JP2016006814A - Solar cell sealing tape and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell sealing tape having high transparency and excellent barrier durability.SOLUTION: The solar cell sealing tape includes a barrier sheet fulfilling a gas barrier function, and an adhesive layer laminated on the barrier sheet and containing an acrylic adhesive. The thickness of the barrier sheet is 5-500 μm, the acrylic adhesive contains a curing agent, the glass transition temperature of the acrylic adhesive is 0-30°C, and the gel fraction of the acrylic adhesive is 60-99.5 wt.%.

Description

  The present invention relates to a solar cell sealing tape, and in particular, a solar cell sealing tape comprising a barrier sheet that performs a gas barrier function and a pressure-sensitive adhesive layer laminated on the barrier sheet, and the solar cell sealing tape. It is related with a solar cell module provided with a stop tape.

  In recent years, application of solar cell modules to a wider range of fields has been studied. In particular, in the mobile field and the like, since light weight and flexibility that can be bent freely are required, studies have been made to manufacture a solar cell module using a flexible material.

  For example, Patent Document 1 below discloses a solar cell module in which a surface protective material, a barrier sheet, and a sealing material are formed of a flexible material. In Patent Document 1, a thermoplastic elastomer (TPU) or EVA as a sealing material is sandwiched between a barrier sheet and a solar cell. Next, the solar cell module is manufactured by pressure bonding at a temperature of 120 to 160 ° C. for 10 to 20 minutes.

WO2010 / 019496

  However, as in Patent Document 1, in the method of thermocompression bonding at a high temperature for a long time using a sealing material such as thermoplastic elastomer (TPU) or EVA, the barrier sheet deteriorates and the barrier performance decreases with time. There was something to do. That is, the power generation efficiency of the solar cell module may decrease due to long-term use.

  Moreover, in the method of thermocompression bonding, bubbles are likely to be generated, and transparency may be lowered. Furthermore, the generated bubbles are likely to enter the interface between the barrier sheet and the sealing material. Therefore, also from this point, the barrier sheet deteriorates due to long-term use, and the power generation efficiency of the solar cell module may decrease.

  An object of the present invention is to provide a solar cell sealing tape having high transparency and excellent barrier durability and a solar cell module including the solar cell sealing tape.

  As a result of intensive studies, the inventor of the present application has a barrier sheet that performs a gas barrier function, and a sealing tape for a solar cell that includes a pressure-sensitive adhesive layer that is laminated on the barrier sheet and contains an acrylic pressure-sensitive adhesive. It was found that the above-mentioned problems can be achieved by limiting the glass transition temperature and gel fraction of the acrylic pressure-sensitive adhesive to a specific range.

  That is, the solar cell sealing tape according to the present invention includes a barrier sheet that performs a gas barrier function, and a pressure-sensitive adhesive layer that is laminated on the barrier sheet and contains an acrylic pressure-sensitive adhesive. The thickness of the barrier sheet is 5 to 500 μm, the acrylic pressure-sensitive adhesive contains a curing agent, the glass transition temperature of the acrylic pressure-sensitive adhesive is 0 ° C. to 30 ° C., and the acrylic pressure-sensitive adhesive The gel fraction is 60% to 99.5% by weight.

  In the solar cell sealing tape according to the present invention, preferably, the barrier sheet is flexible glass.

  In the solar cell sealing tape according to the present invention, preferably, the flexible glass is glass produced by an overflow down draw method.

  A solar cell module according to the present invention includes a solar cell power generation layer and a solar cell sealing tape according to the present invention, which is laminated on one surface of the solar cell power generation layer.

  According to the present invention, it is possible to provide a solar cell sealing tape having high transparency and excellent barrier durability. Moreover, since the solar cell module which concerns on this invention is equipped with the said sealing tape for solar cells, even if it uses for a long period of time, it is hard to reduce electric power generation efficiency.

  Details of the present invention will be described below.

[Seal tape for solar cells]
The sealing tape for solar cells according to the present invention includes a barrier sheet that performs a gas barrier function and an adhesive layer. An adhesive layer is formed on the barrier sheet. The barrier sheet has a thickness of 5 to 500 μm. The pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive.

  Thus, in the present invention, since the pressure-sensitive adhesive layer containing the acrylic pressure-sensitive adhesive is formed on the barrier sheet, the solar cell can be sealed at room temperature, and the barrier sheet hardly deteriorates. . That is, the solar cell sealing tape according to the present invention is excellent in barrier durability.

  Moreover, in this invention, the glass transition temperature of the said acrylic adhesive is 0 degreeC-30 degreeC, and the gel fraction of the said acrylic adhesive is 60 weight%-99.5 weight%. Therefore, in the sealing tape for solar cells according to the present invention, bubbles are hardly generated. Therefore, the solar cell sealing tape according to the present invention is excellent in transparency.

  Moreover, in the solar cell sealing tape according to the present invention, since the bubbles are unlikely to enter the interface between the sealing material, which is an adhesive layer, and the barrier sheet, the barrier sheet is unlikely to deteriorate. That is, the solar cell sealing tape according to the present invention is excellent in durability barrier properties. Therefore, when the solar cell sealing tape according to the present invention is used as a surface protective layer and a sealing material-integrated protective sheet of a solar cell module, the power generation efficiency of the solar cell module is unlikely to decrease due to long-term use. That is, the lifetime of the solar cell module can be extended.

  Moreover, the sealing tape for solar cells which concerns on this invention can be comprised by the barrier sheet and adhesive layer with thin thickness and high flexibility. Therefore, it can be suitably used as a surface protective layer and a sealing layer integrated protective sheet of a solar cell module for the mobile field.

  Hereinafter, each constituent member of the solar cell sealing tape according to the present invention will be described in more detail.

(Barrier sheet)
The barrier sheet according to the present invention is preferably a lightweight sheet that can be bent freely, that is, a sheet having flexibility and a gas barrier function. More preferably, it is desirable to use flexible glass or a laminated barrier film described later as the barrier sheet.

Flexible glass;
The flexible glass is light and can be bent freely. The flexible glass has a gas barrier function that prevents permeation of gases such as water vapor and oxygen.

  Although the thickness of the said flexible glass is not specifically limited, It is preferable that they are 10 micrometers-200 micrometers. If the flexible glass is too thin, sufficient gas barrier performance may not be obtained. If the flexible glass is too thick, the flexible glass may break during pressure bonding. Therefore, the thickness of the flexible glass is more preferably in the range of 5 μm to 300 μm, and still more preferably in the range of 10 μm to 150 μm.

The material constituting the flexible glass, _but are not limited _{to, SiO 2, Al 2 O 3} , B 2 O 3, MgO, CaO, SrO, BaO, Na 2 O, etc. Li ₂ O and the like. These may be used alone or in combination of two or more.

As a material constituting the flexible glass, it is preferable to use a combination of SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ or the like as a network former. It is preferable to add MgO, CaO, SrO, BaO, Na ₂ O, Li ₂ O or the like as the third component. More preferably, by mass percentage, a SiO ₂ 50-70% of _{Al 2 O 3 10~25%, B} 2 O 3 1 to 15% of MgO 0% 0 to 15% of CaO, SrO 0 to 15% 0 to 15% of BaO, it is preferable to use Na ₂ O 0 to 5% and Li ₂ O in combination in a proportion of 0-3%.

  Examples of the method for producing the flexible glass include an overflow down draw method and a float method. Preferably, it is desirable to produce by the overflow down draw method, but it may be produced by the float method.

Laminated barrier film;
The laminated barrier film includes a resin film and an inorganic film. An inorganic film is laminated on the resin film. But as long as the effect of this invention is not inhibited, the other film may be laminated | stacked.

  The material constituting the resin film is not particularly limited, but is a homopolymer such as ethylene, propylene, or butene; a copolymer containing ethylene, propylene, or butene; an amorphous polyolefin such as a cyclic polyolefin; or an olefin copolymer. Polymer: Polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); Polyamide such as nylon 6, nylon 66, nylon 12, copolymer nylon; ethylene-vinyl acetate copolymer partial hydrolyzate (EVOH), Examples include polyimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone, polycarbonate, polyvinyl butyral, polyarylate, fluororesin, acrylic resin, and biodegradable resin.

  Especially, as a material which comprises a resin film, a thermoplastic resin is preferable. Moreover, since the mechanical physical property of a resin film can be improved and cost can be reduced, polyester, polyamide, or polyolefin is more preferable. Polyesters such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) that can further enhance the mechanical properties of the film are particularly preferred.

  The resin film is preferably coated with an anchor coating agent in order to improve adhesion with the inorganic film and to smooth the resin film surface. Examples of anchor coating agents include solvent-based or aqueous polyester resins, isocyanate resins, urethane resins, acrylic resins, modified vinyl resins, vinyl alcohol resins, and other alcoholic hydroxyl group-containing resins, vinyl butyral resins, nitrocellulose resins, and oxazoline group-containing resins. , Carbodiimide group-containing resins, methylene group-containing resins, epoxy group-containing resins, modified styrene resins, modified silicone resins, and the like. These may be used alone or in combination of two or more.

  In the laminated barrier film, an inorganic film as a layer exhibiting a gas barrier function is laminated on the resin film. The inorganic film may be provided only on one side of the resin film, or may be provided on both sides of the resin film. A plurality of inorganic films having different compositions may be stacked.

  The inorganic film is not particularly limited as long as it is a thin film made of an inorganic substance capable of suppressing the permeation of gas containing water vapor. Examples of such an inorganic substance include silicon, aluminum, magnesium, zinc, tin, nickel, titanium, hydrocarbon, and the like, or oxides, carbides, nitrides, or mixtures thereof. Preferably, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide and the like are used, and the gas barrier property can be further enhanced. Silicon oxide and aluminum oxide are particularly preferable in terms of stably expressing high gas barrier properties. Although the said inorganic substance may be used independently, it may be used in combination of 2 or more type. A combination of zinc, tin and silicon is preferable in terms of flexibility.

  The thickness of the laminated barrier film is not particularly limited as long as it is in the range of 5 μm to 500 μm. If the thickness of the laminated barrier film is too thin, sufficient gas barrier performance may not be obtained, and if the laminated barrier film is too thick, the laminated barrier film may be damaged during pressure bonding. Therefore, the thickness of the laminated barrier film is more preferably in the range of 10 μm to 200 μm.

(Adhesive layer)
The said adhesive layer is used as a sealing material layer of a solar cell module. The pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive. The glass transition temperature of the acrylic pressure-sensitive adhesive is 0 ° C to 30 ° C.

  When the glass transition temperature is lower than the lower limit, bubbles are likely to be generated after the solar cell is sealed. In this case, it is not only unfavorable in appearance, but may cause deterioration of the solar cell. Moreover, when a glass transition temperature is higher than the said upper limit, since an adhesive becomes too hard, it may become difficult to follow the unevenness | corrugation of the cell surface for solar cells. Therefore, the glass transition temperature of the acrylic pressure-sensitive adhesive is more preferably in the range of 0 ° C. to 20 ° C., and further preferably in the range of 0 ° C. to 10 ° C.

  The gel fraction of the acrylic pressure-sensitive adhesive is 60% by weight to 99.5% by weight. When the gel fraction is lower than the lower limit, bubbles are likely to be generated after the solar cell is sealed. In this case, it is not only unfavorable in appearance, but may cause deterioration of the solar cell. In addition, when the gel fraction is higher than the above upper limit value, the pressure-sensitive adhesive becomes too hard, and it may be difficult to follow the unevenness on the surface of the solar cell. Therefore, the gel fraction of the acrylic pressure-sensitive adhesive is more preferably in the range of 60% by weight to 98% by weight, and still more preferably in the range of 60% by weight to 95% by weight. In addition, about the measuring method of the said gel fraction, it shall explain in detail in the Example mentioned later.

  Examples of the main monomer component of the acrylic pressure-sensitive adhesive include alkyl acrylates such as ethyl acrylate, butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, and benzyl acrylate, And alkyl methacrylates such as butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate or benzyl methacrylate. These may be used alone or in combination of two or more.

  The acrylic pressure-sensitive adhesive may contain a comonomer component. Examples of the comonomer component include methyl acrylate, methyl methacrylate, ethyl methacrylate, vinyl acetate, styrene, and acrylonitrile. These may be used alone or in combination of two or more.

  Examples of the initiator used for the polymerization of the monomer component include azobisisobutylnitrile, benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, and the like.

  The acrylic pressure-sensitive adhesive contains a curing agent. Examples of the curing agent include an isocyanate curing agent, an aziridine curing agent, an epoxy curing agent, and a metal chelate curing agent. Of these, isocyanate-based curing agents are preferable because performances such as heat resistance and durability are easily exhibited.

  Moreover, when the acrylic polymer used as the main component of the said acrylic adhesive is a copolymer, any of a random, block, and graft copolymer may be sufficient.

  The acrylic pressure-sensitive adhesive in the present invention preferably contains an ultraviolet absorber. Examples of ultraviolet absorbers that can be used include benzophenone, benzotriazole, triazine, and salicylic acid ester.

  Examples of the benzophenone-based UV absorber include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-n. -Dodecyloxybenzophenone, 2-hydroxy-4-n-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2 , 4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, etc. It is possible.

  The acrylic pressure-sensitive adhesive may further contain other components as long as the effects of the present invention are not impaired. Examples of such components include fine particles such as olefin elastomers, styrene elastomers, tackifiers, and silica.

  The pressure-sensitive adhesive layer may be formed by directly applying an acrylic pressure-sensitive adhesive on the barrier sheet, or the pressure-sensitive adhesive is applied to the release-treated surface of the release-treated release sheet and transferred to the barrier sheet. You may form by doing.

  Coating of the acrylic pressure-sensitive adhesive is conventionally known, for example, a bar coating method, a roll coating method, a knife coating method, a roll knife coating method, a die coating method, a gravure coating method, an air doctor coating method or a doctor blade coating method. It can be performed by a coating method.

  The thickness of the pressure-sensitive adhesive layer is preferably 15 μm or more, more preferably 20 μm or more, and further preferably 25 μm or more. The thickness of the pressure-sensitive adhesive layer is preferably 500 μm or less, and more preferably 400 μm or less. If the thickness of the pressure-sensitive adhesive layer is too thin, sufficient adhesive strength may not be obtained. On the other hand, if the thickness of the pressure-sensitive adhesive layer is too thick, coatability may be deteriorated.

  Moreover, when the said barrier sheet is the laminated barrier film mentioned above, it is preferable that the inorganic film surface is contacting the adhesive layer. In this case, since the durability barrier property of the barrier sheet can be further enhanced, the lifetime of the solar cell module can be further prolonged.

[Solar cell module]
The solar cell module according to the present invention includes a solar cell power generation layer and the solar cell sealing tape configured according to the present invention, which is laminated on one surface of the solar cell power generation layer.

  But the solar cell module which concerns on this invention may be provided with the back surface protective layer laminated | stacked on the surface on the opposite side to the surface where the said solar cell sealing tape of the said solar cell power generation layer is laminated | stacked. Good.

  The said back surface protective layer fulfill | performs the function which protects the electric power generation layer for solar cells from water, an ultraviolet-ray, oxygen, etc. in a back surface side. The said back surface protective layer may be comprised with the appropriate material which expresses the above desired functions. When configuring a flexible solar cell module, a flexible back surface protective layer is preferably used.

  As such a back surface protective layer having flexibility, a laminate in which a metal layer such as steel or aluminum and a polyvinyl fluoride layer are laminated, polyethylene terephthalate, polyethylene naphthalate, PVF / PET / PVF laminate Or a film made of PVDF or the like is preferably used. In addition, the said film may be used independently and multiple layers may be laminated | stacked and used.

  When the flexible back surface protective layer is used as described above, a flexible solar cell module can be easily provided. In this case, it is desirable that the surface-side solar cell sealing tape also has flexibility.

  The solar cell power generation layer includes a photoelectric conversion portion constituted by a known solar cell and an electrode for extracting generated electricity. The specific structure of the solar cell is not particularly limited.

  When the flexible solar cell module is configured, the back surface protective layer may be lined with a flexible base material. That is, when the front side sealing sheet-integrated solar cell protective sheet, the solar cell power generation layer, and the back surface protective layer are very thin, they may be backed by a flexible substrate. Such a flexible substrate is not particularly limited, and can be formed using an appropriate resin having excellent heat resistance such as polyimide, polyetheretherketone, polyethersulfone.

The material constituting the solar cell is not particularly limited, and any appropriate material that can convert sunlight into current can be used. For example, crystalline 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, Cu ₂ S, CuInSe ₂ , CuInS ₂ And compound semiconductors such as those formed from organic semiconductors such as phthalocyanine and polyacetylene.

  The solar battery cell in the solar battery power generation layer may be a single layer or multiple layers. The thickness of the solar cell is not particularly limited, but is preferably about 0.5 to 10 μm.

  The method for manufacturing the solar cell module is not particularly limited. For example, when manufacturing a flexible solar cell module, each layer may be appropriately laminated on the flexible substrate. Moreover, in the case of a flexible solar cell module, it may be wound in a roll shape. Further, the solar cell module may be formed into a sheet shape having an appropriate planar shape such as a rectangular shape.

  As described above, the solar cell module according to the present invention includes the solar cell sealing tape configured according to the present invention. Therefore, in the method for manufacturing a solar cell module according to the present invention, the solar cell sealing tape can be formed on the solar cell power generation layer by being crimped at room temperature without being crimped at a high temperature. Thus, a solar cell module can be obtained.

  Therefore, in the manufacturing method of the solar cell module according to the present invention, the generation of bubbles can be suppressed. Therefore, a highly transparent solar cell module can be obtained.

  Moreover, since it can crimp at room temperature, it is hard to produce the damage of the barrier sheet which comprises the sealing tape for solar cells. That is, since the solar cell sealing tape constituting the solar cell module according to the present invention is excellent in barrier durability, it is possible to provide a solar cell module that can generate power stably over a long period of time.

  As described above, even when the solar cell module according to the present invention is made of a flexible material, the solar cell module has high transparency and can stably generate power over a long period of time. Therefore, the solar cell module according to the present invention can be suitably used in the mobile field and the like.

[Examples and Comparative Examples]
Next, the present invention will be further clarified by giving examples and comparative examples of the present invention. In addition, this invention is not limited to a following example.

(Example 1)
Preparation of the barrier sheet;
As the barrier sheet, flexible glass (manufactured by Nippon Electric Glass Co., Ltd., trade name “0A-10G”, thickness 50 μm) was prepared.

Preparation of acrylic adhesive A;
28 parts by weight of an acrylic adhesive (manufactured by Soken Chemical Co., Ltd., trade name “1838”) and 0.025 part by weight of an isocyanate-based crosslinking agent (trade name Coronate L-55, produced by Nippon Polyurethane Co., Ltd.) as a curing agent Acrylic pressure-sensitive adhesive A was prepared by mixing at 60 ° C. for 60 minutes. The resulting acrylic pressure-sensitive adhesive A had a glass transition temperature (Tg) of 4 ° C. and a gel fraction of 87% by weight.

  In this example and comparative example, the Tg of the pressure-sensitive adhesive was increased to a test temperature of −80 ° C. to 150 ° C. using a dynamic viscoelasticity measuring device (trade name “DVA-200” manufactured by IT Measurement Control Co., Ltd.). Measurement was performed under conditions of a temperature condition of 5 ° C./minute, a deformation method of shearing, and a frequency of 10 Hz.

  Moreover, about the gel fraction of an adhesive, it measured in the following procedures.

  First, a predetermined amount Xg of adhesive and a sealed container charged with a predetermined excess of ethyl acetate were prepared. Next, the pressure-sensitive adhesive was put into ethyl acetate, and stirred with vibration at room temperature for 24 hours. Thereafter, the residue that did not dissolve in ethyl acetate was collected, dried at 110 ° C. for 1 hour, and then the residual weight Yg was measured. Said Y / X (x100) was computed and it was set as the gel fraction (weight%).

Production of sealing tape for solar cells;
Next, the sealing tape for solar cells of the structure where the said acrylic adhesive A was laminated | stacked on the said barrier sheet wound by roll shape was produced. Specifically, the sealing tape for solar cells was produced by applying, drying and laminating acrylic pressure-sensitive adhesive A with a comma coater. In addition, the thickness of the sealing material layer which is an adhesive layer was 100 micrometers.

Production of solar cell modules;
A solar cell element was prepared in which a photoelectric conversion layer made of a thin film-like amorphous silicon was formed on a flexible substrate made of a flexible polyimide film and wound in a roll shape.

Next, the solar cell module was fabricated by laminating the prepared sealing tape for solar cell and the solar cell element by pressing with ^two rolls at room temperature at a pressure of 0.5 kg / cm ² .

  In addition, as a method of pressure-bonding and laminating with the two rolls, for example, the solar cell sealing tape of the present invention is placed on the upper surface of the flexible substrate made of the polyimide film, and the adhesive layer faces the flexible substrate. Thus, thermocompression bonding can be performed by narrowing using a pair of heat rolls.

  The step of thermocompression bonding the solar cell sealing tape to the upper surface of the flexible substrate is performed by heating the surface opposite to the light receiving surface after the step of thermocompression bonding the solar cell sealing tape on the light receiving surface of the solar cell. A step of crimping may be performed, these may be performed simultaneously, or may be performed later.

(Example 2)
A solar cell sealing tape and a solar cell module were produced in the same manner as in Example 1 except that flexible glass (manufactured by Corning, trade name “Willow Glass”, thickness 100 μm) was used as the barrier sheet.

(Example 3)
Instead of the acrylic adhesive A, an acrylic adhesive B (Tg 23 ° C., gel fraction 89% by weight) was used in the same manner as in Example 2 except that a 150 μm thick sealing material layer was formed. A solar cell sealing tape and a solar cell module were produced.

  The acrylic pressure-sensitive adhesive B is 100 parts by weight of an acrylic pressure-sensitive adhesive (manufactured by Soken Chemical Co., Ltd., trade name “2990”) and an isocyanate cross-linking agent (manufactured by Nippon Polyurethane Co., Ltd., trade name “Coronate L-55”). ) 0.1 part by weight was mixed and prepared at 28 ° C. for 60 minutes.

Example 4
Instead of the acrylic adhesive A, an acrylic adhesive C (Tg 0 ° C., gel fraction 67% by weight) was used in the same manner as in Example 2 except that a 150 μm thick sealing material layer was formed. A solar cell sealing tape and a solar cell module were produced.

  The acrylic pressure-sensitive adhesive C is an acrylic pressure-sensitive adhesive (manufactured by Sekisui Chemical Co., Ltd., trade name “5400S”) and an isocyanate-based cross-linking agent (manufactured by Nippon Polyurethane Co., Ltd., trade name “Coronate L-55”. ]) 0.025 weight part was mix | blended and it mixed by mixing for 60 minutes at 28 degreeC.

(Example 5)
A solar cell sealing tape and a solar cell module were used in the same manner as in Example 1 except that a laminated barrier film (manufactured by Sekisui Chemical Co., Ltd., trade name “S-1”, thickness 100 μm) was used as the barrier sheet. Was made.

(Comparative Example 1)
As a barrier sheet, a thin glass (manufactured by Corning, trade name “Gorilla Glass”, thickness 550 μm) was used and cut into A4 size. Separately, an acrylic pressure-sensitive adhesive A used in Example 1 of A4 size was prepared. Thereafter, a thin glass plate was attached to one surface of the prepared acrylic pressure-sensitive adhesive A at room temperature to produce a solar cell sealing tape. Next, the solar cell element was sealed to produce a solar cell module by bonding and integrating the solar cell element used in Example 1 to the other surface of the acrylic adhesive A of the solar cell sealing tape. .

(Comparative Example 2)
In the same manner as in Example 1, except that an acrylic adhesive D (Tg 0 ° C., gel fraction 58 wt%) was used instead of the acrylic adhesive A and a 150 μm-thick sealing material layer was formed, A battery sealing tape and a solar cell module were produced.

  The acrylic pressure-sensitive adhesive D includes 100 parts by weight of an acrylic pressure-sensitive adhesive (manufactured by Soken Chemical Co., Ltd., trade name “1298”) and an isocyanate cross-linking agent (manufactured by Nippon Polyurethane Co., Ltd., trade name “Coronate L-55”). ) 0.025 part by weight was mixed and prepared by mixing at 28 ° C. for 60 minutes.

(Comparative Example 3)
Instead of acrylic adhesive A, acrylic adhesive E (Tg-5 ° C., gel fraction 48% by weight) was used, and the same procedure as in Example 1 was performed except that a 150 μm thick sealing material layer was formed. A solar cell sealing tape and a solar cell module were produced.

  The acrylic pressure-sensitive adhesive E is 100 parts by weight of an acrylic pressure-sensitive adhesive (manufactured by Soken Chemical Co., Ltd., trade name “0822”), and an isocyanate cross-linking agent (trade name Coronate L-55, made by Nippon Polyurethane Co., Ltd.) as a curing agent. 0.025 part by weight was blended and mixed at 28 ° C. for 60 minutes to prepare.

(Comparative Example 4)
A solar cell module was manufactured by forming an encapsulant layer having a thickness of 150 μm using EVA (manufactured by Sekisui Film Co., Ltd., trade name “SP Sealant”) instead of the acrylic adhesive A. Specifically, the flexible glass used in Example 1, the above-mentioned sealing material layer, the solar cell element used in Example 1, the above-mentioned sealing material layer, and a polyvinyl fluoride system having a thickness of 38 μm as the back surface protective sheet. A laminated sheet composed of a resin sheet (PVF), an aluminum foil having a thickness of 30 μm, and a polyvinyl fluoride resin sheet (PVF) having a thickness of 38 μm is laminated in this order, with the solar cell element surface facing upward, and a solar cell module The solar cell module was manufactured by pressure-bonding at 150 ° C. for 15 minutes using a vacuum laminator for manufacturing the above.

(Comparative Example 5)
A solar cell module was manufactured by forming a 150 μm-thick sealing material layer using polyolefin (manufactured by Dai Nippon Printing Co., Ltd., trade name “Z68”) instead of the acrylic pressure-sensitive adhesive A. Specifically, the flexible glass used in Example 1, the above-mentioned sealing material layer, the solar cell element used in Example 1, the above-mentioned sealing material layer, and a polyvinyl fluoride system having a thickness of 38 μm as the back surface protective sheet. A laminated sheet composed of a resin sheet (PVF), an aluminum foil having a thickness of 30 μm, and a polyvinyl fluoride resin sheet (PVF) having a thickness of 38 μm is laminated in this order, with the solar cell element surface facing upward, and a solar cell module The solar cell module was manufactured by pressure-bonding at 150 ° C. for 15 minutes using a vacuum laminator for manufacturing the above.

(Evaluation)
About the solar cell module obtained in Examples 1-5 and Comparative Examples 1-5, evaluation was implemented about the following evaluation items.

(1) Module crack The presence or absence of the crack of the barrier sheet by the crimping | compression-bonding at the time of solar cell module preparation was confirmed visually, and the following evaluation criteria evaluated.

○ ・ ・ ・ No occurrence of cracks or cracks × ・ ・ ・ There is occurrence of cracks or cracks

(2) Number of bubbles 10 solar cell modules obtained were cut into a size of 100 cm ² , the number of bubbles that could be visually confirmed was counted, and the result for 10 samples was taken as 100 times the average number. .

(3) Adhesive strength The barrier sheet and the sealing material layer of the obtained solar cell module were peeled into a T-shape using Tensilon (manufactured by Toyo Seiki Seisakusho) in accordance with JIS K6854, and the adhesive strength was measured. did.

(4) Transparency Regarding the transparency of the obtained solar cell module, the total light transmittance of the solar cell module was determined in accordance with JIS K7361 using a haze meter (trade name “Haze Guard 2” manufactured by Toyo Seiki Seisakusho Co., Ltd.). It was evaluated by measuring.

(5) Endurance deterioration The endurance deterioration of the obtained solar cell module is to determine the rate of decrease in power generation efficiency after 1000 hours in an environment of 85% humidity and 85% RH with respect to the initial power generation efficiency of the solar cell module. Based on the following evaluation criteria.

○ ・ ・ ・ Durability degradation of power generation efficiency is within 10% △ ・ ・ ・ Durability degradation of power generation efficiency is more than 10% and less than 25% × ・ ・ ・ Durability degradation of power generation efficiency is 25% or more

  Details and results of Examples 1 to 5 and Comparative Examples 1 to 5 are shown in Table 1 below.

Claims (4)

A barrier sheet that performs a gas barrier function;
An adhesive layer that is laminated on the barrier sheet and contains an acrylic adhesive, and
The barrier sheet has a thickness of 5 to 500 μm,
The acrylic pressure-sensitive adhesive contains a curing agent,
The glass transition temperature of the acrylic pressure-sensitive adhesive is 0 ° C. to 30 ° C.,
The sealing tape for solar cells whose gel fraction of the said acrylic adhesive is 60 weight%-99.5 weight%.   The solar cell sealing tape according to claim 1, wherein the barrier sheet is flexible glass.   The sealing tape for solar cells of Claim 2 whose said flexible glass is the glass manufactured by the overflow downdraw method.   A solar cell module comprising: a solar cell power generation layer; and the solar cell sealing tape according to any one of claims 1 to 3, which is laminated on one surface of the solar cell power generation layer.