A photovoltaic high-bonding gap reflective film and its preparation method and application, photovoltaic module

Abstract

The present invention provides a high-adhesion gap reflective film for photovoltaics, a preparation method and application thereof, and a photovoltaic module, and relates to the field of photovoltaic technology. The high-adhesion gap reflective film for photovoltaics described in the present invention comprises a substrate layer, an EVA layer and a microstructure coating, and the EVA layer and the microstructure coating are respectively located on both sides of the substrate layer; the raw materials for preparing the EVA layer include, by weight: 40 to 60 parts of high-melting-point EVA resin, 40 to 60 parts of low-melting-point EVA resin, 0.2 to 0.5 parts of cross-linking agent, 0.1 to 0.4 parts of auxiliary cross-linking agent, 0.05 to 0.4 parts of silane coupling agent, 1 to 8 parts of ultraviolet absorber and 0.1 to 2 parts of antioxidant; wherein the melting point of the high-melting-point EVA resin is 60 to 80°C, and the melting point of the low-melting-point EVA resin is 40 to 50°C. The high-adhesion gap reflective film for photovoltaics provided by the present invention has good pre-lamination peeling force with glass, and the proportion of bubbles after lamination is low.

Description

Technical Field

[0001] The invention relates to the field of photovoltaic technology, and in particular to a photovoltaic high-bonding gap reflective film, a preparation method and application thereof, and a photovoltaic module. Background Art

[0002] The existing photovoltaic modules include front glass, film, cell, film and back glass. There is a gap of 1 to 4 mm between the strings and cells. The sunlight incident on this gap is difficult to be directly absorbed or utilized. In order to improve the utilization of this part of sunlight, the output power of photovoltaic modules can be increased.

[0003] At present, the methods used are: 1. Use a grid back glass on the back panel to reflect sunlight at the gaps, but the reflection of the grid back panel is diffuse reflection, the reflectivity of sunlight is low, and the output power of the component is limited; the second method is to stick a reflective film on the back glass, opposite to the gaps between the cells. The surface of the reflective film is an aluminum-plated layer with a microstructure, which has a high reflectivity to sunlight and can significantly improve the output power of the photovoltaic module.

[0004] The front of the gap reflective film is an aluminum-plated layer with a microstructure, and the back is an EVA layer. It is preheated by a film laminating machine and attached to the back glass, and then assembled into a laminate for lamination. In actual use, the pre-lamination peeling force between the EVA layer and the glass is low, and the film tape is easy to fall off during the flipping and laminating process. In addition, EVA is prone to end bubbles after lamination, which affects both the appearance and the performance after aging.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a photovoltaic high-bonding gap reflective film, a preparation method and application thereof, and a photovoltaic module. The present invention solves the problem that the gap reflective film is easy to fall off after pre-lamination and bubbles are formed after lamination. The photovoltaic high-bonding gap reflective film has good pre-lamination bonding with the back glass and no end bubbles are formed after lamination.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0008] In a first aspect, the present invention provides a photovoltaic high-adhesion gap reflective film, the photovoltaic high-adhesion gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0009] The raw materials for preparing the EVA layer include, by weight: 40-60 parts of high-melting-point EVA resin and 40-60 parts of low-melting-point EVA resin; wherein the melting point of the high-melting-point EVA resin is 60-80°C, and the melting point of the low-melting-point EVA resin is 40-50°C.

[0010] Preferably, the raw materials for preparing the EVA layer include, by weight: 40-60 parts of high melting point EVA resin, 40-60 parts of low melting point EVA resin, 0.2-0.5 parts of cross-linking agent, 0.1-0.4 parts of auxiliary cross-linking agent, 0.05-0.4 parts of silane coupling agent, 1-8 parts of ultraviolet absorber and 0.1-2 parts of antioxidant.

[0011] Preferably, the raw materials for preparing the EVA layer include, by weight: 40 to 55 parts of high melting point EVA resin, 45 to 60 parts of low melting point EVA resin, 0.23 to 0.48 parts of cross-linking agent, 0.12 to 0.35 parts of auxiliary cross-linking agent, 0.08 to 0.36 parts of silane coupling agent, 2 to 7.5 parts of ultraviolet absorber and 0.3 to 1.5 parts of antioxidant.

[0012] Preferably, the raw materials for preparing the EVA layer include, by weight: 45-55 parts of high melting point EVA resin, 50-55 parts of low melting point EVA resin, 0.25-0.45 parts of cross-linking agent, 0.15-0.32 parts of auxiliary cross-linking agent, 0.1-0.3 parts of silane coupling agent, 4-7 parts of ultraviolet absorber and 0.5-1.2 parts of antioxidant.

[0013] Preferably, the VA content in the high melting point EVA resin is 26-30%, preferably 28%.

[0014] Preferably, the VA content in the low melting point EVA resin is 26-30%, preferably 28%.

[0015] Preferably, the crosslinking agent is selected from any one of tert-butyl peroxycarbonate-2-ethylhexyl ester, di-tert-butyl peroxide or 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, or a combination of at least two thereof.

[0016] Preferably, the auxiliary crosslinking agent is selected from any one of tripropylene trimerisocyanate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, trimethylolpropane trimethacrylate, triallyl cyanurate or ditrimethylolpropane tetraacrylate, or a combination of at least two thereof.

[0017] Preferably, the silane coupling agent is selected from any one of glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane or vinyltri(2-methoxyethoxy)silane, or a combination of at least two thereof.

[0018] Preferably, the UV absorber is selected from any one of salicylate UV stabilizers, benzophenone UV stabilizers, benzotriazole UV stabilizers, hindered amine UV stabilizers, substituted acrylonitrile UV stabilizers or triazine UV stabilizers, or a combination of at least two thereof.

[0019] Preferably, the antioxidant is selected from any one of hindered phenol antioxidants, hindered amine antioxidants, phosphite antioxidants or thioester antioxidants, or a combination of at least two thereof.

[0020] Preferably, the thickness of the EVA layer is 60-90 μm.

[0021] Preferably, the substrate layer is a PET layer.

[0022] Preferably, the substrate layer has a thickness of 20 to 40 μm.

[0023] Preferably, the material of the microstructure coating is selected from any one of aluminum, nickel or silver or a combination of at least two thereof, preferably aluminum.

[0024] Preferably, the microstructure coating is a micro triangular pyramid structure having a continuous strip shape.

[0025] Preferably, the angle between the line formed by the apex angles of the micro triangular pyramid and the MD direction is 30-60°, preferably 45°.

[0026] Preferably, the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 116-120°.

[0027] Preferably, the height of the micro triangular pyramid is 7-8 μm.

[0028] In a second aspect, the present invention provides a method for preparing the photovoltaic high-adhesion gap reflective film as described in the first aspect, the preparation method comprising:

[0029] The raw materials for preparing the EVA layer are mixed, fed into a screw, and extruded through the die head of the screw to be coated on the other side of the substrate layer with the microstructure coating to obtain the photovoltaic high-bonding gap reflective film.

[0030] Preferably, the temperature of the screw is 90-100°C.

[0031] Preferably, the temperature of the die head of the screw is 90-100°C.

[0032] In a third aspect, the present invention provides a use of the photovoltaic high-adhesion gap reflective film as described in the first aspect in the preparation of photovoltaic modules.

[0033] In a fourth aspect, the present invention provides a photovoltaic module, which includes, from top to bottom, a photovoltaic front glass layer, a front packaging film layer, a photovoltaic cell layer, a rear packaging film layer, and a photovoltaic back glass layer with a gap reflective film stacked in sequence; wherein the gap reflective film includes the high-adhesion gap reflective film for photovoltaics as described in the first aspect.

[0034] Preferably, the photovoltaic cell layer includes at least two photovoltaic module cell sheets.

[0035] Preferably, the EVA layer of the photovoltaic high-bonding gap reflective film is bonded to the photovoltaic back glass layer; and corresponds to and fully covers the gaps between the photovoltaic module cells of the photovoltaic cell layer.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The EVA layer provided by the present invention contains a resin with a low melting point and a long melting range. It can be quickly softened after being heated by hot air from a film laminating machine. The pre-lamination bonding strength between the EVA layer and the glass is good. When the glass with the film tape is turned over and laminated, there will be no film peeling problem.

[0038] (2) The EVA layer provided by the present invention has a low degree of crosslinking. During the lamination process, the glass end is greatly deformed by heat, and the bubbles in the end film are not easy to be discharged. The EVA layer with a low degree of crosslinking has a slow crosslinking speed, which is more conducive to the discharge of bubbles from the end, thereby reducing the phenomenon of bubbles. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 This is a schematic diagram of the structure of the high-adhesion gap reflective film for photovoltaic use according to the present invention.

[0041] Among them, 1 is the substrate layer, 2 is the EVA layer, and 3 is the microstructure coating layer.

[0042] Figure 2 It is a schematic diagram of the structure of the photovoltaic module described in the present invention.

[0043] Among them, 10 is a photovoltaic front glass layer, 20 is a front packaging film layer, 30 is a photovoltaic cell layer, 40 is a rear packaging film layer, and 50 is a photovoltaic back glass layer with a gap reflective film. DETAILED DESCRIPTION

[0044] Unless otherwise defined herein, scientific and technological terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0045] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0046] The embodiments of the present invention will be described in detail below in conjunction with the embodiments and examples, but it will be appreciated by those skilled in the art that the following embodiments and examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified, proceed according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0047] In a first aspect, the present invention provides a photovoltaic high-bonding gap reflective film, such as Figure 1 As shown, the photovoltaic high-bonding gap reflective film comprises a substrate layer 1, an EVA layer 2 and a microstructure coating layer 3, and the EVA layer 2 and the microstructure coating layer 3 are respectively located on both sides of the substrate layer 1;

[0048] The raw materials for preparing the EVA layer include, by weight: 40-60 parts of high-melting-point EVA resin and 40-60 parts of low-melting-point EVA resin; wherein the melting point of the high-melting-point EVA resin is 60-80°C, and the melting point of the low-melting-point EVA resin is 40-50°C.

[0049] In the present invention, an EVA layer is arranged on the back of the substrate layer for bonding with the back glass. The EVA layer contains the high-melting-point EVA resin and the low-melting-point EVA resin of the above-mentioned specific proportion and specific melting point, which well solves the problem that the gap reflective film is easy to fall off after pre-lamination and bubbles after lamination. Among them, the low-melting-point resin with a melting point of 40 to 50°C is added, which has a long melting range and can be quickly softened after being heated by hot air from the film laminating machine. The pre-lamination bonding force between the glass is good, and the glass with the film tape attached will not have poor film release when it is turned over and laminated. The high-melting-point EVA resin with a melting point of 60 to 80°C is added to provide melt strength for the EVA layer.

[0050] As an optional embodiment, the content of the high melting point EVA resin is 40 to 60 parts, for example, it can be 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, etc., preferably 40 to 55 parts, and more preferably 45 to 50 parts.

[0051] As an optional embodiment, the content of the low melting point EVA resin is 40 to 60 parts, for example, it can be 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, etc., preferably 45 to 60 parts, and more preferably 50 to 55 parts.

[0052] As an optional embodiment, the total content of the high melting point EVA resin and the low melting point EVA resin is 95 to 105 parts, for example, it can be 95 parts, 96 parts, 97 parts, 98 parts, 99 parts, 100 parts, 101 parts, 102 parts, 103 parts, 104 parts, 105 parts, etc., preferably 98 to 102 parts, and more preferably 100 parts.

[0053] As an optional embodiment, the melting point of the high melting point EVA resin is 60-80°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, etc.

[0054] As an optional embodiment, the melting point of the low-melting-point EVA resin is 40-50°C, for example, it can be 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, etc.

[0055] As an optional embodiment, the raw materials for preparing the EVA layer include, by weight: 40 to 60 parts of high melting point EVA resin, 40 to 60 parts of low melting point EVA resin, 0.2 to 0.5 parts of cross-linking agent, 0.1 to 0.4 parts of auxiliary cross-linking agent, 0.05 to 0.4 parts of silane coupling agent, 1 to 8 parts of ultraviolet absorber and 0.1 to 2 parts of antioxidant.

[0056] As an optional embodiment, the content of the cross-linking agent is 0.2 to 0.5 parts, for example, it can be 0.2 parts, 0.22 parts, 0.24 parts, 0.25 parts, 0.26 parts, 0.28 parts, 0.3 parts, 0.32 parts, 0.34 parts, 0.35 parts, 0.36 parts, 0.38 parts, 0.4 parts, 0.42 parts, 0.44 parts, 0.45 parts, 0.46 parts, 0.48 parts, 0.5 parts, etc.

[0057] As an optional embodiment, the content of the auxiliary cross-linking agent is 0.1 to 0.4 parts, for example, it can be 0.1 parts, 0.12 parts, 0.14 parts, 0.15 parts, 0.16 parts, 0.18 parts, 0.2 parts, 0.2 parts, 0.22 parts, 0.24 parts, 0.25 parts, 0.26 parts, 0.28 parts, 0.3 parts, 0.32 parts, 0.34 parts, 0.35 parts, 0.36 parts, 0.38 parts, 0.4 parts, etc.

[0058] As an optional embodiment, the content of the silane coupling agent is 0.05 to 0.4 parts, for example, it can be 0.05 parts, 0.06 parts, 0.08 parts, 0.1 parts, 0.12 parts, 0.14 parts, 0.15 parts, 0.16 parts, 0.18 parts, 0.2 parts, 0.2 parts, 0.22 parts, 0.24 parts, 0.25 parts, 0.26 parts, 0.28 parts, 0.3 parts, 0.32 parts, 0.34 parts, 0.35 parts, 0.36 parts, 0.38 parts, 0.4 parts, etc.

[0059] As an optional embodiment, the content of the ultraviolet absorber is 1 to 8 parts, for example, it can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, etc.

[0060] As an optional embodiment, the content of the antioxidant is 0.1 to 2 parts, for example, it can be 0.1 parts, 0.12 parts, 0.14 parts, 0.15 parts, 0.16 parts, 0.18 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1 parts, 1.2 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.8 parts, 2 parts, etc.

[0061] As an optional embodiment, the raw materials for preparing the EVA layer include, by weight: 40 to 55 parts of high melting point EVA resin, 45 to 60 parts of low melting point EVA resin, 0.23 to 0.48 parts of cross-linking agent, 0.12 to 0.35 parts of auxiliary cross-linking agent, 0.08 to 0.36 parts of silane coupling agent, 2 to 7.5 parts of ultraviolet absorber and 0.3 to 1.5 parts of antioxidant.

[0062] As an optional embodiment, the raw materials for preparing the EVA layer include, by weight: 45 to 55 parts of high melting point EVA resin, 50 to 55 parts of low melting point EVA resin, 0.25 to 0.45 parts of cross-linking agent, 0.15 to 0.32 parts of auxiliary cross-linking agent, 0.1 to 0.3 parts of silane coupling agent, 4 to 7 parts of ultraviolet absorber and 0.5 to 1.2 parts of antioxidant.

[0063] As an optional embodiment, the VA content in the high melting point EVA resin is 26-30%, for example, it can be 26%, 26.5%, 27%, 27.5%, 28%, 28.5%, 29%, 29.5%, 30%, etc., preferably 28%.

[0064] As an optional embodiment, the VA content in the low melting point EVA resin is 26-30%, for example, it can be 26%, 26.5%, 27%, 27.5%, 28%, 28.5%, 29%, 29.5%, 30%, etc., preferably 28%.

[0065] As an optional embodiment, the cross-linking agent is selected from any one of tert-butyl peroxycarbonate-2-ethylhexyl ester, di-tert-butyl peroxide or 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, or a combination of at least two thereof.

[0066] As an optional embodiment, the auxiliary crosslinking agent is selected from any one of tripropylene trimer isocyanate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, trimethylolpropane trimethacrylate, triallyl cyanurate or ditrimethylolpropane tetraacrylate, or a combination of at least two thereof.

[0067] As an optional embodiment, the silane coupling agent is selected from any one or a combination of at least two of glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane or vinyltri(2-methoxyethoxy)silane.

[0068] As an optional embodiment, the UV absorber is selected from any one of salicylate UV stabilizers, benzophenone UV stabilizers, benzotriazole UV stabilizers, hindered amine UV stabilizers, substituted acrylonitrile UV stabilizers or triazine UV stabilizers, or a combination of at least two thereof.

[0069] As an optional embodiment, the salicylate UV stabilizer is selected from any one of ethylhexyl salicylate, octyl salicylate, phenyl salicylate, isohexadecanyl salicylate, hexyl salicylate or benzyl salicylate, or a combination of at least two thereof.

[0070] As an optional embodiment, the benzophenone UV stabilizer is selected from any one of 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone or 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, or a combination of at least two thereof.

[0071] As an optional embodiment, the benzotriazole UV stabilizer is selected from any one or a combination of at least two of benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dicyclopentylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-phenyl)-5-chlorobenzotriazole or 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole.

[0072] As an optional embodiment, the hindered amine UV stabilizer is selected from any one of 1,2,2,6,6-pentamethyl-4-piperidinyl sebacate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethylpiperidinol) sebacate or bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, or a combination of at least two thereof.

[0073] As an optional embodiment, the substituted acrylonitrile UV stabilizer is selected from 2-cyano-3,3-diphenylacrylate isooctyl ester and / or 2-cyano-3,3-diphenylacrylate.

[0074] As an optional embodiment, the triazine UV stabilizer is selected from any one of 2,4,6-tris(2'-n-butoxyphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine or 2,4-bis(2-hydroxy-4-butoxyphenyl)-6(2,4-dibutoxyphenyl)-1,3,5-triazine, or a combination of at least two thereof.

[0075] As an optional embodiment, the antioxidant is selected from any one of hindered phenol antioxidants, hindered amine antioxidants, phosphite antioxidants or thioester antioxidants, or a combination of at least two thereof.

[0076] As an optional embodiment, the hindered phenol antioxidant is selected from any one or a combination of at least two of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester, 2,6-di-tert-butyl-4-methylphenol, β-[3,5-di-tert-butyl-4-hydroxyphenyl]propionate octadecyl, 1,1,3-tris[2-methyl-4-hydroxy-5-tert-butylphenyl]butane or β-di-tert-butyl-[4-hydroxyphenyl]propionate octyl ester.

[0077] As an optional embodiment, the phosphite antioxidant is selected from any one of tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite or distearyl pentaerythritol diphosphite or a combination of at least two thereof.

[0078] As an optional embodiment, the thioester antioxidant is selected from any one of stearyl thiodipropionate, dilauryl thiodipropionate, octadecyl thiodipropionate, di(tridecyl)thiodipropionate or di(tetradecyl)thiodipropionate, or a combination of at least two thereof.

[0079] As an optional embodiment, the thickness of the EVA layer is 60 to 90 μm, for example, it can be 60 μm, 62 μm, 64 μm, 65 μm, 66 μm, 68 μm, 70 μm, 72 μm, 74 μm, 75 μm, 76 μm, 78 μm, 80 μm, 82 μm, 84 μm, 85 μm, 86 μm, 88 μm, 90 μm, etc.

[0080] As an optional embodiment, the substrate layer is a PET layer.

[0081] As an optional embodiment, the thickness of the substrate layer is 20 to 40 μm, for example, it can be 20 μm, 22 μm, 24 μm, 25 μm, 26 μm, 28 μm, 30 μm, 32 μm, 34 μm, 35 μm, 36 μm, 38 μm, 40 μm, etc.

[0082] As an optional embodiment, the material of the microstructure coating is selected from any one of aluminum, nickel or silver, or a combination of at least two of them, preferably aluminum.

[0083] As an optional implementation, the microstructure coating is a micro triangular pyramid structure with continuous strips.

[0084] As an optional embodiment, the angle between the line formed by the apex angles of the micro-triangular pyramid and the MD direction is 30-60°, for example, it can be 30°, 35°, 40°, 45°, 46°, 48°, 50°, 52°, 54°, 55°, 60°, etc., preferably 45°.

[0085] As an optional implementation, the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 116-120°, for example, it can be 116°, 117°, 118°, 119°, 120°, etc.

[0086] As an optional implementation, the height of the micro triangular pyramid is 7-8 μm, for example, it can be 7 μm, 7.2 μm, 7.4 μm, 7.5 μm, 7.6 μm, 7.8 μm, 8 μm, etc.

[0087] In a second aspect, the present invention provides a method for preparing the photovoltaic high-adhesion gap reflective film as described in the first aspect, the preparation method comprising:

[0088] The raw materials for preparing the EVA layer are mixed, fed into a screw, and extruded through the die head of the screw to be coated on the other side of the substrate layer with the microstructure coating to obtain the photovoltaic high-bonding gap reflective film.

[0089] As an optional embodiment, the temperature of the screw is 90-100°C, for example, it can be 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C, 100°C, etc.

[0090] As an optional embodiment, the temperature of the screw die is 90-100°C, for example, it can be 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C, 100°C, etc.

[0091] In a third aspect, the present invention provides a use of the photovoltaic high-adhesion gap reflective film as described in the first aspect in the preparation of photovoltaic modules.

[0092] In a fourth aspect, the present invention provides a photovoltaic module, such as Figure 2 As shown, the photovoltaic module includes, from top to bottom, a photovoltaic front glass layer 10, a front packaging film layer 20, a photovoltaic cell layer 30, a rear packaging film layer 40, and a photovoltaic back glass layer 50 with a gap reflective film, which are stacked in sequence; wherein the gap reflective film includes the high-bonding gap reflective film for photovoltaics as described in the first aspect.

[0093] As an optional implementation, the photovoltaic cell layer includes at least two photovoltaic module cell sheets.

[0094] As an optional embodiment, the EVA layer 2 of the photovoltaic high-bonding gap reflective film is bonded to the photovoltaic back glass layer to form a photovoltaic back glass layer 50 with a gap reflective film; and corresponds to and fully covers the gaps between the photovoltaic module cells of the photovoltaic cell layer.

[0095] The present invention is further described below by means of specific examples and comparative examples. However, it should be understood that these examples are only used for more detailed description and should not be construed as limiting the present invention in any form.

[0096] Example 1

[0097] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0098] The thickness of the EVA layer is 75 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0099]

[0100] Among them, the substrate layer is a PET layer with a thickness of 38μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 116°; the height of the micro triangular pyramid is 7.5μm.

[0101] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0102] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0103] Example 2

[0104] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0105] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0106]

[0107] Among them, the substrate layer is a PET layer with a thickness of 38μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connecting the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 118°; the height of the micro triangular pyramid is 7μm.

[0108] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0109] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0110] Example 3

[0111] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0112] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0113]

[0114]

[0115] Among them, the substrate layer is a PET layer with a thickness of 25μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 120°; the height of the micro triangular pyramid is 7.6μm.

[0116] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0117] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0118] Example 4

[0119] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0120] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0121]

[0122]

[0123] Among them, the substrate layer is a PET layer with a thickness of 25μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 116°; the height of the micro triangular pyramid is 7.8μm.

[0124] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0125] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0126] Example 5

[0127] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0128] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0129]

[0130]

[0131] Among them, the substrate layer is a PET layer with a thickness of 38μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 120°; the height of the micro triangular pyramid is 7.2μm.

[0132] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0133] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0134] Example 6

[0135] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0136] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0137]

[0138]

[0139] Among them, the substrate layer is a PET layer with a thickness of 25μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 116°; the height of the micro triangular pyramid is 7μm.

[0140] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0141] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0142] Example 7

[0143] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0144] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0145]

[0146] Among them, the substrate layer is a PET layer with a thickness of 25μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 120°; the height of the micro triangular pyramid is 7.8μm.

[0147] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0148] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0149] Example 8

[0150] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0151] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0152]

[0153] Among them, the substrate layer is a PET layer with a thickness of 25μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 116°; the height of the micro triangular pyramid is 7.5μm.

[0154] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0155] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0156] Example 9

[0157] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0158] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0159]

[0160] Among them, the substrate layer is a PET layer with a thickness of 25μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 120°; the height of the micro triangular pyramid is 7.2μm.

[0161] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0162] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0163] Example 10

[0164] This embodiment provides a photovoltaic high-bonding gap reflective film, the photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer;

[0165] The thickness of the EVA layer is 70 μm, and the raw materials for preparing the EVA layer include the following components in parts by weight:

[0166]

[0167] Among them, the substrate layer is a PET layer with a thickness of 38μm; the microstructure coating is a microstructure aluminum coating layer, and the microstructure coating is a micro triangular pyramid structure with continuous strips, and the angle between the line connected by the vertex angles of the micro triangular pyramid and the MD direction is 45°; the vertex angle of the cross-sectional triangle of the micro triangular pyramid is 116°; the height of the micro triangular pyramid is 7.5μm.

[0168] The photovoltaic high-bonding gap reflective film described in this embodiment is prepared by the following steps:

[0169] High melting point EVA resin, low melting point EVA resin, cross-linking agent, auxiliary cross-linking agent, silane coupling agent, external absorbent and antioxidant are mixed in the above proportions. After the EVA resin and the auxiliary agents are mixed, they enter the screw through suction. The temperature of the screw is set to 95±5℃, the temperature of the die is set to 95±5℃, and they are extruded and coated on the other side of the substrate layer with the microstructure coating through the die.

[0170] Comparative Example 1

[0171] This comparative example provides a gap reflective film, which is different from Example 10 only in that the low-melting point EVA resin is not added, the content of the high-melting point EVA resin is increased to 100 parts, and the other settings are consistent with Example 10.

[0172] Comparative Example 2

[0173] This comparative example provides a gap reflective film, which is different from Example 10 only in that the content of high-melting-point EVA resin is increased to 80 parts, and the content of low-melting-point EVA resin is reduced to 20 parts, and other settings are consistent with Example 10.

[0174] Comparative Example 3

[0175] This comparative example provides a gap reflective film, which is different from Example 10 only in that the content of the cross-linking agent is increased to 0.7 parts, the content of the auxiliary cross-linking agent is increased to 0.45 parts, the content of the silane coupling agent is increased to 0.2 parts, the content of the ultraviolet absorber is reduced to 3.5 parts, and the content of the antioxidant is reduced to 0.5 parts. The other settings are consistent with Example 10.

[0176] Comparative Example 4

[0177] This comparative example provides a gap reflective film, which is different from Example 10 only in that the melting point of the high-melting-point EVA resin is 150° C., and the melting point of the low-melting-point EVA resin is 90° C., and other settings are consistent with Example 10.

[0178] Comparative Example 5

[0179] This comparative example provides a gap reflective film, which is different from Example 10 only in that no high-melting-point EVA resin is added, the content of low-melting-point EVA resin is increased to 100 parts, and other settings are consistent with Example 10.

[0180] Comparative Example 6

[0181] This comparative example provides a gap reflective film, which is different from Example 10 only in that the content of the low-melting-point EVA resin is increased to 80 parts, and the content of the high-melting-point EVA resin is reduced to 20 parts. Other settings are consistent with Example 10.

[0182] Comparative Example 7

[0183] This comparative example provides a gap reflective film, which is different from Example 10 only in that the melting point of the high-melting-point EVA resin is 90° C., and other settings are consistent with Example 10.

[0184] Comparative Example 8

[0185] This comparative example provides a gap reflective film, which is different from Example 10 only in that the melting point of the low-melting-point EVA resin is 30° C., and other settings are consistent with Example 10.

[0186] Test Case

[0187] Test sample:

[0188] The high-adhesion gap reflective films for photovoltaic use provided in Examples 1 to 10 and the gap reflective films provided in Comparative Examples 1 to 8.

[0189] Test method:

[0190] Pre-lamination peeling force with glass: According to the setting conditions of the film laminating machine in the component factory: film laminating temperature 250℃, film laminating pressure 0.2-0.3MPa (Linos film laminating machine), the reflective film is pasted on the embossed glass. According to GB / T2790-1995, a 180° peeling test is performed using a handheld tensile test machine, and a 180° peeling test is performed between the film tape and the glass.

[0191] Vulcanization curve of EVA layer: put the EVA layer into the vulcanization equipment, vulcanizer temperature: 145℃, test time: 15min, test MH value.

[0192] The proportion of bubbles in the film after lamination: According to the lamination method of the components: front glass, adhesive film, battery cell, adhesive film, back glass with reflective film are assembled, and the components are laminated according to the lamination process parameters. The appearance of the film is visually inspected after lamination. The proportion of bubbles in the film after lamination = the number of components with bubbles / the total number of laminated components, and the number of laminated components is 1000.

[0193] Peel strength after lamination with glass: Pre-stick the film tape on the glass, and then laminate it according to the component lamination parameters. After lamination is cooled, use a universal tensile testing machine to test the peel strength of the film tape after lamination with glass in accordance with GB / T2790-1995.

[0194] The specific test results are shown in Table 1:

[0195] Table 1

[0196]

[0197] As shown in Table 1, the pre-lamination peeling force between the gap reflective film provided by the present invention and the glass is good, and the proportion of bubbles after lamination is low. The EVA layer of the gap reflective film provided by the present invention has good pre-lamination adhesion to the glass, and bubbles are not easy to appear after lamination. Among them, Examples 4 to 7 are preferred embodiments, with a pre-lamination peeling force greater than >N, a lamination bubble defect rate ≤0.05%, and an MH value <0.45; Examples 8 to 10 are the best embodiments, with a pre-lamination peeling force >1N, a lamination bubble defect rate ≤0.03%, and an MH value <0.40.

[0198] From Comparative Examples 1 and 2, it can be seen that when the proportion of low-melting-point resin added is small or even zero, the pre-lamination peeling force between the film tape and the glass is low, and the film tape is easy to fall off the glass during the flipping process of the back glass, resulting in missing film tape, causing component degradation. From Comparative Example 3, it can be seen that when more cross-linking agents and cross-linking aids are added, the MH value of the EVA layer is high, indicating that the cross-linking degree of the EVA layer is high. At this time, it is difficult to laminarly remove bubbles from the film tape, and the proportion of bubbles in the component is high. From Comparative Example 4, it can be seen that when the melting point of the added EVA is too high, the film tape cannot be heated by the laminating machine and attached to the glass, and it cannot be laminated into a component.

[0199] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photovoltaic high-bonding gap reflective film, characterized in that: The photovoltaic high-bonding gap reflective film comprises a substrate layer, an EVA layer and a microstructure coating layer, and the EVA layer and the microstructure coating layer are respectively located on both sides of the substrate layer; The raw materials for preparing the EVA layer include, by weight: 40 to 60 parts of high-melting-point EVA resin, 40 to 60 parts of low-melting-point EVA resin, 0.2 to 0.5 parts of a cross-linking agent, 0.1 to 0.4 parts of a co-cross-linking agent, 0.05 to 0.4 parts of a silane coupling agent, 1 to 8 parts of an ultraviolet absorber, and 0.1 to 2 parts of an antioxidant; wherein the melting point of the high-melting-point EVA resin is 60 to 80° C., and the melting point of the low-melting-point EVA resin is 40 to 50° C.

2. The photovoltaic high-adhesion gap reflective film according to claim 1, characterized in that: The raw materials for preparing the EVA layer include, by weight: 40 to 55 parts of high melting point EVA resin, 45 to 60 parts of low melting point EVA resin, 0.23 to 0.48 parts of crosslinking agent, 0.12 to 0.35 parts of auxiliary crosslinking agent, 0.08 to 0.36 parts of silane coupling agent, 2 to 7.5 parts of ultraviolet absorber and 0.3 to 1.5 parts of antioxidant; Preferably, the raw materials for preparing the EVA layer include, by weight: 45-55 parts of high melting point EVA resin, 50-55 parts of low melting point EVA resin, 0.25-0.45 parts of cross-linking agent, 0.15-0.32 parts of auxiliary cross-linking agent, 0.1-0.3 parts of silane coupling agent, 4-7 parts of ultraviolet absorber and 0.5-1.2 parts of antioxidant; Preferably, the VA content in the high melting point EVA resin is 26-30%, preferably 28%; Preferably, the VA content in the low melting point EVA resin is 26-30%, preferably 28%.

3. The photovoltaic high-adhesion gap reflective film according to claim 2, characterized in that: The cross-linking agent is selected from any one or a combination of at least two of tert-butyl peroxycarbonate-2-ethylhexyl ester, di-tert-butyl peroxide or 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; Preferably, the auxiliary crosslinking agent is selected from any one or a combination of at least two of tripropylene trimerisocyanate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, trimethylolpropane trimethacrylate, triallyl cyanurate or ditrimethylolpropane tetraacrylate; Preferably, the silane coupling agent is selected from any one or a combination of at least two of glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane or vinyltri(2-methoxyethoxy)silane; Preferably, the UV absorber is selected from any one or a combination of at least two of salicylate UV stabilizers, benzophenone UV stabilizers, benzotriazole UV stabilizers, hindered amine UV stabilizers, substituted acrylonitrile UV stabilizers or triazine UV stabilizers; Preferably, the antioxidant is selected from any one or a combination of at least two of hindered phenol antioxidants, hindered amine antioxidants, phosphite antioxidants or thioester antioxidants; Preferably, the thickness of the EVA layer is 60-90 μm.

4. The photovoltaic high-adhesion gap reflective film according to claim 1, characterized in that: The substrate layer is a PET layer; Preferably, the substrate layer has a thickness of 20 to 40 μm.

5. The photovoltaic high-adhesion gap reflective film according to claim 1, characterized in that: The material of the microstructure coating is selected from any one of aluminum, nickel or silver or a combination of at least two thereof, preferably aluminum; Preferably, the microstructure coating is a micro triangular pyramid structure having a continuous strip shape; Preferably, the angle between the line formed by the vertex angles of the micro triangular pyramid and the MD direction is 30 to 60°, preferably 45°; Preferably, the vertex angle of the cross-sectional triangle of the micro-triangular pyramid is 116 to 120°; Preferably, the height of the micro triangular pyramid is 7-8 μm.

6. A method for preparing a photovoltaic high-adhesion gap reflective film according to any one of claims 1 to 5, characterized in that: The preparation method comprises: The raw materials for preparing the EVA layer are mixed, fed into a screw, and extruded through the die head of the screw to be coated on the other side of the substrate layer with the microstructure coating to obtain the photovoltaic high-bonding gap reflective film.

7. The method for preparing a photovoltaic high-adhesion gap reflective film according to claim 6, characterized in that: The temperature of the screw is 90-100°C; Preferably, the temperature of the die head of the screw is 90-100°C.

8. Use of the photovoltaic high-adhesion gap reflective film according to any one of claims 1 to 5 in the preparation of photovoltaic modules.

9. A photovoltaic module, characterized in that: The photovoltaic module includes, from top to bottom, a photovoltaic front glass layer, a front packaging film layer, a photovoltaic cell layer, a rear packaging film layer, and a photovoltaic back glass layer with a gap reflective film stacked in sequence; wherein the gap reflective film includes the photovoltaic high-adhesion gap reflective film as described in any one of claims 1 to 5.

10. The photovoltaic module according to claim 9, characterized in that: The photovoltaic cell layer includes at least two photovoltaic module cell sheets; Preferably, the EVA layer of the photovoltaic high-bonding gap reflective film is bonded to the photovoltaic back glass layer; and corresponds to and fully covers the gaps between the photovoltaic module cells of the photovoltaic cell layer.

Images