JP2011159913A - Back protective sheet for solar cell module, and the solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a back protective sheet for a solar cell module more superior in wet heat resistance, more reduced in degradation under a wet heat environment, and more superior in durability than a conventional product. <P>SOLUTION: In the back protective sheet for the solar cell module, thermoplastic resin layers are laminated on one or both sides of a base material sheet made of polyphenylene ether. The solar cell module is formed by bonding the back protective sheet for solar cell module to it. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a back surface protective sheet for a solar cell module and a solar cell module including the same.

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. The solar cell module is required to have high power generation efficiency and durability that can withstand long-term use even when used outdoors.
The main components of the solar cell module are photovoltaic cells that are photovoltaic elements, sealing materials that are electrical insulators that prevent short circuits in the electric circuit, and protective sheets (surface protective sheet and back protective sheet) that protect them. Become. Generally, in order to increase the durability of the solar cell module, it is considered important to improve the performance of the protective sheet.

When a solar cell module is used for a long period of time, in order to prevent electric leakage and corrosion of an electric circuit in the solar cell module, the solar cell module protective sheet is required to have high moist heat resistance and gas barrier properties.
Conventionally, polyethylene terephthalate (hereinafter abbreviated as PET) or hydrolysis-resistant PET has been generally used as a substrate for a solar cell module protective sheet (see, for example, Patent Document 1).
Patent Document 1 discloses a three-layer laminate of a hydrolysis-resistant resin film, a metal oxide-coated resin film, and a white resin film, or a hydrolysis-resistant resin film and a white resin film coated with a metal oxide. Or a two-layer laminate of a hydrolysis-resistant resin film and a white resin film coated with a metal oxide. ) Is disclosed. A PET film is used as the hydrolysis-resistant resin film.
Further, Patent Document 2 discloses a solar cell module back sheet (back surface protective sheet) in which a cured coating film of a curable functional group-containing fluoropolymer paint is formed on a base sheet made of a resin such as PET. Yes.

Japanese Patent Laid-Open No. 2002-100788 International Publication No. 2007/010706 Pamphlet

However, the conventional back surface protection sheet for solar cell modules based on PET has insufficient moisture and heat resistance to protect solar cell modules installed outdoors for a long period of time, and further performance improvement is required. ing.
In addition, as in Patent Document 2, by forming a cured coating film of a fluoropolymer paint on the surface of the PET substrate, an effect of improving the weather resistance of the PET substrate can be obtained. When the surface layer of the base material was hydrolyzed, the cured coating film of the fluoropolymer paint was easily peeled off.
In addition, as a resin material excellent in heat-and-moisture resistance, polyphenylene ether is mentioned, for example. However, since the base sheet made of polyphenylene ether has a weak tear strength, there is a problem that it is difficult to apply as a base sheet for a back surface protection sheet for solar cell modules.

  This invention is made | formed in view of the said situation, and it aims at provision of the back surface protection sheet for solar cell modules which was excellent in wet heat resistance compared with the conventional product, there was little deterioration in a humid heat environment, and was excellent in durability.

  In order to achieve the above object, the present invention provides a back surface protection sheet for a solar cell module, wherein a thermoplastic resin layer is laminated on one or both sides of a base sheet made of polyphenylene ether. .

  In this invention, it is preferable that the thermoplastic resin layer is laminated | stacked on the one surface side of the said base material sheet, and the fluororesin layer is laminated | stacked on the other surface side of the said base material sheet.

  In this invention, it is preferable that the gas barrier film layer is laminated | stacked between the said base material sheet and the said thermoplastic resin layer.

  Moreover, this invention provides the solar cell module by which the said back surface protection sheet for solar cell modules is adhere | attached.

Since the back surface protection sheet for a solar cell module of the present invention uses a base sheet made of polyphenylene ether, it can improve the heat and moisture resistance compared to a conventional PET base material. A solar cell module having excellent durability can be provided by bonding to the module body.
Moreover, since the back surface protection sheet for solar cell modules of the present invention uses a base sheet made of polyphenylene ether, it is excellent in heat and moisture resistance, and the deterioration of the base sheet is reduced even in a high humidity and heat environment. Even if it has a structure in which a cured coating film of a fluoropolymer paint is laminated on a base sheet, the adhesion of the coating film can be improved, and the coating film is difficult to peel off.
Moreover, since the back surface protection sheet for solar cell modules of the present invention has a structure in which a thermoplastic resin layer is laminated on one or both surfaces of a base sheet made of polyphenylene ether, the tear strength can be improved. .

  Since the solar cell module of the present invention is obtained by adhering the back surface protection sheet for solar cell modules according to the present invention to the solar cell module body, it is higher than the case of adhering the back surface protection sheet using a conventional PET base material. It is possible to provide a solar cell module that is less deteriorated in a humid heat environment and has excellent durability.

It is the schematic diagram which showed the structure of the solar cell module of this invention. It is the schematic diagram which showed the cross section of 1st Embodiment of the back surface protection sheet for solar cell modules of this invention. It is the schematic diagram which showed the cross section of 2nd Embodiment of the back surface protection sheet for solar cell modules of this invention. It is the schematic diagram which showed the cross section of 3rd Embodiment of the back surface protection sheet for solar cell modules of this invention.

FIG. 1 is a schematic diagram showing a configuration of a solar cell module using the back surface protection sheet for a solar cell module of the present invention.
As illustrated in FIG. 1, the configuration of the solar cell module 50 using the back surface protection sheet of the present invention includes a surface protection sheet 10, a back surface protection sheet 20, a sealing material 30, and solar cells 40. 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, the back surface protection sheet 20 is required to have sufficient weather resistance.

[First Embodiment]
FIG. 2 is a schematic view showing a cross-section of the first embodiment of the back surface protection sheet for solar cell modules of the present invention (hereinafter abbreviated as back surface protection sheet).
The back surface protective sheet 60A of the present embodiment has a configuration in which a thermoplastic resin layer 62 is laminated on one surface of a base sheet 61 made of polyphenylene ether (hereinafter abbreviated as PPE) with an interlayer adhesive layer 63 interposed therebetween. It has become.

  PPE (also referred to as polyphenylene oxide (PPO) or the like) that is the material of the base sheet 61 is 2,6-xylenol (2,6-dimethyl) synthesized by an alkylation reaction from phenol and methanol. Phenol) is a basic raw material, which is a resin synthesized by oxidative polymerization (oxidative coupling method), and is superior in moisture and heat resistance compared to PET, which is a conventional base sheet material. The PPE used as the material of the base sheet 61 may be PPE alone or a polymer alloy of PPE and another resin material. In particular, a polymer alloy of PPE and polystyrene is preferable because the tear strength can be improved.

  What is necessary is just to select as thickness of the said base material sheet 61 based on the electrical insulation which a solar cell system requires, lightweight property, etc., for example, it is preferable that it is the range of thickness 10-300 micrometers, 30-200 micrometers. More preferably, it is the range of 50-150 micrometers. Examples of such commercially available PPE base sheet 61 include Noryl (trade name) manufactured by SABIC Innovative Plastics, Iupiace (trade name) manufactured by Mitsubishi Engineering Plastics, and Zylon manufactured by Asahi Kasei Chemicals. (Product name).

  The material of the thermoplastic resin layer 62 is not particularly limited and can be appropriately selected from various resin materials. The protective sheet 60A of the present embodiment is intended to adhere the thermoplastic resin layer 62 to the sealing material 30 of the solar cell module body, and uses a resin having good adhesiveness with the sealing material 30. It is preferable. Examples of such a resin include an ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA), an ethylene-acrylate copolymer, an ethylene-α-olefin copolymer, polyethylene, and polyvinyl butyral. . Among these resins, ethylene-vinyl acetate copolymer and polyvinyl butyral are preferable from the viewpoint of improving tear strength, and ethylene-vinyl acetate copolymer is particularly preferable. Moreover, in order to improve electric power generation efficiency, it is preferable that it is white, and as a white thermoplastic resin, the white pigment and the polyethylene terephthalate containing a bubble are mentioned.

  The thickness of the thermoplastic resin layer 62 is not particularly limited, and may be selected based on adhesion stability to the sealing material 30, lightness, and the like. For example, the thickness is preferably in the range of 10 to 300 μm. The range of 30 to 200 μm is more preferable, and the range of 50 to 150 μm is more preferable.

Various additives such as pigments, ultraviolet absorbers, ultraviolet stabilizers, flame retardants, plasticizers, antistatic agents, lubricants, antiblocking agents, and the like are added to the base sheet 61 and the thermoplastic resin layer 62 as necessary. May be included.
The pigment is not particularly limited as long as the effect of the present invention is not impaired. Examples thereof include titanium dioxide, carbon black, perylene, mica, boron nitride, zinc oxide, aluminum oxide, and silica.
Examples of the ultraviolet absorber include benzophenone series, benzotriazole series, oxalic acid anilide series, cyanoacrylate series and triazine series.

  The adhesive used as the material for the laminating adhesive layer 63 is not particularly limited as long as the base sheet 61 and the thermoplastic resin layer 62 can be firmly bonded. For example, an acrylic adhesive, a urethane adhesive, an epoxy System adhesives and the like. These adhesives may be used individually by 1 type, and may be used in combination of 2 or more type.

Since the protective sheet 60A of the present embodiment has a configuration in which a thermoplastic resin layer 62 is laminated on one surface of a PPE base material sheet 61 via an interlayer adhesive layer 63, a conventional PET base material is used. As compared with the above, it is possible to improve the heat and moisture resistance, and by using this by adhering to the solar cell module body, it is possible to provide the solar cell module 50 having excellent durability.
Further, the protective sheet 60A of the present embodiment uses the PPE base material sheet 61, so that the interlayer adhesive layer 63 is less deteriorated in a humid heat environment than a conventional laminated sheet using a PET base material. Thus, even when used for a long period of time, the thermoplastic resin layer 62 is hardly peeled off from the base sheet 61, and the solar cell module 50 having excellent durability can be provided.
Furthermore, tearing strength can be improved by setting it as the structure which laminated | stacked the thermoplastic resin layer 62 on the one surface of the base material sheet 61 made from PPE via the interlayer adhesive layer 63. FIG.

[Second Embodiment]
Drawing 3 is a mimetic diagram showing the section of the 2nd embodiment of the back protection sheet of the present invention.
In the back surface protective sheet 60 </ b> B of the present embodiment, a thermoplastic resin layer 62 is laminated on one surface of the base material sheet 61 via an interlayer adhesive layer 63, and a fluororesin coat layer is further formed on the other surface of the base material sheet 61. 64 is laminated. The details of the base sheet 61, the thermoplastic resin layer 62, and the interlayer adhesive layer 63 can be the same as those of the protective sheet 60A of the first embodiment.

  The fluororesin coat layer 64 is for imparting weather resistance to the back surface protection sheet 60B. In the present embodiment, a coating material containing a fluorine-containing polymer is applied to reduce the weight of the protection sheet. It is formed by the coating film which hardened it. The paint having a fluorine-containing polymer is not particularly limited as long as it can be applied by being dissolved in a solvent or dispersed in water.

  The fluorine-containing polymer that may be contained in the paint is not particularly limited as long as it does not impair the effects of the present invention and is a fluorine-containing polymer, but dissolves in the solvent (organic solvent or water) of the paint, Those that can be crosslinked are preferred. As a preferable example of the fluorine-containing polymer, chlorotrifluoroethylene (CTFE) such as LUMIFLON (trade name) manufactured by Asahi Glass Co., Ltd., CEFLARCOAT (trade name) manufactured by Central Glass Co., Ltd. Polymers mainly composed of tetrafluoroethylene (TFE) such as ZEFFLE (trade name) manufactured by Daikin Industries, Ltd., Zonyl (trade name) manufactured by DuPont, Daikin Industries Examples thereof include polymers having a fluoroalkyl group such as UNIDYNE (trade name), and polymers having a fluoroalkyl unit as a main component. Among these, from the viewpoint 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. Among them, LUMIFLON (trade name) and ZEFFLE (trade name) are preferable. Most preferred.

The LUMIFLON (trade name) is an amorphous polymer containing CTFE and several kinds of specific alkyl vinyl ethers 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, crosslinking reactivity, substrate adhesion, pigment dispersibility, hardness, and flexibility.
The ZEFFLE (trade name) is a copolymer of TFE and an organic solvent-soluble hydrocarbon monomer (which may contain oxygen), and in particular, the copolymer has a highly reactive hydroxyl group. Is preferable because it is excellent in solvent solubility, cross-linking reactivity, substrate adhesion, and pigment dispersibility.

  Examples of the fluorine-containing polymer that may be contained in the paint include fluoroolefin polymers having a curable functional group. Specific examples thereof include TFE, isobutylene, vinylidene fluoride (VdF), hydroxy Preferred are a copolymer composed of butyl vinyl ether and other monomers, and a copolymer composed of TFE, VdF, hydroxybutyl vinyl ether and other monomers.

  Examples of the copolymerizable monomer in the fluorine-containing polymer that may be contained in the paint include, for example, vinyl acetate, vinyl propionate, butyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl versatate, Examples include vinyl esters of carboxylic acids such as vinyl laurate, vinyl stearate, vinyl cyclohexylcarboxylate, and vinyl benzoate, and alkyl vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether.

  In addition to the fluorine-containing polymer, the coating material may contain a crosslinking agent, a catalyst, and a solvent, and may further contain an inorganic compound such as a pigment if necessary.

  The solvent contained in the paint is not particularly limited as long as the effect of the present invention is not impaired. 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. Especially, it is more preferable that the said solvent has any 1 or more types among MEK or MIBK from a soluble viewpoint of the component contained in a coating material.

  The pigment that may be contained in the paint is not particularly limited as long as the effect of the present invention is not impaired. Examples thereof include titanium dioxide, carbon black, perylene, mica, boron nitride, zinc oxide, aluminum oxide, and silica. More specifically, Ti-PURE R105 (trade name) manufactured by DuPont, which is a rutile-type titanium dioxide that has been coated and surface-treated to impart durability, and hydroxyl groups on the silica surface by surface treatment of dimethyl silicone. CAB-O-SIL TS (trade name) manufactured by Cabot, which is a modified hydrophobic silica, can be exemplified as a preferable one.

  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. Assuming that the protective sheet is used outdoors for 30 years or more, aliphatic isocyanates are preferable as the crosslinking agent from the viewpoint of weather resistance.

The composition of the coating is not particularly limited as long as the effects of the present invention are not impaired. For example, as the composition of the coating based on the LUMIFLON (trade name), the LUMIFLON (trade name), a pigment, a crosslinking agent, a solvent And those obtained by mixing a catalyst. The composition ratio is preferably 3 to 80% by mass, more preferably 10 to 40% by mass, and more preferably 5 to 60% by mass of the pigment when the entire coating is 100% by mass. The organic solvent is preferably 20 to 80% by mass, more preferably 30 to 70% by mass.
Examples of the organic solvent include a mixed solvent of MEK, xylene, and cyclohexanone. Examples of the catalyst include tin dibutyl dilaurate and tin dioctyl dilaurate, which are used to promote crosslinking between LUMIFLON (trade name) and isocyanate in an organic solvent.

As a method of applying the paint to the other surface of the base sheet 61, a known method can be used. For example, the coating may be applied with a rod coater so as to have a desired film thickness.
The film thickness of the fluororesin coat layer 64 formed by curing the paint is not particularly limited, 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 fluororesin coat layer 64 is preferably 5 to 50 μm, more preferably 8 to 40 μm, and particularly preferably 10 to 30 μm.
The temperature in the drying process of the applied paint may be a temperature that does not impair the effects of the present invention, and is in the range of about 50 to 130 ° C. from the viewpoint of promoting the crosslinking and reducing the influence on the base sheet 61. It is preferable.

  As with the protective sheet 60A of the first embodiment, the protective sheet 60B of the present embodiment can improve moisture and heat resistance as compared to the conventional sheet using a PET base material, and is bonded to the solar cell module body. As a result, the solar cell module 50 having excellent durability can be provided, and the fluororesin coat layer 64 is laminated on the other surface of the base sheet 61. The weather resistance of the back surface protective sheet 60B can be improved.

[Third Embodiment]
FIG. 4 is a schematic view showing a cross section of a third embodiment of the back surface protective sheet of the present invention.
In the back surface protective sheet 60C of the present embodiment, an interlayer adhesive layer 63, a silica-deposited PET layer 65, an interlayer adhesive layer 63, and a thermoplastic resin layer 62 are sequentially laminated on one surface of a PPE base material sheet 61. It is configured. The details of the base sheet 61, the thermoplastic resin layer 62, and the interlayer adhesive layer 63 can be the same as in the case of the first embodiment.

The silica-deposited PET layer 65 is preferably a film obtained by depositing silica (SiO ₂ ) on the PET film surface. This silica-deposited PET layer 65 is excellent in gas barrier properties, in particular, water vapor barrier properties, and by laminating the silica-deposited PET layer 65, the water vapor barrier properties of the back protective sheet 60C can be improved. The thickness of the silica deposited PET layer 65 is not particularly limited, but the PET film thickness is preferably in the range of 5 to 50 μm, more preferably in the range of 6 to 40 μm, and the silica layer thickness is preferably in the range of 1 to 500 nm. A range of ˜100 nm is more preferable. From the viewpoint of preventing the hydrolysis of PET, the PET side is preferably provided on the sealing material side. Thereby, the water vapor | steam which reaches PET can be reduced and hydrolysis of PET can be suppressed.

  As with the protective sheet 60A of the first embodiment, the protective sheet 60C of the present embodiment can improve the heat and moisture resistance and gas barrier properties compared to those using a conventional PET base material. By adhering to the main body, effects such as providing a solar cell module 50 with excellent durability can be obtained. Further, by laminating the silica-deposited PET layer 65, the water vapor barrier of the protective sheet 60C is obtained. Can increase the sex.

[Solar cell module]
As shown in FIG. 1, the solar cell module of the present invention is obtained by adhering and laminating any one of the above-described back surface protective sheets 60 </ b> A to 60 </ b> C to the back surface side of the sealing material 30 of the solar cell module 50.
The type and structure of the solar cell module 50 are not particularly limited, and are a-Si (amorphous silicon) solar cells, c-Si (crystalline silicon) solar cells, μc-Si (microcrystalline silicon) solar cells, GaAs (gallium arsenide). ) And the like, and a dye-sensitized solar cell.

[Example 1]
As the PPE base material sheet, Noryl EFR735 (trade name) manufactured by SABIC Innovative Plastics Co., Ltd. having a thickness of 152 μm was used.
An interlayer adhesive (main agent: Takelac A-515 (trade name) manufactured by Mitsui Chemicals, Inc.) and a hardener: Takenate A-3 (trade name) manufactured by Mitsui Chemicals, on one surface of the PPE substrate sheet, Base agent: Curing agent = 7: 1 (solid content ratio)) was applied and dried at 80 ° C. for 1 minute to form an interlayer adhesive layer having a thickness of 10 μm.
Next, an EVA film with a thickness of 100 μm was laminated on this adhesive layer (the film was made of ethylene: vinyl acetate = 91: 9 with a thickness of 100 μm by a T-die extrusion film forming machine) and laminated. Thus, a back surface protection sheet having the configuration shown in FIG. 2 was produced.
The laminating conditions were as follows: the laminating temperature was room temperature, and the aging conditions were 23 ° C. ± 2 ° C. for 7 days.

[Example 2]
A back protective sheet was produced in the same manner as in Example 1 except that a white PET film (Lumirror E20 (trade name) manufactured by Toray Industries, Inc., thickness 75 μm) was used instead of the EVA film.

[Example 3]
After forming the fluororesin coat layer on one surface of the PPE base material sheet, the EVA film is laminated on the other surface through the interlayer adhesive layer in the same manner as in Example 1, thereby showing in FIG. A backside protective sheet having a configuration was prepared.
Details of the formation of the fluororesin coat layer were as follows.

(Preparation of coating agent)
120 parts by mass of MEK, 18.2 parts by mass of hydrophobic silica (CAB-O-SIL TS-720 (trade name) manufactured by Cabot), and 100 of titanium oxide (Ti-Pure R105 (trade name) manufactured by DuPont) What is blended in the amount of parts by mass is a pigment disperser {device name: T.M. K. Homodispers (Primics Co., Ltd.)} was used to make a pigment dispersion.
Next, in 87 parts by mass of the pigment dispersion, 100 parts by mass of a CTFE copolymer (LUMIFLON LF200 (trade name, solid content 60%) manufactured by Asahi Glass Co., Ltd.), an isocyanate-based crosslinking agent (curing agent) (Bayer Material Science) 10.7 parts by mass of DESMODUR N3300 (trade name) manufactured by the company, 0.004 parts by mass of crosslinking accelerator (BXX3778-10 (trade name) manufactured by Toyo Ink Manufacturing Co., Ltd.) and 110 parts by mass of MEK A coating agent was prepared.

(Fluoro resin coating on base sheet)
The coating agent is applied to one surface of the PPE substrate sheet with a bar coater so that the coating thickness after drying is 13 μm, and dried at 120 ° C. for 2 minutes to obtain a fluororesin coating layer Formed.

[Example 4]
A back protective sheet was produced in the same manner as in Example 3 except that the white PET film was used instead of the EVA film.

[Example 5]
Silica (SiO ₂ ) was vapor-deposited on one surface of a PET film (Mylar A (trade name) manufactured by Teijin DuPont Films, Inc., thickness 12 μm) to a thickness of 50 nm to prepare a silica-deposited PET film.
The silica-deposited PET film is adhered to one surface of the same PPE substrate sheet as in Example 1 using the interlayer adhesive described in Example 1, and further, the interlayer-deposited adhesive is used for the silica-deposited PET film. The same EVA film as that used in Example 1 was adhered to prepare a back surface protection sheet having the configuration shown in FIG.
The interlayer adhesive and the lamination conditions were the same as in Example 1.

[Example 6]
A back protective sheet was produced in the same manner as in Example 5 except that the white PET was used instead of the EVA film.

[Comparative Example 1]
A backside protective sheet was prepared in the same manner as in Example 1 except that a PET substrate sheet (Merinex 238 (trade name) manufactured by Teijin DuPont Films, Inc., thickness 125 μm) was used instead of the PPE substrate sheet. did.

[Comparative Example 2]
A backside protective sheet was prepared in the same manner as in Example 3 except that instead of the PPE base sheet, a PET base sheet (Melinex 238 (trade name) manufactured by Teijin DuPont Films Ltd., thickness 125 μm) was used. did.

  About the back surface protection sheets prepared in Examples 1 to 6 and Comparative Examples 1 and 2, for each item of <Tear Strength>, <Measurement of Breaking Strength Retention> and <Adhesiveness of Fluororesin Layer> Measurements were made under the same measurement conditions and compared.

<Tear strength>
It was measured at a test speed of 200 mm / min according to JIS K7128-1: 1998 “Plastic—Tear Strength Test Method for Films and Sheets—Part 1: Trouser Tear Method”.
The processing direction of the back surface protection sheet was displayed as MD, and the direction perpendicular to MD was displayed as CD. The results are shown in Table 1.

<Measurement of breaking strength retention>
The break strength was measured according to JIS K7127: 1999.
The measurement conditions were as follows.
Test environment: 23 ° C, 50% RH
・ Sample size: width 15mm x length 150mm
・ Tensile speed: 200 mm / min
Test method: The upper and lower ends of the back surface protection sheet were each fixed to a universal tensile tester so that the chuck interval was 100 mm. The sample was pulled at a speed of 200 mm / min, and the load when the back protective sheet was broken was measured.
Each protective sheet measures the breaking load before <wet and heat resistance test> and <weather resistance test> to be described later, and the breaking load after performing a test for a certain period of time, and the ratio to the breaking load before the test ( Percent) and calculated as the breaking strength retention.
Table 2 shows the measurement results of the retention strength at break when the <moisture and heat resistance test> is performed. Table 3 shows the measurement results of the breaking strength retention when the <weather resistance test> is performed.

<Adhesiveness of fluororesin layer>
About the back surface protection sheet produced in Example 3 and Comparative Example 2, before performing <moisture and heat resistance test> to be described later and after lapse of time (after 24 hours, 48 hours and 96 hours), respectively, Japanese Industrial Standards JIS K -5600-5-6: 1999 Adhesiveness of the fluororesin layer was evaluated based on “Coating General Test Method—Mechanical Properties of Coating Film—Adhesiveness (Cross Cut Method)”.
Cut the fluororesin layer at 1 mm intervals to form 100 (10 vertical × 10 horizontal) grids, and apply cellophane tape (trade name: CT-24, manufactured by Nichiban Co., Ltd.) to the grids. When the cellophane tape was peeled off after wearing, the number of grids remaining without peeling was examined. The results are shown in Table 4.

<Moisture and heat resistance test>
The sample was cut to A4 size and placed under conditions of 121 ° C., 2 atm, 100% RH for 24 hours, 48 hours, and 96 hours according to IEC60068-2-66.

<Weather resistance test>
Cut the sample into A4 size and use Super Xenon Weather Meter SX-75 (trade name) manufactured by Suga Test Instruments Co., Ltd.
・ Black panel temperature 63 ℃
・ Irradiance 60W / m ² (300 ~ 400nm)
-Water spray 18 minutes / 120 minutes-Irradiation surface 1000 hours, 2000 hours, and 3000 hours were put on the conditions of the base material sheet surface or the fluororesin layer.

  The back surface protection sheet of this invention is excellent in heat-and-moisture resistance, and is excellent in the durability in a humid-heat environment. The solar cell module excellent in safety and durability can be provided by fixing the protective sheet of the present invention to the solar cell module body to constitute the solar cell module.

DESCRIPTION OF SYMBOLS 10 Surface protection sheet 20 Back surface protection sheet 30 Sealing material 40 Solar cell 50 Solar cell module 60A-60C Back surface protection sheet 61 Base material sheet 62 Thermoplastic resin layer 63 Interlayer adhesive layer 64 Fluorine resin coat layer (fluorine resin layer)
65 Silica-deposited PET layer (gas barrier film layer)

Claims (4)

  A back protective sheet for a solar cell module, wherein a thermoplastic resin layer is laminated on one or both sides of a base sheet made of polyphenylene ether.   The solar cell module according to claim 1, wherein a thermoplastic resin layer is laminated on one surface side of the base sheet, and a fluororesin layer is laminated on the other surface side of the base sheet. Back surface protection sheet.   The back protective sheet for a solar cell module according to claim 1 or 2, wherein a gas barrier film layer is laminated between the base sheet and the thermoplastic resin layer.   The solar cell module by which the back surface protection sheet for solar cell modules of any one of Claims 1-3 is adhere | attached.

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