Gass-barrier coating body

Abstract

To provide a gas-barrier coating body capable of heightening a gas barrier performance preventing permeation of a gas through a base material to a performance exceeding that of a blocking film unit by a synergic effect of the graphene and the blocking film.SOLUTION: A lamination film 14 has graphene 16 laminated on a surface 121 of a base material 12, and a blocking film 18 laminated on the graphene 16 on the side opposite to the side of the base material 12, and the blocking film 18 makes the gas barrier performance of the lamination film 14 heightened when compared with a case in which the blocking film 18 is laminated on the surface 121 without disposing the graphene 16, and with a case in which the graphene 16 is laminated on the surface 121 without disposing the blocking film 18. Therefore, it is possible to heighten the gas barrier performance to the performance exceeding the performance of the blocking film 18 alone due to the synergistic effect of the graphene 16 and the blocking film 18 laminated on each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to gas barrier coatings that prevent gas transmission. [Background technology]

[0002] Patent Document 1 describes a touch panel. The touch panel of Patent Document 1 includes a structure in which a plurality of insulating films and a film containing graphene are formed on a substrate. One of the insulating films has a function of blocking oxygen, hydrogen, water, alkali metals, alkaline earth metals, and the like. It is said that the provision of the insulating film can prevent hydrogen, water, and the like from entering the semiconductor film on the substrate from the outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-137085 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the touch panel of Patent Document 1, the blocking function that prevents the permeation of hydrogen and the like is realized by the barrier effect of the insulating film alone. Therefore, the gas barrier performance that prevents the permeation of gases such as hydrogen does not exceed the performance of the insulating film alone.

[0005] In addition, when looking at graphene, the graphene that is actually obtained has crystal defects such as grain boundaries and cracks, and gases such as hydrogen permeate through the crystal defects in graphene alone. The inventors have found the above as a result of detailed studies.

[0006] In view of the above, an object of the present disclosure is to provide a gas barrier coated body that can improve the gas barrier performance of preventing gas permeation into a substrate to a level exceeding that of the blocking film alone, by using a synergistic effect between graphene and a blocking film. [Means for solving the problem]

[0007] In order to achieve the above object, a gas barrier coating according to one aspect of the present disclosure comprises: A substrate (12) having one surface (121); A laminated coating (14) having graphene (16) laminated on one surface and a blocking film (18) laminated on the opposite side of the graphene from the substrate side, The blocking film enhances the performance of the laminate coating to prevent gas from passing through the substrate, as compared with either a case in which a blocking film is laminated on one surface without providing graphene or a case in which graphene is laminated on one surface without providing a blocking film.

[0008] In this way, the synergistic effect of the stacked graphene and blocking film can improve the gas barrier performance beyond that of the blocking film alone.

[0009] In addition, in each section of the application documents, each element may be given a reference number in parentheses. In this case, the reference number merely indicates an example of the correspondence between the element and the specific configuration described in the embodiment described later. Therefore, the present disclosure is not limited in any way by the description of the reference number. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a gas barrier coating body in a first embodiment. [Diagram 2] 1 is a table summarizing the configuration of each sample used in a performance test carried out to evaluate the gas barrier performance of the gas barrier coating body of the first embodiment. [Diagram 3]3 is a graph showing the results of a performance test carried out using each sample in FIG. 2, the graph showing the hydrogen permeability coefficient of each sample. [Figure 4] FIG. 3 is a perspective view that illustrates a schematic configuration of a comparative sample 2, which is one of the samples in FIG. 2 and in which only graphene is formed as a coating on a substrate, and corresponds to FIG. [Diagram 5] FIG. 11 is a perspective view showing a schematic diagram of a tank having a gas barrier coating in a second embodiment. [Figure 6] 6 is a cross-sectional view showing a schematic cross section taken along line VI-VI of FIG. 5 in the second embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a schematic cross section taken along line VII-VII of FIG. 6 in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, each embodiment will be described with reference to the drawings. In the following embodiments, the same reference numerals are given to parts that are the same or equivalent to each other.

[0012] (First embodiment) As shown in Fig. 1, the gas barrier coating 10 of this embodiment is formed into a film having a thickness in a predetermined thickness direction. The gas barrier coating 10 has a gas barrier function that prevents gases such as hydrogen from permeating through the gas barrier coating 10. The gas barrier coating 10 includes a substrate 12 and a laminated coating 14, and is configured as a laminated structure in which the substrate 12 and the laminated coating 14 are laminated. The lamination direction Ds in which the substrate 12 and the laminated coating 14 are laminated coincides with the thickness direction of the gas barrier coating 10.

[0013] The substrate 12 is made of a film-like resin material, specifically, made of PET. PET is an abbreviation for polyethylene terephthalate. The substrate 12 has a thickness in the stacking direction Ds, and the thickness of the substrate 12 is 250 μm. The substrate 12 has one surface 121 provided on one side of the stacking direction Ds and another surface 122 provided on the other side of the stacking direction Ds. There is no limitation on the shape of the substrate 12, but the substrate 12 of this embodiment is formed in a flat plate shape.

[0014] The laminate coating 14 is provided to enhance the gas barrier performance, which prevents gases such as hydrogen from permeating the substrate 12, compared to the substrate 12 alone. The laminate coating 14 has graphene 16 and a blocking film 18, which are coatings stacked on top of each other.

[0015] Graphene 16 is a coating made of carbon atoms bonded in a sheet shape. Graphene 16 is stacked on one surface 121 of substrate 12 and bonded to the one surface 121. Therefore, graphene 16 is in contact with one surface 121 of substrate 12 from one side in the stacking direction Ds.

[0016] For example, one layer of graphene 16 is formed by CVD transfer, and the grain size of the graphene 16 is about 20 μm. CVD transfer is one of the methods for forming a film of graphene 16. Specifically, CVD transfer is a method for forming a film by forming graphene 16 by CVD on a surface of a substrate different from the substrate 12, and transferring the graphene 16 formed on the substrate to one surface 121 of the substrate 12. CVD is an abbreviation for Chemical Vapor Deposition.

[0017] Furthermore, the graphene 16 is not a perfect crystal without defects 16a, but has crystal defects 16a such as grain boundaries and cracks.

[0018] The blocking film 18 is a coating made of a metal oxide, specifically, a coating made of aluminum oxide. Since the blocking film 18 is made of aluminum oxide, it is also an insulating film with electrical insulation properties. An example of the aluminum oxide that constitutes the blocking film 18 is Al2O3. The thickness of the blocking film 18 in this embodiment is preferably 80 nm or less, and more preferably 40 nm or less.

[0019] The blocking film 18 is stacked on the side opposite to the substrate 12 side with respect to the graphene 16, i.e., on one side in the stacking direction Ds, and is joined to the graphene 16. Therefore, the blocking film 18 is in contact with the graphene 16 from one side in the stacking direction Ds.

[0020] Specifically, the blocking film 18 is formed on the graphene 16 by ALD. ALD is an abbreviation for Atomic Layer Deposition. In FIG. 1, the blocking film 18 is shown by a two-dot chain line for easy viewing.

[0021] In addition, the blocking film 18 spreads over the entire surface of the graphene 16 and is therefore bound to the crystal defects 16a of the graphene 16. In other words, the blocking film 18 fills the crystal defects 16a of the graphene 16 and covers the defects 16a from one side in the stacking direction Ds.

[0022] The laminate coating 14 has a multilayer structure composed of the graphene 16 and the blocking film 18 as described above, and covers the entire one surface 121 of the substrate 12. In concrete terms, the substrate coverage rate Rc of the laminate coating 14 is "Rc>95%". The substrate coverage rate Rc is the rate at which the coating on the one surface 121 of the substrate 12 covers the one surface 121 of the substrate 12, relative to the entire one surface 121 of the substrate 12. In this embodiment, the coating on the one surface 121 is the laminate coating 14.

[0023] Next, a performance test conducted to evaluate the gas barrier performance of the gas barrier coated body 10 of this embodiment will be described. As shown in Fig. 2, in this performance test, working samples 1 and 2 having the configuration of the present disclosure and comparative samples 1, 2 and 3 for comparison with working samples 1 and 2 were prepared. The configurations of working samples 1 and 2 and comparative samples 1, 2 and 3 will be described later, but the points of those configurations that are not mentioned in the following description are the same as the configuration of the gas barrier coated body 10 of this embodiment described above.

[0024] All of the working samples 1 and 2 and the comparative samples 1, 2, and 3 are configured to include the same substrate 12, and the substrate 12 of each sample is PET having a thickness of 250 μm.

[0025] Comparative sample 1 is composed of only the substrate 12, and does not have the graphene 16 or the blocking film 18. Comparative sample 2 has the substrate 12 and the graphene 16, but does not have the blocking film 18. In other words, comparative sample 2 has a configuration in which the blocking film 18 is removed from the configuration of the gas barrier coating body 10 of the present embodiment, which has the substrate 12, graphene 16, and blocking film 18.

[0026] Comparative sample 3 has substrate 12 and blocking film 18, but does not have graphene 16. That is, comparative sample 3 has a configuration in which blocking film 18 is laminated on one surface 121 of substrate 12 and bonded to one surface 121.

[0027] Since the working samples 1 and 2 are samples having the configuration of the present disclosure, they have the same configuration as the gas barrier coating body 10 of the above-described embodiment. That is, the working samples 1 and 2 have a substrate 12, graphene 16, and blocking film 18 stacked in the stacking direction Ds. However, the thickness of the blocking film 18 differs between the working samples 1 and 2, as will be described later.

[0028] In each of the comparative sample 2 and the working samples 1 and 2 having the graphene 16, the graphene 16 is formed in one layer by CVD transfer. The grain size of the graphene 16 in each sample is about 20 μm.

[0029] In each of Comparative Sample 3 and Experimental Samples 1 and 2, which have a blocking film 18, the blocking film 18 is made of aluminum oxide and is deposited by ALD. The thickness of the blocking film 18 in Comparative Sample 3 and Experimental Sample 1 is 80 nm, and the thickness of the blocking film 18 in Experimental Sample 2 is 40 nm.

[0030] In addition, the substrate coverage rate Rc of the coating is "Rc>95%" in each of Comparative Samples 2 and 3 and Experimental Samples 1 and 2. In each of Comparative Samples 2 and 3 and Experimental Samples 1 and 2, it can be said that the coating on one surface 121 of the substrate 12 essentially covers the entire surface 121.

[0031] FIG. 3 shows the results of a performance test in which the gas permeability in the stacking direction Ds was measured using the above-mentioned comparative samples 1, 2, and 3 and practical samples 1 and 2. The gas used in this performance test was hydrogen. As shown in FIG. 3, the results of the performance test for each sample showed that the magnitude of the hydrogen permeability coefficient was in the order of "comparative sample 1 ≒ comparative sample 2>comparative sample 3> practical samples 1 and 2". This hydrogen permeability coefficient represents the ease of permeation of hydrogen gas, and the larger the hydrogen permeability coefficient, the easier the hydrogen gas permeates. In other words, the smaller the hydrogen permeability coefficient, the higher the gas barrier performance that prevents hydrogen gas from permeating the substrate 12.

[0032] Therefore, from the results of this performance test, it can be said that the gas barrier performance of the experimental samples 1 and 2 is the highest, and the order is "Experimental samples 1 and 2 > Comparative sample 3 > Comparative sample 2 ≒ Comparative sample 1." In other words, in terms of the order of the layered structures, the gas barrier performance is in the order of "Substrate 12 + graphene 16 + blocking film 18 > Substrate 12 + blocking film 18 > Substrate 12 + graphene 16 ≒ Substrate 12 only." Note that, although hydrogen gas was used in this performance test, it is presumed that the order of high and low gas barrier performance would not change even if the gas used in the performance test was replaced from hydrogen to other gases such as oxygen, nitrogen, or air.

[0033] As can be seen from the performance test results for comparative sample 1 and comparative sample 3, blocking film 18, which is formed as a coating on substrate 12, exhibits higher gas barrier performance than substrate 12 alone, regardless of the presence or absence of graphene 16.

[0034] In addition, although the comparative sample 2 has graphene 16 provided as a coating on the substrate 12, the gas barrier performance of the comparative sample 2 is substantially the same as that of the comparative sample 1. The reason for this is believed to be as follows. That is, as shown in Fig. 4, the crystals of the graphene 16 themselves do not allow gas to pass through, but defects 16a in the crystals of the graphene 16 allow gas to pass through. Note that "H2" shown in Fig. 4 and Fig. 1 represents hydrogen gas, and the dotted hatched "x" marks are schematic representations of how gas permeation is prevented.

[0035] On the other hand, it was confirmed that the working samples 1 and 2 had high gas barrier performance not only in comparison with the comparative sample 1 but also in comparison with the comparative samples 2 and 3. This is believed to be because the blocking film 18 formed by ALD on the graphene 16 of the working samples 1 and 2 binds to the defects 16a in the crystals of the graphene 16 and fills in the defects 16a. In the working samples 1 and 2, the defects 16a in the crystals of the graphene 16 are filled in by the blocking film 18, and it is believed that the working samples 1 and 2 exhibit performance close to the gas barrier performance that the graphene 16 crystals inherently have.

[0036] 3, the following can be said about the gas barrier coating 10 of this embodiment shown in FIG. 1. That is, as can be seen from a comparison between the working samples 1 and 2 and the comparative sample 2, the blocking film 18 of this embodiment improves the gas barrier performance of the laminate coating 14 compared to a case where the blocking film 18 is not provided and the graphene 16 is laminated on the one surface 121 of the substrate 12. And, as can be seen from a comparison between the working samples 1 and 2 and the comparative sample 3, the blocking film 18 of this embodiment improves the gas barrier performance of the laminate coating 14 even compared to a case where the graphene 16 is not provided and the blocking film 18 is laminated on the one surface 121 of the substrate 12.

[0037] In short, the blocking film 18 of the present embodiment enhances the gas barrier performance of the laminate coating 14, compared to a case in which the laminate coating 14 laminated on one surface 121 of the substrate 12 is composed of only one of the graphene 16 and the blocking film 18.

[0038] 1 , the laminate coating 14 has graphene 16 laminated on one surface 121 of the substrate 12, and a blocking film 18 laminated on the side opposite the substrate 12 side with respect to the graphene 16. The blocking film 18 enhances the gas barrier performance of the laminate coating 14, compared with either the case where the graphene 16 is not provided and the blocking film 18 is laminated on the one surface 121, or the case where the graphene 16 is not provided and the blocking film 18 is laminated on the one surface 121.

[0039] Therefore, the synergistic effect of the graphene 16 and the blocking film 18 stacked on each other can improve the gas barrier performance to a level exceeding that of the blocking film 18 alone. In other words, it is possible to achieve gas barrier performance that cannot be achieved by a configuration in which a single film, that is, the graphene 16 or the blocking film 18, is formed on the substrate 12.

[0040] (1) Furthermore, according to this embodiment, as shown in Figure 1, the laminate coating 14 covers the entirety of one surface 121 of the substrate 12. Therefore, when the gas barrier coating body 10 constitutes a product such as a container, the gas barrier performance of the product can be sufficiently ensured.

[0041] (2) According to this embodiment, the graphene 16 contains crystal defects 16a. Therefore, it is possible to obtain high gas barrier performance by using practical graphene 16.

[0042] (3) Furthermore, according to this embodiment, the blocking film 18 is bonded to the crystal defects 16a of the graphene 16. This prevents gas permeation not only in the areas of the graphene 16 that do not have the crystal defects 16a but also in the areas of the graphene 16 that have the crystal defects 16a, as shown in Fig. 1. As a result, it is possible to exhibit gas barrier performance that cannot be achieved by a configuration in which a single film, that is, the graphene 16 or the blocking film 18, is formed on the substrate 12.

[0043] (4) Furthermore, according to this embodiment, the thickness of the blocking film 18 is preferably 80 nm or less, as in the working sample 1 of Fig. 2. This ensures the flexibility of the gas barrier coated body 10 while maintaining the gas barrier performance. Furthermore, when the gas barrier coated body 10 is bent, it is possible to suppress a decrease in the gas barrier performance caused by, for example, an increase in the crystal lattice spacing or the effect of strain of the graphene 16 due to stress.

[0044] More preferably, the thickness of the blocking film 18 is 40 nm or less, as in the working sample 2 of Fig. 2. In this way, the flexibility of the gas barrier coated body 10 can be improved compared to, for example, a case where the thickness of the blocking film 18 exceeds 40 nm, while maintaining the gas barrier performance. For confirmation, when the thickness of the blocking film 18 is set to 40 nm or less or 80 nm or less as described above, if a lower limit of the thickness of the blocking film 18 is to be specified, the thickness would be greater than zero.

[0045] (5) Furthermore, according to the present embodiment, the blocking film 18 is a coating formed by ALD. Therefore, it is easy to form the blocking film 18 on the graphene 16 while bonding the blocking film 18 to the defects 16a in the crystals of the graphene 16. In addition, it is possible to densely and thoroughly fill the defects 16a in the crystals of the graphene 16 with the blocking film 18.

[0046] Second embodiment Next, a second embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described. Also, parts that are the same as or equivalent to the above-mentioned embodiment will be omitted or simplified. This also applies to the following embodiments.

[0047] 5 to 7, the gas barrier coating 10 of this embodiment is provided as a wall that forms the outer shell of a tank 40. Thus, the substrate 12 and the laminate coating 14 constitute the wall of the tank 40. The gas barrier coating 10 serves as the wall of the tank 40, separating the outside of the tank 40 from an internal tank space 40a formed inside the tank 40.

[0048] The tank internal space 40a is an enclosed space, and a gas such as hydrogen is sealed in the tank internal space 40a.

[0049] 1, the inside of the tank 40 corresponds to one side of the stacking direction Ds, and the outside of the tank 40 corresponds to the other side of the stacking direction Ds. That is, one surface 121 of the substrate 12 in this embodiment faces the inside of the tank 40. Then, the graphene 16 is stacked on the inside of the tank 40 with respect to the substrate 12, and the blocking film 18 is stacked on the inside of the tank 40 with respect to the graphene 16. The blocking film 18 faces the tank internal space 40a.

[0050] For example, the thickness of the blocking film 18 in this embodiment is 40 nm. By reducing the thickness of the blocking film 18, there is an advantage that the gas barrier coating body 10 can be easily curved.

[0051] The tank 40 has a cylindrical shape that extends in one direction D1 and has both ends closed. Therefore, one surface 121 of the substrate 12 is a curved surface, and the laminated coating 14 is formed along the curved surface 121.

[0052] (1) As described above, according to this embodiment, one surface 121 of the substrate 12 of the gas barrier coating 10 is a curved surface. Therefore, it is possible to use the gas barrier coating 10, which has gas barrier properties, in a sealed container such as the tank 40 of this embodiment. Furthermore, the gas barrier coating 10 makes it possible to obtain sufficient gas barrier properties in the sealed container.

[0053] (2) Furthermore, according to this embodiment, the substrate 12 constitutes a wall that forms the tank 40 in which gas is sealed, and one surface 121 of the substrate 12 faces the inside of the tank 40. Therefore, since the laminate coating 14 is formed on the inside of the tank 40 relative to the substrate 12, it is possible to increase the airtightness of the tank internal space 40a by the gas barrier performance of the gas barrier coating body 10. In other words, it is possible to sufficiently ensure the gas barrier performance of the gas barrier coating body 10 that prevents the gas sealed in the tank internal space 40a from leaking out of the tank 40.

[0054] Except for the points described above, this embodiment is similar to the first embodiment. In this embodiment, the same effects as those of the first embodiment can be obtained from the configuration common to the first embodiment.

[0055] (Other embodiments) (1) In each of the above-described embodiments, the substrate 12 of the gas barrier coating 10 is made of PET, but the material of the substrate 12 is not limited to PET and may be various polymers other than PET. For example, the material of the substrate 12 may be polycarbonate or polyimide. There is also no limitation on the thickness of the substrate 12.

[0056] (2) In each of the above-described embodiments, graphene 16 is formed in one layer by CVD transfer, but the method of forming graphene 16 is not limited to this. For example, graphene 16 may be formed by applying a graphene solvent onto one surface 121 of substrate 12 by spin coating or the like. In addition, graphene 16 is not limited to one layer and may be formed in multiple layers.

[0057] (3) In each of the above-described embodiments, the coating between the substrate 12 and the blocking film 18 is graphene 16. However, the coating may be a two-dimensional material other than graphene 16, such as h-BN or MoS2, which is similar to graphene 16.

[0058] (4) In each of the above-described embodiments, the blocking film 18 of the gas barrier coating body 10 is made of aluminum oxide, but the constituent material of the blocking film 18 is not limited to aluminum oxide, and may be various metal oxides other than aluminum oxide. For example, the blocking film 18 may be a coating made of a metal oxide such as titanium oxide or zirconium oxide. Furthermore, it is also envisioned that the blocking film 18 may be a coating made of an inorganic or organic material other than a metal oxide.

[0059] (5) In each of the above-described embodiments, the blocking film 18 is formed on the graphene 16 by ALD, but the method of forming the blocking film 18 is not limited to this. For example, the blocking film 18 may be formed on the graphene 16 by CVD or PVD. PVD is an abbreviation for Physical Vapor Deposition.

[0060] (6) In each of the above-described embodiments, as shown in FIG. 1, the blocking film 18 is stacked on one side of the graphene 16 in the stacking direction Ds and covers the graphene 16 over the entire surface of the graphene 16, but this is just one example. It is also possible that the blocking film 18 covers only part of the graphene 16 rather than the entire surface of the graphene 16. As an extreme example, it is also possible that the blocking film 18 covers part or all of the defective portion of the graphene 16 having the crystal defects 16a, but does not cover the non-defective portion of the graphene 16 having no crystal defects 16a.

[0061] (7) Note that the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms. Furthermore, it goes without saying that the elements constituting the embodiments in the above-described embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0062] In addition, in each of the above embodiments, when the numbers, values, amounts, ranges, and other numerical values ​​of the components of the embodiments are mentioned, they are not limited to the specific numbers, except when it is particularly clearly stated that they are essential or when they are clearly limited to a specific number in principle, etc. In addition, in each of the above embodiments, when the materials, shapes, positional relationships, and the like of the components are mentioned, they are not limited to the materials, shapes, positional relationships, and the like, except when it is particularly clearly stated or when they are clearly limited to a specific material, shape, positional relationship, and the like in principle. [Explanation of symbols]

[0063] 10 Gas barrier coating 12 Base material 14 Laminated coating 16. Graphene 18 Blocking membrane 121 one side

Claims

1. A gas barrier coating comprising: A substrate (12) having one surface (121); a laminated coating (14) having graphene (16) laminated on the one surface and a blocking film (18) laminated on the opposite side of the graphene from the substrate side; The gas barrier coated body, wherein the blocking film enhances the performance of the laminate coating to prevent gas from passing through the base material, as compared with either a case in which the graphene is not provided and the blocking film is laminated on the one surface, or a case in which the graphene is not provided and the blocking film is laminated on the one surface.

2. The gas barrier coated body according to claim 1 , wherein the laminate coating covers the entire one surface.

3. The gas barrier coating according to claim 1 or 2, wherein the graphene contains crystal defects (16a).

4. The gas barrier coating according to claim 3 , wherein the blocking film is bonded to defects in the graphene crystals.

5. 3. The gas barrier coated body according to claim 1, wherein the blocking film has a thickness of 80 nm or less.

6. 3. The gas barrier coated body according to claim 1, wherein the blocking film is a coating formed by ALD.

7. The gas barrier coated body according to claim 1 , wherein one surface of the substrate is a curved surface.

8. The substrate constitutes a wall forming a tank (40) in which the gas is sealed; The gas barrier coating according to claim 1 or 2, wherein one surface of the substrate faces the inside of the tank.

Images