JP2013080880A - Solar cell module back sheet and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module back sheet which can improve the adhesiveness to a filler layer by preventing air or the like from remaining on an adhesive surface to the filler layer, and also to provide a solar cell module using the solar cell module back sheet.SOLUTION: A solar cell module back sheet comprises: a front-side resin film arranged on the outermost surface: and a plurality of projections formed on the surface of the front-side resin film. Preferably, an arithmetic average roughness (Ra) on the surface of the front-side resin film in the solar cell module back sheet is within a range from 0.85 to 2.65 μm. A maximum valley depth (Rv) on the surface of the surface-side resin film in the solar cell module back sheet is preferably within a range from 10 to 40 μm. The surface-side resin film in the solar cell module back sheet preferably contains pigment in a dispersed manner.

Description

  The present invention relates to a solar cell module backsheet excellent in adhesiveness to a filler layer and a solar cell module using the same.

  In recent years, solar power generation as a clean energy source has attracted attention due to increasing awareness of environmental problems such as global warming, and solar cells having various forms have been developed. This solar battery is generally composed of a plurality of solar battery modules that are packaged by a plurality of solar battery cells wired in series or in parallel.

  Such a solar cell module is required to have sufficient durability and weather resistance that can be used outdoors for a long period of time. As shown in FIG. 5, as a specific structure of a general solar cell module 51, a transparent substrate 52 made of glass or the like, and a surface made of a thermoplastic resin such as ethylene vinyl acetate copolymer (EVA). A side filler layer 53, a plurality of solar cells 54 as photovoltaic elements, a back side filler layer 55 similar to the surface side filler layer 53, and a back sheet 56 for a solar cell module. They are stacked in order.

  As the solar cell module backsheet 56, a multilayer structure or the like in which a pair of synthetic resin layers 58 are laminated on the front and back surfaces of the gas barrier layer 57 is employed. As a specific conventional solar cell module backsheet 56, a structure in which a polyethylene terephthalate film is laminated on both surfaces of a resin film on which a metal oxide is deposited (see Japanese Patent Application Laid-Open No. 2002-1000078) is developed. Has been.

  Generally as a manufacturing method of this solar cell module, the translucent board | substrate 52, the surface side filler layer 53, the several sheets of photovoltaic cell 54, the back surface side filler layer 55, and the solar cell module backsheet 56 The vacuum heating lamination method etc. which superimpose and crimping | bonding, raising the degree of vacuum are employ | adopted.

  However, the conventional solar cell module back sheet 56 has a substantially flat surface on the surface side. Therefore, according to the conventional back sheet 56 for a solar cell module, when it is superimposed on the back surface side filler layer 55 and bonded by a vacuum heating lamination method or the like, a closed space is formed on the adhesive surface with the back surface side filler layer 55. There is a possibility that a path for removing the air existing in the closed space cannot be secured. Therefore, the solar cell module backsheet 56 has a disadvantage that air or the like remains in the closed space formed on the adhesion surface, thereby lowering the adhesiveness and reducing the durability and life of the solar cell module. Was holding.

Japanese Patent Laid-Open No. 2002-100788

  The present invention has been made in view of such circumstances, and a solar cell capable of preventing air and the like from remaining on the adhesive surface with the filler layer and improving the adhesion with the filler layer. The object is to provide a module backsheet and a solar cell module using the same.

The invention made to solve the above problems is
It is a solar cell module backsheet which is provided with the surface side resin film in the outermost surface, and has a some convex part on the surface of this surface side resin film.

  The solar cell module backsheet has a plurality of convex portions on the surface of the surface-side resin film. Thereby, when the back sheet for the solar cell module is bonded to the back surface side filler layer while increasing the degree of vacuum between the back surface side filler layer to be superimposed, Air or the like existing between them can be effectively removed from the path formed by the plurality of convex portions. As a result, the back sheet for the solar cell module can prevent air or the like from remaining on the adhesive surface with the back surface side filler layer in a state where the back sheet is adhered to the back surface side filler layer. Adhesiveness with the side filler layer can be improved.

  The solar cell module backsheet preferably has an arithmetic average roughness (Ra) of the surface-side resin film of 0.85 μm or more and 2.65 μm or less. Thus, by making the arithmetic mean roughness (Ra) of the surface side resin film surface within the above range, it is possible to effectively prevent the possibility of forming a closed space between the back surface side filler layer to be bonded. In addition, air and the like can be suitably removed.

  In the solar cell module backsheet, the maximum valley depth (Rv) of the surface-side resin film may be 10 μm or more and 40 μm or less. Thus, by making the maximum valley depth (Rv) of the surface side resin film surface within the above range, it is possible to effectively prevent the possibility of forming a closed space with the back side filler layer to be bonded. In addition, air and the like can be suitably removed.

  The solar cell module backsheet may have a ten-point average roughness (Rz) of 20 μm or more and 70 μm or less on the surface of the surface-side resin film. Thus, by setting the ten-point average roughness (Rz) of the surface-side resin film to the above range, it is possible to effectively prevent a closed space from being formed between the back-side filler layer to be bonded. And air and the like can be suitably removed.

  The solar cell module backsheet may have a 60 ° gloss of 50 to 80 on the surface of the surface-side resin film. Thus, by making glossiness into the above range, the convex shape of the surface side resin film surface is suitably maintained, air is suitably removed, and adhesion with the back side filler layer is improved. Can do.

  The solar cell module backsheet preferably contains a pigment dispersed in the surface-side resin film. Thus, by dispersing and containing the pigment in the surface side resin film, the heat resistance, thermal dimensional stability, weather resistance, strength, anti-aging, etc. of the surface side resin film and thus the back sheet for the solar cell module can be improved. Can be improved. In addition, the solar cell module backsheet has a function of reflecting light rays transmitted through the solar cells to the solar cell side by dispersing and containing a white pigment in the surface-side resin film disposed on the outermost surface side. Is added, and the power generation efficiency can be further increased.

  The back sheet for a solar cell module may contain a polyolefin resin as a main component of the surface-side resin film. Such a polyolefin resin is excellent in adhesiveness with an ethylene vinyl acetate copolymer (EVA) usually used for the back side filler layer, and has good hydrolysis resistance. As a result, the back sheet for a solar cell module can improve the durability of the solar cell module and can promote a prolonged use period of the solar cell module that is socially required.

  In the solar cell module backsheet, the polyolefin resin used as a material for forming the surface-side resin film is preferably polyethylene. Such polyethylene has high adhesiveness with an ethylene vinyl acetate copolymer (EVA) usually used for the back side filler layer of the solar cell module, and in addition, various functions such as hydrolysis resistance, heat resistance, and weather resistance. Good balance between price and price.

  The said solar cell module backsheet is good to provide a voltage endurance film and a back surface side resin film in this order on the back surface side of the said surface side resin film. As a result, the solar cell module backsheet can have a certain thickness, and the basic performance of the solar cell module backsheet, such as strength, weather resistance, heat resistance, etc., can be increased while the corresponding system voltage is reduced. Can be prevented. Moreover, the said solar cell module backsheet can improve the handleability by having fixed thickness. The “system voltage” means the voltage at the maximum output point under standard operating conditions in a solar cell system including a plurality of solar cell modules connected in series.

  The said solar cell module backsheet is good to provide a barrier film and a back surface side resin film in this order on the back surface side of the said surface side resin film. A solar cell module is usually used outdoors, and durability and weather resistance are required for its material and structure. In particular, for the solar cell module backsheet, the solar cell element may be weak against moisture, and it is important that the water vapor transmission rate is small as well as weather resistance, and it is preferable that the solar cell module has excellent barrier properties. The back sheet for solar cell module can improve the water vapor barrier property by having a barrier film, thereby improving the durability and weather resistance of the solar cell module and promoting the extension of the use period. it can.

  The said solar cell module backsheet is good to provide a voltage endurance film, a barrier film, and a back surface side resin film in this order on the back surface side of the said surface side resin film. The back sheet for a solar cell module has a barrier film, whereby the barrier property is improved, the durability and weather resistance of the solar cell module are improved, and the use period can be prolonged. In addition, the back sheet for the solar cell module has a voltage-resistant film, whereby the voltage resistance of the back sheet for the solar cell module is improved, and the solar cell system is controlled by controlling the thickness of the voltage-resistant film. It is possible to effectively cope with an increase in system voltage. Since the solar cell module backsheet includes a voltage-resistant film between the surface-side resin film and the barrier film, the solar cell has a high voltage resistance and a high system voltage solar cell system. Can correspond to modules.

Moreover, another invention made in order to solve the said subject is:
A solar cell module in which a translucent substrate, a front surface side filler layer, a solar battery cell as a photovoltaic element, a back surface side filler layer, and the back sheet for the solar cell module are laminated in this order. is there.

  The solar cell module has a plurality of convex portions on the surface of the surface-side resin film of the solar cell module backsheet. Thereby, when the solar cell module adheres the back sheet for solar cell module and the back side filler layer while increasing the degree of vacuum between the back sheet for solar cell module and the back side filler layer, Air or the like existing between the solar cell module backsheet and the back surface side filler layer can be effectively removed from the path formed by the plurality of convex portions. As a result, in the solar cell module, air or the like remains on the bonding surface between the solar cell module backsheet and the back surface side filler layer in a state where the back sheet for the solar cell module is bonded to the back surface side filler layer. Can be prevented, and as a result, the adhesion between the back sheet for the solar cell module and the back side filler layer can be improved.

  In the present invention, the “surface” means the light receiving surface side of the solar cell module and the back sheet for the solar cell module constituting the solar cell module. The “back surface” means a surface opposite to the light receiving surface side. The “arithmetic average roughness (Ra)”, “maximum valley depth (Rv)”, and “ten-point average roughness (Rz)” are values according to JIS B0601-2001. “Glossiness” is a value measured using “VG2000” manufactured by Nippon Denshoku Industries Co., Ltd.

  As described above, the solar cell module backsheet of the present invention can be adhered to the filler layer while effectively removing air and the like existing between the solar cell module and the filler layer. Therefore, the solar cell module backsheet of the present invention and the solar cell module using the backsheet can prevent air or the like from remaining on the adhesive surface between the solar cell module backsheet and the filler layer, and thus Adhesiveness between the solar cell module backsheet and the filler layer can be improved.

It is typical sectional drawing which shows the solar cell module backsheet which concerns on one Embodiment of this invention. It is typical sectional drawing which shows the solar cell module backsheet which concerns on the form different from the solar cell module backsheet of FIG. It is typical sectional drawing which shows the solar cell module backsheet which concerns on the form different from the solar cell module backsheet of FIG.1 and FIG.2. It is typical sectional drawing which shows the solar cell module using the solar cell module backsheet of FIG. It is typical sectional drawing which shows the conventional common solar cell module.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

  The back sheet 1 for a solar cell module in FIG. 1 includes a front-side resin film 2, a voltage-resistant film 3, and a back-side resin film 4 provided in this order from the front side to the back side through an adhesive layer 5. Is the body.

  The front surface side resin film 2 is a resin film that melts when the back sheet 1 for solar cell module and the back surface side filler layer (not shown) are thermocompression bonded. The surface side resin film 2 is formed with a synthetic resin as a main component. The synthetic resin as the main component of the surface-side resin film 2 is not particularly limited, and is a polyolefin resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin). , Polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, polyamideimide resin, polyarylphthalate resin, silicone resin, Examples include polysulfone resins, polyphenylene sulfide resins, polyether sulfone resins, polyurethane resins, acetal resins, and cellulose resins. Especially, as a synthetic resin of the main component of the surface side resin film 2, adhesiveness and hydrolysis resistance with the ethylene vinyl acetate copolymer (EVA) normally used for the back surface side filler layer of a solar cell module are shown. A good polyolefin resin is preferably used. The solar cell module backsheet 1 uses a polyolefin-based resin as a main component of the surface-side resin film 2, thereby improving the durability of the solar cell module, and the usage period of the solar cell module that is socially required. Can be prolonged.

  Examples of the polyolefin resin include polyethylene (for example, high density polyethylene, low density polyethylene, etc.), polypropylene, copolymers of olefins such as ethylene and other monomers, for example, copolymer of ethylene and unsaturated carboxylic acid ester. Copolymer (for example, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, etc.), copolymer of ethylene and unsaturated carboxylic acid (for example, ethylene-acrylic acid copolymer) For example, a copolymer, an ethylene-methacrylic acid copolymer, and the like) and an ionomer resin. Among these, the adhesion to the back side filler layer, the hydrolysis resistance, the heat resistance, the weather resistance, etc. for various functional aspects and the balance of the price, and the adhesiveness to the back side filler layer In addition, a cyclic polyolefin resin excellent in functionality such as heat resistance, strength, weather resistance, durability and gas barrier properties is preferred.

  Examples of the cyclic polyolefin resin include polymers obtained by polymerizing cyclic dienes such as cyclopentadiene (and derivatives thereof), dicyclopentadiene (and derivatives thereof), cyclohexadiene (and derivatives thereof), norbornadiene (and derivatives thereof), and the like. And a copolymer obtained by copolymerizing the cyclic diene and one or more olefinic monomers such as ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Among these cyclic polyolefin resins, cyclopentadiene (and derivatives thereof), dicyclopentadiene (and derivatives thereof) or norbornadiene (and derivatives thereof) such as polymers having excellent strength, heat resistance, and weather resistance are particularly preferred. preferable.

  In addition, as a forming material of the surface side resin film 2, the said synthetic resin can be used 1 type or in mixture of 2 or more types. Further, various additives and the like can be mixed in the forming material of the surface-side resin film 2 for the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, and the like. . Examples of the additive include a lubricant, a crosslinking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a reinforcing fiber, a reinforcing agent, an antistatic agent, a flame retardant, a flame retardant, a foaming agent, and an antifungal agent. And pigments. Moreover, the surface side resin film 2 may have a single layer structure or a multilayer structure of two or more layers.

  As a minimum of the thickness (average thickness) of the surface side resin film 2, 25 micrometers is preferable and 50 micrometers is especially preferable. On the other hand, the upper limit of the thickness (average thickness) of the surface-side resin film 2 is preferably 125 μm, and particularly preferably 100 μm. When the thickness of the surface-side resin film 2 is less than the lower limit, it becomes difficult to handle the solar cell module backsheet 1 when it is laminated, and coloring and functionality when a pigment is contained are not good. Inconvenience such as becoming sufficient occurs. Conversely, if the thickness of the surface-side resin film 2 exceeds the above upper limit, it will be contrary to the demand for thinner and lighter solar cell modules.

  A pigment may be dispersed and contained in the surface-side resin film 2. In this way, by dispersing and containing the pigment in the surface side resin film 2, the heat resistance, weather resistance, durability, thermal dimensional stability, strength, etc. of the surface side resin film 2 and thus the back sheet 1 for the solar cell module. These characteristics can be improved. Moreover, the function which reflects the light ray which permeate | transmitted the photovoltaic cell is added by disperse | distributing and containing a white pigment in the surface side resin film 2, and electric power generation efficiency can be improved more. Furthermore, the design property of a solar cell module can be improved by disperse | distributing black pigment etc. in the surface side resin film 2, and coloring the surface side resin film 2 in various colors.

  The white pigment is not particularly limited, and for example, calcium carbonate, titanium oxide, zinc oxide, lead carbonate, barium sulfate and the like can be used. Among these, calcium carbonate, which is excellent in dispersibility in the resin material forming the synthetic resin layer and has a relatively large effect of improving the durability, heat resistance, strength and the like of the synthetic resin layer, is preferable. This calcium carbonate has crystal types such as calcite, aragonite, and vaterite, and any crystal type can be used. This calcium carbonate may be surface-treated with stearic acid, sodium dodecyl benzene sulfonate, silane coupling agent, titanium coupling agent, etc., and impurities such as magnesium oxide, aluminum oxide, silicon dioxide, titanium dioxide, etc. About 10% or less may be contained. Other pigments include black pigments such as carbon black, blue pigments such as ultramarine and bitumen, red pigments such as red bean (iron oxide red), cadmium red, and molybdenum orange, and metal powder pigments that give metallic luster. This contributes to improving the design of the solar cell module.

  The average particle size of the pigment is preferably from 100 nm to 30 μm, particularly preferably from 300 nm to 3 μm. If the average particle diameter of the pigment is smaller than the lower limit, uniform dispersion in the film may be difficult due to aggregation or the like. On the other hand, when the average particle diameter of the pigment exceeds the above upper limit, the effect of improving various properties such as heat resistance to the surface-side resin film 2 may be reduced.

  The content of the pigment is preferably 8% by mass or more and 30% by mass or less. When the pigment content is less than the above lower limit, the effect of improving the durability, heat resistance, strength, etc. of the surface-side resin film 2 becomes small. On the other hand, when the content of the pigment exceeds the above upper limit, the dispersibility of the pigment in the film is lowered, and the strength of the surface-side resin film 2 may be lowered.

  The surface side resin film 2 has a surface 6 having a plurality of convex portions.

  The arithmetic average roughness (Ra) of the surface 6 is not particularly limited, but is preferably 0.85 μm or more and 2.65 μm or less, more preferably 1 μm or more and 2.5 μm or less, and particularly preferably 1.15 μm or more and 2.35 μm or less. preferable. When the arithmetic mean roughness (Ra) of the surface 6 exceeds the upper limit, the solar cell module backsheet 1 has a high possibility that air or the like remains between the backside filler layer to be bonded, This is considered to be because air or the like remains in the concave region formed on the surface 6 in the melting stage by a vacuum heating lamination method or the like. On the other hand, when the arithmetic average roughness (Ra) of the surface 6 is less than the lower limit, there is a high possibility that air or the like remains between the back-side filler layer to be bonded. It is thought that this is because a closed space is formed between the front surface 6 and the back surface side filler layer due to the flexibility of the sheet 1 and the like. On the other hand, when the arithmetic average roughness (Ra) of the surface 6 is within the above range, it is possible to effectively prevent the possibility that a closed space is formed with the back side filler layer to be bonded, such as air. Can be suitably removed.

  Although it does not specifically limit as the maximum valley depth (Rv) of the surface 6, For example, 10 micrometers or more and 40 micrometers or less are preferable, 15 micrometers or more and 35 micrometers or less are more preferable, and 20 micrometers or more and 30 micrometers or less are especially preferable. If the maximum valley depth (Rv) of the front surface 6 exceeds the upper limit, the solar cell module backsheet 1 has a high risk of air remaining between the back surface side filler layer to be bonded, This is considered to be because air or the like remains in the concave region formed on the surface 6 in the melting stage by a vacuum heating lamination method or the like. On the other hand, if the maximum valley depth (Rv) of the surface 6 is less than the lower limit, the solar cell module backsheet 1 has a high possibility that air or the like remains between the back surface side filler layer to be bonded. However, this is considered to be because a closed space is formed between the front surface 6 and the back surface side filler layer due to the flexibility and the like of the solar cell module backsheet 1. On the other hand, when the maximum valley depth (Rv) of the surface 6 is within the above range, it is possible to effectively prevent the possibility of forming a closed space between the back surface side filler layer to be bonded, air, etc. Can be suitably removed.

  The ten-point average roughness (Rz) of the surface 6 is not particularly limited, but is preferably 20 μm or more and 70 μm or less, more preferably 25 μm or more and 65 μm or less, and particularly preferably 30 μm or more and 60 μm or less. In the solar cell module backsheet 1, when the ten-point average roughness (Rz) of the surface 6 exceeds the upper limit, there is a high possibility that air or the like remains between the back-side filler layer to be bonded. This is considered to be because air or the like remains in the concave region formed on the surface 6 in the melting stage by a vacuum heating lamination method or the like. On the other hand, in the solar cell module backsheet 1, if the ten-point average roughness (Rz) of the surface 6 is less than the lower limit, air or the like may remain between the back-side filler layer to be bonded. Although it becomes high, it is thought that this is because a closed space is formed between the front surface 6 and the back surface side filler layer due to the flexibility of the back sheet 1 for the solar cell module. On the other hand, when the ten-point average roughness (Rz) of the surface 6 is within the above range, it is possible to effectively prevent the possibility of forming a closed space between the back surface side filler layer to be bonded and the air. Etc. can be suitably removed.

  Although it does not specifically limit as 60 degree glossiness of the surface 6 of the surface side resin film 2, For example, 50 or more and 80 or less are preferable, 55 or more and 75 or less are more preferable, and 60 or more and 70 or less are especially preferable. When the 60 ° glossiness of the surface 6 of the front surface side resin film 2 exceeds the upper limit, the solar cell module backsheet 1 has a high possibility that air or the like remains between the back surface side filler layer to be bonded. However, this is considered to be because air or the like remains in the concave region formed on the surface 6 in the melting stage by a vacuum heating lamination method or the like. On the other hand, when the 60 ° glossiness of the surface 6 of the surface-side resin film 2 is less than the lower limit, air or the like remains between the back-side filler layer to be bonded. This is considered to be due to the fact that a closed space is formed between the front surface 6 and the back side filler layer due to the flexibility of the solar cell module backsheet 1. On the other hand, in the solar cell module backsheet 1, when the 60 ° glossiness of the surface 6 of the surface-side resin film 2 is within the above range, the convex shape of the surface 6 of the surface-side resin film 2 is suitably maintained. Sagging and air can be suitably removed to improve the adhesion to the back side filler layer.

  Moreover, it is although it does not specifically limit as 20 degree glossiness of the surface 6 of the surface side resin film 2, For example, 40 or more and 70 or less are preferable, 45 or more and 65 or less are more preferable, and 50 or more and 60 or less are especially preferable. Although it does not specifically limit as 85 degree glossiness of the surface 6 of the surface side resin film 2, For example, 85-115 are preferable, 90-110 are more preferable, 95-105 are especially preferable. The back sheet 1 for a solar cell module has the surface-side resin film 2 and the back-side filler layer of the front-side resin film 2 and the back-side filler layer by adjusting the 20 ° glossiness and 85 ° glossiness of the surface 6 of the surface-side resin film 2 within the above range. The air or the like between them can be more suitably removed.

As a manufacturing method of the surface side resin film 2, if the thing of the said structure can be formed, it will not specifically limit, Various methods are employ | adopted. As a manufacturing method of the surface-side resin film 2, a method of forming a plurality of convex portions on the surface of the film after the film is formed, and a method of integrally forming the film and the plurality of convex portions are possible. In terms of
(A) A method of forming a surface-side resin film 2 by laminating a synthetic resin on a sheet mold having an inverted shape of the surface 6 and peeling the sheet mold;
(B) An injection molding method in which a molten resin is injected into a mold having an inverted shape of the surface 6;
(C) A method of transferring the shape by re-heating the filmed resin and pressing between the same mold and metal plate as described above,
(D) An extruded sheet molding method in which a molten resin is passed through a nip between a roll mold having a reverse shape of the surface 6 on the peripheral surface and another roll, and the shape is transferred.
Etc.

  In particular, according to the extrusion sheet molding method of (d), since the sheet formation and the formation of the plurality of convex portions can be performed integrally, the processing is easy and the substantially uniform surface 6 is easily formed. Can do. Moreover, as a roll type | mold which has a reverse shape in a surrounding surface, an embossing roll provided with a predetermined surface property can be used, and a rubber roll provided with a predetermined surface property can be used as another roll type | mold.

  The voltage-resistant film 3 is formed with a synthetic resin as a main component. The main component synthetic resin of the voltage-resistant film 3 is not particularly limited. For example, polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin). ), Acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin, polyamide resin, polyimide resin, polyamide Examples include imide resins, polyaryl phthalate resins, silicone resins, polysulfone resins, polyphenylene sulfide resins, polyether sulfone resins, polyurethane resins, acetal resins, and cellulose resins. Among the above resins, polyester resins, fluorine resins and cyclic polyolefin resins having high heat resistance, strength, weather resistance, durability, gas barrier properties against water vapor and the like are preferable.

  Examples of the polyester resin include polyethylene terephthalate and polyethylene naphthalate. Among these polyester-based resins, polyethylene terephthalate is particularly preferable because it has a good balance between various functions such as heat resistance and weather resistance, and price.

  Examples of the fluororesin include polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA) made of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, and a copolymer of tetrafluoroethylene and hexafluoropropylene (FEP). Copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether and hexafluoropropylene (EPE), copolymer of tetrafluoroethylene and ethylene or propylene (ETFE), polychlorotrifluoroethylene resin (PCTFE), ethylene and chlorotrifluoroethylene Copolymer (ECTFE), vinylidene fluoride resin (PVDF), vinyl fluoride resin (PVF), and the like. Among these fluororesins, polyvinyl fluoride resin (PVF) and a copolymer of tetrafluoroethylene and ethylene or propylene (ETFE) which are excellent in strength, heat resistance, weather resistance and the like are particularly preferable.

  In addition, as a forming material of the voltage-resistant film 3, the said synthetic resin can be used 1 type or in mixture of 2 or more types. The additives in the material for forming the voltage-resistant film 3 are the same as those for the surface-side resin film 2 described above. The voltage-resistant film 3 can be produced by a known method such as an extrusion method, a cast molding method, a T-die method, a cutting method, or an inflation method. The voltage-resistant film 3 may have a single layer structure or a multilayer structure of two or more layers.

  The thickness (average thickness) of the voltage-resistant film 3 is appropriately selected according to the voltage resistance required for the solar cell module backsheet 1. As a specific lower limit of the thickness of the voltage-resistant film 3, 50 μm is preferable, and 100 μm is particularly preferable. On the other hand, the upper limit of the thickness of the voltage-resistant film 3 is preferably 250 μm and particularly preferably 200 μm. There exists a possibility that the withstand voltage property of the said solar cell module backsheet 1 may not fully be improved as the thickness of the withstand voltage film 3 is less than the said minimum. On the other hand, when the thickness of the voltage-resistant film 3 exceeds the above upper limit, it is against the request for thinning and lightening the solar cell module.

  The back surface side resin film 4 is formed with a synthetic resin as a main component. As the main component synthetic resin of the back surface side resin film 4, the same resin as the voltage-resistant film 3 is used, but polyethylene terephthalate having a good balance of various functions such as heat resistance and weather resistance and price, Polyethylene naphthalate (PEN) which is excellent in hydrolysis resistance and heat resistance is preferred. In addition, about the molding method of the back surface side resin film 4, the additive in the forming material of the back surface side resin film 4, etc., it is the same as that of the voltage-resistant film 3.

  As a minimum of the thickness (average thickness) of the back side resin film 4, 12 micrometers is preferable and 25 micrometers is especially preferable. Moreover, as an upper limit of the thickness (average thickness) of the back surface side resin film 4, 250 micrometers is preferable and 188 micrometers is especially preferable. If the thickness of the back surface side resin film 4 is less than the above lower limit, the basic performance such as strength, weather resistance, heat resistance and the corresponding system voltage of the back sheet 1 for the solar cell module may be lowered. Inconveniences such as difficult handling of the resin film 4 occur. On the contrary, if the thickness of the back surface side resin film 4 exceeds the upper limit, it is contrary to the demand for thinning and lightening the solar cell module.

  The adhesive layer 5 is laminated between the superposed surface side resin film 2, voltage-resistant film 3, and back side resin film 4. Each film of the front surface side resin film 2, the voltage resistance film 3 and the back surface side resin film 4 is bonded and fixed by the adhesive layer 5, thereby the strength, durability, fastness, etc. of the back sheet 1 for the solar cell module. Will improve.

  As the adhesive constituting the adhesive layer 5, an adhesive for laminating or a melt-extruded resin is used. Examples of the laminating adhesive include dry laminating adhesive, wet laminating adhesive, hot melt laminating adhesive, non-solvent laminating adhesive, and the like. Among these laminating adhesives, dry laminating adhesives that are excellent in adhesive strength, durability, weather resistance and the like are particularly preferable.

  Examples of the dry laminate adhesive include polyvinyl acetate adhesive, homopolymers such as ethyl acrylate, butyl, 2-ethylhexyl ester, and copolymers of these with methyl methacrylate, acrylonitrile, styrene, and the like. Polyacrylic acid ester adhesive, cyanoacrylate adhesive, ethylene copolymer adhesive consisting of a copolymer of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, etc., cellulose adhesive Agent, polyester adhesive, polyamide adhesive, polyimide adhesive, urea resin, melamine resin amino resin adhesive, phenol resin adhesive, epoxy adhesive, polyurethane adhesive, reactive type ( (Meth) acrylic adhesive, chloroprene rubber, nitrile rubber, Styrene - butadiene made of rubber or the like rubber adhesive, a silicone-based adhesive, an alkali metal silicate, and the like inorganic adhesive made of a low-melting-point glass or the like. Among these adhesives for dry lamination, a decrease in adhesive strength and delamination caused by long-term outdoor use of the solar cell module backsheet 1 are prevented, and the adhesive layer 5 is further deteriorated such as yellowing. Reduced polyurethane adhesives, particularly polyester urethane adhesives are preferred. The curing agent is preferably an aliphatic polyisocyanate with little thermal yellowing.

  Examples of the melt-extruded resin include polyethylene resins, polypropylene resins, acid-modified polyethylene resins, acid-modified polypropylene resins, ethylene-acrylic acid or methacrylic acid copolymers, Surlyn resins, and ethylene-vinyl acetate copolymers. One or more thermoplastic resins such as polyvinyl acetate resin, ethylene-acrylic acid ester or methacrylic acid ester copolymer, polystyrene resin, and polyvinyl chloride resin can be used. In addition, when employ | adopting the extrusion laminating method using the said melt extrusion resin, in order to obtain stronger adhesive strength, it is good to give surface treatments, such as an anchor coat process mentioned later, to the lamination | stacking opposing surface of each said film.

The lower limit of the amount of lamination of the adhesive layer 5 (in terms of solid content), preferably ^{1g / m 2, 3g / m} 2 is particularly preferred. In contrast, the upper limit of the amount of lamination of the binding agent layer 5 (in terms of solid content), preferably 10 g / ^{m 2,} particularly preferably 7 g / ^{m 2.} If the amount of the adhesive layer 5 is less than the lower limit, sufficient adhesive strength may not be obtained. Moreover, when the amount of the adhesive layer 5 stacked exceeds the above upper limit, the stacking strength and durability may be reduced.

  In addition, in the adhesive for laminating or the melt-extruded resin forming the adhesive layer 5, for the purpose of improving and modifying the handling property, heat resistance, weather resistance, mechanical properties, etc., for example, a solvent, a lubricant, a crosslinking agent. Various additives such as antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing fibers, reinforcing agents, antistatic agents, flame retardants, flameproofing agents, foaming agents, antifungal agents, pigments, etc. can do.

  As a manufacturing method of the said solar cell module backsheet 1, generally, an adhesive is roll-coated to one of the lamination | stacking opposing surfaces of the surface side resin film 2, the voltage endurance film 3, and the back surface side resin film 4, Examples of the method include coating by means of a gravure roll coating method, a kiss coating method, and the like, and bonding the other laminated facing surface to the coating surface.

  The solar cell module backsheet 1 has a plurality of convex portions on the surface 6 of the surface-side resin film 2. Thereby, when the said solar cell module backsheet 1 adhere | attaches with this back surface side filler layer, raising the degree of vacuum between the back surface side filler layers superimposed, this back surface side filler layer and Can be effectively removed from the path formed by the plurality of convex portions. As a result, the solar cell module backsheet 1 can prevent air or the like from remaining on the adhesive surface with the back surface side filler layer while being adhered to the back surface side filler layer. Adhesiveness with the back side filler layer can be improved.

  The solar cell module backsheet 1 has a plurality of convex portions on the surface 6 of the surface-side resin film 2, thereby imparting slidability to the surface 6 of the solar cell module backsheet 1. As a result, the handling property of the solar cell module backsheet 1 can be improved.

  The solar cell module backsheet 1 is provided with a voltage-resistant film 3 and a backside resin film 4 in this order on the back side of the front surface side resin film 2, so that the backsheet 1 for solar cell module has a certain thickness. The basic system performance such as strength, weather resistance, and heat resistance of the solar cell module backsheet 1 can be improved, and the corresponding system voltage can be prevented from decreasing. Moreover, the said solar cell module backsheet 1 can improve handleability by having fixed thickness.

  The back sheet 11 for a solar cell module in FIG. 2 is a laminate including the front surface side resin film 2, the barrier film 12, and the back surface side resin film 4 in this order from the front surface side to the back surface side through the adhesive layer 5. It is. Since the front surface side resin film 2, the back surface side resin film 4, and the adhesive layer 5 are the same as the solar cell module backsheet 1 in FIG.

  The barrier film 12 has a base film 13 and an inorganic oxide layer 14 laminated on the back surface of the base film 13.

  The base film 13 is formed with a synthetic resin as a main component. As the synthetic resin as the main component of the base film 13, the same resin as the voltage-resistant film 3 is used, and in particular, polyethylene terephthalate having a good balance of various functions such as heat resistance and weather resistance and price. preferable. As a material for forming the base film 13, the above synthetic resins can be used alone or in combination of two or more. Further, the forming method of the base film 13 and the additives in the forming material of the base film 13 are the same as those of the voltage-resistant film 3.

  As a minimum of the thickness (average thickness) of substrate film 13, 7 micrometers is preferred and 10 micrometers is especially preferred. Moreover, as an upper limit of the thickness (average thickness) of the base film 13, 20 micrometers is preferable and 15 micrometers is especially preferable. When the thickness of the base film 13 is less than the above lower limit, inconveniences such as curl are likely to occur during vapor deposition for forming the inorganic oxide layer 14 and handling becomes difficult. . On the other hand, if the thickness of the base film 13 exceeds the above upper limit, it is contrary to the demand for thinning and lightening the solar cell module.

  The inorganic oxide layer 14 is a layer for expressing gas barrier properties against oxygen, water vapor, and the like, and is formed by depositing an inorganic oxide on the back surface of the base film 13. The vapor deposition means for forming the inorganic oxide layer 14 is not particularly limited as long as the inorganic oxide can be vapor deposited on the synthetic resin base film 13 without causing deterioration such as shrinkage and yellowing. a) Physical vapor deposition method (PVD method) such as vacuum deposition method, sputtering method, ion plating method, ion cluster beam method, (b) Plasma chemical vapor deposition method, thermal chemical vapor deposition method A chemical vapor deposition method (chemical vapor deposition method; CVD method) such as a chemical vapor deposition method or a photochemical vapor deposition method is employed. Among these vapor deposition methods, a vacuum vapor deposition method and an ion plating method that can form a high-quality inorganic oxide layer 14 with high productivity are preferable.

  The inorganic oxide constituting the inorganic oxide layer 14 is not particularly limited as long as it has gas barrier properties. For example, aluminum oxide, silica oxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, oxidation Magnesium or the like is used, and among these, aluminum oxide or silica oxide having a good balance between gas barrier properties and price is particularly preferable.

  The lower limit of the thickness (average thickness) of the inorganic oxide layer 14 is preferably 3 mm, and particularly preferably 400 mm. Moreover, as an upper limit of the thickness (average thickness) of the inorganic oxide layer 14, 3000 mm is preferable and 800 mm is particularly preferable. If the thickness of the inorganic oxide layer 14 is smaller than the lower limit, the gas barrier property may be lowered. On the other hand, if the thickness of the inorganic oxide layer 14 exceeds the above upper limit, the flexibility of the inorganic oxide layer 14 is reduced, and defects such as cracks are likely to occur.

  The inorganic oxide layer 14 may have a single layer structure or a multilayer structure of two or more layers. Thus, by making the inorganic oxide layer 14 into a multilayer structure, deterioration of the base film 13 is reduced by reducing the thermal burden applied during vapor deposition, and the adhesion between the base film 13 and the inorganic oxide layer 14 is further reduced. The sex etc. can be improved. The vapor deposition conditions in the physical vapor deposition method and the chemical vapor deposition method are appropriately designed according to the resin type of the base film 13 and the thickness of the inorganic oxide layer 14.

  Further, in order to improve the close adhesion between the base film 13 and the inorganic oxide layer 14, it is preferable to perform a surface treatment on the vapor deposition surface of the base film 13. Examples of such adhesion improving surface treatment include (a) corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, and the like ( b) Primer coat treatment, undercoat treatment, anchor coat treatment, vapor deposition anchor coat treatment and the like. Among these surface treatments, corona discharge treatment and anchor coat treatment that improve the adhesion strength with the inorganic oxide layer 14 and contribute to the formation of a dense and uniform inorganic oxide layer 14 are preferable.

  Examples of the anchor coating agent used for the anchor coating treatment include a polyester anchor coating agent, a polyamide anchor coating agent, a polyurethane anchor coating agent, an epoxy anchor coating agent, a phenol anchor coating agent, and a (meth) acrylic anchor coating. Agents, polyvinyl acetate anchor coating agents, polyolefin anchor coating agents such as polyethylene aly polypropylene, and cellulose anchor coating agents. Among these anchor coating agents, polyester anchor coating agents that can further improve the adhesive strength between the base film 13 and the inorganic oxide layer 14 are particularly preferable.

The lower limit of the coating amount of the anchor coating agent (solid content) is preferably ^{0.1g / m 2, 1g / m} 2 is particularly preferred. In contrast, the upper limit of the amount of coating of the anchor coating agent is preferably ^{5g / m 2, 3g / m} 2 is particularly preferred. If the coating amount of the anchor coating agent is smaller than the above lower limit, the effect of improving the adhesion between the base film 13 and the inorganic oxide layer 14 may be reduced. On the other hand, when the coating amount of the anchor coating agent exceeds the above upper limit, the strength, durability, etc. of the solar cell module backsheet 11 may be lowered.

  In the anchor coating agent, a silane coupling agent for improving tight adhesion, a blocking inhibitor for preventing blocking with the base film 13, an ultraviolet absorber for improving weather resistance, etc. These various additives can be appropriately mixed. The amount of the additive to be mixed is preferably 0.1% by weight or more and 10% by weight or less from the balance between the effect expression of the additive and the function inhibition of the anchor coating agent.

  Generally as a manufacturing process of the said solar cell module backsheet 11, (1) The barrier film manufacturing process which vapor-deposits an inorganic oxide on the back surface of the base film 13 by the said PVD method or CVD method, ( 2) Adhesive is coated on one of the laminated opposing surfaces of the front side resin film 2, the barrier film 12 and the back side resin film 4 by means of a roll coating method, a gravure roll coating method, a kiss coating method, etc. And a lamination step of bonding the other lamination facing surface.

  A solar cell module is usually used outdoors, and durability and weather resistance are required for its material and structure. In particular, for the solar cell module backsheet, the solar cell element may be weak against moisture, and it is important that the water vapor transmission rate is small as well as weather resistance, and it is preferable that the solar cell module has excellent barrier properties. The back sheet 11 for a solar cell module can improve the water vapor barrier property by having the barrier film 12, thereby improving the durability and weather resistance of the solar cell module and promoting the prolongation of the use period. be able to.

  The solar cell module backsheet 11 includes a barrier film 12 in which an inorganic oxide layer 14 is laminated on the back surface of a base film 13, thereby having a high gas barrier property, and a conventional sun using a metal foil. Compared with the back sheet for battery modules, mechanical strength, low cost, productivity and voltage resistance can be promoted.

  The back sheet 21 for a solar cell module in FIG. 3 includes a front surface side resin film 2, a voltage-resistant film 3, a barrier film 22, and a back surface side resin film 4 through the adhesive layer 5 from the front surface side to the back surface side. Are provided in this order. Since the front surface side resin film 2, the withstand voltage film 3, the back surface side resin film 4, and the adhesive layer 5 are the same as those of the solar cell module backsheet 1 in FIG.

  As the barrier film 22, an aluminum foil is used. Examples of the material of the aluminum foil include aluminum or an aluminum alloy, and an aluminum-iron alloy (soft material) is preferable. The iron content in this aluminum-iron alloy is preferably 0.3% or more and 9.0% or less, and particularly preferably 0.7% or more and 2.0% or less. If this iron content is less than the above lower limit, the effect of preventing the occurrence of pinholes may be insufficient, and conversely, if the iron content exceeds the above upper limit, flexibility is hindered and processed. May decrease. The aluminum foil material is preferably flexible aluminum that has been annealed from the viewpoint of preventing wrinkles and pinholes.

  As a minimum of the thickness (average thickness) of aluminum foil, 6 micrometers is preferred and 15 micrometers is especially preferred. Moreover, as an upper limit of the thickness (average thickness) of aluminum foil, 30 micrometers is preferable and 20 micrometers is especially preferable. If the thickness of the aluminum foil is smaller than the above lower limit, the aluminum foil is liable to break during processing, and the gas barrier property may be lowered due to pinholes or the like. On the other hand, if the thickness of the aluminum foil exceeds the above upper limit, cracks or the like may occur during processing, and the thickness and weight of the solar cell module backsheet 21 increase, resulting in a reduction in thickness and weight. It will be against the request.

  The surface of the aluminum foil may be subjected to surface treatment such as chromate treatment, phosphate treatment, and lubrication resin coating treatment from the viewpoint of preventing dissolution and corrosion, and coupling treatment from the viewpoint of promoting adhesion. Etc. may be given.

  The back sheet 21 for the solar cell module has the barrier film 22 so that the barrier property is improved, the durability and weather resistance of the solar cell module are improved, and the use period can be prolonged. In addition, the solar cell module backsheet 21 has the voltage-resistant film 3, whereby the voltage resistance of the solar cell module backsheet 21 is improved, and the solar cell module backsheet 21 is controlled by controlling the thickness of the voltage-resistant film. It is possible to effectively cope with an increase in the system voltage of the battery system. Since the solar cell module backsheet 21 includes the voltage-resistant film 3 between the surface-side resin film 2 and the barrier film 22, the solar cell system has high voltage resistance and a high system voltage. It can respond to the solar cell module for use.

  Since the solar cell module backsheet 21 uses an aluminum foil as the barrier film 22, the solar cell module backsheet 21 has a high gas barrier property against oxygen, water vapor, and the like, and promotes the longevity and use period of the solar cell module. be able to.

  The solar cell module 31 of FIG. 4 includes a translucent substrate 32, a front surface side filler layer 33, a plurality of solar cells 34, a back surface side filler layer 35, and the solar cell module backsheet 21. Are stacked in this order from the surface side. In FIG. 4, the adhesive surface between the back surface side filler layer 35 and the solar cell module backsheet 21 is illustrated as a flat surface. However, the shape of the adhesive surface can be appropriately changed depending on the shape of the surface 6. It is.

  The translucent substrate 32 is laminated on the outermost surface, and (a) has transparency and electric insulation against sunlight, (b) mechanical, chemical and physical strength, specifically Excellent weather resistance, heat resistance, durability, water resistance, gas barrier properties against water vapor, wind pressure resistance, chemical resistance, fastness, (c) high surface hardness and prevent accumulation of dirt and dust on the surface It is required to have excellent antifouling properties.

  As a material for forming the translucent substrate 32, glass and synthetic resin are used. Examples of the synthetic resin used for the translucent substrate 32 include polyethylene resin, polypropylene resin, cyclic polyolefin resin, fluorine resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile rubber. Butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin such as polyethylene terephthalate, polyethylene naphthalate, various nylons, etc. Polyamide resin, polyimide resin, polyamideimide resin, polyaryl phthalate resin, silicone resin, polyphenylene sulfide resin, polysulfone resin, acetal resin, polyethersulfone resin, polyurethane resin Fat, and cellulosic resins. Among these resins, fluorine resins, cyclic polyolefin resins, polycarbonate resins, poly (meth) acrylic resins, or polyester resins are particularly preferable.

  In the case of the translucent substrate 32 made of synthetic resin, (a) transparent vapor deposition of an inorganic oxide such as silicon oxide or aluminum oxide on one surface by the PVD method or the CVD method for the purpose of improving the gas barrier property or the like. (B) For the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, etc., for example, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, charging It is also possible to contain various additives such as an inhibitor, a light stabilizer, a filler, a reinforcing fiber, a reinforcing agent, a flame retardant, a flame retardant, a foaming agent, a fungicide, and a pigment.

  The thickness (average thickness) of the translucent substrate 32 is not particularly limited, and is appropriately selected according to the material to be used so as to have required strength, gas barrier properties, and the like. The thickness of the synthetic resin-made translucent substrate 32 is preferably 6 μm or more and 300 μm or less, and particularly preferably 9 μm or more and 150 μm or less. Further, the thickness of the glass translucent substrate 32 is generally about 3 mm.

  The front surface side filler layer 33 and the back surface side filler layer 35 are filled around the solar cells 34 between the translucent substrate 32 and the solar cell module backsheet 21, and (a) the translucent substrate 32. And it has adhesiveness with the back sheet 21 for solar cell modules, scratch resistance for protecting the solar cells 34, shock absorption, etc. In addition, the surface side filler layer 33 laminated | stacked on the surface of the photovoltaic cell 34 has transparency which permeate | transmits sunlight in addition to the said various functions. Moreover, the back surface of the back surface side filler layer 35 is formed as a fine uneven surface.

  Examples of the material for forming the front surface side filler layer 33 and the back surface side filler layer 35 include fluorine resin, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid or methacrylic acid copolymer, polyethylene resin, and polypropylene. Examples thereof include acid-modified polyorene fin resins, polyvinyl butyral resins, silicone resins, epoxy resins, and (meth) acrylic resins obtained by modifying polyolefin resins such as resins and polyethylene with unsaturated carboxylic acids such as acrylic acid. . Among these synthetic resins, fluorine resins, silicone resins, or ethylene-vinyl acetate resins that are excellent in weather resistance, heat resistance, gas barrier properties, and the like are preferable.

  Moreover, as a forming material of the surface side filler layer 33 and the back surface side filler layer 35, the thermoreversible crosslinkable olefin polymer composition shown by Unexamined-Japanese-Patent No. 2000-34376, specifically, (a) non-compliance. A modified olefin polymer modified with a saturated carboxylic acid anhydride and an unsaturated carboxylic acid ester, wherein the average number of bonds of carboxylic acid anhydride groups per molecule is 1 or more, and the modified olefin polymer A modified olefin polymer in which the ratio of the number of carboxylic acid ester groups to the number of carboxylic acid anhydride groups in the coalescence is 0.5 to 20; and (b) a hydroxyl group-containing polymer having an average number of hydroxyl groups per molecule of 1 or more. And those having a ratio of the number of hydroxyl groups in the component (b) to the number of carboxylic anhydride groups in the component (a) of from 0.1 to 5 are also used.

  The forming material for the front side filler layer 33 and the back side filler layer 35 is, for example, a crosslinking agent, a thermal antioxidant, a light stabilizer, an ultraviolet absorber for the purpose of improving weather resistance, heat resistance, gas barrier properties, and the like. Various additives such as an agent and a photo-antioxidant can be appropriately contained. The thickness (average thickness) of the front side filler layer 33 and the back side filler layer 35 is not particularly limited, but is preferably 200 μm or more and 1000 μm or less, and particularly preferably 350 μm or more and 600 μm or less.

The solar battery cell 34 is a photovoltaic element that converts light energy into electric energy, and is disposed between the front surface side filler layer 33 and the back surface side filler layer 35. The plurality of solar cells 34 are laid in substantially the same plane, and are wired in series or in parallel although not shown. As the solar cell 34, for example, a crystalline silicon solar electronic element such as a single crystal silicon type solar cell element or a polycrystalline silicon type solar cell element, an amorphous silicon solar cell element such as a single junction type or a tandem structure type, or gallium arsenide. Group 3 to 5 compound semiconductor solar electronic devices such as (GaAs) and indium phosphorus (InP), and Group 2 to 6 compound semiconductor solar electronic devices such as cadmium tellurium (CdTe) and copper indium selenide (CuInSe ₂ ) Etc., and those hybrid elements can also be used. In addition, the front surface side filler layer 33 or the back surface side filler layer 35 is filled between the plurality of solar cells 34 without any gap.

  Although it does not specifically limit as a manufacturing method of the solar cell module 31, Generally, (1) Translucent board | substrate 32, the surface side filler layer 33, several sheets of photovoltaic cell 34, back surface side filling A step of superimposing the agent layer 35 and the solar cell module backsheet 21 in this order; and (2) a lamination step of integrally forming them by a vacuum heating lamination method in which they are integrated by vacuum suction and thermocompression bonded. . In the manufacturing method of the solar cell module 31, for the purpose of adhesiveness between the respective layers, (a) applying a heat-melt adhesive, solvent-type adhesive, photo-curing adhesive, etc., (b) each lamination The opposing surface can be subjected to corona discharge treatment, ozone treatment, low temperature plasma treatment, glow discharge treatment, oxidation treatment, primer coating treatment, undercoat treatment, anchor coating treatment, and the like. According to the above vacuum heating lamination method, the solar cell module 31 is melted while the back surface side filling layer 35 and the front surface side resin film 2 are increased in degree of vacuum, and these molten resins are joined together to form the back surface. The side filler layer 35 and the surface side resin film 2 are adhered.

  In the solar cell module 31, the surface 6 of the surface-side resin film 2 of the solar cell module backsheet 21 has a plurality of convex portions. Thereby, the said solar cell module 31 raises this vacuum degree between the solar cell module backsheet 21 and the back surface side filler layer 35, and this solar cell module backsheet 21 and the back surface side filler layer 35. When bonding, air or the like existing between the solar cell module backsheet 21 and the fine uneven surface of the back-side filler layer 35 can be effectively removed from the path formed by the plurality of protrusions. it can. As a result, the solar cell module 31 has air on the bonding surface between the solar cell module backsheet 21 and the backside filler layer 35 in a state where the backsheet 21 for the solar cell module is bonded to the backside filler layer. Etc. can be prevented, and as a result, the adhesion between the solar cell module backsheet 21 and the back-side filler layer 35 can be improved.

  The solar cell module 31 can further promote durability and life due to high adhesiveness between the solar cell module backsheet 21 and the back surface side filler layer 35. Therefore, the solar cell module 31 can be suitably used for a roof-standing solar cell, a solar cell for a small electric device such as a wristwatch or a calculator.

  In addition, the back sheet | seat for solar cell modules and solar cell module of this invention can be implemented in the aspect which gave various change and improvement other than the said aspect. For example, the back sheet for the solar cell module includes other layers (synthetic resin layer, metal layer, inorganic oxide layer, etc.) in addition to the front side resin film, voltage-resistant film, barrier film, and back side resin film, A film may be laminated. Thus, by laminating other layers or films, various characteristics such as voltage resistance, gas barrier properties, weather resistance, durability, etc. can be remarkably improved. Moreover, the said solar cell module backsheet may be equipped with the barrier film, the voltage-resistant film, and the back surface side resin film in this order on the back surface side of the surface side resin film. In the solar cell module backsheet, the front-side resin film, the voltage-resistant film, the barrier film, and the back-side resin film may be directly laminated by means such as extrusion lamination without using an adhesive layer. Moreover, the said solar cell module backsheet can also be equipped with the barrier film in which the inorganic oxide layer was laminated | stacked on the surface of the base film. The shape of the plurality of convex portions provided on the surface of the surface-side resin film is not particularly limited, and may be, for example, a plurality of protrusions, a predetermined uneven shape portion, or a plurality of protrusions provided in a stripe shape. It may be a roof-like part or may be a combination of these.

  As described above, the solar cell module backsheet of the present invention and the solar cell module using the backsheet can improve the adhesiveness with the back surface side filler layer, such as a house roof-standing solar cell and a calculator. It is suitably used for solar cells for small electric devices.

DESCRIPTION OF SYMBOLS 1 Back sheet for solar cell modules 2 Surface side resin film 3 Voltage-resistant film 4 Back surface side resin film 5 Adhesive layer 6 Surface 11 Back sheet for solar cell modules 12 Barrier film 13 Base film 14 Inorganic oxide layer 21 Solar cell Module Back Sheet 22 Barrier Film 31 Solar Cell Module 32 Translucent Substrate 33 Front Side Filler Layer 34 Solar Cell 35 Back Side Filler Layer 51 Solar Cell Module 52 Translucent Substrate 53 Front Side Filler Layer 54 Sun Battery cell 55 Back side filler layer 56 Back sheet for solar cell module 57 Gas barrier layer 58 Synthetic resin layer

Claims (12)

  A solar cell module backsheet comprising a surface-side resin film on the outermost surface and having a plurality of convex portions on the surface of the surface-side resin film.   2. The back sheet for a solar cell module according to claim 1, wherein the surface-side resin film has an arithmetic average roughness (Ra) of 0.85 μm or more and 2.65 μm or less.   The back sheet for a solar cell module according to claim 1 or 2, wherein a maximum valley depth (Rv) of the surface-side resin film is 10 µm or more and 40 µm or less.   The back sheet for a solar cell module according to claim 1, wherein the surface-side resin film has a ten-point average roughness (Rz) of 20 μm or more and 70 μm or less.   The back sheet for a solar cell module according to any one of claims 1 to 4, wherein the surface side resin film has a 60 ° gloss of 50 or more and 80 or less.   The back sheet for a solar cell module according to any one of claims 1 to 5, wherein a pigment is dispersed and contained in the surface-side resin film.   The solar cell module backsheet according to any one of claims 1 to 6, wherein the surface-side resin film contains a polyolefin-based resin as a main component.   The back sheet for a solar cell module according to claim 7, wherein the polyolefin resin is polyethylene.   The back sheet for a solar cell module according to any one of claims 1 to 8, wherein a voltage-resistant film and a back side resin film are provided in this order on the back side of the front side resin film.   The back sheet for a solar cell module according to any one of claims 1 to 8, wherein a barrier film and a back side resin film are provided in this order on the back side of the front side resin film.   The back sheet for a solar cell module according to any one of claims 1 to 8, wherein a voltage-resistant film, a barrier film, and a back-side resin film are provided in this order on the back side of the front-side resin film.   The translucent board | substrate, the surface side filler layer, the photovoltaic cell as a photovoltaic element, a back surface side filler layer, and the solar cell module of any one of Claims 1-11. A solar cell module in which a back sheet is laminated in this order.

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