Article having coating, composition, and method for manufacturing article having coating

Abstract

To provide an article having a zinc oxide-containing coating that has improved a light blocking function for a ray of light in a wavelength region on the order of 600 nm-700 nm.SOLUTION: An article has a coating satisfying the following (1)-(3) on a substrate. (1) In a gray scale image of a cross-sectional STEM image, a lamination structure is confirmed in which low luminance areas and high luminance areas are alternately laminated. (2) In cross-sectional observation by STEM-EDX, oxygen, zinc, and cobalt are detected. (3) In cross-sectional observation by STEM-EDX, the EDX intensity ratio between cobalt and zinc (Zn / Co) in an area observed as the low luminance areas is higher than the EDX intensity ratio between cobalt and zinc (Zn / Co) in an area observed as the high luminance areas.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to coated articles, compositions and methods for making coated articles. [Background technology]

[0002] Patent documents 1 to 5 and non-patent documents 1 and 2 disclose zinc oxide-containing coatings and methods for producing the same. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-147695 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-205811 [Patent Document 3] Japanese Patent Application Publication No. 7-182939 [Patent Document 4] Patent No. 5288464 specification [Patent Document 5] Japanese Patent Application Publication No. 2019-152702 [Non-patent literature]

[0004] [Non-Patent Document 1] Japan Society for the Promotion of Science, Committee 166 on Transparent Oxide High-Electron Materials, Technical Revision 2nd Edition of Transparent Conductive Films (2006) [Non-patent document 2] K. Sorab, et al. Appl. Phys. Lett., 37(5), 1 September 1980 Summary of the Invention [Problem to be solved by the invention]

[0005] Zinc oxide-containing coatings are used in a wide range of fields due to their transparency and heat resistance. Furthermore, in recent years, the ultraviolet ray blocking function of zinc oxide-containing coatings has attracted attention. For example, Patent Document 1 discloses a glass container whose outer surface is coated with a zinc oxide-containing coating, thereby achieving high visible light transmittance and ultraviolet ray blocking function. Furthermore, Patent Document 1 describes that, regarding the heat resistance characteristic of zinc oxide-containing coatings, no change in transmittance or the like was observed even after prolonged exposure to high temperatures of 300°C or higher (see paragraph 0048 of Patent Document 1).

[0006] Various methods are known for forming zinc oxide-containing coatings (see Non-Patent Document 1). Specific examples of methods for forming zinc oxide-containing coatings include a method of forming the zinc oxide-containing coating by a vacuum film formation method such as sputtering, a method of forming the zinc oxide-containing coating as a coating containing an organic or inorganic binder and zinc oxide particles (see Patent Document 2), a chemical vapor deposition (CVD) method (see Non-Patent Document 2), a spin coating method, and a spray pyrolysis method (see Patent Documents 3 to 5).

[0007] Regarding the light-blocking function of zinc oxide-containing coatings, the band gap inherent in zinc oxide theoretically makes it difficult to block light rays of 380 nm or longer. Therefore, in recent years, efforts have been made to expand the light-blocking wavelength range by adding other metal components to the zinc component. For example, Patent Document 6 describes a zinc oxide-containing coating doped with a foreign metal, which was prepared using a composition containing dialkyl zinc and a foreign metal precursor (organometallic compound). The zinc oxide-containing coating exhibited improved UV-A (315 nm to 380 nm) light-blocking efficiency while maintaining good transparency (see Examples in Patent Document 5). However, in the Examples in Patent Document 6, the absorption edge shift achieved by doping with the foreign metal was limited to 376 nm (see Table 2 in Patent Document 6), leaving room for improvement in the light-blocking ability for light rays in the longer wavelength range. Meanwhile, for various applications, including pharmaceutical applications, there has been a demand for coatings applied to various articles that have improved light-blocking capabilities for light rays in the visible light range of approximately 600 nm to 700 nm. For example, methylergometrine maleate injection, a uterotonic hemostatic agent, has specific absorption in the wavelength range of 450 nm to 750 nm (see page 2256 of the 18th Edition of the Japanese Pharmacopoeia, Reference Ultraviolet-Visible Absorption Spectrum). Furthermore, the above-mentioned drugs are known to be decomposed by light. For example, in order to protect such drugs using the light-blocking function of a zinc oxide-containing coating, it is desirable to improve the light-blocking function of the zinc oxide-containing coating against light in the wavelength range of approximately 600 to 700 nm.

[0008] An object of one aspect of the present invention is to provide an article having a zinc oxide-containing coating that has improved light-blocking properties against light in the wavelength range of about 600 nm to 700 nm. [Means for solving the problem]

[0009] One aspect of the present invention is as follows. [1] An article having a coating film on a substrate that satisfies the following (1) to (3): (1) In the grayscale image of the cross-sectional STEM (Scanning Transmission Electron Microscope), a layered structure in which low-brightness regions and high-brightness regions are alternately stacked is confirmed. (2) Oxygen, zinc, and cobalt were detected in cross-sectional observations using STEM-EDX (Scanning Transmission Electron Microscope-Energy Dispersive X-ray Spectroscopy). (3) In cross-sectional observation by STEM-EDX, the EDX intensity ratio of cobalt to zinc (Zn / Co) in the region observed as the low brightness region is higher than the EDX intensity ratio (Zn / Co) in the region observed as the high brightness region. [2] The product according to [1], wherein the film thickness of the low-luminance region is in the range of 10.0 nm or more and 300.0 nm or less, and the film thickness of the high-luminance region is in the range of 10.0 nm or more and 100.0 nm or less. [3] The article according to [1] or [2], wherein in the laminated structure, the total number of layers in the low-brightness region is 5 to 15, and the total number of layers in the high-brightness region is 5 to 15. [4] The article according to any one of [1] to [3], wherein the ratio of the average transmittance of the coating in the wavelength range of 600 nm to 700 nm divided by the average transmittance in the wavelength range of 700 nm to 800 nm is 0.90 or less. [5] The film thickness of the low-brightness region is in the range of 10.0 nm to 300.0 nm, and the film thickness of the high-brightness region is in the range of 10.0 nm to 100.0 nm, In the laminated structure, the total number of layers in the low-luminance region is 5 to 15, and the total number of layers in the high-luminance region is 5 to 15, The article according to any one of [1] to [4], wherein the ratio of the average transmittance of the coating in the wavelength range of 600 nm to 700 nm divided by the average transmittance in the wavelength range of 700 nm to 800 nm is 0.90 or less. [6] Formula (1): Formula (1):R 1 -Zn-R 2 (In formula (1), R 1 and R 2 each independently represents a linear or branched alkyl group having 1 to 8 carbon atoms. and an organozinc compound represented by the formula: The following formula (2): [ka] (In formula (2), R 3 and R 4 each independently represents a linear or branched alkyl group having 1 to 8 carbon atoms. a β-diketone metal compound represented by the formula: A composition comprising: [7] In formula (2), R 3 and R 4 and each represent a methyl group. [8] The composition according to [6] or [7], further comprising an organic solvent. [9] The composition according to [8], wherein the organic solvent is one or more organic solvents selected from the group consisting of aromatic hydrocarbon solvents and aromatic electron-donating solvents.

[10] In formula (2), R 3 and R 4 represent a methyl group, The composition according to any one of [6] to [9], further comprising one or more organic solvents selected from the group consisting of aromatic hydrocarbon solvents and aromatic electron-donating solvents. A method for producing an article having a coating on a substrate, the method comprising applying the composition according to any one of [6] to

[10] onto the substrate. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide an article having a zinc oxide-containing coating that has improved light blocking function against light in the wavelength range of about 600 nm to 700 nm. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows the transmission spectrum of the coating formed in Example 1. [Figure 2] 1 shows the transmission spectrum of the coating formed in Example 2. [Figure 3] 1 shows the transmission spectrum of the coating formed in Example 3. [Figure 4] 1 shows the transmission spectrum of the coating formed in Example 4. [Figure 5] 1 shows the transmission spectrum of the coating formed in Comparative Example 1. [Figure 6] 1 shows the transmission spectrum of the coating formed in Reference Example 1. [Figure 7] 1 shows the transmission spectrum of the coating formed in Comparative Example 2. [Figure 8] 1 shows a grayscale image (256 gradations) and brightness analysis results of a cross-sectional STEM image of a randomly selected portion of the coating formed in Example 2 across the entire thickness direction. [Figure 9] 1 shows a grayscale image (256 gradations) and brightness analysis results of a cross-sectional STEM image of the entire thickness direction of a randomly selected portion of the coating formed in Comparative Example 2. [Figure 10] 1 shows the results of cross-sectional observation by TEM-EDX and EDX intensity analysis of the entire thickness direction of a randomly selected portion of the coating formed in Example 2. [Figure 11] 1 shows the results of cross-sectional observation by TEM-EDX and the results of EDX intensity analysis of a coating formed in Comparative Example 2 across the entire thickness direction at a randomly selected location. [Figure 12] The film thickness and total number of layers were determined for low-brightness and high-brightness regions in a grayscale image (256 gradations) of a cross-sectional STEM image of a randomly selected portion of the coating formed in Example 2 across the entire thickness direction. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Goods] One aspect of the present invention relates to an article having, on a substrate, a coating that satisfies the following (1) to (3): (1) In the grayscale image of the cross-sectional STEM image, a layered structure in which low-brightness regions and high-brightness regions are alternately stacked is confirmed. (2) Oxygen, zinc, and cobalt were detected in cross-sectional observations using STEM-EDX. (3) In cross-sectional observation by STEM-EDX, the EDX intensity ratio of cobalt to zinc (Zn / Co) in the region observed as the low brightness region is higher than the EDX intensity ratio (Zn / Co) in the region observed as the high brightness region.

[0013] As a result of extensive research, the present inventors have newly discovered that a coating that satisfies the above (1) to (3) can block visible light on the long wavelength side. The present inventors speculate that the reason for this is as follows. Since the above coating satisfies the above (2), it is presumed to be a mixture film of zinc oxide and cobalt oxide. If the mixture film of multiple oxides is a homogeneous film in which the layered structure as described in the above (1) is not observed, it is thought that the optical properties such as light-blocking ability are predominantly exhibited by the component present at a high concentration. Therefore, if zinc oxide is present at a high concentration in such a homogeneous film, the optical properties of the zinc oxide will be predominant, and the optical properties of the coating will be similar to those of a zinc oxide film, and it is thought that it will be difficult to improve the light-blocking function against light in the wavelength range of about 600 nm to 700 nm. In contrast, the coating satisfies both (2) and (3), and is therefore thought to have regions where zinc oxide is present in high concentrations (low luminance regions) and regions where it is present in low concentrations (high luminance regions).The low luminance regions exhibit the optical properties of zinc oxide predominantly, and the high luminance regions are less affected by the optical properties of zinc oxide and exhibit the optical properties of cobalt oxide, which is thought to enable the coating to exhibit excellent light blocking properties for light in the wavelength range of about 600 nm to 700 nm. However, the above is merely speculation, and the present invention is not limited to the speculation described in this specification.

[0014] The above-mentioned article will be described in more detail below. Hereinafter, the above (1) to (3) will be referred to as film properties (1) to (3). The film properties (1) to (3) are measured at randomly selected points on a cross section of the coating to be measured at randomly selected positions.

[0015] Cross-sectional STEM images in the present invention and this specification are taken under the following observation conditions: As an apparatus for obtaining cross-sectional STEM images and performing STEM-EDX analysis, for example, an apparatus described in the Examples section below can be used. Observation magnification: 100,000 times Accelerating voltage during observation: 20 kV

[0016] <Coating> (Membrane properties (1)) Satisfying film property (1) means that the brightness ratio (high brightness MIN / low brightness MAX) is 1.2 or greater, where the arithmetic mean of the brightness values ​​of high-brightness regions, which are regions that appear brighter than adjacent regions in a 256-level grayscale image (if multiple high-brightness regions are observed across the entire thickness of the coating, the arithmetic mean of the region with the lowest arithmetic mean of brightness values) is defined as "high brightness MIN" and the arithmetic mean of the brightness values ​​of low-brightness regions, which are regions that appear darker than adjacent regions (if multiple low-brightness regions are observed across the entire thickness of the coating, the arithmetic mean of the region with the highest arithmetic mean of brightness values) is defined as "low brightness MAX." Such a brightness ratio is preferably 1.3 or greater, with 1.4 or greater, 1.5 or greater, 1.6 or greater, 1.7 or greater, 1.8 or greater, and 1.9 or greater being more preferred in that order. The brightness ratio may be, for example, 3.0 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, or 2.0 or less, and may exceed the range exemplified here.

[0017] In the laminated structure, the film thickness of the low-brightness region and the film thickness of the high-brightness region are not particularly limited. The film thickness of the low-brightness region can be, for example, in the range of 10.0 nm to 300.0 nm. The film thickness of the high-brightness region can be, for example, in the range of 10.0 nm to 100.0 nm. The film thickness of each region can be determined at randomly selected locations in a grayscale image of a cross-sectional STEM image.

[0018] In the laminated structure, the high-brightness regions and the low-brightness regions are alternately laminated, and one or more high-brightness regions and one or more low-brightness regions are included. The total number of low-brightness regions and the total number of high-brightness regions in the laminated structure are not particularly limited. The total number of low-brightness regions can be, for example, 5 to 15 layers. The total number of high-brightness regions can be, for example, 5 to 15 layers. The total number of low-brightness regions and the total number of high-brightness regions can be the same or different.

[0019] (Membrane properties (2)) Satisfying the film physical property (2) means that oxygen, zinc, and cobalt are detected in cross-sectional observation by STEM-EDX. The region for cross-sectional observation by STEM-EDX is a randomly selected region covering the entire thickness direction of the cross-section of the coating to be measured. In the STEM-EDX EDX intensity spectrum (vertical axis: intensity, horizontal axis: distance (i.e., thickness)), the range of intensity indicating the presence of each element (i.e., intensity above the lower detection limit) can be continuous throughout the entire thickness direction (excluding both end regions, which may contain measurement errors, etc.). EDX intensity analysis can be performed by line analysis.

[0020] (Membrane properties (3)) Satisfying film characteristic (3) means that the EDX intensity ratio (Zn / Co) of cobalt to zinc in regions observed as low-brightness regions in cross-sectional observation by TEM-EDX is higher than the EDX intensity ratio (Zn / Co) in regions observed as high-brightness regions. The EDX intensity ratio (Zn / Co) of each region is calculated as the ratio of the arithmetic mean of Zn intensity to the arithmetic mean (also simply referred to as "average") of cobalt intensity in that region. If the EDX intensity ratio (Zn / Co) in the low-brightness region is defined as the "EDX low-brightness region" and the EDX intensity ratio (Zn / Co) in the high-brightness region is defined as the "EDX high-brightness region," then the ratio "EDX low-brightness region / EDX high-brightness region" can be, for example, 1.5 or more and 3.5 or less. When calculating the above ratio, the "EDX low brightness region" is the EDX intensity ratio (Zn / Co) in the region with the lowest EDX intensity ratio (Zn / Co) when multiple low brightness regions are observed across the entire thickness of the coating, and the "EDX high brightness region" is the EDX intensity ratio (Zn / Co) in the region with the highest EDX intensity ratio (Zn / Co) when multiple high brightness regions are observed across the entire thickness of the coating.

[0021] (film thickness) The thickness of the coating can be adjusted appropriately depending on the intended use of the article and is not particularly limited. A thicker coating tends to exhibit better light-blocking properties. The coating thickness can be, for example, 50 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, 450 nm or more, 500 nm or more, 550 nm or more, 600 nm or more, 650 nm or more, or 700 nm or more. From the viewpoint of coating transparency, the coating thickness is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, even more preferably 2 μm or less, and even more preferably 1 μm or less. The coating thickness can be measured using a stylus-type surface profiler. An example of a measuring device is the measuring device described in the Examples section below.

[0022] (Light blocking function) An example of an index of light-blocking function is the ratio (600nm-700nm / 700nm-800nm) obtained by dividing the average transmittance in the wavelength range of 600nm to 700nm by the average transmittance in the wavelength range of 700nm to 800nm. This ratio is preferably 0.90 or less, more preferably 0.85 or less, and more preferably 0.80 or less, 0.75 or less, 0.70 or less, 0.65 or less, 0.60 or less, 0.55 or less, and 0.50 or less. The ratio can be, for example, 0.20 or more, 0.25 or more, 0.30 or more, or 0.35 or more. The transmittance of the coating at various wavelengths can be measured using a commercially available spectrophotometer. The present inventors speculate that the coating satisfying the film properties (1) to (3) contributes to the coating being able to exhibit the light-blocking function in the above range. Since a lower ratio is preferable from the viewpoint of blocking light in the wavelength range of 600 nm to 700 nm, the coating may have a ratio below the above range.

[0023] The average transmittance of the coating in the wavelength range of 600 to 700 nm is preferably 85.0% or less, with 80.0% or less, 75.0% or less, 70.0% or less, 65.0% or less, 60.0% or less, 55.0% or less, 50.0% or less, 45.0% or less, and 40.0% or less being more preferred in this order. The average transmittance of the coating in the wavelength range of 600 to 700 nm can be, for example, 0.0% or more, more than 0.0%, 0.1% or more, 1.0% or more, 5.0% or more, 10.0% or more, 15.0% or more, 20.0% or more, 25.0% or more, or 30.0% or more. The average transmittance of the coating in the wavelength range of 700 to 800 nm can be, for example, in the range of 70.0 to 95.0%, but is not limited to such range.

[0024] <Base material> Examples of the substrate of the above-mentioned article include various articles for which a light-blocking function is desired. The material constituting the substrate is not particularly limited, and examples include metal, metal oxide, glass, concrete, various plastics, paper, wood, etc., and may be a composite material containing one or more of these. The shape of the substrate may be a plate-like shape, a curved shape, or a three-dimensional shape such as a container shape. The substrate may have an uneven surface. An example of the substrate is a container described below. For example, in the pharmaceutical field, it is desirable to block light in the wavelength range that pharmaceuticals absorb in order to maintain the quality of pharmaceuticals. Therefore, it is desirable for containers used for storing and / or distributing pharmaceuticals to have excellent light-blocking properties. For example, the above coating is suitable as a coating for imparting a light-blocking function to the outer and / or inner surfaces of such containers (i.e., substrates). The above coating is also suitable as a coating for imparting a light-blocking function to the outer and / or inner surfaces of containers (i.e., substrates) used for storing and / or distributing cosmetics, foods, etc.

[0025] The article can have the coating on at least a portion of the substrate. Furthermore, the coating can be located, for example, as the outermost layer of the article at the location where the coating is provided. When the substrate has a front surface and a back surface, the article can have the coating on, for example, a portion or the entire surface of either or both of the front surface and the back surface. Furthermore, the coating may be provided on at least a portion or the entire surface of the side surface of the substrate. The substrate on which the coating is provided may be a substrate alone, or may be a substrate on which one or more layers are laminated.

[0026] The article can be any of various articles to which a light-blocking function is to be imparted. Specific examples of such articles include glass windows, building materials, containers, etc. Examples of containers include the containers described above.

[0027] [Composition] One aspect of the present invention relates to a composition containing an organozinc compound represented by formula (1) and a β-diketone metal compound represented by formula (2).

[0028] The composition can be a coating composition. In the present invention and this specification, the term "coating composition" refers to a composition that is applied onto a substrate or the like to form a coating.

[0029] During the film-forming process using the above composition, the organozinc compound represented by formula (1) can produce zinc oxide by reacting with, for example, water in the air. Therefore, the above composition can form a coating containing zinc oxide. On the other hand, the inventors believe that the β-diketone metal compound represented by formula (2) can produce cobalt oxide by reacting with the above composition during the film-forming process. Therefore, it is presumed that the coating formed using the above composition contains zinc oxide and cobalt oxide. Furthermore, the above composition is suitable as a coating composition for forming the above-described coating.

[0030] The above composition will be described in more detail below.

[0031] <Organic zinc compounds> The organozinc compound is represented by the following formula (1). Formula (1):R 1 -Zn-R 2

[0032] Formula (1) will be explained in more detail below.

[0033] In formula (1), R 1 and R 2 R each independently represents a linear or branched alkyl group having 1 to 8 carbon atoms. The organozinc compound represented by formula (1) is a dialkylzinc. 1 and R 2 In one embodiment, represent the same alkyl group, and in another embodiment, represent different alkyl groups.

[0034] Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, a 2-hexyl group, a heptyl group, a 2-ethylhexyl group, and an octyl group.

[0035] The organozinc compound represented by formula (1) preferably has an alkyl group having 1 to 3 carbon atoms as the alkyl group, and is readily available, and is therefore particularly suitable for use as diethylzinc (i.e., R 1 and R 2 are more preferably ethyl groups).

[0036] The above organozinc compounds can be synthesized by known methods and are also available as commercial products.

[0037] <β-diketone metal compounds> The β-diketone metal compound is represented by the following formula (2).

[0038] [ka]

[0039] Formula (2) shows the structure of a β-diketone metal compound complex (cobalt complex). 3 and alkyl groups represented by R 4 Depending on the alkyl group represented by the formula (2), tautomerization may occur to form a β-diketone metal compound with a different bonding state between the oxygen atom and the cobalt atom. Such a β-diketone metal compound may take the form of a salt compound represented by the following formula (2)-1. In the present invention and this specification, the β-diketone metal compound represented by formula (2) also includes the form in which it exists as such a salt compound. R in formula (2) 3 and R 4 is R in Equation (2). 3 and R4 is synonymous with.

[0040] [ka]

[0041] The formula (2) will be explained in more detail below.

[0042] In formula (2), R 3 and R 4 R each independently represents a linear or branched alkyl group having 1 to 8 carbon atoms. 3 and R 4 In one embodiment, R represents the same alkyl group, and in another embodiment, R represents different alkyl groups. 3 In one embodiment, each of the three R represents the same alkyl group, in another embodiment, each of the three R represents a different alkyl group, and in another embodiment, two of the R represent the same alkyl group and the remaining one represents a different alkyl group. 4 The same is true for .

[0043] Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, a 2-hexyl group, a heptyl group, a 2-ethylhexyl group, and an octyl group.

[0044] The β-diketone metal compound represented by formula (2) preferably has an alkyl group having 1 to 3 carbon atoms as the alkyl group, and is easily available. 3 and R 4 More preferably, all of are methyl groups.

[0045] Specific examples of the β-diketone metal compound represented by formula (2) include cobalt(III) acetylacetonate and tris(dipivaloylmethanato)cobalt(III).

[0046] The above β-diketone metal compounds can be synthesized by known methods and are also available as commercial products.

[0047] The composition contains one or more of the organic zinc compounds and the β-diketone metal compounds, and typically further contains a solvent. Only one solvent may be used, or two or more solvents may be mixed in any ratio. The solvent is preferably an organic solvent, more preferably an aromatic organic solvent, and even more preferably one or more organic solvents selected from the group consisting of aromatic hydrocarbon solvents and aromatic electron-donating solvents. Specific examples of aromatic hydrocarbon solvents include benzene, toluene, ethylbenzene, xylene, mesitylene, and cyclohexylbenzene. Specific examples of aromatic electron-donating solvents include anisole.

[0048] The content of the organozinc compound in the composition is preferably defined as a content expressed in mass % relative to the total amount of the composition being 100 mass % from the viewpoints of producing a coating having a sufficient thickness, producing a transparent coating having excellent visible light transmittance, improving pot life, and preventing nozzle clogging due to solvent evaporation. Specifically, the content of the organozinc compound in the composition is preferably 15 mass % or less, more preferably 12 mass % or less, and even more preferably 9 mass % or less, and 6 mass % or less, relative to the total amount of the composition being 100 mass %. Furthermore, the content is preferably 1 mass % or more, more preferably 2 mass % or more, and even more preferably 3 mass % or more. The content is preferably within the above range from the viewpoints of producing a coating having a sufficient thickness, producing a transparent coating having excellent visible light transmittance, improving pot life, and preventing nozzle clogging due to solvent evaporation.

[0049] The content of the β-diketone metal compound in the composition is defined as the percentage of cobalt atoms relative to the total of zinc atoms contained in the organozinc compound and cobalt atoms contained in the β-diketone metal compound, from the viewpoint of controlling the light-blocking function of a coating formed using the composition. From this viewpoint, the percentage is preferably greater than 10 atomic %, and more preferably 15 atomic % or more, 20 atomic % or more, 30 atomic % or more, 40 atomic % or more, 50 atomic % or more, and 60 atomic % or more. From the viewpoint of improving the transparency of the coating formed, the percentage is preferably 90 atomic % or less, more preferably 80 atomic % or less, and even more preferably 70 atomic % or less.

[0050] The composition may contain only the above-mentioned components, or may contain one or more known components in any proportion.

[0051] By using the above composition, a coating containing zinc oxide can be formed, which exhibits excellent light-blocking properties against light rays in a wide wavelength range.

[0052] [Method of manufacturing an article having a coating] One aspect of the present invention relates to a method for producing an article having a coating on a substrate, the method comprising applying the above-described composition onto the substrate.

[0053] According to the above-mentioned production method, a coating containing zinc oxide can be formed by hydrolysis of the organozinc compound represented by formula (1) contained in the above-mentioned composition. The above-mentioned production method is a method capable of forming a coating containing zinc oxide without a binder, as opposed to a method of forming a coating containing zinc oxide using a coating liquid containing zinc oxide particles and a binder. Furthermore, the above-mentioned production method also makes it possible to firmly adhere zinc oxide to the substrate surface to be coated. Furthermore, compared to a coating containing zinc oxide formed using zinc oxide particles and a binder, the coating formed by the above-mentioned production method is preferable in terms of exhibiting high heat resistance. Additionally, as described above, the coating formed by the above-mentioned production method can contain cobalt oxide provided by the β-diketone metal compound represented by formula (2). The above-mentioned production method is suitable as a method for producing the above-mentioned article.

[0054] The above manufacturing method will be described in more detail below.

[0055] <Application of composition> The substrate to which the composition is applied is as described above. Known methods such as droplet application, electrostatic application, spin coating, and dip coating can be used to apply the retarding composition. Droplet application is preferred because it does not require specific substrate shapes. Specific examples of droplet application include spray application and mist CVD (chemical vapor deposition) methods. Spray application is a method in which a coating solution is sprayed from a nozzle. Commercially available spray application devices and spray application devices with known configurations can be used as spray application devices. The mist CVD method is a method in which a coating solution is misted using an ultrasonic mist generator or the like, and this mist is supplied to the substrate surface. Commercially available mist CVD application devices and mist CVD application devices with known configurations can be used as mist CVD application devices.

[0056] The composition can be applied in an atmosphere containing water and oxygen. The relative humidity of the "atmosphere containing water and oxygen" can be, for example, 20% or more and 100% or less. From the viewpoint of smooth film formation, the relative humidity of the "atmosphere containing water and oxygen" is preferably 40% or more and 100% or less, and more preferably 50% or more and 100% or less, or 50% or more and 90% or less. The oxygen concentration in the "atmosphere in which water and oxygen are present" can be, for example, 5% by volume or more and 50% by volume or less, 10% by volume or more and 40% by volume or less, or 15% by volume or more and 30% by volume or less, with the total amount of gas in the atmosphere (excluding water vapor) being 100% by volume. The "atmosphere containing water and oxygen" can be, for example, air, preferably air containing water at a relative humidity within the above range. Alternatively, the "atmosphere containing water and oxygen" may be an atmosphere of a mixed gas of nitrogen, oxygen, and water instead of the air described above. As is well known, the oxygen concentration in air is about 20% by volume relative to the total amount of gas excluding water vapor. The composition can be applied, for example, under atmospheric pressure or under pressure, preferably under atmospheric pressure in the presence of water and oxygen. Applying the composition under atmospheric pressure is preferred because it is convenient in terms of the equipment.

[0057] The composition can be applied to a substrate by heating the substrate. The substrate temperature during application can be, for example, less than 400°C, and can be controlled by a known heating means such as a heater. In the present invention and this specification, the term "substrate temperature" refers to the temperature of the substrate surface onto which the coating liquid (specifically, the composition) is applied. If necessary, the substrate temperature can be set to a predetermined temperature, the solvent can be dried, and then heating can be performed at the predetermined temperature to form zinc oxide. It is also believed that this heating can form an oxide containing cobalt atoms. It is also possible to set the solvent drying temperature and the substrate temperature for subsequent zinc oxide formation to be the same, so that solvent drying and zinc oxide formation can be performed simultaneously. The substrate temperature can also be appropriately set, such as by increasing the temperature in multiple stages, depending on the type of solvent contained in the coating liquid.

[0058] The ambient temperature of the coating atmosphere can be, for example, 50°C or lower. The composition is preferably applied at an ambient temperature of 50°C or lower and a substrate temperature of less than 400°C. From the viewpoint of promoting the crystallization of zinc oxide in the coating, the ambient temperature of the coating is preferably 0°C or higher and 40°C or lower, and the substrate temperature is preferably 100°C or higher and 250°C or lower. Furthermore, the cycle of "coating-drying-heating" can be performed once or twice or more times. Repeating this cycle twice or more times can increase the thickness of the coating. Various coating conditions, such as the amount of the composition applied, the coating speed, the size of droplets ejected from the spray nozzle when spray coating is performed, the distance between the substrate and the spray nozzle during coating, and the spray pressure, can be set depending on the concentration of the organozinc compound and the β-diketone metal compound in the composition, the specifications of the coating device used, the thickness of the coating to be formed, and the like. [Example]

[0059] The present invention will be described below based on examples, but the present invention is not limited to the embodiments shown in the examples.

[0060] The preparation of the following coating solutions was carried out in a nitrogen gas atmosphere, and all solvents were dehydrated before use.

[0061] [Examples 1 to 4] As an organozinc compound represented by formula (1), diethylzinc (R 1 and R 2 is an ethyl group), and cobalt(III) acetylacetonate (M is a cobalt atom, R is an ethyl group) was used as the β-diketone compound represented by formula (2). 3 and R 4 is a methyl group). To 50.0 g of anisole, 0.9 g to 2.9 g of diethylzinc was added, and then cobalt(III) acetylacetonate was added in an amount such that the percentage of the cobalt atoms relative to the total of the zinc atoms contained in the diethylzinc and the cobalt atoms contained in the cobalt(III) acetylacetonate would be the value shown in the "Amount Added" column in Table 1, and the mixture was thoroughly stirred to obtain a coating liquid (coating composition). The coating solution obtained above was filled into a spray bottle of a spray coating device. The spray coating device used was the spray coating device (fixed nozzle type) described in JP 2011-170979 A. A 5 cm x 5 cm glass substrate (Corning EAGLEXG) was placed on a substrate holder as the substrate and heated to a substrate temperature of 200°C. After that, the coating solution was sprayed (spray coated) from the spray nozzle at 1 ml / min and a nitrogen carrier gas of 13 L / min for 15 to 30 minutes under atmospheric pressure, an ambient temperature of 25°C, and a relative humidity of 50% in the presence of water. The spray nozzle used was an Atmax Nozzle AM6 manufactured by ATOMAX Corporation. The droplets ejected from the spray nozzle had a size range of 3 to 20 μm, and the distance between the spray nozzle and the substrate was 23 cm. Spray coating was performed to form a coating on the substrate.

[0062] [Comparative Example 1] To 50.0 g of anisole, 2.3 g of diethylzinc alone was added, and the mixture was thoroughly stirred to obtain a coating solution. The coating solution was spray coated by the method described above to form a coating on the substrate.

[0063] [Reference example 1] To 30.0 g of anisole, 3.0 g of cobalt (III) acetylacetonate alone was added, and the mixture was thoroughly stirred to obtain a coating liquid. The coating solution was spray coated by the method described above to form a coating on the substrate.

[0064] Comparative Example 2 5.2 g of zinc (II) acetylacetonate was added to 50.0 g of anisole, and then cobalt (III) acetylacetonate was added in an amount such that the percentage of the cobalt atoms relative to the total cobalt atoms contained in cobalt (III) acetylacetonate was the value shown in the "Amount Added" column in Table 1, and the mixture was thoroughly stirred to obtain a coating solution. The coating solution was spray coated by the method described above to form a coating on the substrate.

[0065] [Film thickness measurement] The thickness of the coating formed on the substrate in each of Examples 1 to 4, Comparative Example 1, Reference Example 1, and Comparative Example 2 was measured using a stylus surface profiler (DektakXT-S manufactured by Bruker Nano).

[0066] [Transmittance measurement] The transmission spectra of the coatings formed on the substrates of Examples 1 to 4, Comparative Example 1, Reference Example 1, and Comparative Example 2 were measured using a spectrophotometer manufactured by JASCO Corporation, and the average transmittance in the wavelength range of 600 nm to 700 nm and the average transmittance in the wavelength range of 700 nm to 800 nm were calculated. Furthermore, the ratio (600 nm to 700 nm / 700 nm to 800 nm) was calculated from these average transmittances.

[0067] The transmission spectra measured for Examples 1 to 4, Comparative Example 1, Reference Example 1, and Comparative Example 2 are shown in FIGS.

[0068] The results are shown in Table 1. As shown in Table 1, the coatings formed in Examples 1 to 4 have a lower ratio (600 nm to 700 nm / 700 nm to 800 nm) than the coating formed in Comparative Example 1 (a coating formed using a coating liquid containing a zinc source) and the coating formed in Comparative Example 2 (a coating formed using a coating liquid containing a zinc source and a cobalt source). These results confirm that the coatings formed in Examples 1 to 4 have a superior light-blocking function against light in the wavelength range of 600 nm to 700 nm compared to the coatings formed in Comparative Examples 1 and 2. The coating formed in Reference Example 1 is a coating formed using a coating liquid containing only a cobalt source.

[0069] [Table 1]

[0070] [Evaluation of film properties (1)] Figure 8 shows a grayscale image (256 levels) of a cross-sectional STEM image of the entire thickness direction of a randomly selected portion of the coating formed in Example 2, along with the results of brightness analysis. Figure 8 also shows a portion of the brightness analysis results for low-brightness and high-brightness regions. The brightness analysis was performed using the free software ImageJ as image processing software.

[0071] Table 2 shows the maximum and minimum arithmetic mean brightness values ​​of the low brightness regions and the high brightness regions observed in the cross-sectional STEM image shown in FIG.

[0072] [Table 2]

[0073] Figure 9 shows a grayscale image (256 levels) and brightness analysis results of a cross-sectional STEM image of the entire thickness direction of a randomly selected portion of the coating formed in Comparative Example 2. Figure 9 also shows a portion of the brightness analysis results for low-brightness and high-brightness regions. The brightness analysis was performed using the free software ImageJ as image processing software.

[0074] Table 3 shows the maximum and minimum arithmetic mean brightness values ​​of the low-brightness regions and the maximum and minimum arithmetic mean brightness values ​​of the high-brightness regions observed in the cross-sectional STEM image shown in Figure 9. As described above, satisfying film property (1) means that the brightness ratio (high brightness MIN / low brightness MAX) is 1.2 or higher. Therefore, the coating formed in Comparative Example 2 does not satisfy film property (1).

[0075] [Table 3]

[0076] [Evaluation of film properties (2) and (3)] Figure 10 shows the results of cross-sectional observation by TEM-EDX and the results of EDX intensity analysis of the entire thickness direction of a randomly selected portion of the coating formed in Example 2. The EDX intensity analysis was performed by line analysis. Figure 10 also shows a portion of the EDX intensity analysis results for low-brightness and high-brightness regions. The minimum EDX intensity ratio (Zn / Co) among the multiple low-brightness regions was higher than the maximum EDX intensity ratio (Zn / Co) among the multiple high-brightness regions. The ratio "EDX low-brightness region / EDX high-brightness region" was 3.942 / 1.768 = approximately 2.2.

[0077] In the above evaluation, a JEOL JEM-2010MX transmission electron microscope was used, and a JEOL EM-Z02210T JEC EDX microscope was used. The observation conditions were as described above, and the brightness was manually adjusted to a level that was easy to see.

[0078] From the above results, it can be confirmed that the coating formed in Example 2 satisfies the film properties (1) to (3). Furthermore, the transmission spectra (FIGS. 1, 3, and 4) of the coatings formed in Examples 1, 3, and 4 have spectral shapes similar to the transmission spectrum (FIG. 2) of the coating formed in Example 2, and therefore it can be confirmed that the coatings formed in Examples 1, 3, and 4 also satisfy the film properties (1) to (3) like the coating formed in Example 2. As described above, the coatings formed in Examples 1 to 4 satisfy the film properties (1) to (3).

[0079] FIG. 11 shows the results of cross-sectional observation by TEM-EDX and the results of EDX intensity analysis of the entire thickness direction of a randomly selected portion of the coating formed in Comparative Example 2. The EDX intensity analysis was performed by line analysis. FIG. 11 also shows a portion of the EDX intensity analysis results for the low-brightness and high-brightness regions. In the table at the bottom of FIG. 11, the Zn / Co ratio in the low-brightness region in the first row is lower than the Zn / Co ratio in the high-brightness region in the second row and the Zn / Co ratio in the high-brightness region in the fourth row. Therefore, the coating formed in Comparative Example 2 does not satisfy film property (3) either.

[0080] [Thickness of each region and total number of layers] Figure 12 shows the results of determining the film thickness and total number of layers for low-brightness and high-brightness regions in a grayscale image (256 gradations) of a cross-sectional STEM image of the entire thickness direction of a randomly selected portion of the coating formed in Example 2. The film thickness analysis was performed using the free software ImageJ as image processing software. [Industrial Applicability]

[0081] One aspect of the present invention is useful in various technical fields where a light-blocking function is desired.

Claims

1. An article having a coating on a substrate that satisfies the following (1) to (3): (1) In the grayscale image of the cross-sectional STEM image, a layered structure in which low-brightness regions and high-brightness regions are alternately stacked is confirmed. (2) Oxygen, zinc, and cobalt were detected in cross-sectional observations using STEM-EDX. (3) In cross-sectional observation by STEM-EDX, the EDX intensity ratio (Zn / Co) of cobalt to zinc in the region observed as the low brightness region is higher than the EDX intensity ratio (Zn / Co) in the region observed as the high brightness region.

2. 2. The article according to claim 1, wherein the film thickness of the low-luminance region is in the range of 10.0 nm to 300.0 nm, and the film thickness of the high-luminance region is in the range of 10.0 nm to 100.0 nm.

3. The article according to claim 1 , wherein in the laminated structure, the total number of layers in the low-luminance region is 5 to 15, and the total number of layers in the high-luminance region is 5 to 15.

4. 2. The article according to claim 1, wherein the ratio of the average transmittance of the coating in the wavelength range of 600 nm to 700 nm divided by the average transmittance in the wavelength range of 700 nm to 800 nm is 0.90 or less.

5. the film thickness of the low-luminance region is in the range of 10.0 nm to 300.0 nm, and the film thickness of the high-luminance region is in the range of 10.0 nm to 100.0 nm, In the laminated structure, the total number of layers in the low-luminance region is 5 to 15, and the total number of layers in the high-luminance region is 5 to 15, 2. The article according to claim 1, wherein the ratio of the average transmittance of the coating in the wavelength range of 600 nm to 700 nm divided by the average transmittance in the wavelength range of 700 nm to 800 nm is 0.90 or less.

6. The following formula (1): Formula (1): R １ -Zn-R ２ (In formula (1), R １ and R ２ each independently represents a linear or branched alkyl group having 1 to 8 carbon atoms. and an organozinc compound represented by the formula: The following formula (2): 【Chemical 1】 (In formula (2), R ３ and R ４ each independently represents a linear or branched alkyl group having 1 to 8 carbon atoms. a β-diketone metal compound represented by the formula: A composition comprising:

7. In formula (2), R ３ and R ４ The composition according to claim 6 , wherein each of

8. The composition of claim 6 further comprising an organic solvent.

9. The composition according to claim 8, wherein the organic solvent is one or more organic solvents selected from the group consisting of aromatic hydrocarbon solvents and aromatic electron donating solvents.

10. In formula (2), R ３ and R ４ represent a methyl group, 7. The composition of claim 6, further comprising one or more organic solvents selected from the group consisting of aromatic hydrocarbon solvents and aromatic electron donating solvents.

11. A method for producing an article having a coating on a substrate, the method comprising applying the composition according to any one of claims 6 to 10 onto the substrate.

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