Pouring sealant and preparation method thereof
By preparing a potting compound by mixing components A and B, the problem of high water vapor permeability of traditional silicone potting compounds is solved, achieving lower water vapor permeability and better resistance to damp heat, thus meeting the encapsulation requirements of N-type solar cells and perovskite modules.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-11
- Publication Date
- 2026-04-03
AI Technical Summary
Traditional silicone potting compounds have high water vapor permeability and cannot effectively prevent water vapor penetration, thus failing to meet the encapsulation requirements of N-type solar cells and perovskite modules.
A potting compound with lower water vapor permeability was prepared by using components A and B. Component A includes a polyol, a first filler, a first plasticizer, an antioxidant, and a catalyst. Component B includes an isocyanate-terminated polyol, an alkoxy-terminated polybutadiene, a second filler, a second plasticizer, a coupling agent, and a dehydrating agent.
It achieves lower water vapor permeability and better resistance to damp heat, and has high strength retention after DH aging, meeting the encapsulation requirements of N-type solar cells and perovskite modules.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of polyurethane adhesive technology, specifically relating to a potting compound and its preparation method. Background Technology
[0002] With the development of photovoltaic technology, N-type solar cells have completely replaced P-type solar cells. While N-type solar cells significantly improve photoelectric conversion efficiency, they are also sensitive to moisture and ultraviolet light. Perovskite modules represent the next generation of photovoltaic module technology, further improving photoelectric conversion efficiency at a lower cost. However, perovskite modules also exhibit sensitivity to high temperatures, moisture, and ultraviolet light. Both N-type and perovskite modules place higher demands on module encapsulation. The connection point between the busbar leads and the photovoltaic junction box is a weak point in the encapsulation. Traditional junction boxes use silicone potting compound for sealing. Due to its structural characteristics, silicone has numerous internal pores and high moisture permeability; at 38℃, a 1mm thickness has a moisture permeability of 40-50g / m³. 2 •d, which cannot effectively prevent water vapor penetration, therefore potting compounds with lower water vapor permeability are needed to meet the encapsulation requirements of N-type modules and perovskite modules. Summary of the Invention
[0003] To address the shortcomings of existing technologies, this invention provides a potting compound and its preparation method, wherein the potting compound has a lower water vapor permeability.
[0004] To achieve the above objectives, the present invention adopts the following technical solution: On one hand, the present invention provides a potting compound comprising component A and component B. Component A comprises a polyol, a first filler, a first plasticizer, an antioxidant, and a catalyst; component B comprises an isocyanate-terminated polyol, an alkoxy-terminated polybutadiene, a second filler, a second plasticizer, a coupling agent, and a dehydrating agent.
[0005] Preferably, in component A, the polyol is 40-50 parts by weight, the first filler is 30-40 parts by weight, the first plasticizer is 10-20 parts by weight, the antioxidant is 1-3 parts by weight, and the catalyst is 0.1-1 parts by weight. In component B, the weight percentages of isocyanate-terminated polyol are 40-50 parts, the weight percentages of alkoxy-terminated polybutadiene are 10-20 parts, the weight percentages of the second filler are 30-40 parts, the weight percentages of the second plasticizer are 10-20 parts, the weight percentages of the coupling agent are 1-10 parts, and the weight percentages of the dehydrating agent are 0.1-1 parts.
[0006] Preferably, the polyol comprises at least one of hydroxyl-terminated polybutadiene and hydroxyl-terminated hydrogenated polybutadiene; and / or, The molecular weight of the polyol is 500-2900.
[0007] Preferably, both the first and second fillers comprise at least one of heavy calcium carbonate, aluminum hydroxide, alumina, and silica powder; and / or, The particle size of both the first and second fillers is 5-20µm.
[0008] Preferably, both the first plasticizer and the second plasticizer comprise at least one of phthalate, di(2-ethylhexyl) adipic acid, di(2-ethylhexyl) sebacate, di(2-ethylhexyl) azelaate, diol benzoate, and phosphate sulfonate.
[0009] Preferably, the anti-aging agent includes an ultraviolet light absorber and an antioxidant. The ultraviolet light absorber includes at least one of benzophenone, triazole, or triazine, and the antioxidant includes at least one of 1010, 168, and 626.
[0010] Preferably, the isocyanate-terminated polyol contains at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate. The isocyanate-terminated polyol includes hydroxy-terminated polybutadiene, hydroxy-terminated hydrogenated polybutadiene, or hydroxy-terminated polyisobutylene. The isocyanate-terminated polyol has a molar ratio of isocyanate to hydroxyl groups of the polyol of (2-2.5):1.
[0011] Preferably, the alkoxy-terminated polybutadiene comprises propyltrimethoxysilane isocyanate, propyltriethoxysilane, or propylmethyldimethoxysilane isocyanate.
[0012] Preferably, the coupling agent comprises at least one selected from propyltrimethoxysilane isocyanate, propyltriethoxysilane isocyanate, n-butylaminopropyltrimethoxysilane, bis[(triethoxy)propyl]amine, 3-(1,3-dimethylbutene)aminopropyltriethoxysilane, N,N-diethyl-3-aminopropyltrimethoxysilane, and mercaptomasked silane; and / or, The dehydrating agent includes molecular sieves or p-toluenesulfonyl isocyanate; and / or... The catalyst includes stannous octoate or dibutyltin dilaurate.
[0013] On the other hand, the present invention provides a method for preparing the potting compound, comprising the following steps: S1. Mix the polyol, the first filler, the first plasticizer, the antioxidant, and the catalyst to obtain component A; S2. Mix isocyanate-terminated polyol, alkoxy-terminated polybutadiene, second filler, second plasticizer, coupling agent and dehydrating agent to obtain component B; S3. Mix component A and component B to obtain potting compound.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The potting compound prepared by the present invention through components A and B has strong hydrophobicity, resulting in lower water vapor permeability and better resistance to damp heat. It also has a higher strength retention rate after DH aging. Detailed Implementation
[0015] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention.
[0016] In some embodiments, the method for preparing potting compound specifically includes the following steps: Polyol, first filler, first plasticizer, and antioxidant are added to a reaction vessel and stirred evenly. The mixture is heated to 90-130℃ under vacuum and dehydrated for 2 hours. After cooling to room temperature, catalyst is added and stirred evenly to obtain component A. Polyols are added to a reaction vessel and heated to 90-130℃ under vacuum for 2 hours to remove water. After cooling to room temperature, diisocyanate is added, with the molar ratio of diisocyanate to polyol controlled at (2-2.5):1. The reaction is carried out at 70-100℃ for 1-4 hours, and then cooled to room temperature to obtain isocyanate-terminated polyols. Alkoxy-terminated polybutadiene, a second filler, a second plasticizer, and a dehydrating agent are added to the isocyanate-terminated polyols. After vacuum stirring for 1-2 hours, a coupling agent is added, and the mixture is stirred until homogeneous to obtain component B.
[0017] The A and B components are mixed in a 1:1 ratio to obtain the potting compound.
[0018] Example 1 Component A consists of 49 parts by weight of hydroxyl-terminated polybutadiene with a molecular weight (Mn) of 1800; 35 parts by weight of silica powder with a median particle size of 10 µm; 15 parts by weight of di(undecyl) phthalate; 0.5 parts by weight of UV absorber UV234; 0.5 parts by weight of antioxidant 1010; and 0.2 parts by weight of dibutyltin dilaurate. These components were mixed according to the method described above for preparing Component A, and their viscosity was tested.
[0019] Component B: 100 parts by weight of hydroxyl-terminated polybutadiene, Mn1800; 26.7 parts by weight of toluene diisocyanate, with an isocyanate to hydroxyl molar ratio of 2.3:1. Isocyanate-terminated polybutadiene was synthesized according to the termination reaction conditions. After cooling to room temperature, 40 parts by weight of isocyanate-terminated polybutadiene, 10 parts by weight of alkoxy-terminated polybutadiene, 10 parts by weight of di(undecyl) phthalate, 35 parts by weight of silica powder with a median particle size of 10 µm, 4 parts by weight of bis[(triethoxy)propyl]amine, and 0.5 parts by weight of p-toluenesulfonyl isocyanate were mixed according to the method described above for preparing Component B, and their viscosity was tested.
[0020] After the A and B components were mixed in a 1:1 ratio, samples were prepared and tested sequentially for water vapor transmission rate, tensile strength, elongation at break, and appearance of the junction box after DH1000h.
[0021] Example 2 Component A: 49 parts by weight of hydroxyl-terminated polybutadiene, molecular weight Mn 2900; 35 parts by weight of silica powder, median particle size 10µm; 15 parts by weight of di(undecyl) phthalate; 0.5 parts by weight of UV absorber UV234; 0.5 parts by weight of antioxidant 1010; and 0.2 parts by weight of dibutyltin dilaurate. These components were mixed according to the method described above for preparing Component A, and their viscosity was tested.
[0022] Component B: 100 parts by weight of hydroxyl-terminated polybutadiene, Mn2900; 17.1 parts by weight of toluene diisocyanate, with an isocyanate to hydroxyl molar ratio of 2.3:1. Isocyanate-terminated polybutadiene was synthesized according to the end-capping reaction conditions. After cooling to room temperature, 40 parts by weight of isocyanate-terminated polybutadiene, 10 parts by weight of alkoxy-terminated polybutadiene, 10 parts by weight of di(undecyl) phthalate, 35 parts by weight of silica powder with a median particle size of 10 µm, 4 parts by weight of bis[(triethoxy)propyl]amine, and 0.5 parts by weight of p-toluenesulfonyl isocyanate were mixed according to the method described above for preparing Component B, and their viscosity was tested.
[0023] After the A and B components were mixed in a 1:1 ratio, samples were prepared and tested sequentially for water vapor transmission rate, tensile strength, elongation at break, and appearance of the junction box after DH1000h.
[0024] Example 3 Component A consists of 41 parts by weight of hydroxyl-terminated polybutadiene with a molecular weight (Mn) of 1800; 40 parts by weight of silica powder with a median particle size of 10 µm; 18 parts by weight of di(undecyl) phthalate; 0.5 parts by weight of UV absorber UV234; 0.5 parts by weight of antioxidant 1010; and 0.2 parts by weight of dibutyltin dilaurate. These components are mixed according to the method described above for preparing Component A, and their viscosity is tested.
[0025] Component B: 100 parts by weight of hydroxyl-terminated polybutadiene, Mn1800; 29 parts by weight of toluene diisocyanate, with an isocyanate to hydroxyl molar ratio of 2.5:1. Isocyanate-terminated polybutadiene was synthesized according to the termination reaction conditions. After cooling to room temperature, 35 parts by weight of isocyanate-terminated polybutadiene, 10 parts by weight of alkoxy-terminated polybutadiene, 10 parts by weight of di(undecyl) phthalate, 40 parts by weight of silica powder with a median particle size of 10 µm, 4 parts by weight of bis[(triethoxy)propyl]amine, and 0.5 parts by weight of p-toluenesulfonyl isocyanate were mixed according to the method described above for preparing Component B, and their viscosity was tested.
[0026] After the A and B components were mixed in a 1:1 ratio, samples were prepared and tested sequentially for water vapor transmission rate, tensile strength, elongation at break, and appearance of the junction box after DH1000h.
[0027] Comparative Example 1 Component A consists of 49 parts by weight of hydroxyl-terminated polybutadiene with a molecular weight (Mn) of 1800; 35 parts by weight of silica powder with a median particle size of 10 µm; 15 parts by weight of di(undecyl) phthalate; 0.5 parts by weight of UV absorber UV234; 0.5 parts by weight of antioxidant 1010; and 0.2 parts by weight of dibutyltin dilaurate. These components were mixed according to the method described above for preparing Component A, and their viscosity was tested.
[0028] Component B: 100 parts by weight of hydroxyl-terminated polybutadiene, Mn1800; 26.7 parts by weight of toluene diisocyanate, with an isocyanate to hydroxyl molar ratio of 2.3:1. Isocyanate-terminated polybutadiene was synthesized according to the end-capping reaction conditions. After cooling to room temperature, 45 parts by weight of isocyanate-terminated polybutadiene, 15 parts by weight of di(undecyl) phthalate, 35 parts by weight of silica powder with a median particle size of 10 µm, 4 parts by weight of bis[(triethoxy)propyl]amine, and 0.5 parts by weight of p-toluenesulfonyl isocyanate were mixed according to the method described above for preparing component B, and their viscosity was tested.
[0029] After the A and B components were mixed in a 1:1 ratio, samples were prepared and tested sequentially for water vapor transmission rate, tensile strength, elongation at break, and appearance of the junction box after DH1000h.
[0030] Comparative Example 2 Component A consists of 49 parts by weight of hydroxyl-terminated polybutadiene with a molecular weight (Mn) of 1800; 35 parts by weight of silica powder with a median particle size of 10 µm; 15 parts by weight of di(undecyl) phthalate; 0.5 parts by weight of UV absorber UV234; 0.5 parts by weight of antioxidant 1010; and 0.2 parts by weight of dibutyltin dilaurate. These components were mixed according to the method described above for preparing Component A, and their viscosity was tested.
[0031] Component B: 100 parts by weight of hydroxyl-terminated polybutadiene, Mn1800; 26.7 parts by weight of toluene diisocyanate, with an isocyanate to hydroxyl molar ratio of 2.3:1. Isocyanate-terminated polybutadiene was synthesized according to the termination reaction conditions. After cooling to room temperature, 42 parts by weight of isocyanate-terminated polybutadiene, 10 parts by weight of alkoxy-terminated polybutadiene, 12 parts by weight of di(undecyl) phthalate, 35 parts by weight of silica powder with a median particle size of 10 µm, and 0.5 parts by weight of p-toluenesulfonyl isocyanate were mixed according to the method described above for preparing Component B, and their viscosity was tested.
[0032] After the A and B components were mixed in a 1:1 ratio, samples were prepared and tested sequentially for water vapor transmission rate, tensile strength, elongation at break, and appearance of the junction box after DH1000h.
[0033] Comparative Example 3 Component A: 49 parts by weight of polypropylene glycol (molecular weight Mn 1800); 35 parts by weight of silica powder (median particle size 10µm); 15 parts by weight of di(undecyl) phthalate; 0.5 parts by weight of UV absorber UV234; 0.5 parts by weight of antioxidant 1010; and 0.2 parts by weight of dibutyltin dilaurate. These components were mixed according to the method described above for preparing Component A, and their viscosity was tested.
[0034] Component B: 100 parts by weight of polypropylene glycol, Mn1800; 20.3 parts by weight of toluene diisocyanate, with an isocyanate to hydroxyl molar ratio of 2.3:1. Isocyanate-terminated polyether polyol was synthesized according to the end-capping reaction conditions. After cooling to room temperature, 40 parts by weight of isocyanate-terminated polyether polyol, 10 parts by weight of alkoxy-terminated polybutadiene, 10 parts by weight of di(undecyl) phthalate, 35 parts by weight of silica powder with a median particle size of 10 µm, 4 parts by weight of bis[(triethoxy)propyl]amine, and 0.5 parts by weight of p-toluenesulfonyl isocyanate were mixed according to the method described above for preparing component B, and their viscosity was tested.
[0035] After the A and B components were mixed in a 1:1 ratio, samples were prepared and tested sequentially for water vapor transmission rate, tensile strength, elongation at break, and appearance of the junction box after DH1000h.
[0036] The data obtained from the tests of Examples 1-3 and Comparative Examples 1-3 are shown in Table 1.
[0037] Table 1
[0038] Conclusion: The experimental data above shows that to achieve low water vapor transmission rate in potting compounds, a polyolefin structure needs to be introduced into the main chain design of the polyol. The most common is the polybutadiene structure. This is because the polyolefin main chain has a carbon-carbon structure, strong hydrophobicity, and short side chains, allowing for a tight molecular chain arrangement. Therefore, compared to the hydrophilic structure of polyols, the water vapor transmission rate is much lower. The hydrophobic structure also provides better resistance to damp heat and higher strength retention after DH aging. Longer polyolefin molecular chains and larger molecular weights result in better hydrophobicity, lower water vapor transmission rate, and better water blocking. However, increased molecular weight leads to increased viscosity, which can affect the filling effect of the potting compound. Therefore, a balance needs to be struck between molecular weight and viscosity. Furthermore, for the potting system, good adhesion and aging resistance to the junction box are also crucial. The selection and combination of alkoxy-terminated polybutadiene and coupling agents are key factors affecting substrate adhesion.
[0039] All other raw materials or structures not specifically described in this invention already exist in the prior art and can be purchased directly from the market.
[0040] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. 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 potting compound, characterized in that, The materials used in the preparation include: Component A includes a polyol, a first filler, a first plasticizer, an antioxidant, and a catalyst; and, Component B includes isocyanate-terminated polyol, alkoxy-terminated polybutadiene, a second filler, a second plasticizer, a coupling agent, and a dehydrating agent.
2. The potting compound according to claim 1, characterized in that, In component A, the polyol is 40-50 parts by weight, the first filler is 30-40 parts by weight, the first plasticizer is 10-20 parts by weight, the antioxidant is 1-3 parts by weight, and the catalyst is 0.1-1 parts by weight. In component B, the weight percentages of isocyanate-terminated polyol are 40-50 parts, the weight percentages of alkoxy-terminated polybutadiene are 10-20 parts, the weight percentages of the second filler are 30-40 parts, the weight percentages of the second plasticizer are 10-20 parts, the weight percentages of the coupling agent are 1-10 parts, and the weight percentages of the dehydrating agent are 0.1-1 parts.
3. The potting compound according to claim 1, characterized in that, The polyol includes at least one of hydroxyl-terminated polybutadiene and hydroxyl-terminated hydrogenated polybutadiene; and / or The molecular weight of the polyol is 500-2900.
4. The potting compound according to claim 1, characterized in that, Both the first and second fillers comprise at least one of heavy calcium carbonate, aluminum hydroxide, alumina, and silica powder; and / or, The particle size of both the first and second fillers is 5-20µm.
5. The potting compound according to claim 1, characterized in that, The first plasticizer and the second plasticizer each include at least one of phthalate, di(2-ethylhexyl) adipic acid, di(2-ethylhexyl) sebacate, di(2-ethylhexyl) azelaate, diol benzoate, and phosphate sulfonate.
6. The potting compound according to claim 1, characterized in that, The anti-aging agent includes an ultraviolet light absorber and an antioxidant. The ultraviolet light absorber includes at least one of benzophenone, triazole, or triazine, and the antioxidant includes at least one of 1010, 168, and 626.
7. The potting compound according to claim 1, characterized in that, The isocyanate-terminated polyols contain at least one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate. The isocyanate-terminated polyol includes hydroxy-terminated polybutadiene, hydroxy-terminated hydrogenated polybutadiene, or hydroxy-terminated polyisobutylene. The isocyanate-terminated polyol has a molar ratio of isocyanate to hydroxyl groups of the polyol of (2-2.5):
1.
8. The potting compound according to claim 1, characterized in that, The alkoxy-terminated polybutadiene includes propyltrimethoxysilane, propyltriethoxysilane, or propylmethyldimethoxysilane.
9. The potting compound according to claim 1, characterized in that, The coupling agent comprises at least one selected from propyltrimethoxysilane isocyanate, propyltriethoxysilane isocyanate, n-butylaminopropyltrimethoxysilane, bis[(triethoxy)propyl]amine, 3-(1,3-dimethylbutene)aminopropyltriethoxysilane, N,N-diethyl-3-aminopropyltrimethoxysilane, and mercaptosilane; and / or The dehydrating agent includes molecular sieves or p-toluenesulfonyl isocyanate; and / or... The catalyst includes stannous octoate or dibutyltin dilaurate.
10. The method for preparing the potting compound according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Mix the polyol, the first filler, the first plasticizer, the antioxidant, and the catalyst to obtain component A; S2. Mix isocyanate-terminated polyol, alkoxy-terminated polybutadiene, second filler, second plasticizer, coupling agent and dehydrating agent to obtain component B; S3. Mix component A and component B to obtain potting compound.