Coated substrate and method for producing coated substrate

Abstract

Provided is a novel coated substrate (1) which is applicable to various fields and from which high functionality can be expected. The coated substrate (1) is obtained by using a film (3) to coat a substrate (5). The thickness of the film (3) is 60 nm to 10 μm, and when the film (3) is measured, the element percentage of C (carbon) is 0.1 atm% or more and less than 10 atm%, the total element percentage of metallic elements and O (oxygen) is 80 atm% or more, the film (3) has a relative density of 90% or more, and the film (3) contains γ - Al2O3.

Description

Coated substrate and method for producing coated substrate

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to coated substrates and methods for making coated substrates.

[0002] Patent Documents 1 to 4 disclose coated substrates having metal oxide films. In Patent Documents 1 to 4, a wet film-forming method is employed. On the other hand, a dry film-forming method (dry process) is sometimes employed to control the thickness according to the complex shape of the substrate. Considering the performance when applied to various fields, conventional coated substrates are not necessarily sufficient, and the development of a new coated substrate has been desired.

[0003] JP 2011-32521 A JP 2009-147192 A JP 2015-93821 A JP 9-202606 A

[0004] The present disclosure has been made in view of the above-mentioned circumstances, and aims to provide a novel coated substrate that can be applied to various fields and is expected to have high performance. The present disclosure can be realized in the following aspects.

[0005] [1] A coated substrate in which a substrate is coated with a coating, wherein the thickness of the coating is 60 nm or more and 10 μm or less, and when the coating is measured, the element percentage of C (carbon) is 0.1 atomic % or more and less than 10 atomic %, and the total element percentage of metal elements and O (oxygen) is 80 atomic % or more, and the relative density of the coating is 90% or more, and the coating contains γ-Al. ２ O ３[2] The coated substrate according to [1], wherein the coating has a laminated structure in cross section. [3] The coated substrate according to [1] or [2], wherein the portion of the substrate on which the coating is formed is electrically conductive. [4] The coated substrate according to [2], wherein the thickness of each layer in the laminated structure is 30 nm or more and 500 nm or less. [5] The coated substrate according to [1] or [2], wherein no oxide film resulting from oxidation of the substrate is present between the coating and the substrate, or wherein the thickness of the oxide film resulting from oxidation of the substrate is less than 100 nm between the coating and the substrate. [6] A method for producing a coated substrate using a bath liquid containing an organic solvent as a solvent, wherein the bath liquid has a water content of less than 5 mass % and contains at least one or more metal elements and at least one or more halogen elements, and wherein a voltage is applied while the substrate is immersed in the bath liquid to form a coating containing the metal elements on the negative electrode side of the substrate, and then γ-Al is formed by heat treatment in a non-oxidizing atmosphere. ２ O ３ A method for producing a coated substrate, comprising forming

[0006] The present disclosure provides a novel coated substrate that can be mass-produced and is applicable to various fields. Furthermore, the coated substrate of the present disclosure exhibits high conformability of the coating to deformation of the substrate. Furthermore, the coated substrate of the present disclosure exhibits high adhesion between the coating and the substrate.

[0007] 1 is a schematic diagram of a cross section of a coated substrate, a schematic diagram of a film forming apparatus, and a diagram showing the XRD measurement results (X-ray diffraction peaks) of Experimental Example 1.

[0008] The present disclosure will be described in detail below. In this specification, when a numerical range is indicated using "-", it is assumed that the range includes both the lower limit and the upper limit unless otherwise specified. For example, the expression "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less". In addition, in this specification, the upper limit and lower limit of each numerical range can be combined in any way.

[0009] 1. Coated Substrate 1 The coated substrate 1 is formed by coating a substrate 5 with a coating 3. The thickness of the coating 3 is 60 nm or more and 10 μm or less. When the coating 3 is measured, the element percentage of C (carbon) is 0.1 atm % or more and less than 10 atm %, and the total element percentage of metal elements and O (oxygen) is 80 atm % or more. The coating 3 has a relative density of 90% or more. The coating 3 contains γ-Al ２ O ３ Includes:

[0010] (1) Substrate 5 The substrate 5 is not particularly limited. In order to increase the adhesion of the coating 3 to the substrate 5, it is preferable that at least the portion (region) of the substrate 5 that is covered by the coating 3 is made of a material that is conductive and can serve as the negative electrode 7 (cathode). Since the portion of the substrate 5 that is covered by the coating 3 is conductive and serves as the negative electrode 7 (cathode), the coating 3 can be easily formed on this portion by applying a voltage. The surface portion of the substrate 5 may be made of a material that is conductive and can serve as the negative electrode 7. The entire substrate 5 may be made of a material that can serve as the negative electrode 7. Suitable materials that can serve as the negative electrode 7 include, for example, iron-based alloys and carbon. Suitable examples of the iron-based alloy include one or more selected from Fe—Ni—Cr-based alloys (austenitic stainless steel), Fe—Cr-based alloys (ferritic stainless steel), Fe—Ni-based alloys (permalloy), Fe—Si-based alloys (iron silicon), Fe—Si—Al-based alloys (sendust), Fe—Ni—Mo (supermalloy), Fe—Co-based alloys (permendur), Fe—Ni—Co-based alloys (kovar), and Fe—C—B-based alloys (amorphous).

[0011] (2) Coating 3 (2.1) Thickness The thickness of the coating 3 is 60 nm or more, preferably 200 nm or more, and more preferably 300 nm or more, from the viewpoint of exhibiting a function appropriate to the material of the coating 3. On the other hand, from the viewpoint of withstanding stress generated in the coating 3 and ensuring adhesion to the substrate 5, the thickness is 10 μm or less, preferably 1000 nm or less, and more preferably 800 nm or less. From these viewpoints, the thickness of the coating 3 is 60 nm or more and 10 μm or less, preferably 200 nm or more and 1000 nm or less, and more preferably 300 nm or more and 800 nm or less. Note that if the thickness of the coating 3 is not constant, the thickness requirement is satisfied as long as the thickness of at least a portion of the coating 3 is within the above-mentioned range. The thickness of the coating 3 can be determined by observation with an FIB-SEM (dual beam scanning electron microscope).

[0012] (2.2) Carbon (C) Elemental Percentage When the coating 3 is measured by X-ray photoelectron spectroscopy (XPS), the carbon (C) elemental percentage is 0.1 atm% or more, preferably 0.5 atm% or more, and more preferably 1 atm% or more, from the viewpoint of suppressing grain growth in the coating 3 and stabilizing the properties of the coating 3. On the other hand, from the viewpoint of ensuring that the coating 3 functions sufficiently as an inorganic coating, the carbon (C) elemental percentage is less than 10 atm%, preferably 8 atm% or less, and more preferably 5 atm% or less. From these viewpoints, the carbon (C) elemental percentage is 0.1 atm% or more and less than 10 atm%, preferably 0.5 atm% or more and 8 atm% or less, and more preferably 1 atm% or more and 5 atm% or less. Note that when the composition of the coating 3 is not constant, the requirement for the carbon (C) elemental percentage is satisfied as long as the composition of at least a portion of the coating 3 is within the above-mentioned range. Composition analysis by X-ray photoelectron spectroscopy can be performed using an X-ray photoelectron spectrometer. Measurement conditions include an X-ray source using aluminum metal K-alpha rays, a beam diameter of 100 μm, and an X-ray incident angle of 45° to the surface to be analyzed, and the cross section is scanned.

[0013] (2.3) Total Elemental Percentage of Metal Elements and O (Oxygen) When the coating 3 is measured by X-ray photoelectron spectroscopy (XPS), the total elemental percentage of metal elements and O (oxygen) is 80 atm% or more, preferably 85 atm% or more, and more preferably 90 atm% or more, from the viewpoint of ensuring that the coating 3 functions sufficiently as an inorganic coating. The upper limit of the total elemental percentage of metal elements and O (oxygen) is 100 atm% minus the elemental percentage (atm%) of C (carbon). When the composition of the coating 3 is not constant, the requirement for the total elemental percentage of metal elements and O (oxygen) is satisfied as long as the composition of at least a portion of the coating 3 is within the above-mentioned range.

[0014] (2.4) Relative Density of Coating 3 From the viewpoint of ensuring that the coating 3 fully exhibits its functions, the relative density of the coating 3 is 90% or more, preferably 95% or more, and more preferably 98% or more. The relative density of the coating 3 may be 100%. The relative density of the coating 3 is determined by the following method. A cross-sectional TEM image cut in the thickness direction of the coating 3 is obtained. The area of ​​pores is measured in a field of view of 300 nm vertically and 1000 nm horizontally. The relative density (%) is determined using the following formula (1). The average value of the relative densities in 10 fields of view is the relative density of the coating 3. Note that if the thickness of the coating 3 is less than 300 nm vertically, the measurement is performed in a field of view that matches the thickness of the coating 3. Relative density (%) = {(S1 - S2) / S1} × 100 (1) (In the formula, S1 is the area (nm ) of a field of view of 300 nm vertically × 1000 nm horizontally) ２ ), and S2 is the total area of ​​the pores within a field of view of 300 nm long x 1000 nm wide (nm ２ ) is)

[0015] (2.5) γ-Al ２ O ３ The coating 3 contains γ-Al ２ O ３ The coating 3 contains γ-Al. ２ O ３ (γ-Al ２ O ３ The inclusion of γ-Al phase provides the following effects: ２ O ３ is α-Al ２ O ３ It has lower strength than γ-Al but is more flexible.２ O ３ When the base material 5 is deformed due to mechanical or thermal expansion, the coating 3 can conform to the base material 5 more easily.

[0016] (2.6) Layered Structure The coating 3 preferably has a layered structure in cross section. The layered structure of the coating 3 can be confirmed by observing a cross section of the coating 3 cut in the thickness direction with an FIB-SEM (dual beam scanning electron microscope). The layered structure of the coating 3 can suppress internal cracks in the coating 3 and peeling between the coating 3 and the substrate 5.

[0017] (2.7) Thickness of Each Layer in the Laminated Structure There are no particular limitations on the thickness of each layer in the laminated structure. From the viewpoint of ensuring the strength of the coating 3, the thickness of each layer is preferably 30 nm or more and 500 nm or less, more preferably 60 nm or more and 200 nm or less, and even more preferably 80 nm or more and 150 nm or less. The thickness of each layer can be determined by observing a cross section of the coating 3 cut in the thickness direction with an FIB-SEM (dual beam scanning electron microscope).

[0018] (2.8) Oxide Coating It is preferable that no oxide coating resulting from oxidation of the substrate 5 exists between the coating 3 and the substrate 5, or that the thickness of any oxide coating resulting from oxidation of the substrate 5 between the coating 3 and the substrate 5 is less than 100 nm. When this requirement is satisfied, the adhesion of the coating 3 to the substrate 5 improves, and the coating 3 is more likely to conform to the substrate 5 when the substrate 5 is deformed due to mechanical or thermal expansion. The presence or absence and thickness of an oxide coating can be determined by observing a cross section of the coating 3 cut in the thickness direction with an FIB-SEM (dual beam scanning electron microscope).

[0019] (2.9) Halogen Element When the coating 3 is measured by X-ray photoelectron spectroscopy, the element percentage of the halogen element is preferably 0.1 atm% or more, more preferably 0.3 atm% or more, and even more preferably 0.5 atm% or more. The upper limit of the element percentage of the halogen element is 3 atm% or less. When a trace amount of halogen element is contained in the coating 3, the oxide film present on the surface of the substrate 5 is removed by the action of the halogen element, resulting in a structure in which the coating 3 and the substrate 5 are in direct contact with each other, and as a result, it is believed that the adhesion between the substrate 5 and the coating 3 is ensured. From the viewpoint of rapidly progressing the organic electrochemical reaction and allowing the coating 3 to function as a high-quality protective film for the substrate 5, the halogen element is preferably at least one selected from the group consisting of I (iodine), Cl (chlorine), and Br (bromine).

[0020] (2.10) Metal Element The metal element is not particularly limited. From the viewpoint of easily forming a coating 3 with improved strength by the manufacturing method described below, the metal element is preferably at least one selected from the group consisting of Al (aluminum), Ti (titanium), Zr (zirconium), Mo (molybdenum), W (tungsten), V (vanadium), Fe (iron), Cr (chromium), Co (cobalt), and Mn (manganese).

[0021] 2. Manufacturing Method of Coated Substrate 1 The manufacturing method of the coated substrate 1 of the present disclosure is not particularly limited. A preferred manufacturing method will be described below. A preferred manufacturing method is a manufacturing method of the coated substrate 1 using a bath liquid 2 containing an organic solvent as a solvent. The bath liquid 2 has a water content of less than 5 mass %, contains at least one metal element, and contains at least one halogen element. This manufacturing method includes a forming step of forming a coating 3 containing a metal element on the substrate 5 on the negative electrode 7 side (cathode side) by applying a voltage while the substrate 5 is immersed in the bath liquid. In addition, this manufacturing method includes a step of forming a γ-Al coating 3 containing a metal element on the substrate 5 on the negative electrode 7 side (cathode side) by heat treatment in a non-oxidizing atmosphere after the forming step. ２ O ３ In the manufacturing method of the present disclosure, electrodeposition on the negative electrode 7 side can suppress oxidation of the substrate 5 more effectively than electrodeposition on the positive electrode 6 side (anode side).

[0022] (1) Bath Liquid 2 Bath liquid 2 contains an organic solvent as a solvent. (1.1) Water Content To ensure the homogeneity of the coating 3 and to suppress oxidation of the substrate 5, the water content of bath liquid 2 is set to less than 5% by mass. The water content is preferably less than 3% by mass, and more preferably less than 0.1% by mass. The water content may be 0% by mass. The water content of bath liquid 2 can be determined by GC-MS analysis.

[0023] (1.2) Metal Elements The bath liquid 2 contains at least one metal element. The metal element is not particularly limited. From the viewpoint of enabling the coating 3 to function as a high-quality protective film for the substrate 5, the metal element is preferably at least one selected from the group consisting of Al (aluminum), Ti (titanium), Zr (zirconium), Mo (molybdenum), W (tungsten), V (vanadium), Fe (iron), Cr (chromium), Co (cobalt), and Mn (manganese). In the manufacturing method of the present disclosure, an oxide film, which is the coating 3, is formed depending on the metal elements in the bath liquid 2. The metal elements contained in the bath liquid 2 may be supplied to the bath liquid 2 by elution from the positive electrode 6 (anode). When the metal elements are eluted from the positive electrode 6 into the bath liquid 2, it becomes easier to control the film formation rate and continuous and stable film formation on multiple substrates 5 becomes possible. When metal elements are supplied to the bath liquid 2 by dissolution from the positive electrode 6, it is preferable that the positive electrode 6 be at least one type of electrode selected from an Al electrode, a Ti electrode, and a Mo electrode. The metal elements in the bath liquid 2 may be supplied from a metal alkoxide and / or an inorganic metal compound. When metal elements are supplied by dissolving a metal alkoxide and / or an inorganic metal compound, it is possible to deal with elements that are difficult to supply by dissolving from the positive electrode 6 (anode). In this case, it is possible to form a film in which the composition ratio is controlled by combining multiple metal elements. Examples of metal alkoxides include aluminum alkoxides, titanium alkoxides, and molybdenum alkoxides. Examples of aluminum alkoxides include aluminum trialkoxides. Examples of aluminum trialkoxides include aluminum tripropoxides (e.g., aluminum triisopropoxide, aluminum tri-n-propoxide), aluminum triethoxide, and aluminum tributoxides (e.g., aluminum tri-sec-butoxide, aluminum tri-n-butoxide). Examples of titanium alkoxides include titanium trialkoxide and titanium tetraalkoxide, and titanium tetraalkoxide is preferred.Examples of titanium tetraalkoxides include titanium tetrapropoxide (e.g., titanium tetraisopropoxide, titanium tetra-n-propoxide, etc.), titanium tetramethoxide, titanium tetraethoxide, titanium tetrabutoxide (e.g., titanium tetraisobutoxide, titanium tetra-n-butoxide, etc.), titanium tetrapentoxide, titanium tetrahexoxide, and titanium tetra(2-ethylhexoxide). Examples of inorganic metal compounds include aluminum chloride, aluminum bromide, aluminum iodide, and titanium iodide. When the metal elements in the bath liquid 2 are supplied from metal alkoxides and / or inorganic metal compounds, the concentration of the metal elements in the bath liquid 2 is not particularly limited. In this case, from the viewpoint of forming a good coating 3, the concentration of the metal elements in the bath liquid 2 is preferably 1 ppm or more and 100 ppm or less, more preferably 3 ppm or more and 10 ppm or less, and even more preferably 4 ppm or more and 6 ppm or less. Incidentally, "ppm" stands for "parts per million" and stands for "mg / L." When the bath liquid 2 contains multiple metal elements, the concentration of the metal elements refers to the total concentration of the multiple metal elements. The concentration of the metal elements in the bath liquid 2 can be measured by ICP-MS analysis.

[0024] (1.3) Halogen Element The bath liquid 2 contains at least one type of halogen element. By including a halogen element in the bath liquid 2, film formation is carried out at a practical rate and the film 3 is more likely to be homogeneous. The halogen element is not particularly limited. From the viewpoint of rapidly progressing the organic electrochemical reaction and allowing the film 3 to function as a high-quality protective film for the substrate 5, the halogen element is preferably at least one selected from the group consisting of Cl (chlorine), Br (bromine), and I (iodine). The concentration of the halogen element in the bath liquid 2 is not particularly limited. From the viewpoint of appropriately suppressing the reaction rate, being advantageous in controlling the homogeneity and thickness of the film 3, and suppressing peeling of the film 3, the concentration of the halogen element is preferably 1 ppm or more and 20,000 ppm or less, more preferably 5 ppm or more and 2,000 ppm or less, and even more preferably 10 ppm or more and 100 ppm or less. Note that "ppm" means "parts per million" and "mg / L." The concentration of the halogen element in the bath liquid 2 can be determined by the amount of halogen element added when the bath is made up, or by ICP-MS analysis of the bath liquid.

[0025] (1.4) Organic Solvent By using an organic solvent as the solvent for the bath liquid 2, gas generation during film formation and oxidation of the substrate 5 itself are suppressed. From the viewpoint of favorable formation of the film 3, the solvent preferably contains at least one selected from the group consisting of ketones and nitriles. It is presumed that the inclusion of a ketone or nitrile in the solvent causes a condensation reaction on the electrode surface (cathode surface), making electrodeposition possible. It is also presumed that the inclusion of a ketone in the solvent causes keto-enol tautomerism in the presence of a halogen, improving the reactivity of the bath liquid 2.

[0026] (1.4.1) Ketones The ketone is not particularly limited as long as it is an organic solvent having a carbonyl group (—C(═O)—) other than an ester bond. Examples of ketones include acetone, methyl ethyl ketone (MEK), 1-hexanone, 2-hexanone, 4-heptanone, 2-heptanone (methyl amyl ketone), 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, diisobutyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, phenylacetone, acetophenone, methyl naphthyl ketone, cyclohexanone (CHN), and methylcyclohexanone. Among these, acetone and methyl ethyl ketone are preferred as the ketone from the viewpoint of particularly favorable formation of the coating 3.

[0027] (1.4.2) Nitriles Nitriles are organic solvents containing a nitrile group (—CN) in their structure. Examples of nitriles include acetonitrile, propionitrile, valeronitrile, and butyronitrile. Among these, acetonitrile is preferred as the nitrile from the viewpoint of forming the coating 3 particularly well.

[0028] (2) Substrate 5 For the "substrate 5", the explanation in the section "(1) Substrate 5" in "1. Coated substrate 1" above applies as is.

[0029] (3) Formation Step of Forming Coating 3 (Voltage Application) In the present disclosure, a voltage is applied while the substrate 5 is immersed in the bath liquid to form the coating 3 on the negative electrode side substrate 5. Specifically, a positive electrode 6 and a negative electrode 7 (substrate 5) are immersed in the bath liquid 2, and a potential gradient is generated between the two electrodes. Any known conductive substrate can be used as the positive electrode 6. When the metal elements in the bath liquid 2 are supplied by elution from the positive electrode 6, the positive electrode 6 is preferably at least one electrode selected from an Al electrode, a Ti electrode, and a Mo electrode. The shape, thickness, size, etc. of the positive electrode 6 are not particularly limited. The positive electrode 6 may be, for example, foil-shaped, plate-shaped, foam-shaped, nonwoven fabric-shaped, mesh-shaped, felt-shaped, or expanded. The positive electrode 6 and the negative electrode 7 are preferably disposed opposite each other. The positive electrode 6 and the negative electrode 7 are connected to a DC power source, and a potential gradient can be generated between the positive electrode 6 and the negative electrode by the DC power source. To generate a potential gradient between the positive electrode 6 and the negative electrode 7, the positive electrode 6 and the negative electrode 7 are immersed in the bath liquid 2, and a voltage (e.g., a constant voltage) is applied to both electrodes from a power source connected to the positive electrode 6 and the negative electrode 7. From the viewpoint of forming a coating at a practical speed, the potential gradient generated between the two electrodes is preferably 10 V to 300 V, more preferably 20 V to 100 V, and even more preferably 60 V to 80 V. The application time for the voltage is not particularly limited. For example, the application time is preferably 10 seconds to 300 seconds, more preferably 30 seconds to 240 seconds, and even more preferably 60 seconds to 180 seconds. The voltage may not be a constant voltage, but may be varied in magnitude. The formation process may be performed once or multiple times. The coating 3 can be thickened by repeating the formation process multiple times. Repeating the formation process multiple times in this manner allows the formation of a layered structure (layered horizontal stripe structure) of the coating 3.

[0030] (4) Heat Treatment Step: By heat treatment in a non-oxidizing atmosphere, γ-Al is formed in the coating 3. ２ O ３ The non-oxidizing atmosphere may be a reducing atmosphere, an inert atmosphere, or a vacuum atmosphere. The oxygen concentration in the non-oxidizing atmosphere is preferably less than 100 ppm. The heat treatment temperature is not particularly limited. The heat treatment temperature is２ O ３ From the viewpoint of selectively producing γ-Al, the temperature is preferably 800°C or higher and 1300°C or lower, more preferably 900°C or higher and 1200°C or lower, and even more preferably 950°C or higher and 1050°C or lower. The heat treatment time is not particularly limited. ２ O ３ From the viewpoint of selectively producing the above, the reaction time is preferably from 0.25 hours to 3 hours, more preferably from 0.5 hours to 2 hours, and even more preferably from 0.75 hours to 1 hour.

[0031] (5) Relationship between Forming Step and Heat Treatment Step When the forming step of forming the coating 3 is performed multiple times, the heat treatment step may be performed after the final forming step. Furthermore, when the forming step of forming the coating 3 is performed multiple times, the heat treatment step may be performed between the forming steps. In this case, the heat treatment step may be performed between all of the forming steps. Furthermore, there may be a mixture of cases where the heat treatment step is performed and cases where it is not performed between the forming steps. Furthermore, when the forming step of forming the coating 3 is performed multiple times and the heat treatment step is performed between the forming steps, the heat treatment step may also be performed after the final forming step.

[0032] 3. Effects of the Present Embodiment According to the present embodiment, a novel coated substrate 1 is provided that can be applied to various fields and is expected to have high functionality. According to the present embodiment, a coating 3 having excellent adhesion to the substrate 5 can be formed. In addition, the coating 3 can be made thicker than conventional coatings. The coated substrate 1 of the present embodiment is made of dense γ-Al ２ O ３Since a protective film of the crystalline phase is formed, the coating 3 can conform well to the substrate 5 when the substrate 5 is deformed mechanically or thermally. The coated substrate 1 of this embodiment can be mass-produced using a simple process. The coated substrate 1 of this embodiment is cost-effective because it can be formed without using expensive raw materials or using only small amounts of expensive raw materials. The film formation mechanism in this embodiment is presumed to be as follows: It is presumed that a condensation reaction occurs at the cathode while incorporating metal elements in the solvent, followed by an oxide film formation process in which condensation and hydrolysis occur on the surface of the substrate 5 due to the heat of vaporization during drying. However, this film formation mechanism is merely presumed, and the present disclosure is not bound by this film formation mechanism.

[0033] The present disclosure will be explained in more detail with reference to examples. In the following explanation, the measurement conditions for XPS (X-ray photoelectron spectroscopy) are as follows: [Measurement conditions] X-ray beam diameter: 100 μmΦ Signal acceptance angle: 45.0° Pass energy: 140 eV Measurement was performed after Ar etching for 30 seconds (etching rate: SiO ２ (equivalent to 10 nm / min)

[0034] 1. Experimental Example (Solvent: Acetone, Cathode 6: Aluminum) (1) Preparation of Coated Substrate 1 The film-forming apparatus 11 shown in FIG. 2 was used. An aluminum wire was used as the cathode 6. A Kovar plate was used as the anode 7. The anode 7 is the substrate 5 on whose surface a coating 3 is formed. Acetone was used as the solvent for the bath liquid 2. 50 ppm of iodine as a halogen was dissolved in the bath liquid 2. The cathode 6 and anode 7 were immersed in the bath liquid 2, and a voltage of 80 V was applied between the cathode 6 and anode 7 for 1 minute. This formation process was repeated nine times. Thereafter, a heat treatment was performed at 1000°C for 45 minutes in a non-oxidizing atmosphere (a reducing atmosphere using hydrogen gas).

[0035] (2) Various Measurement Results When the cross section of the negative electrode 7 was observed using a field emission scanning electron microscope (FIB-SEM), a coating 3 having a laminated structure and a total thickness of 600 nm was formed on the surface of the substrate 5. Furthermore, the thickness of each layer was 50 nm or more and 100 nm or less. This observation also confirmed that no oxide film resulting from oxidation of the substrate 5 existed between the coating 3 and the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that the coating 3 was aluminum oxide. Furthermore, the carbon percentage in the coating 3 was 5.8 atm%, and the total aluminum and oxygen percentage was 93.9 atm%. Furthermore, the iodine percentage in the coating 3 was 0.1 atm%. Furthermore, when the coating 3 was analyzed by XRD (X-ray crystal structure analysis) before and after heat treatment, as shown in FIG. 3 , after heat treatment, the γ-Al (black circles) that were not present before heat treatment were removed. ２ O ３ From this result, it was found that the heat treatment caused the γ-Al in the coating 3. ２ O ３ It was found that a film thickness of 300 nm was formed. Furthermore, the relative density of the film 3 was determined by the following method, and was found to be 100%. The relative density of the film 3 was determined by the following method. A cross-sectional TEM image cut in the film thickness direction was obtained. The area of ​​pores was measured in a field of view of 300 nm vertically and 1000 nm horizontally. The relative density (%) was determined by the following formula (1). The average value of the relative densities in 10 fields of view is the relative density of the film 3. Note that when the thickness of the film 3 is less than 300 nm vertically, the measurement is performed in a field of view that matches the thickness of the film 3. Relative density (%) = {(S1 - S2) / S1} × 100 (1) (In the formula, S1 is the area (nm ) of a field of view of 300 nm vertically × 1000 nm horizontally) ２ ), and S2 is the total area of ​​the pores within a field of view of 300 nm long x 1000 nm wide (nm ２ ) is)

[0036] 2. Effects of the Example According to the example, a novel coated substrate 1 is provided that can be applied to various fields and is expected to have high functionality.

[0037] The present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the claims of the present invention.

[0038] (Note) This specification includes the following inventions: [1] A coated substrate in which a substrate is coated with a coating, wherein the thickness of the coating is 60 nm or more and 10 μm or less, when the coating is measured, the element percentage of C (carbon) is 0.1 atomic % or more and less than 10 atomic %, the total element percentage of metal elements and O (oxygen) is 80 atomic % or more, the relative density of the coating is 90% or more, and the coating contains γ-Al ２ O ３ [2] The coated substrate according to [1], wherein the coating has a laminated structure in cross section. [3] The coated substrate according to [1] or [2], wherein the portion of the substrate on which the coating is formed is electrically conductive. [4] The coated substrate according to [2] or [3], wherein the thickness of each layer in the laminated structure is 30 nm or more and 500 nm or less. [5] The coated substrate according to any one of [1] to [4], wherein there is no oxide film resulting from oxidation of the substrate between the coating and the substrate, or the thickness of the oxide film resulting from oxidation of the substrate between the coating and the substrate is less than 100 nm. [6] A method for producing a coated substrate using a bath liquid containing an organic solvent as a solvent, wherein the bath liquid has a water content of less than 5 mass % and contains at least one or more metal elements and at least one or more halogen elements, and wherein a voltage is applied while the substrate is immersed in the bath liquid to form a coating containing the metal elements on the negative electrode side of the substrate, and thereafter, γ-Al is formed by heat treatment in a non-oxidizing atmosphere. ２ O ３ A method for producing a coated substrate, comprising forming

[0039] DESCRIPTION OF SYMBOLS 1: substrate to be coated 2: bath liquid 3: coating 5: substrate 6: positive electrode 7: negative electrode 11: film forming device

Claims

1. A coated substrate in which a substrate is coated with a coating, the coating has a thickness of 60 nm or more and 10 μm or less, when the coating is measured, the element percentage of C (carbon) is 0.1 atm% or more and less than 10 atm%, the total element percentage of metal elements and O (oxygen) is 80 atm% or more, the coating has a relative density of 90% or more, and the coating contains γ-Al. ２ O ３ A coated substrate comprising:

2. The coated substrate according to claim 1, wherein the coating has a laminated structure in cross-sectional form.

3. The coated substrate according to claim 1 or 2, wherein the portion of the substrate on which the coating is formed is electrically conductive.

4. The coated substrate according to claim 2, wherein the thickness of each layer in the laminated structure is 30 nm or more and 500 nm or less.

5. The coated substrate according to claim 1 or 2, wherein there is no oxide film between the coating and the substrate resulting from oxidation of the substrate, or the thickness of the oxide film between the coating and the substrate resulting from oxidation of the substrate is less than 100 nm.

6. A method for manufacturing a coated substrate using a bath liquid containing an organic solvent, the bath liquid having a moisture content of less than 5 mass%, containing at least one metal element, and containing at least one halogen element, the substrate is immersed in the bath liquid, and a voltage is applied to form a coating containing the metal element on the negative electrode side of the substrate, and then, a γ-Al coating is formed by heat treatment in a non-oxidizing atmosphere. ２ O ３ The method of manufacturing a coated substrate comprising forming

Images