JP2012170859A - Method of manufacturing functional coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional coating film excellent in hydrophilic property, anti-reflection property and pencil hardness and having good crack resistance when it is a thick film.SOLUTION: This method of manufacturing a functional coating film includes a process of applying a coating composition containing (A) a water-soluble resin and (B) a hydrolyzable silicon-containing composition onto a base and then performing condensation and curing in a basic atmosphere. The functional coating film is obtained by the manufacturing method.

Description

  The present invention relates to a method for producing a functional coating film.

  In recent years, the global warming phenomenon has heightened awareness of the environment, and a new energy system that does not generate greenhouse gases such as carbon dioxide is attracting attention. Environmentally friendly renewable energy such as solar cell power generation and wind power generation does not emit carbon dioxide and other gases that are said to induce global warming, and therefore, research and development are being actively conducted as clean energy. Among them, solar cells and solar thermal power generation are attracting attention because they are excellent in safety and ease of handling.

  Typical solar thermal power generation methods include a centralized method (central tower method), a distributed method (parabolic trough), and a dish / sterling method. These are systems in which sunlight is condensed on a part by a reflecting mirror, and electric energy is obtained by thermoelectric conversion by the condensed heat. Therefore, in these methods, the key is to collect the light without loss, but as a factor that greatly affects the efficiency, a decrease in the reflectance due to the contamination of the reflecting mirror is particularly problematic. Similarly, a solar cell whose light-receiving surface is protected by a protective cover made of glass, weather resistant resin film, or the like also has a reduced light transmittance because the protective cover is contaminated with dust during long-term use. There is a similar problem that the energy conversion efficiency is reduced.

  As a technique for preventing surface contamination, for example, in Patent Document 1, a coating solution in which tungstic acid dissolved in ammonia water and distilled water are added is applied onto an anatase-type titanium oxide-containing layer and baked at 700 ° C. A technique for forming a surface layer by performing a treatment to form a layer made of tungsten oxide is disclosed. Attempts have also been made to improve antifouling properties by blending not only inorganic components but also organic components.

  On the other hand, as a technique for imparting antireflection performance to a substrate surface, for example, Patent Document 2 discloses that a silica-based thin film is obtained by using a sol solution adjusted by a sol-gel method for hydrolyzing and condensing alkoxysilane and silica fine particles. Techniques for forming the are disclosed.

  Patent Documents 3 and 4 disclose techniques relating to organic-inorganic composite compositions for the purpose of preventing contamination.

  In addition, as a technique for imparting antireflection properties and antifogging properties, for example, Patent Document 5 discloses that a precursor preparation which is a hydrolyzable silicate oligomer is coated on a substrate to hydrolyze a base, water, and oligomer. A method of forming a silica-like film by curing in a gas atmosphere containing a suppressor is disclosed.

JP-A-10-114545 Japanese Patent Laid-Open No. 10-13003 JP 2009-280770 A JP 2009-19072 A Special table 2008-542009

  However, in the techniques described in Patent Document 1, Patent Document 2, and Patent Document 5 and the like, since only inorganic components are blended, when a coating film is formed on the surface of a solar cell module, a large reflector, etc., cracks There is a problem that it is easy to occur and is easily peeled off. Moreover, the coating film formed from the coating composition of patent documents 1-4 has still room for improvement from a viewpoint of antireflection property, hydrophilic property, and crack resistance.

  This invention is made | formed in view of the said situation, and makes it one of the objectives to provide the functional coating film which is excellent in hydrophilic property, antireflection property, pencil hardness, and is excellent in the crack resistance at the time of thick film.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors applied a coating composition containing (A) a water-soluble resin and (B) a hydrolyzable silicon-containing compound on a base material, It discovered that the functional coating film which can solve the said subject was obtained by condensing and curing in an atmosphere, and came to complete this invention.

  That is, the present invention is as follows.

[1]
A method for producing a functional coating film comprising a step of condensing and curing in a basic atmosphere after a coating composition containing (A) a water-soluble resin and (B) a hydrolyzable silicon-containing compound is applied on a substrate. .

[2]
The method for producing a functional coating film according to [1], wherein the component (A) includes a polyvinyl alcohol resin.

[3]
The method for producing a functional coating film according to [1] or [2], wherein the coating composition further comprises (C) metal oxide particles having a number average particle diameter of 1 nm to 400 nm.

[4]
The method for producing a functional coating film according to any one of [1] to [3], wherein the coating composition further comprises (D) polymer particles.

[5]
The functional coating film obtained by the manufacturing method in any one of [1]-[4].

[6]
The functional coating film according to [5], which is for a protective member of a solar cell module.

[7]
The functional coating film according to [5], which is for a protective member for a light reflecting mirror.

[8]
A member comprising the functional coating film according to [5].

[9]
The solar cell module containing the functional coating film as described in [5].

[10]
A reflector device comprising the functional coating film according to [5].

  According to the present invention, it is possible to provide a coating composition having excellent hydrophilicity, antireflection properties and pencil hardness, and excellent crack resistance during thick film formation.

It is a schematic sectional drawing of an example of the solar cell module of this Embodiment. It is a schematic perspective view of an example of the reflector apparatus of this Embodiment.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are exemplifications for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.

  In the present specification, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto, “(meth) acrylate” means “acrylate” and corresponding methacrylate ”, and“ (meth) acrylate ”. “) Acryloyl” means “acryloyl” and its corresponding methacryloyl ”.

  The manufacturing method of the functional coating film of this Embodiment is, after apply | coating the coating composition containing (A) water-soluble resin and (B) hydrolyzable silicon containing compound on a base material, it condenses in a basic atmosphere. And a curing step. According to the production method, a functional coating film having excellent hydrophilicity, antireflection properties and pencil hardness and excellent crack resistance during thick film formation can be obtained.

  The hydrophilicity here can be expressed by the surface water contact angle at 23 ° C. The surface contact angle refers to an angle formed by the dried coating film and the tangent of a water droplet present on the surface, and can be measured by a droplet method. In the present embodiment, “hydrophilic” means that the contact angle of water (23 ° C.) with respect to the surface of the measurement target is preferably 60 degrees or less, more preferably 30 degrees or less, and even more preferably 20 degrees or less. It means to become.

  Hereinafter, components that can be blended in the coating composition and the coating film will be described.

[Coating composition]
The coating composition used in the method for producing a functional coating film of the present embodiment includes (A) a water-soluble resin and (B) a hydrolyzable silicon-containing compound.

<(A) Water-soluble resin>
In the present embodiment, the water-soluble resin (A) contained in the coating composition means a resin that can be dissolved in water. (A) component interacts uniformly with the below-mentioned (B) component, and the anti-reflective performance of a coating film becomes uniform in a surface area | region.

  Examples of the water-soluble resin (A) include polyvinyl alcohol resins [polyvinyl alcohol (PVA), acetoacetyl-modified polyvinyl alcohol, cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, polyvinyl acetal, etc.], polyvinyl acetal , Cellulose resin [methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), etc.], chitins, chitosans, starch, polyethylene oxide (PEO) which is a resin having an ether bond, Polypropylene oxide (PPO), polyethylene glycol (PEG), polyvinyl ether (PVE), tree having amide group or amide bond Polyacrylamide (PAAM) is polyvinyl pyrrolidone (PVP), polyacrylic acid salts having a carboxyl group as a dissociative group, maleic acid resins, alginates, gelatins and the like.

  These may be used alone or in combination of two or more.

  Among the above, the water-soluble resin (A) is preferably a polyvinyl alcohol resin. Polyvinyl alcohol is preferable because it has many hydroxyl groups per unit molecular weight, and the interaction such as hydrogen bonding with the component (B) described later is efficiently enhanced.

  Specific examples of the polyvinyl alcohol resin include Japanese Patent Publication No. 4-52786, Japanese Patent Publication No. 5-67432, Japanese Patent Publication No. 7-29479, Japanese Patent No. 2537827, Japanese Patent Publication No. 7-57553, Japanese Patent No. 2502998, and Japanese Patent No. 2502998. 3053231, JP 63-176173, JP 2604367, JP 7-276787, JP 9-207425, JP 11-58941, JP 2000-135858, JP 2001-205924. JP-A-2001-287444, JP-A-62-278080, JP-A-9-39373, JP-A-2750433, JP-A-2000-158801, JP-A-2001-213, JP-A-2001-328345, JP-A-8 -324105, JP-A-11-348417, etc. And the like.

  When the polyvinyl alcohol-based resin is used in combination with the other water-soluble resin described above, the amount of polyvinyl alcohol in the total mass of the water-soluble resin is preferably 90% by mass or more, and 95% by mass or more. Is more preferable.

  The number average polymerization degree of the polyvinyl alcohol (hereinafter also referred to as “PVA”) is preferably 1800 or more, more preferably 2000 or more, from the viewpoint of preventing cracking of the coating film. For the purpose of improving the dispersibility of the component (B) and the metal oxide particles (C) having a number average particle diameter of 1 nm to 400 nm described later, PVA having a polymerization degree of less than 1800 may be used in combination with PVA having a polymerization degree of 1800 or more. preferable. In that case, the addition amount of PVA having a polymerization degree of less than 1800 is preferably 5% by mass or less, more preferably 1% by mass or less, with respect to the component (C) or the component (B), from the viewpoint of the weather resistance of the coating film. is there. When PVA having a polymerization degree of less than 1800 is added in excess of 5% by mass, the weather resistance of the coating film may be lowered.

  In the present embodiment, the number average polymerization degree of polyvinyl alcohol can be measured by GPC (gel permeation chromatography).

  As the water-soluble resin (A), from the viewpoint of the viscosity of the coating composition, PVA having a saponification degree of 88% or more is preferable, and PVA having a saponification degree of 95% or more is particularly preferable. When the degree of saponification of PVA is in the above range, the water content in the coating composition is preferably 10% by mass or more, more preferably 50% by mass or more, and further preferably 75% by mass or more. When the water content in the coating composition is less than 10%, PVA having a saponification degree of less than 88% is preferably used from the viewpoint of suppressing whitening of the functional coating film obtained by precipitation. Is more preferable.

  Among the polyvinyl alcohol resins, silanol-modified polyvinyl alcohol having a silanol group in the main chain or side chain of polyvinyl alcohol is particularly preferable. The weather resistance of the coating film is improved by the condensation reaction between the silanol group of the water-soluble resin (A) and the functional group of the component (B) or component (C). Particularly preferred are those that dissolve in water under acidic conditions. An example of such a PVA is R polymer “R-1130” (manufactured by Kuraray Co., Ltd.).

  The silanol-modified polyvinyl alcohol is a method of introducing silicon by post-modification using polyvinyl alcohol or a modified polyvinyl acetate containing a carboxyl group or a hydroxyl group using a silylating agent, or a vinyl ester and a silicon-containing polymerizable monomer. Is obtained by a method of saponifying the obtained copolymer. These are disclosed in JP-A-58-59203, JP-A-58-65096, JP-A-58-164604, and the like.

<(B) Hydrolyzable silicon-containing compound>
As the hydrolyzable silicon-containing compound used as the component (B), a hydrolyzable silicon-containing compound (b1) represented by the following formula (1) and a hydrolyzable silicon-containing compound represented by the following formula (2) One or more selected from the group consisting of (b2) and a hydrolyzable silicon-containing compound (b3) represented by the following formula (3) can be used.

Here, in Formula (1), R ¹ may have a hydrogen atom, or a halogen group, a hydroxy group, a mercapto group, an amino group, a (meth) acryloyl group, or an epoxy group, which has 1 to 10 carbon atoms. An alkyl group, an alkenyl group, an alkynyl group or an aryl group. X represents a hydrolyzable group, and n is an integer of 0 to 3. The hydrolyzable group is not particularly limited as long as it is a group that generates a hydroxyl group by hydrolysis, and examples thereof include a halogen atom, an alkoxy group, an acyloxy group, an amino group, a phenoxy group, and an oxime group.

Here, in formula (2), X represents a hydrolyzable group, and R ² represents an alkylene group having 1 to 6 carbon atoms or a phenylene group. p is 0 or 1.

Here, in Formula (3), R < ³ > shows a C1-C6 alkyl group. q is an integer of 2-8.

  Specific examples of the hydrolyzable silicon-containing compounds (b1) and (b2) include tetramethoxysilane, tetraethoxysilane, tetra (n-propoxy) silane, tetra (i-propoxy) silane, and tetra (n-butoxy) silane. , Tetra (i-butoxy) silane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, trimethoxysilane, triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane , Propyltrimethoxysilane, propyltriethoxysilane, isobutyltriethoxysilane, cyclohexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethoxysilane, diethoxysilane, methyldimethoxy Silane, methyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, bis (trimethoxysilyl) methane, bis (triethoxysilyl) methane, bis (triphenoxysilyl) methane, bis (trimethoxysilyl) ethane, bis ( Triethoxysilyl) ethane, bis (triphenoxysilyl) ethane, 1,3-bis (trimethoxysilyl) propane, 1,3-bis (triethoxysilyl) propane, 1,3-bis (triphenoxysilyl) propane, 1,4-bis (trimethoxysilyl) benzene, 1,4-bis (triethoxysilyl) benzene, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3- Hydroxypropyl triethoxy Silane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acrylic Roxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, tetraacetoxysilane, tetrakis (trichloroacetoxy) silane, tetrakis (trifluoroacetoxy) silane, triacetoxysilane, tris (trichloro Acetoxy) silane, tris (trifluoroacetoxy) silane, methyltriacetoxysilane, methyltris (trichloroacetoxy) silane, tetrachlorosilane, teto Labromosilane, tetrafluorosilane, trichlorosilane, tribromosilane, trifluorosilane, methyltrichlorosilane, methyltribromosilane, methyltrifluorosilane, tetrakis (methylethylketoxime) silane, tris (methylethylketoxime) silane, methyltris (methylethylketoxime) Silane, phenyltris (methylethylketoxime) silane, bis (methylethylketoxime) silane, methylbis (methylethylketoxime) silane, hexamethyldisilazane, hexamethylcyclotrisilazane, bis (dimethylamino) dimethylsilane, bis (diethylamino) dimethylsilane, Examples thereof include bis (dimethylamino) methylsilane and bis (diethylamino) methylsilane. These may be used alone or in combination of two or more.

  Specific examples of the hydrolyzable silicon-containing compound (b3) represented by the formula (3) include a partial hydrolysis condensate of tetramethoxysilane (for example, trade name “M silicate 51” manufactured by Tama Chemical Industry Co., Ltd., Colcoat). Trade name “MSI51” manufactured by Mitsubishi Chemical Corporation, “MS51” and “MS56” manufactured by Mitsubishi Chemical Corporation), partially hydrolyzed condensate of tetraethoxysilane (trade names “Silicate 35” manufactured by Tama Chemical Industries, Ltd.), “silicate” 45 ”, trade names“ ESI40 ”and“ ESI48 ”manufactured by Colcoat Co.), a co-hydrolyzed condensate of tetramethoxysilane and tetraethoxysilane (trade name“ FR-3 ”manufactured by Tama Chemical Industries, Ltd., Colcoat) The product name “EMSi48” manufactured by the company) and the like. These may be used alone or in combination of two or more.

  The content of the component (B) in the coating composition is preferably 1 to 99% by mass, more preferably 20 to 95% by mass, and further preferably 30 to 80% by mass.

The mass ratio of the component (A) to the component (B) ((A) / (B)) is preferably 80/20 to 1/99, more preferably 35/65 to 1/99, from the viewpoint of film formability. Furthermore, 26/74 to 1/99 is preferable.
<(C) Metal oxide particles having a number average particle diameter of 1 nm to 400 nm>
The coating composition used in the present embodiment preferably contains (C) component: metal oxide particles having a number average particle diameter of 1 nm to 400 nm. Thereby, it can be set as the coating film with high transparency and hydrophilicity.

  The particle size of the component (C) means the number average particle size (may be a mixture of primary particles and secondary particles, or only one of primary particles and secondary particles). The thickness is 1 nm to 400 nm, preferably 1 nm to 100 nm, more preferably 3 nm to 80 nm, and still more preferably 5 nm to 50 nm. (C) By making the number average particle diameter of a component into the said range, it can contribute to optical characteristics etc., such as a coating film and a laminated body obtained. In particular, setting the number average particle diameter to 100 nm or less can greatly improve the light transmittance of the resulting coating film or laminate. The number average particle diameter in the present embodiment (hereinafter, sometimes simply abbreviated as “particle diameter”) is measured according to the method of Examples described later.

  The metal oxide particles used for the component (C) are not particularly limited, and known particles can be used. From the viewpoint of interaction with the later-described component (D), silicon dioxide, aluminum oxide, antimony oxide. One or more selected from the group consisting of titanium oxide, indium oxide, tin oxide, zirconium oxide, lead oxide, iron oxide, calcium silicate, magnesium oxide, niobium oxide, and cerium oxide are preferred. Among these, the group consisting of silicon dioxide (silica), aluminum oxide (alumina), antimony oxide, and complex oxides thereof from the viewpoint of many surface hydroxyl groups and particularly strong interaction with the component (D) described later. 1 or more types selected from are more preferable. When the coating film described later is used, the component (C) having a large number of surface hydroxyl groups can form a continuous phase, so that the hydroxyl group density on the coating film surface increases and the hydrophilicity of the coating itself increases. Oxide particles are more preferred. (C) The metal oxide particle of a component may be used individually by 1 type, and may be used in combination of 2 or more type.

  The form in which the metal oxide particles (C) are present is not particularly limited, and examples thereof include powder, dispersion, and sol. The "dispersion liquid" and "sol" as used herein means that the component (C) is 0.01 to 80% by mass, preferably 0.1 to 50% by mass in water, a hydrophilic organic solvent or a mixed solvent thereof. Means a state of being dispersed as at least one of primary particles or secondary particles.

  Examples of the hydrophilic organic solvent include alcohols such as ethylene glycol, butyl cellosolve, n-propanol, isopropanol, n-butanol, ethanol and methanol; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethers such as tetrahydrofuran and dioxane. Amides such as dimethylacetamide and dimethylformamide; dimethyl sulfoxide and nitrobenzene, and a mixture of two or more thereof.

  In accordance with the properties desired to be imparted to the coating composition or the coating film, among the above components and other components, a suitable one can be selected as the component (C). Examples of the properties that can be imparted to the coating composition or the coating film include antireflection properties, solvent resistance, antistatic properties, heat resistance, hard coat properties, photocatalytic activity, and the like. Depending on the desired properties, it is possible to select suitable components, contents, physical properties such as number average particle diameter, and the like. Furthermore, when it is desired to enhance the effect of specific performance or to impart a plurality of performances to the coating composition, two or more kinds of metal oxide particles can be used in combination as the component (C). Typical examples from such a viewpoint include particles such as (C1) silica, (C2) photocatalyst, and (C3) conductive metal oxide. Hereinafter, these will be described.

  The component (C1) may be silica (so-called silicon dioxide) particles, and its production method is not particularly limited, and may be produced by a precipitation method, a dry method, or the like. It is more preferable that it exists in the state of colloidal silica from a viewpoint of handleability. When the component (C1) is present in the state of colloidal silica, it can be prepared and used by a sol-gel method, and a commercially available product can also be used. When colloidal silica is prepared by the sol-gel method, Werner Stober et al; Colloid and Interface Sci. , 26, 62-69 (1968), Rickey D .; It can be prepared with reference to the method described in Badley et al; Lang muir 6, 792-801 (1990), Color Material Association Journal, 61 [9] 488-493 (1988) and the like.

  Colloidal silica is a dispersion of water or a water-soluble solvent of silica having silicon dioxide as a basic unit, and the number average particle diameter of the silica particles is preferably 1 nm to 400 nm, more preferably 1 nm to 200 nm, and further Preferably they are 1 nm-100 nm, More preferably, they are 5 nm-30 nm. If the number average particle diameter is 1 nm or more, the storage stability of the coating film and the coating composition described later is better, and if it is 100 nm or less, the transparency of the coating film becomes better. Colloidal silica having silica particles with a particle size in the above range can be used in the state of an aqueous dispersion, either acidic or basic, depending on the stable region of the aqueous dispersion of components to be mixed together. The pH can be appropriately selected.

  As the acidic colloidal silica using water as a dispersion medium, for example, commercially available products such as SNOWTEX (trademark) -O, SNOWTEX-OS, SNOWTEX-OL, manufactured by NISSAN CHEMICAL INDUSTRIES, Inc. ) AT-20Q, Clariant Japan clebosol (trademark) 20H12, clebosol 30CAL25 and the like.

  Examples of basic colloidal silica include silica stabilized by the addition of alkali metal ions, ammonium ions or amines. More specifically, as a commercial product, Snowtex-20, Snowtex-30, Snowtex-C, Snowtex-C30, Snowtex-CM40, Snowtex-N, Snowtex-N30, manufactured by Nissan Chemical Industries, Ltd. Snowtex-K, Snowtex-XL, Snowtex-YL, Snowtex-ZL, Snowtex PS-M, Snowtex PS-L, etc., Adelite AT-20, Adelite AT-30, Adelite made by Asahi Denka Kogyo Co., Ltd. AT-20N, Adelite AT-30N, Adelite AT-20A, Adelite AT-30A, Adelite AT-40, Adelite AT-50, etc., Clariant Japan Clevozol 30R9, Clevozol 30R50, Crevozol 50R50, DuPont Ludox ( quotient ) HS-40, Ludox HS-30, Ludox LS, include Ludox SM-30 and the like.

  As colloidal silica using a water-soluble solvent as a dispersion medium, commercially available products such as MA-ST-M (a methanol dispersion type having a number average particle size of 20 nm to 25 nm), IPA-ST (number average) are available as commercially available products. Isopropyl alcohol dispersion type having a particle diameter of 10 nm to 15 nm), EG-ST (ethylene glycol dispersion type having a number average particle diameter of 10 nm to 15 nm), EG-ST-ZL (ethylene glycol dispersion having a number average particle diameter of 70 nm to 100 nm) Type), NPC-ST (ethylene glycol monopropyl ether dispersion type having a number average particle diameter of 10 nm to 15 nm), and the like.

  Colloidal silica may be used individually by 1 type, and may be used in combination of 2 or more type. When the metal oxide particles of component (C) contain silica particles in colloidal silica as the main component, alumina, sodium aluminate or the like may be contained as a minor component. In addition, an inorganic base (such as sodium hydroxide, potassium hydroxide, lithium hydroxide, or ammonia) or an organic base (such as tetramethylammonium) may coexist in the colloidal silica as a stabilizer. Here, the main component refers to a component contained in the metal oxide particles by 50% by mass or more, preferably 70% by mass or more.

  The (C2) component photocatalyst particles refer to particles of a compound that expresses at least one of photocatalytic activity and hydrophilicity by light irradiation (hereinafter sometimes simply referred to as “photocatalyst”). When the component (C) is a particle of a compound that exhibits photocatalytic activity when irradiated with light, the surface of the resulting coating film is excellent in the decomposition activity (organic matter decomposability) and contamination resistance of the contaminating organic substance.

More specifically, as the photocatalyst, for example, TiO ₂ , ZnO, SrTiO ₃ , BaTiO ₃ , BaTiO ₄ , BaTi ₄ O ₉ , K ₂ NbO ₃ , Nb ₂ O ₅ , Fe ₂ O ₃ , Ta ₂ O ₅ , K ₃ Ta ₃ Si ₂ O ₃ , WO ₃ , SnO ₂ , Bi ₂ O ₃ , BiVO ₄ , NiO, Cu ₂ O, RuO ₂ , CeO ₂ , and further selected from the group consisting of Ti, Nb, Ta, and V Layered oxides having at least one element (for example, JP-A-62-274452, JP-A-2-172535, JP-A-7-24329, JP-A-8-89799, JP-A-8-89800) JP, 8-89804, JP-A-8-188061, JP-A-9-248465, JP-A-10-99694, JP-A-10-244165, etc.) It can gel. Among these photocatalysts, TiO ₂ (titanium oxide) is preferable because it is harmless and has excellent chemical stability. As the titanium oxide, any of anatase type, rutile type and brookite type can be used.

  Moreover, from the viewpoint of expressing the antistatic performance and the like of the resulting coating composition, particles of conductive metal oxide (conductive metal oxide) can be used as the component (C3). Examples of such conductive metal oxides include tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), tin oxide, and zinc oxide. From the viewpoint of interaction with the component (D) described later, for example, aluminum oxide, antimony oxide, indium oxide, tin oxide, zirconium oxide, lead oxide, iron oxide, calcium silicate, magnesium oxide, niobium oxide, cerium oxide, etc. Can also be used together.

  The mass ratio of the component (B) to the component (C) ((B) / (C)) is preferably 1/100 to 1000/100, more preferably 10/100 to 200/100, and further 40 / 100-120 / 100. When (B) / (C) is 1/100 or more, the resulting coating film tends to maintain hydrophilicity even under high temperature or high humidity conditions, and (B) / (C) is 1000/100. When it is the following, there is a tendency that the impact resistance when the coating film is formed can be further improved.

  The component (C) preferably contains (C1) component: silica having a number average particle size of 1 nm to 400 nm and (C2) component: a photocatalyst having a number average particle size of 1 nm to 400 nm. The mass ratio ((C1 + C2) / (A)) of the total content of the component (C1) and the component (C2) to the content of the component (A) is 99/1 to 30/70, preferably 99/1 to 50/50, or 99/1 to 88/12. The mass ratio of the content of the component (C1) to the total content of the component (C1) and the component (C2) ((C1) / (C1 + C2)) is 70/100 to 99/100, 85 / More preferably, it is 100-98 / 100. When (C1 + C2) / (A) is less than 30/70, it cannot be said that the weather resistance of the resulting coating film is sufficient, and when it exceeds 99/1, the film formability is not sufficient.

<(D) Polymer particles>
The coating composition used in the present embodiment preferably contains (D) polymer particles. Thereby, functions, such as anti-reflective property of a functional coating film, can be improved. Here, (D) polymer particles refer to polymer particles obtained by polymerizing a monomer component having an unsaturated bond through the intervention of radicals, cations, anions and the like. When the coating composition used for this Embodiment contains the above-mentioned (C) metal oxide particle, it is preferable that the (D) polymer particle exists by being surrounded by the (C) component. (D) The polymer particles may be emulsion particles, dispersion particles or non-uniformly dispersed slurry particles dispersed in a medium.

  The component (D) is preferably emulsion particles. By using emulsion particles, a sea-island structure can be formed by the component (C) and the component (D) when a coating film described later is used. By forming the sea-island structure, the metal oxide particles are localized on the outermost surface of the coating film, and good hydrophilicity can be expressed by hydrophilic groups such as hydroxyl groups of the metal oxide particles. The emulsion particles are not particularly limited, and examples thereof include acrylic emulsion particles, styrene emulsion particles, acrylic styrene emulsion particles, acrylic silicon emulsion particles, silicon emulsion particles, and fluororesin emulsion particles.

  Component (D) is a polymerization stock solution containing (d1) component: hydrolyzable silicon compound, (d2) component: vinyl monomer, (d3) component: emulsifier, and (d4) component: water. Thus, polymer emulsion particles obtained by polymerizing the component (d1) and the component (d2) are more preferable. When the component (D) contains the component (d1) and the component (d2) in a composite state, the (B) hydrolyzable silicon-containing compound adsorbs to the surface relatively stably or between the particles. This is preferable because of crosslinking. As the component (D) thus obtained, a compound in which a hydroxyl group derived from the component (d1) and a polymerization product of the component (d2) are combined by hydrogen bonding or the like can be suitably used.

  Examples of the component (d1) include a compound represented by the following formula (4), a condensation product thereof, a silane coupling agent, and the like.

Here, in the formula (4), W represents an alkoxy group having 1 to 20 carbon atoms, a hydroxyl group, an acetoxy group having 1 to 20 carbon atoms, a halogen atom, a hydrogen atom, an oxime group having 1 to 20 carbon atoms, an enoxy group, an aminoxy Represents at least one group selected from the group consisting of a group and an amide group. R is a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, and an unsubstituted or alkyl group having 1 to 20 carbon atoms or 1 carbon atom. Represents at least one hydrocarbon group selected from the group consisting of an aryl group having 6 to 20 carbon atoms substituted with an alkoxy group of -20 or a halogen atom. x is an integer from 1 to 4, and y is an integer from 0 to 3. Also, x + y = 4.

  The silane coupling agent means a silane derivative in which a functional group having reactivity with an organic substance such as a vinyl polymerizable group, an epoxy group, an amino group, a methacryl group, a mercapto group, or an isocyanate group exists in the molecule.

  Specific examples of the compound represented by the formula (4) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane; Methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, n-butyltrimethoxysilane N-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyltrimethoxysilane, vinyltri Toxisilane, allyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-tri Fluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, -Mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltri Ethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) Atacyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, 3-ureidopropyltrimethoxysila , Trialkoxysilanes such as 3-ureidopropyltriethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane , Diisopropyldimethoxysilane, diisopropyldiethoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di-n-hexyldimethoxy Silane, di-n-hexyldiethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxysilane, di-n-cyclohexyl The Dialkoxysilanes such as toxisilane, di-n-cyclohexyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane; monoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane And the like. These may be used individually by 1 type and may use 2 or more types together.

  As the component (d1), a silicon alkoxide having a phenyl group (for example, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, etc.) can be used. When a silicon alkoxide having a phenyl group is used, the polymerization stability in the presence of water and an emulsifier is good, which is preferable.

  The component (d1) may contain a silane coupling agent having a thiol group or a component (d1-1): a hydrolyzable silicon compound having a vinyl polymerizable group. When these are used as the component (d1), the resulting coating film has good long-term antifouling properties, which is preferable.

  Examples of the silane coupling agent having a thiol group include 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.

  Examples of the component (d1-1) include 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- (meth) ) Vinyl polymerizable properties such as acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, 2-trimethoxysilylethyl vinyl ether Examples thereof include a silane coupling agent having a group.

  These silane coupling agents can generate chemical bonds by copolymerization or chain transfer reaction with the component (d2) described later. For this reason, when a silane coupling agent having a vinyl polymerizable group or a thiol group is used in combination with or combined with the other component (d1) described above, the polymerization product of component (d1) will be described later (d2). The component polymerization products can be complexed by chemical bonding.

  Examples of the “vinyl polymerizable group” in the component (d1-1) include a vinyl group and an allyl group, and among these, a 3- (meth) acryloxypropyl group is preferable.

  The component (d1) may contain a component (d1-2): a cyclic siloxane oligomer. When the component (d1-2) is used, the resulting coating film has better flexibility and is suitable.

  As a cyclic siloxane oligomer, the compound represented by following formula (5) can be illustrated.

Here, in Formula (5), R ′ is a hydrogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, and unsubstituted. Or at least one selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms substituted with a halogen atom. m is an integer, and 2 ≦ m ≦ 20.

  Of these, cyclic dimethylsiloxane oligomers such as octamethylcyclotetrasiloxane are preferred from the viewpoint of reactivity.

  (D1) component mentioned above may be used individually by 1 type, and may use 2 or more types together.

  When a condensation product is used as the component (d1), the condensation product has a polystyrene-equivalent weight average molecular weight (by GPC method) of preferably 200 to 5,000, more preferably 300 to 1,000.

  The mass ratio ((d1) / (D)) of the content of the component (d1) to the content of the component (D) is preferably 0.01 / 100 to 80/100, more preferably from the viewpoint of polymerization stability. Is 0.1 / 100 to 70/100.

  From the viewpoint of polymerization stability, the mass ratio ((d1-1) / (D)) of the content of the component (d1-1) to the content of the component (D) is preferably 0.01 / 100 to 20 /. 100, more preferably 0.5 / 100 to 10/100. The mass ratio ((d1-1) / (d2)) of the content of the component (d1-1) to the content of the component (d2) is preferably 0.1 / 100 to 100 / from the viewpoint of polymerization stability. 100, more preferably 0.5 / 100 to 50/100.

  The mass ratio ((d1-2) / (D)) (mass ratio) of the content of the component (d1-2) to the content of the component (D) is preferably 0.01 / 100 from the viewpoint of hydrophilicity. -20/100, more preferably 0.5 / 100 to 5/100. The mass ratio ((d1-2) / (d2)) of the content of the component (d1-2) to the content of the component (d2) is preferably 0.5 / 100 to 50 / from the viewpoint of polymerization stability. 100, more preferably 1.0 / 100 to 20/100.

  The component (d2) is a vinyl monomer. The component (d2) is preferably a vinyl monomer having at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an amide group, an amino group, and an ether group. By being a vinyl monomer having such a functional group, it is chemically bonded (for example, condensed) with a functional group possessed by another component other than the component (D) (for example, metal oxide particles of the component (C)). Becomes easier and the interaction can be enhanced.

  Specific examples of the hydroxyl group-containing vinyl monomer mentioned as the component (d2) include various kinds such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Hydroxyalkyl (meth) acrylates; various hydroxyl group-containing vinyl ethers such as 2-hydroxyethyl vinyl ether or 4-hydroxybutyl vinyl ether; various hydroxyl group-containing allyl ethers such as 2-hydroxyethyl allyl ether; Monoesters of polyoxyalkylene glycols obtained from various polyether polyols typified by various unsaturated carboxylic acids typified by (meth) acrylic acid; various hydroxyl group-containing monomers described above Adducts with various lactones represented by ε-caprolactone; Adducts with various epoxy group-containing unsaturated monomers typified by glycidyl (meth) acrylate and various acids typified by acetic acid; Adducts of various unsaturated carboxylic acids typified by (meth) acrylic acid and various monoepoxy compounds other than epoxides of α-olefins typified by “Cardura E” (trade name of Shell, Netherlands) Is mentioned.

  Specific examples of the carboxyl group-containing vinyl monomer mentioned as the component (d2) include, for example, (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, crotonic acid, itaconic acid, maleic acid or fumaric acid. Various unsaturated carboxylic acids; unsaturated dicarboxylic acids such as monomethyl itaconate, mono-n-butyl itaconate, monomethyl maleate, mono-n-butyl maleate, monomethyl fumarate, mono-n-butyl fumarate; Monoesters with saturated monohydric alcohols (half esters); Monovinyl esters of various saturated dicarboxylic acids such as monovinyl adipate or monovinyl succinate; succinic anhydride, glutaric anhydride, phthalic anhydride, or tri Absence of various saturated polycarboxylic acids such as merit acid Products of addition reaction between the above-mentioned various hydroxyl group-containing vinyl monomers; monomers obtained by addition reaction of the above-mentioned various carboxyl group-containing monomers with lactones, etc. Can be mentioned.

  Specific examples of the amino group-containing vinyl monomer exemplified as the component (d2) include 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-di-n-propylaminoethyl ( Various tertiary amino group-containing (meth) such as (meth) acrylate, 3-dimethylaminopropyl (meth) acrylate, 4-dimethylaminobutyl (meth) acrylate or N- [2- (meth) acryloyloxy] ethylmorpholine Acrylic acid esters; various tertiary amino group-containing aromatic vinyl monomers such as vinylpyridine, N-vinylcarbazole, N-vinylquinoline; N- (2-dimethylamino) ethyl (meth) acrylamide; N- (2-diethylamino) ethyl (meth) acrylamide, N- ( -Di-n-propylamino) ethyl (meth) acrylamide, N- (3-dimethylamino) propyl (meth) acrylamide, N- (4-dimethylamino) butyl (meth) acrylamide or N- [2- (meth) Acrylamide] Various tertiary amino group-containing (meth) acrylamides such as ethylmorpholine; N- (2-dimethylamino) ethylcrotonic acid amide, N- (2-diethylamino) ethylcrotonic acid amide, N- (2- Various tertiary amino group-containing crotonic acid amides such as di-n-propylamino) ethyl crotonic acid amide, N- (3-dimethylamino) propyl crotonic acid amide or N- (4-dimethylamino) butyl crotonic acid amide 2-dimethylaminoethyl vinyl ether, 2-diethylaminoethyl vinyl Ether, 3-dimethylaminopropyl vinyl ether or various tertiary amino group-containing vinyl ethers such as 4-dimethylaminopyridine butyl vinyl ether.

  Specific examples of the ether group-containing vinyl monomer mentioned as the component (d2) include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene higher fatty acid ester, polyoxyethylene-polyoxypropylene block copolymer Examples thereof include vinyl monomers such as vinyl ethers, allyl ethers or (meth) acrylic acid esters having various polyether chains such as coalesced in the side chain. As the ether group-containing vinyl monomer, a commercially available product can be used. For example, BLEMMER PE-90, PE-200, PE-350, PME-100, PME-200, PME-400, AE-350 (above, Nippon Oil & Fats). Product name), MA-30, MA-50, MA-100, MA-150, RA-1120, RA-2614, RMA-564, RMA-568, RMA-1114, MPG130-MA (above, Japan) Emulsifiers, trade name) and the like. Here, the number of oxyethylene units in the polyoxyethylene chain is preferably 2 to 30. If it is less than 2, the flexibility of the coating film tends to be insufficient, and if it exceeds 30, the coating film becomes soft and tends to be inferior in blocking resistance.

  Specific examples of the amide group-containing vinyl monomer mentioned as the component (d2) include N-alkyl or N-alkylene-substituted (meth) acrylamide. More specifically, for example, N-methylacrylamide, N-methylmethacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N-ethylmethacrylamide N-methyl-N-ethylacrylamide, N-methyl-N-ethylmethacrylamide, N-isopropylacrylamide, Nn-propylacrylamide, N-isopropylmethacrylamide, Nn-propylmethacrylamide, N-methyl- Nn-propylacrylamide, N-methyl-N-isopropylacrylamide, N-acryloylpyrrolidine, N-methacryloylpyrrolidine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylhexahi Loazepine, N-acryloylmorpholine, N-methacryloylmorpholine, N-vinylpyrrolidone, N-vinylcaprolactam, N, N′-methylenebisacrylamide, N, N′-methylenebismethacrylamide, N-vinylacetamide, diacetone acrylamide, Examples include diacetone methacrylamide, N-methylol acrylamide, N-methylol methacrylamide and the like.

  The component (d2) is preferably a vinyl monomer having a secondary amide group, a tertiary amide group, or both from the viewpoint of further improving the hydrogen bondability with other components. In particular, a vinyl monomer having a tertiary amide group is preferable from the viewpoint of hydrogen bonding strength.

  (D2) component mentioned above may be used individually by 1 type, and may use 2 or more types together.

  The mass ratio ((d2) / (D)) of the content of the component (d2) to the content of the component (D) is 0.01 / 100 to 99/100, preferably 0.00. 1/100 to 60/100, more preferably 0.5 / 100 to 50/100.

  The mass ratio ((d2) / (C1)) of the content of the component (d2) to the content of the component (C1) described above is 0.0001 from the viewpoint of hydrogen bondability with the component (C1) and blending stability. / 100 to 90/100, preferably 0.001 / 100 to 50/100, more preferably 0.2 / 1 to 25/100.

  Examples of the component (d3) include acidic emulsifiers such as alkylbenzene sulfonic acid, alkyl sulfonic acid, alkyl sulfosuccinic acid, polyoxyethylene alkyl sulfuric acid, polyoxyethylene alkyl aryl sulfuric acid, polyoxyethylene distyryl phenyl ether sulfonic acid, and acidic emulsifiers. Anionic surfactants such as alkali metal (Li, Na, K, etc.) salts, ammonium salts of acidic emulsifiers, fatty acid soaps; quaternary ammonium salts such as alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate, pyridinium Salt, imidazolinium salt type cationic surfactant; polyoxyethylene alkyl aryl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethyleneoxypropylene block copolymer Rimmer, nonionic surface active agent polyoxyethylene distyryl phenyl ether, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

  As the component (d3), a reaction having a radical polymerizable double bond from the viewpoint of improving the water dispersion stability of the obtained component (D) and improving the long-term antifouling property of the obtained coating film. It is preferable to use a functional emulsifier. Examples of reactive emulsifiers include vinyl monomers having a sulfonic acid group or a sulfonate group, vinyl monomers having a sulfate ester group, and vinyls having nonionic groups such as alkali metal salts, ammonium salts, and polyoxyethylene thereof. Examples thereof include a monomer and a vinyl monomer having a quaternary ammonium salt.

  As a vinyl monomer having a sulfonic acid group or a sulfonate group, for example, it has a radical polymerizable double bond and is partially substituted by a substituent such as an ammonium salt, sodium salt or potassium salt of the sulfonic acid group. A substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkyl ether group having 2 to 4 carbon atoms, a polyalkyl ether group having 2 to 4 carbon atoms, a phenyl group, a naphthyl group, and a succinic acid group. A compound having a group; a vinyl sulfonate compound having a vinyl group to which a substituent is bonded, such as an ammonium salt, a sodium salt or a potassium salt of a sulfonic acid group.

  As the vinyl monomer having a sulfate ester group, for example, it has a radical polymerizable double bond and is partially substituted by a substituent such as ammonium salt, sodium salt or potassium salt of the sulfate ester group. Examples include compounds having a substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkyl ether group having 2 to 4 carbon atoms, a polyalkyl ether group having 2 to 4 carbon atoms, a phenyl group, and a naphthyl group. It is done.

  Specific examples of the compound having a succinic acid group partially substituted with a substituent such as ammonium salt, sodium salt or potassium salt of sulfonic acid group include allyl sulfosuccinate. More specifically, for example, Eleminol JS-2 (trade name, manufactured by Sanyo Kasei Co., Ltd.), Latemul S-120, S-180A or S-180 (trade name, manufactured by Kao Corporation) and the like can be mentioned.

  Specific examples of compounds having an alkyl ether group having 2 to 4 carbon atoms or a polyalkyl ether group having 2 to 4 carbon atoms partially substituted with a substituent such as an ammonium salt, sodium salt or potassium salt of a sulfonic acid group Examples include Aqualon HS-10 or KH-1025 (Daiichi Kogyo Seiyaku Co., Ltd., trade name), Adekaria Soap SE-1025N or SR-1025 (Asahi Denka Kogyo Co., Ltd. trade name), and the like.

  Specific examples of the vinyl monomer having a nonionic group include, for example, α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene (trade name: ADEKA rear soap NE). -20, NE-30, NE-40, etc., manufactured by Asahi Denka Kogyo Co., Ltd., polyoxyethylene alkylpropenyl phenyl ether (trade names: Aqualon RN-10, RN-20, RN-30, RN-50, etc., first Manufactured by Pharmaceutical Industry Co., Ltd.).

  (D3) component mentioned above may be used individually by 1 type, and may use 2 or more types together.

  The amount of component (d3) used is preferably 10 parts by mass or less, more preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of component (D) from the viewpoint of polymerization stability.

  The component (D) is a weight obtained by polymerizing the component (d1) and the component (d2) in the polymerization stock solution containing the components (d1) to (d3) and the component (d4) (that is, water). Preferred are coalesced emulsion particles. The amount of the component (d4) used is preferably 30 to 99.9% by mass as the content in the polymerization stock solution from the viewpoint of polymerization stability.

  In addition to the components (d1) to (d4), various components can be further mixed in the polymerization stock solution. First, it is preferable to further mix (d5) component: (d2) component with another vinyl monomer copolymerizable with the polymerization stock solution. The use of such a component (d5) means that the properties of the polymerization product to be produced (glass transition temperature, molecular weight, hydrogen bonding force, polarity, dispersion stability, weather resistance, hydrolyzable silicon compound as component (d1) From the viewpoint of controlling the compatibility with the polymerization product, etc.).

  Examples of the component (d5) include acrylic acid esters, methacrylic acid esters, aromatic vinyl compounds, vinyl cyanides, epoxy group-containing vinyl monomers, carbonyl group-containing vinyl monomers, anionic vinyl monomers. And a monomer containing a functional group such as

  (D5) component mentioned above may be used individually by 1 type, and may use 2 or more types together.

  (D5) As a ratio for which a component accounts in all the vinyl monomers, Preferably it is 0.001-30 mass%, More preferably, it is the range of 0.05-10 mass%. Use of component (d5) in this range means that glass transition temperature, molecular weight, hydrogen bonding force, polarity, dispersion stability, weather resistance, and (d1) compatibility with the polymerization product of the hydrolyzable silicon compound as component. From the viewpoint of controlling the above and the like.

  A chain transfer agent can be mixed into the polymerization stock solution. Examples of chain transfer agents include alkyl mercaptans such as n-octyl mercaptan, n-dodecyl mercaptan and t-dodecyl mercaptan; aromatic mercaptans such as benzyl mercaptan and dodecyl benzyl mercaptan; thiocarboxylic acids such as thiomalic acid or These salts or alkyl esters thereof, or polythiols, diisopropylxanthogen disulfide, di (methylenetrimethylolpropane) xanthogen disulfide and thioglycol, and allyl compounds such as α-methylstyrene dimer, and the like. These chain transfer agents may be used individually by 1 type, and may use 2 or more types together.

  The amount of the chain transfer agent used is preferably 0.001 to 30 parts by mass, more preferably 0.05 to 10 parts by mass with respect to 100 parts by mass of the total amount of all vinyl monomers. Use of a chain transfer agent in this range is preferred from the viewpoint of polymerization stability.

  Furthermore, a dispersion stabilizer can be mixed in the polymerization stock solution. The dispersion stabilizer is not particularly limited, and for example, various water-soluble oligomers selected from the group consisting of polycarboxylic acids and sulfonates, polyvinyl alcohol, hydroxyethyl cellulose, starch, maleated polybutadiene, maleated alkyd resin, poly Synthetic or natural water-soluble or water-dispersible polymer materials such as acrylic acid (salt), polyacrylamide, water-soluble or water-dispersible acrylic resin and the like can be mentioned. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The amount of the dispersion stabilizer used is preferably 10 parts by mass or less, more preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of the component (D) polymer emulsion particles.

  The polymerization of the polymerization stock solution is preferably carried out in the presence of a polymerization catalyst. Examples of the polymerization catalyst for component (d1) include hydrogen halides such as hydrochloric acid and hydrofluoric acid; carboxylic acids such as acetic acid, trichloroacetic acid, trifluoroacetic acid and lactic acid; sulfonic acids such as sulfuric acid and p-toluenesulfonic acid; alkylbenzene Acidic emulsifiers such as sulfonic acid, alkylsulfonic acid, alkylsulfosuccinic acid, polyoxyethylene alkylsulfuric acid, polyoxyethylene alkylarylsulfuric acid, polyoxyethylene distyrylphenyl ether sulfonic acid; acidic or weakly acidic inorganic salt; phthalic acid, Acidic compounds such as phosphoric acid and nitric acid; sodium hydroxide, potassium hydroxide, sodium methylate, sodium acetate, tetramethylammonium chloride, tetramethylammonium hydroxide, tributylamine, diazabicycloundecene, ethylenediamine , Basic compounds such as diethylenetriamine, ethanolamines, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane; tin compounds such as dibutyltin octylate, dibutyltin dilaurate, etc. Is mentioned. Among these, as a polymerization catalyst for the hydrolyzable silicon compound which is the component (d1), acidic emulsifiers having an action as an emulsifier as well as a polymerization catalyst, particularly alkylbenzenesulfonic acid (dodecylbenzene) having 5 to 30 carbon atoms. Sulfonic acid etc.) are preferred.

  The amount of the component (d1) polymerization catalyst used is preferably 0.01% by mass to 20% by mass with respect to the component (d1) before hydrolysis.

  As the polymerization catalyst for the component (d2), a radical polymerization catalyst that causes radical polymerization by heat or a reducing substance to cause addition polymerization of a vinyl monomer is suitable. Examples of such radical polymerization catalysts include water-soluble or oil-soluble persulfates, peroxides, and azobis compounds, and these are preferred. More specifically, as a radical polymerization catalyst, for example, potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 2,2-azobisisobutyro Nitriles, 2,2-azobis (2-diaminopropane) hydrochloride, 2,2-azobis (2,4-dimethylvaleronitrile) and the like can be mentioned.

  The amount of the component (d2) polymerization catalyst used is preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of the total vinyl monomers. When acceleration of the polymerization rate and low temperature polymerization at 70 ° C. or lower are desired, it is advantageous to use a reducing agent such as sodium bisulfite, ferrous chloride, ascorbate, Rongalite in combination with the radical polymerization catalyst. is there.

  In the present embodiment, the polymerization of the component (d1) and the polymerization of the component (d2) can be carried out separately, but if performed at the same time, a micro organic / inorganic composite by hydrogen bonding or the like is achieved. It is preferable because it is possible.

  As a method for obtaining the component (D), so-called emulsion polymerization in which the (d1) component and the (d2) component are polymerized in the presence of a sufficient amount of water for the emulsifier to form micelles is suitable. As a method of emulsion polymerization, for example, the component (d1) and the component (d2), and further the component (d3) as necessary or in an emulsified state, in a batch or divided or continuously in a reaction vessel. And a method of polymerizing at a reaction temperature of about 30 to 150 ° C. in the presence of a polymerization catalyst, preferably from atmospheric pressure to 10 MPa as necessary. However, if necessary, the polymerization may be carried out at a higher pressure or lower temperature conditions.

  Regarding the blending of each component of the polymerization stock solution, from the viewpoint of polymerization stability, (d1) to (d4) so that the total solid mass is in the range of 0.1 to 70 mass%, preferably 1 to 55 mass%. Each component is preferably blended. The total solid content mass (% by mass) can be obtained based on the following formula (I) by obtaining a dry mass obtained by putting the component (D) in an oven heated to 100 ° C. for 2 hours and drying it.

In carrying out emulsion polymerization, it is preferable to use a seed polymerization method from the viewpoint of appropriately growing or controlling the particle diameter of the component (D) to be obtained. The seed polymerization method is a method in which emulsion particles (seed particles) are previously present in an aqueous phase for polymerization. The pH in the polymerization system when performing the seed polymerization method is preferably 1.0 to 10.0, and more preferably 1.0 to 6.0. The pH can be adjusted using a pH buffer such as disodium phosphate, borax, sodium hydrogen carbonate, ammonia or the like.

  As a method for obtaining the component (D), in the presence of the components (d3) and (d4) necessary for polymerizing the component (d1), the components (d1) and (d2) are optionally added in the presence of a solvent. A method of adding water after polymerization until the polymerization product becomes emulsion particles can also be applied.

  The component (D) has a core / shell structure including a core layer and one or more shell layers covering the core layer from the viewpoint of improving the substrate adhesion of the obtained coating film. It is preferable. As a method for forming the core / shell structure, multistage emulsion polymerization in which emulsion polymerization is performed in multiple stages is very useful. The core / shell structure can be observed, for example, by morphological observation using a transmission electron microscope or the like, or analysis by viscoelasticity measurement.

  The component (D) is a polymer emulsion particle obtained by polymerizing the component (d1) and the component (d2) in the polymerization stock solution containing the seed particles that form the core layer. More preferably, the particles are obtained by polymerizing at least one component selected from the group consisting of the component (d1), the component (d2), and the component (d5). Again, multi-stage emulsion polymerization is useful.

  Specifically, the multistage emulsion polymerization is, for example, at least selected from the group consisting of (d1) component, (d2) component and (d5) component in the presence of (d3) component and (d4) component as the first step. One or more components are polymerized to form seed particles, and as a second step, a polymerization stock solution containing (d1) component and (d2) component, and (d5) component as necessary, in the presence of the seed particles. Is added for polymerization (two-stage polymerization method). When carrying out multi-stage emulsion polymerization of three or more stages, for example, as the third stage, polymerization may be carried out by adding a polymerization stock solution further containing the component (d1) and the component (d2) and, if necessary, the component (d5). it can. Such a method is also suitable from the viewpoint of polymerization stability.

  When employing the two-stage polymerization method, the mass ratio of the solid content mass (M1) in the polymerization stock solution used in the first stage to the solid content mass (M2) in the polymerization stock solution added in the second stage ( (M1) / (M2)) is preferably 9/1 to 1/9, more preferably 8/2 to 2/8, from the viewpoint of polymerization stability.

  Further, as the core / shell structure, from the viewpoint of polymerization stability, the particle size distribution (volume average particle size / number average particle size) of the seed particles does not change greatly, and the particle size is increased by the second stage polymerization. It is preferred to have an increased structure. The volume average particle diameter can be measured in the same manner as the number average particle diameter.

  The polymer emulsion particles (D) have a mass ratio ((d2) / (d1)) of the content of the component (d2) to the content of the component (d1) in the core layer is 0.01 / 1 to 1. / 1 is preferable. In the outermost layer of the shell layer, the mass ratio of the content of the component (d2) to the content of the component (d1) ((d2) / (d1)) is preferably 0.01 / 1 to 10/1. . In the core layer, when the mass ratio ((d2) / (d1)) is 0.01 / 1 or more, the polymerization stability tends to be more excellent, and when it is 1/1 or less, durability and flexibility are obtained. Further improve. Further, by setting the mass ratio ((d2) / (d1)) to 0.01 / 1 or more in the outermost layer of the shell layer, the interaction with the component (C) can be increased, and 10/1 or less. By doing so, the interaction can be moderately suppressed, and sufficient stability tends to be obtained.

  The glass transition temperature (Tg) of the core layer of the core / shell structure is preferably 0 ° C. or lower. In this case, since a coating film with more excellent flexibility at room temperature can be obtained, it is possible to form a protective member for a solar cell that is less prone to cracks and the like, which is preferable. In the present embodiment, Tg can be measured with a differential scanning calorimeter (DSC).

  It is preferable that the content rate of the aqueous phase component of (D) component is 15 mass% or less. The content of the aqueous phase component (D) is represented by the following formula (II). By setting the water phase component of the component (D) to 15% by mass or less, the obtained coating film is excellent in transparency and hydrophilicity, and can maintain excellent hydrophilicity even at high temperatures.

In formula (II), the dry mass of the filtrate refers to the mass of the residue after drying the filtrate at 105 ° C. for 1 hour.

  The content of the aqueous phase component in component (D) is preferably 15% by mass or less, more preferably 10% by mass or less, whereby the resulting coating film is excellent in transparency and hydrophilicity, and only at high temperatures. In addition, excellent hydrophilicity can be maintained even under high humidity, and even under high temperature and high humidity. Although the minimum of content of the water phase component in (D) component is not specifically limited, For example, it is 0 mass%.

  The number average particle diameter of the component (D) is preferably 10 nm to 800 nm. The coating film obtained by adjusting the number average particle diameter of the component (D) to such a range and forming the coating composition in combination with the component (C) having the number average particle diameter of 1 nm to 400 nm as described above, Weather resistance and contamination resistance are further improved. From the viewpoint of improving the transparency of the resulting coating film, the number average particle diameter of the component (D) is more preferably 10 nm to 100 nm. In addition, in the form of this invention, a number average particle diameter can be measured by the method as described in the below-mentioned Example.

  The mass ratio ((C) / (D)) of the component (C) to the component (D) is preferably 50/100 to 10000/100, more preferably 110, from the viewpoints of hydrophilicity and film formability. / 100 to 1000/100, more preferably 150/100 to 300/100. By setting it as this ratio, the hydrophilic property and antireflection property of the coating film obtained can be improved.

  The ratio ((SC) / (SD)) of the surface area (SC) of the component (C) and the surface area (SD) of the component (D) is preferably in the range of 0.001 to 1000. The surface area of each component can be calculated from the particle diameter, the mass, and the specific gravity of the component (C) and the component (D), assuming that the particle shape is a true sphere.

  The mass ratio of the component (D) to the component (B) ((D) / (B)) is preferably 80/20 or more from the viewpoint of the hydrophilicity of the resulting coating film, and from the viewpoint of crack resistance and wettability. To 1/99 or less. More preferably, 35/65 to 1/99, and more preferably 26/74 to 1/99.

  When the coating composition includes (D) polymer particles, the pH of the coating composition is preferably 7 or less. More preferably, it is 4 or less, More preferably, it is 3 or less. When pH is 7 or less, partial hydrolysis of component (B) tends to proceed quickly and stably. As a result, the condensation between the partially hydrolyzed (B) components effectively proceeds in the condensation and curing stages after coating on the substrate, and the (C) component, (D) component, Since chemical bonding proceeds in a well-balanced manner, it becomes possible to exhibit an antireflection effect and coating strength while maintaining the hydrophilicity of the obtained functional coating.

  The pH of the coating composition can be adjusted by adding the component (B) and then slowly adding the acid catalyst while sequentially checking the pH with a pH meter. The amount of the acid catalyst used and the concentration of the acid catalyst can be appropriately adjusted depending on the concentration of the component (B) in the coating composition. In order for the component (B) to be partially hydrolyzed stably, the concentration of the acid catalyst is preferably 1% by mass or less, preferably 0.1% by mass or less. By setting it as 1 mass% or less, it is possible to suppress local hydrolysis at the time of compounding and to suppress aggregation of the coating composition.

  Examples of the acid catalyst include hydrogen halides such as hydrochloric acid and hydrofluoric acid, carboxylic acids such as acetic acid, trichloroacetic acid, trifluoroacetic acid, and lactic acid, sulfonic acids such as sulfuric acid and p-toluenesulfonic acid, alkylbenzene sulfonic acid, and alkyl sulfonic acid. Acid emulsifiers such as alkylsulfosuccinic acid, polyoxyethylene alkylsulfuric acid, polyoxyethylene alkylarylsulfuric acid, polyoxyethylene distyrylphenyl ether sulfonic acid, acidic or weakly acidic inorganic salts, phthalic acid, phosphoric acid, nitric acid Acid compounds and the like. Among these, acidic emulsifiers, particularly linear alkylbenzenesulfonic acid branched alkylbenzenesulfonic acids having 5 to 30 carbon atoms, such as linear dodecylbenzenesulfonic acid, branched dodecylbenzenesulfonic acid and the like are preferable. Two or more of these may be used in combination.

<Other additives>
In the present embodiment, in addition to the above-described components, additive components that are usually added to and blended with paints and molding resins, such as light stabilizers, ultraviolet absorbers, and thickeners, depending on the application and method of use. Agent, leveling agent, thixotropic agent, antifoaming agent, freezing stabilizer, matting agent, crosslinking reaction catalyst, pigment, curing catalyst, crosslinking agent, filler, anti-skinning agent, dispersing agent, wetting agent, antioxidant UV absorbers, rheology control agents, film forming aids, rust preventives, dyes, plasticizers, lubricants, reducing agents, antiseptics, antifungal agents, deodorants, anti-yellowing agents, antistatic agents or A charge adjusting agent or the like can be selected or combined depending on the purpose.

  As the light stabilizer, for example, a hindered amine light stabilizer is preferably used. Among these, a radical polymerizable light stabilizer having a radical polymerizable double bond in the molecule is preferable. As an ultraviolet absorber, an organic type ultraviolet absorber can be mentioned, for example. Examples of such organic ultraviolet absorbers include benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and triazine ultraviolet absorbers. Among these, it is preferable to use a radical polymerizable ultraviolet absorber having a radical polymerizable double bond in the molecule. Moreover, a benzotriazole type ultraviolet absorber and a triazine type ultraviolet absorber having high ultraviolet absorbing ability are preferable.

  The light stabilizer is preferably used in combination with an organic ultraviolet absorber. Using both together can contribute to improving the weather resistance of the resulting coating film.

  A hydrophilic solvent can be added to the coating composition for the purpose of controlling the voids of the formed coating film. As hydrophilic solvents, ethylene glycol, butyl cellosolve, alcohols such as n-propanol, isopropanol, n-butanol, ethanol and methanol; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethers such as tetrahydrofuran and dioxane; dimethylacetamide And amides such as dimethylformamide; dimethyl sulfoxide and nitrobenzene, and mixtures of two or more thereof. In particular, a solvent having a high solubility in water and a boiling point of 200 ° C. or lower is preferable. In addition to water solubility, solubility parameters can also be used as an indicator of solubility. The solubility parameter is preferably 10 or more. As such a hydrophilic solvent, methanol, ethanol, propanol, isopropanol, butanol, and ethylene glycol are preferable.

  The content of the hydrophilic solvent is preferably 1 to 90% by mass, more preferably 3 to 40% by mass, and further preferably 5 to 20% by mass with respect to the entire coating composition. .

[Method for producing functional coating film]
In the manufacturing method of the functional coating film of this Embodiment, the said coating composition is apply | coated on a base material. As a method for coating, known methods such as dip coating, flow coating, roll coating, spin coating, spray coating, and brush coating can be used.

  After application, in a basic atmosphere, for example, in an atmosphere containing a volatile basic substance, by proceeding with condensation and curing, antireflection properties, that is, void formation and coating strength, while maintaining hydrophilicity Can be expressed.

  Examples of the volatile basic substance used in the present embodiment include ammonia, primary amine, secondary amine, tertiary amine and the like. For example, methylamine, ethylamine, diethylamine, trimethylamine, propylamine, isopropylamine, diisopropylamine, butylamine, isobutylamine, ethanolamine, diethanolamine, triethanolamine, propanolamine, diisopropanolamine, pyridine, piperidine, ethylenediamine, morpholine, etc. is there. In particular, amines having a boiling point of −40 ° C. to 90 ° C. are preferable. For example, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, diisopropylamine, butylamine, isobutylamine and the like. More preferred is ammonia from the viewpoint of volatility and safety. These may be used alone or in combination of two or more.

  The holding time in a basic atmosphere, for example, in an atmosphere of a volatile basic substance, can be appropriately selected depending on the temperature used and the required hardness, but is preferably 0.1 to 24 hours, and more preferably 0.5. -12 hours is preferable from the balance between productivity and condensation rate.

[Functional coating film]
The functional coating film of this Embodiment is obtained by the above-mentioned manufacturing method. The functional coating film of the present embodiment obtained by the above-described production method is excellent in hydrophilicity, antireflection property and pencil hardness, and is excellent in crack resistance during thick film formation.

  The functional coating film of the present embodiment preferably has a surface water contact angle at 23 ° C. of 30 degrees or less, more preferably 20 degrees or less, and even more preferably 10 degrees or less. When the surface water contact angle at 23 ° C. is within the above range, the hydrophilicity of the functional coating film is excellent.

  Furthermore, the water contact angle of the coating film surface after the high temperature and high humidity test that is allowed to stand for 24 hours at 90 ° C. and 90% humidity is preferably 30 degrees or less, more preferably 20 degrees or less, More preferably, it is 10 degrees or less.

  In the present embodiment, the water contact angle on the surface of the coating film is measured by the method described in Examples described later.

  Moreover, in this Embodiment, the control method of the temperature and humidity used by a test can use a well-known high temperature / humidity test machine, for example, SH-661 by ESPEC. Alternatively, distilled water can be placed in a sealed container, and the sealed container can be heated at a predetermined temperature to form saturated steam and used for evaluation.

  The antireflection property of the functional coating film of the present embodiment is preferably 0.5% or more, more preferably 0.8% or more, and further preferably 1.5% or more. The antireflection property is measured by the method described in Examples described later.

  It is preferable that the pencil hardness of the surface of the functional coating film of this Embodiment is F or more. The pencil hardness is measured by the method described in Examples described later.

  The maximum coating film thickness of the functional coating film of the present embodiment is preferably 300 nm or more, more preferably 800 nm or more, and further preferably 1200 nm or more. When the maximum coating film thickness is within the above range, the crack resistance of the coating film is good. The said maximum coating film thickness is measured by the method as described in the Example mentioned later.

<Energy conversion device member>
The functional coating film of this Embodiment can be used suitably as a coating layer of the part for energy converters. Examples of the energy conversion device include a power generation device using sunlight. As an energy member, the member which can be used for the electric power generation using sunlight, for example is said, More specifically, the member used for a solar cell module, the member used for a solar thermal power generation system, etc. are mentioned. Especially, it can use suitably for the protection member of a solar cell module, or the protection member of a light reflection mirror. More specifically, a cover glass that is a protective member on the surface of the solar cell module, a back sheet that is a protective member on the back surface, a sealing material, a formwork such as an aluminum frame, a Fresnel lens of a concentrating solar cell, solar thermal power generation It can be used as a protective member such as a light reflecting mirror used in the above.

  In particular, the functional coating film of the present embodiment is suitable as a protective member for a solar cell module. For example, when a large-scale solar cell module is installed and used in a desert, etc., sand that has been soared by the wind adheres to the protective member of the solar cell module, so that the surface of the member is damaged, transparency or antifouling property There arises a problem that the effect of the decrease. However, the functional coating film of the present embodiment is excellent in antifouling property, transparency, hydrophilicity, durability (impact resistance), and can adhere to the surface even under high temperature and high humidity, so that it adheres. Sand and dust can be easily washed away with rainwater.

  The member of this Embodiment contains the above-mentioned functional coating film. Examples of the member include a solar cell module and a reflector device.

<Solar cell module>
The solar cell module of the present embodiment includes the above-described functional coating film.

  The solar cell module of the present embodiment can include the functional coating film described above as, for example, a coating layer for a protective member (hereinafter sometimes simply referred to as a protective member). FIG. 1 is a simplified cross-sectional view of one embodiment of a solar cell module. The solar cell module 2 includes a protection member 20, a back sheet 22 disposed to face the protection member 20, and a power generation element 24 disposed between the protection member 20 and the back sheet 22. . Further, the power generating element 24 is sealed with a sealing material 26. In the solar cell module 2, sunlight L enters from the protective member 20 side and reaches the power generation element 24.

  The protection member 20 is a protection member that protects the power generation element 24 and the like. In the protective member 20, the functional coating film 204 of the present embodiment is formed on the surface of the substrate. In this case, the protection member 20 functions as a light-transmitting substrate that transmits sunlight. And it is preferable to use the protection member 20 so that the surface in which the said functional coating film 204 was formed may become the surface side of the solar cell module 2. FIG.

  The protective member 20 preferably has performance for ensuring long-term reliability in outdoor exposure of the solar cell module 2 including weather resistance, water repellency, contamination resistance, and mechanical strength. Moreover, in order to utilize sunlight effectively, it is preferable that it is a highly transparent member with a small optical loss. The material of the substrate 202 is not particularly limited, and specifically, a glass substrate; a resin film made of a polyester resin, a fluororesin, an acrylic resin, a cyclic olefin (co) polymer, an ethylene-vinyl acetate copolymer, or the like Among these, a glass substrate is more preferable from the viewpoints of weather resistance, impact resistance, and cost balance.

  When a glass substrate is used, the total light transmittance of light having a wavelength of 350 to 1400 nm is preferably 80% or more, more preferably 90% or more. As such a glass substrate, it is common to use a white plate glass with little absorption in the infrared region, but even a blue plate glass usually has little influence on the output characteristics of the solar cell module if the thickness is 3 mm or less. . Further, tempered glass can be obtained by heat treatment to increase the mechanical strength of the glass substrate, but float plate glass without heat treatment may be used.

  As the resin film, a polyester resin is preferable from the viewpoint of transparency, strength, cost, and the like, and a polyethylene terephthalate resin is more preferable. A fluororesin having particularly good weather resistance is also preferably used. Specifically, tetrafluoroethylene-ethylene copolymer (ETFE), polyvinyl fluoride resin (PVF), polyvinylidene fluoride resin (PVDF), polytetrafluoroethylene resin (TFE), tetrafluoroethylene-6 Examples thereof include a fluorinated propylene copolymer (FEP) and a poly (trifluorotrifluoroethylene resin) (CTFE). Polyvinylidene fluoride resin is preferable from the viewpoint of weather resistance, but tetrafluoroethylene-ethylene copolymer is preferable from the viewpoint of achieving both weather resistance and mechanical strength.

  As the functional coating film 204, the above-described functional coating film can be suitably used. The method described above can also be used for the method of forming the functional coating film 204 on the substrate 202.

  Although there is no limitation in particular as the back sheet | seat 22, since it is located in the outermost layer of a solar cell module, it is preferable to have various characteristics, such as a weather resistance and mechanical strength similarly to the above-mentioned protective member 20. Therefore, you may comprise a back seat | sheet with the material similar to the protection member 20. FIG. That is, the above-mentioned various materials that can be used in the protective member 20 (particularly the base material 202) can also be used in the backsheet. In particular, a polyester resin and a glass substrate can be preferably used, and among these, a polyethylene terephthalate resin (PET) is more preferable from the viewpoint of weather resistance and cost.

  Since the backsheet 22 does not assume the passage of sunlight, the transparency (translucency) required for the protective member 20 is not necessarily required. Therefore, although not shown, a reinforcing plate may be attached for the purpose of increasing the mechanical strength of the solar cell module 2 and for preventing the distortion and warpage due to temperature change. For example, a steel plate, a plastic plate, an FRP (glass fiber reinforced plastic) plate or the like can be preferably used.

  The backsheet 22 may have a multilayer structure including two or more layers. Examples of the multilayer structure include a structure in which one or more layers of the same component are laminated on both sides of the central layer so as to be symmetrical with respect to the central layer. As what has such a structure, PET / alumina vapor deposition PET / PET, PVF (brand name: Tedlar) / PET / PVF, PET / AL foil / PET etc. are mentioned, for example.

  The power generation element 24 is not particularly limited as long as it can generate power using the photovoltaic effect of the semiconductor. For example, silicon (single crystal system, polycrystalline system, amorphous system), compound semiconductor (3- Group 5, 2-6, etc.) can be used, and among these, polycrystalline silicon is preferred from the viewpoint of balance between power generation performance and cost.

  The encapsulant 26 may be any member that can encapsulate the power generating element 24, and the type thereof is not particularly limited. For example, a resin encapsulating sheet containing a resin such as ethylene-vinyl acetate copolymer (EVA) is used. Can be mentioned. By heat-melting such a resin sealing sheet, the resin sealing sheet can be in close contact with the power generation element 24 or the like to be sealed and sealed. By using such a sealing material, creep of the power generation element can be prevented, and excellent adhesiveness to the protective member 20 and the backsheet 22 can be exhibited.

  It does not specifically limit as a manufacturing method of a solar cell module, A well-known method is also employable. For example, the protective member 20 / the sealing material 26 / the power generation element 24 / the sealing material 26 / the back sheet 22 are stacked in this order, and are vacuum-laminated using a vacuum laminator at 150 ° C. for 15 minutes.

  Although the thickness of each member of the solar cell module 2 is not particularly limited, the thickness of the protective member 20 is preferably 3 mm or more from the viewpoint of weather resistance and impact resistance, and the thickness of the back sheet 22 is from the viewpoint of insulation. To 75 μm or more is preferable, the thickness of the power generation element 24 is preferably 140 μm to 250 μm from the viewpoint of balance between power generation performance and cost, and the thickness of the sealing material 26 is 250 μm or more from the viewpoint of cushioning and sealing properties. preferable.

<Reflector device>
The reflector apparatus of this Embodiment contains the above-mentioned functional coating film.

  FIG. 2 is a schematic perspective view of an example of the reflector device. The reflector device 3 includes a light reflecting mirror 32, a functional coating film 30 of the present embodiment formed on the reflecting surface side of the light reflecting mirror, and a support 34 that supports the reflecting mirror 32. The functional coating film 30 is used as a protective member for the light reflecting mirror 32 (hereinafter sometimes simply referred to as a protective member). The structure of the reflector apparatus 3 is not specifically limited, It can deform | transform into a suitable structure suitably.

<Solar thermal power generation system>
In this Embodiment, it can be set as a solar thermal power generation system provided with the said reflector apparatus and the apparatus which converts the sunlight condensed by this reflector apparatus into an electrical energy. The configuration of the solar thermal power generation system is not particularly limited, and can be appropriately modified into a suitable configuration.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated in more detail, this invention is not limited to a following example. Various physical properties were evaluated by the following methods. In this example, “%” and “part” are based on mass unless otherwise specified.

-Number average particle diameter It diluted with the solvent so that solid content in a sample might be 0.1-20 mass%, and it measured using the wet particle size analyzer (Nikkiso Microtrac UPA-9230).

・ Water contact angle After placing a drop of deionized water on the surface of the sample (coating surface of the coating composition) and leaving it at 23 ° C. for 1 minute, a contact angle measurement device (DM-501 contact angle meter manufactured by Kyowa Interface Science) It measured using.

-Antireflective property The total light transmittance of the sample was measured according to JIS K7105 using the turbidimeter (Nippon Denshoku Industries NDH2000). The antireflection property was determined from the following equation by measuring the total light transmittance (T0) of the base material (blue plate glass) and the total light transmittance (T1) of the base material after coating.

Antireflection (%) = T1 (%)-T0 (%)
-Pencil hardness The pencil hardness of the coating surface was measured using a pencil hardness meter (manufactured by Tester Sangyo Co., Ltd.).

-Maximum coating film thickness After film formation with a spin coater, a good film thickness without microcracks was measured when observed with a microscope (100 times). The thicker the maximum coating film thickness, the better the crack resistance.

(Production Example 1)
Synthesis of Polymer Emulsion Particle (LTX-1) Aqueous Dispersion Into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirrer, 1600 g of ion-exchanged water and 4 g of dodecylbenzenesulfonic acid were added and then stirred. The temperature was warmed to 80 ° C. To this, a mixture of 185 g of dimethyldimethoxysilane and 117 g of phenyltrimethoxysilane was dropped over about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C., and then the temperature in the reaction vessel was 80 ° C. And stirring was continued for about 1 hour. Next, 150 g of butyl acrylate, 30 g of tetraethoxysilane, 145 g of phenyltrimethoxysilane, 1.3 g of 3-methacryloxypropyltrimethoxysilane, 165 g of diethylacrylamide, 3 g of acrylic acid, a reactive emulsifier (trade name “ADEKA” Rear soap SR-1025 ", manufactured by Asahi Denka Co., Ltd., solid content 25% by mass aqueous solution) 13 g, ammonium persulfate 2% by mass aqueous solution 40 g, and ion-exchanged water 1900 g mixed liquid were maintained at a temperature of 80 ° C. The solution was dropped simultaneously over about 2 hours. Further, as heat curing, stirring was continued for about 4 hours while the temperature in the reaction vessel was 80 ° C. Thereafter, the mixture is cooled to room temperature and filtered through a 100-mesh wire mesh to obtain a polymer emulsion particle (LTX-1) aqueous dispersion having a solid content of 14.08% by mass, an aqueous phase component of 8.91% by mass, and a number average particle size of 131 nm. It was.

  The polymer emulsion particle (LTX-1) aqueous dispersion was filtered using an ultrafiltration device to obtain a filtrate containing an aqueous phase component. The obtained filtrate was dip-coated on 5 cm × 5 cm blue plate glass, and then dried at 90 ° C. for 24 hours to obtain a film-like test plate. A drop of deionized water was placed on the film surface of the obtained test plate, and after standing at 23 ° C. for 10 seconds, the initial contact angle was measured and found to be 58 °.

(Examples 1 and 2)
After mixing ethanol and water at the blending amounts shown in Table 1, an aqueous PVA solution was added, and then a partial hydrolysis condensate of tetramethoxysilane ("MS-56" manufactured by Mitsubishi Chemical Corporation) was added at 25 ° C and stirred for 30 minutes. The coating composition thus obtained was dip-coated on a 5 cm square blue plate glass substrate, and then allowed to stand in a Tedlar bag (10 L) containing 28% aqueous ammonia / ethanol (50 g / 50 g). The film was kept for 8 hours to obtain a coating film, and the water contact angle, antireflection performance, pencil hardness, and maximum coating film thickness of the obtained coating film were measured.

(Example 3)
After adding ethanol in the blending amount shown in Table 1, an aqueous PVA solution is added, and water-dispersed colloidal silica having particles with a number average particle size of 8 nm (trade name “Snowtex OS”, manufactured by Nissan Chemical Industries, solid content 20 mass% , Hereinafter also referred to as “ST-OS”) with stirring, followed by coating with partial hydrolysis condensate of tetramethoxysilane (“MS-56” manufactured by Mitsubishi Chemical Corporation) at 25 ° C. and stirring for 30 minutes. The obtained coating composition was dip-coated on a 5 cm square blue plate glass substrate, and then allowed to stand in a Tedlar bag (10 L) containing 28% aqueous ammonia / ethanol (50 g / 50 g), The coating film was obtained by holding for 8 hours, and the water contact angle, antireflection performance, pencil hardness, and maximum coating film thickness of the coating film were measured.

Example 4
After adding ethanol in the blending amount shown in Table 1, an aqueous PVA203 solution is added, and water-dispersed colloidal silica having particles with a number average particle diameter of 8 nm (trade name “Snowtex OS”, manufactured by Nissan Chemical Industries, solid content 20 mass% ) Was added with stirring, and then an aqueous PVA217 solution was gradually added. Next, a partial hydrolysis condensate of tetramethoxysilane (“MS-56” manufactured by Mitsubishi Chemical Corporation) was added at 25 ° C. at a blending amount shown in Table 1 and stirred for 30 minutes to obtain a coating composition. The coating composition is dip-coated on a 5 cm square blue plate glass substrate, then left in a Tedlar bag (10 L) containing 28% aqueous ammonia / ethanol (50 g / 50 g) and kept for 8 hours to obtain a coating film. The water contact angle, antireflection performance, pencil hardness, and maximum coating film thickness of the obtained coating film were measured.

(Example 5)
PVA505 was dissolved in 60% methanol water to prepare a PVA505 solution. After adding ethanol in the blending amount shown in Table 1, the above-prepared PVA505 solution was added, and water-dispersed colloidal silica having a number average particle diameter of 8 nm (trade name “Snowtex OS”, manufactured by Nissan Chemical Industries, solid 20% by weight) was added with stirring. Next, a partial hydrolysis condensate of tetramethoxysilane (“MS-56” manufactured by Mitsubishi Chemical Corporation) was added at 25 ° C. at a blending amount shown in Table 1 and stirred for 30 minutes to obtain a coating composition. The coating composition is dip-coated on a 5 cm square blue plate glass substrate, then left in a Tedlar bag (10 L) containing 28% aqueous ammonia / ethanol (50 g / 50 g) and kept for 8 hours to obtain a coating film. The water contact angle, antireflection performance, pencil hardness, and maximum coating film thickness of the obtained coating film were measured.

(Example 6)
After mixing ethanol and water in the blending amounts shown in Table 1, an aqueous PVA solution was added, and a water-dispersed colloidal silica having a number average particle diameter of 8 nm (trade name “Snowtex OS”, manufactured by Nissan Chemical Industries, solid content 20 mass%) Was added with stirring, and then polymer emulsion particles (LTX-1) were added. Subsequently, tetramethoxysilane partially hydrolyzed condensate (“MS-56” manufactured by Mitsubishi Chemical Co., Ltd.) was added at 25 ° C. and stirred for 30 minutes in the blending amounts shown in Table 1 to obtain a coating composition. The composition was dip-coated on a 5 cm square blue plate glass substrate, then left in a Tedlar bag (10 L) containing 28% aqueous ammonia / ethanol (50 g / 50 g), and held for 8 hours to obtain a coating film. The water contact angle, antireflection performance, pencil hardness, and maximum coating film thickness of the obtained coating film were measured.

(Comparative Example 1)
After mixing ethanol and water with the blending amounts shown in Table 1, tetramethoxysilane partially hydrolyzed condensate ("MS-56" manufactured by Mitsubishi Chemical Corporation) was added at 25 ° C and stirred for 30 minutes to obtain a coating composition. The obtained coating composition was spin-coated on a 5 cm square blue plate glass substrate, then left standing in a Tedlar bag (10 L) containing 28% aqueous ammonia / ethanol (50 g / 50 g) and held for 8 hours. The coating film was measured for water contact angle, antireflection performance, pencil hardness, and maximum coating thickness.

(Comparative Example 2)
After mixing ethanol and water at the blending amounts shown in Table 1, an aqueous PVA solution was added, and then a partial hydrolysis condensate of tetramethoxysilane (“MS-56” manufactured by Mitsubishi Chemical Corporation) was added at 25 ° C. and stirred for 30 minutes. Thus, a coating composition was obtained. The obtained coating composition was dip-coated on a 5 cm square blue plate glass substrate, and then allowed to stand in a Tedlar bag (10 L) containing only air and kept for 8 hours to obtain a coating film. The water contact angle, antireflection performance, pencil hardness, and maximum coating film thickness of the obtained coating film were measured.

  The results of Examples and Comparative Examples are shown in Table 1.

As shown in Table 1, it was confirmed that the coating film of each Example was excellent in hydrophilicity, antireflection property and pencil hardness, and excellent in crack resistance during thick film formation.

  The coating film obtained by the production method of the present invention has excellent hydrophilicity, antireflection properties, pencil hardness, and excellent crack resistance during thick film, so it can be used in various energy production apparatuses such as solar cell modules and solar thermal power generation systems. It can be used as a member or the like, and can be suitably used as a protective member for solar cells having good sunlight permeability and light condensing property, a light reflecting mirror member for solar thermal power generation, and the like.

2 ... Solar cell module 20 ... Protective member 22 ... Back sheet 24 ... Power generation element 26 ... Sealing material 202 ... Base 204 ... Coating film 3 ... Reflector device 30 ... Laminated body (protective member)
32 ... Light reflecting mirror 34 ... Support

Claims (10)

  A method for producing a functional coating film comprising a step of condensing and curing in a basic atmosphere after a coating composition containing (A) a water-soluble resin and (B) a hydrolyzable silicon-containing compound is applied on a substrate. .   The method for producing a functional coating film according to claim 1, wherein the component (A) contains a polyvinyl alcohol resin.   The method for producing a functional coating film according to claim 1 or 2, wherein the coating composition further comprises (C) metal oxide particles having a number average particle diameter of 1 nm to 400 nm.   The method for producing a functional coating film according to any one of claims 1 to 3, wherein the coating composition further comprises (D) polymer particles.   The functional coating film obtained by the manufacturing method as described in any one of Claims 1-4.   The functional coating film according to claim 5, which is for a solar cell module protective member.   The functional coating film according to claim 5, which is used for a protective member for a light reflecting mirror.   A member comprising the functional coating film according to claim 5.   The solar cell module containing the functional coating film of Claim 5.   The reflector apparatus containing the functional coating film of Claim 5.