CN115537137B

CN115537137B - Ceramic silicon rubber compound, ceramic silicon rubber and preparation method and application thereof

Info

Publication number: CN115537137B
Application number: CN202110729683.4A
Authority: CN
Inventors: 张志杰; 陈子琪; 谭永霞; ***
Original assignee: Institute of Chemistry CAS
Current assignee: Institute of Chemistry CAS
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2023-09-12
Anticipated expiration: 2041-06-29
Also published as: CN115537137A

Abstract

The invention discloses a ceramic silicon rubber compound, ceramic silicon rubber and a preparation method and application thereof. The ceramic silicon rubber compound comprises an adhesion layer, a heat insulation layer and a flame retardant layer in sequence. The tensile strength of the ceramic silicon rubber compound at room temperature is more than 3.8MPa, the elongation at break is more than 258%, and the Shore hardness is more than 69; the ceramic silicone rubber is obtained after the multi-layer structure silicone rubber is ceramic, and the bending strength is more than 12.7Mpa. The mechanical property, the thermal stability and the ceramic forming property of the ceramic-forming silicon rubber compound are greatly improved before ceramic forming, and the ceramic-forming silicon rubber compound has higher comprehensive performance. According to the invention, the ceramic forming performance and the mechanical performance of the silicone rubber are coordinated, so that the comprehensive performance matching of the material before and after the ceramization of the silicone rubber is realized, and the multi-level requirement of the service environment is met.

Description

Ceramic silicon rubber compound, ceramic silicon rubber and preparation method and application thereof

Technical Field

The invention belongs to the field of thermal protection silicone rubber materials, and particularly relates to a ceramic silicone rubber compound, ceramic silicone rubber, and a preparation method and application thereof.

Background

The ceramic polymer has excellent high temperature resistance, ablation resistance, flame retardance and other characteristics, and becomes a hot spot for developing heat protection materials in the fields of aerospace, ships, electronics and the like, wherein the organic silicon rubber taking a silicon-oxygen structure as a main chain becomes one of ideal matrixes of the ceramic polymer due to the excellent high and low temperature resistance, chemical stability, weather resistance, high residual weight and other characteristics. However, the product of the organic silicon rubber matrix after high-temperature ceramization is mainly amorphous silicon dioxide powder, so that a large amount of fluxing agent is required to be added to ensure that the organic silicon rubber matrix forms a ceramic block with a certain shape, thereby playing a role in high-temperature resistance, ablation resistance and flame retardance. The added large amount of fluxing agent is mainly ceramic filler such as glass powder and hydroxide powder with low melting point. For example, chinese patent document CN105884267a discloses that ceramic filler such as glass powder and hydroxide powder is introduced into organic silicone rubber to prepare ceramic organic silicone rubber with good ceramic performance, but the addition amount of fluxing agent is up to 120 parts by weight, and 90 parts by weight of glass powder is added, and the introduction of a large amount of glass powder can obtain ceramic product, but the mechanical performance of silicone rubber is seriously damaged, the tensile strength in normal temperature rubber state is >3Mpa, the mechanical performance and molding process performance of silicone rubber when used as rubber state are seriously affected, and the specific gravity of silicone rubber is increased, so that ceramic silicone rubber material with ideal comprehensive performance is often not obtained. In the existing silicon rubber ceramifiable technology, a large amount of low-melting-point glass powder is singly introduced to form a single-layer silicon rubber protective layer, the low-melting-point glass powder is melted into a liquid phase when ceramifiable silicon rubber is subjected to flame ablation to connect all added inorganic fillers, the mass transfer process and the crystal forming process at high temperature are promoted, the effect of reducing the ceramifing temperature is achieved, holes left when the silicon rubber ablates volatile gas can be made up in a flowing mode, if the adding amount is insufficient, the mechanical strength of a protective material after ceramifing is poor, but the introduction of a large amount of low-melting-point glass powder often leads to the deterioration of the mechanical property of the silicon rubber before ceramifing, and the contradictory mechanical property requirement brings harsh requirements to the use amount of the low-melting-point glass powder: the protective material with high ceramic property is prepared by using as little low-melting glass powder as possible. In a service environment, the thermal field to which the ceramifiable silicone rubber is subjected is not uniformly distributed, but a gradient field with gradually reduced temperature from outside to inside exists, and meanwhile, the outermost part is often subjected to a force-thermal coupling field at the same time, and the inside part is subjected to a single thermal field. The protective layer of single-layer silicone rubber currently used often does not effectively accommodate this protective requirement from force-thermal coupling to a single thermal field.

Disclosure of Invention

The invention overcomes the defects of the prior art, provides a ceramic silicon rubber compound, ceramic silicon rubber, a preparation method and application thereof, and realizes the comprehensive performance matching of the silicon rubber before and after ceramic by coordinating the ceramic forming performance and mechanical performance of the silicon rubber, thereby adapting to the multi-level requirements of the service environment.

The invention provides a ceramic silicon rubber compound, which at least has a three-layer structure: an adhesive layer, a heat insulating layer and a flame retardant layer; the adhesion layer, the heat insulation layer and the flame retardant layer all contain silicone rubber components;

the heat insulation layer also comprises a reinforcing filler, a porcelain-forming filler and a lightweight filler, and the adhesion layer also comprises a reinforcing filler, low-melting-point glass powder and a porcelain-forming filler.

According to an embodiment of the invention, the adhesion layer is in contact with the substrate, the heat insulating layer is arranged between the adhesion layer and the flame retardant layer, and the flame retardant layer is the outermost layer.

According to an embodiment of the invention, the layers of the silicone rubber are bonded by high temperature vulcanization.

According to an embodiment of the invention, the thickness ratio of the adhesion layer, the heat insulating layer and the flame retardant layer is 1 (0.5-2): (1-3), preferably 1:1:2.

According to an embodiment of the present invention, the raw materials of the flame retardant layer include: raw silicone rubber, a structure control agent, a reinforcing filler, a flame retardant, a porcelain-forming filler, a low-melting-point inorganic substance, reinforcing fibers and a vulcanizing agent; wherein the raw silicone rubber is at least one selected from methyl vinyl silicone rubber and methyl silicone rubber.

According to the embodiment of the invention, the raw materials of the flame-retardant layer comprise, by weight, 80-120 parts of raw silicone rubber, 1-8 parts of a structure control agent, 15-60 parts of a reinforcing filler, 20-80 parts of a flame retardant, 15-60 parts of a porcelain-forming filler, 10-40 parts of a low-melting-point inorganic substance, 0.5-40 parts of reinforcing fibers and 0.5-2 parts of a vulcanizing agent.

According to an embodiment of the present invention, the raw materials of the heat insulating layer include: raw silicone rubber, a structure control agent, a reinforcing filler, a porcelain forming filler, a lightweight filler and a vulcanizing agent; wherein the raw silicone rubber is at least one selected from methyl vinyl silicone rubber and methyl silicone rubber.

According to the embodiment of the invention, the raw materials of the heat insulation layer comprise 80-120 parts by weight of raw silicone rubber, 1-8 parts by weight of structure control agent, 15-60 parts by weight of reinforcing filler, 15-60 parts by weight of porcelain forming filler, 5-45 parts by weight of lightweight filler and 0.5-2 parts by weight of vulcanizing agent.

According to an embodiment of the present invention, the raw materials of the adhesion layer include: raw silicone rubber, a structure control agent, a reinforcing filler, a porcelain forming filler, a low-melting-point inorganic substance, a reinforcing fiber and a vulcanizing agent; wherein the silicone rubber is selected from methyl phenyl vinyl silicone rubber raw rubber.

The adhesive layer comprises, by weight, 80-120 parts of raw silicone rubber, 1-8 parts of a structure control agent, 15-60 parts of a reinforcing filler, 15-60 parts of a porcelain-forming filler, 10-40 parts of a low-melting-point inorganic substance, 2-40 parts of reinforcing fibers and 0.5-2 parts of a vulcanizing agent.

According to an embodiment of the present invention, the number average molecular weight of the methyl vinyl silicone rubber is 60 to 80 ten thousand, and the content of methyl vinyl silicone units is 0.05 to 0.5mol%. Preferably, the methyl vinyl silicone rubber is (high temperature) vulcanized silicone rubber with the number average molecular weight of 60-80 ten thousand composed of methyl vinyl silicone units and dimethyl silicone units, wherein the content of the methyl vinyl silicone units is 0.05-0.5 mol%.

According to an embodiment of the present invention, the number average molecular weight of the methyl phenyl silicone rubber is 60 to 80 ten thousand, the content of the phenyl-containing siloxane units is 10 to 20mol%, and the content of the methyl vinyl siloxane units is 0.05 to 0.5mol%. Preferably, the methyl phenyl silicone rubber is (high temperature) vulcanized silicone rubber with the number average molecular weight of 60-80 ten thousand, which is composed of methyl phenyl vinyl silicone chain units or diphenyl silicone chain units, methyl vinyl silicone chain units and dimethyl silicone chain units, wherein the content of the phenyl-containing silicone chain units is 10-20 mol percent, and the content of the methyl vinyl silicone chain units is 0.05-0.5 mol percent.

According to an embodiment of the present invention, the structure controlling agent is selected from at least one of hydroxy silicone oil, hexamethyldisilazane, diphenyl dihydroxy silane.

According to an embodiment of the present invention, the reinforcing filler is preferably white carbon black. Preferably, the white carbon black may be prepared by a method commonly used in the art, such as a precipitation method or a gas phase method. Preferably, the reinforcing filler may participate in the silicone rubber ceramming process.

According to an embodiment of the present invention, the flame retardant is at least one of magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, expandable graphite, zinc borate.

According to an embodiment of the present invention, the porcelain-forming filler is selected from at least one of clay mineral powders such as kaolin, wollastonite, mica powder, bentonite, talc, montmorillonite, and the like. Preferably, the porcelain-forming filler is selected from wollastonite; for example, needle wollastonite. Further, the ceramic-forming filler is preferably micron-sized powder.

According to an embodiment of the invention, the lightweight filler is selected from glass microspheres, phenolic microspheres having a hollow structure. The lightweight filler can play a role in heat insulation and light weight in the ceramifiable silicone rubber.

According to an embodiment of the present invention, the low-melting inorganic substance is selected from at least one of low-melting glass frit, boron oxide, lithium carbonate, and the like.

According to an embodiment of the invention, the reinforcing fibers are selected from at least one of glass fibers, carbon fibers, basalt fibers, ceramic fibers (preferably alumina fibers), quartz fibers, aramid fibers or polybenzoxazole fibers. Preferably, the reinforcing fibers have a diameter of no more than 20 microns and an aspect ratio of greater than 2:1 (e.g., 2:1, 3:1, 4:1, 5:1).

According to an embodiment of the invention, the vulcanizing agent is selected from compounds containing a peroxide structure for initiating vulcanization molding of the raw silicone rubber, for example compounds containing a peroxide structure known to a person skilled in the art may be used as vulcanizing agents, for example bis-dipentaerythritol vulcanizing agent or bis-dipentaerythritol vulcanizing agent.

According to an embodiment of the present invention, at least one of the reinforcing filler, the porcelain-forming filler, the lightweight filler, and the reinforcing fiber is subjected to a coupling treatment. Further, the coupling treatment may be performed by treating at least one of the reinforcing filler, the porcelain filler, the lightweight filler, and the reinforcing fiber with a coupling treatment agent.

According to an embodiment of the invention, the coupling treatment agent is selected from silane coupling agents or low molecular weight polysiloxanes. Further, the silane coupling agent is not particularly limited, and may be at least one silane coupling agent known in the art, for example, the silane coupling agent is selected from methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, hexamethyldisilazane, hexamethylcyclotrisilazane, octamethyl cyclotetrasiloxane, octaphenyl cyclotetrasiloxane, decamethyl cyclopentasiloxane.

Preferably, the low molecular weight polysiloxane is a polysiloxane having a number average molecular weight of more than 0 and not more than 1000, for example, at least one selected from hydrogen-containing polysiloxanes, vinyl-containing polysiloxanes, hydroxyl-containing polysiloxanes.

According to the embodiment of the invention, the mass ratio of the coupling treatment agent to the reinforcing filler, the porcelain-forming filler, the lightweight filler and the reinforcing fiber which are required to be treated is (0.5-2) (25-120).

According to an embodiment of the present invention, the raw material for preparing the multilayered structure ceramifiable silicone rubber may further comprise polysiloxane, preferably vinyl silicone oil. Preferably, the vinyl silicone oil is applied between the structural layers.

According to embodiments of the present invention, the basis of the parts by weight of the raw materials in each structural layer is consistent, such as in "grams", "kilograms".

According to an embodiment of the invention, the ceramifiable silicone rubber compound has at least one of the following properties:

(a1) The tensile strength at room temperature is greater than 3.8MPa, preferably 3.8-7.0MPa;

(a2) Elongation at break greater than 258%, preferably 258% -400%;

(a3) The shore hardness is greater than 69, preferably from 69 to 80, and more preferably from 69 to 72.

Illustratively, the ceramifiable silicone rubber compound has a tensile strength of 6.48MPa, 5.97MPa, or 3.85MPa at room temperature.

Illustratively, the ceramifiable silicone rubber compound has an elongation at break of 258%, 276%, or 392%.

Illustratively, the ceramifiable silicone rubber compound has a shore hardness of 69 or 72.

According to an embodiment of the present invention, the ceramifiable silicone rubber composition comprises at least a three-layer structure: an adhesive layer, a heat insulating layer and a flame retardant layer; the adhesion layer, the heat insulation layer and the flame retardant layer are respectively prepared from the raw materials of the layers, and the ceramic silicon rubber compound is obtained after the layers are overlapped.

The invention also provides a preparation method of the ceramic silicone rubber compound, which comprises the following steps: preparing raw materials of each layer of ceramic silicon rubber, and respectively mixing to obtain corresponding rubber layers of each layer; and sequentially overlapping and vulcanizing the sizing material layers to obtain the ceramic silicone rubber compound.

According to an embodiment of the invention, the raw materials of the layers before mixing are also subjected to mechanical blending.

According to an embodiment of the invention, part of the starting materials is further subjected to a coupling treatment.

According to an embodiment of the invention, a polysiloxane may be applied between the glue layers prior to lamination. The polysiloxane has the options as described above.

According to a preferred embodiment of the invention, the preparation method comprises the following steps:

step S1, uniformly mixing raw materials of an adhesive layer to obtain an adhesive layer rubber layer, wherein the raw materials of the adhesive layer have the meanings as described above;

step S2, uniformly mixing the raw materials of the heat insulation layer to obtain a heat insulation layer adhesive layer, wherein the raw materials of the heat insulation layer have the meanings as described above;

step S3, uniformly mixing the raw materials of the flame-retardant layer to obtain a flame-retardant layer adhesive layer, wherein the raw materials of the flame-retardant layer have the meanings as described above;

And S4, sequentially overlapping the adhesive layer, the heat-insulating layer and the flame-retardant layer to obtain the ceramifiable silicone rubber compound through vulcanization.

According to an embodiment of the present invention, in step S1, at least one of the raw material of the adhesion layer, the raw material of the heat insulating layer, the reinforcing filler in the raw material of the flame retardant layer, the porcelain-forming filler, the lightweight filler, and the reinforcing fiber is subjected to coupling treatment using the coupling treatment agent. Preferably, the coupling treatment comprises: adding the filler powder or fiber into the coupling treatment agent solution, stirring, mixing and ultrasonic dispersing under a sealing condition, and removing the solvent to obtain the filler or fiber after coupling treatment.

Preferably, in the coupling treatment agent solution, the mass fraction of the coupling treatment agent is 0.0015wt% to 0.005wt%. The preparation method of the coupling treatment agent solution comprises the following steps: the coupling treatment agent is added into a solvent and stirred and mixed under a sealing condition. Preferably, the solvent is selected from absolute ethanol, water or a mixture of both. Preferably, the solvent is a mixture of absolute ethanol and water, for example, the volume ratio of absolute ethanol to water is 10:1.

Preferably, when the coupling treatment is performed, the fillers or fibers may be separately subjected to the coupling treatment, or the fillers or fibers may be mixed according to the above ratio and then subjected to the coupling treatment. Preferably, the time of the stirring and mixing or ultrasonic dispersion is not particularly limited in the present invention so as to achieve uniformity of the filler or fiber. For example, the stirring and mixing time is 1 to 3 hours, preferably 2 hours. For example, the time of ultrasonic dispersion is 0.5 to 2 hours, preferably 1 hour.

According to an embodiment of the invention, the mixing in steps S1 to S3 is carried out in a two-roll mill. Preferably, the parameters of the two-roll mill include: the rolling speed is 30-40 rpm, the roll gap is 0.5-2 mm, and the temperature is 25-35 ℃ (preferably 30 ℃).

Preferably, the mixing is continued after the addition of the raw materials of each layer is completed. Preferably, the mixing time is from 5 to 30 minutes, for example 10 minutes.

Preferably, the raw materials of each layer are sequentially mixed. Illustratively, the other raw material is mixed when the former raw material is uniformly mixed until all raw materials are added, for example, the raw materials are uniformly mixed until the color is uniform. Preferably, the specific order of addition of the raw materials of each layer is not particularly required, and for example, the order of addition can be methyl phenyl vinyl silicone rubber or methyl vinyl silicone rubber, a flame retardant, a structure control agent, a reinforcing filler, a porcelain-forming filler, a lightweight filler, a reinforcing fiber and a vulcanizing agent.

According to an embodiment of the invention, after the mixing is completed, each gum layer is placed in a sealed state for more than 24 hours, preferably 24 hours. According to an embodiment of the invention, in step S4, the lamination refers to lamination in a mold. Preferably, in step S4, a silicone layer may also be applied in the mould before lamination. Preferably, in step S4, a polysiloxane layer may be further applied between each glue layer before lamination, so as to improve the bonding force between the layers and increase the crosslinking density.

Preferably, in step S4, the step of laminating refers to sequentially placing the flame retardant layer adhesive layer, the heat insulating layer adhesive layer and the adhesive layer in a mold and then closing the mold. Illustratively, within the mold, the flame retardant layer size layer is disposed on a bottom layer, the insulating layer size layer is disposed on a middle layer, and the adhesive layer size layer is disposed on an upper layer. Illustratively, in the mold, the adhesive layer size layer is placed on the bottom layer, the insulating layer size layer is placed on the middle layer, and the flame retardant layer size layer is placed on the upper layer.

According to an embodiment of the invention, the vulcanization in step S4 is carried out on a vulcanizing machine, preferably a flat vulcanizing machine. Preferably, the vulcanization temperature is 170-180 ℃, the vulcanization pressure is 10-15 MPa, and the vulcanization temperature is 10-15 min.

According to an embodiment of the invention, the vulcanization further comprises a secondary vulcanization.

According to an embodiment of the invention, the secondary vulcanization refers to placing the vulcanized silicone rubber on a vulcanizing machine in a vacuum oven. Preferably, the temperature of the secondary vulcanization is 180-200 ℃. Preferably, the secondary vulcanization time is 2 to 3 hours.

According to an embodiment of the present invention, the ceramifiable silicone rubber compound obtained by the above-described preparation method has the properties as described above.

The invention also provides application of the ceramic silicon rubber compound in preparation of ceramic silicon rubber.

The invention also provides ceramic silicon rubber, which is obtained by calcining the ceramic silicon rubber compound.

For example, the conditions of the calcination include: calcining at 700-900 deg.C in oxygen atmosphere for 10-30min; for example, calcination at 800℃for 15min in an air atmosphere.

According to an embodiment of the invention, the ceramic silicone rubber has at least one of the following properties:

(b1) The bending strength is more than 12.7Mpa, preferably 12.7-20.0Mpa;

(b2) The mass retention rate is more than 42%, preferably 42% -65%.

Illustratively, the ceramic silicone rubber has a flexural strength of 19.667MPa, 14.212MPa or 12.764MPa.

Illustratively, the ceramic silicone rubber mass retention is 63%, 52%, or 42%.

The invention also provides a preparation method of the ceramic silicon rubber, which comprises the step of calcining the ceramic silicon rubber compound to obtain the ceramic silicon rubber.

The invention also provides an application of the ceramic silicon rubber compound or the ceramic silicon rubber in the field of heat protection materials.

The invention also provides a thermal protection material, which comprises the ceramic silicone rubber.

The invention also provides application of the thermal protection material in the fields of aerospace, ships, electronics and the like. The thermal protection material has the meaning as described above.

Preferably, the heat protection material is used for fire-resistant cables, fire-proof strips of doors and windows, and the like. Preferably, the fire resistant cable comprises a cable wire of an electrical device, such as a marine cable.

The invention has the beneficial effects that:

the invention provides a ceramic silicon rubber compound which sequentially comprises an adhesion layer, a heat insulation layer and a flame retardant layer; when the ceramic silicone rubber compound is used for heat protection, the flame retardant layer is positioned on the outermost layer, and the ceramic silicone rubber compound has excellent flame retardant performance and wear resistance by adding enough flame retardant and a small amount of reinforcing fibers, and can directly contact flame during heat protection, so that oxygen ablation occurs; the heat insulation layer is used as an intermediate layer, and the heat insulation filler is added to form a middle heat insulation layer to prevent external heat from being transmitted inwards, so that the function of protecting the internal adhesion layer is achieved; the adhesion layer is located at the innermost layer, contacts the inner substrate to be protected, and is subject to ablation under anaerobic conditions during thermal protection while maintaining adequate toughness and adhesion at elevated temperatures. Through a multilayer design, the ceramic silicone rubber compound provided by the invention can greatly reduce the addition amount of lightweight fillers such as glass powder and the like, so that the mechanical property and the thermal stability of the silicone rubber before ceramic forming are improved. In addition, the thermal oxidative degradation of the inner adhesive layer can be effectively reduced in the practical application process of the outer flame-retardant layer, and the heat transfer of the middle heat-insulating filler can be effectively reduced, so that the time for maintaining the characteristics of the silicone rubber elastomer can be prolonged by the inner adhesive layer.

According to the invention, the filler is subjected to coupling treatment by using the coupling treatment agent, and the silane coupling agent can be subjected to condensation reaction with hydroxyl groups on the surface of the filler or form hydrogen bonds, so that the fillers are more tightly combined, and can be sintered into porcelain more easily when a fire disaster occurs, and meanwhile, the dispersibility of the filler in the ceramifiable silicone rubber compound is improved, and the mechanical property of the ceramifiable silicone rubber compound before the ceramifiation occurs is improved: the tensile strength at room temperature is more than 3.8MPa, the elongation at break is more than 258 percent, and the Shore hardness is more than 69.

According to the ceramic-made silicon rubber composite, a proper amount of hollow glass microspheres or hollow fibers are introduced into a ceramic-made silicon rubber composite system as a lightweight filler, so that the density of a composite material can be effectively reduced, partial melting can be realized at high temperature to form a small amount of liquid phase, a ceramic skeleton is reinforced, the bending strength of the ceramic-made silicon rubber composite after ceramic-making is improved, on the other hand, the molten liquid phase can accelerate the mass transfer process of the lightweight filler during sintering, promote the growth of crystal grains, reduce holes formed after the silicon rubber is ablated, so that a ceramic layer after ceramic-making is more compact, and the mechanical strength of the ceramic-made silicon rubber after ceramic-making is also improved.

The mechanical property, the thermal stability and the ceramic forming property of the ceramic-forming silicon rubber compound are greatly improved before ceramic forming, and the ceramic-forming silicon rubber compound has higher comprehensive performance. The ceramic silicon rubber prepared by the method has good application prospect in the field of heat protection.

Drawings

FIG. 1a is a photograph of the surface of the ceramic silicone rubber prepared in example 1 after the porcelain property test.

FIG. 1b is a photograph of a cross section of the ceramifiable silicone rubber composition prepared in example 1 prior to ceramifiability testing.

FIG. 2 is a field emission scanning electron microscope (FE-SEM) of the surface of the ceramized silicone rubber after ceramization performance test prepared in example 1.

FIG. 3 is a field emission scanning electron microscope (FE-SEM) of the flame retardant layer of a ceramized silicone rubber after ceramization performance test prepared in example 2.

FIG. 4 is a field emission scanning electron microscope (FE-SEM) of the thermal barrier layer of the ceramifiable silicone rubber composition prepared in example 2.

Detailed Description

The technical scheme of the invention will be further described in detail below with reference to specific embodiments. It is to be understood that the following examples are illustrative only and are not to be construed as limiting the scope of the invention. All techniques implemented based on the above description of the invention are intended to be included within the scope of the invention.

Unless otherwise indicated, the starting materials and reagents used in the following examples were either commercially available or may be prepared by known methods.

The components of the formulations referred to in the examples below were all in parts by weight. The silane coupling agent used in the following examples was KH-550. The methyl phenyl silicone rubber raw rubber and the methyl vinyl silicone rubber raw rubber refer to methyl phenyl silicone rubber and methyl vinyl silicone rubber which are not vulcanized, such as methyl vinyl silicone rubber which is purchased from Jiangxi star fire organic silicon and is sold under the brand name STARSIL GUM 753.

Example 1

The raw material formulation components of each layer of the ceramifiable silicone rubber compound in the embodiment are shown in table 1, and the specific preparation method is as follows: table 1 example 1 formulation composition table for each layer

Step 1, adding 50g of absolute ethyl alcohol and 5g of deionized water into a clean beaker, adding 0.1g of silane coupling agent into the beaker, stirring and mixing for 0.5h at room temperature of 20+/-5 ℃ under a sealing condition, then adding 2.0g of low-melting glass powder, 2.0g of mica powder and 0.5 of nylon fiber, continuously stirring and mixing for 2h at 20+/-5 ℃ under the sealing condition, dispersing for 1h under an ultrasonic environment, steaming in a water bath at 70 ℃ until no obvious liquid exists, then vacuum drying for 12h at 80 ℃ to obtain a coupling modified inner layer adhesive layer component, and weighing 4.59g; adding 50g of absolute ethyl alcohol and 5g of deionized water into a clean beaker according to the same method and weight ratio, adding 0.13g of silane coupling agent, stirring and mixing for 0.5h at room temperature of 20+/-5 ℃ under a sealing condition, then adding 3.0g of hollow fiber and 2.0g of mica powder, continuously stirring and mixing for 2h at 20+/-5 ℃ under the sealing condition, dispersing for 1h in an ultrasonic environment, steaming in a water bath at 70 ℃ until no obvious liquid exists, then drying for 12h at 80 ℃ in vacuum to obtain a middle-layer heat-insulating layer component after coupling modification, and weighing to be 5.12g; 50g of absolute ethyl alcohol and 5g of deionized water are added into a clean beaker according to the same method and weight proportion, 0.1g of silane coupling agent is added into the beaker, stirring and mixing are carried out for 0.5h at the room temperature of 20+/-5 ℃ under a sealing condition, then 2.0g of low-melting glass powder, 2.0g of mica powder and 0.5g of glass fiber are added, stirring and mixing are continued for 2h at the temperature of 20+/-5 ℃ under the sealing condition, the mixture is placed into an ultrasonic environment for dispersion for 1h, the mixture is distilled in a water bath at the temperature of 70 ℃ until no obvious liquid exists, then the mixture is placed into a vacuum drying mode at the temperature of 80 ℃ for 12h, and the coupled and modified outer flame-retardant layer component is obtained, and is weighed to be 4.59g.

Step 2, adding 10g of raw methyl phenyl silicone rubber, 0.6g of hydroxyl silicone oil and 2.0g of white carbon black into 4.59g of inner adhesive layer components after coupling modification in the previous step, sequentially adding 0.2g of double-twin-five vulcanizing agent into a double-roll open mill for mixing, mixing one material until the color of a wrapping roll is uniform, mixing the next material, adding the vulcanizing agent finally, setting the rolling speed of the double-roll open mill to be 30rpm, setting the roll gap to be 1mm, and keeping the temperature constant at 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing materials of the adhesive layer.

Step 3, adding 10g of raw methyl vinyl silicone rubber, 0.6g of hydroxyl silicone oil and 2.0g of white carbon black into 5.12g of middle layer heat insulation layer components after coupling modification in the previous step, sequentially adding 0.2g of double-double five vulcanizing agent into a double-roll open mill for mixing, mixing one material until the color of a wrapping roll is uniform, mixing the next material, adding the vulcanizing agent finally, setting the rolling speed of the double-roll open mill to be 30rpm, setting the roll gap to be 1mm, and keeping the temperature constant at 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing material of the heat insulation layer.

Step 4, adding 10g of methyl vinyl silicone rubber raw rubber, 0.6g of hydroxyl silicone oil, 4.0g of aluminum hydroxide and 2.0g of white carbon black into 4.59g of outer flame retardant layer components after coupling modification, sequentially adding 0.2g of double-twin-five vulcanizing agent into a double-roller open mill for mixing, mixing the materials until the color of a wrapping roller is uniform, mixing the materials into the next material, adding the vulcanizing agent finally, setting the rolling speed of the double-roller open mill to be 30rpm, setting the roll gap to be 1mm, and keeping the temperature constant at 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing material with the flame-retardant layer.

Step 5, coating a layer of vinyl silicone oil on the bottom layer of the clean die, carrying out remilling on the flame-retardant layer sizing material obtained in the step 4 for 5min, placing the mold bottom layer, coating a layer of vinyl silicone oil again, placing the heat-insulating layer sizing material obtained in the step 3 in the middle layer for 5min, coating a layer of vinyl silicone oil again, and placing the flame-retardant layer sizing material obtained in the step 2 in the upper layer for 5 min; and (3) placing the die into a flat vulcanizing machine, setting the temperature to be 170-180 ℃ and the pressure to be 10-15MPa, starting die assembly, and keeping for 10-15min after the temperature rises to the set temperature to obtain the primary vulcanized silicone rubber. And (3) placing the primary vulcanized silicone rubber in a vacuum oven at 180-200 ℃ for 2-3 hours, and finishing secondary vulcanization to obtain the ceramic silicone rubber compound with the multilayer structure.

The multi-layer ceramic silicone rubber compound of this example was subjected to physical and mechanical properties test according to national standard GB/T528-2009, and the test results are shown in table 2.

TABLE 2 mechanical Property test of the ceramifiable Silicone rubber Compound example 1

Test item	Tensile stress (Mpa)	Shore hardness of	Elongation at break (%)
				Test data	3.85	72	276

The ceramifiable silicone rubber compound prepared in example 1 was tested for ceramifiability. The specific test method is as follows:

cutting the prepared ceramic silicon rubber compound into rectangular bars with the diameter of 80 x 20 x 3mm, placing the rectangular bars in an alumina porcelain boat with the diameter of 80 x 20 x 3mm, calcining the rectangular bars in a muffle furnace at 800 ℃ for 15min, and obtaining a ceramic silicon rubber product in an air atmosphere.

FIG. 1a is a photograph of the surface of the ceramifiable silicone rubber compound prepared in example 1 after ceramifiability testing; fig. 1b is a photograph of a cross section of the ceramic silicone rubber compound prepared in example 1 before the ceramic performance test, wherein the three-layer structure is respectively assisted by a trace of dye filler to distinguish, and the adhesive layer, the heat-insulating layer and the flame-retardant layer are respectively arranged from top to bottom in fig. 1b, and the thickness ratio of each layer is 1:1:2. As can be seen from fig. 1a and 1b, the surface of the ceramic product is relatively flat and compact. The ceramic silicon rubber after being ablated at 800 ℃ is subjected to bending resistance test, and the obtained ceramic silicon rubber has the bending strength of 12.764Mpa and the mass retention rate of 42.3% before and after ablation. Fig. 2 is a Field Emission Scanning Electron Microscope (FESEM) diagram of the surface of the ceramic-enabled silicone rubber compound prepared in this example after the ceramic-enabled performance test, it can be seen that the surface of the ceramic-enabled product has fine holes and cracks, because the silicone rubber in the ceramic-enabled silicone rubber compound is ablated to form volatile gas under high temperature ablation, and fine holes and small amount of cracks are formed in the product and on the surface, at this time, the low-melting-point glass powder serving as a lightweight filler is softened at 300-500 ℃ and is completely melted into a liquid phase at 600-700 ℃, so that the holes and cracks left in the product after the silicon rubber is ablated are reduced, the ceramic layer of the ceramic-enabled product is more compact, and the mechanical strength of the ceramic-enabled product is improved.

Example 2

The raw material formulation components of each layer of the ceramic silicone rubber compound with the multilayer structure of the embodiment are shown in table 3, and the specific preparation method is as follows:

TABLE 3 example 2 formulation composition table for each layer

Step 1, adding 50g of absolute ethyl alcohol and 5g of deionized water into a clean beaker, adding 0.15g of silane coupling agent into the beaker, stirring and mixing for 0.5h at room temperature of 20+/-5 ℃ under a sealing condition, then adding 1.5g of low-melting-point glass powder, 4.0g of kaolin and 1.0g of aramid fiber, continuously stirring and mixing for 2h at 20+/-5 ℃ under the sealing condition, dispersing for 1h under an ultrasonic environment, steaming in a water bath at 70 ℃ until no obvious liquid exists, then vacuum drying for 12h at 80 ℃ to obtain a coupling modified inner layer adhesive layer component, and weighing 6.64g; adding 50g of absolute ethyl alcohol and 5g of deionized water into a clean beaker according to the same method and weight proportion, adding 0.15g of silane coupling agent, stirring and mixing for 0.5h at room temperature of 20+/-5 ℃ under a sealing condition, then adding 2.0g of hollow glass microspheres and 4.0g of kaolin, continuously stirring and mixing for 2h at 20+/-5 ℃ under the sealing condition, dispersing for 1h in an ultrasonic environment, steaming in a water bath at 70 ℃ until no obvious liquid exists, then drying in vacuum at 80 ℃ for 12h to obtain a middle-layer heat-insulating layer component after coupling modification, and weighing to be 6.14g; 50g of absolute ethyl alcohol and 5g of deionized water are added into a clean beaker according to the same method and weight proportion, 0.15g of silane coupling agent is added into the beaker, stirring and mixing are carried out for 0.5h at room temperature of 20+/-5 ℃ under a sealing condition, then 1.5g of low-melting glass powder, 4.0g of kaolin and 1.0g of glass fiber are added, stirring and mixing are continued for 2h at 20+/-5 ℃ under the sealing condition, the mixture is placed into an ultrasonic environment for dispersion for 1h, spin steaming is carried out until no obvious liquid exists under a water bath at 70 ℃, then the mixture is placed into a vacuum drying condition at 80 ℃ for 12h, and the coupled and modified outer flame-retardant layer component is obtained, and is weighed to be 6.64g.

Step 2, adding 10g of raw methyl phenyl silicone rubber, 0.4g of hydroxyl silicone oil and 3.0g of white carbon black, wherein the total amount of the components of the inner adhesive layer subjected to the coupling treatment in the previous step is 6.64g, 0.2g of a double-twin-five vulcanizing agent is sequentially added into a double-roll open mill for mixing, and when one material is mixed until the color of a wrapping roll is uniform, the next material is mixed, the vulcanizing agent is finally added, the rolling speed of the double-roll open mill is set to be 30rpm, the roll gap is set to be 1mm, and the temperature is constant to be 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing materials of the adhesive layer.

Step 3, adding 10g of raw methyl vinyl silicone rubber, 0.4g of hydroxyl silicone oil and 3.0g of white carbon black into 6.14g of middle-layer heat-insulating layer components subjected to coupling treatment in the previous step, sequentially adding 0.2g of double-double five vulcanizing agents into a double-roll open mill for mixing, mixing one material until the color of a wrapping roll is uniform, mixing the next material, adding the vulcanizing agents finally, setting the rolling speed of the double-roll open mill to be 30rpm, setting the roll gap to be 1mm, and keeping the temperature constant at 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing material of the heat insulation layer.

Step 4, adding 10g of raw methyl vinyl silicone rubber, 0.4g of hydroxyl silicone oil, 4.0g of magnesium hydroxide and 3.0g of white carbon black into 6.64g of the outer flame retardant layer components subjected to the coupling treatment in the previous step, sequentially adding 0.2g of double-twin-five vulcanizing agent into a double-roller open mill for mixing, mixing the materials until the color of a wrapping roller is uniform, mixing the materials into the next material, adding the vulcanizing agent finally, setting the rolling speed of the double-roller open mill to be 30rpm, setting the roll gap to be 1mm, and keeping the temperature constant at 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing material with the flame-retardant layer.

Step 5, coating a layer of vinyl silicone oil on the bottom layer of a clean die, carrying out remilling on the flame-retardant layer sizing material obtained in the step 4 for 5min, placing the mold bottom layer, coating a layer of vinyl silicone oil again, carrying out remilling on the thermal insulation layer sizing material obtained in the step 3 for 5min, placing the middle layer, coating a layer of vinyl silicone oil again, and placing the adhesion layer sizing material obtained in the step 2 on the upper layer after remilling for 5 min; and (3) placing the die into a flat vulcanizing machine, setting the temperature to be 170-180 ℃ and the pressure to be 10-15Mpa, starting die assembly, and keeping for 10-15min after the temperature rises to the set temperature to obtain the primary vulcanized silicone rubber. And (3) placing the primary vulcanized silicone rubber in a vacuum oven at 180-200 ℃ for 2-3 hours, and finishing secondary vulcanization to obtain the ceramic silicone rubber compound with the multilayer structure.

The multi-layer ceramic silicone rubber compound of this example was subjected to physical and mechanical properties test according to national standard GB/T528-2009, and the test results are shown in table 4.

TABLE 4 example 2 mechanical Property test of Multi-layer Structure ceramifiable Silicone rubber Compound

Test item	Tensile stress (Mpa)	Shore hardness of	Elongation at break (%)
				Test data	6.48	69	392

The ceramifiable silicone rubber compound prepared in example 2 was tested for ceramifiability. The specific test method is as follows:

cutting the prepared ceramic silicon rubber compound into rectangular bars with the diameter of 80mm being 20mm being 3mm, placing the rectangular bars in an alumina porcelain boat with the diameter of 80mm being 20mm being 3mm, calcining the rectangular bars in a muffle furnace at 800 ℃ for 15min, and obtaining a ceramic product, namely ceramic silicon rubber.

The ceramic silicon rubber after being ablated for 15min at 800 ℃ is subjected to bending resistance test, so that the bending strength is 14.212MPa, and the mass retention rate before and after ablation is 53%.

Fig. 3 is a FESEM diagram of the ceramic silicone rubber compound prepared in this example after the ceramic performance test, and it can be seen that after ceramic, the glass fiber is partially melted at high temperature, so as to block further heat transfer, and the ceramic silicone rubber compound plays a role of a bridge in the ceramic process, and connects inorganic filler components such as reinforcing filler and ceramic filler. Fig. 4 is a FESEM view of the insulating layer of the ceramifiable silicone rubber compound prepared in this example, showing the dispersion of the hollow glass microspheres in the ceramifiable silicone rubber compound, and showing that the hollow structure of the hollow glass microspheres is well preserved and tightly combined with the silicone rubber matrix.

Example 3

The raw material formulation components of each layer of the ceramic silicone rubber compound with the multilayer structure of the embodiment are shown in table 5, and the specific preparation method is as follows:

TABLE 5 example 3 formulation composition table for each layer

Step 1, adding 50g of absolute ethyl alcohol and 5g of deionized water into a clean beaker, adding 0.25g of silane coupling agent into the beaker, stirring and mixing for 0.5h at the room temperature of 20+/-5 ℃ under a sealing condition, then adding 1.0g of low-melting-point glass powder, 6.0g of wollastonite and 3.0g of aramid fiber, continuously stirring and mixing for 2h at the temperature of 20+/-5 ℃ under the sealing condition, dispersing for 1h under an ultrasonic environment, steaming in a water bath at the temperature of 70 ℃ until no obvious liquid exists, then vacuum drying for 12h at the temperature of 80 ℃ to obtain a coupling modified inner layer adhesive layer component, and weighing 10.26g; adding 50g of absolute ethyl alcohol and 5g of deionized water into a clean beaker according to the same method and weight ratio, adding 0.25g of silane coupling agent, stirring and mixing for 0.5h at room temperature of 20+/-5 ℃ under a sealing condition, then adding 4.0g of hollow glass microspheres and 6.0g of wollastonite, continuously stirring and mixing for 2h at 20+/-5 ℃ under the sealing condition, dispersing for 1h in an ultrasonic environment, steaming in a water bath at 70 ℃ until no obvious liquid exists, then drying for 12h at 80 ℃ in vacuum to obtain a middle-layer heat-insulating layer component after coupling modification, and weighing to be 10.24g; 50g of absolute ethyl alcohol and 5g of deionized water are added into a clean beaker according to the same method and weight proportion, 0.25g of silane coupling agent is added into the beaker, stirring and mixing are carried out for 0.5h at the room temperature of 20+/-5 ℃ under a sealing condition, then 1.0g of low-melting glass powder, 6.0g of wollastonite and 3.0g of glass fiber are added, stirring and mixing are continued for 2h at the temperature of 20+/-5 ℃ under the sealing condition, the mixture is placed into an ultrasonic environment for dispersion for 1h, the mixture is distilled in a water bath at the temperature of 70 ℃ until no obvious liquid exists, then the mixture is placed into a vacuum drying mode at the temperature of 80 ℃ for 12h, and the coupled and modified outer flame-retardant layer component is obtained and is weighed to be 10.24g.

Step 2, 10g of raw methyl phenyl silicone rubber, 0.6g of hydroxyl silicone oil and 4.0g of white carbon black are sequentially added into 10.26g of the inner layer adhesive layer compound subjected to the coupling treatment in the previous step, and 0.2g of a double-twin-five vulcanizing agent is sequentially added into a double-roll open mill for mixing, and when one material is mixed until the color of a wrapping roll is uniform, the next material is mixed, the vulcanizing agent is finally added, the rolling speed of the double-roll open mill is set to 30rpm, the roll gap is set to 1mm, and the temperature is constant to 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing materials of the adhesive layer.

Step 3, 10g of raw methyl vinyl silicone rubber, 0.6g of hydroxyl silicone oil and 4.0g of white carbon black are sequentially added into 10.24g of middle heat insulation layer components subjected to coupling treatment in the previous step, and 0.2g of double-double five vulcanizing agent is sequentially added into a double-roll open mill for mixing, and when one material is mixed until the color of a wrapping roll is uniform, the next material is mixed, the vulcanizing agent is finally added, the rolling speed of the double-roll open mill is set to be 30rpm, the roll gap is set to be 1mm, and the temperature is constant to be 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing material of the heat insulation layer.

Step 4, adding 10g of methyl vinyl silicone rubber raw rubber, 0.6g of hydroxyl silicone oil, 3.0g of magnesium hydroxide and 4.0g of white carbon black into 10.24g of the flame retardant layer components subjected to the coupling treatment in the previous step, sequentially adding 0.2g of double-twin-five vulcanizing agent into a double-roller open mill for mixing, mixing the materials until the color of a wrapping roller is uniform, mixing the materials into the next material, adding the vulcanizing agent finally, setting the rolling speed of the double-roller open mill to be 30rpm, setting the roll gap to be 1mm, and keeping the temperature constant at 30 ℃; and after all the sizing materials are added, continuing mixing for 10min, adjusting the roll gap to 5mm, discharging the sheets, and sealing and standing for 24h to obtain the sizing material with the flame-retardant layer.

Step 5, coating a layer of vinyl silicone oil on the bottom layer of the clean die, carrying out remilling on the flame-retardant layer sizing material obtained in the step 4 for 5min, placing the mold bottom layer, coating a layer of vinyl silicone oil again, placing the heat-insulating layer sizing material obtained in the step 3 in the middle layer for 5min, coating a layer of vinyl silicone oil again, and placing the adhesive layer sizing material obtained in the step 2 in the upper layer for 5 min; and (3) placing the die into a flat vulcanizing machine, setting the temperature to be 170-180 ℃ and the pressure to be 10-15MPa, starting die assembly, and keeping for 10-15min after the temperature rises to the set temperature to obtain the primary vulcanized silicone rubber. And (3) placing the primary vulcanized silicone rubber in a vacuum oven at 180-200 ℃ for 2-3 hours to finish secondary vulcanization, thereby obtaining the ceramic silicone rubber compound with the multilayer structure.

The multi-layer structure ceramifiable silicone rubber compound according to the national standard GB/T528-2009 is subjected to physical and mechanical property test, and the test results are shown in Table 6.

TABLE 6 mechanical Property test of Multi-layer Structure ceramifiable Silicone rubber Compound of example 3

Test item	Tensile stress (Mpa)	Shore hardness of	Elongation at break (%)
				Test data	5.97	72	258

The ceramifiability of the multilayer ceramifiable silicone rubber compound prepared in example 3 was tested. The specific test method is as follows:

cutting the prepared multilayer ceramic silicon rubber compound into rectangular bars with the diameter of 80mm being 20mm being 3mm, placing the rectangular bars in an alumina porcelain boat with the diameter of 80mm being 20mm being 3mm, calcining the rectangular bars in a muffle furnace at 800 ℃ for 15min, and obtaining a ceramic product, namely ceramic silicon rubber.

The bending resistance test is carried out on the multi-layer ceramic silicon rubber after being ablated for 15min at 800 ℃ to obtain the ceramic silicon rubber with the bending strength of 19.667Mpa and the mass retention rate of 63.85 percent before and after ablation.

According to the embodiment and the test result of the invention, the invention can make each filler component fully play a role by reasonably designing the multi-layer structure, and a small amount of low-melting-point inorganic matters (such as low-melting-point glass powder) is added to obtain the composite material capable of realizing high ceramic property, and the composite material has good mechanical property as the silicon rubber and can stably play the fireproof and heat-insulating functions.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A ceramifiable silicone rubber compound, wherein the ceramifiable silicone rubber compound has at least a three-layer structure: an adhesive layer, a heat insulating layer and a flame retardant layer; the adhesion layer, the heat insulation layer and the flame retardant layer all contain silicone rubber components; wherein, the liquid crystal display device comprises a liquid crystal display device,

the flame retardant layer also contains a flame retardant and reinforcing fibers, the heat insulation layer also contains a reinforcing filler, a porcelain-forming filler and a lightweight filler, and the adhesion layer also contains a reinforcing filler, low-melting-point glass powder and a porcelain-forming filler;

the adhesion layer is in contact with the substrate, the heat insulation layer is arranged between the adhesion layer and the flame retardant layer, and the flame retardant layer is the outermost layer;

the layers of the ceramic silicon rubber compound are combined through high-temperature vulcanization;

the thickness ratio of the adhesion layer, the heat insulation layer and the flame retardant layer is 1 (0.5-2): 1-3;

the raw materials of the flame-retardant layer comprise: raw silicone rubber, a structure control agent, a reinforcing filler, a flame retardant, a porcelain-forming filler, a low-melting-point inorganic substance, reinforcing fibers and a vulcanizing agent; wherein the silicone rubber is selected from at least one of methyl vinyl silicone rubber raw rubber and methyl silicone rubber raw rubber;

The flame-retardant layer comprises, by weight, 80-120 parts of raw silicone rubber, 1-8 parts of a structure control agent, 15-60 parts of a reinforcing filler, 20-80 parts of a flame retardant, 15-60 parts of a porcelain-forming filler, 10-40 parts of a low-melting-point inorganic substance, 0.5-40 parts of reinforcing fibers and 0.5-2 parts of a vulcanizing agent;

the raw materials of the heat insulation layer comprise: raw silicone rubber, a structure control agent, a reinforcing filler, a porcelain forming filler, a lightweight filler and a vulcanizing agent; wherein the raw silicone rubber is at least one selected from methyl vinyl silicone rubber and methyl silicone rubber;

the heat insulation layer comprises, by weight, 80-120 parts of silicon rubber, 1-8 parts of a structure control agent, 15-60 parts of a reinforcing filler, 15-60 parts of a porcelain-forming filler, 5-45 parts of a lightweight filler and 0.5-2 parts of a vulcanizing agent;

the raw materials of the adhesion layer comprise: raw silicone rubber, a structure control agent, a reinforcing filler, a porcelain forming filler, low-melting glass powder, reinforcing fibers and a vulcanizing agent; wherein the silicone rubber is selected from methyl phenyl vinyl silicone rubber raw rubber;

the adhesive layer comprises, by weight, 80-120 parts of raw silicone rubber, 1-8 parts of a structure control agent, 15-60 parts of a reinforcing filler, 15-60 parts of a porcelain-forming filler, 10-40 parts of low-melting glass powder, 2-40 parts of reinforcing fibers and 0.5-2 parts of a vulcanizing agent;

At least one of the reinforcing filler, the porcelain-forming filler, the lightweight filler and the reinforcing fiber is subjected to coupling treatment.

2. The ceramifiable silicone rubber composition of claim 1, wherein the thickness ratio of the adhesion layer, the thermal barrier layer, and the flame retardant layer is 1:1:2.

3. The ceramifiable silicone rubber compound of claim 1, wherein the structure controlling agent is selected from at least one of a hydroxy silicone oil, hexamethyldisilazane, diphenyl dihydroxy silane;

the reinforcing filler is white carbon black;

the flame retardant is at least one of magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, expandable graphite and zinc borate;

the ceramic-forming filler is at least one selected from kaolin, wollastonite, mica powder, bentonite, talcum powder and montmorillonite clay mineral powder;

the lightweight filler is selected from glass microspheres and phenolic microspheres with hollow structures;

the low-melting-point inorganic matter is at least one of low-melting-point glass powder, boron oxide and lithium carbonate;

the reinforcing fiber is at least one selected from glass fiber, carbon fiber, basalt fiber, ceramic fiber, aramid fiber or polybenzoxazole fiber;

The vulcanizing agent is selected from compounds containing peroxidic structures;

the coupling treatment agent is selected from silane coupling agent or low molecular weight polysiloxane;

the mass ratio of the coupling treating agent to the reinforcing filler, the porcelain-forming filler, the lightweight filler and the reinforcing fiber which are required to be treated is (0.5-2) (25-120).

4. The ceramifiable silicone rubber composite of claim 1, wherein the vulcanizing agent is a bis-di-pentavulcanizing agent or a bis-di-tetra vulcanizing agent;

the reinforcing fiber is selected from alumina fiber and quartz fiber.

5. A ceramifiable silicone rubber compound according to any of claims 1-3 wherein said ceramifiable silicone rubber compound has at least one of the following properties:

a1, the tensile strength at room temperature is more than 3.8Mpa;

a2, elongation at break is greater than 258%;

a3, the Shore hardness is more than 69;

the ceramifiable silicone rubber compound comprises at least a three-layer structure: an adhesive layer, a heat insulating layer and a flame retardant layer.

6. The ceramifiable silicone rubber composition of claim 5, wherein the tensile strength at room temperature is from 3.8 to 7.0 Mpa;

the elongation at break is 258-400%;

the Shore hardness is 69-80.

7. A method of preparing a ceramifiable silicone rubber composition as in any of claims 1-6 comprising: preparing raw materials of each layer of ceramic silicon rubber, and respectively mixing to obtain rubber layers of each layer; sequentially overlapping and vulcanizing the sizing material layers to obtain a ceramifiable silicone rubber compound;

the raw materials of each layer before mixing are mechanically blended;

at least one of reinforcing filler, porcelain filler, lightweight filler and reinforcing fiber in the raw materials is subjected to coupling treatment;

before lamination, a polysiloxane is applied between the glue layers.

8. The preparation method according to claim 7, characterized in that it comprises in particular the following steps:

step S1, uniformly mixing the raw materials of the adhesive layer to obtain a sizing material layer of the adhesive layer;

step S2, uniformly mixing the raw materials of the heat insulation layer to obtain a heat insulation layer sizing material layer;

step S3, uniformly mixing the raw materials of the flame-retardant layer to obtain a sizing material layer of the flame-retardant layer;

9. The method according to claim 8, wherein in step S1, at least one of the raw materials of the adhesion layer, the heat insulating layer, the reinforcing filler in the raw materials of the flame retardant layer, the porcelain-forming filler, the lightweight filler, and the reinforcing fiber is subjected to coupling treatment with a coupling treatment agent;

in the coupling treatment agent solution, the mass fraction of the coupling treatment agent is 0.0015 to 0.005 percent;

in step S4, the lamination refers to lamination in a mold;

the vulcanization further comprises secondary vulcanization;

the ceramic silicone rubber compound obtained by the preparation method.

10. Use of a ceramifiable silicone rubber composition as in any of claims 1-6 in the preparation of a ceramifiable silicone rubber.

11. A ceramifiable silicone rubber, characterized in that it is obtained by calcining the ceramifiable silicone rubber compound according to any of claims 1 to 6.

12. The ceramified silicone rubber of claim 11, wherein the ceramified silicone rubber has at least one of the following properties:

b1, bending strength is more than 12.7Mpa;

b2, the mass retention rate is more than 42%.

13. The ceramified silicone rubber of claim 12, wherein the flexural strength is 12.7-20.0Mpa;

The mass retention rate is 42-65%.

14. The ceramifiable silicone rubber of claim 11, wherein the method of making the ceramifiable silicone rubber comprises calcining the ceramifiable silicone rubber composite to obtain the ceramifiable silicone rubber.

15. Use of a ceramifiable silicone rubber compound according to any of claims 1 to 6 or a ceramifiable silicone rubber according to any of claims 11 to 14 in the field of thermal protection materials.

16. A thermal protection material comprising the ceramifiable silicone rubber compound of any of claims 1-6 or the ceramifiable silicone rubber of any of claims 11-14.

17. Use of the thermal protection material of claim 16 in the fields of aerospace, marine, electronics.