Preparation method of nano-cellulose composite interlayer temperature-resistant flexible thermal insulation material

Abstract

The invention discloses a preparation method of a nano-cellulose composite interlayer temperature-resistant flexible thermal insulation material, which comprises the following steps: S1, preparing a temperature-resistant flexible thermal insulation material by using inorganic fibers and a binder A; s2, dispersing nano cellulose fiber reinforced silicon dioxide aerogel powder into an inorganic binder B to form coating slurry; and S3, coating the surface of the temperature-resistant flexible thermal insulation material with the coating slurry, laminating the same temperature-resistant flexible thermal insulation material, compounding, and drying to obtain the interlayer temperature-resistant flexible thermal insulation material. According to the preparation method provided by the invention, the reinforced structure nano material is introduced into the silicon dioxide aerogel to support a high-pore structure of the aerogel, and collapse of the pore structure is reduced after compounding, so that the temperature-resistant flexible thermal insulation material with relatively long service life and relatively good thermal insulation performance is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of special paper manufacturing, and in particular to a method for preparing a nano-cellulose composite interlayer temperature-resistant and flexible thermal insulation material. Background Art

[0002] Soft-tough insulation material is a flexible material with high thermal insulation performance. It can effectively prevent the transfer of heat and is widely used in aerospace, construction, electronics, automobile and other fields. In the field of aerospace, soft-tough insulation materials can be used for aircraft insulation layers, insulation blankets and other components, which can provide good thermal insulation protection and ensure flight safety. In the field of construction, soft-tough insulation materials can be applied to wallpaper, insulation film, roof insulation materials, etc., which can effectively reduce energy loss and improve the energy-saving performance of buildings. In the field of electronics, soft-tough insulation materials can be used for heat dissipation and heat insulation of electronic equipment to protect electronic components from overheating. In the automotive industry, soft-tough insulation materials can be applied to automotive insulation pads, insulation films and other components, which can reduce the heat conduction of the engine and improve the fuel efficiency of the vehicle. With the global emphasis on energy conservation, emission reduction and sustainable development, the research and development of soft-tough insulation materials has become a hot direction.

[0003] The thermal insulation principle of temperature-resistant flexible thermal insulation materials is mainly achieved through three mechanisms: reflection, absorption and radiation. First of all, the surface of temperature-resistant flexible thermal insulation materials has high reflectivity, which can reflect most of the thermal radiation back and reduce the absorption of heat. The interior of temperature-resistant flexible thermal insulation materials is filled with special thermal insulation materials, such as aerogel, glass fiber, etc., which can effectively absorb heat and reduce heat conduction. Temperature-resistant flexible thermal insulation materials can also dissipate the absorbed heat by radiation, thereby achieving good thermal insulation effect. Silica aerogel is a lightweight porous material. Due to its low density, high porosity, low thermal conductivity, etc., it is widely used in thermal insulation materials, adsorbents, catalyst carriers, and acoustic materials. However, the collapse of the silica aerogel structure is a problem, especially in high temperature, humidity or mechanical stress environments. The structure is more likely to collapse, which will lead to problems such as shortened service life and poor thermal insulation performance of the prepared flexible thermal insulation materials. Summary of the invention

[0004] The purpose of the present invention is to propose a method for preparing a nanocellulose composite interlayer soft and soft thermal insulation material in response to the problem that silica aerogel is prone to structural collapse, resulting in a short service life and poor thermal insulation performance of the soft and soft thermal insulation material. The prepared interlayer soft and soft thermal insulation material can avoid the problem of structural collapse of silica aerogel pores.

[0005] To achieve the above object, the present invention is implemented by the following technical solutions:

[0006] The present invention provides a method for preparing a nano-cellulose composite interlayer temperature-resistant and flexible thermal insulation material, the method comprising the following steps:

[0007] S1. Using inorganic fibers and binder A, a temperature-resistant and flexible thermal insulation material is prepared;

[0008] S2, dispersing nanocellulose fiber reinforced silica aerogel powder in inorganic binder B to form a coating slurry;

[0009] S3, coating the coating slurry on the surface of the soft and gentle thermal insulation material, and then laminating the soft and gentle thermal insulation material of the same kind, compounding, and drying to obtain a nano-cellulose composite interlayer soft and gentle thermal insulation material.

[0010] Specifically, the preparation method of the present invention introduces reinforcing structural nanomaterials into the silica aerogel to support the high porosity structure of the aerogel, reduces the collapse of the pore structure after composite, and then obtains a nano-cellulose composite interlayer temperature-resistant and flexible thermal insulation material with a long service life and good thermal insulation performance.

[0011] Furthermore, a method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material: the temperature-resistant and flexible thermal insulation material described in step S1 is prepared by pulping, papermaking, dehydration preforming and drying processes, which includes the following steps:

[0012] (1) Slurry preparation: adding the inorganic fiber to water and homogenizing until there are no flocs, then adding binder A, and continuing to mix evenly to obtain slurry A for screen papermaking;

[0013] (2) Papermaking: The slurry A is fed into a papermaking system for papermaking on the web, and the basis weight of the paper sheet is controlled;

[0014] (3) Dehydration preforming: After papermaking, suction dehydration preforming is carried out and pressed to a certain dryness;

[0015] (4) Drying: After dehydration and preforming, it is dried to the final dryness to obtain a temperature-resistant and flexible thermal insulation material.

[0016] Furthermore, a method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material: The method for preparing a temperature-resistant and flexible thermal insulation material comprises the following specific steps:

[0017] (1) Slurry preparation: adding the inorganic fibers to water and homogenizing until there are no flocs, then adding binder A and continuing to mix evenly, thereby obtaining slurry A for web papermaking with a concentration of 0.1 to 0.5 wt %;

[0018] Wherein, based on the mass of the inorganic fiber and the binder A being 100, the mass ratio of the inorganic fiber to the binder A in the slurry A is (90-95):(5-10); the inorganic fiber is selected from at least one of preoxidized silk fiber, glass fiber, basalt fiber, and mullite fiber; the binder A is a mixture of polyvinyl alcohol and water-based acrylic resin, and the mass ratio of the polyvinyl alcohol to the water-based acrylic resin is 1:(5-10);

[0019] (2) Papermaking: The slurry A is fed into a papermaking system for papermaking, and the paper weight is controlled to be 200 to 1000 g / m 2 ;

[0020] (3) Dehydration preforming: After papermaking, suction dehydration preforming is performed and pressed to a dryness of 25-40%;

[0021] (4) Drying: After dehydration preforming, far infrared pre-drying is first performed until the dryness of the material reaches more than 75%, and then microwave drying is performed until the dryness of the material reaches more than 92%, thereby obtaining a temperature-resistant and flexible thermal insulation material;

[0022] During far-infrared pre-drying, the material also needs to be heated to 120-180°C, and the microwave power used for microwave drying is 1500-4000W.

[0023] Furthermore, a method for preparing a nanocellulose composite interlayer temperature-resistant flexible thermal insulation material is provided: the inorganic binder B described in step S2 adopts a sodium silicate aqueous solution with a concentration of 10 to 25 wt%, and the ratio of the nanocellulose fiber (CNF) reinforced silica aerogel powder to the sodium silicate aqueous solution is 0.1 to 0.5 g / ml.

[0024] Furthermore, a method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material: the method for preparing the nanocellulose fiber reinforced silica aerogel powder comprises the following steps:

[0025] (1) dispersing nanocellulose fibers in a mixture of ethanol and water under stirring, adding ethyl orthosilicate after the dispersion is uniform, and mixing, adding ammonia water to adjust the pH value of the system to 9-10.5, and then aging at room temperature, and further aging at 30-45° C. to obtain a silicon dioxide wet gel;

[0026] (2) Using n-hexane to displace water and ethanol in the silica wet gel network, drying, and obtaining nanocellulose fiber reinforced silica aerogel powder.

[0027] Furthermore, a method for preparing a sandwich temperature-resistant flexible thermal insulation material: in step (1), the mass ratio of tetraethyl orthosilicate, ethanol and water is (4.5-6): (5-6.3): 1; the mass ratio of tetraethyl orthosilicate to nanocellulose fiber is (5-6): 1; the room temperature aging time is 2-3 days, and the aging time is 24-72 hours.

[0028] Furthermore, a method for preparing a nano-cellulose composite interlayer temperature-resistant flexible thermal insulation material: the drying method in step (2) is gradient heating drying under normal pressure, and the drying temperature is 60-150°C.

[0029] Further, a method for preparing a nanocellulose composite interlayer soft and soft thermal insulation material: step S3, coating the coating slurry on the surface of the soft and soft thermal insulation material, then stacking the same kind of soft and soft thermal insulation material, pressing and compounding, and drying to obtain the interlayer soft and soft thermal insulation material;

[0030] The coating amount of the coating slurry on the surface of the temperature-resistant flexible insulation material is 500-2000 ml / m 2 .

[0031] Beneficial effects of the present invention:

[0032] At present, the preparation method of the existing temperature-resistant flexible thermal insulation material is generally: impregnating silica gel into glass fiber cloth, and then using supercritical drying to obtain a silica aerogel composite material (i.e., the existing temperature-resistant flexible thermal insulation material). However, the composite material has a serious problem of powder shedding, which affects its use.

[0033] Compared with the prior art, the material prepared by the present invention uses silica aerogel as an interlayer, and the surface is covered with a heat-resistant inorganic fiber layer (temperature-resistant flexible thermal insulation material). The prepared interlayer temperature-resistant flexible thermal insulation material has good heat-resistant and heat-insulating properties, does not shed powder or hair, and has low production costs. The present invention introduces nanocellulose fibers into the silica aerogel to support the high-porous structure of the aerogel, which can reduce the collapse of the pore structure after compounding, thereby obtaining an interlayer temperature-resistant flexible thermal insulation material with a long service life and good thermal insulation properties.

[0034] The nanocellulose fiber reinforced silica aerogel powder added to the interlayer temperature-resistant flexible thermal insulation material obtained by the present invention is present as a filler in the interlayer of inorganic fibers, and sodium silicate is used as a binder between the layers. After drying, the interlayer force is strong, it is not easy to fall off, and no powder falls off when under pressure. The flexible thermal insulation material of the present invention has good strength and is not easy to delaminate, and has a good thermal insulation effect. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Unless otherwise specifically stated, the numerical values ​​set forth in these embodiments do not limit the scope of the present invention. The techniques and methods known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the techniques and methods should be considered as part of the specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values. The experimental methods for which specific conditions are not indicated in the following embodiments are usually measured according to national standards; if there is no corresponding national standard, it is carried out according to the general standard requirements or general methods.

[0037] Example 1

[0038] This embodiment 1 provides a method for preparing a nano-cellulose composite interlayer temperature-resistant flexible thermal insulation material, the method comprising the following specific steps:

[0039] S1. A temperature-resistant and flexible thermal insulation material is prepared by slurry preparation, papermaking, dehydration preforming, and drying;

[0040] S2, 50.0 g of nanocellulose fiber (CNF) reinforced silica aerogel powder (CNF@SiO2 AG-Ⅰ) was uniformly dispersed in 500 ml of 20.0 wt% sodium silicate aqueous solution (inorganic binder B) to form a coating slurry;

[0041] S3, uniformly coating the coating slurry on the surface of the soft and flexible thermal insulation material (coating 500 ml of the coating slurry on each square meter of the soft and flexible thermal insulation material), and then stacking the same kind of soft and flexible thermal insulation material, and then pressing and compounding, and microwave drying (microwave power 2000 W) until the dryness of the composite flexible material reaches more than 92%, that is, obtaining an interlayer soft and flexible thermal insulation material with a silica aerogel interlayer;

[0042] The method for preparing the temperature-resistant flexible thermal insulation material in step S1 comprises the following steps:

[0043] (1) Slurry preparation: Weigh 95.0 wt% of inorganic fibers (including 50.0 wt% of pre-oxidized silk fibers, 20.0 wt% of basalt fibers, and 25.0 wt% of mullite fibers) and 5.0 wt% of binder A (binder A is a mixture of polyvinyl alcohol and water-based acrylic resin, and the mass ratio of polyvinyl alcohol to water-based acrylic resin is 1:6. Polyvinyl alcohol adopts 1799 type, which can be dissolved in hot water and then added to the material for slurry preparation), add the above inorganic fibers to an appropriate amount of water and homogenize at a speed of 500 rpm until there are no flocs, then add binder A, continue to mix evenly, and dilute with water to obtain slurry A with a concentration of 0.1 wt%;

[0044] (2) Papermaking: The slurry A is fed into the papermaking system for papermaking and the paper weight is controlled to be 200 g / m 2 ;

[0045] (3) Dehydration preforming: After papermaking, suction dehydration preforming is performed and pressed to a dryness of 25%;

[0046] (4) Drying: After dehydration preforming, far infrared pre-drying is first performed (heating to 120°C is also required) until the material dryness reaches more than 75%, and then microwave drying (microwave power 2000W) is performed until the material dryness reaches more than 92%, thereby obtaining a temperature-resistant and flexible thermal insulation material;

[0047] The method for preparing nanocellulose fiber (CNF) reinforced silica aerogel powder in step S2 comprises the following steps:

[0048] (1) Under stirring, 15.0 g of nanocellulose fibers were dispersed in a mixture of 75.0 g of ethanol and 15.0 g of deionized water, and after being evenly dispersed, 80.0 g of tetraethyl orthosilicate (TEOS) was added and mixed, and ammonia water was added dropwise to adjust the pH of the system to 10.0, and then aged at room temperature for 3 days, and then aged at 45° C. for 24 hours to obtain a silicon dioxide wet gel;

[0049] (2) The water and ethanol in the silica wet gel network were replaced by n-hexane, and then dried at 60 °C, 80 °C, 100 °C, 120 °C, and 150 °C for 2 h, respectively, to obtain nanocellulose fiber reinforced silica aerogel powder, denoted as CNF@SiO2 AG-Ⅰ.

[0050] Example 2

[0051] This embodiment 2 provides a method for preparing a nano-cellulose composite interlayer temperature-resistant flexible thermal insulation material, the method comprising the following specific steps:

[0052] S1. A temperature-resistant and flexible thermal insulation material is prepared by slurry preparation, papermaking, dehydration preforming, and drying;

[0053] S2, 100.0 g of nanocellulose fiber (CNF) reinforced silica aerogel powder (CNF@SiO2 AG-Ⅱ) was uniformly dispersed in 800 ml of 25.0 wt% sodium silicate aqueous solution (inorganic binder B) to form a coating slurry;

[0054] S3, uniformly coating the coating slurry on the surface of the soft and flexible thermal insulation material (coating 800 ml of the coating slurry on each square meter of the soft and flexible thermal insulation material), and then stacking the same kind of soft and flexible thermal insulation material, and then pressing and compounding, and performing microwave drying (microwave power 3000 W) until the dryness of the composite flexible material reaches more than 92%, that is, obtaining an interlayer soft and flexible thermal insulation material with a silica aerogel interlayer;

[0055] The method for preparing the temperature-resistant flexible thermal insulation material in step S1 comprises the following steps:

[0056] (1) Slurry preparation: Weigh 95.0 wt% of inorganic fibers (including 40.0 wt% of pre-oxidized silk fibers, 25.0 wt% of glass fibers, and 30.0 wt% of mullite fibers) and 5.0 wt% of binder A (binder A is a mixture of polyvinyl alcohol and water-based acrylic resin, and the mass ratio of polyvinyl alcohol to water-based acrylic resin is 1:7), add the above inorganic fibers into an appropriate amount of water and homogenize at a speed of 500 rpm until there are no flocs, then add binder A, continue to mix evenly, and dilute with water to obtain slurry A with a concentration of 0.3 wt%;

[0057] (2) Papermaking: The slurry A is fed into the papermaking system for papermaking and the paper weight is controlled to be 300 g / m 2 ;

[0058] (3) Dehydration preforming: After papermaking, suction dehydration preforming is performed and pressed to a dryness of 30%;

[0059] (4) Drying: After dehydration preforming, far infrared pre-drying is first performed (heating to 120°C is also required) until the dryness of the material reaches more than 75%, and then microwave drying (microwave power 3000W) is performed until the dryness of the material reaches more than 92%, thereby obtaining a temperature-resistant and flexible thermal insulation material;

[0060] The method for preparing nanocellulose fiber (CNF) reinforced silica aerogel powder in step S2 comprises the following steps:

[0061] (1) Under stirring, 15.0 g of nanocellulose fibers were dispersed in a mixture of 90.0 g of ethanol and 15.0 g of deionized water, and after being evenly dispersed, 85.0 g of tetraethyl orthosilicate (TEOS) was added and mixed, and ammonia water was added dropwise to adjust the pH of the system to 9.5, and then aged at room temperature for 2 days, and then aged at 40° C. for 48 hours to obtain a silicon dioxide wet gel;

[0062] (2) The water and ethanol in the silica wet gel network were replaced by n-hexane, and then dried at 60 °C, 80 °C, 100 °C, 120 °C, and 150 °C for 2 h, respectively, to obtain nanocellulose fiber reinforced silica aerogel powder, which was recorded as CNF@SiO2 AG-Ⅱ.

[0063] Example 3

[0064] This embodiment 3 provides a method for preparing a nano-cellulose composite interlayer temperature-resistant flexible thermal insulation material, the method comprising the following specific steps:

[0065] S1. A temperature-resistant and flexible thermal insulation material is prepared by slurry preparation, papermaking, dehydration preforming, and drying;

[0066] S2, 250.0 g of nanocellulose fiber (CNF) reinforced silica aerogel powder (CNF@SiO2 AG-Ⅲ) was uniformly dispersed in 2000 ml of 15.0 wt% sodium silicate aqueous solution (inorganic binder B) to form a coating slurry;

[0067] S3, uniformly coating the coating slurry on the surface of the soft and flexible thermal insulation material (coating 2000 ml of the coating slurry on each square meter of the soft and flexible thermal insulation material), and then stacking the same kind of soft and flexible thermal insulation material, and then pressing and compounding, and performing microwave drying (microwave power 1500 W) until the dryness of the composite flexible material reaches more than 92%, that is, obtaining an interlayer soft and flexible thermal insulation material with a silica aerogel interlayer;

[0068] The method for preparing the temperature-resistant flexible thermal insulation material in step S1 comprises the following steps:

[0069] (1) Slurry preparation: 90.0 wt% of inorganic fibers (including 60.0 wt% of glass fibers and 30.0 wt% of mullite fibers) and 10.0 wt% of binder A (binder A is a mixture of polyvinyl alcohol and water-based acrylic resin, and the mass ratio of polyvinyl alcohol to water-based acrylic resin is 1:5) are weighed, the inorganic fibers are added to an appropriate amount of water and homogenized at a speed of 500 rpm until there are no flocs, and then binder A is added, and mixing is continued to be uniform, and water is added to dilute to obtain slurry A with a concentration of 0.1 wt%;

[0070] (2) Papermaking: The slurry A is fed into the papermaking system for papermaking and the paper weight is controlled to be 500 g / m 2 ;

[0071] (3) Dehydration preforming: After papermaking, suction dehydration preforming is performed and pressed to a dryness of 35%;

[0072] (4) Drying: After dehydration preforming, far infrared pre-drying is first performed (heating to 120°C is also required) until the dryness of the material reaches more than 75%, and then microwave drying (microwave power 1500W) is performed until the dryness of the material reaches more than 92%, thereby obtaining a temperature-resistant and flexible thermal insulation material;

[0073] The method for preparing nanocellulose fiber (CNF) reinforced silica aerogel powder in step S2 comprises the following steps:

[0074] (1) Under stirring, 15.0 g of nanocellulose fibers were dispersed in a mixture of 90.0 g of ethanol and 15.0 g of deionized water, and after being evenly dispersed, 85.0 g of tetraethyl orthosilicate (TEOS) was added and mixed, and ammonia water was added dropwise to adjust the pH of the system to 9.0, and then aged at room temperature for 2 days, and then aged at 35° C. for 72 hours to obtain a silicon dioxide wet gel;

[0075] (2) The water and ethanol in the silica wet gel network were replaced by n-hexane, and then dried at 60 °C, 80 °C, 100 °C, 120 °C, and 150 °C for 2 h, respectively, to obtain nanocellulose fiber reinforced silica aerogel powder, which was recorded as CNF@SiO2 AG-Ⅲ.

[0076] Comparative Example 1

[0077] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 uses unreinforced silica aerogel powder (SiO2AG) to replace CNF@SiO2 AG-Ⅰ in Example 1, and the other preparation conditions are the same as those in Example 1.

[0078] The preparation conditions of the reinforced silica aerogel powder and the unreinforced silica aerogel powder in the above Examples 1 to 3 and Comparative Example 1 are shown in the following table:

[0079]

[0080]

[0081] The diameter of the preoxidized silk fiber used in the above-mentioned Examples 1 to 3 and Comparative Example 1 is 5.0 to 15.0 μm and the length is 2.0 to 3.0 mm; the diameter of the glass fiber is 2.0 to 8.0 μm and the length is 3.0 to 6.0 mm; the diameter of the basalt fiber is 10.0 to 30.0 μm and the length is 3.0 to 7.0 mm; the diameter of the mullite fiber is 10.0 to 30.0 μm and the length is 6.0 to 15.0 mm.

[0082] Test: The performance of the flexible thermal insulation materials obtained in the above Examples 1 to 3 and Comparative Example 1 was tested, and the test results are shown in the following table:

[0083]

[0084] It can be seen from the above test results that the thermal conductivity of the flexible thermal insulation material prepared by the present invention is significantly lower, indicating that it has good thermal insulation performance. At the same time, the flexible thermal insulation material prepared by the present invention has a higher upper limit of use temperature and is a heat-resistant flexible thermal insulation material. It can be seen from the test results of Comparative Example 1 and Example 1 that the present invention not only avoids the structural collapse of the silica aerogel pores and improves its mechanical strength, prolongs its service life, but also improves its upper temperature limit and has good thermal insulation performance by introducing nanocellulose fibers into the silica aerogel to support the high porosity structure of the aerogel.

[0085] The above are preferred embodiments of the present invention and are only used to explain the present invention, not to limit the present invention. Any obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material, It is characterized in that The method comprises the following steps: S1. Using inorganic fibers and binder A, a temperature-resistant and flexible thermal insulation material is prepared; S2, dispersing nanocellulose fiber reinforced silica aerogel powder in inorganic binder B to form a coating slurry; S3, coating the coating slurry on the surface of the soft and gentle thermal insulation material, and then laminating the soft and gentle thermal insulation material of the same kind, compounding, and drying to obtain a nano-cellulose composite interlayer soft and gentle thermal insulation material.

2. A method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material according to claim 1, It is characterized in that The temperature-resistant and flexible thermal insulation material described in step S1 is prepared by slurry preparation, papermaking, dehydration preforming and drying processes, which includes the following specific steps: (1) Slurry preparation: adding the inorganic fiber to water and homogenizing until there are no flocs, then adding binder A, and continuing to mix evenly to obtain slurry A for screen papermaking; (2) Papermaking: The slurry A is fed into a papermaking system for papermaking on the web, and the basis weight of the paper sheet is controlled; (3) Dehydration preforming: After papermaking, suction dehydration preforming is carried out and pressed to a certain dryness; (4) Drying: After dehydration and preforming, it is dried to the final dryness to obtain a temperature-resistant and flexible thermal insulation material.

3. A method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material according to claim 2, It is characterized in that The preparation method of the temperature-resistant flexible thermal insulation material comprises the following specific steps: (1) Slurry preparation: adding the inorganic fibers to water and homogenizing until there are no flocs, then adding binder A and continuing to mix evenly, thereby obtaining slurry A for web papermaking with a concentration of 0.1 to 0.5 wt %; Wherein, based on the mass of the inorganic fiber and the binder A being 100, the mass ratio of the inorganic fiber to the binder A in the slurry A is (90-95):(5-10); the inorganic fiber is selected from at least one of preoxidized silk fiber, glass fiber, basalt fiber, and mullite fiber; the binder A is a mixture of polyvinyl alcohol and water-based acrylic resin, and the mass ratio of the polyvinyl alcohol to the water-based acrylic resin is 1:(5-10); (2) Papermaking: The slurry A is fed into a papermaking system for papermaking, and the paper weight is controlled to be 200 to 1000 g / m 2 ; (3) Dehydration preforming: After papermaking, suction dehydration preforming is performed and pressed to a dryness of 25-40%; (4) Drying: After dehydration preforming, far infrared pre-drying is first performed until the dryness of the material reaches more than 75%, and then microwave drying is performed until the dryness of the material reaches more than 92%, thereby obtaining a temperature-resistant and flexible thermal insulation material; During far-infrared pre-drying, the material also needs to be heated to 120-180°C, and the microwave power used for microwave drying is 1500-4000W.

4. The method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material according to claim 1, It is characterized in that The inorganic binder B in step S2 is a sodium silicate aqueous solution with a concentration of 10-25 wt %, and the ratio of the nano-cellulose fiber reinforced silica aerogel powder to the sodium silicate aqueous solution is 0.1-0.5 g / ml.

5. A method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material according to claim 1 or 4, It is characterized in that The method for preparing the nanocellulose fiber reinforced silica aerogel powder comprises the following steps: (1) dispersing nanocellulose fibers in a mixture of ethanol and water under stirring, adding ethyl orthosilicate after the dispersion is uniform, and mixing, dropping ammonia water to adjust the pH value of the system to 9-10.5, and then aging at room temperature, and further aging at 30-45° C. to obtain a silicon dioxide wet gel; (2) Using n-hexane to displace water and ethanol in the silica wet gel network, drying, and obtaining nanocellulose fiber reinforced silica aerogel powder.

6. A method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material according to claim 5, It is characterized in that In step (1), the mass ratio of tetraethyl orthosilicate, ethanol and water is (4.5-6): (5-6.3): 1; the mass ratio of tetraethyl orthosilicate to nanocellulose fiber is (5-6): 1; the room temperature aging time is 2-3 days, and the aging time is 24-72 hours.

7. The method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material according to claim 5, It is characterized in that The drying method in step (2) is to perform gradient temperature drying under normal pressure, and the drying temperature is 60-150°C.

8. The method for preparing a nanocellulose composite interlayer temperature-resistant and flexible thermal insulation material according to claim 1, It is characterized in that Step S3, coating the coating slurry on the surface of the soft and gentle thermal insulation material, and then laminating the same soft and gentle thermal insulation material, pressing and compounding, and drying to obtain a nano-cellulose composite interlayer soft and gentle thermal insulation material; The coating amount of the coating slurry on the surface of the temperature-resistant flexible insulation material is 500-2000 ml / m 2 .

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