Fixing tape, solar cell module, and method for applying fixing tape

Abstract

Provided is a fixing tape of which visual discernment from the exterior of a solar cell module is suppressed even when the solar module is manufactured by fixing solar cells or wiring together using the fixing tape for fixing the solar cells or wiring together, and with which yellowing can be suppressed even when the solar cell module is used in an outdoor environment for a long period of time.　A fixing tape 1 is used for fixing a solar cell 2 and / or wiring 3 inside a solar cell module 10. The fixing tape 1 comprises a substrate layer 11 and an adhesive layer 12 laminated on one surface of the substrate layer 11. The substrate layer 11 contains an olefin-based resin. The substrate layer 11 may include a heat-resistant layer 111 and a priming layer 112 that is laminated on the adhesive layer 12 rather than the heat-resistant layer 111.

Description

Fixing Tape, Solar Cell Module, and Method for Attaching Fixing Tape

[0001] The present invention relates to a fixing tape, a solar cell module, and a method for attaching the fixing tape.

[0002] Conventionally, the layer structure of a solar cell module is configured such that a transparent front substrate, a light-receiving surface side sealing material, a plurality of solar cell cells, a non-light-receiving surface side sealing material, and a back surface protection sheet are laminated in this order from the light-receiving surface side.

[0003] Such a solar cell module is manufactured, for example, by stacking a transparent front substrate, a light-receiving surface side sealing material, a plurality of solar cell cells, a non-light-receiving surface side sealing material, and a back surface protection sheet in this order and performing thermocompression bonding using a vacuum laminator or the like. At this time, if the solar cell cells are not fixed to some extent, they will move and shift during the melting of the sealing material, so a fixing tape for fixing the solar cell cells and the wirings connecting them may be used.

[0004] For example, Patent Document 1 describes a technique related to an adhesive tape (fixing tape) characterized by mainly including a resin layer mainly composed of polyethylene terephthalate.

[0005] According to Patent Document 1, it is described that this adhesive tape is excellent in various properties such as weather resistance, heat resistance, electrical insulation, and mechanical strength, and can particularly minimize long-term performance degradation.

[0006] In addition, Patent Document 2 describes a technique related to a sheet for a solar cell module, which includes an ultraviolet absorber, has a resin layer mainly composed of an acrylic resin and an adhesive layer in this order, and has a total light transmittance of 80% or more.

[0007] Patent Document 2 describes that this sheet for a solar cell module is excellent in weather resistance and transparency and can withstand use in a harsh outdoor environment over a long period.

[0008] Japanese Patent Application Laid-Open No. 2011-32451 Japanese Patent Application Laid-Open No. 2017-183485

[0009] The present invention aims to provide a fixing tape that, even when solar cells and wiring are fixed together using fixing tape during the manufacturing of a solar cell module, is not visible from the outside of the solar cell module, and that can suppress yellowing even when the solar cell module is used in an outdoor environment for a long period of time.

[0010] As a result of diligent research, the inventors have found that the above problems can be solved by comprising a base layer and an adhesive layer, wherein the base layer contains an olefin resin, and have completed the present invention. Specifically, the present invention provides the following.

[0011] (1) A fixing tape used to fix solar cells and / or wiring inside a solar cell module, comprising: a base layer; and an adhesive layer laminated on one side of the base layer, wherein the base layer contains an olefin resin.

[0012] (2) The fixing tape according to (1), wherein the base layer comprises a heat-resistant layer and an adhesion layer laminated on the side of the heat-resistant layer that is on the adhesive layer side.

[0013] (3) The fixing tape according to (2), wherein the heat-resistant layer contains a polypropylene resin, and the adhesive layer contains a polyethylene resin and a polypropylene resin.

[0014] (4) A solar cell module comprising: a first sealing layer; solar cells and / or wiring disposed on the first sealing layer; fixing tape according to any one of (1) to (3) for fixing the solar cells and / or wiring; and a second sealing layer disposed so as to cover the solar cells and / or wiring on the first sealing layer fixed by the fixing tape.

[0015] (5) The solar cell module according to (4), wherein the first sealing layer and the second sealing layer contain an olefin resin.

[0016] (6) A method for attaching fixing tape to fix solar cells and / or wiring inside a solar cell module using fixing tape described in any one of (1) to (3), comprising: a cell arrangement step of arranging a plurality of solar cells and a plurality of wiring on a sealing material layer of the solar cell module; and a fixing step of fixing at least one combination of adjacent solar cells, adjacent wiring, and adjacent solar cells and wiring to the sealing material layer with the fixing tape.

[0017] According to the present invention, even when solar cell modules are manufactured by fixing solar cells and wiring together with fixing tape, it is possible to provide a fixing tape that effectively suppresses the visibility of the fixing tape from the exterior of the solar cell module, and that effectively suppresses yellowing even when the solar cell module is used in an outdoor environment for a long period of time.

[0018] This is a schematic cross-sectional view showing the layer structure of a fixing tape according to one embodiment of the present invention. This is a schematic cross-sectional view showing an example of the layer structure of a solar cell module using the fixing tape and solar cells according to one embodiment of the present invention. This is a front view of a solar cell module using the fixing tape and solar cells according to one embodiment of the present invention. This is a front view of a solar cell module using the fixing tape and solar cells according to another embodiment of the present invention. This is a graph showing the total light transmittance (%) of the "fixing tape (Example 1)" according to one embodiment of the present invention.

[0019] The following describes specific embodiments of the present invention in detail. However, the present invention is not limited in any way to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0020] In this specification, notations such as "A to B" mean "A or greater and B or less," and are used as a concept that includes A and B themselves.

[0021] ≪1. Fixing Tape≫ The fixing tape according to this embodiment is a fixing tape used to fix solar cells and / or wiring inside a solar cell module. This fixing tape is used to fix solar cells and / or wiring when manufacturing a solar cell module by heat-pressing each layer, including the solar cells, together, that is, to fix solar cells to each other, to fix wiring to each other, and to fix solar cells to wiring. A solar cell module equipped with the fixing tape is manufactured by heat-pressing the solar cells and / or wiring on the sealing material layer with the fixing tape, using a vacuum laminator or the like.

[0022] Furthermore, the fixing tape according to this embodiment comprises a base layer 11 and an adhesive layer 12 laminated on one side of the base layer 11, wherein the base layer 11 contains an olefin resin.

[0023] By manufacturing solar modules using fixing tape with this configuration to secure solar cells and wiring to each other, the fixing tape can be effectively hidden from view of the solar module. Furthermore, yellowing of the fixing tape can be effectively suppressed even when the solar module is used in an outdoor environment for a long period of time.

[0024] In this specification, the terms "polyolefin resin," etc., are used to include not only "polyolefin resin" but also copolymers that contain, for example, 50% or more (preferably 70% or more, more preferably 80% or more) of the polyolefin main chain, and in which a portion of the main chain is replaced by another main chain different from that of polyolefin. The same applies to "polypropylene resin" and "polyethylene resin" described later.

[0025] Furthermore, the fixing tape according to this embodiment may also have a base layer consisting of one layer. In particular, as shown in Figure 1, the base layer 11 preferably comprises a heat-resistant layer 111 and an adhesion layer 112 laminated on the adhesive layer 12 side of the heat-resistant layer 111. By having such a configuration with a heat-resistant layer 111 and an adhesion layer 112, it is possible to provide high adhesion to the sealing material, thereby suppressing displacement of the solar cells and / or wiring during heat compression bonding.

[0026] The following describes each layer constituting the fixing tape 1, which comprises a heat-resistant layer 111 and an adhesive layer 112 according to one embodiment of the present invention.

[0027] [Heat-resistant layer] The heat-resistant layer 111 provides heat resistance to the fixing tape 1. Because the fixing tape has a heat-resistant layer 111, deformation of the fixing tape can be suppressed when manufacturing solar cell modules by heat-pressing, so that the shifting of solar cells and / or wiring during heat-pressing can be suppressed, and as a result the solar cells and / or wiring can be effectively fixed by the fixing tape.

[0028] The heat-resistant layer can be any layer containing an olefin resin. Among these, it is preferable to include a polypropylene resin as the base resin, and more preferable to include homopolypropylene (homoPP) resin as the base resin. By including a polypropylene resin as the base resin, it becomes possible to effectively impart heat resistance using fixing tape, thereby enabling more effective fixing of solar cells and / or wiring.

[0029] In this specification, "base resin" refers to the resin with the highest content ratio among the resin components of a resin composition containing the base resin. Furthermore, when a mixture of the same type of resin with different densities (for example, multiple polyethylenes with different densities) is used as the base resin, the entire mixture of resins shall be considered the base resin.

[0030] When the heat-resistant layer 111 contains a polypropylene resin as the base resin, the polypropylene resin content is preferably 40% by mass or more of the total heat-resistant layer, more preferably 50% by mass or more, and even more preferably 55% by mass or more.

[0031] Furthermore, when the heat-resistant layer 111 contains a polypropylene resin as the base resin, it may also contain resins other than polypropylene resins. Examples of such resins include polyethylene resins. The "polyethylene resin" may be ordinary polyethylene obtained by polymerizing ethylene, a resin obtained by polymerizing a compound having an ethylenically unsaturated bond such as α-olefin, a resin obtained by copolymerizing multiple different compounds having an ethylenically unsaturated bond, or a modified resin obtained by grafting another chemical species onto these resins.

[0032] Furthermore, if the heat-resistant layer 111 contains a polypropylene resin as a base resin and also contains a polyethylene resin, the polyethylene resin content is preferably 5% by mass or more and 50% by mass or less of the total heat-resistant layer, more preferably 8% by mass or more and 40% by mass or less, and even more preferably 10% by mass or more and 35% by mass or less.

[0033] Furthermore, the heat-resistant layer 111 may contain various additives. Examples of such additives include weathering agents, silane coupling agents, crosslinking agents, ultraviolet absorbers, antioxidants, light stabilizers, heat stabilizers, flame retardants, crosslinking agents, crosslinking aids, and compatibilizers. When the heat-resistant layer 111 contains additives, the amount of additives is preferably 1% by mass or more and 20% by mass or less of the total amount of the heat-resistant layer, more preferably 3% by mass or more and 17% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less.

[0034] The thickness of the heat-resistant layer 111 is not particularly limited, but is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 90 μm or less, and even more preferably 20 μm or more and 80 μm or less. A thickness of 10 μm or more for the heat-resistant layer 111 allows the fixing tape to effectively impart heat resistance. Even if the thickness of the heat-resistant layer 111 exceeds 100 μm, the effect of imparting heat resistance does not increase significantly. For this reason, from the viewpoint of productivity, it is preferable that the thickness of the heat-resistant layer 111 be 100 μm or less.

[0035] [Adhesion Layer] The adhesion layer 112 melts at least a portion of the adhesion layer during heat compression bonding, thereby adhering the solar cell and / or wiring to the sealing material after heat compression bonding and preventing the solar cell and / or wiring from shifting.

[0036] The adhesion layer 112 can be any layer containing an olefin resin. Among these, it is preferable that it contains both a polyethylene resin and a polypropylene resin. The inclusion of both polyethylene and polypropylene resins makes it possible to more effectively suppress the displacement of the solar cells and / or wiring.

[0037] When the adhesion layer 112 contains polyethylene resin and polypropylene resin, the content ratio of polyethylene resin to polypropylene resin is preferably in the range of 50:50 to 95:5 (50 / 50 to 95 / 5 for polyethylene resin / polypropylene resin), more preferably in the range of 60:40 to 92:8 (60 / 40 to 92 / 8 for polyethylene resin / polypropylene resin), and even more preferably in the range of 65:35 to 90:10 (65 / 35 to 90 / 10 for polyethylene resin / polypropylene resin). By including polyethylene resin and polypropylene resin within this range of content ratios, it becomes possible to more effectively suppress misalignment of solar cells and / or wiring.

[0038] The "polyethylene resin" may be ordinary polyethylene obtained by polymerizing ethylene, a resin obtained by polymerizing a compound having an ethylenically unsaturated bond such as α-olefin, a resin obtained by copolymerizing multiple different compounds having an ethylenically unsaturated bond, or a modified resin obtained by grafting another chemical species onto these resins.

[0039] In particular, a silane copolymer (silane-modified resin) obtained by copolymerizing α-olefin and an ethylenically unsaturated silane compound as comonomers can be preferably used as part of the base resin of the encapsulant composition. By using such a resin, it is possible to impart higher adhesion to the encapsulant.

[0040] The content of the ethylenically unsaturated silane compound in a copolymer of α-olefin and an ethylenically unsaturated silane compound (silane-modified resin) is preferably, for example, 0.001% by mass or more and 15% by mass or less, more preferably 0.01% by mass or more and 5% by mass or less, and even more preferably 0.05% by mass or more and 2% by mass or less, relative to the total mass of the silane-modified resin. The lower limit of the content of the ethylenically unsaturated silane compound in a copolymer of α-olefin and an ethylenically unsaturated silane compound (silane-modified resin) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.05% by mass or more, relative to the total mass of the silane-modified resin. The upper limit of the content of the ethylenically unsaturated silane compound in a copolymer of α-olefin and an ethylenically unsaturated silane compound (silane-modified resin) is preferably 15% by mass or less, more preferably 5% by mass or less, and even more preferably 2% by mass or less, relative to the total mass of the silane-modified resin.

[0041] Further, the adhesion layer 112 may contain various additives. Examples of such additives include weathering agents, silane coupling agents, crosslinking agents, ultraviolet absorbers, antioxidants, light stabilizers, heat stabilizers, flame retardants, crosslinking agents, crosslinking aids, compatibilizers, and the like. When the adhesion layer 112 contains an additive, the content of the additive is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 17% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less in the total amount of the adhesion layer.

[0042] The thickness of the adhesion layer 112 is not particularly limited, but is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 90 μm or less, and even more preferably 20 μm or more and 80 μm or less. When the thickness of the adhesion layer 112 is 10 μm or more, adhesion can be effectively imparted by the fixing tape. Even if the thickness of the adhesion layer 112 exceeds 100 μm, the effect of imparting adhesion does not increase significantly. Therefore, from the viewpoint of productivity, the thickness of the adhesion layer 112 is preferably 100 μm or less.

[0043] [Adhesive layer] The adhesive layer 12 suppresses the displacement of the solar cell and / or wiring during thermocompression bonding by fixing the solar cell and / or wiring to the encapsulant before thermocompression bonding.

[0044] The adhesive layer 12 is formed of, for example, a conventionally known adhesive. Examples of the adhesive layer include those composed of structural units derived from methacrylic acid esters and containing an acrylic resin derived from an acrylic acid ester and / or other unsaturated monomers as necessary. By providing an adhesive layer composed of structural units derived from such methacrylic acid esters, it becomes possible to effectively fix the solar cell and / or wiring to the encapsulant before thermocompression bonding. Further, by providing an adhesive layer composed of structural units derived from methacrylic acid esters, it is possible to impart higher adhesion to the encapsulant while imparting peelability to the encapsulant. As a result, it becomes possible to relatively easily peel off the fixing seal without damaging the solar cell and / or wiring, etc., for reattaching the fixing seal.

[0045] Examples of the methacrylic acid ester include alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and pentyl methacrylate. Examples of the acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and pentyl acrylate.

[0046] The adhesive layer 12 may contain various additives. Examples of such additives include weathering agents, silane coupling agents, crosslinking agents, ultraviolet absorbers, antioxidants, light stabilizers, heat stabilizers, flame retardants, crosslinking agents, crosslinking aids, compatibilizers, and the like. When the adhesive layer 12 contains an additive, the content of the additive is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 17% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less in the total amount of the adhesive layer.

[0047] The thickness of the adhesive layer 12 is not particularly limited, but is preferably 1 μm or more and 25 μm or less, more preferably 3 μm or more and 22 μm or less, and even more preferably 5 μm or more and 20 μm or less. When the thickness of the adhesive layer 12 is 1 μm or more, the solar cell and / or wiring can be fixed more effectively. Even if the thickness of the adhesive layer 12 exceeds 25 μm, the effect of fixing the solar cell and / or wiring does not increase significantly. Therefore, from the viewpoint of productivity, the thickness of the adhesive layer 12 is preferably 25 μm or less.

[0048] <Manufacturing method of the fixing tape> The manufacturing method of the fixing tape is not particularly limited. For example, as an example of a method for manufacturing a fixing tape having a structure in which the base material layer includes a heat-resistant layer and an adhesion layer, a method of molding by co-extrusion using a kneading extruder with a composition for forming a heat-resistant layer and a composition for forming an adhesion layer can be mentioned. The lower limit of the molding temperature during molding may be a temperature exceeding the melting point of the sealing material composition.

[0049] The melt molding temperature in the production of the fixing tape is preferably the melting point of the resin having the highest melting point among the resins contained in the composition + 30°C or higher.

[0050] Then, after forming a substrate layer comprising a heat-resistant layer and an adhesion layer, as an example, the surface of the adhesion layer is subjected to corona treatment. While applying corona treatment to the surface of the adhesion layer is not an essential part of the process, it can impart adhesion to the adhesive layer.

[0051] Subsequently, an adhesive is applied to the surface of the substrate layer on the adhesion layer side. This allows for the manufacture of a fixing tape with an adhesive layer. The adhesive used to form the adhesive layer may include one containing an acrylic resin.

[0052] ≪2. Solar Cell Module≫ The solar cell module according to this embodiment is a solar cell module equipped with the fixing tape described above, and specifically comprises a sealing material layer (first sealing material layer), solar cells and / or wiring arranged on the sealing material layer, the fixing tape described above for fixing the solar cells and / or wiring, and a sealing material layer (second sealing material layer) arranged to cover the solar cells and / or wiring on the first sealing material layer fixed by the fixing tape.

[0053] If the solar cell modules are secured to each other using the aforementioned fixing tape, the fixing tape can be effectively concealed from view. Furthermore, even when the solar cell modules are used outdoors for extended periods, the yellowing of the fixing tape can be effectively suppressed.

[0054] Figure 2 shows a schematic cross-sectional view illustrating an example of the layer configuration of the solar cell module 10 according to this embodiment. As shown in Figure 2, the solar cell module 10 according to this embodiment has the following layers stacked in order from the light-receiving surface side of the incident light: a transparent front substrate 5, a front sealing material layer 41, a solar cell 2, a back sealing material layer 42, and a back protective sheet 6.

[0055] In this embodiment, the solar cell 2 is placed on the first sealing layer, which is the front sealing layer 41, and the solar cell 2 is fixed with fixing tape 1. Figure 3 shows a front view of the first sealing layer in which the solar cell 2 and wiring 3 are placed, and at least a portion of the solar cell 2 and wiring 3 are fixed with fixing tape 1.

[0056] In the sealing sheet 4 shown in Figure 3, adjacent solar cells 2 and / or wiring 3 are fixed to each other by fixing tape 1 when viewed from the front. As shown in Figure 3, by fixing at least a portion of the solar cells 2 and / or wiring 3 placed on the sealing material 4 with fixing tape 1 prior to heat sealing, it is possible to suppress the movement and displacement of the solar cells 2 and / or wiring 3 when the sealing material melts. Furthermore, since this fixing tape 1 has a base layer 11 containing an olefin resin, even if the solar cell module is manufactured by fixing the solar cells and wiring to each other with fixing tape, it is possible to effectively suppress the visibility of the fixing tape from the appearance of the solar cell module.

[0057] The fixing tape 1 may be used to fix all of the solar cells 2 and wiring 3 placed on the sealing material 4, but as shown in Figure 3, the fixing tape 1 may be used to fix at least some of the solar cells and / or wiring placed on the sealing material sheet 4.

[0058] Figure 4 shows a modified front view of a solar cell module in which solar cells 2 and wiring 3 arranged on the first sealing layer are fixed with fixing tape 1. In Figure 4, in the front view, diagonally arranged solar cells, that is, adjacent to each other in a diagonal direction, are fixed with fixing tape 1. As shown in Figure 4, by fixing at least a portion of the solar cells 2 and / or wiring 3 arranged on the sealing material 4 with fixing tape 1 prior to heat-sealing, it is possible to suppress the movement and displacement of the solar cells 2 and / or wiring 3 when the sealing material melts. Furthermore, since this fixing tape 1 has a base layer 11 containing an olefin resin, even if the solar cell module is manufactured by fixing the solar cells and wiring to each other with fixing tape, it is possible to effectively suppress the visibility of the fixing tape from the appearance of the solar cell module.

[0059] In this embodiment, the first sealing layer on which the solar cell 2 and wiring 3 are arranged is assumed to be the front sealing layer 41. However, for example, the first sealing layer on which the solar cell 2 and wiring 3 are arranged may be assumed to be the back sealing layer 42.

[0060] The transparent front substrate 5, front sealing layer 41, solar cells 2, back sealing layer 42, and back protective sheet 6 constituting the solar cell module 10 according to this embodiment can be conventionally known. Among these, the front sealing layer 41 and the back sealing layer 42 are preferably formed from a sealing material composition with a polyolefin resin as the base resin, and more preferably from a sealing material composition with a polyethylene resin as the base resin. Since the fixing tape that fixes the solar cells and wiring together has a base layer containing an olefin resin, the adhesion between the fixing tape and the sealing layer can be improved by providing a sealing material layer containing a polyolefin resin.

[0061] The polyolefin resin contained in the sealing layer is preferably a polyethylene resin, and more preferably a polyethylene resin obtained by polymerizing a compound having an ethylenically unsaturated bond. Furthermore, along with the polyethylene resin, a silane copolymer obtained by copolymerizing an α-olefin and an ethylenically unsaturated silane compound as comonomers may also be included.

[0062] ≪3. Method for Attaching Fixing Tape≫ The solar cell module according to this embodiment is a method for attaching fixing tape to fix solar cells and / or wiring using the fixing tape described above. Specifically, it comprises a cell arrangement step of arranging a plurality of solar cells and a plurality of wirings on the sealing material layer of the solar cell module, and a fixing step of fixing at least one combination from among combinations of adjacent solar cells, combinations of adjacent wirings, and combinations of adjacent solar cells and wirings to the sealing material layer with fixing tape.

[0063] This method of applying the fixing tape secures the solar cells and / or wiring, preventing them from moving and shifting when the sealing material melts. Furthermore, even when the solar modules are manufactured by fixing the solar cells and wiring together with the fixing tape, the fixing tape is effectively hidden from view, and yellowing of the fixing tape is suppressed even when the solar modules are used outdoors for extended periods.

[0064] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to these descriptions.

[0065] 1. Manufacturing of Fixing Tape (Example 1) As the fixing tape of Example 1, a fixing tape comprising a heat-resistant layer, an adhesion layer, and an adhesive layer was manufactured. Compositions for the heat-resistant layer and adhesion layer, as shown in Table 1 and Table 2 below, were prepared. Using an extruder and a film molding machine with a 200 mm wide T-die, sheets (base layer thickness 80 μm) comprising a heat-resistant layer with a thickness of 40 μm and an adhesion layer with a thickness of 40 μm were manufactured using each composition at an extrusion temperature of 200°C and a take-up speed of 20 m / min.

[0066]

[0067]

[0068] The sheet, comprising the obtained heat-resistant layer and the adhesive layer, was subjected to corona treatment on the surface of the adhesive layer. An adhesive (containing an acrylic urethane adhesive auxiliary agent (Tacky Fire), a portion of a silane coupling agent (KBM403 manufactured by Shin-Etsu Chemical Co., Ltd.), a portion of HALS (LA-24 manufactured by ADEKA Corporation), and a portion of an AO agent (AO-60G manufactured by ADEKA Corporation)) was applied to this surface to form an adhesive layer with a thickness of 10 μm, thereby producing the fixing tape of Example 1.

[0069] (Example 2) In the fixing tape of Example 1, a sheet was manufactured comprising a 40 μm thick adhesive layer using only LLDPE (KF260T manufactured by Nippon PE Co., Ltd.) as the composition for the adhesive layer, and a 40 μm thick heat-resistant layer similar to that of Example 1. The surface of the sheet was subjected to corona treatment, and the adhesive used in Example 1 was applied to that surface to form a 10 μm thick adhesive layer, thereby manufacturing the fixing tape of Example 2.

[0070] (Example 3) In the fixing tape of Example 1, a sheet was manufactured comprising a 40 μm thick adhesive layer using only homo PP (Prime P Co., Ltd. "S135") as the composition for the adhesive layer, and a 40 μm thick heat-resistant layer similar to that of Example 1. The surface of the sheet was subjected to corona treatment, and the adhesive used in Example 1 was applied to that surface to form a 10 μm thick adhesive layer, thereby manufacturing the fixing tape of Example 3.

[0071] (Comparative Example 1) In the fixing tape of Example 1, a sheet (base layer thickness 36 μm) was made with a single layer (single layer) of polyethylene terephthalate film with a thickness of 36 μm as the base layer, corona treatment was applied to the surface of the sheet, and a UV-resistant adhesive (acrylic adhesive) was applied to that surface to form an adhesive layer with a thickness of 24 μm, thereby manufacturing the fixing tape of Comparative Example 1.

[0072] 2. The visibility of the fixing tape was confirmed when the solar cell modules were manufactured using the fixing tapes of Manufacturing Examples 1 to 3 and Comparative Example 1 of the solar cell module evaluation samples, to which the solar cells and wiring were fixed together. Specifically, the sealing material composition (linear low-density polyethylene resin (LLDPE) with a density of 0.080 g / cm³) was used. ３A composition was prepared containing 13 mol% α-olefin (containing C4 and C6 carbon atoms), 0.25 parts by mass of silane coupling agent (vinyltrimethoxysilane), 0.03 parts by mass of crosslinking agent (organic peroxide ("Luperox TBEC" (manufactured by Arkema Yoshitomi Co., Ltd.))), 0.45 parts by mass of ultraviolet absorber (KEMISORB79), and 0.25 parts by mass of light stabilizer (KEMISTAB62 (HALS))) per 100 parts by mass of "LLDPE". The composition was extruded using an extruder and a film molding machine with a 200 mm wide T-die at an extrusion temperature of 210°C and a take-up speed of 1.1 m / min to form a sealing material sheet with a thickness of 450 μm.

[0073] Then, solar cells and / or wiring were placed on the sealing material sheet, and two solar cells (half cells) and wiring were fixed using the fixing tape of the examples and comparative examples. Subsequently, sealing material layers were laminated so as to cover the solar cells and / or wiring on the sealing material layer fixed with fixing tape, and the layers were laminated in the following order: transparent front substrate (glass substrate) / front sealing material layer / two half cells or half cells and wiring or two wirings / rear sealing material layer / back protective sheet. The chamber was set to a temperature of 150°C, vacuumed, and the upper chamber was released to atmospheric pressure at a pressure of 100 kPa. Vacuum heating lamination (vacuum lamination) was performed under vacuum pressure for 12 minutes, and samples for evaluating solar cell modules were obtained for each of Examples 1 to 3 and Comparative Example 1.

[0074] For Comparative Example 2, the solar cell module evaluation sample was obtained in the same manner as described above, except that the solar cells and / or wiring were placed on a sealing sheet without using fixing tape.

[0075] 3. Evaluation [Visibility] The visibility of the fixing tape was evaluated for the solar cell module evaluation samples of Examples 1 to 3 and Comparative Example 1 obtained by the above method, according to the following evaluation criteria.

[0076] (Evaluation Criteria) ○: The fixing tape could not be visually confirmed from the appearance of the obtained solar cell module. ×: The fixing tape could be visually confirmed from the appearance of the obtained solar cell module.

[0077] [Suppression of displacement] For the solar cell module evaluation samples of Examples 1 to 3 and Comparative Examples 1 and 2 obtained by the above method, displacement of the solar cells and / or wiring was checked. Specifically, the distance traveled from the position of the solar cells and / or wiring before manufacturing the solar cell module evaluation sample to the position of the solar cell module evaluation sample after manufacturing was checked and evaluated according to the following evaluation criteria.

[0078] (Evaluation Criteria) ○: No movement of solar cells was observed at all. △: Some movement of solar cells was observed within the acceptable range, but within the range of "0 < movement distance ≤ 1 mm". ×: Movement of solar cells was observed in a range exceeding the acceptable range (1 mm).

[0079] [Fusion Adhesion] The adhesion between the substrate side of the fixing tape and the sealing material was evaluated for the fixing tapes of Examples 1 to 3 and Comparative Example 1 obtained by the above method. Specifically, the sealing material composition (linear low-density polyethylene resin (LLDPE) with a density of 0.080 g / cm³) was evaluated. ３ A composition was prepared containing 13 mol% α-olefin (containing C4 and C6 carbon atoms), 0.25 parts by mass of silane coupling agent (vinyltrimethoxysilane), 0.03 parts by mass of crosslinking agent (organic peroxide ("Luperox TBEC" (manufactured by Arkema Yoshitomi Co., Ltd.))), 0.45 parts by mass of ultraviolet absorber (KEMISORB79), and 0.25 parts by mass of light stabilizer (KEMISTAB62 (HALS))) per 100 parts by mass of "LLDPE". The composition was then extruded using an extruder and a film molding machine with a 200 mm wide T-die at an extrusion temperature of 210°C and a take-up speed of 1.1 m / min to form a sealing material sheet.

[0080] Then, the layers were stacked in the order of ETFE / sealant sheet / fixing tape / ETFE so that the base layer of the fixing tape was in contact with the sealant sheet. The layers were then heated and laminated at a set temperature of 150°C, vacuumed, and the upper chamber was released to atmospheric pressure at a pressure of 100 kPa. Vacuum heating lamination (vacuum lamination) was performed under vacuum pressure for 12 minutes. Evaluation samples were obtained for each of Examples 1 to 3 and Comparative Example 1, and the adhesion between the base material side of the fixing tape and the sealant was confirmed according to the evaluation criteria below.

[0081] (Evaluation Criteria) ○: Good adhesion between the base material of the fixing tape and the sealant. △: Although within the acceptable range, there were areas where the adhesion between the base material of the fixing tape and the sealant was insufficient. ×: No adhesion at all between the base material of the fixing tape and the sealant.

[0082] [Reworkability] The reworkability of the fixing tapes of Examples 1 to 3 and Comparative Example 1 obtained by the above method was evaluated. Specifically, solar cells and / or wiring were placed on a sealing material sheet, and the solar cells (half cells) and wiring were fixed using the fixing tapes of the Examples and Comparative Examples. After 1 minute, the presence or absence of transfer of the adhesive layer was visually checked when the tape was peeled off, and the reworkability was evaluated according to the evaluation criteria below.

[0083] (Evaluation Criteria) ○: No transfer of the adhesive layer to the solar cells or wiring was observed, and the fixing tape could be removed cleanly. ×: Transfer of the adhesive layer to the solar cells or wiring was observed, or the fixing tape could not be removed cleanly.

[0084] [Transmittance] The transmittance of the fixing tapes of Examples 1 to 3 and Comparative Example 1 obtained by the above method was evaluated. Specifically, the total light transmittance in the range of 400 to 1600 nm was measured for the fixing tapes of Examples 1 to 3 and Comparative Example 1 using a UV-670 manufactured by JASCO Corporation, and the transmittance was evaluated according to the evaluation criteria below. Figure 5 shows the total light transmittance of the fixing tape of Example 1.

[0085] (Evaluation Criteria) ○: The average value of total light transmittance in the range of 400 to 1600 nm was 80% or higher. ×: The average value of total light transmittance in the range of 400 to 1600 nm was less than 80%.

[0086] [Lightfastness] The lightfastness of the solar cell module evaluation samples obtained by the above method for Examples 1 to 3 and Comparative Example 1 was confirmed. Specifically, the encapsulant composition (linear low-density polyethylene resin (LLDPE) density 0.080 g / cm³) was used. ３A composition was prepared containing 13 mol% α-olefin (containing C4 and C6 carbon atoms), 0.25 parts by mass of silane coupling agent (vinyltrimethoxysilane), 0.03 parts by mass of crosslinking agent (organic peroxide ("Luperox TBEC" (manufactured by Arkema Yoshitomi Co., Ltd.))), 0.45 parts by mass of ultraviolet absorber (KEMISORB79), and 0.25 parts by mass of light stabilizer (KEMISTAB62 (HALS))) per 100 parts by mass of "LLDPE". The composition was then extruded using an extruder and a film molding machine with a 200 mm wide T-die at an extrusion temperature of 210°C and a take-up speed of 1.1 m / min to form a sealing material sheet.

[0087] Then, the transparent front substrate (glass substrate) / front sealing layer / fixing tape / rear sealing layer / back protective sheet were laminated in that order so that the base layer of the fixing tape was in contact with the sealing sheet. The substrate was then heated to a set temperature of 150°C, vacuumed, and the upper chamber was released to atmospheric pressure at a pressure of 100 kPa. Vacuum heating lamination (vacuum lamination) was performed under vacuum pressure for 12 minutes to obtain an evaluation sample. For this evaluation sample, visible light in the 300-400 nm range (irradiation intensity 1000 W / m²) was applied to the surface of the transparent front substrate (glass substrate) using a metal halide lamp. ２ The fixing tape in the solar cell module evaluation sample was irradiated with light, and the presence or absence of yellowing was checked after irradiation. Light resistance was then evaluated according to the following evaluation criteria.

[0088] (Evaluation Criteria) ○: No yellowing of the fixing tape was observed. ×: Yellowing of the fixing tape was observed.

[0089] [Processability] The processability (drying properties) of the fixing tapes obtained by the above method in Examples 1 to 3 and Comparative Example 1 was confirmed. Specifically, the fixing tapes after the adhesive was applied were transported to a drying hood with a drying temperature of 55°C, and the transportability within the drying hood by roll-to-roll was confirmed. Lightfastness was then evaluated according to the following evaluation criteria.

[0090] (Evaluation Criteria) ○: The fixing tape could be transported without any problems even inside the drying hood. △: The base material layer curled inside the drying hood, which sometimes affected the transport of the fixing tape inside the drying hood.

[0091]

[0092] As can be seen from the results above, by manufacturing a solar cell module by fixing solar cells and wiring together with a fixing tape having a base layer containing an olefin resin, it is possible to suppress the visibility of the fixing tape from the appearance of the solar cell module and to suppress yellowing of the fixing tape even when the solar cell module is used in an outdoor environment for a long period of time.

[0093] 1 Fixing tape 11 Base material layer 111 Heat-resistant layer 112 Adhesion layer 12 Adhesive layer 10 Solar cell module 2 Solar cell 3 Wiring 4 Sealing material sheet 41 Front sealing material layer 42 Rear sealing material layer 5 Transparent front substrate 6 Back protective sheet

Claims

1. A fixing tape used to secure solar cells and / or wiring inside a solar cell module, comprising: a base layer; and an adhesive layer laminated on one side of the base layer, wherein the base layer contains an olefin resin.

2. The fixing tape according to claim 1, wherein the base layer comprises a heat-resistant layer and an adhesion layer laminated on the side of the heat-resistant layer that is closer to the adhesive layer.

3. The fixing tape according to claim 2, wherein the heat-resistant layer contains a polypropylene resin, and the adhesive layer contains a polyethylene resin and a polypropylene resin.

4. A solar cell module comprising: a first sealing layer; solar cells and / or wiring disposed on the first sealing layer; fixing tape according to any one of claims 1 to 3 for fixing the solar cells and / or wiring; and a second sealing layer disposed so as to cover the solar cells and / or wiring on the first sealing layer fixed by the fixing tape.

5. The solar cell module according to claim 4, wherein the first sealing layer and the second sealing layer contain an olefin resin.

6. A method for attaching fixing tape to fix solar cells and / or wiring inside a solar cell module using fixing tape according to any one of claims 1 to 3, comprising: a cell arrangement step of arranging a plurality of solar cells and a plurality of wirings on a sealing material layer of the solar cell module; and a fixing step of fixing at least one combination of adjacent solar cells, adjacent wirings, and adjacent solar cells and wirings to the sealing material layer with the fixing tape.

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