Ceramic rubber heat insulation pad core material as well as preparation method and application thereof

Abstract

The invention relates to the field of heat insulation pads, and provides a ceramic rubber heat insulation pad core material and a preparation method and application thereof. The preparation method of the ceramic rubber heat insulation pad core material comprises the following steps: uniformly dispersing fumed silica, silicon carbide and sepiolite fibers, adding polytetrafluoroethylene, and carrying out ball milling to obtain a mixture; putting the mixture on glass fiber mesh cloth, and performing dry pressing to obtain a pre-pressed gasket; the two pre-pressing gaskets are stacked, the glass fiber mesh cloth is located on the outer side, after primary rolling, the glass fiber mesh cloth is rotated by 60-90 degrees for secondary rolling, and a rough blank of the heat insulation pad is obtained after circulation is conducted for multiple times; and putting the mixture into a vacuum container, and introducing hexamethyldisilazane for fumigation to obtain a product. The polytetrafluoroethylene is added into the raw materials, and the PTFE is in a net shape after being fiberized in a system by adjusting the rolling direction and pressure, so that the mechanical property and the flexibility of the ceramic rubber gasket are greatly improved, and meanwhile, the phenomenon of powder falling of a core material of the ceramic rubber gasket is thoroughly eliminated. The invention further provides the ceramic rubber heat insulation pad core material and application of the ceramic rubber heat insulation pad core material in a ceramic rubber heat insulation pad.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation pads, and in particular to a ceramic rubber thermal insulation pad core material, its manufacturing method, and its application. Background Technology

[0002] The mainstream thermal runaway protection pads for lithium-ion battery cells are SiO2 aerogel pads. Typical aerogel pad models include those manufactured by Aspen Aerogel. Audemars Piguet and its company produce Aerogel thermal insulation pads. However, the production process of aerogel pads involves steps such as hydrolysate preparation, catalyst solution preparation, gel coating, aging, solvent replacement, supercritical drying, gas / liquid phase hydrophobicity, core material cutting, and core material vacuum thermopressing encapsulation. The production process is complex, requires large investment in production line equipment, and results in high product production costs.

[0003] Johns Manville invented it. Nano-insulation panels (US Patent No. 2811457) are made primarily from fumed SiO2 powder or SiO2 aerogel powder, with added functional additives such as oxide short fiber reinforcement and infrared radiation resistant micronized powder. The mixture is then mixed and pressed to obtain a nano-insulation panel blank, which is then lightly sintered or directly encapsulated with an encapsulation film without sintering to obtain the nano-insulation panel. During dry mixing, the nanoparticles disperse in the air, posing a significant health risk to frontline production workers. Lithium-ion battery cell thermal runaway protection pads prepared using fumed SiO2 powder molding processes suffer from drawbacks such as poor mechanical strength, easy dispersion of nanoparticle dust into the battery packaging after the outer encapsulation film ruptures, and reduced reliability of electronic components in the Battery Thermal Management System (BTMS). Therefore, an ideal solution is needed. Summary of the Invention

[0004] This invention provides a ceramic rubber heat insulation pad core material, its manufacturing method, and its application. Polytetrafluoroethylene (PTFE) is added to the raw materials, and by adjusting the direction and pressure of the roller pressing, the PTFE is made into a network after being fibrous in the system, which greatly improves the mechanical properties and flexibility of the ceramic rubber pad, while completely eliminating the phenomenon of powder shedding from the ceramic rubber pad core material.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for manufacturing a ceramic rubber thermal insulation pad core material includes the following steps: A. Disperse fumed silica, silicon carbide and sepiolite fibers evenly, add polytetrafluoroethylene, and ball mill to obtain a mixture; place the mixture on a glass fiber mesh and dry press to obtain a pre-compression gasket; B. Stack two pre-compression pads with the fiberglass mesh on the outside. After one roll pressing, rotate 60-90° for a second roll pressing. Repeat this process several times to obtain the thermal insulation pad blank. C. Place the thermal insulation pad blank in a vacuum container and fumigate it with hexamethyldisilazane to obtain a hydrophobic thermal insulation pad core material.

[0006] As a preferred embodiment, the mass ratio of fumed silica, silicon carbide, sepiolite fiber and polytetrafluoroethylene is 90-95:2-4:5-10:4-6.

[0007] Preferably, fumed silica is hydrophilic with a surface area of ​​170-230 m². 2 / g; silicon carbide particle size is 2.5-5μm.

[0008] Preferably, step A is carried out in a high-speed shear mill, and mixed at 700-900 rpm for 8-12 minutes.

[0009] Preferably, ball milling is carried out in a ball mill with a ball-to-material volume ratio of 1:2-4, a ball mill speed of 500-800 rpm, and a milling time of 10-15 min.

[0010] Preferably, the areal density of the glass fiber mesh is 30-50 g / m². 2 .

[0011] Preferably, dry pressing is performed in a dry pressing mold, and pressure is maintained at 15-25MPa for 3-8 minutes.

[0012] Preferably, the apparent density of the pre-compression gasket is 0.1-0.5 g / cm³. 3 The thickness is 1-2mm; the apparent density of the thermal insulation pad blank is 0.3-0.35g / cm³. 3 The thickness is 2-2.2mm.

[0013] Preferably, the pressure of the primary roller pressing is 0.6 to 0.8 MPa, and the pressure of the secondary roller pressing is 0.3 to 0.5 MPa.

[0014] Preferably, the fumigation conditions are 100-120℃ for 30-60 minutes; the dosage of hexamethyldisilazane is 10-30 g / m³. 3 .

[0015] The present invention also provides a ceramic rubber heat insulation pad core material, which is prepared by the above method.

[0016] The vibration mass loss rate of the ceramic rubber thermal insulation pad core material is less than 0.2%, the tensile elongation at break is ≥10%, and it is Class A flame retardant (classified as Class A according to GB 8624-2018 Classification of Burning Performance of Building Materials and Products).

[0017] As an application of the above-mentioned ceramic rubber heat insulation pad core material, the present invention also provides a ceramic rubber heat insulation pad, which is made by encapsulating the ceramic rubber heat insulation pad core material with a PET encapsulation film.

[0018] Preferably, the heat insulation pad core material is encapsulated at 100–110°C, and the air pressure inside the encapsulation bag is ≤5 kPa.

[0019] As a preferred option, ceramic rubber thermal insulation pads are used as protective pads for thermal runaway of battery cells.

[0020] Therefore, the beneficial effects of the present invention are: (1) By adding polytetrafluoroethylene to the raw materials and adjusting the direction and pressure of the roller, PTFE is made into a network after being fibrous in the system, which greatly improves the mechanical properties and flexibility of the ceramic rubber gasket, and at the same time completely eliminates the phenomenon of powder shedding from the ceramic rubber gasket core material; (2) The ceramic rubber gasket core material is subjected to intrinsic hydrophobic treatment to prevent the ceramic rubber gasket from absorbing moisture in rainy weather and high humidity areas in the south, which would lead to a decrease in thermal insulation performance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the ceramic rubber thermal insulation pad core material.

[0022] Figure 2 This is an SEM image of the ceramic rubber thermal insulation pad core material. Detailed Implementation

[0023] The technical solution of the present invention will be further described below through specific embodiments.

[0024] In this invention, unless otherwise specified, the raw materials and equipment used are commercially available or commonly used in the art. The methods in the embodiments, unless otherwise specified, are conventional methods in the art. Unless otherwise specified, all parts are parts by weight, temperatures are expressed in °C or at ambient temperature, and pressures are at or near atmospheric pressure. Various variations and combinations of reaction conditions (e.g., component concentrations, required solvents, solvent mixtures, temperature, pressure, and other reaction ranges) and conditions that can be used to optimize the purity and yield of the product obtained by the method exist, and only reasonable routine experiments are needed to optimize such method conditions.

[0025] Example I. A method for preparing a ceramic rubber thermal insulation pad core material Includes the following steps: S1. Weigh the raw materials according to the following formula: Hydrophilic fumed silica (surface area 170-230m²) 2 / g) 90-95 parts Silicon carbide powder (particle size 2.5-5μm) 2-4 parts 5-10 parts sepiolite fiber Add the above three materials to a high shear mixer according to the above ratio, mix at 700-900 rpm for 8-12 minutes to obtain a uniformly dispersed composition A.

[0026] S2. Place composition A and 4-6 parts of polytetrafluoroethylene into a horizontal ball mill and ball mill, filling the volume to 50-60%, wherein the ball-to-material volume ratio is 1:2-4. The ball mill speed is 500-800 rpm, and the ball milling time is 10-15 minutes to obtain composition B.

[0027] By introducing a fiber-forming PTFE component into the thermal insulation material formulation and employing a multi-stage rolling process, the PTFE component is fully fiberized, effectively binding the micro- and nano-powders within the system. Furthermore, due to the fiberization of PTFE, the ceramic rubber thermal insulation pad exhibits a tensile elongation at break of ≥10%, demonstrating plastic deformation characteristics similar to those of plastics.

[0028] S3. Place a piece of material with a surface density of 30-50 g / m² at the bottom of the dry pressing mold. 2 The glass mesh is then added to composition B and placed into a dry-pressing mold. The mold is pressed to 15-25 MPa and held for 3-8 minutes. After demolding, an apparent density of 0.1-0.5 g / cm³ is obtained. 3 Pre-compression gaskets with a thickness of 2-2.2mm.

[0029] S4. Stack two pre-compression pads so that the glass mesh is located on the upper and lower surfaces of the stack. Feed the stacked pre-compression pads into a roller press. After one roller pass, rotate the sample stage 60-90° for a second roller press. The pressure of the first roller press is 0.6-0.8 MPa, and the pressure of the second roller press is 0.3-0.5 MPa. After 3-6 roller press cycles, an apparent density of 0.30-0.35 g / cm³ is obtained. 3 C, a ceramic rubber heat insulation pad blank with a thickness of 2-2.2mm.

[0030] Multi-stage rolling systems only roll in one direction, causing PTFE to primarily fiberize along that direction, with low fiberization perpendicular to the rolling direction. This results in poor tear resistance for ceramic rubber gasket rolls. This invention, through bidirectional or multidirectional rolling, allows PTFE to fiberize into a network within the system, significantly improving the mechanical properties and flexibility of the ceramic rubber gasket while completely eliminating powder shedding from the core material.

[0031] The purpose of roller pressing is to make the bond between composition B and the glass mesh fabric denser and more uniform in thickness, while simultaneously allowing PTFE to form a mesh structure after fiberization within the system. There are gaps between the particles of composition B; therefore, during roller pressing, the particles can undergo small displacement movements to fill these gaps, allowing them to position themselves under compaction. The particles undergo displacement and deformation under pressure. During the first roller pressing, as the contact pressure increases, the particles of composition B begin to exhibit small-scale displacement, which gradually increases. At this point, the gaps between the particles are gradually filled, and the apparent density of the gasket increases slowly with increasing contact pressure, as PTFE fiberizes within the system. During the second roller pressing, most of the gaps between the particles are compressed and compacted. PTFE, after fiberization within the system, forms a mesh-like coating, and the apparent density of the gasket increases rapidly under contact pressure; some composition B particles may even deform. Therefore, properly controlling the pressure of the two roller pressing cycles can control the microstructure of the components and the coating of PTFE, resulting in better overall performance of the gasket.

[0032] S5. Vapor-phase hydrophobicity: A batch of ceramic rubber heat insulation pad blanks C are dispersed and placed in a vacuum hydrophobic tank at intervals. After sealing the tank, a vacuum is drawn, and the tank is heated to 100-120°C. The hexamethyldisilazane storage tank outlet valve on the top of the tank is opened, and hexamethyldisilazane is drawn into the vacuum hydrophobic tank. The dosage of hexamethyldisilazane is 10-30 g / m³. 3 Close the valve and maintain the temperature and negative pressure for fumigation for 30-60 minutes. After fumigation, turn off the heating and cool down to room temperature. Then open the suction valve to draw air into the vacuum condensate tank. Once atmospheric pressure is reached, open the top cover of the vacuum condensate tank and remove the intrinsically hydrophobic ceramic rubber thermal insulation pad core material D.

[0033] Since the target market for ceramic rubber gaskets is fireproof and heat-insulating gaskets between lithium-ion battery cells, the outer encapsulation film of the gasket core material is at risk of damage during long-term use. Therefore, this invention performs intrinsic hydrophobic treatment on the ceramic rubber gasket core material to prevent the ceramic rubber gasket from absorbing moisture and causing a decrease in heat insulation performance during rainy weather and in high-humidity areas in the south. The vapor-phase fumigation hydrophobic process has advantages such as low hydrophobic agent dosage, minimal product weight gain, and low process cost.

[0034] S6. Core material cutting: The ceramic rubber heat insulation pad core material D is cut to the standard pad size using a laser cutting machine.

[0035] II. A ceramic rubber heat insulation pad core material is obtained by the above preparation method.

[0036] The vibration mass loss rate of the ceramic rubber thermal insulation pad core material is less than 0.2%, and the tensile elongation at break is ≥10%. Since 95% of the raw material formula of the ceramic rubber thermal insulation pad is inorganic, the pad is Class A flame retardant.

[0037] III. Application of Ceramic Rubber Thermal Insulation Pad Core Material The core material obtained in S6 is used in a ceramic rubber heat insulation pad. The specific steps are as follows: the core material is vacuum heat-sealed at 100-110°C using a PET encapsulation film, with the air pressure inside the encapsulation bag ≤5kPa, to obtain the ceramic rubber heat insulation pad.

[0038] Ceramic rubber thermal insulation pads can be used as protective pads for thermal runaway of battery cells.

[0039] Example 1 A method for preparing a ceramic rubber thermal insulation pad core material, comprising the following steps: S1. Weigh the raw materials according to the following formula: Wacker Silicon N-20 Hydrophilic Fumed Silica (Surface Area 170-230 m²) 2 / g) 92 portions 3 parts of W3.5 silicon carbide powder from Beijing Micro-Nano Ultrafine Materials Co., Ltd. Hebei Hongli 5-50 type sepiolite fiber 5 parts Add the above three materials to the product manufactured by Hosokawa Micron Co., Ltd. of Japan according to the above ratio. The mixture was mixed at 800 rpm for 10 minutes using a high shear mixer to obtain a uniformly dispersed composition A.

[0040] S2. 95 parts of composition A and 5 parts of Chemours 601X polytetrafluoroethylene (PTFE) manufactured by DuPont were placed in a horizontal ball mill and ball-milled to a filling volume of 60%, with a ball-to-material volume ratio of 1:3. The ball mill was rotated at 600 rpm for 10 minutes to obtain composition B.

[0041] S3. Place a piece with a surface density of 40 g / m² at the bottom of the dry pressing mold. 2 The glass mesh was then used, and composition B was added to a dry-pressing mold. The mold was pressed to 20 MPa and held for 5 minutes. After demolding, an apparent density of 0.2 g / cm³ was obtained. 3 A pre-compression gasket with a thickness of 2mm.

[0042] S4. Stack two pre-compression pads so that the glass mesh is located on the upper and lower surfaces of the stack. Feed the stacked pre-compression pads into the roller press. After one roller press, rotate the sample stage 90° and perform a second roller press orthogonally. The pressure of the first roller press is 0.6 MPa, and the pressure of the second roller press is 0.6 MPa. After 4 roller press cycles, a total of 8 roller presses, an apparent density of 0.33 g / cm³ is obtained. 3 C, a ceramic rubber heat insulation pad blank with a thickness of 2.1±0.1mm.

[0043] S5. Vapor Phase Hydrophobicity: A batch of ceramic rubber heat insulation pad blanks C are dispersed and placed in a vacuum hydrophobic tank at intervals. After sealing the tank, a vacuum is drawn, and the tank is heated to 110°C. The hexamethyldisilazane storage tank outlet valve on the top of the tank is opened to draw the hexamethyldisilazane hydrophobic agent into the vacuum hydrophobic tank. The hydrophobic agent dosage is 20g / m³. 3 Close the valve and maintain the temperature and negative pressure for 40 minutes. After fumigation, turn off the heating and cool down to room temperature. Then open the suction valve to draw air into the vacuum condensate tank. Once atmospheric pressure is reached, open the top cover of the vacuum condensate tank and remove the intrinsically hydrophobic ceramic rubber thermal insulation pad core material D.

[0044] S6. Core Material Cutting: The ceramic rubber heat insulation pad core material D is cut to the standard gasket size using a laser cutting machine, such as... Figure 1 As shown.

[0045] SEM image of ceramic rubber thermal insulation pad core material as shown below Figure 2 As shown, the vibration mass loss rate of the ceramic rubber thermal insulation pad core material is less than 0.2%, and the tensile elongation at break is 12%. According to GB 8624-2018, the fire performance classification of building materials and products is Class A.

[0046] Example 2 A method for preparing a ceramic rubber thermal insulation pad core material, comprising the following steps: S1. Weigh the raw materials according to the following formula: Wacker Silicon N-20 Hydrophilic Fumed Silica (Surface Area 170-230 m²) 2 90 servings (g) Two parts of W3.5 silicon carbide powder from Beijing Micro-Nano Ultrafine Materials Co., Ltd. Hebei Hongli 5-50 type sepiolite fiber 8 parts Add the above three materials to the product manufactured by Hosokawa Micron Co., Ltd. of Japan according to the above ratio. The mixture was mixed at 700 rpm for 12 minutes using a high shear mixer to obtain a uniformly dispersed composition A.

[0047] S2. 96 parts of composition A and 4 parts of Chemours 601X polytetrafluoroethylene (PTFE) manufactured by DuPont were placed in a horizontal ball mill and ball-milled to a filling volume of 50%, with a ball-to-material volume ratio of 1:2. The ball mill was rotated at 500 rpm for 15 minutes to obtain composition B.

[0048] S3. Place a piece with a surface density of 30g / m² at the bottom of the dry pressing mold. 2 The glass mesh was then used, and composition B was added to a dry-pressing mold. The mold was pressed to 15 MPa and held for 8 minutes. After demolding, an apparent density of 0.1 g / cm³ was obtained. 3 A pre-compression gasket with a thickness of 2mm.

[0049] S4. Stack two pre-compression pads so that the glass mesh is located on the upper and lower surfaces of the stack. Feed the stacked pre-compression pads into the roller press. After one roller press, rotate the sample stage 90° and perform a second roller press orthogonally. The pressure of the first roller press is 0.6 MPa, and the pressure of the second roller press is 0.6 MPa. After 4 roller press cycles, a total of 8 roller presses, an apparent density of 0.35 g / cm³ is obtained. 3 C, a ceramic rubber heat insulation pad blank with a thickness of 2.1±0.1mm.

[0050] S5. Vapor Phase Hydrophobicity: A batch of ceramic rubber heat insulation pad blanks C are dispersed and placed in a vacuum hydrophobic tank at intervals. After sealing the tank, a vacuum is drawn, and the tank is heated to 120°C. The hexamethyldisilazane storage tank outlet valve on the top of the tank is opened to draw the hexamethyldisilazane hydrophobic agent into the vacuum hydrophobic tank. The hydrophobic agent dosage is 30g / m³. 3 Close the valve and maintain the temperature and negative pressure for 30 minutes of fumigation. After fumigation, turn off the heating and cool down to room temperature. Then open the suction valve to draw air into the vacuum condensate tank. Once atmospheric pressure is reached, open the top cover of the vacuum condensate tank and remove the intrinsically hydrophobic ceramic rubber heat insulation pad core material D.

[0051] S6. Core material cutting: The ceramic rubber heat insulation pad core material D is cut to the standard pad size using a laser cutting machine.

[0052] Example 3 A method for preparing a ceramic rubber thermal insulation pad core material, comprising the following steps: S1. Weigh the raw materials according to the following formula: Wacker Silicon N-20 Hydrophilic Fumed Silica (Surface Area 170-230 m²) 2 91 servings (g) 4 parts of W3.5 silicon carbide powder from Beijing Micro-Nano Ultrafine Materials Co., Ltd. Hebei Hongli 5-50 type sepiolite fiber 5 parts Add the above three materials to the product manufactured by Hosokawa Micron Co., Ltd. of Japan according to the above ratio. The mixture was mixed at 900 rpm for 8 minutes using a high shear force mixer to obtain a uniformly dispersed composition A.

[0053] S2. 94 parts of composition A and 6 parts of Chemours 601X polytetrafluoroethylene (PTFE) manufactured by DuPont were placed in a horizontal ball mill and ball-milled to a filling volume of 60%, with a ball-to-material volume ratio of 1:4. The ball mill was rotated at 800 rpm for 12 minutes to obtain composition B.

[0054] S3. Place a piece with a surface density of 50 g / m² at the bottom of the dry pressing mold. 2The glass mesh was then used, and composition B was added to a dry-pressing mold. The mold was pressed to 25 MPa and held for 3 minutes. After demolding, an apparent density of 0.5 g / cm³ was obtained. 3 A pre-compression pad with a thickness of 1mm.

[0055] S4. Stack two pre-compression pads so that the glass mesh is located on the upper and lower surfaces of the stack. Feed the stacked pre-compression pads into the roller press. After one roller press, rotate the sample stage 90° and perform a second roller press orthogonally. The pressure of the first roller press is 0.6 MPa, and the pressure of the second roller press is 0.6 MPa. After 4 roller press cycles, a total of 8 roller presses, an apparent density of 0.30 g / cm³ is obtained. 3 C, a ceramic rubber heat insulation pad blank with a thickness of 2.1±0.1mm.

[0056] S5. Vapor Phase Hydrophobicity: A batch of ceramic rubber heat insulation pad blanks C are dispersed and placed in a vacuum hydrophobic tank at intervals. After sealing the tank, a vacuum is drawn, and the tank is heated to 100°C. The hexamethyldisilazane storage tank outlet valve on the top of the tank is opened to draw the hexamethyldisilazane hydrophobic agent into the vacuum hydrophobic tank. The hydrophobic agent dosage is 10g / m³. 3 Close the valve and maintain the temperature and negative pressure for 60 minutes. After fumigation, turn off the heating and cool down to room temperature. Then open the suction valve to draw air into the vacuum condensate tank. Once atmospheric pressure is reached, open the top cover of the vacuum condensate tank and remove the intrinsically hydrophobic ceramic rubber thermal insulation pad core material D.

[0057] S6. Core material cutting: The ceramic rubber heat insulation pad core material D is cut to the standard pad size using a laser cutting machine.

[0058] Example 4 The difference from Example 1 is that in step S4, the pressure of the secondary rolling is 0.4 MPa.

[0059] Example 5 The difference from Example 1 is that in step S4, the pressure of each roll pressing is 0.4 MPa.

[0060] Example 6 The difference from Example 1 is that in step S4, after the first rolling, the sample stage is rotated 60° to perform a second rolling.

[0061] Application examples The ceramic rubber heat insulation pad core material D prepared in the above embodiments is vacuum heat-pressed to obtain a ceramic rubber heat insulation pad. Specifically, a PET encapsulation film is used, and the encapsulation is carried out at 100-110°C, with the air pressure inside the encapsulation bag ≤5kPa.

[0062] Comparative Example Comparative Example 1 The difference from Example 1 is that PTFE was not added.

[0063] The tensile elongation at break of the prepared ceramic rubber heat insulation pad core material was 0.2%, which was much lower than that of Example 1.

[0064] Comparative Example 2 The difference from Example 1 is that in step S4, the sample stage does not rotate after one rolling, that is, it is always rolled in one direction.

[0065] Comparative Example 3 The difference from Example 1 is that in step S4, after the first rolling, the sample stage is rotated 60° to perform a second rolling.

[0066] Performance testing The performance of the ceramic rubber thermal insulation pad core materials obtained in each embodiment and comparative example was tested. The test method was as follows: (1) Combustion performance. According to GB 8624—2018 "Classification of Combustion Performance of Building Materials and Products", the ceramic rubber heat insulation pad core material of each embodiment is identified as Class A.

[0067] (2) Vibration mass loss rate. The vibration mass loss rate was measured according to Appendix B of GB / T 34336-2017 "Nanoporous Aerogel Composite Thermal Insulation Products". The results are shown in the table below.

[0068] (3) Room temperature thermal conductivity of the gasket. Tested according to GB / T 10295-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials - heat flow meter method". The results are shown in the table below. Tensile strength in the planar direction (kPa) Vibrational mass loss rate of core material (%) Thermal conductivity at 20℃ (W / (m·K)) Example 1 110 0.171 0.020 Example 2 107 0.178 0.021 Example 3 112 0.172 0.020 Example 4 120 0.150 0.018 Example 5 103 0.192 0.021 Example 6 100 0.196 0.023 Comparative Example 1 60 82.45 0.021 Comparative Example 2 85 0.346 0.029 Comparative Example 3 91 0.253 0.024

[0069] As can be seen from the table above, the ceramic rubber heat insulation pad core materials prepared in each embodiment have high tensile strength, low vibration mass loss rate and low thermal conductivity. When used as ceramic rubber heat insulation pads, they have excellent mechanical properties and heat insulation properties and are not prone to powder shedding.

[0070] Compared with Example 1: (1) The pressure of the two rolling processes was adjusted in Examples 4 and 5. In Example 1, the pressure of the two rolling processes was 0.6 MPa; in Example 4, the first rolling process was 0.6 MPa and the second rolling process was 0.4 MPa; in Example 5, the first rolling process was 0.4 MPa and the second rolling process was 0.6 MPa. During the first rolling process, the gaps between particles are large and the displacement is large, so the pressure can be higher to promote compaction and PTFE fiberization. During the second rolling process, most of the gaps are filled, and the density can be greatly improved with a lower pressure. Therefore, the pressure of the second rolling process in Example 4 is lower than that of the first rolling process, and the effect is better. In Example 5, the pressure of the second rolling process is higher than that of the first rolling process, which will cause B particles to deform, affect the microstructure of the core material, and is not conducive to the fiber networking of PTFE, thereby reducing the overall performance of the core material.

[0071] (2) In Example 6 and Comparative Examples 2 and 3, the angles of the two rolling processes were adjusted. In Example 1, the two rolling processes differed by 90°, which was exactly orthogonal, resulting in the best rolling effect. In Comparative Example 2, the two rolling processes differed by 0°, meaning that the rolling was done only in one direction. During the rolling process, PTFE mainly fibrousized along the rolling direction, with a low degree of fibrosis perpendicular to the rolling direction. Therefore, the ceramic rubber gasket roll had poor tear resistance. In Comparative Example 3, the two rolling processes differed by 40°, which was below the preferred range, resulting in a less effective rolling effect than in Example 1.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for manufacturing a ceramic rubber thermal insulation pad core material, characterized in that, Includes the following steps: A. Disperse fumed silica, silicon carbide and sepiolite fibers evenly, add polytetrafluoroethylene, and ball mill to obtain a mixture; place the mixture on a glass fiber mesh and dry press to obtain a pre-compression gasket; B. Stack two pre-compression pads with the fiberglass mesh on the outside. After one roll pressing, rotate 60-90° for a second roll pressing. Repeat this process several times to obtain the thermal insulation pad blank. C. Place the thermal insulation pad blank in a vacuum container and fumigate it with hexamethyldisilazane to obtain a hydrophobic thermal insulation pad core material.

2. The method for manufacturing a ceramic rubber thermal insulation pad core material according to claim 1, characterized in that, The mass ratio of fumed silica, silicon carbide, sepiolite fiber and polytetrafluoroethylene is 90-95:2-4:5-10:4-6.

3. A method for manufacturing a ceramic rubber thermal insulation pad core material according to claim 1 or 2, characterized in that, Ball milling is carried out in a ball mill with a ball-to-material volume ratio of 1:2-4, a ball mill speed of 500-800 rpm, and a milling time of 10-15 min.

4. The method for manufacturing a ceramic rubber thermal insulation pad core material according to claim 1, characterized in that, The areal density of fiberglass mesh is 30-50 g / m². 2 .

5. A method for manufacturing a ceramic rubber thermal insulation pad core material according to claim 1 or 4, characterized in that, Dry pressing is carried out in a dry pressing mold, and the pressure is maintained at 15-25 MPa for 3-8 minutes.

6. The method for manufacturing a ceramic rubber thermal insulation pad core material according to claim 1, characterized in that, The apparent density of the pre-compression gasket is 0.1-0.5 g / cm³. 3 The thickness is 1-2 mm; the apparent density of the thermal insulation pad blank is 0.3-0.35 g / cm³. 3 The thickness is 2-2.2 mm.

7. The method for manufacturing a ceramic rubber thermal insulation pad core material according to claim 1, characterized in that, The pressure of the first rolling is 0.6~0.8 MPa, and the pressure of the second rolling is 0.3~0.5 MPa.

8. A method for manufacturing a ceramic rubber thermal insulation pad core material according to claim 1 or 7, characterized in that, The fumigation conditions are 100-120 ℃ for 30-60 min; the dosage of hexamethyldisilazane is 10-30 g / m³. 3 .

9. A ceramic rubber thermal insulation pad core material, prepared by any one of claims 1-8, characterized in that, Elongation at break ≥10%.

10. A ceramic rubber heat insulation pad, characterized in that, It is prepared by encapsulating the ceramic rubber heat insulation pad core material as described in claim 9.

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