Coated base material and method for producing coated base material

Abstract

Provided is a new coated base material which is applicable to various fields and from which high functionality can be expected.　A coated base material (1) is obtained by coating a base material (5) with a coating (3). The thickness of the coating (3) is not less than 60 nm but not more than 10 μm. When the coating (3) is measured, the element percentage of C (carbon) is not less than 0.1 atm% but less than 20 atm%, and the total element percentage of metal elements and O (oxygen) is not less than 70 atm%. The coating (3) is amorphous. The relative density of the coating (3) is not less than 90%.

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 comprising a substrate coated with a coating, wherein the coating has a thickness of 60 nm or more and 10 μm or less, and when the coating is measured, the elemental percentage of C (carbon) is 0.1 atomic % or more and less than 20 atomic %, and the total elemental percentage of metal elements and O (oxygen) is 70 atomic % or more, the coating is amorphous, the relative density of the coating is 90% or more, and the coating has a layered structure as a cross-sectional form. [2] The coated substrate according to [1], wherein a portion of the substrate where the coating is formed is electrically conductive. [3] The coated substrate according to [1] or [2], wherein the thickness of each layer in the layered structure is 20 nm or more and 500 nm or less. [4] The coated substrate according to [1] or [2], wherein the metal element is 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), Mn (manganese), and Mg (magnesium). [5] The coated substrate according to [1] or [2], wherein the coating contains a compound having at least one structure of a C—H bond, a C═O bond, or a C—O bond. [6] The coated substrate according to [1] or [2], wherein the coating contains a halogen element in an amount of 0.1 atm % or more. [7] 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, the method comprising: a forming step of forming a coating layer containing the metal elements on the substrate on a negative electrode side by applying a voltage while the substrate is immersed in the bath liquid; and a drying step of drying the coating layer, wherein a set of the forming step and the drying step is repeated at least two times to form a coating having a laminated structure.[8] A coated substrate obtained by coating a substrate 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 20 atomic %, and the total element percentage of metal elements and O (oxygen) is 70 atomic % or more, the coating is amorphous, and the relative density of the coating is 90% or more.

[0006] The present disclosure provides a novel coated substrate that can be mass-produced and is applicable to a variety of fields. Furthermore, the coated substrate of the present disclosure has reduced internal cracking of the coating and high adhesion between the coating and the substrate.

[0007] 1 is a schematic diagram of a cross section of an example of a coated substrate according to a first embodiment; FIG. 2 is a schematic diagram of a film forming apparatus; FIG. 3 is a schematic diagram of a cross section of an example of a coated substrate according to a second embodiment;

[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 40 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 20 atm %, and the total element percentage of metal elements and O (oxygen) is 70 atm % or more. The coating 3 is amorphous. The relative density of the coating 3 is 90% or more. The coating 3 may have a laminated structure in its cross-sectional form. That is, there are two types: a first embodiment having a laminated structure (see FIG. 1 ) and a second embodiment not having a laminated structure (see FIG. 3 ).

[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 40 nm or more, preferably 100 nm or more, and more preferably 200 nm or more, from the viewpoint of exhibiting a function according 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 40 nm or more and 10 μm or less, preferably 100 nm or more and 1000 nm or less, and more preferably 200 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 FIB-SEM observation.

[0012] (2.2) Carbon (C) Elemental Percentage The carbon (C) elemental percentage measured by X-ray photoelectron spectroscopy (XPS) of the coating 3 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 20 atm%, preferably 15 atm% or less, and more preferably 10 atm% or less. From these viewpoints, the carbon (C) elemental percentage is 0.1 atm% or more and less than 20 atm%, preferably 0.5 atm% or more and 15 atm% or less, and more preferably 1 atm% or more and 10 atm% or less. Note that if the composition of the coating 3 is not constant, the requirement for the carbon (C) elemental percentage is satisfied as long as at least a portion of the composition 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) Amorphous The coating 3 is amorphous. The amorphous nature of the coating 3 can be confirmed using a TEM image. The amorphous nature of the coating 3 is expected to result in the absence of crystal grains and the smoothing of the outermost surface due to uniform film growth.

[0015] (2.5) Relative Density of Coating 3 From the viewpoint of fully exhibiting the functions of the coating 3, 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 by 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)

[0016] (2.6) Layered Structure The coating 3 may have a layered structure in cross section. In this embodiment, 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 cracks inside 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 improving the strength of the coating 3, the thickness of each layer is preferably 20 nm or more and 500 nm or less, more preferably 40 nm or more and 300 nm or less, and even more preferably 60 nm or more and 200 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) Metal Element The metal element is not particularly limited. From the viewpoint of easily forming the coating 3 as a high-quality protective film 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), Mn (manganese), and Mg (magnesium).

[0019] (2.9) Compounds Having At Least One of the Structures of a C—H Bond, a C═O Bond, and a C—O Bond The coating 3 preferably contains a compound having at least one of the structures of a C—H bond, a C═O bond, and a C—O bond. Compounds having at least one of the structures of a C—H, C═O, and C—O bond volatilize at a lower temperature than elemental carbon (carbon) and induce shrinkage of the coating 3, which is presumed to improve the density of the coating 3. Furthermore, it is presumed that the remaining compounds having at least one of the structures of a C—H bond, a C═O bond, and a C—O bond in the coating 3 maintain the flexibility of the coating 3 and improve the adhesion of the coating 3 to the substrate 5.

[0020] (2.10) 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, thereby ensuring adhesion between the substrate 5 and the coating 3. 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).

[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 % and contains at least one metal element and at least one halogen element. This manufacturing method includes a forming step in which a voltage is applied while the substrate 5 is immersed in the bath liquid to form a coating layer containing a metal element on the substrate 5 on the negative electrode 7 side (cathode side). This manufacturing method also includes a drying step in which the coating layer is dried. In this manufacturing method, a set of the forming step and the drying step is repeated at least twice to form the coating 3 having a laminated structure. Note that, 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) Coating Layer Formation Process (Voltage Application) In the present disclosure, a coating layer is formed on the negative electrode side substrate 5 by applying a voltage while the substrate 5 is immersed in the bath liquid. 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 arranged 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, a voltage (e.g., a constant voltage) is applied to the positive electrode 6 and the negative electrode 7 by a power source connected to the positive electrode 6 and the negative electrode 7 while the electrodes are immersed in the bath liquid 2. From the viewpoint of forming a film at a practical speed, the potential gradient generated between the electrodes is preferably 10 V to 1000 V inclusive, more preferably 20 V to 500 V inclusive, and even more preferably 60 V to 200 V inclusive, in the case of a constant voltage. The application time for the voltage is not particularly limited. For example, the application time is preferably 10 seconds to 300 seconds inclusive, more preferably 30 seconds to 240 seconds inclusive, and even more preferably 60 seconds to 180 seconds inclusive. The voltage may not be a constant voltage, but may be variable in magnitude.

[0030] (4) Drying step of drying the coating 3 The drying temperature is not particularly limited. From the viewpoint of promoting shrinkage of the single layer (each coating layer) and thereby suppressing shrinkage of the entire coating 3 after lamination and making the coating 3 more resistant to stress, the drying temperature is preferably 0°C or higher and 1000°C or lower, more preferably 10°C or higher and 500°C or lower, and even more preferably 80°C or higher and 300°C or lower. The drying time is not particularly limited. From the viewpoint of promoting the dehydration reaction, the drying time is, for example, preferably 1 minute or higher and 3 hours or lower, more preferably 5 minutes or higher and 2 hours or lower, and even more preferably 10 minutes or higher and 1 hour or lower.

[0031] (5) Repeating a Set of Forming Step and Drying Step In the first embodiment having a laminated structure, a set of the forming step and the drying step is repeated at least two times to form the laminated coating 3. In the second embodiment not having a laminated structure, the set of the forming step and the drying step may be repeated once.

[0032] 3. Effects of the Coated Substrate 1 of the Present Embodiment This embodiment provides a novel coated substrate 1 that can be applied to various fields and is expected to have high functionality. This embodiment can provide a coated substrate in which cracks inside the coating 3 are suppressed and high adhesion between the coating 3 and the substrate 5 is achieved. 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 a 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 described in more detail with reference to examples. In the following description, 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 Ar etching for 30 seconds (etching rate: SiO ２ (equivalent to 10 nm / min)

[0034] 1. Preparation of Coated Substrates Experimental Examples 1-1, 1-2, 3-1, 3-2, 5-1, and 5-2 are examples. Experimental Examples 2-1, 2-2, 4-1, 4-2, 6-1, and 6-2 are examples. (1) Experimental Example 1-1 The film-forming apparatus 11 shown in FIG. 2 was used. An aluminum wire was used as the positive electrode 6. A stainless steel plate was used as the negative electrode 7. The negative electrode 7 was the substrate 5 on whose surface the coating 3 was formed. Acetone was used as the solvent for the bath liquid 2. 600 ppm of iodine as a halogen was dissolved in the bath liquid 2. With the positive electrode 6 and the negative electrode 7 immersed in the bath liquid 2, two sets of a coating layer formation process in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 1 minute and a drying process in which the electrodes were dried at 100°C for 10 minutes were repeated. When the cross section of the negative electrode 7 was observed using a FIB-SEM (field emission scanning electron microscope), a coating 3 having a two-layer laminate structure with each coating layer (single layer) having a thickness of 100 nm and a total thickness of 200 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that this coating 3 was aluminum oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 5.8 atm%, and the total elemental percentage of aluminum element and oxygen element was 93.9 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, in a cross-sectional TEM electron diffraction analysis of a film cut in the thickness direction of the coating 3, no diffraction pattern was observed, confirming that the coating 3 was amorphous. Furthermore, when the relative density of the coating 3 was determined by the following method, the relative density was 100%. The relative density of the coating 3 was determined by the following method. A cross-sectional TEM image of the coating 3 cut in the film thickness direction was obtained. The area of ​​the pores was measured in a field of view 300 nm vertically and 1000 nm horizontally. The relative density (%) was calculated 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 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)

[0035] (2) Experimental Example 1-2 The film-forming apparatus 11 shown in FIG. 2 was used. A magnesium wire was used as the positive electrode 6. A stainless steel plate was used as the negative electrode 7. The negative electrode 7 was the substrate 5 on whose surface the coating 3 was formed. Acetone was used as the solvent for the bath liquid 2. 600 ppm of iodine as a halogen was dissolved in the bath liquid 2. The positive electrode 6 and the negative electrode 7 were immersed in the bath liquid 2. Two sets of a coating layer formation process in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 1 minute and a drying process in which the electrodes were dried at 100°C for 10 minutes were repeated. Observation of the cross section of the negative electrode 7 using a field emission scanning electron microscope (FIB-SEM) revealed that a coating 3 having a two-layer laminate structure with each coating layer (single layer) 100 nm thick and a total thickness of 200 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that the coating 3 was magnesium oxide. The elemental percentage of carbon in the coating 3 was 7.6 atm%, and the total elemental percentage of magnesium and oxygen was 91.6 atm%. The elemental percentage of iodine in this coating 3 was 0.1 atm%. Furthermore, no diffraction pattern was observed in a cross-sectional TEM electron diffraction analysis of the coating 3 cut in the thickness direction, confirming that the coating 3 was amorphous. The relative density of the coating 3 was determined by the above-mentioned method and was found to be 100%.

[0036] (3) Experimental Example 2-1 The film-forming apparatus 11 shown in FIG. 2 was used. An aluminum wire was used as the positive electrode 6. A stainless steel plate was used as the negative electrode 7. The negative electrode 7 was a substrate 5 on whose surface a coating 3 was formed. Acetone was used as the solvent for the bath liquid 2. 600 ppm of iodine as a halogen was dissolved in the bath liquid 2. With the positive electrode 6 and the negative electrode 7 immersed in the bath liquid 2, a coating layer formation process was performed in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 2 minutes, and a drying process was performed in which the electrodes were dried at 80°C for 10 minutes. Observation of the cross section of the negative electrode 7 using a field emission scanning electron microscope (FIB-SEM) revealed that a coating 3 having a single layer (single layer) structure with a thickness of 200 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that the coating 3 was aluminum oxide. The elemental percentage of carbon in the coating 3 was 6 atm %, and the total elemental percentage of aluminum and oxygen was 90 atm %. The elemental percentage of iodine in this coating 3 was 0.1 atm %. Furthermore, no diffraction pattern was observed in a cross-sectional TEM electron diffraction analysis of the coating 3 cut in the thickness direction, confirming that the coating 3 was amorphous. The relative density of the coating 3 was determined by the above-mentioned method and was found to be 100%.

[0037] (4) Experimental Example 2-2 The film-forming apparatus 11 shown in FIG. 2 was used. A magnesium wire was used as the positive electrode 6. A stainless steel plate was used as the negative electrode 7. The negative electrode 7 was the substrate 5 on whose surface the coating 3 was formed. Acetone was used as the solvent for the bath liquid 2. 600 ppm of iodine as a halogen was dissolved in the bath liquid 2. The positive electrode 6 and the negative electrode 7 were immersed in the bath liquid 2. A set of a coating layer formation process in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 2 minutes and a drying process in which the electrodes were dried at 80°C for 10 minutes was repeated. Observation of the cross section of the negative electrode 7 using a field emission scanning electron microscope (FIB-SEM) revealed that a coating 3 having a two-layer laminate structure with each coating layer (single layer) 100 nm thick and a total thickness of 200 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that the coating 3 was magnesium oxide. The elemental percentage of carbon in the coating 3 was 9.9 atm%, and the total elemental percentage of magnesium and oxygen was 89.7 atm%. The elemental percentage of iodine in this coating 3 was 0.1 atm%. Furthermore, no diffraction pattern was observed in a cross-sectional TEM electron diffraction analysis of the coating 3 cut in the thickness direction, confirming that the coating 3 was amorphous. The relative density of the coating 3 was determined by the above-mentioned method and was found to be 100%.

[0038] (5) Experimental Example 3-1 The same procedure as in Experimental Example 1 was performed, except that five sets of a coating layer formation step in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 1 minute and a drying step in which drying was performed at 80 °C for 10 minutes were repeated. 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 five-layer laminate structure with each coating layer (single layer) having a thickness of 100 nm and a total thickness of 500 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that this coating 3 was aluminum oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 6 atm%, and the total elemental percentage of aluminum element and oxygen element was 90 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, no diffraction pattern was observed in a cross-sectional TEM electron diffraction analysis of a film cut in the film thickness direction of the coating 3, confirming that the coating 3 was amorphous. Furthermore, when the relative density of the coating 3 was determined by the above-mentioned method, the relative density was 100%.

[0039] (6) Experimental Example 3-2 The same procedure as in Experimental Example 1-2 was carried out, except that five sets of a coating layer formation step in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 1 minute and a drying step in which drying was performed at 80 °C for 10 minutes were repeated. 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 five-layer laminate structure with each coating layer (single layer) having a thickness of 100 nm and a total thickness of 500 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that this coating 3 was magnesium oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 8.9 atm%, and the total elemental percentage of magnesium element and oxygen element was 90 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, no diffraction pattern was observed in a cross-sectional TEM electron diffraction analysis of a film cut in the film thickness direction of the coating 3, confirming that the coating 3 was amorphous. Furthermore, when the relative density of the coating 3 was determined by the above-mentioned method, the relative density was 100%.

[0040] (7) Experimental Example 4-1 The same procedure as in Experimental Example 2 was carried out, except that one set of a coating layer formation step in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 5 minutes and a drying step in which drying was carried out at 80 °C for 10 minutes was performed. When the cross section of the negative electrode 7 was observed using a FIB-SEM (field emission scanning electron microscope), a coating 3 having a single layer (single layer) structure with a thickness of 500 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that this coating 3 was aluminum oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 6 atm%, and the total elemental percentage of aluminum element and oxygen element was 90 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, in a cross-sectional TEM electron diffraction analysis of the coating 3 cut in the thickness direction, no diffraction pattern was observed, confirming that the coating 3 was amorphous. Furthermore, when the relative density of the coating 3 was determined by the above-mentioned method, the relative density was 100%.

[0041] (8) Experimental Example 4-2 The same procedure as in Experimental Example 2-2 was carried out, except that one set of a coating layer formation step in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 5 minutes and a drying step in which drying was carried out at 80 °C for 10 minutes was performed. When the cross section of the negative electrode 7 was observed using a FIB-SEM (field emission scanning electron microscope), a coating 3 having a single layer (single layer) structure with a thickness of 500 nm was formed on the surface of the substrate 5. When analyzed using XPS after 30 seconds of Ar etching, this coating 3 was found to be magnesium oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 8.9 atm%, and the total elemental percentage of magnesium element and oxygen element was 90 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, in a cross-sectional TEM image cut in the thickness direction of the coating 3, no crystal grains were observed, confirming that the coating 3 was amorphous. Furthermore, when the relative density of the coating 3 was determined by the above-mentioned method, the relative density was 100%.

[0042] (9) Experimental Example 5-1 The same procedure as in Experimental Example 1 was carried out, except that 20 sets of a coating layer formation step in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 1 minute and a drying step in which drying was performed at 80 °C for 10 minutes were repeated. 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 20-layer laminate structure with a total thickness of 2000 nm and each coating layer (single layer) having a thickness of 100 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that this coating 3 was aluminum oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 6 atm%, and the total elemental percentage of aluminum element and oxygen element was 90 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, no diffraction pattern was observed in a cross-sectional TEM electron diffraction analysis of a film cut in the film thickness direction of the coating 3, confirming that the coating 3 was amorphous. Furthermore, when the relative density of the coating 3 was determined by the above-mentioned method, the relative density was 100%.

[0043] (10) Experimental Example 5-2 The same procedure as in Experimental Example 1-2 was carried out, except that 20 sets of a coating layer formation step in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 1 minute and a drying step in which drying was performed at 80 °C for 10 minutes were repeated. 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 20-layer laminate structure with a total thickness of 2000 nm and each coating layer (single layer) having a thickness of 100 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that this coating 3 was magnesium oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 8.9 atm%, and the total elemental percentage of magnesium element and oxygen element was 90 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, no crystal grains were observed in a cross-sectional TEM image of coating 3 cut in the thickness direction, confirming that coating 3 was amorphous. Furthermore, when the relative density of coating 3 was determined by the above-mentioned method, the relative density was found to be 100%.

[0044] (11) Experimental Example 6-1 The same procedure as in Experimental Example 2 was carried out, except that one set of a coating layer formation step in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 20 minutes and a drying step in which drying was carried out at 80 °C for 10 minutes was performed. When the cross section of the negative electrode 7 was observed using a FIB-SEM (field emission scanning electron microscope), a coating 3 having a single layer (single layer) structure with a thickness of 2000 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that this coating 3 was aluminum oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 6 atm%, and the total elemental percentage of aluminum element and oxygen element was 90 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, in a cross-sectional TEM electron diffraction analysis of the coating 3 cut in the thickness direction, no diffraction pattern was observed, confirming that the coating 3 was amorphous. Furthermore, when the relative density of the coating 3 was determined by the above-mentioned method, the relative density was 100%.

[0045] (12) Experimental Example 6-2 The same procedure as in Experimental Example 2-2 was carried out, except that one set of a coating layer formation step in which 80 V was applied between the positive electrode 6 and the negative electrode 7 for 20 minutes and a drying step in which drying was carried out at 80 °C for 10 minutes was performed. When the cross section of the negative electrode 7 was observed using a FIB-SEM (field emission scanning electron microscope), a coating 3 having a single layer (single layer) structure with a thickness of 2000 nm was formed on the surface of the substrate 5. Analysis using XPS after 30 seconds of Ar etching revealed that this coating 3 was magnesium oxide. Furthermore, the elemental percentage of carbon element in the coating 3 was 8.9 atm%, and the total elemental percentage of magnesium element and oxygen element was 90 atm%. Furthermore, the elemental percentage of iodine element in this coating 3 was 0.1 atm%. Furthermore, in a cross-sectional TEM image cut in the thickness direction of the coating 3, no crystal grains were observed, confirming that the coating 3 was amorphous. Furthermore, when the relative density of the coating 3 was determined by the above-mentioned method, the relative density was 100%.

[0046] (13) XPS Analysis of Film 3 The films 3 formed in Experimental Examples 1-1, 1-2, 3-1, 3-2, 5-1, 5-2, 2-1, 2-2, 4-1, 4-2, 6-1, and 6-2 were analyzed by XPS. C═O bonds and C—O bonds were detected in all of the films 3.

[0047] 2. Evaluation (1) Evaluation Method The coated substrate of each experimental example was subjected to surface observation with an optical microscope and cross-sectional observation with an FIB-SEM. These observations were used to check for the presence or absence of cracks extending from the surface of the coating 3 to the substrate. Furthermore, the coated substrate of each experimental example was vacuum (reduced pressure) dried at room temperature, and then the surface was observed with an optical microscope and the cross-sectional observation with an FIB-SEM. These observations were used to check for the presence or absence of cracks extending from the surface of the coating 3 to the substrate. Furthermore, the coated substrate of each experimental example was heat-treated at 500°C in air, and then the surface was observed with an optical microscope and the cross-sectional observation with an FIB-SEM. These observations were used to check for the presence or absence of cracks extending from the surface of the coating 3 to the substrate.

[0048] (2) Evaluation Results The evaluation results are shown in Table 1. In Experimental Examples 1-1, 1-2, 3-1, 3-2, 5-1, and 5-2, no cracks occurred after film formation, drying under reduced pressure, or heat treatment. In Experimental Examples 2-1, 2-2, 4-1, and 4-2, no cracks occurred after film formation. In Experimental Examples 2-1, 2-2, 4-1, and 4-2, cracks were observed after drying under reduced pressure and heat treatment. In Experimental Examples 6-1 and 6-2, cracks were observed after film formation, drying under reduced pressure, and heat treatment.

[0049]

[0050] 3. 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.

[0051] 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.

[0052] (Additional Notes) This specification includes the following inventions. [1] A coated substrate comprising a substrate 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 elemental percentage of C (carbon) is 0.1 atomic % or more and less than 20 atomic %, and the total elemental percentage of metal elements and O (oxygen) is 70 atomic % or more, the coating is amorphous, the relative density of the coating is 90% or more, and the coating has a layered structure in cross section. [2] The coated substrate according to [1], wherein a portion of the substrate where the coating is formed is electrically conductive. [3] The coated substrate according to [1] or [2], wherein the thickness of each layer in the layered structure is 20 nm or more and 500 nm or less. [4] The coated substrate according to any one of [1] to [3], wherein the metal element is 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), Mn (manganese), and Mg (magnesium). [5] The coated substrate according to any one of [1] to [4], wherein the coating contains a compound having at least one structure selected from the group consisting of a C—H bond, a C═O bond, and a C—O bond. [6] The coated substrate according to any one of [1] to [5], wherein the coating contains a halogen element in an amount of 0.1 atm % or more. [7] 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, the method comprising: a forming step of forming a coating layer containing the metal elements on the substrate on a negative electrode side by applying a voltage while the substrate is immersed in the bath liquid; and a drying step of drying the coating layer, wherein a set of the forming step and the drying step is repeated at least two times to form a coating having a laminated structure.[8] A coated substrate obtained by coating a substrate 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 20 atomic %, and the total element percentage of metal elements and O (oxygen) is 70 atomic % or more, the coating is amorphous, and the relative density of the coating is 90% or more.

[0053] 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 comprising a substrate coated with a coating, the coating having a thickness of 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 20 atomic %, and the total element percentage of metal elements and O (oxygen) is 70 atomic % or more, the coating is amorphous, the coating has a relative density of 90% or more, and the coating has a layered structure as a cross-sectional form.

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

3. The coated substrate according to claim 1 or 2, wherein the thickness of each layer in the laminated structure is 20 nm or more and 500 nm or less.

4. The coated substrate according to claim 1 or 2, wherein the metal element is 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), Mn (manganese), and Mg (magnesium).

5. The coated substrate according to claim 1 or 2, wherein the coating contains a compound having at least one of the following structures: a C--H bond, a C=O bond, and a C--O bond.

6. The coated substrate according to claim 1 or 2, wherein the percentage of halogen elements in the coating is 0.1 atm % or more.

7. A method for producing a coated substrate using a bath liquid containing an organic solvent as a 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 method comprising: a forming step of forming a coating layer containing the metal element on the substrate on the negative electrode side by applying a voltage while the substrate is immersed in the bath liquid; and a drying step of drying the coating layer, wherein a set of the forming step and the drying step is repeated at least two times to form a coating having a laminated structure.

8. A coated substrate comprising a substrate coated with a coating, the coating having a thickness of 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 20 atomic %, the total element percentage of metal elements and O (oxygen) is 70 atomic % or more, the coating is amorphous, and the coating has a relative density of 90% or more.

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