JP2011138874A - Laminate for solar cell module and solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell module that endures a long-time use, is light-weight, and has a superior conversion efficiency. <P>SOLUTION: A laminate for a solar cell module is such that an olefin-based resin is stacked on one surface of a transparent resin sheet containing an ultraviolet absorbent, wherein the transparent resin sheet is a (meta) acrylic resin sheet. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a laminate for a solar cell module and a solar cell module.

In recent years, with the growing awareness of the environment, there has been a shift in power generation methods from thermal power generation that relies on fossil fuels, which are finite resources, to solar power generation, which is clean energy, and various types of solar cell modules are currently being developed. Has been. As a surface protection member used for such a solar cell module, one using a glass plate is generally used. However, the glass plate used here has a thickness of 3 mm or more in order to maintain the strength as the protection member. Is needed. In order to supply electric power necessary for a general household from the solar cell module, an area of 20 m ² or more is required, and thus the weight of the glass plate reaches 100 kg or more. Moreover, when using a solar cell module in a general household, it is common to install on the roof which can utilize sunlight effectively. Therefore, when installing such heavy objects on the roof, there is a problem that construction for reinforcing the structure of the house is required, which may increase the installation cost.

  Further, in addition to the above-described good transparency, the surface protection member for a solar cell needs to have moisture resistance to prevent internal conductors and electrode rust caused by moisture or water permeation.

  Patent Document 1 proposes to use an acrylic resin plate as a surface protection member. The surface protective member can be significantly reduced in weight as compared with the glass plate, but it cannot be said that the moisture-proof property is sufficient, and there is a problem that long-term reliability is lacking.

  On the other hand, the olefin resin is excellent in moisture resistance, but is easily colored by ultraviolet irradiation. Therefore, when the olefin resin is exposed to sunlight for a long time as a surface protection member, the transparency decreases due to yellowing and the conversion efficiency is improved. descend. Therefore, there has been a demand for a surface protective resin sheet that has both light weight and good light transmittance and excellent moisture resistance.

JP 2003-180093 A

  An object of the present invention is to provide a solar cell module that can withstand long-term use, is lightweight and has excellent conversion efficiency, and provides a means for inexpensively manufacturing a surface protection member for realizing the solar cell module. There is.

  The present invention is a solar cell module laminate in which an olefin-based resin layer is laminated on one surface of a transparent resin sheet containing an ultraviolet absorber.

  According to the present invention, it is possible to provide a solar cell module that can withstand long-term use, is lightweight, and has excellent conversion efficiency.

  Details of the present invention will be described below.

  The laminate for a solar cell module of the present invention is obtained by laminating an olefin resin on one surface of a transparent resin sheet containing an ultraviolet absorber.

Transparency resin sheet The transparency resin sheet used by this invention is not specifically limited, A well-known thing can be used. Examples of such a transparent resin sheet include a polycarbonate resin sheet, a polyester resin sheet, a polystyrene resin sheet, and a poly (meth) acrylic resin sheet. These can be used alone or in combination. Among these, from the viewpoints of transparency and weather resistance, a polycarbonate resin sheet and a poly (meth) acrylic resin sheet are preferable. Furthermore, a poly (meth) acrylic resin sheet having better transmittance than glass is preferable from the viewpoint of conversion efficiency of the solar cell module.

  When the transparent resin sheet is a (meth) acrylic resin sheet, the resin sheet preferably contains a monofunctional (meth) acrylic monomer unit.

  Examples of the (meth) acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, (meth) Examples include (meth) acrylic acid esters other than methyl methacrylate such as benzyl acrylate, 2-ethylhexyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate. Here, “(meth) acrylic acid” means acrylic acid and / or methacrylic acid.

  Furthermore, in addition to the above, polyfunctional (meth) acrylic monomer units can be used. In this case, the (meth) acrylic resin sheet is composed of a polyfunctional (meth) acrylic monomer unit and a monofunctional (meth) acrylic monomer unit. The (meth) acrylic monomer unit is preferably 30 to 80% by mass, and the monofunctional (meth) acrylic monomer unit is preferably 20 to 70% by mass. When the polyfunctional (meth) acrylic monomer unit is 30% by mass or more, deformation of the resin sheet can be suppressed even when heated in the module manufacturing process, and when it is 80% by mass or less, the appearance of the resin sheet is produced. Tends to obtain a good resin sheet.

  The polyfunctional (meth) acrylic monomer used here is not particularly limited, and known ones can be used. Examples of such polyfunctional (meth) acrylic monomers include ethylene glycol dimethacrylate, ethylene glycol diacrylate, 1,3-propanediol dimethacrylate, 1,3-propanediol diacrylate, and 1,4- Butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 2-methyl-1,3-propanediol dimethacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, 2,2'-dimethyl-1,4- Butanediol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, pentaerythritol tetramethacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane Kisa methacrylate, ditrimethylolpropane hexaacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol hexaacrylate, dicyclopentadienyl methacrylate. These can be used alone or in combination.

Ultraviolet Absorber The transparent resin sheet contains an ultraviolet absorber. The ultraviolet absorber is not particularly limited, and known ones can be used. Examples of such an ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2,2 Benzophenone compounds such as '-dihydroxy-4-methoxybenzophenone and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2- (2'-hydroxy-5-methylphenyl) benzotriazole, 2- (2' Benzotriazole compounds such as -hydroxy-3 ', 5'-di-t-butylphenyl) benzotriazole and 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole It is done. These can be used alone or in combination. Especially, what absorbs a wavelength of 400 nm or less from a viewpoint of suppression of the conversion efficiency of a solar cell module or coloring of an olefin resin layer is preferable.

  The addition amount of the ultraviolet absorber is preferably 0.001 or more and 1 part by mass or less per 100 parts by mass of the transparent resin sheet. When the ultraviolet absorber is 0.001 part by mass or more, the weather resistance of the transparent resin sheet and the olefin-based resin layer is improved, and the transparency tends to be maintained even when exposed to sunlight for a long time. Moreover, when the ultraviolet absorber is 1 part by mass or less, light effective for power generation of the solar cell module can be efficiently transmitted, and power generation efficiency tends to be improved.

Production method of transparent resin sheet The production method of the transparent resin sheet is not particularly limited. For example, in the case of producing a (meth) acrylic resin sheet, a desired amount of polyfunctional (meta) is formed in a space formed by a pair of molds. ) A method of injecting a polymerizable mixture composed of an acrylate monomer and a monofunctional (meth) acrylate monomer and curing it by polymerization. For the polymerization of the polymerizable mixture, various known radical polymerization initiators and chain transfer agents can be used. Specific examples of the radical polymerization initiator include t-butyl peroxypivalate, t-hexyl peroxypivalate, t-butyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, and t-butylperoxide. Oxyisopropyl carbonate, t-hexylperoxyisopropyl monocarbonate, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2 2,2'-azobisisobutyronitrile and the like. These can be used alone or in combination. The addition amount of the radical polymerization initiator is preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the polymerizable mixture. When it is 0.001 part by mass or more, polymerization is promoted, and when it is 1 part by mass or less, the resulting transparent resin sheet tends to have an excellent appearance.

  Specific examples of the chain transfer agent include alkyl mercaptans, cyclohexadiene and derivatives thereof, terpenoid compounds and derivatives thereof, and the like. These can be used alone or in combination. The addition amount of alkyl mercaptan, cyclohexadiene and derivatives thereof, and terpenoid compounds and derivatives thereof is preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the polymerizable mixture. When it is 0.001 part by mass or more, the appearance of the transparent resin sheet is good, and when it is 1 part by mass or less, polymerization is promoted.

Olefin resin An olefin resin is laminated on one surface of the transparent resin sheet. The olefin-based resin is not particularly limited as long as it does not impair the sunlight transmittance, and a known resin can be used. As such an olefin resin, unsaturated hydrocarbons and derivatives thereof are used. Examples thereof include olefin resins composed only of unsaturated hydrocarbons such as polyethylene and polypropylene, and olefin resins composed of halogenated unsaturated hydrocarbons such as polyvinylidene chloride and polyvinylidene fluoride. These can be used alone or in combination. Among these, polyethylene, polyvinylidene chloride, and polyvinylidene fluoride are preferable from the viewpoint of moisture resistance and weather resistance.

  The thickness of the olefin resin layer is preferably 2 to 200 μm. When the thickness of the olefin resin layer is 2 μm or more, the moisture-proof effect is good, and when it is 200 μm or less, the transparency is good.

  Examples of the method for forming the olefin resin layer include a method in which an emulsion containing an olefin resin by solution polymerization or emulsion polymerization is applied on a transparent resin sheet and dried to form a thin film. Among these, a method using an emulsion is preferable from the viewpoint of handleability.

Cured film A cured film may be formed on at least one surface of the transparent resin sheet. In this case, the cured film is located between the transparent resin sheet and the polyolefin resin layer. If a cured film is formed between the transparent resin sheet and the polyolefin resin layer, the adhesion between the transparent resin sheet and the polyolefin resin layer becomes good, and even if used for a long time, The interface with the polyolefin resin layer does not peel off, and the conversion efficiency does not decrease. This is because, when peeling occurs, light incident on the solar cell module is reduced due to interface reflection.

  The composition, forming method and thickness of the cured film formed on the surface are not particularly limited, and a method of obtaining a cured film by applying an active energy ray-curable polymer raw material to the surface and irradiating active energy rays such as ultraviolet rays. A known method such as a method of applying a silicon-based or melamine-based thermosetting polymer raw material to the surface and heating to obtain a cured film can be used.

  When the active energy ray-curable polymer material is used, a polymerizable compound having at least two (meth) acryloyloxy groups in the molecule can be used. The mixture which added 0.1-10 mass parts of photoinitiators (a-2) with respect to 100 mass parts of polymeric compounds (a-1) which have at least 2 (meth) acryloyloxy group in the said molecule | numerator. The method of irradiating with ultraviolet rays after applying the mixture to the surface of the transparent resin sheet is preferred from the viewpoint of curing speed. The polymerizable compound (a-1) is a cross-linking reactive compound having at least two (meth) acryloyloxy groups in the molecule, and an ether bond, thioether bond, ester bond, amide bond, urethane in the molecule. Bonds and the like can be included. In addition, (meth) acryloyloxy means acryloyloxy or methacryloyloxy.

  The main examples of these compounds are esterified products obtained from 1 mol of polyhydric alcohol and 2 mol or more of (meth) acrylic acid or derivatives thereof; polyhydric alcohol and polyhydric carboxylic acid or anhydride thereof. And a linear esterified product having two or more (meth) acryloyloxy groups in one molecule, obtained from a product and (meth) acrylic acid or a derivative thereof.

  Examples of esters obtained from 1 mole of polyhydric alcohol and 2 moles or more of (meth) acrylic acid include di (meth) acrylates such as diethylene glycol di (meth) acrylate and triethylene glycol di (meth) acrylate. ) Acrylate; 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, glycerin tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol Rupenta (meth) acrylate, and the like.

  In a linear esterified product having two or more (meth) acryloyloxy groups in one molecule obtained from a polyhydric alcohol and a polycarboxylic acid or anhydride thereof and (meth) acrylic acid, Preferred combinations of polycarboxylic acid or anhydride thereof and (meth) acrylic acid include malonic acid / trimethylolethane / (meth) acrylic acid, malonic acid / trimethylolpropane / (meth) acrylic acid, succinic acid / Trimethylolethane / (meth) acrylic acid, succinic acid / trimethylolpropane / (meth) acrylic acid, adipic acid / trimethylolethane / (meth) acrylic acid, adipic acid / trimethylolpropane / (meth) acrylic acid, Glutaric acid / trimethylolethane / (meth) acrylic acid, glutaric acid / trimethylol group Pan / (meth) acrylic acid, sebacic acid / trimethylolethane / (meth) acrylic acid, sebacic acid / trimethylolpropane / (meth) acrylic acid, fumaric acid / trimethylolethane / (meth) acrylic acid, fumaric acid / Trimethylolpropane / (meth) acrylic acid, itaconic acid / trimethylolethane / (meth) acrylic acid, itaconic acid / trimethylolpropane / (meth) acrylic acid, maleic anhydride / trimethylolethane / (meth) acrylic acid, Mention may be made of maleic anhydride / trimethylolpropane / (meth) acrylic acid and the like.

  Other examples of the polymerizable compound (a-1) include polyisocyanates obtained by trimerization such as trimethylolpropane toluylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, and acrylic monomers having active hydrogen, such as 2 -Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-methoxypropyl (meth) acrylate, N-methylol (meth) acrylamide, etc. are reacted with 3 mol or more per mol. Urethane (meth) acrylate obtained; poly [(meth) acryloyloxyethylene] isocyanurate such as di (meth) acrylate or tri (meth) acrylate of tris (2-hydroxyethyl) isocyanuric acid; Acrylate; known urethane polyacrylate and the like.

  As these polymerizable compounds (a-1), one or more of the above compounds can be used.

  Photoinitiator (a-2) is not particularly limited, and specific examples include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, butyroin, toluoin, benzophenone, p-methoxybenzophenone, Carbonyl compounds such as 2,2-diethoxyacetophenone and α, α-dimethoxy-α-phenylacetophenone; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; 2,4,6-trimethylbenzoyldiphenylphosphine oxide And benzoyldiethoxyphosphine oxide.

  The addition amount of a photoinitiator (a-2) is 0.1-10 mass parts with respect to 100 mass parts of polymeric compounds (a-1). When it is 0.1 part by mass or more, the curability of the photocurable polymer material is improved, and when it is 10 parts by mass or less, the cured film tends not to be colored. One or more initiators can be used.

  A known additive can be added to the photocuring polymer raw material depending on the purpose. Examples of the additive include a surfactant, a leveling agent, a dye, a pigment, an antioxidant, an ultraviolet absorber, a stabilizer, a flame retardant, and a plasticizer. Although the addition amount of an additive can be suitably selected within the range in which the physical properties of the obtained cured film are not impaired, it is 10 per 100 parts by mass in total of the polymerizable compound (a-1) and the photoinitiator (a-2). It is preferable that it is below mass parts.

Method for producing transparent resin sheet having cured film The method for producing a transparent resin sheet having a cured film using an active energy ray-curable polymer raw material is not particularly limited. Can be mentioned. That is, a photocurable polymer material is applied to the inner surface of at least one of a pair of opposed molds, the applied photocurable polymer material is cured to form a cured film, and methacrylic polymerization is performed in the mold cavity. A method of obtaining a cured film by injecting a polymer and polymerizing the mixture and peeling off the mold. Alternatively, after a methacrylic polymerizable mixture is injected into the cavities of a pair of molds facing each other and polymerized, the mold is peeled off to obtain a transparent resin sheet, and then a photo-curing weight is applied to at least one surface of the resin sheet. A method may be used in which a combined raw material is applied and cured to form a cured film to obtain a transparent resin sheet. In addition, after applying an active energy ray-curable polymer to the surface of the transparent resin sheet by a known method such as spin coating, die coating, dip coating, bar coating, flow coating, roll coating, gravure coating, etc., irradiation with active energy rays is performed. Then, a method of forming a cured film may be used.

  The method of forming a cured film when using a thermosetting polymer raw material is phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino argide resin, Using a thermosetting composition containing melamine-urea co-condensation resin, silicon resin, polysiloxane resin, cellulose acetate propionate, etc., applying the thermosetting composition to the surface of the transparent resin sheet, and then heating it. A method of forming a cured film can be used. The method for applying the thermosetting composition to the surface of the transparent resin sheet is not particularly limited, but a known method such as spin coating, die coating, dip coating, bar coating, flow coating, roll coating, gravure coating, etc. should be used. I can do it.

Solar cell module The solar cell module of the present invention may have a configuration in which the transparent resin sheet, the filler, the photovoltaic element, the filler, and the back surface protective film are stacked in this order from the sunlight incident side. . In this case, it is preferable that the olefin resin layer formed on one side of the transparent resin sheet is laminated on the filler side. The olefin resin layer formed on one side of the transparent resin sheet is laminated on the filler side, so that the sunlight incident on the solar cell module is absorbed by the ultraviolet absorber in the transparent resin sheet, and the olefin resin layer Therefore, the olefin-based resin layer is not colored and the power generation efficiency of the solar cell module does not decrease. Moreover, since the olefin-based resin layer is located outside the photovoltaic element, it can hinder the arrival of moisture or the like entering the photovoltaic element from the transparent resin sheet. In addition, the solar cell element, the conductive wire, the electrode and the like are not deteriorated.

Claims (6)

  A laminate for a solar cell module in which an olefin-based resin is laminated on one surface of a transparent resin sheet containing an ultraviolet absorber.   The laminate for a solar cell module according to claim 1, wherein the transparent resin sheet is a (meth) acrylic resin sheet.   The laminated body for solar cell modules of Claim 1 or 2 in which transparent resin contains a polyfunctional (meth) acrylic-type monomer unit.   The laminate for a solar cell module according to claim 1, wherein the transparent resin is a polycarbonate resin.   The laminated body for solar cell modules of any one of Claims 1-4 in which an olefin resin has a polyvinylidene chloride monomer unit.   In the solar cell module laminated | stacked in order of the laminated body for solar cell modules of any one of Claims 1-5 from the sunlight incident side, a sealing material, an optical semiconductor, a sealing material, and a barrier film, A solar cell module in which an olefin-based resin layer laminated on one surface of the laminate for a solar cell module is laminated on the sealing material side.