Coated substrate and method for producing coated substrate

Abstract

To provide a new coated substrate.SOLUTION: The coated base material 1 is formed by coating a conductive base material 5 with a film 3. The thickness of the coating 3 is 50nm or more and less than 100 μm. The coating 3 contains at least one kind of ceramic particles 8. The ceramic particles 8 are bonded to each other by an amorphous metal oxide 10, and the main component of the film 3 is the metal oxide 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to coated substrates and methods for making coated substrates. [Background technology]

[0002] In metal members used in environments with temperature changes of 100° C. or more, a ceramic film is sometimes formed on the surface to improve the insulation properties (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-033245 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if there is a difference in the thermal expansion coefficient between the metal member and the ceramic film, there is a problem that distortion of the member or destruction of the film occurs. The present disclosure has been made in view of the above-mentioned circumstances, and has an object to provide a novel coated substrate. The present disclosure can be realized as the following aspects. [Means for solving the problem]

[0005] [1] A coated substrate in which a conductive substrate is coated with a coating, The thickness of the coating is 50 nm or more and less than 100 μm, the coating includes at least one type of ceramic particle; A coated substrate, wherein the ceramic particles are bonded together by an amorphous metal oxide, and the coating is mainly composed of the metal oxide. [2] The coated substrate according to [1], wherein the conductive substrate contains at least one element selected from the group consisting of Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Pt (platinum), and Pd (palladium) in a total amount of 30 mass% or more. [3] At least one location where the thickness of the coating is measured, The coated substrate according to [1] or [2], wherein the particle diameter of the ceramic particles present at the measurement point is equal to or less than half of the film thickness measured at the measurement point. [4] The coated substrate according to [1] or [2], wherein, when the coating is measured by fluorescent X-ray analysis, the following formula (1) is satisfied, where M1 is the mass ratio of the constituent elements of the ceramic particles and M2 is the mass ratio of the metal element among the constituent elements of the metal oxide, excluding oxygen and carbon. 0.01×M2≦M1≦0.20×M2…(1) [5] In the infrared absorption spectrum of the coating, the wave number is 650 cm -1 ~900cm -1 The maximum peak intensity at A is Wave number 3400cm -1 A substrate coated with [1] or [2], which satisfies the following formula (2) when the peak intensity at [1] is B. B / A<0.1 …(2) [6] When the coating was measured by X-ray photoelectron spectroscopy, the sum of the concentration of the constituent elements of the ceramic particles and the concentration of the constituent elements of the metal oxide is 70 atm% or more; The coated substrate according to [1] or [2], wherein the concentration of C (carbon) is 0.1 atm % or more and less than 20 atm %. [7] The coated substrate according to [1] or [2], wherein the metal oxide is present between the ceramic particles and the conductive substrate. [8] When observed from the surface of the coating, cracks are observed in the coating, The coated substrate according to [1] or [2], wherein the cracks do not reach the surface of the conductive substrate. [9] The coated substrate according to [1] or [2], wherein the ceramic particles are at least one selected from the group consisting of MgO, Al2O3, CaF2, AlN, BN, Si3N4, and ZrO2.

[10] The coated substrate according to [1] or [2], wherein the metal oxide comprises at least one selected from the group consisting of Mg (magnesium), Al (aluminum), Si (silicon), Ti (titanium), Zr (zirconium), Cr (chromium), Mn (manganese), Fe (iron), Co (cobalt), Ni (nickel), Mo (molybdenum), V (vanadium), and W (tungsten).

[11] The coated substrate according to [1] or [2], wherein, when the coating is measured by TEM-EDS, the coating contains any of the elements constituting the conductive substrate in a proportion of 0.1 mass % to 5 mass % relative to 100 mass % of the element with the largest component among the metal elements constituting the metal oxide.

[12] 3. The method for producing a coated substrate according to claim 1 or 2, wherein a bath solution containing an organic solvent and iodine as a solvent is used, the bath liquid has a water content of less than 5% by mass, contains at least one metal element, and contains the ceramic particles; The concentration of the ceramic particles in the bath liquid is greater than 0% by mass and less than 10% by mass, A voltage is applied to the conductive substrate while the conductive substrate is immersed in the bath solution to form a pre-heat treatment film containing a metal element on the negative electrode side of the conductive substrate, and then A method for producing a coated substrate, comprising a step of heat treating the substrate at a temperature of 400°C or higher for 1 minute or longer. [Effects of the Invention]

[0006] According to the present disclosure, by forming a film (composite film) of ceramic particles and metal oxide on a conductive substrate, the difference in thermal expansion coefficient between the conductive substrate and the film can be alleviated. Furthermore, the coating contains a metal oxide, which makes it possible to provide a coated substrate that is useful for applications in high temperature ranges or where a hard coating is required, compared to composite coatings using hydroxides. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram of a cross section of a coated substrate. [Figure 2] FIG. 2 is a schematic diagram of a cross section of a coating. [Figure 3] FIG. 1 is a schematic diagram of a film forming apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present disclosure will be described in detail below. In this specification, when a numerical range is indicated using "-", it is intended to include 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 conductive substrate 5 with a coating 3. The thickness of the coating 3 is 50 nm or more and less than 100 μm. The coating 3 contains at least one type of ceramic particles 8. The ceramic particles 8 are bonded together by amorphous metal oxide 10, and the main component of the coating 3 is metal oxide 10. By making the coating 3 a composite film of ceramic particles 8 and metal oxide 10, the difference in thermal expansion between the conductive substrate 5 and the coating 3 can be alleviated. Furthermore, because the coating 3 is a composite film of ceramic particles 8 and metal oxide 10, it is more suitable for use in high temperature ranges and for use in applications where a hard film is required than a composite film with a hydroxide.

[0010] (1) Conductive base material 5 There are no particular limitations on the conductive substrate 5. In order to improve the adhesion of the coating 3 to the conductive substrate 5, it is preferable that at least the portion (region) of the conductive substrate 5 that is covered with the coating 3 is made of a material that is conductive and can serve as a negative electrode 7 (cathode). When the portion of the conductive substrate 5 that is covered with the coating 3 has conductivity and serves as a negative electrode 7 (cathode), the coating 3 can be easily formed on this portion by applying a voltage. The surface portion of the conductive substrate 5 may be made of a material that has conductivity and can serve as the negative electrode 7. The entire conductive substrate 5 may be made of a material that can serve as the negative electrode 7. From the viewpoint of application to high-temperature applications, the conductive substrate 5 is preferably made of a metal material containing at least one element selected from the group consisting of Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Pt (platinum), and Pd (palladium) in a total amount of 30% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The conductive substrate 5 may also contain at least one element selected from the group consisting of Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Pt (platinum), and Pd (palladium) in a total amount of 100% by mass. For example, an iron-based alloy and carbon are suitable materials for the negative electrode 7. Suitable examples of the iron-based alloy include one or more selected from the group consisting of an Fe-Ni-Cr-based alloy (austenitic stainless steel), an Fe-Cr-based alloy (ferritic stainless steel), an Fe-Ni-based alloy (permalloy), an Fe-Si-based alloy (iron silicon), an Fe-Si-Al-based alloy (sendust), an Fe-Ni-Mo (supermalloy), an Fe-Co-based alloy (permendur), an Fe-Ni-Co-based alloy (kovar), and an Fe-CB-based alloy (amorphous).

[0011] (2) Coating 3 (2.1) Thickness The thickness of the coating 3 is 50 nm or more, preferably 80 nm or more, and more preferably 100 nm or more, from the viewpoint of exhibiting functions 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 conductive substrate 5, the thickness is 100 μm or less, preferably 10 μm or less, and more preferably 1 μm or less. From these viewpoints, the thickness of the coating 3 is 50 nm or more and 100 μm or less, preferably 80 nm or more and 10 μm or less, and more preferably 100 nm or more and 1 μm or less. Note that if the thickness of the coating 3 is not uniform, 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 a FIB-SEM (dual beam scanning electron microscope).

[0012] (3) Ceramic particles 8 There are no particular limitations on the ceramic particles 8. From the viewpoint of insulating properties and thermal conductivity, the ceramic particles 8 are preferably composed of at least one selected from the group consisting of inorganic oxides, inorganic fluorides, and inorganic nitrides. Suitable examples of inorganic oxides include at least one selected from the group consisting of MgO (magnesium oxide), Al2O3 (alumina (aluminum oxide), ZrO2 (zirconia), TiO2 (titania (titanium oxide)), MnO (manganese monoxide), and MnCo2O4 (manganese cobalt spinel). Suitable examples of inorganic fluorides include at least one selected from the group consisting of CaF2 (calcium fluoride), TbF3 (terbium trifluoride), DyF3 (dysprosium trifluoride), and AlF3 (aluminum trifluoride). Suitable examples of inorganic nitrides include at least one selected from the group consisting of AlN (aluminum nitride), BN (boron nitride), Si3N4 (silicon nitride), and TiN (titanium nitride). From the viewpoint of thermal conductivity and thermal expansion coefficient matching with the substrate, the ceramic particles are preferably at least one type selected from the group consisting of MgO, Al2O3, CaF2, AlN, BN, Si3N4, and ZrO2. The shape and particle size of the ceramic particles 8 are not particularly limited.

[0013] (4) Amorphous metal oxides 10 There are no particular limitations on the metal oxide 10. The metal oxide 10 is a general-purpose element, and from the viewpoint of facilitating the formation of an amorphous oxide, it is preferable that the metal oxide 10 contains at least one element selected from the group consisting of Mg (magnesium), Al (aluminum), Si (silicon), Ti (titanium), Zr (zirconium), Cr (chromium), Mn (manganese), Fe (iron), Co (cobalt), Ni (nickel), Mo (molybdenum), V (vanadium), and W (tungsten). The metal oxide 10 is amorphous. The fact that it is amorphous can be confirmed by the fact that no crystal grains are observed in a cross-sectional image observed by FIB-SEM, that no peaks derived from the coating 3 are observed in XRD analysis, or that the TEM electron diffraction pattern is unclear. If the metal oxide 10 is amorphous, it can be expected to exhibit unique functions such as smoothing of the outermost surface due to uniform film growth. The ceramic particles 8 are bonded to each other by the metal oxide 10 . The main constituent of the film 3 is a metal oxide 10. Here, the main constituent (main component) refers to a substance whose content (mass %) is 50 mass % or more.

[0014] (5) Particle size requirements for ceramic particles 8 In the coated substrate 1 of the present disclosure, it is preferable that, at at least one location where the thickness of the coating 3 is measured, the particle diameter of the ceramic particles 8 present at the measurement location is equal to or less than half the film thickness T measured at the measurement location. By satisfying this requirement, a layer of the metal oxide 10 with a sufficient thickness can be ensured. Furthermore, by satisfying this requirement, it is possible to prevent the ceramic particles 8 from falling off from the coating 3. There is no particular lower limit to the particle diameter D of the ceramic particles 8. It is preferable that the particle diameter D of the ceramic particles 8 is 1 / 100 or more of the film thickness T measured at the measurement point. The concept of this requirement will be explained with reference to Figure 2. The measurement point for the thickness of the coating 3 on the coated substrate 1 is indicated by an arrow. If the thickness of the coating 3 at this measurement point is T, then the particle diameter D of the ceramic particles 8 at this measurement point is 1 / 2T or less. If there are two or more ceramic particles 8 at the measurement point, it is sufficient that any one of them meets this requirement. The particle diameter D of the ceramic particle 8 means the maximum length of a straight line connecting the ends of the ceramic particle 8. The thickness T of the coating 3 and the particle diameter D of the ceramic particles 8 can be determined by observing the cross section of the coated substrate 1 with an FIB-SEM.

[0015] (6) When the coating 3 is measured by X-ray fluorescence analysis, excluding oxygen and carbon, and the mass ratio of the constituent elements of the ceramic particles 8 is M1 and the mass ratio of the metal element among the constituent elements of the metal oxide 10 is M2, it is preferable that the following formula (1) is satisfied, more preferably that formula (2) is satisfied, and even more preferably that formula (3) is satisfied. By satisfying this requirement, the ratio of the ceramic particles 8 to the metal oxide 10 falls within a specified range, the thermal expansion of the coating 3 is controlled, and the ceramic particles 8 are less likely to fall off. 0.01×M2≦M1≦0.20×M2…(1) 0.02×M2≦M1≦0.15×M2…(2) 0.04×M2≦M1≦0.10×M2…(3) The mass ratios M1 and M2 can be measured by X-ray fluorescence analysis. Composition analysis by X-ray fluorescence analysis can be performed using an X-ray fluorescence photoelectron spectrometer. The measurement conditions are as follows: the X-ray source is aluminum metal K-alpha radiation, the beam diameter is 100 μm, and the X-ray incident angle to the surface to be analyzed is 45°, and the measurement can be performed by scanning the surface. The mass ratio M1 of the ceramic particles 8 is the sum of the mass ratios of all elements contained in the ceramic particles 8 (excluding oxygen and carbon). When metal oxide 10 contains multiple types of metal elements as constituent elements, mass ratio M2 is the total mass ratio of all metal elements contained in metal oxide 10.

[0016] (7) Characteristics of infrared absorption spectrum Film 3 has an infrared absorption spectrum with a wave number of 650 cm -1 ~900cm -1 The maximum peak intensity at A is the wavenumber 3400 cm -1 When the peak intensity at is B, the following formula (2) is satisfied. B / A<0.1 …(2) In this equation, B / A is 0.01 0.01 Wave number 650cm -1 ~900cm -1 The maximum peak at wavenumber 3400 cm is presumed to be due to ceramic particles 8 contained in the coating 3. -1 It is presumed that the peak at is due to OH of the metal hydroxide. By satisfying the above formula (1), the coated substrate 1 is suitable for use in high temperature ranges or for use in which a hard film is required.

[0017] (8) Percentage of metal elements, percent of carbon (C) When the coating 3 is measured by X-ray photoelectron spectroscopy (XPS), the total element percentage of the metal elements among the constituent elements of the ceramic particles 8 and the metal elements among the constituent elements of the metal oxide 10 is 70 atm% or more, preferably 80 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 element percentage of the total metal elements is 100 atm% minus the element percentage (atm%) of C (carbon), which will be described later. If the composition of the coating 3 is not constant, the requirement for the total element percentage of the metal elements is met as long as the composition of at least a portion of the coating 3 is within the above-mentioned range. ​​The carbon (C) element 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 ensuring the flexibility of the coating 3 and suppressing the propagation of cracks in the coating 3. On the other hand, from the viewpoint of ensuring that the coating 3 functions satisfactorily as an inorganic coating, the carbon (C) element percentage is less than 20 atm%, preferably 15 atm% or less, and more preferably 10 atm% or less. From these viewpoints, the carbon (C) element 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) element 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 aluminum metal K-alpha ray source, 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.

[0018] (9) Structure of the bonding portion between the ceramic particles 8 and the conductive substrate 5 A portion 10A in which amorphous metal oxide 10 is interposed may be present between ceramic particles 8 and conductive substrate 5. In other words, ceramic particles 8 and conductive substrate 5 may be bonded by metal oxide 10. By employing such a structure, separation of ceramic particles 8 from coating 3 is suppressed.

[0019] (10) Crack Cracks may be present in the coating 3. The cracks are visible when the coating 3 is observed from the surface. However, it is desirable that the conductive substrate 5 is not exposed from the crack crevices. In other words, it is desirable that the cracks do not reach the surface of the conductive substrate 5. It is presumed that a surface structure having cracks that do not expose the conductive substrate 5 will enable the structure to flexibly respond to thermal stress while maintaining surface properties.

[0020] (11) Elements contained in the coating 3 When the coating 3 is measured by the TEM-EDS method, the coating 3 preferably contains any of the metal elements that make up the conductive substrate 5 in a proportion of 0.1 mass % to 5 mass % relative to 100 mass % of the metal element that is most abundant among the metal elements that make up the metal oxide 10 in the coating 3. It is presumed that the adhesion between the coating 3 and the conductive substrate 5 is improved when the coating 3 contains a trace amount of the metal element contained in the conductive substrate 5. In order to ensure sufficient adhesion, the ratio of the metal elements constituting the conductive substrate 5 to 100% of the metal elements constituting the metal oxide 10 in the coating 3 is 0.1% or more and 5% or less, preferably 0.2% or more and 3% or less, and more preferably 0.4% or more and 1% or less. When the oxide is composed of two or more metal elements, the total of these elements is taken as 100%. The metal element contained in the conductive base material 5 is preferably at least one selected from the group consisting of Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Pt (platinum), and Pd (palladium). Here, we will show a specific example where this requirement is met. <Example 1 that meets this requirement> For example, assuming that the coating 3 contains magnesium oxide as the metal oxide 10 and the conductive substrate 5 contains copper, this requirement is met in the following cases: Example of analysis results for film 3 Mg 100% Cu 0.1% or more and 5% or less <Example 2 that meets this requirement> For example, assuming that the coating 3 contains aluminum oxide as the metal oxide 10 and the conductive substrate 5 contains copper, this requirement is met in the following cases: Example of analysis results for film 3 Al 100% Cu 0.1% or more and 5% or less <Example 3 that meets this requirement> For example, assuming that the coating 3 contains magnesium oxide and aluminum oxide as the metal oxide 10 and the conductive substrate 5 contains copper, this requirement is met in the following cases: Example of analysis results for film 3 Mg 80% Al 20% Cu 0.1% or more and 5% or less

[0021] By satisfying either the relational expression (3) or (4), stress relaxation can be expected when stress is applied to the coated substrate 1. When two or more types of ceramic particles 8 are present, it is sufficient that any one type of ceramic particles 8 satisfies either of the above relational expressions (3) and (4). Furthermore, when two or more types of metal oxides 10 are present, it is sufficient that any one of the metal oxides 10 satisfies either of the above relational expressions (3) and (4).

[0022] 2. Manufacturing method of coated substrate 1 The method for producing the coated substrate 1 of the present disclosure is not particularly limited. A preferred production method is described below: A preferred production method is a method for producing the coated substrate 1 using a bath liquid 2 containing an organic solvent and iodine. The bath liquid 2 has a water content of less than 5 mass %, contains at least one or more types of metal elements, and contains at least one or more types of ceramic particles 8. The concentration of ceramic particles 8 in the bath liquid 2 is greater than 0 mass % and less than 10 mass %. By applying a voltage while the conductive substrate 5 is immersed in the bath liquid 2, a pre-heat treatment coating containing the metal elements contained in the bath liquid 2 is formed on the conductive substrate 5 on the negative electrode 7 side (cathode side). Thereafter, the film 3 is formed by heat treatment at a temperature of 400° C. or higher for 1 minute or longer.

[0023] (1) Bath liquid 2 The bath liquid 2 preferably contains an organic solvent as a solvent. (1.1) Moisture content To ensure the homogeneity of the coating 3 and to suppress oxidation of the conductive substrate 5, the water content of the bath liquid 2 is set to less than 5% by mass. The water content is preferably less than 0.5% by mass, and more preferably less than 0.1% by mass. The water content may be 0% by mass. The water content of the bath liquid 2 can be determined by GC-MS analysis.

[0024] (1.2) Metallic elements The bath liquid 2 contains at least one metal element. From the viewpoint of allowing the coating 3 to function as a high-quality protective film for the conductive substrate 5, the metal element is preferably at least one selected from the group consisting of Mg (magnesium), Al (aluminum), Ti (titanium), Zr (zirconium), Mo (molybdenum), W (tungsten), V (vanadium), Fe (iron), Cr (chromium), and Co (cobalt). In the manufacturing method of the present disclosure, an oxide film, which is the coating 3, is formed depending on the metal element in the bath liquid 2. The metal element 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 element is eluted from the positive electrode 6 into the bath liquid 2, it becomes easy to control the film formation rate, and it becomes possible to continuously and stably form films on a plurality of substrates 5. When the metal element is supplied to the bath liquid 2 by elution from the positive electrode 6, it is preferable that the positive electrode 6 be at least one type of electrode selected from an Mg electrode and an Al electrode. The metal elements in the bath liquid 2 may be supplied from metal alkoxides and / or inorganic metal compounds. When the metal elements are supplied by dissolving metal alkoxides and / or inorganic metal compounds, 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 also possible to form a film in which a composition ratio is controlled by combining multiple metal elements. Examples of metal alkoxides include aluminum alkoxides and titanium alkoxides. Examples of aluminum alkoxides include aluminum trialkoxides, such as 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 preferably titanium tetraalkoxide. 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 a metal alkoxide and / or an inorganic metal compound, 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. Note that "ppm" stands for "parts per million" and "mg / L." Furthermore, 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.

[0025] (1.3) Iodine The bath liquid 2 contains iodine. By including iodine in the bath liquid 2, film formation can be carried out at a practical speed, and the film 3 tends to be homogeneous. I (iodine) is selected 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 conductive substrate 5. The iodine concentration in the bath liquid 2 is not particularly limited. From the viewpoints of appropriately suppressing the reaction rate, advantageously controlling the uniformity and thickness of the coating 3, and suppressing peeling of the coating 3, the iodine concentration 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" stands for "parts per million" and "mg / L." The iodine concentration in the bath liquid 2 can be determined from the amount of halogen element added when the bath is made up or by ICP-MS analysis of the bath liquid 2.

[0026] (1.4) Organic solvents By using an organic solvent as the solvent for bath liquid 2, gas generation during film formation and oxidation of the conductive substrate 5 itself are suppressed. From the viewpoint of favorable formation of 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 iodine, improving the reactivity of bath liquid 2.

[0027] (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), methylcyclohexanone, etc. Among these, acetone and methyl ethyl ketone are preferred as the ketone from the viewpoint of particularly favorable formation of the coating 3.

[0028] (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.

[0029] (1.5) Ceramic particles 8 For the "ceramic particles 8", the explanation in the section "(3) ceramic particles 8" in "1. coated substrate 1" above applies as is. There are no particular limitations on the concentration of ceramic particles 8 in the bath liquid 2. From the viewpoint of film formation efficiency, the concentration of ceramic particles 8 is preferably greater than 0 mass % and less than 10 mass %, more preferably 0.0001 mass % to 1 mass %, and even more preferably 0.001 mass % to 0.1 mass %.

[0030] (2) Conductive base material 5 For the "conductive substrate 5", the explanation in the section "(1) Conductive substrate 5" in "1. Coated substrate 1" above applies as is.

[0031] (3) Voltage application With the substrate 5 immersed in the bath liquid, a voltage is applied to form a pre-heat-treatment coating containing a metal element on the negative electrode side of the substrate 5. Specifically, the positive electrode 6 and the negative electrode 7 (substrate 5) are immersed in the bath liquid 2, and a potential gradient is generated between the two electrodes. The pre-heat-treatment coating is subjected to a heat treatment, which will be described later, to form the coating 3. Any known conductive substrate can be used as the positive electrode 6. When the metal elements in the bath solution 2 are supplied by elution from the positive electrode 6, the positive electrode 6 is preferably at least one electrode selected from the group consisting of a magnesium alloy Mg electrode and an Al electrode. The shape, thickness, size, etc. of the positive electrode 6 are not particularly limited. The positive electrode 6 may be in the form of, for example, a foil, a plate, a foam, a nonwoven fabric, a mesh, a felt, or an expanded material. The positive electrode 6 and the negative electrode 7 are preferably disposed facing each other. The positive electrode 6 and the negative electrode 7 are connected to a DC power supply, and a potential gradient can be generated between the positive electrode 6 and the negative electrode by the DC power supply. 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 by a power source connected to the positive electrode 6 and the negative electrode 7. From the viewpoint of forming a film at a practical speed, the potential gradient generated between the two electrodes is preferably 10 V or more and 300 V or less, more preferably 20 V or more and 100 V or less, and even more preferably 60 V or more and 80 V or less, in the case of a constant voltage. The application time of the voltage is not particularly limited and is, for example, preferably from 10 seconds to 300 seconds, more preferably from 30 seconds to 240 seconds, and even more preferably from 60 seconds to 180 seconds. The voltage may not be a constant voltage but may be variable in magnitude.

[0032] (4) Heat treatment The temperature of the heat treatment is preferably 400°C or higher and 1300°C or lower, more preferably 500°C or higher and 1250°C or lower, and even more preferably 600°C or higher and 1200°C or lower, from the viewpoint of efficiently chemically changing the metal hydroxide into the metal oxide. The heat treatment time is not particularly limited as long as it is 1 minute or more, and is, for example, preferably 1 minute or more and 240 minutes or less, more preferably 5 minutes or more and 180 minutes or less, and even more preferably 10 minutes or more and 120 minutes or less.

[0033] 3. Effects of the coated substrate 1 of this embodiment According to this embodiment, a novel coated substrate 1 is provided that can be applied to various fields and is expected to have high functionality. For example, it can be used as a material for magnets, coils, electromagnetic steel sheets, laminated cores, etc. According to this embodiment, a novel coated substrate 1 is provided that can be used in an environment accompanied by a temperature change of 100° C. or more. According to this embodiment, a novel coated substrate 1 having high insulating properties and high adhesion of the coating 3 is provided. The coated substrate 1 of this embodiment can be mass-produced using a simple process. The method for producing the coated substrate 1 of this embodiment is a wet film-forming method, and therefore has the potential to be generally applicable to products of various shapes and sizes. [Example]

[0034] The present disclosure will be explained more specifically with reference to examples.

[0035] A.Measuring methods for various physical properties (1) XPS In the following description, the measurement conditions for XPS (X-ray photoelectron spectroscopy) are as follows. [XPS (X-ray photoelectron spectroscopy) measurement conditions] X-ray beam diameter: 100 μmΦ Signal capture angle: 45.0° Pass energy: 140 eV Ar etching for 30 seconds (etching rate: 10 nm / min in SiO2 equivalent)

[0036] (2) X-ray fluorescence analysis The measurement conditions for the X-ray fluorescence analysis are as follows: [X-ray fluorescence analysis measurement conditions] Measuring device name: ZSX Primus2 Measuring diameter: 10mm Semi-quantitative analysis method: SQX analysis

[0037] (3) TEM-EDS method The measurement conditions for the TEM-EDS method are as follows: [TEM-EDS method measurement conditions] Measurement device name: JEM-F200 (JEOL) Accelerating voltage: 200 kV Quantitative method: Cliff-Lorimer method

[0038] (4) FT-IR The FT-IR measurement conditions are as follows: [FT-IR measurement conditions] Measurement method: Single reflection ATR method Accumulation count: 64 times Resolution: 4cm -1 Aperture: 150 μm

[0039] B. Working Example 1. Example 1 (ceramic particles: yttria-stabilized zirconia (YSZ), solvent: acetone, positive electrode 6: aluminum) (1) Preparation of coated substrate 1 A film forming apparatus 11 shown in FIG. 3 was used. An aluminum wire was used as the positive electrode 6. A conductive substrate 5 (SUS304 stainless steel plate) was used as the negative electrode 7. The negative electrode 7 is the conductive substrate 5 on whose surface a coating 3 is 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. Thereafter, a voltage of 80 V was applied for 10 minutes while the positive electrode 6 and negative electrode 7 were immersed, and the aluminum of the anode was dissolved into the bath liquid. YSZ powder was stirred into bath liquid 2, and a positive electrode 6 and a negative electrode 7 were immersed in bath liquid 2. A voltage of 80 V was applied between the positive electrode 6 and the negative electrode 7 for 2 minutes to form a film. The concentration of YSZ in bath liquid 2 was 0.01% by mass. Thereafter, the substrate 5 was removed from the bath liquid 2 and dried. After drying, the ceramic particles 8 had not fallen off from the coating. Furthermore, the coating and the conductive substrate 5 were not peeled off and were well bonded to each other. Thereafter, the conductive substrate 5 on which this coating was formed was heat-treated at 400° C. for 45 minutes to prepare a coated substrate 1.

[0040] (2) Composition of the conductive substrate 5 The stainless steel plate SUS304 contained 30 mass % or more of Fe (iron).

[0041] (3) Film thickness of coating 3 The cross section of the coating 3 was observed with an FIB-SEM. At least a portion with a thickness of 100 nm was confirmed in the coating 3. Furthermore, at this measurement point, the particle diameter of the YSZ particles was 30 nm, which was less than half the thickness of the coating. It was also confirmed that the space between the YSZ particles was made up of amorphous aluminum oxide. Furthermore, Coating 3 contained 43 mass % aluminum, and XPS suggested the presence of bonds between aluminum and oxygen, while FT-IR confirmed that it contained no hydroxyl groups. Therefore, the main component of Coating 3 was aluminum oxide. It was also confirmed that the YSZ particles and the conductive substrate 5 were bonded by aluminum oxide. In other words, there were portions where amorphous aluminum oxide was present between the YSZ particles and the conductive substrate 5.

[0042] (4) Analysis of Coating 3 by X-ray Fluorescence Analysis When the coating 3 was measured by X-ray fluorescence analysis, the mass ratio of Y and Zr, which are the constituent elements of the YSZ particles, excluding oxygen and carbon, was 0.0038 (M1), and the mass ratio of Al, which is the constituent element of the metal oxide, was 0.086 (M2). Therefore, the mass ratio of Zr and the mass ratio of Al satisfied the following relationship: 0.01×M2≦M1≦0.20×M2

[0043] (5) Analysis by infrared absorption spectroscopy When B / A was calculated using the method described above, it was found to be 0.05. Therefore, the peak intensity ratio satisfied the following relational expression. B / A<0.1

[0044] (6) Analysis by X-ray photoelectron spectroscopy The sum of the concentrations of Zr, Y, and O, which are the constituent elements of the YSZ particles, and Al and O, which are the constituent elements of the metal oxide, was 92.3 atm%. The concentration of C (carbon) was 7.8 atm%.

[0045] (7) Observation of film 3 The surface and cross section of the coating 3 were observed with an FIB-SEM. From the surface observation, cracks were observed in the coating 3. However, from the cross-sectional observation, it was confirmed that the cracks did not reach the surface of the conductive substrate 5.

[0046] (8) TEM-EDS analysis of coating 3 The cross section of the coating 3 was observed by TEM-EDS. The coating 3 contained 0.82% Fe, which constitutes the conductive substrate, relative to 100% Al.

[0047] (9) The coated substrate 1 of Example 1 is a novel material, and is expected to be used as a substrate in an environment accompanied by temperature changes of 100°C or more.

[0048] 2. Example 2 (ceramic particles: magnesium oxide (MgO), solvent: acetone, positive electrode 6: aluminum) (1) Preparation of coated substrate 1 A film forming apparatus 11 shown in FIG. 3 was used. An aluminum wire was used as the positive electrode 6. A conductive substrate 5 (copper plate) was used as the negative electrode 7. The negative electrode 7 is the conductive substrate 5 on whose surface a coating 3 is 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. Thereafter, a voltage of 80 V was applied for 10 minutes while the positive electrode 6 and the negative electrode 7 were immersed, and the aluminum of the anode was dissolved into the bath liquid. MgO powder was stirred into bath liquid 2, and a positive electrode 6 and a negative electrode 7 were immersed in bath liquid 2. A voltage of 80 V was applied between the positive electrode 6 and the negative electrode 7 for 2 minutes to form a film. The concentration of MgO in bath liquid 2 was 0.01% by mass. Thereafter, the substrate 5 was removed from the bath liquid 2 and dried. After drying, the ceramic particles 8 had not fallen off from the coating. Furthermore, the coating and the conductive substrate 5 were not peeled off and were well bonded to each other. Thereafter, the conductive substrate 5 on which this coating was formed was heat-treated at 400° C. for 45 minutes to prepare a coated substrate 1.

[0049] (2) Composition of the conductive substrate 5 The copper plate contained 99 mass % or more of Cu (copper).

[0050] (3) Film thickness of coating 3 The cross section of the coating 3 was observed with an FIB-SEM. At least a portion with a thickness of 500 nm was confirmed in the coating 3. Furthermore, at this measurement point, the particle diameter of the MgO particles was 200 nm, which was less than half the thickness of the coating. It was also confirmed that the space between the MgO particles was made up of amorphous aluminum oxide. Furthermore, Coating 3 contained 40 mass % aluminum oxide, and XPS suggested the presence of bonds between aluminum and oxygen, while FT-IR confirmed that it contained no hydroxyl groups. Therefore, the main component of Coating 3 was aluminum oxide. It was also confirmed that the MgO particles and the conductive base material 5 were bonded by aluminum oxide. In other words, there were portions where amorphous aluminum oxide was present between the MgO particles and the conductive base material 5.

[0051] (4) Analysis of Coating 3 by X-ray Fluorescence Analysis When the coating 3 was measured by X-ray fluorescence analysis, the mass ratio of Mg among the constituent elements of the MgO particles was 0.0036 (M1), and the mass ratio of Al among the constituent elements of the metal oxide was 0.074 (M2). Therefore, the mass ratio of Mg and the mass ratio of Al satisfied the following relationship: 0.01×M2≦M1≦0.20×M2

[0052] (5) Analysis by infrared absorption spectroscopy When B / A was calculated using the method described above, it was found to be 0.04. Therefore, the peak intensity ratio satisfied the following relational expression. B / A<0.1

[0053] (6) Analysis by X-ray photoelectron spectroscopy The sum of the concentrations of Mg and O, which are constituent elements of the MgO particles, and Al and O, which are constituent elements of the metal oxide, was 90 atm %. The concentration of C (carbon) was 8.9 atm %.

[0054] (7) Observation of film 3 The surface and cross section of the coating 3 were observed with an FIB-SEM. From the surface observation, cracks were observed in the coating 3. However, from the cross-sectional observation, it was confirmed that the cracks did not reach the surface of the conductive substrate 5.

[0055] (8) TEM-EDS analysis of coating 3 Film 3 was observed by TEM-EDS. Film 3 contained 0.82% Cu, which constitutes the conductive substrate, relative to 100% Al.

[0056] (9) The coated substrate 1 of Example 2 is a novel material, and is expected to be used as a substrate in an environment accompanied by temperature changes of 100°C or more.

[0057] 3. Example 3 (ceramic particles: yttria-stabilized zirconia (YSZ), solvent: acetone, positive electrode 6: magnesium alloy (AZ31)) (1) Preparation of coated substrate 1 A film forming apparatus 11 shown in FIG. 3 was used. A magnesium alloy plate was used as the positive electrode 6. A conductive substrate 5 (stainless steel plate) was used as the negative electrode 7. The negative electrode 7 is the conductive substrate 5 on whose surface a coating 3 is 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. Thereafter, a voltage of 80 V was applied for 10 minutes while the positive electrode 6 and negative electrode 7 were immersed, and the magnesium alloy of the anode was dissolved into the bath liquid. YSZ powder was stirred into bath liquid 2, and a positive electrode 6 and a negative electrode 7 were immersed in bath liquid 2. A voltage of 80 V was applied between the positive electrode 6 and the negative electrode 7 for 2 minutes to form a film. The concentration of YSZ in bath liquid 2 was 0.01% by mass. Thereafter, the substrate 5 was removed from the bath liquid 2 and dried. After drying, the ceramic particles 8 had not fallen off from the coating. Furthermore, the coating 3 and the conductive substrate 5 were not peeled off and were well bonded. Thereafter, the conductive substrate 5 on which this coating was formed was heat-treated at 400° C. for 45 minutes to prepare a coated substrate 1.

[0058] (2) Composition of the conductive substrate 5 The stainless steel plate contained 30 mass % or more of Fe (iron).

[0059] (3) Film thickness of coating 3 The cross section of the coating 3 was observed with an FIB-SEM. At least a portion with a thickness of 100 nm was confirmed in the coating 3. Furthermore, at this measurement point, the particle diameter of the YSZ particles was 30 nm, which was less than half the thickness of the coating. It was also confirmed that amorphous magnesium oxide was present between the YSZ particles. Furthermore, Coating 3 contained 40 mass % magnesium oxide, and XPS indicated the presence of bonds between magnesium and oxygen, while FT-IR confirmed that it contained no hydroxyl groups. Therefore, the main component of Coating 3 was magnesium oxide. It was also confirmed that the YSZ particles and the conductive substrate 5 were bonded by magnesium oxide. In other words, there were portions where amorphous magnesium oxide was present between the YSZ particles and the conductive substrate 5.

[0060] (4) Analysis of Coating 3 by X-ray Fluorescence Analysis When the coating 3 was measured by X-ray fluorescence analysis, the mass ratio of Y and Zr, which are the constituent elements of the YSZ particles, was 0.0038 (M1), and the mass ratio of Mg, which is the constituent element of the metal oxide, was 0.071 (M2). Therefore, the mass ratio of Zr and the mass ratio of Mg satisfied the following relational expression. 0.01×M2≦M1≦0.20×M2

[0061] (5) Analysis by infrared absorption spectroscopy When B / A was calculated using the method described above, it was found to be 0.05. Therefore, the peak intensity ratio satisfied the following relational expression. B / A<0.1

[0062] (6) Analysis by X-ray photoelectron spectroscopy The sum of the concentrations of Y, Zr, and O, which are constituent elements of the YSZ particles, and Mg and O, which are constituent elements of the metal oxide, was 90 atm%. The concentration of C (carbon) was 8.9 atm%.

[0063] (7) Surface observation of coating 3 The surface of the coating 3 was observed with an FIB-SEM. Cracks were observed in the coating 3. However, it was confirmed that the cracks did not reach the surface of the conductive substrate 5.

[0064] (8) TEM-EDS analysis of coating 3 Film 3 was observed by TEM-EDS. Film 3 contained 0.82% Fe, which constitutes the conductive substrate, relative to 100% Mg.

[0065] (9) The coated substrate 1 of Example 3 is a novel material, and is expected to be used as a substrate in an environment accompanied by temperature changes of 100°C or more.

[0066] 4. Example 4 (ceramic particles: alumina (Al2O3), solvent: acetone, positive electrode 6: magnesium alloy (AZ31)) (1) Preparation of coated substrate 1 A film forming apparatus 11 shown in FIG. 3 was used. A magnesium alloy was used as the positive electrode 6. A conductive substrate 5 (copper plate) was used as the negative electrode 7. The negative electrode 7 is the conductive substrate 5 on whose surface a coating 3 is 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. Thereafter, a voltage of 80 V was applied for 10 minutes while the positive electrode 6 and negative electrode 7 were immersed, and the magnesium alloy of the anode was dissolved into the bath liquid. Al2O3 powder was stirred into bath liquid 2, and a positive electrode 6 and a negative electrode 7 were immersed in bath liquid 2. A voltage of 80 V was applied between the positive electrode 6 and the negative electrode 7 for 2 minutes to form a film. The concentration of Al2O3 in bath liquid 2 was 0.01% by mass. Thereafter, the substrate 5 was removed from the bath liquid 2 and dried. After drying, the ceramic particles 8 had not fallen off from the coating. Furthermore, the coating and the conductive substrate 5 were not peeled off and were well bonded to each other. Thereafter, the conductive substrate 5 on which this coating was formed was heat-treated at 400° C. for 45 minutes to prepare a coated substrate 1.

[0067] (2) Composition of the conductive substrate 5 The nickel-plated stainless steel plate contained 30 mass % or more of Fe (iron).

[0068] (3) Film thickness of coating 3 The cross section of the coating 3 was observed with an FIB-SEM. At least a portion with a thickness of 500 nm was confirmed in the coating 3. Furthermore, at this measurement point, the particle diameter of the Al2O3 particles was 200 nm, which was less than half the thickness of the coating. It was also confirmed that amorphous magnesium oxide was present between the Al2O3 particles. It was also confirmed that the coating 3 contained 40 mass % magnesium oxide, which meant that the main component of the coating 3 was magnesium oxide. It was also confirmed that the Al2O3 particles and the conductive base material 5 were bonded by magnesium oxide. In other words, there were portions where amorphous magnesium oxide was present between the Al2O3 particles and the conductive base material 5.

[0069] (4) Analysis of Coating 3 by X-ray Fluorescence Analysis When the coating 3 was measured by X-ray fluorescence analysis, the mass ratio of Al among the constituent elements of the Al2O3 particles was 0.003 (M1), and the total mass ratio of Mg and Al among the constituent elements of the metal oxide was 0.08 (M2). Therefore, the mass ratio of Zr and the total mass ratio of Mg and Al satisfied the following relationship. 0.01×M2≦M1≦0.20×M2

[0070] (5) Analysis by infrared absorption spectroscopy When B / A was calculated using the method described above, it was found to be 0.05. Therefore, the peak intensity ratio satisfied the following relational expression. B / A<0.1

[0071] (6) Analysis by X-ray photoelectron spectroscopy The total concentration of Al and O, which are constituent elements of the Al2O3 particles, and Mg and O, which are constituent elements of the metal oxide, was 90 atm%. The concentration of C (carbon) was 8.9 atm%.

[0072] (7) Surface observation of coating 3 The surface of the coating 3 was observed by FIB-SEM. From the surface observation, cracks were observed in the coating 3. However, from the cross-sectional observation, it was confirmed that the cracks did not reach the surface of the conductive substrate 5.

[0073] (8) TEM-EDS analysis of coating 3 Film 3 was observed by TEM-EDS. Film 3 contained 0.83% Cu, which constitutes the conductive substrate, relative to 100% Mg.

[0074] (9) The coated substrate 1 of Example 4 is a novel material, and is expected to be used as a substrate in an environment accompanied by temperature changes of 100°C or more.

[0075] C. Effects of the Example According to this embodiment, by forming a film (composite film) of ceramic particles and metal oxide on the conductive substrate, the difference in thermal expansion coefficient between the conductive substrate and the film can be alleviated. Furthermore, the coating contains a metal oxide, which makes it possible to provide a coated substrate that is useful for applications in high temperature ranges or where a hard coating is required, compared to composite coatings using hydroxides.

[0076] 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.

[0077] (Addendum) This specification includes the following inventions:

[0078] [1] A coated substrate in which a conductive substrate is coated with a coating, The thickness of the coating is 50 nm or more and less than 100 μm, the coating includes at least one type of ceramic particle; A coated substrate, wherein the ceramic particles are bonded together by an amorphous metal oxide, and the coating is mainly composed of the metal oxide. [2] The coated substrate according to [1], wherein the conductive substrate contains at least one element selected from the group consisting of Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Pt (platinum), and Pd (palladium) in a total amount of 30 mass% or more. [3] At least one location where the thickness of the coating is measured, The coated substrate according to [1] or [2], wherein the particle diameter of the ceramic particles present at the measurement point is equal to or less than half of the film thickness measured at the measurement point. [4] The coated substrate according to any one of [1] to [3], wherein, when the coating is measured by fluorescent X-ray analysis, the following formula (1) is satisfied, where M1 is the mass ratio of the constituent elements of the ceramic particles and M2 is the mass ratio of the metal element among the constituent elements of the metal oxide, excluding oxygen and carbon. 0.01×M2≦M1≦0.20×M2…(1) [5] In the infrared absorption spectrum of the coating, the wave number is 650 cm -1 ~900cm -1 The maximum peak intensity at A is Wave number 3400cm -1 A coated substrate of any one of [1] to [4], which satisfies the following formula (2) when the peak intensity at B / A<0.1 …(2) [6] When the coating was measured by X-ray photoelectron spectroscopy, the sum of the concentration of the constituent elements of the ceramic particles and the concentration of the constituent elements of the metal oxide is 70 atm% or more; The coated substrate according to any one of [1] to [5], wherein the concentration of C (carbon) is 0.1 atm % or more and less than 20 atm %. [7] The coated substrate according to any one of [1] to [6], wherein the metal oxide is present between the ceramic particles and the conductive substrate. [8] When observed from the surface of the coating, cracks are observed in the coating, The coated substrate according to any one of [1] to [7], wherein the cracks do not reach the surface of the conductive substrate. [9] The coated substrate according to any one of [1] to [8], wherein the ceramic particles are at least one selected from the group consisting of MgO, Al2O3, CaF2, AlN, BN, Si3N4, and ZrO2.

[10] The coated substrate according to any one of [1] to [9], wherein the metal oxide comprises at least one selected from the group consisting of Mg (magnesium), Al (aluminum), Si (silicon), Ti (titanium), Zr (zirconium), Cr (chromium), Mn (manganese), Fe (iron), Co (cobalt), Ni (nickel), Mo (molybdenum), V (vanadium), and W (tungsten).

[11] The coated substrate according to any one of [1] to

[10] , wherein, when the coating is measured by TEM-EDS, the coating contains any of the elements constituting the conductive substrate in a proportion of 0.1 mass % to 5 mass % relative to 100 mass % of the element with the largest component among the metal elements constituting the metal oxide.

[12] A method for producing a coated substrate according to any one of [1] to

[11] , using a bath solution containing an organic solvent and iodine as a solvent, the bath liquid has a water content of less than 5% by mass, contains at least one metal element, and contains the ceramic particles; The concentration of the ceramic particles in the bath liquid is greater than 0% by mass and less than 10% by mass, A voltage is applied to the conductive substrate while the conductive substrate is immersed in the bath solution to form a pre-heat treatment film containing a metal element on the negative electrode side of the conductive substrate, and then A method for producing a coated substrate, comprising a step of heat treating the substrate at a temperature of 400°C or higher for 1 minute or longer. [Explanation of symbols]

[0079] 1...Coated substrate 2…Bath liquid 3...coating 5...Conductive base material 6...Positive electrode 7...Negative electrode 8...ceramic particles 10...metal oxides 11...Film deposition equipment

Claims

1. A coated substrate in which a conductive substrate is coated with a coating, The thickness of the coating is 50 nm or more and less than 100 μm, the coating includes at least one type of ceramic particle; A coated substrate, wherein the ceramic particles are bonded together by an amorphous metal oxide, and the coating is mainly composed of the metal oxide.

2. 2. The coated substrate according to claim 1, wherein the conductive substrate contains at least one element selected from the group consisting of Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Pt (platinum), and Pd (palladium) in a total amount of 30 mass% or more.

3. At least one location where the thickness of the coating is measured, 3. The coated substrate according to claim 1, wherein the particle diameter of the ceramic particles present at the measurement point is equal to or less than half of the film thickness measured at the measurement point.

4. When the coating was measured by fluorescent X-ray analysis, the mass ratio of the constituent elements of the ceramic particles, excluding oxygen and carbon, was M １ and the mass ratio of the metal element among the constituent elements of the metal oxide is M ２ The coated substrate according to claim 1 or claim 2, which satisfies the following formula (1) when 0.01×M ２ ≦M １ ≦0.20×M ２ …(1)

5. In the infrared absorption spectrum of the coating, the wave number is 650 cm －１ ~900cm －１ The maximum peak intensity at A, Wave number 3400cm －１ 3. The coated substrate according to claim 1 or claim 2, wherein the following formula (2) is satisfied when the peak intensity at the peak is defined as B: B / A<0.1...(2)

6. When the coating was measured by X-ray photoelectron spectroscopy, the sum of the concentration of the constituent elements of the ceramic particles and the concentration of the constituent elements of the metal oxide is 70 atm% or more; 3. The coated substrate according to claim 1, wherein the concentration of C (carbon) is 0.1 atm % or more and less than 20 atm %.

7. 3. The coated substrate according to claim 1, wherein the metal oxide is present between the ceramic particles and the conductive substrate.

8. When observed from the surface of the coating, cracks are observed in the coating, The coated substrate of claim 1 or claim 2, wherein the cracks do not reach the surface of the conductive substrate.

9. The ceramic particles are MgO, Al ２ O ３ , CaF ２ , AlN, BN, Si ３ N ４ , and ZrO ２ The coated substrate according to claim 1 or claim 2, wherein the coated substrate is at least one selected from the group consisting of:

10. 3. The coated substrate according to claim 1, wherein the metal oxide comprises at least one selected from the group consisting of Mg (magnesium), Al (aluminum), Si (silicon), Ti (titanium), Zr (zirconium), Cr (chromium), Mn (manganese), Fe (iron), Co (cobalt), Ni (nickel), Mo (molybdenum), V (vanadium), and W (tungsten).

11. 3. The coated substrate according to claim 1 or claim 2, wherein, when the coating is measured by TEM-EDS, the coating contains any of the elements constituting the conductive substrate in a proportion of 0.1 mass % to 5 mass % relative to 100 mass % of the element that is most abundant among the metal elements constituting the metal oxide.

12. 3. The method for producing a coated substrate according to claim 1 or 2, wherein a bath solution containing an organic solvent and iodine as a solvent is used, the bath liquid has a water content of less than 5 mass %, contains at least one metal element, and contains the ceramic particles; The concentration of the ceramic particles in the bath liquid is greater than 0 mass% and less than 10 mass%, A voltage is applied to the conductive substrate while the conductive substrate is immersed in the bath solution to form a pre-heat treatment film containing a metal element on the negative electrode side of the conductive substrate, and then A method for producing a coated substrate, comprising a step of heat treating the substrate at a temperature of 400°C or higher for 1 minute or longer.

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