WO2018061830A1 - Procédé de production d'article moulé en graphite - Google Patents

Procédé de production d'article moulé en graphite Download PDF

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Publication number
WO2018061830A1
WO2018061830A1 PCT/JP2017/033495 JP2017033495W WO2018061830A1 WO 2018061830 A1 WO2018061830 A1 WO 2018061830A1 JP 2017033495 W JP2017033495 W JP 2017033495W WO 2018061830 A1 WO2018061830 A1 WO 2018061830A1
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graphite
graphene oxide
sheet
molded body
producing
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PCT/JP2017/033495
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English (en)
Japanese (ja)
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祥 大澤
幸仁 中澤
宏佳 木内
寛人 伊藤
北　弘志
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コニカミノルタ株式会社
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Publication of WO2018061830A1 publication Critical patent/WO2018061830A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/182—Graphene
    • C01B32/198—Graphene oxide
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/20—Graphite
    • C01B32/205—Preparation

Definitions

  • the present invention relates to a method for producing a graphite molded body, and more particularly, to a method for producing a graphite molded body for efficiently producing a graphite molded body having high thermal conductivity.
  • Graphite contains real hydrogen having a structure in which carbon atoms are stacked in a two-dimensional network molecule (graphene) with a thickness of 1 atom in which hexagonal lattices are formed by covalent bonds of sp 2 hybrid orbitals. There are no or few crystals.
  • Graphene and graphite have unique properties such as electrical conductivity due to ⁇ electrons existing in the plane, high thermal conductivity derived from covalent crystals in which light carbon atoms are firmly bonded to each other, and high elastic modulus in the in-plane direction.
  • a processed molded body having physical properties derived from covalent crystals in the in-plane direction of the graphite is very valuable in industry.
  • An isotropic graphite compact is well known as a processed graphite compact.
  • Isotropic graphite molded bodies are manufactured from coke of petroleum and coal raw materials. Powders obtained by pulverizing raw coke and coal tar pitch obtained as a by-product during coke production are combined as a binder. A pulverized material of several tens to several hundreds ⁇ m called a kneaded product is used as a forming raw material.
  • This molding raw material can be molded by cold isostatic pressing (CIP), extrusion molding, mold molding, etc. to obtain a molded product, and then the molded product is sintered at a temperature around 1000 ° C. Then, the coke and the binder are integrated while the volatile components are evaporated.
  • CIP cold isostatic pressing
  • An isotropic graphite molded body can be obtained by performing calcination and crystallization at a temperature in the vicinity of ° C.
  • an isotropic graphite molded body composed of graphite can be obtained, but this is because only coke powder having a small anisotropy is simply spread when making a molded product.
  • Each graphite crystal inside the finished compact is oriented in various directions and becomes isotropic when the compact is viewed macroscopically and is therefore referred to as “isotropic” graphite.
  • a certain degree of anisotropy can be produced by extrusion molding or mold molding, but it is far from the state in which graphite crystals are regularly arranged.
  • isotropic graphite is greatly reflected in the properties of graphite crystals with anisotropy, in which covalent bonds are formed in a network form in the direction of the graphene plane and laminated by van der Waals force in the direction perpendicular to the graphene plane. I don't mean.
  • the thermal conductivity which is a physical property that greatly depends on the crystal structure, is as high as about 2000 W / (m ⁇ K) for a graphite single crystal, whereas isotropic graphite has several hundred W / ( m ⁇ K).
  • a graphite compact having highly oriented graphite crystals there is highly oriented pyrolytic graphite that can be produced from a polymer.
  • Highly oriented pyrolytic graphite produced from a polymer compared to isotropic graphite produced by simply pulverizing a raw material and carbonizing and graphitizing it, is made from a polymer film whose orientation is controlled, such as polyimide, as a raw material.
  • a highly oriented graphite molded body can be produced.
  • graphite is highly oriented in the in-plane direction, and its thermal conductivity approaches the performance of single crystal graphite.
  • the conventional graphite molded body can be molded relatively freely, but the isotropic graphite that does not sufficiently bring out the physical properties derived from the graphite crystal structure and the high-orientation raw material polymer It is difficult to control the initial orientation, and highly oriented pyrolytic graphite, which cannot be freely molded, has become the mainstream.
  • graphite crystals are constructed from graphene molecules that make up graphite, and highly oriented graphite compacts can be produced, there are many steps to use petroleum and coal raw materials with many impurities.
  • Graphene is a layered compound that is ideally separated from graphite one by one.
  • the graphene particles including one to several tens of layers are referred to as graphene particles. Since mere graphene particles have no affinity for solvents and the like, they can be dispersed only at a very low concentration without a dispersant, and the dispersibility in solvents is extremely low. An amount of solvent is required and is not practical. If the solvent to be used is reduced, the graphene particles are agglomerated quickly, resulting in an agglomerated material in which the orientation is significantly deteriorated. Also, if a large amount of dispersant is used, they naturally become impurities, and it is not possible to exhibit the performance specific to graphite.
  • graphene oxide is one of the most promising graphene materials for producing a graphite molded body from graphene molecules.
  • Graphene oxide imparts a hydrophilic oxygen-containing group such as a hydroxy group, an epoxy group, a carbonyl group, or a carboxy group in the plane of graphene, so that the dispersibility in water and some organic solvents is remarkably improved. For this reason, graphene oxide can be dispersed in a solvent in a state of being laminated from a single molecular layer to several tens of layers without using a dispersant that can be an impurity when producing a graphite crystal.
  • a molded product can be produced by molding this graphene oxide dispersion and removing the solvent.
  • the thickness of the dispersed graphene oxide particles is 1 nm or less to several nm
  • the diameter in the in-plane direction of the graphene oxide is several ⁇ m
  • the aspect ratio of the particle diameter in the thickness direction to the in-plane direction is Since it reaches 10,000, it can be laminated in the thickness direction, and a molded product having excellent orientation can be obtained by removing the solvent.
  • Non-Patent Document 1 heat treatment is performed at 1600 to 2850 ° C. for 30 minutes for reduction and crystallization.
  • the produced graphite has the highest thermal conductivity of 1434 W / (m ⁇ K), the same level as the highly oriented pyrolytic graphite, and a highly oriented graphite compact can be produced.
  • the graphite compact actually produced from this graphene oxide is similar to the highly oriented pyrolytic graphite produced from the same highly oriented graphite compact.
  • the heat treatment at around 3000 ° C. is performed from the outside, and it is still a manufacturing method with a large industrial load.
  • the present invention has been made in view of the above-described problems and situations, and its solution is to provide a method for producing a graphite molded body that efficiently produces a graphite molded body having high thermal conductivity from graphene oxide. is there.
  • the present inventor in the process of examining the cause of the above-mentioned problem, makes the heating method a resistance heating method by energization and further increases the pressure from graphene oxide by using a manufacturing method having a pressurizing step.
  • the inventors have found that an oriented graphite molded body can be produced efficiently and have reached the present invention.
  • a method for producing a graphite molded body using graphene oxide as a raw material comprising a step of resistance heating by energization and a step of pressing.
  • the orientation of the graphite crystal is further increased. It is considered that the thermal conductivity of the formed graphite compact can be significantly increased because the graphite density can be increased and the density of graphite can be increased.
  • the method for producing a graphite molded body of the present invention is a method for producing a graphite molded body using graphene oxide as a raw material, and includes a resistance heating step by energization and a pressurizing step. This feature is a technical feature common to or corresponding to the claimed invention.
  • the step of resistance heating by energization and the step of pressurization are performed simultaneously.
  • the process of resistance heating by the said electricity supply and the said pressurization process are performed separately.
  • the pressure applied to the graphene oxide in the pressurizing step is preferably 50 MPa or more, and more preferably 100 MPa or more. Thereby, the effect which improves the orientation of a graphite crystal is acquired.
  • the thermal conductivity of the graphite compact is preferably 1000 W / (m ⁇ K) or more, and more preferably 1500 W / (m ⁇ K) or more.
  • the graphite compact is preferably a graphite sheet.
  • ⁇ is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
  • the method for producing a graphite molded body of the present invention is a method for producing a graphite molded body using graphene oxide as a raw material, and includes a step of resistance heating by energization and a step of pressing.
  • the graphene oxide may be formed into a desired shape.
  • a graphene oxide solvent dispersion in which graphene oxide prepared by oxidizing graphite with a strong oxidizing agent is dispersed in a solvent is prepared, and then the graphene oxide solvent dispersion is molded using a mold having a desired shape, and then the solvent By removing the graphene, a graphene oxide molded product can be produced.
  • a graphite molded body having a high thermal conductivity can be produced in a short time and in a simple manner through a process of resistance heating by energization and a process of pressurization.
  • graphene oxide refers to graphene modified with an oxygen-containing group such as a carboxy group, a carbonyl group, a hydroxy group, and an epoxy group.
  • the graphene oxide used in the present invention is not particularly limited, but the oxygen content ratio (atomic%) of graphene oxide having an oxygen-containing group such as a carboxy group, a carbonyl group, a hydroxy group, or an epoxy group is in the range of 24 to 50 atomic%. It is preferable to be within.
  • the oxygen content ratio (atomic%) of graphene oxide can be measured by X-ray photoelectron spectroscopy (hereinafter also referred to as XPS), and is represented by O / (C + O) atomic%. It is.
  • XPS X-ray photoelectron spectroscopy
  • the oxygen content ratio of graphene oxide can be measured using a Quantera SXM manufactured by ULVAC-PHI CORPORATION.
  • a monochromatic Al—K ⁇ ray is used as an X-ray source, and the spectroscope has a half-width of 0.5 eV or less when the Ag3d 5/2 peak of purified silver is measured.
  • Graphene oxide is a layered particle in which graphene constituting graphite is peeled off and oxidized by oxidizing graphite.
  • a larger diameter in the plane direction of the layered particle is preferable from the viewpoint of physical properties such as electrical conductivity, thermal conductivity, elastic modulus and strength.
  • the diameter in the plane direction of the layer is preferably 1 ⁇ m or more, more preferably 5 ⁇ m or more, and further preferably 10 ⁇ m or more as long as no trouble occurs in the dispersion state of the graphene oxide solvent dispersion.
  • Graphene oxide is a layered particle in which graphene constituting graphite is exfoliated and oxidized by oxidizing graphite, and its thickness is about 0.34 nm to several nm, and all of them are exfoliated to a single layer. There is no need, and depending on the application, a dispersed state of several to several tens of layers may be used as long as the orientation is not hindered.
  • Graphene oxide is obtained by oxidizing graphite or multilayer graphene with a strong oxidizing agent to give oxygen-containing groups such as epoxy groups, hydroxy groups, carbonyl groups, and carboxy groups to the surface and edges of graphene particles, and to the solvent. Can be dispersed. It is well dispersed in water, and organic solvents are compatible with solvents with hydrophilic groups, such as methanol, ethanol, tetrahydrofuran (THF), etc., and do not interfere with moldability and orientation depending on the application. Thus, the dispersion can be prepared with other organic solvents such as acetone, methyl ethyl ketone (MEK), and dichloromethane.
  • MEK methyl ethyl ketone
  • the graphene oxide solvent dispersion is a Hummers method or a modified modified version thereof.
  • the Hummers method can be used based on known literature.
  • Known documents for producing graphene oxide include W.W. S. Hummers. , Journal of American Chemistry (1958) 1339, M .; Hirata. , Carbon 42 (2004) 2929, and the like.
  • graphene oxide moldings By removing the solvent from the graphene oxide dispersion, graphene oxide molded products having various shapes can be produced.
  • a graphene oxide sheet can be produced by applying to a substrate and removing the solvent.
  • a thin film having a thickness of several nm is also possible.
  • the graphene oxide fiber can be produced by ejecting from a thin tube of the nozzle and removing the solvent.
  • it can also shape
  • the reduction of graphene oxide refers to a reaction in which oxygen-containing groups in graphene oxide are desorbed as water, oxygen, carbon monoxide, carbon dioxide, or carbonic acid.
  • the electrical resistivity decreases.
  • the graphene oxide molded product may be reduced, and the electrical resistivity may be adjusted depending on the application. By adjusting the electrical resistivity, conditions such as the amount of current to flow and the heating temperature can be adjusted in the step of resistance heating by energization.
  • the reduction reaction proceeds at a temperature of about 1000 ° C. or lower, a temperature of about 1000 ° C. or higher, usually 2000 ° C. or higher is required for the crystallization (graphitization) reaction to proceed. That is, the reaction rate of the reduction reaction is very fast compared to the crystallization (graphitization) reaction. For this reason, the reduction reaction may be performed in advance under mild conditions for the purpose of suppressing expansion during energization heating.
  • a conventionally known method for obtaining graphene oxide reduced product from graphene oxide can be used.
  • a method of reducing graphene oxide by heating thermal reduction
  • a method of reducing using a reducing agent such as hydrazine or ascorbic acid chemical reduction
  • a method of reducing graphene oxide by irradiating light photoreduction
  • a method of electrolyzing and reducing graphene oxide in an aqueous electrolyte solution electrolyzing and reducing graphene oxide in an aqueous electrolyte solution.
  • a current can be passed and self-heated by Joule heat generated by the resistance of the graphene oxide.
  • the direction of the flowing current is not particularly limited, and may be a direct current or an alternating current, and may be a steady current or a pulse current.
  • the magnitude of the current and voltage to flow varies depending on the size and resistance of the sheet, but the current is preferably passed so that the graphene oxide is heated to 1000 ° C. or higher, and is heated to 2000 ° C. or higher, more preferably 2500 ° C. or higher. It is preferable to pass an electric current.
  • current density 100000A / m 2 or more preferably 1000000A / m 2 or more, more preferably 10000000A / m 2 or more, and particularly preferably it is preferred to flow a current so that 100000000A / m 2 or more.
  • the current can be passed in a range not exceeding the limit of the current value derived from the electron density of graphite or the vicinity of 3600 ° C., which is the sublimation point of carbon.
  • the thermal conductivity of the formed graphite compact can be greatly increased by combining the step of pressurizing the graphene oxide. This is considered to be because not only high orientation graphite can be obtained by heating, but also pressurization can further enhance the orientation of graphene in the graphite and increase the density of graphite. .
  • Pressurization may be performed simultaneously with energization, or may be performed separately, that is, before or after energization. From the viewpoint of manifesting the effects of the present invention, the pressurization is preferably performed simultaneously with energization or after heating. Furthermore, the pressurization is preferably performed simultaneously with energization.
  • the efficiency of the covalent bond formation between the graphene oxide molecules is improved by energizing the graphene oxide molecules in a state where the graphene oxide molecules are pressure-bonded by pressure.
  • pressurization before energization can improve the adhesion between graphene oxide molecules and increase the efficiency of forming covalent bonds between graphene oxide molecules.
  • pressure after energization the orientation of graphene oxide molecules can be remarkably improved, and physical properties peculiar to highly oriented graphite can be expressed.
  • the pressurizing device may be added by surface contact using a press or the like, or may be sandwiched between rolls and added by line contact. If a desired pressure is applied, the shape is not limited. Moreover, the pressurizing direction may be applied uniaxially or from all directions.
  • the pressure applied to the graphene oxide in the pressurizing step is preferably 1 MPa or more, more preferably 10 MPa or more, further preferably 50 MPa or more, and particularly preferably 100 MPa or more.
  • the upper limit of the applied pressure is about 1000 MPa in the capacity of a general-purpose press device.
  • the energization time in the step of resistance heating by energization is preferably 60 seconds or less, more preferably 10 seconds or less, from the viewpoint of producing a graphite molded body in a short time. More preferably, it is less than a second.
  • the lower limit of the energization time may be a short current application such as a pulse as long as the crystallinity of graphite is improved and there is no hindrance to the performance characteristic of graphite.
  • a discharge plasma sintering apparatus may be used as a general-purpose apparatus capable of performing energization and pressurization simultaneously.
  • electrodes can be arranged on the upper and lower sides of the compact and pressure can be applied while energizing.
  • a sheet-like material can be sandwiched between electrodes, and pressure can be applied while flowing current in the thickness direction to cause self-heating. If the sheets are stacked and energized and pressed, a thick film sheet or a block body in which the sheets are pressure-bonded and bonded can be easily produced.
  • a cold isostatic pressurizing device (CIP) or a hot isostatic pressurizing device (HIP) may be used as a device that can apply pressure in all directions before or after energization heating. Since pressure can be applied from all directions, it is effective for improving the orientation of the molded body.
  • crystallization of graphene oxide can be promoted and graphitization can be promoted by self-heating and pressurization by Joule heat.
  • Graphitization means repairing the sp 2 covalent bond of graphene oxide, which was broken by an oxygen-containing group, making the layer spacing between graphenes 0.34 nm, which is the same as that of graphite crystals, and improving the orientation. It is.
  • physical properties close to those of a graphite single crystal can be expressed in the molded body.
  • Conventionally for example, compared with the case where a sheet-like highly oriented graphite is produced by externally heating polyimide, for example, it can be produced in a much shorter time, that is, efficiently.
  • the graphite molded body can be manufactured by a manufacturing method including a step of resistance-heating a graphene oxide molded product molded into a desired shape by energization and a step of pressing.
  • the shape can be preferably applied to a sheet shape, a fiber shape, a housing shape, a thin film shape, and the like.
  • a graphite sheet is mentioned as a sheet-like molded object.
  • Graphite is a structure in which a plurality of graphenes are stacked, and the layers are bonded together by a weak van der Waals force.
  • Graphene is a one-atom-thick two-dimensional network compound formed by covalently bonding carbon atoms in a hexagonal lattice. Strictly speaking, graphite is composed of only sp 2 carbon atoms, but actually has defects such as sp 3 carbon atoms, vacancies, and hetero atoms, and those containing these defects are also called graphite.
  • the graphite sheet represents a sheet-like object composed of graphite.
  • Thermal diffusion sheet can be used as a highly oriented graphite sheet.
  • CPU central processing unit
  • the highly oriented graphite sheet has a thermal conductivity that is several times that of copper (401 W / (m ⁇ K)), which exhibits the best performance among general-purpose metals, and has high industrial value.
  • the manufacturing method of the graphite sheet currently widely used industrially is only the highly oriented pyrolytic graphite produced from the polyimide described above, and still uses a process with a large industrial load. If the manufacturing method of this invention is used, a highly heat conductive graphite sheet can be produced cheaply and it is very valuable industrially.
  • a carbon fiber can be produced by applying the production method of the present invention to a graphene oxide formed into a fiber shape.
  • the conventional carbon fiber manufacturing process is as follows: 1) a process of making a fiber precursor made from a polymer or petroleum raw material flame-resistant / infusible by heat treatment at 200 to 300 ° C., 2) a fiber precursor made flame-resistant There is a carbonization process in which heat treatment is performed at around 1500 ° C, 3) a graphitization process in which the carbonized fiber is heat-treated at a temperature of 2000 ° C to 3000 ° C, and then a surface treatment, a polymer coating, and the like.
  • Carbon fibers made from fiber precursors spun from polyacrylonitrile, which is a conventional polymer, or pitch derived from petroleum raw materials, are first gradually heated to be able to withstand high-temperature heat treatment, called flameproofing and infusibilization processes. A process of sintering is required.
  • the precursor is melted if it is suddenly subjected to a high temperature treatment, and therefore, it is sintered over a relatively long time of several tens of minutes in the flameproofing / infusible process.
  • a fiber precursor made of graphene oxide when used, it does not melt like a polymer, so that high-temperature treatment exceeding 2000 ° C. can be performed suddenly.
  • the carbon fiber has no defects in its structure, it becomes a very high-strength material.
  • the carbon fiber breaks brittlely from that point.
  • ⁇ Graphite heat sink> By the method for producing a graphite molded body of the present invention, a heat sink composed of graphite can be efficiently produced. If necessary, a small heat sink or the like can be produced by a 3D printer or the like.
  • a transparent conductive film can be produced by forming a graphene oxide sheet with a nano-order thickness, reducing, and crystallizing.
  • the film surface is disturbed by the generated gas only by energization heating, and a desired highly crystalline transparent conductive film cannot be produced.
  • the currently used transparent conductive film is indium tin oxide (ITO), but there is a strong demand for alternative materials due to the fact that indium is a rare metal.
  • the thin film graphite (graphene) sheet can also be used as a gas barrier sheet.
  • graphene oxide vacancies and the like are generated in the surface due to oxidation reaction, and sp 2 covalent bond is formed by crystallization by current heating according to the present invention, the vacancies are repaired, and the orientation is improved by pressurization.
  • a gas barrier sheet having a very low gas permeability can be efficiently produced.
  • the graphene oxide sheet can be produced by applying a graphene oxide solvent dispersion with a certain thickness and drying the solvent. Any coating method may be used as long as the film quality is not affected as long as it can be applied and dried at a constant thickness. Examples include cast film formation, filtration film formation, dip coating, spin coating, and spray coating. Further, the graphene oxide sheet can be peeled off by applying it to a glass substrate or a resin base material. Any material may be used for the substrate and the substrate as long as the graphene oxide sheet can be peeled off.
  • a graphite sheet can be produced by reducing and crystallizing a graphene oxide sheet using a process of heating by heating and a process of applying pressure.
  • a voltage may be applied while being sandwiched between press machines, and it is sandwiched between two rolls, and by applying voltage to the rolls, pressure is applied by line contact while conveying the thickness direction.
  • An electric current may be passed through.
  • voltage may be applied to both ends of the sample to cause electricity to flow, and pressure may be applied to the energizing portion from the thickness direction using a press and a spacer. It is also possible to prepare another pair of separated rolls while sandwiching and conveying the sheet between the two rolls, applying a voltage between the separated rolls, and conveying the sheet while energizing the sheet in the in-plane direction. It is also possible to apply pressure to the energizing portion using another pair of rolls while energizing the sheet in the in-plane direction.
  • the pressure may be applied simultaneously with energization, or may be performed separately, that is, before or after energization.
  • Thermal conductivity (W / (m ⁇ K)) is represented by the product of thermal diffusivity (m 2 / s), specific heat capacity (J / kg ⁇ K), and density (kg / m 3 ). The thermal conductivity can be calculated by measuring the thermal diffusivity, specific heat capacity, and density.
  • ⁇ Thermal conductivity of graphite compact> A general-purpose metal having the highest thermal conductivity is copper, and its thermal conductivity is 401 W / (m ⁇ K). Therefore, the manufacturing method which has the thermal conductivity exceeding copper and produces a graphite molded object simply has industrial value. Furthermore, among the means for providing a graphite molded body having a thermal conductivity of 1000 W / (m ⁇ K) or more, at present, only an externally heated graphite sheet near about 3000 ° C. has been industrialized. A manufacturing method for producing a graphite molded body having a thermal conductivity of 1000 W / (m ⁇ K) or more is very industrially valuable.
  • the performance is close to the thermal conductivity of single crystal graphite, which is particularly valuable in industry.
  • the upper limit is not particularly limited because the higher the thermal conductivity is, the theoretical value of the thermal conductivity of the graphite single crystal is about 2000 W / (m ⁇ K).
  • the graphite molded body is a graphite sheet because of industrial versatility such as a thermal diffusion sheet.
  • Example 1 ⁇ Preparation of graphene oxide aqueous dispersion 1> 10 g of graphene nanoplatelets (thickness 6-8 nm, width 5 ⁇ m) of Tokyo Chemical Industry Co., Ltd. and 7.5 g of sodium nitrate were placed in a flask, and 621 g of concentrated sulfuric acid was added thereto. The flask was placed in an ice bath and 45 g of potassium permanganate was added in small portions while stirring so that the solution temperature did not exceed 20 ° C. Then, after returning to room temperature and stirring for 14 days, 1 L of 5 mass% sulfuric acid was added there, and it stirred for 1 hour.
  • the graphene oxide aqueous dispersion 1 was applied on a 25 ⁇ m PET (polyethylene terephthalate) film adhered to a glass substrate with an applicator adjusted to a gap of 1.5 mm. After drying at 50 ° C. for 10 hours, the film was peeled from the PET film to obtain graphene oxide sheet 1 (thickness: 44 ⁇ m).
  • the oxygen content ratio of the graphene oxide sheet 1 was 49 atomic%. The oxygen content ratio (atomic%) was measured by XPS described above.
  • thermal conductivity was represented by the following formula, and was calculated by measuring the thermal diffusivity, specific heat capacity, and density.
  • Thermal conductivity thermal diffusivity ⁇ specific heat capacity ⁇ density
  • the thermal diffusivity is Laser Pit of Advance Riko Co., Ltd.
  • the specific heat capacity is a differential scanning calorimeter (DSC 6220: manufactured by Hitachi High-Technologies Corporation)
  • the density is a sheet. The mass and volume were measured, and the thermal conductivity at a temperature of 23 ° C. of each of the prepared graphite sheets was calculated. The results are shown in Table 1.
  • the graphite sheet which is the sheet-like graphite molded body of the present invention has a higher thermal conductivity than that of the comparative example, and can be efficiently produced in a short time.
  • the present invention uses a graphene oxide solvent dispersion ability and an orientation ability with a high aspect ratio at the time of molding to produce a highly oriented graphite compact that is very valuable industrially. It is based on the idea that it can be produced efficiently. In order to efficiently produce a highly oriented graphite compact from graphene oxide, a simple electric heating and pressurizing process is essential at first glance. Excellent physical properties can be expressed. It can be said that the present invention is a production method that satisfies all the moldability, orientation and production efficiency of materials necessary for producing a highly oriented graphite compact, and is very valuable industrially. It can be said.
  • the method for producing a graphite molded body of the present invention is a method for producing a graphite molded body using graphene oxide as a raw material, and it is possible to produce a graphite molded body having high thermal conductivity from graphene oxide in a short time and with a simple method. It is possible to provide a method for producing a graphite molded body.

Abstract

La présente invention aborde le problème de la fourniture d'un procédé de production d'article moulé en graphite pour produire efficacement, à partir d'oxyde de graphène, un article moulé en graphite ayant une conductivité thermique élevée. Ce procédé de production d'article moulé en graphite est destiné à produire un article moulé en graphite à l'aide d'oxyde de graphène en tant que matériau de départ, le procédé étant caractérisé par le fait qu'il comprend une étape de chauffage par résistance par application de courant et une étape de pressurisation.
PCT/JP2017/033495 2016-09-30 2017-09-15 Procédé de production d'article moulé en graphite WO2018061830A1 (fr)

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CN113307267A (zh) * 2021-06-24 2021-08-27 中国矿业大学 一种煤基多孔碳的制备方法

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CN112582105B (zh) * 2020-11-24 2022-08-05 西安交通大学 一种高导电且内部连续的石墨烯杂化膜制备方法
WO2024048396A1 (fr) * 2022-08-31 2024-03-07 パナソニックＩｐマネジメント株式会社 Feuille de graphite et sa méthode de production

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CN113307267A (zh) * 2021-06-24 2021-08-27 中国矿业大学 一种煤基多孔碳的制备方法

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