Graphene oxide modified ceramic protective heat-insulating film and preparation method thereof

Abstract

The invention discloses a graphene oxide modified ceramic protective heat-insulating film and a preparation method thereof.The protective heat-insulating film is prepared from, by mass, 100-200 parts of base rubber, 1-5 parts of a graphene oxide modifier, 30-70 parts of ceramic flame-retardant filler, 5-20 parts of heat-insulating filler and 1-3 parts of auxiliaries through a blade coating technology, and the protective heat-insulating film is prepared from, by mass, 100-200 parts of base rubber, 1-5 parts of a graphene oxide modifier, 30-70 parts of ceramic flame-retardant filler, 5-20 parts of heat-insulating filler and 1-3 parts of auxiliaries. The graphene oxide modifier is graphene oxide coated with nano silicon carbide, and the auxiliary agent comprises a directional agent. By using the graphene oxide modifier, the tensile strength of the protective heat-insulating film can be improved, a thinner film material can achieve stronger protective heat-insulating performance due to the fact that no fiber material is adopted, the space utilization rate of the film material in practical application can be improved, and the material cost can be reduced. According to the preparation method disclosed by the invention, the graphene oxide is preferentially arranged parallel to the surface of the coating through a blade coating process, so that the tensile resistance and the heat-insulating property of the prepared protective heat-insulating film can be effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of fireproof and heat-insulating materials, and in particular relates to a graphene oxide-modified ceramic protective and heat-insulating film and a preparation method thereof. Background Art

[0002] The increase in single-cell capacity has been a key trend in recent lithium-ion battery technology development. Cylindrical cell capacity has increased more than fivefold, from the 18650 cells initially used by Tesla, to the 21700 cells, and finally to the latest 4680 cells. Ternary battery cells, such as the widely adopted soft-pack cells (primarily used by European automakers) and prismatic cells (mostly used by domestic new energy vehicles), offer even greater single-cell capacities, typically exceeding 0.5 kWh. Such large single-cell capacities place extremely high demands on thermal runaway protection materials. These requirements require excellent compressibility, high insulation, resistance to high mechanical shock, resistance to flames of 1000°C to 1400°C, and the ability to prevent high-temperature transmission to adjacent cells. Existing materials such as mica, super cotton, aerogel, and their combinations no longer meet these demands.

[0003] Ceramic polymer membranes are a type of heat-insulating material that is very suitable for new energy lithium batteries. By using a combination of different fillers and base glues, good compressibility, insulation, heat resistance and thermal insulation performance can be achieved. Existing technologies often obtain the impact resistance of ceramic polymer membranes by adding chopped fibers or compounding with fiber layers. The problem is that: on the one hand, the addition of chopped fibers will deteriorate the fluidity of the raw materials and make forming difficult. Compounding with the fiber layer greatly thickens the overall membrane material, and the thickness usually reaches more than 3mm, while the thickness without chopped glass fibers is generally around 2mm. The addition of chopped glass fibers reduces the performance of the membrane material per unit thickness, wasting space inside the vehicle. On the other hand, when using fibers as modified materials, there is a risk of fiber residue and fiber shedding during processing, affecting the safety of the material in vehicle body construction. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a graphene oxide modified ceramic protective thermal insulation film with small thickness and good thermal insulation performance and a preparation method thereof.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A graphene oxide-modified ceramic protective heat-insulating film is produced through a scraping process from the following raw materials in parts by mass: 100 to 200 parts of a base glue, 1 to 5 parts of a graphene oxide modifier, 30 to 70 parts of a ceramic flame-retardant filler, 5 to 20 parts of a heat-insulating filler, and 1 to 3 parts of an auxiliary agent; the graphene oxide modifier is graphene oxide coated with nano-silicon carbide, and the graphene oxide-modified ceramic protective heat-insulating film has a thickness of 1 to 3 mm; the auxiliary agent includes an orienting agent.

[0007] The above-mentioned graphene oxide modified ceramic protective insulation film, preferably, the graphene oxide is multilayer graphene oxide, the thickness of the multilayer graphene oxide is 1nm to 5nm, and the sheet diameter of the multilayer graphene oxide is 3μm to 10μm; the mass of the nano-silicon carbide is 20% to 30% of the mass of the multilayer graphene oxide, and the average particle size of the nano-silicon carbide is 70nm to 100nm.

[0008] The above-mentioned graphene oxide modified ceramic protective insulation film, preferably, the auxiliary agent also includes a coupling agent, a wetting agent and a dispersant, and the mass ratio of the coupling agent, wetting agent, dispersant and orienting agent is 5-6:1:1:1.5-2.5; the coupling agent is an organosilicon coupling agent, the wetting agent is an organosilicon wetting agent, the dispersant is an organosilicon dispersant, and the orienting agent is a cellulose orienting agent.

[0009] In the above-mentioned graphene oxide modified ceramic protective heat-insulating film, preferably, the heat-insulating filler is at least one of soda lime borosilicate glass hollow microspheres, zirconium oxide hollow microspheres, zirconium oxide porous microspheres, aluminum oxide hollow microspheres and aluminum oxide porous microspheres.

[0010] The above-mentioned graphene oxide modified ceramic protective insulation film, preferably, the thermal insulation filler is formed by mixing soda lime borosilicate glass hollow microspheres and metal oxide microspheres in a volume ratio of 50 to 70:20 to 40, the diameters of the soda lime borosilicate glass hollow microspheres and the metal oxide microspheres are both less than or equal to 50 μm, and the metal oxide microspheres are at least one of zirconia hollow microspheres, zirconia porous microspheres, alumina hollow microspheres and alumina porous microspheres.

[0011] The above-mentioned graphene oxide modified ceramic protective heat-insulating film, preferably, the base rubber is at least one of methyl vinyl silicone rubber, methyl silicone rubber and methyl phenyl vinyl silicone rubber.

[0012] The above-mentioned graphene oxide modified ceramic protective heat-insulating film, preferably, the ceramic flame-retardant filler includes organic montmorillonite, wollastonite powder, fumed white carbon black, aluminum hydroxide powder, boron oxide powder, aluminum oxide powder, mica powder and silicon carbide powder.

[0013] The above-mentioned graphene oxide modified ceramic protective insulation film preferably comprises 5 to 20 parts of the organic montmorillonite, 2 to 10 parts of the wollastonite powder, 10 to 50 parts of the fumed white carbon black, 10 to 50 parts of the aluminum hydroxide powder, 1 to 5 parts of the boron oxide powder, 1 to 10 parts of the aluminum oxide powder, 5 to 10 parts of the mica powder, and 1 to 10 parts of the silicon carbide powder.

[0014] As a general technical concept, the present invention also provides a method for preparing the above-mentioned graphene oxide-modified ceramic protective thermal insulation film, comprising the following steps:

[0015] (1) mixing the ceramicizable flame retardant filler, the thermal insulation filler, the graphene oxide modifier and the additive in parts by mass with the base rubber under stirring conditions to obtain a mixed material;

[0016] (2) applying the mixed material on a substrate by a scraping process to obtain a coating;

[0017] (3) drying and vulcanizing the coating and then rewinding it, and then unwinding it for the next coating;

[0018] (4) Repeat steps (2) and (3) until the target thickness is reached.

[0019] The preparation method of the above-mentioned graphene oxide modified ceramic protective insulation film, in step (1), the mixing process is diluted with a solvent to adjust the viscosity between 20,000 cps and 30,000 cps, the solvent is a mixed solvent of xylene, methanol and solvent oil, and the mass ratio of xylene, methanol and solvent oil is 6 to 8:2:1; in steps (2) and (3), the coating thickness of each scraping is ≤0.2 mm.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) In response to the technical defects of the current fiber-containing new energy lithium battery fireproof and heat-insulating materials, the present invention provides a graphene oxide-modified ceramic protective heat-insulating film, which is prepared by specific mass parts of base glue, graphene oxide modifier, ceramic flame-retardant filler, heat-insulating filler, and auxiliary agent, wherein the graphene oxide modifier is graphene oxide coated with nano-silicon carbide, and the auxiliary agent includes a directional agent. The applicant conducted an in-depth study on the composition of the ceramic polymer film used in a type of heat-insulating material for existing new energy lithium batteries, abandoned the traditional thinking of using fiber additives, and creatively used graphene oxide modifier to modify the heat-insulating material. Based on the special planar layered structure of graphene oxide, when it is added to the membrane material to form a coating, under the action of the directional agent and the scraping force, it will naturally tend to be arranged parallel to the membrane plane, which is more conducive to enhancing the tensile and impact resistance of the membrane material. Furthermore, the graphene oxide modifier of the present invention is specifically graphene oxide with nano-silicon carbide coated on the surface. After encountering high temperature, nano-silicon carbide will form a protective oxide film on the surface of graphene oxide, improving the high-temperature oxidation resistance of graphene oxide, so that the protective thermal insulation film can still maintain high mechanical properties through the modification of graphene oxide after the ceramic reaction occurs. At the same time, coating the graphene oxide surface with nano-silicon carbide can effectively improve the dispersion uniformity of graphene oxide, thereby uniformly improving the mechanical properties of the film material and reducing the risk of local damage. The modified graphene oxide in the present invention also has good insulation properties. While strengthening the ceramic-resistant thermal insulation film material, it can form a synergistic effect with ceramic-resistant flame retardant fillers and thermal insulation fillers. In summary, the present invention can improve the tensile strength of the protective thermal insulation film through the use of graphene oxide modifier, thereby improving the impact resistance. Since no fiber material is used, the safety hazards and processing difficulties caused by fiber residue or shedding are avoided, and the thickness problem introduced by the fiber layer is avoided. The present invention can use thinner film materials to achieve stronger protective thermal insulation performance, which is beneficial to improving the space utilization of the film material in practical applications, such as reducing the requirements of the protective thermal insulation film for the space inside the vehicle, and reducing material costs.

[0022] (2) The protective heat-insulating film of the present invention has good flexibility and can better fit the uneven surface of the workpiece. By optimizing the amount of each component to 100 to 200 parts of base glue, 1 to 5 parts of graphene oxide modifier, 30 to 70 parts of ceramic flame retardant filler, 5 to 20 parts of heat-insulating filler, and 1 to 3 parts of auxiliary agent, the protective heat-insulating film of the present invention can be hot-pressed and reshaped to achieve a better fitting effect.

[0023] (3) The graphene oxide modified ceramic protective thermal insulation film of the present invention will undergo a ceramic reaction when exposed to high temperature, forming a hard ceramic phase layer in the high temperature area, which prevents the high temperature from further damaging and diffusing through the protective thermal insulation film layer. Nano-silicon carbide forms an oxide film coated on the surface of the layered graphene oxide. The graphene oxide coated with nano-silicon carbide is arranged in parallel in the protective thermal insulation film, which greatly improves the anti-burn-through performance of the film material. According to tests, the protective thermal insulation film of the present invention can ensure that the film layer will not be penetrated by flames within 30 minutes when the surface temperature does not exceed 1200°C. At the same time, under the condition of free heat dissipation on the cold surface, the cold surface temperature can be less than 350°C with a film thickness of 1mm.

[0024] (4) The preparation method of the graphene oxide modified ceramic protective heat insulation film of the present invention is to make the graphene oxide preferentially parallel to the coating direction under the cooperation of the directional agent through the scraping process (see Figure 1 ), thereby effectively improving the tensile strength of the resulting protective thermal insulation film. The parallel arrangement of graphene oxide prevents the formation of numerous through-holes after the graphene oxide is completely oxidized following a high-temperature ceramicization reaction in subsequent applications. The present invention utilizes a doctor blade coating process to ensure coating accuracy, smoothness, and the parallel arrangement of graphene oxide, while also effectively controlling the thickness of the film product. Therefore, the protective thermal insulation film produced by the preparation method of the present invention can achieve stronger protective thermal insulation performance at a thinner thickness without the presence of fiber additives.

[0025] When the graphene oxide modified ceramic protective insulation film prepared by the method of the present invention is formed, the ceramic material of the same thickness is coated on both sides of the base material, so that the front and back sides of the film layer have uniform properties, which can reduce the operational complexity during the application process and prevent misalignment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a scanning electron microscope image of the graphene oxide-modified ceramic protective thermal insulation film prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but the scope of protection of the present invention is not limited thereby. The materials and instruments used in the following examples are all commercially available.

[0028] Example 1:

[0029] A graphene oxide modified ceramic protective heat-insulating film of the present invention is made of the following raw materials in parts by mass: 100 parts of base glue, 1 part of graphene oxide modifier, 50 parts of ceramic flame-retardant filler, 5 parts of heat-insulating filler, and 1 part of auxiliary agent.

[0030] In this embodiment, the base rubber is methyl vinyl silicone rubber.

[0031] In this embodiment, the graphene oxide is a multilayer graphene oxide with a thickness of 3 nm and a sheet diameter (referring to the maximum length of the sheet material) of 5 μm.

[0032] In this embodiment, the thermal insulation filler is GS40 soda lime borosilicate glass hollow microspheres produced by Sinosteel New Materials.

[0033] In this embodiment, the auxiliary agent is obtained by mixing Chenguang New Materials KH550 silane coupling agent, German Digo 245 siloxane wetting agent, German Digo GS650 dispersant and Eastman CAB 381-0.5 directing agent in a mass ratio of 5:1:1:2.

[0034] In other embodiments, the siloxane coupling agent may be KH570 from Chenguang New Materials or other siloxane coupling agents with similar functions; the siloxane wetting agent may be German Digo 270, Digo 4100 or other siloxane wetting agents with similar functions; the dispersant may be German Digo 652D dispersant.

[0035] The solvent in this embodiment is a mixed solvent of xylene, methanol and solvent oil. The mass ratio of xylene, methanol and solvent oil is 7:2:1. The solvent oil is No. 120 solvent oil. The solvent is an optional material in the process and no residue remains in the final product.

[0036] The graphene oxide modifier of this embodiment is obtained by coating the above-mentioned multilayer graphene oxide and nano-silicon carbide powder, wherein the mass of the nano-silicon carbide powder is 20% of the mass of the multilayer graphene oxide, the average particle size of the nano-silicon carbide powder is 90 nm, and the coating equipment used is a stirring solid coating machine, and the coating time is 30 min.

[0037] The ceramic flame retardant filler of this embodiment includes, by mass, 10 parts of organic montmorillonite, 8 parts of wollastonite powder, 10 parts of fumed silica, 20 parts of aluminum hydroxide powder, 5 parts of boron oxide powder, 5 parts of aluminum oxide powder, 10 parts of mica powder and 5 parts of silicon carbide powder.

[0038] A method for preparing a graphene oxide-modified ceramic protective thermal insulation film according to this embodiment comprises the following steps:

[0039] (1) Weigh a total of 50 kg of materials according to the above mass parts, add the above-mentioned ceramic flame retardant filler, thermal insulation filler, graphene oxide modifier and solvent containing additives to the base rubber in sequence under stirring conditions, use an open mill to fully mix at room temperature, and dilute with solvent during the mixing process to adjust the viscosity to between 20,000 cps and 30,000 cps;

[0040] (2) using a scraping coating process to form the mixture, specifically, using a scraper coater to evenly coat the mixed material refined in step (1) on the surface of the fluoroplastic release film;

[0041] (3) The coating after scraping is dried and vulcanized in a drying tunnel and then rolled up, and then unrolled for the next scraping;

[0042] (4) repeating steps (2) and (3) until the target thickness is reached, and then cutting into a certain shape and size on a slitting machine to obtain the product;

[0043] In steps (2) and (3), the coating thickness of each scraping should be controlled to be ≤0.2 mm.

[0044] Figure 1 This is a scanning electron microscope image of the graphene oxide modified ceramic protective heat insulation film obtained in this embodiment. Figure 1 It can be seen that graphene oxide and other fillers are basically arranged parallel to the membrane surface. Since graphene oxide has a planar layered structure, it tends to be arranged parallel to the membrane plane under the combined action of the orienting agent and the external force of the scraper.

[0045] This embodiment uses a comma blade coating method, which is suitable for coating liquids with a viscosity of more than 5000 cps and fluidity, and is particularly suitable for liquids with certain solid fillers. The coating thickness is adjustable and has a certain coating accuracy. During the coating process, the blade force is parallel to the membrane surface, which can better ensure that the graphene in the oxygen product is arranged parallel to the membrane plane.

[0046] The graphene oxide-modified ceramic protective thermal insulation film prepared in this embodiment has a thickness of 1.0 mm and a tensile strength of 5.5 MPa. In a flame spraying test, when the flame surface temperature does not exceed 1200°C, the film layer can be guaranteed not to be penetrated by the flame within 30 minutes. At the same time, the temperature is less than 350°C under the condition of free heat dissipation on the cold surface.

[0047] Example 2:

[0048] A graphene oxide modified ceramic protective heat-insulating film of the present invention is made of the following raw materials in parts by mass: 100 parts of base glue, 2 parts of graphene oxide modifier, 60 parts of ceramic flame-retardant filler, 10 parts of heat-insulating filler, and 1 part of auxiliary agent.

[0049] In this embodiment, the base rubber is methylphenyl vinyl silicone rubber.

[0050] In this embodiment, the graphene oxide is a multilayer graphene oxide with a thickness of 5 nm and a sheet diameter (referring to the maximum length of the sheet material) of 7 μm.

[0051] In this embodiment, the thermal insulation filler is GS32 soda lime borosilicate glass hollow microspheres produced by Sinosteel New Materials.

[0052] In this embodiment, the auxiliary agent is obtained by mixing Chenguang New Materials KH550 silane coupling agent, German Digo 4100 siloxane wetting agent, German Digo GS650 dispersant and Eastman CAB 381-0.5 directing agent in a mass ratio of 6:1:1:2.

[0053] The solvent in this embodiment is a mixed solvent of xylene, methanol and solvent oil. The mass ratio of xylene, methanol and solvent oil is 7:2:1. The solvent oil is No. 120 solvent oil. The solvent is an optional material in the process and no residue remains in the final product.

[0054] The graphene oxide modifier of this embodiment is obtained by coating the above-mentioned multilayer graphene oxide and nano-silicon carbide powder, wherein the mass of the nano-silicon carbide powder is 25% of the mass of the multilayer graphene oxide, the average particle size of the nano-silicon carbide powder is 90 nm, and the coating equipment used is a stirring solid coating machine, and the coating time is 30 min.

[0055] The ceramic flame retardant filler of this embodiment includes, by mass, 10 parts of organic montmorillonite, 8 parts of wollastonite powder, 10 parts of fumed silica, 20 parts of aluminum hydroxide powder, 5 parts of boron oxide powder, 5 parts of aluminum oxide powder, 10 parts of mica powder and 5 parts of silicon carbide powder.

[0056] A method for preparing a graphene oxide-modified ceramic protective thermal insulation film according to this embodiment comprises the following steps:

[0057] (1) Weigh a total of 50 kg of materials according to the above mass parts, add the above-mentioned ceramic flame retardant filler, thermal insulation filler, graphene oxide modifier and solvent containing additives to the base rubber in sequence under stirring conditions, use an open mill to fully mix at room temperature, and dilute with solvent during the mixing process to adjust the viscosity to between 20,000 cps and 30,000 cps;

[0058] (2) using a scraping coating process to form the mixture, specifically, using a scraper coater to evenly coat the mixed material refined in step (1) on the surface of the fluoroplastic release film;

[0059] (3) The coating after scraping is dried and vulcanized in a drying tunnel and then rolled up, and then unrolled for the next scraping;

[0060] (4) repeating steps (2) and (3) until the target thickness is reached, and then cutting into a certain shape and size on a slitting machine to obtain the product;

[0061] In steps (2) and (3), the coating thickness of each scraping should be controlled to be ≤0.2 mm.

[0062] This embodiment uses a comma blade coating method, which is suitable for coating liquids with a viscosity of more than 5000 cps and fluidity, and is particularly suitable for liquids with certain solid fillers. The coating thickness is adjustable and has a certain coating accuracy. During the coating process, the blade force is parallel to the membrane surface, which can better ensure that the graphene in the oxygen product is arranged parallel to the membrane plane.

[0063] The graphene oxide-modified ceramic protective thermal insulation film prepared in this embodiment has a thickness of 1.6 mm and a tensile strength of 5.8 MPa. In a flame spraying test, when the flame surface temperature does not exceed 1200°C, the film layer can be guaranteed not to be penetrated by the flame within 30 minutes. At the same time, the temperature is less than 350°C under the condition of free heat dissipation on the cold surface.

[0064] Example 3:

[0065] A graphene oxide modified ceramic protective heat-insulating film of the present invention is made of the following raw materials in parts by mass: 100 parts of base glue, 3 parts of graphene oxide modifier, 50 parts of ceramic flame-retardant filler, 6 parts of heat-insulating filler, and 2 parts of additive.

[0066] In this embodiment, the base rubber is methyl vinyl silicone rubber.

[0067] In this embodiment, the graphene oxide is a multilayer graphene oxide with a thickness of 3 nm and a sheet diameter (referring to the maximum length of the sheet material) of 5 μm.

[0068] In this embodiment, the thermal insulation filler is GS46 soda lime borosilicate glass hollow microspheres produced by Sinosteel New Materials.

[0069] In this embodiment, the auxiliary agent is obtained by mixing Chenguang New Materials KH550 silane coupling agent, German Digo 270 siloxane wetting agent, German Digo 652D dispersant and Eastman CAB 381-0.5 directing agent in a mass ratio of 5:1:1:2.

[0070] The solvent in this embodiment is a mixed solvent of xylene, methanol and solvent oil. The mass ratio of xylene, methanol and solvent oil is 7:2:1. The solvent oil is No. 120 solvent oil. The solvent is an optional material in the process and no residue remains in the final product.

[0071] The graphene oxide modifier of this embodiment is obtained by coating the above-mentioned multilayer graphene oxide and nano-silicon carbide powder, wherein the mass of the nano-silicon carbide powder is 30% of the mass of the multilayer graphene oxide, the average particle size of the nano-silicon carbide powder is 90 nm, and the coating equipment used is a stirring solid coating machine, and the coating time is 30 minutes.

[0072] The ceramic flame retardant filler of this embodiment includes, by mass, 10 parts of organic montmorillonite, 8 parts of wollastonite powder, 10 parts of fumed silica, 20 parts of aluminum hydroxide powder, 5 parts of boron oxide powder, 5 parts of aluminum oxide powder, 10 parts of mica powder and 5 parts of silicon carbide powder.

[0073] A method for preparing a graphene oxide-modified ceramic protective thermal insulation film according to this embodiment comprises the following steps:

[0074] (1) Weigh a total of 50 kg of materials according to the above mass parts, add the above-mentioned ceramic flame retardant filler, thermal insulation filler, graphene oxide modifier and solvent containing additives to the base rubber in sequence under stirring conditions, use an open mill to fully mix at room temperature, and dilute with solvent during the mixing process to adjust the viscosity to between 20,000 cps and 30,000 cps;

[0075] (2) using a scraping coating process to form the mixture, specifically, using a scraper coater to evenly coat the mixed material refined in step (1) on the surface of the fluoroplastic release film;

[0076] (3) The coating after scraping is dried and vulcanized in a drying tunnel and then rolled up, and then unrolled for the next scraping;

[0077] (4) repeating steps (2) and (3) until the target thickness is reached, and then cutting into a certain shape and size on a slitting machine to obtain the product;

[0078] In steps (2) and (3), the coating thickness of each scraping should be controlled to be ≤0.2 mm.

[0079] This embodiment uses a comma blade coating method, which is suitable for coating liquids with a viscosity of more than 5000 cps and fluidity, and is particularly suitable for liquids with certain solid fillers. The coating thickness is adjustable and has a certain coating accuracy. During the coating process, the blade force is parallel to the membrane surface, which can better ensure that the graphene in the oxygen product is arranged parallel to the membrane plane.

[0080] The graphene oxide-modified ceramic protective thermal insulation film prepared in this embodiment has a thickness of 1.8 mm and a tensile strength of 6.1 MPa. In a flame spraying test, when the flame surface temperature does not exceed 1200°C, the film layer can be guaranteed not to be penetrated by the flame within 30 minutes. At the same time, the temperature is less than 350°C under the condition of free heat dissipation on the cold surface.

[0081] Comparative Example 1:

[0082] A graphene oxide-modified ceramic protective thermal insulation film is essentially the same as Example 1, differing only in that the graphene oxide modifier is graphene oxide that has not been coated with nano-silicon carbide powder. The resulting graphene oxide-modified ceramic protective thermal insulation film has a thickness of 1.0 mm and a tensile strength of 3.2 MPa. In a flame spray test, the film was shown to be impervious to flame penetration for 30 minutes, provided the flame surface temperature did not exceed 1200°C. Furthermore, the film maintained a temperature of no less than 370°C under conditions of free heat dissipation from the cold surface.

[0083] Comparative Example 2:

[0084] A graphene oxide-modified ceramic protective thermal insulation film is substantially the same as Example 1, except that no glass hollow microspheres are added. The obtained graphene oxide-modified ceramic protective thermal insulation film has a thickness of 1.0 mm and a tensile strength of 5.2 MPa. In a flame spraying test, the film layer can be guaranteed not to be penetrated by the flame within 30 minutes when the flame surface temperature does not exceed 1200°C. At the same time, the temperature is not less than 400°C under the condition of free heat dissipation on the cold surface.

[0085] Comparative Example 3:

[0086] A graphene oxide-modified, ceramic-like protective and thermal insulation film is essentially the same as Example 1, differing only in that no directing agent is used in the additive. The resulting graphene oxide-modified, ceramic-like protective and thermal insulation film has a thickness of 1.0 mm and a tensile strength of 4.3 MPa. In a flame spray test, the film was shown to be impervious to flame penetration for 30 minutes, provided the flame surface temperature did not exceed 1200°C. Furthermore, the film maintained a temperature of no less than 380°C under conditions of free heat dissipation from the cold surface.

[0087] The above description is only a preferred embodiment of the present invention and does not constitute any formal limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the spirit and technical solution of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A graphene oxide modified ceramic protective thermal insulation film, characterized in that: The protective thermal insulation film is made from the following raw materials in parts by mass through a scraping process: 100 to 200 parts of base glue, 1 to 5 parts of graphene oxide modifier, 30 to 70 parts of ceramic flame retardant filler, 5 to 20 parts of thermal insulation filler, and 1 to 3 parts of auxiliary agent; the graphene oxide modifier is graphene oxide coated with nano-silicon carbide, and the thickness of the graphene oxide-modified ceramic protective thermal insulation film is 1 mm to 3 mm; the auxiliary agent includes a directional agent.

2. The graphene oxide modified ceramic protective thermal insulation film according to claim 1, characterized in that: The graphene oxide is multilayer graphene oxide, the thickness of the multilayer graphene oxide is 1nm to 5nm, and the sheet diameter of the multilayer graphene oxide is 3μm to 10μm; the mass of the nano-silicon carbide is 20% to 30% of the mass of the multilayer graphene oxide, and the average particle size of the nano-silicon carbide is 70nm to 100nm.

3. The graphene oxide modified ceramic protective thermal insulation film according to claim 1, characterized in that: The auxiliary agent also includes a coupling agent, a wetting agent and a dispersant, and the mass ratio of the coupling agent, the wetting agent, the dispersant and the orienting agent is 5-6:1:1:1.5-2.5; the coupling agent is an organosilicon coupling agent, the wetting agent is an organosilicon wetting agent, the dispersant is an organosilicon dispersant, and the orienting agent is a cellulose orienting agent.

4. The graphene oxide modified ceramic protective thermal insulation film according to claim 1, characterized in that: The heat-insulating filler is at least one of soda lime borosilicate glass hollow microspheres, zirconium oxide hollow microspheres, zirconium oxide porous microspheres, aluminum oxide hollow microspheres and aluminum oxide porous microspheres.

5. The graphene oxide modified ceramic protective thermal insulation film according to claim 4, characterized in that: The thermal insulation filler is formed by mixing soda lime borosilicate glass hollow microspheres and metal oxide microspheres in a volume ratio of 50 to 70:20 to 40. The diameters of the soda lime borosilicate glass hollow microspheres and the metal oxide microspheres are both less than or equal to 50 μm. The metal oxide microspheres are at least one of zirconia hollow microspheres, zirconia porous microspheres, alumina hollow microspheres and alumina porous microspheres.

6. The graphene oxide modified ceramic protective thermal insulation film according to claim 1, characterized in that: The base rubber is at least one of methyl vinyl silicone rubber, methyl silicone rubber and methyl phenyl vinyl silicone rubber.

7. The graphene oxide modified ceramic protective thermal insulation film according to claim 6, characterized in that: The ceramicizable flame retardant filler comprises organic montmorillonite, wollastonite powder, fumed white carbon black, aluminum hydroxide powder, boron oxide powder, aluminum oxide powder, mica powder and silicon carbide powder.

8. The graphene oxide modified ceramic protective thermal insulation film according to claim 7, characterized in that: The organic montmorillonite is 5 to 20 parts, the wollastonite powder is 2 to 10 parts, the fumed white carbon is 10 to 50 parts, the aluminum hydroxide powder is 10 to 50 parts, the boron oxide powder is 1 to 5 parts, the aluminum oxide powder is 1 to 10 parts, the mica powder is 5 to 10 parts, and the silicon carbide powder is 1 to 10 parts.

9. A method for preparing a graphene oxide modified ceramic protective thermal insulation film according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) mixing the ceramicizable flame retardant filler, the thermal insulation filler, the graphene oxide modifier and the additive in parts by mass with the base rubber under stirring conditions to obtain a mixed material; (2) applying the mixed material on a substrate by a scraping process to obtain a coating; (3) drying and vulcanizing the coating and then rewinding it, and then unwinding it for the next coating; (4) Repeat steps (2) and (3) until the target thickness is reached.

10. The method for preparing the graphene oxide modified ceramic protective thermal insulation film according to claim 9, characterized in that: In step (1), the mixture is diluted with a solvent to adjust the viscosity to between 20,000 cps and 30,000 cps, wherein the solvent is a mixed solvent of xylene, methanol and solvent oil, and the mass ratio of xylene, methanol and solvent oil is 6 to 8:2:1; in steps (2) and (3), the coating thickness of each scraping is ≤0.2 mm.

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