JP2010206010A - Protection sheet for solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protection sheet for a solar cell module, which has a fluorine-containing coat layer with superior steam barrier and wettability. <P>SOLUTION: (1) The protection sheet for the solar cell module includes a base sheet and the fluorine-containing resin coat layer laminated on at least one surface of the base sheet, wherein ions are implanted in the fluorine-containing resin coat sheet. (2) The protection sheet for the solar cell module described in the (1) is characterized in that one or more selected out of He, Ar, Kr, N<SB>2</SB>, and O<SB>2</SB>are ion-implanted in the fluorine-containing resin coat layer. (3) The protection sheet for the solar cell module described in the (1) or the (2) is characterized in that the base sheet is a resin sheet. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a protective sheet for a solar cell module used as a surface protective sheet or a back surface protective sheet of a solar cell module.

A solar cell module, which is a device that converts solar light energy into electrical energy, has attracted attention as a system that can generate power without discharging carbon dioxide.
As schematically shown in FIG. 3, a general solar cell module includes a front sheet (light transmissive surface protective sheet) 10, a back sheet (back surface protective sheet) 20, a sealing material (filling layer) 30, and the sun. The battery cell 40 is schematically configured. The front sheet 10 may have a base material made of a glass plate.

  In the present specification and claims, the front sheet (light transmissive surface protective sheet) 10 and the back sheet (back surface protective sheet) 20 are collectively referred to as “protective sheet”.

  In order to give the solar cell module the weather resistance and durability that can withstand long-term use outdoors and indoors, the solar cell 40 and the sealing material 30 are protected from wind and rain, moisture, dust, mechanical impact, etc. It is necessary to keep the inside of the solar cell module sealed from the outside air completely. For this reason, it is calculated | required that the said solar cell module protective sheets 10 and 20 are excellent in a weather resistance.

  As a structure of a general protective sheet for a solar cell module, there is one obtained by laminating a fluorine-containing resin coat layer for imparting weather resistance to a base sheet. As the base sheet, a resin sheet having electrical insulation or an aluminum sheet having excellent gas barrier properties is frequently used (see Patent Document 1). However, when the said aluminum sheet is used as a base material sheet, since the said solar cell module protective sheet does not have light transmittance, it is not used as the front sheet | seat 10, but is used as the back sheet | seat 20. FIG.

International Publication No. 2007/010706 Pamphlet

  Since the fluorine-containing resin coating layer in the conventional protective sheet for solar cell module has low water vapor barrier property (high water vapor permeability), the permeated water vapor contacts the base material sheet, and is often used as the base material sheet. There is a problem that the resin sheet such as hydrolyzes. When the hydrolysis of the base sheet proceeds, the protective sheet for the solar cell module deteriorates, water vapor or the like enters the solar cell module, and the functions of the sealing material and the solar cell are impaired.

  Moreover, since the wettability of the surface of the fluorine-containing resin coating layer laminated on the substrate sheet is low, there is a problem that the label is easily peeled off even if a label is attached to the surface for the purpose of indication of specifications. Furthermore, for the same reason, there is a problem that it is difficult to print or print on the surface of the fluorine-containing resin coat layer.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the protective sheet for solar cell modules which has a fluorine-containing resin coat layer excellent in water vapor | steam barrier property and wettability.

In order to achieve the above object, the present invention employs the following configuration.
That is, the present invention includes (1) a base sheet and a fluorine-containing resin coat layer laminated on at least one surface of the base sheet, and the fluorine-containing resin coat layer is ion-implanted. A protective sheet for a solar cell module. (2) One or more types selected from He, Ar, Kr, N ₂ , and O ₂ are ion-implanted in the fluorine-containing resin coat layer. For solar cell module according to (1) (3) The solar cell module protective sheet according to (1) or (2), wherein the base sheet is a resin sheet.

  ADVANTAGE OF THE INVENTION By this invention, the protective sheet for solar cell modules which has a fluorine-containing resin coat layer excellent in water vapor | steam barrier property and wettability can be provided.

The schematic diagram which showed the cross section of the 2 layer structure of the protection sheet for solar cell modules of this invention The schematic diagram which showed the cross section of the 4 layer structure of the protection sheet for solar cell modules of this invention Schematic diagram showing the configuration of the solar cell module Configuration diagram showing outline of plasma ion implantation system

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 includes a base sheet 24 and a fluorine-containing resin coat layer 22 laminated on at least one surface of the base sheet 24, and the fluorine-containing resin coat layer 22 of the present invention shown in FIG. The contained resin coat layer 22 is ion-implanted.

The fluorine-containing resin coat layer 22 may be laminated only on one surface of the substrate sheet 24 or may be laminated on both surfaces of the substrate sheet 24. In the fluorine-containing resin coat layer 22 laminated only on one surface of the substrate sheet 24, the fluorine-containing resin coat layer 22 is ion-implanted. Further, in the fluorine-containing resin coat layer 22 laminated on both surfaces of the base sheet 24, at least one of the two fluorine-containing resin coat layers 22 is ion-implanted. Yes.
In the solar cell module protective sheets 10 and 20 of the present invention, the fluorine-containing resin coat layer 22 is preferably laminated only on one surface of the base sheet 24. In this case, it becomes easier to laminate a support sheet 26 and the like, which will be described later, on the surface (back surface) opposite to the surface on which the fluorine-containing resin coat layer 22 is laminated.

The ion species implanted into the fluorine-containing resin coat layer 22 is preferably at least one selected from He, Ar, Kr, N ₂ , and O ₂ . The effects of the present invention can be enhanced when these ionic species are used.
More specifically, from the viewpoint of increasing the water vapor barrier property (reducing the water vapor permeability) of the solar cell module protective sheets 10 and 20 of the present invention, the ionic species is Ar, Kr, He, N ₂ , or O. ₂ is preferred.
On the other hand, from the viewpoint of increasing the wetting tension (wetting property) of the surface of the fluorine-containing resin coat layer 22 of the protective sheet 10 or 20 for the solar cell module of the present invention, the ionic species is Ar, Kr, He, N ₂ , or O ₂ is preferable and O ₂ is more preferable.
In the solar cell module protective sheets 10 and 20 of the present invention, the ionic species injected into the fluorine-containing resin layer 22 may be one kind alone, or two or more kinds may be combined.

Here, in this specification, the water vapor permeability of the protective sheet for the solar cell module is defined by the standard of ISO 15106-1: 2003. More specifically, the water vapor permeability is measured under the conditions of a permeation cell temperature of 40 ° C. and a relative humidity difference of 90% by a moisture sensitive sensor method in accordance with the above standard, and the result is evaluated as a water vapor barrier property. Is done.
In the present specification and claims, the wetting tension of the surface of the fluorine-containing resin coat layer is defined by the standard of ISO8296: 2003.

In the solar cell module protective sheet 10, 20 of the present invention, the water vapor transmission rate is preferably 3.3g ^/ (m 2 · 24h) or ^{less, 3.1g / (m 2 · 24h} ) , more preferably less, 2 More preferably, it is 0.9 g / (m ² · 24 h) or less.
It is preferable that the water vapor permeability is not more than the above value because the water vapor barrier property and the weather resistance of the solar cell module protective sheets 10 and 20 are further increased.

In the solar cell module protective sheets 10 and 20 of the present invention, the wetting tension of the surface of the fluorine-containing resin coat layer 22 is preferably 32.0 mN / m or more, more preferably 33.0 mN / m or more, and 34.0 mN. / M or more is more preferable.
It is preferable that the wetting tension is equal to or higher than the above value because the wettability of the surface of the fluorine-containing resin coat layer 22 is further increased and the adhesive strength of the label attached to the surface is increased.

Moreover, in the solar cell module protective sheets 10 and 20 of the present invention, the contact angle of the surface of the fluorine-containing resin coat layer 22 is preferably 84.0 degrees or less, more preferably 80.0 or less, and 78.0 degrees. The following is more preferable.
It is preferable that the contact angle is not more than the above value because the wettability of the surface of the fluorine-containing resin coat layer 22 is further increased and the adhesive strength of the label attached to the surface is further increased.
The contact angle is defined in JIS R3257: 1999 sessile drop method.

  In the solar cell module protective sheets 10 and 20 of the present invention, the fluorine-containing resin coat layer 22 is formed by applying a coating material containing a fluorine-containing resin to the base sheet 24 so as to form a coating film having a desired thickness. can do.

  The coating material containing the fluorine-containing resin is not particularly limited as long as it can form the fluorine-containing resin coat layer 22 after drying and cure, and can perform ion implantation treatment to be described later on the surface of the fluorine-containing resin coat layer 22. Any material that can be applied to the base sheet 24 can be used as long as it is dissolved in a solvent or dispersed in water.

The fluorine-containing resin contained in the paint is not particularly limited as long as it does not impair the effects of the present invention and contains a fluorine, but can be cross-linked by dissolving in the solvent (organic solvent or water) of the paint. Those are preferred.
Preferable examples of the fluorine-containing resin include chlorotrifluoroethylene such as LUMIFLON (trade name) manufactured by Asahi Glass Co., Ltd., CEFRAL COAT (trade name) manufactured by Central Glass Co., Ltd., and FLUONATE (trade name) manufactured by DIC Corporation. Polymers based on (CTFE), polymers based on tetrafluoroethylene (TFE) such as ZEFFLE (trade name) manufactured by Daikin Industries, Ltd .; I. Examples thereof include polymers having a fluoroalkyl group such as Zonyl (trade name) manufactured by du Pont de Nemours and Company, Unidyne (trade name) manufactured by Daikin Industries, Ltd., and polymers having a fluoroalkyl unit as a main component. Among these, from the viewpoints of weather resistance, pigment dispersibility, and the like, a polymer containing CTFE as a main component and a polymer containing TFE as a main component are more preferable. Most preferred.

The LUMIFLON (trade name) is an amorphous polymer containing CTFE, several kinds of specific alkyl vinyl ethers (VE), and hydroxyalkyl vinyl ethers as main structural units. A polymer having a monomer unit of hydroxyalkyl vinyl ether, such as LUMIFLON (trade name), is preferable because it is excellent in solvent solubility, cross-linking reactivity, substrate adhesion, pigment dispersibility, hardness, and flexibility.
The ZEFFLE (trade name) is a copolymer of TFE and an organic solvent-soluble hydrocarbon olefin, and in particular, when it has a hydrocarbon olefin having a highly reactive hydroxyl group, it is solvent-soluble and crosslinking reactivity. , Since it is excellent in substrate adhesion and pigment dispersibility.

  Examples of fluorine-containing resins contained in the paint include fluoroolefin polymers having a curable functional group. Specific examples thereof include TFE, isobutylene, vinylidene fluoride (VdF), hydroxybutyl vinyl ether, and others. Preferred are a copolymer comprising the above monomers, and a copolymer comprising TFE, VdF, hydroxybutyl vinyl ether and other monomers.

  Examples of the copolymerizable monomer in the fluorine-containing resin contained in the paint include vinyl acetate, vinyl propionate, butyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl versatate, vinyl laurate, Vinyl esters of carboxylic acids such as vinyl stearate, vinyl cyclohexyl carboxylate and vinyl benzoate, alkyl vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether, CTFE, vinyl fluoride (VF), And fluorine-containing monomers such as VdF and fluorinated vinyl ethers.

  Furthermore, the fluorine-containing resin contained in the paint may be a polymer composed of one or more monomers or a terpolymer. For example, Dyneon THV (trade name; manufactured by 3M Company), which is a terpolymer of VdF, TFE, and hexafluoropropylene. Such a multi-polymer is preferable because it can impart the properties of each monomer to the polymer. For example, the Dyneon THV (trade name) is preferable because it can be produced at a relatively low temperature, can be bonded to an elastomer or a hydrocarbon-based plastic, and is excellent in flexibility and optical transparency.

  In addition to the fluorine-containing resin, the paint may contain a crosslinking agent (curing agent), a catalyst (crosslinking accelerator), and a solvent, and if necessary, an inorganic compound such as a pigment and a filler. May be included.

  The solvent contained in the paint is not particularly limited as long as it does not impair the effect of the present invention. For example, methyl ethyl ketone (MEK), cyclohexanone, acetone, methyl isobutyl ketone (MIBK), toluene, xylene, methanol, isopropanol, ethanol , Heptane, ethyl acetate, isopropyl acetate, n-butyl acetate, or n-butyl alcohol can be preferably used. Among these, from the viewpoint of solubility of the components contained in the paint and low persistence in the coating film (low boiling point temperature), the solvent has at least one of xylene, cyclohexanone, and MEK. More preferably.

  The pigment and other additives that may be contained in the paint are not particularly limited as long as the effects of the present invention are not impaired. For example, titanium dioxide, carbon black, perylene pigment, pigment, dye, mica, polyamide powder, boron nitride, zinc oxide, aluminum oxide, silica, ultraviolet absorber, preservative, desiccant and the like can be mentioned. More specifically, Ti-Pure R105 (trade name; manufactured by EI du Pont de Nemours and Company), which is a rutile type titanium dioxide treated with silicon dioxide to impart durability, and the surface of dimethyl silicone A preferable example is CAB-O-SIL TS 720 (trade name; manufactured by Cabot), which is a hydrophobic silica in which hydroxyl groups on the silica surface are modified by treatment.

  The coating film is preferably cured with a crosslinking agent in order to improve weather resistance and scratch resistance. The crosslinking agent is not particularly limited as long as it does not impair the effects of the present invention, and examples thereof preferably include metal chelates, silanes, isocyanates, and melamines. When it is assumed that the solar cell module protective sheet is used outdoors for 30 years or more, aliphatic isocyanates are preferable as the cross-linking agent from the viewpoint of weather resistance.

The composition of the paint is not particularly limited as long as the effects of the present invention are not impaired. For example, the LUMIFLON (trade name), a pigment, a cross-linking agent, a solvent, and a catalyst are mixed as the composition of the paint based on the LUMIFLON. What is formed. The composition ratio is preferably 3 to 80% by weight, more preferably 25 to 50% by weight, and more preferably 5 to 60% by weight of the pigment when the entire coating is 100% by weight. 10 to 30% by mass is more preferable, and the organic solvent is preferably 20 to 80% by mass, and more preferably 30 to 70% by mass.
In the paint, MEK is preferred as the organic solvent, isocyanates are preferred as the crosslinking agent, and tin dibutyl dilaurate is preferred as a catalyst for promoting crosslinking with isocyanates of the LUMIFLON (trade name).

In the solar cell module protective sheets 10 and 20 of the present invention illustrated in FIG. 1, the coating material can be applied to the base material sheet 24 by a known method, for example, a bar coater (rod coater). What is necessary is just to apply | coat so that it may become a desired film thickness.
The film thickness of the fluorine-containing resin coat layer 22 formed by curing the paint is not particularly limited as long as the effects of the present invention are not impaired, and may be, for example, a film thickness of 5 μm or more. From the viewpoint of weather resistance and lightness, the film thickness of the fluorine-containing resin coat layer 22 is preferably 5 to 100 μm, more preferably 10 to 50 μm, further preferably 10 to 40 μm, particularly preferably 10 to 30 μm, Most preferred is 20 μm.

  The temperature in the drying process of the applied paint may be any temperature that does not impair the effects of the present invention, and is preferably in the range of 50 to 130 ° C. from the viewpoint of reducing the influence of heat on the base sheet 24. .

  The method for performing ion implantation on the surface of the fluorine-containing resin coat layer 22 in the solar cell module protective sheets 10 and 20 of the present invention is not particularly limited as long as it does not impair the effects of the present invention. Can be done by the method. For example, the method of ion-implanting with respect to the elongate solar cell module protection sheet 10 and 20 using the plasma ion implantation apparatus of Unexamined-Japanese-Patent No. 2006-070238 is mentioned as a preferable method.

  If the plasma ion implantation apparatus is used, the pressure at the time of ion implantation is set to 0.01 to 0.5 Pa, and plasma ions are conveyed while conveying the long solar cell module protection sheets 10 and 20 in a certain direction in a plasma atmosphere. A uniform ion implantation layer can be formed on the surface of the fluorine-containing resin coat layer 22 by an implantation method (PBII: Plasma-Based Ion Implantation). In this case, since the long solar cell module protective sheets 10 and 20 can be continuously ion-implanted while being conveyed in a fixed direction, the efficiency is high, and the solar cell module protective sheets 10 and 20 are suitable for mass production.

  The plasma ion implantation apparatus generates plasma only by an electric field generated by application of a high voltage pulse without using an external electric field generated by a high frequency power source such as a microwave. That is, in the plasma ion implantation apparatus, the long solar cell module protective sheets 10 and 20 are conveyed in a fixed direction, and at the same time, a negative high voltage is applied to the solar cell module protective sheets 10 and 20. As a result, plasma is generated, and ions in the plasma are injected into the surface portion of the fluorine-containing resin coat layer 22 of the protective sheet for solar cell module 10, 20, thereby forming an ion-implanted layer.

The configuration of the plasma ion implantation apparatus is shown in FIG.
In FIG. 4 (a), 41a is a long solar cell module protective sheet 10, 20, 51 is a chamber, 60 is a turbo molecular pump, 43 is a winding for delivering a solar cell module protective sheet 41a before ion implantation. A take-out roll 45 is a winding roll for winding the ion-implanted solar cell module protection sheet 41 into a roll shape, 42 is a high-voltage application rotation can, 50 is a gas inlet, and 47 is a high-voltage pulse power source. FIG. 4B is a perspective view of the high-voltage applying rotation can 42, and 55 is a high-voltage introduction terminal (feedthrough).

  In the continuous ion implantation apparatus shown in FIG. 4, the solar cell module protection sheet 41 a is conveyed in the chamber 51 from the unwinding roll 43 in the direction of arrow A in FIG. 4, and passes through the high-voltage applying rotation can 42. Then, it is wound around the winding roll 45. The method of winding the solar cell module protection sheet 41a, the method of transporting the solar cell module protection sheet 41a, and the like are not particularly limited. For example, by rotating the high voltage application rotation can 42 at a constant speed, The solar cell module protection sheet 41a is conveyed. The rotation of the high voltage application rotation can 42 is performed by rotating the central shaft 53 of the high voltage introduction terminal 55 by a motor.

  The high voltage introduction terminal 55 and the plurality of feed rolls 46 etc. with which the solar cell module protective sheet 41a contacts are made of an insulator, for example, the surface of alumina is covered with a resin such as polytetrafluoroethylene (PTFE). It is formed. The high-voltage applying rotation can 42 is made of a conductor, and is formed of, for example, stainless steel, SUS (Steel special Use Stainless), or the like.

  The conveyance speed of the protection sheet 41a for solar cell modules can be set suitably. The solar cell module protective sheet 41a is ion-implanted into the surface portion of the fluorine-containing resin coat layer of the solar cell module protective sheet until the solar cell module protective sheet 41a is transported from the unwinding roll 43 and wound up by the winding roll 45. There is no particular limitation as long as the time required for forming the ion-implanted layer is ensured. The winding speed (line speed) of the solar cell module protective sheet is usually 0.1 to 2 m / min, preferably 0.2 to 0.7 m / min, although it depends on the applied voltage and the diameter of the high voltage applied rotating can. min.

As a procedure of the ion implantation process, first, the chamber 51 is evacuated by the turbo molecular pump 60 to reduce the pressure. The degree of vacuum is usually 1.0 × 10 ^{−4 to} 3.0 × 10 ⁻³ Pa.

Next, an ion implantation gas (hereinafter also referred to as “ion implantation gas”) is introduced into the chamber 51 from the gas introduction port 50.
As described above, the ion implantation gas to be used is preferably He, Ar, Kr, N ₂ , or O ₂ .

  Next, the negative high voltage pulse 49 is applied to the high voltage application rotation can from the high voltage pulse power supply 47 through the high voltage introduction terminal 55 while the protection sheet 41a for the solar cell module is conveyed in the direction A in FIG. Apply.

  When a negative high voltage is applied to the high voltage application rotation can 42, plasma is generated along the solar cell module protection sheet 41a around the high voltage application rotation can 42, and ions in the plasma are induced, It is injected into the surface of the fluorine-containing resin coat layer of the protective sheet for solar cell module wound around the outer periphery of the high voltage application rotating can 42 (arrow B in FIG. 4A). When ions are implanted into the surface portion of the fluorine-containing resin coat layer, the surface portion is modified to form an ion implanted layer on the surface portion.

The pressure at the time of ion implantation (pressure at the time of plasma ion implantation) is preferably 0.01 to 0.5 Pa. The pulse width when generating plasma is preferably 1 to 10 μsec.
When the pressure during plasma ion implantation and the pulse width when generating plasma are within the above ranges, a uniform ion implantation layer can be formed on the surface portion of the fluorine-containing resin coating layer, and the effect of the present invention is achieved. Can be further enhanced.

  The applied voltage when applying a negative high voltage to the high-voltage applying rotation can 42 is preferably -1 kV to -50 kV, and particularly preferably -5 kV to -25 kv. When the applied voltage is within the above range, a sufficient ion implantation layer can be formed on the surface portion of the fluorine-containing resin coat layer, and the effects of the present invention can be further enhanced.

  As in the above example, when ions are implanted from the surface of the fluorine-containing resin coat layer 22 of the solar cell module protective sheet 10, 20, the surface portion of the fluorine-containing resin coat layer 22 is modified, An ion implantation layer is formed on the surface portion.

  An ion-implanted layer is formed on the surface portion of the fluorine-containing resin coat layer 22 after ion implantation, but only the extreme surface layer portion of the fluorine-containing resin coat layer 22 is modified and changed to an ion-implanted layer. Therefore, the characteristics of the fluorine-containing resin coat layer 22 such as weather resistance are not impaired.

The thickness of the ion implantation layer can be controlled by the winding speed (line speed) of the solar cell module protective sheet 41a, the ion implantation treatment time, the applied voltage, and the like.
The thickness of the ion-implanted layer of the fluorine-containing resin coat layer 22 of the solar cell module protective sheet 10 or 20 of the present invention is usually 0.1 to 100 nm.

The substrate sheet 24 in the solar cell module protective sheets 10 and 20 of the present invention may be a resin sheet or an aluminum sheet.
However, when the aluminum sheet is used as the base sheet 24, the solar cell module protective sheets 10 and 20 are not used as the front sheet 10 and are used as the back sheet 20 because they do not have optical transparency. It is done.

  As said resin sheet, what is generally used as a resin sheet in the protection sheet for solar cell modules can be used. For example, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polytetrafluoroethylene, polyamide (nylon 6, nylon 66), polyacrylonitrile, polyvinyl chloride, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate Examples thereof include sheets made of polymers such as (PEN), polyoxymethylene, polycarbonate, polyphenylene oxide, polyester urethane, poly m-phenylene isophthalamide, and poly p-phenylene terephthalamide. Especially, the sheet | seat which consists of polyesters, such as PET, PBT, PEN, from a viewpoint with favorable electrical insulation, heat resistance, chemical resistance, and dimensional stability is preferable, and PET sheet is mentioned as a more preferable thing.

  The thickness of the resin sheet may be adjusted based on the electrical insulation required by the solar cell system, and the thickness of the sheet is usually preferably in the range of 10 to 300 μm. More specifically, when the resin sheet is a PET sheet, the thickness of the PET sheet is preferably in the range of 10 to 300 μm from the viewpoint of lightness and electrical insulation, and is preferably 20 to 250 μm. The range is more preferable, the range of 30 to 200 μm is more preferable, the range of 40 to 150 μm is particularly preferable, and the range of 50 to 125 μm is most preferable.

The resin sheet may be subjected to a surface modification treatment for improving weather resistance, moisture resistance, and the like. For example, by depositing silica (SiO ₂ ) and / or alumina (Al ₂ O ₃ ) on the PET sheet, the weather resistance, moisture resistance, etc. of the protective sheet for solar cell module can be improved. In addition, the said vapor deposition process of the silica and / or alumina may be performed on both surfaces of the said resin sheet, and may be performed only on any one surface.

  When the base material sheet in the back sheet concerning the protection sheet for solar cell modules of this invention is an aluminum sheet, the weather resistance of the said back sheet and water vapor | steam barrier property can be improved more.

  The aluminum sheet is not particularly limited as long as it does not impair the effects of the present invention, but an aluminum-iron alloy containing iron in an amount of 0.7% by mass or more is preferable, and iron is 0.7 to More preferable is a sheet-like aluminum-iron alloy containing 5.0% by mass, and a sheet-like aluminum-iron alloy containing 1.0-2.0% by mass of iron. Preferably, an aluminum-iron alloy containing iron in a range of 1.2 to 1.7% by mass in the form of a sheet is most preferable.

  Examples of the aluminum-iron alloy containing iron in the most preferable range include those classified into alloy number 8021 defined in JIS H4160. As what made this aluminum-iron alloy into a sheet form, PACAL21 (brand name) by Nippon Foil Co., Ltd. can be used preferably, for example. Also, BESPA (trade name) manufactured by Sumi Light Aluminum Foil Co., Ltd. can be preferably used.

  By using the aluminum-iron alloy sheet containing iron within the above range, the water vapor barrier property and light weight of the back sheet can be improved as compared with the case of using a pure aluminum sheet. The reason for this is that an aluminum-iron alloy containing iron within the above range is generally superior in rolling processability compared to pure aluminum, and therefore, even when processed into a sheet having a thickness of 20 μm or less, the occurrence of pinholes is small. It is considered that the gas flow through the pinhole can be suppressed, and as a result, the water vapor barrier property of the back sheet using the aluminum-iron alloy sheet can be enhanced. In addition, since it is excellent in rolling processability, it can be processed into a sheet thinner than a pure aluminum sheet while maintaining the water vapor barrier property, and as a result, the back sheet using the aluminum-iron alloy sheet is lightweight. Can increase the sex.

  The aluminum-iron alloy sheet may contain an element other than iron as long as the effects of the present invention are not impaired. For example, magnesium, manganese, copper, silicon, zinc, titanium, etc. are mentioned. These elements may be inevitably contained in the production process of the aluminum-iron alloy, but generally it is considered that the effect of the present invention is not impaired if the content is very small. Here, as said trace amount content, the case where each element is 0.5 mass% or less, respectively, More preferably, it is the case where it is 0.3 mass% or less.

  The thickness of the aluminum-iron alloy sheet is not particularly limited as long as the effects of the present invention are not impaired. From the viewpoint of low pinhole occurrence frequency (high water vapor barrier property) and light weight, it is preferable. Is 30 μm or less, more preferably 20 μm or less, and most preferably in the range of 5 to 10 μm.

  As illustrated in FIG. 2, the base sheet 24 in the solar cell module protective sheet 10, 20 of the present invention has a support sheet on the surface (back surface) opposite to the surface on which the fluorine-containing resin coat layer 22 is laminated. 26 are preferably laminated. By laminating the support sheet 26, the properties of the material of the support sheet 26 can be added to the solar cell module protection sheets 10 and 20.

  The method for laminating the base sheet 24 and the support sheet 26 is not particularly limited as long as the effects of the present invention are not impaired, and further between the base sheet 24 and the support sheet 26. An adhesive layer 28 is provided, and the base sheet 24 and the support sheet 26 can be laminated via the adhesive layer 28.

  The adhesive layer 28 preferably includes an adhesive having adhesiveness to the base sheet 24 and the support sheet 26.

  The adhesive is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include acrylic adhesives, urethane adhesives, epoxy adhesives, ester adhesives, and the like. In order to improve the adhesiveness, the surface of the base sheet 24 and the support sheet 26 on the side of the adhesive layer 28 may be subjected to corona treatment and / or chemical treatment.

The support sheet 26 in the solar cell module protective sheets 10 and 20 of the present invention can be appropriately selected depending on the type of the base sheet 24 to be laminated.
For example, when the base sheet 24 is the above-described resin sheet, the support sheet 26 is preferably a thermal adhesive sheet. By using the heat-adhesive sheet as the support sheet 26, the solar cell module protection sheets 10 and 20 can be easily thermally bonded to the sealing material 30 constituting the solar cell module.

Moreover, when the base material sheet 24 is an aluminum sheet, it is preferable that the said support sheet 26 is the above-mentioned resin sheet or a heat bondable sheet.
By using the resin sheet as the support sheet 26, electrical insulation and the like can be imparted to the solar cell module protection sheet (back sheet 20). In this case, it is preferable to laminate a thermal adhesive sheet on the support sheet 26 made of the resin sheet on the surface (back surface) opposite to the surface on which the substrate sheet 24 is laminated. By laminating the thermal adhesive sheet on the support sheet 26 made of the resin sheet, the solar cell module protective sheet (back sheet 20) is easily thermally bonded to the sealing material 30 constituting the solar cell module. can do.
On the other hand, by using the thermal adhesive sheet as the support sheet 26, the solar cell module protective sheet (back sheet 20) can be easily thermally bonded to the sealing material 30 constituting the solar cell module. it can.

  The thermal adhesive sheet is not particularly limited as long as it is a resin sheet having thermal adhesiveness without impairing the effects of the present invention. Here, thermal adhesiveness is a property that develops adhesiveness by heat treatment. As temperature in this heat processing, it is the range of 50-200 degreeC normally.

  As the thermal adhesive sheet, for example, a resin sheet made of a polymer mainly composed of ethylene vinyl acetate (EVA) or polyolefin is preferable, and a resin sheet made of a polymer mainly composed of EVA is more preferable. Generally, the sealing material 30 is often a sealing resin made of EVA, and in that case, the thermal adhesive sheet is a resin sheet made of a polymer mainly composed of EVA. The compatibility and adhesion between the thermal adhesive sheet 30 and the thermal adhesive sheet can be improved.

  The thickness of the heat-adhesive sheet may be appropriately adjusted depending on the kind of the heat-adhesive sheet, and it is usually preferable that the thickness of the sheet is in the range of 1 to 200 μm. More specifically, when the thermal adhesive sheet is a sheet made of EVA, the thickness of the EVA sheet is in the range of 10 to 200 μm from the viewpoints of light weight and electrical insulation. Preferably, it is in the range of 50 to 150 μm, more preferably in the range of 80 to 120 μm.

  The method for laminating the thermal adhesive sheet on the resin sheet is not particularly limited as long as it does not impair the effects of the present invention, and the resin sheet is obtained by dissolving a thermal adhesive resin in a solvent or dispersing in water. It may be applied to form a coating film, or an additional adhesive layer may be provided between the resin sheet and the thermoadhesive resin sheet, and the thermal adhesiveness may be provided via the adhesive layer. A sheet and the resin sheet may be laminated. The adhesive layer preferably contains an adhesive having adhesiveness to the thermal adhesive sheet and the resin sheet. Examples of the adhesive include acrylic adhesives, urethane adhesives, epoxy adhesives, and ester adhesives. Moreover, in order to improve the adhesiveness, the surface on the adhesive layer side of the thermal adhesive sheet and the resin sheet can be subjected to corona treatment and / or chemical treatment.

As shown in the schematic diagram of FIG. 3, the solar cell module protective sheets 10, 20 according to the present invention are laminated on a sealing surface made of a sealing material 30 that encloses solar cells 40, thereby the solar cell. The solar battery cell 40 and the sealing material 30 in the module can be protected from wind and rain, moisture, dust, mechanical shock, and the like, and the inside of the solar battery module can be completely shielded from the outside air and kept sealed.
When laminating the solar cell module protective sheet of the present invention on the sealing surface, the non-coated surface of the fluorine-containing resin in the solar cell module protective sheet is laminated on the sealing surface. As the lamination method, a known method can be applied.

  The solar cell module protective sheet of the present invention is preferably used as both the front sheet 10 and the back sheet 20, but is more preferably used as the back sheet 20 from the viewpoint of light transmission.

  EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited to a following example.

[Preparation Example 1: Paint containing fluorine-containing resin: coating agent]
120 parts by mass of MEK, 18.2 parts by mass of hydrophobic silica {trade name: CAB-O-CIL TS-720 (manufactured by Cabot Corporation)}, titanium oxide {trade name: Ti-Pure R105 (EI du Pont de Nemours and Company))} in an amount of 100 parts by mass was added to a pigment disperser {device name: T.M. K. Homodispers (manufactured by Primix Co., Ltd.)} to prepare a pigment dispersion.
Subsequently, 100 parts by mass of a CTFE copolymer {trade name: LUMIFLON LF200 (solid content 60%) (manufactured by Asahi Glass Co., Ltd.)} is added to 87 parts by mass of the pigment dispersion, and an isocyanate-based crosslinking agent (curing agent) { 10.7 parts by mass of product name: Sumijour N3300 (manufactured by Sumika Bayer Urethane Co., Ltd.)}, 0.004 part by mass of crosslinking accelerator {product name: BXX3778-10 (manufactured by Toyo Ink Manufacturing Co., Ltd.)}, MEK Was mixed in an amount of 110 parts by mass to prepare a coating agent.

[Preparation Example 2: Fluorine-containing resin coat on PET sheet]
On one side (one side) of a PET sheet {product name: Mylar A (manufactured by DuPont Teijin Films)} with a thickness of 125 μm, apply the coating agent to a bar coater so that the coating thickness after drying is 13 μm. And then dried at 120 ° C. for 2 minutes to prepare a protective sheet for a solar cell module.

[Examples 1 to 5]
The ion species shown in Table 1 were ion-implanted into the fluorine-containing resin coat layer of the protective sheet for a solar cell module prepared in Preparation Example 2 using the plasma ion implantation apparatus shown in FIG.
As conditions for the plasma ion implantation, the pressure in the chamber is 0.2 Pa, the type of gas for ion implantation is shown in Table 1, and the voltage when applying a negative high voltage to the high voltage application rotary can, The pulse width and pulse repetition frequency were set to -10 kV, 5 μsec, and 1000 Hz, respectively. Moreover, the ion implantation process for 5 minutes was performed in the unit area of the said fluorine-containing resin coat layer by making the conveyance speed of the protection sheet for solar cell modules into 0.2 m / min.

The water vapor permeability, the wet tension, the contact angle, and the label adhesive force were measured on the protective sheet for a solar cell module after the ion implantation treatment obtained in Examples 1 to 5.
Moreover, the same measurement was performed by making the protective sheet for solar cell modules which has not been ion-implanted into Comparative Example 1.
These results are also shown in Table 1.

<Measurement of water vapor transmission rate>
The amount of water vapor (water vapor permeability) permeating from the fluorine-containing resin coat layer side of the protective sheets for solar cell modules obtained in Examples 1 to 5 and Comparative Example 1 was measured.
Specifically, according to the standard of ISO 15106-1: 2003, a moisture permeation meter {trade name: L80-5000 (PBI- Measured by using Dansensor).
The results are also shown in Table 1.

<Measurement of wetting tension>
The wetting tension of the surface of the fluorine-containing resin coat layer of the protective sheet for a solar cell module obtained in Examples 1 to 5 and Comparative Example 1 was measured.
Specifically, according to the standard of ISO8296: 2003, it measured using the liquid mixture for wet tension tests {made by Wako Pure Chemical Industries Ltd.}.
The results are also shown in Table 1.
Note that the wet tension test mixed solution is more suitable when the wet tension is measured in the range of 31.0 to 54.0 mN / m, and gives a measurement value outside this range (Example 5, For Comparative Example 1), it was shown in Table 1 that the above range was exceeded instead of showing the measured value.

<Measurement of contact angle>
The contact angle of the surface of the fluorine-containing resin coat layer of the protective sheet for a solar cell module obtained in Examples 1 to 5 and Comparative Example 1 was measured.
Specifically, according to the standard of JIS R3257: 1999, it measured using the contact angle measuring device {Brand name: DSA100 (made by Kruess GmbH)}.
The results are also shown in Table 1.

<Measurement of label adhesive strength>
A label {product name: PETWH50 (A) PA-T1 () having an adhesive layer made of an adhesive on the surface of the fluorine-containing resin coat layer of the protective sheet for a solar cell module obtained in Examples 1 to 5 and Comparative Example 1. (Lintec Co., Ltd.)} was affixed with a width of 25 mm and left for 30 minutes or 24 hours, and then the adhesive strength of the label was measured as follows.
Specifically, it was measured according to the standard of JIS Z0237: 2000 180 degree peeling adhesive strength.
The results are also shown in Table 1.

From the above results, it is clear that the solar cell module protective sheets of Examples 1 to 5 according to the present invention are superior in water vapor barrier property and wettability as compared with the solar cell module protective sheet of Comparative Example 1. .
Furthermore, since the surface of the fluorine-containing resin coat layer of the protective sheet for solar cell module of Examples 1 to 5 according to the present invention is excellent in wettability, the label adhesive strength to the surface is greater (the label is more peeled off from the surface). It is also clear.
Moreover, it is possible to print and print on the fluorine-containing resin coat layer of the said protection sheet for solar cell modules.

10 ... Front sheet (light transmissive surface protective sheet) 20 ... Back sheet (back surface protective sheet)
DESCRIPTION OF SYMBOLS 22 ... Fluorine-containing resin coat layer 24 ... Base material sheet 26 ... Support sheet 28 ... Adhesive layer 30 ... Sealing material 40 ... Solar cell 41 ... Solar cell module protection sheet 42 ... High voltage application rotation can 43 ... Unwinding roll 45 ... take-up roll 46 ... delivery roll 47 ... high voltage pulse power supply 49 ... high voltage pulse 50 ... gas inlet 51 ... chamber 53 ... central axis 55 ... high voltage introduction terminal 60 ... turbo molecular pump

Claims (3)

  A solar cell module protection comprising a base sheet and a fluorine-containing resin coat layer laminated on at least one surface of the base sheet, wherein the fluorine-containing resin coat layer is ion-implanted Sheet. The protective sheet for a solar cell module according to claim 1, wherein at least one selected from He, Ar, Kr, N ₂ and O ₂ is ion-implanted in the fluorine-containing resin coat layer.   The said base material sheet is a resin sheet, The protective sheet for solar cell modules of Claim 1 or 2 characterized by the above-mentioned.

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