A dry-molded thermal insulation material and its preparation method and application

Abstract

The present invention relates to the field of thermal insulation materials, and discloses a dry-molded thermal insulation material and a preparation method and application thereof, which is made by rolling mixed raw materials; in parts by weight, the mixed raw materials include: 60 to 100 parts of powder material, 0.1 to 30 parts of polymer binder, 0 to 20 parts of high-temperature bonding aid, and 0 to 10 parts of sunscreen. The present invention mixes the powder material with the polymer binder, sunscreen, and high-temperature bonding aid, and the heat insulation material obtained by roll-molding has the same heat insulation performance as aerogel material, and has excellent mechanical properties, good toughness, stretchability, and ductility; at the same time, the preparation process is simple, the manufacturing cost is low, and the application field is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of heat-insulating materials, and in particular to a dry-molded heat-insulating material and a preparation method and application thereof. Background Art

[0002] Thermal insulation materials have many applications in aerospace, chemical industry, new energy, consumer electronics, construction and other fields, especially as thermal protection materials for isolating high temperatures on the outer surface of aircraft; as thermal insulation materials in oil, gas and chemical pipelines and building exterior walls; as thermal safety materials in secondary battery modules such as lithium batteries and sodium-ion batteries, electric vehicles, and energy storage equipment; and as thermal insulation materials in electronic products such as mobile phones and e-cigarettes.

[0003] Among the existing thermal insulation materials, aerogel materials have excellent thermal insulation properties, and their room temperature and high temperature thermal conductivity coefficients are generally lower than other thermal insulation materials. However, the aerogel preparation process is complicated, the preparation equipment is expensive, and the production cost is high. In addition, the mechanical properties of aerogel materials are poor, showing brittleness. Therefore, when used in many fields, aerogel materials need to be compounded with porous matrix materials (such as ceramic fibers, glass fibers, polymer fibers, etc.) to improve their overall mechanical properties. However, the composite material has the problem of aerogel powder falling off. The falling of powder will reduce the overall thermal insulation of the material, and the powder can be easily inhaled into the human respiratory tract, affecting health.

[0004] The development of dry-molded insulation materials that can replace aerogel materials has become a research hotspot. For example, the patent with publication number CN101671157A discloses a high-efficiency insulation material for high-temperature pipelines and its preparation method, wherein nano-SiO2 powder, infrared sunscreen agent, and reinforcing fiber are mixed to form a fiber-powder mixture, and then dry-pressed by molding. The patent with publication number CN103693936A discloses a preparation method of a nano-powder-based composite insulation material, which uses nano-powder as a matrix material, adds reinforcing fiber, infrared sunscreen agent, high-temperature shrinkage inhibitor, and hydrophobic agent, and is prepared by dispersion, mixing, and compression molding. However, the dry-molded insulation material in the prior art is generally made by molding, and the obtained insulation material has no toughness, tensile strength, and ductility, cannot be bent, is difficult to be further processed, and is easy to crush during use, which limits its application. Summary of the invention

[0005] The present invention aims to overcome the above-mentioned problems existing in the dry-formed thermal insulation materials in the prior art, and provides a dry-formed thermal insulation material and a preparation method and application thereof. The powder material is mixed with a polymer binder, a sunscreen, and a high-temperature bonding aid, and the thermal insulation material obtained by roller forming has the same thermal insulation performance as the aerogel material, and has excellent mechanical properties, good toughness, tensile strength and ductility; at the same time, the preparation process is simple, the manufacturing cost is low, and the application field is wide.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a dry-molded heat-insulating material, which is formed by rolling mixed raw materials; the mixed raw materials include, by weight: 60 to 100 parts of powder material, 0.1 to 30 parts of polymer binder, 0 to 20 parts of high-temperature bonding aid, and 0 to 10 parts of sunscreen;

[0008] The powder material is selected from one or more of fumed silica, white carbon black, vermiculite powder, aerogel powder, mica powder, and porous natural mineral powder;

[0009] The polymer binder is selected from one or more of PTFE, PVDF, PAN and PAA;

[0010] The high temperature bonding aid is selected from one or two of borax and aluminum tripolyphosphate.

[0011] The present invention mixes the powder material with a polymer binder, a high-temperature bonding aid and a sunscreen, and rolls the mixture to form a heat-insulating material. The heat-insulating properties of the obtained heat-insulating material at room temperature and high temperature (below 1000°C) are at the same level as those of aerogel-type heat-insulating materials. The heat-insulating material of the present invention is made by a dry process of rolling, and compared with aerogel-type heat-insulating materials, the preparation process is simple, the preparation cost is low, and it is suitable for large-scale industrial applications. At the same time, the polymer binder added by the present invention can be fiberized during the rolling process, and the powder material, the high-temperature bonding aid and the sunscreen are connected together. While not affecting the heat-insulating properties of the heat-insulating material, the obtained heat-insulating material can have good toughness, tensile strength and ductility, which is convenient for subsequent further processing of the dry heat-insulating material, and makes the dry heat-insulating material not easy to bend and crush during use. Since the polymer binder will liquefy or even decompose when the thermal insulation material is used at high temperature, causing the thermal insulation material to shatter at high temperature, the present invention adds a high-temperature bonding aid to the mixed raw materials. Even if the polymer binder liquefies or decomposes at high temperature, the high-temperature bonding aid can also play a shaping role, thereby ensuring the mechanical stability of the thermal insulation material at high temperature.

[0012] Preferably, the specific surface area of ​​the powder material is ≥200 m 2 / g. The use of powder materials with high specific surface area is beneficial to improving the thermal insulation performance of the materials.

[0013] Preferably, the molecular weight of the polymer binder is ≥ 100,000.

[0014] Preferably, the sunscreen is selected from one or both of silicon carbide and titanium dioxide; the particle size of the sunscreen is 1-5 μm. Adding a sunscreen with infrared reflection function can improve the thermal insulation performance of the material at high temperature.

[0015] Preferably, the thickness of the dry-molded thermal insulation material is 50 μm to 20 cm, and the density is 0.1 to 0.5 g / cm 3 The dry-molded heat-insulating material of the present invention may be a complete continuous body in the form of a film, a sheet or a block.

[0016] In a second aspect, the present invention provides a method for preparing the above-mentioned dry-molded thermal insulation material, comprising the following steps:

[0017] (1) Mixing powder material, polymer binder, high temperature bonding aid and light shielding agent in proportion to obtain a mixed raw material;

[0018] (2) Rolling the mixed raw materials to obtain the dry-formed thermal insulation material.

[0019] Preferably, the mixing process of step (1) and / or the rolling process of step (2) are carried out under heating, and the heating temperature is lower than 350°C. The mixing methods of step (1) include mechanical stirring mixing, internal mixer mixing, ball mill mixing, grinder mixing, air flow mill mixing, vibration mixing, etc. The mixing process can make the polymer binder fiberized; the mixing process is carried out under heating, which is conducive to the uniformity of the mixture and the fiberization of the polymer binder. In step (2), rolling can be carried out by equipment such as an open mill, a roller press, a grinder, and a calender to extend and fiberize the polymer binder and increase the uniformity of the overall material; the rolling process is carried out under heating, which is conducive to the fiberization of the polymer binder and improves the toughness of the thermal insulation material.

[0020] Preferably, in step (2), the mixed raw material is first extruded by an extruder and then roller-pressed; the extrusion process is heated at a temperature lower than 350°C.

[0021] Preferably, in step (2), a hydrophobic layer is coated on the surface of the dry-formed thermal insulation material after rolling; and / or the obtained dry-formed thermal insulation material is encapsulated with one of a polymer film and an aluminum-plastic film; and / or the obtained dry-formed thermal insulation material is compounded with other thermal insulation materials. The thermal insulation material obtained after rolling of the present invention has good toughness and can be further processed. The hydrophobic material can be attached to the surface of the thermal insulation material by dipping, spraying, spin coating, etc. to improve the hydrophobicity of the material; the hydrophobic material is preferably polyurea, silane, fluorocarbon coating, polyester, etc. The obtained thermal insulation material can also be encapsulated by a polymer film, an aluminum-plastic film, etc., and can also be compounded with other thermal insulation materials such as silica gel, foam, rock wool, etc. to further improve its thermal insulation performance.

[0022] In a third aspect, the present invention provides an application of the above-mentioned dry-formed thermal insulation material or the dry-formed thermal insulation material prepared by the above-mentioned preparation method, which is used as a thermal protection or thermal insulation material for batteries, thermal insulation materials for electronic products, thermal insulation materials for buildings or thermal insulation materials for pipelines.

[0023] The dry-molded insulation material in the present invention can be applied to the insulation and thermal safety protection materials of lithium-ion batteries, sodium-ion batteries, lithium metal batteries, solid-state batteries and other batteries. Specifically, it can be placed between battery cells, between battery modules, on the battery cover, on the inner and outer walls of energy storage containers, between battery module layers, around battery modules, etc., to prevent the thermal spread and thermal runaway of the battery module and improve the safety of the battery module. In more detail, it can be applied to electric vehicles and energy storage systems to improve their safety; it can also be used for high-temperature batteries, specifically sodium-nickel chloride batteries, liquid metal batteries, and high-temperature sodium-sulfur batteries. As a thermal insulation material, it plays a role in thermal insulation and energy saving, and improves the energy efficiency of the battery system. The thermal insulation material in the present invention can be applied to thermal insulation materials for electronic products, especially as thermal insulation films for mobile phones, electronic cigarettes and vehicle-mounted electronic devices. The thermal insulation material of the present invention can also be used for building thermal insulation materials or pipeline thermal insulation materials.

[0024] Therefore, the present invention has the following beneficial effects:

[0025] (1) The dry process is used to prepare an insulation material with excellent thermal insulation performance. The thermal insulation performance of the obtained insulation material at room temperature and high temperature (below 1000°C) is at the same level as that of high-end insulation materials such as aerogels. At the same time, the mechanical properties are significantly improved and the manufacturing cost is greatly reduced.

[0026] (2) Adding high-temperature bonding additives to thermal insulation materials improves the mechanical stability of the materials at high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1This is a SEM image of the dry-molded thermal insulation material prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0029] In the present invention, unless otherwise specified, all parts and percentages are weight units, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art. The components or equipment in the following embodiments, unless otherwise specified, are universal standard parts or components known to those skilled in the art, and their structures and principles are known to those skilled in the art through technical manuals or conventional experimental methods.

[0030] Overall embodiment:

[0031] A dry-molded heat-insulating material is made by rolling mixed raw materials; the mixed raw materials include, by weight: 60-100 parts of powder material, 0.1-30 parts of polymer binder, 0-20 parts of high-temperature bonding aid, and 0-10 parts of light-shielding agent;

[0032] The powder material is selected from one or more of fumed silica, white carbon black, vermiculite powder, aerogel powder, mica powder, and porous natural mineral powder;

[0033] The polymer binder is selected from one or more of PTFE, PVDF, PAN and PAA;

[0034] The high temperature bonding aid is selected from one or two of borax and aluminum tripolyphosphate.

[0035] As a specific embodiment, the specific surface area of ​​the powder material is ≥200 m 2 / g. The use of powder materials with high specific surface area is beneficial to improving the thermal insulation performance of the materials.

[0036] As a specific implementation manner, the molecular weight of the polymer binder is ≥ 100,000.

[0037] As a specific implementation, the sunscreen is selected from one or both of silicon carbide and titanium dioxide; the particle size of the sunscreen is 1-5 μm. Adding a sunscreen with infrared reflection function can improve the thermal insulation performance of the material at high temperature.

[0038] As a specific implementation method, the thickness of the dry-molded thermal insulation material is 50 μm to 20 cm, and the density is 0.1 to 0.5 g / cm3 The dry-molded heat-insulating material of the present invention may be a complete continuous body in the form of a film, a sheet or a block.

[0039] The preparation method of the above-mentioned dry-molded thermal insulation material comprises the following steps:

[0040] (1) Mixing powder material, polymer binder, high temperature bonding aid and light shielding agent in proportion to obtain a mixed raw material;

[0041] (2) Rolling the mixed raw materials to obtain the dry-formed thermal insulation material.

[0042] As a specific implementation, the mixing process of step (1) and / or the rolling process of step (2) are carried out under heating, and the heating temperature is lower than 350° C. The mixing method of step (1) includes one of mechanical stirring mixing, internal mixer mixing, ball mill mixing, grinder mixing, air flow mill mixing, and vibration mixing; the rolling in step (2) is carried out by one of an open mill, a roller press, a grinder, and a calender.

[0043] As a specific implementation method, in step (2), the mixed raw materials are first extruded through an extruder, and then roller-pressed after extrusion; the extrusion process is heated, and the heating temperature is lower than 350°C.

[0044] As a specific implementation method, after rolling in step (2), a hydrophobic layer is coated on the surface of the dry-formed thermal insulation material by dipping, spraying or spin coating; the hydrophobic layer material is preferably one of polyurea, silane, fluorocarbon coating and polyester;

[0045] and / or encapsulating the obtained dry-formed thermal insulation material with one of a polymer film and an aluminum-plastic film;

[0046] And / or compound the obtained dry-formed thermal insulation material with other thermal insulation materials such as silica gel, foam, rock wool, etc.

[0047] The dry-molded insulation material in the present invention can be applied to the insulation and thermal safety protection materials of lithium-ion batteries, sodium-ion batteries, lithium metal batteries, solid-state batteries and other batteries. Specifically, it can be placed between battery cells, between battery modules, on the battery cover, on the inner and outer walls of energy storage containers, between battery module layers, around battery modules, etc., to prevent the thermal spread and thermal runaway of the battery module and improve the safety of the battery module. In more detail, it can be applied to electric vehicles and energy storage systems to improve their safety; it can also be used for high-temperature batteries, specifically sodium-nickel chloride batteries, liquid metal batteries, and high-temperature sodium-sulfur batteries. As a thermal insulation material, it plays a role in thermal insulation and energy saving, and improves the energy efficiency of the battery system. The thermal insulation material in the present invention can be applied to thermal insulation materials for electronic products, especially as thermal insulation films for mobile phones, electronic cigarettes and vehicle-mounted electronic devices. The thermal insulation material of the present invention can also be used for building thermal insulation materials or pipeline thermal insulation materials.

[0048] Embodiment 1:

[0049] A dry-molded thermal insulation material, the preparation method of which is:

[0050] (1) 80 g of fumed silica (average particle size 100 nm, specific surface area 250 m 2 / g), 2g PTFE powder (molecular weight 20 million, particle size 500μm), 13g silicon carbide powder (average particle size 3 microns), 5g aluminum tripolyphosphate, put into a ball mill with a volume of 3L, and ball mill for 60 minutes to obtain a mixed raw material;

[0051] (2) The ball-milled mixed raw material is extruded through an extruder at 250°C and an extrusion pressure of 30 MPa;

[0052] (3) The extruded material was rolled through a three-roll mill to obtain a dry-molded thermal insulation material with a thickness of 3 mm. The SEM image is shown in Figure 1 shown; from Figure 1 It can be seen that in the dry-molded thermal insulation material prepared by the present invention, the powder material can be connected to form a film through a polymer binder;

[0053] (4) The obtained dry-formed thermal insulation material was cut into square films with a side length of 200 mm and placed on a hot table. The temperature of the hot table was raised to 400°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple and the obtained temperature was 300°C.

[0054] Embodiment 2:

[0055] A dry-molded thermal insulation material, the preparation method of which is:

[0056] (1) 90 g of white carbon black (average particle size 300 nm, specific surface area 350 m2 / g), 5g vermiculite (average particle size 3 μm, specific surface area 50 m 2 / g) and 5g PTFE powder (molecular weight 20 million, particle size 500μm) were placed in an ultrasonic vibration disperser with a volume of 3L, and ultrasonically dispersed for 5 minutes to obtain a mixed raw material;

[0057] (2) repeatedly rolling the dispersed mixed raw materials through a rolling mill at 150° C. to a thickness of 2 mm to obtain a dry-molded thermal insulation material;

[0058] (3) The obtained dry-molded thermal insulation material was cut into a 250 mm × 190 mm film, which was placed between two 50 Ah lithium iron phosphate battery cells and heated on a hot plate, causing thermal runaway in one of the batteries. Within 30 minutes, the other battery did not experience thermal runaway, indicating that the material effectively suppressed the heat propagation process.

[0059] Embodiment 3:

[0060] A dry-molded thermal insulation material, the preparation method of which is:

[0061] (1) 80 g of silica aerogel powder (average particle size 100 nm, specific surface area 300 m 2 / g), 5g of mica powder (average particle size 3 microns), 5g of PVDF powder (molecular weight 20 million, particle size 500μm), and 10g of borax are put into a planetary mixer with a volume of 4L, and stirred and dispersed for 30 minutes to obtain a mixed raw material;

[0062] (2) repeatedly rolling the dispersed mixed raw materials through a roller press at 120° C. to a thickness of 1 mm to obtain a dry-molded thermal insulation material;

[0063] (3) The obtained dry-formed thermal insulation material was cut into square films with a side length of 200 mm, and placed on a hot table. The temperature of the hot table was raised to 60°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple, and the obtained temperature was 20°C.

[0064] (4) After spraying polyurea dispersion on the surface of the obtained dry-molded thermal insulation material and drying it, it was then packaged with a polyimide film and used to simulate the coating of a natural gas pipeline. When the external temperature of the pipeline was 50°C, the internal temperature of the pipeline was always maintained at around 20°C, indicating that the material effectively played a role in insulating the pipeline.

[0065] Embodiment 4:

[0066] A dry-molded thermal insulation material, the preparation method of which is:

[0067] (1) 90 g of fumed silica (average particle size 80 nm, specific surface area 320 m2 / g), 10g PTFE powder (molecular weight 20 million, particle size 500μm), put into a ball mill with a volume of 4L, and ball mill for 5 minutes to obtain a mixed raw material;

[0068] (2) The ball-milled mixed raw material is rolled by a calender to obtain a dry-molded thermal insulation material with a thickness of 200 μm;

[0069] (3) The obtained dry-formed thermal insulation material was cut into square films with a side length of 100 mm and placed on a hot table. The temperature of the hot table was raised to 45°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple, and the obtained temperature was 30°C. This indicates that the obtained dry-formed thermal insulation material can be used for the back cover of a mobile phone as a thermal insulation film material.

[0070] Embodiment 5:

[0071] A dry-molded thermal insulation material, the preparation method of which is:

[0072] (1) 80 g of fumed silica (average particle size 100 nm, specific surface area 250 m 2 / g), 15g PTFE powder (molecular weight 20 million, particle size 500μm), 13g silicon carbide powder (average particle size 3 microns), 5g aluminum tripolyphosphate, put into a ball mill with a volume of 3L, and ball mill for 60 minutes to obtain a mixed raw material;

[0073] (2) The ball-milled mixed raw material is extruded through an extruder at 250°C and an extrusion pressure of 30 MPa;

[0074] (3) rolling the extruded material through a three-roll mill to obtain a dry-molded thermal insulation material with a thickness of 3 mm;

[0075] (4) The obtained dry-formed thermal insulation material was cut into square films with a side length of 200 mm and placed on a hot table. The temperature of the hot table was raised to 400°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple and the obtained temperature was 303°C.

[0076] Embodiment 6:

[0077] A dry-molded thermal insulation material, the preparation method of which is:

[0078] (1) 80 g of fumed silica (average particle size 100 nm, specific surface area 250 m 2 / g), 30g PTFE powder (molecular weight 20 million, particle size 500μm), 13g silicon carbide powder (average particle size 3 microns), 5g aluminum tripolyphosphate, put into a ball mill with a volume of 3L, and ball mill for 60 minutes to obtain a mixed raw material;

[0079] (2) The ball-milled mixed raw material is extruded through an extruder at 250°C and an extrusion pressure of 30 MPa;

[0080] (3) rolling the extruded material through a three-roll mill to obtain a dry-molded thermal insulation material with a thickness of 3 mm;

[0081] (4) The obtained dry-formed thermal insulation material was cut into square films with a side length of 200 mm and placed on a hot table. The temperature of the hot table was raised to 400°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple and the obtained temperature was 305°C.

[0082] Example 7 (without adding aluminum tripolyphosphate):

[0083] A dry-molded thermal insulation material, the preparation method of which is:

[0084] (1) 80 g of fumed silica (average particle size 100 nm, specific surface area 250 m 2 / g), 2g PTFE powder (molecular weight 20 million, particle size 500μm), 13g silicon carbide powder (average particle size 3 microns), put into a ball mill with a volume of 3L, and ball mill for 60 minutes to obtain a mixed raw material;

[0085] (2) The ball-milled mixed raw material is extruded through an extruder at 250°C and an extrusion pressure of 30 MPa;

[0086] (3) rolling the extruded material through a three-roll mill to obtain a dry-molded thermal insulation material with a thickness of 3 mm;

[0087] (4) The obtained dry-formed thermal insulation material was cut into square films with a side length of 200 mm and placed on a hot table. The temperature of the hot table was raised to 400°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple and the obtained temperature was 308°C.

[0088] Embodiment 8:

[0089] A dry-molded thermal insulation material, the preparation method of which is:

[0090] (1) 80 g of fumed silica (average particle size 100 nm, specific surface area 250 m 2 / g), 2g PTFE powder (molecular weight 20 million, particle size 500μm), 13g silicon carbide powder (average particle size 3 microns), 20g aluminum tripolyphosphate, put into a ball mill with a volume of 3L, and ball mill for 60 minutes to obtain a mixed raw material;

[0091] (2) The ball-milled mixed raw material is extruded through an extruder at 250°C and an extrusion pressure of 30 MPa;

[0092] (3) rolling the extruded material through a three-roll mill to obtain a dry-molded thermal insulation material with a thickness of 3 mm;

[0093] (4) The obtained dry-formed thermal insulation material was cut into square films with a side length of 200 mm and placed on a hot table. The temperature of the hot table was raised to 400°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple and the obtained temperature was 307°C.

[0094] Comparative Example 1 (without adding polymer binder):

[0095] A dry-molded thermal insulation material, the preparation method of which is:

[0096] (1) 80 g of fumed silica (average particle size 100 nm, specific surface area 250 m 2 / g), 13g of silicon carbide powder (average particle size 3 μm), and 5g of aluminum tripolyphosphate were put into a ball mill with a volume of 3L and ball-milled for 60 minutes to obtain a mixed raw material;

[0097] (2) The ball-milled mixed raw material is extruded through an extruder at 250°C and an extrusion pressure of 30 MPa;

[0098] (3) The extruded material is rolled through a three-roll mill, but a shaped thermal insulation material cannot be obtained.

[0099] Comparative Example 2 (too much polymer binder added):

[0100] A dry-molded thermal insulation material, the preparation method of which is:

[0101] (1) 80 g of fumed silica (average particle size 100 nm, specific surface area 250 m 2 / g), 40g PTFE powder (molecular weight 20 million, particle size 500μm), 13g silicon carbide powder (average particle size 3 microns), 5g aluminum tripolyphosphate, put into a ball mill with a volume of 3L, and ball mill for 60 minutes to obtain a mixed raw material;

[0102] (2) The ball-milled mixed raw material is extruded through an extruder at 250°C and an extrusion pressure of 30 MPa;

[0103] (3) rolling the extruded material through a three-roll mill to obtain a dry-molded thermal insulation material with a thickness of 3 mm;

[0104] (4) The obtained dry-formed thermal insulation material was cut into square films with a side length of 200 mm and placed on a hot table. The temperature of the hot table was raised to 400°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple and the obtained temperature was 380°C.

[0105] Comparative Example 3 (too much high temperature bonding agent added):

[0106] A dry-molded thermal insulation material, the preparation method of which is:

[0107] (1) 80 g of fumed silica (average particle size 100 nm, specific surface area 250 m 2 / g), 2g PTFE powder (molecular weight 20 million, particle size 500μm), 13g silicon carbide powder (average particle size 3 microns), 30g aluminum tripolyphosphate, put into a ball mill with a volume of 3L, and ball mill for 60 minutes to obtain a mixed raw material;

[0108] (2) The ball-milled mixed raw material is extruded through an extruder at 250°C and an extrusion pressure of 30 MPa;

[0109] (3) rolling the extruded material through a three-roll mill to obtain a dry-molded thermal insulation material with a thickness of 3 mm;

[0110] (4) The obtained dry-formed thermal insulation material was cut into square films with a side length of 200 mm and placed on a hot table. The temperature of the hot table was raised to 400°C. After 60 minutes, the temperature of the front side of the thermal insulation material (the side not in contact with the hot table) was tested by a thermocouple and the obtained temperature was 360°C.

[0111] The mechanical properties, thermal insulation properties and heat resistance of the dry-molded thermal insulation materials obtained in the above embodiments and comparative examples were tested, and the results are shown in Table 1.

[0112] Table 1: Thermal insulation material performance test results

[0113]

[0114] It can be seen from the above test results that the dry-formed thermal insulation materials prepared by the formula and method of the present invention in Examples 1 to 8 have excellent thermal insulation performance at both room temperature and high temperature, and the thermal insulation performance is at the same level as that of high-end aerogel thermal insulation materials. The thermal insulation material of the present invention is made by a dry process of roller pressing, and the preparation process is simpler than that of aerogel thermal insulation materials, and the preparation cost is low, which is suitable for large-scale industrial application; at the same time, the dry thermal insulation material of the present invention has a high tensile strength and can be used for battery module thermal protection materials, mobile phone back cover thermal insulation films, pipeline insulation materials, etc. In addition, when high-temperature auxiliary binders are not added in Examples 2, 4, and 7, the bonding force of the material in a high-temperature environment will be reduced, which will lead to the deterioration of the heat resistance of the material itself. Although the thermal insulation performance can be maintained for a short time at high temperature, it will be pulverized after heating at 700°C for 1h, and the thermal insulation performance will be lost. Compared with other embodiments in which high-temperature auxiliary binders are added, the thermal insulation material can only be used at a lower temperature and cannot be used in high-temperature application scenarios.

[0115] In Comparative Example 1, no polymer binder was added, and the thermal insulation material could not be dry-formed. In Comparative Example 2, too much polymer binder was added, resulting in a decrease in thermal insulation performance compared with the example. In Comparative Example 3, too much high-temperature bonding agent was added, resulting in a decrease in tensile performance compared with the example.

[0116] Although specific embodiments have been used to illustrate the invention, it is understood that the above embodiments are used to understand the methods and core matters of the present invention and cannot be understood as limitations on the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention shall be deemed to be within the protection scope of the present invention.

Claims

1. A method for preparing a dry-molded thermal insulation material, characterized in that: The steps include: (1) By weight, 60 to 100 parts of powder material, 2 to 30 parts of polymer binder, 5 to 20 parts of high temperature bonding aid and 0 to 10 parts of sunscreen are mixed in proportion to obtain a mixed raw material; (2) rolling the mixed raw materials to obtain the dry-molded thermal insulation material; The powder material is selected from one or both of fumed silica and white carbon black; The polymer binder is selected from one or more of PTFE, PVDF, PAN and PAA; The high temperature bonding aid is borax; The specific surface area of ​​the powder material is ≥200 m 2 / g.

2. The method for preparing the dry-molded thermal insulation material according to claim 1, characterized in that: The molecular weight of the polymer binder is ≥100,000.

3. The method for preparing the dry-molded thermal insulation material according to claim 1, characterized in that: The sunscreen agent is selected from one or both of silicon carbide and titanium dioxide; the particle size of the sunscreen agent is 1-5 μm.

4. The method for preparing the dry-molded thermal insulation material according to claim 1, characterized in that: The thickness of dry-molded thermal insulation materials is 50μm~20cm and the density is 0.1~0.5 g / cm 3 .

5. The method for preparing the dry-molded thermal insulation material according to claim 1, characterized in that: The mixing process of step (1) and / or the rolling process of step (2) are performed under heating, and the heating temperature is lower than 350° C.

6. The method for preparing the dry-molded thermal insulation material according to claim 1, characterized in that: Step (2) first extrude the mixed raw material through an extruder, and then roll-press the mixed raw material after extrusion; the mixed raw material is heated during the extrusion process, and the heating temperature is lower than 350°C.

7. The method for preparing the dry-molded thermal insulation material according to claim 1, characterized in that: In step (2), after rolling, a hydrophobic layer is coated on the surface of the dry-formed thermal insulation material; and / or the obtained dry-formed thermal insulation material is encapsulated with one of a polymer film and an aluminum-plastic film; and / or the obtained dry-formed thermal insulation material is compounded with other thermal insulation materials.

8. A dry-molded thermal insulation material, characterized in that: The method is prepared by the preparation method according to any one of claims 1 to 7.

9. An application of the dry-formed thermal insulation material as claimed in claim 8 or the dry-formed thermal insulation material prepared by the preparation method as claimed in any one of claims 1 to 7, characterized in that: Thermal protection or insulation materials for batteries, thermal insulation materials for electronic products, thermal insulation materials for buildings or thermal insulation materials for pipes.

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