JP3978911B2 - Solar cell cover material, sealing film, and solar cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cover material used as a transparent protective member of a cell for solar cells, a sealing film using the cover material, and a solar cell, and more particularly a transparent film having both moisture resistance and light resistance. Solar cell cover material and solar cell cover material sealing film effective for weight reduction, impact resistance and durability improvement, and this solar cell cover material are used as a front and / or back side transparent protective member The present invention relates to a lightweight, high impact resistance, high durability solar cell.
[0002]
[Prior art]
In recent years, solar cells that directly convert sunlight into electric energy have attracted attention and are being developed from the viewpoint of effective use of resources and prevention of environmental pollution.
[0003]
As shown in FIG. 6, a solar cell generally has an ethylene-vinyl acetate copolymer (EVA) between a glass substrate 11 as a surface-side transparent protective member on the light-receiving surface side and a back-side protective member (back cover) 12. It is set as the structure which sealed the cells for solar cells, ie, the electric power generating elements 14, such as a silicon | silicone, with the sealing film of film 13A, 13B.
[0004]
In such a solar cell, the glass substrate 11, the sealing film EVA film 13A, the silicon power generation element 14, the sealing film EVA film 13B, and the back cover 12 are laminated in this order, and the EVA is heated and melted to be crosslinked and cured. It is manufactured by bonding and integrating.
[0005]
By the way, as a surface-side transparent protective member of a solar cell, first of all, it is required to be excellent in durability against ultraviolet rays. In addition, it prevents rusting of internal conductors and electrodes due to moisture or water permeation. Therefore, it is an extremely important requirement to have excellent moisture resistance. For this reason, conventionally, a glass plate is used as the surface-side transparent protective member.
[0006]
[Problems to be solved by the invention]
However, the glass plate is excellent in light resistance and moisture resistance, but has a drawback that it is heavy and weak against impact and easily cracked.
[0007]
If it is a transparent resin film, it is light and there is no problem of damage due to impact, but at present, no resin film having both good light resistance and moisture resistance has been provided. That is, for example, a fluororesin film such as 2-ethylene-4-fluorinated ethylene copolymer (ETFE) is known as a transparent resin film excellent in light resistance. It cannot be applied as a surface side transparent protective member.
[0008]
The present invention solves the above-mentioned conventional problems, and is a cover material used as a transparent protective member for a solar cell, comprising a transparent film having both moisture resistance and light resistance. The solar cell cover material and the solar cell cover material sealing film effective for improving the durability and durability, and the solar cell cover material as a transparent protective member for the front side and / or the back side are used. An object is to provide an impact-resistant and highly durable solar cell.
[0009]
[Means for Solving the Problems]
The solar cell cover material of the present invention is a cover material used as a transparent protective member of a solar cell, and is formed by laminating a transparent high light-resistant film and a transparent high moisture-proof film with an adhesive containing an ultraviolet absorber. turned into and Ri Na, the transparent high moisture barrier film, two sheets of inorganic oxide coated transparent film made of a laminate film obtained by bonding the coating surfaces are, the transparent high light film is a fluororesin film Or a film formed of a resin composition in which an ultraviolet absorber is kneaded into one or two or more kinds of resins made of acrylic, polycarbonate, polyethylene terephthalate and polyethylene naphthalate, and an adhesive containing the ultraviolet absorber. this the agent by blending an epoxy, acrylic, urethane or ester-based adhesive resin to ultraviolet absorber The features.
[0010]
If it is the cover material for solar cells of this invention, the moisture-proof property requested | required of the transparent protection member of a solar cell will be ensured by a transparent high moisture-proof film, and light resistance will be ensured by the transparent high light-resistant film and the ultraviolet absorber in an adhesive agent. can do.
[0011]
In the present invention, the transparent high-moisture barrier films, polyethylene terephthalate (PET) film, laminated film two coated transparent fill beam silica or inorganic oxides such as alumina made by bonding coating faces is suitable is there.
[0012]
Moreover, as a transparent high light resistance film, polytetrafluoroethylene (PTFE), 4-fluorinated ethylene-perchloroalkoxy copolymer (PFA), 4-fluorinated ethylene-6-fluorinated propylene copolymer (FEP) , Fluororesin films such as 2-ethylene-4-fluoroethylene copolymer (ETFE), poly-3-fluoroethylene chloride (PCTFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF), or acrylic A resin composition obtained by kneading a UV absorber in a resin such as polycarbonate, PET, or polyethylene naphthalate (PEN) is preferable.
[0013]
The solar cell cover material sealing film of the present invention is a sealing film that also functions as a transparent protective member for solar cell cells, and is formed by laminating and integrating the solar cell cover material of the present invention and an EVA film. It will be.
[0014]
The solar cell of the present invention is a solar cell in which a solar cell is sealed between a front surface side protective member and a back surface side protective member, and the solar cell of the present invention as a front surface side and / or back surface side protective member. Cover material is used.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
In the following, the case of using the solar cell cover material of the present invention as a surface side transparent protective member is exemplified, but the solar cell cover material of the present invention may be used as a back surface side transparent protective member, Moreover, you may use as both a protection member of the surface side and a back surface side.
[0017]
FIG. 1 is a cross-sectional view showing an embodiment of a cover material for a solar cell of the present invention, FIGS. 2 and 3 are cross-sectional views showing an embodiment of a transparent high moisture-proof film according to the present invention, and FIG. 4 is a solar cell of the present invention. FIG. 5 is a sectional view showing an embodiment of the solar cell of the present invention.
[0018]
A cover material 1 for a solar cell shown in FIG. 1 is an adhesive sheet (hereinafter referred to as “ultraviolet absorbing adhesive sheet”) 4 in which a transparent high moisture-proof film 2 and a transparent high light resistant film 3 are blended with an ultraviolet absorber. Are laminated and bonded and integrated.
[0019]
As shown in FIG. 2, the transparent high moisture-proof film 2 is a coating film of an inorganic oxide such as silica or alumina on a transparent substrate film 2A such as a PET film by CVD (chemical vapor deposition), PVD (reactive vapor deposition) or the like. there is formed a more made moisture-proof film 2B. That is, as a moisture-proof film, a film in which a coating film of a metal such as aluminum is formed on a base film is known. However, when a metal such as aluminum is applied to a solar cell, current may leak. The moisture-proof film is preferably an inorganic oxide coating film.
[0020]
By the way, as shown in FIG. 2, the moisture-proof film 2B made of an inorganic oxide such as silica or alumina formed on the surface of the base film 2A is easily peeled off during handling. For this reason, as the transparent high moisture-proof film 2, as shown in FIG. 3, two films in which a moisture-proof film 2B made of an inorganic oxide such as silica or alumina is formed on the surface of the base film 2A such as the PET film described above. using these moisture-proof film 2B, by attaching an adhesive sheet 2C to the 2B side inward, Ru used as the moisture-proof film 2B is not exposed to the surface. As this adhesive sheet 2C, the same UV absorbing adhesive sheet 4 used for bonding a transparent high moisture-proof film 2 and a transparent high light-resistant film 3 described later can be used (however, no UV absorber is blended). However, it is desirable that it is blended.
[0021]
In the case of a laminated high moisture-proof film as shown in FIG. 3, a PET film having a thickness of 6 to 250 μm is suitable as the base film 2A, and the moisture-proof film 2B is formed to a thickness of about 5 μm or less. It is preferable to do this. The thickness of the adhesive sheet 2C is preferably about 5 to 50 μm.
[0022]
Examples of the transparent high light-resistant film 3 include a fluororesin film excellent in ultraviolet resistance or a resin film kneaded with an ultraviolet absorber.
[0023]
Among these, examples of the fluororesin film include PTFE, PFA, FEP, ETFE, PCTFE, PVDF, and PVF film.
[0024]
Examples of the resin film kneaded with an ultraviolet absorber include acrylic, polycarbonate, PET, and PEN films. Examples of the ultraviolet absorber include 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-methoxy- Benzophenone series such as 5-sulfobenzophenone; benzotriazole series such as 2- (2′-hydroxy-5-methylphenyl) benzotriazole; hindered amines such as phenyl salsylate and pt-butylphenyl salsylate An ultraviolet ray absorbing material is used, and in a normal case, about 1 to 20% by weight is blended with respect to the base resin.
[0025]
The thickness of such a transparent high light-resistant film 3 is preferably about 6 to 200 μm.
[0026]
Examples of the ultraviolet absorber adhesive sheet 4, epoxy, acrylic, urethane, Ru used one formed by blending the adhesive resin ester ultraviolet absorber. Here, as the ultraviolet absorber, benzophenone series such as 2-hydroxy-4-octoxybenzophenone and 2-hydroxy-methoxy-5-sulfobenzophenone; 2- (2′-hydroxy-5-methylphenyl) benzotriazole Benzotriazoles such as hindered amine UV absorbers such as phenyl salsylate and pt-butylphenyl salsylate, etc., usually about 1 to 50% by weight based on the base resin Is done. The thickness of the ultraviolet absorbing adhesive sheet 4 is preferably about 5 to 50 μm.
[0027]
The cover material 1 for solar cells of the present invention has a UV absorbing adhesive sheet 4 interposed between the transparent high moisture-proof film 2 and the transparent high light resistant film 3 described above, and is heated under the bonding conditions of the UV absorbing adhesive sheet 4. It can be manufactured easily by bonding and integrating by pressing.
[0028]
In addition, as for the cover material of this invention, it is preferable that the transparent highly light-resistant film 3 is arrange | positioned at the surface side, and the transparent highly moisture-proof film 2 is arrange | positioned at the inner surface side.
[0029]
In order to manufacture the solar cell of the present invention using such a cover material for solar cells, sealing may be performed using the cover material of the present invention instead of the glass plate of the conventional solar cell shown in FIG. However, in that case, it is preferable that the cover material of the present invention is laminated and integrated with the sealing EVA film in advance.
[0030]
As shown in FIG. 4, the solar cell cover material sealing film 5 of the present invention is formed by bonding the transparent high moisture-proof film 2 and the transparent high light-resistant film 3 with an adhesive containing an ultraviolet absorber. The cover material 1 and the EVA film 6 are laminated and integrated.
[0031]
This solar cell cover material / sealing film 5 is laminated and integrated with the solar cell cover material 1 of the present invention in which the transparent high moisture-proof film 2 and the transparent high light-resistant film 3 are bonded in advance when the EVA film 6 is manufactured. Can be easily manufactured. The lamination temperature in this case is suitably about 75 to 90 ° C.
[0032]
In addition, it is preferable that the thickness of this EVA film 6 is about 0.1-1 mm.
[0033]
As shown in FIG. 5, the solar cell 10 of the present invention uses a solar cell cover material / sealing film 5, and a solar cell such as a back cover 7, an EVA film 8, a silicon power generation element 9, and a solar cell. The laminated body of the cover material and sealing film 5 is heated by a vacuum laminator at a temperature of 120 to 150 ° C., a degassing time of 2 to 15 minutes, a pressing pressure of 0.5 to 1 atm, and a pressing time of 8 to 45 minutes according to a conventional method. It can be easily manufactured by pressure bonding.
[0034]
In addition, the EVA resin composition suitable as a film-forming raw material of the EVA film used for the solar cell of this invention is demonstrated below.
[0035]
In order to improve weather resistance, the EVA resin composition according to the present invention is blended with a crosslinking agent to give a crosslinked structure, and as this crosslinking agent, generally, an organic peroxidation that generates radicals at 100 ° C. or higher. In particular, if the stability at the time of blending is taken into consideration, it is preferable that the decomposition temperature with a half-life of 10 hours is 70 ° C. or higher. Examples of such an organic peroxide include 2,5-dimethylhexane; 2,5-dihydroperoxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; -T-butyl peroxide; t-dicumyl peroxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne; dicumyl peroxide; α, α'-bis (t-butylperoxide Oxyisopropyl) 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-butylperoxybenzoate; benzoyl peroxide, etc. Kill. The compounding amount of these organic peroxides is generally 5 parts by weight or less, preferably 1 to 3 parts by weight with respect to 100 parts by weight of the EVA resin.
[0036]
Moreover, a silane coupling agent can be added to EVA resin as a sealing film of a solar cell for the purpose of improving the adhesive force with a power generating element. Known silane coupling agents for this purpose are, for example, γ-chloropropyltrimethoxysilane; vinyltrichlorosilane; vinyltriethoxysilane; vinyl-tris- (β-methoxyethoxy) silane; γ-methacryloxy. Propyltrimethoxysilane; β- (3,4-ethoxycyclohexyl) ethyltrimethoxysilane; γ-glycidoxypropyltrimethoxysilane; vinyltriacetoxysilane; γ-mercaptopropyltrimethoxysilane; γ-aminopropyltrimethoxysilane N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and the like can be mentioned. The amount of these silane coupling agents is generally 5 parts by weight or less, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the EVA resin.
[0037]
Furthermore, a crosslinking aid can be added to the EVA resin in order to improve the gel fraction of the EVA resin and improve the durability. Examples of crosslinking aids provided for this purpose include trifunctional crosslinking aids such as triallyl isocyanurate; triallyl isocyanate as well as monofunctional crosslinking aids such as NK esters. it can. The amount of these crosslinking aids is generally 10 parts by weight or less, preferably 1 to 5 parts by weight with respect to 100 parts by weight of the EVA resin.
[0038]
Furthermore, hydroquinone; hydroquinone monomethyl ether; p-benzoquinone; methyl hydroquinone, etc. can be added for the purpose of improving the stability of the EVA resin, and the blending amount thereof is generally 5 parts by weight with respect to 100 parts by weight of the EVA resin. It is as follows.
[0039]
Furthermore, if necessary, a colorant, an ultraviolet absorber, an anti-aging agent, a discoloration preventing agent and the like can be added in addition to the above. Examples of the colorant include inorganic pigments such as metal oxides and metal powders, and organic pigments such as azo-based, phthalocyanine-based, additive-based, acidic or basic dye-based lakes. Examples of ultraviolet absorbers include 2-hydroxy-4-octoxybenzophenone; benzophenones such as 2-hydroxy-4-methoxy-5-sulfobenzophenone; 2- (2′-hydroxy-5-methylphenyl) benzotriazole Benzotriazoles; phenyl salsylates; hindered amines such as pt-butylphenyl salsylates. Antiaging agents include amines; phenols; bisphenyls; hindered amines, such as di-t-butyl-p-cresol; bis (2,2,6,6-tetramethyl-4-piperazyl). ) Sebacate.
[0040]
【The invention's effect】
As described above in detail, the solar cell cover material of the present invention is a transparent resin film having good moisture resistance and light resistance, and therefore, by using this solar cell cover material as a transparent protective member for solar cells, It is possible to provide a solar cell that can cope with a flexible shape, is lightweight, has excellent impact resistance, and has no durability and no problem of UV deterioration or rusting.
[0041]
The solar cell cover material combined sealing film of the present invention is formed by integrating the solar cell cover material of the present invention and the EVA film. By using it, it is possible to efficiently produce a solar cell that is lightweight and has excellent impact resistance and durability with good workability.
[0042]
The solar cell of the present invention uses the cover material for a solar cell of the present invention as a front side and / or back side transparent protective member, can correspond to a flexible shape, is lightweight, and has excellent impact resistance and durability. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a solar cell cover material of the present invention.
FIG. 2 is a cross-sectional view showing an embodiment of a transparent high moisture-proof film according to the present invention.
FIG. 3 is a cross-sectional view showing an embodiment of a transparent high moisture-proof film according to the present invention.
FIG. 4 is a cross-sectional view showing an embodiment of a sealing film for a solar cell cover material according to the present invention.
FIG. 5 is a cross-sectional view showing an embodiment of a solar cell of the present invention.
FIG. 6 is a cross-sectional view showing a conventional solar cell.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cover material for solar cells 2 Transparent high moisture-proof film 3 Transparent high light-resistant film 4 UV absorption adhesive sheet 5 Cover material for solar cell cover material 6 EVA film 7 Back cover 8 EVA film 9 Silicon power generation element 10 Solar cell

Claims (5)

A cover material used as a transparent protective member of the solar cell element, and a transparent high light film and the transparent high moisture barrier film, Ri Na and integrally laminated with an adhesive formulated with UV absorbers,
The transparent high moisture-proof film is composed of a laminated film in which two coated transparent films coated with an inorganic oxide are bonded to each other.
The transparent high light resistance film is a fluororesin film, or a resin composition in which an ultraviolet absorber is kneaded into one or more kinds of resins made of acrylic, polycarbonate, polyethylene terephthalate and polyethylene naphthalate is formed into a film. And
A cover material for a solar cell, wherein the adhesive containing the ultraviolet absorber is obtained by adding an ultraviolet absorber to an epoxy, acrylic, urethane or ester adhesive resin . The solar cell cover material according to claim 1, wherein the transparent film is a polyethylene terephthalate film, and the inorganic oxide is silica or alumina. 3. The fluororesin according to claim 1 , wherein the fluororesin is polytetrafluoroethylene, 4-fluoroethylene-perchloroalkoxy copolymer, 4-fluoroethylene-6-fluoropropylene copolymer, 2-ethylene-4- A solar cell cover material, which is one or more selected from the group consisting of a fluorinated ethylene copolymer, poly (3-fluoroethylene chloride), polyvinylidene fluoride, and polyvinyl fluoride. A sealing film that also serves as a transparent protective member for a solar battery cell, wherein the solar battery cover material according to any one of claims 1 to 3 and an ethylene-vinyl acetate copolymer film are laminated and integrated. An encapsulating film that also serves as a cover material for solar cells. The solar cell formed by sealing the cell for solar cells between a surface side protection member and a back surface side protection member, This surface side and / or back surface side protection member are any one of Claims 1 thru | or 3. A solar cell, which is a cover material for a solar cell.

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