Packaging adhesive film and preparation method thereof

Abstract

The invention relates to the technical field of chemical materials, in particular to a packaging adhesive film and a preparation method thereof. The packaging adhesive film comprises thermoplastic resin and a plasticizer, the thermoplastic resin comprises, by mass, 1%-5% of thermoplastic resin grafted and modified by a silane coupling agent and 95%-99% of unmodified thermoplastic resin, and the polymerization degree of the thermoplastic resin is 1000-1400. In the packaging adhesive film provided by the invention, the thermoplastic resin is subjected to grafting modification treatment, and the molecular chain length of a side chain can be effectively increased by a coupling agent molecule grafted to a side chain group, so that the flexibility of a resin molecular chain is improved; coupling agent molecules grafted to the main chain of resin molecules can interact with hydroxyl groups on other molecular chains to generate hydrogen bonds, so that the acting force between the molecular chains is further enhanced, and the mechanical property of the whole adhesive film is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical materials, and in particular to a packaging adhesive film and a preparation method thereof. Background Art

[0002] The film for encapsulating electronic optical devices is usually used to bond photovoltaic glass, cells, backplanes and other photovoltaic components, and at the same time protects the cells and isolates the air. At present, the mainstream film for encapsulating electronic optical devices is mainly made of EVA. EVA has excellent bonding performance, but its melt viscosity is low. In the process of encapsulating dimming glass devices, EVA flow is prone to uneven thickness, which causes the surface of the dimming film to be compressed and deformed, reducing the yield rate after encapsulation. The hydroxyl groups on the side chains of thermoplastic resins such as PVB molecules can react with the silicon hydroxyl groups on the surface of the glass, and because of its high hydroxyl density and strong force, in laminated glass, although there is no chemical bonding and action, it can also bond the glass together well. However, when facing surfaces with weak hydrogen bonding (such as polyester film), PVB has poor bonding performance, which limits the application of PVB film in the field of electronic optical device packaging.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an electronic optical device packaging film and a preparation method thereof.

[0005] Specifically, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a packaging film, which includes a thermoplastic resin and a plasticizer. In terms of mass percentage, the thermoplastic resin includes 1% to 5% of a thermoplastic resin grafted with a silane coupling agent and 95% to 99% of an unmodified thermoplastic resin. The degree of polymerization of the thermoplastic resin is 1000-1400.

[0006] In the encapsulation film provided by the present invention, the thermoplastic resin is subjected to grafting modification treatment, and the coupling agent molecules grafted onto the side chain groups can effectively increase the molecular chain length of the side chain, thereby increasing the flexibility of the resin molecular chain; the coupling agent molecules grafted onto the main chain of the resin molecule can generate hydrogen bonds by interacting with hydroxyl groups on other molecular chains, further enhancing the interaction force between the molecular chains and improving the mechanical properties of the overall film.

[0007] In the present invention, the silane coupling agent can be selected from various silane coupling agents conventionally available in the art, such as γ-diethylenetriaminepropylmethyldimethoxysilane and aminopropylmethyldiethoxysilane without double bond groups; and 3-(methacryloyloxy)propyltrimethoxysilane, 2-[(2-propylene-1-oxy)methyl]-2-acrylate 3-(trimethoxysilyl)propyl ester, 3-[tri(1-methylethoxy)silyl]propyl methacrylate, 3-trimethoxysilane propyl acrylate, tris(methoxyethoxy)propyl acyloxysilane, etc. containing double bond groups.

[0008] Preferably, the molecular structure of the silane coupling agent contains at least one double bond group.

[0009] Further preferably, the silane coupling agent is selected from at least one of 3-(methacryloyloxy)propyltrimethoxysilane, 2-[(2-propylene-1-oxy)methyl]-2-acrylate 3-(trimethoxysilyl)propyl ester, 3-[tri(1-methylethoxy)silyl]propyl methacrylate, 3-trimethoxysilane propyl acrylate, and tris(methoxyethoxy)propyl acyloxysilane.

[0010] Preferably, the thermoplastic resin is selected from at least one of PVB, TPU, COC and PVC.

[0011] More preferably, the thermoplastic resin is PVB, and the coupling agent molecules are grafted onto the carboxybutyraldehyde groups of the side chains of the PVB molecules. The acetal value of the unmodified PVB is 78% to 85%, and the hydroxyl value is 18% to 20%.

[0012] The present invention uses PVB as the resin material, which has a high melt viscosity, and does not cause glue overflow or uneven thickness during the lamination process; and PVB has the advantages of high light transmittance, low haze, good weather resistance, etc. The present invention broadens the application of PVB film in the field of electronic optical packaging by modifying the PVB molecular chain.

[0013] The molecular structure diagram of the grafted structure of the acetal group in the PVB molecule modified by the silane coupling agent in the encapsulation film of the present invention is shown in FIG. Figure 1 , wherein R1 is an alkyl chain containing at least one double bond.

[0014] Preferably, the plasticizer is selected from at least one of dibutyl phthalate (DBP), dioctyl phthalate (DOP), triethylene glycol diisooctanoate, and polyethylene glycol glycol ether.

[0015] Further preferably, the encapsulation film comprises 70-80 parts of thermoplastic resin, 18-29.5 parts of plasticizer, and 0.5-2 parts of silane coupling agent, wherein the thermoplastic resin is preferably PVB resin.

[0016] The invention optimizes the addition amount of the plasticizer. The specific addition amount of the plasticizer is combined with the PVB resin with a polymerization degree of 1000-1400, which helps to reduce the processing temperature and molding use temperature of the PVB and avoid cross-linking between PVB resin molecules.

[0017] The present invention optimizes the addition amount of the silane coupling agent. The specific addition amount of the silane coupling agent can obtain a moderate grafting rate in the subsequent grafting modification process, avoid excessive side chain grafting leading to poor fluidity and difficulty in encapsulation and assembly, avoid excessive coupling agent residues and double bonds reacting, and avoid excessive doses of radiation-induced PVB molecular chain breakage, and avoid excessive adhesion-induced poor penetration resistance.

[0018] Furthermore, the packaging film further comprises the following raw materials in parts by weight: 0.1-2 parts of an anti-ultraviolet agent, and / or 0.1-2 parts of an antioxidant.

[0019] The addition of antioxidants and anti-ultraviolet agents helps to prevent the film from oxidizing and yellowing. The addition of antioxidants also helps to quench excessive free radicals generated during the reaction and improve the quality control effect.

[0020] The present invention optimizes the amount of antioxidant added. The specific amount of antioxidant added is more conducive to protecting the PVB molecular chains under the effects of heat, shearing and radiation during extrusion processing and radiation (or other grafting modification methods), avoiding molecular chain degradation, breakage and yellowing, and affecting the optical properties of the film.

[0021] Preferably, the antioxidant includes a primary antioxidant and an auxiliary antioxidant; the mass ratio of the primary antioxidant to the auxiliary antioxidant is 2±0.5:1; the primary antioxidant is selected from one or more of antioxidant 1010, antioxidant 1076, and antioxidant BHT; the auxiliary antioxidant is selected from one or more of antioxidant 168, antioxidant 626, and antioxidant DLTP.

[0022] In the present invention, the primary antioxidant is a free radical scavenger, which consumes free radicals and generates hydroperoxides by itself. The secondary antioxidant has a synergistic effect with the primary antioxidant, and the secondary antioxidant decomposes the hydroperoxides, reduces the primary antioxidant, and maintains its activity.

[0023] The addition of the antioxidant of the present invention can protect the PVB molecular chain in the two processes of generating free radicals. When the antioxidant content is too low, the effect is poor; and when the content is too high, the color of the product is affected. The present invention selects a primary antioxidant and an auxiliary antioxidant in a specific mass ratio, which can not only meet the quality control of the film during the entire reaction process, but also reduce the amount of antioxidant used and reduce production costs.

[0024] Preferably, the anti-ultraviolet agent is selected from one or more of UV326, UV328, UV329, and UV360.

[0025] Optionally, in one of the more specific embodiments provided by the present invention, the electronic optical device encapsulation film is a PVB film, which is composed of the following components in parts by weight: 70-80 parts of PVB resin, 18-29.5 parts of plasticizer, 0.1-2 parts of anti-ultraviolet agent, 0.1-2 parts of antioxidant, and 0.5-2 parts of silane coupling agent.

[0026] In a second aspect, the present invention provides a method for preparing the encapsulation adhesive film, comprising: subjecting raw materials including a thermoplastic resin, a plasticizer and a silane coupling agent to sequentially blending extrusion, casting film formation and grafting modification to obtain the encapsulation adhesive film; after the grafting modification treatment, the amount of the thermoplastic resin grafted with the silane coupling agent on the side chain accounts for 1% to 5% of the total amount of the thermoplastic resin.

[0027] The present invention preferably controls the moisture content of the raw materials and the moisture content during the processing, thereby reducing the influence of excessive moisture content on the stability of the siloxane. Preferably, the moisture content of the thermoplastic resin is less than 0.01%.

[0028] Preferably, the temperature of the processing section of the co-extrusion is 130-140° C., and the outlet temperature of the cast film is less than 150° C.; the water content of the film after the co-extrusion is 0.05%-0.1%.

[0029] Preferably, the grafting modification method is irradiation initiation, and the irradiation intensity is 20-50 kGy.

[0030] In one of the more specific and preferred embodiments provided by the present invention, the electronic optical device encapsulation film is a PVB film, which is composed of the following components in parts by weight: 70-80 parts of PVB resin, 18-29.5 parts of plasticizer, 0.1-2 parts of anti-ultraviolet agent, 0.1-2 parts of antioxidant, and 0.5-2 parts of silane coupling agent.

[0031] Further, in this more specific embodiment, preferably, the extrusion casting method of the PVB film comprises the following steps: dispersing and dissolving the anti-ultraviolet agent, antioxidant, and silane coupling agent in the plasticizer, and then extruding the PVB resin and the plasticizer by a twin-screw extruder; while adding the antioxidant and the anti-ultraviolet agent, the present invention preferably turns on the vacuum equipment during the processing to reduce the oxygen content in the melt, which can better avoid the yellowing of the film caused by the oxidation of the melt during the blending shearing process. The PVB resin is further dried with hot air before processing, and the moisture content is controlled to be less than 0.01%. It is processed by twin-screw extrusion, the processing temperature is 130-140°C, the film outlet temperature from the die casting is lower than 150°C, and the film is controlled to have a moisture content of 0.05-0.1% by a moisture control system. During the processing, it is necessary to turn on the vacuum equipment to reduce the oxygen content in the melt to avoid the yellowing of the film caused by the oxidation of the melt during the blending shearing process.

[0032] Further, in this more specific embodiment, in the unmodified PVB resin, the mass percentage of hydroxyl is 20%, and the mass percentage content of acetal group is 80%. Converted into a molar ratio, the molar ratio of hydroxyl is 30%, and the molar percentage content of acetal group is 70%. Preferably, the PVB film is post-treated as follows: the cast PVB film is irradiated, and active sites appear on the PVB molecular chain after irradiation, and the double bond of the coupling agent containing double bonds is opened, and the coupling agent is bonded to the side chain of the PVB molecule. The irradiation intensity is 20-50kGy, and the irradiation method is α-ray, β-ray, γ-ray, X-ray, neutron ray or high-energy electron beam. Under the action of irradiation, the alkyl group of the acetal group will produce free radical sites, the CH bond on the PVB molecular chain will break, and a free radical site will be generated. The silane coupling agent with double bonds will open the double bonds and react with the free radicals on the PVB molecular chain for grafting. Most of the technologies reported so far use peroxide thermally initiated silane coupling agent grafting. Under high temperature and shearing, the efficiency of grafting will be reduced. The heat and mass transfer efficiency in the melt is relatively high, and the antioxidant has a high efficiency in quenching active free radicals, which further reduces the efficiency of grafting. The solution provided by the present invention is suitable for initiating grafting at room temperature. The temperature is close to the glass transition temperature of the PVB molecular chain, the mass transfer activity is limited, the antioxidant has little effect, and the local grafting efficiency is high.

[0033] Further, in this more specific embodiment, preferably, the present invention laminates the obtained PVB film and the polyester film. Before laminating, the film is placed in a constant temperature and humidity room to control the moisture content of the PVB film. The temperature of the constant temperature and humidity room is 20±5°C, the humidity is 40±10%, the moisture control range of the PVB film is 0.35-0.50%, the laminating temperature is 125-135°C, the vacuuming time is 2 minutes, and the lamination time is 10 minutes.

[0034] The method for preparing the electronic optical device encapsulation adhesive film provided by the present invention does not require the modification of the PVB raw material in advance. Instead, after the co-blending and extrusion into a film, the silane coupling agent is grafted onto the resin molecules (such as PVB) by irradiation or the like, and the obtained product contains an appropriate proportion of grafted PVB molecules (the amount of the thermoplastic resin grafted with the silane coupling agent on the side chain accounts for 1% to 5% of the total amount of the thermoplastic resin).

[0035] The method for preparing the electronic optical device packaging film provided by the present invention has short steps, high product rate, appropriate acetal reaction temperature, simple operation, and is suitable for industrial promotion and application. The electronic optical device packaging film obtained by the method for preparing the electronic optical device packaging film provided by the present invention has good mechanical properties.

[0036] In a third aspect, the present invention provides an electronic optical device comprising the aforementioned packaging film.

[0037] The encapsulation film provided by the present invention can be applied to electronic optical devices. For example, when applied to the assembly of photovoltaic modules, the alkoxy groups of the coupling agent molecules react with water molecules to generate silanol groups, which react with the groups on the surface of the polyester film to play a bonding role. Preferably, the water content of the thermoplastic resin is less than 0.01%.

[0038] Beneficial effects: The present invention provides a packaging film and a preparation method thereof, wherein the packaging film comprises a thermoplastic resin and a plasticizer, wherein the thermoplastic resin comprises, by mass percentage, 1% to 5% of a thermoplastic resin grafted and modified with a silane coupling agent and 95% to 99% of an unmodified thermoplastic resin, and the degree of polymerization of the thermoplastic resin is 1000 to 1400. In the packaging film provided by the present invention, the thermoplastic resin is subjected to a grafting modification treatment, and the coupling agent molecules grafted onto the side chain groups can effectively increase the molecular chain length of the side chain, thereby increasing the flexibility of the resin molecular chain; the coupling agent molecules grafted onto the main chain of the resin molecule can generate hydrogen bonds by interacting with hydroxyl groups on other molecular chains, further enhancing the interaction between the molecular chains and improving the adhesion between the thermoplastic resin film and the polyester film. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be described below.

[0040] Figure 1 It is a schematic diagram of the grafting structure of the acetal group in the PVB molecule grafted and modified by a silane coupling agent in the electronic optical device packaging film of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The endpoints and any values ​​of the ranges disclosed in this specification are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0043] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific implementations", or "some specific implementations" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0044] In the examples provided in this specification, if no specific techniques or conditions are specified, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0045] In the following examples: PVB resin was purchased from East Materials Technology, DFS1719-01 and DFS1719-03.

[0046] The calculation method of grafting rate is as follows: pure resin is mixed with different proportions of silane coupling agent and then the film is tested by infrared spectrum, with 1080cm -1 The peak area of ​​Si-OC at different contents was measured to form a standard curve. For the irradiated film, Soxhlet extraction was used, with n-hexane or petroleum ether as solvent, at 70°C, refluxed for 24 hours, and the extracted film was tested for infrared spectra, the peak area was calculated, the corresponding standard curve was found, and the grafting rate was calculated.

[0047] The embodiments of the present invention each provide an electronic optical device packaging adhesive film, and each electronic optical device packaging adhesive film is prepared by mixing and extruding its corresponding production raw materials, casting film forming and irradiation treatment. The details are as follows: Example 1 This embodiment provides an electronic optical device packaging film, the raw materials of which are calculated by weight: 75 parts of PVB resin (resin water content is 0.005%), 23.6 parts of plasticizer, and 1.4 parts of silane coupling agent. Among them, the PVB resin is selected from PVB resin with an acetal value of 80%, a hydroxyl value of 19%, and a polymerization degree of 1200, the plasticizer is selected from triethylene glycol diisooctanoate, and the silane coupling agent is selected from 3-(methacryloyloxy)propyltrimethoxysilane.

[0048] This embodiment also provides a method for preparing the above-mentioned electronic optical device packaging film, the steps are: The silane coupling agent is dispersed and dissolved in the plasticizer, and then the PVB resin and the plasticizer are blended and extruded through a twin-screw extruder. The processing temperature of the screw section is 135°C, the temperature of the extrusion die is 145°C, and the cast film is treated with α-rays with an irradiation intensity of 30 kGy. The mass ratio of the silane-modified PVB resin is 2.1%.

[0049] Example 2 This embodiment provides an electronic optical device packaging film. The difference from Embodiment 1 is that the raw materials of the packaging film are composed of 70 parts of PVB resin, 28 parts of plasticizer, and 2 parts of silane coupling agent in parts by weight.

[0050] Example 3 This embodiment provides an electronic optical device packaging film. The difference from Embodiment 1 is that the raw materials of the packaging film are composed of 80 parts of PVB resin, 18 parts of plasticizer, and 2 parts of silane coupling agent in parts by weight.

[0051] Example 4 This embodiment provides an electronic optical device packaging film, which is different from Embodiment 1 in that the acetal value of the PVB resin is 78%.

[0052] Example 5 This embodiment provides an electronic optical device packaging film, which is different from Embodiment 1 in that the acetal value of the PVB resin is 85%.

[0053] Example 6 This embodiment provides an electronic optical device packaging film, which is different from Embodiment 1 in that the hydroxyl value of the PVB resin is 18%.

[0054] Example 7 This embodiment provides an electronic optical device packaging film, which is different from Embodiment 1 in that the hydroxyl value of the PVB resin is 20%.

[0055] Example 8 This embodiment provides an electronic optical device packaging film, which is different from the embodiment 1 in that the polymerization degree of the PVB resin is 1000.

[0056] Example 9 This embodiment provides an electronic optical device packaging film, which is different from the embodiment 1 in that the polymerization degree of the PVB resin is 1400.

[0057] Example 10 This embodiment provides an electronic optical device packaging film, which is different from Embodiment 1 in that the mass ratio of the silane-modified PVB resin in the PVB resin is 1%.

[0058] Embodiment 11 This embodiment provides an electronic optical device packaging film, which is different from Embodiment 1 in that the mass ratio of the silane-modified PVB resin in the PVB resin is 5%.

[0059] Example 12 This embodiment provides an electronic optical device packaging film, which is different from the embodiment 1 in that the packaging film also includes an antioxidant and a UV absorber, and the raw materials thereof are calculated by weight as follows: 75 parts of PVB resin (resin water content is 0.005%), 23 parts of plasticizer, 1.4 parts of silane coupling agent, 0.2 parts of antioxidant, and 0.4 parts of UV absorber. The anti-ultraviolet agent is UV329, and the antioxidants are the main antioxidant 1010 and the auxiliary antioxidant 168, which are mixed in a mass ratio of 2:1.

[0060] Example 13 This embodiment provides an electronic optical device packaging film, which is different from Embodiment 1 in that the silane coupling agent is aminopropylmethyldiethoxysilane.

[0061] Embodiment 14 This embodiment provides an electronic optical device packaging film, which is different from Embodiment 1 in that the plasticizer is selected from dioctyl phthalate.

[0062] Embodiment 15 This embodiment provides an electronic optical device packaging film, which is different from the embodiment 1 in that the thermoplastic resin PVB is replaced by TPU resin, and the TPU is BASF Elastollan® L700.

[0063] Comparative Example 1 The only difference between this comparative example and Example 1 is that no silane coupling agent is used.

[0064] Comparative Example 2 This comparative example provides an electronic optical device packaging film, which is different from Example 1 in that the polymerization degree of the PVB resin is 800.

[0065] Comparative Example 3 This comparative example provides an electronic optical device packaging film, which is different from Example 1 in that the polymerization degree of the PVB resin is 1600.

[0066] Comparative Example 4 This comparative example provides an electronic optical device packaging film, which is different from Example 1 in that the mass ratio of the silane-modified PVB resin in the PVB resin is 0.7%.

[0067] Comparative Example 5 This comparative example provides an electronic optical device packaging film, which is different from Example 1 in that the mass ratio of the silane-modified PVB resin in the PVB resin is 5.6%.

[0068] The performance of the films of the embodiments and comparative examples was tested, and the specific method was as follows: 1. Adhesion: Use polyester film as the support layer, laminate the polyester film + embodiment or comparative example encapsulation film + glass together, and test the initial bonding strength; test the bonding strength after aging at 85°C and 85% humidity for 1000 hours.

[0069] 2. Water content: Measured according to the moisture content test method specified in JC / T 2166-2013.

[0070] The test results of the film properties of the embodiments and comparative examples are shown in Table 1.

[0071] Table 1

[0072] As can be seen from Table 1, the encapsulation film of the present invention is stable in terms of adhesion and water content, and shows certain advantages compared to each comparative example. Among them, comparative example 1 does not use silane coupling agent, the initial adhesion of the product is the lowest, and the adhesion is almost lost after 1000 hours of high temperature and high humidity treatment. The polymerization degree of the material in comparative example 2 is too low, the fluidity is too good, and the edge overflow is serious during the bonding process. The overall thickness uniformity is poor, and the average value of the adhesion test is low. The polymerization degree of the material in comparative example 3 is too high, the fluidity is poor, the interface wettability is poor, and there will be local lack of glue, which affects the bonding performance. The proportion of silane-modified PVB resin in the PVB resin of comparative example 4 is relatively low, and the initial adhesion and adhesion after 1000 hours of high temperature and high humidity treatment are generally low. The proportion of silane-modified PVB resin in the PVB resin of the comparative example is relatively high, the polarity of the material as a whole is increased, the film has high water absorption, the initial adhesion is high, and the adhesion is too low after aging at high temperature and high humidity for 1000 hours.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A packaging film, characterized in that: The packaging film comprises a thermoplastic resin and a plasticizer. In terms of mass percentage, the thermoplastic resin comprises 1% to 5% of a thermoplastic resin grafted and modified with a silane coupling agent and 95% to 99% of an unmodified thermoplastic resin. The degree of polymerization of the thermoplastic resin is 1000-1400.

2. The packaging film according to claim 1, characterized in that: The molecular structure of the silane coupling agent contains at least one double bond group; Preferably, the silane coupling agent is selected from at least one of 3-(methacryloyloxy)propyltrimethoxysilane, 2-[(2-propylene-1-oxy)methyl]-2-acrylate 3-(trimethoxysilyl)propyl ester, 3-[tri(1-methylethoxy)silyl]propyl methacrylate, 3-trimethoxysilane propyl acrylate, and tris(methoxyethoxy)propyl acyloxysilane.

3. The packaging film according to claim 1 or 2, characterized in that: The thermoplastic resin is selected from at least one of PVB, TPU, COC and PVC.

4. The packaging film according to any one of claims 1 to 3, characterized in that: The thermoplastic resin is PVB, wherein the acetal value of unmodified PVB is 78%-85%, and the hydroxyl value is 18%-20%.

5. The encapsulation film according to any one of claims 1 to 4, characterized in that: The plasticizer is selected from at least one of dibutyl phthalate, dioctyl phthalate, triethylene glycol diisooctanoate and polyethylene glycol ethylene glycol.

6. The packaging film according to claim 1, characterized in that: The packaging film comprises 70-80 parts of thermoplastic resin, 18-29.5 parts of plasticizer, and 0.5-2 parts of silane coupling agent; Preferably, the thermoplastic resin is PVB resin; Preferably, the packaging film further comprises the following raw materials in parts by weight: 0.1-2 parts of an anti-ultraviolet agent, and / or 0.1-2 parts of an antioxidant.

7. The packaging film according to claim 1, characterized in that: The packaging film has a water content in the range of 0.35-0.50% at a temperature of 20±5° C. and a humidity of 40±10%.

8. The method for preparing the encapsulating adhesive film according to any one of claims 1 to 7, characterized in that: The raw materials including thermoplastic resin, plasticizer and silane coupling agent are successively subjected to co-extrusion, film casting and grafting modification to obtain the thermoplastic resin; after the grafting modification treatment, the amount of the thermoplastic resin grafted with the silane coupling agent on the side chain accounts for 1% to 5% of the total amount of the thermoplastic resin by mass; Preferably, the water content of the thermoplastic resin is less than 0.01%; the temperature of the processing section of the co-extrusion is 130-140°C, and the outlet temperature of the cast film is less than 150°C; the water content of the film after the co-extrusion is 0.05%-0.1%.

9. The method for preparing a packaging adhesive film according to claim 8, characterized in that: The grafting modification method is photoinitiation, thermal initiation or radiation initiation; Preferably, the grafting modification method is irradiation-induced, and the irradiation intensity is 20-50 kGy; Preferably, the irradiation method is α-rays, β-rays, γ-rays, X-rays, neutron rays or high-energy electron beams.

10. An electronic optical device comprising the packaging film according to any one of claims 1 to 8.

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