An encapsulant film containing a lipophilic adsorbent, a method of manufacture, and a photovoltaic encapsulant film

Abstract

The application provides a packaging adhesive film containing an oleophilic adsorbent, a preparation method and a photovoltaic packaging adhesive film, and belongs to the technical field of solar cell packaging polymer materials. The packaging adhesive film containing the oleophilic adsorbent comprises the following components in parts by weight: 90-99 parts of a main resin, 0.5-2.5 parts of an initiator, 0.5-2.5 parts of a crosslinking agent, 0.05-5 parts of an adhesive, 0.01-5 parts of an antioxidant, 0.01-2 parts of an inorganic oleophilic adsorbent and 0.01-1 part of an organic oleophilic adsorbent. The packaging adhesive film has good bonding performance and high light transmittance, and simultaneously improves the problems of additive migration and slip. The adhesive film has good PID resistance and weather resistance under different hygrothermal aging conditions.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology for solar cell encapsulation, and more specifically, to an encapsulation film containing an oleophilic adsorbent, a preparation method thereof, and a photovoltaic encapsulation film. Background Technology

[0002] High-efficiency crystalline silicon solar cells are becoming increasingly mature, such as PERC cells (Passivated Emitter and Rear Cell), N-type TOPCON cells (Tunnel Oxide Passivated Contact), HJT bifacial cells (Heterojunction with Intrinsic Thin-film), and BC cells (Back Contact). These new cells possess multiple advantages, including high conversion efficiency, low degradation, and high bifaciality. Because the silver paste used in the modules is quite special, it is prone to potential difference under moisture, causing corrosion of the paste and significantly reducing the cell's power generation efficiency. Therefore, high-performance barrier materials are needed to encapsulate the cells.

[0003] Currently, most bifacial solar modules on the market use double-glass encapsulation, with a few using transparent backsheet encapsulation. The encapsulating films used in double-glass modules mainly include ethylene vinyl acetate copolymer (EVA) and ethylene octene copolymer (POE).

[0004] CN202211338866.4 discloses an EVA material, an encapsulating film, a preparation method thereof, and its application. The EVA material, based on a total weight of 100 parts, comprises the following components: 60-80 parts of a resin matrix, the resin matrix including EVA resin; 3-18 parts of an ion adsorbent; 3-18 parts of an anti-hydrolysis agent; and 1-5 parts of a dispersant.

[0005] CN202310918600.5 discloses an EVA masterbatch and raw material composition, encapsulating film and preparation method, application, and photovoltaic module. The raw material composition of the EVA masterbatch, based on a total weight of 100 parts, comprises the following components: 60-81 parts resin matrix, 3-15 parts ion adsorbent, 3-15 parts anti-hydrolysis agent, 1-10 parts antioxidant, 1-5 parts dispersant, 0.5-6 parts compatibilizer, 0.5-6 parts crosslinking agent, and 0.5-2 parts polymerization inhibitor; wherein the antioxidant is one or more of hindered phenolic compounds, phosphite compounds, and carbon alcohol ester compounds; and the polymerization inhibitor is a phenolic compound and / or a quinone compound.

[0006] CN202410242681.6 discloses an anti-PID EVA encapsulating film and its preparation method, relating to the field of photovoltaic materials. By weight, the anti-PID EVA encapsulating film uses 100 parts EVA resin, 0.5-1.5 parts crosslinking agent, 1.0-2.0 parts co-crosslinking agent, 2.0-4.0 parts adsorbent, 0.1-0.3 parts antioxidant, 0.1-0.3 parts light stabilizer, and 0.3-0.5 parts coupling agent as raw materials. It is prepared by extrusion and casting using a self-made adsorbent and optimized formulation design.

[0007] During long-term use, moisture can penetrate into the components through silicone and backsheet after encapsulation. When EVA material comes into contact with water, it decomposes, producing free-moving acetic acid. This free-moving acetic acid reacts with the alkali precipitated on the glass surface to form free-moving sodium ions. Under the influence of an external electric field, these sodium ions move towards the battery surface and accumulate on the anti-reflective layer, leading to the occurrence of PID (Potential Influence of Damping) phenomenon.

[0008] POE encapsulation film, developed using metallocene as a catalyst, is a novel polyolefin thermoplastic elastomer with a narrow relative molecular mass distribution, narrow comonomer distribution, and controllable structure. POE exhibits excellent water vapor barrier and ion barrier capabilities, with a water vapor permeability only about 1 / 8 that of EVA. Due to its stable molecular chain structure, it does not decompose and produce acidic substances during aging, demonstrating excellent anti-aging properties. It is the preferred material for high-efficiency, high-reliability photovoltaic module encapsulation films.

[0009] Currently, the preparation of encapsulating films requires indispensable additives, which are more or less polar. POE particles have difficulty directly absorbing these additives, and they are prone to precipitating out of the film during subsequent preparation processes. This can lead to two serious consequences: firstly, the additives do not fully participate in the reaction, resulting in low cross-linking of the film itself and affecting the performance of the prepared photovoltaic modules; secondly, the precipitated additives remain on the surface of the film, causing slippage during module preparation and increasing the difficulty of the module manufacturing process.

[0010] Currently, cyclodextrin is used as a loading agent to mitigate the problem of additive precipitation in POE compositions (CN116836650B). However, this material contains a large number of hydroxyl groups, which affects the crosslinking of the film material. Adding anti-slip masterbatch containing amorphous or ultra-low crystallinity polyolefin particles to the raw materials of POE encapsulation films (CN118853023B) can significantly improve the initial coefficient of friction of the film surface. However, the polyolefin particles used in this method have a large difference in melting point from POE material, making it difficult to achieve uniform plasticization during the casting process. Polyolefin films using a porous material loading system (CN116082984B) avoid the problem of additive precipitation from the polymer surface to some extent, but the adsorbent has weak specificity, and effective differentiation is not achieved during the mixing and sample preparation process. Designing new surface textures can increase the initial coefficient of friction of POE films (CN214188784U, CN211555902U, CN219610444U), but cannot fundamentally solve the problem of friction coefficient decay caused by rapid precipitation of additives during film storage.

[0011] In view of this, the present invention is hereby proposed. Summary of the Invention

[0012] To address the aforementioned deficiencies or improvement needs of existing technologies, the main objective of this invention is to provide an encapsulating film containing an oleophilic adsorbent, its preparation method, and a photovoltaic encapsulating film. The adsorbent in this invention does not contain active groups such as hydroxyl, carboxyl, amino, vinyl, or acrylic groups, and does not undergo cross-linking reactions with the main resin, thus making it safer. The encapsulating film of this invention, while possessing good adhesion and high light transmittance, also improves upon issues of additive migration and film slippage. Furthermore, the encapsulating film of this invention exhibits excellent weather resistance under humid and hot aging conditions.

[0013] To achieve the above objectives, according to one aspect of the present invention, the present invention first provides an encapsulating film containing an oleophilic adsorbent, comprising, by weight, the following components: 90-99 parts of main resin, 0.5-2.5 parts of initiator, 0.5-2.5 parts of crosslinking agent, 0.05-5 parts of adhesive, 0.01-5 parts of antioxidant, 0.01-2 parts of inorganic oleophilic adsorbent, and 0.01-1 parts of organic oleophilic adsorbent, wherein the inorganic and organic oleophilic adsorbents do not contain hydroxyl, carboxyl, amino, vinyl, or acrylic active groups.

[0014] Furthermore, the main resin includes ethylene-vinyl acetate copolymer (EVA) and ethylene-octene copolymer (POE).

[0015] Further, the main resin is an ethylene and vinyl acetate copolymer (EVA), wherein the vinyl acetate content is 20% to 32% (or 22%, 25%, 28%, 30%), or an ethylene and propylene copolymer, or an ethylene and butene copolymer, an ethylene and octene copolymer, or a terpolymer of ethylene, propylene and ethylene norbornene.

[0016] The main resin is preferably selected from one or more of the following: EVA resin with a vinyl acetate content of 28%, ethylene-α-butene copolymer, and ethylene-α-octene copolymer.

[0017] Furthermore, the main resin comprises 92-98 parts by weight, or 93, 95, or 97 parts.

[0018] Furthermore, the initiator is selected from one or more of cationic polymerization initiators, free radical polymerization initiators, anionic polymerization initiators, or coordination polymerization initiators.

[0019] Further, the initiator is selected from free radical polymerization initiators and may be any one or more of the following compounds: azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovalerate, azobisisobutyramidine hydrochloride, azobisisobutyramidazole hydrochloride, tert-butylperoxycarbonate isopropyl ester, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, and tert-pentyl peroxycarbonate.

[0020] Further, the initiator is present in the form of 0.8-2.2 parts by weight, or 1.0, 1.3, 1.5, 1.8, or 2.0 parts by weight.

[0021] Furthermore, the crosslinking agent contains two or more functional groups, such as organic diacids, polyols, etc., or substances containing multiple unsaturated double bonds, which generate chemical bonds between linear molecules, linking the linear molecules together to form a network structure, thereby improving the strength and elasticity of the polymer material. The crosslinking agent can be added together with the monomer, and crosslinking occurs after the polycondensation (or polymerization) reaches a certain degree, making the product an insoluble crosslinked polymer; alternatively, a certain number of functional groups (or double bonds) can be retained in the linear molecules before adding the desired substances for crosslinking.

[0022] The crosslinking agent is preferably a substance containing multiple unsaturated double bonds, and may be one of the following compounds: triallyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, propionylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propionylated glycerol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, bis(trimethylolpropane tetraacrylate), bis(trimethylolpropane tetramethacrylate), propionylated pentaerythritol tetraacrylate, 2,4,6-tris(allyloxy)-1,3,5-triazine, tricyclodecanediethanol diacrylate, propionylated neopentyl glycol diacrylate, bisphenol A Ethoxylated diacrylate, ethoxylated bisphenol A dimethacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and polyethylene glycol dimethacrylate are all selected from one or more of these.

[0023] Further, the crosslinking agent is present in the form of 0.8-2.2 parts by weight, or 1.0, 1.3, 1.5, 1.8, or 2.0 parts by weight.

[0024] Furthermore, the adhesive is a substance with two different functional groups, used to improve the interfacial interaction between the photovoltaic film and the photovoltaic glass or cell, thereby greatly improving the bonding performance of the composite material.

[0025] Furthermore, the adhesive is preferably a silane coupling agent, which may be any one or more of the following compounds: vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriperoxytert-butylsilane, vinyltriacetoxysilane, vinyltri(β-methoxyethoxy)silane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidyl etheroxypropyltrimethylsilane, and 3-aminopropyltrimethylsilane.

[0026] Further, the adhesive is present in parts by weight of 0.1-4.8, or 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or 4.5.

[0027] Furthermore, the antioxidant is used to prevent polymer materials from losing strength and toughness due to oxidative degradation or ultraviolet degradation. Based on their mechanism of action, antioxidants are classified into several categories, including free radical absorbing antioxidants, oxygen scavenging antioxidants, metal ion chelating and stabilizing antioxidants, singlet oxygen capturing antioxidants, and ultraviolet absorbers.

[0028] Further, the antioxidant is preferably selected from the following compounds: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(octadecyl)thiodipropionate, pentaerythritol tetra(3-laurylthio) Propionate), didodecyl thiodipropionate, nonyl-N-(nonylphenyl)aniline, 4,6-di(octylthiomethyl)o-cresol, bis-2,2,6,6-tetramethylpiperidinol sebacate, 2,4-dichloro-6-(4-morpholino)-1,3,5-triazine, bis-1-decyloxy-2,2,6,6-tetramethylpiperidin-4-ol sebacate, succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1 Polymers of piperidinol, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate / methyl-1,2,2,6,6-pentamethyl-4-piperidinyl sebacate complexes, or polymers of succinic acid and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol), 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenethyl)-4-(1,1,3,3-tetramethylbutyl) The following are some of the following: phenol, 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-octoxyphenol, 2-(2-hydroxy-5-methylphenyl)benzotriazole, N,N'-dicyclohexylcarbodiimide, N,N-di(2,6-diisopropylphenyl)carbodiimide, N,N'-diisopropylcarbodiimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, etc.

[0029] Further, the antioxidant is present in parts by weight of 0.1-4.8, or 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or 4.5.

[0030] Furthermore, the inorganic oleophilic adsorbent is an inorganic porous material that, after surface treatment, can effectively adsorb organic materials.

[0031] Furthermore, the inorganic oleophilic adsorbent includes porous alumina, microporous glass, porous ceramics, fumed silica, C18 modified silica gel, and molecular sieves. Porous alumina (also known as activated alumina) is obtained by dehydrating aluminum hydroxide. Microporous glass is alkali metal borosilicate glass that has been treated with acid under certain conditions to obtain glass with different pore sizes. The pore-forming method for porous ceramics involves adding a certain amount of combustible material (such as charcoal powder or rice husks) to the feedstock, which creates pores between the main materials during low-temperature firing; or forming a certain amount of liquid phase at high temperature, which shrinks and creates pores while the main materials are bonded together.

[0032] Furthermore, the inorganic oleophilic adsorbent is preferably selected from one or two of fumed silica, C18 modified silica gel, molecular sieve, and porous ceramics.

[0033] Furthermore, the inorganic oleophilic adsorbent can be in the form of 0.05-1.9 parts by weight, or 0.1, 0.2, 0.3, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.5, or 1.8 parts.

[0034] Furthermore, the organic lipophilic adsorbent enables the active ingredient to adhere to its particle surface, transforming the liquid trace compound additive into a solid compound, which facilitates uniform mixing. It is a solid substance capable of effectively adsorbing certain components from gas, liquid, and solid-liquid mixtures. It possesses a large specific surface area, suitable pore structure and surface structure; it has a strong adsorption capacity for adsorbed substances; and generally does not chemically react with the adsorbed substances or the medium.

[0035] Furthermore, the organic lipophilic adsorbent is cucurbituril. Cucurbituril, also known as guar urea, is a special cyclic molecule composed of multiple interconnected urea groups (urea groups). The molecular structure of cucurbituril forms a hollow castor bean-like space, in which some molecules or ions can be encapsulated. The discovered cucurbituril homologues include Q[5], Q[6], Q[7], Q[8], Q

[10] , etc., and their molecular formulas and structural formulas are shown below:

[0036]

[0037] Furthermore, the organic lipophilic adsorbent is preferably one or more of six-membered cucurbitacin, eight-membered cucurbitacin, and ten-membered cucurbitacin.

[0038] Furthermore, the weight percentage of the organic lipophilic adsorbent can be 0.05-0.95 parts, or 0.1 parts, 0.2 parts, 0.3 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, or 0.9 parts.

[0039] According to another aspect of the present invention, the present invention provides a method for preparing an encapsulating film containing an oleophilic adsorbent, comprising the following steps:

[0040] Step C1: Mix the organic lipophilic adsorbent with the initiator to obtain mixture D1.

[0041] Step C2: Mix the inorganic oleophilic adsorbent with the crosslinking agent, binder, and antioxidant to obtain mixture D2.

[0042] Step C3: Thoroughly mix the main resin, mixture D1, and mixture D2 to obtain mixture D3.

[0043] Step C4: Mixture D3 is used as one of the components to obtain a film material by melt extrusion casting.

[0044] Further, in step C1, the mass ratio of the organic lipophilic adsorbent to the initiator is 1:10 to 1:1, or 1:9, or 1:8, or 1:7, or 1:5, or 1:4, or 1:2.

[0045] Further, the temperature of the mixture in step C1 is 1°C to 40°C, or 5°C, or 10°C, or 15°C, or 20°C, or 25°C, or 30°C, or 35°C.

[0046] Furthermore, the material mixing time in step C1 is 2 to 48 hours, or 4 hours, or 8 hours, or 10 hours, or 20 hours, or 30 hours, or 40 hours.

[0047] Furthermore, in step C2, the mass ratio of the inorganic oleophilic adsorbent to the total mass of the crosslinking agent, binder, and antioxidant is 1:10 to 1:2, or 1:9, or 1:8, or 1:7, or 1:5, or 1:4.

[0048] Further, the temperature of the mixture in step C2 is 1°C to 40°C, or 5°C, or 10°C, or 15°C, or 20°C, or 25°C, or 30°C, or 35°C.

[0049] Furthermore, the material mixing time in step C2 is 2 to 48 hours, or 4 hours, or 8 hours, or 10 hours, or 20 hours, or 30 hours, or 40 hours.

[0050] Further, the temperature of the mixture in step C3 is 1°C to 40°C, or 5°C, or 10°C, or 15°C, or 20°C, or 25°C, or 30°C, or 35°C.

[0051] Furthermore, the material mixing time in step C3 is 2 to 48 hours, or 4 hours, or 8 hours, or 10 hours, or 20 hours, or 30 hours, or 40 hours.

[0052] Furthermore, the melting temperature of the material in step C4 is 65°C to 110°C, or 70°C, or 80°C, or 90°C, or 100°C.

[0053] Furthermore, the extrusion line speed in step C4 is from 1 m / min to 50 m / min, or 5 m / min, or 10 m / min, or 15 m / min, or 20 m / min, or 25 m / min, or 30 m / min, or 35 m / min, or 40 m / min, or 55 m / min.

[0054] Furthermore, the present invention also provides a photovoltaic encapsulation film, which is a single-layer structure or a multi-layer structure, and at least one layer of the encapsulation film comprises the above-mentioned organic oleophilic adsorbent and inorganic oleophilic adsorbent.

[0055] The present invention provides a photovoltaic encapsulating film, wherein at least one layer of the photovoltaic encapsulating film is prepared by the preparation method described in any of the above embodiments.

[0056] The encapsulating film of this invention employs two oleophilic adsorbents, each mixed with different additives, to effectively avoid reactions between different additives in the same adsorbent. The encapsulating film of this invention improves the problem of additive migration and exhibits good anti-slip performance at room temperature. Furthermore, the encapsulating film after heat lamination has good adhesion, good light transmittance, and good weather resistance under humid heat aging conditions. Attached Figure Description

[0057] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 This is a double-layer EP structured adhesive film according to an embodiment of the present invention. The double-layer EP structured adhesive film includes a POE layer adhesive film 20 and an EVA layer adhesive film 21. Detailed Implementation

[0059] To better understand the structure of the present invention and the functional features and advantages it can achieve, the following detailed description will be provided in conjunction with preferred embodiments of the present invention.

[0060] It should be noted that the illustrative embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. The embodiments and features in the embodiments of this application can be combined with each other. The present invention will be described in detail below through specific examples and embodiments. All raw materials used in the following embodiments are commercially available products.

[0061] Example 1

[0062] An encapsulating film containing an oleophilic adsorbent.

[0063] POE material containing adsorbents: 95.1 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, 0.4 parts organic lipophilic adsorbent, and 1.5 parts inorganic lipophilic adsorbent. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate (i.e., triallyl isocyanurate) and ethoxylated trimethylolpropane triacrylate (i.e., glyceryl ethoxylate) in a mass ratio of 1:1, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a mass ratio of 1:2, the inorganic lipophilic adsorbent is hydrophobic fumed silica with a particle size of 20 micrometers, and the organic lipophilic adsorbent is octavalent cucurbitaurea.

[0064] Mixing of POE materials containing adsorbents: Mix the organic lipophilic adsorbent with the initiator and stir at 20°C for 30 minutes to obtain mixture 1A; mix the inorganic lipophilic adsorbent with the crosslinking agent, binder, and antioxidant and stir at 20°C for 30 minutes to obtain mixture 1B; mix the POE main resin, 1A, and 1B thoroughly and stir at 20°C for 30 minutes to obtain mixture 1C.

[0065] Film casting: The above mixture 1C is placed in a material bucket, melted and plasticized by an extruder, and then flows into a distributor to obtain a single-layer POE film with a thickness of 500μm. After embossing, traction, and winding, a roll of encapsulation film is obtained.

[0066] Example 2

[0067] An encapsulating film containing an oleophilic adsorbent.

[0068] POE material containing adsorbents: 95.1 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, 0.4 parts organic lipophilic adsorbent, and 1.5 parts inorganic lipophilic adsorbent. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio, the inorganic lipophilic adsorbent is hydrophobic fumed silica with a particle size of 20 micrometers, and the organic lipophilic adsorbent is octavalent cucurbita.

[0069] EVA material without adsorbent: 97.35 parts main resin, 0.8 parts initiator, 1.2 parts crosslinking agent, 0.15 parts binder, and 0.5 parts antioxidant. The main resin is Formosa Plastics EVA resin, the initiator is 2,5-dimethyl-2,5-di(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanurate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, and the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio.

[0070] Mixing of POE materials containing adsorbents: Mix the organic lipophilic adsorbent with the initiator and stir at 20°C for 30 minutes to obtain mixture 2A. Mix the inorganic lipophilic adsorbent with the crosslinking agent, binder, and antioxidant and stir at 20°C for 30 minutes to obtain mixture 2B. Thoroughly mix the POE main resin, 2A, and 2B and stir at 20°C for 30 minutes to obtain mixture 2C.

[0071] EVA material mixing without adsorbent: EVA main resin, initiator, crosslinking agent, binder and antioxidant are mixed and stirred at 20°C for 30 minutes to obtain mixture 2D.

[0072] Film casting: The above mixtures 2C and 2D are placed in different material containers, melted and plasticized in the same extruder, and then flowed into the same distributor to obtain a double-layer EVA / POE film. The EVA layer and POE layer have a thickness ratio of 1:1 and are 250μm each. After embossing, traction, and winding, a roll of encapsulation film is obtained. Figure 1 As shown, the double-layer EVA / POE film includes a POE layer film 20 and an EVA layer film 21.

[0073] Example 3

[0074] An encapsulating film containing an oleophilic adsorbent.

[0075] POE material containing adsorbents: 95.1 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, 0.4 parts organic lipophilic adsorbent, and 1.5 parts inorganic lipophilic adsorbent. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio, the inorganic lipophilic adsorbent is hydrophobic fumed silica with a particle size of 20 micrometers, and the organic lipophilic adsorbent is cucurbita.

[0076] The following process is the same as in Example 1.

[0077] Example 4

[0078] An encapsulating film containing an oleophilic adsorbent.

[0079] POE material containing adsorbents: 95.1 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, 0.4 parts organic lipophilic adsorbent, and 1.5 parts inorganic lipophilic adsorbent. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanurate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio, the inorganic lipophilic adsorbent is a molecular sieve, and the organic lipophilic adsorbent is octavalent cucurbitaurea.

[0080] The following process is the same as in Example 1.

[0081] Example 5

[0082] An encapsulating film containing an oleophilic adsorbent.

[0083] POE material containing adsorbents: 95.1 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, 0.4 parts organic lipophilic adsorbent, and 1.5 parts inorganic lipophilic adsorbent. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanurate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and dioctadecyl thiodipropionate in a 1:2 mass ratio, the inorganic lipophilic adsorbent is C18 modified silica gel, and the organic lipophilic adsorbent is hepta-cucurbitaurea.

[0084] The following process is the same as in Example 1.

[0085] Example 6

[0086] An encapsulating film containing an oleophilic adsorbent.

[0087] EVA material containing adsorbents: 95.9 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, 0.2 parts organic lipophilic adsorbent, and 0.9 parts inorganic lipophilic adsorbent. The main resin is Formosa Plastics EVA resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio, the inorganic lipophilic adsorbent is hydrophobic fumed silica with a particle size of 20 micrometers, and the organic lipophilic adsorbent is octavalent cucurbita.

[0088] Mixing of EVA materials containing adsorbents: Mix the organic lipophilic adsorbent with the initiator and stir at 20°C for 30 minutes to obtain mixture 6A; mix the inorganic lipophilic adsorbent with the crosslinking agent, binder, and antioxidant and stir at 20°C for 30 minutes to obtain mixture 6B; mix the EVA main resin, 6A, and 6B thoroughly and stir at 20°C for 30 minutes to obtain mixture 6C.

[0089] Film casting: The above mixture 6C is placed in a material bucket, melted and plasticized by an extruder, and then flows into a distributor to obtain a single-layer EVA film with a thickness of 500μm. After embossing, traction, and winding, a roll of encapsulation film is obtained.

[0090] Example 7

[0091] An encapsulating film containing an oleophilic adsorbent.

[0092] EVA material containing adsorbents: 95.9 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, 0.2 parts organic lipophilic adsorbent, and 0.9 parts inorganic lipophilic adsorbent. The main resin is Formosa Plastics EVA resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio, the inorganic lipophilic adsorbent is C18 modified silica gel, and the organic lipophilic adsorbent is cucurbita.

[0093] The following process is the same as in Example 6.

[0094] Example 8

[0095] An encapsulating film containing an oleophilic adsorbent.

[0096] POE material containing adsorbents: 95.1 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, 0.4 parts organic lipophilic adsorbent, and 1.5 parts inorganic lipophilic adsorbent. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester and dioctadecyl thiodipropionate in a 1:2 mass ratio, the inorganic lipophilic adsorbent is hydrophobic fumed silica with a particle size of 20 micrometers, and the organic lipophilic adsorbent is octavalent cucurbita.

[0097] EVA material containing adsorbents: 96.25 parts main resin, 0.8 parts initiator, 1.2 parts crosslinking agent, 0.15 parts binder, 0.5 parts antioxidant, 0.2 parts organic lipophilic adsorbent, and 0.9 parts inorganic lipophilic adsorbent. The main resin is Formosa Plastics EVA resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio, the inorganic lipophilic adsorbent is C18 modified silica gel, and the organic lipophilic adsorbent is cucurbita.

[0098] Mixing of POE materials containing adsorbents: Mix the organic lipophilic adsorbent with the initiator and stir at 20°C for 30 minutes to obtain mixture 8A; mix the inorganic lipophilic adsorbent with the crosslinking agent, binder, and antioxidant and stir at 20°C for 30 minutes to obtain mixture 8B; mix the POE main resin, 8A, and 8B thoroughly and stir at 20°C for 30 minutes to obtain mixture 8C.

[0099] Mixing of EVA materials containing adsorbents: Mix the organic lipophilic adsorbent with the initiator and stir at 20°C for 30 minutes to obtain mixture 8D; mix the inorganic lipophilic adsorbent with the crosslinking agent, binder, and antioxidant and stir at 20°C for 30 minutes to obtain mixture 8E; mix the EVA main resin, 8D, and 8E thoroughly and stir at 20°C for 30 minutes to obtain mixture 8F.

[0100] The following process is similar to that in Example 2.

[0101] Comparative Example 1

[0102] POE material without adsorbent: 97 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, and 0.5 parts antioxidant. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, and the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio.

[0103] Mixing of POE materials without adsorbents: Mix the main resin with initiator, crosslinking agent, binder and antioxidant, and stir at 20°C for 60 minutes to obtain a mixture.

[0104] Film casting: The above mixture is placed in a material bucket, melted and plasticized by an extruder, and then flows into a distributor to obtain a single-layer POE film with a thickness of 500μm. After embossing, traction, and winding, a roll of encapsulation film is obtained.

[0105] Comparative Example 2

[0106] The composition includes 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, and 1.5 parts inorganic lipophilic adsorbent. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio, and the inorganic lipophilic adsorbent is hydrophobic fumed silica with a particle size of 20 micrometers.

[0107] Mixing of POE materials containing inorganic adsorbents: The main resin is mixed with initiator, crosslinking agent, binder, adsorbent and antioxidant, and stirred at 20°C for 60 minutes to obtain a mixture.

[0108] The following process is similar to that of Comparative Example 1.

[0109] Comparative Example 3

[0110] POE material containing organic adsorbent: 96.6 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, 0.5 parts antioxidant, and 0.4 parts organic lipophilic adsorbent. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanurate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio, and the organic lipophilic adsorbent is octavalent cucurbitaurea.

[0111] Mixing of POE materials containing organic adsorbents: The main resin is mixed with initiator, crosslinking agent, binder, adsorbent and antioxidant, and stirred at 20°C for 60 minutes to obtain a mixture.

[0112] The following process is similar to that of Comparative Example 1.

[0113] Comparative Example 4

[0114] EVA material without adsorbent: 97.35 parts main resin, 0.8 parts initiator, 1.2 parts crosslinking agent, 0.15 parts binder, and 0.5 parts antioxidant. The main resin is Formosa Plastics EVA resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanurate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, and the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio.

[0115] Mixing of EVA materials without adsorbents: Mix EVA main resin, initiator, crosslinking agent, binder, antioxidant, etc., and stir at 20°C for 30 minutes to obtain a mixture;

[0116] The following process is similar to that of Comparative Example 1.

[0117] Comparative Example 5

[0118] POE material without adsorbent: 97 parts main resin, 0.8 parts initiator, 1.5 parts crosslinking agent, 0.2 parts binder, and 0.5 parts antioxidant. The main resin is Mitsui POE resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, and the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio.

[0119] EVA material without adsorbent: 97.35 parts main resin, 0.8 parts initiator, 1.2 parts crosslinking agent, 0.15 parts binder, and 0.5 parts antioxidant. The main resin is Formosa Plastics EVA resin, the initiator is 2,5-dimethyl-2,5-(di-tert-butylperoxy)hexane, the crosslinking agent is a compound of triallyl isocyanurate and ethoxylated trimethylolpropane triacrylate in a 1:1 mass ratio, the binder is vinyltriethoxysilane, and the antioxidant is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dioctadecyl thiodipropionate in a 1:2 mass ratio.

[0120] The following process is similar to that of Comparative Example 1.

[0121] Table 1. Component ratios for Examples 1-8

[0122]

[0123] Table 2. Component ratios of Comparative Examples 1-5

[0124]

[0125] Performance testing of the samples.

[0126] Peel force test:

[0127] (1) Prepare two pieces of raw film, one piece of glass and one flexible backing plate, each with a size of 100mm×150mm.

[0128] (2) Stack the glass / adhesive film (two pieces) / flexible backing in sequence, place them in a vacuum laminator, heat and vacuum laminate, and the adhesive film in the laminated sample should be free of air bubbles. Prepare 3 samples.

[0129] (3) Cut the flexible backing / film layer into samples with a width of 10mm±0.5mm every 10mm in the width direction for testing the peel force between the film and the glass.

[0130] (4) According to the test method of GB / T2790-1995, the peel force between the glass and the film is measured on a tensile testing machine at a tensile speed of 100 mm / min ± 10 mm / min. The arithmetic mean of 3 samples is taken to obtain the peel strength, accurate to 0.1 N / cm.

[0131] (5) Among them, for double-layer EVA / POE film or multi-layer film, measure the POE layer.

[0132] Determination of static friction coefficient of adhesive film: Select adhesive film without lamination, including double-layer EVA / POE adhesive film or multi-layer adhesive film, measure the POE layer, and the test procedure refers to GB / T 10006-1988.

[0133] Transmittance test of the film: Select the laminated film, test the range from 380 to 1100 nm, and refer to ASTM D1003-13 for the test procedure.

[0134] Aging performance evaluation of the adhesive film:

[0135] (1) Prepare two pieces of raw film, one piece of glass and one flexible backing plate, each with a size of 100mm×150mm.

[0136] (2) Stack the glass / adhesive film (two pieces) / flexible backing in sequence, place them in a vacuum laminator, heat and vacuum laminate, and the adhesive film in the laminated sample should be free of air bubbles. Prepare 3 samples.

[0137] (3) Seal the edges of the component with water-blocking cloth, and then conduct a DH aging test (i.e., damp heat aging test, temperature is 85℃, humidity is 85%RH). After 1000 hours, take it out and conduct a peel force test according to the standard of GB / T2790-1995, unit N / cm.

[0138] (4) Among them, for double-layer EVA / POE film or multi-layer film, measure the POE layer.

[0139] Table 3 Performance tests of Examples 1-8 and Comparative Examples 1-5

[0140]

[0141] Data Results Analysis

[0142] In the above experiments, Example 1 was a pure POE membrane with added organic and inorganic adsorbents, and the mixing process was a step-by-step mixing method; Example 2 was a double-layer EVA / POE membrane, wherein the POE layer used the same formulation and process as in Example 1; Examples 3 to 5 were pure POE membranes with added different types of organic and inorganic adsorbents; Examples 6 and 7 were pure EVA membranes with added organic and inorganic adsorbents; Example 8 was a double-layer EVA / POE membrane, wherein both the POE and EVA layers had added organic and inorganic adsorbents. Comparative Example 1 was a pure POE membrane without adsorbents, mixed in a one-step mixing method; Comparative Example 2 was a pure POE membrane containing only inorganic adsorbents, mixed in a one-step mixing method; Comparative Example 3 was a pure POE membrane containing only organic adsorbents, mixed in a one-step mixing method; Comparative Example 4 was a double-layer EVA / POE membrane, wherein the POE layer used the same formulation and process as in Comparative Example 1. Comparative Example 5 is a double-layer EVA / POE film, in which no adsorbent is added to either the POE layer or the EVA layer.

[0143] The test results clearly demonstrate the advantages of using dual adsorbents and distributed mixing. Examples 8, 6, and 2 exhibited high coefficients of friction, indicating that the POE / EVA bilayer film with added adsorbents and the EVA film with added adsorbents showed the best anti-slip performance. The remaining examples show that the technical route of this invention is also effective for pure POE films, and the addition of both organic and inorganic adsorbents also resulted in high coefficients of friction. Comparative Examples 1, 2, 3, and 4 show that without adding an adsorbent, or with only one adsorbent, a one-step mixing process is unlikely to effectively improve the anti-slip performance of the film. Comparative Example 5 shows that the anti-slip performance of the POE / EVA bilayer film without added adsorbents also needs improvement. Furthermore, the transmittance of the various films in the comparative examples and examples (380-1100 nm), the initial adhesion between the film and glass, and the adhesion between the film and glass after DH1000 aging data indicate that adding dual adsorbents has little impact on the conventional performance of the film.

[0144] Those skilled in the art can refer to the content of this document and appropriately improve the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and fall within the scope of this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to implement and apply the technology of this invention.

Claims

1. An encapsulating adhesive film containing oleophilic adsorbent, comprising by weight parts: 90-99 parts of main resin, 0.5-2.5 parts of initiator, 0.5-2.5 parts of crosslinking agent, 0.05-5 parts of adhesive, 0.01-5 parts of antioxidant, 0.01-2 parts of inorganic oleophilic adsorbent, 0.01-1 parts of organic oleophilic adsorbent, wherein, The inorganic lipophilic adsorbent and the organic lipophilic adsorbent do not contain hydroxyl, carboxyl, amine, vinyl, acrylic active groups, The adhesive is selected from silane coupling agents, The organic lipophilic adsorbent is cucurbituril, The preparation method of the encapsulation adhesive film comprises the following steps: Step C1: mixing the organic lipophilic adsorbent with the initiator to obtain a mixture D1; Step C2: mixing the inorganic lipophilic adsorbent with the crosslinking agent, the adhesive, and the antioxidant to obtain a mixture D2; Step C3: fully mixing the main resin, the mixture D1, and the mixture D2 to obtain a mixture D3; Step C4: melt-extruding and casting the mixture D3 as one of the components to obtain a film-shaped material.

2. The encapsulation film according to claim 1, wherein, The main resin comprises ethylene-vinyl acetate copolymer and ethylene-octene copolymer.

3. The encapsulation film according to claim 1, wherein, The initiator is selected from one or two or more of cationic polymerization initiators, free radical polymerization initiators, anionic polymerization initiators, or coordination polymerization initiators.

4. The encapsulation film of claim 1, wherein, The crosslinking agent contains two or more functional groups.

5. The encapsulation film of claim 1, wherein, The silane coupling agent is selected from any one or more of vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriperoxy-t-butylsilane, vinyltriacetoxysilane, vinyltris(β-methoxyethoxy)silane, γ-aminopropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3-aminopropyltrimethylsilane.

6. The encapsulation film of claim 1, wherein, The antioxidant is selected from any one or more of radical absorption antioxidants, oxygen scavenging antioxidants, metal ion chelating stable antioxidants, and ultraviolet absorbers.

7. The encapsulation film according to claim 6, wherein, The antioxidant is selected from singlet oxygen trapping antioxidants.

8. The preparation method of the encapsulation adhesive film according to any one of claims 1-7, comprising the following steps: Step C1: mixing the organic lipophilic adsorbent with the initiator to obtain a mixture D1; Step C2: mixing the inorganic lipophilic adsorbent with the crosslinking agent, the adhesive, and the antioxidant to obtain a mixture D2; Step C3: fully mixing the main resin, the mixture D1, and the mixture D2 to obtain a mixture D3; Step C4: melt-extruding and casting the mixture D3 as one of the components to obtain a film-shaped material.

9. The method for preparing the encapsulating film according to claim 8, characterized in that, The mass ratio of the organic lipophilic adsorbent to the initiator in step C1 is 1:10 to 1:1, the temperature of the mixed materials is 1°C to 40°C, and the mixing time of the materials is 2 hours to 48 hours.

10. The method for preparing the encapsulating film according to claim 8, characterized in that, The mass ratio of the inorganic lipophilic adsorbent to the sum of the mass of the crosslinking agent, the adhesive, and the antioxidant in step C2 is 1:10 to 1:2, the temperature of the mixed materials is 1°C to 40°C, and the mixing time of the materials is 2 hours to 48 hours.

11. A photovoltaic encapsulation adhesive film, which is a single-layer structure or a multi-layer structure, and at least one layer of the photovoltaic encapsulation adhesive film is the encapsulation adhesive film according to any one of claims 1-7.

12. A photovoltaic encapsulation adhesive film, which is a single-layer structure or a multi-layer structure, and at least one layer of the photovoltaic encapsulation adhesive film is the encapsulation adhesive film prepared by the preparation method according to any one of claims 8-10.

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