An organic-inorganic composite filling paste for electric power and a preparation method and application thereof

Abstract

The application discloses an organic-inorganic composite filling paste for electric power and a preparation method and application thereof. The organic-inorganic composite filling paste for electric power comprises an inorganic matrix, an organic composite additive and water, wherein the inorganic matrix is dolomite, the organic composite additive is composed of an interface modifier and a network building agent, the interface modifier is at least one of sodium lignosulfonate and calcium lignosulfonate, and the network building agent is hydroxypropyl methyl cellulose; and the mass percentage of the water in the organic-inorganic composite filling paste for electric power is 15%-25%. The organic-inorganic composite filling paste for electric power has the advantages of low thermal resistance, non-combustibility, good dispersibility, high long-term storage stability and good construction adaptability.

Description

Technical Field

[0001] This invention relates to the field of electric power, and more particularly to an organic-inorganic composite filler paste for electric power, its preparation method, and its application. Background Technology

[0002] With the continuous development of power systems, cables, as an important carrier of power transmission, are receiving increasing attention for their safety and transmission efficiency. Cable filling materials, as a key component of the cable structure, not only need to possess excellent insulation properties but also need to meet various functional requirements such as heat dissipation and fire resistance.

[0003] Currently, cable filler materials are mainly divided into two categories: organic and inorganic. Organic fillers are widely used due to their good plasticity and bonding properties, but their inherent flammability and the release of toxic fumes at high temperatures pose potential risks to the safe operation of cable systems. For example, existing technology discloses a low-filling, high-thermal-conductivity organic-inorganic composite. This composite contains organic components as a heat-dissipating matrix and flake-like and non-flake-like inorganic materials as thermally conductive fillers. Through the compounding of various morphologies of inorganic thermally conductive fillers, a thermally conductive network is formed in the organic heat-dissipating matrix, exhibiting high thermal conductivity. However, this solution has a high organic content, which still poses safety hazards at high temperatures. Inorganic fillers have inherent flame-retardant properties and have broad application prospects in the field of cable fire protection. For example, existing technology discloses a magnesium oxysulfate foamed cement external wall insulation board. This material has fire-resistant, high-temperature resistant properties, as well as high strength and low density. However, pure inorganic materials often suffer from poor construction compatibility, limiting their application in the field of cable fillers. Meanwhile, in high-solids-content systems, rigid inorganic particles are prone to agglomeration and sedimentation, affecting the homogeneity and long-term storage stability of the paste. Furthermore, existing filler materials generally have high thermal resistance per unit area, impacting cable heat dissipation efficiency and leading to reduced current carrying capacity. Although existing technologies have explored the use of sodium lignosulfonate or hydroxypropyl methylcellulose (HPMC) alone for inorganic filler modification, these methods have not effectively addressed the core issue of balancing dispersibility and stability in high-solids-content systems. Additionally, some technologies utilize high-temperature sintering to prepare cable filler materials, which, while possessing certain functional properties, suffer from poor repairability during construction and are ill-suited to complex on-site conditions.

[0004] Therefore, developing a cable filler material that combines good heat dissipation, fire resistance, and construction adaptability is of great significance for improving the safety and transmission efficiency (cable current carrying capacity) of cable systems. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an organic-inorganic composite filler paste for power applications, its preparation method and application, thereby solving the technical problems of high flammability of organic materials, poor construction adaptability of inorganic materials, high thermal resistance of existing cable filler materials, and poor dispersion stability of inorganic particles in high solid content systems.

[0006] In a first aspect, the present invention provides an organic-inorganic composite filler paste for power applications, comprising: an inorganic matrix, an organic composite additive, and water; wherein the inorganic matrix is ​​dolomite, the organic composite additive is composed of an interface modifier and a network building agent, the interface modifier is at least one of sodium lignosulfonate and calcium lignosulfonate, and the network building agent is hydroxypropyl methylcellulose (HPMC); in the organic-inorganic composite filler paste for power applications, the mass percentage of water is 15%-25%, including but not limited to 15%, 17%, 20%, 22%, 25%, etc., preferably 17%-22%.

[0007] In this invention, dolomite (CaMg(CO3)2) is chosen as the inorganic matrix because its thermal decomposition behavior has significant synergistic advantages. First, it undergoes thermal decomposition in the temperature range of 500-800℃, which precisely matches the fire development process. Second, the decomposition products are a mixture of calcium oxide (CaO) and magnesium oxide (MgO), and this composite system is easy to form a dense, thermally stable ceramic-like thermal insulation skeleton at high temperatures.

[0008] In this invention, the above-mentioned interface modifier is selected to provide efficient dispersion for water-based inorganic particles of dolomite with high solids content. Compared with other dispersants, the above-mentioned interface modifier has unique advantages. Its unique sulfonic acid group and amphiphilic molecular structure can produce a dual stabilizing effect of steric hindrance and electrostatic repulsion, which is a necessary condition for achieving long-term stable dispersion of the high solids content system of this invention.

[0009] In this invention, hydroxypropyl methylcellulose (HPMC) possesses unique amphiphilic properties, enabling it to form a three-dimensional network in water with hydrophobic association as the physical cross-linking points. This constructs a strong and reversible gel network, which on the one hand firmly locks in moisture, solving the problem of water seepage, and on the other hand, fixes the dispersed particles within it, giving the paste ideal non-curing properties. The above-mentioned network builder is selected to form a robust, solid-like three-dimensional network structure for high-solids-content water-based inorganic particulate dolomite pastes, giving the paste good yielding behavior and maintaining excellent stability under static or low-shear conditions, which is beneficial for its long-term storage stability.

[0010] Preferably, the interface modifier is sodium lignosulfonate.

[0011] Preferably, the molecular weight M of the interface modifier is... w The range is 5000-20000.

[0012] Preferably, the molecular weight M of the network builder is... w The range is 60,000-100,000.

[0013] In this invention, the organic composite additive in the organic-inorganic composite filler paste for power applications comprises 0.4%-4% by mass, including but not limited to 0.4%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, and 4%, preferably 1%-2%. When the mass proportion of the organic composite additive is too low, the resulting structural network is incomplete, and the paste will experience particle agglomeration and phase separation. When the mass proportion of the organic composite additive is too high, the excessively dense organic phase will not only block the heat conduction pathway but also affect its workability.

[0014] In this invention, the mass ratio of the interface modifier to the network building agent is 1:(0.02-0.5), including but not limited to 1:0.02, 1:0.05, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, etc., preferably 1:(0.05-0.3). When the mass ratio of the network building agent is too low, it is difficult to form a stable three-dimensional network, and the paste is prone to layering, bleeding, and deterioration of rheological properties; when the mass ratio of the network building agent is too high, the proportion of organic network structure is too large, resulting in an increase in the thermal resistance of the paste, making it impossible to meet the core performance requirements of heat dissipation and fire resistance.

[0015] In this invention, the inorganic matrix accounts for 60%-83% of the mass of the organic-inorganic composite filler paste for power applications, including but not limited to 60%, 65%, 70%, 75%, 80%, and 83%, which is a clearly high solids content system.

[0016] In this invention, the average particle size of the inorganic matrix is ​​10-500 μm, preferably 100-300 μm.

[0017] In this invention, the organic-inorganic composite filler paste for power applications also includes functional fillers. The function of the functional fillers is to fill the interfacial voids between dolomite particles and between them and the paste matrix, thereby constructing thermal conductivity pathways or enhancing fire resistance, precisely resolving the contradiction between "heat dissipation" and "fire prevention" in traditional materials, and achieving integrated active thermal management and passive fire prevention.

[0018] Preferably, the functional filler is at least one of boron nitride, alumina, and expanded graphite.

[0019] Preferably, the average particle size of the functional filler is 5-200 μm, more preferably 5-50 μm.

[0020] Preferably, in the organic-inorganic composite filler paste for power applications, the mass percentage of functional fillers is 0%-15%, including but not limited to 0%, 1%, 5%, 8%, 10%, 12%, and 15%, with 5%-15% being the most preferred. If functional fillers are added, if the mass percentage of functional fillers is less than 5%, the functional fillers cannot function well, and if the mass percentage of functional fillers is greater than 15%, it is not conducive to dispersion and the formation of a ceramic-like thermal insulation skeleton.

[0021] In this invention, the unit area thermal resistance of the organic-inorganic composite filler paste for power applications is ≤0.67 K·m. 2 / W.

[0022] In this invention, the residual mass percentage of the organic-inorganic composite filler paste for power applications is ≥50% at 1000℃.

[0023] In this invention, the organic-inorganic composite filler paste for power applications can increase the steady-state current carrying capacity of cables by 30%-50%.

[0024] Secondly, the present invention provides a method for preparing an organic-inorganic composite filler paste for power applications, comprising the following steps:

[0025] S1. Preparation of single solutions: Prepare network building agent solution and interface modifier solution;

[0026] S2. Preparation of organic composite additive solution: Mix the network building agent solution and the interface modifier solution evenly to obtain the organic composite additive solution;

[0027] S3. Mixing and molding: The inorganic matrix and the organic composite additive solution are mixed evenly to obtain a preliminary composite paste;

[0028] S4. Vacuum defoaming: Vacuum defoaming is performed on the preliminary composite paste to obtain an organic-inorganic composite filler paste for electrical applications.

[0029] In this invention, step S1, preparing the network building agent solution includes: dispersing the network building agent in a first water preheated to 80-90°C at a first stirring rate, then rapidly lowering the system temperature to room temperature, and then placing the mixture in a cold water bath at 2-10°C (preferably 3-5°C) and subjecting it to a first stirring treatment to obtain the network building agent solution.

[0030] This invention prevents the outermost layer of the network builder from hindering internal hydration by rapidly lowering the system temperature to room temperature.

[0031] Preferably, the mixture is mixed with a second water at 15-25°C (preferably 20-22°C) to rapidly lower the system temperature to room temperature.

[0032] More preferably, the total mass ratio of the first water and the second water is 50%-55% of the total water volume.

[0033] More preferably, the mass ratio of the first water to the second water is 1:(0.8-1.2).

[0034] Preferably, the first stirring rate is 800-1500 rpm.

[0035] Preferably, during the first stirring process, the stirring rate is 100-300 rpm and the stirring time is 0.3-1 h.

[0036] In this invention, step S1, preparing the interface modifier solution includes: dispersing the interface modifier in a third water, followed by a second stirring treatment to obtain the interface modifier solution.

[0037] Preferably, during the second stirring process, the temperature is room temperature, the stirring rate is 100-300 rpm, and the time is 30-60 min.

[0038] In this invention, step S2 includes: adding the network builder solution to the interface modifier solution at a second stirring rate, followed by a third stirring treatment to obtain an organic composite auxiliary solution.

[0039] Preferably, the network builder solution is added to the interface modifier solution in batches, with 2-5 additions and an interval of 5-10 minutes between each addition.

[0040] Preferably, the second stirring rate is 100-300 rpm.

[0041] Preferably, during the third stirring process, the temperature is room temperature, the stirring rate is 100-300 rpm, and the stirring time is 30-60 min.

[0042] In this invention, step S3 includes: adding an organic composite additive solution to an inorganic matrix at a third stirring rate, followed by a fourth stirring treatment to obtain a preliminary composite paste.

[0043] Preferably, the third stirring rate is 300-500 rpm.

[0044] Preferably, during the fourth stirring process, the stirring temperature is room temperature, the stirring speed is 300-500 rpm, and the stirring time is 0.2-2 h.

[0045] In this invention, step S3 includes: mixing the inorganic matrix, functional filler, and organic composite additive solution evenly to obtain a preliminary composite paste. If functional filler needs to be added, it can be added simultaneously with the inorganic matrix.

[0046] In this invention, step S3 further includes: mixing the preliminary composite paste and the functional filler, followed by a fifth stirring treatment. If functional filler needs to be added, it can also be added and stirred after the preliminary composite paste is formed.

[0047] Preferably, during the fifth stirring process, the temperature is room temperature, the stirring rate is 300-500 rpm, and the stirring time is 0.2-2 h.

[0048] In this invention, during step S4, the vacuum degassing process is carried out at room temperature, with a vacuum level of -0.095 MPa to -0.1 MPa, and a time of 0.5-1.5 h.

[0049] It should be noted that the room temperature in this invention is 20-25℃.

[0050] Thirdly, the present invention provides the application of the above-mentioned organic-inorganic composite filler paste for power applications in cable filling and fireproof sealing.

[0051] The organic-inorganic composite filler paste for power applications of this invention is used for filling the gaps between the conductors of power transmission cables, sealing cable trenches, or sealing cable joints, and can achieve integrated optimization of cable heat dissipation and passive fire protection.

[0052] Compared with the prior art, the beneficial effects of the present invention include:

[0053] This invention utilizes the inorganic nature of dolomite to endow the material with non-combustibility and high-temperature stability, fundamentally overcoming the flammability defects of organic fireproof putty. Through the synergistic effect of a unique interface modifier and network builder, this invention achieves efficient dispersion of inorganic particles and stable control of the macroscopic rheological properties of the paste, enabling the composite filler paste to simultaneously possess excellent rheological properties and long-term storage stability, solving the core problem of coexisting dispersibility and stability in high-solids content systems. Simultaneously, through the plasticizing and binding effects of organic components, the brittle cracking and construction compatibility issues of purely inorganic materials are avoided. The composite filler paste of this invention has a unit area thermal resistance as low as 0.53-0.67 K·m. 2 / W is significantly superior to traditional materials, effectively reducing conductor operating temperature and supporting a 30%-50% increase in steady-state current carrying capacity of cable systems. It also solves the problem of poor heat dissipation in cables caused by the high thermal resistance of traditional filler materials. Attached Figure Description

[0054] Figure 1 Thermogravimetric-infrared (FTIR-TG) three-dimensional spectrum of the composite filler paste prepared in Example 1 of this invention;

[0055] Figure 2 Thermogravimetric-differential thermogravimetric (TG-DTG) curve of the composite filler paste prepared in Example 1 of the present invention;

[0056] Figure 3 The Fourier transform infrared (FTIR) spectrum of the composite filler paste prepared in Example 1 of the present invention and its raw material components and physical mixture (PM) is shown in the figure.

[0057] Figure 4 The curve showing the complex viscosity of the composite filler paste prepared in Example 1 of this invention as a function of shear strain. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0059] Example 1

[0060] A method for preparing an organic-inorganic composite filler paste for power applications includes the following steps:

[0061] (1) Preparation of hydroxypropyl methylcellulose gel

[0062] Weigh 0.15 parts of hydroxypropyl methylcellulose (HPMC) powder and slowly and uniformly disperse it in 5 parts of deionized water preheated to 85°C while stirring at 1000 rpm, ensuring the powder does not clump during dispersion. Immediately afterwards, add 5 parts of low-temperature deionized water at 20-22°C to rapidly lower the system temperature to room temperature. Then, place the mixture in a 3-5°C cold water bath and stir continuously at 200 rpm for 30 minutes to obtain a completely transparent, homogeneous HPMC solution without visible particles, denoted as solution A. In this invention, the above low-temperature hydration process ensures that the hydroxypropyl methylcellulose is fully extended, forming a complete three-dimensional hydration network precursor.

[0063] (2) Preparation of sodium lignosulfonate solution

[0064] Dissolve 1.5 parts of sodium lignosulfonate powder in 9.35 parts of deionized water at 25°C. Stir the solution at 200 rpm for 30 minutes using a magnetic stirrer until a homogeneous solution is formed. This solution is denoted as solution B.

[0065] (3) Preparation of organic composite auxiliary solution

[0066] At room temperature, with a stirring speed of 200 rpm, the HPMC adhesive solution (solution A) obtained in step (1) was slowly poured into the sodium lignosulfonate solution (solution B) obtained in step (2) in three portions, with an interval of 8 minutes between each addition, to ensure that the HPMC adhesive solution and the sodium lignosulfonate solution were fully mixed. After the addition was completed, the mixture was stirred for another 30 minutes at a stirring speed of 200 rpm to ensure uniform mixing, resulting in an organic composite additive solution (solution C). The mass ratio of sodium lignosulfonate to HPMC was 1:0.1.

[0067] (4) Preparation of composite paste

[0068] At room temperature, 79 parts of dolomite powder (average particle size of 200 μm) were placed in a vacuum stirring container. While stirring continuously at 400 rpm, the organic composite additive solution (solution C) obtained in step (3) was slowly and evenly added to the dolomite powder to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 45 min until a paste with uniform texture, no obvious particle agglomeration, and consistent color was obtained.

[0069] (5) Vacuum defoaming

[0070] The composite paste obtained in step (4) above was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied and the mixture was processed for 45 minutes to eliminate air bubbles entrained during stirring, and the final product was obtained. The water content of the final product was 19.35 parts.

[0071] Example 2

[0072] A method for preparing an organic-inorganic composite filler paste for power applications includes the following steps:

[0073] (1) Preparation of hydroxypropyl methylcellulose gel

[0074] Weigh 0.15 parts of hydroxypropyl methylcellulose (HPMC) powder and slowly and evenly disperse it in 5 parts of deionized water preheated to 85°C while stirring at 1000 rpm, ensuring that the powder does not clump during the dispersion process. Then immediately add 5 parts of low-temperature deionized water at 20-22°C to rapidly lower the system temperature to room temperature. Then place the mixture in a 3-5°C cold water bath and stir continuously at 200 rpm for 30 minutes to obtain a completely transparent, homogeneous HPMC solution without visible particles, denoted as solution A.

[0075] (2) Preparation of sodium lignosulfonate solution

[0076] Dissolve 1.5 parts of sodium lignosulfonate powder in 9.35 parts of deionized water at 25°C. Stir the solution at 200 rpm for 30 minutes using a magnetic stirrer until a homogeneous solution is formed. This solution is denoted as solution B.

[0077] (3) Preparation of organic composite auxiliary solution

[0078] At room temperature, with a stirring speed of 200 rpm, the HPMC adhesive solution (solution A) obtained in step (1) was slowly poured into the sodium lignosulfonate solution (solution B) obtained in step (2) in three portions, with an interval of 8 minutes between each addition. After the addition was completed, the mixture was stirred for another 30 minutes at a stirring speed of 200 rpm to ensure uniform mixing, thus obtaining the organic composite additive solution (solution C). The mass ratio of sodium lignosulfonate to HPMC was 1:0.1.

[0079] (4) Preparation of composite paste

[0080] At room temperature, 74 parts of dolomite powder (average particle size of 200 μm) and 5 parts of alumina powder (average particle size of 10 μm) were mixed evenly and placed in a vacuum stirring container. Under continuous stirring at 400 rpm, the organic composite additive solution (solution C) obtained in step (3) was slowly and evenly added to the mixed powder to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 45 min until a paste with uniform texture, no obvious particle agglomeration, and consistent color was obtained.

[0081] (5) Vacuum defoaming

[0082] The composite paste obtained above was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied for 45 minutes to eliminate air bubbles entrained during stirring, and the final product was obtained. The water content of the final product was 19.35 parts.

[0083] Example 3

[0084] A method for preparing an organic-inorganic composite filler paste for power applications includes the following steps:

[0085] (1) Preparation of hydroxypropyl methylcellulose gel

[0086] Weigh 0.05 parts of hydroxypropyl methylcellulose (HPMC) powder and slowly and evenly disperse it in 5 parts of deionized water preheated to 85°C while stirring at 1000 rpm, ensuring that the powder does not clump during dispersion. Then immediately add 5 parts of low-temperature deionized water at 20-22°C to rapidly lower the system temperature to room temperature. Then place the mixture in a cold water bath at 3-5°C and stir continuously at 200 rpm for 30 minutes to obtain a completely transparent, homogeneous HPMC solution without visible particles, denoted as solution A.

[0087] (2) Preparation of sodium lignosulfonate solution

[0088] Dissolve 2.5 parts of sodium lignosulfonate powder in 9.35 parts of deionized water at 25°C. Stir the solution at 200 rpm for 30 minutes using a magnetic stirrer until a homogeneous solution is formed. This solution is denoted as solution B.

[0089] (3) Preparation of organic composite auxiliary solution

[0090] At room temperature, with a stirring speed of 200 rpm, the HPMC adhesive solution (solution A) obtained in step (1) was slowly poured into the sodium lignosulfonate solution (solution B) obtained in step (2) in four portions, with an interval of 5 minutes between each addition. After the addition was completed, stirring was continued at a stirring speed of 200 rpm for 30 minutes to ensure uniform mixing, resulting in an organic composite additive solution (solution C). The mass ratio of sodium lignosulfonate to HPMC was 1:0.02.

[0091] (4) Preparation of composite paste

[0092] At room temperature, 78.1 parts of dolomite powder (average particle size of 200 μm) were placed in a vacuum stirring container. While stirring continuously at 400 rpm, the organic composite additive solution (solution C) obtained in step (3) was slowly and evenly added to the dolomite powder to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 60 min until a paste with uniform texture, no obvious particle agglomeration, and consistent color was obtained.

[0093] (5) Vacuum defoaming

[0094] The composite paste obtained in step (4) above was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied and the mixture was processed for 60 minutes to eliminate air bubbles entrained during stirring, and the final product was obtained. The water content of the final product was 19.35 parts.

[0095] Example 4

[0096] A method for preparing an organic-inorganic composite filler paste for power applications includes the following steps:

[0097] (1) Preparation of hydroxypropyl methylcellulose gel

[0098] Weigh 0.15 parts of hydroxypropyl methylcellulose (HPMC) powder and slowly and evenly disperse it in 5 parts of deionized water preheated to 85°C while stirring at 1000 rpm, ensuring that the powder does not clump during dispersion. Immediately add 5 parts of low-temperature deionized water at 20-22°C to rapidly lower the system temperature to room temperature. Then place the mixture in a cold water bath at 3-5°C and stir continuously at 200 rpm for 30 minutes to obtain a completely transparent, homogeneous HPMC solution without visible particles, denoted as solution A.

[0099] (2) Preparation of sodium lignosulfonate solution

[0100] Dissolve 0.3 parts of sodium lignosulfonate powder in 9.35 parts of deionized water at 25°C. Stir the solution magnetically at 200 rpm for 30 minutes until a homogeneous solution is formed, which is denoted as solution B.

[0101] (3) Preparation of organic composite auxiliary solution

[0102] At room temperature, with a stirring speed of 200 rpm, the HPMC adhesive solution (solution A) obtained in step (1) was slowly poured into the sodium lignosulfonate solution (solution B) obtained in step (2) in three portions, with an interval of 10 min between each addition; after the addition was completed, stirring was continued at a stirring speed of 200 rpm for 30 min to ensure uniform mixing, resulting in an organic composite additive solution (solution C). The mass ratio of sodium lignosulfonate to HPMC was 1:0.5.

[0103] (4) Preparation of composite paste

[0104] At room temperature, 80.2 parts of dolomite powder (average particle size of 200 μm) were placed in a vacuum stirring container. While stirring continuously at 400 rpm, the organic composite additive solution (solution C) obtained in step (3) was slowly and evenly added to the dolomite powder to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 30 min until a paste with uniform texture, no obvious particle agglomeration, and consistent color was obtained.

[0105] (5) Vacuum defoaming

[0106] The composite paste obtained in step (4) above was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied and the mixture was processed for 30 minutes to eliminate air bubbles entrained during stirring, and the final product was obtained. The water content of the final product was 19.35 parts.

[0107] Example 5

[0108] A method for preparing an organic-inorganic composite filler paste for power applications includes the following steps:

[0109] (1) Preparation of hydroxypropyl methylcellulose gel

[0110] Weigh 0.15 parts of hydroxypropyl methylcellulose (HPMC) powder and slowly and evenly disperse it in 4 parts of deionized water preheated to 85°C while stirring at 1000 rpm, ensuring that the powder does not clump during the dispersion process. Then immediately add 4 parts of low-temperature deionized water at 20-22°C to rapidly lower the system temperature to room temperature. Then place the mixture in a cold water bath at 3-5°C and stir continuously at 200 rpm for 30 minutes to obtain a completely transparent, homogeneous HPMC solution without visible particles, denoted as solution A.

[0111] (2) Preparation of sodium lignosulfonate solution

[0112] Dissolve 1.5 parts of sodium lignosulfonate powder in 7.35 parts of deionized water at 25°C. Stir the solution at 200 rpm for 30 minutes using a magnetic stirrer until a homogeneous solution is formed. This solution is denoted as solution B.

[0113] (3) Preparation of organic composite auxiliary solution

[0114] At room temperature, with a stirring speed of 200 rpm, the HPMC adhesive solution (solution A) obtained in step (1) was slowly poured into the sodium lignosulfonate solution (solution B) obtained in step (2) in 5 portions, with an interval of 8 minutes between each addition; after the addition was completed, stirring was continued at a stirring speed of 200 rpm for 30 minutes to ensure uniform mixing, resulting in an organic composite additive solution (solution C). The mass ratio of sodium lignosulfonate to HPMC was 1:0.1.

[0115] (4) Preparation of composite paste

[0116] At room temperature, 83 portions of dolomite powder (average particle size of 200 μm) were placed in a vacuum stirring container. While stirring continuously at 400 rpm, the organic composite additive solution (solution C) obtained in step (3) was slowly and evenly added to the dolomite powder to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 60 min until a paste with uniform texture, no obvious particle agglomeration, and consistent color was obtained.

[0117] (5) Vacuum defoaming

[0118] The composite paste obtained in step (4) above was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied and the mixture was processed for 45 minutes to eliminate air bubbles entrained during stirring, and the final product was obtained. The water content of the final product was 15.35 parts.

[0119] Comparative Example 1

[0120] A method for preparing a filler paste for electrical applications includes the following steps:

[0121] (1) Preparation of hydroxypropyl methylcellulose gel

[0122] Weigh 0.15 parts of hydroxypropyl methylcellulose (HPMC) powder and slowly and evenly disperse it in 10.85 parts of deionized water preheated to 85°C while stirring at 1000 rpm, ensuring that the powder does not clump during dispersion. Then immediately add 10 parts of low-temperature deionized water at 20-22°C to rapidly lower the system temperature to room temperature. Then place the mixture in a cold water bath at 3-5°C and stir continuously at 200 rpm for 30 minutes to obtain a completely transparent, homogeneous HPMC solution without visible particles, denoted as solution A.

[0123] (2) Preparation of ointment

[0124] At room temperature, 79 parts of dolomite powder (average particle size of 200 μm) were placed in a vacuum stirring container. While stirring continuously at 400 rpm, the HPMC adhesive solution (solution A) obtained in step (1) was slowly and evenly added to the dolomite powder to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 45 min to obtain a paste.

[0125] (3) Vacuum defoaming

[0126] The obtained paste was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied for 45 minutes to obtain the final product, which had a water content of 20.85 parts.

[0127] Comparative Example 2

[0128] A method for preparing a filler paste for electrical applications includes the following steps:

[0129] (1) Preparation of sodium lignosulfonate solution

[0130] Dissolve 1.5 parts of sodium lignosulfonate powder in 19.5 parts of deionized water at 25°C. Stir the solution at 200 rpm for 30 minutes using a magnetic stirrer until a homogeneous solution is formed. This solution is denoted as solution B.

[0131] (2) Preparation of ointment

[0132] At room temperature, 79 portions of dolomite powder (average particle size of 200 μm) were placed in a vacuum stirring container. Solution B was slowly and evenly added to the dolomite powder while stirring continuously at 400 rpm to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 45 min to obtain a paste.

[0133] (3) Vacuum defoaming

[0134] The obtained paste was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied for 45 minutes to obtain the final product, which had a water content of 19.5 parts.

[0135] Comparative Example 3

[0136] A method for preparing a filler paste for electrical applications includes the following steps:

[0137] (1) Mixing raw materials

[0138] Weigh 15 parts of epoxy resin (Nanya NPEL-128 resin), 65 parts of talc powder, 10 parts of polyamide curing agent (Hunsman Aradur 125-3), 5 parts of flame retardant (aluminum hydroxide powder), and 3 parts of plasticizer (dioctyl phthalate, DOP), and place them in a mixing container to obtain a mixed raw material.

[0139] (2) Mixing and molding

[0140] At room temperature, 2 parts of deionized water were slowly added to the mixed raw materials at a stirring speed of 300 rpm, and the mixture was stirred for 60 minutes to obtain a homogeneous paste.

[0141] Comparative Example 4

[0142] A method for preparing a filler paste for electrical applications includes the following steps:

[0143] (1) Mixing raw materials

[0144] Ninety parts of dolomite powder (average particle size 200 μm) were placed in a stirring container.

[0145] (2) Mixing and molding

[0146] At room temperature, while stirring continuously at 300 rpm, slowly and evenly add 10 parts of deionized water to the dolomite powder to avoid local over-wetting or clumping; after the addition is complete, continue stirring for 30 minutes to obtain a loose paste.

[0147] Comparative Example 5

[0148] A method for preparing a filler paste for electrical applications includes the following steps:

[0149] (1) Raw material preparation

[0150] At room temperature, weigh 0.15 parts of hydroxypropyl methylcellulose (HPMC) powder, 1.5 parts of sodium lignosulfonate powder, and 79 parts of dolomite powder (average particle size of 200 μm). Place the three solid raw materials together in a vacuum stirring container and stir continuously at 400 rpm for 45 min to obtain a mixed solid raw material.

[0151] (2) One-time blending molding

[0152] At room temperature, while continuously stirring at 400 rpm, 19.35 parts of deionized water were slowly and evenly added to the above mixed solid raw materials to avoid local over-wetting or clumping. After the addition was completed, stirring was continued at 400 rpm for 45 minutes to obtain a paste (HPMC had not undergone high-temperature dispersion and cold water bath hydration, and there was obvious clumping).

[0153] (3) Vacuum defoaming

[0154] The obtained paste was transferred to a beaker and placed in a vacuum oven. Under conditions of 25°C, a vacuum of -0.1 MPa was applied for 45 minutes to obtain the final product.

[0155] Comparative Example 6

[0156] A method for preparing an organic-inorganic composite filler paste for power applications includes the following steps:

[0157] (1) Preparation of hydroxypropyl methylcellulose gel

[0158] Weigh 0.9 parts of hydroxypropyl methylcellulose (HPMC) powder and slowly and evenly disperse it in 5 parts of deionized water preheated to 85°C while stirring at 1000 rpm, ensuring that the powder does not clump during the dispersion process. Then immediately add 5 parts of low-temperature deionized water at 20-22°C to rapidly lower the system temperature to room temperature. Then place the mixture in a cold water bath at 3-5°C and stir continuously at 200 rpm for 30 minutes to obtain a homogeneous HPMC solution, denoted as solution A.

[0159] (2) Preparation of sodium lignosulfonate solution

[0160] Dissolve 1.5 parts of sodium lignosulfonate powder in 8.6 parts of deionized water at 25°C. Stir the solution magnetically at 200 rpm for 30 minutes until a homogeneous solution is formed, which is denoted as solution B.

[0161] (3) Preparation of composite auxiliary agent solution

[0162] At room temperature, with a stirring speed of 200 rpm, solution A was slowly poured into solution B in three portions, with an interval of 8 minutes between each addition. After the addition was complete, stirring was continued at 200 rpm for 30 minutes to obtain solution C. The mass ratio of sodium lignosulfonate to HPMC was 1:0.6.

[0163] (4) Preparation of composite paste

[0164] At room temperature, 79 portions of dolomite powder (average particle size of 200 μm) were placed in a vacuum stirring container. Solution C was slowly and evenly added to the dolomite powder while stirring continuously at 400 rpm to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 45 min to obtain a paste.

[0165] (5) Vacuum defoaming

[0166] The composite paste obtained above was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied for 45 minutes to eliminate air bubbles entrained during stirring, and the final product was obtained. The water content of the final product was 18.6 parts.

[0167] Comparative Example 7

[0168] A method for preparing an organic-inorganic composite filler paste for power applications includes the following steps:

[0169] (1) Preparation of hydroxypropyl methylcellulose gel

[0170] Weigh 0.015 parts of hydroxypropyl methylcellulose (HPMC) powder and slowly and evenly disperse it in 5 parts of deionized water preheated to 85°C while stirring at 1000 rpm, ensuring that the powder does not clump during the dispersion process. Then immediately add 5 parts of low-temperature deionized water at 20-22°C to rapidly lower the system temperature to room temperature. Then place the mixture in a cold water bath at 3-5°C and stir continuously at 200 rpm for 30 minutes to obtain a completely transparent, homogeneous HPMC solution without visible particles, denoted as solution A.

[0171] (2) Preparation of sodium lignosulfonate solution

[0172] Dissolve 1.5 parts of sodium lignosulfonate powder in 9.485 parts of deionized water at 25°C. Stir the solution at 200 rpm for 30 minutes using a magnetic stirrer until a homogeneous solution is formed. This solution is denoted as solution B.

[0173] (3) Preparation of organic composite auxiliary solution

[0174] At room temperature, with a stirring speed of 200 rpm, the HPMC adhesive solution (solution A) obtained in step (1) was slowly poured into the sodium lignosulfonate solution (solution B) obtained in step (2) in three portions, with an interval of 8 minutes between each addition, to allow the HPMC adhesive solution and the sodium lignosulfonate solution to mix thoroughly. After the addition was completed, stirring was continued at a stirring speed of 200 rpm for 30 minutes to ensure uniform mixing, resulting in an organic composite additive solution (solution C). The mass ratio of sodium lignosulfonate to HPMC was 1:0.01.

[0175] (4) Preparation of composite paste

[0176] At room temperature, 79 parts of dolomite powder (average particle size of 200 μm) were placed in a vacuum stirring container. While stirring continuously at 400 rpm, the organic composite additive solution (solution C) obtained in step (3) was slowly and evenly added to the dolomite powder to avoid local over-wetting or clumping. After the addition was completed, the mixture was stirred continuously at 400 rpm for 45 min until a paste with uniform texture, no obvious particle agglomeration, and consistent color was obtained.

[0177] (5) Vacuum defoaming

[0178] The composite paste obtained above was transferred to a beaker and placed in a vacuum oven. At 25°C, a vacuum of -0.1 MPa was applied for 45 minutes to eliminate air bubbles entrained during stirring, and the final product was obtained. The water content of the final product was 19.485 parts.

[0179] Performance testing

[0180] (1) FTIR-TG combined three-dimensional spectrum

[0181] Thermogravimetric-Infrared (TGA) system (PerkinElmer TGA8000 + Spectrum 3) was used for analysis. Before sample preparation, the paste sample from Example 1 was dried to constant weight at 60°C to remove free water. Approximately 10 mg of the dried homogeneous sample was weighed and spread in a thin layer in an open alumina crucible. The temperature was programmed to rise from room temperature to 1000°C at a rate of 20°C / min. The sample mass change was monitored in real time, and infrared spectra were acquired simultaneously to characterize the correlation between the thermal decomposition process of the sample and the infrared absorption signal.

[0182] (2) TG-DTG curve

[0183] Thermogravimetric-infrared spectroscopy (TGA-IR) system (PerkinElmer TGA8000+Spectrum 3) was also used for analysis. Mass changes were monitored in real time, and infrared spectroscopy was used to detect the gases released by thermal decomposition and perform differentiation.

[0184] (3) Fourier transform infrared spectrum

[0185] The following five groups of samples were tested and analyzed using a Fourier transform infrared spectrometer (Nicolet 6700, Thermo Scientific, USA): the composite filler paste (DLP) prepared in Example 1 of this invention, the physically simple blend sample (PM) with the same components, the single organic components sodium lignosulfonate (SLS) and hydroxypropyl methylcellulose (HPMC), and the inorganic component dolomite powder.

[0186] (4) Dispersion stability

[0187] Optical microscopy image analysis was used for determination, employing an Olympus BX53 optical microscope and its accompanying image analysis software. A composite paste sample was uniformly coated onto a clean glass slide, with a coating thickness controlled at 50 μm. The slide was placed on the microscope stage, and five different areas were selected for observation and high-resolution images were acquired. After sealing and storing the sample for one month, the above test steps were repeated, and changes in particle dispersion before and after storage were compared. The purpose of the test was to evaluate the uniformity of inorganic particle dispersion and long-term storage stability in the composite paste.

[0188] No aggregation: Compared with before storage, the particles are dispersed and there is no obvious aggregation;

[0189] Obvious aggregation: Compared with before storage, the particle size has increased and aggregation has occurred.

[0190] (5) Heat dissipation performance

[0191] Thermal resistance was measured using the heat flow method. A NETZSCH HFM 436 / 3 / 1E heat flow meter was used for thermal resistance testing. A composite paste sample was uniformly coated onto a standard metal substrate to prepare a test sample measuring 100mm × 100mm × 5mm. The heat flow density was set to 500 W / m³ at a constant ambient temperature of 25℃. 2 Record the thermal resistance value after the test data stabilizes.

[0192] (6) Cable current carrying capacity improvement rate

[0193] The current carrying capacity improvement rate was calculated using a cable simulation experiment. A Φ18mm copper core cable was used as the simulation object. The sample was uniformly wrapped around the cable surface with a wrapping thickness of 3mm. Under standard operating conditions (ambient temperature 25℃, wind speed 0.5m / s), the rated current carrying capacity of the cable was measured. Simultaneously, an unwrapped cable was used as a blank control group to calculate the current carrying capacity improvement rate.

[0194] (7) Fire resistance and high temperature resistance

[0195] Thermogravimetric analysis was performed using the PerkinElmer TGA8000+Spectrum 3 thermogravimetric-infrared system described above. The test parameters were consistent with those used in the TG-DTG curve test (drying to constant weight at 60℃, 10mg sample, heating to 1000℃ at 20℃ / min). The residual mass percentage at 1000℃ was recorded (see Example 1 for details). Figure 2 ).

[0196] The direct ignition method uses an alcohol torch as the ignition source. The sample is made into a block of 50mm×50mm×10mm, dried at 50℃ to constant weight, placed on a fireproof test rack, and the sample surface is directly burned with the outer flame of the torch. The flame height is controlled at 50mm and the burning time is 30s. The sample is observed to see if it burns, whether there is flame spread, and the structural integrity after burning.

[0197] Non-flammable: The sample does not burn, there is no flame spread, it extinguishes immediately after burning, and the structure remains intact.

[0198] Combustible: The sample burns after being ignited, with flames spreading and continuing to burn after ignition, resulting in partial structural ablation.

[0199] (8) Rheological properties

[0200] The rheological properties were tested using a Kinexus Pro+ rotational rheometer. The rheological properties were measured using dynamic strain scanning, recording the complex viscosity as a function of shear strain to characterize the viscoelastic response of the material under different strains. (See Example 1 for details.) Figure 4 ).

[0201] (9) Construction performance

[0202] Construction performance was evaluated through pumping and coating tests. A small screw pump was used to simulate the actual pumping process, and the pumping performance was observed. A coating roller was used to coat the sample onto the cable surface, and the uniformity of the coating and the absence of sagging or wrinkling were observed.

[0203] Excellent workability: stable pumping and uniform coating;

[0204] Good workability: It can be basically pumped, and the coating is basically uniform;

[0205] Poor workability: difficult to pump, uneven coating.

[0206] Table 1 Test Indicators of Examples 1-5 and Comparative Examples 1-7

[0207]

[0208] (In Table 1, " / " in the "Other Phenomena" column refers to other phenomena that do not require a note.)

[0209] The product of Example 1 was subjected to thermogravimetric-infrared spectroscopy analysis, and the three-dimensional spectrum of the decomposition process using FTIR-TG is shown below. Figure 1 As shown, it can be seen that at 1000-1100cm -1 Significant and stable infrared absorption peaks exist in the wavenumber range, corresponding to a stable silicate or oxide network structure that does not decompose during heating, providing the material with excellent structural thermal stability and a passive fire barrier.

[0210] pass Figure 2The TG-DTG curves show that the composite filler paste prepared in Example 1 exhibits a significant mass loss step in the temperature range of 500-800°C. This stage is mainly attributed to the endothermic decomposition reaction of the dolomite component in the system. Dolomite (mainly composed of CaMg(CO3)2) decomposes during heating, generating calcium oxide (CaO) and magnesium oxide (MgO), and releasing carbon dioxide (CO2) gas. This decomposition process is a strongly endothermic reaction, which can effectively absorb a large amount of heat in the fire environment, significantly reducing the temperature of the material and the surrounding environment, thereby delaying the combustion process. At the same time, the CaO and MgO produced by decomposition are alkaline oxides with high melting points and high thermal stability. They further react or melt at high temperatures to form a stable ceramic-like thermal insulation skeleton structure. This skeleton has excellent thermal insulation, chemical inertness, and structural integrity, which can effectively block heat conduction and flame spread. When the test endpoint temperature reaches 1000°C, the residual mass of the system still remains at about 54%, indicating that after high-temperature decomposition, the material forms a stable inorganic residue mainly composed of CaO and MgO, constituting a key barrier for passive fire protection. In addition, the CO2 gas released during the decomposition process can also dilute the oxygen concentration, further inhibiting the continued combustion reaction.

[0211] The Fourier transform infrared (FTIR) spectra of the final product of Example 1 were compared with those of its individual components and physical mixtures, respectively. (See attached image.) Figure 3 Between 3000-3600cm -1 In the OH stretching vibration region, the absorption band of the composite paste (DLP) is significantly broadened and red-shifted compared to the physical mixture (PM) of dolomite, sodium lignosulfonate, and hydroxypropyl methylcellulose. This indicates that the process of this invention can induce the formation of a stronger and more complex hydrogen bond network in the composite filler paste, with an interaction strength superior to that of a simple physical mixture of components. (1000-1250 cm⁻¹) -1 In the characteristic vibration region of sulfonic acid groups, the absorption peak of DLP showed a significant shift in peak position and shape compared to pure sodium lignosulfonate and PM, confirming that there is a specific chemical interaction between the functional groups of sodium lignosulfonate and the surface of dolomite particles, such as strong hydrogen bonds or ion-dipole interactions, rather than simple physical adsorption.

[0212] Figure 4 The complex viscosity-shear strain curve of the composite filler paste in Example 1 shows that the composite paste exhibits shear-thinning characteristics; as the shear strain increases, its complex viscosity gradually decreases from 4 Pa·s to nearly 0. This indicates that it has good flowability and workability under high shear, flows easily under construction shear force, and can quickly recover structural strength after construction.

[0213] Please refer to Table 1. Based on Examples 1-5 and Comparative Examples 1-7, it can be seen that the products of the examples all exhibit excellent comprehensive performance: good dispersibility, no agglomeration after one month of storage, effectively solving the problem of easy agglomeration of inorganic particles in high solid content systems; thermal resistance per unit area ≤0.67K. m 2 / W, the steady-state current carrying capacity of the cable is increased by 30%-50%, significantly improving the problem of poor heat dissipation of traditional materials; the residual mass at 1000℃ is high and non-flammable, and it decomposes under heat at 500-800℃ to form a ceramic-like heat insulation skeleton, while avoiding the defects of flammability of organic materials and brittleness of inorganic materials, and its construction adaptability is also excellent. In Example 3, the amount of HPMC added was low, resulting in slightly insufficient particle dispersion stability and three-dimensional network strength of the system; in Example 4, the amount of sodium lignosulfonate added was low, affecting the dispersion uniformity; in Example 5, the dolomite content was high, increasing the dispersion difficulty; while Comparative Examples 1, 2, and 4, which lacked any organic additives or had no organic additives, had poor dispersibility, obvious agglomeration after storage, and a current carrying capacity increase of less than 25%, resulting in poor construction performance; Comparative Examples 6 and 7, where the proportion of organic additives was not within the specified range, had deficiencies in heat dissipation and stability; Comparative Example 3, a traditional organic-based material, was flammable, and the current carrying capacity increase was only 8%; Comparative Example 5, with improper preparation process, had poor dispersion stability and insufficient static stability. It can be seen that although the overall performance of Examples 3-5 is slightly worse than that of Examples 1-2, it is significantly better than that of Comparative Examples 1-7.

[0214] The above results demonstrate that this invention, through the synergistic effect of a unique interface modifier and a network builder, achieves efficient dispersion of inorganic particles and stable control of the macroscopic rheological properties of the paste. This enables the composite filled paste to simultaneously possess excellent rheological properties and long-term storage stability, solving the core problem of coexisting dispersibility and stability in high-solids content systems. Furthermore, the composite filled paste of this invention exhibits a low thermal resistance per unit area of ​​0.53-0.67 K·m. 2 / W, significantly superior to traditional materials, can effectively reduce conductor operating temperature and support a 30%-50% increase in steady-state current carrying capacity of cable systems, solving the problem of poor heat dissipation caused by the high thermal resistance of traditional filler materials. This invention utilizes the inorganic nature of dolomite to endow the material with non-combustibility and high-temperature stability, fundamentally overcoming the flammability defects of organic fireproof putty. Simultaneously, through the plasticizing and binding effects of organic components, it avoids the brittle cracking and construction compatibility issues of purely inorganic materials. In the temperature range of 500-800°C, the dolomite components undergo an endothermic decomposition reaction, effectively absorbing fire fumes. The large amount of heat generated during decomposition significantly reduces the temperature of the material and its surrounding environment. The CaO and MgO produced during decomposition form a stable ceramic-like thermal insulation framework structure with excellent thermal insulation, chemical inertness, and structural integrity. At a high temperature of 1000°C, the residual mass of the system remains above 50%, forming a stable inorganic composite system mainly composed of CaO and MgO. This composite system easily forms a dense, thermally stable ceramic-like thermal insulation framework at high temperatures. The CO2 gas released during decomposition can dilute the oxygen concentration, further inhibiting the combustion reaction.

[0215] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing an organic-inorganic composite filler paste for power applications, characterized in that, Includes the following steps: Preparation of single solutions: Preparation of network building agent solution and interface modifier solution; Preparation of organic composite auxiliary agent solution: Mix the network builder solution and the interface modifier solution evenly to obtain the organic composite auxiliary agent solution; Mixing and molding: The inorganic matrix and the organic composite additive solution are mixed evenly to obtain a preliminary composite paste; Vacuum degassing: The preliminary composite paste is degassed under vacuum to obtain an organic-inorganic composite filler paste for electrical applications; wherein, The organic-inorganic composite filler paste for power applications comprises: an inorganic matrix, an organic composite additive, and water; the inorganic matrix is ​​dolomite; the organic composite additive consists of an interface modifier and a network building agent, wherein the interface modifier is at least one of sodium lignosulfonate and calcium lignosulfonate, and the network building agent is hydroxypropyl methylcellulose; the mass ratio of the interface modifier to the network building agent is 1:(0.02-0.5); in the organic-inorganic composite filler paste for power applications, the inorganic matrix accounts for 60%-83% of the mass, the organic composite additive accounts for 0.4%-4% of the mass, and the water accounts for 15%-25% of the mass. The preparation of the network building agent solution includes: dispersing the network building agent in a first water preheated to 80-90°C at a first stirring rate, then rapidly lowering the system temperature to room temperature, and then placing the mixture in a cold water bath at 2-10°C and subjecting it to a first stirring treatment to obtain the network building agent solution.

2. The method for preparing the organic-inorganic composite filler paste for power applications according to claim 1, characterized in that, The average particle size of the inorganic matrix is ​​10-500 μm.

3. The method for preparing the organic-inorganic composite filler paste for power applications according to claim 1, characterized in that, The aforementioned organic-inorganic composite filler paste for power applications further includes: functional fillers; wherein, The functional filler is at least one of boron nitride, alumina, and expanded graphite; and / or, The average particle size of the functional filler is 5-200 μm; and / or, In the aforementioned organic-inorganic composite filler paste for power applications, the functional filler accounts for 0%-15% of the total mass.

4. The method for preparing the organic-inorganic composite filler paste for power applications according to claim 1, characterized in that, Mix the network builder and the first water with the second water at 15-25°C, allowing the system temperature to rapidly decrease to room temperature; and / or, The total mass percentage of the first water and the second water is 50%-55% of the total water volume; and / or, The mass ratio of the first water to the second water is 1:(0.8-1.2); and / or, The first stirring rate is 800-1500 rpm; and / or, During the first stirring process, the stirring rate is 100-300 rpm and the stirring time is 0.3-1 h.

5. The method for preparing the organic-inorganic composite filler paste for power applications according to claim 1, characterized in that, The preparation of the interface modifier solution includes: dispersing the interface modifier in a third type of water, followed by a second stirring treatment to obtain the interface modifier solution; wherein, During the second stirring process, the temperature is room temperature, the stirring rate is 100-300 rpm, and the time is 30-60 min.

6. The method for preparing the organic-inorganic composite filler paste for power applications according to claim 1, characterized in that, At a second stirring rate, the network builder solution is added to the interface modifier solution, followed by a third stirring treatment to obtain an organic composite auxiliary solution; wherein, The network builder solution is added to the interface modifier solution in batches, 2-5 times, with an interval of 5-10 minutes between each addition; and / or, The second stirring rate is 100-300 rpm; and / or, During the third stirring process, the temperature is room temperature, the stirring rate is 100-300 rpm, and the stirring time is 30-60 min.

7. The method for preparing the organic-inorganic composite filler paste for power applications according to claim 1, characterized in that, At a third stirring rate, the organic composite additive solution is added to the inorganic matrix, and after a fourth stirring treatment, a preliminary composite paste is obtained; wherein, The third stirring rate is 300-500 rpm; and / or, During the fourth stirring process, the stirring temperature is room temperature, the stirring speed is 300-500 rpm, and the stirring time is 0.2-2 h.

8. The method for preparing the organic-inorganic composite filler paste for power applications according to claim 3, characterized in that, The inorganic matrix, functional filler, and organic composite additive solution are mixed evenly to obtain a preliminary composite paste; or, The preliminary composite paste and functional filler are mixed and then subjected to a fifth stirring treatment; during the fifth stirring treatment, the temperature is room temperature, the stirring rate is 300-500 rpm, and the stirring time is 0.2-2 hours; and / or, During the vacuum degassing process, the temperature is room temperature, the vacuum degree is -0.095MPa to -0.1MPa, and the time is 0.5-1.5h.

9. An organic-inorganic composite filler paste for power applications, characterized in that, The organic-inorganic composite filler paste for power applications is obtained by the preparation method of an organic-inorganic composite filler paste for power applications as described in any one of claims 1-8.

10. The application of the organic-inorganic composite filler paste for power applications as described in claim 9 in cable filling and fireproofing.

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