WO2014199892A1

WO2014199892A1 - Solar cell sealant composition and production method for same, solar cell sealant layer employing same, and solar cell module

Info

Publication number: WO2014199892A1
Application number: PCT/JP2014/064943
Authority: WO
Inventors: 洋毅千田; 久成尾之内
Original assignee: 日東電工株式会社
Priority date: 2013-06-14
Filing date: 2014-06-05
Publication date: 2014-12-18
Also published as: JP6178126B2; CN105308113A; JP2015000902A; CN105308113B; KR20160019921A

Abstract

The present invention relates to providing a solar cell sealant composition in which, at a molding temperature at which there is substantially no decomposition of organic peroxides, an organic compound additive having a melting point higher than the molding temperature has been uniformly dispersed in an ethylene copolymer, and to a production method for the same. The present invention also relates to a solar cell sealant layer in which an organic compound additive having a melting point higher than the molding temperature is uniformly dispersed in an ethylene copolymer, and to a solar cell module employing the same. Also provided is a production method for a solar cell sealant composition containing an ethylene copolymer (A) and an organic compound additive (B), wherein the production method for a solar cell sealant composition is characterized by including a step in which the ethylene copolymer (A) and the organic compound additive (B) are mixed, within a temperature range at or above the Vicat softening point of the ethylene copolymer, and at or below a temperature 10°C below the softening point of the ethylene copolymer (A).

Description

SOLAR CELL SEALING MATERIAL COMPOSITION, PROCESS FOR PRODUCING THE SAME, SOLAR CELL SEALING MATERIAL LAYER USING THE SAME, AND SOLAR CELL MODULE

The present invention relates to a solar cell encapsulant composition and a method for producing the same, and a solar cell encapsulant layer and a solar cell module using the same.

A solar cell module generally has a structure in which a glass substrate, a solar cell encapsulant, a power generation element, a solar cell encapsulant, and a back sheet are sequentially laminated. And the said solar cell sealing material uses the resin sheet which uses an ethylene-type copolymer as a matrix from viewpoints, such as low cost and high transmittance | permeability.

The ethylene copolymer contains an organic peroxide, a crosslinking aid and the like in order to improve durability. In addition, in order to provide weather resistance, a silane coupling agent is generally blended in order to ensure the adhesiveness of organic substances, glass, and solar cell elements having an absorption region in the ultraviolet region such as an ultraviolet absorber. ing.

The sheet-shaped solar cell encapsulant is molded by a T-die extrusion film forming machine or a calendar molding machine. For example, the above-mentioned additives are pre-dry blended into an ethylene copolymer, then supplied from a hopper of a T-die extruder, and extruded into a sheet at a molding temperature at which the organic peroxide is not substantially decomposed. There is a method (see, for example, Patent Document 1).

However, among the above additives, those having a melting point higher than the molding temperature do not melt, so that there is a problem that they are difficult to disperse uniformly in the ethylene-based copolymer. Therefore, it is necessary to melt the organic substance once at a temperature equal to or higher than the melting point. However, if a high melting point organic substance is melted at a temperature higher than the temperature at which the organic peroxide decomposes, the cross-linking reaction accompanying the decomposition of the organic peroxide starts and proceeds, causing defects such as bumps on the sheet surface. And may affect the final physical properties. There is also a method of improving dispersibility by increasing the screw rotation speed, but the resin temperature becomes high due to the effect of shearing heat generation, which may result in decomposition of the peroxide. For this reason, a method of dispersing a high-melting-point organic substance at a temperature or lower at which the organic peroxide is not decomposed is necessary.

As one means, a masterbatch is prepared by kneading only an organic substance having a high melting point above its melting point into the ethylene copolymer in advance using a melt kneader such as a twin-screw extruder, and the masterbatch is obtained as an ethylene copolymer. And a method of melting and kneading together with an organic peroxide at a low temperature to form a sheet. However, even with the above-described method, there are problems in that the number of master batch steps increases, resulting in an increase in cost due to material loss and deterioration of the ethylene-based copolymer itself due to an increase in thermal history.

JP 2006-186233 A

In light of such circumstances, the present invention is a solar in which an organic compound additive having a melting point higher than the molding temperature is uniformly dispersed in an ethylene copolymer at a molding temperature at which the organic peroxide is not substantially decomposed. It aims at providing the composition for batteries, and its manufacturing method.

The present invention also provides a solar cell encapsulant layer in which an organic compound additive having a melting point higher than the molding temperature is uniformly dispersed in an ethylene copolymer, and a solar cell module using the same. For the purpose.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found the following solar cell encapsulant composition and method for producing the same, and solar cell encapsulant layer and solar cell module using the same. Thus, the inventors have found that the above object can be achieved, and have completed the present invention.

The manufacturing method of the sealing material composition for solar cells of this invention is a manufacturing method of the sealing material composition for solar cells containing an ethylene-type copolymer (A) and an organic compound additive (B),
The ethylene copolymer (A) and the organic polymer are within a temperature range from the Vicat softening point of the ethylene copolymer (A) to 10 ° C. below the melting point of the ethylene copolymer (A). A blending step of mixing the compound additive (B) is included.

By using the method for producing a solar cell encapsulant composition of the present invention, an organic compound additive having a melting point higher than the molding temperature at an molding temperature at which the organic peroxide is not substantially decomposed is ethylene-based. It becomes possible to disperse uniformly in the coalescence. Further, even when a liquid additive is contained, a resin composition that does not block and that does not block the liquid component does not remain on the resin surface due to impregnation or dispersion inside the resin.

In the present invention, the dispersion state of the organic compound having a high melting point is improved by stirring and mixing in the above temperature range. On the other hand, when the temperature is below the Vicat softening point, the high melting point compound is difficult to adhere to the resin (particularly in the case of pellets), and when the temperature is not lower than 10 ° C. below the melting point, the resins block each other. End up. More specifically, when blending for a long time without controlling the temperature during the blending step (pre-blending) as in the past, the internal temperature increases due to friction between the pellets and rotating blades, friction between the pellets, and the like. Therefore, the resins may be blocked. On the other hand, by performing pre-blending within the above temperature range in the present invention, the above problem can be effectively avoided.

In the method for producing a solar cell encapsulant composition of the present invention, the ethylene copolymer (A) is preferably in the form of pellets. By using the above-described production method, an ethylene-based resin that is a matrix resin for a solar cell encapsulant layer, even if it is a pellet-shaped ethylene copolymer that is generally less likely to mix and disperse additives than powder. It becomes possible to disperse uniformly in the copolymer. Moreover, it becomes possible to use a pellet and the production workability of the solar cell sealing material composition is improved.

Note that the pellet shape means a particle shape having a diameter or length of about 1 to 10 mm mainly for improving workability, for example, a substantially cylindrical shape, a substantially spherical shape, a substantially disk shape, Examples thereof include grains having a substantially triangular prism shape, a substantially quadrangular prism shape, a substantially polyhedral shape, an elliptical spherical shape, and the like.

Moreover, in the manufacturing method of the sealing material composition for solar cells of this invention, in the said blending process, the organic peroxide (C) is further included, and melting | fusing point of the said organic compound additive (B) is said organic The temperature is preferably 10 ° C. or more lower than the one-hour half-life temperature of the peroxide (C). By using the production method of the present invention, the organic compound additive (B) having a melting point near or higher than the one-hour half-life temperature of the organic peroxide (C), which is usually difficult to disperse uniformly. However, the organic compound additive (B) can be uniformly dispersed in the ethylene copolymer without substantially decomposing the organic peroxide.

In the method for producing a solar cell encapsulant composition of the present invention, it is preferable that no solvent is used in the blending step. In the above production method, without using a separate solvent other than the components of the solar cell encapsulant composition such as a liquid additive (dry process), at a molding temperature at which the organic peroxide is not substantially decomposed, An organic compound additive having a melting point higher than the molding temperature can be uniformly dispersed in the ethylene-based copolymer.

Moreover, in the method for producing a solar cell encapsulant composition of the present invention, a liquid additive may be further included in the blending step. In the above production method, even when a liquid additive such as a silane coupling agent or a liquid crosslinking aid is contained, liquid components do not remain on the resin surface due to impregnation or dispersion inside the resin, and blocking is also possible. Can be obtained. A master batch can also be easily produced. In addition, the said liquid additive means the additive which is liquid at the time of a blending process, and the compound whose melting | fusing point is lower than the temperature at the time of a blending process corresponds.

Moreover, in the method for producing a solar cell encapsulant composition of the present invention, it is preferable to include a melt-kneading step after the blending step. A composition for a solar cell in which an organic compound additive having a melting point higher than the molding temperature after the melt-kneading step is uniformly dispersed in the ethylene copolymer can be easily obtained, rather than going through the blending step first. . Furthermore, by passing through the blending process first, a sheet having a high dispersibility of the organic compound having a high melting point can be formed even in a melt-kneading process at a temperature lower than usual.

Moreover, in the method for producing a solar cell encapsulant composition of the present invention, the melt kneading step is preferably performed by a single screw extruder, a twin screw extruder, a Banbury mixer, a kneader, or a mixing roll. By using the said structure, the said composition for solar cells in which the organic compound additive was uniformly disperse | distributed to the ethylene-type copolymer can be obtained more effectively. Moreover, it is preferable that the sheet is formed (formation of the sealing material layer) by calendar extrusion, T-die, or melt extrusion by inflation.

Moreover, in the manufacturing method of the sealing material composition for solar cells of this invention, the said organic compound additive (B) is a ultraviolet absorber, antioxidant, light stabilizer, anti-aging agent, or solid bridge | crosslinking. An auxiliary is preferred. By using the said compound, the sealing material layer for solar cells formed with the said composition can be made more multifunctional.

In the solar cell encapsulant composition of the present invention, it is preferable that the ethylene copolymer contains an ethylene-vinyl acetate copolymer as a main component. By using an ethylene-vinyl acetate copolymer as a main component as the ethylene-based copolymer, a solar cell encapsulant layer having more excellent light transmittance and durability can be obtained more reliably.

In addition, the said main component shall mean the case where 50 weight% or more is contained by weight ratio, when the matrix resin of the said solar cell sealing material composition is a mixture of several resin. The weight ratio is more preferably 70% by weight or more, and still more preferably 90% by weight or more.

On the other hand, the solar cell encapsulant layer of the present invention is characterized by being formed using the solar cell encapsulant composition. By forming using the said composition, it becomes the sealing material layer for solar cells in which the organic compound additive which has melting | fusing point higher than molding temperature was disperse | distributed uniformly in the ethylene-type copolymer.

Moreover, the solar cell module of the present invention is characterized by including a solar cell encapsulant layer formed using the solar cell encapsulant composition. Since the said solar cell module has the said solar cell sealing material layer, it becomes a solar cell module by which the organic compound additive which has melting | fusing point higher than molding temperature was uniformly disperse | distributed to the ethylene-type copolymer.

Further, in the solar cell module of the present invention, the solar cell is a crystalline silicon solar cell, a cadmium sulfide / cadmium telluride solar cell, a copper indium gallium diselenide solar cell, an amorphous silicon solar cell, or a microcrystalline silicon. A solar cell is preferred. The said solar cell module can improve photoelectric conversion efficiency more effectively by using it for the solar cell module which laminates | stacks the said photovoltaic cell.

The example of the solar cell module using the sealing material layer for solar cells of this invention is shown. The example of the solar cell module using the sealing material layer for solar cells of this invention is shown.

Hereinafter, embodiments of the present invention will be described.

(Encapsulant composition for solar cell)
The solar cell encapsulant composition of the present invention is characterized by containing at least an ethylene copolymer (A) and an organic compound additive (B). The solar cell encapsulant composition includes, for example, at least an organic compound additive (B) dispersed in an optically transparent matrix resin containing an ethylene copolymer (A) as a main component. Or the like.

Examples of the ethylene copolymer (A) include a copolymer of ethylene and a polar monomer, and a copolymer of ethylene and an α-olefin having 3 or more carbon atoms.

In the ethylene copolymer (A), the ethylene unit content is preferably 50 to 90% by weight, more preferably 60 to 80% by weight, and even more preferably 65 to 75% by weight. . By setting it as the said content, the sealing material for solar cells excellent in the softness | flexibility, transparency, a moldability, blocking resistance, and a solar cell element protective property can be obtained more reliably.

Examples of the polar monomer include vinyl esters such as vinyl acetate and vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, methyl methacrylate, methacrylic acid Unsaturated carboxylic acid esters such as isobutyl acid, dimethyl maleate, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, monomethyl maleate, monoethyl maleate, maleic anhydride, itaconic anhydride, and the like, and Examples of these salts include carboxylates. Examples of the carboxylic acid salt include monovalent metals such as lithium, sodium and potassium, and salts of polyvalent metals such as magnesium, calcium and zinc. These may be used singly or in combination of two or more.

Examples of the α-olefin having 3 or more carbon atoms include propylene, 1-butene, 2-butene, 1-hexene, 1-octene, 4-methyl-1-pentene and the like. These may be used singly or in combination of two or more.

Examples of the ethylene copolymer (A) include ethylene-vinyl ester copolymers such as ethylene-vinyl acetate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene -Methyl methacrylate copolymer, ethylene-isobutyl acrylate copolymer, ethylene-unsaturated carboxylic acid ester copolymer such as ethylene / n-butyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene -Methacrylic acid copolymer, ethylene-unsaturated carboxylic acid copolymer such as ethylene / isobutyl acrylate-methacrylic acid copolymer and its ionomer. These may be used singly or in combination of two or more.

The ethylene-based copolymer (A) preferably contains an ethylene-vinyl acetate copolymer as a main component. By using an ethylene-vinyl acetate copolymer as a main component as the ethylene-based copolymer, a solar cell encapsulant layer having more excellent light transmittance and durability can be obtained more reliably.

The ethylene-vinyl acetate copolymer (A) preferably has a vinyl acetate monomer unit content of 20 to 40 parts by weight with respect to 100 parts by weight of the ethylene-vinyl acetate copolymer, The content is more preferably 35 parts by weight, and the above content is preferable from the viewpoint of uniform dispersibility in a matrix resin such as a rare earth complex.

When using the ethylene-vinyl acetate copolymer (A), commercially available products can be used as appropriate. Examples of commercially available ethylene-vinyl acetate copolymers include Ultrasen (manufactured by Tosoh Corporation), Everflex (manufactured by Mitsui DuPont Polychemical Co., Ltd.), Suntec EVA (manufactured by Asahi Kasei Chemicals Corporation), UBE EVA copolymer ( Ube Maruzen Polyethylene Co., Ltd.), Evertate (Sumitomo Chemical Co., Ltd.), Novatec EVA (Nihon Polyethylene Co., Ltd.), Smitate (Sumitomo Chemical Co., Ltd.), Nipoflex (Tosoh Corp.), and the like. These may be used singly or in combination of two or more.

The refractive index of the ethylene-vinyl acetate copolymer (A) is, for example, in the range of 1.4 to 1.7, in the range of 1.45 to 1.65, or in the range of 1.45 to 1.55. is there. In some embodiments, the ethylene-vinyl acetate copolymer (A) has a refractive index of 1.5.

It is preferable to use an optically transparent matrix resin as the solar cell encapsulant composition. As said matrix resin, you may use suitably other matrix resin with the said ethylene-type copolymer (A), unless the characteristic of the said ethylene-type copolymer (A) is impaired. Examples of other matrix resins include polyolefins such as polyethylene terephthalate, poly (meth) acrylate, polyethylene tetrafluoroethylene, polyimide, amorphous polycarbonate, siloxane sol-gel, polyurethane, polystyrene, polyethersulfone, polyarylate And epoxy resins and silicone resins. These matrix resins may be used alone or in admixture of two or more.

In the matrix resin (the ethylene copolymer (A) alone or in combination with another matrix resin), a crosslinkable monomer may be added to obtain a resin having a crosslinked structure.

Examples of the crosslinkable monomer include compounds obtained by reacting α, β-unsaturated carboxylic acid with dicyclopentenyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, and polyhydric alcohol ( 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 propoxy tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane tetra (meth) acrylate, polypropylene glycol di (meth) acrylate (pro Having 2 to 14 pyrene 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.), a compound obtained by adding an α, β-unsaturated carboxylic acid to a glycidyl group-containing compound (for example, tri Methylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether diacrylate, etc.), polycarboxylic acid (for example, phthalic anhydride), a substance having a hydroxyl group and an ethylenically unsaturated group (for example, β- Esterified product with droxyethyl (meth) acrylate), alkyl ester of acrylic acid or methacrylic acid (for example, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic Acid 2-ethylhexyl ester), urethane (meth) acrylate (for example, reaction product of tolylene diisocyanate and 2-hydroxyethyl (meth) acrylic acid ester, trimethylhexamethylene diisocyanate, cyclohexanedimethanol and 2-hydroxyethyl (meth) A reaction product with an acrylate ester, etc.). These crosslinkable monomers may be used alone or in admixture of two or more. Of these, trimethylolpropane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and bisphenol A polyoxyethylene dimethacrylate are preferred as the crosslinkable monomer.

When a matrix resin containing the crosslinkable monomer is used, for example, a thermal polymerization initiator or a photopolymerization initiator can be added to the crosslinkable monomer, and polymerized and crosslinked by heating or light irradiation to form a crosslinked structure.

A known peroxide can be appropriately used as the thermal polymerization initiator. Examples of the thermoplastic resin polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane-3, Di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, dicumyl peroxide, α, α'-bis (t-butylperoxy) Isopropyl) benzene, n-butyl-4,4-bis (t-butylperoxy) butane, 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, t-butylperoxybenzate, benzoyl peroxide, etc. be able to. These compounds may be used alone or in combination of two or more.

The blending amount of the thermal polymerization initiator can be, for example, 0.1 to 2 parts by weight with respect to 100 parts by weight of the matrix resin.

As the photopolymerization initiator, a known photoinitiator that generates a free radical by ultraviolet light or visible light can be appropriately used. Examples of the photopolymerization initiator include benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, and benzoin phenyl ether, benzophenone, N, N′-tetramethyl-4,4′-diamino Benzophenones (Michler's ketone), benzophenones such as N, N′-tetraethyl-4,4′-diaminobenzophenone, benzyl ketals such as benzyldimethyl ketal (manufactured by Ciba Japan Chemicals, Irgacure 651), benzyl diethyl ketal, Acetophenones such as 2,2-dimethoxy-2-phenylacetophenone, p-tert-butyldichloroacetophenone, p-dimethylaminoacetophenone, 2,4-dimethylthio Xanthones such as xanthone and 2,4-diisopropylthioxanthone, or hydroxycyclohexyl phenyl ketone (Ciba Specialty Chemicals, Irgacure 184), 1- (4-isopropylphenyl) -2-vitoxy-2-methylpropane-1 -On (Ciba Japan Chemicals, Darocur 1116), 2-hydroxy-2-methyl-1-phenylpropan-1-one (Merck, Darocur 1173), and the like. These may be used singly or in combination of two or more.

Examples of the photopolymerization initiator include a combination of 2,4,5-triallylimidazole dimer and 2-mercaptobenzoxazole, leucocrystal violet, tris (4-diethylamino-2-methylphenyl) methane, and the like. Etc. Further, for example, known additives may be used as appropriate, such as tertiary amines such as triethanolamine for benzophenone.

The blending amount of the photopolymerization initiator is usually 0.1 to 5 parts by weight with respect to 100 parts by weight of the matrix resin, for example.

The organic compound additive (B) is preferably an organic compound having a melting point higher than the melting point of the ethylene copolymer (A). By using the production method of the present invention, in particular, an organic compound additive having a melting point higher than the molding temperature can be uniformly dispersed in the ethylene copolymer.

The organic compound additive (B) is preferably, for example, an ultraviolet absorber, an antioxidant, a light stabilizer, an anti-aging agent, or a solid crosslinking aid. These may be used singly or in combination of two or more.

As the organic compound additive (B), for example, the melting point is preferably 100 to 250 ° C., more preferably 150 to 200 ° C., and further preferably 160 to 180 ° C. The above melting point is measured by observing the temperature at which the crystalline state changes to the liquid state in the temperature raising process (10 ° C./min).

The content of the organic compound additive (B) is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the matrix resin. More preferably, it is 1 to 1 part by weight.

As the ultraviolet absorbing compound, known compounds can be appropriately used. Examples of the ultraviolet absorbing compound include benzophenone, benzotriazole, triazine, salicylic acid, and cyanoacrylate. These compounds may be used alone or in combination of two or more.

Examples of the benzophenone-based ultraviolet absorbing compound include 2,2′-dihydroxy-4,4′-di (hydroxymethyl) benzophenone and 2,2′-dihydroxy-4,4′-di (2-hydroxyethyl) benzophenone. 2,2′-dihydroxy-3,3′-dimethoxy-5,5′-di (hydroxymethyl) benzophenone, 2,2′-dihydroxy-3,3′-dimethoxy-5,5′-di (2- Hydroxyethyl) benzophenone, 2,2′-dihydroxy-3,3′-di (hydroxymethyl) -5,5′-dimethoxybenzophenone, 2,2′-dihydroxy-3,3′-di (2-hydroxyethyl) -5,5'-dimethoxybenzophenone, 2,2-dihydroxy-4,4-dimethoxybenzophenone, etc. .

Examples of the benzotriazole ultraviolet absorbing compound include 2- [2′-hydroxy-5 ′-(hydroxymethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(2-hydroxy). Ethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5 '-(3-hydroxypropyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-methyl-5' -(Hydroxymethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-methyl-5 '-(2-hydroxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy -3'-methyl-5 '-(3-hydroxypropyl) phenyl] -2H-benzotriazole, 2- [2'- Roxy-3'-t-butyl-5 '-(hydroxymethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-t-butyl-5'-(2-hydroxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-t-butyl-5 '-(2-hydroxyethyl) phenyl] -5-chloro-2H-benzotriazole, 2- [2'-hydroxy- 3′-t-butyl-5 ′-(3-hydroxypropyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-3′-t-octyl-5 ′-(hydroxymethyl) phenyl] -2H -Benzotriazole, 2- [2'-hydroxy-3'-t-octyl-5 '-(2-hydroxyethyl) phenyl] -2H-benzotriazole, 2- [2' Hydroxy-3′-t-octyl-5 ′-(3-hydroxypropyl) phenyl] -2H-benzotriazole or the like, or 2,2′-methylenebis [6- (2H-benzotriazoly-2-yl) -4- ( Hydroxymethyl) phenol], 2,2'-methylenebis [6- (2H-benzotriazoly-2-yl) -4- (2-hydroxyethyl) phenol], 2,2'-methylenebis [6- (5-chloro- 2H-benzotriazoly-2-yl) -4- (2-hydroxyethyl) phenol], 2,2'-methylenebis [6- (5-bromo-2H-benzotriazoly-2-yl) -4- (2-hydroxyethyl) ) Phenol], 2,2'-methylenebis [6- (2H-benzotriazoly-2-yl) -4- (3-hydroxypropyl) pheno 2,2′-methylenebis [6- (5-chloro-2H-benzotriazoly-2-yl) -4- (3-hydroxypropyl) phenol], 2,2′-methylenebis [6- (5- Bromo-2H-benzotriazoly-2-yl) -4- (3-hydroxypropyl) phenol], 2,2'-methylenebis [6- (2H-benzotriazoly-2-yl) -4- (4-hydroxybutyl) phenol ], 2,2'-methylenebis [6- (5-chloro-2H-benzotriazoly-2-yl) -4- (4-hydroxybutyl) phenol], 2,2'-methylenebis [6- (5-bromo- 2H-benzotriazoly-2-yl) -4- (4-hydroxybutyl) phenol], 3,3- {2,2′-bis [6- (2H-benzotriazoly-2-yl) 1-hydroxy-4- (2-hydroxyethyl) phenyl]} propane, 2,2- {2,2′-bis [6- (2H-benzotriazoly-2-yl) -1-hydroxy-4- (2- Hydroxyethyl) phenyl]} butane, 2,2′-oxybis [6- (2H-benzotriazoly-2-yl) -4- (2-hydroxyethyl) phenol], 2,2′-bis [6- (2H— Benzotriazoly-2-yl) -4- (2-hydroxyethyl) phenol] sulfide, 2,2′-bis [6- (2H-benzotriazoly-2-yl) -4- (2-hydroxyethyl) phenol] sulfoxide, 2,2′-bis [6- (2H-benzotriazoly-2-yl) -4- (2-hydroxyethyl) phenol] sulfone, 2,2′-bis [6- (2H-benzo Zotoriazori 2-yl), etc. -4- (2-hydroxyethyl) phenol] amine can be exemplified.

Examples of the triazine-based ultraviolet absorbing compound include 2- (2-hydroxy-4-hydroxymethylphenyl) -4,6-diphenyl-s-triazine and 2- (2-hydroxy-4-hydroxymethylphenyl) -4. , 6-bis (2,4-dimethylphenyl) -s-triazine, 2- [2-hydroxy-4- (2-hydroxyethyl) phenyl] -4,6-diphenyl-s-triazine, 2- [2- Hydroxy-4- (2-hydroxyethyl) phenyl] -4,6-bis (2,4-dimethylphenyl) -s-triazine, 2- [2-hydroxy-4- (2-hydroxyethoxy) phenyl] -4 , 6-Diphenyl-s-triazine, 2- [2-hydroxy-4- (2-hydroxyethoxy) phenyl] -4,6-bis (2,4-dimethyl) Phenyl) -s-triazine, 2- [2-hydroxy-4- (3-hydroxypropyl) phenyl] -4,6-diphenyl-s-triazine, 2- [2-hydroxy-4- (3-hydroxypropyl) Phenyl] -4,6-bis (2,4-dimethylphenyl) -s-triazine, 2- [2-hydroxy-4- (3-hydroxypropoxy) phenyl] -4,6-diphenyl-s-triazine, 2 -[2-hydroxy-4- (3-hydroxypropoxy) phenyl] -4,6-bis (2,4-dimethylphenyl) -s-triazine, 2- [2-hydroxy-4- (4-hydroxybutyl) Phenyl] -4,6-diphenyl-s-triazine, 2- [2-hydroxy-4- (4-hydroxybutyl) phenyl] -4,6-bis (2,4-dimethyl) Phenyl) -s-triazine, 2- [2-hydroxy-4- (4-hydroxybutoxy) phenyl] -4,6-diphenyl-s-triazine, 2- [2-hydroxy-4- (4-hydroxybutoxy) Phenyl] -4,6-bis (2,4-dimethylphenyl) -s-triazine, 2- (2-hydroxy-4-hydroxymethylphenyl) -4,6-bis (2-hydroxy-4-methylphenyl) -S-triazine, 2- [2-hydroxy-4- (2-hydroxyethyl) phenyl] -4,6-bis (2-hydroxy-4-methylphenyl) -s-triazine, 2- [2-hydroxy- 4- (2-hydroxyethoxy) phenyl] -4,6-bis (2-hydroxy-4-methylphenyl) -s-triazine, 2- [2-hydroxy-4- (3- Hydroxypropyl) phenyl] -4,6-bis (2-hydroxy-4-methylphenyl) -s-triazine, 2- [2-hydroxy-4- (3-hydroxypropoxy) phenyl] -4,6-bis ( 2-hydroxy-4-methylphenyl) -s-triazine, 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) phenol 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol and the like.

Examples of the salicylic acid-based ultraviolet absorbing compound include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.

Examples of the cyanoacrylate-based ultraviolet absorbing compound include 2-ethylhexyl-2-cyano-3,3′-diphenyl acrylate, ethyl-2-cyano-3,3′-diphenyl acrylate, and the like.

Further, when a compound having a wavelength conversion function is used as the ultraviolet absorbing compound, examples of the ultraviolet absorbing compound include fluorescent compounds that absorb light in a wavelength region of 350 to 400 nm more than light in a wavelength region exceeding 400 nm. be able to. Examples of the fluorescent compound include organic fluorescent compounds and inorganic fluorescent compounds.

As the organic fluorescent compound, known organic pigment compounds (such as organic fluorescent dyes) can be used. Examples of the organic fluorescent compound include naphthalimide, perylene, anthraquinone, coumarin, benzocoumarin, xanthene, phenoxazine, benzo [a] phenoxazine, benzo [b] phenoxazine, benzo [c] phenoxazine, and naphthalimide. , Naphtholactam, azlactone, methine, oxazine, thiazine, diketopyrrolopyrrole, quinacridone, benzoxanthene, thioepiindrin, lactamimide, diphenylmaleimide, acetoacetamide, imidazothiazine, benzanthrone, perylenemonoimide, phthalimide, benzotriazole Benzothiadiazole, benzoxazole, pyrimidine, pyrazine, triazole, dibenzofuran, triazine, harbituric acid derivatives, etc. It can be. These compounds may be used alone or in combination of two or more.

Examples of the inorganic fluorescent compound include complex compounds having europium or samarium as the emission center. These compounds may be used alone or in combination of two or more.

The absorbance of the fluorescent compound is, for example, preferably from 0.1 to 6, more preferably from 0.5 to 4, and further preferably from 0.8 to 3.

The ultraviolet absorbing compound preferably has a maximum absorption wavelength in the range of 200 to 400 nm, particularly 280 to 380 nm. By using the ultraviolet absorbing compound, it is possible to more effectively absorb ultraviolet rays that may cause photodegradation of an ethylene copolymer such as an ethylene-vinyl acetate copolymer, among ultraviolet rays contained in irradiation light. In addition, the maximum absorption wavelength of the said ultraviolet absorption compound can be measured using a commercially available ultraviolet ray measuring apparatus etc. using a well-known method.

Of the above ultraviolet absorbing compounds, it is preferable to use a benzophenone ultraviolet absorbing compound from the viewpoint of preventing photodegradation of the ethylene-vinyl acetate copolymer, and the benzophenone ultraviolet absorbing containing two or less hydroxyl groups in one molecule. It is particularly preferred to use a compound. Examples of the ultraviolet absorbing compound include 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-n-octoxy-benzophenone. The above compound has a maximum absorption wavelength in the range of 320 to 350 nm, and can more effectively suppress the photodegradation of the ethylene-based copolymer (A) such as an ethylene-vinyl acetate copolymer.

As the antioxidant, known ones can be used as appropriate. Examples of the photo-antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, amine-based antioxidants, lactone-based antioxidants, vitamin E-based antioxidants, and the like. it can. These compounds may be used alone or in combination of two or more.

Among the above antioxidants, since the effect of suppressing coloring is large, 2,6-di-t-butyl-4-methylphenol, which is a phenolic antioxidant, pentaerythritol tetrakis (3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate) and the like are preferred.

As the light stabilizer, known ones can be used as appropriate. Examples of the light stabilizer include compounds having a function of capturing radical species harmful to the polymer and preventing generation of new radicals. Examples of the light stabilizer include hindered amine light stabilizers. These compounds may be used alone or in combination of two or more. By including the light stabilizer, it is possible to suppress degradation of the matrix resin due to the influence of irradiated light and the like, and yellowing of the solar cell sealing film.

Examples of the low molecular weight hindered amine light stabilizer include, for example, decanedioic acid bis (2,2,6,6-tetramethyl-1 (octyloxy) -4-piperidinyl) ester, 1,1-dimethylethyl hydroper 70% by weight of a reaction product of oxide and octane (molecular weight 737) and 30% by weight of polypropylene; bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1 , 1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate (molecular weight 685); bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2, 6,6-pentamethyl-4-piperidyl sebacate mixture (molecular weight 509); bis (2,2,6,6-tetramethyl-4-piperi ) Sebacate (molecular weight 481); tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate (molecular weight 791); tetrakis (1,2,2) , 6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate (molecular weight 847); 2,2,6,6-tetramethyl-4-piperidyl-1,2,3 Mixture of 4-butanetetracarboxylate and tridecyl-1,2,3,4-butanetetracarboxylate (molecular weight 900); 1,2,2,6,6-pentamethyl-4-piperidyl-1,2,3 Examples thereof include a mixture of 4-butanetetracarboxylate and tridecyl-1,2,3,4-butanetetracarboxylate (molecular weight: 900).

As the hindered amine light stabilizer having a high molecular weight, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2, 2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (molecular weight 2,000-3,100); succinic acid Polymer of dimethyl and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (molecular weight 3,100 to 4,000); N, N ′, N ″, N ″ ′-tetrakis- ( 4,6-bis- (butyl- (N-methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10- Diamine (Molecular weight 2,286) A mixture of the above dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol; dibutylamine, 1,3,5-triazine, N, N′-bis (2, Polycondensate of 2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine (molecular weight 2,600- 3,400).

Examples of commercially available hindered amine light stabilizers include LA-52, LA-57, LA-62, LA-63LA-63p, LA-67, LA-68 (all manufactured by ADEKA), Tinuvin 744, Tinuvin 770, Tinuvin 765, Tinuvin 123, Tinuvin 144, Tinuvin 622LD, CHIMASORB 944LD (all manufactured by BASF), UV-3034 (manufactured by BF Goodrich), and the like can be mentioned.

As the crosslinking aid, known ones can be used as appropriate. Examples of the crosslinking aid include compounds having a radical polymerizable group as a functional group. Examples of the crosslinking aid include trifunctional crosslinking aids such as triallyl cyanurate and triallyl isocyanurate, and monofunctional or bifunctional crosslinking aids such as (meth) acrylic esters (NK esters, etc.). it can. These may be used singly or in combination of two or more. By using the said crosslinking adjuvant, the gel fraction of matrix resin can be improved more reliably and the adhesiveness and durability of a sealing material layer can be improved. The crosslinking aid is more preferably used as the liquid additive, but a solid crosslinking aid may be used alone or in combination with a liquid crosslinking aid.

As the anti-aging agent, known ones can be used as appropriate. Examples of the antioxidant include hindered phenol antioxidants such as N, N′-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamide]. , Phosphorus heat stabilizers, lactone heat stabilizers, vitamin E heat stabilizers, sulfur heat stabilizers, and the like. These compounds may be used alone or in combination of two or more.

In the solar cell encapsulant composition, the components (compounds) are mixed and dispersed in the matrix resin. The solar cell encapsulant composition may contain a known additive as long as the desired performance is not impaired. Examples of the additive include a thermoplastic polymer, a filler, a plasticizer, a silane coupling agent, an acid acceptor, and clay. These may be used singly or in combination of two or more. Moreover, as long as it is an organic compound among these other additives, you may use as said organic compound additive (B).

In the blending step, an organic peroxide (C) is further included, and the melting point of the organic compound additive (B) is 10 ° C. or more lower than the one-hour half-life temperature of the organic peroxide (C). It is preferable that

As the organic peroxide (C), the thermal polymerization initiator can be appropriately used. Among the above polymerization initiators, the one-hour half-life temperature (temperature at which the half-life is one hour) is preferably 90 to 180 ° C, more preferably 100 to 160 ° C, and more preferably 110 to 140 ° C. More preferably. Examples of the polymerization initiator include tertiary butyl peroxyisopropyl carbonate, tertiary butyl peroxyacetate, tertiary butyl peroxybenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-bis (tertiary butyl Peroxy) hexane, di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexyne-3, 1,1-bis (tert-butylperoxy) -3,3 , 5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, methyl ethyl ketone peroxide, 2,5-dimethylhexyl-2,5-bisperoxybenzoate, tert-butyl hydroperoxide, p-menthane Hydroperoxide, benzoyl peroxide, p-chlorobenzoy Peroxide, tert-butylperoxy isobutyrate, hydroxyheptyl peroxide, and the like di cyclohexanone peroxide. These may be used singly or in combination of two or more.

The melting point of the organic compound additive (B) is preferably at least 10 ° C lower than the one-hour half-life temperature of the organic peroxide (C), and may be at least 20 ° C lower than the temperature. The temperature may be 30 ° C. or lower, or 40 ° C. or lower. By using the production method of the present invention, even if the organic compound additive (B) has a melting point of about 1 hour half-life or higher, which is usually difficult, the organic peroxide (C) It is possible to uniformly disperse the organic compound additive having a melting point higher than the molding temperature in the ethylene-based copolymer without substantially decomposing the oxide.

(Method for producing solar cell encapsulant layer)
The manufacturing method of the sealing material composition for solar cells of this invention is a manufacturing method of the sealing material composition for solar cells containing an ethylene-type copolymer (A) and an organic compound additive (B),
The ethylene copolymer (A) and the organic polymer are within a temperature range from the Vicat softening point of the ethylene copolymer (A) to 10 ° C. below the melting point of the ethylene copolymer (A). A blending step of mixing the compound additive (B) is included.

The Vicat Softening Temperature (VST) of the ethylene copolymer (A) is JIS K7206 (test load is method A (10N), heating rate of heat transfer medium is 50 ° C / hour) Means the value measured by The temperature at the time when the end surface having a cross-sectional area of 1 mm ² bites in by 1 mm is defined as the Vicat softening point temperature.

The blending step is carried out within a temperature range from the Vicat softening point of the ethylene copolymer (A) to 10 ° C lower than the melting point of the ethylene copolymer (A). A) and the organic compound additive (B) are mixed.

For example, when the Vicat softening point of the ethylene copolymer (A) is X ° C. and the melting point of the ethylene copolymer (A) is Y ° C., the temperature range in which the blending process is performed is X ° C. Above (Y-10) ° C.

As a lower limit of the temperature range, a temperature 3 ° C. higher than the Vicat softening point of the ethylene copolymer (A), 5 ° C. higher temperature, 10 ° C. higher temperature, 15 ° C. higher temperature, 20 ° C. higher temperature, etc. it can.

The upper limit of the temperature range may be a temperature lower by 13 ° C., a temperature lower by 15 ° C., a temperature lower by 20 ° C., a temperature lower by 25 ° C., etc.

The mixing time of the blending step can be, for example, 1 minute to 60 minutes, 3 minutes to 40 minutes, 5 minutes to 30 minutes, 10 minutes to 15 minutes. be able to.

In the blending step, each material (compound) can be mixed (stirred and mixed) using a known method as appropriate. For example, a method of adding the organic compound additive (B) to the ethylene copolymer (A), a method of adding the ethylene copolymer (A) to the organic compound additive (B), Examples include a method of simultaneously or sequentially charging in a kneading apparatus and mixing in the apparatus, a method of simultaneously or sequentially charging the ethylene copolymer (A), the organic compound additive (B), and the liquid additive. be able to. In particular, when the ethylene copolymer (A) is in the form of pellets, it is preferable to use a method in which the organic compound additive (B) is mixed and stirred to adhere to the pellet surface. Furthermore, when the ethylene-based copolymer (A) is in the form of pellets and a liquid additive is used, it is preferable to use a method in which the liquid additive is mixed and stirred and impregnated inside the pellet. Moreover, the said blending process has the preferable method (it performs by a dry process) which does not use a solvent separately except the structural component of solar cell sealing material compositions, such as a liquid additive.

In the above production method, the ethylene copolymer (A) is preferably in the form of pellets.

In addition, the pellet form refers to, for example, a particle having a diameter or length of about 1 to 10 mm, for example, 2 to 7 mm, or 3 to 5 mm. Further, examples of the pellet shape include particles in the form of a substantially columnar shape, a substantially spherical shape, a substantially disc shape, a substantially triangular prism shape, a substantially quadrangular prism shape, a substantially polyhedral shape, an elliptical sphere, and the like.

In the blending step, it is preferable to control the temperature of the blended mixture (matrix resin or the like) using, for example, a jacket or a cooler.

Preferred examples of the equipment used in the blending process include a single screw extruder, a twin screw extruder, a Banbury mixer, a kneader, and a mixing roll.

In the above production method, it is preferable that a melt kneading step is included after the blending step.

As the melt-kneading step, a known method can be used as appropriate. The melt kneading step can be performed by, for example, heat kneading, a roll mill, a plast mill, a melt extruder, a Banbury mixer, a kneader, or the like. Moreover, you may shape | mold directly as a sealing material layer for solar cells through the said melt-kneading process.

The mixing temperature in the melt-kneading step can be, for example, 40 to 150 ° C., 80 to 140 ° C., 90 to 120 ° C., or 100 to 110 ° C. . In order to prevent gelation due to peroxide, it is preferably performed at 110 ° C. or lower.

The mixing time in the melt kneading step can be, for example, 1 to 20 minutes, 3 to 10 minutes, 3 to 7 minutes, 3 to 5 minutes. It can be carried out.

(Sealant layer for solar cells)
On the other hand, the solar cell encapsulant layer of the present invention is formed using the solar cell encapsulant composition obtained by the above-described production method.

In order to produce the solar cell encapsulant layer, a known method can be used as appropriate. For example, a composition obtained by heating and mixing the above-described solar cell encapsulant composition (or each material thereof) with a known method using heat kneading, a roll mill, a plast mill, etc., is subjected to ordinary extrusion molding, calendar molding (calendering). ), And can be appropriately produced by a method of forming a sheet-like material by vacuum hot pressing or the like. Moreover, after forming the said layer on PET film etc., it can manufacture by the method of transcribe | transferring to a surface protective layer. Further, a method of simultaneously kneading and melting and applying with a hot melt applicator can be used. In particular, in the present invention, a method is preferred in which the blending step and the melt-kneading step are performed in a kneading apparatus such as a melt extruder, and the molding is continuously performed as a sealing material layer such as a sheet or film.

More specifically, for example, the solar cell encapsulant composition obtained by the production method may be applied and formed as it is on a surface protective layer or a separator, or the material may be mixed with other materials. You may apply | coat and form as a composition.

When applying the solar cell encapsulant composition, for example, if the melting point of the matrix resin of the solar cell encapsulant composition is 50 to 120 ° C., the kneading and melting and application temperature of the composition are: It is preferable to carry out at a temperature obtained by adding 30 to 100 ° C. to the above melting point.

In particular, in the present invention, a method is preferred in which the blending step and the melt-kneading step are performed in a kneading apparatus such as a melt extruder, and the molding is continuously performed as a sheet-like or film-like sealing material layer. Alternatively, in some embodiments, a solar cell encapsulant layer is produced into a thin film structure by the following steps: (i) polymer (matrix resin) powder is a solvent (eg, A step of preparing a polymer solution dissolved in tetrachloroethylene (TCE), cyclopentanone, dioxane, etc.), (ii) a luminescent dye (fluorescent compound) containing the polymer mixture, and the polymer solution with a luminescent dye at a predetermined weight ratio Mixing to obtain a dye-containing polymer solution, (iii) pouring the dye / polymer thin film directly onto the glass substrate, after which the substrate is allowed to warm up from room temperature in 2 hours Formed by heat treatment to 100 ° C and complete removal of residual solvent by further vacuum heating overnight at 130 ° C And (iv) peeling the dye / polymer thin film in water before use and then completely drying the free-standing polymer film; (v) the thickness of the film, the concentration of the dye / polymer solution And can be controlled by changing the evaporation rate.

The thickness of the solar cell encapsulant layer is preferably 20 to 2000 μm, more preferably 50 to 1000 μm, and even more preferably 100 to 800 μm. When the thickness is less than 20 μm, the sealing material function is hardly exhibited. On the other hand, when it becomes thicker than 2000 micrometers, the thickness of a solar cell module will become large and it will be disadvantageous also in cost.

The solar cell encapsulant layer is usually used for encapsulating solar cells, but is laminated so as to appropriately seal interconnector materials, electrodes, and the like as necessary. As long as the function of the solar cell encapsulant layer is not impaired, other layers such as each layer may be interposed as required.

(Solar cell module)
The solar cell module 1 of the present invention includes a surface protective layer 10, the solar cell sealing material layer 20, and solar cells 30. 1 and 2 show simple schematic diagrams as an example, but the present invention is not limited to these. Moreover, the sealing material layer 40 and the back sheet | seat 50 can also be further suitably provided in the back side of a photovoltaic cell. Moreover, as long as the said function of the said solar cell sealing material layer is not impaired between these each layers, you may interpose other layers, such as an adhesive material layer and an adhesive layer, suitably. Moreover, you may use the sealing material layer for solar cells of this invention suitably as said sealing material layer for back surfaces.

As the solar cell, for example, a cadmium sulfide / cadmium telluride solar cell, a copper indium gallium diselenide solar cell, an amorphous silicon solar cell, a microcrystalline silicon solar cell, or a crystalline silicon solar cell can be used. The solar battery cell is preferably a crystalline silicon solar battery.

In the production of the solar cell module, the solar cell encapsulant layer may be transferred to the solar cell or the like, or may be directly coated on the solar cell. Moreover, you may form the said sealing material layer for solar cells, and another layer simultaneously.

Hereinafter, examples and the like specifically showing the configuration and effects of the present invention will be described.

(Compounds in the table)
In the examples and comparative examples, the following compounds were used.
[Ethylene copolymer (A)]
・ Smitate KA30: matrix resin, ethylene vinyl acetate resin (EVA) (manufactured by Sumitomo Chemical Co., Ltd., melting point 74 ° C., Vicat softening point 39 ° C.)
Ultrasen 710: Matrix resin, ethylene vinyl acetate resin (EVA) (manufactured by Tosoh Corporation, melting point 71 ° C., Vicat softening point 40 ° C.)
・ Smitate MA10: Matrix resin, ethylene vinyl acetate resin (EVA) (manufactured by Sumitomo Chemical Co., Ltd., melting point 57 ° C., Vicat softening point 33 ° C.)
[Organic compound additive (B)]
Compound B1: 4,7-bis (4-methoxyphenyl) -2,1,3-benzothiadiazole (melting point: 201 ° C.)
Compound B2: 4,7-bis (4-isobutyloxyphenyl) -2-isobutyl-2H-benzotriazole (melting point: 167 ° C.)
Tinuvin 900: 2- (2H-benzothiadiazol-2-yl) -4,6- (1-methyl-1-phenylethyl) phenol (BASF, melting point 138 ° C.)
[Organic peroxide (C)]
Perbutyl E: t-butylperoxy-2-ethylhexyl monocarbonate (manufactured by NOF Corporation, one hour half-life temperature 119 ° C.)
[Silane coupling agent]
KBM503: 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone)
[Crosslinking aid]
-TAIC: Crosslinking aid, triallyl isocyanurate (manufactured by Nippon Kasei Co., Ltd.)

(Production of resin sheet)
In Examples and Comparative Examples, each sealing material layer (sealing material sheet) was produced by the following method based on the compounds shown in Table 1.

In each Example / Comparative Example, each material (compound) was mixed and stirred using a small pulverizer (manufactured by ASONE Co., Ltd.) while controlling the temperature in the system with a cooler so that each temperature range was reached Pre-blending (5 minutes) was performed. Thereafter, the pre-blended resin composition was put into a Laboplast Mill 4C150 type (roller shape: Sigma type, manufactured by Toyo Seiki Co., Ltd.) and kneaded at 80 ° C. and 10 rpm for 5 minutes. The obtained kneaded product was pressed at 100 ° C. and 20 kN for 5 minutes using a vacuum heat press VS20-3430 (manufactured by Mikado Technos) to form a 400 μm-thick sealing material sheet.

(Evaluation of resin after pre-blending)
The appearance of the naked eye was evaluated on the resin composition after pre-blending. The evaluation criteria were as follows.
・ When there was no blocking, or when no liquid component remained on the surface: ○
・ When blocking between resins occurs, or when liquid components remain on the resin surface: ×

(Evaluation of sheet dispersibility)
First, the appearance shape with the naked eye was evaluated with respect to the obtained sealing material sheet, and when the said organic compound additive (B) remained, it was set as the rejection. On the other hand, the following evaluation was continued for those in which the remaining of the above compound could not be discerned with the naked eye.

The molded encapsulant sheet was cut out at 2 cm square, and the absorbance of the organic compound additive was measured with MCPD-9800 (manufactured by Otsuka Electronics Co., Ltd.). The absorbance / thickness was determined as the standard deviation of n = 5, and the dispersibility was evaluated. Carried out. The evaluation criteria were as follows.
・ When the standard deviation is less than 0.1: ○
・ When the standard deviation is 0.1 or more: ×

Tables 1 and 2 below show the respective measurement results when each compounding (part by weight) and the obtained sealing material layer resin sheet were used.

As a result of measurement / evaluation, the evaluation of the resin after pre-blending and the evaluation of the sheet dispersibility were both good in any of the examples. On the other hand, in Comparative Example 1, the dispersibility was poor. Moreover, in the comparative example 2, the dispersibility was bad and the liquid component remained on the resin surface. Further, in Comparative Examples 3 to 5, the temperature at the time of pre-blending was higher than that of the present invention and blocked.

DESCRIPTION OF SYMBOLS 1 Solar cell module 10 Surface protective layer 20 Solar cell sealing material layer 30 Solar cell 40 Back surface sealing material layer 50 Back sheet

Claims

A method for producing a solar cell encapsulant composition comprising an ethylene copolymer (A) and an organic compound additive (B),
The ethylene copolymer (A) and the organic polymer are within a temperature range from the Vicat softening point of the ethylene copolymer (A) to 10 ° C. below the melting point of the ethylene copolymer (A). The manufacturing method of the sealing material composition for solar cells characterized by including the blending process which mixes a compound additive (B).
The manufacturing method of the sealing material composition for solar cells of Claim 1 whose said ethylene-type copolymer (A) is a pellet form.
In the blending step, an organic peroxide (C) is further included, and the melting point of the organic compound additive (B) is 10 ° C. or more lower than the one-hour half-life temperature of the organic peroxide (C). The manufacturing method of the sealing material composition for solar cells of Claim 1 or 2 which is.
The method for producing a solar cell encapsulant composition according to any one of claims 1 to 3, wherein no solvent is used in the blending step.
The method for producing a solar cell encapsulant composition according to any one of claims 1 to 4, further comprising a liquid additive in the blending step.
The method for producing a sealing material composition for a solar cell according to any one of claims 1 to 5, further comprising a melt-kneading step subsequent to the blending step.
The method for producing a solar cell encapsulant composition according to any one of claims 1 to 6, wherein the melt-kneading step is performed by a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll.
The sealing for solar cell according to any one of claims 1 to 7, wherein the organic compound additive (B) is an ultraviolet absorber, an antioxidant, a light stabilizer, an anti-aging agent, or a crosslinking aid. Manufacturing method of material composition.
The method for producing a solar cell encapsulant composition according to any one of claims 1 to 8, wherein the ethylene copolymer (A) comprises an ethylene-vinyl acetate copolymer as a main component.
A solar cell encapsulant composition obtained by the production method according to any one of claims 1 to 9.
A solar cell encapsulant layer formed using the solar cell encapsulant composition according to any one of claims 1 to 9.
A solar cell module comprising a solar cell encapsulant layer formed using the solar cell encapsulant composition according to any one of claims 1 to 9.
The solar cell is a crystalline silicon solar cell, a cadmium sulfide / cadmium telluride solar cell, a copper indium gallium diselenide solar cell, an amorphous silicon solar cell, or a microcrystalline silicon solar cell. Solar cell module.