CN115368830B - Adhesive film, preparation method and application thereof - Google Patents

Abstract

The present invention provides an adhesive film, a preparation method and application thereof. After the adhesive film is laminated, its Shore A hardness is <80; the storage modulus of the adhesive film at 40°C is <10MPa, the storage modulus at 60°C is <4MPa, and the storage modulus at 85°C is <1.3MPa. Based on this, the present invention effectively reduces the probability of hidden cracks by reducing the hardness and storage modulus of the adhesive film in the initial stage. It should be noted that hidden cracks caused by lamination usually occur in the initial pressurization stage after the lamination heating stage (vacuuming stage). Under the stress of subsequent processing or use, especially in the process of lamination with battery cells, the adhesive film can better protect the battery cells and prevent hidden cracks from occurring in the battery cells, thereby improving the power generation efficiency of photovoltaic modules.

Description

Adhesive film, preparation method and application thereof

Technical Field

The present invention relates to the photovoltaic field, and in particular to an adhesive film, a preparation method and application thereof.

Background Art

When white packaging materials are used as the back layer of photovoltaic packaging materials, they have a higher reflectivity and can provide photovoltaic modules with higher power generation efficiency than transparent films, so they are very popular among module manufacturers. However, the special material structure of white packaging materials leads to higher hardness and storage modulus. During use, especially during lamination, it will cause hidden cracks in the cells, thereby reducing the power generation efficiency of photovoltaic modules. Therefore, it is urgent to develop a film with high reflectivity, low hardness and low storage modulus.

Summary of the invention

The main purpose of the present invention is to provide an adhesive film, a preparation method and application thereof, so as to solve the problem in the prior art that the adhesive film has high hardness and storage modulus, which leads to the problem of hidden cracks in the battery cell.

In order to achieve the above object, according to one aspect of the present invention, a film is provided. After lamination, the film has a Shore A hardness of <80; a storage modulus of <10MPa at 40°C, a storage modulus of <4MPa at 60°C, and a storage modulus of <1.3MPa at 85°C.

Furthermore, the adhesive film is a transparent adhesive film or a colored adhesive film, and the colored adhesive film is preferably a white adhesive film.

Furthermore, during the lamination process, the processing temperature is 130-170° C., and the processing time is 5-30 min; the cross-linking degree of the adhesive film is greater than 80%, and the peeling strength with the back sheet is greater than 40 N/cm.

Furthermore, the adhesive film includes a main resin and fillers and functional additives dispersed in the main resin; wherein the functional additive is liquid rubber; preferably, the liquid rubber is selected from one or more of liquid polysulfide rubber, liquid nitrile rubber, and liquid silicone rubber.

Furthermore, the viscosity of the liquid rubber at 23° C. is 1000 to 10000 pcs.

Furthermore, the adhesive film includes 100 parts of a main resin, 0 to 50 parts of a filler and 0.5 to 5 parts of a functional additive, in parts by weight.

Furthermore, the adhesive film also includes a processing aid dispersed in the main resin, and the processing aid is a polymer dispersant with a melting point below 110°C.

Furthermore, the polymer dispersant is selected from one or more of polyethylene wax, polypropylene wax, silicone wax, ethylene-propylene copolymer, hexenyl bisstearamide, stearic acid monoglyceride, tristearic acid glyceride, liquid paraffin, microcrystalline paraffin, barium stearate, cadmium stearate, magnesium stearate, and copper stearate.

Furthermore, the added amount of the processing aid is 0.01-1% of the weight of the main resin.

Furthermore, the adhesive film also includes an encapsulation aid dispersed in the main resin, and the encapsulation aid is selected from one or more of a cross-linking agent, a co-cross-linking agent, a heat stabilizer, a light stabilizer, an antioxidant, and an ultraviolet light absorber; preferably, the amount of the encapsulation aid added is 0.01 to 1% by weight of the main resin.

Furthermore, the filler is selected from one or more of titanium dioxide, barium sulfate, bentonite, white carbon black, wollastonite, whisker silicon, talc, magnesium hydroxide, magnesium oxide, aluminum hydroxide, and aluminum oxide; preferably, the filler is a filler modified by one or more of silane coupling agent, titanate coupling agent, stearic acid, and palmitic acid; preferably, the main resin is selected from EVA and/or POE.

In order to achieve the above object, according to one aspect of the present invention, a method for preparing the above adhesive film is provided. The preparation method comprises the following steps: mixing the raw materials of the adhesive film, and then performing melt extrusion, film casting, and cooling to obtain the adhesive film; or sequentially performing melt extrusion, film casting, cooling, and pre-crosslinking to obtain the adhesive film, wherein the pre-crosslinking process adopts one or more of thermal crosslinking, ultraviolet crosslinking, and radiation crosslinking.

To achieve the above object, according to one aspect of the present invention, a use of the above adhesive film is provided: the adhesive film is used as an adhesive film for encapsulating electronic devices, and the electronic devices are selected from photovoltaic modules, light-emitting semiconductor LEDs, organic light-emitting semiconductor OLEDs or display screens.

After lamination, the adhesive film provided by the present invention has a Shore A hardness of <80 (the conventional white film hardness on the market is >80); the storage modulus of the adhesive film at 40°C is <10MPa, the storage modulus at 60°C is <4MPa, and the storage modulus at 85°C is <1.3MPa. The adhesive film provided by the present invention has low storage modulus and low hardness. Under the stress of subsequent processing or use, especially in the process of lamination with the battery cell, the adhesive film can better protect the battery cell and prevent the battery cell from cracking, thereby improving the power generation efficiency of the photovoltaic module.

DETAILED DESCRIPTION

It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

As described in the background technology section, the adhesive film in the prior art has high hardness and storage modulus, which leads to the phenomenon of hidden cracks in the battery cell. In order to solve the above problems, the present invention provides an adhesive film, which has a Shore A hardness of <80 after lamination; the storage modulus of the adhesive film at 40°C is <10MPa, the storage modulus at 60°C is <4MPa, and the storage modulus at 85°C is <1.3MPa. Based on this, the present invention effectively reduces the probability of hidden cracks by reducing the hardness and storage modulus of the adhesive film in the initial stage. It should be noted that the hidden cracks caused by lamination usually occur in the initial pressurization stage after the lamination heating stage (vacuum stage). Under the stress of subsequent processing or use, especially in the process of lamination with the battery cell, the adhesive film can better protect the battery cell and prevent the battery cell from having hidden cracks, thereby improving the power generation efficiency of the photovoltaic module.

The adhesive film may be a transparent adhesive film or a colored adhesive film. For the purpose of further balancing the reflectivity and low modulus of the adhesive film, the adhesive film is preferably a colored adhesive film, and more preferably a white adhesive film.

Preferably, during the lamination process, the treatment temperature is 130-170°C and the treatment time is 5-30min. After the lamination process, the Shore A hardness is <80. At the same time, at 130-170°C, the adhesive film undergoes thermal curing. After curing, the rubber molecular chains are cross-linked and shaped. In addition, the addition of fillers makes the laminated adhesive film still have a good packaging effect, such as no overflow of colored adhesive film, wrinkles, etc., and good adhesion with the backboard. Preferably, the cross-linking degree of the adhesive film is greater than 80%, and the peel strength with the backboard is greater than 40N/cm. Preferably, the reflectivity of the adhesive film is greater than 94%. Based on this, the adhesive film of the present invention not only has high reflectivity, but also has low hardness and low storage modulus. Under the stress of subsequent processing or use, especially in the process of lamination with the battery cell, the adhesive film can better protect the battery cell and prevent the battery cell from cracking, and has other good packaging properties, thereby improving the power generation efficiency of the photovoltaic module.

Preferably, the adhesive film includes a main resin and fillers and functional additives dispersed in the main resin; wherein the functional additive is liquid rubber. The adhesive film provided by the present invention has liquid rubber and fillers added to the main resin. Liquid rubber has good flexibility, and because it is in a liquid state, it is easy to be added to the main resin and present a good dispersion state therein. Therefore, adding such rubber soft chain molecules can effectively reduce the hardness and storage modulus of the adhesive film. At the same time, the introduction of fillers in the adhesive film not only maintains the excellent high reflectivity and other properties of the adhesive film itself, but also can use the fillers to increase the stability of the three-dimensional network structure of the rubber soft chain molecules to a certain extent, so that the adhesive film can be more flexible while better maintaining the microscopic morphology to the later process.

Preferably, the liquid rubber is selected from one or more of liquid polysulfide rubber, liquid nitrile rubber, and liquid silicone rubber. Based on the above types of liquid rubber, it has better compatibility with the main resin and filler, and can form a flexible three-dimensional network structure with better flexibility with a relatively small amount of addition, thereby further reducing the hardness and storage modulus of the film and improving the problem of hidden cracks in the battery cell.

For the purpose of further improving the compatibility and dispersibility of the liquid rubber with other components, preferably, the viscosity of the liquid rubber at 23° C. is 1000 to 10000 pcs.

Preferably, the adhesive film comprises 100 parts of the main resin, 0 to 50 parts of the filler and 0.5 to 5 parts of the functional additives by weight. Controlling the amount relationship of the balanced adhesive film components within the above range is more conducive to the comprehensive performance of the adhesive film, so that while satisfying the packaging performance of the adhesive film itself, it further improves the flexibility of the adhesive film and reduces the probability of hidden cracks in the packaging component. More preferably, the adhesive film comprises 100 parts of the main resin, 5 to 20 parts of the filler and 0.5 to 5 parts of the functional additives by weight.

Preferably, the adhesive film also includes a processing aid dispersed in the main resin, and the processing aid is a polymer dispersant with a melting point below 110°C. The present invention can improve the compatibility of liquid rubber and filler by adding the above-mentioned processing aid to the main resin, effectively avoid filler agglomeration, and promote the filler to be more evenly dispersed in the main resin. More preferably, the polymer dispersant is selected from one or more of PE wax, PP wax, silicone wax, and ethylene-propylene copolymer. Based on this, the components in the adhesive film can have better compatibility with less addition of processing aids, the filler is more evenly dispersed in the main resin, and the interface effect between the filler and the polymer is greatly improved, so that the adhesive film has better performance.

In order to further improve the compatibility of the filler with the main resin and the liquid rubber and improve the flexibility of the rubber film, the processing aid is preferably added in an amount of 0.01 to 1% by weight of the main resin.

In a preferred embodiment, the adhesive film further includes an encapsulation aid dispersed in the main resin (the adhesive film is used as an encapsulation adhesive film at this time), and the encapsulation aid is selected from one or more of a cross-linking agent, a cross-linking aid, a heat stabilizer, a light stabilizer, an antioxidant, and an ultraviolet light absorber. Preferably, the amount of the encapsulation aid added is 0.01 to 1% of the weight of the main resin. Based on this, the excellent encapsulation properties of the adhesive film itself can be better maintained, and the hardness and storage modulus are lower, which can better protect the battery cell and prevent the battery cell from cracking during subsequent use or processing, especially during lamination with the battery cell.

Preferably, the crosslinking agent is a peroxide crosslinking agent, including but not limited to tert-butyl peroxycarbonate isopropyl ester, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, tert-butyl peroxycarbonate-2-ethylhexyl ester, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane One or more of 1,2-dimethyl-2-(tert-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(tert-amylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, 2,2-di(tert-butylperoxy)butane, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxycarbonate, and tert-butyl peroxy-3,3,5-trimethylhexanoate. Preferably, the above-mentioned antioxidant is a hindered phenol antioxidant or a phosphite antioxidant, including but not limited to pentaerythritol β(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, octadecyl β(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N,N'-bis[β(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl]hydrazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, tris(2,4-di-tert-butylphenol) phosphite, and bis(3,5-di-tert-butylphenyl) pentaerythritol diphosphite. Preferably, the above-mentioned light stabilizer is a hindered amine light stabilizer, including but not limited to 3,5-di-tert-butyl-4-hydroxy-benzoic acid hexadecyl ester, tris (1,2,2,6,6-pentamethyl-4-piperidinyl) phosphite, sebacate bis-2,2,6,6-tetramethylpiperidinol ester, bis-1-decyloxy-2,2,6,6-tetramethylpiperidin-4-ol sebacate, a polymer of succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol, a polymer of N,N'-bis (2,2,6,6-tetramethyl-4-piperidinyl) -1,6-hexanediamine and morpholine-2,4,6-trichloro-1,3,5-triazine. One or more. Preferably, the above-mentioned ultraviolet light absorber includes, but is not limited to, one or more of 2-hydroxy-4-n-octyloxybenzophenone, 2,2-tetramethylenebis(3,1-benzoxazine-4-one), 2-(2'-hydroxy-5-methylphenyl)benzotriazole, and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone. Preferably, the above-mentioned auxiliary crosslinking agent includes, but is not limited to, 1,3,5-triallyl-s-triazine-2,4,6-trione, N,N'-m-phenylbismaleimide, trimethylolpropane triacrylate, 1,2-polybutadiene, triallyl isocyanate, triallyl isocyanate, diallyl phthalate, triallyl cyanurate, and triallyl isocyanurate. Preferably, the above-mentioned heat stabilizer includes, but is not limited to, one or more of 2,2-methylene-bis-(4-methyl-6-tert-butyl)phenol, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl), 3,5-di-tert-butyl-4-hydroxy-benzoic acid hexadecyl ester, distearyl pentaerythritol diphosphite, and bisphenol A bis(diphenyl phosphate).

In order to further improve the white performance of the packaging film and meet the demand for high reflectivity of the film, in a preferred embodiment, the filler is selected from one or more of titanium dioxide, barium sulfate, bentonite, white carbon black, wollastonite, whisker silicon, talc, magnesium hydroxide, magnesium oxide, aluminum hydroxide, and aluminum oxide; preferably, the filler is a filler modified by one or more of silane coupling agent, titanate coupling agent, stearic acid, and palmitic acid. The modified filler is easier to disperse in the main resin and forms a better physical and/or chemical bond with the polymer component, the phases are more stable, and it is also more conducive to giving full play to the advantages of the components and improving the various application properties of the film.

Specifically, the main resin can be a common resin substrate in the art, and the main resin is selected from ethylene and vinyl acetate, propylene, butene, pentene, hexene, octene, methyl acrylate, methyl methacrylate, butadiene, 1,4-pentadiene, isoprene, ethylidene norbornene, dicyclopentadiene, 1,4-hexadiene binary or multi-copolymer, polyvinyl butyral, butadiene/isoprene and styrene block copolymer, natural rubber, trans-polyisoprene rubber. Preferably, the main resin is selected from EVA and/or POE. It should be noted here that by selecting EVA and/or POE as the main resin and combining the above-mentioned liquid rubber as a functional additive, the obtained film has better beneficial effects.

According to another aspect of the present invention, a method for preparing the aforementioned adhesive film is also provided. The method comprises the following steps: mixing the raw materials of the adhesive film, and then performing melt extrusion, film casting, and cooling to obtain the adhesive film; or sequentially performing melt extrusion, film casting, cooling, and pre-crosslinking to obtain the adhesive film, wherein the pre-crosslinking process adopts one or more of thermal crosslinking, ultraviolet crosslinking, and radiation crosslinking.

The adhesive film provided by the present invention has liquid rubber and filler added to the main resin. Liquid rubber has good flexibility, and is easy to be added to the main resin due to its liquid state and presents a good dispersion state therein, therefore, adding such rubber soft chain molecules can effectively reduce the hardness and storage modulus of the adhesive film surface. At the same time, the introduction of fillers not only maintains the excellent high reflectivity and other characteristics of the adhesive film itself, but also can use fillers to increase the stability of the three-dimensional network structure of the rubber soft chain molecules to a certain extent, so that the adhesive film can better maintain the microscopic morphology to the back-end process while being more flexible. Under the stress of subsequent processing or use, especially in the process of laminating with the battery cell, the adhesive film can better protect the battery cell and prevent the battery cell from cracking, thereby improving the yield of the photovoltaic module. Moreover, in the preparation process, the adhesive film is pre-crosslinked by one or more methods of thermal crosslinking, ultraviolet crosslinking, and radiation crosslinking, which effectively solves the fluidity problem of the colored encapsulation adhesive film, promotes the reduction of its surface fluidity, and does not cause white overflow and other problems during the later lamination process. After pre-crosslinking and finalization, the above-mentioned adhesive film can be further cut and rolled to obtain a finished product.

According to another aspect of the present invention, there is also provided a use of the above adhesive film as an adhesive film for encapsulating electronic devices, wherein the electronic devices are selected from photovoltaic modules, light-emitting semiconductor LEDs, organic light-emitting semiconductor OLEDs or display screens.

The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

Example 1

100 parts by weight of EVA (MFR: 11 g/10 min; VA content of 28% by weight), 10 parts by weight of titanium dioxide (DuPont R960), 1 part by weight of liquid polysulfide rubber, 0.01 parts by weight of PE wax, 0.3 parts by weight of crosslinking agent tert-butyl peroxy isopropyl carbonate, 0.01 parts by weight of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate pentaerythritol, 0.01 parts by weight of light stabilizer tris(1,2,2,6,6-pentamethyl-4-piperidinyl) phosphite and 0.02 parts by weight of The auxiliary cross-linking agent 1,3,5-triallyl-s-triazine-2,4,6-trione is fully mixed in a ribbon mixer and then extruded into a film by a single screw extruder with a T-die. The screw sleeve temperature gradually increases from 50°C to 80°C according to interval 2 to interval 10. The die temperature is set to 100°C. The film is embossed with an embossing roller and then cooled and rolled up. After cooling, it is transferred to the bottom of an electron irradiation device with an energy of 600keV. The film is irradiated with an electron beam at a dose of 30kGy. Finally, the film is rolled up to obtain the film E1. The thickness of E1 is 0.45mm, and the pre-crosslinking degree is 45%.

Among them, the viscosity of the liquid rubber at 23°C is 2000 pcs.

Example 2

The only difference from Example 1 is that the amount of liquid polysulfide rubber is replaced by liquid nitrile rubber, and a film E2 with a thickness of 0.45 mm is obtained. The viscosity of the liquid nitrile rubber at 23° C. is 2000 pcs.

Example 3

The only difference from Example 1 is that the amount of liquid polysulfide rubber is replaced by liquid silicone rubber, and a film E3 with a thickness of 0.45 mm is obtained. The viscosity of the liquid silicone rubber at 23° C. is 2000 pcs.

Example 4

The only difference from Example 1 is that the amount of liquid polysulfide rubber used is 0.5 parts by weight, and the obtained film E4 has a thickness of 0.45 mm. The viscosity of the liquid rubber at 23° C. is 2000 pcs.

Example 5

The only difference from Example 1 is that the amount of liquid polysulfide rubber used is 2.5 parts by weight, and a rubber film E5 with a thickness of 0.45 mm is obtained.

Example 6

The difference from Example 1 is that 100 parts by weight of EVA is replaced by POE (MFR: 10 g/10 min; octene content: 40 wt%) to obtain an adhesive film E6, which has a thickness of 0.45 mm.

Example 7

The only difference from Example 1 is that the amount of liquid polysulfide rubber used is 4 parts by weight, and a rubber film E7 with a thickness of 0.45 mm is obtained.

Example 8

The only difference from Example 1 is that the amount of liquid polysulfide rubber used is 5 parts by weight, and a rubber film E8 with a thickness of 0.45 mm is obtained.

Example 9

The only difference from Example 1 is that Example 9 is a transparent adhesive film, no titanium dioxide is added in the formula, and an adhesive film E9 with a thickness of 0.45 mm is obtained.

Comparative Example 1

The difference from Example 1 is that no liquid rubber and processing aid were added. A rubber film E10 was obtained.

Performance characterization:

1. Crosslinking degree

The degree of crosslinking before and after lamination is tested by the method of xylene heating extraction. The ratio of the mass not dissolved by xylene to the initial mass is the degree of crosslinking. The arithmetic mean of the three samples is taken as the degree of crosslinking of the film, in %. The degree of crosslinking before lamination (pre-crosslinking degree) is the degree of crosslinking of the packaging film directly extracted by xylene heating; the degree of crosslinking after lamination is the degree of crosslinking of the packaging film after lamination under the lamination conditions of 150°C and 18 minutes.

2. Appearance evaluation of double-glass modules with adhesive film

Use adhesive film to carry out single glass module encapsulation test, put glass/F406P (as front layer encapsulation material)/cell/encapsulation adhesive film of the present invention/back sheet into vacuum laminator in the order of glass/F406P (as front layer encapsulation material)/cell/encapsulation adhesive film of the present invention/back sheet, and cure at 145°C, first vacuumize and then pressurize, and cure for 18 minutes in total. Observe the appearance of double glass modules such as assembling and cracking. Hidden cracks are confirmed by EL test. Peel strength with back sheet is tested according to GB/T31034-2014.

3. Reflectivity

After laminating the film at 145°C for 8 minutes, the test was performed according to GB/T 13452.3-92.

4. Shore hardness A

After laminating the film at 145°C for 8 minutes, the test was performed according to GBT2411-2008 standard.

5. Storage modulus

After laminating the film at 145°C for 8 minutes, the test was performed according to ASTM E2254-2009.

The test results are shown in Table 1:

Table 1

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (13)

1. A film, characterized in that after lamination, the Shore A hardness of the film is less than 80; the storage modulus of the film at 40°C is less than 10MPa, the storage modulus at 60°C is less than 4MPa, and the storage modulus at 85°C is less than 1.3MPa; during the lamination process, the treatment temperature is 130-170°C, and the treatment time is 5-30min; the crosslinking degree of the film is greater than 80%, and the peel strength with the back sheet is greater than 40N/cm; the film comprises a main The adhesive film comprises 100 parts of the main resin, 0 to 50 parts of the filler and 0.5 to 5 parts of the functional additives; the adhesive film further comprises a processing aid dispersed in the main resin, and the processing aid is a polymer dispersant with a melting point below 110°C. 2 . The adhesive film according to claim 1 , characterized in that the adhesive film is a transparent adhesive film or a colored adhesive film. 3 . The adhesive film according to claim 1 , characterized in that the colored adhesive film is preferably a white adhesive film. 4 . The adhesive film according to claim 1 , wherein the liquid rubber is selected from one or more of liquid polysulfide rubber, liquid nitrile rubber, and liquid silicone rubber. 5. The adhesive film according to any one of claims 1 to 3, characterized in that the polymer dispersant is selected from one or more of polyethylene wax, polypropylene wax, silicone wax, ethylene-propylene copolymer, hexenyl bisstearamide, stearic acid monoglyceride, tristearic acid glyceride, liquid paraffin, microcrystalline paraffin, barium stearate, cadmium stearate, magnesium stearate, and copper stearate. 6 . The adhesive film according to claim 1 , wherein the amount of the processing aid added is 0.01 to 1% of the weight of the main resin. 7. The adhesive film according to claim 1 is characterized in that the adhesive film also includes an encapsulation aid dispersed in the main resin, and the encapsulation aid is selected from one or more of a cross-linking agent, a co-cross-linking agent, a heat stabilizer, a light stabilizer, an antioxidant, and an ultraviolet light absorber. 8 . The adhesive film according to claim 7 , wherein the amount of the encapsulation aid added is 0.01 to 1% of the weight of the main resin. 9. The adhesive film according to claim 1, characterized in that the filler is selected from one or more of titanium dioxide, barium sulfate, bentonite, white carbon black, wollastonite, whisker silicon, talc, magnesium hydroxide, magnesium oxide, aluminum hydroxide, and aluminum oxide. 10 . The adhesive film according to claim 9 , wherein the filler is a filler modified by one or more of a silane coupling agent, a titanate coupling agent, stearic acid, and palmitic acid. 11. The adhesive film according to claim 9, characterized in that the main resin is selected from EVA and/or POE. 12. A method for preparing the adhesive film according to any one of claims 1 to 11, characterized in that the method comprises the following steps: The raw materials of the adhesive film are mixed, and then melt-extruded, cast into film, and cooled to obtain the adhesive film; or melt-extruded, cast into film, cooled, and pre-crosslinked are sequentially performed to obtain the adhesive film, wherein the pre-crosslinking process adopts one or more of thermal crosslinking, ultraviolet crosslinking, and radiation crosslinking. 13. Use of the adhesive film according to any one of claims 1 to 11 as an adhesive film for encapsulating electronic devices, wherein the electronic devices are selected from photovoltaic modules, light-emitting semiconductor LEDs, organic light-emitting semiconductor OLEDs or display screens.