JP2001094135A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable solar cell module in which coating members are not separated from each other, even after a long-term exposure of the solar cell module at outdoors. SOLUTION: A photovoltaic element is coated on the light-receiving face side and/or the opposite side, with a multilayer sheet for sealing a solar cell comprising different kinds of organic polymer resin layers, where at least two adjacent layers are formed simultaneously by co-extruding thermoplastic polymer resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell module using a multilayer laminated sheet for encapsulating a solar cell which does not delaminate even when used outdoors for a long period of time and has excellent durability.

[0002]

2. Description of the Related Art In recent years, awareness of environmental issues has been increasing worldwide. Above all, the fear of global warming caused by CO ₂ emission is serious, and the demand for clean energy is increasing more and more. At present, solar cells are safe and easy to handle,
It can be said that it is promising as a clean energy source.

FIG. 6 is a schematic sectional view of the basic structure of a solar cell module. In FIG. 6, 601 is a photovoltaic element, 602 is a sealing resin, 603 is a front member, and 604 is a back member. The sunlight passes through the surface member 603 and the sealing resin 602 and enters the light receiving surface of the photovoltaic element 601 to be converted into electric energy. The generated electricity is taken out from an output terminal (not shown).

[0004] The photovoltaic element cannot withstand outdoor use under severe environments. This is because the photovoltaic element itself is susceptible to corrosion and easily damaged by an external impact or the like. Therefore, it is necessary to cover and protect the photovoltaic element with a covering material. Most commonly, a photovoltaic element is placed between a transparent and weather-resistant surface member such as a glass or fluororesin film and a back surface member excellent in moisture-proof and electrical insulation such as an aluminum-laminated tedlar film or polyester film. A method of sandwiching and laminating the same through a sealing material resin such as an ethylene-vinyl acetate copolymer (EVA).

[0005] Since the solar cell module is used outdoors for a long period of time, high durability is required. Of course, the durability of the photovoltaic element is excellent, but the coating material is also required to have excellent weather resistance and heat resistance. However, when exposed outdoors for more than 10 years, light deterioration and heat deterioration of the coating material cannot be avoided, and yellowing of the sealing material resin and peeling between members may become apparent. The yellowing of the sealing material resin causes a decrease in the amount of incident light, and the electric output decreases. In addition, peeling between members causes corrosion of the photovoltaic element or a metal member attached to the element due to intrusion of moisture into the peeled portion, leading to deterioration of solar cell performance.

[0006] In order to solve such a problem, the durability of the solar cell coating material has been conventionally improved. For peeling between members, addition of an adhesion improver to the sealing material resin or the like has been proposed. Easy adhesion processing and the like are performed.

Specifically, the addition of a silane coupling agent or an organic titanate compound to a sealing resin is disclosed in Japanese Patent Publication No. 6-35.
575 and JP-A-9-36405, and when a film is used as a surface member, a surface to be bonded to a sealing material resin is subjected to corona treatment, plasma treatment, ozone treatment, UV irradiation, electron beam irradiation, and flame treatment. Performing such surface treatments is disclosed in JP-A-9-36405.

[0008]

However, the silane coupling agent and the organic titanate compound are susceptible to hydrolysis by moisture. When a battery module is manufactured, the silane coupling agent or the organic titanate compound reacts with moisture in the air during storage of the sheet and gradually loses its activity, so that the effect of improving the adhesiveness tends to be insufficient. In addition, the silane coupling agent or the organic titanate compound, which is responsible for maintaining the adhesiveness between the members even when the solar cell module is exposed to the outdoors, is gradually decomposed under the influence of light, heat, moisture, etc., and the adhesive strength is reduced. .

On the other hand, since surface treatments such as corona treatment and plasma treatment deteriorate with time, there is no problem if they are adhered immediately after the treatment, but if they are not, sufficient adhesive strength may not be obtained. Further, the cost is high due to poor productivity of the surface treatment step.

[0010] For these reasons, it is difficult to say that peeling between members in the covering material of the solar cell module has been sufficiently improved. Recently, a roofing-integrated solar cell module, in which a photovoltaic element is directly attached to the roofing material, is installed as a solar cell module for electric power installed on the roof of a house.
Development is rapidly progressing because it is advantageous in terms of workability and cost, but such modules have a module temperature of 80 ° C or more due to poor ventilation on the back side compared to the conventional rooftop type. It gets hot. Needless to say, thermal degradation of the coating material is promoted when used at high temperatures.Because the sealing resin is softened, there is a possibility that Peeling is more likely to occur.

An object of the present invention is to solve the above-mentioned problems and to provide a highly reliable solar cell module in which there is no peeling between coating members even when exposed outdoors for a long period of time.

[0012]

In order to achieve the above object, a solar cell module according to the present invention is a sheet in which different kinds of organic polymer resin layers are laminated, wherein the organic polymer resin A laminated sheet of a thermoplastic organic polymer resin in which at least any two adjacent layers are simultaneously formed and laminated by co-extrusion, is formed on the light receiving surface side of the photovoltaic element and / or the light. The opposite side to the light receiving surface side is covered.

According to such a configuration, a solar cell module having excellent reliability without peeling between the covering members even in outdoor exposure for a long time can be obtained.

It is preferable that at least one of the co-extruded organic polymer resins is a resin having a Vicat softening point of 40 ° C. or higher and 110 ° C. or lower, whereby a member such as a photovoltaic element is bonded. Thus, when a solar cell module is manufactured, a solar cell module can be easily manufactured by heat compression bonding at a relatively low temperature.

It is preferable that at least one of the coextruded organic polymer resin layers contains an ultraviolet absorber and / or a hindered amine light stabilizer, whereby deterioration of the resin due to light or heat is prevented. Suppression is suppressed, and peeling is less likely to occur.

Further, when the photovoltaic element is bonded to a roof material, a highly reliable roof material-integrated solar cell module can be provided in which the coating material does not peel even under conditions of use at high temperatures. That is, even if the sealing material resin softens at a high temperature, stable adhesiveness can be maintained.

Further, one of the co-extruded adjacent thermoplastic organic polymer resins is made of polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polycarbonate resin, nylon resin, acrylic resin, polyethylene resin. , Polypropylene resin, tetrafluoroethylene-ethylene copolymer (E
TFE), polychlorotrifluoroethylene (PCTF
E) Resin, tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA), polyvinylidene fluoride (PVdF) resin, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and vinylidene fluoride copolymer The main component being selected from the group consisting of coalesced units, the other being ethylene-vinyl acetate copolymer (EVA), ethylene- (meth) acrylate copolymer, ethylene- (meth) acrylic acid copolymer, Ethylene- (meth) acrylate- (meth)
Acrylic acid terpolymer, and ethylene- (meth) acrylate-maleic anhydride terpolymer selected from the group consisting mainly of:
An excellent solar cell module that maximizes the effects of the present invention can be obtained. That is, by applying these resins to the present invention, more remarkable effects can be obtained than when other resins are applied.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The multilayer laminated sheet for encapsulating a solar cell according to the present invention can be widely applied as a covering member constituting a solar cell module. That is, a transparent weather-resistant covering member that covers the light receiving surface side of the photovoltaic element, a covering member that protects the back side of the photovoltaic element, or an adhesive between the members including the photovoltaic element and the reinforcing plate. It can be used as a layer.

The multilayer sheet for encapsulating a solar cell according to the present invention is formed by laminating two or more layers of different kinds of organic polymer resins, and at least one of two adjacent layers is formed of a thermoplastic organic resin. It is performed by co-extrusion of a polymer resin.

The thermoplastic polymer resin can be selected from various optional ones. However, in order to exhibit stable performance as a covering member of a solar cell module, weather resistance, heat resistance, cold resistance, moisture resistance, and the like are required. Impact resistance and electrical insulation are required. In addition, in normal thermocompression bonding, it is preferable to co-extrude two types of thermoplastic polymer resins that do not provide sufficient adhesion reliability while using a solar cell module. Specifically, one of the resins (A layer) is made of polyethylene terephthalate (PET) resin or polyethylene naphthalate (PE).
N) resin, polycarbonate resin, nylon resin, acrylic resin, polyethylene resin, polypropylene resin, tetrafluoroethylene-ethylene copolymer (ETF
E), polychlorotrifluoroethylene (PCTFE)
Resin, tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA), polyvinylidene fluoride (PVdF) resin, tetrafluoroethylene-
The main component is selected from the group consisting of hexafluoropropylene copolymer (FEP) and vinylidene fluoride copolymer, and the other resin (layer B) is ethylene-vinyl acetate copolymer (EVA), ethylene -(Meth) acrylate copolymer, ethylene- (meth) acrylate copolymer, ethylene- (meth) acrylate-
It is preferable that the main component is selected from the group consisting of a (meth) acrylic acid terpolymer and an ethylene- (meth) acrylate-maleic anhydride terpolymer.

If the multilayer laminate sheet for encapsulating a solar cell of the present invention is used as a surface covering material in the layer A, the tetrafluoroethylene-ethylene copolymer is preferred from the viewpoint of weather resistance and transparency. (ETFE), polychlorotrifluoroethylene (PCTFE) resin, tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA), polyvinylidene fluoride (PVdF)
Resin and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) are preferable, and when layer A constitutes the outermost surface of the solar cell module, tetrafluoroethylene-ethylene copolymer is preferable in terms of both weather resistance and mechanical strength. Polymers (ETFE) are preferred. On the other hand, if it is used as a back surface coating material, polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, and polycarbonate resin from the viewpoint of heat resistance, cold resistance, flexibility, availability, and economy. , A nylon resin, an acrylic resin, a polyethylene resin, and a polypropylene resin are preferable, and a polyethylene terephthalate (PET) resin, a polycarbonate resin, and a polypropylene resin are most preferable in terms of mechanical strength and electrical insulation.

Among the resins of the layer B, ethylene-vinyl acetate copolymer (EVA) and ethylene-methyl acrylate copolymer (E
MA), ethylene-ethyl acrylate copolymer (EE
A), ethylene-methyl methacrylate copolymer (EM
MA), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl (meth) acrylate- (meth) acrylic acid terpolymer and ethylene- (meth) ) Methyl acrylate-maleic anhydride terpolymer is preferable, and if it is used as a surface coating material, from the viewpoint of transparency, any resin has an ethylene content of 60 wt% or more and 90 w / w.
It is desirably t% or less. Ethylene content of 60
If the content is less than wt%, the weather resistance of the resin is reduced, and yellowing and white turbidity tend to occur. If the ethylene content exceeds 90 wt%, the crystallinity of the resin increases, and the transparency decreases.

The resin of the layer B has a Vicat softening point of 40 ° C.
It is desirable that the temperature be 110 ° C. or lower. If the Vicat softening point is lower than 40 ° C., the coating softens under outdoor use, causing deformation of the coating layer and poor adhesion to the adherend. When the Vicat softening point exceeds 110 ° C., the resin is sufficiently melted even if an attempt is made to bond the B layer to another member, for example, a photovoltaic element or the like, by heating and pressing at about 150 ° C., which is a general method for manufacturing a solar cell module. And poor adhesion.

Since the solar cell module is used under a severe outdoor environment, it is still often insufficient to use a resin having essentially excellent weather resistance. In particular, the resin of the layer B alone is gradually decomposed by light, heat and moisture, but is gradually decomposed and appears as yellowing, cloudiness, a decrease in mechanical strength, a decrease in adhesive strength, and the like. Therefore, photo-oxidation of resin,
In order to suppress thermal oxidation and improve weather resistance, it is desirable to add an ultraviolet absorber and / or a hindered amine light stabilizer. The added amount is about 0.1 to 0.5 parts by weight of the ultraviolet absorber and about 0.1 to 0.3 parts by weight of the light stabilizer based on 100 parts by weight of the resin.

As the ultraviolet absorber, known compounds are used. The chemical structure is roughly classified into salicylic acid, benzophenone, benzotriazole, and cyanoacrylate.

Examples of salicylic acids include phenyl salicylate, p-tert-butylphenyl salicylate, p-
There is octylphenyl salicylate.

In the benzophenone series, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, and 2,2'-dihydroxy-4 -Methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-
5-sulfobenzophenone, bis (2-methoxy-4-
(Hydroxy-5-benzophenone) methane.

As benzotriazoles, 2- (2 '
-Hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butyl Phenyl) benzotriazole, 2- (2′-hydroxy-3′-t)
tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′,
5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ',
5′-di-tert-amylylphenyl) benzotriazole, 2- {2′-hydroxy-3 ′-(3 ″,
4 ", 5", 6 "-tetrahydrophthalimidomethyl)
-5'-methylphenyl @ benzotriazole, 2,2
-Methylenebis {4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol}.

Examples of the cyanoacrylate include 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate and ethyl-2-cyano-3,3'-diphenyl acrylate.

It is preferable to add at least one kind of the above-mentioned ultraviolet absorbers.

The hindered amine light stabilizer alone can prevent photo-oxidation and thermal oxidation due to radicals, but exhibits a remarkable synergistic effect when used in combination with an ultraviolet absorber. Of course, some other than hindered amines function as light stabilizers, but are often colored, which is not desirable for the solar cell sealing application of the present invention.

Examples of the hindered amine light stabilizer include dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate of dimethyl succinate and 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}], N, N'-
Bis (3-aminopropyl) ethylenediamine 2,4
-Bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-
1,3,5-triazine condensate, bis (2,2,6,6
-Tetramethyl-4-piperidyl) sebalate, 2-
(3,5-di-tert-4-hydroxybenzyl)-
Bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2-n-butylmalonate and the like are known.

It is preferable to use a low-volatility ultraviolet absorber and a light stabilizer in consideration of the usage environment of the solar cell module.

When it is assumed that the solar cell module is used in a more severe environment, it is preferable to improve the adhesion between the layer B resin and the adherend. The adhesive strength can be improved by adding a silane coupling agent or an organic titanate compound to the B layer resin. Addition amount is resin 100
It is generally 0.1 to 3.0 parts by weight based on parts by weight.
Specific examples of the silane coupling agent include vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ
-Aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane and the like.

Further, in order to prevent thermal oxidation during co-extrusion and perform stable extrusion, a thermal oxidation inhibitor may be added to the B layer resin. The appropriate amount of addition is 0.1 to 1.0 part by weight based on 100 parts by weight of the resin. The chemical structure of antioxidants is monophenol-based, bisphenol-based,
It is roughly classified into polymer type phenol type, sulfur type and phosphoric acid type.

In the case of monophenol, 2,6-di-ter
There are t-butyl-p-cresol, butylated hydroxyanisole, and 2,6-di-tert-butyl-4-ethylphenol.

For bisphenols, 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol) and 2,2'-methylene-bis- (4-ethyl-6-
tert-butylphenol), 4,4′-thiobis-
(3-methyl-6-tert-butylphenol),
4,4'-butylidene-bis- (3-methyl-6-te
rt-butylphenol), 3,9-bis {1,1-dimethyl-2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl} 2,4,8,10 -Tetraoxaspiro 5,5
Undecane.

As the high molecular weight phenols, 1,1,3-
Tris- (2-methyl-4-hydroxy-5-tert
-Butylphenyl) butane, 1,3,5-trimethyl-
2,4,6-tris (3,5-di-tert-butyl-
4-hydroxybenzyl) benzene, tetrakis-dimethylene-3- (3 ', 5'-di-tert-butyl-)
4'-hydroxyphenyl) propionate methane,
Bis (3,3'-bis-4'-hydroxy-3'-te
rt-butylphenyl) butyric acid glycol ester, 1,3,5-tris (3 ′, 5′-di-t)
tert-Butyl-4'-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione and triphenol (vitamin E) are known.

On the other hand, sulfur-based compounds include dilauryl thiodipropionate, dimyristyl thiodipropionate, disnaryl thiopropionate and the like.

In the phosphoric acid system, triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, 4,4′-butylidene-bis- (3-
Methyl-6-tert-butylphenyl-di-tridecyl) phosphite, cyclic neopentanetetraylbis (octadecylphosphite), tris (mono and / or diphenylphosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro -9-oxa-10-phosphaphenathrene-10
-Oxide, 10- (3,5-di-tert-butyl-4-hydrodibenzyl) -9,10-dihydro-9
-Oxa-10-phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-
Oxa-10-phosphaphenanthrene, cyclic neopentanetetraylbis (2,4-di-tert-
Butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-tert-methylphenyl) phosphite, 2,2-methylenebis (4,6
-Tert-butylphenyl) octyl phosphite.

It is effective to add the above-mentioned ultraviolet absorber, hindered amine light stabilizer, silane coupling agent, organic titanate compound and thermal antioxidant to the B layer resin having relatively poor weather resistance. A added to A layer resin
It is of course possible to enhance the processing stability at the time of extrusion as the layer resin itself and the weather resistance at the time of outdoor exposure as the whole multilayer laminated sheet.

FIG. 1 shows an example of a schematic cross-sectional view of a solar cell module and a solar cell module laminate before lamination that can be suitably manufactured using the solar cell sealing multilayer laminate sheet of the present invention. In FIG. 1, 101 is a photovoltaic element, 102 is a surface sealing material resin layer, 103 is a surface protection resin layer, 104 is a back surface sealing material resin layer, 105 is a back surface protection resin layer, and 106 is surface sealing. And 107, a backside sealing multilayer laminated sheet.

The multi-layer laminated sheet 106 for surface encapsulation is obtained by laminating a surface protective resin and a surface encapsulant resin by co-extrusion, and the same applies to the multi-layer laminated sheet for back encapsulation.

Co-extrusion is a multilayer extrusion molding method that achieves joining and integration at the same time as film or sheet molding, and is roughly classified into the T-die method (cast molding, extrusion coating molding) and the round die method (inflation molding). Divided. In any case, the multilayer laminated film for encapsulating a solar cell of the present invention can be produced. However, 1) excellent wall thickness accuracy, 2) high transparency of resin, and 3) sheet molding of a thick film are possible. Then, the T-die method is more preferable. The surface protection resin layer 103 and the back surface protection resin layer 105 correspond to the A layer, and the surface sealing material resin layer 102 and the back surface sealing resin layer 104 correspond to the B layer.

As the photovoltaic element 101, 1) crystalline silicon solar cell, 2) polycrystalline silicon solar cell, 3) amorphous silicon solar cell, 4) copper indium selenide solar cell, 5) compound semiconductor solar cell, etc. Various known elements may be selected and used depending on the purpose. These photovoltaic elements are connected in series or in parallel according to a desired voltage or current. Alternatively, a desired voltage or current can be obtained by integrating a photovoltaic element on an insulated substrate.

A method for forming a solar cell module using the above-described photovoltaic element, multilayer laminated sheet for surface sealing, and multilayer laminated sheet for back sealing will now be described.

In order to seal the photovoltaic element with a resin to obtain a solar cell module, a method of heating and pressing is generally used. That is, a multilayered sheet is arranged above and below the photovoltaic element such that the sealing material resin layer is in contact with the element to form a solar cell module laminate, and the solar cell module can be formed by heat-pressing.

As the method of thermocompression bonding, conventionally known vacuum lamination, roll lamination and the like can be variously selected and used.

FIG. 2 is a schematic cross-sectional view of a roofing-integrated solar cell module and a roofing-integrated solar cell module laminate before lamination that can be suitably manufactured using the solar cell encapsulating multilayer laminated sheet of the present invention. This is an example. 2, reference numeral 201 denotes a photovoltaic element, 202 denotes a surface sealing resin layer, 203 denotes a surface protection resin layer, 204 denotes a back surface sealing resin layer, 205 denotes a back surface protection resin layer, and 206 denotes an adhesive resin. layer,
207 is a roofing material, 208 is a multilayer laminated sheet for surface sealing,
209 is a multilayer laminated sheet for back surface sealing.

In this example, the multilayer laminated sheet for sealing the back surface is 3
It is a layer, and the roof material is stuck on the outside,
Otherwise, it can be manufactured in exactly the same manner as the module of FIG. Further, the back sealing resin 204 and the adhesive resin 206 may be the same.

The roofing material 207 can be used by variously selecting from a metal plate, a slate board, a gypsum board, a tile, a glass fiber reinforced plastic, glass and the like. Among them, a weather-resistant metal plate such as a galvanized steel plate, a galvalume steel plate, a stainless steel plate, and an aluminum plate is lightweight and easy to process, and thus is suitably used for a roof material integrated solar cell module.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a multilayer laminated sheet for solar cell encapsulation having the above structure, a solar cell module using the same, and a solar cell module integrated with a roofing material will be described in detail with reference to examples. The multilayered sheet for solar cell encapsulation and the solar cell module according to the present invention are not limited to the following examples at all, and can be variously modified within the scope of the invention.

[Production Example of Multilayer Laminated Sheet for Solar Cell Encapsulation] (Multilayer Laminated Sheet for Solar Cell Encapsulation A) 100 parts by weight of pellets of EVA resin (vinyl acetate content 25 wt%, Vicat softening point 54 ° C.) 0.25 parts by weight of γ-methacryloxypropyltrimethoxysilane as a silane coupling agent and 2-hydroxy-
0.3 parts by weight of 4-n-octoxybenzophenone, bis (2,2,6,6-tetramethyl-4) as a light stabilizer
(Piperidyl) sebacate (0.1 part by weight) and tris (mono-nonylphenyl) phosphite (0.2 part by weight) as an antioxidant were sufficiently stirred and mixed, and then heated and melted to obtain a biaxial mixture. It was extruded from a co-extrusion T-die using an extruder. At the same time, the ETFE powder heated and melted is supplied to the same T die, and E
Merge with VA resin, ETFE thickness 50μm, EVA
ETFE / EVA laminated sheet having a thickness of 500 μm was prepared.

(Multilayer laminated sheet B for sealing solar cells) Ethylene-methyl acrylate-maleic anhydride terpolymer (methyl acrylate content 15 wt%, maleic anhydride content 3 wt%, Vicat softening point 55 ° C.) 0.3% by weight of 2-hydroxy-4-n-octoxybenzophenone as an ultraviolet absorber and bis (2,2,6,6-tetramethyl-) as a light stabilizer.
The mixture to which 0.1 part by weight of 4-piperidyl) sebacate had been added was sufficiently stirred and mixed, and then heated and melted by a twin-screw extruder. On the other hand, dried PET chips were
It was heated and melted by a screw extruder. These were supplied to a three-layer co-extrusion molding T-die, and the resins were combined and extruded in the die. Thereby, the EMA copolymer thickness of 250 μm, PE
100 μm thick EMA copolymer / PET / EMA
A three-layer copolymer sheet was prepared.

(Multilayer laminated sheet C for solar cell encapsulation) In the production example of the multilayer laminated sheet A for solar cell encapsulation, EVA
EMAA resin (methacrylic acid content 15wt)
%, Vicat softening point 64 ° C.) to produce an ETFE / EMAA laminated sheet in the same manner.

(Multilayer laminated sheet D for solar cell encapsulation) In the production example of the multilayer laminated sheet B for solar cell encapsulation, PET was used.
An EMA copolymer / PEN / EMA copolymer three-layer laminated sheet was produced in the same manner except that the resin was changed to PEN resin.

(Multilayer laminated sheet E for encapsulating solar cells) EE
0.25 parts by weight of γ-methacryloxypropyltrimethoxysilane as a silane coupling agent and 100 parts by weight of silane coupling agent per 100 parts by weight of pellets of resin A (ethyl acrylate content: 17 wt%, Vicat softening point: 57 ° C.); 0.3 parts by weight of hydroxy-4-n-octoxybenzophenone, bis (2,2,6,6
-Tetramethyl-4-piperidyl) sebacate, 0.2 parts by weight, and 0.1 parts by weight of pentaerythrityl-tetrakis [3- (3,5-ditert-butyl-4-hydroxyphenyl)] propionate as an antioxidant, respectively. After the addition was sufficiently stirred and mixed, the mixture heated and melted was extruded from a co-extrusion molding T-die using a twin-screw extruder. At the same time, the polypropylene resin powder was heated and melted by an extruder, supplied to the same T die, and merged with the EEA resin in the die. After being extruded from a T-die onto a casting drum and cooled to form a sheet, the polypropylene resin layer was biaxially stretched through a longitudinal stretching machine and a transverse stretching machine. Thus, the thickness of the polypropylene is 100 μm and the thickness of the EEA is 25.
A 0 μm polypropylene / EEA laminated sheet was produced.

(Embodiment 1) This embodiment will be described with reference to FIG.

First, the photovoltaic element group 301 in which a plurality of photovoltaic elements are connected in series, the ETFE / EVA sheet 307 of the multilayer laminate sheet A for solar cell encapsulation, and the EMA of the multilayer laminate sheet B for solar cell encapsulation are shared. A polymer / PET / EMA copolymer sheet 308 and a galvalume steel sheet (0.4 mm in thickness) 306 for a roof material are stacked to form a solar cell module laminate 300.

This laminate was heated at 150 ° C. for 30 minutes using a laminator of a vacuum heating and pressure bonding method to produce a solar cell module. The electric output was taken out from the back surface of the photovoltaic element group through the opening of the back cover material.

Finally, the steel plate portion, which extends outside the element group and is covered with ETFE / EVA, was bent by a roller former to form the steel plate so as to function as a roof material.

Thus, a plurality of roofing-material-integrated solar cell modules were manufactured, and the following evaluation was performed to confirm long-term reliability of the modules under outdoor exposure.

(1) Weather resistance test A solar cell module was put into a sunshine weatherometer (manufactured by Suga Test Instruments Co., Ltd.) and irradiated with light from a xenon lamp (irradiation intensity: 3 SUN, atmosphere: black panel temperature 83 ° C./humidity 50%). An accelerated weathering test in which rainfall was repeated every 2 hours for 8 minutes while performing RH) was performed, and changes in appearance after 5000 hours were observed. Observation results are shown in Table 1 as ○ when there was no change, and the situation was simply commented in Table 1 when there was a change. In addition, before and after the test, the electric output of the solar cell module under AM1.5, 100 mW / cm ² light irradiation was measured, and the relative decrease rate of the electric output of 10 modules was determined (see Table 1).

(2) High-Temperature and High-Humidity Test The solar cell module was put into an environmental tester (manufactured by Tabai Espec Corp.) and subjected to 100 ° C. under 85 ° C./85% RH.
Left for 0 hours. Changes in appearance after the test were observed. Observation results are shown in Table 1 as ○ when there was no change, and the situation was simply commented in Table 1 when there was a change.
In addition, AM1.5, 1
The electric output under light irradiation of 00 mW / cm ² was measured, and
The relative decrease rate of the electric output of the 0 module average was determined (see Table 1).

(3) Temperature / humidity cycle test A temperature / humidity cycle test of −40 ° C./30 minutes, 85 ° C./85% RH / 20 hours was performed for 10 cycles, and changes in the appearance of the solar cell module after the test were observed. . Observation results
Those without change are shown in Table 1 as "O", and those with change were briefly commented on the situation in Table 1. In addition, AM1, 5, 100 mW /
The electric output under light irradiation of cm ² was measured, and the relative decrease rate of the electric output on the average of 10 modules was determined (see Table 1).

(4) Heat Resistance Test The solar cell module was allowed to stand in an atmosphere at 95 ° C. for 1000 hours, and changes in the appearance were observed. The situation was briefly commented in Table 1.

(Example 2) In Example 1, the ETFE /
ET of EVA sheet for multilayer laminate sheet C for solar cell encapsulation
A plurality of roofing-material-integrated solar cell modules were fabricated and evaluated in exactly the same manner except that the FE / EMAA sheet was used. Table 1 shows the evaluation results.

(Example 3) In Example 2, the EMA copolymer / PEN / PEN / EMA copolymer sheet was replaced with the EMA copolymer / PEN of the multilayer laminate sheet D for solar cell encapsulation.
A plurality of roofing-material-integrated solar cell modules were prepared and evaluated in exactly the same manner except that the / EMA copolymer sheet was used. Table 1 shows the evaluation results.

(Embodiment 4) This embodiment will be described with reference to FIG.

First, a group of photovoltaic elements 401 in which a plurality of photovoltaic elements are connected in series, a tempered glass 402 (thickness: 3.3 mm), an EVA sheet 403 (thickness: 600 μm)
m), a solar cell module laminate 400 is formed by stacking the polypropylene / EEA sheets 406 of the multilayer laminate sheet E for solar cell encapsulation.

The EVA sheet used here is a silane coupling agent based on 100 parts by weight of pellets of EVA resin (vinyl acetate content: 33 wt%, Vicat softening point: 40 ° C. or less). 0.25 parts by weight of trimethoxysilane, 0.3 parts by weight of 2-hydroxy-4-n-octoxybenzophenone as an ultraviolet absorber, bis (2,2,2) as a light stabilizer
0.1 parts by weight of 6,6-tetramethyl-4-piperidyl) sebacate, 0.2 parts by weight of tris (mono-nonylphenyl) phosphite as an antioxidant, 2,5-dimethyl-2,5- as a crosslinking agent Bis (t-butylperoxy) hexane, to which 1.5 parts by weight of each had been added, was sufficiently stirred and mixed, and then heated and melted using a twin-screw extruder, taking care not to decompose the crosslinking agent. It was extruded from a T die and molded.

This laminate was heated at 150 ° C. for 30 minutes using a laminator of a vacuum heating and pressure bonding method to produce a solar cell module. The electric output was taken from the back surface of the photovoltaic element group through the opening of the back cover material.

Thus, a plurality of solar cell modules were manufactured and evaluated. Table 1 shows the evaluation results.

(Comparative Example 1) EVA and ETFE were separately molded in a multilayer laminated sheet A for encapsulating a solar cell, and an ETFE film having a thickness of 50 μm and an EV having a thickness of 500 μm were formed.
An A sheet was prepared. Further, in the multilayer laminate sheet B for solar cell encapsulation, the EMA copolymer and PET were separately molded, and the EMA copolymer sheet having a thickness of 250 μm and the
A 00 μm PET film was produced.

A method for manufacturing a solar cell module using these sheets and films will be described with reference to FIG.

A photovoltaic element group 501, an ETFE film 502, an EVA sheet 503, an EMA copolymer sheet 504, a PET film 505, and a galvalume steel plate (0.4 mm thick) 506 for a roof material are stacked to stack a solar cell module. The body was 500. Prior to this, ETFE was used to improve the adhesion between the film and the sheet.
Plasma treatment was performed on one side of the film, and corona discharge treatment was performed on both sides of the PET film.

Thereafter, a plurality of roofing-material-integrated solar cell modules were manufactured and evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.

(Comparative Example 2) In the multilayered sheet C for encapsulating a solar cell, EMAA and ETFE were separately molded,
50 μm thick ETFE film and 500 μm thick E
An MAA sheet was prepared. In the multilayer laminate sheet B for solar cell encapsulation, the EMA copolymer and PET were separately molded to produce a 250 μm-thick EMA copolymer sheet and a 100 μm-thick PET film.

Thereafter, the EVA sheet of Comparative Example 1 was
A plurality of roofing-material-integrated solar cell modules were produced and evaluated in exactly the same manner except that the AA sheet was used.
Table 1 shows the evaluation results.

(Comparative Example 3) In the multilayer laminate sheet E for encapsulating a solar cell, EEA and polypropylene were separately molded to produce an EEA sheet having a thickness of 250 µm and a biaxially oriented polypropylene film having a thickness of 100 µm.

In Example 4, polypropylene / EE
A solar cell module laminate was prepared using the EEA sheet and the polypropylene film instead of the A sheet. Otherwise, a plurality of solar cell modules were prepared in the same manner and evaluated. Table 1 shows the evaluation results.

[0082]

[Table 1]

The solar cell modules of Examples 1, 2, 3, and 4 showed no change in appearance and a slight decrease in electric output in any of the evaluations. Peeling occurred.

In Comparative Examples 1 and 2, peeling between the ETFE film and EVA or EMAA became apparent in the bent portion. In the high-temperature high-humidity test and the temperature-humidity cycle test, peeling occurred partially at the interface between the PET and the EMA copolymer, and the back surface of the element was corroded by moisture penetrating into the peeling interface, resulting in a decrease in electric output.

On the other hand, in Comparative Example 3, polypropylene and EE
In each test, the polypropylene peeled more than the end face due to the inherently low adhesion to A.

[0086]

According to the present invention, there is provided a sheet in which different kinds of organic polymer resin layers are laminated, wherein at least any two adjacent layers of the organic polymer resin layers are co-extruded. At the same time, the multilayer laminated sheet for sealing the solar cell, which is a thermoplastic organic polymer resin, which is formed and laminated at the same time, allows the light receiving surface side of the photovoltaic element and / or
Alternatively, by covering the side opposite to the light receiving surface side, a highly reliable solar cell module can be provided in which there is no peeling between the covering members even during long-term outdoor exposure.

[Brief description of the drawings]

FIG. 1 is an example of a schematic sectional view showing (a) a solar cell module laminate and (b) a solar cell module of the present invention.

FIG. 2 shows (a) a roof material-integrated solar cell module laminate and (b) a roof material-integrated solar cell module of the present invention.
It is an example of a schematic sectional view showing.

FIG. 3 (a) a solar cell module laminate of Example 1,
It is an outline sectional view showing (b) a solar cell module and (c) a solar cell module after bending.

FIG. 4 is a schematic sectional view illustrating (a) a solar cell module laminate and (b) a solar cell module of Example 4.

FIG. 5 is a schematic sectional view illustrating a solar cell module laminate of Comparative Example 1.

FIG. 6 is an example of a schematic cross-sectional view illustrating a basic structure of a solar cell module.

[Explanation of symbols]

101, 201, 301, 401, 501, 601 Photovoltaic element 102, 202 Surface sealing resin 103, 203 Surface protection resin 104, 204 Back sealing resin 105, 205 Back protection resin 106, 208 For surface sealing Multilayer laminated sheet 107, 209 Multilayer laminated sheet for back surface sealing 206 Adhesive resin 207 Roofing material 300, 400, 500 Solar cell module laminate 302 EVA resin 303 ETFE resin 304 EMA copolymer resin 305 PET resin 306, 506 Galvalume steel plate 307 ETFE / EVA sheet 308 EMA copolymer / PET / EMA copolymer sheet 402 White sheet tempered glass 403, 503 EVA sheet 404 EEA resin 405 Polypropylene resin 406 Polypropylene / EEA sheet 502 ETFE sheet Arm 504 EMA copolymer sheet 505 PET film 602 sealant resin 603 surface member 604 back member

Continued on the front page (72) Inventor Satoshi Yamada 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hidenori Shiozuka 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. F term (reference) 2E108 GG16 KK04 LL01 MM00 NN07 5F051 AA02 AA03 AA05 AA07 AA10 BA03 BA18 JA03 JA04 JA05

Claims (6)

[Claims] 1. A sheet formed by laminating different types of organic polymer resin layers, wherein at least any two adjacent layers of the organic polymer resin layers are simultaneously formed into a film by co-extrusion. A solar cell module, wherein the photovoltaic element has a light-receiving surface side and / or a side opposite to the light-receiving surface side covered with the laminated sheet made of a thermoplastic organic polymer resin. 2. At least one of the co-extruded organic polymer resins has a Vicat softening point of 40 ° C. or higher.
The solar cell module according to claim 1, wherein the solar cell module is a resin at 0 ° C or lower. 3. The solar cell module according to claim 1, wherein at least one of the co-extruded organic polymer resin layers contains an ultraviolet absorber. 4. The solar cell module according to claim 1, wherein at least one of the co-extruded organic polymer resin layers contains a hindered amine light stabilizer. 5. The solar cell module according to claim 1, wherein the photovoltaic element is bonded to a roof material. 6. One of the thermoplastic organic polymer resins that are co-extruded and adjacent to each other is made of polyethylene terephthalate (PET) resin or polyethylene naphthalate (P).
EN) resin, polycarbonate resin, nylon resin, acrylic resin, polyethylene resin, polypropylene resin,
Tetrafluoroethylene-ethylene copolymer (ETF
E), polychlorotrifluoroethylene (PCTFE)
Resin, tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA), polyvinylidene fluoride (PVdF) resin, tetrafluoroethylene-
The main component is selected from the group consisting of hexafluoropropylene copolymer (FEP) and vinylidene fluoride copolymer, and the other is ethylene-vinyl acetate copolymer (EVA), ethylene- (meth) acrylic Acid ester copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester- (meth) acrylic acid terpolymer, and ethylene- (meth) acrylic acid ester-maleic anhydride The solar cell module according to claim 1, wherein a main component is selected from the group consisting of a terpolymer.