Light conversion adhesive film as well as preparation method and application thereof

Abstract

The invention provides a light conversion adhesive film and a preparation method and application thereof. The light conversion adhesive film comprises a first EVA cross-linking layer, a first barrier layer, a light conversion layer, a second barrier layer and a second EVA cross-linking layer which are sequentially stacked, the light conversion adhesive film provided by the invention has a multi-layer structure, not only can maintain the service life of the light conversion agent in the light conversion layer, but also can maintain the overall performance of the light conversion adhesive film, has excellent binding power, and can effectively reduce the power attenuation of a photovoltaic module when being used in the photovoltaic module.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic encapsulant technology, specifically relating to a light-converting encapsulant film, its preparation method, and its application. Background Technology

[0002] For heterojunction cells in N-type photovoltaic (PV) systems, they are exceptionally sensitive to high-energy ultraviolet (UV) light. When PV modules are exposed to the outdoors for extended periods, UV light from sunlight can damage the surface structure of the cells, leading to a decrease in module power output. To reduce UV damage, the primary improvement measure is to use high-cutoff films to block UV light and protect the cells. However, this measure reduces the utilization rate of sunlight, thus affecting the power generation of the PV module.

[0003] Light-converting films can convert high-energy ultraviolet light into low-energy visible light, protecting solar cells from ultraviolet damage while improving the photoelectric conversion efficiency of photovoltaic modules. For example, CN102732160A discloses an EVA encapsulating film for improving the spectral conversion efficiency of solar cell modules, which is made by mixing 80-150 parts by weight of ethylene-vinyl acetate copolymer, 0.5-1.5 parts by weight of crosslinking agent, 0.1-1 parts by weight of co-crosslinking agent, 0.1-0.5 parts by weight of antioxidant, 0.1-1 parts by weight of ultraviolet absorber, 0.1-1 parts by weight of light stabilizer, 0.3-1.5 parts by weight of coupling agent, and 0.005-0.3 parts by weight of spectral conversion material. CN106398592A discloses a method for improving the conversion efficiency of solar modules. The high-efficiency EVA encapsulation film includes a transparent front film and a white back film. The front film has the following raw material composition by mass percentage: crosslinking agent 0.05-5%, co-crosslinking agent 0.05-5%, coupling agent 0.05-3%, hydrophobic agent 0.05-2%, light stabilizer 0.02-1.5%, acid stabilizer 0.02-1.0%, ultraviolet light conversion agent 0.02-1.0%, and EVA resin balance. However, existing light conversion films generally use peroxide crosslinking agents and light conversion agents in combination. The light conversion agent is relatively sensitive to peroxide crosslinking agents. The presence of peroxide crosslinking agents will shorten the service life of the light conversion agent, cause yellowing of the light conversion film, and thus reduce the power of photovoltaic modules.

[0004] Therefore, there is an urgent need to develop a light-converting adhesive film that is not prone to yellowing and has excellent adhesion in order to improve the photoelectric conversion efficiency of photovoltaic modules. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a light-converting film, its preparation method and application. Through the design of the light-converting film structure, the service life of the light-converting agent can be maintained while the overall performance of the light-converting film can be preserved. At the same time, it also has excellent adhesion. When used in photovoltaic modules, it can effectively improve their photoelectric conversion efficiency.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a light-converting adhesive film, the light-converting adhesive film comprising a first EVA crosslinking layer, a first barrier layer, a light-converting layer, a second barrier layer, and a second EVA crosslinking layer stacked sequentially.

[0008] The light-converting film provided by this invention is a composite light-converting film with a multi-layer structure. It can maintain the service life of the light-converting agent and the overall performance of the light-converting film. More importantly, it can effectively increase the photoelectric conversion efficiency of photovoltaic modules. The first EVA crosslinking layer and the second EVA crosslinking layer can be bonded to the glass and the solar cells in the photovoltaic module, respectively. The first barrier layer and the second barrier layer can reduce the decomposition effect of the crosslinking agent in the first EVA crosslinking layer and the second EVA crosslinking layer on the light-converting agent, and prevent the light-converting agent from migrating outward, thus protecting the light-converting agent and extending its service life. The light-converting layer can convert ultraviolet light into visible light, increasing the utilization rate of sunlight by the photovoltaic module while reducing its power attenuation.

[0009] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0010] As a preferred technical solution, the raw materials for preparing the first EVA crosslinking layer and the second EVA crosslinking layer each independently include 85-97 parts by weight of the first EVA, 0.1-5 parts by weight of the crosslinking agent, 0.1-3 parts by weight of the first co-crosslinking agent, 0.3-3 parts by weight of the first silane coupling agent, and 0.2-3 parts by weight of the silane oligomer.

[0011] In this invention, the first EVA crosslinking layer and the second EVA crosslinking layer are compounded by a first silane coupling agent and a silane oligomer, which can improve and maintain the adhesion of the first EVA crosslinking layer and the second EVA crosslinking layer for a long time.

[0012] In this invention, the first EVA can be obtained by purchase, for example, it can be purchased from one or more of the following: Sirbon UE2825, Lianhong FL02528, Hanwha E282PV, LG EP28025, and Formosa Plastics 7760S.

[0013] The first EVA is 85-97 parts by weight, for example, it can be 85 parts by weight, 86 parts by weight, 87 parts by weight, 88 parts by weight, 89 parts by weight, 90 parts by weight, 91 parts by weight, 92 parts by weight, 93 parts by weight, 94 parts by weight, 95 parts by weight, 96 parts by weight, 97 parts by weight, etc.

[0014] The crosslinking agent is 0.1-5 parts by weight, for example, it can be 0.1 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, etc.

[0015] The first crosslinking agent is 0.1-3 parts by weight, for example, it can be 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 1.8 parts by weight, 2 parts by weight, 2.2 parts by weight, 2.5 parts by weight, 2.8 parts by weight, 3 parts by weight, etc.

[0016] The first silane coupling agent is 0.3-3 parts by weight, for example, it can be 0.3 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 1.8 parts by weight, 2 parts by weight, 2.2 parts by weight, 2.5 parts by weight, 2.8 parts by weight, 3 parts by weight, etc.

[0017] The silane oligomer is present in amounts of 0.2-3 parts by weight, for example, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 1.8 parts by weight, 2 parts by weight, 2.2 parts by weight, 2.5 parts by weight, 2.8 parts by weight, 3 parts by weight, etc.

[0018] Preferably, by weight, the raw materials for preparing the first barrier layer and the second barrier layer each independently include 90-98 parts by weight of the substrate, 0.1-0.5 parts by weight of the second silane coupling agent, and 0.1-5 parts by weight of the second co-crosslinking agent.

[0019] The substrate is 90-98 parts by weight, for example, it can be 90 parts by weight, 90.5 parts by weight, 91 parts by weight, 91.5 parts by weight, 92 parts by weight, 92.5 parts by weight, 93 parts by weight, 93.5 parts by weight, 94 parts by weight, 94.5 parts by weight, 95 parts by weight, 95.5 parts by weight, 96 parts by weight, 96.5 parts by weight, 97 parts by weight, 97.5 parts by weight, 98 parts by weight, etc.

[0020] The second silane coupling agent is 0.1-0.5 parts by weight, for example, it can be 0.1 parts by weight, 0.15 parts by weight, 0.2 parts by weight, 0.25 parts by weight, 0.3 parts by weight, 0.35 parts by weight, 0.4 parts by weight, 0.45 parts by weight, 0.5 parts by weight, etc.

[0021] The second crosslinking agent is 0.1-5 parts by weight, for example, it can be 0.1 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, etc.

[0022] Preferably, the raw materials for preparing the light conversion layer include 90-98 parts by weight of second EVA, 0.1-4 parts by weight of first acrylate, 0.3-3 parts by weight of third silane coupling agent, and 0.1-0.3 parts by weight of light conversion agent.

[0023] In this invention, the second EVA can be obtained by purchase, for example, it can be purchased from one or more of Sirbon UE2806, Lianhong UL00628, and Formosa Plastics 7670S.

[0024] The second EVA is 90-98 parts by weight, for example, it can be 90 parts by weight, 90.5 parts by weight, 91 parts by weight, 91.5 parts by weight, 92 parts by weight, 92.5 parts by weight, 93 parts by weight, 93.5 parts by weight, 94 parts by weight, 94.5 parts by weight, 95 parts by weight, 95.5 parts by weight, 96 parts by weight, 96.5 parts by weight, 97 parts by weight, 97.5 parts by weight, 98 parts by weight, etc.

[0025] The first acrylate is 0.1-4 parts by weight, for example, it can be 0.1 parts by weight, 0.15 parts by weight, 0.2 parts by weight, 0.25 parts by weight, 0.3 parts by weight, 0.35 parts by weight, 0.4 parts by weight, etc.

[0026] The third silane coupling agent is 0.3-3 parts by weight, for example, it can be 0.3 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 1.8 parts by weight, 2 parts by weight, 2.2 parts by weight, 2.5 parts by weight, 2.8 parts by weight, 3 parts by weight, etc.

[0027] The light-converting agent is 0.1-0.3 parts by weight, for example, it can be 0.1 parts by weight, 0.12 parts by weight, 0.15 parts by weight, 0.18 parts by weight, 0.2 parts by weight, 0.22 parts by weight, 0.25 parts by weight, 0.28 parts by weight, 0.3 parts by weight, etc.

[0028] Preferably, the melt flow index of the first EVA at 190°C and 2.16 kg is 15-30 g / 10 min, for example, it can be 15 g / 10 min, 16 g / 10 min, 17 g / 10 min, 18 g / 10 min, 19 g / 10 min, 20 g / 10 min, 21 g / 10 min, 22 g / 10 min, 23 g / 10 min, 24 g / 10 min, 25 g / 10 min, 26 g / 10 min, 27 g / 10 min, 28 g / 10 min, 29 g / 10 min, etc.

[0029] Preferably, the crosslinking agent comprises any one or a combination of at least two of the following: 2-ethylhexyl carbonate tert-butyl peroxide, tert-butyl peroxycarbonate isopropyl peroxide, 2-ethylhexyl carbonate tert-amyl peroxy, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, benzoyl peroxide, di-tert-butyl peroxide, or 1-bis(tert-butyl peroxide)-3,3,5-trimethylcyclohexane.

[0030] Preferably, the number average molecular weight of the silane oligomer is 800-1200, for example, it can be 800, 820, 840, 860, 880, 900, 920, 940, 960, 980, 1000, 1020, 1040, 1060, 1080, 1100, 1120, 1140, 1160, 1180, 1200, etc.

[0031] Preferably, the silane oligomer includes any one or a combination of at least two of the following: methacryloxypropyltrimethoxysilane derivatives, acyloxysilane oligomers, alkylaminosilane oligomers, epoxysilane oligomers, acyloxyvinylsilane oligomers, aminosilane oligomers, small molecule polysiloxanes, octylsilane oligomers, alkylvinylsilane oligomers, or hybrid functional silanes.

[0032] In this invention, the silane oligomers can be purchased. For example, the acyloxysilane oligomers can be purchased from, but are not limited to, Shanghai Kaistar Chemical New Materials Co., Ltd.; the alkylaminosilane oligomers can be purchased from, but are not limited to, Anhui Sibao Organosilicon New Materials Co., Ltd.; the acyloxyvinylsilane oligomers can be purchased from, but are not limited to, Hubei Jianghan New Materials Co., Ltd.; and the epoxysilane oligomers can be purchased from, but are not limited to, Shandong Siker New Materials Co., Ltd.

[0033] Preferably, the substrate comprises any one or a combination of at least two of polyethylene, polypropylene, polymethyl methacrylate, ethylene-(meth)acrylic acid copolymer, ethylene-methyl methacrylate copolymer, or ethylene-octene copolymer.

[0034] Preferably, the melt index of the second EVA at 190°C and 2.16 kg is 0.5-10 g / 10 min, for example, it can be 0.5 g / 10 min, 1 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min, 10 g / 10 min, etc.

[0035] Preferably, the light conversion agent includes an organic light conversion agent.

[0036] Preferably, the light-converting agent comprises 4,7-bis(4-(tert-butyl)phenyl)-2-isobutyl-2H-benzotriazole.

[0037] Preferably, the first co-crosslinking agent and the second co-crosslinking agent each independently comprise any one or a combination of at least two of the following: second acrylate, triallyl isocyanurate, trimethallyl isocyanate, or triallyl cyanurate.

[0038] Preferably, the first acrylate and the second acrylate each independently comprise any one or a combination of at least two of the following: trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolpropane tetraacrylate, pentaerythritol ethoxylate tetraacrylate, glycerol ethoxylate triacrylate, trimethylolpropane ethoxylate triacrylate, glycerol ethoxylate triacrylate, polyethylene glycol diacrylate, tricyclodecanediethanol diacrylate, or ditrimethylolpropane tetraacrylate.

[0039] Preferably, the first silane coupling agent, the second silane coupling agent, and the third silane coupling agent each independently comprise any one or a combination of at least two of the following: methacryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxyethoxy)silane, vinyltriacetoxysilane, propenyltriperoxide-tert-butylsilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminopropyltriisopropoxysilane, γ-aminopropyltriethoxysilane, or propyltrioxyethylisocyanate.

[0040] Preferably, the raw materials for preparing the first EVA crosslinking layer and the second EVA crosslinking layer each independently include 0.1-0.3 parts by weight of a first light stabilizer (e.g., 0.1 parts by weight, 0.12 parts by weight, 0.15 parts by weight, 0.18 parts by weight, 0.2 parts by weight, 0.22 parts by weight, 0.25 parts by weight, 0.28 parts by weight, 0.3 parts by weight, etc.) and 0.1-0.3 parts by weight of a first antioxidant (e.g., 0.1 parts by weight, 0.12 parts by weight, 0.15 parts by weight, 0.18 parts by weight, 0.2 parts by weight, 0.22 parts by weight, 0.25 parts by weight, 0.28 parts by weight, 0.3 parts by weight, etc.).

[0041] Preferably, the raw materials for preparing the first barrier layer and the second barrier layer each independently include 0.1-5 parts by weight of an initiator (e.g., 0.1 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, etc.) and 0.1-0.3 parts by weight of a second light stabilizer (e.g., 0.1 parts by weight, 0.12 parts by weight, 0.15 parts by weight, 0.18 parts by weight, 0.2 parts by weight, 0.22 parts by weight, 0.25 parts by weight, 0.28 parts by weight, 0.3 parts by weight, etc.).

[0042] Preferably, the initiator includes any one or a combination of at least two of benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone or 2-hydroxy-2-methyl-1-phenyl ketone.

[0043] Preferably, the raw materials for preparing the light conversion layer further include 0.1-0.3 parts by weight of a third light stabilizer (e.g., 0.1 parts by weight, 0.12 parts by weight, 0.15 parts by weight, 0.18 parts by weight, 0.2 parts by weight, 0.22 parts by weight, 0.25 parts by weight, 0.28 parts by weight, 0.3 parts by weight, etc.) and 0.1-0.3 parts by weight of a second antioxidant (e.g., 0.1 parts by weight, 0.12 parts by weight, 0.15 parts by weight, 0.18 parts by weight, 0.2 parts by weight, 0.22 parts by weight, 0.25 parts by weight, 0.28 parts by weight, 0.3 parts by weight, etc.).

[0044] Preferably, the first light stabilizer, the second light stabilizer, and the third light stabilizer each independently comprise any one or a combination of at least two of the following: succinic acid and (a polymer of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol), bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(2,4-di-tert-butylphenyl) phosphite, 2,2,6,6-tetramethyl-4-piperidinyl ester, or polysuccinic acid (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0045] Preferably, the first antioxidant and the second antioxidant each independently comprise any one or a combination of at least two of the following: 2,6-di-tert-butyl-p-cresol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), tris[2,4-di-tert-butylphenyl]phosphite, or 6,6'-di-tert-butyl-2,2'-thiobis(p-cresol).

[0046] Preferably, the thickness of the first EVA crosslinking layer and the second EVA crosslinking layer are each independently 50-200 μm, for example, 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, etc.

[0047] Preferably, the thickness of the first barrier layer and the second barrier layer is independently 10-100μm, for example, it can be 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.

[0048] Preferably, the thickness of the light-converting layer is 100-400μm, for example, it can be 100μm, 120μm, 140μm, 160μm, 180μm, 200μm, 220μm, 240μm, 260μm, 280μm, 300μm, 320μm, 340μm, 360μm, 380μm, 400μm, etc.

[0049] In a second aspect, the present invention provides a method for preparing a light-converting adhesive film as described in the first aspect, the method comprising:

[0050] The raw materials for preparing the first EVA crosslinking layer, the first barrier layer, the light conversion layer, the second barrier layer, and the second EVA crosslinking layer are co-extruded and then pressed together to obtain the light conversion film.

[0051] Thirdly, the present invention provides an application of the light-converting adhesive film as described in the first aspect in solar cells.

[0052] Fourthly, the present invention provides a photovoltaic module, the photovoltaic module comprising a solar cell as described in the third aspect or a light-converting adhesive film as described in the first aspect.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The light-converting film provided by this invention can maintain the service life of the light-converting agent in the light-converting layer while maintaining the overall performance of the light-converting film. The yellowing index of the light-converting film is low, ranging from 0.32 to 0.87. The light-converting film provided by this invention also has excellent initial adhesion, with an initial adhesion strength of 113-210 N / cm. When the light-converting film provided by this invention is used in photovoltaic modules, it can effectively reduce the power attenuation, with a power attenuation of 1.2-2.8%. Attached Figure Description

[0055] Figure 1 This is a schematic cross-sectional view of the light-converting adhesive film provided by the present invention;

[0056] Among them, 101-first EVA crosslinking layer, 102-first barrier layer, 103-light conversion layer, 104-second barrier layer, 105-second EVA crosslinking layer. Detailed Implementation

[0057] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0058] The sources of some components in the following examples and comparative examples are as follows:

[0059] (1) EVA: Sirbon UE2825 (melt flow index of 25 g / min), UE2806 (melt flow index of 6 g / min); Formosa Plastics 7760S (melt flow index of 25 g / min), 7670S (melt flow index of 10 g / min); Hanwha E282PV (melt flow index of 25 g / min); LG EP28025 (melt flow index of 25 g / min); Lianhong FL02528 (melt flow index of 25 g / min), UL00628 (melt flow index of 5.5 g / min);

[0060] (2) Acyloxysilane oligomers: purchased from Shanghai Kaistar Chemical New Materials Co., Ltd., with a number average molecular weight of 980;

[0061] (3) Alkylaminosilane oligomers: purchased from Anhui Sibao Organosilicon New Materials Co., Ltd., with a number average molecular weight of 960;

[0062] (4) Epoxy silane oligomers: purchased from Shandong Silicon Science New Materials Co., Ltd., with a number average molecular weight of 1000;

[0063] (5) Acyloxyvinylsilane oligomers: purchased from Hubei Jianghan New Materials Co., Ltd., with a number average molecular weight of 950;

[0064] (6) Ethylene-methyl methacrylate copolymer: purchased from Sumitomo Chemical Co., Ltd., WH401-F;

[0065] (7) Ethylene-octene copolymer: purchased from Dow Chemical China Investment Co., Ltd., ENGAGE TM PV 8660;

[0066] (8) Polyethylene: Purchased from Dow Chemical China Investment Co., Ltd., ELITE TM 5401G;

[0067] (9) Polymethyl methacrylate: purchased from Sigma-Aldrich, 182230.

[0068] Example 1

[0069] A light-converting adhesive film, the cross-sectional structure of which is shown in the schematic diagram below. Figure 1 As shown, the structure includes a first EVA crosslinking layer 101 (100 μm thick), a first barrier layer 102 (10 μm thick), a light conversion layer 103 (300 μm thick), a second barrier layer 104 (10 μm thick), and a second EVA crosslinking layer 105 (100 μm thick), which are sequentially stacked. The raw materials for each layer are shown in Table 1.

[0070] Table 1

[0071]

[0072]

[0073] The method for preparing the light-converting adhesive film includes the following steps: the raw materials for preparing the first EVA crosslinking layer, the raw materials for preparing the first barrier layer, the raw materials for preparing the light-converting layer, the raw materials for preparing the second barrier layer, and the raw materials for preparing the second EVA crosslinking layer are stirred evenly in different mixers, then mixed in a sealed container and left to stand for a period of time. After that, the raw materials for preparing each layer are added to a co-extrusion extruder, and after multi-layer co-extrusion, they are pressed and cooled to form a film to obtain the light-converting adhesive film.

[0074] Example 2

[0075] A light-converting adhesive film, comprising a first EVA crosslinking layer (100 μm thick), a first barrier layer (30 μm thick), a light-converting layer (300 μm thick), a second barrier layer (30 μm thick), and a second EVA crosslinking layer (100 μm thick) stacked sequentially; the raw materials for each layer are shown in Table 2.

[0076] Table 2

[0077]

[0078]

[0079] The method for preparing the light-converting adhesive film is the same as in Example 1.

[0080] Example 3

[0081] A light-converting adhesive film, comprising a first EVA crosslinking layer (100 μm thick), a first barrier layer (50 μm thick), a light-converting layer (300 μm thick), a second barrier layer (50 μm thick), and a second EVA crosslinking layer (100 μm thick) stacked sequentially; the raw materials for each layer are shown in Table 3.

[0082] Table 3

[0083]

[0084]

[0085] The method for preparing the light-converting adhesive film is the same as in Example 1.

[0086] Example 4

[0087] A light-converting adhesive film, comprising a first EVA crosslinking layer (100 μm thick), a first barrier layer (80 μm thick), a light-converting layer (300 μm thick), a second barrier layer (80 μm thick), and a second EVA crosslinking layer (100 μm thick) stacked sequentially; the raw materials for each layer are shown in Table 4.

[0088] Table 4

[0089]

[0090]

[0091] The method for preparing the light-converting adhesive film is the same as in Example 1.

[0092] Example 5

[0093] A light-converting adhesive film, comprising a first EVA crosslinking layer (50 μm thick), a first barrier layer (80 μm thick), a light-converting layer (300 μm thick), a second barrier layer (80 μm thick), and a second EVA crosslinking layer (50 μm thick) stacked sequentially; the raw materials for each layer are shown in Table 5.

[0094] Table 5

[0095]

[0096] The method for preparing the light-converting adhesive film is the same as in Example 1.

[0097] Example 6

[0098] A light-converting adhesive film, comprising a first EVA crosslinking layer (60 μm thick), a first barrier layer (80 μm thick), a light-converting layer (300 μm thick), a second barrier layer (80 μm thick), and a second EVA crosslinking layer (60 μm thick) stacked sequentially; the raw materials for each layer are shown in Table 6.

[0099] Table 6

[0100]

[0101]

[0102] The method for preparing the light-converting adhesive film is the same as in Example 1.

[0103] Example 7

[0104] A light-converting adhesive film, comprising a first EVA crosslinking layer (80 μm thick), a first barrier layer (80 μm thick), a light-converting layer (300 μm thick), a second barrier layer (80 μm thick), and a second EVA crosslinking layer (80 μm thick) stacked sequentially; the raw materials for each layer are shown in Table 7.

[0105] Table 7

[0106]

[0107]

[0108] The method for preparing the light-converting adhesive film is the same as in Example 1.

[0109] Example 8

[0110] A light-converting adhesive film and its preparation method are disclosed. The only difference between this film and Example 1 is that the acyloxysilane oligomer in the raw materials for preparing the first and second EVA crosslinking layers is replaced with an equal amount of methacryloyloxypropyltrimethoxysilane. All other raw materials, process parameters and steps are the same as in Example 1.

[0111] Example 9

[0112] A light-converting adhesive film and its preparation method are disclosed. The only difference between the film and Example 1 is that the thickness of the first barrier layer and the second barrier layer are both 5 μm. The other raw materials, process parameters and steps are the same as those in Example 1.

[0113] Example 10

[0114] A light-converting adhesive film and its preparation method are disclosed. The only difference between the film and Example 1 is that the thickness of the first barrier layer and the second barrier layer are both 105 μm. The other raw materials, process parameters and steps are the same as those in Example 1.

[0115] Comparative Example 1

[0116] A light-converting adhesive film, comprising a first EVA crosslinking layer (100 μm thick), a light-converting layer (300 μm thick), and a second EVA crosslinking layer (100 μm thick) stacked sequentially, wherein the raw materials for preparing the first EVA crosslinking layer, the light-converting layer, and the second EVA crosslinking layer are the same as in Example 1, and the preparation method of the light-converting adhesive film is as described in Example 1.

[0117] Performance testing

[0118] The light transfer film provided in the above embodiments and comparative examples is used in photovoltaic modules. The preparation method of the photovoltaic module includes: front glass (Xinyi Glass, 2272mm×1128mm×2mm), light transfer film, solar cell (Canadian Solar, CC10MB-HJT), light transfer film and back glass (2272mm×1128mm×2mm) are stacked in sequence, and the photovoltaic module is obtained after lamination.

[0119] (1) Module power: The photovoltaic modules were subjected to UV aging tests with an irradiation intensity of 200W / m. 2 Cumulative irradiation: 60 kWh / m 2 The power of the photovoltaic module before and after UV irradiation was measured using a multi-functional photovoltaic IV curve tester (Fluke, SMFT-1000), and the power degradation before and after UV irradiation was calculated according to the following formula:

[0120]

[0121] (2) Yellowing index: In accordance with GB 2409 "Test method for yellow index of plastic", the yellowing index (ΔYI) of photovoltaic modules before and after UV aging test was determined using a colorimeter (Konica Minolta, Japan, CM-2300D);

[0122] (3) Initial adhesion: According to GB / T29848-2018 "Ethylene-vinyl acetate copolymer (EVA) film for photovoltaic module encapsulation", the initial adhesion between the light-converting film and the glass was tested using a Ligo testing equipment (HF-9006S);

[0123] The light-converting films provided in Examples 1-10 and Comparative Example 1 were tested according to the above method, and the test results are shown in Table 8:

[0124] Table 8

[0125] Initial bond strength (N / cm) Yellowing Index Power attenuation (%) Example 1 159 0.71 1.9 Example 2 182 0.59 1.5 Example 3 190 0.45 1.4 Example 4 210 0.32 1.2 Example 5 162 0.38 1.7 Example 6 170 0.36 1.6 Example 7 178 0.35 1.6 Example 8 113 0.8 2.1 Example 9 158 0.87 2.8 Example 10 160 0.78 2.3 Comparative Example 1 155 1.96 4.3

[0126] As can be seen from the test data in Table 8, compared with Comparative Example 1, the photovoltaic modules prepared using the light-converting films provided in Examples 1-10 show significantly reduced power decay and lower yellowing index after UV aging, indicating a significant improvement in the UV resistance of the photovoltaic modules. The inclusion of a first EVA crosslinking layer and a second EVA crosslinking layer in the light-converting film maintains high peel strength to the glass, ensuring that the module does not delaminate during use. The inclusion of the first and second barrier layers not only bonds the first and second EVA crosslinking layers to the light-converting layer but also prevents the reaction of the light-converting layer with oxygen free radicals released from the peroxide crosslinking agents in the first and second EVA crosslinking layers, thus avoiding the aging and decomposition of the light-converting agent. Simultaneously, it inhibits the outward migration and precipitation of the light-converting agent, extending the service life of the light-converting film and reducing power decay of the photovoltaic module after long-term UV aging.

[0127] As can be seen from the comparison between Example 1 and Example 8, the present invention prepares a light-converting adhesive film with high adhesion to glass by using silane coupling agent and silane oligomer in combination.

[0128] A comparison between Example 1 and Example 9 shows that if the thickness of the first and second barrier layers is too small, the protective effect of the barrier layers on the light-converting agent and the effect of inhibiting transfer are both weak, and the yellowing index and power attenuation of the light-converting film are large.

[0129] A comparison between Example 1 and Example 10 shows that if the thickness of the first and second barrier layers is too large, the yellowing index of the light conversion film increases, and the power attenuation also increases. Therefore, a suitable barrier layer thickness is beneficial to maintaining the power of the photovoltaic module.

[0130] The applicant declares that the present invention is illustrated by the above embodiments to demonstrate the light-converting film, its preparation method, and its application. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A light-converting adhesive film, characterized in that, The light-converting adhesive film comprises a first EVA crosslinking layer, a first barrier layer, a light-converting layer, a second barrier layer, and a second EVA crosslinking layer, which are stacked sequentially.

2. The light-converting adhesive film according to claim 1, characterized in that, By weight, the raw materials for preparing the first EVA crosslinking layer and the second EVA crosslinking layer each independently include 85-97 parts by weight of the first EVA, 0.1-5 parts by weight of the crosslinking agent, 0.1-3 parts by weight of the first co-crosslinking agent, 0.3-3 parts by weight of the first silane coupling agent, and 0.2-3 parts by weight of the silane oligomer. Preferably, by weight, the raw materials for preparing the first barrier layer and the second barrier layer each independently include 90-98 parts by weight of the substrate, 0.1-0.5 parts by weight of the second silane coupling agent, and 0.1-5 parts by weight of the second co-crosslinking agent. Preferably, the raw materials for preparing the light conversion layer include 90-98 parts by weight of second EVA, 0.1-4 parts by weight of first acrylate, 0.3-3 parts by weight of third silane coupling agent, and 0.1-0.3 parts by weight of light conversion agent.

3. The light-converting adhesive film according to claim 2, characterized in that, The melt flow index of the first EVA at 190℃ and 2.16kg was 15-30g / 10min; Preferably, the crosslinking agent comprises any one or a combination of at least two of the following: 2-ethylhexyl carbonate tert-butyl peroxide, tert-butyl peroxycarbonate isopropyl peroxide, 2-ethylhexyl carbonate tert-amyl peroxy, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, benzoyl peroxide, di-tert-butyl peroxide, or 1-bis(tert-butyl peroxide)-3,3,5-trimethylcyclohexane. Preferably, the number-average molecular weight of the silane oligomer is 800-1200; Preferably, the silane oligomer includes any one or a combination of at least two of the following: methacryloxypropyltrimethoxysilane derivatives, acyloxysilane oligomers, alkylaminosilane oligomers, epoxysilane oligomers, acyloxyvinylsilane oligomers, aminosilane oligomers, small molecule polysiloxanes, octylsilane oligomers, alkylvinylsilane oligomers, or hybrid functional silanes.

4. The light-converting adhesive film according to claim 2 or 3, characterized in that, The substrate includes any one or a combination of at least two of polyethylene, polypropylene, polymethyl methacrylate, ethylene-(meth)acrylic acid copolymer, ethylene-methyl methacrylate copolymer, or ethylene-octene copolymer.

5. The light-converting adhesive film according to any one of claims 2-4, characterized in that, The melt flow index of the second EVA at 190℃ and 2.16kg was 0.5-10g / 10min; Preferably, the light conversion agent includes an organic light conversion agent; Preferably, the light-converting agent comprises 4,7-bis(4-(tert-butyl)phenyl)-2-isobutyl-2H-benzotriazole; Preferably, the first co-crosslinking agent and the second co-crosslinking agent each independently comprise any one or a combination of at least two of the following: second acrylate, triallyl isocyanurate, trimethallyl isocyanate, or triallyl cyanurate. Preferably, the first acrylate and the second acrylate each independently comprise any one or a combination of at least two of the following: trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolpropane tetraacrylate, pentaerythritol ethoxylate tetraacrylate, glycerol ethoxylate triacrylate, trimethylolpropane triacrylate, glycerol ethoxylate triacrylate, polyethylene glycol diacrylate, tricyclodecanedimethylol diacrylate, or ditrimethylolpropane tetraacrylate. Preferably, the first silane coupling agent, the second silane coupling agent, and the third silane coupling agent each independently comprise any one or a combination of at least two of the following: methacryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxyethoxy)silane, vinyltriacetoxysilane, propenyltriperoxide-tert-butylsilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, aminopropyltriisopropoxysilane, γ-aminopropyltriethoxysilane, or propyltrioxyethylisocyanate.

6. The light-converting adhesive film according to any one of claims 2-5, characterized in that, The raw materials for preparing the first EVA crosslinking layer and the second EVA crosslinking layer each independently include 0.1-0.3 parts by weight of a first light stabilizer and 0.1-0.3 parts by weight of a first antioxidant; Preferably, the raw materials for preparing the first barrier layer and the second barrier layer each independently include 0.1-5 parts by weight of an initiator and 0.1-0.3 parts by weight of a second light stabilizer; Preferably, the initiator comprises any one or a combination of at least two of benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone or 2-hydroxy-2-methyl-1-phenyl ketone; Preferably, the raw materials for preparing the light conversion layer further include 0.1-0.3 parts by weight of a third light stabilizer and 0.1-0.3 parts by weight of a second antioxidant; Preferably, the first light stabilizer, the second light stabilizer, and the third light stabilizer each independently comprise any one or a combination of at least two of the following: succinic acid and (a polymer of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol), bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(2,4-di-tert-butylphenyl) phosphite, 2,2,6,6-tetramethyl-4-piperidinyl ester, or polysuccinic acid (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol); Preferably, the first antioxidant and the second antioxidant each independently comprise any one or a combination of at least two of the following: 2,6-di-tert-butyl-p-cresol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), tris[2,4-di-tert-butylphenyl]phosphite, or 6,6'-di-tert-butyl-2,2'-thiobis(p-cresol).

7. The light-converting adhesive film according to any one of claims 1-6, characterized in that, The thickness of the first EVA crosslinking layer and the second EVA crosslinking layer are each independently 50-200 μm; Preferably, the thickness of the first barrier layer and the second barrier layer is independently 10-100 μm; Preferably, the thickness of the light-converting layer is 100-400 μm.

8. A method for preparing a light-converting adhesive film as described in any one of claims 1-7, characterized in that, The preparation method includes: The raw materials for preparing the first EVA crosslinking layer, the first barrier layer, the light conversion layer, the second barrier layer, and the second EVA crosslinking layer are co-extruded and then pressed together to obtain the light conversion film.

9. The application of the light-converting adhesive film as described in any one of claims 1-7 in a solar cell.

10. A photovoltaic module, characterized in that, The photovoltaic module includes the solar cell as described in claim 9 or the light-converting adhesive film as described in any one of claims 1-7.

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