Easily-disassembled photovoltaic adhesive film

Abstract

The utility model provides an easy-to-disassemble photovoltaic adhesive film, which is clamped between photovoltaic glass and a battery piece in a photovoltaic module and comprises a substrate layer and an easy-to-disassemble layer which are laminated, the easy-to-disassemble layer is in close contact with the photovoltaic glass, and the adhesive force of the easy-to-disassemble layer to test glass is smaller than that of the substrate layer to the test glass. Through the implementation of the technical scheme, the requirements of reliability required in the use process of the photovoltaic module and relatively low peel strength in the recovery treatment process are met at the same time, so that the packaging adhesive film is easy to separate from substrates such as packaging glass, and the photovoltaic module can be disassembled in a more environment-friendly manner.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic module technical field, specifically disclose an easily disassembled photovoltaic glue film. BACKGROUND

[0002] With the global environment deterioration and the increasingly intensified energy crisis, carbon peak and carbon neutral have become the global consensus, and photovoltaic power generation has become one of the important ways for countries to achieve climate goals, and the installed capacity is growing rapidly. In 2021, the global newly installed photovoltaic capacity reached 183GW, with a year-on-year growth of more than 30%. It is estimated that by 2030, this figure will increase to 334GW. As the most mature country in photovoltaic industry development, the cumulative installed capacity of photovoltaic power generation in China has exceeded 200GW, and it is estimated that by 2030, the annual newly installed capacity in China will reach 105-128GW.

[0003] However, the large-scale application of photovoltaic power generation inevitably leads to the recycling problem of abandoned photovoltaic modules. According to the prediction of the International Energy Agency, by 2030, the global photovoltaic module recycling will reach about 8 million tons, and about 1.5 million tons of photovoltaic modules need to be recycled in China, and the problem of waste photovoltaic module treatment is increasingly prominent.

[0004] Photovoltaic glue film is an indispensable part of silicon solar cell panel, and the raw materials of existing commercial photovoltaic glue film are mainly EVA and POE, which are linear polymers with low softening point and will creep at the working temperature of the battery. Therefore, it is usually necessary to add a crosslinking agent to the glue film raw material, and the raw material can be crosslinked to form a three-dimensional network structure when laminated at high temperature, meeting the use requirements of solar modules under various conditions.

[0005] Conventional polyolefin photovoltaic modules use ethylene-alpha olefin copolymer as the main substrate, and add peroxide crosslinking agent and co-crosslinking agent in the substrate system to form sufficient adhesion with glass or battery during lamination process (about 140℃), but the glue film in the module is difficult to separate from the glass panel and the battery piece during recycling process, resulting in low recycling efficiency of glass and silicon battery piece.

[0006] Therefore, it is an urgent problem in the industry to find a photovoltaic glue film that can ensure the reliability of photovoltaic modules during use and be easily disassembled during recycling. INVENTION CONTENTS

[0007] In order to neither affect the reliability of photovoltaic modules nor facilitate the disassembly of photovoltaic modules during recycling, the utility model provides an easily disassembled photovoltaic glue film, which is arranged between the photovoltaic glass and the battery piece in the photovoltaic module, and includes a base layer and an easily disassembled layer arranged in layers, and the easily disassembled layer forms close contact with the photovoltaic glass.

[0008] Further, the adhesion of the easy-to-disassemble layer to the test glass is less than the adhesion of the base layer to the test glass.

[0009] Further, the cross-linking degree of the easy-to-disassemble layer is less than 40%.

[0010] Further, the easy-to-disassemble layer is a single-layer structure, the first surface of the easy-to-disassemble layer is closely attached to the first surface of the base layer, and the second surface of the easy-to-disassemble layer is closely attached to the photovoltaic glass or the cell piece.

[0011] Further, the easy-to-disassemble layer includes a first easy-to-disassemble layer and a second easy-to-disassemble layer, and the first easy-to-disassemble layer, the base layer, and the second easy-to-disassemble layer are sequentially stacked.

[0012] Further, the first surface of the first easy-to-disassemble layer is closely attached to the first surface of the base layer, and the second surface of the first easy-to-disassemble layer is closely attached to the photovoltaic glass; the first surface of the second easy-to-disassemble layer is closely attached to the second surface of the base layer, and the second surface of the second easy-to-disassemble layer is closely attached to the cell piece.

[0013] Further, the base layer is a single-layer structure selected from one of an EVA adhesive film layer, a POE adhesive film layer, a PU adhesive film layer, and a PVB adhesive film layer.

[0014] Further, the base layer is a multi-layer structure, and the multi-layer structure is a combination of EVA adhesive film layers or POE adhesive film layers, and the combination includes one of a transparent EVA adhesive film layer, a white EVA adhesive film layer, a transparent POE adhesive film layer, a white EVA adhesive film layer, a transparent EVA adhesive film layer, a transparent POE adhesive film layer, and a transparent EVA adhesive film layer.

[0015] Further, the thickness ratio of the base layer to the easy-to-disassemble layer is not less than 2.

[0016] Further, the thickness of the base layer ranges from 100 microns to 500 microns.

[0017] Further, the thickness of the easy-to-disassemble layer ranges from 50 microns to 200 microns.

[0018] The present application includes at least one of the following beneficial technical effects:

[0019] 1. The polyolefin with a small cross-linking degree is used as the easy-to-disassemble layer, so that the easy-to-disassemble layer and the cell piece or the glass panel are well bonded.

[0020] 2. During the operation of the photovoltaic module, the polyolefin easy-to-disassemble layer has good water and oxygen blocking effects and good light transmission performance, and does not affect the power generation performance of the photovoltaic module.

[0021] 3. Although the easy-to-remove layer is tightly bonded to the substrate layer, the easy-to-remove layer is made of polyolefin material, which has low polarity. Peroxides in the substrate layer do not easily migrate to the easy-to-remove layer, thus avoiding excessive cross-linking of the easy-to-remove layer during the lamination process.

[0022] 4. The easily removable layer will not flow and cause the solder ribbon to peel off from the battery during high and low temperature processes after irradiation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the easily disassembled adhesive film layer structure in this application.

[0024] 10 - Easy-to-remove adhesive film

[0025] 1 - Easy-to-disassemble layer

[0026] 2—Matrix layer Detailed Implementation

[0027] To make the utility model's objectives, technical solutions, and beneficial effects clearer, the present invention will be described in detail below with reference to specific embodiments. It should be understood that the embodiments described in this specification are merely illustrative and not intended to limit the scope of the present invention.

[0028] For simplicity, this paper only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an undefined range; and any lower limit can be combined with other lower limits to form an undefined range, just as any upper limit can be combined with any other upper limit to form an undefined range. Furthermore, although not explicitly stated, every point or individual value between the endpoints of a range is included within that range. Therefore, each point or individual value can serve as its own lower or upper limit and be combined with any other point or individual value, or with other lower or upper limits, to form an undefined range.

[0029] In this description, it should be noted that, unless otherwise stated, "above" and "below" include the stated number, and "multiple" in "one or more" means two or more.

[0030] The above description of this utility model is not intended to describe every disclosed embodiment or implementation of this utility model. The following description provides more specific examples of exemplary embodiments. Throughout this application, guidance is provided through a series of embodiments that can be used in various combinations. In each embodiment, the examples are listed only as representative groups and should not be construed as exhaustive.

[0031] In some embodiments, the easy-to-disassemble photovoltaic adhesive film comprises a base layer and an easy-to-disassemble layer, the easy-to-disassemble layer is closely attached to one side surface of the base layer, the easy-to-disassemble layer faces the glass panel of the photovoltaic module, and the base layer faces the cell piece.

[0032] In some embodiments, the easy-to-disassemble layer faces the cell piece of the photovoltaic module, and the base layer faces the glass panel.

[0033] In some embodiments, the easy-to-disassemble layer has two layers, and the two easy-to-disassemble layers are respectively closely attached to two side surfaces of the base layer, and the two easy-to-disassemble layers respectively face the glass panel and the cell piece.

[0034] In some embodiments, the base layer substrate is selected from one or more of EVA resin, POE resin, PVB resin, and PU resin.

[0035] In some embodiments, the base layer is a single-layer or multi-layer structure, such as a single-layer or multi-layer EVA, a single-layer or multi-layer POE, or a multi-layer structure of EVA and POE composite.

[0036] In some embodiments, the base layer includes necessary additives, including peroxide crosslinking agent, coupling agent, light stabilizer, ultraviolet absorber, colored filler, and crosslinking aid substrate selected from one of EVA resin, POE resin, PVB resin, and PU resin.

[0037] In some embodiments, the easy-to-disassemble layer uses polyolefin elastomer as the substrate, the polyolefin elastomer is composed of 90-99 parts by weight of a first polyolefin and 1-10 parts by weight of a second polyolefin, and the sum of the parts by weight of the first polyolefin and the second polyolefin is 100 parts.

[0038] In some embodiments, the polyolefin elastomer includes 90 parts by weight of a first polyolefin and 10 parts by weight of a second polyolefin; or 99 parts by weight of a first polyolefin and 1 part by weight of a second polyolefin; or 95 parts by weight of a first polyolefin and 5 parts by weight of a second polyolefin.

[0039] In some embodiments, the first polyolefin is an ethylene-α-olefin copolymer; the ethylene-α-olefin copolymer is copolymerized from ethylene and another monomer selected from α-olefins with carbon chain length C4-C8, such as ethylene-butene copolymer and ethylene-octene copolymer.

[0040] In some embodiments, the second polyolefin is an olefin copolymer containing unsaturated double bonds, and the second polyolefin is one or more of polybutene, polyisoprene, and ethylene propylene diene rubber. The inclusion of the olefin copolymer containing unsaturated double bonds in the composition of the polyolefin base layer improves the processability and film-forming properties of the polyolefin base layer. For example, the ethylene propylene diene rubber is a copolymer of ethylene, propylene, and a third monomer having a non-conjugated diene structure, and contains carbon-carbon double bonds that can participate in polymerization reactions, thereby providing crosslinking active sites for the irradiation crosslinking reaction.

[0041] In some embodiments, the co-crosslinking agent is an acrylate small molecule, and the co-crosslinking agent can provide crosslinking active sites for the irradiation crosslinking reaction. The amount of the co-crosslinking agent added can be adjusted according to actual conditions. In some examples, the polyolefin base layer further contains 0.1-5 parts of the co-crosslinking agent based on 100 parts by weight of the ethylene copolymer elastomer and the olefin copolymer containing unsaturated double bonds.

[0042] Examples of the co-crosslinking agent include one or more of triallyl isocyanurate, triallyl cyanurate, glycidyl (meth)acrylate, methyl (meth)acrylate, trimethylolpropane trimethacrylate, glyceryl tripropylene acrylate, 2-carboxyethyl acrylate, isobornyl (meth)acrylate, diallyl amine, diallyl sulfide, N,N-dimethyl-bisacrylamide, ethylene glycol dimethacrylate, triallyl cyanurate, tetramethylolmethane tetraacrylate, 2-hydroxyethyl methacrylate phosphate, and tripropylene glycol triacrylate.

[0043] In some embodiments, the easy-to-disassemble layer is crosslinked by irradiation, which can be performed using ultraviolet light or an electron beam, and the easy-to-disassemble layer has a certain degree of crosslinking after irradiation.

[0044] In some embodiments, the easy-to-disassemble layer has a crosslinking degree of no more than 40%, and can be 0%, 2%, 5%, 8%, 10%, 12%, 14%, 15%, 18%, 25%, 28%, 30%, 35%, 37%, or 40%.

[0045] In some examples, α-rays, β-rays, γ-rays, X-rays, or neutron rays can be used for irradiation crosslinking. Electron beam irradiation crosslinking is more easily controllable in terms of crosslinking degree and is more environmentally friendly. During irradiation crosslinking, the film structure itself does not have physical contact with the irradiation device, and the shape of the film structure does not change before and after the reaction, but the internal crosslinking reaction has already occurred. As an example, β-rays (i.e., high-energy electron beams) can be used for irradiation crosslinking. The irradiation dose can be selected to be 5-200 KGy, 10-100 KGy, 20-80 KGy, or 50-150 KGy, etc.

[0046] In some embodiments, the easy-to-disassemble layer has a melt index of less than 1 g / 10 min after irradiation. Through extensive experiments, it has been verified that the easy-to-disassemble EVA film with a melt index of less than 1 g / 10 min will not flow and cause the solder ribbon to peel off the cell during the high and low temperature process.

[0047] In some embodiments, the easy-to-disassemble layer has a visible light transmittance of greater than 90%.

[0048] In some embodiments, the easy-to-disassemble layer further comprises 0.1 parts to 0.5 parts of silane or 0.01 parts to 0.5 parts of a light stabilizer.

[0049] Examples

[0050] The following examples more specifically describe the content disclosed in the present utility model, and these examples are only for illustrative purposes, because various modifications and changes within the scope of the content disclosed in the present utility model are obvious to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight, and the reagents and instruments used in the examples are commercially available.

[0051] In the examples, the data were tested for performance according to the following methods:

[0052] Tensile strength was used to characterize the adhesion: GB / T 1040.3-2006 "Determination of tensile properties of plastics - Part 3: test conditions for films and sheets";

[0053] Crosslinking degree: detected by xylene extraction method in 5.5.3 of GB / T 29848-2018 "Ethylene-vinyl acetate copolymer (EVA) film for encapsulating photovoltaic modules";

[0054] Melt index: GB / T 3682-2000 "Determination of the mass and volume flow rate of the melt of thermoplastics";

[0055] Transmittance: GB / T 29848-2013 "Ethylene-vinyl acetate copolymer (EVA) film for encapsulating photovoltaic modules";

[0056] PL%: the initial power and the power after TC200 of the test assembly were tested, the percentage of attenuation was calculated, and the IEC61215 standard was referred to;

[0057] In this example, the easy-to-disassemble photovoltaic adhesive film comprises an EVA base layer, a POE base layer, and a POE easy-to-disassemble layer, and the composition is shown in Table 1:

[0058] Table 1 Composition of the easy-to-disassemble photovoltaic adhesive film base layer

[0059]

[0060] Preparation process of the easy-to-disassemble photovoltaic adhesive film:

[0061] (1) The measured components of the base layer and the easy-to-disassemble layer were respectively added to the feeding ports of two extruders; the extrusion temperature was 80-120°C, the thickness of the base layer and the thickness of the easy-to-disassemble layer were controlled, and then the base layer adhesive film and the easy-to-disassemble layer adhesive film were respectively prepared through embossing, cooling, traction, and winding processes.

[0062] (2) The base layer adhesive film and the easy-to-disassemble layer adhesive film obtained in step (1) were respectively subjected to electron beam irradiation, and the crosslinking degree, light transmittance, and melt index of the adhesive films after irradiation were tested.

[0063] (3) The base layer adhesive film and the easy-to-disassemble layer adhesive film after irradiation were subjected to thermal compounding to obtain the easy-to-disassemble photovoltaic adhesive film.

[0064] Module reliability test of the easy-to-disassemble photovoltaic adhesive film: The easy-to-disassemble photovoltaic adhesive film and the components of the photovoltaic module were laminated under vacuum and at a temperature of 140 degrees to prepare a module, and the module was sequentially composed of glass panel + easy-to-disassemble adhesive film + cell + easy-to-disassemble adhesive film + back panel. After lamination, the crosslinking degree of the base layer was 85%, and the module was subjected to aging test (TC200 after power generation power PL) and adhesive force test of the adhesive film and glass.

[0065] Disassembly performance test: The prepared photovoltaic module was heated at 200 degrees for 30 minutes, and the adhesive force of the easy-to-disassemble photovoltaic adhesive film and the glass was investigated.

[0066] Example 1

[0067] The easy-to-disassemble adhesive film was a double-layer structure of EVA base layer and easy-to-disassemble layer, as shown in Figure 1 , the EVA base layer was a transparent EVA single layer with a thickness of 500 microns, and the easy-to-disassemble layer was a transparent polyolefin single layer with a thickness of 200 microns.

[0068] During the preparation of the module, the easy-to-disassemble adhesive film was sandwiched between the glass panel and the cell, the easy-to-disassemble layer faced the glass panel, and the base layer faced the cell.

[0069] Example 2

[0070] The difference between Example 2 and Example 1 was that the easy-to-disassemble adhesive film was a three-layer structure of easy-to-disassemble layer, base layer, and easy-to-disassemble layer, which were stacked in order, and the thicknesses were 50 microns, 100 microns, and 50 microns, respectively.

[0071] During the preparation of the module, the easy-to-disassemble adhesive film was sandwiched between the glass panel and the cell, and the two easy-to-disassemble layers respectively faced the glass panel and the cell.

[0072] Example 3

[0073] Example 3 differs from Example 1 in that the base layer is a double layer structure of a transparent EVA layer and a transparent POE layer, with the EVA layer having a thickness of 250 microns and the POE layer having a thickness of 150 microns.

[0074] Example 4

[0075] Example 4 differs from Example 1 in that the base layer is a triple layer structure of a transparent EVA layer, a transparent POE layer, and a transparent EVA layer, with the EVA layer having a thickness of 50 microns and the POE layer having a thickness of 100 microns.

[0076] Example 5

[0077] Example 5 differs from Example 1 in that the EVA base layer contains 8 parts of titanium white powder.

[0078] In the process of preparing the assembly, the easy-to-disassemble adhesive film is sandwiched between the glass backboard and the battery piece, with the easy-to-disassemble layer facing the glass backboard and the base layer facing the battery piece.

[0079] Example 6

[0080] Example 6 differs from Example 3 in that the EVA base layer also contains 8 parts of titanium white powder.

[0081] In the process of preparing the assembly, the easy-to-disassemble adhesive film is sandwiched between the glass backboard and the battery piece, with the easy-to-disassemble layer facing the glass backboard and the base layer facing the battery piece.

[0082] Example 7

[0083] Example 7 differs from Example 6 in that the EVA base layer is a double layer structure of a transparent EVA layer and a white EVA layer, with the transparent EVA layer having a thickness of 250 microns and the white EVA layer having a thickness of 150 microns.

[0084] Example 8

[0085] Example 8 differs from Example 1 in that the base layer is a transparent POE layer having a thickness of 400 microns.

[0086] In the process of preparing the assembly, the easy-to-disassemble adhesive film is sandwiched between the glass backboard and the battery piece, with the easy-to-disassemble layer facing the glass backboard and the base layer facing the battery piece.

[0087] Comparative Example 1

[0088] Comparative Example 1 differs from Example 1 in that the assembly is packaged from top to bottom in the order of: glass + base layer + battery + base layer + backboard, heated to above 350 degrees, and the backboard is partially carbonized, which cannot be disassembled.

[0089] Comparative Example 2

[0090] Comparative Example 2 differs from Example 1 in that the assembly is packaged in the order of glass + easy-to-disassemble layer + battery + easy-to-disassemble layer + back plate from top to bottom, heated to 200 degrees, and easily peeled off and disassembled;

[0091]

[0092] The use of traditional adhesive film packaging cannot achieve the disassembly and peeling of the assembly at a temperature of 200°C. The use of only easy-to-disassemble photovoltaic adhesive film packaging results in a serious aging power attenuation. The use of a composite structure of a cross-linked matrix layer and an easy-to-disassemble layer can meet the packaging requirements and achieve the disassembly of the assembly under certain conditions.

Claims

1. A photovoltaic (PV) easy-to-disassemble adhesive film, which is arranged between a PV glass and a PV cell in a PV module, and comprises a base layer and an easy-to-disassemble layer arranged in a stack, characterized in that, The easy-to-disassemble layer is in close contact with the photovoltaic glass.

2. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein, The adhesion of the easy-to-disassemble layer to the test glass is less than the adhesion of the base layer to the test glass.

3. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein, The cross-linking degree of the easy-to-disassemble layer is less than 40%.

4. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein, The easy-to-disassemble layer is a single-layer structure, the first surface of the easy-to-disassemble layer is closely attached to the first surface of the base layer, and the second surface of the easy-to-disassemble layer is closely attached to the photovoltaic glass or the cell piece.

5. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein The easy-to-disassemble layer includes a first easy-to-disassemble layer and a second easy-to-disassemble layer, and the first easy-to-disassemble layer, the base layer, and the second easy-to-disassemble layer are sequentially stacked.

6. The easy-to-disassemble photovoltaic adhesive film according to claim 4, wherein, The first surface of the first easy-to-disassemble layer is closely attached to the first surface of the base layer, and the second surface of the first easy-to-disassemble layer is closely attached to the photovoltaic glass; the first surface of the second easy-to-disassemble layer is closely attached to the second surface of the base layer, and the second surface of the second easy-to-disassemble layer is closely attached to the cell piece.

7. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein The base layer is a single-layer structure selected from one of an EVA adhesive film layer, a POE adhesive film layer, a PU adhesive film layer, and a PVB adhesive film layer.

8. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein, The base layer is a multi-layer structure, and the multi-layer structure is a combination of EVA adhesive film layers or POE adhesive film layers, the combination including one of a transparent EVA adhesive film layer\white EVA adhesive film layer, a transparent POE adhesive film layer\white EVA adhesive film layer, a transparent EVA adhesive film layer\transparent POE adhesive film layer, and a transparent EVA adhesive film layer\transparent POE adhesive film layer\transparent EVA adhesive film layer.

9. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein, The thickness ratio of the base layer to the easy-to-disassemble layer is not less than 2.

10. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein The thickness of the base layer ranges from 100 microns to 500 microns.

11. The easy-to-disassemble photovoltaic adhesive film according to claim 1, wherein The thickness of the easy-to-disassemble layer ranges from 50 microns to 200 microns.

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