JP2010267853A - Package for storing or transporting solar cell-sealing film, and method for storing or transporting solar cell-sealing film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a defect in outward appearance and a decrease in power generation efficiency of a solar cell module by suppressing sticking of a sulfur component, contained in a package member, on the solar cell-sealing film while suppressing volatilization and deterioration of a crosslinking agent etc., contained in the solar cell-sealing film during storage and transportation. <P>SOLUTION: The package for storing or transporting the solar cell-sealing film includes the solar cell-sealing film and a package sheet for packaging the solar cell-sealing film, wherein the content of a sulfur element per unit volume of the package sheet is equal to or less than 1.1×10<SP>-3</SP>μg/mm<SP>3</SP>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a package for storing or transporting a solar cell sealing film, and a method for storing or transporting a solar cell sealing film.

  A solar cell module is usually formed by laminating solar cells formed of polycrystalline silicon or the like with a solar cell sealing film such as an ethylene-vinyl acetate copolymer (EVA), and the both sides of the solar cell are further sunlit. It has a structure covered with a battery module protective sheet (protective member). In such a solar cell module, a front surface side transparent protective member, a solar cell sealing film, a solar battery cell, a solar cell sealing film, and a back surface side protective member are laminated in this order; -Manufactured by crosslinking and curing vinyl acetate copolymer (EVA).

  In order to perform the crosslinking and curing by the heating and pressurizing, a crosslinking agent such as an organic peroxide, various additives for imparting adhesiveness and long-term durability with a solar battery cell, etc. Addition has been proposed (see, for example, Patent Document 1). As described above, the solar cell sealing film is generally stored and transported in a state containing various additives such as an unreacted crosslinking agent and adhesive.

  However, a cross-linking agent or an additive contained in the solar cell sealing film may volatilize or change due to a change in the outside air temperature during transportation and storage of the solar cell sealing film or a reaction with moisture in the atmosphere. For this reason, when manufacturing a solar cell module, the desired hardening characteristic and adhesiveness as a solar cell sealing film may not be obtained. In addition, the modified additive itself is colored to reduce the light transmittance of sunlight, or corrodes the current collecting line of the solar cell module and hinders the transfer of electric charges, thereby improving the power generation efficiency of the solar cell. There was also a risk of lowering.

  For this reason, it has been attempted to suppress volatilization and reaction of the crosslinking agent and additives contained in the solar cell sealing film by packaging and storing and transporting the solar cell sealing film with a packaging sheet or the like.

JP 2007-281135 A

  However, the quality of the solar cell sealing film was not sufficiently retained even by the packaging sheet. Furthermore, even when the quality of the solar cell sealing film itself is maintained, the solar cell electrode corrodes while the solar cell module having the sealing layer formed using the solar cell sealing film is used. As a result, the power generation efficiency may decrease, or the color may change to cause poor appearance.

  The present inventor has found that this is because the metal component contained in the electrode of the solar battery cell reacts with the sulfur component. Furthermore, it has been found that this sulfur component is a component derived from a sealing layer that is not originally a member containing a sulfur component. And this sulfur component is a component contained in a packaging sheet or its adhesive tape for storing or transporting a solar cell sealing film for forming a sealing layer; the component is being stored or transported It was found that they were attached to the solar cell sealing film.

  The present invention has been made based on such knowledge, while suppressing the volatilization and alteration of the crosslinking agent and the like contained in the solar cell sealing film during storage and transportation; the sulfur component contained in the packaging member The present invention provides a package for storage or transportation of a solar cell sealing film, and a storage or transportation method, which can suppress adhesion to the solar cell sealing film. Thereby, the external appearance defect of a solar cell module and the fall of power generation efficiency are suppressed.

1st of this invention is related with the package body of the solar cell sealing film shown below.
[1] A solar cell sealing film and a packaging sheet for packaging the solar cell sealing film, and a content of elemental sulfur per unit volume of the packaging sheet is 1.1 × 10 ⁻³ μg / A package for storage or transportation of a solar cell sealing film, which is ³ mm ³ or less.
[2] The package further includes an adhesive tape that seals the opening of the package, and the content of elemental sulfur per unit area of the adhesive layer of the adhesive tape is 9.0 × 10 ^−2. The package for storage or transportation of the solar cell sealing film according to [1], which is μg / mm ² or less.
[3] The package further includes an adhesive tape that seals the opening of the package, and the content of elemental sulfur per unit volume of the adhesive layer of the adhesive tape is 4.5 × 10 ^−3. The package for storage or transportation of the solar cell sealing film according to [1] or [2], wherein the package is μg / mm ³ or less.
[4] The solar cell encapsulating film includes an ethylene-vinyl acetate copolymer as a main component, and the solar cell encapsulating film storage or transport packaging body according to any one of [1] to [3]. .
[5] The solar cell sealing film is for storage or transportation of the solar cell sealing film according to any one of [1] to [4], which is stacked on an electrode including a metal component of a solar battery cell. Packaging body.
[6] The packaging sheet for storing or transporting a solar cell sealing film according to any one of [1] to [5], wherein the packaging sheet contains a resin having a melting temperature of 80 to 160 ° C.
[7] The packaging sheet for storing or transporting a solar cell sealing film according to any one of [1] to [6], wherein the packaging sheet contains polyolefin.

The second of the present invention relates to a method for storing or transporting the solar cell sealing film described below.
[8] A method for storing or transporting a solar cell sealing film, wherein the solar cell sealing film has a sulfur element content per unit volume of 1.1 × 10 ⁻³ μg / mm ³ or less. A method for storing or transporting a solar cell encapsulating film, comprising: a step of obtaining a package by packaging with a sheet; and a step of storing or transporting the package in a dark place.
[9] The step of obtaining the package includes a step of sealing the opening of the package with an adhesive tape, and the content of elemental sulfur per unit area of the adhesive layer of the adhesive tape is 9.0 ×. The method for storing or transporting a solar cell sealing film according to [8], which is 10 ⁻² μg / mm ² or less.
[10] The step of obtaining the package includes a step of sealing the opening of the package with an adhesive tape, and the content of elemental sulfur per unit volume of the adhesive layer of the adhesive tape is 4.5 ×. The method for storing or transporting a solar cell sealing film according to [8], which is 10 ⁻³ μg / mm ³ or less.
[11] The step of obtaining the package includes storing or transporting the solar cell sealing film according to any one of [8] to [10], including a step of sealing the opening of the package by heat sealing. Method.
[12] The method for storing or transporting a solar cell sealing film according to any one of [9] to [11], wherein the solar cell sealing film contains an ethylene-vinyl acetate copolymer as a main component.

  According to the present invention, it is possible to suppress adhesion of a sulfur component contained in a packaging member to a solar cell sealing film while suppressing volatilization and alteration of a crosslinking agent or the like during storage and transportation of the solar cell sealing film. it can. Thereby, the external appearance defect of a solar cell module and the fall of power generation efficiency are suppressed.

It is a schematic diagram which shows an example of the preparation methods of the package in embodiment of this invention. It is sectional drawing which shows an example of a structure of a solar cell module. It is a top view which shows an example of a structure of the light-receiving surface and back surface of a solar cell module.

1. Solar cell sealing film The solar cell sealing film contains a resin as a main component, a crosslinking agent, and various additives such as an adhesion-imparting agent as required.

  Examples of the resin as the main component include an ethylene homopolymer and a copolymer of ethylene and at least one copolymer component other than ethylene. The ethylene copolymer may be a random copolymer of ethylene and a copolymer component, may be a block copolymer, and is preferably a random copolymer. Examples of the copolymer component in the ethylene copolymer include α-olefins having 3 to 20 carbon atoms other than ethylene, cyclic olefins, vinyl acetate, and the like.

  Examples of α-olefins having 3 to 20 carbon atoms other than ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1 -Dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like are included.

  Examples of cyclic olefins include norbornene derivatives, tricyclo-3-decene derivatives, tricyclo-3-undecene derivatives, tetracyclo-3-dodecene derivatives, pentacyclo-4-pentadecene derivatives, pentacyclopentadecadiene derivatives, pentacyclo-3-pentadecenes. Derivatives, pentacyclo-4-hexadecene derivatives, pentacyclo-3-hexadecene derivatives, hexacyclo-4-heptadecene derivatives, heptacyclo-5-eicosene derivatives, heptacyclo-4-eicosene derivatives, heptacyclo-5-heneicosene derivatives, octacyclo-5-docosene derivatives , Nonacyclo-5-pentacocene derivative, nonacyclo-6-hexacocene derivative, cyclopentadiene-acenaphthylene adduct, 1,4-methano-1,4,4a, 9a-te La hydro fluorene derivatives, 1,4-methano -1,4,4a, 5,10,10a hexa hydro anthracene derivatives, and the like cycloalkylene derivative having 3 to 20 carbon atoms. Among them, tetracyclo [4.4.0.12,5.17,10] -3-dodecene derivatives and hexacyclo [6.6.1.13, 6.110, 13.02, 7.09,14] -4 -Heptadecene derivatives are preferred, and tetracyclo [4.4.0.12,5.17,10] -3-dodecene is particularly preferred.

  Copolymerization components (α-olefin, cyclic olefin and vinyl acetate) in the ethylene copolymer may be used singly or in combination of at least two or more.

  The copolymer component in the ethylene copolymer may further contain an ethylenically unsaturated silane compound or a radically polymerizable unsaturated compound.

  A conventionally well-known thing can be used for an ethylenically unsaturated silane compound, and there is no restriction | limiting in particular. Examples of ethylenically unsaturated silane compounds include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxy-ethoxysilane), γ-glycidoxypropyl-triprytrimethoxysilane, γ-aminopropyltriethoxy Silane, γ-methacryloxypropyltrimethoxysilane and the like are included.

  Examples of radically polymerizable unsaturated compounds include hydroxyl group-containing ethylenically unsaturated compounds, amino group-containing ethylenically unsaturated compounds, epoxy group ethylenically unsaturated compounds, aromatic vinyl compounds, unsaturated carboxylic acids or their derivatives, vinyl Examples include ester compounds, vinyl chloride, carbodiimide compounds, and the like.

  The resin as the main component is particularly preferably ethylene-vinyl acetate copolymer (EVA) from the viewpoints of high transparency, flexibility and durability, and excellent compatibility with various additives.

  The ethylene-vinyl acetate copolymer (EVA) may preferably be a random copolymer. The content of the structural unit derived from vinyl acetate in the ethylene-vinyl acetate copolymer is preferably 20 to 38% by weight, more preferably 24 to 36% by weight, still more preferably 26 to 34% by weight. is there. However, the total of the content of structural units derived from ethylene and the content of structural units derived from vinyl acetate is 100% by weight.

  The crosslinking agent can improve the heat resistance and weather resistance of the solar cell encapsulating film by crosslinking the ethylene-vinyl acetate copolymer (EVA). As such a cross-linking agent, an organic peroxide that generates radicals at 100 ° C. or higher is generally preferred. In particular, considering the stability at the time of blending, an organic peroxide having a decomposition temperature of 10 hours half-life of 70 ° C. or higher. Oxides are more preferred.

  Examples of such organic peroxides include 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 3-di-t-butyl peroxide, t-dicumyl peroxide, 2 , 5-Dimethyl-2,5-di (t-butylperoxy) hexyne, dicumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, n-butyl-4,4-bis ( t-butylperoxy) butane, 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) 3, 3,5-trimethylcyclohexane, t-butyl peroxybenzoate, benzoyl peroxide and the like are included.

  The content of the crosslinking agent is preferably 0.1 to 3.0 parts by weight and more preferably 0.2 to 2.0 parts by weight with respect to 100 parts by weight of the ethylene-vinyl acetate copolymer. preferable.

  The solar cell sealing film used in the present invention may further contain various additives such as an adhesion-imparting agent and a crosslinking aid as necessary.

  The adhesion-imparting agent can improve the adhesion of the solar cell sealing film to the power generation element. The adhesiveness imparting agent is preferably a silane coupling agent. Examples of silane coupling agents include γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tris- (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, β- ( 3,4-ethoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane and N-β- (aminoethyl) ) -Γ-aminopropyltrimethoxysilane and the like. The content of these silane coupling agents is usually preferably 0.1 to 3.0 parts by weight, and preferably 0.2 to 1.5 parts by weight with respect to 100 parts by weight of the ethylene-vinyl acetate copolymer. It is more preferable that

  The crosslinking assistant can increase the crosslinking reactivity of the ethylene-vinyl acetate copolymer and improve the durability of the solar cell sealing film. Examples of the crosslinking aid include trifunctional crosslinking aids such as triallyl isocyanurate and triallyl isocyanate, and trimethylolpropane triacrylate.

  Examples of other additives include colorants, ultraviolet absorbers, anti-aging agents, anti-discoloring agents, heat-resistant stabilizers, ultraviolet (weather resistant) stabilizers, and light stabilizers.

  Examples of colorants include inorganic pigments such as metal oxides and metal powders; organic pigments such as azo-based, phthalocyanine-based, and acidic or basic dye-based lakes.

  Examples of ultraviolet absorbers include benzophenone series such as 2-hydroxy-4-octoxybenzophenone and 2-hydroxy-4-methoxy-5-sulfobenzophenone; 2- (2′-hydroxy-5-methylphenyl) benzo Benzotriazole systems such as triazole; hindered amine systems such as phenyl salicylate and pt-butylphenyl salicylate are included.

  Anti-aging agents include amines, phenols, bisphenyls and hindered amines, such as di-t-butyl-p-cresol and bis (2,2,6,6-tetramethyl-4- Piperazil) sebacate and the like. Examples of the ultraviolet light (weather resistance) stabilizer include dibutylhydroxytoluene. Further, hydroquinone, hydroquinone monomethyl ether, p-benzoquinone, methylhydroquinone, and the like may be included in improving the stability of the ethylene-vinyl acetate copolymer.

  Such a solar cell encapsulating film is a method in which a resin composition containing the above-described components is melt-kneaded using a T-die extruder, extruded as a molten resin sheet, and then cooled and solidified (melt extrusion method). Or a method (calender method) or the like in which a molten resin is sandwiched between a plurality of rollers and rolled into a film shape. The thickness of the solar cell sealing film is, for example, about 100 μm to 2000 μm.

  The solar cell sealing film may be embossed on the surface in terms of improving cushioning and deaeration in the heat curing step.

2. Package of Solar Cell Sealing Film A solar cell sealing film is stored or transported as a package packaged with a packaging sheet after being laminated in a roll shape or a sheet shape cut into a predetermined size. This is for suppressing volatilization and reaction of a volatile crosslinking agent (for example, an organic peroxide) or an additive (for example, a silane coupling agent) contained in the solar cell sealing film. The package may be sealed with an adhesive tape from the standpoint of enhancing the sealing property.

  The packaging sheet preferably contains a polyolefin resin from the viewpoint of good gas barrier properties and water vapor barrier properties. The polyolefin resin may be a homopolymer or a copolymer containing other copolymer components. Examples of polyolefin resins include polyethylene resins (including high density polyethylene and low density polyethylene), polypropylene resins, ethylene-α olefin copolymer resins, and the like.

  The polyolefin resin contained in the packaging sheet preferably has heat sealability. The heat seal temperature (melting temperature) of the polyolefin resin is preferably 80 to 160 ° C. because it does not melt during transportation and is easy to heat seal. From the viewpoint of having good gas barrier properties and heat sealing properties, low density polyethylene, polypropylene and the like are more preferable.

  The packaging sheet may contain a resin other than the polyolefin resin. Examples of other resins include polyester.

  The packaging sheet preferably contains as little sulfur component as possible. When the packaging sheet contains a large amount of sulfur, sulfur element adheres to the solar cell sealing film; when the solar cell module sealing layer is formed using the solar cell sealing film to which sulfur element adheres, the sealing layer In the use of the solar cell module, the metal component contained in the solar cell electrode gradually reacts with the sulfur component contained in the sealing layer to corrode or discolor. Because.

The content of the elemental sulfur per unit volume of the packaging sheet is 1.1 × 10 ⁻³ μg / mm ³ or less, and it is more preferable that the elemental sulfur is not substantially contained. The content of elemental sulfur can be measured by a general sulfur component measurement method, and can be specifically measured by energy dispersive X-ray fluorescence (EDX) measurement.

The packaging sheet preferably has high gas barrier properties and water vapor barrier properties from the viewpoint of suppressing the volatilization of the crosslinking agent and additives. The moisture permeability at a thickness of 100 μm of the packaging sheet is preferably 10 g / (24 hr · m ² ) or less, and the moisture permeability at a thickness of 100 μm is more preferably 1 g / (24 hr · m ² ) or less. The moisture permeability can be measured at a temperature of 40 ° C. and a relative humidity of 90% in accordance with JIS Z 0208.

  The thickness of the packaging sheet is preferably 50 to 200 μm in consideration of the strength of the sheet, handleability, gas barrier properties, and the like.

  The packaging sheet packed with the solar cell sealing film may be further sealed with an adhesive tape. The pressure-sensitive adhesive tape includes a base film and a pressure-sensitive adhesive layer.

  The pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape contains a pressure-sensitive adhesive resin and a tackifier. Examples of the adhesive resin include known acrylic, rubber-based, and silicon-based adhesive resins.

  Acrylic and rubber-based adhesive resins are obtained by crosslinking a main polymer with a crosslinking agent. Examples of the rubber-based polymer contained in the adhesive resin include an isobutylene polymer. Examples of the acrylic copolymer contained in the adhesive resin include an acrylic copolymer containing a repeating unit derived from n-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, ethyl acrylate, or the like. included. The copolymer component in the acrylic copolymer is a component having a double bond in the molecule, specifically, vinyl acetate, acrylonitrile, styrene or the like.

  Examples of the tackifier include tackifiers such as rosin and petroleum resin.

  After the adhesive tape is obtained, for example, by mixing an adhesive resin as a main agent, a tackifier, and a solvent for adjusting the viscosity as necessary; the coating liquid is made of paper, plastic, etc. It can obtain by apply | coating and drying on the base material.

  These adhesive resins often contain a sulfur component for obtaining adhesiveness. However, the component of the adhesive layer easily adheres to the solar cell sealing film during storage or transportation of the solar cell sealing film; and further, when the sulfur component of the adhered components contacts the metal component of the battery cell electrode, Causes corrosion or discoloration of the electrode. In order to suppress this corrosion and discoloration, it is preferable to reduce the content of the sulfur component in the adhesive layer.

Specifically, the content of elemental sulfur per unit area of the adhesive layer is preferably 9.0 × 10 ⁻² μg / mm ² or less. The content of elemental sulfur per unit volume of the adhesive layer is preferably 4.5 × 10 ⁻³ μg / mm ³ or less.

  Examples of the adhesive resin having a small sulfur component include an acrylic adhesive resin, preferably an acrylic adhesive resin using an organic peroxide as a crosslinking agent. On the other hand, rubber-based adhesive resins often contain many sulfur components. Examples of the pressure-sensitive adhesive tape having an adhesive resin with a low sulfur component as the pressure-sensitive adhesive layer include trade name: Danbron 30 (manufactured by Nitto Denko Corporation), trade name: Orientien tape (manufactured by Sekisui Chemical Co., Ltd.), and the like.

  The thickness of the adhesive layer is, for example, preferably 5 to 50 μm, and more preferably 10 to 30 μm. This is because if the adhesive layer is too thin, it is difficult to obtain desired adhesiveness, and if the adhesive layer is too thick, the amount of sulfur contained in the adhesive layer increases.

  The package can be produced by any method. An example of a method for manufacturing a package is a method of packing a laminate of solar cell sealing films with a packaging sheet, and then fixing the opening of the packaging sheet with a heat seal or an adhesive tape; a bottom-sealed bag-shaped packaging sheet In addition, a method of sealing the opening with a heat seal or an adhesive tape after putting the laminated body of the solar cell sealing film is included.

  FIG. 1 is a schematic view showing an example of a method for producing a package 10 containing a sheet-like solar cell sealing film. As shown in FIG. 1A, first, a bottom-sealed bag-shaped packaging sheet 12 is prepared, and a solar cell sealing film 14 is put therein. Next, as shown in FIG. 1B, the opening 12A of the packaging sheet 12 is bent so as not to overlap with the solar cell sealing film as much as possible. Thereafter, as shown in FIG. 1C, the folded portion is sealed with the adhesive tape 16, whereby the package 10 can be obtained. The pressure-sensitive adhesive tape is attached so as to be positioned on a portion where the end of the solar cell sealing film 14 and the packaging sheet 12 overlap.

  The obtained package is preferably transported or stored in a dark place. The dark place is preferably a place not exposed to direct sunlight at 30 ° C. or lower, preferably 25 ° C. or lower. It is preferable that the package is stored or transported by being further packed in a packaging container such as cardboard from the viewpoint of improving heat insulation.

3. Solar cell module The solar cell sealing film stored and transported is preferably used as a sealing member (sealing layer) for solar cells in the solar cell module. Types of solar cells include silicon-based (for example, crystalline silicon-based, thin-film silicon-based), compound-based (for example, CIGS-based), organic-based (for example, dye-sensitized system), and the like. An example in which the solar battery cell is silicon will be described below.

(1) Crystalline Silicon Solar Cell Module FIG. 2 is a cross-sectional view showing an example of the configuration of a crystalline silicon solar cell module 20. As shown in FIG. 2, the solar cell module 20 includes a plurality of crystalline silicon solar cells 22 electrically connected by an interconnector 29, a pair of front surface side transparent protective members 24 sandwiching the solar cell modules 22, and a rear surface. A side protection member 26 is provided, and a sealing layer 28 is filled between the protection member and the plurality of solar cells 22. The sealing layer 28 is obtained by heat-curing the solar cell sealing film in the present invention, and is in contact with the electrodes formed on the light receiving surface and the back surface of the solar cell 22. The electrode is a current collecting member formed on each of the light receiving surface and the back surface of the solar battery cell 22 and includes a power collecting wire, a tabbed bus, a back electrode layer, and the like which will be described later.

  FIG. 3 is a plan view showing an example of the configuration on the light receiving surface 22 </ b> A and the back surface 22 </ b> B of the solar battery cell 22. As shown in FIG. 3 (A), the light receiving surface 22A of the solar battery cell 22 is connected to the interconnector 29 while collecting a large number of linearly collected current collectors 32 and the current collectors 32. And a tabbed bus bar (bus bar) 34A.

  As shown in FIG. 3 (B), a conductive layer (back electrode) 36 is formed on the entire back surface 22B of the solar battery cell 22 to collect charges from the conductive layer 36 and to interconnector 29. A bus bar with a tab (bus bar) 34B is formed.

  The line width of the collector line 32 is, for example, about 0.1 mm; the line width of the tabbed bus 34A is, for example, about 2-3 mm; and the line width of the tabbed bus 34B is, for example, about 5-7 mm. is there. The thickness of the power collection line 32, the tab-attached bus 34A, and the tab-attached bus 34B is, for example, about 20 to 50 μm.

  The current collector 32, the tabbed bus 34A, and the tabbed bus 34B preferably contain a highly conductive metal. Examples of such highly conductive metals include gold, silver, copper, and the like. From the viewpoint of high conductivity and high corrosion resistance, silver, silver compounds, alloys containing silver, and the like are preferable.

  The conductive layer 36 contains not only a highly conductive metal but also a highly light reflective component such as aluminum from the viewpoint of improving the photoelectric conversion efficiency of the solar battery cell by reflecting light received by the light receiving surface. Is preferred.

  The current collector 32, the tabbed bus 34 </ b> A, the tabbed bus 34 </ b> B, and the conductive layer 36 are made of, for example, screen printing using a conductive material paint containing the highly conductive metal on the light receiving surface 22 </ b> A or the back surface 22 </ b> B of the solar battery cell 22. After being applied to a coating thickness of 50 μm by drying, it is dried and, if necessary, formed by baking at, for example, 600 to 700 ° C.

Specific examples of the conductive paint on the light-receiving side include product names: Dupont Solaret ^R product numbers: PV135 (silver), PV145 (silver), PV142 (silver), and the like. Examples of the conductive paint of the conductive layer 36 include a conductive paint containing aluminum as a main component and further adding a highly conductive metal. A specific example is a product name of Dupont Solaret ^R : PV202 (silver / aluminum). ), PV322 (aluminum), PV34x (aluminum), and the like.

  Since the surface side transparent protective member 24 is disposed on the light receiving surface side, it needs to be transparent. Examples of the surface side transparent protective member 24 include a transparent glass plate and a transparent resin film. On the other hand, the back surface side protection member 26 does not need to be transparent, and the material is not particularly limited. Examples of the back surface side protection member 26 include a glass substrate and a plastic film.

  The solar cell module 20 can be obtained by any manufacturing method. The solar cell module 20 is, for example, a step of obtaining a laminate in which the back surface side protective member 26, the solar cell sealing film, the plurality of solar cells 22, the solar cell sealing film, and the front side transparent protective member 24 are stacked in this order; The laminate can be obtained by a step of heating and pressurizing the laminate with a laminator or the like; and a step of heating the laminate as necessary.

  The heating and pressing conditions may be, for example, 130 ° C., 3 minutes under vacuum, and 4 minutes under pressure, depending on the type of solar cell sealing film. The heat treatment conditions can be, for example, 150 ° C. and 40 minutes, mainly for the purpose of crosslinking the solar cell sealing film.

(2) Thin-film silicon-based (amorphous silicon-based) solar cell module The thin-film silicon-based solar cell module is: 1) front side transparent protective member (glass substrate) / thin film solar cell / sealing layer / back side protective member. It may be a laminate of this order; 2) a laminate of a front side transparent protective member / sealing layer / thin film solar cell / sealing layer / back side protection member in this order. The front surface side transparent protective member, the back surface side protective member and the sealing layer are the same as in the case of 1) described above.

The thin film photovoltaic cell in the aspect of 1) includes, for example, a transparent electrode layer / pin type silicon layer / back electrode layer in this order. Examples of the transparent electrode layer include semiconductor oxides such as In ₂ O ₃ , SnO ₂ , ZnO, Cd ₂ SnO ₄ , ITO (In ₂ O ₃ with Sn added). The back electrode layer includes, for example, a silver thin film layer. Each layer is formed by a plasma CVD (chemical vapor deposition) method or a sputtering method.

  A sealing layer is arrange | positioned so that a back surface electrode layer (for example, silver thin film layer) may be contact | connected. Since the transparent electrode layer is formed on the front surface side transparent protective member, the sealing layer is often not disposed between the front surface side protective member and the transparent electrode layer.

  The thin-film solar cell in the aspect of 2) includes, for example, a transparent electrode layer / pin type silicon layer / metal foil, or a metal thin film layer (for example, a silver thin film layer) disposed on a heat-resistant polymer film in this order. Including. Examples of the metal foil include stainless steel foil. Examples of the heat resistant polymer film include a polyimide film.

  The transparent electrode layer and the pin type silicon layer are formed by the CVD method or the sputtering method as described above. That is, the pin-type silicon layer is formed on a metal foil or a metal thin film layer disposed on a heat-resistant polymer film; and the transparent electrode layer is formed on a pin-type silicon layer. Moreover, the metal thin film layer arrange | positioned on a heat resistant polymer film can also be formed by CVD method or a sputtering method.

  In this case, the sealing layer is disposed between the transparent electrode layer and the front surface side protective member; and between the metal foil or the heat resistant polymer film and the back surface side protective member. The sulfur component mixed in the sealing layer may permeate the heat-resistant polymer film and corrode the metal thin film layer of the thin film solar cell.

  Thus, the sealing layer obtained from the solar cell sealing film is in contact with electrodes such as a current collecting line, a tabbed bus bar, and a conductive layer of the solar battery cell. ADVANTAGE OF THE INVENTION According to this invention, adhesion | attachment to the solar cell sealing film of the sulfur component contained in a packaging member can be suppressed during a preservation | save and conveyance. For this reason, the sulfur component is not contained in the sealing layer obtained from the solar cell sealing film, and the metal component contained in the electrode of the solar battery cell is contained in the sealing layer during use of the solar cell module. Slow reaction with ingredients to inhibit corrosion and discoloration. Thereby, the external appearance defect of a solar cell module and the fall of power generation efficiency are suppressed.

  The present invention is preferably applied to a method for storing or transporting a solar cell sealing film that is a sealing layer (particularly, a sealing layer on the back surface side) of a laminated glass type solar cell module particularly suitable for building materials. Specifically, the solar cell module for building materials is a module used for the wall surface of a building, the ceiling of a hollow hole, or the like. These solar cell modules for building materials are because the back surface is easily visible from inside the building, and the appearance defects due to discoloration of the solar cells are conspicuous through the glass which is the back surface side protection member.

Example 1
A solar cell sealing film (manufactured by Mitsui Chemicals Fabro Co., Ltd., trade name: Solar Eva (registered trademark), product number: SC50) was cut into a sheet of 300 × 300 cm.
After putting the sheet-shaped solar cell sealing film into a packaging bag of a 150 μm-thick low-density polyethylene film (manufactured by Hayashi Sangyo Co., Ltd., trade name: LL bottom seal flat bag), the opening of the packaging bag is formed. It was bent (see FIGS. 1A and 1B above). This packaging bag is obtained by processing a low density polyethylene film into a bag shape by heat sealing.
Next, the folded portion of the packaging bag was sealed with an adhesive tape (manufactured by Nitto Denko Corporation, trade name: Dunbron 30) to obtain a package (see FIG. 1C). The adhesive tape was affixed so that it might be located on the site | part with which the edge part of the solar cell sealing film and the low density polyethylene film have overlapped.
Disperse the sulfur content per unit area contained in the adhesive layer of the adhesive tape and the sulfur content contained in the packaging sheet of the part where the adhesive tape is affixed with a device (JSX-3203EV) manufactured by JEOL. It was measured by type (ED) fluorescent X-ray measurement. The results are shown in Table 1.

(Example 2)
A package is obtained in the same manner as in Example 1 except that an adhesive tape (Sekisui Chemical Co., Ltd., product name: Oriente tape) is used instead of the adhesive tape (Nitto Denko Co., Ltd., product name: Danbron 30). Obtained.

(Comparative Example 1)
Example 1 was used except that an adhesive tape (manufactured by Nitto Denko Corporation, trade name: paper adhesive tape No. 7210) was used instead of the adhesive tape (manufactured by Nitto Denko Corporation, trade name: Danbron 30). A package was obtained.

  The packaging bodies obtained in Examples 1-2 and Comparative Example 1 were stored at 40 ° C. for 35 days. The crosslinking rate of the solar cell sealing film after storage and the adhesive force with glass were evaluated. Furthermore, the presence or absence of discoloration of the electrode part of the photovoltaic cell when the solar cell sealing film after storage was laminated and laminated with the photovoltaic cell was evaluated. These results are shown in Table 1.

1. Crosslinking rate The solar cell encapsulating film laminated in a sheet shape was cut into a predetermined size to obtain a solar cell encapsulating sheet. Thereafter, the solar cell encapsulating sheet was heated to 150 ° C. under pressure for 20 minutes using a compression molding machine to prepare a crosslinked sheet. About 1 g of this cross-linked sheet was weighed with a precision balance, immersed in 100 ml of xylene, heated at 110 ° C. for 24 hours, and then filtered through a wire mesh to collect insoluble matter. After this crosslinked sheet was dried, the crosslinking rate was calculated by weighing with a precision balance.
Crosslinking rate (%) = [weight of sample after drying (g) / weight of sample collected (g)] × 100

2. Adhesive strength with glass The solar cell sealing film laminated | stacked on the transparent glass plate which is a surface side protection member on the sheet form was cut | judged to the predetermined magnitude | size, and the solar cell sealing sheet was obtained. This solar cell encapsulating sheet was laminated using a solar cell module manufacturing laminator at 160 ° C., a vacuum of 3 minutes, and a pressure of 4 minutes, and further held at 160 ° C. for 7 minutes. The adhesive force between the transparent glass plate and the solar cell encapsulating sheet was evaluated. The adhesive force was measured using a tensile test machine under the conditions of peeling rate: 300 mm / min, peeling width (sample width): 1.0 cm, peeling angle: 180 °.

3. Discoloration evaluation of solar cells (polycrystalline silicon) 1
First, as a solar cell polycrystalline silicon, conductive paint A (Dupont Solamet ^R, Part: PV145) in the light-receiving surface side; conductive paint B on the back side (Dupont Solamet ^R, Part: PV202) of each After coating and drying by a known method so that the film thickness becomes 40 μm, baking was performed to produce a cell in which a conductive layer was formed.

  Subsequently, the aspect battery module was produced using each solar cell sealing film of Example 1, Example 2, and Comparative Example 1. Specifically, glass / solar battery sealing film / solar battery cell / solar battery sealing film / glass are laminated in this order to obtain a laminated body; the obtained laminated body is laminator at 150 ° C., A solar cell module was produced by heating and pressing for 22 minutes. For each of Example 1, Example 2, and Comparative Example 1, seven of these solar cell modules were produced. In the produced solar cell module, the presence or absence of discoloration of the light receiving surface and the back surface conductive layer of the solar cell was visually observed.

  For all of the seven solar cell modules, the case where no discoloration was observed compared to the color of the conductive layer of the solar cell before the solar cell module fabrication was evaluated as good (◯); three or more of the seven solar cells In the module, the case where discoloration of the solar battery cell was observed was regarded as defective (x).

4). Discoloration evaluation of solar cells (thin film silicon) 2
First, as a thin-film silicon solar cell, a SnO ₂ transparent conductive film is formed on a white glass substrate by a thermal CVD method; a single-structure amorphous silicon semiconductor film having a pin element structure is publicly known on the SnO ₂ transparent conductive film. A back electrode made of a ZnO transparent conductive film and a silver thin film (thickness 0.003 μm) was formed on the amorphous silicon semiconductor film by known DC magnetron sputtering.

  Subsequently, the aspect battery module was produced using each solar cell sealing film of Example 1, Example 2, and Comparative Example 1. Specifically, a laminate in which a solar cell sealing film and glass are sequentially laminated on the silver thin film side of a thin film silicon solar cell is obtained; using the obtained laminate, the same as in the discoloration evaluation 1 The solar cell module was produced according to the procedure. For each of Example 1, Example 2, and Comparative Example 1, seven of these solar cell modules were produced.

  Similar to the discoloration evaluation 1, the presence or absence of discoloration of the solar cells was visually observed and evaluated.

  As shown in Table 1, with respect to the crosslinking rate of the solar cell sealing film and the adhesive strength with glass, both Examples 1 and 2 and Comparative Example 1 are equivalent, and there is almost no decrease compared to storage. It was. As a reference example, the result of storage in the same manner as in Example 1 except that the sheet was not wrapped in a packaging sheet and stored in the air at room temperature. It decreased to about 75%, and it was found that the crosslinking property was lost.

  On the other hand, about the discoloration of the photovoltaic cell, the result different in Examples 1-2 and the comparative example 1 was obtained. That is, in the solar battery cell using the solar battery sealing film of Examples 1-2, no discoloration of the electrode was observed; in the solar battery cell using the solar battery sealing film of Comparative Example 1, An electrode discoloration was observed. Compared with the solar cell sealing film of Comparative Example 1, the solar cell sealing films of Examples 1 and 2 have very little adhesion of the sulfur component of the adhesive layer of the adhesive tape, and are contained in the electrodes of the solar cells. This is thought to be because it hardly reacted with the components.

  According to the storage or transportation method of the present invention, while suppressing the volatilization and alteration of the crosslinking agent and the like contained in the solar cell sealing film during storage and transportation; the solar cell sealing film of the sulfur component contained in the packaging member Adhesion to can be suppressed. Thereby, the external appearance defect of a solar cell module and the fall of power generation efficiency can be suppressed. The storage or transport method of the present invention is not limited to silicon-based solar cell modules, and can be widely applied to storage or transport methods of solar cell sealing films of various solar cell modules other than silicon-based solar cells.

DESCRIPTION OF SYMBOLS 10 Package 12 Packaging sheet 12A Opening 14 Solar cell sealing film 16 Adhesive tape 20 Solar cell module 22 Solar cell 24 Front surface side transparent protective member 26 Back surface side protective member 28 Sealing layer 29 Interconnector 32 Current collector 34A, 34B Busbar with tab 36 Conductive layer

Claims (12)

A solar cell sealing film;
A packaging sheet for packaging the solar cell sealing film,
A package for storage or transportation of a solar cell sealing film, wherein the content of elemental sulfur per unit volume of the packaging sheet is 1.1 × 10 ⁻³ μg / mm ³ or less. The package further includes an adhesive tape that seals an opening of the package,
The content of elemental sulfur per unit area of the adhesive tape of the adhesive layer is 9.0 × 10 ^-2 μg / mm ² or less, for storage or transport of the solar cell sealing film according to claim 1 Packaging body. The package further includes an adhesive tape that seals an opening of the package,
The content of sulfur element per unit volume of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is 4.5 × 10 ⁻³ μg / mm ³ or less, for storage or transportation of the solar cell sealing film according to claim 1. Packaging body.   The said solar cell sealing film is a package for the preservation | save or transportation of the solar cell sealing film as described in any one of Claims 1-3 which contains an ethylene-vinyl acetate copolymer as a main component.   The said solar cell sealing film is a package for the preservation | save or transportation of the solar cell sealing film as described in any one of Claims 1-4 laminated | stacked on the electrode containing the metal component of a photovoltaic cell.   The said packaging sheet is a package for the preservation | save or conveyance of the solar cell sealing film as described in any one of Claims 1-5 containing resin whose melting temperature is 80-160 degreeC.   The said packaging sheet is a package for the preservation | save or conveyance of the solar cell sealing film as described in any one of Claims 1-6 containing polyolefin. A method for storing or transporting a solar cell sealing film,
A step of obtaining a package by packaging the solar cell sealing film with a packaging sheet having a sulfur element content per unit volume of 1.1 × 10 ⁻³ μg / mm ³ or less;
Storing or transporting the package in a dark place; and
A method for storing or transporting a solar cell sealing film. The step of obtaining the package includes a step of sealing the opening of the package with an adhesive tape,
The method for storing or transporting a solar cell sealing film according to claim 8, wherein the content of the elemental sulfur per unit area of the adhesive layer of the adhesive tape is 9.0 x ^10-2 µg / mm ² or less. The step of obtaining the package includes a step of sealing the opening of the package with an adhesive tape,
The method for preserving or transporting a solar cell sealing film according to claim 8, wherein the content of elemental sulfur per unit volume of the adhesive layer of the adhesive tape is 4.5 x 10 ^-3 µg / mm ³ or less.   The method for storing or transporting the solar cell sealing film according to claim 8, wherein the step of obtaining the package includes a step of sealing the opening of the package by heat sealing. The method for storing or transporting a solar cell sealing film according to any one of claims 9 to 11, wherein the solar cell sealing film contains an ethylene-vinyl acetate copolymer as a main component.

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