Silicone sealant for photovoltaic module with low water vapor transmittance and preparation method of silicone sealant

Abstract

The invention relates to the technical field of silicone rubber, and particularly discloses a low-water-vapor-transmittance silicone sealant for a photovoltaic module and a preparation method of the low-water-vapor-transmittance silicone sealant, and the low-water-vapor-transmittance silicone sealant comprises the following raw materials in parts by weight: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 10-30 parts of a plasticizer, 1-10 parts of rubber, 0.1-3 parts of a compatilizer, 100-200 parts of a filler, 5-15 parts of a cross-linking agent, 2-4 parts of a coupling agent and 1-2 parts of a catalyst. By introducing a rubber system and adding the compatilizer into the system, the water resistance and mechanical property of the silicone sealant are further improved, the problem of insufficient water resistance in an existing packaging scheme is solved, the water vapor barrier property of a solar electronic device can be greatly improved when the silicone sealant is applied to packaging of a photovoltaic module frame, and the service life of the solar electronic device is prolonged. And the problem of power attenuation caused by water vapor invasion in the long-term use process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of silicone rubber, and in particular to a silicone sealant for a photovoltaic module with low water vapor transmission rate and a preparation method thereof. Background Art

[0002] Room temperature vulcanized silicone sealant is widely used in construction, electronics, aerospace, automotive industry, medicine and health, new energy and other fields due to its excellent bonding and sealing properties, non-corrosiveness to substrates, ability to maintain good physical and electrical properties in harsh environments, and ease of use.

[0003] With the widespread application of double-glass photovoltaic modules, moisture barrier of the front and back panels is no longer a problem. However, the area between the two pieces of glass at the edge of the module has become the main channel for water vapor to invade. The aluminum frame and ordinary silicone seals commonly used in crystalline silicon modules can block liquid water, but they are far from meeting the higher requirements for water vapor molecules.

[0004] CN115772382A discloses a silicone sealant for photovoltaic modules resistant to humidity and heat aging, and its preparation method and application. By adding MQ silicone resin, modified filler and hydroxyl scavenger, the product still has good tensile strength, elasticity and tensile strength retention after 1000 hours of double 85 humidity and heat aging. However, its water vapor barrier rate is far lower than the industry performance requirements. Summary of the invention

[0005] The present invention provides a silicone sealant for photovoltaic modules with low water vapor permeability and a preparation method thereof, which can solve the problem of insufficient water barrier performance in existing packaging solutions. The silicone sealant applied to the packaging of photovoltaic module frames can greatly improve the water vapor barrier performance of solar electronic devices and reduce the power attenuation problem caused by water vapor intrusion during long-term use.

[0006] The technical solution of the present invention is to provide a silicone sealant for photovoltaic modules with low water vapor transmission rate, comprising the following raw materials in parts by weight: 100 parts of α, ω-dihydroxy polydimethylsiloxane, 10-30 parts of plasticizer, 1-10 parts of rubber, 100-200 parts of filler, 5-15 parts of cross-linking agent, 2-4 parts of coupling agent, and 1-2 parts of catalyst.

[0007] Optionally, the viscosity of the α,ω-dihydroxypolydimethylsiloxane at 25° C. is 20000-100000 mPa•s.

[0008] Optionally, the plasticizer is one or more of dimethyl silicone oil, phenyl silicone oil, hydrogen silicone oil or amino silicone oil, and has a viscosity of 100-1500 mPa•s at 25°C. Optionally, the filler is at least one of nano calcium carbonate, heavy calcium carbonate and fumed silica. Optionally, the crosslinking agent is at least one of methyl tributylacetoxime siloxane, vinyl tributylacetoxime siloxane, phenyl tributylacetoxime siloxane, tetrabutyl ketone oxime siloxane, dimethyl dibutyl ketone oxime siloxane, and methyl vinyl dibutyl ketone oxime siloxane. Optionally, the coupling agent is at least one of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltriethoxysilane; the catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetylacetonate, and dibutyltin diacetylacetonate; the catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetylacetonate, and dibutyltin diacetylacetonate. Optionally, the rubber is at least one of natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, butyl rubber, nitrile-butadiene rubber, hydrogenated nitrile-butadiene rubber and fluororubber.

[0009] Optionally, when the rubber is added, 0.1-3 parts of a raw material compatibilizer are also included; the compatibilizer is a polymer obtained by grafting natural rubber with silane. Optionally, the silane is one of 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyldimethoxysilane and 3-methacryloxypropyltriethoxysilane.

[0010] The present invention also relates to a method for preparing the silicone sealant, comprising the following steps: First, α,ω-dihydroxy polydimethylsiloxane, plasticizer, filler and rubber are mixed evenly, and vacuum dehydrated. Then, crosslinking agent, coupling agent and catalyst are added and mixed evenly in vacuum to obtain silicone sealant. The present invention has the following beneficial effects: The present invention further improves the water barrier performance and mechanical properties of silicone sealant through mixed modification of silicone rubber and carbon rubber, and at the same time adds a compatibilizer into the system to further improve the water barrier performance and mechanical properties of silicone sealant, thereby solving the problem of insufficient water barrier performance in existing packaging solutions. The packaging applied to the frame of photovoltaic modules can greatly improve the water vapor barrier performance of solar electronic devices and reduce the power attenuation problem caused by water vapor intrusion during long-term use.

[0011] The silicone sealant for moisture-heat-aging-resistant photovoltaic modules provided by the present invention is a single-component room-temperature vulcanized silicone sealant, which is easy to use and can be widely used for sealing and packaging solar photovoltaic modules. DETAILED DESCRIPTION

[0012] The experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials, reagents, etc. used in the following examples are commercially available products unless otherwise specified.

[0013] The present invention provides a silicone sealant for photovoltaic modules with low water vapor transmission rate, comprising the following raw materials in parts by weight: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 10-30 parts of plasticizer, 1-10 parts of rubber, 100-200 parts of filler, 5-15 parts of crosslinking agent, 2-4 parts of coupling agent and 1-2 parts of catalyst.

[0014] In some embodiments, the viscosity of the α,ω-dihydroxypolydimethylsiloxane at 25° C. is 20,000-100,000 mPa•s.

[0015] In some embodiments, the plasticizer is one or more of dimethyl silicone oil, phenyl silicone oil, hydrogen silicone oil or amino silicone oil, and has a viscosity of 100-1500 mPa•s at 25°C. In some embodiments, the filler is at least one of nano calcium carbonate, heavy calcium carbonate, and fumed silica. In some embodiments, the crosslinking agent is at least one of methyl tributylacetoxime siloxane, vinyl tributylacetoxime siloxane, phenyl tributylacetoxime siloxane, tetrabutyl ketone oxime siloxane, dimethyl dibutyl ketone oxime siloxane, and methyl vinyl dibutyl ketone oxime siloxane. In some embodiments, the coupling agent is at least one of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltriethoxysilane; the catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetylacetonate, and dibutyltin diacetylacetonate; the catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetylacetonate, and dibutyltin diacetylacetonate. In some embodiments, the rubber is at least one of natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, butyl rubber, nitrile-butadiene rubber, hydrogenated nitrile-butadiene rubber and fluororubber.

[0016] In some embodiments, the rubber further comprises 0.1-3 parts of a raw material compatibilizer when added; the compatibilizer is a polymer obtained by grafting natural rubber with silane. In a more preferred embodiment, the silane is one of 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyldimethoxysilane, and 3-methacryloxypropyltriethoxysilane.

[0017] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0018] Embodiment 1: 100 parts of 20000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica, 20 parts of styrene-butadiene rubber, and 1 part of a polymer obtained by grafting natural rubber with 3-methacryloxypropyltrimethoxysilane are put into a kneader and mixed evenly, and dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0019] Embodiment 2: 100 parts of 20000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica, 20 parts of chloroprene rubber, and 1 part of a polymer obtained by grafting natural rubber with 3-methacryloxypropyltrimethoxysilane are put into a kneader and mixed evenly, and dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0020] Embodiment 3: 100 parts of 20000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica, 20 parts of butyl rubber, and 1 part of a polymer obtained by grafting natural rubber with 3-methacryloxypropyltrimethoxysilane are put into a kneader and mixed evenly, and dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0021] Embodiment 4: 100 parts of 20000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica, 20 parts of nitrile rubber, and 1 part of a polymer obtained by grafting natural rubber with 3-methacryloxypropyltrimethoxysilane are put into a kneader and mixed evenly, and dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0022] Embodiment 5: Put 100 parts of 20000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica and 20 parts of nitrile rubber into a kneader and mix them evenly, dehydrate them at 100-120℃ for 180min with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0023] Embodiment 6: 120 parts of 20000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica, and 1 part of a polymer obtained by grafting natural rubber with 3-methacryloxypropyltrimethoxysilane are put into a kneader and mixed evenly, and dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0024] Embodiment 7: 120 parts of 20000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate and 1 part of fumed silica were put into a kneader and mixed evenly, and then dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa. After the high-temperature dehydration was completed, a basic rubber material was obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0025] Example 8 100 parts of 30000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica, 20 parts of styrene-butadiene rubber, and 1 part of a polymer obtained by grafting natural rubber with 3-methacryloxypropyltrimethoxysilane are put into a kneader and mixed evenly, and dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0026] Example 9 100 parts of 50000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica, 20 parts of styrene-butadiene rubber, and 1 part of a polymer obtained by grafting natural rubber with 3-methacryloxypropyltrimethoxysilane are put into a kneader and mixed evenly, and dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0027] Example 10 100 parts of 80000mPa•s α, ω-dihydroxy polydimethylsiloxane, 10 parts of dimethyl silicone oil, 100 parts of nano calcium carbonate, 1 part of fumed silica, 20 parts of styrene-butadiene rubber, and 1 part of a polymer obtained by grafting natural rubber with 3-methacryloxypropyltrimethoxysilane are put into a kneader and mixed evenly, and dehydrated at 100-120°C for 180 minutes with a vacuum degree of -0.08MPa, and after the high-temperature dehydration is completed, a basic rubber material is obtained; Add 9 parts of methyl tributylacetoximate silane, 3 parts of vinyl tributylacetoximate silane, 2 parts of KH-550 and 1 part of dibutyltin dilaurate into a planetary mixer, stir and disperse for 30 minutes under a vacuum degree of -0.1MPa to obtain a sealant product.

[0028] The water vapor transmission rate test results of the products obtained in the above examples are shown in Table 1 below. The test standard refers to GB 1037 "Test method for water vapor permeability of plastic films and sheets - cup method".

[0029] Table 1

[0030] By comparing Examples 1 to 4 with Example 7, it can be seen that adding carbon-based rubber to the silicone rubber system for blending modification further improves the water-blocking and mechanical properties of the silicone sealant. After blending modification, the carbon-based rubber is dispersed in the system, making the organic network denser. The carbon-based rubber fills the gaps between the fillers as an island phase structure. At the same time, it expands and contracts with the change of ambient temperature, further making the gaps in the sealant material denser to block water vapor. By comparing Example 4 with Example 5 and Example 7, it can be seen that adding a compatibilizer to the blending modification system promotes the compatibility of the interface between silicone rubber and carbon-based rubber, and improves the mechanical properties of the blending system.

[0031] The above embodiments describe the preferred implementation of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A silicone sealant for photovoltaic modules with low water vapor transmission rate, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of α,ω-dihydroxy polydimethylsiloxane, 10-30 parts of plasticizer, 1-10 parts of rubber, 0.1-3 parts of compatibilizer, 100-200 parts of filler, 5-15 parts of crosslinking agent, 2-4 parts of coupling agent and 1-2 parts of catalyst.

2. The silicone sealant according to claim 1, characterized in that: The viscosity of the α,ω-dihydroxy polydimethylsiloxane at 25° C. is 20000-100000 mPa•s.

3. The silicone sealant according to claim 1, characterized in that: The plasticizer is one or more of dimethyl silicone oil, phenyl silicone oil, hydrogen silicone oil or amino silicone oil, and has a viscosity of 100-1500 mPa•s at 25°C.

4. The silicone sealant according to claim 3, characterized in that: The filler is at least one of nano calcium carbonate, heavy calcium carbonate and fumed white carbon black.

5. The silicone sealant according to claim 1, characterized in that: The crosslinking agent is at least one of methyl tributylacetoximine siloxane, vinyl tributylacetoximine siloxane, phenyl tributylacetoximine siloxane, tetrabutyl ketone oxime siloxane, dimethyl dibutyl ketone oxime siloxane, and methyl vinyl dibutyl ketone oxime siloxane.

6. The silicone sealant according to claim 1, characterized in that: The coupling agent is at least one of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltriethoxysilane; the catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetylacetonate, and dibutyltin diacetylacetonate; the catalyst is at least one of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetylacetonate, and dibutyltin diacetylacetonate.

7. The silicone sealant according to any one of claims 1 to 6, characterized in that: The rubber is at least one of natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, butyl rubber, nitrile-butadiene rubber, hydrogenated nitrile-butadiene rubber and fluororubber.

8. The silicone sealant according to any one of claims 1 to 6, characterized in that: The compatibilizer is a polymer obtained by grafting silane onto natural rubber.

9. The silicone sealant according to claim 8, characterized in that: The silane is one of 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyldimethoxysilane and 3-methacryloxypropyltriethoxysilane.

10. The method for preparing the silicone sealant according to any one of claims 1 to 9, characterized in that: The following steps are involved: The α,ω-dihydroxypolydimethylsiloxane, plasticizer, filler, rubber and compatibilizer are first mixed uniformly and subjected to vacuum dehydration treatment, and then a crosslinking agent, a coupling agent and a catalyst are added and mixed uniformly in vacuum to obtain a silicone sealant.

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