JP2006190867A - Solar cell encapsulant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in temperature of a solar cell element based on infrared rays by blending a specific additive without substantially adversely affecting the transparency and flexibility of a solar cell encapsulant, and generating power of the solar cell A prescription that suppresses the decrease in efficiency is provided.
An ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid unit content of 4% by weight or more and a melting point of 85 ° C. or higher, or an ionomer (A) thereof, and at least a wavelength region of 1200 to 3000 nm. It contains a transmission wavelength selection agent (B) that shields infrared rays, and the blending ratio of the transmission wavelength selection agent (B) to 100 parts by weight of the ethylene / unsaturated carboxylic acid copolymer or its ionomer (A) is 0.01 to 10%. The solar cell sealing material which consists of a resin composition which is a weight part, and a solar cell module using the same.
[Selection figure] None

Description

  The present invention relates to a solar cell encapsulant that suppresses a decrease in power generation efficiency based on a temperature rise. In particular, it is related with the solar cell sealing material useful as a sealing material of a concentrating solar cell module.

  Hydroelectric power generation, wind power generation, and solar power generation, which use inexhaustible natural energy to reduce carbon dioxide and improve other environmental problems, are in the spotlight. Among these, solar power generation has seen remarkable improvements in performance, such as power generation efficiency of solar cell modules, but the price has declined and the national and local governments have promoted the introduction of residential solar power generation systems. Its spread is remarkably advanced. However, further cost reduction is necessary for further dissemination, and research for further improvement of power generation efficiency is continued day and night.

  In general, it has been a problem that the power generation efficiency of solar cells decreases at a high temperature. In particular, it is considered that the temperature of a concentrating solar cell is likely to increase, and the power generation efficiency is greatly decreased.

JP-A-10-56189 JP 2003-69068 A

  Therefore, an object of the present invention is to blend specific additives without substantially adversely affecting the transparency and flexibility of the solar cell encapsulant, thereby suppressing the temperature rise of the solar cell element and improving the power generation efficiency. The goal is to improve.

  That is, the present invention is an ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid unit content of 4% by weight or more and a melting point of 85 ° C. or higher, or its ionomer (A-1), and at least 1200 to 3000 nm. It contains a transmission wavelength selection agent (B) that shields infrared rays in the wavelength region, and the blending ratio of the transmission wavelength selection agent (B) to 100 parts by weight of the ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1) is It is related with the solar cell sealing material which consists of a resin composition (C) which is 0.01-10 weight part. The transmission wavelength selector (B) is preferably at least one inorganic material selected from metal oxides, gold and silver, in particular indium oxide, tin oxide, zinc oxide, magnesium oxide, antimony oxide and two or more of these. A metal oxide selected from metal oxides in which these metals are combined is preferred.

  The present invention also provides a layer of the resin composition (C), an ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid unit content of 4% by weight or more and a melting point of 85 ° C. or higher, or an ionomer thereof. It is related with the solar cell sealing material by which the layer of the resin composition (D) which contains (A-2) and does not contain a transmission wavelength selection agent (B) is laminated | stacked.

  As (A-1) and (A-2), both are ionomers or blends of ethylene / unsaturated carboxylic acid copolymers and ionomers, and those having an average neutralization degree of 1 to 30% are preferable.

The solar cell encapsulant of the present invention has a wavelength of 1200 nm or more that does not contribute to power generation but does not contribute to power generation without substantially impeding transmission of light in the wavelength region related to power generation in sunlight. Therefore, the temperature rise of the solar cell element in the solar cell module can be suppressed, and the decrease in power generation efficiency can be suppressed. In particular, when the material of the present invention is used as a sealing material for concentrating solar cells, the effect of improving the power generation efficiency is remarkably exhibited. The solar cell encapsulant of the present invention also has a crosslinking agent or silane coupling for the solar cell element, or when using glass as the upper protective material and metal as the lower substrate protective material. Excellent adhesion without using any agent, and excellent in transparency and heat resistance. In particular, by using selected ionomers as the components (A-1) or (A-1) and (A-2), for example, the storage elastic modulus at 150 ° C. is 10 ³ Pa or more, preferably 5 × 10. A sealing material having a light transmittance of 85% or more, preferably 90% or more can be easily obtained at ³ Pa or more. Moreover, since the use of a crosslinking agent can be omitted, the productivity in the solar cell module manufacturing process can be remarkably increased, and the manufacturing cost of the solar cell module can be greatly reduced.

  The solar cell encapsulating material of the present invention comprises an ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1) as a main component, and a transmission wavelength selector (B) that shields infrared rays in a wavelength region of at least 1200 to 3000 nm. ) Containing the resin composition (C). The ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1) has an unsaturated carboxylic acid unit content of 4% by weight or more, preferably 5 to 20% by weight. Or an ionomer thereof having a melting point by DSC of 85 ° C. or higher, preferably 90 to 110 ° C. Such a copolymer or its ionomer has an advantage of having excellent transparency without using an ethylene copolymer having a high comonomer content, as in the case of an ethylene / vinyl acetate copolymer.

  Here, examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, and acrylic acid or methacrylic acid is particularly preferable. As the above-mentioned ethylene / unsaturated carboxylic acid copolymer, a copolymer obtained by copolymerizing vinyl ester or (meth) acrylic acid ester may be used since it is effective for imparting flexibility. Since those containing these copolymer components have a low melting point, those containing a large amount cannot be used.

  Examples of the ionomer of the ethylene / unsaturated carboxylic acid copolymer in the present invention include alkali metals such as lithium and sodium, and polyvalent metals such as calcium, magnesium, zinc and aluminum. The advantage of using such an ionomer is transparency and high storage modulus at high temperatures. For example, it is desirable to use an ionomer having a degree of neutralization of about 80% or less. However, in view of adhesiveness and flexibility to glass or solar cell elements, an ionomer having a high degree of neutralization is used. Is not a good idea. For example, it is preferable to use those having a neutralization degree of 60% or less, particularly 30% or less.

  When the above copolymer having an unsaturated carboxylic acid unit content of less than 4% by weight or an ionomer thereof is used, a product having excellent transparency cannot be obtained, and adhesion to a solar cell element or the like is not good. It will be enough. Further, when the unsaturated carboxylic acid unit content is increased, more excellent transparency can be obtained. However, when the content is too large, the melting point is lowered and the hygroscopicity is increased. . In this invention, since melting | fusing point is prescribed | regulated as 85 degreeC or more, there exists a limit in the content.

  In the present invention, when a copolymer or ionomer having a melting point lower than 85 ° C. is used, the heat resistance is not sufficient, and when a solar cell module is produced by a thermocompression bonding method, a sealing material is used. Is not preferable because it may flow out more than necessary and cause burrs.

  The copolymer or ionomer (A-1) has an unsaturated carboxylic acid unit content of 5 to 20% by weight, preferably 7 to 17% by weight, considering the balance of transparency, adhesiveness and heat resistance. Use an ionomer of an ethylene / unsaturated carboxylic acid copolymer having a neutralization degree of 1 to 30%, preferably 5 to 20%, and a melting point of 90 to 110 ° C, preferably 92 to 105 ° C. Is particularly preferred. Alternatively, an ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid unit content of 5 to 20% by weight, preferably 7 to 17% by weight and a melting point of 90 to 110 ° C., and an unsaturated carboxylic acid unit content of 5 A blend of an ethylene / unsaturated carboxylic acid copolymer ionomer having a melting point of 90 to 110 ° C., comprising a metal component of the latter ionomer and an unsaturated carboxylic acid component of both. It is particularly preferable to use those having an average degree of neutralization of 1 to 30%, preferably 5 to 20%. Even when only the above ionomer is used, it is desirable to use two or more kinds of ionomers having an unsaturated carboxylic acid unit content of 1% by weight or more in combination. Further, as in the latter case, a copolymer and an ionomer are blended and used. Even in this case, it is preferable to use those having an unsaturated carboxylic acid unit content different by 1% by weight or more. Examples of the latter case include, for example, 20 to 95 parts by weight, preferably 50 to 80 parts by weight of an ethylene / unsaturated carboxylic acid copolymer having a melting point of 90 to 105 ° C., and the unsaturated carboxylic acid unit content is the same. Examples include a blend of 80 to 5 parts by weight, preferably 50 to 20 parts by weight of an ionomer that is 1% by weight or more lower than the polymer and has a melting point of 1 ° C. or more.

  The copolymer or its ionomer (A-1) also has a melt flow rate (MFR) at 190 ° C. under a load of 2160 g (JIS K7210-1999, the same shall apply hereinafter) of 0.1 to 500 g / 10 min. It is preferable to use the one with 200 g / 10 minutes. When using a material with a low MFR, there is an advantage that even if a material with a slightly lower melting point is used, there is an advantage that troubles due to the flow of the sealing material as described above hardly occur, but a material with an excessively low MFR is used. Then, workability deteriorates. On the other hand, if an excessively high MFR is used, the amount that protrudes from the end when adhering to the module and increases in the laminate increases, and it takes time and effort to remove it, resulting in poor production efficiency.

  In the present invention, a transmission wavelength selective agent (B) that contains the ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1) as a main component and shields infrared rays in the wavelength region of at least 1200 to 3000 nm. (A-1) The resin composition which mix | blended (B) in the ratio of 0.01-10 weight part with respect to 100 weight part is used as a solar cell sealing material. As the transmission wavelength selective agent (B), it is preferable to use at least one inorganic material selected from metal oxides, gold and silver, and particularly selected from indium oxide, tin oxide, zinc oxide, magnesium oxide and antimony oxide. It is preferable to use a metal oxide or a composite oxide of two or more metals selected from indium, tin, zinc, magnesium and antimony. As the inorganic material, it is well dispersed in a solar cell encapsulant with a small amount of addition, and absorbs infrared rays efficiently. Also, an ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1) is transparent. In order not to impair the properties, it is preferable to use ultrafine powder having a particle size of 1 μm or less, preferably about 500 nm or less. By using, as a solar cell encapsulant, a resin composition in which an appropriate amount of such a transmission wavelength selective agent (B) is blended with an ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1), a solar cell element Temperature rise is suppressed, and a decrease in power generation efficiency can be suppressed.

  Various additives can be blended in the resin composition constituting the solar cell encapsulant of the present invention, if necessary. Specific examples of such additives include silane coupling agents, UV absorbers, hindered phenol-based and phosphite-based antioxidants, hindered amine-based light stabilizers, light diffusing agents, flame retardants, and discoloration inhibitors. Etc. can be illustrated.

  A silane coupling agent is useful for improving the adhesion of a sealing material to a protective material, a solar cell element, and the like. Examples thereof include an amino group or an epoxy group and a hydrolyzable like an alkoxy group. The compound which has group can be mentioned. Specific examples of the silane coupling agent include N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, and γ-aminopropyltriethoxy. Examples include silane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like. The silane coupling agent is desirably blended in an amount of about 0.1 to 5 parts by weight with respect to 100 parts by weight of the ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1).

  Examples of the ultraviolet absorber that can be added to the solar cell encapsulant of the present invention include various types such as benzophenone-based, benzotriazole-based, triazine-based, and salicylic acid ester-based materials. Examples of the benzophenone-based UV absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-n. -Dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2 , 4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, etc. It is possible.

  The benzotriazole ultraviolet absorber is a hydroxyphenyl-substituted benzotriazole compound, for example, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-butylphenyl) Benzotriazole, 2- (2-hydroxy-3,5-dimethylphenyl) benzotriazole, 2- (2-methyl-4-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-3-methyl-5-t- Butylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-amylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, and the like. Can be mentioned. Examples of triazine ultraviolet absorbers include 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol, 2- ( And 4,6-diphenyl-1,3,5-triazin-2-yl) -5- (hexyloxy) phenol. Examples of salicylic acid esters include phenyl salicylate and p-octylphenyl salicylate.

  The solar cell encapsulant of the present invention contains the above-described ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1) and a transmission wavelength selective agent (B) as essential components, and optionally a silane coupling agent. In addition, it can be used in a single layer configuration of the resin composition (C) containing an additive such as an ultraviolet absorber. However, a layer of the resin composition (C), an ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid unit content of 4% by weight or more and a melting point of 85 ° C. or more, or an ionomer thereof (A-2) Can be used as a laminate comprising a layer of the resin composition (D) optionally containing additives such as a silane coupling agent and an ultraviolet absorber. As the resin composition (D), the same raw materials and blending amounts as those described for the resin composition (C) can be used except that the resin composition does not contain the transmission wavelength selective agent (B). In particular, it is preferable to use substantially the same (A-1) and (A-2), and it is preferable that the types and amounts of other additives are substantially the same. In the laminate, the thickness ratio [C] / [D] of the resin composition (C) layer and the resin composition (D) layer is preferably in the range of 1/99 to 90/10. The transmission wavelength selection agent (B) in the resin composition (C) is used when the resin composition (C) is used as a single layer, or a laminate of the resin composition (C) layer and the resin composition (D) layer. When using as a body, according to the thickness of (C) layer, what is necessary is just to mix | blend in an appropriate ratio within the above-mentioned range.

  A solar cell module can be produced by fixing the solar cell element with upper and lower protective materials using the solar cell encapsulant of the present invention. Examples of such solar cell modules include various types. For example, the upper transparent protective material / encapsulant / solar cell element / encapsulant / lower protective material sandwiched between the solar cell elements from both sides, formed on the inner peripheral surface of the lower substrate protective material A solar cell element formed on the inner peripheral surface of the upper transparent protective material, for example, a fluororesin-based transparent protective material. The thing of the structure which forms a sealing material and a lower protective material on what created the amorphous solar cell element by sputtering etc. can be mentioned.

  Solar cell elements include single-crystal silicon, polycrystalline silicon, amorphous silicon, and other silicon systems, and gallium-arsenic, copper-indium-selenium, cadmium-tellurium, and other III-V group and II-VI group compound semiconductor systems. Various solar cell elements can be used. The solar cell sealing material of the present invention is particularly useful as a sealing material for silicon-based solar cell elements.

  Examples of the upper protective material constituting the solar cell module include glass, acrylic resin, polycarbonate, polyester, and fluorine-containing resin. The lower protective material is a single or multilayer sheet such as metal or various thermoplastic resin films, for example, metals such as tin, aluminum, and stainless steel, inorganic materials such as glass, polyester, inorganic vapor deposition polyester, fluorine-containing resin And a single-layer or multilayer protective material such as polyolefin. The solar cell encapsulant of the present invention exhibits good adhesion to these upper or lower protective materials.

  The solar cell encapsulant of the present invention is usually used in a sheet form. The single-layer sheet-like solar cell encapsulant made of the resin composition (C) can be produced by a known sheet molding method using a T-die extruder, a calendar molding machine, or the like. For example, a transmission wavelength selector (B), a silane coupling agent, an ultraviolet absorber, an antioxidant, and a light stabilizer, which are added to an ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1) as necessary. An additive such as an agent can be dry blended in advance, supplied from a hopper of a T-die extruder, and extruded into a sheet. Of course, in these dry blends, some or all of the additives can be used in the form of a masterbatch. In addition, in T-die extrusion and calendering, a part or all of the additive is previously added to the ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1), a single screw extruder, a twin screw extruder, a Banbury mixer, A resin composition obtained by melt mixing using a kneader or the like can also be used. Moreover, the laminated sheet-like solar cell encapsulant composed of the resin composition (C) layer and the resin composition (D) layer is produced by a coextrusion method under the same conditions as described above, or It can be manufactured by creating single layer sheets and then laminating them. In the case of a single layer sheet, the sheet thickness is about 0.1 to 1 mm. In the case of a laminated sheet, the resin composition (C) layer is about 0.01 to 1 mm, and the resin composition (D) layer is 0.05. It is preferable that the total thickness is about 0.1 to 2 mm.

  In manufacturing a solar cell module, a sheet having the above-described configuration is formed by a method similar to the conventional method in which a sheet of the sealing material of the present invention is prepared in advance and pressure-bonded at a temperature at which the sealing material melts. be able to. In this case, since it is not necessary to contain an organic peroxide in the sealing material, it is possible to perform sheet molding of the sealing material at a high temperature with high productivity, and it is also necessary to go through a two-step bonding process in forming the module. It can be completed in a short time at a high temperature. It is preferable to use the sealing material of this invention for the light-receiving side of a solar cell element. Moreover, when using the lamination sheet-like solar cell sealing material which consists of a layer of the resin composition (C) and a resin composition (D), the layer of the resin composition (D) contacts a solar cell element. In addition, the layer of the resin composition (C) is preferably in contact with the surface protective material. Furthermore, if a method of laminating with the solar cell element, the upper protective material or the lower protective material by extrusion coating the sealing material of the present invention is adopted, a solar cell module can be manufactured in one step without bothering to form a sheet. Is possible. Therefore, if the sealing material of this invention is used, the productivity of a module can be improved significantly.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, the raw material used for the Example and the comparative example and the evaluation method of a physical property are as follows.

1. Raw material (1) Ethylene / unsaturated carboxylic acid copolymer and ionomer EMAA: Ethylene / methacrylic acid copolymer (methacrylic acid unit content 15% by weight, melt flow rate (190 ° C., 2160 g load, JIS K7210-1999, the same applies hereinafter) ) 25g / 10min)
IO-Zn: Zinc ionomer of ethylene / methacrylic acid copolymer having a methacrylic acid unit content of 15% by weight (zinc neutralization degree 21%, melt flow rate 16 g / 10 min)
(2) Transmission wavelength selection agent ITO: tin-doped indium oxide, average particle size 30 nm
(3) Silane coupling agent: γ-methacryloxypropyltrimethoxysilane (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.)

[Example 1]
A master batch (MB) of the EMAA containing 10% by weight of the ITO was prepared in advance. 3500 g of the above EMAA pellets, 1500 g of ITO masterbatch (MB) and 5 g of the above silane coupling agent (trade name: KBM503) were mixed and left overnight for impregnation. The resulting impregnated pellets were kneaded and molded at a processing temperature of 180 ° C. using a 30 mmφ inflation film molding machine to produce a 0.05 mm thick film (c-1).

  On the other hand, 5000 g of the EMAA pellets and 5 g of the silane coupling agent were mixed and left for a whole day and night for impregnation. A sheet (d) having a thickness of 0.5 mm was prepared from the obtained impregnated pellets using a 40 mmφ sheet molding machine.

Between 2 sheets of 3 mm thick blue glass, the 0.05 mm film (c-1) prepared above (containing 3% ITO) and a 0.5 mm sheet (d) (without ITO added) are sandwiched at 150 ° C. for 15 minutes. Bonding is performed with a vacuum bonding machine, and a transmittance of 650 nm that is a visible light region is measured with an ultraviolet spectrophotometer, and a transmittance of 2000 nm (5000 cm ⁻¹ ) that is an infrared region is measured with an infrared spectrophotometer. It was measured. The results are shown in Table 1.

[Example 2]
4850 g of the EMAA pellets, 150 g of MB containing 10% by weight of the ITO, and 5 g of the silane coupling agent (trade name: KBM503) were mixed and left overnight for impregnation. A sheet (c-2) having a thickness of 0.5 mm was prepared from the obtained impregnated pellets using a 40 mmφ sheet molding machine. A 0.5 mm sheet (c-2) obtained between two 3 mm-thick blue glasses is sandwiched and bonded with a vacuum bonding machine at 150 ° C. for 15 minutes, and visible light is measured with an ultraviolet spectrophotometer. The transmittance at 650 nm as the region and the transmittance at 2000 nm (5000 cm ⁻¹ ) as the infrared region were measured with an infrared spectrophotometer. The results are shown in Table 1.

[Example 3]
4150 g of the IO-Zn pellets, 150 g of MB containing 10% by weight of the ITO, and 5 g of the silane coupling agent (trade name: KBM503) were mixed and left overnight for impregnation. A sheet (c-3) having a thickness of 0.5 mm was prepared from the obtained impregnated pellets using a 40 mmφ sheet molding machine. A 0.5 mm sheet (c-3) obtained between two 3 mm-thick blue glasses is sandwiched and bonded with a vacuum bonding machine at 150 ° C. for 15 minutes, and visible light is measured with an ultraviolet spectrophotometer. The transmittance at 650 nm as the region and the transmittance at 2000 nm (5000 cm ⁻¹ ) as the infrared region were measured with an infrared spectrophotometer. The results are shown in Table 1.

[Comparative Example 1]
The 0.5 mm sheet (d) used in Example 1 was sandwiched between two 3 mm-thick blue glasses, bonded at 150 ° C. for 15 minutes with a vacuum bonding machine, and visible with an ultraviolet spectrophotometer. The transmittance at 650 nm, which is the light region, and the transmittance at 2000 nm (5000 cm ⁻¹ ), which is the infrared region, were measured using an infrared spectrophotometer. The results are shown in Table 1.

Claims (13)

  An ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid unit content of 4% by weight or more and a melting point of 85 ° C. or higher, or its ionomer (A-1), and infrared rays in the wavelength region of at least 1200 to 3000 nm. It contains a transmission wavelength selection agent (B) to be shielded, and the blending ratio of the transmission wavelength selection agent (B) with respect to 100 parts by weight of the ethylene / unsaturated carboxylic acid copolymer or its ionomer (A-1) is 0.01 to 10 The solar cell sealing material which consists of a resin composition (C) which is a weight part.   The solar cell encapsulating material according to claim 1, wherein the transmission wavelength selecting agent (B) is mainly composed of at least one inorganic material selected from metal oxide, gold and silver.   3. The solar cell sealing according to claim 2, wherein the metal oxide is selected from indium oxide, tin oxide, zinc oxide, magnesium oxide, antimony oxide and a metal oxide in which two or more of these metals are combined. Wood.   The solar cell encapsulant according to claim 2 or 3, wherein the inorganic substance is an ultrafine powder having a particle size of 1 µm or less.   The component (A-1) is an ionomer or a blend of an ethylene / unsaturated carboxylic acid copolymer and an ionomer, and the average degree of neutralization is in the range of 1 to 30%. Solar cell encapsulant.   The solar cell encapsulant according to claim 1, wherein the resin composition (C) further contains a silane coupling agent.   A layer of the resin composition (C) according to claim 1 and an unsaturated carboxylic acid unit content of 4% by weight or more and an ethylene / unsaturated carboxylic acid copolymer having a melting point of 85 ° C or higher or an ionomer thereof The solar cell sealing material formed by laminating | stacking the layer of the resin composition (D) which contains (A-2) and does not contain a transmission wavelength selection agent (B).   The solar cell encapsulant according to claim 7, wherein the component (A-2) is an ionomer or a blend of an ethylene / unsaturated carboxylic acid copolymer and an ionomer, and the average degree of neutralization is in the range of 1 to 30%. .   The solar cell sealing material according to claim 7 or 8, wherein a silane coupling agent is further blended with the resin composition (D).   The thickness ratio [C] / [D] of the layer of the resin composition (C) and the layer of the resin composition (D) is in the range of 1/99 to 90/10. The solar cell sealing material in any one.   It is a sheet form, The solar cell sealing material in any one of Claims 1-10.   The solar cell module using the solar cell sealing material in any one of Claims 1-11. The solar cell module according to claim 12, wherein the solar cell sealing material is used on a light receiving side of a solar cell element.