viewpoint of easily slicing the laminate, the temperature of the laminate when slicing is preferably −20 ° C. or more and 80 ° C. or less, and more preferably −10 ° C. or more and 50 ° C. or less. Further, for the same reason, the laminated body to be sliced is preferably sliced while applying a pressure in a direction perpendicular to the lamination direction, and a pressure of 0.05 MPa to 0.5 MPa in a direction perpendicular to the lamination direction. It is more preferable to slice while loading.
　そして、スライス工程を経て得られた熱伝導シートでは、粒子状炭素材料および任意の繊維状炭素材料が熱伝導シートの厚み方向（即ち、プレ熱伝導シートとしての複合材料シートの積層方向に略直交する方向）に配列していると推察される。また、当該熱伝導シートでは、粒子状炭素材料同士、または粒子状炭素材料および繊維状炭素材料の良好な接触によって形成される伝熱経路が、主に熱伝導シートの厚み方向に配列していると推察される。従って、当該熱伝導シートは、厚み方向の熱伝導性に優れている。
　また、前述した複合材料シートは強度および硬度にも優れているので、当該複合材料シートを用いて製造した熱伝導シートも、強度および硬度に優れていると推察される。 And in the heat conductive sheet obtained through the slicing step, the particulate carbon material and any fibrous carbon material are substantially orthogonal to the thickness direction of the heat conductive sheet (that is, the lamination direction of the composite material sheet as the pre heat conductive sheet). It is inferred that they are arranged in the direction of Moreover, in the said heat conductive sheet, the heat-transfer path | route formed by the favorable contact of particulate carbon materials or a particulate carbon material and a fibrous carbon material has mainly arranged in the thickness direction of the heat conductive sheet. It is guessed. Therefore, the said heat conductive sheet is excellent in the heat conductivity of the thickness direction.
Moreover, since the composite material sheet mentioned above is excellent also in intensity | strength and hardness, it is guessed that the heat conductive sheet manufactured using the said composite material sheet is also excellent in intensity | strength and hardness.
　以下、本発明について実施例に基づき具体的に説明するが、本発明はこれら実施例に限定されるものではない。なお、以下の説明において、量を表す「％」および「部」は、特に断らない限り、質量基準である。
　実施例および比較例において、熱伝導シート中の膨張化黒鉛の粒子径、複合粒子群および加圧用複合粒子の体積平均粒子径、加圧用複合粒子中における粒子径５００μｍ以上の複合粒子の含有率、複合材料シートの強度、複合材料シートの硬度、および熱伝導シートの熱伝導率は、それぞれ以下の方法を使用して測定、算出、または評価した。 EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the following description, “%” and “part” representing amounts are based on mass unless otherwise specified.
In Examples and Comparative Examples, the particle diameter of expanded graphite in the heat conductive sheet, the volume average particle diameter of the composite particles and the composite particles for pressurization, the content of composite particles having a particle diameter of 500 μm or more in the composite particles for pressurization, The strength of the composite material sheet, the hardness of the composite material sheet, and the thermal conductivity of the heat conductive sheet were measured, calculated, or evaluated using the following methods, respectively.
＜熱伝導シート中の膨張化黒鉛の粒子径＞
　製造された熱伝導シート３ｇを、メチルエチルケトン溶媒６ｇ内でスターラーを用いて５分間撹拌した後、目視により、メチルエチルケトン溶媒中にシート状のものが存在しないことを確認し、熱伝導シート中に含まれている粒子状炭素材料としての膨張化黒鉛を含有する懸濁液を得た。レーザー回折／散乱式粒子径分布測定装置（堀場製作所製、型番「ＬＡ－９６０」）を用いて、得られた懸濁液中に含まれる膨張化黒鉛の粒子径を測定した。そして、横軸を粒子径、縦軸を膨張化黒鉛の存在比率（体積基準）とした粒子径分布曲線を得て、当該粒子径分布曲線の極大値における粒子径を、膨張化黒鉛の体積基準のモード径（μｍ）として求めた。結果を表1に示す。 <Particle size of expanded graphite in heat conductive sheet>
3 g of the manufactured heat conductive sheet was stirred for 5 minutes in 6 g of methyl ethyl ketone solvent using a stirrer, and then visually confirmed that there was no sheet-like material in the methyl ethyl ketone solvent, and contained in the heat conductive sheet. A suspension containing expanded graphite as a particulate carbon material was obtained. The particle diameter of the expanded graphite contained in the obtained suspension was measured using a laser diffraction / scattering particle size distribution measuring apparatus (manufactured by Horiba, model number “LA-960”). Then, a particle size distribution curve is obtained in which the horizontal axis is the particle size and the vertical axis is the abundance ratio of expanded graphite (volume basis), and the particle size at the maximum value of the particle size distribution curve is determined based on the volume basis of the expanded graphite. The mode diameter (μm) was obtained. The results are shown in Table 1.
＜複合粒子群および加圧用複合粒子の体積平均粒子径＞
　各複合粒子群および加圧用複合粒子１００ｍｇをそれぞれ試料とし、レーザー回折／散乱式粒子径分布測定装置（日機装製、型番「マイクロトラックＭＴ３３００ＥＸ－ＩＩ」）を用いて、各複合粒子群および加圧用複合粒子の粒子径分布を得た。そして、得られた粒子径分布（体積基準）において小径側から計算した累積体積が５０％となる中心粒子径（Ｄ５０）を、複合粒子群に含まれている複合粒子の体積平均粒子径（μｍ）および加圧用複合粒子の体積平均粒子径（μｍ）として算出した。結果を表１に示す。 <Volume average particle diameter of composite particle group and composite particle for pressurization>
Each composite particle group and 100 mg of composite particles for pressurization were used as samples, and each composite particle group and pressurization composite were measured using a laser diffraction / scattering particle size distribution measuring device (manufactured by Nikkiso, model number “Microtrack MT3300EX-II”). A particle size distribution of the particles was obtained. Then, in the obtained particle diameter distribution (volume basis), the central particle diameter (D50) at which the cumulative volume calculated from the small diameter side becomes 50% is determined as the volume average particle diameter (μm) of the composite particles included in the composite particle group. ) And the volume average particle diameter (μm) of the composite particles for pressurization. The results are shown in Table 1.
＜加圧用複合粒子中における粒子径５００μｍ以上の複合粒子の含有率＞
　各加圧用複合粒子１００ｍｇを試料とし、レーザー回折／散乱式粒子径分布測定装置（日機装製、型番「マイクロトラックＭＴ３３００ＥＸ－ＩＩ」）を用いて、各加圧用複合粒子の粒子径分布を得た。そして、得られた粒子径分布から、粒子径５００μｍ以上の複合粒子の含有率（体積％）を算出した。結果を表１に示す。 <Content of composite particles having a particle diameter of 500 μm or more in the composite particles for pressurization>
Using 100 mg of each composite particle for pressurization as a sample, a particle size distribution of each composite particle for pressurization was obtained using a laser diffraction / scattering particle size distribution measuring device (manufactured by Nikkiso, model number “Microtrack MT3300EX-II”). And the content rate (volume%) of the composite particle with a particle diameter of 500 micrometers or more was computed from the obtained particle diameter distribution. The results are shown in Table 1.
＜複合材料シートの強度＞
　製造された複合材料シートを２０ｍｍ×８０ｍｍのサイズで打ち抜き、試験体を得た。得られた試験体に対し、小型卓上試験機（日本電産シンポ製、型番「ＦＧＳ－５００ＴＶ」、デジタルフォースゲージとしてＦＧＰ－５０を使用）を用いて、引張り速度２０ｍｍ／分、チャック間距離６０ｍｍにて引張り試験を行うことにより、最大引張り強度（Ｎ）および最大時の伸びとして破断距離（ｍｍ）を測定した。得られた引張り強度および破断距離が大きい程、複合材料シートの強度が高いことを示す。結果を表１に示す。 <Strength of composite material sheet>
The manufactured composite material sheet was punched out in a size of 20 mm × 80 mm to obtain a test body. Using a small tabletop testing machine (manufactured by Nidec Sympo, model number “FGS-500TV”, using FGP-50 as a digital force gauge), the test specimen obtained was pulled at a speed of 20 mm / min and the distance between chucks was 60 mm. By carrying out a tensile test, the breaking distance (mm) was measured as the maximum tensile strength (N) and the maximum elongation. It shows that the intensity | strength of a composite material sheet is so high that the obtained tensile strength and breaking distance are large. The results are shown in Table 1.
＜複合材料シートの硬度＞
　複合材料シートの硬度は、複合材料シートを複数枚重ねた試験体（複合材料シート層）の硬度として評価した。ここで硬度は、日本ゴム協会規格（ＳＲＩＳ）のアスカーＣ法に準拠し測定した。
　具体的には、実施例および比較例で得られた複合材料シートを幅２５ｍｍ×長さ５０ｍｍ×厚さ０．５ｍｍの大きさに切り取り、２４枚重ね合わせることにより試験片を得た。得られた試験片を温度２３℃に保たれた恒温室内に４８時間以上静置することにより、試験体としての複合材料シート層を得た。次に、指針が９５～９８となるようにダンパー高さを調整し、複合材料シート層とダンパーとを衝突させた。当該衝突から６０秒後の複合材料シート層のアスカーＣ硬度を、硬度計（高分子計器社製、製品名「ＡＳＫＥＲ ＣＬ－１５０ＬＪ」）を用いて２回測定し、測定結果の平均値を採用した。アスカーＣ硬度が小さいほど、柔軟で、硬度に優れた複合材料シートであることを表す。結果を表１に示す。 <Hardness of composite material sheet>
The hardness of the composite material sheet was evaluated as the hardness of a specimen (composite material sheet layer) in which a plurality of composite material sheets were stacked. Here, the hardness was measured according to the Asker C method of the Japan Rubber Association Standard (SRIS).
Specifically, the composite material sheets obtained in Examples and Comparative Examples were cut into a size of 25 mm wide × 50 mm long × 0.5 mm thick, and a test piece was obtained by stacking 24 sheets. The obtained test piece was allowed to stand in a temperature-controlled room maintained at a temperature of 23 ° C. for 48 hours or longer to obtain a composite material sheet layer as a test body. Next, the height of the damper was adjusted so that the pointer became 95 to 98, and the composite material sheet layer and the damper were made to collide with each other. The Asker C hardness of the composite material sheet layer 60 seconds after the collision was measured twice using a hardness meter (product name “ASKER CL-150LJ” manufactured by Kobunshi Keiki Co., Ltd.), and the average value of the measurement results was adopted. did. The smaller the Asker C hardness, the more flexible and excellent the composite sheet. The results are shown in Table 1.
＜熱伝導シートの熱伝導率＞
　実施例および比較例で製造した熱伝導シートについて、厚み方向の熱拡散率α（ｍ２／ｓ）、定圧比熱Ｃｐ（Ｊ／ｇ・Ｋ）および比重ρ（ｇ／ｍ３）を以下の方法で測定した。
［熱拡散率］
　熱物性測定装置（株式会社ベテル製、製品名「サーモウェーブアナライザＴＡ３５」）を使用して温度２５℃における熱拡散率を測定した。
［定圧比熱］
　示差走査熱量計（Ｒｉｇａｋｕ製、製品名「ＤＳＣ８２３０」）を使用し、１０℃／分の昇温条件下、温度２５℃における比熱を測定した。
［比重］
　自動比重計（東洋精機社製、製品名「ＤＥＮＳＩＭＥＴＥＲ－Ｈ」）を用いて測定した。
　そして、得られた測定値を用いて下記式（Ｉ）：
　　λ＝α×Ｃｐ×ρ　・・・（Ｉ）
より温度２５℃における熱伝導シートの熱伝導率λ（Ｗ／ｍ・Ｋ）を求めた。λ値が大きいほど、厚み方向の熱伝導性に優れた熱伝導性シートであることを表す。結果を表１に示す。 <Thermal conductivity of thermal conductive sheet>
About the heat conductive sheet manufactured by the Example and the comparative example, thermal diffusivity (alpha) (m < 2 > / s) of thickness direction, constant-pressure specific heat Cp (J / g * K), and specific gravity (rho) (g / m < 3 >) are the following methods. Measured with
[Thermal diffusivity]
The thermal diffusivity at a temperature of 25 ° C. was measured using a thermophysical property measuring apparatus (product name “Thermo Wave Analyzer TA35” manufactured by Bethel Co., Ltd.).
[Specific pressure specific heat]
Using a differential scanning calorimeter (manufactured by Rigaku, product name “DSC8230”), the specific heat at a temperature of 25 ° C. was measured under a temperature rising condition of 10 ° C./min.
[specific gravity]
The measurement was made using an automatic hydrometer (product name “DENSIMTER-H” manufactured by Toyo Seiki Co., Ltd.).
And the following formula (I):
λ = α × Cp × ρ (I)
Further, the thermal conductivity λ (W / m · K) of the thermal conductive sheet at a temperature of 25 ° C. was determined. It represents that it is a heat conductive sheet excellent in the heat conductivity of the thickness direction, so that (lambda) value is large. The results are shown in Table 1.
（実施例１）
＜加圧用複合粒子の準備工程＞
［工程（Ａ）］
［［混練段階］］
　粒子状炭素材料としての膨張化黒鉛（伊藤黒鉛工業製、製品名「ＥＣ－５０」、平均粒子径：２５０μｍ）を１３０部と、繊維状炭素材料としてのＣＮＴ易分散集合体を１部と、樹脂としてのフッ素樹脂（ダイキン工業製、製品名「ダイエルＧ－９１２」）を８０部と、難燃剤としてのリン酸エステル（味の素ファインテクノ社製、製品名「レオフォス６５」）を１０部とを、ニーダー（井上製作所製）を用いて５０℃にて３０分撹拌混練し、膨張化黒鉛と、ＣＮＴと、フッ素樹脂と、リン酸エステルとを含有する混練物を得た。
　なお、用いたＣＮＴ易分散集合体は、以下の方法で調製した。 Example 1
<Preparation process of composite particles for pressurization>
[Step (A)]
[[Kneading stage]]
130 parts of expanded graphite (product name “EC-50”, average particle size: 250 μm) as a particulate carbon material, 1 part of a CNT easy dispersion aggregate as a fibrous carbon material, 80 parts of fluororesin (made by Daikin Industries, product name “DAIEL G-912”) as resin, and 10 parts of phosphoric ester (product name “LEOFOS 65”, manufactured by Ajinomoto Fine Techno Co., Ltd.) as flame retardant The mixture was stirred and kneaded at 50 ° C. for 30 minutes using a kneader (manufactured by Inoue Seisakusho) to obtain a kneaded product containing expanded graphite, CNT, fluororesin, and phosphate ester.
In addition, the used CNT easy-dispersed aggregate was prepared by the following method.
－ＣＮＴ易分散集合体の調製－
　上述のスーパーグロース法によってＳＧＣＮＴを含む繊維状炭素材料を得た。得られた繊維状炭素材料は、ＢＥＴ比表面積が８００ｍ２／ｇであった。また、透過型電子顕微鏡を用い、無作為に選択した１００本の繊維状炭素材料の直径および長さを測定した結果、平均直径が３．３ｎｍ、平均長さが１００μｍであった。更に、得られた繊維状炭素材料は、主に単層ＣＮＴにより構成されていた。
　次に、得られた繊維状炭素材料を、分散媒としてのメチルエチルケトンに分散させて得た分散液から、ろ紙（桐山社製、Ｎｏ．５Ａ）を用いて減圧ろ過して溶媒を除去することにより、繊維状炭素材料としての、ＳＧＣＮＴを含むＣＮＴ易分散集合体を得た。ＣＮＴなどの繊維状炭素材料は一般的に凝集し易いため、このように易分散性集合体の状態にすることにより、他の成分との混合を容易にすることができる。 -Preparation of CNT easily dispersed aggregate-
A fibrous carbon material containing SGCNT was obtained by the above-described super-growth method. The obtained fibrous carbon material had a BET specific surface area of 800 m 2 / g. Further, as a result of measuring the diameter and length of 100 randomly selected fibrous carbon materials using a transmission electron microscope, the average diameter was 3.3 nm and the average length was 100 μm. Furthermore, the obtained fibrous carbon material was mainly composed of single-walled CNTs.
Next, by removing the solvent from the dispersion obtained by dispersing the obtained fibrous carbon material in methyl ethyl ketone as a dispersion medium using a filter paper (Kiriyama Co., No. 5A) under reduced pressure. As a fibrous carbon material, a CNT easy-dispersed aggregate containing SGCNT was obtained. Since a fibrous carbon material such as CNT is generally easily aggregated, mixing with other components can be facilitated by setting it in such a state of an easily dispersible aggregate.
［［粉砕段階］］
　上述で得られた混練物を、コーヒーミル（カリタ製、型番「ＣＭ－５０」）を用いて、２５℃にて約３０秒間粉砕し、膨張化黒鉛と、ＣＮＴと、フッ素樹脂と、リン酸エステルとを含有する複合粒子を得た。 [[Crushing stage]]
The kneaded material obtained above was pulverized for about 30 seconds at 25 ° C. using a coffee mill (manufactured by Carita, model number “CM-50”), and expanded graphite, CNT, fluororesin, and phosphoric acid. Composite particles containing ester were obtained.
［工程（Ｂ）］
　上述で得られた複合粒子を、ふるい（東京スクリーン製、目開き：１５０μｍ、２５０μｍ）を用いて２５℃にて分級することにより、それぞれ複合粒子群Ａ（目開き２５０μｍのふるい上）、複合粒子群Ｂ（目開き１５０μｍのふるい下）、およびその他の複合粒子群（目開き：１５０μｍのふるい上および２５０μｍのふるい下）の３つの複合粒子群を得た。 [Step (B)]
The composite particles obtained above are classified at 25 ° C. using sieves (manufactured by Tokyo Screen, openings: 150 μm, 250 μm), so that each of composite particle groups A (on a sieve having openings of 250 μm), composite particles Three composite particle groups were obtained: Group B (under a sieve having an opening of 150 μm) and other composite particles (aperture: above a sieve of 150 μm and under a sieve of 250 μm).
［工程（Ｃ）］
　上述で得られた３つの複合粒子群のうち、複合粒子群Ａおよび複合粒子群Ｂを除去し、その他の複合粒子群に含まれる複合粒子のみをそのまま加圧用複合粒子として採用した。
　そして、採用した複合粒子群（つまり、加圧用複合粒子）の体積平均粒子径、および、得られた加圧用複合粒子中における粒子径５００μｍ以上の複合粒子の含有率を算出した。結果を表１に示す。 [Step (C)]
Of the three composite particle groups obtained above, the composite particle group A and the composite particle group B were removed, and only the composite particles contained in the other composite particle groups were directly employed as the pressurizing composite particles.
Then, the volume average particle size of the employed composite particle group (that is, the composite particle for pressurization) and the content ratio of the composite particle having a particle size of 500 μm or more in the obtained composite particle for pressurization were calculated. The results are shown in Table 1.
＜加圧工程＞
　上述の通り得られた加圧用複合粒子１０ｇを、サンドブラスト処理を施した厚さ５０μｍのＰＥＴフィルム（保護フィルムＡ）と片面のシリコーン離型処理を施した厚さ７５μｍのＰＥＴフィルム（保護フィルムＢ）とで挟み、ロール間隙３５０μｍ、ロール温度５０℃、ロール線圧５０ｋｇ／ｃｍ、ロール速度１ｍ／分の条件にて圧延成形することにより、厚さ０．５ｍｍの複合材料シートを得た。
　そして、得られた複合材料シートの強度、および硬度（アスカーＣ硬度）を測定した。結果を表１に示す。 <Pressurization process>
10 g of the composite particles for pressurization obtained as described above were subjected to sandblast treatment and a PET film (protective film A) having a thickness of 50 μm and PET film (protective film B) having a thickness of 75 μm subjected to one-side silicone release treatment. Was rolled and formed under the conditions of a roll gap of 350 μm, a roll temperature of 50 ° C., a roll linear pressure of 50 kg / cm, and a roll speed of 1 m / min, to obtain a composite material sheet having a thickness of 0.5 mm.
And the intensity | strength and hardness (Asker C hardness) of the obtained composite material sheet were measured. The results are shown in Table 1.
＜積層工程＞
　上述で得られた複合材料シートのいずれか任意の片面に両面テープ（日栄化工製、製品名「ＮｅｏＦｉｘ１０」、厚み：１０μｍ）を貼付けた。次に、複合材料シートにおける当該両面テープが貼付けられた面側と、別の複合材料シートにおける両面テープが貼付けられていない面側とを合わせ、同様の作業を１２０枚分繰り返すことにより、厚さ約６ｃｍの積層体を得た。得られた積層体を手押しにて圧縮し、複合材料シートの各接着面を密着させた。 <Lamination process>
A double-sided tape (manufactured by Nichiei Kako, product name “NeoFix10”, thickness: 10 μm) was attached to any one side of the composite material sheet obtained above. Next, by combining the surface side of the composite material sheet on which the double-sided tape is applied and the surface side of another composite material sheet on which the double-sided tape is not applied, and repeating the same operation for 120 sheets, the thickness is increased. A laminate of about 6 cm was obtained. The obtained laminate was compressed by hand, and the adhesive surfaces of the composite material sheet were brought into close contact with each other.
　＜スライス工程＞
　その後、複合材料シートの積層体を、積層断面を０．３ＭＰａの圧力で押し付けながら、木工用スライサー（丸仲鐵工所製、製品名「超仕上げかんな盤スーパーメカ」、刃部の突出長は０．１１ｍｍ）を用いて、２ｍｍ／分の速度で、積層方向に対して０度の角度でスライス（換言すれば、積層された複合材料シートの主面の法線方向にスライス）し、厚さ０．５０ｍｍの熱伝導シートを得た。
　そして、得られた熱伝導シート中の膨張化黒鉛の粒子径、および熱伝導シートの熱伝導率を算出した。結果を表１に示す。 <Slicing process>
After that, while pressing the laminate of the composite material sheet with a pressure of 0.3 MPa, the slicer for woodworking (manufactured by Marunaka Co., Ltd., product name “Super-finished plane super mechanism”, the protruding length of the blade is 0.11 mm) at a speed of 2 mm / min and sliced at an angle of 0 degrees with respect to the stacking direction (in other words, sliced in the normal direction of the main surface of the laminated composite material sheet) A heat conductive sheet having a thickness of 0.50 mm was obtained.
And the particle diameter of the expanded graphite in the obtained heat conductive sheet and the heat conductivity of the heat conductive sheet were calculated. The results are shown in Table 1.
（実施例２）
　工程（Ｂ）において、メッシュ目開きが１５０μｍ、２５０μｍ、および５００μｍのふるいを用いて分級することにより、それぞれ複合粒子群Ａ（目開き５００μｍのふるい上）、複合粒子群Ｂ（目開き１５０μｍのふるい下）、その他の複合粒子群Ｃ（目開き１５０μｍのふるい上および２５０μｍのふるい下）、および、その他の複合粒子群Ｄ（目開き２５０μｍのふるい上および５００μｍのふるい下）の４つの複合粒子群を得た。
　また、工程（Ｃ）において、得られた４つの複合粒子群のうち、複合粒子群Ａおよび複合粒子Ｂを除去し、その他の複合粒子群Ｃおよびその他の複合粒子群Ｄを採用した。そして、当該２つの複合粒子群に含まれている複合粒子を質量比１：１で混合することにより加圧用複合粒子を得た。
　上記以外は実施例１と同様にして、混練物、複合粒子、複合粒子群、加圧用複合粒子、複合材料シート、および熱伝導シートを製造した。そして、実施例１と同様にして測定、算出、または評価した。結果を表１に示す。 (Example 2)
In step (B), classification is performed using sieves having mesh openings of 150 μm, 250 μm, and 500 μm, so that composite particle group A (on a sieve having an opening of 500 μm) and composite particle group B (a sieve having an opening of 150 μm) are obtained. Lower), four composite particle groups of other composite particle group C (upper and 150 μm sieve openings) and other composite particle group D (up and 250 μm sieve openings) Got.
In step (C), among the obtained four composite particle groups, composite particle group A and composite particle B were removed, and other composite particle group C and other composite particle group D were employed. And the composite particle for pressurization was obtained by mixing the composite particle contained in the said 2 composite particle group by mass ratio 1: 1.
Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
（実施例３）
　工程（Ｂ）において、メッシュ目開きが２５０μｍ、および５００μｍのふるいを用いて分級することにより、それぞれ複合粒子群Ａ（目開き５００μｍのふるい上）、複合粒子群Ｂ（目開き２５０μｍのふるい下）、およびその他の複合粒子群（目開き２５０μｍのふるい上および５００μｍのふるい下）の３つの複合粒子群を得た。
　また、工程（Ｃ）において、得られた３つの複合粒子群のうち、複合粒子群Ａおよび複合粒子Ｂを除去し、上記その他の複合粒子群に含まれている複合粒子のみをそのまま採用して加圧用複合粒子を得た。
　上記以外は実施例１と同様にして、混練物、複合粒子、複合粒子群、加圧用複合粒子、複合材料シート、および熱伝導シートを製造した。そして、実施例１と同様にして測定、算出、または評価した。結果を表１に示す。 (Example 3)
In the step (B), classification is performed using a sieve having mesh openings of 250 μm and 500 μm, so that composite particle group A (on a sieve having an opening of 500 μm) and composite particle group B (under a sieve having an opening of 250 μm), respectively. , And other composite particle groups (upper sieve having a sieve opening of 250 μm and lower sieve of 500 μm) were obtained.
Further, in the step (C), among the obtained three composite particle groups, the composite particle group A and the composite particle B are removed, and only the composite particles contained in the other composite particle groups are employed as they are. Composite particles for pressurization were obtained.
Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
（比較例１）
　工程（Ｂ）および工程（Ｃ）を行わず、粉砕段階後に得られた（即ち、分級を行っていない）複合粒子をそのまま採用することにより、加圧用複合粒子を得た。
　上記以外は実施例１と同様にして、混練物、複合粒子、加圧用複合粒子、複合材料シート、および熱伝導シートを製造した。
　そして、実施例１と同様にして測定、算出、または評価した。結果を表１に示す。 (Comparative Example 1)
The composite particles for pressurization were obtained by directly adopting the composite particles obtained after the pulverization stage (that is, not classified) without performing the steps (B) and (C).
Except for the above, a kneaded product, composite particles, composite particles for pressurization, a composite material sheet, and a heat conductive sheet were produced in the same manner as in Example 1.
Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
（比較例２）
　工程（Ｂ）において、メッシュ目開きが５００μｍのふるいを用いて分級することにより、それぞれ複合粒子群Ａ（目開き５００μｍのふるい上）、および複合粒子群Ｂ（目開き５００μｍのふるい下）の２つの複合粒子群を得た。
　また、工程（Ｃ）において、得られた２つの複合粒子群のうち、複合粒子群Ｂを除去し、複合粒子群Ａに含まれている複合粒子のみを採用して加圧用複合粒子を得た。
　上記以外は実施例１と同様に、混練物、複合粒子、複合粒子群、加圧用複合粒子、複合材料シート、および熱伝導シートを製造した。そして、実施例１と同様にして測定、算出、または評価した。結果を表１に示す。 (Comparative Example 2)
In the step (B), by classifying using a sieve having a mesh opening of 500 μm, each of composite particle group A (on a sieve having an opening of 500 μm) and composite particle group B (below a sieve having an opening of 500 μm) Two composite particle groups were obtained.
Further, in step (C), among the obtained two composite particle groups, the composite particle group B was removed, and only the composite particles contained in the composite particle group A were employed to obtain composite particles for pressurization. .
Except for the above, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced in the same manner as in Example 1. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
（比較例３）
　工程（Ｂ）において、メッシュ目開きが１５０μｍ、２５０μｍ、および５００μｍのふるいを用いて分級することにより、それぞれ複合粒子群Ａ（目開き５００μｍのふるい上）、複合粒子群Ｂ（目開き１５０μｍのふるい下）、その他の複合粒子群Ｃ（目開き１５０μｍのふるい上および２５０μｍのふるい下）、および、複合粒子群Ｄ（目開き２５０μｍのふるい上および５００μｍのふるい下）の４つの複合粒子群を得た。
　また、工程（Ｃ）において、得られた４つの複合粒子群のうち、複合粒子群Ｂおよびその他の複合粒子群Ｄを除去し、複合粒子群Ａおよびその他の複合粒子群Ｃを採用した。そして、当該２つの複合粒子群に含まれている複合粒子を質量比１：１で混合することにより加圧用複合粒子を得た。
　上記以外は実施例１と同様にして、混練物、複合粒子、複合粒子群、加圧用複合粒子、複合材料シート、および熱伝導シートを製造した。そして、実施例１と同様にして測定、算出、または評価した。結果を表１に示す。 (Comparative Example 3)
In step (B), classification is performed using sieves having mesh openings of 150 μm, 250 μm, and 500 μm, so that composite particle group A (on a sieve having an opening of 500 μm) and composite particle group B (a sieve having an opening of 150 μm) are obtained. Lower), four composite particle groups of other composite particle group C (upper sieve of 150 μm opening and under 250 μm sieve) and composite particle group D (upper sieve of 250 μm opening and under 500 μm sieve) are obtained. It was.
Further, in the step (C), among the obtained four composite particle groups, the composite particle group B and the other composite particle group D were removed, and the composite particle group A and the other composite particle group C were adopted. And the composite particle for pressurization was obtained by mixing the composite particle contained in the said 2 composite particle group by mass ratio 1: 1.
Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
（比較例４）
　工程（Ｂ）において、メッシュ目開きが２５０μｍ、および５００μｍのふるいを用いて分級することにより、それぞれ複合粒子群Ａ（目開き５００μｍのふるい上）、その他の複合粒子群（目開き２５０μｍのふるい上および５００μｍのふるい下）、および、複合粒子群Ｂ（目開き２５０μｍのふるい下）の３つの複合粒子群を得た。
　また、工程（Ｃ）において、得られた３つの複合粒子群のうち、複合粒子群Ｂのみを除去し、複合粒子群Ａおよび当該その他の複合粒子群を採用した。そして、当該２つの複合粒子群に含まれている複合粒子を質量比１：１で混合することにより加圧用複合粒子を得た。
　上記以外は実施例１と同様にして、混練物、複合粒子、複合粒子群、加圧用複合粒子、複合材料シート、および熱伝導シートを製造した。そして、実施例１と同様にして測定、算出、または評価した。結果を表１に示す。 (Comparative Example 4)
In the step (B), by classifying using a sieve having a mesh opening of 250 μm and 500 μm, composite particle group A (on a sieve having an opening of 500 μm) and other composite particle groups (on a sieve having an opening of 250 μm) And a composite particle group B of a composite particle group B (under a sieve having an opening of 250 μm) was obtained.
In step (C), only the composite particle group B was removed from the obtained three composite particle groups, and the composite particle group A and the other composite particle groups were employed. And the composite particle for pressurization was obtained by mixing the composite particle contained in the said 2 composite particle group by mass ratio 1: 1.
Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
（比較例５）
　工程（Ｂ）において、メッシュ目開きが１５０μｍ、２５０μｍ、および５００μｍのふるいを用いて分級することにより、それぞれ複合粒子群Ａ（目開き５００μｍのふるい上）、複合粒子群Ｂ（目開き１５０μｍのふるい下）、その他の複合粒子群Ｃ（目開き１５０μｍのふるい上および２５０μｍのふるい下）、および、複合粒子群Ｄ（目開き２５０μｍのふるい上および５００μｍのふるい下）の４つの複合粒子群を得た。
　また、工程（Ｃ）において、得られた４つの複合粒子群のうち、複合粒子群Ｂおよびその他の複合粒子群Ｄを除去し、複合粒子群Ａおよびその他の複合粒子群Ｃを採用した。そして、当該２つの複合粒子群に含まれる複合粒子を、複合粒子群Ａ：複合粒子群Ｃ＝９：１（質量比）で混合することにより加圧用複合粒子を得た。
　上記以外は実施例１と同様にして、混練物、複合粒子、複合粒子群、加圧用複合粒子、複合材料シート、および熱伝導シートを製造した。そして、実施例１と同様にして測定、算出、または評価した。結果を表１に示す。 (Comparative Example 5)
In step (B), classification is performed using sieves having mesh openings of 150 μm, 250 μm, and 500 μm, so that composite particle group A (on a sieve having an opening of 500 μm) and composite particle group B (a sieve having an opening of 150 μm) are obtained. Lower), four composite particle groups of other composite particle group C (upper sieve of 150 μm opening and under 250 μm sieve) and composite particle group D (upper sieve of 250 μm opening and under 500 μm sieve) are obtained. It was.
Further, in the step (C), among the obtained four composite particle groups, the composite particle group B and the other composite particle group D were removed, and the composite particle group A and the other composite particle group C were adopted. And the composite particle for pressurization was obtained by mixing the composite particle contained in the said 2 composite particle group by composite particle group A: composite particle group C = 9: 1 (mass ratio).
Except for the above, in the same manner as in Example 1, a kneaded product, composite particles, composite particle group, composite particles for pressurization, composite material sheet, and heat conductive sheet were produced. Measurement, calculation, or evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１より、加圧用複合粒子の準備工程において工程（Ａ）、（Ｂ）および（Ｃ）の全ての工程を経ることにより、粗大な粒子径を有する複合粒子群Ａを分級・除外した複合粒子群を用いた実施例１～３では、当該分級・除外を行わなかった比較例１に比べ、熱伝導性、強度、および硬度の全てにおいて良好な特性を示した。
　また、加圧用複合粒子の準備工程において工程（Ａ）、（Ｂ）および（Ｃ）の全ての工程を経ることにより、粗大な粒子径を有する複合粒子群Ａを分級・除外した複合粒子群を用いた実施例１～３では、当該除外を行わずに複合粒子群Ａを用いた比較例２～５に比べ、高い熱伝導性と、高い強度および良好な硬度とを並立させることができた。
　従って、本発明の複合材料シートの製造方法／熱伝導シートの製造方法により、優れた熱伝導性、強度、および硬度を並立した複合材料シート／熱伝導シートを提供し得る。 From Table 1, composite particles obtained by classifying / excluding the composite particle group A having a coarse particle diameter by going through all the steps (A), (B) and (C) in the step of preparing the composite particles for pressurization. In Examples 1 to 3 using groups, compared with Comparative Example 1 in which the classification / exclusion was not performed, favorable characteristics were exhibited in all of thermal conductivity, strength, and hardness.
In addition, the composite particle group obtained by classifying and excluding the composite particle group A having a coarse particle diameter by going through all the steps (A), (B) and (C) in the step of preparing the composite particles for pressurization. In Examples 1 to 3 used, high thermal conductivity, high strength and good hardness could be juxtaposed as compared with Comparative Examples 2 to 5 using the composite particle group A without performing the above exclusion. .
Therefore, the composite material sheet / thermal conductive sheet having excellent thermal conductivity, strength, and hardness can be provided by the composite material sheet manufacturing method / thermal conductive sheet manufacturing method of the present invention.
　本発明によれば、高い熱伝導性、高い強度、および良好な硬度を並立させた複合材料シートの製造方法を提供することができる。
　また、本発明によれば、高い熱伝導性、高い強度、および良好な硬度を並立させた熱伝導シートの製造方法を提供することができる。
  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the composite material sheet which paralleled high thermal conductivity, high intensity | strength, and favorable hardness can be provided.
Moreover, according to this invention, the manufacturing method of the heat conductive sheet which made parallel high heat conductivity, high intensity | strength, and favorable hardness can be provided.

Claims (6)

  1. 　加圧用複合粒子を得る加圧用複合粒子の準備工程と、前記加圧用複合粒子を加圧することで複合材料シートを得る加圧工程とを含む複合材料シートの製造方法であって、
    　前記加圧用複合粒子の準備工程が、
    　粒子状炭素材料および樹脂を含有する複合粒子を準備する工程（Ａ）と、
    　準備した前記複合粒子を、最大体積平均粒子径を有する複合粒子群Ａおよび最小体積平均粒子径を有する複合粒子群Ｂを含む少なくとも２つの複合粒子群に分級する工程（Ｂ）と、
    　前記複合粒子群のうち前記複合粒子群Ａ以外の複合粒子群に含まれる複合粒子を用いて前記加圧用複合粒子を準備する工程（Ｃ）と、
    を含む、複合材料シートの製造方法。     A method for producing a composite material sheet, comprising: a step of preparing composite particles for pressurization to obtain composite particles for pressurization; and a pressurization step of obtaining a composite material sheet by pressurizing the composite particles for pressurization,
    The step of preparing the composite particles for pressurization includes:
    Preparing a composite particle containing a particulate carbon material and a resin (A);
    Classifying the prepared composite particles into at least two composite particle groups including a composite particle group A having a maximum volume average particle diameter and a composite particle group B having a minimum volume average particle diameter (B);
    (C) preparing the pressurizing composite particles using composite particles contained in a composite particle group other than the composite particle group A among the composite particle groups;
    A method for producing a composite material sheet, comprising:
  2. 　前記工程（Ｃ）において用いられる複合粒子を含む複合粒子群の体積平均粒子径が５００μｍ以下である、請求項１に記載の複合材料シートの製造方法。 The method for producing a composite material sheet according to claim 1, wherein the volume average particle diameter of the composite particle group containing the composite particles used in the step (C) is 500 µm or less.
  3. 　前記加圧用複合粒子は、粒子径５００μｍ以上の複合粒子の含有率が４０体積％未満である、請求項１または２に記載の複合材料シートの製造方法。 The method for producing a composite material sheet according to claim 1 or 2, wherein the composite particles for pressurization have a content of composite particles having a particle diameter of 500 µm or more of less than 40% by volume.
  4. 　前記複合粒子が、前記粒子状炭素材料１００質量部に対して前記樹脂を５０質量部以上１５０質量部以下含有する、請求項１～３のいずれか１項に記載の複合材料シートの製造方法。 The method for producing a composite material sheet according to any one of claims 1 to 3, wherein the composite particles contain 50 parts by mass or more and 150 parts by mass or less of the resin with respect to 100 parts by mass of the particulate carbon material.
  5. 　前記工程（Ａ）が、前記粒子状炭素材料および前記樹脂を混練して混練物を得る混練段階と、前記混練物を粉砕して前記複合粒子を得る粉砕段階とを含む、請求項１～４のいずれか１項に記載の複合材料シートの製造方法。 The step (A) includes a kneading step of kneading the particulate carbon material and the resin to obtain a kneaded product, and a pulverizing step of crushing the kneaded product to obtain the composite particles. The manufacturing method of the composite material sheet of any one of these.
  6. 　請求項１～５のいずれか１項に記載の製造方法で得られた前記複合材料シートを厚み方向に複数枚積層して、或いは、請求項１～５のいずれか１項に記載の製造方法で得られた前記複合材料シートを折畳または捲回して、積層体を得る工程と、
    　前記積層体を、積層方向に対して４５°以下の角度でスライスし、熱伝導シートを得るスライス工程と、
    を含む、熱伝導シートの製造方法。     The manufacturing method according to any one of claims 1 to 5, wherein a plurality of the composite material sheets obtained by the manufacturing method according to any one of claims 1 to 5 are laminated in the thickness direction, or the manufacturing method according to any one of claims 1 to 5. Folding or winding the composite material sheet obtained in step to obtain a laminate;
    Slicing the laminate at an angle of 45 ° or less with respect to the lamination direction to obtain a heat conductive sheet;
    The manufacturing method of the heat conductive sheet containing this.
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