Flexible siloxane-based nanofiber fireproof insulation wrapping tape, and preparation method and application thereof

Abstract

This invention discloses a method for preparing a flexible silica-oxygen nanofiber fireproof and insulating winding tape, comprising the following steps: 1) adding raw materials such as silica, alumina, silicon carbide, titanium dioxide, amorphous silicon, methyl MQ silicone resin, polyacrylonitrile pre-oxidized fiber, and glass fiber sequentially into silica sol and mixing them evenly to obtain a spinning slurry; 2) electrospinning the spinning slurry to obtain a primary floc blank; 3) naturally drying the primary floc blank and then subjecting it to staged heat treatment and cooling to form a composite floc; 4) stacking the composite floc and then sequentially performing hot pressing and sewing treatments to obtain the flexible silica-oxygen nanofiber fireproof and insulating winding tape. The flexible silica-oxygen nanofiber fireproof insulating winding tape prepared by this invention can be folded arbitrarily after being frozen at -80℃ for 24 hours, and has a linear shrinkage rate of ≤1% after being calcined at 1200℃ for 30 minutes. It also exhibits no discoloration and no smoke. Furthermore, it has excellent thermal insulation properties, with a room temperature thermal conductivity of ≤0.032W / (m·K) and a thermal conductivity of ≤0.035W / (m·K) at 400℃, making it suitable for applications in fireproofing, heat insulation, and insulation fields.

Description

Technical Field

[0001] This invention belongs to the technical field of flexible fireproof and insulating materials, specifically relating to a flexible silica-oxygen nanofiber fireproof and insulating winding tape and its preparation method at room temperature and pressure, low cost, and scalable scale. It also relates to the application of this flexible silica-oxygen nanofiber fireproof and insulating winding tape in the fields of fireproofing, heat insulation, and insulation. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In the field of cable fire protection and insulation, winding materials are flexible strip-shaped products that are wrapped around the cable core using wrapping or spiral winding methods. Their core function is to construct a stable physical isolation layer within the cable structure, preventing current leakage to ensure electrical safety and delaying or blocking the spread of flames, ensuring that the line can maintain normal operation for a certain period even under fire conditions. Existing winding materials, such as mica tape, ceramic fiber tape, and glass fiber tape, are widely used in fields with strict requirements for fire resistance and insulation, such as construction, transportation, metallurgy, and shipbuilding. However, existing winding materials still have the following technical shortcomings: (1) Large thickness and large space occupation: The thickness of traditional mica tape is generally 0.5 to 1.0 mm, ceramic fiber tape is 1.0 to 3.0 mm, and glass fiber tape is 0.8 to 2.0 mm. For precision electrical equipment, compact wire harnesses or cable joints in narrow spaces, the excessive thickness is difficult to meet the installation space requirements. (2) Poor flexibility and difficulty in tight wrapping: Existing winding tapes are generally rigid, and the minimum bending radius is usually more than 10 times the tape thickness, making it impossible to achieve 360° winding or small curvature winding; when wrapping irregular parts such as cable joints and busbar bends, wrinkles, curling edges or even cracks are likely to occur, resulting in discontinuous protective layer. (3) Low upper limit of fire resistance temperature, easy to fail at high temperature: The long-term service temperature of mica tape is generally no more than 650℃, and that of ceramic fiber tape is about 1000℃; at higher temperatures (such as 1000~1200℃), the tape will shrink, pulverize, crack, or even melt or smoke, which cannot meet the needs of modern industry for ultra-high temperature fire resistance. (4) Low thermal insulation efficiency, requiring multiple layers of wrapping: Traditional materials have high thermal conductivity (mica tape 0.050~0.080W / (m·K), ceramic fiber tape 0.060~0.090W / (m·K)). In order to achieve the required fireproof and heat insulation effect, multiple layers of wrapping are often required, which increases the thickness and construction difficulty and cost. (5) Insufficient insulation performance or rapid decay: The insulation resistance of some tapes (such as fiberglass tapes) drops sharply at high temperatures; the insulation performance of some materials deteriorates after absorbing moisture, and they cannot meet the long-term insulation requirements of high-voltage cables (≥10kV); (6) Severe dust pollution: Mica tape and ceramic fiber tape are prone to shedding powder and slag due to friction or bending during use. The fine mica flakes falling from the mica tape are irritating to the respiratory tract of construction workers, and the dust from the ceramic fiber tape can cause skin itching. They are not suitable for clean environments. Therefore, there is an urgent need to develop a fireproof and insulating wrapping tape that is ultra-thin, highly flexible, has an ultra-wide temperature range of fire resistance, low thermal conductivity, high insulation, is dust-free, and can be mass-produced. Summary of the Invention

[0004] In view of the shortcomings of existing thermal insulation materials, such as narrow temperature range, easy attenuation at high temperature, easy pulverization, poor flexibility, and high manufacturing cost, the main purpose of this invention is to provide a flexible silicone nanofiber fireproof insulating wrapping tape that is ultra-thin, highly flexible, fire-resistant with an ultra-wide temperature range, low thermal conductivity, high insulation, dust-free, and mass-producible. The purpose of this invention is to provide a method for preparing a flexible silica-oxygen nanofiber fireproof and insulating winding tape that is room temperature and pressure controlled, has few process steps, low cost, and high efficiency.

[0005] The present invention also aims to provide an application of flexible silica-oxygen nanofiber fireproof insulating winding tape in the fields of fireproofing, heat insulation, and insulation.

[0006] The objective of this invention is achieved through the following technical solution: A method for preparing a flexible silica-oxygenated nanofiber fireproof and insulating winding tape includes the following steps: 1) Add the raw materials silica, alumina, silicon carbide, titanium dioxide, amorphous silicon, methyl MQ silicone resin, polyacrylonitrile pre-oxidized fiber and glass fiber to the silica sol in sequence, mix evenly to obtain spinning slurry; 2) Electrospin the spinning slurry obtained in step 1) to obtain a primary floc blank; 3) After the initial floc blank is naturally dried, it is subjected to staged heat treatment and cooled to form a composite floc core layer; 4) The glass fiber cloth is stacked with the composite wadding core layer obtained in step 3), and then hot-pressed and sewn in sequence to obtain the flexible silicone nanofiber fireproof and insulating winding tape.

[0007] In some specific embodiments, the mass ratio of silicon dioxide, aluminum oxide, silicon carbide, titanium dioxide, amorphous silicon, methyl MQ silicone resin, polyacrylonitrile pre-oxidized fiber and glass fiber in step 1) is (70-85): (5-12): (1-4): (1-3): (1-5): (0.5-3): (2-6): (2-8).

[0008] In some specific embodiments, the silica has a particle size ≤100μm, and the polyacrylonitrile pre-oxidized fiber has a density ≥1.30g / cm³. 3 .

[0009] In some specific embodiments, the electrospinning process parameters in step 2) are: voltage 12-30kV, receiving distance 10-25cm, and flow rate 0.5-1.5mL / h.

[0010] In some specific embodiments, the staged heat treatment described in step 3) is specifically a three-stage heating process, specifically holding at 300-500℃ for 0.5-2h, holding at 600-800℃ for 0.5-2h, and holding at 1000-1200℃ for 1-3h.

[0011] The three-stage heating process is as follows: The first stage involves holding the material at 300–500℃ for 0.5–2 hours. During this stage, the residual solvent completely evaporates; the pre-oxidized polyacrylonitrile fiber begins to cyclize and dehydrogenate, forming a heat-resistant trapezoidal structure; the organic groups in the methyl MQ silicone resin partially decompose, but its Si-O-Si cage-like framework remains, serving as a temporary adhesive; the hydroxyl groups on the surface of powders such as silica and alumina undergo a condensation reaction, forming initial inorganic interfacial bonds. The second stage involves holding the fiber at 600–800℃ for 0.5–2 hours. During this stage, the pre-oxidized polyacrylonitrile fiber is further carbonized, transforming into carbon fiber with a graphite microcrystalline structure, which is in situ interwoven into the silica skeleton. The silica particles begin to form sintering necks, and the skeleton gradually becomes denser. The surface of the glass fiber softens and wets and diffuses with the surrounding silica particles. The alumina particles act as rigid pinning points, inhibiting the migration of silica grain boundaries and improving the high-temperature creep resistance of the matrix.

[0012] The third stage involves heat preservation at 1000–1200℃ for 1–3 hours: During this stage, amorphous silicon is oxidized to silicon dioxide, which simultaneously consumes free oxygen inside the felt body, protecting the carbon fibers from oxidation and ablation; titanium dioxide reflects infrared radiation, significantly inhibiting high-temperature radiation heat transfer; a dense SiO2 protective film forms on the surface of silicon carbide particles, enhancing their resistance to heat radiation; interdiffusion occurs between the atoms at the interfaces of each component, forming a gradient transition layer with chemical bonds, which firmly bonds the fiber to the matrix.

[0013] In summary, the prepared nascent floc blanks undergo a segmented heat treatment process, ensuring that they do not shrink or pulverize at 1200℃, while the carbon fibers retained in situ impart high-temperature flexibility to the product.

[0014] The electrospinning, atmospheric pressure drying, and segmented heat treatment process requires no supercritical equipment, no organic solvent replacement, and no complex aging steps, enabling large-scale continuous production. The overall cost is reduced by more than 50% compared to traditional aerogel felts.

[0015] In some specific embodiments, the ambient humidity during natural drying in step 3) is ≤ 80%. The three-dimensional fiber network formed by electrospinning glass fiber, polyacrylonitrile pre-oxidized fiber, etc. has sufficient rigid intersections to resist capillary pressure during solvent evaporation. Therefore, it can maintain high porosity without supercritical drying. The linear shrinkage rate of the product after drying is ≤ 5%, and the porosity is maintained above 95%.

[0016] In some specific embodiments, the layering in step 4) specifically refers to: selecting "single-sided composite" (one layer of glass fiber cloth + one layer of composite wadding core layer) or "double-sided composite" (glass fiber cloth sandwiched between two layers of composite wadding core layer, or composite wadding core layer sandwiched between two layers of glass fiber cloth) as needed. The hot pressing described in step 4) specifically involves feeding the laminated composite material into a hot pressing roller composite device. The temperature of the hot pressing roller is controlled at 150–200°C, the pressure at 0.2–1.0 MPa, and the roller speed at 0.5–2 m / min. Under the combined action of heat and pressure, the silica nanoparticles on the surface of the composite flocculent core layer undergo a condensation reaction with the silica sol coating on the surface of the glass fiber cloth, forming a strong chemical bond. At the same time, the fiber network is moderately compressed, achieving preliminary bonding without damaging the internal porous structure. The pre-composite strip has a uniform thickness, without delamination or wrinkles.

[0017] The sewing process described in step 4) specifically involves sewing the composite layer obtained after hot pressing with high-temperature resistant glass fiber sewing thread to form a strong composite strip blank. The sewing thread used is high-temperature resistant glass fiber sewing thread (long-term operating temperature ≥550℃, short-term withstand 800℃), with a diameter of 0.2–0.5 mm. Industrial sewing machines are used for sewing, with parallel sewing along the length of the strip, employing single-row, double-row, or zigzag sewing methods. The stitch length is set to 5–15 mm, and the thread tension is moderate (avoiding excessive tightness that damages the fiber layer or excessive looseness that causes delamination). In a specific embodiment, the high-temperature resistant glass fiber sewing thread used has a diameter of 0.3 mm, and the sewing method is single-row sewing along the length of the strip, with a stitch length set to 10 mm. After sewing, the core layer and glass fiber cloth in the composite layer are mechanically locked together. Even when the chemical bonding of the pre-composite layer under high temperature heat pressing is partially weakened due to extreme conditions, the sewing thread still provides reliable secondary fixation, ensuring that the strip does not separate in bending, winding, or vibration environments.

[0018] In some specific embodiments, the glass fiber cloth in step 4) is further pretreated by heat treatment and impregnation to enhance its bonding strength with the composite floc core layer. Specifically, the glass fiber cloth is heat-treated in an oven at 250-350°C for 20-40 minutes to remove surface wetting agent and organic impurities. Then, the heat-treated glass fiber cloth is impregnated in dilute silica sol (solid content 5%-10%) for 1-5 minutes. After removal, it is dried at 80-120°C to form a uniform silica sol coating on the surface of the glass fiber cloth. This coating can covalently bond with the siloxy network in the composite floc core layer during subsequent hot pressing and lamination, significantly improving the interfacial bonding strength.

[0019] In some specific embodiments, the sewn wide strip (generally 300-1000mm wide) is placed on a precision slitting machine and longitudinally slit using a disc cutter or ultrasonic cutter. The slitting width is set to 10-200mm according to application requirements, with a width tolerance of ±1mm, resulting in clean cuts without burrs or delamination. After passing inspection, the slit strip is wound into standard rolls by a winding machine, with an inner diameter of 76mm (or customized according to customer requirements), and each roll is 5-50m long. The winding tension is controlled at 1-5N to avoid excessive tightness causing strip deformation or excessive looseness causing roll unraveling. Finally, the strip is packaged in moisture-proof aluminum foil bags or vacuum-sealed bags, and labeled with specifications, batch number, production date, and other information.

[0020] As part of the same inventive concept, the present invention also provides a flexible silica-oxygen nanofiber fireproof insulating winding tape prepared by the aforementioned preparation method.

[0021] As part of the same inventive concept, this invention also provides an application of the aforementioned flexible silica-oxygen nanofiber fireproof insulating winding tape in fields such as fireproofing, heat insulation, and insulation.

[0022] Compared with the prior art, the present invention has at least the following advantages: 1) The preparation method provided by this invention involves dissolving silica, alumina, silicon carbide, titanium dioxide, amorphous silicon, methyl MQ silicone resin, polyacrylonitrile pre-oxidized fiber, and glass fiber in silica sol. Then, a composite wadding core layer is obtained through electrospinning, atmospheric pressure and room temperature drying, and staged heat treatment. The composite wadding core layer is then laminated, hot-pressed, and sewn with glass fiber cloth. The resulting tape not only achieves stable use across the entire temperature range of -80℃ to 1200℃ but also exhibits excellent thermal insulation performance. Silica provides a phase-change-free main framework; glass fiber and polyacrylonitrile pre-oxidized fiber form an "elastic-rigid" hybrid network, physically locking the particles and providing high flexibility; amorphous silicon oxidizes at 1000–1200℃, consuming free oxygen and protecting the carbon fibers from ablation; alumina particles are uniformly dispersed in the silica framework, providing rigidity. The pinning points act as anchors, pinning the grain boundaries or fiber network nodes of silica particles, effectively hindering atomic diffusion and grain boundary migration, suppressing excessive sintering and shrinkage of the skeleton at 1000–1200℃, and significantly improving the high-temperature creep resistance of the composite material. The flexible silica-oxygen nanofiber fireproof and insulating winding tape prepared by this invention can be folded arbitrarily after freezing at -80℃ for 24 hours, and has a linear shrinkage rate of ≤1% after calcination at 1200℃ for 30 minutes, with no discoloration and no smoke. Combined with the reflection of infrared radiation by titanium dioxide, and the formation of a dense SiO2 protective film on the surface of silicon carbide particles at high temperatures, the high refractive index of which causes multiple scattering and absorption of infrared radiation, resulting in a room temperature thermal conductivity of ≤0.032W / (m·K) and a 400℃ thermal conductivity of ≤0.035W / (m·K) for the prepared flexible silica-oxygen nanofiber fireproof and insulating winding tape. 2) The provided flexible silicone nanofiber fireproof and insulating winding tape combines the composite wadding core layer with the glass fiber cloth through hot pressing and sewing, so that the core layer and the glass fiber cloth form a dual bonding interface of chemical bonding and mechanical locking, thereby obtaining an integrated composite structure that is free of delamination and powder shedding.

[0023] 3) This invention adopts an electrospinning, atmospheric pressure, room temperature drying, segmented heat treatment, layering, and hot pressing sewing process, which completely eliminates the need for supercritical drying or freeze drying equipment; the equipment investment only requires conventional ovens / drying rooms (<200,000 yuan), while the investment in traditional supercritical drying equipment is about 5 million to 10 million yuan; the process cycle is shortened to within 72 hours, and the overall cost is reduced by 50% to 60% compared with traditional thermal insulation materials.

[0024] 4) The flexible silica-oxygen nanofiber fireproof and insulating winding tape provided by this invention has excellent high-temperature fire resistance, with a combustion performance rating of GB 8624 A2 (smoke production characteristic S1, no burning drips, smoke toxicity T0). A 2.2mm thick tape, after being burned in a butane flame at 1200℃ for 30 minutes, shows no deformation or pulverization; and its volume resistivity is ≥1×10⁻⁶. 14 Ω·cm, breakdown voltage ≥20kV / mm.

[0025] 5) The flexible silica-oxygen nanofiber fireproof insulating wrapping tape of the present invention is made of inorganic raw materials, free of organic adhesives and halogen flame retardants. At the same time, it undergoes staged heat treatment to thoroughly remove organic residues (such as the decomposition of organic groups in methyl MQ silicone resin and the carbonization of polyacrylonitrile pre-oxidized fibers). The final product is mainly composed of oxides such as SiO2, Al2O3, SiC, and TiO2 and carbon fibers, all of which are inert and smokeless materials. The carbon fibers do not release harmful gases at high temperatures, and the absence of halogen flame retardants avoids the production of highly toxic gases such as dioxins and hydrogen halides during combustion. It is smokeless and odorless when burned at 1200°C, with a smoke toxicity level of ZA1, and has extremely high fire safety, making it safe for use in clean environments. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below.

[0027] Figure 1 This is a physical image of the flexible silica-oxygen nanofiber fireproof and insulating winding tape provided in Embodiment 1 of the present invention; Figure 2 This is a physical image of the flexible silica-oxygen nanofiber fireproof and insulating winding tape provided in Embodiment 1 of the present invention; Figure 3 This is a physical image of the flexible silica-oxygen nanofiber fireproof and insulating winding tape provided in Embodiment 1 of the present invention. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are merely descriptive and not limiting, and should not be construed as limiting the scope of protection of the present invention.

[0029] When a quantity, concentration, or other value or parameter is described as a range, preferred range, or preferred upper and lower limits, it should be understood that it is equivalent to specifically disclosing any range by combining any pair of upper or preferred values ​​with any lower or preferred values, regardless of whether the range is specifically disclosed. Unless otherwise stated, the numerical range values ​​listed herein include the endpoints of the range and all integers and fractions within that range.

[0030] Unless otherwise stated, all percentages, parts, ratios, etc. in this document are by weight.

[0031] The materials, methods, and embodiments described herein are exemplary and should not be construed as limiting unless otherwise stated.

[0032] A method for preparing a flexible silica-oxygenated nanofiber fireproof and insulating winding tape includes the following steps: 1) Add the raw materials silica, alumina, silicon carbide, titanium dioxide, amorphous silicon, methyl MQ silicone resin, polyacrylonitrile pre-oxidized fiber and glass fiber to the silica sol in sequence, mix evenly to obtain spinning slurry; 2) Electrospin the spinning slurry obtained in step 1) to obtain a primary floc blank; 3) After the initial floc blank is naturally dried, it is subjected to staged heat treatment, cooled and shaped to obtain composite floc; 4) Press and shape the composite flocculent sheet from step 3) to obtain the flexible silicone nanofiber fireproof and insulating winding tape.

[0033] In some specific embodiments, the mass ratio of silicon dioxide, aluminum oxide, silicon carbide, titanium dioxide, amorphous silicon, methyl MQ silicone resin, polyacrylonitrile pre-oxidized fiber and glass fiber in step 1) is (70-85): (5-12): (1-4): (1-3): (1-5): (0.5-3): (2-6): (2-8).

[0034] The silica comprises 70-85 parts by weight, for example, but not limited to 70, 75, 80, or 85 parts. As the main skeleton of the flexible silica-based nanofiber fire-retardant insulating winding tape, the silica has a particle size ≤100 μm; furthermore, the average particle size D50 of the silica is 10 nm to 100 μm, and the BET specific surface area is 50 to 500 m². 2 / g, SiO2 purity ≥98%; furthermore, in the following embodiments, the silica used was purchased from Hubei Huifu Nanomaterials Co., Ltd. (brand name HL-200), with an average particle size D50 of 80nm and a BET specific surface area of ​​200m². 2 / g, with a purity of 99.5%.

[0035] The alumina is present in 5-12 parts by weight, for example, but not limited to 5, 6, 7, 8, 9, 10, 11, or 12 parts. Alumina is mainly used to improve high-temperature strength and structural stability. Its average particle size D50 is 10 nm to 20 μm, Al2O3 purity is ≥98%, and its crystal form is α phase, γ phase, or a mixture thereof. The alumina in the following examples was purchased from Zhejiang Zhitai New Material Co., Ltd., and its crystal form is α-Al2O3, with an average particle size D50 of 100 nm and a purity of 99%.

[0036] The pre-oxidized polyacrylonitrile fiber comprises 2-6 parts by weight, for example, but not limited to 2, 3, 4, 5, or 6 parts. The pre-oxidized polyacrylonitrile fiber is primarily used to improve elasticity and toughness, and is converted into carbon fiber during heat treatment, with a bulk density of 1.30-1.45 g / cm³. 3 The monofilament diameter is 5-15 μm; the polyacrylonitrile pre-oxidized fiber (also known as pre-oxidized fiber) is further converted into carbon fiber after heat treatment at above 1000℃. The polyacrylonitrile pre-oxidized fiber used in the following examples was purchased from Jilin Carbon Valley Carbon Fiber Co., Ltd. (pre-oxidized fiber), and its bulk density is 1.38 g / cm³. 3 The diameter of the single filament is 10μm and the length is 3-10mm.

[0037] The amorphous silicon comprises 1-5 parts by weight, for example, but not limited to 1, 2, 3, 4, or 5 parts. It is mainly used to optimize pore structure and interfacial bonding, and as an oxygen getter during heat treatment. It is amorphous elemental silicon powder with an average particle size D50 of 20-500 nm, amorphousness ≥90%, and oxygen content ≤1%. After heat treatment at 1100℃, the amorphous silicon powder acts as an oxygen getter to control localized oxidation atmosphere. In the following embodiments, the amorphous silicon used was purchased from the Institute of Process Engineering, Chinese Academy of Sciences. It is amorphous elemental silicon powder with an average particle size D50 of 100 nm, amorphousness 95%, and oxygen content 0.5%.

[0038] The silica sol is 20-50 parts by weight and mainly serves as a silicon source precursor and interface binder. Its viscosity is 100-500 cP. It can be obtained through commercial purchase or prepared by existing methods. For example, the silica sol in the following embodiment can be prepared by the following method: under room temperature (25°C), tetraethyl orthosilicate and anhydrous ethanol are mixed at a volume ratio of 1:(2-4) and stirred evenly; deionized water (the molar amount of water is (3-6) times that of tetraethyl orthosilicate) and dilute nitric acid (pH=2~4) are added as catalysts to control the pH value of the system at 3~5. Stirring is continued for 2 hours to obtain a clear and transparent silica sol with a viscosity of 100~500 cP. The tetraethyl orthosilicate was purchased from Sinopharm Group, with a purity of 99.5% and a theoretical SiO2 content of 29%.

[0039] The titanium dioxide content is 1-3 parts by weight, for example, but not limited to 1 part, 2 parts, or 3 parts. Titanium dioxide is mainly used for infrared shielding and reducing high-temperature radiative heat transfer. Its average particle size D50 is 10-200 nm, TiO2 purity is ≥98%, and the crystal form is rutile or anatase. In the following examples, the titanium dioxide used was purchased from Jiangsu Panhua Chemical Co., Ltd. (brand name NR-950), which is rutile type, has an average particle size D50 of 30 nm, and a purity of 99%.

[0040] The silicon carbide content is 1-4 parts by weight, for example, but not limited to 1 part, 2 parts, 3 parts, and 4 parts. Silicon carbide is mainly used to enhance heat radiation resistance and high-temperature fire resistance. Its average particle size D50 is 0.1-50 μm, SiC purity is ≥95%, and the crystal form is α-SiC or β-SiC. In the following examples, the silicon carbide used was purchased from Shandong Jinmeng New Material Co., Ltd., and its crystal form is α-SiC, with an average particle size D50 of 1 μm and a purity of 98%.

[0041] The glass fiber comprises 2-8 parts by weight, for example, but not limited to 2, 3, 4, 5, 6, 7, or 8 parts. The glass fiber is primarily used to provide a flexible reinforcing skeleton; it is alkali-free glass fiber with a diameter of 5-20 μm and a length of 1-20 mm. In the following embodiments, the glass fiber was purchased from Taishan Glass Fiber Co., Ltd., and is alkali-free glass fiber with a diameter of 10 μm and a length of 3-15 mm. The methyl MQ silicone resin is present in an amount of 0.5-3 parts by weight, for example, but not limited to 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, and 3 parts. Methyl MQ silicone resin is mainly used to improve hydrophobicity and structural stability, with an M / Q ratio of 0.6-1.2 and a weight-average molecular weight of 2000-10000 Da. In the following examples, the methyl MQ silicone resin was purchased from Shandong Dayi Chemical Co., Ltd. (brand name DY-MQ101), with an M / Q ratio of 0.8 and a weight-average molecular weight of 4500 Da.

[0042] The fiberglass cloth is alkali-free fiberglass cloth with a thickness of 0.1-0.3mm and a mesh density of 5×5-20×20 threads / inch; the fiberglass sewing thread has a long-term service temperature of ≥550℃, can withstand 800℃ for short periods, and has a thread diameter of 0.2-0.5mm.

[0043] Example 1

[0044] This embodiment provides a method for preparing a flexible silica-oxygenated nanofiber fireproof and insulating winding tape, comprising the following steps: I. Raw material pretreatment Silica, alumina, silicon carbide, titanium dioxide, amorphous silicon, and methyl MQ silicone resin were ground and passed through a 200-mesh sieve. They were weighed according to the weight ratio and put into a mixer. The mixture was mechanically mixed at 200 r / min for 60 min to obtain a mixed powder. Glass fibers were cut to 6 mm and polyacrylonitrile pre-oxidized fibers were cut to 5 mm, and then dried in an oven at 100°C for 3 hours to remove surface-adsorbed moisture. The glass fiber cloth (0.2 mm thick, 10 × 10 strands / inch mesh) was heat-treated in a 300°C oven for 30 min to remove surface wetting agent and organic impurities. Then the heat-treated glass fiber cloth was immersed in silica sol (the silica sol prepared by the method in step two) for 2 min. After immersion, it was dried at 100°C for later use.

[0045] II. Preparation of silica sol At room temperature of 25°C, tetraethyl orthosilicate and anhydrous ethanol were mixed at a volume ratio of 1:3 and stirred for 10 min. Deionized water (the molar amount of water was 3 times that of tetraethyl orthosilicate) and dilute nitric acid (pH=3) were added to adjust the pH of the system to between 4 and 4. Stirring was continued for 3 h to obtain a clear and transparent silica sol with a viscosity of 250 cP. III. Preparation of spinning sizing agent By weight, the mixed powder obtained in step one (containing 82 parts silica, 7 parts alumina, 2 parts silicon carbide, 2 parts titanium dioxide, 0.5 parts amorphous silicon, and 0.5 parts methyl MQ silicone resin), 4 parts glass fiber, and 2 parts polyacrylonitrile pre-oxidized fiber are gradually added to the silica sol prepared in step two. At the same time, a high-speed disperser is turned on and dispersed at 3000 r / min for 2 hours until the powder and fiber are completely dispersed, without agglomeration or stratification, forming a homogeneous and flowable spinning slurry (solid content of 35 wt%). IV. Electrospinning The spinning slurry obtained in step three is injected into the liquid storage container of the electrospinning device. The process parameters are set as follows: applied voltage: 25kV; receiving distance: 15cm; slurry feed speed: 1mL / h; ambient temperature: 25℃; ambient relative humidity: 50%; electrospinning is started and spinning is carried out for 4 hours. A fluffy primary flocculent preform is deposited on the receiving device. V. Drying under normal pressure The nascent floc embryos obtained in step four were transferred to a fume hood and naturally dried at normal pressure and 25°C for 48 hours to obtain dried flocs.

[0046] VI. Segmented High-Temperature Heat Treatment The dried flocs obtained in step five were placed in a high-temperature electric furnace and heat-treated using a three-stage heating program: the temperature was increased to 400℃ at 3℃ / min and held for 1 hour; the temperature was then increased to 700℃ at 3℃ / min and held for 1 hour; and then the temperature was increased to 1100℃ at 3℃ / min and held for 1.5 hours. VII. Cooling, Slitting, and Shaping Turn off the heating power and allow the composite flocs after heat treatment in step six to cool naturally to room temperature with the furnace. Then, pre-cut the cooled composite flocs to the target size and remove the burrs on the edges to obtain a composite floc core layer with a thickness of 2 mm. 8. Layering, hot pressing, sewing, and cutting The composite wadding core layer cut in step seven is laminated with the pretreated glass fiber cloth in step 1) using a single-sided lamination process. The laminated composite material is then fed into a hot press roller lamination device, where the temperature of the hot press roller is controlled at 150℃, the pressure at 0.5MPa, and the roller speed at 1m / min. High-temperature resistant glass fiber sewing thread is then used to sew the hot-pressed composite material to obtain a 2.2mm thick flexible silicone nanofiber fireproof and insulating winding tape (flexible silicone nanofiber fireproof and insulating winding tape, as shown in...). Figure 1 (As shown).

[0047] Example 2

[0048] I. Raw material pretreatment Silica, alumina, silicon carbide, titanium dioxide, amorphous silicon, and methyl MQ silicone resin were ground and passed through a 200-mesh sieve. They were weighed according to the weight ratio and put into a mixer. The mixture was mechanically mixed at 200 r / min for 60 min to obtain a mixed powder. Glass fibers were cut to 6 mm and polyacrylonitrile pre-oxidized fibers were cut to 5 mm, and then dried in an oven at 100°C for 3 hours to remove surface-adsorbed moisture. The glass fiber cloth (0.2 mm thick, 10 × 10 strands / inch mesh) was heat-treated in a 300°C oven for 30 min to remove surface wetting agent and organic impurities. Then the heat-treated glass fiber cloth was immersed in silica sol (the silica sol prepared by the method in step two) for 2 min. After immersion, it was dried at 100°C for later use.

[0049] II. Preparation of silica sol At room temperature of 25°C, tetraethyl orthosilicate and anhydrous ethanol were mixed at a volume ratio of 1:3 and stirred for 10 min. Deionized water (the molar amount of water was 3 times that of tetraethyl orthosilicate) and dilute nitric acid (pH=3) were added to adjust the pH of the system to between 4 and 4. Stirring was continued for 3 h to obtain a clear and transparent silica sol with a viscosity of 250 cP. III. Preparation of spinning sizing agent By weight, the mixed powder obtained in step one (70 parts silica, 5 parts alumina, 1 part silicon carbide, 1 part titanium dioxide, 1 part amorphous silicon, and 1 part methyl MQ silicone resin), 2 parts glass fiber, and 2 parts polyacrylonitrile pre-oxidized fiber are gradually added to the silica sol prepared in step two. At the same time, a high-speed disperser is turned on and dispersed at 3000 r / min for 2 hours until the powder and fiber are completely dispersed, without agglomeration or stratification, forming a homogeneous and flowable spinning slurry (solid content of 35 wt%). IV. Electrospinning The spinning slurry obtained in step three is injected into the liquid storage container of the electrospinning device. The process parameters are set as follows: applied voltage: 12kV; receiving distance: 10cm; slurry feed speed: 0.5mL / h; ambient temperature: 25℃; ambient relative humidity: 50%; electrospinning is started and spinning is carried out for 4 hours. A fluffy primary flocculent preform is deposited on the receiving device. V. Drying under normal pressure The nascent floc embryos obtained in step four were transferred to a fume hood and naturally dried at normal pressure and 25°C for 48 hours to obtain dried flocs. VI. Segmented High-Temperature Heat Treatment The dried flocs obtained in step five were placed in a high-temperature electric furnace and heat-treated using a three-stage heating program: heating at 3℃ / min to 300℃ and holding for 0.5h; then heating at 3℃ / min to 600℃ and holding for 0.5h; and finally heating at 3℃ / min to 1000℃ and holding for 1h. VII. Cooling, Slitting, and Shaping Turn off the heating power and allow the wadding after heat treatment in step six to cool naturally to room temperature with the furnace. Then, pre-cut the cooled composite wadding to the target size of the porous heat insulation felt and remove the burrs on the edges to obtain a composite wadding core layer with a thickness of 2 mm. 8. Layering, hot pressing, sewing, and cutting The composite wadding core layer cut in step seven is laminated with the glass fiber cloth pretreated in step 1) using single-sided lamination. The laminated composite material is then fed into a hot press roller lamination device, where the temperature of the hot press roller is controlled at 150℃, the pressure at 0.5MPa, and the roller speed at 1m / min. Then, the hot-pressed composite material is sewn with high-temperature resistant glass fiber sewing thread to obtain a flexible silicone nanofiber fireproof and insulating winding tape with a thickness of 2.2mm.

[0050] Example 3

[0051] I. Raw material pretreatment Silica, alumina, silicon carbide, titanium dioxide, amorphous silicon, and methyl MQ silicone resin were ground and passed through a 200-mesh sieve. They were weighed according to the weight ratio and put into a mixer. The mixture was mechanically mixed at 200 r / min for 60 min to obtain a mixed powder. Glass fibers were cut to 6 mm and polyacrylonitrile pre-oxidized fibers were cut to 5 mm, and then dried in an oven at 100°C for 3 hours to remove surface-adsorbed moisture. The glass fiber cloth (0.2 mm thick, 10 × 10 strands / inch mesh) was heat-treated in a 300°C oven for 30 min to remove surface wetting agent and organic impurities. Then the heat-treated glass fiber cloth was immersed in silica sol (the silica sol prepared by the method in step two) for 2 min. After immersion, it was dried at 100°C for later use.

[0052] II. Preparation of silica sol At room temperature of 25°C, tetraethyl orthosilicate and anhydrous ethanol were mixed at a volume ratio of 1:3 and stirred for 10 min. Deionized water (the molar amount of water was 3 times that of tetraethyl orthosilicate) and dilute nitric acid (pH=3) were added to adjust the pH of the system to between 4 and 4. Stirring was continued for 3 h to obtain a clear and transparent silica sol with a viscosity of 250 cP. III. Preparation of spinning sizing agent By weight, the mixed powder obtained in step one (78 parts silica, 9 parts alumina, 2.5 parts silicon carbide, 2 parts titanium dioxide, 2 parts amorphous silicon, and 2 parts methyl MQ silicone resin), 5 parts glass fiber, and 4 parts polyacrylonitrile pre-oxidized fiber are gradually added to the silica sol prepared in step two. At the same time, a high-speed disperser is turned on and dispersed at 3000 r / min for 2 hours until the powder and fiber are completely dispersed, without agglomeration or stratification, forming a homogeneous and flowable spinning slurry (solid content of 35 wt%). IV. Electrospinning The spinning slurry obtained in step three is injected into the liquid storage container of the electrospinning device. The process parameters are set as follows: applied voltage: 25kV; receiving distance: 15cm; slurry feed speed: 1mL / h; ambient temperature: 25℃; ambient relative humidity: 50%; electrospinning is started and spinning is carried out for 4 hours. A fluffy primary flocculent preform is deposited on the receiving device. V. Drying under normal pressure The nascent floc embryos obtained in step four were transferred to a fume hood and naturally dried at normal pressure and 25°C for 48 hours to obtain dried flocs. VI. Segmented High-Temperature Heat Treatment The dried flocs obtained in step five were placed in a high-temperature electric furnace and heat-treated using a three-stage heating program: the temperature was increased to 450℃ at 3℃ / min and held for 1 hour; the temperature was then increased to 700℃ at 3℃ / min and held for 1 hour; and the temperature was then increased to 1100℃ at 3℃ / min and held for 1.5 hours. VII. Cooling, Slitting, and Shaping Turn off the heating power and allow the wadding after heat treatment in step six to cool naturally to room temperature with the furnace. Then, pre-cut the cooled composite wadding to the target size of the porous heat insulation felt and remove the burrs on the edges to obtain a composite wadding core layer with a thickness of 2 mm. 8. Layering, hot pressing, sewing, and cutting The composite wadding core layer cut in step seven is laminated with the glass fiber cloth pretreated in step 1) using single-sided lamination. The laminated composite material is then fed into a hot press roller lamination device, where the temperature of the hot press roller is controlled at 150℃, the pressure at 0.5MPa, and the roller speed at 1m / min. Then, the hot-pressed composite material is sewn with high-temperature resistant glass fiber sewing thread to obtain a flexible silicone nanofiber fireproof and insulating winding tape with a thickness of 2.2mm.

[0053] This application uses Example 1 as an example to conduct performance tests on the prepared 2.2mm flexible silica-oxygen nanofiber fireproof insulating wrapping tape. The main performance characteristics of the flexible silica-oxygen nanofiber fireproof insulating wrapping tape are demonstrated by testing the main properties of the sample. The main performance characteristics tested in this application include full temperature range testing (-80-1200℃), thermal conductivity, appearance morphology, pulverization, flexibility, high temperature resistance, and safety and environmental performance testing (unless otherwise specified, the following test methods are considered to be the latest test standards). Specifically: 1) Full-temperature range stability test; This application conducts a full-temperature-range stability test on the prepared flexible silica-oxygen nanofiber fireproof insulating winding tape, specifically: (a) Low temperature resistance Place the sample in a low temperature environment of -80℃ for 24 hours. After freezing, take it out, observe the changes in the appearance of the sample, and perform arbitrary folding operations to check for the occurrence of cracks. Performance indicators: The sample should show no cracks after being frozen at -80℃ for 24 hours and should be foldable arbitrarily; The test results show that the flexible silica-oxygen nanofiber fireproof and insulating wrapping tape of the present invention has no cracks after being frozen at -80℃ for 24 hours and can be folded arbitrarily. (b) High temperature resistance A sample with a thickness of 2.2 mm was taken and subjected to the following two high-temperature tests: (i) Static heat resistance test: The sample was placed in a high-temperature resistance furnace and calcined in a static air atmosphere at 1200℃ for 30 min. After cooling with the furnace, its linear shrinkage rate, discoloration and smoke release were evaluated. (ii) Flame burning test: A 1200℃ directional flame is generated using a butane torch and continuously burned vertically onto the sample surface for 30 minutes. The flame is evaluated to determine whether the sample melts, burns through, cracks, or peels off. The self-extinguishing time of the sample after the open flame is removed is also recorded.

[0054] Performance indicators: Static heat resistance test: linear shrinkage rate ≤1%, no discoloration, no smoke release; flame burning test: no melting, no burn-through, no cracking, no peeling, self-extinguishing time after removing the flame ≤5s.

[0055] Test results: After the above two tests, the flexible silicone nanofiber fireproof insulating wrapping tape of the present invention showed a dimensional shrinkage rate of <0.5% in the static heat resistance test, with no discoloration and no smoke; in the flame burning test, there was no melting, no burn-through, no cracking, and no peeling, and the flame extinguished itself when the fire was removed.

[0056] 2) Thermal conductivity test Testing standards: The room temperature thermal conductivity is tested in accordance with GB / T 10294 "Determination of steady-state thermal resistance and related properties of thermal insulation materials (protective hot plate method)" and the high temperature thermal conductivity is tested at 400℃, 800℃ and 1200℃ in accordance with GB / T 5990 "Test methods for thermal conductivity, specific heat capacity and thermal diffusivity of refractory materials (hot wire method)". The test results are as follows: the thermal conductivity of the flexible silicone nanofiber fireproof insulating winding tape of the present invention is ≤0.032W / (m·K) at room temperature; ≤0.035W / (m·K) at 400℃; ≤0.038W / (m·K) at 800℃; and ≤0.040W / (m·K) at 1200℃.

[0057] 3) Density test Testing standard: Bulk density test shall be conducted in accordance with GB / T 5480 "Test Methods for Mineral Wool and Its Products"; The test results show that the bulk density of the flexible silica-oxygen nanofiber fireproof insulating winding tape of this invention is 0.58 ± 0.02 g / cm³. 3 .

[0058] 4) Powdering test Test method: Fold the sample of the flocculent to be tested repeatedly along 180° 100 times, then use clean compressed air with a wind speed of 5 m / s to continuously blow the folded area for 10 minutes, and visually observe whether there is any dust falling off; take another sample, rub the sample surface back and forth 5 times with dry fingers, and check whether there is any powder stuck to the fingers.

[0059] Performance indicators: After the above folding and blowing treatment, no visible dust fell off the sample; there was no powdery feeling after rubbing with fingers, and no skin irritation upon contact.

[0060] The test results are as follows: The flexible silicone nanofiber fireproof and insulating wrapping tape of the present invention does not shed powder after being folded repeatedly at 180° 100 times; it does not shed powder when rubbed with fingers; and it does not shed dust when blown by high-pressure air (wind speed 5 m / s, 10 min).

[0061] 5) Flexibility test Testing standards: Bending performance is tested in accordance with GB / T 7690.4 "Test methods for reinforcing yarns - Part 4: Determination of stiffness"; compression resilience is tested in accordance with GB / T 8813 "Determination of compression properties of rigid foam plastics".

[0062] The test results show that the flexible silica-oxygen nanofiber fireproof and insulating winding tape of the present invention was wound 360° around a Φ=3 mm round bar without cracks.

[0063] 6) High-temperature thermal insulation performance test This application conducts high-temperature thermal insulation performance tests on the prepared flexible silica-oxygen nanofiber fireproof insulating winding tape, specifically: Test method: Take a sample with a thickness of 2.2 mm, place it in a hot plate device, establish a stable temperature field of 1200℃ on one side of the sample, and heat continuously for 30 min. During this period, use thermocouples to monitor the temperature of the unexposed side of the sample and the temperature rise curve in real time; simultaneously record the temperature of the cold side of the sample when it reaches steady state and the time required to reach the specified temperature rise (such as 100℃, 200℃).

[0064] Performance indicators: After being heated at 1200℃ on one side for 30 minutes, the temperature of the unexposed side is ≤350℃, and the temperature rise rate is ≤10℃ / min (first 10 minutes).

[0065] The test results are as follows: After the flexible silicone nanofiber fireproof insulating wrapping tape of the present invention is heated at 1200℃ on one side for 30 minutes, the temperature of the unexposed side is 320℃, and the average temperature rise rate in the first 10 minutes is 8.5℃ / min.

[0066] 7) Safety and environmental performance testing Testing standards: The combustion performance rating is assessed according to GB 8624 "Classification of Combustion Performance of Building Materials and Products"; the toxicity rating of the flue gas is determined according to GB / T 20285-2006 "Classification of Smoke Toxicity Hazards of Materials"; the halogen and sulfur content is tested according to EN 14582 "Characteristic Characterization of Waste - Determination of Halogen and Sulfur Content by Oxygen Combustion Method in Closed Systems"; and the heavy metal content is determined according to EPA 3050B (Acid Digestion Method for Sediments, Sludge and Soil).

[0067] The test results are as follows: The flexible silica-oxygen nanofiber fireproof insulating wrapping tape of the present invention has a combustion growth rate index FIGRA≤150W / s, a total heat release of ≤7.5MJ in 600s, no dripping, and a smoke toxicity level of ZA1; the combustion performance level is GB8624 A2 (smoke production characteristics s1 level, no combustion dripping, smoke toxicity t0 level); no halogens (Cl, Br <100 ppm) were detected, and there were no heavy metals such as lead, mercury, and cadmium.

[0068] 8) Electrical properties Testing standards: The volume resistivity of the tape is tested in accordance with GB / T 1410-2006 "Test methods for volume resistivity and surface resistivity of solid insulating materials"; the breakdown voltage of the tape is tested in accordance with GB / T 1408.1-2016 "Test methods for electrical strength of insulating materials - Part 1: Tests at power frequency".

[0069] Test results: The volume resistivity of the flexible silica-oxygen nanofiber fireproof insulating winding tape of the present invention is ≥1×10⁻⁶. 14 Ω·cm, breakdown voltage ≥20kV / mm.

[0070] 9) Mechanical properties Testing Standards: The tensile strength of the strip is tested in accordance with GB / T 3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break (Strip Method)"; the interfacial peel strength between the composite wadding core layer and the glass fiber cloth in the strip is tested in accordance with GB / T 1457-2022 "Test Method for Roller Peel Strength of Sandwich Structures".

[0071] Test results: The tensile strength of the flexible silicone nanofiber fireproof insulating wrapping tape of the present invention is ≥120N / 50mm, and the interfacial peel strength is ≥2.5N / cm.

[0072] Meanwhile, the flexible silica-oxygen nanofiber fireproof insulating wrapping tape provided in this application has been applied to the isolated mineral-insulated cables of Chongqing Pigeon Brand Wire & Cable Co., Ltd., and after testing, it has excellent volume resistivity, insulation, flame retardancy and fire resistance.

[0073] Comparative Example 1 This comparative example provides a method for preparing a flexible silica-oxygen nanofiber fireproof and insulating winding tape. Its components and proportions are basically the same as those in Example 1, except that it does not contain polyacrylonitrile pre-oxidized fibers, but instead uses an equal amount of glass fibers to replace the polyacrylonitrile pre-oxidized fibers. Its process steps and parameters are the same as those in the example. This application conducts performance tests on the flexible silica-oxygen nanofiber fireproof and insulating winding tape prepared therefrom, and the main performance differences are as follows: The flexible silica-oxygen nanofiber fireproof insulating winding tape of this comparative example is hard and brittle, and it breaks when wound around a Φ=3mm round bar, making it impossible to wind 360°; and after the sample is burned in a butane flame (1200℃) for 30 minutes, obvious slag appears at the edge of the sample, and the shrinkage rate reaches 6%.

[0074] Comparative Example 2 This comparative example provides a method for preparing a flexible silica-oxygen nanofiber fireproof and insulating winding tape. Its components and proportions are basically the same as those in Example 1, except that it does not contain amorphous silicon, but instead uses an equal amount of silicon dioxide to replace amorphous silicon. Its process steps and parameters are the same as those in the example. This application conducts performance tests on the flexible silica-oxygen nanofiber fireproof and insulating winding tape prepared therefrom, and the main performance differences are as follows: In this comparative example, after the flexible silica-oxygen nanofiber fireproof insulating wrapping tape was burned in a butane flame (1200℃) for 30 minutes, the carbon fibers in the composite flocculent core layer of the tape oxidized and disappeared, and the tape as a whole pulverized, smoked, and lost its structural integrity.

[0075] Comparative Example 3 This comparative example provides a method for preparing a flexible silica-oxygen nanofiber fireproof and insulating winding tape, the composition and ratio of which are the same as in Example 1; the process steps and process parameters are basically the same, the difference being the use of a one-step sintering process, specifically: The dried flocs obtained in step five are heated to 1100℃ at a rate of 10℃ / min and kept at that temperature for 1.5h. During the preparation process, when the dried flocs are heated to about 700°C, a popping sound is heard. After cooling, they are fragmented and cannot be obtained as complete flocs.

[0076] Comparative Example 4 This comparative example provides a method for preparing a flexible silica-oxygen nanofiber fireproof and insulating winding tape, the composition and ratio of which are the same as those in Example 1; the process steps and process parameters are basically the same, the difference being that in the staged heat treatment process, the third stage temperature is 900℃ and held for 1.5h. This application conducts performance tests on the flexible silica-oxygen nanofiber fireproof and insulating winding tape prepared therefrom, and the main performance differences are as follows: The flexible silica-oxygenated nanofiber fireproof insulating winding tape of this comparative example has a room temperature thermal conductivity of 0.039 W / (m·K) and a thermal conductivity of 0.045 W / (m·K) at 400℃. After calcination at 1200℃ for 30 min, the linear shrinkage rate reached 4.2%, and the sample turned yellow and emitted smoke. After calcination in a butane flame at 1200℃ for 30 min, the edges powdered, the carbon fibers oxidized, and the structure failed; the volume resistivity decreased to 8 × 10⁻⁶. 12The breakdown voltage dropped to 12kV / mm in Ω·cm; microcracks appeared when the product was wound around a Φ=3mm round bar. It is evident that the 900℃ heat treatment resulted in insufficient oxidation of amorphous silicon, incomplete passivation film on the SiC surface, and weak interfacial bonding, leading to a comprehensive deterioration of the product's high-temperature resistance, thermal insulation, electrical insulation, and flexibility.

[0077] Comparative Example 5 This comparative example provides a method for preparing a flexible silica-oxygen nanofiber fireproof and insulating winding tape, the composition and ratio of which are the same as in Example 1; the process steps and process parameters are basically the same, the difference being that the ambient humidity for drying at normal pressure is 85%, specifically: In the preparation method of this comparative example, the drying time of the initial floc blank was extended to 96 hours, the floc surface turned white due to salt precipitation, and the mechanical strength decreased by about 30%; the volume resistivity of the strip obtained after subsequent hot pressing and sewing decreased to 10. 11 Ω·cm.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for preparing a flexible silica-oxygenated nanofiber fireproof insulating winding tape, characterized in that, Includes the following steps: 1) Add the raw materials silica, alumina, silicon carbide, titanium dioxide, amorphous silicon, methyl MQ silicone resin, polyacrylonitrile pre-oxidized fiber and glass fiber to the silica sol in sequence, mix evenly to obtain spinning slurry; 2) Electrospin the spinning slurry obtained in step 1) to obtain a primary floc blank; 3) After the initial floc blank is naturally dried, it is subjected to staged heat treatment and cooled to form a composite floc core layer. 4) The glass fiber cloth is stacked with the composite wadding core layer obtained in step 3), and then hot-pressed and sewn in sequence to obtain the flexible silicone nanofiber fireproof and insulating winding tape.

2. The method for preparing the flexible silica-oxygenated nanofiber fireproof insulating winding tape according to claim 1, characterized in that, It also includes sequentially heat-treating and impregnating the glass fiber cloth described in step 4).

3. The method for preparing the flexible silica-oxygenated nanofiber fireproof insulating winding tape according to claim 2, characterized in that, The heat treatment specifically involves heat treatment at 250–350°C for 20–40 minutes; the impregnation treatment specifically involves immersing the heat-treated glass fiber cloth in dilute silica sol for 1–5 minutes, and then drying it at 80–120°C.

4. The method for preparing the flexible silica-oxygenated nanofiber fireproof insulating winding tape according to claim 1, characterized in that, The mass ratio of silicon dioxide, aluminum oxide, silicon carbide, titanium dioxide, amorphous silicon, methyl MQ silicone resin, polyacrylonitrile pre-oxidized fiber and glass fiber in step 1) is (70-85): (5-12): (1-4): (1-3): (1-5): (0.5-3): (2-6): (2-8).

5. The method for preparing the flexible silica-oxygenated nanofiber fireproof insulating winding tape according to claim 1, characterized in that, The electrospinning process parameters described in step 2) are: voltage 12-30kV, receiving distance 10-25cm, and flow rate 0.5-1.5mL / h.

6. The method for preparing the flexible silica-oxygenated nanofiber fireproof insulating winding tape according to claim 1, characterized in that, The phased heat treatment described in step 3) is specifically a three-stage heating process: holding at 300-500℃ for 0.5-2 hours, holding at 600-800℃ for 0.5-2 hours, and holding at 1000-1200℃ for 1-3 hours.

7. The method for preparing the flexible silica-oxygenated nanofiber fireproof insulating winding tape according to claim 1, characterized in that, In step 3), the ambient humidity during natural drying is ≤ 80%.

8. The method for preparing the flexible silica-oxygenated nanofiber fireproof insulating winding tape according to claim 1, characterized in that, The hot pressing process parameters in step 4) are as follows: the pressing temperature of the hot pressing roller is set to 150-200℃, the pressing pressure is 0.2-1.0MPa, and the roller speed is 0.5-2m / min.

9. A flexible silica-oxygenated nanofiber fireproof insulating winding tape prepared by the preparation method according to any one of claims 1-8.

10. The application of the flexible silica-oxygen nanofiber fireproof insulating winding tape according to claim 9 in the fields of fireproofing, heat insulation, and insulation.

Images