Multi-layer packaging adhesive film

Abstract

The invention discloses a multilayer packaging adhesive film which comprises a polyolefin layer, two transition layers and two EVA layers, the two transition layers are distributed on the two sides of the polyolefin layer, and one EVA layer is arranged on the outer side of each transition layer; the main body material of the polyolefin layer is a polyolefin material, and the main body resin of the EVA layer is EVA resin; according to the weight ratio, the EVA layer further comprises 0.01-1% of a deacidification agent A and a catalyst which accounts for 0.1-5% of the weight of the deacidification agent A, the transition layer comprises 0.01-1% of the deacidification agent A and a catalyst which accounts for 0.1-5% of the weight of the deacidification agent A, and the polyolefin layer further comprises 0.01-1% of a deacidification agent B; the acid removal agent A is carbodiimide or a carbodiimide compound; and the deacidification agent B is a silane coupling agent with amino groups. Acetate ions generated by EVA in the long-term use of the photovoltaic module can be consumed, the PID effect is reduced, the light transmittance is not affected, and the interface adhesive force between layers can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic module packaging films, and in particular to a multi-layer packaging film. Background Art

[0002] Photovoltaic technology is developing rapidly, and battery technology is also rapidly iterating, from PERC to TOPCON, HJT, perovskite and other technical routes. As batteries advance, they are becoming more and more sensitive to water vapor, so the original packaging materials will not be able to meet the requirements of existing battery technology.

[0003] The original packaging film is generally an EVA single-layer structure, and its water vapor transmission rate is generally 20g / m 2 .day (38℃, 90%RH) or above. EVA is a copolymer of ethylene-vinyl acetate. Its ester bonds will hydrolyze under high temperature and high humidity conditions to produce free acetate ions, which will corrode the circuit and cause the potential induced degradation (PID) effect of photovoltaic modules.

[0004] In recent years, POE film and EVA / POE / EVA (EPE) film have been developed. POE is a copolymer of ethylene and butene or octene, a non-polar material, with a much higher volume resistivity and water vapor permeability than EVA, so it has stronger anti-PID ability. However, the price of POE particles is expensive, making the cost of POE film much higher than that of EVA film. Therefore, EPE film has achieved a balance between cost and performance, but because EVA and POE are different materials, the adhesion between their layers is weak, so that EPE film may have the risk of delamination. In addition, when processing the film, a variety of additives need to be added. The additives are generally polar and have better compatibility with polar EVA. Therefore, over time, the additives in the POE layer will continue to migrate to the EVA layer with strong polarity and strong absorption, causing changes in the internal structural properties of the film, and the bonding between POE and EVA layers decreases. There is even a risk of the POE layer being squeezed out and delaminated during component lamination. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a multi-layer encapsulation film, which adopts a reactive acid scavenger system, which can consume the acetate ions generated by EVA during the long-term use of photovoltaic modules, thereby reducing the PID effect, and will not affect the transmittance, and can also improve the interface adhesion between layers.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] A multi-layer packaging adhesive film comprises a polyolefin layer, two transition layers and two EVA layers, wherein the two transition layers are distributed on both sides of the polyolefin layer, and an EVA layer is arranged on the outer side of each transition layer; the main material of the polyolefin layer is a polyolefin material, and the main resin of the EVA layer is an EVA resin; by weight, the EVA layer further comprises 0.01-1% of an acid scavenger A and 0.1-5% of a catalyst relative to the weight of the acid scavenger A, the transition layer comprises 0.01-1% of an acid scavenger A and 0.1-5% of a catalyst relative to the weight of the acid scavenger A, and the polyolefin layer further comprises 0.01-1% of an acid scavenger B; the acid scavenger A is a carbodiimide or a carbodiimide compound; and the acid scavenger B is a silane coupling agent with an amino group.

[0008] Preferably, the polyolefin material is selected from one or a blend of two or more of HDPE, LDPE, LLDPE, ULDPE and POE.

[0009] Preferably, the main polymer material of the transition layer is selected from EMA, maleic anhydride grafted polyethylene, maleic anhydride grafted POE, GMA grafted POE, GMA grafted EVA, GMA grafted EMA, GMA grafted EBA, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, silane coupling agent grafted modified POE, EAA or a blend of two or more thereof.

[0010] Preferably, the acid scavenger A is selected from one or a combination of two or more of dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0011] Preferably, the acid scavenger B is selected from one or a combination of two or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, anilinomethyltriethoxysilane and anilinomethyltrimethoxysilane.

[0012] Preferably, the catalyst is selected from one or a combination of two or more of 4-N,N-dimethylpyridine, 1-hydroxybenzotriazole, 4-pyrrolidinylpyridine, 1-hydroxy-7-azabenzotriazole, N-hydroxyphthalimide, and pentafluorophenol.

[0013] Furthermore, the polyolefin layer, transition layer and EVA layer further include a cross-linking agent, a co-cross-linking agent and a silane coupling agent respectively.

[0014] Preferably, the crosslinking agent is an organic peroxide crosslinking agent, and the organic peroxide crosslinking agent is selected from diisopropylbenzene peroxide, tert-butyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-amyl peroxy-2-ethylhexyl carbonate, di(2-ethyl)hexyl peroxydicarbonate, tert-amyl peroxy-2-ethylhexyl carbonate, benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, or a combination of two or more thereof;

[0015] The auxiliary cross-linking agent is selected from one or a combination of two or more of triallyl isocyanurate, 3-(trimethoxysilyl)propyl methacrylate, 3-vinylphenol, triallyl cyanurate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate;

[0016] The silane coupling agent is selected from one or a combination of two or more of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl triperoxide tert-butyl silane, vinyl triacetoxysilane, vinyl tri(β-methoxyethoxy)silane, and γ-(methacryloyloxy)propyl trimethoxysilane.

[0017] Furthermore, the polyolefin layer, transition layer and EVA layer respectively further include one or more of an antioxidant, a light stabilizer, an ultraviolet absorber, a filler and an inorganic additive.

[0018] Preferably, the antioxidant is selected from one of antioxidant 1076, antioxidant 1010, and antioxidant 168;

[0019] The light stabilizer is selected from one or more of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, poly(1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidinyl) succinate, 2-hydroxy-4-n-octyloxybenzophenone and light stabilizer LQ-292;

[0020] The ultraviolet absorber is selected from N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 5-aminosalicylic acid, isooctyl salicylate, isooctyl p-methoxycinnamate, 2-hydroxy-4-n-octyloxybenzophenone, 2,2'-tetramethylenebis(3,1-benzoxazine-4-one), 2,8-dimethyl-4H,6H-benzo(1,2-d;5,4-d')bis(1,3)-oxazine-4,6-dione, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-benzoyloxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone , 2-hydroxy-5-chlorobenzophenone, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-5'-aminophenyl)benzotriazole, bisphenol A disalicylate, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazine-4-one, 2-(2'-hydroxy-3',5'-dimethylphenyl)benzotriazole, 2-(2'-methyl-4'-hydroxyphenyl)benzotriazole, bis-(2-methoxy-4-hydroxy-5-benzoylphenyl)methane, 2-(2'-hydroxy-5-methylphenyl)benzotriazole, 2-(2'-hydroxy-5-methylphenyl)-5-carboxylic acid butyl ester benzotriazole one or more;

[0021] The filler is selected from one or more of titanium dioxide, calcium carbonate, barium sulfate, silicon dioxide, silicon micropowder, calcium sulfate, and bismuth oxychloride;

[0022] The inorganic auxiliary agent is selected from zinc oxide, magnesium hydroxide, aluminum hydroxide or a combination of two or more thereof.

[0023] Furthermore, the thickness of the polyolefin layer is 50-200 μm, the thickness of the transition layer is 10-100 μm, and the thickness of the EVA layer is 30-200 μm.

[0024] The beneficial effects of the present invention are:

[0025] The packaging film of the invention is composited by a polyolefin layer, two transition layers and two EVA layers, and can improve the volume resistivity and water vapor permeability of the entire packaging film.

[0026] In the EVA layer and transition layer of the present invention, carbodiimide or carbodiimide compounds are added, and a silane coupling agent with an amino group is added to the polyolefin layer. In a hot and humid environment, the carbodiimide or carbodiimide compounds can react with the generated acetic acid or acidic substances to achieve the effect of deacidification; further, since the polar components in the polyolefin layer migrate to the EVA layer, the silane coupling agent with an amino group reaches the interface by utilizing the migration of the polar components, and the silane coupling agent with an amino group can react with the generated acetic acid or acidic substances under the action of the carbodiimide or carbodiimide compounds, thereby improving the adhesion at the interface, avoiding the risk of decreased interlayer bonding and extrusion and delamination of the polyolefin layer. In addition, when the polar components migrate, the silane coupling agent with an amino group can also enter the EVA layer and the transition layer, and react with acetic acid or acidic substances under the action of the carbodiimide or carbodiimide compounds, further improving the deacidification effect and the anti-PID effect.

[0027] The present invention uses two acid scavengers in synergy, and maintains the adhesion performance of the interface through the acid removal condensation reaction in a hot and humid environment, which can enhance the interface adhesion, especially the interface adhesion after hot and humid aging; and the present invention uses two acid scavengers in synergy, which can achieve better anti-PID effect;

[0028] The packaging film of the present invention adopts a reactive acid scavenger, which can not only obtain a better anti-PID effect, but also ensure that the interlayer peeling strength of the multi-layer packaging film does not decrease after long-term use, and does not affect the light transmittance. DETAILED DESCRIPTION

[0029] The technical solutions in the present invention will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The invention provides a multi-layer packaging adhesive film, comprising a polyolefin layer, two transition layers and two EVA layers, wherein the two transition layers are distributed on both sides of the polyolefin layer, and an EVA layer is arranged outside each transition layer, that is, the structure of the packaging adhesive film is specifically: EVA layer / transition layer / POE layer / transition layer / EVA layer; the main material of the polyolefin layer is a polyolefin material, and the main resin of the EVA layer is an EVA resin; by weight, the EVA layer further comprises 0.01-1% of an acid scavenger A and 0.1-5% of a catalyst relative to the weight of the acid scavenger A, the transition layer comprises 0.01-1% of an acid scavenger A and 0.1-5% of a catalyst relative to the weight of the acid scavenger A, and the polyolefin layer further comprises 0.01-1% of an acid scavenger B; the acid scavenger A is a carbodiimide or a carbodiimide compound; and the acid scavenger B is a silane coupling agent with an amino group.

[0031] Wherein, the polyolefin material is selected from one or a blend of two or more of HDPE, LDPE, LLDPE, ULDPE and POE.

[0032] The main polymer material of the transition layer is selected from EMA, maleic anhydride grafted polyethylene, maleic anhydride grafted POE, GMA grafted POE, GMA grafted EVA, GMA grafted EMA, GMA grafted EBA, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, silane coupling agent grafted modified POE, EAA or a blend of two or more thereof.

[0033] The acid scavenger A is selected from one or a combination of two or more of dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0034] The acid scavenger B is selected from one or a combination of two or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, anilinomethyltriethoxysilane and anilinomethyltrimethoxysilane.

[0035] The catalyst is selected from one or a combination of two or more of 4-N,N-dimethylpyridine, 1-hydroxybenzotriazole, 4-pyrrolidinylpyridine, 1-hydroxy-7-azabenzotriazole, N-hydroxyphthalimide and pentafluorophenol.

[0036] Furthermore, the polyolefin layer, transition layer, and EVA layer also include a crosslinking agent, an auxiliary crosslinking agent, and a silane coupling agent, respectively. Specifically, in the polyolefin layer, except for the above-mentioned deacidifier B, the weight percentages of the polyolefin material and other components are: 95%-98.5% of the polyolefin material, 0.5-1.5% of the crosslinking agent, 0.5-1.5% of the auxiliary crosslinking agent, and 0.1-1% of the silane coupling agent; in the EVA layer, except for the above-mentioned deacidifier A and the catalyst, the weight percentages of the EVA resin and other components are: 95%-98% of the EVA resin, 0.5-1.5% of the crosslinking agent, 0.5-1.5% of the auxiliary crosslinking agent, and 0.1-1% of the silane coupling agent; in the transition layer, except for the above-mentioned deacidifier A and the catalyst, the weight percentages of the main polymer material and other components are: 95%-98% of the main polymer material, 0.5-1.5% of the crosslinking agent, 0.5-1.5% of the auxiliary crosslinking agent, and 0.1-1% of the silane coupling agent.

[0037] The crosslinking agent is an organic peroxide crosslinking agent, and the organic peroxide crosslinking agent is selected from one or a combination of two or more of diisopropylbenzene peroxide, tert-butyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-amyl peroxy-2-ethylhexyl carbonate, di(2-ethyl)hexyl peroxydicarbonate, tert-amyl peroxy-2-ethylhexyl carbonate, benzoyl peroxide, and tert-butyl peroxy-2-ethylhexanoate;

[0038] The auxiliary cross-linking agent is selected from one or a combination of two or more of triallyl isocyanurate, 3-(trimethoxysilyl)propyl methacrylate, 3-vinylphenol, triallyl cyanurate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate;

[0039] The silane coupling agent is selected from one or a combination of two or more of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl triperoxide tert-butyl silane, vinyl triacetoxysilane, vinyl tri(β-methoxyethoxy)silane, and γ-(methacryloyloxy)propyl trimethoxysilane.

[0040] Furthermore, the polyolefin layer, transition layer and EVA layer respectively further include one or more of an antioxidant, a light stabilizer, an ultraviolet absorber, a filler and an inorganic additive.

[0041] The antioxidant is selected from one of antioxidant 1076, antioxidant 1010, and antioxidant 168;

[0042] The light stabilizer is selected from one or more of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, poly(1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidinyl) succinate, 2-hydroxy-4-n-octyloxybenzophenone and light stabilizer LQ-292;

[0043] The ultraviolet absorber is selected from N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 5-aminosalicylic acid, isooctyl salicylate, isooctyl p-methoxycinnamate, 2-hydroxy-4-n-octyloxybenzophenone, 2,2'-tetramethylenebis(3,1-benzoxazine-4-one), 2,8-dimethyl-4H,6H-benzo(1,2-d;5,4-d')bis(1,3)-oxazine-4,6-dione, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-benzoyloxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone , 2-hydroxy-5-chlorobenzophenone, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-5'-aminophenyl)benzotriazole, bisphenol A disalicylate, 2-(2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazine-4-one, 2-(2'-hydroxy-3',5'-dimethylphenyl)benzotriazole, 2-(2'-methyl-4'-hydroxyphenyl)benzotriazole, bis-(2-methoxy-4-hydroxy-5-benzoylphenyl)methane, 2-(2'-hydroxy-5-methylphenyl)benzotriazole, 2-(2'-hydroxy-5-methylphenyl)-5-carboxylic acid butyl ester benzotriazole one or more;

[0044] The filler is selected from one or more of titanium dioxide, calcium carbonate, barium sulfate, silicon dioxide, silicon micropowder, calcium sulfate, and bismuth oxychloride;

[0045] The inorganic auxiliary agent is selected from zinc oxide, magnesium hydroxide, aluminum hydroxide or a combination of two or more thereof.

[0046] The thickness of the polyolefin layer is 50-200 μm, the thickness of the transition layer is 10-100 μm, and the thickness of the EVA layer is 30-200 μm.

[0047] Example 1

[0048] Based on 100 parts by total weight, the raw materials for preparing the polyolefin layer include:

[0049] 97.2 parts of POE resin, 1 part of acid scavenger B: γ-aminopropyltrimethoxysilane, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl carbonate tert-butyl ester, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl ester, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0050] Based on 100 parts by weight, the raw materials for preparing the transition layer include:

[0051] 97.15 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 1 part of acid scavenger A: dicyclohexylcarbodiimide, 0.05 parts of catalyst 4-N,N-dimethylpyridine, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl carbonate tert-butyl ester, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl ester, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0052] Based on 100 parts by total weight, the raw materials for preparing the EVA layer include:

[0053] 97.15 parts of EVA resin, 1 part of acid scavenger A: dicyclohexylcarbodiimide, 0.05 parts of catalyst 4-N,N-dimethylpyridine, 0.3 parts of cross-linking agent tert-butyl peroxide-2-ethylhexyl carbonate, 0.3 parts of tert-amyl peroxide 2-ethylhexyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 770.

[0054] The raw materials used for the polyolefin layer, transition layer, and EVA layer are stirred respectively, placed at 35°C for 12 hours, and then put into a multi-layer co-extrusion process equipment. The extruder speed or melt pump speed is adjusted according to the thickness, and 5 layers of film material are extruded. After cooling and shaping, the desired multi-layer packaging film can be obtained. The packaging film includes a polyolefin layer, transition layers distributed on both sides of the polyolefin layer, and two EVA layers arranged outside the two transition layers; the thickness of the polyolefin layer is 120μm, the thickness of the two transition layers is 25μm, and the thickness of the two EVA layers is 150μm.

[0055] Example 2

[0056] Based on 100 parts by total weight, the raw materials for preparing the polyolefin layer include:

[0057] 97.9 parts of POE resin, 0.3 parts of acid scavenger B: γ-aminopropyltrimethoxysilane, 0.3 parts of crosslinking agent peroxy-2-ethylhexyl carbonate tert-butyl ester, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl ester, 0.5 parts of auxiliary crosslinking agent triallyl isocyanurate, 0.2 parts of auxiliary crosslinking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0058] Based on 100 parts by weight, the raw materials for preparing the transition layer include:

[0059] 97.15 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 1 part of acid scavenger A: dicyclohexylcarbodiimide, 0.05 parts of catalyst 4-N,N-dimethylpyridine, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl carbonate tert-butyl ester, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl ester, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0060] Based on 100 parts by total weight, the raw materials for preparing the EVA layer include:

[0061] 97.15 parts of EVA resin, 1 part of acid scavenger A: dicyclohexylcarbodiimide, 0.05 parts of catalyst 4-N,N-dimethylpyridine, 0.3 parts of cross-linking agent tert-butyl peroxide-2-ethylhexyl carbonate, 0.3 parts of tert-amyl peroxide 2-ethylhexyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 770.

[0062] The raw materials used for the polyolefin layer, transition layer, and EVA layer are stirred respectively, placed at 35°C for 12 hours, and then put into a multi-layer co-extrusion process equipment. The extruder speed or melt pump speed is adjusted according to the thickness, and 5 layers of film material are extruded. After cooling and shaping, the desired multi-layer packaging film can be obtained. The packaging film includes a polyolefin layer, transition layers distributed on both sides of the polyolefin layer, and two EVA layers arranged outside the two transition layers; the thickness of the polyolefin layer is 120μm, the thickness of the two transition layers is 25μm, and the thickness of the two EVA layers is 150μm.

[0063] Example 3

[0064] Based on 100 parts by total weight, the raw materials for preparing the polyolefin layer include:

[0065] 97.9 parts of POE resin, 0.3 parts of acid scavenger B: γ-aminopropyltrimethoxysilane, 0.3 parts of crosslinking agent peroxy-2-ethylhexyl carbonate tert-butyl ester, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl ester, 0.5 parts of auxiliary crosslinking agent triallyl isocyanurate, 0.2 parts of auxiliary crosslinking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0066] Based on 100 parts by weight, the raw materials for preparing the transition layer include:

[0067] 97.15 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 1 part of acid scavenger A: dicyclohexylcarbodiimide, 0.05 parts of catalyst 4-N,N-dimethylpyridine, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl carbonate tert-butyl ester, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl ester, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0068] Based on 100 parts by total weight, the raw materials for preparing the EVA layer include:

[0069] 97.67 parts of EVA resin, 0.5 parts of acid scavenger A: dicyclohexylcarbodiimide, 0.03 parts of catalyst 4-N,N-dimethylpyridine, 0.3 parts of cross-linking agent tert-butyl peroxide-2-ethylhexyl carbonate, 0.3 parts of tert-amyl peroxide 2-ethylhexyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 770.

[0070] The raw materials used for the polyolefin layer, transition layer, and EVA layer are stirred respectively, placed at 35°C for 12 hours, and then put into a multi-layer co-extrusion process equipment. The extruder speed or melt pump speed is adjusted according to the thickness, and 5 layers of film material are extruded. After cooling and shaping, the desired multi-layer packaging film can be obtained. The packaging film includes a polyolefin layer, transition layers distributed on both sides of the polyolefin layer, and two EVA layers arranged outside the two transition layers; the thickness of the polyolefin layer is 120μm, the thickness of the two transition layers is 25μm, and the thickness of the two EVA layers is 150μm.

[0071] Comparative Example 1

[0072] Based on 100 parts by total weight, the raw materials for preparing the polyolefin layer include:

[0073] 98.2 parts of POE resin, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl tert-butyl carbonate, 0.3 parts of peroxy-2-ethylhexyl tert-amyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0074] Based on 100 parts by weight, the raw materials for preparing the transition layer include:

[0075] 98.2 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl carbonate tert-butyl, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, 0.1 parts of light stabilizer 292.

[0076] Based on 100 parts by total weight, the raw materials for preparing the EVA layer include:

[0077] 98.2 parts of EVA resin, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl tert-butyl carbonate, 0.3 parts of peroxy-2-ethylhexyl tert-amyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 770.

[0078] The raw materials used for the polyolefin layer, transition layer, and EVA layer are stirred respectively, placed at 35°C for 12 hours, and then put into a multi-layer co-extrusion process equipment. The extruder speed or melt pump speed is adjusted according to the thickness, and 5 layers of film material are extruded. After cooling and shaping, the desired multi-layer packaging film can be obtained. The packaging film includes a polyolefin layer, transition layers distributed on both sides of the polyolefin layer, and two EVA layers arranged outside the two transition layers; the thickness of the polyolefin layer is 120μm, the thickness of the two transition layers is 25μm, and the thickness of the two EVA layers is 150μm.

[0079] Comparative Example 2

[0080] Based on 100 parts by total weight, the raw materials for preparing the polyolefin layer include:

[0081] 98.2 parts of POE resin, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl tert-butyl carbonate, 0.3 parts of peroxy-2-ethylhexyl tert-amyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0082] Based on 100 parts by weight, the raw materials for preparing the transition layer include:

[0083] 98.2 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl carbonate tert-butyl, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, 0.1 parts of light stabilizer 292.

[0084] Based on 100 parts by total weight, the raw materials for preparing the EVA layer include:

[0085] 97.2 parts of EVA resin, 1 part of magnesium hydroxide with a particle size of 0.5 μm, 0.3 parts of cross-linking agent tert-butyl peroxide-2-ethylhexyl carbonate, 0.3 parts of tert-amyl peroxide 2-ethylhexyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 770.

[0086] The raw materials used for the polyolefin layer, transition layer, and EVA layer are stirred respectively, placed at 35°C for 12 hours, and then put into a multi-layer co-extrusion process equipment. The extruder speed or melt pump speed is adjusted according to the thickness, and 5 layers of film material are extruded. After cooling and shaping, the desired multi-layer packaging film can be obtained. The packaging film includes a polyolefin layer, transition layers distributed on both sides of the polyolefin layer, and two EVA layers arranged outside the two transition layers; the thickness of the polyolefin layer is 120μm, the thickness of the two transition layers is 25μm, and the thickness of the two EVA layers is 150μm.

[0087] Comparative Example 3

[0088] Based on 100 parts by total weight, the raw materials for preparing the polyolefin layer include:

[0089] 97.92 parts of POE resin, 0.3 parts of acid scavenger B: γ-aminopropyltrimethoxysilane, 0.3 parts of crosslinking agent peroxy-2-ethylhexyl carbonate tert-butyl ester, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl ester, 0.5 parts of auxiliary crosslinking agent triallyl isocyanurate, 0.2 parts of auxiliary crosslinking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0090] Based on 100 parts by weight, the raw materials for preparing the transition layer include:

[0091] 98.2 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl carbonate tert-butyl, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, 0.1 parts of light stabilizer 292.

[0092] Based on 100 parts by total weight, the raw materials for preparing the EVA layer include:

[0093] 98.2 parts of EVA resin, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl tert-butyl carbonate, 0.3 parts of peroxy-2-ethylhexyl tert-amyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 770.

[0094] The raw materials used for the polyolefin layer, transition layer, and EVA layer are stirred respectively, placed at 35°C for 12 hours, and then put into a multi-layer co-extrusion process equipment. The extruder speed or melt pump speed is adjusted according to the thickness, and 5 layers of film material are extruded. After cooling and shaping, the desired multi-layer packaging film can be obtained. The packaging film includes a polyolefin layer, transition layers distributed on both sides of the polyolefin layer, and two EVA layers arranged outside the two transition layers; the thickness of the polyolefin layer is 120μm, the thickness of the two transition layers is 25μm, and the thickness of the two EVA layers is 150μm.

[0095] Comparative Example 4

[0096] Based on 100 parts by total weight, the raw materials for preparing the polyolefin layer include:

[0097] 98.2 parts of POE resin, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl tert-butyl carbonate, 0.3 parts of peroxy-2-ethylhexyl tert-amyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0098] Based on 100 parts by weight, the raw materials for preparing the transition layer include:

[0099] 97.15 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer, 1 part of acid scavenger A: dicyclohexylcarbodiimide, 0.05 parts of catalyst 4-N,N-dimethylpyridine, 0.3 parts of cross-linking agent peroxy-2-ethylhexyl carbonate tert-butyl ester, 0.3 parts of peroxy-2-ethylhexyl carbonate tert-amyl ester, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 292.

[0100] Based on 100 parts by total weight, the raw materials for preparing the EVA layer include:

[0101] 97.15 parts of EVA resin, 1 part of acid scavenger A: dicyclohexylcarbodiimide, 0.05 parts of catalyst 4-N,N-dimethylpyridine, 0.3 parts of cross-linking agent tert-butyl peroxide-2-ethylhexyl carbonate, 0.3 parts of tert-amyl peroxide 2-ethylhexyl carbonate, 0.5 parts of auxiliary cross-linking agent triallyl isocyanurate, 0.2 parts of auxiliary cross-linking agent trimethylolpropane trimethacrylate, 0.3 parts of silane coupling agent KH570, 0.1 parts of antioxidant 1076, and 0.1 parts of light stabilizer 770.

[0102] The raw materials used for the polyolefin layer, transition layer, and EVA layer are stirred respectively, placed at 35°C for 12 hours, and then put into a multi-layer co-extrusion process equipment. The extruder speed or melt pump speed is adjusted according to the thickness, and 5 layers of film material are extruded. After cooling and shaping, the desired multi-layer packaging film can be obtained. The packaging film includes a polyolefin layer, transition layers distributed on both sides of the polyolefin layer, and two EVA layers arranged outside the two transition layers; the thickness of the polyolefin layer is 120μm, the thickness of the two transition layers is 25μm, and the thickness of the two EVA layers is 150μm.

[0103] The light transmittance test of the packaging film samples of Examples 1-3 and Comparative Examples 1-4 was performed with reference to IEC62788-1-2.

[0104] The encapsulation film samples of Examples 1-3 and Comparative Examples 1-4 were prepared into photovoltaic modules, and the module power was tested, and the power attenuation of the module after PID192h and PID384h was tested.

[0105] To test the interlayer adhesion, the EVA layer, POE layer and transition layer of each embodiment and comparative example can be extruded separately and laminated according to the order of backplane / EVA layer / transition layer / POE layer / transition layer / EVA layer / backplane, and the interlayer peel strength between the EVA layer and the POE layer and the interlayer peel strength after PCT48h and DH2000h are tested.

[0106] The test results are shown in Table 1.

[0107]

[0108] From the data in Table 1, we can see that:

[0109] The light transmittance of Examples 1-3 is almost unchanged compared with that of Comparative Example 1 without adding an acid scavenger, indicating that the acid scavenger of the present invention does not affect the light transmittance at a certain ratio. After adding magnesium hydroxide acid scavenger to Comparative Example 2, the light transmittance is significantly reduced.

[0110] Interlayer peel strength comparison data, initial value is not much different.After PCT48h and DH2000, Comparative Example 1 has been significantly reduced, indicating that without adding the acid scavenger system of the present invention, after PCT and DH aging, the interlayer peel strength decreases. Comparative Example 2 also significantly reduces the peel strength after PCT48h and DH2000. And embodiment 1-3, after PCT48h and DH2000, the peel strength can still keep more than 70N / cm, this is because the acid scavenger of the present invention is a reactive acid scavenger, in a hot and humid environment, by the acid removal condensation reaction, the adhesion performance of the interface is maintained. Comparative Examples 3 and 4, only add the acid scavenger B or the acid scavenger A in the present invention respectively, after PCT48h and DH2000, the peel strength significantly reduces, indicating that the synergy of two kinds of acid scavengers can be realized to enhance the interfacial adhesion.

[0111] Comparing the PID power attenuation, the PID192h and PID384h of Examples 1-3 are all within 1.5%, which has a significant anti-PID attenuation effect. Comparative Example 1 does not add an acid scavenger, and its power attenuation after PID192h and PID384h can reach 3.12% and 4.52% respectively. Comparative Example 2 adds magnesium hydroxide acid scavenger to have a certain anti-PID effect, but the result is not as good as the embodiment of the present invention. Comparative Examples 3 and 4 only add acid scavenger B or acid scavenger A, and the anti-PID attenuation ability is reduced, and the attenuation after PID is larger. It shows that the two acid scavengers of the present invention can work together to achieve a better anti-PID effect.

[0112] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0113] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A multi-layer packaging film, characterized in that: The invention comprises a polyolefin layer, two transition layers and two EVA layers, wherein the two transition layers are distributed on both sides of the polyolefin layer, and an EVA layer is arranged on the outer side of each transition layer; the main material of the polyolefin layer is a polyolefin material, and the main resin of the EVA layer is an EVA resin; by weight, the EVA layer further comprises 0.01-1% of an acid scavenger A and 0.1-5% of a catalyst relative to the weight of the acid scavenger A, the transition layer comprises 0.01-1% of an acid scavenger A and 0.1-5% of a catalyst relative to the weight of the acid scavenger A, and the polyolefin layer further comprises 0.01-1% of an acid scavenger B; the acid scavenger A is a carbodiimide or a carbodiimide compound; and the acid scavenger B is a silane coupling agent with an amino group.

2. The multi-layer packaging film according to claim 1, characterized in that: The polyolefin material is selected from one or a blend of two or more of HDPE, LDPE, LLDPE, ULDPE and POE.

3. The multi-layer packaging film according to claim 1, characterized in that: The main polymer material of the transition layer is selected from EMA, maleic anhydride grafted polyethylene, maleic anhydride grafted POE, GMA grafted POE, GMA grafted EVA, GMA grafted EMA, GMA grafted EBA, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, silane coupling agent grafted modified POE, EAA or a blend of two or more thereof.

4. The multi-layer packaging film according to claim 1, characterized in that: The acid scavenger A is selected from one or a combination of two or more of dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

5. The multi-layer packaging film according to claim 1, characterized in that: The acid scavenger B is selected from one or a combination of two or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, anilinomethyltriethoxysilane and anilinomethyltrimethoxysilane.

6. The multi-layer packaging film according to claim 1, characterized in that: The catalyst is selected from one or a combination of two or more of 4-N,N-dimethylpyridine, 1-hydroxybenzotriazole, 4-pyrrolidinylpyridine, 1-hydroxy-7-azabenzotriazole, N-hydroxyphthalimide and pentafluorophenol.

7. The multi-layer packaging film according to claim 1, characterized in that: The polyolefin layer, transition layer and EVA layer further include a cross-linking agent, an auxiliary cross-linking agent and a silane coupling agent respectively.

8. The multi-layer packaging film according to claim 7, characterized in that: The crosslinking agent is an organic peroxide crosslinking agent, and the organic peroxide crosslinking agent is selected from one or a combination of two or more of diisopropylbenzene peroxide, tert-butyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-amyl peroxy-2-ethylhexyl carbonate, di(2-ethyl)hexyl peroxydicarbonate, tert-amyl peroxy-2-ethylhexyl carbonate, benzoyl peroxide, and tert-butyl peroxy-2-ethylhexanoate; The auxiliary cross-linking agent is selected from one or a combination of two or more of triallyl isocyanurate, 3-(trimethoxysilyl)propyl methacrylate, 3-vinylphenol, triallyl cyanurate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate; The silane coupling agent is selected from one or a combination of two or more of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl triperoxide tert-butyl silane, vinyl triacetoxysilane, vinyl tri(β-methoxyethoxy)silane, and γ-(methacryloyloxy)propyl trimethoxysilane.

9. A multi-layer packaging film according to claim 1 or 7, characterized in that: The polyolefin layer, transition layer and EVA layer further include one or more of antioxidants, light stabilizers, ultraviolet absorbers, fillers and inorganic additives.

10. The multi-layer packaging film according to claim 1, characterized in that: The thickness of the polyolefin layer is 50-200 μm, the thickness of the transition layer is 10-100 μm, and the thickness of the EVA layer is 30-200 μm.

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