High-melting-point packaging adhesive film for main-grid-free assembly and preparation method of high-melting-point packaging adhesive film
By using high melting point thermoplastic particles in the main gate-free packaging film and adopting high-temperature and low-flowability processes, the hidden cracking and dummy welding problems caused by uneven pre-crosslinking during the lamination process are solved, and a more stable welding effect and a longer life of photovoltaic modules are achieved.
Patent Information
- Application Number
- CN202510184451.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-19
- Publication Date
- 2025-05-13
AI Technical Summary
The existing main gate-free packaging films are prone to problems such as uneven distribution of pre-crosslinking, local dummy welding, wire offset, sheet bias or excessive pre-crosslinking during the lamination process.
High melting point thermoplastic particles are used as part of the packaging film, with a ratio of 80%-92% low melting point particles, 3%-10% high melting point particles, 2%-6% thermal initiator, 1%-3% crosslinking additive, 0.5%-2% coupling agent, and 0.5%-2% antioxidant. No pre-crosslinking is performed, and the welding quality is ensured by low fluidity at high temperature.
It effectively avoids the problem of hidden cracking caused by excessive pre-crosslinking, and maintains the relative displacement of the welding wire and the battery during lamination, reduces the occurrence of dummy welding patches and extends the service life of photovoltaic modules.
Smart Images
Figure CN119979052A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of photovoltaic components, in particular to a high melting point packaging adhesive film for a main grid-free component and a preparation method thereof. Background Art
[0002] Busbarless encapsulation film is a photovoltaic encapsulation material designed specifically for busbarless technology. It reduces production costs by optimizing the connection between the cell and the welding ribbon and reducing the amount of silver paste. The encapsulation film can isolate the cell from the external environment, preventing it from being corroded by water vapor, oxygen, dust, ultraviolet rays and other factors, avoiding corrosion and aging of the cell, thereby extending the service life of the photovoltaic module.
[0003] In recent years, the application of busbar-free encapsulation film in the photovoltaic industry has gradually increased. Its special structure requires the encapsulation film to have low fluidity to ensure the ideal alloying effect during the lamination process of the solder ribbon and the battery cell to avoid the occurrence of false joints.
[0004] At present, most of the busbar-free encapsulation films are pre-crosslinked to a pre-crosslinking degree of 35%-50%, thereby reducing the fluidity of the film during lamination and ensuring alloying of the welding wire and the battery cell. This type of film is prone to uneven distribution of pre-crosslinking degree, local cold welding after lamination; or large differences in fluidity between the local and overall film, resulting in welding wire deviation, sheeting, and even black sheets; or excessive pre-crosslinking, resulting in hidden cracks in the battery cell after lamination. Summary of the invention
[0005] In order to solve the problems of the prior art, the present invention provides a high-melting-point encapsulation film for a main-grid-free component and a preparation method thereof. High-melting-point thermoplastic particles are added to the encapsulation film formula, which has a higher melting point and does not require pre-crosslinking. It has low fluidity at high temperatures and will not cause hidden cracks in the battery cell due to an excessively high degree of pre-crosslinking.
[0006] The present invention provides a high-melting-point packaging film for a main-grid-free component, comprising the following components in percentage by mass: low-melting-point particles: 80%-92%, high-melting-point particles: 3%-10%, thermal initiator: 2%-6%, cross-linking aid: 1%-3%, coupling agent: 0.5%-2%, antioxidant: 0.5%-2%. The packaging film obtained by coating the above components has a thickness of 100-300 microns.
[0007] As a further improvement, the low melting point particles are one or more of the following resins: EVA particles, POE particles, and PVB particles.
[0008] As a further improvement, the high melting point particles are one or more of the following resins: PE particles, PP particles, TPU particles, PMMA particles.
[0009] In a further improvement, the thermal initiator is one or more of the following: benzoyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide, and di-tert-amyl hydroperoxide.
[0010] As a further improvement, the cross-linking aid is one or more of the following: 2-phenoxyethyl acrylate, triallyl cyanurate, trimethylolpropane trimethacrylate.
[0011] In a further improvement, the coupling agent is one or more of the following: 2-hydroxyethyl methacrylate phosphate (HEMAP), KH570, KH560.
[0012] As a further improvement, the antioxidant is one or more of the following: hindered amine antioxidants and phosphite antioxidants.
[0013] The present invention also provides a method for preparing a high melting point encapsulation adhesive film for a busbar-free component, comprising the following steps: 1) Select the following raw material components in mass percentage, including low melting point particles: 80%-92%, high melting point particles: 3%-10%, thermal initiator: 2%-6%, cross-linking aid: 1%-3%, coupling agent: 0.5%-2%, antioxidant: 0.5%-2%; 2) Stir the above mixture evenly and coat it to obtain a packaging film; 3) Soften the finished film in a laminator chamber at 105℃-120℃. At this temperature, the low-temperature welding wire is welded to the battery cell; 4) At 140℃-150℃ in the second chamber of the laminator, the film is completely melted and undergoes a cross-linking reaction.
[0014] The beneficial effects of the present invention are: 1. Compared with the previous use of electron beam to pre-crosslink 0BB encapsulation film, high melting point particles are added, which has a higher melting point and low fluidity at high temperature, and avoids the relative displacement of the battery cell and the welding wire after lamination, which causes the appearance of black film.
[0015] 2. During lamination, the battery cells will not have hidden cracks due to an excessively high degree of pre-crosslinking, and no new cold soldering spots will be generated during 200 cycles of thermal cycle testing, thus reducing power attenuation. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0017] Figure 1 This is the EL image of the packaging film obtained in Example 1.
[0018] Figure 2 This is the EL image of the packaging film obtained in Example 2.
[0019] Figure 3 This is the EL image of the packaging film obtained in Example 3.
[0020] Figure 4 This is the EL image of the packaging film obtained in the comparative example. DETAILED DESCRIPTION
[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0022] The present invention provides a high-melting-point packaging film for a main-grid-free component, comprising the following components in percentage by mass: low-melting-point particles: 80%-92%, high-melting-point particles: 3%-10%, thermal initiator: 2%-6%, cross-linking aid: 1%-3%, coupling agent: 0.5%-2%, antioxidant: 0.5%-2%. The packaging film obtained by coating the above components has a thickness of 100-300 microns.
[0023] As a further improvement, the low melting point particles are one or more of the following resins: EVA particles, POE particles, and PVB particles.
[0024] As a further improvement, the high melting point particles are one or more of the following resins: PE particles, PP particles, TPU particles, PMMA particles.
[0025] In a further improvement, the thermal initiator is one or more of the following: benzoyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide, and di-tert-amyl hydroperoxide.
[0026] As a further improvement, the cross-linking aid is one or more of the following: 2-phenoxyethyl acrylate, triallyl cyanurate, trimethylolpropane trimethacrylate.
[0027] In a further improvement, the coupling agent is one or more of the following: 2-hydroxyethyl methacrylate phosphate (HEMAP), KH570, KH560.
[0028] As a further improvement, the antioxidant is one or more of the following: hindered amine antioxidants and phosphite antioxidants.
[0029] The present invention also provides a method for preparing a high melting point encapsulation adhesive film for a busbar-free component, comprising the following steps: 1) Select the following raw material components in mass percentage, including low melting point particles: 80%-92%, high melting point particles: 3%-10%, thermal initiator: 2%-6%, cross-linking aid: 1%-3%, coupling agent: 0.5%-2%, antioxidant: 0.5%-2%; 2) Stir the above mixture evenly and coat it to obtain a packaging film; 3) Soften the finished film in a laminator chamber at 105℃-120℃. At this temperature, the low-temperature welding wire is welded to the battery cell; 4) At 140℃-150℃ in the second chamber of the laminator, the film is completely melted and undergoes a cross-linking reaction.
[0030] According to the above preparation method, different components are used to obtain the following three embodiments: Example
[0031] 1. EVA particles: 90% 2. PE particles: 5% 3. Benzoyl peroxide: 2% 4. Triallyl cyanurate: 2% 5. 2-Hydroxyethyl methacrylate phosphate (HEMAP): 0.5% 6. Hindered amine antioxidant: 0.5% The above are mixed in proportion, stirred evenly, and coated to obtain the patented packaging film with a thickness of 200 microns. The EL picture is as follows Figure 1 shown. Example
[0032] 1. PVB particles: 85% 2. PP granules: 10% 3. Tert-butyl benzoyl peroxide: 2% 4. Trimethylolpropane trimethacrylate: 1% 5. KH570: 1% 6. Phosphite antioxidant: 1% The above are mixed in proportion, stirred evenly, and coated to obtain the patented packaging film with a thickness of 200 microns. The EL picture is as follows Figure 2 shown. Example
[0033] 1. POE particles: 87% 2. TPU particles: 5% 3. Methyl ethyl ketone oxide: 2.5% 4. 2-Phenoxyethyl acrylate: 3% 5. KH560: 1.5% 6. Hindered amine antioxidant: 1% The above are mixed in proportion, stirred evenly, and coated to obtain the patented packaging film with a thickness of 200 microns. The EL picture is as follows Figure 3 shown.
[0034] For comparison, the existing encapsulation film formula was used and pre-crosslinked to obtain a comparative example. The EL graph is as follows: Figure 4 As shown, three embodiments and comparative embodiments were tested to obtain the following data: TC200 Power Attenuation DH1000 Power Attenuation 200℃*4h high temperature resistance test Embodiment 1 -0.77% -1.56% OK Embodiment 2 -0.84% -1.27% OK Embodiment 3 -0.96% -1.79% OK Comparative Example -1.13% -1.96% NG (bubbles) Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred embodiment of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field is within the technical scope disclosed by the present invention. For ordinary technicians in the technical field, changes or replacements that can be easily thought of should be covered within the protection scope of the present invention without departing from the principle of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A high melting point encapsulation film for a busbar-free component, characterized in that: The invention comprises the following components in percentage by weight: low melting point particles: 80%-92%, high melting point particles: 3%-10%, thermal initiator: 2%-6%, cross-linking aid: 1%-3%, coupling agent: 0.5%-2%, antioxidant: 0.5%-2%. The thickness of the packaging film obtained by coating the above components is 100-300 microns.
2. The high melting point encapsulation film for busbar-free components according to claim 1, characterized in that: The low melting point particles are one or more of the following resins: EVA particles, POE particles, and PVB particles.
3. The high melting point encapsulation film for busbar-free components according to claim 1, characterized in that: The high melting point particles are one or more of the following resins: PE particles, PP particles, TPU particles, PMMA particles.
4. The high melting point encapsulation film for busbar-free components according to claim 1, characterized in that: The thermal initiator is one or more of the following: benzoyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide, and di-tert-amyl hydroperoxide.
5. The high melting point encapsulation film for busbar-free components according to claim 1, characterized in that: The cross-linking aid is one or more of the following: 2-phenoxyethyl acrylate, triallyl cyanurate, trimethylolpropane trimethacrylate.
6. The high melting point encapsulation film for busbar-free components according to claim 1, characterized in that: The coupling agent is one or more of the following: 2-hydroxyethyl methacrylate phosphate (HEMAP), KH570, KH560.
7. The high melting point encapsulation film for busbar-free components according to claim 1, characterized in that: The antioxidant is one or more of the following: hindered amine antioxidants and phosphite antioxidants.
8. A method for preparing a high melting point encapsulation adhesive film for a busbar-free assembly according to any one of claims 1 to 7, characterized in that The following steps are involved: 1) Select the following raw material components in mass percentage, including low melting point particles: 80%-92%, high melting point particles: 3%-10%, thermal initiator: 2%-6%, cross-linking aid: 1%-3%, coupling agent: 0.5%-2%, antioxidant: 0.5%-2%; 2) Stir the above mixture evenly and coat it to obtain a packaging film; 3) Soften the finished film in a laminator chamber at 105℃-120℃. At this temperature, the low-temperature welding wire is welded to the battery cell; 4) At 140℃-150℃ in the second chamber of the laminator, the film is completely melted and undergoes a cross-linking reaction.