JP5965004B2 - PID countermeasure film for solar cell and PID countermeasure solar cell module using the same - Google Patents

Description

  The present invention relates to a PID countermeasure film and a solar cell module using the film, which prevents a solar cell element in a solar cell module from being deteriorated by an alkali metal released from a cover glass.

  As a typical configuration of the solar cell module, the solar cell element is narrowed by a pair of adhesive films from both sides thereof, and a transparent base material such as glass is fixed to the adhesive film on the sunlight receiving side, and the back side is bonded. A so-called spar straight structure in which a protective material (back sheet) is fixed to the film is known. Alternatively, there is a so-called glass / glass structure module in which both sides of the module are sandwiched between cover glasses. A double-sided power generation cell may be applied to improve module conversion efficiency. In such a configuration, the adhesive film and the power generation element protective film are required to have various properties such as adhesiveness and weather resistance, and particularly the sunlight receiving side is required to have high transparency, and the adhesive satisfying these requirements. Films are known from, for example, Patent Documents 1 to 3.

  In addition to these characteristics, it is necessary to take measures against power generation deterioration due to the so-called PID (Potential Induced Degradation) phenomenon in which the amount of system power generation decreases by several tens of percent in six months to several years. Patent Document 1 introduces a technique of laminating a highly insulating film such as a fluorine film between a cell and a cover glass. Alternatively, Patent Document 2 introduces a surface treatment technique using a silane coupling agent on the glass surface in order to reduce the influence of alkali metal released from the glass. Further, Patent Document 3 includes a layer made of a cyclic olefin resin and a layer made of an ethylene-vinyl acetate copolymer, and at least one layer made of the ethylene-vinyl acetate copolymer has the cyclic structure. A solar cell module is disclosed which is disposed on the side far from the solar cell with reference to a layer made of olefin resin.

  However, it is said that a reduction in the power generation deterioration rate was observed with the uniquely assembled PID test method without clarifying the PID phenomenon occurrence mechanism. Despite the fact that the certification test is 85 ° C, 85RH%, 1000 hours as a guarantee of 20 years, the conditions that are assumed to be used in power plants exposed to high voltage are at least 1000 hours. However, these tests are 100 hours, and are not intended tests. There has been no invention in the field that shows the result of whether power generation does not deteriorate under laboratory test conditions corresponding to 20 years.

  As a result of earnestly examining the generation mechanism of the PID phenomenon, the inventors have found out the following from the result of the failure analysis of the module that became the PID phenomenon. In a widely used P-type silicon semiconductor, when sodium ions deposit and cover about 15% of the total surface area of the silicon cell on the white glass side, a metallic sodium layer is formed, and the n layer of the pn structure is converted to P, As a result, it was clarified by the breakdown analysis of the module that developed the PID phenomenon in the real field that the characteristics of the semiconductor, which were manifested by the pn junction in terms of quantum mechanics, were lost, the photoelectric effect was not exhibited, and the power generation was stopped. . It was also found that power generation deterioration was caused not only by deterioration of the silicon cell as a semiconductor but also by a decrease in the current collecting ability of the surface electrode and interconnector electrons. The decrease in the current collecting ability is caused by the acetic acid released by the deterioration of the EVA sealing material dissolving the solder component and the glass component added as an adhesive between the surface electrode and the cell. I found out. It was found that the amount of acetic acid at the lower corner of the domestic solar cell module operating for 21 years (the light receiving surface side of the edge portion on the module corner side of the silicon cell at the corner) was 120 μg / g. In the laboratory, the amount of acetic acid at the edge of the cell using EVA made by Mitsui Chemicals with a module of the same structure of 20 cm square was found to correspond to 2500 h in a dump heat test of 85 ° C. and 85 RH%. .

  Therefore, the PID test conditions are not the conditions such as 60 ° C., 85 RH%, 96 h, and −1000 V, which are currently under consideration in standardization, but the dump heat test is applied with −1000 V at 85%, 85 RH%, and 2500 h. It was found that this condition was a test condition corresponding to 20 years.

  The protective film for a solar cell module described in Patent Document 3 uses a cyclic olefin-based resin, and has a glass transition temperature in a wide range of 80 ° C. to 250 ° C., and a film thickness in a wide range of 5 μm to 200 μm. Within the range described in such a publication, the film has poor moldability, and even if it can be molded, it is almost impossible to be put into practical use. Moreover, the solar cell module tends to increase in size, and the size is 2 m × 4 m (vertical × horizontal) or more. The protective film for a solar cell module described in Patent Document 3 cannot be formed as a film for a solar cell module having such a size.

Special table 2013-502051 JP2008-273783 JP 2006-198922 A

  The present invention is a PID countermeasure film for solar cells that is excellent in the barrier property of alkali metal ions released from the cover glass of the solar cell module that solves the above problems, and that is excellent in heat resistance and light resistance, and PID countermeasures using the same. An object is to provide a solar cell module.

<1> 1st invention The PID countermeasure film of 1st invention for solving the said subject is a PID countermeasure film laminated | stacked in the middle of the solar cell power generation element and cover glass in a solar cell module, and is width | variety. there the glass transition temperature of 75 ° C. or more 80cm or more, a cyclic olefin resin film is 95 ° C. or less, the cyclic olefin resin, and ethylene, a copolymer consisting of a cyclic olefin, the copolymer Is characterized in that it is only a copolymer having a glass transition temperature of 75 ° C. or higher and a film thickness of 60 μm or more and 100 μm or less.

  The cyclic olefin resin film of the present invention (hereinafter abbreviated as “PID countermeasure film”) is provided between the solar cell power generation element and the cover glass in the solar cell module. The PID countermeasure film of the present invention has a glass transition temperature of 75 ° C. or higher and 95 ° C. or lower, preferably 80 ° C. or higher and 90 ° C. or lower. If the glass transition temperature is less than 75 ° C., the film is partially fluidized by the molding heat of the laminating process, which is a cross-linking reaction process of the solar cell, and a scar formed of round wrinkles is formed on the light receiving surface side of the module. When it exceeds 95 ° C., when the film is wound into a roll, cracks are generated from the side surface portion, and the film cannot be wound. Furthermore, after about one week after the solar cell module is molded, innumerable microcracks are generated in the solar cell module, resulting in an appearance defect, which is not preferable.

  In addition, the PID countermeasure film of the present invention has a thickness of 40 μm to 200 μm, preferably 60 μm to 100 μm, and more preferably 70 μm to 90 μm. When the film thickness is less than 40 μm, the film strength is remarkably lowered, and the film may be broken by the tension applied in the film winding process, which is not preferable. Moreover, since a crack will arise in the part close | similar to the branch diameter of a film winding when thickness exceeds 200 micrometers, it is unpreferable. In addition, it is not preferable to use a thick film having a thickness of more than 200 μm because innumerable microcracks are generated on the light receiving surface side of the molded solar cell module 24 hours after forming the film, resulting in product appearance defects.

  Moreover, the PID countermeasure film of this invention can manufacture the thing (width 80cm or more) of the size which can be used with respect to the enlarged solar cell module with the size of 2mx4m (length x width) or more. Thus, even a large PID countermeasure film can be provided without any cracks. Moreover, such a large-sized PID countermeasure film cannot be realized by conventional techniques.

  The PID countermeasure film of the present invention prevents sodium ions and potassium ions released from the cover glass of the solar cell module from moving to the surface of the power generation element (crystal cell, solar cell, etc.) in the solar cell module. Therefore, it is possible to completely prevent power generation deterioration due to PID, which frequently occurs in mega solar power plants. Moreover, the PID countermeasure of this invention is excellent in the weather resistance, heat resistance, transparency, waterproofness, and moisture resistance required as an adhesive film for solar cell modules. Accordingly, it is possible to extend the life of the solar cell module. Furthermore, it is possible to provide a solar cell module having a good appearance with no cracks or the like in the sealed portion between the solar cell and the cover glass in the solar cell module.

  The PID countermeasure film of the present invention tends to be easily broken, and can be wound in a state where a protective film having both elasticity and strength such as a polyethylene material is attached. Alternatively, it is possible to prevent winding of the film roll using fine powder such as silica.

PID measures the film of the present invention, the ring-like olefin resin, characterized in that it is a copolymer of ethylene and / or α- olefin and cyclic olefin.

Ring-like olefin resin, and ethylene and / or α- olefins are PID measures the film is a copolymer of a cyclic olefin, of ethylene and / or α- olefins, and most are single use of ethylene preferable.

According to the present invention, the cyclic olefin resin is a copolymer of ethylene and a cyclic olefin. To improve the weather resistance of the PID measures sheet becomes further possible by using a cyclic olefin copolymer, in addition to the effect that PID to completely prevent, effect appears to say to improve the life of the film . Therefore, the lifetime of the solar cell module using this film is further improved.

<2> PID measures film of the second aspect of the invention the second invention, Oite to the first aspect of the present invention, the PID measures film is equal to or integrated with the sealing film.

The PID countermeasure film of the second invention is integrated with the sealing film. As the sealing film, a sealing film used for a solar cell module such as an EVA resin film, a PVB resin film, or an ionomer film can be used.

According to the 2nd invention, since the PID countermeasure film and the sealing film are integrated, in the process of manufacturing the solar battery module, the process of laminating each member on the solar battery cell can be simplified.

<3> solar cell module of the third aspect of the present invention a third aspect is a feature that Oite the first or second aspect of the invention, the PID measures film is provided between the EVA sealing film and the cover glass To do.

Solar cell module of the present invention has a structure in which a PID measures film of the first or second aspect of the invention between the sealing film b for the existing solar cell cover glass. The solar cell module using the PID countermeasure film of the present invention is laminated with a cover glass, an existing sealing film, a film of the present invention, an existing sealing film, a solar cell, an existing sealing film, and a back material in this order. . After the lamination, the solar cell module for PID countermeasure is obtained by press molding with heat of 130 ° C. or more to bond each interface. As the existing sealing film, it is generally preferable to use an EVA sealing material. The cover glass may be white plate glass that releases sodium ions, or may be chemically strengthened glass in which the glass surface is replaced with potassium ions. Since chemically strengthened glass has high strength, it can be thinned, and a lightweight solar cell module can be easily manufactured.

  In the solar cell module obtained by the configuration of the present invention, PID does not occur at all, the waterproofness as a product is enhanced, and the weather resistance is ensured for a very long time. The module life can be extended.

<4> solar cell module of the fourth aspect of the present invention a fourth aspect of the present invention, PID measures film of the first or second aspect, characterized in that covers at least 85% of the crystalline cell area.

  As described above, it is sufficient that the film of the present invention is laminated at least on the upper part of the solar battery cell, and at least 85% or more of the crystal cell area is covered. When the area covering the area of the crystal cell with the PID countermeasure film of the present invention is less than 85%, sodium ions and potassium ions contained in the cover glass adhere to the solar cell and PID is generated.

  By using the PID countermeasure film of the present invention and covering 85% or more of the surface area of the crystalline cell of the solar cell module, PID of the solar cell module can be reliably prevented.

It is a schematic cross section which shows the structural example 1 of the solar cell module of this invention. It is a schematic cross section which shows the structural example 2 of the solar cell module of this invention. Explanatory drawing of the degree of deterioration of the solar cell module of this invention and the conventional solar cell. It is a schematic cross section which shows the structure of the conventional solar cell module. It is explanatory drawing of the structure of the solar cell module of Example 5. FIG.

  Hereinafter, embodiments of a PID countermeasure film of the present invention and a solar cell module using the film will be described with reference to FIGS. 1 to 3.

<1> Solar Cell PID Countermeasure Film The solar cell PID countermeasure film of the present invention is an adhesive film that prevents alkali metal from moving to the solar cell power generation element in the solar cell module, and is an amorphous cyclic olefin-based film. The copolymer is formed into a film shape. The PID countermeasure film for solar cell according to the present invention will be described in detail below.

<1-1> Cyclic Olefin Resin Cyclic olefin resin is a polymer or copolymer having a glass transition temperature of 75 ° C. or higher and 95 ° C. or lower and containing a structural unit derived from cyclic olefin in the main chain. If it is, it will not be specifically limited. Examples thereof include addition polymers of cyclic olefins or hydrogenated products thereof, addition copolymers of cyclic olefins with ethylene and / or α-olefins, or hydrogenated products thereof. A cyclic olefin resin can be used individually by 1 type, or can also use 2 or more types together. Further, the glass transition temperature of the cyclic olefin resin used in the present invention was measured by DSC at a temperature rising rate of 10 ° C./min in accordance with JIS K7121 “Method for measuring the transition heat of plastic”.

  The cyclic olefin-based resin includes those obtained by grafting and / or copolymerizing an unsaturated compound having a polar group in the polymer or the copolymer containing a structural unit derived from a cyclic olefin in the main chain.

  Examples of the polar group include a carboxyl group, an acid anhydride group, an epoxy group, an amide group, an ester group, and a hydroxyl group. Examples of the unsaturated compound having a polar group include (meth) acrylic acid and maleic acid. Acid, maleic anhydride, itaconic anhydride, glycidyl (meth) acrylate, alkyl (meth) acrylate (carbon number 1-10) ester, maleic acid alkyl (carbon number 1-10) ester, (meth) acrylamide, (meta ) 2-hydroxyethyl acrylate.

  As the cyclic olefin resin according to the present invention, a commercially available resin may be used. Examples of commercially available cyclic olefin resins include TOPAS (registered trademark) (manufactured by TOPAS Advanced Polymers), Apel (registered trademark) (manufactured by Mitsui Chemicals), and a metathesis catalyst using a cyclic olefin component as a starting material. Examples of cyclic olefin polymers that are produced by ring-opening polymerization and hydrogenated and are commercially available include ZEONEX (registered trademark) (manufactured by ZEON CORPORATION), ZEONOR (registered trademark) (manufactured by ZEON CORPORATION), Arton (registered trademark). ) (Manufactured by JSR).

（式中、Ｒ１〜Ｒ１２は、それぞれ同一でも異なっていてもよく、水素原子、ハロゲン原子、及び、炭化水素基からなる群より選ばれるものであり、
Ｒ９とＲ１０、Ｒ１１とＲ１２は、一体化して２価の炭化水素基を形成してもよく、
Ｒ９又はＲ１０と、Ｒ１１又はＲ１２とは、互いに環を形成していてもよい。
また、ｎは、０又は正の整数を示し、
ｎが２以上の場合には、Ｒ５〜Ｒ８は、それぞれの繰り返し単位の中で、それぞれ同一でも異なっていてもよい。）
α−オレフィンとしては、特に制限はないが炭素数２〜２０のα−オレフィンが好ましい。例えば、プロピレン、１−ブテン、１−ペンテン、１−へキセン、３−メチル−１−ブテン、３−メチル−１−ペンテン、３−エチル−１−ペンテン、４−メチル−１−ペンテン、４−メチル−１−へキセン、４，４−ジメチル−１−ヘキセン、４，４−ジメチル−１−ペンテン、４−エチル−１−へキセン、３−エチル−１−ヘキセン、１−オクテン、１−デセン、１−ドデセン、１−テトラデセン、１−ヘキサデセン、１−オクタデセン、１−エイコセン等を挙げることができる。また、これらのα−オレフィン成分は、１種単独でも２種以上を同時に使用してもよい。
エチレンおよび／またはα−オレフィンの中では、エチレンの単独使用が最も好ましい。
一般式（Ｉ）で示される環状オレフィンについて、Ｒ１〜Ｒ１２は、それぞれ同一でも異なっていてもよく、水素原子、ハロゲン原子、及び、炭化水素基からなる群より選ばれるものである。一般式（Ｉ）で示される環状オレフィンの具体例としては、特開２００７−３０２７２２と同様のものを挙げることができる。
また、環状オレフィンは、１種単独でも、また２種以上を組み合わせて使用してもよい。これらの中では、ビシクロ［２．２．１］ヘプタ−２−エン（慣用名：ノルボルネン）を単独使用することが好ましい。 As the cyclic olefin-based resin according to the present invention, a cyclic olefin-based copolymer is particularly preferably used. The cyclic olefin ring-opening polymer or its hydrogenated product may be discolored in a heated environment due to the remaining double bond. In addition, the cyclic olefin copolymer has better affinity and better adhesion than the cyclic olefin ring-opening polymer or its hydrogenated product in vulcanization adhesion with EVA.
Examples of the cyclic olefin copolymer include a copolymer containing ethylene and / or α-olefin and a structural unit derived from the cyclic olefin represented by the following general formula (I).

(In the formula, R1 to R12 may be the same or different, and are selected from the group consisting of a hydrogen atom, a halogen atom, and a hydrocarbon group,
R9 and R10, R11 and R12 may be integrated to form a divalent hydrocarbon group,
R9 or R10 and R11 or R12 may form a ring with each other.
N represents 0 or a positive integer;
When n is 2 or more, R5 to R8 may be the same or different in each repeating unit. )
The α-olefin is not particularly limited, but an α-olefin having 2 to 20 carbon atoms is preferable. For example, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4 -Methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, -Decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene and the like can be mentioned. These α-olefin components may be used alone or in combination of two or more.
Among ethylene and / or α-olefin, the use of ethylene alone is most preferred.
Regarding the cyclic olefin represented by the general formula (I), R1 to R12 may be the same or different, and are selected from the group consisting of a hydrogen atom, a halogen atom, and a hydrocarbon group. Specific examples of the cyclic olefin represented by the general formula (I) include those similar to those described in JP-A-2007-302722.
Moreover, a cyclic olefin may be used individually by 1 type, or may be used in combination of 2 or more type. Among these, it is preferable to use bicyclo [2.2.1] hept-2-ene (common name: norbornene) alone.

  The polymerization catalyst used is not particularly limited, and can be obtained by a known method using a conventionally known catalyst such as a Ziegler-Natta, metathesis, or metallocene catalyst. The cyclic olefin and α-olefin addition copolymer or hydrogenated product thereof preferably used in the present invention is preferably produced using a metallocene catalyst.

  Methods for producing cyclic olefin resins used in the present invention are already known. For example, JP-A-3-45612, JP-A-60-168708, and JP-A-62-252406 disclose methods for producing cyclic olefin addition polymers. JP-A-63-145324, JP-A-63-264626, and JP-A-1-240517 report a ring-opening polymerization of a cyclic olefin and a method for producing a hydrogenated product thereof. According to these manufacturing methods, it can manufacture by selecting conditions suitably.

  For example, in a cyclic olefin copolymer composed of ethylene and norbornene, cyclic olefin copolymers having various glass transition temperatures (Tg) can be synthesized by changing the norbornene content. As the norbornene content is decreased and ethylene is increased, the Tg decreases accordingly.

  A polymer having a glass transition temperature (Tg) of each composition can be obtained by the above-described polymerization, but can be obtained by a commercial grade melt blend. In general, in a system that is compatible with a blend of resins having different glass transition temperatures (Tg), additivity is established depending on the blend ratio. In obtaining the cyclic olefin resin of the present invention, in addition to the above-mentioned method by polymerization, it can be prepared by melt blending of existing grades by an extruder, and the effect of the invention is not changed at all.

<1-3> Other components For the purpose of improving the weather resistance, the anti-PID film of the present invention is an antioxidant for the purpose of improving long-term thermal stability, such as an ultraviolet absorber, a hindered amine stabilizer, and a light-resistant stabilizer. For example, a lubricant may be blended for the purpose of improving the moldability of the film.

<2> Solar cell module The solar cell module of the present invention is provided with the above-described PID countermeasure film for the solar cell of the present invention.

  FIG. 1 is a schematic cross-sectional view showing an example of the solar cell module of the present invention. A solar cell module 100 shown in FIG. 1 includes an existing sealing film 18, an anti-PID film 14 of the present invention, an existing sealing film 18, and a solar cell element 15 in order from a transparent glass plate 11 that is a surface substrate on the light receiving side. The existing sealing film 18 and the back sheet 12 are provided. The back sheet may be a cover glass. In that case, the solar cell module 200 as shown in FIG. That is, the configuration is symmetrical with respect to the solar cell element 15. The configuration of the solar cell module shown in FIGS. 1 and 2 is an example, and the solar cell module of the present invention is not limited to the configuration.

  The solar cell element used in the solar cell module of the present invention is not particularly limited, and silicon-based compounds such as single crystal silicon, polycrystalline silicon, and amorphous silicon, III-V group and II-VI group compounds (gallium-arsenide, Various solar cell elements such as compound semiconductors such as copper-indium-selenium, copper-indium-gallium-selenium, cadmium-tellurium, and the like can be used.

  Further, in the solar cell module of the present invention, as the surface substrate on the sunlight receiving side, when glass is used as the transparent base material, white glass that releases sodium ions may be used, or the glass surface may be potassium ions. Chemically tempered glass substituted with may be used. Metal ions released from the glass are protected by the PID countermeasure film of the present invention, the solar cells are protected, and no PID is generated.

  In addition, the PID countermeasure film of this invention can be used for the solar cell module using an acrylic resin, a polycarbonate, polyester, a fluorine-containing resin etc. as a transparent substrate of a solar cell module.

  The back sheet on the opposite side may be a single layer or multilayer film such as a resin film or a metal film. Examples of the resin film include a fluororesin film, a PET (polyethylene terephthalate) resin film, and a PBT (polybutylene). Terephthalate) resin film and the like, and examples of the metal film include films such as aluminum and stainless steel.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

  As the cyclic olefin resin used in the following examples, TOPAS Advanced Polymers, Inc. TOPAS 8007S-04 (glass transition temperature 78 ° C.) and TOPAS 6013M-07 (glass transition temperature 130 ° C.) are used in a blend ratio. Into the mixed mixture, a trace amount of an ultraviolet light inhibitor and a light-resistant stabilizer were blended to prepare a PID countermeasure film having a required glass transition temperature (Tg) and thickness. Using the obtained PID countermeasure film, the solar cell module 100 having the configuration shown in FIG. 1 was produced by the following method. Since the solar cell module is manufactured by a laminating apparatus, each member is laminated on the hot plate of the laminating apparatus with the top and bottom of FIG. 1 turned upside down.

[Example 1]
100 parts by weight of TOPAS 8007S-04 as a cyclic olefin resin, 0.4 parts by weight of 2-hydroxy-4-n-octoxybenzophenone as an ultraviolet absorber, and bis (2,2,6,6-tetramethyl as a light stabilizer -4-Piperidyl) sebacate 0.2 parts by weight was kneaded at a molten resin temperature of 200 ° C. using a twin screw extruder TEX-30α manufactured by Nippon Steel Works to obtain a cyclic olefin-based resin composition pellet. Next, this pellet was put into a single screw extrusion molding machine equipped with a 300 mm width T-die, and a PID countermeasure film (cyclic olefin type) having a resin temperature of 140 ° C. at the T-die part and a glass transition temperature of 78 ° C. and a thickness of 60 μm. Resin film). Using the obtained PID countermeasure film, a solar cell module was produced by the following method.

  The solar cell module 100 prepared a 450 μm fast cure type (EVA-1) manufactured by Mitsui Chemicals as the sealing film 18 on the cover glass 11. On top of that, a PID countermeasure film (cyclic olefin resin film) 14 prepared in this example was laminated in order, and a sealing film 18 (EVA-1), a solar cell crystal cell, and a sealing film 18 ( EVA-1), a PET backsheet manufactured by Toyo Aluminum Co., Ltd. is laminated as a back material (backsheet) 12. The laminated body was heated using a vacuum laminator (manufactured by Nisshinbo Mechatronics Co., Ltd., product name: PVL1537N), hot plate temperature: 150 ° C., processing time: 22 minutes (breakdown, vacuuming: 5 minutes, press: 2 minutes, pressure holding: 15 minutes), press working was performed. The wiring part to be connected to the terminal box was drawn out from the part that was previously cut on the back surface material, fixed with solder, filled with a silicone potting material until the diode was hidden, and covered. As the potting material, PV-7311 manufactured by Dow-Corning was used. An edge seal was not applied to the glass edge portion, and a gap with the aluminum frame was filled with a gasket using Mitsui Chemicals' TPV: miralastomer material.

[Example 2]
Example 2 is the same as Example 1 except that 100 parts by weight of TOPAS8007S-04 is changed to 90 parts by weight of TOPAS8007S-04 and 10 parts by weight of TOPAS6013M-07 as the cyclic olefin resin of Example 1. A PID countermeasure film having a glass transition temperature of 80 ° C. and a thickness of 75 μm was prepared. Using the obtained PID countermeasure film, a solar cell module was produced in the same manner as in Example 1.

[Example 3]
Example 3 is the same as Example 1 except that 100 parts by weight of TOPAS8007S-04 is changed to 72 parts by weight of TOPAS8007S-04 and 28 parts by weight of TOPAS6013M-07 as the cyclic olefin resin of Example 1. A PID countermeasure film having a glass transition temperature of 90 ° C. and a thickness of 100 μm was prepared. Using the obtained PID countermeasure film, a solar cell module was produced in the same manner as in Example 1.

[Example 4]
Example 4 is the same as Example 1 except that 100 parts by weight of TOPAS8007S-04 is changed to 67 parts by weight of TOPAS8007S-04 and 33 parts by weight of TOPAS6013M-07 as the cyclic olefin resin of Example 1. A PID countermeasure film having a glass transition temperature of 93 ° C. and a thickness of 125 μm was prepared. Using the obtained PID countermeasure film, a solar cell module was produced in the same manner as in Example 1.

[Example 5]
Example 5 is the same as Example 1 except that 100 parts by weight of TOPAS8007S-04 is changed to 72 parts by weight of TOPAS8007S-04 and 28 parts by weight of TOPAS6013M-07 as the cyclic olefin resin of Example 1. A PID countermeasure film having a glass transition temperature of 90 ° C. and a thickness of 75 μm was produced. Using the obtained PID countermeasure film, a solar cell module was produced in the same manner as in Example 1. At this time, the solar cell module was manufactured by arranging the PID countermeasure film only on the string W (cover glass side) where a plurality of solar cells were connected as shown in FIG. Therefore, the PID countermeasure film is not provided between the strings W on the cover glass side.

[Comparative Example 1]
Comparative Example 1 was the same as Example 1 except that 100 parts by weight of TOPAS 8007S-04 as the cyclic olefin-based resin of Example 1, 59 parts by weight of TOPAS 8007S-04, and 41 parts by weight of TOPAS 6013M-07 were changed. A PID countermeasure film having a glass transition temperature of 98 ° C. and a thickness of 200 μm was produced. Using the obtained PID countermeasure film, a solar cell module was produced in the same manner as in Example 1.

[Comparative Example 2]
Comparative Example 2 was the same as Example 1 except that 100 parts by weight of TOPAS 8007S-04 was changed to 100 parts by weight of TOPAS 6013M-07 as the cyclic olefin resin of Example 1, and the glass transition temperature was 142 ° C. A PID countermeasure film having a thickness of 100 μm was prepared. Using the obtained PID countermeasure film, a solar cell module was produced in the same manner as in Example 1.

[Comparative Example 3]
In Comparative Example 3, as the cyclic olefin resin of Example 1, an attempt was made to produce a PID countermeasure film having a TOPAS 8007S-04 glass transition temperature of 78 ° C. and a thickness of 30 μm. The film could not be wound and a PID countermeasure film could not be obtained.

[Comparative Example 4]
Comparative Example 4 was the same as Example 1 except that 100 parts by weight of TOPAS8007S-04 was changed to 100 parts by weight of TOPAS6013M-07 as the cyclic olefin resin of Example 1, and the glass transition temperature was 142 ° C. A PID countermeasure film having a thickness of 250 μm was prepared. Using the obtained PID countermeasure film, a solar cell module was produced in the same manner as in Example 1.

[Comparative Example 5]
The comparative example 5 is the conventional solar cell module 900 which does not use the PID countermeasure film using the cyclic olefin resin of a present Example. The conventional solar cell module shown in FIG. 4 is used in the same manner as in Example 1 and without the PID countermeasure film 14 shown in FIG.

[Formability of PID countermeasure film]
The film moldability of the PID countermeasure films prepared in Example 1 to Example 5 and Comparative Example 1 to Comparative Example 4 is as follows. It was evaluated with an indicator. The evaluation results are shown in Table 1.
<Microcrack>
Evaluation point 3 points: No microcracks.
Evaluation point 2 points: There are microcracks in an area of 20% or less of the total module area.
Evaluation point 1 point: There is a microcrack in an area of 60% or more.
A sheet microcrack refers to the same state as innumerable cracks formed in the glass when the glass is divided with a hammer or the like.
<Number of locations of cocoons>
As for the number of wrinkles, the appearance of a 100 m roll PID countermeasure film was observed. / 皺 is a size that is easily recognized by the naked eye, and has a width of 1 mm or more and a length of 30 mm or more.
Evaluation point 3 points: Smooth and smooth.
Evaluation point 2 points: There is one wrinkle.
Evaluation point 1 point: There are two or more wrinkles.

[Module formability of PID countermeasure film]
The moldability of the solar cell module using the PID countermeasure film prepared in Example 1 to Example 5 and Comparative Example 1 to Comparative Example 4 was observed from the light-receiving surface side of the 48 straight solar cell module. The following indicators were used for evaluation. The evaluation results are shown in Table 1.
<Microcrack>
Evaluation point 3 points: No microcracks.
Evaluation point 2 points: There are microcracks in 5% or less of the total area.
Evaluation point 1 point: 10% or more of the total area has microcracks.
<Number of scars>
The wrinkle mark is a circular wrinkle on the PID countermeasure film and has a radius of 500 μm or more.
Evaluation point 3 points: There is no scar.
Evaluation point 2 points: No more than 5 scars.
Evaluation point 1 point: 6 or more scars.

[PID test]
The PID test was carried out as follows for the solar cell modules produced in Examples 1 to 5 and Comparative Examples 1 to 5.

The output of the solar cell module prepared in advance was measured with a solar simulator. Then, after putting in the chamber of 85 degreeC and 85% humidity and applying the voltage of -1000V for 2500 hours with the PID test apparatus by an Espec company, the solar cell module was taken out and the output was again measured with the solar simulator. The power generation deterioration degree of the solar cell module was calculated by the following formula.
Degree of power generation deterioration (%) = [(original maximum output−maximum output after PID test) / (original maximum output)] × 100

  During the PID test, an aluminum plate was placed on the cover glass of the solar cell module, and leakage current generated between the aluminum plate and the output terminal of the solar cell module was measured. Table 1 shows the measurement results of leakage current 1000 hours after the start of the PID test of each Example and Comparative Example as the PID test result.

  Table 1 shows the results of the PID test of the solar cell modules produced in Examples 1 to 5 and Comparative Examples 1 to 5. As can be seen from Table 1, it can be seen that the solar cell modules of Examples 1 to 5 using the PID countermeasure film of the present invention have no power generation deterioration due to PID. FIG. 3 shows the change to. The horizontal axis in FIG. 3 represents the OID test time, and the vertical axis represents the power generation capacity retention rate (%). The power generation capacity retention rate is a numerical value obtained by subtracting the power generation deterioration degree (%) from 100%. If it is 100%, it indicates that no power generation deterioration has occurred. It can be seen that the output of the solar cell module not using the PID countermeasure film of Comparative Example 5 is zero in a short period of time.

  According to the present invention, since power generation deterioration due to the PID phenomenon can be prevented in a solar cell power plant for at least 20 years in the field, power can be generated as a power plant having the same life as a thermal power plant or a hydropower plant.

100: Solar cell module 200: Solar cell module 11: Cover glass 12: Back material (back sheet)
14: PID countermeasure film (cyclic olefin resin film)
15: Crystalline cell (solar cell)
18: Sealing film (EVA etc.)
900: Conventional solar cell module

Claims (4)

Cyclic olefin resin film having a width of 80 cm or more and a glass transition temperature of 75 ° C. or more and 95 ° C. or less, which is a PID countermeasure film laminated between a solar cell power generation element and a cover glass in a solar cell module so,
The cyclic olefin-based resin is a copolymer composed of ethylene and a cyclic olefin, and the copolymer is only a copolymer having a glass transition temperature of 75 ° C. or higher ,
And the film thickness is 60 micrometers or more and 100 micrometers or less, The PID countermeasure film characterized by the above-mentioned.   The PID countermeasure film according to claim 1, wherein an EVA sealing film is integrated with the PID countermeasure film.   A PID countermeasure solar cell module, wherein the PID countermeasure film according to claim 1 or 2 is provided between a sealing film and a cover glass.   A PID countermeasure solar cell module, wherein the PID countermeasure film according to claim 1 or 2 covers at least 80% or more of the crystal cell area.

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