Packaging adhesive film and packaging device

Abstract

The invention discloses a packaging adhesive film and a packaging device. The packaging adhesive film comprises a first adhesive film layer and a second adhesive film layer which are sequentially stacked, wherein the first adhesive film layer comprises first matrix resin and a nanometer material, the second adhesive film layer comprises second matrix resin and an acid binding agent, the color difference value L of the nanometer material is 10-50, and the tan delta of the first adhesive film layer is larger than 0.2 at the temperature ranging from-20 DEG C to 50 DEG C. The packaging adhesive film has excellent optical performance, and the attractiveness and functional characteristics of the packaging adhesive film can be maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesive films, and in particular to a packaging adhesive film and a packaging device. Background Art

[0002] PVB film is widely used in laminated glass, solar photovoltaic modules and other fields due to its excellent sound insulation, physical protection and recyclability. PVB film can be made into colorful films. Colorful PVB film is usually made by pre-mixing polyvinyl butyral (PVB) resin and pigment, plasticizing with plasticizer and extruding. The plasticizer in PVB film migrates over time and may corrode adjacent sensitive components, such as electronic components. Currently, PVB film is mostly laminated with other film layers such as EVA (ethylene-vinyl acetate copolymer) or POE (polyolefin elastomer) to prevent the plasticizer in the PVB film from migrating and corroding adjacent sensitive components. However, when PVB film is laminated with EVA film or POE film, the EVA film or POE film will release corrosive compounds (such as acidic by-products) during production or use. The residues of these acidic by-products will not only affect the transparency of the film, but also affect the color stability of the PVB film, causing the color of the colored PVB film to fade or even fade, affecting the appearance and functionality of the product. Summary of the Invention

[0003] The main purpose of the present invention is to provide a packaging film and a packaging device to solve the problem of poor optical performance of PVB films in the prior art.

[0004] In order to achieve the above object, according to one aspect of the present invention, there is provided a packaging film, comprising a first film layer and a second film layer stacked in sequence;

[0005] The first film layer comprises a first matrix resin, a plasticizer and a nanomaterial, the second film layer comprises a second matrix resin and an acid binder, the color difference value L of the nanomaterial is 10 to 50, and the tanδ of the first film layer is greater than 0.2 at -20 to 50°C.

[0006] Further, the first matrix resin includes polyvinyl butyral resin; and / or,

[0007] The second base resin includes ethylene-vinyl acetate copolymer resin;

[0008] Preferably, when the first matrix resin comprises polyvinyl butyral resin, the degree of polymerization of the polyvinyl butyral resin is 1000 to 1500; preferably, the acetal value of the polyvinyl butyral resin is 78% to 85%, and the hydroxyl value is 18% to 20%; and / or,

[0009] Preferably, when the second matrix resin comprises ethylene-vinyl acetate copolymer resin, the content of vinyl acetate units in the ethylene-vinyl acetate copolymer resin is 18% to 28%.

[0010] Furthermore, in the first adhesive film layer, the mass ratio of the first matrix resin to the nanomaterial is 100:(0.01-5); and / or,

[0011] In the second adhesive film layer, the mass ratio of the second matrix resin to the acid binding agent is 100:(0.01-20).

[0012] Furthermore, the mass ratio of the plasticizer to the first matrix resin is (5-30):100;

[0013] Preferably, the mass ratio of the plasticizer to the first matrix resin is (20-30):100;

[0014] Preferably, the plasticizer is selected from ester plasticizers or ether plasticizers;

[0015] More preferably, the plasticizer is selected from at least one of dimethoxyethylene glycol phthalate, tricresyl phosphate, dipropylene glycol phthalate, triethylene glycol dipelargonate, coumarone-indene resin, trioctyl trimellitate, propylene glycol adipate, dihexyl adipate, tetraethylene glycol di-2-ethylhexanoate, triethylene glycol di-2-ethylbutyrate, tetraethylene glycol di-2-ethylbutyrate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-n-heptanoate, dipentaerythritol hexaoctanoate, bis[2-(2-butoxyethoxy)ethyl]adipate, diethylene glycol dibenzoate, and dipropylene glycol dibenzoate;

[0016] Preferably, the melting point of the plasticizer is below 30°C and the hydroxyl value is 15 to 450 mgKOH / g;

[0017] Preferably, at 25°C, the diffusion coefficient of the plasticizer in the first adhesive film layer is less than 1.10 -16 cm 2 / s.

[0018] Furthermore, the average particle size of the nanomaterial is ≤300 nm;

[0019] Preferably, the average particle size of the nanomaterial is 20 to 300 nm;

[0020] Preferably, the nanomaterial is selected from at least one of cerium oxide, titanium oxide, indium tin oxide, cesium tungsten bronze, tungsten oxide, rare earth sulfide, and carbon black.

[0021] Furthermore, the pH value of the acid binding agent is 8 to 12; and / or,

[0022] The average particle size of the acid binding agent is 0.01 to 150 μm;

[0023] Preferably, the average particle size of the acid binding agent is 1 to 50 μm;

[0024] Preferably, the acid-binding agent includes an inorganic base acid-binding agent and / or an organic base acid-binding agent, wherein the inorganic base acid-binding agent includes at least one of a modified or unmodified metal hydroxide, a modified or unmodified metal oxide, and a modified or unmodified metal carbonate compound, and the organic base acid-binding agent includes at least one of a guanidine compound, an organic amine compound, and an alcoholamine compound;

[0025] Preferably, the inorganic base acid-binding agent includes at least one of a metal hydroxide modified by a coupling agent, a metal oxide modified by a coupling agent, and a metal carbonate compound modified by a coupling agent, and the coupling agent includes at least one of a silane coupling agent, a titanate coupling agent, and a rare earth coupling agent;

[0026] Preferably, the guanidine compound is selected from at least one of (4-aminobutyl)guanidine, 2-vinyl-4,6-diamino-triazine, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 2,4-diamino-6-phenyl-1,3,5-triazine, dodecyltetramethylguanidine carbonate, and hexadecyltetramethylguanidine carbonate;

[0027] Preferably, the organic amine compound is selected from at least one of dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine, melamine, triethylamine, triisobutylamine, carbodiimide, hexamethylenetetramine, cyclohexylamine, tetraalkylamine hydroxide, ammonium hydroxide, choline hydroxide, and benzyltrimethylammonium hydroxide;

[0028] Preferably, the alcoholamine compound is selected from at least one of diethanolamine, triethanolamine, ethanolamine, diisopropanolamine, triisopropanolamine, and N-ethyldiethanolamine.

[0029] Furthermore, the nanomaterial includes one or more acid-binding agents of indium tin oxide, cesium tungsten bronze, and tungsten oxide, and includes at least one of modified or unmodified metal hydroxides, modified or unmodified metal oxides, and modified or unmodified metal carbonate compounds;

[0030] Preferably, the mass ratio of the first matrix resin to the nanomaterial is 100:(0.01-1), and the mass ratio of the second matrix resin to the acid binding agent is 100:(0.02-5).

[0031] Furthermore, the encapsulating film further comprises a barrier layer, and the barrier layer is located between the first film layer and the second film layer;

[0032] Preferably, the barrier layer comprises polyester resin and / or polyolefin resin;

[0033] Preferably, the polyester resin includes polyethylene terephthalate resin and / or polybutylene terephthalate resin, and the polyolefin resin includes one or more of polypropylene resin, polyethylene resin, and poly(4-methyl-1-pentene) resin;

[0034] Preferably, the water vapor transmission rate of the barrier layer is less than 3g / (m 2 ·24h).

[0035] Furthermore, the first adhesive film layer and the second adhesive film layer each independently include at least one of a cross-linking agent, a co-cross-linking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a tackifier, and a pigment;

[0036] Preferably, relative to 100 parts by mass of the first matrix resin or the second matrix resin, the first film layer and the second film layer also independently include 0.01 to 3 parts by mass of a cross-linking agent, 0.01 to 10 parts by mass of a co-cross-linking agent, 0 to 0.4 parts by mass of an ultraviolet light absorber, 0 to 0.5 parts by mass of an antioxidant, 0 to 1.0 parts by mass of a light stabilizer, 0 to 3.0 parts by mass of a tackifier, and 0 to 20 parts by mass of a pigment.

[0037] According to a second aspect of the present invention, a packaging device is provided, comprising a packaging body and an adhesive film layer located on a surface of the packaging body, wherein the adhesive film layer comprises the packaging adhesive film provided by the first aspect.

[0038] By applying the technical solution of the present invention, by adding nanomaterials meeting specific color difference values to the first film layer, visible light can be effectively absorbed, light scattering can be reduced, and transparency can be enhanced. By adding an acid binding agent to the second film layer, corrosive compounds can be effectively neutralized, reducing the corrosion of the first film layer by the corrosive compounds. At the same time, by controlling the tanδ of the first film layer to be greater than 0.2 at -20 to 50°C, the first film layer is ensured to have high adhesion and good damping properties, reducing the transmission of vibration and noise, and effectively blocking the migration of plasticizers and corrosive compounds. This not only ensures that the encapsulation film comprising the first and second film layers maintains high transparency, but also has long-lasting color stability. Fading is significantly reduced in long-term aging tests, which is beneficial to improving the optical properties of the encapsulation film and maintaining the aesthetic and functional characteristics of the encapsulation film. DETAILED DESCRIPTION

[0039] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0040] As described in the background of the present invention, the prior art suffers from the problem of colored PVB films being easily discolored. To address this issue, a typical embodiment of the present invention provides an encapsulation film comprising a first film layer and a second film layer stacked sequentially; wherein the first film layer comprises a first matrix resin, a plasticizer, and a nanomaterial, and the second film layer comprises a second matrix resin and an acid-binding agent; the color difference value L of the nanomaterial is 10 to 50, and the first film layer has a tan delta greater than 0.2 at -20 to 50°C.

[0041] The encapsulation film of the present invention comprises two main components: a first film layer and a second film layer. These two layers are stacked sequentially to form a package that protects and secures glass or sensitive components, such as solar panels or semiconductor devices in photovoltaic devices.

[0042] The first adhesive film layer comprises a first matrix resin, a plasticizer, and a specific nanomaterial. The nanomaterial is used to absorb visible light within a specific wavelength range, and its color difference value L is set within a range of 10 to 50. The color difference value L of the nanomaterial can be 10, 20, 30, 40, 50, or a range consisting of any two thereof. The color difference value L is used to evaluate the brightness difference of the color, that is, within the spectrum from black to white. The present invention limits the color difference value L of the nanomaterial to 10 to 50, indicating that it can effectively absorb visible light, especially light with a wavelength range of 400 to 700 nm, reducing light scattering and diffuse reflection, thereby reducing haze and enhancing transparency.

[0043] The color difference value of a nanomaterial refers to the degree to which the color of a product changes relative to a standard sample after the addition or use of the nanomaterial. The color difference value L of a nanomaterial can be measured using the following method: The color difference value is calculated by comparing the coordinate differences between the sample and the standard sample in a specific color space (such as CIE Lab, CIE LCh, etc.), using the ASTM E308 test standard.

[0044] The second film layer contains a second matrix resin and an acid binder. The acid binder is used to neutralize the acidic substances generated during the aging process of the packaging film, protect the pigments and nanomaterials of the first film layer from corrosion, prevent the color from fading, and ensure the color stability of the packaging film.

[0045] The first adhesive layer maintains a tanδ value greater than 0.2 at temperatures between -20°C and 50°C. Tanδ (dissipation factor) is a key parameter for measuring a material's energy loss under alternating stress, and its value is related to the material's internal friction and viscoelasticity. Maintaining the first adhesive layer's tanδ value above 0.2 within the -20°C to 50°C temperature range indicates that the first adhesive layer possesses high viscoelasticity and good damping properties. This increases the material's internal friction during elastic deformation, leading to greater energy dissipation and preventing displacement. Furthermore, the first adhesive layer effectively absorbs and dissipates vibration energy, thereby reducing the transmission of vibration and noise.

[0046] The tanδ of the first adhesive film layer at -20 to 50°C can be obtained by the following test method: using a dynamic mechanical analysis (DMA) device, setting the temperature control program of the DMA device so that it can perform dynamic mechanical testing within the temperature range of -20 to 50°C, and testing according to the IEC 60250 standard. The storage modulus (E') and loss modulus (E") of the sample are measured, and tanδ is calculated according to tanδ = E" / E'.

[0047] The present invention, by adding a nanomaterial with a color difference value L of 10 to 50 in the first film layer, can effectively reduce the light scattering caused by matrix impurities, enhance the transparency of the encapsulating film, and simultaneously in the second film layer, under the action of an acid binding agent, prevent plasticizer migration and avoid the negative impact of acidic substances on the encapsulating film, thereby significantly improving the color stability of the encapsulating film during long-term use, avoiding color fading or fading, so that the encapsulating film can be guaranteed to have high transparency and lasting color stability, to maintain the aesthetic and functional properties of the encapsulating film. In addition, the use of an acid binding agent can effectively reduce the generation of corrosive compounds, thereby protecting sensitive components or components from corrosion, and improving the safety and reliability of the encapsulated device. Therefore, the encapsulating film of the present invention, through the selection of multilayer combination and specific materials, not only solves the problem of plasticizer migration corrosion and color stability, helps to improve the optical properties such as transparency and color stability of the encapsulating film, but also significantly improves the service life of the encapsulating film, and is suitable for buildings, automobiles and optoelectronic equipment packaging applications with high requirements for optical properties.

[0048] Different matrix resins have different adhesiveness and mechanical properties. In some embodiments, the first matrix resin includes polyvinyl butyral resin; and / or, the second matrix resin includes ethylene-vinyl acetate copolymer resin. Among them, polyvinyl butyral (PVB) has good adhesiveness and impact resistance, while ethylene-vinyl acetate copolymer (EVA) has advantages in weather resistance and softness. By limiting the specific types of the first matrix resin and the second matrix resin, while ensuring the optical properties of the encapsulation film, the weather resistance and softness of the encapsulation film can also be guaranteed, and it can be ensured that the encapsulation film has good processing performance and appropriate mechanical strength.

[0049] When the first matrix resin includes polyvinyl butyral resin, the degree of polymerization (DP) of the polyvinyl butyral resin is 1000-1500. The DP is an important measure of polymer chain length and has a direct impact on the physical and chemical properties of PVB resin. By controlling the DP of the polyvinyl butyral resin to 1000-1500, the polyvinyl butyral resin maintains good flexibility and elasticity while also providing sufficient hardness. Furthermore, it helps form a more uniform microstructure, reducing scattering centers, thereby improving the optical transparency of the encapsulation film. Furthermore, it helps form a tighter network structure, more effectively blocking the penetration of small molecules such as moisture and oxygen.

[0050] Furthermore, the acetal value of polyvinyl butyral (PVB) resin is 78% to 85%, and the hydroxyl value is 18% to 20%. Specifically, the acetal value is an indicator that measures the degree of reaction between the polyvinyl alcohol molecules and butyraldehyde in the PVB resin. A higher acetal value means that the PVA chains in the resin are more fully cross-linked with butyraldehyde, and more acetal groups are formed. This significantly enhances the resistance of the PVB resin to natural environmental factors such as ultraviolet rays, humidity, heat, and acid rain, thereby improving the weather resistance and long-term stability of the packaging material. The hydroxyl value reflects the content of unreacted hydroxyl groups (-OH) in the resin. Excessively high hydroxyl values may cause side reactions in the resin during processing, forming unstable or opaque substances.

[0051] The present invention controls the acetal value to be 78% to 85%, thereby making the molecular structure of the PVB resin more stable and forming a stronger internal network, which helps to improve the tensile strength and impact resistance of the material; controls the hydroxyl value in the PVB resin to be within the range of 18% to 20%, which helps to maintain the transparency and good optical properties of the PVB resin; secondly, controls the hydroxyl value in the PVB resin to be 18% to 20%, which ensures the flexibility of the PVB resin and makes it less likely to crack when subjected to external forces; furthermore, controls the acetal value of the PVB resin to be 78% to 85% and the hydroxyl value to be 18% to 20%, which ensures good adhesion between the first adhesive film layer and the packaging body (such as a glass, metal or other substrate), and simultaneously forms an effective sealing layer to isolate the intrusion of external moisture and oxygen, thereby protecting internal electronic components or optical components from corrosion.

[0052] When the second matrix resin comprises an ethylene-vinyl acetate copolymer resin, the vinyl acetate unit content of the ethylene-vinyl acetate copolymer resin is 18% to 28%. The vinyl acetate unit content of the ethylene-vinyl acetate copolymer resin refers to the mass fraction of the vinyl acetate units in the ethylene-vinyl acetate copolymer resin. The properties of ethylene-vinyl acetate copolymers are affected by the vinyl acetate unit content and molecular weight. The vinyl acetate unit content determines the polarity of the ethylene-vinyl acetate copolymer. A higher content results in stronger polarity and better weatherability, adhesion, and processability. However, an excessively high content may reduce the material's flexibility and heat resistance. Furthermore, the molecular weight of the ethylene-vinyl acetate copolymer affects its mechanical strength and processability. A higher molecular weight improves the mechanical strength of the material, but reduces fluidity and worsens processability. The present invention preferably limits the vinyl acetate unit content to 18% to 28%. This range ensures sufficient flexibility and processability while maintaining good weatherability and adhesion. By limiting the weight average molecular weight of ethylene-vinyl acetate copolymer resin, the optimal balance between mechanical strength and processing performance requirements can be found.

[0053] The content of vinyl acetate units in the ethylene-vinyl acetate copolymer resin may be 18%, 20%, 22%, 24%, 26%, 28% or a range consisting of any two thereof.

[0054] In some embodiments, in the first adhesive film layer, the mass ratio of the first matrix resin to the nanomaterial is 100:(0.01-5), such as 100:0.01, 100:0.05, 100:0.1, 100:0.5, 100:1, 100:2, 100:3, 100:4, 100:5, or any combination thereof. By limiting the mass ratio of the first matrix resin to the nanomaterial, the mechanical properties and impact resistance of the encapsulating film can be further improved while maintaining optical performance.

[0055] In some embodiments, the mass ratio of the second matrix resin to the acid binding agent in the second film layer is 100:(0.01-20), such as 100:0.01, 100:0.1, 100:1, 100:5, 100:10, 100:15, 100:20, or any combination thereof. By limiting the mass ratio of the second matrix resin to the acid binding agent, the processing performance of the encapsulating film and the mechanical strength of the final product can be further improved while maintaining optical performance.

[0056] In some embodiments, the mass ratio of the plasticizer to the first matrix resin is (5-30):100, for example, 5:100, 10:100, 15:100, 20:100, 25:100, 30:100, or a range consisting of any two thereof. By controlling the amount of plasticizer added, the glass transition temperature of the resin can be lowered, allowing the material to maintain good flexibility and elasticity at room temperature and lower temperatures. At the same time, the introduction of the plasticizer can also enhance the adhesion between the resin and different substrates, ensuring the reliability of the packaging structure. In addition, the plasticizer can improve the fluidity and plasticity of the resin, so that it exhibits better processing performance during processing such as extrusion, lamination, and injection molding, helping the material to form a uniform film during processing, reducing processing defects and improving the yield rate. Excessive plasticizer may cause the optical transparency of the material to decrease, while controlling the mass ratio of the plasticizer to the first matrix resin within the range of (5-30):100 can maintain the high transparency of the packaging film. In some preferred embodiments, the mass ratio of the plasticizer to the first matrix resin is (20-30):100, for example, 20:100, 21:100, 22:100, 23:100, 24:100, 25:100, 26:100, 27:100, 28:100, 29:100, 30:100 or a range consisting of any two of them.

[0057] In some embodiments, the melting point of the plasticizer is below 30° C. By controlling the melting point of the plasticizer below 30° C., it is possible to ensure that the material exhibits good flexibility and processability in a wide temperature range, especially at low temperatures.

[0058] In some embodiments, the hydroxyl value of the plasticizer is 15 to 450 mgKOH / g. The hydroxyl value reflects the content of hydroxyl groups in the plasticizer. A lower hydroxyl value may indicate that the plasticizer has a weaker reactivity with the resin, while a higher hydroxyl value may cause unnecessary side reactions and affect the chemical stability of the material. The present invention can adjust the chemical compatibility and reactivity between the plasticizer and the first matrix resin by controlling the hydroxyl value of the plasticizer within the range of 15 to 450 mgKOH / g. Within the above range, a good chemical balance can be achieved, which not only ensures the plasticizing effect of the plasticizer but also maintains the overall chemical stability of the material.

[0059] In some embodiments, at 25° C., the diffusion coefficient of the plasticizer in the first adhesive film layer is less than 1.10. -16 cm 2 By controlling the diffusion coefficient of the plasticizer within the above range, it helps to reduce the potential corrosion or adverse effects of the plasticizer on sensitive electronic components within the package body. Especially in multi-layer packaging structures, it can effectively isolate the interference of the plasticizer on other functional layers and maintain the stable operation of the entire system.

[0060] The diffusion coefficient of the plasticizer in the first film layer can be obtained by the following test method: the first film layer sample containing the plasticizer is mixed with an inert medium (such as The released plasticizer is brought into contact with the inert medium (e.g., an adsorbent) and periodically extracted and analyzed at a constant temperature of 25° C. Specifically, samples can be taken from the surface of the inert medium, and the concentration of the plasticizer on the inert medium can be quantitatively detected using a gas chromatography-mass spectrometer (GC-MS) or other suitable analytical techniques. The plasticizer concentrations of each sample are compared, and the diffusion coefficient of the plasticizer in the first film layer is calculated using a diffusion model. For example, the test can refer to ISO 177:2016 standard.

[0061] The present invention does not limit the specific type of plasticizer. For example, the plasticizer is selected from ester plasticizers or ether plasticizers. Specifically, the plasticizer is selected from at least one of dimethoxyethylene glycol phthalate, tricresyl phosphate, dipropylene glycol phthalate, triethylene glycol dipelargonate, coumarone-indene resin, trioctyl trimellitate, propylene glycol adipate, dihexyl adipate, tetraethylene glycol di-2-ethylhexanoate, triethylene glycol di-2-ethylbutyrate, tetraethylene glycol di-2-ethylbutyrate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-n-heptanoate, dipentaerythritol hexaoctanoate, bis[2-(2-butoxyethoxy)ethyl]adipate, diethylene glycol dibenzoate, and dipropylene glycol dibenzoate.

[0062] In some embodiments, the average particle size of the nanomaterial is ≤300nm. By limiting the average particle size of the nanomaterial to ≤300nm, its dispersibility in the first matrix resin is ensured, thereby maximizing the effect of reducing light scattering, thereby improving the transparency of the encapsulation film. In addition, nanomaterials with a particle size of ≤300nm are more easily mixed with the first matrix resin to form a uniform dispersion, which is beneficial to the processing performance in the process of preparing the film, such as extrusion, casting and other processes. In some preferred embodiments, the average particle size of the nanomaterial is 20 to 300nm, ensuring that the nanomaterial can be fully and evenly distributed in the first matrix resin, helping to form a more uniform light absorption layer, reducing local color unevenness or light scattering caused by excessively large particles, and maintaining the consistency and stability of the color of the encapsulation film.

[0063] The average particle size of the nanomaterial is 20 to 300 nm, for example, 20 nm, 40 nm, 60 nm, 80 nm, 100 nm, 120 nm, 150 nm, 180 nm, 200 nm, 250 nm, 300 nm or a range consisting of any two thereof.

[0064] In some embodiments, the nanomaterial is selected from at least one of cerium oxide, titanium oxide, indium tin oxide, cesium tungsten bronze, tungsten oxide, rare earth sulfides, and carbon black. These nanomaterials have strong light absorption, particularly absorption of visible light, which can reduce haze and scattering, enhancing the color depth and stability of the encapsulant film. Furthermore, through their filling and reinforcement effects, these nanomaterials can improve the mechanical strength and toughness of the encapsulant film, reducing the impact of external shocks on the encapsulant film.

[0065] In some embodiments, the pH value of the acid binding agent is 8 to 12. By limiting the pH value of the acid binding agent, the acid binding agent can provide an alkaline environment to neutralize acidic substances that may be generated during the production or use of the encapsulation film, thereby maintaining the chemical stability of the encapsulation film and extending its service life. At the same time, the acid binding agent can avoid excessively high pH values that may corrode the encapsulation body.

[0066] In some embodiments, the average particle size of the acid binding agent is 0.01 to 150 μm. By limiting the average particle size of the acid binding agent to 0.01 to 150 μm, the acid binding agent is more easily evenly dispersed, increasing the probability of contact with the acidic substance, thereby improving the neutralization efficiency, while also increasing the reaction rate between the acid binding agent and the acidic substance, giving full play to the role of the acid binding agent. In some preferred embodiments, the average particle size of the acid binding agent is 1 to 50 μm. This can avoid agglomeration while maintaining good dispersibility, ensuring efficient neutralization of the acidic substance. At the same time, materials within this particle size range have little effect on the transparency and mechanical properties of the film, helping to maintain the overall performance of the encapsulation film.

[0067] The average particle size of the acid binding agent is 1 to 30 μm, for example, 1 μm, 3 μm, 5 μm, 10 μm, 20 μm, 30 μm, or a range consisting of any two thereof.

[0068] The present invention does not limit the specific type of acid binding agent, for example, the acid binding agent includes an inorganic base acid binding agent and / or an organic base acid binding agent. In some embodiments, the inorganic base acid binding agent includes at least one of a modified or unmodified metal hydroxide, a modified or unmodified metal oxide, and a modified or unmodified metal carbonate compound, and the organic base acid binding agent includes at least one of a guanidine compound, an organic amine compound, and an alcohol amine compound. In the specific implementation process of the present invention, the inorganic base acid binding agent and the organic base acid binding agent can be selected according to specific needs, and can also be used in combination to meet the requirements of the high-performance encapsulation film.

[0069] In some preferred embodiments, the inorganic base acid-binding agent comprises at least one of a metal hydroxide modified with a coupling agent, a metal oxide modified with a coupling agent, and a metal carbonate compound modified with a coupling agent, and the coupling agent comprises at least one of a silane coupling agent, a titanate coupling agent, and a rare earth coupling agent. Modification with the coupling agent can improve the dispersibility of the inorganic base acid-binding agent in the second matrix resin and the interfacial adhesion between the inorganic base acid-binding agent and the second matrix resin, thereby forming a chemical bridge between the two materials to enhance the bonding between the two, thereby improving the acid binding efficiency and the performance of the encapsulating film.

[0070] Specifically, the chemical formula of the silane coupling agent includes YSiX3, where Y can be selected from any of vinyl, epoxy, and methacryloxy groups. These groups can serve as reactive functional groups, reacting with the polymer to enhance inter-material bonding. X can be selected from any of methoxy, ethoxy, and acetoxy groups. These groups can hydrolyze in water to form silanols, which further react with hydroxyl groups on the surface of the inorganic material to form covalent bonds, thereby enhancing the bonding between the inorganic base acid-binding agent and the second matrix resin.

[0071] The chemical formula of the titanate coupling agent is RO-Ti(OX'-R-Y')3, where R is selected from a long carbon-bond alkane group, such as a C8-C18 alkyl group, which increases the compatibility and dispersibility of the acid-binding agent in the second matrix resin. X' is selected from any of methoxy, ethoxy, and acetoxy groups. These groups, upon hydrolysis, can provide additional hydroxyl groups, promoting the bonding of the coupling agent to the inorganic material. Y' is any of hydroxyl, amino, epoxy, and double-bond groups. These functional groups are capable of reacting with the polymer, thereby effectively linking the acid-binding agent to the second matrix resin.

[0072] Among them, the metal hydroxide includes at least one of magnesium hydroxide, calcium hydroxide, zinc hydroxide, barium hydroxide, and aluminum hydroxide, which can be oxidized by hydrogen after hydrolysis; the metal oxide includes at least one of magnesium oxide, calcium oxide, zinc oxide, barium oxide, and aluminum oxide; and the metal carbonate compound includes at least one of magnesium carbonate, calcium carbonate, zinc carbonate, and barium carbonate.

[0073] Guanidine compounds contain a guanidine group and at least one unsaturated bond. This allows them to react with acidic substances through the unsaturated bond, while the guanidine group also has a strong ability to neutralize acidic substances. For example, the guanidine compound is selected from at least one of (4-aminobutyl)guanidine, 2-vinyl-4,6-diaminotriazine, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 2,4-diamino-6-phenyl-1,3,5-triazine, dodecyltetramethylguanidine carbonate, and hexadecyltetramethylguanidine carbonate. By using these guanidine compounds as acid-binding agents, the chemical stability of the encapsulating film can be further improved while maintaining its optical properties.

[0074] The organic amine compound reacts with the acidic substance by providing a lone pair of electrons, thereby neutralizing the acidic substance. The organic amine compound is selected from at least one of dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine, melamine, triethylamine, triisobutylamine, carbodiimide, hexamethylenetetramine, cyclohexylamine, tetraalkylamine hydroxide, ammonium hydroxide, choline hydroxide, and benzyltrimethylammonium hydroxide. By using the above-mentioned organic amine compound as the acid-binding agent, the encapsulating film can further improve its antioxidant and heat resistance while maintaining its optical properties.

[0075] Alcoholamine compounds can effectively neutralize acidic substances through the synergistic effect of alcohol and amine groups. For example, the alcoholamine compound is selected from at least one of diethanolamine, triethanolamine, ethanolamine, diisopropanolamine, triisopropanolamine, and N-ethyldiethanolamine. By using these alcoholamine compounds as acid-binding agents, the encapsulating film's aging resistance and wet-heat stability can be further improved while maintaining its optical properties.

[0076] In order to further improve the comprehensive performance of the encapsulation film, in some embodiments, the nanomaterial includes at least one of indium tin oxide, cesium tungsten bronze, and tungsten oxide, and the acid binding agent includes at least one of modified or unmodified metal hydroxides, modified or unmodified metal oxides, and modified or unmodified metal carbonate compounds; the mass ratio of the first matrix resin to the nanomaterial is 100:(0.01~1), and the mass ratio of the second matrix resin to the acid binding agent is 100:(0.02~5).

[0077] In some embodiments, the encapsulating film further includes a barrier layer positioned between the first and second film layers. The barrier layer primarily isolates the two film layers, maintaining their independence and stability. This layer prevents plasticizers in the first film layer from migrating to the second film layer. Furthermore, it prevents corrosive compounds (such as acidic byproducts) released from the second film layer from affecting the pigments and nanomaterials in the first film layer, thereby preventing color fading and ensuring the color stability of the encapsulating film. The barrier layer also enhances the encapsulating film's resistance to environmental factors (such as humidity and temperature fluctuations), improving its durability and operational stability under harsh conditions.

[0078] The barrier layer acts to isolate different film layers in the encapsulation film, thereby preventing the mutual penetration of chemical substances. In some embodiments, the water vapor transmission rate of the barrier layer is ≤3g / (m 2 ·24h), indicating that within 24 hours, the barrier layer allows no more than 3 grams of water vapor to pass through per square meter. In order to achieve the above-mentioned barrier performance, in some embodiments, the barrier layer comprises polyester resin and / or polyolefin resin. Polyester resin and polyolefin resin have high barrier properties and can effectively prevent the penetration of water vapor, oxygen and other chemicals, thereby ensuring the stability of the internal environment of the packaging film. In some preferred embodiments, the polyester resin includes polyethylene terephthalate (PET) resin and / or polybutylene terephthalate (PBT) resin, and the polyolefin resin includes at least one of polypropylene (PP) resin, polyethylene (PE) resin, and poly(4-methyl-1-pentene) resin. By further limiting the material of the barrier layer, the best barrier effect can be achieved, and the comprehensive performance of the packaging film can be further improved.

[0079] To further enhance the overall performance of the encapsulating film, particularly its physicochemical stability, optical clarity, color durability, and processing properties, in some embodiments, the first and second film layers each independently include at least one of a crosslinking agent, a co-crosslinking agent, an antioxidant, a UV absorber, a light stabilizer, a tackifier, and a pigment. In the implementation of the present invention, the choice and amount of additives can be selected based on actual application requirements.

[0080] The crosslinking agent can promote crosslinking of the matrix resin, achieving a higher degree of crosslinking, thereby improving the mechanical strength and weather resistance of the encapsulation film. In some preferred embodiments, the first and second film layers each independently include 0.01 to 3 parts by mass of the crosslinking agent per 100 parts by mass of the first or second matrix resin. This amount ensures sufficient crosslinking reaction.

[0081] The present invention does not limit the specific type of cross-linking agent. For example, the cross-linking agent includes but is not limited to at least one of tert-butyl peroxy isopropyl carbonate, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butyl peroxy-2-ethylhexyl carbonate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxy carbonate, and tert-butyl peroxy-3,3,5-trimethylhexanoate. This type of cross-linking agent decomposes under heating or light conditions to produce free radicals, which in turn trigger cross-linking reactions between polymer chains, thereby improving the mechanical strength and weather resistance of the encapsulation film.

[0082] A co-crosslinking agent can further promote the crosslinking reaction between the matrix resins, forming a denser network structure, thereby improving the mechanical strength and weather resistance of the encapsulation film. In some preferred embodiments, the first and second film layers each independently include 0.01 to 10 parts by weight of a crosslinking agent per 100 parts by weight of the first or second matrix resin. This amount ensures sufficient crosslinking while preventing material embrittlement caused by excessive crosslinking.

[0083] The present invention does not limit the specific type of the auxiliary crosslinking agent. For example, the auxiliary crosslinking agent includes but is not limited to triallyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, At least one of the following: esters, ditrimethylolpropane tetraacrylate, ditrimethylolpropane tetramethacrylate, propoxylated pentaerythritol tetraacrylate, 2,4,6-tris(2-propenyloxy)-1,3,5-triazine, tricyclodecane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and polyethylene glycol dimethacrylate. These co-crosslinking agents can promote the formation of chemical bonds between polymer molecules, increase the crosslinking density of the material, and thus further enhance the physical properties of the encapsulating film (such as hardness, heat resistance, solvent resistance, and mechanical strength).

[0084] Antioxidants can inhibit or delay oxidative degradation of the adhesive film during processing and use, extending its service life. In some preferred embodiments, the first and second adhesive film layers each independently include 0-0.5 parts by mass of an antioxidant relative to 100 parts by mass of the first or second matrix resin. Adding an appropriate amount of antioxidant effectively resists the effects of heat and oxygen, while avoiding excessive amounts that could affect the transparency and other properties of the adhesive film.

[0085] The present invention does not limit the specific type of antioxidant. For example, the antioxidant can be a hindered phenol compound and / or a phosphite compound. The hindered phenol compound includes but is not limited to 2,6-di-tert-butyl-4-ethylphenol, 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis-(4-ethyl-6-tert-butylphenol), 4,4'-butylene-bis-(3-methyl-6-tert-butylphenol), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] At least one of: 7-octadecyl-3-(4'-hydroxy-3',5'-di-tert-butylphenyl) propionate, and tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane; and phosphite compounds include, but are not limited to, at least one of tris(2,4-di-tert-butylphenyl) phosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl phosphite, tetrakis(2,4-di-tert-butylphenyl)[1,1-phenylene]-4,4'-diyl bisphosphite, and bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite. These can effectively prevent or delay material aging caused by oxidation, thereby further improving the performance and lifespan of the encapsulating film.

[0086] Ultraviolet absorbers absorb ultraviolet energy and convert it into heat, protecting the film and package body from UV damage. In some preferred embodiments, the first and second film layers each independently include 0 to 0.4 parts by weight of ultraviolet absorber per 100 parts by weight of the first or second matrix resin. This amount is sufficient to provide UV protection while maintaining the film's optical clarity.

[0087] The present invention does not limit the specific type of UV absorber. For example, the UV absorber can be a benzophenone compound and / or a benzotriazole compound. For example, the UV absorber includes, but is not limited to, at least one of 2-hydroxy-4-n-octyloxybenzophenone, 2,2-tetramethylenebis(3,1-benzoxazin-4-one), 2-(2'-hydroxy-5-methylphenyl)benzotriazole, and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone. These UV absorbers can enhance the UV protection of the encapsulating film. During the implementation of the present invention, the UV absorber can be determined based on the specific application scenario and material properties to achieve the optimal protection effect.

[0088] Light stabilizers can improve the film's stability under prolonged UV exposure, preventing degradation of its color and performance. In some preferred embodiments, the first and second film layers each independently include 0-1.0 parts by mass of a light stabilizer per 100 parts by mass of the first or second matrix resin. Adding an appropriate amount of light stabilizer can significantly extend the life of the encapsulation film and maintain its long-term performance stability.

[0089] The present invention does not limit the specific type of light stabilizer. For example, the light stabilizer can be a hindered amine compound, including but not limited to bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, a graft copolymer obtained by polymerization of 4-(methyl)acryloyloxy-2,2,6,6-tetramethylpiperidine and α-olefin monomers, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol, 3,5-di-tert-butyl-4-hydroxy-benzoic acid hexadecyl ester, bis-2,2,6,6-tetramethylpiperidinol sebacate and tris(1,2,2,6,6-pentamethyl-4-piperidinyl) phosphite. These light stabilizers can further improve the anti-aging properties of the material and prevent ultraviolet rays and other light from damaging the material.

[0090] Tackifiers are used to improve the adhesion of the film, creating a stronger bond with the package body. In some preferred embodiments, the first and second film layers each independently include 0 to 3 parts by mass of tackifier relative to 100 parts by mass of the first or second base resin. Adding this amount significantly enhances adhesion without negatively impacting other properties of the film.

[0091] The present invention is not limited to a specific type of tackifier. For example, the tackifier includes, but is not limited to, at least one of γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethylsilane, and 3-aminopropyltrimethylsilane. The use of these tackifiers can enhance the internal bonding strength of the encapsulating film and the adhesion between the encapsulating film and the package body.

[0092] Pigments are used to impart a specific color to the encapsulating film. In some preferred embodiments, the first and second film layers each independently include 0-20 parts by weight of pigment per 100 parts by weight of the first or second base resin. The amount of pigment added can be adjusted based on the desired color depth and uniformity, while minimizing its impact on transparency and durability.

[0093] According to a second aspect of the present invention, a packaging device is provided, comprising a packaging body and an adhesive film layer located on a surface of the packaging body, wherein the adhesive film layer comprises the packaging adhesive film provided by the first aspect.

[0094] Because it includes the above-mentioned encapsulation film with excellent performance, the encapsulation film serves as a key barrier between the packaging body and the external environment. It can not only provide mechanical protection and prevent physical damage, but also isolate environmental factors such as moisture and oxygen, protect the internal structure from chemical corrosion, and optimize the optical properties of the packaging body.

[0095] Specifically, the encapsulated body can be an electronic device, a photovoltaic module, an optical element, etc., and the present invention does not impose any further limitations thereon. For example, in some embodiments, the encapsulated body is a glass assembly, and the adhesive film layer is located between any two sheets of glass in the glass assembly. The application of this encapsulated adhesive film in laminated glass not only enhances the safety and sound insulation of the glass, but also improves the optical properties of the glass, such as light transmittance and color stability.

[0096] The present application is further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0097] Example 1

[0098] The method for preparing the encapsulation film of this embodiment includes:

[0099] 1. The raw materials of this embodiment are selected as follows:

[0100] The first matrix resin is PVB resin, the polymerization degree of the PVB resin is 1500, the acetal value is 80%, and the hydroxyl value is 20%;

[0101] The second matrix resin is ethylene-vinyl acetate copolymer, wherein the content of vinyl acetate units is 20%;

[0102] The nanomaterial is a mixture of indium tin oxide, cesium tungsten bronze, and tungsten oxide in a mass ratio of 1:1:1. The color difference value L of the nanomaterial is 30, and the average particle size of the nanomaterial is 200 nm.

[0103] The plasticizer is tricresyl phosphate, the melting point of the plasticizer is 25°C, and the hydroxyl value is 200 mgKOH / g;

[0104] The acid binding agent is magnesium hydroxide, and the average particle size of the acid binding agent is 80 μm;

[0105] The barrier layer contains polyethylene terephthalate resin with a water vapor transmission rate of less than 3g / (m 2 24 hours);

[0106] 2. The specific preparation process of the encapsulation film of this embodiment is as follows: a first base resin, a plasticizer, and a nanomaterial are mixed in a mass ratio of 100:25:1 to obtain a raw material for a first film layer;

[0107] The second base resin and the acid binding agent are mixed in a mass ratio of 100:0.1 to obtain a raw material for the second adhesive film layer;

[0108] The raw materials of the first film layer and the raw materials of the second film layer are mixed separately, melted and plasticized, and then injected into the same die head, and merged into a melt stream in the T-die head. After melt extrusion, film casting, cooling, slitting and winding, an encapsulation film with a stacked first film layer and a second film layer is prepared; the tanδ of the first film layer is greater than 0.2 at -20 to 50°C.

[0109] Example 2

[0110] The difference from Example 1 is that the color difference value L of the nanomaterial is set to 10 by adjusting the content of each component of the nanomaterial.

[0111] Example 3

[0112] The difference from Example 1 is that the color difference value L of the nanomaterial is 50 by adjusting the content of each component of the nanomaterial.

[0113] Example 4

[0114] The difference from Example 1 is that the average particle size of the nanomaterial is 20 nm.

[0115] Example 5

[0116] The difference from Example 1 is that the average particle size of the nanomaterial is 300 nm.

[0117] Example 6

[0118] The difference from Example 1 is that the average particle size of the nanomaterial is 500 nm.

[0119] Example 7

[0120] The difference from Example 1 is that the average particle size of the acid binding agent is 10 μm

[0121] Example 8

[0122] The difference from Example 1 is that the average particle size of the acid binding agent is 50 μm

[0123] Example 9

[0124] The difference from Example 1 is that the average particle size of the acid binding agent is 1 μm

[0125] Example 10

[0126] The difference from Example 1 is that the average particle size of the acid binding agent is 150 μm

[0127] Example 11

[0128] The difference from Example 1 is that the average particle size of the acid binding agent is 0.01 μm

[0129] Example 12

[0130] The difference from Example 1 is that the acid binding agent is magnesium hydroxide modified with vinyl tert-butyl triperoxide.

[0131] Example 13

[0132] The difference from Example 1 is that the acid binding agent is magnesium oxide.

[0133] Example 14

[0134] The difference from Example 1 is that the mass ratio of the first matrix resin to the nanomaterial is 100:5.

[0135] Example 15

[0136] The difference from Example 1 is that the mass ratio of the second matrix resin to the acid binding agent is 100:5.

[0137] Comparative Example 1

[0138] The difference from Example 1 is that the first adhesive film layer is an EVA adhesive film layer, and the tanδ is 0.1 at -20 to 50°C.

[0139] Comparative Example 2

[0140] The difference from Example 1 is that no acid binding agent is added.

[0141] Comparative Example 3

[0142] The difference from Example 1 is that no nanomaterial is added.

[0143] Comparative Example 4

[0144] The difference from Example 1 is that the color difference value L of the nanomaterial is set to 5 by adjusting the ratio of the components in the nanomaterial.

[0145] Comparative Example 5

[0146] The difference from Example 1 is that the color difference value L of the nanomaterial is set to 60 by adjusting the ratio of the components in the nanomaterial.

[0147] Test example

[0148] 1. Optical performance

[0149] Light transmittance test: The films prepared in the examples and comparative examples were tested according to GB / T2410-2008, and the light transmittance of the films at 400-700 nm was measured using a UV-visible spectrophotometer.

[0150] 2. Color Difference Test: Sample preparation: 75mm x 150mm float glass / film / float glass stacked from bottom to top were placed in a vacuum laminator and laminated at 148°C for 16 minutes to produce a laminate. Testing was performed using a standard white board for calibration, followed by testing of the laminated components, with the average value of three random test points taken. The initial color difference (E0) of the film and the color difference (E1) after 96 hours of HAST aging were measured using a spectrophotometer. The color difference change (ΔE) was calculated as (E1 - E0).

[0151] The test results are shown in Table 1.

[0152] Table 1

[0153]

[0154]

[0155] As shown in Table 1, by comparing Examples 1-15 and Comparative Examples 1-5, by adding nanomaterials that meet specific color difference values to the first film layer, controlling the tanδ of the first film layer to be greater than 0.2 at -20 to 50°C, and adding an acid binder to the second film layer, the light transmittance can be improved while reducing the color difference between the film after aging and the initial color. This indicates that the film maintains high transparency while having long-lasting color stability.

[0156] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A packaging film, characterized in that: It comprises a first adhesive film layer and a second adhesive film layer stacked in sequence; The first adhesive film layer comprises a first matrix resin, a plasticizer and a nanomaterial, the second adhesive film layer comprises a second matrix resin and an acid binder, the color difference value L of the nanomaterial is 10 to 50, and the tanδ of the first adhesive film layer is greater than 0.2 at -20 to 50°C.

2. The packaging film according to claim 1, wherein The first matrix resin includes polyvinyl butyral resin; and / or, The second matrix resin includes ethylene-vinyl acetate copolymer resin; Preferably, when the first matrix resin comprises polyvinyl butyral resin, the degree of polymerization of the polyvinyl butyral resin is 1000 to 1500; preferably, the acetal value of the polyvinyl butyral resin is 78% to 85%, and the hydroxyl value is 18% to 20%; and / or, Preferably, when the second matrix resin comprises ethylene-vinyl acetate copolymer resin, the content of vinyl acetate units in the ethylene-vinyl acetate copolymer resin is 18% to 28%.

3. The encapsulating film according to claim 1 or 2, characterized in that: In the first adhesive film layer, the mass ratio of the first matrix resin to the nanomaterial is 100:(0.01-5); and / or, In the second adhesive film layer, the mass ratio of the second matrix resin to the acid binding agent is 100:(0.01-20).

4. The encapsulating film according to any one of claims 1 to 3, characterized in that: The mass ratio of the plasticizer to the first matrix resin is (5-30):100; Preferably, the mass ratio of the plasticizer to the first matrix resin is (20-30):100; Preferably, the plasticizer is selected from ester plasticizers or ether plasticizers; More preferably, the plasticizer is selected from at least one of dimethoxyethylene glycol phthalate, tricresyl phosphate, dipropylene glycol phthalate, triethylene glycol dipelargonate, coumarone-indene resin, trioctyl trimellitate, propylene glycol adipate, dihexyl adipate, tetraethylene glycol di-2-ethylhexanoate, triethylene glycol di-2-ethylbutyrate, tetraethylene glycol di-2-ethylbutyrate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-n-heptanoate, dipentaerythritol hexaoctanoate, bis[2-(2-butoxyethoxy)ethyl]adipate, diethylene glycol dibenzoate, and dipropylene glycol dibenzoate; Preferably, the plasticizer has a melting point of below 30°C and a hydroxyl value of 15 to 450 mgKOH / g; Preferably, at 25° C., the diffusion coefficient of the plasticizer in the first adhesive film layer is less than 1.

10. -16 cm 2 / s.

5. The encapsulating film according to any one of claims 1 to 3, characterized in that: The average particle size of the nanomaterial is ≤300nm; Preferably, the average particle size of the nanomaterial is 20 to 300 nm; Preferably, the nanomaterial is selected from at least one of cerium oxide, titanium oxide, indium tin oxide, cesium tungsten bronze, tungsten oxide, rare earth sulfide, and carbon black.

6. The encapsulating film according to any one of claims 1 to 3, characterized in that: The pH value of the acid binding agent is 8 to 12; and / or, The average particle size of the acid binding agent is 0.01 to 150 μm; Preferably, the average particle size of the acid binding agent is 1 to 50 μm; Preferably, the acid-binding agent comprises an inorganic base acid-binding agent and / or an organic base acid-binding agent, wherein the inorganic base acid-binding agent comprises at least one of a modified or unmodified metal hydroxide, a modified or unmodified metal oxide, and a modified or unmodified metal carbonate compound, and the organic base acid-binding agent comprises at least one of a guanidine compound, an organic amine compound, and an alcoholamine compound; Preferably, the inorganic base acid-binding agent includes at least one of a metal hydroxide modified by a coupling agent, a metal oxide modified by a coupling agent, and a metal carbonate compound modified by a coupling agent, and the coupling agent includes at least one of a silane coupling agent, a titanate coupling agent, and a rare earth coupling agent; Preferably, the guanidine compound is selected from at least one of (4-aminobutyl)guanidine, 2-vinyl-4,6-diamino-triazine, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 2,4-diamino-6-phenyl-1,3,5-triazine, dodecyltetramethylguanidine carbonate, and hexadecyltetramethylguanidine carbonate; Preferably, the organic amine compound is selected from at least one of dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine, melamine, triethylamine, triisobutylamine, carbodiimide, hexamethylenetetramine, cyclohexylamine, tetraalkylamine hydroxide, ammonium hydroxide, choline hydroxide, and benzyltrimethylammonium hydroxide; Preferably, the alcoholamine compound is selected from at least one of diethanolamine, triethanolamine, ethanolamine, diisopropanolamine, triisopropanolamine, and N-ethyldiethanolamine.

7. The encapsulating film according to any one of claims 1 to 3, characterized in that: The nanomaterial includes at least one of indium tin oxide, cesium tungsten bronze, and tungsten oxide; the acid binding agent includes at least one of modified or unmodified metal hydroxides, modified or unmodified metal oxides, and modified or unmodified metal carbonate compounds; Preferably, the mass ratio of the first matrix resin to the nanomaterial is 100:(0.01-1), and the mass ratio of the second matrix resin to the acid binding agent is 100:(0.02-5).

8. The encapsulating film according to any one of claims 1 to 3, characterized in that: The encapsulating film further includes a barrier layer, and the barrier layer is located between the first film layer and the second film layer; Preferably, the barrier layer comprises polyester resin and / or polyolefin resin; Preferably, the polyester resin includes polyethylene terephthalate resin and / or polybutylene terephthalate resin, and the polyolefin resin includes one or more of polypropylene resin, polyethylene resin, and poly(4-methyl-1-pentene) resin; Preferably, the water vapor transmission rate of the barrier layer is lower than 3g / (m 2 ·24h).

9. The encapsulating film according to any one of claims 1 to 3, characterized in that: The first adhesive film layer and the second adhesive film layer further independently include at least one of a cross-linking agent, a co-cross-linking agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a tackifier, and a pigment; Preferably, relative to 100 parts by mass of the first matrix resin or the second matrix resin, the first adhesive film layer and the second adhesive film layer also independently include 0.01 to 3 parts by mass of a cross-linking agent, 0.01 to 10 parts by mass of a co-cross-linking agent, 0 to 0.4 parts by mass of an ultraviolet light absorber, 0 to 0.5 parts by mass of an antioxidant, 0 to 1.0 parts by mass of a light stabilizer, 0 to 3.0 parts by mass of a tackifier, and 0 to 20 parts by mass of a pigment.

10. A packaged device, characterized in that: It comprises a packaging body and a film layer located on the surface of the packaging body, wherein the film layer comprises the packaging film according to any one of claims 1 to 8; preferably, the packaging device is preferably laminated glass.

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