JP2020200210A5 - - Google Patents

Description

A method of producing a graphene sheet composed of a collection of graphene in which flat surfaces of graphene are overlapped and joined, and a method of covering the surface of the graphene sheet with a collection of fine particles of metal or insulating metal oxide.

The present invention breaks the interlayer bonds of graphite crystals forming graphite particles in a container filled with methanol to produce a collection of graphene composed of the basal plane of the graphite crystals. Next, a graphene sheet composed of a collection of graphene in which the flat surfaces of graphene are overlapped and joined is produced on the bottom surface of the container as the shape of the bottom surface. Further, the present invention relates to a method of covering the surface of a graphene sheet with a collection of fine particles of a metal or an insulating metal oxide. Graphene is a single crystal material composed of a collection of carbon atoms that two-dimensionally forms a network structure in which carbon atoms are hexagonal. Further, in the present invention, a group of thin sheet-shaped graphene in which the flat surfaces of graphene are directly overlapped and joined is called a graphene sheet. The graphite particles are the cheapest carbon materials composed of only a single crystal of graphite and 100% of the crystallization of graphite has progressed. When the interlayer bond of the graphite crystals forming the graphite particles is broken, the bottom surface of the graphite crystals is broken. A collection of graphene consisting of is obtained.

In 2004, a physicist at the University of Manchester in the United Kingdom used cellophane tape to tear off a single crystallite from graphite, the basal plane, which two-dimensionally forms a network of hexagonal carbon atoms. For the first time, we succeeded in extracting a planar substance whose thickness is the size of a carbon atom. This new substance was called graphene. The 2010 Nobel Prize in Physics has been awarded for this research result.

Graphene is an extremely thin substance whose thickness corresponds to the size of a carbon atom, and is a completely new carbon material having almost no mass. For this reason, it has physical characteristics that are far from those of conventional substances, and is attracting attention as a material that can be applied to a wide range of applications.
For example, it is the thinnest material with a thickness of 0.332 nm. It also has the widest surface area, with a surface area of 3000 m ^{2 / g per unit mass.} Further, it has a Young's modulus as large as 1020 GPa, and is the most stretchable and bendable material. Moreover, it is the toughest substance having a large shear modulus of 440 GPa. Further, the thermal conductivity is 19.5 W / Cm, which is 4.5 times the thermal conductivity of silver, which has the highest thermal conductivity among metals. Moreover, the current density exceeds 1000 times that of copper. Furthermore, it has electrical conductivity that is only 23 times the specific resistance of copper. Further, the electron mobility is 15000 cm ² / volt / sec, which is an order of magnitude higher than ^{the mobility of silicone of 1400 cm 2 / volt / sec.} Further, it is a single crystal material having a melting point of more than 3000 ° C. and has extremely high heat resistance.

Graphene, on the other hand, is produced in a variety of ways. For example, the aforementioned professor at Manchenster University physically peeled graphene from graphite by hand. In this method, it is difficult to peel off a large amount of graphene in a short time, and the peeled material is not always a single layer of graphite crystals, that is, graphene.
Further, Patent Document 1 describes a method for producing graphene by thermally decomposing a single crystal of silicon carbide. That is, the silicon carbide is heated in an inert atmosphere to thermally decompose the surface. At this time, silicon having a relatively low sublimation temperature is preferentially sublimated, and graphene is produced by the remaining carbon. However, a single crystal of silicon carbide is a very expensive material. Further, silicon is sublimated at a high temperature exceeding 1600 ° C. and in an atmosphere having a high degree of vacuum, but if even a small amount of silicon remains, graphene is not produced as a residue after thermal decomposition. Therefore, the cost of producing a single crystal of silicon carbide and the thermal decomposition treatment of the single crystal becomes very expensive. In addition, producing a large amount of graphene is more expensive.
Further, Patent Document 2 describes a method for producing graphene by bringing a carbon-based substance into contact with a sheet-shaped single crystal graphitized metal catalyst and heat-treating it in a reducing atmosphere. However, this manufacturing method is not an inexpensive manufacturing method, and is not a manufacturing method having excellent mass productivity. First, the production cost of producing a single crystal graphitized metal catalyst is even higher than that of a single crystal of silicon carbide. Second, the method of contacting a single crystal graphitized metal catalyst with a carbon-based substance is inferior in mass productivity. Third, the method of reducing the graphitized metal catalyst in an atmosphere rich in nitrogen gas containing hydrogen gas at a high temperature exceeding 1000 ° C. increases the heat treatment cost. Therefore, producing a large amount of graphene is more expensive.

None of the graphene production methods to date have been, first of all, a method of simultaneously producing a large amount of graphene by an inexpensive production method. Second, the graphene produced is not necessarily graphene. In other words, graphene is a single crystal material consisting of a collection of carbon atoms that two-dimensionally forms a network structure consisting of hexagons of carbon atoms. Graphene is not produced. Furthermore, since the graphene produced is extremely thin and extremely lightweight, it is difficult to confirm that it is graphene.
Therefore, the present inventor has found a method in which all the graphene produced is complete graphene and a large amount of graphene is instantly produced by an extremely simple method (Patent Document 3). That is, it consists of only a single crystal of graphite, the crystallization of graphite progresses 100%, and a mass of natural graphite crystal, which is the cheapest carbon material, is crushed, and scaly graphite particles or scaly graphite particles or scaly graphite crystals are crushed from the crushed graphite crystal. A collection of aggregated graphite particles is selected. The collection of graphite particles is narrowed into the gap between the two parallel plate electrodes, an electric field is applied to the two parallel plate electrodes, and the application of the electric field forms graphite particles. This is a method for producing a large amount of graphene composed of the basal plane of the graphite crystal by simultaneously breaking the interlayer bond of the graphite crystal. ^{According to this production method, a collection of 1.62 × 10 13} graphenes can be instantly obtained from only 1 g of scaly graphite particles or massive graphite particles.

JP-A-2015-110485 JP-A-2009-143799 Patent No. 6166860

As explained in paragraph 3, graphene has amazing physical properties that are completely different from conventional materials, so research and development of various parts and devices using graphene are being carried out. Therefore, if a method of manufacturing a graphene sheet consisting of a group of graphene in which the flat surfaces of graphene are overlapped and joined from a group of graphene manufactured by an inexpensive manufacturing method can be found, an inexpensive part using the graphene sheet or Practical application of devices is progressing. Furthermore, if the surface of the graphene sheet can be covered with a collection of fine particles of metal or insulating metal oxide, the graphene sheet having a conductive or insulating surface can be pressure-bonded to the base material or parts, and the base material can be pressed. And parts can be given the properties of graphene sheets.
On the other hand, a large amount of graphene can be instantly produced by the production method according to Patent Document 3, but a method for producing a graphene sheet has not been found from this collection of graphene. Graphene is an extremely thin substance composed of a single crystallite, which two-dimensionally forms a network structure in which carbon atoms are hexagonal, is extremely lightweight, and has almost no mass. Therefore, graphene produced by simultaneously breaking the interlayer bond of graphite crystals in graphite particles by applying an electric field in Patent Document 3 is extremely easily scattered during and after production. Further, since graphene is extremely thin, it has a flat surface having an extremely large aspect ratio, which is the ratio of the size of the crystal plane to the thickness. Further, since the graphite particles have a certain shape and the shapes of the graphite particles are not the same, the aspect ratio of the graphene produced by breaking the interlayer bond of the graphite crystals in the graphite particles is different for each graphene. Therefore, in the production method in Patent Document 3, the flat surfaces of graphene easily overlap each other during the production of graphene. Moreover, the number of overlapping graphenes is not constant. In addition, it is extremely difficult to distinguish whether or not the flat surfaces overlap each other, and there is no choice but to distinguish by observing with an electron microscope. Further, since graphene in which flat surfaces overlap each other has a weak bonding force between the flat surfaces, when a graphene sheet is manufactured using such a collection of graphene, the graphene sheets are separated at the portion where the flat surfaces overlap. ..
Therefore, there are the following five problems to be solved in manufacturing a graphene sheet in which the flat surfaces of graphene are overlapped and joined.
First, a collection of graphene is produced in a container filled with a liquid with a low viscosity and a low boiling point. As a result, the graphene precipitated in the liquid does not scatter during and after the production of graphene. However, graphene overlaps with each other at the time of manufacture.
Second, the graphene collection is separated into individual graphenes in the container described above. As a result, all graphene comes into contact with the liquid, and in the subsequent treatment, the flat planes of graphene do not directly overlap each other.
Thirdly, the bottom of the container, the flat surfaces of the graphene, the overlap through the liquid. Further, the temperature of the container is raised to the boiling point of the liquid, the liquid is vaporized, and a collection of graphene in which flat surfaces are overlapped is formed on the bottom surface of the container. This makes it possible to manufacture a graphene sheet in which flat surfaces are overlapped and joined.
Fourth, the plane above the graphene cluster is evenly compressed, frictional heat is generated at the site where the flat planes of the graphene overlap, and the flat planes of the graphene are joined by the frictional heat, and the graphene is joined. A graphene sheet composed of a collection of these is formed on the bottom surface of the container in the shape of the bottom surface.
Fifth, the treatments in the above four steps are all extremely simple treatments, and the materials used are general-purpose and inexpensive materials. As a result, a graphene aggregate is produced by an inexpensive production method using an inexpensive graphite particle aggregate, and a graphene sheet is produced by an inexpensive method. As a result, an inexpensive graphene sheet can be produced.
In the production of graphene sheets, the problem solved is the five issues above.
Further, in covering the surface of the graphene sheet with a collection of fine particles of metal or insulating metal oxide, there are the following three problems to be solved.
First, the surface of the graphene sheet formed on the bottom surface of the container as described above is covered with a collection of fine particles made of a metal or an insulating metal oxide. Therefore, the metal or the insulating metal oxide needs to be liquid-phased.
Second, a graphene sheet whose surface is covered with a collection of fine particles made of a metal or an insulating metal oxide can be taken out of the container.
Thirdly, the treatment of covering the surface of the graphene sheet with a collection of fine particles made of a metal or an insulating metal oxide is an extremely simple treatment, and the material used is a general-purpose and inexpensive material.
As a result, the surface of the graphene sheet is covered with a collection of fine particles of metal or insulating metal oxide by an inexpensive method, and the surface of the graphene sheet is covered with fine particles of metal or insulating metal oxide at a low cost. Can be covered with a group of.
In covering the surface of the graphene sheet with a collection of fine particles made of a metal or an insulating metal oxide, the problems to be solved are the above three problems.
The problems to be solved by the present invention are the above eight problems.

A method for producing a graphene sheet consisting of a group of graphene in which flat surfaces of graphene are overlapped and joined is described.
A collection of scaly graphite particles or a collection of massive graphite particles is flatly packed on the surface of one of the two parallel plate electrodes, and the parallel plate electrode is immersed in methanol filled in a container. Further, the other parallel plate electrode is superposed on the one parallel plate electrode, and the two parallel plate electrodes are separated from each other through a collection of the scaly graphite particles or a collection of the massive graphite particles. , The two separated parallel plate electrodes are immersed in the methanol.
Thereafter, applying a voltage of the DC in a gap between the two parallel plate electrodes, thereby, an electric field corresponding to the magnitude of the potential difference divided by the size of the gap of the two parallel plate electrodes , Which is applied to the aggregate of scaly graphite particles or the aggregate of massive graphite particles, and the application of the electric field is sufficient to break the interlayer bond of the base surface made of graphite crystals for all of the graphite particles. Force is simultaneously applied to all π electrons that are responsible for the interlayer bonding of the basal surface forming the graphite particles, thereby all of the interlayer bonding of the basal surface forming the scaly graphite particles or the massive graphite particles. Is destroyed at the same time, and a collection of graphite corresponding to the basal plane is produced in the gap between the two parallel plate electrodes.
After that, the gap between the two parallel plate electrodes is expanded, the two parallel plate electrodes are tilted in the methanol, and vibration accelerations in three directions of left and right, front and back, and up and down are repeatedly applied to the container. , The aggregate of graphene is moved into the methanol through the gap between the two parallel plate electrodes, and then the two parallel plate electrodes are taken out from the container.
Further, the homogenizer device is operated in the methanol in the container, and the impact is repeatedly applied to the graphene aggregate through the methanol to separate the graphene aggregate into individual graphenes in the methanol. After that, the homogenizer device is taken out from the container.
Further, vibration acceleration in three directions of front-back, left-right, and up-down is repeatedly applied to the container, and a group of graphene in which the flat surfaces of the graphene are overlapped with each other via methanol is formed on the bottom surface of the container as the shape of the bottom surface. do,
After that, the temperature of the container is raised to the boiling point of the methanol to vaporize the methanol, and a collection of graphene in which the flat surfaces of the graphene are overlapped is formed on the bottom surface of the container as the shape of the bottom surface.
Thereafter, the upper plane of the collection of graphene evenly compressed, to generate frictional heat in portions flat surfaces of the graphene are overlapped, flat surfaces of the graphene by the frictional heat is joined, the graphene graphene sheet flat faces are made of a collection of the graphene joined overlap each other, wherein is formed on the bottom of the container as the shape of the bottom surface, consisting of a collection of the graphene bonded overlap flat faces of the graphene graphene how to produce a sheet.

In the present invention, the method for producing a graphene sheet composed of a collection of graphene in which the flat surfaces of graphene are overlapped and joined is composed of the following four steps.
First, graphene aggregates are produced from graphite particle aggregates in methanol. That is, a collection of scaly graphite particles or a collection of massive graphite particles narrowed in the gap between the two parallel plate electrodes is immersed in methanol, which is an insulator, and a DC potential difference between the two parallel plate electrodes. Is applied. As a result, an electric field corresponding to the value obtained by dividing the potential difference by the size of the gap between the two parallel plate electrodes is generated in the electrode gap where a collection of scaly graphite particles or a collection of massive graphite particles exists. This electric field simultaneously applies a Coulomb force sufficient for breaking the interlayer bond of the basal plane made of graphite crystals to all the above-mentioned graphite particles to all the π electrons that are responsible for the interlayer bond of the basal plane. As a result, the π electron is released from the constraint on the π orbit, and all the π electrons are separated from the π orbit and become free electrons. That is, when the Coulomb force acting on the π electron is given to the π electron as a force larger than the interaction of the π orbitals, the π electron is released from the constraint of the π orbital and becomes a free electron. As a result, all the π electrons that are responsible for the interlayer bond of the basal plane do not exist in the π orbital, and for all the graphite particles, all the interlayer bonds of the basal surface made of graphite crystals forming the graphite particles are simultaneously present. It will be destroyed. As a result, a collection of basal planes, that is, a collection of graphene, is instantly produced in the gap between the two parallel plate electrodes. The graphene produced is an intrinsic substance consisting only of graphite crystals without impurities. Since the two parallel plate electrodes are immersed in methanol, the graphene deposited in the gap between the two parallel plate electrodes does not scatter. As a result, the first problem out of the five problems in manufacturing the graphene sheet described in paragraph 7 was solved.
When a potential difference is applied between the two parallel plate electrodes immersed in methanol, which is an insulator, an electric field is generated in the gap between the two parallel plate electrodes. That is, methanol is an insulator having a specific resistance of 3 megaΩ · cm or more and a dielectric constant of 33. Ethanol is also an insulator having a dielectric constant of 24. The electric conductivity of ethanol is 7.5 × ^10-6 S / m, and the electric conductivity of scaly graphite particles is 43.9 S / m. Thus, ethanol, compared to the scaly graphite particles is a conductor, the electric conductivity is 1.7 × 10 ⁷ times lower insulator.
Second, the graphene aggregate is separated into individual graphenes in methanol. That is, the graphene deposited in the narrow gap between the two parallel plate electrodes is separated into individual graphene in methanol because the flat planes overlap each other when the graphene is deposited. Therefore, first, the gap between the two parallel plate electrodes is expanded in methanol, then tilted in methanol, and then vibration acceleration in three directions is applied to the container filled with methanol. This causes a collection of graphene to move into the methanol through the gap between the two parallel plate electrodes. After that, the two parallel plate electrodes are taken out from the container. The homogenizer device is then run in methanol to repeatedly impact the graphene assembly via methanol. On the other hand, the bonding between graphene flat surfaces is simply that the flat surfaces overlap, and the bonding force between the flat surfaces is extremely small. Furthermore, due to the low viscosity and low molecular weight of methanol, the impact applied to methanol is only slightly consumed by the molecular vibrations of methanol, and much of the impact energy is not absorbed and is added to the graphene assembly. When this impact is applied to a portion where the flat surfaces overlap each other, the overlapping flat surfaces are easily separated, and methanol enters the gaps between the separated graphenes. Therefore, when an impact is repeatedly applied to the graphene aggregate, it is separated into individual graphenes in methanol, and the flat surface of the separated graphenes comes into contact with methanol. When an ultrasonic homogenizer device is used, the generation of ultrafine and enormous numbers of bubbles, which are one order of magnitude smaller than the flat surface of graphene, and the disappearance of the bubbles become the vibration cycle of the ultrasonic vibration frequency. Correspondingly, it is continuously repeated in methanol (this phenomenon is called cavitation), and a shock wave when a huge number of bubbles burst is continuously and repeatedly added to the entire group of graphenes via methanol. When a shock wave is applied to a portion where the flat planes overlap each other, the overlapping flat planes are separated, methanol enters the gaps between the separated graphenes, and the graphenes are separated into individual graphenes in a short time. Graphene produced by breaking the interlayer bond between the basal planes of graphite particles is a genuine substance having no impurities and consisting only of graphite crystals. After that, the graphene separated into individual graphenes was also a genuine substance consisting only of graphite crystals without impurities because the treatment in methanol was continued.
As a result, the second problem out of the five problems in manufacturing the graphene sheet described in paragraph 7 was solved. Whether or not the homogenizer could be separated into individual graphenes by operating the homogenizer device can be determined by taking out a plurality of samples from methanol, observing the plurality of samples with an electron microscope, and separating them into individual graphenes. Judge whether or not. From this result, the operating conditions and operating time of the homogenizer device are obtained in advance.
Thirdly, vibration acceleration in three directions of front-back, left-right, and up-down is repeatedly applied to the container, and a group of graphene in which the flat surfaces of graphene are overlapped with each other via methanol is formed on the bottom surface of the container as the shape of the bottom surface. .. In other words, the aspect ratio of graphene is extremely large, and the flat plane of graphene separated into individual graphene is in contact with methanol. Therefore, when vibration acceleration in three directions is applied to the container, graphene is flattened up. Moves in methanol, graphene diffuses over the entire bottom surface of the container, and the flat surfaces overlap with each other via methanol. When the vibration to the container is stopped, a collection of graphene in which the flat surfaces are overlapped with each other via methanol is formed on the bottom surface of the container as the shape of the bottom surface. After that, when the temperature of the container is raised to the boiling point of methanol and the methanol is vaporized, a collection of graphene in which the flat surfaces are overlapped is formed on the bottom surface of the container as the shape of the bottom surface. As a result, the third problem out of the five problems in manufacturing the graphene sheet described in paragraph 7 was solved. The vaporized methanol is recovered by a recovery machine and reused.
Fourth, the plane above the group of graphene formed on the bottom surface of the container is evenly compressed, frictional heat is generated at the portion where the flat planes of graphene overlap each other, and the flat planes of graphene are separated by the frictional heat. joined, the graphene sheet formed of a collection of the graphene bonded overlap flat faces of the graphene, formed on the bottom surface of the container as the shape of the bottom surface. That is, graphene has a breaking strength of 42 N / m, which is 100 times or more stronger than that of steel. Therefore, even if a large load is applied to the plane above the group of graphene formed on the bottom surface of the container, the flat plane of graphene is neither deformed nor destroyed. Therefore, evenly compressing the plane above the graphene cluster formed on the bottom of the container does not reduce the applied compressive stress, but applies compressive stress to the overlapping flat planes of the graphene. , Friction heat is generated, and the graphene flat surfaces are joined to each other by the frictional heat, and a graphene sheet composed of a collection of the graphenes in which the graphene flat surfaces are overlapped and joined is formed on the bottom surface of the container as the shape of the bottom surface. Will be done. As described above, graphene is an intrinsic substance having no impurities and consisting only of graphite crystals. Since the flat surfaces of graphene are joined by frictional heat, the flat surfaces of graphene are firmly joined. As a result, the fourth problem out of the five problems in manufacturing the graphene sheet described in paragraph 7 was solved.
In the graphene sheet, since the flat surfaces of graphene are bonded to each other by frictional heat, the graphene is bonded with a constant bonding force. Therefore, if the graphene sheet is formed on the bottom surface of the container and vibration acceleration in three directions of left / right, front / back, and up / down is applied for a short time, the graphene sheet can be taken out from the container. In addition, the graphene sheet taken out can be handled. The vibration acceleration applied to the container is about 0.2 G because the graphene sheet is extremely lightweight.
By the way, methanol used in producing graphene sheets is a general-purpose and inexpensive industrial chemical. Graphite particles are also an inexpensive industrial material. In addition, the above-mentioned four steps consist of extremely simple processes. Therefore, according to this method, when four extremely simple steps are carried out in succession using inexpensive graphite particles and methanol, a graphene sheet in which the flat surfaces of graphene are overlapped and joined is formed on the bottom surface of the container. It is formed as the sluggish shape. As a result, the fifth problem out of the five problems in manufacturing the graphene sheet described in paragraph 7 was solved, and all the problems were solved.
The graphene sheet produced by the production method described above brings about the following effects.
First, graphene has a thickness of 0.332 nm, which corresponds to the size of a carbon atom, is extremely lightweight, and has almost no mass. Moreover, since the thickness is extremely thin, the presence of graphene cannot be visually confirmed. Therefore, it is difficult to handle graphene one by one. On the other hand, the graphene sheet in which graphenes are joined to each other via a flat surface has a certain area and a certain thickness, so that each graphene sheet can be handled. Since this graphene sheet is composed only of graphene, it has the properties of graphene. Further, the graphene sheet is an inexpensive industrial material that can be manufactured by an inexpensive method using an inexpensive material. Therefore, application to various industrial products using graphene sheet will be pioneered.
Secondly, a graphene sheet having the shape of the bottom surface is manufactured on the bottom surface of the container. Therefore, a graphene sheet having a thickness of submicron can be manufactured, and the shape and area of the graphene sheet can be freely changed according to the shape of the bottom surface of the container. For this reason, graphene sheets with excellent both thermal and electrical conductivity have any size, shape, and thickness, including electrodes and contacts with a small area, elongated wiring patterns, and heat conductive sheets with a large area. , It can be freely manufactured as a graphene sheet having the properties of graphene.
Third, the graphene sheet is excellent in both thermal conductivity and electrical conductivity. That is, as described above, graphene has both thermal conductivity equivalent to 4.5 times the thermal conductivity of silver and electrical conductivity corresponding to only 23 times the specific resistance of copper. Therefore, the graphene sheet in which the flat surfaces of graphene are joined has both thermal conductivity equivalent to 4.5 times the thermal conductivity of silver and electrical conductivity equivalent to only 23 times the specific resistance of copper. .. As a result, the graphene sheet has better thermal conductivity than silver and has conductivity close to that of metal.
Fourth, since the graphene sheet is free of impurities and is a genuine substance consisting only of graphite crystals, the graphenes are bonded to each other by frictional heat via a flat surface, so that the graphenes are firmly bonded to each other. Further, the gap at which graphenes are joined is narrower than 0.332 nm, which corresponds to the thickness of graphene. Therefore, the substance cannot enter the gap between graphenes. Further, the graphene sheet is composed only of graphene having a melting point of more than 3000 ° C., and the graphene sheet has heat resistance of graphene. Therefore, the graphene sheet does not change over time no matter what environment it is used in. Therefore, the graphene sheet, which has the properties of graphene, is used as an industrial material in various fields.
Here, in the first treatment, the interlayer bond of the basal plane made of graphite crystals forming graphite particles narrowed in the gap between the two parallel plate electrodes by the electric field applied to the gap between the two parallel plate electrodes. However, the phenomenon of being destroyed at the same time will be explained.
The carbon atoms that form graphite crystals in graphite particles have four valence electrons. Three of these valence electrons are the basal plane, that is, the σ electrons that form graphene. These σ electrons covalently bond with the σ electrons of three adjacent carbon atoms on the basal plane at an angle of 120 degrees to form a strong hexagonal network structure two-dimensionally. The remaining one valence electron is a π electron, which exists in a π orbit extending in a direction perpendicular to the basal plane. These π electrons are bonded to the π electrons of adjacent carbon atoms in the vertical direction perpendicular to the basal plane with a weak bonding force, and the basal plane is laminated in layers based on this weak bonding force. That is, the basal plane, that is, graphene, is bonded to each other in layers by the interaction of π orbitals, which is a weak bonding force. Therefore, the graphite particles have a property of being easily peeled off at the basal plane made of graphite crystals, that is, having mechanical anisotropy. This mechanical anisotropy is well known as the lubricity of graphite particles.
When an electric field is applied to these graphite particles, a Coulomb force due to the electric field acts on all π electrons. When the Coulomb force acting on the π electron acts on the π electron as a force larger than the interaction of the π orbit acting on the π electron, the π electron is released from the constraint on the π orbit. As a result, all π electrons move away from the π orbit and become free electrons. As a result, all the π electrons that are responsible for the interlayer bonding of the basal plane disappear from the π orbital, so that all the interlayer bonding of the basal plane is destroyed at the same time. That is, when the π electron moves a distance of the interlayer distance b of the basal plane by the Coulomb force F, the π electron performs work W (W = b · F). This work W is 35 millielectronvolts, which is the magnitude of the interaction of π orbitals per atom acting on π electrons (electron volt is a unit that expresses the magnitude of energy possessed by an electron, and 1 electron volt is 1. ^Beyond (corresponding to 62 × 10-19 joules), the π electron is released from the constraint of the interaction of the π orbit and becomes a free electron. For example, if the gap between the two parallel plate electrodes is separated by 100 μm and a DC potential difference of 10.6 kilovolt or more is applied to the gap between the electrodes, the interlayer bond on the basal plane is instantly broken. As described above, a large amount of graphene can be inexpensively produced by an extremely simple means of applying an electric field to a collection of inexpensive graphite particles. Further, since all the interlayer bonds of the basal plane are broken at the same time, the obtained fine substance is graphene, which is the basal plane made of graphite crystals.
The group of graphite particles referred to here means a group of relatively small amounts of graphite particles of about 1 g to 100 g. That is, the scaly graphite particles or the massive graphite particles are ^{fine particles having a bulk density of 0.2-0.5 g / cm 3} and a particle size of 1-300 microns. Therefore, it is easy to pull the aggregate of graphite particles into the gap between the two parallel plate electrodes, and it is also easy to apply a potential difference to the two parallel plate electrodes. When a potential difference is applied to the gap between the two parallel plate electrodes, an electric field is generated in all the regions where the graphite particles are attracted. This electric field acts on the π electron as a Coulomb force larger than the interaction of the π orbit, and the π electron is released from the constraint on the π orbit and becomes a free electron. As a result, all the interlayer bonds of the basal plane in the graphite particles are simultaneously broken, and a graphene aggregate is produced in the gap between the two parallel plate electrodes.
Here, the number of graphene dispersed in the suspension is calculated by arithmetic. Here, it is assumed that all graphite particles are composed of spheres having a diameter of 25 microns, and since the true density of graphite is 2.25 × 10 ³ kg / m ³ , the weight of one graphite particle is high. Is only 1.84 x ^10-8 g. Assuming that the average thickness of the graphite particles is 10 microns, the interlayer distance is 3.354 angstroms. Therefore, 297,265 graphenes are laminated on the scaly graphite particles having a thickness of 10 microns. .. Therefore, by breaking all the interlayer bonds on the basal plane, a collection of 297,265 graphenes can be obtained from only one spherical graphite particle. Therefore, for an aggregate of only 1 g of spherical graphite particles, an aggregate of 1.62 × 10 ¹³ graphenes can be obtained when all the interlayer bonds on the basal plane are broken. Therefore, according to this production method, an enormous number of graphene aggregates can be obtained from a small amount of graphite particles.

How the grayed La Fen surface of the sheet as described in 8 paragraph, covering silver, copper, gold, or a collection of metal fine particles comprising either metal aluminum,
Silver, copper, gold, or a metal compound or metal aluminum is precipitated by thermal decomposition and dispersed in methanol to create a methanol dispersion, the methanol dispersion, is grayed La Fen sheet described in 8 paragraph The container formed on the bottom surface of the container is filled, and further, vibration acceleration in three directions of left and right, front and back, and up and down is repeatedly applied to the container to bring the surface of the graphene sheet into contact with the methanol dispersion.
After that, the temperature of the container is raised to a temperature at which the metal compound is thermally decomposed, whereby the methanol is first vaporized, and a collection of fine crystals of the metal compound is simultaneously deposited on the surface of the graphene sheet. After that, the fine crystals of the metal compound are thermally decomposed, and a collection of granular metal fine particles made of any metal of silver, copper, gold, or aluminum is deposited all at once on the surface of the graphene sheet. The granular metal fine particles are metal-bonded at a site where they come into contact with each other, and the surface of the graphene sheet is covered with a collection of metal fine particles made of the metal-bonded silver, copper, gold, or aluminum. the surface of the grayed La Fen sheet described in 8 paragraphs, how to cover the silver, copper, gold, or a collection of metal fine particles comprising any metal aluminum.

That is, when the temperature of the container filled with the graphene sheet and the methanol dispersion of the metal compound is raised to a temperature at which the metal compound is thermally decomposed, methanol is first vaporized, and fine crystals of the metal compound are formed on the surface of the graphene sheet. Aggregates are deposited all at once, and aggregates of fine crystals cover the graphene sheet. That is, in the methanol dispersion of a metal compound, the metal compound is dispersed in methanol in a molecular state. Therefore, when methanol is vaporized from the methanol dispersion, a collection of fine crystals of the metal compound is simultaneously gathered on the surface of the graphene sheet. And covers the surface of the graphene sheet. The size of the fine crystals is close to the size of the precipitated fine particles. Next, when the temperature at which the metal compound begins to thermally decompose is reached, the metal compound decomposes into an inorganic substance or an organic substance and a metal. Since the density of the inorganic or organic matter is lower than the density of the metal, the inorganic or organic matter is deposited in the upper layer and the metal is deposited in the lower layer, and the inorganic or organic matter in the upper layer takes away the heat of vaporization and vaporizes. Immediately after the vaporization is completed, 40- A collection of granular metal fine particles made of any metal of silver, copper, gold, or aluminum having a size of 60 nm is deposited all at once on the surface of the graphene sheet, covering the surface of the graphene sheet. Since these metal fine particles have no impurities and are in an active state, they form metal bonds at sites where they come into contact with each other. Therefore, a collection of metal fine particles deposited on the surface of the graphene sheet is metal-bonded at a site where they come into contact with each other, and the collection of metal-bonded metal fine particles covers the surface of the graphene sheet. As the amount of the metal compound dispersed in methanol increases, the amount of metal fine particles precipitated increases, and as a result, the amount of metal fine particles precipitated on the surface of the graphene sheet increases, and a collection of metal-bonded metal fine particles is laminated to form a laminated metal. A collection of fine particles covers the surface of the graphene sheet. As a result, the first of the three problems in covering the surface of the graphene sheet described in paragraph 7 with a collection of metal fine particles was solved. The thermal conductivity and electrical conductivity of metals are superior in the order of silver, copper, gold, and aluminum. Further, all of these metals are soft metals having low hardness.
On the other hand, since the entire surface of the graphene sheet is covered with a collection of metal-bonded metal fine particles, the metal-bonded metal fine particles cover the graphene sheet with a constant bonding force. Further, since the graphenes are bonded to each other by frictional heat via the flat surface of the graphene, the graphene sheet also has a certain bonding force. Therefore, when the graphene sheet is taken out from the container, if vibration accelerations in three directions of front-back, left-right, and up-down are applied to the container for a short time, the graphene sheet is dissociated from the container and the graphene sheet can be taken out from the container. In addition, the graphene sheet taken out can be handled. The vibration acceleration applied to the container is about 0.4 G because the graphene sheet is extremely lightweight.
As a result, the second problem out of the three problems when covering the surface of the graphene sheet described in paragraph 7 with a collection of metal fine particles was solved.
The graphene sheet produced by the production method described above brings about the following effects.
First, a graphene sheet having the shape of the bottom surface is manufactured on the bottom surface of the container. Therefore, a graphene sheet having a thickness of submicron can be manufactured, and the shape and area of the graphene sheet can be freely changed according to the shape of the bottom surface of the container. For this reason, graphene sheets with excellent both thermal and electrical conductivity have any size, shape, and thickness, including electrodes and contacts with a small area, elongated wiring patterns, and heat conductive sheets with a large area. It can be freely manufactured as a graphene sheet.
Secondly, the graphene sheet is excellent in both thermal conductivity and electrical conductivity. That is, as described above, graphene has both thermal conductivity equivalent to 4.5 times the thermal conductivity of silver and electrical conductivity corresponding to only 23 times the specific resistance of copper. Therefore, a graphene sheet covered with a collection of metal fine particles made of any of silver, copper, gold, or aluminum has a relatively high thermal conductivity, that is, it has priority over the flat surface of graphene, which easily conducts heat. Then, heat is transferred, and the electric conductivity is relatively high, that is, the current flows in preference to the collection of metal fine particles in which the current easily flows. As a result, the graphene sheet has better thermal conductivity than silver and has conductivity close to that of metal. The specific resistance of aluminum is 1.6 times that of copper, and aluminum has a higher resistivity than graphene.
Third, the entire surface of the graphene sheet is covered with a collection of metal fine particles made of soft metal of 40-60 nm, the surface has a surface roughness that is an order of magnitude smaller than that of mirror polishing, and the surface is water repellent and stain resistant. Has lubricity properties.
Fourth, since the two planes of the graphene sheet are covered with a collection of metal fine particles, the graphene sheet can be crimped to a part or a base material. In other words, the metal composed of silver, copper, gold, and aluminum, which has excellent both thermal conductivity and electrical conductivity, is a soft metal with low hardness, and when compressive stress is applied to one plane of the graphene sheet, this plane The collection of metal fine particles formed in the above is plastically deformed or elastically deformed to the surface of the part or the base material and bites into or pressure-bonded, and the graphene sheet is pressure-bonded to the part or the base material. Therefore, the graphene sheet can be integrated with the component or the base material by crimping, and both the properties of thermal conductivity and electrical conductivity can be imparted to the component and the base material.
Fifth, metal compounds that precipitate silver, copper, gold, or aluminum by thermal decomposition are general-purpose industrial chemicals, and with extremely simple treatment, the surface of the graphene sheet can be made of silver. It is covered with a collection of fine metal particles made of any of the metals copper, gold, or aluminum. Therefore, using inexpensive materials and at low cost, the flat surfaces of graphene of arbitrary size, shape and thickness are covered with a collection of metal fine particles made of any metal such as silver, copper, gold or aluminum. The broken graphene sheet can be optionally manufactured on the bottom surface of the container.
As a result, of the three problems in covering the surface of the graphene sheet described in paragraph 7 with a collection of metal fine particles, the third problem was solved, and all the problems were solved.

The method of covering the surface of the graphene sheet described in paragraph 10 with a collection of metal fine particles made of any of silver, copper, gold, or aluminum is
A metal complex composed of an inorganic metal compound having a metal complex ion in which a ligand composed of an inorganic ion or an inorganic molecule is coordinated to a metal ion composed of a metal of silver, copper, gold, or aluminum. The silver, copper, gold, or aluminum metal described in paragraph 10 is used as a metal compound that precipitates by thermal decomposition, and the surface of the graphene sheet is coated with silver, copper, gold, or according to the method described in paragraph 10. how covering a collection of metal fine particles comprising any metal aluminum.

That is, when a metal complex composed of an inorganic metal compound having a metal complex ion in which a ligand composed of an inorganic ion or an inorganic molecule is coordinated to a metal ion is heat-treated in a reducing atmosphere, the metal is formed at 180-220 ° C. Precipitate. That is, when the metal complex composed of an inorganic metal compound is heat-treated in a reducing atmosphere, it is decomposed into an inorganic substance and a metal, the inorganic substance takes away heat of vaporization and vaporizes, and the vaporization of the inorganic substance is completed at 180-220 ° C., and the metal precipitates. And finish the thermal decomposition reaction.
That is, among the ions constituting the metal complex, the metal ion located in the center of the molecule is the largest, and the distance between the metal ion and the ligand is the longest. When this metal complex is heat-treated in a reducing atmosphere, the coordination bond portion where the metal ion binds to the ligand is first separated and decomposed into a metal and an inorganic substance. When the temperature rises further, the inorganic substance takes away the heat of vaporization and vaporizes, and when the vaporization of the inorganic substance is completed, the metal precipitates. Since the metal complex composed of such an inorganic metal compound has a small molecular weight, the vaporization of the inorganic substance is completed at 180-220 ° C., and the temperature at which the metal is precipitated is the lowest among the temperatures at which the metal is precipitated by the thermal decomposition of the metal compound. ..
Further, a metal complex ion in which a molecule composed of an inorganic substance or an ion composed of an inorganic substance serves as a ligand and is coordinate-bonded to the metal ion is easier to synthesize than other metal complex ions. As such metal complex ions, ammonia NH ₃ serves as a ligand to coordinate bond to metal ions, and water H ₂ O serves as a ligand to coordinate bond to metal ions. Hydroxometal complex ion, chlorine ion Cl ^{−, in} which the complex ion, hydroxyl group OH ⁻ serves as a ligand and coordinates to the metal ion, or chlorine ion Cl ⁻ and ammonia NH ₃ serve as a ligand and metal ion. There are chlorometal complex ions that are coordinated to. All of these ligands have a small molecular weight. Further, a metal complex composed of an inorganic salt such as a chloride, a sulfate or a nitrate having such a metal complex ion has a small molecular weight of the inorganic salt. Therefore, the vaporization of the inorganic substance is completed in the temperature range of 180-220 ° C., and the metal is precipitated. The temperature at which this metal is precipitated is the lowest among the temperatures at which the metal is precipitated by the thermal decomposition of the metal compound.
Therefore, the method of covering the surface of the graphene sheet described in paragraph 10 with a collection of metal fine particles made of any of silver, copper, gold, or aluminum is a method of thermally decomposing any of silver, copper, gold, or aluminum. As a metal compound that precipitates the metal, an inorganic metal compound in which a ligand composed of an inorganic ion or an inorganic molecule is coordinated and bonded to a metal ion composed of any of silver, copper, gold, or aluminum. The surface of the graphene sheet is covered with silver, copper according to the method described in paragraph 10 in which the surface of the graphene sheet is covered with a collection of metal fine particles made of any of silver, copper, gold, or aluminum. It is a method of covering with a collection of metal fine particles made of any of metal, gold, or aluminum.

The method of covering the surface of the graphene sheet described in paragraph 10 with a collection of metal fine particles made of any of silver, copper, gold, or aluminum is
The first characteristic that the oxygen ion constituting the carboxyl group of the carboxylic acid is covalently bonded to the metal ion made of any metal of silver, copper, gold or aluminum, and the second feature that the carboxylic acid is made of a saturated fatty acid. A metal carboxylate compound having both characteristics is used as a metal compound in which any metal of silver, copper, gold, or aluminum described in paragraph 10 is precipitated by thermal decomposition, and a graphene sheet is used according to the method described in paragraph 10. surface, silver, copper, gold or how to cover a group of metal fine particles comprising any metal aluminum, the.

That is, the metal ion is the most common carboxylic acid metal compound having both the first characteristic that the oxygen ion constituting the carboxyl group of the carboxylic acid is covalently bonded to the metal ion and the second characteristic that the carboxylic acid is composed of a saturated fatty acid. It is a large ion, and the distance between the oxygen ion constituting the carboxyl group and the metal ion is longer than the distance between other ions. When a metal carboxylic acid compound having such molecular structural characteristics is heat-treated in an air atmosphere, when the boiling point of the carboxylic acid is exceeded, the bond portion between the oxygen ion and the metal ion constituting the carboxyl group is first separated, and the carboxylic acid. And metal. When a carboxylic acid is composed of a saturated fatty acid, it does not have an unsaturated structure in which carbon atoms are excessive with respect to hydrogen atoms. Therefore, the structure of the hydrocarbon constituting the carboxylic acid and the molecular weight and number of the carboxylic acid Correspondingly, the carboxylic acid takes away the heat of vaporization and vaporizes, and when the vaporization is completed, the metal precipitates.
Examples of such a metal carboxylate compound include a metal octylate compound, a metal laurate compound, and a metal stearate compound. Since the hydrocarbon has a branched structure, octyl acid has a short chain length and a low boiling point of 228 ° C. Further, the boiling point of carboxylic acid having a linear hydrocarbon structure is lower as the molecular weight of the carboxylic acid is smaller, that is, the shorter the linear chain is, the boiling point of lauric acid is 296 ° C., and the boiling point of stearic acid is. It is 361 ° C. Therefore, these metal carboxylate compounds are thermally decomposed at a temperature of 290-430 ° C. in the atmosphere, depending on the boiling point described above.
The metal carboxylate compound composed of unsaturated fatty acids has an excess of carbon atoms with respect to hydrogen atoms as compared with the metal carboxylate compound composed of saturated fatty acids. Therefore, metal oxides such as copper oleate are thermally decomposed. In the case of, the cuprous oxide Cu ₂ O and the cupric oxide Cu O are precipitated at the same time, and a treatment for reducing the cuprous oxide _{Cu 2 O and the cupric oxide Cu O to copper is required.} In particular, cuprous oxide Cu ₂ O is once oxidized to cupric oxide Cu O in an atmosphere richer in oxygen than in the air atmosphere, and further reduced to copper in a reducing atmosphere, which increases the processing cost.
Further, the metal carboxylate compound is an inexpensive industrial chemical that can be easily synthesized. That is, when a carboxylic acid, which is the most general-purpose organic acid, is reacted with a strong alkali, an alkali metal carboxylate compound is produced, and when the alkali metal carboxylate compound is reacted with an inorganic metal compound, a carboxylic acid composed of various metals is produced. Metal compounds are synthesized. Therefore, it is the cheapest organometallic compound among the organometallic compounds. Therefore, the heat treatment temperature is higher than that of the metal complex composed of the inorganic metal compound described in paragraph 15, but the metal compound is cheaper than the metal complex.
Therefore, the method of covering the surface of the graphene sheet described in paragraph 10 with a collection of metal fine particles made of any of silver, copper, gold, or aluminum is a method of thermally decomposing any of silver, copper, gold, or aluminum. As the metal compound that precipitates the metal, the oxygen ion constituting the carboxyl group of the carboxylic acid is covalently bonded to the metal ion composed of any metal of silver, copper, gold, or aluminum. Using a metal carboxylate compound in which the carboxylic acid has the second characteristic of being a saturated fatty acid, the surface of the graphene sheet described in paragraph 10 is made of metal fine particles made of any of silver, copper, gold, or aluminum. According to the method of covering with a collection of metal particles, the surface of the graphene sheet is covered with a collection of metal fine particles made of any of silver, copper, gold, or aluminum.

The grayed La Fen surface of the sheet as described in 8 paragraph, a method of covering a collection of fine particles made of an insulating metal oxide,
A metal compound in which an insulating metal oxide is precipitated by thermal decomposition is dispersed in methanol to prepare a methanol dispersion, and a graphene sheet prepared by the method described in paragraph 8 is formed on the bottom surface of the container. The container is filled, and further, vibration acceleration in three directions of left and right, front and back, and up and down is repeatedly applied to the container to bring the surface of the graphene sheet into contact with the methanol dispersion.
After that, the temperature of the container is raised to a temperature at which the metal compound is thermally decomposed, whereby the methanol is first vaporized, and a collection of fine crystals of the metal compound is simultaneously deposited on the surface of the graphene sheet. After that, the fine crystals of the metal compound are thermally decomposed, and a collection of the insulating metal oxide fine particles is deposited all at once on the surface of the graphene sheet, and the insulating metal oxide fine particles are deposited. the graphene sheet whose surface is covered with gathered, the is formed on the bottom of the container as the shape of the bottom surface, a grayed La Fen surface of the sheet as described in 8 paragraph, a collection of fine particles made of an insulating metal oxide how covered with.

That is, first, a graphene sheet is formed on the bottom surface of the container as the shape of the bottom surface by the manufacturing method described in paragraph 8. Next, a metal compound in which an insulating metal oxide is precipitated by thermal decomposition is dispersed in methanol, and the methanol dispersion is filled in the container in which a graphene sheet is formed on the bottom surface of the container. The metal compound is dispersed in methanol to form a liquid phase. After that, when vibration acceleration in three directions is repeatedly applied to the container, the surface of the graphene sheet on the bottom surface of the container comes into contact with the methanol dispersion liquid. As described in paragraph 11, since the graphene sheet is present in the container, a vibration acceleration of about 0.4 G is applied. Further, the temperature of the container is raised to a temperature at which the metal compound is thermally decomposed. First, methanol is vaporized, and a collection of fine crystals of the metal compound is deposited all at once at the site of contact with the methanol dispersion of the graphene sheet. That is, since the metal compound is dispersed in methanol in a molecular state in the methanol dispersion of the metal compound, when methanol is vaporized from the methanol dispersion, fine crystals of the metal compound are precipitated all at once. After that, the fine crystals of the metal compound were thermally decomposed, and a collection of fine particles of the insulating metal oxide were simultaneously deposited on the site of the graphene sheet in contact with the methanol dispersion, that is, on the entire surface of the graphene sheet. Fine particles of metal oxide cover the entire surface of the graphene sheet. As a result, the surface of the graphene sheet has the property of an insulating metal oxide. As the amount of the metal compound dispersed in methanol increases, the number of fine particles of the metal oxide that precipitates increases, which increases the number of fine particles of the metal oxide that precipitate on the surface of the graphene sheet, and the fine particles of the metal oxide are laminated. However, the entire surface of the graphene sheet is covered with a collection of laminated metal oxide fine particles.
Among the metal oxides, magnetite Fe ₃ O ₄ (a type of iron oxide, also called triiron tetroxide) exists as a conductive metal oxide and has impurities, or from the composition of chemical quantity theory. _{Metal oxides such as chromium CrO 2} , nickel oxide NiO, zinc oxide ZnO, tin oxide SnO ₂ , and copper oxide CuO are examples of metal oxides whose insulating properties are lowered by containing a component that shifts. Insulating metal oxides other than these metal oxides have high altitudes. For example, the Mohs hardness is 9 for _{aluminum Al 2} O ₃ oxide, 8-8.5 for _{chromium Cr 2} O _{3 oxide, and 7-7.5 for titanium oxide TiO 2} (rutile type). On the other hand, the moth hardness of soft metals having excellent thermal conductivity and electrical conductivity is 2.5 for silver, 2.5-3 for copper, 2.5-3 for gold, and 2 for aluminum, as described above. Lower in altitude than insulating metal oxides. The volume resistivity of aluminum oxide Al ₂ O ₃ is 10 ^14-15 Ω · cm, titanium oxide TiO ₂ is 10 ⁷ Ω · cm, and chromium oxide Cr ₂ O ₃ is 10 ¹² Ω · cm, all of which are insulated. Highly sex. In addition, the metal oxide contains impurities or a component deviating from the stoichiometric composition, so that the insulating property is lowered. The above three types of metal oxides having high insulating properties are metal oxides having high insulating properties that do not contain substances deviating from the stoichiometric composition and do not contain impurities.

The method of covering the surface of the graphene sheet with a collection of fine particles made of an insulating metal oxide described in paragraph 16 is described.
Oxygen ions constituting the carboxyl group of the carboxylic acid serve as a ligand, and the metal carboxylic acid compound coordinated and bonded to the metal ion is a metal compound in which an insulating metal oxide is precipitated by thermal decomposition described in paragraph 16. as used according to the method described in 16 paragraphs, how to cover the surface of the graphene sheets at the collection of fine particles made of an insulating metal oxide.

That is, the oxygen ion constituting the carboxyl group of the carboxylic acid serves as a ligand, and the metal carboxylate compound coordinated to the metal ion precipitates a metal oxide by thermal decomposition. Therefore, the method of covering the surface of the graphene sheet described in paragraph 16 with a collection of fine particles of insulating metal oxide is described above as a metal compound in which the insulating metal oxide is thermally decomposed. When a compound is used and the surface of the graphene sheet is covered with a collection of fine particles of insulating metal oxide according to the method described in paragraph 16, the surface of the graphene sheet becomes electrically insulating. The thermal decomposition temperature of the metal carboxylate compound is the highest at which the metal naphthenate compound thermally decomposes at 330 ° C. Further, since the thermal decomposition of the carboxylic acid metal compound in the atmospheric atmosphere is 30 to 50 ° C. lower than the thermal decomposition in the nitrogen atmosphere, the thermal decomposition in the atmospheric atmosphere requires a low heat treatment cost. Further, the metal carboxylate compound is dispersed in methanol up to nearly 10% by weight.
That is, the oxygen ion constituting the carboxyl group serves as a ligand, and the carboxylic acid metal compound which approaches and coordinates with the metal ion is because the oxygen ion approaches and coordinates with the metal ion which is the largest ion. , The distance between the two becomes shorter. Therefore, the oxygen ion coordinate-bonded to the metal ion has the longest distance from the ion covalently bonded on the opposite side of the metal ion. A metal carboxylate compound having such molecular structural characteristics is bonded to an ion in which an oxygen ion constituting a carboxyl group is covalently bonded on the opposite side of the metal ion when the boiling point of the carboxylic acid constituting the metal carboxylate compound is exceeded. The part is first divided and decomposed into a metal oxide and a carboxylic acid, which are compounds of a metal ion and an oxygen ion. When the temperature is further raised, the carboxylic acid takes away the heat of vaporization and vaporizes, and the metal oxide precipitates immediately after the vaporization of the carboxylic acid is completed. Examples of such a metal carboxylate compound include a metal acetate compound, a metal caprylate oxide, a metal benzoate oxide, and a metal naphthenate oxide.
Since some of the metal acetate oxides precipitate metal oxides that have been amorphized by thermal decomposition and unstable metal oxides, the carboxylic acid metal oxide compound that precipitates metal oxides by thermal decomposition is capryl. A carboxylic acid metal oxide composed of an acid metal oxide, a benzoate metal oxide, and a naphthenate metal oxide is desirable.
In addition, the metal carboxylate compounds are inexpensive industrial chemicals that can be easily synthesized. That is, when a general-purpose carboxylic acid is reacted with a strong alkali, an alkali metal carboxylate compound is produced. After that, when the alkali metal carboxylate compound is reacted with the inorganic metal compound, the metal carboxylate compound is synthesized. The carboxylic acid used as a raw material is an organic acid having a relatively low boiling point among the boiling points of the organic acid, and a metal oxide is precipitated at a low heat treatment temperature of about 330 ° C. in an air atmosphere.
As described above, the method of covering the surface of the graphene sheet described in paragraph 16 with a collection of fine particles of insulating metal oxide is a metal in which the insulating metal oxide described in paragraph 16 is thermally decomposed. As the compound, an oxygen ion constituting the carboxyl group of the carboxylic acid serves as a ligand, and a metal carboxylate compound coordinated to the metal ion is used, and the surface of the graphene sheet is insulated according to the method described in paragraph 16. It is a method of covering with a collection of fine particles made of the metal oxide of.

How to retrieve the grayed La Fen sheet described in 16 paragraphs from the container,
According to the method described in paragraph 16, a graphene sheet whose surface is covered with a collection of fine particles of insulating metal oxide is formed on the bottom surface of the container as the shape of the bottom surface, and a flat surface above the graphene sheet is further formed. Evenly compressed, thereby, in a collection of metal oxide fine particles formed on the surface layers of both planes of the graphene sheet, frictional heat is generated at a portion where the metal oxide fine particles come into contact with each other, and the metal oxide fine particles generate frictional heat. The fine particles of the metal oxide are bonded to each other by frictional heat.
Thereafter, the front and rear to the container, left and right, up and down vibration in three directions acceleration added, retrieving the graphene sheet from the container, how removed from container grayed La Fen sheet described in 16 paragraphs.

That is, when the surface of the graphene sheet produced by the method described in paragraph 16 is covered with a collection of insulating metal oxide fine particles, the graphene is a collection of metal oxide fine particles having no impurities and in an active state. Precipitates on the surface of the sheet. The fine particles of the metal oxide are precipitated by contacting the fine particles with each other, but since the fine particles of the metal oxide do not form a metal bond, the bonding force between the fine particles of the metal oxide is small. Therefore, when the graphene sheet produced by the method described in paragraph 16 is taken out from the container, the fine particles of the metal oxide are easily dissociated from the graphene sheet.
On the other hand, the insulating metal oxide has a high hardness as described in paragraph 17. In addition, the compressive strength is also high. For example, the compressive strength of alumina is 3200 MPa, which is 16 times the tensile strength of copper. Therefore, when the upper plane of the graphene sheet formed on the bottom surface of the container is evenly compressed, the fine particles of the metal oxide formed on the surface layers of both planes of the graphene sheet are not deformed or destroyed, so that they are added. The compressive stress is not reduced, and frictional heat is generated at the portion where the fine particles come into contact with each other. The frictional heat causes the fine particles of metal oxide to join each other. As a result, both planes of the graphene sheet are covered with a collection of fine particles of metal oxide bonded by frictional heat. After that, a vibration acceleration of about 0.2 G is applied to the container in three directions of front-back, left-right, and up-down, and the graphene sheet is taken out from the container.
Since the metal oxide fine particles formed on the side surface of the graphene sheet are in contact with the container, the metal oxide fine particles are dissociated from the side surface of the graphene sheet when the upper flat surface of the graphene sheet is evenly compressed. As for the metal fine particles formed on the side surface, frictional heat is generated at a portion where the metal oxide fine particles come into contact with each other, and the metal oxide fine particles are bonded to each other by the frictional heat. However, since the compressive stress acting on the metal oxide fine particles is not as large as the compressive stress acting on the metal oxide fine particles formed on both planes of the graphene sheet, the bonding force between the metal oxide fine particles is high. It is smaller than the bonding force between the fine particles of the metal oxide formed on both planes of the graphene sheet.
In this graphene sheet, the metal oxide fine particles on the surface layer are bonded to each other by frictional heat, and the collection of the metal oxide fine particles has a certain bonding force. This makes it possible to handle the graphene sheet taken out of the container.
Since both flat surfaces of the graphene sheet are formed with a collection of fine particles of metal oxide bonded by frictional heat, the graphene sheet can be crimped to a base material or a component. That is, when the graphene sheet is placed on the surface of the component or the base material and the flat surface of the graphene sheet is evenly compressed, the fine particles of the metal oxide on one flat surface of the graphene sheet bite into the surface of the part or the base material. As a result, the graphene sheet is crimped to the component or the base material, and the other flat surface of the crimped graphene sheet has insulating properties. As a result, a graphene sheet having excellent thermal conductivity and electrical conductivity and an insulating surface is pressure-bonded to the component or the base material.

It is explanatory drawing which enlarged and represented a part of the side surface of the graphene sheet in which the flat planes of graphene overlapped.

Example 1
This example is an example in which a graphene sheet composed of a collection of graphene in which flat planes of graphene are overlapped and joined is formed on the bottom surface of a container according to the manufacturing method described in paragraph 8.
First, 2 liters of methanol was filled into a container having a bottom surface of 1.2 m × 1.2 m and a shallow bottom.
Next, a parallel plate electrode having an effective area of 1 m × 1 m in which an electric field is generated in the gap between the two parallel plate electrodes is prepared, and the two parallel plate electrodes are superposed with a gap of 100 μm, and this gap is formed. The graphite particles are evenly squeezed into the surface. Assuming that the graphite particles are spheres having a particle size of 25 μm and the average thickness of the graphite particles is 10 μm, the graphite particles are evenly packed in the gap of 100 μm formed by the two parallel plate electrodes. In the case, there are 6.4 × 10 ⁷ graphite particles. When a DC voltage of 10.6 kilovolts or more is applied to this group of graphite particles, the interlayer bond between the basal planes of all the graphite particles is broken at the same time. At this time, ^{an aggregate of 1.9 × 10 13} graphenes was obtained, and the aggregate of graphite particles used was only 1.18 g.
Therefore, 10 g of scaly graphite particles (for example, XD100 manufactured by Ito Graphite Industry Co., Ltd.) were stacked and pulled on the surface of a parallel plate electrode having an effective area of an electrode in which an electric field is generated of 1 m × 1 m. This parallel plate electrode is immersed in a container filled with methanol, and the other parallel plate electrode is superposed on the parallel plate electrode, and the two parallel plate electrodes are separated by a gap of 100 μm. A DC voltage of 12 kilovolts was applied between the electrodes. Next, the gap between the two parallel plate electrodes is expanded, the two parallel plate electrodes are tilted in methanol, and vibration acceleration in three directions consisting of 0.2 G is repeatedly applied to the container, and then the container is used. Two parallel plate electrodes were taken out from. Further, ultrasonic vibration of 20 kHz was applied to the methanol in the container for 2 minutes by an ultrasonic homogenizer device (product LUH300 of Yamato Scientific Co., Ltd.). After that, vibration acceleration in three directions consisting of 0.2 G was repeatedly applied to the container.
Next, the temperature of the container was raised to 65 ° C., and methanol was vaporized. Further, a 1.2 m × 1.2 m aluminum plate is placed on the upper flat surface of the sample formed on the bottom surface of the container, and a 20 kg weight is placed on the aluminum plate so that the upper flat surface of the sample is evenly placed. Compressed. After removing the weight and the aluminum plate, a vibration acceleration of 0.2 G in three directions was applied to the container, and the sample was taken out from the container. An aluminum plate was placed on the sample taken out again, and a weight of 10 kg was placed on the sample, but the state of the sample did not change.
Next, the two planes and sides of the sample were observed and analyzed using an electron microscope. As the electron microscope, an extremely low acceleration voltage SEM manufactured by JFE Techno Research Co., Ltd. was used. This device is capable of observing the surface with an extremely low acceleration voltage from 100 V, and has a feature that the surface of the sample can be directly observed without forming a conductive film on the sample. First, the secondary electron beam between 900 and 1000 volts of the backscattered electron beam from the plane of the sample was taken out and image processed. An extremely thin step was confirmed on the flat surface of the sample. Next, the secondary electron beam between 900 and 1000 volts of the backscattered electron beam from the side surface of the sample was taken out and image processing was performed. Ten layers of extremely thin substances were stacked. Furthermore, as a result of image processing of the energy of the characteristic X-ray and its intensity, it was confirmed that only carbon atoms were present and the sample was a graphene sheet in which the flat planes of graphene overlapped with each other.
In FIG. 1, a part of the side surface of the graphene sheet on which the flat surfaces of graphene overlap each other is enlarged and schematically shown. 1 is graphene.
Even if the graphene sheet was taken out from the container and a weight of 10 kg was placed on the graphene sheet, the graphene sheet was not broken, so that the flat surfaces of the graphene were joined with a constant joining force.

Example 2
This example is an example in which the surface of the graphene sheet formed on the bottom surface of the container in Example 1 is covered with a collection of silver fine particles.
First, a metal compound that precipitates silver by thermal decomposition is dispersed in methanol to prepare a methanol dispersion. As a silver compound, two ammines, which are one of the most easily synthesized silver complex ions, are chlorides of diammine silver ion [Ag (NH ₃ ) ₂ ] ^{+ 1 coordinated to silver ion Ag +.} Using Diammine silver chloride [Ag (NH ₃ ) ₂ ] Cl (for example, a product of Tanaka Kikinzoku Sales Co., Ltd.), 0.1 mol of diammine silver chloride was dispersed in 100 cc of methanol. In Example 1, this methanol dispersion was filled in a container in which a graphene sheet was formed on the bottom surface of the container in the shape of the bottom surface. Next, vibration acceleration in three directions consisting of 0.4 G was repeatedly applied to the container. Further, the container was heated to 180 ° C. in an atmosphere of hydrogen gas and left at 180 ° C. for 5 minutes. After that, vibration acceleration in three directions consisting of 0.4 G was applied to the container again for a short time, and the sample was taken out from the bottom of the container.
Next, the two planes and sides of the sample were observed and analyzed with the electron microscope used in Example 1. First, the secondary electron beam between 900 and 1000 V of the backscattered electron beam was taken out and image processing was performed. Granular particles having a size of 40-60 nm were evenly formed on both the plane and the side surface. Next, the energy between 900 and 1000 V of the reflected electron beam was extracted and image processing was performed, and the difference in material was observed depending on the shade of the image. Since no shade was observed, it was formed from the same substance. Furthermore, the energy of the characteristic X-ray and its intensity were image-processed, and the elements constituting the fine particles were analyzed. It was found that only silver atoms were present and the granular fine particles were silver fine particles.
Next, the collection of silver fine particles formed on the side surface of the sample was peeled off, and the secondary electron beam between 900 and 1000 V of the backscattered electron beam from the side surface of the sample was taken out and image processing was performed. Similar to the side surface of Example 1, a graphene sheet in which the flat surfaces of graphene overlapped with each other could be observed. From this result, it was found that the surface of the graphene sheet was covered with a collection of silver fine particles.
As described above, in Example 1, a graphene sheet in which the flat surfaces of graphene are joined is formed on the bottom surface of the container, and in Example 2, a collection of silver fine particles is deposited on the surface of the graphene sheet, and graphene is formed. The surface of the sheet was covered with silver fine particles. After that, a vibration acceleration of 0.4 G in three directions was applied to the container for a short time, and the sample was taken out from the bottom of the container. At this time, since the silver fine particles were not peeled off from the graphene sheet, it was found that the collection of silver fine particles covered the graphene sheet with a certain strength. Therefore, the graphene sheet can be handled, and when the graphene sheet is placed on the base material or parts and the graphene sheet is compressed, the graphene sheet is crimped to the base material or parts via silver fine particles, and the crimped graphene sheet is , Shows the thermal conductivity of graphene and the conductivity of silver.

Example 3
This example is an example in which the surface of the graphene sheet formed on the bottom surface of the container is covered with a collection of fine particles of _{aluminum oxide Al 2} O _{3 in Example 1.} Aluminum oxide is ^{an insulator having a volume resistivity of 10 14-15} Ω · cm and a dielectric strength of 10-15 kV / mm.
First, 0.1 mol of aluminum benzoate Al (C ₆ H ₅ COO) ₃ (for example, a product of Mitsuwa Chemical Co., Ltd.) was dispersed in 100 cc of methanol to prepare a methanol dispersion. In Example 1, this methanol dispersion was filled in a container in which a graphene sheet was formed on the bottom surface of the container in the shape of the bottom surface.
Next, vibration acceleration in three directions consisting of 0.4 G was repeatedly applied to the container. Further, the container was heated to 310 ° C. in the air atmosphere and left at 310 ° C. for 1 minute. After that, as in Example 1, an aluminum plate was placed on a flat surface above the sample in the container, a weight of 10 kg was further placed, and then the weight and the aluminum plate were taken out. Further, a vibration acceleration of 0.2 G in three directions was applied to the container for a short time, and the sample was taken out from the container. A weight of 5 kg was placed on the sample taken out again, but the fine particles were not peeled off from the surface of the sample.
After that, as in Example 2, observation and analysis of the two planes and sides of the sample were performed with an electron microscope. Granular fine particles having a size of 40-60 nm were evenly stacked and formed on both the flat surface and the side surface, and the granular fine particles were composed of aluminum oxide.
After that, all the aggregates of granular fine particles on the side surface were stripped off, and the side surface was observed again with an electron microscope. As a result, similarly to the side surface of Example 1, a graphene sheet in which the flat surfaces of graphene overlapped with each other could be observed.
From this result, it was found that the surface of the graphene sheet was covered with a collection of fine particles of aluminum oxide. Further, even if the graphene sheet was taken out from the container and a weight of 5 kg was placed on the graphene sheet, the fine particles of aluminum oxide were not dissociated from the graphene sheet. Was joined by frictional heat, and it was found that a collection of fine particles of aluminum oxide covered the surface of the graphene sheet with a certain strength.
From the above results, in Example 1, a graphene sheet in which the flat surfaces of graphene are joined is formed on the bottom surface of the container, and in Example 3, a collection of fine particles of aluminum oxide is deposited on the surface of the graphene sheet, and graphene is formed. The surface of the sheet was covered with a collection of fine particles of aluminum oxide. After that, when compressive stress was evenly applied to the entire flat surface of the graphene sheet, the fine particles of aluminum oxide were joined by frictional heat at the sites where they were in contact with each other. Therefore, the graphene sheet can be handled, and when the graphene sheet is placed on the base material or parts and the graphene sheet is compressed, the graphene sheet is crimped to the base material or parts via fine particles of aluminum oxide and crimped. The graphene sheet has the thermal conductivity of graphene, and the surface exhibits insulating properties.

1 Graphene

Claims (7)

A method for producing a graphene sheet consisting of a group of graphene in which flat surfaces of graphene are overlapped and joined is described.
A collection of scaly graphite particles or a collection of massive graphite particles is flatly packed on the surface of one of the two parallel plate electrodes, and the parallel plate electrode is immersed in methanol filled in a container. Further, the other parallel plate electrode is superposed on the one parallel plate electrode, and the two parallel plate electrodes are separated from each other through a collection of the scaly graphite particles or a collection of the massive graphite particles. , The two separated parallel plate electrodes are immersed in the methanol.
Thereafter, applying a voltage of the DC in a gap between the two parallel plate electrodes, thereby, an electric field corresponding to the magnitude of the potential difference divided by the size of the gap of the two parallel plate electrodes , Which is applied to the aggregate of scaly graphite particles or the aggregate of massive graphite particles, and the application of the electric field is sufficient to break the interlayer bond of the base surface made of graphite crystals for all of the graphite particles. Force is simultaneously applied to all π electrons that are responsible for the interlayer bonding of the basal surface forming the graphite particles, thereby all of the interlayer bonding of the basal surface forming the scaly graphite particles or the massive graphite particles. Is destroyed at the same time, and a collection of graphite corresponding to the basal plane is produced in the gap between the two parallel plate electrodes.
After that, the gap between the two parallel plate electrodes is expanded, the two parallel plate electrodes are tilted in the methanol, and vibration accelerations in three directions of left and right, front and back, and up and down are repeatedly applied to the container. , The aggregate of graphene is moved into the methanol through the gap between the two parallel plate electrodes, and then the two parallel plate electrodes are taken out from the container.
Further, the homogenizer device is operated in the methanol in the container, and the impact is repeatedly applied to the graphene aggregate through the methanol to separate the graphene aggregate into individual graphenes in the methanol. After that, the homogenizer device is taken out from the container.
Further, vibration acceleration in three directions of front-back, left-right, and up-down is repeatedly applied to the container, and a group of graphene in which the flat surfaces of the graphene are overlapped with each other via methanol is formed on the bottom surface of the container as the shape of the bottom surface. do,
After that, the temperature of the container is raised to the boiling point of the methanol to vaporize the methanol, and a collection of graphene in which the flat surfaces of the graphene are overlapped is formed on the bottom surface of the container as the shape of the bottom surface.
Thereafter, the upper plane of the collection of graphene evenly compressed, to generate frictional heat in portions flat surfaces of the graphene are overlapped, flat surfaces of the graphene by the frictional heat is joined, the graphene graphene sheet flat faces are made of a collection of the graphene joined overlap each other, wherein is formed on the bottom of the container as the shape of the bottom surface, consisting of a collection of the graphene bonded overlap flat faces of the graphene graphene how to produce a sheet. Method of covering the surface of the grayed La Fen sheet according to claim 1, silver, copper, gold, or a collection of metal fine particles comprising either metal aluminum,
Silver, copper, gold, or a metal compound or metal aluminum is precipitated by thermal decomposition and dispersed in methanol to create a methanol dispersion, the methanol dispersion, grayed La Fen sheet according to claim 1 Is filled in the container formed on the bottom surface of the container, and further, vibration acceleration in three directions of left and right, front and back, and up and down is repeatedly applied to the container to bring the surface of the graphene sheet into contact with the methanol dispersion.
After that, the temperature of the container is raised to a temperature at which the metal compound is thermally decomposed, whereby the methanol is first vaporized, and a collection of fine crystals of the metal compound is simultaneously deposited on the surface of the graphene sheet. After that, the fine crystals of the metal compound are thermally decomposed, and a collection of granular metal fine particles made of any metal of silver, copper, gold, or aluminum is deposited all at once on the surface of the graphene sheet. The granular metal fine particles are metal-bonded at a site where they come into contact with each other, and the surface of the graphene sheet is covered with a collection of metal fine particles made of the metal-bonded silver, copper, gold, or aluminum. the surface of the grayed La Fen sheet according to claim 1, silver, copper, gold or how to cover a group of metal fine particles comprising any metal aluminum. The method of covering the surface of the graphene sheet according to claim 2 with a collection of metal fine particles made of any of silver, copper, gold, or aluminum.
A metal complex composed of an inorganic metal compound having a metal complex ion in which a ligand composed of an inorganic ion or an inorganic molecule is coordinated to a metal ion composed of a metal of silver, copper, gold, or aluminum. The silver, copper, gold, or aluminum metal according to claim 2 is used as a metal compound that is precipitated by thermal decomposition, and the surface of the graphene sheet is coated with silver, copper, or gold according to the method according to claim 2. , or how to cover a group of metal fine particles comprising any metal aluminum. The method of covering the surface of the graphene sheet according to claim 2 with a collection of metal fine particles made of any of silver, copper, gold, or aluminum.
The first characteristic that the oxygen ion constituting the carboxyl group of the carboxylic acid is covalently bonded to the metal ion made of any metal of silver, copper, gold or aluminum, and the second feature that the carboxylic acid is made of a saturated fatty acid. A metal carboxylate compound having both characteristics is used as a metal compound in which any metal of silver, copper, gold, or aluminum according to claim 2 is precipitated by thermal decomposition, and according to the method according to claim 2. the surface of the graphene sheet, how to cover the silver, copper, gold, or a collection of metal fine particles comprising any metal aluminum. How the surface of the grayed La Fen sheet according to claim 1, covered with a collection of fine particles made of an insulating metal oxide,
A metal compound insulating metal oxide is deposited by pyrolysis and dispersed in methanol to create a methanol dispersion, the methanol dispersion, grayed La Fen sheet according to claim 1 is formed on the bottom surface of the container The container is filled, and further, vibration acceleration in three directions of left and right, front and back, and up and down is repeatedly applied to the container to bring the surface of the graphene sheet into contact with the methanol dispersion.
After that, the temperature of the container is raised to a temperature at which the metal compound is thermally decomposed, whereby the methanol is first vaporized, and a collection of fine crystals of the metal compound is simultaneously deposited on the surface of the graphene sheet. After that, the fine crystals of the metal compound are thermally decomposed, and a collection of the insulating metal oxide fine particles is deposited all at once on the surface of the graphene sheet, and the insulating metal oxide fine particles are deposited. the graphene sheet whose surface is covered with gathered, the is formed on the bottom of the container as the shape of the bottom surface, the surface of the grayed La Fen sheet according to claim 1, the fine particles made of an insulating metal oxide how to cover a collection. The method of covering the surface of the graphene sheet according to claim 5 with a collection of fine particles made of an insulating metal oxide is described.
A metal in which an insulating metal oxide is precipitated by thermal decomposition according to claim 5, wherein an oxygen ion constituting a carboxyl group of the carboxylic acid serves as a ligand to coordinate-bond the carboxylic acid metal compound to the metal ion. used as a compound according to the method described in claim 5, how to cover the surface of the graphene sheets at the collection of fine particles made of an insulating metal oxide. How to retrieve the grayed La Fen sheet according to claim 5 from the container,
According to the method according to claim 5, a graphene sheet whose surface is covered with a collection of fine particles made of an insulating metal oxide is formed on the bottom surface of the container as the shape of the bottom surface, and further, a flat surface above the graphene sheet. Is evenly compressed, whereby frictional heat is generated at a portion where the metal oxide fine particles come into contact with each other in a collection of metal oxide fine particles formed on the surface layers of both planes of the graphene sheet. The frictional heat joins the fine particles of the metal oxide to each other.
Thereafter, the front and rear to the container, left and right, up and down vibration in three directions acceleration added, retrieving the graphene sheet from the container, how removed from container grayed La Fen sheet according to claim 5.