A method for creating a transparent film consisting of a transparent graphene film, in which flattened graphene planes are joined together, bonded to both surfaces of a transparent glass film.

Abstract

A method for creating a transparent film that has superior electrical and thermal conductivity compared to metal, transparency close to that of clear glass, greater impact strength, bending strength, and compressive strength than metal films, heat resistance at the melting point of powdered glass, water repellency and stain resistance of glass films, and a film thickness of 20 μm or less. [Solution] A suspension of powdered glass dispersed in alcohol is filled into a container, and after raising the temperature to a level higher than the softening point of the powdered glass, the surface of the suspension is evenly compressed to create a glass film in which the powdered glass particles are joined at the contact points. Next, a collection of graphene is created from a collection of graphite particles, and a suspension is created in which the flattened surfaces of the graphene particles overlap via alcohol. After this, the suspension is attached to both sides of the glass film, the glass film is sandwiched between two plates, and the surface of the upper plate is evenly compressed to create a transparent film in which transparent graphene films are bonded to both sides of a transparent glass film.

Description

[Technical Field]

[0001] The present invention relates to a method for creating a transparent film with graphene properties by bonding a transparent graphene film, in which flattened graphene planes are joined together, to both surfaces of a transparent glass film. The transparent film of the present invention is created by performing all of the following six steps in succession to create a film in which a transparent graphene film with a thickness of 2 nm or less is bonded to both surfaces of a transparent glass film with a thickness of 20 μm or less. In the first step, a first suspension is prepared by dispersing an aggregate of amorphous glass powder in alcohol with a viscosity of 2-4 mPa·s at 20°C. In the second step, the first suspension is used to create a transparent glass film in which the fluidized amorphous glass powder fills the voids, and the amorphous glass powders are bonded together at the contact points. In the third step, all interlayer bonds at the basal plane forming graphite crystals in the aggregates of flake-like graphite particles or aggregates of massive graphite particles are simultaneously broken while immersed in 1-propanol, creating a second suspension in which the graphene aggregates are dispersed in 1-propanol. In the fourth step, the second suspension is used to create a third suspension in which the flattened surfaces of graphene overlap each other via 1-propanol. In the fifth step, the third suspension is applied to both sides of the transparent glass film. In the sixth step, a transparent glass film to which the third suspension is attached is sandwiched between two plates, 1-propanol is vaporized, and then the entire surface of the upper plate is compressed evenly to create a transparent film in which a transparent graphene film is bonded to both sides of the transparent glass film.

[0002] The present inventor has filed a prior application for a glass film, Japanese Patent Application No. 2023-087211, describing a method for creating a glass film that combines the light-shielding, heat-dissipating, and conductive properties of carbon black with the transparency of amorphous powdered glass. In other words, in the glass film of the prior application, when aggregates of carbon black precipitate on the surface of amorphous powdered glass, they form not the entire surface of the amorphous powdered glass, but more than half of the surface, and also form multiple areas where aggregates are not formed. Therefore, firstly, the aggregates formed on the surface of the amorphous powdered glass provide light shielding and heat dissipation properties; secondly, the transparency of the amorphous powdered glass is exhibited in proportion to the area occupied by the areas where aggregates are not formed on the surface of the amorphous glass; and thirdly, because the aggregates, which are continuously connected aggregates, are formed on the surface of the amorphous powdered glass, they have conductivity corresponding to the conductivity of the aggregates. In contrast, the present invention creates a transparent film consisting of a transparent graphene film, in which flattened graphene planes are joined together, bonded to both surfaces of a transparent glass film. As a result, the transparent film possesses the properties of graphene: electrical conductivity, thermal conductivity, high mechanical strength, and transparency. Therefore, the structure of the transparent film of the present invention differs significantly from the structure of the glass film of the prior application. [Background technology]

[0003] The technology closest to the present invention is conductive glass film. Conductive glass films are used in a wide range of applications, including dye-sensitized solar panels, touch panels, condensation prevention, liquid crystal displays, static electricity removal, dust and debris adhesion prevention, explosion protection, radio wave noise reduction, and sensor electrodes. Therefore, in addition to high conductivity, high thermal conductivity, and high transparency, for outdoor use, high impact strength, bending strength, and compressive strength are all required, as well as high heat resistance. Furthermore, they must not react with acids or alkalis, have excellent water repellency and stain resistance on the surface, and maintain their performance over time. Moreover, the lighter the conductive glass film, the easier it is to assemble it into products for various applications. Therefore, it is necessary to achieve a balance between the thinness of the conductive glass film and its high mechanical strength, which are seemingly contradictory properties.

[0004] The following two patent documents relate to conductive glass films. Patent Document 1 describes a conductive glass film comprising a glass film and a light-transmitting conductive layer laminated on one side of the glass film. The light-transmitting conductive layer has a structure in which a first indium-based conductive oxide layer, a metal layer, and a second indium-based conductive oxide layer are laminated in this order from the glass film side. It is also stated that methods for forming the light-transmitting conductive layer include vacuum deposition, sputtering, and ion plating, and that sputtering methods such as magnetron sputtering are preferably used. Patent Document 2 describes a conductive glass film in which a glass film is laminated with transparent conductive layers formed on both sides of the glass film. It states that the transparent conductive layer is formed on the glass film by ion plating, sputtering, vacuum deposition, etc., using a thin metal film such as gold, silver, or aluminum, or an oxide film such as tin-containing indium oxide (ITO), antimony-containing tin oxide, fluorine-containing tin oxide, or aluminum-containing zinc oxide. Therefore, the conductive glass film in Patent Document 2 is similar in structure to the conductive glass film in Patent Document 1. These two patent documents have the following problems. Firstly, the formation of the light-transmitting conductive layer or transparent conductive layer involves laminating fine particles, resulting in low bonding strength between the light-transmitting conductive layer or transparent conductive layer and the glass film. Secondly, the mechanical strength of the conductive glass film depends on its thickness; therefore, the thinner the glass film, the weaker it is against impact and bending. On the other hand, the thicker the glass film, the more difficult it becomes to handle. Thirdly, because metal oxide or metal fine particles are laminated on the surface of the conductive glass film, the surface of the conductive glass film is prone to soiling, and the properties of the glass film change over time. Fourthly, the formation of the light-transmitting conductive layer or transparent conductive layer is a thin film formation by a so-called dry method, which results in high costs for thin film formation. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-176332 [Patent Document 2] Japanese Patent Publication No. 2014-075061 [Non-patent literature]

[0006] [Non-Patent Document 1] Takaiti Takemasa, “Performance and Way to use of Electric Brush(in Japanese)”, P113-119, Tokyo Denki University 1958 [Non-Patent Document 2] Matsukawa: Carbon in Japanese, No. 17, 11 (1955) [Non-Patent Document 3] JDBernal:Proc. Roy. Soc.A106, P749-773, 1924 [Non-Patent Document 4] P. Debye, P. Scherrer: Phys z., 18, P291, 1917 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0007] As described in paragraph 3, conductive glass films are used in a variety of applications, and therefore require various performance characteristics depending on the application. However, to date, no conductive glass film exists that possesses all of the performance characteristics described in paragraph 3. Therefore, the problem that this invention aims to solve is to find a method for creating a transparent film that possesses all of the performance characteristics described in paragraph 3. That is, the transparent film of the present invention has the following seven properties in combination. First, it has electrical conductivity superior to that of metals. Second, it has thermal conductivity superior to that of metals. Third, it has transparency close to that of transparent plate glass. Fourth, it combines greater impact strength, flexural strength and compressive strength than metal films of the same thickness. Fifth, its heat resistance is close to the melting point of amorphous powdered glass. Sixth, it has excellent surface flatness, and has water repellency and stain resistance close to those of glass films. Seventh, the thickness of the transparent film is 20 μm or less. The problem to be solved by the present invention is to find a method for producing a transparent film having all these seven properties. Note that granular glass is called by various names such as glass frit, glass particles, and glass powder, and is described as powdered glass in the present invention. In addition, according to JIS packaging terminology standards, a plastic film with a thickness of less than 0.25 mm is referred to as a plastic film. Since the thickness of the film of the present invention is 20 μm or less, it is described as a film herein.

[0008] Powdered glass is produced by mixing multiple types of raw material metal oxides in a formulated proportion, heating and melting the mixture to vitrify it, and then pulverizing it into fine powder by water quenching or roll quenching. For this reason, powdered glass can have various compositions and compositional ratios. Powdered glass is also divided into two categories: crystalline and amorphous (also referred to as non-crystalline). In crystalline powdered glass, the constituent molecular structures are arranged three-dimensionally in a regular array, so light is reflected at the crystal interfaces, resulting in loss of transparency. On the other hand, because the molecular structures are arranged three-dimensionally in a regular array, crystalline powdered glass is superior to amorphous powdered glass in thermal shock resistance and mechanical strength. In contrast, amorphous glass powder has transparency. That is, amorphous glass powder has a non-crystalline structure that does not three-dimensionally form a crystal lattice, and thus has light-transmitting permeability. However, due to its non-crystalline structure, it is inferior to crystalline powdered glass in thermal shock resistance and mechanical strength. In addition, powdered glass is used in three applications: binders, sealing, and heat resistance. The particle size of powdered glass for binders is small, and the median particle diameter of well over 90% of such powdered glass is smaller than 10 μm. On the other hand, from the perspective of the RoHS Directive, it is desirable to use lead-free glass powder glass. Lead-free glasses include phosphate-based glasses containing P2O5 as a main component, bismuth-based glasses containing Bi2O3 as a main component, vanadate-based glasses composed of V2O5, alkali metal oxides, alkaline earth metal oxides, zinc oxide, boron oxide, phosphorus pentoxide, tellurium oxide and the like, borosilicate-based glasses composed of SiO2, B2O3 and alkali metal oxides or alkaline earth metal oxides, and fluoride-based glasses containing BeF2 as a main component. Furthermore, since each of the following metal oxides, which are main raw materials for glass, has unique functions, the softening point and coefficient of linear expansion of the powdered glass can be freely changed depending on the ratio of the metal oxides. Silicon oxide (SiO2) forms the network structure of glass, and functions to increase the softening point and reduce thermal expansion. In contrast, boron oxide (B2O3) forms the network structure of glass and functions to lower the softening point. Titanium oxide (TiO2) functions to promote crystallization and increase the softening point. Alumina (Al2O3) suppresses crystallization and functions to increase the softening point. In contrast, sodium oxide (Na2O) functions to lower the softening temperature and increase thermal expansion, but is inferior in hot water resistance. On the other hand, potassium oxide (K2O) has properties similar to Na2O, but K + is larger than Na + by 1.4 times, so it is difficult to move and provides hot water resistance. Furthermore, calcium oxide (CaO) has properties similar to Na2O, but improves the chemical durability of alkali glass. [Means for Solving the Problem]

[0009] The method for producing a transparent film according to the present invention, which has a configuration in which a transparent graphene film in which flat surfaces of graphenes are bonded to each other is bonded to both surfaces of a transparent glass film, comprises: The first step involves weighing amorphous glass powder in a weight corresponding to the thickness and size of the transparent glass film to be created, and placing the amorphous glass powder into a first container; further, adding alcohol having a viscosity of 2-4 mPa·s at 20°C, with a viscosity corresponding to the size of the amorphous glass powder and a weight of at least 10 times the weight of the amorphous glass powder placed in the first container, and stirring the alcohol to create a first suspension in which the aggregate of amorphous glass powder is dispersed in the alcohol; A second container is prepared, the size of which matches the size of the transparent glass film to be created, and the depth of the container is 1 cm or less. A first plate material is prepared, the size of which matches the size of the transparent glass film to be created. The first suspension is filled into the second container. After this, the second container is heated to a temperature higher than the softening point of the amorphous powdered glass, and the first suspension filled in the second container is transformed into an aggregate of fluidized amorphous powdered glass. Furthermore, the first plate material is placed over the surface of the aggregate of fluidized amorphous powdered glass, and a compressive load is applied evenly to the entire surface of the first plate material. As a result, the fluidized amorphous powdered glass moves and fills all the voids, and furthermore, the fluidized amorphous powdered glass comes into contact with each other. A second step in creating a transparent glass film is performed, comprising the following steps: 1. A planar, transparent glass film is formed on the bottom surface of the second container by friction welding, and 2. An impact acceleration of the same magnitude is repeatedly applied simultaneously to multiple locations on the bottom surface of the second container to peel the transparent glass film away from the bottom surface of the second container. 3. The first plate material to which the transparent glass film is joined is positioned so that the transparent glass film faces upward, and an impact acceleration of the same magnitude applied to the second container is repeatedly applied simultaneously to multiple locations on the bottom surface of the first plate material to peel the transparent glass film away from the first plate material. On the surface of one of two parallel plate electrode plates of the same size, an aggregate of flake-shaped graphite particles or an aggregate of lumpy graphite particles is spread evenly, and the one parallel plate electrode plate on which the aggregate of flake-shaped graphite particles or the aggregate of lumpy graphite particles is spread is immersed in 1-propanol filled in a third container, and the other parallel plate electrode plate is then placed on top of the one parallel plate electrode plate, and the aggregate of flake-shaped graphite particles or the The two parallel plate electrodes are separated into a predetermined gap via an aggregate of lumpy graphite particles, and the two parallel plate electrodes separated into the predetermined gap are immersed in 1-propanol. After this, a DC potential difference of a predetermined size is applied to the gap between the two parallel plate electrodes, thereby generating an electric field equivalent to the value obtained by dividing the magnitude of the potential difference by the size of the gap between the two parallel plate electrodes, which is then applied to the scales laid in the gap between the two parallel plate electrodes. A mixture of flaky graphite particles or a mixture of lumpy graphite particles is subjected to a process that simultaneously breaks all interlayer bonds of the basal surface forming the flaky or lumpy graphite particles, causing a mass of graphene corresponding to the basal surface to precipitate simultaneously in the gap between the two parallel plate electrodes. After this, the gap between the two parallel plate electrodes is widened, the two parallel plate electrodes are tilted in the 1-propanol, and the third container is subjected to vibration in three directions: front-to-back, left-to-right, and up-and-down. A third step to create a graphene aggregate from a graphite particle aggregate and a second suspension in which the graphene aggregate is dispersed in 1-propanol, comprising repeatedly applying velocity to move the graphene aggregate from the gap between the two parallel plate electrode plates into the 1-propanol, and creating a second suspension in which the graphene aggregate is dispersed in the 1-propanol, and further removing the two parallel plate electrode plates from the third container, A fourth step is to create a third suspension in which the flattened surfaces of graphene overlap via 1-propanol, and this suspension is created by filling the second container used in the second step with the second suspension in an amount corresponding to the size and thickness of the transparent graphene film to be bonded to both sides of the transparent glass film created in the second step, then placing the second container on the vibration platform of a vibration machine, operating the vibration machine, and repeatedly applying vibration acceleration in three directions (front-back, left-right, up-down) to the second container, thereby creating a third suspension in which the flattened surfaces of graphene overlap via 1-propanol. A fifth step involves immersing the transparent glass film prepared in the second step in the third suspension in the second container, thereby adhering the third suspension to both sides of the transparent glass film. A second plate material is prepared, the size of the transparent glass film created in the second step. The transparent glass film, with the third suspension attached to both sides, created in the fifth step, is placed on top of the second plate material. Furthermore, a third plate material, the size of the transparent glass film created in the second step, is placed on top of the transparent glass film with the third suspension attached to both sides. After this, the transparent glass film, with the third suspension attached to both sides, sandwiched between the second and third plates, is heated to a temperature above the boiling point of 1-propanol. This vaporizes the 1-propanol from the third suspension attached to both sides of the transparent glass film, transforming the third suspension attached to both sides of the transparent glass film into an aggregate of graphene with flattened planes overlapping. Furthermore, the entire surface of the third plate material is compressed uniformly. This compresses the aggregate of graphene with flattened planes overlapping, and A transparent graphene film having a thickness of 2 nm or less is formed by friction welding two flat surfaces together, and then the transparent graphene film is bonded to both surfaces of the transparent glass film by friction welding, thereby creating a transparent film having a configuration in which the transparent graphene film is bonded to both surfaces of the transparent glass film. Subsequently, an impact acceleration of the same magnitude is repeatedly and simultaneously applied to multiple locations on the bottom surface of the second plate material to peel the transparent film from the bottom surface of the second plate material. Furthermore, the third plate material to which the transparent film is bonded is positioned so that the transparent film is facing upward, and an impact acceleration of the same magnitude as applied to the second plate material is repeatedly and simultaneously applied to multiple locations on the bottom surface of the third plate material to peel the transparent film from the third plate material. This process constitutes a sixth step in creating a transparent film having a configuration in which the transparent graphene film is bonded to both surfaces of the transparent glass film. A method for creating a transparent film in which a transparent graphene film, in which flattened graphene sheets are bonded together, is bonded to both surfaces of a transparent glass film, by performing all of these six processes in sequence.

[0010] The following six steps are performed sequentially to create a transparent film consisting of a transparent graphene film, where flattened graphene sheets are bonded together, bonded to both sides of a transparent glass film. The six steps and their effects are explained below. In the first step, an aggregate of amorphous powdered glass is dispersed in alcohol with a viscosity of 2-4 mPa·s at 20°C to create a first suspension. For this purpose, amorphous powdered glass is weighed according to the thickness and size of the transparent glass film to be created and placed in the first container. Furthermore, alcohol with a viscosity of 2-4 mPa·s at 20°C is added to the first container, with a viscosity corresponding to the size of the powdered glass and a weight of at least 10 times the weight of the amorphous powdered glass placed in the first container. The alcohol is then stirred to create the first suspension. In other words, one of the objectives of the present invention is to realize a transparent film that possesses seemingly contradictory properties: a thickness of 20 μm or less, significantly thinner than conventional transparent films, significantly lighter than conventional transparent films, and yet significantly higher mechanical strength than conventional transparent films. To this end, amorphous powdered glass consisting of micron-sized particles, which are relatively small, is used. On the other hand, amorphous powdered glass has a particle size variation of an order of magnitude. Therefore, when using amorphous powdered glass with relatively large particles, an alcohol with relatively high viscosity is used, and the alcohol is adsorbed onto the fine amorphous powdered glass according to the viscosity of the alcohol, thereby stably dispersing the amorphous powdered glass in the alcohol.

[0011] In the second step, a transparent glass film is created using the first suspension. To this end, a second container is prepared, the size of which matches the size of the transparent glass film to be created, and the depth of the container is 1 cm or less. A first plate material is also prepared to cover the entire surface of the aggregate of fluidized amorphous powdered glass. Specifically, the first suspension is filled into the second container, the second container is heated to a temperature higher than the softening point of the amorphous powdered glass, the alcohol is vaporized from the first suspension, the amorphous powdered glass is softened, and then fluidized. At this time, aggregates of amorphous powdered glass of micron size precipitate in layers with high density, and then the amorphous powdered glass softens and becomes fluidized. Furthermore, the first plate material is placed over the surface of the aggregate of fluidized amorphous powdered glass, and the entire surface of the first plate material is compressed evenly. As a result, the fluidized amorphous glass powder moves and fills all the voids. Furthermore, the overlapping fluidized amorphous glass powders are joined together by frictional pressure at the contact points, creating a planar, transparent glass film composed of these joined fluidized amorphous glass powders. Because the amorphous glass powders are small, on a micron scale, a vast number of fluidized amorphous glass powders overlap at a high density and join at the contact points, resulting in a strong bonding force between the amorphous glass powders. Consequently, a planar, transparent glass film composed of these joined fluidized amorphous glass powders is formed on the bottom surface of the second container. The transparent glass film is bonded to the bottom surface of the second container and the compression surface of the first plate material by friction welding. To achieve this, impact accelerations of the same magnitude are repeatedly applied simultaneously to multiple points on the bottom surface of the second container, peeling the transparent glass film away from the bottom surface of the second container. Furthermore, the first plate material to which the transparent glass film is bonded is positioned so that the transparent glass film faces upward, and impact accelerations of the same magnitude applied to the second container are repeatedly applied simultaneously to multiple points on the bottom surface of the first plate material, peeling the transparent glass film away from the first plate material. As a result, a transparent glass film with the shape of the bottom surface of the second container is created. In other words, the weight of the transparent glass film is significantly less than the weight of the second container. Furthermore, when impact acceleration is applied simultaneously to multiple points on the bottom surface of the second container, the impact force is directly transmitted to the fluidized amorphous powdered glass in contact with the protrusions on the bottom surface of the second container. Therefore, the impact force received by the fluidized amorphous powdered glass bonded to the bottom surface of the second container from the second container is greater than the impact force received by the transparent glass film from the second container. Also, the amount of fluidized amorphous powdered glass in contact with the protrusions on the bottom surface of the second container is significantly less than the amount of amorphous powdered glass bonded to other fluidized amorphous powdered glass. For this reason, when impact acceleration is repeatedly applied simultaneously to multiple points on the bottom surface of the second container, the greatest impact force is applied to all of the fluidized amorphous powdered glass bonded to the bottom surface of the second container, and all of the fluidized amorphous powdered glass bonded to the bottom surface of the second container preferentially peels off from the bottom surface of the second container. Similarly, when impact acceleration is repeatedly applied simultaneously to multiple points on the bottom surface of the first plate, the greatest impact force is applied to the fluidized amorphous powdered glass bonded to the compression surface of the first plate. Furthermore, the amount of fluidized amorphous powdered glass in contact with the convex portion of the bottom surface of the first plate is significantly less than the amount of amorphous powdered glass bonded to other fluidized amorphous powdered glass. Therefore, when impact acceleration is repeatedly applied simultaneously to multiple points on the bottom surface of the first plate, the greatest impact force is applied to the fluidized amorphous powdered glass bonded to the bottom surface of the first plate, and all of the fluidized amorphous powdered glass bonded to the compression surface of the first plate preferentially peels off from the compression surface of the first plate.

[0012] In the third step, a collection of graphene is created from the collection of graphite particles, and a second suspension is created in which the graphene collection is dispersed in 1-propanol. Specifically, a collection of graphite particles, which is packed into a predetermined gap between two parallel plate electrodes, is immersed in 1-propanol, and a predetermined DC potential difference is applied to the gap between the two parallel plate electrodes. This applies an electric field to the collection of graphite particles that is equivalent to the value obtained by dividing the magnitude of the potential difference by the size of the gap between the two parallel plate electrodes. This application of an electric field simultaneously applies a Coulomb force to all π electrons, which are carriers of the interlayer bonds between the basal planes of the graphite crystals, that is sufficient to break the interlayer bonds between the basal planes of all the graphite particles. As a result, all the interlayer bonds between the basal planes forming the graphite particles are simultaneously broken, and a collection of graphene corresponding to the basal plane is deposited in the gap between the two parallel plate electrodes. The precipitated graphene is an intrinsic substance consisting only of graphite crystals and free of impurities. Furthermore, because the aggregate of graphene precipitates in 1-propanol, the precipitated graphene maintains an intrinsic state completely free of foreign matter within the 1-propanol. In addition, since the two parallel plate electrodes are immersed in 1-propanol, the aggregate of graphene precipitated in the gap between the two parallel plate electrodes does not scatter. Moreover, since 1-propanol is an insulator with a dielectric constant of 20.8, when a potential difference is applied to the gap between the two parallel plate electrodes immersed in 1-propanol, an electric field is generated in the gap between the two parallel plate electrodes. Here, we explain the phenomenon in which the interlayer bonds of the basal plane, which consists of graphite crystals forming graphite particles packed in the gap between two parallel plate electrodes, are simultaneously broken by an electric field applied to the gap between the two parallel plate electrodes. The carbon atoms that form the graphite crystal in graphite particles have four valence electrons. Three of these valence electrons are σ electrons that form the basal plane, i.e., graphene. These σ electrons covalently bond with the σ electrons of three adjacent carbon atoms on the basal plane at a 120-degree angle to each other, forming a strong hexagonal network structure in two dimensions. The remaining valence electron is a π electron, which lies on a π orbital extending perpendicular to the basal plane. This π electron bonds with the π electrons of adjacent carbon atoms in the vertical direction perpendicular to the basal plane through a weak bond called van der Waals interaction, and the basal plane is stacked in layers based on this van der Waals interaction. In other words, the basal plane, i.e., graphene, is bonded to each other in layers by the interaction of π orbitals, which is a weak bond. For this reason, graphite particles have a property of being easily peeled off at the basal plane, which is made up of graphite crystals, i.e., mechanical anisotropy. This mechanical anisotropy is well known as the lubricity of graphite particles. In other words, mechanical anisotropy is based on the anisotropy of the electronic structure between σ electron bonds and π electron bonds. Furthermore, it has been reported that the magnitude of the van der Waals interaction calculated is 20-26 meV / atom (Non-Patent Documents 1-3), while the magnitude obtained experimentally is 35 meV / atom (Non-Patent Document 4). When an electric field is applied to these graphite particles, a Coulomb force acts on all the π electrons due to the electric field. If the Coulomb force acting on the π electrons is greater than the van der Waals interaction of the π orbitals acting on the π electrons, the π electrons are released from their constraints on the π orbitals. As a result, all the π electrons leave the π orbitals and become free electrons. This causes all the interlayer bonds at the base plane to be destroyed simultaneously, as all the π electrons that carry the interlayer bonds at the base plane are no longer in the π orbitals. In other words, when a π electron moves a distance b between the layers at the base plane due to the Coulomb force F, the π electron performs work W (W = b·F). This work W is equal to 35 meV (electron volts is a unit representing the energy of an electron, and 1 electron volt is 1.62 × 10¹⁶) which is the magnitude of the interaction of the π orbitals per atom acting on the π electrons. -19When the electric field exceeds a certain value (equivalent to a joule), the π electrons are released from the constraints of the π orbital interaction and become free electrons. For example, if two parallel plate electrodes are spaced 100 μm apart and a DC potential difference of 10.6 kilovolts or more is applied to this gap, the interlayer bonds of the basal plane are instantly destroyed. In this way, a large amount of graphene can be manufactured cheaply by the extremely simple method of applying an electric field to an assembly of inexpensive graphite particles. Furthermore, since all the interlayer bonds of the basal plane of the graphite crystal are destroyed simultaneously, the resulting fine material is reliably graphene, which corresponds to the basal plane made of graphite crystals. The term "aggregate of graphite particles" here refers to a relatively small amount of graphite particles, ranging from about 1g to 10g. In other words, flaky or lumpy graphite particles have a bulk density of 0.2-0.5g / cm³. 3 The particles are very fine, with a particle size distribution ranging from 1 to 300 microns. Therefore, it is easy to lay a collection of graphite particles flatly in the gap between two parallel plate electrodes, and it is also easy to apply a potential difference between 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 areas where the graphite particles are laid flat. The electric field acts on the π electrons as a Coulomb force, which is stronger than the van der Waals interaction of the π orbitals, and the π electrons are released from their constraints on the π orbitals and become free electrons. As a result, all the interlayer bonds at the base plane of the graphite crystal in the graphite particles are simultaneously destroyed, and a collection of graphene is deposited in the gap between the two parallel plate electrodes. Here, we arithmetically determine the number of graphene particles that precipitate in 1-propanol. Here, we assume that all graphite particles consist of spheres with a diameter of 25 microns, and that the true density of graphite is 2.25 × 10⁻⁶. 3 kg / m 3 Therefore, the weight of a single graphite particle is only 1.84 × 10⁻⁶ -8g. Further, assuming that the average value of the thickness of the graphite particles is 10 microns, 297,265 graphene sheets are stacked in the flaky graphite particles having an interlayer distance of 3.354 Å and a thickness of 10 microns. Therefore, when all interlayer bonds of the basal planes are broken, a collection of 297,265 graphene sheets can be obtained from only one spherical graphite particle. Accordingly, when all interlayer bonds of the basal planes are broken for a collection of only 1 g of spherical graphite particles, 1.62×10 13 graphene sheets can be obtained. As described above, according to the present production method, an enormous number of graphene sheets can be obtained from a small amount of collected graphite particles.

[0013] In the fourth step, the second suspension is used to prepare a third suspension in which flat surfaces of graphene overlap each other via 1-propanol. For this purpose, the second container used in the second step is filled with the second suspension in an amount corresponding to the size and the thickness of 2 nm or less of the transparent graphene film to be bonded to both surfaces of the transparent glass film prepared in the second step. Thereafter, the second container is placed on a vibration table of a vibrator, the vibrator is operated, and vibration accelerations of 0.3 to 0.5 G in three directions of front-back, left-right, and up-down are repeatedly applied to the second container according to the amount of the second suspension, thereby preparing the third suspension in which the flat surfaces of graphene overlap each other via 1-propanol. That is, since graphene has an extremely small thickness of 0.332 nm, it has an extremely large aspect ratio, which is the ratio of the size of the flat surface to the thickness. Further, graphene has almost no mass. Furthermore, the flat surfaces of graphene separated into individual sheets are in contact with 1-propanol. On the other hand, 1-propanol has a density of 0.804 g / cm 3Because it is small and has a low viscosity of 1.9 mPa·s at 20°C, when vibrational acceleration is applied to the container, 1-propanol easily moves in the direction of the vibrational acceleration. Along with this movement of 1-propanol, graphene also moves. On the other hand, graphene with an extremely large aspect ratio moves through 1-propanol with its flattened surface facing upwards, which places the least load on the graphene, so the graphene moves through 1-propanol in the direction of vibration with its flattened surface facing upwards. Consequently, when vibrational acceleration in three directions is repeatedly applied to a collection of graphene, the collection of graphene becomes one in which the flattened surfaces of the graphene overlap through 1-propanol. Furthermore, because graphene is extremely thin, it has extremely high transparency with a total light transmittance of 97.7%. Therefore, a graphene film made by joining five flattened graphene sheets has a thickness of 1.7 nm and a total light transmittance of 89%, a graphene film made by joining six flattened graphene sheets has a thickness of 2.0 nm and a total light transmittance of 87%, and a graphene film made by joining seven flattened graphene sheets has a thickness of 2.3 nm and a total light transmittance of 85%. Thus, graphene films with a thickness of 2 nm or less have excellent transparency with a total light transmittance of 85% or more. For this reason, in order to make a graphene film transparent, the thickness of the graphene film needs to be 2 nm or less. For comparison, the total light transmittance of transparent plate glass is 85-90%.

[0014] In the fifth step, the transparent glass film prepared in the second step is immersed in the third suspension in the second container, so that the third suspension adheres to both sides of the transparent glass film. When the transparent glass film is immersed in the third suspension, a load is applied to the cluster of graphene particles, where the flattened surfaces of the graphene particles overlap, via 1-propanol. However, because the aspect ratio of graphene is extremely large and graphene has almost no mass, the graphene is adsorbed onto the 1-propanol, and the cluster of graphene particles maintains its state of overlapping flattened surfaces.

[0015] In the sixth step, a transparent film is created in which a transparent graphene film is bonded to both sides of a transparent glass film. First, a second plate material is prepared that is the same size as the transparent glass film created in the second step, and the transparent glass film with the third suspension attached to both sides, created in the fifth step, is placed on top of the second plate material. Furthermore, a third plate material, the same size as the transparent glass film created in the second step, is placed on top of the transparent glass film with the third suspension attached to both sides. After this, the glass film sandwiched between the second and third plates is heated to a temperature above the boiling point of 1-propanol, vaporizing the 1-propanol from the third suspension attached to both sides of the transparent glass film, and transforming the third suspension attached to both sides of the transparent glass film into an aggregate of graphene with flattened surfaces overlapping each other. Furthermore, in the third suspension, the aggregate of graphene dispersed in 1-propanol maintained an intrinsic state free of foreign matter due to the presence of 1-propanol. Therefore, the aggregate of graphene with overlapping flattened surfaces that appeared after the vaporization of 1-propanol was also intrinsic state free of foreign matter. Next, the entire surface of the third plate material is uniformly compressed. This compresses the aggregate of overlapping flattened surfaces of graphene, forming a graphene film with a thickness of 2 nm or less, where the flattened surfaces are joined by friction welding. This graphene film is transparent. This transparent graphene film is then joined to both sides of a transparent glass film by friction welding, creating a transparent film consisting of transparent graphene film joined to both sides of a transparent glass film. Meanwhile, because the flattened surfaces of graphene, which are perfect planes in an intrinsic state free of foreign matter, are joined by friction welding, the graphene particles, which have almost no mass, are strongly bonded together. Furthermore, graphene has a tensile strength of 42 N / m, which is more than 100 times stronger than steel, and is an extremely tough material with a Young's modulus of 1020 GPa. Therefore, even if excessive compressive stress is applied to graphene, which is extremely thin at 0.332 nm, the graphene will not break.Therefore, when excessive compressive stress is applied to a collection of graphene where flattened surfaces overlap, excessive frictional heat is generated in the overlapping flattened surfaces, causing the flattened surfaces to join together through frictional pressure welding. Next, impact accelerations of the same magnitude, ranging from 0.2 to 0.3 G, corresponding to the size of the transparent film, are repeatedly and simultaneously applied to multiple points on the bottom surface of the second plate material, peeling the transparent film away from the bottom surface of the second plate material. Furthermore, the third plate material to which the transparent film is bonded is positioned so that the transparent film faces upward, and impact accelerations of 0.2 to 0.3 G are repeatedly and simultaneously applied to multiple points on the bottom surface of the third plate material, peeling the transparent film away from the third plate material. As a result, a transparent film is created in which a transparent graphene film is bonded to both sides of a transparent glass film. In other words, the flattened surfaces of graphene are perfectly flat. Furthermore, graphene has almost no mass. For this reason, the flattened surfaces of graphene are strongly joined together by frictional pressure. In contrast, the surface of the second plate material that contacts the graphene has numerous irregularities, and the protrusions of these irregularities join with the graphene that contacts them. On the other hand, the flattened surfaces of graphene are joined together as perfectly flat surfaces. Therefore, the bonding force between the surface of the second plate material and the flattened surfaces of graphene is significantly smaller than the bonding force between the flattened surfaces of graphene. Also, the weight of the graphene film is significantly smaller than the weight of the second plate material. Furthermore, if impact acceleration is applied simultaneously to multiple points on the bottom surface of the second plate material, the impact force is directly transmitted to the flattened surfaces of graphene that are in contact with the protrusions on the bottom surface of the second plate material. Therefore, the impact force that the graphene joined to the bottom surface of the second plate material receives from the second plate material is greater than the impact force that the transparent graphene film receives from the second plate material. Therefore, when impact acceleration is repeatedly applied simultaneously to multiple points on the bottom surface of the second plate, the greatest impact force is applied to all the graphene bonded to the bottom surface of the second plate, and all the graphene bonded to the bottom surface of the second plate preferentially peels off from the bottom surface of the second plate. Similarly, when impact acceleration is repeatedly applied simultaneously to multiple points on the bottom surface of the third plate, the greatest impact force is applied to all the graphene bonded to the compression surface of the third plate, and all the graphene bonded to the compression surface of the third plate preferentially peels off from the compression surface of the third plate. As a result, the transparent film, in which the transparent graphene film is bonded to both sides of the transparent glass film, is peeled off from both the second and third plate molds. Furthermore, on the surface of the transparent glass film created in the second step, the bonded amorphous glass powder, which is micron-sized, is exposed. As a result, a vast number of amorphous glass powders form the surface of the transparent glass film. Therefore, the vast number of flattened graphene particles that make up the transparent graphene film are bonded to the vast number of micron-sized amorphous glass powders by friction pressure. Consequently, the transparent graphene film is bonded to the transparent glass film with great bonding force. Therefore, the transparent graphene film cannot be peeled off the surface of the flat transparent glass film. Thus, the transparent film, in which the transparent graphene film is friction-bonded to both sides of the transparent glass film, possesses the properties of a graphene film. When all six steps described above are carried out sequentially, a transparent film is created in which a transparent graphene film is bonded to both sides of a transparent glass film. This film exhibits the following effects and possesses the seven properties described in paragraph 7. This solves the problem to be solved in the present invention.

[0016] The transparent film possesses the properties of graphene because a transparent graphene film is bonded to both sides of a transparent glass film. Here, we will explain the properties of graphene. Graphene has a thickness of 0.332 nm, making it the thinnest of all materials, and its mass is 0.77 mg / m². 2 It is the lightest of all substances, with a surface area of ​​3000 m² per unit mass. 2Graphene has a density of 1 / g, giving it the largest surface area of ​​all materials. Furthermore, because graphene is extremely thin, its aspect ratio, which is the ratio of the area of ​​the flattened plane to the thickness, is extremely large. As a result, the properties of the flattened plane of graphene exhibit significantly greater anisotropy than the properties of its thickness. On the other hand, the aspect ratio of a graphene film, formed by joining flattened graphene particles, is even larger than that of graphene. Since the properties of the flattened plane are dominant in graphene, a graphene film formed by joining flattened graphene particles has properties similar to those of the flattened plane of graphene. For example, the thermal conductivity of graphene in the thickness direction is small, and heat is preferentially transferred in the direction of the flattened plane. Also, the electrical conductivity of graphene in the thickness direction is small, and electrons are preferentially transferred in the direction of the flattened plane. Thus, the properties of graphene exhibit anisotropy, where the properties differ greatly between the thickness direction and the direction of the flattened plane. Therefore, in a graphene film, since all the graphene particles are joined together as flattened planes, the properties of the flattened plane of graphene become dominant, and the film has properties similar to those of graphene. Furthermore, flattened graphene particles, which are perfectly flat and have almost no mass, are joined together by frictional pressure to form a graphene film. As a result, the bonding force between graphene particles in the graphene film is extremely strong, and because the thickness of the graphene is extremely thin at 0.332 nm, it is difficult to break the bonds between the graphene particles. Here, we will explain the various excellent properties of graphene based on its anisotropy. For example, the thermal conductivity of the flattened plane is 1880 W / mK, which is 4.5 times that of silver, the metal with the highest thermal conductivity. The volume resistivity of the flattened plane is 1.3 μΩcm, which is even lower than the volume resistivity of silver, the metal with the lowest volume resistivity, which is 1.6 μΩcm. The conductivity of the flattened plane is 7.5 × 10⁻⁶. 7 Silver has a conductivity of 6.1 × 10⁻¹⁰ S / m, making it the most electrically conductive metal. 7 It is even higher than S / m. The electron mobility of the flattened plane is 200,000 cm². 2 The electron mobility is 77,000 cm² / volt-second, and indium antimony (InSb), which has the highest electron mobility among semiconductors, has an electron mobility of 77,000 cm². 2It is nearly three times faster than a volt-second. Furthermore, the flattened plane is composed of single crystals with a melting point exceeding 3000°C and a heat resistance temperature exceeding 3000°C. In addition, it has chemical stability and does not react with any acids or alkalis. The flattened plane has a breaking strength of 42 N / m, which is more than 100 times stronger than steel, and is an extremely tough material with a Young's modulus of 1020 GPa. Therefore, even if excessive compressive stress is applied to a graphene film in which flattened planes are joined together, the graphene will not break. Furthermore, because graphene is extremely thin, it has extremely high transparency with a total light transmittance of 97.7%. Therefore, a graphene film made by joining five flattened graphene sheets has a thickness of 1.7 nm and a total light transmittance of 89%, a graphene film made by joining six flattened graphene sheets has a thickness of 2.0 nm and a total light transmittance of 87%, and a graphene film made by joining seven flattened graphene sheets has a thickness of 2.3 nm and a total light transmittance of 85%. Thus, graphene films with a thickness of 2.3 nm or less have excellent transparency with a total light transmittance of 85% or more. For this reason, in order to give graphene film transparency, the thickness of the graphene film needs to be 2 nm or less. For comparison, the total light transmittance of transparent plate glass is 85-90%. Furthermore, transparent graphene film is formed by directly joining flattened planes, which are extremely lightweight and have an extremely large aspect ratio, to graphene, an intrinsic substance consisting only of the basal plane of graphite crystals, using friction welding. As a result, the flattened planes are strongly bonded together. In addition, the surface of the transparent graphene film has a step of only 0.332 nm, which corresponds to the thickness of the graphene, giving the surface of the transparent graphene film a lubricating effect. Moreover, the surface of the transparent graphene film is water-repellent and stain-resistant. Therefore, a film consisting of a transparent glass film with a graphene film thickness of 2 nm or less covering the entire surface is formed as an extremely lightweight transparent film with the properties of graphene film.

[0017] Here, we will explain the properties of the transparent film we created. Firstly, the transparent film created has a volume resistivity close to that of graphene, which is 1.3 μΩcm, and also has an conductivity of 7.5 × 10⁻⁶, which is that of graphene. 7 Because it has a conductivity close to S / m, it has superior conductivity to that of metals. Secondly, the transparent film created has a thermal conductivity close to that of graphene, which is 1880 W / mK, meaning the film has superior thermal conductivity compared to metals. Thirdly, a graphene film made by bonding together seven or fewer sheets of graphene has a total light transmittance of 85% or more, so the resulting transparent film has a transparency close to that of clear glass. Fourthly, because the transparent graphene film has a breaking strength close to that of graphene, which is 42 N / m, the resulting transparent film possesses higher impact strength, bending strength, and compressive strength than a metal film of the same thickness. Fifth, while the transparent graphene film has heat resistance close to that of graphene (3000°C), the transparent film created has heat resistance equal to the melting point of the glass powder that makes up the glass film. Sixth, because the surface of the transparent graphene film has a step of only 0.332 nm, it is nearly perfectly flat, and the resulting transparent film has superior water repellency and stain resistance compared to glass film. Seventh, a transparent glass film with a thickness of 20 μm or less can be created, and a transparent graphene film with a thickness of 2 nm or less can be bonded to the surface of the transparent glass film to produce a transparent film with a thickness of 20 μm or less. Therefore, the six-step method for creating a transparent film according to the present invention is a method for creating a transparent film that can form a film possessing the seven properties described in paragraph 7.

[0018] The method for creating a transparent film, which consists of a transparent graphene film in which flattened graphene surfaces are joined together as described in paragraph 9, being bonded to both surfaces of a transparent glass film, is as follows: The amorphous powdered glass described in paragraph 9 is amorphous powdered glass having a central particle size of 5 μm or less and a softening point lower than 500°C, and the amorphous powdered glass is used as the amorphous powdered glass described in paragraph 9, and the processing in the first step, the second step, the fifth step, and the sixth step described in paragraph 9 are carried out. A method for creating a transparent film, comprising a transparent graphene film in which flattened graphene surfaces, as described in paragraph 9, are joined together, and then joined to both surfaces of a transparent glass film.

[0019] In short, powdered glass is divided into two types: crystalline and amorphous (also called non-crystalline). Crystalline powdered glass has a molecular structure that is arranged in a regular, three-dimensional manner, so light is reflected at the crystal interfaces, resulting in a loss of transparency. On the other hand, because the molecular structure is arranged in a regular, three-dimensional manner, it has superior thermal shock resistance and mechanical strength compared to amorphous powdered glass. In contrast, amorphous glass powder is transparent. That is, amorphous glass powder has a non-crystalline structure that does not constitute a three-dimensional crystal lattice, so it transmits light. Therefore, since the glass film created in this invention is transparent, amorphous glass powder is used as the glass powder. However, because of its non-crystalline structure, amorphous glass powder is inferior to crystalline powdered glass in terms of thermal shock resistance and mechanical strength. For this reason, a transparent graphene film is firmly bonded to both sides of the transparent glass film, giving the transparent film superior impact strength, bending strength, and compressive strength compared to a metal film of the same thickness. Furthermore, because the transparent graphene film is firmly bonded to both sides of the transparent glass film, the transparent glass film is unaffected by thermal shock even if thermal shock is applied to it. Furthermore, powdered glass is used for three purposes: as a binder, for sealing, and for heat resistance. However, powdered glass used as a binder has relatively small particle size, with over 90% of powdered glass having a central particle size smaller than 10 μm. Since the thickness of the transparent film of the present invention is 20 μm or less, amorphous powdered glass with a central particle size of 5 μm or less is used. In other words, in the second step of paragraph 9, the first suspension is filled into the second container, and then the second container is heated to a temperature higher than the softening point of amorphous powdered glass. As a result, aggregates of amorphous powdered glass, each less than 5 μm in size, precipitate by overlapping at a high density. Subsequently, the amorphous powdered glass softens and then becomes fluid. Furthermore, when the fluidized aggregates of amorphous powdered glass are compressed, the fluidized amorphous powdered glass moves and fills all the voids. Furthermore, the fluidized amorphous powdered glass particles overlap at a high density and join at the contact points, forming a planar glass film. Because the amorphous powdered glass particles are small (less than 5 μm), the bonding force between the amorphous powdered glass particles that overlap at a high density and join at the contact points is large, and the mechanical strength of the resulting planar glass film is high. The softening point of amorphous powdered glass for binders ranges from 390 to 870°C, depending on the composition of the powdered glass. On the other hand, the lower the heat treatment temperature for forming the glass film in the second step of the 9th stage, the lower the cost of forming the glass film. For this reason, amorphous powdered glass with a composition of one of the composite systems consisting of Bi2O3·B2O3, Bi2O3·B2O3·ZnO, or B2O3·V2O5·BaO, which have a softening point lower than 500°C, is used.

[0020] The method for creating a transparent film, which consists of a transparent graphene film in which flattened graphene surfaces are joined together as described in paragraph 9, being bonded to both surfaces of a transparent glass film, is as follows: The alcohol described in paragraph 9, having a viscosity of 2-4 mPa·s at 20°C, is one of the following alcohols: 1-propanol, 2-propanol, 1-butanol, 1-pentanol, or 2-pentanol. This alcohol is used as the alcohol described in paragraph 9, having a viscosity of 2-4 mPa·s at 20°C, and the process in the first step described in paragraph 9 is carried out. A method for creating a transparent film, comprising a transparent graphene film in which flattened graphene surfaces, as described in paragraph 9, are joined together, and then joined to both surfaces of a transparent glass film.

[0021] Alcohols with a viscosity of 2-4 mPa·seconds at 20°C include 1-propanol, 2-propanol, 1-butanol, 1-pentanol, and 2-pentanol. 1-Propanol CH3(CH2)2OH has a viscosity of 1.94 mPa·s at 20°C, a boiling point of 98°C, and a specific gravity of 0.8053 g / cm³. 3 It is a general-purpose alcohol. 2-Propanol (CH3)2CH(OH) has a viscosity of 2.37 mPa·s at 20°C, a boiling point of 82°C, and a specific gravity of 0.785 g / cm³. 3 It is a general-purpose alcohol. 1-Butanol (CH3(CH2)3OH) has a viscosity of 3.0 mPa·s at 20°C, a boiling point of 117°C, and a specific gravity of 0.810 g / cm³. 3 It is a general-purpose alcohol. 1-Pentanol CH3(CH2)4OH has a viscosity of 3.34 mPa·s at 20°C, a boiling point of 138°C, and a specific gravity of 0.814 g / cm³. 3 It is a general-purpose alcohol. 2-Pentanol (CH3(CH2)CH(OH)CH3) has a viscosity of 3.47 mPa·s at 20°C, a boiling point of 119°C, and a specific gravity of 0.812 g / cm³. 3 It is a general-purpose alcohol. These alcohols have a viscosity of 2-4 mPa·s at 20°C, and can therefore be used as alcohols with a viscosity of 2-4 mPa·s at 20°C as described in paragraph 9. They also have a density of 0.8 g / cm³. 3 Because the particles are so small, a first suspension can be prepared in which an aggregate of amorphous glass powder with a central particle size of 5 μm or less is uniformly dispersed in alcohol. [Brief explanation of the drawing]

[0022] [Figure 1] This is a schematic diagram showing a magnified view of the side of the transparent film that was created. [Modes for carrying out the invention]

[0023] Example 1 This embodiment prepares a first suspension in which an aggregate of amorphous powdered glass is dispersed in 1-propanol. As the amorphous powdered glass, we used an amorphous powdered glass (AGC Inc. product DPS315) consisting of a Bi2O3·B2O3·ZnO composite system, which has an extremely small central particle size of 0.7 μm, a high specific gravity of 7.5 among powdered glasses, and a softening point of 493°C. The density of 1-propanol was 0.804 g / cm³. 3 Because it is small and has a low viscosity of 1.9 mPa·s at 20°C, the fine powdered glass is adsorbed onto 1-propanol, and the powdered glass adsorbed onto 1-propanol is evenly dispersed within the 1-propanol. First, 6 g of amorphous glass powder and 80 g of 1-propanol were placed in a container, and the 1-propanol was stirred to disperse the amorphous glass powder within it. The volume of the amorphous glass powder added was 7.5 cm³. 3 This corresponds to 100 cm, and 1-propanol is equivalent to 100 cm 3 It corresponds to this. Next, a container made of S45C carbon steel for machine structures, measuring 20cm x 20cm x 1cm (thickness) and 5mm in depth, was prepared, as well as a plate made of S45C carbon steel for machine structures, measuring 20cm x 20cm x 1cm (thickness). Furthermore, a suspension of amorphous glass powder dispersed in 1-propanol was filled into a container, and the container was heated to 510°C. Next, a plate was placed over the fluidized amorphous glass powder, and nine 5kg weights were placed at equal intervals on the plate. The fluidized amorphous glass powder was compressed for 20 seconds, creating a transparent glass film on the bottom of the container. After this, the weights were removed. Next, an impact acceleration of 0.3G was repeatedly and simultaneously applied to nine equally spaced points on the bottom surface of the container, and the transparent glass film was peeled off the bottom surface of the container. Furthermore, the plate material to which the transparent glass film was bonded was positioned so that the transparent glass film was facing upwards, and an impact acceleration of 0.3G was repeatedly and simultaneously applied to nine equally spaced points on the bottom surface of the plate material, and the transparent glass film was peeled off the plate material. The resulting transparent glass film had a thickness of 20 μm.

[0024] Example 2 This embodiment involves creating a graphene aggregate from a collection of graphite particles and then creating a suspension in which the graphene aggregate is dispersed in 1-propanol. First, 20 liters of 1-propanol were filled into a shallow container with a base measuring 1.2m x 1.2m. Next, a parallel plate electrode was prepared in which the effective electrode area where an electric field is generated in the gap between two parallel plate electrode plates was 1 m × 1 m. Furthermore, 1 g of flake-shaped graphite particles (for example, XD100 from Ito Graphite Industry Co., Ltd.) was spread evenly on the surface of one of the parallel plate electrode plates. Then, the other parallel plate electrode plate was placed on top of it, forming a gap of 100 μm, and the two superimposed parallel plate electrode plates were immersed in 1-propanol via the cluster of graphite particles. After this, a DC voltage of 12 kilovolts was applied between the electrodes. Assuming the graphite particles are spheres with a particle size of 25 μm, and if the graphite particles are evenly packed into the 100 μm gap between two parallel plate electrodes, then 2.6 × 10⁻¹⁰ 8 There are 7.6 × 10⁻¹⁰ graphite particles. When a DC voltage of 10.6 kilovolts or more is applied to this collection of graphite particles, the interlayer bonds at the base of all graphite particles are simultaneously broken. 13 A collection of graphene particles is obtained, using only 4.72g of graphite particles. Next, the gap between the two parallel plate electrodes was widened, and the two parallel plate electrodes were then tilted in 1-propanol. Three-directional vibration accelerations of 0.2G were repeatedly applied to the container, after which the two parallel plate electrodes were removed from the container. After this, the aggregate of graphene dispersed in 1-propanol inside the container was stirred. Next, a portion of the prepared sample was taken out and observed and analyzed using an electron microscope. The electron microscope used was an ultra-low acceleration voltage SEM owned by JFE Techno-Research Corporation. This device allows surface observation using ultra-low acceleration voltages starting from 100V, and enables direct observation of the sample surface without forming a conductive coating. Secondary electron beams between 900 and 1000 volts from the backscattered electron beams on the sample surface were extracted and imaged. The material dispersed in 1-propanol was confirmed to be an extremely thin, flattened substance. Furthermore, image processing of the characteristic X-ray energy and intensity revealed the presence of only carbon atoms. Therefore, the material was confirmed to be graphene. This method involves flatly arranging a collection of flake-like graphite particles in the gap between two parallel plate electrodes, applying a DC potential difference between the electrodes, and generating an electric field in the gap between the electrodes where the collection of flake-like graphite particles is located. This electric field provides a Coulomb force to all the graphite particles that is sufficient to simultaneously break the interlayer bonds of the basal plane made of graphite crystals. As a result, all the interlayer bonds of the graphite crystals are simultaneously broken, and it was confirmed that a basal plane made of graphite crystals, i.e., a collection of graphene, can be produced.

[0025] Example 3 This embodiment uses the suspension prepared in Example 2 to create a transparent film consisting of a transparent graphene film, in which flattened graphene planes are joined together, bonded to both sides of a transparent glass film. First, 10 cc of the suspension in which the graphene aggregate prepared in Example 2 was dispersed in 1-propanol was filled into the container used in Example 1. The container was then placed on the vibration platform of the vibration exciter, and the vibration exciter was operated to repeatedly apply vibration accelerations of 0.4G in three directions: front-to-back, left-to-right, and up-and-down. Next, the transparent glass film prepared in Example 1 was immersed in a container. Furthermore, a plate made of S45C carbon steel for machine structural use, the same size as the transparent glass film and with a thickness of 1 cm, was prepared. Next, the transparent glass film with the suspension attached was removed from the container and placed on top of the plate. Another plate made of S45C carbon steel for machine structural use, the same size as the transparent glass film and with a thickness of 1 cm, was placed on top of the transparent glass film. In this way, the transparent glass film was sandwiched between two plates of the same size as the transparent glass film. Next, the container was heated to 100°C. Then, nine 10kg weights were placed at equal intervals on a plate that had been stacked on top of a transparent glass film, and all the weights were removed from the plate after 20 seconds. Next, impact accelerations of 0.3G were repeatedly and simultaneously applied to nine equally spaced points on the bottom surface of the lower plate, peeling the transparent glass film away from the bottom surface of the lower plate. Finally, another plate to which the transparent glass film was attached was positioned so that the transparent glass film was facing upwards, and impact accelerations of 0.3G were repeatedly and simultaneously applied to nine equally spaced points on the bottom surface of the other plate, peeling the transparent glass film away from the other plate. Furthermore, the sides and surface of the prepared sample were observed using the electron microscope used in Example 2. Observation of the side of the sample revealed that the sample consisted of a transparent glass film with a thickness of 2 μm, and layers with a thickness of 2 nm were formed on both sides. Next, secondary electron beams between 900 and 1000 volts were extracted from the backscattered electron beams from the surface of the sample and image processing was performed. Fine, flattened black material was found to be layered and stacked without gaps. Furthermore, energy between 900 and 1000 volts was extracted from the backscattered electron beams from the surface and image processing was performed to analyze the material composition of the black material based on the density of the image. Since no density variation was observed, it was determined that it was composed of a single atom. Furthermore, the energy and intensity of characteristic X-rays from the surface were image processed to analyze the types of elements that make up the black material. The black material was composed only of carbon atoms. From these results, it was found that the sample was a transparent film consisting of a transparent glass film with a thickness of 2 μm bonded to both sides, with a transparent graphene film with a thickness of 2 nm. Figure 1 shows a magnified schematic of the side view of the transparent film. 1 is the transparent glass film, and 2 is the transparent graphene film. The visible light transmittance was measured at multiple points on the created transparent film (for example, using a PT-50 measuring instrument manufactured by Komei Rikagaku Kogyo). The total light transmittance of the created transparent film was approximately 85%, indicating transparency close to that of clear glass. Next, the surface resistance at multiple points on the surface of the transparent film was measured using a surface resistance meter (for example, a ST-4 surface resistance meter manufactured by Simco Japan Co., Ltd.). The surface resistance values ​​were all 1 × 10⁻⁶. 3The resistance was less than Ω / □. Therefore, the surface resistance of the transparent film is lower than that of the metal. Furthermore, the thermal conductivity of multiple points on the film was measured using a transient method called periodic heating. A thermal conductivity of around 1800 W / mK was obtained, indicating that the transparent film has a thermal conductivity close to that of graphene. In addition, the transparent film was repeatedly dropped from a height of 4m, but there was no damage whatsoever to the surface or sides of the transparent film, indicating that the transparent film possesses greater impact strength, bending strength, and compressive strength than the metal film. Furthermore, when water was dropped onto the surface of the transparent film, all the water was repelled, and when the transparent film was tilted, all the water fell off, and no water droplets remained, indicating that the surface of the transparent film has water-repellent and stain-resistant properties. [Explanation of Symbols]

[0026] 1. Transparent glass film 2. Transparent graphene film

Claims

1. A method for creating a transparent film, comprising a transparent graphene film in which flattened graphene planes are joined together, and a transparent graphene film being joined to both surfaces of a transparent glass film, is: The first step involves weighing amorphous glass powder in a weight corresponding to the thickness and size of the transparent glass film to be created, and placing the amorphous glass powder into a first container; further, adding alcohol having a viscosity of 2-4 mPa·s at 20°C, with a viscosity corresponding to the size of the amorphous glass powder and a weight of at least 10 times the weight of the amorphous glass powder placed in the first container, to the first container, stirring the alcohol, and creating a first suspension in which the aggregate of amorphous glass powder is dispersed in the alcohol; A second container is prepared, the size of which matches the size of the transparent glass film to be created, and the depth of the container is 1 cm or less. A first plate material is prepared, the size of which matches the size of the transparent glass film to be created. The first suspension is filled into the second container. After this, the second container is heated to a temperature higher than the softening point of the amorphous powdered glass, and the first suspension filled in the second container is transformed into an aggregate of fluidized amorphous powdered glass. Furthermore, the first plate material is placed over the surface of the aggregate of fluidized amorphous powdered glass, and a compressive load is applied evenly to the entire surface of the first plate material. As a result, the fluidized amorphous powdered glass moves and fills all the voids, and furthermore, the fluidized amorphous powdered glass comes into contact with each other. A second step in creating a transparent glass film is performed, comprising the following steps:

1. A planar, transparent glass film is formed on the bottom surface of the second container by friction welding, and 2. An impact acceleration of the same magnitude is repeatedly applied simultaneously to multiple locations on the bottom surface of the second container to peel the transparent glass film away from the bottom surface of the second container.

3. The first plate material to which the transparent glass film is joined is positioned so that the transparent glass film faces upward, and an impact acceleration of the same magnitude applied to the second container is repeatedly applied simultaneously to multiple locations on the bottom surface of the first plate material to peel the transparent glass film away from the first plate material. On the surface of one of two parallel plate electrode plates of the same size, an aggregate of flake-shaped graphite particles or an aggregate of lumpy graphite particles is spread evenly, and the one parallel plate electrode plate on which the aggregate of flake-shaped graphite particles or the aggregate of lumpy graphite particles is spread is immersed in 1-propanol filled in a third container, and the other parallel plate electrode plate is then placed on top of the one parallel plate electrode plate, and the aggregate of flake-shaped graphite particles or the The two parallel plate electrodes are separated by a predetermined gap between them via an aggregate of lumpy graphite particles, and the two parallel plate electrodes separated by the predetermined gap are immersed in 1-propanol. After this, a DC potential difference of a predetermined size is applied to the gap between the two parallel plate electrodes, thereby generating an electric field equivalent to the value obtained by dividing the magnitude of the potential difference by the size of the gap between the two parallel plate electrodes, which is then applied to the scales packed in the gap between the two parallel plate electrodes. A mixture of flaky graphite particles or a mixture of lumpy graphite particles is subjected to a process that simultaneously destroys all interlayer bonds of the basal surface forming the flaky or lumpy graphite particles, causing a mass of graphene corresponding to the basal surface to precipitate simultaneously in the gap between the two parallel plate electrodes. After this, the gap between the two parallel plate electrodes is widened, the two parallel plate electrodes are tilted in the 1-propanol, and the third container is subjected to vibration in three directions: front-to-back, left-to-right, and up-and-down. A third step to create a graphene aggregate from a graphite particle aggregate and a second suspension in which the graphene aggregate is dispersed in 1-propanol, comprising repeatedly applying velocity to move the graphene aggregate from the gap between the two parallel plate electrode plates into the 1-propanol, and creating a second suspension in which the graphene aggregate is dispersed in the 1-propanol, and further removing the two parallel plate electrode plates from the third container, A fourth step is to create a third suspension in which the flattened surfaces of graphene overlap via 1-propanol, and this suspension is created by filling the second container used in the second step with the second suspension in an amount corresponding to the size and thickness of the transparent graphene film to be bonded to both sides of the transparent glass film created in the second step, then placing the second container on the vibration platform of a vibration machine, operating the vibration machine, and repeatedly applying vibration acceleration in three directions (front-back, left-right, up-down) to the second container, thereby creating a third suspension in which the flattened surfaces of graphene overlap via 1-propanol. A fifth step involves immersing the transparent glass film prepared in the second step in the third suspension in the second container, thereby adhering the third suspension to both sides of the transparent glass film. A second plate material is prepared, having the same size as the transparent glass film created in the second step. The transparent glass film, having the third suspension attached to both sides, created in the fifth step, is placed on top of the second plate material. Furthermore, a third plate material, having the same size as the transparent glass film created in the second step, is placed on top of the transparent glass film, having the third suspension attached to both sides. After this, the transparent glass film, having the third suspension attached to both sides, sandwiched between the second and third plates, is heated to a temperature above the boiling point of 1-propanol, vaporizing the 1-propanol from the third suspension attached to both sides of the transparent glass film, and converting the third suspension attached to both sides of the transparent glass film into an aggregate of graphene with overlapping flattened surfaces. Furthermore, the entire surface of the third plate material is compressed, thereby compressing the aggregate of graphene with overlapping flattened surfaces. A transparent graphene film having a thickness of 2 nm or less is formed by friction welding two flat surfaces together, and then the transparent graphene film is bonded to both surfaces of the transparent glass film by friction welding, thereby creating a transparent film having a configuration in which the transparent graphene film is bonded to both surfaces of the transparent glass film. Subsequently, an impact acceleration of the same magnitude is repeatedly and simultaneously applied to multiple locations on the bottom surface of the second plate material to peel the transparent film from the bottom surface of the second plate material. Furthermore, the third plate material to which the transparent film is bonded is positioned so that the transparent film is facing upwards, and an impact acceleration of the same magnitude as that applied to the second plate material is repeatedly and simultaneously applied to multiple locations on the bottom surface of the third plate material to peel the transparent film from the third plate material. This process constitutes a sixth step in creating a transparent film having a configuration in which the transparent graphene film is bonded to both surfaces of the transparent glass film. A method for creating a transparent film in which a transparent graphene film, in which flattened graphene sheets are bonded together, is bonded to both surfaces of a transparent glass film, by performing all of these six processes in sequence.

2. A method for creating a transparent film comprising a transparent graphene film in which flattened graphene surfaces as described in claim 1 are joined together and bonded to both surfaces of a transparent glass film, is: The amorphous powdered glass described in claim 1 is amorphous powdered glass having a central particle size of 5 μm or less and a softening point lower than 500°C, and the amorphous powdered glass is used as the amorphous powdered glass described in claim 1, and the processing in the first step, the second step, the fifth step, and the sixth step described in claim 1 are carried out. A method for creating a transparent film comprising a transparent graphene film, in which flattened graphene surfaces as described in claim 1 are joined together, and a transparent graphene film being joined to both surfaces of a transparent glass film.

3. A method for creating a transparent film comprising a transparent graphene film in which flattened graphene surfaces as described in claim 1 are joined together and bonded to both surfaces of a transparent glass film, is: The alcohol described in claim 1, having a viscosity of 2-4 mPa·s at 20°C, is one of 1-propanol, 2-propanol, 1-butanol, 1-pentanol, or 2-pentanol, and the process in the first step described in claim 1 is carried out using this one alcohol as the alcohol described in claim 1, having a viscosity of 2-4 mPa·s at 20°C. A method for creating a transparent film comprising a transparent graphene film, in which flattened graphene surfaces as described in claim 1 are joined together, and a transparent graphene film being joined to both surfaces of a transparent glass film.

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