JP5497480B2 - Thermal barrier composition, solar cell member and solar cell - Google Patents

Description

  The present invention relates to a heat shielding composition, a solar cell member, and a solar cell.

  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. In particular, solar cells and solar thermal power generation are attracting attention because they are excellent in safety and ease of handling.

  In solar cells, the light receiving surface is protected by a protective cover made of glass, weather-resistant resin film, etc., but the protective cover is contaminated with dust during long-term use, resulting in a decrease in light transmittance. There is a problem that the energy conversion efficiency decreases. In addition, crystalline silicon and polycrystalline silicon type solar cells have a problem that power generation efficiency decreases as the temperature increases as a characteristic of silicon.

As a technique for preventing surface contamination, for example, Patent Document 1 discloses that tungstic acid and distilled water dissolved in ammonia water on an anatase-type titanium oxide-containing layer formed on the surface of a base material to be subjected to antifouling. A technique is disclosed in which a surface shielding layer made of tungsten oxide is formed by applying a heat-shielding liquid to which is added, followed by baking at 700 ° C. Patent Document 2 discloses a composite material having a hydrophilic surface, which is bonded to a base material and the surface of the base material, and is made of TiO ₂ , ZnO, SnO ₂ , SrTiO ₃ , WO ₃ , Bi ₂ O ₃ , Fe. _{2. A} composite comprising a photocatalytic semiconductor material selected from the group consisting of ₂ O ₃ and a photocatalytic coating containing silica, wherein the surface of the coating exhibits hydrophilicity in response to photoexcitation of the photocatalytic semiconductor material A material is disclosed.

JP-A-10-114545 Japanese Patent No. 2756474

  However, from the viewpoint of excellent antifouling property and total light transmittance, and suppressing the temperature rise of the solar cell by the infrared heat shielding effect and improving the power generation efficiency, there is room for improvement in all of the above-mentioned patent documents. It was.

  The present invention has been made in view of the above circumstances, and provides a heat-shielding composition that is excellent in antifouling properties and total light transmittance, and that can suppress an increase in the temperature of a solar cell by an infrared shielding effect and contribute to an improvement in power generation efficiency. The main purpose is to do.

As a result of intensive studies aimed at solving the above problems, the present inventors have reached the present invention.
That is, the present invention is as follows.
[1]
(A1) component: silica having a number average particle diameter of 1 nm to 400 nm,
(A2) component: an infrared absorber having a number average particle diameter of 1 nm to 2000 nm;
Component (B): number average particle diameter observed containing a polymer emulsion particles 10Nm～800nm, a,
The mass ratio of the total content ((A1 + A2) / (B)) of the component (A1) and the component (A2) to the content of the component (B) is 100/100 to 500/100,
The mass ratio of the content of the component (A2) to the total content of the component (B) and the component (A1) ((A2) / (B + A1)) is 0.05 / 100 to 40/100.
Thermal barrier composition.
[2]
[1] The component (A2) is at least one selected from the group consisting of indium oxide doped with tin, tin oxide doped with antimony, cerium oxide, zinc oxide, and the agent coated with silica. The heat shielding composition as described.
[3]
The component (B) is
(B1) component: a hydrolyzable silicon compound;
(B2) component: 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;
(B3) component: an emulsifier,
(B4) Heat shielding material according to [1] or [2], which is polymer emulsion particles obtained by polymerizing the component (b1) and the component (b2) in a polymerization stock solution containing water. Composition.
[ 4 ]
The mass ratio ((b2) / (B)) of the content of the component (b2) to the content of the component (B) is 0.1 / 1 to 0.5 / 1, [1] to [ 3 ] The heat-shielding composition as described in any one of the above.
[ 5 ]
The mass ratio of the content of the component (b2) to the content of the component (A1) ((b2) / (A1)) is 0.1 / 1 to 1/1, [1] to [ 4 ] The heat insulation composition as described in any one of these.
[ 6 ]
In any one of [1] to [ 5 ], the component (B) has a core / shell structure including a core layer and one or more shell layers covering the core layer. The heat shielding composition as described.
[ 7 ]
In the core layer, the mass ratio of the content of the component (b2) to the content of the component (b1) ((b2) / (b1)) is 0.01 / 1 to 1/1.
In the outermost layer of the shell layer, the mass ratio of the content of the component (b2) to the content of the component (b1) ((b2) / (b1)) is 0.1 / 1 to 5/1. [ 6 ] The heat-shielding composition according to [ 6 ].
[ 8 ]
The component (B) is a polymer emulsion particle obtained by polymerizing the component (b1) and the component (b2) in the polymerization stock solution containing seed particles that form the core layer.
The seed particles polymerize at least one component selected from the group consisting of the component (b1), the component (b2), and (b5) another vinyl monomer copolymerizable with the component (b2). The heat-shielding composition according to [ 6 ] or [ 7 ], which is a particle obtained as described above.
[ 9 ]
The thermal insulation composition according to any one of [3] to [ 8 ], wherein the component (b2) is a vinyl monomer having a secondary amide group and / or a tertiary amide group.
[ 10 ]
(C) component: It further includes one or more hydrolyzable silicon compounds selected from the group consisting of compounds represented by the following formulas (1), (2) and (3),
Any of [1] to [ 9 ], wherein the mass ratio ((C) / (A1)) of the content of the component (C) to the content of the component (A1) is 1/100 to 100/100 The heat-insulating composition according to any one of the above.

R ¹ _n SiX _4-n (1)

(In Formula (1), R1 is a hydrogen atom or a C1-C10 alkyl which may have a halogen group, a hydroxy group, a mercapto group, an amino group, a (meth) acryloyl group or an epoxy group. Represents a 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.)

X ₃ Si—R ² _n —SiX ₃ (2)

(In formula (2), X represents a hydrolyzable group, R2 represents a C1-C6 alkylene group or a phenylene group. N is 0 or 1.)

R ³ — (O—Si (OR ³ ) ₂ ) _n —OR ³ (3)

(In Formula (3), R3 represents a C1-C6 alkyl group. N is an integer of 2-8.)
[ 11 ]
The heat-shielding composition according to any one of [1] to [ 10 ], wherein the number average particle diameter of the component (B) is 10 nm to 100 nm .
[ 12 ]
The heat shielding composition according to any one of [1] to [ 11 ], wherein the component (A1) is colloidal silica having a number average particle diameter of 1 nm to 400 nm.
[ 13 ]
The heat shielding composition according to any one of [1] to [ 12 ], wherein the component (A2) has an absorption of 0.1% or more in a wavelength region of a wavelength of 1000 nm to 2500 nm.
[ 14 ]
A substrate;
A coating film formed by applying and drying the thermal barrier composition according to any one of [1] to [ 13 ] on the substrate;
A solar cell member comprising:
[ 15 ]
The solar cell member according to [ 14 ], which is a solar cell protective member.
[ 16 ]
[ 14 ] or the member for solar cell according to [ 15 ],
A backsheet disposed opposite to the solar cell member;
A power generation element disposed between the solar cell member and the backsheet;
A solar cell comprising:

  The heat-shielding composition of the present invention is excellent in antifouling properties and total light transmittance, and can contribute to improvement in power generation efficiency by suppressing the temperature increase of the solar cell by the infrared heat-shielding effect.

It is a simplified sectional view of one mode of a solar cell of this embodiment.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of the gist. In the present specification, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto, “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto, “(Meth) acryloyl” means “acryloyl” and its corresponding “methacryloyl”.

  The thermal barrier composition of the present embodiment includes (A1) component: silica having a number average particle size of 1 nm to 400 nm, (A2) component: infrared absorbing agent having a number average particle size of 1 nm to 2000 nm, and (B). Component: A heat shielding composition containing polymer emulsion particles having a number average particle diameter of 10 nm to 800 nm.

  The component (A1) is considered to act as a curing agent for the component (B) by interacting with the component (B). Examples of the interaction include, for example, a hydrogen bond between a hydroxyl group that the component (A1) generally has and a hydroxyl group, carboxyl group, amide group, amino group, and ether group that the component (B) has, and a hydroxyl group that the component (A1) generally has. And condensation (chemical bond) with the polymerization product of the component (b1) constituting the component (B).

  The component (A1) is preferably present while forming a continuous phase between the particles of the component (B) while interacting with the component (B). As a result, silica particles with high hydrophilicity always exist on the outermost surface of the coating film, so that high hydrophilicity can be obtained immediately after the coating film formation regardless of light irradiation, and transparency and weather resistance are also improved. It can be improved.

  Component (A1) may be silica (so-called silicon dioxide), and production methods such as precipitation and dry methods are not particularly limited, but colloidal silk is preferred. When the component (A1) is 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 its number average particle diameter is preferably 1 nm to 400 nm, more preferably 1 nm to 200 nm, still more preferably 1 nm. It is -100nm, More preferably, it is 5nm-30nm. When the number average particle diameter is 1 nm or more, the storage stability of the heat-shielding composition is better, and when it is 100 nm or less, the transparency of the coating film is better. Colloidal silica having a particle size in the above range can be used in the state of an aqueous dispersion, whether acidic or basic, and depending on the stable region of the aqueous dispersion of component (B) mixed together. The pH can be appropriately selected.

  Examples of acidic colloidal silica using water as a dispersion medium include, for example, commercially available products such as SNOWTEX (trademark) -O, SNOWTEX OS, SNOWTEX-OL, manufactured by Nissan Chemical Industries, Ltd., and Asahi Denka Kogyo Co., Ltd. Examples thereof include Adelite (trademark) AT-20Q, Clevosol (trademark) 20H12 manufactured by Clariant Japan Co., Ltd., and clebosol 30CAL25.

  Examples of basic colloidal silica include silica stabilized by 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-manufactured by Nissan Chemical Industries, Ltd. N30, Snowtex-K, Snowtex-XL, Snowtex-YL, Snowtex-ZL, Snowtex PS-M, Snowtex PS-L, etc., Adelite AT-20, Adelite AT manufactured by Asahi Denka Kogyo Co., Ltd. -30, Adelite AT-20N, Adelite AT-30N, Adelite AT-20A, Adelite AT-30A, Adelite AT-40, Adelite AT-50 etc. DuPont Le Box (TM) 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 (methanol dispersion type having a number average particle diameter of 20 nm to 25 nm), IPA-ST (manufactured by Nissan Chemical Industries, Ltd.) Isopropyl alcohol dispersion type having a number average 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 having a number average particle diameter of 70 nm to 100 nm) Glycol dispersion type), NPC-ST (ethylene glycol monopropyl ether dispersion type having a number average particle diameter of 10 nm to 15 nm), and the like.

  These colloidal silicas are used alone or in combination of two or more. Colloidal silica may contain alumina, sodium aluminate or the like 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.

  The infrared absorbing agent as component (A2) is an agent having an absorption band in the infrared region (wavelength of 800 nm or more), and is an organic substance, an inorganic substance, or a mixture thereof. Examples of the infrared absorbing agent include inorganic fine particles and organic fine particles. Specific examples of the inorganic fine particles include fine particles coated with cerium oxide, zinc oxide, and silica, and tin-doped indium oxide (ITO). Transparent conductive fine particles such as antimony-doped tin oxide (ATO) and fluorine-doped tin oxide (FTO), noble metal fine particles such as silver, gold, platinum, rhodium and palladium, and the formula MxWyOz (where M element is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al , Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os Represents one or more elements selected from the group consisting of Bi and I, W represents tungsten, O represents oxygen, 0.0001 ≦ x / y ≦ 1.5, 1.0 ≦ z / y ≦ 5.0) and the like. In addition, fine particles having absorption in the ultraviolet region, such as zirconium oxide, tin oxide, bismuth oxide, and titanium oxide, can be used singly or in combination of two or more. Since these infrared absorbers are relatively stable and can be made into fine particles, it is preferable because they can absorb wavelengths in the infrared region while suppressing scattering in the visible light region. Among these, at least one selected from the group consisting of ITO, ATO, cerium oxide, zinc oxide, and the agent coated with silica is more preferable.

  As long as the organic fine particles have a dye having a maximum absorption wavelength in the near-infrared (800 nm to 1100 nm) wavelength band, the type and composition thereof are not limited. For example, a diimonium-based near-infrared absorbing dye is preferable. The diimonium-based near-infrared absorbing dye has a strong absorption with a molar extinction coefficient of about 100,000 in the near-infrared region with a wavelength of 850 nm to 1100 nm and a slight absorption in the visible light region with a wavelength of 400 nm to 500 nm. However, it is preferable for obtaining a high transmittance in the visible light region because the visible light permeability is superior to other near infrared absorbing dyes. One or more dyes selected from the group consisting of phthalocyanine dyes, organometallic complex dyes, and cyanine dyes having an absorption maximum at a wavelength of 750 nm to 950 nm and no absorption in the visible light region are used. Or may be used in combination. In addition, conductive polymers represented by polyaniline, polypyrrole, polythiophene, polyvinyl sulfonic acid and the like can be used.

  For the purpose of imparting heat insulation to the coating film, a color pigment can be used alone or in combination as the component (A2). In this case, for example, a color pigment having a solar reflectance of 13% or more as defined in JIS A5759-1998 is preferable. Specifically, white pigments such as titanium white and zinc oxide pigments as white pigments; Red pigments such as iron pigments and quinacridone pigments; yellow pigments such as iron oxide pigments, iron hydroxide pigments, lead chromate pigments and azo pigments; blue such as phthalocyanine blue and complex oxide pigments Examples of pigments include green pigments such as chrome green and phthalocyanine green pigments.

  Ideally, the infrared absorbing agent has no absorption in the infrared wavelength of sunlight, particularly in the wavelength region corresponding to the absorption band of silicon, but the average reflectance in the visible ultraviolet region wavelength of 300 nm to 780 nm is 25% or less, It is preferable that the average reflectance in an infrared region wavelength of 780 nm to 2500 nm is 15% or more.

  When the component (A2) has infrared absorption, it is preferable that the component has absorption of 0.1% or more in the wavelength range of 1000 nm to 2500 nm. The region having a wavelength of 1000 nm to 2500 nm is a wavelength region in which infrared rays are efficiently converted into heat, and preferably has an absorption of 0.1% or more in this wavelength region, more preferably 10% or more. However, since this wavelength region also overlaps with the absorption region of silicon, the addition amount can be adjusted according to the infrared absorption ability of the infrared absorber.

  By making the particle diameter such that the light having the absorption band wavelength of silicon is not scattered by particle scattering, the temperature rise can be efficiently suppressed without adversely affecting the power generation performance of the solar cell. From such a viewpoint, the number average particle diameter is preferably 10 nm to 2000 nm, more preferably 10 nm to 1500 nm, and still more preferably 10 nm to 1000 nm. When the number average particle size is 10 nm or more, dispersion stability can be maintained, and when the number average particle size is 2000 nm or less, even when the amount of the component (A2) is large, the scattered light is not increased and the power generation efficiency of the solar cell is improved. It will not decline.

  In general, since these infrared absorbing agents tend to be difficult to disperse in an aqueous solvent, it is preferable to use an infrared absorbing agent whose surface is uniformly or non-uniformly coated with silica. Thereby, the compounding stability with (A1) component, the weather resistance of an infrared absorber, etc. can further be improved. The method for coating the infrared absorbing agent with silica is not particularly limited, and a known method can be adopted. For example, the infrared absorbing agent is dispersed in water, dispersed with a high-pressure morphizer, and then stirred with tetraethoxysilane. It can be obtained by adding temperature or water glass and controlling the temperature while adjusting the pH appropriately.

  The form of the component (A2) is not particularly limited, and examples thereof include powders, dispersions, and sols. The “dispersion liquid” and “sol” as used herein means that the component (A2) 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. It means a state of being dispersed as primary particles and / or secondary particles.

  The particle size of the component (A2) observed in the dispersion or sol may be a number average particle size (a mixture of primary particles and secondary particles, or only one of primary particles and secondary particles). It may be.) The number average particle diameter of the component (A2) can contribute to the optical characteristics of the coating film formed using the obtained heat shielding composition. In particular, setting the number average particle diameter to 100 nm or less can greatly improve the transparency of the resulting coating film. In addition, the number average particle diameter in this embodiment is a value measured according to the method of the Example mentioned later.

  The mass ratio ((A1 + A2) / B) of the total content of the component (A1) and the component (A2) to the content of the component (B) is not particularly limited, but the total light transmittance and infrared absorption From the viewpoint, it is preferably 60/100 to 1000/100, more preferably 100/100 to 500/100, and still more preferably 120/100 to 300/100.

  The mass ratio ((A2) / (B + A1)) of the content of the component (A2) to the total content of the component (B) and the component (A1) is preferably from the viewpoint of the total light transmittance of the coating film. It is 05 / 100-40 / 100, More preferably, it is 0.1 / 100-20 / 100, More preferably, it is 0.1 / 100-10 / 100.

  Since the component (A2) is more likely to cause secondary aggregation than the component (A1), the mass ratio of the content of the component (A2) to the total content of the component (B) and the component (A1) ((A2 ) / (A1 + B)) is 40/100 or less, the transparency of the coating film can be increased and the decrease in light transmittance due to scattering can be suppressed. By setting the mass ratio ((A2) / (A1 + B)) of the content of the component (A2) to the total content of the component (B) and the component (A1) to 0.05 / 100 or more, the coating film Infrared absorption on the surface can be increased, temperature rise of silicon can be suppressed, and power generation efficiency can be improved.

  In this embodiment, “hydrophilic” means that the contact angle of water (23 ° C.) with respect to the surface of the measurement object is preferably 60 ° or less, more preferably 30 ° or less, and even more preferably 20 ° or less. Means nature.

  If necessary, the heat-shielding composition of the present embodiment can contain a metal oxide having conductivity in addition to the components (A1) and (A2). Thereby, antistatic performance etc. can be provided to a thermal insulation composition. The metal oxide having such conductivity is not particularly limited, and a known metal oxide can be used. For example, indium oxide doped with tin (ITO), tin oxide doped with antimony (ATO), oxidized Examples thereof include tin and zinc oxide. From the viewpoint of interaction with the component (B), 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. It can also be used together.

  The polymer emulsion particles of component (B) are at least one selected from the group consisting of component (b1): hydrolyzable silicon compound and component (b2): hydroxyl group, carboxyl group, amide group, amino group and ether group. The weight obtained by polymerizing the component (b1) and the component (b2) in a polymerization stock solution containing a vinyl monomer having a functional group of (b3): component (emulsifier) and component (b4): water. Combined emulsion particles. As the component (B) thus obtained, a compound in which a hydroxyl group derived from the component (b1) and a polymerization product of the component (b2) are combined by hydrogen bonding or the like can be suitably used.

Examples of the component (b1) include a compound represented by the following formula (4), a condensation product thereof, a silane coupling agent, and the like.

SiW _x R _y (4)

Here, 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. It represents at least one group selected from the group consisting of groups. 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 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, vinyltrie Xysilane, 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, 3 Mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxy Silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) ata Cryloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, 3-ureidopropyltrimethoxysilane 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-hexyldimethoxysilane Di-n-hexyldiethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxysilane, di-n-cyclohexyldimethyl Dialkoxysilanes such as xyloxysilane, di-n-cyclohexyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane; monoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane And the like. Moreover, these may be used individually by 1 type or may use 2 or more types together.

  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.

  The component (b1) may contain a silane coupling agent having a thiol group or a component (b1-1): a hydrolyzable silicon compound having a vinyl polymerizable group. When these are used as the component (b1), 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 (b1-1) include 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- ( Vinyl polymerization such as (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxypropyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, 2-trimethoxysilylethyl vinyl ether Examples thereof include a silane coupling agent having a functional 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 component (b1) described above, the polymerization product of the component (b1) and the component (b2) described later are used. The polymerization product can be complexed by chemical bonding.

  Examples of the “vinyl polymerizable group” in the component (b1-1) include a vinyl group and an allyl group, and among these, a 3- (meth) acryloxypropyl group is preferable.

  The component (b1) may contain a component (b1-2): a cyclic siloxane oligomer. When the said (b1-2) component is used, the softness | flexibility of the coating film obtained becomes more favorable and is suitable.

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

_{(R '2 SiO) m (} 5)

Here, 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 carbon number. It shows 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.

  When a condensation product is used as the component (b1), the weight average molecular weight in terms of polystyrene of the condensation product (according to the GPC method) is preferably 200 to 5,000, more preferably 300 to 1,000.

  In the heat-shielding composition of this embodiment, the mass ratio ((b1) / (B)) of the content of the component (b1) to the content of the component (B) is preferably from the viewpoint of polymerization stability. 01/100 to 80/100, more preferably 0.1 / 100 to 70/100.

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

  Specific examples of the hydroxyl group-containing vinyl monomer mentioned as the component (b2) include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Various 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; polyethylene glycol Monoesters of polyoxyalkylene glycols obtained from various polyether polyols typified by (2) and various unsaturated carboxylic acids typified by (meth) acrylic acid; various hydroxyl group-containing monomers described above And adducts of various lactones typified by ε-caprolactone; adducts of 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) Etc.

  Specific examples of the carboxyl group-containing vinyl monomer exemplified as the component (b2) include (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, crotonic acid, itaconic acid, maleic acid, and 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 (half-esters) of succinic acid with saturated monohydric alcohols; monovinyl esters of various saturated dicarboxylic acids such as monovinyl adipate or monovinyl succinate; succinic anhydride, glutaric anhydride, phthalic anhydride or anhydrous Of various saturated polycarboxylic acids such as trimellitic acid Addition reaction products of waters and the above-mentioned various hydroxyl group-containing vinyl monomers; monomers obtained by addition reaction of the above-mentioned various carboxyl group-containing monomers and lactones, etc. Is mentioned.

  Specific examples of the amino group-containing vinyl monomer mentioned as the component (b2) include, for example, 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, and 2-di-n-propylaminoethyl. Contains various tertiary amino groups such as (meth) acrylate, 3-dimethylaminopropyl (meth) acrylate, 4-dimethylaminobutyl (meth) acrylate or N- [2- (meth) acryloyloxy] ethylmorpholine (meta ) 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- 2-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 acids such as -di-n-propylamino) ethylcrotonamide, N- (3-dimethylamino) propylcrotonamide or N- (4-dimethylamino) butylcrotonamide Amides; 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 (b2) 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, Japan) Manufactured by Yushi Co., Ltd., trade name), MA-30, MA-50, MA-100, MA-150, RA-1120, RA-2614, RMA-564, RMA-568, RMA-1114, MPG130-MA ( As mentioned above, Nippon Emulsifier Co., Ltd., a brand name) etc. are mentioned. 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 (b2) include, for example, 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.

  As said (b2) component, it is preferable to use the vinyl monomer which has a secondary and / or tertiary amide group from a viewpoint of improving a hydrogen bond property with another component more. In particular, a vinyl monomer having a tertiary amide group is preferable from the viewpoint of hydrogen bonding strength.

  In the heat-shielding composition of this embodiment, the mass ratio ((b2) / (B)) of the content of the component (b2) to the content of the component (B) is preferably from the viewpoint of polymerization stability. It is 1/1 to 0.5 / 1, more preferably 0.2 / 1 to 0.4 / 1.

  The mass ratio ((b2) / (A1)) of the content of the component (b2) to the content of the component (A1) is preferably from the viewpoint of hydrogen bonding with the component (A1) and blending stability. 1/1 to 1/1, more preferably 0.2 / 1 to 0.7 / 1.

  Examples of component (b3) include acidic emulsifiers such as alkylbenzene sulfonic acids, alkyl sulfonic acids, alkyl sulfosuccinic acids, polyoxyethylene alkyl sulfuric acids, polyoxyethylene alkyl aryl sulfuric acids, polyoxyethylene distyryl phenyl ether sulfonic acids, and acidic emulsifiers. Anionic surfactants such as alkali metal (Li, Na, K, etc.) salts, 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 Polymers, nonionic surface active agent polyoxyethylene distyryl phenyl ether, and the like. These are used singly or in combination of two or more.

  As the component (b3), a reaction having a radical polymerizable double bond from the viewpoint of improving the water dispersion stability of the obtained component (B) 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, for example, vinyl monomers having a sulfonic acid group or sulfonate group, vinyl monomers having a sulfate ester group, and nonionic groups such as alkali metal salts, ammonium salts, and polyoxyethylene thereof. Examples thereof include a vinyl monomer 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. And a compound having a substituent, such as an ammonium salt, a sodium salt, or a potassium salt of a sulfonic acid group, and a vinyl sulfonate compound having a vinyl group to which a substituent is bonded.

  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. Can be mentioned.

  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 (manufactured by Sanyo Chemical Co., Ltd., trade name), Latemul S-120, S-180A or S-180 (trade name, produced by Kao Corporation) and the like can be mentioned.

  A compound having an alkyl ether group having 2 to 4 carbon atoms or a polyalkyl ether group having 2 to 4 carbon atoms partially substituted by a substituent such as an ammonium salt, sodium salt or potassium salt of the sulfonic acid group; As specific examples, for example, 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) Etc.

  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.) , Daiichi Pharmaceutical Industry Co., Ltd.).

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

  The component (B) is a weight obtained by polymerizing the component (b1) and the component (b2) in the polymerization stock solution containing the components (b1) to (b3) and the component (b4) (that is, water). Combined emulsion particles. The amount of 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, it is preferable to further mix (b5) component: (b2) component with another vinyl monomer copolymerizable with the polymerization stock solution. The use of such a 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, hydrolyzable silicon compound as component (b1) From the viewpoint of controlling the compatibility with the polymerization product, etc.).

  As the component (b5), for example, acrylic ester, methacrylic ester, aromatic vinyl compound, vinyl cyanide, epoxy group-containing vinyl monomer, carbonyl group-containing vinyl monomer, anionic vinyl monomer And monomers containing a functional group such as a body.

  (B5) 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 (b5) in this range means that glass transition temperature, molecular weight, hydrogen bonding force, polarity, dispersion stability, weather resistance, compatibility with polymerized product of hydrolyzable silicon compound as component (b1) From the viewpoint of controlling the above and the like.

  A chain transfer agent can be mixed in the polymerization stock solution. Examples of the chain transfer agent 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 acid such as thiomalic acid Or salts thereof or alkyl esters thereof, or polythiols, diisopropylxanthogen disulfide, di (methylenetrimethylolpropane) xanthogen disulfide and thioglycol, and allyl compounds such as α-methylstyrene dimer.

  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. 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 resin, and polyacrylic. Synthetic or natural water-soluble or water-dispersible water-soluble polymer substances such as acid (salt), polyacrylamide, water-soluble or water-dispersible acrylic resin, and the like can be mentioned. These are used singly or in combination of two or more.

  The amount of these dispersion stabilizers to be 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) 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 (b1) 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, 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 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, ethylenedia , Diethylenetriamine, ethanolamines, basic compounds such as γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane; tin compounds such as dibutyltin octylate and dibutyltin dilaurate Etc. Among them, as a polymerization catalyst for the hydrolyzable silicon compound which is the component (b1), acidic emulsifiers having an action as an emulsifier as well as a polymerization catalyst, particularly alkylbenzenesulfonic acid (dodecylbenzenesulfonic acid having 5 to 30 carbon atoms). Etc.) is preferred.

  As the polymerization catalyst for the component (b2), a radical polymerization catalyst that undergoes radical decomposition with 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 preferable. 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-azobisisobutyrate. Examples include rhonitrile, 2,2-azobis (2-diaminopropane) hydrochloride, 2,2-azobis (2,4-dimethylvaleronitrile), and the like.

  The amount of the polymerization catalyst used is preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of the total vinyl monomer. 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 this embodiment, the polymerization of the component (b1) and the polymerization of the component (b2) can be carried out separately, but if carried out at the same time, a micro organic / inorganic composite by hydrogen bonding or the like can be achieved. Therefore, it is preferable.

  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. As a method of emulsion polymerization, for example, the components (b1) and (b2) and, if necessary, the component (b3) as it is or in an emulsified state, are batched 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 the polymerization stock solution, from the viewpoint of polymerization stability, the components (b1) to (b4) are blended so that the final solid content is in the range of 0.1 to 70% by mass, preferably 1 to 55% by mass. It is preferable to do this.

  In carrying out the 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 (B) 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 (B), in the presence of the component (b3) and the component (b4) necessary for polymerizing the component (b1), the component (b1) and the component (b2) are optionally added in the presence of a solvent. A method of adding water after polymerization until the polymerization product becomes an emulsion can also be applied.

  The component (B) is composed of a core layer and one or more layers covering the core layer from the viewpoint of improving the substrate adhesion of the coating film formed using the heat-shielding composition containing the component. It is preferable to have a core / shell structure with a shell layer. 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 component (B) is a polymer emulsion particle obtained by polymerizing the component (b1) and the component (b2) in the polymerization stock solution containing the seed particles that form the core layer. Obtained by polymerizing at least one component selected from the group consisting of the component (b1), the component (b2) and the component (b5) other vinyl monomer copolymerizable with the component (b2). More preferably, it is a particle. Again, multi-stage emulsion polymerization is useful.

  Specifically, the multistage emulsion polymerization is, for example, as the first stage, in the presence of the component (b3) and the component (b4), and at least selected from the group consisting of the component (b1), the component (b2), and the component (b5). One or more components are polymerized to form seed particles, and as a second step, a polymerization stock solution containing components (b1) and (b2), and optionally (b5) components 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 a third stage, polymerization may be carried out by adding a polymerization stock solution further containing the component (b1) and the component (b2) and, if necessary, the component (b5). 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.

  In the polymer emulsion particles (B) according to this embodiment, in the core layer, the mass ratio of the content of the (b2) component to the content of the (b1) component ((b2) / (b1)) is 0.00. It is preferable that it is 01/1 to 1/1. (B2) / (b1) in the core layer is preferably 0.01 / 1 or more from the viewpoint of polymerization stability and 1/1 or less from the viewpoint of durability and flexibility. In the outermost layer of the shell layer, the mass ratio of the content of the component (b2) to the content of the component (b1) ((b2) / (b1)) is from the viewpoint of obtaining an appropriate interaction with the component (A). 0.1 / 1 to 5/1 is preferable.

  The core / shell structure can be observed by, for example, morphological observation with a transmission electron microscope or the like, analysis by viscoelasticity measurement, or the like.

  The glass transition temperature (Tg) of the core layer of the core / shell structure is preferably 0 ° C. or lower. In this case, since the obtained heat-shielding composition is excellent in flexibility at room temperature as a physical property of the coating film, it is possible to form a protective member for a solar cell that is less likely to be cracked or the like. In the present embodiment, Tg can be measured with a differential scanning calorimeter (DSC).

  (B) The number average particle diameter of a component is 10 nm-800 nm. By adjusting the particle diameter of the component (B) to such a range and forming the composition in combination with the component (A1) having a number average particle diameter of 1 nm to 400 nm, weather resistance and antifouling properties are improved. . From the viewpoint of improving the transparency of the resulting coating film, the number average particle size of the component (B) is preferably 10 nm to 100 nm.

  The ratio ((SA1) / (SB)) of the surface area (SA1) of the component (A1) and the surface area (SB) of the component (B) 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 each of the components (A1) and (B), assuming that the particle shape is a true sphere.

  In addition to the above-described components, the heat-shielding composition of the present embodiment is usually an additive component that is added and blended with a paint or a molding resin depending on the application and usage method, for example, a light stabilizer, UV absorber, thickener, leveling agent, thixotropic agent, antifoaming agent, freeze stabilizer, matting agent, crosslinking reaction catalyst, pigment, curing catalyst, crosslinking agent, filler, anti-skinning agent, dispersant, Wetting agent, antioxidant, UV absorber, rheology control agent, film forming aid, rust inhibitor, dye, plasticizer, lubricant, reducing agent, preservative, antifungal agent, deodorant, yellowing inhibitor An antistatic agent, a charge control agent, or the like can be selected or combined in accordance with each 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 in combination can contribute to improving the weather resistance of the resulting heat-shielding composition. Moreover, these organic ultraviolet absorbers, light stabilizers, and various additive components can be simply blended with the component (A1), the component (A2) and the component (B), or the component (B). It is also possible to coexist when synthesizing.

The heat-shielding composition of this embodiment preferably further contains a hydrolyzable silicon compound as component (C) for the purpose of improving the strength and antifouling properties of the coating film. As the hydrolyzable silicon-containing compound used as the component (C), a hydrolyzable silicon-containing compound (c1) 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 (c2) and a hydrolyzable silicon compound (c3) represented by the following formula (3) can be used.

R ¹ _n SiX _4-n (1)

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.

X ₃ Si—R ² _n —SiX ₃ (2)

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. n is 0 or 1.

R ³ — (O—Si (OR ³ ) ₂ ) _n —OR ³ (3)

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

  Specific examples of the hydrolyzable silicon compounds (c1) and (c2) include tetramethoxysilane, tetraethoxysilane, tetra (n-propoxy) silane, tetra (i-propoxy) silane, 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, methyldimethoxysilane , 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- Hydroxypropyltriethoxy 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, tetrabutyl Lomosilane, 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.

  Specific examples of the hydrolyzable silicon compound (c3) 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.). Trade name "MSI51" manufactured by Colcoat Co., Ltd., "MS51" and "MS56" manufactured by Mitsubishi Chemical Corporation), and a partially hydrolyzed condensate of tetoethoxysilane (trade name manufactured by Tama Chemical Industry Co., Ltd.) "Silicate 35", "Silicate 45", trade names "ESI40" and "ESI48" manufactured by Colcoat Co., Ltd.), co-partial hydrolysis condensate of tetramethoxysilane and tetraethoxysilane (Tama Chemical Co., Ltd.) ) Product name “FR-3”, product name “EMSi48” manufactured by Colcoat Co., Ltd.) and the like.

  The said hydrolysable silicon compound which is (C) component is used individually by 1 type or in combination of 2 or more types.

  Moreover, in the heat-shielding composition of this embodiment, the mass ratio ((C) / (A1)) of the content of the component (C) to the content of the component (A1) is preferably 0.2 / 100 to 300. / 100, more preferably 1/100 to 100/100. If (C) / (A1) is 0.2 / 100 or more, a sufficiently low contact angle tends to be obtained under high temperature conditions, and if (C) / (A1) is 300/100 or less, sufficient. There is a tendency to obtain a good coating strength.

  The thermal barrier composition of the present embodiment is not particularly limited, but can be prepared as a state dissolved and / or dispersed in water and, if necessary, another solvent.

  The thermal insulation composition of this embodiment can be used suitably as a member for solar cells. As a member for solar cells, what is provided with the base material and the coating film formed by apply | coating and drying the thermal-insulation composition of this embodiment on the said base material is mentioned, for example. This coating film can be suitably used as a protective film for solar cells. Therefore, the solar cell member of this embodiment can be more suitably used as a solar cell protective member.

  The substrate used in the present embodiment is not particularly limited, and for example, a material whose material is glass or resin is preferably used. From the viewpoint of transparency, weather resistance, and weight reduction, the material constituting the substrate is at least selected from the group consisting of glass, acrylic resin, polycarbonate resin, cyclic olefin resin, polyethylene terephthalate resin, and ethylene-fluoroethylene copolymer. One kind of material or a composite material thereof is preferable. A weathering agent or the like may be further kneaded into the acrylic resin, polycarbonate resin, cyclic polyolefin resin, polyethylene terephthalate resin, or ethylene-fluoroethylene copolymer for the purpose of imparting weather resistance.

  In addition, the solar cell member of the present embodiment is, for example, coated on the base material with the above heat-shielding composition (sometimes abbreviated as “water dispersion”) dispersed in a solvent such as water. It is formed by drying. Here, the solid content concentration of the aqueous dispersion is preferably 0.01 to 60% by mass, more preferably 1 to 40% by mass. The viscosity of the aqueous dispersion is preferably 0.1 to 100,000 mPa · s, more preferably 1 to 10,000 mPa · s at 20 ° C. Furthermore, as a method for applying the heat shielding composition to the substrate, for example, spray spraying method, flow heat shielding method, roll coating method, bar coating method, brush coating method, dip heat shielding method, spin heat shielding method, screen printing Method, casting method, gravure printing method, flexographic printing method and the like. In addition, after drying a coating film on a base material, it is also possible to obtain by performing heat processing, ultraviolet irradiation, etc. preferably at 100 degrees C or less if desired.

  Thus, the obtained coating film is the said (A1) component, (A2) component, (B) component, and the said (C) component and the said additive component which can remain | survive as solid content as needed. Is included.

  The thickness of the coating film is preferably 0.05 μm to 100 μm, more preferably 0.1 μm to 10 μm. From the viewpoint of transparency, the thickness is preferably 100 μm or less, and in order to more effectively express functions such as weather resistance and antifouling properties, the thickness is preferably 0.05 μm or more.

  The refractive index of the coating film is preferably 1.3 to 1.5. From the viewpoint of increasing the light transmittance, it is more preferably 1.3 to 1.45. In this embodiment, since the refractive index of the component (A1) and the component (A2) are greatly different, in order to control the refractive index within the above range in a composition having a high content of the component (A1), the component (A2) Of course, it is also useful to disperse the component (A2) as uniformly as possible in the coating film. In the present embodiment, the “coating film” is not necessarily a continuous film, and may be a discontinuous film, an island-shaped dispersion film, or the like.

  The heat-insulating composition of the present embodiment can be suitably used as a solar cell member such as a solar cell protective member by forming a coating film as described above. The haze value of the coating film is preferably 10% or less from the viewpoint of increasing the light transmittance. Here, the “haze value” is measured according to the method described in Examples described later.

  According to the heat-shielding composition, the coating film and the solar cell member using the same according to the present embodiment, the antifouling property, the total light transmittance, and the infrared shielding property are excellent, and the increase in the module temperature of the solar cell can be suppressed. Since it is possible, it can be set as a high output solar cell especially in a crystal type solar cell.

  FIG. 1 is a simplified cross-sectional view of one aspect of the solar cell of the present embodiment. The solar cell 1 of this embodiment is disposed between a solar cell member 10, a back sheet 12 disposed to face the solar cell member 10, and between the solar cell member 10 and the back sheet 12. Power generation element 14. Furthermore, the power generation element 14 is sealed with a sealing material 16. In the solar cell 1, sunlight L enters from the solar cell member 10 side and reaches the power generation element 14.

  The solar cell member 10 is a protective member that protects the power generation element 14 and the like. The solar cell member 10 has a coating film 104 formed on the surface of a substrate 102. In this case, the solar cell member 10 functions as a light-transmitting substrate that transmits sunlight, and is excellent in the above-described antifouling property and infrared shielding property, and thus can suppress an increase in the module temperature of the solar cell. And it is preferable to use the member 10 for solar cells so that the surface in which the said coating film 104 was formed may become the surface side of the solar cell 1. FIG.

  It is preferable that the solar cell member 10 has performance for ensuring long-term reliability in outdoor exposure of the solar cell 1, 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 102 is not particularly limited, and the above-described materials can be used. More 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 is preferable. Among these, weather resistance, A glass substrate is more preferable from the viewpoint of balance between impact properties and cost.

  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 coating film 104, the above-described coating film can be used. The method described above can also be used as a method of forming the coating film 104 on the substrate 102.

  Although there is no limitation in particular as the back seat | sheet 12, 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 member 10 for solar cells. Therefore, you may comprise a back seat | sheet with the material similar to the member 10 for solar cells. That is, the various materials described above that can be used in the solar cell member 10 (particularly, the base material 102) 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 back sheet 12 does not assume the passage of sunlight, the transparency (translucency) required for the solar cell member 10 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 1 or for preventing distortion or warping 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 back sheet 12 may have a multilayer structure composed of 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 symmetrically arranged 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 14 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 -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 sealing material 16 is not particularly limited as long as it is a member that can seal the power generation element 14. For example, a resin sealing sheet containing a resin such as ethylene-vinyl acetate copolymer (EVA) or the like Is mentioned. By heat-melting such a resin sealing sheet, the resin sealing sheet can be in close contact with the power generation element 14 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 solar cell member (protective member) 10 and the back sheet 12 can be exhibited.

  It does not specifically limit as a manufacturing method of the solar cell in this Embodiment, A well-known method is also employable. For example, the solar cell member (protective member) 10 / sealing material 16 / power generation element 14 / sealing material 16 / back sheet 12 are stacked in this order and vacuum laminated using a vacuum laminator at 150 ° C. for 15 minutes. Can be manufactured.

  Although the thickness of each member of the solar cell 1 is not particularly limited, the thickness of the solar cell member (protective member) 10 is preferably 3 mm or more from the viewpoint of weather resistance and impact resistance, and the thickness of the back sheet 12 is The thickness of the power generation element 14 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 16 is cushioning and sealing. From a viewpoint, 250 micrometers or more are preferable.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to a following example, unless the summary is exceeded. Various physical properties were evaluated by the following methods.

1. Number-average particle size Particles contained in the sample using a wet particle size analyzer (Nikkiso Microtrac UPA-9230) diluted appropriately by adding a solvent so that the solid content in the sample is 1 to 20% by mass The number average particle size of was measured.

2. Initial contact angle After placing a drop of deionized water on the surface of the coating film and leaving it at 23 ° C. for 1 minute, using a contact angle measurement device (Kyowa Interface Science, CA-X150 contact angle meter), The contact angle was measured.

3. Total light transmittance Using a turbidimeter (trade name “NDH2000” manufactured by Nippon Denshoku Industries Co., Ltd.), in accordance with JIS-K7105, a member for an energy conversion device, which is a laminate of a substrate and a coating film, and a coating film The total light transmittance was measured.

4). Refractive index The refractive index (wavelength: 633 nm) of the coating film laminated | stacked on the base material was measured using the film thickness meter (Otsuka Electronics make, brand name "FE-3000").

5. Infrared absorptivity Infrared spectrophotometer ("FT / IR4100" manufactured by JASCO Corporation was used to measure the infrared absorptance of the coating film (measurement wavelength 1300 nm)

6). Solar cell module A solar cell module obtained by applying a shielding composition to a solar cell with a rated output of 70 W, exposed outdoors (Kawasaki City) at an inclination angle of 30 degrees, and attached to the back of the module The temperature of the solar cell module was measured. The weather at the time of measurement was fine and the atmospheric temperature was 28 ° C.

[Production Example 1]
<Synthesis of Polymer Emulsion Particle (B-1) Water Dispersion>
Into a reaction vessel having a reflux condenser, a dropping tank, a thermometer and a stirring device, 1600 g of ion-exchanged water and 6 g of dodecylbenzenesulfonic acid were added, and then the temperature was heated to 80 ° C. with stirring. To this, a mixed solution of 185 g of dimethyldimethoxysilane and 117 g of phenyltrimethoxysilane was dropped over about 2 hours while keeping the temperature in the reaction vessel at 80 ° C., and then the temperature in the reaction vessel was raised to 80 ° C. Stirring was continued for about 1 hour in the maintained state. Next, 86 g of butyl acrylate, 133 g of phenyltrimethoxysilane and 1.3 g of 3-methacryloxypropyltrimethoxysilane, 137 g of diethylacrylamide, 3 g of acrylic acid, a reactive emulsifier (trade name, manufactured by Asahi Denka Co., Ltd.) In a state where the temperature in the reaction vessel was kept at 80 ° C., a mixture of 13 g of “Adekaria soap SR-1025”, 25 wt% solid content aqueous solution), 40 g of 2 wt% ammonium persulfate aqueous solution and 1900 g of ion-exchanged water. It was dripped simultaneously over about 2 hours. Further, stirring was continued for about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C., and then the liquid was cooled to room temperature and filtered through a 100-mesh wire mesh, and then the solid content in the liquid was removed with ion-exchanged water. The aqueous dispersion of polymer emulsion particles having a number average particle diameter of 70 nm as component (B) was obtained by adjusting to 10.0% by mass.

[Example 1]
Colloidal silica (manufactured by Nissan Chemical Industries, Ltd., trade name “Snowtex-OS” (component (A1)) is diluted with water to form a dispersion having a solid content of 10% by mass (number average particle diameter of particles 8 nm). The ATO fine particle dispersion having a solid content of 10% by mass, the particle size of 30 nm (component (A2)) and the aqueous dispersion of the polymer emulsion particles synthesized in Production Example 1 were converted into A1 / A2 in terms of solid content. / B = 100/5/100 (mass ratio) was blended to obtain a heat-shielding composition.The obtained heat-shielding composition was white glass (thickness 2 mm, 6 × 6 cm so that the film thickness was 500 nm). After applying by dip coating on the corner, the film was dried at 70 ° C. for 30 minutes to obtain a heat-shielding coating film.
The obtained heat-shielding coating film had physical properties of an initial contact angle of 12 degrees, a total light transmittance of 94, a refractive index of 1.40, an infrared absorption of 5%, and a solar cell module temperature of 45 ° C.

[Example 2]
As in Example 1, except that tetraethoxysilane (special grade reagent manufactured by Wako Pure Chemical Industries) was added as a component (C) at a ratio of A1 / A2 / B / C = 200/10/100/100 (mass ratio). A thermal barrier coating was obtained.
The physical properties of the obtained heat-shielding coating film were an initial contact angle of 8 degrees, a total light transmittance of 93.5%, a refractive index of 1.42, an infrared absorption rate of 3%, and a solar cell module temperature of 46 ° C.

[Example 3]
Colloidal silica (manufactured by Nissan Chemical Industries, Ltd., trade name “Snowtex-OS” (component (A1)) is diluted with water to form a dispersion having a solid content of 10% by mass (number average particle diameter of particles 8 nm). The Cs / W composite oxide fine particle dispersion (Cs ratio 0.3) having a solid content of 2% by mass, the particle diameter of 60 nm (component (A2)) and the polymer emulsion particles synthesized in Production Example 1 were prepared. Aqueous dispersion, tetraethoxysilane (manufactured by Wako Pure Chemicals, reagent grade) as component (C) is blended at a ratio of A1 / A2 / B / C = 200/5/100/100 (mass ratio) in terms of solid content. The obtained heat-shielding composition was applied on white glass (thickness 2 mm, 6 × 6 cm square) by dip coating so as to have a film thickness of 500 nm, and then at 70 ° C. for 30 minutes. It dried and obtained the heat-shielding coating film.
The physical properties of the obtained heat-shielding coating film were an initial contact angle of 9 degrees, a total light transmittance of 93.1, a refractive index of 1.40, an infrared absorption rate of 5%, and a solar cell module temperature of 45 ° C.

[Comparative Example 1]
A heat-shielding coating film was obtained in the same manner as in Example 1 except that the component A2 was not included.
The physical properties of the obtained heat-shielding coating film were an initial contact angle of 15 degrees, a total light transmittance of 93.2%, a refractive index of 1.39, an infrared absorption rate of 0%, and a solar cell module temperature of 48 ° C.

  From the above, it was confirmed that the heat-shielding composition of each Example was excellent in antifouling property and total light transmittance, and was able to suppress the temperature increase of the solar cell by the infrared shielding effect and contribute to the improvement of power generation efficiency.

  The coating film using the heat-shielding composition of the present invention is excellent in antifouling property, total light transmittance, and infrared shielding property, and can suppress the temperature rise of the solar cell. It can be used for the purpose of improving.

DESCRIPTION OF SYMBOLS 1 Solar cell 10 Solar cell member 12 Back sheet 14 Power generation element 16 Sealing material 102 Base material 104 Coating film L Incident light

Claims (16)

(A1) component: silica having a number average particle diameter of 1 nm to 400 nm,
(A2) component: an infrared absorber having a number average particle diameter of 1 nm to 2000 nm;
(B) component: polymer emulsion particles having a number average particle diameter of 10 nm to 800 nm,
Only including,
The mass ratio of the total content ((A1 + A2) / (B)) of the component (A1) and the component (A2) to the content of the component (B) is 100/100 to 500/100,
The mass ratio of the content of the component (A2) to the total content of the component (B) and the component (A1) ((A2) / (B + A1)) is 0.05 / 100 to 40/100.
Thermal barrier composition.   The component (A2) is at least one selected from the group consisting of indium oxide doped with tin, tin oxide doped with antimony, cerium oxide, zinc oxide, and the agent coated with silica. The heat shielding composition as described. The component (B) is
(B1) component: a hydrolyzable silicon compound;
(B2) component: 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;
(B3) component: an emulsifier,
The thermal barrier composition according to claim 1 or 2, which is polymer emulsion particles obtained by polymerizing the component (b1) and the component (b2) in a polymerization stock solution containing the component (b4): water. . Wherein the relative amount of the component (B) component (b2) weight ratio of the content of ((b2) / (B)) is 0.1 / 1 to 0.5 / 1, claim 1-3 The heat insulation composition as described in any one of these. Wherein (A1) the relative content of the component component (b2) weight ratio of the content of ((b2) / (A1)) is 0.1 / 1 to 1/1, one of the claims 1-4 The heat-insulating composition according to any one of the above. The said (B) component has a core / shell structure provided with a core layer and the shell layer of 1 layer or 2 layers or more which coat | covers the said core layer, It is any one of Claims 1-5 . Thermal barrier composition. In the core layer, the mass ratio of the content of the component (b2) to the content of the component (b1) ((b2) / (b1)) is 0.01 / 1 to 1/1.
In the outermost layer of the shell layer, the mass ratio of the content of the component (b2) to the content of the component (b1) ((b2) / (b1)) is 0.1 / 1 to 5/1. The heat-shielding composition according to claim 6 . The component (B) is a polymer emulsion particle obtained by polymerizing the component (b1) and the component (b2) in the polymerization stock solution containing seed particles that form the core layer.
The seed particles polymerize at least one component selected from the group consisting of the component (b1), the component (b2), and (b5) another vinyl monomer copolymerizable with the component (b2). The heat-shielding composition according to claim 6 or 7 , which is a particle obtained as described above. The heat-shielding composition according to any one of claims 3 to 8 , wherein the component (b2) is a vinyl monomer having a secondary amide group and / or a tertiary amide group. (C) component: It further includes one or more hydrolyzable silicon compounds selected from the group consisting of compounds represented by the following formulas (1), (2) and (3),
Wherein (A1) the relative content of the component (C) component mass ratio of the content of ((C) / (A1)) is 1 / 100-100 / 100, any one of the claims 1-9 The heat-shielding composition according to item.

R ¹ _n SiX _4-n (1)

(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 having 1 to 10 carbon atoms. Represents 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.)

X ₃ Si—R ² _n —SiX ₃ (2)

(In the formula (2), X represents a hydrolyzable group, R ² represents an alkylene group having 1 to 6 carbon atoms or a phenylene group. N is 0 or 1.)

R ³ — (O—Si (OR ³ ) ₂ ) _n —OR ³ (3)

(In the formula (3), R ³ is .n represents an alkyl group having 1 to 6 carbon atoms is an integer of 2-8.) (B) the number average particle diameter of component is 10 nm ~ 100 nm, the thermal barrier composition according to any one of claims 1-10. The heat shielding composition according to any one of claims 1 to 11 , wherein the component (A1) is colloidal silica having a number average particle diameter of 1 nm to 400 nm. The thermal insulation composition according to any one of claims 1 to 12 , wherein the component (A2) has an absorption of 0.1% or more in a wavelength region of a wavelength of 1000 nm to 2500 nm. A substrate;
A coating film formed by applying and drying the thermal barrier composition according to any one of claims 1 to 13 on the substrate;
A solar cell member comprising: The member for solar cells of Claim 14 which is a protection member of a solar cell. The member for solar cells according to claim 14 or 15 ,
A backsheet disposed opposite to the solar cell member;
A power generation element disposed between the solar cell member and the backsheet;
A solar cell comprising:

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