JP2011222749A - Wavelength conversion type solar battery sealing material, solar battery module using the same, and manufacturing method of the same - Google Patents

Abstract

Provided is a wavelength conversion type solar cell encapsulant capable of improving light utilization efficiency in a solar cell module and stably improving power generation efficiency.
A wavelength conversion solar cell encapsulant comprising: a phosphor, a coated phosphor containing a coating layer having a lower refractive index than that of the phosphor that coats the phosphor, and a sealing resin A composition layer is provided.
[Selection figure] None

Description

  The present invention relates to a wavelength conversion type solar cell encapsulant for a solar cell, a solar cell module using the same, and a manufacturing method thereof. More specifically, a solar cell module capable of increasing power generation efficiency by converting light in a wavelength region that does not contribute to power generation into light in a wavelength region that contributes to power generation, a wavelength conversion type solar cell sealing material used therefor, and these It is related with the manufacturing method.

  The conventional silicon crystal solar cell module has the following configuration. The protective glass on the surface (also referred to as cover glass) is made of tempered glass with a focus on impact resistance, and is in close contact with the sealing material (usually referred to as a resin or filler mainly composed of ethylene vinyl acetate copolymer). In order to improve the properties, one side has an uneven pattern by embossing.

Moreover, the uneven | corrugated pattern is formed inside, and the surface of a solar cell module is smooth. Moreover, the sealing material and back film for carrying out protection sealing of the photovoltaic cell and a tab wire are provided under the protective glass (for example, refer nonpatent literature 1).
A layer that emits light in a wavelength region that can contribute to power generation by converting the wavelength of light in the ultraviolet region or infrared region that does not contribute to power generation in a sunlight spectrum using a fluorescent substance (also referred to as a light emitting material) Many methods for providing the battery on the light receiving surface side have been proposed (see, for example, Patent Document 1).

In addition, a method for incorporating a rare earth complex, which is a fluorescent substance, in a sealing material has been proposed (see, for example, Patent Document 2).
Conventionally, ethylene-vinyl acetate copolymers imparted with thermosetting properties have been widely used as transparent sealing materials for solar cells (see, for example, Patent Document 3).

JP 2000-328053 A JP 2006-303033 A JP 2003-51605 A

Yasuhiro Sasakawa, “Solar Power Generation”-Latest Technology and System, 2000, CMC Corporation

  In the proposal for wavelength conversion of light that does not contribute to power generation described in Patent Document 1 to light in a wavelength region that can contribute to power generation, the wavelength conversion layer contains a fluorescent material, but this fluorescent material generally has a shape. When the incident sunlight passes through the wavelength conversion film, the ratio of not reaching the solar cells and contributing to power generation increases. As a result, there is a problem that even if the light in the ultraviolet region is converted into the light in the visible region in the wavelength conversion layer, the ratio of the electric power generated relative to the incident sunlight (power generation efficiency) is not so high.

  Further, in the method described in Patent Document 3, when a rare earth complex is used as a fluorescent material, it is easily hydrolyzed together with ethylene vinyl acetate (EVA) widely used as a sealing material, and the durability is not sufficient. In addition, it is difficult to efficiently introduce the wavelength-converted light into the solar battery cell.

  The present invention is intended to improve the above-described problems, and provides a wavelength conversion type solar cell encapsulant capable of improving light utilization efficiency in a solar cell module and stably improving power generation efficiency. Let's take this as an issue.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors, as a result, have a fluorescent material and a coated fluorescent material that has a coating layer that covers the periphery of the fluorescent material with a specific material having a lower refractive index than the fluorescent material. By using the body as a wavelength conversion type solar cell encapsulant, the light that does not contribute to solar power generation is converted into the wavelength that contributes to power generation in the incident sunlight, and at the same time, it is excellent in moisture resistance and heat resistance and is dispersed The present invention has been completed by finding that it has good performance and can be efficiently introduced into solar cells without scattering of the incident sunlight by the fluorescent material. Further, the resistance of the rare earth metal organic complex to humidity can be improved by this coating.

That is, the present invention is as follows.
<1> A light-transmitting resin composition layer containing a fluorescent substance, a coated phosphor including a coating layer having a refractive index lower than that of the fluorescent substance covering the fluorescent substance, and a sealing resin. Wavelength conversion type solar cell encapsulant.
<2> The wavelength-converting solar cell sealing material according to <1>, wherein the content of the coated phosphor in the resin composition layer is 0.0001 to 10 mass percent.
<3> The wavelength conversion solar cell sealing material according to <1> or <2>, wherein the coating layer contains a silica-based compound formed by a sol-gel method.

<4> The wavelength conversion solar cell sealing material according to any one of <1> to <3>, wherein the sealing resin is a non-hydrolyzable resin.
<5> The wavelength conversion solar cell according to any one of <1> to <4>, wherein the coated phosphor further includes a protective layer containing a moisture-resistant material on an outer surface of the coating layer. Sealing material.

<6> The wavelength conversion solar cell sealing material according to any one of <1> to <5>, further including a light-transmitting layer other than the resin composition layer.
<7> m layers composed of the resin composition layer and a light transmissive layer other than the resin composition layer, and the refractive indexes of the m layers are set to n _{1 in} order from the light incident side. , N ₂ ,..., N _(m−1) , n _m , wherein n ₁ ≦ n ₂ ≦... ≦ n _(m−1) ≦ _nm , Wavelength conversion type solar cell encapsulant.

<8> The wavelength conversion solar cell sealing material according to any one of <1> to <7>, wherein the fluorescent material is a europium complex.
<9> The wavelength conversion type solar cell sealing material according to any one of <4> to <8>, wherein the moisture-resistant material is a vinyl resin.

<10> A solar battery comprising a solar battery cell, and the wavelength conversion solar battery sealing material according to any one of <1> to <9>, which is disposed on a light receiving surface of the solar battery cell. module.
<11> A fluorescent material is coated with a silica-based material by a sol-gel reaction using silicon alkoxide to form a silica-based material layer on the surface of the fluorescent material, and the silica-based material layer is further coated with a vinyl resin. Wavelength conversion type solar cell sealing comprising: a fluorescent substance coating step for obtaining a phosphor; and a sheet forming step for forming a resin composition obtained by mixing or dispersing the coated phosphor in a sealing resin into a sheet shape A method of manufacturing the material.
<12> A fluorescent substance coating step of obtaining a coated phosphor by coating a fluorescent substance with a silica-based material by a sol-gel reaction using silicon alkoxide, and obtained by mixing or dispersing the coated phosphor in a non-hydrolyzable resin A method for producing a wavelength conversion type solar cell encapsulant comprising: a sheet forming step of forming a resin composition to be formed into a sheet shape.

<13> A method for producing a solar cell module having a plurality of light transmissive layers and solar cells, wherein the wavelength conversion solar cell encapsulant according to any one of <1> to <9> Is arranged on the light-receiving surface side of the solar battery cell, and a method for manufacturing a solar battery module including a step of forming one of the light transmissive layers.

  ADVANTAGE OF THE INVENTION According to this invention, the wavelength conversion type solar cell sealing material which can improve the light utilization efficiency in a solar cell module, and can improve electric power generation efficiency stably can be provided.

It is the schematic which shows an example of the relationship between content of the covering fluorescent substance concerning a present Example, and power generation efficiency.

<Wavelength conversion solar cell encapsulant and method for producing the same>
The wavelength conversion type solar cell encapsulant of the present invention contains a phosphor, a coated phosphor including a coating layer having a refractive index lower than that of the phosphor that coats the phosphor, and a sealing resin. A light transmissive resin composition layer is provided. With such a configuration, it is possible to improve the light utilization efficiency in the solar cell module and stably improve the power generation efficiency.
The wavelength conversion type solar cell encapsulant of the present invention is used, for example, as one of the light transmissive layers of a solar cell module having a plurality of light transmissive layers and solar cells. It is configured to include a substance having a refractive index lower than that of the fluorescent substance (hereinafter also referred to as “low refractive index coating material”), and is included as a coated phosphor having a coating layer that covers the periphery of the fluorescent substance. It is characterized by. Further, the coated phosphor is preferably dispersed in a sealing resin. In the present invention, the scattering loss of sunlight can be reduced by making the refractive index of the coated phosphor smaller than that of the fluorescent material.

  In a silicon crystal solar cell, for example, light having a wavelength shorter than 400 nm or shorter than 1200 nm is not effectively used in sunlight, and about 56% of solar energy does not contribute to power generation due to this spectrum mismatch. The present invention uses a fluorescent material having a specific shape with excellent moisture resistance and heat resistance, good dispersibility, and suppressed concentration quenching, wavelength conversion, and efficient and stable use of sunlight. It is to overcome the mismatch.

  That is, the wavelength conversion type solar cell encapsulant of the present invention contains a fluorescent material that is excellent in moisture resistance and heat resistance, has good dispersibility, and does not cause concentration quenching. Further, the wavelength conversion type solar cell encapsulant of the present invention converts the light that does not contribute to solar power generation into the wavelength that contributes to power generation in the incident sunlight, and at the same time, without scattering the light, It can be efficiently introduced into the cell.

  In general, the refractive index of a fluorescent material is a value unique to the material, and it is difficult to achieve both high luminous efficiency and low refractive index. Therefore, the scattering loss of sunlight can be reduced by coating the periphery of the fluorescent material with a layer of a specific material (low refractive index coating material) having a lower refractive index than the fluorescent material.

(Low refractive index coating material)
The coated phosphor in the present invention includes a fluorescent material and a coating layer that covers the fluorescent material and has a refractive index lower than that of the fluorescent material. That is, the coated phosphor includes a fluorescent material coated with a coating layer including a low refractive index coating material.
The refractive index of the low-refractive index coating material is lower than that of the fluorescent substance, but more preferably has a ratio close to “1” with the refractive index of the sealing resin described later. The refractive index of the sealing resin is generally 1.4 to 1.7, while the refractive index of the fluorescent material is generally higher than 1.5. Therefore, a material having a refractive index of 1.4 to 1.5 may be used as the low refractive index coating material. Such a low refractive index coating material will be described later.

  By coating the fluorescent material with a specific low refractive index coating material, the moisture resistance and heat resistance of the fluorescent material are improved, the dispersibility is good and concentration quenching is suppressed, and the refractive index of the coated phosphor is reduced. This can reduce the scattering loss of sunlight.

  Further, the scattering can be reduced by making the refractive index of the low refractive index coating material close to the refractive index of the sealing resin as a dispersion medium. Moreover, the loss of sunlight due to scattering can be further reduced by reducing the particle diameter of the coated phosphor.

  The scattering of light correlates with the coating phosphor in the sealing material, that is, the refractive index ratio between the coating layer and the sealing resin, and the particle size of the coating phosphor. Specifically, if the ratio of the refractive index of the coating layer to the refractive index of the sealing resin is close to “1”, the light scattering is not significantly affected by the particle diameter of the coated phosphor, and the light scattering Will also be small. However, if the ratio between the refractive index of the coating layer and the refractive index of the sealing resin increases, light scattering is affected by the size of the particle diameter of the coated phosphor. Preferably there is.

  Moreover, there is no restriction | limiting in particular as a coating amount of the low-refractive-index coating material which coat | covers a fluorescent substance, However, It is preferable that it is 1 to 10000 times on a mass basis with respect to a fluorescent substance, and is 100 to 10000 times. It is more preferable.

The low refractive index material is not particularly limited as long as it has a lower refractive index than the fluorescent material, and can be appropriately selected according to the fluorescent material. Specific examples include a silica-based material formed by a sol-gel method (hereinafter also referred to as “sol-gel glass” or simply “glass”), a vinyl resin, and the like. In the present invention, a silica-based material formed by a sol-gel method is preferable.
The properties of the coated phosphor may be solid particles or a liquid in which fine particle colloids of the fluorescent material are dispersed when dispersed in the sealing resin.

A fluorescent material sealed with sol-gel glass can be obtained, for example, by forming a silica-based material on the surface of the fluorescent material by a sol-gel method using silicon alkoxide. Details will be described later.
As the coating for reducing the effective refractive index, it is preferable to use the above-described silica-based material. However, in particular, when the fluorescent material is a metal complex, this alone may not provide sufficient moisture resistance. In a general solar cell module, an ethylene-vinyl acetate copolymer (EVA) that is typically used as a sealing resin can undergo hydrolysis under high temperature and high humidity to generate a free acid. This acid may promote deterioration of the metal complex. Therefore, it is desirable to further coat the coated phosphor with a transparent material having good moisture resistance or to disperse it in a non-hydrolyzable medium resin, that is, a non-hydrolyzable resin having a sealing function.

(Fluorescent substance)
The fluorescent substance used in the present invention is not particularly limited as long as it is a compound that can convert light outside the wavelength range that can be used in a normal solar cell into a wavelength range that can be used in a solar cell. For example, an organic complex of rare earth metal can be preferably mentioned. Among these, from the viewpoint of wavelength conversion efficiency, at least one of a europium complex and a samarium complex is preferable.
Moreover, there is no restriction | limiting in particular as a ligand which comprises an organic complex, According to the metal to be used, it can select suitably. Among these, a ligand capable of forming a complex with at least one of europium and samarium is preferable.

In the present invention, although the ligand is not limited, the neutral ligand is selected from carboxylic acid, nitrogen-containing organic compound, nitrogen-containing aromatic heterocyclic compound, β-diketone, and phosphine oxide. It is preferable that it is at least one kind.
In addition, as a ligand of the rare earth complex, a general formula R ¹ COCHR ² COR ³ (wherein R ¹ represents an aryl group, an alkyl group, a cycloalkyl group, a cycloalkylalkyl group, an aralkyl group, or a substituent thereof, R ² Represents a hydrogen atom, an alkyl group, a cycloalkyl group, a cycloalkylalkyl group, an aralkyl group or an aryl group, and R ³ represents an aryl group, an alkyl group, a cycloalkyl group, a cycloalkylalkyl group, an aralkyl group or a substituent thereof. (Beta) -diketone represented by this may be contained.

  Specific examples of β-diketones include acetylacetone, perfluoroacetylacetone, benzoyl-2-furanoylmethane, 1,3-di (3-pyridyl) -1,3-propanedione, benzoyltrifluoroacetone, and benzoylacetone. , 5-chlorosulfonyl-2-thenoyltrifluoroacetone, bis (4-bromobenzoyl) methane, dibenzoylmethane, d, d-dicamphorylmethane, 1,3-dicyano-1,3-propanedione, p- Bis (4,4,5,5,6,6,6-heptafluoro-1,3-hexanedinoyl) benzene, 4,4'-dimethoxydibenzoylmethane, 2,6-dimethyl-3,5-heptane Dione, dinaphthoylmethane, dipivaloylmethane, bis (perfluoro-2-propoxypropionyl) Tan, 1,3-di (2-thienyl) -1,3-propanedione, 3- (trifluoroacetyl) -d-camphor, 6,6,6-trifluoro-2,2-dimethyl-3,5 -Hexanedione, 1,1,1,2,2,6,6,7,7,7-decafluoro-3,5-heptanedione, 6,6,7,7,8,8,8-heptafluoro -2,2-dimethyl-3,5-octanedione, 2-furyltrifluoroacetone, hexafluoroacetylacetone, 3- (heptafluorobutyryl) -d-camphor, 4,4,5,5,6,6 6-heptafluoro-1- (2-thienyl) -1,3-hexanedione, 4-methoxydibenzoylmethane, 4-methoxybenzoyl-2-furanoylmethane, 6-methyl-2,4-heptanedione, 2 -Naftoil Fluoroacetone, 2- (2-pyridyl) benzimidazole, 5,6-dihydroxy-1,10-phenanthroline, 1-phenyl-3-methyl-4-benzoyl-5-pyrazole, 1-phenyl-3-methyl-4 -(4-butylbenzoyl) -5-pyrazole, 1-phenyl-3-methyl-4-isobutyryl-5-pyrazole, 1-phenyl-3-methyl-4-trifluoroacetyl-5-pyrazole, 3- (5 -Phenyl-1,3,4-oxadiazol-2-yl) -2,4-pentanedione, 3-phenyl-2,4-pentanedione, 3- [3 ', 5'-bis (phenylmethoxy) Phenyl] -1- (9-phenanthyl) -1-propane-1,3-dione, 5,5-dimethyl-1,1,1-trifluoro-2,4-hexanedione, 1-phenyl-3- (2-thienyl) -1,3-propanedione, 3- (t-butylhydroxymethylene) -d-camphor, 1,1,1-trifluoro-2,4-pentanedione, 1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluoro-4,6-nonanedione, 2,2,6,6-tetramethyl-3, 5-heptanedione, 4,4,4-trifluoro-1- (2-naphthyl) -1,3-butanedione, 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione, 2,2,6,6-tetramethyl-3,5-heptanedione, 2,2,6,6-tetramethyl-3,5-octanedione, 2,2,6-trimethyl-3,5-heptanedione 2,2,7-trimethyl-3,5-octanedione, 4,4, -Trifluoro-1- (thienyl) -1,3-butanedione (TTA), 1,3-diphenyl-1,3-propanedione, benzoylacetone, dibenzoylacetone, diisobutyroylmethane, dibipalo Ilmethane, 3-methylpentane-2,4-dione, 2,2-dimethylpentane-3,5-dione, 2-methyl-1,3-butanedione, 1,3-butanedione, 3-phenyl-2,4 -Pentanedione, 1,1,1-trifluoro-2,4-pentanedione, 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione, 2,2,6,6-tetramethyl -3,5-heptanedione, 3-methyl-2,4-pentanedione, 2-acetylcyclopentanone, 2-acetylcyclohexanone, 1-heptafluoropropyl-3-t Butyl-1,3-propane dione, 1,3-diphenyl-2-methyl-1,3-propane dione, or 1-ethoxy-1,3-butanedione, and the like.

  Nitrogen-containing organic compounds, nitrogen-containing aromatic heterocyclic compounds, and phosphine oxides of neutral ligands of rare earth complexes include, for example, 1,10-phenanthroline, 2-2'-bipyridyl, 2-2'-6, 2 "-terpyridyl, 4,7-diphenyl-1,10-phenanthroline, 2- (2-pyridyl) benzimidazole, triphenylphosphine oxide, tri-n-butylphosphine oxide, tri-n-octylphosphine oxide, tri- Examples include n-butyl phosphate.

As the rare earth complex having the above ligand, for example, Eu (TTA) ₃ phen can be preferably used from the viewpoint of wavelength conversion efficiency.
A method for producing Eu (TTA) ₃ Phen is described, for example, in Masa Mitsui, Shinji Kikuchi, Tokuji Miyashita, Yutaka Amano, J. et al. Mater. Chem. Reference may be made to the method disclosed in 2003, 13, 285-2879.

  In the present invention, a solar cell module having high power generation efficiency can be configured by using a europium complex as the fluorescent material. The europium complex converts light in the ultraviolet region into light in the red wavelength region with high wavelength conversion efficiency, and the converted light contributes to power generation in the solar battery cell.

(Silica-based material)
The method of coating the fluorescent material with the silica-based material by the sol-gel method is not particularly limited as long as it is a known method, but can be performed by treating the fluorescent material with silicon alkoxide in a solvent and heat-treating. .

  Examples of the silicon alkoxide used in the sol-gel method include tetraalkoxysilane, trialkoxysilane, and diorganodialkoxysilane.

  Examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert-butoxysilane. And tetraphenoxysilane.

Moreover, the compound like following formula (1) by which the alkoxy group was substituted by the alkyl group may be sufficient.
R ¹ _n SiX _4-n (1)
In the above formula, R ¹ represents an H atom or an organic group having 1 to 20 carbon atoms, X represents a hydrolyzable group, n represents an integer of 0 to 2, and when n is 2, each R ¹ may be the same or different. When n is 0 to 2, each X may be the same or different.
Examples of the organic group having 1 to 20 carbon atoms include linear or branched alkyl groups having 1 to 20 carbon atoms. Moreover, hydrogen of the alkyl group may be substituted with a group containing fluorine, Si atom, or the like.
Moreover, as a hydrolysable group, a C1-C20 alkoxy group is mentioned.

  Examples of the trialkoxysilane include trimethoxysilane, triethoxysilane, tripropoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, and methyltri-iso. -Propoxysilane, methyltri-n-butoxysilane, methyltri-iso-butoxysilane, methyltri-tert-butoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltri-iso -Propoxysilane, ethyltri-n-butoxysilane, ethyltri-iso-butoxysilane, ethyltri-tert-butoxysilane, ethyltriphenoxy N-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltri-n-propoxysilane, n-propyltri-iso-propoxysilane, n-propyltri-n-butoxysilane, n-propyltri -Iso-butoxysilane, n-propyltri-tert-butoxysilane, n-propyltriphenoxysilane, iso-propyltrimethoxysilane, iso-propyltriethoxysilane, iso-propyltri-n-propoxysilane, iso-propyl Tri-iso-propoxysilane, iso-propyltri-n-butoxysilane, iso-propyltri-iso-butoxysilane, iso-propyltri-tert-butoxysilane, iso-propyltriphenoxysilane, n-butyltrimethyl Xylsilane, n-butyltriethoxysilane, n-butyltri-n-propoxysilane, n-butyltri-iso-propoxysilane, n-butyltri-n-butoxysilane, n-butyltri-iso-butoxysilane, n-butyltri-tert -Butoxysilane, n-butyltriphenoxysilane, sec-butyltrimethoxysilane, sec-butyltriethoxysilane, sec-butyltri-n-propoxysilane, sec-butyltri-iso-propoxysilane, sec-butyltri-n-butoxy Silane, sec-butyltri-iso-butoxysilane, sec-butyltri-tert-butoxysilane, sec-butyltriphenoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, t-butylto Ri-n-propoxysilane, t-butyltri-iso-propoxysilane, t-butyltri-n-butoxysilane, t-butyltri-iso-butoxysilane, t-butyltri-tert-butoxysilane, t-butyltriphenoxysilane, Phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-iso-propoxysilane, phenyltri-n-butoxysilane, phenyltri-iso-butoxysilane, phenyltri-tert-butoxysilane, Phenyltriphenoxysilane, trifluoromethyltrimethoxysilane, pentafluoroethyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxy Run, and the like.

  Examples of the diorganodialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-propoxysilane, dimethyldi-iso-propoxysilane, dimethyldi-n-butoxysilane, dimethyldi-sec-butoxysilane, and dimethyldi-tert. -Butoxysilane, dimethyldiphenoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldi-n-propoxysilane, diethyldi-iso-propoxysilane, diethyldi-n-butoxysilane, diethyldi-sec-butoxysilane, diethyldi-tert- Butoxysilane, diethyldiphenoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-n-propyldi-n-propoxy Di-n-propyldi-iso-propoxysilane, di-n-propyldi-n-butoxysilane, di-n-propyldi-sec-butoxysilane, di-n-propyldi-tert-butoxysilane, di-n- Propyl diphenoxy silane, di-iso-propyl dimethoxy silane, di-iso-propyl diethoxy silane, di-iso-propyl di-n-propoxy silane, di-iso-propyl di-iso-propoxy silane, di-iso-propyl di- n-butoxysilane, di-iso-propyldi-sec-butoxysilane, di-iso-propyldi-tert-butoxysilane, di-iso-propyldiphenoxysilane, di-n-butyldimethoxysilane, di-n-butyldi Ethoxysilane, di-n-butyldi-n-propoxy Silane, di-n-butyldi-iso-propoxysilane, di-n-butyldi-n-butoxysilane, di-n-butyldi-sec-butoxysilane, di-n-butyldi-tert-butoxysilane, di-n- Butyldiphenoxysilane, di-sec-butyldimethoxysilane, di-sec-butyldiethoxysilane, di-sec-butyldi-n-propoxysilane, di-sec-butyldi-iso-propoxysilane, di-sec-butyldi- n-butoxysilane, di-sec-butyldi-sec-butoxysilane, di-sec-butyldi-tert-butoxysilane, di-sec-butyldiphenoxysilane, di-tert-butyldimethoxysilane, di-tert-butyldi Ethoxysilane, di-tert-butyldi-n-propoxysila Di-tert-butyldi-iso-propoxysilane, di-tert-butyldi-n-butoxysilane, di-tert-butyldi-sec-butoxysilane, di-tert-butyldi-tert-butoxysilane, di-tert- Butyldiphenoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldi-n-propoxysilane, diphenyldi-iso-propoxysilane, diphenyldi-n-butoxysilane, diphenyldi-sec-butoxysilane, diphenyldi-tert -Butoxysilane, diphenyldiphenoxysilane, bis (3,3,3-trifluoropropyl) dimethoxysilane, methyl (3,3,3-trifluoropropyl) dimethoxysilane and the like.

In the general formula (1), a compound wherein R ¹ is an organic group having 1 to 20 carbon atoms, and compounds other than the above, for example, bis (trimethoxysilyl) methane, bis (triethoxysilyl) methane Bis (tri-n-propoxysilyl) methane, bis (tri-iso-propoxysilyl) methane, bis (trimethoxysilyl) ethane, bis (triethoxysilyl) ethane, bis (tri-n-propoxysilyl) ethane, Bis (tri-iso-propoxysilyl) ethane, bis (trimethoxysilyl) propane, bis (triethoxysilyl) propane, bis (tri-n-propoxysilyl) propane, bis (tri-iso-propoxysilyl) propane, bis (Trimethoxysilyl) benzene, bis (triethoxysilyl) benzene, bis (to Examples thereof include bissilylalkanes such as (ri-n-propoxysilyl) benzene and bis (tri-iso-propoxysilyl) benzene, and bissilylbenzene.

In the general formula (1), examples of the compound in which R ¹ is a group containing a Si atom include hexamethoxydisilane, hexaethoxydisilane, hexa-n-propoxydisilane, and hexa-iso-propoxydisilane. Examples thereof include dialkyltetraalkoxydisilanes such as alkoxydisilanes, 1,2-dimethyltetramethoxydisilane, 1,2-dimethyltetraethoxydisilane, and 1,2-dimethyltetrapropoxydisilane.

The solvent used in the sol-gel method only needs to be able to dissolve the silicon alkoxide component used in the sol-gel method. For example, a mixed solution of water and an organic solvent is used.
The organic solvent capable of dissolving the silicon alkoxide component used in the sol-gel method may be an aprotic solvent or a protic solvent. These may be used alone or in combination of two or more.

  Examples of the aprotic solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-iso-propyl ketone, methyl-n-butyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, methyl-n- Hexyl ketone, diethyl ketone, dipropyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentanedione, acetonyl acetone, γ-butyrolactone, γ-valerolactone, etc. Ketone solvents;

  Diethyl ether, methyl ethyl ether, methyl-n-di-n-propyl ether, di-iso-propyl ether, tetrahydrofuran, methyltetrahydrofuran, dioxane, dimethyl dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n- Propyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl mono-n-propyl ether, diethylene glycol methyl mono-n-butyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n- Butyl ether, diethylene glycol Methyl methyl mono-n-hexyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol methyl ethyl ether, triethylene glycol methyl mono-n-butyl ether, triethylene glycol di-n-butyl ether, triethylene glycol methyl mono- n-hexyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetradiethylene glycol methyl ethyl ether, tetraethylene glycol methyl mono-n-butyl ether, diethylene glycol di-n-butyl ether, tetraethylene glycol methyl mono-n-hexyl ether, Tetraethylene glycol di-n-butyl ether, propylene Glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether, propylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol methyl mono-n-butyl ether, Dipropylene glycol di-n-propyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol methyl mono-n-hexyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol methyl ethyl ether, tripropylene Glycol methyl mono-n-butyl ether, Ripropylene glycol di-n-butyl ether, tripropylene glycol methyl mono-n-hexyl ether, tetrapropylene glycol dimethyl ether, tetrapropylene glycol diethyl ether, tetradipropylene glycol methyl ethyl ether, tetrapropylene glycol methyl mono-n-butyl ether, di Ether solvents such as propylene glycol di-n-butyl ether, tetrapropylene glycol methyl mono-n-hexyl ether, tetrapropylene glycol di-n-butyl ether;

  Methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, nonyl acetate, methyl acetoacetate, ethyl acetoacetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether , Dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyrate propionate , Propionic acid i- amyl, diethyl oxalate, ester solvents such as oxalic di -n- butyl;

  Ethylene glycol methyl ether propionate, ethylene glycol ethyl ether propionate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol-n-butyl ether acetate, propylene glycol methyl ether acetate Ether acetate solvents such as propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate;

Halogen solvents such as dichloromethane and chloroform;
Hydrocarbon solvents such as benzene, toluene, xylene;

  Acetonitrile, N-methylpyrrolidinone, N-ethylpyrrolidinone, N-propylpyrrolidinone, N-butylpyrrolidinone, N-hexylpyrrolidinone, N-cyclohexylpyrrolidinone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N- Dimethyl sulfoxide etc. are mentioned, These are used individually by 1 type or in combination of 2 or more types.

  Examples of protic solvents include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, and 2-methylbutanol. , Sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, n-octanol, 2-ethylhexanol, sec- Octanol, n-nonyl alcohol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexano Le, benzyl alcohol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, alcohol solvents such as tripropylene glycol;

Ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol mono-n -Ether solvents such as butyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether;
Examples include ester solvents such as methyl lactate, ethyl lactate, n-butyl lactate, and n-amyl lactate, and alcohol solvents are preferred from the viewpoint of storage stability. Among these, ethanol, isopropyl alcohol, propylene glycol propyl ether and the like are preferable from the viewpoint of suppressing coating unevenness and repellency. These are used singly or in combination of two or more.

  In the sol-gel reaction, a catalyst may be appropriately used. The catalyst used is preferably an onium salt from the viewpoint that the mechanical strength of the resulting coating layer made of the silica-based material can be improved and the stability of the composition can be increased, and is preferably a quaternary ammonium salt. More preferred.

  As one of the onium salt compounds, for example, a salt formed from a nitrogen-containing compound and at least one selected from an anionic group-containing compound and a halogen atom can be given. The atom bonded to nitrogen of the nitrogen-containing compound is at least selected from the group consisting of H atom, F atom, B atom, N atom, Al atom, P atom, Si atom, Ge atom, Ti atom, and C atom. One type is preferable. Examples of the anionic group include a hydroxyl group, a nitrate group, a sulfate group, a carbonyl group, a carboxyl group, a carbonate group, and a phenoxy group.

  Examples of these onium salt compounds include ammonium hydroxide, ammonium fluoride, ammonium chloride, ammonium bromide, ammonium iodide, ammonium phosphate, ammonium nitrate, ammonium borate, ammonium sulfate, ammonium formate, and ammonium maleate. , Ammonium fumarate, ammonium phthalate, ammonium malonate, ammonium succinate, ammonium tartrate, ammonium malate, ammonium lactate, ammonium citrate, ammonium acetate, ammonium propionate, butanoic acid Ammonium salt, ammonium pentanoate, ammonium hexanoate, ammonium heptanoate, ammonium octanoate, ammonium nonanoate Nium salt, ammonium decanoate, ammonium oxalate, ammonium adipate, ammonium sebacate, ammonium butyrate, ammonium oleate, ammonium stearate, ammonium linoleate, ammonium linolenate, ammonium salicylate Benzenesulfonic acid ammonium salt, benzoic acid ammonium salt, p-aminobenzoic acid ammonium salt, p-toluenesulfonic acid ammonium salt, methanesulfonic acid ammonium salt, trifluoromethanesulfonic acid ammonium salt, trifluoroethanesulfonic acid ammonium salt, etc. An ammonium salt compound is mentioned.

  In addition, the ammonium moiety of the ammonium salt compound is methylammonium, dimethylammonium, trimethylammonium, tetramethylammonium, ethylammonium, diethylammonium, triethylammonium, tetraethylammonium, propylammonium, dipropylammonium, tripropylammonium, tetrapropylammonium, Examples also include ammonium salt compounds substituted with butylammonium, dibutylammonium, tributylammonium, tetrabutylammonium, ethanolammonium, diethanolammonium, triethanolammonium, and the like.

  In these onium salt compounds, tetramethylammonium nitrate, tetramethylammonium acetate, tetramethylammonium propionate, tetramethylammonium maleate, tetramethylammonium sulfate from the viewpoint of accelerating the curing of the coating layer made of a silica-based material. Ammonium salts such as salts are preferred. These are used singly or in combination of two or more.

(Moisture resistant material)
In the present invention, a fluorescent material coated with a low refractive index material (preferably a fluorescent material coated with a silica-based material by a sol-gel method) is formed on the outer surface of the coating layer containing the low refractive index material. It is preferable to further have a protective layer containing. That is, in the coated phosphor, it is preferable that the coating layer containing the low refractive index material covers the fluorescent material, and the outer surface thereof is further coated with a water resistant material. Thereby, the moisture resistance stability of the wavelength conversion type solar cell encapsulant can be further improved.
The moisture resistant material is not particularly limited as long as it is hydrophobic and water-insoluble, and examples thereof include vinyl resins (including acrylic resins and methacrylic resins) described later.

  In the present invention, the refractive index of the moisture resistant material is not particularly limited, but the refractive index is preferably lower or equivalent to that of the low refractive index material covering the fluorescent material. More preferably, it is higher than or equal to the refractive index. Thereby, light scattering in the coated phosphor can be more effectively suppressed, and the power generation efficiency can be further improved.

Examples of a method of further covering the fluorescent material coated with the low refractive index material with the water resistant material include, for example, a method of encapsulating the fluorescent material coated with the low refractive index material in the particles composed of the water resistant material, Examples thereof include a method of attaching a water-resistant material layer to the surface of a fluorescent material coated with a low refractive index material.
In the present invention, the method is preferably a method in which a fluorescent material coated with a low refractive index material is encapsulated in particles composed of a water-resistant material, and a phosphor material coated with a silica-based material is encapsulated in resin particles. More preferred is a method of encapsulating a fluorescent material coated with a silica-based material by a sol-gel method in a vinyl resin particle, and still more preferred.

  When the fluorescent material coated with a low refractive index material is further coated with a water resistant material, the amount of the coating is not particularly limited, but for the fluorescent material fluorescent material coated with the low refractive index material, 1 to It is preferably 10,000 times, more preferably 10 to 400 times.

In the present invention, the fluorescent material is preferably coated with sol-gel glass and further encapsulated in resin particles. Although there is no restriction | limiting in particular as a monomer compound which comprises the said resin particle, From a viewpoint of scattering suppression of light, it is preferable that it is a vinyl compound.
In addition, as a method of encapsulating the fluorescent substance in the resin particles, a commonly used method can be used without any particular limitation. For example, it can be prepared by preparing a mixture of monomer compounds constituting the fluorescent substance and resin particles and polymerizing the mixture. Specifically, for example, a mixture containing a sol-gel glass-coated fluorescent substance and a vinyl compound was prepared, and the vinyl compound was polymerized using a radical polymerization initiator, whereby the sol-gel glass-coated fluorescent substance was included. A wavelength conversion fluorescent material can be formed as the resin particles.

(Vinyl compound)
In the present invention, the vinyl compound is not particularly limited as long as it is a compound having at least one ethylenically unsaturated bond, and an acrylic monomer, a methacrylic monomer, which can be converted into a vinyl resin, particularly an acrylic resin or a methacrylic resin when polymerized. An acrylic oligomer, a methacryl oligomer, etc. can be used without a restriction | limiting in particular. In the present invention, an acrylic monomer, a methacryl monomer, and the like are preferable.

  Examples of the acrylic monomer and the methacrylic monomer include acrylic acid, methacrylic acid, and alkyl esters thereof, and other vinyl compounds that can be copolymerized with these may be used in combination. A combination of the above can also be used.

  Examples of the alkyl acrylate ester and the alkyl methacrylate ester include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate. Acrylic acid unsubstituted alkyl ester and methacrylic acid unsubstituted alkyl ester; dicyclopentenyl (meth) acrylate; tetrahydrofurfuryl (meth) acrylate; benzyl (meth) acrylate; α, β-unsaturated carboxylic acid to polyhydric alcohol (For example, polyethylene glycol di (meth) acrylate (having 2 to 14 ethylene groups), trimethylolpropane di (meth) acrylate, trimethylolpropylene) N-tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, trimethylolpropane propoxytri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, polypropylene glycol di (meth) Acrylate (having 2 to 14 propylene groups), dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, bisphenol A polyoxyethylene di (meth) acrylate, bisphenol A dioxyethylene di ( Meth) acrylate, bisphenol A trioxyethylene di (meth) acrylate, bisphenol A decaoxyethylene di (meth) acrylate, etc.); Compounds obtained by adding an α, β-unsaturated carboxylic acid to a group-containing compound (for example, trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether diacrylate, etc.); a polyvalent carboxylic acid (for example, phthalic anhydride) Acid) and a substance having a hydroxyl group and an ethylenically unsaturated group (for example, β-hydroxyethyl (meth) acrylate); acrylic acid or alkyl ester of methacrylic acid (for example, (meth) acrylic acid methyl ester, ( (Meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2-ethylhexyl ester); urethane (meth) acrylate (eg, tolylene diisocyanate and 2-hydroxyethyl (meth) acrylic ester) reaction A reaction product of trimethylhexamethylene diisocyanate, cyclohexanedimethanol and 2-hydroxyethyl (meth) acrylic acid ester); an acrylic acid-substituted alkyl ester or a methacrylic acid in which a hydroxyl group, an epoxy group, a halogen group or the like is substituted on these alkyl groups Acid-substituted alkyl ester; and the like.

  Examples of other vinyl compounds that can be copolymerized with acrylic acid, methacrylic acid, alkyl acrylate ester, or alkyl methacrylate ester include acrylamide, acrylonitrile, diacetone acrylamide, styrene, vinyl toluene, and the like. These vinyl monomers can be used alone or in combination of two or more.

  The vinyl compound in the present invention is preferably appropriately selected so that the refractive index of the resin particles to be formed has a desired value, and at least one selected from alkyl acrylates and alkyl methacrylates is used. preferable.

(Radical polymerization initiator)
In the present invention, it is preferable to use a radical polymerization initiator in order to polymerize the vinyl compound. As the radical polymerization initiator, a commonly used radical polymerization initiator can be used without particular limitation. For example, a peroxide etc. are mentioned preferably. Specifically, organic peroxides or azo radical initiators that generate free radicals by heat are preferred.
Examples of the organic oxide include isobutyl peroxide, α, α′bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, di-n-propylperoxydicarbonate, bis-s-butyl. Peroxydicarbonate, 1,1,3,3-tetramethylbutylneodecanoate, bis (4-t-butylcyclohexyl) peroxydicarbonate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, Bis-2-ethoxyethyl peroxydicarbonate, bis (ethylhexylperoxy) dicarbonate, t-hexyl neodecanoate, bismethoxybutyl peroxydicarbonate, bis (3-methyl-3-methoxybutylperoxy) di Carbonate, t-butyl peroxy Neodecanoate, t-hexylperoxypivalate, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2 -Ethylhexanoate, succinic peroxide, 2,5-dimethyl-2,5-bis (2-ethylhexanoyl) hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t -Hexylperoxy-2-ethylhexanoate, 4-methylbenzoyl peroxide, t-butylperoxy-2-ethylhexanoate, m-toluonoylbenzoyl peroxide, benzoyl peroxide, t-butylperoxyiso Butyrate, 1,1 -Bis (t-butylperoxy) 2-methylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexanone, 2,2-bis (4,4-dibutylperoxycyclohexyl) ) Propane, 1,1-bis (t-butylperoxy) cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexano Ate, t-butyl peroxylaurate, 2,5-dimethyl-2,5-bis (m-toluoyl peroxy) ) Hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t -Butylperoxyacetate, 2,2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl-4,4-bis (t-butylperoxy) valerate, di-t-butyl Peroxyisophthalate, α, α′bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumylper Oxide, di-t-butylperoxy, p-menthane hydroperoxide 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene Hydroperoxide, t-hexyl hydroperoxide, t-butyl hydroperoxide, 2,3-dimethyl-2,3-diphenylbutane, and the like can be used.

  Examples of the azo radical initiator include azobisisobutyronitrile (AIBN, trade name V-60, manufactured by Wako Pure Chemical Industries), 2,2′-azobis (2-methylisobutyronitrile) (trade name). V-59, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2′-azobis (2,4-dimethylvaleronitrile) (trade name V-65, manufactured by Wako Pure Chemical Industries, Ltd.), dimethyl-2,2′-azobis (isobutyrate) ) (Trade name V-601, manufactured by Wako Pure Chemical Industries, Ltd.), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (trade name V-70, manufactured by Wako Pure Chemical Industries, Ltd.), and the like. It is done.

  The usage-amount of a radical polymerization initiator can be suitably selected according to the kind of said vinyl compound, the refractive index of the resin particle formed, etc., and is used by the usage-amount normally used. Specifically, for example, it can be used at 0.01 to 2% by weight, preferably 0.1 to 1% by weight, based on the vinyl compound.

  Note that the confirmation that the coating layer is formed around the fluorescent material is indirect, but, for example, the high temperature and high humidity resistance is measured under the conditions of 85 ° C. and 85% RH, and the high temperature of the fluorescent material before the coating layer is formed. This can be judged by the presence or absence of improvement in high humidity resistance.

The coated phosphor in the present invention can be controlled in its desired form, such as solid particles, liquid, film, etc., by the silicon alkoxide component and preparation method, and the resin coating component and preparation method.
For example, when the coated phosphor is configured in the form of solid particles, the particle diameter can be 1 to 1000 μm.

  The preferable compounding amount of the coated phosphor in the resin composition for wavelength conversion type solar cell encapsulant of the present invention is 0.0001 to 10 in mass concentration of the fluorescent substance (preferably europium complex) with respect to the total nonvolatile content. Mass% is preferred. Issuing efficiency improves by setting it as 0.0001 mass% or more. Moreover, the fall of the luminous efficiency by concentration quenching is suppressed by setting it as 10 mass% or less. Moreover, scattering of incident light can be more effectively suppressed.

(Sealing resin)
The resin composition layer in the present invention contains at least one sealing resin. As the sealing resin of the resin composition, a photocurable resin, a thermosetting resin, a thermoplastic resin, or the like is preferably used.
Conventionally, as a resin used as a transparent sealing material for solar cells, an ethylene-vinyl acetate copolymer (EVA) imparted with thermosetting properties has been widely used. In the first aspect of the present invention, that is, in the aspect in which a fluorescent material such as a sol-gel glass-sealed rare earth metal complex is further sealed with a moisture-resistant material (preferably, a transparent resin), the sealing resin also serving as a dispersion medium The thermoplastic resin, the thermosetting resin, and the photocurable resin can be used together.

On the other hand, in the second aspect of the present invention, that is, in an aspect in which a fluorescent material such as a sol-gel glass-sealed rare earth metal complex is not further sealed with a moisture-resistant material, the sealing resin may be a non-hydrolyzable resin. preferable. The non-hydrolyzable resin means one that does not hydrolyze to generate free acid or base.
Examples of the non-hydrolyzable resin in the present invention include an ethylene- (meth) acrylic ester resin.

  When using a photocurable resin for the dispersion medium resin (encapsulating resin) of the resin composition for wavelength conversion type solar cell encapsulant, the resin configuration and photocuring method of the photocurable resin are not particularly limited. For example, in the photocuring method using a photoradical initiator, the wavelength-converting solar cell encapsulant resin composition includes (A) a photocurable resin, (B) a crosslinkable monomer, and (C ) A dispersion medium resin containing a photoinitiator that generates free radicals by light.

  Here, as the photocurable resin (A), a copolymer obtained by copolymerizing acrylic acid or methacrylic acid and an alkyl ester thereof and another vinyl monomer copolymerizable therewith as a constituent monomer is used. These copolymers can be used alone or in combination of two or more. Examples of the alkyl acrylate ester or alkyl methacrylate ester include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and the like. Acrylic acid unsubstituted alkyl ester or methacrylic acid unsubstituted alkyl ester, acrylic acid substituted alkyl ester or methacrylic acid substituted alkyl ester in which a hydroxyl group, an epoxy group, a halogen group or the like is substituted on these alkyl groups.

  Examples of other vinyl monomers that can be copolymerized with acrylic acid, methacrylic acid, alkyl acrylate ester, or alkyl methacrylate ester include acrylamide, acrylonitrile, diacetone acrylamide, styrene, vinyl toluene, and the like. These vinyl monomers can be used alone or in combination of two or more. Moreover, it is preferable that the weight average molecular weight of the dispersion medium resin of (A) component is 10,000-300,000 from the point of coating-film property and coating-film intensity | strength.

  (B) As the crosslinkable monomer, for example, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid (for example, polyethylene glycol di (meth) acrylate (the number of ethylene groups is 2 to 14). ), Trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, trimethylolpropane propoxytri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, Tetramethylolmethane tetra (meth) acrylate, polypropylene glycol di (meth) acrylate (having 2 to 14 propylene groups), dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate, bisphenol A polyoxyethylene di (meth) acrylate, bisphenol A dioxyethylene di (meth) acrylate, bisphenol A trioxyethylene di (meth) acrylate, bisphenol A deoxyoxyethylene di (meth) acrylate, etc.]; glycidyl Compounds obtained by adding an α, β-unsaturated carboxylic acid to a group-containing compound (for example, trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether diacrylate, etc.); a polyvalent carboxylic acid (for example, phthalic anhydride) Acid) and an esterified product of a substance having a hydroxyl group and an ethylenically unsaturated group (for example, β-hydroxyethyl (meth) acrylate); an alkyl ester of acrylic acid or methacrylic acid (for example, (meth) acrylate) Methyl laurate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid 2-ethylhexyl ester); urethane (meth) acrylate (eg tolylene diisocyanate and 2-hydroxyethyl (meth) ) A reaction product with an acrylic ester, a reaction product of trimethylhexamethylene diisocyanate, cyclohexane dimethanol, and 2-hydroxyethyl (meth) acrylic ester), and the like.

  Particularly preferred (B) crosslinkable monomers are trimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate in the sense that the crosslinking density and reactivity can be easily controlled. Bisphenol A polyoxyethylene dimethacrylate. In addition, the said compound is used individually or in combination of 2 or more types.

  As will be described later, in particular, when the refractive index of the wavelength conversion type solar cell encapsulant or its lower layer (the side in contact with the solar cell) is increased, (A) a photocurable resin and / or (B) a crosslink It is advantageous that the functional monomer contains bromine and sulfur atoms. Examples of the bromine-containing monomer include New Frontier BR-31, New Frontier BR-30, New Frontier BR-42M manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and the like. Examples of the sulfur-containing monomer composition include IU-L2000, IU-L3000, and IU-MS1010 manufactured by Mitsubishi Gas Chemical Company. However, the bromine and sulfur atom-containing monomers (polymers containing them) used in the present invention are not limited to those listed here.

  (C) The photoinitiator is preferably a photoinitiator that generates free radicals by ultraviolet light or visible light. For example, benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, and benzoin phenyl ether Benzophenones such as benzophenone, N, N'-tetramethyl-4,4'-diaminobenzophenone (Michler ketone), N, N'-tetraethyl-4,4'-diaminobenzophenone, benzyldimethyl ketal (Ciba Japan) IRGACURE (Irgacure) 651), benzyl ketals such as benzyl diethyl ketal, 2,2-dimethoxy-2-phenylacetophenone, p-tert-butyldichloroacetophenone, p-dimethyl Acetophenones such as ruaminoacetophenone, xanthones such as 2,4-dimethylthioxanthone and 2,4-diisopropylthioxanthone, or hydroxycyclohexyl phenyl ketone (Ciba Japan, IRGACURE (Irgacure) 184), 1- (4- Isopropylphenyl) -2-vitroxy-2-methylpropan-1-one (Ciba Japan, Darocur 1116), 2-hydroxy-2-methyl-1-phenylpropan-1-one (Ciba Japan) Darocur 1173) etc. are mentioned, These are used individually or in combination of 2 or more types.

  Examples of (C) photoinitiators that can be used as photoinitiators include 2,4,5-triallylimidazole dimer, 2-mercaptobenzoxazole, leucocrystal violet, and tris (4-diethylamino-2). Combinations with -methylphenyl) methane and the like are also mentioned. In addition, although it does not itself have photoinitiating properties, it can be used in combination with the above-mentioned substances to provide a sensitizer system with better photoinitiating performance as a whole, such as triethanolamine for benzophenone. Secondary amines can be used.

Moreover, what is necessary is just to change the said (C) photoinitiator into a thermal initiator in order to make sealing resin thermosetting.
(C) The thermal initiator is preferably an organic peroxide that generates free radicals by heat. For example, isobutyl peroxide, α, α′bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecano Bis-n-propyl peroxydicarbonate, bis-s-butyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl neodecanoate, bis (4-t-butylcyclohexyl) peroxydi Carbonate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, di-2-ethoxyethylperoxydicarbonate, bis (ethylhexylperoxy) dicarbonate, t-hexylneodecanoate, bismethoxybutylperoxy Dicarbonate, bis (3-methyl-3 Methoxybutylperoxy) dicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, succinic peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoyl) hexane, 1-cyclohexyl -1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, 4-methylbenzoyl peroxide, t-butylperoxy-2-ethylhexanoate, m- Toluonoyl benzoyl peroxide, benzoy Ruperoxide, t-butylperoxyisobutyrate, 1,1-bis (t-butylperoxy) 2-methylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexanone 2,2-bis (4,4-dibutylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate 2,5-dimethyl-2,5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, 2,2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl -4,4-bis (t-butylperoxy) valerate, di-t-butylperoxyisophthalate, α, α'bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl -2,5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, Di-t-butylperoxy, p-menthane hydroperoxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1, 1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, t-butyl hydroperoxide, 2,3-dimethyl-2,3-diphenylbutane can be used. it can.

  The above is an example of the acrylic photocurable resin and the thermosetting resin, but the epoxy photocurable resin and the thermosetting resin that are usually used are also included in the wavelength conversion type solar cell encapsulant of the present invention. It can be used as a dispersion medium resin. However, since the curing of the epoxy is ionic, the coated phosphor or the rare earth metal complex that is a fluorescent substance may be affected and may cause deterioration or the like. Therefore, an acrylic type is more preferable.

  When a thermoplastic resin that flows by heating or pressurization is used for the dispersion medium resin of the wavelength conversion type solar cell encapsulant resin composition, for example, natural rubber, polyethylene, polypropylene, polyvinyl acetate, polyisoprene, poly- (Di) enes such as 1,2-butadiene, polyisobutene, polybutene, poly-2-heptyl-1,3-butadiene, poly-2-t-butyl-1,3-butadiene, poly-1,3-butadiene , Polyethers such as polyoxyethylene, polyoxypropylene, polyvinyl ethyl ether, polyvinyl hexyl ether, and polyvinyl butyl ether, polyesters such as polyvinyl acetate and polyvinyl propionate, polyurethane, ethyl cellulose, polyvinyl chloride, polyacrylonitrile, polymethacrylate Ronitrile, poly Lufone, phenoxy resin, polyethyl acrylate, polybutyl acrylate, poly-2-ethylhexyl acrylate, poly-t-butyl acrylate, poly-3-ethoxypropyl acrylate, polyoxycarbonyl tetramethacrylate, polymethyl acrylate, polyisopropyl methacrylate, poly Dodecyl methacrylate, polytetradecyl methacrylate, poly-n-propyl methacrylate, poly-3,3,5-trimethylcyclohexyl methacrylate, polyethyl methacrylate, poly-2-nitro-2-methylpropyl methacrylate, poly-1,1-diethyl Poly (meth) acrylic acid esters such as propyl methacrylate and polymethyl methacrylate can be used as the dispersion medium resin.

  Two or more kinds of these thermoplastic resins may be copolymerized as required, or two or more kinds may be blended and used.

  Furthermore, epoxy acrylate, urethane acrylate, polyether acrylate, polyester acrylate, or the like can be used as a copolymer resin with the above resin. In particular, urethane acrylate, epoxy acrylate, and polyether acrylate are excellent from the viewpoint of adhesiveness.

  As epoxy acrylate, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, allyl alcohol diglycidyl ether, resorcinol diglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, polyethylene glycol diglycidyl ether And (meth) acrylic acid adducts such as trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, and sorbitol tetraglycidyl ether.

  A polymer having a hydroxyl group in the molecule, such as epoxy acrylate, is effective in improving adhesion. These copolymer resins can be used in combination of two or more as required. The softening temperature of these resins is preferably 200 ° C. or less, and more preferably 150 ° C. or less from the viewpoint of handleability. Considering that the use environment temperature of the solar cell unit is usually 80 ° C. or lower and workability, the softening temperature of the resin is particularly preferably 80 to 120 ° C.

The composition of the other resin composition when the thermoplastic resin is used as the dispersion medium resin is not particularly limited as long as the above-described coated phosphor is contained, but usually used components such as a plasticizer, a flame retardant, It is possible to contain a stabilizer and the like.
As the dispersion medium resin of the wavelength conversion type solar cell encapsulant of the present invention, as described above, photocurability, thermosetting, thermoplasticity, and the resin is not particularly limited, but as a particularly preferable resin, The composition which mix | blended the thermal radical initiator with the ethylene-vinyl acetate copolymer widely utilized as the sealing material for conventional solar cells is mentioned.

  Although there is no restriction | limiting in particular about the refractive index of the said sealing resin, It is preferable that it is comparable as the refractive index of the material which coat | covers a fluorescent substance. Thereby, scattering can be more effectively suppressed. Specifically, for example, when a silica-based material is used as a material for coating a fluorescent substance, the refractive index of the silica-based material is usually 1.4 to 1.5, and therefore the sealing resin ( The refractive index of the coating resin or dispersion medium resin) is preferably the same as that.

The wavelength conversion type solar cell encapsulant of the present invention may be composed only of a wavelength convertible resin composition layer containing a coated phosphor and an encapsulating resin, but in addition to this, other than the composition layer It is preferable to further have a light transmission layer.
Examples of the light-transmitting layer other than the composition layer include a light-transmitting layer obtained by removing the coated phosphor from the wavelength-converting resin composition layer.
When the wavelength conversion type solar cell encapsulating material of the present invention is composed of a plurality of light transmissive layers, it is preferable that the wavelength conversion type solar cell encapsulating material has at least the same or higher refraction than the layer on the incident side.
Specifically, m light-transmitting layers are designated as layer 1, layer 2,..., Layer (m−1), layer m in order from the light incident side, and the refractive indexes thereof are n ₁ , _{n 2, ···, n (m} -1), when the _{n m,} it is preferable _{that n 1 ≦ n 2 ≦ ··· ≦} n (m-1) ≦ n m holds.

  Although there is no restriction | limiting in particular as a refractive index of the wavelength conversion type solar cell sealing material of this invention, Preferably it is 1.5-2.1, More preferably, it is 1.5-1.9. Moreover, when the wavelength conversion type solar cell sealing material of this invention consists of a some light transmissive layer, it is preferable that the whole refractive index of the wavelength conversion type solar cell sealing material is in the said range.

  It is preferable that the wavelength conversion type solar cell sealing material of this invention is arrange | positioned on the light-receiving surface of a photovoltaic cell. By doing so, it is possible to follow the uneven structure including the texture structure of the solar cell light receiving surface, the cell electrode, the tab line and the like without a gap.

<Method for Producing Wavelength Conversion Type Solar Cell Sealant>
The wavelength conversion type solar cell encapsulant of the present invention includes, for example, (1) a phosphor material coated with a silica material by a sol-gel reaction using silicon alkoxide to form a silica material layer on the surface of the phosphor material. A fluorescent substance coating step in which the silica-based material layer is further coated with a moisture-resistant material (preferably a vinyl resin) to obtain a coated phosphor; and (2) the coated phosphor is a dispersion medium resin (transparent sealing resin). The resin composition obtained by mixing or dispersing in a sheet can be produced by a production method including a sheet forming step of forming a sheet.

  The wavelength conversion type solar cell encapsulant of the present invention includes, for example, (1) a fluorescent material coating step of obtaining a coated phosphor by coating a fluorescent material with a silica-based material by a sol-gel reaction using silicon alkoxide; 2) A sheet forming step of forming a resin composition obtained by mixing or dispersing the coated phosphor in a non-hydrolyzable resin (transparent sealing resin) into a sheet form can be produced by a production method.

The details of the fluorescent material coating step are as described above. Moreover, the sheet | seat formation process can use the method normally used as a method of forming a resin composition in a sheet form without a restriction | limiting in particular.
The wavelength conversion type solar cell encapsulant of the present invention is preferably formed in a sheet shape from the viewpoint of ease of use.

<Solar cell module>
The present invention also includes a solar module including the wavelength conversion type solar cell encapsulant. The solar cell module of this invention is equipped with the photovoltaic cell and the said wavelength conversion type solar cell sealing material arrange | positioned on the light-receiving surface of the said photovoltaic cell. This improves power generation efficiency.
The wavelength conversion type solar cell encapsulant of the present invention is used as one of light transmissive layers of a solar cell module having a plurality of light transmissive layers and solar cells, for example.

  In this invention, a solar cell module is comprised from required members, such as an antireflection film, protective glass, a wavelength conversion type solar cell sealing material, a photovoltaic cell, a back film, a cell electrode, a tab wire, for example. Among these members, the light-transmitting layer having light transmittance includes an antireflection film, a protective glass, the wavelength conversion type solar cell sealing material of the present invention, a SiNx: H layer and a Si layer of the solar cell, and the like. Can be mentioned.

  In the present invention, the order of lamination of the light-transmitting layers mentioned above is usually an antireflection film, protective glass, and the wavelength conversion type solar cell sealing of the present invention, which are formed in order from the light receiving surface of the solar cell module. The material is a SiNx: H layer or Si layer of the solar battery cell.

  That is, in the wavelength conversion type solar cell encapsulant of the present invention, the external light entering from any angle has little reflection loss, and the refractive index of the wavelength conversion type solar cell encapsulant is efficiently introduced into the solar cell. The light-transmitting layer disposed on the light incident side from the wavelength conversion type solar cell encapsulant, that is, higher than the refractive index of the antireflection film, protective glass, etc., and the reflection of the wavelength conversion type solar cell encapsulant The refractive index of the light transmissive layer disposed on the incident side, that is, the SiNx: H layer (also referred to as “cell antireflection film”) and the Si layer of the solar battery cell is preferably lower.

  Specifically, the light transmitting layer disposed on the light incident side from the wavelength conversion type solar cell encapsulant, that is, the refractive index of the antireflection film is 1.25 to 1.45, and the refractive index of the protective glass is Usually, about 1.45 to 1.55 is used. The refractive index of the light transmissive layer disposed on the light incident side of the wavelength conversion type solar cell encapsulant, that is, the SiNx: H layer (cell antireflection film) of the solar cell is usually 1.9 to 2. The refractive index of about 1 and the Si layer or the like is usually about 3.3 to 3.4. From the above, the refractive index of the wavelength conversion type solar cell encapsulant of the present invention is preferably 1.5 to 2.1, more preferably 1.5 to 1.9.

In addition, the preferable refractive index of the other layer of a light transmissive layer is as showing below. For example, a layer of three layers from the light incident side of the light transmitting layer, b layer, when the c layer, or the refractive index n _a of each _layer, n _b, n _c satisfies the following formula, approximated It is preferable.
n _b = √ (n _a · n _c ) (formula)

  By using a europium complex as the fluorescent material used for the wavelength conversion type solar cell sealing material of the present invention, a solar cell module having high power generation efficiency can be realized. The europium complex converts light in the ultraviolet region into light in the red wavelength region with high wavelength conversion efficiency, and the converted light contributes to power generation in the solar battery cell.

<Method for manufacturing solar cell module>
Using the sheet-shaped resin composition that becomes the wavelength conversion type solar cell encapsulant of the present invention, the wavelength conversion type solar cell encapsulant is formed on the solar cell to produce a solar cell module.
Specifically, it is the same as the manufacturing method of a normal silicon crystal solar cell module, and instead of the normal sealing material sheet, the wavelength conversion type solar cell sealing material (particularly preferably in the form of a sheet) of the present invention is used. .

  Generally, a silicon crystal solar cell module is first made into a sheet-like sealing material (mostly an ethylene-vinyl acetate copolymer with a thermal radical initiator on a cover glass which is a light receiving surface, and a thermosetting type. ). In this invention, the wavelength conversion type solar cell sealing material of this invention is used for the sealing material used here. Next, the cells connected by tab wires are placed, and a sheet-shaped sealing material (in the present invention, a wavelength conversion type solar cell sealing material may be used only on the light receiving surface side. And a back sheet, and a module using a vacuum press laminator dedicated to the solar cell module.

  At this time, the hot plate temperature of the laminator is a temperature necessary for the sealing material to soften and melt, wrap the cell, and further harden, and is usually 120 to 180 ° C., most of which is 140 to 160 ° C. Designed to cause these physical and chemical changes.

The wavelength conversion type solar cell encapsulant of the present invention is in a state before being made into a solar module, specifically, in a semi-cured state when a curable resin is used. In addition, the refractive index of the wavelength conversion type solar cell sealing material in a semi-cured state and the wavelength conversion type solar cell sealing material after being cured (after being formed into a solar module) is not greatly changed.
Although there is no restriction | limiting in particular in the form of the wavelength conversion type solar cell sealing material of this invention, It is preferable that it is a sheet form from the ease of manufacture of a solar module.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “%” is based on mass.

(Example 1)
<Synthesis of fluorescent substances>
200 mg of 4,4,4-trifluoro-1- (thienyl) -1,3-butanedione (TTA) was dissolved in 7 ml of ethanol, and 1.1 ml of 1M sodium hydroxide was added thereto and mixed. 6.2 mg of 1,10-phenanthroline dissolved in 7 ml of ethanol is added to the above mixed solution and stirred for 1 hour, and then a solution of 103 ml of EuCl ₃ · 6H ₂ O in 3.5 ml is added to obtain a precipitate. This was filtered off, washed with ethanol, and dried to obtain a fluorescent substance Eu (TTA) ₃ Phen.

<Preparation of sol-gel glass-coated phosphor>
Using the Eu (TTA) ₃ Phen obtained above, a sol-gel solution was prepared with the materials and blending amounts shown in Table 1.
In the molar ratio shown in Table 1, the materials (a) to (d) in the table were mixed, and the other materials (e) to (f) were mixed. After mixing and stirring each well, both were mixed and stirred for 2 hours to obtain a coated phosphor solution. This solution was taken out into a Teflon (registered trademark) vat and the volatile components were removed in an oven at 120 ° C. for 5 hours to obtain a sol-gel glass-coated phosphor powder.

<Preparation of resin-coated sol-gel glass-coated phosphor>
0.5 g of the sol-gel glass-coated phosphor powder obtained above, 100 g of ethyl acrylate, and 0.1 g of lauroyl peroxide as a thermal radical initiator were weighed out and stirred in a flask for 60 g. Heated to ° C. After stirring for 3 hours, a highly viscous liquid was obtained. This was used as a coated phosphor.

<Preparation of resin composition for wavelength conversion type solar cell encapsulant>
100 g of Ultrasen 634, an ethylene-vinyl acetate resin (EVA) manufactured by Tosoh Corporation as a sealing resin (dispersion medium resin), and Luperox 101, a peroxide thermal radical initiator manufactured by Arkema Yoshitomi Corporation Using a roll mixer adjusted to 100 ° C., 1.5 g of SZ6030, a silane coupling agent made by Toray Dow Corning Co., Ltd., and 0.0104 g of the coated phosphor were adjusted to 100 ° C. And the resin composition for wavelength conversion type solar cell sealing materials was obtained.

<Preparation of wavelength conversion type solar cell encapsulant sheet>
About 30 g of the resin composition for wavelength conversion type solar cell encapsulant obtained above is sandwiched between release sheets, a 0.6 mm thick stainless steel spacer is used, and a hot plate is adjusted to 80 ° C. I made it.

<Preparation of solar cell encapsulant sheet for back surface>
In the production of the wavelength conversion type solar cell encapsulant sheet, instead of the wavelength conversion type solar cell encapsulant resin composition, a resin composition prepared in the same manner as above except that it does not contain a coated phosphor. The solar cell encapsulant sheet for back surface was produced by the same method as above.

<Production of wavelength conversion type solar cell module>
The wavelength conversion type solar cell sealing material sheet is placed on a tempered glass (manufactured by Asahi Glass Co., Ltd.) as a protective glass, and a photovoltaic cell on which the electromotive force can be taken out is provided on the light receiving surface. Put it on the bottom, and further put a solar cell encapsulant sheet for the back side and a PET film (product name: A-4300, manufactured by Toyobo Co., Ltd.) as a back film, laminate it using a vacuum laminator, A conversion type solar cell module was produced.

<Evaluation of solar cell characteristics>
As a simulated solar ray, using a solar simulator (Wacom Denso Co., Ltd., WXS-155S-10, AM1.5G), current voltage characteristics using an IV curve tracer (Eihiro Seiki Co., Ltd., MP-160), In accordance with JIS-C8914, the short-circuit current density Jsc in the cell state before module sealing and the short-circuit current density Jsc after module sealing were measured and evaluated by taking the difference (ΔJsc). As a result, ΔJsc was 0.11 mA / cm ² . The measurement results are shown in Table 2 and FIG.
FIG. 1 shows the relationship between the amount of coated phosphor contained in the wavelength-convertible resin composition layer and the power generation efficiency.

<Evaluation of luminous high temperature and humidity resistance>
Using a blue glass of 5 cm × 10 cm × 1 mm as protective glass in the same manner as in the above <Preparation of wavelength conversion type solar cell module>, the wavelength conversion type solar cell sealing material sheet is placed thereon, and a back film A PET film (manufactured by Toyobo Co., Ltd., trade name: A-4300) was placed thereon, laminated using a vacuum laminator, and this was used as a test piece.
The test piece was irradiated with 365 nm light using a handy UV lamp SLUV-4 manufactured by AS ONE Co., Ltd., and the presence or absence of red light emission was observed. Further, this test piece was placed in a constant temperature and humidity chamber adjusted to 85 ° C. and 85% relative humidity, and the presence or absence of red light emission was observed in the same manner as described above at an appropriate time. As a result, light emission was confirmed up to 500 hours. The observation results are shown in Table 2.

(Example 2)
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 0.0166 g instead of 0.0104 g. In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.33 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

(Example 3)
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 0.0342 g instead of 0.0104 g. In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.16 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

Example 4
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 0.0539 g instead of 0.0104 g In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.28 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

(Example 5)
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 0.1037 g instead of 0.0104 g In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.38 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

(Example 6)
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 0.1534 g instead of 0.0104 g In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.33 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

(Example 7)
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 0.1555 g instead of 0.0104 g In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.75 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

(Example 8)
In <Preparation of Resin Composition for Wavelength Conversion Type Solar Cell Encapsulant> in Example 1 above and adjustment except that the content of the coated phosphor is changed to 0.2592 g instead of 0.0104 g The coated phosphor was evaluated in terms of ΔJsc and emission high temperature and high humidity resistance by the same procedure and method, with 0.01 g being g. As a result, ΔJsc was 0.22 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

Example 9
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 0.5184 g instead of 0.0104 g. In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.26 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

(Example 10)
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 1.0368 g instead of 0.0104 g. In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.14 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

(Example 11)
In <Preparation of wavelength conversion solar cell encapsulant resin composition> in Example 1, the same procedure as above except that the content of the coated phosphor was changed to 1.5552 g instead of 0.0104 g In this method, ΔJsc and light emitting high temperature and high humidity resistance were evaluated. As a result, ΔJsc was 0.12 mA / cm ² , and luminescence was confirmed up to 500 hours. Table 2 shows the measurement results and the observation results.

(Example 12)
1.555 g of the sol-gel glass-coated phosphor prepared in Example 1 and 100 g of NUC-6510 (ethylene-ethyl acrylate, EEA) manufactured by Nihon Unicar Co., Ltd. as a non-hydrolyzable sealing resin are adjusted to 100 ° C. Using the roll mixer, the resin composition for wavelength conversion type solar cell encapsulant was obtained. Thereafter, the light emitting high temperature and high humidity resistance was evaluated by the same procedure and method. As a result, light emission was confirmed up to 500 hours. The observation results are shown in Table 2.

(Comparative Example 1)
In Example 1, instead of using the resin composition for wavelength conversion type solar cell encapsulant containing the coated phosphor, a resin composition for solar cell encapsulant for the back surface not containing the coated phosphor was used, A solar cell module was produced in the same manner as in Example 1.
ΔJsc was evaluated in the same manner as described above except that the obtained solar cell module was used. As a result, ΔJsc was 0.00 mA / cm ² . The measurement results are shown in Table 2.

  From the above, it can be seen that by using the wavelength conversion type solar cell sealing material of the present invention, the light utilization efficiency in the solar cell module can be improved and the power generation efficiency can be stably improved.

  The wavelength conversion type solar cell encapsulant of the present invention can reduce sunlight loss due to spectrum mismatch and have a higher visible light transmittance, thereby improving light utilization efficiency and improving power generation efficiency. it can.

Claims (13)

A coated phosphor including a phosphor and a coating layer having a lower refractive index than that of the phosphor covering the phosphor; and
Sealing resin;
A wavelength conversion type solar cell sealing material provided with the light-transmitting resin composition layer containing.   The wavelength conversion type solar cell sealing material according to claim 1, wherein a content of the coated phosphor in the resin composition layer is 0.0001 to 10 mass percent.   The wavelength conversion type solar cell encapsulant according to claim 1 or 2, wherein the coating layer contains a silica-based compound formed by a sol-gel method.   The wavelength conversion type solar cell sealing material according to any one of claims 1 to 3, wherein the sealing resin is a non-hydrolyzable resin.   The wavelength-converting solar cell sealing material according to any one of claims 1 to 4, wherein the coated phosphor further has a protective layer containing a moisture-resistant material on an outer surface of the coating layer.   The wavelength conversion type solar cell sealing material according to any one of claims 1 to 5, further comprising a light-transmitting layer other than the resin composition layer. M layers composed of the resin composition layer and a light transmissive layer other than the resin composition layer are provided, and the refractive indexes of the m layers are set to n ₁ and n _{2 in} order from the light incident side. _{, ···, n (m-1} ), when the _{n m, n 1 ≦ n 2} ≦ ··· ≦ n (m-1) is ≦ _{n m,} the wavelength conversion type according to claim 7 Solar cell encapsulant.   The wavelength conversion type solar cell sealing material according to any one of claims 1 to 7, wherein the fluorescent material is a europium complex.   The wavelength conversion type solar cell sealing material according to any one of claims 5 to 8, wherein the moisture-resistant material is a vinyl resin.   A solar cell module provided with a photovoltaic cell and the wavelength conversion type solar cell sealing material of any one of Claims 1-9 arrange | positioned on the light-receiving surface of the said photovoltaic cell. A fluorescent material is coated with a silica-based material by a sol-gel reaction using silicon alkoxide to form a silica-based material layer on the surface of the fluorescent material, and the silica-based material layer is further coated with a vinyl resin to form a coated phosphor. Obtaining a phosphor coating step;
A sheet forming step of forming a resin composition obtained by mixing or dispersing the coated phosphor in a sealing resin into a sheet; and
The manufacturing method of the wavelength conversion type solar cell sealing material which has this. A fluorescent substance coating step in which a fluorescent substance is coated with a silica-based material by a sol-gel reaction using silicon alkoxide to obtain a coated phosphor;
A sheet forming step of forming a resin composition obtained by mixing or dispersing the coated phosphor in a non-hydrolyzable resin into a sheet; and
The manufacturing method of the wavelength conversion type solar cell sealing material which has this. A method for producing a solar cell module having a plurality of light transmissive layers and solar cells,
A step of disposing the wavelength conversion type solar cell encapsulant according to any one of claims 1 to 9 on a light receiving surface side of a solar cell to form one of the light transmissive layers. The manufacturing method of the solar cell module which has.