JP2009010269A - Back surface protection sheet for solar cell module and solar cell module using the same - Google Patents

Abstract

An object of the present invention is to provide a harsh natural environment over a long period of time that can maintain the power output characteristics of a solar cell over a long period of time without causing an appearance change under high temperature and high humidity. Provided is a back protective sheet for a solar cell module having durability that can withstand, and a solar cell module using the same.
SOLUTION: A polyvinyl fluoride layer is formed by heating and drying a polyvinyl fluoride solution on one or both surfaces of a base material provided with an adhesive layer on the adhesive surface by coating with an adhesive coating agent in advance. It is characterized by.
[Selection] Figure 1

Description

  The present invention relates to a back surface protection sheet for a solar cell module and a solar cell module using the same.

  In recent years, various efforts have been made to suppress carbon dioxide emissions while interest from various countries both inside and outside Japan has increased. Increasing fossil fuel consumption leads to an increase in atmospheric carbon dioxide, and the greenhouse effect raises the Earth's temperature, significantly affecting the global environment. Various studies have been made as alternative energy for fossil fuels, but there is an increasing expectation for photovoltaic power generation, which is a clean energy source.

  Solar cells constitute the heart of a photovoltaic power generation system that directly converts sunlight energy into electricity, and semiconductors such as silicon, cadmium-tellurium, and germanium-arsenic are used. Currently, there are single crystals, polycrystalline silicon, amorphous silicon, and the like that are widely used. As its structure, a single solar cell element is not used as it is, and generally several to several tens of solar cell elements are wired in series and in parallel, and over a long period (about 20 years). In order to protect the device, various parsing is performed and unitized. The unit incorporated in this package is called a solar cell module. Generally, the surface that is exposed to sunlight is covered with glass, and the solar cell module in the solar cell is fixed and protected, and ethylene-vinyl acetate is used for the purpose of electrical insulation. The gap is filled with a filler made of a thermoplastic such as coalescence, and the back surface of the solar cell module is protected with a sealing sheet.

  Since these solar cell modules are used outdoors, they have durability such as heat resistance, weather resistance, hydrolysis resistance, moisture resistance, etc. that can withstand harsh natural environments over a long period of time in their configuration, material structure, etc. Is required, and the back protective sheet is also required to have gas barrier properties for blocking the entry of water vapor (moisture) and oxygen from the outside. This is because if the filler is peeled off or discolored due to the permeation of water vapor (moisture) or the wiring is corroded, the output of the module itself may be affected.

Conventionally, as this solar cell back surface protection sheet, a solar cell back surface protection sheet in which a fluorine resin film such as polyvinyl fluoride is laminated on both sides of a polyester film base material such as a polyethylene terephthalate (PET) film or an aluminum foil base material is often used. (For example, Patent Document 1).
JP-T 8-500214 Japanese translation of PCT publication No. 2002-520820 JP 2001-1111073 A Japanese Patent Laid-Open No. 2002-100788 JP 2002-134771 A JP 2002-26354 A

However, a fluorine resin film such as polyvinyl fluoride (PVF) is a film material excellent in weather resistance and hydrolysis resistance, and excellent in durability. Inferior, for example, when laminating by the dry lamination method, the surface of the base material to be laminated requires special surface treatment such as flame treatment or plasma treatment, leading to an increase in the manufacturing cost of the solar cell back surface protection sheet, It was an obstacle to lowering the price of battery modules.

  An object of the present invention is to provide an inexpensive back surface protection sheet for a solar cell module that does not require a special surface treatment such as a frame treatment or a plasma treatment on an adhesive surface of a base material constituting the solar cell back surface protection sheet. . In addition, it has excellent characteristics such as heat resistance, weather resistance, hydrolysis resistance, moisture resistance and light weight that can withstand harsh natural environments over a long period of time, and a gas barrier for blocking the ingress of water vapor and moisture Provided is a back surface protection sheet for a solar cell module that has durability and can maintain the power output characteristics as a solar cell for a long time without any change in appearance under a high temperature and high humidity environment. With the goal. Furthermore, it aims at providing the solar cell module using the back surface protection sheet for solar cell modules of this invention.

To achieve the above objectives,
The invention according to claim 1
It is characterized in that a polyvinyl fluoride layer is formed by heating and drying a polyvinyl fluoride solution by coating on one or both surfaces of a base material provided with an adhesive layer on the adhesive surface by coating with an adhesive coating agent in advance. It is a back surface protection sheet for solar cell modules.

The invention according to claim 2
The thickness of the said polyvinyl fluoride layer is the range of 20-300 micrometers, The back surface protection sheet for solar cell modules of Claim 1 characterized by the above-mentioned.

The invention according to claim 3
The said base material is a polyester film, The back surface protection sheet for solar cell modules of Claim 1 or 2 characterized by the above-mentioned.

The invention according to claim 4
The said base material is aluminum foil, The back surface protection sheet for solar cell modules of Claim 1 or 2 characterized by the above-mentioned.

The invention according to claim 5
The said base material is a gas-barrier film which provided the vapor deposition layer which consists of metallic aluminum or an inorganic compound, Comprising: This gas-barrier film is a base material which consists of 1 layer or more, The claim 1 or 2 characterized by the above-mentioned. It is a back surface protection sheet for solar cell modules.

The invention according to claim 6
The back protective sheet for a solar cell module according to claim 5, wherein the inorganic compound is aluminum oxide, silicon oxide, magnesium oxide, tin oxide, zinc oxide or a mixture thereof.

The invention according to claim 7 provides:
A gas barrier film provided with a vapor deposition layer made of metal aluminum or an inorganic compound is formed by sequentially laminating a transparent primer layer, a vapor deposition layer made of metal aluminum or an inorganic compound, and an overcoat layer made of a composite film on a film substrate. It is a back surface protection sheet for solar cell modules according to claim 5 or 6.

The invention according to claim 8 provides:
The thickness of the said vapor deposition layer is the range of 5-300 nm, It is a back surface protection sheet for solar cell modules of any one of Claims 5-7 characterized by the above-mentioned.

The invention according to claim 9 is:
The composite coating constituting the overcoat layer comprises a hydroxyl group-containing polymer compound and a metal alkoxide and / or a hydrolyzate thereof and / or a polymer thereof.
It is a composite film to contain, It is a back surface protection sheet for solar cell modules of any one of Claims 5-8 characterized by the above-mentioned.

The invention according to claim 10 is:
The back surface protective sheet for a solar cell module according to claim 9, wherein the hydroxyl group-containing polymer compound contains at least one of polyvinyl alcohol and poly (vinyl alcohol-co-ethylene).

The invention according to claim 11 is:
The back protection sheet for a solar cell module according to claim 9 or 10, wherein the metal alkoxide is a silane alkoxide or a silane coupling agent.

The invention according to claim 12
It is a solar cell module using the back surface protection sheet for solar cell modules of any one of Claims 1-11.

The invention according to claim 13 is:
A solar cell module in which an adhesive coating agent is coated, and a polyvinyl fluoride layer is formed by coating a polyvinyl fluoride solution on one surface of a base material provided with an adhesive layer on an adhesive surface to be bonded in advance, followed by heating and drying. 13. The solar cell according to claim 12, wherein the back surface protective sheet for a solar cell module is provided with the back surface protective sheet for the solar cell module so that the polyvinyl fluoride layer is positioned on the outermost surface of the back surface of the solar cell module. It is a module.

  According to the present invention, it is possible to provide an inexpensive back surface protection sheet for a solar cell module that does not require a special surface treatment such as a frame treatment or a plasma treatment on the adhesive surface of the base material constituting the solar cell back surface protection sheet. Therefore, when a conventional polyvinyl fluoride (PVF) film is laminated on a substrate by a dry lamination lamination method or the like, a solar cell that requires special surface treatment such as flame treatment or plasma treatment on the lamination surface of the substrate The problem of increasing the manufacturing cost of the back surface protection sheet and hindering the cost reduction of the solar cell module can be solved. In addition, it has excellent characteristics such as heat resistance, weather resistance, hydrolysis resistance, moisture resistance and light weight that can withstand harsh natural environments over a long period of time, and a gas barrier for blocking the ingress of water vapor and moisture It is possible to provide a back surface protection sheet for a solar cell module that has durability and can maintain the power output characteristics as a solar cell over a long period of time without changing appearance in a high-temperature and high-humidity environment. Furthermore, the durability that can maintain the power output characteristics as a solar cell for a long time without the appearance change under the low temperature and high humidity environment using the back surface protection sheet for the solar cell module of the present invention. A solar cell module can be provided.

  Moreover, the back surface protection sheet for solar cell modules of this invention can maintain the power output characteristic as a solar cell also in the severe acceleration | stimulation evaluation test conditions in a high temperature and high humidity environment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. 1-3 and FIGS. 6-8 are sectional drawings which show the layer structure of the one Example about the back surface protection sheet for solar cell modules of this invention. 4 and 5 are cross-sectional views showing the layer structure of one example of the gas barrier film provided with a vapor deposition layer made of metal aluminum or an inorganic compound constituting the back protective sheet for a solar cell module of the present invention. 9-11 is sectional drawing which shows the layer structure of the one Example about the solar cell module using the back surface protection sheet for solar cell modules of this invention.

  The back surface protection sheet for solar cell module of the present invention is obtained by heating and drying a polyvinyl fluoride (PVF) solution by coating on one side or both sides of a base material provided with an adhesive layer on the adhesive surface by coating with an adhesive coating agent in advance. Thus, a PVF layer is formed.

  As shown in FIG. 1, the back surface protective sheet for the solar cell module of the present invention is a polyester film base in which an adhesive layer (20) is previously provided on the adhesive surface by coating an adhesive coating agent as shown in FIG. It is the back surface protection sheet (a) for solar cell modules formed by heat-drying a polyvinyl fluoride (PVF) solution by coating on one side of the material (10) to form a PVF layer (30).

  In addition, as shown in FIG. 2, the back surface protective sheet for the solar cell module of the present invention is a polyester in which an adhesive layer (20) is previously provided on the adhesive surface by coating an adhesive coating agent as shown in FIG. It is a back surface protection sheet (b) for solar cell modules which forms a PVF layer (30) by heating and drying a polyvinyl fluoride (PVF) solution on both surfaces of a film base material (10).

  Further, as shown in FIG. 3, the back surface protective sheet for the solar cell module of the present invention has an aluminum layer in which an adhesive layer (20) is previously provided on the adhesive surface by coating an adhesive coating agent as shown in FIG. It is the back surface protection sheet (c) for solar cell modules formed by heat-drying a polyvinyl fluoride (PVF) solution with a coating on one side of a foil base material (40), and forming a PVF layer (30).

  FIG. 4 shows an example of a gas barrier film provided with a vapor deposition layer made of metal aluminum or an inorganic compound constituting the back surface protection sheet for a solar cell module of the present invention, and this vapor deposition layer was provided. The gas barrier film is made of metal aluminum or an inorganic compound obtained by sequentially laminating a transparent primer layer (52), a vapor deposition layer (53), and an overcoat layer (54) made of a composite coating on a film substrate (51). It is a gas barrier film (d) provided with a deposited layer.

  FIG. 5 shows an example of a gas barrier film provided with a vapor-deposited layer made of metal aluminum or an inorganic compound constituting the back protective sheet for a solar cell module of the present invention. It is a gas barrier film (e) provided with a vapor deposition layer made of metallic aluminum or an inorganic compound, which is laminated on two layers using an adhesive layer (not shown) using two films (d).

  As for the back surface protective sheet for solar cell module of the present invention, as shown in FIG. 6, the layer structure of one example thereof is a gas barrier film provided with a vapor deposition layer made of metal aluminum or an inorganic compound shown in FIG. 4 ( The adhesive layer (20) is previously provided on the adhesive surface by coating an adhesive coating agent on the substrate (51) side of d), and then a polyvinyl fluoride (PVF) solution is heated and dried by coating on the PVF. It is a back surface protection sheet (f) for solar cell modules formed by forming a layer (30).

Moreover, as shown in FIG. 7, the back surface protective sheet for the solar cell module of the present invention has a gas barrier property provided with a vapor deposition layer made of metal aluminum or an inorganic compound shown in FIG. 4 as shown in FIG. On the side of the overcoat layer (54) made of the composite coating of the film (d), an adhesive layer (20) is provided on the adhesive surface by coating with an adhesive coating agent in advance, and a polyvinyl fluoride (PVF) solution is formed thereon. It is the back surface protection sheet (g) for solar cell modules formed by heat-drying by coating and forming a PVF layer (30).

  Furthermore, as shown in FIG. 8, the back surface protective sheet for solar cell module of the present invention has a layer structure of one embodiment. As shown in FIG. 8, the gas barrier property of the vapor deposition layer made of metal aluminum or inorganic compound shown in FIG. An adhesive layer (20) is previously provided on the adhesive surface by coating an adhesive coating agent on the substrate (51) side of the film (e), and then a polyvinyl fluoride (PVF) solution is heated and dried by coating. The solar cell module back surface protective sheet (h) formed by forming a PVF layer (30).

  The back surface protection sheet (a, b, c, f, g, h) for the solar cell module of the present invention has special treatment such as frame treatment or plasma treatment on the laminated surface of the base material on which the polyvinyl fluoride (PVF) layer is formed. PVF layers can be formed without the need for surface treatment. Therefore, the cheap back surface protection sheet for solar cell modules which suppressed the raise of the manufacturing cost of a solar cell back surface protection sheet is obtained. In addition, it has excellent heat resistance, weather resistance, hydrolysis resistance, moisture resistance, light weight, and other properties that can withstand harsh natural environments over a long period of time, and a gas barrier that blocks the entry of water vapor and oxygen. In addition, there is no change in appearance in a high temperature / high humidity environment, and durability capable of maintaining power output characteristics as a solar cell over a long period of time.

  As the adhesive coating agent constituting the adhesive layer (20) in the present invention, an acrylic polyol-based coating agent or an aminoethylated acrylic coating agent is preferably used in the present invention.

  The acrylic polyol-based coating agent can be prepared by dissolving an adhesive composition containing a curing agent composed of an acrylic polyol and an isocyanate compound as main components in a solvent.

  The above acrylic polyol has two or more hydroxyl groups in the polymer and is obtained by copolymerizing a polyol obtained by polymerizing an acrylic acid derivative monomer or an acrylic acid derivative monomer and other monomers. Acrylic polyol, in particular, an acrylic acid derivative monomer such as ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyl butyl methacrylate or the like, or a copolymer obtained by adding another monomer such as styrene and having a hydroxyl value of 5 Examples include acrylic polyols in the range of ~ 200 (KOHmg / g).

  The isocyanate curing agent includes, for example, monomers such as aromatic tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), aliphatic xylene diisocyanate (XDI), hexadiisocyanate (HMDI), and the like. Examples thereof include isocyanate compounds composed of one or more of polymers and derivatives.

  Furthermore, in addition to the main components composed of the above acrylic polyol and isocyanate curing agent, for example, a chain extender such as cyclohexane-1,4-dimethanol and isophoronediamine can also be included.

  Examples of the acrylic polyol used in the above acrylic polyol-based coating agent include “LR209 (trade name, manufactured by Mitsubishi Rayon Co., Ltd.)” and the like, and “A56 (trade name, manufactured by Mitsui Takeda Chemical Co., Ltd.)” as the isocyanate curing agent. Are preferably used in the present invention.

  The aminoethylated acrylic coating agent can be prepared by dissolving an adhesive composition mainly composed of aminoethylated acrylic and an epoxy curing agent in a solvent.

  The above aminoethylated acrylic is obtained by subjecting a carboxyl-containing acrylic or methacrylic polymer to aminoethylation (amino reaction) with an excess amount of an alkyleneimine or N- (aminoalkyl) -substituted alkyleneimine in an appropriate solvent to convert the carboxyl group —COOH. Obtained by aminoethylation.

  The above epoxy curing agents include, as epoxy resins, tetraglycidyl ether type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, alicyclic epoxy resin, glycidyl ester type epoxy resin, glycidyl amine. Type epoxy resin, heterocyclic epoxy resin, urethane-modified epoxy resin, and the like. These may be used alone or in combination of two or more. Examples of the curing agent include amine-based curing agents, polyaminoamide-based curing agents, acids and acid anhydrides, dicyandiamide, organic acid dihydrazide, and other basic active hydrogen compounds, imidazoles, amine imides, Lewis acids, and Brons. Examples include Stead acid salts and phenol resins, and these can be used alone or in combination of two or more.

  As the aminoethylated acrylic, for example, “NK350 (trade name, manufactured by Nippon Shokubai Co., Ltd.)” and the like, and as an epoxy curing agent, “Epicoat 828 (trade name, manufactured by Yuka Shell Co., Ltd.)” and the like are used in the present invention. Preferably used.

  As the PVF solution constituting the polyvinyl fluoride (PVF) layer (30) in the present invention, PVF is generally insoluble in conventional solvents at room temperature, but is made into a solution using a so-called “latent solvent”. It is possible. The dispersion of PVF powder is suspended in a latent solvent and first heated to a first temperature at which a gel is formed and then heated to a higher second temperature at which a solution is formed. The “latent solvent” has a boiling point of 100 ° C. or higher (under atmospheric pressure), and the solvent or swelling action on PVF is not large at room temperature, but the PVF particles are not heated at a temperature lower than the boiling point. An organic liquid that can exhibit sufficient solvent action to be fused.

  Examples of latent solvents useful in the present invention include cyclic butadiene sulfolane, tetramethylene sulfolane, dimethyl sulfolane, hexamethylene sulfolane, diallyl sulfoxide, dimethyl sulfoxide, dicyanobutene, adiponitrile, ethylene in addition to γ-butyrolactone. Carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, isobutylene carbonate, trimethylene carbonate, N, N-diethylformamide, N, N-dimethylacetamide, N, N-dimethylformamide, N, N -Dimethyl-γ-hydroxyacetamide, N, N-dimethyl-γ-hydroxybutyramide, N, N-dimethyllactoamide, N, N-dimethylmethoxyacetamide, N-methyl Kutamide, N-methylformamide, N, N-dimethylaniline, N, N-dimethylethanolamine, 2-piperidone, N-methyl-2-piperidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, 5-methyl-2-pyrrolidone, β-propiolactone, δ-valerolactone, γ-valerolactone, α-angelicalactone, β-angelicalactone, ε-caprolactone, and γ-butyrolactone , Α-, β- and γ-substituted alkyl derivatives of γ-valarolactone and δ-valerolactone, as well as δ-substituted alkyl derivatives of δ-valerolactone, tetramethylurea, 1-nitropropane, 2-nitropropane, aceto Nylacetone, acetophenone, acetylacetone, cyclohexa , Diacetone alcohol, dibutyl ketone, isophorone, mesityl oxide, methyl amyl ketone, 3-methylcyclohexanone, bis (methoxymethyl) uron, methyl acetyl salicylate, diethyl phosphate, dimethyl phthalate, ethyl acetoacetate, methyl benzoate, methylene Examples thereof include diacetate, methyl salicylate, phenylacetic acid, triethyl phosphate, tris (morpholino) phosphine oxide, n-acetylmorpholine, N-acetylpiperidine, isoquinoline, quinoline, pyridine and tris (dimethylamino) phosphate.

  As a method for coating the PVF solution on the substrate, a conventionally known coating method such as a roll coating method, a gravure roll coating method, a coating method such as a kiss coating, a printing method, a spray method or a dipping method can be applied. And the thickness (dry state) of said polyvinyl fluoride layer has the preferable range of 20-300 micrometers.

  As the base material (10) used in the present invention, any base material such as a polyester film, an aluminum foil, a gas barrier film provided with a vapor deposition layer made of metallic aluminum or an inorganic compound is used.

  As the polyester film, for example, as an acid component, aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, aliphatic dicarboxylic acid such as adipic acid, sebacic acid, dodecadioic acid, azelaic acid, cyclohexanedicarboxylic, etc. As the alicyclic dicarboxylic acid and alcohol component, there may be used an aliphatic diol such as ethylene glycol, diethylene glycol and butanediol, and a polymer in which one or more of these acid components and alcohol components are combined. Moreover, the blended material which blended 2 or more types of such polymers can also be used. Among these, polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT), and polyethylene naphthalate ((PEN)) are preferable in terms of gas barrier properties and mechanical strength characteristics.

  Moreover, as said aluminum foil, the thickness of aluminum foil becomes like this. Preferably it is 5-50 micrometers, More preferably, it is 5-30 micrometers in thickness. The gas barrier property can be ensured in such a range. It is industrially difficult to produce an aluminum foil having a thickness of less than 5 μm, and even if it is possible, the number of pinholes exceeds 100 / square meter, which is inappropriate. The component of the aluminum foil may be a known component, and may be either pure aluminum or an aluminum-based alloy. Specifically, pure aluminum (JIS (AA) 1000 series, such as 1N30, 1N70, etc.), Al-Mn series (JIS (AA) 3000 series, such as 3003, 3004, etc.), Al-Mg series (JIS (AA)). 5000 series), Al-Fe series (JIS (AA) 8000 series, for example, 8021, 8079, etc.), and the like. Regarding components such as Fe, Si, Cu, Ni, Cr, Ti, Zr, Zn, Mn, Mg, and Ga contained in the aluminum-based material, as long as they are within the known content range defined by JIS and the like. There is no problem. Further, the aluminum foil may be any of a hard material, a semi-hard material, a soft material, etc., and may be appropriately selected.

  In addition, as a gas barrier film provided with a vapor deposition layer made of metallic aluminum or an inorganic compound, a transparent primer layer (52), a vapor deposition layer (53) made of an inorganic compound, and a composite coating are formed on at least one surface of a film substrate (51). It is preferable to sequentially laminate an overcoat layer (54) made of Hereinafter, this gas barrier film will be described in detail.

  Examples of the film substrate (51) include polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefin films such as polyethylene and polypropylene, polystyrene films, polyamide films, polycarbonate films, polyacrylonitrile films, and polyimides. A film or the like is used, which may be stretched or unstretched, and preferably has mechanical strength and dimensional stability.

The thickness of the film substrate is not particularly limited, but in consideration of workability when forming an overcoat layer composed of a primer layer, an inorganic oxide vapor-deposited thin film layer, and a composite film, it is practically It is preferable to set it as 6-30 micrometers according to a use in the range of 3-200 micrometers.

  The thickness of the film substrate is not particularly limited, but it is practical considering the workability when forming a transparent primer layer, a vapor deposition layer made of metallic aluminum or an inorganic compound, or an overcoat layer made of a composite coating layer. Specifically, a range of 3 to 200 μm is preferable, and a range of 6 to 30 μm is particularly preferable.

  Next, the transparent primer layer (52) will be described in detail. The purpose of this layer is to improve the adhesion between the film substrate (51) and the vapor deposition layer (53) made of metal aluminum or an inorganic compound.

  What can be used as resin of said transparent primer layer needs to be a composite of a silane coupling agent or its hydrolyzate, a polyol, an isocyanate compound, etc.

  As an example of the silane coupling agent, a silane coupling agent containing any organic functional group can be used, for example, ethyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyl. Use one or more of silane coupling agents such as trimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, or hydrolysates thereof. Can do.

  Further, among these silane coupling agents, those having a functional group that reacts with a hydroxyl group of a polyol or an isocyanate group of an isocyanate compound are particularly preferable. For example, those containing an isocyanate group such as γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, those containing a mercapto group such as γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane, Some include amino groups such as γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, and γ-phenylaminopropyltrimethoxysilane. Furthermore, those containing an epoxy group such as γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltrimethoxysilane, vinyl (β-methoxyethoxy) silane, etc. Such a silane coupling agent may be added with alcohol or the like and added with a hydroxyl group or the like, and one or more of these may be used. These silane coupling agents have a silane cup containing a functional group in which an organic functional group present at one end exhibits an interaction in a composite composed of a polyol and an isocyanic compound or reacts with a hydroxyl group of a polyol or an isocyanate group of an isocyanate compound. By using a ring agent, a stronger transparent primer layer is formed by providing a covalent bond, and the silanol group generated by hydrolysis of the alkoxy group at the other end is a metal in the inorganic compound or the activity of the surface of the inorganic compound It exhibits high adhesion with an inorganic compound by strong interaction with a high hydroxyl group and the like, and the desired physical properties can be obtained. Therefore, you may use what hydrolyzed the said silane coupling agent with the metal alkoxide. In addition, there is no problem even if the alkoxy group of the silane coupling agent is a chloro group, an acetoxy group, etc., and these alkoxy groups, chloro groups, acetoxy groups, etc. are hydrolyzed to form silanol groups. Can be used in this composite.

A polyol has two or more hydroxyl groups in a polymer and is reacted with an isocyanate group in an isocyanate compound added later. Among these, an acrylic polyol which is a polyol obtained by polymerizing an acrylic acid derivative monomer or a polyol obtained by copolymerizing an acrylic acid derivative monomer and other monomers is particularly preferable. Among these, those obtained by polymerizing acrylic acid derivative monomers such as ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxylbutyl methacrylate alone, and acrylic polyols obtained by copolymerizing with other monomers such as styrene are preferably used. In consideration of reactivity with the isocyanate compound, the hydroxyl value is preferably in the range of 5 to 200 (KOHmg / g).

  The blending ratio of the polyol and the silane coupling agent is preferably in the range of 1/1 to 1000/1 in terms of weight ratio, more preferably in the range of 2/1 to 100/1. The dissolving and diluting solvent is not particularly limited as long as it can be dissolved and diluted. For example, esters such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as methyl ethyl ketone, A mixture of aromatic hydrocarbons such as toluene and xylene alone and arbitrarily can be used. However, since an aqueous solution such as hydrochloric acid may be used to hydrolyze the silane coupling agent, it is preferable to use a solvent in which isopropyl alcohol or the like and ethyl acetate that is a polar solvent are arbitrarily mixed as a cosolvent.

Further, a reaction catalyst may be added in order to promote the reaction at the time of blending the silane coupling agent and the polyol. The catalyst to be added is a tin compound such as tin chloride (SnCl ₂ , SnCl ₄ ), tin oxychloride (SnOHCl, Sn (OH) ₂ Cl ₂ ), tin axoxide in terms of reactivity and polymerization stability. Is preferred. If the addition amount is too small or too large, the catalytic effect cannot be obtained, and therefore it is preferably in the range of 1/10 to 1/10000 in terms of molar ratio with respect to the trifunctional organosilane, more preferably 1 / 100 to 1/2000.

  The isocyanate compound to be mixed is added to increase the adhesion between the base material 1 and the vapor deposition layer by a urethane bond formed by reacting with a polyol, and mainly acts as a crosslinking agent or a curing agent. To achieve this, as isocyanate compounds, monomers such as aromatic tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), aliphatic xylene diisocyanate (XDI), and hexadiisocyanate (HMDI); These polymers and derivatives are used, and these can be used alone or in combination.

  The blending ratio of the polyol and the isocyanate compound is not particularly limited, but if the amount of the isocyanate compound is too small, curing may be poor, and if it is too much, blocking or the like occurs and there is a problem in processing. Therefore, the blending ratio of the polyol and the insocyanate compound is preferably that the NCO group derived from the isocyanate compound is 50 times or less of the OH group derived from the polyol, particularly preferably the NCO group and the OH group are blended in an equivalent amount. Is the case. As a mixing method, a known method can be used and is not particularly limited.

Furthermore, in order to improve the liquid stability during preparation of the above mixture, it is possible to add a metal alkoxide or a hydrolyzate thereof. The metal alkoxide, tetraethoxysilane _{(Si (OC 2 H 5)} 4), tripropoxy aluminum _{(Al (OC 3 H 7)} 3) and general formula M (OR) n (M: a metal element, R: CH ₃ or an alkyl group represented by a general formula C _n H _{2n + 1} such as C ₂ H _5, or a hydrolyzate thereof. Of these, tetraethoxysilane, tripropoxyaluminum, or a mixture of both is preferable because it is relatively stable in an aqueous solvent. The metal alkoxide hydrolyzate may be hydrolyzed together with the silane coupling agent, or may be added after adding an acid alone.

  The transparent primer layer is obtained by directly or previously hydrolyzing such a silane coupling agent or hydrolyzed together with a metal alkoxide (in this case, the above-mentioned reaction catalyst or the like may be added together) Is mixed with a polyol or an isocyanate compound to prepare a composite solution, or a silane coupling agent and a polyol are mixed in advance in a solvent (the above-described reaction catalyst and metal alkoxide may be added together). Among those that have undergone a hydrolysis reaction, or just a mixture of a silane coupling agent and a polyol (in this case, it is possible to add the above-mentioned reaction catalyst and metal alkoxide together) Then, an isocyanate compound is added to form a composite liquid and coated on a substrate.

  Various additives such as tertiary amines, imidazole derivatives, carboxylic acid metal salt compounds, quaternary ammonium salts, quaternary phosphonium salts and other curing accelerators, phenols, sulfurs, phosphites It is also possible to add an antioxidant, a leveling agent, a flow regulator, a catalyst, a crosslinking reaction accelerator, a filler and the like.

  Although the thickness of a transparent primer layer will not be specifically limited if a coating film can be formed uniformly, Generally it is preferable that it is the range of 0.001-2 micrometers. When the thickness is less than 0.01 μm, it is difficult to obtain a uniform coating film, and the adhesion may be lowered. On the other hand, when the thickness exceeds 2 μm, the coating film cannot be kept flexible because it is thick, and the coating film may be cracked due to external factors, which is not preferable. Particularly preferred is a range of 0.03 to 0.5 μm.

  As a method for forming the transparent primer layer, for example, a known printing method such as an offset printing method, a gravure printing method, a silk screen printing method, or a known coating method such as roll coating, knife edge coating, or gravure coating may be used. it can. About drying conditions, generally used conditions may be used. Further, in order to promote the reaction, it is possible to leave it in a high temperature aging chamber for several days.

  Next, metal aluminum and a vapor deposition layer (53) are demonstrated in detail. The vapor deposition layer made of an inorganic compound is a vapor deposition film of an inorganic compound such as aluminum oxide, silicon oxide, tin oxide, magnesium oxide, zinc oxide, or a mixture thereof, as long as it has a gas barrier property such as oxygen and water vapor. Good. In particular, it is more preferable to use aluminum oxide and silicon oxide. However, the material of the inorganic compound is not limited to the above-described inorganic compound, and any material that satisfies the above conditions can be used.

  The optimum conditions for the thickness of the metal aluminum or inorganic compound vapor deposition layer vary depending on the type and configuration of the inorganic compound used, but in general, the thickness is preferably in the range of 5 to 300 nm, and the value is appropriately selected. However, if the film thickness is less than 5 nm, a uniform film may not be obtained or the film thickness may not be sufficient, and the function as a gas barrier material may not be sufficiently achieved. Further, when the film thickness exceeds 300 nm, the thin film cannot be kept flexible, and there is a problem because the thin film may be cracked due to external factors such as bending and pulling after the film formation. More preferably, it exists in the range of 10-150 nm.

  There are various methods for forming a metal aluminum or inorganic compound layer on a film substrate, and it can be formed by a normal vacuum deposition method. In addition, other thin film forming methods such as sputtering, ion plating, and plasma vapor deposition (CVD) can also be used. However, considering productivity, the vacuum deposition method is the best at present. As a heating means of the vacuum evaporation method, it is preferable to use any one of an electron beam heating method, a resistance heating method, and an induction heating method, but the electron beam heating method should be used in consideration of the wide selection of evaporation materials. Is more preferable. Moreover, in order to improve the adhesiveness of an inorganic compound layer and a film base material, and the denseness of a vapor deposition layer, it is also possible to vapor-deposit using a plasma assist method or an ion beam assist method. Furthermore, in order to increase the transparency of the inorganic compound layer, it is possible to use reactive vapor deposition in which various gases such as oxygen are blown during vapor deposition.

  Next, the overcoat layer (54) made of a composite coating will be described. This composite coating layer is a coating layer having a gas barrier property, and is formed using a coating agent mainly composed of an aqueous solution or water / alcohol mixed solution containing a water-soluble polymer and one or more metal alkoxides or hydrolysates thereof. Is done. For example, a solution obtained by mixing a water-soluble polymer dissolved in an aqueous (water or water / alcohol mixed) solvent with a metal alkoxide directly or previously hydrolyzed is used as a solution. This solution is formed on the inorganic compound layer by heating and drying. Each component contained in the coating agent will be described in detail.

  Examples of the water-soluble polymer used in the coating agent for the composite coating layer include polyvinyl alcohol, polyvinyl pyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate and the like. In particular, when polyvinyl alcohol (hereinafter abbreviated as PVA) is used as the coating agent for the composite coating layer, it is preferable because the gas barrier property is most excellent. PVA here is generally obtained by saponifying polyvinyl acetate. As PVA, for example, complete PVA in which only several percent of acetic acid groups remain can be used from so-called partially saponified PVA in which several tens percent of acetic acid groups remain, and other types may be used. .

The metal alkoxide is a compound represented by a general formula, M (OR) _n (M: metal such as Si, Ti, Al, Zr, or alkyl group such as R: CH ₃ , C ₂ H ₅ ). Specific examples include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] and triisopropoxyaluminum [Al (O-2′-C ₃ H ₇ ) ₃ ], among which tetraethoxysilane and triisopropoxy. Aluminum is preferable because it is relatively stable in an aqueous solvent after hydrolysis.

  It is possible to add known additives such as isocyanate compounds, silane coupling agents, or dispersants, stabilizers, viscosity modifiers, and colorants to the solution as long as the gas barrier properties are not impaired. It is.

  As a method for applying the coating agent, conventionally known methods such as a dipping method, a roll coating method, a screen printing method, a spray method, and a gravure printing method that are usually used can be used.

  The thickness of the composite coating layer varies depending on the optimum conditions depending on the type of coating agent, the processing machine and the processing conditions, and is not particularly limited. However, when the thickness after drying is 0.01 μm or less, a uniform coating film cannot be obtained and sufficient gas barrier properties may not be obtained. On the other hand, if the thickness exceeds 50 μm, cracks are likely to occur in the film, which may be problematic. Preferably it exists in the range of 0.01-50 micrometers, More preferably, it exists in the range of 0.1-10 micrometers.

  The solar cell module back surface protective sheet of the present invention obtained above is an inexpensive solar that does not require special surface treatment such as frame treatment or plasma treatment on the adhesive surface of the base material constituting the solar cell back surface protection sheet. A back protection sheet for battery modules is obtained. In addition, it has excellent heat resistance, weather resistance, hydrolysis resistance, moisture resistance, light weight, and other properties that can withstand harsh natural environments over a long period of time, and a gas barrier that blocks the entry of water vapor and oxygen. In addition, there is no change in appearance in a high temperature / high humidity environment, and durability capable of maintaining power output characteristics as a solar cell over a long period of time.

  Next, the solar cell module which uses the back surface protection sheet for solar cells of this invention is demonstrated. 9-11 is sectional drawing which shows the layer structure of the one Example about the solar cell module which uses the back surface protection sheet for solar cells of this invention.

  For example, as shown in FIG. 9, the solar cell module of the present invention is provided with a surface protection sheet (63) for a solar cell module, a filler layer (61) on the surface side, and a wiring (62). A solar cell element (60) as a photovoltaic element, a back surface side filler layer (64), and a polyester film substrate (10) in which an adhesive layer (20) is previously provided on the adhesive surface by coating with an adhesive coating agent. ) And a back surface protective sheet (b) for a solar cell module obtained by forming a PVF layer (30) by heating and drying a polyvinyl fluoride (PVF) solution by coating. Further, if necessary, other materials are arbitrarily laminated between the respective layers, and then these are integrated by vacuum suction or the like, and a normal molding method such as a lamination method in which heat pressing is performed, and the above-described method is used. The solar cell module can be manufactured by thermocompression-bonding each layer as an integrally molded body and mounting the frame body (65).

  As a normal solar cell module surface protection sheet (63) constituting the solar cell module, it has sunlight permeability, insulation properties, and weather resistance, heat resistance, and light resistance. Properties such as water resistance, moisture resistance, antifouling properties, etc., excellent physical or chemical strength, toughness, etc., extremely durable, and solar as a photovoltaic device In order to protect the battery element, it is necessary to have excellent scratch resistance, shock absorption and the like. Specific examples of the surface protective sheet include known glass plates, and further, for example, polyamide resins (various nylons), polyester resins, cyclic polyolefin resins, polystyrene resins, (meth) Various resin films or sheets such as acrylic resin, polycarbonate resin, acetal resin, and the like can also be used. As the resin film or sheet, a biaxially stretched stretched film or sheet can be used. Further, the thickness of the resin film or sheet may be a minimum thickness necessary for maintaining strength, rigidity, waist, etc. If it is too thick, there is a disadvantage that the cost increases. On the contrary, if it is too thin, the strength, rigidity, waist and the like are lowered, which is not preferable. In the present invention, about 12 to 200 μm, more preferably about 25 to 150 μm is most desirable for the reasons described above.

  The filler layer (61) laminated under the surface protection sheet for the solar cell module constituting the solar cell module is transparent because sunlight is incident on it and transmits and absorbs it. In addition, it is also necessary to have adhesion to the surface protection sheet and the back surface protection sheet, and the surface smoothness of the solar cell element as a photovoltaic element is maintained. In order to fulfill this function, it is necessary to have thermoplasticity and to protect the solar cell element as a photovoltaic element, and therefore, it is necessary to have excellent scratch resistance, shock absorption and the like. Specifically, as the filler layer, for example, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid, or acid-modified polyolefin resin, polyvinyl butyral resin, silicone One type or a mixture of two or more types of resins such as epoxy resins, epoxy resins, (meth) acrylic resins, and the like can be used. In the present invention, in the resin constituting the filler layer, in order to improve weather resistance such as heat resistance, light resistance, water resistance, etc., in a range not impairing its transparency, for example, a crosslinking agent, Additives such as thermal antioxidants, light stabilizers, ultraviolet absorbers, photo-antioxidants, and others can be arbitrarily added and mixed. In the present invention, as the filler on the sunlight incident side, an ethylene-vinyl acetate-based resin is preferable in consideration of performance and price such as weather resistance such as light resistance, heat resistance, and water resistance. It is. In addition, as thickness of said filler layer, about 200-1000 micrometers, Preferably about 350-600 micrometers is desirable.

As a solar cell element (60) as a photovoltaic element constituting the solar cell module, a conventionally known one, for example, crystalline silicon such as a single crystal silicon type solar cell element or a polycrystalline silicon type solar cell element Solar electronic device, amorphous silicon solar cell device of single junction type or tandem structure type, III-V compound semiconductor solar electronic device such as gallium arsenide (GaAs) and indium phosphorus (InP), cadmium tellurium (CdTe) and copper II-VI group compound semiconductor solar electronic devices such as indium selenide (CuInSe ₂ ), organic solar cell devices, and the like can be used. Furthermore, a thin film polycrystalline silicon solar cell element, a thin film microcrystalline silicon solar cell element, a hybrid element of a thin film crystalline silicon solar cell element and an amorphous silicon solar cell element, or the like can also be used.

  As the filler layer (64) on the back surface side to be laminated under the photovoltaic element constituting the solar cell module, the surface side to be laminated under the surface protection sheet for the solar cell module. It is also necessary to have the same material as that of the filler layer and to have adhesiveness with the back surface protection sheet, and to maintain the smoothness of the back surface of the solar cell element as a photovoltaic element. Therefore, it is necessary to have excellent scratch resistance, shock absorption, and the like because it has thermoplasticity and also protects a solar cell element as a photovoltaic element.

  As the frame (65) constituting the solar cell module, an aluminum mold is generally used.

  FIG. 10 shows the layer structure of the solar cell module using the back surface protection sheet (a) for the solar cell module as one embodiment of the present invention.

  This solar cell module is pre-heated by coating a polyvinyl fluoride (PVF) solution on one side of a polyester film substrate (10) having an adhesive layer (20) provided on the adhesive surface by coating with an adhesive coating agent. The polyester film substrate (10) side of the back surface protection sheet for solar cell module (a) formed by drying to form a PVF layer (30) is laminated on the back surface side filler layer of the solar cell module, and polyfluorinated. This is a solar cell module in which the vinyl layer (30) is arranged to be the outermost layer on the back surface of the solar cell module.

  Further, FIG. 11 shows a layer structure of a solar cell module using the back surface protection sheet (f) for the solar cell module as one embodiment of the present invention.

  This solar cell module has an adhesive layer (adhesive layer (adhesive layer) coated on the adhesive surface in advance by coating an adhesive coating agent on the substrate (51) side of the gas barrier film (d) provided with a vapor deposition layer made of metallic aluminum or an inorganic compound. 20) and an overcoat made of a composite coating of a back surface protection sheet (f) for a solar cell module, on which a polyvinyl fluoride (PVF) solution is heated and dried by coating to form a PVF layer (30) This is a solar cell module in which the layer (54) side is laminated on the back side filler layer of the solar cell module, and the PVF layer (30) is disposed so as to be the outermost layer on the back side of the solar cell module.

  The solar cell module (i, j, k) of the present invention is inexpensive and does not require special surface treatment such as frame treatment or plasma treatment on the adhesive surface of the base material constituting the solar cell back surface protection sheet. Since the back surface protection sheet for solar cell modules is used, an inexpensive solar cell module can be obtained. In addition, it has excellent characteristics such as heat resistance, weather resistance, hydrolysis resistance, moisture resistance and light weight that can withstand harsh natural environments over a long period of time, and a gas barrier for blocking the ingress of water vapor and moisture In addition, there is no change in appearance in a high temperature / high humidity environment, and durability capable of maintaining power output characteristics as a solar cell over a long period of time. Furthermore, it is possible to maintain power output characteristics as a solar cell even under severe accelerated evaluation test conditions in a high temperature and high humidity environment.

  Hereinafter, the present invention will be specifically described with reference to examples of the present invention.

<Example 1>
An adhesive layer having a thickness of 2 to 3 μm (dried state) was previously formed on both surfaces of a 250 μm thick polyester film by a gravure coating method using an acrylic polyol-based coating agent having the following composition. First, a PVF dispersion in which polyvinyl fluoride (PVF) is dispersed in propyl alcohol and triethylamine is stirred on the adhesive layer on one side of the polyester film obtained above, and the viscosity is adjusted, and coating is performed at a temperature of 200 ° C. A PVF layer having a thickness of 25 μm was formed by heating and drying. Next, the other adhesive layer of the polyester film was coated using the same PVF solution as described above to form a PVF layer having a thickness of 25 μm in the same manner as described above. The back surface protection sheet for solar cell modules of this invention which consists of a structure of PVF layer / adhesion layer / polyester film / adhesion layer / PVF layer shown in FIG. 2 was produced.

[Composition of acrylic polyol coating agent]
(Weight ratio)
Acrylic polyol [LR209 (trade name, manufactured by Mitsubishi Rayon Co., Ltd.)] 1.6
・ Isocyanate curing agent [A56 (trade name, manufactured by Mitsui Takeda Chemical Company)] 2.0
・ Solvent (ethyl acetate) 140

<Example 2>
An adhesive layer having a thickness of 5 to 8 μm (dried state) was formed in advance on both surfaces of a 250 μm thick polyester film by a gravure coating method using an aminoethylated acrylic coating agent having the following composition. First, the polyvinyl fluoride (PVF) solution used in Example 1 was coated on the adhesive layer on one side of the polyester film obtained above, and a PVF layer having a thickness of 25 μm was formed in the same manner as in Example 1. . Next, a PVF layer having a thickness of 25 μm was formed on the other adhesive layer of the polyester film in the same manner as described above. The back surface protection sheet for solar cell modules of this invention which consists of a structure of PVF layer / adhesion layer / polyester film / adhesion layer / PVF layer shown in FIG. 2 was produced.

[Composition of aminoethylated acrylic coating agent]
(Weight ratio)
Aminoethylated acrylic [NK350 (trade name, manufactured by Nippon Shokubai Co., Ltd.)] 100
Epoxy curing agent [Epicoat 828 (trade name, manufactured by Yuka Shell)] 6
The composition was adjusted to a solid content of 25% by weight with a solvent toluene.

<Comparative Example 1>
As a comparative example for comparison with the back surface protection sheet for solar cell module of the present invention,
A PVF fill with a thickness of 25 μm was prepared from the same polyvinyl fluoride (PVF) solution as in Example 1 by a casting method, and 5 to 8 μm in a dry state using the following adhesive on both sides of a polyester film with a thickness of 250 μm. The PVF fill obtained above was bonded by a dry lamination method through an adhesive layer, and cured at 50 ° C. for 3 days to prepare a back protective sheet for a solar cell module.

(Weight ratio)
[Adhesive composition]
Polyester polyol [A511 (trade name, manufactured by Mitsui Takeda Chemical Co.)] 8
・ Isocyanate curing agent [A56 (trade name, manufactured by Mitsui Takeda Chemical)] 1
The composition was adjusted to a solid content of 30% by weight using the solvent ethyl acetate.

  About the back surface protection sheet for solar cell modules obtained above, the external appearance evaluation after a high temperature and high humidity test, peel strength, and comparative evaluation of the cost side were performed based on the following test method. The results are shown in Table 1.

[High temperature and high humidity test]
An environmental test was performed at a temperature of 85 ° C., a humidity of 85%, and 1000 hours.

[Measurement method of peel strength]
The back surface protection sheet for solar cell modules was cut to produce a 15 mm wide test piece, and the peel strength between the substrate and the polyvinyl fluoride (PVF) layer was measured using a tensile tester. The unit of peel strength is N / 15 mm.

  From Table 1, the back surface protective sheet for solar cell module of the present invention obtained in Examples 1 and 2 has no change in appearance such as “floating” after the high temperature / high humidity test, and is obtained in Comparative Example 1. Compared with the back surface protection sheet for solar cell modules, it is excellent in the adhesiveness of the polyvinyl fluoride (PVF) layer with respect to a base material. This effect is obtained by coating the polyvinyl fluoride (PVF) solution on one side or both sides of the base material in which the back surface protective sheet for solar cell module of the present invention has previously provided an adhesive layer on the adhesive surface by coating with an adhesive coating agent. This is because the PVF layer is formed by heating and drying. And since a PVF layer can be formed in the surface which forms the PVF layer of the base material which comprises the back surface protection sheet for solar cell modules, without requiring special surface treatments, such as a frame process and a plasma treatment, a solar cell back surface protection sheet An inexpensive back surface protection sheet for a solar cell module that suppresses an increase in the manufacturing cost of can be obtained.

  Moreover, the back surface protection sheet for solar cell modules of the present invention obtained in Examples 1 and 2 is provided with an adhesive layer made of an acrylic polyol-based coating agent or an aminoethylated acrylic coating agent, thereby providing an adhesive for dry lamination. This is advantageous in terms of manufacturing cost because it does not require curing of the adhesive layer.

  Furthermore, the back surface protection sheet for solar cell modules is excellent in various characteristics such as heat resistance, weather resistance, hydrolysis resistance, moisture resistance, and light weight, capable of withstanding a harsh natural environment for a long period of time, It also has a gas barrier property for blocking the entry of oxygen, has no change in appearance in a high temperature / high humidity environment, and has durability capable of maintaining power output characteristics as a solar cell over a long period of time.

It is sectional drawing which shows the layer structure of the one Example about the back surface protection sheet for solar cell modules of this invention. It is sectional drawing which shows the layer structure of the one Example about the back surface protection sheet for solar cell modules of this invention. It is sectional drawing which shows the layer structure of the one Example about the back surface protection sheet for solar cell modules of this invention. It is sectional drawing which shows the layer structure of the one Example about the gas-barrier film which provided the vapor deposition layer which consists of metal aluminum which comprises the back surface protection sheet for solar cell modules of this invention, and an inorganic compound. It is sectional drawing which shows the layer structure of the one Example about the gas-barrier film which provided the vapor deposition layer which consists of metal aluminum which comprises the back surface protection sheet for solar cell modules of this invention, and an inorganic compound. It is sectional drawing which shows the layer structure of the one Example about the back surface protection sheet for solar cell modules of this invention. It is sectional drawing which shows the layer structure of the one Example about the back surface protection sheet for solar cell modules of this invention. It is sectional drawing which shows the layer structure of the one Example about the back surface protection sheet for solar cell modules of this invention. It is sectional drawing which shows the layer structure of the one Example about the solar cell module using the back surface protection sheet for solar cell modules of this invention. It is sectional drawing which shows the layer structure of the one Example about the solar cell module using the back surface protection sheet for solar cell modules of this invention. It is sectional drawing which shows the layer structure of the one Example about the solar cell module using the back surface protection sheet for solar cell modules of this invention.

Explanation of symbols

a, b, c, f, g, h ... back surface protection sheet for solar cell module i, j, k ... solar cell module 10 ... polyester film substrate 20 ... adhesive layer 30 ... Polyvinyl fluoride (PVF) layer 40... Aluminum foil 50... Gas barrier film 51 provided with a vapor deposition layer made of metallic aluminum or an inorganic compound. Layer 54 ... Overcoat layer 60 ... Solar cell element 61 as a photovoltaic element ... Front-side filler layer 62 ... Wiring 63 ... Solar cell module surface protective sheet 64 ... Back surface Side filler layer 65 ... frame

Claims (13)

  It is characterized in that a polyvinyl fluoride layer is formed by heating and drying a polyvinyl fluoride solution by coating on one or both surfaces of a base material provided with an adhesive layer on the adhesive surface by coating with an adhesive coating agent in advance. Back surface protection sheet for solar cell modules.   The thickness of the said polyvinyl fluoride layer is the range of 20-300 micrometers, The back surface protection sheet for solar cell modules of Claim 1 characterized by the above-mentioned.   The said base material is a polyester film, The back surface protection sheet for solar cell modules of Claim 1 or 2 characterized by the above-mentioned.   The back protective sheet for a solar cell module according to claim 1 or 2, wherein the substrate is an aluminum foil.   The said base material is a gas-barrier film which provided the vapor deposition layer which consists of metallic aluminum or an inorganic compound, Comprising: This gas-barrier film is a base material which consists of 1 layer or more, The claim 1 or 2 characterized by the above-mentioned. Back surface protection sheet for solar cell modules.   The back protective sheet for a solar cell module according to claim 5, wherein the inorganic compound is aluminum oxide, silicon oxide, magnesium oxide, tin oxide, zinc oxide, or a mixture thereof.   A gas barrier film provided with a vapor deposition layer made of metal aluminum or an inorganic compound is formed by sequentially laminating a transparent primer layer, a vapor deposition layer made of metal aluminum or an inorganic compound, and an overcoat layer made of a composite film on a film substrate. The back surface protection sheet for solar cell modules according to claim 5 or 6.   The thickness of the said vapor deposition layer is the range of 5-300 nm, The back surface protection sheet for solar cell modules of any one of Claims 5-7 characterized by the above-mentioned.   The composite film constituting the overcoat layer is a composite film containing a hydroxyl group-containing polymer compound and a metal alkoxide and / or a hydrolyzate thereof and / or a polymer thereof. The back surface protection sheet for solar cell modules of any one of 5-8.   The back surface protective sheet for a solar cell module according to claim 9, wherein the hydroxyl group-containing polymer compound contains at least one of polyvinyl alcohol and poly (vinyl alcohol-co-ethylene).   The said metal alkoxide is a silane alkoxide and a silane coupling agent, The back surface protection sheet for solar cell modules of Claim 9 or 10 characterized by the above-mentioned.   The solar cell module using the back surface protection sheet for solar cell modules of any one of Claims 1-11. A solar cell module in which an adhesive coating agent is coated, and a polyvinyl fluoride layer is formed by coating a polyvinyl fluoride solution on one surface of a base material provided with an adhesive layer on an adhesive surface to be bonded in advance, followed by heating and drying. 13. The solar cell according to claim 12, wherein the back surface protective sheet for a solar cell module is provided with the back surface protective sheet for the solar cell module so that the polyvinyl fluoride layer is positioned on the outermost surface of the back surface of the solar cell module. module.

Images