JP2015073048A - Solar cell protective sheet, and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell protective sheet excellent in durability having a protective layer containing fluororesin and (meta)acrylic resin, and an adhesive sealing layer containing polyolefin resin, in which adhesiveness between the protective layer and adhesive sealing layer is high, and to provide a solar cell module in which a solar cell element is protected by the solar cell protective sheet.SOLUTION: In a solar cell protective sheet B obtained by laminating a protective layer 1 containing fluororesin and (meta)acrylic resin, and an adhesive sealing layer 2 containing polyolefin resin, the (meta)acrylic resin is a copolymer having a copolymer component having one kind of functional group selected among carboxylic group, acid anhydride group, hydroxyl, and amido group, and the polyolefin resin has an epoxy group.

Description

  The present invention has a protective layer containing a fluororesin and a (meth) acrylic resin, and an adhesive sealing layer containing a polyolefin resin, and has high adhesion between the protective layer and the adhesive sealing layer. It is related with the solar cell protection sheet excellent in durability, and the solar cell module by which the solar cell element was protected by this solar cell protection sheet.

  As a solar cell, a rigid solar cell module based on glass and a flexible solar cell module based on a polyimide or polyester heat-resistant polymer material or a stainless thin film are known. In recent years, flexible solar cell modules have been attracting attention because of their ease of transportation and construction due to reduction in thickness and weight, and resistance to impact.

  Such a solar cell module has an upper and lower surface of a solar cell element in which a photoelectric conversion layer made of a silicon semiconductor or a compound semiconductor having a function of generating a current when irradiated with light is laminated on a base material in a thin film shape. These are sealed with an adhesive sealing layer, and have a protective layer as the outermost layer.

  For the adhesive sealing layer for sealing the solar cell element, ethylene-vinyl acetate copolymer, ethylene- (meth) methyl acrylate copolymer, ethylene- (meth) acrylic acid copolymer, polyvinyl butyral, etc. It is the mainstream to use a polyolefin-based resin (for example, Patent Document 1). On the other hand, fluorine resins such as polyvinylidene fluoride (PVDF) have been used for the protective layer because of excellent weather resistance (for example, Patent Document 2). Patent Document 3 discloses a solar cell surface protective sheet having a protective layer having a layer made of polyvinylidene fluoride and an acrylic resin alloy.

  However, the adhesion between the adhesive sealing layer containing the polyolefin resin and the protective layer containing the vinylidene fluoride resin or (meth) acrylic resin was low. Therefore, when the solar cell module is left in the environment for a long time, the protective layer may be peeled off from the adhesive sealing layer. As a result, the exposed surface of the adhesive sealing layer is whitened to reduce the amount of received light of the solar cell, or the solar cell element is deteriorated due to damage of the adhesive sealing layer, resulting in a decrease in power generation efficiency. It was.

JP 7-297439 A International Publication No. 2008/019229 Pamphlet JP 2011-129672 A

  The present invention has a protective layer containing a fluororesin and a (meth) acrylic resin and an adhesive sealing layer containing a polyolefin resin, and the adhesion between the protective layer and the adhesive sealing layer is enhanced. And it aims at providing the solar cell protection sheet excellent in durability, and the solar cell module by which the solar cell element was protected by this solar cell protection sheet.

  A first invention of the present application is a solar cell protective sheet in which a protective layer containing a fluorine resin and a (meth) acrylic resin and an adhesive sealing layer containing a polyolefin resin are laminated, The (meth) acrylic resin is a copolymer having a copolymer component having one kind of functional group selected from a carboxyl group, an acid anhydride group, a hydroxyl group, and an amide group, and the polyolefin resin has an epoxy group. It has a solar cell protective sheet.

  A second invention of the present application is a solar cell protective sheet in which a protective layer containing a fluororesin and a (meth) acrylic resin and an adhesive sealing layer containing a polyolefin resin are laminated, The (meth) acrylic resin is a copolymer having a copolymer component having one kind of functional group selected from an epoxy group, an amide group, and a hydroxyl group, and the polyolefin resin has a carboxyl group or an acid anhydride group. The solar cell protective sheet.

  A solar cell module according to the present invention includes a solar cell element having a base material, a photoelectric conversion layer disposed on the base material, and a solar cell laminated on the solar cell element and configured according to the present invention. It is a solar cell module provided with a protection sheet.

  The present invention is described in detail below.

  As a result of intensive studies, the inventors of the present invention have provided a solar cell protective sheet in which a protective layer containing a fluororesin and a (meth) acrylic resin and an adhesive sealing layer containing a polyolefin resin are laminated ( Adhesion between the protective layer and the adhesive sealing layer by introducing a specific functional group into the (meth) acrylic resin and the polyolefin resin and generating a strong chemical bond at the interface between the protective layer and the adhesive sealing layer. And the present invention was completed by finding that a solar cell protective sheet having high durability and excellent durability can be obtained.

  In the present invention, the protective layer is reactive to the protective layer by mixing a fluorine-based resin having excellent weather resistance with a (meth) acrylic resin having a specific functional group that reacts with the adhesive sealing layer. Is given. The adhesive sealing layer of the present invention is a polyolefin resin having a specific functional group that reacts with the protective layer.

  The solar cell protective sheet of the present invention has a structure in which a protective layer and an adhesive sealing layer are laminated. In FIG. 1, an example of the solar cell protection sheet of this invention is shown with typical sectional drawing. The solar cell protective sheet B has a protective layer 1 and an adhesive sealing layer 2. The said protective layer becomes an outermost layer in the solar cell module obtained when protecting a solar cell element using the solar cell protection sheet of this invention. The protective layer has a role of preventing external impact and preventing corrosion of the solar cell element.

  The protective layer contains a fluorine-based resin and a (meth) acrylic resin. The fluororesin is not particularly limited as long as it does not undergo phase separation even when mixed with a (meth) acrylic resin. As the fluorine resin, a vinylidene fluoride resin is preferable. In that case, transparency and strength are less likely to occur.

  In the present specification, the fluorine resin is a fluorine homopolymer or a copolymer containing 60 wt% or more of a fluorine monomer. Examples of the copolymer component include hexafluoropropylene, tetrafluoroethylene, vinyl fluoride, and ethylene.

  In the first invention of the present application, the (meth) acrylic resin is (meth) such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, or 2-ethylhexyl (meth) acrylate. A copolymer containing at least one acrylic ester monomer and a monomer having one functional group selected from a carboxyl group, an acid anhydride group, a hydroxyl group, and an amide group.

  In the second invention of the present application, the (meth) acrylic resin means (meth) acrylic acid methyl, (meth) acrylic acid ethyl, (meth) acrylic acid butyl, (meth) acrylic acid 2-ethylhexyl ( It is a copolymer containing at least one kind of (meth) acrylic acid ester monomer and a monomer having one kind of functional group selected from an epoxy group, a hydroxyl group and an amide group.

  Examples of the monomer having a carboxyl group in the first invention of the present application include (meth) acrylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid and the like, and one or more of these are used. In the first invention of the present application, examples of the monomer having an acid anhydride group include maleic anhydride and citraconic anhydride, and one or more of these are used.

  As the monomer having an epoxy group in the second invention of the present application, glycidyl (meth) acrylate, 2- (3,4-epoxycyclohexyl) ethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether One or more of these are used.

  Examples of the monomer having a hydroxyl group in the first invention and the second invention of the present application include 2-hydroxyethyl (meth) acrylate, and one or more of these are used.

  In the first and second inventions of the present application, examples of the monomer having an amide group include (meth) acrylamide, dimethyl (meth) acrylamide and the like, and one or more of these are used.

  As said functional group, it is preferable to use a kind of functional group and not to use two or more kinds of functional groups in combination. This is because if different types of functional groups are present in the (meth) acrylic resin, a crosslinking reaction may occur in the (meth) acrylic resin, and a gel may be generated. Two or more types of monomers may be used as long as they have the same type of functional group.

  The (meth) acrylic resin may be a copolymer containing a monomer component other than the (meth) acrylic acid ester monomer. Examples of the other monomer component include monomers having no reactivity with the functional group, such as ethylene, propylene, styrene, and butadiene.

  When the (meth) acrylic resin is a copolymer containing another monomer component, the content of the component derived from the (meth) acrylic acid ester monomer in the copolymer is 40% by weight or more. Preferably there is. When the content of the component derived from the (meth) acrylic acid ester monomer is less than 40% by weight, the effect of improving the adhesiveness with the adhesive sealing layer may be insufficient. The (meth) acrylic resin may be a mixture of the above (meth) acrylic resin and PMMA homopolymer.

  The amount of the functional group in the (meth) acrylic resin is preferably 0.001 to 2 mmol / g. If the amount of the functional group in the (meth) acrylic resin is within the above preferable range, the adhesion between the protective layer and the adhesive sealing layer can be further enhanced, and the transparency and strength are further reduced. Less likely to occur.

  The said protective layer may contain conventionally well-known additives, such as a light stabilizer, a ultraviolet absorber, a heat stabilizer, a plasticizer, in the range which does not impair the physical property.

  The preferable lower limit of the thickness of the protective layer is 10 μm, and the preferable upper limit is 150 μm. If the thickness of the protective layer is less than 10 μm, insulation may not be ensured or flame retardancy may be impaired. If the thickness of the protective layer exceeds 150 μm, the weight of the solar cell module may be increased, which is economically disadvantageous. The minimum with more preferable thickness of the said protective layer is 15 micrometers, and a more preferable upper limit is 100 micrometers.

  The said adhesive sealing layer has a role which adhere | attaches a solar cell element and a protective layer, and seals a solar cell element. The adhesive sealing layer contains a polyolefin-based resin and has an epoxy group, a carboxyl group or an acid anhydride group depending on the functional group contained in the protective layer.

  In the present specification, the polyolefin-based resin having an epoxy group, a carboxyl group or an acid anhydride group is a copolymer of an olefin containing ethylene, vinyl acetate or the like and a monomer having an epoxy group, a carboxyl group or an acid anhydride group. It is.

  In the first invention of the present application, as the monomer having an epoxy group, glycidyl (meth) acrylate, 2- (3,4-epoxycyclohexyl) ethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether One or more of these are used.

  Examples of the monomer having a carboxyl group in the second invention of the present application include (meth) acrylic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, and the like, and one or more of these are used.

  In the second invention of the present application, examples of the monomer having an acid anhydride group include maleic anhydride and citraconic anhydride, and one or more of these are used.

  The polyolefin resin may be a copolymer containing another monomer component having no reactivity. Examples of the other monomer components include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, methyl (meth) acrylate, butyl (meth) acrylate, styrene, butadiene, and the like. And monomers having no reactivity with an epoxy group, a carboxyl group or an acid anhydride group. The polyolefin resin may contain a homopolymer such as low density polyolefin, medium density polyolefin, high density polyolefin, and linear low density polyolefin.

  The amount of the functional group in the polyolefin resin is preferably 0.001 to 2 mmol / g. If the amount of the functional group in the polyolefin resin is within the above preferable range, the adhesion between the protective layer and the adhesive sealing layer can be further improved, and the water absorption of the adhesive sealing layer is more effective. Can be suppressed.

  The said adhesive sealing layer may contain conventionally well-known additives, such as a light stabilizer, a ultraviolet absorber, a heat stabilizer, a plasticizer, in the range which does not impair the physical property.

  The minimum with the preferable thickness of the said adhesive sealing layer is 80 micrometers, and a preferable upper limit is 700 micrometers. If the thickness of the adhesive sealing layer is less than 80 μm, the insulating property of the solar cell module may not be maintained. If the thickness exceeds 700 μm, the flame retardancy of the solar cell module may be adversely affected, or the weight of the solar cell module May become heavy. The minimum with more preferable thickness of the said adhesive sealing layer is 150 micrometers, and a more preferable upper limit is 500 micrometers.

  The method for producing the solar cell protective sheet of the present invention is not particularly limited. For example, the resin composition constituting the protective layer and the adhesive sealing layer is extruded from two extruders and laminated in a molten state. A co-extrusion method that extrudes into a sheet form from a mold on a stand, or a roll that laminates the protective layer and the adhesive sealing layer separately after each sheet is heated with a heating roll and then narrowed with a pair of nip rolls Examples thereof include a laminating method and a vacuum laminating method in which the protective layer and the adhesive sealing layer are separately formed into sheets and then heated while deaeration of the laminate of the protective layer and the adhesive sealing layer under reduced pressure. According to these methods, since the protective layer and the adhesive sealing layer are heated and melted, the reaction at the interface between the protective layer and the adhesive sealing layer is promoted. Among these, a co-extrusion method is suitable because a laminate can be produced in one process and the productivity and quality stability are excellent. In addition, when using a roll laminating method or a vacuum laminating method, you may laminate | stack with a solar cell element simultaneously, and may produce a solar cell module.

  The solar cell protective sheet of the present invention is used to seal a solar cell element and produce a solar cell module. The solar cell module in which the solar cell protective sheet of the present invention and the solar cell element in which the photoelectric conversion layer is disposed on the substrate are laminated and integrated are also one aspect of the present invention.

  The solar cell element is generally composed of a photoelectric conversion layer in which electrons are generated by receiving light, an electrode layer for taking out the generated electrons, and a base material. In FIG. 3, the longitudinal cross-sectional schematic diagram of an example of the solar cell element C by which the photoelectric converting layer 3 is arrange | positioned on the base material 4 is shown. Note that the electrode layer is omitted here because various arrangements are possible.

  Examples of the substrate include a flexible substrate made of a heat resistant resin such as polyimide, polyetheretherketone, polyethersulfone, and a rigid substrate made of glass.

Examples of the photoelectric conversion layer include crystal semiconductors such as single crystal silicon, single crystal germanium, polycrystalline silicon, and microcrystalline silicon, amorphous semiconductors such as amorphous silicon, GaAs, InP, AlGaAs, CdS, CdTe, and Cu _2. Examples thereof include compounds formed from compound semiconductors such as S, CuInSe ₂ and CuInS ₂ , and organic semiconductors such as phthalocyanine and polyacetylene. The photoelectric conversion layer may be a single layer or a multilayer.

  The electrode layer is a layer made of an electrode material. The said electrode layer may be on the said photoelectric converting layer as needed, and may be between the said photoelectric converting layer and a base material, and may be on the said base material surface. Further, the solar cell element may have a plurality of the electrode layers. Since the electrode layer on the light receiving surface side (surface) may block incident light, the electrode material is preferably a general transparent electrode material such as a metal oxide. Although it does not specifically limit as said transparent electrode material, ITO or ZnO etc. are used suitably. When the transparent electrode is not used, the bus electrode and the finger electrode attached thereto may be patterned with a metal such as silver. The electrode layer on the back side (back side) does not need to be transparent and may be made of a general electrode material, but silver is preferably used as the electrode material.

  It does not specifically limit as a method of manufacturing the said solar cell element, For example, it can manufacture by well-known methods, such as arrange | positioning the said photoelectric converting layer and an electrode layer on the said base material. The solar cell element may have a long shape wound in a roll shape or a rectangular sheet shape.

  As shown in FIG. 2, the solar cell module of the present invention has an adhesive sealing layer 2 and a protective layer 1 on the side of the photoelectric conversion layer 3 of the solar cell element C. Furthermore, the solar cell element C The adhesive sealing layer 2 and the protective layer 1 may also be provided on the side surface of the substrate 4. By having the adhesive sealing layer 2 and the protective layer 1 on the side surface of the substrate 4 of the solar cell element C, the solar cell element C can be sealed better and can stably generate power over a long period of time. It can be a battery module.

  The longitudinal cross-sectional schematic diagram of an example of the solar cell module F of this invention in the case of having the said adhesive sealing layer 2 and the said protective layer 1 in the photoelectric conversion layer 3 side surface and the base material 4 side surface of the said solar cell element C is a figure. 4 shows. FIG. 4 shows a schematic longitudinal sectional view of a solar cell module F of the present invention comprising a protective layer 1, an adhesive sealing layer 2, a photoelectric conversion layer 3, a base material 4, an adhesive sealing layer 2 and a protective layer 1 in order. .

  As a method for producing the solar cell module F of the present invention, the solar cell protective sheet B composed of the adhesive sealing layer 2 and the protective layer 1 is formed on at least the light receiving surface of the solar cell element C with a pair of heat. A method of constricting using a roll and thermocompression bonding can be mentioned. The light receiving surface of the solar cell element C is a surface that can receive light and is a surface on which the photoelectric conversion layer 3 of the solar cell element C is disposed. In the method for manufacturing the solar cell module F, the surface of the solar cell element C on which the photoelectric conversion layer 3 is disposed and the side of the adhesive sealing layer 2 of the solar cell protection sheet B face each other. A method of laminating the battery element C and the solar cell protective sheet B, constricting them using a pair of heat rolls, and thermocompression bonding is preferable.

  The preferable lower limit of the temperature of the heat roll when constricting using the pair of heat rolls is 70 ° C., and the preferable upper limit is 160 ° C. If the temperature of the heat roll is less than 70 ° C., adhesion failure may occur. If the temperature of the heat roll exceeds 160 ° C., wrinkles are likely to occur during thermocompression bonding. A more preferable lower limit of the temperature of the heat roll is 80 ° C., and a more preferable upper limit is 110 ° C.

  A preferable lower limit of the rotation speed of the heat roll is 0.1 m / min, and a preferable upper limit is 10 m / min. If the rotational speed of the heat roll is less than 0.1 m / min, wrinkles may easily occur after thermocompression bonding. When the rotation speed of the heat roll exceeds 10 m / min, there is a possibility that adhesion failure may occur. A more preferable lower limit of the rotation speed of the heat roll is 0.3 m / min, and a more preferable upper limit is 5 m / min.

  An example of the method for producing the solar cell module of the present invention will be specifically described with reference to FIG. As shown in FIG. 5, first, a long solar cell protective sheet B and a solar cell element C, which are composed of the protective layer and the adhesive sealing layer and are wound in a roll shape, are prepared. And the roll of the solar cell protection sheet B and the solar cell element C is unwound, and the light receiving surface of the photoelectric conversion layer of the solar cell element C and the adhesive sealing layer surface of the solar cell protection sheet B are arranged to face each other. Both are laminated to obtain a laminated sheet D. Next, the laminated sheet D is supplied between a pair of rolls E and E heated to a predetermined temperature, and the laminated sheet D is heated and thermocompression bonded while pressing in the thickness direction, so that the solar cell element C and the solar cell. The protective sheet B is bonded and integrated. Thereby, a photoelectric converting layer is sealed by the adhesive sealing layer, and the solar cell module A can be obtained.

  Moreover, as a method of sealing the base material side surface, for example, in the same manner as described above, the solar cell protective sheet of the present invention is placed on the base material side surface of the solar cell, and the adhesive sealing layer faces the base material. And a method of thermocompression bonding by constricting them using a pair of heat rolls. The step of thermocompression bonding the solar cell protection sheet to the side surface of the solar cell substrate may be performed before the step of thermocompression bonding the solar cell protection sheet on the light receiving surface of the solar cell element described above. May be done later or later.

  Using the solar cell protective sheet B of the present invention, for example, an example of a method for producing the solar cell module F of the present invention by simultaneously sealing the photoelectric conversion layer side surface and the substrate side surface of the solar cell element C. This will be described with reference to FIG. Specifically, while preparing a long solar cell element C wound in a roll shape, two long solar cell protection sheets B wound in a roll shape are prepared. And as shown in FIG. 6, while unwinding the elongate solar cell protection sheets B and B, respectively, unwind the elongate solar cell element C, and bond the two solar cell protection sheets B and B together. With the stop layers facing each other, the solar cell protective sheets B and B are overlapped with each other via the solar cell element C to obtain a laminated sheet D. And by supplying the laminated sheet D between a pair of rolls E, E heated to a predetermined temperature, and heating the laminated sheet D while pressing the laminated sheet D in the thickness direction, the solar cell protective sheets B, B are brought together. The solar cell module C is sealed by the solar cell protection sheets B and B, and the solar cell module F is continuously manufactured. In the production of the solar cell module F, the solar cell protective sheets B and B are overlapped with each other via the solar cell element C to form the laminated sheet D, and at the same time, the laminated sheet D is heated while pressing in the thickness direction. May be.

  Moreover, an example of the manufacturing method of the solar cell module of this invention at the time of using a rectangular sheet-like thing as the solar cell element C is shown in FIG. Specifically, instead of the long solar cell element C wound in a roll shape, a rectangular sheet-like solar cell element C having a predetermined size is prepared. And as shown in FIG. 7, the solar cell protection sheet which unwinded the elongate solar cell protection sheet B and B currently wound by roll shape, and made each adhesive sealing layer face each other. A solar cell element C is supplied between B and B at predetermined time intervals, and the solar cell protective sheets B and B are overlapped with each other via the solar cell element C to obtain a laminated sheet D. And by supplying the laminated sheet D between a pair of rolls E, E heated to a predetermined temperature, and heating the laminated sheet D while pressing the laminated sheet D in the thickness direction, the solar cell protective sheets B, B are brought together. The solar cell module C is sealed by the solar cell protection sheets B and B, and the solar cell module F is continuously manufactured. In the manufacture of the solar cell module, the laminated sheet D may be heated while being pressed in the thickness direction simultaneously with the formation of the laminated sheet D. The solar cell module F of the present invention can be suitably manufactured by applying such a roll-to-roll method.

  As a method for producing the solar cell module of the present invention, for example, the solar cell protective sheet and the solar cell element of the present invention cut into a desired shape are prepared, and the adhesive sealing layer of the solar cell protective sheet, In the state where the photoelectric conversion layer side surface of the solar cell element or both surfaces are opposed, the solar cell protection sheet and the solar cell element are laminated, and the obtained laminate is in a stationary state under reduced pressure. A method may be used in which the solar cell element is sealed with the solar cell protective sheet by heating while applying a pressing force in the thickness direction. The step of heating the laminate while applying a pressing force in the thickness direction under reduced pressure can be performed using a conventionally known apparatus such as a vacuum laminator.

  According to the present invention, it has a protective layer containing a fluororesin and a (meth) acrylic resin, and an adhesive sealing layer containing a polyolefin resin, and has an adhesive property between the protective layer and the adhesive sealing layer. A high-durability solar cell protective sheet and a solar cell module in which solar cell elements are protected by the solar cell protective sheet can be provided.

It is the longitudinal cross-sectional schematic diagram which showed an example of the solar cell protection sheet. It is the longitudinal cross-sectional schematic diagram which showed an example of the solar cell module of this invention. It is the longitudinal cross-sectional schematic diagram which showed an example of the solar cell element. It is the longitudinal cross-sectional schematic diagram which showed an example of the solar cell module of this invention. It is the schematic diagram which showed an example of the manufacturing point of the solar cell module of this invention. It is the schematic diagram which showed an example of the manufacturing point of the solar cell module of this invention. It is the schematic diagram which showed an example of the manufacturing point of the solar cell module of this invention.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
(1) Manufacture of solar cell protective sheet 70 parts by weight of polyvinylidene fluoride resin (trade name “KYNAR 740” manufactured by Arkema Co., Ltd.) as a fluorine resin, and a block copolymer of methyl methacrylate and butyl acrylate as a (meth) acrylic resin 30 parts by weight of a resin obtained by modifying the polymer with methacrylic acid (trade name “Nanostrength M75M” manufactured by Arkema Co., Ltd.) was supplied to the first extruder and melt-kneaded at 230 ° C. 100 parts by weight of a copolymer of ethylene and glycidyl methacrylate (trade name “LOTADER AX8840” manufactured by Arkema Co., Ltd.) as a polyolefin resin was supplied to the second extruder and melt-kneaded at 230 ° C. The molten resin constituting the protective layer and the adhesive sealing layer is supplied to the joining die that connects the first extruder and the second extruder together, and the sheet is formed from the T die that is connected to the joining die. To obtain a solar cell protective sheet having a long and constant width in which an adhesive protective layer having a thickness of 0.4 mm is laminated and integrated on one surface of a protective layer having a thickness of 0.04 mm. .

(2) Manufacture of solar cell module Using the obtained solar cell protective sheet, a solar cell module was prepared in the following manner. First, as shown in FIG. 3, a solar cell element C in which a thin film photoelectric conversion element 3 is formed on a base material 4 made of a flexible polyimide film and wound in a roll shape. On the other hand, two solar cell protective sheets B wound in a roll shape were prepared. Next, as shown in FIG. 6, the solar cell element C and the two solar cell protection sheets B and B are unwound, and the solar cell protection sheet B is overlapped via the solar cell element C to obtain a laminated sheet D. . In addition, the solar cell protection sheets B and B were overlapped so that the adhesive sealing layers faced each other. Thereafter, while supplying the laminated sheet D between a pair of rolls E, E heated to 140 ° C. and pressing the laminated sheet D in the thickness direction under an atmospheric pressure atmosphere where pressure and pressure are not applied. The solar cell protection sheets B and B are bonded and integrated by heating the laminated sheet D, whereby the solar cell element C is sealed with the solar cell protection sheets B and B, and the solar cell module F is continuously manufactured. And it wound up on the winding shaft which is not illustrated.

(Examples 2-6, Comparative Examples 1-2)
A solar cell protective sheet was produced in the same manner as in Example 1 except that the protective layer and the adhesive sealing layer were configured as shown in Table 1, and a solar cell module was produced using the solar cell protective sheet.

  Details of each of the other components shown in Table 1 are as follows.

((Meth) acrylic resin)
Copolymer of hydroxyl group-containing monomer (methacrylic acid-2-hydroxyethyl), methyl methacrylate and butyl acrylate (trade name “Nanostrength M55HM” manufactured by Arkema)
Copolymer of monomer having amide group (dimethylacrylamide), methyl methacrylate and butyl acrylate (manufactured by Arkema, trade name “Nanostrength M55N”)
Copolymer of epoxy group-containing monomer (glycidyl methacrylate), methyl acrylate, and ethylene (trade name “LOTADER AX8900” manufactured by Arkema)
Polymethylmethacrylate homopolymer (trade name “Altglas V044” manufactured by Arkema)

(Polyolefin resin)
Copolymer of monomer having an acid anhydride group (maleic anhydride), methyl acrylate and ethylene (trade name “LOTADER 4503” manufactured by Arkema)

(Evaluation)
The following evaluation was performed about the solar cell module obtained by the Example and the comparative example. The results are shown in Table 1.

(1) Peel strength between protective layer and adhesive sealing layer In the obtained solar cell module, the peel strength when the protective layer is peeled off from the adhesive sealing layer of the solar cell protective sheet laminated on the solar cell element is JIS K6854. Measured in conformity.

(2) High temperature and high humidity durability (adhesion)
In accordance with the procedure described in JIS C8990, the obtained solar cell module was left in an environment of 85 ° C. and a relative humidity of 85%. The time until the solar cell protective sheet laminated on the solar cell element side was peeled was observed every 500 hours, and the time when peeling was confirmed was measured. According to JIS C8990, which defines the authentication conditions for solar cell modules, durability of 1000 hours or more is required, and it can be determined that those that have been peeled off in 1000 hours are insufficient in adhesiveness.

(3) High temperature and high humidity durability (Pmax retention rate)
In accordance with the procedure described in JIS C8990, the obtained solar cell module is allowed to stand for 1000 hours in an environment of 85 ° C. and a relative humidity of 85%, and the maximum output Pmax after being left with respect to the maximum output Pmax0 before being left The retention rate (Pmax / Pmax 0 × 100 [%]) was calculated. In addition, Nissin Tor Co., Ltd. 1116N was used for the output measurement.

DESCRIPTION OF SYMBOLS 1 ... Protective layer 2 ... Adhesive sealing layer 3 ... Photoelectric conversion layer 4 ... Base material A, F ... Solar cell module B ... Solar cell protection sheet C ... Solar cell element D ... Laminated sheet E ... Roll

Claims (3)

  A solar cell protective sheet in which a protective layer containing a fluororesin and a (meth) acrylic resin and an adhesive sealing layer containing a polyolefin resin are laminated, wherein the (meth) acrylic resin is a carboxyl A solar cell protective sheet, which is a copolymer having a copolymer component having one type of functional group selected from a group, an acid anhydride group, a hydroxyl group, and an amide group, and wherein the polyolefin resin has an epoxy group.   A solar cell protective sheet in which a protective layer containing a fluororesin and a (meth) acrylic resin and an adhesive sealing layer containing a polyolefin resin are laminated, wherein the (meth) acrylic resin is an epoxy group A solar cell protective sheet, which is a copolymer having a copolymer component having one kind of functional group selected from amide groups and hydroxyl groups, and wherein the polyolefin resin has a carboxyl group or an acid anhydride group. A substrate;
A solar cell element having a photoelectric conversion layer disposed on the substrate;
A solar cell module which is laminated on the solar cell element and includes the solar cell protective sheet according to claim 1.

Images