Method for producing a film structure and film structure

Abstract

A coated structure manufacturing method according to the present invention is for manufacturing a coated structure having a metal-carbon composite coating on a carbon base material, and comprises: an application step for applying a metal compound-containing substance on the carbon base material; and a heating step for heating the carbon base material having undergone the applying, to form a metal-carbon composite coating on the carbon base material. A coated structure according to the present invention is obtained by forming a metal-carbon composite coating on a carbon base material. The metal-carbon composite coating is formed by heating a metal compound-containing substance applied on the carbon base material.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a film structure and a film structure.

Background Art

[0002] For members that require heat resistance and reaction resistance (e.g., oxidation resistance and chemical resistance), the heat resistance and reaction resistance can be improved and the life of the member can be extended by forming a protective film such as a metal compound on the surface of the base material.

[0003] For example, when forming a tantalum carbide layer as a protective film on the surface of a carbon base material, it is common to use a CVD apparatus as disclosed in Patent Document 1.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the size and shape of the base material on which a protective film can be formed are predetermined for each CVD apparatus, and depending on the size and shape of the base material, it was not possible to form a protective film on its surface. In addition, the process of forming a protective film on the surface of the base material using a CVD apparatus took a considerably long time.

[0006] In view of the above problems, the present invention provides a method for manufacturing a film structure and a film structure regardless of the size and shape of the base material.

Means for Solving the Problems

[0007] The manufacturing method of the coating structure of the present invention made to solve the above problems is a manufacturing method of a coating structure having a metal-carbon composite coating on a carbon substrate, comprising: a coating step of applying a metal compound-containing substance on the carbon substrate; and a heating step of forming a metal-carbon composite coating on the carbon substrate by heating the coated carbon substrate. In the present specification, the "metal-carbon composite coating" may be one in which a metal carbide alone or a carbon-containing material containing a metal carbide exists in a state where a metal element and a carbon element are bonded in the coating. Further, in the coating, a metal compound other than the metal carbide may be dispersed in the carbon-containing material, that is, it may exist in a state of being mixed or dispersed, rather than in a state where the metal element and the carbon element are bonded. Examples of the metal compound other than the metal carbide include metal oxides, metal nitrides, metal sulfides, and metal hydroxides.

[0008] Here, the coating structure manufactured by the manufacturing method of the coating structure of the present invention has a metal-carbon composite coating on a carbon substrate. For example, it may have a metal-carbon composite coating on at least one surface (e.g., the surface) of the carbon substrate, or on the entire circumferential surface of the carbon substrate. Further, it also includes those having a metal-carbon composite coating on a part of one surface of the carbon substrate.

[0009] First, in the coating step according to the manufacturing method of the coating structure of the present invention, a metal compound-containing substance is applied on the carbon substrate.

[0010] The carbon substrate used in the manufacturing method of the coating structure of the present invention may be a substrate made of only carbon, a substrate having carbon as a main component and a carbon content of 50% by mass or more, or a multi-layer structure in which the outermost layer is a substrate made of only carbon or having carbon as a main component and a carbon content of 50% by mass or more. It is particularly preferable that the carbon substrate is a substrate made of only carbon.

[0011] In addition, the size and shape of the carbon base material are not particularly limited as long as they can be heated in a stationary furnace used in the heating process described later. Specifically, examples of the carbon base material include crucibles, furnace materials, electrodes, fibers, filtration devices, filters, protective tubes, heater tubes, burner nozzles, refractory jigs, and the like.

[0012] Examples of the carbon material of the carbon base material include fullerene, carbon nanotube, carbon nanofiber, graphene, graphene oxide, carbon nanohorn, diamond, hyperdiamond, carbon fiber, and the like.

[0013] Further, the carbon material may consist of only carbon or other materials containing carbon. Furthermore, as the structure of the carbon material, it may have a uniform tissue structure or a non-uniform tissue structure. Note that as the uniform tissue structure, it may be hollow or porous. Also, as the non-uniform tissue structure, for example, it may be sea-island shaped, multi-layered, hollow, or porous.

[0014] Furthermore, the shape of the carbon material may be in the form of powder, plate, film, fiber, etc., and these molded bodies, that is, mixtures, multi-layers, compacted powders, sintered bodies, fiber bundles, non-woven fabrics, woven fabrics (plain weave, twill weave, satin weave, basket weave) may also be used.

[0015] The carbon material is preferably a fibrous material in particular. Specifically, examples include metal fibers (such as steel fibers), ceramic fibers (such as metal oxide fibers, metal carbide fibers, metal nitride fibers, silicon carbide fibers, glass fibers), and polymer fibers (such as natural polymer fibers, polysaccharide fibers, cellulose fibers, artificial polymer fibers, resin fibers, carbon fibers).

[0016] In addition, the metal compound-containing substance used in the method for manufacturing the coating structure of the present invention is characterized by containing a compound of at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si. Examples of the metal compound-containing material include those containing a compound of at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si. Specifically, peroxo complex metal compounds containing at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si (for example, peroxohydroxy acid complex metal compounds, peroxocitric acid complex metal compounds, peroxoammonium complex metal compounds), metal hydroxides, hydroxy acid complex metal compounds (for example, ammonium oxalate complex metal compounds), polyacids, etc. can be mentioned, but it is not limited to these compounds. Further, the metal compound-containing material may contain a metal element other than at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si, a metalloid element, or a non-metal element. For example, B, P, etc. can be mentioned.

[0017] When the metal compound-containing material is a peroxo complex metal compound, even if it is a carbon-free substrate, by heating the substrate coated with the peroxo complex metal compound, the metal element contained in the peroxo complex metal compound reacts with carbon to form a metal carbide. Also, when the metal compound-containing material is a hydroxy acid complex metal compound, similarly, the metal element contained in the hydroxy acid complex metal compound reacts with carbon to form a metal carbide.

[0018] The content of the metal compound-containing material is preferably adjusted according to the type of the metal element and the carbon substrate, more preferably more than 0 mass% and 40 mass% or less, still more preferably 0.1 mass% or more and 30 mass% or less, particularly preferably 0.2 mass% or more and 30 mass% or less, and also particularly preferably 0.3 mass% or more and 15 mass% or less. When the metal compound-containing material contains a plurality of metal elements selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si, the total value of each mass fraction is preferably within the above-mentioned numerical range.

[0019] Here, the content of the metal compound inclusion may be appropriately diluted with dilute hydrochloric acid as needed, and the mass fraction in terms of metal may be measured and calculated in accordance with JIS K0116:2014 using ICP emission spectrometry (manufactured by Agilent Technologies: AG-5110).

[0020] In addition, the content of the compound of at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si in the metal compound inclusion used in the method for producing the film structure of the present invention is characterized in that it is more than 0% by mass and 35% by mass or less in terms of metal. The content of the compound of at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si in the metal compound inclusion is preferably adjusted according to the type of the metal element and the carbon-based substrate, more preferably more than 0% by mass and 35% by mass or less in terms of metal, still more preferably 0.03% by mass or more and 25% by mass or less, particularly preferably 0.06% by mass or more and 25% by mass or less, and most preferably 0.1% by mass or more and 15% by mass or less. When the metal compound inclusion contains a plurality of metal elements selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si, the total value of the mass fractions in terms of each metal is preferably within the above numerical range. In this specification, "in terms of metal" means conversion in terms of Ti for Ti, Nb for Nb, Mo for Mo, Hf for Hf, Ta for Ta, W for W, Zr for Zr, and Si for Si. Further, the metal compound inclusion may contain a metal element other than at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si, a metalloid element, or a non-metal element. For example, B, P, etc. may be mentioned.

[0021] In addition, the metal compound inclusion used in the method for producing the film structure of the present invention is characterized by containing a Ta compound. When the metal compound-containing material contains a Ta compound, it is preferable in that it reacts with carbon contained on the carbon base material and the carbonization reaction easily proceeds. Specifically, examples of the Ta compound include tantalum peroxo citrate compounds, tantalum hydroxide, and polyoxotantalates.

[0022] When the metal compound-containing material is a tantalum peroxo citrate compound, even in the case of a base material not containing carbon, by heating the base material coated with the tantalum peroxo citrate compound, tantalum and carbon contained in the tantalum peroxo citrate compound react to form tantalum carbide.

[0023] Furthermore, when the metal compound-containing material is tantalum hydroxide, the tantalum concentration in the metal compound-containing material may typically be 5 mass% or more and 30 mass% or less, 5 mass% or more and 25 mass% or less, 5 mass% or more and 20 mass% or less, 5 mass% or more and 15 mass% or less, or 5 mass% or more and 10 mass% or less.

[0024] Here, when the metal compound-containing material is tantalum hydroxide, the tantalum content in the metal compound-containing material is appropriately diluted with dilute hydrochloric acid as necessary, and in accordance with JIS K0116:2014, using ICP emission analysis (manufactured by Agilent Technologies: AG-5110), the tantalum mass fraction in terms of tantalum is measured and calculated.

[0025] Moreover, the metal compound-containing material used in the method for manufacturing the coating structure of the present invention may contain a resin. When the metal compound-containing material contains a resin, it is preferable in that the resin is uniformly compatible with the metal compound and functions to adhere to the carbon base material, thereby improving the film-forming property and adhesion to the carbon base material.

[0026] Examples of the resin contained in the metal compound-containing material include polyolefin-based compounds and vinyl-based compounds.

[0027] Further, in the metal compound-containing material used in the method for producing the coating structure of the present invention, when the metal compound-containing material is 100% by mass, the resin content may be 0.1% by mass or more and 60% by mass or less. When the resin content in the metal compound-containing material of the present invention is 0.1% by mass or more and 60% by mass or less, it is preferable in that it can suppress the aggregation of fine metal compounds after drying or can improve the wettability of the metal compound-containing material to the carbon substrate. The resin content may be 0.15% by mass or more and 40% by mass or less, may be 0.2% by mass or more and 30% by mass or less, or may be 0.25% by mass or more and 20% by mass or less.

[0028] Further, the metal compound-containing material used in the method for producing the coating structure of the present invention may contain at least one surfactant selected from the group consisting of nonionic surfactants, cationic surfactants, and anionic surfactants as the surfactant. Examples of the surfactant include olefin resins having an amine group, a carboxyl group, a hydroxyl group, phosphoric acid, a sulfone group, or an unsaturated fatty acid in the functional group on the side chain, acetylene glycol compounds, polyoxyalkylene, polyoxyethylene, polyoxypropylene, and the like.

[0029] Further, in the metal compound-containing material used in the method for producing the coating structure of the present invention, when the metal compound-containing material is 100% by mass, the surfactant content may be 0.001% by mass or more and 10% by mass or less. When the resin content in the metal compound-containing material of the present invention is 0.001% by mass or more and 10% by mass or less, it is preferable in that it can improve the wettability of the metal compound-containing material to the substrate. The resin content may be 0.01% by mass or more and 5% by mass or less, may be 0.05% by mass or more and 3% by mass or less, or may be 0.1% by mass or more and 1% by mass or less.

[0030] Further, the metal compound-containing material used in the method for producing the coating structure of the present invention may contain a carbon material. When the metal compound-containing material contains a carbon material, the carbon material becomes a carbonization component during carbonization, which is preferable in terms of improving carbonization.

[0031] Furthermore, the metal compound-containing material used in the method for producing the coating structure of the present invention may be a solution, sol, or gel. The metal compound-containing material contains a metal compound, and more specifically, it may be any material that liquefies when a shear stress is applied. That is, the metal compound-containing material includes those in a liquid state, sol state, gel state, or semi-solid state under normal conditions, as long as it can be applied onto a carbon base material. Furthermore, the gel may have a viscosity of 200 mPa·s or more by the rotating cylinder method at 25°C.

[0032] Also, when the metal compound-containing material used in the method for producing the coating structure of the present invention is a solution, it can be easily applied onto a carbon base material, which is preferable. Furthermore, when the metal compound-containing material used in the method for producing the coating structure of the present invention contains water as a solvent, it is preferable from the viewpoint of reducing environmental load.

[0033] In addition, the metal compound-containing material used in the method for producing the coating structure of the present invention is characterized in that the maximum value of the light transmittance in the wavelength range of 500 nm to 700 nm is 70%T or more. When the metal compound-containing material used in the method for producing the coating structure of the present invention has a maximum value of the light transmittance in the wavelength range of 500 nm to 700 nm of 70%T or more, it is preferable in terms of high dispersibility and excellent uniformity of the components in the liquid. It is more preferable that the maximum value of the light transmittance in the wavelength range of 500 nm to 700 nm is 72%T or more, further preferable that it is 74%T or more, particularly preferable that it is 76%T or more, also particularly preferable that it is 78%T or more, and even more particularly preferable that it is 80%T or more. The light transmittance in the wavelength range of 500 nm to 700 nm may be 80%T. Although the measured value of the light transmittance may exceed 100%T due to measurement errors or the like, since the theoretical upper limit value is 100%T, when the measured value exceeds 100%T, it is regarded as 100%T.

[0034] Here, the light transmittance in the wavelength range of 500 nm to 700 nm is measured using a spectrophotometer according to the following light transmittance measurement conditions for the metal compound inclusion used in the method for producing the film structure of the present invention.

[0035] =Light transmittance measurement conditions= · Measuring device: UV-visible near-infrared spectrophotometer UH4150 type (manufactured by Hitachi High-Tech Science Corporation) · Measurement mode: Wavelength scan · Data mode: %T (transmission) · Measurement wavelength range: 200 nm to 2000 nm · Scan speed: 600 nm / min · Sampling interval: 2 nm

[0036] On the other hand, when the metal compound inclusion used in the method for producing the film structure of the present invention contains a Si compound, the light transmittance in the wavelength range of 500 nm to 700 nm is obtained by measuring the ultraviolet-visible absorption spectrum (UV-Vis absorption spectrum) in accordance with JIS K 0115, 2004 "General Rules for Absorption Photometric Analysis Methods" by putting 3 g of the metal compound inclusion containing the Si compound adjusted to room temperature (25 °C) into a measuring cell (optical path length 1 cm) and according to the following light transmittance measurement conditions (including Si).

[0037] =Light transmittance measurement conditions (including Si)= · Measuring device: U-2900 type spectrophotometer (manufactured by Hitachi High-Tech Corporation) · Measurement mode: Wavelength scan · Data mode: %T (transmission) · Measurement wavelength range: 200 nm to 1000 nm · Scan speed: 200 nm / min · Sampling interval: 1 nm · Cell length: 10 mm · Measuring cell: Particle size disposable angle cell (manufactured by Otsuka Electronics Co., Ltd.)

[0038] In addition, the metal compound inclusion used in the method for producing the coating structure of the present invention is characterized in that the particle diameter (D50) of the particles in the metal compound inclusion in the dynamic light scattering method is 3000 nm or less. When the particle diameter (D50) of the particles in the metal compound inclusion used in the method for producing the coating structure of the present invention is 3000 nm or less, it is preferable from the viewpoint of stability over time, more preferably 2000 nm or less, and may be 1000 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 100 nm or less, 50 nm or less, 30 nm or less, 20 nm or less, 10 nm or less, 5 nm or less, 3 nm or less, 2 nm or less. On the other hand, the particle diameter (D50) is preferably 0.1 nm or more, more preferably 0.5 nm or more, further preferably 0.7 nm or more, and particularly preferably 1 nm or more. Typically, the particle diameter (D50) is 0.6 nm or more and 200 nm or less.

[0039] Here, the dynamic light scattering method is a method of measuring the light scattering intensity from a group of Brownian-moving particles by irradiating light such as laser light onto a solution such as a suspension solution, and obtaining the particle diameter and distribution from the temporal variation of the intensity. Specifically, the method for evaluating the particle size distribution is carried out in accordance with JIS Z 8828:2019 "Particle Size Analysis - Dynamic Light Scattering Method" using a zeta potential, particle size, and molecular weight measurement system (manufactured by Otsuka Electronics Co., Ltd.: ELSZ-2000ZS). Further, if necessary, a sample diluted 1000-fold with pure water is used as the measurement sample, and in order to remove dust etc. in the measurement sample immediately before measurement, the measurement sample is filtered through a filter with a pore diameter of 11 μm, and ultrasonic treatment is carried out for 3 minutes with an ultrasonic cleaner (manufactured by AS ONE Corporation: VS-100III). Furthermore, the liquid temperature of the measurement sample is adjusted to 25°C. Note that the particle diameter (D50) refers to the median diameter (D50) that indicates the 50% integrated value of the cumulative distribution curve.

[0040] In addition, the metal compound inclusion used in the method for producing the coating structure of the present invention is characterized in that the pH is 6.5 or more and 13.5 or less. When the pH of the metal compound inclusion used in the method for producing the coating structure of the present invention is 6.5 or higher, it is preferable in terms of good solubility. It is more preferable that the pH of the metal compound inclusion is 7.0 or higher, still more preferable that it is 7.5 or higher, and particularly preferable that it is 8.0 or higher. The pH of the metal compound inclusion may be 8.5 or higher, 9.0 or higher, 9.5 or higher, 10.0 or higher, 10.5 or higher, or 11.0 or higher. On the other hand, it is preferable that the pH of the metal compound inclusion is 13.5 or lower, more preferable that it is 13.0 or lower, and still more preferable that it is 12.5 or lower.

[0041] Here, the measurement of the pH of the metal compound inclusion used in the method for producing the coating structure of the present invention is carried out after immersing the electrode (HORIBA: Standard ToupH electrode 9615S-10D) of a pH meter (HORIBA: Glass electrode type hydrogen ion concentration indicator D-51) in the metal compound inclusion and confirming that the liquid temperature has stabilized at 25°C.

[0042] And in the coating step according to the method for producing the coating structure of the present invention, the metal compound inclusion is applied onto the above-described carbon substrate by the following coating method.

[0043] Specific examples of the method for applying the metal compound inclusion onto the carbon substrate include spraying, inkjet, dispenser, nozzle coating, slit coating, die coating, roll coating, spin coating, blade coating, knife coating, wire bar coating, screen printing, brush painting, and the like.

[0044] Next, in the heating step according to the method for producing the coating structure of the present invention, by heating the carbon substrate coated with the metal compound inclusion, a metal-carbon composite coating is formed on the carbon substrate. By heating the carbon substrate coated with the metal compound inclusion, the metal compound inclusion reacts with the carbon contained in the carbon substrate, that is, undergoes a carbonization reaction, thereby forming a metal-carbon composite coating on the carbon substrate.

[0045] Specifically, a carbon substrate coated with a metal compound-containing material is placed in a stationary furnace and heated in an inert atmosphere, for example, an argon atmosphere or a nitrogen atmosphere. By this, the metal element in the metal compound-containing material reacts (carbonization reaction) with the carbon present on the coated surface of the carbon substrate coated with the metal compound-containing material, thereby forming a metal carbide and forming a metal-carbon composite film on the carbon substrate. Further, the heating step may be under reduced pressure or under vacuum. Here, it is preferable that the heating temperature in the heating step is 1000°C or higher and 3500°C or lower, and the heating time is 0.5 hour or longer and 2 hours or shorter.

[0046] Further, when the metal compound-containing material is a peroxo complex metal compound, by heating a carbon substrate coated with the peroxo complex metal compound, the metal element contained in the peroxo complex metal compound reacts with carbon to form a metal carbide, and a metal-carbon composite film can be formed on the carbon substrate.

[0047] When the heating temperature in the heating step is 1000°C or higher and 3500°C or lower, it is preferable in that the carbon of the carbon substrate and the metal compound surely react. It is more preferable that the heating temperature in the heating step is 1400°C or higher and 2000°C or lower, further preferably 1500°C or higher and 1900°C or lower, and particularly preferably 1550°C or higher and 1800°C or lower.

[0048] When the heating time in the heating step is 0.5 hour or longer and 2 hours or shorter, it is preferable in that the carbide is sufficiently synthesized. It is more preferable that the heating time in the heating step is 1 hour or longer and 1.5 hours or shorter, and further preferably 1.2 hours or longer and 1.4 hours or shorter.

[0049] Further, the method for manufacturing the film structure of the present invention may further include a drying step between the coating step and the heating step of the method for manufacturing the film structure of the present invention described above.

[0050] It is preferable that a carbon substrate coated with a metal compound inclusion is placed in a stationary furnace and dried at a drying temperature of 100 °C for 1 hour, because excess impurities such as moisture can be removed.

[0051] The drying temperature in the drying process is more preferably 110 °C or higher and 400 °C or lower, further preferably 120 °C or higher and 300 °C or lower, and particularly preferably 130 °C or higher and 200 °C or lower.

[0052] The drying time in the drying process is preferably 0.2 hours or more and 3 hours or less, more preferably 0.3 hours or more and 2 hours or less, and further preferably 0.4 hours or more and 1 hour or less.

[0053] Furthermore, the method for manufacturing the film structure of the present invention may include a step of cooling the formed metal-carbon composite film by a heating step. The formed metal-carbon composite film may be cooled to room temperature by the heating step.

[0054] Specifically, a film structure having a metal-carbon composite film formed on a carbon substrate is taken out of a stationary furnace and cooled to room temperature.

[0055] By the method for manufacturing the film structure of the present invention described above, a film structure having a metal-carbon composite film formed on a carbon substrate can be manufactured.

[0056] The method for manufacturing the film structure of the present invention is not limited to the above-described manufacturing method, and may be the following manufacturing method.

[0057] The method for manufacturing the film structure of the present invention is a method for manufacturing a film structure having a metal-carbon composite film on a carbon substrate, and includes an immersion step of immersing the carbon substrate in a metal compound inclusion, and heating the immersed carbon substrate to form a metal-carbon composite film on the carbon substrate. The carbon base material and the metal compound inclusion used in the method for manufacturing the coating structure of the present invention are the same as those used in the method for manufacturing the coating structure of the present invention described above, and thus detailed description thereof is omitted.

[0058] First, in the dipping step according to the method for manufacturing the coating structure of the present invention, the carbon base material is dipped into the metal compound inclusion.

[0059] Specifically, by dipping the carbon base material into a container filled with the metal compound inclusion, the carbon base material is impregnated with the metal compound inclusion. Also, the dipping time in the dipping step is preferably 0.1 hour or more and 1 hour or less, and more preferably 0.2 hour or more and 0.9 hour or less. Note that the dipping step may be performed at room temperature, or may be heated and then cooled to room temperature.

[0060] Further, in the dipping step according to the method for manufacturing the coating structure of the present invention, when the carbon base material is dipped with the metal compound inclusion under reduced pressure or under vacuum, the carbon base material is more easily impregnated with the metal compound inclusion, and the dipping time in the dipping step can be shortened, which is preferable.

[0061] Specifically, by putting the container filled with the metal compound inclusion in which the carbon base material is dipped into a decompression device and reducing the pressure or evacuating, the carbon base material is more easily impregnated with the metal compound inclusion.

[0062] The degree of vacuum in the decompression device is preferably 0.05 MPa or less, more preferably 0.04 MPa or less, further preferably 0.03 MPa or less, and particularly preferably 0.02 MPa or less. Also, the dipping time in the dipping step under reduced pressure or under vacuum is preferably 0.1 hour or more and 0.5 hour or less, and more preferably 0.2 hour or more and 0.4 hour or less.

[0063] Furthermore, when forming a metal-carbon composite film on only one surface of the carbon base material, for example, only the surface, the surface of the carbon base material is immersed in the metal compound-containing material. On the other hand, when forming a metal-carbon composite film on the entire circumferential surface of the carbon base material, the entire circumferential surface of the carbon base material is immersed in the metal compound-containing material.

[0064] Next, in the heating step according to the method for manufacturing the film structure of the present invention, by heating the carbon base material impregnated with the metal compound-containing material, a metal-carbon composite film is formed on the carbon base material. By heating the carbon base material impregnated with the metal compound-containing material, the metal element in the metal compound-containing material reacts (carbonization reaction) with the carbon present in the carbon base material impregnated with the metal compound-containing material to form a metal carbide, and a metal-carbon composite film is formed on the carbon base material.

[0065] Here, when the metal compound-containing material is a peroxo-citric acid metal compound, by heating the carbon base material impregnated with the peroxo-citric acid metal compound, the metal element contained in the peroxo-citric acid metal compound reacts with carbon to form a metal carbide, and a metal-carbon composite film can be formed on the carbon base material.

[0066] The heating step according to the method for manufacturing the film structure of the present invention is characterized in that it is 1000°C or higher and 3500°C or lower, and the heating time is 0.5 hours or longer and 2 hours or shorter.

[0067] When the heating temperature in the heating step is 1000°C or higher and 3500°C or lower, it is preferable in that the carbon of the carbon base material and the metal compound surely react. More preferably, the heating temperature in the heating step is 1400°C or higher and 2000°C or lower, still more preferably 1500°C or higher and 1900°C or lower, and particularly preferably 1550°C or higher and 1800°C or lower.

[0068] When the heating time in the heating step is 0.5 hours or longer and 2 hours or shorter, it is preferable in that the carbide is sufficiently synthesized. More preferably, the heating time in the heating step is 1 hour or longer and 1.5 hours or shorter, and still more preferably 1.2 hours or longer and 1.4 hours or shorter.

[0069] Further, the method for manufacturing the coating structure of the present invention may further include a drying step between the dipping step and the heating step of the method for manufacturing the coating structure of the present invention described above.

[0070] Placing the carbon substrate impregnated with the metal compound inclusion in a stationary furnace and drying at a drying temperature of 100 ° C for 1 hour is preferable in that excess impurities such as moisture can be removed.

[0071] The drying temperature in the drying step is more preferably 110 ° C or higher and 400 ° C or lower, further preferably 120 ° C or higher and 300 ° C or lower, and particularly preferably 130 ° C or higher and 200 ° C or lower.

[0072] The drying time in the drying step is preferably 0.2 hours or more and 3 hours or less, more preferably 0.3 hours or more and 2 hours or less, and further preferably 0.4 hours or more and 1 hour or less.

[0073] Furthermore, the method for manufacturing the coating structure of the present invention may include a step of cooling the formed metal-carbon composite coating by a heating step. It is preferable to cool the formed metal-carbon composite coating to room temperature by a heating step.

[0074] The metal-carbon composite coating formed on the carbon substrate manufactured by the method for manufacturing the coating structure of the present invention described above may be in a state where a metal element and carbon are present. Preferably, the metal element is more than 0% by mass and 80% by mass or less, and carbon is more than 0% by mass and 50% by mass or less. The mass fractions of the metal element and carbon in the metal-carbon composite coating can be measured, for example, in a substrate cross-section sample, by semi-quantitative analysis using energy dispersive X-ray analysis (EDX) or the like for the metal-carbon composite coating portion.

[0075] In addition, while a large amount of metal elements are present on the surface of the metal-carbon composite film, the proportion of carbon derived from the carbon substrate is higher closer to the carbon substrate. When a metal compound inclusion is applied, metal elements are likely to be present on the surface of the metal-carbon composite film. On the other hand, when the metal-carbon composite film is impregnated with a metal compound inclusion, the proportion of metal elements is relatively higher inside the metal-carbon composite film compared to when it is applied.

[0076] Further, regarding the metal-carbon composite film formed on the carbon substrate produced by the method for manufacturing the film structure of the present invention, from the peaks of the X-ray diffraction pattern obtained by performing X-ray diffraction measurement according to the following X-ray diffraction measurement conditions and X-ray diffraction analysis conditions, it can be confirmed that it is a carbide.

[0077] =X-ray Diffraction Measurement Conditions= · Equipment: MiniFlexII (manufactured by Rigaku Corporation) · Measurement range (2θ): 5 to 90° · Sampling width: 0.02° · Scan speed: 2.0° / min · X-ray: CuKα ray · Voltage: 30 kV · Current: 15 mA · Divergence slit: 1.25° · Scattering slit: 1.25° · Receiving slit: 0.3 mm

[0078] =X-ray Diffraction Analysis Conditions= · Use the data analysis software PDXL2 manufactured by Rigaku Corporation. · Smooth the peak with b-spline to clarify the peak top.

[0079] Furthermore, when the thickness of the metal-carbon composite film formed on the carbon substrate produced by the method for manufacturing the coating structure of the present invention is 300 nm or less, it is preferable in that cracks in the film and peeling of the film itself are less likely to occur. The thickness of the metal-carbon composite film may be 100 nm or less. This is because when cracks occur in the metal-carbon composite film, the carbon substrate oxidizes and is likely to be released as carbon dioxide, and the carbon in the carbon substrate is likely to decrease. On the other hand, when the thickness of the metal-carbon composite film is 1 nm or more, it is preferable in that the carbon substrate can be sufficiently protected. The thickness of the metal-carbon composite film may be 10 nm or more.

[0080] Moreover, the coating structure of the present invention is a coating structure in which a metal-carbon composite film is formed on a carbon substrate, and the metal-carbon composite film is formed by heating the carbon substrate coated or impregnated with a metal compound-containing substance. The coating structure of the present invention can improve heat resistance and reactivity and extend the life of the carbon substrate by having a metal-carbon composite film formed on the carbon substrate regardless of the size and shape of the carbon substrate. Also, the coating structure of the present invention has a metal-carbon composite film with a uniform thickness on the carbon substrate regardless of the size and shape of the carbon substrate.

[0081] Furthermore, when the thickness of the metal-carbon composite film formed on the carbon substrate of the present invention is 300 nm or less, it is preferable in that cracks in the film and peeling of the film itself are less likely to occur.

[0082] Moreover, the metal compound-containing substance for the metal-carbon composite film of the present invention is a metal compound-containing substance for the metal-carbon composite film formed on the carbon substrate, and is characterized by reacting with the carbon substrate to form a metal-carbon composite film. The metal compound inclusion for the metal-carbon composite coating of the present invention is applied to or immersed in a carbon substrate, and by heating the carbon substrate, the metal element in the metal compound inclusion reacts (carbonization reaction) with the carbon present on the coated surface of the carbon substrate to which the metal compound inclusion is applied, thereby forming a metal carbide and forming a metal-carbon composite coating.

[0083] By forming a metal-carbon composite coating on the carbon substrate, it is possible to improve the corrosion resistance against the following liquids and gases. Specifically, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, sodium chloride, acetic acid, oxalic acid, aqueous ammonia, sodium hydroxide, potassium hydroxide, water vapor, hydrogen sulfide gas, ammonia gas, hydrogen gas, fluorine gas, chlorine gas, nitrogen oxide gas (NOx), or sulfur oxide gas (SOx), etc. can be mentioned.

[0084] In addition, the metal compound inclusion for the metal-carbon composite coating of the present invention includes those containing a compound of at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si. Specifically, peroxo complex metal compounds containing at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si (for example, peroxohydroxy acid complex metal compounds, peroxocitric acid complex metal compounds, peroxoammonium complex metal compounds), metal hydroxides, hydroxy acid complex metal compounds (for example, ammonium oxalate complex metal compounds), polyacids, etc. can be mentioned, but it is not limited to these compounds. Further, the metal compound inclusion may contain a metal element other than at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si, a metalloid element, or a non-metal element. For example, B, P, etc. can be mentioned.

[0085] When the metal compound inclusion for the metal-carbon composite coating of the present invention is a peroxo complex metal compound, even on a carbon-free substrate, by heating the substrate coated with the peroxo complex metal compound, the metal element and carbon contained in the peroxo complex metal compound react to form a metal carbide. Further, when the metal compound inclusion is a hydroxy acid complex metal compound, similarly, the metal element and carbon contained in the hydroxy acid complex metal compound react to form a metal carbide.

[0086] Furthermore, when the metal compound inclusion for the metal-carbon composite coating of the present invention contains a Ta compound, it is preferable in that it reacts with the carbon contained on the carbon substrate and the carbonization reaction easily proceeds. Specifically, examples of the Ta compound include tantalum peroxo citrate compound, tantalum hydroxide, and polyoxotantalate.

[0087] When the metal compound inclusion for the metal-carbon composite coating of the present invention is a tantalum peroxo citrate compound, even on a carbon-free substrate, by heating the substrate coated with the tantalum peroxo citrate compound, tantalum and carbon contained in the tantalum peroxo citrate compound react to form tantalum carbide.

[0088] In addition, when the metal compound inclusion for the metal-carbon composite coating of the present invention contains a resin, it is preferable in that the resin is uniformly compatible with the metal compound and functions to adhere to the carbon substrate, thereby improving the film-forming property and adhesion to the carbon substrate. Specifically, examples of the resin contained in the metal compound inclusion include polyolefin-based compounds and polyvinyl-based compounds.

[0089] Furthermore, the metal compound inclusion for the metal-carbon composite coating of the present invention may be a solution, sol, or gel. The metal compound inclusion contains a metal compound, and more specifically, it may be any substance that liquefies when a shear stress is applied. That is, the metal compound inclusion includes those in a liquid state, sol state, gel state, or semi-solid state under normal conditions, as long as it can be applied onto a carbon substrate.

[0090] Further, when the metal compound inclusion for the metal-carbon composite film of the present invention is a solution, it can be easily applied onto the carbon substrate, which is preferable. Furthermore, when the metal compound inclusion for the metal-carbon composite film of the present invention contains water as a solvent, it is preferable from the viewpoint of reducing the environmental load.

[0091] Also, when the maximum value of the light transmittance in the wavelength range of 500 nm to 700 nm of the metal compound inclusion for the metal-carbon composite film of the present invention is 70%T or more, it is preferable in terms of high dispersibility and excellent uniformity of the components in the liquid. The maximum value of the light transmittance in the wavelength range of 500 nm to 700 nm is more preferably 72%T or more, further preferably 74%T or more, particularly preferably 76%T or more, also particularly preferably 78%T or more, and even more particularly preferably 80%T or more. The light transmittance in the wavelength range of 500 nm to 700 nm may be 80%T.

[0092] Also, when the particle diameter (D50) of the particles in the metal compound inclusion in the dynamic light scattering method of the metal compound inclusion for the metal-carbon composite film of the present invention is 3000 nm or less, it is preferable from the viewpoint of stability over time, more preferably 2000 nm or less, and may be 1000 nm or less, 500 nm or less, 400 nm or less, or 300 nm or less. On the other hand, the particle diameter (D50) is preferably 0.1 nm or more, more preferably 0.5 nm or more, further preferably 0.7 nm or more, and particularly preferably 1 nm or more. Typically, the particle diameter (D50) is 0.6 nm or more and 200 nm or less.

[0093] In addition, when the pH of the metal compound inclusion for the metal-carbon composite coating of the present invention is 6.5 or higher, it is preferable in terms of good solubility. It is more preferable that the pH of the metal compound inclusion is 7.0 or higher, further preferably 7.5 or higher, and particularly preferably 8.0 or higher. The pH of the metal compound inclusion may be 8.5 or higher, 9.0 or higher, 9.5 or higher, 10.0 or higher, 10.5 or higher, or 11.0 or higher. On the other hand, it is preferable that the pH of the metal compound inclusion is 13.5 or lower, more preferably 13.0 or lower, and further preferably 12.5 or lower.

[0094] In addition, the metal compound inclusion for the metal-carbon composite coating of the present invention may contain components other than the components derived from the metal compound (referred to as "other components") as long as the effects thereof are not inhibited. Examples of the other components include Li, Mg, Si, Ca, Ti, Mn, Ni, Cu, Zn, Sr, Zr, Mo, Ba, W, Bi, B, etc. However, it is not limited thereto. The content of the other components in the metal compound inclusion is preferably less than 5% by mass, more preferably less than 4% by mass, and further preferably less than 3% by mass. Note that the metal compound inclusion is not intended to contain inevitable impurities, and the content of the inevitable impurities is preferably less than 0.01% by mass.

[0095] In addition, in this specification, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "more preferably greater than X" or "more preferably less than Y" together with the meaning of "X or more and Y or less". Further, when expressed as "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), it also includes the intention of "preferably greater than X" or "preferably less than Y".

Advantages of the Invention

[0096] The manufacturing method of the coating structure of the present invention can manufacture a coating structure having a uniform metal-carbon composite coating on a carbon substrate regardless of the size and shape of the substrate.

Brief Description of the Drawings

[0097]

Figure 1

Figure 2

Figure 3

Best Mode for Carrying Out the Invention

[0098] Hereinafter, the coating structure of the embodiment according to the present invention will be further described with the following examples. However, the following examples do not limit the present invention.

[0099] (Example 1) A peroxotantalum citrate solution was applied to the entire surface of a carbon base material (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) using a brush (the coating amount was 0.0075 g). Next, the carbon base material coated with the peroxotantalum citrate solution was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Then, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. And by cooling to room temperature, the coating structure according to Example 1 was obtained.

[0100] The peroxotantalum citrate solution used in Example 1 was obtained as follows.

[0101] 200 g of tantalum hydroxide and 92 g of 25% by mass aqueous ammonia were stirred and mixed for 10 minutes to obtain a first mixed solution. Then, 220 g of 35% by mass hydrogen peroxide solution was further added to the first mixed solution, and the mixture was stirred for 10 minutes to obtain a second mixed solution. Then, 79 g of citric acid was added to the second mixed solution, and the mixture was stirred for 10 minutes to obtain the tantalum peroxocitrate solution used in Example 1. Here, the tantalum concentration of the tantalum peroxocitrate solution used in Example 1 was 18% in terms of Ta2O5 and 14.3% in terms of Ta.

[0102] The tantalum peroxocitrate solution used in Example 1 was a clear solution without precipitation immediately after its production, and was also a clear solution without precipitation 7 days after production. Also, the Ta2O5 - equivalent concentration of the tantalum peroxocitrate solution used in Example 1 7 days after production was 175 g / L. Furthermore, the average particle diameter of the tantalum peroxocitrate solution used in Example 1 7 days after production by the dynamic light scattering method was 625.2 nm.

[0103] On the other hand, as the carbon base material used in Example 1, an extruded carbon base material (manufactured by Tokyo Carbon Industry Co., Ltd., Furafite flat extruded material) was used. Note that it is not limited to extrusion molding.

[0104] (Example 2) The tantalum peroxocitrate solution was applied to the entire surface of a carbon base material (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) using a brush. Next, the carbon base material coated with the tantalum peroxocitrate solution was placed in an electric furnace and dried in an electric furnace heated to 110°C for 10 minutes. The tantalum peroxocitrate solution was again applied to the entire surface of the dried carbon base material using a brush, and then the process of drying in an electric furnace heated to 110°C for 10 minutes was repeated 2 more times. That is, the process of applying the tantalum peroxocitrate solution to the carbon base material and drying was repeated 3 times in total (the total coating amount for all 3 times was 0.0225 g). Then, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. And by cooling to room temperature, a film structure according to Example 2 was obtained.

[0105] Since the tantalum peroxocitrate solution used in Example 2 is the same as the tantalum peroxocitrate solution used in Example 1, a detailed description thereof will be omitted. Further, since the carbon substrate used in Example 2 is the same as the carbon substrate used in Example 1, a detailed description thereof will be omitted.

[0106] (Example 3) An aqueous solution of tantalum acid (including resin) was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) using a brush (the coating amount was 0.0075 g). Next, the carbon substrate coated with the aqueous solution of tantalum acid (including resin) was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Then, it was heated for 1 hour in an electric furnace heated to 1500°C under an Ar atmosphere. And by cooling to room temperature, a film structure according to Example 3 was obtained.

[0107] The aqueous solution of tantalum acid (including resin) used in Example 3 was obtained as follows.

[0108] 137.9 g of tantalum hydroxide (Ta2O5 concentration 66 mass%) manufactured by Mitsui Mining & Smelting Co., Ltd. was dissolved in 120 g of a 55 mass% hydrofluoric acid aqueous solution, and 849 mL of ion-exchanged water was added to obtain an aqueous solution of tantalum fluoride (Ta2O5 concentration 8.2 mass%).

[0109] To 1,000 g of this aqueous solution of tantalum fluoride, 27.5 g of hydrogen peroxide solution (H2O2 concentration 35 mass%) was added (H2O2 / Ta molar ratio = 0.76), and it was stirred for 5 minutes to obtain an aqueous solution of a tantalum compound.

[0110] 1,000 g of this aqueous solution of the tantalum compound was added to 6.82 L of aqueous ammonia (NH3 concentration 25 mass%) in less than 10 minutes (NH3 / Ta molar ratio = 245, NH3 / HF molar ratio = 30.7) to obtain a reaction solution (pH 11). This reaction solution was a slurry of a tantalum acid compound hydrate, in other words, a slurry of a tantalum-containing precipitate.

[0111] Next, this reaction solution was decanted using a centrifuge and washed until the amount of free fluoride ions became 100 mg / L or less to obtain a tantalum-containing precipitate from which the fluoride ions were removed. At this time, aqueous ammonia was used as the washing solution.

[0112] Furthermore, the tantalum-containing precipitate from which the fluoride ions were removed was diluted with pure water to obtain a tantalum-containing precipitate slurry. A part of this tantalum-containing precipitate slurry was dried at 110 °C for 24 hours and then calcined at 1000 °C for 4 hours to produce Ta2O5, and the Ta2O5 concentration contained in the tantalum-containing precipitate slurry was calculated from its weight.

[0113] Thereafter, the tantalum-containing precipitate slurry diluted with pure water, 5% by mass of dimethylamine as an organic nitrogen compound, and pure water were mixed so that the tantalum concentration of the final mixture was 5% by mass in terms of Ta2O5 and the weight ratio of Ta2O5 / organic nitrogen compound was 1.0, thereby obtaining an aqueous tantalum acid solution. The pH of the aqueous tantalum acid solution was 12.0.

[0114] Then, a polyolefin-based polymer copolymer neutralization salt (Zexcen A manufactured by Sumitomo Seika Chemicals Co., Ltd.) was added to the obtained aqueous tantalum acid solution and stirred at 25 °C for 30 minutes to obtain the aqueous tantalum acid solution (containing resin) used in Example 3. Here, the tantalum concentration of the aqueous tantalum acid solution (containing resin) used in Example 3 was 5% in terms of Ta2O5 and 4.1% in terms of Ta. The content of the resin component contained in the aqueous tantalum acid solution (containing resin) used in Example 3 was 0.025% by mass when the aqueous tantalum acid solution was 100% by mass.

[0115] Here, the added polyolefin-based polymer copolymer neutralization salt was weighed so that when the total polyolefin-based polymer copolymer neutralization salt was 100% by mass, the resin component was 25% by mass, the aqueous ammonia was less than 1% by mass, and the balance was pure water.

[0116] On the other hand, since the carbon substrate used in Example 3 is the same as the carbon substrate used in Example 1, detailed description thereof is omitted.

[0117] (Example 4) An aqueous tantalum acid solution (including resin) was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) using a brush. Next, the carbon substrate coated with the aqueous tantalum acid solution (including resin) was placed in an electric furnace, and dried for 10 minutes in an electric furnace heated to 110°C. The aqueous tantalum acid solution (including resin) was again applied to the entire surface of the dried carbon substrate using a brush, and then the process of drying for 10 minutes in an electric furnace heated to 110°C was repeated two more times. That is, the process of applying and drying the aqueous tantalum acid solution (including resin) to the carbon substrate was repeated three times in total (the total coating amount for all three times was 0.0225 g). Thereafter, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. Then, by cooling to room temperature, a film structure according to Example 4 was obtained.

[0118] In addition, since the aqueous tantalum acid solution (including resin) used in Example 4 is the same as the aqueous tantalum acid solution (including resin) used in Example 3, detailed description thereof is omitted.

[0119] On the other hand, since the carbon substrate used in Example 4 is the same as the carbon substrate used in Example 1, detailed description thereof is omitted.

[0120] (Example 5) An aqueous tantalum acid compound solution was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) using a brush (the coating amount was 0.0075 g). Next, the carbon substrate coated with the aqueous tantalum acid compound solution was placed in an electric furnace, and dried for 10 minutes in an electric furnace heated to 110°C. Thereafter, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. Then, by cooling to room temperature, a film structure according to Example 5 was obtained.

[0121] The aqueous tantalum acid compound solution used in Example 5 was obtained as follows.

[0122] 100 g of tantalum hydroxide manufactured by Mitsui Mining Co., Ltd. (Ta2O5 concentration: 99.9 mass%) was dissolved in 100 g of a 55 mass% hydrofluoric acid aqueous solution, and 100 mL of ion-exchanged water was added to obtain an aqueous tantalum fluoride solution (Ta2O5 concentration: 33.3 mass%).

[0123] 1000 mL of aqueous ammonia (NH3 concentration: 25 mass%) was added to 100 g of this aqueous tantalum fluoride solution to obtain a fluorine-containing tantalum hydrate cake.

[0124] Next, this fluorine-containing tantalum hydrate cake was decanted using a centrifuge with dilute aqueous ammonia and washed until the amount of free fluoride ions became 100 mg / L or less to obtain a tantalum-containing precipitate from which the fluoride ions had been removed. At this time, aqueous ammonia was used as the washing liquid.

[0125] Here, for the tantalum concentration of the obtained tantalum-containing precipitate, a part of the tantalum-containing precipitate was collected, dried at 110°C for 24 hours, and then calcined at 1000°C for 4 hours to produce Ta2O5. The weight of the thus-produced Ta2O5 was measured, and the Ta2O5 (tantalum oxide, oxide conversion) concentration of the tantalum-containing precipitate calculated from that weight was 50 mass%. Also, when the Ta (tantalum, metal conversion) concentration of the tantalum-containing precipitate was calculated, it was 40.9 mass%.

[0126] Then, 50 g of triethylamine at 10% by mass and 317 g of pure water were added to the obtained tantalum-containing precipitate, and the mixture was stirred for 10 minutes to obtain a tantalum-containing mixed solution. Thereafter, 83 g of 35% by mass hydrogen peroxide was added to the tantalum-containing mixed solution so that the final tantalum concentration was 5% by mass in terms of oxide (Ta2O5 equivalent) and 4.1% by mass in terms of metal (Ta equivalent), and the final hydrogen peroxide concentration was 6.8% by mass, and the mixture was stirred for 30 minutes to obtain the tantalum acid compound-containing solution used in Example 5. Here, the tantalum concentration of the tantalum acid compound-containing solution used in Example 5 was 5% in terms of Ta2O5 and 4.1% in terms of Ta. No precipitate or sediment was observed in the tantalum acid compound-containing solution used in Example 5. The pH of the tantalum acid compound-containing solution used in Example 5 was 11.0.

[0127] On the other hand, since the carbon substrate used in Example 5 was the same as the carbon substrate used in Example 1, detailed description thereof is omitted.

[0128] (Example 6) The tantalum acid compound-containing solution (including resin) was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) using a brush (the application amount was 0.0075 g). Next, the carbon substrate coated with the tantalum acid compound-containing solution (including resin) was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Thereafter, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. Then, by cooling to room temperature, a film structure according to Example 6 was obtained.

[0129] The tantalum acid compound-containing liquid (including resin) used in Example 6 was obtained by adding a polyolefin-based polymer copolymer neutralized salt (Zexen A manufactured by Sumitomo Seika Chemicals Co., Ltd.) to the tantalum acid compound-containing liquid used in Example 5 and stirring at 25°C for 30 minutes. Here, the tantalum concentration of the tantalum acid compound-containing liquid (including resin) used in Example 6 was 5% in terms of Ta2O5 and 4.1% in terms of Ta. The content of the resin component contained in the tantalum acid compound-containing liquid (including resin) used in Example 6 was 0.025% by mass when the tantalum acid compound-containing liquid (including resin) was taken as 100% by mass.

[0130] Since the polyolefin-based polymer copolymer neutralized salt added in Example 6 is the same as the polyolefin-based polymer copolymer neutralized salt used in Example 3, detailed description thereof is omitted.

[0131] On the other hand, since the carbon substrate used in Example 6 is the same as the carbon substrate used in Example 1, detailed description thereof is omitted.

[0132] (Example 7) In Example 7, a production method similar to that of Example 1 was carried out except that the carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 25 mm × 25 mm × 3 mm) and the tantalum concentration of the tantalum peroxocitrate solution used in Example 7 were adjusted to 1% in terms of Ta2O5 and 0.8% in terms of Ta, and a film structure according to Example 7 was obtained. The coating amount of the tantalum peroxocitrate solution used in Example 7 was 0.054 g.

[0133] (Example 8) In Example 8, a production method similar to that of Example 1 was carried out except that the carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 25 mm × 25 mm × 3 mm) and the tantalum concentration of the tantalum peroxocitrate solution used in Example 8 were adjusted to 5% in terms of Ta2O5 and 4.1% in terms of Ta, and a film structure according to Example 8 was obtained. The coating amount of the tantalum peroxocitrate solution used in Example 8 was 0.113 g.

[0134] (Example 9) In Example 9, a carbon substrate (vertical dimension × horizontal dimension × thickness dimension: 25 mm × 25 mm × 3 mm) was used, and the tantalum concentration of the tantalum peroxocitrate solution used in Example 9 was adjusted to 16.4% in terms of Ta (20% in terms of Ta2O5). Otherwise, the same manufacturing method as in Example 1 was carried out to obtain a coating structure according to Example 9. The coating amount of the tantalum peroxocitrate solution used in Example 9 was 0.174 g.

[0135] (Example 10) In Example 10, a carbon substrate (vertical dimension × horizontal dimension × thickness dimension: 25 mm × 25 mm × 3 mm) was used, the carbon substrate was a CIP material (graphite flat plate CIP material manufactured by Tokyo Carbon Industry Co., Ltd.), and the tantalum concentration of the tantalum peroxocitrate solution used in Example 10 was adjusted to 16.4% in terms of Ta (20% in terms of Ta2O5). Otherwise, the same manufacturing method as in Example 1 was carried out to obtain a coating structure according to Example 10. The coating amount of the tantalum peroxocitrate solution used in Example 10 was 0.2 g.

[0136] (Example 11) An aqueous tantalum acid solution (including resin) was applied to the entire surface of a carbon substrate (vertical dimension × horizontal dimension × thickness dimension: 25 mm × 25 mm × 10 mm) using a brush (the coating amount was 3.04 g). Next, the carbon substrate coated with the aqueous tantalum acid solution (including resin) was placed in an electric furnace and dried in an electric furnace heated to 110 °C for 10 minutes. Then, it was heated in an electric furnace heated to 1500 °C for 1 hour under an Ar atmosphere. And by cooling to room temperature, a coating structure according to Example 11 was obtained.

[0137] The aqueous tantalum acid solution (including resin) used in Example 11 was obtained by carrying out the same manufacturing method as in Example 3, except that the tantalum concentration of the aqueous tantalum acid solution (including resin) used in Example 11 was adjusted to 0.8% in terms of Ta (1% in terms of Ta2O5).

[0138] Since the polyolefin polymer copolymer neutralized salt added in Example 11 is the same as the polyolefin polymer copolymer neutralized salt used in Example 3, a detailed description thereof will be omitted.

[0139] On the other hand, the carbon base material used in Example 11 was a heat insulating material (Kureha Corporation, Kureca felt GF-210).

[0140] (Example 12) A peroxotantalum citrate solution (containing a surfactant) was applied to the entire surface of a carbon base material (longitudinal dimension × transverse dimension × thickness dimension: 25 mm × 25 mm × 10 mm) using a brush (the coating amount was 1.99 g). Next, the carbon base material coated with the peroxotantalum citrate solution (containing a surfactant) was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Then, it was heated for 1 hour in an electric furnace heated to 1500°C under an Ar atmosphere. And by cooling to room temperature, a film structure according to Example 12 was obtained.

[0141] The peroxotantalum citrate solution (containing a surfactant) used in Example 12 was obtained as follows.

[0142] 200 g of tantalum hydroxide and 92 g of 25% by mass aqueous ammonia were stirred and mixed for 10 minutes to obtain a first mixed solution. Then, 220 g of 35% by mass hydrogen peroxide solution was further added to the first mixed solution and stirred for 10 minutes to obtain a second mixed solution. And 79 g of citric acid was added to the second mixed solution and stirred for 10 minutes to obtain a peroxotantalum citrate solution.

[0143] Then, a surfactant was added to the obtained tantalum peroxo citrate solution, and the mixture was stirred at 25°C for 30 minutes to obtain the tantalum peroxo citrate solution (containing surfactant) used in Example 12. Here, the tantalum concentration of the tantalum peroxo citrate solution (containing surfactant) used in Example 12 was 1% in terms of Ta2O5 and 0.8% in terms of Ta. The content of the surfactant contained in the tantalum peroxo citrate solution (containing surfactant) used in Example 12 was 0.025% by mass when the tantalum peroxo citrate solution was taken as 100% by mass.

[0144] Here, the added surfactant is a polyoxyethylene-added acetylene glycol-based surfactant.

[0145] On the other hand, since the carbon substrate used in Example 12 is the same as the carbon substrate used in Example 11, detailed description thereof is omitted.

[0146] (Example 13) The tantalum peroxo citrate solution (containing surfactant) was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 25 mm × 25 mm × 10 mm) using a brush (the application amount was 2.22 g). Next, the carbon substrate coated with the tantalum peroxo citrate solution (containing surfactant) was placed in an electric furnace and dried in an electric furnace heated to 110°C for 10 minutes. Then, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. And by cooling to room temperature, a film structure according to Example 13 was obtained.

[0147] The tantalum peroxo citrate solution (containing surfactant) used in Example 13 was obtained by carrying out the same production method as in Example 12, except that the tantalum concentration of the tantalum peroxo citrate solution (containing surfactant) used in Example 13 was adjusted to 5% in terms of Ta2O5 and 4.1% in terms of Ta.

[0148] Also, since the surfactant used in Example 13 is the same as the surfactant used in Example 12, detailed description thereof is omitted.

[0149] On the other hand, since the carbon substrate used in Example 13 is the same as the carbon substrate used in Example 11, a detailed description thereof will be omitted.

[0150] (Example 14) A peroxotantalum citrate solution (containing a surfactant) was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension: 50 mm × 50 mm) using a brush (the application amount was 0.44 g). Next, the carbon substrate coated with the peroxotantalum citrate solution (containing a surfactant) was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Then, it was heated for 1 hour in an electric furnace heated to 1500°C under an Ar atmosphere. And by cooling to room temperature, a film structure according to Example 14 was obtained.

[0151] The peroxotantalum citrate solution (containing a surfactant) used in Example 14 was obtained by carrying out the same production method as in Example 12, except that the tantalum concentration of the peroxotantalum citrate solution (containing a surfactant) used in Example 14 was adjusted to 5% in terms of Ta2O5 and 4.1% in terms of Ta.

[0152] Also, since the surfactant used in Example 14 is the same as the surfactant used in Example 12, a detailed description thereof will be omitted.

[0153] On the other hand, the carbon substrate used in Example 14 was a cloth (MUTEKI carbon cloth made by MUGE, carbon (carbon fiber)).

[0154] (Example 15) A peroxotantalum citrate solution was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension: 50 mm × 50 mm) using a brush (the application amount was 0.34 g). Next, the carbon substrate coated with the peroxotantalum citrate solution was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Then, it was heated for 1 hour in an electric furnace heated to 1500°C under an Ar atmosphere. And by cooling to room temperature, a film structure according to Example 15 was obtained.

[0155] The tantalum peroxocitrate solution used in Example 15 is the same as the tantalum peroxocitrate solution used in Example 8, so detailed description thereof is omitted.

[0156] On the other hand, the carbon substrate used in Example 15 is the same as the carbon substrate used in Example 14, so detailed description thereof is omitted.

[0157] (Example 16) The tantalum peroxocitrate solution was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension: 50 mm × 50 mm) using a brush (the coating amount was 0.75 g). Next, the carbon substrate coated with the tantalum peroxocitrate solution was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Thereafter, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. Then, by cooling to room temperature, a film structure according to Example 16 was obtained.

[0158] The tantalum peroxocitrate solution used in Example 16 is the same as the tantalum peroxocitrate solution used in Example 9, so detailed description thereof is omitted.

[0159] On the other hand, the carbon substrate used in Example 16 is the same as the carbon substrate used in Example 14, so detailed description thereof is omitted.

[0160] (Example 17) The metal oxide compound mixture was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension: 50 mm × 50 mm) using a brush (the coating amount was 0.5 g). Next, the carbon substrate coated with the metal oxide compound mixture was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Thereafter, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. Then, by cooling to room temperature, a film structure according to Example 17 was obtained.

[0161] When the metal acid compound mixture used in Example 17 is taken as 100%, it is a mixture adjusted so that an aqueous solution of tantalum acid, an aqueous solution of niobic acid, an aqueous solution of titanic acid, and an aqueous solution of zirconium are each 1%, and an aqueous solution of hafnium acid and an aqueous solution of silicic acid are each 0.2%. The metal acid compound mixture used in Example 17 was obtained as follows.

[0162] The aqueous solution of tantalum acid contained in the metal acid compound mixture used in Example 17 was obtained in the same manner as the aqueous solution of tantalum acid used in Example 3.

[0163] The aqueous solution of niobic acid used in Example 17 was obtained as follows.

[0164] 100 g of niobium pentoxide was dissolved in 200 g of a 55 mass% aqueous hydrofluoric acid solution, and 830 mL of ion-exchanged water was added to obtain an aqueous niobium fluoride solution (Nb2O5 = 8.84 mass%).

[0165] 200 mL of this aqueous niobium fluoride solution was added to 1 L of aqueous ammonia (NH3 concentration 25 mass%) in less than 1 minute (NH3 / Nb2O5 molar ratio = 177.9, NH3 / HF molar ratio = 12.2) to obtain a reaction solution (pH 11). This reaction solution was a slurry of a niobic acid compound hydrate, in other words, a slurry of a niobium-containing precipitate.

[0166] Next, this reaction solution was decanted using a centrifuge and washed until the amount of free fluoride ions became 100 mg / L or less to obtain a niobium-containing precipitate from which the fluoride ions were removed. At this time, aqueous ammonia was used as the washing solution.

[0167] Furthermore, the niobium-containing precipitate from which the fluoride ions were removed was diluted with pure water to obtain a slurry. A part of this niobium-containing precipitate slurry was dried at 110 °C for 24 hours and then calcined at 1000 °C for 4 hours to produce Nb2O5, and the Nb2O5 concentration contained in the niobium-containing precipitate slurry was calculated from its weight.

[0168] Then, pure water was added to the niobium-containing precipitation slurry diluted with this pure water, and a 50% by mass aqueous dimethylamine solution as an organic nitrogen compound was added so that the dimethylamine concentration became 7.2% by mass, and it was prepared to have a Nb2O5 solid content concentration of 24.0% by mass. This slurry was stirred for 48 hours to obtain the niobic acid aqueous solution used in Example 17. The pH of the niobic acid aqueous solution used in Example 17 was 11.0.

[0169] The titanic acid aqueous solution used in Example 17 was obtained as follows.

[0170] 33.3 g of titanyl sulfate (manufactured by Teika Co., TiO2 concentration 33.3% by mass, sulfuric acid concentration 51.1% by mass) was added to 66.7 g of ion-exchanged water and allowed to stand at 90 °C or higher for 1 hour to dissolve, obtaining a titanyl sulfate aqueous solution (titanium concentration (in terms of TiO2) 11% by mass, sulfuric acid 17% by mass, pH 1 or less).

[0171] 100 g of this titanyl sulfate aqueous solution was added to 100 g of 50% by mass dimethylamine (amine amount of 6.4 moles with respect to 1 mole of sulfuric acid in the titanyl sulfate aqueous solution) over a time of less than 1 minute. Then, it was stirred for 15 minutes to obtain a neutralization reaction solution (pH 12). This neutralization reaction solution was a slurry of titanium-containing substances, in other words, a slurry of titanium-containing precipitate.

[0172] Next, this neutralization reaction solution was decanted using a centrifuge and washed until the sulfuric acid in the supernatant became 100 mg / L or less to obtain a titanium-containing precipitate from which sulfuric acid was removed. At this time, aqueous ammonia was used as the washing solution.

[0173] A part of this titanium-containing precipitate was calcined at 1,000 °C for 4 hours to produce TiO2, and the TiO2 concentration contained in the titanium-containing precipitate was calculated from its mass. The TiO2 concentration was 11.0% by mass.

[0174] Then, 45 g of this titanium-containing precipitate and 5 g of tetramethylammonium hydroxide pentahydrate (TMAH concentration: 50% by mass) (0.443 mol per 1 mol of Ti in the titanium-containing precipitate) were mixed and shaken for 24 hours using a paint shaker to obtain the aqueous titanic acid solution used in Example 12. Here, the titanium concentration of the aqueous titanic acid solution used in Example 17 was 8% in terms of TiO₂ and 4.8% in terms of Ti. The pH of the aqueous titanic acid solution used in Example 17 was 13.7.

[0175] The aqueous zirconic acid solution used in Example 17 was obtained as follows.

[0176] 3.01 g (0.01 mol) of zirconium sulfate monohydrate was dissolved in 2.50 g (0.014 mol) of 55% by mass sulfuric acid aqueous solution, and 25 g of ion-exchanged water and 2.5 g (0.026 mol) of 35% by mass hydrogen peroxide solution were added (H₂O₂ / ZrO₂ molar ratio = 2.6) to obtain an aqueous zirconium sulfate solution containing zirconium at 4.3% by mass in terms of ZrO₂.

[0177] Next, the entire amount of the aqueous zirconium sulfate solution was added to 100 g (1.47 mol) of aqueous ammonia (NH₃ concentration: 25% by mass) in less than 1 minute (NH₃ / ZrO₂ molar ratio = 147, NH₃ / SO₄ 2- molar ratio = 43) to obtain a reaction solution by a so-called reverse neutralization reaction. This reaction solution was a slurry of zirconium acid compound hydrate, in other words, a slurry of zirconium-containing precipitate.

[0178] This reaction solution was decanted using a centrifuge and washed until the conductivity became 500 μS / cm or less to obtain a sulfur content-removed zirconium-containing precipitate. At this time, aqueous ammonia was used as the washing solution.

[0179] Furthermore, by diluting the zirconium-containing precipitate with sulfur removed with pure water, a zirconium-containing precipitate slurry with sulfur removed was obtained. A part of the zirconium-containing precipitate slurry with sulfur removed was dried at 110 °C for 24 hours and then calcined at 1,000 °C for 4 hours to produce ZrO2, and the ZrO2 concentration contained in the zirconium-containing precipitate slurry with sulfur removed was calculated from its weight.

[0180] Then, the zirconium-containing precipitate slurry with sulfur removed diluted with pure water was mixed with 13.7 g (0.023 mol) of 15% tetramethylammonium hydroxide (TMAH) and 28.5 g of ion-exchanged water so that the zirconium concentration of the final mixture was 10% by mass in terms of ZrO2 and the tetramethylammonium hydroxide (TMAH) concentration was 7.2% by mass (TMAH / ZrO2 molar ratio = 2.2). While stirring this mixture, it was held for 1 hour while maintaining the liquid temperature at room temperature (25 °C) to obtain the zirconium acid aqueous solution used in Example 11. Here, the zirconium concentration of the zirconium acid aqueous solution used in Example 17 was 8% in terms of ZrO2 and 5.9% in terms of Zr. The pH of the zirconium acid aqueous solution used in Example 17 was 13.7.

[0181] The hafnium acid aqueous solution used in Example 17 was obtained as follows.

[0182] To 76.0 g of hafnium oxide (purity 98%, powder, manufactured by High Purity Chemical Research Institute), 105.1 g of 55% by mass hydrofluoric acid and 796.9 g of pure water were added, heated to 80 °C using a water bath, and dissolved by stirring for 24 hours to obtain a hydrofluoric acid solution of a hafnium compound. To 60 g of this hydrofluoric acid solution of the hafnium compound, an aqueous solution of hafnium complex (H2O2 / Hf molar ratio = 1.0) obtained by adding 2.2 g of 35% by mass hydrogen peroxide solution was stirred for 5 minutes and then gradually added to 377.2 g of 25% by mass aqueous ammonia (NH3 / Hf molar ratio = 250). Then, it was stirred for 5 minutes to obtain a neutralization reaction solution containing hafnium hydroxide as a precipitate.

[0183] Next, this neutralization reaction solution was decanted using a centrifuge to recover the precipitate (containing hafnium hydroxide). The recovered precipitate was mixed with 200 g of 25% by mass aqueous ammonia and slurried, and then decanted again to recover the precipitate. This decantation and the step of recovering the precipitate (containing hafnium hydroxide) were repeated three times.

[0184] Then, a mixed solution was obtained by adding 31.1 g of 25% by mass TMAH to the recovered precipitate (containing hafnium hydroxide). Pure water was added until the total weight of the mixed solution reached 77.7 g so that the final hafnium concentration was 6% by mass in terms of HfO2, and the mixed solution was stirred for 6 hours to obtain the hafnium acid aqueous solution used in Example 17. The pH of the hafnium acid aqueous solution used in Example 17 was 14.8.

[0185] The silicic acid aqueous solution used in Example 17 was obtained as follows.

[0186] To 11.0 g of tetraethoxysilane (TEOS, manufactured by Tokyo Chemical Industry Co., Ltd.), which is a raw material substance containing silicon, in a 100 mL beaker, 0.1 g of acetic acid (manufactured by Hayashi Pure Chemical Industries, Ltd.), which is an acidic aqueous solution, 15 g of industrial ethanol (Solmix AP-7 (a mixed alcohol solvent containing 85.5% by mass of ethanol, 9.6% by mass of 1-propanol, 4.9% by mass of 2-propanol, and 0.2% by mass or less of water), manufactured by Toyo Petrochemical Co., Ltd.), and 8 g of pure water were added, and the mixture was stirred at room temperature (25°C) for 20 hours while stirring with a stirrer chip to obtain 6 g of a dried silicon compound, which is a transparent precipitate.

[0187] Next, 2.6 g of 40% by mass methylamine (manufactured by Mitsubishi Gas Chemical Company, Inc.) and 8.9 g of pure water were added to 6 g of the obtained dried silicon compound, and the mixture was stirred at room temperature (25°C) for 10 hours while stirring with a stirrer chip to obtain the silicic acid aqueous solution used in Example 17.

[0188] The aqueous solutions of tantalum acid, niobium acid, titanium acid, zirconium aqueous solution, hafnium acid, and silicic acid obtained in this manner were adjusted so that when the metal acid compound mixture used in Example 17 was taken as 100%, the aqueous solutions of tantalum acid, niobium acid, titanium acid, and zirconium aqueous solution were each 1%, and the aqueous solutions of hafnium acid and silicic acid were each 0.2%, whereby the metal acid compound mixture used in Example 17 was obtained.

[0189] (Example 18) A carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) was immersed in an aqueous solution of zirconium acid (about 10 ml) in a 50 mL beaker, and under reduced pressure conditions, the carbon substrate was impregnated with the aqueous solution of zirconium acid (so-called vacuum impregnation) (the impregnation amount was 0.98 g). Next, the carbon substrate impregnated with the aqueous solution of zirconium acid was placed in an electric furnace and dried in an electric furnace heated to 100 °C for 60 minutes. Then, it was heated in an electric furnace heated to 1500 °C for 1 hour under an Ar atmosphere. And by cooling to room temperature, a film structure according to Example 18 was obtained.

[0190] Since the aqueous solution of zirconium acid used in Example 18 was the same as the aqueous solution of zirconium acid used in Example 17, detailed description thereof is omitted.

[0191] On the other hand, since the carbon substrate used in Example 18 was the same as the carbon substrate used in Example 1, detailed description thereof is omitted.

[0192] (Example 19) A carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) was immersed in an aqueous solution of titanium acid (about 10 ml) in a 50 mL beaker, and under reduced pressure conditions, the carbon substrate was impregnated with the aqueous solution of titanium acid (the impregnation amount was 0.96 g). Next, the carbon substrate impregnated with the aqueous solution of titanium acid was placed in an electric furnace and dried in an electric furnace heated to 100 °C for 60 minutes. Then, it was heated in an electric furnace heated to 1500 °C for 1 hour under an Ar atmosphere. And by cooling to room temperature, a film structure according to Example 19 was obtained.

[0193] Since the aqueous titanate solution used in Example 19 is the same as the aqueous titanate solution used in Example 17, a detailed description thereof will be omitted.

[0194] On the other hand, since the carbon substrate used in Example 19 is the same as the carbon substrate used in Example 1, a detailed description thereof will be omitted.

[0195] (Comparative Example 1) Comparative Example 1 is a carbon substrate obtained by repeatedly discharging and processing the surface of the carbon substrate used in Example 1 using a discharge electrode made of a tantalum electrode.

[0196] (Comparative Example 2) A polyolefin polymer copolymer neutralized salt (Zicen A manufactured by Sumitomo Seika Chemicals Co., Ltd.) was applied to the entire surface of a carbon substrate (longitudinal dimension × transverse dimension × thickness dimension: 50 mm × 50 mm × 3 mm) using a brush. Next, the carbon substrate coated with the polyolefin polymer copolymer neutralized salt was placed in an electric furnace and dried for 10 minutes in an electric furnace heated to 110°C. Then, it was heated in an electric furnace heated to 1500°C for 1 hour under an Ar atmosphere. And by cooling to room temperature, the film structure according to Comparative Example 2 was obtained.

[0197] Since the polyolefin polymer copolymer neutralized salt used in Comparative Example 2 is the same as the polyolefin polymer copolymer neutralized salt used in Example 3, a detailed description thereof will be omitted.

[0198] On the other hand, since the carbon substrate used in Comparative Example 2 is the same as the carbon substrate used in Example 1, a detailed description thereof will be omitted.

[0199] (Comparative Example 3) Since Comparative Example 3 is the same as the carbon substrate used in Example 7, a detailed description thereof will be omitted.

[0200] (Comparative Example 4) Since Comparative Example 4 is the same as the carbon substrate used in Example 10, a detailed description thereof will be omitted.

[0201] (Comparative Example 5) Since Comparative Example 5 uses the same carbon substrate as that used in Example 11, a detailed description thereof will be omitted.

[0202] (Comparative Example 6) Since Comparative Example 6 uses the same carbon substrate as that used in Example 14, a detailed description thereof will be omitted.

[0203] (Comparative Example 7) Since Comparative Example 7 uses the same carbon substrate as that used in Example 1, a detailed description thereof will be omitted.

[0204] Then, for the film structures according to Examples 1 to 19, the carbon substrates according to Comparative Examples 1, 3 to 7, and the film structure according to Comparative Example 2, the following physical property values were measured and an evaluation test was conducted. Hereinafter, the measurement method of the physical property values and the test method of the evaluation test are shown. The physical property values of the film structures according to Examples 1 to 10, the carbon substrates according to Comparative Examples 1, 3 to 4, and the film structure according to Comparative Example 2 are shown in FIG. 1. Further, the physical property values of the film structures according to Examples 11 to 17 and the carbon substrates according to Comparative Examples 5 and 6 are shown in FIG. 2. Furthermore, the physical property values of the film structures according to Examples 18 and 19 and the carbon substrate according to Comparative Example 7 are shown in FIG. 3.

[0205] 〈Elemental analysis〉 If necessary, the sample was appropriately diluted with dilute hydrochloric acid, and the mass fraction in terms of metal was measured in accordance with JIS K0116:2014 using ICP emission analysis (manufactured by Agilent Technologies: AG-5110).

[0206] 〈Dynamic light scattering method〉 The evaluation of the particle size distribution of the metal compound inclusions used in Examples 1 to 19 was carried out in accordance with JIS Z 8828:2019 "Particle Size Analysis - Dynamic Light Scattering Method" using a zeta potential, particle size, and molecular weight measurement system (manufactured by Otsuka Electronics Co., Ltd.: ELSZ-2000). Also, in order to remove dust and the like in the solution to be measured immediately before measurement, the inclusion was filtered through a filter with a pore size of 2 μm, and ultrasonic treatment was carried out at 28 kHz for 3 minutes using an ultrasonic cleaner (manufactured by AS ONE Corporation: VS-100III). The particle size (D50) refers to the median diameter (D50) that indicates the 50% integrated value of the cumulative distribution curve.

[0207] 〈Measurement of Light Transmittance〉 4 ml of the metal compound inclusions used in Examples 1 to 19 were placed in a quartz cell with an optical path length of 5.0 mm, and the light transmittance of the metal compound inclusions used in Examples 1 to 19 in the wavelength range of 500 nm to 700 nm was measured using a spectrophotometer according to the above-described light transmittance measurement conditions or light transmittance measurement conditions (including Si).

[0208] 〈Heat Resistance Test〉 The film structures according to Examples 1 to 19, the carbon substrates according to Comparative Examples 1, 3 to 7, and the film structure according to Comparative Example 2 were subjected to a heat resistance test by dividing them into the following three test conditions.

[0209] 〈Heat Resistance Test 1〉 First, for the coating structures according to Examples 1 to 17, the carbon substrates according to Comparative Examples 1, 3 to 6, and the coating structure according to Comparative Example 2, the weight before Heat Resistance Test 1 (hereinafter referred to as the weight before Test 1) was measured respectively. Next, the coating structures according to Examples 1 to 17, the carbon substrates according to Comparative Examples 1, 3 to 6, and the coating structure according to Comparative Example 2 were placed in a tubular furnace and fired at a heating temperature of 700°C for 90 minutes in an air atmosphere. The fired coating structures according to Examples 1 to 17, the carbon substrates according to Comparative Examples 1, 3 to 6, and the coating structure according to Comparative Example 2 were taken out of the tubular furnace, and the weight after Heat Resistance Test 1 (hereinafter referred to as the weight after Test 1) was measured respectively. Then, for the coating structures according to Examples 1 to 17, the carbon substrates according to Comparative Examples 1, 3 to 6, and the coating structure according to Comparative Example 2, the weight change (attenuation rate) of Heat Resistance Test 1 was calculated from the following formula (1) based on the weight before Test 1 and the weight after Test 1.

[0210] [Number]

[0211] In addition, the test results of Heat Resistance Test 1 for the coating structures according to Examples 1 to 10, the carbon substrates according to Comparative Examples 1, 3, 4, and the coating structure according to Comparative Example 2 are shown in Table 1. Also, the test results of Heat Resistance Test 1 for the coating structures according to Examples 11 to 17 and the carbon substrates according to Comparative Examples 6, 7 are shown in Table 2.

[0212] 〈Heat Resistance Test 2〉 For the coating structures according to Examples 5 and 6, the carbon base material according to Comparative Example 1, and the coating structure according to Comparative Example 2, the weights before the heat resistance test 2 (hereinafter referred to as the weight before Test 2) were measured respectively. Next, the coating structures according to Examples 5 and 6, the carbon base material according to Comparative Example 1, and the coating structure according to Comparative Example 2 were placed in a tubular furnace and fired at a heating temperature of 700 °C for 90 minutes in an atmosphere of a 5 vol% O2 - 95 vol% N2 mixed gas. The fired coating structures according to Examples 5 to 6, the carbon base material according to Comparative Example 1, and the coating structure according to Comparative Example 2 were taken out from the tubular furnace, and the weights after the heat resistance test 2 (hereinafter referred to as the weight after Test 2) were measured respectively. Then, for the coating structures according to Examples 5 and 6, the carbon base material according to Comparative Example 1, and the coating structure according to Comparative Example 2, the weight change (attenuation rate) of the heat resistance test 2 was calculated from the following formula (2) based on the weight before Test 2 and the weight after Test 2.

[0213]

Equation

[0214] The test results of the heat resistance test 2 for the coating structures according to Examples 5 and 6, the carbon base material according to Comparative Example 1, and the coating structure according to Comparative Example 2 are shown in Table 3.

[0215] 〈Heat Resistance Test 3〉 First, for the coating structures according to Examples 18 and 19 and the carbon base material according to Comparative Example 7, the weights before the heat resistance test 3 (hereinafter referred to as the weight before Test 3) were measured respectively. Next, the coating structures according to Examples 18 and 19 and the carbon base material according to Comparative Example 7 were placed in a tubular furnace and fired at a heating temperature of 600 °C for 180 minutes in an air atmosphere. The fired coating structures according to Examples 18 and 19 and the carbon base material according to Comparative Example 7 were taken out from the tubular furnace, and the weights after the heat resistance test 3 (hereinafter referred to as the weight after Test 3) were measured respectively. Then, for the coating structures according to Examples 18 and 19 and the carbon base material according to Comparative Example 7, the weight change (attenuation rate) of the heat resistance test 3 was calculated from the following formula (3) based on the weight before Test 3 and the weight after Test 3.

[0216]

Equation

[0217] The test results of the heat resistance test 3 of the film structures according to Examples 18 and 19 and the carbon base material according to Comparative Example 7 are shown in Table 4.

[0218]

Table 1

[0219]

Table 2

[0220]

Table 3

[0221]

Table 4

[0222] The film structures according to Examples 1 to 17 have a uniform metal-carbon composite film on the carbon base material by applying a metal compound-containing substance on the carbon base material and heating the carbon base material coated with the metal compound-containing substance.

[0223] The film structures according to Examples 18 and 19 have a uniform metal-carbon composite film on the carbon base material by immersing the carbon base material in a metal compound-containing substance and heating the immersed carbon base material.

[0224] Since the attenuation rate of the film structures according to Examples 1 to 6 in the heat resistance test 1 was 10% or less, no weight loss due to oxidation of the carbon base material was observed, and the heat resistance of the carbon base material could be improved by the metal-carbon composite film formed on the carbon base material. On the other hand, the attenuation rates of the carbon base material according to Comparative Example 1 and the film structure according to Comparative Example 2 in the heat resistance test 1 were 15.8% and 17.1%, respectively.

[0225] For the coating structures according to Examples 7 to 9, the attenuation rate in Heat Resistance Test 1 decreased slightly compared to the attenuation rate in Heat Resistance Test 1 of the carbon base material according to Comparative Example 3. Further, for the coating structure according to Example 10, the attenuation rate in Heat Resistance Test 1 decreased to half or less of the attenuation rate in Heat Resistance Test 1 of the carbon base material according to Comparative Example 4.

[0226] For the coating structures according to Examples 11 to 13, the attenuation rate in Heat Resistance Test 1 decreased compared to the attenuation rate in Heat Resistance Test 1 of the carbon base material according to Comparative Example 5. Further, for the coating structures according to Examples 14 to 17, the attenuation rate in Heat Resistance Test 1 decreased significantly compared to the attenuation rate in Heat Resistance Test 1 of the carbon base material according to Comparative Example 6.

[0227] Further, since the attenuation rate in Heat Resistance Test 2 of the coating structures according to Examples 5 to 6 was 2% or less, no weight loss due to oxidation of the carbon base material was observed, and the heat resistance of the carbon base material could be improved by the metal-carbon composite coating formed on the carbon base material. On the other hand, the attenuation rates in Heat Resistance Test 2 of the carbon base material according to Comparative Example 1 and the coating structure according to Comparative Example 2 were 2.7% and 2.7%, respectively.

[0228] For the coating structures according to Examples 18 and 19, the attenuation rate in Heat Resistance Test 3 decreased slightly compared to the attenuation rate in Heat Resistance Test 3 of the carbon base material according to Comparative Example 7.

[0229] From the results of the above-described Heat Resistance Tests 1 to 3, the heat resistance of the carbon base material could be improved by the metal-carbon composite coating formed on the carbon base material, regardless of the type of metal element contained in the metal-carbon composite coating, and the size and type of the carbon base material.

[0230] The invention disclosed in this specification includes, in addition to the configurations of each invention and embodiment, those in which, within an applicable range, these partial configurations are modified to other configurations disclosed in this specification and specified, or those in which other configurations disclosed in this specification are added to these configurations and specified, or those in which these partial configurations are deleted to the extent that partial operational effects can be obtained and upper-conceptualized.

Industrial Applicability

[0231] The manufacturing method of the coating structure according to the present invention can form a uniform metal-carbon composite coating on a carbon substrate regardless of the size and shape of the substrate, so it is suitable as a manufacturing method of the coating structure. Specifically, since the manufacturing method of the coating structure according to the present invention can form a uniform metal-carbon composite coating on a carbon substrate, it can improve heat resistance and reactivity, extend the life of the carbon substrate, reduce waste, and reduce the energy cost in waste disposal. Furthermore, the manufacturing method of the coating structure according to the present invention can form a uniform metal-carbon composite coating on a carbon substrate by applying a metal compound-containing substance on the carbon substrate, immersing the carbon substrate in the metal compound-containing substance, and heating it, so it is possible to reduce the energy cost. In addition, the coating structure according to the present invention is suitable as a coating structure because a uniform metal-carbon composite coating is formed on a carbon substrate regardless of the size and shape of the substrate. Specifically, since the coating structure according to the present invention has a uniform metal-carbon composite coating on a carbon substrate, it can improve heat resistance and reactivity, extend the life of the carbon substrate, reduce waste, and reduce the energy cost in waste disposal. These points lead to the sustainable management of natural resources and efficient advantages, as well as the achievement of decarbonization (carbon neutrality).

Claims

1. A method for producing a coated structure having a metal-carbon composite coating on a carbon substrate, comprising the steps of: A coating step of coating a metal compound-containing material on the carbon substrate; a heating step of heating the coated carbon substrate to form a metal-carbon composite coating on the carbon substrate; having The method for producing a coated structure, wherein the metal compound-containing material has a maximum light transmittance of 70%T or more in a wavelength range of 500 nm to 700 nm.

2. A method for producing a coated structure having a metal-carbon composite coating on a carbon substrate, comprising the steps of: A coating step of coating a metal compound-containing material on the carbon substrate; a heating step of heating the coated carbon substrate to form a metal-carbon composite coating on the carbon substrate; having A method for producing a coated structure, wherein the metal compound-containing material contains water and is in a liquid, sol, or gel state.

3. A method for producing a coated structure having a metal-carbon composite coating on a carbon substrate, comprising: A coating step of coating a metal compound-containing material on the carbon substrate; a heating step of heating the coated carbon substrate to form a metal-carbon composite coating on the carbon substrate; having The method for producing a coated structure, wherein the metal compound-containing material has a maximum light transmittance of 70%T or more in a wavelength region of 500 nm to 700 nm, contains water, and is in a liquid, sol, or gel state.

4. A method for manufacturing a coated structure as described in claim 2 or 3, characterized in that the content of a compound of at least one metal element selected from Ti, Nb, Mo, Hf, Ta, W, Zr, and Si in the metal compound inclusion is more than 0 mass% and not more than 35 mass%, in metal equivalent.

5. A method for producing a coated structure having a metal-carbon composite coating on a carbon substrate, comprising the steps of: A coating step of coating a metal compound-containing material on the carbon substrate; a heating step of heating the coated carbon substrate to form a metal-carbon composite coating on the carbon substrate; A method for producing a coated structure, comprising the steps of: However, the metal compound-containing substance excludes the compounds shown in (i) to (iii) below. (i) Organosilicon polymer compounds (ii) one or more refractory metal carbides selected from the group consisting of TaC, Ta 2 C, niobium carbide, tungsten carbide, and hafnium carbide, and one or more transition metal carbides selected from the group consisting of TiC, Cr 25 C 6 , Fe 3 C, Co 2 C, and Ni 2 C; (iii) Silicon carbide powder

6. A method for producing a coated structure having a metal-carbon composite coating on a carbon substrate, comprising the steps of: A coating step of coating a metal compound-containing material on the carbon substrate; a heating step of heating the coated carbon substrate to form a metal-carbon composite coating on the carbon substrate; having A method for producing a coated structure, characterized in that the metal compound-containing material contains a compound of at least one metal element selected from the group consisting of Ti, Nb, Mo, Hf, Ta, W, and Zr (excluding metal carbides).

7. 6. The method for producing a coated structure according to claim 1, wherein the metal compound-containing substance contains a compound of at least one metal element selected from the group consisting of Ti, Nb, Mo, Hf, Ta, W, Zr, and Si.

8. A method for producing a coated structure as described in any one of claims 1, 5 and 6, characterized in that the metal compound-containing material contains water.

9. Instead of the coating step, 7. The method for producing a coated structure according to claim 1, further comprising a step of immersing the carbon substrate in a material containing a metal compound.

10. 10. The method for producing a coated structure according to claim 9, wherein the immersion step comprises impregnating the carbon base material with the material containing a metal compound under reduced pressure or in vacuum.

11. 7. The method for producing a coated structure according to claim 1, further comprising a drying step between the coating step and the heating step.

12. A method for manufacturing a coated structure as described in claim 9, further comprising a drying step between the immersion step and the heating step.

13. 7. The method for producing a coated structure according to claim 1, wherein the metal compound-containing material has a pH of 6.5 or more and 13.5 or less.

14. 7. The method for producing a coated structure according to claim 1, wherein the heating step has a heating temperature of 1000° C. or more and 3500° C. or less and a heating time of 0.5 hours or more and 2 hours or less.

15. 15. The method for producing a coated structure according to claim 14, wherein the heating step is performed at a heating temperature of 1400° C. or more and 2000° C. or less.

16. A coated structure comprising a carbon substrate coated or impregnated with a metal compound-containing material containing a compound of at least one metal element selected from the group consisting of Ti, Nb, Mo, Hf, Ta, W, and Zr (excluding metal carbides).

17. A coated structure comprising a carbon substrate coated or impregnated with a metal compound-containing material excluding the compounds shown in (i) to (iii) below: (i) Organosilicon polymer compounds (ii) one or more refractory metal carbides selected from the group consisting of TaC, Ta 2 C, niobium carbide, tungsten carbide, and hafnium carbide, and one or more transition metal carbides selected from the group consisting of TiC, Cr 25 C 6 , Fe 3 C, Co 2 C, and Ni 2 C; (iii) Silicon carbide powder

18. A coated structure comprising a carbon substrate coated or impregnated with a metal compound-containing material having a maximum light transmittance of 70%T or more in the wavelength region of 500 nm to 700 nm.

19. 1. A metal compound containing material for a metal-carbon composite coating formed on a carbon substrate, comprising: A metal compound-containing material for a metal-carbon composite coating, comprising a compound (excluding metal carbides) of at least one metal element selected from the group consisting of Ti, Nb, Mo, Hf, Ta, W and Zr.

20. A metal compound-containing material for a metal-carbon composite coating formed on a carbon substrate, comprising: A metal compound-containing substance for a metal-carbon composite coating, characterized in that the following compounds (i) to (iii) are excluded: (i) Organosilicon polymer compounds (ii) one or more refractory metal carbides selected from the group consisting of TaC, Ta 2 C, niobium carbide, tungsten carbide, and hafnium carbide, and one or more transition metal carbides selected from the group consisting of TiC, Cr 25 C 6 , Fe 3 C, Co 2 C, and Ni 2 C; (iii) Silicon carbide powder 21. A metal compound-containing material for a metal-carbon composite coating formed on a carbon substrate, comprising: The metal compound-containing material for a metal-carbon composite coating is characterized in that the metal compound-containing material has a maximum light transmittance of 70%T or more in the wavelength region of 500 nm to 700 nm.

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