JP2009286859A - Coating composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating composition having excellent weather resistance and antifouling properties and exhibiting good protective properties for a resin base material. <P>SOLUTION: The coating composition comprises single metal compound particles with a particle diameter of 1-400 nm (a component A), polymer emulsion particles with a particle diameter of 10-800 nm (a component B), and a complex of a plurality of metal compounds (a component C). The component B consists of polymer emulsion particles obtained by polymerizing a polymer stock solution containing a hydrolytic silicide compound (a component b1), a vinyl monomer having a secondary and/or a tertiary amide group (a component b2), an emulsifying agent (a component b3), and water (a component b4). The component C is the complex of two or more kinds of compound selected from the group consisting of zinc oxide, cerium oxide, aluminum hydroxide, zirconium oxide, iron oxide, titanium oxide, and silica dioxide. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coating composition, a laminate, a solar cell cover material, and a solar cell.

  Solar cells can directly convert sunlight into electrical energy. Unlike fossil fuels, solar cells use semi-permanent sunlight as a resource, so they can be used semipermanently and are very clean energy.

The light receiving surface of the solar cell is usually protected by a protective cover made of glass, a weather resistant resin film, or the like. Here, since the protective cover is soiled with dust during long-term use, the light transmittance is lowered, and the energy conversion efficiency of the solar cell is lowered. In particular, with recent environmental pollution, the cover is quickly soiled, and the conversion efficiency of the solar cell tends to decrease early. Although it is desirable to clean a solar cell cover regularly or as needed, since a solar cell cover is generally installed in the outer wall of a roof or a building, cleaning of a cover is not easy.
Under such circumstances, Patent Document 1: Japanese Patent Application Laid-Open No. 10-107303 discloses a surface layer portion having photocatalyst particles and silicone and water repellent fluororesin, or photocatalyst particles, amorphous silica and water repellent fluororesin. Proposed solar cell covers have been proposed.
Patent Document 2: Japanese Patent Laid-Open No. 10-270732 discloses that a protective cover film layer, a fluorine resin film layer, and a photocatalyst-containing surface layer are sequentially provided on the surface of a battery to decompose contaminants attached to the surface. There has been proposed a solar cell cover characterized in that

JP-A-10-107303 JP-A-10-270732

However, in the method described in Patent Document 1, the base material layer of the protective cover film may be deteriorated by the organic substance decomposition action of the photocatalyst in the surface layer portion, and the appearance of the solar cell cover may be deteriorated.
In the method described in Patent Document 2, a fluororesin film layer is provided to prevent the protective cover film layer from deteriorating due to the organic substance decomposition action of the photocatalyst in the surface layer portion, and the manufacturing process tends to be complicated. . Moreover, since an interface exists between the layers, there is a concern about problems such as peeling of the photocatalyst layer. Therefore, a solar cell cover having a simpler layer structure has been demanded.
Furthermore, recent solar cells have a strong demand for low cost and light weight, and the base material used for the solar cell cover is being replaced by a cheap and light resin base material. An aqueous coating agent that can be applied without damaging the resin base material has been desired, including the viewpoint of environmental impact.

  The subject of this invention is providing the coating composition etc. which can form a coating film with favorable weather resistance and antifouling property, and also the favorable protection with respect to a resin base material.

（式中、Ｒは式（１）で定義した通りである。）

［１２］
前記（Ａ’）成分が、光触媒活性を有する［１１］に記載コーティング組成物。
［１３］
前記（Ａ’）成分の粒子長（ｌ）と粒子直径（ｄ）の比（ｌ／ｄ）が、１／１から２０／１である［１１］又は［１２］に記載のコーティング組成物。
［１４］
［１］〜［１３］のいずれかに記載のコーティング組成物にて形成される塗膜と、樹脂基材とを含む積層体。
［１５］
前記塗膜のヘイズが２０以下である［１４］に記載の積層体。
［１６］
前記塗膜の、波長３４０ｎｍの紫外線透過率が９９％以下である［１４］又は［１５］に記載の積層体。
［１７］
［１４］〜［１６］のいずれかに記載の積層体を用いてなる太陽電池用カバー材。
［１８］
［１７］に記載の太陽電池用カバー材を含む太陽電池。 As a result of intensive studies to solve the above problems, the present inventors have reached the present invention.
That is, the present invention is as follows.
[1]
Each component of the following (A), (B), (C),
(A) component: single metal compound particles having a particle size of 1 nm to 400 nm,
(B) component: polymer emulsion particles having a particle size of 10 nm to 800 nm,
(C) component: a composite of multiple metal compounds,
Including
The component (B) is the following components (b1) to (b4):
(B1) component: hydrolyzable silicon compound,
(B2) component: a vinyl monomer having a secondary and / or tertiary amide group,
(B3) component: emulsifier,
(B4) component: water,
Polymer emulsion particles obtained by polymerizing a polymerization stock solution containing
The coating, wherein the component (C) is a composite of two or more selected from the group consisting of zinc oxide, cerium oxide, aluminum hydroxide, zirconium oxide, iron oxide, titanium oxide, and silicon dioxide Composition.
[2]
The coating composition according to [1], wherein a ratio (b2) / (B) (mass ratio) between the component (b2) and the component (B) is 0.1 / 1 to 0.5 / 1. .
[3]
The coating according to [1] or [2], wherein a ratio (b2) / (A) (mass ratio) between the component (b2) and the component (A) is 0.1 / 1 to 1/1. Composition.
[4]
The coating according to any one of [1] to [3], wherein the component (B) has a core / shell structure including a core layer and one or more shell layers covering the core layer. Composition.
[5]
In the core layer, the ratio (b2) / (b1) (mass ratio) between the component (b2) and the component (b1) is 0.01 / 1 to 1/1, and in the outermost layer of the shell layer The coating composition according to [4], wherein the ratio (b2) / (b1) (mass ratio) of the component (b2) to the component (b1) is 0.1 / 1 to 5/1.
[6]
The component (B) is obtained by polymerizing the polymerization stock solution in the presence of seed particles forming the core layer, and the seed particles include the component (b1), the component (b2), and the following ( b5) component,
Component (b5): other vinyl monomer copolymerizable with component (b2),
The coating composition according to [4] or [5], obtained by polymerizing at least one selected from the group consisting of:
[7]
The component (b1) is the following component (b1-1):
(B1-1) component: a hydrolyzable silicon compound having a vinyl polymerizable group,
Including
The ratio (b1-1) / (B) (mass ratio) between the component (b1-1) and the component (B) is 0.01 / 100 to 20/100 [1] to [6]. The coating composition according to any one of the above.
[8]
The coating according to [7], wherein a ratio (b1-1) / (b2) (mass ratio) between the (b1-1) component and the (b2) component is 0.1 / 100 to 100/100. Composition.
[9]
The coating composition according to any one of [1] to [8], wherein the component (A) is formed using any one of silicon dioxide, a metal oxide having photocatalytic activity, or a metal oxide having conductivity. object.
[10]
The coating according to any one of [1] to [9], wherein the ratio (l / d) of the particle length (l) to the particle diameter (d) of the component (A) is 1/1 to 20/1. Composition.
[11]
The component (A) is the following component (A ′):
(A ′) component: triorganosilane unit represented by formula (1), monooxydiorganosilane unit represented by formula (2), dioxyorganosilane unit represented by formula (3), formula ( 4) formed by modifying the single metal compound particles using a modifier compound having at least one structural unit selected from the group consisting of a trioxysilane unit represented by 4) and a difluoromethylene unit. The coating composition according to any one of [1] to [10], comprising a modified metal compound.
R ₃ Si- (1)
(In the formula, each R is independently a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched carbon group having 1 to 30 carbon atoms. (A fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, a phenyl group, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group.)
_{- (R 2 SiO) - (} 2)
(In the formula, R is as defined in formula (1).)

(In the formula, R is as defined in formula (1).)

[12]
The coating composition according to [11], wherein the component (A ′) has photocatalytic activity.
[13]
The coating composition according to [11] or [12], wherein the ratio (l / d) of the particle length (l) to the particle diameter (d) of the component (A ′) is from 1/1 to 20/1.
[14]
The laminated body containing the coating film formed with the coating composition in any one of [1]-[13], and a resin base material.
[15]
The laminate according to [14], wherein the coating film has a haze of 20 or less.
[16]
The laminate according to [14] or [15], wherein the coating film has an ultraviolet transmittance at a wavelength of 340 nm of 99% or less.
[17]
[14] A solar cell cover material comprising the laminate according to any one of [16].
[18]
The solar cell containing the cover material for solar cells as described in [17].

  The coating composition of the present invention is a coating composition that has good weather resistance and antifouling properties, and also has good protection against a resin substrate.

  Hereinafter, the best mode for carrying out the present invention (hereinafter, sometimes abbreviated as “embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

The coating composition of the present embodiment includes the following components (A), (B), and (C):
(A) component: single metal compound particles having a particle size of 1 nm to 400 nm,
(B) component: polymer emulsion particles having a particle size of 10 nm to 800 nm,
(C) component: a composite of multiple metal compounds,
Including
The component (B) is the following components (b1) to (b4):
(B1) component: hydrolyzable silicon compound,
(B2) component: a vinyl monomer having a secondary and / or tertiary amide group,
(B3) component: emulsifier,
(B4) component: water,
Polymer emulsion particles obtained by polymerizing a polymerization stock solution containing
The component (C) is a composite of two or more selected from the group consisting of zinc oxide, cerium oxide, aluminum hydroxide, zirconium oxide, iron oxide, titanium oxide, and silicon dioxide.

The component (A) is considered to act as a curing agent for the component (B) by interacting with the component (B). Examples of the interaction include a hydrogen bond between a hydroxyl group that the component (A) generally has and a secondary and / or tertiary amide group that the component (B) has, or a hydroxyl group that the component (A) generally has. And condensation (chemical bond) with the polymerization product of the component (b1) constituting the component (B).
Moreover, it is preferable that the component (A) exists while forming a continuous layer between the particles of the component (B) while interacting with the component (B). In this case, the transparency and weather resistance of the resulting coating composition can be further improved.

As the single metal compound used for the component (A), from the viewpoint of interaction with the component (B), for example, silicon dioxide, aluminum oxide, antimony oxide, titanium oxide, indium oxide, tin oxide, zirconium oxide, Examples thereof include lead oxide, iron oxide, calcium silicate, magnesium oxide, niobium oxide, and cerium oxide.
Among these, silicon dioxide (silica), aluminum oxide (alumina), antimony oxide, and complex oxides thereof having a large surface hydroxyl group are preferable from the viewpoint of the strength of interaction.
In addition, the “single metal compound particle” referred to in the present embodiment means that the metal compound contained in one particle is one type (single metal compound). Here, it is possible to use two or more of the “single metal compound particles” in combination as the component (A).

The single metal compound used for the component (A) is a compound (hereinafter simply abbreviated as “photocatalyst”) that exhibits photocatalytic activity and / or hydrophilicity upon irradiation with light from the viewpoint of imparting antifouling properties. It is preferable to use When a compound that exhibits photocatalytic activity when irradiated with light is used as the component (A), the surface of the resulting coating composition can exhibit excellent degradation activity and contamination resistance of contaminating organic substances. Further, when a compound that exhibits hydrophilicity by light irradiation is used as the component (A), the surface of the resulting coating composition can exhibit self-cleaning ability (self-cleaning) with water such as rain, and is resistant to contamination. Sex can be expressed. In the present embodiment, “hydrophilic” means that the contact angle of water (20 ° C.) with respect to the surface of the measurement object is preferably 60 ° or less, more preferably 30 ° or less, and still more preferably 20 ° or less. Means that.
In addition, when a photocatalyst (visible light responsive photocatalyst) that exhibits photocatalytic activity and / or hydrophilicity is selected by irradiation with visible light (for example, a wavelength of about 400 nm to 800 nm), the surface of the resulting coating composition has sufficient ultraviolet rays. This is preferable because the environmental purification effect and antifouling effect in a place (such as indoors) where the light is not irradiated are very large.

More specifically, examples of the photocatalyst include 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, etc., and at least selected from Ti, Nb, Ta, V Layered oxides having 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-A-8-89804, JP-A-8-198061, JP-A-9-248465, JP-A-10-99694, JP-A-10-2 It can be cited reference No. Publication 4165). 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, but a rutile type having relatively mild photocatalytic activity is preferable from the viewpoint of ultraviolet absorption.

Examples of the visible light responsive photocatalyst include oxynitride compounds such as TaON, LaTiO ₂ N, CaNbO ₂ N, LaTaON ₂ , and CaTaO ₂ N (see, for example, JP-A-2002-66333), Sm ₂ Ti ₂ S. oxysulfide compounds such as ₂ O ₇ (see, for example JP 2002-233770 _{JP), CaIn 2 O 4, SrIn} 2 O 4, ZnGa 2 O 4, Na 2 Sb 2 O 6 , etc. ^{d 10} of electronic state metal ion Oxides (see, for example, JP-A-2002-59008), titanium oxide precursors (titanium oxysulfate, titanium chloride, alkoxy titanium, etc.) and high surface titanium oxide in the presence of nitrogen-containing compounds such as ammonia and urea. Nitrogen-doped titanium oxide obtained by firing (for example, JP 2002-29750 A, 2002-87818, JP-A-2002-154823, JP-A-2001-207082), titanium oxide precursors (titanium oxysulfate, titanium chloride, alkoxytitanium, etc.) in the presence of sulfur compounds such as thiourea. Sulfur-doped titanium oxide obtained by calcining titanium, oxygen-deficient titanium oxide obtained by subjecting titanium oxide to hydrogen plasma treatment or heat treatment under vacuum (for example, see JP-A-2001-98219), and Is a surface-treated photocatalyst obtained by treating a photocatalyst particle with a platinum halide compound (see, for example, JP-A-2002-239353) or tungsten alkoxide (see, for example, JP-A-2001-286755), etc. Can be preferably mentioned.
Among the visible light responsive photocatalysts, oxynitride compounds and oxysulfide compounds have a large photocatalytic activity by visible light, and can be used particularly preferably.

Moreover, as a single metal compound used for said (A) component, the metal oxide which has electroconductivity is used suitably from a viewpoint of expressing the antistatic performance etc. of the coating composition obtained.
Examples of such conductive metal oxides include indium oxide (ITO) doped with tin, tin oxide (ATO) doped with antimony, tin oxide, and zinc oxide.

  In addition, the said (A) component can be formed using the various single metal compound mentioned above (preferably using as a main component). Here, in the present embodiment, the “main component” means that the proportion of the specific component (the total amount thereof when two or more specific components are used in combination) in the matrix component is preferably 50% by mass or more, More preferably, it is 70 mass% or more, More preferably, it is 90 mass% or more, and it means that 100 mass% may be sufficient.

Examples of forms when the component (A) is used include powders, dispersions, and sols.
The dispersion or sol as used herein refers to primary particles in which the component (A) is in a concentration of 0.01 to 80% by mass, preferably 0.1 to 50% by mass in water and / or a hydrophilic organic solvent. And / or a state of being dispersed as 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, tetrahydrofuran and dioxane, and the like. Examples include ethers, amides such as dimethylacetamide, dimethylformamide, dimethyl sulfoxide, nitrobenzene, and a mixture of two or more thereof.

The number average particle size of the component (A) observed in the dispersion or sol (may be a mixture of primary particles and secondary particles, or only primary particles or secondary particles). May be 1 nm to 400 nm, more preferably 1 nm to 100 nm, still more preferably 3 nm to 80 nm, and particularly preferably 5 nm to 50 nm. The number average particle diameter of the component (A) can contribute to the optical characteristics and the like of a laminate (such as a solar cell cover material) formed using the resulting coating composition. In particular, setting the thickness to 100 nm or less can greatly improve the transparency of the obtained solar cell cover material.
In addition, the number average particle diameter (simply abbreviated as “particle diameter”) in the present embodiment is a value measured according to the method of Examples described later.

As the component (A), from the viewpoint of improving dispersion stability, chemical stability and durability with respect to a solvent, the following component (A ′):
(A ′) component: triorganosilane unit represented by formula (1), monooxydiorganosilane unit represented by formula (2), dioxyorganosilane unit represented by formula (3), formula ( 4) Modification formed by modifying the single metal compound particles with a modifier compound having at least one structural unit selected from the group consisting of trioxysilane units represented by 4) and difluoromethylene units. Metal compounds,
It is preferable to contain. “Modification” means immobilizing the modifier compound on the surface of the single metal compound particle. The immobilization of the modifier compound on the surface of the single metal compound particle is considered to be caused by van der Waals force (physical adsorption) or chemical bonding.

R ₃ Si- (1)
(In the formula, each R is independently a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched carbon group having 1 to 30 carbon atoms. (A fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, a phenyl group, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group.)
_{- (R 2 SiO) - (} 2)
(In the formula, R is as defined in formula (1).)

（式中、Ｒは式（１）で定義した通りである。）

(In the formula, R is as defined in formula (1).)

  Examples of the modifier compound include Si—H group, hydrolyzable silyl group (alkoxysilyl group, hydroxysilyl group, halogenated silyl group, acetoxysilyl group, aminoxysilyl group, etc.), epoxy group, acetoacetyl group, It preferably has a thiol group, an acid anhydride group or the like. In addition, the modifier compound is preferably a silicon compound, a fluoroalkyl compound, or a fluoroolefin polymer. Such a modifier compound can be firmly bonded to the single metal compound particle.

When the specific example of a fluoroalkyl compound is shown in the said modifier compound, the compound shown by Formula (5) can be mentioned.
_{CF 3 (CF 2) g-} Y- (V) w (5)
{In the formula, g represents an integer of 0 to 29. Y represents a w-valent organic group having a molecular weight of 14 to 50,000. w is an integer of 1-20. V is composed of an epoxy group, a hydroxyl group, an acetoacetyl group, a thiol group, a cyclic acid anhydride group, a carboxyl group, a sulfonic acid group, a polyoxyalkylene group, a phosphoric acid group, and a group represented by the following formula (6). It represents at least one functional group selected from the group.
-SiWxRy (6)
(In the formula, 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, a phenoxy group, an aminoxy group, or an amide group. Represents at least one selected group, wherein 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 carbon atom. It represents at least one hydrocarbon group selected from 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, where x is 1 or more. Is an integer of 3 or less, and y is an integer of 0 or more and 2 or less, and x + y = 3.)}

  Moreover, as said modifier compound, from a viewpoint of making the surface energy of the component (A ') obtained small and expressing a self-gradient function, it is a compound with small surface energy {For example, in said formula (1)-(4) The substituent R is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched fluoroalkyl group having 1 to 30 carbon atoms, a linear or branched carbon number 2 to 2. It is preferable to select a compound which is at least one selected from 30 alkenyl groups and / or a compound having a difluoromethylene unit.

Here, “expressing the self-gradient function” means that when a solar cell cover material is formed by laminating a coating composition containing the component (A ′) and the component (B) on a substrate, Corresponding to the properties of the substrate surface (especially hydrophilic / hydrophobic), the concentration gradient of the component (A ′) (the concentration deviation in the layer formed with the coating composition) is autonomously formed. means.
When the photocatalyst modified with a compound having a small surface energy is used as the component (A ′) and a solar cell cover material is formed using a substrate having a large surface hydrophilicity, the component (A ′) It tends to be unevenly distributed on the side in contact with the surface of the base material and decrease in the abundance. In such a case, high photocatalytic activity can be expected, and the substrate is hardly decomposed (durability of the substrate is improved), which is preferable.

  In addition, as the method of the modification treatment, for example, the single metal compound particles and the modifier compound are mixed in the presence or absence of water and / or an organic solvent, preferably 0 to 200 ° C., More preferably, a method of heating at 10 to 80 ° C., or mixing the single metal compound particles and the modifier compound in the presence of a mixed solvent, and changing the solvent composition of the mixed solvent by (reduced pressure) distillation or the like. Method, etc.

  The proportion of the component (A ′) in the component (A) is preferably 0.01 to 100% by mass, more preferably 0.01 to 99.99% by mass, and still more preferably 0.1 to 100% by mass. It is 95 mass%, Most preferably, it is 1-90 mass%. Setting the ratio to 0.01% by mass or more is preferable from the viewpoint of imparting self-gradient. In addition, it is suitable that the said ratio shall be 99.99 mass% or less from a viewpoint of making photocatalytic performance express in a comparatively short time.

In addition, regarding the component (A) or the component (A ′), the ratio (l / d) of the particle length (l) to the particle diameter (d) is a viewpoint of securing a specific surface area and the orientation of the particles. From the viewpoint of the effect, it is preferably 1/1 to 20/1, more preferably 1/1 to 15/1, and further preferably 1/1 to 10/1.
As a method for measuring the particle length and particle diameter, a method of observation with a transmission electron microscope can be used.

The component (B) includes the following components (b1) to (b4):
(B1) component: hydrolyzable silicon compound,
(B2) component: a vinyl monomer having a secondary and / or tertiary amide group,
(B3) component: emulsifier,
(B4) component: water,
Polymer emulsion particles obtained by polymerizing a polymerization stock solution containing As the component (B) thus obtained, it is preferable to use a compound in which the hydroxyl group derived from the component (b1) and the polymerization product of the component (b2) are combined by hydrogen bonding or the like. It is.

As said (b1) component, the compound represented by following formula (7), its condensation product, and a silane coupling agent can be illustrated.
SiWxRy (7)
(In the formula, 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 group, and an amide group. Represents at least one selected group, wherein R represents 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 carbon atom. It represents at least one hydrocarbon group selected from 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, where x is 1 or more and 4; And y is an integer of 0 or more and 3 or less, and x + y = 4.)
In addition, a silane coupling agent means the compound in which the functional group which has reactivity with organic substances, such as a vinyl polymerizable group, an epoxy group, an amino group, a methacryl group, a mercapto group, an isocyanate group, exists in a molecule | numerator.

Specific examples of the compound represented by the formula (7) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, and 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, vinyltriethoxysilane, allyltrimethoxysilane Cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-c Ropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2- Hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyl Trimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxy Silane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyl Trimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, 3-ureidopropyltri Trialkoxysilanes such as methoxysilane and 3-ureidopropyltriethoxysilane;
Dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, di-n-butyldimethoxy Silane, di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldiethoxysilane, di-n-heptyl Dimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxysilane, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyldiethoxysilane, diphenyldimethyl Kishishiran, diphenyl diethoxy silane, 3- (meth) acryloyl dialkoxysilane such as propyl methyl dimethoxy silane;
Monoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane;
Etc. Moreover, these can be used individually or in mixture of 2 or more types.

As the component (b1), 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.
Furthermore, as said (b1) component, the silane coupling agent which has a thiol group, the following (b1-1) component,
(B1-1) Component: A hydrolyzable silicon compound having a vinyl polymerizable group may be included. When these are used, the weather resistance and antifouling properties of the obtained solar cell cover material are favorable, which is preferable.

Examples of the silane coupling agent having a thiol group include 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.
Examples of the component (b1-1) include 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, and 3- (meth) acryloyloxypropylmethyldimethoxysilane. 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, 2-trimethoxysilylethyl vinyl ether Examples thereof include silane coupling agents having a vinyl polymerizable group.
These silane coupling agents can generate chemical bonds by copolymerization or chain transfer reaction with the component (b2) described later. For this reason, when a silane coupling agent having a vinyl polymerizable group or a thiol group is used by mixing or combining with the above-described component (b1), the polymerization product of (b1) and the component (b2) described later These polymerization products can be combined by chemical bonding.
Examples of the “vinyl polymerizable group” referred to as the component (b1-1) include a vinyl group and an allyl group, and among them, a 3 (meth) acryloxypropyl group is preferable.

Moreover, as said (b1) component, the following (b1-2) components,
(B1-2) Component: A cyclic siloxane oligomer may be included. When the said (b1-2) component is used, the softness | flexibility of the solar cell cover material obtained becomes more favorable, and is suitable.

As said cyclic siloxane oligomer, the compound represented by following formula (8) can be illustrated.
(R ′ ₂ SiO) m (8)
(In the formula, 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 an unsubstituted or substituted carbon atom having 1 to 30 carbon atoms. It represents at least one selected from an alkyl group having 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 is there.)
Of these, cyclic dimethylsiloxane oligomers such as octamethylcyclotetrasiloxane are preferred from the viewpoint of reactivity.

  In addition, when the said (b1) component is used as a condensation product, the polystyrene conversion weight average molecular weight (by GPC method) of the said condensation product becomes like this. Preferably it is 200-5000, More preferably, it is 300-1000.

The ratio (b1) / (B) (mass ratio) between the component (b1) and the component (B) described below is preferably 0.01 / 100 to 20/100, from the viewpoint of polymerization stability. Preferably it is 0.1 / 100-10 / 100.
The ratio (b2) / (b1) (mass ratio) between the component (b1) and the component (b2) described later is preferably 5/95 from the viewpoint of reactivity with the component (A). It is -95/5, More preferably, it is 10 / 90-90 / 10.

On the other hand, the ratio (b1-1) / (B) (mass ratio) between the component (b1-1) and the component (B) is preferably 0.01 / 100 to from the viewpoint of polymerization stability. 20/100, more preferably 0.5 / 100 to 10/100.
The ratio (b1-1) / (b2) (mass ratio) between the component (b1-1) and the component (b2) is preferably 0.1 / 100 to from the viewpoint of polymerization stability. 100/100, more preferably 0.5 / 100 to 50/100.
On the other hand, the ratio (b1-2) / (B) (mass ratio) between the component (b1-2) and the component (B) is preferably 0.01 / 100 to 20 from the viewpoint of hydrophilicity. / 100, more preferably 0.5 / 100 to 5/100.
The ratio (b1-2) / (b2) (mass ratio) between the component (b1-2) and the component (b2) is preferably 0.5 / 100 to from the viewpoint of polymerization stability. 50/100, more preferably 1.0 / 100 to 20/100.

Examples of the component (b2) 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-acrylo Ruhexahydroazepine, N-acryloylmorpholine, N-methacryloylmorpholine, N-vinylpyrrolidone, N-vinylcaprolactam, N, N'-methylenebisacrylamide, N, N'-methylenebismethacrylamide, N-vinylacetamide, dye Acetone acrylamide, diacetone methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, etc. can be mentioned.

As the component (b2), it is preferable to use a vinyl monomer having a secondary and / or tertiary amide group from the viewpoint of further improving the hydrogen bondability with other components.
From the viewpoint of improving the polymerization stability in the presence of water and an emulsifier, it is preferable to use N, N-diethylacrylamide as the component (b2).

The ratio (b2) / (B) (mass ratio) between the component (b2) and the component (B) is preferably 0.1 / 1 to 0.5 / 1 from the viewpoint of polymerization stability. is there.
The ratio (b2) / (A) (mass ratio) between the component (b2) and the component (A) is preferably from the viewpoint of hydrogen bondability with the component (A) and blending stability. 0.1 / 1 to 1.0 / 1.

Examples of the component (b3) include acidic emulsifiers such as alkylbenzenesulfonic acid, alkylsulfonic acid, alkylsulfosuccinic acid, polyoxyethylene alkylsulfuric acid, polyoxyethylenealkylarylsulfuric acid, polyoxyethylene distyrylphenyl ether sulfonic acid, Anionic surfactants such as alkali metal (Li, Na, K, etc.) salts of emulsifiers, ammonium salts of acidic emulsifiers, fatty acid soaps;
Quaternary ammonium salts such as alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate, pyridinium salts, imidazolinium salt type cationic surfactants;
Nonionic surfactants such as polyoxyethylene alkyl aryl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene oxypropylene block copolymer, polyoxyethylene distyryl phenyl ether;
Etc. These can be used alone or in combination of two or more.

  As the component (b3), from the viewpoint of improving the water dispersion stability of the component (B) to be obtained, and from the viewpoint of improving the weather resistance and antifouling properties of the resulting solar cell cover material, radical polymerization is possible. It is preferable to use a reactive emulsifier having a double bond.

More specifically, the reactive emulsifier includes, for example, a vinyl monomer having a sulfonic acid group or a sulfonate group, a vinyl monomer having a sulfate ester group, an alkali metal salt thereof, an ammonium salt, a polyoxyethylene, etc. Examples thereof include a vinyl monomer having a nonionic group and a vinyl monomer having a quaternary ammonium salt.
Examples of the vinyl monomer having a sulfonic acid group or a sulfonate group include, for example, a radically polymerizable double bond, and partly by a substituent such as an ammonium salt, a sodium salt, or a potassium salt of the sulfonic acid group. 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 substituent;
A vinyl sulfonate compound having a vinyl group to which a substituent is bonded, such as an ammonium salt, sodium salt or potassium salt of a sulfonic acid group;
Etc.

  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 an ammonium salt, sodium salt or potassium salt of the sulfate ester group. , A compound 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 the sulfonic acid group include allylsulfosuccinate. More specifically, for example, Eleminol JS-2 (trade name) (manufactured by Sanyo Chemical Co., Ltd.), Latemuru S-120, S-180A or S-180 (trade name) (manufactured by Kao Corporation), etc. Can do.
Further, a compound having an alkyl ether group having 2 to 4 carbon atoms or a polyalkyl ether group having 2 to 4 carbon atoms, which is partially substituted by a group which is an ammonium salt, sodium salt or potassium salt of the sulfonic acid group. Specific examples include, for example, Aqualon HS-10 or KH-1025 (trade name) (Daiichi Kogyo Seiyaku Co., Ltd.), Adeka Soap SE-1025N or SR-1025 (trade name) (Asahi Denka Kogyo Co., Ltd.) Manufactured).

  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, manufactured by Dai-ichi Pharmaceutical Co., Ltd.).

  The amount of the component (b3) 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 (B) from the viewpoint of polymerization stability.

  The component (B) is polymer emulsion particles obtained by polymerizing a polymerization stock solution containing the components (b1) to (b3) described above and the component (b4) (that is, “water”). The amount of the component (b4) 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 (b1) to (b4), various components can be further mixed in the polymerization stock solution.
First, the polymerization stock solution contains the following component (b5):
Component (b5): other vinyl monomer copolymerizable with component (b2),
Can be mixed. The use of such component (b5) means that the properties of the polymerization product to be produced (glass transition temperature, molecular weight, hydrogen bonding force, polarity, dispersion stability, weather resistance, polymerization of hydrolyzable silicon compound (b1)) From the viewpoint of controlling compatibility with the product.

Examples of the component (b5) include acrylic acid esters, methacrylic acid esters, aromatic vinyl compounds, vinyl cyanides, carboxyl group-containing vinyl monomers, hydroxyl group-containing vinyl monomers, and epoxy group-containing vinyls. And monomers containing functional groups such as monomers, carbonyl group-containing vinyl monomers, anionic vinyl monomers, and the like.
The proportion of the component (b5) in the total vinyl monomer is preferably 0.001 to 30% by mass, and more preferably 0.05 to 10% by mass. The use amount is such that the glass transition temperature, molecular weight, hydrogen bonding force, polarity, dispersion stability, weather resistance, compatibility with the polymerization product of the hydrolyzable silicon compound (b1), and the like are controlled. To preferred.

Further, a chain transfer agent can be mixed in the polymerization stock solution.
Examples of such 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; thiomalic acid and the like. Thiocarboxylic acids or their salts or their alkyl esters, or polythiols, diisopropylxanthogen disulfide, di (methylenetrimethylolpropane) xanthogen disulfide and thioglycol, and allyl compounds such as dimers of α-methylstyrene be able to.
The amount of these chain transfer agents to be 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. Setting the amount to be used is suitable from the viewpoint of polymerization stability.

Furthermore, a dispersion stabilizer can be mixed in the polymerization stock solution.
Examples of such a dispersion stabilizer include various water-soluble oligomers selected from the group consisting of polycarboxylic acids and sulfonates, polyvinyl alcohol, hydroxyethyl cellulose, starch, maleated polybutadiene, maleated alkyd resins, poly Synthetic or natural water-soluble or water-dispersible various water-soluble polymer substances such as acrylic acid (salt), polyacrylamide, water-soluble or water-dispersible acrylic resin, and the like, one or more of these Mixtures can be used.
The amount of these dispersion stabilizers 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 polymer emulsion particles (B).

The polymerization of the polymerization stock solution described above is preferably carried out in the presence of a polymerization catalyst.
Examples of the polymerization catalyst for the component (b1) include hydrogen halides such as hydrochloric acid and hydrofluoric acid, carboxylic acids such as acetic acid, trichloroacetic acid, trifluoroacetic acid and lactic acid, and sulfonic acids such as sulfuric acid and p-toluenesulfonic acid. Acid 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, acidic or weakly acidic inorganic salts, phthalates Acid compounds such as acid, phosphoric acid and nitric acid; sodium hydroxide, potassium hydroxide, sodium methylate, sodium acetate, tetramethylammonium chloride, tetramethylammonium hydroxide, tributylamine, diazabicycloundecene, ethylene Basic compounds such as amines, diethylenetriamine, ethanolamines, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane; tin compounds such as dibutyltin octylate and dibutyltin dilaurate Etc.
Among them, as the polymerization catalyst for the hydrolyzable silicon compound (b1), not only the polymerization catalyst but also an acidic emulsifier having an action as an emulsifier, particularly an alkylbenzene sulfonic acid having 5 to 30 carbon atoms (such as dodecylbenzene sulfonic acid). Highly preferred.

The polymerization catalyst for the component (b2) is preferably a radical polymerization catalyst that undergoes radical decomposition by heat or a reducing substance to cause addition polymerization of a vinyl monomer. Water-soluble or oil-soluble persulfates, peroxides, azobis compounds and the like are preferably used. More specifically, for example, potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 2,2-azobisisobutyronitrile, 2, Examples include 2-azobis (2-diaminopropane) hydrochloride, 2,2-azobis (2,4-dimethylvaleronitrile), and the like.
In addition, as a usage-amount of a polymerization catalyst, Preferably it is 0.001-5 mass parts with respect to 100 mass parts of all the vinyl monomers. When acceleration of the polymerization rate and polymerization at a low temperature of 70 ° C. or lower are desired, it is advantageous to use a reducing agent such as sodium bisulfite, ferrous chloride, ascorbate, or longalite in combination with the radical polymerization catalyst. is there.

  In the present embodiment, the polymerization of the component (b1) and the polymerization of the component (b2) can be carried out separately. This is preferable because it can be achieved.

As a method for obtaining the component (B), so-called emulsion polymerization in which the emulsifier polymerizes the component (b1) and the component (b2) in the presence of a sufficient amount of water to form micelles is suitable. Yes.
As a method of emulsion polymerization, for example, the component (b1) and the component (b2), and further, the component (b3) as necessary, as they are or in an emulsified state, in a lump or divided, or continuously And a method of polymerizing at a reaction temperature of about 30 to 150 ° C. in the presence of the polymerization catalyst, preferably from atmospheric pressure to 10 MPa as necessary. In some cases, the polymerization may be carried out at a higher pressure or lower temperature.
In addition, as a mixing | blending of superposition | polymerization stock solution, from a viewpoint of superposition | polymerization stability, the amount of final solid content is 0.1-70 mass%, Preferably it is 1-55 mass% of said (b1)-(b4). Each component is preferably blended.

Furthermore, when performing the emulsion polymerization, it is preferable to use a seed polymerization method from the viewpoint of appropriately growing or controlling the particle diameter. 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, more preferably 1.0 to 6.0. The pH can be adjusted using a pH buffer such as disodium phosphate, borax, sodium hydrogen carbonate, or ammonia.
In addition, as a method of obtaining the component (B), the component (b1) and the component (b2) in the presence of the component (b3) and the component (b4) necessary for polymerizing the component (b1). A method in which water is added until the polymerization product becomes an emulsion after the components are polymerized in the presence of a solvent, if necessary, can also be applied.

As the component (B), a core layer and the core layer are coated from the viewpoint of improving mechanical properties (such as a balance between strength and flexibility) of a coating film formed using the resulting coating composition. It is preferable to have a core / shell structure including one layer or two or more shell layers. As a method for forming the core / shell structure, multistage emulsion polymerization in which the emulsion polymerization is performed in multiple stages is very useful.
In addition, the component (B) has a core / shell structure, and a continuous layer is formed in a state where the shell layer interacts with the component (A), and a particulate core layer is present in the continuous layer. It is preferable. In this case, chemical resistance, optical properties, and mechanical properties (such as a balance between strength and flexibility) of the resulting coating composition can be improved.

  More specifically as an example of multi-stage emulsion polymerization, for example, as the first stage, in the presence of the component (b3) and the component (b4), a group consisting of the components (b1), (b2), and (b5) At least one selected from the above is polymerized to form seed particles, and in the second stage, in the presence of the seed particles, the component (b1) and the component (b2), and further, if necessary (b5) And a method of polymerizing by adding a polymerization stock solution containing the component (two-stage polymerization method). Such a method is also suitable from the viewpoint of polymerization stability.

Here, as a mass ratio of the solid content mass (M1) in the polymerization stock solution used in the first stage and the solid content mass (M2) in the polymerization stock solution added in the second stage, the polymerization stability is From the viewpoint, preferably (M1) / (M2) = 9/1 to 1/9, more preferably 8/2 to 2/8.
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 particles are obtained by the second stage polymerization. It is preferable to have a structure with an increased diameter. The volume average particle diameter can be measured in the same manner as the number average particle diameter.

The core / shell structure can be observed, for example, by morphological observation using a transmission electron microscope or the like, analysis by viscoelasticity measurement, or the like.
Moreover, when implementing multistage emulsion polymerization of 3 steps | paragraphs or more, what is necessary is just to increase the number of the steps to superpose | polymerize with reference to the 2 step | paragraph polymerization method mentioned above.

The glass transition temperature (Tg) of the core layer having the core / shell structure is preferably 0 ° C. or lower. In this case, as a physical property of the coating composition to be obtained, it becomes possible to form a solar cell cover material that is excellent in flexibility at room temperature and hardly causes cracking or the like.
In addition, Tg in this Embodiment can be measured with a differential scanning calorimeter (DSC).

  In the core layer, the ratio (b2) / (b1) (mass ratio) between the component (b2) and the component (b1) is preferably 0.01 / 1 to 1/1. In the outermost layer of the shell layer, the ratio (b2) / (b1) (mass ratio) between the component (b2) and the component (b1) is preferably 0.1 / 1 to 5/1. is there. When these ratios are set within the above range, both the weather resistance and mechanical properties of the resulting coating composition are particularly good and preferable.

  The particle size of the component (B) is 10 nm to 800 nm. By adjusting to such a particle diameter range and forming the composition in combination with the component (A) having a particle diameter of 1 nm to 400 nm, the weather resistance and antifouling properties are good, and the resin base material A coating composition with good protection can be realized. Moreover, it is suitable from a viewpoint of the transparency improvement of the coating film obtained that the particle diameter of the said (B) component shall be 50 nm-300 nm.

The ratio (A) / (B) (mass ratio) of the component (A) to the component (B) is preferably 1/99 to 99/1, more preferably 5/95 to 90/10, and even more preferably. Is 9/91 to 83/17. The coating composition blended in this range is preferable because a solar cell cover material having excellent weather resistance and antifouling properties can be realized.
The ratio (SA) / (SB) of the surface area (SA) of the component (A) and the surface area (SB) of the component (B) is preferably in the range of 0.001 to 1000. The surface area can be calculated from the particle diameter of each of the component (A) and the component (B) and the blending mass number.

  As the component (C), two or more composites selected from the group consisting of zinc oxide, cerium oxide, aluminum hydroxide, zirconium oxide, iron oxide, titanium oxide, and silicon dioxide are used. In the present embodiment, the “composite of a plurality of metal compounds” is a compound obtained by using a plurality of any of the metal compounds included in the above group. It does not specifically limit to the aspect of compounding. For example, a core / shell structure in which one metal compound forms a core and another metal compound forms one or more shells covering the core may be used. Further, a sea-island structure in which other metal compounds form an island phase may be used.

As said titanium oxide, a rutile type titanium oxide is preferable from a viewpoint of dispersion stability and base-material protection. The zinc oxide, cerium oxide, aluminum hydroxide, zirconium oxide, iron oxide, and titanium oxide are preferably partially or entirely covered with silica from the viewpoint of dispersion stability.
Here, as a compounding quantity of the said (C) component, Preferably it is 0.1 mass part-80 mass parts with respect to 100 mass parts of total amounts of the said (A) component and the said (B) component. Setting the blending amount of component (C) to 0.1 parts by mass or more is preferable from the viewpoint of reducing the coating film transmittance of ultraviolet light having a wavelength of 340 nm and preventing deterioration of the base material by ultraviolet light. On the other hand, it is suitable to set it as 80 mass parts or less from a viewpoint of implement | achieving sufficient coating-film strength.
Moreover, as a particle diameter of the said (C) component, from a viewpoint of coating-film transparency, Preferably it is 10 nm-600 nm, More preferably, it is 20 nm-200 nm. Setting the particle diameter to 10 nm or more is preferable from the viewpoint of reducing the haze of the coating film.
In addition, a commercial item can be used as said (C) component. Examples of such commercially available products include trade names “MPT-144”, “TTO-S-1”, and “TTO-F-1” manufactured by Ishihara Sangyo Co., Ltd.

  In the coating composition of the present embodiment, additive components that are usually added to and blended with paints and molding resins, for example, light stabilizers, ultraviolet absorbers, thickeners, depending on the application and usage method. 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 inhibitors, dyes, plasticizers, lubricants, reducing agents, antiseptics, antifungal agents, deodorants, anti-yellowing agents, antistatic agents or electrification A regulator 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.
Moreover, as said 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 the organic ultraviolet absorber. Using both in combination can contribute to improving the weather resistance of the resulting coating composition.
Moreover, these organic ultraviolet absorbers, light stabilizers, and various additive components can be simply blended with the component (A) and the component (B), or the component (B) is synthesized. It is also possible to coexist when doing so.

The laminate of the present embodiment is a laminate comprising a resin substrate and a coating film formed from the above-described coating composition, and preferably a coating comprising the resin substrate and the above-described coating composition. It is a laminate composed of a film.
Moreover, the cover material for solar cells of this Embodiment is formed using the said laminated body, Preferably it forms as a laminated body which consists of a resin base material and the coating film which consists of a coating composition mentioned above.
Furthermore, the solar cell of the present embodiment includes the solar cell cover material.
Here, as said base material, organic base materials, such as a synthetic resin and a natural resin, inorganic base materials, such as glass, those combinations, etc. can be mentioned, for example.

The coating composition described above is not particularly limited, but can be prepared in a state dissolved or dispersed in a solvent such as water.
The coating film is formed by, for example, applying the coating composition (sometimes abbreviated as “water dispersion”) dispersed in a solvent such as water on the substrate and drying it. The Here, as solid content concentration of an aqueous dispersion, Preferably it is 0.01-60 mass%, More preferably, it is 1-40 mass%. The viscosity of the aqueous dispersion is preferably 0.1 to 100,000 mPa · s, preferably 1 to 10,000 mPa · s at 20 ° C. Further, examples of the coating method include spray spraying, flow coating, roll coating, brush coating, dip coating, spin coating, screen printing, casting, gravure printing, flexographic printing, and the like. Can be mentioned. The laminate is, for example, after drying the coating film on the base material, preferably subjected to heat treatment or ultraviolet irradiation at 20 ° C. to 500 ° C., more preferably 40 ° C. to 250 ° C., if desired. It is also possible to form.

The thickness of the coating film is preferably 0.05 to 100 μm, more preferably 0.1 to 10 μm. From the viewpoint of transparency, the thickness is preferably 100 μm or less, and in order to exhibit functions such as weather resistance and antifouling properties, the thickness is preferably 0.05 μm or more.
The “coating film” referred to in the present embodiment is not necessarily a continuous film, and may be a discontinuous film, an island-shaped dispersion film, or the like.

The haze of the coating film may be selected comprehensively from the viewpoint of the strength and durability of the coating film and the conversion efficiency of the solar cell, but is preferably 20 or less, more preferably 10 from the viewpoint of the conversion efficiency of the solar cell. Hereinafter, it is more preferably 5 or less.
Moreover, the ultraviolet transmittance at a wavelength of 340 nm of the laminate is preferably 99% or less, more preferably 95% or less.
The “haze” and “ultraviolet ray transmittance” as used herein can be measured according to the examples described later, and can be adjusted according to the particle size of the components (A) to (C). It is.

  Next, the present embodiment will be described more specifically with reference to examples and comparative examples. However, the present embodiment is not limited to the following examples unless it exceeds the gist. Various physical properties were evaluated by the following methods.

1. Number average particle diameter A sample was appropriately diluted by adding a solvent so that the solid content in the sample was 1 to 20% by mass, and measured using a wet particle size analyzer (Microtrac UPA-9230, manufactured by Nihon Koki Co., Ltd.).
2. Composition Stability After creating the coating composition, the sedimentation state of the particles was visually determined. Evaluation was made according to the following criteria.
○: Good ×: Sedimentation 3. Initial CA
A surface of the solar cell cover material (coating surface of the coating composition) is placed with deionized water droplets and allowed to stand at 20 ° C. for 1 minute, and then a contact angle measuring device (CA-X150 model contact angle, manufactured by Kyowa Interface Science, Japan). ).
4). Initial haze, haze after water resistance Using a turbidimeter (NDH2000, Nippon Denshoku Industries Co., Ltd., Japan), the haze value of the coating film of the coating composition was measured according to JIS-K7105 (initial haze value).
The haze after water resistance is a haze value measured after being immersed in deionized water at 23 ° C. for 24 hours and then dried at 23 ° C. for 12 hours.
5. Ultraviolet light transmittance A composition for a solar cell cover material is formed on a PET film so as to have a film thickness of 1 μm, the transmittance at a wavelength of 340 nm is measured with a V-550 manufactured by JASCO Corporation, and the ultraviolet light per 1 μm film thickness is measured. The rate was determined.
6). Contamination-resistant visual observation After creating a composition for a cover material for solar cells, the composition was applied to an exposure table (south surface, exposure angle 90 degrees) facing a general road for one month, and then the degree of contamination was evaluated according to the following criteria.
A: Almost no dirt adhered. ○: Rain streaks dirt slightly adhered. After weathering, haze A sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.) was used to conduct an exposure test (black panel temperature 63 ° C., rainfall 18 minutes / 2 hours). 3. Haze value after 2000 hours of exposure It evaluated according to the method of description, and it was set as the haze value after a weather resistance.
8). Substrate protection The cover material for solar cells was irradiated with ultraviolet light at an illuminance of 10 mW for 6 hours using a UV irradiator (UV300 manufactured by Oak Manufacturing Co., Ltd.). Then, the yellowing degree of the base material (PET film) was evaluated using a color difference meter (color guide 45/0 manufactured by BYK Gardner). The Δb value for the PET film before UV light irradiation was measured and evaluated according to the following criteria.
○: Less than 1 △: 1 or more and less than 5

[Production Example 1]
[10 mass% aqueous dispersion of emulsion particles]
Into a reactor having a reflux condenser, a dropping tank, a thermometer, and a stirring device, 1600 g of ion-exchanged water and 3 g of dodecylbenzenesulfonic acid were added, and then the temperature was heated to 80 ° C. with stirring. 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, a mixed solution of 86 g of butyl acrylate, 133 g of phenyltrimethoxysilane, 1.3 g of 3-methacryloxypropyltrimethoxysilane, 137 g of diethylacrylamide, 3 g of acrylic acid, a reactive emulsifier (trade name “ADEKA rear soap SR-1025” Asahi Denka Co., Ltd., 25% solid content aqueous solution) 13 g, ammonium persulfate 2 mass% aqueous solution 40 g, and ion-exchanged water 1900 g mixed solution with the temperature in the reaction vessel kept at 80 ° C. for about 2 hours It was dripped at the same time. Further, stirring was continued for about 2 hours in a state where the temperature in the reaction vessel was 80 ° C., and then cooled to room temperature. After filtration through a 100 mesh wire mesh, the solid content was adjusted to 10% by mass with ion-exchanged water to obtain a 10% by mass aqueous dispersion (number average particle size 160 nm) of emulsion particles (component (B)).

[Examples 1 to 3, Comparative Example 1]
A coating composition was obtained with the formulation shown in Table 1.
The obtained coating composition was bar-coated on a 10 cm × 10 cm PET film so as to have a film thickness of 1 μm, and then dried at 70 ° C. for 10 minutes to obtain a solar cell cover material. These evaluation results are shown in Table 1.

[10 mass% aqueous dispersion of colloidal silica]
A product name “Snowtex O” (component (A)) manufactured by Nissan Chemical Industries, Ltd. dispersed in water (solid content 10% by mass, number average particle size 10 nm).
[10 mass% aqueous dispersion of silica-coated titanium oxide]
A product name “TSK-5” (component (A)) manufactured by Ishihara Sangyo Co., Ltd. dispersed in water (solid content 10 mass%, number average particle size 73 nm).
[10 mass% aqueous dispersion of “MPT-144”]
A product name “MPT-144” (component (C)) manufactured by Ishihara Sangyo Co., Ltd. dispersed in water (solid content: 10% by mass). SiO ₂ / ZnO (mass ratio) included in “MPT-144” = 1.3 / 3.8.
[10 mass% aqueous dispersion of “TTO-S-1”]
A product name “TTO-S-1” (component (C)) manufactured by Ishihara Sangyo Co., Ltd. dispersed in water (solid content: 10% by mass). TiO ₂ / Al (OH) ₃ / ZrO ₂ (mass ratio) included in “TTO-S-1” = 4.4 / 0.5 / 0.2.
[10 mass% aqueous dispersion of “TTO-F-1”]
A product name “TTO-F-1” (component (C)) manufactured by Ishihara Sangyo Co., Ltd. dispersed in water (solid content: 10% by mass). TiO ₂ / Al (OH) ₃ / ZrO ₂ / Fe ₂ O ₃ (mass ratio) included in “TTO-F-1” = 3.9 / 0.7 / 0.2 / 0.3.
[10 mass% aqueous dispersion of magnesium oxide]
Wako Pure Chemical Industries, Ltd. magnesium oxide dispersed in water (solid content 10% by mass).

Claims (18)

Each component of the following (A), (B), (C),
(A) component: single metal compound particles having a particle size of 1 nm to 400 nm,
(B) component: polymer emulsion particles having a particle size of 10 nm to 800 nm,
(C) component: a composite of multiple metal compounds,
Including
The component (B) is the following components (b1) to (b4):
(B1) component: hydrolyzable silicon compound,
(B2) component: a vinyl monomer having a secondary and / or tertiary amide group,
(B3) component: emulsifier,
(B4) component: water,
Polymer emulsion particles obtained by polymerizing a polymerization stock solution containing
The coating, wherein the component (C) is a composite of two or more selected from the group consisting of zinc oxide, cerium oxide, aluminum hydroxide, zirconium oxide, iron oxide, titanium oxide, and silicon dioxide Composition.   The coating composition according to claim 1, wherein the ratio (b2) / (B) (mass ratio) of the component (b2) and the component (B) is 0.1 / 1 to 0.5 / 1. .   The coating composition according to claim 1 or 2, wherein a ratio (b2) / (A) (mass ratio) between the component (b2) and the component (A) is 0.1 / 1 to 1/1. .   The coating according to any one of claims 1 to 3, wherein the component (B) has a core / shell structure including a core layer and one or more shell layers covering the core layer. Composition.   In the core layer, the ratio (b2) / (b1) (mass ratio) between the component (b2) and the component (b1) is 0.01 / 1 to 1/1, and in the outermost layer of the shell layer The coating composition according to claim 4, wherein a ratio (b2) / (b1) (mass ratio) of the component (b2) to the component (b1) is 0.1 / 1 to 5/1. The component (B) is obtained by polymerizing the polymerization stock solution in the presence of seed particles forming the core layer, and the seed particles include the component (b1), the component (b2), and the following ( b5) component,
Component (b5): other vinyl monomer copolymerizable with component (b2),
The coating composition according to claim 4 or 5, which is obtained by polymerizing at least one selected from the group consisting of: The component (b1) is the following component (b1-1):
(B1-1) component: a hydrolyzable silicon compound having a vinyl polymerizable group,
Including
The ratio (b1-1) / (B) (mass ratio) between the component (b1-1) and the component (B) is 0.01 / 100 to 20/100. A coating composition according to claim 1.   The coating according to claim 7, wherein a ratio (b1-1) / (b2) (mass ratio) of the component (b1-1) and the component (b2) is 0.1 / 100 to 100/100. Composition.   The coating composition according to any one of claims 1 to 8, wherein the component (A) is formed using any one of silicon dioxide, a metal oxide having photocatalytic activity, or a metal oxide having conductivity. object.   The coating according to any one of claims 1 to 9, wherein the ratio (l / d) of the particle length (l) to the particle diameter (d) of the component (A) is 1/1 to 20/1. Composition. The component (A) is the following component (A ′):
(A ′) component: triorganosilane unit represented by formula (1), monooxydiorganosilane unit represented by formula (2), dioxyorganosilane unit represented by formula (3), formula ( 4) formed by modifying the single metal compound particles using a modifier compound having at least one structural unit selected from the group consisting of a trioxysilane unit represented by 4) and a difluoromethylene unit. Modified metal compounds,
The coating composition according to claim 1, comprising:
R ₃ Si- (1)
(In the formula, each R is independently a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched carbon group having 1 to 30 carbon atoms. (A fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, a phenyl group, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group.)
_{- (R 2 SiO) - (} 2)
(In the formula, R is as defined in formula (1).)

(In the formula, R is as defined in formula (1).)

  The coating composition according to claim 11, wherein the component (A ′) has photocatalytic activity.   The coating composition according to claim 11 or 12, wherein the ratio (l / d) of the particle length (l) to the particle diameter (d) of the component (A ') is from 1/1 to 20/1.   The laminated body containing the coating film formed with the coating composition in any one of Claims 1-13, and a resin base material.   The laminate according to claim 14, wherein the coating film has a haze of 20 or less.   The laminate according to claim 14 or 15, wherein the coating film has an ultraviolet transmittance at a wavelength of 340 nm of 99% or less.   The cover material for solar cells which uses the laminated body in any one of Claims 14-16.   The solar cell containing the cover material for solar cells of Claim 17.