Sealant, photovoltaic module and encapsulation method thereof, electronic component

Abstract

The application provides a sealing glue, a photovoltaic module and a packaging method thereof, and an electronic component. The sealing glue comprises 30-40 parts of butyl rubber, 10-30 parts of polyisobutylene, 10-35 parts of a desiccant, 1-15 parts of a filler, and 0.02-0.2 parts of a titanate coupling agent, wherein the general structure of the titanate coupling agent is (RO) m -Ti(OX-R'-Y) n , m is any one integer in 1-4, n is an integer, n=6-m, R is a C1-C 10 alkyl, X is selected from any one element in C, N, P and S, R' is a C8 alkyl or above, and Y is selected from any one of a hydroxyl, an amino and a double bond. The sealing glue is used for sealing an opening of the photovoltaic module, can effectively block the opening from being eroded by external environment water vapor, and can also solve the insufficient insulation and appearance defects caused by the bubbles at the opening during lamination.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic technology, and more specifically, to a sealant, a photovoltaic module and its encapsulation method, and electronic components. Background Technology

[0002] In recent years, the development of renewable energy has accelerated, especially the photovoltaic industry. Technological innovation across the photovoltaic industry chain is rapidly advancing. High-efficiency bifacial half-cell PERC technology is now the mainstream, while new high-efficiency bifacial half-cell technologies such as TOPCon and HJT are also showing strong growth momentum, with many photovoltaic module manufacturers launching new products.

[0003] However, the application of high-efficiency cell technologies such as TOPCon and HJT places high demands on other component materials, such as encapsulation films, backsheets, connectors, and edge sealing materials. This is partly because the thinning of these high-efficiency cells makes them more fragile, and partly because the advancements in high-efficiency cell manufacturing technology have increased the cells' sensitivity to the environment, especially moisture. Glass is generally used as the backsheet material for high-efficiency photovoltaic modules, primarily because glass has high moisture barrier properties, effectively reducing quality failures caused by external moisture. Therefore, photovoltaic module structures typically employ a top-to-bottom stacking of glass, front encapsulation film, cells, back encapsulation film, and back to glass. Simultaneously, to maximize module area and increase light utilization, miniaturization of junction boxes is increasingly popular, with the use of 2-4 flat, narrow, separate junction boxes replacing the original large, wide junction box becoming more widespread. Multiple holes are needed at the junction box's connection to the back of the module to facilitate the passage of busbars. For installation configurations with 2 to 4 flat and narrow split-type junction boxes, the number of lead-out holes on the back of the junction box increases from 1 to 2 to 4. Furthermore, the holes (round, square, etc.) are generally pre-drilled into the back glass panel, so the hole thickness is consistent with the back glass panel thickness.

[0004] During component lamination, the absence of backsheet glass at the hole locations can cause the adhesive film in these areas to overflow and distribute unevenly, leading to issues such as bubbles and thinning. Junction boxes are typically fixed using silicone adhesive. Existing silicone sealants have good adhesion and low water absorption, but their moisture barrier properties are weak, with a moisture permeability exceeding 5g / m². 2 If applied to the bonding and sealing of the junction box holes of moisture-sensitive high-efficiency battery modules, it will pose a significant risk of moisture intrusion.

[0005] Therefore, the sealing material for the junction box holes of these high-efficiency battery modules has become a major hidden danger to the long-term reliability of photovoltaic modules, and it is increasingly important to develop a good protective solution.

[0006] Therefore, the development of a photovoltaic sealant for the holes of high-efficiency battery modules can enhance the weather resistance and barrier properties of the holes, as well as solve the problem of poor appearance. This is of great significance for improving the yield rate of high-efficiency battery modules and increasing long-term reliability, and is the most urgent issue to be solved in the photovoltaic encapsulation materials industry. Summary of the Invention

[0007] The main objective of this invention is to provide a sealant, a photovoltaic module and its encapsulation method, and electronic components to solve the problem of poor long-term reliability of photovoltaic modules caused by external water vapor seeping into the openings in the prior art.

[0008] To achieve the above objectives, according to one aspect of the present invention, a sealant is provided, comprising, by weight, 30-40 parts of butyl rubber, 10-30 parts of polyisobutylene, 10-35 parts of a desiccant, 1-15 parts of a filler, and 0.02-0.2 parts of a titanate coupling agent, wherein the titanate coupling agent has the general structural formula (RO). m -Ti(OX-R'-Y) n m is any integer from 1 to 4, n is an integer, and n = 6 - m, R is a sequence of numbers from C1 to C2. 10 The alkane group, X is selected from any element of C, N, P, S, R' is a C8 or larger alkane group, and Y is selected from any element of hydroxyl, amino, or double bond.

[0009] Furthermore, R is a C1 to C4 alkane group, preferably R' is a C8 to C4 alkane group. 20 alkane group.

[0010] Furthermore, the mass ratio of butyl rubber to polyisobutylene is 1 to 4:1; preferably, the degree of unsaturation of the butyl rubber is 0.1 to 2.1%, preferably, the number average molecular weight of the butyl rubber is 5,000 to 500,000, and preferably, the number average molecular weight of the polyisobutylene is 1,000 to 200,000.

[0011] Further, the particle size of the above-mentioned desiccant is 0.1-10 μm, and preferably the desiccant is selected from any one or more of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, anhydrous calcium chloride, and anhydrous magnesium sulfate; preferably the desiccant is a combination of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve, and further preferably the mass ratio of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve is 1:1-10:0.5-1; preferably the particle size of the filler is 0.01-0.5 μm, and preferably the filler is selected from any one or more of fumed silica, carbon black, silica, talc, mica, magnesium silicate, alumina and calcium carbonate.

[0012] Furthermore, the sealant further includes 1 to 15 parts of a composite resin, preferably selected from copolymers of propylene, butene, pentene, hexene, octene, norbornene, and styrene with ethylene, or polyethylene and polypropylene, preferably grafted with silane and / or maleic anhydride; preferably, the sealant also includes 0.01 to 5 parts of additives, preferably selected from antioxidants and / or light stabilizers, preferably selected from aromatic amine antioxidants, hindered phenolic antioxidants, salicylate antioxidants, benzophenone antioxidants, and triazine antioxidants, preferably a hindered amine light stabilizer.

[0013] Furthermore, the water vapor permeability of the above-mentioned sealant is ≤10%. -1 g / m 2 / 24h; the bonding strength between the sealant and the back glass of the photovoltaic module, and between the sealant and the junction box of the photovoltaic module, are each ≥10N / 10mm independently; the complex viscosity of the sealant at 150℃ is between 1000 and 100000 Pa·s, and the creep size of the sealant at 150℃ is ≤1mm.

[0014] According to another aspect of the present invention, a method for encapsulating a photovoltaic module is provided. The method includes: stacking a front glass layer, a front encapsulating film, a battery cell, a rear encapsulating film, and a rear glass layer to obtain a stacked module, wherein the rear glass layer has an opening, and the battery cells of the battery cell collect current through a busbar, the busbar passing through the opening to be electrically connected to a junction box; filling the remaining portion of the opening with an encapsulating material; attaching the junction box to the opening; and laminating the stacked module to obtain a photovoltaic module, wherein the encapsulating material includes the aforementioned sealant.

[0015] Further, the volume ratio of the filling material to the remaining portion of the opening is 1 to 1.5:1; preferably, the encapsulation material also includes silicone sealant, and the filling process preferably includes: coating a layer of silicone sealant on the inner wall of the opening to form a coated opening; injecting sealant into the coated opening, preferably the volume ratio of silicone sealant to sealant is 1 to 50:1, more preferably 5 to 50:1; further, preferably the silicone sealant is de-alcoholized silicone and / or deoxime-type silicone.

[0016] According to another aspect of the present invention, a photovoltaic module is provided, which is prepared by the above-described encapsulation method.

[0017] According to another aspect of the present invention, an electronic component is provided, which is any one of a liquid crystal panel, an electroluminescent device, a plasma display device, and a touch screen, and the power supply structure of the electronic component is a photovoltaic module, which is the aforementioned photovoltaic module.

[0018] Applying the technical solution of this invention, the butyl rubber and polyisobutylene of this application exhibit excellent weather resistance, heat resistance, and alkali resistance due to the dense arrangement of side methyl groups in their molecular chains, which restricts the thermal motion of the molecular chains and reduces their flexibility, resulting in trace crystallization. These structural features give butyl rubber and polyisobutylene excellent weather resistance, heat resistance, and alkali resistance, low air permeability, and good air tightness; their air permeability is an order of magnitude lower than that of natural rubber. The desiccant is an adsorbent substance used to adjust the moisture barrier properties of the sealant. The filler is a colorimetric or strength-reinforcing filler, playing a certain role in reinforcing the sealant. The titanate coupling agent interacts with the desiccant, coupling through chemical adsorption or chemical reaction between the RO groups and trace amounts of hydroxyl groups or protons on the surface of the desiccant. The long-chain alkane segments in OX-R'-Y assist in the winding and fixing of desiccants and fillers. X helps enhance the compatibility of inorganic fillers with polymer resins. The polar groups in Y undergo micro-crosslinking reactions with the unsaturated bonds in the polymer resin, resulting in a uniform and stable crosslinked structure between the polymer resin and inorganic fillers. This promotes the uniform mixing of inorganic particles (desiccants, fillers) and organic materials (butyl rubber and polyisobutylene), thus mitigating the cold flow of butyl rubber and polyisobutylene and reducing the degradation or migration of these materials, which leads to a decrease in the moisture barrier properties of the sealant. This further improves the moisture barrier properties of the sealant. When used to seal openings in photovoltaic modules, this sealant effectively prevents moisture erosion at the openings and solves the problems of insufficient insulation and appearance defects caused by air bubbles at the openings during lamination. This improves the long-term reliability of photovoltaic modules and the yield rate of the lamination process, resulting in photovoltaic modules with excellent overall performance. Furthermore, this sealant can be applied using equipment, enabling automated production lines. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0020] Figure 1 The diagram shows a top rear view of a half-cell double-glass module without a junction box according to Embodiment 1 of the present invention;

[0021] Figure 2 The rear top view of a half-cell double-glass module with a split junction box provided in Embodiment 1 of the present invention is shown;

[0022] Figure 3 The diagram shows a cross-sectional view of the sealing and bonding between the split junction box and the rear glass of a half-cell double-glass module according to Embodiment 1 of the present invention.

[0023] Figure 4This diagram shows a cross-sectional view of the sealing and bonding between the split junction box and the rear glass layer of a half-cell double-glass module according to Embodiment 2 of the present invention; and

[0024] Figure 5 A schematic diagram of a creep performance testing method provided by the present invention is shown.

[0025] The accompanying drawings include the following reference numerals:

[0026] 1. Rear glass; 2. Opening; 3. Junction box; 4. Sealant; 5. Silicone sealant; A. Top glass; B. Sealant; C. Bottom glass; D. Additional load. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] As analyzed in the background section, existing photovoltaic modules suffer from poor reliability during long-term service due to the infiltration of external water vapor into the openings. To solve this problem, the present invention provides a sealant, a photovoltaic module and its encapsulation method, and electronic components.

[0029] In a typical embodiment of this application, a sealant is provided, comprising, by weight: 30-40 parts butyl rubber, 10-30 parts polyisobutylene, 10-35 parts desiccant, 1-15 parts filler, and 0.02-0.2 parts titanate coupling agent, wherein the titanate coupling agent has the general structural formula (RO). m -Ti(OX-R'-Y) n m is any integer from 1 to 4, n is an integer, and n = 6 - m, R is a sequence of numbers from C1 to C2. 10 The alkane group, X is selected from any element of C, N, P, S, R' is a C8 or larger alkane group, and Y is selected from any element of hydroxyl, amino, or double bond.

[0030] The butyl rubber and polyisobutylene in this application exhibit microcrystals due to the dense arrangement of side methyl groups in their molecular chains, which restricts the thermal motion of the molecular chains and reduces their flexibility. These structural features give butyl rubber and polyisobutylene excellent weather resistance, heat resistance, and alkali resistance, as well as low air permeability and good air tightness; their air permeability is an order of magnitude lower than that of natural rubber. The desiccant is an adsorbent used to adjust the moisture barrier properties of the sealant, and the filler is a colorimetric or strength-reinforcing filler, providing a certain degree of sealant reinforcement. The titanate coupling agent interacts with the desiccant, achieving coupling through chemical adsorption or chemical reaction between the RO groups and trace amounts of hydroxyl groups or protons on the surface of the desiccant. The long-chain alkane segments in OX-R'-Y assist in the winding and fixing of desiccants and fillers. X helps enhance the compatibility of inorganic fillers with polymer resins. The polar groups in Y undergo micro-crosslinking reactions with the unsaturated bonds in the polymer resin, resulting in a uniform and stable crosslinked structure between the polymer resin and inorganic fillers. This promotes the uniform mixing of inorganic particles (desiccants, fillers) and organic materials (butyl rubber and polyisobutylene), thus mitigating the cold flow of butyl rubber and polyisobutylene and reducing the degradation or migration of these materials, which leads to a decrease in the moisture barrier properties of the sealant. This further improves the moisture barrier properties of the sealant. When used to seal openings in photovoltaic modules, this sealant effectively prevents moisture erosion at the openings and solves the problems of insufficient insulation and appearance defects caused by air bubbles at the openings during lamination. This improves the long-term reliability of photovoltaic modules and the yield rate of the lamination process, resulting in photovoltaic modules with excellent overall performance. Furthermore, this sealant can be applied using equipment, enabling automated production lines.

[0031] Preferably, R is a C1-C4 alkane group, and preferably R' is a C8-C4 alkane group. 20 The alkane groups allow for a more uniform mixing of inorganic particles (desiccant, filler) and organic materials (butyl rubber and polyisobutylene).

[0032] To further enhance the synergistic effect of butyl rubber and polyisobutylene, the preferred mass ratio of butyl rubber to polyisobutylene is 1 to 4:1; the preferred degree of unsaturation of butyl rubber is 0.1 to 2.1%; the preferred number average molecular weight of butyl rubber is 5,000 to 500,000; and the preferred number average molecular weight of polyisobutylene is 1,000 to 200,000.

[0033] In one embodiment of this application, the particle size of the desiccant is 0.1 to 10 μm. Preferably, the desiccant is selected from any one or more of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, anhydrous calcium chloride, and anhydrous magnesium sulfate. Preferably, the desiccant is a combination of 3A molecular sieve, 4A molecular sieve, and 5A molecular sieve. Further, the mass ratio of 3A molecular sieve, 4A molecular sieve, and 5A molecular sieve is 1:1 to 10:0.5 to 1. Preferably, the particle size of the filler is 0.01 to 0.5 μm. Preferably, the filler is selected from any one or more of fumed silica, carbon black, silica, talc, mica, magnesium silicate, alumina, and calcium carbonate.

[0034] The preferred desiccants described above facilitate synergy with butyl rubber and polyisobutylene. In particular, the mass ratio of 3A, 4A, and 5A molecular sieves results in a desiccant with richer porosity, allowing it to quickly absorb moisture from the photovoltaic module and mitigate its erosion of the pores. These fillers also contribute to further enhancing the strength of the sealant.

[0035] Preferably, the sealant further comprises 1 to 15 parts of a composite resin, preferably selected from copolymers of propylene, butene, pentene, hexene, octene, norbornene, and styrene with ethylene, or polyethylene and polypropylene, preferably grafted with silane and / or maleic anhydride; preferably, the sealant further comprises 0.01 to 5 parts of an additive, preferably selected from antioxidants and / or light stabilizers, preferably selected from aromatic amine antioxidants, hindered phenolic antioxidants, salicylate antioxidants, benzophenone antioxidants, and triazine antioxidants, preferably a hindered amine light stabilizer.

[0036] The addition of composite resins helps to further adjust the viscosity of the sealant, making it easier to fill openings. Preferred additives help to improve the sealant's resistance to aging, thereby extending its lifespan. Specific composite resins include Mitsui 0540, Dow 8660, 0540, LG3588, and Evonik 708. Specific additives include 2-hydroxy-4-methoxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-[4-[2-hydroxy-3-dodecyloxypropyl]oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2'-methylenebis-(4-methyl-6-tert-butylphenol), and 4,4'-diisopropylphenyldiphenylamine.

[0037] Preferably, the water vapor permeability of the above-mentioned sealant is ≤10%.-1 g / m 2 / 24h; the bonding strength between the sealant and the back glass of the photovoltaic module, and between the sealant and the junction box of the photovoltaic module, are each ≥10N / 10mm independently; the complex viscosity of the sealant at 150℃ is between 1000 and 100000 Pa·s, and the creep size of the sealant at 150℃ is ≤1mm, which helps to further improve the sealing effect of the sealant on the opening and the water vapor barrier properties.

[0038] In another typical embodiment of this application, a method for encapsulating a photovoltaic module is provided. The method includes: stacking a front glass layer, a front encapsulating film, a cell, a rear encapsulating film, and a rear glass layer to obtain a stacked module. The rear glass layer has an opening, and the cell cells of the cell collect current through a busbar, which passes through the opening to be electrically connected to a junction box. The remaining portion of the opening is filled with an encapsulating material. The junction box is then attached to the opening. The stacked module is then laminated to obtain a photovoltaic module. The encapsulating material includes the aforementioned sealant.

[0039] The above-mentioned encapsulation method can fill the opening with the encapsulation material including the above-mentioned sealant, thereby effectively preventing the opening from being corroded by moisture from the external environment. It can also solve the problem of insufficient insulation and appearance defects caused by air bubbles at the opening during lamination, thus helping to improve the long-term reliability of photovoltaic modules and the yield of lamination process, and finally obtaining photovoltaic modules with excellent comprehensive performance.

[0040] Preferably, the volume ratio of the filling material to the remaining portion of the opening is 1 to 1.5:1, which helps to fill the opening more fully. Preferably, the encapsulation material also includes a silicone sealant, and the filling process preferably includes: coating a layer of silicone sealant on the inner wall of the opening to form a coated opening; injecting sealant into the coated opening, preferably the volume ratio of silicone sealant to other sealants is 1 to 50:1, more preferably 5 to 50:1; further preferably, the silicone sealant is a de-alcoholized silicone and / or a deoxime-type silicone.

[0041] The above-described filling process ensures excellent moisture barrier properties at the opening through the sealant, while the silicone sealant improves the adhesion between the encapsulation material inside the opening and the back glass and junction box. By controlling the volume ratio of silicone sealant to sealant within the aforementioned range, it is beneficial to further balance the moisture barrier properties and adhesion of the encapsulation material inside the opening.

[0042] In another typical embodiment of this application, a photovoltaic module is provided, which is prepared by the aforementioned encapsulation method.

[0043] The photovoltaic modules prepared by the aforementioned encapsulation method have excellent reliability.

[0044] In another typical embodiment of this application, an electronic component is provided, which is any one of a liquid crystal panel, an electroluminescent device, a plasma display device, and a touch screen. The power supply structure of the electronic component is a photovoltaic module, which is the aforementioned photovoltaic module.

[0045] The electronic components of the photovoltaic modules mentioned above have excellent lifespan and appearance.

[0046] The beneficial effects of this application will be explained below with reference to specific embodiments and comparative examples.

[0047] Example 1

[0048] First, add 30 parts of butyl rubber (number average molecular weight 10,000) and 20 parts of polyisobutylene (number average molecular weight 10,000) to a kneader, heat to 120°C, and mix for 10 minutes; add a desiccant and mix for another 10 minutes; then, evenly spray 0.02 parts of isopropyl tris(dodecylbenzenesulfonyl) titanate coupling agent onto the surface of the material in the kneader and mix for 8 minutes; finally, heat to 160°C and mix for 10 minutes. One part of silica filler (average particle size of 0.5 μm), 0.01 parts of p-phenylenediamine antioxidant, and 5 parts of silane-grafted polypropylene composite resin were added and mixed at a constant temperature for 30 minutes. Then, the mixture was further mixed at a vacuum of 0.08 MPa for 40 minutes to obtain a sealant. The total amount of desiccant (3A molecular sieve, 4A molecular sieve, and 5A molecular sieve in a mass ratio of 1:5:0.8) was 10 parts, with an average particle size of 5 μm.

[0049] Example 2

[0050] The difference from Example 1 is that the butyl rubber is 40 parts, the polyisobutylene is 30 parts, the desiccant is 20 parts, the silica filler is 3 parts, and the isopropyltris(dodecylbenzenesulfonyl)titanate coupling agent is 0.1 parts, and the final sealant is obtained.

[0051] Example 3

[0052] The difference from Example 1 is that the butyl rubber is 35 parts, the polyisobutylene is 10 parts, the desiccant is 35 parts, the silica filler is 5 parts, and the isopropyltris(dodecylbenzenesulfonyl)titanate coupling agent is 0.2 parts, and the final sealant is obtained.

[0053] Example 4

[0054] The difference from Example 1 is that the butyl rubber is 20 parts, the polyisobutylene is 40 parts, the desiccant is 5 parts, the silica filler is 6 parts, and the isopropyltris(dodecylbenzenesulfonyl)titanate coupling agent is 0.01 parts, and the final sealant is obtained.

[0055] Example 5

[0056] The difference from Example 1 is that the mass ratio of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve is 1:1:0.5, and the final sealant is obtained.

[0057] Example 6

[0058] The difference from Example 1 is that the mass ratio of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve is 1:10:1, and the final sealant is obtained.

[0059] Example 7

[0060] The difference from Example 1 is that the mass ratio of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve is 1:0.5:2, and the final sealant is obtained.

[0061] Example 8

[0062] The difference from Example 1 is that the desiccant is 3A molecular sieve, and the final product is a sealant.

[0063] Example 9

[0064] The difference from Example 1 is that R is 3 and R' is 18 in the titanate coupling agent, and isopropyl triisostearate titanate isopropyl triisostearate is used to obtain the sealant.

[0065] Example 10

[0066] The difference from Example 1 is that butyl rubber is 25 parts and polyisobutylene is 25 parts, resulting in a sealant.

[0067] Example 11

[0068] The difference from Example 1 is that 40 parts of butyl rubber and 10 parts of polyisobutylene are used to obtain the sealant.

[0069] Example 12

[0070] The difference from Example 1 is that butyl rubber is 20 parts and polyisobutylene is 30 parts, resulting in a sealant.

[0071] Example 13

[0072] The difference from Example 1 is that the number average molecular weight of butyl rubber is 500,000 and the number average molecular weight of polyisobutylene is 200,000, resulting in a sealant.

[0073] Example 14

[0074] The difference from Example 1 is that the average particle size of the 3A molecular sieve, 4A molecular sieve and 5A molecular sieve is 10μm, and the final sealant is obtained.

[0075] Example 15

[0076] The difference from Example 1 is that the average particle size of the 3A molecular sieve, 4A molecular sieve and 5A molecular sieve is 12μm, and the final sealant is obtained.

[0077] Example 16

[0078] The difference from Example 1 is that the filler is carbon black alumina with an average particle size of 0.05 μm, and the final sealant is obtained.

[0079] Example 17

[0080] The difference from Example 1 is that the composite resin is norbornene, and the final product is a sealant.

[0081] Photovoltaic module examples 1 to 17

[0082] A stacked assembly is obtained by laminating a front glass layer, a front encapsulating film (F406PS), a battery cell, a rear encapsulating film (F806PS), and a rear glass layer. The rear glass layer has an opening. The battery cells of the battery cell collect current through a busbar, which passes through the opening to connect electrically to the junction box. The remaining portion of the opening is filled with an encapsulating material. The junction box is then attached to the opening. A layer of FS527 type de-alcoholized silicone (Hangzhou Foster Applied Materials Co., Ltd.) is coated on the inner wall of the opening to form a coated opening. A sealant prepared in Examples 1 to 17 is injected into the coated opening. The encapsulating material includes FS527 type de-alcoholized silicone and sealant. The total volume ratio of the encapsulating material to the remaining portion of the opening is 1.2:1, and the volume ratio of FS527 type de-alcoholized silicone to sealant is 10:1.

[0083] The front and back encapsulation films mentioned above can also be replaced with EVA and / or POE.

[0084] Photovoltaic module comparison example 1

[0085] The difference from the photovoltaic module embodiment 1 is that the opening is not sealed to obtain the photovoltaic module.

[0086] Photovoltaic module comparison example 2

[0087] The difference from Example 1 of the photovoltaic module is that FS527 de-alcoholized silicone is used as the encapsulation material to seal the openings to obtain the photovoltaic module.

[0088] The performance of the photovoltaic modules in Examples 1 to 17, Comparative Examples 1 and 2 was tested, and the results are shown in Table 1.

[0089] 1. Water vapor transmission rate

[0090] The test method is based on the standard ASTM F1249, "Test method for determining water vapor permeability of plastic films and sheets using modulated infrared sensors".

[0091] Testing instrument: Water vapor transmission rate tester.

[0092] Test conditions: 38℃, 90%RH.

[0093] 2. Volume resistivity

[0094] The test method refers to the standard GB / T 31034 "Insulating Backsheet for Crystalline Silicon Solar Cell Modules".

[0095] Sample size: 100mm × 100mm.

[0096] Test conditions: Test voltage 1000V.

[0097] 3. Yellowing Index

[0098] The test method is in accordance with standard GB / T 2409 "Test Method for Yellow Index of Plastics".

[0099] Sample size: 100mm × 100mm.

[0100] Test conditions: +25℃, 50%RH.

[0101] 4. Peel strength with glass and junction box

[0102] The test method refers to the standard GB / T2790 "Adhesives 180° Peel Strength Test Method for Flexible Materials vs. Rigid Materials".

[0103] Sample size: 300mm×300mm, photovoltaic tempered glass is used for the glass, and polyphenylene oxide board is used for the junction box.

[0104] Tensioning speed: 100mm / min.

[0105] 5. Constant resistance to damp heat aging

[0106] The test method follows the standard GB / T 29848 "Ethylene-vinyl acetate copolymer (EVA) film for photovoltaic module encapsulation". Test conditions: +85℃, relative humidity 85%.

[0107] 6. UV aging performance

[0108] The test method follows the standard GB / T 29848 "Ethylene-vinyl acetate copolymer (EVA) film for photovoltaic module encapsulation". Test conditions: 60±5℃.

[0109] 7. Maximum power

[0110] The testing method is based on standard IEC61215 "Ground-mounted crystalline silicon photovoltaic modules - Design qualification and type approval".

[0111] Sample size: Bifacial solar cells, 72-cell module.

[0112] Test conditions: AM 1.5, irradiance 1000W / m 2 +25℃, 50%RH.

[0113] 8. Creep performance

[0114] like Figure 5 The schematic diagram shows the test method as follows: A sealing strip with dimensions of 300mm×20mm×0.75mm is placed between two pieces of glass with dimensions of 300mm×300mm×2.5mm (length×width×thickness). After lamination at 145℃ for 18 minutes, it is vertically suspended in a 150℃ oven, and an additional load of 1KG is bonded to the lower glass. After standing for 48 hours, the downward displacement distance of the lower edge of the sealing strip is measured, which is the creep dimension.

[0115] Table 1

[0116]

[0117]

[0118] Table 2

[0119]

[0120] Table 3

[0121]

[0122] As shown in Tables 1 to 3, the photovoltaic modules corresponding to Examples 1 to 17 all exhibit high water vapor barrier properties, insulation properties, and aging resistance. Compared with Comparative Examples 1 and 2, these modules demonstrate superior performance in terms of power output, DH power attenuation, module appearance, and EL pattern. Power stability is significantly improved, and the bubble problem in the appearance is also resolved.

[0123] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0124] The butyl rubber and polyisobutylene in this application exhibit microcrystals due to the dense arrangement of side methyl groups in their molecular chains, which restricts the thermal motion of the molecular chains and reduces their flexibility. These structural features give butyl rubber and polyisobutylene excellent weather resistance, heat resistance, and alkali resistance, as well as low air permeability and good air tightness; their air permeability is an order of magnitude lower than that of natural rubber. The desiccant is an adsorbent used to adjust the moisture barrier properties of the sealant, and the filler is a colorimetric or strength-reinforcing filler, providing a certain degree of sealant reinforcement. The titanate coupling agent interacts with the desiccant, achieving coupling through chemical adsorption or chemical reaction between the RO groups and trace amounts of hydroxyl groups or protons on the surface of the desiccant. The long-chain alkane segments in OX-R'-Y assist in the winding and fixing of desiccants and fillers. X helps enhance the compatibility of inorganic fillers with polymer resins. The polar groups in Y undergo micro-crosslinking reactions with the unsaturated bonds in the polymer resin, resulting in a uniform and stable crosslinked structure between the polymer resin and inorganic fillers. This promotes the uniform mixing of inorganic particles (desiccants, fillers) and organic materials (butyl rubber and polyisobutylene), thus mitigating the cold flow of butyl rubber and polyisobutylene and reducing the degradation or migration of these materials, which leads to a decrease in the moisture barrier properties of the sealant. This further improves the moisture barrier properties of the sealant. When used to seal openings in photovoltaic modules, this sealant effectively prevents moisture erosion at the openings and solves the problems of insufficient insulation and appearance defects caused by air bubbles at the openings during lamination. This improves the long-term reliability of photovoltaic modules and the yield rate of the lamination process, resulting in photovoltaic modules with excellent overall performance. Furthermore, this sealant can be applied using equipment, enabling automated production lines.

[0125] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sealant, characterized in that, The sealant comprises, by weight, the following components: 30-40 parts of butyl rubber: 10-30 parts of polyisobutylene; 10-35 parts of desiccant; 1-15 parts of filler; and 0.02~0.2 parts of titanate coupling agent, The general structural formula of the titanate coupling agent is (RO). m -Ti(OX-R'-Y) n m is any integer from 1 to 4, n is an integer, and n = 6 - m, R is a series of integers from C1 to C2. 10 The alkane group, X is selected from any element C, N, P, S, R' is a C8 or larger alkane group, and Y is selected from any element hydroxyl, amino, or double bond; The mass ratio of butyl rubber to polyisobutylene is 1~4:1; the degree of unsaturation of the butyl rubber is 0.1~2.1%; The desiccant is a combination of 3A molecular sieve, 4A molecular sieve and 5A molecular sieve; The water vapor permeability of the sealant is ≤10%. -1 g / m 2 / 24h; the bonding strength between the sealant and the back glass of the photovoltaic module, and between the sealant and the junction box of the photovoltaic module, are each ≥10N / 10mm independently.

2. The sealant according to claim 1, characterized in that, The R is a C1~C4 alkane group, and the R' is a C8~C4 alkane group. 20 alkane group.

3. The sealant according to claim 1 or 2, characterized in that, The number average molecular weight of the butyl rubber is 5,000 to 500,000; the number average molecular weight of the polyisobutylene is 1,000 to 200,000.

4. The sealant according to claim 1 or 2, characterized in that, The particle size of the desiccant is 0.1~10μm.

5. The sealant according to claim 1 or 2, characterized in that, The mass ratio of the 3A molecular sieve, the 4A molecular sieve, and the 5A molecular sieve is 1:1~10:0.5~1.

6. The sealant according to claim 1 or 2, characterized in that, The filler has a particle size of 0.01~0.5μm and is selected from any one or more of fumed silica, carbon black, silica, talc, mica, magnesium silicate, alumina, and calcium carbonate.

7. The sealant according to claim 1 or 2, characterized in that, The sealant also includes 1 to 15 parts of a composite resin, wherein the composite resin is selected from any one or more copolymers of propylene, butene, pentene, hexene, octene, norbornene, and styrene with ethylene, or any one or more of polyethylene and polypropylene.

8. The sealant according to claim 7, characterized in that, The composite resin is subjected to silane and / or maleic anhydride grafting treatment.

9. The sealant according to claim 1 or 2, characterized in that, The sealant further includes 0.01 to 5 parts of additives, which are selected from antioxidants and / or light stabilizers. The antioxidants are selected from any one or more of aromatic amine antioxidants, hindered phenolic antioxidants, salicylate antioxidants, benzophenone antioxidants, and triazine antioxidants. The light stabilizer is a hindered amine light stabilizer.

10. The sealant according to claim 1 or 2, characterized in that, The sealant has a complex viscosity of 1000~100000 Pa·s at 150°C and a creep dimension of ≤1 mm at 150°C.

11. A method for encapsulating a photovoltaic module, characterized in that, The encapsulation method includes: A stacked assembly is obtained by layering and laying a front glass layer, a front encapsulating film, a battery cell, a rear encapsulating film, and a rear glass layer. The rear glass layer has an opening. The battery cells of the battery cell collect current through a busbar. The busbar passes through the opening to be electrically connected to the junction box. The remaining portion of the opening is filled with an encapsulating material; Fit the junction box to the opening; The laminated assembly is laminated to obtain the photovoltaic module, wherein the encapsulation material comprises the sealant according to any one of claims 1 to 10.

12. The packaging method according to claim 11, characterized in that, The ratio of the filling volume of the encapsulation material to the volume of the remaining portion of the opening is 1~1.5:

1.

13. The packaging method according to claim 11, characterized in that, The encapsulation material also includes silicone sealant, and the filling process includes: A layer of the silicone sealant is coated on the inner wall of the opening to form a coated opening; The sealant is injected into the opening after coating. The volume ratio of the silicone sealant to the sealant is 1~50:

1.

14. The packaging method according to claim 13, characterized in that, The volume ratio of the silicone sealant to the sealant is 5~50:

1.

15. The packaging method according to claim 13, characterized in that, The silicone sealant is a de-alcoholized silicone and / or a deoxime-type silicone.

16. A photovoltaic module, characterized in that, The photovoltaic module is prepared by the encapsulation method described in any one of claims 11 to 15.

17. An electronic component, wherein the electronic component is any one of a liquid crystal panel, an electroluminescent device, a plasma display device, and a touch screen, and the power supply structure of the electronic component is a photovoltaic module, characterized in that, The photovoltaic module is the photovoltaic module of claim 16.

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