Liquid composition for forming a water- and oil-repellent black film and method for producing the same

Abstract

To provide a liquid composition for forming a water- and oil-repellent black film, which can form a black film, having high water repellency, oil repellency, film strength and film adhesion.SOLUTION: A liquid composition for forming a water- and oil-repellent black film includes titanium oxynitride particles (C) with a specific surface area diameter of 10 nm-90 nm, combined with a fluorine-based functional group component (A) including a perfluoroether structure represented by formula (1) and a carboxylic acid compound (B), a silica sol gel (D), and a solvent (E). When the total nonvolatile content of the liquid composition is 100 mass%, the total content of the fluorine-based functional group component (A), the carboxylic acid compound (B), and the titanium oxynitride particles (C) is 40 mass%-80 mass%. The mass ratio of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) (A / C) is 0.01-0.50.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a liquid composition for forming a film having water repellency and oil repellency and being black, and a method for producing the same. More specifically, the present invention relates to a liquid composition for forming a water- and oil-repellent black film containing titanium oxynitride particles and a method for producing the same.

Background Art

[0002] Hitherto, as a liquid composition for forming a film having water repellency and oil repellency, the present applicant has proposed a liquid composition for forming a water- and oil-repellent film containing metal oxide particles bonded with a fluorine-containing functional group component containing a perfluoroether structure represented by the following general formula (1) or formula (2), silica sol-gel, and a solvent, and containing 1% by mass to 30% by mass of the fluorine-based functional group component when the liquid composition is 100% by mass (see Patent Document 1 (Claim 1, Claim 4, paragraph

[0024] , paragraph

[0083] , paragraph

[0087] , paragraph

[0100] )). This liquid composition is used for manufacturing an air filter.

[0003] In the method for producing this liquid composition for forming a water- and oil-repellent film, first, metal oxide particles and an organic solvent are mixed to prepare a dispersion of the metal oxide particles, and a fluorine-based compound containing the above fluorine-based functional group component is mixed into this dispersion, and further water and a catalyst are mixed to prepare a dispersion of fluorine-containing metal oxide particles. On the other hand, a silicon alkoxide, an alcohol, water, and, if necessary, an alkylene group component are mixed, and a catalyst is added to this mixture to prepare a silica sol-gel solution. Then, a solvent is mixed into this silica sol-gel solution, and this mixture and the dispersion of the fluorine-containing metal oxide particles are mixed to produce a liquid composition for forming a water- and oil-repellent film. The above metal oxide particles are oxide particles of one or two metals selected from the group consisting of Si, Al, Mg, Ca, Ti, Zn, and Zr, and examples thereof include SiO2, TiO2, ZrO2, etc.

[0004] There is disclosed a black ink containing a black pigment composed of black titanium oxynitride powder and having an OD value of 4.3 or more at a pigment concentration of 80% (see Patent Document 2 (Claims 3, 4, 6, paragraph

[0001] )). This black titanium oxynitride powder is produced by granulating titanium oxide powder using a polymer binder dissolved in water or an organic solvent, and subjecting the granulated powder to a reduction treatment by contacting it with high-temperature ammonia gas, with an oxygen content of 3 to 13%, a nitrogen content of 18 to 25%, a carbon content of 0.3 to 10.0%, the balance being Ti, and having a specific surface area of 25 m 2 / g or more, a blackness degree (L value) of 8.5 or more, and a specific gravity of 4.2 or less.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Although the black ink disclosed in Patent Document 2 has high blackness and light-shielding properties due to the black titanium oxynitride powder contained as a black pigment and is excellent as a black matrix material, when it is applied to the surfaces of interior products that require designability or to enhance the aesthetics of vehicle interior members, the coated black film has poor stain prevention performance and improvement has been demanded.

[0007] Therefore, in order to obtain a liquid composition having a property that the formed film is black and has water repellency and oil repellency, it is conceivable to use the black titanium oxynitride powder shown in Patent Document 2, that is, titanium oxynitride particles, as the metal oxide particles shown in Patent Document 1.

[0008] However, in order to prepare a dispersion of titanium oxynitride particles, even if titanium oxynitride particles and an organic solvent are mixed or titanium oxynitride particles and water are mixed according to the production methods of Patent Document 1 or 2, since it is a nitride containing an oxide rather than a single oxide, there has been a problem that titanium oxynitride particles are difficult to disperse in an organic solvent or water.

[0009] An object of the present invention is to provide a liquid composition for forming a water- and oil-repellent black film in which the formed film is black and has high water repellency, oil repellency, film strength, and film adhesion, and a method for producing the same.

Means for Solving the Problems

[0010] The present inventor has found that when a carboxylic acid compound is used as a dispersant and an aqueous solution of titanium oxynitride particles and the carboxylic acid compound is mixed, a small amount of the carboxylic acid compound uniformly disperses the titanium oxynitride particles in this aqueous solution, and then, even if this dispersion and a silica sol-gel solution are mixed, since this dispersion is close to neutral, the titanium oxynitride particles do not aggregate, and thus the present invention has been achieved.

[0011] A first aspect of the present invention includes a fluorine-based functional group component (A) containing a perfluoroether structure represented by the following general formula (1) or formula (2), a carboxylic acid compound (B), and titanium oxynitride particles (C) having a specific surface area diameter of 10 nm to 90 nm to which the fluorine-based functional group component (A) and the carboxylic acid compound (B) are bonded, a silica sol-gel (D), and a solvent (E). When the total amount of the non-volatile components of the liquid composition is 100% by mass, the total content ratio of the fluorine-based functional group component (A), the carboxylic acid compound (B), and the titanium oxynitride particles (C) is 40% by mass to 80% by mass, and the mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) is in the range of 0.01 to 0.50. It is a liquid composition for forming a water- and oil-repellent black film.

[0012]

Chemical formula

[0013] In the above formulas (1) and (2), p, q, and r are each an integer of 1 to 6, which may be the same or different from each other, and the carbon skeleton may be linear or branched. Further, in the above formulas (1) and (2), X is a hydrocarbon group having 2 to 10 carbon atoms, and may contain one or more bonds selected from an ether bond, a CO-NH bond, an O-CO-NH bond, and a sulfonamide bond. Furthermore, in the above formulas (1) and (2), Y is a hydrolyzate of silane or the main component of silica sol-gel.

[0014] Regarding this Y in more detail, Y is a site that binds to the titanium oxynitride particles (C). As a specific example, in the formula (3) or (4) described later, a structure in which the Z moiety is hydrolyzed can be mentioned as Y. In addition, as Y, the main component of silica sol-gel obtained by mixing a silane compound of the formula (3) or (4) with a silicon alkoxide such as tetraethoxysilane or tetramethoxysilane and subjecting them to hydrolysis polymerization can also be mentioned. Furthermore, as Y, the main component of silica sol-gel obtained by mixing a silane compound of the formula (3) or (4) with a silicon alkoxide such as tetraethoxysilane or tetramethoxysilane and a silane containing an epoxy group, a vinyl group, or an ether group and subjecting them to hydrolysis polymerization can also be mentioned.

[0015] The second aspect of the present invention is an invention based on the first aspect, and is a liquid composition for forming a water- and oil-repellent black film, wherein when a coating film is formed under the condition of a film thickness of 1.0 μm, the maximum light transmittance in the wavelength range of 380 nm to 780 nm of this coating film is 25% or less. Here, the wavelength range is set to 380 nm to 780 nm in order to evaluate in the wavelength region visible to the human eye, that is, the visible light region. The maximum light transmittance is set to 25% or less because if it exceeds 25%, the coating film to be evaluated is inferior in light-shielding property as a decorative coating film and cannot be concealed by the film.

[0016] The third aspect of the present invention is an invention based on the first or second aspect, and is a liquid composition for forming a water- and oil-repellent black film, wherein the solvent (E) is a mixed solvent of water and an alcohol having 1 to 4 carbon atoms, or a mixed solvent of water, an alcohol having 1 to 4 carbon atoms, and an organic solvent other than the alcohol having 1 to 4 carbon atoms.

[0017] A fourth aspect of the present invention is a method for producing a liquid composition for forming a water- and oil-repellent black film by mixing an aqueous dispersion of fluorine-containing titanium oxynitride particles, a silica sol-gel solution, and a solvent as shown in FIG. 1.

[0018] A fifth aspect of the present invention is an invention based on the fourth aspect, and is a liquid composition for forming a water- and oil-repellent black film, wherein the aqueous dispersion of the fluorine-containing titanium oxynitride particles is prepared by adding and mixing a fluorine-based compound to an aqueous dispersion of titanium oxynitride particles.

[0019] A sixth aspect of the present invention is an invention based on the fourth aspect, and is a method for producing a liquid composition for forming a water- and oil-repellent black film, wherein the silica sol-gel solution is prepared by adding and mixing a catalyst to a mixed solution of silicon alkoxide, alcohol, and water as shown in FIG. 1.

Advantages of the Invention

[0020] The liquid composition for forming a water- and oil-repellent black film according to the first aspect of the present invention (hereinafter, sometimes simply referred to as the liquid composition) includes a fluorine-based functional group component (A) containing a perfluoroether structure represented by the above-described formula (1) or formula (2), a carboxylic acid compound (B), and titanium oxynitride particles (C) having a specific surface area diameter of 10 nm to 90 nm to which the carboxylic acid compound (B) is bonded, a silica sol-gel (D), and a solvent (E). When the total amount of the non-volatile components of the liquid composition is 100% by mass, the total content ratio of the fluorine-based functional group component (A), the carboxylic acid compound (B), and the titanium oxynitride particles (C) is 40% by mass to 80% by mass, and the mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) is in the range of 0.01 to 0.50. Since this liquid composition contains titanium oxynitride particles (C) to which the fluorine-based functional group component (A) and the carboxylic acid compound are bonded when formed into a film, the formed film is black and has high water repellency and oil repellency. Also, when formed into a film, titanium oxynitride particles (C) having a specific surface area diameter of 10 nm to 90 nm are bonded to each other by the silica sol-gel (D) in the film, so that the strength and adhesion of the film can be improved. Since the surface of the formed film is not smooth, fingerprints are less noticeable on the film surface after fingerprints are attached to the film surface.

[0021] In the liquid composition according to the second aspect of the present invention, when a coating film is formed under the condition of a film thickness of 1.0 μm, the maximum light transmittance in the wavelength range of 380 nm to 780 nm is 25% or less, so that a desired blackness can be obtained.

[0022] In the liquid composition according to the third aspect of the present invention, the solvent is preferably an alcohol such as methanol, ethanol, isopropanol, or 1-butanol having 1 to 4 carbon atoms and a boiling point of less than 120°C. Since the evaporation rate during drying can be controlled, the appearance of the film can be favorably formed.

[0023] In the method for producing the liquid composition according to the fourth aspect of the present invention, as shown in FIG. 1, fluorine-containing A water dispersion of titanium oxynitride particles, a silica sol-gel solution, and a solvent are mixed to produce a liquid composition for forming a water- and oil-repellent black film. As a result, titanium oxynitride particles with water- and oil-repellent surfaces are present in the silica sol-gel. When the liquid composition is formed into a film, the film becomes black and retains water- and oil-repellency.

[0024] In the method for producing the liquid composition according to the fifth aspect of the present invention, since a fluorine-based compound is added to and mixed with the water dispersion of titanium oxynitride particles, a water dispersion in which fluorine-containing titanium oxynitride particles are uniformly dispersed can be obtained.

[0025] In the method for producing the liquid composition according to the sixth aspect of the present invention, the silica sol-gel solution prepared by adding and mixing a catalyst to a mixed solution of silicon alkoxide, alcohol, and water acts as a binder for the fluorine-containing titanium oxynitride particles.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0027] Next, embodiments for carrying out the present invention will be described with reference to the drawings.

[0028] 〔Method for Producing Liquid Composition for Forming Water- and Oil-Repellent Black Film〕 The liquid composition for forming a water- and oil-repellent black film is roughly produced by the following method. As shown in Fig. 1, an aqueous solution 12 of a carboxylic acid compound is mixed with titanium oxynitride particles 11 to prepare an aqueous dispersion 13 of titanium oxynitride particles. An aqueous dispersion 15 of fluorine-containing titanium oxynitride particles is prepared by mixing a fluorine-based compound 14 containing a fluorine-based functional group component (A) with this aqueous dispersion 13. On the other hand, a silicon alkoxide 21, an alcohol 22, and water 23 are mixed, and a catalyst 24 is added and mixed to this mixture to prepare a silica sol-gel solution 25. A liquid composition 30 for forming a water- and oil-repellent black film is produced by mixing the aqueous dispersion 15 of fluorine-containing titanium oxynitride particles with a diluted solution 27 obtained by mixing a solvent 26 with this silica sol-gel solution 25. Details are described below for each step.

[0029] 〔Preparation of Aqueous Dispersion of Titanium Oxynitride Particles〕 First, titanium oxynitride (TiON) particles are dispersed in an aqueous solution of a carboxylic acid compound to prepare an aqueous dispersion of titanium oxynitride particles. The titanium oxynitride particles have a specific surface area diameter of 10 nm to 90 nm, preferably 12 nm to 70 nm. When the specific surface area diameter is less than 10 nm, aggregation of the titanium oxynitride particles easily occurs and it becomes difficult to disperse them in the medium. When it exceeds 90 nm, when the liquid composition is formed into a film, the titanium oxynitride particles fall off from the water- and oil-repellent film. In this specification, the specific surface area diameter of the titanium oxynitride particles is calculated from the following formula (A) when the specific surface area measured by the BET method is S and the density of the titanium oxynitride particles is ρ. Specific surface area diameter = 6 / ρS (A)

[0030] The carboxylic acid compound of this embodiment is a monocarboxylic acid, dicarboxylic acid, or tricarboxylic acid. Examples of the monocarboxylic acid include formic acid, lactic acid, gluconic acid, etc. Examples of the dicarboxylic acid include fumaric acid, tartaric acid, maleic acid, malic acid, etc. Examples of the tricarboxylic acid include citric acid, aconitic acid, etc. In this embodiment, ammonium salts, sodium salts, and potassium salts of these acids are also used. Specifically, examples thereof include diammonium hydrogen citrate, potassium sodium tartrate, sodium gluconate, etc. When an aqueous solution of titanium oxynitride particles and a carboxylic acid compound is mixed, even if the amount of the carboxylic acid compound is small, it acts as a dispersant, and the titanium oxynitride particles are uniformly dispersed in this aqueous solution.

[0031] 〔Preparation of aqueous dispersion of fluorine-containing titanium oxynitride particles〕 Next, a fluorine-based compound containing a fluorine-based functional group component represented by the above formula (1) or formula (2) is added to the prepared aqueous dispersion of titanium oxynitride particles to synthesize a composite material in which titanium oxynitride particles, a fluorine-based functional group component, and a carboxylic acid compound are nanocomposited. Thereby, an aqueous dispersion of fluorine-containing titanium oxynitride particles is prepared. The carboxylic acid compound binds to the titanium oxynitride particles in a state where the hydrogen of each COOH group of the monocarboxylic acid, dicarboxylic acid, or tricarboxylic acid is removed.

[0032] The fluorine-based compound containing a fluorine-based functional group component is represented by the following general formula (3) or formula (4). More specifically, examples of the perfluoroether group in these formula (3) or formula (4) include perfluoroether structures represented by the following formula (5) to (13).

[0033]

Chemical formula

[0034]

Chemical formula

[0035]

Chemical formula

[0036] In addition, examples of X in the above formulas (3) and (4) include structures represented by the following formulas (14) to (18). Note that the following formula (14) represents an ether bond, the following formula (15) represents an ester bond, the following formula (16) represents an amide bond, the following formula (17) represents a urethane bond, and the following formula (18) represents an example including a sulfonamide bond.

[0037]

Chemical formula

[0038] Here, in the above formulas (14) to (18), R 2 and R 3 are hydrocarbon groups having 0 to 10 carbon atoms, and R 4 is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon groups of R 2 and R 3 include alkylene groups such as a methylene group and an ethylene group, and examples of the hydrocarbon group of R 4 include alkyl groups such as a methyl group and an ethyl group, as well as a phenyl group and the like.

[0039] In addition, in the above formulas (3) and (4), examples of R 1 include a methyl group, an ethyl group, and the like.

[0040] In addition, in the above formulas (3) and (4), Z is not particularly limited as long as it is a hydrolyzable group that can be hydrolyzed to form a Si-O-Si bond. Specific examples of such a hydrolyzable group include alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group, aryloxy groups such as a phenoxy group and a naphthoxy group, aralkyloxy groups such as a benzyloxy group and a phenethyloxy group, and acyloxy groups such as an acetoxy group, a propionyloxy group, a butyryloxy group, a valeryloxy group, a pivaloyloxy group, and a benzoyloxy group. Among these, it is preferable to apply an ethoxy group.

[0041] Here, specific examples of the fluorine-based compound containing a fluorine-based functional group component having a perfluoroether structure represented by the above formula (3) or formula (4) include, for example, structures represented by the following formulas (19) to (27). In the following formulas (19) to (27), R is a methyl group or an ethyl group.

[0042]

Chemical formula

[0043]

Chemical formula

[0044] As described above, the fluorine-based compound contained in the liquid composition for forming a water- and oil-repellent black film of the present embodiment has a perfluoroether group in which a short-chain perfluoroalkyl group having 6 or less carbon atoms and a perfluoroalkylene group are bonded to an oxygen atom in the molecule, and since the fluorine content in the molecule is high, excellent water- and oil-repellency can be imparted to the formed film.

[0045] 〔Preparation of silica sol-gel solution〕 First, a mixed solution is prepared by mixing tetramethoxysilane or tetraethoxysilane as a silicon alkoxide, an alcohol having 1 to 4 carbon atoms and a boiling point of less than 120°C, and water. Specific examples of this silicon alkoxide include tetramethoxysilane, its oligomer, tetraethoxysilane, and its oligomer. For example, for the purpose of obtaining a water- and oil-repellent film with high durability, it is preferable to use tetramethoxysilane. On the other hand, when avoiding methanol generated during hydrolysis, it is preferable to use tetraethoxysilane.

[0046] Examples of the alcohol having 1 to 4 carbon atoms and a boiling point of less than 120°C include alcohols such as methanol, ethanol, isopropanol, and 1-butanol. Particularly, methanol or ethanol is preferred. This is because these alcohols are easily mixed with silicon alkoxide. As the above water, in order to prevent contamination of impurities, it is desirable to use ion-exchanged water, pure water, etc. Alcohol having 1 to 4 carbon atoms and water are added to the silicon alkoxide, and the mixture is preferably stirred at a temperature of 10°C to 30°C for 5 to 20 minutes to prepare a mixed solution.

[0047] A catalyst is added to and mixed with the above-prepared mixed solution. Examples of this catalyst include organic acids, inorganic acids, or titanium compounds. At this time, the liquid temperature is preferably maintained at a temperature of 30°C to 80°C, and preferably stirred for 1 to 24 hours. Thereby, a silica sol-gel solution is prepared. For the next step, a solvent is added to and mixed with the silica sol-gel solution to make a diluted solution. Examples of the solvent include a mixed solvent of water and an alcohol having 1 to 4 carbon atoms, or a mixed solvent of water and an alcohol having 1 to 4 carbon atoms and an organic solvent other than the alcohol having 1 to 4 carbon atoms.

[0048] The silica sol-gel solution to which the above solvent is added and mixed preferably contains silicon alkoxide in a proportion of 2% to 50% by mass, alcohol having 1 to 4 carbon atoms in a proportion of 20% to 98% by mass, water in a proportion of 0.1% to 40% by mass, and 0.01% to 5% by mass as a catalyst.

[0049] The reason for limiting the proportion of alcohol in the range of carbon numbers 1 to 4 to the above range is that if the proportion of alcohol is less than the lower limit value, silicon alkoxide will not dissolve in the solution and will separate. During the hydrolysis reaction of silicon alkoxide, the reaction solution is likely to gel. On the other hand, if it exceeds the upper limit value, the amount of water and catalyst required for hydrolysis will be relatively small, resulting in a decrease in the reactivity of hydrolysis, polymerization not proceeding, and the adhesion of the film being likely to decrease. The reason for limiting the proportion of water to the above range is that if it is less than the lower limit value, the hydrolysis rate is likely to be slow, polymerization does not proceed, and the adhesion of the water- and oil-repellent film is likely to be insufficient. On the other hand, if it exceeds the upper limit value, the reaction solution gels during the hydrolysis reaction, and because there is too much water, the silicon alkoxide compound is unlikely to dissolve in the aqueous alcohol solution and separation is likely to occur.

[0050] The SiO2 concentration (SiO2 content) in the silica sol-gel is preferably 1 mass% to 40 mass%. If this SiO2 concentration is less than the lower limit value, polymerization is insufficient, and the adhesion of the film is likely to decrease and cracks are likely to occur. If it exceeds the upper limit value, the proportion of water is relatively high and silicon alkoxide does not dissolve, resulting in the problem that the reaction solution gels.

[0051] Organic acids, inorganic acids, or titanium compounds function as catalysts for promoting the hydrolysis reaction. Examples of organic acids include formic acid and oxalic acid. Examples of inorganic acids include hydrochloric acid, nitric acid, and phosphoric acid. Examples of titanium compounds include tetrapropoxytitanium, tetrabutoxytitanium, tetraisopropoxytitanium, and titanium lactate. The catalyst is not limited to the above. The reason for limiting the proportion of the above catalyst to the above range is that if it is less than the lower limit value, the reactivity is poor and polymerization is likely to be insufficient, and it is difficult to form a film. On the other hand, even if it exceeds the upper limit value, there is no effect on the reactivity, but problems such as corrosion of the fibers of the non-woven fabric due to the residual acid are likely to occur.

[0052] A liquid composition for forming a water- and oil-repellent black film is produced by mixing an aqueous dispersion of fluorine-containing titanium oxynitride particles with a diluent prepared by adding and mixing a solvent to the above-described silica sol-gel solution.

[0053] [Liquid Composition for Forming Water- and Oil-Repellent Black Film] The liquid composition for forming a water- and oil-repellent black film of this embodiment is produced by the above production method and contains titanium oxynitride particles (C) to which the above-described fluorine-based functional group component (A) and carboxylic acid compound (B) are bonded, silica sol-gel (D), and a solvent (E). This fluorine-based functional group component (A) has a perfluoroether structure represented by the above general formula (1) or formula (2), and when the total amount of the non-volatile content of the liquid composition is 100% by mass, it is contained in the liquid composition in an amount of 1% to 15% by mass. If the fluorine-based functional group component is less than 1% by mass, oil repellency cannot be imparted to the formed film, and if it exceeds 15% by mass, film peeling and the like occur and the film-forming property is poor. The preferable content ratio of the fluorine-based functional group component is 1.5% to 12% by mass.

[0054] Also, the silica sol-gel (D) is contained in the liquid composition in an amount of 20% to 95% by mass when the total amount of the non-volatile content of the liquid composition is 100% by mass. If the silica sol-gel is less than 20% by mass, the adhesion and strength of the formed film to the substrate are poor, and if it exceeds 95% by mass, oil repellency cannot be imparted to the film. Further, the total content ratio of the fluorine-based functional group component (A), carboxylic acid compound (B), and titanium oxynitride particles (C) is 40% to 80% by mass, preferably 50% to 70% by mass, in the liquid composition when the total amount of the non-volatile content of the liquid composition is 100% by mass. Further, the mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) is in the range of 0.01 to 0.50, preferably 0.02 to 0.40.

[0055] When the total amount of the non-volatile components of the liquid composition is 100% by mass, if the total of component (A), compound (B), and particles (C) is less than 40% by mass, the water and oil repellency performance of the water and oil repellent film and the blackness of the film decrease. Also, if the total exceeds 80% by mass, the content of silica sol-gel (D) becomes relatively low, and when the liquid composition is formed into a film on a substrate, the water and oil repellent film does not firmly adhere to the substrate surface. Further, when the mass ratio (A / C) is less than 0.01, the water and oil repellent film is inferior in water and oil repellency, and when it exceeds 0.50, the adhesion of the water and oil repellent film to the substrate surface decreases. As described above, the solvent (E) is a mixed solvent of water and an alcohol having 1 to 4 carbon atoms, or a mixed solvent of water, an alcohol having 1 to 4 carbon atoms, and an organic solvent other than the alcohol having 1 to 4 carbon atoms. For example, it is water in which the content ratio of water or ethanol is 40% by mass or less. The reason for setting the content ratio of ethanol to 40% by mass or less is for handling safety. Also, by using a mixed solvent of water and ethanol, the drying speed is improved and the film-forming property is improved.

[0056] Specific examples of the perfluoroether structure include the structures represented by the above-described formulas (19) to (27).

[0057] Since the liquid composition of the present embodiment contains silica sol-gel as a main component, when formed into a film on the substrate surface, a water and oil repellent film with excellent adhesion to the substrate surface and high strength that is difficult to peel off can be obtained. Also, since the liquid composition contains a fluorine-based functional group component having a perfluoroether structure represented by the above general formula (1) or formula (2), the formed film has water repellency and oil repellency effects. Furthermore, since it contains titanium oxynitride particles, the formed film becomes black.

[0058] 〔Method for forming a water and oil repellent film on a substrate surface〕 To form the water- and oil-repellent film of the present embodiment on the surface of a substrate, a liquid composition for forming a water- and oil-repellent black film is applied onto the substrate and then dried at room temperature in the atmosphere to cure the liquid composition. The substrate is not particularly limited, and examples thereof include metal plates such as stainless steel (SUS), aluminum, and iron, glass such as window glass and mirrors, tiles, plastics such as polyvinyl chloride (PVC), and polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of the coating method of the liquid composition include a screen printing method, a bar coating method, a die coating method, a doctor blade, a spin method, a brush coating method, and the like.

[0059] As shown in Fig. 2, the water- and oil-repellent black film 2 formed on the surface of the substrate 1 is composed of a large number of fluorine-containing titanium oxynitride particles 3 whose particle surfaces are covered with a fluorine-based functional group component, bound by silica sol-gel 4 as a binder. Since the water- and oil-repellent black film 2 contains fluorine-containing titanium oxynitride particles 3 to which a fluorine-based functional group component is bonded, the oil-repellent performance of the film is maintained. In addition, since the fluorine-containing titanium oxynitride particles 3 having a specific surface area diameter of 10 nm to 90 nm are bonded to each other in the film 2 by the silica sol-gel 4, the strength and the adhesion of the film 2 can be improved. Further, due to the presence of the fluorine-containing titanium oxynitride particles 3, the film becomes black and the film surface becomes uneven, and after fingerprints are attached to the surface of the film 2, there is an advantage that the fingerprints are less noticeable on the film surface. The film thickness and the blackness degree of the film can be controlled by changing the particle diameter of the titanium oxynitride particles and the content ratio of the titanium oxynitride particles in the film component.

Examples

[0060] Next, the examples of the present invention will be described in detail together with comparative examples. First, Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 4 for preparing an aqueous dispersion of fluorine-containing titanium oxynitride particles will be described, and then Examples 1 to 5 and Comparative Examples 1 to 6 regarding the production of a liquid composition for forming a water- and oil-repellent black film using these synthesis examples and comparative synthesis examples will be described.

[0061] [Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 4 for Preparing Aqueous Dispersions of Fluorine-Containing Titanium Oxynitride Particles] <Synthesis Example 1> Titanium oxynitride particles with a specific surface area diameter of 12 nm obtained by reducing titanium oxide powder with ammonia gas were mixed with water in which diammonium hydrogen citrate as a carboxylic acid compound was dissolved, and the mixture was mixed using a bead mill apparatus (manufactured by Asada Iron Works Co., Ltd., model: Picomill PCM-LR) to prepare an aqueous dispersion of titanium oxynitride particles with a concentration of 30% by mass. The ratio of the carboxylic acid compound to the titanium oxynitride particles was 1% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 7.50 g of the fluorine-based compound represented by the above formula (19) was added thereto and mixed, and the mixture was stirred at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and citric acid were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.50.

[0062] <Synthesis Example 2> Titanium oxynitride particles with a specific surface area diameter of 25 nm were mixed with water in which fumaric acid as a carboxylic acid compound was dissolved, and in the same manner as in Synthesis Example 1, an aqueous dispersion of titanium oxynitride particles (concentration: 30% by mass) was prepared. The ratio of the carboxylic acid compound to the titanium oxynitride particles was 1% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 0.75 g of the fluorine-based compound represented by the above formula (20) was added thereto and mixed, and the mixture was stirred at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and fumaric acid were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.05.

[0063] <Synthesis Example 3> Titanium oxynitride particles with a specific surface area diameter of 90 nm were mixed with water in which tartaric acid as a carboxylic acid compound was dissolved, and in the same manner as in Synthesis Example 1, an aqueous dispersion of titanium oxynitride particles (concentration: 30% by mass) was prepared. The ratio of the carboxylic acid compound to the titanium oxynitride particles was 1% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 0.23 g of the fluorine-based compound represented by the above formula (21) was added thereto and mixed, followed by stirring at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and tartaric acid were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.015.

[0064] <Synthesis Example 4> Titanium oxynitride particles with a specific surface area diameter of 25 nm were mixed with water in which maleic acid as a carboxylic acid compound was dissolved, and in the same manner as in Synthesis Example 1, an aqueous dispersion of titanium oxynitride particles (concentration: 30% by mass) was prepared. The ratio of the carboxylic acid compound to the titanium oxynitride particles was 1% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 2.70 g of the fluorine-based compound represented by the above formula (22) was added thereto and mixed, followed by stirring at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and maleic acid were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.18.

[0065] <Synthesis Example 5> Titanium oxynitride particles with a specific surface area diameter of 25 nm were mixed with water in which gluconic acid as a carboxylic acid compound was dissolved, and in the same manner as in Synthesis Example 1, an aqueous dispersion of titanium oxynitride particles (concentration: 30% by mass) was prepared. The ratio of the carboxylic acid compound to the titanium oxynitride particles was 1% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 1.50 g of the fluorine-based compound represented by the above formula (27) was added thereto and mixed, followed by stirring at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and gluconic acid were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.10.

[0066] <Comparative Synthesis Example 1> Titanium oxynitride particles with a specific surface area diameter of 25 nm were mixed with water in which diammonium hydrogen citrate as a carboxylic acid compound was dissolved, and in the same manner as in Synthesis Example 1, an aqueous dispersion of titanium oxynitride particles (concentration: 30% by mass) was prepared. The ratio of the carboxylic acid compound to the titanium oxynitride particles was 1% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 0.075 g of the fluorine-based compound represented by the above formula (27) was added thereto and mixed, followed by stirring at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and citric acid were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.005.

[0067] <Comparative Synthesis Example 2> Titanium oxynitride particles with a specific surface area diameter of 25 nm were mixed with water in which diammonium hydrogen citrate as a carboxylic acid compound was dissolved, and in the same manner as in Synthesis Example 1, an aqueous dispersion of titanium oxynitride particles (concentration: 30% by mass) was prepared. The ratio of the carboxylic acid compound to the titanium oxynitride particles was 1% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 9.00 g of the fluorine-based compound represented by the above formula (27) was added thereto and mixed, followed by stirring at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and citric acid were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.60.

[0068] <Comparative Synthesis Example 3> Titanium oxynitride particles with a specific surface area diameter of 120 nm were mixed with water in which diammonium hydrogen citrate as a carboxylic acid compound was dissolved, and in the same manner as in Synthesis Example 1, an aqueous dispersion of titanium oxynitride particles (concentration: 30% by mass) was prepared. The ratio of the carboxylic acid compound to the titanium oxynitride particles was 1% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 2.25 g of the fluorine-based compound represented by the above formula (27) was added thereto and mixed, followed by stirring at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and citric acid were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.15.

[0069] <Comparative Synthesis Example 4> Solsperse 20000 (manufactured by Lubrizol Japan Co., Ltd.) was used as a polymer dispersant other than the carboxylic acid compound. This polymer dispersant, water, industrial alcohol (AP-7, manufactured by Nippon Alcohol Industry Co., Ltd.), and titanium oxynitride particles with a specific surface area diameter of 25 nm were mixed, and in the same manner as in Synthesis Example 1, an aqueous dispersion of titanium oxynitride particles (concentration: 30% by mass) was prepared. The ratio of Solsperse 20000 to the titanium oxynitride particles was 10% by mass. 50 g of the obtained aqueous dispersion of titanium oxynitride particles was placed in a beaker, and 2.25 g of the fluorine-based compound represented by the above formula (27) was added thereto and mixed, followed by stirring at 40 °C for 2 hours to obtain an aqueous dispersion of fluorine-containing titanium oxynitride particles in which the fluorine-based compound and the polymer dispersant were bonded to the titanium oxynitride particles. The mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was 0.15.

[0070] Table 1 below shows the details of the aqueous dispersions of the fluorine-containing titanium oxynitride particles of Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 4. In Table 1, R in the formulas of the fluorine-containing silanes represented by formulas (19) to (22) and formula (27) as the fluorine-based compound is all an ethyl group.

[0071]

Table 1

[0072] [Examples 1 to 5 and Comparative Examples 1 to 6 for the Production of a Liquid Composition for Forming a Water- and Oil-Repellent Black Film] [Example 1] 14.7 g of a trimer to pentamer of tetramethoxysilane (TMOS) (manufactured by Mitsubishi Chemical Corporation, trade name: MKC Silicate MS51) as a silicon alkoxide and 29.4 g of ethanol (EtOH) (boiling point 78.3 °C) as an organic solvent were mixed, and further 5.6 g of ion-exchanged water was added, and the mixture was stirred in a separable flask at a temperature of 25 °C for 5 minutes to prepare a mixed solution. Further, 0.2 g of tetraisopropoxytitanium was added to this mixed solution and stirred at 40 °C for 2 hours to obtain a silica sol-gel solution. To 5.0 g of the obtained silica sol-gel solution, 8.2 g of water and 2.0 g of industrial alcohol (AP-7, manufactured by Nippon Alcohol Industry Co., Ltd.) were added and mixed to prepare a diluted solution. To this diluted solution, 1.51 g of an aqueous dispersion of fluorine-containing titanium oxynitride particles obtained in Synthesis Example 1 was added and mixed to obtain a liquid composition for forming a water- and oil-repellent black film. The details are shown in Table 2 below.

[0073] In Table 2, the "content ratio in the liquid composition excluding the solvent" means the content ratio of the non-volatile matter or solid content in the liquid composition. The content ratios of "(A)", "(D)", and "(A)+(B)+(C)" are shown.

[0074] [Table 2]

[0075] [Examples 2 to 5 and Comparative Examples 1 to 6] As shown in Table 2, in Examples 2 to 5, the aqueous dispersions of fluorine-containing titanium oxynitride particles obtained in Synthesis Examples 2 to 5 shown in Table 1 were used respectively, and their respective weights were determined. In Comparative Examples 1 to 6, the aqueous dispersions of fluorine-containing titanium oxynitride particles obtained in Synthesis Examples 1, 3 and Comparative Synthesis Examples 1 to 4 shown in Table 1 were used respectively, and their respective weights were determined. In this way, the liquid compositions for forming a water- and oil-repellent black film of Examples 2 to 5 and Comparative Examples 1 to 6 were prepared.

[0076] [Comparative Tests and Evaluations] The 11 types of liquid compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were each applied onto a glass substrate with a thickness of 1.1 mm, a length of 100 mm, and a width of 100 mm using a brush (nylon brush Meister manufactured by Matsumatsu Brush Co., Ltd.) so that the dried thickness became 1.0 μm, and 11 types of coating films were formed. All the coating films were left standing in an atmospheric environment at room temperature for 3 hours to dry the coating films and obtain 11 types of films on the above glass substrate. For these films, the water wettability (water repellency), oil repellency of the film surface, and the appearance of the film were evaluated, and a cellophane tape (registered trademark) peeling test of the film (hereinafter referred to as an adhesion test) was conducted. In addition, the light transmittance of the coating film was evaluated. These results are shown in Table 3 below.

[0077] (1) Water repellency (contact angle) of the film surface Using a Drop Master DM-700 manufactured by Kyowa Interface Science Co., Ltd., ion-exchanged water at 22°C ± 1°C was prepared in a syringe, and the tip of the syringe needle was made to eject a 2 μL droplet. Next, the film on the glass substrate to be evaluated was brought close to this droplet to attach the droplet to the film. The contact angle of the attached water was measured. The value analyzed by the θ / 2 method for the contact angle 1 second after the water touched the film surface in a stationary state was taken as the contact angle of water, and the water wettability (water repellency) of the film surface was evaluated. A water contact angle of 90 degrees or more was regarded as having 'good' water repellency, and less than 90 degrees was regarded as having 'poor' water repellency.

[0078] (2) Oil repellency (contact angle) of the film surface Using a Drop Master DM-700 manufactured by Kyowa Interface Science Co., Ltd., n-hexadecane (hereinafter referred to as oil) at 22°C ± 1°C was prepared in a syringe, and the tip of the syringe needle was made to eject a 2 μL droplet. Next, the film on the glass substrate to be evaluated was brought close to this droplet to attach the droplet to the film. The contact angle of the attached oil was measured. The value analyzed by the θ / 2 method for the contact angle 1 second after the oil touched the film surface in a stationary state was taken as the contact angle of oil, and the oil repellency of the film surface was evaluated. An oil contact angle of 50 degrees or more was regarded as having 'good' oil repellency, and less than 50 degrees was regarded as having 'poor' oil repellency.

[0079] (3) Appearance of the film The film on the glass substrate to be evaluated was visually observed to examine whether the film was transparent and whether particles were aggregated in the film. Films that were transparent were rated as "somewhat good" or "good" according to the degree, and films with aggregated particles in the film were rated as "poor".

[0080] (4) Adhesion test of the film A 1-mm-wide cross-cut was made in a grid pattern on the film on the glass substrate to be evaluated, and an adhesive tape (manufactured by Nichiban Co., Ltd., trade name "Cellotape (registered trademark)") was applied to the film cross-cut in the grid pattern. A Cellotape (registered trademark) peel test (adhesion test) was conducted in accordance with the grid tape method of JIS K5600-5-6 (cross-cut method). The number of 100 grid squares with cross-cuts was used as the denominator, and the number of grid squares remaining on the substrate after the peel test was used as the numerator. A case of 100 / 100 was rated as "pass", and a case with peeling was rated as "fail".

[0081] (5) Light transmittance evaluation test of the film Regarding the coating film on the glass substrate to be evaluated, after measuring the baseline with the substrate on which the coating film was formed using a spectrophotometer (U-4150 manufactured by Hitachi High-Technologies Corporation), the light transmittance in the visible light region with wavelengths from 380 nm to 780 nm was measured, and the maximum light transmittance (%) was determined.

[0082]

Table 3

[0083] As is clear from Table 3, in Comparative Example 1, since the ratio of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was too low at 0.005, the appearance of the film was good and the peel test of the film passed. However, the contact angles of water and n-hexadecane were poor, and the water and oil repellency performance of the film was inferior. The maximum light transmittance of the coating film in the wavelength range of 380 nm to 780 nm was extremely low at 18.5%, and a black film was obtained.

[0084] In Comparative Example 2, since the ratio of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) was too high at 0.60, the particles in the film aggregated, resulting in poor appearance of the film. Also, the tape (registered trademark) peel test of the film failed, the contact angles of water and n-hexadecane were poor, and the water and oil repellency performance of the film was inferior. The maximum light transmittance of the coating film in the wavelength range of 380 nm to 780 nm was as low as 23.2%, and a black film was obtained.

[0085] In Comparative Example 3, since the specific surface area diameter of the titanium oxynitride particles was too large at 120 nm, the appearance of the film was good, but the peel test of the film failed. Also, the contact angles of water and n-hexadecane were poor, and the water and oil repellency performance of the film was inferior. The maximum light transmittance of the coating film in the wavelength range of 380 nm to 780 nm was as high as 27.5%, and a black film could not be obtained. This was considered to be because the specific surface area diameter of the titanium oxynitride particles was too large, resulting in low hiding power of the film.

[0086] In Comparative Example 4, since a polymer dispersant other than the carboxylic acid compound (Solsperse 20000) was used as the dispersant for the titanium oxynitride particles, aggregation of the particles occurred when the aqueous dispersion of the fluorine-containing titanium oxynitride particles was mixed with the diluted silica sol-gel solution, and a film could not be formed. Therefore, the contact angles of water and n-hexadecane, the appearance of the film, the peel test of the film, and the evaluation of the maximum light transmittance of the film could not be performed.

[0087] In Comparative Example 5, since the total content ratio of the fluorine-based functional group component (A), the carboxylic acid compound (B), and the titanium oxynitride particles (C) was too low at 35% by mass and the content ratio of the silica sol-gel (D) increased relatively, the liquid composition became agar-like and a film could not be formed. Therefore, the contact angles of water and n-hexadecane, the appearance of the film, the peel test of the film, and the evaluation of the maximum light transmittance of the film could not be performed.

[0088] In Comparative Example 6, the total content ratio of the fluorine-based functional group component (A), the carboxylic acid compound (B), and the titanium oxynitride particles (C) was too high at 82% by mass, and the content ratio of the silica sol-gel (D) relatively decreased. As a result, the maximum light transmittance of the film was 19.1%, and a black film was obtained. However, the contact angles of water and n-hexadecane were poor, and the water and oil repellency performance of the film was inferior. Also, the appearance of the film was poor, and the film peeling test was unqualified.

[0089] On the other hand, in Examples 1 to 5, the specific surface area diameter of the titanium oxynitride particles was in the range of 10 nm to 90 nm. When the total amount of the non-volatile content of the liquid composition was 100% by mass, the total content ratio of the fluorine-based functional group component (A), the carboxylic acid compound (B), and the titanium oxynitride particles (C) was 40% to 80% by mass, and '(A) / (C)' was in the range of 0.01 to 0.50, satisfying the scope of the invention of the first aspect. Therefore, both the contact angles of water and n-hexadecane and the appearance of the film were good, and all the film adhesion tests were qualified. Also, the maximum light transmittance of the coating film in the wavelength range of 380 nm to 780 nm was 3.6% to 23.8%, which was 25% or less, and black films were obtained in all cases. In particular, in Example 3, since the content ratio of the titanium oxynitride particles in the liquid composition was high, the maximum light transmittance was very low at 3.6%.

Industrial Applicability

[0090] The liquid composition for forming a water and oil repellent black film of the present invention is used in the field of preventing dirt in interior products such as kitchens and washrooms where design is required, and vehicle interior members such as instrument panels, air conditioners, car navigators, and audio systems in vehicles.

Explanation of Symbols

[0091] 1 Substrate 2 Water and oil repellent black film 3 Fluorine-containing titanium oxynitride particles 4 Silica sol-gel

Claims

1. A liquid composition for forming a water- and oil-repellent black film, comprising: titanium oxynitride particles (C) having a specific surface area diameter of 10 nm to 90 nm, to which a fluorine-based functional group component (A) containing a perfluoroether structure represented by the following general formula (1) or formula (2) and a carboxylic acid compound (B) are bonded; silica sol-gel (D); and a solvent (E). When the total amount of the non-volatile components of the liquid composition is 100% by mass, the total content ratio of the fluorine-based functional group component (A), the carboxylic acid compound (B), and the titanium oxynitride particles (C) is 40% by mass to 80% by mass. The liquid composition is characterized in that the mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) is in the range of 0.01 to 0.

50. When the total amount of the non-volatile components of the liquid composition is 100% by mass, the total content ratio of the fluorine-based functional group component (A), the carboxylic acid compound (B), and the titanium oxynitride particles (C) is 40% by mass to 80% by mass. A liquid composition for forming a water- and oil-repellent black film, characterized in that the mass ratio (A / C) of the fluorine-based functional group component (A) to the titanium oxynitride particles (C) is in the range of 0.01 to 0.

50. 【Chemical Formula 1】 In the above formulas (1) and (2), p, q, and r are each an integer of 1 to 6, which may be the same or different from each other, and the carbon skeleton may be linear or branched. In the above formulas (1) and (2), X is a hydrocarbon group having 2 to 10 carbon atoms, which may contain one or more bonds selected from an ether bond, a CO-NH bond, an O-CO-NH bond, and a sulfonamide bond. Furthermore, in the above formulas (1) and (2), Y is a hydrolysis product of silane or a main component of silica sol-gel.

2. The liquid composition for forming a water- and oil-repellent black film according to Claim 1, wherein when a coating film is formed under the condition of a film thickness of 1.0 μm, the maximum light transmittance of the coating film in the wavelength range of 380 nm to 780 nm is 25% or less.

3. The liquid composition for forming a water- and oil-repellent black film according to Claim 1 or 2, wherein the solvent (E) is a mixed solvent of water and an alcohol having 1 to 4 carbon atoms, or a mixed solvent of water, an alcohol having 1 to 4 carbon atoms, and an organic solvent other than the alcohol having 1 to 4 carbon atoms.

4. A method for producing a liquid composition for forming a water- and oil-repellent black film, comprising mixing an aqueous dispersion of fluorine-containing titanium oxynitride particles, a silica sol-gel solution, and a solvent.

5. The method for producing a liquid composition for forming a water- and oil-repellent black film according to Claim 4, wherein the aqueous dispersion of fluorine-containing titanium oxynitride particles is prepared by adding and mixing a fluorine-based compound to an aqueous dispersion of titanium oxynitride particles.

6. The method for producing a liquid composition for forming a water- and oil-repellent black film according to Claim 4, wherein the silica sol-gel solution is prepared by adding and mixing a catalyst to a mixed solution of a silicon alkoxide, an alcohol, and water.

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