Coating solution for film formation and method for manufacturing an article having a zinc oxide-containing coating.

Abstract

To provide a zinc oxide-containing coating that demonstrates a superior shielding function against ultraviolet radiation in the wavelength domain of the near-ultraviolet region between 370 nm and 390 nm.SOLUTION: A coating composition comprises an organic zinc compound represented by the formula (1), and an organic bismuth compound represented by the formula (2). In formula (1), R1 and R2 independently represent a C1-7 linear or branched alkyl group. In formula (2), R3, R4 and R5 independently represent a C1-4 linear or branched alkyl group.

Description

[Technical Field]

[0001] The present invention relates to a coating composition and a method for producing an article having a zinc oxide-containing coating. [Background technology]

[0002] An example of a coating with ultraviolet shielding properties is a zinc oxide-containing coating (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2008-105313 [Patent Document 2] Japanese Patent Application Publication No. 8-143331 [Overview of the project] [Problems that the invention aims to solve]

[0004] Coatings that offer excellent UV-A shielding in the near-ultraviolet wavelength range of 370nm to 390nm are useful in various applications, including pharmaceutical-related applications. However, zinc oxide-containing coatings tend to have inferior UV shielding capabilities in the aforementioned wavelength range.

[0005] One aspect of the present invention aims to provide a zinc oxide-containing coating that can exhibit excellent shielding function against ultraviolet light in the near-ultraviolet wavelength range of 370 nm to 390 nm. [Means for solving the problem]

[0006] As a result of diligent research, the inventors have newly discovered that a zinc oxide-containing film formed using the following coating composition can exhibit excellent shielding function against ultraviolet light in the wavelength range of 370 nm to 390 nm.

[0007] That is, one aspect of the present invention is as follows. [1] The following formula (1): [ka] (In formula (1), R 1 and R 2 (Each of these independently represents a linear or branched alkyl group with 1 to 7 carbon atoms.) An organozinc compound represented by, The following equation (2): [ka] (In formula (2), R 3 , R 4 and R 5 (Each of these independently represents a linear or branched alkyl group with 1 to 4 carbon atoms.) An organic bismuth compound represented by, A coating composition containing the following: [2] The coating composition according to [1], wherein the bismuth element content in the organobismuth compound is in the range of 1 to 60% by mass relative to the zinc element content in the organozinc compound. [3] The coating composition according to [1] or [2], wherein the organozinc compound is diethylzinc. [4] The coating composition according to any one of [1] to [3], wherein the above organic bismuth compound is trimethylbismuth. [5] The bismuth element content in the above organic bismuth compound is in the range of 1 to 60% by mass relative to the zinc element content in the above organic zinc compound. The above organozinc compound is diethylzinc, and The above organic bismuth compound is trimethylbismuth, as described in any one of [1] to [4]. A method for producing an article having a zinc oxide-containing coating, comprising applying a coating composition described in any of [6][1] to [5] onto a substrate. [7] The manufacturing method according to [6], wherein the coating is performed at a substrate temperature of 400°C or lower. [8] The manufacturing method according to [6] or [7], wherein the above coating is carried out in air. [9] The manufacturing method according to any one of [6] to [8], wherein the above coating is carried out by a droplet coating method.

[10] The manufacturing method according to any one of [6] to [9], wherein the film thickness of the zinc oxide-containing film is 300 nm or more and 1 μm or less.

[11] The manufacturing method according to any one of [6] to

[10] , wherein the film thickness of the zinc oxide-containing film is 500 nm or more and 1 μm or less.

[12] The transmittance characteristics of the zinc oxide-containing film are the transmittance at a wavelength of 370 nm is 20.0% or less, the transmittance at a wavelength of 380 nm is 60.0% or less, and the transmittance at a wavelength of 390 nm is 80.0% or less, The manufacturing method according to any one of [6] to

[11] .

[13] The above coating is carried out by a droplet coating method in air at a substrate temperature of 400 °C or less, the film thickness of the zinc oxide-containing film is 300 nm or more and 1 μm or less, the transmittance characteristics of the zinc oxide-containing film are the transmittance at a wavelength of 370 nm is 20.0% or less, the transmittance at a wavelength of 380 nm is 60.0% or less, and the transmittance at a wavelength of 390 nm is 80.0% or less, The manufacturing method according to any one of [6] to

[11] .

[14] The manufacturing method according to

[13] , wherein the film thickness of the zinc oxide-containing film is 500 nm or more and 1 μm or less. [Advantages of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide a zinc oxide-containing film that can exhibit an excellent shielding function against ultraviolet rays in the wavelength range of 370 nm to 390 nm. [Embodiments for Carrying Out the Invention]

[0009] [Coating Composition] One aspect of the present invention relates to a coating composition containing an organozinc compound represented by the above formula (1) and an organobismuth compound represented by the above formula (2).

[0010] In the present invention and this specification, the "coating composition" means a composition that is applied onto a substrate or the like to form a film. During the film-forming process using the above coating composition, for example, by reacting with water in the air, the organozinc compound represented by the formula (1) can generate zinc oxide. Therefore, according to the above coating composition, a zinc oxide-containing film can be formed. On the other hand, the inventors consider that the organobismuth compound represented by the formula (2) can generate bismuth oxide, for example, by reacting with oxygen in the air during the film-forming process using the above coating composition. The inventors speculate that the bismuth oxide thus generated contributes to the ability of the zinc oxide-containing film formed using the above coating composition to exhibit an excellent shielding function against ultraviolet rays in the wavelength range of 370 nm to 390 nm. However, the speculation described in this specification does not limit the present invention.

[0011] Hereinafter, the above coating composition will be described in more detail.

[0012] <Organozinc compound> The above organozinc compound is represented by the following formula (1).

[0013]

Chemical formula

[0014] In formula (1), R 1 and R 2 each independently represent a linear or branched alkyl group having 1 to 7 carbon atoms. The organozinc compound represented by the formula (1) is dialkylzinc. R 1 and R 2 represent the same alkyl group in one form and different alkyl groups in another form.

[0015] Specific examples of the alkyl groups mentioned above include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, tert-pentyl group, hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, 2-hexyl group, heptyl group, and the like.

[0016] The above organozinc compounds are R 1 Alkyl and R represented by 2 The alkyl group represented by is preferably an alkyl group having 1 to 3 carbon atoms. The above organozinc compound is readily available, so diethylzinc (i.e., R 1 and R 2 It is more preferable that all of them are ethyl groups.

[0017] The above organozinc compounds can be synthesized by known methods and are also available commercially.

[0018] <Organobismuth compounds> The above organic bismuth compound is represented by the following formula (2).

[0019] [ka]

[0020] In formula (2), R 3 , R 4 and R 5 Each of these independently represents a linear or branched alkyl group having 1 to 4 carbon atoms. The organobismuth compound represented by formula (2) is trialkylbismuth. 3 , R 4 and R 5 In one form, all three represent the same alkyl group; in another form, two represent the same alkyl group and one represents a different alkyl group; and in yet another form, all three represent different alkyl groups.

[0021] Specific examples of the alkyl groups mentioned above include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, etc. The above organobismuth compound is R 3 Alkyl alkyl groups represented by R 4 Alkyl and R represented by 5 The alkyl group represented by preferably has an alkyl group having 1 to 3 carbon atoms, and more preferably has an alkyl group having 1 or 2 carbon atoms. The above organobismuth compound is readily available, so trimethylbismuth (i.e., R 3 , R 4 and R 5 It is even more preferable that all of them are methyl groups.

[0022] As described above, the zinc oxide-containing film formed using the above coating composition is presumed to contain bismuth oxide produced by the reaction of the above organic bismuth compound. If bismuth oxide itself is added as a component of the coating composition, the coating composition will become a suspension, which may cause clogging of the nozzle of the coating apparatus. In contrast, the above organic bismuth compound can provide a uniform solution, making it possible to apply the above coating composition without causing clogging of the nozzle of the coating apparatus during the film formation process.

[0023] The above organozinc compounds can be synthesized by known methods and are also available commercially.

[0024] The above coating composition contains one or more of the above organozinc compounds and the above organobismuth compounds, and usually further contains a solvent. The solvent is not particularly limited and examples include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, and petroleum ether; aromatic hydrocarbon solvents such as benzene, toluene, ethylbenzene, xylene, mesitylene, and cyclohexylbenzene; and ether solvents such as 1,2-diethoxyethane, diethyl ether, diisopropyl ether, glyme, diglyme, triglyme, dioxane, tetrahydrofuran, and anisole. In addition, only one solvent may be used, or two or more may be mixed in any proportion. Considering the solubility of the above organozinc compounds and the above organobismuth compounds, and the volatility of the solvent, xylene and mesitylene are preferred as solvents.

[0025] The concentration of the organozinc compound in the above coating composition is preferably 15% by mass or less, more preferably 14% by mass or less, and still more preferably 13% by mass or less, and 12% by mass or less, based on 100% by mass of the total composition. Furthermore, the concentration is preferably, for example, 1% by mass or more, more preferably 2% by mass or more, and still more preferably 3% by mass or more. The above concentration is preferable from the viewpoint of producing a zinc oxide-containing coating with sufficient thickness, producing a transparent zinc oxide-containing coating with excellent visible light transmittance, and suppressing clogging of the nozzle due to pot life and solvent evaporation.

[0026] Regarding the concentration of the organic bismuth compound in the above coating composition, the bismuth element content in the organic bismuth compound is preferably 1% by mass or more relative to the zinc element content in the organic zinc compound, and is more preferably 5% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, and 45% by mass or more, in that order. From the viewpoint of further improving the shielding function of the zinc oxide-containing film formed using the above coating composition against ultraviolet rays in the wavelength range of 370 nm to 390 nm, it is preferable that the bismuth element content in the organic bismuth compound is within the above range. Furthermore, from the viewpoint of increasing the transparency of the formed zinc oxide-containing film, the bismuth element content in the organic bismuth compound is preferably 60% by mass or less, and more preferably 55% by mass or less, relative to the zinc element content in the organic zinc compound.

[0027] The above coating composition may contain only the above components, or it may contain one or more known components in any proportion.

[0028] By using the above coating composition, a zinc oxide-containing film can be formed. The zinc oxide-containing film thus formed can exhibit excellent shielding function against ultraviolet light in the wavelength range of 370 nm to 390 nm.

[0029] [Method for manufacturing an article having a zinc oxide-containing coating] One aspect of the present invention relates to a method for producing an article having a zinc oxide-containing coating, which includes applying the above-mentioned coating composition onto a substrate.

[0030] According to the above manufacturing method, a zinc oxide-containing film can be formed by hydrolysis of the organozinc compound represented by formula (1) contained in the coating composition. This manufacturing method allows for the formation of a zinc oxide-containing film without a binder, unlike methods that use a coating solution containing zinc oxide particles and a binder. Furthermore, this manufacturing method allows for the strong adhesion of zinc oxide to the substrate surface. Moreover, the zinc oxide-containing film formed by this manufacturing method is preferable to a zinc oxide-containing film formed using zinc oxide particles and a binder, as it exhibits higher heat resistance. In addition, as previously mentioned, the zinc oxide-containing film formed by this manufacturing method is presumed to contain bismuth oxide derived from the organozinc compound represented by formula (2). This may contribute to the zinc oxide-containing film formed by this manufacturing method exhibiting excellent shielding function against ultraviolet light in the near-ultraviolet wavelength range of 370 nm to 390 nm. For example, in the pharmaceutical field, UV-A shielding is required to maintain the quality of pharmaceuticals. Therefore, it is desirable that containers used for storing and / or distributing pharmaceuticals have excellent UV-A light-blocking properties. For example, the above coating composition can be used to form a film on the outer and / or inner surface of such a container to impart UV-A light-blocking properties. The above coating composition can also be used to form a film on the outer and / or inner surface of containers used for storing and / or distributing cosmetics, food, etc. to impart UV-A light-blocking properties.

[0031] The above manufacturing method will be explained in more detail below.

[0032] <Circuit board> The substrate to which the above coating composition is applied is not particularly limited, as long as it is an article to which you wish to impart ultraviolet shielding functionality. The material constituting the substrate is also not particularly limited, and examples include metal, metal oxide, glass, concrete, various plastics, paper, wood, etc., and a composite material containing one or more of these may also be used. The shape of the substrate may be plate-like, curved, or even a three-dimensional shape such as a container. The substrate may have irregularities on its surface. An example of a substrate is the container described above.

[0033] The article manufactured by the above manufacturing method may have the zinc oxide-containing coating on at least a portion of the substrate. Furthermore, the zinc oxide-containing coating may be positioned, for example, as the outermost layer of the article in the area where the coating is provided. If the substrate has a front and back surface, the article may have the zinc oxide-containing coating on, for example, a portion or the entire surface of either one or both of the front and back surfaces. Alternatively, the zinc oxide-containing coating may be provided on at least a portion or the entire surface of the side surface of the substrate. The substrate may be a base material alone, or it may have one or more layers provided on the base material.

[0034] <Application of coating composition> As a method for applying the above coating composition, known methods such as droplet coating, electrostatic coating, spin coating, and dip coating can be used. Droplet coating is preferred because it is not limited by the shape of the substrate. Specific examples of droplet coating include spray coating and mist CVD (Chemical Vapor Deposition). Spray coating is a method of spraying the coating liquid from a nozzle. As the spray coating apparatus, commercially available spray coating apparatuses and spray coating apparatuses with known configurations can be used. Mist CVD is a method of atomizing the coating liquid using an ultrasonic mist generator or the like, and supplying this mist to the substrate surface. As the mist CVD coating apparatus, commercially available mist CVD coating apparatuses and mist CVD coating apparatuses with known configurations can be used.

[0035] The above coating 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% to 100%. From the viewpoint of smooth formation of the zinc oxide-containing film, the relative humidity of the "atmosphere containing water and oxygen" is preferably 40% to 100%, and more preferably 50% to 100% or 50% to 90%. The oxygen concentration in an "atmosphere containing water and oxygen" can be, for example, 5% to 50% by volume, 10% to 40% by volume, or 15% to 30% by volume, with the total amount of gas in the atmosphere (excluding water vapor) being 100% by volume. The "atmosphere in which water and oxygen are present" can be, for example, air, and preferably air containing water equivalent to the relative humidity within the above range. Alternatively, the "atmosphere in which water and oxygen are present" may be an atmosphere of a mixed gas of nitrogen, oxygen, and water instead of the above air. 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 coating composition described above can be applied, for example, under atmospheric pressure or under pressurized conditions, preferably under atmospheric pressure, in an atmosphere in which water and oxygen are present. Performing the application under atmospheric pressure is preferable because it is simpler in terms of equipment.

[0036] The above coating composition can be applied to a substrate by heating the substrate. The substrate temperature during application can be, for example, 400°C or less, and the substrate temperature can be controlled by known heating means such as a heater. In this invention and specification, "substrate temperature" refers to the temperature of the substrate surface on which the coating liquid (more specifically, the above coating composition) is applied. If necessary, the substrate temperature can be set to a predetermined temperature, the solvent can be dried, and then heating for zinc oxide formation can be performed at the predetermined temperature. It is also presumed that bismuth oxide can be formed by this heating. It is also possible to set the solvent drying temperature and the substrate temperature for subsequent zinc oxide formation to the same temperature, and perform solvent drying and zinc oxide formation simultaneously. The substrate temperature can be set appropriately, such as by raising the temperature in multiple stages depending on the type of solvent contained in the coating liquid.

[0037] The ambient temperature of the coating environment can be, for example, 50°C or lower. It is preferable to coat the coating composition with an ambient temperature of 50°C or lower and a substrate temperature of 400°C or lower. From the viewpoint of promoting the crystallization of zinc oxide in the zinc oxide-containing film, the ambient temperature for coating is preferably 0°C to 40°C, and the substrate temperature is preferably 100°C to 250°C. Furthermore, the "coating-drying-heating" cycle can be considered as one cycle, and the number of such cycles can be one or two or more. By repeating the cycle two or more times, the thickness of the zinc oxide-containing film can be increased. The coating amount and coating speed of the coating composition can be adjusted according to the concentration of the organozinc compound and the organobismuth compound in the coating composition, the specifications of the coating equipment used, and the desired thickness of the zinc oxide-containing film to be formed. Additionally, the thickness of the formed zinc oxide-containing film can be controlled by adjusting the spray pressure (e.g., diffusion pressure and / or atomization pressure) when using a spray coating method. The spray pressure can be, for example, between 0.01 MPa and 0.10 MPa, but is not limited to this range.

[0038] <Zinc oxide containing coating> (film thickness) The thickness of the zinc oxide-containing coating on the article manufactured by the above manufacturing method can be adjusted as appropriate depending on the application of the article, and is not particularly limited. Thicker zinc oxide-containing coatings tend to exhibit better ultraviolet shielding function. The thickness of the zinc oxide-containing coating 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. Furthermore, from the viewpoint of transparency of the coating, the thickness of the zinc oxide-containing coating is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. The thickness can be measured by a stylus-type surface shape measuring device. An example of a measuring device is the measuring device described in the Examples section below.

[0039] (UV shielding function) As an indicator of ultraviolet shielding function, the transmittance measured at wavelengths in the ultraviolet region can be cited. The transmittance of the zinc oxide-containing coating at various wavelengths can be measured using a commercially available spectrophotometer. The lower the transmittance at the measured wavelength, the better the function in shielding light at that wavelength. The zinc oxide-containing coating exhibits excellent shielding function against ultraviolet light in the wavelength range of 370 nm to 390 nm.

[0040] The transmittance of the zinc oxide-containing coating at a wavelength of 370 nm is preferably 20.0% or less, and more preferably in the order of 18.0% or less, 15.0% or less, 12.0% or less, 10.0% or less, 8.0% or less, 5.0% or less, 2.0% or less, and 1.0% or less, and can also be, for example, greater than 0% or 0.1% or more. The transmittance of the zinc oxide-containing coating at a wavelength of 380 nm is preferably 60.0% or less, more preferably 50.0% or less, 40.0% or less, and 30.0% or less, in that order. It can also be, for example, greater than 0%, 1.0% or more, 5.0% or more, 10.0% or more, or 15.0% or more. The transmittance of the zinc oxide-containing coating at a wavelength of 390 nm is preferably 80.0% or less, more preferably 70.0% or less, and more preferably 60.0% or less, and can also be, for example, greater than 0%, 1.0% or more, 10.0% or more, 20.0% or more, 30.0% or more, 40.0% or more, or 50.0% or more.

[0041] The wavelength range for UV-A is 320nm to 400nm. The wavelengths of 370nm, 380nm, and 390nm mentioned above are all included in the UV-A wavelength range. Regarding the shielding function of ultraviolet light in the UV-A wavelength range, the zinc oxide-containing coating may have, for example, a transmittance of 1.0% or less, 0.8% or less, or 0.4% or less at a wavelength of 350nm, a transmittance of 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, or 1.0% or less at a wavelength of 360nm, and / or a transmittance of 85.0% or less, 80.0% or less, 75.0% or less, or 70.0% or less at a wavelength of 400nm. The transmittance at 350nm and 360nm may be, for example, 0%, 0% or more, or greater than 0%. The transmittance at a wavelength of 400 nm can be, for example, 0%, 0% or more, greater than 0%, 30.0% or more, or 50.0% or more.

[0042] The articles manufactured by forming a zinc oxide-containing coating using the above manufacturing method are not particularly limited, as long as they are articles to which ultraviolet shielding functionality is to be imparted. A specific example is the container described earlier. [Examples]

[0043] The present invention will be described below based on examples. However, the present invention is not limited to the embodiments shown in the examples.

[0044] The physical properties of the zinc oxide-containing coatings described below were measured using the following measuring device.

[0045] Film thickness was measured using a stylus-type surface profile analyzer (DektakXT-S, Bruker Nano).

[0046] Transmittance measurements were performed using a spectrophotometer manufactured by JASCO, and the transmittances at various wavelengths listed in Table 1 were determined.

[0047] [Synthesis Example 1 (Synthesis of Trimethylbismuth)] A 200 mL four-necked flask equipped with a reflux condenser and a stirring bar was thoroughly purged with nitrogen, and 73.9 g of methyllithium diethyl ether solution (2.78 g of methyllithium (126.3 mmol)) was added and cooled to 0°C. A mixture of 18.7 g of bismuth tribromide (41.6 mmol) and 38.8 g of THF was added at the same temperature, and the temperature was then raised to 20°C and stirring was continued for 1 hour to complete the reaction. The reaction solution obtained above was subjected to vacuum distillation to obtain 40.3 g of "Fraction 1" (trimethylbismuth concentration 8.2% by mass: trimethylbismuth 3.3 g, THF 23.6 g, diethyl ether 13.4 g) and 9.6 g of "Fraction 2" (trimethylbismuth concentration 12.2% by mass: trimethylbismuth 1.2 g, THF 7.9 g, diethyl ether 0.5 g).

[0048] [Example 1] <Preparation of coating solution (coating composition)> The coating solutions described below were prepared under a nitrogen gas atmosphere, and all solvents were dehydrated and degassed before use. The coating solution was obtained by mixing 15.0 g of fraction 1 obtained in Synthesis Example 1 with 1.2 g (4.8 mmol) of trimethylbismuth, 20.4 g of xylene, and 3.8 g (31.0 mmol) of diethylzinc, and stirring thoroughly. In the above coating solution, the bismuth element content in trimethylbismuth (organobismuth compound) is 50% by mass relative to the zinc element content in diethylzinc (organozinc compound).

[0049] <Formation of zinc oxide-containing coating> The coating solution obtained above was filled into a spray bottle of a spray deposition apparatus (rCoater, manufactured by Asahi Sanac Co., Ltd.). A 5cm x 5cm glass substrate (Eagle XG, manufactured by Corning) was placed in a substrate holder and heated to a substrate temperature of 200°C. Then, under atmospheric pressure, in an atmosphere of 25°C and 60% relative humidity with water present, the coating solution was sprayed from the spray nozzle of the spray deposition apparatus at a spraying rate of 1.0 ml / min. The spray pressure (both diffusion pressure and atomization pressure) was set to 0.07 MPa. Five spray coatings were performed to obtain glass substrates with a zinc oxide-containing coating with a film thickness of 410 nm. The spray nozzle did not clog in any of the five spray coatings.

[0050] [Example 2] Except for setting the spray pressure (both diffusion pressure and atomization pressure) to 0.04 MPa, a zinc oxide-containing film was formed using the method described in Example 1, and a glass substrate with a zinc oxide-containing film thickness of 970 nm was obtained.

[0051] [Comparative Example 1] <Preparation of coating solution (coating composition)> The following coating solutions were prepared under a nitrogen gas atmosphere, and all solvents were dehydrated and degassed before use. A coating solution was obtained by thoroughly stirring 3.8 g (31.0 mmol) of diethylzinc and 34.2 g of xylene.

[0052] <Formation of zinc oxide-containing coating> A zinc oxide-containing film was formed using the method described in Example 1, except for the coating solution obtained above, to obtain a glass substrate with a zinc oxide-containing film thickness of 700 nm.

[0053] Table 1 shows the transmittances at various wavelengths obtained for each of Example 1, Example 2, and Comparative Example 3.

[0054] [Table 1]

[0055] The coating compositions used to form zinc oxide-containing films in Examples 1 and 2 contain an organic bismuth compound represented by formula (2). In contrast, the coating composition used to form zinc oxide-containing films in Comparative Example 1 does not contain an organic bismuth compound represented by formula (2). From the results shown in Table 1, it can be confirmed that the zinc oxide-containing films formed in Examples 1 and 2 exhibit superior shielding function against ultraviolet light in the wavelength range of 370 nm to 390 nm compared to the zinc oxide-containing film formed in Comparative Example 1. [Industrial applicability]

[0056] One aspect of the present invention is useful in various technical fields where ultraviolet shielding is desired.

Claims

1. The following formula (1): 【Chemistry 1】 (In formula (1), R １ and R ２ (Each of these independently represents a linear or branched alkyl group with 1 to 7 carbon atoms.) An organozinc compound represented by, The following formula (2): 【Chemistry 2】 (In formula (2), R ３ , R ４ and R ５ (Each of these independently represents a linear or branched alkyl group with 1 to 4 carbon atoms.) An organic bismuth compound represented by, Solvent and, A coating solution for film formation containing the following:

2. The coating solution for forming a film according to claim 1, wherein the bismuth element content in the organic bismuth compound is in the range of 1 to 60% by mass relative to the zinc element content in the organic zinc compound.

3. The coating solution for forming a film according to claim 1, wherein the organozinc compound is diethylzinc.

4. The coating solution for film formation according to claim 1, wherein the organic bismuth compound is trimethylbismuth.

5. The bismuth element content in the aforementioned organic bismuth compound is in the range of 1 to 60% by mass relative to the zinc element content in the aforementioned organic zinc compound. The aforementioned organozinc compound is diethylzinc, and The coating solution for forming a film according to claim 1, wherein the organic bismuth compound is trimethylbismuth.

6. A method for manufacturing an article having a substrate and a zinc oxide-containing coating, The manufacturing method, comprising forming the zinc oxide-containing film by a film-forming step which includes applying the coating solution for film formation described in any one of claims 1 to 5 onto the substrate.

7. The manufacturing method according to claim 6, wherein the coating is performed at a substrate temperature of 400°C or lower.

8. The manufacturing method according to claim 6, wherein the coating is performed in air.

9. The manufacturing method according to claim 6, wherein the coating is performed by a droplet coating method.

10. The manufacturing method according to claim 6, wherein the zinc oxide-containing coating having a film thickness of 300 nm or more and 1 μm or less is formed by the aforementioned film formation step.

11. The manufacturing method according to claim 6, wherein the zinc oxide-containing coating having a film thickness of 500 nm or more and 1 μm or less is formed by the aforementioned film formation step.

12. The aforementioned film formation process, The transmittance at a wavelength of 370 nm is 20.0% or less. The transmittance at a wavelength of 380 nm is 60.0% or less, The transmittance at a wavelength of 390 nm is 80.0% or less. The manufacturing method according to claim 6, which forms the zinc oxide-containing film having the transmittance characteristics.

13. The coating is performed in air at a substrate temperature of 400°C or less by droplet coating. The aforementioned film formation process, The film thickness is 300 nm or more and 1 μm or less. The transmittance at a wavelength of 370 nm is 20.0% or less. The transmittance at a wavelength of 380 nm is 60.0% or less, The transmittance at a wavelength of 390 nm is 80.0% or less. A zinc-containing coating having the transmittance characteristics is formed. The manufacturing method according to claim 6.

14. The manufacturing method according to claim 13, wherein the zinc oxide-containing coating having a film thickness of 500 nm or more and 1 μm or less is formed by the aforementioned film formation step.

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