Sandwich structure basalt laminate with synergistic hydrophobic anti-flashover and insulation flame-retardant and preparation method thereof

Abstract

The application belongs to the technical field of power equipment protection materials, and discloses a sandwich structure basalt laminated board with hydrophobic anti-flashover and insulation flame-retardant synergy and a preparation method thereof. The laminated board comprises two layers of hydrophobic anti-flashover outer layers and an insulation flame-retardant inner layer sandwiched between the two layers of hydrophobic anti-flashover outer layers; the hydrophobic anti-flashover outer layers and the insulation flame-retardant inner layer both adopt modified basalt fiber cloth as a reinforcing framework, and take epoxy resin as a matrix; the hydrophobic anti-flashover outer layer matrix is compounded with a hydrophobic anti-pollution core-shell functional filler, and the insulation flame-retardant inner layer matrix is compounded with a high-temperature porcelain-forming flame-retardant insulation molecular sieve filler. The board has a high water contact angle, a high volume resistivity, a long arc resistance time, and a flame-retardant grade of UL-94 V-0@3 mm, and is suitable for use in the insulation protection of electric control cabinets, power distribution cabinets and ring network cabinets under high-humidity, high-pollution and salt spray corrosion working conditions.

Description

Technical Field

[0001] This invention relates to the field of power equipment protection materials technology, specifically to a sandwich structure basalt laminate with hydrophobic anti-flashover and insulating flame retardant properties, and its preparation method. Background Technology

[0002] The description of the background art in this invention pertains to related technologies and is used merely for illustration and to facilitate understanding of the invention. It should not be construed as the applicant explicitly believing or presuming that the invention was prior art on the filing date of the first application.

[0003] As my country's power infrastructure expands into coastal, humid, heavy industrial areas and high-altitude salt spray zones, power equipment such as distribution automation stations and switchgear operate under conditions of high humidity (RH≥85%), high pollution (dust / salt spray), and high corrosion (SO2 / C). - In environments with limited internal cavities and poor heat dissipation, water films easily condense on the insulating surfaces, forming conductive contaminants that can induce increased surface leakage current, tracking, partial discharge, and flashover. More seriously, when an internal short circuit occurs, the instantaneous electric arc (temperature >1000℃) can easily scorch ordinary insulating partitions, leading to an escalation of the accident.

[0004] To address the aforementioned problems, current solutions often employ homogeneous filled functional filler insulating laminates and single or composite insulating functional coatings. For example, CN119081191A discloses a halogen-free flame-retardant benzoxazine-modified epoxy glass cloth laminate and its preparation method. A prepreg is prepared by impregnating glass cloth with a composition of benzoxazine-modified epoxy resin and phosphorus-based flame-retardant functional filler, followed by hot pressing to obtain the halogen-free flame-retardant benzoxazine-modified epoxy glass cloth laminate. While this invention improves the flame-retardant capability of the material through the synergistic effect of intrinsic materials and additive flame retardants, it only involves the addition of a single flame-retardant functional filler and still cannot solve the problem of hydrophobicity and antifouling in high-humidity and high-pollution environments. CN110183824A discloses a thermally conductive and insulating epoxy resin laminate composite material, its preparation method, and its application. A modified glass cloth layer containing epoxy groups is used as a reinforcing material, and a uniformly dispersed spherical boron nitride epoxy resin is used as the matrix. The resulting epoxy resin laminate composite material possesses good mechanical properties, thermal conductivity, and insulation properties. However, it only achieves uniform dispersion and is not designed with an epoxy reaction end. High addition amounts will lead to increased viscosity, affecting interfacial compatibility with the resin. Furthermore, it has a single function and lacks hydrophobic and anti-flashover capabilities.

[0005] CN121652678A discloses a polyurea-epoxy-acrylic composite coating material, its preparation method, and its application. This material introduces three functional nanomaterials into a composite material based on an interpenetrating network of polyurea, epoxy resin, and acrylic resin, forming a composite coating material with a ternary synergistic structure of insulation and thermal conductivity, ceramic flame retardancy, and hydrophobic anti-flashover. However, it is essentially a surface coating layer, lacking continuous fiber reinforcement and self-supporting structure. Its resistance to mechanical impact and thermal shock is weak, and it suffers from potential failures such as coating cracking and peeling. Furthermore, it lacks functional partitioning, with hydrophobic, insulating, and flame-retardant functions homogeneously coupled. Once these functions fail, they cannot achieve progressive dissipation and redundant protection, leading to an instantaneous paralysis of overall insulation and flame-retardant functions, and thus lacking multi-level protection capabilities against catastrophic conditions.

[0006] Therefore, how to construct a synergistic enhancement mechanism of hydrophobic anti-flashover and insulation flame retardancy in the same system, and form a stepwise dissipation and redundant protection of functions to meet the long-term and safety requirements of electrical control cabinets for insulation protection in high humidity and high pollution environments, is an urgent research direction and technical challenge. Summary of the Invention

[0007] The purpose of this invention is to provide a sandwich-structured basalt laminate with synergistic hydrophobic flashover resistance and insulating flame retardancy, and its preparation method. This invention achieves synergistic hydrophobic flashover resistance, insulating flame retardancy, and arc resistance through filler modification, fiber surface modification, and sandwich layered structure design, possessing functionally progressively dissipative redundancy protection capabilities.

[0008] The objective of this invention is achieved through the following technical solutions: A sandwich-structured basalt laminate with synergistic hydrophobic flashover resistance and insulating flame retardancy comprises two hydrophobic flashover resistance outer layers and an insulating flame retardant inner layer sandwiched between the two hydrophobic flashover resistance outer layers; both the hydrophobic flashover resistance outer layers and the insulating flame retardant inner layer use modified basalt fiber cloth as a reinforcing skeleton and epoxy resin as a matrix; the hydrophobic flashover resistance outer layer matrix is ​​compounded with hydrophobic anti-fouling core-shell functional filler, and the insulating flame retardant inner layer matrix is ​​compounded with high-temperature ceramic flame retardant insulating molecular sieve filler.

[0009] Furthermore, based on the total thickness of the laminate, the thickness of the hydrophobic and anti-flashover outer layer accounts for 10%-15%, while the thickness of the insulating and flame-retardant inner layer accounts for 85%-90%.

[0010] Furthermore, the hydrophobic and antifouling core-shell functional filler is a PTFE@SiO2 core-shell filler, with PTFE micropowder having a particle size of 0.5-3μm, and the SiO2 shell layer grafted with epoxy reactive groups through a silane coupling agent; the amount of the PTFE@SiO2 core-shell filler added to the hydrophobic and antifouling outer epoxy resin matrix is ​​3-5wt%; the silane coupling agent is selected as γ-glycidoxypropyltrimethoxysilane KH-560.

[0011] Furthermore, the high-temperature ceramic flame-retardant insulating molecular sieve filler is a SAPO-34 molecular sieve modified with a silane coupling agent, and the amount of modified SAPO-34 added to the insulating flame-retardant inner layer epoxy resin matrix is ​​1-2 wt%; the surface of the SAPO-34 molecular sieve is grafted with epoxy reactive end groups.

[0012] Furthermore, the modified basalt fiber cloth is designated as BF@SiO2@BN, and is prepared as follows: the basalt fiber cloth is first deposited with SiO2 by sol-gel method to obtain SiO2@BF intermediate fiber cloth; hexagonal boron nitride h-BN is coated with polydopamine PDA biomimetic self-polymerization to obtain h-BN@PDA powder; SiO2@BF is immersed in h-BN@PDA slurry to impregnate and pull up the loaded boron nitride sheets, and then treated with KH-560 ethanol solution, washed and dried to obtain BF@SiO2@BN modified basalt fiber cloth.

[0013] A method for preparing a sandwich-structured basalt laminate with synergistic hydrophobic flashover resistance and insulating and flame-retardant properties includes the following steps: S1. Filler preparation: Prepare PTFE@SiO2 core-shell filler with surface-grafted epoxy groups, and at the same time prepare silane-modified SAPO-34 molecular sieve filler. S2. Fiber modification: Basalt fiber cloth is modified to obtain BF@SiO2@BN modified fiber cloth; S3. Preparation of semi-cured sheets: PTFE@SiO2 core-shell filler is dispersed in epoxy resin, impregnated with BF@SiO2@BN modified fiber cloth, and rolled and dried to prepare the outer semi-cured sheet; modified SAPO-34 molecular sieve is dispersed in epoxy resin, impregnated with BF@SiO2@BN modified fiber cloth, and rolled and dried to prepare the inner semi-cured sheet. S4. Hot-press co-curing molding: The materials are stacked in the following order: hydrophobic anti-flashover outer semi-cured sheet - insulating flame-retardant inner semi-cured sheet - hydrophobic anti-flashover outer semi-cured sheet. The materials are then hot-pressed and cured in sections with controlled temperature and pressure to obtain a sandwich structure basalt laminate.

[0014] Furthermore, the preparation process of the PTFE@SiO2 core-shell filler in S1 is as follows: PTFE micro powder is activated with sodium naphthalene complex, dispersed in an ethanol-water mixed solvent, pH controlled at 4-5, grafted with KH-560 at 60-70℃, and then PTFE@SiO2 with epoxy groups on the surface is obtained by using tetraethyl orthosilicate (TEOS) as a precursor and ammonia water as a catalyst for sol-gel reaction.

[0015] Furthermore, the modified SAPO-34 molecular sieve preparation process in step S1 is as follows: SAPO-34 molecular sieve is ball-milled to break up agglomerates, dispersed in an ethanol-water mixed solvent, and KH-560 is grafted into the epoxy reaction end at 60-70℃ to obtain silane-modified SAPO-34.

[0016] Furthermore, the prepreg preparation parameters in step S3 are: rolling speed 0.3-2.0 m / min, drying temperature 80-120℃, and prepreg adhesive content controlled at 35-45 wt%.

[0017] Further, step S4 is a segmented hot-pressing and co-curing process: First step, heat preservation at 80-90℃ for 1-2 hours, pressure 0-1MPa; second step, hot pressing at 130-150℃ for 2-4 hours, pressure 2-6MPa; third step, post-curing at 150-160℃ for 4-6 hours, to complete curing and obtain the finished laminate.

[0018] The embodiments of the present invention have the following beneficial effects: Dual-state collaborative multi-level barrier protection: Under normal operating conditions, the outer PTFE@SiO2 layer constructs a micro-nano rough superhydrophobic surface to block the adhesion of dust, salt spray and water vapor and suppress flashover; in the event of an electric arc disaster, the inner SAPO-34 high-temperature conversion dense ceramic layer resists electric arc ablation; sandwich functional partitioning ensures that local damage will not directly cause the overall insulation protection to fail, achieving redundant protection.

[0019] Interface modification design: PTFE@SiO2 shell grafted with epoxy groups solves the debonding problem between polytetrafluoroethylene and epoxy resin interface; SAPO-34 silane modification balances resin bonding strength and high-temperature ceramic formation capability; boron nitride is bridged on the basalt fiber surface through polydopamine to construct a continuous thermally conductive and insulating interface, improving the overall interface bonding strength and long-term service reliability.

[0020] Functional zoning avoids performance incompatibilities: the outer layer focuses on hydrophobic and anti-flashover, while the inner layer focuses on insulation, flame retardancy, and anti-arc properties. This distinguishes it from traditional homogeneous blended boards and avoids the performance constraints caused by homogeneous doping of multiple fillers, resulting in balanced and excellent overall performance. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the laminate in this invention; Figure 2 This is a flowchart illustrating the laminate preparation process in this invention. Detailed Implementation

[0022] The present application will be further described below with reference to the embodiments.

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, in the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Different embodiments can be substituted or combined, and for those skilled in the art, other implementation methods can be obtained based on these embodiments without creative effort.

[0024] Combined with appendix Figure 1 A sandwich-structured basalt laminate with synergistic hydrophobic flashover resistance and insulating flame retardancy is disclosed, comprising two hydrophobic flashover resistance outer layers 10 and an insulating flame retardant inner layer 20 sandwiched between the two hydrophobic flashover resistance outer layers 10. Both the hydrophobic flashover resistance outer layers 10 and the insulating flame retardant inner layer 20 utilize modified basalt fiber cloth as a reinforcing skeleton and epoxy resin as the matrix. The hydrophobic flashover resistance outer layer 10 matrix is ​​compounded with hydrophobic anti-fouling core-shell functional fillers, while the insulating flame retardant inner layer 20 matrix is ​​compounded with high-temperature ceramic flame retardant insulating molecular sieve fillers. It should be noted that this design aims to achieve both hydrophobic flashover resistance and insulating flame retardant properties, thereby improving the reliability of the insulating arc-resistant board in complex environments. The overall impact-resistant skeleton material is selected from basalt fiber, which has excellent mechanical, insulating, and weather-resistant properties and is inexpensive. SiO2 and BN are deposited on the fiber surface to further improve its thermal conductivity and insulation performance. The matrix material is designed with the addition of PTFE@SiO2 and modified SAPO-34 to improve its hydrophobic, anti-fouling, flame-retardant, and insulating properties. To achieve a step-by-step dissipation and redundancy protection mechanism, this invention designs a sandwich laminate structure. The outer layer is a composite of BF@SiO2@BN and PTFE@SiO2 / EP (EP is epoxy resin). The low surface energy of PTFE and the micro-nano rough structure of the SiO2 shell are used to construct a superhydrophobic surface to block the adhesion of wet dirt. The inner layer is a composite of BF@SiO2@BN and modified SAPO-34 / EP. The dense ceramic hard layer is formed by sintering the inorganic microporous skeleton structure of SAPO-34 at high temperature. This, combined with the insulating and thermal conductivity properties of the BF@SiO2@BN system, achieves efficient flame retardancy and carbon suppression, as well as long-term insulation stability.

[0025] Furthermore, based on the total thickness of the laminate, the hydrophobic and anti-flashover outer layer 10 accounts for 10%-15% of the thickness, while the insulating and flame-retardant inner layer 20 accounts for 85%-90%. The outer layers are symmetrical on both sides and have equal thickness.

[0026] Furthermore, the hydrophobic and antifouling core-shell functional filler is a PTFE@SiO2 core-shell filler, with PTFE micropowder having a particle size of 0.5-3μm, and the SiO2 shell layer grafted with epoxy reactive groups through a silane coupling agent; the amount of the PTFE@SiO2 core-shell filler added to the hydrophobic and antifouling outer epoxy resin matrix is ​​3-5wt%; the silane coupling agent is selected as γ-glycidoxypropyltrimethoxysilane KH-560.

[0027] Furthermore, the high-temperature ceramic flame-retardant insulating molecular sieve filler is a SAPO-34 molecular sieve modified with a silane coupling agent, and the amount of modified SAPO-34 added to the epoxy resin matrix of the insulating and flame-retardant inner layer 20 is 1-2 wt%; epoxy reactive end groups are grafted onto the surface of the SAPO-34 molecular sieve to enhance the interfacial bonding with the epoxy resin.

[0028] Furthermore, the modified basalt fiber cloth is designated as BF@SiO2@BN, and is prepared as follows: the basalt fiber cloth is first deposited with SiO2 by sol-gel method to obtain SiO2@BF intermediate fiber cloth; hexagonal boron nitride h-BN is coated with polydopamine PDA biomimetic self-polymerization to obtain h-BN@PDA powder; SiO2@BF is immersed in h-BN@PDA slurry to impregnate and pull up the loaded boron nitride sheets, and then treated with KH-560 ethanol solution, washed and dried to obtain BF@SiO2@BN modified basalt fiber cloth.

[0029] Combined with appendix Figure 2 A method for preparing a sandwich-structured basalt laminate with synergistic hydrophobic flashover resistance and insulating and flame-retardant properties includes the following steps: S1. Filler preparation: Prepare PTFE@SiO2 core-shell filler with surface-grafted epoxy groups, and at the same time prepare silane-modified SAPO-34 molecular sieve filler. S2. Fiber modification: Basalt fiber cloth is modified to obtain BF@SiO2@BN modified fiber cloth; S3. Preparation of semi-cured sheets: PTFE@SiO2 core-shell filler is dispersed in epoxy resin, impregnated with BF@SiO2@BN modified fiber cloth, and rolled and dried to prepare the outer semi-cured sheet; modified SAPO-34 molecular sieve is dispersed in epoxy resin, impregnated with BF@SiO2@BN modified fiber cloth, and rolled and dried to prepare the inner semi-cured sheet. S4. Hot-press co-curing molding: The materials are stacked in the following order: hydrophobic and anti-flashover outer layer 10 semi-cured sheet - insulating and flame-retardant inner layer 20 semi-cured sheet - hydrophobic and anti-flashover outer layer 10 semi-cured sheet. The materials are then hot-pressed and cured in sections with controlled temperature and pressure to obtain a sandwich structure basalt laminate.

[0030] Furthermore, the preparation process of the PTFE@SiO2 core-shell filler in S1 is as follows: PTFE micro powder is activated with sodium naphthalene complex, dispersed in an ethanol-water mixed solvent, pH controlled at 4-5, grafted with KH-560 at 60-70℃, and then PTFE@SiO2 with epoxy groups on the surface is obtained by using tetraethyl orthosilicate (TEOS) as a precursor and ammonia water as a catalyst for sol-gel reaction.

[0031] Furthermore, the modified SAPO-34 molecular sieve preparation process in step S1 is as follows: SAPO-34 molecular sieve is ball-milled to break up agglomerates, dispersed in an ethanol-water mixed solvent, and KH-560 is grafted into the epoxy reaction end at 60-70℃ to obtain silane-modified SAPO-34.

[0032] Furthermore, the prepreg preparation parameters in step S3 are: rolling speed 0.3-2.0 m / min, drying temperature 80-120℃, and prepreg adhesive content controlled at 35-45 wt%.

[0033] Further, step S4 is a segmented hot-pressing and co-curing process: First step, heat preservation at 80-90℃ for 1-2 hours, pressure 0-1MPa; second step, hot pressing at 130-150℃ for 2-4 hours, pressure 2-6MPa; third step, post-curing at 150-160℃ for 4-6 hours, to complete curing and obtain the finished laminate.

[0034] Example 1

[0035] 1. Packing material preparation 1) Preparation of PTFE@SiO2: PTFE micro powder was activated by sodium naphthalene complex and introduced into the surface reaction sites. Then it was dispersed in an ethanol / water mixed solvent and treated with KH-560 at 70°C under pH 5 to graft an epoxy silane layer. Then, using tetraethyl orthosilicate (TEOS) as a precursor and ammonia water as a catalyst, PTFE@SiO2 with epoxy groups on the surface was prepared by sol-gel method.

[0036] 2) Preparation of modified SAPO-34: After removing agglomerates by ball milling, SAPO-34 molecular sieves are dispersed in an ethanol / water mixed solvent and treated with KH-560 at 70°C to introduce the epoxy reaction end, thus obtaining silane-modified SAPO-34.

[0037] 2. Fiber Modification 1) Basalt fiber (BF) is first coated with SiO2 sol-gel to obtain SiO2@BF intermediate fiber cloth; 2) The hexagonal boron nitride (h-BN) sheets are then coated with polydopamine (PDA) biomimetic self-polymerization to obtain h-BN@PDA powder; 3) Immerse BF@SiO2 in a slurry containing h-BN@PDA and pull it to load h-BN@PDA sheets onto the surface of BF@SiO2. Then treat it in an ethanol solution containing KH-560 at 70°C, and then wash and dry it to obtain BF@SiO2@(h-BN@PDA) fiber cloth, abbreviated as BF@SiO2@BN.

[0038] 3. Preparation of prepreg: 1) Outer layer semi-cured sheet: 4 wt% PTFE@SiO2 is uniformly dispersed in epoxy resin, BF@SiO2@BN fiber cloth is impregnated by hand lay-up, and dried at 0.6 m / min and 90℃ to obtain an outer layer semi-cured sheet with a resin content of 40 wt% BF@SiO2@BN and PTFE@SiO2 / EP composite. 2) Inner layer semi-cured sheet: The prepared 1.5wt% slightly silane-modified SAPO-34 was uniformly dispersed in epoxy resin, impregnated with BF@SiO2@BN fiber cloth, and dried at 90℃ after roller pressing speed of 1.0 m / min. The inner layer semi-cured sheet with a glue content of 42wt% was obtained after composite of BF@SiO2@BN and modified SAPO-34 / EP. 4. Laminate preparation 1) Lay out the outer semi-cured sheet, the inner semi-cured sheet and the outer semi-cured sheet in sequence in the mold; 2) Place the laid-out semi-cured sheet on a hot press platform and keep it at a pressure of 0.5 MPa and a temperature of 85°C for 1.5 hours; then hot press it at a pressure of 5 MPa and a temperature of 130°C for 4 hours, and finally cure it at 150°C for 5 hours to obtain a sandwich structure laminate.

[0039] Example 2

[0040] 1. Packing material preparation 1) Preparation of PTFE@SiO2: PTFE micro powder was activated by sodium naphthalene complex and introduced into the surface reaction sites. Then it was dispersed in an ethanol / water mixed solvent and treated with KH-560 at 70°C under pH 5 to graft an epoxy silane layer. Then, using tetraethyl orthosilicate (TEOS) as a precursor and ammonia water as a catalyst, PTFE@SiO2 with epoxy groups on the surface was prepared by sol-gel method.

[0041] 2) Preparation of modified SAPO-34: After removing agglomerates by ball milling, SAPO-34 molecular sieves are dispersed in an ethanol / water mixed solvent and treated with KH-560 at 70°C to introduce the epoxy reaction end, thus obtaining silane-modified SAPO-34.

[0042] 2. Fiber Modification 4) First, basalt fiber (BF) is coated with SiO2 sol-gel to obtain SiO2@BF intermediate fiber cloth; 5) The hexagonal boron nitride (h-BN) sheets are then coated with polydopamine (PDA) biomimetic self-polymerization to obtain h-BN@PDA powder; 6) Immerse BF@SiO2 in a slurry containing h-BN@PDA and pull it to load h-BN@PDA sheets onto the surface of BF@SiO2. Then treat it in an ethanol solution containing KH-560 at 70°C, and then wash and dry it to obtain BF@SiO2@(h-BN@PDA) fiber cloth, abbreviated as BF@SiO2@BN.

[0043] 3. Preparation of prepreg: 1) Outer layer semi-cured sheet: 3 wt% PTFE@SiO2 is uniformly dispersed in epoxy resin, BF@SiO2@BN fiber cloth is impregnated by hand lay-up, and dried at 0.6 m / min and 90℃ to obtain an outer layer semi-cured sheet with a resin content of 40 wt% BF@SiO2@BN and PTFE@SiO2 / EP composite. 2) Inner layer semi-cured sheet: The prepared 1wt% slightly silane-modified SAPO-34 was uniformly dispersed in epoxy resin, impregnated with BF@SiO2@BN fiber cloth, and dried at 90℃ after roller pressing speed of 1.0 m / min. The inner layer semi-cured sheet with a glue content of 42wt% was obtained after composite of BF@SiO2@BN and modified SAPO-34 / EP. 4. Laminate preparation 3) Lay out the outer semi-cured sheet, the inner semi-cured sheet, and the outer semi-cured sheet in sequence in the mold; 4) Place the laid-out semi-cured sheet on a hot press platform and keep it at a pressure of 0.5 MPa and a temperature of 85°C for 1.5 hours; then hot press it at a pressure of 5 MPa and a temperature of 130°C for 4 hours, and finally cure it at 150°C for 5 hours to obtain a sandwich structure laminate.

[0044] Comparative Example 1 1. Packing material preparation 1) Preparation of PTFE@SiO2: PTFE micro powder was activated by sodium naphthalene complex and introduced into the surface reaction sites. Then it was dispersed in an ethanol / water mixed solvent and treated with KH-560 at 70°C under pH 5 to graft an epoxy silane layer. Then, using tetraethyl orthosilicate (TEOS) as a precursor and ammonia water as a catalyst, PTFE@SiO2 with epoxy groups on the surface was prepared by sol-gel method.

[0045] 2) Preparation of modified SAPO-34: After removing agglomerates by ball milling, SAPO-34 molecular sieves are dispersed in an ethanol / water mixed solvent and treated with KH-560 at 70°C to introduce the epoxy reaction end, thus obtaining silane-modified SAPO-34.

[0046] 2. Fiber Modification 1) Basalt fiber (BF) is first coated with SiO2 sol-gel to obtain SiO2@BF intermediate fiber cloth; 2) The hexagonal boron nitride (h-BN) sheets are then coated with polydopamine (PDA) biomimetic self-polymerization to obtain h-BN@PDA powder; 3) Immerse BF@SiO2 in a slurry containing h-BN@PDA and pull it to load h-BN@PDA sheets onto the surface of BF@SiO2. Then treat it in an ethanol solution containing KH-560 at 70°C, and then wash and dry it to obtain BF@SiO2@(h-BN@PDA) fiber cloth, abbreviated as BF@SiO2@BN.

[0047] 3. Preparation of prepreg: 4 wt% PTFE@SiO2 and 1.5 wt% slightly silane-modified SAPO-34 were uniformly dispersed in epoxy resin. BF@SiO2@BN fiber cloth was impregnated by hand lay-up, and the mixture was dried at 90°C after rolling at a speed of 0.6 m / min. This yielded a semi-cured sheet with a resin content of 40 wt% BF@SiO2@BN / modified SAPO-34 / PTFE@SiO2 / EP composite.

[0048] 4. Laminate preparation 1) Lay the prepreg layer by layer in the mold; 5) Place the laid-out semi-cured sheet on a hot press platform and keep it at a pressure of 0.5 MPa and a temperature of 85°C for 1.5 hours; then hot press it at a pressure of 5 MPa and a temperature of 130°C for 4 hours, and finally cure it at 150°C for 5 hours to obtain a sandwich structure laminate.

[0049] Comparative Example 2 1. Packing material preparation Unseparated PTFE and SAPO-34 molecular sieve were dispersed in water, and agglomerates were removed by ultrasonic dispersion, drying, and ball milling to obtain PTFE powder and SAPO-34 powder.

[0050] 2. Preparation of prepreg: 4 wt% PTFE and 1.5 wt% SAPO-34 were uniformly dispersed in epoxy resin, and BF fiber cloth was impregnated by hand lay-up. After being rolled at a speed of 0.6 m / min and dried at 90°C, an outer semi-cured sheet with a resin content of 40 wt% BF and SAPO-34 / PTFE / EP composite was obtained.

[0051] 4. Laminate preparation 3) Lay the prepreg layer by layer in the mold; 6) Place the laid-out semi-cured sheet on a hot press platform and keep it at a pressure of 0.5 MPa and a temperature of 85°C for 1.5 hours; then hot press it at a pressure of 5 MPa and a temperature of 130°C for 4 hours, and finally cure it at 150°C for 5 hours to obtain a sandwich structure laminate.

[0052] Table of Implementation / Comparison Plans

[0053] Table performance results comparison

[0054] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sandwich-structured basalt laminate with synergistic hydrophobic flashover resistance and insulating and flame-retardant properties, characterized in that, It comprises two hydrophobic anti-flashover outer layers and an insulating and flame-retardant inner layer sandwiched between the two hydrophobic anti-flashover outer layers; both the hydrophobic anti-flashover outer layer and the insulating and flame-retardant inner layer use modified basalt fiber cloth as a reinforcing skeleton and epoxy resin as a matrix; the hydrophobic anti-flashover outer layer matrix is ​​compounded with hydrophobic anti-flashover core-shell functional filler, and the insulating and flame-retardant inner layer matrix is ​​compounded with high-temperature ceramic flame-retardant insulating molecular sieve filler.

2. The sandwich-structured basalt laminate with hydrophobic anti-flashover and insulating flame retardant synergy as described in claim 1, characterized in that, Based on the total thickness of the laminate, the hydrophobic and anti-flashover outer layer accounts for 10%-15% of the thickness, while the insulating and flame-retardant inner layer accounts for 85%-90%.

3. The basalt laminate with a sandwich structure that combines hydrophobicity, anti-flashover, insulation, and flame retardancy as described in claim 1, characterized in that, The hydrophobic and antifouling core-shell functional filler is a PTFE@SiO2 core-shell filler. The PTFE micro powder has a particle size of 0.5-3μm, and the SiO2 shell is grafted with epoxy reactive groups through a silane coupling agent. The amount of the PTFE@SiO2 core-shell filler added to the hydrophobic and antifouling outer epoxy resin matrix is ​​3-5wt%. The silane coupling agent is γ-glycidoxypropyltrimethoxysilane KH-560.

4. The basalt laminate with a sandwich structure combining hydrophobicity, anti-flashover, insulation, and flame retardancy as described in claim 1, characterized in that, The high-temperature ceramic flame-retardant insulating molecular sieve filler is a SAPO-34 molecular sieve modified with a silane coupling agent. The amount of modified SAPO-34 added to the insulating and flame-retardant inner epoxy resin matrix is ​​1-2 wt%. The surface of the SAPO-34 molecular sieve is grafted with epoxy reactive end groups.

5. The sandwich structure basalt laminate with hydrophobic anti-flashover and insulating flame retardant synergy as described in claim 1, characterized in that, The modified basalt fiber cloth is prepared as follows: the basalt fiber cloth is first deposited with SiO2 by sol-gel method to obtain SiO2@BF intermediate fiber cloth; hexagonal boron nitride is coated with polydopamine biomimetic self-polymerization to obtain h-BN@PDA powder; SiO2@BF is immersed in h-BN@PDA slurry to impregnate and pull up the loaded boron nitride sheets, and then treated with KH-560 ethanol solution, washed and dried to obtain BF@SiO2@BN modified basalt fiber cloth.

6. A method for preparing a sandwich-structured basalt laminate with synergistic hydrophobic flashover resistance and insulating flame retardancy according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Filler preparation: Prepare PTFE@SiO2 core-shell filler with surface-grafted epoxy groups, and at the same time prepare silane-modified SAPO-34 molecular sieve filler. S2. Fiber modification: Basalt fiber cloth is modified to obtain BF@SiO2@BN modified fiber cloth; S3. Preparation of semi-cured sheets: PTFE@SiO2 core-shell filler is dispersed in epoxy resin, impregnated with BF@SiO2@BN modified fiber cloth, and rolled and dried to prepare the outer semi-cured sheet; modified SAPO-34 molecular sieve is dispersed in epoxy resin, impregnated with BF@SiO2@BN modified fiber cloth, and rolled and dried to prepare the inner semi-cured sheet. S4. Hot-press co-curing molding: The materials are stacked in the following order: hydrophobic anti-flashover outer semi-cured sheet - insulating flame-retardant inner semi-cured sheet - hydrophobic anti-flashover outer semi-cured sheet. The materials are then hot-pressed and cured in sections with controlled temperature and pressure to obtain a sandwich structure basalt laminate.

7. The preparation method according to claim 6, characterized in that, The preparation process of PTFE@SiO2 core-shell filler in S1 is as follows: PTFE micro powder is activated with sodium naphthalene complex, dispersed in an ethanol-water mixed solvent, pH controlled at 4-5, grafted with KH-560 at 60-70℃, and then PTFE@SiO2 with epoxy groups on the surface is obtained by using tetraethyl orthosilicate (TEOS) as a precursor and ammonia water as a catalyst for sol-gel reaction.

8. The preparation method according to claim 6, characterized in that, The modified SAPO-34 molecular sieve preparation process in step S1 is as follows: SAPO-34 molecular sieve is ball-milled to break up agglomerates, dispersed in an ethanol-water mixed solvent, and then grafted with KH-560 at 60-70℃ to introduce epoxy reaction ends, thereby obtaining silane-modified SAPO-34.

9. The preparation method according to claim 6, characterized in that, The prepreg preparation parameters in step S3 are: rolling speed 0.3-2.0 m / min, drying temperature 80-120℃, and adhesive content of the prepreg controlled at 35-45 wt%.

10. The preparation method according to claim 6, characterized in that, Step S4 Hot-press co-curing segmented process: First step, 80-90℃, heat preservation for 1-2 hours, pressure 0-1MPa; Second step, hot pressing at 130-150℃ for 2-4 hours, pressure 2-6MPa; Third step, post-curing at 150-160℃ for 4-6 hours, to complete curing and obtain the finished laminate.

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