Organosilicon three-proofing glue for outdoor power supply and energy storage equipment and preparation method thereof

Abstract

The invention relates to the technical field of three-proofing glue processing, in particular to organic silicon three-proofing glue for an outdoor power supply and energy storage equipment and a preparation method of the organic silicon three-proofing glue. The silicone rubber is prepared from the following raw materials in parts by weight: 40 to 60 parts of vinyl-terminated polydimethylsiloxane I, 30 to 70 parts of vinyl-terminated polydimethylsiloxane II, 10 to 20 parts of epoxy propoxy propyl-terminated polydimethylsiloxane, 5 to 10 parts of a fluorosilicone oil block copolymer, 30 to 60 parts of filler, 25 to 35 parts of hydrogen-containing silicone oil, 10 to 15 parts of a thixotropic agent, 3 to 5 parts of a cross-linking agent, 0.5 to 1 part of a catalyst and 1 to 2 parts of a stabilizer. The content of vinyl in the vinyl-terminated polydimethylsiloxane I is 0.3-0.6 wt%, and the viscosity of the vinyl-terminated polydimethylsiloxane I at the temperature of 25 DEG C is 1000-5000 mPa. S; the content of vinyl in the vinyl-terminated polydimethylsiloxane II is 1.0-2.5 wt%, and the viscosity of the vinyl-terminated polydimethylsiloxane II is 10000-50000 mPa.s at the temperature of 25 DEG C. The organosilicon three-proofing adhesive for the outdoor power supply and the energy storage equipment can be used for a long time in an environment of-60 DEG C, is not pulverized and stripped for a long time in a strong ultraviolet / salt mist / chemical corrosion environment, and can bear mechanical impact in transportation and operation.

Description

Technical Field

[0001] This application relates to the field of conformal coating technology, and more specifically, to an organosilicon conformal coating for outdoor power supplies and energy storage devices and its preparation method. Background Technology

[0002] As applications in outdoor power supplies, energy storage systems, new energy vehicles, and communication base stations extend to extreme environments such as high latitudes, high altitudes, high salt spray concentrations, and large diurnal temperature variations, the protection requirements for electronic circuit boards and their components are becoming increasingly stringent. Current technologies generally use acrylic, polyurethane, or epoxy conformal coatings, which provide moisture protection, salt spray protection, and dust protection under normal indoor or light outdoor conditions. However, when faced with extreme temperatures ranging from -40°C to +60°C, strong ultraviolet radiation, salt spray and chemical corrosion, vibration, and impact, these coatings are prone to cracking, powdering, peeling, or a sharp drop in insulation performance, leading to protective failure. Silicone conformal coatings, due to their excellent flexibility, wide temperature range stability, and electrical insulation, are considered an ideal alternative to traditional conformal coatings. Typical single-component silicone conformal coatings, based on silicone resin, form a transparent or semi-transparent elastic protective film on the surface of electronic circuit boards, providing multiple functions such as waterproofing, moisture protection, dustproofing, mildew prevention, salt spray protection, and electromagnetic shielding. However, practical application verification has shown that currently available commercially available silicone conformal coatings still have the following shortcomings: 1. Low-temperature embrittlement: When the ambient temperature is below -60℃, the elasticity of the adhesive layer decreases sharply, micro-cracks are generated, and the moisture-proof and dust-proof barrier is lost. 2. Ultraviolet aging: Under prolonged exposure to strong ultraviolet radiation in high-altitude or desert areas, the surface of silicone rubber is prone to powdering and cracking, and functional failure will occur within 2-3 years. 3. Salt spray / chemical corrosion: High concentrations of salt spray and corrosive gases such as SO and H2S penetrate the seaside and chemical industrial zones, causing blistering and peeling of the adhesive surface, creating a short-circuit hazard in the salt bridge; 4. Mechanical shock: Vibration or drops during transportation or operation can easily cause the low-modulus adhesive layer to be punctured or detached by sharp components, reducing overall reliability; In summary, existing silicone conformal coatings cannot provide long-term, stable, and comprehensive protection in extreme outdoor environments. There is an urgent need for a new type of silicone conformal coating that significantly improves ultra-low temperature toughness, UV aging resistance, salt spray chemical corrosion resistance, and mechanical durability. Summary of the Invention

[0003] To address the issue that existing silicone conformal coatings cannot provide long-term, stable, and comprehensive protection in extreme outdoor environments, this application provides a silicone conformal coating for outdoor power supplies and energy storage devices, as well as its preparation method.

[0004] In a first aspect, this application provides an organosilicon conformal adhesive for outdoor power supplies and energy storage devices, employing the following technical solution: An organosilicon conformal adhesive for outdoor power supplies and energy storage devices is prepared from the following raw materials in parts by weight: Vinyl-terminated polydimethylsiloxane I 40-60 parts Vinyl-terminated polydimethylsiloxane II 30-70 parts 10-20 parts of terminal epoxypropoxypropyl polydimethylsiloxane 5-10 parts of fluorosilicone block copolymer 30-60 parts of filler 25-35 parts of hydrogen-containing silicone oil 10-15 parts of thixotropic agent 3-5 parts crosslinking agent Catalyst 0.5-1 part, stabilizer 1-2 parts; The vinyl content of the terminal vinyl polydimethylsiloxane I is 0.3-0.6 wt%, and the viscosity at 25°C is 1000-5000 mPa·s; The vinyl content in the terminal vinyl polydimethylsiloxane II is 1.0-2.5 wt%, and the viscosity at 25°C is 10000-50000 mPa·s.

[0005] By adopting the above technical solution, the silicone conformal coating for outdoor power supplies and energy storage equipment has good low temperature resistance and can be used for a long time in an environment of -60℃. It does not powder or peel off for a long time in strong ultraviolet / salt spray / chemical corrosion environment, and can withstand mechanical impact during transportation and operation.

[0006] The compounding of vinyl-terminated polydimethylsiloxane I and vinyl-terminated polydimethylsiloxane II in this application forms a gradient crosslinking network by controlling the crosslinking density and segment regularity. The low-vinyl-content I provides flexible segments, inhibiting crystallization hardening at low temperatures; the high-vinyl-content II increases the overall strength by increasing crosslinking points, preventing a sudden drop in elasticity of a single siloxane below -40°C. Simultaneously, the use of a fluorosilicone block copolymer suppresses the crystallization problem of polydimethylsiloxane at low temperatures, ensuring that the conformal coating does not develop microcracks in extremely cold environments, and improving the integrity of the moisture-proof and dust-proof barrier by more than 90% compared to traditional products.

[0007] This application improves the structural stability and aging resistance of the conformal adhesive after curing by adding fluorosilicone block copolymers. Simultaneously, the three-dimensional cross-linked network formed by the hydrogen-containing silicone oil and terminal vinyl siloxanes further inhibits oxidative aging. Furthermore, the terminal epoxypropoxypropyl groups in the terminal epoxypropoxypropyl polydimethylsiloxane weaken the photochemical pyrolysis under ultraviolet light, resulting in a surface chalking rate of <5% and no cracking after 10,000 hours of ultraviolet aging testing, extending the service life by more than three times compared to traditional silicone adhesives.

[0008] The epoxy groups of terminally epoxypropyltrioxypropyl polydimethylsiloxane promote the chemical reaction between the conformal adhesive and the hydroxyl groups on the surface of the metal substrate, forming strong -Si-O-metal chemical bonds, which greatly improves the adhesion of the conformal adhesive. In a 1000-hour salt spray test, the peeling area of ​​the adhesive layer is less than 2%. At the same time, the fluorosilicone block copolymer reduces the surface energy of the conformal adhesive, reduces the adhesion of chemical substances, reduces erosion, and thus improves the corrosion resistance and chemical resistance of the conformal adhesive.

[0009] This application further improves the puncture resistance and modulus of the conformal adhesive after curing by adding fillers and using components such as vinyl-terminated polydimethylsiloxane I, vinyl-terminated polydimethylsiloxane II, epoxy-propylene-dimethylsiloxane, fluorosilicone block copolymer, and thixotropic agents. This reduces the brittle fracture of the conformal adhesive when punctured by sharp components. Preferably, the fluorosilicone block copolymer has the following structural formula: Where m = 50 - 100, n = 30 - 50.

[0010] By adopting the above technical solution, the structure of the fluorosilicone block copolymer is optimized, further reducing its low glass transition temperature and flexibility, effectively inhibiting low-temperature crystallization and hardening, so that the conformal coating retains its elasticity and is free of microcracks even when used at -40℃ after curing. Simultaneously, the conformal coating's ability to resist UV aging is further improved, enabling long-term outdoor use. The low surface energy fluorocarbon layer of this fluorosilicone block copolymer can block the penetration of salt spray and corrosive gases, enhancing its resistance to salt spray and chemical corrosion; when used with other components, it can further improve the conformal coating's impact resistance and puncture resistance mechanical durability under mechanical impact.

[0011] Preferably, the hydrogen-containing silicone oil has a hydrogen content of 0.8-1.2 mol% and a viscosity of 500-5000 mPa·s at 25°C.

[0012] By employing the above technical solution and optimizing the parameters of the hydrogen-containing silicone oil, an addition reaction is carried out with the vinyl groups of vinyl-terminated polydimethylsiloxane, epoxypropyleneoxypropyl polydimethylsiloxane, and fluorosilicone block copolymers to construct a three-dimensional cross-linked network. This enhances the overall strength, elasticity, and structural stability of the conformal coating, reduces the penetration channels of salt spray and corrosive gases, and improves its resistance to chemical corrosion. Simultaneously, it enables the conformal coating to more evenly transmit and disperse stresses from vibration and impact, reducing localized stress concentrations and improving its mechanical durability against punctures and detachment. The hydrogen-containing silicone oil regulates the cross-linking density, balancing the flexibility and strength of the conformal coating, preventing excessive cross-linking from causing low-temperature embrittlement, and synergistically ensuring toughness at ultra-low temperatures.

[0013] Preferably, the weight ratio of the terminal vinyl polydimethylsiloxane I to the terminal vinyl polydimethylsiloxane II is 1:(1-1.2), and the total weight of the two is in the weight ratio of the terminal epoxypropyloxypropyl polydimethylsiloxane to the terminal epoxypropyloxypropyl polydimethylsiloxane (6-8):1.

[0014] Through the above technical solution, the dosage of vinyl-terminated polydimethylsiloxane I, vinyl-terminated polydimethylsiloxane II, and epoxy-propylene-oxypropyl polydimethylsiloxane is further optimized, further enhancing the overall mechanical strength of the conformal adhesive and resisting mechanical impacts during transportation or operation. This effectively avoids the shortcomings of single siloxanes, which are either brittle at low temperatures or lack sufficient strength, constructing a gradient crosslinked network that balances flexibility and strength. Simultaneously, a balance between system compatibility and functional enhancement is achieved. This ratio allows the epoxy siloxane to be appropriately dispersed in the base system formed by I and II, avoiding disruption of the flexibility-strength balance constructed by I and II due to excessive proportions, while fully utilizing the role of its epoxy groups. Furthermore, it reacts with the hydroxyl groups on the surface of the metal substrate to form strong chemical bonds, significantly improving the adhesion of the adhesive layer and preventing peeling under salt spray or chemical corrosion. Finally, it helps to weaken the photochemical degradation of ultraviolet light, enhancing aging resistance. The synergistic effect of the two ratios allows the conformal adhesive to complement each other in core protective dimensions such as low-temperature resistance, mechanical properties, adhesion, and aging resistance, ensuring stable protective effects in extreme outdoor environments.

[0015] Preferably, the average particle size of the filler is 10-100 nm.

[0016] By adopting the above technical solutions and optimizing the average particle size of the filler, the puncture resistance and modulus of the conformal adhesive are further improved, effectively resisting the puncture impact of sharp components during transportation or operation, reducing the risk of brittle fracture, lowering the intrusion rate of corrosive media, and solving the problems of easy blistering and peeling of traditional adhesive layers. Simultaneously, it can assist the terminal epoxy propylene oxide polydimethylsiloxane in weakening the photochemical pyrolysis effect of ultraviolet light, reducing the generation of free radicals on the adhesive layer surface under ultraviolet irradiation, further improving the UV aging resistance of the adhesive layer, and extending its effective service life in extreme environments with strong ultraviolet radiation such as high altitudes and deserts.

[0017] Preferably, the crosslinking agent is a multifunctional siloxane crosslinking agent.

[0018] Preferably, the multifunctional siloxane crosslinking agent is at least one of methyltris(dimethylsiloxane), vinyltris(tert-butylperoxy)silane, and γ-glycidoxypropyltriethoxysilane.

[0019] By adopting the above technical solution, it can form multi-point crosslinks with vinyl-terminated polydimethylsiloxane I and II and epoxy-propylene-dimethylsiloxane. Compared with monofunctional crosslinking agents, this greatly improves the density and integrity of the crosslinking network, reduces network defects, and thus enhances the mechanical stability of the conformal adhesive, making it less prone to cracking or peeling under mechanical impact. Simultaneously, it allows the conformal adhesive to maintain flexibility to cope with low-temperature environments while also ensuring strength, adhesion, and resistance to environmental corrosion, guaranteeing long-term stable protective performance under extreme conditions.

[0020] Preferably, the stabilizer is composed of an oxidant and an anti-ultraviolet agent in a weight ratio of (3-5):1.

[0021] By adopting the above technical solution, the oxidant and UV stabilizer in the stabilizer are matched in a specific weight ratio to build a dual protection system of "antioxidant + UV protection" for the silicone conformal coating. This can significantly reduce the performance degradation of the conformal coating caused by oxidation or UV radiation, ensure that it maintains good elasticity, barrier properties and adhesion during long-term outdoor use, and extend the overall protection life.

[0022] Preferably, the thixotropic agent is hydrophobic fumed silica modified with a silane coupling agent.

[0023] By adopting the above technical solutions, the types of thixotropic agents are optimized to improve the high thixotropy of the conformal adhesive. When applied, the adhesive thins under shear, making it easy to flow and remove bubbles. When left to stand, it quickly recovers its high viscosity, preventing sagging and dripping, and ensuring uniform thick coating on vertical surfaces and crevices. At the same time, the adhesive is reinforced with a nano-hydrophobic silica skeleton to improve puncture resistance and edge coverage.

[0024] Secondly, this application provides a method for preparing an organosilicon conformal adhesive for outdoor power supplies and energy storage devices, using the following technical solution: A method for preparing an organosilicon conformal adhesive for outdoor power supplies and energy storage devices includes the following preparation steps: S1. Add vinyl-terminated polydimethylsiloxane I, vinyl-terminated polydimethylsiloxane II, epoxypropoxypropyl polydimethylsiloxane and fluorosilicone block copolymer to a reactor, and stir for 1-2 hours under nitrogen protection, 50-60℃ and 500-600 rpm to obtain the matrix resin. S2. Add filler and thixotropic agent to the matrix resin, heat to 70-80℃, stir at 800-1000rpm for 2-3 hours, and ultrasonically disperse for 5-10 minutes every 30 minutes during this period; S3. Cool to 30-60℃, add hydrogen-containing silicone oil, catalyst, stabilizer and crosslinking agent, stir for 40-60min, vacuum degas, and obtain organosilicon conformal adhesive for outdoor power supply and energy storage equipment.

[0025] By adopting the above technical solution, in stage S1, under nitrogen protection and suitable stirring conditions, the vinyl-terminated polydimethylsiloxane I / II, the epoxy-propylene-oxypropyl polydimethylsiloxane, and the fluorosilicone block copolymer can be fully integrated to form a uniform and stable matrix resin. This process also isolates oxygen, preventing damage to active groups due to oxidation, thus laying a solid foundation for the subsequent orderly structure of the crosslinking network and ensuring that the synergistic effect between matrix components is not interfered with by impurities. In stage S2, through heating and efficient stirring, combined with periodic ultrasonic dispersion, the agglomeration of fillers and thixotropic agents can be effectively broken, ensuring their uniform dispersion in the matrix resin. This not only avoids localized weak mechanical properties or protective gaps in the adhesive layer due to uneven dispersion but also enhances the compatibility between excipients and the matrix, ensuring the stable application of the thixotropic agent and significantly improving the impact and puncture resistance of the adhesive layer.

[0026] After cooling in the S3 stage, hydrogen-containing silicone oil, catalyst, and stabilizer are added to prevent the catalyst from reacting prematurely due to high temperature, ensuring the controllability of the system reaction. Subsequent vacuum degassing can completely remove air bubbles in the system, preventing the formation of pores after the adhesive layer cures. These pores will become channels for moisture and salt spray to penetrate. The degassing step can further enhance the barrier protection performance of the adhesive layer.

[0027] In summary, this application has the following beneficial effects: 1. Extremely low temperature resistance: It can maintain its elasticity at -60℃ without micro-cracks, and the integrity of the moisture-proof and dust-proof barrier is improved by more than 90% compared with traditional adhesives; 2. Ultra-long weather resistance: After 10,000 hours of UV aging, the powdering rate is less than 2%, with no cracking, and the service life is extended by more than 3 times; after 10,000 hours of salt spray peeling area is less than 5%, with good chemical corrosion resistance. 3. Excellent resistance to mechanical impact: puncture-resistant, drop-resistant, vibration-resistant, and not easily cracked during transportation and operation.

[0028] 4. Good adhesion: The epoxy groups of terminal epoxypropoxypropyl polydimethylsiloxane react chemically with the hydroxyl groups on the surface of the metal substrate to form strong -Si-O- metal chemical bonds, which greatly improves the adhesion of the conformal adhesive. Detailed Implementation Example

[0029] The terminal epoxypropyloxypropyl polydimethylsiloxane was purchased from Henan Huawen Chemical Co., Ltd., with CAS number 102782-97-8.

[0030] Example 1 An organosilicon conformal adhesive for outdoor power supplies and energy storage devices is prepared by the following method: S1. Add 400g of vinyl-terminated polydimethylsiloxane I, 700g of vinyl-terminated polydimethylsiloxane II, 100g of epoxypropoxypropyl polydimethylsiloxane, and 50g of fluorosilicone block copolymer to a reactor and stir for 1 hour under nitrogen protection at 50°C and 500 rpm to obtain the matrix resin. The vinyl content of vinyl-terminated polydimethylsiloxane I is 0.3 wt%, and its viscosity at 25°C is 1000 mPa·s. Vinyl-terminated polydimethylsiloxane II has a vinyl content of 1.0 wt% and a viscosity of 10000 mPa·s at 25°C. The structural formula of the fluorosilicone block copolymer is as follows: Where m = 50, n = 30; S2. Add 300g of filler (kaolin) and 100g of thixotropic agent to the matrix resin, heat to 70℃ and stir at 800rpm for 2h, and ultrasonically disperse for 5min every 30min during the process. S3. Cool down to 30℃, add 250g of hydrogen-containing silicone oil, 5g of catalyst (platinum catalyst, platinum content is 3000ppm), 10g of stabilizer and 30g of crosslinking agent (methyltris(dimethylsiloxane)silane), stir for 40min, vacuum degas, and obtain organosilicon conformal adhesive for outdoor power supply and energy storage equipment. The hydrogen content of the hydrogen-containing silicone oil is 0.8 mol%, and its viscosity at 25°C is 500 mPa·s. The stabilizer is composed of an oxidant (di-tert-butyl peroxide) and an anti-ultraviolet agent (2-(2'-hydroxy-5'-methylphenyl)benzotriazole) in a weight ratio of 3:1; The thixotropic agent is a hydrophobic fumed silica modified with vinyltriethoxysilane.

[0031] The difference between Examples 2-3 and Example 1 lies in the types, amounts, and parameters of raw materials used to prepare the silicone conformal coating for outdoor power supplies and energy storage devices. Specific differences are shown in Table 1. Table 1. Raw material types, dosages, and parameters for preparing silicone conformal coatings for outdoor power supplies and energy storage devices. Example 4 An organosilicon conformal adhesive for outdoor power supplies and energy storage devices. The difference between this embodiment and Embodiment 1 is that the weight ratio of 500g of vinyl-terminated polydimethylsiloxane I to 600g of vinyl-terminated polydimethylsiloxane II is 1:1.2, and the weight ratio of their total weight to 183g of epoxypropyloxypropyl polydimethylsiloxane is 6:1.

[0032] Example 5 An organosilicon conformal adhesive for outdoor power supplies and energy storage devices, the difference between this embodiment and Embodiment 1 is that: the weight ratio of 500g of vinyl-terminated polydimethylsiloxane I to 500g of vinyl-terminated polydimethylsiloxane II is 1:1, and the weight ratio of their total weight to 125g of epoxypropyloxypropyl polydimethylsiloxane is 8:1.

[0033] Example 6 An organosilicon conformal adhesive for outdoor power supplies and energy storage devices, the difference between this embodiment and Example 1 is that n=20 in the fluorosilicone block copolymer.

[0034] Comparative Example 1 A silicone conformal coating for outdoor power supplies and energy storage devices. The difference between this comparative example and Example 1 is that all vinyl-terminated polydimethylsiloxane I is replaced with vinyl-terminated polydimethylsiloxane II.

[0035] Comparative Example 2 A silicone conformal coating for outdoor power supplies and energy storage devices. The difference between this comparative example and Example 1 is that all vinyl-terminated polydimethylsiloxane II is replaced with vinyl-terminated polydimethylsiloxane.

[0036] Comparative Example 3 An organosilicon conformal adhesive for outdoor power supplies and energy storage devices. The difference between this comparative example and Example 1 is that the terminal epoxy propylene oxide polydimethylsiloxane is replaced with dimethyl silicone oil.

[0037] The dimethyl silicone oil was purchased from Jinan Guanlin New Materials Co., Ltd., and the model number is Dimethyl Silicone Oil 201.

[0038] Comparative Example 4 An organosilicon conformal adhesive for outdoor power supplies and energy storage devices. The difference between this comparative example and Example 1 is that the fluorosilicone block copolymer is replaced with dimethyl silicone oil.

[0039] Dimethyl silicone oil was purchased from Jinan Guanlin New Material Co., Ltd., model number Dimethyl Silicone Oil 201. Comparative Example 5 is an organosilicon conformal adhesive for outdoor power supplies and energy storage equipment. The difference between this comparative example and Example 1 is that the vinyl-terminated polydimethylsiloxane I is replaced with phenyl vinyl resin.

[0040] The phenyl vinyl resin has a viscosity of 1000 mPa·s at 25°C, an ethylene content of 0.3 wt%, and a degree of polymerization of 1000.

[0041] Detection methods / test methods The silicone conformal coatings prepared in Examples 1-6 and Comparative Examples 1-5 for outdoor power supplies and energy storage devices were coated onto PCB boards with a thickness of 100 μm and cured to obtain samples.

[0042] Low temperature toughness test: Place the sample in a high and low temperature alternating test chamber, set the temperature to -60℃, place for 2 hours, then thaw at room temperature, cycle 500 times, and observe whether the conformal coating has cracks or powdering.

[0043] Salt spray corrosion: Prepare a 5% NaCl solution, immerse the sample in it for 1000 hours, and test the proportion of the surface area corroded. Chemical corrosion: Refer to IEC 60068-2-42 (SO2 25ppm, 168h, observe the sample for corrosion, discoloration and other phenomena).

[0044] UV aging: Refer to ISO 4892-3 standard, UV-A 340nm, 10000h, calculate the proportion of chalking area; Adhesion: Refer to GB / T 9286 (cross-cut test); Mechanical impact: Refer to GB / T 2423.8 (1m drop × 1000 cycles) to observe whether the sample detaches, is punctured, or exhibits other phenomena. Experimental data are shown in Table 2. Table 2. Experimental data of Examples 1-6 and Comparative Examples 1-7 The above data shows that the silicone conformal coating for outdoor power supplies and energy storage devices prepared by the formula in this application can be used for a long time in extremely cold conditions at -60℃ without cracking, with a powdering rate of <2% after 10,000 hours of UV aging and a salt spray peeling area of ​​<2% after 1,000 hours. It has strong adhesion, good chemical corrosion resistance, and good mechanical impact resistance.

[0045] The experimental data from Example 1 and Comparative Examples 1-2 and 5 show that the gradient compounding of “low vinyl siloxane I + high vinyl siloxane II” enables the conformal coating to simultaneously meet the requirements of no cracking in extreme cold, long life and aging resistance, and high adhesion and impact resistance.

[0046] The experimental data from Example 1 and Comparative Examples 3-4 show that the combined use of terminal epoxy propylene oxide polydimethylsiloxane and fluorosilicone block copolymer is beneficial to improving the salt corrosion resistance, chemical corrosion resistance, aging resistance and low temperature resistance of the conformal adhesive, while also improving its adhesion performance.

[0047] The experimental data from Examples 1 and 4 show that optimizing the amounts of vinyl-terminated polydimethylsiloxane I, vinyl-terminated polydimethylsiloxane II, and epoxypropyltrioxypropylene polydimethylsiloxane is beneficial to improving the salt corrosion resistance and chemical corrosion resistance of the conformal coating.

[0048] The experimental data from Examples 1 and 5-6 show that n≥30 can ensure no cracks at -60℃ and provide the highest low-temperature toughness. n=20 can still meet other indicators such as salt spray, ultraviolet, and adhesion, but the low-temperature toughness shows marginal failure.

[0049] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A silicone conformal coating for outdoor power supplies and energy storage devices, characterized in that, It is prepared from the following raw materials in parts by weight: Vinyl-terminated polydimethylsiloxane I 40-60 parts, vinyl-terminated polydimethylsiloxane II 30-70 parts 10-20 parts of terminal epoxypropoxypropyl polydimethylsiloxane 5-10 parts of fluorosilicone block copolymer 30-60 parts of filler 25-35 parts of hydrogen-containing silicone oil 10-15 parts of thixotropic agent 3-5 parts crosslinking agent 0.5-1 part catalyst Stabilizer 1-2 parts; The vinyl content of the terminal vinyl polydimethylsiloxane I is 0.3-0.6 wt%, and the viscosity at 25°C is 1000-5000 mPa·s; The vinyl content in the terminal vinyl polydimethylsiloxane II is 1.0-2.5 wt%, and the viscosity at 25°C is 10000-50000 mPa·s.

2. The silicone conformal coating for outdoor power supplies and energy storage devices according to claim 1, characterized in that, The structural formula of the fluorosilicone oil block copolymer is as follows: Where m = 50 - 100, n = 30 - 50.

3. The silicone conformal coating for outdoor power supplies and energy storage devices according to claim 2, characterized in that: The hydrogen-containing silicone oil has a hydrogen content of 0.8-1.2 mol% and a viscosity of 500-5000 mPa·s at 25°C.

4. The silicone conformal coating for outdoor power supplies and energy storage devices according to claim 1, characterized in that: The weight ratio of the terminal vinyl polydimethylsiloxane I to the terminal vinyl polydimethylsiloxane II is 1:(1-1.2), and the total weight of the two is in the weight ratio of the terminal epoxypropyloxypropyl polydimethylsiloxane to the terminal epoxypropyloxypropyl polydimethylsiloxane (6-8):

1.

5. The silicone conformal coating for outdoor power supplies and energy storage devices according to claim 1, characterized in that: The average particle size of the filler is 10-100 nm.

6. The silicone conformal coating for outdoor power supplies and energy storage devices according to claim 1, characterized in that: The crosslinking agent is a multifunctional siloxane crosslinking agent.

7. The silicone conformal coating for outdoor power supplies and energy storage devices according to claim 1, characterized in that: The multifunctional siloxane crosslinking agent is at least one of methyltris(dimethylsiloxane), vinyltris(tert-butylperoxy)silane, and γ-glycidoxypropyltriethoxysilane.

8. The silicone conformal coating for outdoor power supplies and energy storage devices according to claim 1, characterized in that: The stabilizer is composed of an oxidant and an anti-ultraviolet agent in a weight ratio of (3-5):

1.

9. The silicone conformal coating for outdoor power supplies and energy storage devices according to claim 1, characterized in that: The thixotropic agent is a hydrophobic fumed silica modified with a silane coupling agent.

10. A method for preparing an organosilicon conformal adhesive for outdoor power supplies and energy storage devices as described in any one of claims 1-9, characterized in that, The preparation steps include the following: S1, adding vinyl-terminated polydimethylsiloxane I, vinyl-terminated polydimethylsiloxane II, epoxypropoxypropyl polydimethylsiloxane and fluorosilicone block copolymer to a reactor, and stirring for 1-2 hours under nitrogen protection, 50-60℃ and 500-600 rpm to obtain the matrix resin; S2. Add filler and thixotropic agent to the matrix resin, heat to 70-80℃, stir at 800-1000rpm for 2-3 hours, and ultrasonically disperse for 5-10 minutes every 30 minutes during this period; S3. Cool to 30-60℃, add hydrogen-containing silicone oil, catalyst, stabilizer and crosslinking agent, stir for 40-60min, vacuum degas, and obtain organosilicon conformal adhesive for outdoor power supply and energy storage equipment.

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