Two-component insulating self-foaming agent and preparation method thereof

Abstract

The application relates to the technical field of coatings, and particularly discloses a two-component insulating self-spraying agent and a preparation method thereof. The two-component insulating self-spraying agent provided by the application comprises an A component and a B component; the A component specifically comprises the following components in parts by weight: 70-100 parts of polydimethylsiloxane, 30-40 parts of aluminum hydroxide, 10-30 parts of fumed silica, 20-40 parts of a diluent, 5-10 parts of a crosslinking agent, 5-10 parts of a coupling agent and 1-9 parts of a modified additive; the modified additive is prepared from hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, dihydric alcohol and a catalyst in a weight ratio of 40-60:10-20:1-9:0.2-0.6; and the B component is a tin catalyst. The insulating self-spraying agent prepared by using the above technical scheme has a short surface dry curing time and good hydrophobicity, corrosion resistance, pollution flashover resistance and excellent weather resistance.

Description

Technical Field

[0001] This application relates to the technical field of coatings, specifically to a two-component insulating self-spraying agent and its preparation method. Background Technology

[0002] The surface of external insulation materials in electrical equipment is prone to accumulating dirt, causing "flashover" power outages. To reduce or avoid these outages, applying insulating coatings to the surface of the external insulation materials is an effective solution. These coatings possess strong water-repellent and insulating properties, maintaining the original structural integrity of the electrical equipment and providing protection and safeguards. This extends the equipment's lifespan, reduces the likelihood of flashover, and decreases the frequency of maintenance and corrosion repair for the external insulation materials.

[0003] Traditional insulating coatings (such as RTV silicone rubber) require specialized equipment for application and have long curing times (>12 hours), making them unsuitable for emergency maintenance of power equipment. Furthermore, single-component self-spraying insulating coatings suffer from poor adhesion, easy peeling, insufficient UV resistance, and are prone to chalking after long-term outdoor use. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a two-component insulating spray and its preparation method.

[0005] On the one hand, this application provides a two-component insulating spray, comprising component A and component B in a weight ratio of 190-194:1-5;

[0006] The A component specifically includes the following components in parts by weight: 70-100 parts of polydimethylsiloxane, 30-40 parts of aluminum hydroxide, 10-30 parts of fumed silica, 20-40 parts of diluent, 5-10 parts of crosslinking agent, 5-10 parts of coupling agent, and 1-9 parts of modifying agent.

[0007] The modified additive is prepared from hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, diol and catalyst in a weight ratio of 40-60:10-20:1-9:0.2-0.6.

[0008] Component B is a tin-based catalyst.

[0009] This application employs a modified additive prepared from hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, diol, and catalyst. Component A is prepared by combining polydimethylsiloxane, aluminum hydroxide, fumed silica, diluent, crosslinking agent, and coupling agent in specific weight ratios. Component B is prepared using a tin-based catalyst. This technical solution combines the weather resistance of organosilicon materials, the hydrophobicity of fluorides, and the insulating properties of inorganic fillers. Through scientific formulation and catalytic system optimization, the prepared insulating self-spraying agent exhibits a short surface drying time and possesses good hydrophobicity, corrosion resistance, flashover resistance, and excellent weather resistance, achieving a balance between rapid curing and superior overall performance.

[0010] In component A, polydimethylsiloxane serves as the matrix resin, providing the main chain structure and exhibiting excellent weather resistance and electrical insulation. Aluminum hydroxide, as an inorganic compound, can decompose and absorb heat, releasing water vapor, inhibiting combustion, and improving the product's flame retardant effect. Fumed silica, as a nano-reinforcing filler, enhances mechanical properties. The crosslinking agent promotes the condensation of the raw material system, forming a three-dimensional network structure, thereby increasing curing speed and hardness. The coupling agent improves the interfacial bonding between the inorganic filler and the organic phase, preventing phase separation. The diluent adjusts the spray viscosity, ensuring uniform atomization and improving the curing effect.

[0011] In the modified additives, by introducing fluoroalkylsilanes and diols into the main chain of hydrogen-terminated polydimethylsiloxane, a silane-hydrogen reaction is achieved, giving the material low surface energy and improved hydrophobicity, while maintaining the flexibility of organosilicon. Furthermore, the introduction of fluorine significantly enhances corrosion resistance (resistance to acids, alkalis, and salt spray) and flashover resistance (reducing surface charge accumulation). Diols can act as chain extenders to adjust the flexibility of molecular chains, improve film formation after spraying, and prevent cracking.

[0012] Using a tin-based catalyst as component B, the de-alcoholization reaction between silanol groups and crosslinking agents is efficiently promoted, significantly shortening surface drying and complete drying times, while further improving the overall performance of the insulating spray. It also works synergistically with other catalysts in component A to avoid reaction lag caused by steric hindrance of fluoroalkyl groups.

[0013] Preferably, component A specifically includes the following components in parts by weight: 80-90 parts of polydimethylsiloxane, 32-38 parts of aluminum hydroxide, 15-25 parts of fumed silica, 25-35 parts of diluent, 7-9 parts of crosslinking agent, 6-9 parts of coupling agent, and 3-7 parts of modifying agent.

[0014] Preferably, the modifying agent is prepared from a mixture of hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, diol, and catalyst in a weight ratio of 45-55:12-18:3-7:0.3-0.5.

[0015] Preferably, the modified additive is prepared by: mixing hydrogen-terminated polydimethylsiloxane and ethanol at a weight ratio of 1:3-5, removing oxygen; adding molecular sieve, stirring to dehydrate, and filtering for later use;

[0016] The dehydrated reaction system was heated to 35-60℃, and fluoroalkylsilane and diol were added dropwise; then the catalyst was added, and the reaction was stirred under nitrogen for 8-14 hours.

[0017] After the reaction is complete, the temperature is lowered to 25°C, activated carbon is added to adsorb the residual catalyst, and the mixture is filtered. The solvent is removed by rotary evaporation to obtain a transparent viscous liquid product, which is the modified additive.

[0018] Preferably, in the modifying agent, the fluoroalkyl silane is selected from one or more of tridecafluorooctyltrimethoxysilane and heptadecafluorodecyltriethoxysilane;

[0019] The diol is selected from one or more of ethylene glycol and polyethylene glycol with a molecular weight of 200-800;

[0020] The catalyst is selected from one or more of dibutyltin dilaurate and platinum catalyst H2PtCl6.

[0021] Preferably, the diluent is selected from one or more of toluene, n-heptane, n-hexane, and petroleum ether.

[0022] Preferably, the diluent is a mixture of toluene and n-hexane in a weight ratio of 7-11:1-3.

[0023] In one specific implementation, the weight ratio of toluene to n-hexane in the diluent can be 7:1, 7:2, 7:3, 9:1, 9:2, 9:3, 11:1, 11:2, or 11:3.

[0024] Experimental analysis shows that the toluene and n-hexane mixture in the above weight ratio is beneficial to improving the hydrophobicity and aging resistance of the spray paint; on the other hand, it can promote the uniform distribution of materials in the system, thereby further improving the performance of the generated coating.

[0025] Preferably, the specific surface area of ​​the fumed silica is 125-175 m². 2 / g; the crosslinking agent is a deoxime crosslinking agent; the coupling agent is an aminosilane coupling agent; the catalyst is a condensation-type tin-based silicone rubber catalyst.

[0026] Preferably, the crosslinking agent is selected from one or more of vinyltributylone oxime silane and methyltributylone oxime silane; the coupling agent is selected from one or more of methyltrimethoxysilane and γ-aminopropyltriethoxysilane.

[0027] Preferably, the tin catalyst is selected from one or more of dibutyltin dilaurate, dibutyltin oxide, and dibutyltin diacetate.

[0028] On the other hand, this application provides a method for preparing the above-mentioned two-component insulating spray, specifically including the following steps in sequence:

[0029] Weigh out the corresponding weights of each raw material component;

[0030] Polydimethylsiloxane, aluminum hydroxide, fumed silica, and modifying agents were vacuumed at 120-150℃ and mixed evenly. After cooling to room temperature, a diluent was added and mixed evenly. The mixture was then sand-milled to a fineness ≤20μm. Then, a crosslinking agent, coupling agent, and catalyst were added to the system and mixed evenly. The mixture was then filtered and packaged to obtain component A.

[0031] Dibutyltin dilaurate was packaged separately as component B.

[0032] In summary, the technical solution of this application has the following effects:

[0033] This application uses a modified additive prepared from hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, diol, and catalyst. Component A is prepared by combining polydimethylsiloxane, aluminum hydroxide, fumed silica, diluent, crosslinking agent, and coupling agent in specific weight ratios. Component B is prepared using dibutyltin dilaurate. Through scientific formulation and catalytic system optimization, this technical solution produces an insulating self-spraying agent with a short surface drying time, good hydrophobicity, corrosion resistance, flashover resistance, and excellent weather resistance, achieving a balance between rapid curing and superior overall performance. Detailed Implementation

[0034] The present application will be further described in detail below with reference to embodiments, comparative examples and performance test results. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0035] The hydrogen-terminated polydimethylsiloxane (CAS: 70900-21-9; product name XJY-707) used in this application was purchased from Jiangxi Xinjiayi New Materials Co., Ltd.; the specific surface area of ​​fumed silica is 125-175 m². 2 / g, purchased from Degussa; all other raw materials were available commercially.

[0036] Example

[0037] Examples 1-5

[0038] Examples 1-5 provide a two-component insulating spray and its preparation method, respectively.

[0039] The difference in the above embodiments is that the amount of each raw material in component A is different, as shown in Table 1.

[0040] The preparation method of the two-component insulating spray in the above embodiments is as follows:

[0041] The preparation method of the modified additive is as follows: Hydrogen-terminated polydimethylsiloxane and ethanol are mixed evenly at a weight ratio of 1:4, and nitrogen gas is bubbled for 30 minutes to remove oxygen; 5 wt% of molecular sieve is added to the raw material system, and the mixture is stirred and dehydrated for 120 minutes, then filtered for later use.

[0042] The dehydrated reaction system was heated to 45°C, and (heptadecyltriethoxysilane fluoroalkylsilane) and diol (polyethylene glycol with a molecular weight of 400) were added dropwise. Then, platinum catalyst H2PtCl6 was added, and the reaction was stirred for 12 hours under nitrogen atmosphere.

[0043] After the reaction was completed, the temperature was lowered to 25°C, and 1 wt% activated carbon was added to the reaction system to adsorb the residual catalyst. The mixture was then filtered. The solvent was removed by rotary evaporation at 50°C and -0.09 MPa to obtain a transparent viscous liquid product, which is the modified additive.

[0044] The weight ratio of the hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, diol, and platinum catalyst H2PtCl6 is 50g:15g:5g:0.4g.

[0045] The preparation method of component A is as follows: Weigh the corresponding weights of each raw material component according to Table 1; combine polydimethylsiloxane, aluminum hydroxide, and fumed silica (with a specific surface area of ​​150 m²). 2 / g), modified additives, vacuumed at 140℃ and mixed evenly; after cooling to room temperature, add diluent (the diluent is composed of toluene and n-hexane in a weight ratio of 9:2) and mix evenly; grind to a fineness ≤20μm; then add crosslinking agent methyltributanone oxime silane and coupling agent methyltrimethoxysilane to the system and mix evenly, filter and package to obtain component A.

[0046] Dibutyltin dilaurate was packaged separately as component B.

[0047] When using, mix component A and component B evenly at a weight ratio of 191:3.

[0048] Table 1. Amounts of each raw material in component A in Examples 1-5 and Comparative Examples 1-2

[0049]

[0050] Examples 6-9

[0051] Examples 6-9 respectively provide a two-component insulating spray and its preparation method.

[0052] The difference between the above embodiments and Embodiment 1 is that the preparation methods of the modified additives are different, as shown below.

[0053] In Example 6, the modified additive was prepared from a hydrogen-terminated polydimethylsiloxane, a fluoroalkylsilane, polyethylene glycol with a molecular weight of 400, and a catalyst in a weight ratio of 40g:20g:9g:0.2g.

[0054] In Example 7, the modified additive was prepared from a hydrogen-terminated polydimethylsiloxane, a fluoroalkylsilane, polyethylene glycol with a molecular weight of 1000, and a catalyst in a weight ratio of 50g:15g:5g:0.4g.

[0055] In Example 8, the modified additive was prepared from a hydrogen-terminated polydimethylsiloxane, a fluoroalkylsilane, polyethylene glycol with a molecular weight of 400, and a catalyst in a weight ratio of 45g:18g:7g:0.3g.

[0056] In Example 9, the modifying agent was prepared from a hydrogen-terminated polydimethylsiloxane, a fluoroalkylsilane, polyethylene glycol with a molecular weight of 400, and a catalyst in a weight ratio of 55g:12g:3g:0.5g.

[0057] All other process parameters in the above embodiments are the same as those in Embodiment 1.

[0058] Examples 10-13

[0059] Examples 10-13 respectively provide a two-component insulating spray and its preparation method.

[0060] The difference between the above embodiments and Embodiment 1 is that the type of diluent is different, as shown below.

[0061] Example 10: The diluent is composed of toluene and dichloromethane in a weight ratio of 9:2.

[0062] Example 11: The diluent is composed of a mixture of toluene and n-hexane in a weight ratio of 2:9.

[0063] Example 12: The diluent is composed of a mixture of toluene and n-hexane in a weight ratio of 7:3.

[0064] Example 13: The diluent is composed of a mixture of toluene and n-hexane in a weight ratio of 11:1.

[0065] All other process parameters in the above embodiments are the same as those in Embodiment 1.

[0066] Comparative Example

[0067] Comparative Examples 1-2

[0068] Comparative Examples 1 and 2 respectively provide a two-component insulating spray and its preparation method.

[0069] The difference between the above comparative example and Example 1 is that the amount of each raw material in component A is different, as shown in Table 1.

[0070] All other process parameters in the above comparative examples are the same as those in Example 1.

[0071] Comparative Example 3

[0072] Comparative Example 3 provides an insulating self-spraying agent and its preparation method.

[0073] The difference between the above comparative example and Example 1 is that it does not contain component B, and 3g of dibutyltin dilaurate of component B is added to component A to form a system.

[0074] The preparation method of the insulating spray is as follows: weigh out the corresponding weights of each raw material component; mix 85g of polydimethylsiloxane, 35g of aluminum hydroxide, and 20g of fumed silica (with a specific surface area of ​​150m²). 2 5g of modified additives were vacuumed at 140℃ and mixed evenly. After cooling to room temperature, 30g of diluent (composed of toluene and n-hexane in a weight ratio of 9:2) was added and mixed evenly. The mixture was then sand-milled to a fineness ≤30μm. Then, 8g of crosslinking agent methyltributyl ketone oxime silane, 8g of coupling agent methyltrimethoxysilane and 3g of dibutyltin dilaurate were added to the system and mixed evenly. The mixture was then filtered and packaged to obtain the insulating self-spraying agent.

[0075] Comparative Example 4-5

[0076] Comparative Examples 4 and 5 respectively provide a two-component insulating spray and its preparation method.

[0077] The differences between the above comparative example and Example 1 are as follows.

[0078] In Comparative Example 4, the modifying agent was prepared from a mixture of hydrogen-terminated polydimethylsiloxane, γ-aminopropyltriethoxysilane, polyethylene glycol with a molecular weight of 400, and platinum catalyst H2PtCl6 in a weight ratio of 50g:15g:5g:0.4g.

[0079] In Comparative Example 5, the modifying agent was prepared from a mixture of hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, polyethylene glycol with a molecular weight of 400, and platinum catalyst H2PtCl6 in a weight ratio of 30g:25g:13g:0.3g.

[0080] All other process parameters in the above comparative examples are the same as those in Example 1.

[0081] Performance testing

[0082] The coatings prepared in the examples and comparative examples were uniformly sprayed onto a high-temperature resistant epoxy resin board with dimensions of 60mm×40mm×2mm (length×width×thickness) at a distance of 25cm from the target to form a test sample with a coating thickness of 60μm.

[0083] (1) Surface drying time: The test was conducted according to the method in GB / T 1728-2020 Test of drying time of paint film and putty film (the surface drying time was recorded every 5 minutes and the actual drying time was recorded every half hour).

[0084] (2) Contact angle: The hydrophobicity is evaluated by testing according to the method in IEC / TS 62073:2016.

[0085] (3) Dielectric strength: Tested according to GB / T 1408.1-2016 Test method for electrical strength of solid insulating materials.

[0086] (4) Resistance to acid and alkali corrosion: After immersing the sample in 1 mol / L hydrochloric acid solution and 1 mol / L sodium hydroxide solution for 24 hours, take out the sample, air dry it, and then observe the surface condition of the coating.

[0087] (5) Weather resistance: The sample was placed at a temperature of 160℃ and a humidity of 50% for 480h; then the sample was taken out, cooled to room temperature, and its contact angle and dielectric strength were tested.

[0088] Test results are shown in Table 2.

[0089] Table 2 Performance test results of the insulating spray in the examples and comparative examples

[0090]

[0091] As can be seen from the test results in the table above, the insulating self-spraying agent prepared using the technical solution provided in this application has a short surface drying curing time and good water repellency, corrosion resistance, flashover resistance and excellent weather resistance.

[0092] In Comparative Example 1, the amounts of raw materials in Component A were mismatched. In Comparative Example 2, no modifying agent was added. In Comparative Example 3, 3g of dibutyltin dilaurate from Component B was added to Component A to form a system. In Comparative Example 4, the modifying agent was prepared from hydrogen-terminated polydimethylsiloxane, γ-aminopropyltriethoxysilane, polyethylene glycol with a molecular weight of 400, and platinum catalyst H2PtCl6 in a weight ratio of 50g:15g:5g:0.4g. In Comparative Example 5, the modifying agent was prepared from hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, polyethylene glycol with a molecular weight of 400, and platinum catalyst H2PtCl6 in a weight ratio of 30g:25g:13g:0.3g. The overall performance of the prepared insulating spray was poor.

[0093] In contrast, this application uses a modified additive prepared from hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, and diol in a weight ratio of 40-60:10-20:1-9:0.2-0.6. Component A is prepared by combining polydimethylsiloxane, aluminum hydroxide, fumed silica, diluent, crosslinking agent, coupling agent, and catalyst in a specific weight ratio. Component B is prepared using dibutyltin dilaurate. The resulting insulating spray has a short surface drying time and exhibits good hydrophobicity, corrosion resistance, flashover resistance, and excellent weather resistance.

[0094] By comparing the test results of Examples 1 and 6-9, this application selects a modified additive prepared from a modified additive in a weight ratio of 45-55:12-18:3-7:0.3-0.5 of terminal hydrogen polydimethylsiloxane, fluoroalkylsilane, polyethylene glycol with a molecular weight of 200-800, and a catalyst, which can further improve the performance of the insulating spray.

[0095] By comparing the test results of Examples 1, 10-13, this application selects toluene and n-hexane mixed in a weight ratio of 7-11:1-3 as a diluent, which can further improve the performance of the insulating spray.

[0096] 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. A two-component insulating self-foaming agent, characterized in that, Includes component A and component B with a weight ratio of 190-194:1-5; The A component specifically includes the following components in parts by weight: 70-100 parts of polydimethylsiloxane, 30-40 parts of aluminum hydroxide, 10-30 parts of fumed silica, 20-40 parts of diluent, 5-10 parts of crosslinking agent, 5-10 parts of coupling agent, and 1-9 parts of modifying agent. The modifying agent is prepared from a mixture of hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, diol, and catalyst in a weight ratio of 40-60:10-20:1-9:0.2-0.6; the catalyst is selected from one or more of dibutyltin dilaurate and platinum catalyst H2PtCl6. Component B is a tin-based catalyst.

2. The two-component insulating self-spraying agent according to claim 1, characterized in that, Component A specifically includes the following components by weight: 80-90 parts of polydimethylsiloxane, 32-38 parts of aluminum hydroxide, 15-25 parts of fumed silica, 25-35 parts of diluent, 7-9 parts of crosslinking agent, 6-9 parts of coupling agent, and 3-7 parts of modifying agent.

3. The two-component insulating spray according to claim 1, characterized in that, The modified additive is prepared from hydrogen-terminated polydimethylsiloxane, fluoroalkylsilane, diol and catalyst in a weight ratio of 45-55:12-18:3-7:0.3-0.

5.

4. The two-component insulating self-spraying agent according to claim 1, characterized in that, The preparation method of the modified additive is as follows: hydrogen-terminated polydimethylsiloxane and ethanol are mixed evenly at a weight ratio of 1:3-5, and oxygen is removed; molecular sieves are added, stirred and dehydrated, and filtered for later use. The dehydrated reaction system was heated to 35-60℃, and fluoroalkylsilane and diol were added dropwise; then the catalyst was added, and the reaction was stirred under nitrogen for 8-14 hours. After the reaction is complete, the temperature is lowered to 25°C, activated carbon is added to adsorb the residual catalyst, and the mixture is filtered. The solvent is removed by rotary evaporation to obtain a transparent viscous liquid product, which is the modified additive.

5. The two-component insulating self-spraying agent according to claim 1, characterized in that, In the modified additive, the fluoroalkyl silane is selected from one or more of tridecafluorooctyltrimethoxysilane and heptadecafluorodecyltriethoxysilane; The diol is selected from one or more of ethylene glycol and polyethylene glycol with a molecular weight of 200-800.

6. The two-component insulating self-spraying agent according to claim 1, characterized in that, The diluent is selected from one or more of toluene, n-heptane, n-hexane, and petroleum ether.

7. The two-component insulating self-spraying agent according to claim 6, characterized in that, The diluent is a mixture of toluene and n-hexane in a weight ratio of 7-11:1-3.

8. The two-component insulating self-spraying agent according to claim 1, characterized in that, The specific surface area of ​​the fumed silica is 125-175 m². 2 / g; the crosslinking agent is a deoxime crosslinking agent, and the crosslinking agent is selected from one or more of vinyltributylone oxime silane and methyltributylone oxime silane; the coupling agent is an aminosilane coupling agent, and the coupling agent is selected from one or more of methyltrimethoxysilane and γ-aminopropyltriethoxysilane.

9. The two-component insulating self-spraying agent according to claim 1, characterized in that, The tin catalyst is selected from one or more of dibutyltin dilaurate, dibutyltin oxide, and dibutyltin diacetate.

10. The method for preparing the two-component insulating spray according to any one of claims 1-9, characterized in that, Specifically, the following steps are performed sequentially: Weigh out the corresponding weights of each raw material component; Polydimethylsiloxane, aluminum hydroxide, fumed silica, and modifying agents are vacuumed at 120-150℃ and mixed evenly; after cooling to room temperature, a diluent is added and mixed evenly; the mixture is then milled to a fineness ≤20μm; then a crosslinking agent and coupling agent are added to the system and mixed evenly, filtered, and packaged to obtain component A; Tin-based catalysts are packaged separately as component B.

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