An anti-aging insulating coating and its preparation method

Abstract

This application relates to the field of functional coatings technology, specifically disclosing an anti-aging insulating coating comprising the following components by weight: 28-40 parts polydimethylsiloxane, 15-18 parts aluminum hydroxide, 10-15 parts flame retardant, 5-8 parts silica, 2-4 parts composite anti-aging agent, 3-6 parts methyl tributanone oxime silane, 1.0-2.5 parts vinyl tributanone oxime silane, 0.1-0.4 parts 3-aminopropyltriethoxysilane, 0.3-0.6 parts propyltrimethoxysilane, 0.3-0.5 parts aminoethylaminopropyltrimethoxysilane, 0.2-0.6 parts dibutyltin dilaurate, and 40-46 parts diluent; wherein the composite anti-aging agent is a mixture of hindered amine light stabilizer, inositol hexaphosphate, and stearic acid-modified talc. The anti-aging insulating coating provided by this application exhibits long-term stable insulation performance and excellent anti-aging properties under extreme environments, showing promising application prospects.

Description

Technical Field

[0001] This application relates to the field of functional coatings technology, specifically to an anti-aging insulating coating and its preparation method. Background Technology

[0002] With the rapid development of power systems towards ultra-high voltage and extra-high voltage, power equipment is exposed to extreme outdoor environments for extended periods, facing multiple challenges such as high temperature, low temperature, alternating humid heat, strong ultraviolet radiation, and high electric field effects, which places stringent requirements on the performance of insulating coatings.

[0003] Existing electrical equipment insulating coatings mainly improve their performance by optimizing the proportions of components such as silicone resin and epoxy resin. However, they still have the following shortcomings: First, the insulation stability of the coating is limited. Under high and low temperature and high and low humidity cycling scenarios, the insulation resistance of the coating film is prone to decay, and the anti-corona ability of the coating film is insufficient, making it difficult to meet the requirements of long-term stable operation. Second, the anti-aging performance of the coating film is limited. Under long-term ultraviolet radiation, the coating is prone to degradation, yellowing, and cracking, resulting in a decline in insulation performance.

[0004] Therefore, developing an insulating coating for power equipment that exhibits long-term stable insulation performance and excellent anti-aging properties under extreme environments is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] In order to overcome the problems of poor long-term insulation stability and poor anti-aging performance of existing anti-aging insulating coatings under extreme environments, this application provides an anti-aging insulating coating and its preparation method.

[0006] In a first aspect, this application provides an anti-aging insulating coating, which adopts the following technical solution: An anti-aging insulating coating comprises the following components in parts by weight: 28-40 parts of polydimethylsiloxane, 15-18 parts of aluminum hydroxide, 10-15 parts of flame retardant, 5-8 parts of silica, 2-4 parts of composite anti-aging agent, 3-6 parts of methyl tributanone oxime silane, 1.0-2.5 parts of vinyl tributanone oxime silane, 0.1-0.4 parts of 3-aminopropyltriethoxysilane, 0.3-0.6 parts of propyltrimethoxysilane, 0.3-0.5 parts of aminoethylaminopropyltrimethoxysilane, 0.2-0.6 parts of dibutyltin dilaurate, and 40-46 parts of diluent; The polydimethylsiloxane is a mixture of polydimethylsiloxane with a viscosity of 1000-2000cp and polydimethylsiloxane with a viscosity of 18000-22000cp in a weight ratio of 1:(2-4); The composite anti-aging agent is a hindered amine light stabilizer, inositol hexaphosphate, and stearic acid-modified talc in a weight ratio of 1:(0.2-0.8):(1.5-3).

[0007] This application provides a method for preparing an anti-aging insulating coating with good insulation stability and long-term anti-aging properties by using specific polydimethylsiloxane and a composite anti-aging agent. This effectively solves the problem of rapid performance degradation and short service life of traditional power equipment insulating coatings under extreme environments. Specifically, this application uses low-viscosity and high-viscosity polydimethylsiloxane in a specific ratio. The low-viscosity component ensures the rheological properties of the coating, improves the ease of construction and film uniformity, and guarantees the stability of insulation performance. The high-viscosity component imparts a dense cross-linked structure to the coating, enhancing the mechanical strength and long-term anti-aging ability after film formation. The composite anti-aging agent is a mixture of hindered amine light stabilizer, inositol hexaphosphate, and stearic acid-modified talc in a specific ratio. Through chemical anti-aging and physical barrier methods, it provides two levels of protection, significantly improving the coating's resistance to ultraviolet radiation and damp heat aging, and significantly extending the coating's service life. Furthermore, crosslinking agents such as methyl tributanone oxime silane can further increase the crosslinking density of the coating, consolidating its insulation and anti-aging properties. The synergistic filling of aluminum hydroxide and silica can also construct a stable insulation network, making the coating less prone to cracking and peeling under extreme conditions such as high temperature and alternating humid heat. This ensures that the insulation resistance remains at a high level over a long period, meeting the insulation requirements of high-voltage power equipment during long-term operation. In summary, this application, through the combined use of multiple components, enables the coating to possess both stable insulation performance under extreme environments and long-term anti-aging capabilities, while maintaining good workability and environmental friendliness. It is suitable for the protection of power facilities under complex conditions such as high-voltage substations and transmission line towers, effectively reducing equipment maintenance costs and ensuring the safe and stable operation of the power system.

[0008] In this application, talc, as a layered silicate mineral, is modified with stearic acid. The resulting stearic acid-modified talc exhibits significantly improved hydrophobicity and further enhanced compatibility with polydimethylsiloxane. Adding stearic acid-modified talc to coatings can form a uniformly dispersed physical barrier layer, hindering the penetration of ultraviolet rays, oxygen, and water vapor, thereby improving the coating's anti-aging properties and long-term insulation stability.

[0009] In some embodiments, the weight ratio of the hindered amine light stabilizer, inositol hexaphosphate, and stearic acid modified talc can be 1:(0.2-0.4):2.5, 1:(0.2-0.6):2.5, 1:(0.2-0.8):2.5, 1:(0.4-0.6):2.5, 1:(0.4-0.8):2.5, 1:(0.6-0.8):2.5, 1:0.4:(1.5-2), 1:0.4:(1.5-2.5), 1:0.4:(1.5-3), 1:0.4:(2-2.5), 1:0.4:(2-3), or 1:0.4:(2.5-3).

[0010] In one specific implementation, the weight ratio of the hindered amine light stabilizer, inositol hexaphosphate, and stearic acid modified talc can also be 1:0.2:2.5, 1:0.4:2.5, 1:0.6:2.5, 1:0.8:2.5, 1:0.4:1.5, 1:0.4:2, or 1:0.4:3.

[0011] In some embodiments, the weight ratio of the polydimethylsiloxane with a viscosity of 1500 cp to the polydimethylsiloxane with a viscosity of 20000 cp can be 1:(2-3) or 1:(3-4).

[0012] In one specific implementation, the weight ratio of the polydimethylsiloxane with a viscosity of 1500 cp to the polydimethylsiloxane with a viscosity of 20000 cp can also be 1:2, 1:3 or 1:4.

[0013] Optionally, the polydimethylsiloxane is a mixture of polydimethylsiloxane with a viscosity of 1500cp and polydimethylsiloxane with a viscosity of 20000cp in a weight ratio of 1:3.

[0014] Optionally, the weight ratio of the hindered amine light stabilizer, inositol hexaphosphate and stearic acid modified talc is 1:(0.4-0.6):(2-2.5).

[0015] Optionally, the weight ratio of the hindered amine light stabilizer, inositol hexaphosphate, and stearic acid modified talc is 1:0.4:2.5.

[0016] Optionally, the method for preparing the stearic acid modified talc powder includes the following steps: adding 8-15g / 100mL of stearic acid ethanol solution to talc powder under stirring, then stirring at 80-90℃ for 30-40min, drying, and sieving to obtain modified talc powder; the weight ratio of talc powder to stearic acid is 100:(1-2).

[0017] Optionally, the diluent is an alcohol ether solvent.

[0018] Secondly, this application provides a method for preparing an anti-aging insulating coating, comprising the following steps: (1) Mix polydimethylsiloxane, aluminum hydroxide, flame retardant and silica evenly to form a premix; (2) Add methyl tributanone oxime silane, vinyl tributanone oxime silane and dibutyltin dilaurate to the premix, stir evenly to form an intermediate product; (3) Add composite anti-aging agent, diluent, 3-aminopropyltriethoxysilane, propyltrimethoxysilane and aminoethylaminopropyltrimethoxysilane to the intermediate product, mix thoroughly and filter to remove impurities to obtain anti-aging insulating coating.

[0019] In summary, this application has the following beneficial effects: This application uses a mixture of polydimethylsiloxane with a viscosity of 1000-2000cp and polydimethylsiloxane with a viscosity of 18000-22000cp in a weight ratio of 1:(2-4) as the main matrix of the coating, and hindered amine light stabilizer, inositol hexaphosphate and stearic acid modified talc in a weight ratio of 1:(0.2-0.8):(1.5-3) as composite anti-aging agents. It can obtain an anti-aging insulating coating with good UV resistance, good resistance to damp heat aging and good long-term insulation stability. When used for the protection of power facilities, it can effectively reduce equipment maintenance costs and ensure the safe and stable operation of the power system. Detailed Implementation

[0020] This application provides an anti-aging insulating coating comprising the following components in parts by weight: 28-40 parts of polydimethylsiloxane, 15-18 parts of aluminum hydroxide, 10-15 parts of flame retardant, 5-8 parts of silica, 2-4 parts of composite anti-aging agent, 3-6 parts of methyl tributanone oxime silane, 1.0-2.5 parts of vinyl tributanone oxime silane, 0.1-0.4 parts of 3-aminopropyltriethoxysilane, 0.3-0.6 parts of propyltrimethoxysilane, 0.3-0.5 parts of aminoethylaminopropyltrimethoxysilane, 0.2-0.6 parts of dibutyltin dilaurate, and 40-46 parts of diluent; The polydimethylsiloxane is a mixture of polydimethylsiloxane with a viscosity of 1000-2000 cp and polydimethylsiloxane with a viscosity of 18000-22000 cp in a weight ratio of 1:(2-4); the composite anti-aging agent is a hindered amine light stabilizer, inositol hexaphosphate, and stearic acid modified talc in a weight ratio of 1:(0.2-0.8):(1.5-3). Further, the weight ratio of the hindered amine light stabilizer, inositol hexaphosphate, and stearic acid modified talc is 1:(0.4-0.6):(2-2.5).

[0021] The preparation method of stearic acid modified talc powder in this application includes the following steps: adding dried talc powder to a high-speed mixer, and slowly adding 8-15g / 100mL of dissolved stearic acid ethanol solution (stearic acid is first dissolved in anhydrous ethanol and heated to 50℃ to aid dissolution) under stirring at 800-1000rpm; after the addition is completed, the temperature is raised to 80-90℃ and high-speed stirring is maintained for 30-40min; after the reaction is completed, the reactants are dried at 100-105℃ for 1 hour, and then ground and sieved through a 2000-mesh sieve to obtain stearic acid modified talc powder; wherein the weight ratio of talc powder to stearic acid is 100:(1-2).

[0022] The method for preparing the anti-aging insulating coating provided in this application includes the following steps: (1) Mix polydimethylsiloxane, aluminum hydroxide, flame retardant and silica evenly to form a premix; (2) Add methyl tributanone oxime silane, vinyl tributanone oxime silane and dibutyltin dilaurate to the premix, stir evenly to form an intermediate product; (3) Add composite anti-aging agent, diluent, 3-aminopropyltriethoxysilane, propyltrimethoxysilane and aminoethylaminopropyltrimethoxysilane to the intermediate product, mix thoroughly and filter to remove impurities to obtain anti-aging insulating coating.

[0023] In this application, the hindered amine light stabilizer is HALS 770; the diluent is diethylene glycol butyl ether; the raw materials, reagents, solvents, etc. used in this application are all commercially available.

[0024] The following describes this application in further detail with reference to preparation examples, embodiments, and performance testing. Preparation Example 1

[0025] Preparation Example 1 provides a stearic acid-modified talc powder.

[0026] The preparation method of the above-mentioned stearic acid modified talc powder includes the following steps: 100g of dried talc powder is added to a high-speed mixer, and under the stirring action of 1000rpm, 15mL of a 10g / 100mL stearic acid ethanol solution is slowly added dropwise (1.5g of stearic acid is dissolved in 15mL of anhydrous ethanol and heated to 50℃ to aid dissolution); after the addition is completed, the temperature is raised to 90℃ and high-speed stirring is maintained for 30min; after the reaction is completed, the reactants are dried at 100℃ for 1h, and then ground and sieved through a 2000-mesh sieve to obtain stearic acid modified talc powder; In Preparation Example 1, the weight ratio of talc to stearic acid was 100:1.5. Preparation Examples 2-3

[0027] Preparation Examples 2-3 provide stearic acid-modified talc powders respectively.

[0028] The difference between the above preparation example and preparation example 1 is that... In Preparation Example 2, 1 g of stearic acid was added and dissolved in 10 mL of anhydrous ethanol to obtain a 10 mL, 10 g / 100 mL stearic acid ethanol solution. In Preparation Example 3, 2g of stearic acid was added and dissolved in 20mL of anhydrous ethanol to obtain a 20mL, 10g / 100mL stearic acid ethanol solution. Examples 1-3

[0029] Examples 1-3 each provide an anti-aging insulating coating.

[0030] The difference between the above embodiments is that the stearic acid-modified talc used in the anti-aging insulating coating is derived from preparation examples 1-3.

[0031] The preparation method of the anti-aging insulating coating provided in Examples 1-3 includes the following steps: (1) Mix 36.5g of polydimethylsiloxane (a mixture of polydimethylsiloxane with a viscosity of 1500cp and polydimethylsiloxane with a viscosity of 20000cp in a weight ratio of 1:3), 17g of aluminum hydroxide, 12g of tricresyl phosphate and 6g of silica evenly to form a premix; (2) Add 4.5g of methyl tributanone oxime silane, 1.8g of vinyl tributanone oxime silane and 0.4g of dibutyltin dilaurate to the premix, stir evenly to form an intermediate product; (3) Add 3g of composite anti-aging agent, 43g of diluent, 0.25g of 3-aminopropyltriethoxysilane, 0.45g of propyltrimethoxysilane and 0.4g of aminoethylaminopropyltrimethoxysilane to the intermediate product, mix thoroughly and filter to remove impurities to obtain anti-aging insulating coating. The composite anti-aging agent consists of hindered amine light stabilizer, inositol hexaphosphate, and stearic acid-modified talc in a weight ratio of 1:0.4:2.5. Examples 4-5

[0032] Examples 4-5 each provide an anti-aging insulating coating.

[0033] The difference between the above embodiments and Embodiment 1 is that: In Example 4, the polydimethylsiloxane is a mixture of polydimethylsiloxane with a viscosity of 1500cp and polydimethylsiloxane with a viscosity of 20000cp in a weight ratio of 1:2. In Example 5, the polydimethylsiloxane is a mixture of polydimethylsiloxane with a viscosity of 1500 cp and polydimethylsiloxane with a viscosity of 20000 cp in a weight ratio of 1:4. Examples 6-11

[0034] Examples 6-11 each provide an anti-aging insulating coating.

[0035] The difference between the above embodiments and Embodiment 1 is that the proportions of each component in the composite anti-aging agent are shown in Table 1 below.

[0036] Table 1. Proportions of each component in the composite anti-aging agent of Examples 1 and 6-11 Comparative Example 1

[0037] Comparative Example 1 provides an anti-aging insulating coating.

[0038] The difference between the above comparative example and Example 1 is that only polydimethylsiloxane with a viscosity of 1500cp was used. Comparative Example 2

[0039] Comparative Example 2 provides an anti-aging insulating coating.

[0040] The difference between the above comparative example and Example 1 is that only polydimethylsiloxane with a viscosity of 20000cp was used. Comparative Example 3

[0041] Comparative Example 3 provides an anti-aging insulating coating.

[0042] The difference between the above comparative example and Example 1 is that the composite anti-aging agent is a hindered amine light stabilizer and stearic acid modified talc powder in a weight ratio of 1:2.9. Comparative Example 4

[0043] Comparative Example 4 provides an anti-aging insulating coating.

[0044] The difference between the above comparative example and Example 1 is that the composite anti-aging agent is a hindered amine light stabilizer and inositol hexaphosphate in a weight ratio of 1:2.9. Comparative Example 5

[0045] Comparative Example 5 provides an anti-aging insulating coating.

[0046] The difference between the above comparative example and Example 1 is that stearic acid modified talc is replaced with talc. Performance testing experiment

[0047] The anti-aging insulating coatings obtained in Examples 1-11 and Comparative Examples 1-5 were subjected to various performance tests, and the results are shown in Table 2 below.

[0048] (1) Long-term insulation under extreme conditions: The coating was sprayed according to the standard process and cured at 60℃ for 24h to obtain a coating film with a thickness of 200±20μm; the coating film was placed under the following temperature and humidity cycling conditions: 40℃, 95%RH, 12h→25℃, 60%RH, 12h, for a total of 50 cycles; after the 20th, 30th, 40th and 50th cycles, a DC voltage of 1000V was applied to the coating film and the volume resistivity of the coating film was measured; the volume resistivity was measured in accordance with GB / T 1410-2006.

[0049] (2) Aging resistance: The coating was sprayed according to the standard process and cured at 60℃ for 24h to obtain a coating film with a thickness of 200±20μm; the coating film was placed in a constant temperature and humidity UV aging test chamber and aged at 340nm, 40℃, and 95%RH for 1000h, and then the tensile strength retention rate of the coating film compared with that before aging was detected.

[0050] Table 2 Performance test results of anti-aging insulating coatings in Examples 1-11 and Comparative Examples 1-5

[0051] According to the test results in Table 2, the volume resistivity of the anti-aging insulating coating film obtained in Examples 1-11 was 4.2 × 10⁻⁶ after 50 cycles of alternating temperature and humidity. 14 ~5.1×10 14 The tensile strength retention rate after 1000 hours of constant temperature and humidity UV aging was 85.3-95.5% (Ω·cm); while the volume resistivity of the anti-aging insulating coatings obtained in Comparative Examples 1-5 was only 1.5 × 10⁻⁶ after 50 temperature and humidity cycles. 13 ~2.5×10 14 The tensile strength retention rate after 1000 hours of constant temperature and humidity UV aging is only 64.2-76.8% (Ω·cm). Therefore, this application uses a mixture of polydimethylsiloxane with a viscosity of 1000-2000cp and polydimethylsiloxane with a viscosity of 18000-22000cp in a weight ratio of 1:(2-4) as polydimethylsiloxane, and hindered amine light stabilizer, inositol hexaphosphate and stearic acid modified talc in a weight ratio of 1:(0.2-0.8):(1.5-3) as composite anti-aging agent. This can obtain an anti-aging insulating coating with good UV resistance, damp heat aging resistance and long-term insulation stability. When used for power facility protection, it can effectively reduce equipment maintenance costs and ensure the safe and stable operation of the power system.

[0052] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. An anti-aging insulating coating, characterized in that, The product comprises the following components in parts by weight: 28-40 parts polydimethylsiloxane, 15-18 parts aluminum hydroxide, 10-15 parts flame retardant, 5-8 parts silica, 2-4 parts composite anti-aging agent, 3-6 parts methyl tributanone oxime silane, 1.0-2.5 parts vinyl tributanone oxime silane, 0.1-0.4 parts 3-aminopropyltriethoxysilane, 0.3-0.6 parts propyltrimethoxysilane, 0.3-0.5 parts aminoethylaminopropyltrimethoxysilane, 0.2-0.6 parts dibutyltin dilaurate, and 40-46 parts diluent. The polydimethylsiloxane is a mixture of polydimethylsiloxane with a viscosity of 1000-2000cp and polydimethylsiloxane with a viscosity of 18000-22000cp in a weight ratio of 1:(2-4); The composite anti-aging agent is a hindered amine light stabilizer, inositol hexaphosphate, and stearic acid-modified talc in a weight ratio of 1:(0.2-0.8):(1.5-3).

2. The anti-aging insulating coating according to claim 1, characterized in that, The polydimethylsiloxane is a mixture of polydimethylsiloxane with a viscosity of 1500cp and polydimethylsiloxane with a viscosity of 20000cp in a weight ratio of 1:

3.

3. The anti-aging insulating coating according to claim 1, characterized in that, The weight ratio of the hindered amine light stabilizer, inositol hexaphosphate, and stearic acid modified talc is 1:(0.4-0.6):(2-2.5).

4. The anti-aging insulating coating according to claim 1, characterized in that, The weight ratio of the hindered amine light stabilizer, inositol hexaphosphate, and stearic acid-modified talc is 1:0.4:2.

5.

5. The anti-aging insulating coating according to any one of claims 1-4, characterized in that, The preparation method of the stearic acid modified talc powder includes the following steps: adding 8-15g / 100mL stearic acid ethanol solution to talc powder under stirring, then stirring at 80-90℃ for 30-40min, drying and sieving to obtain modified talc powder; the weight ratio of talc powder to stearic acid is 100:(1-2).

6. The anti-aging insulating coating according to claim 1, characterized in that, The diluent is an alcohol ether solvent.

7. A method for preparing an anti-aging insulating coating as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Mix polydimethylsiloxane, aluminum hydroxide, flame retardant and silica evenly to form a premix; (2) Add methyl tributanone oxime silane, vinyl tributanone oxime silane and dibutyltin dilaurate to the premix, stir evenly to form an intermediate product; (3) Add composite anti-aging agent, diluent, 3-aminopropyltriethoxysilane, propyltrimethoxysilane and aminoethylaminopropyltrimethoxysilane to the intermediate product, mix thoroughly and filter to remove impurities to obtain anti-aging insulating coating.

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