JP2013046986A - Method of manufacturing wavelength conversion solar cell sealing material and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an inexpensive wavelength conversion solar cell sealing material while maintaining or improving power generation efficiency, when it is applied to a solar cell module.SOLUTION: In this method of manufacturing a wavelength conversion solar cell sealing material 30 includes a formation step of two dimensionally scattering and adhering spherical phosphor bodies 40 containing a phosphor material on a surface out of sheet-like sealing material surfaces that is in contact with a solar battery cell 10 during the manufacture of a solar cell module.

Description

  The present invention relates to a method for producing a wavelength conversion type solar cell encapsulant. More specifically, it is used in a solar cell module that can increase power generation efficiency by converting light in a wavelength region that does not contribute to power generation into a wavelength region light that contributes to power generation using a fluorescent material (also referred to as a light emitting material). The present invention relates to a method for manufacturing a wavelength conversion type solar cell encapsulant and a solar cell module.

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

  Moreover, the uneven | corrugated pattern is formed inside, and the surface of a solar cell module is smooth. In addition, in order to improve the introduction efficiency of sunlight, uneven | corrugated shape may be given also outside. Moreover, the sealing material and back film for protecting and sealing a photovoltaic cell and a tab wire are provided under the protective glass.

Using a fluorescent material, by converting the wavelength of light in the ultraviolet region or infrared region that contributes little to power generation in the sunlight spectrum, a layer that emits light in the wavelength region that contributes greatly to power generation is placed on the solar cell light receiving surface side. For example, JP 2000-328053 A (Patent Document 1) has been proposed as a number of methods.
Japanese Patent Laying-Open No. 2006-303033 (Patent Document 2) proposes a method of incorporating a rare earth complex that is a fluorescent substance into a sealing material as a wavelength conversion material.

JP 2000-328053 A JP 2006-303033 A

  According to the method described in the above Japanese Patent Application Laid-Open No. 2006-303033 (Patent Document 2), the wavelength conversion of light in a wavelength region that contributes little to power generation into light in a wavelength region that contributes greatly to power generation is performed. Contains substances. As this fluorescent substance, an organic fluorescent substance, an organometallic complex, an inorganic fluorescent substance or the like is used, which is expensive. Moreover, when using a wavelength conversion layer as a sealing material, the film thickness of about 600 micrometers is required from a viewpoint of cell protection.

  However, if a sealing material containing a fluorescent material having a sufficient wavelength conversion effect is produced with a thickness of 600 μm, the content of the fluorescent material is increased and the cost is increased. Is not necessarily appropriate.

  Accordingly, an object of the present invention is to provide an inexpensive method for manufacturing a wavelength conversion type solar cell encapsulant while maintaining or improving power generation efficiency when applied to a solar cell module. Moreover, it is providing the solar cell module using the wavelength conversion type solar cell sealing material obtained by the manufacturing method of the wavelength conversion type solar cell sealing material.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that when the spherical phosphor is uniformly dispersed two-dimensionally on the surface of the sheet-like sealing material, and uniformly within the sealing material, 3 In the case of dimensional dispersion, when comparing the ratio of power generated to incident sunlight (power generation efficiency), even if it is dispersed only on the surface, it is equivalent to or more than if it is dispersed throughout The result of showing the power generation efficiency was obtained. In view of this result, the sealing material on the light receiving side of the solar cell module is formed by attaching a spherical phosphor to the surface in contact with the solar cell at the time of solar cell module production, while maintaining or improving the power generation efficiency, We found that cost reduction can be realized. Here, as described in Japanese Patent Application No. 2010-090351, the spherical phosphor is prepared by, for example, dissolving a fluorescent material such as an organometallic complex in an acrylic monomer, and forming this into a spherical resin encapsulant by suspension polymerization. It's about things.
That is, the present invention is as follows.

<1> Among the sheet-shaped encapsulant surfaces, the step of forming a spherical phosphor containing a fluorescent substance two-dimensionally dispersed and attached to the surface that comes into contact with the solar battery cell when the solar battery module is produced. The manufacturing method of the wavelength conversion type solar cell sealing material.
<2> In the step of two-dimensionally spraying and adhering the spherical phosphor, the sheet-like resin is softened using a heating / pressurizing roll, the spherical phosphor is sprayed thereon, and then heated and heated again. The method for producing a wavelength conversion type solar cell sealing material according to <1>, wherein the spherical phosphor is fixed to a sheet using a pressure roll.
<3> In the step of forming the spherical phosphor by two-dimensionally spreading and adhering, the spherical phosphor is supplied onto a heating / pressurizing roll having a concave shape on the surface to soften the sheet-like resin. At the same time, the method for producing a wavelength conversion type solar cell encapsulating material according to <1>, wherein the spherical phosphor is dispersed and fixed thereon.
<4> In the step of forming the spherical phosphor by two-dimensionally spreading and adhering it, using a heating / pressurizing roll having a convex shape on the surface, the sheet-like resin is softened to form a dent, and a spherical shape is formed thereon. The method for producing a wavelength-converting solar cell encapsulant according to <1>, wherein the phosphor is dispersed and fixed by reheating.
<5> In the process of forming and attaching the spherical phosphor in a two-dimensional manner, a plate is placed on the sheet-like resin, and the spherical phosphor is sprayed on the plate by squeegeeing and fixed by heating. The manufacturing method of the wavelength conversion type solar cell sealing material as described in said <1> formed.
<6> In the step of forming the spherical phosphor by two-dimensionally spreading and adhering, the spherical phosphor is placed on a mold having a recess capable of holding the spherical phosphor, and this is placed under the sheet-like resin. The method for producing a wavelength-converting solar cell encapsulating material according to <1>, wherein the method is formed by pressing from above and fixing by pressing and heating with a pressure plate from the upper side of the opposite sheet-shaped resin.
<7> The method for producing a wavelength conversion solar cell sealing material according to any one of <1> to <6>, wherein the fluorescent substance contained in the spherical phosphor is a europium complex.
<8> The wavelength-converting solar cell sealing material according to any one of <1> to <6>, wherein the fluorescent substance contained in the spherical phosphor is encapsulated in resin particles containing a vinyl compound as a monomer compound. Manufacturing method.
<9> Solar cell and wavelength conversion obtained by the method for producing a wavelength conversion type solar cell encapsulating material according to any one of <1> to <8>, provided on the light receiving surface side of the solar cell. A solar cell module.

  ADVANTAGE OF THE INVENTION According to this invention, when it applies to a solar cell module, the manufacturing method of an inexpensive wavelength conversion type solar cell sealing material can be provided, maintaining or improving electric power generation efficiency. Moreover, the solar cell module using the wavelength conversion type solar cell sealing material obtained by the manufacturing method of the wavelength conversion type solar cell sealing material of this invention can be provided.

It is a schematic sectional drawing which shows the solar cell module of this invention. It is a schematic sectional drawing which shows the manufacturing process of a solar cell module. In the manufacturing method of the wavelength conversion type solar cell sealing material of this invention, it is a schematic sectional drawing which shows an example of the method which can provide the structure where spherical fluorescent substance adjoins to a photovoltaic cell. In the manufacturing method of the wavelength conversion type solar cell sealing material of this invention, it is a schematic sectional drawing which shows an example of the method which can provide the structure where spherical fluorescent substance adjoins to a photovoltaic cell. In the manufacturing method of the wavelength conversion type solar cell sealing material of this invention, it is a schematic sectional drawing which shows an example of the method which can provide the structure where spherical fluorescent substance adjoins to a photovoltaic cell. In the manufacturing method of the wavelength conversion type solar cell sealing material of this invention, it is a schematic sectional drawing which shows an example of the method which can provide the structure where spherical fluorescent substance adjoins to a photovoltaic cell. In the manufacturing method of the wavelength conversion type solar cell sealing material of this invention, it is a schematic sectional drawing which shows an example of the method which can provide the structure where spherical fluorescent substance adjoins to a photovoltaic cell. In the manufacturing method of the wavelength conversion type solar cell sealing material of this invention, it is a schematic sectional drawing which shows an example of the method which can provide the structure where spherical fluorescent substance adjoins to a photovoltaic cell.

  The solar cell module of the present invention includes at least a solar cell and a wavelength conversion type solar cell encapsulating material provided as one of light transmissive layers on the light receiving surface side of the solar cell. In the present invention, the wavelength-converting solar cell encapsulant is formed by two-dimensionally dispersing and adhering a spherical phosphor on the surface of the encapsulant surface that is in contact with the solar cells when the solar cell module is manufactured. Become. The wavelength conversion type solar cell encapsulant may be composed of one layer or two or more layers, but is composed of one layer from the viewpoint of cost and simplification of the manufacturing process. It is good.

In the method for producing a wavelength conversion type solar cell encapsulant of the present invention, a sheet-like wavelength conversion type solar cell encapsulant is used as a base material, and a spherical phosphor is dispersed and adhered to the surface in contact with the solar cells. Is done. By using this wavelength conversion type solar cell encapsulant as one of the light transmissive layers of the solar cell module, a spherical phosphor so that it can contact the vicinity of the light receiving surface side of the solar cell or the surface of the solar cell. Can be provided uniformly two-dimensionally in the plane direction, and the light is efficiently emitted without attenuation of the excitation light. This light emission is caused by the spherical phosphor being in contact with the solar battery cell. It can be introduced efficiently and power generation efficiency can be improved.
The wavelength conversion type solar cell encapsulant is formed by two-dimensionally dispersing and adhering the spherical phosphor on the surface that comes into contact with the solar cell when the solar cell module is manufactured, thereby reducing the content of the spherical phosphor. The manufacturing cost is lower than that of the conventional one. Moreover, when the wavelength conversion type solar cell encapsulant having such a structure is used, the power generation efficiency is maintained or improved despite the reduction of the content of the spherical phosphor. The reason for this is not clear, but is presumed as follows.

  When light enters the solar cell module, the spherical phosphor (fluorescent substance) contained in the sealing material provided on the light receiving surface side absorbs light having an excitation wavelength. At this time, if the spherical phosphors are uniformly dispersed in the film thickness direction of the encapsulant, the light absorption in the film thickness direction is attenuated as it becomes deeper in the film thickness direction of the encapsulant. Therefore, it is considered that the spherical phosphor existing in a deep portion in the film thickness direction of the encapsulant has a weak excitation wavelength, so that sufficient light emission cannot be obtained and the contribution to wavelength conversion is reduced. On the other hand, when the spherical phosphor is uniformly dispersed two-dimensionally so as to be in contact with the vicinity of the solar cell or the surface of the solar cell, the excitation light is not attenuated even when it becomes deep in the film thickness direction, It is considered that excitation light easily reaches the spherical phosphor in the vicinity of the solar battery cell or the surface of the solar battery cell, and light emission is efficiently introduced into the solar battery cell.

  Furthermore, the reduction of the content of the spherical phosphor suppresses light scattering by the spherical phosphor and increases the visible light transmittance. Accordingly, the amount of light reaching the solar battery cell is increased, the light use efficiency of the solar battery module is increased, and the power generation efficiency can be improved. Moreover, it is considered that the light whose wavelength has been efficiently converted is introduced into the solar battery cell by positioning the spherical phosphor so as to be in the vicinity of the solar battery cell or in contact with the surface of the solar battery cell.

  The total thickness of the wavelength conversion type solar cell encapsulant is preferably 10 μm to 1000 μm from the viewpoint of the sealing effect, and more preferably 200 μm to 800 μm. These thicknesses are not different from the concept optimized in terms of cell protection and reliability in a conventional sealing material having no wavelength conversion function.

It is desirable that the concentration of the spherical phosphor dispersed and adhered on the surface of the sheet-shaped sealing material is appropriately adjusted depending on the type of the spherical phosphor. In general, the content of the spherical phosphor is preferably 0.001 to 10 parts by mass, and more preferably 0.002 to 5 parts by mass with respect to 100 parts by mass of the sealing material resin on the light receiving surface side. . By setting it as 0.001 mass part or more, wavelength conversion efficiency will become more sufficient, and the fall of the light quantity which reaches | attains a photovoltaic cell can be suppressed more by setting it as 10 mass parts or less. Moreover, as content of the spherical fluorescent substance mass reference | standard regarding a module area, it is preferable that it is 0.001-10g per 1 m < ² > module, and it is more preferable that it is 0.002-5g. By setting it as 0.001 g or more per 1 m < ² > module, wavelength conversion efficiency becomes more sufficient, and the fall of the light quantity which reaches | attains a photovoltaic cell can be suppressed more by setting it as 10 g or less. Furthermore, the content based on the number of spherical phosphors related to the module area is preferably 2,000 to 2,000,000, and 4,000 to 1,000,000 per 1 m ² of the module. More preferred. The wavelength conversion efficiency becomes more sufficient by setting the number to 2,000 or more per 1 m ^{2 of the} module, and the decrease in the amount of light reaching the solar cell is further suppressed by setting the number to 2,000,000 or less. be able to.

  Furthermore, the solar cell module of this invention is demonstrated, referring drawings.

FIG. 1 is a schematic cross-sectional view of the solar cell module of the present invention.
In the solar cell module of FIG. 1, a protective glass (also referred to as a cover glass) 20 is provided on the surface of the solar cell 10 on the light receiving surface side. The protective glass 20 is not particularly limited, but tempered glass is preferably used in consideration of impact resistance. In addition, in order to improve adhesiveness with a sealing material (it is also mentioned a filler), it is preferable that the surface by the side of the sealing material of the protective glass 20 is given the uneven | corrugated pattern by embossing. The light-receiving side surface of the protective glass 20 may be smooth, or may have an uneven shape in order to increase the efficiency of introducing sunlight.

  Between the protective glass 20 and the solar battery cell 10, the wavelength conversion type solar battery sealing material 30 is provided. The wavelength conversion type solar cell encapsulant 30 in FIG. 1 is uniform on the solar cell 10 side so that the spherical phosphor 40 is two-dimensionally in contact with the vicinity of the solar cell or the surface of the solar cell in the surface direction. Is installed. However, regarding the manufacturing method of the wavelength conversion type solar cell encapsulant 30, here, it is two-dimensionally dispersed and adhered to the solar cell side surface, as shown in FIGS. 2 (a) and 2 (b). The encapsulant is formed such that a spherical phosphor protrudes on the surface. In the manufacturing process of the solar cell module, the wavelength conversion type solar cell encapsulant 30 is once melted and cured, so that the spherical phosphor 40 penetrates into the wavelength conversion type solar cell encapsulant 30 in the form of a module. become. In such a meaning, in the sheet-form wavelength conversion type solar cell sealing material 30 as shown in FIG. 2 (c), the spherical phosphor 40 may be embedded in the solar cell cell, Alternatively, in order to be formed so as to be in contact with the surface of the solar battery cell, it is desirable to project at least some part from the sheet-form wavelength conversion solar battery sealing material 30. Details of the material constituting the wavelength conversion type solar cell encapsulant 30 will be described later.

  In the solar battery module, a back film 50 is provided on the back side of the solar battery cell 10. Between the back film 50 and the solar battery cell 10, a back surface sealing material 35 for protecting and sealing the solar battery cell from an impact from the back surface of the module or the like is provided. The back surface sealing material 35 is not particularly limited as long as it can protect and seal solar cells, but it is desirable that the back surface sealing material 35 has the same composition as the wavelength conversion solar cell sealing material 30. However, in this case, a spherical phosphor is unnecessary.

Although not shown in FIG. 1, the solar cell module of the present invention may further include a member that is normally provided in the solar cell module, such as an antireflection film.
A phosphor necessary for the present invention, a spherical phosphor that is a spherical transparent resin containing the phosphor, and a wavelength conversion type solar cell encapsulant further containing this spherical phosphor are described in detail below. The method by which the spherical phosphor, which is the main part, can provide a structure close to the solar battery cell is shown in FIGS.
The sealing material according to the present invention as well as the conventional sealing material is a kneaded resin composition mainly composed of ethylene-vinyl acetate copolymer (EVA) and processed into a sheet (sheet-shaped resin). It is. As described below, kneading and sheeting are not particularly limited, and conventional methods can be used. In particular, regarding sheet formation, extrusion molding and calendar molding are generally used, and these methods can also be used in the present invention. In addition, the arrow in FIGS. 3-8 has shown the advancing direction of the sealing material formed into the sheet.

  In the method shown in FIG. 3, the sheeted sealing resin (sheet-shaped resin) 31 is softened by passing the heating / pressure roll 60 through the sheeted sealing resin (sheet-shaped resin) 31. A predetermined amount of the spherical phosphor 40 is dispersed using the spherical phosphor quantitative supply device 70. In this state, since the spherical phosphor 40 may be peeled off from the sheet, the spherical phosphor 40 is further pushed into the sheet by using the heating / pressurizing roll 60 and is fixed by cooling. However, the first heating / pressurizing roll 60 can be omitted in consideration of the previous process.

  In the method shown in FIG. 4, a predetermined amount of spherical phosphor 40 is supplied to a roll (gravure roll 61) having a dent on which the spherical phosphor is temporarily fixed using a spherical phosphor quantitative supply device 70, and the sheet is softened. By pressing the gravure roll 61 against the formed sealing resin (sheet-like resin) 31, the spherical phosphor 40 is attached and fixed on the sheet surface. Here, if necessary, the spherical phosphor and the roll recess may be charged in pairs and temporarily fixed. In this case, the arrangement of the spherical phosphor can be accurately determined by the design of the gravure roll.

  In the method shown in FIG. 5, a roll 62 having a convex shape is used, and a recess is provided in advance so that the spherical phosphor 40 can be easily placed on the sheet-like resin 31. A predetermined amount of the spherical phosphor 40 is supplied therewith using the spherical phosphor quantitative supply device 70, and the excess spherical phosphor 40 is removed by the squeegee device 72. Further, the spherical phosphor 40 is fixed on the sheet-like resin 31 by softening and cooling the sheet-like resin 31 with the heating device 71. In this case, the arrangement of the spherical phosphors can be accurately determined by the design of the convex roll.

  In the method shown in FIG. 6, a plate (mask mesh) 80 is placed on a sealing resin (sheet-like resin) 31 formed into a sheet, and a predetermined amount of the spherical phosphor 40 is supplied using the spherical phosphor quantitative supply device 70. Then, the excess spherical phosphor 40 is removed by the mask squeegee device 81. Next, the plate (mask mesh) 80 is removed, and the spherical phosphor 40 disposed on the sheet softens the sheet by the heating device 71 and cools, thereby fixing the spherical phosphor on the sheet. In this case, the arrangement of the spherical phosphors can be accurately determined by the design of the plate (mask mesh).

In the method shown in FIG. 7, the sheet 82 is formed by pressing a mold 82 in which a spherical phosphor is previously placed on the lower side of the sealing resin (sheet-like resin) 31 and pressing a pressure plate 83 from the upper side. A spherical phosphor 40 is attached to the surface. Further, the spherical phosphor 40 is fixed on the sheet by softening and cooling the sheet by the heating device 71. However, the heating device can be omitted by heating the spherical phosphor arrangement mold 82 and / or the pressure plate 83. In this case, the arrangement of the spherical phosphor can be accurately determined by the design of the spherical phosphor arrangement mold.
As shown in FIG. 8, the method of disposing the spherical phosphor on the mold is to supply the spherical phosphor 40 onto a mold 82 having a recess where the spherical phosphor 40 can be disposed. It is obtained by removing the phosphor 40 by the squeegee device 72.

<Wavelength conversion solar cell encapsulant>
Below, the substance used for the manufacturing method of the wavelength conversion type solar cell sealing material of this invention is demonstrated in detail.

(Fluorescent substance)
The fluorescent substance in the spherical phosphor 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 -Naphtoyl Trifluoroacetone, 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-hexanedi 1-phenyl-3- (2-thienyl) -1,3-propanedione, 3- (t-butylhydroxymethylene) -d-camphor, 1,1,1-trifluoro-2,4-pentanedione 1,1,1,2,2,3,3,7,8,8,9,9,9-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-hexane Dione, 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 4,4-trifluoro-1- (thienyl) -1,3-butanedione (TTA), 1- (pt-butylphenyl) -3- (N-methyl-3-pyrrole) -1,3-propane Dione (BMPP), 1- (pt-butylphenyl) -3- (p-methoxyphenyl) -1,3-propanedione (BMDBM), 1,3-diphenyl-1,3-propanedione, Ben Zoylacetone, dibenzoylacetone, diisobutyroylmethane, dibiparoylmethane, 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- Examples include heptafluoropropyl-3-tert-butyl-1,3-propanedione, 1,3-diphenyl-2-methyl-1,3-propanedione, 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.

Among them, for example, Eu (TTA) ₃ phen, Eu (BMPP) ₃ phen, Eu (BMDBM) ₃ phen, and the like can be preferably used as the rare earth complex having the above-described ligand 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 methods 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.

More preferably, the fluorescent substance is encapsulated in resin particles (referred to as a spherical phosphor). 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 fluorescent substance and a vinyl compound is prepared, and the vinyl compound is suspended or emulsion-polymerized using a radical polymerization initiator, whereby spherical resin particles (spherical fluorescence containing the fluorescent substance are contained). Body). In the present invention, the spherical phosphor refers to a product obtained by polymerizing a vinyl compound containing a fluorescent substance.

The average particle diameter of the spherical phosphor is preferably 0.1 μm to 600 μm, more preferably 1 μm to 300 μm, and further preferably 10 μm to 250 μm from the viewpoint of improving light utilization efficiency.
The average particle diameter of the spherical phosphor can be measured using a laser diffraction / scattering particle size distribution analyzer (for example, LS13320, manufactured by Beckman Coulter, Inc.).

  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 an esterified product of a substance having a hydroxyl group and an ethylenically unsaturated group (for example, β-hydroxyethyl (meth) acrylate); urethane (meth) acrylate (for example, tolylene diisocyanate and 2-hydroxyethyl (meth) acrylic) A reaction product with an acid ester, a reaction product of trimethylhexamethylene diisocyanate, cyclohexanedimethanol and 2-hydroxyethyl (meth) acrylate ester); an acrylic group in which a hydroxyl group, an epoxy group, a halogen group or the like is substituted on these alkyl groups acid Conversion alkyl esters or methacrylic 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.

  As the vinyl compound in the present invention, at least one selected from alkyl acrylates and alkyl methacrylates is preferably used, and at least one selected from methyl acrylate, methyl methacrylate, ethyl acrylate, and ethyl methacrylate. More preferably, seeds are used.

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, an organic peroxide that generates free radicals by heat is preferable.
Examples of the organic oxide include isobutyl peroxide, α, α′bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, di-n-propylperoxydicarbonate, and di-s-butyl. Peroxydicarbonate, 1,1,3,3-tetramethylbutylneodecanoate, bis (4-t-butylcyclohexyl) peroxydicarbonate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, Di-2-ethoxyethyl peroxydicarbonate, bis (ethylhexylperoxy) dicarbonate, t-hexyl neodecanoate, dimethoxybutyl peroxydicarbonate, bis (3-methyl-3-methoxybutylperoxy) dicarbonate , T-Butylperoxyneo Decanoate, 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-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-trimethylhexanoate, t -Butyl peroxylaurate, 2,5-dimethyl-2,5-bis (m-toluoyl peroxy) Sun, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t- Butyl peroxyacetate, 2,2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl-4,4-bis (t-butylperoxy) valerate, di-t-butylper Oxyisophthalate, 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, , 5-dimethyl-2,5-bis (t-butylperoxy) hexyne, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroper Oxide, t-hexyl hydroperoxide, t-butyl hydroperoxide, 2,3-dimethyl-2,3-diphenylbutane, and the like can be used.

  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 0.1 to 15 parts by mass with respect to 100 parts by mass of the vinyl compound, and is preferably used at 0.5 to 10 parts by mass.

The spherical phosphor in the present invention is prepared by mixing the above-described fluorescent substance and vinyl compound, and radical polymerization initiators such as peroxide, if necessary, and dissolving or dispersing the fluorescent substance in the vinyl compound to polymerize it. It is obtained by doing. There is no restriction | limiting in particular as a mixing method, For example, what is necessary is just to carry out by stirring.
The content of the fluorescent substance is preferably 0.001 to 30 parts by mass, more preferably 0.01 to 20 parts by mass, and 0.01 to 10 parts by mass with respect to 100 parts by mass of the vinyl compound. More preferably it is.

(Sealing resin)
In the present invention, the wavelength conversion type solar cell encapsulant serves as a base resin and encapsulating resin to which a spherical phosphor is dispersed and adhered. Specific examples of the sealing resin include acrylic resin, polycarbonate resin, polystyrene resin, polyolefin resin, polyvinyl chloride resin, polyether sulfone resin, polyarylate resin, polyvinyl acetal resin, epoxy resin, silicone resin, Examples thereof include fluororesins and copolymers thereof.
The sealing resin may be used alone or in combination of two or more.

  Examples of the acrylic resin include (meth) acrylic acid ester resins. Examples of the polyolefin resin include polyethylene and polypropylene. Examples of the polyvinyl acetal resin include polyvinyl formal, polyvinyl butyral (PVB resin), and modified PVB.

  Moreover, (meth) acrylic acid ester resin means what has a structural unit derived from acrylic acid ester or methacrylic acid ester, As acrylic acid alkyl ester or methacrylic acid alkyl ester, for example, acrylic acid unsubstituted alkyl Examples include esters or methacrylic acid unsubstituted alkyl esters, and acrylic acid-substituted alkyl esters and methacrylic acid-substituted alkyl esters in which a hydroxyl group, an epoxy group, a halogen group, or the like is substituted on these alkyl groups.

The acrylic acid ester or methacrylic acid ester is preferably an alkyl ester having 1 to 10 carbon atoms of acrylic acid or methacrylic acid, and more preferably an alkyl ester having 2 to 8 carbon atoms.
Specific examples of the acrylic ester or methacrylic ester include ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, methyl acrylate, Examples thereof include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, cyclohexyl acrylate, phenyl acrylate, and benzyl acrylate.

  The (meth) acrylic acid ester resin may be a copolymer using an unsaturated monomer copolymerizable with an acrylic acid ester or a methacrylic acid ester.

Examples of the unsaturated monomer include unsaturated acids such as methacrylic acid and acrylic acid; styrene, α-methylstyrene, acrylamide, diacetone acrylamide, acrylonitrile, methacrylonitrile, maleic anhydride, phenylmaleimide, cyclohexylmaleimide, and the like. And two or more of them can be used as necessary.
These unsaturated monomers can be used alone or in combination of two or more.

  Among these, (meth) acrylic acid ester resins include methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and n-butyl methacrylate. What has the structural unit derived from is preferable, and what has the structural unit derived from methyl methacrylate from a durable or versatile viewpoint is more preferable.

  Examples of the copolymer resin include (meth) acrylic acid ester-ethylene copolymer, (meth) acrylic acid ester-styrene copolymer, ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA), and the like. Can be mentioned.

  As the sealing resin, EVA is preferable in terms of moisture resistance, cost, and versatility, and (meth) acrylic ester resin is preferable in terms of durability and surface hardness. Furthermore, the combined use of EVA and (meth) acrylic ester resin is more preferable from the viewpoint of combining the advantages of both.

As EVA, the content of vinyl acetate units is preferably 1 to 50% by mass, and preferably 3 to 35% by mass from the viewpoint of adhesion of the spherical phosphor to the sealing resin.
In addition, from the viewpoint of sheet molding, the content of vinyl acetate units in EVA is preferably 10 to 50% by mass, and more preferably 20 to 35% by mass.
As EVA, commercially available products can be applied. Examples of commercially available products include Ultrasen (registered trademark) manufactured by Tosoh Corporation, Everflex (registered trademark) manufactured by Mitsui DuPont Polychemical Co., Ltd., Asahi Kasei Chemicals Corporation Suntech EVA manufactured by the company ("Suntech" is a registered trademark), UBE EVA copolymer manufactured by Ube Maruzen Polyethylene Co., Ltd., Evaate (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., Novatec EVA manufactured by Nippon Polyethylene Co., Ltd. Trademark).

  When EVA and methyl methacrylate are used in combination, the content of EVA is preferably 50 parts by mass or more and more preferably 70 parts by mass or more with respect to 100 parts by mass of the total amount of EVA and methyl methacrylate. preferable.

Furthermore, the sealing resin may be a resin having a crosslinked structure by adding a crosslinkable monomer.
As a 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 (having 2 to 14 ethylene groups), 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 Relate, 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 group Compounds obtained by adding α, β-unsaturated carboxylic acid to the containing compound (for example, trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether diacrylate, etc.); polyvalent carboxylic acid (for example, phthalic anhydride) ) And a substance having a hydroxyl group and an ethylenically unsaturated group (for example, β-hydroxyethyl (meth) acrylate); urethane (meth) acrylate (for example, tolylene diisocyanate and 2-hydro Shiechiru (meth) reaction product of an acrylic acid ester, a reaction product of trimethylhexamethylene diisocyanate and cyclohexanedimethanol and 2-hydroxyethyl (meth) acrylate, etc.); and the like.

Particularly preferred crosslinking monomers include trimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and bisphenol A polyoxyethylene dimethacrylate.
In addition, the said crosslinkable monomer is used individually by 1 type or in combination of 2 or more types.

The sealing resin can be polymerized by adding a radical polymerization initiator to the monomer and heating or irradiating with light, or can have a crosslinked structure.
As the radical polymerization initiator, a commonly used radical polymerization initiator can be used without any particular limitation. For example, the above-mentioned peroxides can be mentioned.

  The weight average molecular weight of the sealing resin is preferably 10,000 to 100,000, more preferably 10,000 to 50,000 from the viewpoint of fluidity.

  In the present invention, the wavelength conversion type solar cell encapsulant has, in addition to the above, an ultraviolet absorber, a coupling agent, a plasticizer, a flame retardant, an antioxidant, a light stabilizer, a rust inhibitor, A processing aid or the like may be contained.

In the present invention, the wavelength-converting solar cell encapsulant is, for example, a sheet-like composition obtained by melting and kneading an encapsulating resin and, if necessary, other additives, in a roll, a twin-screw extruder, a calendar molding machine, or the like. A method of spraying the spherical phosphor with a particle spraying device using this as a base material, or adjusting a transparent resin solution and dispersing the spherical phosphor, then the sheet-shaped sealing resin (sheet And a method of applying and removing the solvent with a doctor blade, a bar coater, a brush or the like. Here, the transparent resin solution is not particularly limited, and may be a solution in which the sealing material composition is dissolved in a solvent such as toluene or xylene, or a solution in which polymethyl methacrylate is dissolved in a solvent.
Specifically, the sealing material composition is formed into a sheet by a twin-screw extruder (T-die), a calendar molding machine, etc., and the sheet surface is melted by heat, using a dry particle spraying device. A wavelength conversion type solar cell sealing material is obtained by spraying the wavelength conversion fluorescent material.

  Any method may be used as a method of dispersing and fixing the spherical phosphor on the surface of the sheet-shaped sealing resin (sheet-shaped resin), but the method as shown in FIGS. Is preferably used.

<Solar cell module>
In the present invention, as shown in FIG. 1, the solar cell module includes an antireflection film (not shown), a protective glass 20, the wavelength conversion type solar cell sealing material 30 described above, the solar cell 10, and a back surface seal. It is composed of necessary members such as a stopper 35, a back film 50, a cell electrode (not shown), a tab line (not shown), and the like.

  Among these members, those existing on the light incident side from the solar battery cell 10 are an antireflection film (not shown), protective glass 20, and the wavelength conversion type solar battery sealing material 30 of the present invention. They are provided in this order.

  In the solar cell module of the present invention, the external light entering from all angles has low reflection loss and is efficiently introduced into the solar cell. Therefore, the refractive index of the wavelength conversion type solar cell encapsulant 30 is the wavelength conversion type. The light transmitting layer disposed on the light incident side from the solar cell encapsulant 30, that is, the refractive index of the antireflection film, the protective glass 20, etc. is higher than the wavelength conversion type solar cell encapsulant 30. It is preferable to make it lower than the refractive index of the solar cell 10 made of a light transmissive layer arranged on the side, that is, a cell antireflection film (not shown) and Si or the like.

That is, in the solar cell module of the present invention, the solar cell 10 and the layer provided on the light incident side from the solar cell 10 (for example, the protective glass 20 and the antireflection film provided on the light incident side from the protective glass 20 ( The refractive index of the layer provided on the side close to the solar battery cell 10 is preferably equal to or higher than the refractive index of the layer provided on the light incident side adjacent thereto. .
Specifically, the solar cell 10 and the layer provided on the light incident side from the solar cell 10 are composed of m layers (m is 2 or more), and the refractive indexes of the m layers are determined from the light incident side. order _{n 1, n 2, ···,} when the _{n m-1, n m,} n 1 ≦ n 2 ≦ ···· ≦ n m-1 ≦ n m holds it is desirable. In addition, when the wavelength conversion type solar cell sealing material 30 is comprised by the sealing material of 2 layers or more, it is desirable that the refractive index of a 2 layer sealing material also satisfy | fills the said relationship.

  Specifically, the refractive index of the light-transmitting layer disposed on the light incident side from the wavelength conversion type solar cell encapsulant 30, that is, the antireflection film, is 1.25 to 1.45, and the refractive index of the protective glass 20. The rate is usually about 1.45 to 1.55. The refractive index of the light-transmitting layer disposed on the light-incident side of the wavelength conversion type solar cell encapsulant, that is, the cell antireflection film of the solar cell, is usually about 1.9 to 2.1, and the solar cell The refractive index of the Si layer or the like constituting the cell is usually about 3.3 to 3.4.

In addition, the preferable refractive index of the other layer of a light transmissive layer is as showing below. For example, when the three layers from the light incident side of the light transmitting layer are the a layer, the b layer, and the c layer, the refractive indexes na, nb, and nc of the respective layers satisfy or satisfy the following formula (1). It is preferable.
nb = (na · nc) ^0.5 (1)

The entire contents of Japanese application 2010-120647 are incorporated herein by reference.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually described to be incorporated by reference, Incorporated herein by reference.

  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, “%” and “part” are based on mass.

[Example 1]
<Synthesis of fluorescent substances>
<Synthesis of FTP [1- (4-fluorophenyl) -3- (2-thienyl) -1,3-propanedione]>
0.96 g (0.04 mol) of sodium hydride was weighed, and 22.5 ml of dehydrated tetrahydrofuran was added under a nitrogen atmosphere. While vigorously stirring, a solution prepared by dissolving 2.52 g (0.02 mol) of 2-acetylthiophene and 3.70 g (0.024 mol) of methyl 4-fluorobenzoate in 12.5 ml of dehydrated tetrahydrofuran was added dropwise over 1 hour. . Thereafter, the mixture was refluxed for 8 hours under a nitrogen stream. This was returned to room temperature (25 ° C., hereinafter the same), 10 g of pure water was added, and 5.0 ml of 3N hydrochloric acid was further added. The organic layer was separated and concentrated under reduced pressure. The concentrate was recrystallized to obtain 2.83 g of FTP (57% yield).

<Synthesis of Eu (FTP) ₃ Phen>
FTP556.1 mg (2.24 mmol) and 1,10-phenanthroline (Phen) 151.4 mg (0.84 mmol) synthesized as described above were dispersed in 25.0 g of methanol. A solution prepared by dissolving 112.0 mg (2.80 mmol) of sodium hydroxide in 10.0 g of methanol was added to this dispersion, followed by stirring for 1 hour.
Subsequently, a solution obtained by dissolving 256.5 mg (0.7 mmol) of europium (III) chloride hexahydrate in 5.0 g of methanol was added dropwise. After stirring at room temperature for 2 hours, the produced precipitate was filtered by suction, washed with methanol, and dried to obtain Eu (FTP) ₃ Phen.

<Preparation of spherical phosphor>
The above fluorescent substance Eu (FTP) ₃ Phen 2.14 mg (0.05% monomer) and dilauroyl peroxide (LPO) 21.4 mg (0.50% monomer) were added to 42.86 g of methyl methacrylate (MMA). Dissolved. This monomer solution was put into 300 g of an aqueous solution containing 0.42 g of polyvinyl alcohol (based on 1.00% monomer), and was bubbled with nitrogen at room temperature while stirring at 350 rpm with a half moon blade. After raising the temperature to 60 ° C., polymerization was carried out at this temperature for 4 hours. Thereafter, in order to eliminate the remaining radical initiator, the temperature was further raised to 80 ° C. and stirred for 2 hours to complete the reaction. After returning to room temperature, the produced spherical phosphor was filtered off, washed thoroughly with pure water, and dried at 60 ° C. to obtain a spherical phosphor. When the average particle size of the spherical phosphor was measured with a laser diffraction / scattering particle size distribution analyzer, manufactured by Beckman Coulter, LS13320, the volume average particle size was 104 μm.

<Preparation of resin composition for sealing sheet (sealing resin)>
100 parts by mass of ethylene-vinyl acetate resin (EVA): NM30PW manufactured by Tosoh Corporation as a transparent dispersion medium resin, a peroxide thermal radical polymerization initiator manufactured by Arkema Yoshitomi Co., Ltd. (in this example, it also functions as a crosslinking agent) ): 1.3 parts by mass of Luperox 101 ("Lupelox" is a registered trademark), Silane coupling agent manufactured by Toray Dow Corning Co., Ltd .: 0.35 parts by mass of SZ6030, Cross-linking agent manufactured by Nippon Kasei Co., Ltd .: TAIC 1.2 parts by mass, light stabilizer manufactured by Toyotsu Chemiplus Co., Ltd .: 0.12 parts by mass of Tinuvin 770DF, antioxidant manufactured by API Corporation: Yoshinox BHT ("Yoshinox" is a registered trademark): 0. 007 parts by mass was kneaded with a roll mill at 90 ° C. to obtain a resin composition for a sealing sheet (sealing resin).

<Preparation of sealing sheet (sheet-shaped resin)>
A sealing sheet having a thickness of about 600 μm was obtained using a manual heating and stretching machine manufactured by Imoto Seisakusho, which was obtained by sandwiching the resin composition for sealing sheet obtained above with about 25 g of a release sheet and adjusting the roll part to 90 ° C. Sheet resin) was prepared.

<Production of wavelength conversion type solar cell sealing material>
As a method corresponding to FIG. 3, the sealing sheet (sheet-shaped resin) is cut into 200 mm × 200 mm, and 0.04 g of the spherical phosphor is formed on the sheet using a sieve having an opening of 120 μm. Resin) was uniformly sprayed. Using a manual heating and stretching machine manufactured by Imoto Seisakusho with the roll portion adjusted to 90 ° C., a spherical phosphor is embedded in a sheet (sheet-shaped resin), and the sheet (sheet-shaped resin) is cooled and fixed to convert the wavelength conversion solar cell. A sealing material was obtained.

<Preparation of solar cell encapsulating sheet for back surface>
The composition is the same as that for producing the sealing sheet (sheet-like resin), and the same method except that the thickness is changed to 400 μm by adjusting the gap between rolls of a manual heating and stretching machine manufactured by Imoto Seisakusho. The solar cell sealing sheet for back surfaces was produced.

<Production of wavelength conversion type solar cell module>
On the tempered glass (manufactured by Asahi Glass Co., Ltd.) as the protective glass, the wavelength conversion type solar cell encapsulant is placed so that the surface where the spherical phosphor is not dispersed is in contact with the tempered glass. A solar cell that can be taken out is placed (so that the surface on which the spherical phosphor of the wavelength conversion type solar cell encapsulant is dispersed is in contact with the solar cell), and a solar cell encapsulating sheet for the back surface, and A PET film (trade name: A-4300, manufactured by Toyobo Co., Ltd.) is placed as a back film, and a hot plate 150 using a vacuum pressurizing laminator for solar cells (Nen PC Co., Ltd., LM-50x50-S). The solar cell module of Example 1 was manufactured by laminating under the conditions of ° C., vacuum 10 minutes, and pressure 15 minutes.

  The photovoltaic cell in which the electromotive force can be taken out is a conductive film for solar cell manufactured by Hitachi Chemical Co., Ltd., CF-105, and a tab wire (thickness 0.14 mm, width) by a dedicated crimping device. 2 mm, galvanized 2) front and back 2 are connected, and each of these front and back is made an external lead wire using a horizontal tab wire (Hitachi Cable Co., Ltd., A-TPS 0.23 × 6.0). It is a solar battery cell. Moreover, about the photovoltaic cell which enabled taking out electromotive force outside, before modularizing, it uses the solar simulator XES-155S made from Mitsunaga Electric Co., Ltd., IV curve tracer made from ADCMT, ADC 6244, and photovoltaic cell I -V characteristics were obtained. The short-circuit current density Jsc was Jsc (cell) obtained by measurement according to JIS-C-8914.

[Evaluation of solar cell module]
The wavelength conversion type solar cell module produced above is obtained using a solar simulator XES-155S manufactured by Mitsunaga Electric Manufacturing Co., Ltd., an IV curve tracer manufactured by ADCMT, ADC 6244, and a solar cell IV characteristic is obtained and conforms to JIS-C-8914 Then, the short-circuit current density Jsc was measured, and the obtained value was defined as Jsc (module). ΔJsc was calculated from the following equation (2) using this value and Jsc (cell) measured in advance.
ΔJsc = Jsc (module) −Jsc (cell) (2)
The results obtained are summarized in Table 1.

[Example 2]
In the production of the wavelength conversion type solar cell encapsulant in Example 1, as a method corresponding to FIG. 5, the above-mentioned encapsulating sheet (sheet-like resin) is cut into 200 mm × 200 mm and placed on a stainless steel plate, 90 It was heated and softened for 8 minutes on a hot plate adjusted to ° C. This is placed on a mold having a hemispherical convex shape with a diameter of 200 μm arranged at a pitch of 0.7236 mm in vertical and horizontal intervals, pressurized with a hand roller from the stainless steel plate side, cooled, and the sheet is taken from the mold and the stainless steel plate. It peeled and the sealing sheet (sheet-like resin) which had innumerable concave shape was obtained. This was further placed on a stainless steel plate, and 0.08 g of the above spherical phosphor was uniformly dispersed on the sheet (sheet-shaped resin) using a sieve having a mesh size of 120 μm, and a squeegee. The excess spherical phosphor was removed by the method so that the spherical phosphor could fit in the recess. Furthermore, it heated and softened on the hotplate adjusted to 90 degreeC for 8 minutes, the spherical fluorescent substance was fixed, and the wavelength conversion type solar cell sealing material was adjusted. Further, the production and evaluation of the solar cell encapsulating sheet for the back surface, the production of the wavelength conversion type solar cell module, and the evaluation of the solar cell module in Example 1 were carried out and evaluated, and the obtained results are summarized in Table 1.

[Example 3]
In the production of the wavelength conversion type solar cell encapsulant in Example 1, as a method corresponding to FIG. 6, the above-mentioned encapsulating sheet (sheet-like resin) is cut into 200 mm × 200 mm and placed on a stainless steel plate. A plate (mask mesh) having a thickness of 150 μm, a through-hole diameter of 200 μm, and a pitch of 0.7236 mm arranged at vertical and horizontal intervals is placed, and 0.08 g of the above-described spherical phosphor is masked (mask mesh) using a sieve having an opening of 120 μm. ) Spread uniformly over the surface, remove excess spherical phosphor by squeegee method, heat and soften on hot plate adjusted to 90 ° C for 8 minutes to fix the spherical phosphor, then plate (mask mesh) The wavelength conversion type solar cell sealing material was adjusted. Further, the production and evaluation of the solar cell encapsulating sheet for the back surface, the production of the wavelength conversion type solar cell module, and the evaluation of the solar cell module in Example 1 were carried out and evaluated, and the obtained results are summarized in Table 1.

[Example 4]
In the production of the wavelength conversion type solar cell encapsulant in Example 1, as a method corresponding to FIG. 7 (and FIG. 4), a mold in which holes having a diameter of 200 μm and a depth of 150 μm are arranged with a pitch of 0.7236 mm at vertical and horizontal intervals. 0.08 g of the above spherical phosphor was uniformly sprayed on the mold using a sieve having a mesh size of 120 μm, and excess spherical phosphor was removed by a squeegee method. On the other hand, the sealing sheet (sheet-shaped resin) is cut into 200 mm × 200 mm, placed on a stainless steel plate, heated and softened on a hot plate adjusted to 90 ° C. for 8 minutes, and then sealed sheet (sheet-shaped resin). ) With the surface facing down, place on the mold, press with a hand roller from the stainless steel plate side, cool, peel off the sheet (sheet-like resin) from the mold and the stainless steel plate, wavelength conversion type solar cell encapsulant Adjusted. Further, the production and evaluation of the solar cell encapsulating sheet for the back surface, the production of the wavelength conversion type solar cell module, and the evaluation of the solar cell module in Example 1 were carried out and evaluated, and the obtained results are summarized in Table 1.

[Comparative Example 1]
<Preparation of resin composition for sealing sheet>
In adjustment of the resin composition for sealing sheets in Example 1, the resin composition for sealing sheets was adjusted with the same method except having added 1 mass part of spherical fluorescent substance.

<Production of wavelength conversion type solar cell sealing material>
A wavelength conversion type solar cell having a thickness of about 600 μm by a press machine obtained by sandwiching the resin composition for a sealing sheet obtained above with about 25 g of a release sheet and using a stainless steel spacer and adjusting a hot plate to 90 ° C. A sealing material was produced.

  Further, the production and evaluation of the solar cell encapsulating sheet for the back surface, the production of the wavelength conversion type solar cell module, and the evaluation of the solar cell module in Example 1 were carried out and evaluated, and the obtained results are summarized in Table 1.

  As can be seen in Table 1, if the wavelength conversion type solar cell encapsulant is formed by dispersing and adhering a fluorescent material to the surface in contact with the solar cell at the time of producing the solar cell module, the film thickness direction of the encapsulant It was proved that the wavelength conversion effect was higher than that in which the spherical phosphor was uniformly dispersed.

DESCRIPTION OF SYMBOLS 10 Solar cell, 20 Protection glass, 30 Wavelength conversion type solar cell sealing material, 35 Back surface sealing material, 40 Spherical fluorescent substance, 50 Back film, 30 Wavelength conversion type solar cell sealing material, 31 Sheet-like resin ( Sealing resin), 40 spherical phosphor, 60 heating / pressurizing roll, 61 gravure roll, 62 convex roll (embossing roll), 70 spherical phosphor quantitative supply device, 71 heating device, 72 squeegee device, 80 plate (Mask mesh), 81 Mask squeegee device, 82 Spherical phosphor arrangement mold, 83 Pressure plate.

Claims (9)

  A wavelength conversion type having a step of forming a spherical phosphor containing a fluorescent material two-dimensionally on a surface in contact with a solar battery cell during the production of a solar battery module, and attaching and adhering it to a sheet-shaped encapsulant surface Manufacturing method of solar cell sealing material.   In the process of forming and adhering the spherical phosphor in a two-dimensional manner, the sheet-shaped resin is softened using a heating / pressurizing roll, the spherical phosphor is sprayed thereon, and the heating / pressurizing roll is used again. The manufacturing method of the wavelength conversion type solar cell sealing material of Claim 1 formed by fixing a spherical fluorescent substance to a sheet | seat.   In the process of forming and attaching the spherical phosphor in a two-dimensional manner, the spherical phosphor is supplied onto a heating / pressurizing roll having a concave shape on the surface, and at the same time the sheet-like resin is softened. The method for producing a wavelength conversion type solar cell encapsulant according to claim 1, wherein the spherical phosphor is dispersed and fixed on the surface.   In the process of forming and attaching spherical phosphors two-dimensionally, using a heating / pressurizing roll with a convex shape on the surface, the sheet-like resin is softened to create dents, and then the spherical phosphors are spread on top. The method for producing a wavelength conversion type solar cell encapsulant according to claim 1, wherein the method is formed by fixing by reheating.   In the process of forming and attaching spherical phosphors two-dimensionally, a plate is placed on the sheet-like resin, and the spherical phosphors are spread on the plate by squeegeeing and fixed by heating. The manufacturing method of the wavelength conversion type solar cell sealing material of Claim 1.   In the process of forming and adhering the spherical phosphor in a two-dimensional manner, the spherical phosphor is placed on a mold having a dent that can hold the spherical phosphor, and this is pressed from under the sheet-like resin, And the manufacturing method of the wavelength conversion type solar cell sealing material of Claim 1 formed by fixing by pressurization and heating with a pressurization plate from the sheet-like resin upper side of the other side.   The method for producing a wavelength conversion type solar cell encapsulant according to any one of claims 1 to 6, wherein the fluorescent substance contained in the spherical phosphor is a europium complex.   The manufacturing method of the wavelength conversion type solar cell sealing material in any one of Claims 1-6 in which the fluorescent substance contained in a spherical fluorescent substance is included in the resin particle which uses a vinyl compound as a monomer compound.   The wavelength conversion type solar cell sealing material obtained by the manufacturing method of the wavelength conversion type solar cell sealing material in any one of Claims 1-8 provided in the light-receiving surface side of the solar cell and the said photovoltaic cell. And a solar cell module.

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