Water-repellent coating

Abstract

To provide a water-repellent coating capable of retaining high levels of transparency, hydrophobicity, and dispersibility.SOLUTION: The present invention relates to a water-repellent coating.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a water-repellent coating material. [Background technology]

[0002] Patent Document 1 discloses an antibacterial liquid containing antibacterial agent microparticles, a binder, and a solvent, wherein the antibacterial agent microparticles contain silver-supported inorganic oxide, the binder contains at least one compound having a siloxane bond, the solvent contains alcohol and water, the solids concentration relative to the total mass of the antibacterial liquid is less than 5 mass%, and the content of the compound having a siloxane bond relative to the total solids content of the antibacterial liquid is 60 mass% or more. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2017-043599 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a water-repellent coating material that maintains high transparency, water repellency, dispersibility, etc. [Means for solving the problem]

[0005] The present invention includes the following water-repellent coating material.

[0006] Section 1. A water-repellent paint, (A) a Ti compound, (B) a Si compound; (C) Contains an F compound, The (A) Ti compound has an average primary particle size of 1 nm to 50 nm and is a hydrolysis product. The (B) Si compound is a hydrolysis product of an alkoxysilane. Water-repellent paint.

[0007] Section 2. The (C)F compound is represented by the following formula (1): CF3(CF2) a (CH2) b Si(R) c (1) (In formula (1), a represents an integer of 1 to 20. In the formula (1), b represents an integer of 0 to 10. In formula (1), c represents an integer of 1 to 3. In formula (1), R may be the same or different and each represents a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted alkoxy group. Item 2. The water-repellent coating material according to Item 1, wherein the water-repellent coating material is a hydrolysis product of a compound having the formula:

[0008] Section 3. Item 2. The water-repellent coating according to item 1, wherein the water-repellent coating has a contact angle of water of 60° or more after being applied to a substrate.

[0009] Section 4. Item 2. The water-repellent coating according to item 1, wherein the (A) Ti compound has an average primary particle size of 1 nm to 20 nm.

[0010] Section 5. In water-repellent paint, Item 2. The water-repellent coating according to item 1, wherein the content of the (A) Ti compound is 0.01% by mass to 5% by mass.

[0011] Section 6. In water-repellent paint, Item 2. The water-repellent coating material according to item 1, wherein the content of the (B) Si compound is 0.01% by mass to 20% by mass.

[0012] Section 7. In water-repellent paint, Item 2. The water-repellent coating material according to item 1, wherein the content of the (C) F compound is 0.01% by mass to 20% by mass.

[0013] Section 8. Item 2. The water-repellent coating material according to Item 1, wherein the (C)F compound is a hydrolysis product of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane.

[0014] Section 9. Item 2. The water-repellent coating material according to Item 1, wherein the (B) Si compound is a hydrolysis product of tetraethyl orthosilicate (TEOS, tetraethoxysilane).

[0015] Section 10. Furthermore, (D) silver Item 1. The water-repellent coating material according to item 1, comprising:

[0016] Section 11. 11. An antibacterial and antiviral coating solution comprising the water-repellent paint according to any one of items 1 to 10.

[0017] Section 12. A method for producing a water-repellent paint, comprising: (1) A step of synthesizing a Ti compound in a solvent and providing an organic chain to the Ti compound (2) after step (1), a step of preparing titania-coated silver; and (3) After step (2), a step of mixing the titania-coated silver having an organic chain bonded thereto, a Si compound, and an F compound in a solvent to hydrolyze the Si compound and the F compound. A method for producing a water-repellent paint, comprising:

[0018] The method for producing a water-repellent coating material of the present invention preferably includes the steps of: (4) After the step (3), a high-pressure dispersion treatment is carried out to disperse the dispersion containing the titania-coated silver.

[0019] Titania-coated silver is silver (Ag) fine particles whose surfaces are partially coated with titania.

[0020] The water-repellent coating of the present invention uses nano-dispersed TiO2 particles to improve adhesion to the substrate, and furthermore, by using fluorosilane (a water-repellent material), it maintains photocatalytic activity, resulting in a water-repellent coating. [Effects of the Invention]

[0021] The present invention can provide a water-repellent coating material that maintains high transparency, water repellency, dispersibility, etc. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be described in detail below.

[0023] The embodiments of the present invention are intended to provide a better understanding of the gist of the invention, and unless otherwise specified, do not limit the content of the invention.

[0024] In this specification, the terms "comprise" and "contain" are concepts that encompass all of "comprise," "consist essentially of," and "consist only of."

[0025] In this specification, when a numerical range is expressed as "A to B," it means "not less than A and not more than B."

[0026] In this specification, the expressions parts, % and the like are generally used.

[0027] In this specification, unless otherwise specified, all parts by mass or % by mass (wt%) are used.

[0028] [1] Water-repellent paint TiO2 has photocatalytic activity and exhibits a photocatalytic effect under ultraviolet light environments, making it a material that is used in a variety of applications, including anti-fouling coatings for wallpaper, deodorizing coatings for automobiles, and hydrogen generation catalysts.

[0029] Titania-containing paints are generally hydrophilic and are often used for hydrophilic purposes, but there is a demand for water-repellent titania-containing paints for antifouling purposes, etc. In recent years, from the viewpoint of hygiene awareness, there is also a demand for titania-containing paints that have antibacterial and antiviral properties.

[0030] Prior art (Patent Document 1) discloses a functional coating that combines antibacterial microparticles. However, this prior art is unable to form a film with a water contact angle of 60° or less, and further study is needed to impart antifouling functionality (water repellency) in addition to antibacterial properties.

[0031] The conventional technology involves mixing titania particles with a water-repellent resin to produce a water-repellent photocatalyst. However, the conventional technology requires further study in terms of photocatalytic activity, adhesion, water repellency, etc.

[0032] The inventors have succeeded in producing a material (water-repellent paint) that maintains transparency, water repellency, dispersibility, etc. by adding organic matter to titanium oxide to control the surface state and then hydrolyzing it in the presence of fluoroalkoxysilane and alkoxysilane.

[0033] The water-repellent coating of the present invention uses nano-dispersed TiO2 particles to improve adhesion to the substrate, and furthermore, by using fluorosilane (a water-repellent material), it maintains photocatalytic activity, resulting in a water-repellent coating.

[0034] The present invention provides a water-repellent coating material that uses titanium oxide having organic chains on its surface and undergoes a sol-gel reaction with a silicon binder, resulting in excellent transparency, adhesion to substrates, solvent stability, etc. By using the water-repellent coating material of the present invention as a coating, it is possible to satisfactorily fix photocatalytic titanium oxide to a substrate, and form a coating layer on an article.

[0035] The water-repellent coating material of the present invention is (A) a Ti compound, (B) a Si compound; (C) Contains an F compound, The (A) Ti compound has an average primary particle size of 1 nm to 50 nm and is a hydrolysis product. The (B) Si compound is a hydrolysis product of an alkoxysilane.

[0036] (1-1)(A)Ti compound The water-repellent coating material of the present invention contains (A) a Ti compound, (B) a Si compound, and (C) a F compound, and the Ti compound (A) has an average primary particle size of 1 nm to 50 nm and is a hydrolysis product. The Ti compound (A) preferably has a structure in which a titania compound is supported on the periphery of silver fine particles (carrier), or a structure in which titania coats the periphery of silver fine particles (carrier) (titania-coated silver).

[0037] Water, inorganic acids, free organic acids, etc. generally evaporate almost completely at temperatures below 200°C.

[0038] In the titania compound (titania nanoparticles) of (A) Ti compound (preferably titania-coated silver), acetyl groups (CH3-C(=O)-, Ac), acetoxy groups (acetyloxy group, CH3-C(=O)-O-, AcO), etc. are bonded to at least some of the titanium atoms present on the surface, and these groups are gradually eliminated in the range of 200°C to 600°C. For example, in the case of acetoxy groups, they gradually eliminate in the range of 200°C to 600°C, peaking at about 260°C.

[0039] Titania compounds can improve the dispersibility of titania particles by adding an organic substance to the surface of fine titania particles.

[0040] The titania compound preferably has an organic chain such as an acetyl group or an acetoxy group bonded to at least some of the titanium atoms present on the surface, which can suppress aggregation of titania nanoparticles during drying or firing, making it less likely to crack, peel, etc., and providing particularly excellent coatability and transparency. The titania compound can suppress cracking, peeling, etc., and can easily firmly support metals, resulting in excellent visible light photocatalytic activity.

[0041] The titania compound can suppress the aggregation of titania nanoparticles during drying or firing, and is therefore particularly effective in suppressing cracking, peeling, and the like.

[0042] When titania compounds have organic chains such as acetyl groups or acetoxy groups on at least some of the titanium atoms present on the surface, these chains gradually leave the compound in the range of 200°C to 600°C. Therefore, when heated using a thermogravimetric differential thermal analyzer (TG-DTA), a large mass loss occurs above 200°C.

[0043] When titania compounds are heated using a thermogravimetric and differential thermal analyzer (TG-DTA), the mass loss at temperatures above 200°C indicates the number of organic chains, such as acetyl groups and acetoxy groups, that are bonded to titanium atoms on the surface.

[0044] In the water-repellent coating material of the present invention, the titanium (Ti) compound contained in the (A) Ti compound preferably exhibits a mass loss of 1% by mass or more at 200°C or higher when heated to 600°C using a thermogravimetry-differential thermal analyzer. The mass loss of the Ti compound at 200°C or higher when heated to 600°C using a thermogravimetry-differential thermal analyzer (TG-DTA) is 0.1% by mass or more, preferably 1% by mass or more, and more preferably 5% by mass or more. The upper limit of the mass loss of the Ti compound is preferably 20% by mass.

[0045] The detailed conditions for the thermogravimetry-differential thermal analyzer (TG-DTA) were as follows: atmosphere: air, temperature rise rate: 3°C / min.

[0046] The organic chain (acetyl group, acetoxy group, etc.) present on the surface of the Ti compound is preferably an acetyl group (CH3-C(=O)-), an acetoxy group (CH3-C(=O)-O-), etc., from the viewpoints of water solubility, odor, volatility, harmfulness, decomposability, etc.

[0047] The organic chain may be bonded with at least one type of organic chain selected from the group consisting of the above organic chains, and one type of organic chain may be bonded alone, or two or more types of organic chains may be bonded depending on the purpose.

[0048] In the water-repellent coating material of the present invention, the Ti compound contained in (A) Ti compound preferably has an average primary particle size of 1 nm to 20 nm. The average primary particle size of the Ti compound is preferably 1 nm to 50 nm, more preferably 1 nm to 20 nm, and even more preferably 1 nm to 10 nm. By adjusting the average particle size of the Ti compound within this range, it becomes possible to partially coat the periphery of silver with Ti. Titania nanoparticles have higher visible light catalytic activity and can form a film with higher transparency. The Ti compound has excellent coatability.

[0049] The average particle size of the Ti compound (titania nanoparticles) is measured by observation with a transmission electron microscope (TEM).

[0050] The specific surface area of ​​the Ti compound is preferably 150 m 2 / g~500m 2 / g, more preferably 200m 2 / g~400m 2 / g. By adjusting the specific surface area of ​​the Ti compound to this range, it is possible to coat the Ti compound with metal (silver and copper), with Ti partially covering the silver to an appropriate extent. Ti compounds have high visible light catalytic activity.

[0051] The specific surface area of ​​the Ti compound is measured by the BET method.

[0052] The Ti compound can have N, Cl, and S element concentrations of 0 to 5,000 ppm, and more preferably 0 to 1,000 ppm. By adjusting the N, Cl, and S element concentrations of the Ti compound within this range, corrosion of the substrate can be suppressed. The N, Cl, and S element concentrations of the Ti compound mean that impurities derived from acidic Ti compound precursors such as TiCl4 and TiOSO4 are absent or present in very small amounts.

[0053] The concentrations of N, Cl, and S elements in the Ti compound are measured by WDX (fluorescent X-ray).

[0054] The crystalline form of the Ti compound is preferably anatase type, and the titania nanoparticles are preferably 100% anatase type, not including any crystalline form other than anatase type. By adopting anatase type Ti compound, the visible light catalytic activity of the Ti compound is improved.

[0055] In the water-repellent coating material of the present invention, the Ag compound contained in the (A) Ti compound preferably has an average primary particle size of 1 nm to 2,000 nm.

[0056] (D) Silver The water-repellent coating material of the present invention contains (A) a Ti compound, (B) a Si compound, and (C) a F compound, and preferably further contains (D) silver. In the water-repellent coating material of the present invention, the (A) Ti compound preferably has a structure in which a titania compound is supported on the periphery of silver fine particles (carrier), or a structure in which titania coats the periphery of silver fine particles (carrier) (titania-coated silver).

[0057] Definition of partial cover The Ti compound (titania-coated silver) is imaged using an electron microscope (scanning electron microscope (SEM) or transmission electron microscope (TEM)), and the locations of Ag and Ti particles are clarified by elemental analysis (energy dispersive X-ray analysis (EDS), electron probe microanalyzer (EPMA), electron energy loss spectroscopy (EELS), etc.). Ten Ag particles are then randomly selected and sorted by particle size. Focus is then placed on the fifth and sixth smallest Ag nanoparticles, which are then binarized using image processing software such as WinROOF (Mitani Corporation).

[0058] (A) Particle size ratio α(Ag) / β(Ti) The particle diameter of the Ag particles is defined as α (nm) and the particle diameter of the Ti particles is defined as β (nm). Based on this, α / β is calculated. α / β is preferably 1 / 2 or more.

[0059] By adjusting the ratio α(Ag particles) / β(Ti particles) to 1 / 2 or more (i.e., the silver nanoparticles are relatively large), the transparency of the dispersion containing titania-coated silver can be maintained. α(Ag) / β(Ti) is more preferably adjusted to 1 to 1,000, and even more preferably adjusted to 1 to 100.

[0060] (B) Coverage of Ag particles As a result of this binarization process, the area of ​​the Ag particle domain is defined as A, and the area of ​​the Ti particle domain that overlaps with the Ag nanoparticle is defined as B. Based on this result, the coverage rate is defined as B (Ti particle) / A (Ag particle) × 100 (%).

[0061] When the Ag particles are completely covered with the Ti particles, the coverage rate is 100%.

[0062] When an Ag particle exists alone, the coverage rate is 0%, and the Ag particle is not covered by the Ti particle.

[0063] In the water-repellent coating material of the present invention, the (A) Ti compound is preferably coated with titania over 1 to 99% of the surface of the silver fine particles. The coating rate of the Ti compound is preferably 1 to 99%, more preferably 10 to 80%, and even more preferably 20 to 70%. By adjusting the coating rate of the Ti compound with titania within the above range, the Ti compound exhibits good antibacterial and antiviral activity, and a dispersion containing the Ti compound has good dispersion stability.

[0064] If the coverage rate of the Ti compound exceeds 99%, the exposure rate of the Ag particles decreases, which may result in a decrease in antiviral performance. If the coverage rate of the Ti compound is less than 1%, the stability of the Ag particles in the Ti compound or dispersion may decrease. By adjusting the coverage rate (B (Ti particles) / A (Ag particles) × 100 (%)) to 1 surface% to 99 surface%, the Ti compound can partially cover the surface of the Ag particles, improving antiviral performance and improving the stability of the dispersion containing the Ti compound.

[0065] (1-2)(B) Si compound (Si binder) The water-repellent coating of the present invention contains (A) a Ti compound, (B) a Si compound, and (C) a F compound, and (B) the Si compound is a hydrolysis product of an alkoxysilane.

[0066] The water-repellent coating of the present invention contains a Ti compound (titania particles), and by adding an organic substance to the surface of fine titania particles, the dispersibility of the titania particles can be improved.

[0067] Titanium compounds (titania particles) are mixed with alkoxysilanes (Si compounds), which are the raw materials for binders, and by allowing the two to coexist, a hydrolysis reaction is carried out while maintaining high dispersibility, making it possible to produce a titania particle composite binder.

[0068] The water-repellent coating of the present invention can improve the cohesion of titania, and can greatly improve the solvent stability and adhesion.

[0069] (B) Si compounds are hydrolysis products of alkoxysilanes (alkylsilanes).

[0070] The alkoxysilane (alkylsilane) preferably used is a monoalkoxysilane, a dialkoxysilane, a trialkoxysilane, or a tetraethoxysilane.

[0071] The monoalkoxysilane preferably used is trimethylmethoxysilane, trimethylethoxysilane, or the like.

[0072] As the dialkoxysilane, preferably dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, diisobutyldimethoxysilane, dimethoxymethyl-n-octylsilane, or the like is used, and more preferably dimethyldimethoxysilane, dimethyldiethoxysilane, or the like is used.

[0073] The trialkoxysilane is preferably methyltrimethoxysilane, methyltriethoxysilane, methyltrippropoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrippropoxysilane, ethyltriisopropoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltrippropoxysilane, n-propyltriisopropoxysilane, isopropyltrimethoxysilane, isopropyltrimethoxysilane, isopropyl Tripropoxysilane, n-butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, etc. are used, and more preferably methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, etc. are used.

[0074] The tetraalkoxysilane is preferably tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, or the like, and more preferably tetraethoxysilane (tetraethyl orthosilicate, Si(OC2H5)4, TEOS), tetramethoxysilane, or the like.

[0075] The alkylsilane may be at least one compound selected from the group consisting of the alkylsilanes described above. These alkylsilanes may be used alone or in combination (blended) in two or more types depending on the purpose.

[0076] In the water-repellent coating material of the present invention, the Si compound is particularly preferably a hydrolysis product of TEOS (tetraethyl orthosilicate, tetraethoxysilane).

[0077] (1-3)(C)F compound The water-repellent coating material of the present invention contains (A) a Ti compound, (B) a Si compound, and (C) a F compound.

[0078] The (C)F compound is preferably the hydrolysis product of a compound having formula (1): CF3(CF2) a (CH2) b Si(R) c (1)

[0079] In formula (1), a represents an integer of 1 to 20. In the formula (1), b represents an integer of 0 to 10. In formula (1), c represents an integer of 1 to 3. In formula (1), R may be the same or different and each represents a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted alkoxy group.

[0080] The (C)F compound is preferably a hydrolysis product of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, dimethoxy(methyl)(3,3,3-trifluoropropyl)silane, triethoxy[5,5,6,6,7,7,7-heptafluoro-4,4-bis(trifluoromethyl)heptyl]silane, trimethoxy(1H,1H,2H,2H-tridecafluoro-n-octyl)silane, trimethoxy(1H,1H,2H,2H-nonafluorohexyl)silane, trimethoxy(3,3,3-trifluoropropyl)silane, triethoxy(1H,1H,2H,2H-nonafluorohexyl)silane, triethoxy-1H,1H,2H,2H-tridecafluoro-n-octylsilane, or the like.

[0081] The (C)F compound is preferably a hydrolysis product of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, or the like, and more preferably a hydrolysis product of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane.

[0082] The F compound may be at least one compound selected from the group consisting of the above-mentioned F compounds, and these F compounds may be used alone or in combination (blended) of two or more types depending on the purpose.

[0083] (1-4)(E) Solvent The water-repellent coating material of the present invention contains (A) a Ti compound, (B) a Si compound, and (C) a F compound, and preferably further contains (E) a solvent.

[0084] In the water-repellent coating of the present invention, the solvent (E) preferably contains water and alcohol.

[0085] The alcohol is preferably an aliphatic alcohol having 1 to 6 carbon atoms, such as methanol, ethanol, propanol, or isopropanol; a non-aliphatic alcohol, such as α-terpineol; a glycol solvent, such as butyl carbitol (diethylene glycol monobutyl ether), hexylene glycol (2-methyl-2,4-pentanediol), ethylene glycol-2-ethylhexyl ether, ethylene glycol monomethyl ether, or propylene glycol monomethyl ether; or a diol, such as 1,4-butanediol, 1,5-pentanediol, or 1,6-hexanediol.

[0086] The alcohol may be at least one compound selected from the group consisting of the above alcohols, and these alcohols may be used alone or in combination (blended) of two or more depending on the purpose.

[0087] The solvent of the water-repellent paint of the present invention can be changed. The water may be removed from the reaction solution by centrifuging the water-repellent paint, filtering through a membrane, or the like, and the water may be replaced with an organic solvent.

[0088] (1-5) Water-repellent paint In the water-repellent coating material of the present invention, the ratio of the average primary particle size of the Ag compound to the average primary particle size of the Ti compound contained in (A) the Ti compound (preferably titania-coated silver) (average primary particle size of Ag compound / average primary particle size of Ti compound) is preferably 2 to 100.

[0089] In the water-repellent coating material, the content of the Ti compound contained in (A) Ti compound is preferably 0.01% by mass to 5% by mass.

[0090] In the water-repellent coating material, the content of the (B) Si compound is preferably 0.01% by mass to 20% by mass.

[0091] In the water-repellent coating material, the content of the (C)F compound is preferably 0.01% by mass to 20% by mass.

[0092] (1-6) Contact angle of water-repellent paint (°) The water-repellent coating material of the present invention preferably has a water contact angle of 60° or more after application to a substrate. The contact angle of the water-repellent coating material is more preferably 90° or more, and even more preferably 120° or more. Since the water-repellent coating material of the present invention has a contact angle of 60° or more, a coating film formed from the water-repellent coating material has excellent water-repellent and anti-fouling properties. In order for the coating film formed from the water-repellent coating material of the present invention to exhibit good water-repellent and anti-fouling properties, a higher contact angle is basically better.

[0093] The contact angle (°) is measured using a water-repellent coating material (coating composition, dispersion) using a contact angle meter (DM400) manufactured by Kyowa Interface Science Co., Ltd. in accordance with JIS R 3257.

[0094] (1-7) Water-repellent paints, antibacterial and antiviral coating solutions, and coating films In the water-repellent coating of the present invention, the dispersibility of the Ti compound (titania particles) can be improved by adding an organic substance to the fine titania surface. By mixing the Ti compound (titania particles) with alkoxysilane (Si compound), which is the raw material for the binder, and maintaining high dispersibility by coexistence of the two, a hydrolysis reaction can be carried out to produce a titania particle composite binder.

[0095] The water-repellent coating of the present invention can improve titania aggregation, significantly improving the solvent stability of the coating and the adhesion of the coating film. The water-repellent coating of the present invention has good dispersibility, resulting in excellent crack resistance of the coating. The water-repellent coating of the present invention also enables dense titania coating, and is excellent in applicability and transparency, as well as visible light catalytic activity.

[0096] In the water-repellent coating material of the present invention, the content of the Ti compound in the composition is preferably 0.01 to 5% by mass from the viewpoints of ease of coating, film properties of the coating, and the like.

[0097] In the water-repellent coating material of the present invention, the content of the Si compound in the composition is preferably 0.01% by mass to 20% by mass from the viewpoints of ease of coating, film properties of the coating, and the like.

[0098] In the water-repellent coating material of the present invention, the content ratio of the Ti compound and the Si compound in the composition is preferably 0.02 to 20 (0.02 parts by mass to 20 parts by mass) of the Ti compound relative to the Si compound (1 part by mass), more preferably 0.1 to 1 (0.1 parts by mass to 1 part by mass), from the viewpoints of ease of coating, film properties of the coating, etc.

[0099] The pH of the water-repellent coating material (dispersion) of the present invention varies depending on the type of metal added and the amount of metal added, but is preferably 1 to 5, more preferably 2 to 4, from the viewpoint of coatability. The present invention includes an antibacterial and antiviral coating liquid containing the water-repellent paint of the present invention.

[0100] The viscosity of the water-repellent coating material of the present invention is preferably adjusted according to the intended use. When the coating material is to be applied by spin coating, dip coating, spraying, or the like, the viscosity is preferably adjusted to a low level. When the coating material is to be applied by brush coating, squeegeeing, or the like, the viscosity is preferably adjusted to a higher level. When the coating material is to be applied by screen printing, the viscosity is preferably adjusted to a higher level to suppress flowability.

[0101] The coating film formed by the antibacterial and antiviral coating liquid containing the water-repellent paint of the present invention allows for a dense coating.

[0102] The present invention includes an antibacterial and antiviral coating film (paint film) formed using an antibacterial and antiviral coating liquid containing the water-repellent paint of the present invention.

[0103] The coated product having a coating film is not particularly limited, and examples thereof include building materials, building exteriors, building interiors, window frames, window glass, various lenses, structural members, building facilities such as housing, cooking utensils, textile products, furniture, displays, display protective films, plumbing members, vehicle light covers and window glass, exteriors of machinery or articles, dustproof covers and paints, display devices, their covers, traffic signs, various display devices, signs such as billboards, sound insulation walls for roads and railways, exteriors and paints of bridges and guardrails, interiors and paints of tunnels, insulators, solar cell covers, solar hot water heater heat collector covers, and exterior parts of electronic and electrical equipment used outdoors, particularly transparent members, exteriors of vinyl greenhouses, greenhouses, etc.

[0104] [2] Manufacturing method of water-repellent paint The method for producing the water-repellent coating material of the present invention comprises the steps of: (1) A step of synthesizing a Ti compound in a solvent and providing an organic chain to the Ti compound (2) after step (1), a step of preparing titania-coated silver; and (3) After the step (2), the method includes a step of mixing the titania-coated silver having an organic chain bonded thereto, a Si compound, and an F compound in a solvent, and hydrolyzing the Si compound and the F compound.

[0105] The method for producing a water-repellent coating material of the present invention preferably includes the steps of: (4) After the step (3), a high-pressure dispersion treatment is carried out to disperse the dispersion containing the titania-coated silver.

[0106] Titania-coated silver is silver (Ag) fine particles whose surfaces are partially coated with titania.

[0107] (2-1) (1) A step of synthesizing a Ti compound in a solvent and providing an organic chain to the Ti compound In the production method of the present invention, first, an organic substance is applied to the surface of fine titania particles to improve the dispersibility of the titania particles.

[0108] In step (1), an organic chain is bonded to the surface of a Ti compound in a solvent.

[0109] The Ti compound (titanium-containing substance) is preferably a substance that becomes titanium oxide when heated. The titanium-containing substance is preferably titanium oxide and / or a titanium oxide precursor, and more preferably titanium oxide; titanium hydroxide; titanium alkoxide; titanium halides such as titanium trichloride and titanium tetrachloride (particularly those neutralized with a base); metallic titanium, etc.

[0110] The titanium-containing substance is preferably titanium alkoxide, titanium hydroxide, or titanium halide (particularly, one neutralized with a base) from the viewpoints of the dispersibility, coatability, transparency, and visible light photocatalytic activity of the resulting titania. The titanium-containing substance is more preferably titanium alkoxide from the viewpoints of purity, dispersibility, coatability, transparency, and visible light photocatalytic activity.

[0111] The titanium alkoxide is preferably titanium tetraisopropoxide, titanium tetra n-butoxide, titanium tetra n-propoxide, titanium tetraethoxide, etc. From the viewpoints of cost, water solubility of by-products, coatability, and visible light catalytic property, the titanium alkoxide is more preferably titanium tetraisopropoxide.

[0112] The Ti compound may be at least one compound selected from the group consisting of the above Ti compounds, and these Ti compounds may be used alone or in combination (blended) of two or more types depending on the purpose.

[0113] The average particle size of the Ti compound is preferably 100 nm or less, more preferably 50 nm or less. There is no particular lower limit for the average particle size of the titanium-containing substance, and it is preferably about 1 nm. When the particle size is large, it is preferably ground using a planetary ball mill, paint shaker, or the like in a dry or wet manner before use.

[0114] The average particle size of a Ti compound (solid such as titanium oxide or metallic titanium) is measured by observation with a transmission electron microscope (TEM).

[0115] The concentration of the Ti compound in the dispersion is preferably 0.01 mol / L to 5 mol / L, more preferably 0.05 mol / L to 3 mol / L, from the viewpoints of productivity, viscosity of the reaction liquid, coatability, transparency, and visible light catalytic properties.

[0116] The acid used in the reaction is an organic acid, and since a volatile acid is preferred, it is preferably an acid represented by the chemical formula C n H 2n+1 Monocarboxylic acids represented by COOH (n=0 to 3) (monocarboxylic acids having 1 to 4 carbon atoms), hydroxycarboxylic acids having 2 to 3 carbon atoms, etc. are used.

[0117] The monocarboxylic acid is preferably formic acid where n=0, or acetic acid where n=1, from the viewpoints of volatility, toxicity, and decomposition.

[0118] The hydroxycarboxylic acid is preferably glycolic acid, lactic acid, or the like, and from the viewpoints of water solubility and odor, more preferably acetic acid, glycolic acid, lactic acid, or the like.

[0119] The organic acid may be at least one compound selected from the group consisting of the above organic acids, and these organic acids may be used alone or in combination (blended) in two or more types depending on the purpose.

[0120] From the viewpoints of dispersibility, coatability, transparency, visible light catalytic activity, and cost, the amount of organic acid used is preferably adjusted so that the number of moles of acyloxy groups per mole of titanium in the Ti compound is 1.5 moles or more, and particularly preferably 2 moles or more. The amount of organic acid used can improve stability over time, coatability, transparency, etc., as the organic acid is used in greater amounts. There are no particular restrictions on the upper limit of the amount of organic acid used, and the amount is preferably adjusted so that the number of moles of acyloxy groups per mole of titanium in the Ti compound is 10 moles or less.

[0121] The concentration of the organic acid in the dispersion is preferably 0.02 mol / L to 10 mol / L, more preferably 0.1 mol / L to 7 mol / L, from the viewpoints of dispersibility, coatability, transparency, visible light catalytic properties, and cost.

[0122] The reaction solvent is preferably an aqueous solvent such as water, which is used as the main component (preferably 50% by mass or more). The reaction solvent may contain an alcohol or an ester during the reaction.

[0123] When titanium tetraisopropoxide is used as a raw material, the reaction solvent with an organic acid generates isopropyl alcohol. Heating can also generate isopropyl esters of organic acids. The alcohol or ester may be added to the dispersion, or it may be generated in the system. The alcohol or ester may be removed by heating in an open system below 100°C, by reducing the pressure, or it may remain in the reaction solution.

[0124] When alcohol is contained in the dispersion, the average particle size of the resulting Ti compound (titania nanoparticles) tends to be small, and alcohol may be intentionally added to control the average particle size.

[0125] The pH of the dispersion is preferably 2 or more and less than 6, more preferably 2.1 to 5, from the viewpoints of corrosion of the device, safety in handling, dispersibility, and the like.

[0126] The method for preparing the dispersion is not particularly limited, and the Ti compound, organic acid, and water (solvent) may be mixed simultaneously or sequentially. On a mass production scale, from the viewpoint of preventing aggregation and forming large lumps and facilitating continuous stirring, it is preferable to mix the organic acid and water (solvent) first, and then add the titanium-containing substance while stirring. On a laboratory scale, it is preferable to mix the titanium-containing substance and organic acid first, and then add water while stirring.

[0127] (2-2) (2) Step of preparing titania-coated silver after step (1) Titania-coated silver can be produced by irradiating a composite of a Ti compound and a silver compound with ultraviolet light. In the water-repellent coating material of the present invention, the Ti compound (A) preferably has a structure in which a titania compound is supported on the periphery of silver fine particles (carrier), or a structure in which titania coats the periphery of silver fine particles (carrier) (titania-coated silver).

[0128] High-pressure dispersion method (pressure treatment) It is desirable to disperse Ti compounds (titania compounds) using a dispersing device that generates high pressure by collision of particles, such as a jet mill, which can highly disperse titania particles in a liquid, making it possible to partially coat the titania.

[0129] A dispersion containing a Ti compound (preferably titania fine particles) is subjected to a pressure treatment of 30 MPa or more (high pressure dispersion method).

[0130] By applying pressure treatment, the Ti compound becomes finer.

[0131] The pressure level when carrying out the pressure treatment is not particularly limited as long as it can sufficiently atomize the Ti compound. The pressure level is preferably adjusted to 30 MPa or more, more preferably adjusted to 50 MPa to 400 MPa, and even more preferably adjusted to 100 MPa to 300 MPa. The pressure treatment is preferably carried out using a high-pressure dispersion device. The high-pressure dispersion device can disperse the Ti compound by applying mechanical pressure.

[0132] By applying pressure, for example, (i) Colliding two or more dispersions of Ti compounds with each other; (ii) Colliding a dispersion of Ti compounds with a metal or ceramic material (a high-hardness material such as silicon carbide or alumina); (iii) Dispersion of the Ti compound with a cross-sectional area of ​​1 cm 2 Passing through the following spaces Processing such as the above is performed.

[0133] By applying pressure, it is possible to make the pressure conditions stronger, which allows for more efficient atomization of the Ti compound and further reduces the processing time.

[0134] The pressurization operation is preferably carried out once or more, more preferably ten or more times.

[0135] The pressurizing temperature is not particularly limited. The pressurizing temperature is adjusted to a temperature at which the carbonaceous material having a layered structure can be sufficiently exfoliated. The pressurizing temperatures in (i) and (ii) are preferably adjusted to 0°C to 100°C, more preferably 20°C to 95°C. The pressurizing temperature in (iii) is preferably adjusted to 0°C to 100°C when mechanical pressure is applied. The pressurizing temperature in (iii) is preferably adjusted to 373°C to 700°C, more preferably 380°C to 450°C when pressure is generated by the supercritical state of water.

[0136] When the pressure treatment is carried out, it is preferable to carry out a preliminary treatment (pretreatment) in which the dispersion liquid containing the Ti compound is subjected to an ultrasonic dispersion treatment to atomize the Ti compound, which can have the effect of preventing clogging in a high-pressure dispersion device, a supercritical water production device, etc.

[0137] The output power during ultrasonic dispersion treatment is not particularly limited. From the viewpoint of atomization of the Ti compound, the output power during ultrasonic dispersion treatment is preferably adjusted to be stronger than that of a commonly performed ultrasonic dispersion treatment (about 40 W to 50 W). The output power during ultrasonic dispersion treatment is preferably adjusted to 100 W or more, more preferably adjusted to 300 W to 20,000 W, and even more preferably adjusted to 400 W to 18,000 W.

[0138] The ultrasonic dispersion temperature is not particularly limited. The ultrasonic dispersion temperature is preferably adjusted to a temperature at which the Ti compound can be sufficiently atomized. The ultrasonic dispersion temperature is preferably adjusted to 0°C to 80°C, more preferably 10°C to 70°C.

[0139] The ultrasonic dispersion time is not particularly limited. The ultrasonic dispersion time is preferably adjusted to a time that allows sufficient atomization of the Ti compound. The ultrasonic dispersion time is preferably adjusted to 1 to 600 minutes, more preferably 3 to 120 minutes.

[0140] As a pre-treatment or post-treatment of these treatments, dispersion treatment using other dispersion devices such as ordinary mechanical stirring, dispersion treatment using an emulsifying device, dispersion treatment using a bead mill, etc. may be used in combination.

[0141] UV light irradiation The ultraviolet light irradiation is preferably carried out below room temperature (20°C), more preferably at 15°C or below, from the viewpoints of ease of supporting silver on the Ti compound (titania nanoparticles) (titania-coated silver), visible light catalytic activity, reaction rate, productivity, aspect ratio controllability, discoloration resistance during low-intensity ultraviolet irradiation, visibility during high-intensity ultraviolet irradiation, and re-transparency in an ultraviolet-stopped environment. The lower limit of the temperature for ultraviolet light irradiation is not particularly limited, and is preferably 0°C when the reaction is carried out at normal pressure. During ultraviolet light irradiation, stirring is preferably carried out from the viewpoint of sufficiently reacting the dispersion with the silver salt. The stirring method is not particularly limited, and can be carried out according to a conventional method.

[0142] The reaction time for UV light irradiation is preferably 1.5 hours or more, and more preferably in the range of 1.5 to 36 hours. By adjusting the reaction time to 1.5 hours or more, inorganic oxide fine particles are favorably supported around the silver nanoparticles, and gelation of the silver nanoparticles does not occur. By adjusting the reaction time to 36 hours or less, the particle size of the silver nanoparticles is adjusted, and precipitation of the silver nanoparticles does not occur.

[0143] From the viewpoints of ease of loading, reaction rate, reaction controllability, and productivity, an ultraviolet irradiation device is preferably used that emits ultraviolet light having a wavelength of 280 nm to 500 nm. By adjusting the wavelength of ultraviolet light to a wavelength range of 280 nm or more, the dispersion stability of titania-coated silver is good. By adjusting the wavelength of ultraviolet light to a wavelength range of 500 nm or less, silver is efficiently reduced, and silver nanoparticles are efficiently produced.

[0144] The composition of the present invention preferably further contains at least one metal selected from the group consisting of silver, copper, and platinum.

[0145] When a silver salt is used as the silver compound, the silver salt is preferably a silver salt whose aqueous solution is acidic or neutral. The silver salt preferably includes silver chloride (I), silver nitrate (I), organic silver salts (silver lactate (I), silver acetate (I), silver citrate (I), silver myristate (I), etc.), silver sulfide (I), silver oxide (I), silver phosphate (I), silver carbonate (I), silver bromide (I), silver iodide (I), etc. The silver salt may be at least one compound selected from the group consisting of the above silver salts. These silver salts may be used singly or in a mixture (blend) of two or more types depending on the purpose.

[0146] The amount of silver salt used, calculated as the mass of silver element in the silver salt, relative to the titanium oxide in the Ti compound (titania nanoparticles), from the viewpoints of dispersibility, transparency, antimicrobial activity (antibacterial activity and antiviral activity), stability of the Ti compound (titania nanoparticles), etc., is preferably 50 mass% or less, more preferably 0.01 mass% to 40 mass%, and even more preferably 0.01 mass% to 25 mass%. By adjusting the amount of silver salt used within this range, it is easy to maintain coatability and transparency, and antibacterial activity, antiviral activity in dark places, and photocatalytic activity can be particularly improved.

[0147] Titania-coated silver can be recovered by conventional methods, such as by precipitating and centrifuging the titania-coated silver. The organic chains are bonded to titanium atoms present on the surface, and (A) titania-coated silver has a structure in which a titania compound is supported around silver particles (carrier), or a structure in which titania coats the silver particles (carrier).

[0148] (2-3) (3) After step (2), a step of mixing titania-coated silver having an organic chain bonded thereto, a Si compound, and an F compound in a solvent, and hydrolyzing the Si compound and the F compound. In step (3), titania-coated silver having organic chains bonded thereto, a Si compound, and an F compound are mixed in a solvent to hydrolyze the Si compound and the F compound (preparation of a coating liquid).

[0149] In the manufacturing method of the present invention, next, titania particles and alkoxysilane, which is the raw material for the binder, are mixed, and a hydrolysis reaction is carried out in the coexistence of the two while maintaining high dispersibility, to produce a titania particle composite binder.

[0150] The hydrolysis is preferably carried out by keeping the dispersion at a temperature of about 65° C. for about 15 hours with a lid on to prevent the solvent from volatilizing.

[0151] The hydrolysis is preferably carried out under normal pressure or under pressure in a closed vessel.

[0152] The pH of the dispersion is preferably 2 or more and less than 6, more preferably 2.1 to 5, from the viewpoints of corrosion of the device, safety in handling, dispersibility, and the like.

[0153] Organic substances (acetyl groups, acetoxy groups, etc.) bonded to the surface of the Ti compound (titania) in titania-coated silver react with Si compounds (alkylsilanes such as TEOS) and F compounds ((1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, etc.), and as the hydrolysis of the Si compounds and F compounds progresses (hydrolyzed alkylsilanes, hydrolyzed F compounds), a transparent coating liquid is obtained.

[0154] (2-4) (4) After step (3), a step of performing a high-pressure dispersion treatment to disperse the dispersion containing titania-coated silver. The coating liquid is preferably subjected to a high-pressure dispersion treatment (high-pressure dispersion method) to obtain a transparent dispersion liquid.

[0155] The manufacturing method of the present invention uses a new process to prepare a composition containing titania particles, thereby improving the aggregation of titania, which has been a problem in the past, and significantly improving solvent stability and adhesion. [Example]

[0156] The present invention will be specifically described below with reference to examples.

[0157] The present invention is not limited to the following specific examples.

[0158] [1] Manufacturing of water-repellent paint [Example 1] (Step 1) Preparation method of photocatalytic titanium oxide 30 g of acetic acid was added to 70 g of titanium tetraisopropoxide and stirred. Water was then added to bring the total volume to 400 g, and the mixture was stirred for 90 minutes. The reaction solution was then heated to 98°C and stirred for 9 hours using a hot stirrer, yielding a uniform titania sol. The resulting sol was subjected to ultrasonic dispersion for 30 minutes, yielding a transparent titania sol.

[0159] The TG-DTA of the obtained titania sol was measured by heating it up to 600°C at a temperature increase rate of 3°C / min in an air atmosphere, and the mass loss rate above 200°C was 10% by mass. This mass loss rate above 200°C is due to organic matter derived from acetic acid bonded to the titania surface. To adjust the concentration of the obtained titania sol, the titania sol was diluted with water to obtain a titania sol with a TiO2 concentration of 2% by mass (wt%).

[0160] The particle size of the obtained titania sol was observed by TEM, and the average particle size was found to be 3 nm.

[0161] (Step 2) Complexation with metal ions Silver nitrate was added to the titania sol with a TiO2 concentration of 2% by mass so that the weight ratio of Ag / TiO2 was 0.01, and the mixture was thoroughly stirred until it became homogeneous. Next, the titania sol was irradiated with an ultraviolet lamp for 24 hours to reduce the silver nitrate, and a silver composite titania sol was obtained.

[0162] (Step 3) Preparation of coating liquid 30 g of the prepared 2 mass % silver composite titania sol was mixed with 0.6 g of tetraethyl orthosilicate (TEOS), 0.6 g of 1-propanol, and (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane (CH 11 F 11SiO3)268.8g was added. After that, the reactor was covered to prevent the solvent from volatilizing, and the reaction mixture was kept at 60°C for 1 hour. The organic matter bonded to the titania surface, tetraethyl orthosilicate, and C3H 11 F 11 SiO3 reacts with tetraethyl orthosilicate, and C3H 11 F 11 As the hydrolysis of SiO3 progressed, a transparent coating solution was obtained.

[0163] The obtained liquid was subjected to a high pressure dispersion treatment (high pressure dispersion method) to obtain a transparent dispersion liquid.

[0164] [Example 2] In Example 2, a coating liquid was prepared in the same process as in Example 1, except that in step 1 of Example 1, the heating time of the hot stirrer was changed to 16 hours.

[0165] [Example 3] In Example 3, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 0.6 g of tetraethyl orthosilicate, 2.4 g of 1-propanol, and 177.0 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 120 g of 2 mass % silver composite titania sol.

[0166] [Example 4] In Example 4, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 2.4 g of tetraethyl orthosilicate, 2.4 g of 1-propanol, and 177.2 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 120 g of 2 mass % silver composite titania sol.

[0167] [Example 5] In Example 5, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 1.2 g of tetraethyl orthosilicate, 1.2 g of ethanol, and 177.6 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 120 g of 2 mass % silver composite titania sol.

[0168] [Example 6] In Example 6, a coating liquid was prepared in the same process as in Example 1, except that in step 1 of Example 1, the heating time of the hot stirrer was changed to 48 hours.

[0169] [Example 7] In Example 7, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 0.6 g of tetraethyl orthosilicate, 0.6 g of 1-propanol, and 297.84 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 1.5 g of 2 mass % silver composite titania sol.

[0170] [Example 8] In Example 8, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 0.6 g of tetraethyl orthosilicate, 0.6 g of 1-propanol, and 73.8 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 225 g of 2 mass % silver composite titania sol.

[0171] [Example 9] In Example 9, a coating solution was prepared in the same manner as in Example 1, except that in step 3 of Example 1, 0.03 g of tetraethyl orthosilicate, 0.6 g of 1-propanol, and 269.37 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 30 g of 2 mass% silver composite titania sol.

[0172] [Example 10] In Example 10, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 60 g of tetraethyl orthosilicate, 0.6 g of 1-propanol, and 209.40 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 30 g of 2 mass % silver composite titania sol.

[0173] [Example 11] In Example 11, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 0.06 g of tetraethyl orthosilicate, 0.03 g of 1-propanol, and 269.37 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 30 g of 2 mass % silver composite titania sol.

[0174] [Example 12] In Example 12, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 0.6 g of tetraethyl orthosilicate, 60 g of 1-propanol, and 209.40 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 30 g of 2 mass % silver composite titania sol.

[0175] [Example 13] In Example 13, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 0.6 g of tetraethyl orthosilicate, 0.6 g of 1-propanol, and 60 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 30 g of 2 mass % silver composite titania sol.

[0176] [Example 14] In Example 14, a coating liquid was prepared in the same process as in Example 1, except that in step 3 of Example 1, 1.2 g of tetraethyl orthosilicate, 1.2 g of 1-propanol, and 177.6 g of 1H,1H,2H,2H-perfluorooctyltriethoxysilane were added to 120 g of photocatalytic titanium oxide adjusted to 2 mass %.

[0177] [Comparative Example 1] In Comparative Example 1, a coating liquid was prepared in the same manner as in Example 1, except that 1.2 g of Vildek (manufactured by Dai Nippon Toryo Co., Ltd.), an acrylic resin and paint, 1.2 g of 1-propanol, and 177.6 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to 120 g of 2 mass % silver composite titania sol.

[0178] Comparative Example 2 In Comparative Example 2, 51 g of ethanol, 30 g of pure water, 1.1 g of MKC Silicate MS51 manufactured by Mitsubishi Chemical Corporation, 45 g of Aluminum Chelate D (diluted with ethanol: solid content concentration 1 wt%), 18 g of Emalex 715 manufactured by Nippon Emulsion Co., Ltd., and 3 g of sodium di(2-ethylhexyl)sulfosuccinate were mixed in a container.

[0179] Thereafter, 0.66 g of Fuji Chemical's silver-loaded glass bagtelite (solid content concentration 50 wt%), with an average particle size controlled to 1,000 nm, was added and stirred for 60 minutes to obtain an antibacterial solution.

[0180] Comparative Example 3 In Comparative Example 3, 51 g of ethanol, 30 g of pure water, 1.1 g of MKC Silicate MS51 manufactured by Mitsubishi Chemical Corporation, 4.5 g of Aluminum Chelate D (diluted with ethanol: solid content concentration 1 wt%), 18 g of Emalex 715 manufactured by Nippon Emulsion Co., Ltd., and 3 g of sodium di(2-ethylhexyl)sulfosuccinate were mixed in a container.

[0181] Thereafter, 1.3 g of Fuji Chemical's silver-loaded glass bagtelite (solid content concentration: 50 wt%), which had an average particle size controlled to 50 nm, was added and stirred for 60 minutes to obtain an antibacterial solution.

[0182] Comparative Example 4 In Comparative Example 4, 51 g of ethanol, 30 g of pure water, 1.1 g of MKC Silicate MS51 manufactured by Mitsubishi Chemical Corporation, 4.5 g of Aluminum Chelate D (diluted with ethanol: solid content concentration 1 wt%), 18 g of Emalex 715 manufactured by Nippon Emulsion Co., Ltd., 3 g of sodium di(2-ethylhexyl)sulfosuccinate, and 1.1 g of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane were added to a container and mixed.

[0183] Thereafter, 1.3 g of Fuji Chemical's silver-loaded glass bagtelite (solid content concentration 50 wt%), which had an average particle size controlled to 50 nm, was added and stirred for 60 minutes to obtain an antibacterial solution.

[0184] [2] Evaluation of water-repellent paints The obtained coating compositions of the Examples and Comparative Examples were evaluated as follows.

[0185] (1) Transparency of the dispersion The transparency of the coating composition (dispersion liquid) was measured by measuring the transmittance using an ultraviolet-visible spectrophotometer (Shimadzu UV3400). The highest transmittance value in the wavelength range of 400 nm to 800 nm was taken as the transmittance of the composition.

[0186] The criteria for judging the dispersion are as follows: ⊚: The dispersion has the highest transmittance of 80% or more. ◯: The dispersion has the highest transmittance of 50% or more. △: The dispersion has the highest transmittance of 20% or more. ×: The dispersion has a highest transmittance of less than 20%.

[0187] (2) Dispersibility (stability) of the dispersion liquid The coating composition (dispersion) was allowed to stand for 480 hours at 60° C. After standing, the dispersion was visually inspected to evaluate the dispersion stability.

[0188] The criteria for judging the dispersion are as follows: ⊚: No precipitation or gelation was observed in the dispersion. ◯: Separation is observed in the dispersion liquid, but it can be easily dispersed by stirring by hand. △: Separation is observed in the dispersion, but it can be redispersed by applying an external force such as ultrasonic waves. ×: Precipitation and gelation occurred in the dispersion, and it was not redispersible.

[0189] (3) Adhesion of the coating film (dispersion liquid) The coating composition (dispersion) was used to form a coating film on a substrate by spin coating. The spin coating was performed at 2,000 rpm for 60 seconds. After that, the adhesion was confirmed by touching with a finger, and the coating adhesion was evaluated according to the JIS K 5600_5_6 cross-cut test method.

[0190] The criteria for judging the coating are as follows: ⊚: The coating film peeled off from the substrate by 5% or less. ◯: The coating film peeled off from the substrate by 20% or less. △: The coating film peeled off from the substrate by 50% or less. ×: The coating film peeled off from the substrate by more than 50%, or peeled off when touched with a finger.

[0191] (4) Photocatalytic activity of the dispersion Transmittance Ta The dispersion (coating composition) was spin-coated onto a 1 mm thick glass substrate, which was then dried at 120°C. The transmittance at 587.6 nm (d-line: a wavelength close to the absorption peak of methylene blue) was measured using a UV-visible spectrophotometer (Shimadzu UV3400). This transmittance was designated as Ta.

[0192] Transmittance Tb Next, a 1 mmol / L solution of methylene blue was dropped onto the substrate, and after drying to remove excess solution, the transmittance at 587.6 nm (d-line: wavelength close to the absorption peak of methylene blue) was measured using a UV-visible spectrophotometer (Shimadzu UV3400). This transmittance was designated as Tb.

[0193] Degradation activity Tb / Ta Thereafter, ultraviolet light with a peak wavelength of 352 nm was irradiated using a black light, and measurements were taken every hour to measure the time it took for Tb / Ta to reach 90% and evaluate the decomposition activity of the photocatalyst.

[0194] The criteria for determining photocatalytic properties are as follows: ◎: The dispersion liquid takes 3 hours or less for Tb / Ta to become greater than 90%. ◯: The dispersion liquid takes 4 to 12 hours to reach Tb / Ta>90%. △: The dispersion liquid takes 13 to 24 hours for Tb / Ta to reach >90%. ×: The dispersion took 25 hours or more for Tb / Ta to reach 90%.

[0195] (5) Antiviral test After drying, the coating composition (dispersion) was subjected to an antiviral test in a dark place in accordance with ISO 21702 using Qβ phage (non-enveloped virus).

[0196] The criteria for judging the antiviral properties of a dispersion are as follows: ◎: The dispersion has an antiviral activity value of 2 or more. ×: The dispersion has an antiviral activity value of less than 2.

[0197] (6) Contact angle measurement The contact angle (°) of the coating composition (dispersion) was measured in accordance with JIS R 3257 using a contact angle meter (DM400) manufactured by Kyowa Interface Science Co., Ltd.

[0198] The results of the examples and comparative examples are shown in the table below.

[0199] [Table 1]

[0200] [Table 2]

[0201] [Table 3]

[0202] In Examples 1 to 14, coating compositions (water-repellent coating materials) were obtained that were excellent in the transparency of the dispersion, the dispersion stability of the dispersion, the adhesion of the coating film, the photocatalytic activity of the dispersion, the antiviral property of the dispersion, the water repellency of the dispersion (contact angle of the dispersion), and the like.

[0203] In Comparative Example 1, the coating composition caused precipitation and had a contact angle of 54°, indicating low water repellency.

[0204] [Industrial Applicability] The present invention provides a water-repellent coating material that uses titanium oxide having organic chains on its surface and undergoes a sol-gel reaction with a silicon binder, resulting in excellent transparency, adhesion to substrates, solvent stability, etc. By using the water-repellent coating material of the present invention as a coating, it is possible to satisfactorily fix photocatalytic titanium oxide to a substrate, and form a coating layer on an article.

Claims

1. A water-repellent paint, (A) a Ti compound, (B) a Si compound, (C) F compounds and Contains The (A) Ti compound has an average primary particle size of 1 nm to 50 nm and is a hydrolysis product. The (B) Si compound is a hydrolysis product of an alkoxysilane. Water-repellent paint.

2. The (C)F compound is represented by the following formula (1): CF 3 (CF 2 ) a (CH 2 ) b Si(R) c (1) (In formula (1), a represents an integer of 1 to 20. In formula (1), b represents an integer of 0 to 10. In formula (1), c represents an integer of 1 to 3. In formula (1), R may be the same or different and each represents a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted alkoxy group.

2. The water-repellent coating material according to claim 1, which is a hydrolysis product of a compound having the formula:

3. 2. The water-repellent coating according to claim 1, wherein the water-repellent coating has a contact angle of water of 60° or more after being applied to a substrate.

4. 2. The water-repellent coating according to claim 1, wherein the Ti compound (A) has an average primary particle size of 1 nm to 20 nm.

5. In water-repellent paint, 2. The water-repellent coating according to claim 1, wherein the content of the (A) Ti compound is 0.01% by mass to 5% by mass.

6. In water-repellent paint, 2. The water-repellent coating according to claim 1, wherein the content of the (B) Si compound is 0.01% by mass to 20% by mass.

7. In water-repellent paint, 2. The water-repellent coating according to claim 1, wherein the content of the (C) F compound is 0.01% by mass to 20% by mass.

8. 2. The water-repellent coating according to claim 1, wherein the (C)F compound is a hydrolysis product of (1H,1H,2H,2H-tridecafluorooctyl)trimethoxysilane.

9. 2. The water-repellent coating material according to claim 1, wherein the (B) Si compound is a hydrolysis product of tetraethyl orthosilicate (TEOS).

10. Furthermore, (D) silver The water-repellent paint according to claim 1, comprising:

11. An antibacterial and antiviral coating solution comprising the water-repellent paint according to any one of claims 1 to 10.

12. A method for producing a water-repellent paint, comprising: (1) A step of synthesizing a Ti compound in a solvent and providing an organic chain to the Ti compound (2) after step (1), a step of preparing titania-coated silver; and (3) After step (2), a step of mixing titania-coated silver having an organic chain bonded thereto, a Si compound, and an F compound in a solvent to hydrolyze the Si compound and the F compound. A method for producing a water-repellent paint, comprising:

Images