JP2011204880A - Protective sheet for solar cell module and the solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective sheet for solar cell modules having excellent electrical insulation properties.SOLUTION: The protective sheets 10A, 20A for solar cell modules include a syndiotactic polystyrene resin sheet 11, and an olefinic resin layer 12 stacked at a side of at least one surface 11a of the syndiotactic polystyrene resin sheet 11. In the protective sheets 10A, 20A for solar cell modules, the olefinic resin layer 12 contains a polyethylene resin, a polypropylene resin, and/or a cycloolefin resin. In the protective sheet for solar cell modules, a resin layer containing fluorine is stacked at a side of a surface opposite to the surface 11a onto which the olefinic resin layer 12 is stacked in the syndiotactic polystyrene resin sheet 11. A solar cell module uses the protection sheets 10A, 20A for solar cell modules.

Description

  The present invention relates to a protective sheet for a solar cell module and a solar cell module using 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 main structure of a solar cell module consists of the photovoltaic cell which is a photovoltaic device, the sealing material which encloses them in the airtight state, and a protective sheet. A surface protective sheet and a back surface protective sheet are bonded to the light receiving surface side (front surface side) and the back surface side of the encapsulant containing the solar battery cells, respectively. In the present specification, the surface protection sheet and the back surface protection sheet may be collectively referred to as “protection sheet”.
In order to provide the solar cell module with the weather resistance and durability that can withstand long-term use outdoors and indoors, the solar cell and sealing material are protected from wind and rain, moisture, dust, mechanical shock, etc. It is necessary to keep the inside of the module sealed from the outside air. For this reason, it is calculated | required that the said protective sheet for solar cell modules is excellent in a weather resistance.

In addition, due to the recent high performance of solar cell modules, the system voltage of solar cell modules is becoming 1000 V or more as a standard, and high electrical insulation is also required for protective sheets for solar cell modules.
A conventional protective sheet for a solar cell module has been proposed in which bubbles are included in an adhesive layer that bonds a white plastic film and a gas barrier vapor-deposited film in order to enhance electrical insulation (see Patent Document 1).

JP 2008-270238 A

However, the electrical insulation of the solar cell module protective sheet proposed in Patent Document 1 is still insufficient.
This invention is made | formed in view of the said situation, Comprising: It aims at providing the protection sheet for solar cell modules excellent in electrical insulation.

In order to achieve the above object, the present invention is characterized by having a syndiotactic polystyrene resin sheet and an olefin-based resin layer laminated on at least one side of the syndiotactic polystyrene resin sheet. A protective sheet for a solar cell module is provided.
In the solar cell module protective sheet of the present invention, the olefin-based resin layer preferably contains a polyethylene resin, a polypropylene resin, and / or a cycloolefin resin.
In the protective sheet for a solar cell module of the present invention, a fluorine-containing resin layer is laminated on the side of the syndiotactic polystyrene resin sheet opposite to the surface on which the olefin resin layer is laminated. It is preferable.
Furthermore, this invention provides the solar cell module which uses the said protection sheet for solar cell modules which concerns on this invention.

The protective sheet for a solar cell module of the present invention has a syndiotactic polystyrene resin sheet and an olefin-based resin layer laminated on at least one surface side of the syndiotactic polystyrene resin sheet. Excellent.
Moreover, in the solar cell module using the said protection sheet for solar cell modules of this invention, it can respond | correspond to the system voltage which a solar cell system requires.

It is a schematic sectional drawing which shows 1st embodiment of the protection sheet for solar cell modules of this invention. It is a schematic sectional drawing which shows 2nd embodiment of the protection sheet for solar cell modules of this invention. It is a schematic sectional drawing which shows an example of a solar cell module.

[Protective sheet for solar cell module]
Hereinafter, embodiments of the protective sheet for a solar cell module of the present invention will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

(1) 1st embodiment FIG. 1: is a schematic sectional drawing which shows 1st embodiment of the protection sheet for solar cell modules of this invention.
The solar cell module protective sheets 10 </ b> A and 20 </ b> A of the first embodiment include a syndiotactic polystyrene resin sheet 11 and an olefin-based resin layer 12 laminated on one surface 11 a of the syndiotactic polystyrene resin sheet 11. It is roughly structured.
The solar cell module protective sheet 10A according to the first embodiment is applied to the back surface protective sheet of the solar cell module with the olefin-based resin layer 12 as the sealing material side of the solar cell module. The solar cell module protective sheet 20A of the first embodiment is applied to the surface protective sheet of the solar cell module with the olefin-based resin layer 12 as the sealing material side of the solar cell module.

The syndiotactic polystyrene resin sheet 11 is not particularly limited as long as it is a sheet or film made of a polystyrene resin having a syndiotactic structure (hereinafter sometimes referred to as “SPS”). The syndiotactic structure is a three-dimensional structure in which the three-dimensional structure is a syndiotactic structure, that is, a phenyl group or a substituted phenyl group that is a side chain with respect to the main chain formed from a carbon-carbon bond is alternately located in the opposite direction. The tacticity thereof is quantified by an isotope carbon nuclear magnetic resonance method ( ¹³ C-NMR method). ^The tacticity measured by the ¹³ C-NMR method is the abundance ratio of a plurality of consecutive structural units, for example, 2 dyads (2 doublings), 3 cases triads (3 doublings), 5 In the case of individual, it can be indicated by pentad (pentad), but as the polystyrene resin having a syndiotactic structure in the present invention, it is 75 mol% or more with racemic dyad, or 30 mol% or more with racemic pentad. Polystyrene resins having a syndiotacticity of

The molecular weight of the SPS is not particularly limited, but the weight average molecular weight is preferably 10,000 or more, more preferably 50,000 or more. Furthermore, the molecular weight distribution is not particularly limited in its width, and SPS having various molecular weight distributions can be used.
The glass transition temperature (Tg) of the SPS is not particularly limited, but is preferably 80 to 120 ° C. from the viewpoint of film forming properties.
Although melting | fusing point (Tm) of the said SPS is not specifically limited, 230-350 degreeC is preferable from a film forming viewpoint, 240-330 degreeC is more preferable, 250-320 degreeC is further more preferable.

  The thickness of the syndiotactic polystyrene resin sheet 11 may be adjusted based on the electrical insulation required by the solar cell system. Usually, the thickness of the sheet is preferably in the range of 10 to 300 μm, and lightweight. And from a viewpoint of electrical insulation, it is more preferable that it is the range of 20-200 micrometers.

  Preferable examples of the syndiotactic polystyrene resin sheet 11 include, for example, XAREC (trade name) manufactured by Idemitsu Kosan Co., Ltd.

Further, the syndiotactic polystyrene resin sheet 11 can be subjected to a surface modification treatment for enhancing weather resistance, moisture resistance, and the like. For example, by depositing silica (SiO ₂ ), aluminum (Al), alumina (Al ₂ O ₃ ), and the like on the syndiotactic polystyrene resin sheet 11, the weather resistance and moisture resistance of the protection sheets for solar cell modules 10A and 20A. Etc. can be enhanced. Note that the vapor deposition treatment of silica, aluminum, alumina, or the like may be performed on both surfaces of the syndiotactic polystyrene resin sheet 11 or only on one of the surfaces.

The olefin resin layer 12 contains a layer made of an olefin resin.
The olefin resin layer 12 can be used for adhesion with a sealing material constituting the solar cell module. The olefin-based resin layer 12 is laminated on one surface 11a of the syndiotactic polystyrene resin sheet 11 to form the outermost layer of the solar cell module protective sheets 10A and 20A, thereby sealing the sealing material constituting the solar cell module. The solar cell module protective sheets 10A and 20A can be bonded to the stop surface. The olefin resin layer 12 can be bonded to the sealing material of the solar cell module by hot pressing at 50 to 200 ° C., and is firmly bonded to the sealing material.

The said olefin resin has electrical insulation, and the olefin resin generally used in the protection sheet for solar cell modules is selected.
Specific examples of the olefin resin include low density polyethylene (LDPE, density: 0.910 g / cm ³ or more, less than 0.930 g / cm ³ ), medium density polyethylene (MDPE, density: 0.930 g / cm ³ or more, 0.942 g / cm ³ ), polyethylene resins such as high density polyethylene (HDPE, density: 0.942 g / cm ³ or more); polypropylene resin (PP); olefin elastomer (TPO), cycloolefin resin (COP), Ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl acetate-maleic anhydride copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester-maleic anhydride copolymer, etc. Is mentioned. Especially, it is preferable that it is a low density polyethylene resin, a polypropylene resin, or a cycloolefin resin from an electrical insulating viewpoint.

The olefin resin layer 12 may be composed of only one layer composed of the olefin resin as described above, or may be a laminate of two or more layers composed of olefin resin.
When two or more layers made of olefin resin are laminated, the two or more layers made of olefin resin are layers made of different olefin resins even if they are layers made of the same olefin resin. May be.
Further, the method for laminating two or more olefin-based resins is not particularly limited as long as the effect of the present invention is not impaired, and an adhesive layer is provided between two or more olefin-based resin layers. And two or more olefinic resin layers may be laminated, and a layer composed of two or more olefinic resins by extrusion forming using a T-die extruder or T-die film forming machine, Direct lamination without an adhesive layer may also be used.
Here, the adhesive layer is not particularly limited as long as it contains an adhesive having adhesiveness to a layer composed of two or more olefin-based resins. Examples of the adhesive include acrylic adhesives and urethane-based adhesives. Examples thereof include an adhesive, an epoxy-based adhesive, and a polyester-based adhesive. These adhesives may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, in order to improve adhesiveness, you may corona-treat and / or chemical-treat the surface by the side of the said adhesion layer of the layer which consists of an olefin resin.

  Among them, the olefin-based resin layer 12 is composed of only a low-density polyethylene resin layer; composed of only a polypropylene resin layer; composed of only a cycloolefin resin layer; composed of a low-density polyethylene layer and a cycloolefin resin layer. Examples include: a layer composed of a polypropylene layer and a cycloolefin layer; a layer composed of a polypropylene layer, a low density polyethylene layer and a cycloolefin resin layer; a combination of the above and an adhesive layer.

  What is necessary is just to adjust suitably the thickness of the olefin resin layer 12 whole based on the kind of olefin resin which comprises the olefin resin layer 12, and it is preferable that it is normally the range of 10 micrometers-300 micrometers. More specifically, when the olefin-based resin layer 12 is composed only of a low-density polyethylene layer, the thickness is preferably in the range of 10 to 250 μm from the viewpoint of lightness and electrical insulation, and is preferably 20 to 20 μm. The range of 200 μm is more preferable, and the range of 50 to 150 μm is more preferable.

  The method for laminating the olefin-based resin layer 12 on one surface 11a of the syndiotactic polystyrene resin sheet 11 is not particularly limited as long as it does not impair the effects of the present invention. As shown in FIG. The syndiotactic polystyrene resin sheet 11 and the olefin resin layer 12 can be laminated by further providing an adhesive layer 13 between the tactic polystyrene resin sheet 11 and the olefin resin layer 12.

The adhesive layer 13 preferably includes an adhesive having adhesiveness to the syndiotactic polystyrene resin sheet 11 and the olefin resin layer 12.
The adhesive is not particularly limited, and examples thereof include an acrylic adhesive, a urethane adhesive, an epoxy adhesive, and a polyester adhesive. These adhesives may be used individually by 1 type, and may be used in combination of 2 or more type.
In order to improve adhesiveness, the surface of the syndiotactic polystyrene resin sheet 11 and the olefin resin layer 12 on the adhesive layer side may be subjected to corona treatment and / or chemical treatment.

The electrical insulating properties of the solar cell module protective sheets 10A and 20A of the present invention are determined by a partial discharge start voltage measured by a partial discharge test.
The partial discharge test can be measured by an alternative test method based on the EN50178 standard.
The partial discharge start voltage of the solar cell module protective sheets 10A and 20A of the present invention is preferably 1000 V or higher. When the solar cell module protection sheet 10A or 20A has a measured value of the partial discharge start voltage of 1000V or more, even if the system voltage of the solar cell module using the solar cell module protection sheet 10A or 20A is 1000V or more It can respond sufficiently.

  Since the protective sheet 10A, 20A for the solar cell module of the present invention as the first embodiment described above is composed of the syndiotactic polystyrene resin sheet 11 and the olefin resin layer 12 laminated. , Electrical insulation can be enhanced.

(2) Second Embodiment FIG. 2 is a schematic cross-sectional view showing a second embodiment of the solar cell module protective sheet of the present invention. In FIG. 2, the same components as those of the solar cell module protection sheets 10A and 20A shown in FIG.
The protective sheets 10B and 20B for the solar cell module of the second embodiment are formed by laminating a syndiotactic polystyrene resin sheet 11, an olefin resin layer 12, and an olefin resin layer 12 of the syndiotactic polystyrene resin sheet 11. And a fluorine-containing resin layer 14 further provided on the surface 11b opposite to the surface 11a.
By providing the fluorine-containing resin layer 14 as a cured layer, weather resistance and chemical resistance can be improved in addition to the effects of the solar cell module protective sheets 10A and 20A of the first embodiment.
The solar cell module protective sheet 10B according to the second embodiment is applied to the back surface protective sheet of the solar cell module with the olefin-based resin layer 12 as the sealing material side of the solar cell module. Further, the solar cell module protective sheet 20B of the second embodiment is applied to the surface protective sheet of the solar cell module with the olefin-based resin layer 12 as the sealing material side of the solar cell module.

  The thickness of the fluorine-containing resin layer 14 is set in consideration of weather resistance, chemical resistance, weight reduction, and the like, preferably in the range of 5 μm to 50 μm, and more preferably in the range of 10 μm to 30 μm.

  The fluorine-containing resin layer 14 is not particularly limited as long as it contains fluorine. As what forms this layer containing fluorine, the coating film formed by apply | coating the sheet | seat which has fluorine-containing resin, the coating material which has fluorine-containing resin, etc. are mentioned, for example. Among these, from the viewpoint of making the fluorine-containing resin layer 14 thinner in order to reduce the weight of the solar cell module protective sheets 10B and 20B, a coating film formed by applying a paint having a fluorine-containing resin is preferable.

When the fluorine-containing resin layer 14 is a sheet having a fluorine-containing resin, the fluorine-containing resin layer 14 is laminated on the syndiotactic polystyrene resin sheet 11 via an adhesive layer. The adhesive layer preferably includes an adhesive having adhesiveness to the syndiotactic polystyrene resin sheet 11 and the fluorine-containing resin layer 14.
As the adhesive constituting the adhesive layer, polyacrylic adhesives, polyurethane adhesives, epoxy adhesives, polyester adhesives, polyester polyurethane adhesives, and the like are used. These adhesives may be used individually by 1 type, and may be used in combination of 2 or more type.

  On the other hand, when the fluorine-containing resin layer 14 is a coating film formed by applying a paint having a fluorine-containing resin, the paint containing the fluorine-containing resin is usually applied to the syndiotactic polystyrene resin sheet 11 without using an adhesive layer. The fluorine-containing resin layer 14 is laminated on the syndiotactic polystyrene resin sheet 11 by applying directly.

As the sheet having a fluorine-containing resin, for example, a sheet obtained by processing a resin mainly composed of polyvinyl fluoride (PVF), ethylene chlorotrifluoroethylene (ECTFE), or ethylene tetrafluoroethylene (ETFE) is used. .
As a resin mainly composed of PVF, for example, “Tedlar (trade name, EI du
Pont de Nemours and Company) "is used.
For example, “Halar (trade name, manufactured by Solvay Solexis)” is used as the resin mainly composed of ECTFE.
As the resin mainly composed of ETFE, for example, “Fluon (trade name, manufactured by Asahi Glass Co., Ltd.)” is used.

  The paint containing the fluorine-containing resin is not particularly limited as long as it is dissolved in a solvent or dispersed in water and can be applied.

  As the fluorine-containing resin contained in the paint, it is preferable to use a fluoroolefin resin having a curable functional group. Examples of the functional group include a hydroxyl group, a carboxyl group, an amino group, and a glycidyl group.

Specifically, as the fluoroolefin resin, “LUMIFLON (trade name, manufactured by Asahi Glass Co., Ltd.)”, “CEFRAL COAT (trade name, manufactured by Central Glass Co., Ltd.)”, “FLUONATE (trade name, manufactured by DIC Corporation)”, etc. Examples thereof include polymers mainly composed of chlorotrifluoroethylene (CTFE) and polymers mainly composed of tetrafluoroethylene (TFE) such as “ZEFFLE (trade name, manufactured by Daikin Industries, Ltd.)”.
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 preferable, and “LUMIFLON” and “ZEFFLE” are most preferable.

“LUMIFLON” is an amorphous resin containing CTFE, several types of specific alkyl vinyl ethers (VE), and hydroxyalkyl vinyl ethers as main structural units. A resin having a monomer unit of hydroxyalkyl vinyl ether such as “LUMIFLON” is preferable because it is excellent in solvent solubility, cross-linking reactivity, substrate adhesion, pigment dispersibility, hardness and flexibility.
"ZEFFLE" is a copolymer of TFE and organic solvent-soluble hydrocarbon olefins, especially those containing hydrocarbon olefins with highly reactive hydroxyl groups, solvent-soluble, cross-linking reactivity, adhesion to substrates This is preferable because of its excellent properties and pigment dispersibility.

  Examples of the copolymerizable monomer that forms 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, and alkyl vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether are used.

  The coating material may contain a solvent, a crosslinking agent, and a catalyst in addition to the above-described fluorine-containing resin, 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 it does not impair the effects 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 selected from the group consisting of one or more organic solvents is preferably used.
Among these solvents, from the viewpoints of solubility of the components contained in the paint and low persistence in the coating film (low boiling point temperature), the solvent is any selected from xylene, cyclohexanone, or MEK. A solvent containing one or more organic solvents is preferred.

  The pigment contained in the paint is not particularly limited as long as the effect of the present invention is not impaired. For example, titanium dioxide, carbon black, perylene pigment, mica, zinc oxide, aluminum oxide, silica, and the like are used. Specifically, as a pigment, in order to impart durability, “Ti-Pure R-105 (trade name, manufactured by EI du Pont de Nemours and Company), which is a rutile type titanium dioxide treated with silicon oxide. And “CAB-O-SIL TS-720 (trade name, manufactured by Cabot)”, which is a hydrophobic silica in which the hydroxyl group on the silica surface is modified by the surface treatment of dimethylsilicone, is preferably used.

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 the effects of the present invention are not impaired, and metal chelates, silanes, isocyanates, or melamines are preferably used. When it is assumed that the solar cell module protection sheets 10B and 20B are 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, the coating composition is prepared by mixing a fluorine-containing resin, a pigment, a crosslinking agent, a solvent, and a catalyst.
The composition ratio of the composition is such that the content of the fluorine-containing resin is preferably 3 to 80% by mass, more preferably 25 to 50% by mass, and the pigment content is 5 to 60, based on 100% by mass of the entire coating. % By mass is preferred, 10-30% by mass is more preferred, and the solvent content is preferably 20-80% by mass, more preferably 25-65% by mass.

  Further, as the catalyst, for example, dioctyl dilaurate tin is used, and this catalyst is used for promoting the crosslinking between the fluorine-containing resin and the isocyanate.

As a method of applying the paint to the syndiotactic polystyrene resin sheet 11, a known method is used, and for example, it may be applied so as to have a desired thickness with a rod coater.
The drying temperature of the paint applied to the syndiotactic polystyrene resin sheet 11 may be a temperature that does not impair the effects of the present invention. From the viewpoint of reducing the influence on the syndiotactic polystyrene resin sheet 11, 50 to 130 ° C. It is preferable that it is the range of these.

[Solar cell module]
As shown in the schematic diagram of FIG. 3, the solar cell module of the present invention has a solar cell module protective sheet 10, 20 according to the present invention on a sealing surface composed of a sealing material 30 containing solar cells 40. By laminating, the solar battery cell 40 and the sealing material 30 in the solar battery module 100 are protected from wind, rain, moisture, dust, mechanical shock, etc., and the inside of the solar battery module 100 is shielded from the outside air. It can be kept sealed.
Moreover, the solar cell module 100 using the said protection sheet for solar cell modules 10 and 20 of this invention can respond | correspond to the system voltage which a solar cell system requires.

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

[Example 1]
An adhesive (Takelac A-515 (trade name; manufactured by Mitsui Chemicals)) and Takenate A-3 (trade name) on XAREC-C122 (trade name, manufactured by Idemitsu Kosan Co., Ltd.) as a syndiotactic polystyrene resin sheet having a thickness of 50 μm. ; Manufactured by Mitsui Chemicals Co., Ltd.) in a ratio of 9: 1 (weight ratio) was applied with a rod coater and dried at 80 ° C. for 1 minute to form an adhesive layer having a thickness of 10 μm. A 75 μm-thick low density polyethylene (LDPE) film (density: 0.922 g / cm ³ ) was laminated on the adhesive layer to form a syndiotactic polystyrene resin sheet / low density polyethylene film laminate.
Further, an adhesive similar to the above was applied onto a cycloolefin resin (COP) film having a thickness of 50 μm with a rod coater and dried at 80 ° C. for 1 minute to form an adhesive layer having a thickness of 10 μm. A low-density polyethylene film surface of the syndiotactic polystyrene resin sheet / low-density polyethylene film laminate prepared above was laminated on this adhesive layer to produce a protective sheet for a solar cell module of Example 1.

[Example 2]
A protective sheet for a solar cell module of Example 2 was produced in the same manner as Example 1 except that the thickness of the low density polyethylene film was changed to 125 μm.

[Example 3]
On one side of the same syndiotactic polystyrene resin sheet as in Example 1, a paint containing a fluorine-containing resin was applied with a rod coater Meyer bar, dried at 130 ° C. for 1 minute, and a fluorine-containing resin layer having a thickness of 15 μm was laminated. Then, a fluorine-containing resin laminated syndiotactic polystyrene resin sheet was produced. The paint containing fluorine-containing resin is 100 parts by mass of LUMIFLON LF-200 (trade name, manufactured by Asahi Glass Co., Ltd., solid content concentration: 60% by mass), and Desmodur N3300 (trade name, manufactured by Bayer, solid) as an aliphatic isocyanate-based crosslinking agent. 10 parts by mass of a partial concentration of 100% by mass, 0.0001 part by mass of tin dioctyl dilaurate as a catalyst, and Ti-Pure R-105 (trade name, EI du Pont de Nemours and Company) as titanium pigment. (Manufactured) A fluorine-containing resin solution mixed with 30 parts by mass was used.
A protective sheet for a solar cell module of Example 3 was produced in the same manner as in Example 1 except that the syndiotactic polystyrene resin sheet was changed to this fluorine-containing resin-laminated syndiotactic polystyrene resin sheet.

[Example 4]
A protective sheet for a solar cell module of Example 4 was produced in the same manner as in Example 1 except that the low density polyethylene was changed to a random polypropylene (PP) film having a thickness of 75 μm.

[Example 5]
A protective sheet for a solar cell module of Example 5 was produced in the same manner as Example 1 except that the low density polyethylene was changed to 150 μm in thickness.

[Example 6]
A protective sheet for a solar cell module of Example 6 is produced in the same manner as in Example 1 except that the low density polyethylene is changed to a three-layer coextruded film of random polypropylene 50 μm / low density polyethylene 75 μm / cycloolefin resin 50 μm. did. In the three-layer coextruded film, the surface on which the random polypropylene was laminated was the syndiotactic polystyrene resin sheet side.

[Comparative Example 1]
A protective sheet for a solar cell module of Comparative Example 1 was produced in the same manner as in Example 1, except that the low density polyethylene was changed to polyethylene terephthalate (PET) having a thickness of 75 μm.

<Electrical insulation evaluation>
Using the protective sheets for solar cell modules of Examples 1 to 6 and Comparative Example 1, partial discharge tests were performed. Using a KPD2050 (trade name, manufactured by Kikusui Electronics Co., Ltd.) as a tester, the partial discharge start voltage was measured according to EN50178. The specific test conditions were as follows: maximum applied voltage: 1.5 kV, maximum applied voltage time: 5 seconds, boost time: 10 seconds, threshold: disappearance voltage 1 pc.
The results are shown in Table 1.

  From the above results, the protective sheets for solar cell modules of Examples 1 to 6 according to the present invention have a higher partial discharge start voltage and excellent electrical insulation than the protective sheet for solar cell modules of Comparative Example 1. It could be confirmed.

10, 10A, 10B Back surface protection sheet for solar cell module 20, 20A, 20B Surface protection sheet for solar cell module 11 Syndiotactic polystyrene resin sheet 12 Olefin resin layer 13 Adhesive layer 14 Fluorine-containing resin layer 30 Sealing material 40 Sun Battery cell 100 solar cell module

Claims (4)

  A protective sheet for a solar cell module, comprising a syndiotactic polystyrene resin sheet and an olefin-based resin layer laminated on at least one surface side of the syndiotactic polystyrene resin sheet.   The said olefin resin layer contains a polyethylene resin, a polypropylene resin, and / or a cycloolefin resin, The protection sheet for solar cell modules of Claim 1 characterized by the above-mentioned.   The fluorine-containing resin layer is laminated | stacked on the side of the surface on the opposite side to the surface where the said olefin resin layer was laminated | stacked of the said syndiotactic polystyrene resin sheet of Claim 1 or 2 characterized by the above-mentioned. Protection sheet for solar cell module.   The solar cell module which uses the protection sheet for solar cell modules as described in any one of Claims 1-3.

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