JP2008181929A - Solar cell rear surface protective sheet and solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell rear surface protective sheet having a multilayer structure, in which an external surface resin layer as the outermost layer used for a solar cell module is prevented from delamination even if the solar cell module is used outdoors for a long time, and to provide a solar cell module using the same. <P>SOLUTION: The solar cell rear surface protective sheet 10 has a structure in which an adhesive resin layer 12 and an external surface resin layer 14 are sequentially laminated on one surface of a barrier base layer 11, and an adhesive resin layer 13, an adhesive layer 15 and an internal surface resin layer 16 are sequentially laminated on the other surface. The external surface resin layer is formed of a product formed by directly melting and pressing a fluorine-based resin to the adhesive layer and laminating it, and the solar cell module is formed by unitizing the solar cell rear surface protective sheet so that the external surface resin layer surface may be the outermost side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a solar cell back surface protection sheet which is a member constituting a solar cell module, and a solar cell module using the same.

In recent years, solar cells have been put into practical use as a new energy source that is pollution-free and friendly to the global environment, and constitutes the heart of a photovoltaic power generation system that directly converts solar energy into electricity. ing. As the structure, a single solar cell element is not used as it is, and generally several to several tens of solar cell elements are wired in series and in parallel to protect the element over a long period of time. Therefore, various parsing is performed and unitized. The unit built in this package is called a solar cell module. Generally, the surface exposed to sunlight is covered with glass, the gap is filled with a filler made of thermoplastic, and the back side is protected with heat- and weather-resistant plastic materials. The structure is protected by a sheet. Since a solar cell module is used outdoors, sufficient durability and weather resistance are required in its configuration, material structure, and the like. In particular, the protective sheet used on the back surface is required to have a weather resistance and a low water vapor transmission rate. This is because if the filler is peeled off or discolored due to the permeation of moisture or the wiring is corroded, the output of the module itself may be affected. Conventionally, as a back surface protection sheet used in this solar cell module, a sheet having a laminated structure in which an aluminum foil is sandwiched from both sides with a white polyvinyl fluoride film is often used. The heat of the hot press at ˜150 ° C. softens the polyvinyl fluoride film, the protrusions of the solar cell element electrode part penetrate the filler layer, and further penetrate the polyvinyl fluoride film on the inner surface constituting the back protection sheet By contacting the aluminum foil in the back surface protective sheet, there has been a problem that the solar cell element and the aluminum foil are short-circuited to adversely affect the battery performance. In order to improve these, a back sheet for a solar cell module having a structure in which a plurality of deposited films each having an aluminum deposited layer laminated on both surfaces of a base film is laminated via an adhesive layer has been proposed (for example, a patent) Reference 1).
JP 2005-322687 A

  However, in the proposed back sheet, since the adhesive layer used is entirely made of a polyurethane adhesive, the adhesive is easily hydrolyzed during use and delamination is likely to occur for over 10 years. There were problems such as inability to withstand long-term use.

  An object of the present invention is a back surface protection sheet for solar cells having a multilayer structure, and a back surface protection sheet for solar cells that does not undergo delamination even when the outer surface outer resin layer when used in a solar cell module is used outdoors for a long time, and It is providing the solar cell module using the back surface protection sheet for solar cells.

  In the invention according to claim 1 of the present invention, an adhesive resin layer and an outer resin layer are sequentially laminated on one surface of a barrier base material layer, and an adhesive resin layer, an adhesive layer, and an inner resin layer are laminated on the other surface. In the solar cell back surface protective sheet, the back surface protective sheet for solar cells, wherein the outer surface resin layer is formed by melting and extruding a fluorine-based resin directly on the adhesive resin layer, and laminating it. is there.

  The invention according to claim 2 of the present invention comprises the solar cell back surface protection sheet according to claim 1 and unitized so that the outer resin layer surface is on the outermost side. It is a battery module.

  Thus, according to the first aspect of the present invention, in the back protective sheet for a solar cell having the adhesive resin layer and the outer resin layer on one surface of the barrier base material layer, the outer resin layer is made of a fluororesin. Since it is made of melt-extruded and laminated directly on the adhesive resin layer without an adhesive layer, it has an adhesive layer that is easily hydrolyzed and deteriorated between the outer resin layer and the adhesive resin layer. Therefore, even if it is used outdoors for a long period of time, the outer surface resin layer has a characteristic that it is not delaminated.

  The back surface protective sheet for solar cell of the present invention is formed by sequentially laminating an adhesive resin layer and an outer surface resin layer on one surface of a barrier base material layer, and an adhesive resin layer, an adhesive layer, and an inner surface resin layer on the other surface. In the back protective sheet for solar cells, in which the outer surface resin layer is made by laminating and extruding the fluororesin directly onto the adhesive resin layer and laminating, the water from the outer surface resin layer side There is little deterioration resulting from the delamination of the outer surface resin layer. In addition, the solar cell module in which the back surface protection sheet for solar cells is unitized by using the outer resin layer surface as the outermost side can function as a solar cell even when used for a long time under harsh environmental conditions. Can be held for a long time.

  The back surface protection sheet for solar cells of this invention is demonstrated below. FIG. 1 is a side cross-sectional view showing an embodiment of a back surface protection sheet for solar cells of the present invention. A back surface protection sheet for solar cells (10) has an inner surface resin layer (16) and an adhesive layer in order in the thickness direction. (15), an adhesive resin layer (13), a barrier substrate layer (11), an adhesive resin layer (12), and an outer resin layer (14) are laminated.

  The barrier substrate layer (11) is a barrier laminate film in which a vapor-deposited thin film layer having a thickness of 10 to 300 nm made of aluminum oxide or silicon oxide is laminated on at least one surface of a polyester film having a thickness of 5 to 50 μm. An ethylene / vinyl alcohol copolymer film of 10 to 50 μm is used.

The adhesive resin layer (12, 13) is formed by using a known gravure using a coating agent mainly composed of an adhesive resin having weather resistance, for example, a polyurethane resin, a polyester resin, an acrylic resin, or a polycarbonate resin. It is formed by a coating method. A coating amount of 0.5 to 10 g / m ² (dry state) is preferable.

  The outer surface resin layer (14) is laminated by melt extrusion of the fluororesin directly on the adhesive resin layer (12) using a melt extrusion laminator or the like. Examples of the fluorine-based resin include ethylene / tetrafluoroethylene copolymer (ETFE) resin, tetrafluoroethylene (TFE) / hexafluoropropylene (HFP) / vinylidene fluoride (VDF) terpolymer resin, and polyfluoride resin. Vinyl fluoride (PVF) resin, polyvinylidene fluoride (PVDF) resin, polychlorotrifluoroethylene (PCTFE) resin, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin and the like can be used. All of the resins have excellent insulating properties, chemical resistance, mechanical strength and weather resistance of 10 years or more. Particularly, ETFE resin and terpolymerization resistant resin have a low melting point of 120 to 270 ° C. It has the same processability as a general-purpose thermoplastic resin. The thickness is preferably 25 to 50 μm.

The said adhesive layer (15) consists of a general purpose polyurethane adhesive, and the application quantity is 5-5.
10 g / m ² (dry state).

  For the inner surface resin layer (16), a weather-resistant polyester resin, a weather-resistant polyester resin film, a fluorine resin, a fluorine resin film, or the like is used. In the case of resin, lamination is performed by a melt extrusion method, and in the case of a film, lamination is performed by a known dry lamination method. The thickness is 25 to 250 μm.

  FIG. 2 is a cross-sectional explanatory view showing one embodiment of the solar cell module of the present invention, in which the solar cell module (100) has the back surface protection sheet (10) for solar cells, and the outer surface resin layer (14) surface is on the outermost side. The upper transparent material (101), filler (102), solar cell element (103), wiring (104), solar cell back surface protection sheet (10), sealing material ( 105) and a frame body (106), which has good moisture resistance and can withstand long-term use.

  As the upper transparent material (101), glass, acrylic resin, polycarbonate resin or the like is used, and as the filler (102), polyvinyl butyral resin, silicone resin, vinyl chloride resin, polyurethane resin, ethylene / vinyl acetate are used. Polymer resin or the like is used, butyl rubber or the like is used as the sealing material (105), and an aluminum frame material is generally used for the frame (106).

  An example of the method for producing the solar cell module of the present invention will be described below. A solar cell element (103) connected in advance with a wire is sandwiched between two filler sheets made of ethylene / vinyl acetate copolymer resin having a predetermined thickness. After being sandwiched between, the upper transparent material (101) made of a tempered glass plate is placed on one filler sheet, and the back protective sheet for solar cells is placed on the opposite filler sheet, and then at 40 ° C. for 5 minutes. Pre-heated and further hot pressed at 150 ° C. for about 30 minutes under reduced pressure from both sides to fuse and integrate the back protection sheet for solar cells, sealed the end with butyl rubber, and an aluminum frame (106) The solar cell module is manufactured by fixing with.

  Although the back surface protection sheet for solar cells of this invention is demonstrated according to a specific Example below, this invention is not limited to these Examples.

As the barrier substrate layer (11), a barrier laminate film in which a vapor-deposited thin film layer of silicon oxide having a thickness of 50 nm is laminated on one side of a biaxially stretched polyester film having a thickness of 12 μm is used, and both surfaces of the barrier laminate film are used. In addition, an adhesive resin layer (12, 13) made of an acrylic resin film having a thickness of 5 μm is laminated using a coating agent mainly composed of an acrylic resin, and on one adhesive resin layer (12), Tetrafluoroethylene (TFE) / hexafluoropropylene (HFP) / vinylidene fluoride (VDF) terpolymer resin (Sumitomo 3M Co., Ltd., trade name: Dyneon THV X610G) is used as the outer resin layer (14). laminating a melt extrusion to a thickness of 50 [mu] m, it from the other adhesive resin layer (13) polyurethane adhesive having a dry coating amount of 5 g / m ² on Through the adhesive layer (15), a 50 μm-thick polyvinyl fluoride film (DuPont Co., Ltd .: Tedlar film) is laminated as the inner resin layer (16), and the back protective sheet for solar cells of the present invention is used. Created.

  Examples for comparison of the present invention will be described below.

As a barrier base material layer, a barrier laminate film in which a vapor-deposited thin film layer of silicon oxide with a thickness of 50 nm is laminated on one side of a biaxially stretched polyester film with a thickness of 12 μm is used as a material for the inner surface resin layer and the outer surface resin layer. Using a polyvinyl fluoride film (DuPont Co., Ltd .: Tedlar film) with a thickness of 50 μm, a Tedlar film (50 μm) / polyurethane adhesive (coating amount 5 g / m ² , dry state) / barrier laminate A back protective sheet for a solar cell for comparison with a laminated structure of film (12 μm) / polyurethane adhesive (coating amount 5 g / m ² , dry state) / Tedlar film (50 μm) was prepared.

<Evaluation>
The back surface protective sheet for solar cells of Example 1 of the present invention and the back surface protective sheet for solar cells for comparison of Example 2 were stored under conditions of 85 ° C. and 85% RH, and between the outer surface resin layer and the barrier laminate film. The laminate strength was measured and evaluated before storage, after storage for 500 hours, after storage for 1000 hours, and after storage for 3000 hours. The results are shown in Table 1.

表１に示すように、実施例１の本発明の太陽電池用裏面保護シートは、外面樹脂層とバリア性積層フィルム間のラミネート強度が８５℃、８５％ＲＨ条件下で３０００時間保存後も劣化が少なく、実施例２の比較用の太陽電池用裏面保護シートは、外面樹脂層とバリア性積層フィルム間のラミネート強度が８５℃、８５％ＲＨ条件下で３０００時間保存後、劣化が非常に大であった。

As shown in Table 1, the back protective sheet for solar cells of Example 1 of the present invention was deteriorated even after storage for 3000 hours under the condition that the laminate strength between the outer resin layer and the barrier laminate film was 85 ° C. and 85% RH. The solar cell back surface protective sheet for comparison in Example 2 has a very large deterioration after being stored for 3000 hours under conditions of 85 ° C. and 85% RH at a laminate strength between the outer surface resin layer and the barrier laminate film. Met.

It is a sectional side view which shows one Embodiment of the back surface protection sheet for solar cells of this invention. It is a section explanatory view showing one embodiment of the solar cell module of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Back surface protection sheet 11 for solar cells ... Barrier base material layers 12, 13 ... Adhesive resin layer 14 ... Outer surface resin layer 15 ... Adhesive layer 16 ... Inner surface resin layer 100 ... Solar cell module 101 ... Upper transparent material 102 ... Filler 103 ... Solar cell element 104 ... Wiring 105 ... Sealing material 106 ... Frame

Claims (2)

  Back surface protection for solar cells, in which an adhesive resin layer and an outer surface resin layer are sequentially laminated on one surface of a barrier base material layer, and an adhesive resin layer, an adhesive layer, and an inner surface resin layer are sequentially laminated on the other surface The back surface protective sheet for solar cells, wherein the outer surface resin layer is formed by laminating and laminating a fluorine-based resin directly on the adhesive resin layer.   A solar cell module comprising the solar cell back surface protective sheet according to claim 1 and unitized so that the outer resin layer surface is on the outermost side.

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