Packaging adhesive film, preparation method and photovoltaic module

Abstract

The invention belongs to the technical field of photovoltaic products, and particularly relates to a packaging adhesive film, a preparation method and a photovoltaic module. The invention provides a packaging adhesive film. The packaging adhesive film is prepared from the following raw materials: a polyolefin elastomer, an initiator, a cross-linking agent, a silane coupling agent, an antioxidant, an ultraviolet absorber and a lubricant, the preparation raw materials also comprise a functionalized polyolefin elastomer with the relative grafting ratio of 0.1-1 wt%. The invention further provides a preparation method of the packaging adhesive film. The invention further provides a photovoltaic module. In the technical scheme provided by the invention, the polyolefin elastomer is subjected to graft modification through the silane coupling agent, and the functionalized polyolefin elastomer is introduced, so that the intermolecular interaction force between the adhesive film and the backboard material is promoted, and the peel strength is improved; the technical defect that in the prior art, a photovoltaic packaging adhesive film is low in peel strength is overcome.

Description

Technical Field

[0001] This application belongs to the technical field of photovoltaic products, and particularly relates to a packaging adhesive film, a preparation method and a photovoltaic module. Background Art

[0002] The photovoltaic packaging adhesive film is the core packaging material of solar photovoltaic modules, mainly used for bonding solar cells with glass and backsheets, playing a key role in protecting the solar cells and extending the life of the modules.

[0003] In the prior art, common photovoltaic packaging adhesive film materials include ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), etc. Although these materials have good adhesion performance with glass, the peel strength between the adhesive and the adhesive film and the backsheet is relatively low, which cannot meet the actual use requirements and generally needs to be modified before use.

[0004] Therefore, developing a packaging adhesive film, a preparation method and a photovoltaic module to solve the technical defect of low peel strength of photovoltaic packaging adhesive films in the prior art has become an urgent problem for those skilled in the art. Summary of the Invention

[0005] Based on this, it is necessary to provide a packaging adhesive film, a preparation method and a photovoltaic module for solving the technical defect of low peel strength of photovoltaic packaging adhesive films in the prior art.

[0006] This application provides a packaging adhesive film, and the preparation raw materials of the packaging adhesive film include: polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet light absorber and lubricant;

[0007] The preparation raw materials further include a functionalized polyolefin elastomer with a relative grafting rate of 0.1% - 1 wt%.

[0008] In one embodiment, the preparation raw materials further include a functionalized polyolefin elastomer with a relative grafting rate of 0.2 wt%, 0.3 wt% or 0.4 wt%.

[0009] In one embodiment, based on parts by mass, the raw materials of the packaging adhesive film include: 100 parts of polyolefin elastomer, 5 - 40 parts of functionalized polyolefin elastomer, 0.05 - 2 parts of initiator, 0.05 - 2 parts of crosslinking agent, 0.5 - 10 parts of silane coupling agent, 0.05 - 10 parts of antioxidant, 0.05 - 10 parts of ultraviolet light absorber and 0.05 - 10 parts of lubricant.

[0010] In one embodiment, based on parts by mass, the raw materials of the encapsulation adhesive film include: 100 parts of polyolefin elastomer, 10 to 30 parts of functionalized polyolefin elastomer, 0.1 to 1 part of initiator, 0.1 to 1 part of crosslinking agent, 0.5 to 5 parts of silane coupling agent, 0.1 to 5 parts of antioxidant, 0.1 to 5 parts of ultraviolet light absorber, and 0.1 to 5 parts of lubricant.

[0011] In one embodiment, the functionalized polyolefin elastomer includes any one or more of MAH-g-POE (maleic anhydride grafted POE), GMA-g-POE (glycidyl methacrylate grafted POE), AA-g-POE (acrylic acid grafted POE), MMA-g-POE (methyl methacrylate grafted POE), and epoxy group grafted POE.

[0012] In one embodiment, the crosslinking agent includes any one or more of triallyl isocyanurate, triallyl cyanurate, triallyl hydrouracil, trimethylolpropane trimethacrylate, ethoxylated pentaerythritol tetraacrylate, and ethoxylated trimethylolpropane triacrylate.

[0013] In one embodiment, the initiator is a peroxide, and the initiator includes any one or more of tert-butyl peroxy-2-ethylhexyl carbonate, tert-butyl peroxy-2-ethylhexanoate, diisopropyl peroxydicarbonate, tert-butyl cumyl peroxide, dicumyl peroxide, tert-amyl peroxy-2-ethylhexyl carbonate, and benzoyl peroxide;

[0014] and / or, the silane coupling agent includes any one or more of vinyltrimethoxysilane, vinyldimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinylmethyldimethoxysilane, and γ-aminopropyltriethoxysilane;

[0015] and / or, the antioxidant includes one or more of antioxidant 1010, antioxidant 1076, antioxidant 168, antioxidant 626, and antioxidant 2246;

[0016] and / or, the ultraviolet light absorber includes one or more of ultraviolet light absorber UV-531, ultraviolet light absorber UV-326, ultraviolet light absorber UV-P, and ultraviolet light absorber UV-O;

[0017] and / or, the lubricant includes one or more of stearic acid, calcium stearate, zinc stearate, and butyl stearate.

[0018] This application also provides a preparation method of an encapsulation adhesive film including any one of the above, and the method includes:

[0019] Step 1: Mixing. Mix polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet absorber and lubricant to obtain a first product.

[0020] Step 2: Extrusion. Extrude the first product to obtain a second product.

[0021] Step 3: Hot pressing. Hot press the second product to obtain the product.

[0022] In one embodiment, in Step 1, the temperature of the mixing is 10 - 50°C and the time of the mixing is 8 - 20 h.

[0023] In one embodiment, in Step 1, the temperature of the mixing is 20 - 40°C and the time of the mixing is 10 - 16 h.

[0024] In one embodiment, in Step 2, the temperature of the extrusion is 60 - 140°C.

[0025] In one embodiment, in Step 2, the temperature of the extrusion is 70 - 100°C.

[0026] In one embodiment, in Step 3, the temperature of the hot pressing is 100 - 180°C and the time of the hot pressing is 50 - 100 s.

[0027] In one embodiment, in Step 3, the temperature of the hot pressing is 110 - 150°C and the time of the hot pressing is 60 - 80 s.

[0028] This application also provides a photovoltaic module, including: the encapsulation adhesive film described in any one of the above or the product obtained by any one of the preparation methods described above.

[0029] In one embodiment, the photovoltaic module includes: a glass layer, a cell layer and a backsheet material layer stacked in sequence, and the glass layer and the cell layer and / or the cell layer and the backsheet material layer are bonded by the encapsulation adhesive film.

[0030] In one embodiment, the bonding method includes: laminating the glass layer, the encapsulation adhesive film, the cell layer, the encapsulation adhesive film and the backsheet material layer at 100 - 180°C for 5 - 60 min.

[0031] In one embodiment, the bonding method includes: laminating the glass layer, the encapsulation adhesive film, the cell layer, the encapsulation adhesive film and the backsheet material layer at 110 - 150°C for 5 - 30 min.

[0032] In one embodiment, the application amount of the encapsulation adhesive film is 0.1 - 0.5 kg / m2 。

[0033] In one embodiment, the application amount of the encapsulation adhesive film is 0.2 - 0.4 kg / m 2 。

[0034] In summary, the present application provides an encapsulation adhesive film, including: polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet light absorber, and lubricant; the preparation raw materials further include a functionalized polyolefin elastomer with a relative grafting rate of 0.1% - 1 wt%. The present application also provides a preparation method including the above encapsulation adhesive film, and the present application also provides a photovoltaic module. In the technical solution provided by the present application, the polyolefin elastomer is graft-modified by a silane coupling agent to introduce a functionalized polyolefin elastomer, which promotes the intermolecular interaction force between the adhesive film and the backplane material and improves the peel strength; it solves the technical defect that the photovoltaic encapsulation adhesive film has a low peel strength in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0036] Figure 1 It is a schematic flow chart of a method for preparing an encapsulation adhesive film in the technical solution provided by the embodiments of the present application;

[0037] Figure 2 It is a schematic diagram of the result of the infrared spectrum test in Experimental Example 2 in the technical solution provided by the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The embodiments of the present application provide an encapsulation adhesive film, a preparation method, and a photovoltaic module, which are used to solve the technical defect that the photovoltaic encapsulation adhesive film has a low peel strength in the prior art, and have become a problem that needs to be solved urgently by those skilled in the art.

[0039] In order to make the above objects, features, and advantages of the present application more obvious and understandable, the following will give a detailed description of the specific embodiments of the present application with reference to the drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0040] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present application.

[0041] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0042] In the present application, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0043] In the present application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0044] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0045] The following examples will be combined with Figure 1 to specifically prepare a photovoltaic encapsulation film and a photovoltaic module. In the examples of this application, the functionalized polyolefin elastomers are all commercially available conventional products.

[0046] Example 1

[0047] This example is a specific example for preparing encapsulation film product 1 and photovoltaic module 1.

[0048] In this example, by mass, the raw materials include: 100 parts of POE resin (using the PV8660 polyolefin elastomer of commercially available Dow Chemical, the same in other examples), 10 parts of AA-g-POE (functionalized polyolefin elastomer, purchased from Mitsui Chemicals), 0.3 part of tert-butyl peroxy-2-ethylhexyl carbonate (initiator), 0.2 part of triallyl isocyanurate (crosslinking agent), 2 parts of vinyltrimethoxysilane (silane coupling agent), 0.1 part of antioxidant 1010 (antioxidant), 0.1 part of antioxidant 168 (antioxidant), 0.1 part of ultraviolet absorber UV-770 (ultraviolet absorber), and 0.1 part of calcium stearate (lubricant).

[0049] The preparation method of the encapsulation film is as follows:

[0050] Step 1: Mix POE, functionalized polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet absorber and lubricant at 30 °C for 12 h to obtain the first product 1;

[0051] Step 2: Extrude the first product 1 at 110 °C to obtain the second product 1;

[0052] Step 3: Hot press the second product 1 at 140 °C for 120 s to obtain the encapsulation film product 1;

[0053] Step 4: Laminate the glass layer, the encapsulation film product 1, the battery cell, the encapsulation film product 1 and the photovoltaic backplane at 140 °C for 18 min to obtain the photovoltaic module 1.

[0054] Example 2

[0055] This embodiment is a specific embodiment for preparing the encapsulation film product 2 and the photovoltaic module 2.

[0056] In this embodiment, by mass, the raw materials include: 100 parts of POE resin (polyolefin elastomer), 20 parts of MMA-g-POE (functionalized polyolefin elastomer, purchased from ExxonMobil), 0.6 parts of tert-butyl peroxy-2-ethylhexyl carbonate (initiator), 0.4 parts of triallyl isocyanurate (crosslinking agent), 2 parts of vinyltrimethoxysilane (silane coupling agent), 0.1 part of antioxidant 1010 (antioxidant), 0.1 part of antioxidant 168 (antioxidant), 0.1 part of ultraviolet absorber UV-770 (ultraviolet absorber)

[0057] and 0.1 part of calcium stearate (lubricant).

[0058] The preparation method of the above encapsulation film is as follows:

[0059] Step 1: Mix POE, functionalized polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet absorber and lubricant at 30°C for 12 h to obtain the first product 2;

[0060] Step 2: Extrude the first product 2 at 110°C to obtain the second product 2;

[0061] Step 3: Hot press the second product 2 at 140°C for 120 s to obtain the encapsulation film product 2;

[0062] Step 4: Laminate the glass layer, the encapsulation film product 2, the battery chip, the encapsulation film product 2 and the photovoltaic backplane at 140°C for 18 min to obtain the photovoltaic module 2.

[0063] Example 3

[0064] This embodiment is a specific embodiment for preparing the encapsulation film product 3 and the photovoltaic module 3.

[0065] In this embodiment, by mass, the raw materials include: 100 parts of POE resin (polyolefin elastomer), 20 parts of GMA-g-POE (functionalized polyolefin elastomer, purchased from Dow), 0.6 parts of tert-butyl peroxy-2-ethylhexyl carbonate (initiator), 0.4 parts of triallyl isocyanurate (crosslinking agent), 5 parts of vinyltrimethoxysilane (silane coupling agent), 0.1 part of antioxidant 1010 (antioxidant), 0.1 part of antioxidant 168 (antioxidant), 0.1 part of ultraviolet absorber UV-770 (ultraviolet absorber) and 0.1 part of calcium stearate (lubricant).

[0066] The preparation method of the above encapsulation film is as follows:

[0067] Step 1: Mix POE, functionalized polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet light absorber and lubricant at 30 °C for 12 h to obtain the first product 3;

[0068] Step 2: Extrude the first product 3 at 110 °C to obtain the second product 3;

[0069] Step 3: Hot press the second product 3 at 140 °C for 120 s to obtain the encapsulation film product 3;

[0070] Step 4: At 140 °C, laminate the glass layer with the encapsulation film product 3, the battery chip, and the encapsulation film product 3 with the photovoltaic backplane for 18 min to obtain the photovoltaic module 3.

[0071] Example 4

[0072] This example is a specific example for preparing the encapsulation film product 4 and the photovoltaic module 4.

[0073] In this example, by mass, the raw materials include: 100 parts of POE resin (polyolefin elastomer), 0.6 parts of tert-butyl peroxy-2-ethylhexyl carbonate (initiator), 0.4 parts of triallyl isocyanurate (crosslinking agent), 5 parts of vinyltrimethoxysilane (silane coupling agent), 20 parts of MAH-g-POE (functionalized polyolefin elastomer, purchased from Mitsui Chemicals), 0.1 part of antioxidant 1010 (antioxidant), 0.1 part of antioxidant 168 (antioxidant), 0.1 part of ultraviolet light absorber UV-770 (ultraviolet light absorber), and 0.1 part of calcium stearate (lubricant).

[0074] The preparation method of the above encapsulation film is as follows:

[0075] Step 1: Mix POE, functionalized polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet light absorber and lubricant at 30 °C for 12 h to obtain the first product 4;

[0076] Step 2: Extrude the mixture at 110 °C and extrude the first product 4 to obtain the second product 4;

[0077] Step 3: Hot press the second product 4 at 140 °C for 120 s to obtain the encapsulation film product 4;

[0078] Step 4: At 140 °C, laminate the glass layer with the encapsulation film product 4, the battery chip, and the encapsulation film product 4 with the photovoltaic backplane for 18 min to obtain the photovoltaic module 4.

[0079] Example 5

[0080] This example is a specific example for preparing the encapsulation film product 5 and the photovoltaic module 5.

[0081] In this embodiment, by mass, the raw materials include: 100 parts of POE resin (polyolefin elastomer), 0.6 parts of tert-butyl peroxy-2-ethylhexyl carbonate (initiator), 0.4 parts of triallyl isocyanurate (crosslinking agent), 5 parts of vinyltrimethoxysilane (silane coupling agent), 40 parts of MAH-g-POE (functionalized polyolefin elastomer, purchased from Mitsui Chemicals), 0.1 part of antioxidant 1010 (antioxidant), 0.1 part of antioxidant 168 (antioxidant), 0.1 part of ultraviolet absorber UV-770 (ultraviolet absorber), and 0.1 part of calcium stearate (lubricant).

[0082] The preparation method of the above encapsulation adhesive film is as follows:

[0083] Step 1: Mix POE, functionalized polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet absorber, and lubricant at 30°C for 12 h to obtain the first product 5;

[0084] Step 2: Extrude the first product 5 at 110°C to obtain the second product 5;

[0085] Step 3: Hot press the second product 5 at 140°C for 120 s to obtain the encapsulation adhesive film product 5;

[0086] Step 4: Laminate the glass layer, the encapsulation adhesive film product 5, the battery cell, and the encapsulation adhesive film product 5 with the photovoltaic backplane at 140°C for 18 min to obtain the photovoltaic module 5.

[0087] Comparative Example 1

[0088] This comparative example provides a photovoltaic encapsulation adhesive film for backplane and its preparation method. The difference from Example 1 is only that the initiator and crosslinking agent are not added, and other conditions are the same as those in Example 1.

[0089] Comparative Example 2

[0090] This comparative example provides a photovoltaic encapsulation adhesive film for backplane and its preparation method. The difference from Example 3 is only that the functionalized polyolefin elastomer is not added, and other conditions are the same as those in Example 3.

[0091] Comparative Example 3

[0092] This comparative example provides a photovoltaic encapsulation adhesive film for backplane and its preparation method. The difference from Example 1 is only that the lamination time is 5 min, and other conditions are the same as those in Example 1.

[0093] Comparative Example 4

[0094] This comparative example provides a photovoltaic encapsulation film for a backsheet and a preparation method thereof. The difference from Example 5 is only that vinyltrimethoxysilane is not added, and other conditions are the same as those in Example 5.

[0095] Comparative Example 5

[0096] This comparative example provides a photovoltaic encapsulation film for a backsheet and a preparation method thereof. The difference from Example 5 is only that the lamination time is 5 min, and other conditions are the same as those in Example 5.

[0097] Experimental Example 1

[0098] This experimental example is an experimental example for testing the gel content.

[0099] The gel content of the sample was determined by the hot solvent heating extraction method. The specific operation method was as follows: Take 0.2 g of the encapsulation film sample, wrap it with filter paper, then add an excessive amount of xylene (about 200 mL), heat and reflux at 140 °C for more than 7 h, then take out the sample and dry it in an oven at 100 °C for 24 h (to constant weight), and calculate the insoluble content by the weight loss method. The gel content test results are shown in Table 1.

[0100] Table 1

[0101]

[0102] As can be seen from Table 1, the increase in the initiator dosage and crosslinking agent dosage in Example 2 will increase the gel content of the film. The increase in the vinyltrimethoxysilane dosage in Example 3 will further increase the gel content. For the samples with no initiator and vinyltrimethoxysilane added as a control (Comparative Example 1 and Comparative Example 4), the system cannot form an effective crosslinked network, and the gel content is low. If the lamination time is 5 min (Comparative Example 3 and Comparative Example 5), due to the short reaction time and incomplete reaction, the crosslinked network is not fully formed, and the gel content is low.

[0103] Experimental Example 2

[0104] This experimental example is an experimental example for infrared spectroscopy testing.

[0105] The samples prepared in Example 3 and Comparative Example 2 were subjected to Soxhlet extraction with xylene at 140 °C for more than 7 h to remove small molecules in the film. After drying, the samples were subjected to infrared spectroscopy testing, and the results are as Figure 2 shown.

[0106] From Figure 2 it can be seen that compared with the sample prepared in Comparative Example 2, the sample prepared in Example 3 showed an Si-O-Si bond at 1790 cm -1 . This indicates that when the extrusion temperature is 110 °C, vinyltrimethoxysilane has been successfully grafted onto the POE molecular chain.

[0107] Experimental Example 3

[0108] This experimental example is for the measurement of light transmittance and volume resistivity. Among them, the light transmittance was measured in accordance with GB / T 2410-2008 Determination of Transmittance and Haze of Transparent Plastics; the volume resistivity was measured in accordance with GB / T 1401-2006 Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials.

[0109] The samples prepared in the examples were tested for light transmittance and volume resistivity, and the test results are shown in Table 2.

[0110] Table 2

[0111]

[0112] As can be seen from Table 2, the introduction of functionalized polyolefin will lead to a decrease in light transmittance, but the light transmittance is still at a relatively high level, which can better meet the use requirements of photovoltaic modules. At the same time, the introduction of functionalized polyolefin does not cause a significant decrease in the volume resistivity of the adhesive film, indicating that the adhesive film has good electrical insulation properties.

[0113] Experimental Example 4

[0114] The samples prepared in Example 2, Example 3, Example 4, Example 5 and Comparative Example 1, Comparative Example 2, Comparative Example 4, Comparative Example 5 were tested for peel strength. The peel strength was tested with reference to 《GB / T29848-2018》. The test results are shown in Table 3.

[0115] Table 3

[0116]

[0117]

[0118] As can be seen from Table 3, the introduction of functionalized polyolefin can effectively improve the peel strength of the adhesive film (Comparative Example 2). Although the introduction of vinyltrimethoxysilane can improve the peel strength between the adhesive film and the backsheet, the significant increase in peel strength is not caused by the grafting of vinyltrimethoxysilane (Comparative Example 4). When the lamination time is short (Comparative Example 5), the reaction time of the system is short, and the bonding strength between the adhesive film and the backsheet is low, and the improvement effect is not obvious.

[0119] From the above, it can be concluded that the technical solutions provided in the embodiments of the present application have the following advantages:

[0120] (1) In the technical solution provided by the embodiment of the present application, by introducing a functionalized polyolefin elastomer, the intermolecular interaction between the adhesive film and the backsheet material is effectively promoted, and the bonding ability between the adhesive film and the backsheet material is significantly improved. After testing, the initial peel strength of this photovoltaic encapsulation adhesive film can reach 66.4 N / cm 2 , providing a solid guarantee for the stable operation of photovoltaic modules under extreme climatic conditions.

[0121] (2) In the technical solution provided by the embodiment of the present application, the POE is graft-modified by a silane coupling agent. After modification, the crosslinking efficiency of the adhesive film is greatly improved. When the lamination time is 18 minutes, the gel content of the adhesive film is as high as 76.63%, indicating that its crosslinked structure is stable and dense.

[0122] (3) In the technical solution provided by the embodiment of the present application, the prepared photovoltaic encapsulation adhesive film has excellent light transmittance and electrical insulation properties. The test results show that the light transmittance of this adhesive film can reach 92%, which can fully ensure the photoelectric conversion efficiency of photovoltaic modules. At the same time, its volume resistivity is 2.26×10 14 , having high electrical insulation properties, further improving the safety and reliability of photovoltaic modules.

[0123] In summary, the present application provides an encapsulation adhesive film, including: polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet light absorber, and lubricant; the preparation raw materials further include a functionalized polyolefin elastomer with a relative grafting rate of 0.1% - 1 wt%. The present application also provides a preparation method including the above encapsulation adhesive film, and the present application also provides a photovoltaic module. In the technical solution provided by the present application, the polyolefin elastomer is graft-modified by a silane coupling agent, and a functionalized polyolefin elastomer is introduced to promote the intermolecular interaction between the adhesive film and the backsheet material, and improve the peel strength; solving the technical defect of low peel strength existing in the prior art for photovoltaic encapsulation adhesive films.

[0124] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification. At the same time, other embodiments can be derived from the above embodiments, so that structural and logical substitution and change can be carried out without departing from the scope of the present disclosure.

[0125] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A packaging film, wherein the raw materials for preparing the packaging film include: Polyolefin elastomer, initiator, crosslinking agent, silane coupling agent, antioxidant, ultraviolet light absorber and lubricant; The method is characterized in that the raw materials for preparation also include a functionalized polyolefin elastomer with a relative grafting rate of 0.1% to 1wt%.

2. The packaging film according to claim 1, characterized in that: The raw materials of the packaging film include, by mass, 100 parts of polyolefin elastomer, 5-40 parts of functionalized polyolefin elastomer, 0.05-2 parts of initiator, 0.05-2 parts of cross-linking agent, 0.5-10 parts of silane coupling agent, 0.05-10 parts of antioxidant, 0.05-10 parts of ultraviolet light absorber and 0.05-10 parts of lubricant.

3. The packaging film according to claim 1 or 2, characterized in that: The functionalized polyolefin elastomer includes any one or more of MAH-g-POE, GMA-g-POE, AA-g-POE, MMA-g-POE and epoxy group-grafted POE.

4. The packaging film according to claim 1 or 2, characterized in that: The crosslinking agent includes any one or more of triallyl isocyanurate, triallyl cyanurate, triallyl hydrourate, trimethylolpropane trimethacrylate, ethoxylated pentaerythritol tetraacrylate and ethoxylated trimethylolpropane triacrylate.

5. The packaging film according to claim 1 or 2, characterized in that: The initiator is a peroxide, and the initiator includes any one or more of tert-butyl peroxy-2-ethylhexyl carbonate, tert-butyl peroxy-2-ethylhexanoate, diisopropyl peroxydicarbonate, tert-butyl cumyl peroxide, diisopropyl peroxide, tert-amyl peroxy-2-ethylhexyl carbonate, and dibenzoyl peroxide; And / or, the silane coupling agent includes any one or more of vinyltrimethoxysilane, vinyldimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinylmethyldimethoxysilane and γ-aminopropyltriethoxysilane; and / or, the antioxidant comprises: one or more of antioxidant 1010, antioxidant 1076, antioxidant 168, antioxidant 626, and antioxidant 2246; And / or, the ultraviolet light absorber includes: one or more of ultraviolet light absorber UV-531, ultraviolet light absorber UV-326, ultraviolet light absorber UV-P and ultraviolet light absorber UV-O; And / or, the lubricant includes: one or more of stearic acid, calcium stearate, zinc stearate and butyl stearate.

6. A method for preparing the encapsulation film according to any one of claims 1 to 5, characterized in that: The method comprises: Step 1: mixing: a polyolefin elastomer, an initiator, a cross-linking agent, a silane coupling agent, an antioxidant, an ultraviolet light absorber and a lubricant to obtain a first product; Step 2: extrusion, extruding the first product to obtain a second product; Step three, hot pressing, hot pressing the second product to obtain a product.

7. The preparation method according to claim 6, characterized in that: In step 1, the mixing temperature is 10 to 50° C., and the mixing time is 8 to 20 hours.

8. The preparation method according to claim 6, characterized in that: In step 2, the extrusion temperature is 60-140°C.

9. The preparation method according to claim 6, characterized in that: In step three, the temperature of the hot pressing is 100-180° C., and the time of the hot pressing is 60-80 seconds.

10. A photovoltaic module, comprising the encapsulation film according to any one of claims 1 to 5 or the product obtained by the preparation method according to any one of claims 6 to 9.

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