Two-component silicone potting materials and their applications

Abstract

The present invention provides a two-component silicone potting material and its application. Among them, the two-component silicone potting material includes component A and component B. By weight, component A includes 90 to 100 parts of base material, 5 to 10 parts of curing agent, and 0 to 2.5 parts of auxiliary agent. Component B includes 5 to 10 parts of modified silicone oil, 90 to 100 parts of crosslinking agent, and 0.8 to 1.5 parts of catalyst. The base material includes a heat-conducting filler modified with a sulfur-containing silane coupling agent and a hydroxyl-terminated polydimethylsiloxane, and the crosslinking agent includes a silane containing an active amino group. This two-component silicone potting material can be stored stably for a long time and can achieve deep curing rapidly at room temperature. It is especially suitable for potting of photovoltaic junction boxes. The cured silicone potting material has special adhesion to the substrate of the junction box. The formed colloid has low hardness and good toughness, can effectively protect the electronic components in the junction box from the influence of water vapor and dust, and can withstand severe thermal shock.

Description

Technical Field

[0001] The present invention relates to the technical field of silicone products, and particularly to a two-component silicone potting material. Background Art

[0002] Silicone products refer to a class of products containing high-polymer molecules with a chain structure connected by Si-O (silicon-oxygen) bonds, and their main component is linear polysiloxane with a high molar mass. Silicone rubber is one of the largest and most widely used categories of silicone products. After vulcanization, silicone rubber has excellent high and low temperature resistance, weather resistance, water repellency, electrical insulation, physiological inertness, etc., and has been widely used in national defense, military, medical and health, industrial and agricultural production, and people's daily lives. Silicone rubber can be divided into two major categories according to its vulcanization temperature: high temperature (heating) vulcanization type and room temperature vulcanization type. High temperature rubber is mainly used to manufacture various silicone rubber products, while room temperature rubber is mainly used as an adhesive, potting material or mold. However, when the current silicone rubber is used as a potting material, there are mostly defects such as poor adhesion to the substrate and poor compatibility between the potting glue filler and the resin, and it is not used in fields with strict requirements for potting performance.

[0003] For example, the current silicone rubber does not meet the use requirements of the potting material for photovoltaic junction boxes. The photovoltaic junction box is one of the core devices of the photovoltaic grid-connected power generation system, and it plays a key role in realizing the conversion of solar energy to electrical energy. Photovoltaic cell modules convert solar energy into direct current electrical energy, which is converted into alternating current electrical energy synchronized with the AC grid through an inverter and then sent into the grid to achieve grid-connected power generation. The photovoltaic junction box is exposed to harsh natural conditions such as sun exposure, high temperature, high humidity, and salt spray along with the solar panel. Its weather resistance requirements are very reliable. However, the stability of many key electronic components is greatly affected by environmental temperature and humidity. To ensure the normal operation and stable performance of the photovoltaic power system, it is crucial to design a good heat dissipation and sealing solution. High-power inverters and frequency converters generate a large amount of heat during operation due to the use of high-power and small-size chips, causing a sudden increase in the temperature of the entire photovoltaic power system. Therefore, it is necessary to solve the heat dissipation problem in order to maintain a stable operating temperature. Poor sealing of electronic components, entry of dust, water vapor or rain will cause short circuits, seriously shortening the service life of the photovoltaic panel.

[0004] During the assembly process of a photovoltaic junction box, a thermally conductive potting adhesive is used to wrap the entire component. This is equivalent to expanding the heat dissipation area, allowing a large amount of heat to be conducted away in a relatively short time. Therefore, the inductor temperature can be reduced, ensuring that it operates in a relatively constant ambient temperature and reducing the occurrence of capacity decline due to aging and cracking when the temperature rises. At the same time, it also plays a sealing role, preventing the entry of dust, water vapor or rain, ensuring the stability of the inverter, and greatly improving the lifespan of the inverter. However, the application range of ordinary high thermal conductivity potting adhesives is relatively wide. In the potting applications of high-power integrated devices, problems such as large thermal expansion coefficients, broken bonding wires, slow curing of the edge thin layer, which seriously restrict industrial production efficiency, poor adhesion between the potting adhesive and the substrate resulting in poor sealing, and poor compatibility between the potting adhesive filler and the resin resulting in delamination often occur. Summary of the Invention

[0005] Based on the above problems, the purpose of the present invention is to provide a two-component silicone potting material and its application. This two-component silicone potting material can be stored stably for a long time and can achieve deep curing quickly at room temperature. It is especially suitable for the potting of photovoltaic junction boxes. The cured silicone potting material has special adhesion to the junction box substrate. The formed colloid has low hardness and good toughness, can effectively protect the electronic components of the junction box from the influence of water vapor and dust, and can withstand severe thermal shock.

[0006] To achieve the above purpose, on the one hand, the present invention provides a two-component silicone potting material, including component A and component B. By weight, component A includes 90 - 100 parts of base material, 5 - 10 parts of curing agent, and 0 - 2.5 parts of auxiliary agent. Component B includes 5 - 10 parts of modified silicone oil, 90 - 100 parts of cross-linking agent, and 0.8 - 1.5 parts of catalyst. The base material includes a thermally conductive filler modified by a sulfur-containing silane coupling agent and a hydroxyl-terminated polydimethylsiloxane, and the cross-linking agent includes a silane containing active amino groups.

[0007] As a technical solution of the present invention, the mass ratio of component A to component B is 6:0.95 - 1.05.

[0008] As a technical solution of the present invention, the silane containing active amino groups can be prepared by mixing an alkylalkoxysilane and an amino silane coupling agent in proportion, heating and reacting, and then adding tetraethyl orthosilicate after cooling.

[0009] As a technical solution of the present invention, the alkylalkoxysilane includes at least one of methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, and propyltriethoxysilane.

[0010] As a technical solution of the present invention, the amino silane coupling agent includes at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, diethylenetriaminepropyltrimethoxysilane, and bis(3-trimethoxysilylpropyl)amine.

[0011] As a technical solution of the present invention, the sulfur-containing silane coupling agent includes at least one of bis-[3-(triethoxysilyl)propyl]-disulfide, bis-[3-(triethoxysilyl)propyl]-tetrasulfide, and γ-mercaptopropyltrimethoxysilane.

[0012] As a technical solution of the present invention, by weight, the base material includes 15-30 parts of first hydroxyl-terminated polydimethylsiloxane, 10-20 parts of second hydroxyl-terminated polydimethylsiloxane, and 60-70 parts of heat-conducting filler modified with sulfur-containing silane coupling agent.

[0013] As a technical solution of the present invention, the heat-conducting filler includes at least one of aluminum hydroxide, alumina, and kaolin.

[0014] As a technical solution of the present invention, the first hydroxyl-terminated polydimethylsiloxane has a viscosity of 1000-3000 mPa·s, and its structural formula is as shown in Formula I. The second hydroxyl-terminated polydimethylsiloxane has a viscosity of 350-750 mPa·s, and its structural formula is as shown in Formula II, where 100 ≤ m ≤ 300 and 10 ≤ n ≤ 50.

[0015]

[0016] As a technical solution of the present invention, the modified silicone oil includes methyl-terminated polydimethylsiloxane or polyether-modified silicone oil.

[0017] As a technical solution of the present invention, the auxiliary agent includes a colorant, and the colorant includes at least one of titanium dioxide, carbon black, iron oxide red, phthalocyanine blue, and phthalocyanine green.

[0018] As a technical solution of the present invention, the curing agent includes propylene glycol monolaurate.

[0019] As a technical solution of the present invention, the catalyst includes at least one of stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, and dioctyltin dilaurate.

[0020] On the other hand, the present invention provides an application of a two-component silicone potting material in a photovoltaic junction box.

[0021] In the technical solution adopted by the present invention, the base material includes a heat-conducting filler modified with a sulfur-containing silane coupling agent. The modified heat-conducting filler has good compatibility with the hydroxyl-terminated polydimethylsiloxane, can delay the sedimentation time of the heat-conducting filler during storage, reduce the abrasion time, lower the viscosity of the system, and enhance the adhesion of the potting adhesive system to the base material. The cross-linking agent includes a silane containing an active amino group, and the active amino group can participate in cross-linking and curing. Under the action of a catalyst, it can react with the hydroxyl-terminated polydimethylsiloxane to achieve molecular chain extension and achieve good adhesion to the base material. At the same time, the densely distributed amino groups in the cross-linking agent can decompose the curing agent to release small molecules such as water to promote deep curing of the system. Therefore, the two-component silicone potting material of the present invention has a soft and elastic texture after curing, has special adhesion to the junction box base material, has a low hardness and good toughness of the formed colloid, can effectively protect the electronic components of the junction box from the influence of water vapor and dust, and can withstand severe thermal shock. Detailed Embodiments

[0022] The two-component silicone potting material of the present invention includes component A and component B. The mass ratio of component A to component B is 6:0.95 to 1.05. As an example, the mass ratio of component A to component B can be but is not limited to 6:0.95, 6:1, 6:1.05.

[0023] By weight, component A includes 90 to 100 parts of base material, 5 to 10 parts of curing agent, and 0 to 2.5 parts of auxiliary agent. The base material can be but is not limited to 90 parts, 91 parts, 92 parts, 93 parts, 94 parts, 95 parts, 96 parts, 97 parts, 98 parts, 99 parts, 100 parts. The base material includes a heat-conducting filler modified with a sulfur-containing silane coupling agent and hydroxyl-terminated polydimethylsiloxane. Further, the base material includes 15 to 30 parts of the first hydroxyl-terminated polydimethylsiloxane, 10 to 20 parts of the second hydroxyl-terminated polydimethylsiloxane, and 60 to 70 parts of the heat-conducting filler modified with a sulfur-containing silane coupling agent. The first hydroxyl-terminated polydimethylsiloxane can be but is not limited to 15 parts, 17 parts, 19 parts, 20 parts, 21 parts, 23 parts, 25 parts, 27 parts, 29 parts, 30 parts. The viscosity of the first hydroxyl-terminated polydimethylsiloxane is 1000 to 3000 mPa·s, and its structural formula is as shown in formula I, where 100 ≤ m ≤ 300.

[0024]

[0025] The second hydroxyl-terminated polydimethylsiloxane can be but is not limited to 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts. The viscosity of the second hydroxyl-terminated polydimethylsiloxane is 350 to 750 mPa·s, and its structural formula is as shown in formula II, where 10 ≤ n ≤ 50.

[0026]

[0027] The sulfur-containing silane coupling agent-modified thermal conductive filler can be, but is not limited to, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, or 70 parts. The sulfur-containing silane coupling agent-modified thermal conductive filler can be obtained by compounding a thermal conductive filler (including, but not limited to, aluminum hydroxide, alumina, kaolin) and a sulfur-containing silane coupling agent in a certain proportion, heating and reacting at a suitable temperature for a certain period of time, cooling to another temperature, and adding an ethanol solution of glacial acetic acid to adjust the pH value and reacting. The sulfur-containing silane coupling agent includes at least one of bis-[3-(triethoxysilyl)propyl]-disulfide, bis-[3-(triethoxysilyl)propyl]-tetrasulfide, and γ-mercaptopropyltrimethoxysilane.

[0028] The curing agent can be, but is not limited to, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts. The curing agent includes propylene glycol monolaurate. The auxiliary agent can be, but is not limited to, 0 parts, 0.3 parts, 0.7 parts, 1.0 parts, 1.5 parts, 2.0 parts, or 2.5 parts. The auxiliary agent can be a colorant, and the colorant includes at least one of titanium dioxide, carbon black, iron oxide red, phthalocyanine blue, and phthalocyanine green. Propylene glycol monolaurate can react according to Reaction 1 under the action of a cross-linking agent (amino silane) to release small molecules such as water and promote deep curing of the system.

[0029]

[0030] Component B includes 5 - 10 parts of modified silicone oil, 90 - 100 parts of cross-linking agent, and 0.8 - 1.5 parts of catalyst. The modified silicone oil can be, but is not limited to, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts. The modified silicone oil includes methyl-terminated polydimethylsiloxane or polyether-modified silicone oil. The catalyst can be, but is not limited to, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, or 1.5 parts. The catalyst includes at least one of stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, and dioctyltin dilaurate.

[0031] The crosslinking agent can be, but is not limited to, 90 parts, 91 parts, 92 parts, 93 parts, 94 parts, 95 parts, 96 parts, 97 parts, 98 parts, 99 parts, or 100 parts. The crosslinking agent includes a silane containing an active amino group. The silane containing an active amino group can be prepared by proportionally blending an alkylalkoxysilane and an aminosilane coupling agent, followed by heating the reaction mixture and then cooling it before adding tetraethyl orthosilicate. The alkylalkoxysilane includes at least one of methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, and propyltriethoxysilane. The aminosilane coupling agent includes at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, diethylenetriaminepropyltrimethoxysilane, and bis(3-trimethoxysilylpropyl)amine.

[0032] Generally, a simple mixture of an alkylalkoxysilane and an aminosilane coupling agent needs to be used immediately after preparation. If it is left standing for more than 2 hours, white crystals will precipitate, consuming the alkoxy groups. After mixing the glue, it will cause the surface drying time to become slower, the adhesion to the plastic substrate to decrease, the flexibility of the colloid to change, resulting in an increase in hardness, a decrease in tensile strength, and a decrease in elongation. In the present invention, however, after proportionally blending the alkylalkoxysilane and the aminosilane coupling agent, heating the reaction mixture, cooling it, and then adding tetraethyl orthosilicate, the alkylalkoxysilane and the aminosilane coupling agent react according to Reaction II to form a silane with densely distributed amino groups. Using this silane as a crosslinking agent, it can be stored for 6 months, and its performance remains unchanged during the storage period. During its use, a one-time feeding reduces the introduction of water vapor caused by multiple openings during immediate preparation, which would otherwise lead to a decrease in the shelf life of the finished glue. Moreover, compared with simple mixing, it can improve the bonding performance of the finished glue to the plastic substrate.

[0033]

[0034]

[0035] For the two-component organosilicon potting material of the present invention, during preparation, first mix the components of the base material to obtain the base material for standby; then mix the components of Component A to obtain Component A; finally, mix the components of Component B to obtain Component B.

[0036] To better illustrate the purpose, technical solution, and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that the methods described in the following embodiments are further explanatory descriptions of the present invention and should not be regarded as limitations to the present invention.

[0037] (1) Description of the source of substances

[0038] The first hydroxyl-terminated polydimethylsiloxane 1#: Shandong Dongyue Silicone Materials Co., Ltd., RTV-107-10, viscosity is 1000 mPa.s.

[0039] The first hydroxyl-terminated polydimethylsiloxane 2#: Shandong Dongyue Silicone Materials Co., Ltd., RTV-107-25, viscosity 2500 mPa.s.

[0040] Second hydroxyl-terminated polydimethylsiloxane 1#: Guangzhou Laibao Silicon Materials Co., Ltd., LB-35, hydroxyl content 2.0%, viscosity 350 mPa.s.

[0041] Second hydroxyl-terminated polydimethylsiloxane 2#: Guangzhou Laibao Silicon Materials Co., Ltd., LB-75, hydroxyl content 1.2%, viscosity 750 mPa.s.

[0042] Aluminum hydroxide: Henan Tianma New Materials Co., Ltd., median particle size 25 μm.

[0043] Alumina: Henan Tianma New Materials Co., Ltd., spherical, median particle size 10 μm.

[0044] Kaolin: Jincheng Kaolin Products Co., Ltd., JD-80A.

[0045] Methyltrimethoxysilane: Qufu Chenguang Chemical Co., Ltd., purity 99%.

[0046] Ethyltriethoxysilane: Qufu Chenguang Chemical Co., Ltd., purity 99%.

[0047] γ-Aminopropyltriethoxysilane: Qufu Chenguang Chemical Co., Ltd., purity 99%.

[0048] Diethylenetriaminopropyltrimethoxysilane: Qufu Chenguang Chemical Co., Ltd., purity 99%.

[0049] Bis(3-trimethoxysilylpropyl)amine: Qufu Chenguang Chemical Co., Ltd., purity 99%.

[0050] Bis-[3-(triethoxysilyl)propyl]-tetrasulfide: Hubei Jianghan Fine Chemical Co., Ltd., purity 95%.

[0051] Phthalocyanine green: Foshan Carle New Materials Co., Ltd.

[0052] Polyether modified silicone oil 1#: Ningbo Runhe High-tech Materials Co., Ltd., RHC-300, viscosity: 300mPa.s.

[0053] Polyether modified silicone oil 2#: Ningbo Runhe High-tech Materials Co., Ltd., RHC-230, viscosity: 200mPa.s.

[0054] Propylene glycol monolaurate: Hai'an Petrochemical Factory, Jiangsu Province, BPML.

[0055] Dibutyltin diacetate: Quzhou Ruierfeng Chemical Co., Ltd., Sn: 18.5 ± 0.5%.

[0056] (2) Preparation of sulfur - containing silane coupling agent - modified thermal conductive filler

[0057] The thermal conductive filler and the sulfur - containing silane coupling agent are compounded in a certain proportion and then heated and reacted at 110 °C for 30 min. After cooling to below 60 °C, an ethanol solution of glacial acetic acid is added to adjust the pH value to obtain the product. The composition of various modified fillers is shown in Table 1.

[0058] Table 1 Composition of modified fillers (parts by weight)

[0059]

[0060] (3) Preparation of base material

[0061] The sulfur - containing silane coupling agent - modified thermal conductive filler and hydroxyl - terminated polydimethylsiloxane are added to a kneader and kneaded evenly. Low - boiling substances are removed under reduced pressure at 125 °C to obtain the base material.

[0062] Table 2 Composition of base material (parts by weight)

[0063]

[0064]

[0065] (4) Preparation of Component A

[0066] According to the formula in Table 3, each component is added to a dynamic mixer and stirred and dispersed evenly to obtain Component A.

[0067] Table 3 Composition of Component A1# - A12# (parts by weight)

[0068]

[0069] (5) Preparation of cross - linker

[0070] The alkylalkoxysilane and the amino - silane coupling agent are compounded according to the formula in Table 4, heated and reacted at 100 - 110 °C, then cooled to 40 - 50 °C, and tetraethyl orthosilicate is added, and a small amount of pure water is added dropwise to obtain the product.

[0071] Table 4 Composition of cross - linker (parts by weight)

[0072]

[0073]

[0074] (6) Preparation of Component B

[0075] Add each component into a dynamic mixer according to the formulation in Table 5 and stir to disperse evenly to obtain Component B.

[0076] Composition of Component B1# - B7# in Table 5 (parts by weight)

[0077]

[0078] (7) Preparation of Two-component Organosilicon Encapsulant

[0079] Provide Component A and Component B according to the formulation in Table 6.

[0080] Composition of Two-component Organosilicon Encapsulant in Table 6 (parts by weight)

[0081]

[0082]

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 1 is that the modified filler 1# in Component A1# is replaced with a mixture of 50 parts of aluminum hydroxide, 30 parts of alumina, and 19 parts of kaolin.

[0085] Comparative Example 2

[0086] The difference between this comparative example and Example 1 is that the crosslinking agent 1# in Component B1# is replaced with a mixture of methyltrimethoxysilane and tetraethyl orthosilicate.

[0087] Comparative Example 3

[0088] The difference between this comparative example and Example 1 is that the modified filler 1# in Component A1# is replaced with a mixture of 50 parts of aluminum hydroxide, 30 parts of alumina, and 19 parts of kaolin, and the crosslinking agent 1# in Component B1# is replaced with a mixture of methyltrimethoxysilane and tetraethyl orthosilicate.

[0089] Comparative Example 4

[0090] The difference between this comparative example and Example 1 is that the crosslinking agent 1# in Component B1# is replaced with a mixture of γ-aminopropyltriethoxysilane and tetraethyl orthosilicate.

[0091] Comparative Example 5

[0092] The difference between this comparative example and Example 1 is that the crosslinking agent 1# in Component B1# is replaced with a mixture of methyltrimethoxysilane and γ-aminopropyltriethoxysilane.

[0093] The products prepared in Examples 1 to 16 and Comparative Examples 1 to 5 were subjected to performance tests, and the results are shown in Table 7. Among them, the respective test items and corresponding test methods are as follows.

[0094] Density: Tested with reference to GB / T13477-2002.

[0095] Viscosity: Tested with reference to GB / T10247-2008.

[0096] Operating time: Tested with reference to GB / T 10247-2008.

[0097] Surface drying time: Tested with reference to GB / T13477-2002.

[0098] Tensile strength: Tested with reference to GB / T528-2009.

[0099] Elongation at break: Tested with reference to GB / T528-2009.

[0100] Hardness: Tested with reference to GB / T531.1-2008.

[0101] Thermal conductivity: Tested with reference to GB / T10297-2015.

[0102] Flame retardancy: Tested with reference to ANSI UL94-2018.

[0103] Coefficient of linear expansion: Tested with reference to ASTM E831.

[0104] Volume resistivity: Tested with reference to GB / T31838.2-2019.

[0105] Dielectric strength: Tested with reference to GB / T1408.1-2016.

[0106] Thermal conductivity after high and low temperature cycling: Tested with reference to ISO22007-2; among them, ① Cured completely at 25°C for 7 days; ② Low temperature: -40°C, time: 30 min; high temperature: 85°C, time: 30 min; temperature conversion time: 5 min; number of cycles: 1000 times.

[0107] Thermal conductivity after double 85 aging: Tested with reference to ISO22007-2; among them, ① Cured completely at 25°C for 7 days; ② 85°C, 85% humidity for 1000 h.

[0108] Sealing after high and low temperature cycling: Tested with reference to GBT15905-1995.

[0109] Compatibility test: Place for 1 month and test the thickness of the lower layer caking material with a ruler.

[0110] Table 7 Performance test results

[0111]

[0112]

[0113] Continued from the table above

[0114]

[0115] Continued from the table above

[0116]

[0117]

[0118] From the results in Table 7, it can be seen that the two-component silicone potting materials of Examples 1 to 16 have suitable toughness (tensile strength can reach 1.41 to 1.68 MPa, and elongation at break can reach 50% to 66%) and relatively suitable hardness (Shore A) (30 to 45) after curing. The present invention uses silane containing active amino groups as a cross-linking agent, and the active amino groups can participate in cross-linking curing. Under the action of a catalyst, it can react with hydroxyl-terminated polydimethylsiloxane to achieve molecular chain extension and achieve good adhesion with the substrate. At the same time, the densely distributed amino groups in the cross-linking agent can decompose the curing agent to release small molecules such as water to promote deep curing of the system. After being modified with a sulfur-containing silane coupling agent, the thermal conductive filler has good compatibility with the hydroxyl-terminated polydimethylsiloxane, which can delay the sedimentation time of the thermal conductive filler during storage, reduce the abrasive time, reduce the viscosity of the system, and enhance the adhesion of the potting glue system to the substrate.

[0119] In Comparative Example 1, unmodified fillers were added, and the viscosity of the two-component silicone potting material increased significantly, and the anti-delamination performance was poor. After one month, a thick layer of sediment formed on the lower layer. In Comparative Examples 2 and 4, unreacted conventional cross-linking agents were added, and the deep curing rate decreased. The adhesion between the cured adhesive and the substrate was also weak. In Comparative Example 3, unmodified flame retardants and conventional cross-linking agents were added. The viscosity of the finished adhesive increased significantly, and the anti-delamination performance was poor. After one month, a thick layer of sediment formed on the lower layer. The adhesion between the cured adhesive and the substrate was also weak. After high and low temperature cycles, the seal showed colloid cracking, shrinkage, and debonding, indicating that the anti-delamination performance and debonding problems were not effectively improved, and the three-proof performance could not be kept stable for a long time. In Comparative Example 5, a mixture of methyltrimethoxysilane and γ-aminopropyltriethoxysilane was added as a cross-linking agent, which resulted in the precipitation of white crystals during storage, consumption of alkoxy groups, slower surface drying time, decreased adhesion to the plastic substrate, and changes in the flexibility of the colloid, resulting in increased hardness, decreased tensile strength, and decreased elongation.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it is not limited to the embodiments listed. Those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A two-component silicone potting material, characterized in that, It includes Component A and Component B. By weight parts, Component A includes 90 - 100 parts of base material, 5 - 10 parts of curing agent, and 0 - 2.5 parts of auxiliary agent. Component B includes 5 - 10 parts of modified silicone oil, 90 - 100 parts of crosslinking agent, and 0.8 - 1.5 parts of catalyst. The base material includes heat-conducting filler modified by sulfur-containing silane coupling agent and hydroxyl-terminated polydimethylsiloxane. The crosslinking agent includes silane containing active amino group. The silane containing active amino group is prepared by proportionally compounding alkylalkoxysilane and amino silane coupling agent, heating and reacting, then cooling and adding tetraethyl orthosilicate and water. The curing agent includes propylene glycol monolaurate.

2. The two-component silicone potting material according to claim 1, wherein The mass ratio of Component A to Component B is 6:0.95 - 1.

05.

3. The two-component silicone potting material according to claim 1, characterized in that, The alkylalkoxysilane includes at least one of methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, and propyltriethoxysilane.

4. The two-component silicone potting material according to claim 1, characterized in that, The amino silane coupling agent includes at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, diethylenetriaminepropyltrimethoxysilane, and bis(3-trimethoxysilylpropyl)amine.

5. The two-component silicone potting material according to claim 1, characterized in that, The sulfur-containing silane coupling agent includes at least one of bis-[3-(triethoxysilyl)propyl]-disulfide, bis-[3-(triethoxysilyl)propyl]-tetrasulfide, and γ-mercaptopropyltrimethoxysilane.

6. The two-component silicone potting material according to claim 1, characterized in that, By weight parts, the base material includes 15 - 30 parts of first hydroxyl-terminated polydimethylsiloxane, 10 - 20 parts of second hydroxyl-terminated polydimethylsiloxane, and 60 - 70 parts of heat-conducting filler modified by sulfur-containing silane coupling agent.

7. The two-component silicone potting material according to claim 6, characterized in that, The heat-conducting filler includes at least one of aluminum hydroxide, alumina, and kaolin. Or, the modified silicone oil includes methyl-terminated polydimethylsiloxane or polyether-modified silicone oil. Or, the catalyst includes at least one of stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, and dioctyltin dilaurate. Or, the auxiliary agent includes colorant, and the colorant includes at least one of titanium dioxide, carbon black, iron oxide red, phthalocyanine blue, and phthalocyanine green.

8. The two-component silicone potting material according to claim 6, characterized in that, The viscosity of the first hydroxyl-terminated polydimethylsiloxane is 1000 - 3000 mPa•s, and its structural formula is as shown in Formula I. The viscosity of the second hydroxyl-terminated polydimethylsiloxane is 350 - 750 mPa•s, and its structural formula is as shown in Formula II. Formula Ⅰ Formula Ⅱ Wherein, 100 ≤ m ≤ 300, 10 ≤ n ≤ 50.

9. Application of the two-component silicone potting material according to any one of claims 1 - 8 in a photovoltaic junction box.

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