JP2014187171A - Solar cell protective sheet and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell protective sheet, having high bonding properties between a protective layer and a bonding encapsulation layer and excellent durability, including a protective layer containing a (meta) acrylic resin and a bonding encapsulation layer containing a vinyl acetate base resin, and to provide a solar cell module whose solar cell element is protected by the same.SOLUTION: The solar cell protective sheet is formed by laminating a protective layer containing a (meta) acrylic resin and a bonding encapsulation layer containing a vinyl acetate base resin. At least one of the protective layer and the bonding encapsulation layer contains an esterification reaction catalyst.

Description

The present invention has a protective layer containing a (meth) acrylic resin and an adhesive sealing layer containing a vinyl acetate resin, and has high adhesion and excellent durability between the protective layer and the adhesive sealing layer. The present invention relates to a solar cell protective sheet and a solar cell module in which a solar cell element is protected by the solar cell protective 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.

As the adhesive sealing layer for sealing the solar cell element, it is a mainstream to use a vinyl acetate resin such as ethylene-vinyl acetate resin (for example, Patent Document 1). On the other hand, fluororesins such as poly (vinylidene fluoride) (PVDF) have been used for the protective layer because of its excellent weather resistance (for example, Patent Document 2).
On the other hand, for further widespread use of solar cells, use of an inexpensive (meth) acrylic resin as a protective layer in place of an expensive fluororesin has been studied. Since the (meth) acrylic resin is particularly excellent in weather resistance, it is considered that sufficient performance as a protective layer can be exhibited. For example, Patent Document 3 describes that (meth) acrylic resin may be used as a protective layer.

However, the adhesive sealing layer containing the vinyl acetate resin and the protective layer containing the (meth) acrylic resin have low adhesion, and the solar cell module sealed using this is left in the environment for a long time. Sometimes the protective layer peels off from the adhesive sealing layer, and the exposed surface of the adhesive sealing layer is whitened to reduce the amount of light received by the solar cell, or the solar cell element deteriorates due to damage to the adhesive sealing layer. As a result, there was a problem that the power generation efficiency was lowered.

JP 7-297439 A International Publication No. 2008/019229 Pamphlet JP-A-8-139347

The present invention has a protective layer containing a (meth) acrylic resin and an adhesive sealing layer containing a vinyl acetate resin, and has high adhesion and excellent durability between the protective layer and the adhesive sealing layer. Another object is to provide a solar cell protective sheet and a solar cell module in which a solar cell element is protected by the solar cell protective sheet.

The present invention is a solar cell protective sheet in which a protective layer containing a (meth) acrylic resin and an adhesive sealing layer containing a vinyl acetate resin are laminated, the protective layer and the adhesive sealing layer, A solar cell protective sheet containing an esterification reaction catalyst in at least one of the above.
The present invention is described in detail below.

As a result of intensive studies, the inventors of the present invention have developed a solar cell protective sheet in which a protective layer containing a (meth) acrylic resin and an adhesive sealing layer containing a vinyl acetate resin are laminated. By blending the esterification reaction catalyst with at least one of the sealing layer, the adhesiveness between the protective layer and the adhesive sealing layer is improved, and a solar cell protective sheet with excellent durability is obtained, The present invention has been completed.
This is thought to be because the esterification reaction catalyst causes a transesterification reaction at the interface between the protective layer and the adhesive sealing layer, which causes a strong bonding force between the protective layer and the adhesive sealing layer. . In addition, since the esterification reaction catalyst has a function of suppressing hydrolysis of (meth) acrylic resins and vinyl acetate resins, it prevents acid generation due to hydrolysis of these resins, and is Deterioration of the solar cell element can also be prevented.

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, the longitudinal cross-section schematic diagram of an example of the solar cell protection sheet B which consists of the protective layer 1 and the adhesion sealing layer 2 is shown.
When the solar cell element is protected using the solar cell protective sheet of the present invention, the protective layer is the outermost layer in the obtained solar cell module, and prevents external impact or corrosion of the solar cell element. Have a role to do.

The protective layer contains a (meth) acrylic resin.
In the present specification, (meth) acrylic resin means methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, and the like. It means a resin obtained by polymerizing a monomer containing at least one (meth) acrylic acid ester monomer.

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 components include 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. Is preferred. 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 protective layer may contain a resin other than the (meth) acrylic resin.
Examples of the resin other than the (meth) acrylic resin include resins excellent in compatibility with (meth) acrylic resins such as polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, and polystyrene.
When the protective layer contains a resin other than the (meth) acrylic resin, the content of the (meth) acrylic resin in the entire resin component is preferably 40% by weight or more. When the content of the (meth) acrylic resin is less than 40% by weight, the effect of improving the adhesiveness with the adhesive sealing layer may be insufficient.

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 protective layer may be subjected to corona discharge treatment on the surface in contact with the adhesive sealing layer. By performing the corona discharge treatment on the protective layer, the adhesion to the adhesive sealing layer can be further improved.
The corona discharge treatment to the protective layer can be performed by a conventionally known method. Specifically, for example, a commercially available corona discharge treatment device such as a high-frequency power supply device and a processing station manufactured by Kasuga Electric Co., Ltd. may be used to perform the treatment while feeding the protective layer to the corona discharge treatment stage.

The protective layer may have an embossed shape on a surface in contact with the adhesive sealing layer. When the protective layer has an embossed shape, adhesion to the adhesive sealing layer can be further improved. The emboss shape on the surface of the protective layer may be a regular uneven shape or a random uneven shape.

The protective layer may have an embossed shape on the surface opposite to the surface in contact with the adhesive sealing layer, that is, the surface that seals the solar cell element and becomes the outermost layer of the solar cell module. Good. When the outermost layer has an embossed shape, it is possible to reduce the reflection loss of sunlight, prevent glare, and improve the appearance.

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 vinyl acetate resin.
In this specification, the vinyl acetate resin means a vinyl acetate polymer or a derivative thereof. Specifically, a vinyl acetate polymer, a copolymer containing vinyl acetate, a saponified product thereof, the saponified product and an aldehyde. The addition reaction product (acetal) is included.
Examples of the vinyl acetate resin include ethylene-vinyl acetate resin (EVA), polyvinyl butyral resin (PVB), ethylene-vinyl alcohol resin (EVOH), and the like. These vinyl acetate resins may be used alone or in combination of two or more.

The adhesive sealing layer may contain a resin other than the vinyl acetate resin.
Examples of the resin other than the vinyl acetate resin include a polyolefin resin.
Examples of the polyolefin resin include, for example, polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, and ethylene-α-olefin copolymer containing more than 50% by weight of ethylene component. And polypropylene resins such as propylene-α-olefin copolymers containing more than 50% by weight of polypropylene resins, homopolypropylene, and propylene components.
Examples of the α-olefin copolymerized with ethylene include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and the like.
Examples of the α-olefin copolymerized with propylene include ethylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and the like.
Among these, the polyolefin-based resin is preferably a polyethylene-based resin, more preferably a low-density polyethylene, and even more preferably a linear low-density polyethylene.

When the adhesive sealing layer contains a resin other than the vinyl acetate resin, the content of the vinyl acetate resin in the entire resin component is preferably 40% by weight or more. If the content of the vinyl acetate resin is less than 40% by weight, the effect of improving the adhesion to the protective layer may be insufficient.

The adhesive sealing layer may contain an organic peroxide as a crosslinking agent. By blending the cross-linking agent, when the solar cell protective sheet is thermocompression bonded to the solar cell element and sealed, the adhesive sealing layer is cross-linked, and the heat resistance of the solar cell protective sheet is improved.
Examples of the organic peroxide include 2,5-dimethyl-2,5-di (t-butylperoxy) hexane.

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 400 micrometers.

At least one of the protective layer and the adhesive sealing layer contains an esterification reaction catalyst. The esterification reaction catalyst causes a transesterification reaction at the interface between the protective layer and the adhesive sealing layer, which causes a strong bonding force between the protective layer and the adhesive sealing layer. It is thought that the adhesion with the layer is improved.

Examples of the esterification reaction catalyst include organometallic compounds such as metal carboxylates, metal alkoxides, and metal glycol oxides. Specific examples include dibutyltin dilaurate, titanium tetra-i-propoxide, titanium tetra-n-butoxide, zirconium tetra-n-propoxide, and zirconium tetraacetylacetonate.

When the protective layer contains the esterification reaction catalyst, the preferred lower limit of the content of the esterification reaction catalyst is 0.01% by weight, the preferred upper limit is 3% by weight, and the more preferred lower limit is 0.05% by weight. A more preferred upper limit is 1% by weight.
When the said adhesive sealing layer contains the said esterification reaction catalyst, the minimum with preferable content of the said esterification reaction catalyst is 0.01 weight%, a preferable upper limit is 3 weight%, and a more preferable minimum is 0.05. The upper limit is 1% by weight.
When the esterification reaction catalyst is within this range, a particularly excellent effect of improving the adhesion between the protective layer and the adhesive sealing layer can be obtained.

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. Co-extrusion method to extrude into a sheet form from the mold of the stand, or extrusion laminating method in which the protective layer or adhesive sealing layer is formed into a sheet in advance and then another layer is extruded on the sheet and simultaneously laminated on a cooling roll Alternatively, after the protective layer and the adhesive sealing layer are separately formed into sheets, each is heated with a heating roll and then narrowed and laminated with a pair of nip rolls, or the protective layer and the adhesive sealing layer And then laminating the sheet separately, and then heating the laminated body of the protective layer and the adhesive sealing layer while degassing under reduced pressure. According to these methods, since the protective layer and the adhesive sealing layer are heated and melted, the transesterification 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 for manufacturing a solar cell module by sealing a solar cell element.
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 base material 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 the adhesive sealing layer 2 and the protective layer 1 on the side of the photoelectric conversion layer 3 of the solar cell element C. The adhesive sealing layer and the protective layer may also be provided on the side surface of the base material. By having the adhesive sealing layer and the protective layer on the substrate side surface of the solar cell element, the solar cell element is better sealed, and a solar cell module that can stably generate power over a long period of time is provided. Can do.

The longitudinal cross-sectional schematic diagram of an example of the solar cell module of this invention in the case of having the said adhesive sealing layer and the said protective layer in the photoelectric converting layer side surface and base-material side surface of the said solar cell element is shown in FIG.
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 of the present invention, the solar cell protective sheet composed of the adhesive sealing layer and the protective layer is constricted on at least the light receiving surface of the solar cell element by using a pair of heat rolls. And a method of thermocompression bonding.
The light receiving surface of the solar cell element is a surface that can receive light and is a surface on which the photoelectric conversion layer of the solar cell element is disposed.
In the method for manufacturing the solar cell module, the solar cell element and the solar cell in a state where the surface on which the photoelectric conversion layer of the solar cell element is disposed and the adhesive sealing layer side surface of the solar cell protective sheet face each other. A method of laminating battery protection sheets, 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 composed of the protective layer and the adhesive sealing layer and wound in a roll shape, and a solar cell element C 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. It may be done later or later.

FIG. 6 shows an example of a method for producing the solar cell module of the present invention by using the solar cell protective sheet of the present invention, for example, simultaneously sealing the photoelectric conversion layer side surface and the substrate side surface of the solar cell element. Will be described.
Specifically, while preparing a long solar cell element C wound in a roll shape, two long solar cell protective sheets 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 the adhesive sealing layer of two solar cell protection sheets is In a state of facing each other, the solar cell protective sheets B and B are overlapped with each other through 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, the solar cell protective sheets B and B are overlapped with each other via the solar cell element C to form a laminated sheet D, and at the same time, the laminated sheet D is heated while pressing in the thickness direction. Also good.

Moreover, an example of the manufacturing point of the solar cell module of this invention at the time of using the 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 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 (meth) acrylic resin and an adhesive sealing layer containing a vinyl acetate resin, and has high adhesion and durability between the protective layer and the adhesive sealing layer. And a solar cell module in which a solar cell element is protected by the solar cell protective sheet.

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 100 parts by weight of polymethyl methacrylate resin (trade name “Delpet SR8350” manufactured by Asahi Kasei Chemicals Co., Ltd.) as a (meth) acrylic resin, and dibutyltin dilaurate (Daikyo) as an esterification reaction catalyst The chemical composition manufactured by Kasei Kogyo Co., Ltd. (trade name “SXL-1”) and 0.1 parts by weight are introduced into a mixer (trade name “Supermixer SMV-100” manufactured by Kawata Co., Ltd.) and mixed for 5 minutes. It supplied to the extruder and melt-kneaded at 230 degreeC.
100 parts by weight of ethylene-vinyl acetate copolymer (trade name “DQDJ-3269” manufactured by Nihon Unicar Co., Ltd.) as a vinyl acetate resin is charged into a mixer (trade name “Supermixer SMV-100” manufactured by Kawata). The composition mixed for 5 minutes 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 A solar cell module was manufactured in the following manner using the obtained solar cell protective sheet.
First, as shown in FIG. 3, a solar cell element C in which a thin film-like photoelectric conversion layer 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 2-11, Comparative Examples 1-4)
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 Tables 1 and 2, and a solar cell module was produced using the solar cell protective sheet. .

Details of the other components shown in Tables 1 and 2 are as follows.
(Resin excellent in compatibility with (meth) acrylic resin)
Polyvinylidene fluoride resin (trade name “Kyner 740” manufactured by Arkema)
(Vinyl acetate resin)
Polyvinyl butyral resin (Sekisui Chemical Co., Ltd., trade name "ESREC BL")
(Polyolefin resin)
Ethylene-methyl acrylate copolymer (trade name “Rotoryl 20MA08” manufactured by Arkema)
Acid-modified ethylene-α olefin copolymer (Mitsui Chemicals, trade name “Admer XE070”)
(Plasticizer)
Dioctyl phthalate (product name "DOP", manufactured by GE Esther)

(Esterification reaction catalyst)
Titanium tetra-i-propoxide (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name “Orga Tix TA-10”)
Titanium tetra-n-butoxide (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name “Orga Tix TA-25”)
Zirconium tetraacetylacetonate (Matsumoto Fine Chemical Co., Ltd., trade name "Orgachix ZC-150")

(Evaluation)
The following evaluation was performed about the solar cell module obtained by the Example and the comparative example.
The results are shown in Tables 1 and 2.

(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 defined in 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.

According to the present invention, it has a protective layer containing a (meth) acrylic resin and an adhesive sealing layer containing a vinyl acetate resin, and has high adhesion and durability between the protective layer and the adhesive sealing layer. And a solar cell module in which a solar cell element is protected by the solar cell protective sheet.

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

Claims (2)

A solar cell protective sheet in which a protective layer containing a (meth) acrylic resin and an adhesive sealing layer containing a vinyl acetate resin are laminated, on at least one of the protective layer and the adhesive sealing layer A solar cell protective sheet comprising an esterification catalyst. A solar cell module, wherein the solar cell protective sheet according to claim 1 and a solar cell element in which a photoelectric conversion layer is disposed on a substrate are laminated and integrated.

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